235 research outputs found

    Effects of Isolated Hip Abductor Fatigue on Frontal Plane Knee Mechanics

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    Purpose: Anterior cruciate ligament injuries and patellofemoral pain syndrome are both common and significant injuries to the knee that have been associated with hip weakness. Prospective studies have linked the risk of experiencing either injury to alterations in the frontal plane knee angle and moment during activity. These components of knee mechanics are theorized to be affected by hip abductor weakness. The purpose of this study was to identify the effects of isolated hip abductor fatigue-induced weakness on lower extremity kinematics and kinetics in recreationally active women

    Force and EMG Comparison between a weight-bearing clinical assessment of hip strength assessment and non-weightbearing tasks

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    Purpose: Altered hip strength is a risk factor for lower extremity injury but its relationship to biomechanical dysfunction is debated. Hip strength assessment methods are criticized for using unidirectional, non-weight-bearing positions which may not be representative of athletic activity and may affect comparison to biomechanical analysis of athletic tasks. A weight-bearing task may better represent hip muscle function during these movements. The aim of this study was to identify EMG and force differences for a clinical weight-bearing method of hip strength (the squat-hold) to traditional non-weight-bearing maximal voluntary isometric contractions (MVICs) for hip abduction, extension, and external rotation. Methods: Twenty-nine healthy volunteers (23 female, 6 male; 23.3±5.8 years) performed the squat-hold, sidelying abduction, prone extension, and seated hip external rotation MVICs. The squat-hold was performed by exerting a bilateral, maximal force against a rigid strap encircling both knees in a semi-squatted position. Surface electromyography (EMG) recorded peak activation of the gluteus medius (GMed), gluteus maximus (Gmax), and tensor fascia lata (TFL) and a handheld dynamometer simultaneously measured force during all tasks. Peak activation was compared between the squat-hold and each MVIC using paired t-tests. Force was compared across tasks using a one-way ANOVA. Results: Greater force was observed during the squat-hold than the external rotation MVIC, but abduction and extension MVICs yielded greater force than the squat-hold. GMax activation was higher during the squat-hold than the external rotation task. TFL activation was higher during the abduction MVIC than the squat-hold but GMed activation was similar across tasks. Peak GMax activation was similar between the extension MVIC and squat-hold. Conclusions: Squat-hold force may have been reduced due to altered gluteal moment arms, which affected the length-tension relationship. Clinicians should consider the squat-hold as an alternative assessment of external rotation force, but should continue to assess abduction and extension force with MVICs. Researchers should examine positions optimizing length-tension relationships to better relate motor function and movement patterns

    Innovative teaching knowledge stays with users

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    Programs seeking to transform undergraduate science, technology, engineering, and mathematics courses often strive for participating faculty to share their knowledge of innovative teaching practices with other faculty in their home departments. Here, we provide interview, survey, and social network analyses revealing that faculty who use innovative teaching practices preferentially talk to each other, suggesting that greater steps are needed for information about innovative practices to reach faculty more broadly

    Context and content of teaching conversations: exploring how to promote sharing of innovative teaching knowledge between science faculty

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    Background: Change strategies may leverage interpersonal relationships and conversations to spread teaching innovations among science faculty. Knowledge sharing refers to the process by which individuals transfer information and thereby spread innovative ideas within an organization. We use knowledge sharing as a lens for identifying factors that encourage productive teaching-related conversations between individuals, characterizing the context and content of these discussions, and understanding how peer interactions may shape instructional practices. In this study, we interview 19 science faculty using innovative teaching practices about the teaching-focused conversations they have with different discussion partners. Results: This qualitative study describes characteristics of the relationship between discussion partners, what they discuss with respect to teaching, the amount of help-seeking that occurs, and the perceived impacts of these conversations on their teaching. We highlight the role of office location and course overlap in bringing faculty together and characterize the range of topics they discuss, such as course delivery and teaching strategies. We note the tendency of faculty to seek out partners with relevant expertise and describe how faculty perceive their discussion partners to influence their instructional practices and personal affect. Finally, we elaborate on how these themes vary depending on the relationship between discussion partners. Conclusions: The knowledge sharing framework provides a useful lens for investigating how various factors affect faculty conversations around teaching. Building on this framework, our results lead us to propose two hypotheses for how to promote sharing teaching knowledge among faculty, thereby identifying productive directions for further systematic inquiry. In particular, we propose that productive teaching conversations might be cultivated by fostering collaborative teaching partnerships and developing departmental structures to facilitate sharing of teaching expertise. We further suggest that social network theories and other examinations of faculty behavior can be useful approaches for researching the mechanisms that drive teaching reform

    Cancer risk in childhood-onset systemic lupus

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    INTRODUCTION: The aim of this study was to assess cancer incidence in childhood-onset systemic lupus erythematosus (SLE). METHODS: We ascertained cancers within SLE registries at 10 pediatric centers. Subjects were linked to cancer registries for the observational interval, spanning 1974 to 2009. The ratio of observed to expected cancers represents the standardized incidence ratio (SIR) or relative cancer risk in childhood-onset SLE, versus the general population. RESULTS: There were 1020 patients aged <18 at cohort entry. Most (82%) were female and Caucasian; mean age at cohort entry was 12.6 years (standard deviation (SD) = 3.6). Subjects were observed for a total of 7,986 (average 7.8) patient-years. Within this interval, only three invasive cancers were expected. However, 14 invasive cancers occurred with an SIR of 4.7, 95% confidence interval (CI) 2.6 to 7.8. Three hematologic cancers were found (two non-Hodgkin’s lymphoma, one leukemia), for an SIR of 5.2 (95% CI 1.1 to 15.2). The SIRs stratified by age group and sex, were similar across these strata. There was a trend for highest cancer occurrence 10 to 19 years after SLE diagnosis. CONCLUSIONS: These results suggest an increased cancer risk in pediatric onset SLE versus the general population. In absolute terms, this represents relatively few events. Of note, risk may be highest only after patients have transferred to adult care

    Nonlinear gyrokinetic simulations of the I-mode high confinement regime and comparisons with experimenta)

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    For the first time, nonlinear gyrokinetic simulations of I-mode plasmas are performed and compared with experiment. I-mode is a high confinement regime, featuring energy confinement similar to H-mode, but without enhanced particle and impurity particle confinement [D. G. Whyte et al., Nucl. Fusion 50, 105005 (2010)]. As a consequence of the separation between heat and particle transport, I-mode exhibits several favorable characteristics compared to H-mode. The nonlinear gyrokinetic code GYRO [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] is used to explore the effects of E × B shear and profile stiffness in I-mode and compare with L-mode. The nonlinear GYRO simulations show that I-mode core ion temperature and electron temperature profiles are more stiff than L-mode core plasmas. Scans of the input E × B shear in GYRO simulations show that E × B shearing of turbulence is a stronger effect in the core of I-mode than L-mode. The nonlinear simulations match the observed reductions in long wavelength density fluctuation levels across the L-I transition but underestimate the reduction of long wavelength electron temperature fluctuation levels. The comparisons between experiment and gyrokinetic simulations for I-mode suggest that increased E × B shearing of turbulence combined with increased profile stiffness are responsible for the reductions in core turbulence observed in the experiment, and that I-mode resembles H-mode plasmas more than L-mode plasmas with regards to marginal stability and temperature profile stiffness.United States. Department of Energy (Contract No. DE-FC02-99ER54512-CMOD)United States. Department of Energy. Office of Science (Contract No. DE-AC02- 05CH11231

    Phase II randomized preoperative window-of-opportunity study of the PI3K inhibitor pictilisib plus anastrozole compared with anastrozole alone in patients with estrogen receptor-positive breast cancer

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    Purpose: Preclinical data support a key role for the PI3K pathway in estrogen receptor-positive breast cancer and suggest that combining PI3K inhibitors with endocrine therapy may overcome resistance. This preoperative window study assessed whether adding the PI3K inhibitor pictilisib (GDC-0941) can increase the antitumor effects of anastrozole in primary breast cancer and aimed to identify the most appropriate patient population for combination therapy. Patients and Methods: In this randomized, open-label phase II trial, postmenopausal women with newly diagnosed operable estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers were recruited. Participants were randomly allocated (2:1, favoring the combination) to 2 weeks of preoperative treatment with anastrozole 1 mg once per day (n = 26) or the combination of anastrozole 1 mg with pictilisib 260 mg once per day (n = 49). The primary end point was inhibition of tumor cell proliferation as measured by change in Ki-67 protein expression between tumor samples taken before and at the end of treatment. Results: There was significantly greater geometric mean Ki-67 suppression of 83.8% (one-sided 95% CI, ≥ 79.0%) for the combination and 66.0% (95% CI, ≤ 75.4%) for anastrozole (geometric mean ratio [combination: anastrozole], 0.48; 95% CI, ≤ 0.72; P = .004). PIK3CA mutations were not predictive of response to pictilisib, but there was significant interaction between response to treatment and molecular subtype (P =.03);for patients with luminal B tumors, the combination:anastrozole geometric mean ratio of Ki-67 suppression was 0.37 (95% CI, ≤ 0.67; P = .008), whereas no significant Ki-67 response was observed for pictilisib in luminal A tumors (1.01; P = .98). Multivariable analysis confirmed Ki-67 response to the combination treatment of patients with luminal B tumors irrespective of progesterone receptor status or baseline Ki-67 expression. Conclusion: Adding pictilisib to anastrozole significantly increases suppression of tumor cell proliferation in luminal B primary breast cancer

    Reviews and syntheses: The promise of big diverse soil data, moving current practices towards future potential

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    In the age of big data, soil data are more available and richer than ever, but – outside of a few large soil survey resources – they remain largely unusable for informing soil management and understanding Earth system processes beyond the original study. Data science has promised a fully reusable research pipeline where data from past studies are used to contextualize new findings and reanalyzed for new insight. Yet synthesis projects encounter challenges at all steps of the data reuse pipeline, including unavailable data, labor-intensive transcription of datasets, incomplete metadata, and a lack of communication between collaborators. Here, using insights from a diversity of soil, data, and climate scientists, we summarize current practices in soil data synthesis across all stages of database creation: availability, input, harmonization, curation, and publication. We then suggest new soil-focused semantic tools to improve existing data pipelines, such as ontologies, vocabulary lists, and community practices. Our goal is to provide the soil data community with an overview of current practices in soil data and where we need to go to fully leverage big data to solve soil problems in the next century

    Experimental Infection of Cynomolgus Macaques (Macaca fascicularis) with Aerosolized Monkeypox Virus

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    Monkeypox virus (MPXV) infection in humans results in clinical symptoms very similar to ordinary smallpox. Aerosol is a route of secondary transmission for monkeypox, and a primary route of smallpox transmission in humans. Therefore, an animal model for aerosol exposure to MPXV is needed to test medical countermeasures. To characterize the pathogenesis in cynomolgus macaques (Macaca fascicularis), groups of macaques were exposed to four different doses of aerosolized MPXV. Blood was collected the day before, and every other day after exposure and assessed for complete blood count (CBC), clinical chemistry analysis, and quantitative PCR. Macaques showed mild anorexia, depression, and fever on day 6 post-exposure. Lymphadenopathy, which differentiates monkeypox from smallpox, was observed in exposed macaques around day 6 post-exposure. CBC and clinical chemistries showed abnormalities similar to human monkeypox cases. Whole blood and throat swab viral loads peaked around day 10, and in survivors, gradually decreased until day 28 post-exposure. Survival was not dose dependent. As such, doses of 4×104 PFU, 1×105 PFU, or 1×106 PFU resulted in lethality for 70% of the animals, whereas a dose of 4×105 PFU resulted in 85% lethality. Overall, cynomolgus macaques exposed to aerosolized MPXV develop a clinical disease that resembles that of human monkeypox. These findings provide a strong foundation for the use of aerosolized MPXV exposure of cynomolgus macaques as an animal model to test medical countermeasures against orthopoxviruses

    SoDaH: the SOils DAta Harmonization database, an open-source synthesis of soil data from research networks, version 1.0

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    Data collected from research networks present opportunities to test theories and develop models about factors responsible for the long-term persistence and vulnerability of soil organic matter (SOM). Synthesizing datasets collected by different research networks presents opportunities to expand the ecological gradients and scientific breadth of information available for inquiry. Synthesizing these data is challenging, especially considering the legacy of soil data that have already been collected and an expansion of new network science initiatives. To facilitate this effort, here we present the SOils DAta Harmonization database (SoDaH; https://lter.github.io/som-website, last access: 22 December 2020), a flexible database designed to harmonize diverse SOM datasets from multiple research networks. SoDaH is built on several network science efforts in the United States, but the tools built for SoDaH aim to provide an open-access resource to facilitate synthesis of soil carbon data. Moreover, SoDaH allows for individual locations to contribute results from experimental manipulations, repeated measurements from long-term studies, and local- to regional-scale gradients across ecosystems or landscapes. Finally, we also provide data visualization and analysis tools that can be used to query and analyze the aggregated database. The SoDaH v1.0 dataset is archived and available at https://doi.org/10.6073/pasta/9733f6b6d2ffd12bf126dc36a763e0b4 (Wieder et al., 2020)
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