Spherical microphone array acoustic rake receivers

Several signal independent acoustic rake receivers are proposed for speech dereverberation using spherical microphone arrays. The proposed rake designs take advantage of multipaths, by separately capturing and combining early reflections with the direct path. We investigate several approaches in combining reflections with the direct path source signal, including the development of beam patterns that point nulls at all preceding reflections. The proposed designs are tested in experimental simulations and their dereverberation performances evaluated using objective measures. For the tested configuration, the proposed designs achieve higher levels of dereverberation compared to conventional signal independent beamforming systems; achieving up to 3.6 dB improvement in the direct-to-reverberant ratio over the plane-wave decomposition beamformer

Reflections on six years in paediatric ART

No Abstrac

Circadian rhythmicity and light sensitivity of the zebrafish brain

Light is important for entraining circadian rhythms, which regulate a wide range of biological processes. Zebrafish have directly light responsive tissues (Whitmore et al 2000) and are thus a useful vertebrate model for circadian rhythmicity and light sensitivity. Recent studies show the pineal regulates locomotor rhythms (Li et al 2012). However, there are many unresolved questions concerning the neurobiological basis of the zebrafish clock, such as whether neuronal pacemakers, which drive rhythms in other tissues, are present throughout the brain. In this study, per3-luc zebrafish confirm that both central and peripheral tissues are directly light sensitive and have endogenous circadian rhythmicity. Chromogenic in situ hybridization reveals localised expression of several core zebrafish clock genes, a rhythmic gene, per3, and two light responsive genes, cry1a and per2. Adult brain nuclei with expression include the suprachiasmatic nucleus, periventricular grey zone of the optic tectum, and granular cells of the rhombencephalon. Pilot experiments using high-resolution spatial recording of per3-luc brain slices show some of these regions can display robust rhythmicity in DD. Some of the cells expressing clock genes are neurons, and therefore neurons were further investigated. C-fos, a marker for neuronal activity in mammalian photoreceptors, is upregulated in at least four different responses to light in zebrafish, in different brain nuclei. This suggests the brain contains several types of photosensitive cells, which respond to different lighting conditions. Zebrafish larvae exhibit developmental changes in spatial circadian gene expression of per3 and light induction of c-fos. Finally, the photopigment group of opsins were investigated for their potential role in light entrainment. Exorh was prominent solely in the pineal. Rgr1 was found in numerous nuclei, many of which had shown expression of cry1a, per2 and per3. Overall, this thesis shows that the zebrafish brain is not uniformly light sensitive. Localised regions in the zebrafish brain with strong rhythmicity and light sensitivity are neuronal pacemaker candidates

Zostera marina (eelgrass) growth and survival along a gradient of nutrients and turbidity in the lower Chesapeake Bay

Survival of transplanted Zostera marina L. (eelgrass), Z. marina growth, and environmental conditions were studied concurrently at a number of sites in a southwestern tributary of the Chesapeake Bay to elucidate the factors limiting macrophyte distribution in this region. Consistent differences in survival of the transplants were observed, with no long-term survival at any of the sites that were formerly vegetated with this species but that currently remain unvegetated. Therefore, the current distribution of Z. marina likely represents the extent of suitable environmental conditions in the region, and the lack of recovery into historically vegetated sites is not solely due to lack of propagules. Poor long-term survival was related to seasonally high levels of water column light attenuation. Fall transplants died by the end of summer following exposure to levels of high spring turbidity (K-d \u3e 3.0) Accumulation of an epiphyte matrix during the late spring (0.36 to 1.14 g g(-1) dry wt) may also have contributed to this stress. Differences in water column nutrient levels among sites during the fall and winter (10 to 15 mu M dissolved inorganic nitrogen and 1 mu M dissolved inorganic phosphates) had no observable effect on epiphyte accumulation or macrophyte growth. Salinity effects were minor and there were no symptoms of disease. Although summertime conditions resulted in depressions in growth, they did not alone limit long-term survival. It is suggested that water quality conditions enhancing adequate seagrass growth during the spring may be key to long-term Z. marina survival and successful recolonization in this region

The Dawn of Open Access to Phylogenetic Data

The scientific enterprise depends critically on the preservation of and open access to published data. This basic tenet applies acutely to phylogenies (estimates of evolutionary relationships among species). Increasingly, phylogenies are estimated from increasingly large, genome-scale datasets using increasingly complex statistical methods that require increasing levels of expertise and computational investment. Moreover, the resulting phylogenetic data provide an explicit historical perspective that critically informs research in a vast and growing number of scientific disciplines. One such use is the study of changes in rates of lineage diversification (speciation - extinction) through time. As part of a meta-analysis in this area, we sought to collect phylogenetic data (comprising nucleotide sequence alignment and tree files) from 217 studies published in 46 journals over a 13-year period. We document our attempts to procure those data (from online archives and by direct request to corresponding authors), and report results of analyses (using Bayesian logistic regression) to assess the impact of various factors on the success of our efforts. Overall, complete phylogenetic data for ~60% of these studies are effectively lost to science. Our study indicates that phylogenetic data are more likely to be deposited in online archives and/or shared upon request when: (1) the publishing journal has a strong data-sharing policy; (2) the publishing journal has a higher impact factor, and; (3) the data are requested from faculty rather than students. Although the situation appears dire, our analyses suggest that it is far from hopeless: recent initiatives by the scientific community -- including policy changes by journals and funding agencies -- are improving the state of affairs

Decreasing intensity of open-ocean convection in the Greenland and Iceland seas

The air–sea transfer of heat and fresh water plays a critical role in the global climate system. This is particularly true for the Greenland and Iceland seas, where these fluxes drive ocean convection that contributes to Denmark Strait overflow water, the densest component of the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). Here we show that the wintertime retreat of sea ice in the region, combined with different rates of warming for the atmosphere and sea surface of the Greenland and Iceland seas, has resulted in statistically significant reductions of approximately 20% in the magnitude of the winter air–sea heat fluxes since 1979. We also show that modes of climate variability other than the North Atlantic Oscillation (NAO) are required to fully characterize the regional air–sea interaction. Mixed-layer model simulations imply that further decreases in atmospheric forcing will exceed a threshold for the Greenland Sea whereby convection will become depth limited, reducing the ventilation of mid-depth waters in the Nordic seas. In the Iceland Sea, further reductions have the potential to decrease the supply of the densest overflow waters to the AMOC

Testing Newtonian Gravity with AAOmega: Mass-to-Light Profiles of Four Globular Clusters

Testing Newtonian gravity in the weak-acceleration regime is vital to our understanding of the nature of the gravitational interaction. It has recently been claimed that the velocity dispersion profiles of several globular clusters flatten out at large radii, reminiscent of galaxy rotation curves, even though globular clusters are thought to contain little or no dark matter. We investigate this claim, using AAOmega observations of four globular clusters, namely M22, M30, M53 and M68. M30, one such cluster that has had this claim made for its velocity dispersion, was included for comparison with previous studies. We find no statistically significant flattening of the velocity dispersion at large radii for any of our target clusters and therefore we infer the observed dynamics do not require that globular clusters are dark matter dominated, or a modification of gravity. Furthermore, by applying a simple dynamical model we determine the radial mass-to-light profiles for each cluster. The isothermal rotations of each cluster are also measured, with M22 exhibiting clear rotation, M68 possible rotation and M30 and M53 lacking any rotation, within the uncertainties.Comment: 7 pages, 4 figures and two tables. Accepted by MNRA

Simvastatin improves the sexual health-related quality of life in men aged 40 years and over with erectile dysfunction : Additional data from the Erectile Dysfunction and Statin trial

© 2014 Trivedi et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Erectile dysfunction is prevalent in men over 40 years, affecting their quality of life and that of their partners. The aims of this study were:a)To evaluate the internal reliability of the male erectile dysfunction specific quality of life (MED-QoL) scale and explore its factor structure.b)To evaluate the effect of simvastatin on subscales of the MED-QoL in men over forty years with erectile dysfunction. Methods: This is a double blind randomised controlled trial of 40 mg simvastatin or placebo given once daily for six months to men over forty years with untreated erectile dysfunction, who were not at high cardiovascular risk and were not on anti-hypertensive or lipid-lowering medication. 173 eligible men were recruited from 10 general practices in East of England. Data were collected at two points over 30 weeks. We report on the factor structure of MED-QoL, the internal reliability of the scale and the derived subscales, and the effect of simvastatin on MED-QoL subscales. Results: An initial analysis of the MED-QoL items suggested that a number of items should be removed (MED-QoL-R). Exploratory factor analysis identified three subscales within the MED-QoL-R which accounted for 96% of the variance, related to feelings of Control, initiating Intimacy, and Emotional response to erectile dysfunction. The alpha value for the revised scale (MED-Qol-R) was >0.95 and exceeded .82 for each subscale. Regression analysis showed that patients in the placebo group experienced a significantly reduced feeling of Control over erectile dysfunction than those in the statin group. Those in the placebo group had significantly lower Emotional response than those in the statin group at the close of trial, but there was no significant treatment effect on Intimacy. Conclusions: Our revised MED-QoL-R identified three subscales. Secondary analysis showed a significant improvement in sexual health related quality of life, specifically in relation to perception of control and emotional health in men with untreated erectile dysfunction given 40 mg simvastatin for six months. Trial registration: Current Controlled Trials ISRCTN66772971.Peer reviewe

Spin-SS generalization of fractional exclusion statistics

We study fractional exclusion statistics for quantum systems with SU(2) symmetry (arbitrary spin $S$), by generalizing the thermodynamic equations with squeezed strings proposed by Ha and Haldane. The bare hole distributions as well as the statistical interaction defined by an infinite-dimensional matrix specify the universality class. It is shown that the system is described by the level-$2S$ WZW model and has a close relationship to non-abelian fractional quantum Hall states. As a low-energy effective theory, the sector of {\it massless} Z$_{2S}$ parafermions is extracted, whose statistical interaction is given by a finite-dimensional matrix.Comment: 11pages, REVTE

Awake Glidescope® intubation in a patient with a huge and fixed supraglottic mass -A case report-

Intubating patients with a huge, fixed supraglottic mass causing an obstruction of the glottis is difficult to most anesthesiologists. We attempted awake fiberoptic orotracheal intubation assisted by Glidescope® Videolaryngoscope (GVL) following topical anesthesia with 4% lidocaine spray and remifentanil infusion. The glottis could not be identified by the GVL view. However, by entering toward the right side of the mass with bronchoscope, the glottis was found. Due to stiffness of the mass, we were unable to further enter the area using the bronchoscope. Alternatively, we attempted to expose the glottis by GVL blade and then successfully intubated the patient by manually pressing the cricoids cartilage. GVL is nonetheless an excellent instrument in airway management compared to fiberoptic bronchoscope for patients with a huge and fixed supraglottic mass