747 research outputs found

    Bulletin No. 345 - Effectiveness of Gravity Drains and Experimental Pumping for Drainage Delta Area, Utah

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    Cooperatie investigations on drainage and reclamation of salted soils in the Delta Area, Utah, were undertaken by the Utah Agricultural Experiment Station, the U. S. Regional Salinity Laboratory, and Millard County Drainage Districts under a memorandum of understanding effective January 1, 1946. This investigation comprises project 250 of the Utah Agricultural Experiment Station, R. H. Walker, director; and project 50-46-1 of the U. S. Regional Salinity Laboratory, H. E. Hayward, director. The objectives of the investigations covered by the memorandum of understanding were: 1. To study the effectiveness of present methods of drainage; tile and open drains. 2. To determine the possibilities of pumping from wells as a method of drainage in the Delta Area and the possibility of using the pumped water for irrigation. 3. To determine practical and economical methods of reclaiming unproductive saline and alkali soils of the area by leaching. The leaching phase of these investigations has been completed and the results are reported in Experiment Station Bulletin 335 entitled Reclamation of saline-alkali soils by leaching. The first and second \u27phases concerned with the effectiveness of present drainage methods and the possibilities of pumping for drainage are included in this report. Drainage and leaching are inseparable and must be considered as integral parts of an overall reclamation program for areas in which salinity is a problem

    Spectral quantification of nonlinear behaviour of the nearshore seabed and correlations with potential forcings at Duck, N.C., U.S.A

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    Local bathymetric quasi-periodic patterns of oscillation are identified from monthly profile surveys taken at two shore-perpendicular transects at the USACE field research facility in Duck, North Carolina, USA, spanning 24.5 years and covering the swash and surf zones. The chosen transects are the two furthest (north and south) from the pier located at the study site. Research at Duck has traditionally focused on one or more of these transects as the effects of the pier are least at these locations. The patterns are identified using singular spectrum analysis (SSA). Possible correlations with potential forcing mechanisms are discussed by 1) doing an SSA with same parameter settings to independently identify the quasi-periodic cycles embedded within three potentially linked sequences: monthly wave heights (MWH), monthly mean water levels (MWL) and the large scale atmospheric index known as the North Atlantic Oscillation (NAO) and 2) comparing the patterns within MWH, MWL and NAO to the local bathymetric patterns. The results agree well with previous patterns identified using wavelets and confirm the highly nonstationary behaviour of beach levels at Duck; the discussion of potential correlations with hydrodynamic and atmospheric phenomena is a new contribution. The study is then extended to all measured bathymetric profiles, covering an area of 1100m (alongshore) by 440m (cross-shore), to 1) analyse linear correlations between the bathymetry and the potential forcings using multivariate empirical orthogonal functions (MEOF) and linear correlation analysis and 2) identify which collective quasi-periodic bathymetric patterns are correlated with those within MWH, MWL or NAO, based on a (nonlinear) multichannel singular spectrum analysis (MSSA). (...continued in submitted paper)Comment: 50 pages, 3 tables, 8 figure

    Boundary critical behavior at m-axial Lifshitz points for a boundary plane parallel to the modulation axes

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    The critical behavior of semi-infinite dd-dimensional systems with nn-component order parameter ϕ\bm{\phi} and short-range interactions is investigated at an mm-axial bulk Lifshitz point whose wave-vector instability is isotropic in an mm-dimensional subspace of Rd\mathbb{R}^d. The associated mm modulation axes are presumed to be parallel to the surface, where 0md10\le m\le d-1. An appropriate semi-infinite ϕ4|\bm{\phi}|^4 model representing the corresponding universality classes of surface critical behavior is introduced. It is shown that the usual O(n) symmetric boundary term ϕ2\propto \bm{\phi}^2 of the Hamiltonian must be supplemented by one of the form λ˚α=1m(ϕ/xα)2\mathring{\lambda} \sum_{\alpha=1}^m(\partial\bm{\phi}/\partial x_\alpha)^2 involving a dimensionless (renormalized) coupling constant λ\lambda. The implied boundary conditions are given, and the general form of the field-theoretic renormalization of the model below the upper critical dimension d(m)=4+m/2d^*(m)=4+{m}/{2} is clarified. Fixed points describing the ordinary, special, and extraordinary transitions are identified and shown to be located at a nontrivial value λ\lambda^* if ϵd(m)d>0\epsilon\equiv d^*(m)-d>0. The surface critical exponents of the ordinary transition are determined to second order in ϵ\epsilon. Extrapolations of these ϵ\epsilon expansions yield values of these exponents for d=3d=3 in good agreement with recent Monte Carlo results for the case of a uniaxial (m=1m=1) Lifshitz point. The scaling dimension of the surface energy density is shown to be given exactly by d+m(θ1)d+m (\theta-1), where θ=νl4/νl2\theta=\nu_{l4}/\nu_{l2} is the anisotropy exponent.Comment: revtex4, 31 pages with eps-files for figures, uses texdraw to generate some graphs; to appear in PRB; v2: some references and additional remarks added, labeling in figure 1 and some typos correcte

    Assessing health and well-being among older people in rural South Africa

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    Background: The population in developing countries is ageing, which is likely to increase the burden of noncommunicable diseases and disability. Objective: To describe factors associated with self-reported health, disability and quality of life (QoL) of older people in the rural northeast of South Africa. Design: Cross-sectional survey of 6,206 individuals aged 50 and over. We used multivariate analysis to examine relationships between demographic variables and measures of self-reported health (Health Status), functional ability (WHODASi) and quality of life (WHOQoL). Results: About 4,085 of 6,206 people eligible (65.8%) completed the interview. Women (Odds Ratio (OR) 1.30, 95% CI 1.09, 1.55), older age (OR2.59, 95% CI 1.97, 3.40), lower education (OR1.62, 95% CI 1.31,2.00), single status (OR1.18, 95% CI 1.01, 1.37) and not working at present (OR1.29, 95% CI 1.06, 1.59) were associated with a low health status. Women were also more likely to report a higher level of disability (OR1.38, 95% CI 1.14, 1.66), as were older people (OR2.92, 95% CI 2.25, 3.78), those with no education (OR1.57, 95% CI 1.26, 1.97), with single status (OR1.25, 95% CI 1.06, 1.46) and not working at present (OR1.33, 95% CI 1.06, 1.66). Older age (OR1.35, 95% CI 1.06, 1.74), no education (OR1.39, 95% CI 1.11, 1.73), single status (OR1.28, 95% CI 1.10, 1.49), a low household asset score (OR1.52, 95% CI 1.19, 1.94) and not working at present (OR1.32; 95% CI 1.07, 1.64) were all associated with lower quality of life. Conclusions: This study presents the first population-based data from South Africa on health status, functional ability and quality of life among older people. Health and social services will need to be restructured to provide effective care for older people living in rural South Africa with impaired functionality and other health problems

    Identification of features of electronic prescribing systems to support quality and safety in primary care using a modified Delphi process

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    <p>Abstract</p> <p>Background</p> <p>Electronic prescribing is increasingly being used in primary care and in hospitals. Studies on the effects of e-prescribing systems have found evidence for both benefit and harm. The aim of this study was to identify features of e-prescribing software systems that support patient safety and quality of care and that are useful to the clinician and the patient, with a focus on improving the quality use of medicines.</p> <p>Methods</p> <p>Software features were identified by a literature review, key informants and an expert group. A modified Delphi process was used with a 12-member multidisciplinary expert group to reach consensus on the expected impact of the features in four domains: patient safety, quality of care, usefulness to the clinician and usefulness to the patient. The setting was electronic prescribing in general practice in Australia.</p> <p>Results</p> <p>A list of 114 software features was developed. Most of the features relate to the recording and use of patient data, the medication selection process, prescribing decision support, monitoring drug therapy and clinical reports. The expert group rated 78 of the features (68%) as likely to have a high positive impact in at least one domain, 36 features (32%) as medium impact, and none as low or negative impact. Twenty seven features were rated as high positive impact across 3 or 4 domains including patient safety and quality of care. Ten features were considered "aspirational" because of a lack of agreed standards and/or suitable knowledge bases.</p> <p>Conclusions</p> <p>This study defines features of e-prescribing software systems that are expected to support safety and quality, especially in relation to prescribing and use of medicines in general practice. The features could be used to develop software standards, and could be adapted if necessary for use in other settings and countries.</p

    Getting into hot water:sick guppies frequent warmer thermal conditions

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    Ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. They may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. This adaptive response, known as ‘behavioural fever’, has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. Here, a choice chamber experiment was used to investigate the thermal preferences of a tropical freshwater fish, the Trinidadian guppy (Poecilia reticulata), when infected with a common helminth ectoparasite Gyrodactylus turnbulli, in female-only and mixed-sex shoals. The temperature tolerance of G. turnbulli was also investigated by monitoring parasite population trajectories on guppies maintained at a continuous 18, 24 or 32 °C. Regardless of shoal composition, infected fish frequented the 32 °C choice chamber more often than when uninfected, significantly increasing their mean temperature preference. Parasites maintained continuously at 32 °C decreased to extinction within 3 days, whereas mean parasite abundance increased on hosts incubated at 18 and 24 °C. We show for the first time that gyrodactylid-infected fish have a preference for warmer waters and speculate that sick fish exploit the upper thermal tolerances of their parasites to self medicate

    Characterizing weekly self-reported antihypertensive medication nonadherence across repeated occasions

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    BackgroundLittle is known about weekly variability in medication nonadherence both between and within persons.PurposeTo characterize medication nonadherence across repeated, closely spaced occasions.MethodsThis prospective cohort study comprised four unannounced telephone assessment occasions, each separated by approximately 2 weeks. On each occasion, adult outpatients taking at least a single antihypertensive medication completed a measure of extent of, and reasons for, nonadherence.ResultsTwo hundred and sixty-one participants completed 871 (83%) of 1,044 occasions. Nonadherence was reported on 152 (17.5%) of 871 occasions by 93 (36%) of 261 participants. The most commonly endorsed reasons for nonadherence were forgetting (39.5%), being busy (23.7%), and traveling (19.7%). Among 219 participants completing at least three occasions, 50% of the variability in extent of nonadherence was a result of within-person fluctuations, and 50% was a result of between-person differences.ConclusionInterventions to reduce nonadherence should be informed by variability in the extent of nonadherence and specific reasons for nonadherence

    Sexual Selection and the Evolution of Brain Size in Primates

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    Reproductive competition among males has long been considered a powerful force in the evolution of primates. The evolution of brain size and complexity in the Order Primates has been widely regarded as the hallmark of primate evolutionary history. Despite their importance to our understanding of primate evolution, the relationship between sexual selection and the evolutionary development of brain size is not well studied. The present research examines the evolutionary relationship between brain size and two components of primate sexual selection, sperm competition and male competition for mates. Results indicate that there is not a significant relationship between relative brain size and sperm competition as measured by relative testis size in primates, suggesting sperm competition has not played an important role in the evolution of brain size in the primate order. There is, however, a significant negative evolutionary relationship between relative brain size and the level of male competition for mates. The present study shows that the largest relative brain sizes among primate species are associated with monogamous mating systems, suggesting primate monogamy may require greater social acuity and abilities of deception

    A reference frame for blood volume in children and adolescents

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    BACKGROUND: Our primary purpose was to determine the normal range and variability of blood volume (BV) in healthy children, in order to provide reference values during childhood and adolescence. Our secondary aim was to correlate these vascular volumes to body size parameters and pubertal stages, in order to determine the best normalisation parameter. METHODS: Plasma volume (PV) and red cell volume (RCV) were measured and F-cell ratio was calculated in 77 children with idiopathic nephrotic syndrome in drug-free remission (mean age, 9.8 ± 4.6 y). BV was calculated as the sum of PV and RCV. Due to the dependence of these values on age, size and sex, all data were normalised for body size parameters. RESULTS: BV normalised for lean body mass (LBM) did not differ significantly by sex (p < 0.376) or pubertal stage (p < 0.180), in contrast to normalisation for the other anthropometric parameters. There was no significant difference between reference values for children and adults. CONCLUSION: LBM was the anthropometric index most closely correlated to vascular fluid volumes, independent of age, gender and pubertal stage
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