Tag Archives: life cycle

Aging erodes genetic control, but it’s flexible

By Guest PostDecember 8, 2013Scienceage, aging, brown university, enzyme called sir2, erode, ethan tobias, flow of chromatin, fruit flies, genetic control, guyu du, heterochromatin, jason wood, journal aging, life cycle, nan jiang, nicola neretti, pev, phenomenon, position effect variegation, protein sir2, rachel whitaker, stephen helfand, strands of dna, tissue

In yeast at least, the aging process appears to reduce an organism’s ability to silence certain genes that need to be silenced. Now researchers at Brown University who study the biology of aging have shown that the loss of genetic control occurs in fruit flies as well. Results appear online in the journal Aging.

PROVIDENCE, R.I. [Brown University] — Biologists at Brown University have found a way to measure the effects of aging by watching the ebb and flow of chromatin, a structure along strands of DNA that either silences or permits gene expression. In several newly published experiments they show that gene silencing via chromatin in fruit flies declines with age. (more…)

Cocaine use can make otherwise resistant immune cells susceptible to HIV

By Guest PostOctober 5, 2013Healthaids epidemic, cd4 t cells, chronic user, cocaine, dhaval dixit, dimitrios vatakis, drug, gayle baldwin, high risk, immune cell, in vitro study, infected by virus, infected cells, james jung, jerome zack, life cycle, narcotics, quiescent, robert rovner, sexual behavior, sohn kim, substance abuse, susceptible to hiv

In many ways, the spread of HIV has been fueled by substance abuse. Shared needles and drug users’ high-risk sexual behaviors are just some of the ways that narcotics such as cocaine have played a key role in the AIDS epidemic in much of the world.

There is, however, relatively little research into how drugs can impact the body’s defenses against the virus. But a new UCLA study published in the October issue of the Journal of Leukocyte Biology examines how cocaine affects a unique population of immune cells called quiescent CD4 T cells, which are resistant to the virus that causes AIDS. (more…)

March of the Pathogens: Parasite Metabolism Can Foretell Disease Ranges under Climate Change

By Guest PostFebruary 27, 2013Environment, Scienceandrew dobson, Arctic, arctic climate, attitude, bacteria, body temperature, bryanne hoar, california santa barbara, climate change, cold blooded intermediate, disease causing parasite, disease ranges, earth grows warmer, ecology, emerging disease, environmental factors, environmental temperatures, equator, fundamental thermal niche, global warming, humans, infectious diseases, infectivity, life cycle, life cycle components, livestock, malaria, metabolic patterns, metabolic theory, microorganism, migrate, model, mortality, nematode, ostertagia gruehneri, parasite life cycle, parasite metabolism, pathogens, peter molnar, plasmodium, princeton university, range, reproduction, roundworm, ryan hechinger, sky is falling, susan kutz, temperatures, territory, university, university of calgary, viruses, wildlife, wooly bovine, worms

Knowing the temperatures that viruses, bacteria, worms and all other parasites need to grow and survive could help determine the future range of infectious diseases under climate change, according to new research.

Princeton University researchers developed a model that can identify the prospects for nearly any disease-causing parasite as the Earth grows warmer, even if little is known about the organism. Their method calculates how the projected temperature change for an area would alter the creature’s metabolism and life cycle, the researchers report in the journal Ecology Letters. (more…)

Biodiversity Protects Against Disease, Scientists Find

By Guest PostFebruary 15, 2013Natureamphibian eating birds, amphibian infections, amphibian species, aquatic parasite cycle, biodiversity, biodiversity matters, bird species, boulder, california tiger salamander, community of frogs, complex ecosystems, dan preston, decrease in disease, deformed frogs, disease transmission, doug levey, egrets, factor, grasslands, herons, humans, humans and wildlife, hypothesis, infection with ribeiroia, jason hoverman, katie richgels, large scale ecosystems, life cycle, lyme disease, malformations, national science foundation, northern leopard frog, organisms, parasite transmission, parasitic infections, pathogen, pieter johnson, pond, pond community, protects against disease, purdue university, replicate, reservoir hosts, ribeiroia ondatrae, salamanders, toads, university of colorado, west nile virus

Discovery resulted from study of amphibians in ponds

The richer the assortment of amphibian species in a pond, the more protection that community of frogs, toads and salamanders has against a parasitic infection that can cause severe deformities, including the growth of extra legs.

The findings, published in a paper in this week’s issue of the journal Nature, support the idea that greater biodiversity in large-scale ecosystems, such as forests or grasslands, may also provide greater protection against diseases, including those that affect humans.

A larger number of mammal species in an area may curb cases of Lyme disease, while a larger number of bird species may slow the spread of West Nile virus. (more…)

Public Acceptance of Climate Change Affected by Word Usage, Says MU Anthropologist

By Guest PostJanuary 24, 2013Culture, Environmentanthropologist, biodiversity, climate change, climate change keywords, culturgen, current era, database, degree of variation, earth, english language, environmental factors, evolution of species, Google, history, Holocene, ice cores, last ice age, life cycle, life forms, mainstream, michael obrien, ngram, organism, paleoclimate, phenology, pollen, popular vocabulary, prehistoric climate, public acceptance, rate, scientific journal, sediments, statistical analysis, tree rings, university of missouri, usage rates, william brock, words

Better science communication could lead to a more informed American public.

Public acceptance of climate change’s reality may have been influenced by the rate at which words moved from scientific journals into the mainstream, according to anthropologist Michael O’Brien, dean of the College of Arts and Science at the University of Missouri. A recent study of word usage in popular literature by O’Brien and his colleagues documented how the usage of certain words related to climate change has risen and fallen over the past two centuries. Understanding how word usage affects public acceptance of science could lead to better science communication and a more informed public.

“Scientists can learn from this study that the general public shouldn’t be expected to understand technical terms or be convinced by journal papers written in technical jargon,” O’Brien said. “Journalists must explain scientific terms in ways people can understand and thereby ease the movement of those terms into general speech. That can be a slow process. Several words related to climate change diffused into the popular vocabulary over a 30-50 year timeline.” (more…)

Non-native Plants Show a Greater Response Than Native Wildflowers to Climate Change

By Guest PostOctober 20, 2012Environment, Natureblooming pattern, changing climate, citizen scientist, climate change, columbus, data, flowering patterns, herbarium, invasive, kellen calinger, key driver, landscape, life cycle, native wildflower, Nature, non native, ohio, ohio wildflowers, peter curtis, plant species, state, state university, trumbull county, warming temperature, wildflower species

COLUMBUS, Ohio – Warming temperatures in Ohio are a key driver behind changes in the state’s landscape, and non-native plant species appear to be responding more strongly than native wildflowers to the changing climate, new research suggests.

This adaptive nature demonstrated by introduced species could serve them well as the climate continues to warm. At the same time, the non-natives’ potential ability to become even more invasive could threaten the survival of native species already under pressure from land-use changes, researchers say. (more…)

Surviving Without Ice

By Guest PostSeptember 15, 2012Environment, Natureamphipods, apherusa glacialis, arctic crustaceans, arctic ocean, disney movie, Environment, finding nemo, fram strait, geir johnsen, gulf stream, jorgen berge, life cycle, mark moline, melt, nemo hypothesis, north pole, ocean current, sea ice, shrimp

Arctic crustaceans use currents, deep-water migration to survive sea ice melts

With sea ice in the Arctic melting to record lows in summer months, marine animals living there face dramatic changes to their environment. Yet some crustaceans, previously thought to spend their entire lives on the underside of sea ice, were recently discovered to migrate deep underwater and follow ocean currents back to colder areas when ice disappears.

“Our findings provide a basic new understanding of the adaptations and biology of the ice-associated organisms within the Arctic Ocean,” said Mark Moline, director of the University of Delaware’s School of Marine Science and Policy in the College of Earth, Ocean, and Environment. “They also may ultimately change the perception of ice fauna as imminently threatened by the predicted disappearance of perennial sea ice.” (more…)

American Eels Return to Mountain Streams after Dam Removal

By Guest PostAugust 1, 2012Environment, Naturealan weaver, american eel, anguilla rostrata, atlantic coast, dam, dam removal, embrey dam, endangered species, fredericksburg, freshwater eel, freshwater stream, greenland, hydroelectric power, jeb wofford, life cycle, migration barrier, mountain streams, nathaniel hitt, rappahannock river, sargasso sea, sheila eyler, shenandoah national park, south america, usgs, virginia

Shenandoah National Park, Va. – American eels are declining across their range but are showing indications of a population revival following the removal of a large dam in Virginia.

The removal of Embrey Dam on the Rappahannock River increased American eel numbers in headwater streams nearly 100 miles away, according to research just published by U.S. Geological Survey, U.S. Fish and Wildlife Service, and National Park Service researchers.

American eels undergo long-distance migrations from their ocean spawning grounds in the Sargasso Sea to freshwater streams along the Atlantic coast from northern South America to Greenland. Dams may slow or even stop upstream eel migrations. However, prior to this research, little was known about American eel responses to dam removal. (more…)