Optimal generalization of power filters for gravitational wave bursts, from single to multiple detectors

Searches for gravitational wave signals which do not have a precise model describing the shape of their waveforms are often performed using power detectors based on a quadratic form of the data. A new, optimal method of generalizing these power detectors so that they operate coherently over a network of interferometers is presented. Such a mode of operation is useful in obtaining better detection efficiencies, and better estimates of the position of the source of the gravitational wave signal. Numerical simulations based on a realistic, computationally efficient hierarchical implementation of the method are used to characterize its efficiency, for detection and for position estimation. The method is shown to be more efficient at detecting signals than an incoherent approach based on coincidences between lists of events. It is also shown to be capable of locating the position of the source.Comment: 16 pages, 5 figure

Water Quality at the Inlet to the St. Lawrence River, 1977 to 1983

Daily nutrients analyses and weekly major ions and trace metals analyses have been performed since 1977 on water samples collected in the south channel of the St. Lawrence River at Wolfe Island. This report presents the results of the first seven years of this program. Data analyses showed that pH and total phosphorus were underestimated. Calcium carbonate precipitation is suspected to occur almost every year in August or September. Most of the major ions have decreased, especially chloride and sodium. All trace metal data were below the objectives of the International Joint Commission in 90% of the cases or more. The Wolfe Island station was found to be a good tool for following the general trend of the main water quality parameters. More attention, however, should be focused on the problems of shipping delays and containers

Revisiting trajectories of BMI in youth : an in‐depth analysis of differences between BMI and other adiposity measures

Objective Body mass index (BMI) is used to identify trajectories of adiposity in youth, but it does not distinguish fat- from fat-free-mass. There are other inexpensive measures of adiposity which might better capture fat-mass in youth The objective of this study is to examine differences between sex-specific trajectories of BMI and other adiposity indicators (subscapular and triceps skinfold thickness, waist circumference, waist-to-height ratio) which may better capture fat-mass in youth. Methods Data come from four cycles of a longitudinal cohort of 1293 students in Montréal, Canada at ages 12, 15, 17 and 24. Group-based trajectory models identified sex-specific adiposity trajectories among participants with data in ≥3 cycles (n = 417 males; n = 445 females). Results There were six trajectory groups in males and females for all five indicators, except for waist circumference (seven) in both sexes and triceps skinfold thickness (four) and waist-to-height ratio (five) in females. Most trajectories indicated linear increases; only the skinfold thickness indicators identified a decreasing trajectory. While all indicators identified a trajectory with high levels of adiposity, they differed in the number and relative size of trajectories pertaining to individuals in lower half of the adiposity distribution. Conclusion BMI is a satisfactory indicator of adiposity in youth if the aim of the trajectory analysis is to identify youth with excess adiposity, a known risk factor for cardiometabolic outcomes in adulthood

Chalcogenide-glass polarization-maintaining photonic crystal fiber for mid-infrared supercontinuum generation

In this paper, we report the design and fabrication of a highly birefringent polarization-maintaining photonic crystal fiber (PM-PCF) made from chalcogenide glass, and its application to linearly-polarized supercontinuum (SC) generation in the mid-infrared region. The PM fiber was drawn using the casting method from As38Se62 glass which features a transmission window from 2 to 10 $\mu m$ and a high nonlinear index of 1.13.10$^{-17}$m$^{2}$W$^{-1}$. It has a zero-dispersion wavelength around 4.5 $\mu m$ and, at this wavelength, a large birefringence of 6.10$^{-4}$ and consequently strong polarization maintaining properties are expected. Using this fiber, we experimentally demonstrate supercontinuum generation spanning from 3.1-6.02 $\mu m$ and 3.33-5.78 $\mu m$ using femtosecond pumping at 4 $\mu m$ and 4.53 $\mu m$, respectively. We further investigate the supercontinuum bandwidth versus the input pump polarization angle and we show very good agreement with numerical simulations of the two-polarization model based on two coupled generalized nonlinear Schr\"odinger equations.Comment: 13 pages, 8 figure

Primordial and primary prevention of peri-implant diseases: A systematic review and meta-analysis

Aim: This systematic review and meta-analysis aims to assess the efficacy of risk factor control to prevent the occurrence of peri-implant diseases (PIDs) in adult patients awaiting dental implant rehabilitation (primordial prevention) or in patients with dental implants surrounded by healthy peri-implant tissues (primary prevention). Materials and Methods: A literature search was performed without any time limit on different databases up to August 2022. Interventional and observational studies with at least 6 months of follow-up were considered. The occurrence of peri-implant mucositis and/or peri-implantitis was the primary outcome. Pooled data analyses were performed using random effect models according to the type of risk factor and outcome. Results: Overall, 48 studies were selected. None assessed the efficacy of primordial preventive interventions for PIDs. Indirect evidence on the primary prevention of PID indicated that diabetic patients with dental implants and good glycaemic control have a significantly lower risk of peri-implantitis (odds ratio [OR] = 0.16; 95% confidence interval [CI]: 0.03–0.96; I2: 0%), and lower marginal bone level (MBL) changes (OR = –0.36 mm; 95% CI: −0.65 to −0.07; I2: 95%) compared to diabetic patients with poor glycaemic control. Patients attending supportive periodontal/peri-implant care (SPC) regularly have a lower risk of overall PIDs (OR = 0.42; 95% CI: 0.24–0.75; I2: 57%) and peri-implantitis compared to irregular attendees. The risk of dental implant failure (OR = 3.76; 95% CI: 1.50–9.45; I2: 0%) appears to be greater under irregular or no SPC than regular SPC. Implants sites with augmented peri-implant keratinized mucosa (PIKM) show lower peri-implant inflammation (SMD = –1.18; 95% CI: −1.85 to −0.51; I2: 69%) and lower MBL changes (MD = –0.25; 95% CI: −0.45 to −0.05; I2: 62%) compared to dental implants with PIKM deficiency. Studies on smoking cessation and oral hygiene behaviors were inconclusive. Conclusions: Within the limitations of available evidence, the present findings indicate that in patients with diabetes, glycaemic control should be promoted to avoid peri-implantitis development. The primary prevention of peri-implantitis should involve regular SPC. PIKM augmentation procedures, where a PIKM deficiency exists, may favour the control of peri-implant inflammation and the stability of MBL. Further studies are needed to assess the impact of smoking cessation and oral hygiene behaviours, as well as the implementation of standardized primordial and primary prevention protocols for PIDs

Demonstration of an integrated LiNbO3 Synchronized Double Phase Modulator and its Applications to Dual-Pump Fiber Optical Parametric Amplifiers and Wavelength Converters

International audienceWe report the fabrication of an integrated LiNbO3 Y-junction synchronized double phase modulator fully packaged for RF-application up to 40 GHz. This optical modulator allows for delivering simultaneously counter-phase high-speed modulation and coupling for two input channels. It was designed for application to fiber-optical parametric amplifier and wavelength converters for suppressing idler spectral broadening and signal gain distortion caused by phase modulation itself. With this component, Idler spectral broadening suppression is experimentally demonstrated over all the parametric gain band of a twopump parametric amplifier operating in the 1.55 µm region. In addition, we present a useful technique for straightforward and full coupling of the pumps and the signal

Complete compensation of criss-cross deflection in a negative ion accelerator by magnetic technique

During 2016, a joint experimental campaign was carried out by QST and Consorzio RFX on the Negative Ion Test Stand (NITS) at the QST Naka Fusion Institute, Japan, with the purpose of validating some design solutions adopted in MITICA, which is the full-scale prototype of the ITER NBI, presently under construction at Consorzio RFX, Padova, Italy. The main purpose of the campaign was to test a novel technique, for suppressing the beamlet criss-cross magnetic deflection. This new technique, involving a set of permanent magnets embedded in the Extraction Grid, named Asymmetric Deflection Compensation Magnets (ADCM), is potentially more performing and robust than the traditional electrostatic compensation methods. The results of this first campaign confirmed the effectiveness of the new magnetic configuration in reducing the criss-cross magnetic deflection. Nonetheless, contrary to expectations, a complete deflection correction was not achieved. By analyzing in detail the results, we found indications that a physical process, taking place just upstream of the plasma grid, was giving an important contribution to the final deflection of the negative ion beam. This process appears to be related to the drift of negative ions inside the plasma source, in the presence of a magnetic field transverse to the extraction direction, and results in a non-uniform ion current density extracted at the meniscus. Therefore, the numerical models adopted in the design were improved by including this previously disregarded effect, so as to obtain a much better matching with the experimental results. Based on the results of the first campaign, new permanent magnets were designed and installed on the Extraction Grid of NITS. A second QST-Consorzio RFX joint experimental campaign was then carried out in 2017, demonstrating the complete correction of the criss-cross deflection and confirming the validity of the novel magnetic configuration and of the hypothesis behind the new models. This contribution presents the results of the second joint experimental campaign on NITS along with the overall data analysis of both campaigns, and the description of the improved models. A general picture is given of the relation among magnetic field, beam energy, meniscus non-uniformity and beamlet deflection, constituting a useful database for the design of future machines

La dynamique paradoxale de l'EEE

À l’université, l’évaluation de l’enseignement par les étudiants (EEE) est un champ de recherches et de pratiques particulièrement sensible en raison de sa dimension paradoxale. Malgré des pratiques qui tendent à se développer dans le domaine et les nombreuses recherches auxquelles elle a donné lieu, dans certains contextes, l’expérience des enseignants, des responsables et des étudiants en la matière reste encore souvent limitée. L’EEE reste toujours sujette à de vives controverses, dans son adoption ou dans son rejet, et ce pour des raisons différentes. L’analyse de son cheminement en Amérique du Nord, où il s’agit d’une pratique systématique, et en Europe, où elle est encore dans de nombreux cas en phase d’implantation, montre les fluctuations des orientations politiques et les sérieuses difficultés pour en faire un instrument efficace au service de l’amélioration de l’enseignement universitaire (Younès, 2009a). Il est communément admis que le renforcement de l’EEE en Europe s’inscrit dans le cadre du processus de Bologne et de la mise en place de l’espace européen de l’enseignement supérieur (Rege Colet, 2010). Les politiques évaluatives et les dispositifs d’évaluation de l’enseignement et des formations développés dans ce sillon sont tous imprégnés de principes consistant, d’une part, à recourir à des méthodologies d’évaluation de la qualité communes et, d’autre part, à implémenter des politiques et des procédures qui impliquent la participation de tous les acteurs avec une mention spéciale en faveur d’une contribution soutenue de la part des étudiants. Relayées par les politiques nationales, ces lignes directrices appellent le développement de procédures d’évaluation de l’enseignement par les étudiants, confrontant des procédures génériques à des ajustements aux milieux concernés, ce qui implique d’accorder une grande attention aux acteurs et en particulier aux étudiants quant à leurs représentations, positions et pratiques effectives. Cette dynamique de l’EEE se trouve prise entre différentes tensions : a) les finalités, entre démarche formative et outil de contrôle ; b) la pertinence et la validité de l’EEE ; et c) l’implication des acteurs et leur rapport à la culture qualité. Ce sont ces trois dimensions que nous explorons dans la présente note de synthèse

Space charge behaviour in epoxy laminates under high constant electric field

The development of space charge in insulating materials is one of the main causes of their electrical ageing. The pulsed electro-acoustic method is often used to determine space charge distribution, but the signal analysis in the case of laminate structures is much more complex to analyse. In this paper the authors describe and use a simulated signal in order to study laminates made of epoxy resin and fibre mat. The relatively large conductivity of the fibres compared with that of the resin seems to produce a rapid charge dissociation and recombination in the fibres. Under voltage the presence of fibres close to an electrode seems to promote charge injection

Discrete time measures versus trajectories of drinking frequency across adolescence as predictors of binge drinking in young adulthood: a longitudinal investigation

OBJECTIVES: We compared discrete time measures with trajectories of adolescent drinking frequency as predictors of sustained binge drinking in young adulthood. DESIGN: Prospective longitudinal study. SETTING: 10 high schools in Montreal, Canada. PARTICIPANTS: 1293 high-school students followed from mean (SD) age 12 (0.6) to 24 (0.7) years. PRIMARY OUTCOME MEASURES: Patterns of drinking frequency (self-reports every 3 months from ages 12 to 17) identified using group-based trajectory modelling. Sustained binge drinking was defined as binging monthly or more often at both ages 20 and 24. ANALYSES: Using logistic regression, sustained binge drinking was regressed on trajectory group membership and on four discrete time measures (frequency of drinking at age 12; frequency of drinking at age 17; age at drinking onset; age at onset of drinking monthly or more often). RESULTS: We identified seven drinking trajectories: late triers (15.2%), decreasers (9.5%), late escalators (10.4%), early slow escalators (16.5%), steady drinkers (14.4%), early rapid escalators (15.8%) and early frequent drinkers (18.2%). Sustained binge drinking was reported by 260 of 787 participants (33.0%) with complete data at both ages 20 and 24. Decreasers did not differ from late triers; all other patterns were associated with higher odds of sustained binge drinking (adjusted ORs: AORs=1.4-17.0). All discrete time measures were associated with sustained binge drinking, notably frequency at age 12 (a bit to try and drinking monthly: (AORs=2.6 (1.7; 3.9) and 2.8 (1.3; 6.1), respectively), age of drinking onset \u3c 13 years (AOR=7.6 (3.0; 24.1)), and any age of onset of drinking monthly or more often (AORs=5.1-8.2). CONCLUSION: Youth at risk of sustained binge drinking as young adults can be identified with indicators of early drinking as early as 7th grade (aged 12-13 years). Identification of easy-to-obtain indicators can facilitate screening and intervention efforts