Comparison of PSO and GA for K-Node Set Reliability Optimization of a Distributed System

Particle Swarm Optimization (PSO), as a novel evolutionary computing technique, has succeeded in many continuous problems, but quite a little research on discrete problem especially combinatorial optimization problem has been reported. In this paper, a discrete PSO algorithm is proposed to solve a typical combinatorial optimization problem: K-Node Set Reliability (KNR) optimization of a distributed computing system (DCS) which is a well-known NP-hard problem is presented. It computes the reliability of a subset of network nodes of a DCS such that the reliability is maximized and specified capacity constraint is satisfied. The feasibility of the proposed algorithm is demonstrated on 8 nodes 11 links DCS topology. The test results are compared with those obtained by the genetic algorithm (GA) method in terms of solution quality and convergence characteristics. Experimental study shows that the proposed PSO algorithm can achieve good results

Problem and pro-social behavior among Nigerian children with intellectual disability: the implication for developing policy for school based mental health programs

<p>Abstract</p> <p>Background</p> <p>School based mental health programs are absent in most educational institutions for intellectually disabled children and adolescents in Nigeria and co-morbid behavioral problems often complicate intellectual disability in children and adolescents receiving special education instructions. Little is known about prevalence and pattern of behavioral problems existing co-morbidly among sub-Saharan African children with intellectual disability. This study assessed the prevalence and pattern of behavioral problems among Nigerian children with intellectual disability and also the associated factors.</p> <p>Method</p> <p>Teachers' rated Strengths and Difficulties Questionnaire (SDQ) was used to screen for behavioral problems among children with intellectual disability in a special education facility in south eastern Nigeria. Socio-demographic questionnaire was used to obtain socio-demographic information of the children.</p> <p>Results</p> <p>A total of forty four (44) children with intellectual disability were involved in the study. Twenty one (47.7%) of the children were classified as having behavioral problems in the borderline and abnormal categories on total difficulties clinical scale of SDQ using the cut-off point recommended by Goodman. Mild mental retardation as compared to moderate, severe and profound retardation was associated with highest total difficulties mean score. Males were more likely to exhibit conduct and hyperactivity behavioral problems compared to the females. The inter-clinical scales correlations of teachers' rated SDQ in the studied population also showed good internal consistency (Cronbach Alpha = 0.63).</p> <p>Conclusion</p> <p>Significant behavioral problems occur co-morbidly among Nigerian children with intellectual disability receiving special education instructions and this could impact negatively on educational learning and other areas of functioning. There is an urgent need for establishing school-based mental health program and appropriate screening measure in this environment. These would afford early identification of intellectually disabled children with behavioral problems and appropriate referral for clinical evaluation and interventions. The need to focus policy making attention on hidden burden of intellectual disability in sub-Saharan African children is essential.</p

Factors influencing knowledge about childhood autism among final year undergraduate Medical, Nursing and Psychology students of University of Nigeria, Enugu State, Nigeria

<p>Abstract</p> <p>Background</p> <p>Knowledge and awareness about childhood autism is low among health care workers and the general populace in Nigeria. Poor knowledge about childhood autism among final year medical, nursing and psychology students who would form tomorrow's child health care professionals can compromise early recognition and interventions that are known to improve prognosis in childhood autism. Educational factors that could be influencing knowledge about childhood autism among these future health care professionals are unknown. This study assessed knowledge about childhood autism among final year undergraduate medical, nursing and psychology students in south-eastern Nigeria and determined the factors that could be influencing such knowledge.</p> <p>Methods</p> <p>One hundred final year undergraduate students were randomly selected from each of the Departments of Medicine, Nursing Science and Psychology respectively of University of Nigeria, Enugu State, Nigeria making a sample size of three hundred. A socio-demographic questionnaire and knowledge about childhood autism among health workers (KCAHW) questionnaire were administered to the students.</p> <p>Results</p> <p>The total mean score for the three groups of students on the KCAHW questionnaire was 10.67 ± 3.73 out of a possible total score of 19, with medical, nursing and psychology students having total mean scores of 12.24 ± 3.24, 10.76 ± 3.50 and 9.01 ± 3.76 respectively. The mean scores for the three groups showed statistically significant difference for domain 1 (p = 0.000), domain 3 (p = 0.029), domain 4 (p = 0.000) and total score (p = 0.000), with medical students more likely to recognise symptoms and signs of autism compared to nursing and psychology students. The mean score in domain 2 did not show statistically significant difference among the three groups (p = 0.769). The total score on the KCAHW questionnaire is positively correlated with the number of weeks of posting in psychiatry (r = 0.319, p = 0.000) and the number of weeks of posting in paediatrics (r = 0.372, p = 0.000). The total score is also positively correlated with the number of credit hours of lectures in psychiatry/abnormal psychology (r = 0.324, p = 0.000) and the number of credit hours of lectures in paediatrics (r = 0.372, p = 0.000). The field of study also influenced knowledge about childhood autism (p = 0.000).</p> <p>Conclusion</p> <p>Peculiar situation in this environment as signified by inadequate human resources needed in the area of clinical psychology training often times necessitates employing first degree graduates in psychology into clinical positions. This calls for additional exposure of the undergraduate psychology students to training curriculum aimed at improving their early recognition of symptoms of autism spectrum disorders in this environment.</p

Expression of the cytochrome P450s, CYP6P3 and CYP6M2 are significantly elevated in multiple pyrethroid resistant populations of Anopheles gambiae s.s. from Southern Benin and Nigeria

Background: Insecticide resistance in Anopheles mosquitoes is threatening the success of malaria control programmes. This is particularly true in Benin where pyrethroid resistance has been linked to the failure of insecticide treated bed nets. The role of mutations in the insecticide target sites in conferring resistance has been clearly established. In this study, the contribution of other potential resistance mechanisms was investigated in Anopheles gambiae s.s. from a number of localities in Southern Benin and Nigeria. The mosquitoes were sampled from a variety of breeding sites in a preliminary attempt to investigate the role of contamination of mosquito breeding sites in selecting for resistance in adult mosquitoes. Results: All mosquitoes sampled belonged to the M form of An. gambiae s.s. There were high levels of permethrin resistance in an agricultural area (Akron) and an urban area (Gbedjromede), low levels of resistance in mosquito samples from an oil contaminated site (Ojoo) and complete susceptibility in the rural Orogun location. The target site mutation kdrW was detected at high levels in two of the populations (Akron f = 0.86 and Gbedjromede f = 0.84) but was not detected in Ojoo or Orogun. Microarray analysis using the Anopheles gambiae detox chip identified two P450s, CYP6P3 and CYP6M2 up regulated in all three populations, the former was expressed at particularly high levels in the Akron (12.4-fold) and Ojoo (7.4-fold) populations compared to the susceptible population. Additional detoxification and redox genes were also over expressed in one or more populations including two cuticular pre-cursor genes which were elevated in two of the three resistant populations. Conclusion: Multiple resistance mechanisms incurred in the different breeding sites contribute to resistance to permethrin in Benin. The cytochrome P450 genes, CYP6P3 and CYP6M2 are upregulated in all three resistant populations analysed. Several additional potential resistance mechanisms were also identified that warrant further investigation. Metabolic genes were over expressed irrespective of the presence of kdr, the latter resistance mechanism being absent in one resistant population. The discovery that mosquitoes collected from different types of breeding sites display differing profiles of metabolic genes at the adult stage may reflect the influence of a range of xenobiotics on selecting for resistance in mosquitoes

Assessment of knowledge about childhood autism among paediatric and psychiatric nurses in Ebonyi state, Nigeria

<p>Abstract</p> <p>Background</p> <p>There is increasing public and professional awareness of autism spectrum disorders with early recognition, diagnosis and interventions that are known to improve prognosis. Poor knowledge about childhood autism among paediatric and psychiatric nurses who are members of multidisciplinary teams that care for such children may be a major barrier to early interventions that could improve quality of life and prognosis in childhood autism. Factors that influence knowledge about childhood autism among these nurses are not known. This study assessed knowledge about childhood autism among paediatric and psychiatric nurses in Ebonyi state, Nigeria and determined the factors that could be influencing such knowledge.</p> <p>Methods</p> <p>Forty specialist paediatric and forty psychiatric nurses, making a total sample of eighty, were randomly selected from all the health care facilities in Ebonyi state, Nigeria. A socio-demographic questionnaire and knowledge about childhood autism among health workers (KCAHW) questionnaire were administered to them and the study was a point survey.</p> <p>Results</p> <p>The total mean score on the KCAHW questionnaire among the nurses that participated in the study was 12.56 ± 3.23 out of a total of 19 possible. The mean score for the paediatric nurses was 11.78 ± 3.64 while psychiatric nurses had mean score of 13.35 ± 2.58. The mean scores in Domain 1 were 6.17 ± 1.75 for the paediatric nurses and 6.52 ± 1.43 for the psychiatric nurses. The mean scores in Domain 2 were 0.65 ± 0.48 for the paediatric nurses and 0.80 ± 0.41 for the psychiatric nurses. Domain 3 showed mean scores of 1.97 ± 1.25 for the paediatric nurses while psychiatric nurses scored 2.62 ± 1.23. Domain 4 yielded the mean scores of 2.97 ± 1.54 and 3.42 ± 0.98 for the paediatric and psychiatric nurses respectively.</p> <p>There was significant relationship between the total mean score on the KCAHW questionnaire for the two groups and the area of specialisation of the nurses (t = -2.23, df = 78, p = 0.03) and there was also significant relationship between previous involvement in managing children with childhood autism as a specialist paediatric or psychiatric nurse and the total mean score on the KCAHW questionnaire (t = 6.90, df = 78, p = 0.00).</p> <p>Conclusion</p> <p>The scores reflect deficits in knowledge about childhood autism among the study cohorts. Paediatric and psychiatric nurses as members of multidisciplinary teams that care for children with childhood autism are expected to provide holistic care and adequate counselling to the families of these children. Unfortunately in this environment, they are not fully equipped with enough knowledge about childhood autism. Education on childhood autism is therefore needed and can be provided through continuing medical education and emphasizing childhood autism in their training curriculum. This will enhance early identification and diagnosis of childhood autism with early interventions that are known to improve prognosis.</p

Childhood autism in a 13 year old boy with oculocutaneous albinism: a case report

<p>Abstract</p> <p>Introduction</p> <p>Hypomelanotic skin disorders like tuberous sclerosis and hypomelanosis of Ito that present with multiple systemic manifestations have been reported in association with childhood autism. Oculocutaneous albinism is another hypomelanotic skin disorder that rarely presents with multiple systemic manifestations. It is infrequently reported in association with childhood autism when compared to tuberous sclerosis and hypomelanosis of Ito.</p> <p>Case presentation</p> <p>This article reports a case of co-morbid childhood autism and oculocutaneous albinism in a 13-year old boy from Nigeria in Sub-Saharan Africa.</p> <p>Conclusion</p> <p>The observation in this case report and in two previous reports which documented association between oculocutaneous albinism and childhood autism both in the affected individuals and families of individuals with childhood autism, raises the question of a possible genetic and clinical association between oculocutaneous albinism and childhood autism. More family and genetic studies into the relationship between oculocutaneous albinism and childhood autism is desirable. This may provide useful clues into the etiology, prevention and management of childhood autism as well as oculocutaneous albinism.</p

The effects of microstructural features on the performance gap in corrosion resistance between bulk and HVOF sprayed Inconel 625

It is commonly observed that there is a performance gap between the corrosion resistance of thermally sprayed coatings and the equivalent bulk material. This is attributed to the significantly modified microstructure of the sprayed coatings. However, currently there is no detailed understanding of which aspects of microstructural modification are primarily responsible for this performance gap. In this work several deliberately microstructurally modified versions of the Ni-based superalloy Inconel 625 were produced. These were subjected to potentiodynamic electrochemical testing in 0.5M H2SO4 to investigate the links between specific microstructural features and electrochemical behaviour. Samples were prepared by high velocity oxy-fuel (HVOF) thermal spraying, laser surface remelting using a high power diode laser and conventional powder sintering. Microstructural features were examined by optical and scanning electron microscopy and X-ray diffraction. Potentiodynamic testing was carried out on the following forms of Inconel 625: wrought sheet; HVOF sprayed coatings; sintered powder compacts; laser melted wrought sheet and HVOF sprayed coatings. Using the corrosion behaviour, i.e. passive current density, of the wrought sheet as a baseline, the performance of different forms of Inconel 625 were compared. It is found that a fine dendritic structure (with associated microsegregation) produced by laser remelting wrought sheet has no significant effect on corrosion performance. Up to 12% porosity in sintered powder samples increases the passive current density by a factor of only around 2. As observed previously, the passive current density of HVOF sprayed coatings is 20 - 40 times greater. However, HVOF coatings subjected to laser surface remelting are found to have a passive current density close to that of wrought material. It is concluded that, whilst porosity in coatings produces some decrease in corrosion resistance, the main contributing factor is the galvanic corrosion of localised Cr-depleted regions which are associated with oxide inclusions within HVOF sprayed samples

Neuro-feedback intervention efficacy for treating children with Autism Spectrum Disorder

This study explored practitioners perceptions of a neuro-feedback intervention in treating children with Autism Spectrum Disorder’s (ASD). Informants were a convenience sample of ten South African neuro-feedback practitioners registered with the Health Professions Council of South Africa (HPCSA). The data on their views on neuro-feedback treatment efficacy, with children with ASD, were collected by means of semi-structured in-depth interviews. Thematic analysis of the data suggest practitioners to perceive neuro-feedback treatment to enhance the social, mood, behaviour, academic life, and family functioning of children with ASD. Additionally, the practitioners perceived neuro-feedback treatment to assist in reducing anxiety among children with ASD