2,801 research outputs found

    Consumption of Coconut Oil (Cocos Nucifera ) on Sperm Parameters of Adult Albino Wistar Rats

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    This study was aimed at assessing the possible effects coconut oil could have on the sperm parameters of albino rats. Twenty adult male Wistar rats randomly divided into four (4) groups of five rats each were investigated. The control group received normal saline and experimental groups; Low Dose (LD), Moderate Dose (MD) and High Dose (HD) received coconut oil extract of 0.5ml/kg b.w, 1.1ml/kg b.w and 2.2ml/kg b.w respectively for fourteen days via orogastric tube. On day 14 of the experiment, the rats were euthanized under chloroform vapour and sacrificed and testes excised. There was an insignificant decrease (p<0.05) in mean testicular weight of the treated rats; LD (1.14±0.05), MD (1.16±0.05) and HD (1.12±0.06) groups compared to the control rats (1.20±0.04). Sperm count was increased significantly (p<0.05) in the animals administered with coconut oil; LD (39.72±0.28x106/ml), MD (46.76±1.46x106/ml), HD (68.18±0.39x106/ml) in comparison with animals in the control group (35.28±0.34x106/ml). Sperm motility increased significantly (p<0.05) in animals of the HD group (55.00±1.58%) compared to what was observed in rats found in LD (37.60±0.81%) and MD groups (45.00±0.84%). The HD group recorded (85.00±0.71%) sperm viability, a significant increase (p<0.05) compared to that of the control group (75.60±0.93%). Sperms with normal morphology were significantly increased (p<0.05) in LD (75.60±0.68%), MD (76.00±1.87%) and HD (87.20±0.86%) compared to the control group (69.00±1.22%). Coconut oil has no deleterious effect on the sperm parameters and can lead to enhanced spermatogenesis. Keywords: Cocos nucifera, sperm parameters, coconut oil DOI: 10.7176/JBAH/9-14-06 Publication date:July 31st 201

    Diagenetic smectite-to-illite transition in clay-rich sediments: A reappraisal of X-ray diffraction results using the multi-specimen method

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    International audienceSmectite illitization is a common mineralogical reaction occurring during the burial diagenesis of clay-rich sediments and shales, and has thus attracted sustained interest over the last fifty years. Prior studies have concluded that smectite illitization proceeds through a steady set of homogeneous reactions involving intermediate mixed layers of varying compositions. In these intermediate structures, illite and smectite, or, more generally, expandable layers (I and Exp layers, respectively) coexist among the same crystallites giving rise to non-periodic structures (I-Exp) characterized by specific diffraction effects. Consistent with this model, reaction progress was characterized by the simultaneous increase in the illite content in I-Exp and in their stacking order leading to the following mineralogical sequence: smectite → randomly interstratified I-Exp with high smectite contents (> 50% Exp layers) → ordered I-Exp with high illite contents (> 50% I layers) → illite. Although reaction mechanisms have been extensively debated, this structural characterization has not been challenged, possibly due to a methodological bias. In the present study, X-ray diffraction patterns typical of the diagenetic illitization of smectite are interpreted using modern approaches involving profile fitting (multi-specimen method). Novel insights into the structure of intermediate reaction products are thus obtained. In particular, original clay parageneses are described including the systematic presence of illite, kaolinite, chlorite and a mixed layer containing kaolinite and expandable layers (K-Exp). In contrast to previous descriptions, the early stages of smectite illitization are characterized by the coexistence of discrete smectite and of a randomly interstratified I-Exp with a high content of illite layers (>50% I layers). Both the smectite and the I-Exp are authigenic and form under shallow burial, that is at low temperature conditions. With increasing burial depth, the relative proportion of I-Exp increases, essentially at the expense of discrete smectite, and the composition of I-Exp becomes slightly more illitic. In the second stage of smectite illitization, two illite-containing mixed layers are observed. They result from two parallel reaction mechanisms affecting the randomly interstratified I-Exp present in the shallow section of the series. The first reaction implies the dissolution of this randomly interstratified I-Exp and leads to the crystallization of an ordered I-Exp without significant illitization, possibly because of the low K-availability. The second reaction affecting the randomly interstratified I-Exp implies the growth of trioctahedral (Mg, Al) hydroxide sheets in Exp interlayers, thus developing di-trioctahedral chlorite layers (Ch layers) in the initial I-Exp to form an I-Exp-Ch. A layer-by-layer mechanism is hypothesized for this reaction. In this scheme, Mg cations released by the dissolution-recrystallization reaction of I-Exp likely represent the source of Mg for the formation of brucite-like sheets in expandable interlayers, and thus of the I-Exp-Ch. The reported structural characterization of smectite illitization intermediate products contradicts the conventional wisdom of a homogeneous reaction through a series of pure mixed layers of variable composition. In contrast, the coexistence of different phases implies a heterogeneous reaction via a sequence of intermediate phases and requires reassessing the reaction mechanisms proposed in the literature. The compositional range (relative proportion of the different layer types) of these phases is limited and smectite illitization proceeds essentially as relative proportions of the different phases vary. In addition, reaction kinetics and stability of the different intermediate products also need to be reconsidered

    Resource use in sweet potato production in delta state, nigeria: a technical efficiency approach

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    Sweet potato is one of the major staple crops in Nigeria and most parts Africa sub-region. Its importance continues to rise due to increased urbanization. This increase definitely come with its share of challenges that need to be addressed. The study was conducted within the framework of the rural farming households who constitute the backbone of the Nigerian agricultural sector, producing about 80 per cent of the total national agricultural output. It examined resource use in sweet potato production in Delta state, Nigeria. The specific objectives are to determine the technical efficiency of sweet potato farmers, assess the factors determining the technical efficiency of potato farmers and to determine the technical efficiency distribution of sweet potato farmers. Multi-stage random sampling technique was adopted to select 120 respondents and stochastic frontier production function employed to realize the objectives. Result of analysis showed that the least technically efficient farmers have to increase their level of production given their inputs and technology to at least 68 % for them to operate at the production frontier while the most technically efficient farmers have to increase their production to at least by 4% for them to operate on the production frontier and be fully efficient with a mean technical efficiency of 0.71. The estimates of the parameters of the production function (sweet potato seeds, labour, fertilizers and agrochemical) were positive and significant at 5% and 1% levels respectively, while capital input was positive and not significant.  Factors affecting technical inefficiency of sweet potato farmers among others included: age of farmers and farm size which were negative and significant, while household size, educational qualification, type of cropping and farming experience were all positive and significant. The following recommendations were proffered: sweet potato farmers should have access to improved sweet potato varieties, modern storage technologies, markets and extension services. Adequate financial assistance and credit facilities should also be made available to the sweet potato farmers to enable them expand their crop output

    HIV-associated anemia after 96 weeks on therapy: determinants across age ranges in Uganda and Zimbabwe.

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    Given the detrimental effects of HIV-associated anemia on morbidity, we determined factors associated with anemia after 96 weeks of antiretroviral therapy (ART) across age groups. An HIV-positive cohort (n=3,580) of children age 5-14, reproductive age adults 18-49, and older adults ≥50 from two randomized trials in Uganda and Zimbabwe were evaluated from initiation of therapy through 96 weeks. We conducted logistic and multinomial regression to evaluate common and differential determinants for anemia at 96 weeks on therapy. Prior to initiation of ART, the prevalence of anemia (age 5-11 <10.5 g/dl, 12-14 <11 g/dl, adult females <11 g/dl, adult males <12 g/dl) was 43%, which decreased to 13% at week 96 (p<0.001). Older adults had a significantly higher likelihood of anemia compared to reproductive age adults (OR 2.60, 95% CI 1.44-4.70, p=0.002). Reproductive age females had a significantly higher odds of anemia compared to men at week 96 (OR 2.56, 95% CI 1.92-3.40, p<0.001), and particularly a greater odds for microcytic anemia compared to males in the same age group (p=0.001). Other common factors associated with anemia included low body mass index (BMI) and microcytosis; greater increases in CD4 count to week 96 were protective. Thus, while ART significantly reduced the prevalence of anemia at 96 weeks, 13% of the population continued to be anemic. Specific groups, such as reproductive age females and older adults, have a greater odds of anemia and may guide clinicians to pursue further evaluation and management

    Microstructural Evaluation of Aluminium Alloy A365 T6 in Machining Operation

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    The optimum cutting parameters such as cutting depth, feed rate, cutting speed and magnitude of the cutting force for A356 T6 was determined concerning the microstructural detail of the material. Novel test analyses were carried out, which include mechanical evaluation of the materials for density, glass transition temperature, tensile and compression stress, frequency analysis and optimisation as well as the functional analytic behaviour of the samples. The further analytical structure of the particle was performed, evaluating the surface luminance structure and the profile structure. The cross-sectional filter profile of the sample was extracted, and analyses of Firestone curve for the Gaussian filter checking the roughness and waviness profile of the structure on aluminium alloy A356T6 is proposed. A load cell dynamometer was used to measure different parameters with the combination of a conditioning signal system, a data acquisition system and a computer with visualised software. This allowed recording the variations of the main cutting force throughout the mechanised pieces under different cutting parameters. A carbide inserted tool with triangular geometry was used. The result shows that the lowest optimum cutting force is 71.123 N at 75 m/min cutting speed, 0.08 mm/rev feed rate and a 1.0 mm depth of cut. The maximum optimum cutting force for good surface finishing is 274.87 N which must be at a cutting speed of 40 m/min, 0.325 mm/rev feed rate and the same 1.0 mm depth of cut

    In-Vitro Assessment of Antioxidant and Antimicrobial Activities of Methanol Extracts of Six Wound Healing Medicinal Plants

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    In this study, quantitative values of antioxidant activity of crude methanolic extracts of five Wound healing medicinal plants (Amaranthus spinosus, Anogeissus leiocarpus, Spondia monbin, Corchorus olitorius, and Mallotus oppositifolia) were investigated. The investigation used DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical as a substrate and Ferric reducing antioxidant power (FRAP) assay to determine both scavenging ability and the reducing properties. Antioxidant was further analysed quantitatively for flavonoid content, total phenolic content in the crude methanolic extracts using spectrophotometric assay. The result showed that all plants exhibited scavenging ability and strong reducing activity although the ability differed markedly among the various plant samples. The highest scavenging ability (% inhibition) was exhibited by A. leiocarpus (95.86 ± 0.1) followed by C. olitorius (94.19 ± 0.06) while the lowest was from A. spinosus (40.87±2.5). The reducing power was also highest in A. leiocarpus followed by S. monbin; while A. spinosus showed the least reducing power. In quantitative analysis, again A. leiocarpus was found to have the highest phenolic content (1294.81± 3.0 mg/g) with A. spinosus recording the least phenol and flavonoid content. The crude methanol extracts were also screened for their antimicrobial activity against four common pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Citrobacter sp.) associated with wound infection by well diffusion method. All the extracts were found to inhibit the growth of both gram (+) and gram (-) bacteria organisms tested. Keywords: Radical scavenging effect, phenolic compounds, antioxidant activit

    Psychosocial Challenges and Strategies for Coping with HIV Among Adolescents in Uganda: A Qualitative Study

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    Although more than 90% of youth perinatally infected with HIV live in sub-Saharan Africa, little is known about the psychosocial factors that impact their wellbeing, or how these youth cope with these challenges. The purpose of this study was to identify the psychosocial challenges and coping strategies among perinatal HIV-infected adolescents in Uganda. In-depth interviews were conducted with a purposive sample of 38 HIV-infected adolescents aged 12?19 years at a large HIV treatment center in Kampala. Data were analyzed thematically to identify themes and domains related to stressors and specific coping strategies. Psychosocial challenges included stigma/discrimination, relationship challenges such as HIV status disclosure, and medication difficulties. Coping strategies included medication adherence, concealment or limited disclosure of HIV status, treatment optimism, social support, rationalizing, social comparison, spirituality/religiosity, avoidance, and distraction. Age and gender differences also emerged: younger participants generally lacked specific coping strategies; compared to females, male adolescents reported greater use of avoidance/distraction techniques. Findings underscore the need to address stigma within homes and schools, and to equip adolescents with the comprehensive knowledge and skills to address their varied challenges.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140199/1/apc.2014.0222.pd

    Kisspeptin regulation of genes involved in cell invasion and angiogenesis in first trimester human trophoblast cells

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    The precise regulation of extravillous trophoblast invasion of the uterine wall is a key process in successful pregnancies. Kisspeptin (KP) has been shown to inhibit cancer cell metastasis and placental trophoblast cell migration. In this study primary cultures of first trimester human trophoblast cells have been utilized in order to study the regulation of invasion and angiogenesis-related genes by KP. Trophoblast cells were isolated from first trimester placenta and their identity was confirmed by immunostaining for cytokeratin-7. Real-time quantitative RT-PCR demonstrated that primary trophoblast cells express higher levels of GPR54 (KP receptor) and KP mRNA than the trophoblast cell line HTR8Svneo. Furthermore, trophoblast cells also expressed higher GPR54 and KP protein levels. Treating primary trophoblast cells with KP induced ERK1/2 phosphorylation, while co-treating the cells with a KP antagonist almost completely blocked the activation of ERK1/2 and demonstrated that KP through its cognate GPR54 receptor can activate ERK1/2 in trophoblast cells. KP reduced the migratory capability of trophoblast cells in a scratch-migration assay. Real-time quantitative RT-PCR demonstrated that KP treatment reduced the expression of matrix metalloproteinase 1, 2, 3, 7, 9, 10, 14 and VEGF-A, and increased the expression of tissue inhibitors of metalloproteinases 1 and 3. These results suggest that KP can inhibit first trimester trophoblast cells invasion via inhibition of cell migration and down regulation of the metalloproteinase system and VEGF-A.The South African MRC and the University of Cape Town.http://www.plosone.orgam201

    A key role for the urokinase plasminogen activator (uPA) in invasive Group A streptococcal infection

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    Recruitment of the serine protease plasmin is central to the pathogenesis of many bacterial species, including Group A streptococcus (GAS), a leading cause of morbidity and mortality globally. A key process in invasive GAS disease is the ability to accumulate plasmin at the cell surface, however the role of host activators of plasminogen in this process is poorly understood. Here, we demonstrate for the first time that the urokinase-type plasminogen activator (uPA) contributes to plasmin recruitment and subsequent invasive disease initiation in vivo. In the absence of a source of host plasminogen activators, streptokinase (Ska) was required to facilitate cell surface plasmin acquisition by GAS. However, in the absence of Ska, host activators were sufficient to promote cell surface plasmin acquisition by GAS strain 5448 during incubation with plasminogen or human plasma. Furthermore, GAS were able mediate a significant increase in the activation of zymogen pro-uPA in human plasma. In order to assess the contribution of uPA to invasive GAS disease, a previously undescribed transgenic mouse model of infection was employed. Both C57/black 6J, and AlbPLG1 mice expressing the human plasminogen transgene, were significantly more susceptible to invasive GAS disease than uPA−/− mice. The observed decrease in virulence in uPA−/−mice was found to correlate directly with a decrease in bacterial dissemination and reduced cell surface plasmin accumulation by GAS. These findings have significant implications for our understanding of GAS pathogenesis, and research aimed at therapeutic targeting of plasminogen activation in invasive bacterial infections

    Effects of replacing fishmeal with black soldier fly larval meal in the diets of grower-finishing guinea fowls reared under tropical conditions

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    The study was conducted with the view to determine the impact of replacing fishmeal with black soldier fly larval meal (BSFLM) on growing guinea fowls. BSFLM replaced fishmeal (3% in the control diet) in the ratios of 0, 20, 40, 60, 80, and 100% to produce six dietary treatments, which were iso-caloric and iso-nitrogenous. Two hundred and forty-eight-week old guinea fowls with mean live weight of 273.2 ± 10.9 g were tagged, weighted, and randomly assigned to 24 (6 × 4) floor pens; each pen was treated as a replicate. Feed and water were provided ad libitum during the entire period, which lasted 10 weeks. Feed consumption differed among the treatment groups (P = 0.0072) with the 100% fishmeal diets recording the lowest. Daily gain was significantly (P = 0.009) higher for birds fed high BSFLM diets compared to the control (100% fishmeal diet). The inclusion of BSFLM in the diets elicited positive linear effect on weight gains of the guinea fowls (R2 = 0.91) with increasing concentration resulting in higher live weight gains. The feed conversion ratio (FCR) also differed between treatments (P < 0.05) but similar for the 100% fishmeal (control) and 100% BSFLM diets. Organ and haematopoitic integrity were equally assured regardless of levels of the protein sources fed to the birds. Generally, meats from birds fed 60 to 100% BSFLM and from hens were more acceptable. A study to evaluate the economics of utilising BSFLM in guinea fowl production is recommended
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