Pine forest investigation using high resolution P-band Pol-InSAR data

A Pol-InSAR dataset acquired at P-band over a maritime pine forest (Nezer forest of Landes, France) has been investigated and compared with tree structural ground measurements in order to identify scatterers associated with elementary scattering mechanisms in the canopy layer. Since this managed forest is constituted by different height stands, it allows to investigate mechanism change in the vertical direction during the forest growth. It has been observed that VV channel was the most elevated, which can be accounted for a maximum attenuation in the vertical direction and partially for the presence of sub-vertical branches in the top canopy layer, and that this channel was the most sensitive to the tree density in reason of an important ground reflectivity. The most pure double-bounce scattering mechanism component is received in HH-VV channel where the corresponding phase center reaches the ground level for large Diameter at Breast Height. It is also supposed that HH channel, which receives double bounce backscatter, was affected by the sub-horizontal primary branch development, which induces an elevation of the phase center over oldest trees while tree density diminution enhances backscatter from the ground level. Finally, the crosspolar channel appeared the less perturbed by the tree density than VV channel since it receives predominantly the canopy contribution.     

New Insights into the Mammalian Egg Zona Pellucida

Mammalian oocytes are surrounded by an extracellular coat called the zona pellucida (ZP), which, from an evolutionary point of view, is the most ancient of the coats that envelope vertebrate oocytes and conceptuses. This matrix separates the oocyte from cumulus cells and is responsible for species-specific recognition between gametes, preventing polyspermy and protecting the preimplantation embryo. The ZP is a dynamic structure that shows different properties before and after fertilization. Until very recently, mammalian ZP was believed to be composed of only three glycoproteins, ZP1, ZP2 and ZP3, as first described in mouse. However, studies have revealed that this composition is not necessarily applicable to other mammals. Such differences can be explained by an analysis of the molecular evolution of the ZP gene family, during which ZP genes have suffered pseudogenization and duplication events that have resulted in differing models of ZP protein composition. The many discoveries made in recent years related to ZP composition and evolution suggest that a compilation would be useful. Moreover, this review analyses ZP biosynthesis, the role of each ZP protein in different mammalian species and how these proteins may interact among themselves and with other proteins present in the oviductal lumen.     

A New Role for Plastid Thioredoxins in Seed Physiology in Relation to Hormone Regulation

In Arabidopsis seeds, ROS have been shown to be enabling actors of cellular signaling pathways promoting germination, but their accumulation under stress conditions or during aging leads to a decrease in the ability to germinate. Previous biochemical work revealed that a specific class of plastid thioredoxins (Trxs), the y-type Trxs, can fulfill antioxidant functions. Among the ten plastidial Trx isoforms identified in Arabidopsis, Trx y1 mRNA is the most abundant in dry seeds. We hypothesized that Trx y1 and Trx y2 would play an important role in seed physiology as antioxidants. Using reverse genetics, we found important changes in the corresponding Arabidopsis mutant seeds. They display remarkable traits such as increased longevity and higher and faster germination in conditions of reduced water availability or oxidative stress. These phenotypes suggest that Trxs y do not play an antioxidant role in seeds, as further evidenced by no changes in global ROS contents and protein redox status found in the corresponding mutant seeds. Instead, we provide evidence that marker genes of ABA and GAs pathways are perturbed in mutant seeds, together with their sensitivity to specific hormone inhibitors. Altogether, our results suggest that Trxs y function in Arabidopsis seeds is not linked to their previously identified antioxidant roles and reveal a new role for plastid Trxs linked to hormone regulation.     

A comparative study on comb electrodes devices made of MWPECVD diamond films grown on p-doped and intrinsic silicon substrate

Diamond is considered as a very promising material for the development of devices for radiation detection. Unlike other conventional photoconductive detectors diamond-based devices should provide high discrimination between UV and visible radiation. In this work we present the electro-optical properties of devices based on randomly oriented diamond films, synthesized in a microwave plasma enhanced chemical vapor deposition reactor. A comparative study on devices with coplanar interdigitated Cr/Au electrodes (with different interelectrode pitches) made of films grown simultaneously on intrinsic and p-doped silicon (100) substrates has been performed. The chemical-structural, morphological, electrical and optical properties of ROD films have been studied. In particular, the optical response has been measured in air using a Xe flash lamp coupled with an optical quartz fiber and a properly tailored front-end electronics based on a charge sensitive amplifier. Experimental results gave indications on how the device performances are dependent on the two types of employed substrates.     

Influence of Genetic Variations on Levels of Inflammatory Markers of Healthy Subjects at Baseline and One Week after Clopidogrel Therapy; Results of a Preliminary Study

We aimed to assess the association between the most common polymorphisms of cytochrome P450 (CYP) epoxygenases on the plasma levels of inflammatory markers in a population of healthy subjects. We also sought to determine whether CYP2C19*2 polymorphism is associated with the anti-inflammatory response to clopidogrel. In a population of 49 healthy young males, the baseline plasma levels of inflammatory markers including C-reactive protein, haptoglobin, orosomucoid acid, CD-40 were compared in carriers vs. non-carriers of the most frequent CYP epoxygenase polymorphisms: CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C8*2 and CYP2J2*7. Also, the variation of inflammatory markers from baseline to 7 days after administration of 75 mg per day of clopidogrel were compared in carriers vs. non-carriers of CYP2C19* allele and also in responders vs. hypo-responders to clopidogrel, determined by platelet reactivity tests. There was no significant association between epoxygenase polymorphisms and the baseline levels of inflammatory markers. Likewise, CYP2C19* allele was not associated with anti-inflammatory response to clopidogrel. Our findings did not support the notion that the genetic variations of CYP epoxygenases are associated with the level of inflammatory markers. Moreover, our results did not support the hypothesis that CYP2C19*2 polymorphism is associated with the variability in response to the anti-inflammatory properties of clopidogrel.     

Cavitation in unfilled and nano‐CACO3 filled HDPE subjected to tensile test: Revelation,localization, and quantification

This paper is focused on the quantitative characterization of cavitation developing in unfilled and nano‐CaCO₃ filled high density polyethylene (HDPE) subjected to tensile test. In particular, a methodology to reveal the voids, take into account their localization, and evaluate their characteristics (density and shape), is presented. For this, post‐mortem investigations coupling a cryosectioning method and a pressure‐controlled scanning electron microscope (PC‐SEM) were conducted. In the two materials, whatever the active cavitation mechanism (crazing in neat HDPE or debonding in CaCO₃/HDPE system), it was shown that the cavity density and the cavity height/width ratio (shape factor) increase with the deformation state. These two parameters are also influenced by the macroscopic stress triaxiality generated by the necking process. Indeed, when the intensity of the triaxiality is high, the cavity density and the cavity shape factor significantly increase from the skin to the core of the specimen. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Structural Diversity of PDZ–Lipid Interactions

PDZ domains are globular protein modules that are over‐and‐above appreciated for their interaction with short peptide motifs found in the cytosolic tail of membrane receptors, channels, and adhesion molecules. These domains predominate in scaffold molecules that control the assembly and the location of large signaling complexes. Studies have now emerged showing that PDZ domains can also interact with membrane lipids, and in particular with phosphoinositides. Phosphoinositides control various aspects of cell signaling, vesicular trafficking, and cytoskeleton remodeling. When investigated, lipid binding appears to be extremely relevant for PDZ protein functionality. Studies point to more than one mechanism for PDZ domains to associate with lipids. Few studies have been focused on the structural basis of PDZ–phosphoinositide interactions, and the biological consequences of such interactions. Using the current knowledge on syntenin‐1, syntenin‐2, PTP‐Bas, PAR‐3 and PICK1, we recapitulate our understanding of the structural and biochemical aspects of PDZ–lipid interactions and the consequences for peptide interactions.     

Autosomal Dominant Gyrate Atrophy-Like Choroidal Dystrophy Revisited: 45 Years Follow-Up and Association with a Novel C1QTNF5 Missense Variant

We present a long-term follow-up in autosomal dominant gyrate atrophy-like choroidal dystrophy (adGALCD) and propose a possible genotype/phenotype correlation. Ophthalmic examination of six patients from two families revealed confluent areas of choroidal atrophy resembling gyrate atrophy, starting in the second decade of life. Progression continued centrally, reaching the fovea at about 60 years of age. Subretinal deposits, retinal pigmentation or choroidal neovascularization as seen in late-onset retinal degeneration (LORD) were not observed. Whole genome sequencing revealed a novel missense variant in the C1QTNF5 gene (p.(Q180E)) which was found in heterozygous state in all affected subjects. Haplotype analysis showed that this variant found in both families is identical by descent. Three-dimensional modeling of the possible supramolecular assemblies of C1QTNF5 revealed that the p.(Q180E) variant led to the destabilization of protein tertiary and quaternary structures, affecting both the stability of the single protomer and the entire globular head, thus exerting detrimental effects on the formation of C1QTNF5 trimeric globular domains and their interaction. In conclusion, we propose that the p.(Q180E) variant causes a specific phenotype, adGALCD, that differs in multiple clinical aspects from LORD. Disruption of optimal cell-adhesion mechanisms is expected when analyzing the effects of the point mutation at the protein level.