University of Costa Rica

About: University of Costa Rica is a education organization based out in San José, Costa Rica. It is known for research contribution in the topics: Population & Venom. The organization has 9817 authors who have published 16781 publications receiving 238208 citations. The organization is also known as: UCR & Universidad de Costa Rica.

Bulk universality for Wigner hermitian matrices with subexponential decay

Abstract: In this paper, we consider the ensemble of $n \times n$ Wigner Hermitian matrices $H = (h_{\ell k})_{1 \leq \ell,k \leq n}$ that generalize the Gaussian unitary ensemble (GUE). The matrix elements $h_{k\ell} = \bar h_{ \ell k}$ are given by $h_{\ell k} = n^{-1/2} ( x_{\ell k} + \sqrt{-1} y_{\ell k} )$, where $x_{\ell k}, y_{\ell k}$ for $1 \leq \ell < k \leq n$ are i.i.d. random variables with mean zero and variance $1/2$, $y_{\ell\ell}=0$ and $x_{\ell \ell}$ have mean zero and variance $1$. We assume the distribution of $x_{\ell k}, y_{\ell k}$ to have subexponential decay. In \cite{ERSY2}, four of the authors recently established that the gap distribution and averaged $k$-point correlation of these matrices were \emph{universal} (and in particular, agreed with those for GUE) assuming additional regularity hypotheses on the $x_{\ell k}, y_{\ell k}$. In \cite{TVbulk}, the other two authors, using a different method, established the same conclusion assuming instead some moment and support conditions on the $x_{\ell k}, y_{\ell k}$. In this short note we observe that the arguments of \cite{ERSY2} and \cite{TVbulk} can be combined to establish universality of the gap distribution and averaged $k$-point correlations for all Wigner matrices (with subexponentially decaying entries), with no extra assumptions.

Perioperative Ultrasound Training in Anesthesiology: A Call to Action.

Abstract: The purpose of this position paper is to define the scope of perioperative ultrasound (US), review the current status of US training practices during anesthesiology residency, and suggest the recommendations for current and future trainees on how to obtain perioperative US proficiency We define per

Cultural orientations and historical changes as predictors of parenting behaviour

Abstract: This study addresses the stability and variability of patterns of parenting in three cultural environments that can be assumed to differ with respect to their cultural models. German middle-class families can be assumed to follow primarily independent socialisation goals, Cameroonian Nso farmers can be assumed to follow primarily interdependent socialisation goals, and Costa Rican families can be assumed to follow an autonomous relational orientation. Parenting patterns of mothers interacting with their 3-month-old babies were assessed at two points in time, being 4 to 6 years apart. The data confirm the predicted cultural differences in style of parenting, which proved to be stable across the covered time span. We also predicted changes in parenting styles that should be oriented to a more independent cultural model across the cultural samples. Our data confirm this hypothesis, although the changes are differentially represented in the three samples, with the Cameroonian Nso sample expressing no significant changes and the German middle-class sample representing the most pronounced changes. The data are interpreted as documenting linkages between parenting and macrolevel societal changes.