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Search Results: 1 - 10 of 219997 matches for " Akani Godfrey C "
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Negative density dependence of sympatric Hinge-back Tortoises (Kinixys erosa and K. homeana) in West Africa
Luca Luiselli,Francesco M. Angelici,Lorenzo Rugiero,Godfrey C. Akani
Acta Herpetologica , 2008,
Abstract: A series of 59 transect surveys was conducted in selected wet forest habitats, along the coast of West Africa, to estimate the density distribution of African Hinge-back tortoises (Kinixys homeana and K. erosa). Line transect data were fed into a simple model to derive a detection function. The parameters estimated by the model produced an elaborate characterisation of tortoise distribution, which proved to be useful in the formulation of hypotheses about tortoise densities. Line transect data were analysed by DISTANCE, with a series of key and the series adjustment: the uniform function, the 1-parameter half-normal function, and the 2-parameter hazard-rate function were considered as key functions; the cosine series, simple polynomials, and Hermite polynomials were considered as series expansions. The detection function was estimated separately for Kinixys homeana and K. erosa, and for transects grouped for each study area by considering all the combinations of the above key functions and series expansions. The Akaike Information Criterion (AIC) was computed for each candidate model and used for model selection. The best model of the detection function, for both the tortoise species was the uniform function with no series expansion. Model results indicated that the density of the two species was inversely related at the local scale, and complementary across the region; such that the density of one species increases from West to East while the other one declines. Overall, the comparison of density estimates between the two tortoises is consistent with a former hypothesis suggesting inter-specific competition and consequent resource partitioning. Other causes may contribute to explain the observed patterns, including the low productivity of rainforest habitats and long-term human perturbation.
Correlation between annual activity patterns of venomous snakes and rural people in the Niger Delta, southern Nigeria
Akani Godfrey C,Ebere Nwabueze,Franco Daniel,Eniang Edem A
Journal of Venomous Animals and Toxins including Tropical Diseases , 2013, DOI: 10.1186/1678-9199-19-2
Abstract: Background Venomous snakes are among the most serious health hazards for rural people in tropical regions of the world. Herein we compare the monthly activity patterns of eight venomous snake species (Elapidae and Viperidae) with those of rural people in the Niger Delta area of southern Nigeria, in order to identify the periods of highest potential risk for persons, and the human group actually at greater risk of snakebite. Results We documented that above-ground activity of all venomous snakes peaked in the wet season, and that high snake activity and high human activity were most highly correlated between April and August. In addition, we documented that women and teenagers were at relatively higher risk of encountering a venomous snake than adult males, despite they are less often in the field than men. Conclusions Our results suggest that future programs devoted to mitigate the social and health effects of snakebites in the Niger Delta region should involve especially women and teenagers, with ad-hoc education projects if appropriate. We urge that international organizations working on social and health problems in the developing world, such as IRD, DFID, UNDP, should provide advice through specific programs targeted at especially these categories which have been highlighted in comparatively potential higher threat from snakebites than adult men.
Some new mammal records from the rainforests of south-eastern Nigeria
Francesco Angelici,Bomiegha Egbide,Godfrey Akani
Hystrix : the Italian Journal of Mammalogy , 2001, DOI: 10.4404/hystrix-12.1-4169
Abstract: In this paper we report new data on the occurrence and range of seven mammal species in the rainforest region of south-eastern Nigeria. The species in question are: Potamogale velox (Insectivora), Cercopithecus sclateri, Procolobus badius epieni (Primates), Manis tetradactyla (Pholidota), Funisciurus pyrropus talboti (Rodentia), Trichechus senegalensis (Sirenia) and Tragelaphus spekii gratus (Artiodactyla). In terms of conservation (according to latest IUCN criteria and categories), we discovered some critical information concerning the mammal fauna in the area. In fact, out of these seven species, one is Critically Endangered (CR), four are Endangered (EN), one is Lower Risk, least concern (LR, lc), and one is Not Evaluated (NE). Deforestation and excessive hunting pressure are the biggest threats for mammals in the Niger Delta. In particular, endemic taxa and species whose range and status are unknown, could be particularly endangered.
Case Report: Early Neonatal Death Due To Liver Rupture Caused By Maternal Abdominal Manipulation And Massage In Laboour
CNT Amabiri, C Akani
Nigerian Journal of Clinical Practice , 2004,
Abstract: An early neonatal death due to liver to liver rupture caused by maternal abdominal manipulation and massage is presented. An apparently health baby girl was born to 26 years old primigravida who came in the second state of labour and deliver of her baby within eight minutes of arrival to the labour ward. Her labour lasted about 4 hours and she had gone for abdominal manipulation and massaging before coming to hospital. Apgar score at birth was 8 recorded 9 at minutes. The baby was discovered to be very pale about 10 hours delivery, so admitted in the special care baby unit where she died shortly afterwards while being investigated. Relations were aggrieved and had accused the hospital of negligence. The wrote to the hospital to explain the circumstance of the baby\'s death. An autopsy (on the body) revealed massive intro – abdominal haemorrhage resulting form a linear of the lobe of the liver. It was concluded that the massging hands may have ruptured the baby\'s liver and she bled slowly and died of hypovolaemic shock ten hours later. Nigerian Journal of Clinical Practice Vol.7(1) 2004: 41-42
Sero-Epidemiology of hiv infection among abandoned babies in port Harcourt, Nigeria
Akani C,Erhabor O
Annals of African Medicine , 2006,
Abstract: Background : HIV infection is endemic in Nigeria and is an important cause of infant mortality and morbidity. This study was undertaken to determine the sero-epidemiology of HIV among abandoned babies in Port Harcourt, Nigeria. Methods : One hundred and forty (n = 140) consecutively recruited abandoned babies mean age 11.5 ± 24.1 weeks made up to 79 males and 61 females, referred to the HIV screening unit from motherless babies home in Port Harcourt for pre-adoption HIV screening within a five years period (1999– 2003) were screened for HIV using the WHO approved immunocomb HIV I& II kits (Organics, Israel)– an enzyme linked immunosorbent assay for the quantitative and differential diagnosis of HIV in serum or plasma. Initially reactive samples were continued using Genscreen HIV 1& 2 (p24) antigen test (Bro Rad, France). Results :HIV was detected in 19(13.6%) of babies tested. Sero-prevalence was highest in babies 9– 16 weeks (25.0%). Males accounted for the highest infection burden (57.9%) compared to (42.1%) for females. Data indicated that the prevalence of HIV declined from 12.5% in 1999 to 8.3% in 2000 and increased subsequently to 20% in 2001 but declined steadily to 16.1% in 2002 and 14.3% in 2003. HIV-1 accounted for the predominant viral subtype among babies sero-positive for HIV (89.5%). Chi square analysis indicates that symptom at abandonment was an independent risk factor for HIV infection among abandoned babies (χ2 = 40.97; p = 0.0001). Conclusions : This study demonstrates a high prevalence of HIV among abandoned babies in Port Harcourt. This calls for an urgent need for government, non governmental organization and faith-based organization to critically examine the issue of child abandonment and HIV infection by initiating care and support programme aimed at providing knowledge and information which emphasizes a combination of behavioural and social changes and providing a youth-friendly health services to control the HIV scourge.
An indirect assessment of the effects of oil pollution on the diversity and functioning of turtle communities in the Niger Delta, Nigeria
Luiselli, L.,Akani, G. C.
Animal Biodiversity and Conservation , 2003,
Abstract: There are many documented cases of oil spillage in the Niger Delta region, southern Nigeria (West Africa). Due to both habitat characteristics and omnivorous habits, the freshwater turtles are important vertebrates species in the trophic chain. They are therefore considered to play a significant role as ecological indicators for areas subjected to oil spillage events. The aim of this study was to evaluate the effects of oil spillage and consequent pollution on the abundance, complexity and functioning of freshwater turtle communities of the Niger Delta, by comparing the turtle fauna found in two areas with similar environmental characteristics, one unpolluted and the other polluted by a case of oil spillage in 1988. A total of 510 turtle specimens belonging to four different species (Trionyx triunguis, Pelusios castaneus, Pelusios niger, and Pelomedusa subrufa) were captured in the unpolluted area, whereas 88 specimens, from two different species (P. castaneus and P. niger) were captured in the polluted area. The dominant species was P. castaneus followed by P. niger in the unpolluted area, and P. niger in the polluted area. A marked shift in habitat use was observed in one species (P. niger) after the oil spillage event. This study revealed both direct and indirect effects of oil pollution on the complexity and habitat use of Nigerian freshwater communities of turtles. The main direct effect was a considerable reduction in the specific diversity of the turtles; 50% of species were lost after oil spillage and there was a very strong decline in the numbers of turtle specimens also for those species which were able to survive the catastrophic pollution event. The shift in habitat use after oil spillage by P. niger may have a significant effect on the long-term persistence of this species, independently of the pollution effects of the oil spillage event, because it considerably reduced habitat niche separation between this species and the closely related P. castaneus, a potential competitor. It is therefore stressed that eco-ethological modifications in populations of animals subjected to catastrophic events such as oil pollution should be taken into account when evaluating the long-term effects of these devastating phenomena.
Pathology of vaginal cancers in Port Harcourt, Nigeria. A 14-year study of 15 cases.
D Seleye-Fubara, S Uzoigwe, C I Akani
Nigerian Journal of Clinical Practice , 2007,
Abstract: Background: Primary malignancies of the vagina are rare as most are metastatic lesions. This study documents a 14-year experience in a tertiary institution in South Southern, Nigeria. Design and Setting: A retrospective study of clinical presentations including anatomic sites and histopathologic diagnosis of cancers of the vagina in the University of Port Harcourt Teaching Hospital (UPTH). Methodology: The tissues received for histologic diagnosis were fixed in 10% formal saline, processed and embedded in paraffin wax. Microtome sections of the tissue (3 5 microns) were taken and mounted on glass slides and stained with hematoxylin and eosin (H & E) stains. Cases in which both the slide and blocks could not be traced were excluded from the study. Results: A total of 2389 malignancies were diagnosed during the period under review of which 344 were gynaecological. Fifteen cases of vaginal cancers satisfied the criteria for the study, constituting 0.63% and 4.36% of the total and gynaecological malignancies respectively. Five cases (33.33%) occurred in children below the age of 20 years, while 10 cases (66.67%) were in adults. The peak incidence was in the group 0 9 and 60-69 years. Irregular vaginal bleeding was the commonest clinical presentation and the upper posterior vaginal wall was the commonest anatomic site. The most frequent histological type was the non-keratinizing squamous cell carcinoma while FIGO stage 111 (46.67%) cancer was the commonest stage at presentation. Conclusion: Vaginal cancers are rare in this environment but they contribute to high morbidity and mortality among women of all ages as the disease is diagnosed at an advanced stage.
Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications
L. Luiselli,G. C. Akani,N. Ebere,F. M. Angelici
Web Ecology (WE) , 2012, DOI: 10.5194/we-12-39-2012
Abstract: African manatees (Trichechus senegalensis) and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles Crocodylus suchus and dwarf crocodile Osteolaemus tetraspis) in the Niger Delta (Nigeria), testing the hypotheses that (i) manatees may avoid crocodiles in order to minimize risks of predation, and (ii) the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i) the three species differing significantly in terms of their macro-habitat type selection, and (ii) significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant.
Life-history and ecological distribution of chameleons (Reptilia, Chamaeleonidae) from the rain forests of Nigeria: conservation implications
Akani, G. C.,Ogbalu, O. K.,Luiselli, L
Animal Biodiversity and Conservation , 2001,
Abstract: Five species of chameleons were observed in the continuous forest zone of southern Nigeria: Chamaeleo gracilis gracilis Hallowell, 1842, Chamaeleo owenii Gray, 1831, Chamaeleo cristatus Stutchbury, 1837, Chamaeleo wiedersheimi Nieden, 1910, and Rhampholeon spectrum (Bucholz 1874). Many original locality records are presented for each species. One species is apparently rare and confined to montane habitats (C. wiedersheimi), another species is relatively common and its habitat is generalist (C. gracilis), and the other three species are vulnerable and limited to specific micro-habitats. Female R. spectrum had clutch sizes of two eggs each and exhibited a prolonged reproductive season with oviposition likely occurring during the late phase of the dry season. Females of both C. cristatus (clutch sizes: 11-14 eggs) and C. owenii (clutch sizes: 15-19 eggs) have a shorter reproductive season with oviposition occurring most probably at the interphase between the end of the wet season and the onset of the dry season, and female C. gracilis (clutch sizes: 14-23 eggs) appeared to exhibit two distinct oviposition periods (one at the interphase between the end of the wet season and the onset of the dry season, and one at the peak phase of the dry season). Diets of four sympatric species of chameleons consisted almost exclusively of arthropods. There were significant inter-group differences at either intra-specific level (with the females of the two best studied species, i.e. R. spectrum and C. gracilis, having a wider food niche breadth than males) or inter-specific level (with a continuum of dietary specialization from the less generalist (C. cristatus) to the more generalist (C. gracilis). However, 'thread-trailing' experiments indicated that activity patterns of Nigerian chameleons were relatively similar among species. The overall abundance of chameleons (as estimated from the number of specimens observed in the time unit of field effort) was relatively similar in three contrasted habitat types, but lizards were more abundant in the mature secondary forest. When greatly altered by massive logging activity, the overall abundance of chameleons in the mature secondary forest habitat declined only slightly, whereas the species diversity declined drastically. This was an effect of (i) the simultaneous extinction of three of the four species originally present in the forest plot, and of (ii) the rapid increase in abundance of a single species (C. gracilis) as a response to habitat alteration. The conservation implications of all these data are also discussed.
CELL FORMATION IN GROUP TECHNOLOGY: A SIMILARITY ORDER CLUSTERING APPROACH
Godfrey C. Onwubolu
South African Journal of Industrial Engineering , 2012,
Abstract: Grouping parts into families which can be produced by a cluster of machine cells is the cornerstone of cellular manufacturing, which in turn is the building block for flexible manufacturing systems. Cellular manufacturing is a group technology (GT) concept that has recently attracted the attention of manufacturing firms operating under jobshop environment to consider redesigning their manufacturing systems so as to take advantage of increased throughput, reduction in work-in-progress, set-up time, and lead times; leading to product quality and customer satisfaction. The paper presents a generalised approach for machine cell formation from a jobshop using similarity order clustering technique for preliminary cell grouping and considering machine utilisation for the design of nonintergrouping material handling using the single-pass heuristic. The work addresses the shortcomings of cellular manufacturing systems design and implementations which ignore machine utilisations, group sizes and intergroup moves.
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