Twenty-five years of aerodynamic research with IR imaging: A survey

Infrared imaging used in aerodynamic research evolved during the last 25 years into a rewarding experimental technique for investigation of body-flow viscous interactions, such as heat flux determination and boundary layer transition. The technique of infrared imaging matched well its capability to produce useful results, with the expansion of testing conditions in the entire spectrum of wind tunnels, from hypersonic high-enthalpy facilities to cryogenic transonic wind tunnels. With unique achievements credited to its past, the current trend suggests a change in attitude towards this technique: from the perception as an exotic, project-oriented tool, to the status of a routine experimental procedure

Convective response of a wall-mounted hot-film sensor in a shock tube

Shock tube experiments were performed in order to determine the response of a single hot-film element of a sensor array to transiently induced flow behind weak normal shock waves. The experiments attempt to isolate the response due only to the change in convective heat transfer at the hot-film surface mounted on the wall of the shock tube. The experiments are described, the results being correlated with transient boundary layer theory and compared with an independent set of experimental results. One of the findings indicates that the change in the air properties (temperature and pressure) precedes the air mass transport, causing an ambiguity in the sensor response to the development of the velocity boundary layer. Also, a transient, local heat transfer coefficient is formulated to be used as a forcing function in an hot-film instrument model and simulation which remains under investigation

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention

Altered Bile Acid Metabolome in Patients with Nonalcoholic Steatohepatitis

BACKGROUND & AIMS: The prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) is increasing at an alarming rate. The role of bile acids in the development and progression of NAFLD to NASH and cirrhosis is poorly understood. This study aimed to quantify the bile acid metabolome in healthy subjects and patients with non-cirrhotic NASH under fasting conditions and after a standardized meal. METHODS: Liquid chromatography tandem mass spectroscopy was used to quantify 30 serum and 16 urinary bile acids from 15 healthy volunteers and 7 patients with biopsy-confirmed NASH. Bile acid concentrations were measured at two fasting and four post-prandial timepoints following a high-fat meal to induce gallbladder contraction and bile acid reabsorption from the intestine. RESULTS: Patients with NASH had significantly higher total serum bile acid concentrations than healthy subjects under fasting conditions (2.2- to 2.4-fold increase in NASH; NASH: 2595–3549 μM and healthy: 1171–1458 μM) and at all post-prandial time points (1.7- to 2.2-fold increase in NASH; NASH: 4444–5898 μM and healthy: 2634–2829 μM). These changes were driven by increased taurine- and glycine-conjugated primary and secondary bile acids. Patients with NASH exhibited greater variability in their fasting and post-prandial bile acid profile. CONCLUSIONS: Results indicate that patients with NASH have higher fasting and post-prandial exposure to bile acids, including the more hydrophobic and cytotoxic secondary species. Increased bile acid exposure may be involved in liver injury and the pathogenesis of NAFLD and NASH

Reavaliando o estatuto silábico das seqüências obstruinte+lateral em português europeu Reevaluating the syllabic status of obstruent+lateral clusters in European Portuguese

Segundo as descrições fonológicas e as normas ortográficas do português, todas as sequências Obstruinte+Líquida constituiriam, nesta língua, sequências tautossilábicas (Ataques ramificados), sendo heterossilábicas todas as restantes sequências C1C2. Porém, aplicando às sequências Obstruinte+Lateral alguns dos critérios que levam à classificação à parte das sequências heterossilábicas - origem histórica e certas manifestações externas do conhecimento fonológico (CF) dos falantes -, verificamos que as sequências Obstruinte+Lateral se comportam frequentemente como as sequências heterossilábicas, sobretudo quando, no tocante às manifestações do CF, se olha a dados obtidos com sujeitos sem conhecimento ortográfico. Esta verificação leva-nos a caracterizar as sequências Obstruinte+Lateral do português europeu como genuinamente heterossilábicas e, paralelamente, a aceitar a interferência do conhecimento ortográfico sobre o conhecimento fonológico dos falantes.<br>According to the phonological descriptions and the orthographic rules of Portuguese, all Portuguese Obstruent+Liquid clusters are licensed as branching onsets, whilst all the other C1C2 strings are classified as heterosyllabic. Nevertheless, if Obstruent+Lateral clusters are subject to the criteria that keep the heterosyllabic clusters apart - such as their historical origin and certain externally observable aspects of the speakers' phonological knowledge - it becomes apparent that the Obstruent+Lateral clusters share some common features with the heterosyllabic clusters, namely when data from subjects without orthographic knowledge are taken into account. Therefore, we propose that European Portuguese Obstruent+Lateral clusters should be classified as genuinely heterosyllabic. In addition, we accept the influence of orthographic knowledge on the subjects' phonological knowledge