The physics of dynamical atomic charges: the case of ABO3 compounds

Based on recent first-principles computations in perovskite compounds, especially BaTiO3, we examine the significance of the Born effective charge concept and contrast it with other atomic charge definitions, either static (Mulliken, Bader...) or dynamical (Callen, Szigeti...). It is shown that static and dynamical charges are not driven by the same underlying parameters. A unified treatment of dynamical charges in periodic solids and large clusters is proposed. The origin of the difference between static and dynamical charges is discussed in terms of local polarizability and delocalized transfers of charge: local models succeed in reproducing anomalous effective charges thanks to large atomic polarizabilities but, in ABO3 compounds, ab initio calculations favor the physical picture based upon transfer of charges. Various results concerning barium and strontium titanates are presented. The origin of anomalous Born effective charges is discussed thanks to a band-by-band decomposition which allows to identify the displacement of the Wannier center of separated bands induced by an atomic displacement. The sensitivity of the Born effective charges to microscopic and macroscopic strains is examined. Finally, we estimate the spontaneous polarization in the four phases of barium titanate.Comment: 25 pages, 6 Figures, 10 Tables, LaTe

Análise de atitudes de alunos universitários em relação à estatística por meio da Teoria da Resposta ao Item (TRI)

Pesquisas têm indicado que alunos demonstram: 1) dificuldade de aprendizado dos conceitos estatísticos e 2) baixa motivação em utilizar ferramentas estatísticas em situações presentes e futuras. Estudos realizados no campo educacional dizem que um estudante com atitudes positivas sobre determinada matéria apresenta maior probabilidade de sucesso na aprendizagem dos conteúdos desta. O presente trabalho avaliou as atitudes em relação à estatística de 360 alunos de uma universidade particular, que responderam a Escala de Atitudes em relação à Estatística (EAE). As respostas foram analisadas por meio da Teoria Clássica dos Testes e pela Teoria da Resposta ao Item. Os resultados da classificação das atitudes, em positivas ou negativas, encontradas por escores brutos e por escores latentes, foram fortemente concordantes (Kappa = 0,87). A escala apresentou boa consistência interna nas duas análises, com Alfa de Cronbach de 0,95 e com parâmetro de discriminação dos itens (ai) variando de moderado a alto. Os alunos apresentaram atitudes mais desfavoráveis do que favoráveis.Os parâmetros de dificuldade dos itens (bi) mostraram que a proposição de mais fácil concordância por parte dos alunos foi referente à tensão sentida pelos mesmos durante as aulas de estatística. As variáveis que mostraram influenciar no nível de atitudes foram: área de estudo, auto-percepção de desempenho na disciplina e reconhecimento da aplicabilidade da estatística. Esses resultados sugerem que sejam adotadas estratégias para desenvolvimento de um ambiente de ensino-aprendizado estimulante, agradável, e que reforce as aplicações da Estatística no contexto do curso de cada estudante.Research has shown that students demonstrate: 1) difficulties in learning statistical concepts, and 2) low motivation to use statistical tools in present and future situations. Studies in the Education field point out that a student with positive attitudes on a subject is more likely to succeed in learning the contents. The present study assessed attitudes of 360 students toward Statistics at a private university. The students answered to the Scale of Attitudes towards Statistics. Answers were analyzed using the Classical Test Theory and the Item Response Theory. The results for the Scale of Attitudes – for positive or negative attitude – demonstrate that both raw and latent scores are strongly concordant (Kappa = 0. 87). The Scale of Attitudes presented a good internal consistency in both analysis: Cronbach's Alpha = 0. 95 and discrimination parameter of the items (ai) of moderate to high. The students had more unfavorable than favorable attitudes. .The parameters of difficulty of the items (bi) showed that the proposition of easy agreement on the part of students was on the tension felt during statistical classes. The variables that showed influence the level of attitudes were: area of study, self-perception of performance in the discipline and the applicability of statistics. These results suggest that strategies should be taken to develop an enjoyable and exciting teaching and learning environment, and that the applications of Statistics must be highlighted in the context of the course of each student

Distúrbios de saúde relacionados ao aprendizado de solda: avaliação de abordagem para comunicação de risco

OBJETIVO: evaluar la identificación de disturbios de salud auto-referidos por aprendices de soldadura y analizar la intensidad de la relación entre edad y tiempo de experiencia con los disturbios de salud auto-referidos por los aprendices antes y después de la intervención socioambiental de enfermería. MÉTODO: se trata de estudio casi experimental, no aleatorio, del tipo antes y después, realizado con 86 aprendices de soldadura de una entidad privada. RESULTADOS: los resultados muestran diferencia significativa para la diferencia de los promedios pre y post-prueba y aumento del promedio post-prueba para el sistema cardiovascular, respiratorio y tegumentario. También, hubo correlación negativa de la edad de los aprendices de soldadura con la identificación de disturbios de salud. CONCLUSIÓN: la intervención socioambiental de enfermería proporcionó informaciones de salud sobre los disturbios de salud relacionados con la actividad de soldadura. Esas informaciones posibilitaron a los aprendices evaluar las informaciones y mediante estas, auto-referir disturbios de salud.OBJETIVO: avaliar a identificação de distúrbios de saúde autorreferidos por aprendizes de solda e analisar a intensidade da relação entre idade e tempo de experiência com os distúrbios de saúde autorreferidos pelos aprendizes, antes e depois da intervenção socioambiental de enfermagem. MÉTODO: trata-se de estudo quase-experimental, não randomizado, do tipo antes e depois, realizado com 86 aprendizes de solda de entidade privada. RESULTADOS: os resultados mostram diferença significativa para a diferença das médias pré e pós-teste e aumento da média pós-teste para o sistema cardiovascular, respiratório e tegumentar. Ainda, houve correlação negativa da idade dos aprendizes de solda com a identificação de distúrbios de saúde. CONCLUSÃO: a intervenção socioambiental de enfermagem propiciou informações de saúde sobre os distúrbios de saúde relacionados à atividade de solda. Tais informações possibilitaram aos aprendizes avaliar as informações e, mediante essas, autorreferir distúrbios de saúde.OBJECTIVE: to assess the identification of health disorders as self-reported by apprentices of welding and to analyze the strength of the relationship between age and time of experience with self-reported health disorders before and after a socio-environmental nursing intervention. METHOD: this quasi-experimental, non-randomized, before-and-after study was conducted with 86 welding apprentices from a private entity. RESULTS: the results show a significant difference for the pre- and post-test means and an increase in the post-test mean score for the cardiovascular, respiratory and cutaneous systems. There was also a negative correlation between the apprentices' ages and the identification of health disorders. CONCLUSION: the socio-environmental nursing intervention enabled obtaining information on health disorders related to welding. In turn, such information enabled the apprentices to assess information and self-report health disorders

Formation of critical thinking to overcome existential fears in people 15–17 years old as an element of sustainable behavior

Recently, due to the changing conditions of objective reality, the actualization of fears among the population has been growing. Highly intense fears interfere with the normal social life of the individual and can lead to its maladaptation, which can begin to manifest itself already in adolescence, when many stressful factors affect the personality, emotional and cognitive immaturity of the individual only increase the negative impact. In this regard, it is necessary to create an effective screening technique aimed at identifying the actual fears of the individual with an assessment of their intensity. To this end, we have proposed the author’s questionnaire “Features of actualization of existential fears of the individual”, the internal structure of which allows not only to identify fears, but to determine their intensity and need for psychological help. In order to ensure the adequacy of the integrative indicator “intensity of fear”, determined by the author’s questionnaire, the data were compared with the results obtained using the methods “Life Satisfaction Scale” and “Death Anxiety Scale”. We also associate an increase in the intensity of fears, their impact on the quality of life, the appearance of somatovegetative reactions in fear with a number of personal characteristics of the individual, including critical thinking, as an important cognitive property of the individual

Влияние эмоциональной сферы на актуализацию и интенсивность экзистенциальных страхов

Introduction. The article addresses the problem of increasing existential fears, their growing prevalence and intensity among the population due to changes in objective reality associated with the deterioration of the social, ecological, and political situation in the country and the world. Despite numerous studies devoted to fears, the age-related characteristics of experiencing existential fears and their connection with psycho-emotional states remain insufficiently studied.Methods. The sample included 317 respondents. The first group consisted of respondents aged 15–17, the second group of respondents aged 20–25, and the third group of respondents aged 30–45. We examined the prevalence and intensity of fears in three age groups, taking into account gender, using the authors\u27 questionnaire, "Features of the Actualization of Existential Fears in Individuals". We also assessed the levels of personal anxiety and depression using the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI). The Mann-Whitney U-test was used to confirm the reliability of differences between subgroups of respondents, and Spearman\u27s rank correlation coefficient was used to confirm relationships between variables.Results. Fears were present in all participants, with intense fears being more common among women regardless of age group. The older age group showed a decrease in the frequency of high-intensity fears compared to the younger groups, regardless of gender. Additionally, direct significant correlations were found between the intensity of fears and the increase in anxiety and depression levels in all participants, regardless of age.Discussion. The data suggest that a person\u27s psycho-emotional status influences how they experience fears, with an increase in their intensity, regardless of age and gender. Since high-intensity fears can lead to disruptions in normal adaptation and socialization, it seems necessary to create a program aimed at overcoming fears, taking into account certain psychological characteristics of the individual, including their emotional sphere (personal anxiety and depression).Введение. В статье рассматривается проблема усиления экзистенциальных страхов, увеличения их распространённости и интенсивности среди населения из-за изменений в объективной реальности, связанных с ухудшением социальной, экологической и политической обстановки в стране и мире. Несмотря на множество исследований, посвящённых страхам, возрастные особенности переживания экзистенциальных страхов и их связь с психоэмоциональным состоянием изучены недостаточно. Методы. В выборку респондентов вошли 317 человек, первая группа состояла из респондентов в возрасте 15–17 лет, вторая — из респондентов 20–25 лет, третья — из респондентов 30–45 лет. Мы изучили распространённость и интенсивность страхов в трёх возрастных группах с учётом пола участников, используя авторскую анкету-опросник «Особенности актуализации экзистенциальных страхов личности», а также оценили уровень личностной тревожности и депрессии с помощью методик «Шкала депрессии Бека» (Beck Depression Inventory и «Шкала тревоги Спилбергера» (State-Trait Anxiety Inventory - STAI). Для подтверждения достоверности различий между подгруппами респондентов использовался U-критерий Манна-Уитни, для подтверждения связей между переменными - коэффициент ранговой корреляции Спирмена. Результаты. Страхи свойственны всем участникам исследования, а интенсивные страхи распространены и чаще встречаются у женщин независимо от возрастной группы. У респондентов старшей возрастной группы отмечено снижение частоты страхов высокой интенсивности по сравнению с младшими группами вне зависимости от пола. Также обнаружены прямые достоверные связи между интенсивностью страхов и ростом показателей тревожности и депрессии у всех участников независимо от возраста. Обсуждение результатов. Полученные данные свидетельствуют о влиянии психоэмоционального статуса личности на особенности переживания страхов с усилением их интенсивности, вне зависимости от возраста и пола. Так как страхи высокой интенсивности могут приводить к нарушению нормальной адаптации и социализации личности, представляется необходимым создание программы, направленной на преодоление страхов с учетом определенных психологических особенностей индивида, включающих эмоциональную сферу (личностную тревожность и депрессию)

Damage Control: The Untold Story of Venereal Disease in Hamilton, 1900-1950

Venereal disease, now known as sexually-transmitted disease, has a long history of association with humanity. Syphilis, in particular, has attracted enormous debate and controversy ever since the fifteenth century when it erupted in epidemic form in Naples, Italy. This controversy continues not only because there are unresolved questions about where and when syphilis emerged (Powell and Cook 2005), but also because shifting attitudes, perceptions and values toward sexuality affect medical practice, social behaviour, public health practices and the experiences of people afflicted with it (Brandt 1987). This was certainly the case in early twentieth century Canada, the period within which this book is set. The shocking revelation in 1914 that the Canadian Expeditionary Force had the highest level of venereal disease of all the militaryunits serving in Europe was met with surprise, disgust and fear (Cassel 1987). At the time, venereal disease symbolized corrupt sexuality and was understood to be a sign of moral pollution, filth, and disordered sexual practice (Brandt 1987). How could such a disturbing situation have arisen in Canadian society? What did it signal about the state of morality, personal character, and the social order? Who was to blame for this hidden epidemic: irresponsible individuals or deplorable social conditions? What did the unexpectedly high prevalence of diseases transmitted through sexual behaviour mean for the future of the fledgling country? How could the damage wrought by venereal disease be prevented, controlled and cured? Damage Control takes up these questions and tells the untold story of how venereal disease, particularly syphilis, was experienced and understood in Hamilton, Ontario from World War I (WWI) to the mid-twentieth century. Written by fourth-year Honours Anthropology students studying infectious disease at McMaster University, this book is the product of a collaborative writing process. The authors brainstormed the subject matter of the book, then conducted in-depth research in archives in Hamilton and beyond to compile a rich set of newspapers, public health reports, images, and statistics which they shared through a university website. They made stimulating suggestions for each others’ chapters as the writing progressed from the germ of an idea to a fully-developed discussion. In short, everyone contributed to the entirety of the book in an exemplary demonstration of dedicated teamwork and commitment to the project.</p