Method to estimate relative transmission efficiencies of Anopheles species (Diptera: Culicidae) in human malaria transmission.

A mathematical expression was derived to estimate the relative malaria transmission efficiency of an anopheline species with respect to a standard well-characterized species for which all vector parameters can be sufficiently determined. The method is particularly useful in situations where multiple anopheline species contribute to human malaria transmission and requires the estimation of the man-biting rate, the sporozoite rate, and the human malaria incidence. Under stable conditions of vector abundance, the average sporozoite rate in a species during a transmission season would by itself reflect its relative transmission efficiency. This "efficiency" then was used to calculate the "effective human-biting rate"; i.e., the human-biting rate of that species if it were to have ecological properties identical to those of the standard species. The standard well-characterized species then could be used with the effective human-biting rate of all species to quantify transmission, thus overcoming the need to measure vector parameters for all anopheline species contributing to transmission. An expression also was derived to calculate the relative contribution made by each species to malaria transmission. The usefulness of this method was illustrated using entomological and epidemiological data from Kataragama, Sri Lanka.     

Adaptive ageing surgeons

The surgical workforce is ageing. This will impact on future workforce supply and planning, as well as the professional performance and welfare of surgeons themselves. This paper is a ‘call to arms’ to surgeons to consider the complex problem of advancing years and surgical performance. We aim to promote discussion about the issue of ageing as it relates to surgeons, while exploring ways in which successful ageing in surgeons may be promoted. The task‐specific aspects of surgical practice suggest that it is a physically and cognitively demanding task, reliant on a range of fine motor, sensory, visuospatial, reasoning, memory and processing skills. Many of these skills potentially decline with age, although there is great inter‐individual variation, particularly in cognitive performance. Nevertheless, there is some consensus in the literature that age‐related cognitive changes exist in a proportion of surgeons, and there is an increase in operative mortality rates for certain surgical procedures performed by older and more experienced surgeons. In the absence of mandatory retirement, guidance is needed in regard to individualizing the timing of retirement and encouraging reflective and adaptive practice based on insight into how one's skills and performance may change with age. This may be best facilitated by some form of informed and guided self‐monitoring or ‘self‐screening’. It should be emphasized that self‐screening is not a form of self‐treatment but aims to enhance insight, using a tool kit of resources to promote adaptive ageing. Moreover, self‐screening should not be restricted to cognition, which is only part of the picture of ageing, but extended to emphasize the maintenance of mental and physical wellness, and the acceptance of independent professional treatment and support when required.     

Treatment-resistant depression: critique of current approaches

The aim of the present study was to critically appraise current conceptual approaches; demographic, neurobiological and clinical correlates; and management strategies of treatment-resistant depression (TRD), especially in light of recent research findings. To this end, a review of the relevant English-language literature was undertaken using Medline, Embase and Psychinfo. TRD has been defined in conceptually restrictive terms as symptomatic non-response to physical therapies alone, with little systematic study of aetiology made. It is likely that a range of sociodemographic (such as higher socioeconomic status), genetic (such as variation in functional monoamine polymorphisms) and clinical variables (such as signal hyperintensities seen on structural neuroimaging scans) are responsible for non-response in individuals. There is insufficient evidence to suggest that TRD is associated with specific subtypes of depression, physical comorbidity, personality or chronicity. The large-scale Sequenced Treatment Alternatives to Relieve Depression (STAR*D) and other studies have suggested that a structured psychotherapy such as cognitive behaviour therapy may be as effective as medication in initial drug non-responders. Also conventional alternatives such as the use of older antidepressant classes, pharmacological augmentation or electroconvulsive therapy in established cases of TRD are not as effective as traditionally thought. There is insufficient preliminary evidence to make formal recommendations about the use of novel brain stimulation techniques in TRD. TRD should be re-defined as the failure to reach symptomatic and functional remission after adequate treatment with physical and psychological therapies. Treatment resistance may be more usefully conceived within the context of well-defined cohorts such as patients with specific subtypes of depression. Although neurobiological markers such as gene polymorphisms, which are potentially predictive of medication tolerance and efficacy, may be used in the future, it is likely that sociocultural variables such as beliefs about depression, and evidence-based treatments for it, will also determine treatment resistance.     

Separation anxiety in the elderly

Separation anxiety has been studied in children and young adults but little is known about this form of anxiety in older people. This study aimed to examine socio-demographic, psychological and physical health correlates of separation anxiety in the elderly. Eighty-six ambulatory subjects aged 62-87 years were recruited from primary medical care practices to participate in this study. The presence of lifetime DSM-IV affective and anxiety disorders was determined by structured clinical interview. Subjects also completed a battery of self-report questionnaires measuring levels of state and trait anxiety, juvenile and adult separation anxiety. Adult separation anxiety scores were moderately correlated with juvenile separation anxiety scores (r= .52, P < .001), trait anxiety (r = .55, P < .001) and state anxiety scores (r = .66, P < .001), as well as younger age (r = .39, P < .001). Higher adult separation anxiety scores were also associated with a lifetime history of any anxiety disorder (t = 3.74, df = 84, P < .001) or any affective disorder (t = 2.12, df = 84, P < .05). However, adult separation anxiety was not associated with increasing age, being widowed, living alone or poorer physical health. Clinicians working with the elderly need to routinely explore this form of anxiety as it may complicate the pattern of presentation of other anxiety and affective disorders, and require specific forms of intervention.     

The influence of three acid modifications on the physicochemical characteristics of tea-waste biochar pyrolyzed at different temperatures: a comparative study

Tea-waste is an abundant feedstock for producing biochar (BC) which is considered to be a cost effective carbonaceous adsorbent useful for water remediation and soil amendment purposes. In the present study, tea-waste BC (TWBC) produced at three different temperatures were subjected to nitric, sulfuric and hydrochloric acid modifications (abbreviated as NM, SM and HM respectively). Characteristics of the raw and modified BC such as ultimate and proximate analyses, surface morphology, surface acidity and functionality, point of zero charge, cation exchange capacity (CEC) and thermal stability were compared to evaluate the influence of pyrolysis temperature and of modifications incorporated. The amount of carboxylic and phenolic surface functionalities on TWBC was seen to decrease by 93.44% and 81.06% respectively when the pyrolysis temperature was increased from 300 to 700 °C. Additionally, the yield of BC was seen to decrease by 46% upon the latter temperature increment. The elemental analysis results provided justification for high-temperature BC being more hydrophobic as was observed by the 61% increase in H/C ratio which is an indication of augmented aromatization. The CEC was the highest for the low-temperature BC and was seen to further increase by NM which is attributed to the 81.89% increase in carboxylic functionalities. The surface area was seen to significantly increase for BC700 upon NM (∼27 times). The SM led to pore wall destruction which was observed in scanning electron microscopy images. Findings would enable the rational use of these particular modifications in relevant remediation and soil amendment applications.

Tea-waste biochar produced under different pyrolysis temperatures were subjected to three acid modifications and a comparative evaluation of their key physicochemical characteristics made.     

Gauze-based negative pressure wound therapy to infected deep sternotomy wound complicated by cardiac tamponade: a case report

Negative pressure wound therapy is the standard of care for infections after median sternotomy. Foam-based systems are commonly used even in scenarios when the myocardium is exposed. Gauze-based systems have recently gained popularity. We describe a case of deep sternal dehiscence that lead to a life-threatening complication secondary to wound filler choice.