Environmentally sustainable houshold consumption: From aggregate environmental pressures to indicators for priority fields of action

During the UNCED conference in Rio de Janeiro 1992 unsustainable consumption and production patterns were identified as one of the key driving forces behind theunsustainable development of the world (Agenda 21, chapter 4). These consumption and production patterns are based on the European model of industrialisation, spread around the globe in the age of colonisation and brought toextremes by the upper-class of industrialised societies, in particular in the United States, but also in a number of countries in the South. Therefore, all states of theworld share the task of developing sustainable consumption and productionpatterns, while particular responsibility rests with the industrialised nations of Europe, North America and Japan. They, and the thriving but small rich elite in the transition countries and in the South, form a global consumer society, with shared products, lifestyles and aspirations. As it is essential to support the transition towards sustainable development byproviding the proper information in an operational manner, the UNCED conference has called for the development of suitable means of information, and in particular for the development of sustainability indicators applicable throughout the world (Agenda 21, chapter 40). The UNDESA set of indicators for changingconsumption and production patterns offers helpful advice in this regard but stilllacks the theoretical underpinning needed to consistently complete it by definingthe few still missing indicators.This paper undertakes to suggest such a methodology based on the environmental space concept. It derives a set of science based indicators from this approachwhich are easily applicable in everyday life and analyses the environmentalrelevance of the consumption clusters chosen for analysis as well as the relevanceof the phenomena characterised by the indicators suggested. As households arejust one actor in the field of consumption, a qualitative assessment of influences isperformed and the result depicting the key actors for each environmentallyrelevant consumption cluster is presented as an actor matrix. --

Sustainability indicators: A compass on the road towards sustainability

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Towards integrated long-term scenarios for assessing biodiversity risks

From a policy point of view, the rapid loss of biodiversity (how ever measured) constitutes an urgent need to improve the ability to forecast possible changes in biodiversity. Scenario development and modelling are essential tools for studying changes of biodiversity and their impacts in order to provide well-founded policy options. However, so far no comprehensive model has been developed integrating the diverse relevant ecological, economic, individual and societal processes. Instead socio-economic, climate and biodiversity models exhibit a wide range of assumptions concerning population development, economic growth and the resulting pressures on biodiversity. The paper summarises the efforts undertaken in the framework of the ALARM project by an interdisciplinary team of economists, climatologists, land use experts and modellers. It describes the challenges of such a kind of work, bringing together different world views unavoidably inherent to the different fields of investigation

Effects of Clinostat Rotation on Aurelia Statolith Synthesis

Aurelia ephyrae develop eight graviceptors (rhopalia) during their metamorphosis from polyps, which are used for positional orientation with respect to gravity. In three experiments for each speed of 1/15, 1/8, 1/2, 1, and 24 rpm, groups of six polyps were rotated in the horizontal or vertical plane (control) using clinostats. Other controls were kept stationary in the two planes. Ten ephyrae from each group were collected after 5 to 6 days at 27 C in iodine and the number of statoliths per rhopalium were counted. Statistical analyses of statolith numbers revealed that horizontal clinostat rotation at 1/4 and 1/2 rpm caused the formation of significantly fewer statoliths per rhopalium than were found in controls. The finding that these slow rates of rotation reduces statolith numbers suggests that the developing ephyrae were disoriented with respect to gravity at these speeds, causing fewer statocytes to differentiate or to mineralize

Time-domain ptychography

Through dedicated measurements in the optical regime we demonstrate that ptychography can be applied to reconstruct complex-valued object functions that vary with time from a sequence of spectral measurements. A probe pulse of approximately 1 ps duration, time delayed in increments of 0.25 ps is shown to recover dynamics on a ten times faster time scale with an experimental limit of approximately 5 fs.Comment: 5 pages, 4 figures, new title and minor text change

Validation of the high performance leadership competencies as measured by an assessment centre in-basket

The original publication is available at http://www.sajip.co.zaCITATION: Spangenberg, H. H. & Theron, C. C. 2003. Validation of the high performance leadership competencies as measured by an assessment centre in-basket. SA Journal of Industrial Psychology, 29(2):29-38, doi:10.4102/sajip.v29i2.106.The purpose of this study was to validate Schroder’s High Performance Leadership Competencies (HPLCs), measured by a specially designed In-basket, against multiple criteria. These consisted of six measures of managerial success, representing managerial advancement and salary progress criteria, and a newly developed comprehensive measure of work unit performance, the Performance Index. An environmental dynamism and complexity questionnaire served as moderator variable. Results indicated disappointing predictive validity quotients for the HPLCs as measured by an In-basket, in contrast to satisfactory predictive and construct validity obtained in previous studies by means of a full assessment centre. The implications of the findings are discussed and suggestions are made for improving the validity of the In-basket.Die doel van hierdie studie was die validering van Schroder se Hoëvlak Leierskapsbevoegdhede, gemeet deur ‘n spesiaal ontwerpte Posmandjie, teen veelvoudige kriteria. Dit behels ses metings van bestuursukses wat bestuursbevorderings- en salarisvorderingskriteria insluit, sowel as ‘n nuutontwikkelde, omvattende meting van werkeenheidsprestasie, die Prestasie indeks. ‘n Vraelys wat die dinamika en kompleksiteit van die omgewing meet, het as moderator veranderlike gedien. Resultate dui op teleurstellende geldigheidskwosiënte vir die Hoëvlak Leierskapsbevoegdhede soos gemeet deur ‘n posmandjie, in teenstelling met bevredigende voorspellings- en konstrukgeldigheid wat in vorige studies deur middel van ‘n volle takseersentrum verkry is. Die bevindinge word bespreek en voorstelle word gemaak om die geldigheidskwosiënte te verbeter.https://sajip.co.za/index.php/sajip/article/view/106Publisher's versio

Engineering students' actions in a mathematical modelling task: Mediating mathematical understanding in a computer algebra system

Many engineering subjects rely on the interpretation of symbolic, numeric and graphic representations. Engineering students have challenges pertaining to their mathematical understanding of their actions with a computer algebra system (CAS). We investigated how a mathematical modelling task could mediate varied levels of mathematical understanding. When engineering students are exposed to a CAS environment, they habitually engage in programming activities without considering the computerised outputs. The purpose of this paper was to ascertain South African engineering students’ actions that can mediate broader levels of mathematical understanding in a CAS by utilising the Pirie- Kieren model of growth in mathematical understanding. Thirteen participants agreed to engage collaboratively in a mathematical modelling task. The task was analysed by means of content analysis following a deductive research approach. The findings disclosed that engineering students interdepend on paper-and-pen, computerised and reflective actions in their growth of mathematical understanding. Engineering students can be assisted in mediated and folding-back actions in order to fluctuate back and forth on their way to a more sound mathematical understanding. Explicit planning and sequence of subtasks can support engineering students to merge new levels of mathematics understanding with past comprehensions. Thoroughly planned modelling tasks can mediate novel levels of mathematical understanding when engineering students learn with a CAS

Neural Prediction Errors Distinguish Perception and Misperception of Speech

Humans use prior expectations to improve perception, especially of sensory signals that are degraded or ambiguous. However, if sensory input deviates from prior expectations, correct perception depends on adjusting or rejecting prior expectations. Failure to adjust or reject the prior leads to perceptual illusions especially if there is partial overlap (hence partial mismatch) between expectations and input. With speech, “Slips of the ear” occur when expectations lead to misperception. For instance, a entomologist, might be more susceptible to hear "The ants are my friends" for "The answer, my friend" (in the Bob Dylan song "Blowing in the Wind"). Here, we contrast two mechanisms by which prior expectations may lead to misperception of degraded speech. Firstly, clear representations of the common sounds in the prior and input (i.e., expected sounds) may lead to incorrect confirmation of the prior. Secondly, insufficient representations of sounds that deviate between prior and input (i.e., prediction errors) could lead to deception. We used cross-modal predictions from written words that partially match degraded speech to compare neural responses when male and female human listeners were deceived into accepting the prior or correctly reject it. Combined behavioural and multivariate representational similarity analysis of functional magnetic resonance imaging data shows that veridical perception of degraded speech is signalled by representations of prediction error in the left superior temporal sulcus. Instead of using top-down processes to support perception of expected sensory input, our findings suggest that the strength of neural prediction error representations distinguishes correct perception and misperception