Ambulatory blood pressure monitoring: a mean to stratify cardiovascular risk.

OBJECTIVE: Current hypertension guidelines stress the importance to assess total cardiovascular risk but do not describe precisely how to use ambulatory blood pressures in the cardiovascular risk stratification. METHOD: We calculated here global cardiovascular risk according to 2003 European Society of Hypertension/European Society of Cardiology guidelines in 127 patients in whom daytime ambulatory blood pressures were recorded and carotid/femoral ultrasonography performed. RESULTS: The presence of ambulatory blood pressures >or =135/85 mmHg shifted cardiovascular risk to higher categories, as did the presence of hypercholesterolemia and, even more so, the presence of atherosclerotic plaques. CONCLUSION: Further studies are, however, needed to define the position of ambulatory blood pressures in the assessment of cardiovascular risk.

Duality in mean-variance frontiers with conditioning information

Portfolio and stochastic discount factor (SDF) frontiers are usually regarded as dual objects, and researchers sometimes use one to answer questions about the other. However, the introduction of conditioning information and active portfolio strategies alters this relationship. For instance, the unconditional portfolio frontier in Hansen and Richard (1987) is not dual to the unconditional SDF frontier in Gallant, Hansen and Tauchen (1990). We characterise the dual objects to those frontiers, and relate them to the frontiers generated with managed portfolios, which are commonly used in empirical work. We also study the implications of a safe asset and other special cases.

Hypertension is an independent predictor of mean platelet volume in patients with acute ischaemic stroke.

Introduction: Mean platelet volume (MPV) was shown to be significantly increased in patients with acute ischaemic stroke, especially in non-lacunar strokes. Moreover, some studies concluded that increased MPV is related to poor functional outcome after ischaemic stroke, although this association is still controversial. However, the determinants of MPV in patients with acute ischaemic stroke have never been investigated. Subjects and methods: We recorded the main demographic, clinical and laboratory data of consecutive patients with acute (admitted within 24 h after stroke onset) ischaemic stroke admitted in our Neurology Service between January 2003 and December 2008. MPV was generated at admission by the Sysmex XE-2100 automated cell counter (Sysmex Corporation, Kobe, Japan) from ethylenediaminetetraacetic acid blood samples stored at room temperature until measurement. The association of these parameters with MPV was investigated in univariate and multivariate analysis. Results: A total of 636 patients was included in our study. The median MPV was 10.4 ± 0.82 fL. In univariate analysis, glucose (β= 0.03, P= 0.05), serum creatinine (β= 0.002, P= 0.02), haemoglobin (β= 0.009, P < 0.001), platelet count (β=-0.002, P < 0.001) and history of arterial hypertension (β= 0.21, P= 0.005) were found to be significantly associated with MPV. In multivariate robust regression analysis, only hypertension and platelet count remained as independent determinants of MPV. Conclusions: In patients with acute ischaemic stroke, platelet count and history of hypertension are the only determinants of MPV.

What do we actually mean by talent in business? Does it really matter?

[spa] La conceptuación de talento ha ido cobrando cada vez más importancia tanto para académicos como profesionales, con el fin de avanzar en el estudio de la gestión del talento. De hecho, la confusión sobre el significado de talento en la realidad empresarial impide llegar a un consenso sobre el concepto y la práctica de la gestión del talento. En este estudio teórico revisamos el concepto de talento en el mundo de la empresa con el fin de resumir lo que hemos aprendido y discutir las ventajas y limitaciones de las diferentes acepciones. Concluimos con la formulación de una definición de este concepto, ya que una correcta interpretación de la gestión del talento—por no hablar de una exitosa gestión del talento— depende de tener una comprensión clara de lo que se entiende por talento en un contexto organizativo. Además, con la definición de talento propuesta delimitamos el concepto de talento evitando algunos problemas detectados en las definiciones anteriores (por ejemplo, generalidades y tautologías), y poniendo de relieve las variables importantes que le afectan y lo hacen más manejable.

The mean-variance model from the inverse of the variance-covariance matrix

En este artículo, a partir de la inversa de la matriz de varianzas y covarianzas se obtiene el modelo Esperanza-Varianza de Markowitz siguiendo un camino más corto y matemáticamente riguroso. También se obtiene la ecuación de equilibrio del CAPM de Sharpe.

What do we actually mean by talent in business? Does it really matter?

[spa] La conceptuación de talento ha ido cobrando cada vez más importancia tanto para académicos como profesionales, con el fin de avanzar en el estudio de la gestión del talento. De hecho, la confusión sobre el significado de talento en la realidad empresarial impide llegar a un consenso sobre el concepto y la práctica de la gestión del talento. En este estudio teórico revisamos el concepto de talento en el mundo de la empresa con el fin de resumir lo que hemos aprendido y discutir las ventajas y limitaciones de las diferentes acepciones. Concluimos con la formulación de una definición de este concepto, ya que una correcta interpretación de la gestión del talento—por no hablar de una exitosa gestión del talento— depende de tener una comprensión clara de lo que se entiende por talento en un contexto organizativo. Además, con la definición de talento propuesta delimitamos el concepto de talento evitando algunos problemas detectados en las definiciones anteriores (por ejemplo, generalidades y tautologías), y poniendo de relieve las variables importantes que le afectan y lo hacen más manejable.

Modeling premartensitic effects in Ni2MnGa: A mean-field and Monte Carlo simulation study

ic first-order transition line ending in a critical point. This critical point is responsible for the existence of large premartensitic fluctuations which manifest as broad peaks in the specific heat, not always associated with a true phase transition. The main conclusion is that premartensitic effects result from the interplay between the softness of the anomalous phonon driving the modulation and the magnetoelastic coupling. In particular, the premartensitic transition occurs when such coupling is strong enough to freeze the involved mode phonon. The implication of the results in relation to the available experimental data is discussed.

Variational Wigner-Kirkwood approach to relativistic mean field theory

The recently developed variational Wigner-Kirkwood approach is extended to the relativistic mean field theory for finite nuclei. A numerical application to the calculation of the surface energy coefficient in semi-infinite nuclear matter is presented. The new method is contrasted with the standard density functional theory and the fully quantal approach.

External dichotomous noise: The problem of the mean-first-passage time

A retarded backward equation for a non-Markovian process induced by dichotomous noise (the random telegraphic signal) is deduced. The mean-first-passage time of this process is exactly obtained. The Gaussian white noise and the white shot noise limits are studied. Explicit physical results in first approximation are evaluated.

Noise-induced phase separation: Mean-field results

We present a study of a phase-separation process induced by the presence of spatially correlated multiplicative noise. We develop a mean-field approach suitable for conserved-order-parameter systems and use it to obtain the phase diagram of the model. Mean-field results are compared with numerical simulations of the complete model in two dimensions. Additionally, a comparison between the noise-driven dynamics of conserved and nonconserved systems is made at the level of the mean-field approximation.