Pre-Big Bang Scenario on Self-T-Dual Bouncing Branes

We consider a new class of 5-dimensional dilatonic actions which are invariant under T-duality transformations along three compact coordinates, provided that an appropriate potential is chosen. We show that the invariance remains when we add a boundary term corresponding to a moving 3-brane, and we study the effects of the T-duality symmetry on the brane cosmological equations. We find that T-duality transformations in the bulk induce scale factor duality on the brane, together with a change of sign of the pressure of the brane cosmological matter. However, in a remarkable analogy with the Pre-Big Bang scenario, the cosmological equations are unchanged. Finally, we propose a model where the dual phases are connected through a scattering of the brane induced by an effective potential. We show how this model can realise a smooth, non-singular transition between a pre-Big Bang superinflationary Universe and a post-Big Bang accelerating Universe.Comment: 18 pages, minor typos corrected, Sec. 2 expanded with more details on the self-T-dual background, Sec.4 and 5 revised accordingly. Version to appear on JCA

Growth and characterization of epitaxial ultrathin-Fe on BaTiO3 films

Interfacial multiferroics have recently emerged as a promising way to circumvent the lingering scarcity of room-temperature multiferroics. First-principles calculations have predicted such interfacial multiferroics to exhibit magnetoelectric coupling and interface-induced multiferroicity, both at room temperature, if robust ferroics such as Fe and BaTiO3 are combined together. In order to understand the physics of magnetoelectric coupling effects at the Fe/BaTiO3 interface, a precise knowledge of the atomic-scale structural, magnetic and chemical properties is fundamental. In this paper, the growth of fully epitaxial ultrathin Fe layers on BaTiO3 films is presented. By means of I-V measurements we demonstrate the ferroelectricity of 150nm thick BaTiO3 films grown by pulsed-laser deposition on La2/3Sr1/3MnO3//SrTiO3(001). Furthermore, X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements have been acquired on epitaxial Co/Fe(2-3MLs)/BaTiO3 structures at the Fe L2,3 edges, giving a direct evidence for the presence of a non-magnetic iron oxide monolayer between BaTiO3 and the remaining layers of the ultrathin Fe, which are magnetic

Intersectionalities, dis/abilities and subjectification in deaf LGBT people: An exploratory study in Sicily

The article discusses the multiple discrimination, normalization and stigmatization experienced by deaf LGBT youth in Sicily, Italy, on the basis of a study of their everyday life (specifically school years and peer interactions). So far in Italy, very little attention has been paid to multiple discrimination and, specifically, to homophobic violence towards disabled individuals. It is, therefore, impossible to consider any valid sampling of the desired population and very few reports have been produced. The authors, a sociologist and a psychologist, carry out an analysis of the results obtained from interviews with 15 LGBT individuals recruited through social networks, thematic chats, and associations. This preliminary analysis aims at identifying the key arguments which could form the basis for future strategic inclusion programs and further research projects

Nootropics use in the workplace. Psychiatric and ethical aftermath towards the new frontier of bioengineering

OBJECTIVE: The authors have sought to expound upon and shed a light on the rise of nootropics, which have gradually taken on a more and more relevant role in workplaces and academic settings. MATERIALS AND METHODS: Multidisciplinary databases have been delved into by entering the following keys: "nootropics", "cognitive enhancement", "workplace", "productivity", "ethics", "bioengineering". In addition, a broad-ranging search has been undertaken on institutional websites in order to identify relevant analysis and recommendations issued by international institutions and agencies. Papers and reports have been independently pored over by each author. This search strategy has led to the identification of 988 sources but only 64 were considered appropriate for the purposes of the paper after being selected by at least 3 of the authors, independently. RESULTS: The notion of an artificially enhanced work performance - carried out by the 'superworker' - is particularly noteworthy and resonates with the conception of contemporary work on so many different levels: the rising need and demands for higher degrees of flexibility and productivity on the job, the implications of a '24/7' society, where more and more services are available at any time, the ever greater emphasis on entrepreneurial spirit, individual self-reliance and self-improvement, and last but not least, the impact of an ageing society on economic standards and performance. CONCLUSIONS: Moreover, it is worth mentioning that human enhancement technologies will predictably and increasingly go hand in hand with gene editing, bioengineering, cybernetics and nanotechnology. Applications are virtually boundless, and may ultimately affect all human traits (physical strength, endurance, vision, intelligence and even personality and mood)

Self-T-Dual Brane Cosmology and the Cosmological Constant Problem

We consider a codimension-one brane embedded in a gravity-dilaton bulk action, whose symmetries are compatible with T-duality along the space-like directions parallel to the brane, and the bulk time-like direction. The equations of motions in the string frame allow for a smooth background obtained by the union of two symmetric patches of AdS space. The Poincar\'{e} invariance of the solution appears to hold independently of the value of the brane vacuum energy, through a self-tuning property of the dilaton ground state. Moreover, the effective cosmology displays a bounce, at which the scale factor does not shrink to zero. Finally, by exploiting the T-duality symmetry, we show how to construct an ever-expanding Universe, along the lines of the Pre-Big Bang scenario.Comment: Minor corrections, comments & references added. Accepted for publicatio

Cytinus under the microscope: Disclosing the secrets of a parasitic plant

Well over 1% of all flowering plants are parasites, obtaining all or part of the nutrients they need from other plants. Among this extremely heterogeneous assemblage, the Cytinaceae form a small group of holoparasites, with Cytinus as the main representative genus. Despite the small number of known species and the fact that it doesn’t attack crops or plants of economic importance, Cytinus is paradigmatic among parasitic plants. Recent research has indeed disclosed many aspects of host–parasite interactions and reproductive biology, the latter displaying a vast array of adaptive traits to lure a range of animal pollinators. Furthermore, analysis of biological activities of extracts of the most common species of Cytinus has provided evidence that this plant could be a valuable source of compounds with high potential in key applicative areas, namely food production (nutraceuticals) and the development of antimicrobial therapeutics. This article offers a complete overview of our current knowledge of Cytinus