711 research outputs found
MacWilliams' Extension Theorem for Bi-Invariant Weights over Finite Principal Ideal Rings
A finite ring R and a weight w on R satisfy the Extension Property if every
R-linear w-isometry between two R-linear codes in R^n extends to a monomial
transformation of R^n that preserves w. MacWilliams proved that finite fields
with the Hamming weight satisfy the Extension Property. It is known that finite
Frobenius rings with either the Hamming weight or the homogeneous weight
satisfy the Extension Property. Conversely, if a finite ring with the Hamming
or homogeneous weight satisfies the Extension Property, then the ring is
Frobenius.
This paper addresses the question of a characterization of all bi-invariant
weights on a finite ring that satisfy the Extension Property. Having solved
this question in previous papers for all direct products of finite chain rings
and for matrix rings, we have now arrived at a characterization of these
weights for finite principal ideal rings, which form a large subclass of the
finite Frobenius rings. We do not assume commutativity of the rings in
question.Comment: 12 page
A Substance Use Treatment Programme for Mentally Ill Forensic Patients in an Australian Setting: A Pilot Study of Feasibility, Acceptability and Preliminary Efficacy
This study aims to evaluate the feasibility, acceptability and preliminary efficacy of an Australian-adapted Substance Use Treatment Programme (SUTP) among mentally ill offenders in an Australian secure forensic setting. A single-group non-controlled pilot trial was conducted. Four SUTP treatment groups were run simultaneously (n = 39) with sessions held weekly over 12 weeks. Feasibility was assessed by examining attrition, study retention and motivation for treatment, and measures of therapeutic alliance, client satisfaction and qualitative interviews were used to determine acceptability. Preliminary efficacy was assessed using self-report questionnaires implemented at baseline and post intervention measuring drug related locus of control, confidence to resist substances in thefuture and beliefs about substance use. Low attrition, high levels of satisfaction and moderately positive levels of therapeutic alliance were found. Participants also demonstrated a significant shift towards an internal drug related locus of control upon completion of SUTP. SUTP is a promising intervention for mentally ill offenders with a history of substance use in Australian forensic services. A randomised controlled trial is warranted to rigorously evaluate the efficacy of SUTP in this setting
Integration of artificial intelligence into nursing practice
BACKGROUND: Artificial Intelligence (AI) is developing at a rapid pace and finding new applications across the health service team. Some professionals have voiced concerns over the implementation of AI, whilst others predict greater job opportunities in the future. Nursing practice will be directly affected and further information is required on the knowledge and perceptions of nurses regarding the integration of AI in practice. The study aims to assess the knowledge, attitude, willingness, and organizational readiness in integrating AI into nursing practice. METHODS: An exploratory cross-sectional survey of nurses working in health organisations. A survey link was emailed to participants. Nurses working in the United Arab Emirates (UAE) health organisations were invited to participate. Eligibility criteria included registered nurses in government or private hospitals. The survey captured the nurses demographic, knoweldage, preceptions, orgianizational readinesss and challenges regarding implementation of AI into nursing practice. RESULTS: 553 responses were returned from 650 invitation giving a response rate of 85%. 51% of respondents stated their knowledge on AI was obtained through self-taught measures for most of the participants, while 20% of them gained it through various courses. Only 8% stated they learned through postgraduate courses, while 9% stated they lack knowledge of AI. 75% of all respondents agreed that the nursing curriculum should include some basic knowledge of AI. CONCLUSIONS: There is a lack of understanding of the principles of AI across the nursing profession. Further education and training is required to enable a seamless and safe integration of AI into nursing practice
High performance liquid chromatography method development and chemometric analysis of ecstasy and cocaine
Consumption of illegal drugs of abuse remains a major social issue aligned with a \ud
global law-enforcement priority. Forensic analysts are faced with the challenge of \ud
continually developing sophisticated methods of analysis to combat the increasing \ud
variability that occurs in illicit drug samples. Research work for this thesis has \ud
focused on the development of High Performance Liquid Chromatography (HPLC) \ud
methods for the analysis of major drug constituents associated with ecstasy and \ud
cocaine illicit drug samples. Emphasis has been placed on method development with \ud
strategies of univariate or multivariate experimental approaches used in the selection \ud
and optimisation of procedures. Considerations with regard to the choice of \ud
chromatographic factors, solutes under investigation and the provision of quality \ud
assurance data throughout the research work have been the main criteria in methods \ud
developed. Two HPLC methods were developed to qualitatively and quantitatively \ud
assay for the major drug components and analogue derivatives found in ecstasy and \ud
cocaine. Methods developed have undergone validation studies including intra- and \ud
inter- reproducibility, accuracy, and linearity of calibration, limit of detection (LOD) \ud
and limit of quantification (LOQ) and the use of internal standards. Applications of \ud
methods to ecstasy and cocaine samples seized in Ireland ensured their suitability for \ud
routine analysis of illicit drug samples.\ud
As part of this study, chemical profiling of 183 ecstasy tablets seized in Ireland during \ud
2002-2004 were recorded as discrete data sets. Chemical data sets include both the \ud
quantification and occurrence in individual tablets of the major amphetamine \ud
components (i.e. MDA, MDMA, MDEA, MBDB methamphetamine and \ud
amphetamine), adulterant components (i.e. caffeine, phenacetin, acetaminophen and \ud
acetylsalicylic acid), excipients components (i.e. sucrose, glucose, lactose, fructose, \ud
mannitol, sorbitol and inositol) and inorganic components (i.e. Al, Zn, Fe, Mg, Ca, Cr, \ud
Pb, Na and K ). Chemometrics, including unsupervised methods of principal \ud
component analysis (PCA), hierarchical cluster analysis (HCA) and Pearson’s \ud
correlation coefficient, as well as supervised methods of linear discriminant analysis \ud
(LDA) and artificial neural networks (ANN) was applied to the chemical data sets to \ud
demonstrate the ability of the statistical approach to linking sample seizures. HCA \ud
and ANN were the numerical methods that most efficiently distinguished between\ud
5HPLC method development & chemometric analysis of ecstasy & cocaine\ud
linked and unlinked seizures. Eleven groups were identified from the chemical data \ud
sets with group classification dependant on the main amphetamine, adulterant and \ud
excipient components present. The benefits from this study can provide strategic \ud
intelligence and an understanding of the operational level on the Irish ecstasy market \ud
and help evaluate the changing profile or dynamics associated with this illegal market \ud
supply
Stressful events and adolescent psychopathology: A person-centred approach to expanding adverse childhood experience categories
Stress from cumulative adverse childhood experiences (ACEs) can pose a serious risk of experiencing anxiety, depression, and other mood disorders in adolescence. However, there is a paucity of research identifying specific profiles or combinations of exposure to other forms of stressful life events and their impact on adolescent psychopathology. This study attempted a conceptual expansion of the ACE checklist by examining these stressful events. The study used cross-sectional data from a modified version of the CASE Study survey where 864 adolescents (56% female, n = 480), aged from 11 – 18 years were recruited from four post-primary schools in the North-West region of NI. Latent class analysis of the 20-item stressful events checklist revealed 3 distinct risk classes: a low-risk class (53.5%), at-risk class (42.7%), and an immediate-risk class (3.8%). Results showed those at most risk of adolescent psychopathology had the highest probability of encountering interpersonal relationship issues, experiencing family dysfunction, and having close friends experiencing psychological difficulties. Findings indicate that the original ten ACE categories may be too narrow in focus and do not capture the wide range of childhood adversity. Expanding the ACE checklist to include other stressful events is discussed as these may also be antecedents to psychopathologic responses
Investigating the role of thiosulfate sulfurtransferase in adipose tissue dysfunction in obesity
Obesity is associated with dysfunction of adipose tissue due to oxidative stress and
inflammation, leading to insulin resistance. Thiosulfate sulfurtransferase (Tst) was
previously identified as an adipose-expressed anti-diabetic gene that protects against
diet-induced metabolic impairment when upregulated in adipose tissue of mice. TST
is a mitochondrial enzyme involved in the metabolism of cyanide, reactive oxygen
species (ROS) and endogenous hydrogen sulfide (H2S). This thesis tested the
hypothesis that TST maintains metabolic health in the face of dietary obesity. To do
this, I investigated the adipose-tissue phenotypes and metabolic consequences of Tst
gene deletion (Tst–/– mice) and of adipose tissue-specific overexpression of human
TST (Ad-hTST mice) after exposure to high fat diet (HFD).
After 20 weeks of HFD, Tst–/– mice exhibited impaired glucose tolerance
despite unchanged adipose tissue inflammatory cell infiltration, protein carbonylation
and unfolded protein response activation. However, levels of mRNA encoding
mitochondrial antioxidant enzymes including superoxide dismutase 2 and
peroxiredoxin 3 were lower in Tst–/– mice on HFD. Unexpectedly, chow-fed Tst-/- mice
had lower body weight and fat mass than wild-type controls highlighting a potential
effect of Tst on fat accumulation with age.
A new mouse model with high expression of human TST genetically targeted
to adipose tissue (Ad-hTST) was developed using the LoxP / Cre recombinase
expression system, with a parent line expressing Cre under the control of the
adiponectin promoter to confer adipose specificity. The Ad-hTST mice were found to
gain a similar amount of weight and fat mass to control mice when exposed to 6 weeks
of HFD. However, Ad-hTST mice had impaired glucose tolerance with no change in
inflammatory cell infiltration, mRNA levels of antioxidant enzymes or unfolded
protein response genes. Thus, unexpectedly, overexpression of human TST in adipose
tissue of mice results in a detrimental metabolic phenotype.
In vivo and in vitro experiments were conducted to test the hypothesis that TST
protects against ROS accumulation. Paraquat was tested as an inducer of oxidative
stress in vivo in wild-type, Tst-/- and Tst+/- mice. At the doses used (25mg/kg and
under), mice became unwell and lost weight, with no increase in markers of oxidative
stress in adipose or lung. The production of mitochondrial ROS in response to
exogenous hydrogen peroxide (H2O2) exposure was increased in primary adipocytes
from Tst-/- mice in vitro. However, primary hepatocytes showed reduced mitochondrial
ROS production in response to H2O2 exposure. ROS production in hepatocytes was
unaffected by pre-incubation with a H2S donor, an inhibitor of H2S-producing enzyme
CSE or N-acetyl-cysteine, an antioxidant. TST may therefore influence mitochondrial
ROS production differently in cell types such as adipocytes and hepatocytes. Disposal
of exogenous H2O2 was unchanged in primary adipocytes from Tst-/- and Ad-hTST
mice, and this was not affected by pre-incubation with sodium thiosulfate, a TST
substrate.
Metabolic changes in response to HFD may be influenced by alteration in TST
expression, however the current data suggest it is unlikely to occur through the
prevention of excessive local ROS accumulation in adipose tissue. Mice lacking the
Tst gene globally and mice with adipose-specific overexpression of the human TST
gene have a similarly impaired metabolic response to HFD. The phenotype of adipose-specific
human TST-overexpressing mice does not recapitulate the protective
metabolic phenotype produced by overexpression of the endogenous mouse Tst gene.
In conclusion, TST may influence adipose tissue due to its role in the oxidation of H2S,
however, by the current means, it does not appear to substantially impact the response
of this tissue to oxidative stress
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