27 research outputs found
Effect of seed size variation and sowing media on the germination performance of Caesalpinia bonduc (l) Roxb
Varying seed size influences the seedling vigour as germination of seeds is affected by sowing media. Towards optimum roduction of C. bonduc, the study therefore investigated seed size variation and sowing media on the germination potential of the species. The treatments consisted of 3 sowing media (river sand, top soil and decomposed sawdust) and seed size small (≤1.5cm), medium (>1.5cm to≤ 2.0cm) and large (> 2.0cm)to form 9 treatments combination, laid out in Completely Randomized Design and replicated 4 times. Germination counts were taken on daily basis till there was no visible germination. Percentage germination, mean daily germination (MDG), peak value (PV) and germination value (GV) was calculated. Data were subjected to analysis of variance. Large seed size sown in forest top soil (T8) had the highest germination percentage and GV of 98.3% and 2.46 respectively while small seed size sown in decomposed sawdust (T3) had the least germination percentage (77.5%). There was no significant difference (P>0.5) in all the germination parameters except germination percentage studied on the seed sizes of C. bonduc. Both germination value and germination percentage varied significantly (P< 0.5) on the sowing media used on seeds of C. bonduc. The study showed that large and medium seed sizes responded better than small seed sizes which could be as a result of large food and energy reserves present in the seed.
Keywords: seed size, emergence, sowing media, Caesalpinia bonduc, germinatio
Dry matter accumulation and growth analysis of Jatropha curcas L. as influenced by application of poultry manure and cow dung in Nigeria
Growth and yield of Jatropha curcas are low due to poor soil fertility and agronomic practices. An experiment was conducted at the Crop Garden of the Department of Crop Protection and Environmental Biology (CPEB) University of Ibadan on dry matter accumulation and growth analysis of Jatropha curcas as influenced by application of manure. Poultry Manure at 10, 20 and 40 t/ha and Cow Dung at 10, 20 and 40 t/ha (P5, P10, P20, P40 and C5, C10, C20, C40) with control (0 t/ha, M0) were evaluated (5 kg soil; 1 plant/pot)in a Completely Randomised Design. Dry weight and leaf area were obtained at monthly intervals to calculate: Relative Growth Rate, Net Assimilation Rate, Leaf Area Ratio and Leaf Area Duration using the formulae of Roderick (1978).The result showed that treatments P40, C40, P20 and C20 had the highest leaf dry weight (47.67g, 48.71g, 48.91g and 48.11g), while control had the least(23.30g), P40 had the highest stem dry weight (89.13g) which was not significantly higher than stem dry weight of C40 (86.56g), P20 (85.95g) and C20 (80.85 g) and control had the least stem dry weight of 51.78g.Treatment C40had the highest root weight (40.50g) and control had the least value of 25.41g.The net assimilation rate (NAR), relative growth rate (RGR), leaf area ration (LAR) and leaf area duration (LAD) showed that the RGR were higher between 6 and 8 weeks across all the levels. The NAR increased as the level of manure increased. Leaf area duration increased as the plant grew older across all levels while P5, C5 and control had the least. Leaf area ratio was 20.14(cm2/g) on control and 33.49(cm2/g) and 39.54 (cm2/g) on P40 and C40 respectively at last observation. Application of manure up to 20t/ha increased the dry matter accumulation and growth of Jatropha curcas.Keywords: Jatropha curcas, Organic manure, Biodiesel, Environmental sustainabilit
Storage potentials and influence of moisture contents on the germination of Vitellaria paradoxa C.F. Gaertn
Viability of seeds of many tropical tree crops during storage is influenced by several factors among which are moisture content. However, the maintenance of Vitellaria paradoxa seed viability in storage has always been a concern. This study therefore investigated the potentials and influence of moisture content on germination of seeds of the species. Two hundred (200) seeds were selected and weighed. Ten (10) seeds were thereafter selected and oven dried at 60°C for 17 hours until they attained constant dry weight so as to determine moisture content (MC). Another seed lot of 10 was selected and sown in perforated germination trays containing washed and sterilized river sand as treatment 1 (T1) replicated 4 times. The remaining 150 seeds were spread on a platform at ambient temperature (25 ± 2°C). At 2nd week, the moisture content was determined and 10 seed lot replicated 4 times were sown (T2). The procedure was repeated at 4th week (T3) and 6th week. Germination Percentage (GP), Germination Energy (GE), Mean Daily Germination (MDG), Peak Value (PV) and Germination value (GV) were determined. Data were subjected to analysis of variance (ANOVA) and Duncan Multiple Range Test (DMRT) was used in means separation. The highest germination percentage (95%) was recorded for T1 (MC = 23.33%), followed by T2 (MC = 20.93%) with (67.5%) while T4 ( MC = 10.87%), had the least (40%). The freshly depulped sown seeds (T1) had the highest MDG (1.85), PV (2.26), GV (3.82) and GE (52.2%) while T4 had least values of 0.42, 0.71, 0.50 and 25% for MDG, PV, GV and GE respectively. There were significant differences among the treatments at P<0.05 and T1 had the highest means (9.50± 0.13) while T4 had the least (5.21± 0.81).The progressive decrease in moisture content with increased storage period intensified the loss of viability of the seeds. It is therefore recommended that seeds of V. paradoxa should be stored at the temperature where their moisture content will be conserved and should not be stored beyond 4 weeks at ambient temperature for average germination percentage.Keywords: Viability, Vitellaria paradoxa, ambient temperature, moisture conten
VARIATION IN SOIL PHYSICO-CHEMICAL PROPERTIES IN THREE LAND USE TYPES OF OGUN RIVER WATERSHED
Conversion of watershed to other Land Use Types (LUTs) has implications on soil nutrients. Therefore, this study investigated the effects of three LUTs on soil physico-chemical properties of Ogun River watershed. The Ogun River watershed was stratified into Guinea Savannah (GS), Rainforest (RF) and Swamp Forest (SF) Ecological Zones (EZs). Three LUTs: Natural Forest (NF), Disturbed Forest (DF) and Farmland (FL) were purposively selected in GS: GSNF, GSDF, GSFL; RF: RFNF, RFDF, RFFL and SF: SFNF, SFDF, SFFL, respectively. Five out of sixteen plots laid along the transects lines were randomly selected in each of LUTs in the three ecological zones for soil sampling. In each of the selected plots, 5 soil samples were collected at the four corners and centre of the plot at two depths: 0-15 cm, 15-30 cm. Physico-chemical properties of soil samples were determined following standard procedures. Data were analysed using descriptive statistics and Analysis of variance (ANOVA) was used to test for differences in Physico-chemical variables of Ogun River soil samples using 3 x 3 x 2 factorial experiments. There were significant differences in Physico-chemical properties among land use types, Ecological zones and between soil depths of Ogun River watershed (P < 0.05). Soil Cation Exchange Capacity ranged from 2.37±0.01 (GSFL) to 8.50±0.04 (GSNF); Total Nitrogen increased from 0.88±0.01 (RFFL) to 4.79±0.05 (GSNF) while Soil Organic Matter ranged from 1.48±0.01 (GSFL) to 13.12±0.21 (GSNF). It was found that continuous changes in land vegetative cover Ogun River watershed through human activities negatively affected soil physico-chemical properties. Therefore, other anthropogenic activities that will intercept nutrient cycling in the watershed ecosystem must be discouraged
Antiretroviral Therapy‑related Problems among Human Immunodeficiency Virus‑infected Patients: A Focus on Medication Adherence and Pill Burden
Background: There are problems associated with antiretroviral therapy despite its achievement. Poor medication adherence and inability to tolerate large pill burden are major problems facing patients with chronic illnesses. These drug therapy problems are under-studied among people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) in Nigeria. We evaluated adherence and pill burden among this set of patients in a tertiary hospital in Lagos.
Methods: Data for eligible HIV‑infected adults were documented from case notes and through interviews using a well‑structured questionnaire. Important details extracted were sociodemographics, pills information, and CD4 counts. The main outcome measures were drug adherence, as assessed by the four‑item Morisky Medication Adherence Scale and pill burden, as measured by daily pill >5.
Results: Of the 296 patients, 219 (74%) were females. Median age (interquartile range) was 40 (35.0–47.7) years. Majority (262; 88.5%) were married, had at least a secondary education (142:48.0%), and CD4 count >500 cells/ml (215; 72.6%). Pill burden >5 pills/day was observed in 12.2% of the patients, while adherence was documented for 83.4% of the patients. Majority (259; 87.5%) were receiving fixed‑dose combination of antiretroviral drugs. Forgetfulness (16.5%) and being too busy to take pills (10.5%) were the most common reasons for nonadherence. Pill burden in those who were not receiving fixed‑dose combination was significantly associated with medication nonadherence. However, only pill burden was found to be an independent prognosticator of non-adherance. (Odd ratio = 0.67, confidenceinterval = 0.03–1.66, P < 0.00).
Conclusion: Medication nonadherence and pill burden were observed in more than one‑tenth of patients. These were the two major antiretroviral therapy‑related problems reported in this study.
Keywords: Adherence, antiretroviral therapy, human immunodeficiency virus, people living with human immunodeficiency virus/acquiredimmunodeficiency syndrome, pill burde
The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations
Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.
Materials and methods: Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches.
Results: The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants.
Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.
Conclusion: This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb–drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided
Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.
Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
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
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation