782 resultados para stock enhancement
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We re-examine the dynamics of returns and dividend growth within the present-value framework of stock prices. We find that the finite sample order of integration of returns is approximately equal to the order of integration of the first-differenced price-dividend ratio. As such, the traditional return forecasting regressions based on the price-dividend ratio are invalid. Moreover, the nonstationary long memory behaviour of the price-dividend ratio induces antipersistence in returns. This suggests that expected returns should be modelled as an AFIRMA process and we show this improves the forecast ability of the present-value model in-sample and out-of-sample.
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During the 1981 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) Cuban epidemic, bronchial asthma (BA) was frequently found as a personal or family antecedent in dengue hemorragic fever patients. Considering that antibody dependent enhancement (ADE) plays an important role in the etiopathogenic mechanism of DHF/DSS, we decide to study the Dengue 2 virus (D2V) capability of replication in peripheral blood leukocytes (PBL) from asthmatic patients and healthy persons. In 90% of asthmatic patients and 53.8% of control group it was obtained PBL with a significant D2V enhancing activity (X² p < 0.01). Power enhancement was higher in asthmatic group. This is the first in vitro study relating BA and the dengue 2 virus immuno enhancement. The results obtained support the role of BA as a risk factor for DHF/DSS as already described on epidemiological data.
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Different patterns of cutaneous leishmaniasis can be induced when a challenge of alike dose of Leishmania amazonensis amastigotes in various inbred strains was applied. Two strains of mice, the Balb/c and C57 BL/10J, showed exceptional suscepbility, and 10(elevado a sexta potência) amastigotes infective dose lead, to ulcerative progressive lesions with cutaneous metastasis and loss by necrosis of leg on wich the footpad primary lesion occured. Lesions were also progressive but in a lower degree when C3H/HeN and C57BL/6 were infected. Lesions progress slowly in DBA/2 mice presenting lesions wich reach a discreet peack after 12 weeks, do not heal but do not uncerate. DBA/2 mice is, therefore, a good model for immunomodualtion. In attempt to determine the influence of BCG in vaccination schedule using microsomal fraction, DBA/2 became an excellent model, since it is also a non-responder to BCG. Vaccination of DBA/2 mice, receiving the same 10(elevado a sexta potência) BCG viable dose and 10 *g or 50 *g of protein content of microsomal fraction, lead to a progressive disease with time course similar to those observed in susceptible non-vaccinated C57BL/10J mice after 6 months of observation. An enhancement of infection in BCG non-responder mice suggests that use of BCG as immunostimulant in humans could be critical for both vaccination and immunoprophylactic strategies.
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PhD graduates hold the highest education degree, are trained to conduct research and can be considered a key element in the creation, commercialization and diffusion of innovations. The impact of PhDs on innovation and economic development takes place through several channels such as the accumulation of scientific capital stock, the enhancement of technology transfers and the promotion of cooperation relationships in innovation processes. Although the placement of PhDs in industry provides a very important mechanism for transmitting knowledge from universities to firms, information about the characteristics of the firms that employ PhDs is very scarce. The goal of this paper is to improve understanding of the determinants of the demand for PhDs in the private sector. Three main potential determinants of the demand for PhDs are considered: cooperation between firms and universities, R&D activities of firms and several characteristics of firms, size, sector, productivity and age. The results from the econometric analysis show that cooperation between firms and universities encourages firms to recruit PhDs and point to the existence of accumulative effects in the hiring of PhD graduates.
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Tobacco consumption is a global epidemic responsible for a vast burden of disease. With pharmacological properties sought-after by consumers and responsible for addiction issues, nicotine is the main reason of this phenomenon. Accordingly, smokeless tobacco products are of growing popularity in sport owing to potential performance enhancing properties and absence of adverse effects on the respiratory system. Nevertheless, nicotine does not appear on the 2011 World Anti-Doping Agency (WADA) Prohibited List or Monitoring Program by lack of a comprehensive large-scale prevalence survey. Thus, this work describes a one-year monitoring study on urine specimens from professional athletes of different disciplines covering 2010 and 2011. A method for the detection and quantification of nicotine, its major metabolites (cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide) and minor tobacco alkaloids (anabasine, anatabine and nornicotine) was developed, relying on ultra-high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-TQ-MS/MS). A simple and fast dilute-and-shoot sample treatment was performed, followed by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) operated in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM) data acquisition. After method validation, assessing the prevalence of nicotine consumption in sport involved analysis of 2185 urine samples, accounting for 43 different sports. Concentrations distribution of major nicotine metabolites, minor nicotine metabolites and tobacco alkaloids ranged from 10 (LLOQ) to 32,223, 6670 and 538 ng/mL, respectively. Compounds of interest were detected in trace levels in 23.0% of urine specimens, with concentration levels corresponding to an exposure within the last three days for 18.3% of samples. Likewise, hypothesizing conservative concentration limits for active nicotine consumption prior and/or during sport practice (50 ng/mL for nicotine, cotinine and trans-3-hydroxycotinine and 25 ng/mL for nicotine-N'-oxide, cotinine-N-oxide, anabasine, anatabine and nornicotine) revealed a prevalence of 15.3% amongst athletes. While this number may appear lower than the worldwide smoking prevalence of around 25%, focusing the study on selected sports highlighted more alarming findings. Indeed, active nicotine consumption in ice hockey, skiing, biathlon, bobsleigh, skating, football, basketball, volleyball, rugby, American football, wrestling and gymnastics was found to range between 19.0 and 55.6%. Therefore, considering the adverse effects of smoking on the respiratory tract and numerous health threats detrimental to sport practice at top level, likelihood of smokeless tobacco consumption for performance enhancement is greatly supported.
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Studies of Spanish cooperatives date their spread from the Law on Agrarian Syndicates of 1906. But the first legislative appearance of cooperatives is an 1869 measure that permitted general incorporation for lending companies. The 1931 general law on cooperatives, which was the first act permitting the formation of cooperatives in any activity, reflects the gradual disappearance of the cooperative’s "business" characteristics. In this paper we trace the Spanish cooperative’s legal roots in business law and its connections to broader questions of the freedom of association, the formation of joint-stock enterprises, and the liability of investors in business and cooperative entities. Our account underscores the similarities of the organizational problems approach by cooperatives and business firms, while at the same time respecting the distinctive purposes cooperatives served.
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Abstract: We scrutinize the realized stock-bond correlation based upon high frequency returns. We use quantile regressions to pin down the systematic variation of the extreme tails over their economic determinants. The correlation dependence behaves differently when the correlation is large negative and large positive. The important explanatory variables at the extreme low quantile are the short rate, the yield spread, and the volatility index. At the extreme high quantile the bond market liquidity is also important. The empirical fi ndings are only partially robust to using less precise measures of the stock-bond correlation. The results are not caused by the recent financial crisis. Keywords: Extreme returns; Financial crisis; Realized stock-bond correlation; Quantile regressions; VIX. JEL Classifi cations: C22; G01; G11; G12
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The multiplicity of cell death mechanisms induced by neonatal hypoxia-ischemia makes neuroprotective treatment against neonatal asphyxia more difficult to achieve. Whereas the roles of apoptosis and necrosis in such conditions have been studied intensively, the implication of autophagic cell death has only recently been considered. Here, we used the most clinically relevant rodent model of perinatal asphyxia to investigate the involvement of autophagy in hypoxic-ischemic brain injury. Seven-day-old rats underwent permanent ligation of the right common carotid artery, followed by 2 hours of hypoxia. This condition not only increased autophagosomal abundance (increase in microtubule-associated protein 1 light chain 3-11 level and punctuate labeling) but also lysosomal activities (cathepsin D, acid phosphatase, and beta-N-acetylhexosaminidase) in cortical and hippocampal CA3-damaged neurons at 6 and 24 hours, demonstrating an increase in the autophagic flux. In the cortex, this enhanced autophagy may be related to apoptosis since some neurons presenting a high level of autophagy also expressed apoptotic features, including cleaved caspase-3. On the other hand, enhanced autophagy in CA3 was associated with a more purely autophagic cell death phenotype. In striking contrast to CA3 neurons, those in CA1 presented only a minimal increase in autophagy but strong apoptotic characteristics. These results suggest a role of enhanced autophagy in delayed neuronal death after severe hypoxia-ischemia that is differentially linked to apoptosis according to the cerebral region.
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Abstract: We analyze the realized stock-bond correlation. Gradual transitions between negative and positive stock-bond correlation is accommodated by the smooth transition regression (STR) model. The changes in regime are de ned by economic and financial transition variables. Both in sample and out-of- sample results document that STR models with multiple transition variables outperform STR models with a single transition variable. The most important transition variables are the short rate, the yield spread, and the VIX volatility index. Keywords: realized correlation; smooth transition regressions; stock-bond correlation; VIX index JEL Classifi cations: C22; G11; G12; G17
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El objetivo de este proyecto es desarrollar una aplicación web que sirva y gestione una tienda de música, tanto para su tienda física como para su tienda online. La aplicación Web está gestionada por los usuarios "administrador" y utilizada por los dos tipos de usuarios: administradores y clientes. Sus principales funciones son: Introducción y modificación de artículos. Gestión de entradas y salidas de productos. Gestión de pedidos. Obtención de datos para la gestión de la empresa. Minimizar los errores de gestión. Mejorar la imagen de la empresa. Ampliar los ámbitos de negocio. Correcta visualización de los artículos. Facilitar la búsqueda y compra de artículos.
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OBJECTIVES: The pre-treatment of tumour neovessels by low-level photodynamic therapy (PDT) improves the distribution of concomitantly administered systemic chemotherapy. The mechanism by which PDT permeabilizes the tumour vessel wall is only partially known. We have recently shown that leukocyte-endothelial cell interaction is essential for photodynamic drug delivery to normal tissue. The present study investigates whether PDT enhances drug delivery in malignant mesothelioma and whether it involves comparable mechanisms of actions. METHODS: Human mesothelioma xenografts (H-meso-1) were grown in the dorsal skinfold chambers of 28 nude mice. By intravital microscopy, the rolling and recruitment of leukocytes were assessed in tumour vessels following PDT (Visudyne(®) 400 μg/kg, fluence rate 200 mW/cm(2) and fluence 60 J/cm(2)) using intravital microscopy. Likewise, the distribution of fluorescently labelled macromolecular dextran (FITC-dextran, MW 2000 kDa) was determined after PDT. Study groups included no PDT, PDT, PDT plus a functionally blocking anti-pan-selectin antibody cocktail and PDT plus isotype control antibody. RESULTS: PDT significantly enhanced the extravascular accumulation of FITC-dextran in mesothelioma xenografts, but not in normal tissue. PDT significantly increased leukocyte-endothelial cell interaction in tumour. While PDT-induced leukocyte recruitment was significantly blunted by the anti-pan-selectin antibodies in the tumour xenograft, this manipulation did not affect the PDT-induced extravasation of FITC-dextran. CONCLUSIONS: Low-level PDT pre-treatment selectively enhances the uptake of systemically circulating macromolecular drugs in malignant mesothelioma, but not in normal tissue. Leukocyte-endothelial cell interaction is not required for PDT-induced drug delivery to malignant mesothelioma.
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We investigated the presence of Candida dubliniensis among isolates previously identified as Candida albicans and maintained in a yeast stock collection from 1994 to 2000. All isolates were serotyped and further evaluated for antifungal susceptibility profile. After doing a screening test for C. dubliniensis isolates based on the capability of colonies to grow at 42°C, its final identification was obtained by randomly amplified polymorphic DNA (RAPD) analysis using three different primers. A total of 46 out of 548 screened isolates did not exhibit growth at 42°C and were further genotyped by RAPD. Eleven isolates were identified as C. dubliniensis with RAPD analysis. Regarding serotypes, 81.5% of C. albicans and all C. dubliniensis isolates belonged to serotype A. Of note, 9 out of 11 C. dubliniensis isolates were obtained from patients with acquired immunodeficiency syndrome (Aids) and all of them were susceptible to azoles and amphotericin B. We found 17 (3%) C. albicans isolates that were dose-dependent susceptibility or resistant to azoles. In conclusion, we found a low rate of C. dubliniensis isolates among stock cultures of yeasts previously identified as C. albicans. Most of these isolates were recovered from oral samples of Aids patients and exhibited high susceptibility to amphotericin B and azoles. C. albicans serotype A susceptible to all antifungal drugs is the major phenotype found in our stock culture.
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Foodborne disease is a source of increasing morbidity and fatality in the island of Ireland. It also has an economic impact. As a result of the continuing concern about food safety and its implications on an all-island basis, the North/South Ministerial Council established the Food Safety Promotion Board (FSPB) on December 2nd 1999. At its Board meeting in February 2000, the FSPB considered the issue of microbiological surveillance and, in noting the complexity of the issues, recommended that the key players in foodborne disease surveillance in Northern Ireland and the Republic of Ireland consider ways for the improvement of microbiological surveillance on an all-island basis. To assist in the development of a surveillance strategy for the FSPB, a Functional Meeting Group on Disease Surveillance was convened. The group compiled this consultation paper. A series of recommendations are made in the consultation paper and the key recommendations are summarised below.
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The course of in vivo infection of five isolates of Yersinia pseudotuberculosis was followed for three weeks in Swiss mice. The strains were isolated from diarrheic and normal feces and mesenteric lymph nodes of healthy and sick stock animals. Four strains of serogroup O:3 and one of serogroup O:1a, with and without the virulence plasmid, were inoculated intragastrically and intravenously in the mice. Groups of five animals were sacrificed at 6 h and 3, 6, 10, 15, and 21 days after inoculation, and organs and tissues were checked for possible macroscopic alterations. Development of infection was monitored at these times by performing viable bacterial counts in homogenates of selected tissues. The animals were cheked daily for clinical alterations. The results of the study showed that strains with the virulence plasmid infected organs and tissues at various times and at varying intensity by both routes of infection, the strain of type O:1a being the most invasive. Moreover, clinical and pathological alterations occurred only in animals inoculated with bacteria carrying the virulence plasmid, regardless of the route of infection.