69 research outputs found

    Survival Rates for Northern Bobwhites on Two Areas with Different Levels of Harvest

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    We estimated survival rates for radio-marked northern bobwhites ( Colinus virginianus) in south-central Iowa from I 984 to I 988. Survival rates and survival functions were calculated for 2 areas that received different and varied amounts of hunting pressure. Survival from fall-spring averaged 17.1 % ± 6.9% on the Brown\u27s Slough study area (BSSA) and 20.1 % ± 5.7% on the Millerton study area (MSA). Although these estimates were not different (P = 0.898), the survival functions did differ between the 2 areas (x2 = 25.82, P\u3c0.001). Mortality due to hunting averaged 27.7% ± 8.2% on the BSSA during the fall-spring period and 12.3% ± 4.9% on the MSA. Predators accounted for 52% of fall-spring mortality on the BSSA and 79% of the mortality on the MSA. The BSSA had much lower rates of predation the 2 months following the hunting season. Survival rates during both the spring-fall period and annually did not differ between the 2 areas (P = 0.395 and P = 0.979). Hunting did not appear to be a limiting factor for quail numbers on these areas during the study

    Survival Rates of Northern Bobwhite Chicks in South-Central Iowa

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    We estimated survival rates for radio-tagged northern bobwhite quail chicks (Colinus virginianus) in south-central Iowa from 1986 to 1988. Survival rates and survival functions were calculated for chicks from broods raised by females, broods raised by males and from broods that did not have an adult associated with them. Survival functions differed between broods with hens and those without adults. Predators accounted for almost all of the observed mortality

    A Review of the Bounty System as a Method of Controlling Undesirable Animal Populations in Houston County, Minnesota (1883-1965)

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    The bounty system has been in effect for 82 years in Houston County, Minnesota. Over $170,000 in bounties have been paid during that time for wolves, foxes, rattlesnakes, pocket gophers, striped gophers, woodchucks, and crows. Over 7,000 rattlesnakes have been bountied in a single year. A family of semi-professional bounty hunters collected 2,511 rattlesnakes in one year. With the possible exception of wolves, the bounty system has had little apparent effect in controlling animal populations in Houston County. Habitat change has been primarily responsible for the decrease in numbers of wolves and for the rapid increase in numbers of red fox and deer

    Breeding Strategies of the Northern Bobwhite in Marginal Habitat

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    We studied nesting behavior of radio-tagged northern bobwhite (Colinus virginianus) in south-central Iowa from 1984 to 1988. Female bobwhite incubated 78% of81 clutches where incubation was observed and males incubated 22%. On only 1 occasion were both a male and female observed to incubate the same clutch. Incubation was initiated on 73% of the nests by females before 1 July, while incubation was initiated on 56% of the clutches by males after 1 July. Males hatched 16% of all clutches, first nests by females accounted for 69%, renests for 4%, and second clutches by females that had already hatched 1 clutch for 11 %. Chicks from 3 of the first broods of females that hatched ~l brood survived for ~l week and were not accompanied by other adults. These breeding strategies appear to provide bobwhite populations multiple chances at recruitment in variable environments

    Results of the August Roadside Survey for Upland Wildlife in Iowa: 1963-1988

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    Results of the August roadside survey collected from 1963 through 1988 were examined to determine if trends could be detected in the counts of ring-necked pheasants (Phasianus colchicus), northern bobwhite (Colinus virginianus), gray partridge (Perdix perdix), cottontail rabbits (Sylvilagus floridanus), and white-tailed jackrabbits (Lepus townsendii). The counts also were compared to harvest estimates co determine if correlations exist. Statistically significant linear trends were detected statewide for pheasants, gray partridge and jackrabbits during the 1963 co 1988 period. Trends were downward for all species except gray partridge. During the late 12 years (1977 through 1988), the only significant trend detected was for gray partridge, where counts increased. The survey results also were examined for trends on a regional basis where possible. Significant correlations were found between the mean counts and harvest for all species. For cottontails, however, chis relationship appears to have changed as the correlation of the counts with harvest since 1977 is near zero

    Thermodynamic pathways to genome spatial organization in the cell nucleus

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    The architecture of the eukaryotic genome is characterized by a high degree of spatial organization. Chromosomes occupy preferred territories correlated to their state of activity and, yet, displace their genes to interact with remote sites in complex patterns requiring the orchestration of a huge number of DNA loci and molecular regulators. Far from random, this organization serves crucial functional purposes, but its governing principles remain elusive. By computer simulations of a Statistical Mechanics model, we show how architectural patterns spontaneously arise from the physical interaction between soluble binding molecules and chromosomes via collective thermodynamics mechanisms. Chromosomes colocalize, loops and territories form and find their relative positions as stable hermodynamic states. These are selected by “thermodynamic switches” which are regulated by concentrations/affinity of soluble mediators and by number/location of their attachment sites along chromosomes. Our “thermodynamic switch model” of nuclear architecture, thus, explains on quantitative grounds how well known cell strategies of upregulation of DNA binding proteins or modification of chromatin structure can dynamically shape the organization of the nucleus

    Percolation transition of hydration water at hydrophilic surfaces

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    An analysis of water clustering is used to study the quasi-2D percolation transition of water adsorbed at planar hydrophilic surfaces. Above the critical temperature of the layering transition (quasi-2D liquid-vapor phase transition of adsorbed molecules) a percolation transition occurs at some threshold surface coverage, which increases with increasing temperature. The location of the percolation line is consistent with the existence of a percolation transition at the critical point. The percolation threshold at a planar surface is weakly sensitive to the size of the system when its lateral dimension increases from 80 to 150 A. The size distribution of the largest water cluster shows a specific two-peaks structure in a wide range of surface coverage : the lower- and higher-size peaks represent contributions from non-spanning and spanning clusters, respectively. The ratio of the average sizes of spanning and non-spanning largest clusters is about 1.8 for all studied planes. The two-peak structure becomes more pronounced with decreasing size of the planar surface and strongly enhances at spherical surfaces.Comment: 17 pages, 11 figure

    EduSex: Charlas de eeducación sexual para jovenes

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    Seminario Desarrollo de Emprendedores. 2013. Carrera Medicina .Propuesta de empresa dedicada a promover la educación sexual en jóvenes a través de seminarios informativos. El público meta son todos los jóvenes estudiantes de la Universidad Americana, sin importar su facultad o área de estudio. Se espera que los seminarios sean llevados a cabo en el Auditorio Central del campus universitario UAM, bajo la coordinación de Vida Estudiantil. Además, los seminarios son liderados por un experto en el tema sexólogo del Hospital Bertha Calderón Roque. El objetivo de la empresa es difundir conocimiento científico sobre sexualidad para disminuir las infecciones de Transmisión Sexual y la tasa de embarazos no deseados

    Study of the pd3HeK+Kpd\to ^3\textrm{He} K^+K^- and pd3Heϕpd\to ^3\textrm{He} \phi reactions close to threshold

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    Two--kaon production in proton--deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final 3^3He and a vertex detector to measure the K+KK^+K^- pair. Differential and total cross sections are presented for the production of ϕ\phi--mesons, decaying through ϕK+K\phi\to K^+K^-, as well as for prompt K+KK^+K^- production. The prompt production seems to follow phase space in both its differential distributions and in its energy dependence. The amplitude for the pd3pd\to ^3{He}ϕ \phi reaction varies little for excess energies below 22 MeV and the value is consistent with that obtained from a threshold measurement. The angular distribution of the K+KK^+K^- decay pair shows that near threshold the ϕ\phi--mesons are dominantly produced with polarization m=0m=0 along the initial proton direction. No conclusive evidence for f0(980)f_0(980) production is found in the data.Comment: 13 figure
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