2,928 research outputs found

    Records of \u3ci\u3ePachybrachis\u3c/i\u3e in Illinois (Coleoptera: Chrysomelidae)

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    A list of the 20 species and subspecies of Pachybrachis contained in the collections of the Illinois Natural History Survey and Southern Illinois University, and the author\u27s personal collection, is presented, with recorded ecological data and county distribution records where known

    Key Parameter Comparisons of Fungal Induced Mortality in Alfalfa Weevil Larvae (Coleoptera: Curculionidae)

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    Key parameters of alfalfa weevil larval mortality by Entornophthora phytonorni were compared weekly in three alfalfa fields. Rainfall appeared to be the overriding factor in seasonal larval infection rates

    Influences of Host Density, Temperature, and Parasite Age on the Reproductive Potential of \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae), an Endoparasite of the Alfalfa Weevil (Coleoptera: Curculionidae)

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    Alfalfa weevil larvae were exposed to Bathyplectes curculionis (Thomson) to determine the effect of host density, temperature, and parasite age on the reproductive potential of curculionis. Percent parasitism was found to be inversely proportional to host density and most of the parasites distributed their eggs randomly regardless of host density. The number of eggs deposited was largely independent of temperature. Peak egg laying was reached in three days from which point the parasite\u27s capabilities diminished with increasing age. The longevity of ovipositing females was shorter than females that were not exposed to larvae

    Effect on Constant Versus Fluctuating Temperature Regimes on \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae) Activity

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    Individual female Bathyplectes curculionis parasites were exposed to either a series of constant or fluctuating temperature regimes and supplied with a new group of host Hypera postica larvae every day. The fluctuating temperatures were calculated from an average of weekly air temperatures during a period of actual field oviposition by the parasite. The rearing of adult parasites under a constant versus fluctuating temperature regime resulted in no significant difference in parasitism, longevity, or fecundity. The threshold for B. curculionis activity was estimated to be 6-8°C

    Study of the ammonia ice cloud layer in the north tropical zone of Jupiter from the infrared interferometric experiment on Voyager

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    An average of 51 Voyager 1 IRIS spectra of Jupiter's North Tropical Zone was analyzed to infer the abundance, vertical extent, and size distribution of the particles making up the ammonia cloud in this region. It is assumed that the cloud base coincides with the level at which 100% saturation of ammonia vapor occurs. The vertical distribution of particulates above this level is determined by assuming a constant total ammonia mixing ratio and adjusting the two phases so that the vapor is saturated throughout the cloud. A constant scaling factor then adjusts the base number density. A radiative transfer program is used that includes the effects of absorption and emission of all relevant gases as well as anisotropic scattering by cloud particles. Mie scattering from a gaussian particle size distribution is assumed. The vertical thermal structure is inferred from a temperature retrieval program that utilizes the collision induced S(0) and S(1) molecular hydrogen lines between 300 and 700.cm, and the 1304.cm methane band

    Does Fungal Endophyte Infection Improve Tall Fescue’s Growth Response to Fire and Water Limitation?

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    Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be better-adapted than tall fescue. We hypothesized that tall fescue’s ability to form a symbiosis with Neotyphodium coenophialum, an aboveground fungal endophyte, may enhance its environmental stress tolerance and persistence in these environments. We used a greenhouse experiment to examine the effects of endophyte infection (E+ vs. E−), prescribed fire (1 burn vs. 2 burn vs. unburned control), and watering regime (dry vs. wet) on tall fescue growth. We assessed treatment effects for growth rates and the following response variables: total tiller length, number of tillers recruited during the experiment, number of reproductive tillers, tiller biomass, root biomass, and total biomass. Water regime significantly affected all response variables, with less growth and lower growth rates observed under the dry water regime compared to the wet. The burn treatments significantly affected total tiller length, number of reproductive tillers, total tiller biomass, and total biomass, but treatment differences were not consistent across parameters. Overall, fire seemed to enhance growth. Endophyte status significantly affected total tiller length and tiller biomass, but the effect was opposite what we predicted (E−\u3eE+). The results from our experiment indicated that tall fescue was relatively tolerant of fire, even when combined with dry conditions, and that the fungal endophyte symbiosis was not important in governing this ecological ability. The persistence of tall fescue in native grassland ecosystems may be linked to other endophyte-conferred abilities not measured here (e.g., herbivory release) or may not be related to this plant-microbial symbiosis

    The global energy balance of Titan

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    The global energy budget of planets and their moons is a critical factor to influence the climate change on these objects. Here we report the first measurement of the global emitted power of Titan. Long-term (2004–2010) observations conducted by the Composite Infrared Spectrometer (CIRS) onboard Cassini reveal that the total emitted power by Titan is (2.84 ± 0.01) × 10^(14) watts. Together with previous measurements of the global absorbed solar power of Titan, the CIRS measurements indicate that the global energy budget of Titan is in equilibrium within measurement error. The uncertainty in the absorbed solar energy places an upper limit on the energy imbalance of 6.0%

    The President\u27s Emergency Plan for AIDS Relief (PEPFAR): A Social Work Ethical Analysis and Recommendations

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    The President\u27s Emergency Plan for AIDS Relief (PEPFAR) is the most recent international social program instituted by the U.S. Government to combat HIV/AIDS. Since its inception in 2003, this foreign policy initiative has dedicated $63 billion for HIV/AIDS prevention and treatment in foreign countries. Despite PEPFAR\u27s many accomplishments, it continues to promote controversial prevention strategies. This paper analyzes these prevention strategies, utilizing social work values as described in the NASW Code of Ethics. Policy, practice, and research implications are discussed

    A Public-Domain Personality Item Bank For Use With The Raymark, Schmit, and Guion (1997) PPRF

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    Presented is the development of a repository of work-related personality items that may be used to assess job-related traits identified by the Personality-Related Position Requirements Form (PPRF: Raymark, Schmit, & Guion, 1997). Analyses of the item pool administered to a sample (n = 412) of trade apprentices showed evidence to support the12 work-related Big 5 sub-dimensions identified by the PPRF. A smaller validity study (n = 47) suggested that personality dimensions identified as job-related by the PPRF were related to important job-related outcomes
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