Search results for "CCO"
showing 10 items of 4678 documents
Energy and economic assessment of desiccant cooling systems coupled with single glazed air and hybrid PV/thermal solar collectors for applications in…
2009
Abstract This paper presents a detailed analysis of the energy and economic performance of desiccant cooling systems (DEC) equipped with both single glazed standard air and hybrid photovoltaic/thermal (PV/t) collectors for applications in hot and humid climates. The use of ‘solar cogeneration’ by means of PV/t hybrid collectors enables the simultaneous production of electricity and heat, which can be directly used by desiccant air handling units, thereby making it possible to achieve very energy savings. The present work shows the results of detailed simulations conducted for a set of desiccant cooling systems operating without any heat storage. System performance was investigated through h…
A comparative study between Chinese and Finns : communication accommodation and values exchange in grandparent and grandchild communication
2017
This study explores differences and similarities between grandparent-grandchild (GP-GC) communication in China and Finland. GP-GC communication and relationship has been understudied for decades since scholars in family communication domain have been focusing on relationships among other family members. The culture of the residents of China, the origin of Confucianism, is isolated from that of other East Asian nations. In view of dramatic socioeconomic development, examining how the traditional GP-GC relationship within the family has changed is valuable. On the other hand, Finland possesses a culture with contrasting traits. Characterized by individualism, Finns are prone to focus primaril…
Binding of Tat Protein to TAR Region of Human Immunodeficiency Virus Type 1 Blocks TAR-Mediated Activation of (2′-5′)Oligoadenylate Synthetase
1990
The TAR sequence of the 5' leader of HIV-1 long terminal repeat-directed mRNA was found to be able to bind to and to activate double-stranded RNA-dependent (2'-5')A synthetase. Binding of TAR to the purified synthetase in vitro was abolished by addition of HIV-1 Tat protein, which binds to this sequence with a high affinity. Inhibition of TAR-mediated activation of (2'-5')A synthetase by Tat was prevented in the presence of the Zn2+ and Cd2+ chelators o-phenanthroline and penicillamine, which did not impair TAR-synthetase interaction. Transient expression assays of bacterial chloramphenicol acetyltransferase (CAT) gene in HeLa cells revealed that the levels of both CAT mRNA and CAT protein …
Inactivation of a plastid evolutionary conserved gene affects PSII electron transport, life span and fitness of tobacco plants
2007
Chloroplasts contain a plastoquinone-NADH-oxidoreductase (Ndh) complex involved in protection against stress and the maintenance of cyclic electron flow. Inactivation of the Ndh complex delays the development of leaf senescence symptoms. Chlorophyll a fluorescence measurements, blue native gel electrophoresis, immunodetection and other techniques were employed to study tobacco (Nicotiana tabacum) Ndh-defective mutants (DeltandhF). The DeltandhF mutants compared with wild-type plants presented: (i) higher photosystem II : photosystem I (PSII : PSI) ratios; (ii) similar or higher levels of ascorbate, carotenoids, thylakoid peroxidase and superoxide dismutase, yield (Phi(PSII)) and maximal pho…
Calcium signatures and signaling in cytosol and organelles of tobacco cells induced by plant defense elicitors
2011
Calcium signatures induced by two elicitors of plant defense reactions, namely cryptogein and oligogalacturonides, were monitored at the subcellular level, using apoaequorin-transformed Nicotiana tabacum var Xanthi cells, in which the apoaequorin calcium sensor was targeted either to cytosol, mitochondria or chloroplasts. Our study showed that both elicitors induced specific Ca2+ signatures in each compartment, with the most striking difference relying on duration. Common properties also emerged from the analysis of Ca2+ signatures: both elicitors induced a biphasic cytosolic [Ca2+] elevation together with a single mitochondrial [Ca2+] elevation concomitant with the first cytosolic [Ca2+] p…
Tobacco plants detect a decrease of environmental genotoxicity in Toulouse (France).
2003
Tobacco plants, heterozygous for two independent loci involved in the chlorophyll parenchyma differentiation, allow the genotoxic effects of the atmosphere of the industrial estate South of Toulouse to be estimated. Somatic spots of green cellular colonies on yellow-green background, were counted to calculate the cellular rates of reversion. Two experiments were carried out in 1981, and in 1997. A general decrease of genotoxic effects was observed. These observations were interpreted as being due to a general decrease of the air pollution evaluated by the development of the concentrations of three toxic gases before and after the implementation of cleanup devices. The results obtained demon…
Chemical and behavioural characterization of the rabbit mammary pheromone.
2003
Mammals owe part of their evolutionary success to the harmonious exchanges of information, energy and immunity between females and their offspring. This functional reciprocity is vital for the survival and normal development of infants, and for the inclusive fitness of parents. It is best seen in the intense exchanges taking place around the mother's offering of, and the infant's quest for, milk. All mammalian females have evolved behavioural and sensory methods of stimulating and guiding their inexperienced newborns to their mammae, whereas newborns have coevolved means to respond to them efficiently. Among these cues, maternal odours have repeatedly been shown to be involved, but the chem…
Characterization of chromatographic peaks using the linearly modified Gaussian model. Comparison with the bi-Gaussian and the Foley and Dorsey approa…
2017
To characterize column performance in liquid chromatography, several parameters must be obtained from experimental data. These parameters can be computed through the numerical integration of the net signal to calculate the moments after subtraction of the baseline. This requires the establishment of the peak integration limits. The whole process introduces significant uncertainty. For this reason, several alternative procedures have been proposed to measure the area, mean time and variance, based on the assumption that the chromatographic peak can be described with a mathematical function. This allows the calculation of the peak position and variance making use of the values of the experime…
New approaches based on modified Gaussian models for the prediction of chromatographic peaks
2012
Abstract The description of skewed chromatographic peaks has been discussed extensively and many functions have been proposed. Among these, the Polynomially Modified Gaussian (PMG) models interpret the deviations from ideality as a change in the standard deviation with time. This approach has shown a high accuracy in the fitting to tailing and fronting peaks. However, it has the drawback of the uncontrolled growth of the predicted signal outside the elution region, which departs from the experimental baseline. To solve this problem, the Parabolic-Lorentzian Modified Gaussian (PLMG) model was developed. This combines a parabola that describes the variance change in the peak region, and a Lor…
Determination of heavy metal content and lipid profiles in mussel extracts from two sites on the moroccan atlantic coast and evaluation of their biol…
2012
Mussels may concentrate pollutants, with possibly significant side effects on human health. Therefore, mussels (Mytilus galloprovincialis) from two sites of the Moroccan Atlantic coast (Jorf Lasfar [JL], an industrial site, and Oualidia [OL], a vegetable-growing area), were subjected to biochemical analyses to quantify the presence of heavy metals (Cd, Cr, and Pb) and to establish the lipid profile: fatty acid, cholesterol, oxysterol, phytosterol and phospholipid content. In addition, mussel lipid extracts known to accumulate numerous toxic components were tested on murine pancreatic β-cells (MIN6), and their biological activities were measured with various flow cytometric and biochemical m…