Experimental generalized quantum suppression law in Sylvester interferometers

Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling machines. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong-Ou-Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression is stronger than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference.Comment: 5 pages, 3 figures + 11 pages, 3 figures Supplementary Informatio

Air-core fiber distribution of hybrid vector vortex-polarization entangled states

Entanglement distribution between distant parties is one of the most important and challenging tasks in quantum communication. Distribution of photonic entangled states using optical fiber links is a fundamental building block towards quantum networks. Among the different degrees of freedom, orbital angular momentum (OAM) is one of the most promising due to its natural capability to encode high dimensional quantum states. In this article, we experimentally demonstrate fiber distribution of hybrid polarization-vector vortex entangled photon pairs. To this end, we exploit a recently developed air-core fiber which supports OAM modes. High fidelity distribution of the entangled states is demonstrated by performing quantum state tomography in the polarization-OAM Hilbert space after fiber propagation, and by violations of Bell inequalities and multipartite entanglement tests. The present results open new scenarios for quantum applications where correlated complex states can be transmitted by exploiting the vectorial nature of light

Autonomy Supportive Contexts, Autonomous Motivation, and Self-Efficacy Predict Academic Adjustment of First-Year University Students

Aim: The purpose of this study was to investigate the process that lead to academic adjustment of undergraduate students in the first year of higher education, by testing a predictive model based on self-determination theory with the inclusion of self-efficacy. The model posits that perceived autonomous forms of support from parents and teachers foster autonomous motivation and self-efficacy, which in turn predict academic adjustment.Method: A two-wave prospective design was adopted. Freshman students at an Italian university (N = 388; 73.5% females, Mage = 21.38 years ± 4.84) completed measures of autonomous motivation, perceived autonomy support from parents and teachers, self-efficacy, and intention to drop out from university at the start of their academic year. Students' past performance and socioeconomic background were also measured. At the end of the first semester, information about number of course modules passed and credits attained for each student were obtained from the department office and matched with the data collected in the first wave by an identification number.Results: Findings of structural equation modeling analysis supported the proposed model for first-year university students, after controlling for the influence of past performance and socioeconomic background. Specifically, autonomous motivation and self-efficacy predicted dropout intention and academic adjustment a few months later. Autonomous motivation and self-efficacy were encouraged by autonomy supportive behaviors provided by teachers and parents.Conclusion: According to our findings, in order to promote higher degree of academic adjustment in freshman students, interventions should aim to encourage autonomous motivation and self-efficacy through autonomous supportive behavior from the university and the family contexts

MicroMED: a dust particle counter for the characterization of airborne dust close to the surface of Mars

Monitoring of airborne dust is very important in planetary climatology. Indeed, dust absorbs and scatter solar and thermal radiation, severely affecting atmospheric thermal structure, balance and dynamics (in terms of circulations). Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. Dust is permanently present in the atmosphere of Mars and its amount varies with seasons. During regional or global dust storms, more than 80% of the incoming sunlight is absorbed by dust causing an intense atmospheric heating. Airborne dust is therefore a crucial climate component on Mars which impacts atmospheric circulations at all scales. Main dust parameters influencing the atmosphere heating are size distribution, abundance, albedo, single scattering phase function, imaginary part of the index of refraction. Moreover, major improvements of Mars climate models require, in addition to the standard meteorological parameters, quantitative information about dust lifting, transport and removal mechanisms. In this context, two major quantities need to be measured for the dust source to be understood: surface flux and granulometry. While many observations have constrained the size distribution of the dust haze seen from the orbit, it is still not known what the primary airborne dust (e.g. the recently lifted dust) is made of, size-wise. MicroMED has been designed to fill this gap. It will measure the abundance and size distribution of dust, not in the atmospheric column, but close to the surface, where dust is lifted, so to be able to monitor dust injection into the atmosphere. This has never been performed in Mars and other planets exploration. MicroMED is an Optical Particle Counter, analyzing light scattered from single dust particles to measure their size and abundance. A proper fluid-dynamic system, including a pump and a sampling head, allows the sampling of Martian atmosphere with embedded dust. The captured dust grains are detected by an Optical System and then ejected into the atmosphere. MicroMED is a miniaturization of the instrument MEDUSA, developed for the Humboldt payload of the ExoMars mission. An Elegant Breadboard has been developed and tested and successfully demonstrates the instrument performances. The design and performance test results will be discussed

RELATION BETWEEN MATERNAL THROMBOPHILIA AND STILLBIRTH ACCORDING TO CAUSES/ASSOCIATED CONDITIONS OF DEATH

OBJECTIVE: To investigate maternal thrombophilia in cases of Stillbirth (SB), also an uncertain topic because most case series were not characterised for cause/associated conditions of death. STUDY DESIGN: In a consecutive, prospective, multicentre design, maternal DNA was obtained in 171 cases of antenatal SB and 326 controls (uneventful pregnancy at term, 1:2 ratio). Diagnostic work-up of SB included obstetric history, neonatologist inspection, placenta histology, autopsy, microbiology/chromosome evaluations. Results audited in each centre were classified by two of us by using CoDAC. Cases were subdivided into explained SB where a cause of death was identified and although no defined cause was detected in the remnants, 64 cases found conditions associated with placenta-vascular disorders (including preeclampsia, growth restriction and placenta abruption - PVD). In the remnant 79 cases, no cause of death or associated condition was found. Antithrombin activity, Factor V Leiden, G20210A Prothrombin mutation (FII mutation) and acquired thrombophilia were analysed. RESULTS: Overall, the presence of a thrombophilic defect was significantly more prevalent in mothers with SBs compared to controls. In particular, SB mothers showed an increased risk of carrying Factor II mutation (OR=3.2, 95\% CI: 1.3-8.3, p=0.01), namely in unexplained cases. Such mutation was significantly associated also with previous SB (OR=8.9, 95\%CI 1.2-70.5). At multiple logistic regression, Factor II mutation was the only significantly associated variable with SB (adj OR=3.8, 95\% CI: 1.3-13.5). CONCLUSION: These data suggest that Factor II mutation is the only condition specifically associated with unexplained SB and could represents a risk of recurrence. PVD-associated condition is unrelated to thrombophilia

MicroMED: an optical particle counter for the direct in situ measurement of abundance and size distribution of dust suspended in the atmosphere of Mars

The MicroMED experiment has been developed for the characterization of airborne dust close to the surface of Mars and is suitable to be accommodated on Martian landers or rovers. It is an optical particle counter, analyzing light scattered from single dust particles to measure their size and abundance. An Elegant Breadboard of the instrument has been realized and successfully tested in a Martian simulated environment. Test results demonstrate the expected functionality and performances of the experiment. <P /

Adolescents’ Characteristics and Peer Relationships in Class: A Population Study

Abstract: Background: This study aimed to investigate differences in adolescents’ social relationships with classmates of diverse gender, socioeconomic status, immigrant background, and academic achievement. Methods: A population of 10th-grade students (N = 406,783; males = 50.3%; Mage = 15.57 years, SDage = 0.75) completed the Classmates Social Isolation Questionnaire (CSIQ), an instrument specifically designed to measure two distinct but correlated types of peer relationships in class: peer acceptance and peer friendship. To obtain reliable comparisons across diverse adolescent characteristics, the measurement invariance of the CSIQ was established by means of CFAs and then latent mean differences tests were performed. Results: Immigrant background, academic achievement, and socioeconomic status all proved to be important factors influencing relationships with classmates, while being a male or a female was less relevant. Being a first-generation immigrant adolescent appears to be the foremost risk factor for being less accepted by classmates, while having a low academic achievement is the greatest hindrance for having friends in the group of classmates, a finding that diverges from previous studies. Conclusions: This population study suggests that adolescent characteristics (especially immigrant background, socioeconomic status, and academic achievement) seem to affect social relationships with classmates

Design and CFD Analysis of the Fluid Dynamic Sampling System of the “MicroMED” Optical Particle Counter

MicroMED is an optical particle counter that will be part of the ExoMars 2020 mission. Its goal is to provide the first ever in situ measurements of both size distribution and concentration of airborne Martian dust. The instrument samples Martian air, and it is based on an optical system that illuminates the sucked fluid by means of a collimated laser beam and detects embedded dust particles through their scattered light. By analyzing the scattered light profile, it is possible to obtain information about the dust grain size and speed. To do that, MicroMED’s fluid dynamic design should allow dust grains to cross the laser-illuminated sensing volume. The instrument’s Elegant Breadboard was previously developed and tested, and Computational Fluid Dynamic (CFD) analysis enabled determining its criticalities. The present work describes how the design criticalities were solved by means of a CFD simulation campaign. At the same time, it was possible to experimentally validate the results of the analysis. The updated design was then implemented to MicroMED’s Flight Model

Electric properties of dust devils

Dust devils are one of the most effective phenomena able to inject dust grains into the atmosphere. On Mars, they play an important role to maintain the haze and can significantly affect the global dust loading, especially outside the dust storm season. Despite dust devils having been studied for a century and a half, many open questions regarding their physics still exist. In particular, the nature of the dust lifting mechanisms inside the vortices, the development of the induced electric field and the exact contribution to the global atmospheric dust budget are still debated topics. In this paper, we analyze the dust devil activity observed in the Moroccan Sahara desert during a 2014 field campaign. We have acquired the most comprehensive field data set presently available for the dust devils: including meteorological, atmospheric electric field and lifted dust concentration measurements. We focus our attention on the electric field induced by vortices, using this as the principal detection parameter. We present, for the first time, the statistical distribution of dust devil electric field and its relationships with the pressure drop, the horizontal and vertical vortex velocity and the total dust mass lifted. We also compare the pressure drop distribution of our sample with the ones observed on the martian surface showing the similarity of the dust devils samples and the usefulness of this study for the next martian surface missions

Evaluation of quantitative fFn test in predicting the risk of preterm birth

To evaluate diagnostic accuracy of quantitative fetal fibronectin (qfFN) test in predicting preterm birth (PTB) risk &lt;34 weeks' gestation or within 14 days from testing. We explored the predictive potential of the test in five-predefined PTB risk categories based on predefined qfFN thresholds (&lt;10, 10-49, 50-199, 200-499 and ≥500 ng/mL)