6,417 research outputs found

    Variation in Loblolly Pine Cross-Sectional Microfibril Angle With Tree Height and Physiographic Region

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    The effect of height and physiographic region on whole disk cross-sectional microfibril angle (CSMFA) in loblolly pine (Pinus taeda L.) in the southern United States was evaluated. Whole disk CSMFA was determined at 1.4, 4.6, 7.6, 10.7, and 13.7 m up the stem of 59 trees, representing five physiographic regions. A mixed-effects analysis of variance was performed to test the significance of height, region, and the height by region interaction on CSMFA. Height, region, and the height by region interaction terms were all found to be significant at the 0.10 level. Significant differences were found in CSMFA between 1.4 m and all other height levels in all regions. However, there was no difference between CSMFA at 1.4 m and 13.7 m in the Gulf Coastal Plain. No significant difference was found in CSMFA between 4.5, 7.6, and 10.7 meter-height levels in all regions. CSMFA was found to be significantly larger in the north Atlantic and Piedmont regions compared to the south Atlantic, Gulf, and Hilly regions at all heights. The analysis of variance also indicated that significant variation exists among trees within stands and across stands within regions. This is an indicator that aside from the distinct patterns of CSMFA within trees, other factors including site quality, length of growing season, rainfall, and genetics could possibly play a key role in CSMFA development

    Variation in Loblolly Pine Ring Microfibril Angle in the Southeastern United States

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    The effect of physiographic region on microfibril angle (MFA) in loblolly pine (Pinus taeda L.) in the southern United States was evaluated. MFA was determined at 1.4, 4.6, 7.6, 10.7, and 13.7 m up the stem of 59 trees, representing five physiographic regions. A nonlinear mixed-effects model was developed to test for regional differences in the initial value of MFA, the rate at which MFA changes with ring number from pith, and the lower bound of MFA achieved. Our results suggest that the parameters of interest differ significantly by region. It was found that MFA differs significantly between the South Atlantic, Gulf, and Hilly regions, compared to the North Atlantic and Piedmont regions. The initial value of MFA was found to be smaller in the Piedmont compared to all other regions. Similarly, the rate at which MFA changes with ring number was found to be significantly smaller in the North Atlantic and Piedmont regions. A test of the lower bound of MFA indicates that the Piedmont region has a significantly larger lower asymptote. These results combined indicate that overall, MFA values are larger in the North Atlantic and Piedmont regions

    Visions in monochrome: Families, marriage and the individualisation thesis

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    This paper takes issue with the way in which the individualisation thesis – in which it is assumed that close relationships have become tenuous and fragile - has become so dominant in ‘new’ sociological theorising about family life. Although others have criticised this thesis, in this paper the main criticism derives from empirical research findings carried out with members of transnational families living in Britain whose values and practices do not fit easily with ideas of individualisation. It is argued that we need a much more complex and less linear notion of how families change across generations and in time

    Advancing Equity In The Pandemic Treaty

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    There is a broad consensus around equity’s importance. Even countries that hoarded supplies during the acute phase of COVID-19 seem to understand that the international community must find a means to ensure fairer allocation of medical resources when the next health crisis hits. But there has been little agreement about the concrete steps needed to operationalize fairer access and benefit sharing. That is, what are the workable mechanisms that could reduce the divide between richer and poorer populations? The World Health Assembly, the governing body of the World Health Organization, has appointed an Intergovernmental Negotiating Body to develop a pandemic convention, agreement, or other instrument under the WHO constitution. The February 2023 draft is designed “to achieve greater equity 
 through the fullest national and international cooperation.” It is important that the negotiators develop specific, measurable metrics that directly impact equity. The mechanisms and metrics agreed upon should allow the public to evaluate whether a more equitable system is emerging through this new regime. Equity won’t just happen. We need to plan and prepare for equity, and we need international norms with which nations must comply to achieve the fairness we strive for

    Cultural Orientations of sport managers

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    Various interpretations of sport management are cultural constructs underpinned by core assumptions and values held by members of professional communities. Sport managers world wide share common problems, but differ in how they resolve them. These universal differences emerge from the relationships they form with other people, and their attitude to time, activities and the natural environment. This paper examines the role of sport managers’ cultural orientations in the interpretation and practice of sport management. Using a multiple dimension model (Hampden-Turner and Trompenaars, 2000) it sketches the cultural profiles of fifteen sport managers from seven countries. A combination of methods was employed including questionnaires, interviews and participant observation. It is contended that the culture of sport management concerns a social process by which managers get involved in reconciling seven fundamental cultural dilemmas in order to perform tasks and achieve certain ends. Thus, a knowledge of the cultural meaning of sport management in a particular country would equip sport managers with a valuable tool in managing both the cultural diversity of their own work forces and in developing appropriate cross-cultural skills needed for running international events, marketing campaigns, sponsorship deals and joint ventures

    Correlated variability of Mkn 421 at X-ray and TeV wavelengths on timescales of hours

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    Mkn 421 was observed for about two days with BeppoSAX, prior to and partly overlapping the start of a 1 week continuous exposure with ASCA in April 1998, as part of a world-wide multiwavelength campaign. A pronounced, well defined, flare observed in X-rays was also observed simultaneously at TeV energies by the Whipple Observatory's 10 m gamma-ray telescope. These data provide the first evidence that the X-ray and TeV intensities are well correlated on time-scales of hours.Comment: 4 pages, 1 figure, presented at the VERITAS Workshop on the TeV Astrophysics of Extragalactic Object

    Search for TeV Gamma-Rays from Shell-Type Supernova Remnants

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    If cosmic rays with energies <100 TeV originate in the galaxy and are accelerated in shock waves in shell-type supernova remnants (SNRs), gamma-rays will be produced as the result of proton and electron interactions with the local interstellar medium, and by inverse Compton emission from electrons scattering soft photon fields. We report on observations of two supernova remnants with the Whipple Observatory's 10 m gamma-ray telescope. No significant detections have been made and upper limits on the >500 GeV flux are reported. Non-thermal X-ray emission detected from one of these remnants (Cassiopeia A) has been interpreted as synchrotron emission from electrons in the ambient magnetic fields. Gamma-ray emission detected from the Monoceros/Rosette Nebula region has been interpreted as evidence of cosmic-ray acceleration. We interpret our results in the context of these observations.Comment: 4 pages, 2 figures, to appear in the proceedings of 26th International Cosmic Ray Conference (Salt Lake City, 1999
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