2,523 research outputs found

    The Functional and Distributional Ecology of Mycetozoans under Changing Edaphic and Climatic Dynamics

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    Investigations into the distribution and ecosystem functions of fruiting amoebae revealed that local-scale environmental conditions can largely explain broad biogeographical patterns in species assemblage, the way in which amoeboid predators shape bacterial communities and how this top-down influence may affect global biogeochemical processes in a changing climate. The distribution and assemblage of protosteloid amoebae on the islands of New Zealand and Hawaii did not yield any expected patterns of island biogeography, and conformed to other global regions studied. The strongest predictor of species richness in a given region was sampling effort and these species do not appear to have any extant barriers to global dispersal. It is proposed that morphological adaptations such as tiny resilient spores contribute to their ability to disperse widely. In addition, the role of soil amoebae in stimulating the mineralization of soil nutrients was examined using a series of microcosm experiments. It was confirmed that amoeboid predators are causative for large increases in carbon and nitrogen mineralization but that the magnitude of this effect depends on complex interactions between climate and edaphic variables. In particular, land management practices such as no-till agriculture determine the nature of predator responses to climate change with regard to biogeochemical cycling. Subsequently, soil amoebae were shown to have a strong influence on the composition of bacterial communities. This influence was also dependent on climate factors. The predation-induced changes to bacterial taxa was different when incubation temperatures were increased, suggesting that even if protists are considered in models of nutrient dynamics, the parameters describing their influence on decomposer communities will depend on environmental factors. Future work should focus on testing hypotheses concerning the importance of morphology and anthropogenic vectors to amoebal dispersal and on further quantifying the interaction between a changing environment and predator-mediated control of bacterial communities for a wider range of predator taxa

    A Block Minorization--Maximization Algorithm for Heteroscedastic Regression

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    The computation of the maximum likelihood (ML) estimator for heteroscedastic regression models is considered. The traditional Newton algorithms for the problem require matrix multiplications and inversions, which are bottlenecks in modern Big Data contexts. A new Big Data-appropriate minorization--maximization (MM) algorithm is considered for the computation of the ML estimator. The MM algorithm is proved to generate monotonically increasing sequences of likelihood values and to be convergent to a stationary point of the log-likelihood function. A distributed and parallel implementation of the MM algorithm is presented and the MM algorithm is shown to have differing time complexity to the Newton algorithm. Simulation studies demonstrate that the MM algorithm improves upon the computation time of the Newton algorithm in some practical scenarios where the number of observations is large

    La comparación entre la ciencia griega y la china

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    En este trabajo se exploran las diferentes vías por las que la ciencia, la medicina y las matemáticas se desarrollaron en la Grecia y la China antiguas, y se relacionan estas diferencias con los distintos factores ideológicos e institucionales en juego. Se sugieren conexiones, por ejemplo, entre la experiencia política y legal griega, y el interés de los griegos por la evaluación formal de argumentos, incluida la definición y práctica de la demostración axiomático-deductiva estricta. Los chinos se interesaron menos por tales cuestiones secundarias, pero dieron de forma consistente un apoyo institucional mayor a la indagación en áreas tales como la astronomía, que era percibida como importante para el bien del estado

    Every student counts: promoting numeracy and enhancing employability

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    This three-year project investigated factors that influence the development of undergraduates’ numeracy skills, with a view to identifying ways to improve them and thereby enhance student employability. Its aims and objectives were to ascertain: the generic numeracy skills in which employers expect their graduate recruits to be competent and the extent to which employers are using numeracy tests as part of graduate recruitment processes; the numeracy skills developed within a diversity of academic disciplines; the prevalence of factors that influence undergraduates’ development of their numeracy skills; how the development of numeracy skills might be better supported within undergraduate curricula; and the extra-curricular support necessary to enhance undergraduates’ numeracy skills

    Leadership and Diplomacy as Effective Tools for Advancing the Principles of Good Governance and Sustainable Economic Development: A Comparative Examination of Nigeria and Rwanda

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    Objective: This paper aims to analyze the effect of leadership and diplomacy on the good governance and sustainable economic development of Nigeria and Rwanda. The study will focus on the various leadership strategies and capacity-building diplomacy, social welfare diplomacy, and poverty alleviation diplomacy that contribute to good governance and sustainable economic development in these countries. The findings of this research will help to understand the role of leadership and diplomacy in achieving good governance and sustainable economic development in developing countries like Nigeria and Rwanda.   Theoretical Framework: The Transformational Leadership Theory proposed by James MacGregor Burns (1978) and Bernard M. Bass (1985) promotes the adoption of a sustainability mindset, prioritizing sustainability considerations over immediate needs and the Contingency Theory of Leadership by Austrian psychologist Fred E. Fiedler (1960) that focuses on identifying specific environmental variables that can determine the most appropriate leadership strategy for a given situation support this article.   Method: The research strategy employed in this study was a descriptive survey with 114 (57 from Nigeria and 57 from Rwanda) drawn from ministries of Foreign Affairs using a purposeful and simple random selection approach. The sample size was determined using Slovin's method, n= N/ (1 + Ne2) with N=68 and an acceptable margin of error of e=0.05 for each sample group. Questionnaires were used for data collection, and a CVR value of (1), indicating a high level of validity for the instrument, was acquired through the application of Lawshe’s method, while the homogeneity of the instrument was determined by employing the Kudar-Richardson procedure (KR-21) with r-coefficient score of .79, confirmed the dependability of the questionnaire. The data gathered was analyzed using frequency counts, percentages, mean and standard deviation and paired sample t-tests with a significance level set at p < .05 were used for statistical significance.    Findings: The study's findings suggest that the participants from Rwanda had a greater appreciation for the importance of leadership strategies and diplomatic approaches in advancing good governance, sustainable economic development, capacity building, social welfare, and poverty reduction than their Nigerian counterparts. The statistical analysis demonstrated that this disparity was statistically significant at a confidence level of p < .05. Thus, it can be inferred that the effectiveness of leadership and diplomatic approaches depends on the specific country context. Ultimately, these results underscore the critical role of effective leadership and diplomacy in achieving good governance and sustainable economic development.   Conclusion: It is imperative to acknowledge that a substantial portion of the programs encompassing the three dimensions of good governance and sustainable economic development has been duly executed. Nevertheless, it is noteworthy that the sustainability of these programs is often compromised due to several factors such as corruption, insecurity, institutional deterioration, and negative public perception

    Civil Defence (Electricity Undertakings)

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    ERAF: A6 SI 1954.377These regulations, made under section 6 of the Civil Defence Act, 1948, empower the Minister of Fuel and Power to make grants to the British Electricity Authority and Area Electricity Boards towards approved expenses incurred in securing the due functioning of their undertakings in the event of hostile attac
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