4,190 research outputs found
Seeding of the nematic-isotropic phase transition by an electric field
In this paper, we use a relatively simple continuum model to investigate the effects of dielectric inhomogeneity within confined liquid crystal cells. Specifically, we consider, in planar, cylindrical and spherical geometries, the stability of a nematic-isotropic interface subject to an applied voltage. Depending on the magnitude of this voltage, the temperature and the geometry of the cell, the nematic region may shrink until the material is completely isotropic within the cell, grow until the nematic phase cells the cell or, in certain geometries, coexist with the isotropic phase. For planar geometry, no coexistence is found, but we are able to give analytical expressions for the critical voltage for an electric-field-induced phase transition as well as the critical wetting layer thickness for arbitrary applied voltage. In cells with cylindrical and spherical geometries, however, stable nematic-isotropic coexistence is predicted, the thickness of the nematic region being controllable by alteration of the applied voltage.</p
Flow distributed oscillation, flow velocity modulation and resonance
We examine the effects of a periodically varying flow velocity on the
standing and travelling wave patterns formed by the flow-distributed
oscillation (FDO) mechanism. In the kinematic (or diffusionless) limit, the
phase fronts undergo a simple, spatiotemporally periodic longitudinal
displacement. On the other hand, when the diffusion is significant, periodic
modulation of the velocity can disrupt the wave pattern, giving rise in the
downstream region to travelling waves whose frequency is a rational multiple of
the velocity perturbation frequency. We observe frequency locking at ratios of
1:1, 2:1 and 3:1, depending on the amplitude and frequency of the velocity
modulation. This phenomenon can be viewed as a novel, rather subtle type of
resonant forcing.Comment: submitted to Phys. Rev.
Evaluation of a multidisciplinary Tier 3 weight management service for adults with morbid obesity, or obesity and comorbidities, based in primary care
A multidisciplinary Tier 3 weight management service in primary care recruited patients with a body mass index â„40âkg·mâ2, or 30âkg·mâ2 with obesity-related co-morbidity to a 1-year programme. A cohort of 230 participants was recruited and evaluated using the National Obesity Observatory Standard Evaluation Framework. The primary outcome was weight loss of at least 5% of baseline weight at 12 months. Diet was assessed using the two-item food frequency questionnaire, activity using the General Practice Physical Activity questionnaire and quality of life using the EuroQol-5D-5L questionnaire. A focus group explored the participants' experiences. Baseline mean weight was 124.4âkg and mean body mass index was 44.1âkg·mâ2. A total of 102 participants achieved 5% weight loss at 12 months. The mean weight loss was 10.2âkg among the 117 participants who completed the 12-month programme. Baseline observation carried forward analysis gave a mean weight loss of 5.9âkg at 12 months. Fruit and vegetable intake, activity level and quality of life all improved. The dropout rate was 14.3% at 6 months and 45.1% at 1 year. Focus group participants described high levels of satisfaction. It was possible to deliver a Tier 3 weight management service for obese patients with complex co-morbidity in a primary care setting with a full multidisciplinary team, which obtained good health outcomes compared with existing services
Is early center-based child care associated with tantrums and unmanageable behavior over time up to school entry?
Background. Existing research suggests that there is a relationship between greater exposure to center-based child care and child behavioral problems though the mechanism for the impact is unclear. However the measure used to document child care has usually been average hours, which may be particularly unreliable in the early months when fewer children are in center care. In addition individual trajectories for behavior difficulties have not been studied.
Objective. The purpose of the current study was to examine whether the extent of exposure to center-based child care before two years predicted the trajectory of childrenâs difficult behavior (i.e., tantrums and unmanageable behavior) from 30 to 51 months controlling for child and maternal characteristics.
Method. Data were drawn from UK-based Families, Children and Child Care (FCCC) study (n=1201). Individual growth models were fitted to test the relation between early center-based child care experiences and subsequent difficult behavior.
Results. Children with more exposure to center-based care before two had less difficult behavior at 30 months, but more increase over time. Initial levels were predicted by higher difficult temperament and lower verbal ability. Higher difficult temperament and lower family socio-economic status predicted its change over time.
Conclusion. Findings suggest that early exposure to center-based care before two years old is a risk factor for subsequent behavior problems especially when children have a longer period of exposure. A possible explanatory process is that child coping strategies to manage frustration are less well developed in a group context, especially when they lag behind in expressive language
Socioeconomic risk, parenting during the preschool years and child health age 6 years
Parentâchild relationships and parenting processes are emerging as potential life course
determinants of health. Parenting is socially patterned and could be one of the factors responsible for
the negative effects of social inequalities on health, both in childhood and adulthood. This study tests
the hypothesis that some of the effect of socioeconomic risk on health in mid childhood is transmitted
via early parenting. Methods: Prospective cohort study in 10 USA communities involving 1041 mother/
child pairs, selected at birth at random with conditional sampling. Exposures: income, maternal
education, maternal age, lone parenthood, ethnic status and objective assessments of mother child
interaction in the first 4 years of life covering warmth, negativity and positive control. Outcomes:
motherâs report of childâs health in general at 6 years. Modelling: multiple regression analyses with
statistical testing of mediational processes. Results: All five indicators of socioeconomic status (SES) were
correlated with all three measures of parenting, such that low SES was associated with poor parenting.
Among the measures of parenting maternal warmth was independently predictive of future health, and
among the socioeconomic variables maternal education, partner presence and âother ethnic groupâ
proved predictive. Measures of parenting significantly mediated the impact of measures of SES on child
health. Conclusions: Parenting mediates some, but not all of the detectable effects of socioeconomic
risk on health in childhood. As part of a package of measures that address other determinants,
interventions to support parenting are likely to make a useful contribution to reducing childhood
inequalities in health
Medicines adherence: Involving patients in decisions about prescribed medicines and supporting adherence
It is thought that between a third and a half of all medicines1
There are many causes of non-adherence but they fall into two overlapping categories: intentional and unintentional. Unintentional non-adherence occurs when the patient wants to follow the agreed treatment but is prevented from doing so by barriers that are beyond their control. Examples include poor recall or difficulties in understanding the instructions, problems with using the treatment, inability to pay for the treatment, or simply forgetting to take it. prescribed for long-term conditions are not taken as recommended. If the prescription is appropriate, then this may represent a loss to patients, the healthcare system and society. The costs are both personal and economic. Adherence presumes an agreement between prescriber and patient about the prescriberâs recommendations. Adherence to medicines is defined as the extent to which the patientâs action matches the agreed recommendations. Non-adherence may limit the benefits of medicines, resulting in lack of improvement, or deterioration, in health. The economic costs are not limited to wasted medicines but also include the knock-on costs arising from increased demands for healthcare if health deteriorates. Non-adherence should not be seen as the patientâs problem. It represents a fundamental limitation in the delivery of healthcare, often because of a failure to fully agree the prescription in the first place or to identify and provide the support that patients need later on. Addressing non-adherence is not about getting patients to take more medicines per se. Rather, it starts with an exploration of patientsâ perspectives of medicines and the reasons why they may not want or are unable to use them. Healthcare professionals have a duty to help patients make informed decisions about treatment and use appropriately prescribed medicines to best effec
Nonâpharmacological interventions for challenging behaviours of adults with intellectual disabilities: A metaâanalysis
Background Non-pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta-analysis is to update the existing evidence, to investigate long-term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness. Method An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi-experimental designs were included. We performed an overall random-effect meta-analysis and subgroup analyses. Results We found a significant moderate overall effect of non-pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352-0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs. Conclusions Non-pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities
Understanding Shoot and Root Development
Shoot and root development of the grass tiller is presented as a series of events on the tiller axis. Leaf, tiller bud, true stem, and root development are successive events in the life cycle of a single phytomer and the tiller is a co-ordinated series of phytomers, successive phytomers being progressively more advanced than the previous phytomer. In reviewing the individual growth processes of leaf, tiller, true stem, and root formation, fundamental determinants of light and nutrient capture are examined and examples presented to illustrate the link between component processes, plant morphogenesis, and plant performance. An example of the application of this understanding in plant improvement is given
National Certification Programme for Cardiovascular Rehabilitation â aiming to improve practice
Cardiovascular disease (CVD) continues to be a leading cause of mortality and morbidity in the United Kingdom.1 It is also a leading contributor to health inequalities; reducing excess deaths from coronary heart disease in the most deprived fifth of areas would have the greatest impact on the life expectancy gap in England.2 Cardiovascular rehabilitation (CR) is a multifaceted secondary prevention programme which aims to improve outcomes for people with CVD, with strong evidence of clinical and cost-effectiveness,3 and is recommended by the National Institute for Health and Care Excellence (NICE).4,5 The evidence-based service standards for delivery6,7 include centre or home-based options (equally effective8), by a multidisciplinary team supported by community services (such as smoking cessation). The British Association for Cardiovascular Prevention and Rehabilitation (BACPR) recommends that a CR programme should be based on seven components which have health behaviour change and education at their core (Figure 1). Quality assurance of CR delivery is monitored, assessed and findings published, annually, by the British Heart Foundationâfunded National Audit of Cardiac Rehabilitation (NACR) based at the University of York. The NACR collects both programme and patient-level data from a majority of CR programmes across most of the United Kingdom (with the exception of Scotland). To ensure data security and quality, NACR data are hosted by NHS Digital
The quality of different types of child care at 10 and 18 months. A comparison between types and factors related to quality.
The quality of care offered in four different types of non-parental child care to 307 infants at 10 months old and 331 infants at 18 months old was compared and factors associated with higher quality were identified. Observed quality was lowest in nurseries at each age point, except that at 18 months they offered more learning activities. There were few differences in the observed quality of care by child-minders, grandparents and nannies, although grandparents had somewhat lower safety and health scores and offered children fewer activities. Cost was largely unrelated to quality of care except in child-minding, where higher cost was associated with higher quality. Observed ratios of children to adults had a significant impact on quality of nursery care; the more infants or toddlers each adult had to care for, the lower the quality of the care she gave them. Mothers' overall satisfaction with their child's care was positively associated with its quality for home-based care but not for nursery settings
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