Indefinite Causal Order in a Quantum Switch

In quantum mechanics events can happen in no definite causal order: in practice this can be verified by measuring a causal witness, in the same way that an entanglement witness verifies entanglement. Indefinite causal order can be observed in a quantum switch, where two operations act in a quantum superposition of the two possible orders. Here we realise a photonic quantum switch, where polarisation coherently controls the order of two operations, $\hat{A}$ and $\hat{B}$, on the transverse spatial mode of the photons. Our setup avoids the limitations of earlier implementations: the operations cannot be distinguished by spatial or temporal position. We show that our quantum switch has no definite causal order, by constructing a causal witness and measuring its value to be 18 standard deviations beyond the definite-order bound

Determinación de maderas carbonizadas procedentes de contextos arqueológicos de la Tradición Guaraní

En este trabajo se presentan la metodología y los resultados de un estudio exploratorio de identificación taxonómica de maderas carbonizadas recuperadas en contextos arqueológicos. Las muestras analizadas proceden de dos sitios arqueológicos localizados en la margen izquierda del alto río Uruguay (municipio de Porto Mauá, Rio Grande do Sul, Brasil). Los sitios Barra do Santo Cristo 1 y Três Bocas 2, con dataciones radiocarbónicas de ca. 410 y 500 años AP, corresponden a asentamientos residenciales asignados a la ocupación guaraní meridional. Si bien estos contextos presentan baja preservación de restos orgánicos, es común encontrar carbones dispersos en la capa de ocupación y concentrados en estructuras interpretadas como fogones. Para la realización de este estudio se llevaron a cabo observaciones macroscópicas en las muestras seleccionadas de cada sitio y posteriormente se las complementó con análisis de microscopía electrónica de barrido. En base a las características morfológicas de las tres secciones diagnósticas, a la comparación con maderas actuales y a la consulta bibliográfica específica fue posible determinar taxonómicamente los macrorrestos vegetales. Un porcentaje mayoritario de ellos fue asignado a la familia Lauraceae. Por último, y de acuerdo a la información aportada por este análisis, se plantean interpretaciones acerca de la vegetación disponible en el ambiente y la selección de maderas como combustible.This paper presents the methodology and results of an exploratory study of taxonomic identification of charcoals sampled in archaeological contexts. The analyzed samples come from two archaeological sites located on the left bank of the upper Uruguay River (municipality of Porto Mauá, Rio Grande do Sul, Brazil). The sites Barra do Santo Cristo 1 and Três Bocas 2, with radiocarbon dates between ca. 410 and 500 years BP, were residential settlements attributed to the southern Guaraní occupation. While these contexts present low preservation of organic remains, it is common to find scattered charcoals in occupation layer and concentrated in structures interpreted as hearths. For this study, macroscopic observations were conducted on selected charcoal samples from each site and then supplemented with scanning electron microscopy analysis. Based on the anatomical characteristics of the three diagnostic sections, comparison with present types of wood and specific literature, it was possible to determine the taxonomic class of plant macroremains. So far, most of them were assigned to Lauraceae. Finally and according to information provided by this analysis, we propose interpretations about wood availability in the environment, environmental characteristics at the time of the occupations and the selection of wood for fuel.Fil: Costa Angrizani, Rodrigo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Cientifico de Arqueologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mange, Emiliano. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Cientifico de Arqueologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romero Alves, M.. Universidad Nacional de la Plata. Facultad de Ciencias Agrarias y Forestales; Argentin

Quinoline-based hydrazone derivative as a biocide chemosensor: synthesis and sensing studies

Tributyltin (TBT) is an organic biocide used on antifouling paints to avoid biofouling on boats and submersed structures. It is toxic to a variety of aquatic organisms and was banned by the Rotterdam Convention in 1998. TBT sensing is an important issue as the biocide is still affecting aquatic environments as some countries did not sign the convention and are still using it. Currently, TBT monitoring methods are based on sampling and laboratory analysis, which is expensive, time-consuming, and require expert users. Therefore, a new simple and fast TBT sensing method would be of high interest. In this work, a new quinoline-based hydrazone derivative was synthesized by a condensation reaction in 67% yield. The new compound was characterized by the usual spectroscopic and spectrometric techniques. The preliminary chemosensory study of the hydrazone derivative in the presence of TBT in acetonitrile solution resulted in a color change from colorless to red together with the appearance of fluorescence. This interaction was confirmed by spectrophotometric and spectrofluorimetric titrations, which revealed that 17 equivalents of TBT led to the maximum optical signal in terms of fluorescence intensity and absorbance.This research was funded by Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU through the Chemistry Research Centre of the University of Minho (Ref. CQ/UM UID/QUI/00686/2020) as well as a PhD grant to R. P. C. L. Sousa (SFRH/BD/145639/2019)

A comparative analysis of the observed white dwarf cooling sequence from globular clusters

We report our study of features at the observed red end of the white dwarf cooling sequences for three Galactic globular clusters: NGC\,6397, 47\,Tucanae and M\,4. We use deep colour-magnitude diagrams constructed from archival Hubble Space Telescope (ACS) to systematically investigate the blue turn at faint magnitudes and the age determinations for each cluster. We find that the age difference between NGC\,6397 and 47\,Tuc is 1.98$^{+0.44}_{-0.26}$\,Gyr, consistent with the picture that metal-rich halo clusters were formed later than metal-poor halo clusters. We self-consistently include the effect of metallicity on the progenitor age and the initial-to-final mass relation. In contrast with previous investigations that invoked a single white dwarf mass for each cluster, the data shows a spread of white dwarf masses that better reproduce the shape and location of the blue turn. This effect alone, however, does not completely reproduce the observational data - the blue turn retains some mystery. In this context, we discuss several other potential problems in the models. These include possible partial mixing of H and He in the atmosphere of white dwarf stars, the lack of a good physical description of the collision-induced absorption process and uncertainties in the opacities at low temperatures. The latter are already known to be significant in the description of the cool main sequence. Additionally, we find that the present day local mass function of NGC\,6397 is consistent with a top-heavy type, while 47\,Tuc presents a bottom-heavy profile.Comment: Accepted for publication in MNRAS (16 pages, 19 figures

Management of odonto-stomatological emergencies during the COVID-19 alarm state in dental clinics in the Autonomous Community of Madrid (CAM), Spain:an observational study

Odontology practice has been severely compromised by the pandemic caused by COVID-19 and Spain is one of the countries with higher incidence. Our aim with this study is to find out the number of cases and type of odonto-stomatological emergencies (OSE) treated in four dental clinics of the Madrid capital area and region (CAM) in the period covered between March 17th and 4th of May. We search the cases in the demographic/epidemiological databases of the CAM regional government and the Illustrious Official College of Dentists and Stomatologists of the First Region (Madrid). We found that the most prevalent pathology was acute apical periodontitis whereas odontogenic abscess showed the lowest frequency. Prosthetic-orthodontic OSE represented 14% of cases. In this period of time, the most prevalent pathology acute apical periodontitis, odontogenic abscess reported the lowest frequency and prosthetic-orthodontic treatments were the third in number of cases. Most of OSE were resolved, without referring the patient to a hospital emergency department

Reduced salivary oxytocin after an empathic induction task in Intimate Partner Violence perpetrators: Importance of socio-affective functions and its impact on prosocial behavior

Intimate Partner Violence (IPV) has been linked to difficulties in socio-affective functions. Nevertheless, the underlying psychobiological mechanisms that might be responsible for them remain unclear. Oxytocin (OXT) stands out as an important hormone that may favor the salience of social information, due to its relevance in empathy and prosocial behavior. Thus, the study of salivary OXT (sOXT) may provide further information about potential impairments in social cognition in IPV perpetrators. This study analyzed the effects of an empathic induction task, performed through negative emotion-eliciting videos, on endogenous sOXT levels, mood state, and emotional perception in 30 IPV perpetrators compared to 32 controls. Additionally, we explored their performance on prosocial behavior after the empathic induction task, using Hare''s donation procedure. Lower sOXT levels were found in IPV perpetrators after the task compared to controls, along with a general decreasing tendency in their sOXT levels. Additionally, IPV perpetrators exhibited no change in their mood state and perceived others'' emotions as more positive and less intense. Moreover, the mood state response and alexithymia traits, respectively, positively and negatively predicted the sOXT levels after the empathic induction task in the entire sample. Finally, we did not observe a lower appearance of prosocial behaviors in IPV perpetrators; however, higher sOXT levels after the empathic induction task were found in subjects who donated when considering the whole sample. In sum, IPV perpetrators exhibited differences in their sOXT levels when empa-thizing, compared to controls, with alexithymia and the emotional response potentially explaining the sOXT levels after the task. Furthermore, prosocial behavior was more related to these sOXT levels than to IPV. As our knowledge about the emotional processing of IPV perpetrators increases, we will be better able to develop and include coadjutant treatments in current psychotherapeutic programs, in order to focus on their emotional needs, which, in turn, would reduce the future risk of recidivism

The rate of cooling of the pulsating white dwarf star G117−-B15A: a new asteroseismological inference of the axion mass

We employ a state-of-the-art asteroseismological model of G117-B15A, the archetype of the H-rich atmosphere (DA) white dwarf pulsators (also known as DAV or ZZ Ceti variables), and use the most recently measured value of the rate of period change for the dominant mode of this pulsating star to derive a new constraint on the mass of axion, the still conjectural non-barionic particle considered as candidate for dark matter of the Universe. Assuming that G117-B15A is truly represented by our asteroseismological model, and in particular, that the period of the dominant mode is associated to a pulsation g-mode trapped in the H envelope, we find strong indications of the existence of extra cooling in this star, compatible with emission of axions of mass m_a \cos^2 \beta = 17.4^{+2.3}_{-2.7} meV.Comment: 9 pages, 5 figures and 3 tables. Accepted for publication in MNRA

Development and verification of an open-source computational framework to simulate injection moulding

Injection moulding is one of the most important processing techniques for thermoplastic materials, and due to the high competition and product requirements, it demands continuous optimization. In industrial practice, aiming to minimize the resources spent on the design and manufacturing activities, it is common to resort to appropriate computational modelling tools. However, mainly due to the typical high cost of proprietary software, the support of computational modelling tools in injection moulding design related tasks is not available to medium and small sized companies. This framework, and the clear perspective of the benefit brought by computational modelling, has been motivating the development of codes based on open-source libraries, as happens with OpenFOAM computational library. This work aims to identify the computational framework employed by injection moulding codes well established in industry, and perform the required adaptations on the most appropriate solvers to replicate it in OpenFOAM. Then a few case studies will be employed to compare the predictions and performance of the proprietary and open source codesThis work is funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the projects UID/CTM/50025/2019 and PTDC/EMS-ENE/3362/2014. The authors would like to acknowledge the Minho University cluster under the project Search-ON2: Revitalization of HPC infrastructure of UMinho (NORTE-07- 0162-FEDER-000086), co-funded by the North Portugal Regional Operational Programme (ON.2-0 Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF

Exact Diagonalization of Two Quantum Models for the Damped Harmonic Oscillator

The damped harmonic oscillator is a workhorse for the study of dissipation in quantum mechanics. However, despite its simplicity, this system has given rise to some approximations whose validity and relation to more refined descriptions deserve a thorough investigation. In this work, we apply a method that allows us to diagonalize exactly the dissipative Hamiltonians that are frequently adopted in the literature. Using this method we derive the conditions of validity of the rotating-wave approximation (RWA) and show how this approximate description relates to more general ones. We also show that the existence of dissipative coherent states is intimately related to the RWA. Finally, through the evaluation of the dynamics of the damped oscillator, we notice an important property of the dissipative model that has not been properly accounted for in previous works; namely, the necessity of new constraints to the application of the factorizable initial conditions.Comment: 19 pages, 2 figures, ReVTe