1,020 research outputs found

    Eurasian watermilfoil biomass associated with insect herbivores in New York

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    A study of aquatic plant biomass within Cayuga Lake, New York spans twelve years from 1987-1998. The exotic Eurasian watermilfoil ( Myriophyllum spicatum L.) decreased in the northwest end of the lake from 55% of the total biomass in 1987 to 0.4% in 1998 and within the southwest end from 50% in 1987 to 11% in 1998. Concurrent with the watermilfoil decline was the resurgence of native species of submersed macrophytes. During this time we recorded for the first time in Cayuga Lake two herbivorous insect species: the aquatic moth Acentria ephemerella , first observed in 1991, and the aquatic weevil Euhrychiopsis lecontei , first found in 1996 . Densities of Acentria in southwest Cayuga Lake averaged 1.04 individuals per apical meristem of Eurasian watermilfoil for the three-year period 1996-1998. These same meristems had Euhrychiopsis densities on average of only 0.02 individuals per apical meristem over the same three-year period. A comparison of herbivore densities and lake sizes from five lakes in 1997 shows that Acentria densities correlate positively with lake surface area and mean depth, while Euhrychiopsis densities correlate negatively with lake surface area and mean depth. In these five lakes, Acentria densities correlate negatively with percent composition and dry mass of watermilfoil. However, Euhrychiopsis densities correlate positively with percent composition and dry mass of watermilfoil. Finally, Acentria densities correlate negatively with Euhrychiopsis densities suggesting interspecific competition

    Comparison of DMSP cross-track ion drifts and SuperDARN line-of-sight velocities

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    Cross-track ion drifts measured by the DMSP satellites are compared with line-of-sight SuperDARN HF velocities in approximately the same directions. Good overall agreement is found for a data set comprising of 209 satellite passes over the field of view of nine SuperDARN radars in both the Northern and Southern Hemispheres. The slope of the best linear fit line relating the SuperDARN and DMSP velocities is of the order of 0.7 with a tendency for SuperDARN velocities to be smaller. The agreement implies that the satellite and radar data can be merged into a common set provided that spatial and temporal variations of the velocity as measured by both instruments are smooth.<br><br> <b>Keywords.</b> Ionosphere (Ionospheric irregularities; Plasma convection; Auroral ionosphere

    A statistical comparison of the AMIE derived and DMSP‐SSIES observed high‐latitude ionospheric electric field

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95462/1/jgra18089.pd

    Development of a Comprehensive New 4-H Extension Agents Training Program Using a Multi-Module Approach and the 4-H Professional Research, Knowledge, and Competencies (4HPRKC) Taxonomy

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    Following significant budget reductions in 2002, Virginia Cooperative Extension explored strategies to meet the professional development needs of new 4-H Extension faculty and staff. The Department of 4-H Youth Development created a training program to teach youth development competencies consistent with the national 4-H professional research, knowledge, and competencies (4HPRKC) taxonomy. Written and verbal evaluations from participants in the New 4-H Extension Agents Training Program suggested that the training was informative, interactive, and responsive to participants\u27 needs. This program is a potential model for other Extension programs that serve the professional development needs of new 4-H Extension faculty and staf

    ANESTESIA: La anestesia con pentotal en obstetricia

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    Conjugate observations of the day-side reconnection electric field: A GEM boundary layer campaign

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    How prisoners and their partners experience the maintenance of their relationship during a prison sentence

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    Research shows that intimate relationships, and their maintenance via prison visits, have a positive impact on factors associated with prisoner well‐being and reduced likelihood of recidivism. It is therefore in the interest of corrections, government, and wider society to enable prisoners to maintain healthy relationships with their family and intimate partners throughout their prison sentence. Despite this evidence, little is known about how prisoners experience the maintenance of a significant intimate relationship in prison. This study aims to explore heterosexual couples' experiences in maintaining their well‐established intimate relationships, while the male partner is incarcerated. Four main themes were identified: how they experienced “having a special connection” that they were motivated to maintain; “coping with challenges and threats” to that connection; “developing reciprocal behaviours” to meet those challenges; and “maintaining a belief in the future.” Implications for how the relational context of rehabilitation can best be supported is considered

    Response of reverse convection to fast IMF transitions

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    The nature of the transition that high‐latitude reverse convection makes in response to fast interplanetary magnetic field (IMF) changes is investigated using observations from multiple spacecraft and a ground magnetometer array. We focused on two fast IMF‐transition events on 22 April 2006. Immediately after the first event, three ST5 spacecraft identified a clear change in the distribution of the polar cap field‐aligned current. Coordinate observations with the Greenland magnetometer chain showed that the near‐noon Hall current distribution, which is closely related to the polar cap field‐aligned current or reverse convection, was in a transition state for about 10 min. For the second event, the Greenland magnetic perturbations also showed that a transition state occurred in the near‐noon sector for 10–15 min. Three DMSP spacecraft that traversed the polar cap provided evidence showing that variations of the ground magnetic perturbations were produced by the transition from clockwise plasma circulation to the anticlockwise circulation over the polar cap. A simple calculation based on the Biot‐Savart law shows that the near‐noon transition state is consistent with the approach of a new convection region to the near‐noon sector at the speed of 0.5–1 km s–1, which is coupled with the moving away of the old convection region at a similar speed. For the higher‐latitude sunward flow region, it is found that the convection takes a transition state almost simultaneously (within 1 min) with that in the near‐noon sector, i.e., quasi‐instantaneous response.Key PointsTransition state with a timescale of ~10 min in the near‐noon polar cap for BZ > 0The state is consistent with the passage of old and new convection regionsAlmost simultaneous initial response in the upstream polar cap and the near noonPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111947/1/jgra51794.pd

    Healthier prisons: The role of a prison visitors' centre

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    Since the inception of the prison as a ‘setting’ for health promotion, there has been a focus on how the health of those men and women who spend ‘time inside’ can at least be maintained and if possible, enhanced, during their prison sentence. This paper presents findings from a mainly qualitative evaluation of a prison visitors' centre in the UK. It reports experiences of prisoners' families, prisoners, prison staff, the local community and the ways in which the visitors' centre has contributed positively to their health and well-being. In addition, key stakeholders were interviewed to ascertain the role this visitors' centre has in policy frameworks related to re-offending. The findings from this evaluation underscore how the visitors' centre improved the quality of visits, and contributed towards the maintenance of family ties through the help and support it provides for families and prisoners. The paper concludes by suggesting that visitors' centres are an essential part of a modern prison service helping to address the government's health inequalities agenda
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