892 resultados para 894
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Background and purpose There are no published studies on the parameterisation and reliability of the single-leg stance (SLS) test with inertial sensors in stroke patients. Purpose: to analyse the reliability (intra-observer/inter-observer) and sensitivity of inertial sensors used for the SLS test in stroke patients. Secondary objective: to compare the records of the two inertial sensors (trunk and lumbar) to detect any significant differences in the kinematic data obtained in the SLS test. Methods Design: cross-sectional study. While performing the SLS test, two inertial sensors were placed at lumbar (L5-S1) and trunk regions (T7–T8). Setting: Laboratory of Biomechanics (Health Science Faculty - University of Málaga). Participants: Four chronic stroke survivors (over 65 yrs old). Measurement: displacement and velocity, Rotation (X-axis), Flexion/Extension (Y-axis), Inclination (Z-axis); Resultant displacement and velocity (V): RV=(Vx2+Vy2+Vz2)−−−−−−−−−−−−−−−−−√ Along with SLS kinematic variables, descriptive analyses, differences between sensors locations and intra-observer and inter-observer reliability were also calculated. Results Differences between the sensors were significant only for left inclination velocity (p = 0.036) and extension displacement in the non-affected leg with eyes open (p = 0.038). Intra-observer reliability of the trunk sensor ranged from 0.889-0.921 for the displacement and 0.849-0.892 for velocity. Intra-observer reliability of the lumbar sensor was between 0.896-0.949 for the displacement and 0.873-0.894 for velocity. Inter-observer reliability of the trunk sensor was between 0.878-0.917 for the displacement and 0.847-0.884 for velocity. Inter-observer reliability of the lumbar sensor ranged from 0.870-0.940 for the displacement and 0.863-0.884 for velocity. Conclusion There were no significant differences between the kinematic records made by an inertial sensor during the development of the SLS testing between two inertial sensors placed in the lumbar and thoracic regions. In addition, inertial sensors. Have the potential to be reliable, valid and sensitive instruments for kinematic measurements during SLS testing but further research is needed.
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Stress analysis within carotid plaques based on in vivo MR imaging has shown to be useful for the identification of vulnerable atheroma. This study is to investigate whether magnetic resonance imaging (MRI) based-biomechanical stress analysis of carotid plaques can differentiate acute symptomatic and asymptomatic patients. 54 asymptomatic and 45 acute symptomatic patients underwent in vivo multi-contrast MRI of the carotid arteries. Plaque geometry used for finite element analysis was derived from in vivo MR images at the site of maximum and minimum plaque burden. In total 198 slices were used for the computational simulations. A pre shrink technique was used to refine the simulation. Maximum principle stress at the vulnerable plaque sites (i.e. critical stress) was extracted for the selected slices and a comparison was performed between the two groups. Critical stress at the site of maximum plaque burden is significantly higher in acute symptomatic patients as compared to asymptomatic patients [median: 198.0kPa (inter quartile range (IQR) = (119.8 - 359.0) vs. 138.4kPa (83.8, 242.6), p=0.04]. No significant difference was found at the minimum plaque burden site between the two groups [196.7kPa (133.3- 282.7) vs. 182.4kPa (117.2 - 310. 6), p=0.82). Stress analysis at the site of maximal plaque burden can be effectively used for differentiating acute symptomatic carotid plaques from asymptomatic plaques. This maybe potentially used for development of biomechanical risk stratification criteria based on plaque burden in future studies.
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The reliability of ants as bioindicators of ecosystem condition is dependent on the consistency of their response to localised habitat characteristics, which may be modified by larger-scale effects of habitat fragmentation and loss. We assessed the relative contribution of habitat fragmentation, habitat loss and within-patch habitat characteristics in determining ant assemblages in semi-arid woodland in Queensland, Australia. Species and functional group abundance were recorded using pitfall traps across 20 woodland patches in landscapes that exhibited a range of fragmentation states. Of fragmentation measures, changes in patch area and patch edge contrast exerted the greatest influence on species assemblages, after accounting for differences in habitat loss. However, 35% of fragmentation effects on species were confounded by the effects of habitat characteristics and habitat loss. Within-patch habitat characteristics explained more than twice the amount of species variation attributable to fragmentation and four times the variation explained by habitat loss. The study indicates that within-patch habitat characteristics are the predominant drivers of ant composition. We suggest that caution should be exercised in interpreting the independent effects of habitat fragmentation and loss on ant assemblages without jointly considering localised habitat attributes and associated joint effects.
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Abstract is not available.
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Psychotic-like experiences (PLEs) have been associated with increased risk of suicidality, but it is unclear whether the level of risk varies with different types of PLE. A cross-sectional online survey was completed by 1610 university students. Respondents completed the Community Assessment of Psychic Experiences-15 (CAPE-P15) assessing PLEs on three subscales: Perceptual Abnormalities (PA), Persecutory Ideation (PI) and Bizarre Experiences (BE). Lifetime suicidal ideation, plans and attempts, cannabis, ecstasy and methamphetamine use and family history of mental disorder were also assessed. Multinomal logistic regression was used to examine unique determinants of lifetime suicidality, defined as any history of (i) suicidal ideation or plans and (ii) any attempt, relative to no lifetime history of suicidality. A lifetime history of PA and PI provided significant unique contributions to the prediction of suicide risk, after control for other significant predictors. BE were not associated with any suicide variable demonstrating the variation in risk of suicidality with different types of PLEs. Perceptual abnormalities and persecutory ideation as measured by the CAPE-P15 are the PLEs associated with a higher risk of lifetime suicidality.
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The present review identifies various constraints relating to poor adoption of ley-pastures in south-west Queensland, and suggests changes in research, development and extension efforts for improved adoption. The constraints include biophysical, economic and social constraints. In terms of biophysical constraints, first, shallower soil profiles with subsoil constraints (salt and sodicity), unpredictable rainfall, drier conditions with higher soil temperature and evaporative demand in summer, and frost and subzero temperature in winter, frequently result in a failure of established, or establishing, pastures. Second, there are limited options for legumes in a ley-pasture, with the legumes currently being mostly winter-active legumes such as lucerne and medics. Winter-active legumes are ineffective in improving soil conditions in a region with summer-dominant rainfall. Third, most grain growers are reluctant to include grasses in their ley-pasture mix, which can be uneconomical for various reasons, including nitrogen immobilisation, carryover of cereal diseases and depressed yields of the following cereal crops. Fourth, a severe depletion of soil water following perennial ley-pastures (grass + legumes or lucerne) can reduce the yields of subsequent crops for several seasons, and the practice of longer fallows to increase soil water storage may be uneconomical and damaging to the environment. Economic assessments of integrating medium- to long-term ley-pastures into cropping regions are generally less attractive because of reduced capital flow, increased capital investment, economic loss associated with establishment and termination phases of ley-pastures, and lost opportunities for cropping in a favourable season. Income from livestock on ley-pastures and soil productivity gains to subsequent crops in rotation may not be comparable to cropping when grain prices are high. However, the economic benefits of ley-pastures may be underestimated, because of unaccounted environmental benefits such as enhanced water use, and reduced soil erosion from summer-dominant rainfall, and therefore, this requires further investigation. In terms of social constraints, the risk of poor and unreliable establishment and persistence, uncertainties in economic and environmental benefits, the complicated process of changing from crop to ley-pastures and vice versa, and the additional labour and management requirements of livestock, present growers socially unattractive and complex decision-making processes for considering adoption of an existing medium- to long-term ley-pasture technology. It is essential that research, development and extension efforts should consider that new ley-pasture options, such as incorporation of a short-term summer forage legume, need to be less risky in establishment, productive in a region with prevailing biophysical constraints, economically viable, less complex and highly flexible in the change-over processes, and socially attractive to growers for adoption in south-west Queensland.
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Near infrared (NIR) spectroscopy was investigated as a potential rapid method of estimating fish age from whole otoliths of Saddletail snapper (Lutjanus malabaricus). Whole otoliths from 209 Saddletail snapper were extracted and the NIR spectral characteristics were acquired over a spectral range of 800–2780 nm. Partial least-squares models (PLS) were developed from the diffuse reflectance spectra and reference-validated age estimates (based on traditional sectioned otolith increments) to predict age for independent otolith samples. Predictive models developed for a specific season and geographical location performed poorly against a different season and geographical location. However, overall PLS regression statistics for predicting a combined population incorporating both geographic location and season variables were: coefficient of determination (R2) = 0.94, root mean square error of prediction (RMSEP) = 1.54 for age estimation, indicating that Saddletail age could be predicted within 1.5 increment counts. This level of accuracy suggests the method warrants further development for Saddletail snapper and may have potential for other fish species. A rapid method of fish age estimation could have the potential to reduce greatly both costs of time and materials in the assessment and management of commercial fisheries.
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The complex crystallizes in the space group P21/c with four formula units in a unit cell of dimensions a= 12.747, b= 7.416, c= 17.894 A and/3= 90.2 °. The structure has been solved by the symbolic addition procedure using three-dimensional photographic data and refined to an R value of 0.079 for 2019 observed reflexions. The pyramidal nature of the two hetero nitrogen atoms in the antipyrine molecule is inter:nediate between that observed in free antipyrine and in some of its metal complexes. The molecule is more polar than that in crystals of free antipyrine but less so compared with that in metal complexes. In the salicylic acid molecule, the hydroxyl group forms an internal hydrogen bond with one of the oxygen atoms in the carboxyl group. The association between the salicylic acid and the antipyrine molecules is achieved through an intermolecular hydrogen bond with the other carboxyl oxygen atom in the salicylic acid molecule as the proton donor and the carboxyl oxygen atom of the antipyrine molecule as the acceptor.
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The special class of quasi-simple wave solutions is studied for the system of partial differential equations governing inviscid acoustic gravity waves. It is shown that these traveling wave solutions do not admit shocks. Periodic solutions are found to exist when there is no propagation in the vertical direction. The solutions for some particular cases are depicted graphically. Physics of Fluids is copyrighted by The American Institute of Physics.
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BACKGROUND Negative donation experiences, including vasovagal reactions, deter donor retention. However, whether this deterrence effect varies as a function of whole blood (WB) donation history and requests to donate the same or a different product remains unclear. STUDY DESIGN AND METHODS The responses of 894 eligible WB donors who had been approached to convert to plasmapheresis and 954 eligible first-time plasmapheresis donors who had been surveyed on their last donation experience and their intention to donate plasma were considered. This information was matched with individual vasovagal reaction records, deferral category, WB donation history, and subsequent donation behavioral data obtained from the blood collection agency. RESULTS Path analysis indicated that the application of a deferral and an officially recorded vasovagal reaction decreased donors' intentions to continue plasmapheresis donation, but had no effect on WB donors' intentions to convert to plasmapheresis. Consistent with past findings, vasovagal reactions occurred more frequently with female and inexperienced donors. CONCLUSION Experiencing vasovagal reactions and deferrals may not universally deter donors from continuing to donate. Rather, the offer to convert to another form of donation—in this instance, plasmapheresis—after experiencing a negative donation event while donating WB may be sufficient to eliminate the deterrence effect on retention.
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The determination of the overconsolidation ratio (OCR) of clay deposits is an important task in geotechnical engineering practice. This paper examines the potential of a support vector machine (SVM) for predicting the OCR of clays from piezocone penetration test data. SVM is a statistical learning theory based on a structural risk minimization principle that minimizes both error and weight terms. The five input variables used for the SVM model for prediction of OCR are the corrected cone resistance (qt), vertical total stress (sigmav), hydrostatic pore pressure (u0), pore pressure at the cone tip (u1), and the pore pressure just above the cone base (u2). Sensitivity analysis has been performed to investigate the relative importance of each of the input parameters. From the sensitivity analysis, it is clear that qt=primary in situ data influenced by OCR followed by sigmav, u0, u2, and u1. Comparison between SVM and some of the traditional interpretation methods is also presented. The results of this study have shown that the SVM approach has the potential to be a practical tool for determination of OCR.
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There is increasing evidence that the origins of poor adult health and health inequalities can be traced back to circumstances preceding current socioeconomic position and living conditions. The life-course approach to examining the determinants of health has emphasised that exposure to adverse social and economic circumstances in earlier life or concurrent adverse circumstances due to unfavourable living conditions in earlier life may lead to poor health, health-damaging behaviour, disease or even premature death in adulthood. There is, however, still a lack of knowledge about the contribution of social and economic circumstances in childhood and youth to adult health and health inequalities, and even less is known about how environmental and behavioural factors in adulthood mediate the effects of earlier adverse experiences. The main purpose of this study was to deepen our understanding of the development of poor health, health-damaging behaviours and health inequalities during the life-course. Its aim was to find out which factors in earlier and current circumstances determine health, the most detrimental indicators of health behaviour (smoking, heavy drinking and obesity as a proxy for the balance between nutrition and exercise), and educational health differences in young adults in Finland. Following the ideas of the social pathway theory, it was assumed that childhood environment affects adult health and its proximal determinants via different pathways, including educational, work and family careers. Early adulthood was studied as a significant phase of life when many behavioural patterns and living conditions relevant to health are established. In addition, socioeconomic health inequalities seem to emerge rapidly when moving into adulthood; they are very small or non-existent in childhood and adolescence, but very marked by early middle age. The data of this study were collected in 2000 2001 as part of the Health 2000 Survey (N = 9,922), a cross-sectional and nationally representative health interview and examination survey. The main subset of data used in this thesis was the one comprising the age group 18 29 years (N = 1,894), which included information collected by standardised structured computer-aided interviews and self-administered questionnaires. The survey had a very high participation rate at almost 90% for the core questions. According to the results of this study, childhood circumstances predict the health of young adults. Almost all the childhood adversities studied were found to be associated with poor self-rated health and psychological distress in early adulthood, although fewer associations were found with the somatic morbidity typical of young adults. These effects seemed to be more or less independent of the young adult s own education. Childhood circumstances also had a strong effect on smoking and heavy drinking, although current circumstances and education in particular, played a role in mediating this effect. Parental smoking and alcohol abuse had an influence on the corresponding behaviours of offspring. Childhood circumstances had a role in the development of obesity and, to a lesser extent, overweight, particularly in women. The findings support the notion that parental education has a strong effect on early adult obesity, even independently of the young adult s own educational level. There were marked educational differences in self-rated health in early adulthood: those in the lowest educational category were most likely to have average or poorer health. Childhood social circumstances seemed to explain a substantial part of these educational differences. In addition, daily smoking and heavy drinking contributed substantially to educational health differences. However, the contribution of childhood circumstances was largely shared with health behaviours adopted by early adulthood. Employment also shared the effects of childhood circumstances on educational health differences. The results indicate that childhood circumstances are important in determining health, health behaviour and health inequalities in early adulthood. Early recognition of childhood adversities followed by relevant support measures may play an important role in preventing the unfortunate pathways leading to the development of poor health, health-damaging behaviour and health inequalities. It is crucially important to recognise the needs of children living in adverse circumstances as well as children of substance abusing parents. In addition, single-parent families would benefit from support. Differences in health and health behaviours between different sub-groups of the population mean that we can expect to see ever greater health differences when today s generation of young adults grows older. This presents a formidable challenge to national health and social policy as well as health promotion. Young adults with no more than primary level education are at greatest risk of poor health. Preventive policies should emphasise the role of low educational level as a key determinant of health-damaging behaviours and poor health. Keywords: health, health behaviour, health inequalities, life-course, socioeconomic position, education, childhood circumstances, self-rated health, psychological distress, somatic morbidity, smoking, heavy drinking, BMI, early adulthood
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The complex crystallizes in the space group P21/c with four formula units in a unit cell of dimensionsa= 12.747, b= 7.416, c= 17.894 A and/3= 90.2 °. The structure has been solved by the symbolic addition procedure using three dimensional photographic data and refined to an R value of 0.079 for 2019 observed reflexions. The pyramidal nature of the two hetero nitrogen atoms in the antipyrine molecule is inter:nediate between that observed in free antipyrine and in some of its metal complexes. The molecule is more polar than that in crystals of free antipyrine but less so compared with that in metal complexes. In the salicylic acid molecule, the hydroxyl group forms an internal hydrogen bond with one of the oxygen atoms in the carboxyl group. The association between the salicylic acid and the antipyrine molecules is achieved through an intermolecular hydrogen bond with the other carboxyl oxygen atom in the salicylic acid molecule as the proton donor and the carboxyl oxygen atom of the antipyrine molecule as the acceptor
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Nanocrystalline perovskite barium titanate with an average particle size less than similar to 10 nm is produced using sol-gel route involving ligand-assisted templating. BaTiO3 is obtained by the controlled hydrolysis and condensation reaction of barium acetate (Ba(CH3COO)(2)) with titanium tetra chloride (TiCl4) in the reverse micelles of dodecylamine (DDA) which is used as the template. Our attempts to produce mesoporous BaTiO3 have resulted in the formation of nanocrystalline BaTiO3. The synthesis of nanostructured BaTiO3 is carried out using the ligand-assisted templating approach which proceeds through the sol-gel route. Dodecylamine is used as the template. The sol-gel process in general presents inherent advantages because the nanostructure of the desired materials can be controlled together with their porous structure. Ligand-assisted templating approach involves the formation of covalent bond between the inorganic analogue and the template. Ba(CH3COO)(2) and TiCl4 are used as barium-source and titanium-source respectively. The reaction between Ba(CH3COO)(2) and TiCl4 is found to take place deliberately on the pre-assembled species which acts as the template or occurring with in them which in turn will lead to the generation of the desired nanoscale structure (nanopores or nanoparticles).