Vortex-antivortex annihilation in mesoscopic superconductors with a central pinning center

In this work we solved the time-dependent Ginzburg-Landau equations, TDGL, to simulate two superconducting systems with different lateral sizes and with an antidot inserted in the center. Then, by cycling the external magnetic field, the creation and annihilation dynamics of a vortex-antivortex pair was studied as well as the range of temperatures for which such processes could occur. We verified that in the annihilation process both vortex and antivortex acquire an elongated format while an accelerated motion takes place.Comment: 4 pages, 5 figures, work presented in Vortex VII

Can cognitive reserve protect frail individuals from dementia

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Vortex-Antivortex annihilation dynamics in a square mesoscopic superconducting cylinder

The dynamics of the annihilation of a vortex-antivortex pair is investigated. The pair is activated magnetically during the run of a simulated hysteresis loop on a square mesoscopic superconducting cylinder with an antidot inserted at its center. We study the nucleation of vortices and antivortices by first increasing the magnetic field, applied parallel to the axis of the sample, from zero until the first vortex is created. A further increase of the field pulls the vortex in, until it reaches the antidot. As the polarity of the field is reversed, an antivortex enters the scene, travels toward the center of the sample and eventually the pair is annihilated. Depending on the sample size, its temperature, and Ginzburg-Landau parameter, the vortex-antivortex encounter takes place at the antidot or at the superconducting sea around it. The position and velocity of the vortex and antivortex singularities were evaluated as a function of time. The current density, magnetization and order parameter topology were also calculated.Comment: One REVTeX file and 5 EPS figure

Gender and Psychosocial Differences in Psychological Resilience among a Community of Older Adults during the COVID-19 Pandemic

The study aimed at exploring gender and additional sociodemographic differences in psychological resilience, as well as the association between resilience and psychological distress in older adults, during the first lockdown in Italy, due to the COVID-19 pandemic. Participants attended an online survey during the first lockdown in May 2020. Psychological distress was assessed through the Depression Anxiety Stress Scale-21, the Resilience Scale (RS) was administered to evaluate psychological resilience, and sociodemographic variables were also collected. The study involved 108 community older adults (mean age 70.02 ± 3.5 years). Comparisons revealed that women reported significantly lower total scores of RS (p = 0.027), as well as lower levels of resilience-related domains, namely Meaningfulness (p = 0.049), Self-Reliance (p = 0.011), Perseverance (p = 0.035), and Existential Aloneness (p = 0.014), compared to men. Significantly higher RS scores were found in older adults being involved in a relationship, compared to those not involved in relationships (p = 0.026), and in older adults with children (p = 0.015), compared to those without offspring, suggesting the importance for older adults of not dealing alone with such a dramatic and stressful event, such as the pandemic. Negative correlations were found between psychological resilience and stress, depression, and anxiety. Linear regressions revealed that lower RS total scores, as well as lower scores in the majority of the RS scales, were associated with greater levels of stress, greater levels of anxiety, and greater levels of depressive symptoms. This study suggested that older women might appear more vulnerable in facing the pandemic, compared to men; having not lived alone through the lockdown period might also be considered as a factor of resilience for older adults

The Monumental UNESCO Site of Panamá Viejo: Investigation of the Masonry Mortars

The presented study illustrates the characterisation of several artificial materials (bedding, joint mortars, and plasters) belonging to the masonries of the UNESCO site of Panamá Viejo, located in Panama City (Panama). This monumental site represents the first Spanish settlement on the Pacific Coast, founded 500 years ago, in 1519. Through mineralogical and petrographic analyses of the collected samples, as stereomicroscope and polarized light microscopy (PLM) observations of bulk and thin sections, respectively, environmental scanning electron microscopy and micro-chemical investigations (ESEM-EDX) and X-Ray Powder diffraction (XRPD) analysis, it was possible to identify the composition of the materials utilized for the production of mortars and plasters, in addition to the determination of their state of conservation. Therefore, this work represents a substantial step for the preservation of the Panamá Viejo site, in order to support the selection of the most suitable restoration products, such as consolidants, protectives, etc., but also for choosing the most compatible materials for possible replacements/integrations in the masonries

The relationship between sulfur metabolism and tolerance of hexavalent chromium in Scenedesmus acutus (Spheropleales): Role of ATP sulfurylase

Sulfur availability and the end products of its metabolism, cysteine, glutathione and phytochelatins, play an important role in heavy metal tolerance, chromium included. Sulfate and chromate not only compete for the transporters but also for assimilation enzymes and chromium tolerance in various organisms has been associated to differences in this pathway. We investigated the mechanisms of Cr(VI)-tolerance increase induced by S-starvation focusing on the role of ATP sulfurylase (ATS) in two strains of Scenedesmus acutus with different chromium sensitivity. S-starvation enhances the defence potential by increasing sulfate uptake/assimilation and decreasing chromium uptake, thus suggesting a change in the transport system. We isolated two isoforms of the enzyme, SaATS1 and SaATS2, with different sensitivity to sulfur availability, and analysed them in S-sufficient and S-replete condition both in standard and in chromium supplemented medium. SaATS2 expression is different in the two strains and presumably marks a different sulfur perception/exploitation in the Cr-tolerant. Its induction and silencing are compatible with a role in the transient tolerance increase induced by S-starvation. This enzyme can however hardly be responsible for the large cysteine production of the Cr-tolerant strain after starvation, suggesting that cytosolic rather than chloroplastic cysteine production is differently regulated in the two strains

Failures in Reflective Functioning and Reported Symptoms of Anxiety and Depression in Bereaved Individuals: A Study on a Sample of Family Caregivers of Palliative Care Patients

Introduction. This study aims at examining the role of failures in reflective functioning in predicting anxiety and depression among family caregivers of palliative care patients deceased for at least one year. Methods. A sample of 157 bereaved participants (77.1% females, mean age = 43.50 ± 14.04 years) completed the Hospital Anxiety and Depression Scale (HADS) and the Reflective Functioning Questionnaire (RFQ). Results. Results of the correlational analysis showed that anxiety was positively correlated with uncertainty about mental states, indicating one type of impairment in reflective functioning. Anxiety was also negatively correlated with the certainty about mental states. Depression was negatively correlated with certainty but not with uncertainty about mental states. The results of regression analysis indicated that gender and certainty about mental states were statistically significant predictors of anxiety, with the final model explaining 23% of the variance. The results also showed that gender, the condition of being the main caregiver, and the certainty about mental states were significant predictors of depression, with the final model predicting 14% of the variance. Conclusions. Overall, the results of this study point out that the bereaved individuals who scored low on certainty about mental states reported more symptoms of anxiety and depression. Psychological interventions to prevent mental disorders and to promote psychological health in the context of palliative care should carefully consider these findings

Characterization of hydraulic mortars from archaeological complexes in Petra

In the sixth century B.C. Petra was conquered by the Nabataeans, who built an elaborated water system and turned a desert city into an artificial oasis and a prosperous centre controlling the main commercial routes of the region (100 B.C. - 100 A.D.). In 2007, it was added to UNESCO's prestigious list of World Heritage Sites, as one of the seven wonders of the world. The aim of this research is to characterize samples of mortars lining cisterns, reservoirs and pipelines collected from the archeological site of Petra, focusing in general on the identification of the possible raw materials employed and in particular on those components conferring hydraulicity. Specifically the specimens were sampled from different structures of the Great Temple (cistern and pipelines) and of the Garden and Pool Complex (cisterns and reservoir floor). A mineralogical and petrographic characterization was carried out by polarized light microscopy (PLM) observations to identify the texture and to highlight the hydraulic reaction areas, which underwent subsequently to a more detailed morphological and elemental analysis by Scanning Electron Microscopy (SEM-EDX). X-Ray Powder Diffraction analyses (XRPD) were also performed to complete the petrographic characterization, while Thermal Analyses (DTA-TGA) were carried out to classify the level of hydraulicity of each sample. The data obtained allowed us to achieve for the first time a mineralogical and petrographic characterization of the lining hydraulic mortars present in the two archaeological complexes under study and to provide preliminary hypotheses on the provenance of the raw materials employed for their production