Current report assessed measurement reproducibility and reliability of magnetic resonance spectroscopy (1H-MRS) at 3 Tesla in left and right posterior insular, pregenual and anterior midcingulate subdivisions. 10 healthy male volunteers aged 20 to 30 years were tested on four different days, of which 9 were included in the data analysis. Intra- and inter-subject variability of myo-Inositol (mI), Creatine (Cre), Glutamate (glu), total-Choline (tCho), total-N-acetylaspartate (tNAA) and combined Glutamine-Glutamate (Glx) were calculated considering the influence of movement parameters, age, daytime of measurements (...) and tissue composition. Overall mean intra-subject variability revealed small mean coefficients of variation (CV) across the four regions: 5.3% in aMCC, 6.6% in pgACC, 7.3% in pIL and 8.2% in pIR. For all neurochemicals combined, mean inter-subject variability demonstrated mean CVs of 9.05% (aMCC), 8.84% (pgACC), 10.00% (pIL) and 10.55% (pIR). Head movement, tissue composition and day time revealed no significant explanatory variance contribution suggesting a negligible influence on data. A strong correlation between Cramer-Rao Lower Bounds (CRLB; a measure of fitting errors) and the mean intra-subject CV (r=0.799, p<0.001) outlined the importance of low CRLB in order to obtain robust and finally meaningful 1H-MRS measures. The present findings confirm 1H-MRS as a reliable tool to measure brain neurochemistry in small subregions of the human brain. (shrink)

The tree-based data structure of △-tree for propositional formulas is introduced in an improved and optimised form. The △-trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A (...) at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. (shrink)

This article reviews the Dutch societal debate on euthanasia/assisted suicide in dementia cases, specifically Alzheimer's disease. It discusses the ethical and practical dilemmas created by euthanasia requests in advance directives and the related inconsistencies in the Dutch legal regulations regarding euthanasia/assisted suicide. After an initial focus on euthanasia in advanced dementia, the actual debate concentrates on making euthanasia/assisted suicide possible in the very early stages of dementia. A review of the few known cases of assisted suicide of people with so-called (...) early dementia raises the question why requests for euthanasia/assisted suicide from patients in the early stage of Alzheimer's disease are virtually non-existent. In response to this question two explanations are offered. It is concluded that, in addition to a moral discussion on the limits of anticipatory choices, there is an urgent need to develop research into the patient's perspective with regard to medical treatment and care-giving in dementia, including end-of-life care. (shrink)

In this work we deal with a general class of spatially distributed periodic SIS epidemic models with two time scales. We let susceptible and infected individuals migrate between patches with periodic time dependent migration rates. The existence of two time scales in the system allows to describe certain features of the asymptotic behavior of its solutions with the help of a less dimensional, aggregated, system. We derive global reproduction numbers governing the general spatially distributed nonautonomous system through the aggregated system. (...) We apply this result when the mass action law and the frequency dependent transmission law are considered. Comparing these global reproductive numbers to their non spatially distributed counterparts yields the following: adequate periodic migration rates allow global persistence or eradication of epidemics where locally, in absence of migrations, the contrary is expected. (shrink)

O Trabalho pretende expor os traços iniciais da fenomenologia hermenêutica de Heidegger a partir da crítica realizada pelo autor ao método crítico-teleológico do neokantismo de Baden na preleção de 1919 A ideia da filosofia e o problema da concepção de mundo.

In this paper we show that the class of fork squares has a complete orthodox axiomatization in fork arrow logic (FAL). This result may be seen as an orthodox counterpart of Venema's non-orthodox axiomatization for the class of squares in arrow logic. FAL is the modal logic of fork algebras (FAs) just as arrow logic is the modal logic of relation algebras (RAs). FAs extend RAs by a binary fork operator and are axiomatized by adding three equations to RAs equational (...) axiomatization. A proper FA is an algebra of relations where the fork is induced by an injective operation coding pair formation. In contrast to RAs, FAs are representable by proper ones and their equational theory has the expressive power of full first-order logic. A square semantics (the set of arrows is ᵎ x ᵎ for some set ᵎ) for arrow logic was defined by Y. Venema. Due to the negative results about the finite axiomatizability of representable RAs, Venema provided a non-orthodox finite axiomatization for arrow logic by adding a new rule governing the applications of a difference operator. We address here the question of extending the type of relational structures to define orthodox axiomatizations for the class of squares. Given the connections between this problem and the finitization problem addressed by I. Németi, we suspect that this cannot be done by using only logical operations. The modal version of the FA equations provides an orthodox axiomatization for FAL which is complete in view of the representability of FAs. Here we review this result and carry it further to prove that this orthodox axiomatization for FAL also axiomatizes the class of fork squares. (shrink)