1,766 research outputs found
Evaluation of four plants compost teas against fungi responsible for Corn damping-off in Côte d’Ivoire
Corn (Zea mays L.) is one of the most important cereals in Côte d'Ivoire. However, Corn seeds and seedlings are susceptible to infection by a number of soilborne fungi which caused seeds decay before or after germination. The objective of this study is to evaluate the suppressive effect of Four plants compost teas (Chromolaena odorata, Ricinus communis, Nicotiana tabacum, Azadiracta indica) on Corn damping off. In vitro assays showed a most suppressive effect of C. odorata and R. communis compost teas on mycelial growth of pathogenic fungi. Results of in vivo trials showed significant reduction of Corn seedlings diseases incidence and high seed germination percent after treatment with C. odorata, R. communis and A. indica compost teas. No efficiency effect was noted with N. tabacum compost tea. This study demonstrated the usefulness of compost tea as an efficient biological tool for the control of fungi responsible of corn damping-off
Effects of nanoparticles on murine macrophages
Metallic nanoparticles are more and more widely used in an increasing number
of applications. Consequently, they are more and more present in the
environment, and the risk that they may represent for human health must be
evaluated. This requires to increase our knowledge of the cellular responses to
nanoparticles. In this context, macrophages appear as an attractive system.
They play a major role in eliminating foreign matter, e.g. pathogens or
infectious agents, by phagocytosis and inflammatory responses, and are thus
highly likely to react to nanoparticles. We have decided to study their
responses to nanoparticles by a combination of classical and wide-scope
approaches such as proteomics. The long term goal of this study is the better
understanding of the responses of macrophages to nanoparticles, and thus to
help to assess their possible impact on human health. We chose as a model
system bone marrow-derived macrophages and studied the effect of commonly used
nanoparticles such as TiO2 and Cu. Classical responses of macrophage were
characterized and proteomic approaches based on 2D gels of whole cell extracts
were used. Preliminary proteomic data resulting from whole cell extracts showed
different effects for TiO2-NPs and Cu-NPs. Modifications of the expression of
several proteins involved in different pathways such as, for example, signal
transduction, endosome-lysosome pathway, Krebs cycle, oxidative stress response
have been underscored. These first results validate our proteomics approach and
open a new wide field of investigation for NPs impact on macrophagesComment: Nanosafe2010: International Conference on Safe Production and Use of
Nanomaterials 16-18 November 2010, Grenoble, France, Grenoble : France (2010
[Evaluation of malaria rapid diagnostic test Optimal-IT® pLDH along the Plasmodium falciparum distribution limit in Mauritania].
Performance of the malaria Rapid Diagnostic Test (RDT) OptiMal-IT® was evaluated in Mauritania where malaria is low and dependent on a short transmission season. Slide microscopy was considered as the reference method of diagnosis. Febrile patients with suspected malaria were recruited from six health facilities, 3 urban and 3 rural, during two periods (December 2011 to February 2012, and August 2012 to March 2013). Overall, 780 patients were sampled, with RDT and thick blood film microscopy results being obtained for 759 of them. Out of 774 slides examined, of which 200 were positive, P. falciparum and P. vivax mono-infections were detected in 63.5% (127) and 29.5% (59), while P. falciparum/P. vivax coinfections were detected in 7% (14). Both species were observed in all study sites, although in significantly different proportions. The proportions of thick blood film and OptiMal-IT® RDT positive individuals was 26.3% and 30.3% respectively. Sensitivity and specificity of OptiMal-IT® RDT were 89% [95% CI, 84.7-93.3] and 91.1% [88.6-93.4]. Positives and negative predictive values were 78.1% [72.2-83.7] and 95.9% [94.1-97.5]. These diagnostic values are similar to those generally reported elsewhere, and support the use of RDTs as the main diagnostic tool for malaria in Mauritanian health facilities. In the future, choice of RDTs to be used must take account of thermostability in a hot, dry environment and their ability to detect P. falciparum and P. vivax
3-D Structural Modeling of Humic Acids through Experimental Characterization, Computer Assisted Structure Elucidation and Atomistic Simulations. 1. Chelsea Soil Humic Acid
This paper describes an integrated experimental and computational framework for developing 3-D structural models for humic acids (HAs). This approach combines experimental characterization, computer assisted structure elucidation (CASE), and atomistic simulations to generate all 3-D structural models or a representative sample of these models consistent with the analytical data and bulk thermodynamic/structural properties of HAs. To illustrate this methodology, structural data derived from elemental analysis, diffuse reflectance FT-IR spectroscopy, 1-D/2-D ^1H and ^(13)C solution NMR spectroscopy, and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI QqTOF MS) are employed as input to the CASE program SIGNATURE to generate all 3-D structural models for Chelsea soil humic acid (HA). These models are subsequently used as starting 3-D structures to carry out constant temperature-constant pressure molecular dynamics simulations to estimate their bulk densities and Hildebrand solubility parameters. Surprisingly, only a few model isomers are found to exhibit molecular compositions and bulk thermodynamic properties consistent with the experimental data. The simulated ^(13)C NMR spectrum of an equimolar mixture of these model isomers compares favorably with the measured spectrum of Chelsea soil HA
Requirements modelling and formal analysis using graph operations
The increasing complexity of enterprise systems requires a more advanced
analysis of the representation of services expected than is currently possible.
Consequently, the specification stage, which could be facilitated by formal
verification, becomes very important to the system life-cycle. This paper presents
a formal modelling approach, which may be used in order to better represent
the reality of the system and to verify the awaited or existing system’s properties,
taking into account the environmental characteristics. For that, we firstly propose
a formalization process based upon properties specification, and secondly we
use Conceptual Graphs operations to develop reasoning mechanisms of verifying
requirements statements. The graphic visualization of these reasoning enables us
to correctly capture the system specifications by making it easier to determine if
desired properties hold. It is applied to the field of Enterprise modelling
Androgen receptor phosphorylation at serine 515 by Cdk1 predicts biochemical relapse in prostate cancer patients
<br>Background:Prostate cancer cell growth is dependent upon androgen receptor (AR) activation, which is regulated by specific kinases. The aim of the current study is to establish if AR phosphorylation by Cdk1 or ERK1/2 is of prognostic significance.</br> <br>Methods: Scansite 2.0 was utilised to predict which AR sites are phosphorylated by Cdk1 and ERK1/2. Immunohistochemistry for these sites was then performed on 90 hormone-naive prostate cancer specimens. The interaction between Cdk1/ERK1/2 and AR phosphorylation was investigated in vitro using LNCaP cells.</br><br>Results:Phosphorylation of AR at serine 515 (pAR(S515)) and PSA at diagnosis were independently associated with decreased time to biochemical relapse. Cdk1 and pCdk1(161), but not ERK1/2, correlated with pAR(S515). High expression of pAR(S515) in patients with a PSA at diagnosis of ≤20 ng ml(-1) was associated with shorter time to biochemical relapse (P=0.019). This translated into a reduction in disease-specific survival (10-year survival, 38.1% vs 100%, P<0.001). In vitro studies demonstrated that treatment with Roscovitine (a Cdk inhibitor) caused a reduction in pCdk1(161) expression, pAR(S515)expression and cellular proliferation.</br> <br>Conclusion: In prostate cancer patients with PSA at diagnosis of ≤20 ng ml(-1), phosphorylation of AR at serine 515 by Cdk1 may be an independent prognostic marker.</br>
Etude du ruissellement, du drainage et de l'érosion sur deux sols ferrugineux de la région centre Haute-Volta : bilan de trois années d'observation à la station de Saria
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