Bayesian nonparametric inference for the covariate-adjusted ROC curve

Accurate diagnosis of disease is of fundamental importance in clinical practice and medical research. Before a medical diagnostic test is routinely used in practice, its ability to distinguish between diseased and nondiseased states must be rigorously assessed through statistical analysis. The receiver operating characteristic (ROC) curve is the most popular used tool for evaluating the discriminatory ability of continuous-outcome diagnostic tests. It has been acknowledged that several factors (e.g., subject-specific characteristics, such as age and/or gender) can affect the test's accuracy beyond disease status. Recently, the covariate-adjusted ROC curve has been proposed and successfully applied as a global summary measure of diagnostic accuracy that takes covariate information into account. We motivate the use of the covariate-adjusted ROC curve and develop a highly robust model based on a combination of B-splines dependent Dirichlet process mixture models and the Bayesian bootstrap. Multiple simulation studies demonstrate the ability of our model to successfully recover the true covariate-adjusted ROC curve and to produce valid inferences in a variety of complex scenarios. Our methods are motivated by and applied to an endocrine study where the main goal is to assess the accuracy of the body mass index, adjusted for age and gender, for predicting clusters of cardiovascular disease risk factors. The R-package AROC, implementing our proposed methods, is provided

Application Of Optical Method In Measuring Mechanical Vibrations In A Cantilever Beam

The pertinent literature discloses a family of optical profile measuring techniques highlighting the moire methods. The Moire technique is based on the interference of two superimposed optical grids which produce fringe patterns which can be processed to analyze the DYNAMIC MEASUREMENT IN MATERIALS mechanical behavior. The goal of this research is to experimentally determine the mechanical displacement of a slim cantilever beam by means of Moire technique with Phase Shift. Photomechanical experimental arrangement included a digital camera, a multimedia projector and a PC. The occurrence of oscillations has been adequately analyzed. The results showed data from which useful information can withdraw, being of great importance to support agricultural machinery projects and development.371849

Tatu-Bolinha (artrópodo, gênero Armadillium) como ferramenta de ecoalfabetização.

A cultura ocidental promove o distanciamento dos fundamentos ecológicos, o que gera desequilíbrios como os decorrentes da substituição das funções ecológicas da biodiversidade pelos agrotóxicos. Os relatos apresentados proveem de atividades de Educação Ambiental com ênfase na ecoalfabetização, desenvolvidas à partir de 2005, em Sete Lagoas, MG. O Projeto de Ecoalfabetização Tatu Bolinha foi idealizado para ampliar a discussão relativa à biodiversidade em curso de formação de professores de Geografia nas Faculdades UNIFEMM. Foram desenvolvidos trabalhos relativos à absorção de água pelas fezes do tatu-bolinha, resgate de convivência com a biodiversidade, contação de história, história em quadrinho, matéria ilustrada no "Jornal do Manuelzão", projeto pedagógico com terráreo, ferramenta no Programa Embrapa & Escola e teatro de bonecos. A fundamentação ecológica é ferramenta para contribuir com a transição da cultura antropocêntrica por uma cultura que incorpore as leis naturais e valorize a diversidade

Implementation of a low cost data acquisition board for photovoltaic arrays analysis and diagnostic

Testing PV modules are one of the important procedures to ensure the conformity with the standards and quality of this equipment’s. To implement some of the PV modules tests a data acquisition system is required. This paper presents the design and implementation of a data acquisition system for photovoltaic systems. The developed system is characterized by a low cost board based on a microcontroller. The description of the hardware as well an application to test its performance is presented. The developed system can be used for reading, storing and analyzing information from several photovoltaic systems. Experimental tests are presented to confirm the characteristics of the developed data acquisition board.Com o apoio RAADRI

Challenges to Domesticating Native Forage Legumes

If ruminant production from cultivated and natural grasslands is to depend less on petroleum-based products, forage legumes must serve as protein sources. Commercially available legumes for warm-dry climate grasslands are, however, very limited and resources available for developing such legumes are inadequate. Indeterminate flowering and dehiscent seed pods combined with the need for specialized seed harvesting equipment are major impediments (Butler and Muir 2012). Warm climates often present environmental challenges such as poor rainfall distribution, extended dry seasons, temperature extremes and aggressive grass species (Muir et al. 2011). Erosion of indigenous knowledge and replacement with inappropriate land management approaches from moist-temperate regions compound the challenges

Discriminant analysis of pyrrolizidine alkaloid contamination in bee pollen based on near-infrared data from lab-stationary and portable spectrometers

Bee pollen may be contaminated with pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs), which are mainly detected by liquid chromatography coupled to tandem mass spectrometry (LC\u2013MS/MS), even though the use of fast near-infrared (NIR) spectroscopy is an ongoing alternative. Therefore, the main challenge of this study was to assess the feasibility of both a lab-stationary (Foss) and a portable (Polispec) NIR spectrometer in 60 dehydrated bee pollen samples. After an ANOVA-feature selection of the most informative NIR spectral data, canonical discriminant analysis (CDA) was performed to distinguish three quantitative PA/PANO classes (\ub5g/kg): 400, high. According to the LC\u2013MS/MS analysis, 77% of the samples were contaminated with PAs/PANOs and the sum content of the 17 target analytes was higher than 400\ua0\ub5g/kg in 28% of the samples. CDA was carried out on a pool of 18 (Foss) and 22 (Polispec) selected spectral variables and allowed accurate classification of samples from the low class as confirmed by the high values of Matthews correlation coefficient ( 65 0.91) for both NIR spectrometers. Leave-one-out cross-validation highlighted precise recognition of samples characterised by a high PA/PANO content with a low misclassification rate (0.02) as false negatives. The most informative wavelengths were within the 2400\ua0nm regions for Foss and > 1500\ua0nm for Polispec that could be associated with cyclic amines, and epoxide chemical structures of PAs/PANOs. In sum, both lab-stationary and portable NIR systems are reliable and fast techniques for detecting PA/PANO contamination in bee pollen

Design and Evaluation of HTTP Protocol Parsers for IPFIX Measurement

In this paper we analyze HTTP protocol parsers that provide a web traffic visibility to IP flow. Despite extensive work, flow meters generally fall short of performance goals due to extracting application layer data. Constructing effective protocol parser for in-depth analysis is a challenging and error-prone affair. We designed and evaluated several HTTP protocol parsers representing current state-of-the-art approaches used in today's flow meters. We show the packet rates achieved by respective parsers, including the throughput decrease (performance implications of application parser) which is of the utmost importance for high-speed deployments.Článek zkoumá syntaktické analyzátory HTTP protokolu, které rozšiřují síťové toky o informace z webového provozu. Výpočetně náročné získávání informací z aplikační vrstvy má vliv na výkon měřicích sond a může vést k výraznému poklesu jejich výkonu. Tvorba rychlého analyzátoru pro hloubkovou analýzu HTTP protokolu je náročný proces s ohledem na správné a včasné zpracování dat ze sítě. Článek porovnává naši implementaci vybraných metod pro analýzu HTTP provozu, které jsou v současnosti používány v sondách na měření síťových toků. Provedená měření ukazují množství paketů, které je sonda schopna zpracovat při zapnuté analýze HTTP a jak toto množství klesá oproti sondám, které analýzu aplikačních protokolů neprovádějí. Jedná se o významnou informaci pro nasazení měřicích sond ve vysokorychlostních sítích

Trends in utilisation of ultrasound by older Australians (2010-2019)

Background: Older people have increasingly complex healthcare needs, often requiring appropriate access to diagnostic imaging, an essential component of their health and disease management planning. Ultrasound is a safe imaging tool used to diagnose several conditions commonly experienced by older people such as deep vein thrombosis. Purpose To evaluate the utilisation of major ultrasound services by Australians≥65 years old between 2009- and 2019. Methods: This population-based and yearly cross-sectional study of ultrasound utilisation per 1,000 Australians≥65 years old was conducted using publicly available data sources. Overall, examination site and age- and sexspecifc incidence rate (IR) of ultrasound per 1,000 people, adjusted incidence rate ratios (IRRs) and 95% confdence intervals (CIs) were calculated using negative binomial regression models. Results: Over the study period, the crude utilisation of ultrasound increased by 83% in older Australians. Most ultrasound examinations were conducted on extremities (39%) and the chest (21%), with 25% of all ultrasounds investigating the vascular system. More men than women use ultrasounds of the chest (184/1,000 vs 268/1,000 people), particularly echocardiograms (177/1,000 vs 261/1,000 people), and abdomen (88/1,000 vs 92/1,000 people), especially in those≥85 years old. Hip and pelvic ultrasound were used more by women than men (212/1,000 vs 182/1,000 people). There were increases in vascular abdominal (IRR:1.07, 95%CI:1.06–1.08) and extremeties (IRR:1.06, 95%CI:1.05– 1.07) ultrasounds over the study period, particularly in≥75 years old men. Conclusions: Ultrasound is a common and increasingly used diagnostic tool for conditions commonly experienced by older Australians.Virginie Gaget, Maria C. Inacio, David R. Tivey, Robert N. Jorissen, Wendy J. Babidge, Renuka Visvanathan, and Guy J. Madder