3,088 research outputs found
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An evaluation of the impact of maternal substance abuse on infant and child attachment
This study examined the impact and extent to which drugs and alcohol, consumed by mothers prenatally and perinatally, has affected their capacity to attach to their children. It examined the role the dependent variables measured (i.e. drug(s)/substance(s) abused, demographic information) played in the attachment process. Data was collected from mothers currently participating in the perinatal substance abuse treatment at the San Bernardino County Rialto program
Quantum optics with 87Rb vapour in the hyperfine Paschen-Back regime
We present experimental studies of quantum optics with Rb vapour in the hyperfine Paschen-Back (HFPB) regime. We use a \SI{0.6}{\tesla} magnet to enter the HFPB regime, where, for Rb, the atomic transitions are separated by more than their Doppler width. This allows us to create clean 3- or 4-levels systems, which we model simply and effectively by solving the Lindblad master equation. We study electromagnetically induced transparency in a V configuration in the HFPB, where we see large, clean absorption and corresponding transmission features. We model the system, and use the model to understand the role of coherence in the features seen. We carry out seeded four-wave mixing in a double ladder scheme (5S--5P--5D), both in and out of the HFPB regime, and compare the two regimes. The simplicity of the system in the HFPB regime allows us to model the system to understand the features we see in the experimental spectra. We convert our seeded FWM into spontaneous FWM, which we use to produce pairs of heralded single photons. We find the zero-field regime to be more efficient for the production of these pairs, and measure , demonstrating that this is a single photon source. Throughout, we make use of lens cavity etalon filters, which we commission, characterise and compare to atomic line filters. We investigate fine structure changing collisions, which transfer atoms between 5P states, and can be a significant source of noise for quantum optics experiments in thermal vapours. We deduce that these are Rb-buffer gas collisions, measure the spectra of the fluorescence produced after a collision, and use the resolved spectra of the HFPB regime to determine that the nuclear spin magnetic quantum number, , is preserved in these collisions
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Carbide Composition Changes in Power Plant Steels as a Method of Remanent Creep Life Prediction
SIGLEAvailable from British Library Document Supply Centre- DSC:D061499 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Cytokines and epigenetic regulation of matrix metalloproteinases in tuberculosis
Tuberculosis (TB) remains a leading cause of death globally. Some of the morbidity and
mortality associated with TB arises from excessive or inappropriate immune activation in
response to infection. In pulmonary TB tissue destruction, cavitation and fibrosis drive
disease transmission and chronic lung dysfunction. The matrix metalloproteinases (MMPs)
are host enzymes controlling extracellular matrix turnover, immune cell recruitment and
activation, and they play a key role in the pathology of TB.
This project explores the regulatory mechanisms controlling MMP expression in TB using a
tissue culture model of respiratory epithelial cell and macrophage responses to
Mycobacterium tuberculosis (Mtb). The major human collagenase MMP-1 and its activator
MMP-3 are expressed in response to Mtb stimulation. The influence of exogenously added
cytokines IL-4, IL-10, IL-13, TGFÎČ and IFNÎł on MMP expression is investigated to examine
how immunopathology is driven by acquired immune responses. Epigenetic mechanisms
regulating MMP expression in response to Mtb are examined using inhibitors of histone
deacetylases (HDACs) and histone acetyltransferases, HDAC siRNA and chromatin
immunoprecipitation assays.
Mtb-induced collagenase expression by epithelial cells and macrophages is selectively
inhibited by the Th2 cytokines IL-4 and IL-13, but unaffected by IL-10. TGFÎČ enhances
epithelial cell MMP secretion but does not affect macrophage MMP expression. IFNÎł has
divergent effects, driving epithelial cell MMP secretion but inhibiting MMP-1 and -3
expression in macrophages. The intracellular pathways mediating these effects are
explored.
Mtb-driven MMP expression is sensitive to HDAC and HAT inhibition, and altered HDAC
expression is observed in Mtb-stimulated cells. Chromatin immunoprecipitation reveals
changes in histone acetylation at the MMP-1 promoter in Mtb-stimulated epithelial cells.
In pulmonary TB, production of matrix-degrading MMPs by epithelial cells and macrophages
is modulated by Th2 cytokines and IFNÎł. Key MMPs implicated in pulmonary
immunopathology are subject to epigenetic regulatory mechanisms, which may represent
potential targets for selective MMP inhibition.Open Acces
Superficially Similar but Fundamentally Different: A Comparative Analysis of US and UK Affirmative Action
This thesis compares affirmative action in the United States of America (US) and the United Kingdom (UK) and reveals that despite superficial similarities in how the US and UK have sought to achieve equal opportunities through the use of positive action the nature and impact of the laws are fundamentally different in each country. These differences flow from the multi-layered impact of the context â social, political and economic â within which each countryâs laws have developed. The context has in turn led to the formation of different principles upon which affirmative action has been founded and varying uses to which it has been put. This thesis also argues that, particularly in light of the most recent developments in positive action, the differing nature of the legal provision for affirmative action in each country may offer the opportunity for cross-referencing between the two countries. This could include learning lessons from problems encountered in the other country, and even borrowing some aspects of positive action policy. In this way the fundamentally different nature of the law between the two countries may direct the course of the future development of positive action, so that legal provisions that are currently mismatched to their contexts are loosed from their country-specific moorings and used to better effect on the opposite side of the Atlantic
A Critical Systems Explanation for the Racial Effect of US and UK Counter-terror Stop, Search and Surveillance Powers
Abstract
The racially disproportionate impact of counter-terrorism stop, search and surveillance powers, in the US and UK, has been widely borne out in statistical data, individual experiences and official reports. Such uneven police use of the powers failed to yield any discernible benefit in terms of safeguarding the population against the threat of terrorist attack and has instead been linked to the alienation of minority communities from law enforcement in both countries. Rather than seeing this outcome as a consequence of individual prejudice, this thesis uses a jurisprudential framework combining critical race theory and social systems theory to argue that, as a result of subsystem operational behaviours and obstructed inter-subsystem communications, what were intended as racially neutral, security-enhancing law enforcement tools were ineffective and racially uneven in deployment.
Through the case study of the stop, search and surveillance powers, within section 44 of the Terrorism Act 2000, in the UK, and sections 214 and 215 of the USA Patriot Act, in the US, this thesis describes the normal modes of subsystem operation, created by each subsystem and seen as necessary to uphold the rule of law and the legitimacy of that subsystem. This analysis also demonstrates that within the law-making, policing and judicial subsystems the risk, in terms of jeopardising the legitimacy and efficacy of subsystem operation and output, of departing from these ideal subsystem programmes, was recognised. Despite such an understanding, in their response to the national security threat arising form international terrorist activities each subsystem departed from its normal operational standards, whilst maintaining a confidence that other subsystems could withstand the pressures arising from these contextual circumstances and adhere to its normal modes of operation. This thesis also analyses the communications within and between the three subsystems to demonstrate how each misunderstood the communications of other subsystems because each interpreted these communications in accordance with its own, system-specific modes of understanding. These subsystem behaviours resulted in gaps in the oversight of the statutory powers and left them without stringent safeguards to protect against their misuse. Finally, this thesis draws together the findings relating to the causes and consequences of each subsystemâs operational programme and offers recommendations for reform by which each of the subsystems in both the US and UK may be able to safeguard against the recurrence of such deleterious law-making, policing and judicial adjudication in the face of each new threat to national security
Evaluating multiagency interventions for children living with intimate partner violence in Birmingham
This research endeavour was born out of the need for a systematic evaluation of the efficacy of the multiagency Domestic Abuse Risk Assessment tool, which necessitates that all incidents of âdomestic abuseâ (any incident within the family domain) reported to West Midlands Police, where a child or unborn child resides within that home, are scrutinised by Police and Social Care (and partners from Health, Education and the voluntary sector where possible) using a joint protocol. The primary purpose of the protocol is to promote safeguarding and provide a timely and appropriate response to children at risk following domestic abuse. The protocol incorporates the Banardosâ Multiagency Domestic Violence Risk Identification Threshold Scales (MDVRITS), which aids decision making about appropriate interventions based on predicted risk to children using a four level scale
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