THE ART OF WAR: PATTERNS AND MECHANISMS UNDERLYING PREDATOR-INDUCED PLASTICITY OF AMPHIBIANS

Organisms often employ phenotypic plasticity as a strategy to cope with variable environments. This is particularly true of predation threats, wherein prey induce defenses to reduce detection or capture by predators. In order to produce appropriate defenses, prey must be able to discern useful information from environmental cues. Despite the pervasive production of inducible defenses, we understand very little of how much useful information is conveyed to organisms in cues, or how the subsequent plastic responses vary within groups of organisms. To address the need for comparative studies of phenotypic plasticity, we sought to examine morphological and behavioral defenses of five species of Ambystoma salamander larvae in response to larval dragonfly (Anax junius) chemical cues in a common garden environment. Dragonfly cues induced relatively few morphological changes across species. Likewise, salamanders did not vary in their refuge use during the experiment, though several species reduced their activity in the presence of predators early in development. Our results suggest that behavioral and morphological defenses in Ambystoma are highly variable among species and the genus appears to be less plastic than tadpoles and other salamander species. To understand what types of information prey are capable of responding to in their environment, we raised grey treefrog tadpoles (Hyla verisciolor) in the presence of cues isolated from different stages of an attack sequence by larval dragonflies (A. junius) or larval dragonflies THE ART OF WAR: PATTERNS AND MECHANISMS UNDERLYING PREDATOR-INDUCED PLASTICITY OF AMPHIBIANS Heather Michelle Shaffery, M.S. University of Pittsburgh, 2013 iv consuming different combinations of grey treefrog tadpoles and snails (Helisoma trivolvis) across different temporal sequences. When exposed to a predator consuming grey treefrogs, tadpoles reduced their activity, increased their hiding behavior, and induced deeper tails. As we exposed prey to more types of cues from an attack sequence, they also increased tail depth and hiding behavior but did not change their activity. Additionally, treefrog tadpoles generally increased their defense as the biomass of treefrogs consumed increased, regardless of whether heterospecifics were being consumed. Our results suggest that treefrogs can gain cue information from all portions of an attack sequence, and that both temporal patterns of feeding and diet content of predators influence the type and magnitude of induced prey defenses

I Don\u27t Care What You Used To Be (I Know What You Are Today) / words by Dubin Al and Jimmy Mc Hugh

Cover: drawing of a Caucasian couple; photo inset of Ruth Wales and Doris Relyea; Publisher: Jack Mills Inc. (New York)https://egrove.olemiss.edu/sharris_f/1015/thumbnail.jp

Measurement of the Double Longitudinal Spin Asymmetry in Inclusive Jet Production in Polarized p-p Collisions at √s = 200 GeV at STAR

One of the primary goals of the STAR spin program at RHIC is the measurement of the double longitudinal asymmetry ALL in inclusive jet production. This measurement will allow STAR to determine the polarized gluon distribution function DeltaG in the Bjorken x region of 0.03<x<0.3. Inclusive jet production is a theoretically desirable way to measure DeltaG, as it is independent of fragmentation functions. This contribution presents STAR's preliminary 2005 measurements of ALL for inclusive jet production extracted from 3.1 pb−1 of data at [square root of]s=200 GeV and 50% beam polarization. The asymmetry is calculated over the transverse momentum region 5 < pT < 30 GeV/c and compared with theoretical predictions incorporating several gluon polarization scenarios. Systematic uncertainties from false asymmetries, jet reconstruction, and triggering are discussed. At the present level of statistics, the measured asymmetry disfavors maximal gluon polarization but cannot yet distinguish between other theoretical scenarios

The Lover\u27s Cup

This documentary film, The Lover\u27s Cup is the story of a former Naval Officer from World War II, Dr. Phillip Trapp, who took Marines into the battle of Iwo Jima and lived to see the flag being raised on Mt. Suribachi. This 55-minute film explores his life experiences before, during and following World War II. His first-hand experiences are used to illustrate the Social and psychological impact of the Great Depression and World War II and his journey to overcome his adversity and create positive changes in the world through his subsequent education and service at the University of Arkansas and the community of Northwest Arkansas. The Lover\u27s Cup explores some of the factors, which helped shape what many have called The Greatest Generation. It also addresses the political and psychological ramifications of World War II and it\u27s differences to modern day world conflict. The film includes several interviews over the course of two years with Dr. Trapp. It also includes some re-enactments and extensive archival footage and photographs through the National Archives and Library of Congress. This is a character-driven narrative, using the Great Depression and World War II as vehicles to tell the story. The goal of this film is to help generate a renewed awareness, understanding and appreciation of the Greatest Generation, who will all soon be gone

Effects of prescribed fire on Cope’s Gray Treefrog (Hyla chrysoscelis) across habitat scales and life stages

Fire may alter both aquatic and terrestrial habitat used by all amphibian life stages, yet, our knowledge of its effects on amphibians is primarily limited to adult responses. I present an integrated approach to test the response of Cope’s Gray Treefrog (Hyla chrysoscelis) to fire by examining responses in tadpole performance and survivorship, adult abundance, and oviposition. Tadpoles raised with burned leaf litter had similar survival, but total mass and total length were 440% and 170% greater, respectively, for tadpoles raised in unburned litter. I assessed terrestrial and aquatic oviposition cues by embedding burned and unburned litter treatments within burned and unburned terrestrial plots. Oviposition was an order of magnitude higher in unburned plots, regardless of the litter treatment. This difference was not statistically significant or driven by adult abundance. My results indicate the need to explore the dynamic effects forest management practices can have on amphibians across life stages

Effects of the herbicide Roundup on freshwater microbial communities: a mesocosm study

The impact of the widely used herbicide glyphosate has been mainly studied in terrestrial weed control, laboratory bioassays, and field studies focusing on invertebrates, amphibians, and fishes. Despite the importance of phytoplankton and periphyton communities at the base of the aquatic food webs, fewer studies have investigated the effects of glyphosate on freshwater microbial assemblages. We assessed the effect of the commercial formulation Roundup using artificial earthen mesocosms. The herbicide was added at three doses: a control (without Roundup) and two treatments of 6 and 12 mg/L of the active ingredient (glyphosate). Estimates of the dissipation rate (k) were similar in the two treatments (half-lives of 5.77 and 7.37 d, respectively). The only two physicochemical parameters showing statistically significant differences between treatments and controls were the downward vertical spectral attenuation coefficient kd(λ), where λ is wavelength, and total phosphorus concentration (TP). At the end of the experiment, the treated mesocosms showed a significant increase in the ratio kd(490 nm)/kd(550 nm) and an eightfold increase in TP. Roundup affected the structure of phytoplankton and periphyton assemblages. Total micro- and nanophytoplankton decreased in abundance in treated mesocosms. In contrast, the abundance of picocyanobacteria increased by a factor of about 40. Primary production also increased in treated mesocosms (roughly by a factor of two). Similar patterns were observed in the periphytic assemblages, which showed an increased proportion of dead : live individuals and increased abundances of cyanobacteria (about 4.5-fold). Interestingly, the observed changes in the microbial assemblages were captured by the analysis of the pigment composition of the phytoplankton, the phytoplankton absorption spectra, and the analysis of the optical properties of the water. The observed changes in the structure of the microbial assemblages are more consistent with a direct toxicological effect of glyphosate rather than an indirect effect mediated by phosphorus enrichment.Fil: Pérez, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Torremorell, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Mugni, Hernan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; ArgentinaFil: Rodriguez, Patricia Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Vera, Maria Solange. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Do Nascimento, Mauro. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Allende, Luz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bustingorry, Jose Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Escaray, Francisco José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Ferraro, Marcela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Izaguirre, Irina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Pizarro, Haydee Norma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Bonetto, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; ArgentinaFil: Morris, Donald P.. Lehigh University; Estados UnidosFil: Zagarese, Horacio Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentin

Activity Level-Predation Risk Tradeoff in a Tadpole Guild: Implications for Community Organization Along the Hydroperiod Gradient

Increasing activity levels permit greater food intake for use towards growth and reproduction, consequently increasing predation risk via increased detection. Larval anurans are models to examine activity level-predation risk tradeoffs, as they occupy a variety of lentic habitats that impose constraints on the distribution and abundance of species. Ephemeral ponds have a low abundance and diversity of predators and as a result tadpole species tend to have high foraging rates for rapid development. Permanent ponds generally possess a greater diversity and abundance of predators and tadpoles inhabiting these locations tend to have low activity rates or chemical defenses to minimize predation risk. The objective of this research was to examine how interspecific variation in activity level and response to predation risk, corresponds to the distributions of tadpole species along the hydroperiod gradient. Furthermore, we examined the intraspecific variation in activity level among the species. We conducted a series of laboratory experiments in which we quantified baseline activity patterns and the change in activity after the addition of a predator or exposure to alarm cues, for 12 species of larval anurans native to East Texas. Species that maintained a high activity level generally occupied ephemeral ponds and species that maintained low activity levels generally occupied permanent ponds. Only one species (Gastrophryne carolinensis) decreased their activity level in the presence of predator cues or conspecific alarm cues. These results highlight this tradeoff can have consequences on the life histories of multiple species, providing insight into how it affects the organization of ecological communities

Different convection models in ATLAS

Convection is an important phenomenon in the atmospheres of A-type and cooler stars. A description of convection in ATLAS models is presented, together with details of how it is specified in model calculations. The effects of changing the treatment of convection on model structures and how this affects observable quantities are discussed. The role of microturbulence is examined, and its link to velocity fields within the atmosphere. Far from being free parameters, mixing-length and microturbulence should be constrained in model calculations.Comment: 7 pages, 6 figures. To appear in the proceedings of the Workshop "ATLAS 12 and related codes", Trieste, July 11-15, 200

Observations of convection in A-type stars

Convection and turbulence in stellar atmospheres have a significant effect on the emergent flux from A-type stars. The recent theoretical advancements in convection modelling have proved a challenge to the observers to obtain measurements with sufficient precision and accuracy to allow discrimination between the various predictions. A discussion of the current observational techniques used to evaluate the various convection theories is presented. These include filter photometry, spectrophotometry, hydrogen lines, and metal lines. The results from these techniques are given, along with the successes and limitations.Comment: 8 pages, 4 figures, Invited Lecture at IAU Symposium 224 "The A Star Puzzle", 7-13 July 2004, Poprad, Slovaki

Phenotypically Plastic Responses to Predation Risk Are Temperature Dependent

Predicting how organisms respond to climate change requires that we understand the temperature dependence of fitness in relevant ecological contexts (e.g., with or without predation risk). Predation risk often induces changes to life history traits that are themselves temperature dependent. We explore how perceived predation risk and temperature interact to determine fitness (indicated by the intrinsic rate of increase, r) through changes to its underlying components (net reproductive rate, generation time, and survival) in Daphnia magna. We exposed Daphnia to predation cues from dragonfly naiads early, late, or throughout their ontogeny. Predation risk increased r differentially across temperatures and depending on the timing of exposure to predation cues. The timing of predation risk likewise altered the temperature-dependent response of T and R0. Daphnia at hotter temperatures responded to predation risk by increasing r through a combination of increased R0 and decreased T that together countered an increase in mortality rate. However, only D. magna that experienced predation cues early in ontogeny showed elevated r at colder temperatures. These results highlight the fact that phenotypically plastic responses of life history traits to predation risk can be strongly temperature dependent