5,032 research outputs found

    On the Measurement of Roller Skew of Tapered Roller Bearings

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    Roller skew in roller bearings can cause heat generation and reduce bearing life. Therefore, design to minimise its occurrence is essential in bearing development. This study investigated the roller skew of a double row tapered roller bearing under various running conditions. A new system of measurement using two differential variable reluctance transducers (DVRT) was developed. It is evident that the roller skew of the double row tapered roller bearing can be measured. The shaft rotational speed has a significant effect on roller skew but the radial load has little effect.Peer reviewedFinal Accepted Versio

    A survey of University of Richmond Evening School students : their motives, progress after study and the extent of assistance by employers in educational programs

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    The aim of this thesis is to suvey a representative group of Evening School students and business firms to gather qualitative data concerning the Evening School and present these data in a quantitative manner. Research was conducted by questionnaire in order to collect original source data. Replies to questionnaires have been analyzed. Tabulations of data are included throughout the text. A summary follows analyses of replies

    Application of Near-Infrared Reflectance Spectroscopy to Estimate Post Mortem Interval

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    Estimating the post mortem interval of human remains is extremely important in death scene investigations. Currently, the rate of decomposition is gaged by a number of techniques, such as insect development, a function in part of environmental and weather conclusions. However, there are limitations with the process that prevent more accurate assessments. Near-infrared reflectance spectroscopy may provide complimentary and supportive estimates of the post mortem interval. The goal of this research was to determine if near-infrared reflectance spectroscopy (NIRS) could detect changes in decomposing skin of feral swine as a model system. NIRS spectra were obtained from swine skin samples exposed to natural elements (daily temperature, precipitation, humidity and solar radiation) on the campus of Texas A&M University during warm (July) and cool (February) seasons. Linear regression analysis of spectral data by sample age and state of decomposition were found to be highly correlated (R2=0.8749) during the warm period exposure. The same regression analysis of spectral data taken during the cool exposure months produced an R2 of 0.812

    Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans

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    With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection

    Slips of the Tongue: The Facts and a Stratificational Model

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    Paper by Gary S. Dell and Peter A. Reic

    A structural approach to kernels for ILPs: Treewidth and Total Unimodularity

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    Kernelization is a theoretical formalization of efficient preprocessing for NP-hard problems. Empirically, preprocessing is highly successful in practice, for example in state-of-the-art ILP-solvers like CPLEX. Motivated by this, previous work studied the existence of kernelizations for ILP related problems, e.g., for testing feasibility of Ax <= b. In contrast to the observed success of CPLEX, however, the results were largely negative. Intuitively, practical instances have far more useful structure than the worst-case instances used to prove these lower bounds. In the present paper, we study the effect that subsystems with (Gaifman graph of) bounded treewidth or totally unimodularity have on the kernelizability of the ILP feasibility problem. We show that, on the positive side, if these subsystems have a small number of variables on which they interact with the remaining instance, then we can efficiently replace them by smaller subsystems of size polynomial in the domain without changing feasibility. Thus, if large parts of an instance consist of such subsystems, then this yields a substantial size reduction. We complement this by proving that relaxations to the considered structures, e.g., larger boundaries of the subsystems, allow worst-case lower bounds against kernelization. Thus, these relaxed structures can be used to build instance families that cannot be efficiently reduced, by any approach.Comment: Extended abstract in the Proceedings of the 23rd European Symposium on Algorithms (ESA 2015

    Cellular O-Glycome Reporter/Amplification to explore O-glycans of living cells

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    Protein O-glycosylation has key roles in many biological processes, but the repertoire of O-glycans synthesized by cells is difficult to determine. Here we describe an approach termed Cellular O-Glycome Reporter/Amplification (CORA), a sensitive method used to amplify and profile mucin-type O-glycans synthesized by living cells. Cells convert added peracetylated benzyl-α-N-acetylgalactosamine to a large variety of modified O-glycan derivatives that are secreted from cells, allowing for easy purification for analysis by HPLC and mass spectrometry (MS). Relative to conventional O-glycan analyses, CORA resulted in an ∼100-1,000-fold increase in sensitivity and identified a more complex repertoire of O-glycans in more than a dozen cell types from Homo sapiens and Mus musculus. Furthermore, when coupled with computational modeling, CORA can be used for predictions about the diversity of the human O-glycome and offers new opportunities to identify novel glycan biomarkers for human diseases
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