182 research outputs found
Dealing Automatically with Exceptions by Introducing Specificity in ASP
Answer Set Programming (ASP), via normal logic programs, is known as a suitable framework for default reasoning since it offers both a valid formal model and operational systems. However, in front of a real world knowledge representation problem, it is not easy to represent information in this framework. That is why the present article proposed to deal with this issue by generating in an automatic way the suitable normal logic program from a compact representation of the information. This is done by using a method, based on specificity, that has been developed for default logic and which is adapted here to ASP both in theoretical and practical points of view
Cervical Artery Dissection in Young Adults in the Stroke in Young Fabry Patients (sifap1) Study
Background: Patients with carotid artery dissection (CAD) have been reported to have different vascular risk factor profiles and clinical outcomes to those with vertebral artery dissection (VAD). However, there are limited data from recent, large international studies comparing risk factors and clinical features in patients with cervical artery dissection (CeAD) with other TIA or ischemic stroke (IS) patients of similar age and sex. Methods: We analysed demographic, clinical and risk factor profiles in TIA and IS patients ≤55 years of age with and without CeAD in the large European, multi-centre, Stroke In young FAbry Patients 1 (sifap1) study. Patients were further categorised according to age (younger: 18-44 years; middle-aged: 45-55 years), sex, and site of dissection. Results: Data on the presence of dissection were available in 4,208 TIA and IS patients of whom 439 (10.4%) had CeAD: 196 (50.1%) had CAD, 195 (49.9%) had VAD, and 48 had multiple artery dissections or no information regarding the dissected artery. The prevalence of CAD was higher in women than in men (5.9 vs. 3.8%, p < 0.01), whereas the prevalence of VAD was similar in women and men (4.6 vs. 4.7%, n.s.). Patients with VAD were younger than patients with CAD (median = 41 years (IQR = 35-47 years) versus median = 45 years (IQR = 39-49 years); p < 0.01). At stroke onset, about twice as many patients with either CAD (54.0 vs. 23.1%, p < 0.001) or VAD (63.4 vs. 36.6%, p < 0.001) had headache than patients without CeAD and stroke in the anterior or posterior circulation, respectively. Compared to patients without CeAD, hypertension, concomitant cardiovascular diseases and a patent foramen ovale were significantly less prevalent in both CAD and VAD patients, whereas tobacco smoking, physical inactivity, obesity and a family history of cerebrovascular diseases were found less frequently in CAD patients, but not in VAD patients. A history of migraine was observed at a similar frequency in patients with CAD (31%), VAD (27.8%) and in those without CeAD (25.8%). Conclusions: We identified clinical features and risk factor profiles that are specific to young patients with CeAD, and to subgroups with either CAD or VAD compared to patients without CeAD. Therefore, our data support the concept that certain vascular risk factors differentially affect the risk of CAD and VAD
Physics of Seismo-electromagnetic Phenomena
The seismo-electromagnetic phenomena (SEMG) are integrated in a relatively recent research field that studies diverse phenomena such as: unusual seismo-electrical signals [1], abnormal ultra-low-frequency (ULF) seismo-electromagnetic emissions [2], very-low-frequency (VLF) and low-frequency (LF) radiobroadcast anomalies associated with ionosphere perturbations [3], variation of total electron content of the ionosphere [4], and atypical infrared emissions [5], all related with the preparatory stage of impending earthquakes. In the past, like many other branches of science like Quantum Mechanics, SEMG have been responsible for intense debates about its credibility, in this case concerning its applicability to short-term earthquake prediction [6]. In fact, the development of a truly pre-quake forecasting system is still an elusive plan, but SEM emissions are now a very well established effect extensively reported in literature. Nevertheless, much of the Physics implicated is still not fully understood.
Thus, our main effort is directed towards a systematic field observation of SEMG effects and the development of both constructive theoretical models and laboratorial experiments to promote a better understanding of the Physics engaged in these phenomena. In this presentation we will present a sum up of our recent achievements [7,8,9], focusing future work and improvements.
[1] A. Konstantaras, et al., On the electric field transient anomaly observed at the time of the Kythira M=6.9 earthquake on January 2006, Nat. Hazards Earth Syst. Sci. 7, 677 (2007).
[2] T. Bleier, et al., Investigation of ULF magnetic pulsations, air conductivity changes, and infra red signatures associated with the 30 October Alum Rock M5.4 earthquake, Nat. Hazards Earth Syst. Sci. 9, 585 (2009).
[3] P. Biagi, et al., An overview on preseismic anomalies in LF radio signals revealed in Italy by wavelet analysis, Annals of Geophysics 51, 237 (2008).
[4] V. Chauhan, et al., Ultra-low-frequency (ULF) and total electron content (TEC) anomalies observed at Agra and their association with regional earthquakes, Journal of Geodynamics 48, 68 (2009).
[5] D. Ouzounov, et al., Outgoing long wave radiation variability from IR satellite data prior to major earthquakes, Tectonophysics 431, 211 (2007).
[6] S. Uyeda, et al., Short-term earthquake prediction: Current status of seismo-electromagnetics, Tectonophysics 470, 205 (2009).
[7] H.G. Silva, et al., Atmospheric electrical field anomalies associated with seismic activity, Nat. Hazards Earth Syst. Sci. 11, 987 (2011).
[8] H. G. Silva, et al., Electric transport in different granitic rocks, EGU General Assembly 2011 (EGU 2011), 3-8 April 2011, Vienna (Austria).
[9] H.G. Silva, et al., Piezoelectric effect during solid fracture causing electromagnetic emissions, International Conference on Computational Modelling of Fracture and Failure (CFRAC 2011), 6-8 June 2011, Barcelona (Spain)
Nodal precession of WASP-33b for 11 yr by Doppler tomographic and transit photometric observations
Stars and planetary system
Stability and sensory assessment of emulsions containing propolis extract and/or tocopheryl acetate
The prevention of skin aging has been one of the main aims of cosmetic products. Propolis and tocopheryl acetate can be promising substances because of their antioxidant properties. In this study, propolis extract was obtained and associated with tocopheryl acetate in a cream formulation, which then underwent stability and sensory assessment. The formulation containing propolis extract and tocopheryl acetate proved to be stable in the preliminary stability study, demonstrating gradual darkening and slight pH decrease when subjected to 60ºC for 28 days, but showing stability on rheological study. In the sensory analysis, the formulation containing these two components was preferred by the product testers over the base cream and creams containing propolis extract or tocopheryl acetate alone. In conclusion, given the stability of the formulation and the preference of the product testers for this formulation, this association proved promising for use in cosmetic formulations.A prevenção do envelhecimento cutâneo tem sido um dos principais focos dos produtos dermocosméticos. A própolis contém substâncias com atividade antioxidante, bem como o acetato de tocoferila é conhecido por apresentar esta atividade. Porém, a própolis apresenta odor muito característico e intenso, que pode interferir no sensorial do produto. Assim, no presente trabalho, obteve-se o extrato de própolis, que foi associado ao acetato de tocoferila em uma formulação de uso tópico, que foi avaliada quanto à estabilidade e às características sensoriais. Conduziu-se um estudo de estabilidade, no qual as formulações contendo ambos os compostos apresentaram escurecimento gradual e ligeira queda no pH após 28 dias sob 60 °C, tendo sido estável no estudo reológico. Na análise sensorial, realizada com 28 provadores, a formulação contendo extrato de própolis em associação com acetato de tocoferila foi a preferida, quando comparada com o creme base e o creme contendo somente extrato de própolis ou acetato de tocoferila. Em conclusão, devido à preferência dos provadores e ao estudo de estabilidade, a associação de extrato de própolis e de acetato de tocoferila mostrou ser promissora para uso em produtos dermocosméticos
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