White blood cell phagocytosis was investigated and used with avian blood, and assessed as a potential biomarker for mercury immunotoxicity in free ranging birds (common loons). Phagocytosis is an essential immunological function and can be measured using flow cytometry. The assay was assessed with in vitro exposure using whole blood and isolated white blood cells (WBC) from domestic chickens, and with in vivo exposure using whole blood from captive doves and wild loons. McHg at 0.1ppm significantly depressed phagocytic capacity of isolated WBCs without affecting their viability, but did not affect phagocytic activity when added to whole blood up to 50ppm. Also, no significant relationship between blood-Hg level and phagocytic capacity of WBCs was observed in ringed turtle doves fed McHg in their diets, nor in wild common loons having a range of blood-Hg concentrations. The phagocytosis assay is a convenient assay for use in field studies of free-living birds, but is not responsive to McHg exposure in birds, and so is not recommended as a biomarker of immunotoxicity in Hg-exposed loons.

No description available.

No description available.

Our alarming rate of resource exploitation and its consequences on the environment is fuelling an increase in sustainable energy production around the world. Wind power appears to be a particularly promising energy source relative to its environmental footprint, with the exception of potential negative effects of wind power on birds. Varying results from impact assessments around the world indicate that knowledge of both abiotic and biotic factors, as well as bird behavior and ecology, is required to assess the cumulative impact of any given wind farm on local bird communities. This study aims to assess the cumulative impact of a proposed wind farm on a threatened seabird, the red-throated diver (Gavia stellata), at one of its breeding "hotspots" in Sweden: the Holmöarna islands. Measurements of environmental variables in lakes on Holmöarna are combined with breeding surveys from 2012 to 2015 to assess which environmental variables may be associated with lakes that red-throated divers do or do not breed in, and which variables are correlated with breeding success. These results are combined with a literature review to assess the potential negative effects of the proposed wind farm on the breeding population on Holmöarna. The results show that average breeding success over the survey period was 0.35 fledged young per pair per year. No difference was found in environmental variables between lakes that divers had or had not bred in. Lake area/perimeter ratio and distance to the sea were significantly negatively correlated with breeding success, although distance to the sea was only significant for lakes with at least one successful breeding attempt during the survey period. Based on these correlations, 33 of a total 40 breeding lakes are shown to have relatively high area/perimeter ratios and long distances to the sea, which may pre-dispose divers breeding within them to low breeding success. These lakes are, therefore, identified as being at high-to-moderate risk of increased breeding failure if breeding success is further reduced as a result of external factors, including that of any negative impacts of the proposed wind farm. 31 of the 40 breeding lakes are also within 1 km of the proposed wind turbine sites, which may render red-throated divers breeding within them vulnerable to displacement as a result of wind farm-related disturbance. The literature review highlights the mechanisms that may determine the cumulative impact of the wind farm on red-throated divers in terms of collision mortality, habitat displacement, and barriers to movement. The strong sensitivity of red-throated divers to disturbance is considered to be the most likely driver of any negative effects of the wind farm. In this context, I thus argue the need for a precautionary approach to planning wind power developments in the vicinity of breeding red-throated diver populations.

AFRIKAANS : Hierdie studie is onderneem om te bepaal wat die persepsies van boere in die Letaba Distrik is oor die invloed van die instelling van die minimum loon vir landbou op hulle boerderybesighede. Die navorser wou bepaal of die boere hulle werknemers se werkskontrakte aangepas het of die loonpakket geherstruktureer het om vir die invloed op hulle boerderybesigheid te kompenseer. Die navorser wou ook bepaal of die indiensneming van plaaswerkers beïnvloed is. Laastens wou die navorser bepaal wat die invloed van die instelling van die minimum loon op die organisasiegedrag van plaaswerkers was. Om antwoorde op bogenoemde vraagstukke te verkry, het die navorser ‘n vraelys spesifiek vir die doeleindes van hierdie studie ontwerp. Die vraelys is deur al die sitrus boere in die Letaba distrik voltooi. Na bestudering van die inligting wat uit die data van die vraelyste verkry is, het die navorser tot die gevolgtrekking gekom dat boere permanente werknemers met tydelike werknemers vervang het en die loonpakket aangepas het deur die kontantloon te verhoog, maar ook die aftrekkings vir dienste en goedere wat voorheen kosteloos verskaf is. Indiensneming van plaaswerkers is baie negatief beïnvloed, met ongeveer 1270 permanente poste wat afgeskaf is na die instelling van die minimum loon. Wat die invloed op organisasiegedrag betref, het die minimum loon geen invloed na ‘n klein negatiewe invloed op afwesigheid en personeelomset getoon. Ten opsigte van produktiwiteit was werkgewers van mening dat, waar produktiwiteit verhoog het, dit as gevolg van beter bestuurspraktyke was. Werkgewers glo eerder dat die instelling van die minimum loon hulle werknemers se produktiwiteit laat daal het. Die implikasies van die resultate van hierdie studie is verreikend wanneer in ag geneem word dat bykans 1270 permanente poste op slegs 38 plase afgeskaf is. Dit impliseer dat die aantal poste wat in die landbou as geheel afgeskaf is, baie groot kan wees. Die persepsies van die boere oor die instelling van die minimum loon was dat dit ‘n bedreiging vir die volhoubaarheid van hulle boerderybesighede inhou en dat dit hulle verplig om stappe te neem om daarvoor te kompenseer, stappe wat nie noodwendig tot voordeel van werknemers strek nie. ENGLISH : This study was undertaken to ascertain what the perceptions of farmers in the Letaba district aren about the impact of the introduction of the minimum wage for agriculture on their farming businesses. The researcher wanted to ascertain whether the farmers adapted their workers’ contracts or restructured their wage package to compensate for the impact on the farming businesses. The researcher also wanted to ascertain whether the employment of farm workers were influenced. Lastly, the researcher wanted to ascertain what the influence of the introduction of the minimum wage was on the organisational behaviour of farm workers. To get answers on the above mentioned issues, the researcher designed a questionnaire specifically for this study. The questionnaire was completed by all the citrus farmers in the Letaba district. After studying the information derived from the data of the questionnaires, the researcher came to the conclusion that farmers substituted permanent workers with temporary workers and adapted the wage package by raising the cash wage but also the deductions of goods and services that were previously provided free of charge. Employment of farm workers were influenced very negatively with about 1270 permanent jobs that were scrapped after the introduction of the minimum wage. Regarding the impact on organisational behaviour, the minimum wage showed a small negative to no influence on absenteeism and worker turnover. Regarding productivity, employers were of the opinion the, where productivity was raised, it was due to improved management practises. Employers believe that the introduction of the minimum wage caused their workers’ productivity to decrease. The implications of the results of this study are far reaching when it is taken into account that roundabout 1270 permanent jobs were lost on only 38 farms. This implies that the amount of jobs lost in agriculture as a whole, could be great. The perceptions of farmers about the introduction of the minimum wage are that it is a threat to the sustainability of their farming businesses and that it obliges them to take steps to compensate for the impact, steps that aren’t always advantageous for the workers. Copyright 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Minnaar, ME 2008, Persepsies oor die uitwerking van minimum lone op die sitrusbedryf (Afrikaans), MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02132012-100400 / > C12/4/72/gm / Dissertation (MCom)--University of Pretoria, 2012. / Human Resource Management / unrestricted

I offer a cloud of observations about language and art. I will prioritize my questions about how language operates in art, the way it functions within my own studio practice, and locate aesthetic interstices throughout. There will be insights gleaned from the various orderers of order (Lacan, Saussure) and orderers of disorder (Derrida, Agamben), walks in terra-incognita, and even some poetry on my part. I will take this chance to orient myself among different structures and deconstructions that have piledup around language, aesthetics and art.