#Fossil of historys most successful mammal: Prehistoric rodent may have set the stage for life in trees,
herbivorous dietsthe 160 million-year-old fossil of an extinct rodent-like creature from China is helping to explain how multituberculates--the most evolutionarily successful and long-lived mammalian lineage in the fossil
record--achieved their dominance. This fossil find--the oldest ancestor in the multituberculate family tree--represents a newly discovered species known as Rugosodon eurasiaticus.
and tree-dwelling mammals. Chong-Xi Yuan from the Chinese Academy of Geological Sciences in Beijing China along with Chinese and American colleagues report their analysis of the fossil in the 16 august issue of Science.
Much like today's rodents they filled an extremely wide variety of niches--below the ground on the ground and in the trees--and this new fossil
which resembles a small rat or a chipmunk possessed many of the adaptations that subsequent species came to rely upon the researchers say.
The later multituberculates of the Cretaceous era and the Paleocene epoch are extremely functionally diverse: Some could jump some could burrow others could climb trees
What is surprising about this discovery is that these ankle features were already present in Rugosodon--a land-dwelling mammal he said.
and went extinct in the Oligocene epoch occupying a diverse range of habitats for more than 100 million years before they were competed out by more modern rodents.
Based on their findings the researchers suggest that such adaptations must have arisen very early in the evolution of the order setting the stage for the major diversification of rodent-like mammals that ensued.
#New species of carnivore looks like a cross between a house cat and a teddy bearobserved in the wild tucked away in museum collections
The olinguito (oh-lin-GHEE-toe) looks like a cross between a house cat and a teddy bear.
It is actually the latest scientifically documented member of the Family procyonidae which it shares with raccoons coatis kinkajous and olingos.
The 2-pound olinguito with its large eyes and woolly orange-brown fur is native to the cloud forests of Colombia and Ecuador as its scientific name neblina (Spanish for fog) hints.
The discovery of the olinguito shows us that the world is explored not yet completely its most basic secrets not yet revealed said Kristofer Helgen curator of mammals at the Smithsonian's National Museum of Natural history
and mammals like the endangered Amur (or Siberian) tiger Asiatic black bear and wild boar. Listed as Endangered by IUCN Blakiston's fish owl is restricted to riparian areas in Russia China Japan and possibly North korea.
and mammals such as SARS and bird flu represent 60 per cent of outbreaks. As well as representing a significant global health threat they also create a burden to public health systems and the global economy.
#Sugar toxic to mice in safe doses, test findswhen mice ate a diet of 25 percent extra sugar--the mouse equivalent of a healthy human diet plus three cans of soda daily--females died at twice the normal rate
and males were a quarter less likely to hold territory and reproduce according to a toxicity test developed at the University of Utah.
fed mice large doses of sugar disproportionate to the amount people consume in sweetened beverages baked goods and candy.
just as harmful to the health of mice as being inbred the offspring of first cousins. Even though the mice didn't become obese
and showed few metabolic symptoms the sensitive test showed they died more often and tended to have fewer babies says the study's first author James Ruff who recently earned his Ph d. at the University of Utah.
--and that are considered safe by regulatory agencies--impair the health of mice. The new toxicity test placed groups of mice in room-sized pens nicknamed mouse barns with multiple nest boxes--a much more realistic environment than small cages allowing the mice to compete more naturally for mates
and desirable territories and thereby revealing subtle toxic effects on their performance Potts says. This is a sensitive test for health
and vigor declines he says noting that in a previous study he used the same test to show how inbreeding hurt the health of mice.
The mice tell us the level of health degradation is almost identical from added-sugar and from cousin-level inbreeding.
A Mouse Diet Equal to What a Quarter of Americans Eatthe experimental diet in the study provided 25 percent of calories from added sugar--half fructose and half glucose--no matter how many calories the mice ate.
The diet fed to the mice with the 25 percent sugar-added diet is equivalent to the diet of a person who drinks three cans daily of sweetened soda pop plus a perfectly healthy no-sugar-added diet Potts says.
The researchers used a mouse supply company that makes specialized diets for research. Chow for the mice was a highly nutritious wheat-corn-soybean mix with vitamins and minerals.
For experimental mice glucose and fructose amounting to 25 percent of calories was included in the chow.
For control mice corn starch was used as a carbohydrate in place of the added sugars. House Mice Behaving Naturallymice often live in homes with people
so mice happen to be an excellent mammal to model human dietary issues because they've been living on the same diet as we have
ever since the agricultural revolution 10000 years ago Potts says. Mice typically used in labs come from strains bred in captivity for decades.
They lack the territoriality shown by wild mice. So the study used mice descended from wild house mice that were outbred to prevent inbreeding typical of lab mice.
They are highly competitive over food nesting sites and territories he says. This competition demands high performance from their bodies so
if there is a defect in any physiological systems they tend to do more poorly during high competition.
So Potts'new test--named the Organismal Performance Assay or OPA--uses mice in a more natural ecological context more likely to reveal toxic effects of whatever is being tested he says.
When you look at a mouse in a cage it's like trying to evaluate the performance of a car by turning it on in a garage Ruff says.
If it doesn't turn on you've got a problem. But just because it does turn on doesn't mean you don't have a problem.
A big room was divided into 11 mouse barns used for the new test. Six were used in the study.
Each mouse barn was divided by wire mesh fencing into six sections or territories but the mice could climb easily over the mesh.
Within each of the six sections was a nest box a feeding station and drinking water.
which mice entered via 2-inch holes at the bottom. Each bin had four nesting cages in it and an enclosed feeder.
Female mice had to nest communally in the trays. Running the Experimentthe mice in the experiment began with 156 founders that were bred in Potts'colony weaned at four weeks
and then assigned either to the added-sugar diet or the control diet with half the males and half the females on each diet.
The mice stayed in cages with siblings of the same sex (to prevent reproduction) for 26 weeks
Then the mice were placed in the mouse barns to live compete with each other and breed for 32 more weeks.
while in the mouse barns so the study only tested for differences caused by the mice eating different diets for the previous 26 weeks.
The founder mice had implanted microchips like those put in pets. Microchip readers were placed near the feeding stations to record which mice fed where and for how long.
A male was considered dominant if he made more than 75 percent of the visits by males to a given feeding station.
With the 156 founder mice (58 male 98 female) the researchers ran the experiment six times with an average of 26 mice per experiment:
Added Sugar Impairs Mouse Lifespan and Reproduction--After 32 weeks in mouse barns 35 percent of the females fed extra sugar died twice the 17 percent death rate for female control mice.
There was no difference in the 55 percent death among males who did did and not get added sugar.
control males occupied 47 percent of the territories while sugar-added mice controlled less than 36 percent.
Male mice shared the remaining 17 percent of territories. --Males on the added-sugar diet produced 25 percent fewer offspring than control males as determined by genetic analysis of the offspring.
The researchers studied another group of mice for metabolic changes. The only differences were minor:
cholesterol was elevated in sugar-fed mice and the ability to clear glucose from the blood was impaired in female sugar-fed mice.
The study found no difference between mice on a regular diet and mice with the 25 percent sugar-added diet
when it came to obesity fasting insulin levels fasting glucose or fasting triglycerides. Our test shows an adverse outcome from the added-sugar diet that couldn't be detected by conventional tests Potts says.
Human-made toxic substances in the environment potentially affect all of us and more are discovered continually Potts says.
The findings come from a multi-year airborne survey of atmospheric chemistry called HIAPER Pole-to-Pole Observations or HIPPO.
Taking advantage of the long-duration and high-altitude-profiling capabilities of the NSF Gulfstream V aircraft also known as HIAPER the HIPPO project was designed to take a'snapshot'of the global troposphere Earth's lowest atmospheric
Recent observations aboard the Gulfstream V were made during regular flights conducted during the HIPPO campaign from 2009 to 2011.
In particular lights that doubled as cellphone chargers helped small businesses in two ways: The lights kept an owner's store illuminated at night driving more traffic to it
and the owner could rent the light as a charger for customers'cellphones. Interestingly the researchers found that in all cases microentrepreneurs tended to prefer products that were not necessarily the cheapest available:
The research team developing the drug--led by scientists at the Nanomedicine Research center part of the Maxine Dunitz Neurosurgical Institute in the Department of Neurosurgery at Cedars-Sinai Medical center--conducted the study in laboratory mice with implanted human
Mice receiving the drug lived significantly longer than untreated counterparts and those receiving only certain components of the drug according to a recent article in the Journal of Controlled Release.
NASA satellites used to predict zebra migrationsone of the world's longest migrations of zebras occurs in the African nation of Botswana
and where zebras will move has not been possible until now. Using NASA rain and vegetation data researchers can track
if zebras will make the trek or if the animals find poor conditions en route understand why they will turn back.
Covering an area of approximately 8500 square miles (22000 square kilometers) Botswana's Okavango Delta is one end of the second-longest zebra migration On earth a 360-mile (580-kilometer) round trip
Zebras walk an unmarked route that takes them to the next best place for grazing while overhead thundering cloudbursts of late October rains drive new plant growth filling pockmarks across this largest inland delta in the world.
High above Earth-orbiting satellites capture images of the zebras'movements on this epic trek as well as the daily change in environmental conditions.
Zebras don't need data to know when it's time to find better forage: The surge of rain-coaxed grasses greening is their prompt to depart.
and predict when the zebras will move. Pieter Beck research associate with the Woods Hole Research center in Falmouth Mass
Zebra mind: A band of scientists earn their stripesthe Zebra Migration Research Project began in 2008 after Hattie Bartlam-Brooks
and her team discovered the migration during field work for Okavango Herbivore Research. Anecdotal evidence--unverified stories--prior to the 1970s described a zebra migration from the Okavango Delta to the Makgadikgadi Salt Pans at the start of the rainy season in September
and continuing through April but from 1968 to 2004 veterinary fences prevented zebras from making the migration.
The veterinary fences--which had been built to keep wild buffalo from transferring diseases to cattle--were taken down in 2004.
Within three years of the removal of the veterinary fences zebra began making movements on the migration path toward the Makgadikgadi Salt Pans.
These movements were recorded by GPS collars that were fitted to zebra mares allowing researchers to accurately record their movements.
Zebras in the wild live for about 12 years so the migration path could not have been learned from previous generations said Bartlam-Brooks.
She and her team in the field observed that the zebras began their migration at the onset of the rains so she joined forces with Beck to see how extensive the environment's influence is on the timing of the zebras'journey.
Beck and his team learned that zebras do not follow an internal clock nor do they migrate at a steady pace.
when zebras started migrating and how fast they migrated. By comparing the results of the models it was possible to determine which environmental variables are the most effective in predicting zebra movement
and then use this knowledge to try and infer as to how the zebra make their decisions said Gil Bohrer assistant professor in the Department of Civil Environmental and Geodetic Engineering at The Ohio State university who collaborated on the project.
It shows we can figure out very closely what'makes the zebra move.''Bill Fagan professor of biology at the University of Maryland finds hope in the team's discoveries.
Their discussion he said was particularly intriguing as a demonstration of how important the consistency
The models provided the team with the means to think like a zebra which has practical applications in management issues that concern humans.
whether it's zebras or other migratory animals. Understanding the mechanisms that drive migratory behavior is increasingly important Beck said in terms of climate change as migrating animals rely on multiple habitats.
Helping zebras continue a journey--newly discovered by the animals and their observers--may allow them to cope with changes in their environment an outcome that is not so black-and-white.
The disease is spread by black-legged ticks which feed on infected mice and other small mammals. Foxes and other mammal predators help control the disease by keeping small mammal populations in check.
The decline of these mammal predators may be a factor in Lyme disease's prevalence among humans.
Kabay used published studies of timber rattlers'diets at four Eastern forest sites to estimate the number of small mammals the snakes consume
and matched that with information on the average number of ticks each small mammal carried. The results showed that each timber rattler removed 2500-4500 ticks from each site annually.
#Conservation efforts might encourage some to hunt lionsconventional wisdom holds that East Africa's Maasai pastoralists hunt lions for two distinct reasons:
to retaliate against lions that kill livestock or to engage in a cultural rite of passage.
Further some conservation initiatives including those designed to save lions from being hunted have failed either to work
or in some cases appear to have incited Maasai to hunt more lions as a form of political protest the researchers report.
because it's harder to control the hunting of lions unless society knows precisely why lions are hunted the researchers contend.
Many populations of Panthera leo--African lions--are falling and the species is classified as vulnerable on the International Union for Conservation of Nature and Natural resources'Red List.
Lion hunting is outlawed in Kenya and in Tanzania is limited to mostly tourists hunting with permits
unless the hunt is to eliminate a lion in defense of life or livestock. Still lion hunting regularly occurs in both countries usually without the hunters'following the law.
We saw an inaccurate representation of the exact reasons for why Maasai hunt lions and we had a lot of ethnographic background to correct that said Mara J. Goldman the assistant professor of geography at CU-Boulder who led the study.
Goldman collaborated with Joana Roque de Pinho a postdoctoral researcher at the Universidade T cnica de Lisboa Portugal
and Jennifer Perry a CU-Boulder geography alumna now studying law at the university. Goldman and her fellow researchers conducted 246 in depth interviews of Tanzanian and Kenyan Maasai between 2004 and 2008.
They found that Maasai hunt lions for multiple overlapping reasons some relating to predation on livestock and some not.
In some cases Maasai said they hunted lions to prevent the potential killing of livestock especially by lions that had killed livestock before rather than just as retaliation.
And while Maasai still celebrate successful lion hunts and the prowess of the warriors who hunt that cultural tradition can be less of a motivation to hunt than political discontent.
In Kenya for instance conservation programs aim to curb Maasai lion hunting by financially compensating Maasai for livestock killed by lions.
In Tanzania suggestions have been made by some to start such'compensation'programs but the Maasai themselves explain why this strategy has limitations:
because the lion will keep coming back to eat cattle until all the cattle are gone. And then what will we do with the money?
In the beginning the elders kept the warriors from hunting lions the researchers found. But after Maasai representation in ranch governance was diminished the Maasai felt disenfranchised.
Lion hunting increased in frequency and severity and was discouraged no longer by elders the researchers said.
and social customs and most recently for their lion-hunting practices. Although the primary motivations for lion hunting differed somewhat between Tanzania
and Kenya the researchers emphasize that Maasai have multiple overlapping reasons to hunt lions: to reaffirm the protective role of young warriors to help select brave leaders among warrior groups to allow individual warriors to gain prestige to eliminate lions that prey on livestock
and to prevent lions from becoming habituated to eating livestock and sometimes harming people. The multiple reasons illustrate the limitations of explaining Maasai lion hunting as either a cultural manhood ritual
or a retaliatory act the researchers write. Participatory conservation interventions that respect Maasai knowledge and promote full engagement with management processes are likely to have far better success in persuading Maasai to change
or moderate such behaviors themselves the research team states adding that lion conservation projects rarely address such complex politics.
Goldman also a faculty research associate at CU-Boulder's Institute of Behavioral Science is the first author on the study that was published recently online in the journal Oryx
and is scheduled to appear in the journal's October print edition. Story Source: The above story is provided based on materials by University of Colorado at Boulder.
and food webs that did not sustain the abundance of large sharks whales seabirds and seals of the modern ocean.
Indeed large marine animals--sharks tunas whales seals even seabirds--mostly became abundant when algae became large enough to support top predators in the cold oceans of recent geologic times.
The tiny algae of the greenhouse world were just too small to support big animals said Norris. It's like trying to keep lions happy on mice instead of antelope;
lions can't get by on only tiny snacks. Within the greenhouse world there were rapid warming events that resemble our projected future.
and the University of Cambridge has revealed the first steps of evolution in gene regulation in mice.
We found an impressive amount of variation between these apparently very similar mice in terms of transcription-factor binding which is an important indicator of gene-regulation activity says Paul Flicek of EMBL-EBI.
The team studied gene expression in five very closely related mouse species in order to pinpoint changes at the very earliest stages of evolution.
or off in liver cells in the different mouse species. By looking at mice that are very closely related to each other we were able to capture a snapshot of
In this study instead of comparing leaf and fruit shapes the team looked at gene regulation in mice that had diverged only recently from one another.
They found that there were a lot more differences between closely related mouse strains than there are between distantly related fruit-fly strains.
Mammals have lots of DNA kicking around that doesn't code for proteins while fruit flies have relatively little.
So a mouse's regulatory wiring will just have a lot more wiggle room than a fruit fly's says Paul.
Published in Biological Psychiatry the Pitt team found that in a rodent model second-generation deficiencies of omega-3s caused elevated states of anxiety
Performing experiments in rats in Moghaddam's laboratory the research team examined a second generation of omega-3-deficient diets mimicking present-day adolescents.
#Of bears and berries: Return of wolves aids grizzly bears in Yellowstonea new study suggests that the return of wolves to Yellowstone national park is beginning to bring back a key part of the diet of grizzly bears that has been missing for much of the past century--berries that help bears
put on fat before going into hibernation. It's one of the first reports to identify the interactions between these large important predators based on complex ecological processes.
The researchers found that the level of berries consumed by Yellowstone grizzlies is significantly higher
now that shrubs are starting to recover following the re-introduction of wolves which have reduced over-browsing by elk herds.
The berry bushes also produce flowers of value to pollinators like butterflies insects and hummingbirds; food for other small and large mammals;
and special benefits to birds. The report said that berries may be sufficiently important to grizzly bear diet
and health that they could be considered in legal disputes--as is white pine nut availability now--about
whether or not to change the threatened status of grizzly bears under the Endangered Species Act.
Wild fruit is typically an important part of grizzly bear diet especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation said William Ripple a professor in the OSU Department of Forest Ecosystems
Berries are one part of a diverse food source that aids bear survival and reproduction and at certain times of the year can be more than half their diet in many places in North america.
When wolves were removed from Yellowstone early in the 1900s increased browsing by elk herds caused the demise of young aspen
The recovery of those trees and other food sources since the re-introduction of wolves in the 1990s has had a profound impact on the Yellowstone ecosystem researchers say
Studies like this also point to the need for an ecologically effective number of wolves said co-author Robert Beschta an OSU professor emeritus.
As we learn more about the cascading effects they have on ecosystems the issue may be more than having just enough individual wolves
As wolves help reduce elk numbers in Yellowstone and allow tree and shrub recovery researchers said this improves the diet and health of grizzly bears.
In turn a healthy grizzly bear population provides a second avenue of control on wild ungulates especially on newborns in the spring time.
Yellowstone has a wide variety of nutritious berries--serviceberry chokecherry buffaloberry twinberry huckleberry and others--that are highly palatable to bears.
These shrubs are eaten also by elk and thus likely declined as elk populations grew over time.
With the return of wolves the new study found the percentage of fruit in grizzly bear scat in recent years almost doubled during August.
Because the abundant elk have been an important food for Yellowstone grizzly bears for the past half-century the increased supply of berries may help offset the reduced availability of elk in the bears'diet in recent years.
More research is needed regarding the effects of wolves on plants and animals consumed by grizzly bears.
There is precedent for high levels of ungulate herbivory causing problems for grizzly bears who are omnivores that eat both plants and animals.
Before going extinct in the American Southwest by the early 1900s grizzly bear diets shifted toward livestock depredation the report noted
because of lack of plant-based food caused by livestock overgrazing. And in the absence of wolves black bears went extinct on Anticosti Island in Canada after over-browsing of berry shrubs by introduced while-tailed deer.
Increases in berry production in Yellowstone may also provide a buffer against other ecosystem shifts the researchers noted--whitebark pine nut production a favored bear food may be facing pressure from climate change.
Grizzly bear survival declined during years of low nut production. Livestock grazing in grizzly bear habitat adjacent to the national park and bison herbivory in the park likely also contribute to high foraging pressure on shrubs
and forbs the report said. In addition to eliminating wolf-livestock conflicts retiring livestock allotments in the grizzly bear recovery zone adjacent to Yellowstone could benefit bears through increases in plant foods.
Story Source: The above story is provided based on materials by Oregon State university. Note: Materials may be edited for content and length.
Journal Reference e
#Head hits can be reduced in youth footballless contact during practice could mean a lot less exposure to head injuries for young football players according to researchers at Wake Forest Baptist Medical center and Virginia Tech.
Their study of 50 youth-league players ages 9 to 12--the largest ever conducted to measure the effects of head impacts in youth football--found that contact in practice not games was the most significant variable
when the number and force of head hits incurred over the course of a season were measured.
Coaching style also had a major influence on factors such as the types of drills used in practice
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