465 research outputs found

    Methodological quality of systematic reviews of animal studies: a survey of reviews of basic research

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    BACKGROUND: Systematic reviews can serve as a tool in translation of basic life sciences research from laboratory to human research and healthcare. The extent to which reviews of animal research are systematic and unbiased is not known. METHODS: We searched, without language restrictions, Medline, Embase, bibliographies of known reviews (1996–2004) and contacted experts to identify citations of reviews of basic science literature which, as a minimum, performed search of a publicly available resource. From these we identified reviews of animal studies where laboratory variables were measured or where treatments were administered to live animals to examine their effects, and compared them with reviews of bench studies in which human or animal tissues, cell systems or organ preparations were examined in laboratories to better understand mechanisms of diseases. RESULTS: Systematic reviews of animal studies often lacked methodological features such as specification of a testable hypothesis (9/30, 30%); literature search without language restriction (8/30, 26.6%); assessment of publication bias (5/30, 16.6%), study validity (15/30, 50%) and heterogeneity (10/30, 33.3%); and meta-analysis for quantitative synthesis (12/30, 40%). Compared to reviews of bench studies, they were less prone to bias as they specified the question (96.6% vs. 80%, p = 0.04), searched multiple databases (60% vs. 26.6%, p = 0.01), assessed study quality (50% vs. 20%, p = 0.01), and explored heterogeneity (33.3% vs. 2.2%, p = 0.001) more often. CONCLUSION: There seems to be a gradient of frequency of methodological weaknesses among reviews: Attempted systematic reviews of whole animal research tend to be better than those of bench studies, though compared to systematic reviews of human clinical trials they are apparently poorer. There is a need for rigour when reviewing animal research

    Russian Artistic Gymnastics as a Sports Tourism Product: Some Observations and a Research Agenda

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    Tourism and its importance to the Russian Federation are very much in the headlines at present. Considering the huge investment made in facilities for the Winter Olympics, the building of new sports facilities for such mega events as the Football World Cup, and the status of St Petersburg as a candidate city for the 2028 Olympics, it is clear that Russia has long term plans to attract visitors to their sporting events. The purpose of this paper is to develop a research agenda to explore the potential of artistic gymnastics, a sport in which the Russian Federation has excelled for many years, as an agent of tourism development. The paper will take a case study approach, considering the nature of fandom and identifying features of artistic gymnastics as cultural heritage and sports tourism product. The national and international environment within which it is set are examined, prior to the development of a research agenda. A detailed review of literature on the historic, current and emerging trends in Russian artistic gymnastics; the place of artistic gymnastics in tourism development and sports tourism in Russia will be carried out. The paper’s findings will include considerations of: • The nature of gymnastics fandom, both in Russia and internationally • The nature of sports tourism development in the Russian Federation • The nature of gymnastics as a sport and its competition cycle • Artistic gymnastics as cultural heritage, and its potential as an autonomous means of promoting Russian national identity • The relationship between Russia’s sometimes fading gymnastics competition results, and its potential to leverage the sport for tourism interest • The potential for tourism product development linked to artistic gymnastics in the Russian Federation. The paper contributes to the literature on the nature of sports tourism as it relates to artistic gymnastics in the Russian Federation in particular

    Understanding cycle tourism experiences at the Tour Down Under

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    Sport tourism experiences are subjective and emotional, laden with symbolic meaning. This study explores the experiences of participants who adopted the multiple roles of both an active participant and event spectator, within the parameters of one chosen sporting event. A professional cycling race event, the Tour Down Under in South Australia was chosen for this investigation, and 20 face-to-face individual interviews were conducted with cycle tourists. The three main themes emerging from the data were the interaction of people and temporary spaces on a sport tourism ‘stage’; the co-creation of authentic personal experiences and meanings; and identity reinforcement and the development of a sense of belonging. Consequently, a model for understanding sport event tourism experiences is proposed. The findings suggest that providing tourists with authentic and memorable experiences lies at the heart of what constitutes sport tourism. Whilst the results demonstrate that cycling events provide the individual with a sense of belonging or membership to a wider social group, they also illustrate that there is a continued need for more focused and nuanced approaches towards understanding sport tourism experiences that reflect the ever-increasing diversity and complexity of the interaction between sport, events and tourism

    Chemical Classification of Spherules Recovered From The Pacific Ocean Site of The CNEOS 2014-01-08 (IM1) Bolide

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    We have conducted an extensive towed-magnetic-sled survey during the period of June 14-28, 2023, over the seafloor about 85 km north of Manus Island, Papua New Guinea, centered around the calculated path of the bolide CNEOS 2014-01-08 (IM1). We found about 850 spherules of diameter 0.1-1.3 millimeters in our samples. The samples were analyzed by micro-XRF, Electron Probe Microanalyzer and ICP Mass spectrometry. Here we report major and trace element compositions of the samples and classify spherules based on that analysis. We identified 78% of the spherules as primitive, in that their compositions have not been affected by planetary differentiation. We divided these into four groups corresponding to previously described cosmic spherule types. The remaining 22% appear to all reflect planetary igneous differentiation and are all different from previously described spherules. We call them D-type spherules. A portion of the D-spherules show an excess of Be, La and U, by up to three orders of magnitude relative to the solar system standard of CI chondrites. Detailed mass spectroscopy of 12 of these BeLaU-type spherules, the population of which may constitute up to ~10% of our entire collected sample, suggests that they are derived from material formed by planetary igneous fractionation. Their chemical composition is unlike any known solar system material. We compare these compositions to known differentiated bodies in the solar system and find them similar to evolved planetary materials - with lunar KREEP the closest in terms of its trace element enrichment pattern, but unusual in terms of their elevated CI-normalized incompatible elements. The BeLaU-type spherules reflect a highly differentiated, extremely evolved composition of an unknown source.Comment: 26 pages, 20 figures, submitted for publicatio

    Cell Invasion by Neisseria meningitidis Requires a Functional Interplay between the Focal Adhesion Kinase, Src and Cortactin

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    Entry of Neisseria meningitidis (the meningococcus) into human brain microvascular endothelial cells (HBMEC) is mediated by fibronectin or vitronectin bound to the surface protein Opc forming a bridge to the respective integrins. This interaction leads to cytoskeletal rearrangement and uptake of meningococci. In this study, we determined that the focal adhesion kinase (FAK), which directly associates with integrins, is involved in integrin-mediated internalization of N. meningitidis in HBMEC. Inhibition of FAK activity by the specific FAK inhibitor PF 573882 reduced Opc-mediated invasion of HBMEC more than 90%. Moreover, overexpression of FAK mutants that were either impaired in the kinase activity or were not capable of autophosphorylation or overexpression of the dominant-negative version of FAK (FRNK) blocked integrin-mediated internalization of N. meningitidis. Importantly, FAK-deficient fibroblasts were significantly less invaded by N. meningitidis. Furthermore, N. meningitidis induced tyrosine phosphorylation of several host proteins including the FAK/Src complex substrate cortactin. Inhibition of cortactin expression by siRNA silencing and mutation of critical amino acid residues within cortactin, that encompass Arp2/3 association and dynamin binding, significantly reduced meningococcal invasion into eukaryotic cells suggesting that both domains are critical for efficient uptake of N. meningitidis into eukaryotic cells. Together, these results indicate that N. meningitidis exploits the integrin signal pathway for its entry and that FAK mediates the transfer of signals from activated integrins to the cytoskeleton. A cooperative interplay between FAK, Src and cortactin then enables endocytosis of N. meningitidis into host cells

    Gene products of chromosome 11q and their association with CCND1 gene amplification and tamoxifen resistance in premenopausal breast cancer

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    Introduction: The amplification event occurring at chromosome locus 11q13, reported in several different cancers, includes a number of potential oncogenes. We have previously reported amplification of one such oncogene, namely CCND1, to be correlated with an adverse effect of tamoxifen in premenopausal breast cancer patients. Over-expression of cyclin D-1 protein, however, confers tamoxifen resistance but not a tamoxifen-induced adverse effect. Potentially, co-amplification of an additional 11q13 gene, with a resulting protein over-expression, is required to cause an agonistic effect. Moreover, during 11q13 amplification a deletion of the distal 11q region has been described. In order to assess the potential impact of the deletion we examined a selected marker for this event. Method: Array comparative genomic hybridization analysis was employed to identify and confirm changes in the gene expression of a number of different genes mapping to the 11q chromosomal region, associated with CCND1 amplification. The subsequent protein expression of these candidate genes was then examined in a clinical material of 500 primary breast cancers from premenopausal patients who were randomly assigned to either tamoxifen or no adjuvant treatment. The protein expression was also compared with gene expression data in a subset of 56 breast cancer samples. Results: Cortactin and FADD (Fas-associated death domain) over-expression was linked to CCND1 amplification, determined by fluorescence in situ hybridization, but was not associated with a diminished effect of tamoxifen. However, deletion of distal chromosome 11q, defined as downregulation of the marker Chk1 (checkpoint kinase 1), was associated with an impaired tamoxifen response, and interestingly with low proliferative breast cancer of low grade. For Pak1 (p21-activated kinase 1) and cyclin D-1 the protein expression corresponded to the gene expression data. Conclusions: The results indicate that many 11q13 associated gene products are over-expressed in conjunction with cyclin D-1 but not linked to an agonistic effect of tamoxifen. Finally, the deletion of distal 11q, linked to 11q13 amplification, might be an important event affecting breast cancer outcome and tamoxifen response

    L-Plastin nanobodies perturb matrix degradation, podosome formation, stability and lifetime in THP-1 macrophages

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    Podosomes are cellular structures acting as degradation ‘hot-spots’ in monocytic cells. They appear as dot-like structures at the ventral cell surface, enriched in F-actin and actin regulators, including gelsolin and L-plastin. Gelsolin is an ubiquitous severing and capping protein, whereas L-plastin is a leukocyte-specific actin bundling protein. The presence of the capping protein CapG in podosomes has not yet been investigated. We used an innovative approach to investigate the role of these proteins in macrophage podosomes by means of nanobodies or Camelid single domain antibodies. Nanobodies directed against distinct domains of gelsolin, L-plastin or CapG were stably expressed in macrophage-like THP-1 cells. CapG was not enriched in podosomes. Gelsolin nanobodies had no effect on podosome formation or function but proved very effective in tracing distinct gelsolin populations. One gelsolin nanobody specifically targets actin-bound gelsolin and was effectively enriched in podosomes. A gelsolin nanobody that blocks gelsolin-G-actin interaction was not enriched in podosomes demonstrating that the calcium-activated and actin-bound conformation of gelsolin is a constituent of podosomes. THP-1 cells expressing inhibitory L-plastin nanobodies were hampered in their ability to form stable podosomes. Nanobodies did not perturb Ser5 phosphorylation of L-plastin although phosphorylated L-plastin was highly enriched in podosomes. Furthermore, nanobody-induced inhibition of L-plastin function gave rise to an irregular and unstable actin turnover of podosomes, resulting in diminished degradation of the underlying matrix. Altogether these results indicate that L-plastin is indispensable for podosome formation and function in macrophages
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