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Prophylaxis pharmacotherapy to prevent the onset of post traumatic brain injury depression: a systematic review
YesBackground: Depression is a common psychiatric problem following traumatic brain injury (TBI) with reported prevalence rates of 30-77% in the first year post-TBI. Given the negative influence of post-TBI depression on cognition, interpersonal, social, physical and occupational functioning; early initiation of pharmacotherapy to prevent post-TBI depression has been considered. This systematic review will synthesize the available evidence from published studies on the effectiveness and harms of pharmacotherapy for the secondary prevention of post-TBI depression.
Method: Studies published before November 2017 were reviewed. Six databases were searched, with additional searching of key additional documents. Studies meeting inclusion criteria were evaluated for methodological quality.
Results: Six articles addressing five studies met inclusion criteria. Study designs included three randomised controlled trials (RCT), two retrospective cohorts and one case-control. Prophylactic pharmacotherapy included antidepressants, beta-blockers and statins. In one RCT, the number-needed-to-treat with sertraline to prevent one case of depression post-TBI at 24 weeks was 5.9 (95%CI: 3.1-71.1). Prescribing beta-blockers prior to TBI reduced the depression risk regardless of the specific brain trauma. TBI patients with pre-existing hyperlipidemia not treated with statins had an increased depression risk compared to those without hyperlipidemia.
Conclusion: Early initiation of sertraline prophylaxis in nondepressed TBI patients shows promise to reduce the odds of post-TBI depression developing. However, in the absence of rigorous study of tolerability, existing data are insufficient to recommend sertraline prophylaxis. Optimal timing and treatment duration with identification of patients most likely to benefit from prophylaxis require further consideration. Dedicated prospective studies assessing the effects of beta-blockers and statins on post-TBI depression are required.The Transport Accident Commission (TAC), through the Institute for Safety, Compensation and Recovery Research (ISCRR) at Monash University, provided funding for this review
Phonon-drag effects on thermoelectric power
We carry out a calculation of the phonon-drag contribution to the
thermoelectric power of bulk semiconductors and quantum well structures for the
first time using the balance equation transport theory extended to the weakly
nonuniform systems. Introducing wavevector and phonon-mode dependent relaxation
times due to phonon-phonon interactions, the formula obtained can be used not
only at low temperatures where the phonon mean free path is determined by
boundary scattering, but also at high temperatures. In the linear transport
limit, is equivalent to the result obtained from the Boltzmann equation
with a relaxation time approximation. The theory is applied to experiments and
agreement is found between the theoretical predictions and experimental
results. The role of hot-electron effects in is discussed. The importance
of the contribution of to thermoelectric power in the hot-electron
transport condition is emphasized.Comment: 8 pages, REVTEX 3.0, 7 figures avilable upon reques
Thermoelectric power of nondegenerate Kane semiconductors under the conditions of mutual electron-phonon drag in a high electric field
The thermoelectric power of nondegenerate Kane semiconductors with due regard
for the electron and phonon heating, and their thermal and mutual drags is
investigated. The electron spectrum is taken in the Kane two-band form. It is
shown that the nonparabolicity of electron spectrum significantly influences
the magnitude of the thermoelectric power and leads to a change of its sign and
dependence on the heating electric field. The field dependence of the
thermoelectric power is determined analytically under various drag conditions.Comment: 25 pages, RevTex formatted, 3 table
Pollen signals of ground flora in managed woodlands
This paper explores the vegetation signals contained in the non-arboreal pollen and spore (NAPS) components of pollen assemblages from Tauber traps placed in woodlands subject to rotational cutting (coppicing) in lowland England. Sets of three Tauber traps were placed in compartments of different ages at multiple locations within each woodland for 1 year, and pollen assemblages recorded along with a vegetation survey using a modified pin-frame method in an area of 10 m radius around each trap array. Cluster analysis suggests that, as expected, the ground layer vegetation broadly reflects the different environmental conditions in the three woods, with the main subdivisions within woods apparently driven by changes in ground cover between the early and late stages of the coppice cycle. Non-arboreal pollen and spores (NAPS) assemblages group according to woodland of origin, with subdivisions which relate to pollen abundance but lack a simple relationship with years since cutting. Indices of Association between NAPS records and plant presence in the area around each array were calculated using presence–absence data for multiple distances of vegetation survey. All values tend towards an asymptote, which is interpreted as implying an effective source area for the single taxon presence–absence indicator values of ground flora taxa in coppiced woodlands on the order of a 10 m radius. Only four taxa, Poaceae, Ranunculus acris-type, Cyperaceae, and Scilla-type, have an Index of Association (A) greater than 0.5, implying that the presence of pollen can be interpreted in terms of the local presence of the relevant plant taxon with some confidence. Estimates of Pollen Productivity relative to Poaceae are presented for five taxa: Apiaceae, Asteraceae (Cardueae), Cyperaceae, Mercurialis perennis, and Scilla-type. Years since cutting does affect the ground vegetation and NAPS assemblage trapped in these woods, but that the effect is more clearly seen at an assemblage level in the vegetation than in the pollen assemblages. The interpretative significance of NAPS taxa does not seem to be in providing information about the local conditions around the sampling point, but in reflecting the ground flora of the wider woodland
Approaches to quantitative reconstruction of woody vegetation in managed woodlands from pollen records
There has been increasing interest in developing quantitative methods for reconstructing the dynamics of cultural landscapes over the last 15 years. This paper adds to this literature by using various approaches to reconstruct the vegetation of two woodlands subject to rotational coppicing (the periodic cutting of broadleaved trees and shrubs for wood products). Pollen deposition at ground level was determined at both sites using ‘Tauber’ traps placed near to the centre of 14 compartments of differing age in the coppice rotation. For the main woody taxa, Relative Pollen Productivity (RPP) estimates were derived using linear regression for pollen influx data and Extended R-value analysis for percentage data. The vegetation around three ponds was reconstructed by applying four methods (inverting the two RPP estimate approaches, the modern analogue technique and correction for pollen productivity using the linear regression estimated RPP values) to pollen data obtained from the uppermost sample of sediment from the ponds. To determine whether these methods gave better estimates of the vegetation composition than the original pollen proportions, the results were compared with the surveyed vegetation around each pond using the Bray–Curtis Index. Linear regression of pollen influx produced RPP values which are comparable with previous European studies, whilst for some taxa the Extended R-value analysis produced estimates which are orders of magnitude different both from values derived from the linear regression and previous work. No single approach performed equally well at reconstructing the vegetation around the ponds, and at two of the three locations the uncorrected pollen proportions were most similar to the surveyed vegetation.We conclude that applying quantitative reconstruction methods to individual small sites is, currently, not likely to be useful in complex cultural landscapes. In the context of coppiced woodland, deficiencies in our understanding of pollen taphonomy and the impact of the practice on pollen production first need to be rectified, and we identify strategies to address this situation
Infectious susceptibility and severe deficiency of leukocyte rolling and recruitment in E-selectin and P-selectin double mutant mice
During the initial phase of the inflammatory response, leukocytes marginate and roll along the endothelial surface, a process mediated largely by the selectins and their ligands. Mice with mutations in individual selectins show no spontaneous disease and have mild or negligible deficiencies of inflammatory responses. In contrast, we find that mice with null mutations in both endothelial selectins (P and E) develop a phenotype of leukocyte adhesion deficiency characterized by mucocutaneous infections, plasma cell proliferation, hypergammaglobulinemia, severe deficiencies of leukocyte rolling in cremaster venules with or without addition of TNF-α, and an absence of neutrophil emigration at 4 h in response to intraperitoneal Streptococcus pneumoniae peritonitis. These mice provide strong evidence for the functional importance of selectins in vivo
Computational analysis of transitional airflow through packed columns of spheres using the finite volume technique
Copyright © 2010 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Computers and Chemical Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Computers and Chemical Engineering, Volume 34 Issue 6 (2010), DOI: 10.1016/j.compchemeng.2009.10.013We compare computational simulations of the flow of air through a packed column containing spherical particles with experimental and theoretical results for equivalent beds. The column contained 160 spherical particles at an aspect ratio N=7.14N=7.14, and the experiments and simulations were carried out at particle Reynolds numbers of (RedP=700−5000)(RedP=700−5000). Experimental measurements were taken of the pressure drop across the column and compared with the correlation of Reichelt (1972) using the fitted coefficients of Eisfeld and Schnitzlein (2001). An equivalent computational domain was prepared using Monte Carlo packing, from which computational meshes were generated and analysed in detail. Computational fluid dynamics calculations of the air flow through the simulated bed was then performed using the finite volume technique. Results for pressure drop across the column were found to correlate strongly with the experimental data and the literature correlation. The flow structure through the bed was also analysed in detail
From thermal rectifiers to thermoelectric devices
We discuss thermal rectification and thermoelectric energy conversion from
the perspective of nonequilibrium statistical mechanics and dynamical systems
theory. After preliminary considerations on the dynamical foundations of the
phenomenological Fourier law in classical and quantum mechanics, we illustrate
ways to control the phononic heat flow and design thermal diodes. Finally, we
consider the coupled transport of heat and charge and discuss several general
mechanisms for optimizing the figure of merit of thermoelectric efficiency.Comment: 42 pages, 22 figures, review paper, to appear in the Springer Lecture
Notes in Physics volume "Thermal transport in low dimensions: from
statistical physics to nanoscale heat transfer" (S. Lepri ed.
Demonstration of a novel technique to measure two-photon exchange effects in elastic scattering
The discrepancy between proton electromagnetic form factors extracted using
unpolarized and polarized scattering data is believed to be a consequence of
two-photon exchange (TPE) effects. However, the calculations of TPE corrections
have significant model dependence, and there is limited direct experimental
evidence for such corrections. We present the results of a new experimental
technique for making direct comparisons, which has the potential to
make precise measurements over a broad range in and scattering angles. We
use the Jefferson Lab electron beam and the Hall B photon tagger to generate a
clean but untagged photon beam. The photon beam impinges on a converter foil to
generate a mixed beam of electrons, positrons, and photons. A chicane is used
to separate and recombine the electron and positron beams while the photon beam
is stopped by a photon blocker. This provides a combined electron and positron
beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen
target. The large acceptance CLAS detector is used to identify and reconstruct
elastic scattering events, determining both the initial lepton energy and the
sign of the scattered lepton. The data were collected in two days with a
primary electron beam energy of only 3.3 GeV, limiting the data from this run
to smaller values of and scattering angle. Nonetheless, this measurement
yields a data sample for with statistics comparable to those of the
best previous measurements. We have shown that we can cleanly identify elastic
scattering events and correct for the difference in acceptance for electron and
positron scattering. The final ratio of positron to electron scattering:
for GeV and
Measurement of the Nucleon Structure Function F2 in the Nuclear Medium and Evaluation of its Moments
We report on the measurement of inclusive electron scattering off a carbon
target performed with CLAS at Jefferson Laboratory. A combination of three
different beam energies 1.161, 2.261 and 4.461 GeV allowed us to reach an
invariant mass of the final-state hadronic system W~2.4 GeV with four-momentum
transfers Q2 ranging from 0.2 to 5 GeV2. These data, together with previous
measurements of the inclusive electron scattering off proton and deuteron,
which cover a similar continuous two-dimensional region of Q2 and Bjorken
variable x, permit the study of nuclear modifications of the nucleon structure.
By using these, as well as other world data, we evaluated the F2 structure
function and its moments. Using an OPE-based twist expansion, we studied the
Q2-evolution of the moments, obtaining a separation of the leading-twist and
the total higher-twist terms. The carbon-to-deuteron ratio of the leading-twist
contributions to the F2 moments exhibits the well known EMC effect, compatible
with that discovered previously in x-space. The total higher-twist term in the
carbon nucleus appears, although with large systematic uncertainites, to be
smaller with respect to the deuteron case for n<7, suggesting partial parton
deconfinement in nuclear matter. We speculate that the spatial extension of the
nucleon is changed when it is immersed in the nuclear medium.Comment: 37 pages, 15 figure
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