61 research outputs found

    On the response of impacting compliant flex run

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    Damage caused by impacts of structures can result in catastrophic failure, including huge loss of life. A typical example involves a Flexrun which is particularly vulnerable to several impacts on the ground surface. It is, therefore, becoming increasingly important to be able to model and predict such phenomena. The impact of an impacting compliant system such as a Flexrun on the ground surface is simulated by the general purpose explicit dynamic finite element program LS-DYNA. The complicated geometry has been modeled in Solid Edge ST6 before being imported into LS PrePost/LS-DYNA for the required analysis. The response characteristics of the Flexrun show the effect of impacting velocity on strain and stress histories of the mechanism. Results reveal that within the impacting velocity of 15m/s, the effective stress and strain responses remain unchanged.Keywords: compliant mechanism, impact-contact, LS-DYNA, hyperelastic, Flex-Ru

    REPRODUCTIVE PERFORMANCE, FEED INTAKE AND EFFICIENCY OF INDIGENOUS AND CROSSBRED TURKEYS

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    This study assessed the reproductive performance of indigenous and crossbred parent stocks and the influence of sire genotype on the growth and efficiency of feed utilization by their progenies. A total of 300 poults, 150 for each genotype were generated from two crosses (Nicholas white x Indigenous and Indigenous x Indigenous turkeys). Data were collected on the reproductive performance of the parents while body weight and feed intake from day old to the 20th week of age were also collected from the progenies generated. The experiment was a complete randomized design with data generated subjected to two way analysis of variance using SAS. The result of the study showed that sire genotype had significant effect (p<0.05) on semen colour and semen volume while semen pH, motility, morphology and live dead ratio were not significantly affected. Crossbred tom had higher semen volume (0.39 ml) compared to 0.18 ml recorded in indigenous turkey. Genotype had no significant effect (p>0.05) on all female reproductive traits such as fertility, hatchability, dead in-germ, weak in-shell and dead in-shell. However, the indigenous turkey had higher fertility percentage (85%) while 80% hatchability was observed in crossbred turkey. Crossbred turkey significantly (p<0.05) had higher body weight (3330g) at 20 week of age compared to the indigenous turkey (2869g). Sexual dimorphism in favour of the male turkey was also observed throughout the period of the experiment. Although the crossbred turkey consumed more feed, the efficiency of feed utilization was better in the indigenous turkey. This findings suggested that the indigenous turkeys can be successfully improved with the introgression of exotic genetic material while crossbred turkeys can be further selected for improved productive and adaptive traits. &nbsp

    Strokes in children with sickle cell disease at the National Hospital Abuja Nigeria

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    Background: Strokes occur in sickle cell disease (SCD), and are associated with significant morbidity and mortality.Objectives: To determine the prevalence of strokes amongst childrenwith SCD, and document the major clinical features, complications, effect of treatment with chronic transfusion therapy (CTT) and outcome.Methods: A descriptive retrospective study of SCD children with strokes seen at the National Hospital Abuja, Nigeria over a 2.5 year period from January 2009 – June 2012. Data was collected by scrutinizing case files obtained from the hospital medical records unit. Information obtained included demographic data, clinical features, packed cell volume (PCV), brain imaging, long term neurologic deficits, effect of CTT, stroke recurrence and outcome.Results: There were 31 children with strokes among 596 children with SCD documented in the register, giving a prevalence of 5.2%. Twenty six (26) case notes were retrieved. There were 12 males and 14 females, M: F ratio of 0.9:1; mean age was 6.4 years (SD 3.4) range: 1 year 7 months – 14 years; mean PCV at the time of strokes was 21.1% (SD 3.9) range 14 –29%. All (100%) had Haemoglobin SS on electrophoresis. Presentationswere convulsions 18, inability to use limbs 11, weakness of limbs 10; long term neurological deficits were hemiplegia 11, cognition loss 11. Three (3) children had no deficits. Brain imaging (Computed Tomography Scan and Magnetic Resonance Imaging) done in 16 (61.5%) children showed cerebral atrophy in 10, acute cerebral infarcts in 9, chronic cerebral infarcts in 6, acute intra cranial haemorrhage in 1 and normal imagings in 4 children. Twelve (12) children (46.2%) children had recurrences of stroke ranging in number from 1 to 4, which occurred 6 months to 3 years afterthe initial stroke. There were no statistical significant differences between the children with recurrences of stroke compared to those without regarding the age, sex, weight or PCVs p > 0.05. Fifteen (15) children (57.7%) wereenrolled in CTT. Two (2) out of 7 children (28.6%) that had regular CTT had stroke recurrence; compared to 5 out of 11 children (45.4%) with no CTT (p > 0.05). Four (4) out of 6 (66.7%) children with irregular CTT and 1 of 2 children who stopped CTT had stroke recurrence.Outcome: 17 children were alive, 7 were lost to follow up, 1 died and 1 was referred to another center.Conclusion: Strokes were an important cause of morbidity in Nigerianchildren with SCD, with major long term neurologic deficits. CTT appearedbeneficial in preventing stroke recurrences. Primary prevention strategy by Trans Cranial Doppler ultrasound studies of the cerebral arteries, with the aim of promptly initiating appropriate preventive therapy for stroke is strongly advocated.Key words: Sickle cell disease, Stroke, Children, Chronic Transfusion Therap

    Temporal changes in haematocrit following artemisinin-based combination treatments of uncomplicated falciparum malaria in children

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    Semilog plots of deficit in haematocrit from 30 % versus time in children with haematocrit <30 % at presentation (Pattern 6). (DOCX 16 kb

    Association between Insulin Like Growth Factor-1 (IGF-1) gene polymorphism and carcass traits in improved Nigerian indigenous chickens

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    The insulin-like growth factor-1 (IGF1) is a key regulator of muscle development and metabolism in birds and other vertebrate. Our objective was to determine the association between IGF1 gene polymorphism and carcass traits in FUNAAB Alpha chicken. Genomic DNA was extracted from the blood of 50 normal feathered birds. At 10 weeks, the birds were slaughtered for carcass traits. Specific primers for chicken IGF1 were used for amplification of a 622 base segment. The amplified gene products were digested with Hinf1 restriction enzyme and the digested fragments were genotyped. Allele frequencies were 52% and 48% for A and B, respectively. Genotype frequencies were 27%, 50% and 23% for AA, AB and BB genotypes, respectively. All carcass traits values and the IGF1 gene polymorphism observed were subjected to analysis of variance and the mean were separated using Duncan Multiple Range Test. The results showed that the occurrence of the polymorphism did not affect all the carcass traits but AB genotypes had the highest carcass traits values than the AA and BB genotypes. The conclusion of this study demonstrated that IGF-1 gene, to some extent, could be a candidate gene that affects carcass traits in Improved Nigerian indigenous chicken.Keywords: IGF-1, PCR-RFLP, indigenous chicke

    Aflatoxin Exposure and Viral Hepatitis in the Etiology of Liver Cirrhosis in The Gambia, West Africa

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    BACKGROUND: Cirrhosis of the liver is thought to be a major cause of morbidity and mortality in sub-Saharan Africa, but few controlled studies on the etiology of cirrhosis have been conducted in this region. OBJECTIVES: We aimed to elucidate the association between environmental and infectious exposures and cirrhosis in The Gambia. METHODS: Ninety-seven individuals were diagnosed with cirrhosis using a validated ultrasound scoring system and were compared with 397 controls. Participants reported demographic and food frequency information. Blood samples were tested for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis C virus (HCV) antibody, HCV RNA, and the aflatoxin-associated 249(ser) TP53 mutation. RESULTS: HBsAg seropositivity was associated with a significant increase in risk of cirrhosis [odds ratio (OR) = 8.0; 95% confidence interval (CI), 4.4-14.7] as was the presence of HBeAg (OR = 10.3; 95% CI, 2.0-53.9) and HCV infection (OR = 3.3; 95% CI, 1.2-9.5). We present novel data that exposure to aflatoxin, as assessed both by high lifetime groundnut (peanut) intake and by the presence of the 249(ser) TP53 mutation in plasma, is associated with a significant increase in the risk for cirrhosis (OR = 2.8; 95% CI, 1.1-7.7 and OR = 3.8; 95% CI, 1.5-9.6, respectively). Additionally, aflatoxin and hepatitis B virus exposure appeared to interact synergistically to substantially increase the risk of cirrhosis, although this was not statistically significant. CONCLUSIONS: Our results suggest that the spectrum of morbidity associated with aflatoxin exposure could include cirrhosis

    Acceptability of pre-referral rectal artesunate for severe malaria in children under 5 years by health workers and caregivers in the Democratic Republic of the Congo, Nigeria and Uganda

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    BACKGROUND: For children below 6 years with suspected severe malaria attending a health care provider unable to provide parenteral malaria treatment, pre-referral rectal artesunate (RAS) is recommended by the World Health Organization to prevent death and disability. A number of African countries are in the process of rolling out quality-assured RAS for pre-referral treatment of severe malaria at community-level. The success of RAS depends, among other factors, on the acceptability of RAS in the communities where it is being rolled-out. Yet to date, there is limited literature on RAS acceptability. This study aimed to determine the acceptability of RAS by health care providers and child caregivers in communities where quality assured RAS was rolled out. This study was nested within the comprehensive multi-country observational research project Community Access to Rectal Artesunate for Malaria (CARAMAL), implemented in the Democratic Republic of the Congo (DRC), Nigeria, and Uganda between 2018 and 2020. Data from three different sources were analysed to understand RAS acceptability: interviews with health workers during three health care provider surveys (N = 341 community health workers and 467 primary health facility workers), with caregivers of children < 5 years of age during three household surveys (N = 9332 caregivers), and with caregivers of children < 5 years of age who were treated with RAS and enrolled in the CARAMAL Patient Surveillance System (N = 3645 caregivers). RESULTS: RAS acceptability was high among all interviewed stakeholders in the three countries. After the roll-out of RAS, 97-100% heath care providers in DRC, 98-100% in Nigeria and 93-100% in Uganda considered RAS as very good or good. Majority of caregivers whose children had received RAS for pre-referral management of severe malaria indicated that they would want to get the medication again, if their child had the same illness (99.8% of caregivers in DRC, 100% in Nigeria and 99.9% in Uganda). In three household surveys, 67-80% of caregivers whose children had not previously received RAS considered the medication as useful. CONCLUSION: RAS was well accepted by health workers and child caregivers in DRC, Nigeria and Uganda. Acceptability is unlikely to be an obstacle to the large-scale roll-out of RAS in the studied settings

    Sustainability of multifaceted usage of biomass: A review

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    The paper focuses on collection of information on recent multifaceted usage of biomass materials with critical examination on its sustainability. The use of biomass is becoming popular, with wide global acceptance as it is considered as green technology. The use of biomass products across industrial parallels, the material combination and production processes were elucidated in this paper. Biomass materials are seen as affordable alternative to conventional materials for domestic and industrial applications. The multifaceted use of biomass, which includes, energy generation, metallurgical applications, construction purposes, reinforcement in metal matrix composite, microelectromechanical system, biochemical and traditional medicine were discussed. This underscores the need to develop a sustainable plan to meet with its diverse usage to be beyond laboratory efforts. This paper examined whether the availability of biomass can sustain its multifaceted usage or not. It also examined the modalities to ensure sustainable use of biomass. Different policies were highlighted and discussed in line with continuous multifaceted use of biomas

    Community access to rectal artesunate for malaria (CARAMAL): a large-scale observational implementation study in the Democratic Republic of the Congo, Nigeria and Uganda

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    The key to reducing malaria deaths in highly endemic areas is prompt access to quality case management. Given that many severe cases occur at peripheral level, rectal artesunate (RAS) in the form of suppositories was developed in the 1990s, allowing for rapid initiation of life-saving antimalarial treatment before referral to a health facility with full case management capabilities. One randomized controlled trial published in 2009 showed a protective effect of RAS pre-referral treatment against overall mortality of 26%, but with significant differences according to study sites and length of referral. Two important issues remained unaddressed: (1) whether the mortality impact of RAS observed under controlled trial conditions could be replicated under real-world circumstances; and (2) clear operational guidance for the wide-scale implementation of RAS, including essential health system determinants for optimal impact. From 2018 to 2020, the Community Access to Rectal Artesunate for Malaria (CARAMAL) project was conducted as a large-scale observational implementation study in the Democratic Republic of the Congo (DRC), Nigeria, and Uganda (registered on ClinicalTrials.gov as NCT03568344). CARAMAL aimed to provide high-quality field evidence on the two issues above, in three remote settings with high malaria endemicity. A number of complementary study components were implemented. The core of the CARAMAL study was the Patient Surveillance System (PSS), which allowed tracking of cases of severe febrile illness from first contact at the periphery to a referral health facility, and then on to a Day 28 visit at the home of the patient. Community and provider cross-sectional surveys complemented the PSS. Here we describe in some detail RAS implementation, as well as the key CARAMAL study components and basic implementation experience. This manuscript does not intend to present key study results, but provides an extensive reference document for the companion papers describing the impact, referral process, post-referral treatment and costing of the RAS intervention
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