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Het hanteren van muizen aan de staart wekt bij de dieren een stressrespons op. Deze techniek is echter in de meeste laboratoria nog steeds gebruikelijk. Reden hiervoor ligt grotendeels bij het praktische aspect van het gebruik van deze techniek. Of hanteren met behulp van een buis, dat minder stress veroorzaakt bij de muizen, praktisch toepasbaar is, is de kern van dit onderzoek.

Bacillus spp. have long been used as biocontrol agents because of their efficient broad-spectrum antimicrobial activity. We identified a novel strain of Bacillus atrophaeus, named JZB120050, from soil. B. atrophaeus JZB120050 had a strong inhibitory effect against Botrytis cinerea and many other phytopathogens. Gas chromatography-mass spectrometry showed that B. atrophaeus JZB120050 produced many secondary metabolites, such as alkanes, alkenes and acids; some of which were related to pathogen inhibition. Enzyme activity analysis showed that B. atrophaeus JZB120050 secreted cell-wall-degrading enzymes, including chitinase, glucanase and protease, which degraded fungal cell walls. Both the novel glucanase gene bglu and chitinase gene chit1 were cloned and heterologously expressed in Escherichia coli and the products showed strong enzyme activity. In addition, B. atrophaeus JZB120050 secreted siderophores and formed a significant biofilm. Future studies should focus on these antimicrobial factors to facilitate widespread application in the field of agricultural biocontrol.

Spermatogenesis and sperm ultrastructure were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) in the longidorid Xiphinema theresiae. All germ cell stages, except spermatogonia, are present in the testes of young adult males. The nonflagellated, slightly elongated sperm displays little intraspecific variation and, although never polarized into a head and tail region, has a remarkably precise form, with a high degree of internal organization. Incipient fingerlike pseudopodia appear in the young spermatid and increase to such an extent that the adult sperm has a conspicuous "woolly" appearance. Microfilament bundles encircle the perinuclear mitochondria in the spermatid, and seem to be closely associated with the evaginated plasma membrane, especially in the spermatozoon. A large nucleus with nuclear envelope is prominent in the spermatocyte, but the envelope is absent in the young spermatid. Mitochondria are present in all germ cell stages and undergo certain morphological changes (e.g., in size and number, presence or absence of cristae), as well as changes in intracellular movements during spermatogenesis. Membranous organelles are prominent in the spermatocyte, but disappear in the older spermatid. Annulate lamellae and a residual body (i.e., cytophore) are conspicuous in the spermatocyte and spermatid, respectively; the spermatozoon clearly lacks a refringent body (i.e., acrosome).

A study was undertaken to determine the feasibility of introducing a computerised electrocardiographic analysis and interpretive system as a service to a teaching and referral hospital. Available computer equipment and programmes are considered. The accuracy and quality of the analysis and interpretation of the electrocardiographic contours are basically dependent on such factors as pattern recognition, the criteria adopted for determining abnormalities, the relative values placed on scalar and orthogonal leads and the role of review by the physician. It is concluded that such systems are at a stage where they can feasibly be introduced and should be of advantage in freeing the physician from ,routine measuring and screening of electrocardiograms, thus saving many hours of professional and academic time. Furthermore, such systems can contribute greatly as an educational tool and increase the general knowledge of electrocardiography. Systems for storage and retrieval are also being developed and becoming available. The whole field is a developing one and continuous updating of programmes by the addition of more data, particularly for children, and the introduction of electrocardiographic comparison programmes need to be expedited.S. Afr. Med. J., 48, 1141 (1974).

Generic skills are those overt and covert behaviors which are fundamental to the performance of many tasks and subtasks carried out in a wide range of occupations and which are basic to both specialized applications and job specific skills. They consist of academic, reasoning, interpersonal and manipulation skills. The generic approach is important to occupational training because it is prescriptive, integrated with basic education, and economical. Generic skills are based upon the premise that every occupation requires a worker to function in relation to data, people, and things, in varying degrees. It is the relationship to data which is the focus of this study. Data has been gathered on 27 occupations in four geographical areas. After its analysis, specifications for the development of data skills training packages have been completed. The training packages consist of (1) a discrete curriculum package for each unit, with objectives, tests, and references, (2) an instructor's manual, (3) an answer book, and (4) individualized learning packages where needed. The packages are expected to be ready for pilot testing in January 1974. (Author/MS)

Cut-off low (COL) weather systems that are associated with rainfall over the Eastern Cape are considered in this study. COLs are objectively identified and tracked over a 31-year period. Daily rainfall data of 22 evenly distributed stations over the Eastern Cape are utilized. Only COLs with a minimum spatial distribution, defined as more than a third of the rainfall stations that need to report rainfall on at least 1 day of a COL event, are considered for analysis of rainfall attributes. These attributes include the occurrence of COL rain days of different magnitudes, the distribution of the depth and temperature of the COL centres for the rain days of different magnitudes, the associated spatial distribution of rainfall as well as the associated atmospheric circulation. The frequency of COLs over the Eastern Cape has a winter maximum and a summer minimum. COL rain days of small, medium and large magnitudes occur most frequently during the winter, while small- and medium-magnitude COL rain days experience peaks in autumn and spring, respectively. The low-level flow, and in particular the position of the low/trough, seems to be the determinant factor in the occurrence, magnitude and spatial extent of COL-induced rainfall.

Austral summer rainfall over the period 1991/1992 to 2010/2011 was dynamically downscaled by the weather research and forecasting (WRF) model at 9 km resolution for South Africa. Lateral boundary conditions for WRF were provided from the European Centre for medium-range weather (ECMWF) reanalysis (ERA) interim data. The model biases for the rainfall were evaluated over the South Africa as a whole and its nine provinces separately by employing three different convective parameterization schemes, namely the (1) Kain–Fritsch (KF), (2) Betts–Miller–Janjic (BMJ) and (3) Grell–Devenyi ensemble (GDE) schemes. All three schemes have generated positive rainfall biases over South Africa, with the KF scheme producing the largest biases and mean absolute errors. Only the BMJ scheme could reproduce the intensity of rainfall anomalies, and also exhibited the highest correlation with observed interannual summer rainfall variability. In the KF scheme, a significantly high amount of moisture was transported from the tropics into South Africa. The vertical thermodynamic profiles show that the KF scheme has caused low level moisture convergence, due to the highly unstable atmosphere, and hence contributed to the widespread positive biases of rainfall. The negative bias in moisture, along with a stable atmosphere and negative biases of vertical velocity simulated by the GDE scheme resulted in negative rainfall biases, especially over the Limpopo Province. In terms of rain rate, the KF scheme generated the lowest number of low rain rates and the maximum number of moderate to high rain rates associated with more convective unstable environment. KF and GDE schemes overestimated the convective rain and underestimated the stratiform rain. However, the simulated convective and stratiform rain with BMJ scheme is in more agreement with the observations. This study also documents the performance of regional model in downscaling the large scale climate mode such as El Nino Southern Oscillation (ENSO) and subtropical dipole modes. The correlations between the simulated area averaged rainfalls over South Africa and Nino3.4 index were −0.66, −0.69 and −0.49 with KF, BMJ and GDE scheme respectively as compared to the observed correlation of −0.57. The model could reproduce the observed ENSO-South Africa rainfall relationship and could successfully simulate three wet (dry) years that are associated with La Nina (El Nino) and the BMJ scheme is closest to the observed variability. Also, the model showed good skill in simulating the excess rainfall over South Africa that is associated with positive subtropical Indian Ocean Dipole for the DJF season 2005/2006.

The prediction skill of dynamical downscaling is evaluated for climate forecasts over southern Africa using the Advanced Research Weather Research and Forecasting (WRF) model. As a case study, forecasts for the December–February (DJF) season of 2011/12 are evaluated. Initial and boundary conditions for the WRF model were taken from the seasonal forecasts of the Scale Interaction Experiment-Frontier Research Center for Global Change (SINTEX-F) coupled general circulation model. In addition to sea surface temperature (SST) forecasts generated by nine-member ensemble forecasts of SINTEX-F, the WRF was also configured to use SST generated by a simple mixed layer Price–Weller–Pinkel ocean model coupled to the WRF model. Analysis of the ensemble mean shows that the uncoupled WRF model significantly increases the biases (errors) in precipitation forecasted by SINTEX-F. When coupled to a simple mixed layer ocean model, the WRF model improves the spatial distribution of precipitation over southern Africa through a better representation of the moisture fluxes. Precipitation anomalies forecasted by the coupled WRF are seen to be significantly correlated with the observed precipitation anomalies over South Africa, Zimbabwe, southern Madagascar, and parts of Zambia and Angola. This is in contrast to the SINTEX-F global model precipitation anomaly forecasts that are closer to observations only for parts of Zimbabwe and South Africa. Therefore, the dynamical downscaling with the coupled WRF adds value to the SINTEX-F precipitation forecasts over southern Africa. However, the WRF model yields positive biases (>2°C) in surface air temperature forecasts over the southern African landmass in both the coupled and uncoupled configurations because of biases in the net heat fluxes.

Xiphinema stockeri n. sp. is described from Botswana The new species is characterized by an exceptionally long and conspicuous peg on the tail, and seems to be most closely related to X. mammatum Siddiqi, 1979, from which it can be distinguished by the a ratio, odontostyle and total stylet length, spicule length, the shape of the lip region and tail peg and the presence of a pseudo-z differentiation in X. stockeri.

The Archaeological Journal, 90, 18-25

The Archaeological Journal, 93, 1-12

Windblown transport and deposition of dust is widely recognized as an important physical and chemical concern to climate, human health and ecosystems. Sistan is a region located in southeast Iran with extensive wind erosion, severe desertification and intense dust storms, which cause adverse effects in regional air quality and human health. To mitigate the impact of these phenomena, it is vital to ascertain the physical and chemical characteristics of airborne and soil dust. This paper examines for the first time, the mineralogical and chemical properties of dust over Sistan by collecting aerosol samples at two stations established close to a dry-bed lake dust source region, from August 2009 to August 2010. Furthermore, soil samples were collected from topsoil (0-5 cm depth) at several locations in the dry-bed Hamoun lakes and downwind areas. These data were analyzed to investigate the chemical and mineralogical characteristics of dust, relevance of inferred sources and contributions to air pollution. X-ray Diffraction (XRD) analysis of airborne and soil dust samples shows that the dust mineralogy is dominated mainly by quartz (30-40%), calcite (18-23%), muscovite (10-17%), plagioclase (9-12%), chlorite (~6%) and enstatite (~3%), with minor components of dolomite, microcline, halite and gypsum. X-ray Fluorescence (XRF) analyses of all the samples indicate that the most important oxide compositions of the airborne and soil dust are SiO(2), CaO, Al(2)O(3), Na(2)O, MgO and Fe(2)O(3), exhibiting similar percentages for both stations and soil samples. Estimates of Enrichment Factors (EFs) for all studied elements show that all of them have very low EF values, suggesting natural origin from local materials. The results suggest that a common dust source region can be inferred, which is the eroded sedimentary environment in the extensive Hamoun dry lakes lying to the north of Sistan.

Verpleegkundigen kunnen het beloop van specifieke gezondheidsproblemen van kwetsbare ouderen gunstig beïnvloeden. Dat kan alleen als ze deze problemen tijdig inschatten en verbanden kunnen leggen tussen de verschillende problemen en de wisselwerking die deze op elkaar hebben. Het klinisch redeneren bij kwetsbare ouderen wordt in het beroepsprofiel verpleegkundige expliciet genoemd als belangrijke vaardigheid om dit doel te bereiken. 'Klinisch redeneren bij ouderen' biedt de kennis die verpleegkundigen nodig hebben om, samen met de oudere, kritische besluiten te nemen in alle stappen van het verpleegkundige proces.