3,929 research outputs found
Quantification of mesoscale variability and geometrical reconstruction of a textile
Automated image analysis of textile surfaces allowed determination and quantification of intrinsic yarn path variabilities in a 2/2 twill weave during the lay-up process. The yarn paths were described in terms of waves and it was found that the frequencies are similar in warp and weft directions and hardly affected by introduced yarn path deformations. The most significant source of fabric variability was introduced during handling before cutting. These resulting systematic deformations will need to be considered when designing or analysing a composite component. An automated method for three dimensional reconstruction of the analysed lay-up was implemented in TexGen which will allow virtual testing of components in the future
Experiencing gender in UK political science:The results of a practitioner survey
Does gender matter in the way in which we ‘perform’ academia? Drawing on the results of a practitioner survey, we argue that gender does matter, culturally and structurally, and can be institutionalised so that women are disadvantaged. This is not to deny women’s agency or the advances that they have made. Rather, we highlight the inequality of the playing field in which the academic endeavour is conducted. Uniquely, we ask UK political scientists about their perceptions of the impact of gender in their working lives and explore their views on recommendations for change
Awareness and willingness to use HIV pre-exposure prophylaxis amongst gay and bisexual men in Scotland: implications for biomedical HIV prevention
Objectives:<p></p>
To investigate the awareness of, and willingness to use, HIV Pre-Exposure Prophylaxis (PrEP), and willingness to take part in a PrEP study among gay and bisexual men in Scotland.<p></p>
Methods:<p></p>
Cross-sectional survey of 17 gay commercial venues in Glasgow and Edinburgh in May 2011 (N = 1515, 65.2% response rate); 1393 are included in the analyses.<p></p>
Results:<p></p>
Just under one-third of participants had heard of PrEP (n = 434; 31.2%), with awareness associated with being aged older than 35 years, talking to UAI partners about HIV, and with having had an HIV or STI test in the previous 12 months. Around half were willing to take part in a PrEP study (n = 695; 49.9%) or to take PrEP on a daily basis (n = 756; 54.3%). In multivariate analysis, willingness to take PrEP was associated with lower levels of education, regular gay scene attendance, ‘high-risk’ unprotected anal intercourse (UAI) and testing for HIV or STI in the previous 12 months. Reasons for not wanting to participate in a PrEP study or take PrEP included perceptions of low personal risk of HIV and concerns with using medication as an HIV prevention method.<p></p>
Conclusions:<p></p>
There is a willingness to engage in new forms of HIV prevention and research amongst a significant number of gay and bisexual men in Scotland. Future biomedical HIV interventions need to consider the links between sexual risk behaviour, testing, and potential PrEP use
A Microsoft-Excel-based tool for running and critically appraising network meta-analyses--an overview and application of NetMetaXL.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.BACKGROUND: The use of network meta-analysis has increased dramatically in recent years. WinBUGS, a freely available Bayesian software package, has been the most widely used software package to conduct network meta-analyses. However, the learning curve for WinBUGS can be daunting, especially for new users. Furthermore, critical appraisal of network meta-analyses conducted in WinBUGS can be challenging given its limited data manipulation capabilities and the fact that generation of graphical output from network meta-analyses often relies on different software packages than the analyses themselves. METHODS: We developed a freely available Microsoft-Excel-based tool called NetMetaXL, programmed in Visual Basic for Applications, which provides an interface for conducting a Bayesian network meta-analysis using WinBUGS from within Microsoft Excel. . This tool allows the user to easily prepare and enter data, set model assumptions, and run the network meta-analysis, with results being automatically displayed in an Excel spreadsheet. It also contains macros that use NetMetaXL's interface to generate evidence network diagrams, forest plots, league tables of pairwise comparisons, probability plots (rankograms), and inconsistency plots within Microsoft Excel. All figures generated are publication quality, thereby increasing the efficiency of knowledge transfer and manuscript preparation. RESULTS: We demonstrate the application of NetMetaXL using data from a network meta-analysis published previously which compares combined resynchronization and implantable defibrillator therapy in left ventricular dysfunction. We replicate results from the previous publication while demonstrating result summaries generated by the software. CONCLUSIONS: Use of the freely available NetMetaXL successfully demonstrated its ability to make running network meta-analyses more accessible to novice WinBUGS users by allowing analyses to be conducted entirely within Microsoft Excel. NetMetaXL also allows for more efficient and transparent critical appraisal of network meta-analyses, enhanced standardization of reporting, and integration with health economic evaluations which are frequently Excel-based.CC is a recipient of a Vanier Canada Graduate Scholarship from the Canadian Institutes of Health Research (funding reference number—CGV 121171) and is a trainee on the Canadian Institutes of Health Research Drug Safety and Effectiveness Network team grant (funding reference number—116573). BH is funded by a New Investigator award from the Canadian Institutes of Health Research and the Drug Safety and Effectiveness Network. This research was partly supported by funding from CADTH as part of a project to develop Excel-based tools to support the conduct of health technology assessments. This research was also supported by Cornerstone Research Group
Black Hole Hair Removal: Non-linear Analysis
BMPV black holes in flat transverse space and in Taub-NUT space have
identical near horizon geometries but different microscopic degeneracies. It
has been proposed that this difference can be accounted for by different
contribution to the degeneracies of these black holes from hair modes, --
degrees of freedom living outside the horizon. In this paper we explicitly
construct the hair modes of these two black holes as finite bosonic and
fermionic deformations of the black hole solution satisfying the full
non-linear equations of motion of supergravity and preserving the supersymmetry
of the original solutions. Special care is taken to ensure that these solutions
do not have any curvature singularity at the future horizon when viewed as the
full ten dimensional geometry. We show that after removing the contribution due
to the hair degrees of freedom from the microscopic partition function, the
partition functions of the two black holes agree.Comment: 40 pages, LaTe
Changes in intracellular ion activities induced by adrenaline in human and rat skeletal muscle
To study the stimulating effect of adrenaline (ADR) on active Na+/K+ transport we used double-barrelled ion-sensitive micro-electrodes to measure the activities of extracellular K+ (aKe) and intracellular Na+ (aNai) in isolated preparations of rat soleus muscle, normal human intercostal muscle and one case of hyperkalemic periodic paralysis (h.p.p.). In these preparations bath-application of ADR (10−6 M) resulted in a membrane hyperpolarization and transient decreasesaKe andaNai which could be blocked by ouabain (3×10−4 M). In the h.p.p. muslce a continuous rise ofaNai induced by elevation ofaKe to 5.2 mM could be stopped by ADR. In addition, the intracellular K+ activity (aKi), the free intracellular Ca2+ concentration (pCai) and intracellular pH (pHi) were monitored in rat soleus muscle. During ADRaKi increased, pHi remained constant and intracellular Ca2+ apparently decreased. In conclusion, our data show that ADR primarily stimulates the Na+/K+ pump in mammalian skeletal muscle. This stimulating action is not impaired in the h.p.p. muscle
Isothermal Crystallization Kinetics of Sodium Dodecyl Sulfate–Water Micellar Solutions
The
crystallization mechanisms and kinetics of micellar sodium
dodecyl sulfate (SDS) solutions in water, under isothermal conditions,
were investigated experimentally by a combination of reflection optical
microscopy (OM), differential scanning calorimetry (DSC), and attenuated
total reflection Fourier transform infrared spectroscopy (ATR-FTIR).
The rates of nucleation and growth were estimated from OM and DSC
across temperatures ranging from 20 to −6 °C for 20% SDS-H<sub>2</sub>O, as well as for 10 and 30% SDS-H<sub>2</sub>O at representative
temperatures of 6, 2, and −2 °C. A decrease in temperature
increased both nucleation and growth rates, and the combined effect
of the two processes on the morphology was quantified via both OM
and ATR-FTIR. Needles, corresponding to the hemihydrate polymorph,
become the dominant crystal form at ≤ −2 °C, while
platelets, the monohydrate, predominate at higher temperatures. Above
8 °C, crystallization was only observed if seeded from crystals
generated at lower temperatures. Our results provide quantitative
and morphological insight into the crystallization of ubiquitous micellar
SDS solutions and its phase stability below room temperature
Activation of Latent HIV Using Drug-Loaded Nanoparticles
Antiretroviral therapy is currently only capable of controlling HIV replication rather than completely eradicating virus from patients. This is due in part to the establishment of a latent virus reservoir in resting CD4+ T cells, which persists even in the presence of HAART. It is thought that forced activation of latently infected cells could induce virus production, allowing targeting of the cell by the immune response. A variety of molecules are able to stimulate HIV from latency. However no tested purging strategy has proven capable of eliminating the infection completely or preventing viral rebound if therapy is stopped. Hence novel latency activation approaches are required. Nanoparticles can offer several advantages over more traditional drug delivery methods, including improved drug solubility, stability, and the ability to simultaneously target multiple different molecules to particular cell or tissue types. Here we describe the development of a novel lipid nanoparticle with the protein kinase C activator bryostatin-2 incorporated (LNP-Bry). These particles can target and activate primary human CD4+ T-cells and stimulate latent virus production from human T-cell lines in vitro and from latently infected cells in a humanized mouse model ex vivo. This activation was synergistically enhanced by the HDAC inhibitor sodium butyrate. Furthermore, LNP-Bry can also be loaded with the protease inhibitor nelfinavir (LNP-Bry-Nel), producing a particle capable of both activating latent virus and inhibiting viral spread. Taken together these data demonstrate the ability of nanotechnological approaches to provide improved methods for activating latent HIV and provide key proof-of-principle experiments showing how novel delivery systems may enhance future HIV therapy
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
Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grass.
Copyright: 2013 King et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThe fungal genus Rhynchosporium (causative agent of leaf blotch) contains several host-specialised species, including R. commune (colonising barley and brome-grass), R. agropyri (couch-grass), R. secalis (rye and triticale) and the more distantly related R. orthosporum (cocksfoot). This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.Peer reviewedFinal Published versio
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