STD care in the South African private health sector

Objectives. To establish the accessibility and quality of sexually transmitted disease (SID) care provided by private general practitioners (GPs) and workplace health services in South Africa.Design. Structured telephone interviews were conducted with a random national sample of 120 GPs and 244 occupational health nurses (OHNs) between May and July 1997. The interview schedules covered indicators of access (including utilisation) and processes (drug treatment, partner management, counselling and condom promotion) of STD care.Results. An estimated 5 million STD-related visits were made to private general practices in 1997. Reported treatment of STDs was assessed for effectiveness using well established syndromic case management guidelines. Only 28% of GPs reported effective treatment for urethral discharge. This dropped to 14% for genital ulcer and 4% for pelvic inflammatory disease. Fifty-five per cent of the OHNs interviewed indicated that their workplace clinics provided STD care. Nurses provided this care, with or without the support of doctors, in 87% of clinics. Reported urethral discharge and genital ulcer treatment regimens were assessed as effective in 34% and 14% of responses, respectively.Conclusions. The private sector is a major provider of STD care and is key to national efforts to achieve better STD control, thereby preventing the spread of HIV. However, the results of the research suggest that the poor quality of STD care may be underminlng attempts to control these epidemics in our society. Although a complex task, strategies need to be found to improve the quality of care provided within the private sector

Mental and perceptual feedback in the development of creative flow

Sketching is considered by artists and designers to be a vital tool in the creative process. However, research shows that externalisation during the creative process (i.e., sketching) is not necessary to create effectively. This study examines whether sketching may play a more important role in the subjective experience of creativity by facilitating the deeply focused, optimal state of consciousness termed ‘flow’ (being ‘in the zone’). The study additionally explored whether sketching affects flow by easing cognitive load or by providing a clearer sense of self-feedback. Participants carried out the creative mental synthesis task (combining sets of simple shapes into creative drawings), experimentally simulating the visual creative process. Ideas were generated either mentally before committing to a final drawing, or with external perceptual support through sketching, and cognitive load was varied by using either three- or five-shape sets. The sketching condition resulted in greater experience of flow and lower perceived task difficulty. However, cognitive load did not affect flow and there was no interaction between load and sketching conditions. These findings are the first to empirically demonstrate that sketching increases flow experience, and that this is not dependent on an associated reduction in overall working memory load

On visual pigment templates and the spectral shape of invertebrate rhodopsins and metarhodopsins

The absorbance spectra of visual pigments can be approximated with mathematical expressions using as single parameter the absorbance peak wavelength. A comparison of the formulae of Stavenga et al. in Vision Res 33:1011–1017 (1993) and Govardovskii et al. in Vis Neurosci 17:509–528 (2000) applied to a number of invertebrate rhodopsins reveals that both templates well describe the normalized α-band of rhodopsins with peak wavelength > 400 nm; the template spectra are virtually indistinguishable in an absorbance range of about three log units. The template formulae of Govardovskii et al. in Vis Neurosci 17:509–528 (2000) describe the rhodopsin spectra better for absorbances below 10−3. The template predicted spectra deviate in the ultraviolet wavelength range from each other as well as from measured spectra, preventing a definite conclusion about the spectral shape in the wavelength range <400 nm. The metarhodopsin spectra of blowfly and fruitfly R1-6 photoreceptors derived from measured data appear to be virtually identical. The established templates describe the spectral shape of fly metarhodopsin reasonably well. However, the best fitting template spectrum slightly deviates from the experimental spectra near the peak and in the long-wavelength tail. Improved formulae for fitting the fly metarhodopsin spectra are proposed

Adaptations in antagonist co-activation: Role in the repeated-bout effect

Eccentric exercise results in an adaptation which attenuates muscle damage from subsequent exercise—termed the “repeated-bout effect (RBE).” Purpose: Study examined antagonist co-activation and motor-unit recruitment strategy, assessed via dEMG, concomitant to the RBE. Methods: Nine participants performed 5 sub-maximal isometric trapezoid (ramp-up, hold, ramp-down) contractions at force levels corresponding to 50% and 80% of maximal isometric strength (MVC). Surface EMG signals of the biceps brachii were decomposed into individual motor-unit action potential trains. The relationship between mean firing rate (MFR) of each motor-unit and its recruitment threshold (RT) was examined using linear regression. Eccentric exercise was then performed until biceps brachii MVC had decreased by ~40%. Surface EMG of the biceps and triceps were collected during eccentric exercise. MVC, range-of-motion (ROM), and delayed onset muscle soreness (DOMS) were measured 24-hours, 72-hours, and 1-week following eccentric exercise. Three weeks later all procedures were repeated. Results: Changes in MVC (-32±14% vs -25±10%; p = 0.034), ROM (-11% vs 6%; p = 0.01), and DOMS (31.0±19mm vs 19±12mm; p = 0.015) were attenuated following the second bout of exercise. Triceps EMG was reduced (16.8±9.5% vs. 12.6±7.2%; p = 0.03) during the second bout of eccentric exercise. The slope (-0.60±0.13 vs -0.70±0.18; p = 0.029) and y-intercept (46.5±8.3 vs 53.3±8.8; p = 0.020) of the MFR vs. RT relationship was altered during contractions at 80% of MVC prior to the second bout of eccentric exercise. No changes were observed at 50% of MVC. Conclusion: A reduction in antagonist co-activation during the second bout of eccentric exercise suggests less total force was required to move an identical external load. This finding is supported by the increased negative slope coefficient and an increased y-intercept of the linear relationship between RT and MFR.Funded by University of Oklahoma Graduate College Robberson Grant.Ye

Metarhodopsin control by arrestin, light-filtering screening pigments, and visual pigment turnover in invertebrate microvillar photoreceptors

The visual pigments of most invertebrate photoreceptors have two thermostable photo-interconvertible states, the ground state rhodopsin and photo-activated metarhodopsin, which triggers the phototransduction cascade until it binds arrestin. The ratio of the two states in photoequilibrium is determined by their absorbance spectra and the effective spectral distribution of illumination. Calculations indicate that metarhodopsin levels in fly photoreceptors are maintained below ~35% in normal diurnal environments, due to the combination of a blue-green rhodopsin, an orange-absorbing metarhodopsin and red transparent screening pigments. Slow metarhodopsin degradation and rhodopsin regeneration processes further subserve visual pigment maintenance. In most insect eyes, where the majority of photoreceptors have green-absorbing rhodopsins and blue-absorbing metarhodopsins, natural illuminants are predicted to create metarhodopsin levels greater than 60% at high intensities. However, fast metarhodopsin decay and rhodopsin regeneration also play an important role in controlling metarhodopsin in green receptors, resulting in a high rhodopsin content at low light intensities and a reduced overall visual pigment content in bright light. A simple model for the visual pigment–arrestin cycle is used to illustrate the dependence of the visual pigment population states on light intensity, arrestin levels and pigment turnover