The WHO UNESCO FIP Pharmacy Education Taskforce: enabling concerted and collective global action
- Authors: Anderson, Claire , Bates, Ian , Beck, Diane , Brock, Tina , Futter, William T , Mercer, Hugo , Rouse, Mike , Wuliji, Tana , Yonemura, Akemi
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6348 , http://hdl.handle.net/10962/d1006029 , http://dx.doi.org/10.1186/1478-4491-7-45
- Description: Pharmacy Education is a priority area for the International Pharmaceutical Federation (FIP), the global federation representing pharmacists and pharmaceutical scientists worldwide that is spearheading the Global Pharmacy Education Taskforce. This paper describes the work of the Taskforce that was established in March 2008, explores key issues in pharmacy education development, and describes the Global Pharmacy Action Plan 2008-2010. Given the significance of pharmacy education to the diverse practice of contemporary pharmacists and pharmacy support personnel, there is a need for pharmacy education to attain greater visibility on the global human resources for health agenda. From this perspective, FIP is steering the development of holistic and comprehensive pharmacy education and pharmacy workforce action to support and strengthen regional, national, and local efforts. The role of a global organization such as FIP is to facilitate, catalyze, and share efforts to maximize pharmacy education development and stimulate international research to develop guidance, tools, and better understanding of key issues. To achieve this goal, FIP has (1) established a formal collaborative partnership with the 2 United Nations agencies representing the education and health sectors, United Nations Educational, Scientific and Cultural Organization (UNESCO) and the World Health Organization (WHO); and (2) established the Global Pharmacy Education Taskforce to serve as the coordinating body of these efforts. The initial effort will serve to leverage strategic leadership and maximize the impact of collective actions at global, regional, and national levels. Three project teams have been convened to conduct research, consultations and develop guidance in the domains of vision for pharmacy education, competency, quality assurance, academic workforce, and institutional capacity.
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- Date Issued: 2008
Shoppers Drug Mart or poachers Drug Mart?
- Authors: Attaran, Amir , Walker, Roderick B
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6346 , http://hdl.handle.net/10962/d1006018
- Description: [From the text]: Shoppers Drug Mart (Pharmaprix in Quebec) is a familiar Canadian institution. Its 1000 stores dot the landscape; no pharmacy chain is larger. In many Canadian communities, the corporation's well-staffed local franchises give patients quality care. However, in South Africa, the same corporation is potentially contributing to a public health disaster. In 2005, 2006 and twice in 2007, it has dispatched recruiters to that country, with the mission of plucking pharmacists from a continent that has far too few for its needs. Shoppers Drug Mart promises 6-figure salaries and help to establish a brilliant career in Canada. The carrot, and the helping hand holding it, are huge.
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- Date Issued: 2008
Global diversity of mayflies (Ephemeroptera, Insecta) in freshwater
- Authors: Barber-James, Helen M , Gattolliat, J-L , Sartori, Michel , Hubbard, Michael D
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6895 , http://hdl.handle.net/10962/d1011655
- Description: The extant global Ephemeroptera fauna is represented by over 3,000 described species in 42 families and more than 400 genera. The highest generic diversity occurs in the Neotropics, with a correspondingly high species diversity, while the Palaearctic has the lowest generic diversity, but a high species diversity. Such distribution patterns may relate to how long evolutionary processes have been carrying on in isolation in a bioregion. Over an extended period, there may be extinction of species, but evolution of more genera. Dramatic extinction events such as the K-T mass extinction have affected current mayfly diversity and distribution. Climatic history plays an important role in the rate of speciation in an area, with regions which have been climatically stable over long periods having fewer species per genus, when compared to regions subjected to climatic stresses, such as glaciation. A total of 13 families are endemic to specific bioregions, with eight among them being monospecific. Most of these have restricted distributions which may be the result of them being the relict of a previously more diverse, but presently almost completely extinct family, or may be the consequence of vicariance events, resulting from evolution due to long-term isolation.
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- Date Issued: 2008
A synopsis of the Afrotropical Tricorythidae
- Authors: Barber-James, Helen M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:7003 , http://hdl.handle.net/10962/d1008362
- Description: The Tricorythidae of the Afrotropical Region is currently composed of five described genera, three of which are thought to be restricted to Madagascar (Madecassorythus Elouard and Oliarioniny, Ranorythus Oliarinony and Elouard, and Spinirythus Oliarinony and Elouard), one which is restricted to Africa (Dicercomyzon Demoulin), and one which is thought to be distributed on both landmasses (Tricorythus Eaton). Based on sexual dimorphism, manifest in the relative eye size of mature male and female nymphs and adults and on the structure of the genitalia of adult males, it is proposed that there are two additional genera in Africa, as yet undescribed. One of these genera is represented by a species currently placed in Tricorythus (T. discolor [Burmeister]). Several other undescribed species within South Africa have been identified as belonging to the group. A second lineage is represented by Tricorythus tinctus Kimmins, from Uganda, the only currently described species. There are also several more undescribed species of this group widespread in Africa.
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- Date Issued: 2008
The effects of load and gradient on hand force responses during dynamic pushing and pulling tasks
- Authors: Bennett, Anthea I , Desai, Sheena D , Todd, Andrew I , Freeland, H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6757 , http://hdl.handle.net/10962/d1009459
- Description: The limited attention afforded to push/pull activities and the motion phases (initial, sustained and ending) characteristic of these tasks has prompted a research focus in this area. The present study examined biomechanical responses in the form of hand forces during dynamic submaximal trolley pushing and pulling. Participants pushed/pulled loads of 100, 200 and 300 kg on the level (determining impact of load) or pushed 100 kg along a 12° ramp (uphill and downhill- determining impact of gradient). During level exertions significant differences (p<0.05) in hand forces occurred between loads of 100 and 200 kg, and 100 and 300 kg for initial and sustained forces but not ending forces. Values were similar for pushing and pulling at respective loads and motion phases. Strong correlations indicate that initial forces can be used to accurately estimate sustained and ending forces. Importantly, correct technique is essential in force reduction. Forces were highest during uphill initial and sustained phases and the downhill sustained phase. For the initial phase, the forces were highest during uphill pushing (86.5 ± 25.73 N); for the sustained phase, there was no difference between uphill and downhill forces but level forces were significantly lower (18.19 ± 8.09 N) than either of the other two conditions; for the ending phase, the highest forces were produced during downhill pushing (-53.34 ± 13.65N). As sustained forces equaled or exceeded initial forces for uphill and downhill efforts, consideration of sustained forces may be appropriate in determining the inherent potential risk of graded pushing.
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- Date Issued: 2008
Enigmatic trace fossils from the Aeolian lower Jurassic Clarens formation, Southern Africa
- Authors: Bordy, Emese M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6730 , http://hdl.handle.net/10962/d1007538
- Description: The Lower Jurassic aeolienites of the Clarens Formation in southern Africa contain unique sedimentary structures that are unlikely to be non-biogenic. They are also unlike any known modern or ancient trace fossils. Here, some nigmatic, horizontal,regularly-oriented sedimentary structures are described, which occur in association with other trace fossils as well as features that were previously nterpreted as nests of termites or termite-like ancient social nsects. These spectacular structures are exposed in enormous profusion as straight, ~5 mm cylinders with strong compass orientation, in parallel alignment with one another and to ancient horizontal bedding planes. Their fill is identical to that of the host rock: clean, well-sorted, very fine- to finegrained quartz-arenite. In cross-section, each structure is defined by a subtle, ~0.1 mm thin, concentric gap. Without comparable modern biogenic structures, the biological origin of the structures is uncertain. Their strong compass orientations are, however, also inconsistent with an inorganic origin, even though they may resemble pipey concretions generated by flowing groundwater. Nonetheless, this paper, based on spatiotemporal distribution patterns of the oriented structures, their locally high abundance and association with obvious trace fossils, as well as other sedimentological and palaeontological lines of evidence, argues that the compass structures may be products of ancient social invertebrates living in a resource-limited, semi-arid to arid environment. Furthermore, the compass structures as well as the accompanying structures of the predominantly aeolian Clarens Formation collectively imply the recurrence of favourable ecological parameters (e.g., moist ubstrates) related to episodic climate fluctuations in the Early Jurassic of southern Pangaea (i.e., southern Gondwana).
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- Date Issued: 2008
A xylem retrieval pathway in rice leaf blades – evidence of a role for endocytosis?
- Authors: Botha, Christiaan E J , Aoki, N , Scofield, G N , Liu, Lin , Furbank, R T , White, R G
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6505 , http://hdl.handle.net/10962/d1005930 , http://dx.doi.org/10.1093/jxb/ern150
- Description: The structure and transport properties of pit membranes at the interface between the metaxylem and xylem parenchyma cells and the possible role of these pit membranes in solute transfer to the phloem was investigated. Electron microscopy revealed a fibrillar, almost tubular matrix within the pit membrane structure between the xylem vessels and xylem parenchyma of leaf blade bundles in rice (Oryza sativa). These pits are involved primarily with regulating water flux to the surrounding xylem parenchyma cells. Vascular parenchyma cells contain large mitochondrial populations, numerous dictyosomes, endomembrane complexes and vesicles in close proximity to the pit membrane. Taken collectively this suggests that endocytosis may occur at this interface. A weak solution of 5,6-carboxyfluorescein diacetate (5,6-CFDA) was applied to cut ends of leaves and after a minimum of 45 minutes, the distribution of the fluorescent cleavage product, 5,6-carboxyfluorescein (5,6-CF) was observed using confocal microscopy. Cleavage of 5,6-CFDA occurred within the xylem parenchyma cells and the non-polar 5,6-CF was then symplasmically transported to other parenchyma elements and ultimately, via numerous pore plasmodesmata, to adjacent thick-walled sieve tubes. Application of Lucifer Yellow, and, separately, Texas Red labelled dextran (10 kDa) to the transpiration stream, confirmed that these membrane-impermeant probes could only have been offloaded from the xylem via the xylem vessel-xylem parenchyma pit membranes, suggesting endocytotic transmembrane transfer of these membrane-impermeant fluorophores. Accumulation within the thick-walled sieve tubes, but not in thin-walled sieve tubes, confirms the presence of a symplasmic phloem loading pathway, via pore plasmodesmata between xylem parenchyma and thick-walled sieve tubes, but not thin-walled sieve tubes.
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- Date Issued: 2008
Texts, practices and student learning: a view from the South
- Authors: Boughey, Chrissie
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6085 , http://hdl.handle.net/10962/d1008482
- Description: This article uses ‘close-up’ ethnographic research to provide an account of students’ engagement with learning in a South African university. Broadly based on Halliday’s (1973, 1978, 1994) understanding of texts resulting from contexts, the account challenges dominant constructions of the problems students encounter as stemming from the use of inappropriate ‘approaches’ to learning, the lack of ‘study’ and other skills or problems with proficiency in areas such as writing or language and shows how students’ unfamiliarity with the context of the university leads them to draw on ‘other’ contexts in order to engage with the texts they must read, write and listen to in the course of their studies. This drawing on ‘other’ contexts then results in the texts produced by students, and the practices which give rise to those texts, being inappropriate to the context of the university. Although the research on which the article is based took place in South Africa, it is argued that the theoretical perspective it provides has relevance across other contexts given the increasingly diverse student bodies which characterize higher education across the globe.
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- Date Issued: 2008
The assessment and treatment of post-abortion syndrome : a systematic case study from Southern Africa
- Authors: Boulind, Melissa , Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6270 , http://hdl.handle.net/10962/d1008270
- Description: This article reports a clinical case study of "Grace", a black Zimbabwean woman with post-abortion syndrome (PAS), a form of post-traumatic stress disorder precipitated by aborting an unwanted pregnancy. She was treated by a middle class white South African trainee Clinical Psychologist. The case narrative documents the assessment and the course of treatment which was guided by ongoing case formulation based on current evidence-based models. Factors that made her vulnerable to developing PTSD included active suppression of the memory of the event and lack of social support. An understanding of these factors was used to guide an effective intervention. In spite of the differences in culture and background between client and therapist, there was considerable commonality in their experience as young women and students who each had to balance personal and occupational priorities. The narrative also highlights the commonalities of Grace's experiences with those reported in the literature on post-abortion syndrome, which is mostly from the U. S. A. and Europe.
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- Date Issued: 2008
Hydrolytic enzymes in sewage sludge treatment: a mini-review
- Authors: Burgess, Jo E , Pletschke, Brett I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6478 , http://hdl.handle.net/10962/d1006166 , http://hdl.handle.net/10520/EJC116535
- Description: Biological wastewater treatment processes can be classified as either aerobic or anaerobic. These two biological treatment processes are each characterised by groups of micro-organisms and their associated enzymes. Hydrolytic enzymes secreted by these micro-organisms are vital for the rate-limiting step of hydrolysis in the treatment of highly polymeric substrates present in sewage sludge. In this mini-review, the effects of mass transfer limitation, metabolic intermediates, extracellular polymeric substances (EPS), electron acceptor conditions and pH and temperature on the activity of these enzymes are summarised. The most salient and current perspectives of the significance and the role that hydrolytic enzymes play in sewage sludge treatment are highlighted.
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- Date Issued: 2008
Do environmental factors influence the movement of estuarine fish? A case study using acoustic telemetry
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Thorstad, Eva B , Økland, F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6772 , http://hdl.handle.net/10962/d1008070
- Description: Telemetry methods were used to investigate the influence of selected environmental variables on the position and movement of an estuarine-dependent haemulid, the spotted grunter Pomadasys commersonnii (Lacepède 1801), in the Great Fish Estuary, South Africa. Forty individuals (263–698 mm TL) were surgically implanted with acoustic coded transmitters and manually tracked during two periods (7 February to 24 March 2003; n = 20 and 29 September to 15 November 2003; n = 20). Real-time data revealed that spotted grunter are euryhaline (0–37) and are able to tolerate large variations in turbidity (4–356 FTU) and temperature (16–30 °C). However, the fish altered their position in response to large fluctuations in salinity, temperature and turbidity, which are characteristic of tidal estuarine environments. Furthermore, tidal phase had a strong influence on the position of spotted grunter in the estuary.
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- Date Issued: 2008
Relationship between energy intake and expenditure during harvesting tasks
- Authors: Christie, Candice J
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6758 , http://hdl.handle.net/10962/d1009461
- Description: The objective of this study was to compare the energy demands of manual harvesting tasks with the associated energy intake of the workers’. Fifty eight workers (29 Chainsaw Operators and 29 Stackers) were assessed in South Africa prior to, and during a ‘normal’ working shift. Habitual dietary analyses showed that the workers were eating less than 56% of the recommended daily allowance and were thus arriving at work with reduced energy stores. Heart rate responses were measured continuously during work and energy expenditure was predicted from the heart rate/oxygen uptake relationship obtained at a post-work progressive step up test completed by each worker. The data indicated that the tasks placed ‘moderate-to-heavy’ demands on the workers resulting in a significant imbalance between the energy demands of the tasks and the associated energy intake of the workers. Energy deficits were in excess of 8 000 kJ and workers lost, on average, 2.8% body mass during work while felling and cross-cutting, and 3.6% during stacking.
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- Date Issued: 2008
Nuclear translocation of the phosphoprotein Hop (Hsp70/Hsp90 organizing protein) occurs under heat shock, and its proposed nuclear localization signal is involved in Hsp90 binding
- Authors: Daniel, Sheril , Bradley, Graeme , Longshaw, Victoria M , Söti, Csaba , Csermely, Peter , Blatch, Gregory L
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6472 , http://hdl.handle.net/10962/d1005951 , http://dx.doi.org/10.1016/j.bbamcr.2008.01.014
- Description: The Hsp70–Hsp90 complex is implicated in the folding and regulation of numerous signaling proteins, and Hop, the Hsp70–Hsp90 Organizing Protein, facilitates the association of this multichaperone machinery. Phosphatase treatment of mouse cell extracts reduced the number of Hop isoforms compared to untreated extracts, providing the first direct evidence that Hop was phosphorylated in vivo. Furthermore, surface plasmon resonance (SPR) spectroscopy showed that a cdc2 kinase phosphorylation mimic of Hop had reduced affinity for Hsp90 binding. Hop was predominantly cytoplasmic, but translocated to the nucleus in response to heat shock. A putative bipartite nuclear localization signal (NLS) has been identified within the Hsp90-binding domain of Hop. Although substitution of residues within the major arm of this proposed NLS abolished Hop–Hsp90 interaction as determined by SPR, this was not sufficient to prevent the nuclear accumulation of Hop under leptomycin-B treatment and heat shock conditions. These results showed for the first time that the subcellular localization of Hop was stress regulated and that the major arm of the putative NLS was not directly important for nuclear translocation but was critical for Hop–Hsp90 association in vitro. We propose a model in which the association of Hop with Hsp90 and the phosphorylated status of Hop both play a role in the mechanism of nucleo-cytoplasmic shuttling of Hop.
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- Date Issued: 2008
Deriving narrow syntax through constraints on information structure : a parallel between linguistic models of displacement and database theory
- Authors: de Vos, Mark
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6142 , http://hdl.handle.net/10962/d1011594
- Description: This paper presents a research program for normalization-driven syntax. It takes the Minimalist research agenda as a starting point (Chomsky 1995. The Minimalist Program. MIT Press, Cambridge MA.) and explores the question of how the CI interface determines syntactic operations. The proposal provides specific content to the notion of bare output conditions and the nature of the CI interface. It does so by drawing on the tools provided by Relational Theory, a branch of set-theoretic mathematics, and Database Theory, a branch of computer science. It is demonstrated that core components of Narrow Syntax (phrase structure, selection and AGREE) are all definable in terms of Relational Theory. Then, it is shown that the process of relation optimization, or normalization, can derive chain formation. The article concludes with two speculations on the implementation of phases within a normalization-driven grammar and the implications of such a system for the learnability of the lexicon.
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- Date Issued: 2008
Photophysicochemical and Fluorescence quenching studies of benzyloxyphenoxy substituted zinc phthalocyanines
- Authors: Durmuş, Mahmut , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6570 , http://hdl.handle.net/10962/d1004133
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetrakis- and octakis(4-benzyloxyphenoxy)-substituted zinc phthalocyanines (1, 2 and 3). General trends are described for photodegradation, and fluorescence quantum yields, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds in dimethylsulphoxide (DMSO) and toluene. The fluorescence of the complexes is quenched by benzoquinone (BQ), and fluorescence quenching properties are investigated in DMSO and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2 and 3) are also reported. Photophysical and photochemical properties of phthalocyanine complexes are very useful for PDT applications.
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- Date Issued: 2008
Handling multiple levels of data and multiple research questions in an embedded case study : methodological challenges
- Authors: Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6247 , http://hdl.handle.net/10962/d1007865
- Description: Hougaard et al. report an embedded case study in which nine socially phobic clients were treated as part of a therapy program, which incorporated individual and group therapy and which was largely delivered by trainee clinicians. An important focus of the report is on the effectiveness of their treatment model. This commentary draws attention to the size and complexity of the available data, and it suggests ways in which the use of a more explicitly interpretative methodology can draw out additional dimensions of the data and allow a more systematic contribution to be made to the development of clinical theory.
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- Date Issued: 2008
A phenomenological case study of a lecturer's understanding of himself as an assessor
- Authors: Grant, Rosemary
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6087 , http://hdl.handle.net/10962/d1008582
- Description: Based on the findings of research conducted as part of a doctoral study aimed at obtaining an understanding of what it means to be an assessor in higher education, this paper outlines the experience of an individual lecturer at a South African university and describes the meaning he makes of his practice as an assessor within the context of a changing understanding of the nature and purpose of higher education. Making a case for personal agency and innovation as critical qualities in the assessment endeavour, the researcher suggests that, in contrast to a view of education increasingly focused on standardization, accountability and outcomes, student assessment is essentially a human encounter in which the humanity and emotions of both lecturer and student need to be acknowledged.
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- Date Issued: 2008
A global study of forensically significant calliphorids: implications for identification
- Authors: Harvey, M L , Gaudieri, S , Villet, Martin H , Dadour, I R
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6863 , http://hdl.handle.net/10962/d1011156
- Description: A proliferation of molecular studies of the forensically significant Calliphoridae in the last decade has seen molecule-based identification of immature and damaged specimens become a routine complement to traditional morphological identification as a preliminary to the accurate estimation of post-mortem intervals (PMI), which depends on the use of species-specific developmental data. Published molecular studies have tended to focus on generating data for geographically localised communities of species of importance, which has limited the consideration of intraspecific variation in species of global distribution. This study used phylogenetic analysis to assess the species status of 27 forensically important calliphorid species based on 1167 base pairs of the COI gene of 119 specimens from 22 countries, and confirmed the utility of the COI gene in identifying most species. The species Lucilia cuprina, Chrysomya megacephala, Ch. saffranea, Ch. albifrontalis and Calliphora stygia were unable to be monophyletically resolved based on these data. Identification of phylogenetically young species will require a faster-evolving molecular marker, but most species could be unambiguously characterised by sampling relatively few conspecific individuals if they were from distant localities. Intraspecific geographical variation was observed within Ch. rufifacies and L. cuprina, and is discussed with reference to unrecognised species.
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- Date Issued: 2008
Ectomycorrhizas in association with Pinus patula in Sabie, South Africa
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
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- Date Issued: 2008
Temporal and spatial variability in stable isotope ratios of SPM link to local hydrography and longer term SPM averages suggest heavy dependence of mussels on nearshore production
- Authors: Hill, Jaclyn M , McQuaid, Christopher D , Kaehler, Sven
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6969 , http://hdl.handle.net/10962/d1012034
- Description: Temporal changes in hydrography affect suspended particulate matter (SPM) composition and distribution in coastal systems, potentially influencing the diets of suspension feeders. Temporal variation in SPM and in the diet of the mussel Perna perna, were investigated using stable isotope analysis. The δ13C and δ15 N ratios of SPM, mussels and macroalgae were determined monthly, with SPM samples collected along a 10 km onshore–offshore transect, over 14 months at Kenton-on-Sea, on the south coast of South Africa. Clear nearshore (0 km) to offshore (10 km) carbon depletion gradients were seen in SPM during all months and extended for 50 km offshore on one occasion. Carbon enrichment of coastal SPM in winter (June–August 2004 and May 2005) indicated temporal changes in the nearshore detrital pool, presumably reflecting changes in macroalgal detritus, linked to local changes in coastal hydrography and algal seasonality. Nitrogen patterns were less clear, with SPM enrichment seen between July and October 2004 from 0 to 10 km. Nearshore SPM demonstrated cyclical patterns in carbon over 24-h periods that correlated closely with tidal cycles and mussel carbon signatures, sampled monthly, demonstrated fluctuations that could not be correlated to seasonal or monthly changes in SPM. Macroalgae showed extreme variability in isotopic signatures, with no discernable patterns. IsoSource mixing models indicated over 50% reliance of mussel tissue on nearshore carbon, highlighting the importance of nearshore SPM in mussel diet. Overall, carbon variation in SPM at both large and small temporal scales can be related to hydrographic processes, but is masked in mussels by long-term isotope integration.
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- Date Issued: 2008