140 research outputs found

    Differential response to various stimulants in the body and antrum of the canine stomach

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    This study was initiated to evaluate gastric motility with the use of extraluminal force transducers in unanesthetized dogs. The contractile activity of the circular and longitudinal muscle in both antrum and body of the canine stomach was monitored in the interdigestive state and under the influence of food, acetylcholine, and 5-hydroxytryptophane. The latter two chemicals were infused for a 30-min. period. Each of the two muscle layers in antrum and body had a maximum frequency of 5 contractions per minute. This activity was continuous during 30 min. only under the influence of food and 5-hydroxytryptophane. Acetylcholine stimulant effects did not persist beyond the initial 10 min. of infusion. Amplitude of contractions under spontaneous or induced activity varied. The height of these contractions were circular antrum > longitudinal antrum > circular body > longitudinal body. This method of recording muscle contractility is believed to be useful for quantitatively assaying gastric activity without compromise of physiologic environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44365/1/10620_2005_Article_BF02232956.pd

    Superhumps in Cataclysmic Binaries. XXV. q_crit, epsilon(q), and Mass-Radius

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    We report on successes and failures in searching for positive superhumps in cataclysmic variables, and show the superhumping fraction as a function of orbital period. Basically, all short-period systems do, all long-period systems don't, and a 50% success rate is found at P_orb=3.1+-0.2 hr. We can use this to measure the critical mass ratio for the creation of superhumps. With a mass-radius relation appropriate for cataclysmic variables, and an assumed mean white-dwarf mass of 0.75 M_sol, we find a mass ratio q_crit=0.35+-0.02. We also report superhump studies of several stars of independently known mass ratio: OU Virginis, XZ Eridani, UU Aquarii, and KV UMa (= XTE J1118+480). The latter two are of special interest, because they represent the most extreme mass ratios for which accurate superhump measurements have been made. We use these to improve the epsilon(q) calibration, by which we can infer the elusive q from the easy-to-measure epsilon (the fractional period excess of P_superhump over P_orb). This relation allows mass and radius estimates for the secondary star in any CV showing superhumps. The consequent mass-radius law shows an apparent discontinuity in radius near 0.2 M_sol, as predicted by the disrupted magnetic braking model for the 2.1-2.7 hour period gap. This is effectively the "empirical main sequence" for CV secondaries.Comment: PDF, 45 pages, 9 tables, 12 figures; accepted, in press, to appear November 2005, PASP; more info at http://cba.phys.columbia.edu

    WormBase 2016: expanding to enable helminth genomic research

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    WormBase (www.wormbase.org) is a central repository for research data on the biology, genetics and genomics of Caenorhabditis elegans and other nematodes. The project has evolved from its original remit to collect and integrate all data for a single species, and now extends to numerous nematodes, ranging from evolutionary comparators of C. elegans to parasitic species that threaten plant, animal and human health. Research activity using C. elegans as a model system is as vibrant as ever, and we have created new tools for community curation in response to the ever-increasing volume and complexity of data. To better allow users to navigate their way through these data, we have made a number of improvements to our main website, including new tools for browsing genomic features and ontology annotations. Finally, we have developed a new portal for parasitic worm genomes. WormBase ParaSite (parasite.wormbase.org) contains all publicly available nematode and platyhelminth annotated genome sequences, and is designed specifically to support helminth genomic research

    Not interesting enough to be followed by the NSA: An analysis of Dutch privacy attitudes

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    Open curtains and a careless attitude. The Dutch are described as holding an indifferent stance towards privacy in the aftermath of Snowden’s revelations of far-reaching government surveillance. But are Dutch reactions as aloof as often claimed? This study provides an in-depth overview of privacy attitudes in the Dutch debate about the National Security Agency (NSA) leaks, showing a greater variety of sentiments than anticipated. A qualitative frame analysis and a quantitative descriptive analysis resulted in six frames, which convey distinct privacy attitudes. Online and offline as well as professional and non-journalistic content in the debate displays a different distribution of frames. The frames, ranging from an “End justifies the means” attitude to an anxious fear of an “Orwellian dystopia”, are placed in a larger framework as the research demonstrates the connection to existing theories about privacy and surveillance. Dutch discussions about the NSA revelations often display a trade-off narrative balancing safety against privacy, and include (de)legitimisation strategies. These outcomes are in line with previous studies about mediated surveillance debates, which indicates that privacy attitudes transcend national boundaries. However, the inclusion of user-generated content adds an individual dimension to the existing body of research and reveals a personal perspective on surveillance issues

    An 8-gene mRNA expression profile in circulating tumor cells predicts response to aromatase inhibitors in metastatic breast cancer patients

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    Background: Molecular characterization of circulating tumor cells (CTC) is promising for personalized medicine. We aimed to identify a CTC gene expression profile predicting outcome to first-line aromatase inhibitors in metastatic breast cancer (MBC) patients. Methods: CTCs were isolated from 78 MBC patients before treatment start. mRNA expression levels of 96 genes were measured by quantitative reverse transcriptase polymerase chain reaction. After applying predefined exclusion criteria based on lack of sufficient RNA quality and/or quantity, the data from 45 patients were used to construct a gene expression profile to predict poor responding patients, defined as disease progression or death <9 months, by a leave-one-out cross validation. Results: Of the 45 patients, 19 were clinically classified as poor responders. To identify them, the 75 % most variable genes were used to select genes differentially expressed between good and poor responders. An 8-gene CTC predictor was significantly associated with outcome (Hazard Ratio [HR] 4.40, 95 % Confidence Interval [CI]: 2.17-8.92, P < 0.001). This predictor identified poor responding patients with a sensitivity of 63 % and a positive predictive value of 75 %, while good responding patients were correctly predicted in 85 % of the cases. In multivariate Cox regression analysis, including CTC count at baseline, the 8-gene CTC predictor was the only factor independently associated with outcome (HR 4.59 [95 % CI: 2.11-9.56], P < 0.001). This 8-gene signature was not associated with outcome in a group of 71 MBC patients treated with systemic treatments other than AI. Conclusions: An 8-gene CTC predictor was identified which discriminates good and poor outcome to first-line aromatase inhibitors in MBC patients. Although results need to be validated, this study underscores the potential of molecular characterization of CTCs

    Ensembl Genomes 2016: more genomes, more complexity

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    Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species, complementing the resources for vertebrate genomics developed in the context of the Ensembl project (http://www.ensembl.org). Together, the two resources provide a consistent set of programmatic and interactive interfaces to a rich range of data including reference sequence, gene models, transcriptional data, genetic variation and comparative analysis. This paper provides an update to the previous publications about the resource, with a focus on recent developments. These include the development of new analyses and views to represent polyploid genomes (of which bread wheat is the primary exemplar); and the continued up-scaling of the resource, which now includes over 23 000 bacterial genomes, 400 fungal genomes and 100 protist genomes, in addition to 55 genomes from invertebrate metazoa and 39 genomes from plants. This dramatic increase in the number of included genomes is one part of a broader effort to automate the integration of archival data (genome sequence, but also associated RNA sequence data and variant calls) within the context of reference genomes and make it available through the Ensembl user interfaces
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