The labour market today is characterized by flexibility and a demand on the individual of maintaining employability by remaining educated, experienced and by having a positive approach concerning being available after work hours. The aim of the study is to understand the relation between the current conditions of the labour market and its effects on employee mental health.  Throughout the study, several aspects have been investigated: Boundless work, availability after work hours, previous education, the distinction between work life and private life, and the effect of these aspects on mental health. The empirical material has been analyzed with the following theoretical framework: the Theory of Power, the Effort-Reward Imbalance Model and the Control-Demand model, including the later updated version with the third variable; work-related social support. The empirical material is gathered by eight semi- structured interviews.  The results of the study showed distinctions between how the demands of the labour market are perceived and how it affects mental health. Hence, the negative effects on mental health depend on the demands of availability after working hours, which in turn vary depending on previous education, a lack of support from manager and colleagues, and an experienced demand of employability.

För att utöva en vattenverksamhet krävs i princip alltid ett tillstånd. Dessa tillstånd har beroende på prövningsmyndighet och gällande lagstiftning haft olika benämningar, bland annat utlåtande, tillståndsbeslut och vattendom. Syftet med studien är att beskriva hur vattendomar arkiveras och är tillgängliga för att kunna hanteras vid fastighetsbildning. Detta då det i dag inte finns någon liknande sammanställning.  Metoderna som tillämpats i studien avser en kvalitativ undersökning som har utförts i form av intervjuer med myndigheter som håller arkiv med tillstånd för vattenverksamheter samt sakkunniga från andra aktörer, en enkät riktad till förrättningslantmätare med erfarenhet av vattendomar och juridisk metod. Den juridiska metoden syftade till att ge en bild av rättsläget och dess förändring avseende vattenverksamhet samt erhålla en djupare förståelse för vilka typer av tillstånd som meddelats historiskt. Avsikten med intervjuundersökningen var att klargöra vilka myndigheter som är arkivmyndigheter i dag samt vad de förvarar i sina arkiv och hur handlingarna är sökbara. Detta kompletterades med en enkät riktad till förrättningslantmätare för att erhålla en bild av hur vattendomar hanteras i fastighetsbildning.  Resultaten av studien visar att vattenrätten har reglerats i ett flertal lagstiftningar genom åren, de första redan under medeltiden och senaste förändringen var när miljöbalken inrättades. Vidare visar resultaten hur komplex situationen är på grund av antalet arkivmyndigheter och historiska förändringar vad gäller tillståndsprövningen och de myndigheter som utfört den. Tillstånd till vattenverksamhet har historiskt sett meddelats genom förrättningar, domstolsdomar eller andra myndighetsbeslut och dessa finns förvarade i olika arkiv beroende på när i tiden tillstånden utfärdades och vilken typ av verksamhet de gäller. Slutsatserna utifrån resultaten är att det i dag inte finns något tydligt tillvägagångssätt för att söka information om vattendomar. Tillgängligheten varierar beroende på var tillståndet är arkiverat samt vilket typ av tillstånd det gäller. Inga tillstånd är per definition otillgängliga, däremot kan det vara väldigt svårt att spåra somliga. / To exert a water enterprise, an official permission almost always is required. Depending on the authority which issued the permit and the legislation under which it was announced, these permits had different names. For instance, verdict, permit order and water rights court ruling. The purpose of the study is to describe how water rights court rulings are archived and how they are available to be handled in connection with property formation.  The methods applied in the study concerns a qualitative research carried out in the form of interviews with authorities keeping archives of water rights as well as experts from other organizations, a survey directed to cadastral surveyors and a legal method. The legal method was to provide a picture of the legal situation and its change related to water enterprise and obtains a deeper understanding of the types of permits issued historically. The purpose of the interview study was to clarify which authorities keep archives, what they keep in their archives and how documents are searchable. This was supplemented with the survey to obtain picture of how water rights are handled in property formation. No such compilation has previously been made.  The results of the study shows that water rights have been regulated in several laws over the years, initially in the Middle Ages and the latest change took place when the Swedish Environmental Code was established. Furthermore, the result indicates how complex the situation is due to the number of archive authorities and historical changes of the examining authorities. Permissions for water enterprise have historically been noticed via cadastral procedures, judgements or other official permissions, and the permissions are stored in various archives depending on when the permits were issued and what type of water enterprise they concern. The conclusions from the results are that today there is no clear approach how to search for documents regarding water rights court rulings. Availability varies depending on where the permits are archived and which type of permit it is. No permit is by definition inaccessible, however, it can be very difficult to locate some.

Students’ intention to stay within the higher education system is decreasing by the year, and even though more students are enrolling at universities annually, the percentage of students completing their studies is not satisfactory. The low completion rate is a concern not only in South Africa, but worldwide. Trends are identified as to why students do not complete their studies. This study seeks to focus on perceived social support, the students’ academic fit, the psychological conditions of meaningfulness and availability as well as the students’ engagement levels, and then to investigate if these constructs will influence their intention to stay. The proposed engagement model of May, Gilson, and Harter (2004) originally designed by George Kahn (1990), was used to determine whether social support and academic fit correlates positively with the psychological conditions, which may lead to engagement and increase a student’s intention to stay. A quantitative research design was used to investigate the universal challenge at hand, and it was descriptive in nature in order to gather specific information from the first-year students. A crossectional design was used. The research method consists of a literature review and an empirical study, presented in one research article. A convenience sample was used, and a total of 304 students completed the questionnaires. These questionnaires were based on the Multidimensional Scale of Perceived Social Support, the Psychological Conditions Scale, Academic Fit Scale, the Work Engagement Scale and the Intent to Leave Scale. Structural equation modelling methods were used, and implemented in AMOS to test the measurement and structural models. The fit-indices used to test if the model fit the data included the absolute fit indices such as Chi-square statistic, the Standardized Root Mean Residual (SRMR), and the Root-Means-Square Error of Approximation (RMSEA). The incremental fit indices which were used included the Tucker-Lewis Index (TLI) and the Comparative Fit Index. It was found that social support did not have an impact on the psychological conditions of meaningfulness and availability, but it had a direct and indirect (via academic fit) effect on intention to stay. This implies that the amount of support students receive has an influence on their intention to stay, and also increased their sense of belonging in their field of study. Academic fit was positively associated with the psychological conditions of meaning and availability, which means that if the student’s personality and field of study is aligned the student will feel that the course is meaningful to him, and he will invest more energy in his studies. Academic fit had direct effects on students’ intention to stay, which means that students who feel they belong in their field of study will also be more likely to stay at the educational institution. It was also found that if students experience a sense of psychological meaningfulness and availability they will be more engaged in their studies, which impact their intention to stay / MCom, Industrial Psychology, North-West University, Vaal Triangle Campus, 2012

The consequences of ingesting different carbohydrate solutions on fluid movement and availability have not been systematically examined. In addition, the role of carbohydrate in the post-exercise rehydration period has received little attention despite the need for substrate replenishment following exercise and the role of carbohydrates in stimulating water absorption in the intestine. The aims of this thesis were to assess fluid absorption characteristics and availability of solutions containing increasing concentrations of glucose and to evaluate their role in the restoration and maintenance of fluid balance following a period of exercise-induced dehydration. The ingestion of a single bolus of a commercially available hypertonic 18% carbohydrate solution (chapter 3) and a hypertonic 10% glucose solution (chapter 4) resulted in reductions in plasma volume that are most likely due to acute net secretion of water into the intestinal lumen. When investigating recovery of whole body hydration status after sweat loss, a hypertonic 10% glucose-electrolyte solution maintained whole body fluid balance for a longer period than a hypotonic 2% glucose-electrolyte solution and an electrolyte only solution when a fixed volume of fluid was consumed during a rehydration period of one hour following cycle exercise in the heat (chapter 5). When fluid was consumed ad libitum over a two hour period following similar cycle exercise in the heat, a hypertonic 10% glucose-electrolyte solution was as effective in restoring and maintaining fluid balance as a 2% hypotonic glucose-electrolyte solution and an electrolyte only solution (chapter 6). The reduced rate of gastric emptying that accompanies the ingestion of high carbohydrate solutions was likely to be the primary cause for the difference in urine production reported between thetrials during this study (chapter 7). In conclusion, ingestion of hypertonic carbohydrate solutions results in a reduction in extracellular fluid volume that is most likely due to secretion of water into the intestinal lumen and the carbohydrate content of an ingested solution is of importance in the post-exercise rehydration period.

Peatland ecosystems only cover 2-3 % of the Earth‟s surface but they represent significant carbon stores, holding approximately one third of the global soil carbon (C). The major peat forming genera Sphagnum appears to be highly sensitive to increased N availability. Many studies have shown decreased productivity of Sphagnum which could lead to a decrease in the amount of C stored, especially as many studies also show an increase in the decomposition rate with higher N deposition. However, the overall effects of N on CO2 fluxes of Sphagnum remain unclear. The present study aimed to look at the effects of increased N on Sphagnum productivity, decomposition and CO2 fluxes after long-term N additions (> 5 years) using a field experiment at Whim Moss in southern Scotland where N deposition has been manipulated employing a very realistic application coupled to rainfall since 2002. The experiment also has treatments with PK addition to test the effects of removing P and/or K-limitation. Measurements of plant tissue nutrient concentrations, visual assessments of Sphagnum viability, and pore water analysis were also carried out. Nitrogen additions increased tissue N, and decreased Sphagnum shoot extension and productivity. Simultaneous P and K additions alleviated the effects of N on tissue N concentrations and growth, although this was only significant for shoot extension. Visual assessments correlated well with tissue chemistry and productivity; the decline in health was associated with high %N and reduced productivity. Interestingly, in the present study increased N decreased the mass loss and again when PK was added with N decomposition rates were more similar to the control. With respect to the carbon balance of the site and the sustainability of peatlands the results suggest that the negative effect of N on C assimilation may be partially offset by the reduced decomposition rates. The CO2 measurements showed a large loss of C as CO2 from all the Sphagnum plots which was exacerbated by adding N especially when the air temperature increased. The positive temperature response of ecosystem respiration with N additions suggests that in high N deposition areas climate change and subsequent temperature rises will increase C losses from bogs.

<p>Osnovni cilj ove doktorske disertacije bio je da se razvije novi automatizovani dijagnostiĉki model. Zatim da se praktiĉnom primenom tog modela (na konkretnom primeru automatizovane dijagnostike vitalnih komponenti tehniĉkih sistema u realnim pogonskim uslovima razliĉitih grana industrije) tehno-ekonomskom analizom potvrdi glavna hipoteza disertacije: &bdquo;Automatizovana dijagnostika tehniĉkih sistema u industriji (bazirana na kori&scaron;ćenju raĉunara i drugih savremenih informaciono-komunikacionih tehnologija) doprinosi porastu nivoau pouzdanosti i raspoloţivosti tih sistema, kao smanjenju ukupnih tro&scaron;kova i ekonomiĉnijem poslovanju preduzeća―.</p> / <p>The main objective of this doctoral thesis was to develop a new automated diagnostic model. Then with the practical usage of this model (in particular case of automated diagnostics vital components of technical systems in real operating conditions of different industries) with techno-economic analysis to confirm the main hypothesis of the dissertation: ―Automated diagnostics of technical systems in the industry (based on the use of computers and other modern information and communication technologies) contributes to the increase levels of reliability and availability of these systems, as well as the reduction of total costs and more economical management of the company‖.</p>

L'objectif de cette étude a été de préciser l'implication des processus rhizosphériques dans lesinteractions pour l'acquisition de phosphore (P) entre une céréale et une légumineuse enassociation. Nous avons proposé comme mécanisme de facilitation l'acidification de la rhizosphèredes espèces en association induite par la fixation de N2 de la légumineuse dans le cas de sol neutres àalcalins. Ainsi, l'étude s'est focalisée sur l'influence des changements de pH induits par les racines.Les effets de la disponibilité initiale en P du sol ainsi que de la distance entre les racines des espècesassociées ont également été testés. Les expérimentations ont été menées au champ ainsi qu'enconditions contrôlées. Le blé dur et différentes légumineuses ont été cultivés en culturemonospécifique ou en association sur un même sol pour toutes les expérimentations. Le sol neutreutilisé (Luvisol) présentait trois niveaux contrastés de fertilisation phosphatée et provenait desparcelles d'un essai de longue durée. Nous avons pu démontrer que la manipulation des interactionsrhizosphériques entre une céréale et une légumineuse en association pouvait être optimisée pourpermettre l'augmentation de la disponibilité en P dans la rhizosphère des espèces associées, etencore plus dans le cas de sols présentant une faible valeur initiale de disponibilité. Lescaractéristiques du sol ont eu un rôle clé dans la détermination des processus rhizosphériquesimpliqués. Dans notre cas, les changements de pH induits par les racines ont permis d'augmenter defaçon substantielle la disponibilité en P suite à une acidification, mais aussi à une alcalinisation de larhizosphère. Ainsi la légumineuse, mais aussi la céréale sont susceptibles de faciliter l'acquisition del'espèce associée. Les interactions relatives au pH peuvent influencer la disponibilité en P sur unedistance de plusieurs millimètres et ainsi améliorer l'acquisition de P des plantes à proximité del'espèce facilitatrice.Mots clés : culture associée, facilitation, rhizosphère, disponibilité, phosphore, pH, racine / The aim of the study was to elucidate the implication of rhizospheric processes on plant speciesinteractions for phosphorus (P) acquisition between a cereal and a legume, when intercropped. Weproposed that root-induced acidification of the rhizosphere by the intercropped legume due to N2-fixation as a mechanism of facilitation in neutral to alkaline soils. Thus, the study focused on rootinducedchanges of pH. The effects of initial soil P availability and distance between roots ofintercropped species were also tested. In order to achieve our goals, experiments in the field and incontrolled condition for several cropping devices were conducted. Durum wheat and differentlegumes were grown as sole crops and intercropped on the same soil for all the experiments. Weused a neutral soil (Luvisol) presenting three contrasted fertilization rates from the field of a longtermP fertilizer trial. We demonstrated that cereal-legume can be used to enhance P availability, andeven more so in low P soils, through managing rhizospheric interactions to optimize P acquisition ofintercropped species. Soil characteristics are also a key factor determining the influence of thoserhizospheric processes. In our studied soil root-induced changes of pH substantially enhanced Pavailability in the rhizosphere either through acidification or alkalization. Thus the legume but alsothe cereal may facilitate the acquisition of the intercropped species. Interactions involving pH canaffect P availability over distance of several millimeters and ultimately enhance P acquisition ofplants in the surrounding of the facilitative species.Key words: intercrop, facilitation, rhizosphere, availability, phosphorus, pH, root

Le mercure suscite beaucoup d'attention de par les conséquences sanitaires et environnementales qu'il engendre. Son impact est particulièrement important dans la région amazonienne et en particulier en Guyane française où les teneurs en mercure sont naturellement élevées dans les sols, et s'ajoutent celles liées aux activités d'orpaillage. Si l'impact du mercure dans les milieux aquatiques a été largement étudié, peu d'études ont évalué son impact dans les milieux terrestres, où il est préférentiellement stocké. Dans ce contexte, les interactions entre les vers de terre, organismes ingénieurs des sols, et le mercure ont été étudiées dans des sols tropicaux, avec comme objectifs : i) d'évaluer l'abondance et la diversité des vers de terre in situ en lien avec le mercure, ii) d'évaluer expérimentalement la résistance au mercure d'une espèce de ver tropical présente sur le site d'étude et iii) d'évaluer l'impact en microcosmes de l'activité des vers de terre sur la mobilité et la répartition du mercure dans les sols. Ces objectifs ont été appréhendés au travers de trois volets, avec comme matériel d'étude des sols naturels (oxisols et sols hydromorphes) et des vers de terre tropicaux provenant d'un site orpaillé, situé dans les environs de Cacao, en Guyane française. Dans le premier volet, un échantillonnage standardisé des vers de terre (TSBF), a permis de proposer des espèces putatives (ou MOTUs) à partir de méthodologies de délimitation basées sur le barcode ADN. Ces MOTUs ont ensuite été identifiés morphologiquement, parmi lesquels Pontoscolex corethrurus, une espèce pantropicale considérée comme pérégrine. De plus, les caractéristiques des sols et les teneurs en mercure ont été déterminés afin de tenter d'expliquer la distribution des vers sur le site étudié. P. corethrurus se retrouve exclusivement dans l'oxisol, qui contient les concentrations les plus élevées de mercure total. Le second volet de ce travail a été consacré à l'étude de l'impact du mercure sur l'espèce tropicale P. corethrurus, à travers une approche écotoxicologique où le vers de terre a été exposé à différentes concentrations de mercure dans un oxisol dopé au laboratoire (HgCl2). Les résultats obtenus ont confirmé la résistance de cette espèce à des concentrations de mercure allant jusqu'à 20 µg g-1 de sol et ont révélé sa forte capacité bioaccumulatrice. Les résultats précédemment décrits ont ouvert la voie à un troisième volet où deux études en microcosmes se sont attachées à étudier l'impact des vers de terre sur la mobilité et la disponibilité du mercure (a) dans des conditions proches de celles rencontrées en conditions naturelles (fond géochimique), et (b) en présence d'une forte concentration pouvant être rencontrée sur les sites orpaillés (20 μg Hg g-1 de sol). Les résultats obtenus ont montré que les vers de terre agissent sur la mobilité du mercure directement par modifications physico-chimiques des sols (augmentation du pH et COD) et indirectement par stimulation des communautés bactériennes totales du sol. En conclusion, notre étude a montré que (1) P. corethrurus est une espèce résistante au mercure de par sa présence sur notre site d'étude et les résultats du test écotoxicologique mené au laboratoire, ce qui confirme l'idée d'un modèle tropical pour ce type d'étude ; (2) la bioaccumulation du mercure mesurée chez les vers de terre est importante et pourrait ainsi être responsable de l'entrée du mercure dans la chaîne terrestre trophique ; et (3) les vers de terre jouent un rôle dans la mobilité du mercure, modifiant sa partition dans les sols et diminuant les conséquences environnementales liées à sa biodisponibilité / Mercury is of major concern because of health and environmental problems that they cause. This toxic pollutant is particularly prevalent in tropical Amazonian regions and in French Guiana where soils are naturally rich in mercury and past and present gold mining activities occurred. While many studies have shown the impact of mercury in aquatic environments, to our knowledge only a few have focused on terrestrial ecosystems, where mercury is predominantly found. This doctoral research examined the interactions between earthworms, which are soil engineers, and mercury in a tropical soil from French Guiana. The objectives of the research were to: i) evaluate in situ earthworm diversity and distribution in soils related to mercury concentrations, ii) evaluate experimentally the impact of mercury on a tropical earthworm species present in our study site, and iii) evaluate the impact of earthworms on mercury mobility and availability in different soils. In order to achieve these objectives, three studies were conducted using natural tropical soils (oxisols and hydromorphic soils) and tropical earthworms sampled in a small catchment basin located near Cacao, in French Guiana. In the first part, earthworms were collected in the field using the standard TSBF method, and species delimitation was done based on DNA barcoding. Putative species were then morphologically identified, among them Pontoscolex corethrurus, a pantropical and peregrine species. Furthermore, soil characteristics and mercury concentrations were determined, and a first attempt was made to explain earthworm distribution in the field. P. corethrurus was found only in the oxisol, which contained highest mercury concentrations in the field. In the second part, an ecotoxicological study was done using a natural tropical soil in order to assess the impact of mercury on the identified tropical species: P. corethrurus. The results showed that P. corethrurus can resist up to high mercury concentrations ; it was not affected until 20 µg Hg g-1 soil and showed high capacity of Hg bioaccumulation. These results were used for the third part of the thesis. In the last part, two studies were conducted in controlled conditions in order to assess the impact of earthworms on mercury mobility and availability in soils. For these studies, conditions near natural conditions and also a high mercury concentration were applied to the soil (20 μg Hg g-1 soil). Results showed the impact of earthworm on mercury mobility and availability through different mechanisms: directly, through soil modifications (increase of soil pH and DOC), and indirectly, through stimulation of the soil microbial population. Furthermore, results confirmed the high capacity of earthworms for mercury bioaccumulation. In conclusion, we showed that (1) P. corethrurus is resistant to mercury, due to its presence in our field contaminated site and the results of the toxicity test done in the laboratory, thus confirming the use of a tropical species for these studies ; (2) mercury bioaccumulation measured in earthworms is important and thus could be responsible for its entry and biomagnification in the terrestrial food chain ; and (3) earthworms affect mercury mobility modifying its fractioning in soils and decreasing its availability

The Coast Guard has developed several systems to measure the performance of its engineering and logistics organizations. The development of these measures is based upon the need to show where and how the organization meets the American taxpayer’s needs. The use of multivariable regressions and determining the statistical distributions of the variables will show the adequacy of the measures and processes currently used. They will also determine a better way to measure the performance of the Coast Guard Small Boat Fleet. This research will analyze the 47 Motor Life Boat and 25 Response Boat-Small data from fiscal year 2011 to 2013. The focus will be on improving the measure used by the engineering and systems managers of the Coast Guard to manage assets and resources, as well as making recommendations on how to improve the processes involved in managing a robust engineering and logistics system.

Arsenic (As) appears in the environment as various As species, which may vary in plant uptake and toxicity. Moreover, As exposure may vary between habitat due to availability and speciation, both of which are influenced by redox potential. To decrease As uptake, addition of silicate may be a tool. The aim of the study was to investigate how the external factors As availability, plant habitats, silicon and oxygen level, influenced the accumulation and speciation of As in plants for food and phytoremediation in a temperate region. The external factors were chosen due to their previously showed influence on As in plants. The risks with dietary As was investigated by plant As accumulation and speciation in carrot, lettuce and spinach grown in alum shale and glassworks soils, and by the influence of silicon on As accumulation in lettuce in hydroponics. Suitable plants for As phytoremediation was investigated by analysing plants from various habitats, and by the O2 influence on phytofiltration. The results showed that vegetables accumulated more As in soils with higher As extractability, and the As extractability in the rhizosphere was higher than in bulk soil. Also, the As concentration in lettuce was higher in hydroponics than in soil, but silicon reduced the accumulation of As in lettuce in hydroponics. Also, the more toxic inorganic As were the main As species detected in vegetables, compared with the less toxic organic As. For phytoremediation, the results showed a low As accumulation in emergent and terrestrial plants. Submerged plants had had a higher shoot As concentration. In general, the habitat had a major influence on the As accumulation in plants. The results also showed that the As accumulation properties in Elodea canadensis was reduced at higher O2. In conclusion, consumption of vegetables cultivated in As polluted soils can result in an elevated intake of inorganic As, and E. canadensis is a promising candidate for As phytofiltration in a temperate region. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 2: Manuscript; Paper 4: Manuscript; Paper 5: Manuscript.</p>