141 research outputs found
Malignant peripheral nerve sheath tumour: A rare tumour of the breast
Malignant peripheral nerve sheath tumour is a rare tumour of the breast and this report highlights the radiological and histological features and the difficulties in making a diagnosis. A high index of suspicion when dealing with a breast lesion that has both cystic and solid components in a background of von Recklingausen’s neurofibromatosis will make the diagnosis easie
Numerical study of water coning control with Downhole Water Sink (DWS) completions in vertical and horizontal wells
Approximately 2.5 billion dollars is spent annually to solve the problem of produced water in oil and gas wells. Downhole Water Sink (DWS) technology is one industry solution to control water coning in oil wells. DWS technology involves the segregated production of oil and water through separate completions with zonal isolation packer. However, several problems have been experienced in the application of the technology in watered-out oil wells. This study identified two factors that could aid in a better modeling of the technology in old vertical wells – inclusion of capillary transition pressures and relative permeability hysteresis. It also identified a pressure enhanced capillary transition zone enlargement around the wellbore as responsible for the concurrent production of contaminated fluid from both completions. Another widely recommended industry solution to the problem of produced water is horizontal well technology. However, field reports indicates that water breakthrough into horizontal wells could be quite dramatic and tend to erode the merit of high deliverability. This study analyzed the problem of water cresting in horizontal wells and developed a “generalized compound friction pressure loss relation” for horizontal wells and pipes. The new relation includes factors such as perforations, oil-water emulsions, and radial influx of fluid into the wellbore as well as phase inversion. It also shows the results of the application of this relation in the modeling of water cresting in horizontal wells subject to bottom water drive. These results reveal an asymmetrical distribution of water influx skewed toward the heel in line with field observations. Finally, the study presents two innovative dual-completion concepts for controlling water cresting in horizontal wells adapting the principles of the Downhole Water Sink technology. The results of the initial studies shows that oil recovery could be improved by as much as 7 percent over conventional horizontal wells
Thyroid cancers amongst goiter population in a Nigerian tertiary hospital: surgical and radiographic perspective
Background: Goiters are commonly benign, but cases of malignancy can develop. Thyroid cancer is known to be commoner in whites than in blacks and in females than in males. Bone metastasis is a common occurrence and may be the initial manifestation in a small subset. We hope to determine the incidence and the cervical radiographic patterns of thyroid cancer amongst goiter population in Nigeria. Method: Surgical, histological and radiographic findings in patients with goiter who had thyroidectomy in our hospital from 1999 to 2006 were reviewed. Those with proven cancer were analyzed for sex, age and radiographic changes using SPSS 11.0 for windows. Results Thirteen (8.2%) cases out of the 160 goiters were malignant and distant metastases were present in 1.3% at presentation. The histological sub-types of malignant goiters were follicular (5.0%), papillary (1.9%) and poorly differentiated or anaplastic thyroid carcinoma (1.3%). As much as 30% of thyroid cancers demonstrated calcification on plain neck radiograph, which were commonly scattered or diffused.Conclusions: Carcinomatous goiters occurred in 9.3% of the goiter population studied with predominance of follicular variant. Surgery remains the main stay but was inappropriate in about 1.2 % of population with goitre. Aside evidence of bony destruction, TC should be suspected in goiters with mixed (diffused or scattered) calcifications
Quinine inhibits ovulation and produces oxidative stress in the ovary of cyclic Sprague-Dawley rats
Background: Quinine has been reported to possess anti-spermatogenic activities.Objectives: This study was carried out to determine the effect of quinine on ovarian function in Sprague-Dawley rats.Methods: Twenty rats with regular 4-days oestrous cycle divided into 4 groups (N=5) were used. Group I received quinine at 30 mg/kg body weight by gavage for 28 days after which they were sacrificed. The ovaries were excised for biochemical oxidation of glutathione peroxidase (GSH), superoxide dismutase (SOD), catalase and malondialdehyde (MDA). Group II received single dose quinine at 30 mg/kg body weight at 0900 hrs on day of proestrus. Blood was obtained at 1800 hrs for hormonal assay of FSH and LH. The animals were sacrificed the next morning on estrus: oviducts were examined for ova count. Groups III and IV served as controls.Results: Quinine treated rats recorded zero number of ova compared to control. Serum concentration of LH reduced significantly in the quinine treated group compared to the control. Furthermore, quinine significantly decreased the oxidant status of GSH, SOD and catalase and significantly increased MDA levels in the ovary compared to the control group.Conclusion: Quinine completely blocks ovulation, suppresses LH surge, and produces oxidative stress in the ovary.Keywords: Quinine, ovary, LH, ovulation, oxidative stress
On the causes of the African slave trade
This paper offers an integrated analysis of the forces shaping the emergence of the African slave trade over the early modern period. We focus our attention on two questions. First, why most of the increase in the demand for slaves during this period came exclusively from western Europeans. Second, and of most relevance for present-day development outcomes, why was the overwhelming majority of slaves of African origin. Technological differences in manufacturing technology, the specificities of sugar (and other crops') production, and the cultural fragmentation of the African continent all play a role in the analysis. Supporting evidence for each of our claims is provided from a broad corpus of relevant literature
Factors associated with the knowledge, practice and perceptions of contraception in rural southern Nigeria
Background: Significant proportion of maternal deaths in Nigeria is due to complications of unsafe abortions, and these abortions are responses to unwanted pregnancies that could have been prevented by effective contraceptive programming. Despite intense programmatic efforts by the Nigerian government and various non-governmental agencies toreverse the trend, there has been little evidence to suggest a systematic improvement in these indicators. Methodology: A household random survey of 1,528 women aged between 15-49 years was undertaken at Amukpe community in Nigeria, to determine theirknowledge, practice and perceptions of contraception. Results: The results showed that 86.2% of the respondents had secondary or less level of education and 19.2% of the respondents were single parents. The level of contraceptive awareness was high (92.3%) and88% of the respondents became aware of contraception in the last 14 years. Friends/relatives (40.6%), followed by nurses (31.7%) and then doctors (17.3%) were the common sources of contraceptive awareness. The most widely known contraceptive methods were injectables,condoms, POP and OCP. The specific knowledge of emergency contraception was poor. The factors associated with low contraceptive usage were poor level of training and ineffective conveyance of relevant information to clients by health personnel, low literacy levels,extremes of reproductive age and extremes of parity. Others were fear of side effects, lack of knowledge, and lack of spousal consent.Conclusion: Contraceptive usage remain poor despite high level of awareness. Effective educational and counseling interventions are likely to improve providers’ and consumers’ knowledge and subsequent uptakeof contraceptive usage
Quinine inhibits ovulation and produces oxidative stress in the ovary of cyclic Sprague-Dawley rats
Background: Quinine has been reported to possess anti-spermatogenic
activities. Objectives: This study was carried out to determine the
effect of quinine on ovarian function in Sprague-Dawley rats. Methods:
Twenty rats with regular 4-days oestrous cycle divided into 4 groups
(N=5) were used. Group I received quinine at 30 mg/kg body weight by
gavage for 28 days after which they were sacrificed. The ovaries were
excised for biochemical oxidation of glutathione peroxidase (GSH),
superoxide dismutase (SOD), catalase and malondialdehyde (MDA). Group
II received single dose quinine at 30 mg/kg body weight at 0900 hrs on
day of proestrus. Blood was obtained at 1800 hrs for hormonal assay of
FSH and LH. The animals were sacrificed the next morning on estrus:
oviducts were examined for ova count. Groups III and IV served as
controls. Results: Quinine treated rats recorded zero number of ova
compared to control. Serum concentration of LH reduced significantly in
the quinine treated group compared to the control. Furthermore, quinine
significantly decreased the oxidant status of GSH, SOD and catalase and
significantly increased MDA levels in the ovary compared to the control
group. Conclusion: Quinine completely blocks ovulation, suppresses LH
surge, and produces oxidative stress in the ovary
Moving Forward in African Economic History: Bridging the Gap Between Methods and Sources
The field of African economic history is in resurgence. This paper reviews recent and on-going research contributions and notes strengths in their wide methodological, conceptual and topical variety. In these strengths there is also a challenge: different methodological approaches may also result in divisions, particularly on the quantitative versus qualitative axis. The African Economic History Network has recently been formed to bridge the gap between methods and sources and to facilitate intellectual exchanges among the widest possible range of scholars working on Sub-Saharan economic history. This paper outlines current research projects and calls for future research as well as suggesting promising lines of enquiry in the discipline
Reconcilability of Socio-Economic Development and Environmental Conservation in Sub-Saharan Africa
- …