Characterization of a germplasm collection of the tropical pasture legume Centrosema brasilianum in subhumid west Africa

1998 ◽  
Vol 130 (2) ◽  
pp. 139-147 ◽  
Author(s):  
M. PETERS ◽  
H. KRAMER ◽  
S. A. TARAWALI ◽  
R. SCHULTZE-KRAFT

The available world collection consisting of 257 accessions of the tropical pasture legume Centrosema brasilianum (L.) Benth. was assessed between 1993 and 1995 in northern Nigeria to complement existing knowledge on the genetic diversity of this species and to identify accessions with high agronomic potential for subhumid west Africa. The excellent nutritive value and good dry matter productivity of C. brasilianum and its outstanding ability to remain green over extended dry periods confirmed its potential as an important forage resource, especially for the dry season, and indicated its possible role in soil conservation. Two distinct groups, comprising 10 and 11 accessions, were identified for further evaluation in short fallow and pasture systems, respectively. Accessions in the first group had a fast establishment, very high yields in the establishment year and good drought tolerance but yields were low to average in subsequent years. Accessions in the second group had sustained high yields under grazing, a high competitive ability and good drought tolerance.

2018 ◽  
Vol 21 (7) ◽  
pp. 526-532 ◽  
Author(s):  
Zahra Abdi Piralghar ◽  
Mohammad Mahmoodi Hashemi ◽  
Ali Ezabadi

Aim and Objective: In this work, we synthesized and characterized a novel Brönsted acidic ionic liquid from the reaction of N, N, N’, N’-tetramethylethylenediamine with chlorosulfonic acid and explored its catalytic activity in 1, 8-dioxo-octahydroxanthenes synthesis. Materials and Methods: Dimedone, aryl aldehydes, and the ionic liquid as the catalyst were reacted under solvent-free conditions. The progressive of the reaction was monitored by a thin layer of chromatography (ethyl acetate/n-hexane = 1/5). All products were characterized as the basis of their spectra data and melting point by comparison with those reported in the literature. Results: The prepared ionic liquid was successfully applied in the synthesis of 1, 8-dioxooctahydroxanthenes in good to high yields on the reaction of aryl aldehyde and dimedone at 120oC under solvent-free conditions. Conclusion: This research demonstrates that the catalyst is impressive for 1, 8-dioxo-octahydroxanthenes synthesis under solvent-free conditions.


2014 ◽  
Vol 4 (3) ◽  
pp. 224-228
Author(s):  
Elaine Lima ◽  
Edna Santos ◽  
Robert Smith ◽  
Armando Sabaa-Srur

Author(s):  
Scholastique Aguessy ◽  
Roger Idossou ◽  
Anicet G. Dassou ◽  
Yêyinou Laura Estelle Loko ◽  
Octaviano Igor Yelome ◽  
...  

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.


2021 ◽  
Author(s):  
Zampaligre Nouhoun ◽  
Tidiane Cheick Traoré ◽  
Epiphanie T.B.P. Sawadogo ◽  
Augustine Ayantunde ◽  
K.V.S.V. Prasad ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.


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