Polymorphism of lead(ii) benzenethiolate: a noncentrosymmetric new allotropic form of Pb(SPh)2

Depending upon its conditions of crystallization, lead(II) benzenethiolate can exist in two forms: a low-temperature centrosymmetric phase α-Pb(SPh)2 which can be converted by heating into the noncentrosymmetric, 2nd order NLO strongly active and room temperature metastable β-Pb(SPh)2 phase, thus affording an example of transition towards noncentrosymmetry induced by a rise of temperature

Construction of the probe beam photo-injector of CTF3

JACoW web site http://accelconf.web.cern.ch/AccelConf/e06This paper describes the HF (High-Frequency) and dynamic beam modelling performed onto the 3 GHz / 2,5 cells photo-injector of the future CTF3 (CLIC Test Facility 3) probe beam linac. The latter provides the beam to demonstrate the feasibility of the 30 GHz accelerating sections in the framework of the CLIC project. The Probe Beam Photo-Injector (PBPI) is inspired from the Drive Beam Photo-Injector (DBPI) already designed by LAL and actually tested in our laboratory. However, the design of PBPI has been simplified with respect to the previous because the charge per bunch is 4 times lower and the number of bunches several orders of magnitude smaller. The internal geometry and the coupling system of the PBPI have been designed with 2D (SUPERFISH*) and 3D (HFSS**) codes. Based on the modified design, PARMELA and POISSON simulations showed that the technical specifications are fulfilled. The vacuum issue has been also carefully investigated, and NEG (Non Evaporated Getter) technology has been adopted in order to reach the $10^–10$ mbar pressure inside the structure. This work is done in deep collaboration with CEA/Saclay, which is responsible of the CTF3 Probe Beam Linac design and construction [1]

The effects of room design on computer-supported collaborative learning in a multi-touch classroom.

While research indicates that technology can be useful for supporting learning and collaboration, there is still relatively little uptake or widespread implementation of these technologies in classrooms. In this paper, we explore one aspect of the development of a multi-touch classroom, looking at two different designs of the classroom environment to explore how classroom layout may influence group interaction and learning. Three classes of students working in groups of four were taught in the traditional forward-facing room condition, while three classes worked in a centered room condition. Our results indicate that while the outcomes on tasks were similar across conditions, groups engaged in more talk (but not more off-task talk) in a centered room layout, than in a traditional forward-facing room. These results suggest that the use of technology in the classroom may be influenced by the location of the technology, both in terms of the learning outcomes and the interaction behaviors of students. The findings highlight the importance of considering the learning environment when designing technology to support learning, and ensuring that integration of technology into formal learning environments is done with attention to how the technology may disrupt, or contribute to, the classroom interaction practices

Nitrogen leaching from organic agriculture and conventional crop rotations (France)

A great challenge to science is to elucidate how agriculture can feed the increasing world population without damaging the environment, while preserving other resources such as freshwater. In the Seine basin, characterised by intensive agriculture, most of surface and underground water is contaminated by nitrate. Conventional agriculture has regularly increased the use of industrial fertilisers since the WWII, leading to high nitrogen leaching, as shown by lysimeters or suction cup measurements. Such measurements are very scarce for other agricultural systems such as organic farming (Hansen et al. 2000; Haas et al. 2002; Mondelaers et al. 2009). The goal of our study is to investigate nitrogen leaching from organic agriculture, taking into account complete organic rotations (6-9 years). We hypothesize that leaching for organic farming is less than for conventional farming, although factors such as different practices, types of soil and age of conversion need to be taken into consideration. This work should have an impact on nitrogen sufficiency and management of organic practices

The domino effect and integrated probabilistic approaches for risk analysis

International audienceThe paper develops a probabilistic approach in order to deal with domino effects that may occur in industrial facilities : an explosion or accident may generate various sets of projectiles that may impact other existing facilities (tanks under high-pressure, etc) and may generate other sets of projectiles and so on. Three main parts are considered : 1- Source term : for the first set of generated projectiles, probabilistic distributions are considered for the number, masses, velocities, departure angles, geometrical form, dimensions, and constitutive materials properties. The authors have collected existing models from the literature. 2- Target term : for the set of impacted targets, probabilistic distributions are considered for the number of impacting projectiles, velocities, incidence angles and energy at impact, constitutive materials properties, dimensions of the impacted targets, and projectiles penetration depths into the targets. In this paper, new models for the impact are proposed to calculate the penetration depth after impact : case of cylindrical rods impacting rectangular plates, both are metal made. The theoretical results are compared to the experimental data (4 data sets) collected from the literature with the following features : projectiles mass ranging from 0.1g up to 250 kg, projectiles velocity ranging from 10 m/s up to 2100 m/s, projectiles diameters ranging from 1.5 mm up to 90 mm, target strength ranging from 300 MPa up to 1400 MPa and incidence angles ranging from 0 degree up to 70 degrees. 3- Domino effect term : evaluation of the risks of second set of explosions that may take place in the impacted components. Monte Carlo simulations are used in order to calculate the different probabilities : probability of impact, distribution of the penetration depth and probability of domino effect

PHIL: a Test Beam line at LAL

WEPP078International audienceIn the framework of a European contract*, LAL is in charge of the construction of one photo-injector for the drive beam linac of the CLIC Test Facility 3 [1] at CERN. This contract together with national funds allowed LAL to build a home test accelerator, PHIL, with the same photo-injector as for CTF3. The goal is to undergo experiments on the design and technology of advanced RF guns, to develop diagnostics and feedback techniques, a part of the beam time will be also shared with users of the electron beam. So far, the construction of this accelerator at LAL was very much delayed because of the legal obligation to upgrade the radiation shielding in agreement with the actual radiation safety thresholds. The required civil engineering is now finished and the installation of the components is under way. We will first present a design of the accelerator and few dynamic simulation results. Finally we will give an up to date status of the accelerator construction

Roundtable: Affordances, Diversity, and Inclusion on Dating Apps - A Dialogue between Sociologists and Media Studies Researchers about ‘Hinge’

This roundtable paper is part of the project ‘Digitized Love and Intimacy on Hinge.’ It aims to investigate how digital dating apps reconfigure cultural attitudes to love and intimacy and, conversely, how said attitudes influence digital dating practices. The conversation is informed by (n)ethnographic usage of the app. As algorithms and affordances of dating applications can implicitly or explicitly privilege certain groups of users and exclude others, this conversation mainly aims to make sense of how Hinge’s interface – or ‘affordances’– facilitates the dating process and how inclusive and diverse the application’s affordances are. We discuss that there is a contradiction between what Hinge portrays itself to be and what it practically ends up being, partly because of its affordances. This roundtable highlights the need to study affordances as relational technologies and to take the perceptions, ideas, and interpretations of users seriously alongside the actual features and designs offered by applications

Proenkephalin A 119-159 (Penkid) Is an Early Biomarker of Septic Acute Kidney Injury: The Kidney in Sepsis and Septic Shock (Kid-SSS) Study

Introduction: Sepsis is the leading cause of acute kidney injury (AKI) in critically ill patients. The Kidney in Sepsis and Septic Shock (Kid-SSS) study evaluated the value of proenkephalin A 119-159 (penkid)—a sensitive biomarker of glomerular function, drawn within 24 hours upon intensive care unit (ICU) admission and analyzed using a chemiluminescence immunoassay—for kidney events in sepsis and septic shock. Methods: The Kid-SSS study was a substudy of Adrenomedullin and Outcome in Severe Sepsis and Septic Shock (AdrenOSS) (NCT02393781), a prospective, observational, multinational study including 583 patients admitted to the intensive care unit with sepsis or septic shock and a validation cohort of 525 patients from the French and euRopean Outcome reGistry in Intensive Care Units (FROG-ICU) study. The primary endpoint was major adverse kidney events (MAKEs) at day 7, composite of death, renal replacement therapy, and persistent renal dysfunction. The secondary endpoints included AKI, transient AKI, worsening renal function (WRF), and 28-day mortality. Results: Median age was 66 years (interquartile range 55–75), and 28-day mortality was 22% (95% confidence interval [CI] 19%−25%). Of the patients, 293 (50.3%) were in shock upon ICU admission. Penkid was significantly elevated in patients with MAKEs, persistent AKI, and WRF (median = 65 [IQR = 45–106] vs. 179 [114–242]; 53 [39–70] vs. 133 [79–196] pmol/l; and 70 [47–121] vs. 174 [93–242] pmol/l, all P < 0.0001), also after adjustment for confounding factors (adjusted odds ratio = 3.3 [95% CI = 1.8–6.0], 3.9 [95% CI = 2.1–7.2], and 3.4 [95% CI = 1.9–6.2], all P < 0.0001). Penkid increase preceded elevation of serum creatinine with WRF and was low in renal recovery. Conclusion: Admission penkid concentration was associated with MAKEs, AKI, and WRF in a timely manner in septic patients

Diffuse reflection of a Bose-Einstein condensate from a rough evanescent wave mirror

We present experimental results showing the diffuse reflection of a Bose-Einstein condensate from a rough mirror, consisting of a dielectric substrate supporting a blue-detuned evanescent wave. The scattering is anisotropic, more pronounced in the direction of the surface propagation of the evanescent wave. These results agree very well with theoretical predictions.Comment: submitted to J Phys B, 10 pages, 6 figure