Quality in Statistical Systems: The Challenge for Puerto Rico

In Puerto Rico, confidence in public data has been deeply compromised. Examination of extant island data demonstrates shortcomings in measuring basic variables that are now crucial in the international context. Demands from researchers, and from governmental and private constituents resulted in Law 209 of August 28, 2003 (The Law).  The Law created the Statistics Institute of Puerto Rico (The Institute) to induce significant changes in statistical production processes and to coordinate the creation of a reliable statistical system for public data on the island.  As part of its mandate, The Institute is implementing a quality assurance process that aims to guarantee rights of all constituents to opportune and reliable information.  This article summarizes and interprets ongoing initiatives taken by The Institute to meet quality assurance objectives of The Law. It also intends to contribute to broader international conversations on statistical quality and its central role in regaining people’s trust in decision making processes.

The pulmonary endothelium contributes to inflammation in chronic heart failure: the role of mechanical strain and bone morphogenetic protein-9

Chronic heart failure (CHF) is a debilitating condition with a poor prognosis. Remodelling of the alveolar capillary membrane (ACM) protects against pulmonary oedema, but also results in dyspnoea and a worsened prognosis. Systemic inflammation associated with CHF contributes to the pathophysiology and mortality of the syndrome. Monocyte chemoattractant protein (MCP)-1, a CC chemokine, is elevated in patients with CHF and associated with increased mortality. Also, deficiencies in the bone morphogentic protein receptor (BMPR) signalling contribute to the pathophysiology of vascular remodelling in pulmonary arterial hypertension (PAH), and similar changes are seen in CHF. The mechanisms underlying lung remodelling and inflammation in CHF are not known. This thesis investigated the contribution of the pulmonary endothelium to inflammation and ACM remodelling in CHF. We hypothesised that pulmonary venous hypertension (PVH) in CHF imparts mechanical strain at the ACM stimulating the release of mediators, contributing to lung remodelling. To model PVH cyclic mechanical strain (CMS) was applied to monolayers of human lung microvascular endothelial cells (HLMVEC) and to an endothelial cell line (EaHy 926). MCP-1 was identified as a stretch-induced inflammatory mediator whose induction was dependent on activation of the extracellular signal-related kinase (ERK 1/2) pathway. Supernatants from stretched compared to non-stretched cells increased fibroblast and pulmonary smooth muscle cell proliferation, and fibroblast differentiation. Bone morphogenetic protein (BMP)-9 stimulated pulmonary arterial endothelial cells to release endothelin-1 (ET-1) in a Smad-independent, p38MAPK-dependent, manner. In a rodent heart failure model, animals subjected to left coronary artery ligation had increased levels of MCP-1 in whole lung, serum and bronchoalveolar lavage. Animals treated with gene therapy (SERCA2a) demonstrated functional rescue with attenuated release of MCP-1 and ET-1. These data support a role for pulmonary ECs in inflammation and remodelling in CHF. Increased understanding of lung remodelling may lead to improved management of dyspnoea for CHF sufferers

Gait analysis in a <i>Mecp2</i> knockout mouse model of Rett syndrome reveals early-onset and progressive motor deficits

Rett syndrome (RTT) is a genetic disorder characterized by a range of features including cognitive impairment, gait abnormalities and a reduction in purposeful hand skills. Mice harbouring knockout mutations in the &lt;i&gt;Mecp2&lt;/i&gt; gene display many RTT-like characteristics and are central to efforts to find novel therapies for the disorder. As hand stereotypies and gait abnormalities constitute major diagnostic criteria in RTT, it is clear that motor and gait-related phenotypes will be of importance in assessing preclinical therapeutic outcomes. We therefore aimed to assess gait properties over the prodromal phase in a functional knockout mouse model of RTT. In male &lt;i&gt;Mecp2&lt;/i&gt; knockout mice, we observed alterations in stride, coordination and balance parameters at 4 weeks of age, before the onset of other overt phenotypic changes as revealed by observational scoring. These data suggest that gait measures may be used as a robust and early marker of &lt;i&gt;Mecp2&lt;/i&gt;-dysfunction in future preclinical therapeutic studies

Evolutionary history of the ADRB2 gene in humans

No abstract available

Oxygen reduction at the silver/hydroxide-exchange membrane interface

A solid-state cell is used to study the electrocatalysis of oxygen reduction at the silver/hydroxide-exchange membrane interface. The catalyst/membrane interface exhibits improved performance in comparison to a catalyst/aqueous sodium hydroxide interface. Surprisingly, the half-wave potential for oxygen reduction is shown to shift 185 mV higher at the silver/hydroxide-exchange membrane interface than for the silver/aqueous hydroxide solution interface, and the exchange current density is significantly higher at 1.02 × 10−6 A m−2. On a cost per performance basis, silver electrocatalysts in a hydroxide-exchange membrane fuel cell may provide better performance than platinum in a proton-exchange membrane fuel cell. Keywords: Oxygen reduction reaction, Electrocatalyst, Alkaline membrane, Solid-state cell, Silve

Carotid artery wall mechanics in young males with high cardiorespiratory fitness

The influence of cardiorespiratory fitness (CRF) on arterial stiffness in young adults remains equivocal. Beyond conventional measures of arterial stiffness, 2D strain imaging of the common carotid artery (CCA) provides novel information related to the intrinsic properties of the arterial wall. Therefore, this study aimed to assess the effect of CRF on both conventional indices of CCA stiffness and 2D strain parameters, at rest and following a bout of aerobic exercise in young healthy males. Short‐axis ultrasound images of the CCA were recorded in 34 healthy men [22 years (95%CI, 19–22)] before, and immediately after 5‐minutes of aerobic exercise (40% VO2max). Images were analysed for arterial diameter, peak circumferential strain (PCS), and peak systolic and diastolic strain rates (S‐SR, D‐SR). Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) were simultaneously assessed and Petersons' elastic modulus (Ep) and Beta stiffness (β1) were calculated. Participants were separated post hoc into moderate and high fitness groups [VO2max: 48.9 ml.kg‐1 min‐1 (95%CI, 44.7–53.2) vs. 65.6 ml.kg‐1 min‐1 (95%CI, 63.1–68.1); P 0.13) but were elevated in the moderate‐fitness group post‐exercise (P 0.05). High‐fit individuals exhibit elevated CCA PCS and S‐SR, which may reflect training‐induced adaptations that help to buffer the rise in pulse‐pressure and stroke volume during exercise

A Gaussian Theory of Superfluid--Bose-Glass Phase Transition

We show that gaussian quantum fluctuations, even if infinitesimal, are sufficient to destroy the superfluidity of a disordered boson system in 1D and 2D. The critical disorder is thus finite no matter how small the repulsion is between particles. Within the gaussian approximation, we study the nature of the elementary excitations, including their density of states and mobility edge transition. We give the gaussian exponent $\eta$ at criticality in 1D and show that its ratio to $\eta$ of the pure system is universal.Comment: Revtex 3.0, 11 pages (4 figures will be sent through airmail upon request

Reproducibility of Shin's method for necrotic core and calcium content in atherosclerotic coronary lesions treated with bioresorbable everolimus-eluting vascular scaffolds using volumetric intravascular ultrasound radiofrequency-based analysis

Although Virtual Histology intravascular ultrasound (VH-IVUS) is increasingly used in clinical research, the reproducibility of plaque composition remains unexplored in significant coronary artery and stented lesions. The purpose of this study was to assess the reproducibility of necrotic core and calcium content in atherosclerotic coronary lesions that were treated with a bioresorbable everolimus-eluting vascular scaffold (BVS) using a new measurement method (Shin's method) by VH-IVUS. Eight patients treated with a BVS (Abbott Vascular, Santa Clara, CA, USA) were analyzed with serial VH-IVUS assessments, i.e., pre- and post-stenting, and at 6 months and 2 years follow-up. A total of 32 coronary segments were imaged to evaluate the reproducibility of volumetric VH-IVUS measurements. In Shin's method, contours are drawn around the IVUS catheter (instead of the lumen) and vessel. Overall, in the imaged coronary segment, for necrotic core and dense calcium volumes, the relative intra-observer differences were 0.30 ± 0.22, 0.19 ± 0.16% for observer 1 and 0.45 ± 0.41, 0.36 ± 0.47% for observer 2, respectively. The interobserver relative differences of necrotic core and dense calcium volumes were 0.51 ± 0.79 and 0.56 ± 1.01%, respectively. The present study demonstrates a good reproducibility for both, intra-observer and interobserver measurements using Shin's method. This method is suitable for the measurement of necrotic core and dense calcium using VH-IVUS in longitudinal studies, especially studies on bioresorbable scaffolds, because the degradation process will be fully captured independently of the location of the struts and their greyscale appearance