Ultrafast electro-nuclear dynamics of H2 double ionization

The ultrafast electronic and nuclear dynamics of H2 laser-induced double ionization is studied using a time-dependent wave packet approach that goes beyond the fixed nuclei approximation. The double ionization pathways are analyzed by following the evolution of the total wave function during and after the pulse. The rescattering of the first ionized electron produces a coherent superposition of excited molecular states which presents a pronounced transient H+H- character. This attosecond excitation is followed by field-induced double ionization and by the formation of short-lived autoionizing states which decay via double ionization. These two double ionization mechanisms may be identified by their signature imprinted in the kinetic-energy distribution of the ejected protons

Skorohod-Olevsky viscous sintering model sensitivity to temperature distribution during the sintering process

U ovom radu proučavan je uticaj neuniformnosti temperaturnog polja po uzorku na rezultate simulacije procesa sinterovanja. Kao konstitutivni model ponašanja materijala upotrebljen je modifikovan fenomenološki Skorohod-Olevski viskozni model sinterovanja. Poređeni su rezultati simulacije dobijeni korišćenjem uniformne raspodele temperature, sa rezultatima koji koriste temperaturno polje dobijeno simulacijom zagrevanj auzorka. Poređenja se odnose na uzorke različiti hveličina, kako bi se ispitao različiti nivo neuniformnosti. Dobijeni rezultati u ovoj studiji pokazuju da postoje situacije u kojima je potrebno uzeti u obzir neuniformnost raspodele temperature po uzorku, odnosno da pojednostavljenje modela korišćenjem uniformne raspodele dovodi do neprihvatljivih grešaka.This paper investigates the influence of temperature field non-uniformity on sintering simulation results using the Skorohod-Olevsky viscous sintering model. As a difference to previous studies, here a thermal transient analysis is performed to provide a detailed temperature field over the component within sintering time. Results obtained using uniform temperature distribution are compared to those obtained using a nonuniform distribution derived from a transient thermal analysis. Results are compared for different geometry sizes, that lead to different temperature non-uniformity levels. The study has shown that the temperature nonuniformity cannot always be neglected and should be considered as a possible source of modeling error

Ultrafast Molecular Imaging by Laser Induced Electron Diffraction

We address the feasibility of imaging geometric and orbital structure of a polyatomic molecule on an attosecond time-scale using the laser induced electron diffraction (LIED) technique. We present numerical results for the highest molecular orbitals of the CO2 molecule excited by a near infrared few-cycle laser pulse. The molecular geometry (bond-lengths) is determined within 3% of accuracy from a diffraction pattern which also reflects the nodal properties of the initial molecular orbital. Robustness of the structure determination is discussed with respect to vibrational and rotational motions with a complete interpretation of the laser-induced mechanisms

Skorohod-Olevsky viscous sintering model sensitivity to temperature distribution during the sintering process

U ovom radu proučavan je uticaj neuniformnosti temperaturnog polja po uzorku na rezultate simulacije procesa sinterovanja. Kao konstitutivni model ponašanja materijala upotrebljen je modifikovan fenomenološki Skorohod-Olevski viskozni model sinterovanja. Poređeni su rezultati simulacije dobijeni korišćenjem uniformne raspodele temperature, sa rezultatima koji koriste temperaturno polje dobijeno simulacijom zagrevanj auzorka. Poređenja se odnose na uzorke različiti hveličina, kako bi se ispitao različiti nivo neuniformnosti. Dobijeni rezultati u ovoj studiji pokazuju da postoje situacije u kojima je potrebno uzeti u obzir neuniformnost raspodele temperature po uzorku, odnosno da pojednostavljenje modela korišćenjem uniformne raspodele dovodi do neprihvatljivih grešaka.This paper investigates the influence of temperature field non-uniformity on sintering simulation results using the Skorohod-Olevsky viscous sintering model. As a difference to previous studies, here a thermal transient analysis is performed to provide a detailed temperature field over the component within sintering time. Results obtained using uniform temperature distribution are compared to those obtained using a nonuniform distribution derived from a transient thermal analysis. Results are compared for different geometry sizes, that lead to different temperature non-uniformity levels. The study has shown that the temperature nonuniformity cannot always be neglected and should be considered as a possible source of modeling error

Risk factors for fatal and nonfatal repetition of suicide attempts: a literature review

Objectives: This review aimed to identify the evidence for predictors of repetition of suicide attempts, and more specifically for subsequent completed suicide. Methods: We conducted a literature search of PubMed and Embase between January 1, 1991 and December 31, 2009, and we excluded studies investigating only special populations (eg, male and female only, children and adolescents, elderly, a specific psychiatric disorder) and studies with sample size fewer than 50 patients. Results: The strongest predictor of a repeated attempt is a previous attempt, followed by being a victim of sexual abuse, poor global functioning, having a psychiatric disorder, being on psychiatric treatment, depression, anxiety, and alcohol abuse or dependence. For other variables examined (Caucasian ethnicity, having a criminal record, having any mood disorders, bad family environment, and impulsivity) there are indications for a putative correlation as well. For completed suicide, the strongest predictors are older age, suicide ideation, and history of suicide attempt. Living alone, male sex, and alcohol abuse are weakly predictive with a positive correlation (but sustained by very scarce data) for poor impulsivity and a somatic diagnosis. Conclusion: It is difficult to find predictors for repetition of nonfatal suicide attempts, and even more difficult to identify predictors of completed suicide. Suicide ideation and alcohol or substance abuse/dependence, which are, along with depression, the most consistent predictors for initial nonfatal attempt and suicide, are not consistently reported to be very strong predictors for nonfatal repetition

Signal Processing Methodology of Response Data from a Historical Arch Bridge toward Reliable Modal Identification

The paper is part of a case study concerning the structural assessment of a historical infrastructure in the local territory, a road three-span reinforced concrete arch bridge over a river, built by the end of World War I (1917). The purpose of the paper is twofold: first, in-situ acquired response data are systematically analysed by specific signal processing techniques, to form a devoted methodological procedure and to extract useful information toward possible interpretation of the current structural conditions; second, the deciphered information is elaborated, in view of obtaining peculiar conceptualisations of detailed features of the structural response, as meant to achieve quantitative descriptions and modelling, for final Structural Health Monitoring (SHM) and intervention purposes. The proposed methodology, integrating self-implemented and adapted classical signal processing methods, and refined techniques, such as Wavelet analysis and ARMA models, assembles a rather general, systematic methodological approach to signal processing, highlighting the capability to extract useful and fundamental information from acquired response data, also endowed of a non-stationary character, toward final structural interpretation, identification and modelling, thus enabling for developing a reliable and effective SHM platform, on strategic ageing infrastructures. For the present case study, non-stationary characteristics of the response signals are revealed and flattened out, to identify the underlying fundamental frequencies of the infrastructure and to advance particular interpretations of its current structural behaviour, in forming an enlarging structural consciousness of the bridge at hand

Effects of lockdown on emergency room admissions for psychiatric evaluation: an observational study from the AUSL Romagna, Italy

Objectives: An observation of the admissions to the emergency room (ER) requiring psychiatric evaluation during the lockdown and investigation of the demographic and clinical variables. Methods: Retrospective longitudinal observational study of ER accesses for psychiatric evaluation was performed, comparing two periods (9 March–3 May 2020 vs. 9 March–3 May 2019). Data (number of admissions, key baseline demographic and clinical variables) were extracted from the ER databases of referral centres in a well-defined geographic area of North-Eastern Italy (Cesena, Ravenna, Forlì, and Rimini). Results: A 15% reduction of psychiatric referrals was observed, together with a 17% reduction in the total number of patients referring to the ER. This reduction was most evident in the first month of the lockdown period (almost 25% reduction of both referrals and patients). Female gender (OR: 1.52: 95%, CI: 1.12–2.06) and being a local resident (OR: 1.54: 95%CI: 1.02–2.34) were factors associated with the decrease. Conclusions: Lockdown changed dramatically health priorities in the local population, including people with mental health. We speculate that our observations do not only refer to the confinement due to the lockdown regime but also to fear of contagion and adoption of different coping strategies, especially in women.Key-points During lockdown 15% reduction of psychiatric visits and >17% reduction in the number of psychiatric patients referring to the ER was observed. in the first four weeks of the lockdown almost 25% reduction of both visits and patients was observed Female gender and being a local resident were factors associated with the decrease

Mid-term psychiatric consequences of the COVID-19 pandemic: a 4 months observational study on emergency room admissions for psychiatric evaluation after the (first) lockdown period in Italy

Purpose: The aim of our study is to evaluate the number and the features of admissions to the emergency room (ER) requiring psychiatric consultation, in the period between May 4th and August 31st 2020. Methods: We carried out a retrospective longitudinal observational study examining the 4 months following the initial lockdown imposed during the COVID-19 outbreak (May 4th and August 31st 2020). More specifically, the ER admissions leading to psychiatric referral were reviewed at all seven public hospitals of AUSL Romagna (Emilia Romagna region, Italy). Socio-demographic variables, history of medical comorbidities or psychiatric disorders, reason for ER admission, psychiatric diagnosis at discharge, and actions taken by the psychiatrist were collected. Results: An 11.3% (p = 0.007) increase in psychiatric assessments was observed when compared with the same period of the previous year (2019). A positive personal history of psychiatric disorders (OR:0.68, CI: 0.53–0.87) and assessments leading to no indication for follow-up (OR: 0.22, CI: 0.13–0.39) were significantly less frequent, while there was a significant increase of cases featuring organic comorbidities (OR: 1.24, CI: 1.00–1.52) and suicidal ideation/self-harm/suicide attempt (OR: 1,71, CI: 1.19–2.45) or psychomotor agitation (OR: 1.46, CI: 1.02–2.07) as reason for admission. Conclusions: Our results showed an increase in ER psychiatric consultations compared to the previous year, underlying the increased psychological distress caused by the lockdown

Diagenetic Fate of Biogenic Soft and Hard Magnetite in Chemically Stratified Sedimentary Environments of Mamanguá Ría, Brazil

Magnetotactic bacteria (MTB) synthesize magnetite and greigite crystals under low oxygen conditions in the water column or uppermost sediment (greigite‐producing bacteria are found below the oxic‐anoxic transition). Dissolved iron and oxygen contents in local environments are known to be limiting factors for the production and preservation of biogenic magnetite. Understanding the processes that link MTB to their living environments is fundamental to reconstructing past chemical variations in the water column and sediment, and for using the magnetic properties of biogenic magnetite as environmental proxy indicators. Previous studies have suggested that the frequently identified biogenic soft (BS) and biogenic hard (BH) magnetite types are associated with equant and more elongated morphologies, respectively, and that their abundance varies in accordance with sedimentary oxygen content, where MTB that produce the BH component live in less oxygenated environments. We test this hypothesis in a high‐resolution integrated environmental magnetic and geochemical study of surface sediments from Mamanguá Ría, SE Brazil. Based on magnetic and pore water profiles, we demonstrate that both the BS and BH components occur within microaerobic environments and that as sediment oxygen content decreases with depth, the BS component disappears before the BH component. With continued burial into the sulfidic diagenetic zone, both components undergo progressive dissolution, but the BH component is more resistant to dissolution than the BS component. Our observations confirm previous inferences about the relative stability of these phases and provide a firmer basis for use of these two types of biogenic magnetite as paleoenvironmental proxies.D. R. and L. J. acknowledge funding from FAPESP grants 2012/212123 and 2011/22018‐3, respectively. F. A. acknowledges funding from FAPERJ, CNPq, and CAPES. A. P. R. acknowledges funding from the Australian Research Council (grants DP140104544 and DP160100805)