2,728 research outputs found
The Effects of Social Stress on Voluntary Running Behavior in Female Mice
Regular physical activity (PA) positively impacts physical and mental health outcomes. However, there is a reciprocal relationship wherein stress significantly reduces healthy levels of routine PA. We showed previously that voluntary running behavior of male mice essentially ceases following exposure to a resident-intruder social stress. Here we examined female mice. Female mice were divided into four groups (n=8/group): sedentary/control, voluntary running/control, sedentary/stress, and voluntary running/stress. Running groups were given unlimited access to a running wheel in the home cage for 9 weeks with a nightly average of 6.86 ± 2.5 km. During the ninth week, stress groups were exposed to a single, 6-hour bout of a female-specific, resident-intruder social stress. Plasma corticosterone significantly increased following stress (34.56 ± 13 ng/ml basal to 330.5 ± 95 ng/ml immediately post-stress). Nightly running dropped significantly to 1.72 ± 0.9 km. Unlike male mice where running levels were slow to recover, voluntary running in these female mice returned to normal levels by the second night (5.01 ± 2.5 km). This study shows the sensitivity of habitual running behavior to stress exposure and suggests the utility of this mouse model in exploring the means by which stress negatively impacts routine PA
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Development of an Integrated Governance Strategy for the Voluntary and Community Sector
This report on governance provides a framework for thinking about how policy makers, funders,regulators and advisers can all work with Board members and staff to enhance the effectiveness of nonprofit organisations. It was commissioned by the Active Community Unit (ACU) of the Home Office, in parallel with other reviews designed to improve the capacity of the voluntary and community sector, at a time when the sector plays an increasingly important role in the delivery of services using public funds. That role has recently been investigated in two Government reports, the Cross Cutting Review carried out by the Treasury, and the Strategy Unit review of charities and nonprofits. Our report proposes actions of three types: some that can be taken immediately, some that require further discussion with key interests, and some integration with the other ACU reviews. Taken together they provide the starting point for an evolving strategy to improve governance across the sector. We recommend ACU chairs a group charged with the responsibility for planning and implementing this. Our focus is on governance as 'the systems and processes concerned with ensuring the overall direction, supervision and accountability of an organisation'. This is often taken to mean the way that a Board, management committee or other governing body steers the overall development of an organisation, where day-to-day management is in the hands of staff or volunteers. Sometimes, of course, the committee and volunteers are the same. They – like all governing bodies – have to balance the interests of the organisation and those they are trying to serve, while being conscious of financial and legal responsibilities, and the requirements of funders and other supporters
STEREO and Wind Observations of Intense Cyclotron Harmonic Waves at the Earth's Bow Shock and Inside the Magnetosheath
We present the first observations of electron cyclotron harmonic waves at the Earth's bow shock from STEREO and Wind burst waveform captures. These waves are observed at magnetic field gradients at a variety of shock geometries ranging from quasi-parallel to nearly perpendicular along with whistler mode waves, ion acoustic waves, and electrostatic solitary waves. Large amplitude cyclotron harmonic waveforms are also observed in the magnetosheath in association with magnetic field gradients convected past the bow shock. Amplitudes of the cyclotron harmonic waves range from a few tens to more than 500 millivolts/meter peak-peak. A comparison between the short (15 meters) and long (100 meters) Wind spin plane antennas shows a similar response at low harmonics and a stronger response on the short antenna at higher harmonics. This indicates that wavelengths are not significantly larger than 100 meters, consistent with the electron cyclotron radius. Waveforms are broadband and polarizations are distinctively comma-shaped with significant power both perpendicular and parallel to the magnetic field. Harmonics tend to be more prominent in the perpendicular directions. These observations indicate that the waves consist of a combination of perpendicular Bernstein waves and field-aligned waves without harmonics. A likely source is the electron cyclotron drift instability which is a coupling between Bernstein and ion acoustic waves. These waves are the most common type of high-frequency wave seen by STEREO during bow shock crossings and magnetosheath traversals and our observations suggest that they are an important component of the high-frequency turbulent spectrum in these regions
THE DEVELOPMENT OF HIGH PLASTICITY CLAY SOILS THROUGH WEATHERING OF DEVONIAN SLATES IN SOUTH DEVON
Cattell, A.C. 1998. The development of high plasticity clay soils through weathering of Devonian slates in south Devon. Geoscience in south-west England, 9, 209-213. Clay-rich subsoils are developed from Devonian slates across south Devon. Weathering of the slate causes a progressive disaggregation to silty clay, with little change in the clay mineralogy. Although the clay size fraction (and hence plasticity) of individual soil samples varies with the degree of breakdown of slate clasts, the plasticity of completely weathered material is controlled by the mineralogy of the parent slate. Soils on Lower Devonian slates almost all have low to intermediate plasticity, those developed on Upper Devonian slates have intermediate to high plasticity, whilst very high plasticities soils only occur on Middle Devonian slates. These types are geographically widespread: Upper Devonian purple slates in Plymouth and Newton Abbot produce indistinguishable soils 40 km apart, and pale yellow high plasticity soils are developed on Middle Devonian slates in Torquay, Dartington and Plympton. Previous work has shown that most slates, including Middle Devonian, have the clay assemblage illite + chlorite +/-kaolinite. New data presented here show that the highest plasticity soils are restricted to particular Middle Devonian slates which have low Fe and Mg and high Al, and consequently have the assemblage illite + kaolinite. The non-chloritic slate unit is widespread but its extent remains to be determined. A.C.Cattell, Rodney Broom Associates
Observation of a westward travelling surge from satellites at low, medium and high altitudes
The motion of discontinuity; electric potential and current structure of the event; energy source and flow; wave-particle interactions; and particle acceleration are addressed using wave, electron, ion mass spectrometer, dc electric field, and magnetic field observation from the Isee-1, NOAA-6, and the 1976-059 geostationary satellite
The spherical probe electric field and wave experiment
The experiment is designed to measure the electric field and density fluctuations with sampling rates up to 40,000 samples/sec. The description includes Langmuir sweeps that can be made to determine the electron density and temperature, the study of nonlinear processes that result in acceleration of plasma, and the analysis of large scale phenomena where all four spacecraft are needed
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