Engaging recreational fishers in management and conservation: global case studies.

Globally, the number of recreational fishers is sizeable and increasing in many countries. Associated with this trend is the potential for negative impacts on fish stocks through exploitation or management measures such as stocking and introduction of non-native fishes. Nevertheless, recreational fishers can be instrumental in successful fisheries conservation through active involvement in, or initiation of, conservation projects to reduce both direct and external stressors contributing to fishery declines. Understanding fishers' concerns for sustained access to the resource and developing methods for their meaningful participation can have positive impacts on conservation efforts. We examined a suite of case studies that demonstrate successful involvement of recreational fishers in conservation and management activities that span developed and developing countries, temperate and tropical regions, marine and freshwater systems, and open- and closed-access fisheries. To illustrate potential benefits and challenges of involving recreational fishers in fisheries management and conservation, we examined the socioeconomic and ecological contexts of each case study. We devised a conceptual framework for the engagement of recreational fishers that targets particular types of involvement (enforcement, advocacy, conservation, management design [type and location], research, and monitoring) on the basis of degree of stakeholder stewardship, scale of the fishery, and source of impacts (internal or external). These activities can be enhanced by incorporating local knowledge and traditions, taking advantage of leadership and regional networks, and creating collaborations among various stakeholder groups, scientists, and agencies to maximize the probability of recreational fisher involvement and project success.

Toward a quantitative theory of punishment.

In two experiments, pigeons' key pecking for food on concurrent variable-interval schedules was punished with electric shock according to concurrent variable-interval punishment schedules. With unequal frequencies of food but equal rates of punishment associated with the two keys and at several intensities of shock, the response and time allocation of all six pigeons overmatched the obtained relative frequency of food. The overmatching was predicted by a subtractive model of the interaction between punishment and positive reinforcement but not by two alternative models. Increases in the k and r(e) parameters of the generalized matching law could not account for the observed shifts in preference.

The law of effect and avoidance: a quantitative relationship between response rate and shock-frequency reduction.

Two experiments were conducted to investigate the quantitative relationship between response rate and reinforcement frequency in single and multiple variable-interval avoidance schedules. Responses cancelled delivery of shocks that were scheduled by variable-interval schedules. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and reinforcement frequency on single variable-interval avoidance schedules was accurately described by Herrnstein's (1970) equation for responding on single variable-interval schedules of positive reinforcement. On multiple variable-interval avoidance schedules with brief components, asymptotic relative response rate matched relative shock-frequency reduction. The results suggest that many interactions between response rates and shock-frequency reduction in avoidance can be understood within the framework of the generalized matching relation, as applied by Herrnstein (1970) to positive reinforcement.

Reinforcement and response rate interaction in multiple random-interval avoidance schedules.

Two experiments were conducted to investigate the interaction between response rate and reinforcement frequency in multiple random-interval avoidance schedules. Responses cancelled delivery of shocks that could be scheduled at different random intervals in each component. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and frequency of reinforcement was described by the same equations used by Herrnstein (1970) to describe responding with positive reinforcement.

Matching in concurrent variable-interval avoidance schedules.

After pretraining with multiple variable-interval avoidance schedules, two rats were exposed to a series of concurrent variable-interval avoidance schedules. Responses on two levers cancelled delivery of electric shocks arranged according to two independent variable-interval schedules. The ratio of responses and time spent on the two levers approximately matched the ratio of shocks avoided on each. Matching to the number of shocks received was not obtained. Concurrent variable-interval avoidance can therefore be added to the group of positive and negative reinforcement schedules that can be expressed in the quantitative framework of the matching law.

Concurrent performances: a baseline for the study of conditioned anxiety.

Three rats were trained to lever press on concurrent random interval 2-min random interval 2-min schedules of milk reinforcement. With a 5-sec changeover delay, relative response rate matched the relative reinforcement duration associated with each lever. A stimulus, during which unavoidable shocks occurred at random intervals, was superimposed on this concurrent baseline, and shifts in preference were found. However, data from this procedure were ambiguous, apparently confounded by shock-elicited response bursts. Termination of the shocks during the stimulus resulted in a rapid recovery of matching, which was preceded by a brief facilitation of responding on the less-preferred lever. The procedure was then changed to a conventional conditioned anxiety paradigm with a variable duration pre-shock stimulus. A marked shift in relative response rate towards the preferred lever was found in all three rats; that is, responding on the preferred lever was far less suppressed during the pre-shock stimulus than responding on the less-preferred lever.

Sputum induction for microbiological diagnosis of childhood pulmonary tuberculosis in a community setting.

SETTING: Sputum induction has increasingly enabled microbiological confirmation of pulmonary tuberculosis (PTB) in hospitalised children, but it has not been evaluated in a community setting. OBJECTIVE: To investigate the yield, feasibility and safety of sputum induction for the diagnosis of TB in children in a primary health care facility. DESIGN: A prospective study in a primary health care clinic in South Africa from April 2007 to June 2009. Consecutive children with clinically suspected PTB, with a household adult PTB contact or human immunodeficiency virus infected with respiratory symptoms were enrolled. History, clinical examination, tuberculin skin test and chest X-ray results were recorded. Two sequential induced sputum specimens were obtained for smear and culture. RESULTS: A total of 270 children were enrolled (median age 38 months); sputum induction was successful in 269 (99%); 65 (24%) children were clinically diagnosed, of whom 11 (16.9%) were microbiologically confirmed. An additional 18 children not clinically diagnosed had microbiological confirmation of PTB and were placed on TB treatment thereafter, increasing the diagnostic yield by 21.6%, from 65 to 83 cases. Sputum induction procedures were well tolerated; no major adverse events occurred. CONCLUSION: Sputum induction is feasible and safe in a community setting. Sputum induction was useful for making a microbiological diagnosis, increasing the number of children diagnosed and treated for PTB.

Prospects for monitoring freshwater ecosystems towards the 2010 targets.

Human activities have severely affected the condition of freshwater ecosystems worldwide. Physical alteration, habitat loss, water withdrawal, pollution, overexploitation and the introduction of non-native species all contribute to the decline in freshwater species. Today, freshwater species are, in general, at higher risk of extinction than those in forests, grasslands and coastal ecosystems. For North America alone, the projected extinction rate for freshwater fauna is five times greater than that for terrestrial fauna--a rate comparable to the species loss in tropical rainforest. Because many of these extinctions go unseen, the level of assessment and knowledge of the status and trends of freshwater species are still very poor, with species going extinct before they are even taxonomically classified. Increasing human population growth and achieving the sustainable development targets set forth in 2002 will place even higher demands on the already stressed freshwater ecosystems, unless an integrated approach to managing water for people and ecosystems is implemented by a broad constituency. To inform and implement policies that support an integrated approach to water management, as well as to measure progress in halting the rapid decline in freshwater species, basin-level indicators describing the condition and threats to freshwater ecosystems and species are required. This paper discusses the extent and quality of data available on the number and size of populations of freshwater species, as well as the change in the extent and condition of natural freshwater habitats. The paper presents indicators that can be applied at multiple scales, highlighting the usefulness of using remote sensing and geographical information systems technologies to fill some of the existing information gaps. Finally, the paper includes an analysis of major data gaps and information needs with respect to freshwater species to measure progress towards the 2010 biodiversity targets.

Simulium dermatitis in man--clinical and biological features in South Africa. A case report.

Simulium bite reaction is described; the lesions were present mainly on the lower legs as palpable purpura, which persisted for 2 weeks with marked oedema and considerable discomfort. Simuliids are tiny bloodsucking flies, popularly known as blackflies or buffalo flies, belonging to the dipterous family Simuliidae. They occur world-wide, breed in fast-flowing streams, and are a major animal pest. This is the first description of blackfly bites in man in the South African literature.

Myelography with a water-soluble contrast medium: a revision of technique and a review of results.

Experience with Dimer-X myelography in 3000 patients provides some indication of the scope of examination of the lumbar, thoracic and cervical segments of the spinal canal with a water-soluble contrast medium. Myelography with any contrast medium should only be applied for serious indications, and never as an outpatient procedure, for the patient requires careful after-treatment. However, the routine use of myelography may offer the best insurance against the disappointment and embarrassment of surgery by trial and error. The application of a careful, standardized technique makes it possible to obtain accurate information about the whole spinal canal and to avoid the danger of the false results to which examination with oily media are liable at all levels. The development of ever safer contrast media may help to limit the problem of spinal fibrosis, which is not a rare complication of myelography and spinal surgery.

Light-emitting diodes and half-cell electrodes in experimental recording of electroretinogram c-wave.

A method of electroretinogram c-wave recording in the rat was developed that uses a contact lens electrode connected through a saline bridge with a silver-silver chloride half-cell. A cluster of light-emitting diodes, regulated by an electronic light-emitting diode stimulator, was used as a light source. The method enables recordings of c-waves of 0.4-1.6 mV amplitude as well as other electroretinogram components in narrow limits of variation. The two main sources of response variability are voltage shunting and eyeball protrusion.

A further indigenous case of 'North American' blastomycosis from South Africa. Importance of skin lesions in early diagnosis.

A case of disseminated blastomycosis is reported. The patient presented with lung involvement, lupus vulgaris-like lesions, mainly of the face, and subcutaneous abscesses overlying areas of bone destruction. The diagnosis was confirmed by mycological microscopy and culture of skin material from involved areas. The importance of early diagnosis and the favourable response to treatment are emphasized.

An analysis of the appropriate use of the Caledon ambulance service in the Overberg. A short report.

The objective of this study was to determine the possible extent of the inappropriate use of the ambulances of the Caledon station of the Overberg Regional Services Council. The trip sheets of the ambulances for the period 1987-1990 were retrospectively analysed, and the appropriateness of calls prospectively determined over a 7-month period. The results showed that the vast majority of calls (68%) were of a non-emergency nature, and that only 34% of the trips warranted the use of a fully equipped emergency vehicle. Various cost-containment measures are suggested.

A cross-sectional study of the acquisition of grammatical morphemes in child speech.

Speech samples were taken from 21 children aged 16-40 months covering a wide range of mean utterance length. Presence or absence of 14 grammatical morphemes in linguistic and nonlinguistic obligatory contexts was scored. Order of acquisition of the morphemes was determined using two different criteria. The rank-orderings obtained correlated very highly with a previously determined order of acquisition for three children studied longitudinally. Age did not add to the predictiveness of mean length of utterance alone for grammatical development in terms of which morphemes were correctly used. The approximately invariant order of acquisition for the fourteen morphemes is discussed in terms of three possible determinants of this order. Frequency of use in parental speech showed no correlation with order of acquisition, but grammatical and semantic complexity both correlated highly with acquisition order.

Development of the use of word order in comprehension.

Thirty-three children aged between 19 and 38 months were presented with six reversible active and six reversible passive sentences and were required to act them out. For each child, mean length of utterance was calculated from a sample of spontaneous speech. Mean length of utterance was a more consistent predictor of performance than chronological age. Seven children with a mean length of utterance between 1.0 and 1.5 morphemes per utterance were unable to use the word order information in either type of sentence for comprehension. More developed children could comprehend reversible active sentences but not reversible passives. Children with a mean length of utterance between 3.0 and 3.5 morphemes per utterance systematically reversed the meaning of the reversible passives. The results are discussed in relation to previous studies of word order comprehension and studies of word order in production.

Constraints facing the female medical practitioner in private family practice in the Western Cape.

OBJECTIVES: To assess the existence and extent of employment-related problems facing female family practitioners in the context of a rapidly growing number of female doctors in South Africa. SUBJECTS AND METHODS: A descriptive survey was conducted using bilingual questionnaires. These were posted to all 280 female family practitioners in private practice in the Western Cape. RESULTS: Of the 280 questionnaires posted 169 were returned, but 45 of these were missampled. A response rate of 53% was obtained. The largest age category was 30-39 years. Of those not in solo practice, 68 (75%) were able to negotiate the terms of their working hours, 13 (19%) negotiated sick leave on commencing work, and only half had paid leave. Vacation leave was negotiated by 34 (50%), while only 6 (9%) discussed maternity leave with employers or colleagues. Of the 124 practices included in the survey, 6 (5%) had formal arrangements to cope with maternity leave. One hundred and seven respondents (86%) felt there was a need for maternity leave guidelines in the private sector in South Africa. Regarding practice-related problems, 33 female family practitioners (27%) reported some incidents of sexual harassment by patients. Despite these constraints, 88 respondents (71%) planned to continue working in this field. CONCLUSION: Definite obstacles exist in private family practice with regard to working conditions, in particular the lack of national regulations regarding maternity leave and the absence of legislation on pregnancy discrimination. This has important implications for the inclusion of female doctors in group practices and managed health care organisations--private primary health care of the present and future!

The development of passive health surveillance by a sentinel network of family practitioners in South Africa.

OBJECTIVE: For the South African Sentinel Practitioner Research Network (SASPREN), a volunteer network of family practitioners in South Africa, to develop a health surveillance system through the surveillance of important health events. MOTIVATION: The incidence of important preventable diseases and the burden of disease are not reliably known in South Africa, both in the public and private sector. Incidence rates determined at primary care level could help with planning and delivery of appropriate health services and monitoring of the impact of intervention programmes. METHODS: Altogether 183 sentinel practitioners were recruited in nine provinces, from 2,478 doctors invited to participate. Of these 120 were active in reporting all their new cases of 13 selected health events to the study centre on mailed postcards. After data-capturing, incidence rates were calculated for defined periods. Feedback was given to the sentinels through a newsletter and personalised reports. RESULTS: A network of sentinel family practitioners has been established in South Africa, and can provide incidence rates for both diseases and interventions through a simple and cheap surveillance system. The calculated rates demonstrated periodic trends for certain events, as well as inter-provincial, -gender and -population group differences. CONCLUSIONS: As the validity of the dataset and its generalisation to the whole population is uncertain, its usefulness as point estimates of incidence rates is unknown. This information serves as an important pointer for further research. The trends of these rates may provide a valuable tool for monitoring the impact of public health policies.