Scattering of a Long Cosmic String by a Rotating Black Hole

The scattering of a straight, infinitely long string by a rotating black hole is considered. We assume that a string is moving with velocity v and that initially the string is parallel to the axis of rotation of the black hole. We demonstrate that as a result of scattering, the string is displaced in the direction perpendicular to the velocity by an amount kappa(v,b), where b is the impact parameter. The late-time solution is represented by a kink and anti-kink, propagating in opposite directions at the speed of light, and leaving behind them the string in a new ``phase''. We present the results of the numerical study of the string scattering and their comparison with the weak-field approximation, valid where the impact parameter is large, b/M >> 1, and also with the scattering by a non-rotating black hole which was studied in earlier works.Comment: 27 pages, 14 figures, to be published in Classical and Quantum Gravit

Medical recipients of the Victoria cross during the Anglo-Boer war, 1899 -1902

No Abstrac

Die meting van die verband tussen geslag en konformiteit as groepdinamiese veranderlikes

The original publication is available at http://www.sajip.co.zaThe amount and kind of conformity induced by group pressure depend upon the nature of the situation. The nature of the group and the characteristics of the individual. In this particular study the experimental measurement of conformity developed by Asch and Crutchfield was repeated. Confirmation was found that sex operates as one of the determinants of conformity.Publishers' Versio

Global General Relativistic Magnetohydrodynamic Simulations of Accretion Tori

This paper presents an initial survey of the properties of accretion flows in the Kerr metric from three-dimensional, general relativistic magnetohydrodynamic simulations of accretion tori. We consider three fiducial models of tori around rotating, both prograde and retrograde, and nonrotating black holes; these three fiducial models are also contrasted with axisymmetric simulations and a pseudo-Newtonian simulation with equivalent initial conditions to delineate the limitations of these approximations.Comment: Submitted to ApJ. 30 pages, 21 figures. Animations and high-resolution version of figures available at http://www.astro.virginia.edu/~jd5

Thick domain walls around a black hole

We discuss the gravitationally interacting system of a thick domain wall and a black hole. We numerically solve the scalar field equation in the Schwarzschild spacetime and obtain a sequence of static axi-symmetric solutions representing thick domain walls. We find that, for the walls near the horizon, the Nambu--Goto approximation is no longer valid.Comment: 18 pages, 11 figures, one reference adde

Book Reviews

Principles of Cardiac Arrhythmias. 3rd ed. By Edward K. Chung. Pp. xiii 809. Illustrated. Baltimore: Williams &Wilkins. 1983.Ethical Issues in Reproductive Medicine. Ed. by M. Reidy. Pp. 176. Illustrated. RI9,60. Dublin: Gill & Macmillan. 1982.From Parasitic Infection to Parasitic Disease (Contribution to Microbiology and Immunology, vol. 7). Ed. by P. L. Gigase and E. A. C. van Marck. Pp. ix + 269. Illustrated. DM 216,-. Basle: S. Karger. 1983.Prolonged Arrest of Cancer (New Horizons in Oncology, vol. I). Ed. by B. A. Stoll. Pp. xiv + 454. Illustrated. £25,75. London: John Wiley. 1982.Pediatric Angiography. Ed. by P. Stanley. Pp. xv + 425. Illustrated. Baltimore: Williams & Wilkins. 1982.Thin-needle Aspiration Biopsy (Major Problems in Pathology, vol. 14). By W. J. Frable. Pp. X\'iii + 358. Illustrated. £42,25. Philadelphia: \'(t B. Saunders. 1983.Essentials of Pulmonary Medicine. By M. H. Williams. Pp. xi + 190. Illustrated. Philadelphia: W. B. Saunders. 1982.Noninvasive Assessment of the Cardiovascular System: Diagnostic Principles and Techniques. Ed. by E. B. Diethrich. Pp. xxiii + 319. Illustrated. £25,75. London: Wright PSG. 1982.Periodic Abstinence for Family Planning. Ed. by R. L. Kleinman. Pp. 60. Illustrated. £1,75 (in K only). London: IPPF Medical Publications. 1983

Provision of acute and elective general surgical care at a tertiary facility in the era of subspecialisation

Background. The need for an acute care and general surgical unit (ACGSU) to provide care for patients previously managed on an ad hoc basis by subspecialist units was recognised by the provincial government of the Western Cape Province, South Africa, the management of Groote Schuur Hospital (GSH) and the Department of Surgery.Objective. To describe the resulting ACGSU and its functioning.Methods. Data available from administrative records, patient files and operating room forms were collected in spreadsheet form for the period July 2013 - November 2016 inclusive.Results. The ACGSU comprised a medical care team of four consultants and four to five trainees. A total of 7 571 patients were seen during the study period, the majority (66.1%) referred from the GSH Emergency Centre. Skin and soft-tissue infections formed the major disease complex. A total of 3 144 operative records were available. The most common procedures were wound debridement and inguinal hernia repairs. Trainees acted as primary surgeon in most cases. Complications (Clavien-Dindo grades I - V) were noted in 25.0% of patients.Conclusions. The ACGSU provides patient management that would otherwise complicate care in the subspecialist surgical units. It serves as a training ground for registrars and stands as a model for other institutions. Further research into the effect on patient care is planned.

Effect of ospemifene on moderate or severe symptoms of vulvar and vaginal atrophy.

Objectives To determine whether assessment of all moderate-to-severe symptoms at baseline gives a more accurate evaluation of the treatment effect of ospemifene in vulvovaginal atrophy (VVA) than the most bothersome symptom (MBS) approach. Methods Data were pooled from two pivotal phase-III clinical trials evaluating the efficacy and safety of oral ospemifene 60 mg/day for the treatment of symptoms of VVA (n = 1463 subjects). Symptoms of vaginal dryness, dyspareunia, and vaginal and/or vulvar irritation/itching reported as moderate or severe at baseline were evaluated. Clinically relevant differences between ospemifene and placebo were analyzed using a four-point severity scoring system and presented as improvement, substantial improvement, or relief. Results Subjects in these studies reported statistically significant improvement, substantial improvement, and relief for vaginal dryness (p \u3c 0.00001), dyspareunia (p \u3c 0.001) and statistically significant improvement and relief for vaginal and/or vulvar irritation/itching (p \u3c 0.01) from baseline to week 12 with ospemifene compared with placebo. A similar trend was observed for women who reported substantial improvement of vaginal and/or vulvar irritation/itching. Conclusions For drug registration purposes, the use of the MBS model is appealing because of its simplicity and ease of scientific validation. However, the MBS model may underestimate the total magnitude of the clinical benefit of ospemifene treatment for symptomatic women suffering from VVA

Effect of ospemifene on moderate or severe symptoms of vulvar and vaginal atrophy.

Objectives To determine whether assessment of all moderate-to-severe symptoms at baseline gives a more accurate evaluation of the treatment effect of ospemifene in vulvovaginal atrophy (VVA) than the most bothersome symptom (MBS) approach. Methods Data were pooled from two pivotal phase-III clinical trials evaluating the efficacy and safety of oral ospemifene 60 mg/day for the treatment of symptoms of VVA (n = 1463 subjects). Symptoms of vaginal dryness, dyspareunia, and vaginal and/or vulvar irritation/itching reported as moderate or severe at baseline were evaluated. Clinically relevant differences between ospemifene and placebo were analyzed using a four-point severity scoring system and presented as improvement, substantial improvement, or relief. Results Subjects in these studies reported statistically significant improvement, substantial improvement, and relief for vaginal dryness (p \u3c 0.00001), dyspareunia (p \u3c 0.001) and statistically significant improvement and relief for vaginal and/or vulvar irritation/itching (p \u3c 0.01) from baseline to week 12 with ospemifene compared with placebo. A similar trend was observed for women who reported substantial improvement of vaginal and/or vulvar irritation/itching. Conclusions For drug registration purposes, the use of the MBS model is appealing because of its simplicity and ease of scientific validation. However, the MBS model may underestimate the total magnitude of the clinical benefit of ospemifene treatment for symptomatic women suffering from VVA

Entrepreneurial women’s cognitive ambidexterity : career and cultural influences

CITATION: De Villiers Scheepers, M. J., Boshoff, C. & Oostenbrink, M. 2017. Entrepreneurial women’s cognitive ambidexterity : career and cultural influences. South African Journal of Business Management, 48(2):21-33, doi:10.4102/sajbm.v48i4.40.The original publication is available at https://sajbm.orgThe purpose of this study was to examine how women’s career stage and Ubuntu (collectivist) values relate to their cognitive ambidexterity when pursuing entrepreneurial initiatives in multicultural South Africa. In this study individual cognitive ambidexterity was operationalised as using effectual and causal logic. More than three hundred businesswomen from diverse backgrounds were surveyed. The results revealed that career stage, self-efficacy and Ubuntu collectivism are important in women’s ambidexterity. Mature, efficacious women in their late career stage draw on their diverse networks and use effectual affordable loss, flexibility and causation when pursuing entrepreneurial initiatives. In contrast, younger, early-career women are more likely to use pre-commitment to ensure support from stakeholders. Women with Ubuntu values use their relationship skills to draw on resources from their networks and use ambidexterity (effectual and causal logic) in their entrepreneurial endeavours. The findings suggest that entrepreneurial women who develop their cognitive ambidexterity and draw on both effectual and causal approaches when initiating entrepreneurial initiatives are more likely to experience successful outcomes. These mental approaches can be developed by means of awareness, training and mentoring. This study extends the literature on women’s entrepreneurial decision-making in a culturally diverse society, demonstrating the influence of cultural values and career stage on effectual and causal logic.https://sajbm.org/index.php/sajbm/article/view/40Publisher's versio