Differential rotation and angular momentum

Differential rotation not only occurs in astrophysical plasmas like accretion disks, it is also measured in laboratory plasmas as manifested in the toroidal rotation of tokamak plasmas. A re-examination of the Lagrangian of the system shows that the inclusion of the angular momentum’s radial variation in the derivation of the equations of motion produces a force term that couples the angular velocity gradient with the angular momentum. This force term is a property of the angular velocity field, so that the results are valid wherever differential rotation is present

Numerical simulations of sunspots

The origin, structure and evolution of sunspots are investigated using a numerical model. The compressible MHD equations are solved with physical parameter values that approximate the top layer of the solar convection zone. A three dimensional (3D) numerical code is used to solve the set of equations in cylindrical geometry, with the numerical domain in the form of a wedge. The linear evolution of the 3D solution is studied by perturbing an axisymmetric solution in the azimuthal direction. Steady and oscillating linear modes are obtained

Suicides on Commuter Rail in California: Possible Patterns — A Case Study, Research Report 10-05

Suicides on rail systems constitute a significant social concern. Reports in local media, whether in newspapers, television, or radio, have brought awareness to this very sensitive and personal subject. This is also true for the San Francisco Bay Area. These events also cause severe trauma for the train operators and staff of the system as well as disruption and cost to society. The overall objective of this project was to conduct a pilot study to identify possible patterns in suicides associated with urban commuter rail systems in California. The Caltrain commuter rail system in the San Francisco Bay Area was used as the subject system for the pilot study. The primary intent of the data analysis was to determine whether suicides along the Caltrain tracks exhibited patterns. Pattern detection in this study was conducted primarily on the basis of time and location. Because the data were readily available, the gender factor was also included in the analysis, although this is not a factor that is connected to the rail system. It was concluded that the data did show some patterns for suicides with respect to time and location. Some of the patterns can be explained while the reasons for some are not immediately obvious. However, the patterns in the latter category did not indicate a particularly attractive location or possible source for suicides

Die bepaling van die ‘sentrum van hoofbelange’ by oorgrens insolvensies: Is die Parmalat-benadering voldoende om die behoeftes van moderne handel te bevredig?

Despite various viewpoints on the determination of the centre of main interest (COMI), the legal question in this investigation is whether, and to what extent, the approach in In re Eurofood IFSC Ltd (the Parmalat case) brings about an effective solution for the determination of the location of the COMI of individual companies, either unattached or as part of a group (in contrast with companies forming a so called economic unit). There exists a presumption that the COMI is situated there where the company’s registered office is. This is the physical factor in determining the COMI. There is also a mental or psychological factor. The COMI must correspond with the place which third parties (including foreigners) regard as the place where the debtor ordinarily manages its business and most prominent interests on a regular basis. If the registered office is situated at one place and the judgment of third parties with regard to the COMI is elsewhere, the presumption will not come into operation and the ordinary onus of proof will rest on the party concerned. If the subsidiary’s registered office and the opinion of third parties point to the same location (in order for the presumption to come into operation) the holding company should lead more substantial evidence so as to rebut the presumption. The presumption shall not be rebutted easily. An essential and delicate process of weighing up relevant factors should take place. The COMI must be identified with reference to criteria which are objectively foreseeable by all parties involved

A Theoretical Model to Measure Managerial and Leadership Competence of Business School Managers

A theoretical model to measure managerial competence was developed by evaluating two previous models with similar aims. In addition to the original eight management competencies, another eight competencies were identified and applied to determine the management competencies needed in the Fourth Industrial Revolution with its fast-changing business environment. The article narrows down eleven management competencies and develops measuring criteria for each; in total 42 criteria. The eleven business competencies are leading change, cultural intelligence, team building, conflict management, communication skills, a global leader mindset, emotional intelligence, career awareness, personal value system, and external and ethical influences. The model is a theoretical model and presents management competencies relevant to the modern business environment. The value of this study resides in a strong theoretical basis for postmodern business environmental skills that managers need to maintain completeness of their organizations as well as providing a sound point of departure for other researchers of managerial competence.&nbsp

In Search of an Alternative to Fire for Manipulating Bush Encroachment in the Arid Karoo Region of South Africa

Burning of natural rangeland in order to rejuvenate and increase palatability of grazing is a common practice in parts of South Africa. Concern about the long-term effects on biodiversity and the depletion of much-needed soil car-bon led to this investigation

The influence of marternal handicap on growth and reproduction in sheep

Ooie met enkel lammers het of voldoende vore ontvang om liggaamskondisie gedurende laktasie te handhaff (hoe peil) of die hoeveel-heid voer is verminder sodat n gemiddelde verlies van naastenby 20% in liggausmaan teweeggebring (lae peil). Die lammers het vrye toe-gang tot ru-en konsentraatvoere gehad. Na speen is die lammers gevoer om vinnige groei te bevorder. Die sogende lammers van ooie op die lae voedingspeil het nie merkbaar groter hoevoelhede ruvoer en konsentraat ingeneem as soortgelyke lammers van ooie op die hoe peil nie. Ondervoeding van die lakterende ooie het die ooi lammers by speen beduidend verlaag (P=0,001). Gedurende die naspeen tydperk is  hierdie agterstand in groei van die lammers geleidelik verminder, maar was nog merkbaar by geboorte van hul eerste lam.SUMMARYEwes with single lambs received either sufficient feed to maintain body condition during (high plane) or the qunatity of feed was reduced so as to result in an average loss of approximately 20% in bodymass (low plane). The suckling lambs had free access to roughage and concentrate feeds. After weaning the lambs were fed so as to promote rapid growth. The lambs suckled ny ewes on the low plane did not consume appreciably greater quantities of roughage and concentrate than similar lambs reared by ewes which were adequately fed. Under-feeding of the lactating ewes significantly reduced the bodymass of their ewe-lambs at weaning (P=0,001). The deficit in growth of the lambs was gradually reduced during the post-weaning period, but was still evident in their first parturition.

Impact of Recent Evidence on Use of Hormone Therapy in the South African Private Sector (2001-2005)

Background: The release of the results of the oestrogen plus progesterone therapy (EPT) arm of the Women\'s Health Initiative (WHI) in July 2002 started a worldwide process of reconsideration of the rationale behind hormone therapy (HT). This process was accelerated after the release of the results from the oestrogen-only (ET) arm of the same study. The results of the WHI reinforced the indications of HT to alleviate vasomotor symptoms and to prevent bone loss associated with early menopause, but refuted the possibility of cardioprotective effects and raised uncertainty around the risk of breast cancer for long-term users. In response, new guidelines and position statements were developed to aid healthcare practitioners and patients in various countries, including South Africa. The dissemination and penetration of all this information has been assessed in a number of countries, but the extent of its effect on the South African market is as yet unknown. Accordingly, the aim of this study was to assess the use of HT in the South African private sector from 2001 to 2005. Methods: Monthly HT sales data for January 2001 to October 2005 were obtained from IMS Health (SA). Three successive periods were compared: (1) January 2001 to June 2002 (discontinuation of the WHI oestrogen plus progestogen arm), (2) July 2002 to February 2004 (termination of the WHI oestrogen only arm) and (3) March 2004 to October 2005. Results: Overall, sales of HT fell 6.9% between periods 1 and 2 and 14.6% between periods 2 and 3. The total sales of ET predominated; they were more than double those of EPT. For ET, the sale of conjugated equine oestrogen (CEE) preparations exceeded those of non-CEE ET preparations, while for EPT preparations the reverse was true. The decline in ET sales was mostly accounted for by the fall in sales of CEE, by 9.8% and 20.6% for the two periods respectively. There was an increase in sales of both low-dose CEE and non-CEE, although the magnitude of increase in the case of the latter was much greater. Throughout the entire study period, CEE 0.625 mg tablets were found to account for the greatest sales volumes. Private sector sales represented 74.4% of total national HT sales over this period. Conclusion: The release of the WHI findings resulted in a modest decrease in HT sales in South Africa, although it was less dramatic than sales reported elsewhere. The change in prescribing cannot be attributed to any single factor. Factors such as publicity, adherence to new guidelines, and pharmaceutical marketing may all have contributed. Guidelines need to be updated as the results of new research continue to be published. There is also a need to periodically review prescribing trends, and to assess compliance with evidence-based guidelines, in order to improve the quality of medicines use. The majority of prescriptions for HT in South Africa are written by general practitioners, rather than by specialists. It is thus imperative that guidelines be appropriately framed for this market, as well as interpreted and applied. Keywords: hormone therapy (HT), South Africa, Women's Health Initiative South African Family Practice Vol. 50 (6) 2008: pp. 42-42

Using ceftazidime-avibactam for persistent carbapenem-resistant Serratia marcescens infection highlights antimicrobial stewardship challenges with new beta-lactam-inhibitor combination antibiotics

The newer beta-lactam-inhibitor combination (BLIC) antibiotics are available in South Africa (SA) for the treatment of carbapenem-resistant Enterobacterales infections. We describe the successful use of ceftazidime-avibactam (CA) for the treatment of a child with persistent carbapenem-resistant Serratia marcescens bacteraemia, and the challenges faced using this lifesaving antibiotic, including access to susceptibility testing, procurement process, cost and complexity of deciding when, how and for how long to use it. Furthermore, the burden of carbapenem resistance is increasing in SA, and inappropriate use of CA and other newer BLIC antibiotics, such as ceftolozane-tazobactam, will inevitably endanger their longevity. A careful balance must be struck between removing unnecessary obstacles and delays in initiating these antibiotics for life-threatening infections, and additional antimicrobial stewardship-guided interventions aimed at preserving their therapeutic use