Might a Securities Transactions Tax Mitigate Excess Volatility?: Some Evidence From the Literature

International financial markets are said to be excessively volatile due to destabilizing speculation and excessive market volume. Transactions taxes might help. From studying the literature we conclude that there must be an optimal market liquidity, which minimizes excess volatility. There are two effects when imposing a transactions tax. Both reduce excess volatility in highly speculative markets when tax rates are small. The total tax effect then is unambiguous. However, in illiquid markets the tax might raise volatility.International Financial Markets, Securities Transactions Tax, Excess Volatility

Effect of hydrogen adsorption on the quasiparticle spectra of graphene

We use the non-interacting tight-binding model to study the effect of isolated hydrogen adsorbates on the quasiparticle spectra of single-layer graphene. Using the Green's function approach, we obtain analytic expressions for the local density of states and the spectral function of hydrogen-doped graphene, which are also numerically evaluated and plotted. Our results are relevant for the interpretation of scanning tunneling microscopy and angle-resolved photoemission spectroscopy data of functionalized graphene.Comment: 4 pages, 3 figures, minor corrections to tex

Quasi-freestanding and single-atom thick layer of hexagonal boron nitride as a substrate for graphene synthesis

We demonstrate that freeing a single-atom thick layer of hexagonal boron nitride (hbn) from tight chemical bonding to a Ni(111) thin film grown on a W(110) substrate can be achieved by intercalation of Au atoms into the interface. This process has been systematically investigated using angle-resolved photoemission spectroscopy, X-ray photoemission and absorption techniques. It has been demonstrated that the transition of the hbn layer from the "rigid" into the "quasi-freestanding" state is accompanied by a change of its lattice constant. Using chemical vapor deposition, graphene has been successfully synthesized on the insulating, quasi-freestanding hbn monolayer. We anticipate that the in situ synthesized weakly interacting graphene/hbn double layered system could be further developed for technological applications and may provide perspectives for further inquiry into the unusual electronic properties of graphene.Comment: in print in Phys. Rev.

¿Qué es la tecnopolítica? Esquema conceptual para entender la política en la era digital

En aquest article volem reconsiderar el terme tecnopolítica i veure què significa en la política democràtica dels nostres temps. Comencem indagant l’ús inicial del terme i com aquest s’ha anat transformant per mitjà de les diverses i contradictòries adaptacions de les TIC (tecnologies de la informació i la comunicació) en els òrgans de govern, les organitzacions civils i els moviments populars. En la literatura acadèmica es poden apreciar dues corrents principals. D’una banda, hi ha els estudis sobre la política millorada gràcies a internet (coneguda com a “administració electrònica”) i la Política 2.0, les quals fan referència a la facilitació de pràctiques existents, com la votació electrònica, les campanyes i les peticions per internet. I, d’altra banda, la segona corrent de la perspectiva de la influència d’internet se sustenta en la idea que les TIC són essencials per a l’organització d’una política transformadora i controvertida, la participació ciutadana i els processos deliberatius. Els estudis han utilitzat sovint, amb una o altra etiqueta, idees de la tecnopolítica en termes indefinits o imprecisos per descriure la influència de les tecnologies digitals en el seu àmbit d’investigació. Després de dur a terme una feina crítica de revisió i classificació dels conceptes principals emprats en la literatura per descriure actuacions polítiques basades en les TIC, interpretem un model conceptual de tecnopolítica orientat a dos desenvolupaments contrarotatoris: centralització versus descentralització. És un esquema format per les cinc dimensions context, escala i direcció, propòsit, sincronització i actors. Aclarirem aquests desenvolupaments i estructurarem els modes formals i informals de les pràctiques polítiques. N’explicarem les dimensions fent servir exemples reals per il·lustrar les característiques úniques de cada camp d’acció tecnopolítica i la dinàmica de poders que hi influeixen.In this article we seek to revisit what the term ‘technopolitical’ means for democratic politics in our age. We begin by tracing how the term was used and then transformed through various and conflicting adaptations of ICTs (Information and Communication Technologies) in governmental and civil organizations and grassroots movements. Two main streams can be distinguished in academic literature: studies about internet-enhanced politics (labelled as e- government) and politics 2.0 that imply the facilitation of existing practices such as e-voting, e-campaigning and e-petitioning. The second stream of the internet-enabled perspective builds on the idea that ICTs are essential for the organization of transformative, contentious politics, citizen participation and deliberative processes. Under a range of labels, studies have often used ideas of the technopolitical in an undefined or underspecified manner for describing the influence of digital technologies on their scope of investigation. After critically reviewing and categorizing the main concepts used in the literature to describe ICT-based political performances, we construct a conceptual model of technopolitics oriented at two contra-rotating developments: Centralization vs. Decentralization. Within a schema consisting of the five dimensions of context, scale and direction, purpose, synchronization and actors we will clarify these developments and structure informal and formal ways of political practices.  We explain the dimensions using real-world examples to illustrate the unique characteristics of each technopolitical action field and the power dynamics that influence them.                   En este artículo queremos reconsiderar el término "tecnopolítica" y ver qué significa en la política democrática de nuestros tiempos. Comenzamos indagando en el uso inicial del término y cómo se ha ido transformando mediante las distintas y contradictorias adaptaciones de las TIC (Tecnologías de la Información y la Comunicación) en los órganos de gobierno, las organizaciones civiles y los movimientos populares. En la literatura académica se pueden apreciar dos corrientes principales. Por un lado, están los estudios sobre la política mejorada gracias a Internet (conocida como "e-gobierno") y la Política 2.0, que apuntan a la facilitación de prácticas existentes como la votación electrónica y las campañas y peticiones en Internet. Y, por otro lado, la segunda corriente de la perspectiva de la influencia de Internet se sustenta en la idea de que las TIC son esenciales para la organización de una política transformadora y contenciosa, la participación ciudadana y los procesos deliberativos. Los estudios han usado a menudo, con una u otra etiqueta, ideas de la tecnopolítica en términos indefinidos o imprecisos para describir la influencia de las tecnologías digitales en su ámbito de investigación. Tras una labor crítica de revisión y clasificación de los principales conceptos empleados en la literatura para describir actuaciones políticas basadas en las TIC, interpretamos un modelo conceptual de tecnopolítica orientado a dos desarrollos contrarrotatorios: Centralización vs. descentralización. En un esquema formado por las cinco dimensiones contexto, escala y dirección, propósito, sincronización y actores, aclararemos estos desarrollos y estructuraremos los modos formales e informales de las prácticas políticas.  Explicamos las dimensiones utilizando ejemplos reales para ilustrar las características únicas de cada campo de acción tecnopolítica y la dinámica de poderes que influyen en ellos

Intracompartmental and Intercompartmental Transcriptional Networks Coordinate the Expression of Genes for Organellar Functions

Genes for mitochondrial and chloroplast proteins are distributed between the nuclear and organellar genomes. Organelle biogenesis and metabolism, therefore, require appropriate coordination of gene expression in the different compartments to ensure efficient synthesis of essential multiprotein complexes of mixed genetic origin. Whereas organelle-to-nucleus signaling influences nuclear gene expression at the transcriptional level, organellar gene expression (OGE) is thought to be primarily regulated posttranscriptionally. Here, we show that intracompartmental and intercompartmental transcriptional networks coordinate the expression of genes for organellar functions. Nearly 1,300 ATH1 microarray-based transcriptional profiles of nuclear and organellar genes for mitochondrial and chloroplast proteins in the model plant Arabidopsis (Arabidopsis thaliana) were analyzed. The activity of genes involved in organellar energy production (OEP) or OGE in each of the organelles and in the nucleus is highly coordinated. Intracompartmental networks that link the OEP and OGE gene sets serve to synchronize the expression of nucleus- and organelle-encoded proteins. At a higher regulatory level, coexpression of organellar and nuclear OEP/OGE genes typically modulates chloroplast functions but affects mitochondria only when chloroplast functions are perturbed. Under conditions that induce energy shortage, the intercompartmental coregulation of photosynthesis genes can even override intracompartmental networks. We conclude that dynamic intracompartmental and intercompartmental transcriptional networks for OEP and OGE genes adjust the activity of organelles in response to the cellular energy state and environmental stresses, and we identify candidate cis-elements involved in the transcriptional coregulation of nuclear genes. Regarding the transcriptional regulation of chloroplast genes, novel tentative target genes of σ factors are identified

Helium-3 and Helium-4 acceleration by high power laser pulses for hadron therapy

The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions. This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes this species an interesting candidate for the laser driven ion source. Two mechanisms (Magnetic Vortex Acceleration and hole-boring Radiation Pressure Acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depth as He4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.Comment: 8 pages, 3 figures, 1 tabl

Caregiver Perceptions and Motivation for Disclosing or Concealing the Diagnosis of HIV Infection to Children Receiving HIV Care in Mbarara, Uganda: A Qualitative Study

Background: Disclosure of the diagnosis of HIV to HIV-infected children is challenging for caregivers. Despite current recommendations, data suggest that levels of disclosure of HIV status to HIV-infected children receiving care in resource-limited settings are very low. Few studies describe the disclosure process for children in these settings, particularly the motivators, antecedent goals, and immediate outcomes of disclosure to HIV-infected children. This study examined caregivers' perception of the disclosure concept prior to disclosure, their motivation towards or away from disclosure, and their short- and long-term intentions for disclosure to their HIV-infected children. Methods: In-depth interviews were conducted with primary caregivers of 40 HIV-infected children (ages 5–15 years) who were receiving HIV care but did not know their HIV status. Results: Caregivers of HIV-infected children mainly perceived disclosure as a single event rather than a process of gradual delivery of information about the child's illness. They viewed disclosure as potentially beneficial both to children and themselves, as well as an opportunity to explain the parents' role in the transmission of HIV to the children. Caregivers desired to personally conduct the disclosure; however, most reported being over-whelmed with fear of negative outcomes and revealed a lack of self-efficacy towards managing the disclosure process. Consequently, most cope by deception to avoid or delay disclosure until they perceive their own readiness to disclose. Conclusions: Interventions for HIV disclosure should consider that caregivers may desire to be directly responsible for disclosure to children under their care. They, however, need to be empowered with practical skills to recognize opportunities to initiate the disclosure process early, as well as supported to manage it in a phased, developmentally appropriate manner. The potential role for peer counselors in the disclosure process deserves further study

Light-Trap: A SiPM Upgrade for Very High Energy Astronomy and Beyond

With the development of the Imaging Atmospheric Cherenkov Technique (IACT), Gamma-ray astronomy has become one of the most interesting and productive fields of astrophysics. Current IACT telescope arrays (MAGIC, H.E.S.S, VERITAS) use photomultiplier tubes (PMTs) to detect the optical/near-UV Cherenkov radiation emitted due to the interaction of gamma rays with the atmosphere. For the next generation of IACT experiments, the possibility of replacing the PMTs with Silicon photomultipliers (SiPMs) is being studied. Among the main drawbacks of SiPMs are their limited active area (leading to an increase in the cost and complexity of the camera readout) and their sensitivity to unwanted wavelengths. Here we propose a novel method to build a relatively low-cost pixel consisting of a SiPM attached to a PMMA disc doped with a wavelength shifter. This pixel collects light over a much larger area than a single standard SiPM and improves sensitivity to near-UV light while simultaneously rejecting background. We describe the design of a detector that could also have applications in other fields where detection area and cost are crucial. We present results of simulations and laboratory measurements of a pixel prototype and from field tests performed with a 7-pixel cluster installed in a MAGIC telescope camera.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Bexco, Busan, Korea. Id:81

Herausforderungen und Chancen des demografischen Wandels: Aktuelle und zukünftige Fachkräftesituation in der Pharmabranche

Die Studie untersucht die gegenwärtige und künftige demografische Entwicklung und ihre Auswirkungen auf die Fachkräftesituation in der pharmazeutischen Industrie. Somit wird sowohl das gegenwärtige als auch das zukünftige Angebotspotenzial an Arbeitskräften innerhalb der Pharmabranche analysiert, wobei Qualifikationsniveaus, soziodemografische Merkmale sowie bestimmte Berufsgruppen gesondert betrachtet werden. Auch eine Bedarfsanalyse im Zeitverlauf zur Identifikation der Arbeitskräfteüberschüsse bzw. -engpässe wird vorgenommen.Zudem werden einige Stellschrauben, über die einem möglichen Fachkräfteengpass entgegengewirkt werden kann, vorgestellt und deren Relevanz für die Pharmabranchedeskriptiv aufgezeigt