PESTICIDE REGULATION AND THE RULE-MAKING PROCESS

Agricultural and Food Policy,

Digital Design: the Quest for New Paradigms: 23rd eCAADe Conference Proceedings

As the field of computer-aided design evolved over the last thirty years or so, it has witnessed five changes of emphasis in research direction. In the first stage, the use of computers in architecture focused on the development of Computer Aided Design (CAD), that is, systems that simulated the use of drafting tools, and research was mainly concerned with the satisfaction of designers'ergonomic needs. In the second stage, there were efforts to use computer tools in non-graphical aspects of designing, such as the use of Data Base Management Systems (DBMS) in the quantity survey of buildings. The concern was to satisfy the cognitive needs of designers by focusing on the way information and knowledge were perceived, acquired, stored, and processed. In the third stage, the focus shifted to the development of realistic models of buildings to permit the assessment of design proposals. In the fourth stage, the focus was on studies concerned with the encoding of architectural knowledge into design tools (KBMS), and the discussion was whether to go towards design automation or design supporting tools. In the fifth stage, with the advent of the Internet and the development of communication tools, research became focused on the collaborative and social aspects of design activity. In recent years, research also became concerned with the exploration of the physical implications of digital media in the production of artefacts. Today, there is a vast range of research interests and approaches, but the quest for new, unifying paradigms continues

On the influence of time-series length in EMD to extract frequency content : simulations and models in biomedical signals

In this paper, fractional Gaussian noise (fGn) was used to simulate a homogeneously spreading broadband signal without any dominant frequency band, and to perform a simulation study about the influence of time-series length in the number of intrinsic mode functions (IMFs) obtained after empirical mode decomposition (EMD). In this context three models are presented. The first two models depend on the Hurst exponent H, and the last one is designed for small data lengths, in which the number of IMFs after EMD is obtained based on the regularity of the signal, and depends on an index measure of regularity. These models contribute to a better understanding of the EMD decomposition through the evaluation of its performance in fGn signals. Since an analytical formulation to evaluate the EMD performance is not available, using well-known signals allows for a better insight into the process. The last model presented is meant for application to real data. Its purpose is to predict, in function of the regularity signal, the time-series length that should be used when one wants to divide the spectrum into a pre-determined number of modes, corresponding to different frequency bands, using EMD. This is the case, e.g., in heart rate and blood pressure signals, used to assess sympathovagal balance in the central nervous system.info:eu-repo/semantics/publishedVersio

Variantes genéticas pró-trombóticas com (improváveis?) factores de risco para as grandes crises vaso-oclusivas na drepanocitose

CONTEXTO: A drepanocitose é uma anemia hemolítica hereditária com características pró-adesivas, pró-inflamatórias e pró-coagulantes, incluindo alterações na hemostase e activação da cascata da coagulação. PLANO DO ESTUDO: Neste estudo analisaram-se, em 140 drepanocíticos africanos e 126 indivíduos sem hemoglobina S também de origem africana, variantes genéticas polimórficas em quatro loci envolvidos na coagulação (F2 20210G>A e F5 R506Q), na fibrinólise (PAI-1 5G>4G), ou no metabolismo da homocisteína (MTHFR 677C>T). Estratificaram-se os pacientes em dois grupos de acordo com a ocorrência ou não de, pelo menos, uma complicação vaso-oclusiva (CVO) grave até à data da sua participação no estudo. RESULTADOS: Não se observou uma associação estatisticamente significativa entre a ocorrência de uma CVO grave e a herança do alelo predisponente à trombose, 4G no locus PAI-1 ou 677T no locus MTHFR. Nenhum drepanocítico apresentava os alelos F2 20210A ou F5 506Q (factor V Leiden). Visando excluir a possibilidade de que genuínas diferenças inter-grupos fossem mascaradas pela presença de indivíduos mais jovens no grupo sem-CVO, dividiu-se este num sub-grupo de pacientes mais novos e num sub-grupo de pacientes cuja idade não diferia significativamente do grupo com-CVO grave. Mesmo assim, não foi encontrada associação significativa. No entanto, pode observar-se, no grupo de doentes com o alelo PAI-1 4G (cuja expressão resulta numa diminuição da actividade fibrinolítica), uma tendência (OR=1,6) para um risco acrescido de CVO. Esta tendência era ligeiramente maior (OR=2,1) se se considerasse apenas a CVO síndrome torácica aguda. CONCLUSÕES: O alelo 4G no promotor do PAI-1 poderá ser um factor de risco para CVO na drepanocitose, uma hipótese a testar numa série maior de doentes, idealmente oriunda de uma população homogénea e com alta prevalência de drepanocitose