837 research outputs found

    Use of Fluorescence Microscopy in an Assay of Sperm Density for the Gorgonian Coral, Plexaura kuna

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    The density of sperm in the water column during the broadcast spawning events of marine invertebrates is often undetermined or reported in terms of fertilization potential. The density of sperm during such events can be determined by directly counting numbers of spermatozoa using a modification of the acridine orange direct count (AODC) technique for enumerating bacteria. A number of variables in the handling and processing of samples may bias estimates. Sample collection in glass and rapid fixation and filtration are necessary for reproducible estimates. Once filtered, samples are stable for many months, and counts on filters that were poorly stained in the field can be enhanced by additional staining with 4\u276-diamidino-2-phynlindole (DAPI). The AODC technique was employed to examine the effects of distance from a male colony on density of sperm for the gorgonian coral Plexaura kuna. In situ sperm densities ranged from 0 to 1,000 sperm/ml. Sperm densities in 18 l aquaria containing 20 cm long P. kuna explants reached 100,000 sperm/ml

    Moderate carbohydrate, moderate protein weight loss diet reduces cardiovascular disease risk compared to high carbohydrate, low protein diet in obese adults: A randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>To evaluate the metabolic effects of two weight loss diets differing in macronutrient composition on features of dyslipidemia and post-prandial insulin (INS) response to a meal challenge in overweight/obese individuals.</p> <p>Methods</p> <p>This study was a parallel-arm randomized 4 mo weight loss trial. Adults (n = 50, 47 ± 7 y) matched on BMI (33.6 ± 0.6 kg/m<sup>2</sup>, <it>P </it>= 0.79) consumed energy restricted diets (deficit ~500 kcal/d): PRO (1.6 g.kg<sup>-1</sup>.d<sup>-1 </sup>protein and < 170 g/d carbohydrate) or CHO (0.8 g.kg<sup>-1</sup>.d<sup>-1 </sup>protein and > 220 g/d carbohydrate) for 4 mos. Meal challenges of respective diets were utilized for determination of blood lipids and post-prandial INS and glucose response at the beginning and end of the study.</p> <p>Results</p> <p>There was a trend for PRO to lose more weight (-9.1% vs. -7.3%, <it>P </it>= 0.07) with a significant reduction in percent fat mass compared to CHO (-8.7% vs. -5.7%; <it>P </it>= 0.03). PRO also favored reductions in triacylglycerol (-34% vs. -14%; <it>P </it>< 0.05) and increases in HDL-C (+5% vs. -3%; <it>P </it>= 0.05); however, CHO favored reduction in LDL-C (-7% vs. +2.5%; <it>P </it>< 0.05). INS responses to the meal challenge were improved in PRO compared to CHO (<it>P </it>< 0.05) at both 1 hr (-34.3% vs. -1.0%) and 2 hr (-9.2% vs. +46.2%), an effect that remained significant after controlling for weight or fat loss (both <it>P </it>< 0.05).</p> <p>Conclusion</p> <p>A weight loss diet with moderate carbohydrate, moderate protein results in more favorable changes in body composition, dyslipidemia, and post-prandial INS response compared to a high carbohydrate, low protein diet suggesting an additional benefit beyond weight management to include augmented risk reduction for metabolic disease.</p

    MultiFit: a web server for fitting multiple protein structures into their electron microscopy density map

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    Advances in electron microscopy (EM) allow for structure determination of large biological assemblies at increasingly higher resolutions. A key step in this process is fitting multiple component structures into an EM-derived density map of their assembly. Here, we describe a web server for this task. The server takes as input a set of protein structures in the PDB format and an EM density map in the MRC format. The output is an ensemble of models ranked by their quality of fit to the density map. The models can be viewed online or downloaded from the website. The service is available at; http://salilab.org/multifit/ and http://bioinfo3d.cs.tau.ac.il/

    Motor Learning Guided Treatment for Acquired Apraxia of Speech: Factors That Influence Treatment Outcomes

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    Purpose: The purpose of this study was to examine factors that might influence the treatment effectiveness of motor learning guided (MLG) treatment approach for apraxia of speech (AOS). Specifically, this study examined the effects home practice and the stimuli selection on speech production. Method: This is a case study across two treatment cycles involving a 52 year-old male five months post left CVA (due to a carotid artery dissection). Each treatment cycle used three conditions of practice to investigate the influence of practice frequency on treatment outcomes. The personal relevance of stimuli within and across treatment conditions differed in the treatment cycles to investigate stimuli selection influence on treatment outcomes. Results: Changes in speech motor learning occurred in all conditions of practice only after therapy began. Phrases practiced in therapy and at home met criterion for mastery in fewer sessions than therapy only and untrained phrases. The content of the stimuli did not appear to have a direct influence on speech motor learning. Conclusion: This case study contributes to the growing evidence on the effectiveness of MLG treatment for acquired AOS. Future studies using an experimental design are needed to advance and strengthen the evidence for MLG

    Cosmic Optical Background: the View from Pioneer 10/11

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    We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44 um) and red (~0.64 um) bands. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100 um brightness, while another betrays a constant level in the lowest 100 um brightness region. Presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has the extragalactic origin (i.e., the COB). The derived COB brightness is (1.8 +/- 0.9) x 10^(-9) and (1.2 +/- 0.9) x 10^(-9) erg/s/cm2/sr/A at the blue and red band, respectively, or 7.9 +/- 4.0 and 7.7 +/- 5.8 nW/m2/sr. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions of other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL) - scattered starlight by the interstellar dust. We derive the mean DGL-to-100 um brightness ratios of 2.1 x 10^(-3) and 4.6 x 10^(-3) at the two bands, which are roughly consistent with the previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.Comment: Accepted for publication in the Astrophysical Journal; Typos correcte

    Memberships and CM Diagrams of the Open Cluster NGC 7243

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    The results of astrometric and photometric investigations of the open cluster NGC 7243 are presented. Proper motions of 2165 stars with root-mean-square error of 1.1 mas/yr were obtained by means of PDS scanning of astrometric plates covering the time interval of 97 years. A total of 211 cluster members down to V=15.5 mag have been identified. V and B magnitudes have been determined for 2118 and 2110 stars respectively. Estimations of mass (348Mo < M < 522Mo), age (t=2.5x10^8 yr), distance (r=698 pc) and reddening (E(B-V)=0.24) of the cluster NGC 7243 have been made.Comment: 24 pages, 15 figures. Submitted to Astronomy and Astrophysic

    The 3D Structure of N132D in the LMC: A Late-Stage Young Supernova Remnant

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    We have used the Wide Field Spectrograph (WiFeS) on the 2.3m telescope at Siding Spring Observatory to map the [O III] 5007{\AA} dynamics of the young oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. From the resultant data cube, we have been able to reconstruct the full 3D structure of the system of [O III] filaments. The majority of the ejecta form a ring of ~12pc in diameter inclined at an angle of 25 degrees to the line of sight. We conclude that SNR N132D is approaching the end of the reverse shock phase before entering the fully thermalized Sedov phase of evolution. We speculate that the ring of oxygen-rich material comes from ejecta in the equatorial plane of a bipolar explosion, and that the overall shape of the SNR is strongly influenced by the pre-supernova mass loss from the progenitor star. We find tantalizing evidence of a polar jet associated with a very fast oxygen-rich knot, and clear evidence that the central star has interacted with one or more dense clouds in the surrounding ISM.Comment: Accepted for Publication in Astrophysics & Space Science, 18pp, 8 figure

    XMM-Newton observation of PSR B2224+65 and its jet

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    We have investigated the pulsar PSR B2224+65 and its X-ray jet with XMM-Newton. Apart from the long X-ray jet which is almost perpendicular to the direction of proper motion, a putative extended feature at the pulsar position, which oriented in the opposite direction of the proper motion, is also suggested by this deep X-ray imaging. Non-detection of any coherent X-ray pulsation disfavors the magnetospheric origin of the X-rays observed from the position of PSR B2224+65 and hence suggest that the interpretation of pulsar wind nebula is more viable. We have also probed the origin of PSR B2224+65 and identified a runaway star, which possibly originated from the Cygnus OB9 association, as a candidate for the former binary companion of the neutron star's progenitor.Comment: 24 pages, 8 figures, 3 tables, accepted for publication in Ap

    The Hubble Legacy Archive ACS Grism Data

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    A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 \mum,withadispersionofm, with a dispersion of 40 \ \AA / pixelandaresolutionof and a resolution of \sim 80\ \AAforpointlikesources.TheACSG800Limagesandmatcheddirectimageswerereducedwithanautomaticpipelinethathandlesallstepsfromarchiveretrieval,alignmentandastrometriccalibration,directimagecombination,cataloguegeneration,spectralextractionandcollectionofmetadata.Thelargenumberofextractedspectra(73,581)demandedautomaticmethodsforqualitycontrolandanautomatedclassificationalgorithmwastrainedonthevisualinspectionofseveralthousandspectra.Thefinalsampleofqualitycontrolledspectraincludes47,919datasets(65ofextractedspectra)for for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47,919 datasets (65% of the total number of extracted spectra) for 32,149uniqueobjects,withamedian unique objects, with a median i_{\rm AB}bandmagnitudeof23.7,reaching26.5ABforthefaintestobjects.Eachreleaseddatasetcontainsscienceready1Dand2Dspectra,aswellasmultibandimagecutoutsofcorrespondingsourcesandausefulpreviewpagesummarisingthedirectandslitlessdata,astrometricandphotometricparameters.Inordertocharacterizetheslitlessspectra,emissionlinefluxandequivalentwidthsensitivityoftheACSdatawerecomparedwithpublicgroundbasedspectraintheGOODSSouthfield.Anexamplelistofemissionlinegalaxieswithtwoormoreidentifiedlinesisalsoincluded,coveringtheredshiftrange-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2-4.6$.Comment: Accepted for publication in Astronomy and Astrophysics; 29 pages, 16 Figures, 4 Tables in text and 3Tables in Appendi
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