MODIFIED TRAFFIC SIGNAL PHASING AT TRAFFIC WARDEN CONTROLLED INTERSECTION TO ACCOMMODATE PEDESTRIAN TRAFFIC IN ILORIN METROPOLIS, NIGERIA

The study addresses the nervous anxiety always noticed in pedestrians as they cross at a 4-arm, Traffic Warden Control intersection in Ilorin metropolis, Nigeria. Two of the approaches (Challenge and Unity) are dualised multilanes while the other two (Obbo and CocaCola) are two-lane non-dualised. The present 4-phase traffic control scheme does not give consideration to pedestrian crossing. The geometric layout and the existing traffic management practice at the intersection were determined and a pedestrian traffic survey was conducted. The critical pedestrian volume of 171 pedestrians/hr was obtained on Challenge approach. Using an average walking speed of 1.2 m/s and a crosswalk width of 3 m a pedestrian crossing time of 787.88 seconds within one hour is obtained as being adequate for the critical approach.  A 5-phase scheme is proposed with the fifth phase being an all-stop exclusive phasing for pedestrian movements. Crosswalk should be introduced to concentrate pedestrian crossing activity at a specific location thereby positioning pedestrians to be more visible to traffic wardens and motorists.  http://dx.doi.org/10.4314/njt.v35i1.

THE FACTORS THAT AFFECT THE FREE FLOW SPEED ON AN ARTERIAL IN ILORIN, NIGERIA

 Generic factors (weather, environment, vehicles, fixed roadway characteristics, pedestrian and traffic streams) singly or jointly influence the free flow speed. This paper, therefore, presents the outcome of the quantitative evaluation of the influence of these factors on the free flow speed on an arterial in a medium-sized urban settlement in Nigeria. Instantaneous speeds of forty test vehicles were observed at lull periods on the 7.1km-Offa Garage-Emir’s Road, Ilorin, with simultaneous collection of data on drivers’ and vehicle ages, passenger occupancy, roadside parked vehicles and businesses. The geometric properties of the arterial were earlier established and segmented to four uniform sections. Result of computations using the category and statistical analysis show that the environment, pedestrian and roadway geometry have negative influences on the free flow speed. This can be confirmed by the poor relationship between free flow speed and these factors, with R2 values of 14.9-55%, and lower average free flow speed of commercial saloon cars on wet pavement than on dry pavement, with 12% percentage reduction. Adoption of design and analysis of traffic stream in Ilorin and other urban settlements in Nigeria is, therefore, recommended. http://dx.doi.org/10.4314/njt.v35i3.

RESEARCH EFFORTS ON INTELLIGENT TRANSPORTATION SYSTEM IN NIGERIA: DEVELOPMENT OF TRIP PLANNING MODELS

The critical situation of unwelcome frustration experienced by urban trip makers and roadside dwellers alike, calls for a very strong push by all stakeholders in the transportation sector to enhance the service performance of transportation facilities using Intelligent Transportation Systems (ITS). Needed strategies for successful ITS implementation in both developed and developing nations, include but not limited to policy formulation and planning, funding of ITS projects, development and deployment of research products, system performance measurement, optimization of the performance of existing infrastructure, capacity building, etc. which could be much promoted with research efforts. Advanced Public Transportation System (APTS) and Advanced Traveller Information System (ATIS) categories as products of research on ITS were developed with data derived from urban trip makers on captive corridors, both in Ilorin, Kwara State and Minna, Niger State, Nigeria. The fundamental basis and status of the research activities targeted at developing and deploying the ITS in Nigeria are highlighted in the paper. http://dx.doi.org/10.4314/njt.v35i3.

The only African wild tobacco, Nicotiana africana: Alkaloid content and the effect of herbivory

Herbivory in some Nicotiana species is known to induce alkaloid production. This study examined herbivore-induced defenses in the nornicotine-rich African tobacco N. africana, the only Nicotiana species indigenous to Africa. We tested the predictions that: 1) N. africana will have high constitutive levels of leaf, flower and nectar alkaloids; 2) leaf herbivory by the African bollworm Helicoverpa armigera will induce increased alkaloid levels in leaves, flowers and nectar; and 3) increased alkaloid concentrations in herbivore-damaged plants will negatively affect larval growth. We grew N. africana in large pots in a greenhouse and exposed flowering plants to densities of one, three and six fourth-instar larvae of H. armigera, for four days. Leaves, flowers and nectar were analyzed for nicotine, nornicotine and anabasine. The principal leaf alkaloid was nornicotine (mean: 28 µg/g dry mass) followed by anabasine (4.9 µg/g) and nicotine (0.6 µg/g). Nornicotine was found in low quantities in the flowers, but no nicotine or anabasine were recorded. The nectar contained none of the alkaloids measured. Larval growth was reduced when leaves of flowering plants were exposed to six larvae. As predicted by the optimal defense theory, herbivory had a localized effect and caused an increase in nornicotine concentrations in both undamaged top leaves of herbivore damaged plants and herbivore damaged leaves exposed to one and three larvae. The nicotine concentration increased in damaged compared to undamaged middle leaves. The nornicotine concentration was lower in damaged leaves of plants exposed to six compared to three larvae, suggesting that N. africana rather invests in new growth as opposed to protecting older leaves under severe attack. The results indicate that the nornicotine-rich N. africana will be unattractive to herbivores and more so when damaged, but that potential pollinators will be unaffected because the nectar remains alkaloid-free even after herbivory

Gene sequence variations of the platelet P2Y12 receptor are associated with coronary artery disease

<p>Abstract</p> <p>Background</p> <p>The platelet P2Y₁₂receptor plays a key role in platelet activation. The H2 haplotype of the P2Y₁₂receptor gene (<it>P2RY12</it>) has been found to be associated with maximal aggregation response to adenosine diphosphate (ADP) and with increased risk for peripheral arterial disease. No data are available on its association with coronary artery disease (CAD).</p> <p>Methods </p> <p>The H2 haplotype of the <it>P2RY12 </it>was determined in 1378 unrelated patients of both sexes selected according to the presence of significant coronary artery disease (CAD group) or having normal coronary angiogram at cardiac catheterization (CAD-free group). Significant coronary artery disease was angiographically determined, and was defined as a greater than 50% visually estimated luminal diameter stenosis in at least one major epicardial coronary artery.</p> <p>Results</p> <p>In the studied population 71.9% had CAD (n = 991) and 28.1% had normal coronary angiogram (n = 387). H2 haplotype carriers were more frequent in the CAD group (p = 0.03, OR = 1.36, 95%CI = 1.02–1.82). The H2 haplotype was significantly associated with CAD in non-smokers (p = 0.007, OR = 1.83 95%CI = 1.17–2.87), but not in smokers. The association remained significant after adjustment for other covariates (age, triglycerides, HDL, hypertension, diabetes) by multivariate logistic regression (p = 0.004, OR = 2.32 95%CI = 1.30–4.15).</p> <p>Conclusion</p> <p>Gene sequence variations of the P2Y₁₂receptor gene are associated with the presence of significant CAD, particularly in non-smoking individuals.</p

Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection

<p>Abstract</p> <p>Background</p> <p>MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the <it>Plasmodium falciparum </it>merozoite surface protein 1 (MSP1₁₉), inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP1₁₉had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP1₁₉would affect critical T-cell responses to epitopes in this antigen.</p> <p>Methods</p> <p>The cellular responses to wild-type MSP1₁₉and a panel of modified MSP1₁₉antigens were measured using an <it>in-vitro </it>assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to <it>Plasmodium falciparum </it>infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults.</p> <p>Results</p> <p>Interestingly, stimulation indices (SI) for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP1₁₉. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu) had the highest stimulation index (SI up to 360) and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins.</p> <p>Conclusion</p> <p>This study suggests that specific MSP1₁₉variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.</p

Bone marrow adipose tissue is a unique adipose subtype with distinct roles in glucose homeostasis

Bone marrow adipose tissue (BMAT) comprises >10% of total adipose mass, yet unlike white or brown adipose tissues (WAT or BAT) its metabolic functions remain unclear. Herein, we address this critical gap in knowledge. Our transcriptomic analyses revealed that BMAT is distinct from WAT and BAT, with altered glucose metabolism and decreased insulin responsiveness. We therefore tested these functions in mice and humans using positron emission tomography-computed tomography (PET/CT) with 18F-fluorodeoxyglucose. This revealed that BMAT resists insulin- and cold-stimulated glucose uptake, while further in vivo studies showed that, compared to WAT, BMAT resists insulin-stimulated Akt phosphorylation. Thus, BMAT is functionally distinct from WAT and BAT. However, in humans basal glucose uptake in BMAT is greater than in axial bones or subcutaneous WAT and can be greater than that in skeletal muscle, underscoring the potential of BMAT to influence systemic glucose homeostasis. These PET/CT studies characterise BMAT function in vivo, establish new methods for BMAT analysis, and identify BMAT as a distinct, major adipose tissue subtype

“Hub” Organisations in Kenya: What are they? What do they do? And what is their potential?

From Senegal to Tanzania, and South Africa to Egypt, over the last decade “hub” organisations have proliferated across the African continent. Whilst this rapid growth has been accompanied by increasing academic interest, to date, works examining this phenomenon and this new dynamic organisational form remain limited. This study aims to contribute towards addressing this gap by examining hub organisations in Kenya. More specifically, and drawing upon in-depth qualitative case study research with three hubs, it examines: the nature of hubs in Kenya, what they are; unpacks what they do, and especially the role of hubs as intermediaries; and evaluates the potential of hubs, including as promoters of entrepreneurship, innovation and wider positive social change in Kenya. This research identifies the multiple hybridities of hub organisations in Kenya. It finds that they perform an intermediary role working institutional voids. Finally, both potential and limitations of hubs are identified. This research contributes to hitherto limited work on hubs, especially in Africa, and theorises hubs as hybrid intermediary organisations. It also showcases Africa as an important but still understudied context for management scholarship