Dynamics of Counterion Condensation

Using a generalization of the Poisson-Boltzmann equation, dynamics of counterion condensation is studied. For a single charged plate in the presence of counterions, it is shown that the approach to equilibrium is diffusive. In the far from equilibrium case of a moving charged plate, a dynamical counterion condensation transition occurs at a critical velocity. The complex dynamic behavior of the counterion cloud is shown to lead to a novel nonlinear force-velocity relation for the moving plate.Comment: 5 pages, 1 ps figure included using eps

Seletividade de herbicidas para a cultura do tomate para processamento industrial híbrido BRS Sena.

Objetivou-se com este trabalho avaliar a seletividade de herbicidas para a cultura do tomate para processamentoindustrial híbrido BRS Sena.Trabalho 1

Anisotropic elastic theory of preloaded granular media

A macroscopic elastic description of stresses in static, preloaded granular media is derived systematically from the microscopic elasticity of individual inter-grain contacts. The assumed preloaded state and friction at contacts ensure that the network of inter-grain contacts is not altered by small perturbations. The texture of this network, set by the preparation of the system, is encoded in second and fourth order fabric tensors. A small perturbation generates both normal and tangential inter-grain forces, the latter causing grains to reorient. This reorientation response and the incremental stress are expressed in terms of the macroscopic strain.Comment: 7 pages, 2 figures. Accepted version. [email protected] [email protected]

Controle de plantas infestantes em cultivo de tomate rasteiro para processamento industrial.

Trabalho 11

Exatidão de classificações automáticas de uma imagem LANDSAT 5 TM para a região cafeeira de Machado, MG.

O presente trabalho avalia a acurácia de dois classificadores automáticos disponíveis no Sistema de Informação Geográfica SPRING para o mapeamento de uso e ocupação da terra da região cafeeira de Machado, MG. Foram utilizados os classificadores: Battacharya, ?por região?; e o Máxima Verossimilhança (Maxver), ?pixel a pixel? para a imagem Landsat 5 TM e como referência foi utilizada a imagem do satélite Spot 4 classificada visualmente e validada em campo. Ambos algoritmos demonstraram baixo rendimento para a região. Posteriormente às classificações, foram criadas matrizes de erro, comparando as classificações automáticas com a visual. O desempenho das classificações foi avaliado pelos índices de exatidão Global, Kappa e Tau. O baixo desempenho das classificações pode ser explicado pela região cafeeira de Machado possuir um relevo muito movimentado, proporcionando regiões sombreadas e lavouras cafeeiras contíguas a fragmentos de vegetação nativa, os quais apresentam resposta espectral semelhante

Características físicas de pedúnculos de clones de cajueiro-anão (Anacardium occidentale L.) produzidos em função da variação ambiental e temporal.

Cashew apple physical quality variables include different external characteristics, such as appearance, size, color, shape, and firmness, among others, which are very important in commercialization because they are the first characteristics perceived by consumers, who usually buy what attracts them most. The objective of this study was to evaluate the influence of the region, production year and genotype on the physical characteristics of dwarf cashew cashews (cashew apple + nut). The experiment design was completely randomized in a factorial scheme with repeated measurements over time, applying the confounding technique, with three clones (CCP 09, BRS 265 and PRO 555-1) in two different regions, sertão (Alto Santo-CE) and coast (Beberibe-CE), with four replications, collected in 2013 and 2014. In the laboratory, the cashews were evaluated for total mass (nut and cashew apple) (g), nut and cashew apple mass (g), length (mm), apical and basal diameters of the cashew apple (mm) and firmness of the cashew apple (N). It was observed that the region and the production year influenced the physical quality of the cashews. Among the clones that were studied, CCP 09 was the only one that presented a similar behavior in both regions, showing that it can obtain satisfactory quality in different environments. The other clones differed, presenting superior physical quality on the coast. In the sertão region, the best adapted clone was CCP 09 and, on the coast, it was the PRO 555-1 clone.As variáveis de qualidade física do pedúnculo de cajueiro consistem em diferentes características externas, como aparência, tamanho, coloração, formato, firmeza, entre outros. Esses apresentam grande importância na comercialização, uma vez que são os principais atributos que atraem o consumidor no momento da compra. Diante disso, este trabalho teve por objetivo avaliar a influência da região, ano de produção e do genótipo sobre as características físicas em cajus de cajueiro-anão. O delineamento experimental adotado foi inteiramente casualizado, no esquema fatorial com medida repetida no tempo, aplicando-se a técnica de confundimento, sendo três clones (CCP 09, BRS 265 e PRO 555-1) em dois locais diferentes, sertão (Alto Santo-CE) e litoral (Beberibe-CE), com quatro repetições, colhidos nos anos de 2013 e 2014. No laboratório os cajus foram avaliados quanto a massa total (castanha e pedúnculo) em (g), massa da castanha (g), massa do pedúnculo (g), comprimento (mm), diâmetro apical e basal do pedúnculo (mm) e firmeza do pedúnculo (N). Observou-se que a região e o ano de produção influenciam na qualidade física do caju. Entre os clones estudados, o CCP 09 foi o único que apresentou comportamento semelhante em ambas as regiões. Isso mostra que o mesmo consegue expressar qualidade satisfatória em diferentes ambientes. Os demais apresentaram qualidade física superior quando cultivados no litoral. No sertão, o clone que se mostrou melhor adaptado foi o CCP 09, e no litoral o clone PRO 555-1

Mg/Ti multilayers: structural, optical and hydrogen absorption properties

Mg-Ti alloys have uncommon optical and hydrogen absorbing properties, originating from a "spinodal-like" microstructure with a small degree of chemical short-range order in the atoms distribution. In the present study we artificially engineer short-range order by depositing Pd-capped Mg/Ti multilayers with different periodicities and characterize them both structurally and optically. Notwithstanding the large lattice parameter mismatch between Mg and Ti, the as-deposited metallic multilayers show good structural coherence. Upon exposure to H2 gas a two-step hydrogenation process occurs, with the Ti layers forming the hydride before Mg. From in-situ measurements of the bilayer thickness L at different hydrogen pressures, we observe large out-of-plane expansions of the Mg and Ti layers upon hydrogenation, indicating strong plastic deformations in the films and a consequent shortening of the coherence length. Upon unloading at room temperature in air, hydrogen atoms remain trapped in the Ti layers due to kinetic constraints. Such loading/unloading sequence can be explained in terms of the different thermodynamic properties of hydrogen in Mg and Ti, as shown by diffusion calculations on a model multilayered systems. Absorption isotherms measured by hydrogenography can be interpreted as a result of the elastic clamping arising from strongly bonded Mg/Pd and broken Mg/Ti interfaces

A machine learning approach for single cell interphase cell cycle staging

The cell nucleus is a tightly regulated organelle and its architectural structure is dynamically orchestrated to maintain normal cell function. Indeed, fluctuations in nuclear size and shape are known to occur during the cell cycle and alterations in nuclear morphology are also hallmarks of many diseases including cancer. Regrettably, automated reliable tools for cell cycle staging at single cell level using in situ images are still limited. It is therefore urgent to establish accurate strategies combining bioimaging with high-content image analysis for a bona fide classification. In this study we developed a supervised machine learning method for interphase cell cycle staging of individual adherent cells using in situ fluorescence images of nuclei stained with DAPI. A Support Vector Machine (SVM) classifier operated over normalized nuclear features using more than 3500 DAPI stained nuclei. Molecular ground truth labels were obtained by automatic image processing using fluorescent ubiquitination-based cell cycle indicator (Fucci) technology. An average F1-Score of 87.7% was achieved with this framework. Furthermore, the method was validated on distinct cell types reaching recall values higher than 89%. Our method is a robust approach to identify cells in G1 or S/G2 at the individual level, with implications in research and clinical applications.This work was supported by FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE 2020), Programa Operacional de Competitividade e Internacionalização (POCI), Programa Opera-cional Regional do Norte (Norte 2020) and by National Funds through the Portuguese Foundation for Science and Technology (FCT), under the projects PTDC/BBB-IMG/0283/2014, PTDC/BTM-SAL/30383/2017, LARSyS-UIDB/50009/2020, LARSyS-UID/EEA/50009/2019, NORTE-01-0145-FEDER-000029 and doctoral grant SFRH/ BD/114687/2016. The authors acknowledge the American Association of Patients with Hereditary Gastric Cancer “No Stomach for Cancer” for funding Seruca’s research and the support of the i3S Scientific Platform Advanced Light Microscopy, member of the PPBI (PPBI-POCI-01-0145-FEDER-022122)