1,728 research outputs found
Channel flow and the Himalayan-Tibetan orogen: a critical review
The movement of a low-viscosity crustal layer in response to topographic loading provides a potential mechanism for (1) eastward flow of the Asian lower crust causing the peripheral growth of the Tibetan Plateau and (2) southward flow of the Indian middle crust to be extruded along the Himalayan topographic front. Thermomechanical models for channel flow link such extrusion to focused orographic precipitation at the surface. Isotopic constraints on the timing of fault movement, anatexis and thermobarometric evolution of the exhumed garnet- to sillimanite-grade metasedimentary rocks support mid-crustal channel flow during the Early to Mid-Miocene. Exhumed metamorphic assemblages suggest that the dominant mechanism of the viscosity reduction that is a requirement for channel flow was melt weakening along the upper surface, defined by the South Tibetan Detachment System, and strain softening along the base, bounded by the Main Central Thrust. Neotectonic extrusion, bounded by brittle Quaternary faults south of the Main Central Thrust, is positively correlated with the spatial distribution of precipitation across a north-south transect, suggesting climate-tectonic linkage over a million-year time scale. A proposed orogen-wide eastward increase in extrusion rate over 20 Ma reflects current precipitation patterns but climate-tectonic linkage over this time scale remains equivocal
Preparación de una visión económica y estratégica para una ciudad
Comprender la economía de la ciudad se ha convertido en un componente vital de su administración. Esta situación ha surgido de dos procesos interrelacionados: a) La globalización. Es la integración, en un solo sistema económico que exhibe patrones cambiantes según la especialización local, de economías nacionales que anteriormente estaban separadas. Está impulsadapor los flujos de comercio y de capital. b) La descentralización. Esla tendencia de gobiernos nacionales a conferir poderes y asignar responsabilidades a niveles gubernamentales inferiores al nacional. Los administradores municipales se han visto, por consiguiente, en la necesidad de enterarse mejor acerca delas fortalezas y debilidades de su ciudad, de los peligros de los sectores que van debilitándose, y de las oportunidades de los sectores de alto crecimiento. Esto con el fin de brindar suapoyo a la estructura cambiante y minimizar el perjuicio social.
Synthesis and internal redox reactions of oximic and nitroso complexes
M(cup)n complexes have been prepared (M = Cu, Ni, Fe, Co, Mn, or Zn ; n=2, M-=Fe ; n=3 cupH = cupferron) and structures have been proposed on the basis of spectroscopic, thermal and magnetic techniques. Their behaviour towards the Lewis bases pyridine, triphenyl- phosphine and hydroxylamine has been investigated. All of the M(cup)2 complexes, except when M = Zn or Fe, affords adducts on reaction with pyridine, whereas the complex Fe(cup)3 underwent an internal redox reaction. Internal redox behaviour was also observed when the complexes Cu(cup)2 and Fe(cup)3 were treated with triphenylphosphine. On the basis of the nature of the products arising from these reactions and from a kinetic study of the reaction of Cu(cup) with the phosphine, mechanistic proposals have been made
An exploratory randomized controlled trial of assisted practice for improving sit-to-stand in stroke patients in the hospital setting
Objectives: To evaluate the amount of practice achieved and assess potential for effects on performance of 30 minutes of daily training in sit-to-stand. Design: Randomized controlled pilot study. Setting: Stroke rehabilitation unit, UK. Participants: Eighteen stroke patients needing 'stand by' help to sit-to-stand. Interventions: In addition to usual rehabilitation the experimental group (n=9) practised sit-to-stand and leg strengthening exercises for 30 minutes, on weekdays for two weeks, with a physiotherapy assistant. The control group received arm therapy. Main outcome measures: Frequency of sit-to-stands per day. Performance measures: rise time, weight taken through the affected foot at 'thighs off', number of attempts needed to achieve three successful sit-to-stands and the number of sit-to-stands performed in 60 seconds. Outcome was measured one and two weeks after baseline assessment. Results: Sit-to-stand frequency averaged 18 per day. Thirty minutes of practice in sit-to-stand resulted in a mean of 50 (SD 17.2) extra stands per day. There was a significant mean difference of 10% body weight taken through the affected foot after one week of intervention: The control group had reduced weight through the affected leg while the training group increased weight (F1,16 = 11.1, P=0.004, 95% confidence interval (CI) - 16.61 to - 3.72). No significant differences between groups were found on other measures. Results two weeks after baseline were inconclusive due to loss of five participants. Conclusions: Task-specific practice given for 30 minutes a day appears promising for patients learning to sit-to-stand. © SAGE Publications 2008
Using Twitter™ to drive research impact : a discussion of strategies, opportunities and challenges
Researchers have always recognised the importance of disseminating the findings of their work, however, recently the need to proactively plan and drive the impact of those findings on the wider society has become a necessity. Firstly, this is because funders require evidence of return from investment and secondly and crucially because national research assessments are becoming powerful determinants of future funding. In research studies associated with nursing, impact needs to be demonstrated by showing the effect on a range of stakeholders including service users, patients, carers, the nursing workforce and commissioners. Engaging these groups is a well-known challenge influenced by lack of access to academic journals, lack of time to read long complex research papers and lack of opportunities to interact directly with the researchers. This needs to be addressed urgently to enable nursing research to increase the impact that it has on health delivery and the work of clinical practitioners. Social media is potentially a novel way of enabling research teams to both communicate about research as studies progress and to disseminate findings and research funders are increasingly using it to publicise information about research programmes and studies they fund. A search of the healthcare literature reveals that advice and guidance on the use of social media for research studies is not well understood or exploited by the research community. This paper, therefore, explores how using social networking platforms, notably Twitter™ offers potential new ways for communicating research findings, accessing diverse and traditionally hard-to-reach audiences, knowledge exchange at an exponential rate, and enabling new means of capturing and demonstrating research impact. The paper discusses approaches to initiate the setup of social networking platforms in research projects and considers the practical challenges of using Twitter™ in nursing and healthcare research. The discussion is illuminated with examples from our current research. In summary, we suggest that the use of social media micro-blogging platforms is a contemporary, fast, easy and cost effective way to augment existing ways of disseminating research which helps drive impact
Garnet–monazite rare earth element relationships in sub-solidus metapelites: a case study from Bhutan
A key aim of modern metamorphic geochronology is to constrain precise and accurate rates and timescales of tectonic processes. One promising approach in amphibolite and granulite-facies rocks links the geochronological information recorded in zoned accessory phases such as monazite to the pressure–temperature information recorded in zoned major rock-forming minerals such as garnet. Both phases incorporate rare earth elements (REE) as they crystallize and their equilibrium partitioning behaviour potentially provides a useful way of linking time to temperature. We report REE data from sub-solidus amphibolite-facies metapelites from Bhutan, where overlapping ages, inclusion relationships and Gd/Lu ratios suggest that garnet and monazite co-crystallized. The garnet–monazite REE relationships in these samples show a steeper pattern across the heavy (H)REE than previously reported. The difference between our dataset and the previously reported data may be due to a temperature-dependence on the partition coefficients, disequilibrium in either dataset, differences in monazite chemistry or the presence or absence of a third phase that competed for the available REE during growth. We urge caution against using empirically-derived partition coefficients from natural samples as evidence for, or against, equilibrium of REE-bearing phases until monazite–garnet partitioning behaviour is better constrained
Kinetics and kinematics of strength and power development
The use of the squat exercise (and its derivatives) in gym-based settings is widespread owing to perceived functional performance enhancing effects. In particular, there has been preponderance amongst practitioners with loads that maximise power outputs (Pmax) based on a perception that mechanical peak power is directly related to explosive functional performance such as sprinting ability. The optimal muscular quality associated with squats remains elusive though, mostly due to methodological limitations in the research. The four experimental studies in this thesis sought to quantify the kinetic and kinematic outputs of a machine squat-jump and their relationship to sprinting ability, both descriptively and across a training period. First, an analysis of the kinetic and kinematic outputs of a machine squat-jump across a spectrum of loads was performed, with an emphasis on power output. Then, the relationship of these outputs with sprint ability was investigated. Correlations do not imply cause and effect, thus a training intervention was undertaken to quantify the relationships of the change in performance measures over time, and allow a comparison of different training protocols. Specifically, one training group was prescribed training loads based on individually determined peak power outputs, and the other based on traditional maximal strength training loads. Because the intention of this thesis was to enhance our knowledge of best strength training practice for elite sporting performance, highly trained athletes were specifically chosen as subjects, cognizant of the population specific nature of training adaptation. In study one, it was determined that the point on the power-load spectrum where peak and mean power occurred in the machine squat-jump was 21.6 ± 7.1 %1RM (mean ± SD) and 39.0 ± 8.6 %1RM respectively although there was considerable individual variation in these points. A broad plateau in power outputs was evident for most subjects with at most a 9.9% (90% confidence limits ±2.4%) difference in peak or means power at loads up to 20 %1RM either side of the peak. Studies two and three established that, of the multiple kinetic and kinematic measures investigated, only 1RM strength, work and impulse (all relative to body mass) provided any indication of useful kinetic / kinematic outputs that were potentially worthwhile developing for enhancing sprint performance, albeit with only moderate correlations (r = ~ -0.3). Additionally, the intercorrelations between maximal strength and explosive kinetic and kinematic measures were only moderate (r = ~0.3), casting doubt on the common practice of pursuing high 1RM strength with the intention of improving explosive muscle performance. The training study provided evidence that training at the load that maximised individual peak power output was no more effective for improving sprint ability than training at heavy loads and the changes in kinetic and kinematic outputs were not usefully related to changes in sprint ability
Measuring the health-related quality of life of children with impaired mobility:examining correlation and agreement between children and parent proxies
Abstract Objective The objective of this research project was to evaluate the validity of proxy health-related quality of life measures in the context of paediatric mobility impairment. Accurate health-related quality of life data is essential for quality-adjusted life year calculation; a key outcome in economic evaluation. Thirteen child-parent dyads (13 children with mobility impairments, 13 parent proxies) were asked to complete a range of outcome measures (EQ-5D-Y, VAS and HUI2/3) relating to the child’s health. The relationship between respondent outcomes was examined using tests of respondent type effect (Wilcoxon signed-rank), correlation (Spearman’s rank-order) and agreement (Bland–Altman plots). Results Parent proxies significantly undervalued the health-related quality of life of their mobility-impaired children: children rated their health-related quality of life higher than their parents by proxy on all measures. The VAS had the highest overall mean score for children and proxies (79.50 [SD = 15.01] and 75.77 [SD = 14.70] respectively). Child and proxy results were significantly different (p < 0.05) for all measures besides the VAS (p = 0.138). Strong correlation and acceptable agreement were observed for equivalent child/proxy VAS and HUI measures. The EQ-5D-Y exhibited the least agreement between children and proxies. Sufficient association between child/proxy VAS and HUI measures indicated a degree of interchangeability
Microfluidics in Haemostasis: a Review
Haemostatic disorders are both complex and costly in relation to both their treatment and subsequent management. As leading causes of mortality worldwide, there is an ever-increasing drive to improve the diagnosis and prevention of haemostatic disorders. The field of microfluidic and Lab on a Chip (LOC) technologies is rapidly advancing and the important role of miniaturised diagnostics is becoming more evident in the healthcare system, with particular importance in near patient testing (NPT) and point of care (POC) settings. Microfluidic technologies present innovative solutions to diagnostic and clinical challenges which have the knock-on effect of improving health care and quality of life. In this review, both advanced microfluidic devices (R&D) and commercially available devices for the diagnosis and monitoring of haemostasis-related disorders and antithrombotic therapies, respectively, are discussed. Innovative design specifications, fabrication techniques, and modes of detection in addition to the materials used in developing micro-channels are reviewed in the context of application to the field of haemostasi
Defining health-related quality of life for young wheelchair users:A qualitative health economics study
Wheelchairs for children with impaired mobility provide health, developmental and psychosocial benefits, however there is limited understanding of how mobility aids affect the health-related quality of life of children with impaired mobility. Preference-based health-related quality of life outcome measures are used to calculate quality-adjusted life years; an important concept in health economics. The aim of this research was to understand how young wheelchair users and their parents define health-related quality of life in relation to mobility impairment and wheelchair use.The sampling frame was children with impaired mobility (≤18 years) who use a wheelchair and their parents. Data were collected through semi-structured face-to-face interviews conducted in participants' homes. Qualitative framework analysis was used to analyse the interview transcripts. An a priori thematic coding framework was developed. Emerging codes were grouped into categories, and refined into analytical themes. The data were used to build an understanding of how children with impaired mobility define health-related quality of life in relation to mobility impairment, and to assess the applicability of two standard measures of health-related quality of life.Eleven children with impaired mobility and 24 parents were interviewed across 27 interviews. Participants defined mobility-related quality of life through three distinct but interrelated concepts: 1) participation and positive experiences; 2) self-worth and feeling fulfilled; 3) health and functioning. A good degree of consensus was found between child and parent responses, although there was some evidence to suggest a shift in perception of mobility-related quality of life with child age.Young wheelchair users define health-related quality of life in a distinct way as a result of their mobility impairment and adaptation use. Generic, preference-based measures of health-related quality of life lack sensitivity in this population. Development of a mobility-related quality of life outcome measure for children is recommended
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