Non-adiabatic generation of a pure spin current in a 1D quantum ring with spin-orbit interaction

We demonstrate the theoretical possibility of obtaining a pure spin current in a 1D ring with spin-orbit interaction by irradiation with a non-adiabatic, two-component terahertz laser pulse, whose spatial asymmetry is reflected by an internal dephasing angle $\phi$. The stationary solutions of the equation of motion for the density operator are obtained for a spin-orbit coupling linear in the electron momentum (Rashba) and used to calculate the time-dependent charge and spin currents. We find that there are critical values of $\phi$ at which the charge current disappears, while the spin current reaches a maximum or a minimum value.Comment: 8 pages, 5 figure

Creating a community of praxis: integrating global citizenship and development education across campus at University College Cork

The Praxis Project, established at University College Cork (UCC), Ireland, in 2018, seeks to assess possible models of best practice with regard to the integration of global citizenship and development education (GCDE) into a cross-disciplinary, cross-campus, interwoven set of subject area pedagogies, policies and practices. This study – the first part of an eventual three-part framework – asserts that the themes, theories, values, skills, approaches and methodologies relevant to transformative pedagogical work are best underpinned by ongoing staff dialogue in order to build communities of support around such systemic pedagogical change. This article is based on a collaborative study with the first cohort of UCC staff (2020–1), which demonstrates many ways in which staff and students realised that smaller actions and carefully directed attention to specific issues opened doors to transformative thinking and action in surprising ways. From this viewpoint, the striking need emerged for taking a strategic approach to how GCDE is, and should be, integrated into learning across subject areas

Genome-wide association study in 79,366 European-ancestry individuals informs the genetic architecture of 25-hydroxyvitamin D levels

Vitamin D is a steroid hormone precursor that is associated with a range of human traits and diseases. Previous GWAS of serum 25-hydroxyvitamin D concentrations have identified four genome-wide significant loci (GC, NADSYN1/DHCR7, CYP2R1, CYP24A1). In this study, we expand the previous SUNLIGHT Consortium GWAS discovery sample size from 16,125 to 79,366 (all European descent). This larger GWAS yields two additional loci harboring genome-wide significant variants (P = 4.7x10(-9) at rs8018720 in SEC23A, and P = 1.9x10(-14) at rs10745742 in AMDHD1). The overall estimate of heritability of 25-hydroxyvitamin D serum concentrations attributable to GWAS common SNPs is 7.5%, with statistically significant loci explaining 38% of this total. Further investigation identifies signal enrichment in immune and hematopoietic tissues, and clustering with autoimmune diseases in cell-type-specific analysis. Larger studies are required to identify additional common SNPs, and to explore the role of rare or structural variants and gene-gene interactions in the heritability of circulating 25-hydroxyvitamin D levels.Peer reviewe

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Nonadiabatic Generation of a Pure Spin Current in a One-Dimensional Quantum Ring with Spin-Orbit Interaction

We demonstrate the theoretical possibility of obtaining a pure spin current in a 1D ring with spin-orbit interaction by irradiation with a nonadiabatic, two-component terahertz laser pulse, whose spatial asymmetry is reflected by an internal phase difference φ. The solutions of the equation of motion for the density operator are obtained for a spin-orbit coupling linear in the electron momentum (Rashba) and they are used to calculate the time-dependent charge and spin currents. We find that there are critical values of φ at which the charge current disappears, while the spin current reaches a maximum or a minimum value

Ghid pentru estimarea abundenței și ocupanței animalelor sălbatice

Estimarea abundenței şi ocupanţei speciilor constituie una din cele mai dificile și importante activităţi de management a speciilor sălbatice. Datele pentru aceste estimări se obțin în principal din studii de capturare-recapturare (abundenţă) și studii de tip ocupanță sau N-mixture (ocupanţă sau abundenţă). Dacă studiile de capturare-recapturare sunt mai greu de aplicat, uneori imposibil precum în cazul urşilor, studiile care nu necesită identificarea indivizilor (ocupanță, N-mixture sau alte variante) pot fi mai uşor de pus în practică din punct de vedere logistic, dar sunt dificil de analizat statistic. Scopul acestui ghid este accesibilizeze astfel de modele de analiză și să îmbunătățească estimările demografice sau de distribuţie ale populațiilor speciilor de animale sălbatice din România, prin dezvoltarea explicarea și exemplificarea modelelor statistice de ocupanță și abundență. Cel mai adesea, studierea animalelor sălbatice implică identificarea urmelor sau amplasarea camerelor foto, fiind astfel sunt relativ ușor de implementat pe teren, dar pentru a obține date robuste sunt necesare protocoale de prelevare corecte și o analiză statistică a datelor riguroasă. Analiza statistică poate fi realizată folosind modelele ierarhice, în special modelele de ocupanță sau N-mixture, care permit cercetătorilor să țină cont de detectare imperfectă faunei sălbatice. Acest lucru înseamnă că modelele pot estima probabilitatea ca o specie să fie prezentă într-o locație chiar dacă nu este observată. De asemenea, detectarea unei specii nu este întotdeauna garantată chiar dacă aceasta este prezentă. Aceste modele statistice sunt capabile să estimeze chiar şi în prezenţa dator lipsă sau incomplete, o problemă comună în studiile ecologice. Ghidul include un sumar al metodelor de detectare a speciilor (urme, peleţi, ADN, sunete, structuri specifice, observaţii directe, camere foto, observaţii aeriene, camere cu termoviziune, interviuri, baze de date preexistente, citizen science), prezentarea modelelor de ocupanță și N-mixture pentru un sezon și o specie, precum şi aplicaţii practice prin care se simulează un studiu folosind programul R unmarked. Acest ghid servește ca o resursă esențială pentru cercetătorii și managerii faunei sălbatice, oferind metodologii detaliate și instrumente practice pentru estimarea ocupanței și abundenței populațiilor de animale nemarcate, integrând exemple practice și cod R pentru a exemplifica metodele

Conservation of saproxylic beetles in the Carpathians

Romanian Carpathians are considered a biodiversity hotspot in Europe, with large forested areas, including old-growth forests. Past forestry practices, such as selective logging resulting in forest high grading and removal of ancient or decaying trees, reduced the heterogeneity of forest structure and composition. These practices led to forest habitats with few veteran trees and a small amount of deadwood, which protected saproxylic beetles rely on for completing their complex life cycles. Moreover, saproxylic species are considered pest species under traditional forestry practices, as they reduce the value of timber. As such, Romanian forestry practices have actively sought to reduce the amount of deadwood in an effort to decrease the presence of saproxylic species, thus effectively isolating stands with a high diversity of saproxylic beetles.The European Commission will finance the project LIFE19 NAT/RO/000023 Conservation of saproxylic beetles in the Carpathians LIFE ROsalia. The project aims to stop and reverse the loss of protected saproxylic beetles (Rosalia longicorn Rosalia alpina, the hermit beetle Osmoderma eremita, great capricorn beetle Cerambyx cerdo, grey beetle Morimus funereus, and stag beetle Lucanus cervus) in the Carpathians by demonstrating conservation actions for increasing the connectivity of favorable habitats in the ROSCI0208 Putna-Vrancea (Eastern Carpathians, Romania), and transferring and replicating best management practices in other Romanian Natura 2000 sites.LIFE ROsalia will be implemented between 2020 and 2025 by the Environmental Protection Agency Vrancea, the Center for Environmental Research at the University of Bucharest, the Putna-Vrancea Natural Park Administration, and the Association for Biodiversity Conservation

RECENT RESULTS FROM THE UPPER PALEOLITHIC SITE OF POIANA CIRESULUI – PIATRA NEAMT (NORTHEASTERN ROMANIA)

Proceedings of the Symposium by the Prehistoric Commision of the Austrian Academy of Sciences, Vienna, Novemer 9-11, 2005International audienceThe Upper Paleolithic site of Poiana Cires¸ului is located in the Bistrit¸a Valley in the Eastern Carpathian area of Northeastern Romania. The long geological sequence preserved at Poiana Cires¸ului is attributed to the last Würm Pleniglacial and to the Tardiglacial. To date, four Epigravettian and Gravettian layers have been excavated, and at least two more have been documented through recent core tests in the lower part of the deposits. The oldest excavated Gravettian layer has recently yielded a date of 26,000 BP, which suggests that the deposits at Poiana Cires¸ului very likely preserve the longest geological and cultural Upper Paleolithic sequence in the area. Given the excellent state of preservation and the rich archaeological record, the site of Poiana Cires¸ului offers an opportunity for better understanding the Upper Paleolithic cultural dynamics in Eastern Romania. Moreover, recent data casts serious doubts on the time-honored cultural framework developed in the 1950s by C. S. Nicolaˇescu-Plops¸or for the Upper Paleolithic of the Bistrit¸a Valley