Clifton Hospital

Abstract A general two‐dimensional shear deformation theory of laminated composite plates is presented. The theory account for a desired degree of approximation of the displacements through the laminate thickness. As special cases, the classical, first‐order (Reissner–Mindlin) and other shear deformation theories available in the literature can be deduced from the present theory.

Theories of hedonic, eudaimonic, and social well-being provide 3 extensively studied models for explaining flourishing mental health. Few studies have examined whether these models can be integrated into a comprehensive structure of well-being. The present study builds upon previous theoretical and empirical work to determine the complex relationships among these 3 models of well-being. Confirmatory factor analysis techniques were used to test a series of models in order to (a) confirm the proposed latent structures of hedonic, eudaimonic, and social well-being and (b) examine whether these models could be successfully integrated into a hierarchical structure of well-being. In 2 large samples, results supported the proposed latent structures of hedonic, eudaimonic, and social well-being and indicated that the various components of well-being could be represented most parsimoniously with 3 oblique second-order constructs of hedonic, eudaimonic, and social well-being.

We interviewed 128 women regularly during pregnancy and the first postnatal year. Psychiatric interviews identified eight 'cases' of psychiatric disorder (6 per cent) in early pregnancy and twenty 'cases' (16 per cent) at six weeks after birth. Postnatal affective disorder, which accounted for 15 of these cases, was significantly associated with dissatisfaction with the marital relationship and also with previous psychiatric history. The implications of the term 'postnatal depression' are considered in terms of the course of the disorder in the 29 women (23 per cent) who had episodes of affective disorder at some time during pregnancy and the postnatal year. We found that the majority of episodes of affective disorder could be understood in terms of previous psychiatric history and/or reaction to life-events, including the stress of childbirth itself.

Between 1989 and 1992 we had 102 knees suitable for unicompartmental knee replacement (UKR). They were randomised to receive either a St Georg Sled UKR or a Kinematic modular total knee replacement (TKR). The early results demonstrated that the UKR group had less complications and more rapid rehabilitation than the TKR group. At five years there were an equal number of failures in the two groups but the UKR group had more excellent results and a greater range of movement. The cases were reviewed by a research nurse at 8, 10 and 12 years after operation. We report the outcome at 15 years follow-up. A total of 43 patients (45 knees) died with their prosthetic knees intact. Throughout the review period the Bristol knee scores of the UKR group have been better and at 15 years 15 (71.4%) of the surviving UKRs and 10 (52.6%) of the surviving TKRs had achieved an excellent score. The 15 years survivorship rate based on revision or failure for any reason was 24 (89.8%) for UKR and 19 (78.7%) for TKR. During the 15 years of the review four UKRs and six TKRs failed. The better early results with UKR are maintained at 15 years with no greater failure rate. The median Bristol knee score of the UKR group was 91.1 at five years and 92 at 15 years, suggesting little functional deterioration in either the prosthesis or the remainder of the joint. These results justify the increased use of UKR.

Contemporary theories of hope and optimism provide two explanations for how positive expectancies can shape human behavior and promote well-being. Scheier and Carver's theory of optimism focuses on generalized expectations of positive outcomes, whereas Snyder's hope theory focuses on how evaluations of personal agency can facilitate goal attainment. Although the theoretical distinctions between these constructs have previously been articulated, few studies have jointly examined the two constructs in order to determine unique effects, and some have questioned whether the constructs are truly distinct. This study therefore examines whether hope and optimism (1) are distinct latent constructs, (2) have unique effects on components of flourishing mental health, and (3) differentially relate to the components of flourishing mental health. Confirmatory factor analysis results and a bootstrapped structural equation model indicate that hope and optimism are distinct latent constructs that each uniquely predict a moderate proportion of variance of the components of well-being.

Localized corrosion, which usually appears as pitting, crevice corrosion (CC), or certain aspects of stress corrosion cracking (SCC), is a multi-step process. This review is organized by a consideration of the four steps involved in localized corrosion: (1) adsorption of the reactive anion on the oxide covered aluminum; (2) chemical reaction of the adsorbed anion with the aluminum ion in the aluminum oxide lattice or the precipitated aluminum hydroxide; (3) thinning of the oxide by dissolution; and (4) direct attack of the exposed metal by the anion, perhaps assisted by an anodic potential. The experimental work reported in the literature is evaluated within this framework.

This paper introduces Causal Agency Theory, an extension of the functional model of self-determination. Causal Agency Theory addresses the need for interventions and assessments pertaining to selfdetermination for all students and incorporates the significant advances in understanding of disability and in the field of positive psychology since the introduction of the functional model of self-determination. Causal Agency Theory provides a theoretical framework for developing and enhancing supports to enable youth to engage in agentic action through instruction in goal setting and attainment strategies, to influence selfdetermination, causal agency, and overall well-being across diverse social-contextual contexts.

Abstract Finite element models of the continuum‐based theories and two‐dimensional plate/shell theories used in the analysis of composite laminates are reviewed. The classical and shear deformation theories up to the third‐order are presented in a single theory. Results of linear and non‐linear bending, natural vibration and stability of composite laminates are presented for various boundary conditions and lamination schemes. Computational modelling issues related to composite laminates, such as locking, symmetry considerations, boundary conditions, and geometric non‐linearity effects on displacements, buckling loads and frequencies are discussed. It is shown that the use of quarter plate models can introduce significant errors into the solution of certain laminates, the non‐linear effects are important even at small ratio of the transverse deflection to the thickness of antisymmetric laminates with pinned edges, and that the conventional eigenvalue approach for the determination of buckling loads of composite laminates can be overly conservative.

Abstract Aim Invasive alien species (IAS) are recognized as major drivers of biodiversity loss, but few causal relationships between IAS and species declines have been documented. In this study, we compare the distribution (Belgium and Britain) and abundance (Belgium, Britain and Switzerland) of formerly common and widespread native ladybirds before and after the arrival of Harmonia axyridis , a globally rapidly expanding IAS. Location Europe Methods We used generalized linear mixed‐effects models (GLMMs) to assess the distribution trends of eight conspicuous and historically widespread and common species of ladybird within Belgium and Britain before and after the arrival of H. axyridis . The distribution data were collated largely through public participatory surveys but verified by a recognized expert. We also used GLMMs to model trends in the abundance of ladybirds using data collated through systematic surveys of deciduous trees in Belgium, Britain and Switzerland. Results Five (Belgium) and seven (Britain) of eight species studied show substantial declines attributable to the arrival of H. axyridis . Indeed, the two‐spot ladybird, Adalia bipunctata , declined by 30% (Belgium) and 44% (Britain) over 5 years after the arrival of H. axyridis . Trends in ladybird abundance revealed similar patterns of declines across three countries. Main conclusion Together, these analyses show H. axyridis to be displacing native ladybirds with high niche overlap, probably through predation and competition. This finding provides strong evidence of a causal link between the arrival of an IAS and decline in native biodiversity. Rapid biotic homogenization at the continental scale could impact on the resilience of ecosystems and severely diminish the services they deliver.

We report the mid-term results of a new patellofemoral arthroplasty for established isolated patellofemoral arthritis. We have reviewed the experience of 109 consecutive patellofemoral resurfacing arthroplasties in 85 patients who were followed up for at least five years. The five-year survival rate, with revision as the endpoint, was 95.8% (95% confidence interval 91.8% to 99.8%). There were no cases of loosening of the prosthesis. At five years the median Bristol pain score improved from 15 of 40 points (interquartile range 5 to 20) pre-operatively, to 35 (interquartile range 20 to 40), the median Melbourne score from 10 of 30 points (interquartile range 6 to 15) to 25 (interquartile range 20 to 29), and the median Oxford score from 18 of 48 points (interquartile range 13 to 24) to 39 (interquartile range 24 to 45). Successful results, judged on a Bristol pain score of at least 20 at five years, occurred in 80% (66) of knees. The main complication was radiological progression of arthritis, which occurred in 25 patients (28%) and emphasises the importance of the careful selection of patients. These results give increased confidence in the use of patellofemoral arthroplasty.

Doing what we do best leads to high levels of engagement and productivity. Educators who capitalize on their strengths daily help students do what they do best by developing a strengthsbased approach to education. The principles of strengths-based education include measurement, individualization, networking, deliberate application, and intentional development. Through a parallel process, educators practice the principles of strengths-based education when advising and teaching while students learn to put their strengths to work in learning and social situations.

SINCE the time of Harvey knowledge of the circulation of the blood has increased to such an extent that the literature on the subject is now vast. From this knowledge has been derived the underlying principles governing the medical and surgical management of functional and organic disorders of the heart and of the blood vessels in most parts of the body. The nose, despite its anatomical prominence, has been very much neglected in this quest because fatal or disabling diseases were naturally given priority of attention.

Cassava (Manihot esculenta) is an important subsistence food crop in Africa where it is affected by two main virus diseases, cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). CMD occurs in all the cassava-growing countries on the continent and it has been much researched. CBSD occurs mainly on the East African coast, and although the disease was first reported in 1936, it has received much less attention than CMD. The aetiology and epidemiology of CBSD are still not fully elucidated, and no insect vector has been identified. There is renewed interest in CBSD owing to the discovery of its widespread occurrence in southern Tanzania and Mozambique, where the associated symptom of root necrosis is a major cause of economic loss in the cassava crop. In view of the present importance of the disease in eastern Africa, it is timely to produce a review of work carried out on the disease since it was first described. Keywords: CassavaVirus DiseasesCassava Brown Streak DiseaseAfrica

The rationale of acute and chronic orthopedic management of traumatic throacolumbar kyphosis is determined by the type and location of the injury. The performance of laminectomy is condemned due to its historical failure in both the acute and chronic phase and its violation of simple mechanical principles.

Abstract A plate bending element based on the generalized laminate plate theory (GLPT) developed by the senior author is described and its accuracy is investigated by comparison with the exact solutions of the generalized plate theory and the 3D‐elasticity theory. The element accounts for transverse shear deformation and layer‐wise description of the inplane displacements of the laminate. The element has improved description of the inplane as well as the transverse deformation response. A method for the computation of interlaminar (transverse) stresses is also presented.

The anterior cruciate ligament (ACL) has entertained scientific minds since the Weber brothers provided biomechanical insight into the importance of the ACL in maintaining normal knee kinematics. Robert Adams described the first clinical case of ACL rupture in 1837 some 175 years to date, followed by Mayo-Robson of Leeds who performed the first ACL repair in 1895. At that time, most patients presented late and clinicians started to appreciate signs and symptoms and disabilities associated with such injuries. Hey Groves of Bristol provided the initial description of an ACL reconstruction with autologous tissue graft in 1917, almost as we know it today. His knowledge and achievements were, however, not uniformly appreciated during his life time. What followed was a period of startling ingenuity which created an amazing variety of different surgical procedures often based more on surgical fashion and the absence of a satisfactory alternative than any indication that continued refinements were leading to improved results. It is hence not surprising that real inventors were forgotten, good ideas discarded and untried surgical methods adopted with uncritical enthusiasm only to be set aside without further explanation. Over the past 100 years, surgeons have experimented with a variety of different graft sources including xenograft, and allografts, whilst autologous tissue has remained the most popular choice. Synthetic graft materials enjoyed temporary popularity in the 1980 and 1990s, in the misguided belief that artificial ligaments may be more durable and better equipped to withstand stresses and strains. Until the 1970s, ACL reconstructions were considered formidable procedures, often so complex and fraught with peril that they remained reserved for a chosen few, never gaining the level of popularity they are enjoying today. The increasing familiarity with arthroscopy, popularised through Jackson and Dandy, and enhancements in surgical technology firmly established ACL reconstruction as a common procedure within the realm of most surgeons' ability. More recently, the principle of anatomic ACL reconstruction, aiming at the functional restoration of native ACL dimensions and insertion sites, has been introduced, superseding the somewhat ill-advised concept of isometric graft placement. Double-bundle reconstruction is gaining in popularity, and combined extra- and intra-articular procedures are seeing a revival, but more accurate and reliable pre- and post-operative assessment tools are required to provide customised treatment options and appropriate evaluation and comparability of long-term results. Modern ACL surgery is united in the common goal of re-establishing joint homoeostasis with normal knee kinematics and function which may ultimately assist in reducing the prevalence of post-operative joint degeneration. This review hopes to provide an insight into the historical developments of ACL surgery and the various controversies surrounding its progress. Level of evidence V.

Correct identification of the source population of an invasive species is a prerequisite for testing hypotheses concerning the factors responsible for biological invasions. The native area of invasive species may be large, poorly known and/or genetically structured. Because the actual source population may not have been sampled, studies based on molecular markers may generate incorrect conclusions about the origin of introduced populations. In this study, we characterized the genetic structure of the invasive ladybird Harmonia axyridis in its native area using various population genetic statistics and methods. We found that native area of H. axyridis most probably consisted of two geographically distinct genetic clusters located in eastern and western Asia. We then performed approximate Bayesian computation (ABC) analyses on controlled simulated microsatellite data sets to evaluate (i) the risk of selecting incorrect introduction scenarios, including admixture between sources, when the populations of the native area are genetically structured and sampling is incomplete and (ii) the ability of ABC analysis to minimize such risks by explicitly including unsampled populations in the scenarios compared. Finally, we performed additional ABC analyses on real microsatellite data sets to retrace the origin of biocontrol and invasive populations of H. axyridis, taking into account the possibility that the structured native area may have been incompletely sampled. We found that the invasive population in eastern North America, which has served as the bridgehead for worldwide invasion by H. axyridis, was probably formed by an admixture between the eastern and western native clusters. This admixture may have facilitated adaptation of the bridgehead population.

Current theories of optimism suggest that the tendency to maintain positive expectations for the future is an adaptive psychological resource associated with improved well-being and physical health, but the majority of previous optimism research has been conducted in industrialized nations. The present study examined (a) whether optimism is universal, (b) what demographic factors predict optimism, and (c) whether optimism is consistently associated with improved subjective well-being and perceived health worldwide. The present study used representative samples of 142 countries that together represent 95% of the world's population. The total sample of 150,048 individuals had a mean age of 38.28 (SD = 16.85) and approximately equal sex distribution (51.2% female). The relationships between optimism, subjective well-being, and perceived health were examined using hierarchical linear modeling. Results indicated that most individuals and most countries worldwide are optimistic and that higher levels of optimism are associated with improved subjective well-being and perceived health worldwide. The present study provides compelling evidence that optimism is a universal phenomenon and that the associations between optimism and improved psychological functioning are not limited to industrialized nations.

Globus pallidus (GP) neurons recorded in brain slices show significant variability in intrinsic electrophysiological properties. To investigate how this variability arises, we manipulated the biophysical properties of GP neurons using computer simulations. Specifically, we created a GP neuron model database with 100,602 models that had varying densities of nine membrane conductances centered on a hand-tuned model that replicated typical physiological data. To test the hypothesis that the experimentally observed variability can be attributed to variations in conductance densities, we compared our model database results to a physiology database of 146 slice recordings. The electrophysiological properties of generated models and recordings were assessed with identical current injection protocols and analyzed with a uniform set of measures, allowing a systematic analysis of the effects of varying voltage-gated and calcium-gated conductance densities on the measured properties and a detailed comparison between models and recordings. Our results indicated that most of the experimental variability could be matched by varying conductance densities, which we confirmed with additional partial block experiments. Further analysis resulted in two key observations: (1) each voltage-gated conductance had effects on multiple measures such as action potential waveform and spontaneous or stimulated spike rates; and (2) the effect of each conductance was highly dependent on the background context of other conductances present. In some cases, such interactions could reverse the effect of the density of one conductance on important excitability measures. This context dependence of conductance density effects is important to understand drug and neuromodulator effects that work by affecting ion channels.

Alcohol contributes more than 10 per cent of the total caloric intake of adult drinkers in the United States. However, the effect of alcohol on body weight has not been adequately studied in the general population. The association between weight and frequency of alcohol consumption was examined in two national cross-sectional surveys: the Second National Health and Nutrition Examination Survey (HANESII; n = 10,929) and the Behavioral Risk Factor Surveys (BRFS; n = 18,388). Linear multiple regression was used to estimate the independent effect of alcohol on weight, adjusting for smoking, age, diet practices, physical activity, race, education, and height. Among men, alcohol had only a slight effect on weight in either survey. However, among women, alcohol was associated with a substantial reduction in weight, which was as large as the effect of smoking. Compared with nondrinkers, women who consumed alcohol 7-13 times per week had the greatest reduction in weight: -3.6 kg (95% confidence limits [CL] = -5.6, -1.5 kg) in HANESII and -3.2 kg (95% CL = -4.9, -1.5 kg) in BRFS. Alcohol confounded the association between smoking and weight, and among women it accounted for nearly 45 per cent of the weight-lowering effect of smoking. Alcohol also diminished the weight-lowering effect of smoking in men, while in women the smoking effect was slightly enhanced. Further studies are needed to understand the causal mechanisms by which alcohol is associated with body weight.