Cooperation and conflict – the British Army, the Natal government and the prosecution of Natal rebels during the Anglo-Boer War

The Natal Afrikaner1 rebels hardly feature in the historiography of the Anglo-Boer War of 1899–1902. The Times History of the War in South Africa dismisses their rebellion in one sentence,2 while the Natal Mercury of 25 April 1900 correctly points out that the number of rebels and the scale of the rebellion are rather insignificant when compared with that of the Cape Colony. In the latter, where in contrast to Natal, Afrikaners formed the bulk of the white population, the dynamics of the rebellion was very different. The large number of Afrikaners resident in the Cape Colony acted as a magnet for the Republican forces and as a result, large numbers of Afrikaners took up arms against Britain. From their side, the British authorities acted with a vengeance towards the Cape rebels, executing and imprisoning large numbers.3 Scientia Militaria: South African Journal of Military Studies Vol. 36 (2) 2008: pp. 77-9

A photoisomerizable muscarinic antagonist. Studies of binding and of conductance relaxations in frog heart

These experiments employ the photoisomerizable compound, 3,3'-bis- [alpha-(trimethylammonium)methyl]azobenzene (Bis-Q), to study the response to muscarinic agents in frog myocardium. In homogenates from the heart, trans-Bis-Q blocks the binding of [3H]-N-methylscopolamine to muscarinic receptors. In voltage-clamped atrial trabeculae, trans- Bis-Q blocks the agonist-induced potassium conductance. The equilibrium dose-response curve for carbachol is shifted to the right, suggesting competitive blockade. Both the biochemical and electrophysiological data yield a dissociation constant of 4-5 microM for trans-Bis-Q; the cis configuration is severalfold less potent as a muscarinic blocker. Voltage-clamped preparations were exposed simultaneously to carbachol and Bis-Q and were subjected to appropriately filtered flashes (less than 1 ms duration) from a xenon flashlamp. Trans leads to cis and cis leads to trans photoisomerizations cause small (less than 20%) increases and decreases, respectively, in the agonist-induced current. The relaxation follows an S-shaped time course, including an initial delay or period of zero slope. The entire waveform is described by [1 - exp(-kt)]n. At 23 degrees C, k is approximately 3 s-1 and n is 2. Neither k nor n is affected when: (a) [Bis-Q] is varied between 5 and 100 microM; (b) [carbachol] is varied between 1 and 50 microM; (c) carbachol is replaced by other agonists (muscarine, acetylcholine, or acetyl-beta-methylcholine); or (d) the voltage is varied between the normal resting potential and a depolarization of 80 mV. However, in the range of 13-30 degrees C, k increases with temperature; the Q10 is between 2 and 2.5. In the same range, n does not change significantly. Like other investigators, we conclude that the activation kinetics of the muscarinic K+ conductance are not determined by ligand-receptor binding, but rather by a subsequent sequence of two (or more) steps with a high activation energy

Canalizing Kauffman networks: non-ergodicity and its effect on their critical behavior

Boolean Networks have been used to study numerous phenomena, including gene regulation, neural networks, social interactions, and biological evolution. Here, we propose a general method for determining the critical behavior of Boolean systems built from arbitrary ensembles of Boolean functions. In particular, we solve the critical condition for systems of units operating according to canalizing functions and present strong numerical evidence that our approach correctly predicts the phase transition from order to chaos in such systems.Comment: to be published in PR

Understanding student early departure from a Master of Public Health programme in South Africa

Background. Student departure from university without completing a qualification is a major concern in higher education. Higher Education South Africa reported that in undergraduate studies, 35% of students depart after the first year and only 15% of students who enrol complete their degree within the minimum permissible time. At postgraduate level, the departure from Masters programmes in South Africa (SA) ranged from 30% to 67% in 2010. Early departure refers to students who leave an academic programme within the first semester of commencing their studies. At one SA university, there were a total of 109 first-time Master of Public Health (MPH) student registrations in 2013 and 2014. By the end of the first semester in the respective years, a total of 27 students actively deregistered from the programme and 11 students did not sit the first-semester examinations, representing an aggregate 35% rate of early departure. The factors associated with early departure at the University of KwaZulu-Natal are not well understood.Objective. To understand factors associated with early departure in the MPH programme at the University of KwaZulu-Natal.Method. A mixed-methods design was implemented. Students who departed within the first semester of commencing the MPH programme in 2013/2014 were followed up. Data were collected using self-administered questionnaires and in-depth interviews.Results. Failure to balance work and academic obligations with poor time management, stress and academic demands related to the programme, and insufficient academic progress were found to be associated with student early departure from the MPH programme.Conclusion. Student early departure from the MPH programme was influenced by multifaceted factors. Senior students can mentor new students as early as possible in their programme. The orientation block should include development activities such as time management, stress management and effective study skills to assist mature students to cope with the demands of part-time postgraduate studies

Prostaglandin-independent protection by furosemide from oliguric ischemic renal failure in conscious rats

Prostaglandin-independent protection by furosemide from oliguric ischemic renal failure in conscious rats. In 38 conscious rats divided into seven groups, acute unilateral ischemic renal failure was induced by 1 hour of complete occlusion of the left renal artery while the contralateral kidney remained intact. Renal excretory function of the left kidney was monitored up to 144 hours after ischemia and revealed a typical course of oliguric renal failure with oligoanuria persisting for more than 48 hours. Urinary osmolality and sodium concentration became plasma isotonic after release of renal artery occlusion and approximated control values on day 6 after ischemia. In nine rats, the i.v. infusion of furosemide before (6 µg/min/100g body wt) and after (12 µg/min/ 100g body wt) renal artery occlusion protected the ischemic kidney from oligoanuria with endogenous creatinine clearance of 0.42 ± 0.11 ml/min/g kidney wt 5 hours after ischemia. Tubular absorption of sodium and water was at least partially preserved 36 hours after ischemia when infusion of furosemide was stopped. The loop diuretic significantly (P < 0.01) increased total urinary prostaglandin (PG) E2 excretion before and after renal artery occlusion; and 5 hours after ischemia, PGE2 excretion from the ischemic kidney significantly exceeded that from the intact kidney (P < 0.05). Indomethacin (1 mg/100g body wt) administered in six animals markedly suppressed control PGE2 excretion (P < 0.05) as well as the furosemide-induced rise in urinary PG excretion before and after ischemia but did not modify the protective effect of the diuretic in this experimental model. Inhibition of PG synthesis, however, reduced urinary flow rate and sodium and potassium excretion of the contralateral intact kidney and almost completely prevented its compensatory rise in creatinine clearance. The results indicate that mechanisms other than the intrarenal prostaglandin system must be considered to mediate the protective effects of furosemide in acute ischemic renal failure.Protection par le furosemide, indépendante des prostaglandins, de l'insuffisance rénale oligurique et ischémique chez le rat éveillé. Trente huit rats éveillés, répartis en sept groupes, ont été mis en insuffisance rénale aiguë ischémique unilatérale par occlusion complète de l'artère rénale gauche pendant 1 heure alors que le rein controlatéral était intact. La fonction excrétoire du rein a été surveillée pendant 144 heures après l'ischémie et elle a subi l'évolution typique de l'insuffisance rénale oligurique avec persistance de l'oligo-anurie pendant plus de 48 heures. L'osmolalité urinaire et la concentration de sodium sont devenues égales à celles du plasma après la levée de l'occlusion artérielle rénale et se sont rapprochées des valeurs contrôles au sixième jour après l'ischémie. Chez neuf rats la perfusion de furosemide avant (6 µg/min/100g poids corporel) et après (12 µg/ min/100g poids corporel) l'occlusion de l'artère rénale a protégé le rein ischémique de l'oligo-anurie, avec des clearances de la créatinine de 0,42 ± 0,11 ml/min/g de rein 5 heures après l'ischémie. La réabsorption tubulaire de sodium et d'eau était au moins partiellement préservée 36 heures après l'ischémie quand la perfusion de furosemide était arrêtée. Ce diurétique augmente significativement (P < 0,01) l'excrétion urinaire de prostaglan-dines (PG) E2 avant et après l'occlusion de l'artère rénale; 5 heures après l'ischémie l'excrétion de PGE2 par le rein lésé est significativement supérieure à celle du rein intact (P < 0,05). L'indométhacine (1 mg/100g poids corporel) administrée à six animaux diminue considérablement l'excrétion basale de PGE2 (P < 0,05) de même que l'augmentation, dépendante du furosémide, de l'excrétion urinaire de PG avant et après l'ischémie, mais ne change pas l'effet protecteur du diurétique dans ce modèle expérimental. L'inhibition de la synthèse de PG, cependant, diminue le débit urinaire et l'excrétion de sodium et de potassium du rein intact et empêche presque complètement l'augmentation compensatrice de la clearance de la créatinine. Ces résultats indiquent que d'autres mécanismes que le système des prostaglandines intrarénales doivent être invoqués comme médiateurs des effets protecteurs du furosémide dans l'insuffisance rénale aiguë ischémique

Classification of minimal actions of a compact Kac algebra with amenable dual

We show the uniqueness of minimal actions of a compact Kac algebra with amenable dual on the AFD factor of type II$_1$. This particularly implies the uniqueness of minimal actions of a compact group. Our main tools are a Rohlin type theorem, the 2-cohomology vanishing theorem, and the Evans-Kishimoto type intertwining argument.Comment: 68 pages, Introduction rewritten; minor correction

Computing bisectors in a dynamic geometry environment

In this note, an approach combining dynamic geometry and automated deduction techniques is used to study the bisectors between points and curves. Usual teacher constructions for bisectors are discussed, showing that inherent limitations in dynamic geometry software impede their thorough study. We show that the interactive sketching of bisectors and an automatic treatment of the algebraic problem involved can give a reasonable knowledge about them. Since some cases are currently out of computational scope, despite the simplicity of the bisector problem, we sketch an alternative method for dealing with them

The pandemic push: can COVID-19 reinvent conferences to models rooted in sustainability, equitability and inclusion?

The COVID-19 pandemic necessitates a change in conference formats for 2020. This shift offers a unique opportunity to address long-standing inequities in access and issues of sustainability associated with traditional conference formats, through testing online platforms. However, moving online is not a panacea for all of these concerns, particularly those arising from uneven distribution of access to the Internet and other technology. With conferences and events being forced to move online, this is a critical juncture to examine how online formats can be used to best effect and to reduce the inequities of in-person meetings. In this article, we highlight that a thoughtful and equitable move to online formats could vastly strengthen the global socio-ecological research community and foster cohesive and effective collaborations, with ecology and society being the ultimate beneficiaries

Microseismicity Induced in the Opalinus Clay by a Gallery Excavation in the Mont Terri Underground Rock Laboratory

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