#Switching on one-shot learning in the brain This type of one-shot learning is more than handy
when it comes to survival--think of an animal quickly learning to avoid a type of poisonous berry.
In that case, jumping to the conclusion that the fruit was to blame for a bout of illness might help the animal steer clear of the same danger in the future.
for example, you might blame a new food you tried for an illness when in fact it was harmless,
Scientists have suspected long that one-shot learning involves a different brain system than gradual learning, but could not explain what triggers this rapid learning
or how the brain decides which mode to use at any one time. Now Caltech scientists have discovered that uncertainty in terms of the causal relationship
and then activate one-shot learning when needed. The findings, described in the April 28 issue of the journal PLOS Biology,
could lead to new approaches for helping people learn more efficiently. The work also suggests that an inability to properly attribute cause
and effect might lie at the heart of some psychiatric disorders that involve delusional thinking, such as schizophrenia."
"Many have assumed that the novelty of a stimulus would be the main factor driving one-shot learning,
but our computational model showed that causal uncertainty was more important, "says Sang Wan Lee,
a postdoctoral scholar in neuroscience at Caltech and lead author of the new paper.""If you are uncertain,
"The researchers used a simple behavioral task paired with brain imaging to determine where in the brain this causal processing takes place.
and then couples with the hippocampus to switch on one-shot learning, as needed. Indeed, a switch is an appropriate metaphor,
says Shinsuke Shimojo, Caltech's Gertrude Baltimore Professor of Experimental psychology. Since the hippocampus is known to be involved in so-called episodic memory, in which the brain quickly links a particular context with an event
the researchers hypothesized that this brain region might play a role in one-shot learning. But they were surprised to find that the coupling between the VLPFC
20 of those participants completed the study in the Caltech Brain imaging Center, where their brains were monitored using functional Magnetic resonance imaging.
The task consisted of multiple trials. During each trial, participants were shown a series of five images one at a time on a computer screen.
Over the course of the task, some images appeared multiple times, while others appeared only once or twice.
The researchers hypothesize that the VLPFC acts as a controller mediating the one-shot learning process.
the researchers are intrigued by the fact that the VLPFC is very close to another part of the ventrolateral prefrontal cortex that they previously found to be involved in helping the brain to switch between two other forms of learning--habitual and goal-directed learning,
"says coauthor John O'Doherty, professor of psychology and director of the Caltech Brain imaging Center r
#A smartphone with ultimate macro feature: DNA-scanning fluorescent microscope If you thought scanning one of those strange,
square QR codes with your phone was advanced somewhat, hold on to your seat. Researchers at the University of California, Los angeles (UCLA) have developed recently a device that can turn any smartphone into a DNA-scanning fluorescent microscope."
"A single DNA molecule, once stretched, is about two nanometers in width, "said Aydogan Ozcan, HHMI Chancellor Professor, UCLA."For perspective,
that makes DNA about 50,000 times thinner than a human hair. Currently, imaging single DNA molecules requires bulky, expensive optical microscopy tools,
which are confined mostly to advanced laboratory settings. In comparison, the components for my device are significantly less expensive."
"Enter Ozcan's smartphone attachment--an external lens, thin-film interference filter, miniature dovetail stage mount for making fine alignments,
and a laser diode, all enclosed in a small, 3d printed case and integrated to act just like a fluorescence microscope.
Although other smartphone-turned-microscopes can image larger scale objects such as cells, Ozcan's group's latest mobile-phone optical attachment is the first to image and size the slim strand of a single DNA molecule.
The device is intended for use in remote laboratory settings to diagnose various types of cancers and nervous system disorders
as well as detect drug resistance in infectious diseases. To use the camera it is necessary to first isolate
and Windows smart application running on the same smart phone. The scanned information is sent then to a remote server in Ozcan's laboratory,
which measures the length of the DNA molecules. Assuming you have a reliable data connection,
the entire data processing takes less than 10 seconds. In their lab Ozcan's group tested the device's accuracy by imaging fluorescently labeled and stretched DNA segments.
The smartphone microscope demonstrated a significant drop in accuracy for 5, 000 base-pair or shorter segments,
which are problematic for conventional gel electrophoresis, a frequently used technique in biochemistry and molecular biology to size DNA and RNA fragments.
Ozcan's group next plans to test their device in the field to detect the presence of malaria-related drug resistance e
#Uncovering new functions of a gene implicated in cancer growth opens new therapeutic possibilities Two decades ago,
was also present in cancer patients and contributing to tumor progression. The present study reveals another way that Id1 works, hijacking a normal pathway in immune cell development and interfering with the entire immune system, starting in the bone marrow.
Without competent immune cells, the body can't fight off tumors, and instead, cancer is allowed to grow,
spread and thrive.""Targeting Id1 offers the potential to restore overall immune function, "said senior author Dr. David Lyden, the Stavros S. Niarchos Professor in Pediatric Cardiology and a professor of pediatrics in the Department of Pediatrics at Weill Cornell Medical College."
"When the immune system is functioning, treatment options are more plentiful. Given the increased incidence and death rates tied to advanced stage metastatic cancers,
there is also an increased urgency to understand how pro-metastatic, immunosuppressive mechanisms, like those driven by Id1,
work.""The investigators discovered that a tumor-secreted protein called transforming growth factor beta (TGF? promotes the activation of Id1.
The gene then sets off a chain reaction that redirects immune cells down a new pathway that churns out immature suppressor cells,
extinguishing the immune system's ability to mount an effective defense and allowing cancer to grow
and spread unabated.""Normally, the bone marrow produces, among other immune cell types, dendritic cells, which are capable of stopping the spread
and growth of tumors,"said first author Dr. Marianna Papaspyridonos, who was a Fulbright Cancer Research Fellow at Cornell University in Dr. Lyden's lab."But when TGF?
is released by the tumor and Id1 is upregulated, the normal generation of dendritic cells is interrupted,
and instead another subset of immune cells, which suppresses the immune system, is formed.""Those immune cells, called myeloid-derived suppressor cells,
allow cancer to more readily grow and spread. The researchers validated this finding in advanced melanoma patients,
who have increased TGF? plasma levels and higher levels of Id1 in myeloid peripheral blood cells. Targeting Id1 might provide a three-pronged therapeutic approach,
which would first reduce the metastatic potential of the tumor itself, then reduce the tumor's ability to form new blood vessels, a process called vasculogenesis,
and finally restore the patient's systemic immune function.""With this approach, immune cells will recognize a tumor as foreign and attack it,
"said Dr. Lyden, who also has appointments in the Sandra and Edward Meyer Cancer Center and the Gale and Ira Drukier Institute for Children's Health at Weill Cornell Medical College."
"This will improve vaccine development, lead to better treatment outcomes and ultimately benefit cancer patients
#Can photosynthesis be measured over large areas? Scientists find a way"Plant photosynthesis is a fundamental process that drives all ecosystem functions.
Despite established knowledge on how to measure and model photosynthesis on the leaf scale, measuring photosynthesis on the canopy scale has been challenging,
"says Jim Tang, associate scientist in the MBL Ecosystems Center. By analyzing the spectral signals captured by a special sensor they installed at Harvard Forest in Petersham, Mass."
"We found fluorescence data well correlated with photosynthesis that was measured by another independent method. This is the first time that satellite-based fluorescence is validated by ground measurements,
"Tang says.""This work has profound applications, as we can easily install this system into a drone, airplane,
or satellite to detect plant photosynthesis on a large scale to assess ecosystem health, "says lead author Xi Yang, a postdoctoral associate at Brown University."
"We may also apply this to agriculture for predicting crop yield, drought condition, or insect outbreak."
"Chlorophyll fluorescence is a byproduct of photosynthesis: under the sunlight, a small portion of solar energy(<1 percent) captured by chlorophyll is emitted as fluorescence.
However, recording the signal from that fluorescence is extremely difficult because it is obscured by the much higher intensity of solar radiation.
The group discovered a few wavelengths of light that allow measuring the specific fluorescence signal from photosynthesis. The team's fluorescence measurement system can record radiation at high resolution with a frequency of 5 minutes,
thus automating detection of photosynthesis from the canopy y
#Noroviruses spread several meters by air: Viruses responsible for 50 percent of gastroenteritis Noroviruses, a group of viruses responsible for over 50%of global gastroenteritis cases, can spread by air up to several meters from an infected person
according to a new study by Université Laval researchers. The discovery, details of which are presented in the latest issue of Clinical Infectious diseases,
suggests that measures applied in hospitals during gastroenteritis outbreaks may be insufficient to effectively contain this kind of infection.
The team led by Caroline Duchaine, professor at Université Laval's Faculty of science and Engineering and researcher at the Québec Heart and Lung Institute (IUCPQ) Research Centre
conducted the study at 8 hospitals and long-term care facilities affected by gastroenteritis outbreaks. Researchers gathered air samples at a distance of 1 meter from patients, at the doors to their rooms,
and at nursing stations. Noroviruses were found in the air at six of the eight facilities studied.
The viruses were detected in 54%of the rooms housing patients with gastroenteritis, 38%of the hallways leading to their rooms,
and 50%of nursing stations. Virus concentrations ranged from 13 to 2350 particles per cubic meter of air.
A dose of 20 norovirus particles is usually enough to cause gastroenteritis. According to Professor Duchaine
this previously unknown mode of norovirus propagation could explain why gastroenteritis outbreaks are so hard to contain:"
"The measures applied in hospital settings are designed only to limit direct contact with infected patients.
In light of our results, these rules need to be reviewed to take into account the possibility of airborne transmission of noroviruses.
Use of mobile air filtration units or the wearing of respiratory protection around patients with gastroenteritis are measures worth testing. i
#New mechanism controlling cell response to DNA damage discovered The protein SIRT1 plays an important role in controlling DNA damage.
However, if cells are exposed to oxidative stress, SIRT1 ubiquitination promotes cell death. These results are important
potentially leading to more effective therapeutic drugs in the future.""SIRT1 is known to be expressed abnormally in a variety of cancers
and might be a good target for therapy. Ubiquitin-proteasome inhibitors have already been used successfully in cancer therapy and clinical trials.
Therefore, this research might provide molecular bases and insights for developing additional therapeutic strategies in the future,"explained Ed Seto, Ph d.,senior member of the Cancer Biology and Evolution Program at Moffitt t
#Percentage of Texans without health insurance drops dramatically The report found that from September 2013 to March 2015, the percentage of uninsured adult Texans ages 18-64 dropped from 25 to 17 percent."
"This is a dramatic drop that's unprecedented in Texas, "said Elena Marks, president and CEO of the Episcopal Health Foundation and a health policy scholar at the Baker Institute."
"It's almost entirely attributable to newly insured individuals who purchased their own health insurance plans.
The drop in the uninsured rate occurred across all income levels and age groups, including younger adults."
"Despite this improvement, Texas remains the state with the highest percentage of people without health insurance,
and for the first time, Texas now has the largest number of uninsured residents in the country. The report found that the poorest Texans had the lowest drop in the uninsured rate.
"said Vivian Ho, the chair in health economics at Rice's Baker Institute, a professor of economics at Rice and a professor of medicine at Baylor College of Medicine."
since 2013 primarily because the ACA Marketplace allows households above the federal poverty level to buy health insurance using subsidies.
because state leaders chose not to accept federal funding for Medicaid expansion.""Unless Texas participates in an expanded Medicaid program
"Right now, those at the lowest incomes must rely on health care that is highly subsidized by county and state tax dollars,
or get by without needed health care.""The 31 percent decrease in the rate of uninsured Texans was similar to drops in other states that did not expand Medicaid coverage,
Today's report is a summary of data extracted from the HRMS Surveys in Texas administered between September 2013 and March 2015.
2015 in Molecular Cell, offer guidance for improving stem cell therapies. The new work also reveals more about certain cancers that arise
when these processes go astray, for example, when the Wnt signaling step becomes inappropriately reactivated, as happens in most colon cancers."
"says Kathy Jones, senior author of the paper and a Salk professor. These genes are among the first steps that prompt stem cells to begin to change,
and optimizing the efficiency of stem cell therapies.""When they looked closer at the genes that both pathways activated,
"Both the Wnt and Activin signaling processes operate differently in cancer, compared to stem cells.
The aberrant behavior of the Activin process, meanwhile, is tied to the metastasis of many cancers."
because these would have strong anticancer activity for many tumor types, "says Estar#s ."Because the environment of stem cells and cancer cells are quite distinct,
and different target genes are involved, it will be interesting to see how the synergy and regulation that we have defined in stem cells operates in the cells of a tumor. u
#UV radiations: NONO helps to mend the damage The study appeared as advanced online publication on Oncogene, a journal in cancer research from the Nature Publishing Group.
Here, the authors investigated the function of NONO, a multifunctional protein involved in melanoma development and progression, in the cellular response to UV radiations.
Normally, cells respond to radiation-induced DNA damage by activating different checkpoints which allow to stall cell cycle
or transmitted to daughter cells during mitosis. Luigi Alfano, Phd of the National Cancer Institute of Naples-Pascale Foundation-CROM-Cancer Research center of Mercogliano,
and do not efficiently activate the biochemical cascade of events that ultimately lead to DNA repair.
the authors found that NONO localizes at the sites of DNA damage where it favours the loading of other proteins which are key to this process."
"Considering that many studies are identifying NONO alterations in cancer, our findings will likely help to shed light on the molecular mechanisms of tumorigenesis, especially in tumour types like melanoma, in which exposure to UV radiations plays such a prominent part.
Our work also provides the preclinical framework supporting the development of new agents targeting NONO that could be used to sensitize cancer cells to a variety of drugs that cause DNA damage,
such as common chemotherapy agents,"states Francesca Pentimalli Phd from the National Cancer Institute of Naples co-corresponding of the study with Antonio Giordano,
Director of the Sbarro Institute for Cancer Research and Molecular Medicine, at Temple University, Philadelphia a
#Online voting a step closer thanks to breakthrough in security technology Taking inspiration from the security devices issued by some banks,
the security and privacy research group at Birmingham, led by Professor Mark Ryan, has developed a system that allows people to vote by employing independent hardware devices in conjunction with their PCS.
The new technique offers a fresh contribution to the debate surrounding e-voting and could be ready for use in time for the 2020 or 2025 General election.
Professor Ryan said:''This system works by employing a credit card-sized device similar to those used in online banking.
It is called Du-Vote, and we have been developing it over the past two years. From the voter's perspective, it's straightforward:
you receive a code on the device and type it back into the computer.''The main advantage of this system is that it splits the security between the independent security device and a voter's computer or mobile device.
A computer is a hugely powerful, all-purpose machine running billions of lines of code that no one really understands,
whereas the independent security device has a much, much smaller code base and is not susceptible to viruses.'Online voting carries a strong security requirement because of the possibility of undetectable interference in an election by foreign governments, criminal gangs,
or petty fraudsters. Malware affects an estimated 20%to 40%of PCS globally and specific election-targeting malware could be developed to attempt to alter votes cast
'This is currently the only piece of work that addresses a core problem of e-voting--namely, that someone may have viruses or other malware on their computer.
For example, the system in Estonia, where they have introduced already online voting, does not deal with this potentially undetectable source of vote manipulation or breach of voter privacy.'
But the system achieves even greater security than those used by banks by allowing for the possibility that the security devices themselves have been manufactured under the influence of a hostile adversary.
even if a hostile adversary controls the entire computing infrastructure, voters and election officials can still detect electoral fraud.
Remote Electronic Voting with Untrusted Computers',will be presented at the 28th IEEE Computer security Foundations Symposium in Verona, Italy, in July y
#New test predicts sudden cardiac death in hemodialysis patients ICNC is organised by the Nuclear Cardiology
and Cardiac CT section of the European Association of Cardiovascular Imaging (EACVI), a registered branch of the European Society of Cardiology (ESC), the American Society of Nuclear Cardiology (ASNC),
and the European Association of Nuclear medicine (EANM). ICNC 12 is held 3 to 5 may 2015 in Madrid, Spain.
because they often have latent ischaemic heart disease which reduces blood flow to the heart. Latent means they don't have any clinical signs
or symptoms, making it very difficult to predict a future heart attack.""He continued:""Ischaemic heart disease should be diagnosed at an early stage
so that preventive therapies can be given. But exercise stress testing is inappropriate for diagnosis in hemodialysis patients who have multiple complications including muscle weakness, osteoporosis and peripheral arterial disease."
"The current study investigated the ability of 3 methods, alone or in combination, to predict the risk of sudden cardiac death in hemodialysis patients.
All 3 methods were performed at rest. The first was a nuclear medicine radioisotope technique called beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy1
which measures fatty acid uptake by the heart. ECG2 was used to assess the Q wave and C-reactive protein3 levels in the blood were measured.
The study included 677 patients from the multicentre, prospective cohort study B-SAFE. 4 BMIPP scintigraphy, ECG and C reactive-protein protein assessment was performed in all patients.
Patients who suffered sudden cardiac death were more likely to have abnormal BMIPP scintigraphy, abnormal Q wave
which could be caused by latent ischaemic heart disease and may lead to fatal cardiac events.""He added:"
"An abnormal Q wave indicates the presence of previous myocardial infarction or serious myocardial injury responsible for low cardiac output, heart failure and/or potentially fatal arrhythmias.
High C reactive-protein protein levels reflect any active inflammatory reactions such as infection or atherosclerosis.""Dr Hashimoto continued:"
In a clinical setting, BMIPP scintigraphy can be used in hemodialysis patients who are identified as high risk by abnormal Q wave and increased C reactive-protein protein.
Abnormal BMIPP identifies specific myocardial injury which could be an effective therapeutic target for preventing sudden cardiac death."
"He concluded:""Further diagnostic tests should be considered in high risk patients with abnormal BMIPP scintigraphy.
Cardiac function assessment for heart failure, coronary angiography for ischaemic heart disease and Holter ECG monitoring for lethal arrhythmias can identify the type of myocardial injury
and help physicians select a prophylactic therapeutic strategy against sudden cardiac death in hemodialysis patients."
"Notes1. Scintigraphy is a diagnostic test in nuclear medicine. Radioisotopes are injected and the radiation emitted is used to create 2d images.
Beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) is a radioisotope whose uptake is an indicator of fatty acid metabolism in the heart. 2. An electrocardiogram (ECG) records the electrical activity of the heart.
An abnormal Q wave on an ECG is a sign of a previous myocardial infarction. It detects scar tissue formed after the heart muscle is damaged by a heart attack. 3. C reactive-protein protein is a nonspecific test used to detect inflammation in the body.
Levels of C reactive-protein protein are higher in the blood when there is inflammation. 4. The full title of the B-SAFE study is BMIPP SPECT Analysis for Decreasing Cardiac Events in Hemodialysis Patients s
#Chemists cook up three atom-thick electronic sheets This process of film deposition is common for traditional semiconductors like silicon
or gallium arsenide--the basis of modern electronics--but Cornell scientists are pushing the limits for how thin they can go.
They have demonstrated a way to create a new kind of semiconductor thin film that retains its electrical properties even
when it is just atoms thick. Three atom-thick layers of molybdenum disulfide were cooked up in the lab of Jiwoong Park, associate professor of chemistry and chemical biology and member of the Kavli Institute at Cornell for Nanoscale Science.
The films were designed and grown by postdoctoral associate Kibum Kang and graduate student Saien Xie. Their work is published online in Nature, April 30."
"The electrical performance of our materials was comparable to that of reported results from single crystals of molybdenum disulfide,
but instead of a tiny crystal, here we have a 4-inch wafer, "Park said. Molybdenum disulfide,
which is garnering worldwide interest for its excellent electrical properties, has previously been grown only in disjointed,
"archipelago"-like single crystal formations, Park said. But making smooth, flat, ultrathin sheets, like paper, is the ultimate goal,
and the bridge to actual devices. The researchers pulled off the feat by tuning the growth conditions of their films using a technique called metal organic chemical vapor deposition (MOCVD.
tweaking conditions and temperatures not unlike experimenting in the kitchen. They found that their crystals grew perfectly stitched together,
but only with a little bit of hydrogen and in completely dry conditions, for example. In addition to advanced optical imaging techniques, researchers led by co-author David Muller,
professor of applied and engineering physics and director of Cornell's Kavli Institute, contributed advanced transmission electron microscopy to test
This effectively proved that these three-atom-thick semiconducting films can be made into multilevel electronic devices of unsurpassed thinness.
and optoelectronic devices can be derived.""These were only the first two materials, but we want to make a whole palette of materials,
"The work was supported by the Air force Office of Scientific research, the National Research Foundation of Korea and the Cornell Center for Materials Research funded by the National Science Foundation,
as well as the Samsung Advanced Institute for Technology. Devices were fabricated at the Cornell Nanoscale Science and Technology Facility,
also supported by NSF F
#New test predicts sudden cardiac death in hemodialysis patients ICNC is organised by the Nuclear Cardiology
and Cardiac CT section of the European Association of Cardiovascular Imaging (EACVI), a registered branch of the European Society of Cardiology (ESC), the American Society of Nuclear Cardiology (ASNC),
and the European Association of Nuclear medicine (EANM). ICNC 12 is held 3 to 5 may 2015 in Madrid, Spain.
Dr Hashimoto said:""Hemodialysis patients are increased at risk of sudden cardiac death because they often have latent ischaemic heart disease
which reduces blood flow to the heart. Latent means they don't have any clinical signs
or symptoms, making it very difficult to predict a future heart attack.""He continued:""Ischaemic heart disease should be diagnosed at an early stage
so that preventive therapies can be given. But exercise stress testing is inappropriate for diagnosis in hemodialysis patients who have multiple complications including muscle weakness, osteoporosis and peripheral arterial disease."
"The current study investigated the ability of 3 methods, alone or in combination, to predict the risk of sudden cardiac death in hemodialysis patients.
All 3 methods were performed at rest. The first was a nuclear medicine radioisotope technique called beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy1
which measures fatty acid uptake by the heart. ECG2 was used to assess the Q wave and C-reactive protein3 levels in the blood were measured.
The study included 677 patients from the multicentre, prospective cohort study B-SAFE. 4 BMIPP scintigraphy, ECG and C reactive-protein protein assessment was performed in all patients.
Patients who suffered sudden cardiac death were more likely to have abnormal BMIPP scintigraphy, abnormal Q wave
which could be caused by latent ischaemic heart disease and may lead to fatal cardiac events.""He added:"
"An abnormal Q wave indicates the presence of previous myocardial infarction or serious myocardial injury responsible for low cardiac output, heart failure and/or potentially fatal arrhythmias.
High C reactive-protein protein levels reflect any active inflammatory reactions such as infection or atherosclerosis.""Dr Hashimoto continued:"
In a clinical setting, BMIPP scintigraphy can be used in hemodialysis patients who are identified as high risk by abnormal Q wave and increased C reactive-protein protein.
Abnormal BMIPP identifies specific myocardial injury which could be an effective therapeutic target for preventing sudden cardiac death."
"He concluded:""Further diagnostic tests should be considered in high risk patients with abnormal BMIPP scintigraphy.
Cardiac function assessment for heart failure, coronary angiography for ischaemic heart disease and Holter ECG monitoring for lethal arrhythmias can identify the type of myocardial injury
and help physicians select a prophylactic therapeutic strategy against sudden cardiac death in hemodialysis patients
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