11,855 research outputs found

    Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria

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    Microphytobenthic biofilms contain high concentrations of carbohydrate-rich extracellular polymeric substances (EPS) that are important in sediment carbon cycling. Field measurements at two locations in the Colne Estuary, U.K., showed that a significant curvilinear relationship explained 50% of the variability in chlorophyll a and EPS content. Estimates of EPS production, based on field data and published rates of production by diatoms, revealed that EPS turnover of 52% to 369% over the tidal cycle was required to account for field standing stocks. We investigated EPS degradation in sediment slurries using purified 13C-EPS produced by the diatom Nitzschia tubicola. Although EPS constituted only 5% of the sediment dissolved organic carbon (DOC) pool, 100% of the added EPS was utilized within 30 h, before decreases in other sediment-carbohydrate fractions and DOC concentrations. A general 13C enrichment of phospholipid fatty acids (PLFAs), representative of Gram-positive and Gram-negative bacteria, occurred within 6 h, with the PLFAs a15:0, i15:0, and 18:1?7c being highly enriched. The diatom PLFA 20:5?3 had relatively low but significant 13C enrichment. Stable isotope probing of 16S ribosomal ribonucleic acid (RNA-SIP) at 30 h revealed 13C-enriched sequences from the diatom genus Navicula; further evidence that diatoms assimilated the EPS, or EPS-breakdown products, from other diatom taxa. RNA-SIP also demonstrated a diverse range of highly 13C-enriched bacterial taxa, including a distinct subset (Alphaproteobacteria and Gammaproteobacteria) found only in the heavily labeled microbial assemblages. Thus, cycling of diatom EPS is rapid, and involves a wide range of microbial taxa, including some apparent specialists

    The TLR2/6 ligand PAM2CSK4 is a Th2 polarizing adjuvant in Leishmania major and Brugia malayi murine vaccine models.

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    Toll-like receptors (TLRs) play an important role in the innate and adaptive immune responses to pathogens, and are the target of new vaccine adjuvants. TLR2 plays a role in parasite recognition and activation of immune responses during cutaneous leishmaniasis infection, suggesting that TLR2 could be targeted by adjuvants for use in Leishmania vaccines. We therefore explored using Pam2CSK4 (Pam2) and Pam3CSK4 (Pam3) lipopeptide adjuvants, which activate TLR2/6 and TLR2/1 heterodimers respectively, in vaccine models for parasitic infections.The use of lipopeptide adjuvants was explored using two vaccine models. For cutaneous leishmaniasis, the lipopeptide adjuvants Pam2 and Pam3 were compared to that of the Th1-driving double-stranded DNA TLR9 agonist CpG for their ability to improve the efficacy of the autoclaved Leishmania major (ALM) vaccine to protect against L. major infection. The ability of Pam2 to enhance the efficacy of a soluble Brugia malayi microfilariae extract (BmMfE) vaccine to protect against filarial infection was also assessed in a peritoneal infection model of B. malayi filariasis. Parasite antigen-specific cellular and humoral immune responses were assessed post-challenge.The use of lipopeptides in ALM-containing vaccines did not provide any protection upon infection with L. major, and Pam2 exacerbated the disease severity in vaccinated mice post-challenge. Pam2, and to a lesser extent Pam3, were able to elevate antigen-specific immune responses post-challenge in this model, but these responses displayed a skewed Th2 phenotype as characterised by elevated levels of IgG1. In the B. malayi vaccine model, the use of Pam2 as an adjuvant with BmMfE induced significant protective immunity to the same level as inclusion of an Alum adjuvant. Here, both Pam2 and Alum were found to enhance antigen-specific antibody production post-challenge, and Pam2 significantly elevated levels of antigen-specific IL-4, IL-5 and IL-13 produced by splenocytes.These data indicate that TLR2/6-targeting ligands could be considered as adjuvants for vaccines that require robust Th2 and/or antibody-dependent immunity

    Activity-promoting gaming systems in exercise and rehabilitation

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    Commercial activity-promoting gaming systems provide a potentially attractive means to facilitate exercise and rehabilitation. The Nintendo Wii, Sony EyeToy, Dance Dance Revolution, and Xbox Kinect are examples of gaming systems that use the movement of the player to control gameplay. Activity-promoting gaming systems can be used as a tool to increase activity levels in otherwise sedentary gamers and also be an effective tool to aid rehabilitation in clinical settings. Therefore, the aim of this current work is to review the growing area of activity-promoting gaming in the context of exercise, injury, and rehabilitation

    The impact of warm-up on youth golfer clubhead speed and self-reported shot quality

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    Background/Purpose: Physical preparation in golf is now considered a key component of the game. With players becoming more athletic, warm-up has become an important area in a player's preparation for practice and competition. Much of the research to date has focused on the adult golfer, showing potential for improvements in clubhead speed, driving distance and shot quality, as well as reductions in injury risk. However, there is currently no work specifically investigating the impacts of warm-up in youth golf. The aim of this study was to examine the impact of a club only warm-up and a dynamic exercise routine followed by a club warm-up on club head speed and self-reported shot quality. Methods: Using a counterbalanced repeated measures design, eight male and 13 female youth golfers completed a control (no warm-up), club only warm-up and an exercise based dynamic warm-up followed by club warm-up on three non-consecutive days. In each session, players were required to hit 10 maximal effort shots with a driver and clubhead speed (CHS) was recorded using a launch monitor alongside self-reported shot quality scores. Results: Statistically significant improvements in clubhead speed and self-reported shot quality were seen in the dynamic warm-up combined with club warm-up. No significant differences were seen in the club-warm up only or control groups for either clubhead speed or self-reported shot quality. Conclusion: A combined dynamic physical warm-up and club warm-up improves clubhead speed and self-reported shot quality in youth golfers. However, a club warm-up alone does not seem to be sufficient in eliciting these same improvements. Level of Evidence: 3

    Biomechanics in Paralympics: Implications for Performance

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    Purpose: To provide an overview of biomechanical studies in Paralympic research and their relevance for performance in Paralympic sports. Methods: The search terms paralympic biomechanics, paralympic sport performance, paralympic athlete performance, and paralympic athlete were entered into the electronic database PubMed. Results: Thirty-four studies were found. Biomechanical studies in Paralympics mainly contributed to performance enhancement by technical optimization (n = 32) and/or injury prevention (n = 6). In addition, biomechanics was found to be important in understanding activity limitation caused by various impairments, which is relevant for evidence-based classification in Paralympic sports (n = 6). Distinctions were made between biomechanical studies in sitting (41%), standing (38%), and swimming athletes (21%). In sitting athletes, mostly kinematics and kinetics in wheelchair propulsion were studied, mainly in athletes with spinal-cord injuries. In addition, kinetics and/or kinematics in wheelchair basketball, seated discus throwing, stationary shot-putting, hand-cycling, sit-skiing, and ice sledge hockey received attention. In standing sports, primarily kinematics of athletes with amputations performing jump sports and running and the optimization of prosthetic devices were investigated. No studies were reported on other standing sports. In swimming, mainly kick rate and resistance training were studied. Conclusions: Biomechanical research is important for performance by gaining insight into technical optimization, injury prevention, and evidence-based classification in Paralympic sports. In future studies it is advised to also include physiological and biomechanical measures, allowing the assessment of the capability of the human body, as well as the resulting movement

    Active bacterioplankton community response to dissolved ‘free’ deoxyribonucleic acid (dDNA) in surface coastal marine waters

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    Seawater contains dissolved ‘free’ DNA (dDNA) that is part of a larger <0.2 μm pool of DNA (D-DNA) including viruses and uncharacterised bound DNA. Previous studies have shown that bacterioplankton readily degrade dDNA and culture-based approaches have identified several potential dDNA-utilising taxa. This study characterised the seasonal variation in D-DNA concentrations at Station L4, a coastal marine observatory in the Western English Channel, and linked changes in concentration to cognate physicochemical and biological factors. The impact of dDNA addition on active bacterioplankton communities at Station L4 was then determined using 16S rRNA high-throughput sequencing and RNA Stable Isotope Probing (RNA SIP) with 13C-labelled diatom-derived dDNA. Compared to other major bacterioplankton orders, the Rhodobacterales actively responded to dDNA additions in amended microcosms and RNA SIP identified two Rhodobacterales populations most closely associated with the genera Halocynthiibacter and Sulfitobacter that assimilated the 13C-labelled dDNA. Here we demonstrate that dDNA is a source of dissolved organic carbon for some members of the major bacterioplankton group the Marine Roseobacter Clade. This study enhances our understanding of roles of specific bacterioplankton taxa in dissolved organic matter cycling in coastal waters with potential implications for nitrogen and phosphorus regeneration processes

    Diverse groups of fungi are associated with plastics in the surface waters of the Western South Atlantic and the Antarctic Peninsula

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    Marine plastic pollution has a range of negative impacts for biota and the colonization of plastics in the marine environment by microorganisms may have significant ecological impacts. However, data on epiplastic organisms, particularly fungi, is still lacking for many ocean regions. To evaluate plastic associated fungi and their geographic distribution, we characterised plastics sampled from surface waters of the western South Atlantic (WSA) and Antarctic Peninsula (AP), using DNA metabarcoding of three molecular markers (ITS2, 18S rRNA V4 and V9 regions). Numerous taxa from eight fungal phyla and a total of 64 orders were detected, including groups that had not yet been described associated with plastics. There was a varied phylogenetic assemblage of predominantly known saprotrophic taxa within the Ascomycota and Basidiomycota. We found a range of marine cosmopolitan genera present on plastics in both locations, i.e., Aspergillus, Cladosporium, Wallemia and a number of taxa unique to each region, as well as a high variation of taxa such as Chytridiomycota and Aphelidomycota between locations. Within these basal fungal groups we identified a number of phylogenetically novel taxa. This is the first description of fungi from the Plastisphere within the Southern Hemisphere, and highlights the need to further investigate the potential impacts of plastic associated fungi on other organisms and marine ecosystems

    Community responses to seawater warming are conserved across diverse biological groupings and taxonomic resolutions

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    Temperature variability is a major driver of ecological pattern, with recent changes in average and extreme temperatures having significant impacts on populations, communities and ecosystems. In the marine realm, very few experiments have manipulated temperature in situ, and current understanding of temperature effects on community dynamics is limited. We developed new technology for precise seawater temperature control to examine warming effects on communities of bacteria, microbial eukaryotes (protists) and metazoans. Despite highly contrasting phylogenies, size spectra and diversity levels, the three community types responded similarly to seawater warming treatments of +3°C and +5°C, highlighting the critical and overarching importance of temperature in structuring communities. Temperature effects were detectable at coarse taxonomic resolutions and many taxa responded positively to warming, leading to increased abundances at the community-level. Novel field-based experimental approaches are essential to improve mechanistic understanding of how ocean warming will alter the structure and functioning of diverse marine communities

    Efficacy Of Prophylactic Knee Bracing In Conservative Management Of Knee Pain In Recreational Athletes

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    Patellofemoral pain is extremely common in recreational athletes. Patellofemoral symptoms can severely restrict participation in athletic activities, and may also progress into osteoarthritis in later life

    Professional Credentials -What Associated Schools of Construction (ASC) Members Are Doing

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    Professional Credentials have long been a part of the construction industry and many different credentials are available to the construction professional. Due to the number and variety of professional credentials it is often times difficult for individuals to decide which credentials are most advantageous to their career. ASC member schools with construction management programs have been conservative in the number and variety of professional credentials supported by their respective schools. ASC member schools have also not mirrored the construction industry in their support for certain professional credentials. This paper surveys the department heads of ASC member schools to decipher how they are incorporating professional credentials into their programs
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