Rodrigo A. Vaca Ramírez

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The offspring of diabetic mothers have a 10 times higher frequency of congenital malformations and 5 times higher frequency of spontaneous abortions. Since the discovery of insulin, the prognosis of pregnancies has improved, both for the mother and the offspring. However, the prevalence of congenital malformations at birth has not decreased significantly.(More)
OBJECTIVE To determine the incidence of bronchopulmonary dysplasia, its risk factors and resource utilization in a large South American population of very low birth weight infants. METHODS Prospectively collected data in infants weighing 500 to 1,500 g born at 16 NEOCOSUR Network centers from 10/2000 through 12/2003. Multivariate relative risk and 95%(More)
A stable marriage framework for distributed virtual MIMO coalition formation. HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.(More)
From August 60 to December 90, 103 male newborns with hypospadias were diagnosed among 124 588 consecutive newborns examined (8.3 per 10,000). Mortality among them was 1.94%. The annual incidence rate increased significantly over the study period (p < 0.001. Hypospadias was an isolated finding in 92% of cases, and its was associated to other non genital(More)
An heterogeneous group of newborns with different gestational ages, birth weight, nutritional status and different risks of morbidity and mortality are classified as premature. Therefore the definition of premature children subgroups is mandatory. Very low weight premature babies are those with a birth weight of less than 1500 g. In Chile, they correspond(More)
In this paper, we aim to reduce the power expenditure in the reverse link during low network load periods, by allocating extra resource blocks (RBs) to the mobile users. Thereby, the user's rate demands are split among its allocated RBs in order to transmit in each of them by using a low level modulation order. We model the bandwidth expansion (BE) process(More)
The handoff decision among heterogeneous wireless networks is a very important issue for integrating WLANs and cellular networks. Such networks exhibit different characteristics with respect to bandwidth, latency, power, and their charge model as well. In this paper, we present extensive numerical simulations of a novel vertical handover mechanism, which we(More)