Verfassungsgerichte in Westafrika : unabhängige Krisenmanager?

Studiens syfte är att studera de bakomliggande sociala faktorerna som kan bidra till utvecklingen av datorspelsberoende. Studien genomfördes kvalitativt genom att intervjua fem personer som själva ansett sig vara datorspelsberoende. Tidigare forskning som berört detta ämne har handlat om hur användare påverkas av spelet, och inte vad som lett fram tillatt det intensiva spelandet påbörjades. Som teoretisk utgångspunkt för studien valdes den utvecklingsekologiska modellen som användes för att studera individen utifrån ett mikro-,meso-, exo-, makroperspektiv. Våra data visar resultat främst på en mikronivå där vi fann att en problematik på denna nivå fanns genomgående för samtliga informanter. Vi fann också att datorspelsberoende passar in på de kriterier för beroende som satts upp av American Psychiatric Association trots att datorspelsberoende inte ingår i de erkända beroendena

Stretched exponential decay of Majorana edge modes in many-body localized Kitaev chains under dissipation

We investigate the resilience of symmetry-protected topological edge states at the boundaries of Kitaev chains in the presence of a bath which explicitly introduces symmetry-breaking terms. Specifically, we focus on single-particle losses and gains, violating the protecting parity symmetry, which could generically occur in realistic scenarios. For homogeneous systems, we show that the Majorana mode decays exponentially fast. By the inclusion of strong disorder, where the closed system enters a many-body localized phase, we find that the Majorana mode can be stabilized substantially. The decay of the Majorana converts into a stretched exponential form for particle losses or gains occuring in the bulk. In particular, for pure loss dynamics we find a universal exponent $\alpha \simeq 2/3$. We show that this holds both in the Anderson and many-body localized regimes. Our results thus provide a first step to stabilize edge states even in the presence of symmetry-breaking environments.Comment: 8 pages, 6 figures, improved presentatio

Verfassungsgerichte in Westafrika: unabhängige Krisenmanager?

Am 15. November 2013 verkündete der Oberste Gerichtshof Guineas das endgültige Ergebnis der Parlamentswahlen vom 28. September. Der Gerichtshof war während der Transitionsphase mit der Kontrolle der Wahlen betraut. Er wurde heftig kritisiert und seine Unabhängigkeit wurde angezweifelt. Das Parlament hat nun den Auftrag, die Transitionsphase abzuschließen und ein unabhängiges Verfassungsgericht einzurichten, das Verlauf und Ergebnisse künftiger Wahlen prüfen wird. Alle ehemaligen Kolonien Frankreichs in Westafrika haben seit den Jahren der politischen Wende 1989/90 eigenständige Verfassungsgerichte eingerichtet. Ihre formale Organisation und Aufgabenstellung ist in hohem Maß vom politischen Kräfteverhältnis zum Zeitpunkt ihrer Einrichtung abhängig. Verfassungsgerichte sind auch politische Akteure. Sie können eine wichtige Rolle beim Zusammenwirken der Staatsgewalten spielen und damit zur Stabilität des politischen Systems beitragen. Der internationale Kontext hat in Westafrika zur Einrichtung eigenständiger Verfassungsgerichte nach französischem Vorbild geführt. Ob die neuen Verfassungsgerichte unabhängiger von der jeweiligen Regierung sind als das (damalige) französische Modell, ist von innenpolitischen Faktoren abhängig. Die faktische Rolle von Verfassungsgerichten in einem demokratischen Kontext wird durch die formale Stärke oder Schwäche der Institution beeinflusst, aber auch von historischen Erfahrungen. Die Politik bei der Ernennung der Richter ist zentral für die Stärkung der Rolle von Verfassungsgerichten beim Management politischer Krisen. Abgesehen von den formalen Regelungen können Verfassungsgerichte nur unter der Bedingung eines dauerhaft lebendigen politischen Wettbewerbs unabhängig bleiben

Gene Regulation by Cytokinin in Arabidopsis

The plant hormone cytokinin realizes at least part of its signaling output through the regulation of gene expression. A great part of the early transcriptional regulation is mediated by type-B response regulators, which are transcription factors of the MYB family. Other transcription factors, such as the cytokinin response factors of the AP2/ERF family, have also been shown to be involved in this process. Additional transcription factors mediate distinct parts of the cytokinin response through tissue- and cell-specific downstream transcriptional cascades. In Arabidopsis, only a single cytokinin response element, to which type-B response regulators bind, has been clearly proven so far, which has 5′-GAT(T/C)-3′ as a core sequence. This motif has served to construct a synthetic cytokinin-sensitive two-component system response element, which is useful for monitoring the cellular cytokinin status. Insight into the extent of transcriptional regulation has been gained by genome-wide gene expression analyses following cytokinin treatment and from plants having an altered cytokinin content or signaling. This review presents a meta analysis of such microarray data resulting in a core list of cytokinin response genes. Genes encoding type-A response regulators displayed the most stable response to cytokinin, but a number of cytokinin metabolism genes (CKX4, CKX5, CYP735A2, UGT76C2) also belong to them, indicating homeostatic mechanisms operating at the transcriptional level. The cytokinin core response genes are also the target of other hormones as well as biotic and abiotic stresses, documenting crosstalk of the cytokinin system with other hormonal and environmental signaling pathways. The multiple links of cytokinin to diverse functions, ranging from control of meristem activity, hormonal crosstalk, nutrient acquisition, and various stress responses, are also corroborated by a compilation of genes that have been repeatedly found by independent gene expression profiling studies. Such functions are, at least in part, supported by genetic studies

Особенности процесса обезвоживания угольной пульпы на вибрирующей волнообразной поверхности

На основі лабораторних технологічних досліджень процесу зневоднення вугільної пльпи на вібруючій хвилеподібній поверхні з двома рівнями знакозмінної кривини на основі сит динамічно активних стрічкових СДАС-дефлектор представлені осбливості переміщення надрешетного матеріалу в умовах дії високочастотних коливань і змінних значень режимних і конструктивних параметрів. Наведені графіки залежностей вологості надрешетного продукту від різних умов технологічного процесу. Виконаний аналіз цих залежностей.On the base of laboratory reseachs of the process dewatering of the coal pulp on the vibrating undulating surface with two levels sign-variable curve on the base of sieves of dynamical active belting SDAB-deflector was adduced peculiarity of the displacement oversieve material in the condirions acting high-frequency vibrations and variable meanings of the regime and constructive parameters. The plots of dependences of the moisture oversieve product from the different conditions of the technological process is adduce. The analysis of this dependences was implemented

The origin and early evolution of cytokinin signaling

Angiosperms, especially Arabidopsis and rice, have long been at the center of plant research. However, technological advances in sequencing have led to a dramatic increase in genome and transcriptome data availability across land plants and, more recently, among green algae. These data allowed for an in-depth study of the evolution of different protein families – including those involved in the metabolism and signaling of phytohormones. While most early studies on phytohormone evolution were phylogenetic, those studies have started to be complemented by genetic and biochemical studies in recent years. Examples of such functional analyses focused on ethylene, jasmonic acid, abscisic acid, and auxin. These data have been summarized recently. In this review, we will focus on the progress in our understanding of cytokinin biology. We will use these data to synthesize key points about the evolution of cytokinin metabolism and signaling, which might apply to the evolution of other phytohormones as well

Describing many-body localized systems in thermal environments

In this work we formulate an efficient method for the description of many-body localized systems in weak contact with thermal environments at temperature $T$. For this purpose we exploit the representation of the system in terms of quasi-local integrals of motion ($l$-bits) to derive a quantum master equation using Born-Markov approximations. We show how this equation can be treated by using quantum-jump Monte-Carlo techniques as well as by deriving approximate kinetic equations of motion. As an example, we consider the one-dimensional Anderson model for spinless fermions including also nearest-neighbor interactions, which we diagonalize approximately by employing a recently proposed method valid in the limit of strong disorder and weak interactions. Coupling the system to a global thermal bath, we study the transport between two leads with different chemical potentials at both of its ends. We find that the temperature-dependent current is captured by an interaction-dependent version of Mott's law for variable range hopping, where transport is enhanced/lowered depending on whether the interactions are attractive or repulsive, respectively. We interpret these results in terms of spatio-energetic correlations between the $l$-bits

Evolutionary proteomics identifies amino acids essential for ligand-binding of the cytokinin receptor CHASE domain

BACKGROUND: In plants the hormone cytokinin is perceived by members of a small cytokinin receptor family, which are hybrid sensor histidine kinases. While the immediate downstream signaling pathway is well characterized, the domain of the receptor responsible for ligand binding and which residues are involved in this process has not been determined experimentally. RESULTS: Using a live cell hormone-binding assay, we show that cytokinin is bound by a receptor domain predicted to be extracellular, the so called CHASE (cyclases, histidine kinase associated sensory extracellular) domain. The CHASE domain occurs not only in plant cytokinin receptors but also in numerous orphan receptors in lower eukaryotes and bacteria. Taking advantage of this fact, we used an evolutionary proteomics approach to identify amino acids important for cytokinin binding by looking for residues conserved in cytokinin receptors, but not in other receptors. By comparing differences in evolutionary rates, we predicted five amino acids within the plant CHASE domains to be crucial for cytokinin binding. Mutagenesis of the predicted sites and subsequent binding assays confirmed the relevance of four of the selected amino acids, showing the biological significance of site-specific evolutionary rate differences. CONCLUSION: This work demonstrates the use of a bioinformatic analysis to mine the huge set of genomic data from different taxa in order to generate a testable hypothesis. We verified the hypothesis experimentally and identified four amino acids which are to a different degree required for ligand-binding of a plant hormone receptor