562 research outputs found
Characterising strongly normalising intuitionistic sequent terms
This paper gives a characterisation, via intersection types, of the strongly normalising terms of an intuitionistic sequent calculus (where LJ easily embeds). The soundness of the typing
system is reduced to that of a well known typing system with intersection types for the ordinary lambda-calculus. The completeness of the typing system is obtained from subject expansion at root position. This paper's sequent term calculus integrates smoothly the lambda-terms with generalised application or explicit substitution. Strong normalisability of these terms as
sequent terms characterises their typeability in certain "natural'' typing systems with intersection types. The latter are in the natural deduction format, like systems previously studied by Matthes and Lengrand et al., except that they do not contain any extra, exceptional rules for typing generalised applications or substitution
Implementing gender quotas in Portugal: A success story?
The so-called Portuguese Parity Law adopted in 2006 determined that candidate lists presented for national, European and local elections must include one third minimum representation of each sex. Following its revision in 2019, the minimum percentage required for each sex increased to 40%. The implementation of the Portuguese Parity Law has succeeded in meeting the direct goals of the policy. However, can the same be said for all stages of implementation? Moreover, even when the numbers tell a success story, what practices and resistances do they conceal? And, finally, has the law contributed to gender empowerment that goes beyond the direct scope of the law? This chapter aims to answer these questions by focusing on the national Parliament and on the major Portuguese parties. It draws on the figures for candidates and MPs between 2002 and 2019 as well as on semi-directive interviews with party stakeholders. The main conclusions are the following. First, the implementation of the law takes place smoothly in all four stages of implementation, although parties have usually gone no further than the minimum quota requirements. Parties’ actions and discourses demonstrate a moderate but serious commitment to the law. Second, both explicit and implicit forms of individual resistance, as well as passive institutional resistance take place at the national level for both parties. These resistances are not intended to cause policy failure, but rather to limit policy success. Third, the indirect effects of the law (i.e., gender empowerment in Parliament) are still limited.info:eu-repo/semantics/acceptedVersio
Floristic composition patterns of Mediterranean annual non-nitrophilous grasslands in Eastern Portugal
Helianthemetea guttati communities are pioneer spring and early summer ephemeral grasslands, dominated by nonnitrophilous
therophytes. In Continental Portugal, these communities have not yet been fully investigated, and thus the
objectives of the present study are: (1) to identify community types in therophytic grasslands; (2) to recognize those
communities that configure the European priority habitat 6220* (pseudo-steppe with grasses and annuals); (3) to establish
environmental gradients underlying their spatial variation; (4) to assess how floristic composition is affected by land use
factors. Vegetation sampling using phytosociological methodology was carried out on 80 grasslands. Modified Twinspan
classification and canonical correspondence analysis (CCA) was applied for the classification and ordination of releve´s
whereas partial CCA (pCCA) and variation partitioning were used to assess the relative influence of individual land use
factors. Some 270 species were identified across 11 community types whose floristic patterns were mainly explained by
environmental gradients related to altitude and soil type while land use variables could only explain a small part of the
floristic variation. Based on biogeography and the determination of diagnostic species, four phytosociological new
associations and a new subassociation are proposed: Holco-Brachypodietum distachyi, Holco-Micropyretum tenellae, Micropyro-
Anthoxanthetum aristati and Leontodonto-Vulpietum bromoidis vulpietosum membranacea
Quem representam e a quem obedecem: atitudes dos deputados portugueses antes e depois da crise
A relação entre deputados e eleitores em Portugal tem sido interpretada como um caso
exemplar do funcionamento do “modelo de partido responsável”, em que os partidos
apresentam diferentes propostas programáticas e os deputados são eleitos com o
mandato de cumprir as orientações dos respectivos partidos, salvaguardando a disciplina
partidária e a coesão dos grupos parlamentares (Schattschneider, 1942; Converse e
Pierce, 1986). Embora este modelo apresente limitações teóricas e empíricas (LestonBandeira, 2009; Brack et al., 2012), é certo que a interpretação do mandato parlamentar
por parte dos deputados portugueses parece privilegiar os interesses da população em
geral, por um lado, e a obediência aos partidos, por outro. A proibição do mandato
imperativo previsto pela Constituição (art. 155), o sistema eleitoral proporcional com
listas fechadas, assim como o monopólio - de jure e de facto - dos partidos na
apresentação das candidaturas para as eleições legislativas e a centralização do
recrutamento são elementos que contribuem para privilegiar um tipo de representação
“colectiva” em que os interesses do país e do próprio partido prevalecem sobre os
interesses de cada círculo.info:eu-repo/semantics/acceptedVersio
Abnormal Appearance of the Umbilicus: An Indicator of Urachal Anomalies
The urachus is an intra-abdominal fibrous remnant of the allantois. The non-involution of the allantois can result in urachal anomalies. The abnormal appearance of the umbilicus may be a sign of such anomalies. We have observed 3 cases of term neonates with atypical appearance of the umbilical stump, all of which manifested urachal anomalies, as documented by ultrasound scan. These appearances are rarely described in the literature, and seem to regress at around 2 months. Therefore, it is important that healthcare professionals should be aware of the possible implications of atypical umbilical stumps, evaluate each case accordingly and, if an urachal anomaly is diagnosed, refer the patient to a paediatric surgery centre, as such malformations carry an underlying risk of infection or malignancy.info:eu-repo/semantics/publishedVersio
Permutability in proof terms for intuitionistic sequent calculus with cuts
This paper gives a comprehensive and coherent view on permutability in the intuitionistic sequent calculus with cuts. Specifically we show that, once permutability is packaged into appropriate global reduction procedures, it organizes the internal structure of the system and determines fragments with computational interest, both for the computation-as-proof-normalization and the computation-as-proof-search paradigms. The vehicle of the study is a lambda-calculus of multiary proof terms with generalized application, previously developed by the authors (the paper argues this system represents the simplest fragment of ordinary sequent calculus that does not fall into mere natural deduction). We start by adapting to our setting the concept of normal proof, developed by Mints, Dyckhoff, and Pinto, and by defining natural proofs, so that a proof is normal iff it is natural and cut-free. Natural proofs form a subsystem with a transparent Curry-Howard interpretation (a kind of formal vector notation for lambda-terms with vectors consisting of lists of lists of arguments), while searching for normal proofs corresponds to a slight relaxation of focusing (in the sense of LJT). Next, we define a process of permutative conversion to natural form, and show that its combination with cut elimination gives a concept of normalization for the sequent calculus. We derive a systematic picture of the full system comprehending a rich set of reduction procedures (cut elimination, flattening, permutative conversion, normalization, focalization), organizing the relevant subsystems and the important subclasses of cut-free, normal, and focused proofs.Partially financed by FCT through project UID/MAT/00013/2013, and by COST action CA15123 EUTYPES. The first and the last authors were partially financed by Fundação para
a Ciência e a Tecnologia (FCT) through project UID/MAT/00013/2013. The first author got
financial support by the COST action CA15123 EUTYPES.info:eu-repo/semantics/publishedVersio
Electrochemical detection of biofilms
[Excerpt] Biofilms are the result of adhesion and growth of microorganisms, creating microenvironments - a polymeric matrix - where several microbial reactions take place [1]. Usually, biofilms are divided in two groups: the ones that are beneficial, as in wastewater treatment or production of specific products, and the detrimental biofilms such as the ones that appear in drinking water pipes and heat exchangers. In any case it is very important to detect the biofilm as soon as possible, to increase its growth or to avoid the risks associated with its presence. The ideal detector must allow the easy detection of biofilms in the early stages of formation and on line. Electrochemical techniques are well known for their role in analytical chemistry, allowing the determination and quantification of a large number of organic, inorganic and biological compounds. These techniques have largely proved to provide an efficient means for detection in situ and on line of a variety of compounds [2]. [...
An optimal control problem applied to a wastewater treatment plant
This paper aims to present a mathematical model that describes
the operation of an activated sludge system during one day. Such system is
used in the majority of wastewater treatment plants and depends strongly on
the dissolved oxygen, since it is a biological treatment. To guarantee the appropriate
amount of dissolved oxygen, expensive aeration strategies are demanded,
leading to high costs in terms of energy consumption. It was considered a typical
domestic e uent as the wastewater to test the mathematical model and
it was used the ASM1 to describe the activated sludge behaviour. An optimal
control problem was formulated whose cost functional considers the trade-o
between the minimization of the control variable herein considered (the dissolved
oxygen) and the quality index that is the amount of pollution. The
optimal control problem is treated as a nonlinear optimization problem after
discretization by direct methods. The problem was then coded in the AMPL
programming language in order to carry out numerical simulations using the
NLP solver IPOPT from NEOS Server.publishe
Para além dos números: transformações de género associadas à Lei da Paridade
Para combater as desigualdades de género na política - mundo tradicionalmente masculino -, têm sido criadas medidas de ação positiva em diversos países do mundo. É o caso da Lei da Paridade, adotada em Portugal em 2006 e implementada com relativo sucesso em 2009. Sendo visível uma mudança na presença numérica das mulheres, importa analisar as consequências dessa representação de género mais equitativa. Este artigo apresenta um estudo exploratório que, apoiado na perspetiva feministainstitucionalista, pretendeu verificar se o aumento da presença das mulheres na política levou a mudanças nas relações de género. Foram realizadas 19 entrevistas individuais semiestruturadas a pessoas chave do PS, com idades entre 27 e 63 anos, nos três níveis do poder político: europeu, nacional e local. Os resultados revelam dinâmicas de mudança e de continuidade: verificam-se mudanças na agenda política, contudo, persiste uma genderização da organização política, que continua no masculino.info:eu-repo/semantics/publishedVersio
Acute Osteoarthritis: Exuberant Presentation of an Unusual Condition in the Neonatal Period
info:eu-repo/semantics/publishedVersio
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