Nov. 19, 2012
Tatar, a professor in the Division of Biology and Medicine at Brown State University, Providence, R.I., will speak on “Integrated Control of Drosophila Aging by Insulin/IGF (Insulin-Like Growth Factor) Signaling” at 6:15 p.m. in Ballroom A of the Activities and Recreation Center (ARC), UC Davis. Prior to the presentation, a wine and cheese reception will take place from 5 to 6 p.m. outside of Ballroom A.
The presentation will be recorded for later posting on the UCTV seminars.
Tatar has studied the demography, evolution and genetics of aging working with a variety of insect systems to explore the regulation and basic mechanisms of life history traits and senescence. The current work in the Tatar laboratory focuses on genetic analysis of Drosophila to understand how insulin/IGF signals and lipid hormones regulate aging, and how these endocrine signals interact with nutrition.
Tatar received his doctorate in ecology from UC Davis in 1994 while with the Graduate Group in Ecology, in the laboratory of James Carey, professor of entomology. He obtained his bachelor’s degree in biology in 1980 from Earlham College, Richmond, Ind., and went on to receive his master’s degree in zoology from UC Davis in 1984. He completed postdoctoral research in genetics at the University of Minnesota, St. Paul before joining the Brown University faculty in 1997. He was promoted to professor in 2007.
While at UC Davis, Tatar was the 1994 recipient of the Merton Love Award for his Outstanding Dissertation in Ecology and Evolution.
He is an Ellison Senior Scholar, founding joint editor-in-chief of the journal Aging Cell, and a past member of the Board of Review Editors for Science.
For further information on Marc Tatar's visit or to schedule appointments, contact Carey at jrcarey@ucdavis.edu.
The Dec. 5 seminar memorializes cotton entomologist Thomas Frances Leigh (1923-1993), an international authority on the biology, ecology and management of arthropod pests affecting cotton production. During his 37-year UC Davis career, he was based at the Shafter Research and Extension Center, also known as the U.S. Cotton Research Station. He researched pest and beneficial arthropod management in cotton fields, and host plant resistance in cotton to insects, mites, nematodes and diseases.
Leigh joined the UC Davis Department of Entomology in 1958, retiring in 1991 as an emeritus professor, but he continued to remain active in his research and collaboration until his death on Oct. 26, 1993.
At Shafter, Leigh focused his research on the biology, ecology, host plant resistance, control and management of insects and spider mites on cotton. He stood at the forefront of Integrated Pest Management (IPM) of cotton pests, according to an article in the summer 1994 edition of American Entomologist. He taught courses on cotton IPM and host plant resistance.
Leigh was born March 6, 1923 in Loma Linda. A 1942 graduate of Beaumont High School, he worked briefly on a farm and then served in the U.S. Army during World War II. He received his bachelor of science degree in entomology from UC Berkeley in 1949, and his doctorate in entomology there in 1956.
Leigh served as an assistant professor at the University of Arkansas from 1954 to 1958, where he worked on the biology, ecology and control of pink bollworm and boll weevil, using chemicals and cultural means. He joined the UC Davis Department of Entomology, advancing from assistant entomologist to associate entomologist in 1963. In 1968, he was promoted to adjunct lecturer and entomologist.
During his 37-year career, he authored more than 127 peer-reviewed publications.
In his memory, his family and associates set up the Leigh Distinguished Alumni Seminar in Entomology Fund at the UC Davis Department of Entomology. The alumni seminar is now known as the Thomas and Nina Distinguished Alumni Seminar, memorializing he and his wife, Nina Eremin Leigh (1929-2002). The couple raised two sons, Michael and Nicholas.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Nov. 19, 2012
The seminar, open to all interested persons, will be presented from 3:30 to 4:30 p.m. in 366 Briggs.
“Many stream invertebrates, including mayflies, drift downstream via the water column. Curiously, mayfly drift is often ~100X higher at night than during the day, and exhibits peaks at dusk and dawn,” the doctoral candidate said. Previous work indicates that trout presence causes the nocturnal timing of drift (there is no known cause of crepuscular drift).”
His abstract:
We asked whether invertebrate predators, by foraging nocturnally and at dawn and dusk, might also affect the the timing of drift. We found that invertebrate predator presence increased nocturnal drift rates more than diurnal drift rates, both in the presence and absence of trout, but were not the proximate cause of the crepuscular peaks in drift. We also quantified the relative importance of the causes of drift (i.e., food, benthic predation, and passive processes) across a canopy gradient.
“We found that diurnal foraging (i.e., drift) increased with increasing temperature in the absence of trout, but decreased with increasing temperature in the presence of trout. Thus, climate change is likely to increase divergence in mayfly behavior between invaded (trout-bearing) and un-invaded (fishless) streams in the Sierra Nevada. This divergence in behavior may have consequences for ecosystem structure.
Hammock, a doctoral candidate in ecology, has a bachelor's degree in forestry from UC Berkeley. Currently he's a teaching assistant for a statistics class. Over the years, he has TA'd various classes, including limnology and restoration ecology.
His future plans? "I'd love to keep teaching and doing research. He plans to begin a postdoc position in Swee Teh's lab, UC Davis School of Veterinary Medicine, this winter.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
DAVIS--A research presentation by UC Davis entomology graduate student Kevin Rayne Cloonan not only won a coveted award at the 60th meeting of the Entomological Society of America in Knoxville, Tenn., but may prove to be a boon to California almond growers.
Cloonan, who is studying for his master’s degree with chemical ecologist Walter Leal, professor of entomology, won a second-place award for his insect repellent research on the navel orangeworm (NOW), a major pest of California’s almond industry.
Cloonan presented his paper on “Potential Oviposition Repellent for the Navel Orangeworm (Amyelois transitella) in Almond Orchards of Central California.” For his research, he tested 20 broad spectrum insect repellents as potential oviposition repellents. Bedoukian Research Inc. developed the repellents.
Cloonan's work involved electrophysiological recordings, laboratory behavioral assays, and a field behavioral assay. He first used electroantennogram (EAG) assays to identify which of those 20 repellents the female antennae could detect. Of the 20 repellents, three showed significant EAG responses, he said.
In testing the oviposition repellency under laboratory conditions with laboratory populations, he found that two of the three repellents showed significantly reduced oviposition; they were then tested with field populations in almond orchards in Arbuckle.
“One especially looks very promising,” said Cloonan, adding “I couldn’t have done this research without the support and help of Dr. Leal and everyone in the Leal lab.”
Cloonan has been asked to present a poster at the Almond Board of California conference, to be held Dec. 11-13 at the Sacramento Convention Center.
At the ESA meeting, Cloonan’s presentation was one of 14 vying for top honors in the Plant-Insect Ecosytems (P-IE) Section. The P-IE Section includes behavioral, ecological, and evolutionary relationships in natural landscapes, as well as integrated pest management (IPM) in agriculture, horticulture, forests, and lawn and garden. The section also deals with aspects of crop protection, host-plant response, plant pathology/vectors, pollination, biological control, microbial control, and others.
Cloonan, who plans to pursue his doctorate in entomology, is a graduate of the University of Idaho, with a bachelor's degree in entomology.
The National Agricultural Statistics Service forecasts California’s 2012 almond crop at a record-breaking 2.10 billion meat pounds, valued at approximately $3 billion. Eighty-percent of the global supply of almonds is grown in California, and about 70 percent of California’s crop is marketed overseas.
Honey bees from all over the country are trucked to California to pollinate the state’s 780,000 acres of almonds, which begin blooming in mid-February, around Valentine's Day. Two bee colonies are required to pollinate each acre.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Nov. 14, 2012
DAVIS--Veterinarians at the University of California, Davis, School of Veterinary Medicine have announced plans to conduct the first clinical trial of an experimental drug that has shown promise in treating horses stricken with laminitis, an excruciatingly painful and often life-threatening foot-related disease.
Four horses suffering from laminitis have been treated with the investigational anti-inflammatory drug so far. One experienced a complete remission that has lasted for more than a year, and three others have shown some improvement.
A paper on the first laminitis case has been accepted for publication by the peer-reviewed Journal of Veterinary Anaesthesia and Analgesia. The paper is expected to be published in the journal's February issue, but journal editors authorized the authors to disclose their findings ahead of publication.
The horses were treated under a "compassionate use" protocol approved
by the UC Davis Institutional Animal Care and Use Committee. That protocol allows animals to be treated with an experimental drug if no approved alternative treatment exists.
A clinical trial to assess the drug's safety and establish a tolerable dose for the compound is expected to begin in the spring. Further clinical trials would be needed to establish the drug's effectiveness as a laminitis treatment.
Originally interested in finding biological insect control methods, Hammock has since broadened his research to also search for biomedical applications. He and colleagues have identified a group of anti-inflammatory compounds, including the sEH inhibitors, that have proven to be effective in relieving inflammatory discomfort and pain related to nervous system disorders in mice and rats. Their work has been published in scientific journals including the Proceedings of the National Academy of Sciences and the Journal of Medicinal Chemistry.
Guedes noted that the safe management of laminitis-related pain is one of the biggest challenges for equine veterinarians. Often, euthanasia is the only humane alternative for alleviating pain and suffering in horses afflicted with the condition.
Consequently, the survival rate for laminitis is estimated to be only 25 percent. Very few surviving horses return to their previous levels of activity, and laminitis often reappears.
In his upcoming paper, Guedes reports the case of a 4-year old Thoroughbred mare named Hulahalla that developed laminitis. The horse had been retired from racing following a tendon injury and donated to the UC Davis School of Veterinary Medicine, where it was participating in a study focused on healing tendon injuries using stem cell treatments.
Veterinarians from UC Davis' William R. Pritchard Veterinary Medical Teaching Hospital treated the laminitis with conventional therapies including cold immersion, antibiotics, leg wraps, and two commonly used nonsteroidal drugs intended to reduce inflammation and relieve pain -- but the horse only got worse. At the point that the mare was spending most of the day lying down, Guedes got involved.
Before resorting to euthanasia, Guedes and the veterinary team decided to try one last treatment, t-TUCB.
The veterinarians administered the experimental compound intravenously early on the eighth day of Hulahalla's illness. After receiving the first dose, the horse remained standing in the stall most of the day, became interested in her surroundings and walked voluntarily.
The mare's demeanor, posture and mobility continued to improve over four days of treatment, and her high blood pressure gradually returned to normal. No adverse affects from t-TUCB were observed, and Hulahalla has remained laminitis-free for a full year.
The sEH inhibitors, including t-TUCB, are currently available from the Hammock lab, which has provided the experimental compounds to more than 100 academic scientists around the world for basic investigation into their role in treating disease.
Hammock said that work aimed at moving t-TUCB and related compounds toward clinical use is advancing in several areas. He and Guedes are working on compounds with potential for targeting pain and arthritis in companion animals. And they are working with UC Davis to move the intellectual property from this research into a company to develop medications for difficult-to-manage neuropathic pain associated with diabetes and nerve injury.
Funding was provided by the National Institute of Environmental Health Sciences and the UC Davis Center for Equine Health.--Pat Bailey, UC Davis News Service
Note: The "before" and "after" photos of the horse depict Hulahalla, a three-year-old thoroughbred filly with acute laminitis in both front feet. The top photo shows her condition deteriorating (systolic blood pressure of over 200) and she refused to stand up. When given the compound, within three hours she was able to stand.
A video about one horse's remarkable recovery from laminitis after receiving the experimental drug is available at:
http://news.ucdavis.edu/search/news_detail.lasso?id=10385)
Media contact(s):
* Alonso Guedes, School of Veterinary Medicine, (530) 752-5565,
aguedes@ucdavis.edu
* Bruce Hammock, Entomology, (530) 752-7519, bdhammock@ucdavis.edu
* Pat Bailey, UC Davis News Service, (530) 752-9843,
pjbailey@ucdavis.edu
Nov. 13, 2012
Bergmann’s Rule, introduced by 19th century German biologist Carl Bergmann in 1847, proclaimed that cold-climate animals tend to be larger and stouter than animals living in hot or dry climates.
That is, animals living in higher latitudes, such as near the North or South Pole, tend to have a larger body mass than those living near the equator. Bergmann theorized that cold-climate animals need a higher surface-to-volume ratio to stay warm, while those living in hot and dry climates need a lower body surface area to accelerate heat loss and cool the body.
“Most warm blooded vertebrates like mammals and birds follow Bergmann's Rule consistently,” Shelomi said. “Whether the rule works or even applies to cold-blooded animals like insects is a matter of heated debate.”
Shelomi wondered if insects are more likely to (1) follow Bergmann’s Rule, (2) oppose the rule, or (3) show no ecogeographical pattern at all. So he reviewed nearly 140 published research papers disclosing more than 780 different patterns.
His research, “Where Are We Now? Bergmann’s Rule Sensu Lato in Insects,” published recently in the journal The American Naturalist, revealed a three-way tie. “Insects are just as likely to follow Bergmann’s Rule as they are to oppose it, and a slight majority show no size variation at all,” he said. (The metadata for the article is available for free:
http://datadryad.org/resource/doi:10.5061/dryad.hn356)
"So many factors affect insect size,” Shelomi said, “and there is so much variation in the types of insects and the areas where they live, that it's no surprise they don't all respond to changes in macroclimate in the same way.”
“If you measured a leg instead of a wing, or males instead of females, or covered continents instead of states, or looked at multiple species together instead of just one, your results would be different."
Shelomi cited 207 references, including “Size Distributions of Butterfly Species and the Effect of Latitude on Species Sizes” by N. D. Barlow published in 1994 in Oikos.
“Bergmann himself wrote the rule for homeothermic vertebrates (mammals and birds) and might have suggested the mechanism of thermoregulation; the smaller surface area–to-volume ratio of larger animals helps reduce heat loss in cold environments, and vice versa,” Shelomi wrote.
Shelomi's paper includes guidelines for future researchers to better design studies of insect and other animal size, to minimize error by accounting for natural variation.
"Some examples include examining one species at a time," Shelomi said, noting that interspecific studies (where multiple species were studied together) tended to be inconclusive or suggest no rules were operating, when in reality each individual species was following or countering Bergmann's Rule in its own way.
Closely related species could act very differently, Shelomi pointed out. “Likewise, studies that were too geographically broad, such as over multiple continents--or too small, such as a single city, tended to miss the real patterns behind the insect sizes.
"Whether Bergmann’s Rule applies to a particular taxon or clade is idiosyncratic to that group and its habitat and highly dependent on the study’s design," Shelomi said.
The UC Davis doctoral student, a graduate of Harvard with a bachelor’s degree in organismic and evolutionary biology, studies with major professor Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis. For his dissertation, he is researching the digestive system of Phasmatodea, an order of insects that includes walking sticks.
However, his research paper was related to his dissertation. He wrote the paper while enrolled in Art Shapiro's evolution and ecology class on biogeography.
“Professor Shapiro mentioned in class that a good final paper could be publishable, which I took as a challenge,” Shelomi said. “The result was I spent far more time reading articles and analyzing and reanalyzing the data than I expected. Fifty articles became 300, and soon a class essay became the biggest systematic review of insect morphometrics publications ever made, as far as I know."
Shelomi described the response from the scientific community as "positive."
“Almost immediately I began getting requests for reprints. As the paper deals with insects around the world, so I began getting emails from around the planet: Japan, Switzerland, Israel, etc. Naturally I got emails from some of the many authors I cited as well, some of whom shared my concerns that assemblage papers--those that try to draw conclusions from multiple species instead of just one--are not providing useful data.
And, by the way, he received an “A” on the paper from Shapiro.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
