10,482 research outputs found

    Responses of the Ocellated Turkey (Meleagris ocellata) to Human Disturbance

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    Habitat loss and habitat degradation are major drivers of the current biodiversity crisis. Nowhere else are these threats more severe than in the tropics. Because the tropics are estimated to contain as much as 60% of all the species on Earth, they are critically important for the conservation of biodiversity. To conserve species we need to understand both the factors that lead to extinction and how the taxa that persist are able to adapt to the rapid anthropogenic change of their environment. The Ocellated Turkey (Meleagris ocellata) is a Neotropical galliform bird of conservation concern because it faces a rapidly changing environment. The goal of this thesis is two fold: 1) to expand our understanding of the natural history of the Ocellated Turkey (Meleagris ocellata), and 2) to document the behavioral responses of this species to different levels of anthropogenic habitat modification. Chapter One describes a radiotelemetry study of adult males. This investigation is the first published record of the home range use and movement patterns of adult males of this species during the breeding season. These birds shohome ranges that were highly variable in size and composition (MCP x ?x= 969 ± 922 ha, 95%FK x ?x= 692 ± 819 ha, 50%FK x ?x= 90 ± 138 ha). In comparison to other similarly sized Galliformes, the Ocellated Turkey home range is quite large. The average movement rate also varied greatly between individuals (x ?x= 437 ± 264 m/h). A few individuals restricted their movements to intact forest only, while others spent all day in open pasture. The majority of radiotagged males (7 of 12) spent 50% or more of their time in areas without closed canopy cover. Chapter Two describes the association of habitat disturbance with male movement patterns and select indicators of health. There were no significant differences in home range size, blood and fecal parasites, feather barring regularity, male fleshy ornaments, and H:L ratios among the disturbance types. Additionally, most of the feather reflectance data did not significantly differ between disturbance levels (low, intermediate, and high), but I did find differences in the blue ocelli of the secondary tail coverts among disturbance levels. The dominant ultraviolet spectrum hue of the ocelli were negatively correlated with coccidian parasite load but the dominant red spectrum hue was positively correlated with this parasite. Chapter Three presents various results from the field study that further our knowledge of the natural history of this species, including an analysis of flocking behavior, fecal parasite distribution at the landscape level, and notes on predator inspection behavior, the submission display of non-breeding males and their early attempts at courtship. Flocks were larger and sholess vigilance in open habitat but did not have a different foraging there compared to flocks in the forest. Mapping of the number of parasites found in feces identified “hot spots” with high concentrations of parasites, which surprisingly included a shade coffee grove. Young males used the double wing turn behavior to deflect aggression from alpha males. Incomplete action patterns for gobbling and strutting were observed in young male flocks. The results of this study suggest that a matrix of rainforest and cattle pasture is not harmful to Oocellated Tturkey health, although further studies that include measures of survivorship and fecundity are needed to model accurately this species’ population viability in an anthropogenic environment

    In pursuit of causality in leadership training research: A review and pragmatic recommendations

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    Although research shows a reliable association between leadership training and positive organizational outcomes, a range of research design issues mean we do not know to what degree the former causes the later. Accordingly, the paper has two main aims. First, to describe the conditions necessary to determine causality in leadership training research and the ability of different research designs to achieve this. Six important, but often ignored, issues associated with determining causality are described (control conditions, sample representation, condition randomization, condition independence, temporal design, and author involvement). Second, to review the extent to which the leadership training literature is able to demonstrate causality. The review shows that the majority of studies do not meet many of the criteria, even the most basic criteria, required to establish causality. Finally, we provide guidelines for designing future research to improve causal identification and is capable of generating meaningful theory and policy recommendations

    The Clinical Frailty Scale can be used retrospectively to assess the frailty of patients with hip fracture:a validation study

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    PURPOSE: Frailty is a common clinical syndrome affecting hip fracture patients. Recognising and accurately assessing frailty status is important in clinical and research settings. The Rockwood Clinical Frailty Scale (CFS) is a commonly used instrument and demonstrates a strong correlation with mortality and length of hospital admission following hip fracture. What is not understood, however, is the validity of retrospectively assigned CFS scores in hip fracture patients. The aim of this study was to assess the validity of retrospective non-orthogeriatrician assigned CFS scores in hip fracture patients. METHODS: Hip fracture patients from a single major trauma centre were assessed and CFS scores were assigned prospectively by non-orthogeriatric clinicians (n = 57). A subset of these patients were also assigned a prospective CFS score by a specialist orthogeriatrician (n = 27). Two separate blinded observers (non-orthogeriatric clinicians) assigned CFS scores retrospectively using electronic patient records alone. Agreement and precision was examined using the Bland–Altman plot, accuracy was assessed using R(2) statistic and inter-rater reliability was assessed using quadratic weighted Cohen’s kappa. RESULTS: Seventy percent of the cohort were female with an average age of 83. Agreement was high between prospective non-orthogeriatrician assigned CFS scores and retrospective non-orthogeriatrician assigned CFS scores, with a low bias (0.046) and good accuracy (R(2) = 73%). Good agreement was also seen in comparisons between prospective orthogeriatrician assigned CFS scores versus retrospective non-orthogeriatrician assigned scores, with a low bias (0.23) and good accuracy (R(2) = 78%). Good inter-rater reliability was seen between blinded observers with a quadratic weighted Cohen’s kappa of 0.76. CONCLUSIONS: Retrospective CFS scores assigned by non-orthogeriatricians are a valid means of assessing frailty status in hip fracture patients. However, our results suggest a tendency for non-orthogeriatricians to marginally overestimate frailty status when assigning CFS scores retrospectively. LEVEL OF EVIDENCE: 3

    Development of antigen-specific ELISA for circulating autoantibodies to extracellular matrix protein 1 in lichen sclerosus

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    Lichen sclerosus is a common, acquired chronic inflammatory skin disease of unknown etiology, although circulating autoantibodies to the glycoprotein extracellular matrix protein 1 (ECM1) have been detected in most patients’ sera. We have examined the nature of ECM1 epitopes in lichen sclerosus sera, developed an ELISA system for serologic diagnosis, and assessed clinicopathological correlation between ELISA titer and disease. Epitope-mapping studies revealed that lichen sclerosus sera most frequently recognized the distal second tandem repeat domain and carboxyl-terminus of ECM1. We analyzed serum autoantibody reactivity against this immunodominant epitope in 413 individuals (95 subjects with lichen sclerosus, 161 normal control subjects, and 157 subjects with other autoimmune basement membrane or sclerosing diseases). The ELISA assay was highly sensitive; 76 of 95 lichen sclerosus patients (80.0%) exhibited IgG reactivity. It was also highly specific (93.7%) in discriminating between lichen sclerosus and other disease/control sera. Higher anti-ECM1 titers also correlated with more longstanding and refractory disease and cases complicated by squamous cell carcinoma. Furthermore, passive transfer of affinity-purified patient IgG reproduced some histologic and immunopathologic features of lichen sclerosus skin. This new ELISA is valuable for the accurate detection and quantification of anti-ECM1 autoantibodies. Moreover, the values may have clinical significance in patients with lichen sclerosus

    Rate of telomere shortening and cardiovascular damage: a longitudinal study in the 1946 British Birth Cohort.

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    AIM: Cross-sectional studies reported associations between short leucocyte telomere length (LTL) and measures of vascular and cardiac damage. However, the contribution of LTL dynamics to the age-related process of cardiovascular (CV) remodelling remains unknown. In this study, we explored whether the rate of LTL shortening can predict CV phenotypes over 10-year follow-up and the influence of established CV risk factors on this relationship. METHODS AND RESULTS: All the participants from the MRC National Survey of Health and Development (NSHD) with measures of LTL and traditional CV risk factors at 53 and 60-64 years and common carotid intima-media thickness (cIMT), cardiac mass and left ventricular function at 60-64 years were included. LTL was measured by real-time polymerase chain reaction and available at both time points in 1033 individuals. While LTL at 53 years was not linked with any CV phenotype at 60-64 years, a negative association was found between LTL and cIMT at 60-64 years (β = -0.017, P = 0.015). However, the strongest association was found between rate of telomere shortening between 53 and 60-64 years and values of cIMT at 60-64 years (β = -0.020, P = 0.006). This association was not affected by adjustment for traditional CV risk factors. Cardiac measurements were not associated with cross-sectional or longitudinal measures of LTL. CONCLUSION: These findings suggest that the rate of progression of cellular ageing in late midlife (reflected by the rate of LTL attrition) relates to vascular damage, independently from contribution of CV risk factor exposure

    Using Self-Monitoring to Increase Following-Direction Skills of Students with Moderate to Severe Disabilities in General Education

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    We used two multiple baseline designs to investigate effects of a self-monitoring strategy on following-direction skills of six middle school students with moderate to severe disabilities in general education. Students were instructed to acknowledge a given direction, complete the task, and monitor their performance. Results suggest that all students learned the strategy and maintained their performance at mastery levels for the duration of the maintenance condition. Social validation data obtained from participating general and special educators supported these findings. Implications for promoting student-directed learning and inclusive education are discussed. © Division on Developmental Disabilities

    No Far-Infrared-Spectroscopic Gap in Clean and Dirty High-TC_C Superconductors

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    We report far infrared transmission measurements on single crystal samples derived from Bi2_{2}Sr2_{2}CaCu2_{2}O8_{8}. The impurity scattering rate of the samples was varied by electron-beam irradiation, 50MeV 16^{16}O+6^{+6} ion irradiation, heat treatment in vacuum, and Y doping. Although substantial changes in the infrared spectra were produced, in no case was a feature observed that could be associated with the superconducting energy gap. These results all but rule out ``clean limit'' explanations for the absence of the spectroscopic gap in this material, and provide evidence that the superconductivity in Bi2_{2}Sr2_{2}CaCu2_{2}O8_{8} is gapless.Comment: 4 pages and 3 postscript figures attached. REVTEX v3.0. Accepted for publication in Phys. Rev. Lett. IRDIRT

    Electrochemical activation of molecular nitrogen at the Ir/YSZ interface.

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    Nitrogen is often used as an inert background atmosphere in solid state studies of electrode and reaction kinetics, of solid state studies of transport phenomena, and in applications e.g. solid oxide fuel cells (SOFC), sensors and membranes. Thus, chemical and electrochemical reactions of oxides related to or with dinitrogen are not supposed and in general not considered. We demonstrate by a steady state electrochemical polarisation experiments complemented with in situphotoelectron spectroscopy (XPS) that at a temperature of 450 °C dinitrogen can be electrochemically activated at the three phase boundary between N2, a metal microelectrode and one of the most widely used solid oxide electrolytes—yttria stabilized zirconia (YSZ)—at potentials more negative than E = −1.25 V. The process is neither related to a reduction of the electrolyte nor to an adsorption process or a purely chemical reaction but is electrochemical in nature. Only at potentials more negative than E = −2 V did new components of Zr 3d and Y 3d signals with a lower formal charge appear, thus indicating electrochemical reduction of the electrolyte matrix. Theoretical model calculations suggest the presence of anionic intermediates with delocalized electrons at the electrode/electrolyte reaction interface. The ex situSIMS analysis confirmed that nitrogen is incorporated and migrates into the electrolyte beneath the electrode

    Antifungal prophylaxis in chemotherapy-associated neutropenia: a retrospective, observational study

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    <p>Abstract</p> <p>Background</p> <p>In August 2002, the antifungal prophylaxis algorithm for neutropenic hematology/oncology (NHO) patients at the Medical Center was changed from conventional amphotericin (AMB) to an azole (AZ) based regimen (fluconazole [FLU] in low-risk and voriconazole [VOR] in high-risk patients). The aim of our study was to compare outcomes associated with the two regimens, including breakthrough fungal infection, adverse drug events, and costs.</p> <p>Methods</p> <p>Adult, non-febrile, NHO patients who received prophylactic AMB from 8/01/01-7/30/02 or AZ from 8/01/02-7/30/03 were retrospectively evaluated.</p> <p>Results</p> <p>A total of 370 patients (AMB: n = 181; AZ: n = 216) associated with 580 hospitalizations (AMB: n = 259; AZ: n = 321) were included. The incidence of probable/definite breakthrough Aspergillus infections was similar among regimens (AMB: 1.9% vs AZ: 0.6%; p=0.19). A greater incidence of mild/moderate (24.7% vs. 5.3%; p < 0.0001) and severe renal dysfunction (13.5% vs. 4.4%; p < 0.0012) was observed with AMB. In contrast, patients treated with VOR were found to have an increased rate of severe hepatic toxicity (32.5%) compared with patients treated with either AMB (22.6%) or FLU (21.4%) (p = 0.05). While the AZ period was associated with a >9,000increaseinmeantotalcosts/hospitalization,themeanacquisitioncostassociatedwithAZwasonly9,000 increase in mean total costs/hospitalization, the mean acquisition cost associated with AZ was only 947/hospitalization more than AMB.</p> <p>Conclusion</p> <p>While an AZ-based regimen is associated with increased cost, the reduced rate of nephrotoxicity and availability of oral dosage forms, suggests that azoles be used preferentially over AMB. However, an increased rate of severe hepatic toxicity may be associated with VOR.</p
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