Characterization of new DOPC/DHPC platform for dermal applications

Systems formed by mixtures of the phospholipids dioleoylphosphatidylcholine (DOPC) and dihexanoylphosphatidylcholine (DHPC) were characterized by use of differential scanning calorimetry, small angle X-ray scattering and two electron-microscopy techniques, freeze fracture electron microscopy and cryogenic transmission electron microscopy. These techniques allowed for the determination of the size, morphology, structural topology, self-assembly and thermotropic behavior of the nanostructures present in the mixtures. The interaction between the two phospholipids provides curvatures, irregularities and the increase of thickness and flexibility in the membrane. These effects led to the formation of different aggregates with a differential distribution of both phospholipids. The effect of these systems on the skin in vivo was evaluated by measurement of the biophysical skin parameters. Our results show that the DOPC/DHPC application induces a decrease in the permeability and in the hydration of the tissue. These effects in vivo are related to different microstructural changes promoted by these systems in the skin in vitro, published in a recent work. The fundamental biophysical analyses of DOPC/DHPC systems contribute to our understanding of the mechanisms that govern their interaction with the skin.     

Bayesian networks and information theory for audio-visual perception modeling

Thanks to their different senses, human observers acquire multiple information coming from their environment. Complex cross-modal interactions occur during this perceptual process. This article proposes a framework to analyze and model these interactions through a rigorous and systematic data-driven process. This requires considering the general relationships between the physical events or factors involved in the process, not only in quantitative terms, but also in term of the influence of one factor on another. We use tools from information theory and probabilistic reasoning to derive relationships between the random variables of interest, where the central notion is that of conditional independence. Using mutual information analysis to guide the model elicitation process, a probabilistic causal model encoded as a Bayesian network is obtained. We exemplify the method by using data collected in an audio-visual localization task for human subjects, and we show that it yields a well-motivated model with good predictive ability. The model elicitation process offers new prospects for the investigation of the cognitive mechanisms of multisensory perception.     

An evaluation of the genetic connectivity and temporal stability of the blue and red shrimp Aristeus antennatus: a case study of spawning females’ grounds in the Western Mediterranean Sea

Hydrobiologia - The blue and red shrimp Aristeus antennatus has been intensively exploited by trawling fishery in the Western Mediterranean Sea. Implementation of an adequate management plan needs...     

Presence of neuritic plaques and neurofibrillary changes in the cerebral cortex of an aged lemuride primate

Some aged Microcebus murinus brains (8 to 11-years old animals) displayed a dramatic atrophy particularly in the neocortex, hippocampus, basal ganglia, hypothalamus, brainstem and cerebellum, associated with a conspicuous increase in the size of the cerebral ventricles. These morphological changes were accompanied by certain histological profiles indicative of pathology. In the cortex, these histological changes consisted of (1) a large number of neuritic plaques formed by degenerated neurites sometimes surrounding an amyloid plaque, (2) dense bundles of argyrophilic filaments in many pyramidal neurons, and (3) amyloid deposits in and around the vascular walls. So far these preliminary studies cannot prone that this degeneration is similar to the human senile dementia of Alzheimer's type, but they may indicate that Microcebus murinus may well be a good model to study cerebral aging, providing comparisons with humans. Furthermore, the size, life span and cost of this species provide further advantages over other nonhuman primates.     

High-performance liquid chromatography with UV detection and diode-array UV confirmation of isonicotinic acid hydrazide in cattle milk

A method for the determination of isonicotinic acid hydrazide (isoniazid) in milk was developed. Milk was deproteinized with trichloroacetic acid. Isoniazid was condensed with cinnamaldehyde and assayed on a reversed-phase HPLC system, with good sensitivity and accuracy (10 μg/l) with UV detection at 330 nm. Use of solid-phase extraction with a C₁₈ cartridge allows the detection limit to be lowered to 0.1 μg/l with UV detection and confirmation of isoniazid hydrazone from the diode-array UV spectrum.     

Construction of a reference linkage map of Vitis amurensis and genetic mapping of Rpv8, a locus conferring resistance to grapevine downy mildew

Downy mildew, caused by the oomycete Plasmopara viticola, is one of the major threats to grapevine. All traditional cultivars of grapevine (Vitis vinifera) are susceptible to downy mildew, the control of which requires regular application of fungicides. In contrast, many sources of resistance to P. viticola have been described in the Vitis wild species, among which is V. amurensis Rupr. (Vitaceae), a species originating from East Asia. A genetic linkage map of V. amurensis, based on 122 simple sequence repeat and 6 resistance gene analogue markers, was established using S1 progeny. This map covers 975?cM on 19 linkage groups, which represent 82% of the physical coverage of the V. vinifera reference genetic map. To measure the general level of resistance, the sporulation of P. viticola and the necrosis produced in response to infection, five quantitative and semi-quantitative parameters were scored 6?days post-inoculation on the S1 progeny. A quantitative trait locus (QTL) analysis allowed us to identify on linkage group 14 a major QTL controlling the resistance to downy mildew found in V. amurensis, which explained up to 86.3% of the total phenotypic variance. This QTL was named ??Resistance to Plasmopara viticola 8?? (Rpv8).