317 research outputs found
Direct evidence of soft mode behavior near the Burns' temperature in PbMgNbO (PMN) relaxor ferroectric
Inelastic neutron scattering measurements of the relaxor ferroelectric
PbMgNbO (PMN) in the temperature range
490~KT880~K directly observe the soft mode (SM) associated with the
Curie-Weiss behavior of the dielectric constant (T). The results
are treated within the framework of the coupled SM and transverse optic (TO1)
mode and the temperature dependence of the SM frequency at q=0.075 a* is
determined. The parameters of the SM are consistent with the earlier estimates
and the frequency exhibits a minimum near the Burns temperature (
650K)Comment: 6 figure
Sapling size influences shade tolerance ranking among southern boreal tree species
1 Traditional rankings of shade tolerance of trees make little reference to individual size. However, greater respiratory loads with increasing sapling size imply that larger individuals will be less able to tolerate shade than smaller individuals of the same species and that there may be shifts among species in shade tolerance with size. 2 We tested this hypothesis using maximum likelihood estimation to develop individual-tree-based models of the probability of mortality as a function of recent growth rate for seven species: trembling aspen, paper birch, yellow birch, mountain maple, white spruce, balsam fir and eastern white cedar. 3 Shade tolerance of small individuals, as quantified by risk of mortality at low growth, was mostly consistent with traditional shade tolerance rankings such that cedar > balsam fir > white spruce > yellow birch > mountain maple = paper birch > aspen. 4 Differences in growth-dependent mortality were greatest between species in the smallest size classes. With increasing size, a reduced tolerance to shade was observed for all species except trembling aspen and thus species tended to converge in shade tolerance with size. At a given level of radial growth larger trees, apart from aspen, had a higher probability of mortality than smaller trees. 5 Successional processes associated with shade tolerance may thus be most important in the seedling stage and decrease with ontogeny
Organizational and Leadership Implications for Transformational Development
Transformational development is a concept of change that originated in the Christian context but has now become generally used in the work of both secular and faith-based organizations. The growing use of the concept by organizations that are fundamentally different has naturally led to some confusion about what the concept means and what it takes to effectively implement it. In this article, we describe the key features of the concept and how they are important in determining the organizational requirements for its effective implementation. Drawing on a few cases, the paper highlights the centrality of faith in transformational development work
Profaning the sacred in leadership studies: A reading of Murakami's A Wild Sheep Chase
The leadership literature is full of stories of heroic self-sacrifice. Sacrificial leadership behaviour, some scholars conclude, is to be recommended. In this article we follow Keith Grint's conceptualization of leadership as necessarily pertaining to the sacred, but-drawing on Giorgio Agamben's notion of profanation-we highlight the need for organization scholars to profane the sacralizations embedded in leadership thinking. One example of this, which guides us throughout the article, is the novel A Wild Sheep Chase, by the Japanese author Haruki Murakami. By means of a thematic reading of the novel, we discuss how it contributes to profaning particular notions of sacrifice and the sacred in leadership thinking. In the novel, self-sacrifice does not function as a way of establishing a leadership position, but as a way to avoid the dangers associated with leadership, and possibly redeem humans from their current collective urge to become leaders. Inspired by Murakami's fictional example, we call organization scholars to engage in profanation of leadership studies and, in doing so, open new vistas for leadership theory and practice. © The Author(s) 2012
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Community psychiatric nurses and the care co-ordinator role: squeezed to provide ‘limited nursing’.
Background: The Care Programme Approach (CPA) is the key policy underpinning community-focused mental health services but has been unevenly implemented and is associated with increased inpatient bed use. The care co-ordinator role is central to the CPA and is most often held by Community Psychiatric Nurses (CPNs), but there has been little research into how this role is conducted or how it impacts on the work of CPNs and their ability to meet the needs of service users.
Aim: The study aimed to identify and illuminate the factors that either facilitated or constrained the ability of CPNs, in their role as care co-ordinators, to meet service users’ and carers’ needs.
Methods: A multiple case study of seven sectorised community mental health teams was employed over two years using predominantly qualitative methods of participant observation, semi-structured interviews and document review.
Findings: Additional duties and responsibilities specifically associated with the care co-ordinator role and multidisciplinary working, combined with heavy workloads, combined to produce ‘limited nursing’, whereby CPNs are unable to provide evidence-based psychosocial interventions that are recognised to reduce relapse amongst people with severe mental illness.
Conclusions: The role of the CPA care co-ordinator was not designed to support the provision of psychosocial interventions. Consequently, CPNs in the co-ordinator role faced with competing demands are unable to provide the range of structured, evidence-based interventions required. This may partially account for the increased inpatient bed use associated with the CPA
Whole exome sequencing coupled with unbiased functional analysis reveals new Hirschsprung disease genes
Background: Hirschsprung disease (HSCR), which is congenital obstruction of the bowel, results from a failure of enteric nervous system (ENS) progenitors to migrate, proliferate, differentiate, or survive within the distal intestine. Previous studies that have searched for genes underlying HSCR have focused on ENS-related pathways and genes not fitting the current knowledge have thus often been ignored. We identify and validate novel HSCR genes using whole exome sequencing (WES), burden tests, in silico prediction, unbiased in vivo analyses of the mutated genes in zebrafish, and expression analyses in zebrafish, mouse, and human. Results: We performed de novo mutation (DNM) screening on 24 HSCR trios. We identify 28 DNMs in 21 different genes. Eight of the DNMs we identified occur in RET, the main HSCR gene, and the remaining 20 DNMs reside in genes not reported in the ENS. Knockdown of all 12 genes with missense or loss-of-function DNMs showed that the orthologs of four genes (DENND3, NCLN, NUP98, and TBATA) are indispensable for ENS development in zebrafish, and these results were confirmed by CRISPR knockout. These genes are also expressed in human and mouse gut and/or ENS progenitors. Importantly, the encoded proteins are linked to neuronal processes shared by the central nervous system and the ENS. Conclusions: Our data open new fields of investigation into HSCR pathology and provide novel insights into the development of the ENS. Moreover, the study demonstrates that functional analyses of genes carrying DNMs are warranted to delineate the full genetic architecture of rare complex diseases
Clusters of galaxies: setting the stage
Clusters of galaxies are self-gravitating systems of mass ~10^14-10^15 Msun.
They consist of dark matter (~80 %), hot diffuse intracluster plasma (< 20 %)
and a small fraction of stars, dust, and cold gas, mostly locked in galaxies.
In most clusters, scaling relations between their properties testify that the
cluster components are in approximate dynamical equilibrium within the cluster
gravitational potential well. However, spatially inhomogeneous thermal and
non-thermal emission of the intracluster medium (ICM), observed in some
clusters in the X-ray and radio bands, and the kinematic and morphological
segregation of galaxies are a signature of non-gravitational processes, ongoing
cluster merging and interactions. In the current bottom-up scenario for the
formation of cosmic structure, clusters are the most massive nodes of the
filamentary large-scale structure of the cosmic web and form by anisotropic and
episodic accretion of mass. In this model of the universe dominated by cold
dark matter, at the present time most baryons are expected to be in a diffuse
component rather than in stars and galaxies; moreover, ~50 % of this diffuse
component has temperature ~0.01-1 keV and permeates the filamentary
distribution of the dark matter. The temperature of this Warm-Hot Intergalactic
Medium (WHIM) increases with the local density and its search in the outer
regions of clusters and lower density regions has been the quest of much recent
observational effort. Over the last thirty years, an impressive coherent
picture of the formation and evolution of cosmic structures has emerged from
the intense interplay between observations, theory and numerical experiments.
Future efforts will continue to test whether this picture keeps being valid,
needs corrections or suffers dramatic failures in its predictive power.Comment: 20 pages, 8 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 2; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
Notes on the last instar larva and pupa of Hemiargus hanno (Stoll) (Lepidoptera, Lycaenidae, Polyommatinae)
Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV
Peer reviewe
Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV
Peer reviewe
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