Laser impulse coupling measurements at 400 fs and 80 ps using the LULI facility at 1057 nm wavelength

At the École Polytechnique « LULI » facility, we have measured the impulse coupling coefficient Cm (target momentum per joule of incident laser light) with several target materials in vacuum, at 1057 nm and 400 fs and 80 ps pulse duration. A total of 64 laser shots were completed in a two-week experimental campaign, divided between the two pulse durations and among the materials. Our main purpose was to resolve wide discrepancies among reported values for Cm in the 100 ps region, where many applications exist. A secondary purpose was to compare Cm at 400 fs and 80 ps pulse duration. The 80 ps pulse was obtained by partial compression. Materials were Al, Ta, W, Au, and POM (polyoxymethylene, trade name Delrin). One application of these results is to pulsed laser ablation propulsion in space, including space debris re-entry, where narrow ranges in Cm and specific impulse Isp spell the difference between dramatic and uneconomical performance. We had difficulty measuring mass loss from single shots. Imparted momentum in single laser shots was determined using pendulum deflection and photonic Doppler velocimetry. Cm was smaller at the 400 fs pulse duration than at 80 ps. To our surprise, Cm for Al at 80 ps was at most 30 N/MW with 30 kJ/m2 incident fluence. On the other extreme, polyoxymethylene (POM, trade name Delrin) demonstrated 770 N/MW under these conditions. Together, these results offer the possibility of designing a Cm value suited to an application, by mixing the materials appropriately

Transfers from Earth to LEO and LEO to interplanetary space using lasers

New data on some materials at 80ps pulse duration and 1057 nm wavelength give us the option of proportionally combining them to obtain arbitrary values between 35 (aluminum) and 800 N/MW (POM, polyoxymethylene) for momentum coupling coefficient Cm. Laser ablation physics lets us transfer to LEO from Earth, or to interplanetary space using repetitively pulsed lasers and Cm values appropriate for each mission. We discuss practical results for lifting small payloads from Earth to LEO, and space missions such as a cis-Mars orbit with associated laser system parameters

Cancer during Adolescence: Negative and Positive Consequences Reported Three and Four Years after Diagnosis

Persons diagnosed with cancer during adolescence have reported negative and positive cancer-related consequences two years after diagnosis. The overall aim was to longitudinally describe negative and positive cancer-related consequences reported by the same persons three and four years after diagnosis. A secondary aim was to explore whether reports of using vs. not using certain coping strategies shortly after diagnosis are related to reporting or not reporting certain consequences four years after diagnosis. Thirty-two participants answered questions about coping strategies shortly after diagnosis and negative and positive consequences three and four years after diagnosis. Answers about consequences were analysed with content analysis, potential relations between coping strategies and consequences were analysed by Fisher's exact test. The great majority reported negative and positive consequences three and four years after diagnosis and the findings indicate stability over time with regard to perceived consequences during the extended phase of survival. Findings reveal a potential relation between seeking information shortly after diagnosis and reporting a more positive view of life four years after diagnosis and not using fighting spirit shortly after diagnosis and not reporting good self-esteem and good relations four years after diagnosis. It is concluded that concomitant negative and positive cancer-related consequences appear stable over time in the extended phase of survival and that dialectical forces of negative and positive as well as distress and growth often go hand-in-hand after a trauma such as cancer during adolescence

PMIP4-CMIP6: the contribution of the Paleoclimate Modelling Intercomparison Project to CMIP6

The goal of the Palaeoclimate Modelling Intercomparison Project (PMIP) is to understand the response of the climate system to changes in different climate forcings and to feedbacks. Through comparison with observations of the environmental impacts of these climate changes, or with climate reconstructions based on physical, chemical or biological records, PMIP also addresses the issue of how well state-of-the-art models simulate climate changes. Palaeoclimate states are radically different from those of the recent past documented by the instrumental record and thus provide an out-of-sample test of the models used for future climate projections and a way to assess whether they have the correct sensitivity to forcings and feedbacks. Five distinctly different periods have been selected as focus for the core palaeoclimate experiments that are designed to contribute to the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6). This manuscript describes the motivation for the choice of these periods and the design of the numerical experiments, with a focus upon their novel features compared to the experiments performed in previous phases of PMIP and CMIP as well as the benefits of common analyses of the models across multiple climate states. It also describes the information needed to document each experiment and the model outputs required for analysis and benchmarking

Satisfaction with web-based training in an integrated healthcare delivery network: do age, education, computer skills and attitudes matter?

<p>Abstract</p> <p>Background</p> <p>Healthcare institutions spend enormous time and effort to train their workforce. Web-based training can potentially streamline this process. However the deployment of web-based training in a large-scale setting with a diverse healthcare workforce has not been evaluated. The aim of this study was to evaluate the satisfaction of healthcare professionals with web-based training and to determine the predictors of such satisfaction including age, education status and computer proficiency.</p> <p>Methods</p> <p>Observational, cross-sectional survey of healthcare professionals from six hospital systems in an integrated delivery network. We measured overall satisfaction to web-based training and response to survey items measuring Website Usability, Course Usefulness, Instructional Design Effectiveness, Computer Proficiency and Self-learning Attitude.</p> <p>Results</p> <p>A total of 17,891 healthcare professionals completed the web-based training on HIPAA Privacy Rule; and of these, 13,537 completed the survey (response rate 75.6%). Overall course satisfaction was good (median, 4; scale, 1 to 5) with more than 75% of the respondents satisfied with the training (rating 4 or 5) and 65% preferring web-based training over traditional instructor-led training (rating 4 or 5). Multivariable ordinal regression revealed 3 key predictors of satisfaction with web-based training: Instructional Design Effectiveness, Website Usability and Course Usefulness. Demographic predictors such as gender, age and education did not have an effect on satisfaction.</p> <p>Conclusion</p> <p>The study shows that web-based training when tailored to learners' background, is perceived as a satisfactory mode of learning by an interdisciplinary group of healthcare professionals, irrespective of age, education level or prior computer experience. Future studies should aim to measure the long-term outcomes of web-based training.</p

Crustal structure of the Mid-Atlantic Ridge south of the Kane Fracture Zone from seafloor and sea surface gravity data

International audienceSeafloor and sea surface gravity data are inverted together to construct a model for the near-axis crustal structure of a slow spreading ridge. The seafloor data set offers two main advantages: it allows us to recover shorter-wavelengths signal and to constrain the value of a potential field at two different levels. The model we propose here would not have been derived from sea surface data alone. It is based on a dense sea surface gravity coverage and on 121 sea bottom gravity measurements collected in the Mid-Atlantic Ridge at Kane (MARK) area, during the Hydrosnake (1988) and Gravinaute (1993) cruises. The primary goal of the seafloor surveys was to test for the presence of a magma reservoir beneath the axial neovolcanic ridge. First, a forward two-dimensional (2-D) model of the crustal structure across the axis is fit to observed gravity anomalies, using constraints from geological and structural observations. Bouguer anomalies computed from sea bottom measurements and downward continuation of sea surface measurements both constrain the forward modeling. This forward model is the starting point of a 2-D Monte Carlo inversion of seafloor and sea surface data. In addition to the crustal thickness variations along-axis, our data document the amplitude variations of the crustal thickness and/or its density in the across-axis direction. The model resulting from our inversion exhibits several features of the crustal structure in the MARK area: (1) The presence of a low-density (Ap =-300_+ 50 kg/m 3) body beneath the neovolcanic ridge is suggested and could correspond to a magma chamber, or more probably to a highly hydrothermally fissured zone. (2) Both long-and short-wavelength gravity signals exhibit a difference between the western and eastern sides of the axial domain: the mean value and the amplitude of Bouguer anomalies are higher on the western part. This difference suggests that axial processes, in this area, are very asymmetric. (3) Abyssal hills are not associated with a single gravity signature: for instance, on the west side of the axis, one of the explored hills has no Bouguer anomaly and is interpreted as a neovolcanic ridge, whereas the others are associated with a shifted Bouguer anomaly high and are interpreted as having thinner magmatic crust. (4) The last feature of the crustal fabric we document here is the asymmetric emplacement of some deep rocks outcrops. In the MARK area, we find that "Pink Hill," a topographic high where serpentinized peridotites are outcropping, is much more serpentinized on its east flank, toward the axial valley, than on its west flank. Alteration occurring mainly by fluid circulation through faulted zones, the asymmetric serpentinization suggests that deep-origin rocks have outcropped by means of a main fault zone and are not emplaced by diapirism

Interleukin-17 regulation: an attractive therapeutic approach for asthma

Interleukin (IL)-17 is recognized to play a critical role in numerous immune and inflammatory responses by regulating the expression of various inflammatory mediators, which include cytokines, chemokines, and adhesion molecules. There is growing evidence that IL-17 is involved in the pathogenesis of asthma. IL-17 orchestrates the neutrophilic influx into the airways and also enhances T-helper 2 (Th2) cell-mediated eosinophilic airway inflammation in asthma. Recent studies have demonstrated that not only inhibitor of IL-17 per se but also diverse regulators of IL-17 expression reduce antigen-induced airway inflammation, bronchial hyperresponsiveness, and Th2 cytokine levels in animal models of asthma. This review will summarize the role of IL-17 in the context of allergic airway inflammation and discuss the therapeutic potential of various strategies targeting IL-17 for asthma

Patterns of HIV-1 Protein Interaction Identify Perturbed Host-Cellular Subsystems

Human immunodeficiency virus type 1 (HIV-1) exploits a diverse array of host cell functions in order to replicate. This is mediated through a network of virus-host interactions. A variety of recent studies have catalogued this information. In particular the HIV-1, Human Protein Interaction Database (HHPID) has provided a unique depth of protein interaction detail. However, as a map of HIV-1 infection, the HHPID is problematic, as it contains curation error and redundancy; in addition, it is based on a heterogeneous set of experimental methods. Based on identifying shared patterns of HIV-host interaction, we have developed a novel methodology to delimit the core set of host-cellular functions and their associated perturbation from the HHPID. Initially, using biclustering, we identify 279 significant sets of host proteins that undergo the same types of interaction. The functional cohesiveness of these protein sets was validated using a human protein-protein interaction network, gene ontology annotation and sequence similarity. Next, using a distance measure, we group host protein sets and identify 37 distinct higher-level subsystems. We further demonstrate the biological significance of these subsystems by cross-referencing with global siRNA screens that have been used to detect host factors necessary for HIV-1 replication, and investigate the seemingly small intersect between these data sets. Our results highlight significant host-cell subsystems that are perturbed during the course of HIV-1 infection. Moreover, we characterise the patterns of interaction that contribute to these perturbations. Thus, our work disentangles the complex set of HIV-1-host protein interactions in the HHPID, reconciles these with siRNA screens and provides an accessible and interpretable map of infection