Paediatric HIV/AIDS seen at Ahmadu Bello University Teaching Hospital Zaria, Nigeria

Background: Paediatric HIV/AIDS is an escalating problem of frightening proportion in Nigeria, although not much has been reported from our center. Method: A retrospective study of 35 children with the diagnosis of HIV/AIDS admitted into the Emergency Paediatric Unit (EPU) of Ahmadu Bello University Teaching Hospital (ABUTH) over a 3.4 year period between March 1998 and June 2001 was undertaken in order to determine the most common mode of presentation and also the most prevalent complicating infection among these patients. Results: The mean age of the patients was 2\ub11.8 years (range 2-144 months), with the majority 30 (85.7%) aged three years and below, and a male to female ratio of 2.1:1. The probable mode of infection was vertical in 88.6% patients, through blood transfusion in 8.6%, while the source of infection could not be established in one (2.8%) due to inadequate data. Multiple symptoms at presentation were common with fever and cough being the most frequent, occurring in 82.8% of patients, followed by diarrhea in 71.4% and weight loss in 60.0% of cases. The most common signs were wasting which was found in 74.3%, generalized lymphadenopathy in 68.6% and pyrexia in 54.3%. Commonly diagnosed infections were oral candidiasis, pneumonia and tuberculosis, seen in 60.0%, 45.7% and 31.4% respectively. Nine (25.7%) out of the 35 children died, 7(20.0%) were discharged against medical advice, 19 (54.3%) improved and were discharged to follow up, but all except four have been lost to follow up. Conclusion: Paediatric HIV/AIDS is becoming a major cause of childhood morbidity and mortality in our environment. The prevention of HIV infection in women particularly in the reproductive age group would go a long way in controlling the disease in Nigeria.Introduction: l'Infection \ue0 VIH/SIDA chez les enfants est un probl\ue8me galopant et d'une ampleur effrayante au Nig\ue9ria malgr\ue9 que peu de travaux ont \ue9t\ue9 rapport\ue9s dans notre centre. M\ue9thode: Une \ue9tude r\ue9trospective sur 35 enfants ayant chacun un diagnostic de VIH/SIDA admis au service des urgences p\ue9diatriques du Centre Hospitalier Universitaire Ahmadu Bello (ABUTH ZARIA) pendant une p\ue9riode de 3,4 ans a \ue9t\ue9 r\ue9alis\ue9e en vue de d\ue9terminer le plus fr\ue9quent mode de pr\ue9sentation et la plus fr\ue9quente infection parmi ces malades. R\ue9sultats: la moyenne d'\ue2ge de ces patients \ue9tait de 2\ub11,8 ans (varie entre 2 \ue0 144 mois), avec une majorit\ue9 85,7% \ue2g\ue9e de trois (3) ans ou moins et un rapport homme: femme de 2,1:1. Le mode de transmission probable \ue9tait vertical dans 88,6% des cas, \ue0 travers une transfusion sanguine dans 8,6% des cas et dans 2,8% des cas le mode de transmission n'a pas pu \ueatre \ue9tabli \ue0 cause d'une documentation et des donn\ue9es insuffisantes. Des sympt\uf4mes multiples ont \ue9t\ue9 un mode de pr\ue9sentation commun avec fi\ue8vre et toux constituant les plus fr\ue9quents sympt\uf4mes observ\ue9s chez 29 enfants (82,8%), suivi de la diarrh\ue9e dans 71,4% des cas et perte de poids et d\ue9faillance staturo-pond\ue9rale dans 60,0% des cas. Les signes cliniques les plus fr\ue9quents sont l'amaigrissement observ\ue9 dans 74,3% des cas, les ad\ue9nopathies g\ue9n\ue9ralis\ue9es dans 68,6% des cas et la fi\ue8vre dans 54,3% des cas. Les infections commun\ue9ment diagnostiqu\ue9es chez ces patients sont les candidiases orales, les pneumonies et la tuberculose avec pour incidence respectivement de 60,0%, 45,7% et 31,4%. Neuf (9) enfants sur les 35 admis sont d\ue9c\ue9d\ue9s (25,7%), 7 cas sont sortis de l'h\uf4pital contre la volont\ue9 m\ue9dicale soit 20,0%, 19 enfants (54,3%) se sont am\ue9lior\ue9s et sortis de l'h\uf4pital avec un suivi r\ue9gulier parmi lesquels quatre (4) \ue9taient perdus de vue. Conclusion: L'infection \ue0 VIH/SIDA en p\ue9diatrie devient de plus en plus une cause majeure de morbidit\ue9 et de mortalit\ue9 dans notre environnement. La pr\ue9vention de l'infection \ue0 VIH chez les femmes particuli\ue8rement en \ue2ge de procr\ue9er contribuerait positivement dans la lutte contre cette maladie au Nig\ue9ria

Sensing, measuring and modelling the mechanical properties of sandstone

We present a hybrid framework for simulating the strength and dilation characteristics of sandstone. Where possible, the grain-scale properties of sandstone are evaluated experimentally in detail. Also, using photo-stress analysis, we sense the deviator stress (/strain) distribution at the microscale and its components along the orthogonal directions on the surface of a V-notch sandstone sample under mechanical loading. Based on this measurement and applying a grain-scale model, the optical anisotropy index K0 is inferred at the grain scale. This correlated well with the grain contact stiffness ratio K evaluated using ultrasound sensors independently. Thereafter, in addition to other experimentally characterised structural and grain-scale properties of sandstone, K is fed as an input into the discrete element modelling of fracture strength and dilation of the sandstone samples. Physical bulk scale experiments are also conducted to evaluate the load-displacement relation, dilation and bulk fracture strength characteristics of sandstone samples under compression and shear. A good level of agreement is obtained between the results of the simulations and experiments. The current generic framework could be applied to understand the internal and bulk mechanical properties of such complex opaque and heterogeneous materials more realistically in future