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.

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.

The significance of risk is growing in many Western societies, a phenomenon linked to increasing individualism, personal choice, and outcome uncertainty in multiple spheres of life. Despite being healthier and more physically protected from harm than any previous society, a serious concern for safety and risk control is emerging as a defining characteristic of modern social life. Within the context of a risk-averse society, this thesis investigates the nature and relevance of risk in natural resource recreation and tourism settings. Millions of people every day visit national parks and other protected areas around the world in which natural hazards inhere. Many visitors fail to recognise these hazards, creating moral, legal, and ethical issues for natural resource managers. People travel to national parks anticipating a degree of adventure, to escape routines, and to witness the grandeur of nature. Ironically, the very qualities that attract people to natural areas may also put them at risk. Managers of natural resource tourism and recreation areas in New Zealand are confronted with a paradox born out of visitor demand for nature experiences, a legal obligation to facilitate free access, and a growing social emphasis on health and safety. In particular, this study assesses the risk perceptions of visitors to the Fox and Franz Josef glaciers, popular tourist attractions on the West Coast of New Zealand's South Island, and explores the risk perceptions and beliefs of resource management agency staff. The study also investigates the issue of risk communication at these two sites, and the degree to which existing hazard messages are successful at encouraging appropriate visitor behaviour. Pictorial hazard warning signs are introduced to the sites and their effectiveness evaluated. The findings show that many visitors (especially international visitors) have relatively poor awareness of natural hazards, and behave in ways which potentially compromise physical safety. It is argued that perceptions and behaviour are a consequence of diverse individual and situational factors including limited knowledge of the sites, beliefs about management, poor comprehension of hazard warning signs, and freedom from the normative constraints of everyday life. In contrast to visitors, managers at the glacier sites consider the risks to be significant, and, potentially, severe. It is argued that managers' perceptions of risk are influenced by several important social and site-specific factors, including their own experiences of hazards at the glaciers, perceived legal and moral obligations, the organisational culture, and impressions of high societal expectation concerning safety. The situation is further complicated by the freedom of access principle in national parks, and increasing tourist demand for nature-based experiences. These factors governed beliefs about the subject of risk. This study identifies several dimensions of risk in nature-based recreation and tourism settings. Visitors are at risk of personal accident or injury at certain tourism attractions. Awareness of hazards is limited, visitor behaviour compromises safety, and existing communication strategies are only partially effective. Risk is also apparent in the agency responsible for management of outdoor recreation areas. Site managers perceive a risk in their failure to prevent visitors from harm, whereas senior managers identify risk as primarily financial, legal, and political. Collectively, these factors demonstrate that the phenomenon of risk is increasingly important in the tourism and recreation context, and has the potential to influence significantly both management and experience of protected natural areas in New Zealand.

The land-grant university system was founded in the 19th century as a public means to help improve people’s everyday lives. A century and a half later, the challenges that the public faces to live a quality life are constantly changing, creating a need for the land-grant system to respond and adapt to continue to fulfill its mission. While the literature contains a wealth of conceptual papers addressing the role and mission of land-grant universities, relatively few papers could be found that reported empirical data or proposed and tested metrics for public engagement constructs. The current study sought to address this void in the literature through the investigation of factors influencing Indiana residents’ level of interest in engaging with Purdue University. Mail survey methods were used in which up to three contacts were made with adult members of 4,500 Indiana households identified through address-based sampling. Stratified random sampling was employed to ensure adequate rural household participation for other project purposes. Usable responses were received from 1,003 households representing 87 Indiana counties for a total response rate of 26%. <br><div><br> </div><div> A theoretical perspective was developed from Public Sphere Theory and the social science writings of Jurgen Habermas and Alexis de Tocqueville. Descriptive findings revealed some to moderate concerns about community and social issues such as affordable health care, violent crime, pollution and prescription drug abuse. Moderate levels of anomie, or perceived social disconnectedness, were also reported by respondents. Several items tapped respondents’ past levels of interaction with and current perceptions of Purdue University. Nearly a fifth of respondents reported interacting with Purdue University by having visited a website for news or information, followed by interacting with a Purdue University Extension professional. Regarding perceptions of Purdue University, the results of this study revealed relative consensus among respondents that Purdue University makes a positive contribution to the state of Indiana through its educational, research and outreach programs. For a majority of the perceptual items regarding Purdue University, more than one-third of the respondents neither agreed nor disagreed with the statement, suggesting some areas in which the university might improve its reputational standing with Indiana residents in the future. Nearly one-quarter to about half of the respondents indicated interest in topical areas addressed by Purdue Extension programs as well as an interest in engaging with the university. Respondents reported the highest levels of interest in free Extension programs in their local area, followed by the topics of science and technology, health and well-being, and gardening.</div><div><br> </div><div> A predictive model of respondent interest in engaging with Purdue University was developed and tested using binary logistic regression procedures. The model was shown to be of modest utility in accounting for variance in respondent interest in engaging with Purdue University, explaining 12% to 16% of total variance. Past interaction with Purdue University, perceived level of concern for social and community issues, and highest level of education were the strongest predictors in the model.</div><div><br> </div><div> The current research was completed in 2019 as Purdue University celebrated its 150th anniversary. Results and implications of this study provide important insight into current engagement levels, concerns and perceptions of residents within the state of Indiana, whom the university is mandated to serve. One of the study’s primary contributions is the establishment of baseline engagement data on current levels of Indiana residents’ interest in engaging with Purdue University on selected topics. Findings from this study could be of benefit to university administrators, faculty, staff and Extension professionals in assessing and improving future programming and setting strategic priorities. This study also adds to the conceptual and empirical body of literature, which may help inform future public engagement efforts at other land-grant universities. Periodic social science and public opinion research is needed to keep pace with the changing needs and perceptions of Indiana residents. Different data collection modes should be utilized to reach more audience segments and add to the growing knowledge base of public engagement.</div>