Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms (the latter probably related to ingestion of water) are most frequently reported. Some papers give convincing descriptions of allergic responses to cyanobacteria; others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A U.S. coroner recently found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond; this is the first recorded human fatality attributed to recreational exposure to cyanobacteria. One of the main public health concerns with exposure to freshwater cyanobacteria relates to the understanding that some blooms produce toxins that specifically affect the liver or the central nervous system. The route of exposure for these toxins is oral, from accidental or deliberate ingestion of recreational water, and possibly by inhalation. Cyanobacterial lipopolysaccharides (LPS) are also reported to be putative cutaneous, gastrointestinal, respiratory and pyrogenic toxins. The aims of this project were to enhance the understanding of public health issues relating to recreational exposure to cyanobacteria by conducting epidemiological and laboratory-based toxicology studies. A prospective cohort study of 1,331 recreational water users was conducted at various sites in southern Queensland, the Myall Lakes area of New South Wales, and central Florida. The study design sought to make improvements over previously published epidemiological studies, in that an unexposed group was recruited from cyanobacteria-free waters, cyanobacterial toxins were measured in site water samples, and respondents were asked to rate the severity of reported symptoms. This study has shown an increased likelihood of symptom reporting amongst bathers exposed to high cyanobacterial cell density (measured by total cell surface area) compared to those exposed to low cyanobacteria-affected waters. Mild respiratory symptoms appear to be the predominant symptom category. A clinical dermatology study to examine delayed-contact hypersensitivity reactions to cyanobacterial extracts was conducted. The study groups were 20 patients presenting for diagnostic skin patch testing at the Royal Brisbane Hospital's dermatology outpatient clinic; a convenience sample of 20 individuals was recruited from outside the hospital as a control group. One patient developed unequivocal reactions to several cyanobacteria extracts, with no dose-response pattern seen, indicating that the reactions were allergic in nature. A mouse model of delayed-contact hypersensitivity, the mouse ear swelling test, has demonstrated that the purified toxin cylindrospermopsin, a highly water-soluble compound, is capable of producing cutaneous injury. Encrusting lesions were seen on abdominal skin during the induction phase of these experiments. Delayed-contact hypersensitivity reactions were also demonstrated with this toxin. LPS from two non-axenic cyanobacterial samples - Cylindrospermopsis raciborskii and Microcystis aeruginosa - were extracted and purified. Thermoregulation studies were performed using a mouse model of rectal temperature measurement. Separate groups of mice were injected with these LPS extracts at two dose levels. Thermoregulation studies were also conducted with purified cyanobacterial toxins: microcystin-LR and cylindrospermopsin and anatoxin-a; cyanobacterial LPS samples purified by collaborators in Adelaide were also investigated for thermoregulation potential. These experiments have shown that the LPS extracts are weakly active when compared with responses to much lower doses of Escherichia coli LPS. Cylindrospermopsin also produces hypothermic responses in mice - comparable to pyrexia in larger mammals - although at a later stage than was seen with LPS extracts. Supplementing the experimental observations of the toxicology and immunotoxicology of cyanobacterial LPS are insights gained from beyond the cyanobacteria literature on the mechanisms of toxicity of different LPS structures. Cyanobacterial LPS was initially suggested to be toxic in the 1970s, at a time when lipid A, the active moiety of LPS, was thought to be identical across all Gram-negative bacteria. More recent work raises questions about the attribution of cutaneous and gastrointestinal illness to cyanobacterial LPS, with the understanding that some bacterial lipid A structures are LPS antagonists, LPS is not toxic by the oral route, and LPS is not reported as a toxin in the clinical dermatology literature. Gut-derived lipopolysaccharides, however, exert potent synergistic effects with a variety of xenobiotic hepatotoxins, and the well-known shock-like syndromes associated with severe cylindrospermopsin and microcystin poisoning deserve further scrutiny from the perspective of immunotoxicology.

Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms (the latter probably related to ingestion of water) are most frequently reported. Some papers give convincing descriptions of allergic responses to cyanobacteria; others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A U.S. coroner recently found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond; this is the first recorded human fatality attributed to recreational exposure to cyanobacteria. One of the main public health concerns with exposure to freshwater cyanobacteria relates to the understanding that some blooms produce toxins that specifically affect the liver or the central nervous system. The route of exposure for these toxins is oral, from accidental or deliberate ingestion of recreational water, and possibly by inhalation. Cyanobacterial lipopolysaccharides (LPS) are also reported to be putative cutaneous, gastrointestinal, respiratory and pyrogenic toxins. The aims of this project were to enhance the understanding of public health issues relating to recreational exposure to cyanobacteria by conducting epidemiological and laboratory-based toxicology studies. A prospective cohort study of 1,331 recreational water users was conducted at various sites in southern Queensland, the Myall Lakes area of New South Wales, and central Florida. The study design sought to make improvements over previously published epidemiological studies, in that an unexposed group was recruited from cyanobacteria-free waters, cyanobacterial toxins were measured in site water samples, and respondents were asked to rate the severity of reported symptoms. This study has shown an increased likelihood of symptom reporting amongst bathers exposed to high cyanobacterial cell density (measured by total cell surface area) compared to those exposed to low cyanobacteria-affected waters. Mild respiratory symptoms appear to be the predominant symptom category. A clinical dermatology study to examine delayed-contact hypersensitivity reactions to cyanobacterial extracts was conducted. The study groups were 20 patients presenting for diagnostic skin patch testing at the Royal Brisbane Hospital's dermatology outpatient clinic; a convenience sample of 20 individuals was recruited from outside the hospital as a control group. One patient developed unequivocal reactions to several cyanobacteria extracts, with no dose-response pattern seen, indicating that the reactions were allergic in nature. A mouse model of delayed-contact hypersensitivity, the mouse ear swelling test, has demonstrated that the purified toxin cylindrospermopsin, a highly water-soluble compound, is capable of producing cutaneous injury. Encrusting lesions were seen on abdominal skin during the induction phase of these experiments. Delayed-contact hypersensitivity reactions were also demonstrated with this toxin. LPS from two non-axenic cyanobacterial samples - Cylindrospermopsis raciborskii and Microcystis aeruginosa - were extracted and purified. Thermoregulation studies were performed using a mouse model of rectal temperature measurement. Separate groups of mice were injected with these LPS extracts at two dose levels. Thermoregulation studies were also conducted with purified cyanobacterial toxins: microcystin-LR and cylindrospermopsin and anatoxin-a; cyanobacterial LPS samples purified by collaborators in Adelaide were also investigated for thermoregulation potential. These experiments have shown that the LPS extracts are weakly active when compared with responses to much lower doses of Escherichia coli LPS. Cylindrospermopsin also produces hypothermic responses in mice - comparable to pyrexia in larger mammals - although at a later stage than was seen with LPS extracts. Supplementing the experimental observations of the toxicology and immunotoxicology of cyanobacterial LPS are insights gained from beyond the cyanobacteria literature on the mechanisms of toxicity of different LPS structures. Cyanobacterial LPS was initially suggested to be toxic in the 1970s, at a time when lipid A, the active moiety of LPS, was thought to be identical across all Gram-negative bacteria. More recent work raises questions about the attribution of cutaneous and gastrointestinal illness to cyanobacterial LPS, with the understanding that some bacterial lipid A structures are LPS antagonists, LPS is not toxic by the oral route, and LPS is not reported as a toxin in the clinical dermatology literature. Gut-derived lipopolysaccharides, however, exert potent synergistic effects with a variety of xenobiotic hepatotoxins, and the well-known shock-like syndromes associated with severe cylindrospermopsin and microcystin poisoning deserve further scrutiny from the perspective of immunotoxicology.

Why do temporary foreign workers employed in the British Columbia hospitality sector have difficulty enforcing their workplace rights? Using the themes of people, place and time, this thesis explores the demand and supply of migrant workers in the British Columbia hospitality sector, and the challenges temporary foreign workers face at the intersection of immigration law, employment law, occupational health and safety law, and workers’ compensation law. The thesis argues that the low-skilled Temporary Foreign Worker Program shifts the negative consequences of unfair working conditions and workplace health and safety risks over people, place and time: from Canadian workers and employers onto temporary foreign workers; from Canada to elsewhere; and from the present into the future. Workplace rights are not enough for hospitality sector workers, what is needed is better tools for the enforcement of those rights. / Graduate

La conscience se définit comme la connaissance que chacun a de son existence et de celle du monde extérieur. Par extension, elle correspond à la représentation mentale claire qu'un individu peut se faire de la réalité d'une situation. Lorsque le monde extérieur prend les traits de l'environnement de travail et que les situations à appréhender relèvent de l'exécution du contrat y afférent, quelle peut être l'influence de la conscience ? Existe-t-il des limites quant à sa compatibilité avec l'accomplissement du travail ou avec le bon déroulement des relations sociales ? Cette thèse a pour objectif l'étude des différents "cas de conscience" au sein de l'entreprise, à travers le point de vue des différents acteurs concernés - employeurs, salariés, organisations syndicales et représentants du personnel, autorités administratives et organismes de protection sociale. Il s'agit de comprendre dans quelles types de situation la conscience, sous sa forme individuelle comme collective, a la possibilité de s'exprimer, voire de jouer un rôle. En outre, il convient de s'interroger sur l'appréhension - ou la non-appréhension - de ces manifestations de la conscience par le droit social interne, international et comparé. Si les contours de certaines occurrences de la conscience sont a priori cernés, à l'image notamment des droits d'alerte ou des clauses éponymes insérées parfois dans les contrats, l'encadrement d'autres déclinaisons, sans doute plus sensibles, demeure encore à construire. / Consciousness can be defined as the knowledge of one’s existence and the outer world. By extension, it is someone’s clear mental picture of an actual situation and the ability of judging the morality of such a situation is called conscience. When the outer world is the work environment and when the actual situations to deal with are work-related, what could be the role of consciousness and conscience? Could they interfere with work duties or the conduct of good industrial relations? The purpose of this thesis is to study the “issues of conscience” within the corporation, in a broad sense, through the relevant stakeholders’ perspectives – including employers, administrative authorities, workers, trade unions, or even staff representatives – in order to know when individual and collective consciousness and conscience can have a legal impact. One should ask oneself about the existence of a statutory regime for those “issues of conscience” in domestic, comparative and international laws. Some manifestations of consciousness and conscience are already well known, such as whistleblowing or conscience clauses, but some others still need to be provided with a legal framework.

Confronté, dans les entreprises de grande taille, à l’impossibilité d’exercer lui-même la totalité de ses pouvoirs, le chef d’entreprise est conduit à en déléguer à des préposés. Cette transmission du pouvoir participe de l’organisation de l’entreprise. La délégation de pouvoir en constitue le vecteur le plus pertinent. La flexibilité de son régime incite à y recourir dans l’entreprise voire dans le périmètre d’un groupe. Le transfert de pouvoir a pour corollaire un transfert de responsabilité, y compris, sous certaines conditions, de responsabilité à la charge du délégataire.La délégation de pouvoir s’impose aujourd’hui comme un des outils privilégiés d’organisation de l’entreprise d’autant qu’elle permet, face à la forte pénalisation des relations de travail, une répartition des risques entre ses acteurs. Elle permet au chef d’entreprise, destinataire de multiples obligations légales, d’opérer une déconcentration du pouvoir et de la responsabilité qui l’accompagne en confiant à des salariés dotés des compétences requises la réalisation de tâches qu’il n’est pas, en pratique, en mesure d’assumer. Son action y gagne en efficacité, dans l’intérêt de tous. / Faced with the impossibility of exercising his or her full powers in a large company, the executive director has to delegate some these to his or her subordinates. Transmission of power therefore becomes part of the organisation of the company and constitutes the most pertinent vector of said organisation. The flexibility of its regime is an incentive to use delegation in the company or even in the scope of the corporate group. The transfer of responsibility becomes a corollary of the transfer of power, including, under certain conditions, the transfer of responsability borne by the delegator. Delegation of power has become one of the preferred tools in the organisation of a company as it also allows for the distribution of risks amongst its actors in the face of the current strong penalisation of work relations. It allows the executive director, the bearer of multiple legal obligations, to carry out a deconcentration of power and stemming from that, of responsibility, by giving employees possessing the required skills the tasks that he or she isn’t, in practice, able to undertake. His or her action increases efficiency in the interest of all.

Les grands groupes de l'industrie de la construction souhaitent intégrer le concept de prévention au sein de leurs organisations en recherchant des améliorations techniques et organisationnelles et en déployant des méthodes tantôt coercitives, tantôt participatives visant une maîtrise du facteur humain. L'objectif de cette industrie est de contrôler les risques inhérents aux chantiers dont il est possible de déterminer plusieurs classifications. Le point commun de ces dernières est leur finalité, c'est-à-dire établir une liste exhaustive d'un ensemble infini selon des critères variables. Après avoir analysé les différents facteurs influençant sur la genèse des risques dans un environnement aussi particulier qu'est celui des chantiers de bâtiment, nous proposons un modèle dynamique d'appréhension des risques et d'aide à la décision reposant sur la mobilisation de la TNI et de la théorie des représentations sociales. Plus spécifiquement, en considérant les propriétés des risques « émergents » actuels, nous nous interrogeons sur la pertinence des moyens mis en œuvre par l'organisation pour permettre leur intégration. / The major companies of the construction industry wish to integrate the concept of prevention within their organizations by seeking technical and organizational improvements and by implementing coercive or participatory methods whose goal is to deal with the human factor. This industry aims at controlling the risks inherent to the construction sites of which several classifications can be determined. Those classifications have in common their purpose, which is to draw up an exhaustive list from an infinite set according to variable criteria. After analyzing the different factors that influence the genesis of the risks in such a specific environment as the building sites, we propose a dynamic model for risk understanding and decision-making, based on the mobilization of the TNI and the Theory of social representations More specifically, considering the characteristics of the current emerging risks, we wonder about the relevance of the means implemented by the organization towards their integration.

The thesis, entitled "Analysis of safety in transport and servicing of transport facilities for the selected companies" deals with safety and work-related injuries in transportation and servicing of transport facilities. Occupational injury is caused by a set of several interacting factors. These factors are known as the main source and cause of work-related accidents, which affect the formation of accidents. The most important element in the protection of health and safety is prevention. To evaluate the risks is one of the fundamental principles of the concept of occupational health and safety policy that is enforced in all countries espousing the principles of safe enterprise. The need to protect the health of the individual is already firmly established even in the most basic legal document such as the Constitution of the Czech Republic. The aim of this work is to analyze the factors that are involved in causing accidents at work and on the basis of the analysis, to provide rules and recommendations for farms so that they serve as an aid in the elimination of induced injuries.

Theoretical background Employment in the health service brings about a number of risks that are specific of respective health facilities and their departments. Nurses should be informed about all possible risks resulting from their nursing practice, as well as about ways to eliminate these risks because this is the only way they can protect themselves and by suitable means and procedures. Performing their work, nurses are exposed to four main areas of risk factors. These concern especially the effects of mental and physical strain, chemicals and biological factors. Objective of my thesis The objective was to test nurses' knowledge of risks and to test how well they can eliminate these risks. Apart from that, the thesis endeavours to find out whether the risks in nurses' work change in relation to the field of care provided. Hypotheses H1 Nurses know the risks resulting from their nursing practice. H2 Risks in nurses' work vary in relation to the field of care. H3 The most common risk occurring in nurses' occupation is the puncture wound caused by a needle. H 4 Nurses are acquainted with manners to eliminate risks resulting from the performance of their occupation. Methodology To test nurses' knowledge, I compiled a questionnaire focused on surveying the knowledge in the field of risks and elimination of these risks. The questionnaire was arranged in two basic groups. The first group was focused on the knowledge of risks and occurring injury in the performance of the occupation (the puncture wound by a needle). The other group was focused on the area of eliminating the risks. The research was carried out in medical facilities in the Region of South Bohemia. Altogether, 417 nurses were addressed. The following sections were chosen in a haphazard fashion: pulmonary, surgical, internal and a neurological departments, department of subsequent care and the intensive care unit. All the results obtained were statistically processed in the Excel programme from the Microsoft Office software packet. I used a graphic depiction to interpret the outcomes. Outcomes It was found out in the first area of the outcomes that nurses are acquainted with the risks of their occupation (knowledge of risk behaviour, when handling loads, when working with chemicals, when handling oxygen cylinders, treating an aggressive client). The second area of the outcomes was essential for establishing the ways to eliminate risks (the nurses proved knowledge of risks and duties, the duty to participate in creating a safe environment , compulsory preventive medical examinations, knowledge of risk behaviour, using personal protective equipment, observing the work principles and procedures, knowledge of treating contaminated laundry, oxygen cylinders and immobile clients, disinfection of hands, treating an aggressive client). The third area yielded an answer to the question whether puncture wounds caused by needles ranked among the most frequent risks in the occupation of the nurse. The last area was essential to establish the variability of risks depending on the field of care provided. It was found out, that risks varied in relation to the field of care provided, while the nurses viewed the mental and physical strain as the most significant risk in the performance of their work. H1 - Nurses know the risks resulting from their nursing practice - was confirmed, H2 - Risks in nurses' work vary in relation to the field of care provided - was confirmed, H3 - The most common risk occurring in nurses' occupation is the puncture wound by a needle - was confirmed, H4 - Nurses know ways to eliminate risks resulting from the performance of their occupation - was confirmed. Conclusion The outcomes of the research realized will be given to the managements of the above medical facilities, with the aim of increasing the nurses' knowledge of possible risks occurring in the performance of their work, as well as possible ways of eliminating these risks.

Head stabilisation during gait related tasks is thought to be fundamental to whole body stability, but this has received little attention in the older population. There is a need to examine any age related changes in neuromechanical mechanisms underpinning head stabilisation that may challenge the control of head stability, and consequently whole body stability. The present Thesis examined the mechanisms contributing to head stabilisation, and whole body stability during two gait tasks, steady state gait and gait initiation in young and older females, with the overall aim of contributing to negating fall risk. Four studies were designed to examine a) head position and walking speed on gait stability during steady state gait; b) neuromechanical mechanisms underpinning head stabilisation during gait initiation; c) head position on whole body stability during gait initiation; and d) head stabilisation during gait initiation at different speeds. Results showed that a) gait stability, was unaffected by head position and different walking speeds during steady state gait, b) decreased head stability in older individuals during gait initiation can be attributed to a deterioration of the neuromechanical mechanisms relating to head stability, c) free head movement during gait initiation does not affect head stabilisation or whole body stability but it does affect gait parameters, while d) initiating gait at faster than comfortable speeds compromises head stabilisation and reduces whole body stability in older individuals. Collectively, these results demonstrate that older individuals adopt an increased head flexion position when walking, while impaired head stability can be attributed to deterioration of the function of their neuromechanical mechanisms compared to their younger counterparts during gait tasks at comfortable speeds. These findings provide an understanding of the effect head stabilisation can have on older adults’ gait and on their fall risk during gait and gait initiation.

Eye movements are used day-to-day to acquire visual information. Vision is also used for postural control. There are growing indications eye movements can affect postural control. However, this has not been investigated in older adults, which is surprising given the high incidence of falls in older populations. The present thesis aims to address this. The first experimental chapter explores the effects of eye movements on balance during standing in young and older adults. The findings show decreased stability during smooth pursuits, whereas saccades maintained stability to that when fixating a static target. The older adults matched the younger groups performance throughout. The second experimental chapter explores the effects of smooth pursuits and saccades on balance during locomotion in young and older adults. Smooth pursuits were shown to decrease stability, whilst saccades maintained stability compared to fixating a static target. The effects of the eye movements were similar in the older adults. However, the elders exhibited lower baseline stability. The third experimental chapter explores the effects of tracking a real-world stimulus (another person known as `pedestrian') on balance control during locomotion. The pedestrian could be standing still or walking. Fixating the stationary and the walking pedestrian decreased stability similarly when compared to free gaze when the pedestrian was not present. To determine whether these results were transferable to natural gaze rather than instructed gaze, the fourth experimental chapter explores free gaze patterns in a similar real-world environment. Both the young and older adults typically fixated the pedestrian when he was standing still and walking, but began to ignore him once he had walked away from their direction heading. Therefore, experiment 3 behaviour was transferable to natural gaze patterns. The older adults also adopted a more cautious approach by fixating regions on the ground initially, and for longer, before looking to their direction heading.