Potential Neutrino Signals from Galactic Gamma-Ray Sources

The recent progress made in Galactic gamma-ray astronomy using the High Energy Stereoskopic System (H.E.S.S.) instrument provides for the first time a population of Galactic TeV gamma-rays, and hence potential neutrino sources, for which the neutrino flux can be estimated. Using the energy spectra and source morphologies measured by H.E.S.S., together with new parameterisations of pion production and decay in hadronic interactions, we estimate the signal and background rates expected for these sources in a first-generation water Cherenkov detector (ANTARES) and a next-generation neutrino telescope in the Mediterranean Sea, KM3NeT, with an instrumented volume of 1 km^3. We find that the brightest gamma-ray sources produce neutrino rates above 1 TeV, comparable to the background from atmospheric neutrinos. The expected event rates of the brightest sources in the ANTARES detector make a detection unlikely. However, for a 1 km^3 KM3NeT detector, event rates of a few neutrinos per year from these sources are expected, and the detection of individual sources seems possible. Although generally these estimates should be taken as flux upper limits, we discuss the conditions and type of gamma-ray sources for which the neutrino flux predictions can be considered robust.Comment: 20 pages, 4 figures; v2: ERROR in energy scale of KM3NeT effective neutrino area corrected which resulted in event rates being about a factor 3 too low; v3: grammatical changes and update of references after receiving proof

Preliminary trials with optical fiber dosimeters at TTF

Ionizing radiation leads to a degradation of the light transmitting properties of fiber optic cables. These effects usually place restrictions on where they can be used in a particle accelerator facility. These effects can also be used to our advantage, the losses from a particle beam create wavelength dependant increases of attenuation by absorption and scattering which can be measured using Optical Time Domain Reflectometry (OTDR). From these measurements a measure of the radiation dose received can be inferred

Influence of self-regulation within the South African accounting profession : perspectives from SME owners and professional accountants

Abstract: This study investigated the way professional accountants and SME owners experienced the self-regulation of professional accountants within South African SMEs. Furthermore, this study adopts an interpretivist approach, and dispels why traditional positivist accounting methods have been unable to reveal and investigate the complexities within the SME environment. The key findings of this study were that self-regulation posed significant risk to public interest and the liability of the professional accountant, and resulted in role confusion. A significant contribution of this research is the concept of ‘implied assurance’ that emerged due to the self-regulatory environment. This paper is the first to explore the views and make recommendations on accounting policy reform. It also adds to scarce literature on the structure and functioning of the accounting environment within developing economies and SMEs in South Africa

Anaesthetic management of a 10-month-old white rhinoceros (Ceratotherium simum) calf for emergency exploratory celiotomy

A 10-month-old, 580 kg, hand-reared white rhinoceros (Ceratotherium simum) calf was presented for emergency exploratory celiotomy. Anaesthesia was safely induced with three successive intravenous (IV) boluses of diazepam (10 mg) and ketamine (100 mg) until the trachea could be intubated. Anaesthesia was adequately maintained with isoflurane-inoxygen (mean end-tidal isoflurane concentration of 1.1% ± 0.2%) on a circle anaesthetic machine with carbon dioxide absorption and an intravenous infusion of ketamine and medetomidine at a mean rate of 0.02 mg/kg/min and 0.02 µg/kg/min, respectively. Mean values recorded during anaesthesia and surgery were heart rate (56.9 ± 11 beats/min), mean arterial blood pressure (6.16 kPa ± 1.75 kPa), end-tidal carbon dioxide concentration (6.23 kPa ± 0.30 kPa). Abdominal gas distension contributed to hypoventilation that resulted in hypercapnoea, confirmed by arterial blood gas analysis (PaCO2 14.69 kPa), which required controlled ventilation for correction. Blood volume was maintained with the intravenous infusion of a balanced electrolyte solution at 10 mL/kg/h and blood pressure supported with a continuous infusion of dobutamine and phenylephrine. Duration of anaesthesia was 3.5 h. It was concluded that anaesthesia was safely induced in a compromised white rhinoceros calf with a combination of diazepam and ketamine. A constant-rate infusion of medetomidine and ketamine allowed for a reduction in the dose of isoflurane required during maintenance of anaesthesia and improved intra-operative blood pressure management.http://www.jsava.co.zaam2013mn201

Hypocalcaemia in a six-month-old hand-reared female giraffe (Giraffa camelopardalis)

Radiological examination and surgical biopsy were required of a swelling in the cervical region in a healthy 200 kg, six-month-old hand-reared female giraffe (Giraffa camelopardalis). Induction was with intramuscular administration of medetomidine, butorphanol and ketamine and maintained with 1.5 per cent isoflurane-in-oxygen on a circle anaesthetic machine. Induction and maintenance were uneventful but recovery delayed and characterised by hindlimb weakness, opistotonus and torticollis of the head and neck. Atipamezole and naltrexone were administered to facilitate recovery but with minimal clinical improvement. Venous blood gas analysis indicated moderate metabolic acidosis, hypochloraemia, increased anion gap and marked hypocalcaemia (0.64 mmol/l). Intravenous administration of 60 ml calcium borogluconate resulted in a rapid improvement in muscle tone and the ability to stand. Hypocalcaemia was diagnosed in a juvenile giraffe after anaesthesia characterised by delayed recovery. Intravenous administration of calcium borogluconate resulted in rapid recovery of muscle strength and ambulance.http://vetrecordcasereports.bmj.comhb2016Companion Animal Clinical Studie

Field anaesthesia of the African elephant (Loxodonta africana)

Immobilisation and anaesthesia of elephants may be required for various reasons, such as the capture, transport and clinical examination of captive animals, e.g. at a zoological park, or for minor surgical procedures. General anaesthesia is required for wound treatment, i.e trunk lacerations and dental surgery, or population control, i.e. laparoscopic vasectomy.http://www.sajaa.co.za/index.php/sajaaam2014mn201

Role of a Transbilayer pH Gradient in the Membrane Fusion Activity of the Influenza Virus Hemagglutinin: Use of the R18 Assay to Monitor Membrane Merging

It had been suggested that influenza virus-mediated membrane fusion might be dependent on a pH gradient across a target membrane. We have designed experiments in which this issue could be addressed. Two populations of liposomes were prepared, both simulating the plasma membrane of target cells, but with the pH of the internal aqueous medium buffered either at pH 7.4 (physiological cytosol pH) or at pH 5.0 (endosomal pH at which influenza virus displays maximal fusion activity). By monitoring fusion using the R18 assay, we found that the internal pH of the target liposomes did not influence membrane merging as mediated by the influenza virus hemagglutinin, thus demonstrating that a transmembrane pH gradient is not required in this fusion process