Now that anyone (well, anyone with an invitation) with a spare $1,500 can get their very own Google Glass, the folks in Mountain View have thoughtfully released a software update for the famous wearable. We're frankly surprised Glass owners weren't able to do this before, but you can now look up your calendar directly from the headset. Simply say "ok glass, google my agenda" or "ok glass, what am I doing next week?" to see what's up next on your busy schedule. Another new feature is the ability to customize a location as either "home" or "work" so you can easily ask directions for either of those places.
Interestingly, the update also removed a feature. After finding out that people were long-pressing their touchpads by mistake, the company has turned that functionality off. Instead, Google recommends tapping the touchpad three times to initiate a search. Other upgraded goodies include a new tutorial setup and a screencast shortcut. So if you're lucky enough to own one of these headsets, go on and download the update from the thing on your noggin. And while you're at it, maybe figure out a way to invite us onto that Google barge.
BERLIN (AP) — U.S. military documents are increasing the mystery surrounding the more than 1,400 artworks found in a Munich apartment.
In the chaotic aftermath of World War II, the American military seized 20 boxes of art from German dealer Hildebrand Gurlitt in Aschbach in December 1945, according to documents located by The Associated Press in the U.S. National Archives in Washington.
Gurlitt had worked closely with the Nazi regime in the 1930s to sell art it considered "degenerate" to fill its war coffers.
American investigators at the time expressed doubts about Gurlitt's claims to the works, but they eventually decided that in most cases he was the rightful owner. So on Dec. 15, 1950, the U.S. returned 206 items to him: 115 paintings, 19 drawings and 72 "various other objects."
At least three of the artworks documented by the Americans have now re-surfaced, found hidden in the Munich apartment of Gurlitt's son, 80-year-old Cornelius Gurlitt, during a tax evasion probe that German prosecutors announced earlier this week.
The three paintings that the Americans returned to Cornelius' father in 1950 and which have showed up in the Munich trove are Max Liebermann's "Two Riders on the Beach;" Otto Dix's self-portrait and an allegorical painting by Marc Chagall.
Also found in the son's apartment were paintings, drawings, engravings, woodcuts and prints by Henri Matisse, Pablo Picasso, Pierre-Auguste Renoir, Oskar Kokoschka, and leading German artists Dix, Liebermann and Ernst Ludwig Kirchner.
Prosecutors gave few further details about the overall collection. Still, they said they found evidence that at least one item in the Munich apartment — a Henri Matisse painting of a sitting woman — was stolen by the Nazis from a French bank in 1942.
Christoph Zuschlag, an art historian at the University of Koblenz, said the American documents indicated U.S. investigators suspected right after the war that Gurlitt may have been in possession of looted art.
He said if German authorities published a full list of the find at the apartment, then experts could determine more quickly whether Gurlitt was the rightful owner.
"As a historian, I have to say pictures and information about all the art has to be published online immediately," he said. "A whole team of experts should work on this discovery and try to answer all the remaining open questions."
German prosecutors who are pursuing the tax case against Cornelius Gurlitt — whose whereabouts are currently unknown — said this week they had "concrete evidence" the artworks found in his apartment included both "degenerate art" seized from German museums and other works that may have been taken from individuals.
Museums, galleries and the heirs to those individuals, likely Jewish collectors forced to give up or sell their art at rock-bottom prices, could now have claims.
The Conference on Jewish Material Claims Against Germany, which administers restitution claims from victims of Nazi crimes, said the quickest and most efficient way to clear up any doubts would be for prosecutors to release a complete list.
Spokeswoman Hillary Kessler-Godin said the Claims Conference already has an online database of 20,000 looted objects based on the Nazis' own records that is searchable by owner, artist and other keywords. She said that could be easily used to determine if there are any claims on the Gurlitt collection.
"Our experts believe that a number of the works found in Munich could be in this database," Kessler-Godin said in an email. "Keeping the list a secret hinders the process of expeditious restitution."
When U.S. investigators questioned Hildebrand Gurlitt in 1945 about the origin of his collection, he told them that he had taken the art with him to Aschbach when he and his family fled Dresden after the city was devastated by Allied bombing in February 1945.
"All pictures I brought with me ... are the personal property of my family or myself," Gurlitt told the American interrogators, according to the U.S. documents. But he said it would be hard for him to prove his ownership of the collection, because all his records and correspondence were "destroyed in Dresden."
One U.S. investigator at the time noted inconsistencies in Gurlitt's claims to various paintings, while another said he "gave an impression of extreme nervousness and of offering only a minimum of information."
Marc Masurovsky, an expert on Nazi-era art transactions and co-founder of the Holocaust Art Restitution Project in Washington, said it is likely that Cold War-era investigators questioning a West German who had re-established himself in society probably just took the easy route.
"The political atmosphere was: We're just going to go back to work again and not ask lots of uncomfortable questions," he told the AP.
Masurovsky, who independently also found the National Archives documents and posted them on the Internet, said they raise more questions than they answer.
"The returned objects are 10 percent of the load" found in Munich, he said in a telephone interview. "Where did the other 90 percent come from? Did Gurlitt have several stashes of art? How many works did he already sell off?"
____
AP Investigative researcher Randy Herschaft contributed from New York.
Climate may play a role in the distribution and prevalence of trachoma
PUBLIC RELEASE DATE:
7-Nov-2013
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Contact: Katie Steels Katie.Steels@lshtm.ac.uk 44-207-927-2802 Public Library of Science
Call for investment in environmental strategies to eliminate the leading cause of preventable blindness
High temperatures and low rainfall are important factors which influence the occurrence and severity of the active stages of trachomathe most common cause of infectious blindnessaccording to a new study publishing November 7, 2013 in PLOS Neglected Tropical Diseases.
Researchers from the London School of Hygiene & Tropical Medicine and Sightsavers carried out the first systematic review to explore links between climate and trachoma. They found temperature and rainfall appear to influence the transmission of the infection in Africa, possibly because the eye-seeking flies which spread trachoma are more active at higher temperatures and are more abundant in areas with low rainfall.
Trachoma affects more than 40 million people, but it is estimated that 1.2 billion people worldwide live in areas where trachoma is found and are at risk of going blind. The bacterial infection is either passed from person to person by contact with infected secretions from the eyes or nose on hands and clothing, or by flies that land around children's eyes. Repeated infection in childhood can lead to blindness later in life.
The World Health Organization has resolved to eliminate blinding trachoma by 2020 and is working with governments and partners to roll out the SAFE strategy*, which includes surgery to distorted eyelids, antibiotics for active infection, facial cleanliness and environmental improvement to reduce the spread of the infection.
However to ensure the disease can be eliminated on schedule, a greater understanding of all factors that affect the incidence of the disease is needed. This study brings together the evidence on the role climate factors have to play for the first time.
Study co-author Dr Sari Kovats, Senior Lecturer at the London School of Hygiene & Tropical Medicine, said: "Our findings will assist international efforts to map where trachoma occurs as we now have a clearer understanding of the role that altitude, temperature and rainfall can play. We need to increase research on the environmental determinants of blinding trachoma in order to make control measures more effective now and in the future."
Dominic Haslam, Director of Policy at Sightsavers and co-author of the study, said: "This review underlines the urgent need for organizations such as Sightsavers to step-up global efforts to eliminate trachoma, before regional climate shifts make the current situation worse. The blinding disease already causes devastating suffering to millions around the world, and yet we know that by promoting face washing, better hygiene and sanitation, we can help manage the spread of trachoma in endemic communities."
The researchers stress the limitations of the study; only eight papers that were identified in the literature search met the standard for inclusion in the review and all these studies were undertaken in Africa (in Mali [2], Burkina Faso [1], Ethiopia [3], Tanzania [1] and South Sudan [1]), so the findings may not be generalizable to other areas. The study was co-funded by Sightsavers and Irish Aid.
###
* SAFE strategy: Surgery to upper eyelids, Antibiotics for active infection, Facial cleanliness, Environmental improvement, http://trachoma.org/safe-strategy
PLEASE ADD THE FOLLOWING LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002513
(Link will go live upon embargo lift)
Citation: Ramesh A, Kovats S, Haslam D, Schmidt E, Gilbert CE (2013) The Impact of Climatic Risk Factors on the Prevalence, Distribution, and Severity of Acute and Chronic Trachoma. PLoS Negl Trop Dis 7(11): e2513. doi:10.1371/journal.pntd.0002513
For any questions relating to the article, please contact:
Katie Steels
Media Manager
London School of Hygiene & Tropical Medicine
Katie.Steels@lshtm.ac.uk
+44(0)207 927 2802
Sarah Nelson
Senior Media & PR Officer
Sightsavers
snelson@sightsavers.org
+44(0)144 444 6637
Media Permissions
PLOS Journals publish under a Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits free reuse of all materials published with the article, so long as the work is cited (e.g., Kaltenbach LS et al. (2007) Huntington Interacting Proteins Are Genetic Modifiers of Neurodegeneration. PLOS Genet 3(5): e82. doi:10.1371/journal.pgen.0030082). No prior permission is required from the authors or publisher. For queries about the license, please contact the relative journal contact indicated here: http://www.plos.org/journals/embargopolicy.php
About the London School of Hygiene and Tropical Medicine
The London School of Hygiene & Tropical Medicine is a world-leading centre for research and postgraduate education in public and global health, with 3,500 students and more than 1,000 staff working in over 100 countries. The School is one of the highest-rated research institutions in the UK, and was recently cited as one of the world's top universities for collaborative research. The School's mission is to improve health and health equity in the UK and worldwide; working in partnership to achieve excellence in public and global health research, education and translation of knowledge into policy and practice. http://www.lshtm.ac.uk
About Sightsavers
Sightsavers is a registered UK charity (Registered charity numbers 207544 and SC038110) that works in more than 30 developing countries to prevent blindness, restore sight and advocate for social inclusion and equal rights for people with disabilities. http://www.sightsavers.org
About Irish Aid
Irish Aid is the Irish Government's programme for overseas development. It is managed by the Development Cooperation Division of the Department of Foreign Affairs and Trade. http://www.irishaid.ie
About PLOS Neglected Tropical Diseases
PLOS Neglected Tropical Diseases is a peer-reviewed, open-access journal devoted to the pathology, epidemiology, prevention, treatment, and control of the neglected tropical diseases, as well as public policy relevant to this group of diseases. All works published in PLOS Neglected Tropical Diseases are open access, which means that everything is immediately and freely available subject only to the condition that the original authorship and source are properly attributed. The Public Library of Science uses the Creative Commons Attribution License, and copyright is retained by the authors.
About the Public Library of Science
The Public Library of Science (PLOS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Climate may play a role in the distribution and prevalence of trachoma
PUBLIC RELEASE DATE:
7-Nov-2013
[
| E-mail
]
Share
Contact: Katie Steels Katie.Steels@lshtm.ac.uk 44-207-927-2802 Public Library of Science
Call for investment in environmental strategies to eliminate the leading cause of preventable blindness
High temperatures and low rainfall are important factors which influence the occurrence and severity of the active stages of trachomathe most common cause of infectious blindnessaccording to a new study publishing November 7, 2013 in PLOS Neglected Tropical Diseases.
Researchers from the London School of Hygiene & Tropical Medicine and Sightsavers carried out the first systematic review to explore links between climate and trachoma. They found temperature and rainfall appear to influence the transmission of the infection in Africa, possibly because the eye-seeking flies which spread trachoma are more active at higher temperatures and are more abundant in areas with low rainfall.
Trachoma affects more than 40 million people, but it is estimated that 1.2 billion people worldwide live in areas where trachoma is found and are at risk of going blind. The bacterial infection is either passed from person to person by contact with infected secretions from the eyes or nose on hands and clothing, or by flies that land around children's eyes. Repeated infection in childhood can lead to blindness later in life.
The World Health Organization has resolved to eliminate blinding trachoma by 2020 and is working with governments and partners to roll out the SAFE strategy*, which includes surgery to distorted eyelids, antibiotics for active infection, facial cleanliness and environmental improvement to reduce the spread of the infection.
However to ensure the disease can be eliminated on schedule, a greater understanding of all factors that affect the incidence of the disease is needed. This study brings together the evidence on the role climate factors have to play for the first time.
Study co-author Dr Sari Kovats, Senior Lecturer at the London School of Hygiene & Tropical Medicine, said: "Our findings will assist international efforts to map where trachoma occurs as we now have a clearer understanding of the role that altitude, temperature and rainfall can play. We need to increase research on the environmental determinants of blinding trachoma in order to make control measures more effective now and in the future."
Dominic Haslam, Director of Policy at Sightsavers and co-author of the study, said: "This review underlines the urgent need for organizations such as Sightsavers to step-up global efforts to eliminate trachoma, before regional climate shifts make the current situation worse. The blinding disease already causes devastating suffering to millions around the world, and yet we know that by promoting face washing, better hygiene and sanitation, we can help manage the spread of trachoma in endemic communities."
The researchers stress the limitations of the study; only eight papers that were identified in the literature search met the standard for inclusion in the review and all these studies were undertaken in Africa (in Mali [2], Burkina Faso [1], Ethiopia [3], Tanzania [1] and South Sudan [1]), so the findings may not be generalizable to other areas. The study was co-funded by Sightsavers and Irish Aid.
###
* SAFE strategy: Surgery to upper eyelids, Antibiotics for active infection, Facial cleanliness, Environmental improvement, http://trachoma.org/safe-strategy
PLEASE ADD THE FOLLOWING LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002513
(Link will go live upon embargo lift)
Citation: Ramesh A, Kovats S, Haslam D, Schmidt E, Gilbert CE (2013) The Impact of Climatic Risk Factors on the Prevalence, Distribution, and Severity of Acute and Chronic Trachoma. PLoS Negl Trop Dis 7(11): e2513. doi:10.1371/journal.pntd.0002513
For any questions relating to the article, please contact:
Katie Steels
Media Manager
London School of Hygiene & Tropical Medicine
Katie.Steels@lshtm.ac.uk
+44(0)207 927 2802
Sarah Nelson
Senior Media & PR Officer
Sightsavers
snelson@sightsavers.org
+44(0)144 444 6637
Media Permissions
PLOS Journals publish under a Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits free reuse of all materials published with the article, so long as the work is cited (e.g., Kaltenbach LS et al. (2007) Huntington Interacting Proteins Are Genetic Modifiers of Neurodegeneration. PLOS Genet 3(5): e82. doi:10.1371/journal.pgen.0030082). No prior permission is required from the authors or publisher. For queries about the license, please contact the relative journal contact indicated here: http://www.plos.org/journals/embargopolicy.php
About the London School of Hygiene and Tropical Medicine
The London School of Hygiene & Tropical Medicine is a world-leading centre for research and postgraduate education in public and global health, with 3,500 students and more than 1,000 staff working in over 100 countries. The School is one of the highest-rated research institutions in the UK, and was recently cited as one of the world's top universities for collaborative research. The School's mission is to improve health and health equity in the UK and worldwide; working in partnership to achieve excellence in public and global health research, education and translation of knowledge into policy and practice. http://www.lshtm.ac.uk
About Sightsavers
Sightsavers is a registered UK charity (Registered charity numbers 207544 and SC038110) that works in more than 30 developing countries to prevent blindness, restore sight and advocate for social inclusion and equal rights for people with disabilities. http://www.sightsavers.org
About Irish Aid
Irish Aid is the Irish Government's programme for overseas development. It is managed by the Development Cooperation Division of the Department of Foreign Affairs and Trade. http://www.irishaid.ie
About PLOS Neglected Tropical Diseases
PLOS Neglected Tropical Diseases is a peer-reviewed, open-access journal devoted to the pathology, epidemiology, prevention, treatment, and control of the neglected tropical diseases, as well as public policy relevant to this group of diseases. All works published in PLOS Neglected Tropical Diseases are open access, which means that everything is immediately and freely available subject only to the condition that the original authorship and source are properly attributed. The Public Library of Science uses the Creative Commons Attribution License, and copyright is retained by the authors.
About the Public Library of Science
The Public Library of Science (PLOS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
[
| E-mail
Share
]
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
The question of how humans process the flood of electronic media was a central part of the work of Stanford University sociology professor Clifford Nass, who died recently. Citing multiple studies, Nass said people often overestimate their ability to multitask.
iStockphoto.com
The question of how humans process the flood of electronic media was a central part of the work of Stanford University sociology professor Clifford Nass, who died recently. Citing multiple studies, Nass said people often overestimate their ability to multitask.
iStockphoto.com
Clifford Nass, the Stanford University sociologist who helped pioneer studies that undermined ideas about multitasking, has died at age 55. The man who dedicated his career to thinking about how humans live in a digital age died after taking part in a hike near Lake Tahoe Saturday.
At Stanford, Nass was "a larger than life character," his colleague professor Byron Reeves tells NPR's All Things Considered. Reeves says Nass "was just incredibly enthusiastic about his work, about students."
As for Nass' legacy, Reeves says his colleague worked to trace how technology has moved "from tools to social actors," in which everything from robots and computer-laden cars can now use interactive software to present visual cues.
"These were essentially social responses," Reeves says. "And humans were built for those kinds of social responses, and to recognize that kind of social interaction and to participate... and they did."
A graduate of Princeton University with degrees in mathematics and sociology, Nass worked as a computer scientist at Intel Corp. before beginning his work at Stanford, according to the Stanford Report. The school paper adds, "He was also a professional magician."
Nass's work on multitasking was just one part of how he examined the way people interact with technology. He also wrote books about voice recognition software, and the ways people think about computers and television.
But it was his research — and his skepticism — about multitasking that drew the most notice. And Nass didn't have to look far for test subjects.
"The top 25 percent of Stanford students are using four or more media at one time whenever they're using media," he told NPR's Science Friday this past May. "So when they're writing a paper, they're also Facebooking, listening to music, texting, Twittering, et cetera. And that's something that just couldn't happen in previous generations even if we wanted it to."
To anyone who claims they're able to multitask, to concentrate on multiple things at once while still thinking creatively and using their memory, Nass had a ready response.
"They're basically terrible at all sorts of cognitive tasks, including multitasking," he told Science Friday's Ira Flatow, citing a raft of scientific research. In Nass's view, people who say they're good at multitasking because they do it all the time are like smokers who say they've always smoked — so it can't be bad form them.
"People who multitask all the time can't filter out irrelevancy. They can't manage a working memory. They're chronically distracted," Nass said. "They initiate much larger parts of their brain that are irrelevant to the task at hand. And even - they're even terrible at multitasking. When we ask them to multitask, they're actually worse at it. So they're pretty much mental wrecks."
Nass also warned that the mental strain of taking in an ever-increasing load of information through electronic media hasn't been fully realized.
"Companies now create policies that force their employees to multitask," he said, according to the Stanford Report. "It's an OSHA (Occupational Safety and Health Administration) problem. It's not safe for people's brains."
Another of Nass' experiments revolved around how people see virtual versions of themselves — particularly when given the option of giving themselves feedback. Here's how he explained the results of a study during a 2010 appearance on NPR:
"We've done studies, for example, in which... you take a test on a computer and the feedback is either given not only by your own voice but your own face, saying you did a good job or you did a bad job, or someone else has.
"And people not only thought they did better when they got feedback from their own voice, they thought their own face and voice was more intelligent, more likable, and in fact they remembered more of the positive and fewer of the negative comments."
Showing the fashion world that it has nothing on her, the irresistibly sexy Kate Upton posed for a nude body paint photo shoot for Sports Illustrated Magazine.
Looking perfect, and showing off her signature curves without the burdens of clothing, the 21-year-old said at the beginning of the shoot, "The day here is perfect. The weather is amazing, and I'm happy to take off my clothes just for a little warm weather!"
The sensual supermodel sported an intricately painted bikini, which acted as a throwback to the cover of the swimsuit edition's 2000 model, Daniela Pestova.
"I definitely feel naked," the GQ covergirl said during the shoot. "Because I am. It's just paint! She posed in several different stances, and her artists gave a brief description of how difficult and elaborate her painted swimsuit was to create. Watch below!
FILE - This Oct. 7, 2013 file photo shows American actress Kate Mulgrew from the Netflix original series "Orange Is The New Black," in New York. Mulgrew, known for her roles in “Star Trek: Voyager” and “Ryan’s Hope” has a deal with Little, Brown and Company, the publisher announced Thursday. Mulgrew, 58, will tell the story of being an unmarried mother who gave up her daughter for adoption during the start of her career, her reunion with her daughter in 2001 and “the costs and rewards of a passionate life.” The book is currently untitled and scheduled to come out in May 2015. (Photo by Diane Bondareff/Invision/AP, File)
NEW YORK (AP) — Kate Mulgrew has figured out a way to introduce her two great passions, acting and writing, to each other: She's working on a memoir.
Little, Brown and Company announced a deal Thursday with Mulgrew, the actress known for her roles in "Star Trek: Voyager" and "Ryan's Hope." The 58-year-old Mulgrew will tell the story of being an unmarried mother who gave up her daughter for adoption during the start of her career, her reunion with her daughter in 2001 and "the costs and rewards of a passionate life."
The book is untitled and scheduled to come out in May 2015.
Mulgrew also stars in the Netflix series "Orange is the New Black" and has been in such stage productions as "Tea at Five" and "Equus."
UMMS researchers answer century old question about 3D structure of mitotic chromosomes
PUBLIC RELEASE DATE:
7-Nov-2013
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Contact: Jim Fessenden james.fessenden@umassmed.edu 508-856-2000 University of Massachusetts Medical School
New evidence shows that chromosomes assemble into linearly organized, compressed chromatin loops during the metaphase stage of cell division
WORCESTER, MA Using three dimensional modeling techniques, advanced computer simulation and next generation sequencing technology, faculty at the University of Massachusetts Medical School (UMMS) and the Massachusetts Institute of Technology (MIT) have resolved a long-standing debate that has consumed scientists ever since chromosomes were first observed under the light microscope by Walther Flemming in 1878.
In an article that appears in the online edition of Science, UMMS Professor Job Dekker, PhD, and colleagues show new evidence for a general principal of condensed, mitotic chromosome organization and structure that is highly adaptable and common to all cells. This new insight into how chromosomes are disassembled and reassembled during cell division will allow researchers to begin answering basic questions about epigenetic inheritance, as well as human disease such as chromosome disorders and cancer.
"Over the last several decades there have been conflicting theories for how the DNA is organized inside these chromosomes," said Dr. Dekker, co-director of the Program in Systems Biology at UMMS and senior author of the Science study. "We now have a model that incorporates this seemingly contradictory data and points to a single and simple process for condensed chromosome organization across all cell types. With this knowledge, we can begin asking very specific questions about how inheritance works and what happens when the process goes awry."
One of the most widely recognized biological structures in the cell, the tightly wound and elongated chromosome with its classic X-shaped structure can be easily discerned under a microscope and has been a common image in text books and popular scientific literature for decades. Despite this prevalence, technical limitations in microscopic studies have led to competing models for how the DNA is organized inside these chromosomes.
In its normal state, a cell's DNA is distributed in the cell nucleus over a relatively large area. Previous work from Dekker and colleagues had shown that points of interaction along the chromosome influence gene expression and are the reason why different cell types are organized differently in three dimensions. But in order to separate and be distributed successfully to each daughter cell, the chromosomes need to be tightly condensed and neatly packaged for transport and transmission to daughter cells.
One set of theories posed that the long DNA molecules are coiled up hierarchically into successively thicker fibers to ultimately form the sausage-like mitotic chromosomes. An alternate set of models proposed that the DNA forms a series of loops that are then attached to a linear axial structure that forms the backbone of the chromosome.
Different lines of experimental evidence supported both models, preventing ruling either theory in or out. In order to isolate the 3D structure of the chromosome during metaphase, the authors used a combination of chromosome conformation capture technologies (3C, 5C and Hi-C) developed by the Dekker lab over the last decade to map the points of contact along the mitotic chromosome in different cell types synchronized to divide at the same time. The complex sets of data this yielded provided the backbone for understanding the three dimensional structure and spatial organization of these chromosomes.
Next, Dekker and the team, led by Leonid Mirny, PhD, associate professor at the Massachusetts Institute of Technology, developed sophisticated computer simulations using polymer models of the DNA molecule for the two competing theories for mitotic chromosome organization. Plugging each model into the simulation, Dekker, Mirny and colleagues found that their chromosome conformation capture data was inconsistent with the classical, hierarchical model. Instead, they found that during metaphase the chromosome was being packaged in a two phase process. In the first phase, chromatin loops of 80,000 to 120,000 DNA base pairs form, radiating out from a scaffold and compacting the chromosome linearly. This was followed by axial compression of the chromosome, much like a spring being compressed, resulting in a neat, tightly folded package.
"Each cell type, whether blood, skin or liver cell, has a unique structure and organization that is closely tied to gene expression and function," said Dekker. "When the cell begins to divide that structure is disassembled. The specific patterns or organization tied to cell type are stripped away and the universal mitotic chromosome is formed. The process results in each cell being condensed and repackaged in a way that is common across cells types and points to a fundamental process of cell biology."
"When you look at the condensed chromosome it appears to be highly organized," said Dekker. "But the truth is that the process is very variable and adaptable because these chromatin loops form randomly along the chromosomes, which makes the process incredibly robust and adaptable."
Natalia Naumova, PhD, a postdoctoral fellow at UMMS and one of the lead authors of the study said, "We didn't expect that the chromosome would be organized this way. This stochastic process, which is locally random, results more globally in a high degree of stability and robustness, which is needed for cells to divide successfully."
The next step for Dekker, Mirny and their teams is to determine what, precisely, is guiding the disassembling and reassembling of the chromosome. "Because most transcription largely ceases in mitosis, and many proteins dissociate from the chromosome, something has to be responsible for reassembling chromosomes after cell division according to their cell type. Understanding the organization of the mitotic chromosome will help to understand how things go wrong in disease caused by chromosome disorder such as cancer or Down syndrome."
###
About the University of Massachusetts Medical School
The University of Massachusetts Medical School (UMMS), one of five campuses of the University system, is comprised of the School of Medicine, the Graduate School of Biomedical Sciences, the Graduate School of Nursing, a thriving research enterprise and an innovative public service initiative, Commonwealth Medicine. Its mission is to advance the health of the people of the Commonwealth through pioneering education, research, public service and health care delivery with its clinical partner, UMass Memorial Health Care. In doing so, it has built a reputation as a world-class research institution and as a leader in primary care education. The Medical School attracts more than $240 million annually in research funding, placing it among the top 50 medical schools in the nation. In 2006, UMMS's Craig C. Mello, PhD, Howard Hughes Medical Institute Investigator and the Blais University Chair in Molecular Medicine, was awarded the Nobel Prize in Physiology or Medicine, along with colleague Andrew Z. Fire, PhD, of Stanford University, for their discoveries related to RNA interference (RNAi). The 2013 opening of the Albert Sherman Center ushered in a new era of biomedical research and education on campus. Designed to maximize collaboration across fields, the Sherman Center is home to scientists pursuing novel research in emerging scientific fields with the goal of translating new discoveries into innovative therapies for human diseases.
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UMMS researchers answer century old question about 3D structure of mitotic chromosomes
PUBLIC RELEASE DATE:
7-Nov-2013
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Contact: Jim Fessenden james.fessenden@umassmed.edu 508-856-2000 University of Massachusetts Medical School
New evidence shows that chromosomes assemble into linearly organized, compressed chromatin loops during the metaphase stage of cell division
WORCESTER, MA Using three dimensional modeling techniques, advanced computer simulation and next generation sequencing technology, faculty at the University of Massachusetts Medical School (UMMS) and the Massachusetts Institute of Technology (MIT) have resolved a long-standing debate that has consumed scientists ever since chromosomes were first observed under the light microscope by Walther Flemming in 1878.
In an article that appears in the online edition of Science, UMMS Professor Job Dekker, PhD, and colleagues show new evidence for a general principal of condensed, mitotic chromosome organization and structure that is highly adaptable and common to all cells. This new insight into how chromosomes are disassembled and reassembled during cell division will allow researchers to begin answering basic questions about epigenetic inheritance, as well as human disease such as chromosome disorders and cancer.
"Over the last several decades there have been conflicting theories for how the DNA is organized inside these chromosomes," said Dr. Dekker, co-director of the Program in Systems Biology at UMMS and senior author of the Science study. "We now have a model that incorporates this seemingly contradictory data and points to a single and simple process for condensed chromosome organization across all cell types. With this knowledge, we can begin asking very specific questions about how inheritance works and what happens when the process goes awry."
One of the most widely recognized biological structures in the cell, the tightly wound and elongated chromosome with its classic X-shaped structure can be easily discerned under a microscope and has been a common image in text books and popular scientific literature for decades. Despite this prevalence, technical limitations in microscopic studies have led to competing models for how the DNA is organized inside these chromosomes.
In its normal state, a cell's DNA is distributed in the cell nucleus over a relatively large area. Previous work from Dekker and colleagues had shown that points of interaction along the chromosome influence gene expression and are the reason why different cell types are organized differently in three dimensions. But in order to separate and be distributed successfully to each daughter cell, the chromosomes need to be tightly condensed and neatly packaged for transport and transmission to daughter cells.
One set of theories posed that the long DNA molecules are coiled up hierarchically into successively thicker fibers to ultimately form the sausage-like mitotic chromosomes. An alternate set of models proposed that the DNA forms a series of loops that are then attached to a linear axial structure that forms the backbone of the chromosome.
Different lines of experimental evidence supported both models, preventing ruling either theory in or out. In order to isolate the 3D structure of the chromosome during metaphase, the authors used a combination of chromosome conformation capture technologies (3C, 5C and Hi-C) developed by the Dekker lab over the last decade to map the points of contact along the mitotic chromosome in different cell types synchronized to divide at the same time. The complex sets of data this yielded provided the backbone for understanding the three dimensional structure and spatial organization of these chromosomes.
Next, Dekker and the team, led by Leonid Mirny, PhD, associate professor at the Massachusetts Institute of Technology, developed sophisticated computer simulations using polymer models of the DNA molecule for the two competing theories for mitotic chromosome organization. Plugging each model into the simulation, Dekker, Mirny and colleagues found that their chromosome conformation capture data was inconsistent with the classical, hierarchical model. Instead, they found that during metaphase the chromosome was being packaged in a two phase process. In the first phase, chromatin loops of 80,000 to 120,000 DNA base pairs form, radiating out from a scaffold and compacting the chromosome linearly. This was followed by axial compression of the chromosome, much like a spring being compressed, resulting in a neat, tightly folded package.
"Each cell type, whether blood, skin or liver cell, has a unique structure and organization that is closely tied to gene expression and function," said Dekker. "When the cell begins to divide that structure is disassembled. The specific patterns or organization tied to cell type are stripped away and the universal mitotic chromosome is formed. The process results in each cell being condensed and repackaged in a way that is common across cells types and points to a fundamental process of cell biology."
"When you look at the condensed chromosome it appears to be highly organized," said Dekker. "But the truth is that the process is very variable and adaptable because these chromatin loops form randomly along the chromosomes, which makes the process incredibly robust and adaptable."
Natalia Naumova, PhD, a postdoctoral fellow at UMMS and one of the lead authors of the study said, "We didn't expect that the chromosome would be organized this way. This stochastic process, which is locally random, results more globally in a high degree of stability and robustness, which is needed for cells to divide successfully."
The next step for Dekker, Mirny and their teams is to determine what, precisely, is guiding the disassembling and reassembling of the chromosome. "Because most transcription largely ceases in mitosis, and many proteins dissociate from the chromosome, something has to be responsible for reassembling chromosomes after cell division according to their cell type. Understanding the organization of the mitotic chromosome will help to understand how things go wrong in disease caused by chromosome disorder such as cancer or Down syndrome."
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About the University of Massachusetts Medical School
The University of Massachusetts Medical School (UMMS), one of five campuses of the University system, is comprised of the School of Medicine, the Graduate School of Biomedical Sciences, the Graduate School of Nursing, a thriving research enterprise and an innovative public service initiative, Commonwealth Medicine. Its mission is to advance the health of the people of the Commonwealth through pioneering education, research, public service and health care delivery with its clinical partner, UMass Memorial Health Care. In doing so, it has built a reputation as a world-class research institution and as a leader in primary care education. The Medical School attracts more than $240 million annually in research funding, placing it among the top 50 medical schools in the nation. In 2006, UMMS's Craig C. Mello, PhD, Howard Hughes Medical Institute Investigator and the Blais University Chair in Molecular Medicine, was awarded the Nobel Prize in Physiology or Medicine, along with colleague Andrew Z. Fire, PhD, of Stanford University, for their discoveries related to RNA interference (RNAi). The 2013 opening of the Albert Sherman Center ushered in a new era of biomedical research and education on campus. Designed to maximize collaboration across fields, the Sherman Center is home to scientists pursuing novel research in emerging scientific fields with the goal of translating new discoveries into innovative therapies for human diseases.
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