Creating a Web-based Spatiotemporal GIS using Java and VRML
- Authors: Clayton, Peter G , Wells, George C , Preston, Michael
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433413 , vital:72968 , https://www.learntechlib.org/p/7417/
- Description: This paper presents our approach towards creating a Web-based Spatiotemporal Geographic Information System, in particular, the creation of the spatial data set and the component interaction. It explores the possibility of rendering Virtual GIS Worlds in near real time across the WWW using a standard Web browser as the user interface. A" proof of concept" Web-based VGIS application was developed to investigate methods for the efficient transfer of high-bandwidth multimedia GIS content over the WWW, as well as providing a suitable development environment for research into Web-based Temporal GIS. This paper describes how VRML and Java were used to provide the visualisation of virtual worlds, interaction with individual objects inside the virtual world, and the query tools for adding, deleting, selecting or manipulating these objects or their associated attribute data.
- Full Text:
- Date Issued: 1999
Graphicacy as a form of communication
- Authors: Wilmot, P Dianne
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6091 , http://hdl.handle.net/10962/d1008613
- Description: Children of today inhabit a multi-dimensional world and in order to communicate effectively in it they need the ability to utilise four forms of communication namely, oracy, literacy, numeracy and graphicacy. Communicating in graphic form requires an ability to both encode and decode spatial information using symbols which requires the utilisation and application of spatial perceptual skills and concepts. The draft Curriculum Framework for General and Further Education and Training identifies graphic literacy as one of the critical outcomes of the new South African curriculum. Spatial information about the environment is most frequently communicated in the graphic mode. Yet if graphicacy is to be recognised as an essential mode of communication and, as such, a vital element in education, then we need to seek ways of developing and introducing an explicit and critical pedagogy in our schools to foster the development of graphic and critical graphic literacy. But first, the skills and concepts integral to graphicacy need to be identified and understood. This article provides a framework for thinking about graphicacy as a form of communication in the General Education and Training (GET) band, the compulsory component of South African education (Grades 1-9).
- Full Text: false
- Date Issued: 1999
Guy Butler (obituary)
- Authors: Wright, Laurence
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:7052 , http://hdl.handle.net/10962/d1007411
- Description: An obituary focusing on Guy Butler's Shakespearean preoccupations. The 1999/2000 volume of Shakespeare in Southern Africa only appeared in 2001. The Butler obituary was included as a 'stop-press' item as the volume went to print, which accounts for the apparent anomaly between the date of publication and the date of Guy Butler's death.
- Full Text:
- Date Issued: 1999
Honeybees, Apis mellifera Linnaeus (Hymenoptera: Apidae), of equatorial Africa
- Authors: Radloff, Sarah E , Hepburn, H Randall
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451885 , vital:75083 , https://hdl.handle.net/10520/AJA10213589_364
- Description: Morphometric and flight dimensional characters of worker honeybees, Apis mellifera Linnaeus, from equatorial Gabon were analysed by multivariate methods to characterize the population. A single morphocluster and a single flight dimension cluster were obtained. When these bees were grouped together with those of other countries of the region, again a single morphoduster and flight cluster were obtained. All of the outlier samples were previously designated as Apis mellifera adansonii Latreille and completely surround the Gabon samples, establishing the same subspecies membership for the latter. The bees of Gabon are morphometrically more homogeneous than in any other area of Africa.
- Full Text:
- Date Issued: 1999
Lack of a response of the sub-tropical rodent (Saccostomus campestris) to a secondary plant compound, 6-methoxybenzoxazolinone—consequences for reproductive strategy
- Authors: White, Rehema M , Bernard, Ric T F
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447273 , vital:74601 , https://www.ajol.info/index.php/az/article/view/154795
- Description: A potential strategy for southern African small mammals to maximise reproductive success is to cue breeding activity to rainfall and subsequent vegetative growth via a secondary plant compound such as 6-methoxybenzoxazolinone (6MBOA). This study investigated whether the sub-tropical rodent Saccostomus campestris utilised this compound to enhance reproductive activity. 6MBOA or control vehicle were injected into adult females and into peri-pubertal females under long day (LD) and short day (SD) photoperiods (adults n= 6 to 8: peri-pubertals n= 5 to 10/treatment). There was no significant effect of 6MBOA or photoperiod on uterine or ovarian masses nor on ovarian development in sacrificed animals, nor on age at vaginal opening of peri-pubertals It was concluded that 6MBOA is not a major stimulant of reproduction in this species. Rather, we propose that seasonal breeding occurs in response to multiple environmental cues. This reproductive strategy and omnivory permit.
- Full Text:
- Date Issued: 1999
The Virtual Remote Control-An Extensible, Virtual Reality, User Interface Device
- Authors: Rorke, Michael , Bangay, Shaun D
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432743 , vital:72896 , https://www.cs.ru.ac.za/research/Groups/vrsig/pastprojects/013interaction/paper02.pdf
- Description: Immersive virtual reality (VR) places the user inside of the computing envi-ronment, blurring the distinction between the environment itself and the user interface to access that environment non-obvious. This lack of distinction between environment and interface makes it difficult to place menus and other interface elements where the user is both able to access them easily and where they do not obscure large parts of the users field of view. We propose a system called the 'Virtual Remote Control' (VRC). The VRC con-sists of a physical device (a small touchpad tracked using a Polhemus In-sideTrak magnetic tracker) which the user is able to hold and for which there is a representation in the virtual environment. The VRC is represented in the environment by a virtual menu. The user is able to make selections from the virtual menu by moving their finger around the touch pad part of the VRC and 'tapping' on the required action. Additionally, the user is able to select an object for the action to be applied on, by 'pointing' the representa-tion of the VRC at the object-as one would point a remote control at a Hi-fi of TV set.
- Full Text:
- Date Issued: 1999
The Winter's Tale shaping our own Renaissance. A play for the 21st Century
- Authors: Wright, Laurence
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455874 , vital:75464 , https://hdl.handle.net/10520/AJA1011582X_198
- Description: The Winters Tale is an extraordinarily elusive play. My contention in this paper" is that, just as Hamlet became the Shakespearean drama for the nineteenth century, and King Lear spoke deeply to the twentieth centu-ry, so it may well be that The Winters Tale will take centre stage for the new millennium. We used to know what the play was about in an easy, non-problematic fashion. It was about repentance and reconciliation; it was about the cycle of the seasons; it was about the Pandosto sub-title,“The Triumph of Time"; later, it became a tricksy celebration of con-tention between Art and Nature (despite the considerable discomfort inflicted upon the dramatis personae), an experiment in the new genre of tragicomedy, or a glittering theatrical tour de force–a romance, but heartless and rather empty. I would maintain that beneath all such read-ings is the assumption that the play is really “a winter's tale': a some-what inconsequential yarn suitable for whiling away a cold evening round the fireside, a view often infused with some lingering taint of the Edwardian view that Shakespeare had “gone sloppy” in his technique."
- Full Text: false
- Date Issued: 1999
Thermoregulatory capabilities of the woodland dormouse, Graphiurus murinus
- Authors: Whittington-Jones, Craig A , Brown, C R
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447349 , vital:74613 , https://doi.org/10.1080/02541858.1999.11448485
- Description: The woodland dormouse, Graphiurus murinus, in common with many other small rodents, enters torpor under conditions of food deprivation and low temperatures. Its thermoregulatory capabilities under more favourable conditions, however, have not been investigated. We measured metabolism and thermoregulation in woodland dormice acclimated to long-day length, moderate temperature and abundant food over a temperature range (Ta) of approximately 5–37°C. The thermal neutral zone for this species lay between 29 and 35°C. Estimated resting metabolic rate (RMR) within this range averaged 21.10 ± 3.28 J g-1 h-1.
- Full Text:
- Date Issued: 1999
COSATU press statement on the CEC decisions
- Authors: COSATU
- Date: May 1998
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/109730 , vital:33184
- Description: The COSATU Central Executive Committee met in its first session of the year over two days (5-6May 1998). The CEC received reports on a variety of issues and tool a number of policy decisions and approaches by on these matters. The CEC was characterised by anger and frustration on the scale of job losses in many industries and the failure of the current macro economic strategies to turn this tide around. Below are some of the issues discussed. The CEC endorsed the proposals submitted by Labour in NEDLAC on job 4^ creation in preparation for the Presidential Job Summit. The proposals will be further discussed in the coming Central Committee of COSATU scheduled for the 23-35 June 1998. COSATU shall use the Central Committee to further expand on the broad framework submitted in NEDLAC and get more proposals in line with how labour has categorised issues for the agenda of the Job Summit, i.e. (i) Measures to create jobs (ii) Measures to stop current job losses (iii) Measures to support the unemployed, (iv) Measures to assist the informal sector to be formal (v) Identification of long term issues to be negotiated beyond the Job Summit. COSATU is extremely concerned by the failure of both government and business to submit their proposals at NEDLAC. It is worth to note that various deadlines for them to submit proposals have passed. A million-dollar question is : Why does the government and business seem reluctant to submit their proposals? Clearly both government and business have abundance of capacity to deal with the proposals in a relatively short space of time. This is a major concern for COSATU. Whilst the delays continue, job losses are continuing unabated and the time bomb continue to click.
- Full Text:
- Date Issued: May 1998
Multivariate analysis of honeybee populations, Apis mellifera Linnaeus (Hymenoptera: Apidae), from western central Africa morphometries and pheromones
- Authors: Radloff, Sarah E , Hepburn, H Randall
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451963 , vital:75091 , https://hdl.handle.net/10520/AJA10213589_298
- Description: Morphometric characters and sting pheromones of worker honeybees, Apis mellifera Linnaeus, were analysed by multivariate methods to characterize their populations along a transect through three ecological-climatological zones in Cameroon. There are three distinct homogeneous populations and two zones of hybridization. These bees are designated as A. m. adansollii Latreille whose area of distribution is intruded by an A. m. montieola-like montane group of bees and a third group, A. m. jemertitica Ruttner. The delineation of the hybrid zones is supported by intercolonial variance spectra and these significant asymmetries are coincident with transitions between the ecological-climatological zones.
- Full Text:
- Date Issued: 1997
The human skin-blanching assay for in vitro topical corticosteroid assessment. I. Reproducibility of the assay
- Authors: Haigh, John M , Meyer, Eric , Smith, Eric W , Kanfer, Isadore
- Date: 1997
- Language: English
- Type: text , Article
- Identifier: vital:6381 , http://hdl.handle.net/10962/d1006299
- Description: The human skin blanching (vasoconstriction) assay for the assessment of topical corticosteroids has been in use for over 30 years, the intensity of the drug-induced blanching being assessed subjectively by eye. Both arms of several male and female volunteers are used for product application and more than one observer is used to estimate the degree of induced blanching. There are, therefore, numerous variables which are inherent in the assay procedure. This investigation consisted of three identical trials performed at 8-week intervals, utilising the same 18 volunteers and the same three observers in an attempt to address the question of reproducibility of the assay. From the results obtained it is clear that the assay methodology is capable of consistently distinguishing, on a rank order basis, between preparations which show similar blanching (chemically-equivalent formulations). The similarity of the results for the three individual trials gives considerable confidence to results produced using this methodology. An experiment designed to test the reproducibility of the blanching scores showed that the observers are capable of producing identical results even though visual observation is highly subjective.
- Full Text:
- Date Issued: 1997
Variation in foraging activity of Acanthochitona garnoti (Mollusca: Polyplacophora) from different habitats
- Authors: Cretchley, Robyn , Hodgson, Alan N , Gray David R , Reddy, Kasturi
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447642 , vital:74663 , https://www.ajol.info/index.php/az/article/view/154647
- Description: Activity of Acanthochitona garno {i was studied on an exposed horizon-tal platform of aeolian sandstone (I (enton-on-Sea-33'41'S; 26'40'E) and a quartzitic sandstone boulder shore (Cannon Rocks-33 44'S; 26'35'E), during 1994. In addition, the activity rhythms of chitons which were permanent inhabitants of high sbore rock pools at Kenton-on Sea were observed. All sites experienced semi-diurnal tides, the tidal range being about 1.9 m on mean spring tides. and 0.9 m on mean neap tides, with highest spring tides phased around.
- Full Text:
- Date Issued: 1997
Cicadas (Homoptera: Cicadidae) as indicators of habitat and veld condition in valley bushveld in the Great Fish River Valley, South Africa
- Authors: Villet, Martin H , Capitao, I R
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451670 , vital:75068 , https://journals.co.za/doi/pdf/10.10520/AJA10213589_213
- Description: Rural land-use in the Eastern Cape Province ranges from subsistence to commercial farming, with a few game reserves forming areas of active conservation. A large part of the Eastern Cape is covered by Valley Bushveld, a productive veld type dominating the Great Fish River Valley at elevations of 100-450 m (Dyer 1937; Acocks 1988). It is used for game, goat and cattle farming (Stuart-Hill 1991), but large areas have become degraded by overgrazing and invasion by alien or undesirable plants (La Cocket ai. 1990), often with an associated reduction in community richness (Dyer 1937; Acocks 1988). These effects are particularly persistent in this veld type because of the slow regeneration associated with severe climatic conditions (Dyer 1937; Lubke et ai. 1986; La Cock et al. 1990; Stuart-Hill 1991): a mean annual rainfall of only 350-500 mm, mainly between November and March, and temperatures peaking at 46 C in December and January (Acocks 1988). As a result, the more palatable plant species are becoming increasingly rare.
- Full Text:
- Date Issued: 1996
Karoo and Etendeks flood basalt provinces, southern Africa and the tectonic development of their adjacent margins:
- Authors: Marsh, Julian S , Watkeys, M K
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144868 , vital:38386
- Description: Southern Africa hosts remnants of two continental flood basalt provinces emplaced in association with fragmentation of Gondwana. The earliest is the 183 Ma Karoo Province whose relationship to continental breakup and sea floor spreading is complex. Geochemical stratigraphy, Ar-Ar Dating and palaeomagnetism indicate that Karoo mafic igneous rocks throughout Southern Africa were emplaced over a very short interval at 183 Ma.
- Full Text:
- Date Issued: 1996
Memorandum on recommendations
- Authors: Federation of South African Trade Unions and Transport and General Union
- Date: 1996
- Subjects: Federation of South African Trade Unions and Transport and General Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110132 , vital:33233
- Description: It is a welcome move that the Minister has ordered an investigation in the security services within 2 years of the last amendment which was in November 1977. Regular adjustment to minimum wages ere imperative in a situation of rising cost of living. In the past an interval of about 4 years have lapsed before a new investigation is begun. Another positive aspect of this investigation is that the conditions are being investigated simultaneously throughout the major industrial areas in South Africa. This will help in bringing about a uniformity in the conditions of a group of employee 3 who ail do basically the same type of work. It is regretted that the scope of the investigation only includes undertakings in which employers and employees ere associated for the purpose of guarding, protecting etc. In she past this has meant that a large group of security guards are left out completely from the purview of the investigation and are hence not covered by any industrial legislation especially in regards to hours of work.
- Full Text:
- Date Issued: 1996
Assessing penetration enhances for topical corticosteroids
- Authors: Smith, Eric W , Haigh, John M
- Date: 1995
- Language: English
- Type: Book chapter
- Identifier: vital:6442 , http://hdl.handle.net/10962/d1006629
- Description: From introduction: Topical corticosteroids have been used for a wide range of dermatological conditions for the last 4 decades. For many years the topical delivery system was a relatively simple cream or ointment base, with little thought given to improving the formulation as far as drug delivery was concerned. The main emphasis in the initial stages of development was on the alteration of the corticosteroid molecule, in an attempt to produce moieties with a higher intrinsic topical effect with lower mineralocorticoid side effects. Once this avenue of research was exhausted, attention was placed on the lipophilicity of the molecule with the production of various types of esters in an attempt to produce molecules which would pass through the stratum corneum (SC) with reasonable ease. In recent years the nature of the semisolid drug delivery base has received considerable attention.2-5The nature of the vehicle has a profound effect on the rate of release of the topical corticosteroid from the formulation and its passage through the SC. One of the most important aspects of the formulation of the base is the inclusion of substances which aid this trads-SC diffusion, the so-called penetration enhancers.6The modes of action of the various different types of penetration enhancers are reviewed elsewhere in this book. The best method for the assessment of the release of corticosteroids from topical formulations is obviously the clinical tri~. Clinical trials, however, are laborious, costly, and difficult to mount. Patients suffering from dermatological complaints are not ideal subjects for the testing of topical corticosteroid formulations as it is difficult to obtain standardized lesions which are necessary for the comparison of results between formulations. Alternatively, a number of in vitro models exist for this type of assessment, but it is often problematic to obtain correlation with the in vivo situation.
- Full Text:
- Date Issued: 1995
Seasonally monoestrous reproduction in the molossid bat, Tadarida aegyptiaca from low temperate latitudes (33 S) in South Africa
- Authors: Bernard, Ric T F , Tsita, Johannes N
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447333 , vital:74611 , https://doi.org/10.1080/02541858.1995.11448366
- Description: A histological study of reproduction in Egyptian free-tailed bats (Tadarida aegyptiaca) Irom the Eastern Cape Province of South Alrica (c. 33°S) showed that females were seasonally monoestrous. Copulation, ovulation and lerlilizalion occurred in August, at the encf of winter, and births in December, after a four-month pregnancy. These results are compared with those of other molossid bats from tower latitudes in Africa. We conclude that the monoestrous habit of the Egyptian Iree-tailed bat at 33°S may be due to its relatively long pregnancy, and to the short summer period during which minimum temperatures are high enough to ensure an abundance of nocturnal flying insects.
- Full Text:
- Date Issued: 1995
The cicada genus Stagea n. gen. (Homoptera Tibicinidae) systematics
- Authors: Villet, Martin H
- Date: 1994
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453886 , vital:75296 , https://doi.org/10.1080/03946975.1994.10539259
- Description: The monotypic genus Stagea n. gen. and the species S. platyptera n. sp. are described. The type was caught in Natal, South Africa. The genus shares several characters with the endemic South African genera Stagira Stål 1861 and Bavea Distant 1905.
- Full Text:
- Date Issued: 1994
Forward to one education department
- Authors: SADTU
- Date: 1993
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/155115 , vital:39856
- Description: As the elected minute secretary, from the Second AGC 1992, I took over the portfolio as acting Regional Secretary when Mundisa Sinuka resigned in October 1992. In SADTU, we can only have a successful union if all our branches are functioning effectively and our members are committed. Members on the ground have been demotivated and this makes our task all the more difficult. Branches tend to work during times of crisis and it should be borne in mind that SADTU is not a crisis union but is there to educate, bur id. protect and defend the rights of teachers.
- Full Text:
- Date Issued: 1993