Band gap engineering in finite elongated graphene nanoribbon heterojunctions: Tight-binding model

A simple model based on the divide and conquer rule and tight-binding (TB) approximation is employed for studying the role of finite size effect on the electronic properties of elongated graphene nanoribbon (GNR) heterojunctions. In our model, the GNR heterojunction is divided into three parts: a left (L) part, middle (M) part, and right (R) part. The left part is a GNR of width $W_{L}$, the middle part is a GNR of width $W_{M}$, and the right part is a GNR of width $W_{R}$. We assume that the left and right parts of the GNR heterojunction interact with the middle part only. Under this approximation, the Hamiltonian of the system can be expressed as a block tridiagonal matrix. The matrix elements of the tridiagonal matrix are computed using real space nearest neighbor orthogonal TB approximation. The electronic structure of the GNR heterojunction is analyzed by computing the density of states. We demonstrate that for heterojunctions for which $W_{L} = W_{R}$, the band gap of the system can be tuned continuously by varying the length of the middle part, thus providing a new approach to band gap engineering in GNRs. Our TB results were compared with calculations employing divide and conquer rule in combination with density functional theory (DFT) and were found to agree nicely.Comment: arXiv admin note: text overlap with arXiv:1404.249

Development of a Secured Information System to Manage Malaria Related Cases in South Western region of Nigeria

Effective community based management of malaria incidences in most community health care centers are hampered by failure in the prompt diagnosis and treatment of malaria. This challenge is exacerbated by the emergence of multidrug resistant plasmodium parasites which makes ineffective most of the effective therapeutic drugs used in the treatment of malaria. Furthermore, even at abrupt changes in the therapeutic recommendations does not always translate to an immediate change in the effective management and control of malaria. Thus, the quest for effective diagnosis and appropriate treatment becomes a daunting and necessary task. . In this article, a secured Information system to manage malaria related cases was developed by 2-tier architecture by using the VB.NET programming language within the Microsoft Visual studio 2008 edition. The database employed for storing relevant data was the SQL server 2005 edition and fingerprint device integrated into the information system was the Microsoft fingerprint reader. From the results in this study, we modeled a feasible medical history system for prompt diagnosis, effective drug recommendations and promulgation of policies that would serve as palliatives for community health care centers that suffers shortages in material and human resources handling malaria and its related diseases

Parental Communication as a Tool Kit for Preventing Sexual Abuse among Adolescent Secondary School Students

This study employed the survey design to investigate the relevance of parent communication in preventing sexual abuse among secondary school students in Nigeria. The instrument for data collection tagged “Parent Communication Strategy for Preventing Sexual Abuse questionnaire” (PCOSPSAQ) , was a researcher designed instrument. It was administered to 686 respondents(266 male and 420 female) 500 and 400 sandwich undergraduates of the University of Ado Ekiti, Ekiti State who were parents to adolescent secondary school students. Mean scores were used to answer the research question while t test and Analysis of Variance (ANNOVA) were used to test the six null hypotheses at .05 alpha level. Findings reveal parents’ irresponsibility, ignorance of sexual abuse signs as well as inability to see and stop sexual abuse before it happens as part of the reasons for showing reluctance to communicate with their adolescents on sexual matters. Findings also reveal no significant difference in parents’ pattern of communication on prevention of sexual abuse based on gender, religion and type of family, but significant difference was found on type of parenting and geo political zones. Recommendations include the need for government and nongovernmental organizations to provide adults and parents resources that could boost their awareness on the things they need do to prevent sexual abuse of their adolescent boys and girls. Keywords:  Communication, Parents, Adolescents, Sexual Abuse Prevention

Ethical Issues and Standards of Responsible Research Conduct and Monitoring in an Adventist Institution of Higher Learning - The Babcock Experience

Ethical issues and standards of responsible research conduct involving human participants are important considerations in any institution of higher learning and in particular Adventist institutions. Research conduct and ethics are reviewed and approved before they begin by the Babcock University Health Research Ethics Committee (BUHREC

Mycological, toxigenic and nutritional characteristics of some vended groundnut and groundnut products from three Northern Nigerian ecological zones

Groundnut (Arachis hypogaea L.) and groundnut products are important, street-vended, energy-rich sources of protein and oils useful in human and animal diets although fraught with microbial contaminations. Fungi associated with vended samples of roasted groundnut, Kulikuli, Donkwa, peanut butter and Yaji obtained from Kano, Kaduna, Minna and Ibadan were isolated using pour-plate method. These were qualitatively screened for presence of mycotoxin on palm kernel agar medium and the concentrations of aflatoxin and deoxynivalenol content in the samples quantified through immunoassay. The fungal load of the samples was highest between 1.3X103 and 1.6X104 TFU/g while the frequency of occurrence of Aspergillus, Fusarium, Rhizopus and Penicillium species in the samples were 36%, 33%, 20% and 11%, respectively. Qualitatively, the highest aflatoxin intensity producers were two strains of Aspergillus flavus from a Yaji and Kulikuli sample. The highest aflatoxin concentration (115ppb) was recorded in the Kaduna Yaji sample and 65% of the samples had aflatoxin concentration above the FDA-prescribed 20ppb. The highest deoxynivalenol concentration (0.7ppm) was recorded in Kaduna Donkwa sample which was still lower than the 1.0ppb prescribed recommendation. Kano Yaji and Kaduna Kulilkuli had the highest protein content (60% and 44% respectively) while all samples were high in calcium and potassium (725.16-1292.75 and 325-1280mg/100g) respectively. There was fungal contamination of vended groundnut product samples and the detection of mycotoxins in all the samples. Regulatory bodies, especially in developing countries, need to set quality standards and ensure compliance of the same in street vended food products for product and consumer safety.Keywords: Groundnut products, Mycotoxigenic properties, Deoxynivalenol, Aflatoxin, Nutritional compositionAfr. J. Biomed. Res. Vol. 22 (January, 2019); 65- 7

Genome-wide linkage analysis of age at onset of alcohol dependence: a comparison between microsatellites and single-nucleotide polymorphisms

BACKGROUND: Using the dataset provided for Genetic Analysis Workshop 14 by the Collaborative Study on the Genetics of Alcoholism, we performed genome-wide linkage analysis of age at onset of alcoholism to compare the utility of microsatellites and single-nucleotide polymorphisms (SNPs) in genetic linkage study. METHODS: A multipoint nonparametric variance component linkage analysis method was applied to the survival distribution function obtained from semiparametric proportional hazards model of the age at onset phenotype of alcoholism. Three separate linkage analyses were carried out using 315 microsatellites, 2,467 and 9,467 SNPs, spanning the 22 autosomal chromosomes. RESULTS: Heritability of age at onset was estimated to be approximately 12% (p < 0.001). We observed weak correlation, both in trend and strength, of genome-wide linkage signals between microsatellites and SNPs. Results from SNPs revealed more and stronger linkage signals across the genome compared with those from microsatellites. The only suggestive evidence of linkage from microsatellites was on chromosome 1 (LOD of 1.43). Differences in map densities between the two sets of SNPs used in this study did not appear to confer an advantage in terms of strength of linkage signals. CONCLUSION: Our study provided support for better performance of dense SNP maps compared with the sparse mirosatellite maps currently available for linkage analysis of quantitative traits. This better performance could be attributable to precise definition and high map resolutions achievable with dense SNP maps, thus resulting in increased power to detect possible loci affecting given trait or disease

Comparative study of cervical-vaginal microbial flora changes in women using Cu-T380A contraceptive device and LNG-IUS in Ibadan: a two-centre clinical COHORT study

Background: Intrauterine devices cause various changes in the female genital tract which might result in altered microbial flora and risk of genital infections. The aim of this study was to determine the change in bacterial flora of women using Copper-bearing T380A and levonorgestrel intrauterine system and the risk of genital infections.Methods: This was a two-center clinical cohort study of women using Cu-T380A IUD and LNG-IUS in Ibadan, Nigeria. The study was conducted from March to August, 2016 and it involved 130 women (66 Cu-T380A and 64 LNG-IUS) at 2 family planning clinics in Ibadan, Nigeria. The clients were clinically assessed before admission into the study and high vaginal and endocervical swabs were taken before insertion of the devices, and at 3 and 6months after insertion.Results: Fifty-seven clients with LNG and 63 with copper T380A completed the study. The mean age in LNG-IUS was 34.4years (SD= 6.3) and Cu-T380A was 35.4 years (SD=5.6). All participants had one sexual partner. There was no previous or current STIs/PID at recruitment. The organisms isolated included coagulase negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus spp, Escherichia coli, Candida spp, Neisseria gonorrhoeae and Klebsiella spp. Cu-T380A women had an increase or persistence of CNS, Staphylococci, Klebsiella and Candida at 3 months while in the LNG-IUS group only CNS increased. The HVS revealed that participants with Cu-T380A had higher risks (33.3%) for asymptomatic genital infections than the LNG-IUS (5.3%) group at 6 months (p value <0.001).Conclusions: Cu-T380A has a higher likelihood of altering the microbial flora in the cervix and vagina and therefore encouraging the growth of a variety of other organisms compared to LNG-IUS