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For over twenty-five years, the International Global Navigation Satellite System (GNSS) Service (IGS) has carried out its mission to advocate for and provide freely and openly available high-precision GNSS data and products.The IGS is an essential component of the IAG’s Global Geodetic Observing System (GGOS), where it facilitates cost-effective geometrical linkages with and among other precise geodetic observing techniques, including: Satellite Laser Ranging (SLR), Very Long Baseline Interferometry (VLBI), and Doppler Orbitography and Radio Positioning Integrated by Satellite (DORIS). These linkages are fundamental to generating and accessing the International Terrestrial Reference Frame (ITRF). As it enters its second quarter-century, the IGS is evolving into a truly multi-GNSS service, and at its heart is a strong culture of sharing expertise, infrastructure, and other resources for the purpose of encouraging global best practices for developing and delivering GNSS data and products all over the world.This poster will present an update on current IGS products and operations, as well as highlights on recent organizational developments and community activities. The impacts and benefits of global cooperation and openly available data will be emphasized, and information about the IGS stations and network, contributions to the International Terrestrial Reference Frame solutions, and product applications will be presented. A summary of IGS products, with emphasis on analysis, coordination, applications, and their availability will be described. Information about efforts to form new groups supporting product generation within IGS open data and product policies will be included. Information about the themes and topics of discussion for the upcoming 2020 IGS Workshop in Boulder, Colorado, USA will also be provided.

The objective of this study was to determine the clonal relatedness of Mannheimia haemolytica isolates responsible for an outbreak of bovine respiratory disease in a commercial feedlot. The isolates were obtained from the lungs of 21 calves with fatal pneumonia that were part of a group of 206 total calves. All isolates were serotyped and analyzed by pulsed-field gel electrophoresis (PFGE) and for antibiotic sensitivity patterns. ELISA and immunoblotting assays were performed to compare serum antibody levels to M. haemolytica antigens in calves with fatal pneumonia to those calves that survived the outbreak. Isolates were categorized into 14 different PFGE groups based on 90% similarity. Two Group D isolates (1 and 6), and 3 Group H isolates (14, 15, and 16) were characterized as 100% similar. Antimicrobial susceptibility profiles defined 8 groups based on differences in patterns of resistance between isolates. The two 100% similar isolates from PFGE Group D were both in susceptibility Group 1. All but isolate 14 from PFGE Group H (3, 15, 16, and 19) were in susceptibility Group 4a. Serum antibody levels to M. haemolytica antigens in the dead calves were not different than the antibody levels in the 185 calves that survived the outbreak. Immunoblots of selected isolates from each of the PFGE groups demonstrated only minimal differences in antigenic profiles between strains when reacted with serum from calves that either died from or survived the outbreak. Based on the characteristics of these isolates, multiple strains of M. haemolytica were responsible for fatal pneumonia during this outbreak.

Over the past decade, 84 species of dragonflies and damselflies (Odonata) have been found in an area

Background: Care providers and surgeons prepare for cardiac surgery using case conferences to review, discuss, and run through the surgical procedure. Surgeons visualize a patient’s anatomy to decide the right surgical approach using magnetic resonance imaging and echocardiograms in a presurgical case planning session. Previous studies have shown that surgical errors can be reduced through the effective use of immersive virtual reality (VR) to visualize patient anatomy. However, inconsistent user interfaces, delegation of view control, and insufficient depth information cause user disorientation and interaction difficulties in using VR apps for case planning. Objective: The objective of the study was to evaluate and compare the usability of 2 commercially available VR apps—Bosc (Pyrus Medical systems) and Medical Holodeck (Nooon Web & IT GmbH)—using the Vive VR headset (HTC Corporation) to evaluate ease of use, physician attitudes toward VR technology, and viability for presurgical case planning. The role of medical libraries in advancing case planning is also explored. Methods: After screening a convenience sample of surgeons, fellows, and residents, ethnographic interviews were conducted to understand physician attitudes and experience with VR. Gaps in current case planning methods were also examined. We ran a usability study, employing a concurrent think-aloud protocol. To evaluate user satisfaction, we used the system usability scale (SUS) and the National Aeronautics and Space Administration-Task Load Index (NASA-TLX). A poststudy questionnaire was used to evaluate the VR experience and explore the role of medical libraries in advancing presurgical case planning. Semistructured interview data were analyzed using content analysis with feedback categorization. Results: Participants were residents, fellows, and surgeons from the University of Washington with a mean age of 41.5 (SD 11.67) years. A total of 8 surgeons participated in the usability study, 3 of whom had prior exposure to VR. Users found Medical Holodeck easier to use than Bosc. Mean adjusted NASA-TLX score for Medical Holodeck was 62.71 (SD 18.25) versus Bosc’s 40.87 (SD 13.90). Neither app passed the mean SUS score of 68 for an app to be considered usable, though Medical Holodeck (66.25 [SD 12.87]) scored a higher mean SUS than Bosc (37.19 [SD 22.41]). One user rated the Bosc usable, whereas 3 users rated Medical Holodeck usable. Conclusions: Interviews highlighted the importance of precise anatomical conceptualization in presurgical case planning and teaching, identifying it as the top reason for modifying a surgical procedure. The importance of standardized user interaction features such as labeling is justified. The study also sheds light on the new roles medical librarians can play in curating VR content and promoting interdisciplinary collaboration.

We theoretically demonstrate that metals can be useful for increasing the quality factor and confinement factor of a zinc oxide (ZnO) nanocavity. For small cavities, the advantages of low radiation loss and significant mode confinement due to metal coating outweigh the disadvantage of absorption loss from metal and efficiently lower the threshold material gain. The performances of ZnO cavities without metal coating, with aluminum (Al) coating, and with silver (Ag) coating are investigated. The results indicate that while surface-wave-like plasmonic modes are lossy due to metal loss, the performances of well-confined dielectric modes are indeed improved significantly as a result of metal. Both Al and Ag can significantly reduce the threshold material gain of the uncoated ZnO cavity from 16 613 cm-1 to less than 5000 cm-1. In particular, the threshold material gain of Ag-coated cavity is reduced to only 3206 cm-1.

Infrared (IR) spectra in the gas phase are reported for CF(2)=CHD and CF(2)=CD(2) in the region 350-4000 cm(-1). Ab initio calculations of an harmonic force-field and anharmonicity constants have been made with an MP2/aug-cc-pVTZ model. These enable a number of Fermi resonances in each species to be analyzed and a complete set of "observed" harmonic frequencies to be derived. The latter are combined with similar data for CF(2)=CH(2) in a scaling of the model harmonic force field to both anharmonic and harmonic frequencies. Inspection of the scale factors reveals minor defects of the model, evident in the out-of-plane wagging modes and in the CF stretch/CF stretch interaction force constant. Fermi resonance treatments involved in all isotopomers studied are compatible with the overall force-field refinement results. The treatment leaves a small anomaly in the (13)C shift on nu(1). Improved microwave spectra are reported for five isotopic species, and a semiexperimental equilibrium structure for F(2)C=CH(2) is determined and compared favorably with the structure obtained from new high-level ab initio calculations. Centrifugal distortion constants are predicted for the five isotopic species, and those for F(2)C=CH(2) are compared with values fit to microwave spectra.

Assignments of the vibrational fundamentals of cis - and trans -1,3,5-hexatriene are reevaluated with new infrared and Raman spectra and with quantum chemical predictions of intensities and anharmonic frequencies. The rotational structure is analyzed in the high-resolution (0.0013–0.0018 cm −1 ) infrared spectra of three C-type bands of the trans isomer and two C-type bands of the cis isomer. The bands for the trans isomer are at 1010.96 cm −1 ( ν 14 ), 900.908 cm −1 ( ν 16 ), and 683.46 cm −1 ( ν 17 ). Ground state (GS) rotational constants have been fitted to the combined ground state combination differences (GSCDs) for the three bands of the trans isomer. The bands for the cis isomer are at 907.70 cm −1 ( ν 33 ) and 587.89 cm −1 ( ν 35 ). GS rotational constants have been fitted to the combined GSCDs for the two bands of the cis isomer and compared with those obtained from microwave spectroscopy. Small inertial defects in the GSs confirm that both molecules are planar. Upper state rotational constants were fitted for all five bands.

High-resolution (0.0013 cm −1 ) infrared spectra have been recorded for trans,trans -1,4-difluorobutadiene (ttDFBD) and cis,cis- 1,4-difluorobutadiene (ccDFBD). The rotational structure in two C-type bands ( ν 10 and ν 12 ) and one A-type band ( ν 22 ) for ttDFBD and in two C-type bands ( ν 11 and ν 12 ) for ccDFBD has been analyzed. Ground state and upper state rotational constants, except for ν 10 of ttDFBD, have been fitted. Band centers are 934.1 cm −1 ( ν 10 ), 227.985 cm −1 ( ν 12 ), and 1087.919 cm −1 ( ν 22 ) for ttDFBD. Band centers are 762.891 cm −1 ( ν 11 ) and 327.497 cm −1 ( ν 12 ) for ccDFBD. The small inertial defects in the ground state confirm that both isomers are planar. Obtaining the ground state rotational constants for the two isomers of DFBD is a first step toward determining their semi-experimental equilibrium structures.

The discovery by Schwabl that maternal steroid hormones are transferred to the egg yolk and have effects on the phenotype of offspring revealed a new pathway for non-genetic maternal effects. The initial model relied on passive transfer. The thinking was that steroids passively entered the lipophillic yolk during yolk deposition and then were deposited in the yolk until they were passively delivered to the embryo as the yolk was used. Subsequent studies revealed that the system is much more dynamic than that. Here, we explore questions about how dynamic the system really is and look at questions like: Is transfer of maternal steroids to the yolk passive or is it actively regulated? At what stages of the maternal reproductive cycle are steroids transferred? During reproduction, how dynamic are the levels of yolk steroids? Especially in the case of potentially deleterious steroids (e.g., androgens in female offspring; glucocorticoids), once deposited can they come out of the yolk over time? Can they be metabolized by the yolk or by the embryo? During incubation, how much do steroid levels in the yolk change? Can steroids diffuse from the yolk to the embryo prior to yolk utilization? Does the embryo contribute to yolk steroid levels as it develops? We believe that comprehensive answers to questions like these will eventually allow us to generate a much more accurate and complete model of the transfer and utilization of yolk steroids and that this model will be much more dynamic and active than the one initially proposed.

The mechanisms by which testosterone regulates aggression are unclear and may involve changes that alter the activity levels of one or more brain nuclei. We estimate neural activity by counting immunopositive cells against phosphorylated cyclic AMP response element binding protein (pCREB). We demonstrate increased pCREB immunoreactivity within the dorsolateral subdivision of the ventromedial hypothalamus (VMHdl) following an aggressive encounter in male tree lizards Urosaurus ornatus. This immunoreactivity is induced both by exposure to and performance of aggressive behaviors. This dual activation of the VMHdl suggests its possible role as an integration center for assessment and expression of aggressive behavior. Furthermore, pCREB induction was greater in encounters involving higher frequency and intensity of aggressive display, demonstrating a direct relationship between neural activation and behavior. The VMHdl is also rich in steroid receptors. In a second experiment involving hormone manipulations, testosterone treatment increased aggression levels, though it did not increase the number of pCREB positive cells within the VMHdl. This lack of an effect of testosterone on pCREB induction within the VMHdl may be due to induction arising from the behaviors of conspecifics (especially in low-testosterone, low-aggression individuals), variation in aggression mediated by other variables, or regulation of aggression by circuits outside of the VMHdl. Together, these findings support a notion of the VMHdl as a nucleus involved in integrating afferent and efferent information within the neural aggression-control circuit.

The neuropeptide arginine vasotocin (AVT) and its mammalian homologue arginine vasopressin (AVP) are neuromodulators known to be steroid sensitive and associated with social behaviors in a number of vertebrate taxa. However, the role of AVT/P in the regulation of aggression remains unclear and contrasting effects of this peptide on aggression are seen in differing species and contexts. In this study, we used immunohistochemistry to examine the effects of testosterone on the AVT system in male and female tree lizards, Urosaurus ornatus, and to determine whether AVT is related to territorial aggression in this species. Tree lizards are a free-living species that exhibit natural hormonal fluctuations across breeding seasons. We detected a male-biased sexual dimorphism in centrally projecting AVT fibers within the limbic system. Furthermore, changes with season, reproductive state, and hormonal treatment suggest that testosterone regulates AVT immunoreactivity in limbic brain regions, especially in the bed nucleus of the stria terminalis. Testosterone also affects AVT immunoreactivity in peripherally projecting cell clusters, as well as the size of AVT cell bodies in the paraventricular nucleus. Although higher testosterone levels alter AVT immunoreactivity, and are known to increase the frequency and intensity of male-male aggression in this species, no individual correlations between AVT immunoreactivity and aggression were detected.

Summary 1When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes. 2Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals. 3We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed. 4These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.

SUMMARYPhysiological trade-offs arise because multiple processes compete for the same limiting resources. While competition for resources has been demonstrated between reproduction and immune function, the regulation of this competition remains unclear. Corticosterone (CORT) is a likely mediator due to its dual role in mobilizing energy stores throughout the body and regulating physiological responses to stressors. We manipulated CORT concentrations and resources in pre-reproductive and reproductive female tree lizards(Urosaurus ornatus) to test the hypothesis that CORT regulates the distribution of limiting resources between the reproductive and immune systems. To manipulate circulating concentrations of CORT we utilized a novel method of hormone implantation, in which a polymeric compound is mixed with hormone and injected in liquid form into the animal. After injection, the liquid quickly gels in situ forming a slow release hormone implant. This method of hormone delivery eliminated the need for substantial wounds to the animal or repeated handling required by other methods. In this study, the hormone-treated animals had plasma CORT concentrations comparable to high physiological concentrations. We found that CORT treatment suppressed immune function, but only when animals were energetically compromised. We assessed immune function by measuring the healing rate of a cutaneous biopsy. Healing was suppressed in all CORT-treated reproductive animals and in all CORT-treated animals (pre-reproductive and reproductive) undergoing food restriction, but CORT had no effect in ad libitum non-reproductive females. The context-dependent action of CORT renders its response adjustable to changing environmental conditions and may allow for the suppression of specific functions depending on resource availability.

Objective—To compare anamnestic antibody responses of dogs and cats with current versus out-of-date vaccination status. Design—Cross-sectional study. Animals—74 dogs and 33 cats. Procedures—Serum samples were obtained from dogs and cats that had been exposed to rabies and brought to a veterinarian for proactive serologic monitoring or that had been brought to a veterinarian for booster rabies vaccination. Blood samples were collected on the day of initial evaluation (day 0) and then again 5 to 15 days later. On day 0, a rabies vaccine was administered according to label recommendations. Paired serum samples were analyzed for antirabies antibodies by means of a rapid fluorescent focus inhibition test. Results—All animals had an antirabies antibody titer ≥ 0.5 IU/mL 5 to 15 days after booster vaccination. Dogs with an out-of-date vaccination status had a higher median increase in titer, higher median fold increase in titer, and higher median titer following booster vaccination, compared with dogs with current vaccination status. Most (26/33) cats, regardless of rabies vaccination status, had a titer ≥ 12 IU/mL 5 to 15 days after booster vaccination. Conclusions and Clinical Relevance—Results indicated that dogs with out-of-date vaccination status were not inferior in their antibody response following booster rabies vaccination, compared with dogs with current vaccination status. Findings supported immediate booster vaccination followed by observation for 45 days of dogs and cats with an out-of-date vaccination status that are exposed to rabies, as is the current practice for dogs and cats with current vaccination status.

The neural mechanisms by which steroid hormones regulate aggression are unclear. Although testosterone and its metabolites are involved in both the regulation of aggression and the maintenance of neural morphology, it is unknown whether these changes are functionally related. We addressed the hypothesis that parallel changes in steroid levels and brain volumes are involved in the regulation of adult aggression. We examined the relationships between seasonal hormone changes, aggressive behavior, and the volumes of limbic brain regions in free-living male and female tree lizards (Urosaurus ornatus). The brain nuclei that we examined included the lateral septum (LS), preoptic area (POA), amygdala (AMY), and ventromedial hypothalamus (VMH). We showed that the volumes of the POA and AMY in males and the POA in females vary with season. However, reproductive state (and thus hormonal state) was incompletely predictive of these seasonal changes in males and completely unrelated to changes in females. We also detected male-biased dimorphisms in volume of the POA, AMY, and a dorsolateral subnucleus of the VMH but did not detect a dimorphism between alternate male morphological phenotypes. Finally, we showed that circulating testosterone levels were higher in males exhibiting higher frequency and intensity of aggressive display to a conspecific, though brain nucleus volumes were unrelated to behavior. Our findings fail to support our hypothesis and suggest instead that plasma testosterone level covaries with aggression level and in a limited capacity with brain nucleus volumes but that these are largely unrelated relationships.

The 2,3-13C2 isotopomer of butadiene was synthesized, and its fundamental vibrational fundamentals were assigned from a study of its infrared and Raman spectra aided with quantum chemical predictions of frequencies, intensities, and Raman depolarization ratios. For two C-type bands in the high-resolution (0.002 cm−1) infrared spectrum, the rotational structure was analyzed. These bands are for ν11 (au) at 907.17 cm−1 and for ν12 (au) at 523.37 cm−1. Ground state and upper state rotational constants were fitted to Watson-type Hamiltonians with a full quartic set of centrifugal distortion constants and two sextic ones. For the ground state, A0 = 1.3545088(7) cm−1, B0 = 0.1469404(1) cm−1, and C0 = 0.1325838(2) cm−1. The small inertial defects of butadiene and two 13C2 isotopomers, as well as for five deuterium isotopomers as previously reported, confirm the planarity of the s-trans rotamer of butadiene.

Exposure to stress can affect an organism's partitioning of resources among immune function and other organismal functions. However, measuring immune function is often difficult. Recent studies show that the rate of cutaneous wound healing in laboratory rodents is a simple, integrated measure of stress-sensitive immune function. We investigated the use of this technique in tree lizards to test the hypotheses (1) that stress compromises wound healing and (2) that this effect is at least partially mediated by corticosterone. Laboratory-housed male tree lizards randomly assigned to the experimental and control treatment groups received a 3.5 mm cutaneous biopsy on the dorsal surface of the pelvis. Experimental group males were restrained in cloth bags for 60 min every day for 21 days during the healing profile, whereas control males were left in their cages. Wound sizes were measured every other day by image analysis. Control animals healed faster than stressed animals. The difference in wound surface area between the groups was most pronounced early in the healing profile. Stressed animals also had higher corticosterone levels and corticosterone was negatively correlated with healing rate in the stressed animals. These observations support both hypotheses that stress compromises healing and that corticosterone may act to mediate the effects of stress.

Butadiene-1- 13 C 1 was synthesized, and its high-resolution (0.002 cm −1 ) infrared spectrum was recorded for several bands in the mid-infrared region. A complete analysis of the rotational structure in the C-type band at 524.485 cm −1 for CH 2 twisting and a partial analysis of the rotational structure in the C-type bands at 900.0 and 909 cm −1 were performed. Of these latter two bands, which are of comparable intensity, the higher frequency one is largely CH 2 out-of-plane wagging and the lower frequency one is largely 13 CH 2 out-of-plane wagging. Taken together these bands correlate with one infrared-active a u fundamental and one Raman-active b g fundamental of butadiene. The ground state rotational constants are A =1.3887919 (6), B =0.1436683 (3), and C =0.1302251 (3) cm −1 , and upper state rotational constants are reported for the bands at 524.485 and 900.0 cm −1 . Medium resolution infrared and Raman spectra gave a complete assignment of the vibrational fundamentals, including 11 fundamentals observed directly for the first time.

Rotational constants for butadiene and butadiene-2,3-d2 are derived from the analysis of the rotational structure of bands in the high-resolution infrared (IR) spectra. Corresponding moments of inertia computed from three quantum chemical calculations agree acceptably with the experimental values. Evidence is growing that the CC bond lengthens some and the C–C bond shortens some in support of partial π-electron delocalization in butadiene. Refinements are made in the assignment of vibrational fundamentals of butadiene and butadiene-2,3-d2 from new observations of IR and Raman spectra of these species.

Testosterone is usually thought to be the major sex steroid regulating adult male territorial aggression in vertebrates. However, recent evidence has suggested a role for progesterone, as well as testosterone, in the organization of the two male reproductive phenotypes of tree lizards (Urosaurus ornatus), which differ in adult levels of territorial behavior. In the present experiment we tested whether progesterone and testosterone could also play an activational role in the expression of adult aggressive behavior. We subjected post-reproductive male tree lizards to the following treatments: sham surgery, castration, castration with progesterone supplementation, and castration with testosterone supplementation. We measured several different dimensions of aggressive behavior. Overall in these post-reproductive animals, the level of aggression from lowest to highest was: castrates, shams, progesterone-treated, and testosterone-treated. Although testosterone appears to be the more potent regulator of aggressive behavior, progesterone enhanced several measures of aggression suggesting that it could play a role in natural regulation of aggressive behavior. This initial study used very high levels of progesterone (similar to or above those experienced by hatchlings) to maximize the probability of detecting an effect. Further studies are needed to determine if natural adult progesterone levels are sufficiently high to influence aggressive behavior.

During development, sex steroids are important in establishing differences between males and females. However, sex steroids also are involved in the development and maintenance of individual differences in morphology and behavior within each sex. As adults, male tree lizards (Urosaurus ornatus) exhibit alternative reproductive tactics correlated with dewlap (throat fan) coloration. Males with orange-blue dewlaps are aggressive and territorial, whereas males with orange dewlaps are less aggressive and employ a satellite strategy. Dewlap coloration develops within the first 90 days after hatching and remains fixed throughout life. Recent work demonstrates that individual males differ in progesterone and testosterone secretion during development, suggesting that these hormones regulate the development of alternative male phenotypes. The current work uses in vitro incubation of adrenal and gonadal tissues to identify the source of progesterone and testosterone during the period of male differentiation and to follow ontogenetic changes in hormone release. The results indicate that, in all developmental stages sampled, adrenal incubations primarily contain progesterone and corticosterone whereas gonadal incubations contain primarily testosterone. These data indicate that the hatchling adrenal is the primary source of progesterone during early post-hatching development. Since progesterone has been demonstrated to play a role in the establishment of individual differences in morphology and behavior in male tree lizards, our results suggest that the hatchling adrenal gland plays an important role in post-hatching development of alternative male phenotypes.

Dominant and subordinate males respond differently to the stress of social interaction. After an hour of social interaction, subordinate male Anolis carolinensis have elevated serotonergic activity in hippocampus, but dominant males do not. In other species, and using other stressors, the activation of hippocampal serotonergic activity is much more rapid than one hour. To elucidate early stress responsiveness, adult male A. carolinensis were divided into four groups: isolated controls, and pairs of males sampled after 10, 20 or 40 minutes of aggressive interaction. Development of dominant-subordinate relationships was determined by behavior and by the celerity of eyespot darkening. Serotonergic activity in the hippocampus, nucleus accumbens and amygdala was elevated rapidly and equally in both dominant and subordinate males, as were plasma corticosterone concentrations. Serotonergic activity remained elevated through 40 minutes in hippocampus and nucleus accumbens. Only subordinate males had elevated corticosterone levels at 40 minutes. Social status does not impede socially induced stress responses. Rather, rapid regulation of serotonergic stress responses appears to be a mediating factor in determining both behavioral output and social status. Temporal expressions of monoaminergic and endocrine stress responses are distinctive between males of dominant and subordinate social status. Such temporal patterns of transmitter and glucocorticoid activity may reflect neurocircuitry adaptations that result in behavior modified to fit social status.

Understanding the relationship between energy metabolism and signals that regulate reproduction may provide insight into the coordination of the energetically costly behavioral and physiological events that occur during reproduction. Significant changes in the utilization of stored lipids may occur during reproduction and the patterns of utilization observed often differ between females and males. Changes in levels of stored lipid reserves have been described extensively in animals from many taxa, but detailed biochemical analyses of alterations in the enzymes and substrates regulating lipid metabolism during periods of active reproductive effort rarely have been performed. In addition, few studies have compared males and females from the same population during the same reproductive season. In this study we examined lipid metabolism in free-living female and male tree lizards across a single reproductive season. We measured lipid stores, circulating lipid substrates, and the activities of enzymes regulating lipid storage and release in both liver and adipose tissue. Overall, females and males showed significant variation in abdominal fat body mass, liver total lipid, the activity of an enzyme regulating fat storage (DGAT) in both of these tissues, and circulating free fatty acids across the reproductive season. In females, total fat body mass, adipose DGAT, liver lipid, and liver DGAT significantly varied across reproductive stage, with vitellogenic and Gravid females often at opposite extremes. In males, fat body mass and liver fat varied across reproductive stage (without significant variation in DGAT in either tissue), as did circulating glycerol and free fatty acids. Correlations among sex steroid hormone levels and lipid metabolism variables suggested a role for these hormones in producing the patterns observed in each sex and in the observed sex differences lipid metabolism.

The magnitude of the glucocorticoid response to a stressor can depend on both environmental and physiological context. One factor that has not been examined is whether females of different reproductive states have different responses to a stressor. We examined whether corticosterone (CORT) increased after a 10 min handling stress in oviparous female tree lizards (Urosaurus ornatus) that were vitellogenic (yolking follicles) or gravid (post-ovulatory). We found that stressed vitellogenic females had a large increase in plasma CORT whereas gravid females did not. Baseline levels of CORT in gravid females were relatively high and similar to those in stressed vitellogenic females. The lack of a stress response in gravid females may be due to an inability to secrete higher levels of CORT or a suppression of the stress response. In addition, within vitellogenic females, CORT was positively correlated with ovarian weight, suggesting that CORT may function in some aspect of ovarian development during vitellogenesis.

We investigated maternal-fetal hormone transfer in the mountain spiny lizard, Sceloporus jarrovi, a viviparous species with a simple chorioallantoic placenta. In one experiment, we examined the effect of elevated maternal progesterone on fetal and yolk hormone levels. Progesterone implants increased maternal progesterone nearly 100-fold; however, the resulting increase in fetal and yolk progesterone was only about 2% of that seen in mothers, providing evidence that the placenta buffers hormone diffusion. In addition, some effects of progesterone treatment differed between male and female fetuses, suggesting that this buffering may differ between the sexes. In a second experiment, we examined the relationship between maternal and fetal hormone levels in viviparous versus oviparous species. We measured endogenous progesterone, testosterone, estradiol, and corticosterone levels in pregnant S. jarrovi and their fetuses and neonates, and in gravid S. graciosus (an oviparous congener) and their fetuses and hatchlings. No clear relationship was identified between maternal and fetal or hatchling S. graciosus hormone levels. However, the data for S. jarrovi suggest that maternal hormones may inhibit perinatal hormone secretion. These findings indicate that, despite the relatively recent evolutionary origin and simple structure of the S. jarrovi placenta, mechanisms for placental mediation of the maternal-fetal endocrine relationship have evolved. Although the placenta appears to buffer hormone transport, maternal hormones can affect fetal and yolk hormone levels, suggesting that disruption of endocrine regulation could be a physiological cost of the evolution of viviparity.

Empirical tests of Einstein's metric theory of gravitation, even in the non- relativistic, weak-field limit, could play an important role in judging theory-driven extensions of the current Standard Model of fundamental interactions. Guided by Galileo's work and his own experiments, Newton formulated a theory of gravity in which the force of attraction between two bodies is independent of composition and proportional to the inertia of each, thereby transparently satisfying Galileo's empirically informed conjecture regarding the Universality of Free Fall. Similarly, Einstein honored the manifest success of Newton's theory by assuring that the linearized equations of GTR matched the Newtonian formalism under "classical" conditions. Each of these steps, however, was explicitly an approximation raised to the status of principle. Perhaps, at some level, Newtonian gravity does not accurately describe the physical interaction between uncharged, unmagnetized, macroscopic bits of ordinary matter. What if Newton were wrong? Detecting any significant deviation from Newtonian behavior, no matter how small, could provide new insights and possibly reveal new physics. In the context of physics as an empirical science, for us this yet unanswered question constitutes sufficient motivation to attempt precision measurements of the kind described here. In this paper we report the current status of a project to search for violation of the Newtonian inverse square law of gravity.

Bats have been implicated as potential carriers of Leptospira as a result of surveys, mostly in Australia and South America. We measured the prevalence of pathogenic leptospires in kidneys of bats from Kansas and Nebraska. From 7 August 2012 to 21 August 2012, we extracted DNA from kidneys of 98 big brown bats (Eptesicus fuscus) submitted and found negative for rabies. The DNA was processed in a two-step, seminested PCR assay with a dual-labeled Taqman probe specific for pathogenic leptospires. As a negative control, we used a saprophytic leptospire (Leptospira biflexa Patoc) and, as a pathogenic control, Leptospira interrogans Canicola. All bat kidneys were negative for pathogenic leptospires, suggesting that it is unlikely that the big brown bat, one of the most prevalent bat species in North America, is a reservoir for transmission of leptospires to dogs or humans.

Although female aggression is found in many species and in a variety of contexts, little is known about its physiological bases. To compare neuroendocrine responses to aggression in females and males, we staged aggressive interactions between free-living territorial mountain spiny lizards and same-sex intruders and measured brain monoamines, plasma steroid hormone levels, and plasma glucose levels. Both females and males that had participated in a staged aggressive interaction had similar changes in serotonin (5-HT) activity in telencephalic tissue punches as indicated by a lowered ratio of forebrain:brainstem 5-HT concentrations. In addition, both females and males had elevated plasma corticosterone (B) after an aggressive interaction when compared to controls. The only difference detected between males and females was that females had a higher ratio of forebrain:brainstem norepinephrine (NE) concentrations throughout the brain compared to males. Together, these data indicate that acute neural and hormonal responses that accompany aggressive interactions in females are similar to those in males.

The potential of mitotane (ortho, para′-DDD, commonly used to treat adrenal carcinomas in humans and dogs) was investigated as an alternative to surgical adrenalectomy in birds, salamanders, and lizards. House sparrows ( Passer domesticus ) were injected twice daily with vehicle or one of two doses of mitotane (225 or 450 mg/kg), and basal and stress-induced levels of corticosterone (CORT) were measured 3 and 5 days after injections. Mitotane reduced basal CORT levels to nondetectable and abolished stress-induced CORT increases by the 3rd day of treatment. In another study, a single injection of mitotane was effective in lowering endogenous CORT levels 36 h later, but levels had apparently recovered by 10 days after the injection. Mitotane did not effect testicular weights and had no detectable effect on testosterone levels. In contrast to its effects on house sparrows, mitotane did not lower endogenous CORT levels in either tiger salamanders ( Ambystoma tigrinum ) or tree lizards ( Urosaurus ornatus ), even at doses much higher than those used in house sparrows.

Resolution of the isomeric 2'-, 3'-, and 4'-fluoromandelic acids with (+)-(1S;2S)-pseudoephedrine in 95% ethanol produces both well and poorly discriminating, hydrated and unsolvated binary salts. Seven observed diastereomeric phases are represented by five crystal structure types including three of the four types observed in the pseudoephedrine mandelates. Type a: monoclinic hemihydrate less-soluble (L) (R)-3'-fluoromandelate and more-soluble (M) (R)-4'-fluoromandelate (I); type b: orthorhombic unsolvated M (S)-2'-fluoromandelate; type c: orthorhombic unsolvated L (R)-2'-fluoromandelate; type d: orthorhombic dihydrate M (S)-3'-fluoromandelate and L (S)-4'-fluoromandelate; type e: monoclinic unsolvated M (R)-4'-fluoromandelate (II). Largest (15-fold) discriminating solubilities in 95% ethanol are found between the diastereomers with 2'-fluoromandelic acid, 50% more than in the corresponding ephedrine system. Principle interionic interactions are hydrogen-bonds between protonated secondary ammonium ions and carboxylates. Infinite chains of these are found in type c, with a four-atom repeating unit H-N(+)-H.O(-C(-)-O) [C(2)(1)(4)], and in types b and d, with a six-atom repeating unit H-N(+)-H.O-C(-)-O [C(2)(2)(6)]. Water of crystallization intervenes in the chains of type a but not of type d hydrated salts, according with higher average dehydration temperatures in the former. Hydrated salts in general are excessively soluble in 95% ethanol.

This study examined the psychometric properties of the Anxiety Control Questionnaire (AxCQ), a recently developed 30-item instrument intended to assess an individual's perceived level of control over anxiety related events. The sample consisted of 303 college students (189 females, 110 males, 4 no response). Although the scale is reported to have a two factor solution, results of an exploratory factor analysis in this sample indicated a three factor solution was more appropriate. Significant correlations were found between the three factor scales (r's ranged from 0.28 to 0.62). Internal consistency appeared good for the total AxCQ and for the factor scales derived from both the two and three factor models. There were no significant gender differences. We conclude that the psychometric properties of the scale look promising, but recommend that the factor structure of the AxCQ continue to be explored.

Cognitive theories of panic disorder suggest that the catastrophic misinterpretation of bodily sensations is the trigger for a panic attack. A challenge to cognitive theories is the suggestion that dyspnea (shortness of breath) is central to the development of panic and that negative cognitions are by-products of panic. To examine these seemingly contradictory theoretical perspectives, the present study investigated panic symptomatology in a sample of patients with chronic shortness of breath (i.e. pulmonary patients). Past studies have shown an increased prevalence of panic in pulmonary patients, a finding that may be useful in elucidating panic etiology. The current sample of pulmonary patients (N=28) confirmed previous reports of high prevalence rates of panic in this population. Based on self-report of panic symptomatology, a total of nine patients (32%) met DSM-IV criteria that were consistent with panic disorder. Multivariate comparison of participants with and without panic symptomatology revealed that panickers had significantly higher levels of anxiety, depression and agoraphobic cognitions. However, these groups showed no significant differences on physiological measures of pulmonary functioning. The authors conclude that dyspnea alone is inadequate in predicting panic development. High levels of panic symptomatology in pulmonary samples may reflect increased opportunities for these patients to misinterpret bodily sensations and, in particular, their pulmonary symptoms.

In certain species, females are highly aggressive. For example, female mountain spiny lizards, Sceloporus jarrovi, express aggressive behaviours when defending their territories. Despite the occurrence of female aggression, relatively little is known about its underlying hormonal mediation. As a first step in understanding neuroendocrine mechanisms of female aggression, this study documented seasonal changes in territorial aggression, plasma steroid hormone levels, and reproductive condition in free-living female mountain spiny lizards. We determined how seasonal patterns of testosterone (T), oestradiol (E), dihydrotestosterone (DHT) and corticosterone (B) corresponded to seasonal patterns of aggression. At times of the year when females were most aggressive, plasma levels of T and E were elevated. At times of the year when females were least aggressive, plasma B was elevated. Furthermore, when levels of T were elevated, females were more aggressive, and when levels of B were elevated, females were less aggressive. Plasma levels of DHT were not associated with aggression. These seasonal patterns are consistent with the hypotheses that T, and perhaps E, promote female aggression, while B suppresses female aggression. Despite these associations of hormones and aggression, no hormone was associated with aggression in a one-to-one fashion. This suggests that if steroid hormones contribute to the expression of female aggression, they must interact with each other or with other factors (for example, other hormones, receptor levels, environmental factors) to mediate fully the expression of aggression. Copyright 1999 The Association for the Study of Animal Behaviour.

Abstract —The mechanisms of sodium-induced myocardial hypertrophy and vascular hypertrophy are poorly understood. We tested the hypothesis that a high sodium concentration can directly induce cellular hypertrophy. Neonatal rat myocardial myoblasts (MMbs) and vascular smooth muscle cells (VSMCs) were cultured in a 50:50 mixture of DMEM and M199 supplemented with 10% fetal bovine serum. When the monolayers reached ≈80% confluence, normal sodium medium (146 mmol/L) was replaced with high sodium media (152 mmol/L, 160 mmol/L, and 182 mmol/L) for up to 5 days. Increasing sodium from a baseline concentration of 146 mmol/L to the higher concentrations for 5 days caused dose-related increases in cell mean diameter, cell volume, and cellular protein content in both MMbs and VSMCs. Increasing the sodium concentration by only 4% (from 146 mmol/L to 152 mmol/L) caused the following respective changes in MMbs and VSMCs: 8.5% and 8.7% increase in cell mean diameter, 27.6% and 27.0% increase in cell volume, and 55.7% and 46.7% increase in cellular protein content. The rate of protein synthesis, expressed as [ 3 H]leucine incorporation, increased by 87% and 99% in MMbs after exposure to 152 mmol/L and 160 mmol/L sodium, respectively, compared with the 146-mmol/L sodium control group. Exposure of MMbs to medium with a sodium concentration of 10% above normal, ie, 160 mmol/L, caused a significant decrease (range, 26% to 44%) in the rate of protein degradation at multiple time points over a 48-hour period compared with normal sodium control cells. The increase in cellular protein content caused by 160 mmol/L sodium returned to normal within 3 days after MMbs were returned to a normal sodium medium. These findings support the hypothesis that sodium has a direct effect to induce cellular hypertrophy and may therefore be an important determinant in causing myocardial and/or vascular hypertrophy in subjects with increased sodium concentration in the extracellular fluid.

SYNOPSIS. An organism's phenotype results from an interaction of environment and genotype. Sex steroids play a role in translating sexual genotype into phenotype. The focus of this research has been to extend the model of sex steroid hormone action in sexual differentiation to individual variation in reproductive phenotype. The hypothesis generated, called the relative plasticity hypothesis, has been tested in a species with alternative phenotypes, tree lizards ( Urosaurus ornatus ). Such species are useful models for tests of these ideas because variation is extreme and easily studied. These tests have shown that permanent differentiation of the territorial and nonterritorial phenotypes is accomplished by hormonal mechanisms operating during early development. These are similar to organizational actions of hormones classically described for sexual differentiation. A unique finding of this work is that the adrenal hormone progesterone regulates differentiation of the two male types. Furthermore, the nonterritorial male tree lizard appears to conditionally switch tactics between sedentary satellite and nomadic behavior. Nomadic behavior is triggered under stressful environmental conditions. Nonterritorial tree lizards show greater inhibition of reproductive hormones following stress than do territorial tree lizards, suggesting that a differential sensitivity of reproductive hormones to stress is the endocrine basis of conditional tactic switching in this morph. This mechanism is similar to the classical activational effects of hormones. Together, these findings indicate that individual variation in sexual phenotype is produced by mechanisms similar to sexual differentiation. Further refinement of the models and integration with some evolutionary ideas is explored.

The present study investigated the relationship between functional status and panic disorder in patients with pulmonary disease. Functional status is a broad term used to describe the impact of pulmonary disease on activities of daily life. Researchers have shown that functional status is influenced not only by physiological variables but also by psychological factors. Given the increased prevalence rates of panic disorder and other psychiatric disorders reported in pulmonary patients, the functional status of pulmonary patients may become increasingly compromised by the presence of a psychological disorder such as panic disorder. Thus, we hypothesized that panic symptomatology played an important role in the functional status of pulmonary patients beyond the physiological effects of pulmonary disease. In this sample of pulmonary patients (N = 28), relative to non-panic-disordered participants, panic-disordered patients did not report significantly greater levels of dyspnea (p > .05). However, these groups did show significant differences on measures of functional status (p < .017). The results also indicated that anxiety and depression continued to correlate positively with functional status even after controlling for the effects of dyspnea. These findings suggest that although patients with panic symptoms report no differences in physiological functioning relative to patients without panic symptoms, individuals with panic experience greater disruption in their lives due to psychological factors than do individuals without panic symptoms. These findings highlight the need for the consideration of mental health concerns in patients with chronic pulmonary disease.

(+)-(1S;2S)-Pseudoephedrine and racemic mandelic acid form three distinct diastereomeric salts from solutions in 95% ethanol. The least-soluble phase, a hemihydrate, contains the (2R)-mandelate. A salt phase of intermediate solubility is the unsolvated double salt, containing both the (2R)- and the (2S)-mandelate. The most-soluble salt phase contains the (2S)-mandelate. Mandelate configuration and order of solubility (based on the heats of fusion) is inverted from that found in the same system synthesized from chiral base and acid, and then crystallized from benzene solution. The (2R)-mandelate hemihydrate (−H2O at 349.5K, mp 391K), monoclinic, P21, a = 6.788(5), b = 29.415(35), c = 9.488(10)A, β = 108.91(8)°, Z = 4 (2 ion-pairs/asymmetric unit). Intermediate double salt (2S)- and (2R)-mandelate, mp 377.6K, anorthic, P1, a = 7.758(4), b = 9.966(5), c = 13.366(6)A, α = 72.99(4), β = 79.98(4), γ = 70.51(4)°, Z = 1 (2 ion-pairs/asymmetric unit). The (2S)-mandelate (mp 386.2K), orthorhombic, P212121, a = 7.079(6), b = 13.443(10), c = 18.820(14)A, Z = 4 is identical to a salt made from a combination of enantiomeric moieties from benzene solution. While differing from ephedrine mandelates in configuration at one center, solubilities of pseudoephedrine mandelates in 95% ethanol are much larger. A comparison of molecular structure (non-polar and H-bonding) regions of pseudoephedrine and ephedrine mandelates shows similarities and differences that are tentatively linked to crystal properties. This study reemphasizes the necessity for consistency in solvent use in resolution and in phase identification and comparison because the phases produced are frequently dependent upon the solvent. Chirality 10:325–337, 1998. © 1998 Wiley-Liss, Inc.

Tree lizards (Urosaurus ornatus) vary in throat fan (dewlap) color. Earlier, we described five dewlap types (Orange, Orange-Blue, Yellow, Yellow-Blue, and Blue), and reported that only males had blue in the dewlap and that presence or absence of a discrete blue patch was correlated with male alternative reproductive phenotypes in a central Arizona population. Here, with a modified scheme characterizing two dewlap elements, background color (orange, yellow, blue) and blue patch occurrence, we assessed: (1) sexual, annual, and geographic variation in the frequencies of dewlap elements; (2) simple habitat correlates; and (3) the effects of laboratory rearing regime on dewlap type. Within a population, frequencies of males and females expressing orange or yellow backgrounds did not differ, suggesting that control of background is similar in the sexes. Within several populations, frequencies of the dewlap elements did not differ across years (and probably generations), indicating that phenotype frequencies are relatively stable. Among five populations frequencies of background colors varied, as did frequencies of male types (blue patch present or absent). Dewlap frequencies did not correlate with habitat (boulders or mesquite trees), although few populations were sampled. In male and female offspring reared from eggs to sexual maturity in a common-garden laboratory study, background color frequencies in both sexes and blue patch frequencies in males differed among offspring from different populations. Offspring frequencies matched respective parental population frequencies. Results suggest that among-population variation in frequencies of the two dewlap elements are mediated by differences in genetics, in maternal effects, or both. Thus, differences in male behavior functionally linked to the blue patch also may be controlled by genetic or maternal effects.

Changes in circulating glucocorticoid and androgen levels mediate agonistic behaviors in many vertebrates. Individual variation in the magnitude of the glucocorticoid response to stressful stimuli, the negative effects of elevated glucocorticoid levels on androgen levels, or both could mediate individual differences in subsequent agonistic behavior. In a series of previous studies, we found that both alternative male reproductive morphs in the tree lizard, Urosaurus ornatus, can exhibit elevated levels of plasma corticosterone following male–male encounters, but that the territorial morph appears less likely to exhibit coincident decreases in plasma testosterone. Two studies tested the hypothesis that the two morphs differ in the degree to which testosterone levels are influenced by elevated corticosterone levels. In the first study, physically restraining males elicited endogenous elevations of circulating corticosterone levels. Testosterone levels were significantly negatively correlated with corticosterone levels in the nonterritorial morph, but there was no correlation between levels of the two steroids in territorial males. In the second study, corticosterone levels were artificially elevated in free-living male tree lizards using a noninvasive dermal patch. This exogenous elevation of corticosterone significantly depressed testosterone levels in both morphs, but it produced a significantly greater depression in the nonterritorial morph. Nonterritorial males appear to be more sensitive than territorial males to the testosterone-suppressing effects of elevated circulating levels of corticosterone. This difference between the morphs in the effects of a stress hormone on the reproductive axis may be a fundamental part of the mechanism (1) underlying behavioral tactic switching within the nonterritorial morph or (2) contributing to behavioral differences between the morphs.

The “trial of the century"—the criminal prosecution of O. J. Simpson—has generated a great deal of concern about the criminal justice system. This article presents a case study of the O.J. Simpson criminal trial and the importance of the media to postmodern criminal justice. First, a synthesis of labeling theory and postmodernism leads the authors to describe the “demonization” of Simpson, the media‐generated process that transformed a cultural hero into a brutal murderer in a postmodern fall from grace. Second, several scenarios of postmodern media implosion embedded within the trial are described. The implications of the trial for postmodern criminal justice are also considered. These include social constructions of race and racial justice, the role of cameras in the courtroom drama, and the social construction of celebrities emerging from the trial.

The spadefoot toad, Scaphiopus couchii, is an explosively breeding, desert dwelling amphibian that shows two characteristics hypothesized to select for a dissociated breeding pattern: it lives in a harsh environment and it has a very short, but predictable breeding period. We tested the hypothesis that these factors select for a dissociated breeding cycle by measuring plasma steroid hormones and the gametogenic cycles in a free-living population of S. couchii. Blood and tissue samples were obtained from prebreeding, calling (males only), amplexed, and postbreeding toads. In males, plasma testosterone (T), dihydrotestosterone (DHT), and corticosterone (B) differed significantly among reproductive groups, with calling and amplexing toads having the highest levels of each of these steroids. In females, plasma T, DHT, B, progesterone (P), and estradiol (E2) were measured; all steroids except B changed significantly among mating groups. Plasma T and E2 were greatest in prebreeding and amplexed females, while P and DHT were highest only in amplexed females. Primary spermatogonia (SPG I), secondary spermatogonia (SPG II), spermatocytes, spermatids (SPT), and spermatozoa embedded in Sertoli cells (SPS) all changed significantly among male breeding groups. Although all stages were present in all breeding groups, early stages of spermatozoa (SPG I and SPG II) were greatest in postbreeding males, while late stages (SPT and SPS) were highest in prebreeding, calling, and amplexing males. In females, oocyte stages I, II, III, V, and VI and atretic follicles also differed significantly among mating groups. Prebreeding female ovaries were dominated by late-stage (V and VI) oocytes which were subsequently ovulated during amplexus. In postbreeding females, oogenesis was well under way as indicated by the rising numbers of stage II and III oocytes. These results indicate that aspects of gametogenesis occur during and after breeding in both sexes. Although the results demonstrate that gonadal activity was high during the period of sexual activity, suggesting that S. couchii most closely fits an associated pattern of reproduction as defined by Crews (1984, Horm. Behav. 18, 22-28), we also found that gonadal activity continued past the breeding season. For this reason, S. couchii does not completely conform to an associated pattern.

Few studies have examined the role of steroid hormones in mediating tactic-associated differences in male agonistic behaviour. Long-term (24 h) steroid hormone responses to winning staged male–male encounters in different morphs of free-living male tree lizards,Urosaurus ornatus, were studied. Males belong to either an aggressive, territorial (type) morph or to a less aggressive, non-territorial morph. On the day after winning a staged male–male encounter, males of the less aggressive morph showed elevated plasma levels of the stress hormone corticosterone and depressed levels of the sex steroid testosterone compared with controls of the same morph not subjected to an encounter. In contrast, males of the more aggressive, territorial morph that engaged in an encounter had levels of both hormones similar to controls. This morph difference in hormonal response is the first endocrine difference between adult males of the two tree lizard morphs detected to date; previous field and laboratory studies showed no morph difference in resting hormone levels or in hormonal responses 30 min following male–male encounters. The consequences of these morph differences in hormone responses to male–male interactions are unknown, but the hormonal changes in the less aggressive morph may (1) influence spontaneous agonistic behaviour, (2) influence agonistic behaviour in subsequent male–male interactions or (3) reflect morph differences in physiological capabilities related to energy expenditure during male–male interactions.

Male tree lizards (Urosaurus ornatus) exhibit permanent adult differences in color and size that are functionally linked with behavioral differences: males with a central blue throat patch are territorial, more aggressive, and smaller than males lacking the patch, who are nomads or satellites foregoing territory defense. Gonadectomy or long-lasting hormone implants in hatchlings affect the development of these permanent adult differences, but similar manipulations in adults are ineffective. Analogous early hormone actions in vertebrate sexual differentiation typically must occur during a critical period. Whether there is a critical period for early hormone actions affecting development of male types in tree lizards is unclear. We followed a protocol identical to our previous experiments on hatchlings, but we manipulated testosterone (T) in later-aged juveniles to determine if they remained sensitive to such hormone manipulations. Testosterone implants given at 60 days posthatching (day 60) did not alter adult throat color, indicating that sensitivity of throat color to T declines by day 60. This contrasts to our earlier work where adult color was affected by T manipulations on day 30. However, size and throat color responded differently to exogenous T, as juveniles given T implants at day 60 grew less than control-implanted males.

Across North America the skunk acts as a reservoir for several rabies virus variants. Some of these variants are geographically restricted in range as is the case for the California skunk variant and two distinct variants present in Mexico. In contrast the North Central and South Central skunk rabies viruses are dispersed in overlapping ranges over large areas of the Midwestern region of the United States with the former extending into southern parts of the Canadian prairies. Despite this extensive range, there has been only very limited molecular characterization of these two viral variants. This study has examined the genetic diversity of the rabies viruses associated with North American skunks, with particular emphasis on the South Central skunk variant which was found to comprise three distinct geographically restricted groups of viruses that could in some cases be further sub-divided. The phylogenetic relationships of these groups and sub-groups allowed us to infer the likely direction of spread of these variants in some instances. Patterns of amino acid replacement of North American skunk-associated rabies viruses for both the nucleoprotein and glycoprotein products are also examined. These patterns reflect the virus phylogeny but no amino acid residues associated specifically with the skunk host were identified.

Fitness tradeoffs are difficult to examine because many fitness variables are correlated and vary in the same direction. Phenotypic manipulation circumvents many of these difficulties, and here we used this technique to examine mechanisms for tradeoffs between increased aggression (territorial defense) and survivorship. The behavioral phenotype of male mountain spiny lizards (Sceloporus jarrovi) was manipulated with testosterone to increase territorial defense, a sexually selected trait. We previously demonstrated that increased territorial defense results in a decrease in survival caused by a lower ratio of energy intake to energy expenditure. Here we measured energy consumption of increased territorial aggression using the doubly labeled water technique in the field and compared males with and without testosterone implants (Fig. 1). In a supplementary study we measured standard metabolic rate using captive lizards given similar testosterone implants to examine if an increase in energy expenditure was a result of only an increase in standard metabolic rate (Fig. 3). Our results indicated that a primary contribution to tradeoffs between increased territorial defense and survivorship could be made by a 31% increase in energy expenditure in the field that is not due to an increase in standard metabolic rate.

Males of many species exhibit strongly dimorphic reproductive behavior and morphology associated with alternative reproductive tactics. Little is known about the physiological control of these individual differences. The relative plasticity hypothesis proposes that such within-sex differences arise from either organizational or activational actions of sex steroid hormones depending on whether adults can switch tactics or not. This hypothesis predicts that differences between individuals in a species where adults cannot switch between tactics (are "fixed") should be organized by early actions of hormones. Three experiments explored the possible organizational role of testosterone (T) on the development of male alternatives in the tree lizard (Urosaurus ornatus), which has two fixed male morphs. Orange (O) males have a mostly orange throat fan (dewlap), are non-territorial nomads, and are larger than orange-blue (OB) males which have an orange dewlap with a central blue patch and are territorial. In the first experiment intact males on the day of hatching were (1) sham-operated and implanted with empty capsules, (2) castrated, or (3) testosterone-implanted. As adults, the castration group had more O males than the control and the T-implanted group had more OB males than the control. Adult body size in castrated and T-implanted groups paralleled naturally occurring morph differences but both were smaller than controls. A second experiment with a lower dose yielded similar results for dewlap type and growth. In a third experiment, intact males were given an empty capsule or a T-implant at 30 days posthatching. Again, the frequency of OB males in the T-implanted group was significantly greater than that in the empty implant group, indicating that either the critical period extends past Day 30 or there is no well-defined critical period. Together, these results support the hypothesis that the organizational action of T or one of its metabolites contributes to the differentiation of these within-sex differences.

A major challenge in integrative biology is understanding the mechanisms by which organisms regulate trade-offs among various functions competing for limiting resources. Key among these competing processes is the maintenance of health and the production of offspring. Optimizing both, given limited resources, can prove challenging. The physiological and behavioral changes that occur during reproduction have been shown to greatly influence an organism's immune system, which can have consequences for susceptibility to disease. Likewise, investing in costly immunological defenses can impair reproductive function. However, the precise nature of these physiological and behavioral interactions appears to be greatly dependent upon the environmental context in which they occur. Here we take a comparative look at interactions between the reproductive and immune systems, including current immunological approaches, and discuss how similar studies can reveal vastly disparate results. Specifically, we highlight results from the ornate tree lizard (Urosuarus ornatus) and the Siberian hamster (Phodopus sungorus) model systems, which provide an example of current research in the field. Collectively, these results emphasize the importance of resource availability and an individual's energy stores for the existence of life-history trade-offs and the efficiency of physiological processes in general. Akin to Dobzhansky's famous line, like other aspects of biology, nothing in ecoimmunology seems to make sense except in the context of an organism's environment.