But what happens when a wasp lays its eggs but fails to pollinate the fig?
The findings suggest that when one species in a mutually beneficial relationship fails to hold up its end of the bargain, sanctions appears to be a necessary part of maintaining the relationship.
"We want to know what forces maintain this 80 million-year-old mutualism between figs and their wasp pollinators," said main author Charlotte Jandr, a Cornell graduate student in neurobiology and behavior, who conducted the study as a Smithsonian Tropical Research Institute predoctoral fellow. Edward Allen Herre, a staff scientist at the Smithsonian institute in Panama, co-authored the paper.
"What prevents the wasps from cheating and reaping the benefits of the relationship without paying the costs?" Jandr added.
More than 700 species each of fig trees and wasps have co-evolved in the tropics worldwide, with each fig tree species having its own species of pollinating wasp. Jandr worked on six fig tree-fig wasp pairs for the study. Some wasp species passively carry pollen that sticks to their bodies, while others actively collect pollen in special pouches.
The scientists observed that in passively pollinated pairings, the tree almost never aborted its fruit, and the wasp always carried pollen. However, the scientists observed that in actively pollinated pairings, where the wasp needs to expend energy to collect pollen, the tree dumped the fruit and killed the offspring when the wasps did not carry pollen.
The scientists also observed that among the actively pollinated fig species, pollen-free wasps were much more common when the trees had weak sanctions.
"Sanctions seem to be a necessary force in keeping this and other mutually beneficial relationships on track when being part of a mutualism is costly," said Jandr. "In our study, we saw less cheating when sanctions were stronger. Similar results have been found among human societies and social insects. It is very appealing to believe that the same general principles could help maintain cooperation both within and among species".
"We want to know what forces maintain this 80 million-year-old mutualism between figs and their wasp pollinators," said main author Charlotte Jandr, a Cornell graduate student in neurobiology and behavior, who conducted the study as a Smithsonian Tropical Research Institute predoctoral fellow. Edward Allen Herre, a staff scientist at the Smithsonian institute in Panama, co-authored the paper.
"What prevents the wasps from cheating and reaping the benefits of the relationship without paying the costs?" Jandr added.
More than 700 species each of fig trees and wasps have co-evolved in the tropics worldwide, with each fig tree species having its own species of pollinating wasp. Jandr worked on six fig tree-fig wasp pairs for the study. Some wasp species passively carry pollen that sticks to their bodies, while others actively collect pollen in special pouches.
The scientists observed that in passively pollinated pairings, the tree almost never aborted its fruit, and the wasp always carried pollen. However, the scientists observed that in actively pollinated pairings, where the wasp needs to expend energy to collect pollen, the tree dumped the fruit and killed the offspring when the wasps did not carry pollen.
The scientists also observed that among the actively pollinated fig species, pollen-free wasps were much more common when the trees had weak sanctions.
"Sanctions seem to be a necessary force in keeping this and other mutually beneficial relationships on track when being part of a mutualism is costly," said Jandr. "In our study, we saw less cheating when sanctions were stronger. Similar results have been found among human societies and social insects. It is very appealing to believe that the same general principles could help maintain cooperation both within and among species".
Deadly fish virus now found in all Great Lakes
A deadly fish virus that was first discovered in the Northeast in 2005 has been found for the first time in fish from Lake Superior, report Cornell researchers. That means that the virus has now been documented in all of the Great Lakes.
The viral hemorrhagic septicemia virus (VHSV), which causes fatal anemia and hemorrhaging in a number of fish species, poses no threat to humans, said Paul Bowser, professor of aquatic animal medicine at Cornell's College of Veterinary Medicine.
Bowser and his colleagues recently tested 874 fish from seven sites in Lake Superior in collaboration with the U.S. Geological Survey (USGS) Western Fisheries Research Center in Seattle. Fish from Paradise and Skanee in Michigan and St. Louis Bay and Superior Bay in Wisconsin tested positive. Some of the results have been corroborated by other laboratories; others have tests still under way.
The virus, which has been identified in 28 freshwater fish species in the Great Lakes watershed, has reached epidemic proportions in the Great Lakes and threatens New York's sport-fishing industry, said Bowser, estimated to contribute some $1.4 billion annually to New York's economy.
"People come from all over the eastern United States to fish the Great Lakes," said Bowser, noting that the virus has also been found in a few inland waters as well, including lakes, streams and a family-owned earthen pond. "The economy of a number of of these areas ebbs and flows with the season and perceived value of outdoor recreational opportunities. The value of these opportunities is dependent on how successful we are at managing the health of wild fish. On a worldwide basis, VHSV is considered one of the most serious pathogens of fish, because it kills so a number of fish, is not treatable and infects a broad range of fish species".........
The viral hemorrhagic septicemia virus (VHSV), which causes fatal anemia and hemorrhaging in a number of fish species, poses no threat to humans, said Paul Bowser, professor of aquatic animal medicine at Cornell's College of Veterinary Medicine.
Bowser and his colleagues recently tested 874 fish from seven sites in Lake Superior in collaboration with the U.S. Geological Survey (USGS) Western Fisheries Research Center in Seattle. Fish from Paradise and Skanee in Michigan and St. Louis Bay and Superior Bay in Wisconsin tested positive. Some of the results have been corroborated by other laboratories; others have tests still under way.
The virus, which has been identified in 28 freshwater fish species in the Great Lakes watershed, has reached epidemic proportions in the Great Lakes and threatens New York's sport-fishing industry, said Bowser, estimated to contribute some $1.4 billion annually to New York's economy.
"People come from all over the eastern United States to fish the Great Lakes," said Bowser, noting that the virus has also been found in a few inland waters as well, including lakes, streams and a family-owned earthen pond. "The economy of a number of of these areas ebbs and flows with the season and perceived value of outdoor recreational opportunities. The value of these opportunities is dependent on how successful we are at managing the health of wild fish. On a worldwide basis, VHSV is considered one of the most serious pathogens of fish, because it kills so a number of fish, is not treatable and infects a broad range of fish species".........
The Low Calorie Pet Foods
Dog and cat owners buying weight-control diets for their overweight pets are faced with a confusing two hundred percent variation in calorie density, recommended intake, and wide range cost of low-calorie pet foods, as per a research studyby the Cummings School of Veterinary Medicine at Tufts University.
The study, published this month in the Journal of the American Veterinary Medical Association, examined nearly 100 commercially available diets with weight management claims. Among their findings is that dry dog foods range in calorie density from 217 to 440 kilocalories per cup (kcal/cup) and a recommended intake that ranged from 0.73 to 1.47 times the dog's resting energy requirement. The diets also varied wildly in price-from 4 cents to more than $1.10 per kilocalorie.
Similar findings were made in wet dog food (189-398 kcal/can) and cat food (235-480 kcal/cup) marketed for weight control. The results appears to be significant for owners whose cats or dogs are overweight or obese, as per Lisa M. Freeman, DVM, PhD, DACVN, the study's co-author along with 2010 Cummings School graduate Deborah E. Linder, DVM. Nearly 50% of domesticated animals are overweight or obese.
"There is so much information-and misinformation-about pet foods, it's understandable that people are confused about what to feed their dogs and cats," said co-author Dr. Lisa Freeman, professor of nutrition at Tufts University's Cummings School of Veterinary Medicine. "To counteract these myths, people are accustomed to turning to the labels on food-but, as this study shows, packaging might not always be a reliable source of information".........
The study, published this month in the Journal of the American Veterinary Medical Association, examined nearly 100 commercially available diets with weight management claims. Among their findings is that dry dog foods range in calorie density from 217 to 440 kilocalories per cup (kcal/cup) and a recommended intake that ranged from 0.73 to 1.47 times the dog's resting energy requirement. The diets also varied wildly in price-from 4 cents to more than $1.10 per kilocalorie.
Similar findings were made in wet dog food (189-398 kcal/can) and cat food (235-480 kcal/cup) marketed for weight control. The results appears to be significant for owners whose cats or dogs are overweight or obese, as per Lisa M. Freeman, DVM, PhD, DACVN, the study's co-author along with 2010 Cummings School graduate Deborah E. Linder, DVM. Nearly 50% of domesticated animals are overweight or obese.
"There is so much information-and misinformation-about pet foods, it's understandable that people are confused about what to feed their dogs and cats," said co-author Dr. Lisa Freeman, professor of nutrition at Tufts University's Cummings School of Veterinary Medicine. "To counteract these myths, people are accustomed to turning to the labels on food-but, as this study shows, packaging might not always be a reliable source of information".........
Environmental threats to blue crabs
The Atlantic blue crab, Callinectes sapidus, long prized as a savory meal at a summer party or seafood restaurant, is a multi-million dollar source of income for those who harvest, process and market the crustacean along the U.S. Atlantic and Gulf coasts. Unfortunately, the blue crab population has been declining in recent years under the assault of viruses, bacteria and man-made contaminants. The signs of the attack often are subtle, so scientists from the National Institute of Standards and Technology (NIST) and the College of Charleston (CofC) are at work trying to identify the clues that will finger specific, yet elusive, culprits.
Pathogens and pollutants impair the blue crab's metabolic processes, the chemical reactions that produce energy for cells. These stresses should cause tell-tale changes in the levels of metabolites, small chemical compounds created during metabolism. Working at the Hollings Marine Laboratory (HML) in Charleston, S.C., the NIST/CofC research team is using a technology similar to magnetic resonance imaging (MRI) to identify and quantify the metabolites that increase in quantity under common environmental stresses to blue crabsmetabolites that could be used as biomarkers to identify the specific sources.
In a recent paper in Metabolomics,* the HML research team describes how it used nuclear magnetic resonance (NMR) spectroscopy to study challenges to one specific metabolic process in blue crabs: oxygen uptake. First, the scientists simulated an environmentally acquired bacterial infection by injecting crabs with the bacterium Vibrio campbellii. This pathogen impairs the crab's ability to incorporate oxygen during metabolism. Using NMR spectroscopy to observe the impact on metabolite levels, the scientists observed that the yield of glucose, considered a reliable indicator of mild oxygen starvation in crustaceans, was raised.........
Pathogens and pollutants impair the blue crab's metabolic processes, the chemical reactions that produce energy for cells. These stresses should cause tell-tale changes in the levels of metabolites, small chemical compounds created during metabolism. Working at the Hollings Marine Laboratory (HML) in Charleston, S.C., the NIST/CofC research team is using a technology similar to magnetic resonance imaging (MRI) to identify and quantify the metabolites that increase in quantity under common environmental stresses to blue crabsmetabolites that could be used as biomarkers to identify the specific sources.
In a recent paper in Metabolomics,* the HML research team describes how it used nuclear magnetic resonance (NMR) spectroscopy to study challenges to one specific metabolic process in blue crabs: oxygen uptake. First, the scientists simulated an environmentally acquired bacterial infection by injecting crabs with the bacterium Vibrio campbellii. This pathogen impairs the crab's ability to incorporate oxygen during metabolism. Using NMR spectroscopy to observe the impact on metabolite levels, the scientists observed that the yield of glucose, considered a reliable indicator of mild oxygen starvation in crustaceans, was raised.........
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