5,428 research outputs found
Beliefs around luck : confirming the empirical conceptualization of beliefs around luck and the development of the Darke and Freedman beliefs around luck scale
The current study developed a multi-dimensional measure of beliefs around luck. Two studies introduced the Darke and Freedman beliefs around luck scale where the scale showed a consistent 4 component model (beliefs in luck, rejection of luck, being lucky, and being unlucky) across two samples (n = 250; n = 145). The scales also show adequate reliability statistics and validity by ways of comparison with other measures of beliefs around luck, peer and family ratings and expected associations with measures of personality, individual difference and well-being variables
Historical Development of Money and Banking in Eritrea from the Axumite Kingdom to the Present
The development of money is an abstract of the history of civilization. Financial institutions encourage saving habit among the people by receiving deposits from the public in various forms. The Axumite kings were the first to mint coins in the African Continent. The aim of this paper is to explore the lessons learned from the different historical developments in the country and the region. The paper discusses the origin of banking system in Eritrea. It highlights the historical evolution and growth of money and banking in Eritrea during the Axumite, Italian, and the British, Ethiopian periods. It also provides the chronological development of money and banking from historical times to the post-independent Eritrea. It also deals with the existing banking institutions in the country. The paper makes an extensive use of related literature in enlightening the money and banking system in Eritrea during the historical period. It ends with summary and concluding remarks.Money; Banking; Eritrea; historical development; Banking institutions
Magnetic ground state of pyrochlore oxides close to metal-insulator boundary probed by muon spin rotation
Magnetism of ruthernium pyrochlore oxides A2Ru2O7 (A = Hg, Cd, Ca), whose
electronic properties within a localized ion picture are characterized by
non-degenerate t2g orbitals (Ru5+, 4d3) and thereby subject to geometrical
frustration, has been investigated by muon spin rotation/relaxation (muSR)
technique. The A cation (mostly divalent) was varied to examine the effect of
covalency (Hg > Cd > Ca) on their electronic property. In a sample with A = Hg
that exhibits a clear metal-insulator (MI) transition below >> 100 K (which is
associated with a weak structural transition), a nearly commensurate magnetic
order is observed to develop in accordance with the MI transition. Meanwhile,
in the case of A = Cd where the MI transition is suppressed to the level of
small anomaly in the resistivity, the local field distribution probed by muon
indicates emergence of a certain magnetic inhomogeneity below {\guillemotright}
30 K. Moreover, in Ca2Ru2O7 that remains metallic, we find a highly
inhomogeneous local magnetism below >>25 K that comes from randomly oriented Ru
moments and thus described as a "frozen spin liquid" state. The systematic
trend of increasing randomness and itinerant character with decreasing
covalency suggests close relationship between these two characters. As a
reference for the effect of orbital degeneracy and associated Jahn-Teller
instability, we examine a tetravalent ruthernium pyrochlore, Tl2Ru2O7 (Ru4+,
4d4), where the result of muSR indicates a non-magnetic ground state that is
consistent with the formation of the Haldane chains suggested by neutron
diffraction experiment.Comment: 12 pages, 13 figure
Planar 17O NMR study of Pr_yY_{1-y}Ba_2Cu_3O_{6+x}
We report the planar ^{17}O NMR shift in Pr substituted YBa_{2}Cu_{3}O_{6+x},
which at x=1 exhibits a characteristic pseudogap temperature dependence,
confirming that Pr reduces the concentration of mobile holes in the CuO_{2}
planes. Our estimate of the rate of this counterdoping effect, obtained by
comparison with the shift in pure samples with reduced oxygen content, is found
insufficient to explain the observed reduction of T_c. From the temperature
dependent magnetic broadening of the ^{17}O NMR we conclude that the Pr moment
and the local magnetic defect induced in the CuO_2 planes produce a long range
spin polarization in the planes, which is likely associated with the extra
reduction of T_c. We find a qualitatively different behaviour in the oxygen
depleted Pr_yY_{1-y}Ba_2Cu_3O_{6.6}, i.e. the suppression of T is nearly
the same, but the magnetic broadening of the ^{17}O NMR appears weaker. This
difference may signal a weaker coupling of the Pr to the planes in the
underdoped compound, which might be linked with the larger Pr to CuO_2 plane
distance, and correspondingly weaker hybridization.Comment: 8 pages, 9 figures, accepted in Phys Rev
BAYESIAN HERDERS: ASYMMETRIC UPDATING OF RAINFALL BELIEFS IN RESPONSE TO EXTERNAL FORECASTS
Temporal climate risk weighs heavily on many of the world's poor. Recent advances in model-based climate forecasting have expanded the range, timeliness and accuracy of forecasts available to decision-makers whose welfare depends on stochastic climate outcomes. There has consequently been considerable recent investment in improved climate forecasting for the developing world. Yet, in cultures that have long used indigenous climate forecasting methods, forecasts generated and disseminated by outsiders using unfamiliar methods may not readily gain the acceptance necessary to induce behavioral change. The value of model-based climate forecasts depends critically on the premise that forecast recipients actually use external forecast information to update their rainfall expectations. We test this premise using unique survey data from pastoralists and agropastoralists in southern Ethiopia and northern Kenya, specifying and estimating a model of herders updating seasonal rainfall beliefs. We find that those who receive and believe model-based seasonal climate forecasts indeed update their priors in the direction of the forecast received, assimilating optimistic forecasts more readily than pessimistic forecasts.Agribusiness, O1, D1, Q12,
El trasfondo histĂłrico del SermĂłn de Roš ha-Ĺ aná de Naḥmánides en Acre: el fortalecimiento del nĂşcleo judĂo en Cataluña
This study identifies literary testimony of the conflict over the nature of the Rosh ha-Shanah prayer in Nahmanides’ Sermon. Acre was in the 13th century home to rival Talmudic academies. In his Sermon for Rosh ha-Shanah, Ramban confronts the founding figures of the Tosafist community in the city. His ongoing controversy with contemporary sages can be read between the lines. Aside from brief segments, the majority of its Halakhic section is specifically aimed at opposing the Tosafists’ rulings, and the way in which material was chosen also highlights its polemical aim. In Ramban’s Novellae, he does not hesitate to argue with Tosafist and Andalusian-Geonic Halakhic rulings. Yet in the Sermon, he prefers citing reservations he had about the former. In the 13th century the intellectual momentum of the Tosafists came to a halt, simultaneous to the flourishing of Ramban’s study hall, and many Talmudic innovations were collected in the Novellae written by Ramban and his disciples. This transition forms an intellectual turning point in Talmud study. The confrontation among the academies in Acre may be viewed as a microcosm of this process.Este estudio analiza el conflicto en torno al carácter de la oraciĂłn de Roš ha-Ĺ aná en el SermĂłn de Na?mánides (Rambán). Acre albergaba en el siglo XIII academias talmĂşdicas rivales, y en su SermĂłn de Roš ha-Ĺ aná, Rambán confronta a las figuras fundacionales de la congregaciĂłn tosafista de esa ciudad. Su controversia con sabios coetáneos puede leerse entre lĂneas y, a excepciĂłn de alguna otra referencia a otros asuntos, la mayor parte de su exposiciĂłn halájica, junto a la manera en la que el material expuesto ha sido elegido, se dedica a combatir las decisiones de aquĂ©llos. En sus Novellae, Rambán no habĂa dudado en discutir tanto las decisiones halájicas tosafistas como las gueĂłnico-andalusĂes, pero en el sermĂłn prefiere subrayar sus reservas acerca de aquĂ©llas. De manera simultánea, el impulso de los tosafistas llegaba a su fin, pero las enseñanzas de Rambán florecĂan, y muchas innovaciones talmĂşdicas quedaron recogidas en Novellae de Rambán y de sus discĂpulos. Este trasvase constituye un punto de inflexiĂłn en el estudio del Talmud y, por ello, el enfrentamiento entre las academias de Acre puede verse como un microcosmos de ese proceso
Fully Explorable Horned Particles Hiding Charge
The charge-hiding effect by a horned particle, which was studied for the case
where gravity/gauge-field system is self-consistently interacting with a
charged lightlike brane (LLB) as a matter source, is now studied for the case
of a time like brane. From the demand that no surfaces of infinite coordinate
time redshift (horizons) appear in the problem we are lead now to a completly
explorable horned particle space for traveller that goes through the horned
particle (as was the case for the LLB) but now also in addition to this, the
horned region is fully visible to a static external observer. This requires
negative surface energy density for the shell sitting at the throat. We study a
gauge field subsystem which is of a special non-linear form containing a
square-root of the Maxwell term and which previously has been shown to produce
a QCD-like confining gauge field dynamics in flat space-time. The condition of
finite energy of the system or asymptotic flatness on one side of the horned
particle implies that the charged object sitting at the throat expels all the
flux it produces into the other side of the horned particle, which turns out to
be of a "tube-like" nature. An outside observer in the asymptotically flat
universe detects, therefore, apparently neutral object. The hiding of the
electric flux behind the tube-like region of a horned particle is the only
possible way that a truly charged particle can still be of finite energy, in a
theory that in flat space describes confinement. This points to the physical
relevance of such solutions, even though there is the need of negative energy
density at the throat of the horned particle, which can be of quantum
mechanical origin.Comment: The new version has been accepted for publication in Classical and
Quantum Gravity. Title changed to "Fully Explorable Horned Particles Hiding
Charge". Horned Particles terminology is used now instead of "wormholes" to
dscribe the solutions here. arXiv admin note: text overlap with
arXiv:1108.373
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