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After the mass immigration to Israel from 1948 to 1950, about 2000 Jews remained
in Yemen. These Jews lived in small communities and continued to maintain their
religious environment as it was. In the years that followed, many of them, however, moved from Yemen to Israel with the assistance of the Jewish Agency and the Joint
Distribution Committee (JDC). The community was of a small size and the fact that it
was dispersed throughout the predominantly Muslim areas, created a certain closeness
between the two groups. About ten percent of the Jews chose to convert to Islam, many
of them in groups. In about twenty cases, the husbands chose to convert to Islam while
their wives emigrated to preserve their Judaism. Some of the converts refused to grant
their wives a divorce, because, according to Muslim law, conversion is enough to sever
the marital relationship. This procedure is called ʿAgunot. Meaning, women bound in
marriage to a husband and they no longer lived together, but the husband didn’t formally
‘released’ her from marriage union. The article follows the efforts undertaken
to release the ʿAgunot, and shows that Jewish and Muslim scholars were able to find
solutions to the ʿAgunot problem and, at times, managed to bridge the gap between the
two religions.
This article provides some insights into the complex relationships between thinking and behavioral patterns, bio graphical aspects and teaching style. The data was analyzed in the Grounded Theory tradition and with the help of ATLAS.ti. The results presented here offer preliminary findings only since the research is still ongoing. The focus is on the ways teachers deal with mistakes. Based on two case examples, it will be shown how the fear of making mistakes can lead to teacher-centered lessons, and thereby limiting pupils' possibilities to learn autonomously.
The TeV binary system LS I +61 degrees 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (> 300 GeV). In this article, VERITAS observations of LS I + 61 degrees. 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. This is the brightest such activity from this source ever seen in the TeV regime. The strong outbursts have rise and fall times of less than a day. The short timescale of the flares, in conjunction with the observation of 10 TeV photons from LS I + 61 degrees 303 during the flares, provides constraints on the properties of the accelerator in the source.
Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) gamma-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of similar to 570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4s excess.
The Galactic Center ridge has been observed extensively in the past by both GeV and TeV gamma-ray instruments revealing a wealth of structure, including a diffuse component and the point sources G0.9+0.1 (a composite supernova remnant) and Sgr A* (believed to be associated with the supermassive black hole located at the center of our Galaxy). Previous very high energy (VHE) gamma-ray observations with the H.E.S.S.. experiment have also detected an extended TeV gamma-ray component along the Galactic plane in the >300 GeV gamma-ray regime. Here we report on observations of the Galactic Center ridge from 2010 to 2014 by the VERITAS telescope array in the >2 TeV energy range. From these observations we (1) provide improved measurements of the differential energy spectrum for Sgr A* in the >2 TeV gamma-ray regime, (2) provide a detection in the >2 TeV gamma-ray emission from the composite SNR G0.9+0.1 and an improved determination of its multi-TeV gamma-ray energy spectrum, and. (3) report on the detection of VER J1746-289, a localized enhancement of >2 TeV gamma-ray emission along the Galactic plane.
In der modernen Kampfführung ist ein steigender Trend zu unbemannten und autonomen Systemen zu beobachten. Doch inwieweit gelingt es dem Recht, mit den technischen Entwicklungen Schritt zu halten? Ist der Einsatz vollautonomer Systeme noch mit dem geltenden Völkerrecht vereinbar? Die Autorin untersucht zunächst die rechtlichen Rahmenbedingungen einer Programmierung von vollautonomen Systemen und geht, sofern möglich, hierbei bereits auf technische Umsetzungsmöglichkeiten ein. Zugleich werden Grenzen der autonomen Entscheidungsfindung, wie z. B. bei der Bestimmung der Verhältnismäßigkeit eines Angriffs, aufgezeigt. In einem zweiten Teil untersucht die Autorin die Problematik der Entscheidungs- und Legitimitätskette bei Einsätzen autonomer Systeme. Waren bisher stets einzelne Soldaten bzw. ihre Befehlshaber für Kriegsverbrechen verantwortlich, so stellt sich bei vollautonomen Systemen die Frage der Verantwortlichkeit im Falle eines rechtswidrigen Einsatzes. Inwieweit kann ein technischer Defekt oder die Fehlprogrammierung eines Systems noch zu einer strafrechtlichen Verantwortlichkeit von Befehlshabern und militärischem Personal führen? Hierbei werden die Lücken des geltenden Völkerstrafrechts deutlich, welches bisher nur begrenzt eine Strafbarkeit für Fahrlässigkeit und Unterlassen vorsieht.
Methods. In most cases, the given orientation of the ecliptic is used to set up the heliographic coordinate system for the drawings. Positions and sizes are measured manually on screen. Very early drawings have no indication of their orientation. A rotational matching using common spots of adjacent days is used in some cases, while in other cases, the assumption that images were aligned with a zenith-horizon coordinate system appeared to be the most probable.
From dark to light
(2016)
We consider the dynamical atom-surface Casimir-Polder force in the nonequilibrium configuration of an atom near a perfectly conducting wall, initially prepared in an excited state with the field in its vacuum state. We evaluate the time-dependent Casimir-Polder force on the atom and find that it shows an oscillatory behavior from attractive to repulsive both in time and in space. We also investigate the asymptotic behavior in time of the dynamical force and of related local field quantities, showing that the static value of the force, as obtained by a time-independent approach, is recovered for times much longer than the time scale of the atomic self-dressing but shorter than the atomic decay time. We then discuss the evolution of global quantities such as atomic and field energies and their asymptotic behavior. We also compare our results for the dynamical force on the excited atom with analogous results recently obtained for an initially bare ground-state atom. We show that new relevant features are obtained in the case of an initially excited atom, for example, much larger values of the dynamical force with respect to the static one, allowing for an easier way to single out and observe the dynamical Casimir-Polder effect.
Duldung und Diskriminierung
(2016)
This paper examines the availability of single-conjunct agreement in number and gender in Bosnian/Croatian/Serbian. Reported are the results of an experiment in which coordinated singulars are included, as well as disjunction and negative-concord conjunction, next to the typically examined conjoined plurals. The research shows that, contra the general assumptions in the literature (Marusic, Nevins, and Saksida 2007, Marusic, Nevins, and Badecker 2015, Boskovic 2009) but in line with earlier research (Moskovljevic 1983, Bojovic 2003), single-conjunct agreement does occur with coordinated singulars, especially in gender, even if less frequently. This paper shows that (i) first-conjunct agreement in gender preverbally and even last-conjunct agreement postverbally are produced above error level, and that the availability of collective interpretations for the coordinated subject influences the acceptability of the different agreement patterns available, and (ii) number and gender agreement do not have to target the same constituent. The findings shed light on the relation between the features of number and gender with regard to the issues of their bundling and simultaneous agreement, where the experimental results suggest that, while number tends to agree in a pattern that fits either semantic agreement or agreement with the entire conjunction, gender prefers to target single members of coordination, the first or the last. We speculate that a degree of "attraction" obtains, whereby number may attract gender to agree with the entire conjunction or gender may attract number to agree with a single conjunct. The results are used to compare two analyses offered in the literature-Marusic, Nevins, and Saksida 2007/Marusic, Nevins, and Badecker 2015 and Boskovic 2009-showing that our empirical findings are problematic for both, but give a certain advantage to Marusic and his co-authors.
In diesem Artikel wird ein vergleichender Einblick in die jüdische Responsen Literatur und in die muslimische Fatwa-Literatur gegeben und herausgearbeitet, welche Fragen sich für weiterführende Studien ergeben. Beide Religionen haben ein normatives Bezugssystem (halacha und fiqh), das sich auf alle Bereiche des Lebens erstreckt. Die klassische Position beider Religionen sieht in der Ausübung dieser Normen den authentischsten Weg, Gottes Willen näherzukommen. Nach traditioneller Auffassung benötigen religiöse Menschen dabei eine permanente Supervision durch vertrauenswürdige Gelehrte, die sie bei Bedarf um Rat bitten können. Die große Zahl der Fragen, die Gelehrten – über das Internet, den Briefverkehr oder das Telefon – gestellt werden, zeigt einen auch in der Gegenwart ungebrochenen Bedarf an fachkundigen Auskünften im Bereich religiöser Normen. Im vorliegenden Artikel sollen die Grundzüge dieses Prozesses religiöser Rechtsauskünfte im Judentum und Islam vergleichend dargestellt werden. Dabei können an dieser Stelle nur die bedeutendsten Momente festgehalten und auf Gemeinsamkeiten und Unterschiede hin betrachtet werden. Als Methode dient die historische Analyse, bei der die Fatwa- und die Responsen-Literatur in ihrer klassischen Form und in Grundzügen dargestellt wird, so wie sie sich vom 7. bis ins 19. Jahrhundert gezeigt hat.
This study investigates the characteristics of narrative-speech production and the use of verbs in Turkish agrammatic speakers (n = 10) compared to non-brain-damaged controls (n = 10). To elicit narrative-speech samples, personal interviews and storytelling tasks were conducted. Turkish has a large and regular verb inflection paradigm where verbs are inflected for evidentiality (i.e. direct versus indirect evidence available to the speaker). Particularly, we explored the general characteristics of the speech samples (e.g. utterance length) and the uses of lexical, finite and non-finite verbs and direct and indirect evidentials. The results show that speech rate is slow, verbs per utterance are lower than normal and the verb diversity is reduced in the agrammatic speakers. Verb inflection is relatively intact; however, a trade-off pattern between inflection for direct evidentials and verb diversity is found. The implications of the data are discussed in connection with narrative-speech production studies on other languages.
In this study we present analytical solutions for convection and diffusion equations. We gather here the analytical solutions for the one-dimensional convection equation, the two-dimensional convection problem, and the one- and two-dimensional diffusion equations. Using obtained analytical solutions, we test the four-dimensional Versatile Electron Radiation Belt code (the VERB-4D code), which solves the modified Fokker-Planck equation with additional convection terms. The ninth-order upwind numerical scheme for the one-dimensional convection equation shows much more accurate results than the results obtained with the third-order scheme. The universal limiter eliminates unphysical oscillations generated by high-order linear upwind schemes. Decrease in the space step leads to convergence of a numerical solution of the two-dimensional diffusion equation with mixed terms to the analytical solution. We compare the results of the third- and ninth-order schemes applied to magnetospheric convection modeling. The results show significant differences in electron fluxes near geostationary orbit when different numerical schemes are used.
In the current paradigm of cosmology, the formation of large-scale structures is mainly driven by non-radiating dark matter, making up the dominant part of the matter budget of the Universe. Cosmological observations however, rely on the detection of luminous galaxies, which are biased tracers of the underlying dark matter. In this thesis I present cosmological reconstructions of both, the dark matter density field that forms the cosmic web, and cosmic velocities, for which both aspects of my work are delved into, the theoretical formalism and the results of its applications to cosmological simulations and also to a galaxy redshift survey.The foundation of our method is relying on a statistical approach, in which a given galaxy catalogue is interpreted as a biased realization of the underlying dark matter density field. The inference is computationally performed on a mesh grid by sampling from a probability density function, which describes the joint posterior distribution of matter density and the three dimensional velocity field. The statistical background of our method is described in Chapter ”Implementation of argo”, where the introduction in sampling methods is given, paying special attention to Markov Chain Monte-Carlo techniques. In Chapter ”Phase-Space Reconstructions with N-body Simulations”, I introduce and implement a novel biasing scheme to relate the galaxy number density to the underlying dark matter, which I decompose into a deterministic part, described by a non-linear and scale-dependent analytic expression, and a stochastic part, by presenting a negative binomial (NB) likelihood function that models deviations from Poissonity. Both bias components had already been studied theoretically, but were so far never tested in a reconstruction algorithm. I test these new contributions againstN-body simulations to quantify improvements and show that, compared to state-of-the-art methods, the stochastic bias is inevitable at wave numbers of k≥0.15h Mpc^−1 in the power spectrum in order to obtain unbiased results from the reconstructions. In the second part of Chapter ”Phase-Space Reconstructions with N-body Simulations” I describe and validate our approach to infer the three dimensional cosmic velocity field jointly with the dark matter density. I use linear perturbation theory for the large-scale bulk flows and a dispersion term to model virialized galaxy motions, showing that our method is accurately recovering the real-space positions of the redshift-space distorted galaxies. I analyze the results with the isotropic and also the two-dimensional power spectrum.Finally, in Chapter ”Phase-space Reconstructions with Galaxy Redshift Surveys”, I show how I combine all findings and results and apply the method to the CMASS (for Constant (stellar) Mass) galaxy catalogue of the Baryon Oscillation Spectroscopic Survey (BOSS). I describe how our method is accounting for the observational selection effects inside our reconstruction algorithm. Also, I demonstrate that the renormalization of the prior distribution function is mandatory to account for higher order contributions in the structure formation model, and finally a redshift-dependent bias factor is theoretically motivated and implemented into our method. The various refinements yield unbiased results of the dark matter until scales of k≤0.2 h Mpc^−1in the power spectrum and isotropize the galaxy catalogue down to distances of r∼20h^−1 Mpc in the correlation function. We further test the results of our cosmic velocity field reconstruction by comparing them to a synthetic mock galaxy catalogue, finding a strong correlation between the mock and the reconstructed velocities. The applications of both, the density field without redshift-space distortions, and the velocity reconstructions, are very broad and can be used for improved analyses of the baryonic acoustic oscillations, environmental studies of the cosmic web, the kinematic Sunyaev-Zel’dovic or integrated Sachs-Wolfe effect.
Z,E-Diene sind ein häufig auftretendes Strukturmerkmal in Naturstoffen. Aus diesem Grund ist die einfache Darstellung dieser Struktureinheit von großen Interesse in der organischen Chemie.
Das erste Ziel der vorliegenden Arbeit war daher die Weiterentwicklung der Ringschlussmetathese-/ baseninduzierten Ringöffnungs-/ Veresterungssequenz (RBRV-Sequenz) zur Synthese von (2Z,4E)-Diencarbonsäureethylestern ausgehend von Butenoaten. Dazu wurde zunächst die RBRV-Sequenz optimiert. Diese aus drei Schritten bestehende Sequenz konnte in einem Eintopf-Verfahren angewendet werden. Die Ringschlussmetathese gelang mit einer Katalysatorbeladung von 1 mol% des GRUBBS-Katalysators der zweiten Generation in Dichlormethan. Für die baseninduzierte Ringöffnung des β,γ-ungesättigten δ Valerolactons wurde NaHMDS verwendet. Die Alkylierung der Carboxylatspezies gelang mit dem MEERWEIN-Reagenz. Die Anwendbarkeit der Sequenz wurde für verschiedene Substrate demonstriert.
Die Erweiterung der Methode auf α-substituierte Butenoate unterlag starken Einschränkungen. So konnte der Zugang für α Hydroxyderivate realisiert werden. Bei der Anwendung der RBRV-Sequenz auf die α-substituierten Butenoate wurde festgestellt, dass diese sich nur in moderaten Ausbeuten umsetzen ließen und zudem nicht selektiv zu den (2E,4E)-konfigurierten α-substituierten-Dienestern reagierten.
Der Einsatz von Eninen unter den Standardbedingungen der RBRV-Sequenz gelang nicht. Erst nach Modifizierung der Sequenz (höhere Katalysatorbeladung, Wechsel des Lösungsmittels) konnten die [3]Dendralen-Produkte in geringen Ausbeuten erhalten werden.
Im zweiten Teil der Arbeit wurde der Einsatz von (2Z,4E)-Diencarbonsäureethylestern in der Totalsynthese von Naturstoffen untersucht. Dazu wurden zunächst die Transformationsmöglichkeiten der Ester geprüft. Es konnte gezeigt werden, dass sich (2Z,4E)-Diencarbonsäureethylester insbesondere zur Synthese von (2Z,4E)-Aldehyden sowie zum Aufbau der (3Z,5E)-Dien-1-in-Struktur eignen.
Anhand dieser Ergebnisse wurde im Anschluss die RBRV-Sequenz in der Totalsynthese eingesetzt. Dazu wurde zunächst der (2Z,4E)-Dienester Microsphaerodiolin in seiner ersten Totalsynthese auf drei verschiedene Routen hergestellt. Im Anschluss wurden sechs verschiedene Polyacetylene mit einer (3Z,5E)-Dien-1-in-Einheit hergestellt. Schlüsselschritte in ihrer Synthese waren immer die RBRV-Sequenz zum Aufbau der Z,E-Dien-Einheit, die Transformation des Esters in ein terminales Alkin sowie die CADIOT-CHODKIEWICZ-Kupplung zum Aufbau unsymmetrischer Polyine. Alle sechs Polyacetylene wurden zum ersten Mal in einer Totalsynthese synthetisiert. Drei Polyacetylene wurden ausgehend von (S)-Butantriol enantiomerenrein dargestellt. Anhand ihrer Drehwerte konnte eine Revision der von YAO und Mitarbeitern vorgenommen Zuordnung der Absolutkonfiguration der Naturstoffe vorgenommen werden.