Tag Archives: mechanism

Moths Wired Two Ways to Take Advantage of Floral Potluck

By Guest PostDecember 9, 2012Naturearizona, behavior, brain, brain activity, bright green, buffet, caterpillar, channels, chemical composition, favored blossoms, floral environment, flower, hong lei, humans, insects, jeffrey riffell, john hildebrand, leif abrell, manduca sexta, mechanism, moth, naive moths, neural pathways, neurobiology, north, olfactory information, oxygenated aromatic compounds, pollinator, process, scent samples, science express, scientist, sources of nectar, south america, soybean, tobacco hornworms, university, Washington

Moths are able to enjoy a pollinator’s buffet of flowers – in spite of being among the insect world’s picky eaters – because of two distinct “channels” in their brains, scientists at the University of Washington and University of Arizona have discovered.

One olfactory channel governs innate preferences of the palm-sized hawk moths that were studied – insects capable of traveling miles in a single night in search of favored blossoms. The other allows them to learn about alternate sources of nectar when their first choices are not available.

For moths, the ability to seek and remember alternate sources of food helps them survive harsh, food-deprived conditions. Scientists knew bees could learn, but this is the first proof that moths can too. (more…)

New Insights into How Genetic Differences among Individuals Influence Breast Cancer Risk from Low-Dose Radiation

By Guest PostOctober 17, 2012Health, Scienceandy wyrobek, antoine snijders, berkeley lab, breast cancer, cancer risk, cellular, cellular proliferation, chemical therapy, ct scan, department, dna repair, energy, gene, genetic makeup, gland cancer, immune response, ionizing radiation, joe gray, low dose, mammary tissue, mechanism, mice, non radiation, radiotherapy, resistance, risk, scientist, strain, survival outcome, therapy, tissue mechanism, tissue stress, woman

Berkeley Lab research could lead to new ways to ID women who have higher risk of breast cancer from low-dose radiation

Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have identified tissue mechanisms that may influence a woman’s susceptibility or resistance to breast cancer after exposure to low-dose ionizing radiation, such as the levels used in full-body CT scans and radiotherapy.

The research could lead to new ways to identify women who have higher or lower risks of breast cancer from low-dose radiation. Such a predictive tool could help guide the treatment of cancer patients who may be better served by non-radiation therapies. (more…)

Plants Unpack Winter Coats When Days Get Shorter

By Guest PostAugust 29, 2012Sciencecbf, cold response pathway, crepeat binding, crop productivity, factor, freezing, freezing temperature, frost protection, gene, mechanism, michael thomashow, plant, potential tool, sunlight

EAST LANSING, Mich. — Mechanisms that protect plants from freezing are placed in storage during the summer and wisely unpacked when days get shorter.

In the current issue of the Proceedings of the National Academy of Sciences, Michael Thomashow, University Distinguished Professor of molecular genetics, demonstrates how the CBF (C-repeat binding factor) cold response pathway is inactive during warmer months when days are long, and how it’s triggered by waning sunlight to prepare plants for freezing temperatures. (more…)

Better Monitoring of Food Quantity Makes Self-Control Easier

By Guest PostAugust 27, 2012Healthamerica, carlson school, consumption, eat less, food quantity, joseph redden, kelly haws, mechanism, minneapolis, monitoring, obesity problem, satiation, self control, st paul, twin cities, university of minnesota

UMN study shows eating less is about reduced desire as well as willpower

MINNEAPOLIS / ST. PAUL — New research from the University of Minnesota’s Carlson School of Management suggests learning how to stop enjoying unhealthy food sooner may play a pivotal role in combating America’s obesity problem. The research, published in the Journal of Consumer Research, explores how satiation, defined as the drop in liking during repeated consumption, can be a positive mechanism when it lowers the desire for unhealthy foods.

“When people talk about self-control, they really imply that self-control is willpower and that some people have it and others don’t when facing a tempting treat,” says Joseph Redden, an assistant professor of marketing at the Carlson School and lead author of the ‘Healthy Satiation: The Role of Decreasing Desire in Effective Self-Control.’ “In reality, nearly everyone likes these treats. Some people just stop enjoying them faster and for them it’s easier to say no.” (more…)

Pollination with Precision: How Flowers Do It

By Guest PostMay 23, 2012Naturearabidopsis plants, brown university, chaotic frenzy, female gametes, fertilization, gamete fusion, hap2, kristin beale, logistical efficiency, mark johnson, mechanism, microscope, model, mothers day, mutant sperm, ovule, pollen grains, pollen tubes, pollination, polytubey, precision, reproduction, sex cells, sperm

Pollination could be a chaotic disaster. With hundreds of pollen grains growing long tubes to ovules to deliver their sperm to female gametes, how can a flower ensure that exactly two fertile sperm reach every ovule? In a new study, Brown University biologists report the discovery of how plants optimize the distribution of pollen for successful reproduction.

PROVIDENCE, R.I. [Brown University] — Next Mother’s Day, say it with an evolved model of logistical efficiency — a flower. A new discovery about how nature’s icons of romance manage the distribution of sperm among female gametes with industrial precision helps explain why the delicate beauties have reproduced prolifically enough to dominate the earth.

In pollination, hundreds of sperm-carrying pollen grains stick to the stigma suspended in the middle of a flower and quickly grow a tube down a long shaft called a style toward clusters of ovules, which hold two female sex cells. This could be a chaotic frenzy, but for the plant to succeed, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don’t work. (more…)

Pigeons’ Homing Skill Not Down to Iron-Rich Beak Cells

By Guest PostApril 16, 2012Natureballs of iron, beaks, david keays, electrical signal, Environment, imaging technique, infection, iron, macrophages, magnetic cell, magnetic field, magnetic nerve cell, mark lythgoe, mechanism, migratory bird, navigation, nerve cell, pigeon, red blood cell, state-of-the-art, theory, university college london, vienna, white blood cell

The theory that pigeons’ famous skill at navigation is down to iron-rich nerve cells in their beaks has been disproved by a new study published in Nature.

The study shows that iron-rich cells in the pigeon beak are in fact specialised white blood cells, called macrophages. This finding, which shatters the established dogma, puts the field back on course as the search for magnetic cells continues. (more…)

Researchers Uncover How New Melanoma Drug Accelerates Secondary Skin Cancers

By Guest PostJanuary 20, 2012Healthantoni ribas, braf mutation, cancer growth, cancer mutation, cancer treatment, drug, hematology, malignant cells, mechanism, mek inhibitor, melanoma cells, metastatic melanoma, mutated braf protein, mutation, oncogenic mutations, oncology, patients, plexxikon, ras mutation, roche, ruby family foundation, seaver institute, secondary skin cancers, side effect, skin squamous cell carcinomas, vemurafenib, zelboraf

Patients with metastatic melanoma taking the recently approved drug vemurafenib (marketed as Zelboraf) responded well to the twice-daily pill, but some of them developed a different, secondary skin cancer.

Now, researchers at UCLA’s Jonsson Comprehensive Cancer Center, working with investigators from the Institute of Cancer Research in London, Roche and Plexxikon, have elucidated the mechanism by which the drug excels at fighting melanoma but also allows for the development of skin squamous-cell carcinomas. (more…)

Change in Temperature Uncovers Genetic Cross Talk in Plant Immunity

By Guest PostNovember 17, 2010Nature, Sciencearabidopsis thaliana, avrrps4, bacterial infection, bacterial invaders, bacterial pathogen, cell, cross talk, disease, effector proteins, immune system, mechanism, pathogen, plant proteins, plants, proteins, pseudomonas syringae, resistance proteins, saikat bhattacharjee, sang hee kim, srfr1, walter gassmann

*University of Missouri investigators’ discovery sheds light on how plants fight off bacterial infections*

Columbia, MO — Like us, plants rely on an immune system to fight off disease. Proteins that scout out malicious bacterial invaders in the cell and communicate their presence to the nucleus are important weapons in the plant’s disease resistance strategy. Researchers at the University of Missouri recently “tapped” into two proteins’ communications with the nucleus and discovered a previously unknown level of cross talk. The discovery adds important new information about how plant proteins mediate resistance to bacteria that cause disease and may ultimately lead to novel strategies for boosting a plant’s immune system.

Special proteins in the plant, called resistance proteins, can recognize highly specific features of proteins from pathogen, called effector proteins. When a pathogen is detected, a resistance protein triggers an “alarm” that communicates the danger to the cell’s nucleus. The communication between the resistance protein and nucleus occurs through a mechanism called a signaling pathway. (more…)