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

Gender and attitudes towards immigrants: Exploring threat perceptions

Throughout the years, great attention has been paid to the gender gap in political attitudes. Whereas the differences reported by scholars are not large, they are not negligible either. Consequently, the literature highlights the divergent preferences of women and men regarding such issues as public welfare spending and punishment, not to mention issues that particularly affect women, such as gender quotas. Yet, there are many political topics in which there is a lack of stable trends regarding gender effects. This seems to be the case with attitudes toward immigration. This chapter aims to enhance our understanding of the effects of gender on public attitudes toward immigrants. It provides a comprehensive literature review of the topic, complemented by a brief empirical analysis of nine countries. In line with previous studies, the tendency for women (vis-à-vis men) to perceive immigrants as a hindrance to the economy is corroborated. By contrast, women seem to be less concerned about immigration’s impact on crime –which is a less steady output in the literature. The broadly hinted propensity of women to positively appraise immigrants’ influence on their countries’ culture is not confirmed, proving that the relationship between gender and attitudes toward immigrants is complex and multifaceted.info:eu-repo/semantics/acceptedVersio

Refocusing generalised normalisation

When defined with general elimination/application rules, natural deduction and $\lambda$-calculus become closer to sequent calculus. In order to get real isomorphism, normalisation has to be defined in a ``multiary'' variant, in which reduction rules are necessarily non-local (reason: nomalisation, like cut-elimination, acts at the \emph{head} of applicative terms, but natural deduction focuses at the \emph{tail} of such terms). Non-local rules are bad, for instance, for the mechanization of the system. A solution is to extend natural deduction even further to a \emph{unified calculus} based on the unification of cut and general elimination. In the unified calculus, a sequent term behaves like in the sequent calculus, whereas the reduction steps of a natural deduction term are interleaved with explicit steps for bringing heads to focus. A variant of the calculus has the symmetric role of improving sequent calculus in dealing with tail-active permutative conversions

Characterising strongly normalising intuitionistic terms

This paper gives a characterisation, via intersection types, of the strongly normalising proof-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 lambdal-calculus. The completeness of the typing system is obtained from subject expansion at root position. Next we use our result to analyze the characterisation of strong normalisability for three classes of intuitionistic terms: ordinary lambda-terms, LambdaJ-terms (lambda-terms with generalised application), and lambdax-terms (lambda-terms with explicit substitution). We explain via our system why the type systems iin the natural deduction format for LambdaJ and lambdax known from the literature contain extra, exceptional rules for typing generalised application or substitution; and we show a new characterisation of the beta-strongly normalising l-terms, as a corollary to a PSN-result, relating the lambda-calculus and the intuitionistic sequent calculus. Finally, we obtain variants of our characterisation by restricting the set of assignable types to sub-classes of intersection types, notably strict types. In addition, the known characterisation of the beta-strongly normalising lambda-terms in terms of assignment of strict types follows as an easy corollary of our results.Fundação para a Ciência e Tecnologi

Influence of artificial intelligence on public employment and its impact on politics: A systematic literature review

Goal:Public administration is constantly changing in response to new challenges, including the implementation of new technologies such as robotics and artificial intelligence (AI). This new dynamic has caught the attention of political leaders who are finding ways to restrain or regulate AI in public services, but also of scholars who are raising legitimate concerns about its impacts on public employment. In light of the above, the aim of this research is to analyze the influence of AI on public employment and the ways politics are reacting. Design / Methodology / Approach: We have performed a systematic literature review to disclose the state-of-the-art and to find new avenues for future research. Results: The results indicate that public services require four kinds of intelligence – mechanical, analytical, intuitive, and empathetic – albeit, with much less expression than in private services. Limitations of the investigation: This systematic review provides a snapshot of the influence of AI on public employment. Thus, our research does not cover the whole body of knowledge, but it presents a holistic understanding of the phenomenon. Practical implications: As private companies are typically more advanced in the implementation of AI technologies, the for-profit sector may provide significant contributions in the way states can leverage public services through the deployment of AI technologies. Originality / Value: This article highlights the need for states to create the necessary conditions to legislate and regulate key technological advances, which, in our opinion, has been done, but at a very slow pace.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

Kaposi’s sarcoma, case report

O Sarcoma de Kaposi (SK) é um distúrbio angioproliferativo descrito como doença benigna de pessoas idosas. Divide- se em 4 tipos: O Clássico, epidémico, endêmico e iatrogénico. Os autores descrevem o caso de um homem caucasiano de 50 anos, português, que iniciou a sintomatologia 6 anos antes do internamento com lesões urticariformes na perna direita e perda ponderal de 10 kg em 6 meses. Por agravamento das lesões e aparecimento de púrpura nos membros inferiores recorreu ao hospital. O exame objetivo era normal à exceção de púrpuras dispersas com relevo, descamativas e violáceas na região plantar e restante membros inferiores, membros superiores e tronco. As serologias para o HIV 1 e 2 foram negativas a serologia viral para o Herpes virus humano 8 IGG foi positivo, PCR H8 positivo, a biópsia das lesões com histologia foi compatível com Sarcoma de Kaposi. Iniciou o 1º ciclo de Doxorrubicina lipossómica peguilhada e manteve seguimento em Hospital dia de Oncologia.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]. [...

Restauração de um dente anterior fracturado e encerramento de diastemas: caso clínico

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Design of a learning environment for embedded system

Embedded systems have an everyday presence and direct impact in our lives. Therefore, Universities are continuously improving their courses in microprocessor and embedded programming. Although the diversity of curriculums, the availability of learning tools, where the student can practice and improve their skills, is a key factor to the success of the learning process. The platform developed and presented in this paper results from author’s experience in teaching embedded systems. From the analysis of teaching/learning needs, a learning environment based on the MSP430 family was designed. This tool can be expanded by modules and adjusted, at a specific time, to student's real needs. All modules can be interconnected by an I2C bus, allowing to expand the capabilities of the platform. The developed modules allow the practice of subjects related with digital IO, analog interface, user interface, wireless communications, and energy management and conservation.info:eu-repo/semantics/publishedVersio