Berry-phase treatment of the homogeneous electric field perturbation in insulators

A perturbation theory of the static response of insulating crystals to homogeneous electric fields, that combines the modern theory of polarization (MTP) with the variation-perturbation framework is developed, at unrestricted order of perturbation. First, we address conceptual issues related to the definition of such a perturbative approach. In particular, in our definition of an electric-field-dependent energy functional for periodic systems, the position operator appearing in the perturbation term is replaced by a Berry-phase expression, along the lines of the MTP. Moreover, due to the unbound nature of the perturbation, a regularization of the Berry-phase expression for the polarization is needed in order to define a numerically-stable variational procedure. Regularization is achieved by means of discretization, which can be performed either before or after the perturbation expansion. We compare the two possibilities and apply them to a model tight-binding Hamiltonian. Lowest-order as well as generic formulas are presented for the derivatives of the total energy, the normalization condition, the eigenequation, and the Lagrange parameters.Comment: 52 pages + 4 figures; accepted for publication in Physical Review

An integrated python-based open-source Digital Image Correlation Software for in-plane and out-of-plane measurements (Part 2)

Funding Information: The authors would like to acknowledge Fundação para a Ciência e a Tecnologia (FCT-MCTES) throughout the project PTDC/EMD-EMD/1230/2021 (AneurysmTool) and UIDB/00667/2020 (UNIDEMI) and the support provided by the Brazilian Government funding agencies CAPES, Brazil , FAPERJ, Brazil and CNPq, Brazil . Publisher Copyright: © 2022 The AuthorsThis work presents an out-of-the-box python-based open-source 3D Digital Image Correlation (3D-DIC) software for both in-plane and out-of-plane full-field measurements, denoted by iCorrVision-3D. The software includes an integrated stereo grabber for image acquisition, stereo calibration, numerical stereo correlation and post-processing modules. The main objective is to provide a complete integrated 3D-DIC system for users. All important DIC setting parameters can be easily controlled by the user from an intuitive graphical interface. For instance, the interpolation strategy and correlation techniques that are usually not open for users are available for modifications in iCorrVision-3D. The proposed software can be used in a great number of applications in engineering. Results indicated that the iCorrVision-3D software is robust and accurate in reconstructing the 3D shape of objects and in evaluating the out-of-plane full-field displacement of specimens being tested.publishersversionpublishe

Waist-to-height ratio is independently related to whole and central body fat, regardless of the waist circumference measurement protocol, in non-alcoholic fatty liver disease patients

This is the peer reviewed version of the following article: Pimenta N.M., Cortez-Pinto H., Melo X., Silva-Nunes J., Sardinha L.B. & Santa-Clara H. (2017) Waist-to-height ratio is independently related to whole and central body fat, regardless of the waist circumference measurement protocol, in non-alcoholic fatty liver disease patients. J Hum Nutr Diet. 30, 185–192, which has been published in final form atdoi: 10.1111/jhn.12410. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: Waist-to-height ratio (WHtR) has been reported as a prefer-able risk related body fat (BF) marker, although no standardised waistcircumference measurement protocol (WCmp) has been proposed. Thepresent study aimed to investigate whether the use of a different WCmpaffects the strength of relationship between WHtR and both whole andcentral BF in non-alcoholic fatty liver disease (NAFLD) patients.Methods: BF was assessed with dual energy X-ray absorptiometry (DXA) in28 NAFLD patients [19 males, mean (SD) 51 (13) years and nine females,47 (13) years]. All subjects also underwent anthropometric evaluationincluding height and waist circumference (WC) measurement using fourdifferent WCmp (WC1, minimal waist; WC2, iliac crest; WC3, mid-distancebetween iliac crest and lowest rib; WC4, at the umbilicus) and WHtR wascalculated using each WC measurements (WHtR1, WHtR2, WHtR3 andWHtR4, respectively). Partial correlations were conducted to assess the rela-tion of WHtR and DXA assessed BF.Results: All WHtR were particularly correlated with central BF, includingabdominal BF (r = 0.80, r = 0.84, r = 0.84 and r = 0.78, respectively, forWHtR1, WHtR2, WHtR3 and WHtR4) and central abdominal BF (r = 0.72,r = 0.77, r = 0.76 and r = 0.71, respectively, for WHtR1, WHtR2, WHtR3and WHtR4), after controlling for age, sex and body mass index. There wereno differences between the correlation coefficients obtained between allstudied WHtR and each whole and central BF variable.Conclusions: Waist-to-height ratio was found a suitable BF marker in thepresent sample of NAFLD patients and the strength of the relationshipbetween WHtR and both whole and central BF was not altered by usingdifferent WCmp in the present sample of NAFLD patients.FUNDING SOURCES The first author of this paper was supported by a research grant (PhD scholarship) from the Foundation for Science and Technology (FCT), Ministry of Education and Science of Portugal (grant: SFRH/ BD/ 70515/ 2010). The present study was funded by: the Centre for the Study of Human Performance, Portuguese Foundation for Science and Technology, Lisbon, Portugal.info:eu-repo/semantics/publishedVersio

Emotional competence of the nurse: the significance of the construct

Nas últimas décadas a incidência dos estudos sobre a temática das emoções na enfermagem centrou-se, sobretudo, na experiência emocional dos doentes e dos enfermeiros, deixando espaço para o foco da competência emocional do enfermeiro. Considerando que o contexto de fim de vida é repleto de sentimentos, sensações e emoções difíceis de gerir pelos enfermeiros, tornou-se fundamental significar os cenários emocionais importantes na prestação de cuidados de conforto durante essa fase do ciclo de vida. A finalidade deste estudo é contribuir para a clarificação do significado do desenvolvimento de competências emocionais no agir profissional do enfermeiro, assumindo como centro de interesse o contexto da prestação de cuidados de conforto à pessoa internada em unidade de cuidados paliativos. Considerando o problema e os objetivos em estudo, optou-se por um referencial metodológico de natureza qualitativa, com carácter descritivo e exploratório. Os sujeitos em análise são enfermeiros e pessoas que vivenciam o fim de vida, e que aceitaram participar no estudo através de entrevista semiestruturada, tendo sido assegurados e protegidos os procedimentos éticos inerentes. Para a análise do fenómeno em estudo, analisaram-se os dados usando a análise crítica do discurso de Fairclough. Do estudo emergiu o constructo da ‘competência emocional do enfermeiro’, como sendo um conjunto de capacidades que permitem conhecer, regular, atingir e gerir fenómenos emocionais de modo a construir e manter relações interpessoais em ambiente afetivo, o qual se enforma em torno de cinco dimensões, e se transforma igualmente em cinco capacidades

Waist circumference in Liver Disease

Background Central fat accumulation is important in Non-alcoholic Fatty Liver Disease (NAFLD) etiology. It is unknown weather any commonly used waist circumference (WC) measurement protocol (mp), as whole and central fat accumulation marker, is preferable for patients with NAFLD. The present study sought to find a preferable WC mp to be used in patients with NAFLD, based on three-fold criterion. Material and methods Body fat (BF) was assessed through Dual Energy X-ray Absorptiometry (DXA) in 28 patients with NAFLD (19 males, 51 + 13 yrs, and 9 females, 47 + 13 yrs). WC was measured using four different WC mp (WC1-narrowest torso, WC2- just above iliac crest, WC3- mid-distance between iliac crest and last rib and WC4- at the umbilicus). Results All WC measurements were highly correlated particularly with central BF depots, including trunk BF (r=0.78; r=0.82; r=0.82; r=0.84; respectively for WC1, WC2, WC3 and WC4) abdominal BF (r=0.78; r=0.78; r=0.80; r=0.72; respectively for WC1, WC2, WC3 and WC4) and central abdominal BF (r=0.76; r=0.77; r=0.78; r=0.68; respectively for WC1, WC2, WC3 and WC4), controlling for age, sex and body mass index. There were no differences between the correlation coefficients obtained between all studied WC measurements and each whole and central analyzed BF variable. Conclusion All studied WC mp seem suitable for use in patients with NAFLD, particularly as central BF clinical assessment tool, though not interchangeably. Hence biological and precision criteria alone did not sanction the superiority of any WC mp. Practical criteria may endorse WC measured at the iliac crest.info:eu-repo/semantics/publishedVersio

Waist-to-Hip Ratio is Related to Body Fat Content and Distribution Regardless of the Waist Circumference Measurement Protocol, in Non-Alcoholic Fatty Liver Disease Patients

Central accumulation and distribution of body fat (BF) is an important cardiometabolic risk factor. Waist-to-hip ratio (WHR), commonly elevated in non-alcoholic fatty liver disease (NAFLD) patients, has been endorsed as a risk related marker of central BF content and distribution, but no standardized waist circumference measurement protocol (WCmp) has been proposed. We aimed to investigate whether using different WCmp affects the strength of association between WHR and BF content and distribution in NAFLD patients. BF was assessed with Dual Energy X-ray Absorptiometry (DXA) in 28 NAFLD patients (19 males, 51 ± 13 yrs, and 9 females, 47 ± 13 yrs). Waist circumference (WC) was measured using four different WCmp (WC1: minimal waist; WC2: iliac crest; WC3: mid-distance between iliac crest and lowest rib; WC4: at the umbilicus) and WHR was calculated accordingly (WHR1, WHR2, WHR3 and WHR4, respectively). High WHR was found in up to 84.6% of subjects, depending on the WHR considered. With the exception of WHR1, all WHR correlated well with abdominal BF (r=0.47 for WHR1; r=0.59 for WHR2 and WHR3; r=0.58 for WHR4) and BF distribution (r=0.45 for WHR1; r=0.56 for WHR2 and WHR3; r=0.51 for WHR4), controlling for age, sex and body mass index (BMI). WHR2 and WHR3 diagnosed exactly the same prevalence of high WHR (76.9%). The present study confirms the strong relation between WHR and central BF, regardless of WCmp used, in NAFLD patients. WHR2 and WHR3 seemed preferable for use in clinical practice, interchangeably, for the diagnosis of high WHR in NAFLD patients.co-financed by national funds through the Programa Operacional do Alentejo (ALENT-07-0262-FEDER-001883)info:eu-repo/semantics/publishedVersio

Recurring Goals and Learning: The Impact of Successful Reward Attainment on Purchase Behavior

People often strive for an identical goal (e.g., rewards offered in loyalty programs), what we refer to as recurring goals. Extant research has documented post-reward resetting i.e., a slowdown in the inter-purchase time between earning the first reward and making the first purchase toward the second reward. This research shows how consumers do not reset fully; the inter-purchase time increases after a successful completion, but it does not increase to its previous level. Partial post-reward resetting occurs because people learn about their own ability to reach the reward. Hence, successful completions increase subsequent engagements, purchase rates, and task completion

The Equality Case of the Kraft and the Kraft-McMillan Inequalities

In this thesis, we analyze the Kraft Inequality and the Kraft-McMillan Inequality in their equality cases. Kraft’s Inequality deals with prefix-free code and Kraft-McMillan’s Inequality deals with uniquely decodable codes. The focus of the Kraft Inequality analysis is to study the occurrence of prefix-free codes that satisfy the equality case and the structure of words in the code when the equality condition is met. The second part of the thesis touches on the Kraft-McMillan Inequality. Since the proof of this latter inequality uses limits, we cannot immediately analyse its equality cases. The paper will therefore study the equality cases of this theorem and demonstrate that these equality cases have similar results to that of the Kraft Inequality, although it is necessary to prove them in a different way since the latter theorem’s proof is less direct

Tendências de pesquisa em informação e tecnologia: análise do GT 8 no Encontro Nacional de Pesquisa e Pós-Graduação em Ciência da Informação

Over the years, information and technologies have been more and more impact in the activities of scientific production. The objective of the present work is to analyze the evolution of the main themes that are discussed in the WG 8 of ANCIB from 2008 to 2015 and to trace research tendencies in this WG. The study emerged from the need to know how the research themes discussed in the WG 8 have evolved, from its creation to the present day. The adopted methodological procedures were characterized as an exploratory and descriptive study, with qualitative approach, which was constituted by means of a detailed survey in the annals of ENANCIB. From the developed analysis, they were verified, by means of the approached themes, tendencies in the research ambit of Information Science in the communications of ANCIB, precisely in the WG 8 of ENANCIB. Among the presentation techniques, they were adopted tag clouds in the visualization of results. The results indicate that during all the trajectory of the studied WG, there was production about the highlighted theme, indicating that it should remain active. Among the research themes, the category of Information Architecture was featured, once it has the biggest number of occurrences published in the WG 8 during the studied period. This way, it is understood that it is configures as a research tendency.No decorrer dos anos, o avanço tecnológico e o uso intenso da informação e das tecnologias tem impactado nas atividades de produção científica. O objetivo deste trabalho é analisar a evolução das principais temáticas discutidas no GT 8 da ANCIB, no período de 2008 a 2015, e traçar tendências de pesquisa no GT. O estudo surge pela necessidade de saber como evoluem as temáticas de pesquisa discutidas no GT8, desde sua criação até os dias atuais. Os procedimentos metodológicos adotados foram caracterizados por um estudo descritivo e exploratório com abordagem quantitativa, constituindose por meio de um levantamento detalhado dos anais do ENANCIB. A partir das análises que foram realizadas, verificamos, pelas temáticas abordadas, tendências no âmbito da pesquisa em Ciência da Informação nas comunicações da ANCIB, no interior do GT8 do ENANCIB. Foram adotadas entre as técnicas de apresentação, as nuvens de tags para visualização dos resultados. Os resultados indicam que durante todo o percurso do GT, houve produção da temática destacada, indicando que ela deve permanecer ativa. Entre as temáticas de pesquisa, a categoria Arquitetura da Informação teve destaque abrigando o maior numero de ocorrências publicados no GT 8 durante o período em estudo, entendemos que assim, se configura como tendência de pesquisa