Variational quantum monte carlo calculation of the ground state energy of hydrogen molecule

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General Relativistic Equation of Motion for a Photon Moving Round a Time Varying Spherical Distribution of Mass

AbstractIn this article, Schwarzschild metric is extended to obtain a generalized metric for the gravitational field exterior to time varying spherical distributions of mass. Einstein’s equation for photon moving round a time varying spherical distribution of mass is derived. The second-order differential equation obtained is a modification of the equation of motion in Schwarzschild field. It introduces a unique dependence of the motion of the photon in this field on Newton’s scalar potential exterior to time varying spherical bodies

Effect of crude oil extracts on early stages of African catfish Heterobranchus longifilis (val.) reared under controlled condition

Eggs and larvae of Heterobranchus longifilis were exposed to extracts of different concentrations of Nigerian Bonny light crude oil and Exxon Mobil Oso off-shore condensate during a comparative toxicity experiment carried out in the Institute of Oceanography Fish Farm, University of Calabar, Nigeria. Petroleum hydrocarbon was extracted from the two oils in separate 30litre glass aquaria and the eggs and young larvae were contaminated by exposing them to three concentrations of both oils, viz: 101, 103, 102ppm for approximately 10 days. Young eggs seemed to be more sensitive from 5 to 30 hours after fertilization. Extract from 104 ppm of Bonny Light Crude and Oso condensate caused 40% and 30% mortality respectively, after 100h. Embryos contaminated with Bonny Light crude extract did not recover on transfer to clean water. Delayed development was observed in the two-highest concentrations. Heterobranchus longifilis larvae were found to have a “mean critical time” of 4.2 days in the highest concentration of Oso condensate extract when larval integument was damaged. It is concluded that Bonny light crude could be a more dangerous pollutant to juvenile fish than the Oso condensate.KEYWORDS: Heterobranchus longifilis, crude Oil extracts, Mortality, Bonny Light Crude, Exxon MobilOso Condensate

Impact Of Crude Oil On Recruitment Of Epibenthic Organisms In Cross River Estuary, South East Nigeria

Effects of crude oil on recruitment of epibenthic organisms in Cross River estuary were studied in February and March, 2007 on wooden Panels (15×15×1.5cm). The panels were immersed in Nigerian light crude oil and later suspended in the estuary for six weeks. Rhizoclonium hieroglyphicum showed slight resistance to the effect of the crudeoil while species like Balanus balanoide, Crassostrea gazar, Bugula neritina, Serbellaria intoshi, Catenella opuntia and Caloglossa leprieurii showed slight inhibition. Statistically, there was however no significant difference in the recruitment level of the organisms on both the control panels and oil-polluted panels, (p>0.05). This may probably have been as a result of weathering process or bacterial degradation of the crude oil which rapidly diluted the hydrocarbon, thereby reducing its toxicity. The result reveals that widespread oil spill during the reproductive season would reduce larval settlement and impede subsequent recruitment. The ecological implications of these findings arediscussed

Studies on the short-term fffects of the mobil Idoho oil Spill on the Littoral Biota of Southeastern Nigeria

Quantitative surveys of the intertidal macro-fauna were conducted during September-October 1998 along transects established at various locations along the Nigeria coastline, following the rupture of a 24-inch pipeline at Idoho, off the Gulf of Guinea, southeastern Nigeria on 12 January 1998. Samples were taken within impacted areas and at control unpolluted sites approximately 5 km to the east of the Idoho off-shore platform. Spilled oil moved rapidly ashore and into river mouths, and estuaries and their mangals shortly after the spills. Biomass of macrofauna in the impacted areas tended to decrease with level of oiling, as the mean abundance decreased rapidly to about 50% of that found on the control unpolluted sites. Edible gastropod, mainly species of Tympanotomus fuscatus, and the brachyuran decapod, Ucatangeri, typically consumed by coastal inhabitants, had reduction in mean densities (up to 62%) in the oiled Bonny, Brass, Lagos and Forcados than in the non-oiled areas of Imo, Andoni and Cross River, showing partial recovery of the environment from the debacle after 9 months. The ecological implications of these findings are discussed

Effects of crude oil on the gastropod, tympanotomus fuscata in the Cross River Estuary, south-east Nigeria

Edible periwinkle, Tympanotonus fuscata, was collected from the Cross River estuary, allowed to acclimate to laboratory conditions for a week and then exposed to Nigerian light crude oil at different concentrations of 50ml, 100ml, and 150ml per litre of water for a period of 96 hours. Mud (80g) was added to all the 4-litre aquaria used for the experiment. The oil was thoroughly mixed with the estuarine water by stirring vigorously. During the 4-days experimental period, most of the specimens suffered suffocation and became moribund and mortality recorded. Within the first 24 hours mortality was absent in the 50ml and 100ml concentrations, although most specimens moved out of the medium by creeping up the aquaria. Specimens in the control seemed lively and unaffected by oiling throughout the duration of the experiment. Mortalities were as high as 117 out of 180 individuals during the entire experimental period, with higher concentrations recording higher mortalities. There was steady increase in mortality from 4 individuals in the first 24 hours to 12 individuals after 72 hours in the 150ml/l concentration. The LC50 values were obtained by graphical interpolation. It is concluded that the soluble fraction of the Nigerian light crude oil could be detrimental to shellfish even at a concentration as low as 1000ml/l of the estuarine water.KEYWORDS: Crude Oil, Water Soluble Fraction, Tympanotonus fuscata, Cross River estuary, Nigeria

Theoretical basis of allometric relationships in juvenile brachyura: Data from a West African mangrove swamp crab population

The carapace length-weight relationship in juvenile Brachyura (crabs) was studied theoretically to assess the relevance of the allometric factor and the validity of the condition factor as these factors are often not determined because most fishery investigations are conducted for adult population. The allometric factor appears to be the main parameter in the equation: W = aLb (where W = weight, a is a constant and L = carapace length). Parameters a (also called the condition factor K, known as the ponderal index) and k = 103 W/L3 were found to be of less significance and they were closely related to b. The theoretical value of b = 3 was found to be rarely met in crab fishery studies; rather much wider range was observed. It was, therefore, recommended that the assumed theoretical value of b = 3 would not be applied in all ichthiofauna surveys as it is generally commonly done by fishery scientists. The present analytical studies has opened a new approach to the elucidation of the biological significance of the allometric factor b, through the theories of tractal geometry (where b is seen as a fractal dimension equivalent and salutatory ontogeny where b is a critical point in theearly life history of crabs

Ecological implications of allometric growth in Brachyurans: Data from Uca Tangeri resident in a West African mangrove swamp

A survey was carried out on the fiddler crabs present in a small naturally defined mangrove swamp in the upper Bonny Estuary of the Niger Delta (S. Nigeria), the purpose of which was to study the ecological significance of the claws of the Ocypodidae crab, Uca tangeri (Eydoux, 1835). Previous studies on the size of the claws of crabs generally have focused on their use in foraging. In the present investigation, the use of claws in reproduction provides further support to the view that evolution of crab chelae (claws) is not driven by feeding requirement alone. Mating pairs collected in the field showed that > 75% of mating males had chelae above the average size of the male population as a whole. Maintenance costs for cheliped in Uca tangeri estimated by respirometry were not significantly different from other body tissues as oxygen uptake could be predicted solely from dry tissue weight. Moreover, the rate of oxygen uptake was independent of the proportion of the total body weight that could be contributed by the chelipeds. Changes in the allometry of various dimensions at sexual maturity was observed in U. tangeri and suggests a sexual role in the crab.KEYWORDS: Relative growth, Uca tangeri; Claw size, Bonny Esturary

Journal Staff

Primary Immunodeficiencies (PID) are genetically inherited disorders characterized by defects of the immune system, leading to increased susceptibility to infection. Due to the variety of clinical symptoms and the complexity of current diagnostic procedures, accurate diagnosis of PID is often difficult in daily clinical practice. Thanks to the advent of "next generation'' sequencing technologies and target enrichment methods, the development of multiplex diagnostic assays is now possible. In this study, we applied a selector-based target enrichment assay to detect disease-causing mutations in 179 known PID genes. The usefulness of this assay for molecular diagnosis of PID was investigated by sequencing DNA from 33 patients, 18 of which had at least one known causal mutation at the onset of the experiment. We were able to identify the disease causing mutations in 60% of the investigated patients, indicating that the majority of PID cases could be resolved using a targeted sequencing approach. Causal mutations identified in the unknown patient samples were located in STAT3, IGLL1, RNF168 and PGM3. Based on our results, we propose a stepwise approach for PID diagnostics, involving targeted resequencing, followed by whole transcriptome and/or whole genome sequencing if causative variants are not found in the targeted exons