376 research outputs found
Adolescent physical self-perceptions, sport/exercise and lifestyle physical activity
Purpose – Domain and sub-domain physical self-perceptions have been associated with adolescent moderate intensity physical activity although the association with different types of adolescent moderate intensity physical activity remains unclear. This study seeks to examine the relationship between personal self-perceptions and adolescent sport/exercise and lifestyle moderate intensity physical activity frequency.
Design/methodology/approach – A total of 122, 13-to-14 year-old, English adolescents from Leeds, West Yorkshire (58 boys and 64 girls) had their personal self-perceptions, sport/exercise and lifestyle moderate intensity physical activity assessed.
Findings – No significant positive relationships were found between boys' personal self-perceptions and lifestyle moderate intensity physical activity. However, a range of weak (r?=?0.34-0.42) but significant relationships (p?<?0.01) were found between personal self perceptions and boys' sport/exercise frequency. In contrast, only perceptions of strength competence were significantly related to girls' sport/exercise frequencies (r?=?0.28; p?<?0.05), while all personal self perceptions scales were significantly related to girls' lifestyle moderate intensity physical activity (r?=?0.26-0.32; p?<?0.05).
Research limitations/implications – The use of correlation analyses by this study placed limitations on the extent to which cause-effect relationships were established. Furthermore, girls' sport/exercise was poorly distributed, which may have led to the non-significant relationship found between this activity type and personal self-perceptions. The presence of a significant relationship between these two variables should therefore not be discounted.
Originality/value – This study seems to be the first to investigate and identify variations in the personal self-perceptions – moderate intensity physical activity relationship relative to activity type. Although more research is required, findings have implications for practitioners aiming to tailor physical activity interventions to this group and researchers aiming to match specific correlates to different types of adolescent physical activity
Improved estimates of vegetation and terrain parameters from waveform LiDAR.
Light Detection And Ranging (LiDAR) technologies have evolved rapidly over the last decade, contributing to our knowledge of the Earth's surface evolution from local to global scales. A relatively young form of LiDAR is continuous waveform, which has not yet been fully exploited. The current research investigates and develops new methods, highlighting the potential and possible pitfalls of working with continuous waveform LiDAR. The first piece of research investigates the effects of shadowing in LiDAR waveforms in physically observed, large footprint LiDAR waveforms, based on previous works noting shadowing effects in radiative transfer models, and in a controlled environment experiment. For this investigation airborne LiDAR derived digital elevation models were employed in conjunction with spatially corresponding waveform returns to identify possible shadowing effects. It was found that shadows occur more frequently over more severely sloped terrain, affecting the accuracy of waveform derived vegetation parameters. The implications of shadows in waveform data are also discussed. The second piece of research develops and tests two methods, the Slope Screening Model and Independent Slope Model, such to determine ground slope information from LiDAR waveforms. Both methods were validated against discrete return airborne LiDAR data, and British Ordnance Survey data, such to identify winch method is most suited to retrieving slope. The third piece of research utilises the favoured method for slope prediction from the second r(\searc4i topic to correct vegetation height estimates for slope. Two methods (Lox' and modified) are investigated and tested, and validated against airborne LiDAR equivalent results at the regional scale, and against normalised difference vegetation index at the near global scale. Both correction methods produced statistically significant differences in mean global vegetation heights with regards to a control dataset
Estimating Canopy Gap Fraction Using ICESat GLAS within Australian Forest Ecosystems
Spaceborne laser altimetry waveform estimates of canopy Gap Fraction (GF) vary withrespect to discrete return airborne equivalents due to their greater sensitivity to reflectance differencesbetween canopy and ground surfaces resulting from differences in footprint size, energy thresholding,noise characteristics and sampling geometry. Applying scaling factors to either the ground or canopyportions of waveforms has successfully circumvented this issue, but not at large scales. This studydevelops a method to scale spaceborne altimeter waveforms by identifying which remotely-sensedvegetation, terrain and environmental attributes are best suited to predicting scaling factors basedon an independent measure of importance. The most important attributes were identified as: soilphosphorus and nitrogen contents, vegetation height, MODIS vegetation continuous fields productand terrain slope. Unscaled and scaled estimates of GF are compared to corresponding ALS datafor all available data and an optimized subset, where the latter produced most encouraging results(R2 = 0.89, RMSE = 0.10). This methodology shows potential for successfully refining estimates ofGF at large scales and identifies the most suitable attributes for deriving appropriate scaling factors.Large-scale active sensor estimates of GF can establish a baseline from which future monitoringinvestigations can be initiated via upcoming Earth Observation missions
How Has COVID-19 Affected Our Orthopedic Implant Industry Partners? Implications for the Surgeon-Industry Relationship in 2020 and Beyond
This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background
The COVID-19 pandemic has had far-reaching societal and financial consequences. The purpose of this study was to evaluate how COVID-19 has affected AAHKS industry partners and the surgeon-industry relationship, emphasizing education, resource allocation, and strategic direction for the 2nd half of 2020.
Methods
AAHKS industry partners were contacted to participate in a blinded survey and optional interview with the AAHKS Industry Relations Committee. Based on the results, a group of AAHKS member surgeons with disparate practice types were asked to postulate on how the COVID-19 pandemic has and will affect their practice and relationship with Industry.
Results
AAHKS industry partner responses indicated decreased resource allocation for regional, “other national,” and AAHKS annual meetings (67%, 55%, and 30%, respectively). Web-based educational content was expected to increase in 2020 and will likely remain a point of emphasis in 2021 (100% and 70% of responders). For Q3/Q4 2020, a significant emphasis was placed on site of service/outpatient TJA and COVID-19-related safety measures (70% and 90% of responders), as well as increased availability of instrumentation and implants (40% and 60%, respectively).
Conclusion
The COVID-19 pandemic has altered the orthopedic landscape for the foreseeable future. Survey responses by AAHKS industry partners demonstrate a continued commitment to surgeon education with and increasing shift to a web-based platform. Increased resource allocation for outpatient TJA and COVID-19-related safety measures were significant. Articulating optimal mechanisms to aid industry in supporting surgeons with different practice models to meet demand during the second half of fiscal year 2020 will be critical
Interventions for treating anxiety after stroke
Background:
Approximately 20% of stroke patients experience anxiety at some point after stroke.
Objectives:
To determine if any treatment for anxiety after stroke decreases the proportion of patients with anxiety disorders or symptoms, and to determine the effect of treatment on quality of life, disability, depression, social participation, risk of death or caregiver burden.
Search methods:
We searched the trials register of the Cochrane Stroke Group (October 2010), CENTRAL (The Cochrane Library 2010, Issue 4), MEDLINE (1950 to October 2010), EMBASE (1947 to October 2010), PsycINFO (1806 to October 2010), Allied and Complementary Medicine database (AMED) (1985 to October 2010), Cumulative Index to Nursing and Allied Health (CINAHL) (1982 to October 2010), Proquest Digital Dissertations (1861 to October 2010), and Psychological Database for Brain Impairment Treatment Efficacy (PsycBITE) (2004 to October 2010). In an effort to identify further published, unpublished and ongoing trials, we searched trial registries and major international stroke conference proceedings, scanned reference lists, and contacted select individuals known to the review team who are actively involved in psychological aspects of stroke research, and the Association of the British Pharmaceutical Industry.
Selection criteria:
Two review authors independently screened and selected titles and abstracts for inclusion in the review. Randomised trials of any intervention in patients with stroke where the treatment of anxiety was an outcome were eligible.
Data collection and analysis:
Two review authors independently extracted data for analysis. We performed a narrative review. A meta-analysis was planned but not carried out as studies were not of sufficient quality to warrant doing so.
Main results:
We included two trials (three interventions) involving 175 participants with co-morbid anxiety and depression in the review. Both trials used the Hamilton Anxiety Scale (HAM-A) to assess anxiety, and neither included a placebo control group. One trial randomised 81 patients to paroxetine, paroxetine plus psychotherapy or standard care. Mean level of anxiety severity scores were 58% and 71% lower in the paroxetine, and paroxetine plus psychotherapy groups respectively compared with those in standard care at follow-up (P < 0.01). The second trial randomised 94 stroke patients, also with co-morbid anxiety and depression, to receive buspirone hydrochloride or standard care. At follow-up, the mean level of anxiety was significantly lower for those receiving buspirone relative to controls (P < 0.01). Half of the participants receiving paroxetine experienced adverse events that included nausea, vomiting or dizziness; however, only 14% of those receiving buspirone experienced nausea or palpitations. No information was provided about the duration of symptoms associated with adverse events.
Authors' conclusions:
There is insufficient evidence to guide the treatment of anxiety after stroke. The data available suggest that pharmaceutical therapy (paroxetine and buspirone) may be effective in reducing anxiety symptoms in stroke patients with co-morbid anxiety and depression. No information was available for stroke patients with anxiety only. Randomised placebo controlled trials are needed
Brief for Respondents, Grutter v. Bollinger, 539 US 306 (2003) (No. 02-241).
QUESTIONS PRESENTED
1. Whether this Court should reaffirm its decision in Regents of University of California v. Bakke, 438 U.S. 265 (1978) and hold that the educational benefits that flow from a diverse student body to an institution of higher education, its students, and the public it serves, are sufficiently compelling to permit the school to consider race and/or ethnicity as one of many factors in making admissions decisions through a properly devised admissions program.
2. Whether the Court of Appeals correctly held that the University of Michigan Law School\u27s admissions program is properly devised
Estimating forest canopy parameters from satellite waveform LiDAR by inversion of the FLIGHT three-dimensional radiative transfer model
The Geoscience Laser Altimeter System (GLAS) has the potential to accurately map global vegetation heights and fractional cover metrics using active laser pulse emission/reception. However, large uncertainties in the derivation of data products exist, since multiple physically plausible interpretations of the data are possible. In this study a method is described and evaluated to derive vegetation height and fractional cover from GLAS waveforms by inversion of the FLIGHT radiative transfer model. A lookup-table is constructed giving expected waveforms for a comprehensive set of canopy realisations, and is used to determine the most likely set of biophysical parameters describing the forest structure, consistent with any given GLAS waveform. The parameters retrieved are canopy height, leaf area index (LAI), fractional cover and ground slope. The range of possible parameters consistent with the waveform is used to give a per-retrieval uncertainty estimate for each retrieved parameter. The retrieved estimates were evaluated first using a simulated data set and then validated against airborne laser scanning (ALS) products for three forest sites coincident with GLAS overpasses. Results for height retrieval show mean absolute error (MAE) of 3.71 m for a mixed temperate forest site within Forest of Dean (UK), 3.35 m for the Southern Old Aspen Site, Saskatchewan, Canada, and 5.13 m for a boreal coniferous site in Norunda, Sweden. Fractional cover showed MAE of 0.10 for Forest of Dean and 0.23 for Norunda. Coefficient of determination between ALS and GLAS estimates over the combined dataset gave R2 values of 0.71 for height and 0.48 for fractional cover, with biases of −3.4 m and 0.02 respectively. Smallest errors were found where overpass dates for ALS data collection closely matched GLAS overpasses. Explicit instrument parameterisation means the method is readily adapted to future planned spaceborne LiDAR instruments such as GEDI
Mapping Arctic Bottomfast Sea Ice Using SAR Interferometry
Bottomfast sea ice is an integral part of many near-coastal Arctic ecosystems with implications for subsea permafrost, coastal stability and morphology. Bottomfast sea ice is also of great relevance to over-ice travel by coastal communities, industrial ice roads, and marine habitats. There are currently large uncertainties around where and how much bottomfast ice is present in the Arctic due to the lack of effective approaches for detecting bottomfast sea ice on large spatial scales. Here, we suggest a robust method capable of detecting bottomfast sea ice using spaceborne synthetic aperture radar interferometry. This approach is used to discriminate between slowly deforming floating ice and completely stationary bottomfast ice based on the interferometric phase. We validate the approach over freshwater ice in the Mackenzie Delta, Canada, and over sea ice in the Colville Delta and Elson Lagoon, Alaska. For these areas, bottomfast ice, as interpreted from the interferometric phase, shows high correlation with local bathymetry and in-situ ice auger and ground penetrating radar measurements. The technique is further used to track the seasonal evolution of bottomfast ice in the Kasegaluk Lagoon, Alaska, by identifying freeze-up progression and areas of liquid water throughout winter
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