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The study was triggered by the first author's own experience on an undergraduate elective at the National Mental Wellness Centre in St Lucia. This was an eye-opening experience of psychiatry in a less economically developed environment. It highlighted disparities between practice in the developed and the developing world. Notably significant differences were apparent in facilities, epidemiology of presenting complaints, the interaction of cultural beliefs as well as the method of assessment and management.
To review the literature on the educational impact of electives in psychiatry.
A literature search using Ovid MEDLINE was conducted using the keywords’medical student’ AND’elective’ AND’psychiatry’. A total of 229 results were returned. These were then analysed for their relevance.
Only one paper was found emphasising the importance of electives in psychiatry. This reported on one individual's personal experience. There also were reports highlighting the importance of undergraduate elective experience and the need to increase exposure to psychiatry to improve the uptake of postgraduate training programmes. There were no papers objectively assessing the educational quality or impact of a psychiatric elective experience.
An overseas elective experience was subjectively beneficial for the author but there is a lack of objective research to show the educational benefit of psychiatry electives on a wider scale. Further research regarding the educational benefits of electives in psychiatry is needed.
Evidence from previous small trials has suggested the effectiveness of early social communication interventions for autism.
The Preschool Autism Communication Trial (PACT) investigated the efficacy of such an intervention in the largest psychosocial autism trial to date.
To provide a stringent test of a pre-school communication intervention for autism.
152 children with core autism aged 2 years - 4 years 11 months in a 3 site 2 arm single (assessor) blinded randomised controlled trial of the parent-mediated communication-focused intervention added to treatment as usual (TAU) against TAU alone. Primary outcome; severity of autism symptoms (modified social communication algorithm from Autism Diagnostic Observation Schedule-Generic, ADOS-G). Secondary outcomes; blinded measures of parent-child interaction, child language, and adaptation in school.
At 13 month endpoint the treatment resulted in strong improvement in parental synchronous response to child (adjusted between-group effect size 1.22 (95% CI 0.85, 1.59) and child initiations with parent (ES 0.41 (0.08, 0.74) but small effect on autism symptomatology (ADOS-G, ES -0.24 (95% CI -0.59, 0.11) ns). Parents (not blind to allocation) reported strong treatment effects on child language and social adaptation but effects on blinded research assessed language and school adaptation were small.
Addition of the PACT intervention showed clear benefit in improving parent-child dyadic social communication but no substantive benefit over TAU in modifying objectively rated autism symptoms. This attenuation on generalisation from ‘proximal’ intervention effects to wider symptom change in other contexts remains a significant challenge for autism treatment and measurement methodology.
To determine the frequency and content of food-related television (TV) advertisements shown on South African TV.
Four national TV channels were recorded between 15.00 and 21.00 hours (6 h each day, for seven consecutive days, over a 4-week period) to: (i) determine the number of food-related TV advertisements; and (ii) evaluate the content and approach used by advertisers to market their products. The data were viewed by two of the researchers and coded according to time slots, food categories, food products, health claims and presentation.
Of the 1512 recorded TV advertisements, 665 (44 %) were related to food. Of these, 63 % were for food products, 21 % for alcohol, 2 % for multivitamins, 1 % for slimming products and 13 % for supermarket and pharmacy promotions. Nearly 50 % of food advertisements appeared during family viewing time. During this time the most frequent advertisements were for desserts and sweets, fast foods, hot beverages, starchy foods and sweetened drinks. The majority of the alcohol advertisements (ninety-three advertisements, 67 %) fell within the children and family viewing periods and were endorsed by celebrities. Health claims were made in 11 % of the advertisements. The most frequently used benefits claimed were ‘enhances well-being’, ‘improves performance’, ‘boosts energy’, ‘strengthens the immune system’ and ‘is nutritionally balanced’.
The majority of food advertisements shown to both children and adults do not foster good health despite the health claims made. The fact that alcohol advertisements are shown during times when children watch TV needs to be addressed.
A rapidly developing tourism industry, concentrated in coastal regions, is suspected to seriously impact upon biodiversity in the global conservation priority of the insular Caribbean. In St Lucia, construction of tourism infrastructure in the coastal dry forest threatens the Endangered White-breasted Thrasher Ramphocinclus brachyurus. Long-term protection of habitat is vital, but design of such conservation action is constrained by lack of data on the species' distribution and population responses to habitat change and fragmentation. Distance sampling surveys were conducted in 2006 and 2007 to estimate numbers and map the distribution of the two remaining sub-populations. White-breasted Thrashers in St Lucia were estimated to number around 1,200 individuals, with roughly 1,050 birds occupying just over 600 ha of dry forest in the Mandelé area. We demonstrate that tourist development companies will likely soon own land constituting around 40% of the species' extent of occurrence on St Lucia, and nearly 35% globally, and that ongoing and planned tourist developments threaten around one third of the St Lucian White-breasted Thrasher population. Given the size of these potential impacts, it is vital that patches of dry forest to the west and north of a development site in the Mandelé area are safeguarded. These sites support White-breasted Thrashers at high density and are contiguous with an existing forest reserve. Other important conservation measures include preserving stands of connected mature dry and riparian forest inside the tourist development sites, alongside invasive predator control.
This paper describes a technology for three-dimensional (3-D) integration of multiple layers of silicon integrated circuits. The technology promises to dramatically enhance on-chip signal processing capabilities of a variety of detector devices hybridized with Si electronics. The focus of the paper is on high performance infrared focal plane arrays based on HgCdTe, which offer the ultimate in infrared sensitivity and find application in high performance military systems. Performance data from test FPA devices with integrated multilayer Si stacks are discussed in this paper.
Most mammals exhibit seasonal variation in the reproductive capacity of one or both sexes. While the female southern hairy-nosed wombat Lasiorhinus latifrons is a known seasonal breeder, the extent of seasonality in the male has not been documented. To examine this, gross body measurements including scrotal diameter and the dimensions of the accessory gland bulge were recorded and male reproductive tracts were examined between 1993 and 2000. Testes, epididymides and accessory glands from all males were dissected free of connective tissue and weighed. In addition, matched semen samples were collected over four time points in 2000 corresponding to the breeding season (September), immediately post-breeding season (November), during the non-breeding season (January), and immediately before the onset of the next breeding season (June) as determined from female reproductive status. Semen was collected by electro-ejaculation and analysed for volume, sperm number and motility characteristics. Ejaculate volume, total ejaculate sperm number, percentage motile sperm, and the sperm motility rating and index were all significantly elevated in September and significantly lower in November and January. This correlated with a significant increase in body weight, peri-cloacal gland width, and the weights of the prostate, Cowper's glands, urethral bulb and crus penis. The data confirm that male reproduction in the southern hairy-nosed wombat, like that of the female, is highly seasonal with a peak in reproductive capacity occurring in August–September and a reduction by November.
This study investigated burrow use and ranging behaviour in the southern hairy-nosed wombat Lasiorhinus latifrons in semi-arid South Australia. Sixteen adult wombats were fitted with radio transmitters and monitored monthly from July 2001 to February 2002. Wombats generally used between one and five warrens, preferred large warrens with a greater number of entrances and showed a preference for one or two warrens. Across the study period there was no apparent change in burrows used within warrens. Radio-tracking indicated that animals spent very little time above ground (26% of 1115 night-time fixes), centred their activity around their preferred warrens, and moved, on average, 99 m/h and 221 m/night. Mean home-range size, estimated using minimum convex polygons and the harmonic mean method from location data, obtained through triangulation, and daytime warren fixes, ranged from 1.3 to 4.8 ha. Home-range size was similar between males and females and home ranges overlapped substantially. The data highlight the importance of burrows to southern hairy-nosed wombats in shaping their home ranges. It seems likely that the use of burrows and a specialized diet are important energy saving strategies for this species in such unpredictable regions of South Australia.
The overall objective of this study was to evaluate and provide evidence and recommendations on current published literature about diet and lifestyle in the prevention of type 2 diabetes.
Epidemiological and experimental studies, focusing on nutritional intervention in the prevention of type 2 diabetes are used to make disease-specific recommendations. Long-term cohort studies are given the most weight as to strength of evidence available.
Setting and subjects:
Numerous clinical trials and cohort studies in low, middle and high income countries are evaluated regarding recommendations for dietary prevention of type 2 diabetes. These include, among others, the Finnish Diabetes Prevention Study, US Diabetes Prevention Program, Da Qing Study; Pima Indian Study; Iowa Women's Health Study; and the study of the US Male Physicians.
There is convincing evidence for a decreased risk of diabetes in adults who are physically active and maintain a normal body mass index (BMI) throughout adulthood, and in overweight adults with impaired glucose tolerance who lose weight voluntarily. An increased risk for developing type 2 diabetes is associated with overweight and obesity; abdominal obesity; physical inactivity; and maternal diabetes. It is probable that a high intake of saturated fats and intrauterine growth retardation also contribute to an increased risk, while non-starch polysaccharides are likely to be associated with a decreased risk. From existing evidence it is also possible that omega-3 fatty acids, low glycaemic index foods and exclusive breastfeeding may play a protective role, and that total fat intake and trans fatty acids may contribute to the risk. However, insufficient evidence is currently available to provide convincing proof.
Based on the strength of available evidence regarding diet and lifestyle in the prevention of type 2 diabetes, it is recommended that a normal weight status in the lower BMI range (BMI 21–23) and regular physical activity be maintained throughout adulthood; abdominal obesity be prevented; and saturated fat intake be less than 7% of the total energy intake.
Objective: To determine the quality of life in individuals with corrected tetralogy of Fallot. Methods and subjects: Questionnaires concerning quality of life were sent to all 87 surviving patients aged between 16 and 40 years who had undergone intracardiac repair of tetralogy of Fallot and follow-up in the Wessex Cardiothoracic Unit, and to 87 age and sex matched controls, with medically treated haemodynamically insignificant ventricular septal defects. Results: The only significant difference found between the cases and controls was in requirements for schooling, where those with tetralogy of Fallot were more likely to require additional educational help at school (p = 0.044). For all other aspects of quality of life examined by the questionnaire, including social and genetic history, exercise ability, and health related quality of life, no significant differences were found. Different operative techniques, such as transjunctional patching, right ventriculotomy, and previous palliative shunting, did not affect the quality of life of our population with Tetralogy of Fallot, on average twenty years after their surgery, although the range of operative techniques was limited. Neither age at surgery, nor time since surgery, was correlated with measurements of quality of life. Conclusions: Those who have undergone surgical correction of tetralogy of Fallot have a normal quality of life, with few differences compared to controls.
To determine the dietary intake, practices, knowledge and barriers to dietary compliance of black South African type 2 diabetic patients attending primary health-care services in urban and rural areas.
A cross-sectional survey. Dietary intake was assessed by three 24-hour recalls, and knowledge and practices by means of a structured questionnaire (n=133 men, 155 women). In-depth interviews were then conducted with 25 of the patients to explore their underlying beliefs and feelings with respect to their disease. Trained interviewers measured weight, height and blood pressure. A fasting venous blood sample was collected from each participant in order to evaluate glycaemic control.
An urban area (Sheshego) and rural areas near Pietersburg in the Northern Province of South Africa.
The sample comprised 59 men and 75 women from urban areas and 74 men and 80 women from rural areas. All were over 40 years of age, diagnosed with type 2 diabetes for at least one year, and attended primary health-care services in the study area over a 3-month period in 1998.
Reported dietary results indicate that mean energy intakes were low (<70% of Recommended Dietary Allowance), 8086–8450 kJ day−1 and 6967–7382 kJ day−1 in men and women, respectively. Urban subjects had higher (P<0.05) intakes of animal protein and lower ratios of polyunsaturated fat to saturated fat than rural subjects. The energy distribution of macronutrients was in line with the recommendations for a prudent diet, with fat intake less than 30%, saturated fat less than 10% and carbohydrate intake greater than 55% of total energy intake. In most respects, nutrient intakes resembled a traditional African diet, although fibre intake was low in terms of the recommended 3–6 g/1000 kJ. More than 90% of patients ate three meals a day, yet only 32–47% had a morning snack and 19–27% had a late evening snack. The majority of patients indicated that they followed a special diet, which had been given to them by a doctor or a nurse. Only 3.4–6.1% were treated by diet alone. Poor glycaemic control was found in both urban and rural participants, with more than half of subjects having fasting plasma glucose above 8 mmol l−1 and more than 35% having plasma glycosylated haemoglobin level above 8.6%. High triglyceride levels were found in 24 to 25% of men and in 17 to 18% of women. Obesity (body mass index ≥30 kgm−2) was prevalent in 15 to 16% of men compared with 35 to 47% of women; elevated blood pressure (≥160/95 mmHg) was least prevalent in rural women (25.9%) and most prevalent in urban men (42.4%).
The majority of black, type 2 diabetic patients studied showed poor glycaemic control. Additionally, many had dyslipidaemia, were obese and/or had an elevated blood pressure. Quantitative and qualitative findings indicated that these patients frequently received incorrect and inappropriate dietary advice from health educators.
The mouse-like marsupial Antechinus agilis is common to south-eastern Australia with breeding and life-history traits being highly synchronous. Mating activity is confined to a 10- to 15-day period in August, at the end of which all males die as a result of a stress-induced suppression of the immune system. Ovulation occurs at this time and females rely on stored sperm from specialized crypts in the lower isthmus of the oviduct for successful fertilization. Here we report a high incidence of mixed paternity litters, which can be attributed to sperm from multiple males being stored in the isthmic crypts. Data from this study also suggest a possible second male siring advantage in controlled ex situ sperm competition mating trials, irrespective of the delay between the two males being given mating access to the female or of the mating time relative to ovulation. In determining paternity through DNA profiling, population genetic data were obtained that showed significant differences in the genetic heterozygosity between unrelated adults, half siblings and full siblings. We suggest that the isthmic crypts, in addition to storing viable sperm, are capable of releasing a mix of sperm that increases the likelihood of mixed paternity litters. This allows all mating males the opportunity to sire young, increases female reproductive fitness and overall maintains high levels of population genetic heterozygosity in the face of total male mortality annually.
When a high-velocity (i.e., typically > 0.1 MeV/amu) ion passes through a material it can change the properties of the material within a cylindrical zone centered on the essentially straight trajectory of the ion. The electronic bonding, phase, and density are among the properties modified in the zone, which is called a latent nuclear, or ion, track. Because the diameters of latent ion tracks are typically less than 20 nm, selective chemical etching is generally employed to improve the detection and assessment of the tracks. Historically, etched nuclear tracks have been used mainly for nuclear particle identification, geochronology, measurement of extremely low-dose radiation levels, and creation of membrane filters.
Very low threshold field emission from undoped microcrystalline diamond films grown by the hot filament chemical vapour deposition process (HFCVD) is reported. The effect of crystal size, methane concentration and the temperature has been studied. The microcrystalline diamond films grown using 3% methane (CH4) / hydrogen (H2) gas mixture ratio under varying deposition temperatures exhibit very low emission threshold fields. The threshold fields varied from 0.4 V/ [.proportional]m to 1 V/[.proportional]m for an emission current density of 1 [.proportional]A/cm2. A correlation between the emission characteristics and the material properties is presented. These films exhibit an emission site density of ∼ 104−105/cm2 at an applied field of 3 V/[.proportional]m.
We investigated electron field emission (FE) from heavily Si-doped AlN grown by metalorganic vapor phase epitaxy. We found that, as the Si-dopant density increases, the threshold electric field decreases, which indicates that electrons are supplied to the surface effectively as a result of Si doping. We show that heavily Si-doped AlN has a maximum FE current of 347 μA (the maximum current density of 11 mA/cm2), stable FE current (fluctuation: 3%), and a threshold electric field of 34 V/μm. We observed visible light emission (luminance: about 1200 cd/m2) from phosphors excited by the field-emitted electrons.
We analyze a non-traditional version of semiconductor field emission structure, based on silicon cones arrays and destined for application in low-voltage vacuum microelectronics devices. In proposed construction, the gate electrode is used as Shottky-barrier contact on silicon tips. Due to Shottkybarrier contact we have obtained depletion layer in tip body under the gate electrode. Therefore variation of the gate electric potential provides the emitter current modulation. Experimental structures were fabricated with about 28000 silicon cones per 1 mm2 by reactive ion etching through a silica mask. Using a quasi two-dimensional model, we have computed these emitter structures. The model takes into account non-uniformity of silicon cone cross-section. Here, we study the influence of emitter tips parameters on the structure performance. Initial results prove the possibility of cathode current electric control with the gate electrode potential. Additionally we have obtained some other electric parameters of the emitter with the Shottky-barrier contact. The results of numerical analysis and experimental study provide a guide for design of proposed field emitter structure.
Traditionally, organic light-emitting devices (OLEDs) are prepared with discrete layers for hole and electron transport. Different materials must be used for these layers because most materials will preferentially transport one charge carrier more efficiently than the other. In most cases, the emitter material serves a dual purpose as both the emitter and the hole or electron transporter. One of the major failure modes of OLEDs results from thermal instabilities of the insulating organic layers caused by joule heating during device operation. The problem is most pronounced for the hole transporting layer (HTL) material which are usually tertiary aromatic amines (i.e., TPD and NPD). This has been attributed to the relatively lower glass transition temperatures (Tg) and resulting inferior thermal stabilities compared to the other materials making up the device. Many researchers have produced HTL materials with higher Tgs based on tertiary aromatic amine oligomers and starburst compounds. Starburst or model dendritic materials offer the advantages of high thermal stabilities and multi-functionality.
Spectroscopic ellipsometry was used to evaluate the density and surface roughness of MgO films. The density of a film affects the dispersion of the film's refractive index, and the refractive index can be evaluated by spectroscopic ellipsometry. Among the various fitting models applied to all of the deposited films, the two-layered model gave the best results. For the two-layered model, we found that the thickness of the upper layer was strongly correlated with surface roughness. Thus, spectroscopic ellipsometry can be used to evaluate density and roughness.
For the development of new electron-emissive materials knowledge of the work function Φ and changes in Φ is of particular interest. Among the various methods, the ultra-high vacuum (UHV) compatible scanning Kelvin Probe has been proven to be a superior technique to measure work function changes due to e.g. UHV cleaning processes, chemical contamination, thermal processing etc. with high accuracy (<1meV).
The Kelvin Probe measures local work function differences between a conducting sample and a reference tip in a non-contact, truly non-invasive way over a wide temperature range. However, it is an inherently relative technique and does not provide an absolute work function if the work function of the tip (Φtip) is unknown.
Here, we present a novel approach to measure Φtip with the Kelvin Probe via the photoelectric effect, where a Gd foil is used as the photoelectron source. This method thus provides the true work function of the sample surface with an accuracy of approx. 50meV. We demonstrate the application of the technique by in situ work function measurements on evaporated layers of the low work function material LaB6 on a Re substrate and follow the changes in Φ of LaB6 due to the surface adsorption of residual gas molecules. Thus, the extended Kelvin Probe method provides an excellent tool to characterise and monitor the stability of low work function surfaces.