The Effect of Trellis Systems on the Performance of Vitis vinif era L. cvs. Sultanina and Chenel in the Lower Orange River Region

The effect of six trellis systems on the reproductive and vegetative performance of Sultanina and Chene), grown in the lower Orange River region of South Africa, was investigated. Larger trellis systems significantly increased the yield of both cultivars, and the photosynthetic activities of the leaves at veraison as well as the canopy light environment tended to be higher for these systems. The higher yields recorded for Sultanina were attributed to improved budding percentages, which were caused by improved light environments at the basal 'buds. The improved yield obtained for Chene! however, was due to higher bunch masses, which were most likely caused by the higher photosynthetic activities of the leaves

Predicting the Date of Bud Burst in Grapevines

It was possible to forecast the date of bud burst under South African winter temperatures (Region III) using the Pouget-formulae and principles, and to establish a scale of bud burst for cultivars grown in South Africa. The sum of daily temperature effects was higher under the warmer South African conditions which resulted in changes in the formulae for determining the daily effect of temperature and the cultivar coefficient on the bud burst date. Highly significant linear relationships were, however, obtained and it was possible to predict the date of bud burst fairly accurately

Preparation of Epidermal Tissues for Light Microscope Studies of Vitis - leaves

A method for preparing epidermal tissues of leaves of Vitis spp. for the study of surface characteristics with the aid of a light microscope is described. Certain morphological characteristics such as trichrome length and frequency, stomata frequency, diameter and index of two cultivars were determined by means of a light microscope which compared very favourably with the results obtained when using a scanning electron microscope

Leachability of nitrided ilmenite in hydrochloric acid

Titanium nitride in upgraded nitrided ilmenite (bulk of iron removed) can selectively be chlorinated to produce titanium tetrachloride. Except for iron, most other components present during this low temperature (ca. 200°C) chlorination reaction will not react with chlorine. It is therefore necessary to remove as much iron as possible from the nitrided ilmenite. Hydrochloric acid leaching is a possible process route to remove metallic iron from nitrided ilmenite without excessive dissolution of species like titanium nitride and calcium oxide. Calcium oxide dissolution results in unrecoverable acid consumption. The leachability of nitrided ilmenite in hydrochloric acid was evaluated by determining the dissolution of species like aluminium, calcium, titanium and magnesium in a batch leach reactor for 60 minutes at 90°C under reflux conditions. The hydrochloric acid concentration (11%, 18% and 25%), initial acid-to-iron mole ratio (2:1, 2.5:1 and 3.3:1), and solid-to-liquid mass ratio (1:8.33 to 1:2.13) were varied. The results indicate that a hydrochloric acid concentration of 25 wt% supplied in a 2:1 acid-to-iron mole ratio would produce the most favourable upgraded nitrided ilmenite product. The dissolution of iron in this solution reached 97 per cent after only 60 minutes. The total dissolution of calcium and titanium species was 0.01 and 0.11 wt% respectively. Hydrochloric acid can therefore be used as lixiviant to remove metallic iron from nitrided ilmenite.http://www.saimm.co.za/ai201

An information systems ownership framework

Organisations deploy information systems (IS) with the exclusive intention to pursue their business objectives. Executive managers assign ownership of IS to business leaders, expecting them to leverage the IS towards achieving the objectives of the business areas. Many business leaders are reluctant to take ownership of the IS in their business areas, placing the organisation at risk that IS may not be optimally utilised and business areas not attaining their objectives. Little guidance exists to understand what 'taking ownership of IS' entails. In the research, a framework for understanding IS ownership was developed through a process of induction. The IS ownership framework discusses the different perspectives of the role-players with respect to defining IS ownership, the rationale for IS ownership, the criteria for having ownership and the rights, obligations and expectations associated with IS ownership.http://www.inderscience.com/jhome.php?jcode=IJBIS2021-07-03hj2021Informatic

Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets

Experience of imposed educational change by a heterogeneous group of teachers.

From the extensive research on educational change undertaken world-wide, it is evident that its implementation has often failed, due to various reasons. A reason that is very often given in this regard is that initiators of educational change do not keep in mind that successful implementation of change and its sustainability require, first and foremost, an inherent change in the human being. For almost a decade, the s have participated in various international research projects directed at understanding how teachers experience educational change and how it influences their work lives. They report on the insights from one of these studies, which dealt specifically with the differences in experience of imposed post-apartheid educational changes by teachers who had worked previously in the different sections of the ethnic-based education system prior to 1994. The expectations of teachers regarding the new education dispensation and their experiences of the reality of policy implementation are addressed.(South African Journal of Education: 2003 23 (2): 94-100

A Numerical-Taxonomic classification of Vitis spp and Cultivars Based on Leaf Characteristics

Grapevine leaves collected from three positions on the shoot during veraison were investigated for taxonomic characteristics. Numerical analyses were employed on 13 ampelographical and 13 morphological characteristics. Characteristics contributing to the variation between taxa were mainly quantitative. Although not clearly perceptible specimens tended to cluster in American (Vi tis spp and hybrids) and European (Vi tis vinifera) groups. Using the ampelographical characteristics hybrids tended to cluster with at least one of their parents

Smartphone hearing screening with integrated quality control and data management

OBJECTIVE : To determine if a smartphone application could be used as a calibrated screening audiometer with real-time noise monitoring for school screening using automated test sequences. DESIGN : The investigation comprised three studies. Study 1 evaluated calibration accuracy across four Samsung S5301 smartphones (Android v4.0.4) using commercial Sennheiser HD202 headphones. Study 2 involved referencing smartphone microphone sensitivity to narrowband noise intensity as measured in octave bands by a sound-level meter between 30 and 75 dB SPL (5 dB increments). Study 3 compared screening outcomes of smartphone based and conventional hearing screening. STUDY SAMPLE : Study 2: 15 normal-hearing subjects (age range, 18 – 22 years; all female). Study 3: 162 children (324 ears) aged 5 to 7 years. RESULTS : Smartphone calibration at 20, 30, and 40 dB was within 1 dB of recommended reference equivalent thresholds levels. Microphone calibration for noise monitoring had maximum variability across phones of 0.9, 0.6, and 2.9 dB at 1, 2, and 4 kHz, respectively, from reference intensities (30 to 75 dB SPL). Screening outcomes demonstrated no signifi cant difference between smartphone and conventional audiometry with an overall referral rate of 4.3% and 3.7%, respectively. CONCLUSIONS : The newly developed smartphone application can be accurately calibrated for audiometry with valid real-time noise monitoring, and clinical results are comparable to conventional screening.http://informahealthcare.com/loi/ijahb201