Dynamical demixing of a binary mixture under sedimentation

We investigate the sedimentation dynamics of a binary mixture, the species of which differ by their Stokes coefficients but are identical otherwise. We analyze the sedimentation dynamics and the morphology of the final deposits using Brownian dynamics simulations for mixtures with a range of sedimentation velocities of both species. We found a threshold in the sedimentation velocities difference above which the species in the final deposit are segregated. The degree of segregation increases with the difference in the Stokes coefficients or the sedimentation velocities above the threshold. We propose a simple mean-field model that captures the main features of the simulated deposits

Enhanced propagation of motile bacteria on surfaces due to forward scattering

How motile bacteria move near a surface is a problem of fundamental biophysical interest and is key to the emergence of several phenomena of biological, ecological and medical relevance, including biofilm formation. Solid boundaries can strongly influence a cell's propulsion mechanism, thus leading many flagellated bacteria to describe long circular trajectories stably entrapped by the surface. Experimental studies on near-surface bacterial motility have, however, neglected the fact that real environments have typical microstructures varying on the scale of the cells' motion. Here, we show that micro-obstacles influence the propagation of peritrichously flagellated bacteria on a flat surface in a non-monotonic way. Instead of hindering it, an optimal, relatively low obstacle density can significantly enhance cells' propagation on surfaces due to individual forward-scattering events. This finding provides insight on the emerging dynamics of chiral active matter in complex environments and inspires possible routes to control microbial ecology in natural habitats

Board's diversity and the recognition of integrated reports: Are they related?

This paper investigates the influence of Board of Directors’ diversity on the external reputation of highly Integrated Reports, using a set of international entities. Globalization and competitive environment lead companies to diversify their responsibilities to stakeholders and to the society as a whole. Notwithstanding the need to prepare reports to providers of capital, companies currently must report to a broader audience than shareholders, capturing the attention of several categories of stakeholders. They want to know why, where and how companies create and add value, and how they deal with responsibility and sustainability issues. While an increasingly number of entities are disclosing sustainability and corporate social responsibility (CSR) information, there is still little connection between such information, financial information, performance and value creation strategy. This gap has been over debate, and Integrated Reporting () has emerged. Still voluntary in almost all the world, it is indeed gradually encouraged and supported by regulators, institutional investors and organizations, as an innovative nature in promoting a holistic and integrated vision of the company, where the Board of Directors must play an important role (defining strategies, promoting policies and implementing best practices). The main issue we address is whether different characteristics of Directors seated on the Board impact on the external decision to consider the Integrated Report of that company as a Recognized, instead of a Regular one. Differences between Reference and Regular are supported in the attribution of a premium by external parties, or on the independent recommendation to serve as benchmark. Our sample includes 377 entities all over the world identified as preparers, from whom people expect to be accountable for the transparency of their external communication process. Main findings reveal that while the role duality of the CEO has a negative influence, the board size, the independence of the board and the gender diversity are positively contributing to the diffusion of integrated reports of higher recognition, and Experience is not statistical significant. The results are maintained when institutional characteristics of the countries are included.info:eu-repo/semantics/publishedVersio

The relationship between board’s diversity and the reputation of integrated reports

The integrated reporting arises as an answer to the insufficiency of traditional financial report and the emergent need to disclose non-financial information to stakeholders, and it is proposed by the International Integrated Reporting Council. Given the influence of corporate governance on corporate disclosure and the key role of the companies’ board of directors in managing the disclosure of a wide range of information, the present study aims to analyze how some corporate governance characteristics may influence the reputation of integrated reports, distinguishing between reference reports and regular reports. The sample of this study comprises 374 reporters extracted from the IIRC Examples Database. The results show that the size and the experience of the board of directors does not influence the reputation of the integrated reports. In turn, the independence of the board and gender diversity influence positively the reputation of integrated reports, while role duality seems to influence negatively.info:eu-repo/semantics/publishedVersio

Epidemiology of respiratory viruses in a pediatric department with real-time PCR

info:eu-repo/semantics/publishedVersio

Avaliação de acessos de melancia (Citrullus lanatus) do Banco Ativo de Germoplasma (BAG) de cucurbitáceas da Embrapa Semi-Árido.

Avaliou-se o número de dias para o aparecimento da primeira flor feminina

Adubação nitrogenada no feijoeiro cultivado sob palhadas de diferentes culturas.

O objetivo deste trabalho é avaliar a resposta do feijoeiro irrigado, cultivado sob plantio direto em sucessão a diferentes culturas, à adubação nitrogenada em cobertura.bitstream/CNPAF-2009-09/27950/1/comt_159.pd