2,164 research outputs found

    The effect of turning frequency on in-vessel compost processing and quality

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    Composting can contribute to the zero waste initiative on the University of Arkansas (UA) campus. In-vessel systems like Earth Tubs™ are purported to provide better control of temperature and moisture during the composting process. Turning materials helps facilitate microbial activity and thermophilic composting. The goal of this research was to determine if turning frequency affects processing or final quality of compost made with pre- and post-consumer food waste feedstock and a wood chip bulking agent. Turning frequencies (treatment) of 3 days/week and 7 days/ week were evaluated simultaneously throughout three sequential runs. Temperature, pH, electrical conductivity (EC), and moisture content (MC) were measured weekly during vessel filling. When the vessels reached one-half to two-thirds volumetric capacity, the compost entered a 30- day composting period during which no food waste or wood chips were added to the vessels, but turning continued. Total C, N, C:N ratio, and hot water extractable C (HWEC) and N (HWEN) were also measured at the conclusion of composting. Recommended values for temperature, pH, MC, and total C:N ratio are all possible to reach when composting with Earth Tubs™, but there is little to no effect of 3 days/week versus 7days/week treatment on final quality of compost, and quality is not consistent over time between runs. Further research would need to be done to assess whether Earth Tubs™ are a viable option for large-scale food waste composting at UA, and whether the logistics of having the vessels off-site lend themselves to a sustainable campus-wide composting program

    Judicial Termination of Treaty Water Rights: The Snake River Case

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    This article criticized the Idaho district court\u27s resolution of the Nez Perce Tribe\u27s water rights in the Snake River Basin Adjudication (SRBA). The scope of the tribe\u27s claims were considerable, since they included the right to maintain their fishing practices at the time of their 1855 treaty, The article examined the SRBA decision, the purposes of the 1855 treaty, the nature of the tribe\u27s off-reservation water rights, and the unprincipled termination of those rights by the 1999 SRBA court\u27s decision. The article\u27s call for a correction by the Idaho Supreme Court, which the epilogue to the article noted included a conflict-of-interest on the part of the SRBA court, was later obviated by a settlement between the tribe and the state

    Microdialysis: a method for quantifying in situ nitrogen fluxes in soil microsites

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    Microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has recently been recognized as a candidate for monitoring chemical changes in the rhizosphere. The information it provides about nutrient diffusion may improve nitrogen use efficiency, leading to enhanced management and success of restoration projects. The objective of this study was to determine the efficacy of microdialysis sampling to quantify the relative recoveries (RR%) of nitrate-N and ammonium-N, the two inorganic nitrogen compounds typically found in soil. The effects of microdialysis flow rate, sample medium concentration, and the presence of both analytes in solution on the relative recoveries obtained from dialysate samples were investigated. In comparison to 3.75 and 5.0 ÎźL/min, a flow rate of 2.0 ÎźL/min resulted in an increased relative recovery for both nitrate-N and ammonium-N solutions, at 42.7% and 51.0%, respectively, and was determined to be an optimum rate for subsequent experiments using CMA 20 microdialysis probes. The RR% for both nitrate-N and ammonium-N did not display a statistically significant dependence on the concentration of analyte present in the sample medium. The analytes also did not exhibit interferences, and the presence of both nitrate-N and ammonium-N in the same solution did not influence the RR% of either analyte. The results obtained from this study will assist in validating a novel approach to measuring in situ nitrogen availability in soil with minimal disturbance

    Functional and Biochemical Alterations of the Medial Frontal Cortex in Obsessive-Compulsive Disorder

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    Context: The medial frontal cortex (MFC), including the dorsal anterior cingulate (dAC) and supplementary motor area (SMA), is critical for adaptive and inhibitory control of behaviour. Abnormally high MFC activity has been a consistent finding in functional neuroimaging studies of obsessive-compulsive disorder (OCD). However, the precise regions and the neural alterations associated with this abnormality remain unclear. Objective: To examine the functional and biochemical properties of the MFC in patients with OCD. Design: Cross-sectional design combining volume localized proton magnetic resonance spectroscopy (1H-MRS) and functional MRI (fMRI) with an inhibitory control paradigm (the Multi-Source Interference Task; MSIT) designed to activate the MFC. Setting: Healthy control participants and OCD patients recruited from the general community. Participants: Nineteen OCD patients (10 male, and 9 female) and nineteen age, gender, education and intelligence-matched healthy control participants. Main Outcome Measures: Psychometric measures of symptom severity, MSIT behavioural performance, blood-oxygen-level-dependent (BOLD) activation and 1H-MRS brain metabolite concentrations. Results: MSIT behavioural performance did not differ between OCD patients and control subjects. Reaction-time interference and response errors were correlated with BOLD activation in the dAC region in both groups. Relative to control subjects, OCD patients showed hyper- activation of the SMA during high response-conflict (incongruent > congruent) trials and hyper-activation of the rostral anterior cingulate (rAC) region during low response- conflict (incongruent < congruent) trials. OCD patients also showed reduced levels of neuronal N-acetylaspartate in the dAC region, which was negatively correlated with their BOLD activation of the region. Conclusions: Our findings suggest that hyper-activation of the medial frontal cortex in OCD patients may be a compensatory response to neural pathology in the region. This relationship may partly explain the nature of inhibitory control deficits that are frequently seen in this group and may serve as a focus of future treatment studies

    Has the phasing out of stavudine in accordance with changes in WHO guidelines led to a decrease in single-drug substitutions in first-line antiretroviral therapy for HIV in sub-Saharan Africa?

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    This version is the Accepted Manuscript and is published in final edited form as: AIDS. 2017 January 02; 31(1): 147–157. doi:10.1097/QAD.0000000000001307OBJECTIVE: We assessed the relationship between phasing out stavudine in first-line antiretroviral therapy (ART) in accordance with WHO 2010 policy and single-drug substitutions (SDS) (substituting the nucleoside reverse transcriptase inhibitor in first-line ART) in sub-Saharan Africa. DESIGN: Prospective cohort analysis (International epidemiological Databases to Evaluate AIDS-Multiregional) including ART-naive, HIV-infected patients aged at least 16 years, initiating ART between January 2005 and December 2012. Before April 2010 (July 2007 in Zambia) national guidelines called for patients to initiate stavudine-based or zidovudine-based regimen, whereas thereafter tenofovir or zidovudine replaced stavudine in first-line ART. METHODS: We evaluated the frequency of stavudine use and SDS by calendar year 2004-2014. Competing risk regression was used to assess the association between nucleoside reverse transcriptase inhibitor use and SDS in the first 24 months on ART. RESULTS: In all, 33 441 (8.9%; 95% confience interval 8.7-8.9%) SDS occurred among 377 656 patients in the first 24 months on ART, close to 40% of which were amongst patients on stavudine. The decrease in SDS corresponded with the phasing out of stavudine. Competing risks regression models showed that patients on tenofovir were 20-95% less likely to require a SDS than patients on stavudine, whereas patients on zidovudine had a 75-85% decrease in the hazards of SDS when compared to stavudine. CONCLUSION: The decline in SDS in the first 24 months on treatment appears to be associated with phasing out stavudine for zidovudine or tenofovir in first-line ART in our study. Further efforts to decrease the cost of tenofovir and zidovudine for use in this setting is warranted to substitute all patients still receiving stavudine

    Using framework-based synthesis for conducting reviews of qualitative studies

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    Framework analysis is a technique used for data analysis in primary qualitative research. Recent years have seen its being adapted to conduct syntheses of qualitative studies. Framework-based synthesis shows considerable promise in addressing applied policy questions. An innovation in the approach, known as 'best fit' framework synthesis, has been published in BMC Medical Research Methodology this month. It involves reviewers in choosing a conceptual model likely to be suitable for the question of the review, and using it as the basis of their initial coding framework. This framework is then modified in response to the evidence reported in the studies in the reviews, so that the final product is a revised framework that may include both modified factors and new factors that were not anticipated in the original model. 'Best fit' framework-based synthesis may be especially suitable in addressing urgent policy questions where the need for a more fully developed synthesis is balanced by the need for a quick answer

    Imaging in thick samples, a phased Monte Carlo radiation transfer algorithm

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    This work was supported by the EPSRC (Grant No. EP/K503162/1).Significance : Optical microscopy is characterized by the ability to get high resolution, below 1  μm, high contrast, functional and quantitative images. The use of shaped illumination, such as with lightsheet microscopy, has led to greater three-dimensional isotropic resolution with low phototoxicity. However, in most complex samples and tissues, optical imaging is limited by scattering. Many solutions to this issue have been proposed, from using passive approaches such as Bessel beam illumination to active methods incorporating aberration correction, but making fair comparisons between different approaches has proven to be challenging. Aim : We present a phase-encoded Monte Carlo radiation transfer algorithm (φMC) capable of comparing the merits of different illumination strategies or predicting the performance of an individual approach. Approach : We show that φMC is capable of modeling interference phenomena such as Gaussian or Bessel beams and compare the model with experiment. Results : Using this verified model, we show that, for a sample with homogeneously distributed scatterers, there is no inherent advantage to illuminating a sample with a conical wave (Bessel beam) instead of a spherical wave (Gaussian beam), except for maintaining a greater depth of focus. Conclusion : φMC is adaptable to any illumination geometry, sample property, or beam type (such as fractal or layered scatterer distribution) and as such provides a powerful predictive tool for optical imaging in thick samples.Publisher PDFPeer reviewe

    Midlatitude Oceanic Cloud and Precipitation Properties as Sampled by the ARM Eastern North Atlantic Observatory

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    An edited version of this paper was published by AGU. Copyright 2019 American Geophysical Union.Marine low clouds are critical to the climate system because of their extensive coverage and associated controls on boundary layer dynamics and radiative energy balance. The primary foci for this study are marine low cloud observations over a heavily instrumented site on the Azores archipelago in the Eastern North Atlantic and their associated raindrop size distribution (DSD) properties, relative low cloud contributions to the precipitation, and additional sampling (instrument, environmental) considerations. The contribution from low clouds (e.g., cloud top < 4 km) to the overall precipitation over midlatitude oceans is poorly understood, in part because of the lack of coupled, high‐quality measurements of precipitation and low cloud properties. Cloud regime and precipitation breakdowns performed for a multiyear (2014–2017) record emphasize diurnal precipitation and raindrop size distribution characteristics for both low and deeper clouds, as well as differences between the two disdrometer types used. Results demonstrate that marine low clouds over this Eastern North Atlantic location account for a significant (45%) contribution to the total rainfall and exhibit a diurnal cycle in cloud (thickness, top, and base) and precipitation characteristics similar to satellite records. Additional controls on observed surface rainfall characteristics of low clouds allowed by the extended ground‐based facility data sets are also explored. From those analyses, it is suggested that the synoptic state exerts a significant control on low cloud and surface precipitation properties

    Healthy pregnancies and essential fats: focus group discussions with Zambian women on dietary need and acceptability of a novel RUSF containing fish oil DHA

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    Background: Nut butter-based Ready to Use Supplemental Foods (RUSF) are an effective way to add nutrients and calories to diets of malnourished and food insecure populations. The RUSF formulations have been further modified to add micronutrients including iron and folic acid needed during pregnancy and lactation. Because docosahexaenoic acid (DHA, C22:6 n-3) enhances fetal development and birth outcomes, it has been suggested that perhaps RUSF formulations for pregnancy should also include this Omega 3 fatty acid. The goal of the present study was to gain an understanding of Zambian women’s knowledge of nutritional needs in pregnancy through structured focus group discussions, and to formulate and determine the acceptability of a RUSF with DHA. Methods: Structured focus group sessions were conducted among women attending an antenatal clinic at the University Teaching Hospitals in Lusaka, Zambia. Dietary and nutrition knowledge was surveyed through structured dialogue that was recorded by audio and transcribed verbatim. An RUSF containing 400 mg DHA from fish oil in 50 g RUSF was designed and assessed for fatty acid content and product stability. Participants then sampled the RUSF- DHA, provided feedback on taste, and were surveyed about willingness to consume the novel formula using a standardized hedonic instrument. Results: The participants’ knowledge of foods recommended for use in pregnancy included fruits, vegetables, meat, and fish. Most women reported eating fish at least once per week, although the specific type of fish varied. Most did not have prior knowledge of the importance of consuming fish during pregnancy or that some fish types were more nutritional than others as they included omega 3 fatty acids. The participants were uniformly accepting of the RUSF-DHA for the purpose of enhancing birth and developmental outcomes, but were critical of the aroma in hedonic testing. Conclusions: Women were committed to consuming a healthy diet that would impact the outcome of pregnancy, and were receptive to advice on the importance of consuming foods such as fish as a source of DHA. The RUSF- DHA formulation was acceptable due to the potential benefits for the developing infant, however, the fishy odor may be limiting for long-term daily us
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