1,358 research outputs found
Integrating social power into the decision-making of cognitive agents
AbstractSocial power is a pervasive feature with acknowledged impact in a multitude of social processes. However, despite its importance, common approaches to social power interactions in multi-agent systems are rather simplistic and lack a full comprehensive view of the processes involved. In this work, we integrated a comprehensive model of social power dynamics into a cognitive agent architecture based on an operationalization of different bases of social power inspired by theoretical background research in social psychology. The model was implemented in an agent framework that was subsequently used to generate the behavior of virtual characters in an interactive virtual environment. We performed a user study to assess users' perceptions of the agents and found evidence supporting both the social power capabilities provided by the model and their value for the creation of believable and interesting scenarios. We expect that these advances and the collected evidence can be used to support the development of agent systems with an enriched capacity for social agent simulation
Psoriasis
Pretende-se nestas Recomendações Terapêuticas dar uma visão global dos conhecimentos actuais sobre a patogenia, clínica e tratamento da psoríase. A educação dos doentes deve incidir na evicção dos factores desencadeantes (medicamentos, trauma, álcool, infecções, stress) e enfa tizar a acção benéfica da exposição solar controlada na psoríase. A terapêutica tópica
emolientes, queratolíticos, derivados do alcatrão, antralina, corticosteróides tópicos, calcipotriol — é essencial no controlo da psoríase vulgar em placas e é importante como adjuvante nos casos
mais graves; chama-se a atenção para os graus de potência e para os potenciais efeitos indesejáveis da corticoterapia tópica. A radiação UV isolada (fototerapia) ou em associação a fotos sensibilizantes (fotoquimioterapia) está indicada nalgumas formas de psoríase (gutata, em placas, palmo-plantar) refractárias aos tópicos. A terapêutica sistémica — retinóides, metotrexato, ciclosporina está reservada para as formas mais graves, extensas e refractárias de psoríase, sendo indispensável na psoríase eritrodérmica, pustulosa ou artropática. A estratégia actual visa obter o melhor índice terapêutico e dá particular importância às terapêuticas combinadas e/ou rotativas. Para finalizar, incluem-se alguns fluxogramas, com o objectivo de ordenar os passos a
dar na abordagem do doente com psorfase e salientar a validade científica das diferentes terapêuticas disponíveis
Nicolau Livedoid Dermatitis following intramuscular benzathine penicillin injection
We report the case of a 64-year-old male presenting with a rapidly enlarging painful violaceous plaque in the left buttock and posterior thigh, following a gluteal intramuscular injection of benzathine penicillin. Associated urinary incontinence and lower left limb paresis were consistent with sciatic and lower sacral nerve damage, as confirmed by electromyography. Additional underlying muscular damage was observed in ultrasound and computer tomodensitometry scans and supported by high serum levels of creatine kinase and lactate dehydrogenase. Aggressive treatment was performed with fluid expansion, intravenous steroid bolus, vasodilators and anticoagulation, resulting in slow improvement of cutaneous and muscular lesions. However, no significant effect was observed on neurologic dysfunction after 6 months of regular neuromuscular rehabilitation. Nicolau Livedoid Dermatitis is a rare and potentially fatal condition showing variable levels of tissue impairment and unpredictable course and prognosis. Specific treatment is not consensual and the efficacy of any particular treatment remains to be established
Pityriasis lichenoides et varioliformis acute: case report and review of the literature
We report a case of a 63-year-old man hospitalized for a polymorphous generalized eruption consisting of maculopapules with peripheral scaling, vesicopustules, and ulceronecrotic and crusted lesions measuring 5-20 mm, localized on his trunk and extremities, particularly exuberant in the flexural area. Histopathology showed necrotic keratinocytes with exocytosis of red blood cells and lymphocytes and a dermal perivascular and periadnexal inflammatory infiltrate, composed of CD8+/CD4-/CD30- T cells, indicating the clinical diagnosis of pityriasis lichenoides et varioliformis acuta. He was treated with erythromycin and methylprednisolone reduced gradually over 5 months, with a slow but complete response; the patient was without lesions after 2 years of follow-up. The authors want to remind of this rare entity which may present difficulties in diagnosis and therap
Evolutionarily conserved mechanisms of male germline development in flowering plants and animals
Sexual reproduction is the main reproductive strategy of the overwhelming majority of eukaryotes. This suggests that the last eukaryotic common ancestor was able to reproduce sexually. Sexual reproduction reflects the ability to perform meiosis, and ultimately generating gametes, which are cells that carry recombined half sets of the parental genome and are able to fertilize. These functions have been allocated to a highly specialized cell lineage: the germline. Given its significant evolutionary conservation, it is to be expected that the germline programme shares common molecular bases across extremely divergent eukaryotic species. In the present review, we aim to identify the unifying principles of male germline establishment and development by comparing two very disparate kingdoms: plants and animals. We argue that male meiosis defines two temporally regulated gene expression programmes: the first is required for meiotic commitment, and the second is required for the acquisition of fertilizing ability. Small RNA pathways are a further key communality, ultimately ensuring the epigenetic stability of the information conveyed by the male germline
Essential role of the czc determinant for cadmium, cobalt and zinc resistance in Gluconacetobacter diazotrophicus PAl 5
The mechanisms of cadmium, cobalt and zinc resistance were characterized in the plant-growth-promoting bacterium Gluconacetobacter diazotrophicus PAl 5. The resistance level of the wild-type strain was evaluated through the establishment of minimum inhibitory concentrations (MIC) of the soluble compounds CdCl2·H2O, CoCl2·6H2O and ZnCl2. Gluconacetobacter diazotrophicus PAl 5 was resistant to high concentrations of Cd, Co and Zn, with MICs of 1.2, 20 and 20 mM, respectively. Screening of an insertion library from transposon EZ-Tn5<R6Kyori/KAN-2> in the presence of ZnO revealed that the mutant GDP30H3 was unable to grow in the presence of the compound. This mutant was also highly sensitive to CdCl2·H2O, CoCl2·6H2O and ZnCl2. Molecular characterization established that the mutation affected the czcA gene, which encodes a protein involved in metal efflux. In silico analysis showed that czcA is a component of the czcCBARS operon together with four other genes. This work provides evidence of the high tolerance of G. diazotrophicus PAl 5 to heavy metalsand that czc is a determinant for metal resistance in this bacterium. [Int Microbiol 2012; 15(2):69-78
Conformational dynamics of soy protein isolate under ohmic heating
Ohmic heating (OH) brings a promise of sustainable thermal processing by assuring high levels of heating efficiency and
reduction of water consumption. It is important to gather fundamental knowledge about the way how this emerging
heating method technology can affect the biological, functional, and technological properties of important molecules
such as proteins during food processing. Vegetable proteins are attracting scientific interest in the food arena, mostly due
to the need of a protein transition but also the most recent consumer trends. This work describes the effects of OH on
structural aspects of soy protein isolate (SPI). OH was applied at different electrical frequencies (i.e. from 50 Hz to 20 kHz)
and moderate electric fields (i.e. from 0 V/cm to 20 V/cm) at the onset denaturation temperature of SPI (95ºC). Different
SPI fractions, such as legumins and vicilins, were identified through non-denaturing SDS-PAGE. Through fluorescence
spectroscopy it was observed that frequencies below 500 Hz quenches tryptophan emission, suggesting structural
rearrangements of the protein folding behavior; this effect is more pronounced with increasing electric field intensity. OH
at 50 Hz resulted in a decrease of maximum intrinsic fluorescence intensity (p <0.05) of 27 % and 21 % when compared
with the non-heated SPI and heated sample without the presence of an electric field, respectively. At the same time,
treatments at 20 kHz presented a higher intrinsic fluorescence intensity than the other treatments (p < 0.05). The
exposition of hydrophobic pockets appears to be less dependent on the electrical treatments applied. By reducing the
thermal load, OH induces fewer changes on the protein´s structure, but the inherent electrochemical reactions and release
of metals from the electrodes surface (confirmed by inductively coupled plasma mass spectrometry) can promote
complexation reactions, thus changing protein folding dynamics. OH processing parameters when properly controlled
result on differentiated protein binding properties which may be of essential importance regarding their functional
properties but also for different applications in bioscience fields.info:eu-repo/semantics/publishedVersio
Early Cardiac Mitochondrial Molecular and Functional Responses to Acute Anthracycline Treatment in Wistar Rats
Doxorubicin (DOX) is an anticancer drug widely used to treat human and nonhuman tumors but the late and persistent cardio-toxicity reduces the therapeutic utility of the drug. The full mechanism(s) of DOX-induced acute, subchronic and delayed toxicity, which has a preponderant mitochondrial component, remains unclear; therefore, it is clinically relevant to identify early markers to identify patients who are predisposed to DOX-related cardiovascular toxicity. To address this, Wistar rats (16 weeks old) were treated with a single DOX dose (20 mg/kg, i.p.); then, mRNA, protein levels and functional analysis of mitochondrial endpoints were assessed 24 h later in the heart, liver, and kidney. Using an exploratory data analysis, we observed cardiac-specific alterations after DOX treatment for mitochondrial complexes III, IV, and preferentially for complex I. Conversely, the same analysis revealed complex II alterations are associated with DOX response in the liver and kidney. Interestingly, H2O2 production by the mitochondrial respiratory chain as well as loss of calcium-loading capacity, markers of subchronic toxicity, were not reliable indicators of acute DOX cardiotoxicity in this animal model. By using sequential principal component analysis and feature correlation analysis, we demonstrated for the first time alterations in sets of transcripts and proteins, but not functional measurements, that might serve as potential early acute markers of cardiac-specific mitochondrial toxicity, contributing to explain the trajectory of DOX cardiac toxicity and to develop novel interventions to minimize DOX cardiac liabilities
The use of genetic algorithms for structural optimization of hybrid sandwich panels
This paper describes the procedures followed to develop an optimization method for the design of a sandwich panel to be used in flooring applications. This sandwich panel is composed of polyurethane foam core, fibre reinforced polymer bottom layer and webs, and a fibre reinforced mortar top layer. The possibility of adopting additional internal ribs to increase the flexural and shear stiffness was also considered. The panel was described using a standard stacking sequence, coded as a string, using continuous variables to describe the geometric, economic and environmental parameters, and discrete variables to describe the laminate stack architecture. The optimization procedure was based on a global approach strategy, divided into two steps: (i) firstly, the features of each individual panel solution were assessed by analytical procedures and a fitness was assigned using a ranking function; (ii) secondly, the multi-objective optimization problem was solved by using a genetic algorithm, which performs a random search from generation to generation and keeps the “best individuals”. Penalty criteria were also considered when any panel solution was not satisfying the restrictions and design requirements. Different solutions were obtained by imposing different restrictions to the design of the sandwich panel, namely considering: (i) the length; (ii) the width; and, (iii) the use of one or two types of fibres (carbon and glass). This paper discusses the results obtained, both regarding the performance of the optimization procedure developed and the optimal solutions obtained for each case studied.The study presented in this paper is a part of the research project “EasyFloor – Development of
composite sandwich panels for rehabilitation of floor buildings”, with reference number 3480, supported
by ANI, through FEDER. The last author acknowledge the grant SFRH/BSAB/114302/2016 provided by FCT.info:eu-repo/semantics/publishedVersio
Shear behaviour of polyurethane foam
Polymeric based foams are widely used as insulation or structural core materials. Typically, plastic foams such as polyurethane (PUR) are commercially available in a variety of densities and, consequently, with distinct mechanical properties to fulfil a wide range of uses and applications. Usually, in sandwich construction, PUR foams are used as core material enclosed by two external faces of higher stiffness and strength. Since the lightweight PUR foams are relatively inexpensive, they are prone to be used as core material in sandwich construction, but may limit the ultimate strength of the sandwich panels due to core shear failure. Thus, a detailed characterization of PUR mechanical properties, namely shear modulus and shear strength, is required to efficiently use these materials in structural applications. Thereby, the present study deals with the experimental characterisation of the shear behaviour of a specific PUR closed-cell foam, with density of 70 kg/m3, in particular, considering the implications of size effect on the obtained results and on the estimation of the material properties. The experimental procedure was based on the standards ISO 1922 and ASTM C273, as well as, other existing publications, considering that this PUR is intended to be used as structural core material in sandwich panels for flooring purposes. Instrumentation included a load cell, LVDTs and digital image correlation. The present work details the experimental program and analyses the main results obtained.The study presented in this paper is a part of the research project “EasyFloor – Development of
composite sandwich panels for rehabilitation of floor buildings”, with reference number 3480, supported
by ANI, through FEDER.info:eu-repo/semantics/publishedVersio
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