A mechanism of extreme growth and reliable signaling in sexually selected ornaments and weapons   总被引：1，自引：0，他引：1  

DJ Emlen  IA Warren  A Johns  I Dworkin  LC Lavine 《Science (New York, N.Y.)》2012,337(6096):860-864

Many male animals wield ornaments or weapons of exaggerated proportions. We propose that increased cellular sensitivity to signaling through the insulin/insulin-like growth factor (IGF) pathway may be responsible for the extreme growth of these structures. We document how rhinoceros beetle horns, a sexually selected weapon, are more sensitive to nutrition and more responsive to perturbation of the insulin/IGF pathway than other body structures. We then illustrate how enhanced sensitivity to insulin/IGF signaling in a growing ornament or weapon would cause heightened condition sensitivity and increased variability in expression among individuals--critical properties of reliable signals of male quality. The possibility that reliable signaling arises as a by-product of the growth mechanism may explain why trait exaggeration has evolved so many different times in the context of sexual selection.  相似文献   

Physical Characteristics,Shade Distribution,and Tall Fescue Effects on Cow Temporal/Spatial Distribution in Midwestern Pastures     

Douglas A. Bear  James R. Russell  Daniel G. Morrical 《Strength and Conditioning Journal》2012,65(4):401-408

Nonpoint source (NPS) pollution of water resources may occur from congregation of cattle near streams or ponds. Therefore, relationships of physical characteristics, shade distribution, and tall fescue (Festuca arundinacea Schreb.) prevalence in cool-season grass pastures to the temporal/spatial distribution of grazing cattle were evaluated in two studies on beef cow/calf farms. Global positioning system (GPS) collars recorded the location of 2–3 cows per pasture at 10-min intervals for 5–14 d in the spring, summer, and fall annually. Pasture botanical composition was visually assessed annually. In Study 1, cow location was recorded on five pastures ranging in size from 13 ha to 125 ha with 1.9–3.8% of the pasture area in a stream or pond (water source) and 2–30% of the pasture area within 30.5 m of the water source (waterside zone) for 3 yr. Shade covered 27–73% of the pasture area with 3–64% of shade located within waterside zone. In Study 2, cow location was recorded in three pastures with areas of 8 ha, 10 ha, and 15 ha with 17.8%, 43.4%, and 14.7% of the total area and 28%, 73%, and 68% of the total shade in the waterside zone for 1 yr. In Study 1, proportions of cow observations within the waterside zone increased with decreasing pasture area (r² = 0.61) and increasing proportions of the total pasture area (r² = 0.37) and shade (r² = 0.29) within the waterside zone. In Study 2, proportion of cow observations in the waterside zone increased as the proportion of total area (r² = 0.62) and shade (r² = 0.42) in the waterside zone increased. Results imply more restrictive measures to minimize the risks of NPS pollution of water resources may be most effective in smaller and narrow pastures.  相似文献   

Comparison of hatchery and field performance between a whirling-disease-resistant strain and the Ten Sleep strain of rainbow trout     

Wagner EJ  Bartley M  Arndt R  Oplinger RW  Routledge MD 《Journal of aquatic animal health》2012,24(2):110-120

A whirling-disease-resistant strain of rainbow trout Oncorhynchus mykiss (GRHL strain) derived from a backcross of an F1 hybrid of two strains (German strain x Harrison Lake strain) with German strain females, was compared with the Ten Sleep (TS) strain of rainbow trout. The GRHL strain had consistently superior growth and feed conversion in two consecutive hatchery trials. Hatching and mortality rates were similar between strains. Both strains were stocked into two Utah reservoirs (Hyrum, Porcupine), and a third, Causey Reservoir, was monitored as a control for seasonal variation in prevalence of Myxobolus cerebralis. A total of 1,323 salmonids captured by gill net in spring and fall sampling between 2006 and 2008 were tested for M. cerebralis via pepsin-trypsin digest methods. Only eight of these (< 1% per species) had clinical signs consistent with whirling disease. In both reservoirs, GRHL survived better than the TS and had higher growth rates. The prevalence of M. cerebralis was significantly lower for GRHL (18.1%) than TS (50.0%) in Porcupine Reservoir. In Hyrum Reservoir the trend was similar, but prevalence was lower and did not significantly differ between GRHL (9.6%) and TS (23.1%). For infected fish, no significant differences were observed between strains in myxospore counts in either Hyrum (GRHL = 911-28,244 spores/fish [spf], TS = 1,822-155,800 spf) or Porcupine (GRHL = 333-426,667spf, TS = 333-230,511 spf) reservoirs. Unmarked rainbow trout in both reservoirs had significantly higher myxospore counts than stocked fish of either strain. There were significant differences in M. cerebralis prevalence and myxospore loads among other naturally reproducing salmonids in the reservoirs. The trend in susceptibility was cutthroat trout Oncorhynchus clarkii > kokanee Oncorhynchus nerka > brown trout Salmo trutta. The GRHL performed well in both hatchery and field settings and is recommended for stocking programs.  相似文献   

A life with horses: it's been a great ride!     

Antczak DF 《Veterinary immunology and immunopathology》2012,148(1-2):6-11

In 2010 Doug Antczak was the recipient of the Distinguished Veterinary Immunologist Award of the Veterinary Immunology Committee of the International Union of Immunological Societies. Dr. Antczak is the Dorothy Havemeyer McConville Professor of Equine Medicine at the Baker Institute for Animal Health in the College of Veterinary Medicine at Cornell University. His research focuses on immunological and genetic aspects of the fetal-maternal relationship in the horse. This includes studies of major histocompatibility complex (MHC) genes and molecules, the regulation of their expression in the placenta, the composition and function of uterine lymphocytes, and alterations in maternal immune reactivity during pregnancy. For this research Dr. Antczak developed a herd of purpose-bred horses selected for homozygosity at the MHC. These horses are a unique genetic resource in equine immunology. During his career Dr. Antczak has mentored over 20 graduate students and post-doctoral fellows, many of whom have gone on to independent careers in immunology research. Dr. Antczak has made contributions to equine immunology, genetics, and reproduction, and collaborated widely with scientists in each of these disciplines. Through his relationship with the Havemeyer Foundation, Dr. Antczak has been a catalyst for cooperative research through a series of Havemeyer Foundation Workshops initiated over 25 years ago. Since 1995 he has been a principal participant in the international Horse Genome Project collaboration furthering his equine immunology research through genomic applications. In 2009 Dr. Antczak was inducted into the University of Kentucky's Equine Research Hall of Fame.  相似文献   

Improving bioscience research reporting: the ARRIVE guidelines for reporting animal research     

Kilkenny C  Browne WJ  Cuthi I  Emerson M  Altman DG 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2012,41(1):27-31

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Columbid herpesvirus-1 mortality in great horned owls (Bubo virginianus) from Calgary, Alberta     

Rose N  Warren AL  Whiteside D  Bidulka J  Robinson JH  Illanes O  Brookfield C 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(3):265-268

Four cases of Columbid herpesvirus-1 infection in great horned owls (Bubo virginianus) were identified in Calgary, Alberta. Necropsy findings included severe multifocal hepatic and splenic necrosis, pharyngeal ulceration and necrosis, and gastrointestinal necrosis. Occasional eosinophilic intranuclear viral inclusion bodies were associated with the foci of necrosis and polymerase chain reaction (PCR) testing confirmed a diagnosis of herpesvirus-induced disease. The sequence of a PCR amplicon had 99.7% homology to Columbid herpesvirus-1.  相似文献   

Sixty years of graduating as MsRCVS     

GD Phillips 《The Veterinary record》2012,171(2):52

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Effect of 1-methylcyclopropene (1-MCP) on reducing postharvest decay in tomatoes (Solanum lycopersicum L.)     

Hai SuW. Douglas Gubler 《Postharvest Biology and Technology》2012,64(1):133-137

1-Methylcyclopropene (1-MCP as SmartFresh™ technology), an ethylene antagonist, was evaluated for affecting postharvest decay caused by Alternaria alternata, Botrytis cinerea, and Fusarium spp. on ‘Quality 23’ and ‘Seminis 35’ tomatoes at green or pink stages. Fruit with natural or artificial infection were subjected to 1-MCP at 0.0 μL L⁻¹, 0.6 μL L⁻¹ for 12 h, and 1.0 μL L⁻¹ for 6 h. After 31-42 d storage, disease incidence and severity of individual diseases in 1-MCP treated fruit was significantly reduced compared with that of the untreated controls, except in one inoculated test for ‘Quality 23’ where severity of Alternaria rot in 1.0 μL L⁻¹ treated fruit were significantly higher than that of the untreated control. Fruit treated with 1-MCP at 1.0 L⁻¹ for 6 h also had significantly higher incidence of Alternaria rot in the inoculated ‘Quality 23’ and in the non-inoculated ‘Seminis 35’ compared with the fruit treated with 1-MCP at 0.6 μL L⁻¹ for 12 h. The results of this study indicate that 1-MCP can reduce postharvest decay within a certain storage period.  相似文献   

Reducing bycatch impacts in recreational fisheries: Case study examining terminal tackle in the multispecies Gulf of Maine groundfish fishery     

Connor W. Capizzano  Douglas R. Zemeckis  Emily A. Jones  William S. Hoffman  Micah J. Dean  Matthew H. Ayer  Nate Ribblett  John W. Mandelman 《Fisheries Management and Ecology》2021,28(4):338-350

Terminal tackle regulations can be a valuable tool for fisheries management, especially in multispecies fisheries where bycatch and discards are common issues. In the Gulf of Maine, recreational anglers frequently discard critically depleted Atlantic cod Gadus morhua L. as bycatch when targeting the abundant haddock Melanogrammus aeglefinus (L.) stock. The present study investigated species catch composition, catch rates and animal welfare across various terminal tackle setups, and aspects of capture and handling with the goal of reducing bycatch and discard mortality. Overall, 2558 cod and 4266 haddock were captured with six terminal tackle setups in the western Gulf of Maine from April to October 2018. Along with angler experience and capture depth, lure type primarily influenced species catch composition and catch-per-unit-effort; hook types additionally influenced hook-removal times and physical injuries to fish. Results indicate that using baited hooks can both promote haddock catch and reduce cod bycatch, with specific hook types promoting increased survival.  相似文献   

Metastatic anal sac adenocarcinoma in a dog presenting for acute paralysis          下载免费PDF全文

Brisson BA  Whiteside DP  Holmberg DL 《The Canadian veterinary journal. La revue veterinaire canadienne》2004,45(8):678-681

A 4-year old, female spayed terrier was referred for hind end paresis that rapidly progressed to paralysis. Spinal radiographs revealed vertebral collapse and bony lysis. Myelography confirmed spinal cord compression and surgical exploration found an extradural soft tissue mass. Metastatic anal sac adenocarcinoma was diagnosed at postmortem examination.  相似文献