Τρίτη, 27 Μαΐου 2014

ScienceDaily: Top News

ScienceDaily: Top News


How DNA is 'edited' to correct genetic diseases

Posted: 26 May 2014 03:27 PM PDT

A major step forward in our understanding of how enzymes 'edit' genes has been made by an international team of researchers, paving the way for correcting genetic diseases in patients. Researchers have observed the process by which a class of enzymes called CRISPR -- pronounced 'crisper' -- bind and alter the structure of DNA. The results provide a vital piece of the puzzle if these genome editing tools are ultimately going to be used to correct genetic diseases in humans.

From chaos to order: How ants optimize food search

Posted: 26 May 2014 03:27 PM PDT

Ants are capable of complex problem-solving strategies that could be widely applied as optimization techniques. An individual ant searching for food walks in random ways. Yet the collective foraging behavior of ants goes well beyond that, a mathematical study reveals: The animal movements at a certain point change from chaos to order. This happens in a self-organized way. Understanding the ants could help analyze similar phenomena -- for instance how humans roam the Internet.

Relaxation helps pack DNA into a virus

Posted: 26 May 2014 03:27 PM PDT

DNA packs more easily into the tight confines of a virus when given a chance to relax. DNA is a long, unwieldy molecule that tends to repel itself because it is negatively charged, yet it can spool tightly. Within the heads of viruses, DNA can be packed to near crystalline densities, crammed in by a molecular motor.

Ebola vaccine success highlights dilemma of testing on captive chimps to save wild apes

Posted: 26 May 2014 03:26 PM PDT

A new study illustrates "high conservation potential" of vaccines for endangered wild primates devastated by viral disease, but highlights need for access to captive chimpanzees so vaccines can be trialled before being administered in the wild.

How biodiversity arises: Single gene mutation during development can lead to differences in jaw shape, feeding strategies

Posted: 26 May 2014 03:26 PM PDT

A new study of how biodiversity arises shows how a mutation in a single gene in development can lead to different consequences not only in jaw shape, but how this leads to different feeding strategies. It is among the first to show how one genetic change influences trait development and function.

Melatonin makes old bones stronger, research shows

Posted: 26 May 2014 10:06 AM PDT

Melatonin supplements may make bones stronger in old rats, research shows. This suggests a possible avenue for the prevention of osteoporosis. Bones are built up by certain cells known as osteoblasts during the daytime and broken down by others (osteoclasts) at night. As we age, we sleep less, and so the cells that break down the bones are more active. By giving old rats melatonin supplements to regulate their circadian rhythms, the researchers have been able to make their bones denser, less brittle and more flexible.

Neurons can use local stores for communication needs

Posted: 26 May 2014 07:18 AM PDT

Neurons can utilize a supremely localized internal store of calcium to initiate the secretion of neuropeptides, one class of signaling molecules through which neurons communicate with each other and with other cells, researchers have shown. Neuropeptides are released from neurons through a process that—like other secretory events—is triggered primarily by the influx of calcium into the neuron through voltage-gated channels.

Robot warriors pose ethical dilemma

Posted: 26 May 2014 07:18 AM PDT

With the increasing use of drones in military operations, it is perhaps only a matter of time before robots replace soldiers. Whether fully automated war is on the immediate horizon, one researcher says it's not too early to start examining the ethical issues that robot armies raise.

Immune system precursor cells that fight infection discovered

Posted: 26 May 2014 07:18 AM PDT

The innate immune system recognizes infectious agents such as viruses and bacteria. A group of lymphocytes known as "innate lymphoid cells" or ILCs plays a central role in the defense of the human body against infective agents, researchers have found. They have discovered previously unidentified ILCs that are able to protect epithelial surfaces, such as those of the intestinal mucosa, against infection. The results provide important additional insights into how the immune system functions.

Insights into genetics of cleft lip

Posted: 26 May 2014 07:17 AM PDT

A specific stretch of DNA controls far-off genes to influence the formation of the face, researchers have found. The new study, outlining how this is done, helps understand the genetic causes of cleft lip and cleft palate, which are among the most common congenital malformations in humans.

Molecules do the triple twist

Posted: 26 May 2014 07:16 AM PDT

Scientists have managed to make a triple-Möbius annulene, the most twisted fully conjugated molecule to date. An everyday analogue of a single twisted Möbius molecule is a Möbius strip. It can be made easily by twisting one end of a paper strip by 180 degrees and then joining the two ends.

Immunotherapy for prostate cancer in sight

Posted: 26 May 2014 07:16 AM PDT

Patients with advanced prostate cancer have now been given some hope from a new study. In just a few years' time, Ipilumumab could be approved as a treatment for the world's third-most common type of cancer, researchers predict. Worldwide, prostate cancer is the third-most common form of cancer and is globally the sixth-most common cause of death from cancer among men.

New perspectives to the design of molecular cages

Posted: 26 May 2014 07:16 AM PDT

Researchers report a new method of building molecular cages. The method involves the exploitation of intermolecular steric effects to control the outcome of a self-assembly reaction. Molecular cages are composed of organic molecules (ligands) which are bound to metal ions during a self-assembly process. Depending on the prevailing conditions, self-assembly processes urge to maximize the symmetry of the system and thus occupy every required metal binding site. The research group developed a method in which sterically hindered ligands are used to seemingly disrupt the self-assembly process. This new strategy allows a ligand to occupy only two of the four potential binding sites of the metal.

Fighting cancer with dietary changes

Posted: 26 May 2014 07:15 AM PDT

Calorie restriction during treatment for breast cancer changes cellular programming in a way that lowers the chance of metastases in mice. Breast cancer patients are often treated with hormonal therapy to block tumor growth, and steroids to counteract the side effects of chemotherapy. However, both treatments can cause a patient to have altered metabolism which can lead to weight gain. In fact, women gain an average of 10 pounds in their first year of treatment. Recent studies have shown that too much weight makes standard treatments for breast cancer less effective, and those who gain weight during treatment have worse cancer outcomes.

Outdoor lighting using wind-solar hybrid renewable energy sources

Posted: 25 May 2014 05:47 PM PDT

As an outcome from the continuous hybrid renewable energy research, an innovative outdoor lighting system powered by a shroud-augmented wind turbine and a solar panel was installed in the Kuala Lumpur campus of University of Malaya (UM).

Promising approach to slow brain degeneration in Huntington's disease uncovered

Posted: 25 May 2014 05:44 PM PDT

Blocking a specific class of glutamate receptors can improve motor learning and coordination, and prevent cell death in animal models of Huntington's disease, research shows. As Huntington's disease is an inherited condition that can be detected decades before any clinical symptoms are seen in humans, this research could lead to preventive treatments that will delay the onset of symptoms and neurodegeneration.

Sound and vision: Visual cortex processes auditory information, too

Posted: 25 May 2014 12:53 PM PDT

"Seeing is believing," so the idiom goes, but new research suggests vision also involves a bit of hearing too. "So, for example, if you are in a street and you hear the sound of an approaching motorbike, you expect to see a motorbike coming around the corner. If it turned out to be a horse, you'd be very surprised," researchers said.

DNA nanotechnology places enzyme catalysis within an arm's length

Posted: 25 May 2014 12:53 PM PDT

Using molecules of DNA like an architectural scaffold, scientists have developed a 3-D artificial enzyme cascade that mimics an important biochemical pathway that could prove important for future biomedical and energy applications. In the latest breakthrough, the research team took up the challenge of mimicking enzymes outside the friendly confines of the cell. These enzymes speed up chemical reactions, used in our bodies for the digestion of food into sugars and energy during human metabolism, for example.

New molecule for high-resolution cell imaging

Posted: 25 May 2014 12:53 PM PDT

Cells have their own tiny skeletons that are responsible for many important cellular functions. Scientists have developed novel fluorescent probes for imaging these important structures easily and with unprecedented resolution. The scientists believe that they can extend their work into other types of proteins and tissues. "Up to now, no probes were available that would allow you to get high quality images of microtubules and microfilaments in living cells without some kind of genetic modification," one researcher notes. "With this work, we provide the biological community with two high-performing, high-contrast fluorogenic probes that emit in the non-phototoxic part of the light spectrum, and can be even used in tissues like whole-blood samples."

Remapping the epic evolution of a 'ring species' through central Asia

Posted: 25 May 2014 12:47 PM PDT

The Greenish Warbler, long considered an idealized example of a single species that diverged into two as it expanded its range, has a much more checkered family history than biologists previously realized. Ring species are a continuous loop of related populations, each adapted to its local environment, with two terminal populations in the loop meeting but now unable to mate. But an in-depth genomic analysis reveals that the Greenish Warbler's genetic migration through central Asia involved periods of geographic separation and hybridization.

Cancer immunotherapy: Potential new target found

Posted: 25 May 2014 12:47 PM PDT

Myeloid-derived suppressor cells (MDSCs), are found abundantly in the microenvironment around tumors. They interfere with immune response, promoting cancer progression. Now scientists have found a way to target elusive cells that suppress immune response, depleting them with peptides that spare other important cells and shrink tumors in preclinical experiments.

Buried fossil soils found to be awash in carbon

Posted: 25 May 2014 12:47 PM PDT

Soils that formed on Earth's surface thousands of years ago and that are now deeply buried features of vanished landscapes have been found to be rich in carbon, adding a new dimension to our planet's carbon cycle. The finding is significant as it suggests that deep soils can contain long-buried stocks of organic carbon which could, through erosion, agriculture, deforestation, mining and other human activities, contribute to global climate change.

How signals trigger cancer cells to spread

Posted: 25 May 2014 12:47 PM PDT

A signaling pathway in cancer cells that controls their ability to invade nearby tissues in a finely orchestrated manner has been discovered by researchers. The findings offer insights into the early molecular events involved in metastasis, the deadly spread of cancer cells from primary tumor to other parts of the body.

Gene mutation found for aggressive form of pancreatic cancer

Posted: 25 May 2014 12:47 PM PDT

A mutated gene common to adenosquamous carcinoma (ASC) tumors has been discovered by researchers -– the first known unique molecular signature for this rare, but particularly virulent, form of pancreatic cancer. Pancreatic cancer is the fourth leading cause of cancer-related death in the United States, with roughly 45,220 new cases diagnosed and more than 38,400 deaths annually. Both numbers are rising. ASC cases are infrequent, but typically have a worse prognosis than more common types of pancreatic cancer.

Mice with 'mohawks' help scientists link autism to two biological pathways in brain

Posted: 25 May 2014 12:47 PM PDT

"Aha" moments are rare in medical research, scientists say. As rare, they add, as finding mice with Mohawk-like hairstyles. But both events happened in a lab, months after an international team of neuroscientists bred hundreds of mice with a suspect genetic mutation tied to autism spectrum disorders.

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