Marine Cyanophytes from the Western Cape, South Africa: Chroococcales

Forty taxa of marine Chroococcales (Cyanophyceae) belonging to six families (Microcystaceae, Chroococcaceae, Chamaesiphonaceae, Dermocarpellaceae, Xenococcaceae and Hydrococcaceae) and 18 genera (Aphanocapsa, Aphanothece, Chamaecalyx, Chroococcidiopsis, Chroococcus, Cyanocystis, Cyanosarcina, Gloeocapsa, Hydrococcus, Hyella, Merismopedia, Microcrocis, Myxosarcina, Pleurocapsa, Stanieria, Stichosiphon, Synechococcus and Synechocystis) have been recorded for the Western Cape, South Africa, Twenty taxa are new records for South Africa; five at the generic level. (Cyanocystis, Synechococcus, Microcrocis, Synechocystis and Stichosiphon), fourteen at the specific level (Aphanothece stagnina, Aphanocapsa sesciacensis, Merismopedia affixa, M. litorale, Gloeocapsa crepidinium, G. cf, gelatinosa, Cyanosarcina cf. chroococcoides, Stanieria sphaerica, Chamaecalyx cf. fucicola, C. cf. suffultus, C cf. swirenkoi, Pleurocapsa crepidinium, P. cf minor and P. cf. minuta) and one at the varietal level (Chroococcus turgidus var. maximus). Morphological and size variability have been recorded and discussed

Open timelike curves violate Heisenberg's uncertainty principle

Toy models for quantum evolution in the presence of closed timelike curves (CTCs) have gained attention in the recent literature due to the strange effects they predict. The circuits that give rise to these effects appear quite abstract and contrived, as they require non-trivial interactions between the future and past which lead to infinitely recursive equations. We consider the special case in which there is no interaction inside the CTC, referred to as an open timelike curve (OTC), for which the only local effect is to increase the time elapsed by a clock carried by the system. Remarkably, circuits with access to OTCs are shown to violate Heisenberg's uncertainty principle, allowing perfect state discrimination and perfect cloning of coherent states. The model is extended to wave-packets and smoothly recovers standard quantum mechanics in an appropriate physical limit. The analogy with general relativistic time-dilation suggests that OTCs provide a novel alternative to existing proposals for the behaviour of quantum systems under gravity

Sense of humour and adolescents’ cognitive flexibility

Objective: There is a lack of research on humour among adolescents in South Africa. This article examines cognitive flexibility and humour. The objective was to investigate the roles of gender and language as possible moderating variables in the relationship between adolescents’ cognitive flexibility and sense of humour. Design: A correlational research design was used in which pupils were asked to complete the Multidimensional Sense of Humor Scale to assess their sense of humour. In order to determine the cognitive flexibility of the sample group, Martin and Rubin’s Cognitive Flexibility Scale was applied. Setting and subjects: The initial sample comprised 1 203 adolescents (Grade 11 and 12 pupils) randomly selected from the Eastern Cape, Gauteng and Mpumalanga. Of these, a final 392 adolescents qualified after eliminating criteria had been applied.Results: No significant correlations were found between the total group or for the two genders. Significant positive correlations were found between cognitive flexibility and two of the scores for humour (creating and expressing humour), as well as for the total score for Afrikaans-speaking participants. Significant negative correlations were found between cognitive flexibility and all five of the scores for humour for the Nguni language speakers. Conclusion: This study recommends that culturally sensitive measuring instruments should be developed.Keywords: sense of humour, cognitive flexibility, adolescents, psychological well-being, language, gende

Space-time qubits

We construct a qubit algebra from field creation and annihilation operators acting on a global vacuum state. Particles to be used as qubits are created from the vacuum by a near-deterministic single particle source. Our formulation makes the space-time dependence of the qubits explicit, preparing the way for quantum computation within a field framework. The method can be generalized to deal with interacting qubits whose wavepackets are not perfectly matched to each other. We give an example of how to calculate the Heisenberg evolution of a simple two-qubit circuit, taking expectation values in the field vacuum state.Comment: 8 pages, 7 figures, added references, added appendix, moved some text from introduction to conclusion, made minor corrections to text and figure

The Cochrane 2018 review on brief interventions in primary care for hazardous and harmful alcohol consumption: a distillation for clinicians and policy makers

Aims An updated Cochrane systematic review assessed effectiveness of screening and brief intervention to reduce hazardous or harmful alcohol consumption in general practice or emergency care settings. This paper summarises the implications of the review for clinicians. Methods Cochrane methods were followed. Reporting accords with PRISMA guidance. We searched multiple resources to September 2017, seeking randomised controlled trials of brief interventions to reduce hazardous or harmful alcohol consumption in people attending general practice, emergency care or other primary care settings for reasons other than alcohol treatment. Brief intervention was defined as a conversation comprising five or fewer sessions of brief advice or brief lifestyle counselling and a total duration of less than 60 min. Our primary outcome was alcohol consumption, measured as or convertible to grams per week. We conducted meta-analyses to assess change in consumption, and subgroup analyses to explore the impact of participant and intervention characteristics. Results We included 69 studies, of which 42 were added for this update. Most studies (88%) compared brief intervention to control. The primary meta-analysis included 34 studies and provided moderate-quality evidence that brief intervention reduced consumption compared to control after one year (mean difference −20 g/wk, 95% confidence interval −28 to −12). Subgroup analysis showed a similar effect for men and women. Conclusions Brief interventions can reduce harmful and hazardous alcohol consumption in men and women. Short, advice-based interventions may be as effective as extended, counselling-based interventions for patients with harmful levels of alcohol use who are presenting for the first time in a primary care setting

Human brucellosis in South Africa: Public health and diagnostic pitfalls

Human brucellosis in South Africa (SA) is under-diagnosed and under-reported. This is because many clinicians have little or no experience in managing affected patients, and in part because of the nonspecific and insidious nature of the disease. A case of human brucellosis caused by Brucella melitensis in a patient from the Western Cape Province of SA is described, and the resulting exposure of staff members at two medical microbiology laboratories, as well as the public health investigation that was conducted, are discussed. The objective of this article is to highlight the need for strengthening integration between public health, medical and veterinary services and exposing deficiencies in public health, veterinary and laboratory practices

Temporal and spatial history of Rift Valley fever in South Africa : 1950 to 2011

Several outbreaks of Rift Valley fever (RVF) have been documented in South Africa since it first occurred in the country in 1950. However, there is no comprehensive account of the timing, location and extent of all known outbreaks. As part of a study investigating the epidemiology of RVF in South Africa, a full history of outbreaks was compiled using references to the disease in South Africa from scientific literature, annual reports, disease reports and animal disease databases. The geographic location and temporal occurrence of each outbreak were recorded as accurately as allowed by the available records. The result was a better and more complete picture than has hitherto been available of the spatial and temporal distribution of RVF in South Africa for the period between 1950 and 2011. Several smaller outbreaks which had not been described previously in literature were documented. Extensive outbreaks occurred in the central interior of the country (Free State, Eastern Cape and Northern Cape provinces), interspersed with smaller outbreaks or long intervening periods of absence, whilst smaller outbreaks occurred in the eastern part of the country (KwaZulu-Natal, Mpumalanga and Gauteng).Scan this QR code with your smart phone or mobile device to read online.N.J.P. (University of Pretoria) performed the study and wrote the article. P.N.T. (University of Pretoria) was the academic study leader for the MSc degree of which this report formed part and assisted in study design, data analysis and writing of the article.http://www.ojvr.orgam2013ab2013ab201

Restoration of Vision with Ectopic Expression of Human Rod Opsin

SummaryMany retinal dystrophies result in photoreceptor loss, but the inner retinal neurons can survive, making them potentially amenable to emerging optogenetic therapies. Here, we show that ectopically expressed human rod opsin, driven by either a non-selective or ON-bipolar cell-specific promoter, can function outside native photoreceptors and restore visual function in a mouse model of advanced retinal degeneration. Electrophysiological recordings from retinal explants and the visual thalamus revealed changes in firing (increases and decreases) induced by simple light pulses, luminance increases, and naturalistic movies in treated mice. These responses could be elicited at light intensities within the physiological range and substantially below those required by other optogenetic strategies. Mice with rod opsin expression driven by the ON-bipolar specific promoter displayed behavioral responses to increases in luminance, flicker, coarse spatial patterns, and elements of a natural movie at levels of contrast and illuminance (≈50–100 lux) typical of natural indoor environments. These data reveal that virally mediated ectopic expression of human rod opsin can restore vision under natural viewing conditions and at moderate light intensities. Given the inherent advantages in employing a human protein, the simplicity of this intervention, and the quality of vision restored, we suggest that rod opsin merits consideration as an optogenetic actuator for treating patients with advanced retinal degeneration