362 research outputs found
Timing of Nordic Hamstring Exercise in Youth Soccer Players to Reduce Injury
The Nordic hamstring exercise (NHE) has been demonstrated to be an effective strength exercise to help mitigate the risk of hamstring injury in soccer players. It is a component of the FIFA 11+ grassroots injury prevention program, which is a series of warm-up exercises designed to be administered in large groups and at minimal cost. Recent evidence in adults suggests that the acute fatigue associated with the NHE may increase the risk of injury during training, causing some to suggest moving the NHE until the end of training. PURPOSE: To determine whether this same level of fatigue persists in young soccer players, where training intensities and volumes are often much lower than in adults. METHODS: We designed a field-based crossover experimental study where youth soccer players completed two experimental sessions in a randomized manner. Participants included 18 youth players (mean ± SD: males, n=18; age 15.5 ± 0.7 years, height 1.77 ± 0.13 m, weight 66.4 ± 10.8 kg) participating in the Major League Soccer (MLS) Next player development pathway in Phoenix, USA. One session included the NHE as part of a standardized warm-up prior to a 75-minute standardized training session, and the alternative session incorporated the NHE at the end of the training session. Maximal hamstring force was measured at baseline, post-warm-up, and after completion of training. RESULTS: There was no interaction, condition, or main effect of NHE timing as indicated by maximal force output in the left (p \u3e 0.69) and right leg (p \u3e 0.65). CONCLUSION: Our findings add to the growing body of literature with regard to lower-limb fatigue profiles and adolescent soccer players, as well as suggest youth soccer coaches should not be concerned with the timing of these interventions, allowing them to focus instead on adherence and player buy-in
The effectiveness of the flipped classroom for students with learning disabilities in an Algebra I resource setting
The purpose of this study was: (a) to examine the effectiveness of using the flipped classroom model to improve the academic scores of students with a specific learning disabilities (SLD), (b) to examine the effectiveness of using the flipped classroom to improve rates of homework completion by students with a SLD and (c) to evaluate student satisfaction and perception of the flipped classroom intervention. Five high school students, four males and one female, with a SLD participated in the study. A single subject ABAB design was used. During the baseline phases, students received Algebra I instruction through a traditional classroom model. Class time was utilized for direct instruction and practice problems were assigned for homework. During the intervention, students received Algebra I instruction through the flipped classroom model. Instructional videos and guided note sheets were assigned for homework and class time was used for collaborative practice activities. Homework completion and daily assessment scores were recorded across all phases. Results show that students improved their rate of homework completion during the intervention phases. The student satisfaction survey suggests that students enjoyed the flipped classroom and preferred it to traditional instruction models. Further research is suggested investigating the academic outcomes of the flipped classroom for students with SLD
Strategy dynamics in groups of prey
Group living is a widespread and ubiquitous phenomenon in the animal kingdom. Animals in groups are subjected to numerous costs and benefits. Of the benefits, increased protection from predators is the most theoretically and experimentally researched. Three ``principal'' effects explain the anti-predation benefits of grouping: collective vigilance, dilution of risk, and the confusion effect. In this thesis, new theoretical models are developed to study the behaviours that emerge from groups of prey. Using a mathematical approach, this research analyses how the principal anti-predation effects interact to influence the behaviours of grouping animals.
Through an analytical approach, the first part of this thesis examines the role of anti-predation effects on individuals with discrete behavioural choices. The outcomes of group interactions are classified by exact analytical conditions. Results are provided which show how factors relating to predation risk, such as group size, affect anti-predator behaviours.
Another component of this research uses field data to assess the theoretical results that are presented. The relative influence of each anti-predation effect, and how the anti-predation effect interact to influence individual behaviours within groups is assessed. Consideration of how predation risk and other factors of grouping affect behaviours is also analysed.
The final section of research considers highly flexible and continuous anti-predator behaviours. This shift in theory is relevant in groups of prey, for example in models of vigilance. Intuitive results are presented, and conditions are provided which determine qualitatively distinct behavioural dynamics when groups are characterised by continuous behaviours. Equivalences to the discrete behaviour analogue case are shown. It is also shown that individuals may choose neither of the discrete behavioural options. Conditions are derived which specify the occurrence of multiple distinct anti-predator behaviours emerging from a group initially composed of one behaviour, and when the reserve process occurs
HRM and the COVID-19 Pandemic: How can we stop making a bad situation worse?
This provocation argues that the COVID-19 pandemic has exposed deep labour market inequalities. Partially underpinning these inequalities are human resource management (HRM) theories and practices which encourage and legitimise the commodification of labour. Workers whose jobs have been commodified have suffered disproportionately during the pandemic. While HRM is not wholly responsible for this suffering it is important for those of us involved in researching, teaching and practicing HRM to reflect on the ways in which what we do has made a bad situation worse so that we can do better in the future
Role of orexin A signaling in dietary palmitic acid-activated microglial cells
AbstractExcess dietary saturated fatty acids such as palmitic acid (PA) induce peripheral and hypothalamic inflammation. Hypothalamic inflammation, mediated in part by microglial activation, contributes to metabolic dysregulation. In rodents, high fat diet-induced microglial activation results in nuclear translocation of nuclear factor-kappa B (NFκB), and increased central pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The hypothalamic neuropeptide orexin A (OXA, hypocretin 1) is neuroprotective in brain. In cortex, OXA can also reduce inflammation and neurodegeneration through a microglial-mediated pathway. Whether hypothalamic orexin neuroprotection mechanisms depend upon microglia is unknown. To address this issue, we evaluated effects of OXA and PA on inflammatory response in immortalized murine microglial and hypothalamic neuronal cell lines. We demonstrate for the first time in microglial cells that exposure to PA increases gene expression of orexin-1 receptor but not orexin-2 receptor. Pro-inflammatory markers IL-6, TNF-α, and inducible nitric oxide synthase in microglial cells are increased following PA exposure, but are reduced by pretreatment with OXA. The anti-inflammatory marker arginase-1 is increased by OXA. Finally, we show hypothalamic neurons exposed to conditioned media from PA-challenged microglia have increased cell survival only when microglia were pretreated with OXA. These data support the concept that OXA may act as an immunomodulatory regulator of microglia, reducing pro-inflammatory cytokines and increasing anti-inflammatory factors to promote a favorable neuronal microenvironment
Neuroinflammation and Brain Health Risks in Veterans Exposed to Burn Pit Toxins
Military burn pits, used for waste disposal in combat zones, involve the open-air burning of waste materials, including plastics, metals, chemicals, and medical waste. The pits release a complex mixture of occupational toxic substances, including particulate matter (PM), volatile organic compounds (VOCs), heavy metals, dioxins, and polycyclic aromatic hydrocarbons (PAHs). Air pollution significantly impacts brain health through mechanisms involving neuroinflammation. Pollutants penetrate the respiratory system, enter the bloodstream, and cross the blood-brain barrier (BBB), triggering inflammatory responses in the central nervous system (CNS). Chronic environmental exposures result in sustained inflammation, oxidative stress, and neuronal damage, contributing to neurodegenerative diseases and cognitive impairment. Veterans exposed to burn pit toxins are particularly at risk, reporting higher rates of respiratory issues, neurological conditions, cognitive impairments, and mental health disorders. Studies demonstrate that Veterans exposed to these toxins have higher rates of neuroinflammatory markers, accelerated cognitive decline, and increased risks of neurodegenerative diseases. This narrative review synthesizes the research linking airborne pollutants such as PM, VOCs, and heavy metals to neuroinflammatory processes and cognitive effects. There is a need for targeted interventions to mitigate the harmful and escalating effects of environmental air pollution exposures on the CNS, improving public health outcomes for vulnerable populations, especially for Veterans exposed to military burn pit toxins
Rapid Self‐Integrating, Injectable Hydrogel for Tissue Complex Regeneration
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112267/1/adhm201500093.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112267/2/adhm201500093-sup-0001-S1.pd
Relevance, style and multimodality: typographical features as stylistic devices
Brightly coloured textual inserts, which often occupy a sizable
part of the TV screen, have become a key feature in Japanese TV. This
paper unpacks the contribution of such multimodal stimuli to inference, and
the consequences this has for the interpretation process. Using data derived
from a mixed-methods approach (i.e. eye-tracking and a multimodal content
analysis), we evaluate the relationship between cognitive processing and
communicative stimuli. We demonstrate how typographical features
(colours and fonts) are used as highlighting stylistic devices by TV
producers to manipulate the viewer comprehension process by guiding the
audience to an intended interpretation. The results suggest how editorial
choices regarding typographical features to trigger certain effects might be
subsumed under the current view of style in relevance theory
Low-Cost Precursors to Novel Hydrogen Storage Materials
From 2005 to 2010, The Dow Chemical Company (formerly Rohm and Haas Company) was a member of the Department of Energy Center of Excellence on Chemical Hydrogen Storage, which conducted research to identify and develop chemical hydrogen storage materials having the potential to achieve DOE performance targets established for on-board vehicular application. In collaboration with Center co-leads Los Alamos National Laboratory (LANL) and Pacific Northwest National Laboratory (PNNL), and other Center partners, Dow's efforts were directed towards defining and evaluating novel chemistries for producing chemical hydrides and processes for spent fuel regeneration. In Phase 1 of this project, emphasis was placed on sodium borohydride (NaBH{sub 4}), long considered a strong candidate for hydrogen storage because of its high hydrogen storage capacity, well characterized hydrogen release chemistry, safety, and functionality. Various chemical pathways for regenerating NaBH{sub 4} from spent sodium borate solution were investigated, with the objective of meeting the 2010/2015 DOE targets of 2-3/kg H{sub 2}) for on-board hydrogen storage systems and an overall 60% energy efficiency. With the September 2007 No-Go decision for NaBH{sub 4} as an on-board hydrogen storage medium, focus was shifted to ammonia borane (AB) for on-board hydrogen storage and delivery. However, NaBH{sub 4} is a key building block to most boron-based fuels, and the ability to produce NaBH{sub 4} in an energy-efficient, cost-effective, and environmentally sound manner is critical to the viability of AB, as well as many leading materials under consideration by the Metal Hydride Center of Excellence. Therefore, in Phase 2, research continued towards identifying and developing a single low-cost NaBH4 synthetic route for cost-efficient AB first fill, and conducting baseline cost estimates for first fill and regenerated AB using a variety of synthetic routes. This project utilized an engineering-guided R&D approach, which involved the rapid down-selection of a large number of options (chemical pathways to NaBH{sub 4}) to a smaller, more manageable number. The research began by conducting an extensive review of the technical and patent literature to identify all possible options. The down-selection was based on evaluation of the options against a set of metrics, and to a large extent occurred before experimentation was initiated. Given the vast amount of literature and patents that has evolved over the years, this approach helped to focus efforts and resources on the options with the highest technical and commercial probability of success. Additionally, a detailed engineering analysis methodology was developed for conducting the cost and energy-efficiency calculations. The methodology utilized a number of inputs and tools (Aspen PEA{trademark}, FCHTool, and H2A). The down-selection of chemical pathways to NaBH{sub 4} identified three options that were subsequently pursued experimentally. Metal reduction of borate was investigated in Dow's laboratories, research on electrochemical routes to NaBH{sub 4} was conducted at Pennsylvania State University, and Idaho National Laboratory researchers examined various carbothermal routes for producing NaBH{sub 4} from borate. The electrochemical and carbothermal studies did not yield sufficiently positive results. However, NaBH{sub 4} was produced in high yields and purities by an aluminum-based metal reduction pathway. Solid-solid reactive milling, slurry milling, and solution-phase approaches to metal reduction were investigated, and while both reactive milling and solution-phase routes point to fully recyclable processes, the scale-up of reactive milling processes to produce NaBH{sub 4} is expected to be difficult. Alternatively, a low-cost solution-phase approach to NaBH{sub 4} has been identified that is based on conventional process unit operations and should be amenable to scale-up. Numerous advances in AB synthesis have been made in recent years to improve AB yields and purities. Process analysis of several leading routes to AB (Purdue's formate-based metathesis route and PNNL's NH{sub 4}BH{sub 4}-based route) indicated the cost to produce first-fill AB to be on the order of 5/kg for a 10,000 metric tons/year sized AB plant. The analysis showed that the dominant cost component for producing first-fill AB is the cost of the NaBH4 raw material. At this AB cost and assuming 2.5 moles hydrogen released per mole of AB, it may be possible to meet DOE's 2010 storage system cost target, but the 2015 target will likely require lower cost AB and demonstrates the importance of having a low-cost route to NaBH{sub 4}. Substantial progress has also been made to define feasible pathways for the regeneration of spent ammonia borane fuel
Gross Hematuria and Lower Urinary Tract Symptoms Associated With Military Burn Pits Exposures in US Veterans Deployed to Iraq and Afghanistan
OBJECTIVE: The aim of the study is to describe rates of hematuria and other lower urinary tract symptoms, including self-reported cancer rates, among veterans postburn pits emissions exposure during deployment to Iraq and Afghanistan.
METHODS: US post-9/11 veterans with burn pits emissions exposure confirmed via DD214 forms in the Burn Pits360.org Registry were sent a modified survey. Data were deidentified and anonymously coded.
RESULTS: Twenty-nine percent of the 155 respondents exposed to burn pits self-reported seeing blood in their urine. The average index score of our modified American Urological Association Symptom Index Survey was 12.25 (SD, 7.48). High rates of urinary frequency (84%) and urgency (76%) were self-reported. Bladder, kidney, or lung cancers were self-reported in 3.87%.
CONCLUSIONS: US veterans exposed to burn pits are self-reporting hematuria and other lower urinary tract symptoms
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