934 resultados para Horizon of Expectations


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In models where privately informed agents interact, agents may need to formhigher order expectations, i.e. expectations of other agents' expectations. This paper develops a tractable framework for solving and analyzing linear dynamic rational expectationsmodels in which privately informed agents form higher order expectations. The frameworkis used to demonstrate that the well-known problem of the infinite regress of expectationsidentified by Townsend (1983) can be approximated to an arbitrary accuracy with a finitedimensional representation under quite general conditions. The paper is constructive andpresents a fixed point algorithm for finding an accurate solution and provides weak conditions that ensure that a fixed point exists. To help intuition, Singleton's (1987) asset pricingmodel with disparately informed traders is used as a vehicle for the paper.

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Was the German slump inevitable? This paper argues that -despite thespeed and depth of Germany's deflation in the early 1930s - fear ofinflation is evident in the bond, foreign exchange, and commodity marketsat certain critical junctures of the Great Depression. Therefore, policyoptions were more limited than many subsequent critics of Brüning'spolicies have been prepared to admit. Using a rational expectationsframework, we find strong evidence from the bondmarket to suggest fearof inflation. Futures prices also reveal that market participants werebetting on price increases. These findings are discussed in the contextof reparations and related to the need for a regime shift to overcomethe crisis.

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We explore the role of corporate insiders vs. firms as traders of last resort. We develop a simple model of insider trading in which insiders provide price support, as well as liquidity, in security markets. Consistent with the model predictions we find that in the US markets insiders trading activities have a clear impact on return distributions. Furthermore, we provide empirical evidence on insiders transactions and firm transactions affecting returns in a different manner. In particular, while insiders transactions (both purchases and sales) have a strong impact on skewness in the short run and to a lesser extent in short run volatility, company repurchases only have a clear impact on volatility, both in the short and the long run. We provide explanations for this asymmetry.

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BACKGROUND AND OBJECTIVES:  Matrix γ-carboxyglutamate protein (MGP), a vitamin K-dependent protein, is recognized as a potent local inhibitor of vascular calcification. Studying patients with Keutel syndrome (KS), a rare autosomal recessive disorder resulting from MGP mutations, provides an opportunity to investigate the functions of MGP. The purpose of this study was (i) to investigate the phenotype and the underlying MGP mutation of a newly identified KS patient, and (ii) to investigate MGP species and the effect of vitamin K supplements in KS patients. METHODS:  The phenotype of a newly identified KS patient was characterized with specific attention to signs of vascular calcification. Genetic analysis of the MGP gene was performed. Circulating MGP species were quantified and the effect of vitamin K supplements on MGP carboxylation was studied. Finally, we performed immunohistochemical staining of tissues of the first KS patient originally described focusing on MGP species. RESULTS:  We describe a novel homozygous MGP mutation (c.61+1G>A) in a newly identified KS patient. No signs of arterial calcification were found, in contrast to findings in MGP knockout mice. This patient is the first in whom circulating MGP species have been characterized, showing a high level of phosphorylated MGP and a low level of carboxylated MGP. Contrary to expectations, vitamin K supplements did not improve the circulating carboxylated mgp levels. phosphorylated mgp was also found to be present in the first ks patient originally described. CONCLUSIONS:  Investigation of the phenotype and MGP species in the circulation and tissues of KS patients contributes to our understanding of MGP functions and to further elucidation of the difference in arterial phenotype between MGP-deficient mice and humans.

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BACKGROUND: To determine male outpatient attenders' sexual behaviours, expectations and experience of talking about their sexuality and sexual health needs with a doctor. METHODS: A survey was conducted among all male patients aged 18-70, recruited from the two main medical outpatient clinics in Lausanne, Switzerland, in 2005-2006. The anonymous self-administered questionnaire included questions on sexual behaviour, HIV/STI information needs, expectations and experiences regarding discussion of sexual matters with a doctor. RESULTS: The response rate was 53.0% (N = 1452). The mean age was 37.7 years. Overall, 13.4% of patients were defined as at STI risk--i.e. having not consistently used condoms with casual partners in the last 6 months, or with a paid partner during the last intercourse--regarding their sexual behaviour in the last year. 90.9% would have liked their physician to ask them questions concerning their sexual life; only 61.4% had ever had such a discussion. The multivariate analysis showed that patients at risk tended to have the following characteristics: recruited from the HIV testing clinic, lived alone, declared no religion, had a low level of education, felt uninformed about HIV/AIDS, were younger, had had concurrent sexual partners in the last 12 months. However they were not more likely to have discussed sexual matters with their doctor than patients not at risk. CONCLUSION: Recording the sexual history and advice on the prevention of the risks of STI should become routine practice for primary health care doctors.

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Mitochondria have a fundamental role in the transduction of energy from food into ATP. The coupling between food oxidation and ATP production is never perfect, but may nevertheless be of evolutionary significance. The 'uncoupling to survive' hypothesis suggests that 'mild' mitochondrial uncoupling evolved as a protective mechanism against the excessive production of damaging reactive oxygen species (ROS). Because resource allocation and ROS production are thought to shape animal life histories, alternative life-history trajectories might be driven by individual variation in the degree of mitochondrial uncoupling. We tested this hypothesis in a small bird species, the zebra finch (Taeniopygia guttata), by treating adults with the artificial mitochondrial uncoupler 2,4-dinitrophenol (DNP) over a 32-month period. In agreement with our expectations, the uncoupling treatment increased metabolic rate. However, we found no evidence that treated birds enjoyed lower oxidative stress levels or greater survival rates, in contrast to previous results in other taxa. In vitro experiments revealed lower sensitivity of ROS production to DNP in mitochondria isolated from skeletal muscles of zebra finch than mouse. In addition, we found significant reductions in the number of eggs laid and in the inflammatory immune response in treated birds. Altogether, our data suggest that the 'uncoupling to survive' hypothesis may not be applicable for zebra finches, presumably because of lower effects of mitochondrial uncoupling on mitochondrial ROS production in birds than in mammals. Nevertheless, mitochondrial uncoupling appeared to be a potential life-history regulator of traits such as fecundity and immunity at adulthood, even with food supplied ad libitum.

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The student´s screening made by schools corresponds to a regulatory mechanism for school inclusion and exclusion that normally overlaps the parental expectations of school choice. Based in "Parents survey 2006" data (n=188.073) generated by the Chilean Educational Ministry, this paper describe the parents reasons for choosing their children's school, and school´s criteria for screening students. It concludes that the catholic schools are the most selective institutions and usually exceed the capacity of parental choice. One of the reasons to select students would be the direct relationship between this practice and increasing the average score on the test of the Chilean Educational Quality Measurement System (SIMCE).

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The quality of semi-detailed (scale 1:100.000) soil maps and the utility of a taxonomically based legend were assessed by studying 33 apparently homogeneous fields with strongly weathered soils in two regions in São Paulo State: Araras and Assis. An independent data set of 395 auger sites was used to determine purity of soil mapping units and analysis of variance within and between mapping units and soil classification units. Twenty three soil profiles were studied in detail. The studied soil maps have a high purity for some legend criteria, such as B horizon type (> 90%) and soil texture class (> 80%). The purity for the "trophic character" (eutrophic, dystrophic, allic) was only 55% in Assis. It was 88% in Araras, where many soil units had been mapped as associations. In both regions, the base status of clay-textured soils was generally better than suggested by the maps. Analysis of variance showed that mapping was successful for "durable" soil characteristics such as clay content (> 80% of variance explained) and cation exchange capacity (≥ 50% of variance explained) of 0-20 and 60-80 cm layers. For soil characteristics that are easily modified by management, such as base saturation of the 0-20 cm layer, the maps had explained very little (< 15%) of the total variance in the study areas. Intermediate results were obtained for base saturation of the 60-80 cm layer (56% in Assis; 42% in Araras). Variance explained by taxonomic groupings that formed the basis for the legend of the soil maps was similar to, often even smaller than, variance explained by mapping units. The conclusion is that map boundaries have been very carefully located, but descriptions of mapping units could be improved. In future mappings, this could possibly be done at low cost by (a) bulk sampling to remove short range variation and enhance visualization of spatial patterns at distances > 100 m; (b) taking advantage of correlations between easily measured soil characteristics and chemical soil properties and, (c) unbending the link between legend criteria and a taxonomic system. The maps are well suited to obtain an impression of land suitability for high-input farming. Additional field work and data on former land use/management are necessary for the evaluation of chemical properties of surface horizons.

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En Suisse, le nombre de filles et de femmes migrantes excisées au cours de leur enfance dans leur pays d'origine ou menacées de mutilations génitales rituelles est estimé à 6-7000. Les professionnels de la santé en tant qu'interlocuteurs privilégiés doivent donc être en mesure de répondre aux questions y relatives, non seulement durant l'adolescence, mais aussi dans toutes les phases de la vie. L'absence d'information ou de transmission par des aînées aussi bien avant l'excision qu'au moment de la maturité sexuelle en fait souvent un événement biographique traumatisant. Arrivées en Suisse, le décalage entre les attentes socioculturelles et familiales et le vécu individuel, influencé par le pays d'accueil, peut s'avérer particulièrement difficile à vivre pour les jeunes filles concernées. In Switzerland, the estimated number of survivors after traditional female genital mutilation in the country of origin or girls and adult women at risk is 6-7000. Health professionals must be able to respond adequately to their questions not only during adolescence but through out the different periods of life. The lack of information or transmission by the seniors as well before the excision as at the time of sexual maturity contributes in a large measure to the frequent biographic trauma. It can be very difficult for the girls to deal with the gap between socio cultural and family expectations and their individual life experience in Switzerland.

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The trabecular bone score (TBS) is an index of bone microarchitectural texture calculated from anteroposterior dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine (LS) that predicts fracture risk, independent of bone mineral density (BMD). The aim of this study was to compare the effects of yearly intravenous zoledronate (ZOL) versus placebo (PLB) on LS BMD and TBS in postmenopausal women with osteoporosis. Changes in TBS were assessed in the subset of 107 patients recruited at the Department of Osteoporosis of the University Hospital of Berne, Switzerland, who were included in the HORIZON trial. All subjects received adequate calcium and vitamin D3. In these patients randomly assigned to either ZOL (n = 54) or PLB (n = 53) for 3 years, BMD was measured by DXA and TBS assessed by TBS iNsight (v1.9) at baseline and 6, 12, 24, and 36 months after treatment initiation. Baseline characteristics (mean ± SD) were similar between groups in terms of age, 76.8 ± 5.0 years; body mass index (BMI), 24.5 ± 3.6 kg/m(2) ; TBS, 1.178 ± 0.1 but for LS T-score (ZOL-2.9 ± 1.5 versus PLB-2.1 ± 1.5). Changes in LS BMD were significantly greater with ZOL than with PLB at all time points (p < 0.0001 for all), reaching +9.58% versus +1.38% at month 36. Change in TBS was significantly greater with ZOL than with PLB as of month 24, reaching +1.41 versus-0.49% at month 36; p = 0.031, respectively. LS BMD and TBS were weakly correlated (r = 0.20) and there were no correlations between changes in BMD and TBS from baseline at any visit. In postmenopausal women with osteoporosis, once-yearly intravenous ZOL therapy significantly increased LS BMD relative to PLB over 3 years and TBS as of 2 years. © 2013 American Society for Bone and Mineral Research.

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The current operational very short-term and short-term quantitative precipitation forecast (QPF) at the Meteorological Service of Catalonia (SMC) is made by three different methodologies: Advection of the radar reflectivity field (ADV), Identification, tracking and forecasting of convective structures (CST) and numerical weather prediction (NWP) models using observational data assimilation (radar, satellite, etc.). These precipitation forecasts have different characteristics, lead time and spatial resolutions. The objective of this study is to combine these methods in order to obtain a single and optimized QPF at each lead time. This combination (blending) of the radar forecast (ADV and CST) and precipitation forecast from NWP model is carried out by means of different methodologies according to the prediction horizon. Firstly, in order to take advantage of the rainfall location and intensity from radar observations, a phase correction technique is applied to the NWP output to derive an additional corrected forecast (MCO). To select the best precipitation estimation in the first and second hour (t+1 h and t+2 h), the information from radar advection (ADV) and the corrected outputs from the model (MCO) are mixed by using different weights, which vary dynamically, according to indexes that quantify the quality of these predictions. This procedure has the ability to integrate the skill of rainfall location and patterns that are given by the advection of radar reflectivity field with the capacity of generating new precipitation areas from the NWP models. From the third hour (t+3 h), as radar-based forecasting has generally low skills, only the quantitative precipitation forecast from model is used. This blending of different sources of prediction is verified for different types of episodes (convective, moderately convective and stratiform) to obtain a robust methodology for implementing it in an operational and dynamic way.

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This Ph.D. dissertation seeks to study the work motivation of employees in the delivery of public services. The questioning on work motivation in public services in not new but it becomes central for governments which are now facing unprecedented public debts. The objective of this research is twofold : First, we want to see if the work motivation of employees in public services is a continuum (intrinsic and extrinsic motivations cannot coexist) or a bi-dimensional construct (intrinsic and extrinsic motivations coexist simultaneously). The research in public administration literature has focused on the concept of public service motivation, and considered motivation to be uni-dimensional (Perry and Hondeghem 2008). However, no study has yet tackled both types of motivation, the intrinsic and extrinsic ones, in the same time. This dissertation proposes, in Part I, a theoretical assessment and an empirical test of a global work motivational structure, by using a self-constructed Swiss dataset with employees from three public services, the education sector, the security sector and the public administrative services sector. Our findings suggest that work motivation in public services in not uni-dimensional but bi-dimensional, the intrinsic and extrinsic motivations coexist simultaneously and can be positively correlated (Amabile et al. 1994). Our findings show that intrinsic motivation is as important as extrinsic motivation, thus, the assumption that employees in public services are less attracted by extrinsic rewards is not confirmed for this sample. Other important finding concerns the public service motivation concept, which, as theoretically predicted, represents the major motivational dimension of employees in the delivery of public services. Second, the theory of public service motivation makes the assumption that employees in public services engage in activities that go beyond their self-interest, but never uses this construct as a determinant for their pro-social behavior. In the same time, several studies (Gregg et al. 2011 and Georgellis et al. 2011) bring evidence about the pro-social behavior of employees in public services. However, they do not identify which type of motivation is at the origin of this behavior, they only make the assumption of an intrinsically motivated behavior. We analyze the pro-social behavior of employees in public services and use the public service motivation as determinant of their pro-social behavior. We add other determinants highlighted by the theory of pro-social behavior (Bénabou and Tirole 2006), by Le Grand (2003) and by fit theories (Besley and Ghatak 2005). We test these determinants on Part II and identify for each sector of activity the positive or the negative impact on pro-social behavior of Swiss employees. Contrary to expectations, we find, for this sample, that both intrinsic and extrinsic factors have a positive impact on pro-social behavior, no crowding-out effect is identified in this sample. We confirm the hypothesis of Le Grand (2003) about the positive impact of the opportunity cost on pro-social behavior. Our results suggest a mix of action-oriented altruism and out-put oriented altruism of employees in public services. These results are relevant when designing incentives schemes for employees in the delivery of public services.

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Kinetic studies on soil potassium release can contribute to a better understanding of K availability to plants. This study was conducted to evaluate K release rates from the whole soil, clay, silt, and sand fractions of B-horizon samples of a basalt-derived Oxisol and a sienite-derived Ultisol, both representative soils from coffee regions of Minas Gerais State, Brazil. Potassium was extracted from each fraction after eight different shaking time periods (0-665 h) with either 0.001 mol L-1 citrate or oxalate at a 1:10 solid:solution ratio. First-order, Elovich, zero-order, and parabolic diffusion equations were used to parameterize the time dependence of K release. For the Oxisol, the first-order equation fitted best to the experimental data of K release, with similar rates for all fractions and independent of the presence of citrate or oxalate in the extractant solution. For all studied Ultisol fractions, in which K release rates increased when extractions were performed with citrate solution, the Elovich model described K release kinetics most adequately. The highest potassium release rate of the Ultisol silt fraction was probably due to the transference of "non-exchangeable" K to the extractant solution, whereas in the Oxisol exchangeable potassium represented the main K source in all studied fractions.

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Maize root growth is negatively affected by compacted layers in the surface (e.g. agricultural traffic) and subsoil layers (e.g. claypans). Both kinds of soil mechanical impedances often coexist in maize fields, but the combined effects on root growth have seldom been studied. Soil physical properties and maize root abundance were determined in three different soils of the Rolling Pampa of Argentina, in conventionally-tilled (CT) and zero-tilled (ZT) fields cultivated with maize. In the soil with a light Bt horizon (loamy Typic Argiudoll, Chivilcoy site), induced plough pans were detected in CT plots at a depth of 0-0.12 m through significant increases in bulk density (1.15 to 1.27 Mg m-3) and cone (tip angle of 60 º) penetrometer resistance (7.18 to 9.37 MPa in summer from ZT to CT, respectively). This caused a reduction in maize root abundance of 40-80 % in CT compared to ZT plots below the induced pans. Two of the studied soils had hard-structured Bt horizons (clay pans), but in only one of them (silty clay loam Abruptic Argiudoll, Villa Lía site) the expected penetrometer resistance increases (up to 9 MPa) were observed with depth. In the other clay pan soil (silty clay loam Vertic Argiudoll, Pérez Millán site), penetrometer resistance did not increase with depth but reached 14.5 MPa at 0.075 and 0.2 m depth in CT and ZT plots, respectively. However, maize root abundance was stratified in the first 0.2 m at the Villa Lía and Pérez Millán sites. There, the hard Bt horizons did not represent an absolute but a relative mechanical impedance to maize roots, by the observed root clumping through desiccation cracks.

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Despite major progress in the understanding of biological mechanisms underlying metastatic prostate cancer, the treatment of men with advanced prostate cancer remains challenging. Several randomized controlled trials with promising or positive results are underway or just released. Here we discuss new treatments which might be used in clinic in the near future: hormonal treatments (Abiraterone and MDV3100), a new chemotherapy (Cabazitaxel), a cellular vaccine (Sipuleucel-T), anti-angiogenic drugs (Bevacizumab, Aflibercept), a new radioactive treatment (Alpharadin) and a new bone-protective agent (Deno-sumab).