10,546 research outputs found
Identifying and responding to people with mild learning disabilities in the probation service
It has long been recognised that, like many other individuals, people with learningdisabilities find their way into the criminal justice system. This fact is not disputed. Whathas been disputed, however, is the extent to which those with learning disabilities arerepresented within the various agencies of the criminal justice system and the ways inwhich the criminal justice system (and society) should address this. Recently, social andlegislative confusion over the best way to deal with offenders with learning disabilities andmental health problems has meant that the waters have become even more muddied.Despite current government uncertainty concerning the best way to support offenders withlearning disabilities, the probation service is likely to continue to play a key role in thesupervision of such offenders. The three studies contained herein aim to clarify the extentto which those with learning disabilities are represented in the probation service, toexamine the effectiveness of probation for them and to explore some of the ways in whichprobation could be adapted to fit their needs.Study 1 and study 2 showed that around 10% of offenders on probation in Kent appearedto have an IQ below 75, putting them in the bottom 5% of the general population. Study 3was designed to assess some of the support needs of those with learning disabilities in theprobation service, finding that many of the materials used by the probation service arelikely to be too complex for those with learning disabilities to use effectively. To addressthis, a model for service provision is tentatively suggested. This is based on the findings ofthe three studies and a pragmatic assessment of what the probation service is likely to becapable of achieving in the near future
The Influence of Frontal and Axial Plane Deformities on Contact Mechanics during Squatting: A Finite Element Study
Knee Osteoarthritis (KOA) is a degenerative joint disease and a leading cause of disability worldwide. Lower limb malalignment was a risky factor leading to KOA, altering the load distributions. This study aimed to study the influence of knee deformities on knee contact mechanics and knee kinematics during squatting. A full-leg squat FE model was developed based on general open-source models and validated with in vivo studies to investigate the outputs under frontal malalignment (valgus 8° to varus 8°) and axial malalignment (miserable malalignment 30°). As a result, Varus-aligned and miserable aligned models increased medial tibiofemoral force and lateral patellar contact pressures, while the valgus-aligned model increased lateral tibiofemoral force medial patellar contact pressures with no effects on total contact loads. The Model with a higher medial force ratio (medial force/total force) induced a higher internal tibial rotation. In conclusion, we recommended that patients with knee malalignment be taken care of alignments in both frontal and axial planes
Intermittent Faking of Personality Profiles in High-Stakes Assessments: A Grade of Membership Analysis
In high stakes assessments of personality and similar attributes, test takers may engage in impression management (aka faking). This paper proposes to consider responses of every test taker as a potential mixture of ‘real’ (or retrieved) answers to questions, and ‘ideal’ answers intended to create a desired impression, with each type of response characterized by its own distribution and factor structure. Depending on the particular mix of response types in the test taker profile, grades of membership in the ‘real’ and ‘ideal’ profiles are defined. This approach overcomes the limitation of existing psychometric models that assume faking behavior to be consistent across test items. To estimate the proposed Faking-as-Grade-of-Membership (F-GoM) model, two-level factor mixture analysis is used, with two latent classes at the response (within) level, allowing grade of membership in ‘real’ and ‘ideal’ profiles, each underpinned by its own factor structure, at the person (between) level. For collected data, units of analysis can be item or scale scores, with the latter enabling analysis of questionnaires with many measured scales. The performance of the F-GoM model is evaluated in a simulation study, and compared against existing methods for statistical control of faking in an empirical application using archival recruitment data, which supported the validity of latent factors and classes assumed by the model using multiple control variables. The proposed approach is particularly useful for high-stakes assessment data and can be implemented with standard software packages
Studies on the insecticidal mechanism of Bacillus thuringiensis Vip3A and Cry proteins
El control de plagas y patógenos ha tenido un efecto importante en la mejora del rendimiento de los sistemas agrícolas a nivel mundial. Diferentes tipos de insecticidas químicos se han usado extensivamente durante mucho tiempo para el control de plagas de insectos. Debido a la aparición de resistencias, problemas de contaminación de aguas y problemas de salud humana causados por dichos insecticidas de síntesis, la agricultura moderna necesita una estrategia de gestión integrada de plagas más saludable, respetuosa con el medio ambiente y sostenible. El uso de Bacillus thuringiensis (Bt) y sus proteínas insecticidas para el control de plagas es una de las estrategias biotecnológicas más importantes hasta la fecha. Además, los genes que codifican sus proteínas insecticidas han sido transferidos a plantas, las cuales están siendo utilizadas comercialmente, desde 1996 en gran parte del mundo para el control eficiente de numerosas plagas de insectos. En los últimos años, una nueva subclase de proteínas insecticidas secretables (Vip3) producida durante el crecimiento vegetativo de Bt se ha considerado para la aplicación combinada con las convencionalmente empleadas proteínas Cry, cuya aplicación se ve amenazada por la aparición de poblaciones de insectos resistentes. Las proteínas Vip3 no tienen homología de secuencia con las proteínas Cry y son tóxicas para insectos lepidópteros, sin embargo, su modo de acción todavía no se conoce completamente. En este proyecto de tesis, con el objetivo de mejorar su aplicación en el control biotecnológico de plagas y la comprensión del modo de acción de las proteínas Vip3, se estudiaron diversos aspectos de su actividad insecticida (espectro de acción, resistencia cruzada e interacción con otras proteínas), y se realizó un estudio de los residuos clave para el mantenimiento de la estructura tridimensional y la toxicidad de la proteína Vip3Af mediante mutagénesis dirigida. También analizamos la posible implicación de la unión a receptores en la aparición de resistencia utilizando una cepa resistente que había sido seleccionada con Vip3Aa. En primer lugar, se investigó la toxicidad de 10 toxinas Bt (Cry1Ab, Cry1Ac, Cry1Ah, Cry1Fa, Cry2Aa, Cry2b, Cry1Ie, Vip3Aa19, Vip3Aa16 y Vip3Ca) frente a Mythimna separata (plaga agrícola muy destructiva en Asia y Australia), así como su aplicación combinada mediante bioensayos llevados a cabo en laboratorio. Los resultados mostraron que la concentración letal media LC50 (Cry1Ac/Vip3Aa19/Vip3Ca 3061 veces) se obtuvo rápidamente después de 8 o 9 generaciones de selección en laboratorio. Sin embargo, no se obtuvo resistencia notable seleccionando con Cry1Ab o Cry1F en la misma población y durante el mismo número de generaciones. En un estudio realizado por otros investigadores, también se encontró una respuesta rápida similar a la selección de Vip3Aa en H. virescens, alcanzando un nivel de resistencia > 2300 veces mayor en la décima generación. Es importante hacer notar que esta rápida evolución de la selección en condiciones de laboratorio contrasta con los resultados obtenidos con las proteínas Cry1, tanto en nuestro trabajo como por otros autores: una la población de O. furnacalis adquirió un nivel de resistencia a Cry1Ab de alrededor de 100 veces sólo después de 35 generaciones de selección; de manera similar, una población de O. nubilalis desarrolló una resistencia de más de 3000 veces a Cry1F después de 35 generaciones de selección. Esta diferencia en respuesta a la selección, además de reflejar una frecuencia mucho mayor de alelos de resistencia para Vip3Aa, puede sugerir diferencias en los mecanismos de resistencia a las proteínas Vip3Aa y Cry1, lo cual queda en evidencia cuando se estudia la unión de Vip3A a BBMV de insectos resistentes El análisis de la unión de 125I-Vip3Aa a BBMV de larvas de M. separata tanto de insectos susceptibles y resistentes no reveló ninguna diferencia de unión, ya sea cualitativa o cuantitativa. Los resultados sugieren que la unión alterada a los receptores de la membrana del intestino medio no es el principal mecanismo de resistencia a la proteína Vip3Aa. Numerosos estudios han demostrado que la alteración de los receptores de membrana es un mecanismo evolutivo común que confiere altos niveles de resistencia a las proteínas Cry, pero nunca se ha establecido su relación con la resistencia a Vip3A. Las diferencias de unión cualitativas o c
Examining the Potential for Isotope Analyses of Carbon, Nitrogen, and Sulphur in Burned Bone from Experimental and Archaeological Contexts.
The aim of this project was to determine whether isotope analyses of carbon, nitrogen and sulphur can be conducted on collagen extracted from burned bone. This project was conducted in two phases: a controlled heating experiment and an archaeological application. The controlled heating experiment used cow (Bos taurus) bone to test the temperature thresholds for the conservation of δ13C, δ15N, and δ34S values. These samples were also used to test the efficacy of Fourier Transform Infrared spectroscopy (FTIR) and colour analysis, for determining the burning intensities experienced by bone burned in unknown conditions.
The experiment showed that δ13C values were relatively unchanged up to 400°C (<2‰ variation), while δ15N values were relatively stable up to 200°C (0.5‰ variation). Values of δ34S were also relatively stable up to 200°C (1.4‰ variation). Colour change and FTIR data were well correlated with the change in isotope ratios. Models estimating burning intensities were created from the FTIR data.
For the archaeological application, samples were selected from two early Anglo-Saxon cemetery sites: Elsham and Cleatham. Samples were selected from both inhumed and cremated individuals. Among the inhumed individuals δ13C values suggested a C3 terrestrial diet and δ15N values suggested protein derived largely from terrestrial herbivores, as expected for the early Anglo-Saxon period. However, δ34S values suggested the consumption of freshwater resources and that this consumption was related to both the age and sex of the individual.
The experimental data shows that there is potential for isotope analyses of cremated remains, as during the cremation process heat exposures are not uniform across the body. The samples selected for the archaeological application, however, were not successful. Bone samples heated in controlled conditions produced viable collagen for isotope analysis; however, there are several differences between experiments conducted in a muffle furnace and open-air pyre cremation that need to be investigated further. Additionally, the influence of taphonomy on collagen survival in burned bone needs to be quantified. Finally, methods of sample selection need to be improved to find bone samples from archaeologically cremated remains that are most likely to retain viable collagen. While there is significant research that must be conducted before this research can be widely applied there are a multitude of cultures that practised cremation throughout history and around the world that could be investigated through the analyses proposed in this project
Intervening on hypertension in Zambia: development of a culturally sensitized lifestyle programme to reduce disease incidence in urban areas
Background/purpose:
Hypertension, like other non-communicable diseases, is becoming a major public health problem for Sub-Saharan Africa (SSA). Its increasing prevalence is driven by an epidemiological transition with more people leading unhealthy lifestyles, including poor diet and physical inactivity. This project aimed to explore the use of participatory methods with an urban community in Zambia in co-developing a culturally sensitized hypertension prevention intervention.
Methods:
The intervention development study was divided into four phases. I scoped and synthesized existing literature on risk factors (non-modifiable and modifiable) for hypertension in SSA in Phase One. The identified risk factors and their drivers informed Phase Two community members focus group discussions and stakeholder interviews to explore the local context in the study site to clarify the problem, identify which hypertension risk factors were malleable (potential factors to target), the mechanism of change, and how to deliver this. The findings informed the development of the causal pathway, the intervention theory of change and the Phase Three co-development of the intervention core components and small-scale evaluation. Five co-development workshops (four with local residents and one with local stakeholders) iteratively informed identification of priority risk factors, the delivery format and setting, and finalization of intervention core components. The pilot intervention was then tested with volunteer participants (N=34) to assess feasibility, acceptability and potential effectiveness in Phase four.
Results:
The scoping review identified the most common risk factors for hypertension in SSA. Residents FGDs and key stakeholder interviews, informed by the scoping review findings, identified a number of potentially malleable hypertension risk factors at individual and interpersonal levels, including high salt intake and other dietary factors, low physical activity, excess body weight, central obesity, high alcohol intake and smoking. From these, the workshops prioritised intervening on salt intake, other dietary factors, and physical inactivity. Using these suggestions, an 8-week group-based intervention (CHiPI) was codeveloped. Stakeholders proposed evaluation of the CHiPI on a small scale and delivery through churches: “nearly all residents belong to a church”. Stakeholders also identified community health workers and church leaders as delivery facilitators. The intervention core components were agreed and refined in close consultation with residents. These included linguistic and cultural adaptations of SMART goal setting and self-monitoring tools, which were iteratively tested and refined to reflect the local socio-cultural context. The small-scale evaluation of the intervention showed high acceptability, feasibility and potential effectiveness in improving health literacy, adoption of healthier diets (less salt added during cooking [p=0.014], reduction in added salt to the plate at mealtimes [p=0.001], increased fruit intake [p=0.001], reduced fried meals [p = 0.001]), increased physical activity [p=0.01] and reduced sedentary lifestyle [p = 0.001]. Reductions in body weight [p = 0.002], BMI [p = 0.001], WC [p = 0.001], SBP [-3mmHg, p=0.003] and DBP [-4mmHg, p = 0.001] were also observed.
Conclusions and implications:
Participatory methods succeeded in engaging local residents and stakeholders in the development of a potentially effective culturally sensitized, 8-week, group-based hypertension prevention lifestyle intervention for delivery through churches in Zambia. Having demonstrated high feasibility, acceptability and potential effectiveness, taking this intervention to a larger evaluation to obtain evidence of effectiveness can inform hypertension prevention intervention development in Zambia and other SSA countries
Applying cognitive electrophysiology to neural modelling of the attentional blink
This thesis proposes a connection between computational modelling of cognition and cognitive electrophysiology. We extend a previously published neural network model of working memory and temporal attention (Simultaneous Type Serial Token (ST2 ) model ; Bowman & Wyble, 2007) that was designed to simulate human behaviour during the attentional blink, an experimental nding that seems to illustrate the temporal limits of conscious perception in humans. Due to its neural architecture, we can utilise the ST2 model's functionality to produce so-called virtual event-related potentials (virtual ERPs) by averaging over activation proles of nodes in the network. Unlike predictions from textual models, the virtual ERPs from the ST2 model allow us to construe formal predictions concerning the EEG signal and associated cognitive processes in the human brain. The virtual ERPs are used to make predictions and propose explanations for the results of two experimental studies during which we recorded the EEG signal from the scalp of human participants. Using various analysis techniques, we investigate how target items are processed by the brain depending on whether they are presented individually or during the attentional blink. Particular emphasis is on the P3 component, which is commonly regarded as an EEG correlate of encoding items into working memory and thus seems to re ect conscious perception. Our ndings are interpreted to validate the ST2 model and competing theories of the attentional blink. Virtual ERPs also allow us to make predictions for future experiments. Hence, we show how virtual ERPs from the ST2 model provide a powerful tool for both experimental design and the validation of cognitive models
Solar wind - magnetosphere coupling functions: pitfalls, limitations and applications
Solar wind-magnetosphere coupling functions have now been in use for almost 50 years. In that time, a very large number of formulations have been proposed. As they become increasingly subsumed into systems analysis and machine-learning studies of the magnetosphere, it is timely to establish best practice in their derivation and study their limitations. This paper reports on a number of studies carried out to establish some key points. Particular attention is paid to the best metric used to evaluate their performance and how it depends on the application for which the coupling function is intended
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