Alien Registration- Cameron, Angus (Bangor, Penobscot County)

https://digitalmaine.com/alien_docs/15966/thumbnail.jp

Global sensitivity analysis of an end-to-end marine ecosystem model of the North Sea : factors affecting the biomass of fish and benthos

Comprehensive analysis of parameter and driver sensitivity is key to establishing the credibility of models of complex systems. This is especially so for models of natural systems where experimental manipulation of the real-world to provide controlled validation data is not possible. Models of marine ecosystems fall into this category, but despite the interest in these models for evaluating the effects of climate change and fishing on nutrient fluxes and the abundances of flora and fauna, none have yet been subjected to global sensitivity analysis. Here we present results of both local ‘one-at-a-time’ (OAT), and variance based global sensitivity analyses (GSA) of the fish and fishery aspects of StrathE2E, an end-to-end (nutrients to birds and mammals) ecosystem model of the North Sea. The sensitivity of the model was examined with respect to internal biological parameters, and external drivers related to climate and human activity. The OAT Morris method was first used to screen for factors most influential on model outputs. The Sobol GSA method was then used to calculate quantitative sensitivity indices. The results indicated that the fish and shellfish components of the model (demersal and pelagic fish, filter/deposit and scavenge/carnivore feeding benthos) were influenced by different sets of factors. Harvesting rates were directly influential on demersal and pelagic fish biomasses. Suspension/deposit feeding benthos were directly sensitive to changes in temperature, while the temperature acted indirectly on pelagic fish through the connectivity between model components of the food web. Biomass conversion efficiency was the most important factor for scavenge/carnivorous feeding benthos. The results indicate the primacy of fishing as the most important process affecting total fish biomass, together with varying responses to environmental factors which may be relevant in the context of climate change. The non-linear responses and parameter interactions identified by the analysis also highlight the necessity to use global rather than local methods for the sensitivity analysis of ecosystem models

Survey Toolbox for Aquatic Animal Diseases: A Practical Manual and Software Package

Livestock Production/Industries,

A comparison of medetomidine and its active enantiomer dexmedetomidine when administered with ketamine in mice

Medetomidine-ketamine (MK) and dexmedetomidine-ketamine (DK) are widely used to provide general anaesthesia in laboratory animals, but have not been compared directly in many of these species, including rodents. This study aimed to compare the onset and depth of anaesthesia, and changes in vital signs, after intraperitoneal (IP) or subcutaneous (SC) administration of ketamine (75 mg kg-1) combined with medetomidine (1 mg kg-1) or dexmedetomidine (0.5 mg kg-1) using a randomised semi-crossover design with >= 48 hours between treatments in 10 male and 10 female mice. Each mouse was anaesthetised twice using the same administration route (IP or SC): once with each drug-ketamine combination. Anaesthetised mice were monitored on a heating pad without supplemental oxygen for 89 minutes; atipamezole was administered for reversal. The times that the righting reflex was lost post-injection and returned post-reversal were analysed using general linear models. Tail-pinch and pedal reflexes were examined using binomial generalized linear models. Pulse rate (PR), respiratory rate (fr), and arterial haemoglobin saturation (SpO2) were compared using generalized additive mixed models. There were no significant differences among treatments for the times taken for loss and return of the righting reflex, or response of the tail-pinch reflex. The pedal withdrawal reflex was abolished more frequently with MK than DK over time (P = 0.021). The response of PR and SpO2 were similar among treatments, but fr was significantly higher with MK than DK (P <= 0.0005). Markedly low SpO2 concentrations occurred within 5 minutes post-injection (83.8 +/- 6.7 %) in all treatment groups and were most severe after 89 minutes lapsed (66.7 +/- 7.5 %). No statistical differences were detected in regards to administration route (P <= 0.94). This study failed to demonstrate clinical advantages of the enantiomer dexmedetomidine over medetomidine when combined with ketamine to produce general anaesthesia in mice. At the doses administered, deep surgical anaesthesia was not consistently produced with either combination; therefore, anaesthetic depth must be assessed before performing surgical procedures. Supplemental oxygen should always be provided during anaesthesia to prevent hypoxaemia

Plasticity in transmission strategies of the malaria parasite, Plasmodium chabaudi : environmental and genetic effects

Parasites may alter their behaviour to cope with changes in the within-host environment. In particular, investment in transmission may alter in response to the availability of parasite resources or host immune responses. However, experimental and theoretical studies have drawn conflicting conclusions regarding parasites' optimal (adaptive) responses to deterioration in habitat quality. We analyse data from acute infections with six genotypes of the rodent malaria species to quantify how investment in transmission (gametocytes) is influenced by the within-host environment. Using a minimum of modelling assumptions, we find that proportional investment in gametocytogenesis increases sharply with host anaemia and also increases at low parasite densities. Further, stronger dependence of investment on parasite density is associated with greater virulence of the parasite genotype. Our study provides a robust quantitative framework for studying parasites' responses to the host environment and whether these responses are adaptive, which is crucial for predicting the short-term and evolutionary impact of transmission-blocking treatments for parasitic diseases

Studies in monolayer adsorption

The spreading properties of various sulphonated dyes containing alkyl chains have been studied, in monolayers on water. It is found that when spread on water partial or complete solution of the monolayer occurs. On decreasing the solubility of the dyes, however, by spreading on concentrated solutions of inorganic salts condensed films are obtained for all dyes with a chain length of 12 carbons or over. Dyes containing short alkyl chains (i.e. C4 and under) generally do not form surface films, though with the larger sized molecules gaseous films are formed. Mixing of cetyltrimethy lammonium brouide with the before spreading causes most of the short chain dyes, which do not form monolayers by themselves, to form a stable mixed film. It has been found that dyes which are surface-active (i.e. those dyes which form films without the aid of cetyltrimethylammonium bromide) are often less fast to light than non-surface active dyes. The inference is that the dyes which form stable monolayers at the air-liquid interface also form monolayers when ads bed on a substrate. Those dyes which do not form surface films, on the other hand, are believed to form a gregates in the substrate. The monolayer-forming dyes then expose a much larger solid-to-air surface in the substrate, resulting in a decrease in light fastness. Thus the light fastness of a series of dyes depends to some extent upon their surface activity; those which form monolayers are often the most fugitive. Cetyl acetate and methyl- and ethylstearyl ketones have been spread on aqueous solutions of various solutes. It is found that large dye molecules and medium-sized bifunetional molecules expand films of cetyl acetate, whereas the ketone films remain relatively unaffected. The dyes are believed to be bonded by both Van der Waals and polar forces whereas the bifunctional molecules are bonded mainly by polar forces and each molecule cross-links two film molecules. Cellulose triacetate films have also been studied. It is believed that when these are spread on water incomplete breakdown of the micelles occurs and aggregates as well as a monolayer are formed. The dyes are found to expand these partially spread films, and it is believed that the dyes have sufficient affinity to form comletes with the monolayer, but not enough to penetrate the micelles or aggregates by breaking the inter-chain bonds. Substances which are strongly bonded to cellulose triacetate, e.g. urea, can penetrate the micelles by breaking interchain bonds therein. The attachment of the non-ionic so-called 'disperse' dyes to cellulose triacetate has been studied by similar methods. A typical dye of this class, which is readily adsorbed by cellulose triacetate, when mixed with cellulose triacetate and spread as a mixed film gives no increase in the area of the film. It is suggested that the dye is oriented along the underside of the polymeric chains by polar and perhaps also by non-polar attraction. The effect of dyes on protein films was next studied. Acid dyes in acid solution expand these films but the expansion decreases with increase in pH and at pH 7.0 it approaches zero. These results were compared with the known adsorption properties of these dyes on wool, and it was found that the effect of pH is similar in both cases

Disease transmission and the ecological context

Epidemiology strongly parallels the study of ecology, primarily being concerned with the incidence, distribution, reproduction and persistence of species. The spread of disease, or its transmission, is arguably the most important incident studied in epidemiology, underpinning a pathogen’s ability to reproduce and persist within a host population. However, observations of individual transmission events are often impossible to observe directly, making variation in this process difficult to study. This has resulted in a great deal of epidemiological theory being based on homogenous transmission of disease through host populations. Understanding disease transmission as a heterogeneous process requires an appreciation of the ecological dynamics determining a pathogens ability to transmit. In this thesis a cross-disciplinary approach is taken to examine the ecological dynamics that may affect disease transmission at different ecological scales. In Chapter 2 I review empirical evidence in support of density dependent transmission. Transmission rates of density dependent transmitted diseases are often assumed to scale linearly with host population density. This assumption is pertinent to the calculation of the basic reproductive number R0. As R0 is important in determining optimal vaccination strategies, population thresholds and epidemic sizes, incorrect assumptions used in its calculation have the potential to misinform disease control strategies. Alarmingly, there is very little evidence to suggest that the prior assumption of a linear relationship between disease transmission rates and host population density exists. Where evidence of density dependent transmission has been found this has been best explained by non-linear relationships. Furthermore, density may have much stronger effects on disease transmission at small, local, scales (for example within one social grouping of hosts). Disease transmission between groups of hosts, at global scales, is more likely to follow frequency dependent dynamics. Disease transmission rates should thus be thought of as variable across populations that are not homogenously distributed in space, or across social structures. In Chapter 3 a community of pathogens infecting a population of rural red foxes, Vulpes vulpes, is described. Foxes cadavers were collected from a private estate 2 in Canterbury, Kent and a combination of direct and indirect testing for disease is used to maximise the scope of disease considered as part of this community. Specifically, I examine if any of the diseases included in this study occur together, or apart, more frequently than expected by chance alone. Within the samples collected it is found that the intracellular protozoan Toxoplasma gondii co-occurs with the virus canine adenovirus type-I (CAV-I) more frequently than expected by chance. Foxes concomitantly infected with these pathogens have lower condition scores than foxes who were not positive for both pathogens. From the data collected it is not clear whether hosts of lower condition are more susceptible to co-infection or if the co-infection is more harmful to hosts than being singly infected. T. gondii is not transmitted by foxes, but if infection with this parasite increases susceptibility to CAV-I then this virus may benefit from the presence of T. gondii within its host population. If it is the case that foxes of lower condition are simply more prone to co-infection then it should be expected that individual differences between hosts would cause heterogeneity in disease transmission. The need for cross-disciplinary approaches when studying pathogen communities is well demonstrated by this study, as is the need for more consideration to be paid to the community ecology of pathogens in epidemiological studies. In Chapter 4 a model is formulated to explore the effects of an interaction between a micro and a macro parasite. This is performed in the context of the increased prevalence and geographical range of the highly zoonotic small fox tapeworm Echinococcus multilocularis following successful rabies elimination in Western Europe. I explore the hypothesis that foxes with extremely high burdens may be at a higher risk of contracting rabies than foxes with low worm burdens, and thus rabies may have a regulatory effect on E. multilocularis populations by preferentially removing “super spreading” hosts. It is demonstrated that rabies limits E. multilocularis populations by limiting the density of available hosts. An interaction between rabies transmission rate and worm burden only caused a weak additional suppression on E. multilocularis populations, regardless of whether this relationship was linear or exponential. The elimination of rabies across Western Europe is certainly to be applauded. However, it should be noted from this work that surveillance of pathogen communities following successful eradication of one pathogen is of the upmost importance. 3 Finally, in Chapter 5 I examine how parasites adapt their investment in transmission in response to environmental changes experienced within a host. This is done by fitting models to data collected from mice infected with the malaria parasite Plasmodium chabaudi during the acute stage of inaction. Parasites are predicted to alter their behaviour in response to host stress, immunity and the availability of resources. However, theoretical and experimental studies reach conflicting conclusions regarding the “optimal response” to degradation of their habitat. Models were fitted to time series data from infection with one of six distinct genotypes. It is found that proportional allocation of resources into transmission, rather than replication, is highly sensitive to red blood cell (RBC) densities, with investment in transmission increasing as RBC resources become scarce. Investment in transmission also increases, albeit more weakly, in response to low parasite densities. These analyses highlight the fact that the complexity of interactions between parasites and their host hinder the identification of causal relationships, but supports recent work that questions the role of terminal investment in transmission in response to changes in the within-host environment. The broad scope of work presented here investigates a wide range of ecological factors (including community dynamics, habitat variability and reproductive success) at different ecological scales, responsible for heterogeneity in disease transmission. Transmission is a dynamic, and heterogeneous process. To better understand the ecology of disease it is logical to investigate the mechanisms behind this variation

Investigating Early Nucleosynthesis of the Lighter Heavy Elements

The \textit{r}-process produced half of all heavy elements in the universe today. While models successfully reproduce the abundance distributions of the heaviest elements observed in Ultra-Metal Poor stars, the lighter heavy elements ($36<Z<47$) are found to be more abundant than predicted. An additional nucleosynthesis process operating at early times in the universe, preferentially producing lighter heavy elements, has been proposed. This project consisted of experimental investigations into two candidates for this process: the weak \textit{r}-process in the neutrino-driven winds of core-collapse supernovae and the \textit{s}-process in rotating massive stars. The $^{20}$Ne(d,p)$^{21}$Ne reaction was studied using the HELIOS spectrometer at Argonne National Laboratory; angular distributions of energy levels in the $^{21}$Ne nucleus were measured to determine their neutron widths and spin-parities. These parameters are important for determining the neutron poisoning effects of $^{16}$O on the \textit{s}-process in rotating massive stars. Results for several levels are reported. $J^{\pi}=\frac{3}{2}^-$ and $\Gamma_n=7600\pm2100$\,eV was found for the 7820\,keV state disagreeing with the literature assignment of $2J^{\pi}=(3,5)^+$ and a neutron width limit of $\Gamma_n<7200$\,eV was determined for the first time for the 7749\,keV state. Resonance strengths calculated with these results are compared to literature. Both the 7749\,keV and 77820\,keV energy levels are of astrophysical interest. The reaction $^{86}$Kr($\alpha$,n)$^{89}$Sr was studied at TRIUMF using the EMMA recoil mass spectrometer. Partial cross sections of $1.0^{+0.6}_{-0.8}$\,mb and $0.8^{+0.7}_{-0.8}$\,mb were measured for transitions in the recoiling $^{89}$Sr nucleus from the 1032\,keV excited state to the ground state and from the 1473\,keV excited state to the ground state respectively; both measurements are in agreement with predictions. These results will help constrain uncertainty in model predictions of nucleosynthesis for each site and inform future experiments. Ultimately, these results contribute to determining the contribution of these two processes to the abundances of the lighter heavy elements at early times in the universe

A review of energy law education in the UK

This article focuses on reviewing energy law education in the UK. For such a fast-growing discipline it is important to reflect on the features that give cohesiveness to its curriculum development: how it is taught; who is teaching it and where it is being taught; and what content is given to the curriculum offered? Is it, for example, national in focus or international, or both? A recent review on the state of energy law education in the US demonstrates the scale and ambition of energy law education in that country. This article complements that exercise by providing a review of energy law education in the UK as at 2016. By comparing and contrasting the two approaches, we can glean some distinctive features of the UK approach. More research is needed on energy law education but from this article it is clear that energy law has taken a foothold in legal education in the UK

The role of Glycogen Synthase Kinase-3 in early embryonic stem cell differentiation

Embryonic stem cells, and the biochemical mechanisms underling their pluripotency has been the focus of intense research in recent years. Glycogen Synthase Kinase 3 (GSK3) has recently been implicated in a diverse array of cellular functions including embryonic stem cell pluipotency, and the aim of this thesis was to detail and investigate the regulation and role of GSK3 activity in controlling pluripotency and differentiation. This thesis has demonstrated that GSK3 kinase activity, normally considered constitutive, is suppressed in ES cells and is rapidly activated upon the commencement of difrerentiation. Activation of GSK3 enables phosphorylation and degradation of c-myc, which has been previously shown to be required for ES cell differentiation. Furthermore, this thesis presents evidence that GSK3 activity in ES cells may be regulated by subcellular translocation and phosphatases in response to signalling mediated by cellular attachment and other differentiation inducing events. A clearer understanding of the biology of pluripotent cells is necessary in order to better understand embryogenesis and the mechanisms of development, and to move towards the therapeutic potential of stem cells for use in cell based therapies. This study has added to our knowledge of GSK3 regulation with respect to its influence on the differentiation of embryonic stem cells.Thesis (M.Sc.) -- University of Adelaide, Dept. of Molecular and Biomedical Science, 200