416 research outputs found
Análisis de la heurÃstica en la contratación empresarial a través de una cartera de derivados reales
Departing from the notion that labour legislation should be founded in the generation of job stability a model for recruitment is presented in which the employer is likened to the holder of an investment portfolio containing two real derivatives – swap or the option of sale. This model allows us on one hand to analyze sensitivity to the variables that are at play in an employment contract and, on the other, look at the effects that the most recent reforms in Spanish labour laws have had on contracting decisions made by employers. The results are clear: social security benefits are shown to be the most sensitive variable on the work contract, and applying the changes proposed in the latest labour reforms, this effect is upheld. The study concludes that reducing the costs of dismissal does not increase the likelihood of employers’ taking on new staff.Dada la situación actual y partiendo del supuesto que como herramienta para una correcta polÃtica de empleo la legislación laboral debe sentar las bases sólidas para que en el momento de recuperación económica se generen puestos de trabajo estables, se presenta un modelo de simulación de contratación que nos va a permitir un análisis de sensibilidad de las distintas variables a tener en cuenta en una regulación del mercado laboral. El modelo consiste en asimilar el comportamiento del empresario al del propietario de una cartera de inversión compuesta por dos derivados reales, un swap y una opción de venta americana. Este modelo nos permite, por un lado, hacer un análisis de sensibilidad de las diferentes variables que intervienen en la contratación, y, por otro lado, analizar los efectos que la última reforma laboral española tiene sobre la decisión de contratar del empresario. Los resultados son claros, la variable que más sensibilidad presenta sobre la contratación es la cuota patronal de la seguridad social, y aplicando los cambios propuestos en esta última reforma laboral, se concretan estos efectos y también se concluye que la reducción de los costes de despido no acelera la decisión de contratar.Dada a situação atual e partindo do suposto que como ferramenta para uma correta polÃtica de emprego, a legislação laboral deve instituir as bases sólidas para que, no momento da recuperação econômica, se gerem postos de trabalho estáveis, se apresentem um modelo de simulação de contratação que nos permitirá uma análise de sensibilidade das diferentes variáveis a considerar em uma regulação do mercado laboral. O modelo consiste em assimilar o comportamento do empresário ao do proprietário de uma carteira de investimento composto por dois derivados reais, um swap e uma opção de venda americana. Esse modelo nos permite, por um lado, fazer uma análise de sensibilidade das diferentes variáveis que intervêm na contratação e, por outro lado, analisar os efeitos que a última reforma laboral espanhola tem sobre a decisão de contratar do empresário. Os resultados são claros, a variável que mais sensibilidade apresenta sobre a contratação é a cota patronal da previdência social e aplicando as mudanças propostas nesta última reforma laboral, concretizam-se esses efeitos e também se conclui que a redução dos custos de demissão não acelera a decisão de contrata
The subconvexity problem for \GL_{2}
Generalizing and unifying prior results, we solve the subconvexity problem
for the -functions of \GL_{1} and \GL_{2} automorphic representations
over a fixed number field, uniformly in all aspects. A novel feature of the
present method is the softness of our arguments; this is largely due to a
consistent use of canonically normalized period relations, such as those
supplied by the work of Waldspurger and Ichino--Ikeda.Comment: Almost final version to appear in Publ. Math IHES. References
updated
Mass equidistribution of Hilbert modular eigenforms
Let F be a totally real number field, and let f traverse a sequence of
non-dihedral holomorphic eigencuspforms on GL(2)/F of weight (k_1,...,k_n),
trivial central character and full level. We show that the mass of f
equidistributes on the Hilbert modular variety as max(k_1,...,k_n) tends to
infinity.
Our result answers affirmatively a natural analogue of a conjecture of
Rudnick and Sarnak (1994). Our proof generalizes the argument of
Holowinsky-Soundararajan (2008) who established the case F = Q. The essential
difficulty in doing so is to adapt Holowinsky's bounds for the Weyl periods of
the equidistribution problem in terms of manageable shifted convolution sums of
Fourier coefficients to the case of a number field with nontrivial unit group.Comment: 40 pages; typos corrected, nearly accepted for
Analyzing Zero Returns to Education in Germany: Heterogeneous Effects and Skill Formation
Long-term field studies of lemurs, lorises, and tarsiers
Lemurs, lorises, and tarsiers are socially and ecologically diverse primates that include some of the most endangered mammals. We review results of long-term studies of 15 lemur species from 7 sites in Madagascar and 1 species each of loris and tarsier in Indonesia. We emphasize that the existence of long-term study populations is a crucial prerequisite for planning and conducting shorter studies on specific topics, as exemplified by various ecophysiological studies of lemurs. Extended studies of known individuals have revealed variation in social organization within and between ecologically similar species. Even for these primates with relatively fast life histories, it required more than a decade of paternity data to characterize male reproductive skew. The long-term consequences of female rank on reproductive success remain poorly known, however. Long-term monitoring of known individuals is the only method to obtain data on life-history adaptations, which appear to be shaped by predation in the species covered here; long-term studies are also needed for addressing particular questions in community ecology. The mere presence of long-term projects has a positive effect on the protection of study sites, and they generate unique data that are fundamental to conservation measures, such as close monitoring of populations.
Los lémures, lorises y tarseros son grupos de primates, muy diversos social y ecológicamente, que incluyen algunas de las especies de mamÃferos más amenazadas. Se revisaron los resultados de estudios a largo plazo de 15 especies de lémures en 7 áreas de estudio en Madagascar y una especie de loris y otra de tarsero, en Indonesia. Se resalta la importancia de las áreas de estudio a largo plazo como prerrequisito esencial para planear y llevar a cabo estudios de menor duración sobre temas especificos, como lo ejemplifican varios estudios eco-fisiológicos en lemurs. Estudios a largo plazo de individuos conocidos, han revelado variacion en la organizacion social dentro y entre especies ecologicamente similares. Incluso en estos primates, con un ciclo de vida relativamente corto, se necesita recopilar más de una década de datos de paternidad para determinar el sesgo reproductivo de los machos. Sin embargo, aún se sabe poco de las consecuencias a largo plazo que la posición de las hembras en la jerarquÃa social puede tener en su éxito reproductivo. El monitoreo a largo plazo de individuos conocidos es el unico metodo para obtener datos sobre adaptaciones en su history natural, las cuales aparentemente son moduladas en function de la predacion a las especies estudiadas en este trabajo. Estos estudios a largo plazo son tambien necesarios para afrontar temas especÃficos sobre la ecologÃa de estas comunidades. La simple presencia de proyectos a largo plazo tienen un efecto positive en la proteccion de los lugares de studio, como asi tambien generan datos unicos que son fundamentals para apoyar medidas de conservacion tales como el monitoreo de poblaciones
Detection of Progeny Immune Responses after Intravenous Administration of DNA Vaccine to Pregnant Mice
A number of factors influence the development of tolerance, including the nature, concentration and mode of antigen presentation to the immune system, as well as the age of the host. The studies were conducted to determine whether immunizing pregnant mice with liposome-encapsulated DNA vaccines had an effect on the immune status of their offspring. Two different plasmids (encoding antigens from HIV-1 and influenza virus) were administered intravenously to pregnant mice. At 9.5 days post conception with cationic liposomes, injected plasmid was present in the tissues of the fetus, consistent with trans-placental transfer. When the offspring of vaccinated dams were immunized with DNA vaccine, they mounted stronger antigen-specific immune responses than controls and were protected against challenge by homologous influenza virus after vaccination. Moreover, such immune responses were strong in the offspring of mothers injected with DNA plasmid 9.5 days after coitus. These results suggest that DNA vaccinated mothers confer the antigen-specific immunity to their progeny. Here we describe the methods in detail as they relate to our previously published work
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