54 research outputs found

    A review of color vision in white-tailed deer

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    A better understanding of the color vision abilities of white-tailed deer (Odocoileus virginianus) helps to determine how these animals interpret their environment. We review and summarize the literature related to the color vision abilities of white-tailed deer. Physiological measurements using advanced techniques such as molecular genetics, electroretinography, and electron microscopy have demonstrated conclusively that whitetailed deer possess the anatomical requisites for color vision. Operant conditioning techniques employed in pen studies using trained cervids confirm that deer see color. The eyes of white-tailed deer are characterized by 3 classes of photopigments: a short-wavelengthsensitive cone mechanism, a middle-wavelength-sensitive cone mechanism, and a short wavelength- sensitive rod pigment. The number and distribution of rod, and cones in the retina, augmented by adaptations of the eye, give white-tailed deer high visual sensitivity and visual acuity in light and darkness. During the day deer discriminate colors in the range blue to yellow-green and can also distinguish longer (orange and red) wavelengths. At night deer see color in the blue to blue-green range, although the moderately wide spectral sensitivity of rods permits some discrimination of longer wavelengths. Rods serve a discriminatory role in color vision, especially at low to moderate illumination levels. Benefits of color vision to deer include the ability to discriminate between plant species and parts and enhanced predator-detection capabilities. This information can be used to define methods of resolving deer-human conflicts and provide insight to deer researchers, photographers, and hunters on how to he more inconspicuous to their subject

    GOPHERUS BERLANDIERI (Texas Tortoise). MORTALITY.

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    MANAGING COMMON NIGHTHAWKS AT MCCONNELL AIR FORCE BASE, KANSAS, TO REDUCE AIRCRAFT STRIKES

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    McConnell Air Force Base (AFB) experiences a unique bird/aircraft hazard problem with migrating common nighthawks from August to October. Nighthawks are the most commonly struck species at McConnell AFB, representing about 38% of reported bird/aircraft strikes. During August and September, nighthawks represented 82% of the bird strikes found on the airfield. Approaches for managing nighthawks on and around airfields are limited because of the night environment, logistics and an incomplete understanding of nighthawk behavior. We determined the number of nighthawks using McConnell AFB and associated foraging, loafing and roosting areas, analyzed their food habits, and developed a translocation management strategy to reduce hazards to aircraft. During 1998, 1999 and 2000, we observed 600, 540 and 920 nighthawks, respectively, on the airfield. The greatest activity on the airfield occurred from September 27-30 in 1998, September 9- 14 in 1999, and September 6-8 in 2000. The peak number of nighthawks observed using the airfield during these periods was 142, 90 and 118, respectively. Nighthawks foraged around the airfield mainly between 1800 and 2200 and usually roosted on the airfield about 1800 with a peak between 2200 and 0200. During one 2-hour survey period in 1999 and 2000, 37 and 59 nighthawks, respectively, were flushed from the airfield. Thirty-seven nighthawks collected during the study consumed mostly corn earworm moths (Noctuidae) and beetles (Scarabaeidae). Management of nighthawks on McConnell AFB has been difficult because commonly used hazing techniques seem to be ineffective; these birds usually return to the same roosting location after being flushed, which can present an even greater risk to aircraft. We developed and evaluated a unique technique for capturing and translocating nighthawks from the airfield. Only 1 of 214 nighthawks translocated 88 km from McConnell AFB returned. Nighthawk/aircraft strikes at McConnell AFB declined from 9 in 1998, when no translocation was conducted, to 0 in 1999 and 3 in 2000

    MANAGING COMMON NIGHTHAWKS AT MCCONNELL AIR FORCE BASE, KANSAS, TO REDUCE AIRCRAFT STRIKES

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    McConnell Air Force Base (AFB) experiences a unique bird/aircraft hazard problem with migrating common nighthawks from August to October. Nighthawks are the most commonly struck species at McConnell AFB, representing about 38% of reported bird/aircraft strikes. During August and September, nighthawks represented 82% of the bird strikes found on the airfield. Approaches for managing nighthawks on and around airfields are limited because of the night environment, logistics and an incomplete understanding of nighthawk behavior. We determined the number of nighthawks using McConnell AFB and associated foraging, loafing and roosting areas, analyzed their food habits, and developed a translocation management strategy to reduce hazards to aircraft. During 1998, 1999 and 2000, we observed 600, 540 and 920 nighthawks, respectively, on the airfield. The greatest activity on the airfield occurred from September 27-30 in 1998, September 9- 14 in 1999, and September 6-8 in 2000. The peak number of nighthawks observed using the airfield during these periods was 142, 90 and 118, respectively. Nighthawks foraged around the airfield mainly between 1800 and 2200 and usually roosted on the airfield about 1800 with a peak between 2200 and 0200. During one 2-hour survey period in 1999 and 2000, 37 and 59 nighthawks, respectively, were flushed from the airfield. Thirty-seven nighthawks collected during the study consumed mostly corn earworm moths (Noctuidae) and beetles (Scarabaeidae). Management of nighthawks on McConnell AFB has been difficult because commonly used hazing techniques seem to be ineffective; these birds usually return to the same roosting location after being flushed, which can present an even greater risk to aircraft. We developed and evaluated a unique technique for capturing and translocating nighthawks from the airfield. Only 1 of 214 nighthawks translocated 88 km from McConnell AFB returned. Nighthawk/aircraft strikes at McConnell AFB declined from 9 in 1998, when no translocation was conducted, to 0 in 1999 and 3 in 2000

    Monitoring coyote population changes with a passive activity index

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    A passive tracking index method that has been successfully applied to dingoes (Canis lupus dingo) in Australia was shown to have more general applicability to wild canids by monitoring coyote (Canis latrans) populations in southern Texas. The index was calculated simultaneously for multiple species of animals from observations on the number of intrusions onto a series of tracking plots over several days. We found that the index reflected changes in coyote activity before and after a trapping program on each of 2 ranches. We also were able to simultaneously monitor bobcat (Felis rufus) and white-tailed deer (Odocoileus virginianus) populations, producing some interesting (and unexpected) insights. In our study area, we found it difficult to distinguish the number of rabbit and rodent intrusions into the plots, but these animals might be indexed in other habitats. Analyses of the data as binary responses (presence or absence of spoor on each tracking plot), as has been done in scent-post surveys, reduced the sensitivity and accuracy of inferences

    Plot placement when using a passive tracking index to simultaneously monitor multiple species of animals

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    We evaluated a passive tracking index (PTI) when plots were placed on lightly used dirt roads versus placement on naturally occurring bare ground in natural habitat. PTIs were calculated before and after removal of coyotes and some non-target species during another study that evaluated capture devices. Six mammals were simultaneously monitored with the PTI: coyotes, raccoons, white-tailed deer, feral swine, javelina, and rabbits. PTIs from road plots were significantly higher than from off-road plots, except for deer and javelina, for which no differences were detected. After removal of coyotes, PTIs were significantly lower, both from on- and off-road plots. For coyotes and raccoons, the decline in index values primarily reflected population reductions. For animals hunted for sport (deer, swine, javelina), population reductions were minor compared with coyotes, and their declines in index values likely reflected conditioned responses to the activity and shooting that accompanied evaluations of the capture devices. We conclude that the PTI is sensitive to changes in population or changes in activity in response to an event for a variety of species, and it is most useful when placed on lightly used dirt roads

    A retinoblastoma allele that is mutated at its common E2F interaction site inhibits cell proliferation in gene-targeted mice

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    The retinoblastoma protein (pRB) is best known for regulating cell proliferation through E2F transcription factors. In this report, we investigate the properties of a targeted mutation that disrupts pRB interactions with the transactivation domain of E2Fs. Mice that carry this mutation endogenously (Rb1δG) are defective for pRB-dependent repression of E2F target genes. Except for an accelerated entry into S phase in response to serum stimulation, cell cycle regulation in Rb1δG/δG mouse embryonic fibroblasts (MEFs) strongly resembles that of the wild type. In a serum deprivation-induced cell cycle exit, Rb1δG/δG MEFs display a magnitude of E2F target gene derepression similar to that of Rb1-/- cells, even though Rb1δG/δG cells exit the cell cycle normally. Interestingly, cell cycle arrest in Rb1δG/δG MEFs is responsive to p16 expression and gamma irradiation, indicating that alternate mechanisms can be activated in G1 to arrest proliferation. Some Rb1δG/δG mice die neonatally with a muscle degeneration phenotype, while the others live a normal life span with no evidence of spontaneous tumor formation. Most tissues appear histologically normal while being accompanied by derepression of pRB-regulated E2F targets. This suggests that non- E2F-, pRB-dependent pathways may have a more relevant role in proliferative control than previously identified. © 2014, American Society for Microbiology

    Characterization of highly frequent epitope-specific CD45RA(+)/CCR7(+/- )T lymphocyte responses against p53-binding domains of the human polyomavirus BK large tumor antigen in HLA-A*0201+ BKV-seropositive donors

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    Human polyomavirus BK (BKV) has been implicated in oncogenic transformation. Its ability to replicate is determined by the binding of its large tumor antigen (LTag) to products of tumor-suppressor genes regulating cell cycle, as specifically p53. We investigated CD8+ T immune responses to BKV LTag portions involved in p53 binding in HLA-A*0201+ BKV LTag experienced individuals. Peptides selected from either p53-binding region (LTag(351–450 )and LTag(533–626)) by current algorithms and capacity to bind HLA-A*0201 molecule were used to stimulate CD8+ T responses, as assessed by IFN-γ gene expression ex vivo and detected by cytotoxicity assays following in vitro culture. We observed epitope-specific immune responses in all HLA-A*0201+ BKV LTag experienced individuals tested. At least one epitope, LTag(579–587); LLLIWFRPV, was naturally processed in non professional antigen presenting cells and induced cytotoxic responses with CTL precursor frequencies in the order of 1/20'000. Antigen specific CD8+ T cells were only detectable in the CD45RA+ subset, in both CCR7+ and CCR7- subpopulations. These data indicate that widespread cellular immune responses against epitopes within BKV LTag-p53 binding regions exist and question their roles in immunosurveillance against tumors possibly associated with BKV infection

    Discovery of a New Human Polyomavirus Associated with Trichodysplasia Spinulosa in an Immunocompromized Patient

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    The Polyomaviridae constitute a family of small DNA viruses infecting a variety of hosts. In humans, polyomaviruses can cause infections of the central nervous system, urinary tract, skin, and possibly the respiratory tract. Here we report the identification of a new human polyomavirus in plucked facial spines of a heart transplant patient with trichodysplasia spinulosa, a rare skin disease exclusively seen in immunocompromized patients. The trichodysplasia spinulosa-associated polyomavirus (TSV) genome was amplified through rolling-circle amplification and consists of a 5232-nucleotide circular DNA organized similarly to known polyomaviruses. Two putative “early” (small and large T antigen) and three putative “late” (VP1, VP2, VP3) genes were identified. The TSV large T antigen contains several domains (e.g. J-domain) and motifs (e.g. HPDKGG, pRb family-binding, zinc finger) described for other polyomaviruses and potentially involved in cellular transformation. Phylogenetic analysis revealed a close relationship of TSV with the Bornean orangutan polyomavirus and, more distantly, the Merkel cell polyomavirus that is found integrated in Merkel cell carcinomas of the skin. The presence of TSV in the affected patient's skin was confirmed by newly designed quantitative TSV-specific PCR, indicative of a viral load of 105 copies per cell. After topical cidofovir treatment, the lesions largely resolved coinciding with a reduction in TSV load. PCR screening demonstrated a 4% prevalence of TSV in an unrelated group of immunosuppressed transplant recipients without apparent disease. In conclusion, a new human polyomavirus was discovered and identified as the possible cause of trichodysplasia spinulosa in immunocompromized patients. The presence of TSV also in clinically unaffected individuals suggests frequent virus transmission causing subclinical, probably latent infections. Further studies have to reveal the impact of TSV infection in relation to other populations and diseases
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