3,037 research outputs found
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
No full textUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
Exploring and FTIR-ing yeast biodiversity towards the development of superior strains for lignocellulosic ethanol
No full textRobust yeast strains with high inhibitors tolerance remain a critical requirement for the production of lignocellulosic bioethanol. These stress factors are known to severely hinder yeast growth and fermentation performance (Jönsson et al., 2013). This study aims at the design of industrial yeast suitable for the lignocellulose-to-bioethanol route. Grape marc was selected as extreme environment to search for innately tolerant yeast because of its limited nutrients, exposure to solar radiation, weak acid and ethanol content (Favaro et al., 2013 and 2014). One hundred and twenty Saccharomyces cerevisiae strains were recently described to have inhibitors, temperature and osmotic tolerance greater than those exhibited by industrial strains and showed remarkable potential for bioethanol production.
With the aim of further investigating their industrial fitness, a Fourier Transform InfraRed Spectroscopy (FTIR)-based bioassay was employed to explore the yeast metabolomic and viability responses to inhibitors. Three different strains of S. cerevisiae (Fm17, Fm84 and DSM70049) were chosen as representative for the top, medium and low inhibitors tolerance. The yeast were exposed to acetic acid, formic acid, furfural and 5-hydroxymethyl-2-furaldehyde (HMF) and analysed by a FTIR-based assay to detect the extent of the metabolomic stress, the type of response and the induced mortality. To deeper investigate the effect of the co-presence of inhibitors on yeast metabolism, FTIR analysis was also conducted on yeast cells challenged with mixtures composed by increasing dosages of each single inhibitory compound
Direct spectroscopic (FTIR) detection of intra-specific binary contaminations in yeast cultures
No full textBiocidal and inhibitory activity screening of de novo synthesized surfactants against two eukaryotic and two prokaryotic microbial species
No full textThirty-six quaternary ammonium salts, of which 28 structurally different non-commercially available surfactants, were tested to screen their biocidal and inhibitory antimicrobial activity. Their activity was compared to commercially available amphiphiles as well as to non-amphiphilic quaternary ammonium salts. As target of these compounds four microbial species were employed of which two (Saccharomyces cerevisiae and Candida albicans) were important yeast in the food and clinical environment and the other two (Escherichia coli and Listeria innocua) represented the Gram negative and positive bacteria, respec- tively. The surfactants showed the ability to kill the microbial cells in water solution and to variably hamper their growth onto agar medium. The non-amphiphilic compounds (which represent analogues of some surfactants used in this study, since they have the same head group but no hydrophobic portion) had little effect in solution and no effect against the microbial growth on plate. Amphoteric and non- amphoteric zwitterionic surfactants showed reduced biocidal activity. The most active antimicrobial agent was N-tetradecyltropinium bromide (23S) surfactant. The presence of cells did not significantly affect the ability to form micelles, as demonstrated by comparative conductometric measurements
Influence of cell parameters in Fourier transform infrared spectroscopy analysis of whole yeast cells
No full textFTIR analysis of the metabolomic stress response induced by N-alkyltropinium bromide surfactants in the yeasts Saccharomyces cerevisiae and Candida albicans
No full textThe activity of surfactants against fungal cells has been studied less than against bacteria, although the medical and industrial importance of the former is of paramount importance. In this paper the surfactant biocidal effect was measured in the yeasts Saccharomyces cerevisiae and Candida albicans with a previously described FTIR bioassay which estimates the stress level as function of the FTIR spectra variation of the cells upon exposition to the chemicals. N-tetradecyltropinium bromide was chosen as stressing agent on the basis of previous preliminary study demonstrating its ability to kill prokaryotic and especially eukaryotic cells at concentration around or over the critical micellar concentration (c.m.c.). Here we show that this surfactant is able to inactivate S. cerevisiae cells at 0.4 mM and C. albicans cells at 0.6 mM after 1 h exposition. FTIR analysis revealed that the surfactant induced metabolomics reactions of S. cerevisiae cells in the regions of amides (W2) and fatty acids (W1). In the same way C. albicans cells showed the maximum stress response in amides (W2) and mixed (W3) regions. Variations of the hydrophobic tail of this surfactant produced a reduced level of cell stress with both the 12C and 16C variants; although these two compounds were more effective in inducing cell mortality in S. cerevisiae but not in C. albicans. In conclusion, this paper has shown that, for this surfactant, the n-alkyl chain must vary between 12C and 16C and that the hydrophilic head size is not as critical as the tail length
High-Throughput Rapid and Inexpensive Assay for Quantitative Determination of Low Cell-Density Yeast Cultures
No full textA procedure for microbial cell density determination with a high-throughput densitometric assay was developed to allow a precise quantification of both free and sessile cells, such as those of a biofilm, with a large range from low to high cell densities. Densitometry was chosen because it allows fast, rapid and cost-effective measures; it is non-disruptive; and has an easy learning curve. The method setup, and the further validation, was carried out with strains of Candida albicans, C. tropicalis and C. parapsilosis. Equations were developed at the level of the single strains, of the three species and finally a general one applicable to all three species. In the cross validation, with strains absent from the training set, the method was shown to be robust and flexible. The best results were obtained with species specific equations, although the global equation performed almost as well in terms of correlation between real and estimated density values. In all cases, a correlation around 0.98 between effective and predicted density was obtained with figures ranging from 102 to 108 cells mL−1. The entire analytical part of the procedure can be accomplished with a MS Excel macro provided free of charge
Direct spectroscopic (FTIR) detection of intra-specific binary contaminations in yeast cultures. FEMS Yeast Research.
No full textRich, Sturmian, and trapezoidal words
No full textIn this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity
Characterization Results for the Poset Based Representation of Topological Relations - I: Introduction and Models
No full text@article{DBLP:journals/informaticaSI/ForlizziN99,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - I: Introduction and Models.},
journal = {Informatica (Slovenia)},
volume = {23},
number = {2},
year = {1999},
bibsource = {DBLP, http://dblp.uni-trier.de}
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