Responses of salmonids to habitat changes

Streams in western North America provide spawning and rearing habitats for several species of salmon and trout that are of substantial economic importance in the region. Timber that grows on lands through which these streams flow is also economically important, and its harvest can substantially change habitat conditions and aquatic production in salmonid streams. Undisturbed forests, the streams that flow through them, and the salmonid communities in these streams have intrinsic scientific, genetic, and cultural values in addition to their economic importance. The complex relations between salmonids and their physical environment, and the changes in these relations brought about by timber harvest, have been investigated extensively (see the bibliography by Macdonald et al. 1988). However, in spite of considerable evidence of profound changes in channel morphology and in light, temperature, and flow regimes associated with timber harvests, much uncertainty exists about the responses of salmonids to these changes

Innovative passive reinforcements for the gradual stabilization of a landslide according with the observational method

A large number of landslides occur in North-Eastern Italy during every rainy period due to the particular hydrogeological conditions of this area. Even if there are no casualties, the economic losses are often significant, and municipalities frequently do not have sufficient financial resources to repair the damage and stabilize all the unstable slopes. In this regard, the research for more economically sustainable solutions is a crucial challenge. Floating composite anchors are an innovative and low-cost technique set up for slope stabilization: it consists in the use of passive sub-horizontal reinforcements, obtained by coupling a traditional self-drilling bar with some tendons cemented inside it. This work concerns the application of this technique according to the observational method described within the Italian and European technical codes and mainly recommended for the design of geotechnical works, especially when performed in highly uncertain site conditions. The observational method prescribes designing an intervention and, at the same time, using a monitoring system in order to correct and adapt the project during realization of the works on the basis of new data acquired while on site. The case study is the landslide of Cischele, a medium landslide which occurred in 2010 after an exceptional heavy rainy period. In 2015, some floating composite anchors were installed to slow down the movement, even if, due to a limited budget, they were not enough to ensure the complete stabilization of the slope. Thanks to a monitoring system installed in the meantime, it is now possible to have a comparison between the site conditions before and after the intervention. This allows the evaluation of benefits achieved with the reinforcements and, at the same time, the assessment of additional improvements. Two stabilization scenarios are studied through an FE model: the first includes the stabilization system built in 2015, while the second evaluates a new solution proposed to further increase the slope stability

Hedgehog Signalling in Androgen Independent Prostate Cancer

Objectives: Androgen-deprivation therapy effectively shrinks hormone-naïve prostate cancer, both in the prostate and at sites of distant metastasis. However prolonged androgen deprivation generally results in relapse and androgen-independent tumour growth, which is inevitably fatal. The molecular events that enable prostate cancer cells to proliferate in reduced androgen conditions are poorly understood. Here we investigate the role of Hedgehog signalling in androgen-independent prostate cancer (AIPC). Methods: Activity of the Hedgehog signalling pathway was analysed in cultured prostate cancer cells, and circulating prostate tumour cells were isolated from blood samples of patients with AIPC. Results: AIPC cells were derived through prolonged culture in reduced androgen conditions, modelling hormone therapy in patients, and expressed increased levels of Hedgehog signalling proteins. Exposure of cultured AIPC cells to cyclopamine, which inhibits Hedgehog signalling, resulted in inhibition of cancer cell growth. The expression of the Hedgehog receptor PTCH and the highly prostate cancer-specific gene DD3PCA3 was significantly higher in circulating prostate cancer cells isolated from patients with AIPC compared with samples prepared from normal individuals. There was an association between PTCH and DD3PCA3 expression and the length of androgen-ablation therapy. Conclusions: Our data are consistent with reports implicating overactivity of Hedgehog signalling in prostate cancer and suggest that Hedgehog signalling contributes to the androgen-independent growth of prostate cancer cells. As systemic anti-Hedgehog medicines are developed, the Hedgehog pathway will become a potential new therapeutic target in advanced prostate cancer.Peer reviewedFinal Accepted Versio

Performance modeling of ultraviolet Raman lidar systems for daytime profiling of atmospheric water vapor

We describe preliminary results from a comprehensive computer model developed to guide optimization of a Raman lidar system for measuring daytime profiles of atmospheric water vapor, emphasizing an ultraviolet, solar-blind approach

The sticking probability of D2O-water on ice: Isotope effects and the influence of vibrational excitation

International audienceThe present study measures the sticking probability of heavy water (D2O) on H2O- and on D2O-ice and probes the influence of selective OD-stretch excitation on D2O sticking on these ices. Molecular beam techniques are combined with infrared laser excitation to allow for precise control of incident angle, translational energy, and vibrational state of the incident molecules. For a translational energy of 69 kJ/mol and large incident angles (θ ≥ 45°), the sticking probability of D2O on H2O-ice was found to be 1% lower than on D2O-ice. OD-stretch excitation by IR laser pumping of the incident D2O molecules produces no detectable change of the D2O sticking probability (<10−3). The results are compared with other gas/surface systems for which the effect of vibrational excitation on trapping has been probed experimentally

Effect of the Structure of Amido-polynitrogen Molecules on the Complexation of Actinides

AbstractThe complexation and solvent extraction of Eu(III) and actinides in different oxidation states (Am(III), Pu(IV), Np(V)) by bitopic molecules with a dipyridyl-phenanthroline cycle as nitrogen unit and one or two amido functions are described. The complexation has been studied in methanol-water solution with hydrophilic molecules to enhance knowledge about this new family of ligands and to identify the most interesting structural effect. Some extraction tests have been performed with lipophilic molecules of the family to check the possible utility of the new class of ligands under representative fuel reprocessing conditions. These first studies have demonstrated that the presence of a preorganized N-donors unit like dipyridyl-phenanthroline improves the ligand's affinity for actinides and its An/Ln selectivity

Quantum state-resolved gas/surface reaction dynamics probed by reflection absorption infrared spectroscopy

International audienceWe report the design and characterization of a new molecular-beam/surface-science apparatus for quantum state-resolved studies of gas/surface reaction dynamics combining optical state-specific reactant preparation in a molecular beam by rapid adiabatic passage with detection of surface-bound reaction products by reflection absorption infrared spectroscopy (RAIRS). RAIRS is a non-invasive infrared spectroscopic detection technique that enables online monitoring of the buildup of reaction products on the target surface during reactant deposition by a molecular beam. The product uptake rate obtained by calibrated RAIRS detection yields the coverage dependent state-resolved reaction probability S(θ). Furthermore, the infrared absorption spectra of the adsorbed products obtained by the RAIRS technique provide structural information, which help to identify nascent reaction products, investigate reaction pathways, and determine branching ratios for different pathways of a chemisorption reaction. Measurements of the dissociative chemisorption of methane on Pt(111) with this new apparatus are presented to illustrate the utility of RAIRS detection for highly detailed studies of chemical reactions at the gas/surface interface

Control of GABA Release at Mossy Fiber-CA3 Connections in the Developing Hippocampus

In this review some of the recent work carried out in our laboratory concerning the functional role of GABAergic signalling at immature mossy fibres (MF)-CA3 principal cell synapses has been highlighted. While in adulthood MF, the axons of dentate gyrus granule cells release onto CA3 principal cells and interneurons glutamate, early in postnatal life they release GABA, which exerts into targeted cells a depolarizing and excitatory action. We found that GABAA-mediated postsynaptic currents (MF-GPSCs) exhibited a very low probability of release, were sensitive to L-AP4, a group III metabotropic glutamate receptor agonist, and revealed short-term frequency-dependent facilitation. Moreover, MF-GPSCs were down regulated by presynaptic GABAB and kainate receptors, activated by spillover of GABA from MF terminals and by glutamate present in the extracellular medium, respectively. Activation of these receptors contributed to the low release probability and in some cases to synapses silencing. By pairing calcium transients, associated with network-driven giant depolarizing potentials or GDPs (a hallmark of developmental networks thought to represent a primordial form of synchrony between neurons), generated by the synergistic action of glutamate and GABA with MF activation increased the probability of GABA release and caused the conversion of silent synapses into conductive ones suggesting that GDPs act as coincident detector signals for enhancing synaptic efficacy. Finally, to compare the relative strength of CA3 pyramidal cell output in relation to their MF glutamatergic or GABAergic inputs in adulthood or in postnatal development, respectively, a realistic model was constructed taking into account different biophysical properties of these synapses

Lost but Not Forgotten—The Economics of Improving Patient Retention in AIDS Treatment Programs

Gregory Bisson and Jeffrey Stringer discuss the implications of a new study showing how loss to follow-up affects the effectiveness of a public sector HIV program in Côte d'Ivoire

Reduction of hydraulic losses in a piston pump

The hydraulic losses are the decrease in energy of the fluid due to vortex formation, friction between the fluid and the pipe, changing the flow of fluid. The decrease in energy of the fluid, in turn, leads to the following consequences: decrease efficiency, increase energy consumption and decrease cavitation stock pump. The main danger in a piston pump is to reduce cavitation stock. This leads to boiling of water by pressure reduction and rapid destruction the flow part of the pump