Personal and behavioural variables and the self-regulated learning abilities of African learners

Accepting responsibility for one's learning is not only an important variable that influences effective learning, but is also one of the main characteristics of selfregulated learning. Self-regulated learners know how to use their knowledge of the personal (e.g. goal setting) and behavioural variables (e.g. learning strategies) that affect learning to their advantage. Within the context of self-regulated learning, much emphasis is placed on the role of the self and self-knowledge. In this article self-regulated learning and the role of the self are evaluated from a Christian perspective. In the research underlying this article it was established that, although there were some statistically significant relationships between some personal and behavioural variables and the self-regulated learning abilities of African students, these relationships were not of practical significance. The results of the research led to the conclusion that the subjects lacked knowledge of themselves as learners

Epistemologiese oortuigings en die onderrigen leerhandeling

Epistemological convictions with regard to teaching and learning It is often assumed by teaching-learning specialists that teaching and learning are proportionally related technical activities, and can be accurately measured in examinations or experiments. The fact that teaching and learning are respectively, as well as in combination with each other, embedded in a multitude of pre-scientific and scientific presuppositions is frequently overlooked. This discussion is aimed at revealing that views and standpoints regarding teaching and learning can hardly be substantial or plausible without cognisance and evaluation of the epistemological convictions in which they are grounded. Such convictions also determine the nature of their application in actual class-room practice

A mathematical function for crop growth based on light interception and leaf area expansion.

As an alternative to the Richards Function, a physiologically based mathematical function was developed which assumes that, when light is limiting, CGR is proportional to intercepted radiation and therefore to an exponential function of leaf area. The name 'expolinear' growth equation is proposed. The function is illustrated using sorghum, faba beans and oil palms as examples. Implications for optimum growth strategies are reviewed and caveats are entere

Long-wave radiation at the ground

The apparent emissivity of the atmosphere ϵ, defined as the ratio of incoming long-wave radiation to black-body radiation at screen temperature Tₐ, was measured under clear skies in the English Midlands and in the Sudan. At a zenith angle Z the emissivity was given by ϵ(Z) = a + bIn(usec Z) where u is the reduced depth of precipitable water (cm). For a set of 46 scans in England, the mean values of a and b were 0·70±0·05 and 0·090 ± 0·002. Systematic deviations about these mean values could be ascribed to: (i) temperature gradients; (ii) aerosol. The Sudan measurements gave a = 0·67 ± 0·03 and b = 0·085 ± 0·002 consistent with the English results and observations already published. There is some evidence that minimum values of a have increased over the past 50 years. Integration over the hemisphere gives the flux density (Wm−2) of atmospheric radiation as 1·06 σTₐ⁴ − 119 (T in K), where σ is Stefan's constant, or 5·5 Tₐ + 213 (T in °C). Radiation records by Dines and Dines (1927) for overcast skies are analysed to show that the angular distribution is the same as for cloudless skies; that the mean temperature of cloud base at their site was UK below screen temperature; and that when the mean fraction of cloud cover is c, the apparent emissivity is ϵa(c) = (1 − 0·84c)ϵa(0) + 0·84c

Scale issues in soil moisture modelling: problems and prospects

Soil moisture storage is an important component of the hydrological cycle and plays a key role in land-surface-atmosphere interaction. The soil-moisture storage equation in this study considers precipitation as an input and soil moisture as a residual term for runoff and evapotranspiration. A number of models have been developed to estimate soil moisture storage and the components of the soil-moisture storage equation. A detailed discussion of the impli cation of the scale of application of these models reports that it is not possible to extrapolate processes and their estimates from the small to the large scale. It is also noted that physically based models for small-scale applications are sufficiently detailed to reproduce land-surface- atmosphere interactions. On the other hand, models for large-scale applications oversimplify the processes. Recently developed physically based models for large-scale applications can only be applied to limited uses because of data restrictions and the problems associated with land surface characterization. It is reported that remote sensing can play an important role in over coming the problems related to the unavailability of data and the land surface characterization of large-scale applications of these physically based models when estimating soil moisture storage.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline