Como reagimos e interpretamos os latidos dos cães de acordo com a variação acústica?

Os cães dividem o ambiente com os humanos há milhares de anos e essa relação se torna cada vez mais estreita. Estudos mostram que há comunicação intraespecífica entre os cães e interespecífica entre os cães e os humanos, tanto vocal quanto não-vocal. Os latidos se apresentam hipertrofiados nos cães e acredita-se que isso se deva ao processo de domesticação. Neste estudo, investigamos como os humanos percebem o conteúdo emocional dos latidos e como respondem aos latidos quanto ao grau de irritação percebido, em função das características acústicas de cada chamado. Sessenta participantes, divididos de acordo com a experiência com cães e com o sexo, ouviram 27 sequências de latidos gravadas anteriormente. As sequências de latidos foram montadas artificialmente e categorizadas de acordo com a frequência fundamental, harmonicidade e intervalo entre latidos. Os resultados confirmaram o pressuposto de que tais parâmetros acústicos são importantes para a percepção humana de um conteúdo emocional na vocalização de cães e que causam um impacto emocional em nós, a irritação. Os resultados também foram consistentes com as regras de estrutura-motivação de Morton (1977). Quanto mais baixa a frequência fundamental, maior a agressividade percebida e sons mais agudos e tonais estão relacionados ao medo e ao desespero; quanto mais baixa a harmonicidade, ou seja, quanto mais áspero ou rouco, maior a motivação agressiva. O intervalo entre latidos se mostrou significativo apenas na atribuição da agressividade, quanto mais curtos os intervalos, maior a agressividade percebida. A correlação entre o grau de irritação causado pelos latidos e a percepção das emoções mostrou que quanto maior a percepção de agressividade, medo e desespero, maior o grau de irritação e quanto maior a percepção de brincadeira e felicidade, menor o grau de irritação causado pelos latidos. Esses resultados sugerem que a irritação gerada pelos latidos dos cães está associada a emoções negativas. Quanto ao sexo, os homens obtiveram valores médios significativamente maiores do que as mulheres na avaliação da irritação, o que sugere que os homens possam ter uma menor tolerância com os chamados caninos. Os resultados deste estudo nos levam a concluir que os humanos são capazes de identificar os estados emocionais dos cães através de emissões sonoras. Isto sugere que há uma comunicação interespecífica entre estas espécies e que ambas dividem as mesmas regras acústicas de motivação-estrutural de Morton.

Phase diagrams of particles with dissimilar patches: X-junctions and Y-junctions

We use Wertheim's first-order perturbation theory to investigate the phase behaviour and the structure of coexisting fluid phases for a model of patchy particles with dissimilar patches (two patches of type A and f(B) patches of type B). A patch of type alpha = {A, B} can bond to a patch of type beta = {A, B} in a volume nu(alpha beta), thereby decreasing the internal energy by epsilon(alpha beta). We analyse the range of model parameters where AB bonds, or Y-junctions, are energetically disfavoured (epsilon(AB) < epsilon(AA)/2) but entropically favoured (nu(AB) >> nu(alpha alpha)), and BB bonds, or X-junctions, are energetically favoured (epsilon(BB) > 0). We show that, for low values of epsilon(BB)/epsilon(AA), the phase diagram has three different regions: (i) close to the critical temperature a low-density liquid composed of long chains and rich in Y-junctions coexists with a vapour of chains; (ii) at intermediate temperatures there is coexistence between a vapour of short chains and a liquid of very long chains with X-and Y-junctions; (iii) at low temperatures an ideal gas coexists with a high-density liquid with all possible AA and BB bonds formed. It is also shown that in region (i) the liquid binodal is reentrant (its density decreases with decreasing temperature) for the lower values of epsilon(BB)/epsilon(AA). The existence of these three regions is a consequence of the competition between the formation of X- and Y-junctions: X-junctions are energetically favoured and thus dominate at low temperatures, whereas Y-junctions are entropically favoured and dominate at higher temperatures.

Patching up dipoles: can dipolar particles be viewed as patchy colloids?

We investigate whether the liquid-vapour phase transition of strongly dipolar fluids can be understood using a model of patchy colloids. These consist of hard spherical particles with three short-ranged attractive sites (patches) on their surfaces. Two of the patches are of type A and one is of type B. Patches A on a particle may bond either to a patch A or to a patch B on another particle. Formation of an AA (AB) bond lowers the energy by epsilon AA (epsilon AB). In the limit [image omitted], this patchy model exhibits condensation driven by AB-bonds (Y-junctions). Y-junctions are also present in low-density, strongly dipolar fluids, and have been conjectured to play a key role in determining their critical behaviour. We map the dipolar Yukawa hard-sphere (DYHS) fluid onto this 2A + 1B patchy model by requiring that the latter reproduce the correct DYHS critical point as a function of the isotropic interaction strength epsilon Y. This is achieved for sensible values of epsilon AB and the bond volumes. Results for the internal energy and the particle coordination number are in qualitative agreement with simulations of DYHSs. Finally, by taking the limit [image omitted], we arrive at a new estimate for the critical point of the dipolar hard-sphere fluid, which agrees with extrapolations from simulation.

Reentrant Phase Diagram of Network Fluids

We introduce a microscopic model for particles with dissimilar patches which displays an unconventional "pinched'' phase diagram, similar to the one predicted by Tlusty and Safran in the context of dipolar fluids [Science 290, 1328 (2000)]. The model-based on two types of patch interactions, which account, respectively, for chaining and branching of the self-assembled networks-is studied both numerically via Monte Carlo simulations and theoretically via first-order perturbation theory. The dense phase is rich in junctions, while the less-dense phase is rich in chain ends. The model provides a reference system for a deep understanding of the competition between condensation and self-assembly into equilibrium-polymer chains.

O conteúdo orgânico do sedimento influencia na distribuição intraespecífica de caranguejos-chama-maré

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Economic burden of expected epidemiological changes in diseases related to tobacco, Mexico

OBJECTIVE: To determine health care costs and economic burden of epidemiological changes in diseases related to tobacco consumption. METHODS: A time-series analysis in Mexico (1994-2005) was carried out on seven health interventions: chronic obstructive pulmonary diseases, lung cancer with and without surgical intervention, asthma in smokers and non-smokers, full treatment course with nicotine gum, and full treatment course with nicotine patch. According with Box-Jenkins methodology, probabilistic models were developed to forecast the expected changes in the epidemiologic profile and the expected changes in health care services required for selected interventions. Health care costs were estimated following the instrumentation methods and validated with consensus technique. RESULTS: A comparison of the economic impact in 2006 vs. 2008 showed 20-90% increase in expected cases depending on the disease (p<0.05), and 25-93% increase in financial requirements (p<0.01). The study data suggest that changes in the demand for health services for patients with respiratory diseases related to tobacco consumption will continue showing an increasing trend. CONCLUSIONS: In economic terms, the growing number of cases expected during the study period indicates a process of internal competition and adds an element of intrinsic competition in the management of preventive and curative interventions. The study results support the assumption that if preventive programs remain unchanged, the increasing demands for curative health care may cause great financial and management challenges to the health care system of middle-income countries like Mexico.

Sistema de aquisição de dados em tempo real

Neste trabalho propus-me realizar um Sistema de Aquisição de Dados em Tempo Real via Porta Paralela. Para atingir com sucesso este objectivo, foi realizado um levantamento bibliográfico sobre sistemas operativos de tempo real, salientando e exemplificando quais foram marcos mais importantes ao longo da sua evolução. Este levantamento permitiu perceber o porquê da proliferação destes sistemas face aos custos que envolvem, em função da sua aplicação, bem como as dificuldades, científicas e tecnológicas, que os investigadores foram tendo, e que foram ultrapassando com sucesso. Para que Linux se comporte como um sistema de tempo real, é necessário configura-lo e adicionar um patch, como por exemplo o RTAI ou ADEOS. Como existem vários tipos de soluções que permitem aplicar as características inerentes aos sistemas de tempo real ao Linux, foi realizado um estudo, acompanhado de exemplos, sobre o tipo de arquitecturas de kernel mais utilizadas para o fazer. Nos sistemas operativos de tempo real existem determinados serviços, funcionalidades e restrições que os distinguem dos sistemas operativos de uso comum. Tendo em conta o objectivo do trabalho, e apoiado em exemplos, fizemos um pequeno estudo onde descrevemos, entre outros, o funcionamento escalonador, e os conceitos de latência e tempo de resposta. Mostramos que há apenas dois tipos de sistemas de tempo real o ‘hard’ que tem restrições temporais rígidas e o ‘soft’ que engloba as restrições temporais firmes e suaves. As tarefas foram classificadas em função dos tipos de eventos que as despoletam, e evidenciando as suas principais características. O sistema de tempo real eleito para criar o sistema de aquisição de dados via porta paralela foi o RTAI/Linux. Para melhor percebermos o seu comportamento, estudamos os serviços e funções do RTAI. Foi dada especial atenção, aos serviços de comunicação entre tarefas e processos (memória partilhada e FIFOs), aos serviços de escalonamento (tipos de escalonadores e tarefas) e atendimento de interrupções (serviço de rotina de interrupção - ISR). O estudo destes serviços levou às opções tomadas quanto ao método de comunicação entre tarefas e serviços, bem como ao tipo de tarefa a utilizar (esporádica ou periódica). Como neste trabalho, o meio físico de comunicação entre o meio ambiente externo e o hardware utilizado é a porta paralela, também tivemos necessidade de perceber como funciona este interface. Nomeadamente os registos de configuração da porta paralela. Assim, foi possível configura-lo ao nível de hardware (BIOS) e software (módulo do kernel) atendendo aos objectivos do presente trabalho, e optimizando a utilização da porta paralela, nomeadamente, aumentando o número de bits disponíveis para a leitura de dados. No desenvolvimento da tarefa de hard real-time, foram tidas em atenção as várias considerações atrás referenciadas. Foi desenvolvida uma tarefa do tipo esporádica, pois era pretendido, ler dados pela porta paralela apenas quando houvesse necessidade (interrupção), ou seja, quando houvesse dados disponíveis para ler. Desenvolvemos também uma aplicação para permitir visualizar os dados recolhidos via porta paralela. A comunicação entre a tarefa e a aplicação é assegurada através de memória partilhada, pois garantindo a consistência de dados, a comunicação entre processos do Linux e as tarefas de tempo real (RTAI) que correm ao nível do kernel torna-se muito simples. Para puder avaliar o desempenho do sistema desenvolvido, foi criada uma tarefa de soft real-time cujos tempos de resposta foram comparados com os da tarefa de hard real-time. As respostas temporais obtidas através do analisador lógico em conjunto com gráficos elaborados a partir destes dados, mostram e comprovam, os benefícios do sistema de aquisição de dados em tempo real via porta paralela, usando uma tarefa de hard real-time.

Exposure to fungi in cork: potential occupational hazard

Cork is a light, porous and impermeable material extracted from the bark of some trees. It is in manufacture of stoppers for wine bottles the main application of cork. It is estimated that the area occupied by cork oaks in the Iberian Peninsula is around 33% in Portugal and 23% in Spain. The world production of cork is focused in the south Europe, with Portugal being the most important producer followed by Spain. According to Companies Directory more than 100 manufactories from Portugal has their branch associated with the preparation and fabrication of cork. Cork workers are at risk for developing diseases of the respiratory tract such as occupational asthma and Suberosis, a form of pulmonary hypersensitivity due to repeated exposure to mouldy cork dust. In this review study papers from 2000 were analyzed to better understand which fungi species are associated with occupational disease in cork workers. The most prevalent fungi species in these workers that are associated with those occupational diseases are Penicilliumglabrum, Chrysoniliasitophila and Trichodermalongibrachiatum. Therefore, a specific knowledge about occupational exposure to fungi in the cork industry is the key to better understand the related diseases and to define preventive measures. Given the importance of this occupational setting in Portugal is essential to evaluate the combined exposure of fungi and particles and their metabolites. Further studies concerning exposure assessment to fungi and particles in the cork industry must be developed.

Enhancing the real-time capabilities of the Linux Kernel

The mainline Linux Kernel is not designed forhard real-time systems; it only fits the requirements of soft realtimesystems. In recent years, a kernel developer communityhas been working on the PREEMPT-RT patch. This patch(that aims to get a fully preemptible kernel) adds some realtimecapabilities to the Linux kernel. However, in terms ofscheduling policies, the real-time scheduling class of Linux islimited to the First-In-First-Out (SCHED_FIFO) and Round-Robin (SCHED_RR) scheduling policies. These scheduling policiesare however quite limited in terms of realtime performance.Therefore, in this paper, we report one importantcontribution for adding more advanced real-time capabilitiesto the Linux Kernel. Specifically, we describe modificationsto the (PREEMPT-RT patched) Linux kernel to supportreal-time slot-based task-splitting scheduling algorithms. Ourpreliminary evaluation shows that our implementation exhibitsa real-time performance that is superior to the schedulingpolicies provided by the current version of PREMPT-RT. Thisis a significant add-on to a widely adopted operating system.

Microfacies studies of carbonate rocks from Jurassic outcrops in the north of Faro, Southern Portugal

The Middle and Upper Jurassique limestones investigated were sub-divided into nine microfacies (MF) types. The firsts four represent Bathonian sediments with shallow water characteristics typical for carbonate platforms. They are comparable with Wilson's facies zones 6 to 8. Reef and reef debris, near-shore clastic-dominated limestones are not present. These MF-types are reiterated several times without cyclicity. The vertical development of the differentiated facies units indicates a close interfingering. The microfacies data are typical of inter to shallow subtidal environments; both authigenous quartz and low faunal and floral diversity of several layers point to temporary restricted conditions. The occurrence of Dictyoconus cayeuxi LUCAS and Callovian ammonites from the above lying strata argue for a Bathonian age. The MF-types 5-9 (Oxfordian-Kimmeridgian) show completely different sedimentation conditions. Fully marine nearshore recifal limestones alternate with pelagic sediments formed at deeper shelf areas. The pelagic micritic limestones of Oxfordian age are characterized by allodapic intercalations whereas the Oxfordian/Kimmeridgian limestones with tuberolithic fabrics often show intensive silifications. Only initial patch reef growth-stages were reached during the development of the Oxfordian and Kimmeridgian shallow water limestones.

Strap repair optimization by using embedded patches

Adhesively-bonded techniques offer an attractive option for repair of aluminium structures, and currently there are three widely used configurations, i.e., single-strap (SS), double-strap (DS) and scarf repairs. SS and DS repairs are straightforward to execute but stresses in the adhesive layer peak at the ends of the overlap. DS repairs additionally require both sides of the damaged structures to be reachable for repair, which is often not possible. In these repair configurations, some limitations emerge such as the weight, aerodynamic performance and aesthetics. The scarf repair is more complex to fabricate but stresses are more uniform along the adhesive bondline. Few studies of SS and DS repairs with embedded patches, such that these are completely flush with the adherends, are available in the literature. Furthermore, no data is available about the effects of geometrical and material parameters (e.g. the Young’s modulus of adhesive, E) on the mechanical behaviour optimization of embedded repairs. For this purpose, in this work standard SS and DD repairs, and also with embedded patches in the adherends, were tested under tension to allow the geometry optimization, by varying the overlap length (LO), thus allowing the maximization of the repairs strength. The influence of the patch embedding technique, showing notorious advantages such as aerodynamic or aesthetics, was compared in strength with standard strap repairs, for the viability analysis of its implementation. As a result of this work, some conclusions were drawn for the design optimization of bonded repairs on aluminium structures.

Numerical and experimental study of tensile strength of single and double-strap repairs

Adhesive bonding as a joining or repair method has a wide application in many industries. Repairs with bonded patches are often carried out to re-establish the stiffness at critical regions or spots of corrosion and/or fatigue cracks. Single and double-strap repairs (SS and DS, respectively) are a viable option for repairing. For the SS repairs, a patch is adhesively-bonded on one of the structure faces. SS repairs are easy to execute, but the load eccentricity leads to peel peak stresses at the overlap edges. DS repairs involve the use of two patches, one on each face of the structure. These are more efficient than SS repairs, due to the doubling of the bonding area and suppression of the transverse deflection of the adherends. Shear stresses also become more uniform as a result of smaller differential straining. The experimental and Finite Element (FE) study presented here for strength prediction and design optimization of bonded repairs includes SS and DS solutions with different values of overlap length (LO). The examined values of LO include 10, 20 and 30 mm. The failure strengths of the SS and DS repairs were compared with FE results by using the Abaqus® FE software. A Cohesive Zone Model (CZM) with a triangular shape in pure tensile and shear modes, including the mixed-mode possibility for crack growth, was used to simulate fracture of the adhesive layer. A good agreement was found between the experiments and the FE simulations on the failure modes, elastic stiffness and strength of the repairs, showing the effectiveness and applicability of the proposed FE technique in predicting strength of bonded repairs. Furthermore, some optimization principles were proposed to repair structures with adhesively-bonded patches that will allow repair designers to effectively design bonded repairs.

Using a cohesive damage model to predict the tensile behaviour of CFRP single-strap repairs

This work addresses both experimental and numerical analyses regarding the tensile behaviour of CFRP single-strap repairs. Two fundamental geometrical parameters were studied: overlap length and patch thickness. The numerical model used ABAQUS® software and a developed cohesive mixed-mode damage model adequate for ductile adhesives, and implemented within interface finite elements. Stress analyses and strength predictions were carried out. Experimental and numerical comparisons were performed on failure modes, failure load and equivalent stiffness of the repair. Good correlation was found between experimental and numerical results, showing that the proposed model can be successfully applied to bonded joints or repairs.

Experimental and numerical evaluation of composite repairs on wood beams damaged by cross-graining

An experimental and Finite Element study was performed on the bending behaviour of wood beams of the Pinus Pinaster species repaired with adhesively-bonded carbon–epoxy patches, after sustaining damage by cross-grain failure. This damage is characterized by crack growth at a small angle to the beams longitudinal axis, due to misalignment between the wood fibres and the beam axis. Cross-grain failure can occur in large-scale in a wood member when trees that have grown spirally or with a pronounced taper are cut for lumber. Three patch lengths were tested. The simulations include the possibility of cohesive fracture of the adhesive layer, failure within the wood beam in two propagation planes and patch interlaminar failure, by the use of cohesive zone modelling. The respective cohesive properties were estimated either by an inverse method or from the literature. The comparison with the tests allowed the validation of the proposed methodology, opening a good perspective for the reduction of costs in the design stages of these repairs due to extensive experimentation.

Buckling strength of adhesively-bonded single and double-strap repairs on carbon-epoxy structures

This work reports on an experimental and finite element method (FEM) parametric study of adhesively-bonded single and double-strap repairs on carbon-epoxy structures under buckling unrestrained compression. The influence of the overlap length and patch thickness was evaluated. This loading gains a particular significance from the additional characteristic mechanisms of structures under compression, such as fibres microbuckling, for buckling restrained structures, or global buckling of the assembly, if no transverse restriction exists. The FEM analysis is based on the use of cohesive elements including mixed-mode criteria to simulate a cohesive fracture of the adhesive layer. Trapezoidal laws in pure modes I and II were used to account for the ductility of most structural adhesives. These laws were estimated for the adhesive used from double cantilever beam (DCB) and end-notched flexure (ENF) tests, respectively, using an inverse technique. The pure mode III cohesive law was equalled to the pure mode II one. Compression failure in the laminates was predicted using a stress-based criterion. The accurate FEM predictions open a good prospect for the reduction of the extensive experimentation in the design of carbon-epoxy repairs. Design principles were also established for these repairs under buckling.