Nonlinear behavior of gelatin networks reveals a hierarchical structure

We investigate the strain hardening behavior of various gelatin networks-namely physical gelatin gel, chemically cross-linked gelatin gel, and a hybrid gel made of a combination of the former two-under large shear deformations using the pre-stress, strain ramp, and large amplitude oscillations shear protocols. Further, the internal structures of physical gelatin gels and chemically cross-linked gelatin gels were characterized by small angle neutron scattering (SANS) to enable their internal structures to be correlated with their nonlinear rheology. The Kratky plots of SANS data demonstrate the presence of small cross-linked aggregates within the chemically cross-linked network whereas, in the physical gelatin gels, a relatively homogeneous structure is observed. Through model fitting to the scattering data, we were able to obtain structural parameters, such as the correlation length (ξ), the cross-sectional polymer chain radius (Rc) and the fractal dimension (df) of the gel networks. The fractal dimension df obtained from the SANS data of the physical and chemically cross-linked gels is 1.31 and 1.53, respectively. These values are in excellent agreement with the ones obtained from a generalized nonlinear elastic theory that has been used to fit the stress-strain curves. The chemical cross-linking that generates coils and aggregates hinders the free stretching of the triple helix bundles in the physical gels.

Seismic behavior of concrete block masonry buildings

Tese de Doutoramento em Engenharia Civil

Development of a model for occupational risk acceptance criteria definition in industrial settings

Doctoral Dissertation for PhD degree in Industrial and Systems Engineering

“PhenoWorld”: a new multidimensional strategy for studying behaviour in rodents

Tese de Doutoramento em Ciências da Saúde

Behavior-based price discrimination in a multi-dimensional preferences market

NIPE WP 04/ 2016

The role of IFNγ in higher brain function: in health and under chronic stress

Tese de Doutoramento em Ciências da Saúde

Tapping the wealth of microbial data in high-throughput metabolic model reconstruction

Genome-scale metabolic models are valuable tools in the metabolic engineering process, based on the ability of these models to integrate diverse sources of data to produce global predictions of organism behavior. At the most basic level, these models require only a genome sequence to construct, and once built, they may be used to predict essential genes, culture conditions, pathway utilization, and the modifications required to enhance a desired organism behavior. In this chapter, we address two key challenges associated with the reconstruction of metabolic models: (a) leveraging existing knowledge of microbiology, biochemistry, and available omics data to produce the best possible model; and (b) applying available tools and data to automate the reconstruction process. We consider these challenges as we progress through the model reconstruction process, beginning with genome assembly, and culminating in the integration of constraints to capture the impact of transcriptional regulation. We divide the reconstruction process into ten distinct steps: (1) genome assembly from sequenced reads; (2) automated structural and functional annotation; (3) phylogenetic tree-based curation of genome annotations; (4) assembly and standardization of biochemistry database; (5) genome-scale metabolic reconstruction; (6) generation of core metabolic model; (7) generation of biomass composition reaction; (8) completion of draft metabolic model; (9) curation of metabolic model; and (10) integration of regulatory constraints. Each of these ten steps is documented in detail.

A cumulative risk model of child physical maltreatment potential: findings from a community-based study

"Published online before print November 20, 2015"

Medida da aliança parental: validação portuguesa e construção de uma versão reduzida

Objetivo: A Medida de Aliança Parental (PAM) avalia a qualidade da relação interparental na prestação de cuidados da criança. O presente artigo apresenta a validação de uma versão portuguesa da medida, bem como examina as qualidades psicométricas de uma versão reduzida com 6 itens do instrumento (PAM-R). Método: A amostra foi constituída por 182 pais (63% mães), dos quais 72 preencheram um instrumento de avaliação dos problemas de ajustamento psicológico das crianças. Resultados: As análises fatoriais confirmatórias não corroboraram a estrutura dos dois modelos testados. No entanto, excelentes valores foram encontrados nos índices de adequação do modelo da PAM-R. Não foram encontrados erros de especificação no modelo unidimensional testado, o que suporta a validade fatorial da versão reduzida da PAM. A PAM-R apresentou excelentes valores de consistência interna e uma correlação negativa e significativa com a medida de problemas de ajustamento das crianças. Conclusões: PAM-R emerge como uma medida que possibilita a avaliação do impacto das dimensões familiares no funcionamento e desenvolvimento psicológico das crianças, em contextos de prestação de cuidados de saúde primários.

Insights on the mechanical behavior of keratin fibrils

Supplementary data associated with this article can be found,in the online version, at http://dx.doi.org/10.1016/j.ijbiomac.2016.05.018.