1,551 research outputs found

    The effect of mountain bike wheel size on Cross-Country performance

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    The purpose of this study was to determine the influence of different wheel size diameters on indicators of cross-country mountain bike time trial performance. Nine competitive male mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) performed 1 lap of a 3.48 km mountain bike (MTB) course as fast as possible on 26″, 27.5″ and 29″ wheeled MTB. Time (s), mean power (W), cadence (revs · min−1) and velocity (km · h−1) were recorded for the whole lap and during ascent and descent sections. One-way repeated measure ANOVA was used to determine significant differences. Results revealed no significant main effects for any variables by wheel size during all trials, with the exception of cadence during the descent (F(2, 16) = 8.96; P = .002; P2 = .53). Post hoc comparisons revealed differences lay between the 26″ and 29″ wheels (P = .02). The findings indicate that wheel size does not significantly influence performance during cross-country when ridden by trained mountain bikers, and that wheel choice is likely due to personal choice or sponsorship commitments

    British Association for Biological Anthropology and Osteoarchaeology: Equality, Diversity and Inclusion Race Equality Review

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    Racism continues to be widespread, subtle and often ignored or selectively attended to within organisations. This review sought to evaluate the British Association for Biological Anthropology and Osteoarchaeology (BABAO)’s existing race equality practices, to further support its movement towards becoming an antiracist organisation. The review arose from a commitment by BABAO to interrogate its current structures and redress problematic cultures within the organisation, following a member of colour expressing concerns. In itself, this provides an encouraging example both of the reflexivity of the organisation and the power of a single voice. Through focus groups and surveys, insights were gained with regards to the organisational culture and in response to issues concerning equality, diversity and inclusion (EDI), particularly regarding the need for BABAO to become a more racially literate organisation. The review attempted to glean members’ understanding of anti-racism and how some cultures within the organisation may be racially exclusive or marginalising. In addition to this, the reviewers engaged with stakeholders about where areas could be improved within BABAO in continuing their work towards becoming a racially cognizant organisation. Responses gleaned from the focus groups and survey questionnaire distributed to members revealed that BABAO as an organisation has made some tentative first steps towards race equality, but has some way to go. The paucity of Black, Asian and Minority Ethnic members made gaining perspectives a challenge in relation to experiences of racial discrimination. In itself, this is an indicator that inclusion is an area for growth and reflection. Other key findings included issues with reporting structures and governance processes, with a need for strong and courageous leadership to drive forward conversations around race and racism; a need for training and work to improve racial literacy of the organisation and its members; and a lack of engagement and participation from current members in EDI issues. Nevertheless, the review also indicated that the organisation has made significant strides towards establishing anti-racist practices and are working diligently to engage all members in this endeavour. To this end, the conclusions and recommendations provided aim to enhance current action and further enable BABAO to achieve an anti-racist, inclusive organisational culture.Based on the considerations outlined throughout the report, there were twenty-seven recommendations made. They reflect the need to build a foundation of awareness, understanding and safety upon which to develop a culture of learning, reflection and shared, collective action. High-level recommendations are synthesised below, with further detail in the body of the report

    Efficacy of novel recombinant fowlpox vaccine against recent Mexican H7N3 highly pathogenic avian influenza virus

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    Since 2012, H7N3 highly pathogenic avian influenza (HPAI) has produced negative economic and animal welfare impacts on poultry in central Mexico. In the present study, chickens were vaccinated with two different recombinant fowlpox virus vaccines (rFPV-H7/3002 with 2015 H7 hemagglutinin [HA] gene insert, and rFPV-H7/2155 with 2002 H7 HA gene insert), and were then challenged three weeks later with H7N3 HPAI virus (A/chicken/Jalisco/CPA-37905/2015). The rFPV-H7/3002 vaccine conferred 100% protection against mortality and morbidity, and significantly reduced virus shed titers from the respiratory and gastrointestinal tracts. In contrast, 100% of sham and rFPV-H7/2155 vaccinated birds shed virus at higher titers and died within 4 days. Pre- (15/20) and post- (20/20) challenge serum of birds vaccinated with rFPV-H7/3002 had antibodies detectable by hemagglutination inhibition (HI) assay using challenge virus antigen. However, only a few birds (3/20) in the rFPV-H7/2155 vaccinated group had antibodies that reacted against the challenge strain but all birds had antibodies that reacted against the homologous vaccine antigen (A/turkey/Virginia/SEP-66/2002) (20/20). One possible explanation for differences in vaccines efficacy is the antigenic drift between circulating viruses and vaccines. Molecular analysis demonstrated that the Mexican H7N3 strains have continued to rapidly evolve since 2012. In addition, we identified in silico three potential new N-glycosylation sites on the globular head of the H7 HA of A/chicken/Jalisco/CPA-37905/2015 challenge virus, which were absent in 2012 H7N3 outbreak virus. Our results suggested that mutations in the HA antigenic sites including increased glycosylation sites, accumulated in the new circulating Mexican H7 HPAIV strains, altered the recognition of neutralizing antibodies from the older vaccine strain rFPV-H7/2155. Therefore, the protective efficacy of novel rFPV-H7/3002 against recent outbreak Mexican H7N3 HPAIV confirms the importance of frequent updating of vaccines seed strains for long-term effective control of H7 HPAI virus

    Generalizing Common Tasks in Automated Skin Lesion Diagnosis

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    Reversing Blood Flows Act through klf2a to Ensure Normal Valvulogenesis in the Developing Heart

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    Heart valve anomalies are some of the most common congenital heart defects, yet neither the genetic nor the epigenetic forces guiding heart valve development are well understood. When functioning normally, mature heart valves prevent intracardiac retrograde blood flow; before valves develop, there is considerable regurgitation, resulting in reversing (or oscillatory) flows between the atrium and ventricle. As reversing flows are particularly strong stimuli to endothelial cells in culture, an attractive hypothesis is that heart valves form as a developmental response to retrograde blood flows through the maturing heart. Here, we exploit the relationship between oscillatory flow and heart rate to manipulate the amount of retrograde flow in the atrioventricular (AV) canal before and during valvulogenesis, and find that this leads to arrested valve growth. Using this manipulation, we determined that klf2a is normally expressed in the valve precursors in response to reversing flows, and is dramatically reduced by treatments that decrease such flows. Experimentally knocking down the expression of this shear-responsive gene with morpholine antisense oligonucleotides (MOs) results in dysfunctional valves. Thus, klf2a expression appears to be necessary for normal valve formation. This, together with its dependence on intracardiac hemodynamic forces, makes klf2a expression an early and reliable indicator of proper valve development. Together, these results demonstrate a critical role for reversing flows during valvulogenesis and show how relatively subtle perturbations of normal hemodynamic patterns can lead to both major alterations in gene expression and severe valve dysgenesis

    Reliability and Criterion Validity of Knee Frontal Plane Projection Angles Measured Using the Technique Application

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    Context: Abnormal knee frontal plane projection angles (FPPA) during movement have been associated with patellofemoral pain (PFP). As such, clinicians are interested in valid and reliable instruments suitable for broad-based clinical use that allow them to objectively measure such variables. Therefore, the purpose of the current study was to examine the criterion validity and reliability of knee FPPA measures obtained by clinicians using a free tablet application called Technique. Design: validity/reliability study Methods: To examine validity, the same raters measured ten, two-dimensional criterion reference angles at the first testing session. To examine reliability, the knee FPPA of sixteen subjects was measured by 6 raters (3 physical therapists and 3 student physical therapists) on two separate occasions while performing a single-limb stepdown task. Validity was investigated by calculating the 95% limits of agreement (LA), mean absolute differences, and Bland-Altman plots. Reliability was examined by calculating intraclass correlation coefficients (ICC) and the standard error of measure (SEM). Results: For validity, the mean absolute difference between rater and criterion reference angle measures ranged from 0.20 to 0.90 degrees. 95% of expected errors between rater and criterion reference angle measures were 2.04 degrees or less. For reliability, the ICC values for inter- and intrarater reliability were excellent ranging from 0.994 to 0.998 with SEM ranging from 0.44 to 0.84 degrees. Conclusions: These findings indicate that knee FPPA measures obtained during a single-limb stepdown task using the Technique tablet application are valid and reliable, and suitable for clinical use

    Treetop: A Shiny-based application and R package for extracting forest information from LiDAR data for ecologists and conservationists

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    Individual tree detection (ITD) and crown delineation are two of the most relevant methods for extracting detailed and reliable forest information from LiDAR (Light Detection and Ranging) datasets. However, advanced computational skills and specialized knowledge have been normally required to extract forest information from LiDAR.The development of accessible tools for 3D forest characterization can facilitate rapid assessment by stakeholders lacking a remote sensing background, thus fostering the practical use of LiDAR datasets in forest ecology and conservation. This paper introduces the treetop application, an open-source web-based and R package LiDAR analysis tool for extracting forest structural information at the tree level, including cutting-edge analyses of properties related to forest ecology and management.We provide case studies of how treetop can be used for different ecological applications, within various forest ecosystems. Specifically, treetop was employed to assess post-hurricane disturbance in natural temperate forests, forest homogeneity in industrial forest plantations and the spatial distribution of individual trees in a tropical forest.treetop simplifies the extraction of relevant forest information for forest ecologists and conservationists who may use the tool to easily visualize tree positions and sizes, conduct complex analyses and download results including individual tree lists and figures summarizing forest structural properties. Through this open-source approach, treetop can foster the practical use of LiDAR data among forest conservation and management stakeholders and help ecological researchers to further understand the relationships between forest structure and function.The authors thank Nicholas L. Crookston for co‐developing the web‐LiDAR treetop tool, and the two anonymous reviewers for their helpful suggestions on the first version of the manuscript. This study is based on the work supported by the Department of Defence Strategic Environmental Research and Development Program (SERDP) under grants No. RC‐2243, RC19‐1064 and RC20‐1346 and USDA Forest Service (grand No. PRO00031122

    New targets for therapy in breast cancer: Mammalian target of rapamycin (mTOR) antagonists

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    Mammalian target of rapamycin (mTOR) is a serine-threonine kinase member of the cellular phosphatidylinositol 3-kinase (PI3K) pathway, which is involved in multiple biologic functions such as transcriptional and translational control. mTOR is a downstream mediator in the PI3K/Akt signaling pathway and plays a critical role in cell survival. In breast cancer this pathway can be activated by membrane receptors, including the HER (or ErbB) family of growth factor receptors, the insulin-like growth factor receptor, and the estrogen receptor. There is evidence suggesting that Akt promotes breast cancer cell survival and resistance to chemotherapy, trastuzumab, and tamoxifen. Rapamycin is a specific mTOR antagonist that targets this pathway and blocks the downstream signaling elements, resulting in cell cycle arrest in the G(1 )phase. Targeting the Akt/PI3K pathway with mTOR antagonists may increase the therapeutic efficacy of breast cancer therapy
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