122 research outputs found
The sensitivity of the vortex filament method to different reconnection models
We present a detailed analysis on the effect of using different algorithms to
model the reconnection of vortices in quantum turbulence, using the
thin-filament approach. We examine differences between four main algorithms for
the case of turbulence driven by a counterflow. In calculating the velocity
field we use both the local induction approximation (LIA) and the full
Biot-Savart integral. We show that results of Biot-Savart simulations are not
sensitive to the particular reconnection method used, but LIA results are.Comment: 9 pages, 9 figure
Tree method for quantum vortex dynamics
We present a numerical method to compute the evolution of vortex filaments in
superfluid helium. The method is based on a tree algorithm which considerably
speeds up the calculation of Biot-Savart integrals. We show that the
computational cost scales as Nlog{(N) rather than N squared, where is the
number of discretization points. We test the method and its properties for a
variety of vortex configurations, ranging from simple vortex rings to a
counterflow vortex tangle, and compare results against the Local Induction
Approximation and the exact Biot-Savart law.Comment: 12 pages, 10 figure
Framing the concept of satellite remote sensing essential biodiversity variables: challenges and future directions
Although satellite-based variables have for long been expected to be key components to a unified and global biodiversity monitoring strategy, a definitive and agreed list of these variables still remains elusive. The growth of interest in biodiversity variables observable from space has been partly underpinned by the development of the essential biodiversity variable (EBV) framework by the Group on Earth Observations – Biodiversity Observation Network, which itself was guided by the process of identifying essential climate variables. This contribution aims to advance the development of a global biodiversity monitoring strategy by updating the previously published definition of EBV, providing a definition of satellite remote sensing (SRS) EBVs and introducing a set of principles that are believed to be necessary if ecologists and space agencies are to agree on a list of EBVs that can be routinely monitored from space. Progress toward the identification of SRS-EBVs will require a clear understanding of what makes a biodiversity variable essential, as well as agreement on who the users of the SRS-EBVs are. Technological and algorithmic developments are rapidly expanding the set of opportunities for SRS in monitoring biodiversity, and so the list of SRS-EBVs is likely to evolve over time. This means that a clear and common platform for data providers, ecologists, environmental managers, policy makers and remote sensing experts to interact and share ideas needs to be identified to support long-term coordinated actions
The effects of wearing an Ankle Stabilizing Orthosis (ASO) Ankle Brace on ankle joints kinetics and kinematics during a basketball rebounding task
Following an ankle injury, athletes sometimes brace the injured ankle in hopes of minimizing the likelihood of suffering a recurring injury. This study aims to evaluate the effects of wearing an Ankle Stabilizing Orthosis (ASO) ankle brace unilaterally on the dominant side on bilateral ankle joint kinetics and kinematics and peroneus longus EMG activity. Since a significant proportion of ankle injuries in basketball occur during rebounding, data was collected during a simulated rebounding task. Rebounding is defined as the act of retrieving a missed shot attempt. Subjects oftentimes jump vertically to acquire the basketball as it rebounds from the backboard or rim. Sixteen subjects participated in the study (11 males, 5 females; mean age = 26.94 years, SD = 5.32; mean height 1.72 m, SD = 0.08; mean weight 73.95 kg, SD = 13.68). Participants completed the rebounding task in braced (ASO) and unbraced (UB) conditions. Ankle and foot inversion angles, ankle inversion moments and peroneus longus EMG activity were recorded and analysed to determine the effects of wearing an ankle brace unilaterally. In the dominant limb, when compared to UB, ASO reduced ankle and foot inversion, and increased ankle inversion moments. No significant differences were observed in peroneus longus EMG activity. In the non-dominant limb, no significant differences were observed for any of the parameters. These results suggest that wearing an ASO ankle brace on the dominant ankle reduces maximum ankle and foot inversion angles without posing an increased risk to the unbraced leg. However, the increased ankle inversion moments in the braced ankle suggest that there are adjustments regarding force distribution, perhaps due to the restricted range of motion.</p
Expressão gênica de caspases 3 e 8 em timo e baço de ratas recém-desmamadas e imunossuprimidas por glicocorticóide
Toward a Multifaceted Heuristic of Digital Reading to Inform Assessment, Research, Practice, and Policy
In this commentary, the author explores the tension between almost 30 years of work that has embraced increasingly complex conceptions of digital reading and recent studies that risk oversimplifying digital reading as a singular entity analogous with reading text on a screen. The author begins by tracing a line of theoretical and empirical work that both informs and complicates our understanding of digital literacy and, more specifically, digital reading. Then, a heuristic is proposed to systematically organize, label, and define a multifaceted set of increasingly complex terms, concepts, and practices that characterize the spectrum of digital reading experiences. Research that informs this heuristic is used to illustrate how more precision in defining digital reading can promote greater clarity across research methods and advance a more systematic study of promising digital reading practices. Finally, the author discusses implications for assessment, research, practice, and policy
Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets
Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources
Níveis iônicos e enzimáticos de cutias (Dasyprocta sp.) hígidas, criadas em cativeiro, influência do sexo e da idade
Social Media, Gender and the Mediatisation of War: Exploring the German Armed Forces’ Visual Representation of the Afghanistan Operation on Facebook
Studies on the mediatisation of war point to attempts of governments to regulate the visual perspective of their involvements in armed conflict – the most notable example being the practice of ‘embedded reporting’ in Iraq and Afghanistan. This paper focuses on a different strategy of visual meaning-making, namely, the publication of images on social media by armed forces themselves. Specifically, we argue that the mediatisation of war literature could profit from an increased engagement with feminist research, both within Critical Security/Critical Military Studies and within Science and Technology Studies that highlight the close connection between masculinity, technology and control. The article examines the German military mission in Afghanistan as represented on the German armed forces’ official Facebook page. Germany constitutes an interesting, and largely neglected, case for the growing literature on the mediatisation of war: its strong antimilitarist political culture makes the representation of war particularly delicate. The paper examines specific representational patterns of Germany’s involvement in Afghanistan and discusses the implications which arise from what is placed inside the frame of visibility and what remains out of its view
Características químicas do lixiviado na fase de enraizamento de estacas de cacau em substratos adubados com fósforo
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