Latournerié-Cervera José RománRangel-Nambo María IsabelAlma Rosa Estrada-Ortega
7页
查看更多>>摘要：Chirostoma Jordani is an endemic species of the Mexican plateau, whose population, due to anthropogenic causes, has experienced a notable decrease from 2000 to the present, putting its permanence in its natural habitat at risk. Therefore, the objectives of this research were focused on evaluating the population dynamics of C. Jordani through its size and weight distributions and growth rate during an annual cycle and on determining if there is a relationship of these processes with water quality in the study site. Monthly samplings were carried out from August to November 2014 and from February to May 2015, in the Cuemanco canal, in Xochimilco México. A total of 435 specimens were collected, the smallest sizes and weights were recorded during the months of February and April (indicating a spawning period during this time) and the largest in November. A higher growth rate was recorded in the March-May months, compared to that of August-November (0.19±0.05 and 0.04±0.03 mm/day, respectively). Thewater quality indicators: Temperature, oxygen dissolved, pH and nitrite, were highly significant in the spatio-temporal variation of the C. Jordani habitat and influenced the abundance and growth of the population. These results lay the foundations to explain the life and performance strategies of the C. Jordani population in Xochimilco, México and are fundamental to the future management of the species in the study area and under controlled conditions.
查看更多>>摘要：The general objective of the study is to characterize the woody vegetation of 05 agroforestry parkland in the Sudano-Sahelian zone of Cameroon. A total of 40 floristic surveys of 200 20 m were carried out. A total of 33 species in 20 families and 31 genera were recorded. The dendrometric survey method enabled us to characterize the vegetation of the agroforestry parks. The dendrometric parameters and indices calculated according to the agroforestry parks vary from one park to another. Thus, density varies from 108±2.98-223±8.01 individuals/ha, recovery from 6.11±0.21-10.12±0.31%, basal area from 6.54±1.12 to 10.05±1.87 m~2/ha, biovolume from 20.09±2.22-38.54±3.76 m3/ha, total height from 2.11±0.01-5.06±0.04 m, natural regeneration rate from 2.11±0.52-7.40±1.09%. The Shannon index varies from 1.36±0.20-2±0.29 bits, Pielou index from 0.14±0.07-0.35±0.18 and Simpson index from 0.82±0.02-0.97±0.03. The species with the highest SIV and SIR are Combretum glutinosum, Combretum adenogonium, Sclerocarya birrea, Prosopis africana, Entada africana, Anacardium occidentale, Burkea africana, Maytenus senegalensis, Ficus glumosa. The Mimosaceae, Caesalpiniaceae, Combretaceae show a high representativeness in relation to their family importancevalue. The diameter structure showed a predominance of young individuals and the height structure showed a predominance of individuals of class [4-6 m]. These results can be used as a reference in monitoring the vegetation dynamics of agroforestry parkssubject to recurrent droughts and anthropogenic pressures. This study provides a better understanding of the vegetation in agroforestry parks in order to better manage these plant resources.
查看更多>>摘要：One hundred and eighty (180) stool samples collected of neonates and infants from three selected health facilities in Yola, Adamawa State Nigeria. The samples were subjected to both microscopic, biochemical test and cultural identification. Bromocresol green agar and Germ tube test was used to identify Candida species. Culture of the stool samples on SDA yielded 32 yeast cells with Candida albicans as the predominant (90.63%) organism isolated followed by Candida tropicalis (9.37%). Extraction and screening for phytoconstituents of Jatropha curcas Linn parts (stem bark, leave and sap) by hot maceration using water and methanol. Showed the presence of saponins, tannins, phenols, alkanoids, steroids, flavonoids, terpenoids and glycosides. Antifungal susceptibility testing on Mueller Hinton agar, showed yeast to be susceptible to the Methanol plant extract at 400-1000 mug/mL with highest diameters of zones of inhibition (20.00 mm for sap, 13.00 mm for stem bark and 11.00 mm for leave) than the aqueousplant extract. All the parts of Jatropha curcas Linn showed MIC range of 400-1200 mug/mL for both Candida albicans and Candida tropicalis. GC-MS study showed the presence of 11 most abundant components out of 52 compounds of the methanol leaves extract46 compounds of methanol stem bark extracts respectively all of which demonstrated antimicrobial activity. Result also showed 12 most abundant components out of 56 compounds in sap of Jatropha curcas Linn with antimicrobial activity. Further study on thetoxicity and pharmacological activity should be carried out, with a view to sourcing novel antibiotic substances for possible development of broad spectrum drugs against both bacteria and fungi.
查看更多>>摘要：Teff (Eragrostis tef (Zuccagni)) is a self-pollinated, annual, warm season cereal crop, believed to have originated in Ethiopia and have been domesticated and used throughout the world due to its excellent nutritional value as grains for human consumption and as forage for livestock. The aim of this study was to determine the concentration levels of metals in teff samples across different locations and to compare with other reported values due to different agricultural applications. The mean concentration levels of the metals in the three types of teff samples collected from the three sampling areas were determined by using MP-AES and were an efficient method. The overall mean concentrations determined (mg/kg, air dry weight) for the teff samples collected from the Bure, Debre Markos and Bahir Dar sites were in the ranges of Fe (719) > Ca (289) > Zn (86) > Mn (33) > Cu (14), Fe (728) > Ca (256) > Zn (87) > Mn (29) > Cu (13) and Fe (668) > Ca (270) > Zn (73) > Mn (36) > Cu (13), respectively. The level of Fe in the white teff was higher than that of the red and mixed teff samples collected from the Bure site and it was higher in the red teff sample collected from the Debre Markos site. The amount of Fe determined in the three types of teff samplescollected from the Bahir Dar site and the concentrations of Ca, Zn, Mn and Cu determined in the three types of teff samples were almost similar within each sampling sites. The one way ANOVA indicated the mean concentrations of the studied metals found inthe three types of teff samples within and between the sampling sites was not significant at 95% confidence level.
查看更多>>摘要：This study aimed at reviewing the literature on Coronavirus (COVID-19) implications on the livelihoods of the farmers. Using a literature review, the paper aimed at understanding how COVID-19 has impacted the livelihoods of the farmers whose survivaldepends on agriculture. Driven by the following objectives; the paper reviewed firstly, lessons to be learned from the past pandemics, secondly, how COVID-19 has affected farmers’ livelihoods and thirdly, the effects of COVID-19 impacts on communities.The paper argues that, with the enormous public health policies on avoiding the spread of the pandemic, the livelihoods of the farmers have largely been affected due to reduced productivities, challenges in accessing and utilizing the markets for a nutritious and food secure life is leading to increasing poverty levels. Poverty, creates vulnerabilities making farmers susceptible to crime, human trafficking, theft and rape as observed in most African countries in the COVID-19 period. Hence, the need to avoid seeing the world through western homogeneous lenses to context-specific in the fight against the spread of COVID-19.
查看更多>>摘要：Mangosteen tree (Garcinia mangostana L.) is a plant of the Clusiaceae family cultivated for its particular taste and for its excellent medicinal properties. However, the vegetative propagation of the plant by cuttings or grafting being difficult to achieve, seed germination remains the main means of production used. This study was therefore initiated with the aim of determining the influence of three factors namely the type of seed used as seed, the mass of the seed and the soil used as a substrate on the germination parameters and on the growth of seedlings in nursery in Cote d'Ivoire. To do this, the germination parameters of seeds that received three different pretreatments (wasteland seeds, dried seeds and cold stored seeds), seeds of differentmasses (less than 1 g and more than 2 g) as well as seeds germinated on several substrates (Petri dish, forest soil, lowland soil and construction sand) were evaluated. The results obtained showed that the germination of the mangosteen seed is significantly influenced by the three factors studied. The best time, speed and germination rate were obtained with fresh seeds and seeds of masses greater than 2 g. As for the type of substrate, the highest germination rate was obtained with the seeds germinatedin the Petri dishes (99%). Regarding the monitoring of seedlings in the nursery, those from seeds with a mass greater than 2 g evolving on lowland soil recorded the best growth performance.
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