Spatial and temporal variability in recruitment of intertidal mussels around the coast of southern Africa

Intensity of intertidal mussel recruitment was compared across a range of different spatial and temporal scales around the coast of southern Africa between June 1995 and October 1996. Comparison of the east and west coasts revealed significantly higher recruit densities on the west coast, corresponding to larger adult densities. This difference between the two coasts reflects biogeographic disparities in mussel species composition, growth rates and spawning intensities, oceanographic conditions and productivity. Significant spatial variations in recruitment were recorded between regions 100–1000 km apart and between localities 1–25 km apart. Results suggest that the influence of dispersal processes on recruitment patterns acts at a relatively small scale, and may affect the distribution and abundance of adults among shores only a few kilometres apart. The high variability in recruitment intensities at a scale of metres indicates that larva! supply to the shore may be locally patchy, or that settlement preferences of recruits may be sensitive to subtle small-scale differences in adult density within mussel clumps. Small-scale differences in post-settlement mortality (e.g. owing to patchy predation pressure) may also play a role. This small-scale variability in recruitment is likely to reinforce the mosaic distribution of mussels evident on many of the shores. Significant temporal variability in recruit density was recorded, both between 3-monthly sampling intervals and interannually. Seasonal differences were absent for the north-west regions, whereas asynchronous seasonal patterns were displayed in the other regions. Results suggest that temporal cycles of recruitment are irregular and episodic, which may have important consequences for the dynamics of adults. Significant positive correlations were obtained between maximal recruitment and adult abundance, measured by density, or total number of adults on the shore (stock). This could be explained by the density-dependent role of adult conspecifics in providing suitable settlement habitat, or supply-side recruit limitation. These results have important implications for the management of exploited populations of mussels around the coast of southern Africa. Exploitation may influence recruitment success via at least two processes: reduction of larval supply by depletion of adult stock, and alteration of habitat suitable for settlement. Thus, overexploitation will compromise recruitment, which is itself the only mechanism of recovery. The west-coast mussel populations are likely to be more resilient to exploitation as recruitment is more predictable over time, stocks are larger and recruitment intensities high. This brings into question the present regulations for mussel harvesting because, paradoxically, more lenient regulations are applied on the east coast, where stocks and recruitment are low, than on the west coast, where biomass, recruitment and potential for recovery are high

Knowledge production and research development in science and technology at higher education institutions in the Eastern Cape Province

Thesis (MPhil)--Stellenbosch, 2001.ENGLISH ABSTRACT: The aims of this study were to establish whether there had been discernable changes in the nature of knowledge production at higher education institutions in the Eastern Cape since the transition to democracy, and to relate these to international and national trends in the way knowledge is produced. In view of the emphasis in government policy on the development of science and technology, the study was focused on researchers in this area and on the administration of research in this context. The research was conducted through structured interviews with administrators and active researchers at the three technikons and five universities in the province. The study found that there had indeed been changes, both in the way research is managed, and in the nature of the research itself. Research has become more applied over the last five years and there has been a move towards multidisciplinary, multi-institutional research, although administrators tended to underestimate the extent of this change. Research management has also become businesslike with the establishment of dedicated Deans/Directors of research on most campuses. Administrators ascribe these changes to new government policies and to changes in the requirements of funding agencies. Researchers, however, generally ascribe the changes to factors more directly related to themselves, such as changes in institutional research policy, more opportunities for multidisciplinary work and to greater linkage with the private sector. The study also found that many of the changes were already underway some time ago and that there was a degree of proactiveness in the way some institutions had realigned their research. The study found that there are significant differences between formerly advantaged institutions and their historically disadvantaged counterparts. The latter are dominated by less well qualified staff and produce fewer research outputs than the former. Research cultures are less well developed and researchers complain of a lack of institutional support for research. Despite this, research continues to be a significant activity on these campuses. In general, staff at technikons are more positive about the future of research than their colleagues at universities, irrespective of historical advantage. The study found that knowledge production has assumed some of the characteristics of so-called Mode 2 knowledge production as a result of a variety of national and international influences, and historically advantaged institutions have been able to initiate adjustments to the way in which research is done in anticipation of new policies. Publication of government policy on science and technology and on higher education may have accelerated the change but did not initiate it. The historically disadvantaged institutions, however, appeared to have done little in anticipation of new policy and have been forced to be reactive to recent government initiatives.AFRIKAANSE OPSOMMING: Die doel van die studie was om ondersoek na die voorkoms van waarneembare veranderinge in die karakter van die lewering van kennis by hoer-onderrig institute in die Oos- Kaap, na die oorgang van demokrasie, in te stel. Verder is gepoog om hierdie veranderinge in verband met internasionale en nasionale tendense, met betrekking to die wyse waarop kennis voortgebring word, te bring. In die lig van die regering se beleid aangaande die ontwikkeling van wetenskap en tegnologie was die studie op navorsers in hierdie rigting, sowel as die aanpassing van navorsing in hierdie konteks, gefokus. Die ondersoek was deur middel van gestruktureerde onderhoude met administrateurs en aktiewe navorsers aan die drie tegnikons and vyf universiteite in hierdie provinsie uitgevoer. Die ondersoek het aangedui dat veranderinge in die wyse waarop navorsing bestuur word en in die karakter van navorsing op sigself, inderdaad plaasgevind het. Navorsing het gedeurende die afgelope vyf jaar toenemend toepaslik geword en hoewel administrateurs geneig het om die omvang daarvan te onderskat, was daar 'n merkbare verplasing na multidissiplinere en multi-institution ale navorsing. Die administrasie van navorsing het ook, na die aanstelling van teogewyde Dekane/Direkteurs van navorsing by die meerderheid kampusse, toenemend bedryfsgerig word. Administrateurs skryf hierdie verplasing toe aan die nuwe staatsbeleid sowel as die veranderinge in die voorskrifte van befondsingsliggame. Op hul beurt skryf navorsers die varanderinge egter aan faktore wat meer op hulself van toepassing is, toe. Hierdie faktore sluitveranderinge in die institutionele beleid, die toename in geleenthede met betrekking tot multi-dissiplinere werk, sowel as die toename in skakeling met die private sektor, in. Dit is gevind dat verskeie van hierdie veranderinge al 'n geruime tyd onderweg is en dat daar 'n mate van pro-aktiwiteit met betrekking tot die wyse waarop sommige institute hul navorsing hers poor het, bestaan. Die studie het bevind dat betekenisvolle verskille tussen voormalige bevoorregte institute en hul histories onbevoorregte ekwivalente voorgekom het. U it die resultate het dit duidelik geword dat die personeel van die laasgenoernde institute oor die algemeen minder gekwalifiseerd is en dat 'n laer navorsingsopbrengs geproduseer word. Die navorsingskultuur is minder ontwikkel en navorsers is ontevrede oor die gebrek aan institutionele ondersteuning wat navorsing aanbetref. Ten spyte hiervan is navorsing voortdeurend 'n betekenisvolle akwitiwiteit op hierdie kampusse. Personeel verbonde aan tegnikons is oor die algemeen meer positief oor die toekoms van navorsing in teenstelling met hul kollegas verbonde aan universitiete, ongeag die historiese agtergrond. Die studie het ook bevind dat, weens die verskeidenheid nasionale en internasionale invloede en die oorspronklike aanpassings wat historiese bevoorregte institute tot stand laat kom het met betrekking tot die wyse waarop navorsing, met die oog op nuwe beleid, uitgevore word, die produksie van kennis van die eienskappe van "Mode 2" aangeneen word. Die bekendmaking van die staatsbeleid aangaande wetenskap en tegnologie en hoer-onderrig kon uit eie beweging hierdie veranderinge bespoedig het, maar het dit nie geinisieer nie. Histories onbevoorregte institute het tot dusver min werk gemaak van die vooruitsigte van die nuwe beleid en word genoodsaak om op onlangse regerings inisiatiewe te reageer

Mechanism in the detonation regime : final report

http://deepblue.lib.umich.edu/bitstream/2027.42/7650/5/bad2110.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/7650/4/bad2110.0001.001.tx

The Performance of State Economic Development Programs: An Impact Evaluation

Reports on an impact evaluation designed to verify state economic development programs. Relationship between state spending on economic development and economic vitality; Priority attention by states to economic development