270 research outputs found
Interactions of viruses in Cowpea: effects on growth and yield parameters
The study was carried out to investigate the effects of inoculating three cowpea cultivars: "OLO II", "OLOYIN" and IT86D-719 with three unrelated viruses: Cowpea aphid-borne mosaic virus (CABMV), genus Potyvirus, Cowpea mottle virus (CMeV), genus Carmovirus and Southern bean mosaic virus (SBMV), genus Sobemovirus singly and in mixture on growth and yield of cultivars at 10 and 30 days after planting (DAP). Generally, the growth and yield of the buffer inoculated control plants were significantly higher than those of the virus inoculated plants. Inoculation of plants at an early age of 10 DAP resulted in more severe effect than inoculations at a later stage of 30 DAP. The average values of plant height and number of leaves produced by plants inoculated 30 DAP were higher than those produced by plants inoculated 10 DAP. Most of the plants inoculated 10 DAP died and did not produce seeds. However, " OLOYIN" cultivar was most tolerant and produced reasonable yields when infected 30 DAP. The effect of single viruses on growth and yield of cultivars showed that CABMV caused more severe effects in IT86D-719, SBMV had the greatest effect on "OLO II" while CMeV induced the greatest effect on "OLOYIN". Yield was greatly reduced in double infections involving CABMV in combination with either CMeV or SBMV in "OLOYIN" and "OLO II", however, there was complete loss in yield of IT86D-719. Triple infection led to complete yield loss in all the three cultivars
Cowpea viruses: Quantitative and qualitative effects of single and mixed viral infections
Multiple viral infections have been reported on cultivated commercial cowpeas (Vigna unguiculata) in Nigeria. In this study, the effect of inoculating two commercial cultivars (cvs) (“Oloyin” and “Olo II’)and two lines from IITA (Ife Brown and TVu-76) with buffer, Cowpea aphid-borne mosaic (CABMV), Cowpea mottle (CMeV) and Southern bean mosaic (SBMV) viruses individually as well as in mixtures(CABMV+ CMeV, CABMV+ SBMV, CMeV+SBMV, and CABMV+ CMeV+SBMV) at 10 and 28 days after planting (DAP) on the growth, yield and nutritive content of seeds from infected plants were evaluated.The age of the plants at time of infection and the different viral treatments significantly affected the different parameters assessed. The average height of plants inoculated 10 DAP were significantlyshorter than those of plants inoculated 28 DAP. Inoculating with single, double and triple viruses (10 DAP) resulted in 19-34%, 31-46% and 42-53% reductions in plant height, respectively. Viral infectionsalso resulted in significant reductions in the number of pods and seeds produced. Plants inoculated with the three viruses 10 DAP produced the least number of pods and seed. Viral treatments resulted inthe production of seeds with a lower protein content of 24.8-28.9% compared with the 28.5-30.4% protein in seeds from the control plants. Plants inoculated 10 DAP with the triple viruses produced theseeds with the least protein content (24.8-27.1%). The carbohydrate, fat and moisture contents of seeds from virus infected plants were however slightly higher than those of the control plants while the ashcontents were lower. Generally, the commercial cowpea cvs were more severely affected by the viral treatments. These results indicate that infection at an early age and by multiple viruses can havedevastating effects on the growth, yield and the nutritional quality of cowpea
Immunological and molecular diagnostic methods for detection of viruses infecting cowpea (Vigna unquiculata)
Cowpea viruses are difficult to identify using morphological criteria which can be time consuming, challenging, and require extensive knowledge in taxonomy. In order to improve the quality and quantityof the germplasms and to significantly reduce the infection and transmission of virus to different cultivars of cowpea, proper diagnosis and control is essential. The immuno-diagnostic and moleculardiagnostic methods have shown great potential as far as specificity and sensitivity are concerned and can generate accurate results rapidly. The aim of this overview is to discuss the various immunodiagnostic and molecular diagnostic methods such as enzymes linked immunosorbent assay (ELISA), immunosorbent electron microscopy (ISEM), polymerase chain reaction (PCR), nucleic acidhybridization, dot immunoblotting assay (DTBIA) found suitable for diagnosis of Cowpea aphid-borne mosaic virus (CABMV), Cucumber mosaic virus (CMV) and Cowpea mottle virus (CMeV) infectingcowpea. These techniques do not only provide information for epidemiological purposes, but also help to develop disease free stock of cowpeas. Therefore, these various techniques with symptoms andhistory are of immense value to diagnose cowpea viruses and are the cornerstone of the management of cowpea cultivars
Cr-doped La-Ni-O catalysts derived from\ua0perovskite precursors for CH4-CO2 reforming under microwave irradiation
The nickel catalysts derived from Cr-doped LaNiO perovskite-like precursors were characterized by X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed oxidation, temperature-programmed reduction, and X-ray photoelectron spectroscopy. Their catalytic performance in CO reforming of methane under microwave irradiation was investigated. It was found that the structure and morphology of the oxide composites in this research were influenced by the ratio of Ni and Cr, and the mismatch of La, Ni, and Cr may cause phase segregation. The catalytic performance of the Ni catalysts is dependent on the oxygen mobility of the perovskite oxide matrix, the content of the reduced Ni, and the content of the remaining perovskite structure. The mobile oxygen in the perovskite matrix in the catalyst may enhance the conversion of CO during the reaction
Maternal contribution to ultrasound fetal measurements at mid‑pregnancy
Background: Maternal variables are known contributors to fetal variables and can be assessed during pregnancy.Objective: To assess maternal contribution to some mid‑pregnancy fetal ultrasound measurements.Materials and Methods: A prospective study involving 87 pregnant women scanned at 18–23 weeks of pregnancy was carried out. The fetal measurements were head circumference (HC), abdominal circumference (AC), femur length (FL), and biparietal diameter (BPD) while the maternal variables were age, parity, height, weight, and BMI.Results: There were intercorrelations between some maternal and fetal variables respectively. Parity correlated significantly with all the ultrasound fetal measurements (P <.05), but the association vanished with partial correlation (P >.05). Significant correlation between parity and age remained the same with simple and partial correlations (P < 0.01). Canonical correlation analysis gave four sets of canonical variables; however, none was statistically significant. Regressing fetal parameters against parity through parent‑fetus regression procedure gave significant model fit (P < 0.05), but low r2 value suggesting that variations in parity did not explain much of the variations observed in the fetal ultrasound measurements (3.9% < r2 < 6.7%). The generated models revealed HC having the highest standardized regression coefficient (b = 5.07; P <.05) while FL had the least (b = 1.08; P <.05).Conclusion: The results suggested that parity contributed significantly to fetal ultrasound measurements at mid‑pregnancy while maternal height, weight, and BMI made no significant impact.Key words: Correlation; fetal; maternal; regression; ultrasound scan
Sero-prevalence of hepatitis C virus among blood donors in Lagos, Nigeria
The prevalence of Hepatitis C virus (HCV), one of the causative agents of viral hepatitis was investigated. One hundred and sixty-seven (167) blood samples from donors which were sero-negative to hepatitis B virus markers were screened for presence of HCV IgM antibodies using a third generationELISA kit. Out of the 167 sample tested 14 (8.4%) were positive for anti-HCV with the highest prevalence rate recorded in the age group 30-39 years. There is no statistically significant association between thesex and the rate of HCV infection (p0.05)
Chlamydial Infection, Plasma Peroxidation and Obesity in Tubal Infertility
Background: Genital tract infections and obesity are both sources of oxidative stress. Alterations in immune and antioxidant parameters may arise from this or from an indeterminate autoimmune mechanism.Objective: This study aimed to investigate the association of Chlamydial infection, obesity and oxidative response with tubal infertility in Nigerian women.Methods: It was a case-control study of 40 women with tubal infertility and 32 fertile women, respectively, recruited from the Infertility and Family Planning Clinics respectively, of the University College Hospital, Ibadan, Nigeria. Anthropometric indices were measured in each subject and endocervical swabs were taken to screen for current genital tract infection.Antioxidant, hormonal and immunologic analysis were performed on serum.Results: None of the subjects had current genital tract infections. Chlamydia trachomatis IgG positivity was significantly higher in infertile than in fertile subjects [OR 4.33; 95%CI (0.078-0.681)]. No significant variations were observed in the anthropometric indices, antioxidant parameters and hormones between infertile and the fertile women. Bodymass index correlated positively with oxidative stress in infertile subjects. Waist and hip circumferences correlated negatively with oestradiol in women with tubal infertility.Conclusion: Chlamydial infection is associated with tubal factor infertility, however, obesity seems to increase oxidative stress and reduce fertility potential in women with tubal factor infertility.Key words: Tubal infertility, obesity, oxidative stress, Chlamydi
Clinical use of HIV integrase inhibitors : a systematic review and meta-analysis
Background: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings.
Methods: MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted.
Results: 48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir.
Conclusion: In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment
Associations between employee and manager gender: impacts on gender-specific risk of acute occupational injury in metal manufacturing
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