2,138 research outputs found
LoCoH: nonparameteric kernel methods for constructing home ranges and utilization distributions.
Parametric kernel methods currently dominate the literature regarding the construction of animal home ranges (HRs) and utilization distributions (UDs). These methods frequently fail to capture the kinds of hard boundaries common to many natural systems. Recently a local convex hull (LoCoH) nonparametric kernel method, which generalizes the minimum convex polygon (MCP) method, was shown to be more appropriate than parametric kernel methods for constructing HRs and UDs, because of its ability to identify hard boundaries (e.g., rivers, cliff edges) and convergence to the true distribution as sample size increases. Here we extend the LoCoH in two ways: "fixed sphere-of-influence," or r-LoCoH (kernels constructed from all points within a fixed radius r of each reference point), and an "adaptive sphere-of-influence," or a-LoCoH (kernels constructed from all points within a radius a such that the distances of all points within the radius to the reference point sum to a value less than or equal to a), and compare them to the original "fixed-number-of-points," or k-LoCoH (all kernels constructed from k-1 nearest neighbors of root points). We also compare these nonparametric LoCoH to parametric kernel methods using manufactured data and data collected from GPS collars on African buffalo in the Kruger National Park, South Africa. Our results demonstrate that LoCoH methods are superior to parametric kernel methods in estimating areas used by animals, excluding unused areas (holes) and, generally, in constructing UDs and HRs arising from the movement of animals influenced by hard boundaries and irregular structures (e.g., rocky outcrops). We also demonstrate that a-LoCoH is generally superior to k- and r-LoCoH (with software for all three methods available at http://locoh.cnr.berkeley.edu)
Depressive Symptoms and Health-Related Quality of Life Among Participants in the Pasos Adelante Chronic Disease Prevention and Control Program, Arizona, 2005-2008
Introduction
Chronic diseases are the leading causes of death in the United States and have been associated with depressive symptoms and poor health-related quality of life (HRQOL). This study examined whether depressive symptoms and HRQOL indicators changed among participants in Pasos Adelante, a chronic disease prevention and control program implemented in a US–Mexico border community.
Methods
Pasos Adelante was a 12-week promotora-led program that included educational sessions and walking groups. We used the Centers for Epidemiologic Studies Depression Scale (CES-D) and the Center for Disease Control’s “Healthy Days” measures to measure depressive symptoms and HRQOL. We used linear mixed-effects models and general estimating equations to analyze changes in CES-D scores and HRQOL indicators from baseline to postprogram and from postprogram to 3-month follow-up.
Results
At baseline, participants had a mean of 7.1 physically unhealthy days, 7.4 mentally unhealthy days, and 3.9 days of activity limitation. The mean number of physically and mentally unhealthy days declined significantly from baseline to postprogram, but the mean number of activity limitation days did not. At baseline, 42.6% of participants reported their health as fair/poor; 20.8% of participants reported frequent mental distress, and 31.8% had a CES-D score of 16 or more. All 3 proportions declined from baseline to postprogram. No significant changes occurred between postprogram and follow-up.
Conclusion
Participants in Pasos Adelante showed improvement in depressive symptoms and several HRQOL indicators. Future studies should use an experimental design with a comparison group to determine whether these findings can be replicated and to examine potential mediators and moderators of program effects
Effectiveness of the Pasos Adelante Chronic Disease Prevention and Control Program in a US-Mexico Border Community, 2005-2008
Introducción
"Pasos Adelante" es un programa de intervención sobre hábitos saludables facilitado por trabajadores de salud comunitaria o"promotores de salud" destinado a prevenir y controlar enfermedades crónicas en mexicoamericanos. Los estudios iniciales de"Pasos Adelante" mostraron mejoras significativas en la alimentación y la actividad física autorreportadas por los participantes.Este estudio evaluó si los habitantes de una comunidad en la frontera estadounidense que participaron en el programa mostraronmejorías en determinados valores fisiológicos y si los cambios se mantuvieron en el seguimiento a los 3 meses.
Métodos
El programa se llevó a cabo en sesiones de 12 semanas de enero del 2005 a mayo del 2008 e incluyó grupos de caminata y clases denutrición y actividad física. Se realizaron cuestionarios, mediciones antropométricas y pruebas de laboratorio al inicio delprograma (n = 305), al final (n = 254) y en el seguimiento a los 3 meses (n = 221).
Resultados
Al compararse los datos iniciales de referencia con los del final del programa, los participantes mostraron reducciones en su índicede masa corporal (P= .04), circunferencia de cintura y cadera (P< .001), presión arterial diastólica y sistólica (P< .001) y colesterol total (P= .008). Ningún valor empeoró significativamente entre la conclusión del programa y el seguimiento, aexcepción de la presión arterial sistólica. Los niveles de glucosa mejoraron entre la finalización y el seguimiento del programa (P=.01).
Conclusión
Estos resultados sustentan los hallazgos iniciales referidos a la mejoría autorreportada por los participantes en relación conpatrones de alimentación y actividad física al mostrar cambios en medidas objetivas. Este programa basado en la evidenciademuestra el potencial de los programas de control y prevención de enfermedades crónicas llevados a cabo por promotores desalud para mejorar la salud física abordando la prevención primaria y secundaria en organizaciones y comunidades hispanas
Depressive Symptoms and Health-Related Quality of Life Among Participants in the Pasos Adelante Chronic Disease Prevention and Control Program, Arizona, 2005-2008
Introduction
Chronic diseases are the leading causes of death in the United States and have been associated with depressive symptoms and poor health-related quality of life (HRQOL). This study examined whether depressive symptoms and HRQOL indicators changed among participants in Pasos Adelante, a chronic disease prevention and control program implemented in a US–Mexico border community.
Methods
Pasos Adelante was a 12-week promotora-led program that included educational sessions and walking groups. We used the Centers for Epidemiologic Studies Depression Scale (CES-D) and the Center for Disease Control’s “Healthy Days” measures to measure depressive symptoms and HRQOL. We used linear mixed-effects models and general estimating equations to analyze changes in CES-D scores and HRQOL indicators from baseline to postprogram and from postprogram to 3-month follow-up.
Results
At baseline, participants had a mean of 7.1 physically unhealthy days, 7.4 mentally unhealthy days, and 3.9 days of activity limitation. The mean number of physically and mentally unhealthy days declined significantly from baseline to postprogram, but the mean number of activity limitation days did not. At baseline, 42.6% of participants reported their health as fair/poor; 20.8% of participants reported frequent mental distress, and 31.8% had a CES-D score of 16 or more. All 3 proportions declined from baseline to postprogram. No significant changes occurred between postprogram and follow-up.
Conclusion
Participants in Pasos Adelante showed improvement in depressive symptoms and several HRQOL indicators. Future studies should use an experimental design with a comparison group to determine whether these findings can be replicated and to examine potential mediators and moderators of program effects
Carbon dioxide activation by a uranium(III) complex derived from a chelating bis(aryloxide) ligand
The new dianionic ligand, C6H4{p-C(CH3)2C6H2Me2O−}2 (= p-Me2bp), featuring two aryloxide donors and a central arene ring, has been synthesized, and used to prepare the mixed-ligand U(III) compound, [U(Cp*)(p-Me2bp)] which exhibits an η6-interaction with the uranium center. Reductive activation of CO2 was investigated using [U(Cp*)(p-Me2bp)] in supercritical CO2, which gave a dinuclear uranium carbonate complex,{U(Cp*)(p-Me2bp)}2(μ-η1:η2-CO3), cleanly and selectively. Reactivity studies in conventional solvents using lower pressures of CO2 showed the formation of a rare U(IV) oxalate complex, {U(Cp*)(p-Me2bp)}2(μ-η2:η2-C2O2), alongside {U(Cp*)(p-Me2bp)}2(μ-η1:η2-CO3). The relative ratio of the latter two products is temperature dependent: at low temperatures (-78 ˚C) oxalate formation is favored, whilst at room temperature the carbonate is the dominant product. The U(IV) iodide, [U(Cp*)(p-Me2bp)I], was also synthesized and used as part of an electrochemical study, the results of which showed that [U(Cp*)(p-Me2bp)] has a UIV/UIII redox couple of −2.18 V vs FeCp2+/0 as well as an possible electrochemically accessible UIII/UII reduction process at −2.56 V vs FeCp2+/0
Rolling Back the Repo Safe Harbors
Recent decades have seen substantial expansion in exemptions from the Bankruptcy Code’s normal operation for repurchase agreements. These repos, which are equivalent to very short-term (often one-day) secured loans, are exempt from core bankruptcy rules such as the automatic stay that enjoins debt collection, rules against prebankruptcy fraudulent transfers, and rules against eve-of-bankruptcy preferential payment to favored creditors over other creditors. While these exemptions can be justified for United States Treasury securities and similarly liquid obligations backed by the full faith and credit of the United States government, they are not justified for mortgage-backed securities and other securities that could prove illiquid or unable to fetch their expected long-run value in a panic. The exemptions from baseline bankruptcy rules facilitate this kind of panic selling and, according to many expert observers, characterized and exacerbated the financial crisis of 2007-2009. The exemptions from normal bankruptcy rules should be limited to United States Treasury and similarly liquid securities, as they once were. The more recent expansion of the exemption to mortgage-backed securities should be reversed
Working memory prioritisation effects in tactile immediate serial recall
There is a growing body of evidence that higher value information can be prioritised for both visual and auditory working memory. The present study examines whether valuable items can similarly be prioritised for the tactile domain. Employing an immediate serial recall procedure (ISR), participants reconstructed a 6-item tactile sequence by moving their fingers in the order of original stimulation. Participants were informed either that one serial position was worth notionally more points (prioritisation condition) or that all items were of equal value (control condition). For Experiment 1 (N=48), significant boosts in correct recall were evident when serial positions 4 or 5 were more valuable (i.e., prioritisation effects). Experiment 2 (N=24) demonstrated that the prioritisation effect persisted with concurrent articulation, suggesting that task performance was not a function of verbal recoding and rehearsal of the tactile information. Importantly, a significant recall cost for low value (non-prioritised) items within the sequence was evident for both experiments. Taken together, these findings demonstrate that (1) prioritisation effects transfer to the tactile domain, and (2) finite attentional resources can be deliberately and strategically redistributed to specific items within a sequence, dependent upon the prevailing task demands
Neutron-Capture Elements in the Early Galaxy: Insights from a Large Sample of Metal-Poor Giants
New abundances for neutron-capture (n-capture) elements in a large sample of
metal-poor giants from the Bond survey are presented. The spectra were acquired
with the KPNO 4-m echelle and coude feed spectrographs, and have been analyzed
using LTE fine-analysis techniques with both line analysis and spectral
synthesis. Abundances of eight n-capture elements (Sr, Y, Zr, Ba, La, Nd, Eu,
Dy) in 43 stars have been derived from blue (lambda = 4070--4710, R~20,000, S/N
ratio~100-200) echelle spectra and red (lambda = 6100--6180, R~22,000, S/N
ratio~100-200) coude spectra, and the abundance of Ba only has been derived
from the red spectra for an additional 27 stars. Overall, the abundances show
clear evidence for a large star-to-star dispersion in the heavy element-to-iron
ratios. The new data also confirm that at metallicities [Fe/H] <~ --2.4, the
abundance pattern of the heavy (Z >= 56) n-capture elements in most giants is
well-matched to a scaled Solar System r-process nucleosynthesis pattern. The
onset of the main r-process can be seen at [Fe/H] ~ --2.9. Contributions from
the s-process can first be seen in some stars with metallicities as low as
[Fe/H] ~ --2.75, and are present in most stars with metallicities [Fe/H] >
--2.3. The lighter n-capture elements (Sr-Y-Zr) are enhanced relative to the
heavier r-process element abundances. Their production cannot be attributed
solely to any combination of the Solar System r- and main s-processes, but
requires a mixture of material from the r-process and from an additional
n-capture process which can operate at early Galactic time.Comment: Text + 5 Tables and 11 Figures: Submitted to the Astrophysical
Journa
1,25(OH)2D3 administration in moderate renal failure: A prospective double-blind trial
1,25(OH)2D3 administration in moderate renal failure: A prospective double blind trial. This study represents the first randomized prospective, double-blind, placebo-controlled trial of the efficacy of 1,25(OH)2D3 on bone histology and serum biochemistry in patients with mild to moderate renal failure. Sixteen patients with chronic renal impairment (creatinine clearance 20 to 59ml per min) received either 1,25(OH)2D3, at a dose of 0.25 to 0.5 µg daily (eight patients), or placebo. Transiliac crest bone biopsies were performed before entrance into the study and after 12 months of experimental observation. None of the patients were symptomatic or had radiological evidence of bone disease. Of the thirteen patients who completed the study, initial serum 1,25(OH)2D levels were low in seven patients and parathyroid hormone levels were elevated in seven patients. Bone histology was abnormal in all patients. 1,25(OH)2D3 treatment was associated with a significant fall in serum phosphorus and alkaline phosphatase concentrations as well as with histological evidence of an amelioration of hyperparathyroid changes. In contrast to previous reports, no deterioration of renal function attributable to the treatment occurred, perhaps because a modest dose of 1,25(OH)2D3 was employed combined with meticulous monitoring. Further investigation is required to determine whether alternative therapeutic strategies (smaller doses or intermittent therapy) may avoid the potential for suppressing bone turnover to abnormally low levels in the long term
Icons: identifying continence options after stroke trial: utility of a logic model in the design and implementation of a process evaluation
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