Pathogenesis of sudden death following water immersion (immersion syndrome)

Sympathetic activity under cold stress is investigated. Predominantly vagal cardio-depressive reflexes are discussed besides currently known mechanisms of sudden death after water immersion. Pronounced circulatory centralization in diving animals as well as following exposure in cold water indicates additional sympathetic activity. In cold water baths of 15 C, measurements indicate an increase in plasma catecholamine levels by more than 300 percent. This may lead to cardiac arrhythmias by the following mechanisms: cold water essentially induces sinus bradycardia; brady-and tachycardiarrhythmias may supervene as secondary complications; sinusbradycardia may be enhanced by sympathetic hypertonus. Furthermore, ectopic dysrhythmias are liable to be induced by the strictly sympathetic innervation of the ventricle. Myocardial ischemia following a rise in peripheral blood pressure constitutes another arrhythmogenic factor. Some of these reactions are enhanced by alcohol intoxication

Complexation of Secondary Amides to Chromium(III): the X-Ray Structure of a Molecule with Two Modes of Monodentate Organic Amide Co-ordination

The X-ray crystal structure of the dimer [Cr{H(chba-Et)}(py)_2]_(2)·2py [H_(4)(chba-Et)= 1,2-bis(3,5-dichloro-2-hydroxybenzamido) ethane, py = pyridine] establishes, for the first time, the existence of N-co-ordination of an organic amide to Cr^III, the N-atom and carbonyl O-atom of two separate amide groups being co-ordinated to each Cr^III centre [Cr–N 2.030(6) and Cr–O 1.976(5)Å]; the potentially tetra-anionic chelating ligand leads to a variety of co-ordination modes

Aneuploids of wheat and chromosomal localization of genes

Identification of useful major or minor genes is an important step in crop improvement programs. The chromosome location of such genes is critical for effective utilization and subsequent manipulation. Further, chromosomal localization will lead to the identification of genomic regions responsible for the expression of the trait of interest. DNA markers linked to these traits could be identified and used for marker-assisted breeding. Various cytogenetic stocks and techniques have been previously reported useful in localizing genes on wheat chromosomes. The objective of this paper is to assemble the most commonly used cytogenetic methods for the chromosomal localization of major genes in wheat including Chinese spring (CS) monosomics (Triticum aestivum, 2n=6x-1=41) and Langdon durum Dgenome disomic substitution lines (Triticum turgidum, 2n=4x-2+2=28). The paper reviewed and outlined the use and development of monomosic and substitution lines in a suitable genetic background for genetic analysis in wheat. The information may assist wheat researchers to locate and utilize newly identified genes in breeding programs.Key words: Aneuploids, Chinese spring, chromosome, cytogenetics, Langdon durum, monosomics, substitution lines

Online servicescape dimensions as predictors of website trust in the South African domestic airline industry

Increased costs, competition and a dynamic environment have led to South African domestic airlines relying more on their own websites as outlets for airline tickets. Customers’ e-commerce uptake with respect to buying airline tickets online has been slow, attributed mostly to a lack of website trust. A well-designed online servicescape has been identified as an important contributor to website trust by several authors, but not yet in this particular context or industry. This study investigates the extent to which three online servicescape dimensions predict website trust in the South African domestic airline industry. A quantitative and descriptive research design was followed, and 300 responses were collected through self-administered questionnaires from domestic airline passengers who had purchased an airline e-ticket from a website. A multiple regression analysis indicates that online financial security is the best predictor of website trust, followed by layout and functionality and aesthetic appeal. Consequently, it is recommended that South African domestic airlines that wish to cultivate website trust should focus primarily on enhancing the online financial security of their websites, followed by customising the layout and functionality of their websites, and lastly improving aesthetic appeal by increasing the entertainment value of their websites.Key words: aesthetic appeal, domestic airline industry, layout and functionality, online financial security, online servicescape, servicescape dimensions, website trus

Rural Finance and the Role of Development Banks: Recent Experience in South Africa

Exact date of working paper unknown.In the quest to expand access to financial services in rural areas the agricultural development bank is reexamined. Four issues that need to be addressed in the restructuring of these institutions are discussed, viz. the arguments for intervention, the rules that need to be applied in the context of the new approach to development finance, the management of the restructuring process and the politics of change. These issues or rules are applied to the restructuring process of retail development banks at the provincial level in South Africa. It is illustrated that for successful transformation political will and a shared vision are also necessities. The impact of appropriate transformation is quantitatively illustrated by the impact on financial self-sustainability in one such bank when these aspects have been adequately addressed in the transformation process and the failure in the remaining institutions when they are not

A multi‐scale study of the dominant catchment characteristics impacting low‐flow metrics

Low flows can impact water use and instream ecology. Therefore, reliable predictions of low-flow metrics are crucial. In this study, we assess which catchment characteristics (climate, topography, geology and landcover) can explain the spatial variability of low-flow metrics at two different scales: the regional scale and the small headwater catchment scale. For the regional-scale analysis, we calculated the mean 7-day annual minimum flow (qmin), the mean of the flow that is exceeded 95% of the year (q95), and the master recession constant (C) for 280 independent gauging stations across the Swiss Plateau and the Swiss Alps for the 2000–2018 period. We assessed the relation between 44 catchment characteristics and the three low-flow metrics based on correlation analysis and a random forest model. Low-flow magnitudes across the Swiss Plateau were positively correlated with the fraction of the area covered by sandstone bedrock or alluvium, and with the area that has a slope between 10° and 30°. Across the Swiss Alps, low-flow magnitudes were positively correlated with the fraction of area with slopes between 30° and 60°, and the area with glacial deposits and debris cover. There was good agreement between observations and predictions by the random forest regression model with the top 11 catchment characteristics for both regions: for 80% of the Swiss Plateau catchments and 60% of the Swiss Alpine catchments, we could predict the three low-flow metrics within an error of 30%. The residuals of the regression model, however, varied across short distances, suggesting that local catchment characteristics affect the variability of low-flow metrics. For the local-scale headwater catchments, we conducted 1-day snapshot field campaigns in 16 catchments during low-flow periods in 2015 and 2016. The measurements in these sub-catchments also showed that areas with sandstone bedrock and a good storage-to-river connectivity had above average low-flow magnitudes. Including knowledge on local catchment characteristics may help to improve regional low-flow predictions, however, not all local catchment characteristics were useful descriptors at larger scales