Haemoglobin genotype of children with severe malaria seen at the University of Benin Teaching Hospital, Benin city, Nigeria

Abstract: Introduction: Types of haemoglobin (Hb) genotype have been found to be crucial to the rate of red blood cell parasite invasion, multiplication, and destruction as well as outcome of malaria disease. In a bid to provide more information on the relationship between Hb genotype and level of protection conferred by genotype against severe forms of malaria, this study was undertaken. This is done through evaluation of forms of Hb genotype in children with severe malaria seen in University of Benin Teaching Hospital (UBTH), Benin City. Patients and methods: This crosssectional study was carried out on children (6 - 60 months old) admitted for severe malaria using standard World Health Organization (WHO) guidelines. Diagnosis of malaria was by microscopic demonstration of parasitaemia or serology (in those with negative parasitaemia). Hb genotype was done using the Hb electrophoresis. Results: Ninety-six well nourished children; (56(58.3%) males and 40 (41.7%) females) mean age (± SD) 29.22 ± 16.02 months were recruited for the study. Sixty-eight (73.4%) of the 92 subjects had Hb genotype AA while 24(26.1%) Had abnormal Hb genotype. Prevalence of severe malaria in children with abnormal Hb was 20/24 (83.3%) as against 58/68(85.3%) observed in those with HbAA. Significantly fewer incidence of heavy malaria parasitaemia (3+ and 4+) was observed in children with abnormal Hb genotype. Heavy parasite density was the most important features of severe malaria in children with HbAA (p= 0.013) as against altered sensorium, prostration, and haemoglobinuria in children with abnormal Hb genotype (p = 0.003, 0.041, and 0.023 respectively). Children with HbAA were also about 3 times more likely to die from severe malaria (p = 0.567, O.R = 2.96) when compared with their counterparts with abnormal Hb. Conclusion: Study supports a higher prevalence of severe malaria in children with HbAA when compared with those with abnormal Hb genotype. Altered sensorium, prostration and haemoglobinuria were the significant presenting features of severe malaria in children with abnormal Hb genotype in this study.Key words: children, genotype, haemoglobin, mortality, severe malari

Prevalence of intestinal helminthiasis in children with chronic neurological disorders in Benin city, Nigeria

Background: It is envisaged that the care for the child with chronic neurological disorder (CND) compared with his apparently healthy counter-part may be sub-optimal, predisposing him to increase disease morbidities including intestinal helminthiasis. To evaluate this hypothesis, a comparative cross sectional study was carried out to determine the prevalence, intensity, and specie-specific prevalence of intestinal helminthiasis in children with CND such as cerebral palsy, epilepsy, and mental retardation seen at the University of Benin Teaching Hospital, Benin City between November 2008 and April 2009.  Subjects and Methods: Fresh stool samples from 155 children with CND and from 155 age   and sex matched apparently healthy nursery and primary school children in Benin City, Edo State were analysed using the Kato-Katz technique for the detection of ova of helminths. Results: The prevalence of intestinal helminthiasis in children with CND was 31.0% compared with 19.4% found among the apparently healthy controls (p = 0.03). This prevalence increased with increasing age in both subjects and comparative group. Intensity of infections in both groups was light. Ascaris lumbricoides, Trichuris trichiura and Ancylostoma duedenale were the intestinal helminths isolated in both subjects and control groups. A. lumbricoides alone had the highest specie-specific prevalence in both the subjects (20.0%) and comparative groups (15.5%). Mixed infection was found only among the children with CND. Conclusion: Intestinal helminthiasis is common and more prevalent in children with CND than in healthy children. It is recommended that regular de-worming be incorporated into the routine care of children with CND.Key words: chronic neurological disorders, helminthiasis, intestinal helminths, intensit

Compromiso con el trabajo y rendimiento en el trabajo: el papel moderador del apoyo organizacional percibido.

The present research was aim to examine whether the relationship between work engagement and objective task performance is moderated by perceived organizational support (POS). Based on the existing literature, perceived organizational support is hypothesized to strengthen the positive association between employees’ work engagement and their objective task performance. The hypotheses were tested on a sample of 1049 employees. Results of hierarchical regression analysis show that: (1) work engagement is positively related to objective task performance, and (2) the relationship between work engagement and objective task performance is moderated by POS, such that the positive relationship is more significant when POS higher than lower. In the end, theoretical and practical implications, and suggestions for future research are discussed.La presente investigación tuvo el objetivo de examinar si la relación entre compromiso con el trabajo y el rendimiento en los objetivos de las tareas está moderada por el apoyo perceptivo de la organización (APO). En base a la literatura existente, el apoyo percibido de la organización se hipotetiza que fortalece la asociación positiva entre el compromiso laboral de los empleados y su rendimiento en los objetivos de las tareas. Las hipótesis fueron comprobadas en una muestra de 1049 empleados. Los resultados del análisis de regresión jerárquico muestran que: (1) el compromiso en el trabajo está positivamente relacionado con el rendimiento en los objetivos de las tareas, y (2) la relación entre compromiso en el trabajo y el rendimiento en los objetivos de las tareas está moderado por el APO, de modo que la relación positiva es más significativa cuando el APO es mayor. Al final se discuten las implicaciones teóricas y prácticas, y las sugerencias para futuras investigaciones

The Formation History of Subhalos and the Evolution of Satellite Galaxies

Satellites constitute an important fraction of the overall galaxy population and are believed to form in dark matter subhalos. Here we use the cosmological hydrodynamic simulation TNG100 to investigate how the formation histories of subhalos affect the properties and evolution of their host galaxies. We use a scaled formation time ($a_{\rm nf}$) to characterize the mass assembly histories of the subhalos before they are accreted by massive host halos. We find that satellite galaxies in young subhalos (low $a_{\rm nf}$) are less massive and more gas rich, and have stronger star formation and a higher fraction of ex situ stellar mass than satellites in old subhalos (high $a_{\rm nf}$). Furthermore, these low $a_{\rm nf}$ satellites require longer timescales to be quenched as a population than the high $a_{\rm nf}$ counterparts. We find very different merger histories between satellites in fast accretion (FA, $a_{\rm nf}1.3$) subhalos. For FA satellites, the galaxy merger frequency dramatically increases just after accretion, which enhances the star formation at accretion. While, for SA satellites, the mergers occur smoothly and continuously across the accretion time. Moreover, mergers with FA satellites happen mainly after accretion, while a contrary trend is found for SA satellites. Our results provide insight into the evolution and star formation quenching of the satellite population.Comment: 21 pages, 10 figures, accepted for publication in Ap

Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters

Spatial modes have received substantial attention over the last decades and are used in optical communication applications. In fiber-optic communications, the employed linearly polarized modes and phase vortex modes carrying orbital angular momentum can be synthesized by fiber vector eigenmodes. To improve the transmission capacity and miniaturize the communication system, straightforward fiber vector eigenmode multiplexing and generation of fiber-eigenmode-like polarization vortices (vector vortex modes) using photonic integrated devices are of substantial interest. Here, we propose and demonstrate direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters. By exploiting vector vortex modes (radially and azimuthally polarized beams) generated from silicon microring resonators etched with angular gratings, we report data-carrying fiber vector eigenmode multiplexing transmission through a 2-km large-core fiber, showing low-level mode crosstalk and favorable link performance. These demonstrations may open up added capacity scaling opportunities by directly accessing multiple vector eigenmodes in the fiber and provide compact solutions to replace bulky diffractive optical elements for generating various optical vector beams