Trophic niche and detection of the invasive signal crayfish (Pacifastacus leniusculus) in Scotland

Aquatic invasive species are a major threat to native freshwater biodiversity. The North American signal crayfish Pacifastacus leniusculus was introduced to Great Britain during the 1970s and is now widely distributed throughout England, Wales and Scotland. First recorded in Scotland in 1995, P. leniusculus is now established at more than twenty sites. The only other introduced crayfish species present in Scotland is the white-clawed crayfish Austropotamobius pallipes. A. pallipes is restricted to only two locations in Scotland, Loch Croispol and Whitemoss Reservoir. P. leniusculus negatively impacts macrophytes, invertebrates and fish though ecological and physical processes. Additionally, P. leniusculus has displaced A. pallipes throughout much of its native range within Great Britain due to competition and disease. Consequently, the two A. pallipes populations in Scotland have a high conservation value. This PhD study aimed to improve understanding of P. leniusculus invasion success by examining trophic dynamics and to develop methodologies that could improve the detection and control of P. leniusculus populations in Scotland. Stable isotope analysis was used to determine the diet composition, trophic position and whether an ontogenetic dietary shift occurs in the Loch Ken population of P. leniusculus. Bayesian mixing models indicated that P. leniusculus in Loch Ken do exhibit an ontogenetic dietary shift. Additionally, individuals of all sizes occupied the trophic position of a predator in Loch Ken suggesting that invertebrates and fish constitute an important component of P. leniusculus diet. Stable isotope analysis was used once again to compare the isotopic niche width and diet composition of P. leniusculus populations from Loch Ken and A. pallipes populations from Loch Croispol and Whitemoss Reservoir. At the species level, A. pallipes exhibited a larger niche width than that of P. leniusculus. At the population level, the isotopic signatures of the A. pallipes populations were considerably different from each other suggesting an overestimation of A. pallipes’ niche width at species level. Results showed no dietary overlap between species and Bayesian mixing models suggested P. leniusculus and A. pallipes were consuming different resources, indicating there would be no direct competition for food resources if they were to co-occur. A plus-maze study was used to determine if P. leniusculus exhibited a preference for one of four food attractants (Oncorhynchus mykiss, P. leniusculus, beef or vegetation), which could be used to improve trapping efficiency. In the maze system, P. leniusculus exhibited no preference for any food attractant presented. This would suggest that either the maze was not a good model or food attractants would not improve trapping efficiency of P. leniusculus. Additionally, a comparative investigation into the use of gill nets as a method to control P. leniusculus was conducted. Results showed that the net type and the presence of fish entangled in the net influenced the number of P. leniusculus caught. Finally, environmental DNA (eDNA) was used and evaluated for detection of P. leniusculus. A robust quantitative Polymerase Chain Reaction (qPCR) assay and DNA extraction protocol were developed. Using the developed qPCR assay, P. leniusculus eDNA was detected in controlled aquaria conditions but not in environmental water samples collected from the field. Furthermore, the quantities of P. leniusculus eDNA declined in aquaria conditions while individuals were still present suggesting the mechanisms for eDNA release by P. leniusculus are complex. Stable isotope analysis indicates that P. leniusculus exhibit an ontogenetic dietary shift, and in each life stage, P. leniusculus function as an omnivore but occupy the trophic position of a predator. Niche width analysis revealed that the diet of P. leniusculus was less general than that observed in A. pallipes and thus diet of P. leniusculus may not be responsible for invasive success. Food attractants will not enhance trapping efficiency but nets may present a potential new method to control P. leniusculus. Similarly, eDNA presents a promising new method for rapid detection of P. leniusculus. It will not be possible to eradicate P. leniusculus in Scotland but the findings of this PhD may help prevent establishment of new populations. These results should be incorporated into future management strategies for P. leniusculus populations in Scotland and may have broader applications in Great Britain and Europe

Oxygen, pH, and labile organic carbon as possible mechanisms for algal stimulation of bacterial and fungal production in periphyton

Algal photosynthesis can stimulate production of associated microbial heterotrophs; however,the mechanisms for this stimulation remain unknown. I incubated submerged Typha domingensis leaf litter in greenhouse mesocosms under low- and high-nutrient regimes and conducted microbial production assays after 79/80 (week 11) or 128/129 (week 18) days of colonization. I manipulated environmental factors (oxygen, pH, and labile organic carbon) affected by algal photosynthesis to test the hypothesis that one or more of these factors stimulates heterotrophic microbial production. In the low-nutrient treatments, bacterial production was increased by glucose addition during week 11 (p \u3c 0.001) and by photosynthesis during week 18 (p \u3c 0.05). Fungal production was stimulated by photosynthesis in the high-nutrient treatments during weeks 11 (p \u3c 0.001) and 18 (p \u3c 0.01) and by glucose during week 11 (p \u3c 0.05). These results confirm that algal photosynthesis can increase heterotrophic microbial production and suggest that photosynthetic labile organic carbon (LOC) could be a stimulatory mechanism

Functional Imaging of Autonomic Regulation: Methods and Key Findings.

Central nervous system processing of autonomic function involves a network of regions throughout the brain which can be visualized and measured with neuroimaging techniques, notably functional magnetic resonance imaging (fMRI). The development of fMRI procedures has both confirmed and extended earlier findings from animal models, and human stroke and lesion studies. Assessments with fMRI can elucidate interactions between different central sites in regulating normal autonomic patterning, and demonstrate how disturbed systems can interact to produce aberrant regulation during autonomic challenges. Understanding autonomic dysfunction in various illnesses reveals mechanisms that potentially lead to interventions in the impairments. The objectives here are to: (1) describe the fMRI neuroimaging methodology for assessment of autonomic neural control, (2) outline the widespread, lateralized distribution of function in autonomic sites in the normal brain which includes structures from the neocortex through the medulla and cerebellum, (3) illustrate the importance of the time course of neural changes when coordinating responses, and how those patterns are impacted in conditions of sleep-disordered breathing, and (4) highlight opportunities for future research studies with emerging methodologies. Methodological considerations specific to autonomic testing include timing of challenges relative to the underlying fMRI signal, spatial resolution sufficient to identify autonomic brainstem nuclei, blood pressure, and blood oxygenation influences on the fMRI signal, and the sustained timing, often measured in minutes of challenge periods and recovery. Key findings include the lateralized nature of autonomic organization, which is reminiscent of asymmetric motor, sensory, and language pathways. Testing brain function during autonomic challenges demonstrate closely-integrated timing of responses in connected brain areas during autonomic challenges, and the involvement with brain regions mediating postural and motoric actions, including respiration, and cardiac output. The study of pathological processes associated with autonomic disruption shows susceptibilities of different brain structures to altered timing of neural function, notably in sleep disordered breathing, such as obstructive sleep apnea and congenital central hypoventilation syndrome. The cerebellum, in particular, serves coordination roles for vestibular stimuli and blood pressure changes, and shows both injury and substantially altered timing of responses to pressor challenges in sleep-disordered breathing conditions. The insights into central autonomic processing provided by neuroimaging have assisted understanding of such regulation, and may lead to new treatment options for conditions with disrupted autonomic function

Developing New Methods to Quantify Stress in Wildlife Using Liquid Chromatography Tandem Mass Spectrometry

Stress levels in wildlife species are an accurate indicator of an animal’s well-being and can reflect decreases in habitat quality. Stress levels can be measured by the presence of the stress response hormones cortisol, cortisone, and corticosterone. Analysis of these stress hormones in fecal samples has been widely used because feces can be easily obtained and non-invasively collected in the field. Methods of detecting stress levels from fecal samples of wildlife species are currently limited to enzyme immunoassay testing. This method uses antibodies to bind to target stress hormones. However, immunoassay testing can be time consuming and very expensive2. We propose that Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) offers a new method to quantify levels of the stress hormones from fecal samples that is less expensive and time consuming than traditional immunoassays1. As part of the Idaho Science Talent Expansion Program (STEP), we are developing a simple, accurate, and relatively inexpensive method to detect stress hormones in fecal samples from free-ranging pygmy rabbits (Brachylagus idahoensis) and sage grouse (Centrocercus urophasianus) using LC-MS/MS

Securing Equal Access to Sex-segregated Facilities for Transgender Students

If Title IX is to have any real meaning for transgender students, it must protect a student\u27s ability to live and participate in school as a member of the gender with which they identify. This means that students must be permitted to use gender-segregated spaces, including restrooms and locker rooms, consistent with their gender identity, without restriction. Denial of equal access to facilities that correspond to a student\u27s gender identity singles out and stigmatizes transgender students, inflicts humiliation and trauma, interferes with medical treatment, and empowers bullies. A student subjected to these conditions is, by definition, deprived of an equal opportunity to learn because of his or her transgender status, and therefore, because of his or her sex. Arguments against equal access reflect broader animus and stereotypes about transgender people, and rely on justifications that have been rejected by courts in related contexts. Access consistent with a student\u27s gender identity is widely practiced, and is the only workable and nondiscriminatory approach that is consistent with Title IX\u27s requirement of equal educational opportunity

Derivation of Economic and Social Indicators for a Spatial Decision Support System to Evaluate the Impacts of Urban Development on Water Bodies in New Zealand

There is mounting evidence that urban development in New Zealand has contributed to poor water quality and ecological degradation of coastal and fresh water receiving waters. As a consequence, local governments have identified the need for improved methods to guide decision making to achieve improved outcomes for those receiving waters. This paper reports progress on a research programme to develop a catchmentscale spatial decision-support system (SDSS) that will aid evaluation of the impacts of urban development on attributes such as water and sediment quality; ecosystem health; and economic, social and cultural values. The SDSS aims to express indicators of impacts on these values within a sustainability indexing system in order to allow local governments to consider them holistically over planning timeframes of several decades. The SDSS will use a combination of deterministic and probabilistic methods to, firstly, estimate changes to environmental stressors such as contaminant loads from different land use and stormwater management scenarios and, secondly, use these results and information from a range of other sources to generate indicator values. This paper describes the project’s approach to the derivation of indicators of economic and social well being associated with the effects of urban storm water run-off on freshwater and estuarine receiving waters.Environmental Economics and Policy,

National strategy for health research and innovation

In 2011, the Malta Council for Science and Technology (MCST) commissioned the Development of a dedicated strategy for health research and innovation in line with its mandate from Government to identify areas of national priority and design and to also implement strategic approaches to enhance economic competitiveness and quality of life. The Strategy was drawn up by a steering group which also included people from outside the health sector, to ensure that it also keeps note of the economic side of things.peer-reviewe