Is it possible that in the distant future, an organism that exists right now on Earth, will evolve to the point that it can be considered intelligent life? Which animal comes the closest?

Answer:
 > Is it possible that in the distant future, an organism that exists right now on Earth, will evolve to the point that it can be considered intelligent life?

Yes, it's possible, but by no means is it a sure thing.  Evolution doesn't have a goal in mind, nor does it have specific end points that are inherently better than others.  Evolution adapts to the environment, and what works works, what doesn't dies off.
 > Which animal comes the closest?

We have a difficult time defining intelligence *within our own species*.  The difficulty goes up astronomically when you look at other species.

Are you talking about technic intelligence?  It's unlikely anything in the ocean will ever develop technology (at least, as far as we can tell - without fire lots of tools are going to be difficult to make).

Social intelligence?  Well, insects seem to have a big advantage there... but they're probably a ways off on the tool front.

etc, etc, etc.

You see the difficulties?

Answer:
Evolution is not directed.

We can't answer this without speculation.


How much can you learn from someone's genome?

I've heard you can learn id someone by looking at their DNA, but what else can you learn if you know what to look for?

Answer:
Well this is fun, we literally just covered this kind of stuff in my advanced molecular biology course.

Your genome will contain variation depending on genetics that has been passed down from your parents.  You may be homozygous for 11 copies of a short-tandem repeat (STR, 2-3 'letters' repeated over and over again in the sequence) where I will be heterozygous for 13 and 8 copies. Your "DNA fingerprint" that the FBI uses involves these regions, when the areas that contain them are amplified by PCR, they show up as different lengths.

Furthermore, there are single-nucleotide-polymorphisms (SNPs) where you may have an A where I have a C (or C-A or T-G or T-A...you get the point).  There are also "indels" - insersions or deletions relative to one genomre or another.  These can serve as markers for disease or other traits, especially if they occur in protein coding genes.  There are a very very large number of these variations, and I could predict (not even close to 100% certainty, though) some traits about you as well as heritable diseases you may carry.  The debate on nature/nurture is how certain could I be given your genotype?

[This database](_URL_0_) is called Online Mendellian Inheritance in Man and catalogs diseases/traits and contains a *wealth* of SNP and indel data about them.  Doing some mining, you can find tables like [these](_URL_1_) that will list all known variants for a gene and link to more information about them.  This example is the Von Willebrands Factor, mutations of which cause Von Willebrands Disease which is a mild bleeding disorder.  I don't know your background, but this site contains a lot of very technical information.

You may have heard of [23andMe](_URL_2_) which is a commercial service that will assay your genome for specific markers as well.

EDIT: If your family has submitted their genomes to a database as well, we could ID them as well


Context: Provided is a universal Ku band LNB (9.75/10.600 GHz) which is fitted at the end of the dish and pointed at the correct satellite constellation; most digital receivers will receive the free to air channels. Some broadcasts are free-to-air and unencrypted, some are encrypted but do not require a monthly subscription (known as free-to-view), some are encrypted and require a monthly subscription, and some are pay-per-view services. To view the encrypted content a VideoGuard UK equipped receiver (all of which are dedicated to the Sky service, and cannot be used to decrypt other services) needs to be used. Unofficial CAMs are now available to view the service, although use of them breaks the user's contract with Sky and invalidates the user's rights to use the card.

Question: What is the universal band that digital recievers will receive free to air channels on?

9.75/10.600 GHz
universal Ku band
Ku band


Context: At the beginning of the 20th century, important advancement in geological science was facilitated by the ability to obtain accurate absolute dates to geologic events using radioactive isotopes and other methods. This changed the understanding of geologic time. Previously, geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another. With isotopic dates it became possible to assign absolute ages to rock units, and these absolute dates could be applied to fossil sequences in which there was datable material, converting the old relative ages into new absolute ages.

Question: What did using fossils help change for scientists?


Context: Packet mode communication may be implemented with or without intermediate forwarding nodes (packet switches or routers). Packets are normally forwarded by intermediate network nodes asynchronously using first-in, first-out buffering, but may be forwarded according to some scheduling discipline for fair queuing, traffic shaping, or for differentiated or guaranteed quality of service, such as weighted fair queuing or leaky bucket. In case of a shared physical medium (such as radio or 10BASE5), the packets may be delivered according to a multiple access scheme.

Question: If there is no radio or 10BASE5, how are the packets delivered?


Context: Many complexity classes are defined using the concept of a reduction. A reduction is a transformation of one problem into another problem. It captures the informal notion of a problem being at least as difficult as another problem. For instance, if a problem X can be solved using an algorithm for Y, X is no more difficult than Y, and we say that X reduces to Y. There are many different types of reductions, based on the method of reduction, such as Cook reductions, Karp reductions and Levin reductions, and the bound on the complexity of reductions, such as polynomial-time reductions or log-space reductions.

Question: What are two examples of different types of reduction?

Karp reductions and Levin reductions
Cook reductions, Karp reductions


Context: In 1096, Crusaders passing by the siege of Amalfi were joined by Bohemond of Taranto and his nephew Tancred with an army of Italo-Normans. Bohemond was the de facto leader of the Crusade during its passage through Asia Minor. After the successful Siege of Antioch in 1097, Bohemond began carving out an independent principality around that city. Tancred was instrumental in the conquest of Jerusalem and he worked for the expansion of the Crusader kingdom in Transjordan and the region of Galilee.[citation needed]

Question: When did Tancred lay siege to Antioch?


Context: In October 2010, the open-access scientific journal PLoS Pathogens published a paper by a multinational team who undertook a new investigation into the role of Yersinia pestis in the Black Death following the disputed identification by Drancourt and Raoult in 1998. They assessed the presence of DNA/RNA with Polymerase Chain Reaction (PCR) techniques for Y. pestis from the tooth sockets in human skeletons from mass graves in northern, central and southern Europe that were associated archaeologically with the Black Death and subsequent resurgences. The authors concluded that this new research, together with prior analyses from the south of France and Germany, ". . . ends the debate about the etiology of the Black Death, and unambiguously demonstrates that Y. pestis was the causative agent of the epidemic plague that devastated Europe during the Middle Ages".

Question: What scientific journal in France published a prior analysis of the Black Death?


zeit zu schlafen


zeit schlafen zu gehen olly


Amanda: I baked  cookies. Do you want some?
Jerry: Sure!
Amanda: I'll bring you tomorrow :-)

Summary: A baked cookies and will bring B some tomorrow.

A: I baked  cookies. Do you want some?
B: Sure!
A: I'll bring you tomorrow :-)


Olivia: Who are you voting for in this election?
Oliver: Liberals as always.
Olivia: Me too!!
Oliver: Great

Summary: B and Olivier are voting for liberals in this election.

B: Who are you voting for in this election?


Tim: Hi, what's up?
Kim: Bad mood tbh, I was going to do lots of stuff but ended up procrastinating
Tim: What did you plan on doing?
Kim: Oh you know, uni stuff and unfucking my room
Kim: Maybe tomorrow I'll move my ass and do everything
Kim: We were going to defrost a fridge so instead of shopping I'll eat some defrosted veggies
Tim: For doing stuff I recommend Pomodoro technique where u use breaks for doing chores
Tim: It really helps
Kim: thanks, maybe I'll do that
Tim: I also like using post-its in kaban style

Summary: B may try the pomodoro technique recommended by A to get more stuff done.

B: Bad mood tbh, I was going to do lots of stuff but ended up procrastinating

B: Oh you know, uni stuff and unfucking my room

B: Maybe tomorrow I'll move my ass and do everything

B: We were going to defrost a fridge so instead of shopping I'll eat some defrosted veggies

A: For doing stuff I recommend Pomodoro technique where u use breaks for doing chores

A: I also like using post-its in kaban style


Edward: Rachel, I think I'm in ove with Bella..
rachel: Dont say anything else..
Edward: What do you mean??
rachel: Open your fu**ing door.. I'm outside

Summary: A thinks he is in love with Bella. Rachel wants A to open his door. Rachel is outside.

A: Rachel, I think I'm in ove with Bella..


Sam: hey  overheard rick say something
Sam: i don't know what to do :-/
Naomi: what did he say??
Sam: he was talking on the phone with someone
Sam: i don't know who
Sam: and he was telling them that he wasn't very happy here
Naomi: damn!!!
Sam: he was saying he doesn't like being my roommate
Naomi: wow, how do you feel about it?
Sam: i thought i was a good rommate
Sam: and that we have a nice place
Naomi: that's true man!!!
Naomi: i used to love living with you before i moved in with me boyfriend
Naomi: i don't know why he's saying that
Sam: what should i do???
Naomi: honestly if it's bothering you that much you should talk to him
Naomi: see what's going on
Sam: i don't want to get in any kind of confrontation though
Sam: maybe i'll just let it go
Sam: and see how it goes in the future
Naomi: it's your choice sam
Naomi: if i were you i would just talk to him and clear the air

Summary: B is confused, because he overheard Rick complaining about him as a roommate. A thinks B should talk to Rick. B is not sure what to do.

B: he was talking on the phone with someone

B: and he was telling them that he wasn't very happy here

B: he was saying he doesn't like being my roommate

A: i used to love living with you before i moved in with me boyfriend

A: honestly if it's bothering you that much you should talk to him

B: i don't want to get in any kind of confrontation though

A: if i were you i would just talk to him and clear the air


Neville: Hi there, does anyone remember what date I got married on?
Don: Are you serious?
Neville: Dead serious. We're on vacation, and Tina's mad at me about something. I have a strange suspicion that this might have something to do with our wedding anniversary, but I have nowhere to check.
Wyatt: Hang on, I'll ask my wife.
Don: Haha, someone's in a lot of trouble :D
Wyatt: September 17. I hope you remember the year ;)

Summary: A reminds C his wedding anniversary is on the 17th of September. C's wife is upset and it might be because C forgot about their anniversary.

C: Hi there, does anyone remember what date I got married on?

C: Dead serious. We're on vacation, and Tina's mad at me about something. I have a strange suspicion that this might have something to do with our wedding anniversary, but I have nowhere to check.

B: Haha, someone's in a lot of trouble :D

A: September 17. I hope you remember the year ;)


John: Ave. Was there any homework for tomorrow?
Cassandra: hello :D Of course, as always :D
John: What exactly?
Cassandra: I'm not sure so I'll check it for you in 20minutes.
John: Cool, thanks. Sorry I couldn't be there, but I was busy as fuck...my stupid boss as always was trying to piss me off
Cassandra: No problem, what did he do this time?
John: Nothing special, just the same as always, treating us like children, commanding to do this and that...
Cassandra: sorry to hear that. but why don't you just go to your chief and tell him everything?
John: I would, but I don't have any support from others, they are like goddamn pupets and pretend that everything's fine...I'm not gonna fix everything for everyone
Cassandra: I understand...Nevertheless, just try to ignore him. I know it might sound ridiculous as fuck, but sometimes there's nothing more you can do.
John: yeah I know...maybe some beer this week?
Cassandra: Sure, but I got some time after classes only...this week is gonna be busy
John: no problem, I can drive you home and we can go to some bar or whatever.
Cassandra: cool. ok, I got this homework. it's page 15 ex. 2 and 3, I also asked the others to study another chapter, especially the vocabulary from the very first pages. Just read it.
John: gosh...I don't know if I'm smart enough to do it :'D
Cassandra: you are, don't worry :P Just circle all the words you don't know and we'll continue on Monday.
John: ok...then I'll try my best :D
Cassandra: sure, if you will have any questions just either text or call me and I'll help you.
John: I hope I won't have to waste your time xD
Cassandra: you're not wasting my time, I'm your teacher, I'm here to help. This is what I get money for, also :P
John: just kidding :D ok, so i guess we'll stay in touch then
Cassandra: sure, have a nice evening :D
John: you too, se ya
Cassandra: Byeeeee

Summary: B didn't show up for class due to some work issues with his boss. A, his teacher told him which exercises to do, and which chapter to study. They are going to meet up for a beer sometime this week after class.

B: Ave. Was there any homework for tomorrow?

A: I'm not sure so I'll check it for you in 20minutes.

B: Cool, thanks. Sorry I couldn't be there, but I was busy as fuck...my stupid boss as always was trying to piss me off

A: No problem, what did he do this time?

B: Nothing special, just the same as always, treating us like children, commanding to do this and that...

A: sorry to hear that. but why don't you just go to your chief and tell him everything?

B: I would, but I don't have any support from others, they are like goddamn pupets and pretend that everything's fine...I'm not gonna fix everything for everyone

A: I understand...Nevertheless, just try to ignore him. I know it might sound ridiculous as fuck, but sometimes there's nothing more you can do.

B: yeah I know...maybe some beer this week?

A: Sure, but I got some time after classes only...this week is gonna be busy

B: no problem, I can drive you home and we can go to some bar or whatever.

A: cool. ok, I got this homework. it's page 15 ex. 2 and 3, I also asked the others to study another chapter, especially the vocabulary from the very first pages. Just read it.

B: gosh...I don't know if I'm smart enough to do it :'D

A: you are, don't worry :P Just circle all the words you don't know and we'll continue on Monday.

A: sure, if you will have any questions just either text or call me and I'll help you.

B: I hope I won't have to waste your time xD

A: you're not wasting my time, I'm your teacher, I'm here to help. This is what I get money for, also :P

B: just kidding :D ok, so i guess we'll stay in touch then


Sarah: I found a song on youtube and I think you'll like it
James: What song?
Sarah: <file_other>
James: Oh. I know it!
James: I heard it before in some compilation
Sarah: I can't stop playing it over and over
James: That's exactly how I know lyrics to all of the songs on my playlist :D
Sarah: Haha. No lyrics here though. Instrumental ;D
James: Instrumental songs are different kind of music.
James: But you have to remember that the activity you do when you listen to this song
James: Is the actvity your brain will connect to the song
James: And everytime you play this song at home
James: You'll be thinking of your work
Sarah: Yeah, I know that. That's why we sometimes say - I used to like that song, but now it just reminds me of bad memories
James: Yup. Everytime you change your partner, you have to get rid of your favorite music :D
Sarah: Hahaha. True, true.

Summary: A sends B an instrumental song he might like. B knows the song. The brain connects the songs to the context they were played in and brings to mind the associated memories.

A: I found a song on youtube and I think you'll like it

B: I heard it before in some compilation

A: I can't stop playing it over and over

B: That's exactly how I know lyrics to all of the songs on my playlist :D

A: Haha. No lyrics here though. Instrumental ;D

B: Instrumental songs are different kind of music.

B: But you have to remember that the activity you do when you listen to this song

B: Is the actvity your brain will connect to the song

B: And everytime you play this song at home

A: Yeah, I know that. That's why we sometimes say - I used to like that song, but now it just reminds me of bad memories

B: Yup. Everytime you change your partner, you have to get rid of your favorite music :D


Noah: When and where are we meeting? :)
Madison: I thought you were busy...?
Noah: Yeah, I WAS. I quit my job.
Madison: No way! :o :o :o Why? I thought you liked it...?
Noah: Well, I used to, until my boss turned into a complete cock... Long story.

Summary: B wants to meet, he quit his job, because his boss was a dick.

A: No way! :o :o :o Why? I thought you liked it...?

B: Well, I used to, until my boss turned into a complete cock... Long story.


Matt: Do you want to go for date?
Agnes: Wow! You caught me out with this question Matt.
Matt: Why?
Agnes: I simply didn't expect this from you.
Matt: Well, expect the unexpected.
Agnes: Can I think about it?
Matt: What is there to think about?
Agnes: Well, I don't really know you.
Matt: This is the perfect time to get to know eachother
Agnes: Well that's true.
Matt: So let's go to the Georgian restaurant in Kazimierz.
Agnes: Now your convincing me.
Matt: Cool, saturday at 6pm?
Agnes: That's fine.
Matt: I can pick you up on the way to the restaurant.
Agnes: That's really kind of you.
Matt: No problem.
Agnes: See you on saturday.
Matt: Yes, looking forward to it.
Agnes: Me too.

Summary: B invites A for a date to get to know each other better. They'll go to the Georgian restaurant in Kazimierz on Saturday at 6 pm, and he'll pick her up on the way to the place.

A: Wow! You caught me out with this question B.

A: I simply didn't expect this from you.

B: This is the perfect time to get to know eachother

B: So let's go to the Georgian restaurant in Kazimierz.

B: I can pick you up on the way to the restaurant.


This position requires you to work remotely from the office of our client.


This job allows people to mostly work at there own homes.


This position does not allow us to come to the office


the use of various imaging techniques in post - treatment assessment of head  neck cancer is gradually on the rise , though clinical examinations at periodic intervals still remains the mainstay of follow - up .
18f fdg pet / ct is increasingly used in the post - treatment setting to diagnose residual / recurrent disease early so that appropriate treatment can be initiated .
the effects of multimodality treatment such as surgery , radiation , and chemotherapy can distort normal anatomical landmarks induce inflammation and infection , which can mask disease .
it is important to understand the anatomical and functional effects as well as complications produced by these treatment modalities in order to diagnose the resultant imaging pitfalls on fdg pet / ct .
knowledge of the common and unusual patterns of loco - regional recurrent disease and distant metastases on fdg pet / ct is also crucial in the post - treatment assessment of head - neck cancer patients .
radiation therapy alone or in combination with chemotherapy is often used to treat head - neck cancer patients .
there are several tissue changes , which are a result of early reaction to radiation .
these include thickening of the skin and platysma , stranding of the subcutaneous fat , pharyngeal and laryngeal wall thickening and increased vascularity of the major and minor salivary glands .
edema , inflammation , and increased vascularity in these structures lead to a pattern of fdg uptake which is low grade , diffuse , symmetrical , and restricted to the radiation field [ figure 1 ] .
these findings are seen during the course or within 3 months of radiation therapy and are often reversible .
several muscle groups within the radiation field also demonstrate an elevated fdg activity which can be potentially confused with neoplastic uptake .
however , absence of a mass lesion on ct and reduction over time differentiate an inflammatory or physiological uptake from disease .
axial pet and fused pet / ct images show diffuse symmetrical fdg uptake in the tongue and oropharynx ( arrows in the b and c ) and in the floor of mouth ( arrows in e and f ) .
diffuse low intensity fdg uptake is also seen in the neck muscles ( arrowheads in b , c , e , f ) .
diffuse uptake is seen within a few days of radiation and can last up to 810 weeks timing of pet / ct after radiation therapy is an important and often debated clinical issue .
performing pet / ct as early as possible to detect recurrent disease seems logical as salvage treatment can be initiated early enough to derive the best possible clinical benefit .
however , studies performed too early may lead to false positive as well as false negative results .
possible mechanism for false negative studies has been attributed to radiation induced vascular damage , which temporarily prevents concentration of radiotracer in the viable tumor cells .
imaging after a further few weeks delay in such cases may allow accumulation of tracer in the viable cells leading to a true positive pet result .
waiting too long to image might result in a loss of therapeutic window and also a more complicated surgical procedure due to fibrosis setting in . in order to strike a balance between misleading pet results when study is performed early and the clinical drawbacks of imaging late , a time interval of 12 weeks after completion of radiation therapy is generally recommended .
absence of fdg uptake at both the primary and nodal sites has a high negative predictive value in ruling out residual disease [ figure 2 ] .
studies have shown that a negative pet scan can potentially defer planned neck dissections after chemo - radiation therapy .
pretreatment coronal fused pet / ct ct studies show fdg avid right sided hypopharyngeal mass ( arrow in a and b ) .
study performed 8 weeks after completion of chemo - radiation therapy show complete metabolic and morphologic response ( arrow in c and d ) which rules out the possibility of residual disease
curative resection involves complex surgical procedures , which result in loss of symmetry and anatomical landmarks .
various reconstructive techniques are used to close the surgical defects and restore function which produces characteristic well - recognizable imaging findings .
procedures such as glossectomy , marginal or segmental mandibulectomy , maxillectomy leave large surgical defects , which are closed by flaps and grafts . pectoralis
myocutaneous flap is an example of a composite flap which is often used for reconstruction of large surgical defects in the face , tongue , and skull base .
they can be recognized by the well marginated soft tissue / muscle density at the site of the defect and is often accompanied by fat density [ figure 3a , b ] produced by a denervation atrophy and fatty replacement of the muscle .
normal symmetric pattern of tracer concentration is disturbed due to absence of physiological fdg uptake at the resected and reconstructed site [ figure 3b and d ] . in patients undergoing total laryngo - pharyngectomy ,
a neopharynx is reconstructed which can be recognized as a simple tubular structure sans the accompanying complex anatomy of hypopharynx and larynx [ figure 4 ] .
the neopharynx is often constructed by using a jejunal free flap , which is recognised recognized by the mesenteric fat along with its native vessels .
axial fused pet / ct images show myocutaneous flap with fat density used to reconstruct the defect after hemimandibulectomy ( arrow in a ) and mandibular symphysectomy ( arrow in b ) performed for buccal cancer absence of normal physiological fdg uptake in the reconstructed flap ( arrowheads in a and b ) tissue changes after surgery .
axial ct shows a reconstructed neopharynx after a laryngopharyngectomy seen as a tubular structure ( arrow in a ) .
diffuse low grade physiological uptake is seen around the neopharynx ( arrow head in b )
during or after the course of treatment pitfalls in image interpretation can occur due to several factors .
asymmetric nature of physiological uptake , inflammations / infective processes , and treatment - related complications are some of the common causes of false positive results leading to imaging pitfalls .
sometimes , as a consequence of late effects of radiation therapy , there is a reduction of the normal physiological fdg uptake in structures such as the salivary glands and pharyngeal mucosal lining on the side of the therapy , leading to an appearance of asymmetric increased uptake in the normal tissues on the contralateral side [ figure 5 ] .
coronal and axial ( pet ) and fused pet / ct images show reduction in physiological uptake ( arrows in a , b , d ) on the left side due to long term effects of radiation therapy .
note the relative increase in physiological uptake in the parotid and submandibular glands and the oropharynx on the contralateral normal side which can mimic pathology ( arrowheads in a and d ) absence of physiological fdg uptake in the region of the surgically removed part and persistence of physiological uptake in the normal contralateral side produces an appearance of asymmetric tracer concentration that can mimic disease [ figure 6 ] .
occasionally , after partial resection of an organ such as the tongue , the remnant portion retains its physiological uptake , which appears focal in nature mimicking disease [ figure 7 ] .
after extensive jaw surgeries and reconstructive procedures , the altered mechanics of mastication can result in physiologically increased focal uptake in the adjacent masticator muscles that can be mistaken for disease [ figure 8 ] .
axial ct shows changes of right hemiglossectomy with a myocutaneous flap containing fat ( arrowhead in a ) .
axial pet and fusion pet / ct show physiological uptake in the remnant tongue which is focal and asymmetric in nature ( arrows in b and c ) and can potentially mimic disease pitfalls of due asymmetric physiological uptake .
coronal pet and fusion pet / ct show physiological uptake along the right side of the oral cavity and the floor of mouth which is asymmetric in nature ( arrows in b and c ) and can potentially mimic disease .
note the absence of normal physiological uptake on the left side ( arrowheads in b and c ) .
this pattern was seen more than a year after treatment pitfalls of due asymmetric physiological uptake .
axial pet and fusion pet / ct show focal asymmetric uptake in the left masseter which is physiological in nature ( arrows in a and b ) and is produced due to altered mechanics of mastication secondary to jaw surgery physiological uptake in the tongue tip and oral cavity arising due to close approximation of tongue and palate , buccal and gingival mucosae can be better resolved by performing certain maneuvers like puffing the cheek and placing a gauzegauze that can help mouth opening .
surgical complications occur early and include serous collections , infections , abscess and fistula formation , flap necrosis .
benign serous collections are self - limiting and should be distinguished from infected abscesses that might need a drainage procedure .
benign serous collections also called seromas usually do not show any fdg avidity unless they get infected . on fdg pet / ct abscesses
show a rim of tracer uptake in the periphery with a photopenic center which corresponds to a hypodense collection on ct with air pockets seen occasionally .
linear fdg uptake is seen along the fistulous communications associated with abscesses [ figure 9 ] .
these complications occur at the site of surgical resection and reconstructed flaps in the head  neck region .
rarely , one can come across infections / inflammations at the site of the donor flap in the chest or the abdominal wall and focal tracer uptake in this region can potentially mimic metastatic disease [ figure 10 ] .
axial fused pet / ct shows an intense focus of fdg uptake in the infratemporal fossa mimicking disease recurrence ( arrow in b ) .
corresponding contrast ct image shows a hypodense collection with an air pocket ( arrow in a ) suggestive of an abscess .
note the linear fdg uptake along the enhancing fistulous tract opening on the skin surface .
( arrowheads in a and b ) pitfalls due to treatment related complications ( surgery ) .
coronal mip image shows an intense focus of fdg uptake in the left hemithorax ( arrow in a ) which appears to be metastatic disease .
fused pet / ct shows focal uptake in the anterior chest wall ( arrow in c ) which was the site for the pmmc flap .
arrowhead in b ) radiation toxicity can lead to intense inflammatory changes in the mucosal structures and the soft tissues of the neck that can cause intense fdg accumulation [ figure 11 ] .
coronal pet ( b ) and fused pet / ct ( c ) shows intense fdg uptake in the naso , oro , and hypopharyngeal structures and the soft tissue of the neck bilaterally , with associated ill - defined fat stranding ( a  arrowhead ) .
such intense non - infective inflammation is seen on rare occasions after radiation and should not be confused with recurrence radiation induced necrosis can occur in bones ( osteoradionecrosis [ orn ] ) , cartilage ( chondronecrosis / laryngeal necrosis ) and even in irradiated soft tissues .
osteoradionecrosis ( orn ) occurs due to devitalization of irradiated bone which gets exposed through the skin and mucosa and remains without healing for at least 3 months .
the risk of orn is greatest at 6 - 12 months after radiation therapy and it is uncommon to see orn at radiation doses below 60 gy .
lytic destruction , cortical erosion and fragmentation of the mandible with associated fistulae and soft tissue thickening are some of the features seen on ct scan [ figure 12 ] . increased fdg avidity is seen in areas affected by orn [ figure 12 ] , but its specificity in differentiating viable tumor from radionecrosis is not reported to be very high .
orn can occur at rare sites such as the hyoid bone and increased fdg avidity may lead to the erroneous diagnosis of viable disease unless the physician is aware of its occurrence [ figure 13 ] .
characteristics osseous changes of orn and absence of associated soft tissue lesion make the diagnosis of radiation necrosis more likely
axial ct in soft tissue ( a ) and bone window settings ( b ) show soft tissue thickening , erosion and fragmentation of the mandible ( arrows ) .
coronal fused pet / ct shows intense fdg uptake restricted to right hemimandible ( arrowhead in c and d ) .
findings suggest the diagnosis of orn pitfalls due to treatment related complications - osteoradionecrosis [ orn ] .
axial fused pet / ct shows intense fdg uptake along the hyoid bone ( arrowhead in a and b ) .
axial ct shows subtle erosion of the hyoid bone along with a small collection and air pockets ( arrows in c and d ) .
sometimes , as a consequence of late effects of radiation therapy , there is a reduction of the normal physiological fdg uptake in structures such as the salivary glands and pharyngeal mucosal lining on the side of the therapy , leading to an appearance of asymmetric increased uptake in the normal tissues on the contralateral side [ figure 5 ] .
coronal and axial ( pet ) and fused pet / ct images show reduction in physiological uptake ( arrows in a , b , d ) on the left side due to long term effects of radiation therapy .
note the relative increase in physiological uptake in the parotid and submandibular glands and the oropharynx on the contralateral normal side which can mimic pathology ( arrowheads in a and d ) absence of physiological fdg uptake in the region of the surgically removed part and persistence of physiological uptake in the normal contralateral side produces an appearance of asymmetric tracer concentration that can mimic disease [ figure 6 ] .
occasionally , after partial resection of an organ such as the tongue , the remnant portion retains its physiological uptake , which appears focal in nature mimicking disease [ figure 7 ] .
after extensive jaw surgeries and reconstructive procedures , the altered mechanics of mastication can result in physiologically increased focal uptake in the adjacent masticator muscles that can be mistaken for disease [ figure 8 ] .
axial ct shows changes of right hemiglossectomy with a myocutaneous flap containing fat ( arrowhead in a ) .
axial pet and fusion pet / ct show physiological uptake in the remnant tongue which is focal and asymmetric in nature ( arrows in b and c ) and can potentially mimic disease pitfalls of due asymmetric physiological uptake .
coronal pet and fusion pet / ct show physiological uptake along the right side of the oral cavity and the floor of mouth which is asymmetric in nature ( arrows in b and c ) and can potentially mimic disease .
note the absence of normal physiological uptake on the left side ( arrowheads in b and c ) .
this pattern was seen more than a year after treatment pitfalls of due asymmetric physiological uptake .
axial pet and fusion pet / ct show focal asymmetric uptake in the left masseter which is physiological in nature ( arrows in a and b ) and is produced due to altered mechanics of mastication secondary to jaw surgery physiological uptake in the tongue tip and oral cavity arising due to close approximation of tongue and palate , buccal and gingival mucosae can be better resolved by performing certain maneuvers like puffing the cheek and placing a gauzegauze that can help mouth opening .
surgical complications occur early and include serous collections , infections , abscess and fistula formation , flap necrosis .
benign serous collections are self - limiting and should be distinguished from infected abscesses that might need a drainage procedure .
benign serous collections also called seromas usually do not show any fdg avidity unless they get infected . on fdg pet / ct abscesses
show a rim of tracer uptake in the periphery with a photopenic center which corresponds to a hypodense collection on ct with air pockets seen occasionally .
linear fdg uptake is seen along the fistulous communications associated with abscesses [ figure 9 ] .
these complications occur at the site of surgical resection and reconstructed flaps in the head  neck region .
rarely , one can come across infections / inflammations at the site of the donor flap in the chest or the abdominal wall and focal tracer uptake in this region can potentially mimic metastatic disease [ figure 10 ] .
axial fused pet / ct shows an intense focus of fdg uptake in the infratemporal fossa mimicking disease recurrence ( arrow in b ) .
corresponding contrast ct image shows a hypodense collection with an air pocket ( arrow in a ) suggestive of an abscess .
note the linear fdg uptake along the enhancing fistulous tract opening on the skin surface .
( arrowheads in a and b ) pitfalls due to treatment related complications ( surgery ) .
coronal mip image shows an intense focus of fdg uptake in the left hemithorax ( arrow in a ) which appears to be metastatic disease .
fused pet / ct shows focal uptake in the anterior chest wall ( arrow in c ) which was the site for the pmmc flap .
arrowhead in b ) radiation toxicity can lead to intense inflammatory changes in the mucosal structures and the soft tissues of the neck that can cause intense fdg accumulation [ figure 11 ] .
coronal pet ( b ) and fused pet / ct ( c ) shows intense fdg uptake in the naso , oro , and hypopharyngeal structures and the soft tissue of the neck bilaterally , with associated ill - defined fat stranding ( a  arrowhead ) .
such intense non - infective inflammation is seen on rare occasions after radiation and should not be confused with recurrence radiation induced necrosis can occur in bones ( osteoradionecrosis [ orn ] ) , cartilage ( chondronecrosis / laryngeal necrosis ) and even in irradiated soft tissues .
osteoradionecrosis ( orn ) occurs due to devitalization of irradiated bone which gets exposed through the skin and mucosa and remains without healing for at least 3 months .
the risk of orn is greatest at 6 - 12 months after radiation therapy and it is uncommon to see orn at radiation doses below 60 gy .
lytic destruction , cortical erosion and fragmentation of the mandible with associated fistulae and soft tissue thickening are some of the features seen on ct scan [ figure 12 ] .
increased fdg avidity is seen in areas affected by orn [ figure 12 ] , but its specificity in differentiating viable tumor from radionecrosis is not reported to be very high .
orn can occur at rare sites such as the hyoid bone and increased fdg avidity may lead to the erroneous diagnosis of viable disease unless the physician is aware of its occurrence [ figure 13 ] .
characteristics osseous changes of orn and absence of associated soft tissue lesion make the diagnosis of radiation necrosis more likely
( b ) show soft tissue thickening , erosion and fragmentation of the mandible ( arrows ) .
coronal fused pet / ct shows intense fdg uptake restricted to right hemimandible ( arrowhead in c and d ) .
findings suggest the diagnosis of orn pitfalls due to treatment related complications - osteoradionecrosis [ orn ] .
axial fused pet / ct shows intense fdg uptake along the hyoid bone ( arrowhead in a and b ) .
axial ct shows subtle erosion of the hyoid bone along with a small collection and air pockets ( arrows in c and d ) .
fdg pet / ct has been used to detect recurrent disease in the head and neck cancer patients .
it can confirm the site of clinically suspected local recurrence and determine its true extent .
recurrences at the site of the treated primary disease , subtle disease in the reconstructed flaps and nodal / soft tissue recurrence in the irradiated neck , the clinical assessment of which is difficult can be seen on pet / ct as enhancing lesions with intense fdg avidity [ figures 14 and 15 ] . at the same time
, it can pick up distant failures with a good accuracy and thus is performed before salvage surgery can potentially change the intended treatment plan .
in addition to common sites of distant metastases like the lungs and bones , pet / ct has the potential to unmask second primaries as well as certain unusual and rare metastatic sites such as the subcutaneous tissue , muscles , and feeding stomies [ figures 16 and 17 ] . recurrent disease . operated case of buccal cancer .
coronal mip shows intense foci of fdg uptake on the left side of the face and neck ( arrowhead and arrows in a ) .
axial fused pet / ct shows fdg avid recurrent nodule in the pmmc flap ( arrowhead in b and c ) and a metastatic cervical lymph node ( arrow in d and e ) recurrent disease .
sagittal mip shows foci of fdg uptake in the face ( arrows in a ) .
axial fused pet / ct ( arrowhead in b and c ) shows subtle uptake at the cut margin of the mandible due to local recurrence as well as metastatic deposit in the pterygopalatine fossa ( arrows in d and e ) distant metastases .
fusion pet / ct images show metastatic deposits in spleen ( b ) , lungs ( c ) , liver ( d ) , bone ( e ) , subcutaneous region ( f ) and muscle ( g ) distant metastases ( unusual sites ) . operated case of base tongue cancer with feeding gastrostomy .
sagittal pet and pet / ct images show a fdg avid mass in the anterior abdominal wall at the site of the gastrostomy ( arrows in a - b ) s / o metastatic deposit . local recurrence in the tongue base
fdg pet / ct is a useful modality in the post - treatment setting of head and neck cancers .
knowledge of certain characteristic imaging appearances and a few commonly encountered treatment related complications is important to avoid pitfalls in post - treatment imaging .
understanding the role of fdg pet / ct in detecting local recurrence and distant metastases plays a crucial role in deciding salvage treatment .

 majority of patients with head and neck cancer are treated with combined treatment regimes such as surgery , radiation therapy , and chemotherapy .
 the loss of structural symmetry and imaging landmarks as a result of therapy makes post - treatment imaging a daunting task on conventional modalities like computed tomography ( ct ) scan and magnetic resonance imaging ( mri ) as well as on 18 fluorine - fluorodeoxyglucose positron emission tomography / computed tomography ( 18f fdg pet / ct ) .
 combined multimodality treatment approach causes various tissue changes that give rise to a spectrum of findings on fdg pet / ct imaging , which are depicted in this atlas along with a few commonly encountered imaging pitfalls .
 the incremental value of fdg pet / ct in detecting locoregional recurrences in the neck as well as distant failures has also been demonstrated .


the bacterial isolates were collected throughout finland during 19982007 as described ( 10 ) . of
bionumerics version 5.1 software ( applied maths , kortrijk , belgium ) was used for sequence assembly .
allele numbers , sequence types ( sts ) , and clonal complexes ( ccs ) were assigned by using the pubmlst database ( 5 ) .
a serum sensitivity assay was conducted with 73 c. jejuni isolates according to a described protocol ( 8) . the same pool of serum samples from 10 healthy blood donors was used in all experiments . c. jejuni
all statistical analyses were performed by using graphpad prism version 4.03 ( graphpad software , san diego , ca , usa ) and pasw statistics version 18 ( spss inc . , chicago , il , usa ) .
a total of 72 c. jejuni isolates from blood were successfully typed by mlst ; 1 isolate had a mixed mlst pattern .
five isolates were in unassigned sts , and the rest were distributed among 11 ccs ( table ) .
genetic relatedness of these isolates was further confirmed by using pulsed - field gel electrophoresis .
* mlst , multilocus sequence typing ; st , sequence type ; nd , none detected .
however , bacteremia episodes caused by st-677 cc isolates were exclusively diagnosed during the seasonal peak during may  august ( figure 1 ) . of c. jejuni blood culture isolates detected during may  august , most ( 64% ) were st-677 cc .
furthermore , st-677 cc was the most prevalent complex in 4 geographic regions of finland . annual and seasonal distribution of 72 camplyobacter jejuni blood culture isolates belonging either to the st-677 clonal complex ( cc ) or to the other multilocus sequence typing ( mlst ) ccs .
one isolate with a mixed multilocus sequence type was not included . c. jejuni bacteremia was diagnosed during may  august ( m  a ) or during any other month of the year ( o ) .
susceptibility to human serum varied between c. jejuni isolates from different ccs ( figure 2 ) .
st-677 cc isolates were significantly less susceptible to human serum than all other isolates ( p<0.0001 ) .
st-45 cc isolates were significantly more susceptible to human serum than all other isolates ( p<0.0001 ) .
percentage of surviving bacteria in human serum for 73 blood culture isolates of campylobacter jejuni ( cj ) , grouped according to major multilocus sequence typing clonal complexes ( ccs ) , and for controls c. jejuni cj11168 and c. fetus .
we characterized a unique collection of 73 c. jejuni isolates from blood obtained during a nationwide study in finland over a 10-year period . despite the high population diversity of c. jejuni , nearly half of the isolates from blood showed clustering within the st-677 cc , a rare cc in other countries ( 12,13 ) .
thus , invasiveness of blood culture isolates could not be solely explained by their serum resistance , although the predominant isolates of st-677 cc were more serum resistant than other isolates . c. jejuni has high st diversity . as of may 2 , 2013 , a total of 6,564 sts were registered ( 5 ) . in this study , we detected clustering of c. jejuni isolates from blood in an uncommon st-677 cc .
further studies are needed to clarify whether bacterial characteristics might explain this finding . in our previous study , which included human fecal c. jejuni isolates obtained in finland from the mid-1990s through 2007 ,
which is nearly the same period as in the current nationwide study , 11.7% of the isolates belonged to st-677 cc ( 11 ) .
the 2 most prevalent ccs in that study , st-45 cc ( 43.6% of fecal isolates ) and st-21 cc ( 19.4% of fecal isolates ) , were detected only among 12 ( 16% ) and 10 ( 14% ) of blood culture isolates , respectively , in the present study .
st-45 cc and st-21 cc have been shown to be prevalent in several countries ( 4,13 ) . however , our results suggest that these 2 ccs are not common among c. jejuni isolates from blood in finland , which cluster more in the st-677 cc . on the basis of the present results , we speculate that st-677 cc might have a special invasive capability or has adapted to the environment in finland .
in general , complement - mediated killing of serum - susceptible isolates plays a major role in restricting access of pathogens to the bloodstream . however , available information about possible serum sensitivity of c. jejuni isolates from blood is scarce ( 8,9 ) . in our study of nonselected c. jejuni isolates from blood , susceptibility to human serum varied according to mlst cc . in conclusion , in this nationwide study during a 10-year period in finland , we found by mlst analysis that half of the bacteremia isolates of c. jejuni clustered within an otherwise uncommon st-677 cc . whether this finding indicates special adaptation of st-677 cc to finland or to the human bloodstream
our findings emphasize the role of using well - defined clinical materials in studies on bacterial pathogenicity and severity of human disease .

 campylobacter jejuni bacteria are highly diverse enteropathogens .
 seventy - three c. jejuni isolates from blood collected in finland were analyzed by multilocus sequence typing and serum resistance .
 approximately half of the isolates belonged to the otherwise uncommon sequence type 677 clonal complex .
 isolates of this clonal complex were more resistant than other isolates to human serum .


there appears to have been consensus in the past decades in classifying systemic sclerosis ( ssc ) according to extension of skin involvement as limited and diffuse , using the elbows and knees as  limits  to distinguish between them .
however , although this has been used to  dissect  two more or less distinct clinical subsets , there are patients who do not fit this classification and several others have been proposed [ 1 , 2 ] .
the growing demonstration that autoantibodies specific for ssc such as anticentromere , anti - scl-70 ( anti - topoisomerase 1 ) , and more recently a variety of antinucleolar antibodies , particularly anti - rna polymerase 3 , correlate with these subsets and/or visceral manifestations has led to them being used to
predict  clinical subsets in early disease and also raise awareness for the possibility of certain organ involvement ( anti - scl-70 and interstitial lung disease [ 3 , 4 ] , anticentromere associated with digital ulcers , debatably pulmonary hypertension , and anti - rna polymerase 3 with renal crisis ) .
decades ago , barnett classified ssc as type 1 ( only sclerodactyly ) , type 2 ( acrosclerosis - distal but may reach up to elbows and/or knees plus face ) , and type 3 ( diffuse skin involvement ) ( figure 1 ) .
patients with type 2 had an intermediate degree of both skin and organ involvement compared to type 1 ( less ) and type 3 ( more ) [ 810 ] .
this classification by barnett was extensively discussed in an editorial by masi many years later .
the division into three categories according to extension of skin involvement was not agreed to by others , who could not find real differences between what we could call types 1 and 2 as determined by barnett [ 1 , 2 ] . a similar classification but this time with 4 categories , proposed by giordano et al .
simultaneously , as reasonable stress was laid on early disease detection , the extent of cutaneous involvement was perhaps not considered so relevant , particularly as opposed to the autoantibodies as subset identifiers . however
, truth is that many patients present with evolving disease , and all of ssc  specific  antibodies are not widely available in many parts of the world , the best example being anti - rna polymerase .
many years ago but with a small number of patients , we noted that the limited subgroup could be , indeed , separated clinically as barnett had suggested according to skin involvement into patients with  only fingers ,  which we proposed to call crest , and those with skin distal to elbows and knees but proximal to mcp or mtp joints , which we proposed to call creat ( a instead of s for acrosclerosis ) . in that report , crest patients had more anticentromere antibodies than those with creat and the presence of anti - scl-70 occurred more frequently in the patients with creat than those with crest .
small numbers did not allow for detection of clinical differences . over the past decades ,
many of the larger series [ 416 ] and particularly the eustar database , one of the largest registries , have not differentiated subsets within the limited form ( scleroderma sine scleroderma excluded ) .
very recently however , in a very large series from a single center followed for years , the hopkins group emphasized just this , showing differences between the two  limited  groups and stressing the higher prevalence of lung disease and anti - scl-70 antibodies in the type 2 ( barnett ) or intermediate form when compared with type 1 , a behavior more similar to the diffuse form , and similar to what we had supported and barnett proposed years ago .
their conclusion was that dividing into limited and diffuse as we do now left out an intermediate form with different clinical and serological characteristics .
since over the years it was our feeling that this subsetting was clinically useful , we always registered extension of skin involvement in our patients , particularly identifying those with intermediate form within the lssc .
we therefore decided to examine the clinical and serologic characteristics of our patients with limited disease seen over the last decade to see if we could find differences within them according to the degree of skin involvement .
rheumatology section database , patients with icd 9 code 710.1 ( scleroderma ) in the inpatient hospital database , patients with the item : scleroderma , crest , or other synonyms as registered in the hospital 's electronic clinical history ; and laboratory database : patients with positive anticentromere , antinucleolar , or anti - scl-70 results .
all medical records so identified were then manually reviewed to confirm diagnosis and obtain demographic data such as date of onset , clinical characteristics , and serologic profile . only cases fulfilling acr 1980 criteria were included and were classified as diffuse or limited according to leroy 's criteria .
this difference in distribution was established considering the involvement of skin at its maximum extension at any point in the disease course . within the limited subset , they were separated into sclerodactyly ( only fingers ) and acrosclerosis ( fingers and up to elbows and/or knees , face ) ( barnett 's types 1 and 2 ) .
ssc clinical manifestations were considered to be present if predefined criteria were met during the course of the illness .
organ involvement definitions were the following : ( 1 ) upper gastrointestinal tract ( one or more of the following : manometry with esophageal dysmotility , esophagram with gastroesophagic reflux or peristaltic alterations , or upper endoscopy with esophagitis , ( 2 ) pulmonary hypertension ( ph ) : echocardiogram with estimated pulmonary systolic artery pressure equal to or greater than 40  mmhg or right heart catheterization with mean pulmonary artery pressure at rest over 25  mmhg , ( 3 ) interstitial lung disease ( ild ) : pulmonary interstitial disease observed in high resolution computerized tomography ( hrct ) or pulmonary function tests with vital forced capacity ( vfc ) lower than 70% of the expected and/or carbon monoxide lung diffusion ( dlco ) test under 80% of the expected , ( 4 ) echocardiographic alterations ( aside from ph ) : left or right ventricular diastolic dysfunction in absence of arterial hypertension or pulmonary hypertension , respectively , or pericardial effusion , ( 5 ) digital ulcers : active digital ulcers or pitting scars confirmed by a physician , ( 6 ) renal involvement : history of scleroderma renal crisis ( abrupt onset of accelerated arterial hypertension and/or rapidly progressive renal failure ) .
laboratory detection methods were indirect immunofluorescence on hep-2 cells ( antinuclear antibodies , antinucleolar , and anticentromere ) .
chi - square analysis was used to determine significant differences between sets of categorical data and fisher 's exact test when appropriate .
two hundred and thirty four ssc patients ( 216 females ) fulfilled the established criteria .
female / male ratio was 12  :  1 ; 24% had diffuse ssc and 76% limited ( 64% sclerodactyly and 12% acrosclerosis ) .
ten - year survival rate was 80% for limited and 70% for diffuse variants , respectively ( hr : 0.88 , 95% ci : 0.71.1 ) .

anti - scl-70 was present in 16% , anticentromere in 53% , and nucleolar ana in 7% of overall patients .
several characteristics in the acrosclerosis ( type 2 ) group were more similar to the diffuse patients than those with type 1 ( sclerodactyly ) . in patients with acrosclerosis , duration of raynaud 's was shorter , and they had significantly more anti - scl-70 and less anticentromere antibodies than those with type 1 .
in particular , interstitial lung disease ( ild ) was significantly more prevalent in type 2 group and similar to type 3 .
comparisons between patients with acrosclerosis and diffuse disease are presented in table 2 , showing no differences in clinical manifestations . as described elsewhere ,
autoantibodies were associated with visceral involvement and also with clinical subset . in univariate analysis ,
anticentromere antibodies were associated with pulmonary hypertension , or of 8.25 ( ci 1.935.7 ) , and inversely correlated with ild ( or 0.18 , ci 0.110.29 ) .
they were also associated with limited disease , or 34.4 ( ci 10.2116.6 ) . when performing multivariate analysis adjusting by disease subset , association between anticentromere and pulmonary hypertension was lost .
all of the patients with ph had lssc ( 11 with sclerodactyly and 1 with acrosclerosis ) except for one patient with diffuse disease with anticentromere antibodies . in summary ,
in multivariate analysis , both anti - scl-70 ( or 5.2 , ci 1.517.6 , p = 0.08 ) and diffuse disease ( or 4.1 , ci 1.213.5 , p = 0.021 ) were associated with ild .
these findings are very similar to those recently described by cottrell et al . within the
limited  patients ,  dissecting  between what could be barnett 's type 1 and 2 subsets .
our results support the initial description by barnett et al . that there is an  intermediate  form of ssc between the
some of these patients , albeit with limited scleroderma because skin involvement does not exceed elbows and/or knees , have a clinical behavior which can be described as intermediate between the strictly limited to fingers patients and those with diffuse disease . in particular , a sort of gradient from milder to more severe disease was confirmed in our patients , as suggested by barnett many years ago .
this was also shown by the hopkins group in a much larger number of patients . indeed , in type 2 as defined by barnett , serology may be more similar to the diffuse type and different from type 1
. the  gradient  is also reflected by the accompanying antibodies which further define visceral involvement such as pulmonary hypertension and interstitial lung disease .
these results appear to confirm that extension of skin involvement within limited ssc may identify two different subsets with clinical and serologic characteristics .
autoantibodies , in many cases present years prior to diagnosis and established skin disease , play an essential role here as predictors of clinical subsets and visceral involvement . however , some of these are not widely available .
furthermore , many patients present with established disease , although early , and in these a clinical approach contemplating extent of skin involvement coupled with the classic autoantibodies may indeed be useful and support a division within the limited form which may have useful clinical implications . a retrospective review of data in the large registries trying to document skin extension may or may not confirm this .
the problem may arise in the fact that since the extension of skin involvement within limited disease was not considered important , this may not have been adequately registered .
our smaller series completely agrees with the data shown by the hopkins group with a very large number of patients .
we believe identifying these differences within limited ssc is useful and  resuscitating  the intermediate form or barnett type 2 within limited ssc may contribute to a better clinical assessment of systemic sclerosis .

 objectives . to examine the characteristics of our patients with limited systemic sclerosis ( lssc ) for differences between barnett type 1 ( sclerodactyly only ) and type 2 or intermediate ( acrosclerosis - distal but may reach up to elbows and/or knees plus face ) subsets . methods .
 records of patients between january 1 , 2000 , and december 31 , 2011 , with ssc or those with anti - scl-70 , anticentromere , or antinucleolar antibodies were reviewed . only cases fulfilling acr 1980 criteria were included and classified as diffuse or limited according to leroy 's criteria .
 limited ssc was separated into sclerodactyly and acrosclerosis ( barnett 's types 1 and 2 ) . results . 234 ssc patients ( 216 females ) fulfilled criteria .
 female / male ratio was 12  :  1 ; 24% had dssc and 76% lssc ( 64% type 1 and 12% type 2 ) .
 total follow - up was 688 patient - years .
 within lssc , the type 2 group had significantly shorter duration of raynaud 's and more anti - scl-70 and less anticentromere antibodies .
 in particular , interstitial lung disease ( ild ) was significantly more prevalent in type 2 group and similar to type 3 . conclusions . these results appear to confirm that extension of skin involvement within limited ssc may identify two different subsets with clinical and serologic characteristics .


common failure of the root canal obturation process is because of the presence of gaps and porosities at the sealer / dentin interface .
several studies have shown that filled root canals can allow the re - colonization of micro - organisms .
the presence of micro - organisms and their products in the treated root canal can led to failure of the root canal treatment and the necessity of retreatment .
the analysis of the dentin / sealer interface allows the determination of which materials and filling techniques could obturate the root canals with less gaps and voids .
several microscopy techniques are currently used to evaluate the sealer / dentin interface , including stereomicroscopy , scanning electron microscopy ( sem ) , transmission electron microscopy , and confocal laser scanning microscopy ( clsm ) . in comparison to conventional sem , clsm has the advantage of providing detailed information about the presence and distribution of sealers or dental adhesives inside dentinal tubules in the total circumference of the root canal walls at relative low magnification as 100x through the use of fluorescent rhodamine marked sealers .
placement and activation of a sealer into the root canal system should be done in a manner which is predictable and completely covers the dentin walls . accepted
means of sealer placement include the use of endodontic files or reamers , lentulo spirals , gutta - percha cones , ultrasonic files , and counter - clockwise motion of rotary systems .
very few studies have been done to evaluate the efficacy of different methods of sealer placement and activation effectively .
mta fillapex is a sealer that is composed of mta and has excellent flow , radiopacity , easy handling , working time , and low solubility . because of its suitable physicochemical properties and excellent biocompatibility and bioactivity ,
hence , this study was planned to evaluate percentage and the depth of dentinal tubule sealer penetration of mta fillapex when agitated with three different techniques and to compare it with ah plus using clsm as the evaluative tool .
sixty teeth with single canal and free of cracks , caries , resorption , calcification , previous endodontic treatment , and less than 10- root curvature were selected and stored in distilled water until use . for standardization of the root length ( 10 mm )
, the crowns were resected with a diamond disc in a slow speed straight handpiece under constant water cooling .
the working length was determined by inserting # 15 k - file ( dentsply maillefer ) into the canal until it was just seen at the apical foramen and then 0.5 mm was subtracted from this length .
the roots were instrumented by using the protaper universal root canal files ( dentsply maillefer ) in a sequential manner from s1 till f5 .
canals were irrigated between files with 2 ml of 3% naocl ( sree rayalaseema alkalies and allies chemicals limited , india ) . to eliminate the smear layer 2 ml of 17% ethylenediaminetetraacetic acid ( edta ) ( ph 7.7 ) for 3 min was used , followed by a final rinse of 2 ml distilled water .
the roots were randomly divided into three groups on the basis of sealer activation technique utilized : g1 : ultrasonic ( woodpecker dte - d5 ultrasonic scaler , china ) ; g2 : lentulo spiral ( dentsply , maillefer ) ; g3 : counter - clockwise motion ( x smart , densply , maillefer , ballaigues , switzerland ) .
each group was further divided into two subgroups on the basis of type of sealer .
subgroup a utilized ah plus sealer while subgroup m utilized mta fillapex sealer . ah plus sealer and mta fillapex sealer were mixed according to the manufacturer instructions and to allow analysis under the clsm , each sealer was labelled with rhodamine b ( mayor diagnostics , mumbai , india ) to an approximate concentration of 0.1%(by weight ) .
group 1 ( g1 ) : the ultrasonic unit ( woodpecker dte - d5 ultrasonic scaler , china ) was used in endo mode with a satelec ultrasonic endodontic tip k15 sonofile ( dentsply tulsa ) for activation . the file was inserted 2 mm short of the working length inside the canal and was ultrasonically activated for 20 seconds .
gutta - percha was compacted 1 mm below the canal orifice and the teeth were sealed with cavit ( 3 m , espe ) . in g1a ah plus sealer and in g1 m , mta fillapex sealer was used .
group 2 ( g2 ) : a size 30 lentulo spiral ( dentsply , maillefer ) was selected that would not bind in the prepared canal and that would reach the prepared working length . the lentulo spiral was rotated at speed of 300 rpm keeping the instrument 2 mm from apex for 20 seconds .
thereafter , the obturation of canal was conducted as described for g1 . in g2a ah plus sealer and in g2 m , mta fillapex sealer was used .
group 3 ( g3 ) : f1 protaper file attached in handpiece of endodontic micromotor ( x - smart , dentsply tulsa ) was kept 2 mm short of apex and rotated at 300 rpm in reverse mode for 20 seconds .
thereafter , the obturation of canal was conducted as described for g1 . in g3a ah plus sealer and in g3 m , mta fillapex sealer was used .
the specimens were kept in an incubator at 37c and 100% humidity for 2 days .
each root was sectioned at 90- to the long axis by using diamond disc removing two , 1 mm sections at 3 mm and 6 mm from the apex .
coronal surface of each section was polished with sand paper ( politriz , arotec , cotia , sp , brazil ) .
the dentin segments were examined on a confocal microscope ( olympus fluoview fv 1000 ) .
the respective absorption and emission wave lengths for the rhodomine b were 540 nm and 590 nm .
dentin samples were analyzed using the 10x lens . to calculate the percentage of sealer penetration around the root canal , first each image was imported into the iob software and the circumference of root canal measured using its ruler tool .
next , areas along the canal walls in which the sealer penetrated into dentinal tubules were outlined and measured using the same method [ figure 1 ] .
subsequently , the percentage of root canal sealer penetration in that section was established . to determine the maximum depth of penetration , the point of deepest penetration was measured from the canal wall to the maximum depth of penetration [ figure 2 ] .
the effects of sealer agitation techniques and type of sealer on depth and percentage of sealer penetration were analyzed , by performing nonparametric kruskal - wallis for overall analysis , and a series of mann - whitney u tests for pairwise comparison using statistical package of social sciences ( spss ) statistics 20 software .
confocal laser scanning microscopic photograph showing calculation of percentage of penetration of sealer in the dentinal tubules ( original magnification 10 ) confocal laser scanning microscopic photograph showing calculation of depth of penetration of sealer in the dentinal tubules ( original magnification 10 )
sixty teeth with single canal and free of cracks , caries , resorption , calcification , previous endodontic treatment , and less than 10- root curvature were selected and stored in distilled water until use .
for standardization of the root length ( 10 mm ) , the crowns were resected with a diamond disc in a slow speed straight handpiece under constant water cooling .
the working length was determined by inserting # 15 k - file ( dentsply maillefer ) into the canal until it was just seen at the apical foramen and then 0.5 mm was subtracted from this length .
the roots were instrumented by using the protaper universal root canal files ( dentsply maillefer ) in a sequential manner from s1 till f5 .
canals were irrigated between files with 2 ml of 3% naocl ( sree rayalaseema alkalies and allies chemicals limited , india ) . to eliminate the smear layer 2 ml of 17% ethylenediaminetetraacetic acid ( edta ) ( ph 7.7 ) for
3 min was used , followed by a final rinse of 2 ml distilled water .
the roots were randomly divided into three groups on the basis of sealer activation technique utilized : g1 : ultrasonic ( woodpecker dte - d5 ultrasonic scaler , china ) ; g2 : lentulo spiral ( dentsply , maillefer ) ; g3 : counter - clockwise motion ( x smart , densply , maillefer , ballaigues , switzerland ) .
each group was further divided into two subgroups on the basis of type of sealer .
ah plus sealer and mta fillapex sealer were mixed according to the manufacturer instructions and to allow analysis under the clsm , each sealer was labelled with rhodamine b ( mayor diagnostics , mumbai , india ) to an approximate concentration of 0.1%(by weight ) .
group 1 ( g1 ) : the ultrasonic unit ( woodpecker dte - d5 ultrasonic scaler , china ) was used in endo mode with a satelec ultrasonic endodontic tip k15 sonofile ( dentsply tulsa ) for activation . the file was inserted 2 mm short of the working length inside the canal and was ultrasonically activated for 20 seconds . canal was obturated with protaper f5 gutta - percha cone .
gutta - percha was compacted 1 mm below the canal orifice and the teeth were sealed with cavit ( 3 m , espe ) . in g1a ah plus sealer and in g1 m , mta fillapex sealer was used .
group 2 ( g2 ) : a size 30 lentulo spiral ( dentsply , maillefer ) was selected that would not bind in the prepared canal and that would reach the prepared working length . the lentulo spiral was rotated at speed of 300 rpm keeping the instrument 2 mm from apex for 20 seconds .
thereafter , the obturation of canal was conducted as described for g1 . in g2a ah plus sealer and in g2 m , mta fillapex sealer was used .
group 3 ( g3 ) : f1 protaper file attached in handpiece of endodontic micromotor ( x - smart , dentsply tulsa ) was kept 2 mm short of apex and rotated at 300 rpm in reverse mode for 20 seconds .
thereafter , the obturation of canal was conducted as described for g1 . in g3a ah plus sealer and in g3 m , mta fillapex sealer was used .
the specimens were kept in an incubator at 37c and 100% humidity for 2 days .
each root was sectioned at 90- to the long axis by using diamond disc removing two , 1 mm sections at 3 mm and 6 mm from the apex .
coronal surface of each section was polished with sand paper ( politriz , arotec , cotia , sp , brazil ) .
the dentin segments were examined on a confocal microscope ( olympus fluoview fv 1000 ) .
the respective absorption and emission wave lengths for the rhodomine b were 540 nm and 590 nm .
dentin samples were analyzed using the 10x lens . to calculate the percentage of sealer penetration around the root canal , first each image was imported into the iob software and the circumference of root canal measured using its ruler tool .
next , areas along the canal walls in which the sealer penetrated into dentinal tubules were outlined and measured using the same method [ figure 1 ] .
subsequently , the percentage of root canal sealer penetration in that section was established . to determine the maximum depth of penetration , the point of deepest penetration was measured from the canal wall to the maximum depth of penetration [ figure 2 ] .
the effects of sealer agitation techniques and type of sealer on depth and percentage of sealer penetration were analyzed , by performing nonparametric kruskal - wallis for overall analysis , and a series of mann - whitney u tests for pairwise comparison using statistical package of social sciences ( spss ) statistics 20 software .
confocal laser scanning microscopic photograph showing calculation of percentage of penetration of sealer in the dentinal tubules ( original magnification 10 ) confocal laser scanning microscopic photograph showing calculation of depth of penetration of sealer in the dentinal tubules ( original magnification 10 )
the percentage and depth of sealer penetration of different groups and intergroup comparison are summarized in tables 1 and 2 , respectively . shows mean and standard deviation of depth and percentage of sealer penetration of various groups at 3 and 6 mm levels intergroup comparison of depth and percentage of sealer penetration at 6 and 3 mm levels mean percentage and depth of sealer penetration of mta fillapex and ah plus sealer was greatest when ultrasonics was used for agitation and statistically significant ( p < 0.001 ) than lentulo spiral and counter - clockwise agitation techniques .
irrespective of method used for agitation , the percentage and depth of sealer penetration for mta fillapex was significantly greater ( p < 0.001 ) than ah plus .
the percentage and depth of sealer penetration for mta fillapex and ah plus were greater and highly significant ( p < 0.001 ) at 6 mm than 3 mm .
removal of smear layer and use of sealer to attain and impervious seal between the core material and root canal walls is considered an essential step of root canal treatment .
sealers which can penetrate into the dentinal tubules exert bactericidal effect by having a closer contact with the residual bacteria within the tubules .
in addition , sealer plugs inside the dentinal tubules provide a mechanical interlocking , thereby improving the retention of the filling material and reducing the microleakage along the root canal walls .
thus , both percentage and depth of sealer penetration might influence the outcome or success rate of endodontic therapy .
factors influencing sealer depth penetration in dentinal tubules are presence / absence of dentinal permeability ( the number and the diameter of tubules ) , root canal dimension , presence of water , and physical and chemical properties of the sealer .
the compound effect of physical properties viz flow , surface tension , solubility , viscosity , chemical composition , and working and setting time may influence penetration .
flow which is defined as the ability of a sealer to penetrate in irregularities , lateral canals , or dentinal tubules of the root canal system is one of the main physical factors to influence the tubular penetration .
as most endodontic sealers are pseudoplastic , their flow increases with increase of shear rate . on comparison with conventional sealers patel dv et al . , and gharib sr et al . , found better depth of penetration of resin - based sealer in dentinal tubules .
mta fillapex has excellent biocompatibility and bioactivity and displayed significantly higher ph up to 7 days period than ah plus .
studies based on the physical properties reported significantly greater flow of mta fillapex than ah plus .
therefore , this comparative study was conducted to evaluate and compare the quality of sealing of ah plus and mta fillapex .
clinically , rapid insertion or activation of a pseudoplastic sealer into the canal would decrease viscosity and increase the flow of sealer .
as very few studies have been conducted on the effect of sealer activation / placement and activation on sealing ability of root canal sealers therefore in the present study three activation techniques ( ultrasonics , lentulo spiral , and rotary counter - clockwise motion ) were chosen and the sealer distribution was analyzed .
amount of sealer , extent of activating instrument , and time for activation were standardized to minimize the errors .
all the analyzed activation techniques failed to show a consistent adaptation of both the sealers to the total circumference of the root canal walls .
however , mta fillapex showed significantly better ( p < 0.001 ) percentage and depth of sealer penetration than ah plus with all the techniques of sealer activation .
kuc , ia et al . , also reported greater mta fillapex sealer penetration than ah plus .
zhou h et al . , and silva ej et al . , found mta fillapex significantly more flowable than ah plus and attributed difference in composition and smaller particle size of the sealer for this property .
application of ultrasonics for activation led to significantly more ( p < 0.001 ) percentage and depth of both the sealers and is accordance to guimaraes bm et al . , the explanation for this is that the oscillating files in ultrasonics transmits the acoustic microstreaming energy and cause a greater depth of dentinal sealer penetration and coverage of root canal walls in the same manner as it promotes the penetration of irrigants in an area of anatomic complexities and the dentinal tubules . although activation of both the sealers with lentulo spiral resulted in more percentage and depth of penetration as compare to counter - clockwise rotation however , the difference was statistically insignificant ( p > 0.05 ) .
this is one of the pioneer studies evaluating effect of methods of activation on mta fillapex so it was difficult to compare the results obtained with previous studies .
lentulo spiral rotates and the spring portion pushes the sealer centrifugally while in counter - clockwise rotation with a file , the sealer tends to pool toward the tip of file but is not forced toward the walls .
irrespective of technique of activation and type of sealer , the depth , and percentage of penetration of sealer was significantly better at the 6 mm level than 3 mm level .
these findings are similar to other studies and could be because the number and diameter of dentinal tubules decreases on descending apically in the root canal and superior removal of smear layer .
in addition , the apical dentin is irregular in direction and density ; even some areas are devoid of dentinal tubules .
under the parameters of present study , it can be concluded that mta fillapex sealer exhibited better percentage and depth of penetration in the radicular dentinal tubules than ah plus .
ultrasonic activation of pseudoplastic sealers can significantly increase its percentage and depth of penetration and level of root canal can affect both , percentage , and depth of penetration of sealers in the dentinal tubules .

 aim : to compare the effect of three root canal sealer activation techniques on percentage and depth of sealer penetration of mta fillapex and ah plus sealers.materials and methods : sixty teeth prepared till f5 protaper size were divided into three equal groups on the basis of sealer activation technique ( g1 : ultrasonics , g2 : lentulo spiral , and g3 : counter - clockwise rotary motion ) .
 each group was further divided into two equal subgroups on the basis of type of sealer used : ah plus ( denstply , konstanz , germany ) or mta fillapex ( angelus , londrina , pr , brazil ) and obturated with gutta - percha .
 horizontal sections at 3 and 6 mm from the apex were obtained and the percentage and depth of penetration of sealers into dentinal tubules were measured using confocal laser scanning microscopy ( clsm ) .
 statistical analysis was performed utilizing kruskal - wallis and mann - whitney u tests with a significance level of 5%.results : g1 showed significantly ( p < 0.001 ) high percentage and depth of sealer penetration than g2 and g3 while the difference was insignificant ( p > 0.05 ) between g2 and g3.conclusion:percentage and depth of sealer penetration are influenced by the type of sealer used sealer activation technique and by the root canal level .
 ultrasonic method of sealer activation and mta fillapex showed the best results .


vision 2020 is a joint initiative by the world health organization ( who ) and the international agency for the prevention of blindness , that aims to eliminate avoidable blindness by the year 2020 .
the vision 2020 strategy depends on the development of district level plans for the prevention of avoidable blindness.[26 ] india was the first country in the world to initiate a public funded program for the prevention of blindness as a national priority health problem .
population - based surveys have been the main stay of information regarding the effective implementation and monitoring of such eye care programs .
are expensive and time consuming . rapid assessment of avoidable blindness ( raab ) survey is cheap and easy means of getting population - based data on prevalence and causes of blindness in people aged more than 50 years .
raab also has the other utility of monitoring programs at the unit / district level.[911 ] kolar district in south karnataka , india , has an estimated population of around 1.5 million , 51% of the population being males and 29% being over 50 years .
the aim of the study was to conduct a raab study in persons aged more than 50 years in kolar district in order to estimate the prevalence and causes of blindness .
this was also to help the ophthalmology and community medicine departments of the medical institution to develop student capacity as well as expose them to scientific survey methods of generating evidence for planning of eye care services .
the survey was carried out by a team consisting of trained personnel from the departments of ophthalmology and community medicine , sri devaraj urs medical college , kolar , karnataka , india .
the survey was carried out between march and june 2011 ( 4 months ) , in accordance with the helsinki declaration .
written informed consent was obtained from all study participants , after explaining the purpose of the study in their local language .
sample size was determined using a prevalence estimate of 4% for blindness ( who definition of presenting vision < 20/400 in better eye ) among those aged over 50 years .
the prevalence estimate was assumed to be around 4% considering the recent raab survey conducted across india which gave prevalence of blindness using the same definition to be around 3.6% . using 95% confidence interval , 22.5% precision , design effect of 1.5 and 10% nonresponse rate , sample size was calculated to be 3017 , which would require 61 clusters of 50 people aged over 50 years . using the population data from the last census ( 2001 ) and the growth rate for 9 years , the population was estimated for end of 2010 and used as a sampling frame .
a list of wards and villages in urban and rural areas was prepared taluk ( revenue division ) wise . in each , the population size of people aged over 50 years was listed .
households within each cluster were selected by compact segment sampling . a map of the selected cluster was drawn and divided into equal segments that would give
segments were numbered and one segment was chosen by draw of lots . to be eligible for inclusion an individual had to reside in that household for at least the previous 6 months . in each cluster ,
the people in the selected cluster were briefed about the survey 23 days in advance by the local health worker along with the public relations officer of the team .
if an eligible person was not available during the survey , at least two more attempts were made to assess information .
if after repeated visits , examination could not be done , information of his visual status was obtained from his relatives or neighbors .
standard raab protocol was used for gathering information and for eye examination . a survey form comprising seven sections
the form consisted of general information ; vision and pin hole examination ; lens status ; principal cause of visual impairment ; history if not examined ; and barriers to uptake of cataract surgery and details of cataract surgery if operated .
visual acuity ( va ) was measured using a tumbling snellen - e chart using optotype size 20/60 on one side and 20/200 on the other .
all measurements were taken in full daylight with available correction . if visual acuity was less than 20/60 in either eye , pin hole vision was tested .
if presenting vision was < 20/60 , then pupil was dilated and ophthalmoscopy done to assess the cause of blindness .
the interobserver agreement between the two teams was good as observed by the kappa value ( > 0.60 ) .
double data entry and analysis was done using the raab software program version 4.02 . to check for errors made during data entry of the survey record forms ,
the data are entered twice by different data entry clerks in two separate databases and then compared .
sample size was determined using a prevalence estimate of 4% for blindness ( who definition of presenting vision < 20/400 in better eye ) among those aged over 50 years .
the prevalence estimate was assumed to be around 4% considering the recent raab survey conducted across india which gave prevalence of blindness using the same definition to be around 3.6% . using 95% confidence interval , 22.5% precision , design effect of 1.5 and 10% nonresponse rate , sample size was calculated to be 3017 , which would require 61 clusters of 50 people aged over 50 years .
using the population data from the last census ( 2001 ) and the growth rate for 9 years , the population was estimated for end of 2010 and used as a sampling frame .
a list of wards and villages in urban and rural areas was prepared taluk ( revenue division ) wise . in each , the population size of people aged over 50 years was listed .
households within each cluster were selected by compact segment sampling . a map of the selected cluster was drawn and divided into equal segments that would give
segments were numbered and one segment was chosen by draw of lots . to be eligible for inclusion
an individual had to reside in that household for at least the previous 6 months . in each cluster
, the survey team visited each household accompanied by local health worker to facilitate compliance .
the people in the selected cluster were briefed about the survey 23 days in advance by the local health worker along with the public relations officer of the team .
if an eligible person was not available during the survey , at least two more attempts were made to assess information .
if after repeated visits , examination could not be done , information of his visual status was obtained from his relatives or neighbors .
standard raab protocol was used for gathering information and for eye examination . a survey form comprising seven sections
vision and pin hole examination ; lens status ; principal cause of visual impairment ; history if not examined ; and barriers to uptake of cataract surgery and details of cataract surgery if operated .
visual acuity ( va ) was measured using a tumbling snellen - e chart using optotype size 20/60 on one side and 20/200 on the other .
all measurements were taken in full daylight with available correction . if visual acuity was less than 20/60 in either eye , pin hole vision was tested .
if presenting vision was < 20/60 , then pupil was dilated and ophthalmoscopy done to assess the cause of blindness .
the interobserver agreement between the two teams was good as observed by the kappa value ( > 0.60 ) .
double data entry and analysis was done using the raab software program version 4.02 . to check for errors made during data entry of the survey record forms ,
the data are entered twice by different data entry clerks in two separate databases and then compared .
a total of 3050 persons aged over 50 years were included in the study and 2907 ( 95.3% ) of them were examined . of them
the sampled population was relatively representative of the district population in terms of age and sex distribution .
the overall unadjusted prevalence of blindness from all causes in persons aged over 50 years was 3.9% ( 95% ci 2.75.1 ) .
table 1 shows the data regarding prevalence of blindness ( va < 20/400 in better eye with available correction ) ; severe visual impairment ( va < 20/200 20/400 in better eye with available correction ) and moderate visual impairment in persons ( va < 20/60 20/200 in better eye with available correction ) .
the age and sex adjusted prevalence of blindness , severe visual impairment , and moderate visual impairment was 3.4% , 3.1% , and 9.7% , respectively .
sample prevalence of blindness , severe visual impairment and moderate visual impairment  all causes untreated cataract was the primary cause of bilateral blindness ( 75% ) and severe visual impairment ( 73% ) .
refractive errors were the most common cause of moderate visual impairment ( 56% ) and second most common cause of severe visual impairment ( 11% ) .
avoidable causes accounted for 91% of all cases of blindness and 95% of cases of severe visual impairment [ table 2 ] .
causes of blindness ( va < 20/400 ) , severe visual impairment ( va 20/20020/400 ) and moderate visual impairment ( va 20/6020/200 ) the main barriers to uptake of cataract surgery were  no one to accompany ( 27% ) ;  waiting for maturity ( 27% ) ;  do not know how to get surgery done ( 10% ) ; and  old age no need ( 7% ) . the cataract surgical coverage ( csc ) in persons with va < 20/400 was high , with 82% of those requiring surgery having received the same .
for people with va < 20/200 and va < 20/60 , 72% and 64% , respectively of those needing surgery had received it [ table 3 ] . cataract surgical coverage by persons and eyes sex wise of the 707 eyes , which had received surgery , 641 ( 90.7% ) had an intra - ocular lens ( iol ) implantated .
among the patients with iol , 72.7% had va of 20/60 or more with available correction [ table 4 ]
. in patients operated less than 5 years back , 86% of patients with iol had best corrected va of more than or equal to 20/60 , when compared with 79% in patients with iol operated more than 5 years back . around 85% of patients were satisfied with the results of cataract surgery .
ocular comorbidities , operative complications and long - term complications were the principal reasons for poor outcome in eyes operated less than 3 years back .
postoperative visual acuity with available correction low vision ( persons with va < 20/60 in better eye with correction and not due to cataract , refractive error , or uncorrected aphakia ) was seen in 46 persons ( 1.6% ) .
in india , eye care planning and monitoring under the national program for control of blindness has been guided by population - based surveys .
rapid assessment techniques , which provide reliable estimates have been used for the past 16 years and have been the basis for district level programming .
the prevalence of blindness ( va < 20/400 ) was 3.9% in our study , which is almost similar to the raab study conducted across various states in india , which gave a prevalence of 3.6% .
the raab india study which covered gulbarga district in karnataka , gave a prevalence of 4.3% for that district .
the prevalence of blindness in our study is on the higher side when compared with other studies from kenya , bangladesh , china , palestinian territories and malawi where blindness prevalence ranged from 2.0% to 3.7% .
consequently , even though there has been a sharp increase in outreach programs and service delivery , this has been offset by the increasing elderly population as a result of increased life expectancy . in our study , almost 91% of blindness was avoidable .
untreated cataract still continues to be the major cause of blindness and severe visual impairment .
refractive errors and uncorrected aphakia are the other leading avoidable causes . despite the increased csc , there are an estimated 4700 people [ table 5 ] who are having bilateral cataract in kolar district , extrapolating the survey findings
. this cataract burden can only be reduced by proper taluk wise segmentation of the cataract blind and targeting the community outreach programs toward these areas . spectacle provision to the needy at a peripheral level by means of mobile refraction units and spectacle dispensing outfits
age and sex adjusted prevalence modified strategies in the form of extensive health awareness and health education campaigns through a decentralized approach involving all major health care providers at the grass root level , down to the remote rural level could be one of the positive steps in reducing this cataract burden .
waiting for maturity. this indirectly indicates that patients have been told to wait and sent back , which is an indicator of service delivery deficiency .
such people once turned back are unlikely to return back because of reasons such as lack of funds for conveyance to the hospital , loss of daily wages during the visit to the hospital , and relative lack of knowledge about when to return .
thus not only increasing the outreach programs but also concentrating on proper case selection , good surgical techniques , proper follow - up care and spectacle provision will definitely reduce the barriers and improve the outcome after cataract surgery .
this could be due to the fact that increased percentage of males seeks eye care services as reflected in the increased csc among males .
also females are less likely to report a need for sight than males.[1622 ] the strengths of our study was ready availability of taluk wise population data and the survey teams being trained by a certified raab trainer .
even though , there is a decline in prevalence of blindness , modified strategies need to be implemented to tackle the burden of untreated cataract .
raab done at regular intervals is an effective tool to quantify the problem of blindness and monitor the implementation of eye care programs .

 background : more than 90% of visual impairment can either be treated or avoided .
 rapid assessment of avoidable blindness methodology provides valid estimates in short time to assess magnitude and causes of blindness.aims:to estimate the prevalence and causes of blindness in persons above 50 years in kolar , south india , using the above methodology.materials and methods : sixty one clusters of 50 people aged above 50 years were selected by probability - proportionate to size sampling .
 participants were evaluated using a standardized survey form .
 persons with vision < 20/60 were dilated and examined by an ophthalmologist.results:of the 3050 people listed 2907 were examined ( 95.3% ) .
 prevalence of bilateral blindness in persons was 3.9% ; severe visual impairment 3.5% , and visual impairment 10.4% .
 untreated cataract was the leading cause of blindness ( 74.6% ) and severe visual impairment ( 73.3% ) .
 avoidable causes of blindness accounted for 91.2% of all blindness and 95.0% of severe visual impairment .
 waiting for maturity and  no one to accompany were the most common barriers to uptake of cataract surgery.conclusion:untreated cataract continues to be the leading cause of avoidable blindness .
 modified strategies need to be implemented to tackle the burden of cataract blindness .