Towards a Conceptualization of Sociomaterial Entanglement

In knowledge representation, socio-technical systems can be modeled as multiagent systems in which the local knowledge of each individual agent can be seen as a context. In this paper we propose formal ontologies as a means to describe the assumptions driving the construction of contexts as local theories and to enable interoperability among them. In particular, we present two alternative conceptualizations of the notion of sociomateriality (and entanglement), which is central in the recent debates on socio-technical systems in the social sciences, namely critical and agential realism. We thus start by providing a model of entanglement according to the critical realist view, representing it as a property of objects that are essentially dependent on different modules of an already given ontology. We refine then our treatment by proposing a taxonomy of sociomaterial entanglements that distinguishes between ontological and epistemological entanglement. In the final section, we discuss the second perspective, which is more challenging form the point of view of knowledge representation, and we show that the very distinction of information into modules can be at least in principle built out of the assumption of an entangled reality

Efeito do ácido indol butírico e do carvão ativado no enraizamento in vitro de brotos de abacaxi ornmental (Ananas lucidus Miller).

A micropropagação poderá ser uma alternativa viável para aumentar o número de plantas por ano com a mesma característica genética, independente da época do ano e em menor espaço de tempo. O objetivo deste estudo foi avaliar o efeito do ácido indol butírico e do carvão ativado no enraizamento in vitro de brotos de abacaxi ornamental.bitstream/CNPAT-2010/8953/1/Pa-066.pd

A burst with double radio spectrum observed up to 212 GHz

We study a solar flare that occurred on September 10, 2002, in active region NOAA 10105 starting around 14:52 UT and lasting approximately 5 minutes in the radio range. The event was classified as M2.9 in X-rays and 1N in H\alpha. Solar Submillimeter Telescope observations, in addition to microwave data give us a good spectral coverage between 1.415 and 212 GHz. We combine these data with ultraviolet images, hard and soft X-rays observations and full-disk magnetograms. Images obtained from Ramaty High Energy Solar Spectroscopic Imaging data are used to identify the locations of X-ray sources at different energies and to determine the X-ray spectrum, while ultra violet images allow us to characterize the coronal flaring region. The magnetic field evolution of the active region is analyzed using Michelson Doppler Imager magnetograms. The burst is detected at all available radio-frequencies. X-ray images (between 12 keV and 300 keV) reveal two compact sources and 212 GHz data, used to estimate the radio source position, show a single compact source displaced by 25" from one of the hard X-ray footpoints. We model the radio spectra using two homogeneous sources, and combine this analysis with that of hard X-rays to understand the dynamics of the particles. Relativistic particles, observed at radio wavelengths above 50 GHz, have an electron index evolving with the typical soft-hard-soft behaviour.Comment: Submitted to Solar Physics, 20 pages, 8 fugure

Organizaçção laboratorial: Boas práticas de laboratório (BPL) na Embrapa Agrobiologia.

Sistema de qualidade. Objetivo do credenciamento em BPL. Escopo da norma. Campos de aplicação. Definições. Ações gerais. Organização e pessoal da unidade operacional (responsabilidades). Unidade de garantia de qualidade. Unidades operacionais. Equipamentos, materiais e reagentes. Substância-teste e substância de referência. Procedimentos operaconais padrão (POP). Execução dos estudos. Relatório final e arquivamento de registros e material.bitstream/CNPAB-2010/32964/1/doc197.pd

Numerical investigation of the in-plane seismic performance of unstrengthened and TRM-strengthened rammed earth walls

The large availability of raw earth around the World led to its extensive use as a building material through history. Thus, earthen materials integrate several historical monuments, but their main use was to build living and working environments for billions of people. On the other hand, past earthquakes revealed their inadequate seismic behavior, which is a matter of concern as a significant percentage of earthen buildings are located in regions with medium to high seismic hazard. Nevertheless, their seismic behavior and the development of efficient strengthening solutions are topics that are not yet sufficiently investigated in the literature. In this context, this study investigates numerically the in-plane seismic behavior of a rammed earth component by means of advanced nonlinear finite element modeling, which included performing nonlinear static (pushover) and nonlinear dynamic analyses. Moreover, the strengthening effectiveness of a low-cost textile-reinforced mortar on such component was also evaluated. The strengthening was observed to increase the load and displacement capacities, to preserve the integrity for higher lateral load levels and to postpone failure without adding significant mass to the system. Furthermore, the pushover analysis was shown to predict reliably the capacities of the models with respect to the incremental dynamic analysis.This work was financed by FEDER funds through the Competitively Factors Operational Programme (COMPETE) and by national funds through the Foundation for Science and Technology (FCT) within the scope of projects POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014) and POCI-01-0145-FEDER-007633. The support from grant SFRH/BPD/97082/2013 is also acknowledged

Evaluation of different formulations of gellan gum-based hydrogels for tissue engineering of intervertebral disc

Gellan gum based-hydrogels present advantageous features for application as acellular and cellular nucleus pulposus (NP) substitutes due to the possibility of fine-tuning its physico-chemical and biological properties. In this study, ionic-crosslinked hydrogel discs were produced by means of mixing a raw and chemically modified material, i.e., high acyl gellan gum (HAGG) and methacrylated low acyl gellan gum (GG-MA), respectively. The hydrogel discs were characterized in terms of its mechanical properties and degradation/swelling ability. The biocompatibility of the different hydrogel formulations was assessed in vitro using NP rabbit cells isolated from the intervertebral disc. The biological performance of the developed gellan gum-based hydrogels formulations was evaluated by: (i) culturing of NP cells in the presence of the hydrogel leachables, and (ii) seeding or encapsulation of the NP cells within the hydrogels. The present work demonstrated that as HAGG content increases, the modulus of the hydrogels decreases. Moreover, the increase of the HAGG content induces a higher weight loss of the GG-MA/HA-GG formulation as compared to GG-MA hydrogel. The in vitro study revealed that hydrogels are non-cytotoxic and support the encapsulation of rabbit NP cells. The methacrylated gellan gum and formulations possessing high acyl gellan gum present tunable properties that may be interesting for application as NP substitutes

Duality symmetry, strong coupling expansion and universal critical amplitudes in two-dimensional \Phi^{4} field models

We show that the exact beta-function \beta(g) in the continuous 2D g\Phi^{4} model possesses the Kramers-Wannier duality symmetry. The duality symmetry transformation \tilde{g}=d(g) such that \beta(d(g))=d'(g)\beta(g) is constructed and the approximate values of g^{*} computed from the duality equation d(g^{*})=g^{*} are shown to agree with the available numerical results. The calculation of the beta-function \beta(g) for the 2D scalar g\Phi^{4} field theory based on the strong coupling expansion is developed and the expansion of \beta(g) in powers of g^{-1} is obtained up to order g^{-8}. The numerical values calculated for the renormalized coupling constant g_{+}^{*} are in reasonable good agreement with the best modern estimates recently obtained from the high-temperature series expansion and with those known from the perturbative four-loop renormalization-group calculations. The application of Cardy's theorem for calculating the renormalized isothermal coupling constant g_{c} of the 2D Ising model and the related universal critical amplitudes is also discussed.Comment: 16 pages, REVTeX, to be published in J.Phys.A:Math.Ge

Influência dos meios de cultura sólido e líquido no alongamento de brotos in vitro de abacaxi ornamental (Ananas lucidus Miller).

Influencia dos meios de cultura solido e liquido no alongamento de brotoss in vitro de abacaxi ornamental.bitstream/CNPAT-2010/5395/1/Pa-057.pd

Heterotic String Compactifications on Half-flat Manifolds II

In this paper, we continue the analysis of heterotic string compactifications on half-flat mirror manifolds by including the 10-dimensional gauge fields. It is argued, that the heterotic Bianchi identity is solved by a variant of the standard embedding. Then, the resulting gauge group in four dimensions is still E6 despite the fact that the Levi-Civita connection has SO(6) holonomy. We derive the associated four-dimensional effective theories including matter field terms for such compactifications. The results are also extended to more general manifolds with SU(3) structure.Comment: 31 page

Responses of woody species to spatial and temporal ground water changes in coastal sand dune systems

In spite of the relative importance of groundwater in costal dune systems, studies concerning the responses of vegetation to ground water (GW) availability variations, particularly in Mediterranean regions, are scarce. Thus, the main purpose of this study is to compare the responses of co-occurring species possessing different functional traits, to changes in GW levels (i.e. the lowering of GW levels) in a sand dune ecosystem. For that, five sites were established within a 1 km<sup>2</sup> area in a meso-mediterranean sand dune ecosystem dominated by a <i>Pinus pinaster</i> forest. Due to natural topographic variability and anthropogenic GW exploitation, substantial variability in depth to GW between sites was found. Under these conditions it was possible to identify the degree of usage and dependence on GW of different plant species (two deep-rooted trees, a drought adapted shrub, a phreatophyte and a non-native woody invader) and how GW dependence varied seasonally and between the heterogeneous sites. Results indicated that the plant species had differential responses to changes in GW depth according to specific functional traits (i.e. rooting depth, leaf morphology, and water use strategy). Species comparison revealed that variability in pre-dawn water potential (Ψ<sub>pre</sub>) and bulk leaf δ<sup>13</sup>C was related to site differences in GW use in the deep-rooted (<i>Pinus pinaster, Myrica faya</i>) and phreatophyte (<i>Salix repens</i>) species. However, such variation was more evident during spring than during summer drought. The exotic invader, <i>Acacia longifolia</i>, which does not possess a very deep root system, presented the largest seasonal variability in Ψ<sub>pre</sub> and bulk leaf δ<sup>13</sup>C. In contrast, the response of <i>Corema album</i>, an endemic understory drought-adapted shrub, seemed to be independent of water availability across seasons and sites. Thus, the susceptibility to lowering of GW due to anthropogenic exploitation, in plant species from sand dunes, is variable, being particularly relevant for deep rooted species and phreatophytes, which seem to depend heavily on access to GW