2,552 research outputs found

    Economic Analysis of Wastewater Reuse in Covenant University

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    Wastewater reuse is a vital technique to supplement existing water resources for both developing and developed nations. However, the economic research into the design and implementation of a wastewater reuse scheme is required in order to determine the feasibility of any wastewater reuse project from an economic stand point. There are numerous benefits of wastewater recycling. However, these benefits are often not evaluated due to several factors. Nevertheless, the valuation of these benefits is required to justify investment decisions. This research uses cost-benefit analysis to evaluate the benefits of implementing a wastewater reuse scheme in a university community. The investment decision is influenced by the result obtained from the cost benefit analysis calculation. The result of the Net Present Value of this research showed that, the University could recoup its initial investments and also realize huge profits implementing a wastewater reuse scheme. Meaning that the research is or would be feasible financially. This research also shows that with the use of constructed wetland, an extensive method of wastewater treatment, the energy costs accrued per year by the University community would be reduced by millions of naira. Furthermore, the environmental and social benefits of the projects were also considered to complete an economic analysis. The results showed that there are significant environmental and social benefits which includes sustainable groundwater withdrawal, the avoidance of land subsidence and corporate social responsibility. Keywords: Wastewater, reuse, Valuation, Expenditur

    Ethylene signalling affects susceptibility of tomatoes to Salmonella

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    Fresh fruits and vegetables are increasingly recognized as important reservoirs of human pathogens, and therefore, significant attention has been directed recently to understanding mechanisms of the interactions between plants and enterics, like Salmonella. A screen of tomato cultivars for their susceptibility to Salmonella revealed significant differences in the ability of this human pathogen to multiply within fruits; expression of the Salmonella genes (cysB, agfB, fadH) involved in the interactions with tomatoes depended on the tomato genotype and maturity stage. Proliferation of Salmonella was strongly reduced in the tomato mutants with defects in ethylene synthesis, perception and signal transduction. While mutation in the ripening-related ethylene receptor Nr resulted only in a modest reduction in Salmonella numbers within tomatoes, strong inhibition of the Salmonella proliferation was observed in rin and nor tomato mutants. RIN and NOR are regulators of ethylene synthesis and ripening. A commercial tomato variety heterozygous for rin was less susceptible to Salmonella under the greenhouse conditions but not when tested in the field over three production seasons

    Differential Energy-Loss Cross Sections for Ionization of Atomic Hydrogen by 25-200-keV Protons

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    Ionization continuum cross sections, differential in energy loss, have been determined from the energy-loss spectra of 25-, 50-, 75-, 145-, and 200-keV protons scattered from atomic hydrogen. The theoretical differential cross sections in the Glauber and Born approximations that are presented show that the theory and the experimental results for 200-keV proton impact agree very well, but below 200 keV there are differences. These differences, which are more pronounced at the lower projectile energies, may be explained in terms of charge transfer to the continuum, which is not treated in our Born and Glauber calculations of direct Coulomb ionization. The total ionization cross sections obtained by integrating the differential cross sections are in reasonable agreement with ionization cross-section measurements that have been obtained from crossed-beam experiments

    A comparison of visual and semiquantitative analysis methods for planar cardiac 123I-MIBG scintigraphy in dementia with Lewy bodies.

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    OBJECTIVES: Cardiac I-MIBG imaging is an established technique for the diagnosis of dementia with Lewy bodies but various analysis methods are reported in the literature. We assessed different methods in the same cohort of patients to inform best practice. PATIENTS AND METHODS: Seventeen patients with dementia with Lewy bodies, 15 with Alzheimer's disease and 16 controls were included. Planar images were acquired 20 min and 4 h after injection. Nine operators produced heart-to-mediastinum ratios (HMRs) using freehand and 6, 7 and 8 cm diameter circular cardiac regions. Interoperator variation was measured using the coefficient of variation. HMR differences between methods were assessed using analysis of variance. Seven raters assessed the images visually. Accuracy was compared using receiver operating characteristic analysis. RESULTS: There were significant differences in HMR between region methods (P=0.006). However, with optimised cut-offs there was no significant difference in accuracy (P=0.2-1.0). The sensitivity was 65-71% and specificity 100% for all HMR methods. Variation was lower with fixed regions than freehand (P<0.001). Visual rating sensitivity and specificity were 65 and 77% on early images and 76 and 71% on delayed images. There was no significant difference in HMR between early and delayed images (P=0.4-0.7) although a greater separation between means was seen on delayed images (0.73 vs. 0.95). CONCLUSION: HMR analysis using a suitable cut-off is more accurate than visual rating. Accuracy is similar for all methods, but freehand regions are more variable and 6 cm circles easiest to place. We recommend calculating HMR using a 6 cm circular cardiac region of interest on delayed images

    Southern pea production

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    The 1<z<5 Infrared Luminosity Function of Type I Quasars

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    We determine the rest-frame 8 micron luminosity function of type I quasars over the redshift range 1<z<5. Our sample consists of 292 24 micron sources brighter than 1 mJy selected from 7.17 square degrees of the Spitzer Space Telescope MIPS survey of the NOAO Deep Wide-Field Survey Bootes field. The AGN and Galaxy Evolution Survey (AGES) has measured redshifts for 270 of the R<21.7 sources and we estimate that the contamination of the remaining 22 sources by stars and galaxies is low. We are able to select quasars missed by ultra-violet excess quasar surveys, including reddened type I quasars and 2.2<z<3.0 quasars with optical colors similar to main sequence stars. We find reddened type I quasars comprise 20% of the type I quasar population. Nonetheless, the shape, normalization, and evolution of the rest-frame 8 micron luminosity function is comparable to that of quasars selected from optical surveys. The 8 micron luminosity function of type I quasars is well approximated by a power-law with index -2.75(+/-0.14). We directly measure the peak of the quasar space density to be at z=2.6(+/-0.3).Comment: Accepted for publication in the ApJ, 19 pages, 12 figure

    Deweyan tools for inquiry and the epistemological context of critical pedagogy

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    This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated

    Early warning signals in psychopathology:what do they tell?

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    BACKGROUND: Despite the increasing understanding of factors that might underlie psychiatric disorders, prospectively detecting shifts from a healthy towards a symptomatic state has remained unattainable. A complex systems perspective on psychopathology implies that such symptom shifts may be foreseen by generic indicators of instability, or early warning signals (EWS). EWS include, for instance, increasing variability, covariance, and autocorrelation in momentary affective states-of which the latter was studied. The present study investigated if EWS predict (i) future worsening of symptoms as well as (ii) the type of symptoms that will develop, meaning that the association between EWS and future symptom shifts would be most pronounced for congruent affective states and psychopathological domains (e.g., feeling down and depression). METHODS: A registered general population cohort of adolescents (mean age 18 years, 36% male) provided ten daily ratings of their affective states for 6 consecutive days. The resulting time series were used to compute EWS in feeling down, listless, anxious, not relaxed, insecure, suspicious, and unwell. At baseline and 1-year follow-up, symptom severity was assessed by the Symptom Checklist-90 (SCL-90). We selected four subsamples of participants who reported an increase in one of the following SCL-90 domains: depression (N = 180), anxiety (N = 192), interpersonal sensitivity (N = 184), or somatic complaints (N = 166). RESULTS: Multilevel models showed that EWS in feeling suspicious anticipated increases in interpersonal sensitivity, as hypothesized. EWS were absent for other domains. While the association between EWS and symptom increases was restricted to the interpersonal sensitivity domain, post hoc analyses showed that symptom severity at baseline was related to heightened autocorrelations in congruent affective states for interpersonal sensitivity, depression, and anxiety. This pattern replicated in a second, independent dataset. CONCLUSIONS: The presence of EWS prior to symptom shifts may depend on the dynamics of the psychopathological domain under consideration: for depression, EWS may manifest only several weeks prior to a shift, while for interpersonal sensitivity, EWS may already occur 1 year in advance. Intensive longitudinal designs where EWS and symptoms are assessed in real-time are required in order to determine at what timescale and for what type of domain EWS are most informative of future psychopathology
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