Topologies on groups and semigroups

Topological groups and semigroups form the basic building blocks of many different areas of mathematics. The aim of this work is to determine if a general cancellative semigroup can be given a left shift invariant topology. The theory behind a class of topologies that can be created on a given group or semigroup is discussed. The t-sequence proof of the Markov theorem is presented and this serves as a catalyst for further inquiry. The algebra of the Stone-Cech compactification of a discrete semigroup is utilized to prove the existence of certain ultrafilters, with which topologies can be constructed

An analysis of paramedic out-of-hospital endotracheal intubation success in Johannesburg, South Africa

Study objective: The aim of this study was to describe and analyse the success of endotracheal tube (ETT) placement when performed by paramedics in the out-of-hospital setting in Johannesburg, South Africa. Design: A prospective, observational study design with a consecutive convenience sample was used to analyse the prevalence of unrecognised mal-positioned ETTs by ALS paramedics. Setting: The ETT position was evaluated by the receiving medical practitioner in patients arriving at eight different urban, public and private, Johannesburg emergency departments (EDs) after being intubated by paramedics from multiple, both public and private – emergency medical services (EMS) agencies out-of-hospital. The study is set in a developing context where EMS systems vary considerably in terms of clinical governance, paramedic experience and qualification, and resources. Patients: All patients who arrived at Johannesburg EDs who had been intubated by paramedics out-of-hospital regardless of indication, aetiology or age, were included in the convenience sample. Methods: The main outcome measure was the unrecognized misplaced intubation rate which was recorded via routine methods by the receiving medical practitioner immediately upon arrival of the intubated patient at the ED. Findings were compared with international values. The use of endotracheal intubation confirmatory devices, both by paramedics and ED medical practitioners, was also reported. Main results: Of the 100 patients who were intubated out-of-hospital, 2 (2%; 95 CI 0.4% – 7.7%, p < 0.0001) arrived with unrecognised oesophageal ETT misplacements, and the ETT cuff was found to be in the pharynx, above the vocal cords in 1% of the sample. Thus, unrecognised mal-positioned intubations were detected in a total of 3 of 100 cases (3%; 95 CI 0.8% – 9.2%, p < 0.0001). Right main bronchus positioning occurred in 9 (9%) of cases. Paramedics reported the use of auscultation of the chest and stomach in 98% of the sample to confirm ETT placement, direct laryngoscopy in 22%, end-tidal carbon dioxide detection (ETCO2) in 19%, and pulse oximetry in 12% of patients. None of the misplaced ETTs had ETCO2 verification used out-of-hospital. ETT confirmation strategies by ED medical practitioners included auscultation of the chest and stomach in 97% of cases, direct laryngoscopy in 33%, and use of capnography to detect ETCO2 in only 4% of out-of-hospital intubated patients. Conclusions: This, the first known study to evaluate endotracheal intubation placement by EMS personnel in South Africa, found an overall 3% rate of misplaced ETTs (2 oesophageal and 1 hypopharyngeal), similar to several previous investigations, and much less than earlier studies. The findings of this study have important implications for South African EMS policy and practice. Based on the findings of this study, it seems reasonable to recommend that in a resource-limited, developing country where expensive ETCO2 is not readily available, the out-of-hospital ETT position should, at very least, be confirmed via auscultation, direct laryngoscopy and subjective clinical methods. Despite showing a statistically significant reduction in ETT misplacement rates when compared to international studies in similar settings, the results of this Johannesburg study are alarming and cause for concern, since any misplacement of an ETT in a critically ill or injured patient is calamitous with the potential for increased morbidity and mortality

Montpellier broom (Genista monspessulana) and Spanish broom (Spartium junceum) in South Africa: An assessment of invasiveness and options for management

AbstractThe legumes (Fabaceae) Genista monspessulana and Spartium junceum are major invaders in several other parts of the world, but not yet so in South Africa. We determine their current distributions in South Africa at different spatial scales, assess population structure (soil seed banks and size at reproduction) evaluate current management activities, and provide recommendations for control (including assessing the feasibility of nation-wide eradication). G. monspessulana occurs at nine localities in three quarter-degree cells, covering a total of 22.7ha. S. junceum is much more widespread, occurring in 33 quarter-degree cells and is frequently cultivated in private gardens. All naturalised or invasive populations are in disturbed areas, mostly along roadsides. Once established, G. monspessulana and S. junceum accumulate large, persistent soil-stored seed banks, ranging in size between 909 and 22,727 (median 1970)seeds/m2 and 0 and 21,364 (median 455)seeds/m2 for the two species respectively. Both species resprout vigorously after cutting and stump herbicide application (60% of G. monspessulana and 43% of S. junceum plants resprouted) which necessitates regular follow-ups. We estimate that over 10years, at a cost of about ZAR 81,000 (1 ZAR=0.114 US$ as on 6 October 2012), G. monspessulana could be extirpated from South Africa. S. junceum is far more widespread and coupled with low effectiveness of control, abundance of seeds and seed longevity, eradication is unfeasible. We recommend that control methods used for S. junceum be improved to prevent resprouting, and that areas are managed to limit the movement of seeds and avoid further spread and establishment. Further studies are required to understand why these two species have failed to replicate the invasiveness shown in other parts of the world

The history, basis and current status of the right or duty to extradite in public international and South African law

As the only internationally sanctioned means by which a fugitive offender may be returned from one state to another, extradition as public international law process has received surprisingly little attention in South African legal literature. The major trends in European extradition law are identified and a parallel is drawn with South African extradition from 1652 to the present. Extradition has a dual basis : treaty and non-treaty. Traditionally South Africa preferred treaty-based extradition, but with the adoption of the Extradition Act in 1962 this base was broadened. In a detailed analysis of section 3(2) of the Act it is shown that extradition is here in fact an act of comity. This has not always been recognised by the authorities who have confused section 3(2) comity with reciprocity. This may be ascribed to a basic misunderstanding of a reciprocal undertaking to extradite as an informally concluded treaty commitment. Most of South Africa's extradition treaties are inherited. State succession to bilateral treaties resulting from annexation and cession, devolution agreements, and dismemberment or secession is consequently traced through the various "successions in fact" occurring within South Africa from 1652-1961. Particularly within the South African courts, a misconception of the role of consent in succession has led to considerable confusion. An alternative approach to the succession process which emphasises the role of consent and gives due credit to succession as a separate international law phenomenon is proposed. Namibian succession to extradition treaties is addressed briefly. The termination of extradition treaties is examined and an assessment is made of the individual treaties appearing on the South African Treaty List culminating in a re-evaluation of states to which South Africa owes a duty to extradite and from which it may demand extradition as of right.Criminal and Procedural LawLL.D.

COVID-19 labour market shocks and their inequality implications for financial wellbeing

Using an online survey of Australian residents, we elicit the potential impacts of COVID-19 related labour market shocks on a validated measure of financial wellbeing. Experiencing a reduction in hours and earnings, entering into unemployment or having to file for unemployment benefits during the pandemic are strongly and significantly associated with decreases in financial wellbeing of around 29% or 18 points on the financial wellbeing scale of 0-100, despite various government measures to reduce such effects. Unconditional quantile regression analyses indicate that the negative COVID-19 labour market effects are felt the most by people in the lowest percentiles of the financial wellbeing distribution. Counterfactual distributional analyses and distribution regression indicate a shifting of the financial wellbeing distribution leftwards brought on by those suffering any of the above-mentioned labour market shocks, indicating potential dramatic increases in financial wellbeing disadvantage and inequality

The Psychonauts’ Benzodiazepines; Quantitative Structure-Activity Relationship (QSAR) Analysis and Docking Prediction of Their Biological Activity

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Designer benzodiazepines (DBZDs) represent a serious health concern and are increasingly re-ported in polydrug consumption-related fatalities. When new DBZDs are identified, very limited information is available on their pharmacodynamics. Here, computational models (e.g., quantita-tive structure-activity relationship/QSAR and Molecular Docking) were used to analyse DBZDs identified online by an automated web crawler (NPSfinder®) and to predict their possible activi-ty/affinity on the gamma-aminobutyric acid receptors (GABA-ARs). The computational software MOE was used to calculate 2D QSAR models, perform docking studies on crystallised GABA-A receptors (6HUO, 6HUP) and generate pharmacophore queries from the docking conformational results. 101 DBZDs were identified online by NPSfinder®. The validated QSAR model predicted high biological activity values for 41% of these DBDZs. These predictions were supported by the docking studies (good binding affinity) and the pharmacophore modelling confirmed the im-portance of the presence and location of hydrophobic and polar functions identified by QSAR. This study confirms once again the importance of web-based analysis in the assessment of drug scenarios (DBZDs), and how computational models could be used to acquire fast and reliable in-formation on biological activity for index novel DBZDs, as preliminary data for further investiga-tions.Peer reviewe

Risk of re-identification for shared clinical speech recordings

Large, curated datasets are required to leverage speech-based tools in healthcare. These are costly to produce, resulting in increased interest in data sharing. As speech can potentially identify speakers (i.e., voiceprints), sharing recordings raises privacy concerns. We examine the re-identification risk for speech recordings, without reference to demographic or metadata, using a state-of-the-art speaker recognition system. We demonstrate that the risk is inversely related to the number of comparisons an adversary must consider, i.e., the search space. Risk is high for a small search space but drops as the search space grows ($precision >0.85$ for $<1*10^{6}$ comparisons, $precision 3*10^{6}$ comparisons). Next, we show that the nature of a speech recording influences re-identification risk, with non-connected speech (e.g., vowel prolongation) being harder to identify. Our findings suggest that speaker recognition systems can be used to re-identify participants in specific circumstances, but in practice, the re-identification risk appears low.Comment: 24 pages, 6 figure

The relationship between vehicle yaw acceleration response and steering velocity for steering control

This paper proposes a novel concept for the modelling of a vehicle steering driver model for path following. The proposed steering driver reformulates and applies the Magic Formula, used for tyre lateral force vs. slip angle modelling as a function of vertical force, to the vehicle's yaw acceleration vs. steering velocity response as a function of vehicle speed. The path-following driver model was developed for use in gradient-based mathematical optimisation of vehicle suspension characteristics for handling. Successful application of gradient-based optimisation depends on the availability of good gradient information. This requires a robust driver model that can ensure completion of the required handling manoeuvre, even when the vehicle handling is poor. The steering driver is applied to a nonlinear full vehicle model of a sports utility vehicle, performing a severe double lane change manoeuvre. Simulation results show excellent correlation with test results. The proposed driver model is robust and well suited to gradient-based optimisation of vehicle handling.http://www.inderscience.com/sample.php?id=31hb201

Evaluation of the efficacy of d-penicillamine and trientine as copper chelators using an in vitro technique involving ovine red blood cells

An in vitro technique for haemolysing ovine red blood cells with copper sulphate was standardized to induce c 50% haemolysis with 0,5 mM CuSO₄ after incubation for 14 h at 38°C. This technique was then applied to test the efficacy of trientine and d-penicillamine in preventing haemolysis. Trientine concentrations of 0,5; 1,0 and 1,5 mM were found to be the most effective (P<0,05) in reducing copper-induced haemolysis. One and 1,5 mM concentrations of d-penicillamine were also effective (P< 0,05), but in this experiment a 0,5 mM concentration failed to protect the erythrocytes.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Palabora Mining Company.mn201