Molecular Studies of Treponema pallidum

Syphilis, caused by Treponema pallidum (T. pallidum), has re-emerged in the UK and globally. There are 11 million new cases annually. The WHO stated the urgent need for single-dose oral treatments for syphilis to replace penicillin injections. Azithromycin showed initial promise, but macrolide resistance-associated mutations are emerging. Response to treatment is monitored by serological assays that can take months to indicate treatment success, thus a new test for identifying treatment failure rapidly in future clinical trials is required. Molecular studies are key in syphilis research, as T. pallidum cannot be sustained in culture. The work presented in this thesis aimed to design and validate both a qPCR and a RT-qPCR to quantify T. pallidum in clinical samples and use these assays to characterise treatment responses to standard therapy by determining the rate of T. pallidum clearance from blood and ulcer exudates. Finally, using samples from three cross-sectional studies, it aimed to establish the prevalence of T. pallidum strains, including those with macrolide resistance in London and Colombo, Sri Lanka. The sensitivity of T. pallidum detection in ulcers was significantly higher than in blood samples, the likely result of higher bacterial loads in ulcers. RNA detection during primary and latent disease was more sensitive than DNA and higher RNA quantities were detected at all stages. Bacteraemic patients most often had secondary disease and HIV-1 infected patients had higher bacterial loads in primary chancres. Treatment kinetics following benzathine penicillin injection were assessed in four men. The mean half-life for both blood and ulcer T. pallidum nucleic acid clearance was found to be short. All patients had serology consistent with cure at one month. Two T. pallidum strain types were found in Colombo, neither harbouring macrolide resistance. In London, several strain types were identified, the majority of which contained genetic determinants of macrolide resistance.Open Acces

Strategies for Enhancing the Performance of Chemical Sensors Based on Microcantilever Sensors

Microcantilever (MC) based chemical sensors have become more widely used during the past 10 years due to the advantages they possess over other chemical sensors. One of the most significant characteristics is their extremely high surface to volume ratio. This key facet allows surface forces that can be ignored on a macroscale to become a significant sensing transduction mechanism. MC based sensors also exhibit a higher mass sensitivity to adsorbates than do many other chemical sensor platforms. Under many conditions, MC based sensors directly translate changes in Gibbs free energies due to analyte-surface interactions into mechanical responses. However, the widespread application of MCs in the field of sensors has yet to be fully realized. This is primarily due to the lack of a unifying methodology and instrumentation that would allow various research groups to benefit from a combined wealth of knowledge on the subject. The underlying goal of this research is to broaden the depth and scope of knowledge of MC based chemical sensors. By working on several areas in a coherent order, the limitations of MC based sensors have been determined and largely overcome. The information gathered in all aspects of this project will be useful to present and future researchers in this field. The initial research was focused on the application of various chemical films to MC sensors to be able to measure a wide range of chemical species. In one case, thin films of polymeric gas chromatography (GC) phases were deposited onto V-shaped MCs. A main strength to using GC phases was that the responses of the analytes could be predicted before hand by using the McReynolds constants of the phases used. This allowed for the detection and quantification of various chemical species using these moderately selective phases. vi During this phase of research it was discovered that methods for enhancing MC response were needed to overcome some of the traditional problems facing MC based sensors. By employing a new type of underlying nanostructured metallic film, MC response was greatly enhanced. This resulted in a better limit of detection and wider dynamic range relative to previous results with smooth surface MCs. In addition to advances resulting from nanostructuring, important advances were made in MC coating strategies. The widely used and well-characterized process of physical vapor deposition was used to deposit both organic and polymeric materials onto the MC surface. This process allowed for uniform films to be deposited with tailored thicknesses and for individual MCs on a single chip to be coated selectively. Another approach involving the immersion of MCs into fused silica capillaries containing solutions of thiolated materials was also developed. This method also allowed for individual MCs in an array to be selectively coated. Finally, out of these results and a developing trend of using sensor arrays came the need to increase the robustness and selectivity of MC based systems. Two different systems for achieving these goals were developed. First, a simple differential system based upon dual diode lasers was constructed in order to eliminate common sources of noise and non-specific interactions that decrease the dynamic range of these sensors. This system was also applied to the quantification of individual components in a binary mixture. While this system has met only limited success, it has been a beneficial first step towards MC systems of higher order. Towards that goal, a system designed to measure multiple MCs simultaneously using an array of vertical cavity surface emitting lasers was also used. This system measures the responses of multiple MCs exposed to an vii analyte in a single run and provides unique response patterns for that analyte. This allowed for the qualitative analysis of a simple mixture to be performed

Book Review: Affect in Artistic Creativity – Painting to Feel by Jussi A. Saarinen

Most Art Therapists and Art Psychotherapists have a belief in the healing qualities of the media. It is a shared article of faith that creative material processes, of themselves, can promote the development of health and stability. Nevertheless, we also know that the relation to the material element is not without hazard. This is a problem for us, I think, because we can never be certain about the relationship between a service user, or client, and the physical material she manipulates. In terms of the relation that the other has to substance and process, we are always on the outside.  This book by Jussi A. Saarinen, who is a psychologist and a post-doctoral researcher in philosophy, explores the painter’s relationship to painting, the ‘experience itself’ (2021: 1. italics the author). Saarinen stresses that he is not concerned with expression but with what painters feel ‘because they paint’ (2021:1). His book is essentially a carefully constructed argument, which engages with philosophical literatures, psychoanalysis, recent cognitive theory and interviews with artists, in support of the proposition that: “Painters paint to feel.” (2021: 1.  Italics the author).  &nbsp

A 2-D, variable-density numerical model of subsurface fluid flow through the Edwards Aquifer, New Braunfels, TX: mechanisms inhibiting flow across the freshwater/saline-water interface

The Edwards aquifer in south-central Texas, U.S., composed of faulted carbonate bedrock, contains freshwater and saline water. In aquifers that are used as a source of drinking water and that contain fresh and saline waters, saline-water intrusion can result in degradation of water quality. Yet, in the Edwards aquifer, limited saline-water intrusion has occurred. The questions addressed are “Why is the saline-water intrusion less than expected,” and “Is there a trigger that will result in saline-water intrusion into the freshwater reservoir?” Three hypotheses were tested. One: an extremely saline water density might prevent mixing across the interface. Two: faults could be acting as a barrier between the freshwater and saline-water zones, preventing movement of the saline water into the freshwater zone. Three: the permeability of the bedrock in the saline water zone might be extremely low, limiting movement of the saline water. A transect of observation wells was chosen in New Braunfels, TX for study. 2-D, variable-density numerical models of groundwater flow were used to determine which factor controlled the lack of saline-water intrusion. Numerical models were produced for each hypothesis using Basin2. It is clear from each model that fault permeability and fault compartmentalization is the primary mechanism inhibiting flow across the freshwater/saline-water interface. When horizontal fault permeability reached 0.01 D, flow was significantly reduced across the interface. When these values reached 0.001 D, flow across the interface ceased. To a lesser extent, saline-water zone permeability controlled the movement of flow across the interface, if permeability values were reduced by three orders of magnitude. However, extremely high saline water densities did not inhibit flow. A trigger that would increase fault permeability would be continued dissolution of the carbonate rocks, but it most likely would take tens of thousands of years for dissolution to significantly increase the permeability of the fault surfaces. In addition, dedolomitization of the saline water zone would be another trigger that would induce flow across the interface, but since little diagenesis in the saline water zone has been observed, dedolomitization is not a pressing issue

Event-related alpha desynchronization in touch - comparing attention and perception

An event-related decrease in alpha power contralateral to the presentation of a stimulus is now a well-established phenomenon. Two distinct accounts of the functional role of alpha changes are present in the literature that either focus on alpha changes observed during attentional or simple perceptual tasks. This study directly compares tasks that invoke alpha decreases during exogenous, endogenous and perceptual processing. Using a data driven approach to compare alpha changes we show that alpha decreases differ only between exogenous and endogenous attention tasks for only a short time window, 500–600 ms after cue onset. We suggest this indicates a role for alpha in voluntary orientating and stimulus predictability

Editorial

Here in the UK the NHS is, as might be expected, very much in the news, and the threat of the world-wide pandemic, as our readers will know, has affected all our practices, exposing inequalities, economic, political and social failures, which demand attention. This volume of the journal, produced under the shadow of our contemporary anxieties, addresses the imperative of the present situation. The contents of this issue reveal aspects of the current contexts in which art therapy practitioners, artists, trainers, students and researchers, are exploring experience, developing new practices and creating fresh understanding.&nbsp

Clear as Mud: Recreating Public Water Rights That Already Exist

“Speculation. Water monopoly. Land monopoly. . . . John Wesley Powell was pretty well convinced that those would be the fruits of a western land policy based on wishful thinking, willfulness, and lousy science.”186 PWR 107 was created to avoid water monopolization through land reservation. However, it would seem that management of public water reserves on federal lands has succumbed to some of John Wesley Powell’s concerns: management has been incomplete, ad hoc, and potentially based on incomplete hydrological data. PWR 107, as well as federal water reserves in general, pits western states against the BLM where there is a lack of comprehensive and clear reserves. As priorities for water uses on public lands shift, well-founded policy for resource allocation must include quantification and clarification of federally reserved waters. Public citizens will possibly leverage PWR 107 to challenge energy development where the BLM is otherwise complicit, especially as new technologies allow for extraction of resources previously inaccessible. Energy development companies will need to work more with federal and state water authorities as prior appropriation has already tied up most water resources in the West. These pressures will inevitably require federal courts to further define the scope and intentions of PWR 107. Utah faces additional uncertainty over federal reserved water rights claims involving Indian water reservations, national parks, and wilderness reserves. As these demands for water become more relevant and valuable, Utah and the federal government will need to define competing reservation priorities and legal duties. This will need to be done through clear policy definition, assertions of federal authority, comprehensive planning, and consideration of public interests and involvement. Should competing interests come to a head as they have in Nevada, the Utah public may be able to leverage PWR 107 to assert public interests in unclear water claims. This would require the judiciary to instead grapple with clarifying what water reservation purposes and duties are and could lead to further confusion. Western water rights were originally secured despite competing interests, priorities, and governments. While complete monopolies may have been avoided, and life in the desert has been supported, the next juncture in federal reserved water rights and PWR 107 claims will no doubt be momentous. The present circumstances in Utah provide a ripe environment for defining the next phase of PWR 107 legal authority—possibly recreating or changing what these water rights actually are

Cost and benefits of rent control in Kumasi, Ghana

Over the past forty years, rent control has been a feature of housing in Ghana. This study focusses on the housing market in Kumasi, the second largest city in Ghana. The authors examine the characteristics of the rent control regime in force there, and assess the costs and benefits of rent control, on landlords and on tenants, and its effect on the housing stock. Rent control has been successful in ensuring that housing is very inexpensive for most households, in both absolute terms and in the proportion of income devoted to rent. Thesecontrols have deprived landlords of economic returns on their property, causing them to withdraw stock from renting to use for their own family members and to reduce maintenance. However, rent control is not the only constraint on the housing market, in Kumasi or in Ghana. The paper also describes other supply side and regulatory constraints; such as those affecting land, finance, and choice of building design and materials. A number of options for relaxation/decontrol are studied with the aid of a simple present value model. Along with decontrol of new construction it is recommended that floating up and out of controls over a five year period should be considered, along with policy changes to ensure ready supplies of land, finance, and building materials. Such policies are essential, given that private housing investment provides the great majority of rooms in Ghanaian urban areas.Non Bank Financial Institutions,Banks&Banking Reform,Housing Finance,Housing&Human Habitats,Economic Theory&Research