Diversity of Color Vision: Not All Australian Marsupials Are Trichromatic

Color vision in marsupials has recently emerged as a particularly interesting case among mammals. It appears that there are both dichromats and trichromats among closely related species. In contrast to primates, marsupials seem to have evolved a different type of trichromacy that is not linked to the X-chromosome. Based on microspectrophotometry and retinal whole-mount immunohistochemistry, four trichromatic marsupial species have been described: quokka, quenda, honey possum, and fat-tailed dunnart. It has, however, been impossible to identify the photopigment of the third cone type, and genetically, all evidence so far suggests that all marsupials are dichromatic. The tammar wallaby is the only Australian marsupial to date for which there is no evidence of a third cone type. To clarify whether the wallaby is indeed a dichromat or trichromatic like other Australian marsupials, we analyzed the number of cone types in the “dichromatic” wallaby and the “trichromatic” dunnart. Employing identical immunohistochemical protocols, we confirmed that the wallaby has only two cone types, whereas 20–25% of cones remained unlabeled by S- and LM-opsin antibodies in the dunnart retina. In addition, we found no evidence to support the hypothesis that the rod photopigment (rod opsin) is expressed in cones which would have explained the absence of a third cone opsin gene. Our study is the first comprehensive and quantitative account of color vision in Australian marsupials where we now know that an unexpected diversity of different color vision systems appears to have evolved

Early Presymptomatic and Long-Term Changes of Rest Activity Cycles and Cognitive Behavior in a MPTP-Monkey Model of Parkinson's Disease

It is increasingly recognized that non-motor symptoms are a prominent feature of Parkinson's disease and in the case of cognitive deficits can precede onset of the characteristic motor symptoms. Here, we examine in 4 monkeys chronically treated with low doses of the neurotoxin MPTP the early and long-term alterations of rest-activity rhythms in relationship to the appearance of motor and cognitive symptoms.Behavioral activity recordings as well as motor and cognitive assessments were carried out continuously and in parallel before, during and for several months following MPTP-treatment (12–56 weeks). Cognitive abilities were assessed using a task that is dependent on the functional integrity of the fronto-striatal axis. Rest-activity cycles were monitored continuously using infrared movement detectors of locomotor activity. Motor impairment was evaluated using standardized scales for primates. Results show that MPTP treatment led to an immediate alteration (within one week) of rest-activity cycles and cognitive deficits. Parkinsonian motor deficits only became apparent 3 to 5 weeks after initiating chronic MPTP administration. In three of the four animals studied, clinical scores returned to control levels 5–7 weeks following cessation of MPTP treatment. In contrast, both cognitive deficits and chronobiological alterations persisted for many months. Levodopa treatment led to an improvement of cognitive performance but did not affect rest-activity rhythms in the two cases tested.Present results show that i) changes in the rest activity cycles constituted early detectable consequences of MPTP treatment and, along with cognitive alterations, characterize the presymptomatic stage; ii) following motor recovery there is a long-term persistence of non-motor symptoms that could reflect differential underlying compensatory mechanisms in these domains; iii) the progressive MPTP-monkey model of presymptomatic ongoing parkinsonism offers possibilities for in-depth studies of early non-motor symptoms including sleep alterations and cognitive deficits

Circadian oscillator proteins across the kingdoms of life : Structural aspects 06 Biological Sciences 0601 Biochemistry and Cell Biology

Circadian oscillators are networks of biochemical feedback loops that generate 24-hour rhythms and control numerous biological processes in a range of organisms. These periodic rhythms are the result of a complex interplay of interactions among clock components. These components are specific to the organism but share molecular mechanisms that are similar across kingdoms. The elucidation of clock mechanisms in different kingdoms has recently started to attain the level of structural interpretation. A full understanding of these molecular processes requires detailed knowledge, not only of the biochemical and biophysical properties of clock proteins and their interactions, but also the three-dimensional structure of clockwork components. Posttranslational modifications (such as phosphorylation) and protein-protein interactions, have become a central focus of recent research, in particular the complex interactions mediated by the phosphorylation of clock proteins and the formation of multimeric protein complexes that regulate clock genes at transcriptional and translational levels. The three-dimensional structures for the cyanobacterial clock components are well understood, and progress is underway to comprehend the mechanistic details. However, structural recognition of the eukaryotic clock has just begun. This review serves as a primer as the clock communities move towards the exciting realm of structural biology

Smart Hybrid Nano-Composite Devices for Water Treatment

International @ MATERIAUX+NBO:LDJ:SDAInternational audienceNon

Nouveaux matériaux hybrides Organique-Inorganique pour la dépollution d'effluents aqueux: Cas des HAP

National @ MATERIAUX+NBO:LDJ:SDAInternational audienceNon

Synthesis of 2-(arylamino)ethyl phosphonic acids via the aza-Michael addition on diethyl vinylphosphonate

BIOVERT:MATERIAUX+YDK:SDA:LDJA simple way of synthesising 2-(arylamino)ethyl phosphonic esters and acids via the aza-Michael addition of amines to diethyl vinylphoshonate 'on water' was developed. Various 2-(arylamino)ethyl phosphonates were initially produced through the condensation of primary and secondary amines with diethyl vinylphosphonate, focussing on those bearing one aromatic moiety, giving generally good to high yields (i.e., 75-100%). These phosphonic esters were then hydrolysed in presence of bromomethylsilane to give quantitatively the corresponding phosphonic acids. (C) 2012 Elsevier Ltd. All rights reserved

A theoretical study of standard heat of formation of systems involving in the zinc reduction of silicon tetrachloride

The gas phase zinc reduction of silicon tetrachloride produces the silicon for solar cells. While this reaction provides a new low-cost production route for silicon materials for photovoltaic cells, little is known about the chemistry of this process. Theoretical methods, based on quantum chemistry predictions, in the gas phase, are now fully capable of providing molecular thermochemistry and kinetic parameters with sufficient accuracy for modeling purposes. This kind of kinetic information is crucial for reactor design and scale-up of reaction systems. In this spirit, we have developed two test sets, one for silicon and another for zinc compounds, for evaluating the performance of various computational methods: density functional theory (B3LYP, BH and HLYP, BMK, and M05-2X), and composite methods (G3 and CBS-QB3). The new generation of DFT methods BMK and M05-2X and the composite CBS-QB3 method allow to predict the standard heat of formation, Delta H-f(0), of the silicon compounds with MAD of, respectively, 7, 13, and 15 kJ mol(-1), whereas the previous DFT methods are less reliable. At least triple zeta, for basis set, is needed in order to predict correctly the standard heat of formation. For the zinc compounds, BMK, B3LYP, and CBS-QB3 are the best performing methods for the calculation of Delta H-f(0) with MADs of 24, 25, and 28 kJ mol(-1), respectively. We recommend BMK and CBS-QB3 methods for investigating the new solar silicon process

Leptomeningeal dissemination of Pilocytic astrocytoma of Conus medullaris in a 16-year-old male

Pilocytic astrocytoma (PA) is a slow growing brain tumor that tend to occur in young patients. Although PA is often a benign tumor, dissemination to leptomeninges has been described in the literature. We describe a sixteen-year-old boy who initially presented with paraplegia and progressed to severe neurological features. An intradural intramedullary spinal cord tumor was identified in medullar MRI, and diagnosis of PCA by a surgical biopsy of the lesion was performed. Subsequently, patient developed an intracranial hypertension syndrome and Craniospinal MRI revealed an intracranial and spinal leptomeningeal dissemination. The patient was treated with courses of cytotoxic consisting of carboplatin – vincristine-based chemotherapy. He died of disease two months later. Our case emphasizes the lack of benefit of chemotherapeutic agents in PA with diffuse leptomeningeal dissemination and review existing literature

Gas-assisted preparation of lead iodide perovskite films consisting of a monolayer of single crystalline grains for high efficiency planar solar cells

The simple planar configuration of organic-inorganic hybrid perovskite solar cells produced by a solution coating process has great potential to be a low-cost and high efficiency photovoltaic technology. However planar perovskite films produced by "normal" spin coating usually show a dendritic grain morphology giving many gaps in the film, resulting in poor coverage of the substrate and thus a low power conversion efficiency. Here a facile gas-assisted solution processing technique is reported that has changed the kinetics of nucleation and crystal growth of the perovskite during the spin coating, producing very uniform perovskite thin films consisting of densely packed single crystalline grains. This microstructure is an ideal candidate for the p-i-n solar cell device. Planar perovskite solar cells constructed from these films produced a highly reproducible average power conversion efficiency of 15.7 +/- 0.7%. The highest efficiency achieved was 17.0% with a slightly lower steady-state value of 16.5% at the maximum power output of the solar cell. Crown Copyrigh