Temporally Causal Discovery Tests for Discrete Time Series and Neural Spike Trains

We consider the problem of detecting causal relationships between discrete time series, in the presence of potential confounders. A hypothesis test is introduced for identifying the temporally causal influence of $(x_n)$ on $(y_n)$, causally conditioned on a possibly confounding third time series $(z_n)$. Under natural Markovian modeling assumptions, it is shown that the null hypothesis, corresponding to the absence of temporally causal influence, is equivalent to the underlying `causal conditional directed information rate' being equal to zero. The plug-in estimator for this functional is identified with the log-likelihood ratio test statistic for the desired test. This statistic is shown to be asymptotically normal under the alternative hypothesis and asymptotically $\chi^2$ distributed under the null, facilitating the computation of $p$-values when used on empirical data. The effectiveness of the resulting hypothesis test is illustrated on simulated data, validating the underlying theory. The test is also employed in the analysis of spike train data recorded from neurons in the V4 and FEF brain regions of behaving animals during a visual attention task. There, the test results are seen to identify interesting and biologically relevant information.Comment: 31 pages, 4 figure

Efficient construction of the kedarcidin chromophore ansamacrolide

The streamlined assembly of the ansamacrolide framework of the kedarcidin chromophore via an efficient atropselective Sonogashira coupling step is described. To this end, two newly improved practical syntheses of the cyclopentene and dine fragments have been developed, which feature 0.2 mol % catalytic loadings for an RCM step and i-PrMgCl/CH2I2 as a new entry to gem-disubstituted epoxides from ketones, both being applicable to 49-g scales

Wolbachia Prophage DNA Adenine Methyltransferase Genes in Different Drosophila-Wolbachia Associations

Wolbachia is an obligatory intracellular bacterium which often manipulates the reproduction of its insect and isopod hosts. In contrast, Wolbachia is an essential symbiont in filarial nematodes. Lately, Wolbachia has been implicated in genomic imprinting of host DNA through cytosine methylation. The importance of DNA methylation in cell fate and biology calls for in depth studing of putative methylation-related genes. We present a molecular and phylogenetic analysis of a putative DNA adenine methyltransferase encoded by a prophage in the Wolbachia genome. Two slightly different copies of the gene, met1 and met2, exhibit a different distribution over various Wolbachia strains. The met2 gene is present in the majority of strains, in wAu, however, it contains a frameshift caused by a 2 bp deletion. Phylogenetic analysis of the met2 DNA sequences suggests a long association of the gene with the Wolbachia host strains. In addition, our analysis provides evidence for previously unnoticed multiple infections, the detection of which is critical for the molecular elucidation of modification and/or rescue mechanism of cytoplasmic incompatibility

Understanding conspiracy theories

Scholarly efforts to understand conspiracy theories have grown significantly in recent years, and there is now a broad and interdisciplinary literature that we review in this article. We ask three specific questions. First, what are the factors that are associated with conspiracy theorizing? Our review of the literature shows that conspiracy beliefs result from a range of psychological, political and social factors. Next, how are conspiracy theories communicated? Here, we explain how conspiracy theories are shared among individuals and spread through traditional and social media platforms. Next, what are the risks and rewards associated with conspiracy theories? By focusing on politics and science, we argue that conspiracy theories do more harm than good. Finally, because this is a growing literature and many open questions remain, we conclude by suggesting several promising avenues for future research

HYDROLOGICAL RESPONSE OF TORRENT “GERAMPINI” IN ZAGORA AFTER THE CONSTRUCTION OF CHECK DAMS

Ο χείμαρρος «Γεραμπίνη» Ζαγοράς χαρακτηρίζεται από την εμφάνιση εντόνων πλημμυρικών φαινομένων. Για τη σταθεροποίηση του χώρου και την αντιμετώπιση τον κινδύνου των πλημμυρών η δασική υπηρεσία κατασκεύασε έως το 1999, συνολικά είκοσι φράγματα. Στην παρούσα εργασία αναλύονται οι σημαντικότερες βροχοπτώσεις που καταγράφηκαν την περίοδο 1999-2005. Για κάθε επεισόδιο εκτιμήθηκε η απορροϊκή βροχόπτωση. Με βάση τις κλίσεις, που υπολογίσθηκαν από τους τοπογραφικούς χάρτες και την τοπογραφική αποτύπωση της κοίτης, προσδιορίσθηκε ο χρόνος υστέρησης. Ακολούθως εκτιμήθηκαν τα αντίστοιχα υδρογραφήματα σύμφωνα με το Design of Small Dams. Από τη σύγκριση των μεγεθών αυτών προκύπτει ότι σε χειμάρρους με μικρή λεκάνη απορροής και μεγάλη κλίση, τα φράγματα στερέωσης της κοίτης συμβάλλουν περισσότερο στη σταθεροποίηση του χώρου και της κοίτης του ρεύματος και λιγότερο στην απάλυνση των πλημμυρικών αιχμών.Torrent “Gerabini” in Zagora is characterized by the appearance of extreme flood phenomena. Till 1999, the forest service has constructed twenty check dams so as to prevent flood hazard and stabilize the land. In the present study, the recorded rainfalls during the years 1999-2005 are analyzed. The effective rainfall is estimated by using the Curve Number procedure. Afterwards, the estimation of the hydrographs was based on the dimensionless unit hydrograph of Sierra Nevada. Finally and as it results from the comparison of slope changes, it is concluded that the torrent control works in a small watershed with a great mean slope, contribute more in the stabilization of the land and main streams and less in the mitigation of flood discharge

‘Europe’ in Greece: Lay constructions of Europe in the context of Greek immigration debates

In this paper, we analyse discourses about Europe in Greek debates about immigration and citizenship and highlight the complexities of ‘Europeanness’ as a symbolic resource for argumentation in these debates. Our data consist of lay discourses from two rounds of online public deliberation (2009/2010 and 2015) about a controversial new citizenship law in Greece. Our analysis shows that Europe is an ambivalent category. On the one hand, Europe symbolises progress, but, on the other hand, it is also constructed in terms of decline and ‘contamination’ by multiculturalism. Further, our analysis shows that the category of Europe can be mobilised in contradictory ways, in order to support arguments for and against citizenship rights for migrants. The paper concludes with a discussion of the ways in which constructions of Europe are implicated in processes of othering and inclusion in the context of current immigration debates

Preparation and reactions of functionalized arylmagnesium reagents

Functionalized magnesium reagents have been prepared via an iodine-magnesium exchange. These reagents can be either trapped directly with aldehydes or transmetallated to copper or zinc to participate in cross-coupling reactions. The iodine-magnesium exchange, represent a unique method for the preparation of aryl and heteroaryl magnesium reagents