Nearshore surface current patterns in the Tsitsikamma National Park, South Africa

The pattern of surface currents in the Tsitsikamma National Park, South Africa, was studied with holey-sock drogues released in batches of up to four at a time, from 1996 and 1998. Drogues were left to drift for either 6 or 24 h, while recording position and time. The majority of drogue movements were longshore, either eastward or westward; they usually travelled with similar direction and velocity. In most instances, westward movements were slightly offshore and were sometimes associated with a rise in the thermocline. Eastward movements were, on average, slightly slower, with an onshore component, sometimes associated with a lowering of the thermocline. The remaining trials showed some variability between drogues and were characterized by reduced velocity and unstable direction, indicating either the presence of horizontal turbulence or a current reversal. Current and wind were poorly correlated. Current directions were sustained for at least four days, indicating that short-lived ichthyoplankton, originating in the 70-km park, may be dispersed beyond its boundaries. Keywords: currents, drogues, larval dispersal, marine protected areasAfrican Journal of Marine Science 2002, 24: 151–16

Advancing precision public health using human genomics: examples from the field and future research opportunities

Precision public health is a relatively new field that integrates components of precision medicine, such as human genomics research, with public health concepts to help improve population health. Despite interest in advancing precision public health initiatives using human genomics research, current and future opportunities in this emerging field remain largely undescribed. To that end, we provide examples of promising opportunities and current applications of genomics research within precision public health and outline future directions within five major domains of public health: biostatistics, environmental health, epidemiology, health policy and health services, and social and behavioral science. To further extend applications of genomics within precision public health research, three key cross-cutting challenges will need to be addressed: developing policies that implement precision public health initiatives at multiple levels, improving data integration and developing more rigorous methodologies, and incorporating initiatives that address health equity. Realizing the potential to better integrate human genomics within precision public health will require transdisciplinary efforts that leverage the strengths of both precision medicine and public health

Path integral Monte Carlo simulations for rigid rotors and their application to water

In this work the path integral formulation for rigid rotors, proposed by M\"user and Berne [Phys. Rev. Lett. {\bf 77}, 2638 (1996)], is described in detail. It is shown how this formulation can be used to perform Monte Carlo simulations of water. Our numerical results show that whereas some properties of water can be accurately reproduced using classical simulations with an empirical potential which, implicitly, includes quantum effects, other properties can only be described quantitatively when quantum effects are explicitly incorporated. In particular, quantum effects are extremely relevant when it comes to describing the equation of state of the ice phases at low temperatures, the structure of the ices at low temperatures, and the heat capacity of both liquid water and the ice phases. They also play a minor role in the relative stability of the ice phases.Comment: to appear in Molecular Physics (2011

Assessing hydrothermal liquefaction for the production of bio-oil and enhanced metal recovery from microalgae cultivated on acid mine drainage

The hydrothermal liquefaction (HTL) of algal biomass is a promising route to viable second generation biofuels. In this investigation HTL was assessed for the valorisation of algae used in the remediation of acid mine drainage (AMD). Initially the HTL process was evaluated using Arthrospira platensis (Spirulina) with additional metal sulphates to simulate metal remediation. Optimised conditions were then used to process a natural algal community (predominantly Chlamydomonas sp.) cultivated under two scenarios: high uptake and low uptake of metals from AMD. High metal concentrations appear to catalyse the conversion to bio-oil, and do not significantly affect the heteroatom content or higher heating value of the bio-oil produced. The associated metals were found to partition almost exclusively into the solid residue, favourable for potential metal recovery. High metal loadings also caused partitioning of phosphates from the aqueous phase to the solid phase, potentially compromising attempts to recycle process water as a growth supplement. HTL was therefore found to be a suitable method of processing algae used in AMD remediation, producing a crude oil suitable for upgrading into hydrocarbon fuels, an aqueous and gas stream suitable for supplementing the algal growth and the partitioning of most contaminant metals to the solid residue where they would be readily amenable for recovery and/or disposal

Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses

The Depressed Brain: An Evolutionary Systems Theory

Major depression is a debilitating condition characterised by diverse neurocognitive and behavioural deficits. Nevertheless, our species-typical capacity for depressed mood implies that it serves an adaptive function. Here we apply an interdisciplinary theory of brain function to explain depressed mood and its clinical manifestations. Combining insights from the free-energy principle (FEP) with evolutionary theorising in psychology, we argue that depression reflects an adaptive response to perceived threats of aversive social outcomes (e.g., exclusion) that minimises the likelihood of surprising interpersonal exchanges (i.e., those with unpredictable outcomes). We suggest that psychopathology typically arises from ineffectual attempts to alleviate interpersonal difficulties and/or hyper-reactive neurobiological responses to social stress (i.e., uncertainty), which often stems from early experience that social uncertainty is difficult to resolve

Reticular formation responses to magnetic brain stimulation of primary motor cortex

Transcranial magnetic stimulation (TMS) of cerebral cortex is a popular technique for the non-invasive investigation of motor function. TMS is often assumed to influence spinal circuits solely via the corticospinal tract. We were interested in possible trans-synaptic effects of cortical TMS on the ponto-medullary reticular formation in the brainstem, which is the source of the reticulospinal tract and could also generate spinal motor output. We recorded from 210 single units in the reticular formation of three anaesthetized macaque monkeys whilst TMS was performed over primary motor cortex. Short latency responses were observed consistent with activation of a cortico-reticular pathway. However, we also demonstrated surprisingly powerful responses at longer latency, which often appeared at lower threshold than the earlier effects. These late responses seemed to be generated partly as a consequence of the sound click made by coil discharge, and changed little with coil location. This novel finding has implications for the design of future studies using TMS, as well as suggesting a means of non-invasively probing an otherwise inaccessible important motor centre

Snapping hip caused by a venous hemangioma of the gluteus maximus muscle: a case report

<p>Abstract</p> <p>Introduction</p> <p>Snapping hip, or coxa saltans, is defined as a clinical condition where a usually painful, audible snap occurs during hip flexion and extension. Its causes can be divided into external, internal or intra-articular origin. Accurate diagnosis is a prerequisite to successful treatment. We report a rare cause of snapping hip which is different from any previously reported cases.</p> <p>Case presentation</p> <p>A 23-year-old man presented to us with right hip pain of more than 10 years duration. Atrophy of the right gluteus maximus with snapping and tenderness were also noted. The imaging study revealed a focal intramuscular lesion in the lateral portion of the right gluteus maximus muscle. Surgery was performed and pathological examination concluded this mass to be a venous hemangioma.</p> <p>Conclusion</p> <p>Intramuscular hemangioma, though rare, should be considered in the differential diagnosis of a snapping hip even though muscle fibrosis is most frequently encountered.</p

A simple clinical model for planning transfusion quantities in heart surgery

<p>Abstract</p> <p>Background</p> <p>Patients undergoing heart surgery continue to be the largest demand on blood transfusions. The need for transfusion is based on the risk of complications due to poor cell oxygenation, however large transfusions are associated with increased morbidity and risk of mortality in heart surgery patients. The aim of this study was to identify preoperative and intraoperative risk factors for transfusion and create a reliable model for planning transfusion quantities in heart surgery procedures.</p> <p>Methods</p> <p>We performed an observational study on 3315 consecutive patients who underwent cardiac surgery between January 2000 and December 2007. To estimate the number of packs of red blood cells (PRBC) transfused during heart surgery, we developed a multivariate regression model with discrete coefficients by selecting dummy variables as regressors in a stepwise manner. Model performance was assessed statistically by splitting cases into training and testing sets of the same size, and clinically by investigating the clinical course details of about one quarter of the patients in whom the difference between model estimates and actual number of PRBC transfused was higher than the root mean squared error.</p> <p>Results</p> <p>Ten preoperative and intraoperative dichotomous variables were entered in the model. Approximating the regression coefficients to the nearest half unit, each dummy regressor equal to one gave a number of half PRBC. The model assigned 4 units for kidney failure requiring preoperative dialysis, 2.5 units for cardiogenic shock, 2 units for minimum hematocrit at cardiopulmonary bypass less than or equal to 20%, 1.5 units for emergency operation, 1 unit for preoperative hematocrit less than or equal to 40%, cardiopulmonary bypass time greater than 130 minutes and type of surgery different from isolated artery bypass grafting, and 0.5 units for urgent operation, age over 70 years and systemic arterial hypertension.</p> <p>Conclusions</p> <p>The regression model proved reliable for quantitative planning of number of PRBC in patients undergoing heart surgery. Besides enabling more rational resource allocation of costly blood-conservation strategies and blood bank resources, the results indicated a strong association between some essential postoperative variables and differences between the model estimate and the actual number of packs transfused.</p

The developmental effects of media-ideal internalization and self-objectification processes on adolescents’ negative body-feelings, dietary restraint, and binge eating

Despite accumulated experimental evidence of the negative effects of exposure to media-idealized images, the degree to which body image, and eating related disturbances are caused by media portrayals of gendered beauty ideals remains controversial. On the basis of the most up-to-date meta-analysis of experimental studies indicating that media-idealized images have the most harmful and substantial impact on vulnerable individuals regardless of gender (i.e., “internalizers” and “self-objectifiers”), the current longitudinal study examined the direct and mediated links posited in objectification theory among media-ideal internalization, self-objectification, shame and anxiety surrounding the body and appearance, dietary restraint, and binge eating. Data collected from 685 adolescents aged between 14 and 15 at baseline (47 % males), who were interviewed and completed standardized measures annually over a 3-year period, were analyzed using a structural equation modeling approach. Results indicated that media-ideal internalization predicted later thinking and scrutinizing of one’s body from an external observer’s standpoint (or self-objectification), which then predicted later negative emotional experiences related to one’s body and appearance. In turn, these negative emotional experiences predicted subsequent dietary restraint and binge eating, and each of these core features of eating disorders influenced each other. Differences in the strength of these associations across gender were not observed, and all indirect effects were significant. The study provides valuable information about how the cultural values embodied by gendered beauty ideals negatively influence adolescents’ feelings, thoughts and behaviors regarding their own body, and on the complex processes involved in disordered eating. Practical implications are discussed