Development of a New Drag Coefficient Model for Oil and Gas Multiphase Fluid Systems

Multiphase flows involving suspensions of solid particles are frequently encountered in many industrial processes including oil & gas production. In order to transport solid entrained multiphase fluids, especially through a pipeline, the fluids must be capable of suspending the entrained solid particles to prevent solid deposition and flow assurance challenges. The particle drag coefficient, CD, is a key hydrodynamic parameter, and its effective determination is critical to ensuring effective transportation of the particles. In this work, the results of laboratory measurements of the terminal settling velocity of sand particle(s) in multiphase fluids are presented. The results allow the proper determination of the particle(s) Reynolds number, CD. The developed CD model is an improvement on existing models, which can be applied to both the turbulent and laminar flow regions, thus, reasonably predicting CD over a wide range of Rep­ in multiphase fluid flow. It effectively accounts for the complexities associated with multiphase flow in pipes, and has the potential to solve the problem of sand depositions, and thus, minimizing flow assurance challenges in multiphase flow.http://dx.doi.org/10.4314/njt.v34i2.10

Antigenic modulation in Bordetella pertussis

Summary available: p. ii

The Norm Life Cycle Theory and The Role of INSOL International in Shaping the Uncitral Model Law on Cross-Border Insolvency

The involvement of non-state entities in global public norm evolution has been the subject of many studies, especially in international human rights law and policy. This study explains the role of a non-state entity, INSOL International, in shaping the UNCITRAL Model Law on Cross-Border Insolvency, adopted by the UN General Assembly in 1997 using the life cycle approach developed in the human rights and policy context. The study utilized a triangulation of doctrinal, empirical and legal history data to determine whether the norm life cycle theory could explain the role of INSOL in shaping the Model Law. The study found that non-state entities have influenced bankruptcy norms even before Roman Times. State involvement in setting bankruptcy norms is a reasonably recent phenomenon. The Model Law results from a complex and complicated private-public legal ordering in which non-state entities' interests intermingle with state sovereigns, providing legitimacy and accountability to multilateral normative sites. The life cycle approach enabled a look back on how INSOL manoeuvred the policy terrain to generate, cascade and ensure internalization of cooperation and coordination norms among state courts. These norms underpin the Model Law. The study found that a gap exists between the interests of non-state entities and low GDP states excluded from participation at the two earlier stages of emergence and cascade but required to diffuse the norm at the last stage of internalization. The study indicates that while the life cycle theory is helpful in our understanding of the role of INSOL in shaping the Model Law provides no solution for dealing with the gaps in normative weight of states in global lawmaking. Given the impact of non-state entities on global lawmaking, the study suggests balancing the gaps through the early involvement of members from low GDP states in the activities of non-state entities and at the early stages of the life cycle of a norm. This approach would render internalization and diffusion of such norms easier in those states later

Perceptions and opinions of Nigerians to the management and response to COVID-19 in Nigeria

Introduction: we present a qualitative analysis of opinions of the Nigerian public as to how successful healthcare strategies have been, in containing the COVID-19 outbreak. Methods: an online qualitative survey was conducted, consisting of 30 semi-structured questions. Results: four hundred and ninety-five (495) respondents participated, ranging in age from 18 to 59 years. Over 40% of all respondents were critical of public health information. Participants saw provision of social support measures (n = 83), lack of economic, financial and social support (n = 65), enforcement of restrictions on movement outside the home, availability of face-masks and social distancing (n = 53) and provision of COVID-19 testing (n = 48) as the major things that were handled poorly by the government and health authorities. Conclusion: we advocate coordinated forward planning for public safety until vaccines are widely available; while social distancing should continue. Policymakers need to be adaptable to changing conditions, given fluctuating case numbers and fatality rates

T-Lymphocyte Subsets in Apparently Healthy Nigerian Children

Population studies showed that there are differences in T-lymphocytes subpopulation of normal children in different regions, and reference values in an area might be different from another. This study compared the values in our population with CDC and WHO reference values. Blood samples from 279 healthy, HIV-negative children <12 years of age were analysed for complete blood count, CD3+, CD4+, CD8+ counts and percentages. Except for CD8%, mean values for all parameters measured significantly decreased with age. CD4+ counts were higher in females than males, P < .05. Using the WHO criteria, 15.9% of subjects had low total lymphocyte count and 20.6% had low CD4 count. Children <3 years had median CD4% lower than WHO normal values. Our median CD4+ counts correlated with CDC values. Values used by WHO in infants are higher than ours. We suggest that our children be assessed using CDC reference values which correlate with ours

Whole-genome sequencing illuminates the evolution and spread of multidrug-resistant tuberculosis in Southwest Nigeria.

Nigeria has an emerging problem with multidrug-resistant tuberculosis (MDR-TB). Whole-genome sequencing was used to understand the epidemiology of tuberculosis and genetics of multi-drug resistance among patients from two tertiary referral centers in Southwest Nigeria. In line with previous molecular epidemiology studies, most isolates of Mycobacterium tuberculosis from this dataset belonged to the Cameroon clade within the Euro-American lineage. Phylogenetic analysis showed this clade was undergoing clonal expansion in this region, and suggests that it was involved in community transmission of sensitive and multidrug-resistant tuberculosis. Five patients enrolled for retreatment were infected with pre-extensively drug resistant (pre-XDR) due to fluoroquinolone resistance in isolates from the Cameroon clade. In all five cases resistance was conferred through a mutation in the gyrA gene. In some patients, genomic changes occurred in bacterial isolates during the course of treatment that potentially led to decreased drug susceptibility. We conclude that inter-patient transmission of resistant isolates, principally from the Cameroon clade, contributes to the spread of MDR-TB in this setting, underscoring the urgent need to curb the spread of multi-drug resistance in this region

The 4 youth by youth HIV self-testing crowdsourcing contest: A qualitative evaluation.

INTRODUCTION: Crowdsourcing, a participatory approach to solicit ideas from a large group of diverse individuals, provides an opportunity to nurture youth participation in HIV self-testing service design. The objective of this study was to describe the responses to a crowdsourcing contest aimed at soliciting ideas on how to promote HIV self-testing (HIVST) among young people in Nigeria. METHODS: The "4 Youth by Youth" HIV Self-Testing Crowdsourcing contest was an online and off-line contest that asked Nigerian youth (10-24 years old) for ideas in response to the following: How might we promote HIVST among young people in Nigeria? All data were collected and analyzed between October 2018, and June 2019. Ideas and perceptions generated from the crowdsourcing contest were qualitatively analyzed using thematic content analysis. Specifically, four reviewers analyzed whether the ideas generated were desirable (appealing to young people), feasible (easy to implement) and impactful (will significantly influence HIVST uptake among young people). RESULTS: A total of 903 entries were received in response to the contest prompt. Participants submitted entries in various forms: online form (39.7%), offline Dropbox (44.6%), email (6.1%) and WhatsApp (9.7%). Of the total entries, 85% (n = 769/903) entries were eligible and were scored as having either high, moderate or low level of feasibility, impact and desirability, on a 3-point Likert scale. A significant portion of the entries were given a score of 3 for feasibility (4.9%), desirability (7.1%), impact (3.0%) or a total overall score of 7 or more (8.2%). The three main themes that emerged from the entries include:1) Peer-to-peer distribution and leveraging on existing infrastructures 2) Youth-Oriented Branding of the HIVST Kit 3) Mobile platforms and social media technology. CONCLUSION: The "4 Youth by Youth" Self-Testing contest engaged a broad audience of young people to generate ideas and perspectives on how to promote HIVST. This process informed the development of youth innovated implementation strategies to increase uptake of HIVST among adolescents and youth at risk for HIV

Technology in Massachusetts Schools, 2004-2005

BACKGROUND:ATCC HIV-1 drug resistance test kit was designed to detect HIV-1 drug resistance (HIVDR) mutations in the protease and reverse transcriptase genes for all HIV-1 group M subtypes and circulating recombinant forms. The test has been validated for both plasma and dried blood spot specimen types with viral load (VL) of ≥1000 copies/ml. We performed an in-country assessment on the kit to determine the genotyping sensitivity and its accuracy in detecting HIVDR mutations using plasma samples stored under suboptimal conditions. METHODS:Among 572 samples with VL ≥1000 copies/ml that had been genotyped by ViroSeq assay, 183 were randomly selected, including 85 successful genotyped and 98 unsuccessful genotyped samples. They were tested with ATCC kits following the manufacturer's instructions. Sequence identity and HIVDR patterns were analysed with Stanford University HIV Drug Resistance HIVdb program. RESULTS:Of the 183 samples, 127 (69.4%) were successfully genotyped by either method. While ViroSeq system genotyped 85/183 (46.5%) with median VL of 32,971 (IQR: 11,150-96,506) copies/ml, ATCC genotyped 115/183 (62.8%) samples with median VL of 23,068 (IQR: 7,397-86,086) copies/ml. Of the 98 unsuccessful genotyped samples with ViroSeq assay, 42 (42.9%) samples with lower median VL of 13,906 (IQR: 6,122-72,329) copies/ml were successfully genotyped using ATCC. Sequence identity analysis revealed that the sequences generated by both methods were >98% identical and yielded similar HIVDR profiles at individual patient level. CONCLUSION:This study confirms that ATCC kit showed greater sensitivity in genotyping plasma samples stored in suboptimal conditions experiencing frequent and prolonged power outage. Thus, it is more sensitive particularly for subtypes A and A/G HIV-1 in resource-limited settings

A systematic review of randomized control trials of HPV self-collection studies among women in sub-Saharan Africa using the RE-AIM framework.

INTRODUCTION: Self-collection of samples for HPV testing may increase women's access to cervical cancer screening in low- and middle-income settings. However, implementation remains poor in many regions. The purpose of this systematic review was to examine implementation data from randomized controlled trials evaluating human papillomavirus (HPV) self-collection testing among women in sub-Saharan Africa using the RE-AIM (Reach, Efficacy/Effectiveness, Adoption, Implementation, and Maintenance) framework. METHODS: We searched four electronic databases (PubMed, CINAHL, Web of Science, and Global Health) for pragmatic randomized controlled trials that promote HPV self-collection among women in sub-Saharan Africa. Study selection and data extraction were conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) checklist. Two researchers independently extracted information from each article using a RE-AIM data extraction tool. The reporting of RE-AIM dimensions was summarized and synthesized across included interventions. RESULTS: We identified 2008 citations, and eight studies were included. These reported on five unique interventions. The five interventions were conducted in five countries: Cameroon, Ethiopia, Kenya, Nigeria, and Uganda. Intervention reach (80%) was the most commonly reported RE-AIM dimension, followed by adoption (56%), efficacy/effectiveness (52%), implementation (47%), and maintenance (0%). All the interventions described increased uptake of HPV testing among study participants (effectiveness). However, the majority of the studies focused on reporting internal validity indicators such as inclusion criteria (100%) and exclusion criteria (100%), and few reported on external validity indicators such as participation rate (40%), intervention cost (40%), staff selection (20%), and cost of maintenance (0%). CONCLUSIONS: Our review highlights the under-reporting of external validity indicators such as participation rate, intervention, and maintenance costs in studies of self-collection for HPV testing among women in SSA. Future research should focus on including factors that highlight internal validity factors and external validity factors to develop a greater understanding of ways to increase not only reach but also implementation and long-term maintenance of these interventions. Such data may advance the translation of HPV interventions into practice and reduce health disparities in SSA. Findings highlight the need for innovative tools such as participatory learning approaches or open challenges to expand knowledge and assessment of external validity indicators to ultimately increase the uptake of HPV testing among women in SSA

Possible Impact of Co-infections of Tuberculosis and Malaria on the CD4+ Cell Counts of HIV Patients in Nigeria

Background: This study focused on evaluating the possible impact of co-infections of tuberculosis and malaria on the CD4+ cell counts in HIV infected subjects. Methods: This is a cross sectional study. The subjects were drawn from three hospitals and a blood bank in LagosState. After due consent, blood samples were obtained from 69 subjects with single infections (HIV, TB, and Malaria), 34 subjects with multiple infections (HIV/Malaria, HIV/TB, Malaria/TB, HIV/TB/Malaria) and 24 blood donors (controls). The CD4+ cell counts of all the 127 blood samples were estimated using a FACS count. Results: Data obtained were analysed and a comparison of the results showed that the median CD4+ counts in all groups of subjects with HIV infections (whether single or co-infection) were similar and significantly lower than the median counts for the healthy control group as well as groups without HIV infection (malaria, TB and malaria/TB). Conclusion: Overall data further confirmed the progressive depletion of CD4+ cells in HIV infection while co-infections with TB and malaria did not have any impact on the CD4+ cells of HIV infected subjects. A larger prospective study is needed.Fond: Cette \ue9tude a \ue9t\ue9 consacr\ue9e \ue1 l'\ue9valuation de l'impact possible de co-infections de tuberculose et le paludisme sur les comptes de cellule CD4+ des sujets infect\ue9s du VIH. M\ue9thode: Ceci est une \ue9tude transversale. Les sujets ont \ue9t\ue9 choisis de trois diff\ue9rents h\uf4pitaux et une banque du sang dans l'Etat de Lagos. Apr\ue8s le consentement n\ue9cessaire, les \ue9chantillons de sang ont \ue9t\ue9 obtenus de 69 sujets avec les mono-infections (VIH, TB, et le Paludisme), 34 sujets avec les infections multiples (le VIH/PALUDISME, LE VIH/TB, LE Paludisme/TB, VIH/TB/le Paludisme) et 24 donneurs de sang (les contr\uf4les). les comptes de cellule CD4+ de tous les 127 \ue9chantillons de sang ont \ue9t\ue9 estim\ue9s utilisant une compte FACS. R\ue9sultats: les donn\ue9es obtenues ont \ue9t\ue9 analys\ue9es et une comparaison des r\ue9sultats a d\ue9montr\ue9 que le m\ue9dian des comptes CD4+ dans tous les groupes de sujets avec les infections de VIH (soit mono ou co-infection) \ue9taient similaires et significativement plus bas que les comptes m\ue9dianes pour le groupe de contr\uf4le sain de m\ueame que les groupes sans l'infection de VIH (le paludisme, TB et le paludisme/TB). Conclusion: les donn\ue9es g\ue9n\ue9rales ont confirm\ue9 le plus l'\ue9puisement progressif des cellules CD4+ dans l'infection de VIH pendant que les co-infections avec TB et le paludisme n'ont pas eu aucun impact sur les cellules CD4+ des sujets infect\ue9s de VIH. Une plus profonde \ue9tude sera n\ue9cessaire