The CECAM Electronic Structure Library and the modular software development paradigm

First-principles electronic structure calculations are very widely used thanks to the many successful software packages available. Their traditional coding paradigm is monolithic, i.e., regardless of how modular its internal structure may be, the code is built independently from others, from the compiler up, with the exception of linear-algebra and message-passing libraries. This model has been quite successful for decades. The rapid progress in methodology, however, has resulted in an ever increasing complexity of those programs, which implies a growing amount of replication in coding and in the recurrent re-engineering needed to adapt to evolving hardware architecture. The Electronic Structure Library (\esl) was initiated by CECAM (European Centre for Atomic and Molecular Calculations) to catalyze a paradigm shift away from the monolithic model and promote modularization, with the ambition to extract common tasks from electronic structure programs and redesign them as free, open-source libraries. They include ``heavy-duty'' ones with a high degree of parallelisation, and potential for adaptation to novel hardware within them, thereby separating the sophisticated computer science aspects of performance optimization and re-engineering from the computational science done by scientists when implementing new ideas. It is a community effort, undertaken by developers of various successful codes, now facing the challenges arising in the new model. This modular paradigm will improve overall coding efficiency and enable specialists (computer scientists or computational scientists) to use their skills more effectively. It will lead to a more sustainable and dynamic evolution of software as well as lower barriers to entry for new developers

Database-driven High-Throughput Calculations and Machine Learning Models for Materials Design

This paper reviews past and ongoing efforts in using high-throughput ab-inito calculations in combination with machine learning models for materials design. The primary focus is on bulk materials, i.e., materials with fixed, ordered, crystal structures, although the methods naturally extend into more complicated configurations. Efficient and robust computational methods, computational power, and reliable methods for automated database-driven high-throughput computation are combined to produce high-quality data sets. This data can be used to train machine learning models for predicting the stability of bulk materials and their properties. The underlying computational methods and the tools for automated calculations are discussed in some detail. Various machine learning models and, in particular, descriptors for general use in materials design are also covered.Comment: 19 pages, 2 figure

Dimensões da violência contra crianças e adolescentes, apreendidas do discurso de professoras e cuidadoras

Neste estudo exploratório-descritivo, com abordagem qualitativa, objetivou-se investigar a percepção de cuidadoras de uma Instituição de Educação Infantil e professoras de uma Escola de Ensino Fundamental acerca do conceito de violência, bem como a conduta por elas adotada, frente a situações de violência contra crianças e adolescentes. Os dados foram coletados em agosto de 2004, por meio de entrevista semi-estruturada, gravada e transcrita. Constatou-se que as informantes reconhecem violência tanto física quanto psicológica na interação família e crianças, bem como das crianças entre si e referem a negligência como forma de violência. Quanto à atuação das cuidadoras e professoras, percebeu-se a naturalização da violência. O estudo fornece subsídios para atuação de enfermagem frente a situações de violência contra criança e adolescente em instituições educacionais e apresenta a Consulta de Enfermagem como instrumento metodológico capaz de subsidiar as condutas a serem adotadas.The aim of this descriptive exploratory study based on a qualitative approach was to investigate the perception of caretakers of an Infantile Education Institution and of teachers of a Primary School regarding the concept of violence, as well as the conduct adopted by them in relation to violent situations against children and adolescents. The data were collected in August of 2004 through a semi-structured interview, which was recorded and subsequently transcribed. The ethical precepts of the Resolution 196/96 were followed. It was verified that the informants recognize physical and psychological violence in the interaction between family and children, as well as between children themselves, referring to negligence as a form of violence. As for the performance of the caretakers and teachers, a naturalization of violence was noticed. The study offers subsidies for nursing performance in relation to situations of violence against children and adolescents in educational institutions and presents the Nursing Consultation as a methodological instrument capable of subsidizing the conducts to be adopted.En este estudio exploratorio descriptivo, de tipo cualitativo, se tuvo como objetivo investigar la percepción de las cuidadoras de un jardin infantil y las profesoras de una escuela primária acerca del concepto de la violencia, así como de la conducta adoptada por estas, frente a las situaciones de violencias contra los niños y adolescentes. Los datos fueron recoletados en agosto del 2004 a través de la entrevista semi-estructurada. Se verificó que las participantes del estudio reconocen la violencia física y psicológica en la interacción entre la familia y los niños, así como entre los propios niños entre si y manifestan la negligencia como una forma de violencia. En cuanto a la actuación de las cuidadoras y las profesoras, se notó la naturalización de la violencia. El estudio proporciona los subsidios para la actuación de las enfermeras frente a las situaciones de violencias contra el niño y adolescente en las instituciones educativas y presenta la Consulta de Enfermería como el instrumento metodológico capaz de ajudar a las conductas a ser adoptadas

Potential pollinators of Comolia ovalifolia DC Triana (Melastomataceae) and Chamaecrista ramosa (Vog.) H.S. Irwin and Barneby var. ramosa (Leguminosae-Caesalpinioideae), in restinga, Bahia, Brazil

Comolia ovalifolia DC Triana (Melastomataceae) and Chamaecrista ramosa (Vog.) H.S. Irwin and Barneby var. ramosa (Leguminosae - Caesalpinioideae) are tropical plant species found in restinga (herbaceous-shrubby, sandy costal ecosystems). They have flowers with poricidal anthers and are pollinated by bees. The study sought to analyse potential pollinators of both plants during visits to their flowers in a restinga area in Bahia. The flowering displayed by both species was considered continuous and long duration, constantly providing pollen to floral visitors. C. ovalifolia was visited by 17 species of bees and C. ramosa by 16 species, predominantly from the Apidae family (with a similarity index of 74%). The behavior displayed by these visiting bees was of vibrating anthers. The small-sized Euglossa sp. Latreille, 1802 and Florilegus similis Urban, 1970 bees played less of a role as pollinators, since they rarely touched the flower stigma during harvests and were thus considered opportunist visitors or casual pollinators. Centris decolorata Lepetier, 1841 (= C. leprieuri) and Xylocopa subcyanea Perez, 1901 are large bees and were considered efficient pollinators of C. ovalifolia and C. ramosa because of the higher frequency and constancy of their visits, and their favourable behaviour and size for pollen transfer between flowers, which guarantees the survival of these native restinga plant species