Category Archives: Nature

National Zoo and Partners First to Breed Critically Endangered Tree Frog

By Guest PostNovember 19, 2010Environment, Natureamphibians, atelopus limosus, brian gratwicke, chytridiomycosis, disease, extinction, frogs, harlequin frog species, hyloscirtus colymba, la loma tree frogs, limosa harlequin frog, panama, panama city, roberto ibáñez, smithsonian national zoo, species, tadpoles

Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the rescue project is the first to successfully breed this species. Image credit: Brian Gratwice, Smithsonian's National Zoo

As frogs around the world continue to disappear—many killed by a rapidly spreading disease called chytridiomycosis, which attacks the skin cells of amphibians—one critically endangered species has received an encouraging boost. Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue and Conservation Project is the first to successfully breed this species.

“We are some of the first researchers to attempt to breed these animals into captivity and we have very little information about how to care for them,” said Brian Gratwicke, international coordinator for the project and a research biologist at the Smithsonian’s National Zoo, one of nine project partners. “We were warned that we might not be able to keep these frogs alive, but through a little bit of guesswork, attention to detail and collaboration with other husbandry experts—we’ve managed to breed them. The lessons we’re learning have put us on target to save this incredible species and our other priority species in Panama.” (more…)

Mastermind Steroid Found in Plants

By Guest PostNovember 19, 2010Nature, Scienceanimal cells, arabidopsis, brassinosteroids, cellular functions, chain reactions, crop research, development, environmental stresses, genes, molecular links, plant growth, plant hormone, plant science, plant steroids, steroid, yu sun, zhi-yong wang

Palo Alto, CA — Scientists have known for some time how important plant steroids called brassinosteroids are for regulating plant growth and development. But until now, they did not know how extensive their reach is.

Now researchers, including Yu Sun and Zhi-Yong Wang at Carnegie’s Department of Plant Biology, have identified about a thousand brassinosteroid target genes, which reveal molecular links between the steroid and numerous cellular functions and other hormonal and light-activated chain reactions. The study, published in the November 16, 2010, issue of Developmental Cell, provides the first comprehensive action map for a plant hormone. The research will help accelerate basic plant science and crop research. (more…)

Tropical Forest Diversity Increased During Ancient Global Warming Event

By Guest PostNovember 18, 20101 commentEnvironment, Nature, Scienceangiosperm pollen, atmospheric carbon dioxide, carlos jaramillo, century, Colombia, eldredge bermingham, global warming, joe wright, outcrops, paleocene-eocene thermal maximum, panama, rainforests, scanning electron microscopy image, taxa, temperature increase, tropical areas, Venezuela

The steamiest places on the planet are getting warmer. Conservative estimates suggest that tropical areas can expect temperature increases of 3 degrees Celsius by the end of this century. Does global warming spell doom for rainforests? Maybe not. Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute, and colleagues report in the journal Science that nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.

About the image: This is a scanning electron microscopy image of characteristic angiosperm pollen taxa from the Paleocene-Eocene Thermal Maximum. Image credit: Francy Carvajal, Smithsonian Tropical Research Institute (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…)

Deformed Beaks May Signal a Greater Environmental Problem

By Guest PostNovember 9, 2010Environment, Natureagricultural runoff, alaska, avian keratin disorder, beak, beak abnormalities, bird, black capped chickadee, california, colleen handel, environmental health problem, great lakes, keratin layer, northwest, northwestern crow, selenium, usgs

This Black-capped Chickadee, captured in Anchorage, Alaska, demonstrates an overgrown beak characteristic of avian keratin disorder. Beak deformities in this species were first observed in the late 1990s and biologists have since documented more than 2,100 affected individuals in Alaska. Image credit: U.S. Geological Survey

ANCHORAGE, Alaska – The highest rate of beak abnormalities ever recorded in wild bird populations is being seen in a number of species in the Northwest and Alaska, and scientists to this point have not been able to isolate the cause.

Black-capped Chickadees, Northwestern Crows, and other birds are being impacted by the problem, which affects their ability to feed and clean themselves and could signal a growing environmental health problem.

In birds affected by what scientists have termed “avian keratin disorder,” the keratin layer of the beak becomes overgrown, resulting in noticeably elongated and often crossed beaks, sometimes accompanied by abnormal skin, legs, feet, claws and feathers. Biologists with the U.S. Geological Survey’s Alaska Science Center published their findings in this month’s issue of The Auk, a Quarterly Journal of Ornithology.

“The prevalence of these strange deformities is more than ten times what is normally expected in a wild bird population,” said research biologist Colleen Handel with the USGS, “We have seen effects not only on the birds’ survival rates, but also on their ability to reproduce and raise young. We are particularly concerned because we have not yet been able to determine the cause, despite testing for the most likely culprits.” (more…)

Volcanic Eruptions Affect Rainfall over Asian Monsoon Region

By Guest PostNovember 7, 2010Environment, Natureaffect, asian monsoon, climate, climate models, dinosaurs, el chichón, huaynaputina, indonesia, kevin anchukaitis, krakatau, mount pinatubo, neanderthals, particles, peru, Philippines, pinatubo, rainfall, solar energy, solar radiation, tambora eruption, tree ring lab, volcanic explosions, volcanoes, weather

Scientists have long known that large volcanic explosions can affect the weather by spewing particles that block solar energy and cool the air.

Some suspect that extended “volcanic winters” from gigantic eruptions helped kill off dinosaurs and Neanderthals.

In the summer following Indonesia’s 1815 Tambora eruption, frost wrecked crops as far away as New England, and the 1991 blowout of the Philippines’ Mount Pinatubo lowered average global temperatures by 0.7 degrees F — enough to mask the effects of greenhouse gases for a year or so. (more…)

The Genetics of Self-Incompatibility

By Guest PostNovember 6, 2010Nature, Scienceantigens, female, fertilization, genes, genetic, immune response, inbreeding, male, offspring, organism, petunia, petunia pistil, petunia pollen, plant, pollen, proteins, rna, rna-destroying enzyme, seiji takayama, sexual organs, t-cell receptors, teh-hui kao

*Petunias show that the mechanisms behind inbreeding prevention are similar to immune response*

About the image: The female part of the petunia flower secretes an enzyme that is designed to deter pollen tube growth, thereby preventing fertilization. However, in the cases that the pollen has come from a genetically different plant, the pollen produces its own protein that combats the pistil’s enzyme. With the enzyme out of the way, the pollen tube can keep growing and fertilization can occur. Image credit: Zina Deretsky, National Science Foundation

Inbreeding is a bad strategy for any organism, producing weak and problematic offspring. So imagine the challenge of inbreeding prevention in a plant where male and female sexual organs grow right next to each other! Such is the genetic conundrum faced by the petunia. (more…)

Simulating Human Decision-Making Could Improve Emergency Evacuation Planning

By Guest PostNovember 6, 2010Education, Environment, Naturecomputer simulation, effective law-enforcement, evacuations, seungho lee, traffic management, university of arizona

ANN ARBOR, Mich.—A unique disaster-response planning tool takes real-time human decision-making into account to determine effective law-enforcement strategies during evacuations. A University of Michigan researcher contributed to the development of the tool. (more…)