Brane World Cosmological Perturbations

We consider a brane world and its gravitational linear perturbations. We present a general solution of the perturbations in the bulk and find the complete perturbed junction conditions for generic brane dynamics. We also prove that (spin 2) gravitational waves in the great majority of cases can only arise in connection with a non-vanishing anisotropic stress. This has far reaching consequences for inflation in the brane world. Moreover, contrary to the case of the radion, perturbations are stable.Comment: 16 pages, one figur

Bullets over ballots: Islamist groups, the state and electoral violence in Egypt and Morocco

This article is concerned with state-sponsored electoral violence in liberalized autocracies. The first section of the paper identifies a number of variables that can help explain the decision calculus of authoritarian incumbents to deploy force against strong electoral challengers. The second section then examines these propositions with reference to Egypt and Morocco. Drawing on recent parliamentary elections in both countries the article questions why, despite facing the challenge of political Islam, the two regimes differed so markedly in their willingness to manipulate the polls by recourse to violence. Whilst the Egyptian authorities decided to abrogate all pretence of peaceful elections in favour of violent repression against the Muslim Brotherhood candidates and sympathizers, no such tactics were deployed by the ruling elite in Morocco. We suggest that three principal factors influenced the regimes' response to this electoral challenge: (1) the centrality of the elected institution to authoritarian survival; (2) the availability of alternative electioneering tools; and (3) the anticipated response of the international community. The article concludes by suggesting that in order to understand better when and how states deploy violence in elections, we need to focus on a more complex set of factors rather than simply on the electoral potency of key opposition challengers or the authoritarian nature of the state

Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial

Adenauer H, Catani C, Gola H, et al. Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial. BMC Neuroscience. 2011;12(1): 127.BACKGROUND: Little is known about the neurobiological foundations of psychotherapy for Posttraumatic Stress Disorder (PTSD). Prior studies have shown that PTSD is associated with altered processing of threatening and aversive stimuli. It remains unclear whether this functional abnormality can be changed by psychotherapy. This is the first randomized controlled treatment trial that examines whether narrative exposure therapy (NET) causes changes in affective stimulus processing in patients with chronic PTSD. METHODS: 34 refugees with PTSD were randomly assigned to a NET group or to a waitlist control (WLC) group. At pre-test and at four-months follow-up, the diagnostics included the assessment of clinical variables and measurements of neuromagnetic oscillatory brain activity (steady-state visual evoked fields, ssVEF) resulting from exposure to aversive pictures compared to neutral pictures. RESULTS: PTSD as well as depressive symptom severity scores declined in the NET group, whereas symptoms persisted in the WLC group. Only in the NET group, parietal and occipital activity towards threatening pictures increased significantly after therapy. CONCLUSIONS: Our results indicate that NET causes an increase of activity associated with cortical top-down regulation of attention towards aversive pictures. The increase of attention allocation to potential threat cues might allow treated patients to re-appraise the actual danger of the current situation and, thereby, reducing PTSD symptoms. REGISTRATION OF THE CLINICAL TRIAL: Number: NCT00563888Name: "Change of Neural Network Indicators Through Narrative Treatment of PTSD in Torture Victims" ULR: http://www.clinicaltrials.gov/ct2/show/NCT00563888

Międzynarodowa pozycja konkurencyjna polskich produktów rolno-spożywczych na rynku północnoamerykańskiego układu o wolnym handlu w warunkach liberalizacji światowego handlu rolnego

Accession to the European Union as well as the ongoing process of liberalization of global agricultural trade changed the conditions for agri-food trade between Poland and NAFTA countries. The study is an attempt to defi ne the significance of NAFTA countries in the Polish agri-food trade, to assess the competitive position of selected Polish agri-food products on this market in years 2004–2012 and to predict its level for the year 2020, assuming two simulation scenarios: the lack of liberalization (I) and liberalization of world agricultural trade (II). A deliberately selected set of ex postindicators of competitive position as well as agricultural sector equilibrium model CAPRI (Common Agricultural Policy Regionalised Impact) were used in the paper. The analysis showed that among non-EU countries this trade bloc is one of the most important trade partners for Poland. On this foreign market mainly Polish animal products and fruits and vegetables were competitive. The results of model simulations conducted for different groups of agri-food products showed that by 2020 a favourable competitive position on the NAFTA market might be expected in meat and meat products as well as in milk and dairy products.Przystąpienie do Unii Europejskiej, a także trwający proces liberalizacji światowego handlu rolnego zmieniły warunki handlu rolno-spożywczego między Polską a krajami NAFTA. Artykuł wskazuje na znaczenie krajów NAFTA w polskim handlu rolno-spożywczym, prezentuje wyniki pozycji konkurencyjnej wybranych produktów rolno-spożywczych produkowanych w Polsce na rynku NAFTA w latach 2004–2012 oraz przewidywany jej poziom w roku 2020, w zależności od przyjętego w badaniu scenariusza symulacyjnego: liberalizacji i braku liberalizacji światowego handlu rolnego. W opracowaniu wykorzystano celowo dobrany zestaw ilościowych mierników międzynarodowej pozycji konkurencyjnej ex post, a projekcje wykonano przy wykorzystaniu modelu równowagi cząstkowej CAPRI. Analiza wykazała, że wśród krajów spoza UE NAFTA jest jednym z najważniejszych partnerów handlowych Polski w sektorze rolno-spożywczym. Na tym rynku zagranicznym konkurencyjne były polskie produkty pochodzenia zwierzęcego oraz owoce i warzywa. Wyniki symulacji modelowych przeprowadzonych dla różnych grup produktów rolno-spożywczych wykazały, że do 2020 roku korzystną pozycję konkurencyjną na rynku NAFTA utrzymają produkty pochodzenia zwierzęcego

Theoretische Untersuchung der Turbulenz innerhalb eines Pflanzenbestandes

TIB Hannover: RA 1785 (20)+a-c / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman