354 research outputs found

    Post-fire Recruitment Failure as a Driver of Forest to Non-forest Ecosystem Shifts in Boreal Regions

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    Climate change and land-use are driving large changes in forest ecosystems around the globe. In the boreal biome it is likely that increases in temperature and the associated lengthening of the growing season will cause the forest to expand into the northern tundra and upwards in elevation, whilst potentially contracting at its southern limits. This increase in temperature is also driving an increase in the frequency and severity of boreal forest fires. A growing number of studies have observed the failure of forest species to re-establish after a standreplacing fire event, which results in the shift to a non-forested ecosystem. In this chapter, this process is referred to as post-fire recruitment failure. We provide multiple lines of evidence for boreal forests, and more specifically for southern Siberia forests, that a possible regional tipping point is unfolding, which could lead to the rapid replacement of large areas of forest ecosystems with low-stature non-forest ecosystems. This change would come with significant consequences for the carbon balance, surface albedo and the resulting altered energy balanc

    Detecting h-index manipulation through self-citation analysis

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    The h-index has received an enormous attention for being an indicator that measures the quality of researchers and organizations. We investigate to what degree authors can inflate their h-index through strategic self-citations with the help of a simulation. We extended Burrell’s publication model with a procedure for placing self-citations, following three different strategies: random self-citation, recent self-citations and h-manipulating self-citations. The results show that authors can considerably inflate their h-index through self-citations. We propose the q-index as an indicator for how strategically an author has placed self-citations, and which serves as a tool to detect possible manipulation of the h-index. The results also show that the best strategy for an high h-index is publishing papers that are highly cited by others. The productivity has also a positive effect on the h-index

    An index to quantify an individual's scientific research output that takes into account the effect of multiple coauthorship

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    I propose the index \hbar ("hbar"), defined as the number of papers of an individual that have citation count larger than or equal to the \hbar of all coauthors of each paper, as a useful index to characterize the scientific output of a researcher that takes into account the effect of multiple coauthorship. The bar is higher for \hbar.Comment: A few minor changes from v1. To be published in Scientometric

    No Plan B: the Achilles heel of high performance sport management

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    Research question: The severity and immediacy of funding cuts to UK National Governing Bodies of Sport (NGBs), driven by the ‘No Compromise’ policy framework for Olympic funding, triggers a cyclical need for turnaround management. Adept strategies during times of considerable challenge is stark, yet literature investigating turnaround management within NGBs remains limited. Consequently, this paper examines two questions: how do NGBs respond to UK Sport funding cuts and how are their responses enabled or restricted by their organisational context? Research methods: A case study methodology was used to develop in-depth insights into how three NGBs responded over a twelve-month period of turnaround management. This was informed by 21 semi-structured interviews with chief executives/presidents, performance managers/head coaches and elite athletes. The actions of the NGBs were analysed through a thematic analysis that made use of Boyne’s (2004) 3 Rs of turnaround strategy. Results and findings: The results highlight that NGBs’ turnaround strategies were constrained by extreme funding dependency and a prohibitive institutional environment that led to states of flux and a focus on short-term operational survival. As a result, the measures taken undermined future success. Implications: An embedded feature of the ‘No Compromise’ framework is severe funding cuts. This should be a significant theme in NGB strategy development. The evidence of this study is that NGBs do not prepare, nor react strategically, when faced with the prospect (or fact of) severe cuts. Consequently, the cases of turnaround management in this study signal the urgent need for further research into the impact of the ‘No Compromise’ framework on the management of NGBs

    Long term productivity and collaboration in information science

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    This is an accepted manuscript of an article published by Springer in Scientometrics on 02/07/2016, available online: https://doi.org/10.1007/s11192-016-2061-8 The accepted version of the publication may differ from the final published version.Funding bodies have tended to encourage collaborative research because it is generally more highly cited than sole author research. But higher mean citation for collaborative articles does not imply collaborative researchers are in general more research productive. This article assesses the extent to which research productivity varies with the number of collaborative partners for long term researchers within three Web of Science subject areas: Information Science & Library Science, Communication and Medical Informatics. When using the whole number counting system, researchers who worked in groups of 2 or 3 were generally the most productive, in terms of producing the most papers and citations. However, when using fractional counting, researchers who worked in groups of 1 or 2 were generally the most productive. The findings need to be interpreted cautiously, however, because authors that produce few academic articles within a field may publish in other fields or leave academia and contribute to society in other ways

    Statistical regularities in the rank-citation profile of scientists

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    Recent science of science research shows that scientific impact measures for journals and individual articles have quantifiable regularities across both time and discipline. However, little is known about the scientific impact distribution at the scale of an individual scientist. We analyze the aggregate production and impact using the rank-citation profile ci(r) of 200 distinguished professors and 100 assistant professors. For the entire range of paper rank r, we fit each ci(r) to a common distribution function. Since two scientists with equivalent Hirsch h-index can have significantly different ci(r) profiles, our results demonstrate the utility of the βi scaling parameter in conjunction with hi for quantifying individual publication impact. We show that the total number of citations Ci tallied from a scientist's Ni papers scales as . Such statistical regularities in the input-output patterns of scientists can be used as benchmarks for theoretical models of career progress

    DOK3 Negatively Regulates LPS Responses and Endotoxin Tolerance

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    Innate immune activation via Toll-like receptors (TLRs), although critical for host defense against infection, must be regulated to prevent sustained cell activation that can lead to cell death. Cells repeatedly stimulated with lipopolysaccharide (LPS) develop endotoxin tolerance making the cells hypo-responsive to additional TLR stimulation. We show here that DOK3 is a negative regulator of TLR signaling by limiting LPS-induced ERK activation and cytokine responses in macrophages. LPS induces ubiquitin-mediated degradation of DOK3 leading to SOS1 degradation and inhibition of ERK activation. DOK3 mice are hypersensitive to sublethal doses of LPS and have altered cytokine responses in vivo. During endotoxin tolerance, DOK3 expression remains stable, and it negatively regulates the expression of SHIP1, IRAK-M, SOCS1, and SOS1. As such, DOK3-deficient macrophages are more sensitive to LPS-induced tolerance becoming tolerant at lower levels of LPS than wild type cells. Taken together, the absence of DOK3 increases LPS signaling, contributing to LPS-induced tolerance. Thus, DOK3 plays a role in TLR signaling during both naïve and endotoxin-induced tolerant conditions

    Prepatterning in the Stem Cell Compartment

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    The mechanism by which an apparently uniform population of cells can generate a heterogeneous population of differentiated derivatives is a fundamental aspect of pluripotent and multipotent stem cell behaviour. One possibility is that the environment and the differentiation cues to which the cells are exposed are not uniform. An alternative, but not mutually exclusive possibility is that the observed heterogeneity arises from the stem cells themselves through the existence of different interconvertible substates that pre-exist before the cells commit to differentiate. We have tested this hypothesis in the case of apparently homogeneous pluripotent human embryonal carcinoma (EC) stem cells, which do not follow a uniform pattern of differentiation when exposed to retinoic acid. Instead, they produce differentiated progeny that include both neuronal and non-neural phenotypes. Our results suggest that pluripotent NTERA2 stem cells oscillate between functionally distinct substates that are primed to select distinct lineages when differentiation is induced
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