19 research outputs found

    Effects of graded levels of mimosa (Acacia mearnsii) tannin purified with organic solvents on gas, methane, and in vitro organic matter digestibility of Eragrostis curvula hay

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    The higher contribution of methane (CH4) to global anthropogenic potential is a cause of concern to livestock producers. Mimosa tannin gained recent acceptance as an additive for enteric CH4 mitigation. However, rumen fermentation and digestibility are compromised when large quantities of tannins are supplemented due to the presence of hydrolysable tannin and other non-tannin molecules in mimosa extract, which are toxic to animals. Purification could eliminate the toxins, and thus, reduce the CH4 yield without negative effects on rumen microbial activities and organic matter degradation. The Soxhlet extraction method was used to purify the tannin using organic solvents (ethyl acetate and pentanol). The unpurified, ethyl acetate purified, and pentanol purified tannins at the dosages of 10, 20, 30, and 40 g/kg DM of substrate (Eragrostis curvula hay) were evaluated for gas, CH4, and in vitro organic matter digestibility (IVOMD) in comparison with substrate alone. Gas kinetics were tested using a simple exponential model with lag. The results showed that compared with control, gas, CH4, IVOMD, CH4/gas, CH4/IVOMD, gas/IVOMD, asymptotic gas volume (v), and rate of gas production (k) decreased (p < 0.01) linearly with the increase in the inclusion levels of all tannin extracts. Also, ethyl acetate purified and pentanol purified tannin extracts reduced gas and CH4 at lower dosage (30 g/kg DM) compared to unpurified tannin extract at a higher level (40 g/kg). Pentanol purified tannin was more effective at lower dosage (20 g/kg DM) in terms of CH4/gas and CH4/IVOMD. It was concluded that the purification of mimosa tannin with ethyl acetate and pentanol reduced potential gas production and CH4 without much reduction in substrate digestibility when up to 30 g/kg DM of feed was used. Lower inclusion levels of ethyl acetate and pentanol purified extracts could give a similar result with a higher dosage of unpurified tanninThe National Research Foundation (NRF) and a UP PhD bursary/University of Pretoria.http://www.mdpi.com/journal/animalsAnimal and Wildlife Science

    Effect of non-encapsulated and encapsulated mimosa (Acacia mearnsii) tannins on growth performance, nutrient digestibility, methane and rumen fermentation of South African mutton Merino ram lambs

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    Please read abstract in the article.The National Research Foundation, South Africa and the University of Pretoria for a PhD research bursary.http://www.elsevier.com/locate/anifeedscihj2023Animal and Wildlife Science

    Characterization, density and in vitro controlled release properties of mimosa (Acacia mearnsii) tannin encapsulated in palm and sunflower oils

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    Tannin has gained wider acceptance as a dietary supplement in contemporary animal nutrition investigations because of its potential to reduce enteric methane emission. However, a major drawback to dietary tannin intake is the bitter taste and instability in the gastrointestinal tract (GIT). The utilization of fats as coating materials will ensure appropriate masking of the tannin’s aversive taste and its delivery to the target site. The aims of this study were to encapsulate mimosa tannin with palm oil or sunflower oil, and to assess the microcapsules in terms of encapsulation efficiency, morphology, density, and in vitro release of tannin in media simulating the rumen (pH 5.6), abomasum (pH 2.9) and small intestine (pH 7.4). The microencapsulation of mimosa tannin in palm or sunflower oils was accomplished using a double emulsion technique. The results revealed that encapsulated mimosa tannins in palm oil (EMTP) and sunflower oil (EMTS) had high yields (59% vs. 58%) and encapsulation efficiencies (70% vs. 68%), respectively. Compared to unencapsulated mimosa tannin (UMT), the morphology showed that the encapsulated tannins were smaller in size and spherical in shape. The UMT had (p < 0.01) higher particle density (1.44 g/cm3) compared to 1.22 g/cm3 and 1.21 g/cm3 for the EMTS and EMTP, respectively. The proportion of tannins released by the UMT after 24 h in the rumen (94%), abomasum (92%) and small intestine (96%) simulated buffers, reduced (p < 0.01) to 24%, 21% and 19% for the EMTS and 18%, 20% and 16% for the EMTP in similar media and timeframe. The release kinetics for the encapsulated tannins was slow and steady, thus, best fitted by the Higuchi model while the UMT dissolved quickly, hence, only fitted to a First order model. Sequential tannin release also indicated that the EMTS and EMTP were stable across the GIT. It was concluded that the microencapsulation of mimosa tannin in palm or sunflower oils stabilized tannins release in the GIT simulated buffers with the potential to modify rumen fermentation. Further studies should be conducted on the palm and sunflower oils microcapsules’ lipid stability, fatty acid transfer rate in the GIT and antioxidant properties of the encapsulated tannins.The National Research Foundation, South Africa and the University of Pretoria.https://www.mdpi.com/journal/animalsam2022Animal and Wildlife Science

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The Eritrean Islamic movement and its political role in Eritrea: case study of the Eritrean Islamic party for justice and development / Idris Abubeker Ibrahim

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    This study gives a brief background about the spread of Islam in the Abyssinian region in general and in Eritrea in particular, as well as it explores the role and contributions of the Eritrean Muslims in the Eritrean national movement struggle up to the independence day in 1993. The study discusses and analyses the history of the Eritrean Islamic movement in depth, starting from The initial influence which commenced during the 1950s and 1960s in which some well-known Eritrean figures were influenced by the Egyptian Muslim Brotherhood’s (MB) ideology, followed by formations of cells within the Eritrean society in the first half of the 1970s. The time of the Muslim pioneers organisation in the 1980s, The establishment of the Eritrean Islamic Jihad movement which sprang from the conference of unification of the Eritrean Islamist groups in November 1988 coupled with its political and organisational developments in the Eritrean arena. Equally, the study exposes the challenges and setbacks of the organisation. One of its obvious setbacks was the internal division in 1993 which led to two factions (Muslim brotherhood and Salafi group). Since then, the Islamist factions in Eritrea continued to gain ground but also faced obstacles. This study adopted historical and analytical methods in order to recognise the multidimensional nature of the issue. The study has been divided into six chapters, including the introductory and the conclusion chapters which contain the research findings and recommendations

    The Antimethanogenic Potentials of Plant Extracts: Their Yields and Phytochemical Compositions as Affected by Extractive Solvents

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    Plant phytochemicals are an important area of study in ruminant nutrition, primarily due to their antimethanogenic potentials. Plant extract yields, their bioactive compounds and antimethanogenic properties are largely dependent on the nature of the extractive solvents. This study evaluated the yields and phytochemical constituents of four plant extracts, as affected by the aqueous-methanolic (H2O-CH3OH) extraction and their antimethanogenic properties on the in vitro methane production. The plant extracts included Aloe vera, Jatropha curcas, Moringa oleifera, and Piper betle leaves with three levels of extractions (70, 85, and 100% CH3OH). The crude plant extract yields increased with the increasing amount of water. M. oleifera crude extracts yields (g/10 g) increased from 3.24 to 3.92, A. vera, (2.35 to 3.11) J. curcas (1.77 to 2.26), and P. betle (2.42 to 3.53). However, the identified and quantified metabolites showed differing degrees of solubility unique to their plant leaves in which they exist, while some of the metabolites were unaffected by the extraction solvents. The methane mitigating potentials of these extracts were evaluated as additives on Eragrostis curvula hay at a recommended rate of 50 mg kg−1 DM. The plant extracts exhibited antimethanogenic properties to various degrees, reducing (p A. vera, J. curcas, M. oleifera and P. betle reduced methane emission by 6.37–7.55%, 8.02–11.56%, 12.26–12.97, and 5.66–7.78 respectively compared to the control treatment. However, the antimethanogenic efficacy, gas production and organic matter digestibility of the plant extracts were unaffected by the extraction solvents. Metabolites, such as aloin A, aloin B and kaempferol (in A. vera), apigenin, catechin, epicatechin, kaempferol, tryptophan, procyanidins, vitexin-7-olate and isovitexin-7-olate (in J. curcas), alkaloid, kaempferol, quercetin, rutin and neochlorogenic acid (in M. oleifera) and apigenin-7,4′-diglucoside, 3-p-coumaroylquinic acid, rutin, 2-methoxy-4-vinylphenol, dihydrocaffeic acid, and dihydrocoumaric acid (in P. betle) exhibited a methane reducing potential and hence, additional studies may be conducted to test the methane reducing properties of the individual metabolites as well as their combined forms. Plant extracts could be more promising, and hence, further study is necessary to explore other extraction methods, as well as the encapsulation of extracts for the improved delivery of core materials to the target sites and to enhance methane reducing properties. Furthermore, the use of 70% aqueous extraction on M. oleifera leaf is recommended for practical use due to the reduced cost of extractive solvents, the lower cost and availability of Moringa plants in South Africa, especially in Gauteng Province. Furthermore, 70% aqueous-methanolic extractions of A. vera, J. curcas, and P. betle are recommended for practical use in regions where they exist in abundance and are cost effective

    Portomesenteric Thrombosis Secondary to Acute Cholecystitis: A Case Report

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    Portomesenteric venous thrombosis (PMVT) is an uncommon clinical problem. Common risk factors include intra-abdominal infections, abdominal surgeries, malignancy, cirrhosis, and inherited thrombophilia. Early recognition and treatment of PMVT are important to avoid serious complications like mesenteric ischemia and infarction. Acute cholecystitis is a clinical condition encountered daily but rarely may be complicated by development of portomesenteric venous thrombosis. Only few cases have been reported of superior mesenteric vein thrombosis secondary to cholecystitis. We report a case of a forty-one-year-old male patient who developed partial portal and superior mesenteric vein thrombosis after mild acute cholecystitis for which surgery had been deferred. Patient had no other identifiable risk factors for thrombosis. Patient was successfully treated with 6 months of anticoagulation with warfarin and complete recanalization of portomesenteric veins was achieved at the end of treatment

    Colchicine use might be associated with lower mortality in COVID-19 patients: A meta-analysis

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    BACKGROUND: Colchicine was recently repurposed for the management of coronavirus disease 2019 (COVID-19). This rapid review and meta-analysis aimed to assess colchicine\u27s impact on mortality outcomes in COVID-19 patients. MATERIALS AND METHODS: We systematically searched PubMed, EMBASE, Google Scholar since their inception till 25/03/2021 for observational or controlled studies that reported mortality as an outcome. The mortality odd ratios were generated with their corresponding 95% confidence intervals utilizing the random-effects model. RESULTS: Nine studies comprising 5522 patients met our inclusion criteria. Our meta-analysis revealed significantly lower mortality in the colchicine group (OR 0.35, 95% CI 0.25-0.48, I2 0%) compared with controls. A subgroup analysis limited to hospitalized patients (OR 0.35, 95% CI 0.25-0.50, I2 0%) revealed similarly lower mortality in the colchicine group. CONCLUSIONS: This meta-analysis suggests a mortality benefit with colchicine when used in the treatment of COVID-19 patients. The majority of included studies were observational; thus, the findings of this review need to be further supported by the results of ongoing trials

    Seroprevalence of SARS-CoV-2 and Hepatitis B Virus Coinfections among Ethiopians with Acute Leukemia

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    SARS-CoV-2 and blood-borne viral coinfections are well reported. Nevertheless, little is known regarding the seroprevalence of SARS-CoV-2 and coinfection with blood-borne viruses in hematologic malignancy patients in Ethiopia. We aimed to assess the seroprevalence of SARS-CoV-2 and associated infections with hepatitis B and other viruses among adolescent and adult acute leukemia patients at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia. A cross-sectional study was conducted from July 2020 to June 2021. Blood samples were tested for the presence of anti-SARS-CoV-2, HBV, HCV, and HIV with ELISA kits and occult hepatitis B infection with a real-time polymerase chain reaction assay. Out of a total 110 cases, the SARS-CoV-2 seroprevalence was 35.5%. The prevalence showed a significant increment from July 2020 to the end of June 2021 (p = 0.015). In 22.7% and 2.7% of leukemia cases, HBV and HIV, respectively, were detected. No HCV was identified. The rate of SARS-CoV-2 coinfection with HBV and HIV was 28% (11/39) and 2.6% (1/39), respectively; however, there was no statistically significant association between SARS-CoV-2 seropositivity with HBV and HIV (p > 0.05). There is a need for viral screening in leukemia cases to monitor infections and inform management
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