Rain, recreation and risk: Human activity and ecological disturbance create seasonal risk landscapes for the prey of an ambush predator.

Predation risk and prey responses exhibit fluctuations in space and time. Seasonal ecological disturbances can alter landscape structure and permeability to influence predator activity and efficacy, creating predictable patterns of risk for prey (seasonal risk landscapes). This may create corresponding seasonal shifts in antipredator behaviour, mediated by species ecology and trade-offs between risk and resources. Yet, how human recreation interacts with seasonal risk landscapes and antipredator behaviour remains understudied. In South Florida, we investigated the impact of a seasonal ecological disturbance, specifically flooding, which is inversely related to human activity, on interactions between Florida panthers (Puma concolor coryi) and white-tailed deer (Odocoileus virginianus). We hypothesized that human activity and ecological disturbances would interact with panther-deer ecology, resulting in the emergence of two distinct seasonal landscapes of predation risk and the corresponding antipredator responses. We conducted camera trap surveys across southwestern Florida to collect detection data on humans, panthers and deer. We analysed the influence of human site use and flooding on deer and panther detection probability, co-occurrence and diel activity during the flooded and dry seasons. Flooding led to decreased panther detections and increased deer detections, resulting in reduced deer-panther co-occurrence during the flooded season. Panthers exhibited increased nocturnality and reduced diel activity overlap with deer in areas with higher human activity. Supporting our hypothesis, panthers' avoidance of human recreation and flooding created distinct risk schedules for deer, driving their antipredator behaviour. Deer utilized flooded areas to spatially offset predation risk during the flooded season while increasing diurnal activity in response to human recreation during the dry season. We highlight the importance of understanding how competing risks and ecological disturbances influence predator and prey behaviour, leading to the generation of seasonal risk landscapes and antipredator responses. We emphasize the role of cyclical ecological disturbances in shaping dynamic predator-prey interactions. Furthermore, we highlight how human recreation may function as a 'temporal human shield,' altering seasonal risk landscapes and antipredator responses to reduce encounter rates between predators and prey.

Deer movement and resource selection during Hurricane Irma: implications for extreme climatic events and wildlife.

Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer (Odocoileus virginianus seminolus) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change.

Response to intravenous lidocaine infusion differs based on clinical diagnosis and site of nervous system injury.

We analyzed retrospectively pain relief from an intravenous lidocaine infusion (5 mg/kg/hr for 60 to 90 minutes) in 111 patients with chronic nonmalignant pain. Patients with peripheral nervous system (PNS) injury reported substantially more pain relief than those with central nervous system (CNS) injury or with pain of unknown etiology. These findings suggest that (1) the pathophysiology of chronic pain due to PNS injury is different from that due to CNS injury and idiopathic pain, and that (2) pain due to PNS damage may be suppressible by local anesthetic antiarrhythmic agents.

Expression of two membrane fusion proteins, synaptosome-associated protein of 25 kDa and vesicle-associated membrane protein, in choroid plexus epithelium.

In addition to being the major site of cerebrospinal fluid formation, the choroid plexus epithelium emerges as an important source of polypeptides in the brain. Physiologically regulated release of some polypeptides synthesized by the choroid plexus has been shown. The molecular mechanisms underlying this polypeptide secretion have not been characterized, however. In the present study, synaptosome-associated protein of 25 kDa and vesicle-associated membrane protein, two membrane fusion proteins playing a critical role in exocytosis in neurons and endocrine cells, were found to be expressed in the choroid plexus epithelium. It was also shown that in choroidal epithelium, synaptosome-associated protein of 25 kDa and vesicle-associated membrane protein stably interact. Two members of the vesicle-associated membrane protein family, vesicle-associated membrane protein-1 and vesicle-associated membrane protein-2, were expressed in the rat choroid plexus at the messenger RNA and protein level. However, their newly discovered isoforms, vesicle-associated membrane protein-1b and vesicle-associated membrane protein-2b, produced by alternative RNA splicing, were not detected in choroidal tissue. Immunohistochemistry demonstrated that vesicle-associated membrane protein is confined to the cytoplasm of choroidal epithelium, whereas synaptosome-associated protein of 25 kDa is associated with plasma membranes, albeit with a varied cellular distribution among species studied. Specifically, in the rat choroid plexus, synaptosome-associated protein of 25 kDa was localized to the basolateral membrane domain of choroidal epithelium and was expressed in small groups of cells. In comparison, in ovine and human choroidal tissues, apical staining for synaptosome-associated protein of 25 kDa was found in the majority of epithelial cells. These species-related differences in cellular synaptosome-associated protein of 25 kDa distribution suggested that the synaptosome-associated protein of 25 kDa homologue, synaptosome-associated protein of 23 kDa, is also expressed in the rat choroid plexus, which was confirmed by reverse-transcriptase polymerase chain reaction. Our findings suggest that synaptosome-associated protein of 25 kDa and vesicle-associated membrane protein are involved in secretion of polypeptides from the choroid plexus epithelium. The presence of synaptosome-associated protein of 25 kDa and its homologue as well as multiple isoforms of vesicle-associated membrane protein in choroidal epithelium may play a role in the apical versus basolateral targeting of secretory vesicles.

Out-of-season breeding of captive white-tailed deer.

Although techniques to induce out-of-season breeding in deer with exogenous hormones are documented, a successful technique has not been developed for use with white-tailed deer (Odocoileus virginianus). The efficacy of using a combined treatment of melatonin, progesterone, and pregnant mare serum gonadotropin to advance seasonal estrus in captive white-tailed deer was tested. First estrus of 12 treated does (n = 16) occurred at least 57 days sooner than did those of 4 non-treated controls (mid-November). Previous estrus dates were known for 11 does, suggesting that their estrus was advanced by 37 to 119 days (X = 82 days). At first estrus, 12 does were bred to untreated bucks that had velvet-covered or recently polished antlers, resulting in a conception rate of 75%. Two does conceived when bred at second or third estrus. Two does failed to conceive when bred at first estrus and displayed no estrous cycling that year, but conceived out-of-season in subsequent years. These data document that this technique is useful for inducing successful, out-of-season breeding of captive white-tailed deer. Furthermore, we demonstrate that some bucks at our facility have adequate fertility and libido to impregnate does during midsummer.

Stag exposure advances the LH surge and behavioral estrus in Eld's deer hinds after CIDR device synchronization of estrus.

The impact of male presence or absence on the timing of the preovulatory LH surge and estrus was studied in 3 experimental groups (n = 6/group) of Eld's deer hinds pretreated with intravaginal progesterone-releasing devices (CIDR-type G) as follows: Group 1 = indirect male contact barn; Group 2 = direct male contact barn; and Group 3 = male isolation barn. For all hinds, the duration of the preovulatory LH surge averaged 2.5+/-0.5 h, whereas mean peak preovulatory and basal LH concentrations were 2.9+/-0.2 ng mL(-1) and 0.27+/-0.03 ng mL(-1), respectively. Nine of 12 male-exposed hinds exhibited a preovulatory LH surge within 24 to 32 h postCIDR device withdrawal, whereas 0 of 6 male-isolated hinds exhibited a preovulatory LH surge during the same time period. Onset of behavioral estrus (45.2+/-2.3, 52.7+/-5.7 and 66.3+/-1.8 h, respectively) was significantly advanced (P<0.05) after CIDR device withdrawal in male exposed hinds (Groups 1 and 2) compared with male isolated hinds (Group 3). These data suggest that stag exposure is important for modulating the timing of the preovulatory LH surge and behavioral estrus after synchronization of estrus with exogenous progestagens.

Robotic automated analysis of foods for aflatoxin.

Immunoaffinity column-based sample preparation procedures for determination of aflatoxins B1, B2, G1, and G2 in several food matrixes and aflatoxin M1 in milk have been automated by using flexible automation, or robotics. Components used to assemble the system were purchased commercially or developed and built in-house. A liquid-level sensor developed in-house to assist elution of the immunoaffinity column is described. After immunoaffinity column cleanup, aflatoxins are separated by reversed-phase liquid chromatography and determined by fluorescence without derivatization. Mean recoveries of aflatoxins B1, B2, and G1 added to corn and nuts at 9-36 ng/g total aflatoxins were > 85% (coefficient of variation [CV] = 16%). Recoveries of aflatoxin G2 averaged 50% (CV = 28%). Recoveries of aflatoxin M1 added to milk at 0.12-0.50 ng/mL averaged 78% (CV = 19%). The ability of the automated system to reproduce its results is demonstrated by the fact that the CV of replicate assays is generally better than 10%. Comparability between the automated procedure and the AOAC official method is demonstrated.

Minimum prevalence of latex hypersensitivity in health care workers.

Health care workers (HCW) have been shown to be at significant risk for developing latex allergy. Natural rubber latex hypersensitivity has been reported in 2.9 to 17% of health care workers in previously published studies. This study describes the prevalence of latex hypersensitivity in a large cohort of medical center employees. A screening questionnaire was distributed to 1967 employees in six job categories exposed to latex, and 1331 questionnaires were returned (68%) between March and November 1995. Skin and serologic testing was performed on 156 volunteers. Of the 1331 HCWs who completed the screening questionnaire, 290 (21.8%) self-reported contact dermatitis to latex, 67 (5.0%) self-reported urticaria to latex, 163 (12.2%) self-reported rhinoconjunctivitis to latex, and 17 (1.3%) self-reported asthmatic symptoms to latex. Of the total population of 1967 employees, 38 (1.9%) were either skin test or blood test positive and 30 (1.5%) of these 38 were symptomatic around latex. This study suggests a minimum prevalence of IgE-mediated hypersensitivity to latex of 1.5% among medical center employees. Our reported prevalence figures are lower than previously reported, reflecting, in part, reporting methods using a denominator more consistent with the total population at risk. Our study also illustrates the pitfall of relying on self-reporting in making the diagnosis of latex allergy.

Putative chemical signals from white-tailed deer (Odocoileus virginianus). Urinary and vaginal mucus volatiles excreted by females during breeding season.

Urine and vaginal mucus samples from female white-tailed deer in estrus and mid-cycle were analyzed by combined gas chromatography-mass spectrometry (GC-MS). Forty-four volatiles were found in mucus and 63 in urine. The volatiles common to both vaginal mucus and urine included alcohols, aldehydes, furans, ketones, alkanes, and alkenes. Aromatic hydrocarbons were present only in the vaginal mucus, whereas pyrans, amines, esters, and phenols were found only in urine. Both estrous mucus and estrous urine could be identified by the presence of specific compounds not present in mid-cycle samples. Numerous compounds exhibited dependency on ovarian hormones.

Electrophysiological measurements of spectral mechanisms in the retinas of two cervids: white-tailed deer (Odocoileus virginianus) and fallow deer (Dama dama).

Electroretinogram (ERG) flicker photometry was used to study the spectral mechanisms in the retinas of white-tailed deer (Odocoileus virginianus) and fallow deer (Dama dama). In addition to having a rod pigment with maximum sensitivity (lambda max) of about 497 nm, both species appear to have two classes of photopic receptors. They share in common a short-wavelength-sensitive cone mechanism having lambda max in the region of 450-460 nm. Each also has a cone having peak sensitivity in the middle wavelengths, but these differ slightly for the two species. In white-tailed deer the lambda max of this cone is about 537 nm; for the fallow deer the average lambda max value for this mechanism was 542 nm. Deer resemble other ungulates and many other types of mammal in having two classes of cone pigment and, thus, the requisite retinal basis for dichromatic color vision.

Volatile compounds from interdigital gland of male white-tailed deer (Odocoileus virginianus).

Interdigital secretions were collected from eight male white-tailed deer of various ages. Analysis of volatiles was performed by gas chromatography-mass spectrometry with a modified headspace technique. Forty-six volatile compounds were found including alkanes, arenes, aldehydes, ketones, aliphatic acids, esters, pyrroles, furans, and sulfur compounds. Eleven occurred in higher concentrations (P≤0.10) in dominant (≥3.5-year-old) than in subordinate (≥1.5-year-old) animals. Dominant males typically have higher serum testosterone levels, and fatty acids and esters fluctuate with sebum production, which is under hormonal control. Therefore, these compounds may reflect testosterone levels and act as chemical signals indicating the presence of a dominant male. Interdigital volatiles also may act as generalized scent trail markers.