614 research outputs found

    Demonstration of Sex Pheromones in \u3ci\u3eMolanna Uniophila\u3c/i\u3e (Trichoptera: Molannidae), \u3ci\u3ePlatycentropus Radiatus, Pycnopsyche Indiana, and P. Subfasciata\u3c/i\u3e (Trichoptera: Limnephilidae), With an Assessment of Interspecific Attraction Between Four Sympatric \u3ci\u3ePycnopsyche\u3c/i\u3e Species

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    Evidence for sex pheromones in the caddisflies Molanna uniophila Vorhies, Platycentropus radiatus (Say), Pycnopsyche indiana (Ross), and P. subfasciata (Say) is presented here for the first time based on field studies conducted in southern Michigan. For all species, numbers of males caught in pheromone traps baited with conspecific female extracts were higher than those caught in traps with male extracts, or those without extract. Four sympatric species of Pycnopsyche: P. guttifer (Walker), P. indiana, P. lepida (Hagen), and P. subfasciata exhibited no interspecific pheromonal attraction despite a common mating season and, in the case of P. indiana and P. lepida, very similar genitalic morphology. Our results suggest the importance of pheromones in maintaining reproductive isolation between closely related species. Likewise, pheromone biology can help delineate morphologically cryptic species

    The pioneer projects: Economical exploration of the solar system

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    The interplanetary Pioneer missions are reviewed in terms of management implications and cost control. The responsibilities, organizational structure, and management practices of the Pioneer Projects are presented. The lines of authority and areas of responsibility of the principal organizational elements supporting the Pioneer missions are identified, and the methods employed for maintaining effective and timely interactions among these elements are indicated. The technical and administrative functions of the various organizational elements of the Pioneer Project Office at Ames Research Center are described in terms of their management responsibilities and interactions with other elements of the Project Office and with external organizations having Pioneer Project responsibilities. The management and control of activities prior to and during the hardware procurement phase are described to indicate the basis for obtaining visibility of the technical progress, utilization of resources, and cost performance of the contractors and other institutions supporting the Pioneer projects

    Demonstration of Sex Pheromones in \u3ci\u3eMolanna Uniophila\u3c/i\u3e (Trichoptera: Molannidae), \u3ci\u3ePlatycentropus Radiatus, Pycnopsyche Indiana, and P. Subfasciata\u3c/i\u3e (Trichoptera: Limnephilidae), With an Assessment of Interspecific Attraction Between Four Sympatric \u3ci\u3ePycnopsyche\u3c/i\u3e Species

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    Evidence for sex pheromones in the caddisflies Molanna uniophila Vorhies, Platycentropus radiatus (Say), Pycnopsyche indiana (Ross), and P. subfasciata (Say) is presented here for the first time based on field studies conducted in southern Michigan. For all species, numbers of males caught in pheromone traps baited with conspecific female extracts were higher than those caught in traps with male extracts, or those without extract. Four sympatric species of Pycnopsyche: P. guttifer (Walker), P. indiana, P. lepida (Hagen), and P. subfasciata exhibited no interspecific pheromonal attraction despite a common mating season and, in the case of P. indiana and P. lepida, very similar genitalic morphology. Our results suggest the importance of pheromones in maintaining reproductive isolation between closely related species. Likewise, pheromone biology can help delineate morphologically cryptic species

    The effect of local wind on seismic noise near 1 Hz at the MELT site and in Iceland

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    The mantle electromagnetic and tomography (MELT) experiment on the east Pacific rise near 17°S was the first large teleseismic experiment on a midocean ridge. During the six-month deployment, no compressional arrivals were well recorded above 0.5 Hz. In comparison, the ICEMELT experiment in Iceland recorded compressional arrivals at 1-2 Hz from about 2 earthquakes per month. We compare noise spectra from the two experiments and show that this difference in detection is at least in part a result of noise. Near 1 Hz, seismic noise in the oceans is produced locally by wind-generated waves. At both experiment sites, 1-Hz noise levels are well correlated with local sea-surface-wind speeds derived from satellite observations. For a given wind speed, 1-Hz noise levels are about 10-20 dB lower in Iceland. At the MELT site, cross-correlations of wind speed with the logarithm of noise in a narrow-frequency band yield correlation coefficients exceeding 0.7 at frequencies between 0.4 Hz and 2 Hz. Noise levels at 1 Hz increase with wind by 1.3-1.4 dB per m/sec for wind speeds less than 10 m/sec. For the ICEMELT experiment, high correlation coefficients extend to markedly higher frequencies for coastal stations, and there is a 10-dB drop in 1-Hz noise levels 100-km inland. Noise levels increase by about 0.8 dB per m/sec. The strong correlation between wind speed and l-Hz seismic noise provides justification for using satellite wind speed data to search for locations on the global spreading system where there is a better probability of recording high-frequency arrivals. The calmest sites are found on the northern east Pacific rise, near the equator in all oceans, and near 34 ° N and 22 ° S on the mid- Atlantic ridge.This study was supported by the National Science Foundation under grant OCE-9414299.Peer Reviewe

    Radiotelemetry systems for measuring body temperature

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    End of Project ReportThe objective of this study was to compare three methods of measuring body temperature in the bovine and examine their relationship with ambient temperature. The three methods used were (a) rumen bolus (b) tympanic logger and (c) rectal

    Post Eruption inflation of the East Pacific Rise at 9°50′ N

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    In June 2008, we installed a geodetic network at 9°50′ N on the East Pacific Rise to track the long‐term movement of magma following the 2005/6 eruption. This network consists of 10 concrete benchmarks stretching from the ridge to 9 km off‐axis. During three campaign‐style surveys, measurements of vertical seafloor motions were made at each of these benchmarks by precisely recording ambient seawater pressure as a proxy for seafloor depth with a mobile pressure recorder (MPR). The MPR was deployed using the manned submersible Alvin in 2008 and 2009 and the remotely operated vehicle Jason in 2011. The MPR observations are supplemented with data from a multiyear deployment of continuously recording bottom pressure recorders (BPRs) extending along this segment of the ridge that can record rapid changes in seafloor depth from seafloor eruptions and/or dike intrusions. These measurements show no diking events and up to 12 cm of volcanic inflation that occurred from December 2009 to October 2011 in the area of the 2005/6 eruption. These observations are fit with an inflating point source at a depth of 2.7 km and volume change of 2.3 × 106 m3/yr located on the ridge axis at approximately 9°51.166′ N, 407 m from our northernmost benchmark, suggesting that the magma chamber underlying this segment of the ridge is being recharged from a deeper source at a rate that is about half the long‐term inflation rate observed at Axial Seamount on the Juan de Fuca Ridge. These data represent the second location that active volcanic uplift has been measured on a mid‐ocean ridge segment, and the first on a nonhotspot influenced segment
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