Future dynamics in f(R) theories

The $f(R)$ gravity theories provide an alternative way to explain the current cosmic acceleration without invoking dark energy matter component. However, the freedom in the choice of the functional forms of $f(R)$ gives rise to the problem of how to constrain and break the degeneracy among these gravity theories on theoretical and/or observational grounds. In this paper to proceed further with the investigation on the potentialities, difficulties and limitations of $f(R)$ gravity, we examine the question as to whether the future dynamics can be used to break the degeneracy between $f(R)$ gravity theories by investigating the future dynamics of spatially homogeneous and isotropic dust flat models in two $f(R)$ gravity theories, namely the well known $f(R) = R + \alpha R^{n}$ gravity and another by A. Aviles et al., whose motivation comes from the cosmographic approach to $f(R)$ gravity. To this end we perform a detailed numerical study of the future dynamic of these flat model in these theories taking into account the recent constraints on the cosmological parameters made by the Planck team. We show that besides being powerful for discriminating between $f(R)$ gravity theories, the future dynamics technique can also be used to determine the fate of the Universe in the framework of these $f(R)$ gravity theories. Moreover, there emerges from our numerical analysis that if we do not invoke a dark energy component with equation-of-state parameter $\omega < -1$ one still has dust flat FLRW solution with a big rip, if gravity deviates from general relativity via $f(R) = R + \alpha R^n$. We also show that FLRW dust solutions with $f''<0$ do not necessarily lead to singularity.Comment: 12 pages, 8 figures. V2: Generality and implications of the results are emphasized, connection with the recent literature improved, typos corrected, references adde

Zygosaccharomyces bailii strain talf1 inulinases: a versatile tool for bioprocesses

Fructans are one of the most abundant non-structural polysaccharides found in a wide range of plants. Inulin is a polydisperse fructan polymer composed by linear chains of b-2, 1-linked D-fructofuranose molecules terminated by a glucose residue through a sucrose-type linkage at the reducing end. Inulin or inulin-rich materials can be actively hydrolyzed into fermentable sugars (glucose and fructose) using inulinases and then further used within bioprocesses

Diagnosing numerical Cherenkov instabilities in relativistic plasma simulations based on general meshes

Numerical Cherenkov radiation (NCR) or instability is a detrimental effect frequently found in electromagnetic particle-in-cell (EM-PIC) simulations involving relativistic plasma beams. NCR is caused by spurious coupling between electromagnetic-field modes and multiple beam resonances. This coupling may result from the slow down of poorly-resolved waves due to numerical (grid) dispersion and from aliasing mechanisms. NCR has been studied in the past for finite-difference-based EM-PIC algorithms on regular (structured) meshes with rectangular elements. In this work, we extend the analysis of NCR to finite-element-based EM-PIC algorithms implemented on unstructured meshes. The influence of different mesh element shapes and mesh layouts on NCR is studied. Analytic predictions are compared against results from finite-element-based EM-PIC simulations of relativistic plasma beams on various mesh types.Comment: 31 pages, 20 figure

Food safety as a field in supply chain management studies: a systematic literature review.

The increasing number of food contamination events has called the attention of both practitioners and scholars to food safety problems and their consequences. Many of these events are related to the supply chain because food production is now a global process of commoditized goods, made by large corporations that purchase inputs from producers in many countries. Given the linkage between supply chain and food safety issues, we investigated how studies in the supply chain management area have examined food safety issues, exploring some of their important characteristics. To do so, we conducted a systematic literature review of 46 papers, published in 23 journals, indexed in the Web of Science database. As a result, we pointed out some main characteristics of these papers, including journal attributes, authorship data, citation network, methodological characteristics, and theoretical approaches. Results serve as a reference to scholars and allow us to discuss some potential opportunities for future research in the field of food safety in the supply chain management area. Keywords: supply chain management, food safety, systematic literature review. JEL code: M11, L66, L23, Q56, M1

"EXPERIMENTAÇÕES EM CLINICA DA ATIVIDADE: CARTOGRAFIA NA ESCOLA".

RESUMO Neste estudo afirmamos uma Psicologia do Trabalho comprometida em potencializar a construção de outros modos de trabalhar que ampliem a vida. Seguimos a direção de construir possíveis formas de pesquisar que buscam favorecer a criação de novos mundos no trabalho, ampliando o poder de ação dos trabalhadores sobre seu próprio trabalho. As questões aqui levantadas foram disparadas a partir de uma experimentação em análise do trabalho docente construída junto com professores de uma escola pública do município de Vitória/ES. Trata-se de uma pesquisa-intervenção que toma como princípio que analisar o trabalho não se limita a quadros analíticos construídos a partir de um distanciamento da complexidade engendrada onde o trabalho acontece. Como estratégia para transformarcompreender as relações que envolvem trabalho e educação, propomos uma direção metodológica de pesquisa que articula investigação e intervenção na direção do diálogo, da interlocução entre os diferentes saberes com o objetivo de potencializar estratégias utilizadas pelos trabalhadores para lidar com a variabilidade das situações de trabalho. Com esse objetivo ousamos produzir novas conexões entre saberes-fazeres no campo da Psicologia do Trabalho em nossa busca por novos caminhos. Trazemos a contribuição da Clínica da Atividade como importante ferramenta metodológica para pensar a questão da atividade e da subjetividade no trabalho, articulando-a à uma concepção de clínica como clinamen, o que nos permitiu apostar na afirmação da potência criativa dos próprios trabalhadores para transformarem sua atividade. Assim, nos lançamos no desafio de cartografar essa experiência a fim de buscar novos sentidos que pudessem se constituir como possíveis acerca da atividade docente. Nossas análises se realizaram em conjunto com um grupo de professores, na experimentação de um dispositivo em forma de Oficina de Fotos, partindo desta experiência compartilhada, na qual conhecer e transformar já não se diferenciam. Acreditamos que a análise da atividade docente realizada funcionou como uma possibilidade de intervenção clínica que se constitui como uma aposta para a produção de outras práticas em Psicologia do Trabalho

Structural and functional stabilization of protein entities

XI Reunião Regional Nordeste da SBBq | 4th International Symposium in Biochemistry of Macromolecules and BiotechnologyStabilization of protein and protein-like molecules translates into preservation of both structure and functionality during storage and/or targeting, and such stabilization is mostly attained through establishment of a thermodynamic equilibrium with the (micro)environment. The basic thermodynamic principles that govern protein structural transitions and the interactions of the protein and/or peptide molecule with its (micro)environment will, therefore, be tackled. Protein stabilization is based upon dampening the molecular motions and, therefore, eliminating conformational transitions while the molecule is still in the native 3D (folded) state. The 3D structure of a protein molecule depends mostly on two types of interactions: intramolecular interactions between aminoacid moieties and intermolecular interactions with solute and/or solvent molecules present in its microenvironment. Stabilizing a biomolecule (aiming at preserving its function) involves dampening its molecular motions, and this can be achieved by reducing the chemical activity of the water present in its microenvironment, thus stabilizing both its structure and functionality. Recently, the simultaneous entrapment-stabilization of proteins and enzymes based on nanoencapsulation in a nanoemulsion (W/O/W) matrix with an hydrophilic core has started to gain momentum. Similarly to the stabilization mechanism of osmolytes, in nanoencapsulation the water activity is altered thus affecting the molecular motions of the proteins. Highlights will also be given to structural and functional stabilization of protein entities (viz. enzymes, (macro)peptides, (recombinant) proteins, and bacteriophages) by chemical methodologies. Modification of the biomolecules microenvironment via multipoint covalent attachment onto a solid surface followed by hydrophylic polymer coimmobilization, are some of the (latest) strategies that will be discussed.info:eu-repo/semantics/publishedVersio

Danos de lagartas de Elasmopalpus lignosellus no feijoeiro.

Elasmopalpus lignosellus (Zeller), conhecida como lagarta elasmo, é considerada uma das principais pragas de diversas culturas, causando danos elevados no feijoeiro em períodos de estiagem. Foi avaliado nesse trabalho o dano da lagarta de diferentes idades no feijoeiro no estágio de folhas primárias: 1) lagartas de um dia; 2) lagartas de três dias; 3) lagartas de cinco dias; 4) lagartas de sete dias; 5) lagartas de nove dias; 6) testemunha (sem inseto).Resumo