192 research outputs found

    Crop Nitrogen and Phosphorus Utilization following Application of Slurry from Swine Fed Traditional or Low Phytate Corn Diets

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    Field application of swine (Sus scrofa) slurry provides essential nutrients for crop production. The N to P ratio for slurry is lower than needed by most crops resulting in P accumulation when applied at N rates required for crop growth. Low phytate corn (Zea mays L.) (LPC) contains similar amounts of total P but less phytate P than traditional corn (TC) resulting in improved P bioavailability and reduced P excretion by monogastric animals. While manure from swine-fed LPC diets has a higher N to P ratio than that from TC diets, field studies comparing crop utilization of nutrients from LPC manure have not been conducted. A field study was conducted to compare N and P utilization by no-tillage rainfed sorghum [Sorghum bicolor (L.) Moench.] receiving three annual surface applications of nutrients (inorganic fertilizer, LPC slurry, and TC slurry) and by irrigated corn receiving one incorporated application of nutrients. Sorghum grain and total dry matter N utilization exhibited a year by treatment interaction but total dry matter N utilization was similar for both manure types in all years (61.2 ± 2.6% for TC and 53.8 ± 2.6% for LPC). Grain P utilization was similar for inorganic fertilizer and manure but differed among years (44.4 ± 7.0% in 1999, 25.1 ± 1.4% in 2000, and 57.0 ± 2.2% in 2001). Corn grain N and P utilization did not diff er among nutrient sources in the year of application (50.7 ± 2.4% for N and 40.4 ± 3.0 for P) and increased little in the year following application (62.2 ± 3.0% for N and 50.2 ± 4.5% for P). Crop N and P utilization from LPC manure and TC manure was similar and nutrient guidelines developed for TC swine slurry should also apply for LPC slurry

    Bacterial assemblages of the eastern Atlantic Ocean reveal both vertical and latitudinal biogeographic signatures

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    Microbial communities are recognized as major drivers of the biogeochemical processes in the oceans. However, the genetic diversity and composition of those communities is poorly understood. The aim of this study is to investigate the composition of bacterial assemblages in three different water layer habitats: surface (2–20 m), deep chlorophyll maximum (DCM; 28–90 m), and deep (100–4600 m) at nine stations along the eastern Atlantic Ocean from 42.8° N to 23.7° S. The sampling of three discrete, predefined habitat types from different depths, Longhurstian provinces, and geographical locations allowed us to investigate whether marine bacterial assemblages show spatial variation and to determine if the observed spatial variation is influenced by current environmental conditions, historical/geographical contingencies, or both. The PCR amplicons of the V6 region of the 16S rRNA from 16 microbial assemblages were pyrosequenced, generating a total of 352 029 sequences; after quality filtering and processing, 257 260 sequences were clustered into 2871 normalized operational taxonomic units (OTU) using a definition of 97% sequence identity. Community ecology statistical analyses demonstrate that the eastern Atlantic Ocean bacterial assemblages are vertically stratified and associated with water layers characterized by unique environmental signals (e.g., temperature, salinity, and nutrients). Genetic compositions of bacterial assemblages from the same water layer are more similar to each other than to assemblages from different water layers. The observed clustering of samples by water layer allows us to conclude that contemporary environments are influencing the observed biogeographic patterns. Moreover, the implementation of a novel Bayesian inference approach that allows a more efficient and explicit use of all the OTU abundance data shows a distance effect suggesting the influence of historical contingencies on the composition of bacterial assemblages. Surface bacterial communities displayed a general congruency with the ecological provinces as defined by Longhurst with modest exceptions usually associated with unique hydrographic and biogeochemical features. Collectively, our findings suggest that vertical (habitat) and latitudinal (distance) biogeographic signatures are present and that both environmental parameters and ecological provinces drive the composition of bacterial assemblages in the eastern Atlantic Ocean

    The future of social is personal: the potential of the personal data store

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    This chapter argues that technical architectures that facilitate the longitudinal, decentralised and individual-centric personal collection and curation of data will be an important, but partial, response to the pressing problem of the autonomy of the data subject, and the asymmetry of power between the subject and large scale service providers/data consumers. Towards framing the scope and role of such Personal Data Stores (PDSes), the legalistic notion of personal data is examined, and it is argued that a more inclusive, intuitive notion expresses more accurately what individuals require in order to preserve their autonomy in a data-driven world of large aggregators. Six challenges towards realising the PDS vision are set out: the requirement to store data for long periods; the difficulties of managing data for individuals; the need to reconsider the regulatory basis for third-party access to data; the need to comply with international data handling standards; the need to integrate privacy-enhancing technologies; and the need to future-proof data gathering against the evolution of social norms. The open experimental PDS platform INDX is introduced and described, as a means of beginning to address at least some of these six challenges

    Accurate MR thermometry by hyperpolarized 129Xe

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    Purpose: To investigate the temperature dependence of the resonance frequency of lipid-dissolved xenon (LDX) and to assess the accuracy of LDX-based MR thermometry. Methods: The chemical shift temperature dependence of water protons, methylene protons, and LDX was measured from samples containing tissues with varying fat contents using a high-resolution NMR spectrometer. LDX results were then used to acquire relative and absolute temperature maps in vivo and the results were compared with PRF-based MR thermometry. Results: The temperature dependence of proton resonance frequency (PRF) is strongly affected by the specific distribution of water and fat. A redistribution of water and fat compartments can reduce the apparent temperature dependence of the water chemical shift from −0.01 ppm/°C to −0.006 ppm, whereas the LDX chemical shift shows a consistent temperature dependence of −0.21 ppm/°C. The use of the methylene protons resonance frequency as internal reference improves the accuracy of LDX-based MR thermometry, but degrades that of PRF-based MR thermometry, as microscopic susceptibility gradients affected lipid and water spins differently. Conclusion: The LDX resonance frequency, with its higher temperature dependence, provides more accurate and precise temperature measurements, both in vitro and in vivo. More importantly, the resonance frequency of nearby methylene protons can be used to extract absolute temperature information

    MSH3 polymorphisms and protein levels affect CAG repeat instability in huntington's disease mice

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    Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)~100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of DNA repair genes may have prognostic implications for various repeat-associated diseases

    St. Louis Area Earthquake Hazards Mapping Project: Seismic and Liquefaction Hazard Maps

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    We present probabilistic and deterministic seismic and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near-surface shear-wave velocity model in a 1D equivalent- linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National Seismic Hazard Model, which uses a uniform firm-rock-site condition, the new probabilistic seismic-hazard estimates document much more variability. Hazard levels for upland sites (consisting of bedrock and weathered bedrock overlain by loess-covered till and drift deposits), show up to twice the ground-motion values for peak ground acceleration (PGA), and similar ground-motion values for 1.0 s spectral acceleration (SA). Probabilistic ground-motion levels for lowland alluvial floodplain sites (generally the 20-40-m-thick modern Mississippi and Missouri River floodplain deposits overlying bedrock) exhibit up to twice the ground-motion levels for PGA, and up to three times the ground-motion levels for 1.0 s SA. Liquefaction probability curves were developed from available standard penetration test data assuming typical lowland and upland water table levels. A simplified liquefaction hazard map was created from the 5%-in-50-year probabilistic ground-shaking model. The liquefaction hazard ranges from low (\u3c40% of area expected to liquefy) in the uplands to severe (\u3e60% of area expected to liquefy) in the lowlands. Because many transportation routes, power and gas transmission lines, and population centers exist in or on the highly susceptible lowland alluvium, these areas in the St. Louis region are at significant potential risk from seismically induced liquefaction and associated ground deformation

    Driven to excess? Linking calling, character and the (mis)behaviour of marketers

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    We are presently at a point of unique circumstantial convergence where recession, an increased emphasis on business ethics, and marketer’s reluctance to accept shifting social agendas have combined to identify the need for a new approach to marketing. Using concepts from the human resources, marketing and psychology literatures, and especially Erich Fromm’s ideas concerning economic character, this paper posits that marketers – as a professional community – are driven to promote consumerist outcomes; victims of an automaton amalgam of calling and character. The analysis suggests the vulnerability of both marketer and consumer are mutually reinforcing and that we need, somehow, to break this damaging cycle of dependence. We know little, however, about how marketers think and feel about their discipline, so this paper also promotes an agenda for marketer behaviour research, as a countervailing balance to a currently disproportionate focus on the consumer

    Predicting Bevirimat resistance of HIV-1 from genotype

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    <p>Abstract</p> <p>Background</p> <p>Maturation inhibitors are a new class of antiretroviral drugs. Bevirimat (BVM) was the first substance in this class of inhibitors entering clinical trials. While the inhibitory function of BVM is well established, the molecular mechanisms of action and resistance are not well understood. It is known that mutations in the regions CS p24/p2 and p2 can cause phenotypic resistance to BVM. We have investigated a set of p24/p2 sequences of HIV-1 of known phenotypic resistance to BVM to test whether BVM resistance can be predicted from sequence, and to identify possible molecular mechanisms of BVM resistance in HIV-1.</p> <p>Results</p> <p>We used artificial neural networks and random forests with different descriptors for the prediction of BVM resistance. Random forests with hydrophobicity as descriptor performed best and classified the sequences with an area under the Receiver Operating Characteristics (ROC) curve of 0.93 ± 0.001. For the collected data we find that p2 sequence positions 369 to 376 have the highest impact on resistance, with positions 370 and 372 being particularly important. These findings are in partial agreement with other recent studies. Apart from the complex machine learning models we derived a number of simple rules that predict BVM resistance from sequence with surprising accuracy. According to computational predictions based on the data set used, cleavage sites are usually not shifted by resistance mutations. However, we found that resistance mutations could shorten and weaken the <it>α</it>-helix in p2, which hints at a possible resistance mechanism.</p> <p>Conclusions</p> <p>We found that BVM resistance of HIV-1 can be predicted well from the sequence of the p2 peptide, which may prove useful for personalized therapy if maturation inhibitors reach clinical practice. Results of secondary structure analysis are compatible with a possible route to BVM resistance in which mutations weaken a six-helix bundle discovered in recent experiments, and thus ease Gag cleavage by the retroviral protease.</p
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