2,368 research outputs found

    Evaluating susceptibility of red-cockaded woodpecker cavity trees to southern pine beetle in Texas

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    Characteristics of loblolly (Pinus fuedu L.) and shortleaf (Pinus echinutu Mill.) pine trees favored by the endangered red-cockaded woodpecker, Picuides borealis (Vieillot) for nesting and roosting cavities over much of eastern Texas, tend to make these trees highly vulnerable to mortality from bark beetle attack. Resin flow and xylem moisture potential, often used as indicators of pine susceptibility to bark beetle mortality, were measured in several red-cockaded woodpecker cavity tree clusters in the Angelina and Davy Crockett National Forests. No differences in xylem moisture potential were found, while resin flow varied by site, tree species, and cavity tree type. With over half of cavity tree mortality in Texas caused by southern pine beetle, Dendroctonusfrontalis Zimmerman, pro-active management to reduce bark beetle hazard in southern pine stands is imperative

    Stand conditions and tree characteristics affect quality of longleaf pine for red-cockaded woodpecker cavity trees

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    We measured resin flow of longleaf (Pirzus palustris Mill.) pines in red-cockaded woodpecker (Picoides borealis Vieillot) clusters in the Angelina National Forest in Texas, and the Apalachicola National Forest in Florida. Sample trees were categorized as active cavity trees, inactive cavity trees and control trees. Sample trees were further categorized by stand position as either edge or interior trees. Longleaf cavity trees in Texas and Florida had similar resin flow characteristics. Active cavity trees on forest edges had the highest resin flow, whereas active cavity trees in forest interiors had the lowest. Trees experiencing both low and high levels of red-cockaded woodpecker activity and comptition from other trees had low resin flow, whereas intermediate stress typically resulted in high resin flow. Results from this study indicate that the best active red-cockaded woodpecker cavity trees, from a resin flow perspective, are on or near forest edges. This may explain the woodpecker’s observed tendency to excavate new cavities near edges even when interior basal area has been reduced and midstory has been controlled. Our results suggest that pines managed as potential cavity trees should be experiencing minimal competition, and that a mosaic of patches in red-cockaded woodpecker habitat may be preferable to more uniform conditions

    Functional status measures for integrating medical and social care

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    PURPOSE: Identify standard self-report questions about functioning suitable for measuring disability across integrated health and social services. THEORY: Functional activities can be validly grouped according to the International Classification of Functioning, Disability and Health (ICF) chapters of mobility, self-care, and domestic life. METHODS: Cross-sectional analysis using information on 112,601 persons interviewed as part of the United States National Health Interview Survey on Disability. We combined related sets of questions and tested the appropriateness of their groupings through confirmatory factor analyses. Construct validity was addressed by seeking to confirm clinically logical relationships between the resulting functional scales and related health concepts, including number of physician contacts, number of bed days, perception of illness, and perception of disability. RESULTS: Internal consistency for the summed scales ranged from 0.78 to 0.92. Correlations between the functional scales and related concepts ranged from 0.12 to 0.52 in directions consistent with expectations. CONCLUSIONS: Analyses supported the 3 ICF chapters. DISCUSSIONS: The routine collection of this core set of functions could enhance decision-making at the client, professional, organizational, and policy levels encouraging cooperation among the medical and social service sectors when caring for people with disabilities

    Physiology of red-cockaded woodpecker cavity trees: Implications for management

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    Resin flow and tree moisture stress, frequently used as indicators of pine susceptibility to pine bark beetle (Dendroctonus frontalis Zimm.) attack, were measured in loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pines red-cockaded woodpecker [Picoides boreal& (Vieillot)] cavity trees in the Angelina and Davy Crockett National Forests in eastern Texas. No differences in moisture stress were found, whereas resin flow between different types of cavity trees and control or potential trees varied by site and species. It was concluded that effects of red-cockaded woodpecker activity on host tree susceptibility to southern pine beetle will vary by site, tree species, and host tree condition. Forest management activities and general forest health are much more important for the bird’s long-term survival

    Numerical investigation of a two-bladed propeller inflow at yaw

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    The development of faster computing power and nonintrusive experimental techniques has allowed for the advancement in computational fluid dynamics (CFD) validation and the greater understanding of aerodynamic conditions previously deemed too extreme to accurately measure. To this end, a numerical study is conducted that focuses on a propeller at yaw. Current low-order methods are reliant upon an accurate inflow profile to determine overall blade loading patterns. To improve such methods, CFD can be used to determine an initial inflow profile from which to conduct additional lower-order calculations. Therefore, to ensure that CFD is able to accurately capture yawed inflow profiles, a validation study is conducted that compares numerical simulations against experiments. Good agreement is found between the two methods, and subsequently the azimuthal variation in skin friction and induced angle of attack, as a result of the yawed conditions, is analyzed

    Resin Production in Natural and Artificial Red-Cockaded Woodpecker Cavity Trees

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    Resin flow was measured in red-cockaded woodpecker (Picoides borealis Vieillot) clusters in longleaf pine (Pinus palustris Mill.) in the southern region of the Angelina National Forest, Texas. Resin flow (ml) at 1.4 m height over 24 hrs was measured from one 2.5 cm punch through the phloem between 0700 and 1000 hrs from March 1999 to September 2000, for a total of 9 measurements per tree. Resin was sampled in naturally active cavity trees, artificial (insert) active, natural inactive, artificial inactive and control pines (84 sample trees). Resin flow pattern was significantly different during the year, but not significantly different in the cavity tree type resin flow. Cavity trees in the 90th percentile (\u3e33.0 ml resin in 24 hrs) were defined as super resin producing. High average resin flows in August 1999 and September 2000 indicate when to sample resin for potential cavity trees. Regression equations were produced to estimate future resin production

    Red-Cockaded Woodpecker Nest-Cavity Selection: Relationships with Cavity Age and Resin Production

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    ABSTRACT.--We evaluated selection of nest sites by male Red-cockaded Woodpeckers (Picoides borealis) in Texas relative to the age of the cavity when only cavities excavated by the woodpecker were available and when both naturally excavated cavities and artificial cavities we available. We also evaluated nest-cavity selection relative to he ability of naturally excavated cavity trees to produce resin, which is used by the woodpeckers to maintain a barrier against predation by rat snakes (Elaphe spp.), Longleaf pines (Pinus palustris) selected by breeding males as nest trees produced significantly greater resin yields at 2, 8, and 24 h post-wounding than cavity trees used for roosting by other group members. This preference was observed in loblolly pine (P. taeda) and shortleaf pine (P. echinata) cavity trees only at the 2-h resin-sampling period. When only naturally excavated cavities were available. red-cockaded Woodpeckers in both longleaf pine and loblolly-shorleaf pine habitat selected the newest cavities available for their nests sites, possibly as a means to reduce parasites loads. When both naturally excavated and artificial cavity for nesting in loblolly-shortleaf pine habitat, but not in longleaf pine habitat. Resin production in loblolly pine nest trees remained sufficient for continued use, whereas resin production in existing longleaf pine nest trees remained sufficient for continued use, whereas resin production in loblolly pine and shortleaf pine nest trees deceased through time, probably because of woodpecker activity at resin wells. For these latter tree species, breeding males switched to newer cavities and/pr cavity trees with higher resin yields

    Silviculture and the red-cockaded woodpecker: Where do we go from here?

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    Recent standards and guidelines for the protection and management of red-cockaded woodpecker habitat within 3/4 mi of colony sites, and also thinning within colonies to reduce basal area and midstory will have a significant effect on National Forest lands. The relation of these thinnings to forest pest management will be examined as well as the area of forest involved. Current fire regulations in relation to prescribed burns and potential fuel buildup will be examined. Plans for research, including disturbances, hazard, and risk rating for southern pine beetle and landscape changes will be presented

    Evaluation of Novel Imidazotetrazine Analogues Designed to Overcome Temozolomide Resistance and Glioblastoma Regrowth

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    The cellular responses to two new temozolomide (TMZ) analogues, DP68 and DP86, acting against glioblastoma multi- forme (GBM) cell lines and primary culture models are reported. Dose–response analysis of cultured GBM cells revealed that DP68 is more potent than DP86 and TMZ and that DP68 was effective even in cell lines resistant to TMZ. On the basis of a serial neurosphere assay, DP68 inhibits repop- ulation of these cultures at low concentrations. The efficacy of these compounds was independent of MGMT and MMR func- tions. DP68-induced interstrand DNA cross-links were dem- onstrated with H2O2-treated cells. Furthermore, DP68 induced a distinct cell–cycle arrest with accumulation of cells in S phase that is not observed for TMZ. Consistent with this biologic response, DP68 induces a strong DNA damage response, including phosphorylation of ATM, Chk1 and Chk2 kinases, KAP1, and histone variant H2AX. Suppression of FANCD2 expression or ATR expression/kinase activity enhanced anti- glioblastoma effects of DP68. Initial pharmacokinetic analysis revealed rapid elimination of these drugs from serum. Collec- tively, these data demonstrate that DP68 is a novel and potent antiglioblastoma compound that circumvents TMZ resistance, likely as a result of its independence from MGMT and mismatch repair and its capacity to cross-link strands of DN
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