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Archive - Aug 16, 2014

Science Disputes Magpie Folklore

Magpies are not attracted to shiny objects and do not routinely steal small trinkets such as jewelry, according to a new study. In European culture, it is widely accepted that magpies (Pica pica) are the pilferers of the bird kingdom, unconditionally attracted to sparkly things and prone to pinching them for their nests, almost as a compulsion. But psychologists at the Centre for Research in Animal Behaviour (CRAB) at the University of Exeter are now countering this folklore, having shown that the species is actually frightened of new and unfamiliar objects, rather than attracted to them. The researchers carried out a series of experiments with both a group of magpies that had come from a rescue center, and wild magpies from the grounds of the University. Under carefully monitored conditions, the birds were exposed to both shiny and non-shiny items, and their reactions recorded. Dr. Toni Shephard, lead author of the study, said: "We did not find evidence of an unconditional attraction to shiny objects in magpies. Instead, all objects prompted responses indicating neophobia – fear of new things – in the birds. We suggest that humans notice when magpies occasionally pick up shiny objects because they believe the birds find them attractive, while it goes unnoticed when magpies interact with less eye-catching items. It seems likely, therefore, that the folklore surrounding them is a result of cultural generalization and anecdotes rather than evidence." The field experiment was conducted at eight sites on the University of Exeter campus where magpies are accustomed to regular human activity, allowing observations to be conducted in close proximity. The test objects were shiny metal screws, small foil rings, and a small rectangular piece of aluminum foil.

Beetle’s Scales Are Whitest, Most Efficient Light-Scattering Biological Material Known, Could Prove Basis for Brighter, Whiter Coatings and Materials

The physical properties of the ultra-white scales on certain species of beetle could be used to make whiter paper, plastics, and paints, while using far less material than is used in current manufacturing methods. The Cyphochilus beetle (image), which is native to South-East Asia, is whiter than paper, thanks to ultra-thin scales which cover its body. A new investigation of the optical properties of these scales has shown that they are able to scatter light more efficiently than any other biological tissue known, which is how they are able to achieve such a bright whiteness. The findings were published online on August 15, 2014 in an open-access article in Scientific Reports. Animals produce colors for several purposes, from camouflage to communication, to mating and thermoregulation. Bright colors are usually produced using pigments, which absorb certain wavelengths of light and reflect others, which our eyes then perceive as color. To appear as white, however, a tissue needs to reflect all wavelengths of light with the same efficiency. The ultra-white Cyphochilus and L. Stigmabeetles produce this coloration by exploiting the geometry of a dense complex network of chitin – a molecule similar in structure to cellulose, which is found throughout nature, including in the shells of molluscs, the exoskeletons of insects, and the cell walls of fungi. The chitin filaments are just a few billionths of a meter thick, and on their own are not particularly good at reflecting light. The current research, a collaboration between the University of Cambridge and the European Laboratory for Non-Linear Spectroscopy in Italy, has shown that the beetles have optimized their internal structure in order to produce maximum white with minimum material, like a painter who needs to whiten a wall with a very small quantity of paint.

Gut Bacteria May Rule Human Eating Behavior and Dietary Choices

It sounds like science fiction, but it seems that bacteria within us — which outnumber our own cells by approximately 100-fold — may very well be affecting both our cravings and our moods to get us to eat what they want, and often are driving us toward obesity. In an article published online on August 7, 2014 in the journal BioEssays, researchers from the University of California-San Francisco, (UCSF), Arizona State University, and the University of New Mexico concluded from a review of the recent scientific literature that microbes influence human eating behavior and dietary choices to favor consumption of the particular nutrients the microbes grow best on, rather than simply passively living off whatever nutrients humans choose to send their way. Bacterial species vary in the nutrients they need. Some prefer fat, and others sugar, for instance. But they not only vie with each other for food and to retain a niche within their ecosystem — our digestive tracts — they also often have different aims than we do when it comes to our own actions, according to senior author Athena Aktipis, Ph.D., co-founder of the Center for Evolution and Cancer with the Helen Diller Family Comprehensive Cancer Center at UCSF. While it is unclear exactly how this occurs, the authors believe this diverse community of microbes, collectively known as the gut microbiome, may influence our decisions by releasing signaling molecules into our gut. Because the gut is linked to the immune system, the endocrine system, and the nervous system, those signals could influence our physiologic and behavioral responses. "Bacteria within the gut are manipulative," said Carlo Maley, Ph.D., director of the UCSF Center for Evolution and Cancer and the corresponding author on the BioEssays paper.

Prestigious Journal Features Major Article on Preterm Labor

The August 15, 2014 issue of the prestigious journal Science features a major article about the most important problem in obstetrics: preterm labor. The article, "Preterm Labor: One Syndrome, Many Causes," delivers a powerful message: preterm birth is not one condition, but many, and provides a framework for meeting this challenge. "There are 15 million preterm babies born annually, and the condition affects 5 percent to 15 percent of all pregnancies, with the highest rates in North America and Africa. Prematurity is the leading cause of infant death up to age 1and the second-leading cause of childhood death before the age of 5," said Roberto Romero, M.D., D.Med.Sci., chief of the Perinatology Research Branch (PRB) of the Eunice Kennedy Shriver National Institute of Child Health and Human Development located at Wayne State University (WSU) and the Detroit Medical Center (DMC). "We have made progress by identifying the causes of premature labor, and now we propose that it is possible to reframe the problem and make it tractable." A common belief is that preterm labor is merely labor that starts too soon. This perception derives from the fact that labor, whether term or preterm, has the same features – increased uterine contractility, opening of the cervix, and rupture of the membranes. "However," Dr. Romero said, "the fundamental difference is that normal labor at term occurs when the uterus and placenta cannot continue to support the growth of the fetus within the womb. In contrast, preterm labor results from several disease states." Dr. Romero considers premature labor a syndrome – a collection of syndromes and signs – caused by multiple disease processes. A typical example of these disease processes is a "silent" intra-amniotic infection.

Depression Associated with Parkinson’s Disease and Undertreated

Depression is known to be a common symptom of Parkinson’s disease, but remains untreated for many patients, according to a new study by Northwestern Medicine investigators in collaboration with the National Parkinson’s Foundation (NPF). In fact, depression is the most prevalent non-motor symptom of Parkinson’s, a chronic neurodegenerative disorder typically associated with movement dysfunction. This fact is especially relevant now in light of the recent suicide of American comedian Robin Williams (image), who was reported to have been recently diagnosed with the early stages of Parkinson’s disease, while at the same time suffering from depression and anxiety. “We confirmed suspicion that depression is a very common symptom in Parkinson’s disease. Nearly a quarter of the people in the study reported symptoms consistent with depression,” said Danny Bega, M.D., 2014 graduate medical education (GME), instructor in the Ken and Ruth Davee Department of Neurology and first author of the study. “This is important because previous research has determined that depression is a major determinant of overall quality of life.” Using the neuropsychiatric symptoms’ (NPS’s) patient database, the investigators looked at records of more than 7,000 people with Parkinson’s disease. Among those with high levels of depressive symptoms, only one-third had been prescribed antidepressants before the study began, and even fewer saw social workers or mental health professionals for counseling. The investigators then focused their analysis on the remaining two-thirds of patients with depressive symptoms who were not receiving treatment at the start of the study. Throughout a year of observation, fewer than 10 percent of them received prescriptions for antidepressants or referrals to counseling.

Study Suggests Broad Utility of Sequence-Related Amplified Polymorphism (SRAP) Markers

Today, many ecological and evolutionary studies depend on a wide range of molecular tools to infer phylogenetic relationships, uncover population structure within species, and track quantitative traits. Agricultural studies use these same tools to improve crop yield and increase resistance to pests and disease. However, many of these methods—such as amplified fragment length polymorphisms (AFLP), inter-simple sequence repeats (ISSR), and random amplified polymorphic DNA (RAPD)—have technical limitations. These include issues of reproducibility, ambiguity in determining homology, and significant demands on both cost and time for researchers. Sequence-related amplified polymorphism (SRAP) markers show promise as an alternative to traditional markers as they have proven to be highly variable and less technically demanding to obtain and use. This recently developed dominant marker technique produces genome-wide fragments and has been used primarily in studies aimed at crop development. Previous studies have utilized this method to identify pathogen-resistant markers and better understand the genetic basis of fruit and flower form and structure, as well as flowering and fruiting times. In a new, open-access publication in the July 2014 issue of Applications in Plant Sciences, researchers at Ohio State University have made a case for the use of these markers across a broad range of research fields including plant systematics, biogeography, conservation, and ecology. "These markers exhibit variation useful for uncovering genetic structure at a variety of taxonomic levels, constructing linkage maps, and have proven valuable for the improvement of agronomic crops," explains Dr. Daniel Robarts, lead author of the study. Dr.