Forced patterns near a Turing-Hopf bifurcation

We study time-periodic forcing of spatially-extended patterns near a Turing-Hopf bifurcation point. A symmetry-based normal form analysis yields several predictions, including that (i) weak forcing near the intrinsic Hopf frequency enhances or suppresses the Turing amplitude by an amount that scales quadratically with the forcing strength, and (ii) the strongest effect is seen for forcing that is detuned from the Hopf frequency. To apply our results to specific models, we perform a perturbation analysis on general two-component reaction-diffusion systems, which reveals whether the forcing suppresses or enhances the spatial pattern. For the suppressing case, our results explain features of previous experiments on the CDIMA chemical reaction. However, we also find examples of the enhancing case, which has not yet been observed in experiment. Numerical simulations verify the predicted dependence on the forcing parameters.Comment: 4 pages, 4 figure

Connexin36 knockout mice display increased sensitivity to pentylenetetrazol-induced seizure-like behaviors

Large-scale synchronous firing of neurons during seizures is modulated by electrotonic coupling between neurons via gap junctions. To explore roles for connexin36 (Cx36) gap junctions in seizures, we examined the seizure threshold of connexin36 knockout (Cx36KO) mice using a pentylenetetrazol (PTZ) model

The snacking habits of white preschool ·children

Three-day estimated dietary records were kept for 194 white 3- and 4-year-old children to deterMine and evaluate the extent, nature and quality of their snacking. All but 1 child ate between meals, with morning and afternoon snacking being favoured in terms of frequency and quantity. Soft drinks were .consumed most frequently, followed by fresh fruits and fruit juices, sweets and chocolates, milk and sugar. Between-meal eating contributed more than one-third of the average day's energy and approximately one-quarter of most vitamins and minerals to the children's diets. Foods eaten between meals were, however, significantly less nutrient-dense than mealtime foods. Non-basic foods supplied more energy to the diet than _ any of the five basic food groups, but minimal quantities of micronutrients. Sugar consumption, mostly in the form of sugary foods and drinks, was high, but was not consumed exclusively between meals. Such children should be encouraged to make more use of basic commodities, particularly when snacking

Phylogeny of Holocacista capensis (Lepidoptera: Heliozelidae) from Vineyards and Natural Forests in South Africa Inferred from Mitochondrial and Nuclear Genes

In South Africa, the family Heliozelidae in the order Lepidoptera is restricted to four known species.  The grapevine leaf miner, Holocacista capensis, feeds between the epidermal layers of a grapevine leaf,predominantly along the leaf margin. A final instar larva will descend from the blotch mine/gallery to attach its cocoon casing (constructed from the epidermal layers of the mined gallery) to any object belowthe infested leaf. Five monophyletic clades and a polyphyletic group have been identified within the Heliozelidae, using a mitochondrially encoded gene cytochrome c oxidase I (COI) and a nuclear gene,histone 3 (H3). An exploratory study of the genetic diversity within H. capensis populations was conducted using these genes. The phylogenetic analyses of COI indicate that H. capensis that are currently beingcollected from South Africa fall within three clades/haplotypes, of which one is well supported and contains only one species from Gauteng, and one has three specimens from two different areas in the Western Capeprovince, while 80% belong to haplotype 1 (H1). The current study can be used as a starting point for future DNA-based studies aimed at gaining insight into possible patterns of diversity in H. capensis toconfirm switching from native to commercial grapevine hosts. However, more samples need to be collected from different areas in South Africa

Incentives and South Africa's automotive industry performance : a system dynamics approach

Investment in robotic automotive manufacturing and inherent electronics has played a pivotal role in the growth and competitiveness of the South African automotive industry. Government's offering of incentives was intended to lessen the cost of local industry’s expensive, but necessary investment. Despite the growth, industry trade balance has been declining systematically. To explain the apparent contradiction in industry performance, a model of South Africa’s automotive incentives – including the Productive Asset Allowance (PAA) and the Import-Export Complementation (IEC) – was developed. Model simulations reveal that, while the IEC had a significant effect on the industry trade balance, the role of the PAA in this regard is trivial. Ultimately, the study reveals that combining strictly investment incentives with other ‘non-investment’ incentives can have unintended consequences for the local automotive industry.http://www.saiee.org.za/DirectoryDisplay/DirectoryCMSPages.aspx?name=Publications#id=1588&dirname=ARJ&dirid=337am2016Graduate School of Technology Management (GSTM

Assessment of skeletal changes after post-mortem exposure to fire as an indicator of decomposition stage

Forensic anthropologists are tasked with interpreting the sequence of events from death to the discovery of a body. Burned bone often evokes questions as to the timing of burning events. The purpose of this study was to assess the progression of thermal damage on bones with advancement in decomposition. Twenty-five pigs in various stages of decomposition (fresh, early, advanced, early and late skeletonisation) were exposed to fire for 30 min. The scored heat-related features on bone included colour change (unaltered, charred, calcined), brown and heat borders, heat lines, delineation, greasy bone, joint shielding, predictable and minimal cracking, delamination and heat-induced fractures. Colour changes were scored according to a ranked percentage scale (0–3) and the remaining traits as absent or present (0/1). Kappa statistics was used to evaluate intra- and inter-observer error. Transition analysis was used to formulate probability mass functions [P(X = jji)] to predict decomposition stage from the scored features of thermal destruction. Nine traits displayed potential to predict decomposition stage from burned remains. An increase in calcined and charred bone occurred synchronously with advancement of decomposition with subsequent decrease in unaltered surfaces. Greasy bone appeared more often in the early/fresh stages (fleshed bone). Heat borders, heat lines, delineation, joint shielding, predictable and minimal cracking are associated with advanced decomposition, when bone remains wet but lacks extensive soft tissue protection. Brown burn/borders, delamination and other heat-induced fractures are associated with early and late skeletonisation, showing that organic composition of bone and percentage of flesh present affect the manner in which it burns. No statistically significant difference was noted among observers for the majority of the traits, indicating that they can be scored reliably. Based on the data analysis, the pattern of heat-induced changes may assist in estimating decomposition stage from unknown, burned remains.National Research Foundation (NRF) of South Africa.http://www.elsevier.com/locate/forsciinthb201

The Lingering Environmental Impact of Repressive Governance: The Environmental Legacy of the Apartheid Era for the New South Africa

This article aims to explore the historical link between contemporary environmental problems and the environmental, economic and political policies of the apartheid government. The analysis draws on an examination of the detrimental environmental impacts of the apartheid era and how international isolation impacted on governmental environmental management in the country, before turning attention to the way in which the ANC government has managed the South African natural and human environments in the period after 1994. The article shows that despite many important new developments since 1994, that there are high levels of continuity between the environmental management practices of the old and the new regimes. This state of affairs negatively impacts on the ability of the ANC government to provide every South African citizen with the clean and safe environment guaranteed to all within the 1996 Bill of Rights.This article also appeared unchanged as a chapter in the following edited collection: Jan Oosthoek and Barry K. Gills (eds), _The Globalization of Environmental Crisis_ (Abingdon: Routledge, 2008), pp. 109-120

Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest $A = 9$ isospin quartet. The conclusions relied upon the choice of the excitation energy for the second $T = 3/2$ state in $^9$B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the $^9{\rm Be}(^3{\rm He},t)$ reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for $A = 9$ nuclei

Doping in sport: Attitudes, beliefs and knowledge of competitive high school athletes in Gauteng Province

Objective. To determine the attitudes, beliefs and knowledge of talented young athletes residing in Gauteng regarding prohibited performance-enhancing drugs (PEDs) and anti-doping rules and regulations.Methods. This was a survey study using a quantitative research approach. South African TuksSport academy athletes at the High Performance Centre, University of Pretoria, and competitive high-school athletes at four private high schools in Gauteng completed the survey. A selfdetermined, structured questionnaire was used to establish the attitudes, beliefs and knowledge of the athletes.Results. A total of 346 (208 males, 138 females) athletes, mean (standard deviation) age 16.9 (1.4) years participated in the survey. According to this survey, 3.9% of the athletes in this survey admitted to using a prohibited PED and more than 14.0% of the athletes said they would consider using a prohibited PED if they knew they would not get caught. Ambition (46.0%) and emotional pressure (22.5%) were the primary reasons why the athletes would consider using prohibited PEDs. Even though coaches appeared to be one of the main sources of information (on PEDs and anti-doping rules), only 42.1% of the athletes felt that they were well informed.Conclusion. Controlling doping by means of testing is important. However, it may be necessary to put more emphasis on changing attitudes towards doping and implementing additional educational programmes

Multimorbidity, control and treatment of noncommunicable diseases among primary healthcare attenders in the Western Cape, South Africa

Background. South Africa (SA) is facing a heavy burden of non-communicable diseases (NCDs). Few studies address multimorbidity, control and treatment of NCDs in patients attending primary healthcare (PHC) clinics. Objectives. To describe multimorbidity, related risk factors, disease severity and treatment status of patients with four important NCDs attending public sector PHC clinics in two districts in SA. Methods. A cross-sectional sample of patients completed baseline data collection for a randomised controlled trial of a health systems intervention. The study population comprised adults attending PHC clinics in the Eden and Overberg districts of the Western Cape in 2011. Four subgroups of patients were identified: hypertension, diabetes, chronic respiratory disease and depression. A total of 4 393 participants enrolled from 38 clinics completed a baseline structured questionnaire and had measurements taken. Prescription data were recorded. Results. Of participants with hypertension, diabetes, respiratory disease and depression, 80%, 92%, 88% and 80%, respectively, had at least one of the other three conditions. There were low levels of control and treatment: 59% of participants with hypertension had a blood pressure ≥140/90 mmHg, the mean haemoglobin A1c (HbA1c) value in participants with diabetes was 9%, 12% of participants in the depression group were prescribed an antidepressant at a therapeutic dose, and 48% of respiratory participants were prescribed a b2-agonist and 34% an inhaled corticosteroid. Conclusion. Considerable multimorbidity and unmet treatment needs exist among patients with NCDs attending public sector PHC clinics. Improved strategies are required for diagnosing and managing NCDs in this sector