2,633 research outputs found
ELECTROMYOGRAPHICAL ANALYSIS OF HAMSTRING RESISTANCE TRAINING EXERCISES
This study evaluated the EMG activity of the hamstring and quadriceps muscle groups during resistance training exercises commonly used for training the hamstrings. Subjects included 34 collegiate athletes. Hamstring and quadriceps MVIC and 6 repetition maximum loads were determined. Data were collected 72 hours later, during the performance of 6 randomly ordered exercises, including back squats, seated leg curls, stiff leg dead lifts, single leg dead lifts, good mornings, and “Russian curls.” Data were analyzed using RMS values normalized to MVIC. A one way repeated measures ANOVA revealed that significant differences existed between several exercises. Additionally, the ratio of hamstring to quadriceps co-activation was significantly different between all exercises
The northern sector of the last British ice sheet : maximum extent and demise
Strongly divided opinion has led to competing, apparently contradictory, views on the timing, extent, flow configuration and decay mechanism of the last British Ice Sheet. We review the existing literature and reconcile some of these differences using remarkable new sea-bed imagery. This bathymetric data provides unprecedented empirical evidence of confluence and subsequent separation of the last British and Fennoscandian Ice Sheets. Critically, it also allows a viable pattern of ice-sheet disintegration to be proposed for the first time. Covering the continental shelf around the northern United Kingdom, extensive echosounder data reveals striking geomorphic evidence – in the form of tunnel valleys and moraines – relating to the former British and Fennoscandian Ice Sheets. The pattern of tunnel valleys in the northern North Sea Basin and the presence of large moraines on the West Shetland Shelf, coupled with stratigraphic evidence from the Witch Ground Basin, all suggest that at its maximum extent a grounded ice sheet flowed from SE to NW across the northern North Sea Basin, terminating at the continental-shelf edge. The zone of confluence between the British and much larger Fennoscandian Ice Sheets was probably across the northern Orkney Islands, with fast-flowing ice in the Fair Isle Channel focusing sediment delivery to the Rona and Foula Wedges. This period of maximum confluent glaciation (c. 30–25 ka BP) was followed by a remarkable period of large-scale ice-sheet re-organisation. We present evidence suggesting that as sea level rose, a large marine embayment opened in the northern North Sea Basin, as far south as the Witch Ground Basin, forcing the two ice sheets to decouple rapidly along a north–south axis east of Shetland. As a result, both ice sheets rapidly adjusted to new quasi-stable margin positions forming a second distinct set of moraines (c. 24–18 ka BP). The lobate overprinted morphology of these moraines on the mid-shelf west of Orkney and Shetland indicates that the re-organisation of the British Ice Sheet was extremely dynamic — probably dominated by a series of internally forced readvances. Critically, much of the ice in the low-lying North Sea Basin may have disintegrated catastrophically as decoupling progressed in response to rising sea levels. Final-stage deglaciation was marked by near-shore ice streaming and increasing topographic control on ice-flow direction. Punctuated retreat of the British Ice Sheet continued until c. 16 ka BP when, following the North Atlantic iceberg-discharge event (Heinrich-1), ice was situated at the present-day coastline in NW Scotlan
Rote learning: the ugly duckling of student paramedic education?
The intent of this commentary is to ask questions and stimulate discussion amongst academics and paramedic educators as to whether the inherent value of rote learning has simply been lost in the shadow of more recent learning and teaching practices
Paramedic students working in snow resort medical clinics: a non-traditional interprofessional clinical placement model
This study investigates the experiences of undergraduate paramedic students completing interprofessional clinical placements in snow sport injury clinics. Qualitative methods were used to investigate the experiences of participants (n=6) undertaking non-traditional ambulance clinical placements as part of a multidisciplinary healthcare team. Ethical approval was obtained through Queensland University of Technology, Brisbane Australia. Data were collected via individual face-to-face interviews and analysed using holistic and focused coding. The analysed results indicated the presence of three main categories, namely Pre-Placement, Intra-Placement and Post-Placement phases. As it was a new placement, student capabilities were not initially known by clinic staff. Nevertheless the workplace culture was inclusive and supportive, and paramedic skills were applicable in the clinic environment. Despite the placement costs being excessive, participants viewed it as an investment in their future careers. Benefits of the placement included perceived improvement in maturity levels, the acquisition of professional networks, an understanding of interprofessional practice and an exposure to clinical skills not normally practiced during traditional ambulance placements. The interprofessional clinical placement appears to be a valid alternative to traditional ambulance placements. However, using this model to replace mainstream placements is problematic due to the costs involved, the limited number of spots available and the seasonal occurrence of snow sports
Relationships between plant traits, soil properties and carbon fluxes differ between monocultures and mixed communities in temperate grassland
1. The use of plant traits to predict ecosystem functions has been gaining growing attention. Above‐ground plant traits, such as leaf nitrogen (N) content and specific leaf area (SLA), have been shown to strongly relate to ecosystem productivity, respiration and nutrient cycling. Furthermore, increasing plant functional trait diversity has been suggested as a possible mechanism to increase ecosystem carbon (C) storage. However, it is uncertain whether below‐ground plant traits can be predicted by above‐ground traits, and if both above‐ and below‐ground traits can be used to predict soil properties and ecosystem‐level functions.
2. Here, we used two adjacent field experiments in temperate grassland to investigate if above‐ and below‐ground plant traits are related, and whether relationships between plant traits, soil properties and ecosystem C fluxes (i.e. ecosystem respiration and net ecosystem exchange) measured in potted monocultures could be detected in mixed field communities.
3. We found that certain shoot traits (e.g. shoot N and C, and leaf dry matter content) were related to root traits (e.g. root N, root C:N and root dry matter content) in monocultures, but such relationships were either weak or not detected in mixed communities. Some relationships between plant traits (i.e. shoot N, root N and/or shoot C:N) and soil properties (i.e. inorganic N availability and microbial community structure) were similar in monocultures and mixed communities, but they were more strongly linked to shoot traits in monocultures and root traits in mixed communities. Structural equation modelling showed that above‐ and below‐ground traits and soil properties improved predictions of ecosystem C fluxes in monocultures, but not in mixed communities on the basis of community‐weighted mean traits.
4. Synthesis. Our results from a single grassland habitat detected relationships in monocultures between above‐ and below‐ground plant traits, and between plant traits, soil properties and ecosystem C fluxes. However, these relationships were generally weaker or different in mixed communities. Our results demonstrate that while plant traits can be used to predict certain soil properties and ecosystem functions in monocultures, they are less effective for predicting how changes in plant species composition influence ecosystem functions in mixed communities
The Bush Medicine Project: An authentic cross-discipline, cross-course and cross-campus research project as a learning experience
The interdisciplinary nature of science is often difficult to impart upon students in teaching laboratories where chemistry students, learn chemistry and biology students, learn biology. To address this, a series of connected laboratories built around a single interdisciplinary research question were developed. The project hoped to engage students in interdisciplinary collaboration, generate meaningful chemical research data, and expose science students to indigenous Australian culture.
The pilot year of the Bush Medicine Project was run not as a standalone unit but as a cross-unit, cross-program, cross-campus and cross-discipline research project aimed at discovering medicinal compounds in native Australian plants, guided by indigenous Australian traditional medicine. Flora students collect, identify and preserve plants of interest; chemistry students prepare plant extracts and create a chemical fingerprint; microbiology and pharmacology students then screen the plant extracts for antimicrobial activity and toxicity. Students (n=55) and staff (n=7) involved in the first year of the project were surveyed or interviewed, respectively, to measure their engagement with the experiment. Participants agreed that they were more engaged than in a traditional practical class and felt they had learnt about the interdisciplinary nature of science. Student and staff attitudes have been positive and the project is planned to be continued over subsequent years
Drought soil legacy overrides maternal effects on plant growth
Maternal effects (i.e. trans-generational plasticity) and soil legacies generated by drought and plant diversity can affect plant performance and alter nutrient cycling and plant community dynamics. However, the relative importance and combined effects of these factors on plant growth dynamics remain poorly understood. We used soil and seeds from an existing plant diversity and drought manipulation field experiment in temperate grassland to test maternal, soil drought and diversity legacy effects, and their interactions, on offspring plant performance of two grassland species (Alopecurus pratensis and Holcus lanatus) under contrasting glasshouse conditions. Our results showed that drought soil legacy effects eclipsed maternal effects on plant biomass. Drought soil legacy effects were attributed to changes in both abiotic (i.e. nutrient availability) and biotic soil properties (i.e. microbial carbon and enzyme activity), as well as plant root and shoot atom 15N excess. Further, plant tissue nutrient concentrations and soil microbial C:N responses to drought legacies varied between the two plant species and soils from high and low plant diversity treatments. However, these diversity effects did not affect plant root or shoot biomass. These findings demonstrate that while maternal effects resulting from drought occur in grasslands, their impacts on plant performance are likely minor relative to drought legacy effects on soil abiotic and biotic properties. This suggests that soil drought legacy effects could become increasingly important drivers of plant community dynamics and ecosystem functioning as extreme weather events become more frequent and intense with climate change. A plain language summary is available for this article.</p
Speech and language therapy for aphasia following stroke
Background Aphasia is an acquired language impairment following brain damage that affects some or all language modalities: expression and understanding of speech, reading, and writing. Approximately one third of people who have a stroke experience aphasia. Objectives To assess the effects of speech and language therapy (SLT) for aphasia following stroke. Search methods We searched the Cochrane Stroke Group Trials Register (last searched 9 September 2015), CENTRAL (2015, Issue 5) and other Cochrane Library Databases (CDSR, DARE, HTA, to 22 September 2015), MEDLINE (1946 to September 2015), EMBASE (1980 to September 2015), CINAHL (1982 to September 2015), AMED (1985 to September 2015), LLBA (1973 to September 2015), and SpeechBITE (2008 to September 2015). We also searched major trials registers for ongoing trials including ClinicalTrials.gov (to 21 September 2015), the Stroke Trials Registry (to 21 September 2015), Current Controlled Trials (to 22 September 2015), and WHO ICTRP (to 22 September 2015). In an effort to identify further published, unpublished, and ongoing trials we also handsearched theInternational Journal of Language and Communication Disorders(1969 to 2005) and reference lists of relevant articles, and we contacted academic institutions and other researchers. There were no language restrictions. Selection criteria Randomised controlled trials (RCTs) comparing SLT (a formal intervention that aims to improve language and communication abilities, activity and participation) versus no SLT; social support or stimulation (an intervention that provides social support and communication stimulation but does not include targeted therapeutic interventions); or another SLT intervention (differing in duration, intensity, frequency, intervention methodology or theoretical approach). Data collection and analysis We independently extracted the data and assessed the quality of included trials. We sought missing data from investigators. Main results We included 57 RCTs (74 randomised comparisons) involving 3002 participants in this review (some appearing in more than one comparison). Twenty-seven randomised comparisons (1620 participants) assessed SLT versus no SLT; SLT resulted in clinically and statistically significant benefits to patients' functional communication (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.06 to 0.49, P = 0.01), reading, writing, and expressive language, but (based on smaller numbers) benefits were not evident at follow-up. Nine randomised comparisons (447 participants) assessed SLT with social support and stimulation; meta-analyses found no evidence of a difference in functional communication, but more participants withdrew from social support interventions than SLT. Thirty-eight randomised comparisons (1242 participants) assessed two approaches to SLT. Functional communication was significantly better in people with aphasia that received therapy at a high intensity, high dose, or over a long duration compared to those that received therapy at a lower intensity, lower dose, or over a shorter period of time. The benefits of a high intensity or a high dose of SLT were confounded by a significantly higher dropout rate in these intervention groups. Generally, trials randomised small numbers of participants across a range of characteristics (age, time since stroke, and severity profiles), interventions, and outcomes. Authors' conclusions Our review provides evidence of the effectiveness of SLT for people with aphasia following stroke in terms of improved functional communication, reading, writing, and expressive language compared with no therapy. There is some indication that therapy at high intensity, high dose or over a longer period may be beneficial. HIgh-intensity and high dose interventions may not be acceptable to all
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