135 research outputs found
Influence of inoculation and phosphorus regimes on symbiotic nitrogen fixation and phosphorus use efficiency of Algerian cowpea (Vigna unguiculata L. (Walp.)) landraces
ArticleTo study the genotypic variation of cowpeas on plant growth and phosphorus (P)
uptake which is a function of different P regimes in the soil rhizosphere
,
6 landraces of cowpea
commonly found in northern
Algeria (
NE4, NE10, NE11, NKT5, NKT7, NKB7
) and 4 landraces
from Sahara in southern Algeria
(NAG4, NAG5, NAT2 and ND3) were studied during 2013
–
2014 in greenhouse. They were inoculated with
Mesorhizobium sp.
(S1),
Bradyrhizobium sp.
(S2)
and co
–
inoculation
(S1
–
S2)
under three P treatments:
no P supply (P0), soluble P (PP) and
insoluble P (TCP). Only varieties commonly found in northern Algeria nodulated with soluble P
(PP) and inoculation containing
Mesorhizobium
sp
. (S1). As a result of the symbiosis, the
use of
S1 has significantly increased shoot dry weight by 22%, total P content by 20% and P use
efficiency for symbiotic nitrogen fixation by 18% compared to no inoculation (T).
The landraces
from the northern of Algeria expressed a higher growth than
those from Sahara in the south of
Algeria, especially three of them (NE4, NE10 and NE11) who showed a high performance under
all P regimes. We suggest that these three landraces may be useful for improving symbiotic
nitrogen fixation in cowpeas when growth
is limited by low
–
P soils and that they could contribute
to sustainable farming systems through reduction of farm
er’s dependence on fertilizers
Prévention du cancer du col de l’utérus : Vaccination HPV
A l’échelle mondiale le cancer du col utérin est le quatrième cancer le plus fréquent chez les femmes dans le monde, après les cancers du sein, du colorectal et du poumon
Intimement liée au papilloma virus humain (HPV) puisque l’infection par HPV est considérée comme un élément obligatoire mais non suffisant à lui seul au développement du cancer du col utérin , la grande majorité des femmes infectées par un type d’HPV ne développent pas toute ; le cancer car d’autres facteurs entrent en jeu.
C’est ce très fort lien existant entre certains papillomavirus et le cancer du col de l’utérus qui a conduit au développement de vaccins prophylactiques, destinés à éviter ce cancer en empêchant l’infection vira
Highly Convergent Straightforward Stereoselective Synthesis of (+)-C(9a)-Epiepiquinamide
The total synthesis of (+)-C(9a)-epiepiquinamide has been achieved starting from ethyl 5-bromopentanoate, (RS)-tert-butanesulfinamide, nitromethane, ethyl acrylate and acetic anhydride. The diastereoselective coupling of ethyl 4-nitrobutanoate and a chiral N-tert-butanesulfinyl imine, along with a double cyclization involving a primary amine through an intramolecular N-alkylation and lactam formation, are key steps of this synthesis.We thank the continued financial support from our Ministerio de Ciencia e InnovaciĂłn (MCINN; projects CONSOLIDER INGENIO 2010-CDS2007-00006, CTQ2011-24165), the Ministerio de EconomĂa y Competitividad (MINECO; project CTQ2014-53695-P, CTQ2014-51912-REDC, CTQ2016-81797-REDC, CTQ2017-85093-P), FEDER, the Generalitat Valenciana (PROMETEOII/2014/017) the University of Alicante, the Ministère de l'Enseignement SupĂ©rieur et de la Recherche Scientifique AlgĂ©rienne; Direction de la CoopĂ©ration et des Echanges Interuniversitaires; Programme de Formation RĂ©sidentielle Ă l'Étranger au titre de l'annĂ©e universitaire 2016/2017: Programme National Exceptionnel (PNE)
Indium-, Magnesium-, and Zinc-Mediated Debenzylation of Protected 1H-Tetrazoles: A Comparative Study
5-Substituted 1-benzyltetrazoles are easily debenzylated to give the corresponding deprotected tetrazoles using dissolved metals under protic conditions: Mg/MeOH, In/MeOH, or Zn/MeCO2H are the procedures of choice for this transformation.This work was financially supported by the Agence National pour le DĂ©veloppement de la Reserch en SantĂ© (AlgĂ©rie) and the Spanish Ministerio de Ciencia e InnovaciĂłn (CTQ2011-24155, CTQ2011-24165), the Ministerio de EconomĂa y Competitividad (CTQ2013-43446-P, CTQ2014-51912-REDC, CTQ2014-53695-P, CTQ2017-85093-P), FEDER, the Generalitat Valenciana (PROMETEO 2009/039, PROMETEOII 2014/017), and the University of Alicante. We also thank the Spanish Ministerio de Asuntos Exteriores y de CooperaciĂłn (AP/039112/11)
Intercropping Promotes the Ability of Legume and Cereal to Facilitate Phosphorus and Nitrogen Acquisition through Root- Induced Processes
Intercropping of cereal and legume can improve the use of resources for crop growth compared to cropping system. An increase in soil phosphorus (P) and nitrogen (N) acquisition by root-induced biochemical changes of intercropped species has been reported as key processes of facilitation and complementarily between both intercropping legumes and cereals. Indeed, the functional facilitation prevails over interspecific competition under nutrients limiting for crop growth. Results showed that P availability significantly increased in the rhizosphere of both species, especially in intercropping under the P-deficient soil conditions. This increase was associated with high efficiency efficiency in use of rhizobial, plant growth and resource use efficiency as indicated by higher land equivalent ratio (LER) and N nutrition index. In addition, the rhizosphere P availability and nodule biomass were positively correlated (r2 = 0.71**, and r2 = 0.62**) in the intercropped common bean grown at P-deficient soil. The increased P availability presumably improved biomass and yield in intercropping, although it mainly enhanced intercropped maize grain yield. Exploiting belowground parameters in a legume-cereal intercropping is likely necessary to maximize rhizosphere-interspecific interactions as a strategy to improve the symbiotic rhizobial efficiency and microbial activities, as a result of root-induced pH and N availability changes under low P soils
Economic assessment of the development of CO2 direct reduction technologies in long-term climate strategies of the Gulf countries
This paper proposes an assessment of long-term climate strategies for oil- and gas-producing countries—in particular, the Gulf Cooperation Council (GCC) member states—as regards the Paris Agreement goal of limiting the increase of surface air temperature to 2°C by the end of the twenty-first century. The study evaluates the possible role of carbon dioxide removal (CDR) technologies under an international emissions trading market as a way to mitigate welfare losses. To model the strategic context, one assumes that a global cumulative emissions budget will have been allocated among different coalitions of countries—the GCC being one of them—and the existence of an international emissions trading market. A meta-game model is proposed in which deployment of CDR technologies as well as supply of emission rights are strategic variables and the payoffs are obtained from simulations of a general equilibrium model. The results of the simulations indicate that oil and gas producing countries and especially the GCC countries face a significant welfare loss risk, due to “unburnable oil” if a worldwide climate regime as recommended by the Paris Agreement is put in place. The development of CDR technologies, in particular direct air capture (DAC) alleviates somewhat this risk and offers these countries a new opportunity for exploiting their gas reserves and the carbon storage capacity offered by depleted oil and gas reservoirs.This paper was made possible by NPRP grant number 10-0212-170447 from the Qatar National Research Fund (a member of Qatar Foundation). The first author acknowledges support provided by FONDECYT 1190325 and by ANILLO ACT192094, Chile. The fourth author also received support provided by the IFP School Chair on Carbon Management (CARMA). The last author also received support provided by the H2020 European Commission Project “PARIS REINFORCE” under grant agreement no. 820846
Loss of NK Stimulatory Capacity by Plasmacytoid and Monocyte-Derived DC but Not Myeloid DC in HIV-1 Infected Patients
Dendritic cells (DC) are potent inducers of natural killer (NK) cells. There are two distinct populations in blood, myeloid (mDC) and plasmacytoid (pDC) but they can also be generated In vitro from monocytes (mdDC). Although it is established that blood DC are lost in HIV-1 infection, the full impact of HIV-1 infection on DC-NK cell interactions remains elusive. We thus investigated the ability of pDC, mDC, and mdDC from viremic and anti-retroviral therapy-treated aviremic HIV-1+ patients to stimulate various NK cell functions. Stimulated pDC and mdDC from HIV-1+ patients showed reduced secretion of IFN-α and IL-12p70 respectively and their capacity to stimulate expression of CD25 and CD69, and IFN-γ secretion in NK cells was also reduced. pDC activation of NK cell degranulation in response to a tumour cell line was severely reduced in HIV-1+ patients but the ability of mDC to activate NK cells was not affected by HIV-1 infection, with the exception of HLA-DR induction. No differences were observed between viremic and aviremic patients indicating that anti-retroviral therapy had minimal effect on restoration on pDC and mdDC-mediated activation of NK cells. Results from this study provide further insight into HIV-1 mediated suppression of innate immune functions
Human NK Cell Up-regulation of CD69, HLA-DR, Interferon Îł Secretion and Cytotoxic Activity by Plasmacytoid Dendritic Cells is Regulated through Overlapping but Different Pathways
Human plasmacytoid dendritic cells secrete high levels of IFNα and are thus implicated in the activation of NK cells. Activated NK cells are characterised by the up-regulation of CD69 and MHC class II DR expression, secretion of IFN γ and enhanced cytotoxicity. We show that pDC mediate these processes by different mechanisms, some of which overlap. Human NK cells were analysed after co-culture with immature or CpG-matured blood pDC or with supernatant from these cells. Maximal CD69 expression by NK cells was mediated by supernatant from mature pDC and did not require pDC contact. Up-regulation was due in part to IFNα but also to factors in IFNα negative supernatant from immature DC. HLA-DR expression was independent of secreted molecules but required contact with immature or mature DC. Enhanced NK cytotoxicity, measured by killing of K562 targets and expression of CD107a, was mediated by multiple factors including type I IFN, supernatant from immature pDC cultures and contact with immature or mature pDC. These factors act cumulatively to enhance cytotoxcity. Thus different parameters of pDC mediated NK cell activation are regulated by distinct pathways
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