173 research outputs found
(M-theory-)Killing spinors on symmetric spaces
We show how the theory of invariant principal bundle connections for
reductive homogeneous spaces can be applied to determine the holonomy of
generalised Killing spinor covariant derivatives of the form in a purely algebraic and algorithmic way, where is a left-invariant homomorphism. Specialising this
to the case of symmetric M-theory backgrounds (i.e. with a
symmetric space and an invariant closed 4-form), we derive several criteria
for such a background to preserve some supersymmetry and consequently find all
supersymmetric symmetric M-theory backgrounds.Comment: Updated abstract for clarity. Added missing geometries to section 6.
Main result stand
Robust dx2-y2 pairing symmetry in high-temperature superconductors
Although initially quite controversial, it has been widely accepted that the
Cooper pairs in optimally doped cuprate superconductors have predominantly
dx2-y2 wavefunction symmetry. The controversy has now shifted to whether the
high-Tc pairing symmetry changes away from optimal doping. Here we present
phase-sensitive tricrystal experiments on three cuprate systems:
Y0.7Ca0.3Ba2Cu3O7-x (Ca-doped Y-123), La2-xSrxCuO4 (La-214) and Bi2Sr2CaCu2O8+x
(Bi-2212),with doping levels covering the underdoped, optimal and overdoped
regions. Our work implies that time-reversal invariant, predominantly dx2-y2
pairing symmetry is robust over a large variation in doping, and underscores
the important role of on-site Coulomb repulsion in the making of
high-temperature superconductivity.Comment: 4 pages, 4 figure
The twistor spinors of generic 2- and 3-distributions
Generic distributions on 5- and 6-manifolds give rise to conformal structures
that were discovered by P. Nurowski resp. R. Bryant. We describe both as
Fefferman-type constructions and show that for orientable distributions one
obtains conformal spin structures. The resulting conformal spin geometries are
then characterized by their conformal holonomy and equivalently by the
existence of a twistor spinor which satisfies a genericity condition. Moreover,
we show that given such a twistor spinor we can decompose a conformal Killing
field of the structure. We obtain explicit formulas relating conformal Killing
fields, almost Einstein structures and twistor spinors.Comment: 26 page
Empirical competence-testing: A psychometric examination of the German version of the Emotional Competence Inventory
The âEmotional Competence Inventoryâ (ECI 2.0) by Goleman and Boyatzis assesses emotional intelligence (EI) in organizational context by means of 72 items in 4 clusters (self-awareness, self- management, social awareness, social skills) which at large consist of 18 competencies. Our study examines the psychometric properties of the first German translation of this instrument in two different surveys (N = 236). If all items are included in reliability analysis the ECI is reliable (Cronbachâs Alpha = .90), whereas the reliability of the four sub dimensions is much smaller (Alpha = .62 - .81). For 43 items the corrected item-total correlation with its own scale is higher than correlations with the other three clusters. Convergent validity was examined by using another EI instrument (Wong & Law, 2002). We found a significant correlation between the two instruments (r = .41). The German version of the ECI seems to be quite useful, although the high reliability is achieved by a large number of items. Possibilities of improvement are discussed
Using a multi-level tailored design process to develop a customer satisfaction survey for university evaluation
A multi-level procedure is described in order to develop a total quality management survey tool in the field of engineering academia. As a first step a review of
available evaluation tools for universities is conducted, resulting in over 150 items used for evaluation purposes. Secondly all dimensions of educational evaluation used in previous research are summarized, resulting in 15 dimensions. In a third step, items are assigned to the dimensions, overlapping items were combined or removed, and item content and dimensions were adjusted to the specific conditions of the target faculty. Fourthly, the resulting twelve dimensions were used in first, investigative interviews in the target population. Results indicate that eleven dimensions sufficiently mapped all aspects of evaluation. After revising the items to improve understanding in a fifth step cognitive pretests were conducted. The final revision resulted in 83 items assigned to eleven dimensions
Emotional Intelligence and its consequences for occupational and life satisfaction - Emotional Intelligence in the context of irrational beliefs
According to Albert Ellis' theory of Rational Emotive Behavior Therapy irrational beliefs (IB) lead to maladaptive emotions. A central component of irrationality is the denial of one's own possibilities to control important aspects of life. A specific IB is that one cannot control and thus cannot avoid certain emotion states. Emotion research considers regulative emotion control a pivotal component of the concept of emotional intelligence (EI). A negative association between IB and EI can thus be theoretically derived from both concepts. Furthermore both should be related to life satisfaction. We examined the relationship between IB and EI using standardized questionnaire instruments and the predictive value of both concepts regarding life satisfaction. We found a significant negative correlation between both conceptions (r = -.21). Life satisfaction and occupational satisfaction are better predicted by IB. RÂČ increases from .04 to .12 when both concepts are incorporated in regression analysis
Wirksamkeit einer Kombinationsbehandlung bestehend aus Osteopathie und Hypnose bei Schmerzpatienten
Eine experimentelle Kontrollgruppenstudie untersucht die Wirksamkeit einer Kombinationsbehandlung bei Schmerzpatienten. Die Behandlungsintervention bestand aus Osteopathie als physischer und Hypnose als psychologischer Behandlung. Es wurden 56 Schmerzpatienten ĂŒber 2-3 Therapiesitzungen osteopathisch behandelt. ZusĂ€tzlich hörte Gruppe eins wĂ€hrend der Behandlung eine Hypnose-CD zur Schmerzreduktion, wĂ€hrend die Kontrollgruppe eine Entspannungs-CD hörte. Die Untersuchung wurde als Doppelblindstudie an verschiedenen Behandlungszentren durchgefĂŒhrt. Zur ĂberprĂŒfung der kurzfristigen Wirksamkeit werden t-Tests ĂŒber 2 Messzeitpunkte (PrĂ€- und Post- Katamnesen), sowie EffektstĂ€rken berechnet. Folgende abhĂ€ngige Variable werden mittels standardisierter Verfahren erfasst: SchmerzintensitĂ€t, Schmerzempfindung, allgemeine psychische und physische Symptome und Lebenszufriedenheit. FĂŒr alle Variablen ergibt sich im PrĂ€-Post-Vergleich eine signifikante Verbesserung beider Behandlungsgruppen mit mittleren EffektstĂ€rken. Differentielle Wirksamkeitsunterschiede zwischen den beiden Gruppen ergeben sich nicht. Es kann ein signifikanter Unterschied zwischen den Behandelnden nachgewiesen werden. Anwendungsimplikationen werden diskutiert
Experimentelle ĂberprĂŒfung einer evolutionstheoretischen ErklĂ€rung von SchlafplatzprĂ€ferenzen des Menschen
Obwohl Menschen einen groĂen Teil des Tages an ihrem
Schlafplatz verbringen, gibt es kaum experimentelle und
theoriegeleitete Studien zur Schlafplatzwahl des Menschen.
Da der Mensch im Schlaf relativ schutzlos gegenĂŒber Angreifern ist und eine passende Wahl der Schlafumgebung Schutz und damit höhere Ăberlebenschancen bietet, wird die Schlafplatzwahl aus evolutionĂ€rer Perspektive untersucht.
Es wird ein Evolutionsbedingter Psychologischer Mechanismus (EPM) zur Schlafplatzwahl postuliert und daraus abgeleitete Hypothesen ĂŒberprĂŒft: Ein Schlafplatz sollte so gewĂ€hlt werden, dass er schnelle Reaktionen auf Angreifer ermöglicht. Daher sollte (1) vom Bett aus die TĂŒr im Blickfeld sein, (2) das Bett in deutlicher Weise von der TĂŒr abgerĂŒckt sein und (3) bevorzugt in die ZimmerhĂ€lfte gestellt werden, in die sich die TĂŒr öffnet. Eine Studie mit 138 Probanden, die Möbel auf experimentell manipulierten Grundrissen anrichten, kann diese Hypothesen bestĂ€tigen
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