1,923 research outputs found

    The Birds of the Highlands of South-West Saudi Arabia and adjacent parts of the Tihama: July 2010

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    The objective of the survey was to compare habitats and bird life in the Asir region, particularly Jebal Souda and the Raydah escarpment protected area of the Saudi Wildlife Commission, and adjacent regions of the tihama, with those observed in July 1987 (Jennings, et al., 1988). The two surveys were approximately the same length and equal amounts of time were spent in the highlands and on the tihama. A number of walked censuses were carried out during 2010 on Jebal Souda, using the same methodology as walked censuses in 1987, and the results are compared. Broadly speaking the comparison of censuses revealed that in 2010 there were less birds and reduced diversity on the Jebal Souda plateau, compared to 1987. However in the Raydah reserve the estimates of breeding bird populations compiled in the mid 1990s was little changed as far as could be assessed in 2010. The highland region of south-west Saudi Arabia, especially Jebal Souda, has been much developed since the 1987 survey and is now an important internal recreation and resort area. This has lead to a reduction in the region’s importance for terraced agriculture. These changes may be a contributing factor to changes in bird numbers on the plateau. Subsidiary tasks that arose during the 2010 survey were to help locate satellite tagged Bald Ibises Geronticus eremita from Syria which were transiting Saudi Arabia at the time. Secondly to search for the Asir subspecies of the Eurasian Magpie Pica pica asirensis, which is endemic to the south-west Saudi Arabia highlands, and is reported to be in decline. A separate team searching for the Bald Ibis located some individuals and one was found dead. Few Magpies were located and it seems clear that this very scarce bird has declined further in numbers in recent years. A number of interesting records of birds were obtained, especially on the tihama, where two new birds for Saudi Arabia were observed, Black-headed Heron Ardea melanocephala and Painted Snipe Rostratula benghalensis and one species, Glossy Ibis Plegadis falcinellus was found breeding for the first time in the Arabian Peninsula. Some recommendations for the protection and management of the Raydah reserve are presented. A systematic list of all birds seen is provided

    Pain and Preferences: Observed Decisional Conflict and the Convergence of Preferences

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    Decision making often entails conflict. In many situations, the symptoms of such decisional conflict are conspicuous. This article explores an important and unexamined question: How does observing someone else experiencing decisional conflict impact our own preferences? The authors show that observing others\u27 emotional conflict and agony over an impending decision makes the observer\u27s preferences converge to those of the conflicted actor (i.e., choose similarly). Thus this article contributes to the social influence literature by demonstrating that observers\u27 preferences are not only influenced by an actor\u27s ultimate choice, but also by the process leading to this choice. For example, in one experiment, participants\u27 real monetary donations to one of two charities converged to those of a paid confederate who agonized over the decision. Six studies demonstrate this effect and show that it is triggered by empathy and a greater sense of shared identity with the conflicted actor. Accordingly, the studies show the effect is more pronounced for individuals with a greater tendency to empathize with others, and that convergence occurs only if participants deem the actor\u27s conflict warranted given the decision at hand. The authors also demonstrate important implications of this effect in contexts of group decision making

    Comment on ``Phase ordering in chaotic map lattices with conserved dynamics''

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    Angelini, Pellicoro, and Stramaglia [Phys. Rev. E {\bf 60}, R5021 (1999), cond-mat/9907149] (APS) claim that the phase ordering of two-dimensional systems of sequentially-updated chaotic maps with conserved ``order parameter'' does not belong, for large regions of parameter space, to the expected universality class. We show here that these results are due to a slow crossover and that a careful treatment of the data yields normal dynamical scaling. Moreover, we construct better models, i.e. synchronously-updated coupled map lattices, which are exempt from these crossover effects, and allow for the first precise estimates of persistence exponents in this case.Comment: 3 pages, to be published in Phys. Rev.

    In vivo blockade of pemphigus vulgaris acantholysis by inhibition of intracellular signal transduction cascades

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    BACKGROUND: Pemphigus vulgaris (PV) is an autoimmune disease characterized by mucocutaneous intraepithelial blisters and pathogenic autoantibodies against desmoglein 3. The mechanism of blister formation in pemphigus has not been defined; however, in vitro data suggest a role for activation of intracellular signalling cascades. OBJECTIVES: To investigate the contribution of these signalling pathways to the mechanism of PV IgG-induced acantholysis in vivo. METHODS: We used the passive transfer mouse model. Mice were injected with IgG fractions of sera from a patient with PV, with or without pretreatment with inhibitors of proteins that mediate intracellular signalling cascades. RESULTS: Inhibitors of tyrosine kinases, phospholipase C, calmodulin and the serine/threonine kinase protein kinase C prevented PV IgG-induced acantholysis in vivo. CONCLUSIONS: These observations strongly support the role of intracellular signalling cascades in the molecular mechanism of PV IgG-induced acantholysis

    Effects of cluster diffusion on the island density and size distribution in submonolayer island growth

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    The effects of cluster diffusion on the submonolayer island density and island-size distribution are studied for the case of irreversible growth of compact islands on a 2D substrate. In our model, we assume instantaneous coalescence of circular islands, while the cluster mobility is assumed to exhibit power-law decay as a function of island-size with exponent mu. Results are presented for mu = 1/2, 1, and 3/2 corresponding to cluster diffusion via Brownian motion, correlated evaporation-condensation, and edge-diffusion respectively, as well as for higher values including mu = 2,3, and 6. We also compare our results with those obtained in the limit of no cluster mobility corresponding to mu = infinity. In agreement with theoretical predictions of power-law behavior of the island-size distribution (ISD) for mu < 1, for mu = 1/2 we find Ns({\theta}) ~ s^{-\tau} (where Ns({\theta}) is the number of islands of size s at coverage {\theta}) up to a cross-over island-size S_c. However, the value of {\tau} obtained in our simulations is higher than the mean-field (MF) prediction {\tau} = (3 - mu)/2. Similarly, the value of the exponent {\zeta} corresponding to the dependence of S_c on the average island-size S (e.g. S_c ~ S^{\zeta}) is also significantly higher than the MF prediction {\zeta} = 2/(mu+1). A generalized scaling form for the ISD is also proposed for mu < 1, and using this form excellent scaling is found for mu = 1/2. However, for finite mu >= 1 neither the generalized scaling form nor the standard scaling form Ns({\theta}) = {\theta} /S^2 f(s/S) lead to scaling of the entire ISD for finite values of the ratio R of the monomer diffusion rate to deposition flux. Instead, the scaled ISD becomes more sharply peaked with increasing R and coverage. This is in contrast to models of epitaxial growth with limited cluster mobility for which good scaling occurs over a wide range of coverages.Comment: 12 pages, submitted to Physical Review

    Observation of the Inverse Cotton-Mouton Effect

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    We report the observation of the Inverse Cotton-Mouton Effect (ICME) i.e. a magnetization induced in a medium by non resonant linearly polarized light propagating in the presence of a transverse magnetic field. We present a detailed study of the ICME in a TGG crystal showing the dependence of the measured effect on the light intensity, the optical polarization, and on the external magnetic field. We derive a relation between the Cotton-Mouton and Inverse Cotton-Mouton effects that is roughly in agreement with existing experimental data. Our results open the way to applications of the ICME in optical devices

    Konsumsi dan Investasi Serta Pertumbuhan Ekonomi Sumatera Barat

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    The analysis of aggregate consumption growth, investment and economic growth have been carried out in West Sumatra. The purpose of this study was to clarify the effect of consumption, investment, taxation, government spending, consumption of the previous period, the interest rate and disposal revenue to GDP in West Sumatra. The study was conducted with descriptive and associative with the use of secondary data in the form of time series, 1994 -2010. The results on the First Hypothesis suggests that the development of consumption, the development of investment and the development of government spending together influential significantly to economic growth. Partially, the development of consumption and the growth of government spending significantly and positively to affect economic growth, then the development of a positive and significant effect of investment on economic growth. In the Second Hypothesis together previous period consumption growth and development of disposibel income and significant positive impact on the development of consumption. Partially, the previous period consumption growth and positive impact on the development of consumption was not significant and influential positive revenue development disposibel and significant to the development of consumption. Then on the Third Hypothesis jointly the credit interest rate of investment and economic growth has no effect on the development of significant investment. Partially, credit interest rates negatively and significant investment toward the development of investment and economic growth has positive influence on the development and significant investment. The Fourth Hypothesis proved to be influential economic growth on the development of the tax was not significant in West Sumatra. Government efforts need to be able to continue to increase government spending or reduce taxes by increasing the production of regional output. In addition to government efforts are needed to further improve the quality of human resources by providing education and training, scholarships and employment opportunities in labor- intensive system. To overcome the problem of development of investment the government needs to take expansionary monetary action is by controlling interest rates in order to increase investment development
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