The current study utilized structural equation modeling (SEM) to examine the factor-to-factor relations and temporal associations between disturbances in negative affect (NA) and positive symptoms of psychosis (PP). Data were drawn from a large, public-domain data set (MacArthur Violence Risk Assessment Study). A dimensional approach was used to conceptualize and identify latent variables of NA (depression, anxiety, and guilt) and PP (hallucinations, delusions, and thought disorder) among individuals with a diagnosis of primary psychotic disorder. Results showed that anxiety, guilt, and depressed mood modeled an NA latent variable, and that hallucinations and unusual thought content modeled a PP latent variable. As predicted, results revealed strong, significant cross-sectional (synchronous) associations between NA and PP at each measured time-frame, suggesting that NA and PP occurred concurrently within the sample. Contrary to predictions, no significant cross-lagged effect between NA and PP was identified (10 weeks and 20 weeks respectively).

The negative selection algorithm developed by Forrest et al. was inspired by the manner in which T-cell lymphocytes mature within the thymus before being released into the blood system. The resultant T-cell lymphocytes, which are then released into the blood, exhibit an interesting characteristic: they are only activated by non-self cells that invade the human body. The work presented in this thesis examines the current body of research on the negative selection theory and introduces a new affinity threshold function, called the feature-detection rule. The feature-detection rule utilises the inter-relationship between both adjacent and non-adjacent features within a particular problem domain to determine if an artificial lymphocyte is activated by a particular antigen. The performance of the feature-detection rule is contrasted with traditional affinity-matching functions currently employed within negative selection theory, most notably the r-chunks rule (which subsumes the r-contiguous bits rule) and the hamming-distance rule. The performance will be characterised by considering the detection rate, false-alarm rate, degree of generalisation and degree of overfitting. The thesis will show that the feature-detection rule is superior to the r-chunks rule and the hamming-distance rule, in that the feature-detection rule requires a much smaller number of detectors to achieve greater detection rates and less false-alarm rates. The thesis additionally refutes that the way in which permutation masks are currently applied within negative selection theory is incorrect and counterproductive, while placing the feature-detection rule within the spectrum of affinity-matching functions currently employed by artificial immune-system (AIS) researchers. / Dissertation (MSc)--University of Pretoria, 2009. / Computer Science / Unrestricted

The problems we studied in this thesis are linearly constrained convex programming (LCCP) and nonnegative matrix factorization (NMF). The resolutions of these two problems are all closely related to convex programming with simple convex constraints. The work can mainly be described in the following three parts. Firstly, an interior point algorithm following a parameterized central path for linearly constrained convex programming is proposed. The convergence and polynomial-time complexity are proved under the assumption that the Hessian of the objective function is locally Lipschitz continuous. Also, an initialization strategy is proposed, and some numerical results are provided to show the efficiency of the proposed algorithm. Secondly, the path following algorithm is promoted for general barrier functions. A class of barrier functions is proposed, and their corresponding paths are proved to be continuous and converge to optimal solutions. Applying the path following algorithm to these paths provide more flexibility to interior point methods. With some adjustments, the initialization method is equipped to validate implementation and convergence. Thirdly, we study the convergence of hierarchical alternating least squares algorithm (HALS) and its fast form (Fast HALS) for nonnegative matrix factorization. The coordinate descend idea for these algorithms is restated. With a precise estimation of objective reduction, some limiting properties are illustrated. The accumulation points are proved to be stationary points, and some adjustments are proposed to improve the implementation and efficiency

No description available.

This research project investigates the effectiveness of mentors on rates of self-reported criminal offending for released offenders. I use data from the Serious and Violent Offender Reentry Initiative (SVORI) study (2004-2007), which sought to evaluate factors relating to high-risk offenders outcomes post release in an effort to reduce the societal problem of mass incarceration. Previous research has examined the use of mentors to improve the delinquent and criminogenic behavior of youth, but little is known about the effectiveness of mentors used to aid imprisoned adult males. I utilize negative binomial analysis to compare the number of self-reported criminal activities among released offenders with mentors versus those without mentors, and assess if the values varied between different reported levels of need for mentoring. Results indicate that mentoring did not reduce the rate of post-release offending at a statistically significant level. Reasons for the lack of significant results and policy implications are discussed.

Colistin, also known as polymyxin E, is antibiotics active against most of Gram-negative bacteria. In the pas decade, emergency of multidrug-resistant bacteria led to increase of colistin administration as a last resort antibiotic for human infections. The first plasmid-mediated colistin resistance gene mcr-1 was identified in 2015 in animals in China and after first detection, additional mcr genes: mcr-2, mcr-3, mcr-4, mcr-5, mcr-6, mcr-7 a mcr-8 were described throughout the world. The aim of this thesis was to clarify whether there is horizontal transmission colistin resistance encoded by the mcr genes in gram-negative bacteria isolated from the environment, animals and their breeding and food. The mcr-1 gene was detected in 2 strains Escherichia coli isolated from waste water. The mcr-4 gene was detected in 1 strain Shewanella putrefaciens isolate obtained from the lake. The environment is the most important source and way of spreading this type of resistance in the Czech Republic.

Objetivo: Una tasa de apendicectomía negativa (AN) entre 10-15% es considerada aceptable. Sin embargo, a nivel internacional el rango va entre 2-9%. El presente estudio busca identificar la TAN y los factores asociados a esta. Métodos: Estudio retrospectivo de todas las apendicectomías realizadas entre los años 2012 y 2013 en una clínica privada de Lima-Perú. Se revisó las historias clínicas de pacientes apendicectomizados que contaron con historia clínica de emergencia e informe quirúrgico. Se excluyó a aquellos que no contaban con informe anatomopatológico del apéndice. Se calculó los OR ajustados con un modelo de regresión logística para identificar los factores asociados con AN. Resultados: Se realizaron 376 apendicectomías durante el periodo 2012-2013. Se excluyeron 13 casos por no contar con registro de historia clínica. La población femenina fue de 55,9%. La media de edad del paciente fue 33,4 años ± 17,6. En 28 de 363 pacientes (7,7%) se registró una AN. Se encontró que el dolor en flanco derecho (OR: 5,44 P=0,013), Mc Burney negativo (OR: 3,63 P=0,017), dolor en hipogastrio (OR: 3,05 P=0,030),) y no leucocitosis (OR: 2,85 P=0,015) son factores asociados a una AN. Las patologías más frecuentemente implicadas en el caso de una AN fueron las de causa ginecológica (53,6%) seguida de enfermedad diverticular complicada (14,3%). Conclusión: Los resultados obtenidos indican que la presencia de dolor en hipogastrio, dolor en flanco derecho, Mc Burney negativo y no leucocitosis son factores diagnósticos que se pueden tener en cuenta para prevenir apendicectomías negativas. / Background: A negative appendectomy rate (NAR) between 10-15% is considered acceptable. Nevertheless, internationally the range is between 2-9%. This study seeks to find factors associated with a negative appendectomy (NA) and the NAR. Methods: Retrospective study of all appendectomies performed between 2012 and 2013 at a private hospital of Lima-Perú. We reviewed the medical records of patients who underwent appendectomy and had a medical report of emergency. We excluded the ones whithout pathology reports. Adjusted ORs were calculated with a logistic regression model to identify factors associated with AN. Results: Three hundred seventy-six appendectomies were performed for suspected appendicitis 55.9% in women). The average patient age was 33.4 ± 17.6 years. A NA was found in 28 of 363 patients (7,7%). We found that pain in right flank (OR: 5,44 P=0,013), negative Mc Burney (OR: 3,63 P=0,017), pain in hypogastrium (OR: 3,05 P=0,030),) and no leucocitosis (OR: 2,85 P=0,015) were associated factors to AN. Gynecologic conditions (53,6%) and intestinal diseases (14.3%) are the most common to be misdiagnosed as appendiceal disease. Conclusion: The obtained results indicate that the presence of pain in the right flank, negative Mc Burney, pain in hypogastrium and no leukocytosis are diagnostic factors that can be taken into account to prevent negative appendectomy. / Tesis

This study deals with the nature and characteristics of the Gram negative bacterial flora of the intestine of the domestic pigeon. Columba livia was selected for this study because of the abundance of this species around the Classroom building on the University of the Pacific campus.

No description available.

Adolescents with body image dissatisfaction experience more anxiety than their peers who are more satisfied with their body. This is problematic given that adolescents who experience these concerns have a greater likelihood of later developing other mental health disorders and have more disordered eating cognitions and behaviour. For this reason, I investigated how body image dissatisfaction, social anxiety, and fear of negative evaluation were related to one another. Participants included 527 adolescents (301 girls; aged 15 to 19 years; 83.1% White) who were accessed annually over 4 years (Grade 10 to one-year post high school) using the Multidimensional Anxiety Scale for Children, the Brief Fear of Negative Evaluation scale-II, and validated questions to assess body image dissatisfaction. A developmental cascade model was used to examine direct and indirect effects between the study variables. Results indicated two significant indirect paths; body image dissatisfaction to social anxiety via fear of negative evaluation and body image dissatisfaction to fear of negative evaluation via social anxiety. Direct effects included a reciprocal positive association between body image dissatisfaction and social anxiety in mid-adolescence and a reciprocal positive association between social anxiety and fear of negative evaluation across adolescence. Lastly, there was a positive association from body image dissatisfaction to fear of negative evaluation across adolescence. These results suggest that adolescents with low body image dissatisfaction are likely to experience greater fear and anxiety regarding social interaction. This study emphasizes the need to target adolescents with body image intervention programs to reduce the experience of psychopathology.