141 research outputs found

    The line transect method for estimating densities of large mammals in a tropical deciduous forest: An evaluation of models and field experiments

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    We have evaluated techniques of estimating animal density through direct counts using line transects during 1988-92 in the tropical deciduous forests of Mudumalui Sanctuary in southern India for four species of large herbivorous mammals, namely, chital (Axis axis). sambar (Cervus unicolor). Asian elephant (Elephas maximus) and gaur (Bos gaurus) Density estimates derived from the Fourier Series and the Half-Normal models consistently had the lowest coefficient of variation. These two models also generated similar mean density estimates. For the Fourier Series estimator, appropriate cut-off widths for analyzing line transect data for the four species are suggested. Grouping data into various distance classes did not produce any appreciable differences in estimates of mean density or their variances, although model fit is generally better when data arc placed in fewer groups. The sampling effort needed to achieve a desired precision (coefficient of variation) in the density estimate is derived. A sampling effort of 800 km of transects returned a 10% coefficient of variation on estimate for ehital; for the other species a higher effort was needed to achieve this level of precision. There was no statistically significant relationship between detectability of a group and the size of the group for any species. Density estimates along roads were generally significantly different from those in the interior of the forest, indicating that road-side counts many not be appropriate for most species

    A Bulk-Parallel Priority Queue in External Memory with STXXL

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    We propose the design and an implementation of a bulk-parallel external memory priority queue to take advantage of both shared-memory parallelism and high external memory transfer speeds to parallel disks. To achieve higher performance by decoupling item insertions and extractions, we offer two parallelization interfaces: one using "bulk" sequences, the other by defining "limit" items. In the design, we discuss how to parallelize insertions using multiple heaps, and how to calculate a dynamic prediction sequence to prefetch blocks and apply parallel multiway merge for extraction. Our experimental results show that in the selected benchmarks the priority queue reaches 75% of the full parallel I/O bandwidth of rotational disks and and 65% of SSDs, or the speed of sorting in external memory when bounded by computation.Comment: extended version of SEA'15 conference pape

    Moving Beyond Mimicry: Developing Hybrid Spaces in Indian Business Schools

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    This article analyses the identity work of Indian management educators and scholars as they seek to establish, maintain and revise a sense of self in the context of business school globalization. We show how globalization, combined with the historical legacy of colonialism, renders Indian scholars precarious in their interactions with Western business schools. Based on a qualitative interview study, we explore how Indian business school scholars perform their identities in the context of neo-colonial relations, which are characterised by the dominance of English language and a pressure to conform to research norms set by globally-ranked journals. Drawing on postcolonial theory, our argument focuses on mimicry as a distinctive form of identity work that involves maintaining difference between Western and non-Western identities by 'Othering' Indian scholars, while simultaneously seeking to transform them. We draw attention to ambivalence within participants' accounts, which we suggest arises because the authority of Western scholarship relies on maintaining non-Western scholars in a position of alterity or 'not quite-ness'. We suggest that hybridity offers an opportunity to disrupt and question current practices of business school globalization and facilitate scholarly engagement that reflects more diverse philosophical positions and worldviews

    System differentiation in England: the imposition of supply and demand

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    This chapter describes changing state and sector policy in relation to differentiation and how it has emerged in the English HE context: specifically, the attempts to concentrate the highest qualified applicants and the most prestigious institutions in a 'premium' market segment; the significance of the growing involvement of private providers; and the rise of the ‘student-as-consumer’ and 'value for money' in recent government policy discourse (e.g. the White Papers Students at the Heart of the System (DBIS 2011a) and Success as a Knowledge Economy (DBIS 2016). The chapter situates the development of a market hierarchy (in the form of a vertical differentiation of institutions, Archer 2007) following the demise of the university-polytechnic binary system in 1992 (Further and Higher Education Act, HMSO 1992). This co-existed for several years with the institutional diversity often celebrated by the Higher Education Funding Council for England (e.g. HEFCE 1994; 2000) that can be conceptualised as the horizontal differentiation of valued types of higher education provision and provider (e.g. part-time or vocationally orientated). The introduction of market mechanisms, in various stages beginning with the 2004 Higher Education Act (DfES 2004) and the introduction of variable tuition fees, coincided with the publication of institutional league tables from 2005. Taken together, these have reinforced a hierarchical system in which all institutions and courses are henceforth differentiated only by reference to a set of criteria dominated by the entry requirements demanded, and the amount of research carried out by the institution. Given the implications of the most recent legislation – the Higher Education and Research Act (HMSO 2017) this hierarchy is likely to be matched by one signalled by tuition fee levels, as new cheaper 'challenger' institutions come to the market

    Quantitative proteomics analysis of an ethanol- and a lactate-producing mutant strain of Synechocystis sp. PCC6803

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    BACKGROUND: This study aimed at exploring the molecular physiological consequences of a major redirection of carbon flow in so-called cyanobacterial cell factories: quantitative whole-cell proteomics analyses were carried out on two (14)N-labelled Synechocystis mutant strains, relative to their (15)N-labelled wild-type counterpart. Each mutant strain overproduced one specific commodity product, i.e. ethanol or lactic acid, to such an extent that the majority of the incoming CO2 in the organism was directly converted into the product. RESULTS: In total, 267 proteins have been identified with a significantly up- or down-regulated expression level. In the ethanol-producing mutant, which had the highest relative direct flux of carbon-to-product (>65%), significant up-regulation of several components involved in the initial stages of CO2 fixation for cellular metabolism was detected. Also a general decrease in abundance of the protein synthesizing machinery of the cells and a specific induction of an oxidative stress response were observed in this mutant. In the lactic acid overproducing mutant, that expresses part of the heterologous l-lactate dehydrogenase from a self-replicating plasmid, specific activation of two CRISPR associated proteins, encoded on the endogenous pSYSA plasmid, was observed. RT-qPCR was used to measure, of nine of the genes identified in the proteomics studies, also the adjustment of the corresponding mRNA level. CONCLUSION: The most striking adjustments detected in the proteome of the engineered cells were dependent on the specific product formed, with, e.g. more stress caused by lactic acid- than by ethanol production. Up-regulation of the total capacity for CO2 fixation in the ethanol-producing strain was due to hierarchical- rather than metabolic regulation. Furthermore, plasmid-based expression of heterologous gene(s) may induce genetic instability. For selected, limited, number of genes a striking correlation between the respective mRNA- and the corresponding protein expression level was observed, suggesting that for the expression of these genes regulation takes place primarily at the level of gene transcription
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