Study of the Fully Frustrated Clock Model using the Wang-Landau Algorithm

Monte Carlo simulations using the newly proposed Wang-Landau algorithm together with the broad histogram relation are performed to study the antiferromagnetic six-state clock model on the triangular lattice, which is fully frustrated. We confirm the existence of the magnetic ordering belonging to the Kosterlitz-Thouless (KT) type phase transition followed by the chiral ordering which occurs at slightly higher temperature. We also observe the lower temperature phase transition of KT type due to the discrete symmetry of the clock model. By using finite-size scaling analysis, the higher KT temperature $T_2$ and the chiral critical temperature $T_c$ are respectively estimated as $T_2=0.5154(8)$ and $T_c=0.5194(4)$. The results are in favor of the double transition scenario. The lower KT temperature is estimated as $T_1=0.496(2)$. Two decay exponents of KT transitions corresponding to higher and lower temperatures are respectively estimated as $\eta_2=0.25(1)$ and $\eta_1=0.13(1)$, which suggests that the exponents associated with the KT transitions are universal even for the frustrated model.Comment: 7 pages including 9 eps figures, RevTeX, to appear in J. Phys.

Landscape statistics of the low autocorrelated binary string problem

The statistical properties of the energy landscape of the low autocorrelated binary string problem (LABSP) are studied numerically and compared with those of several classic disordered models. Using two global measures of landscape structure which have been introduced in the Simulated Annealing literature, namely, depth and difficulty, we find that the landscape of LABSP, except perhaps for a very large degeneracy of the local minima energies, is qualitatively similar to some well-known landscapes such as that of the mean-field 2-spin glass model. Furthermore, we consider a mean-field approximation to the pure model proposed by Bouchaud and Mezard (1994, J. Physique I France 4 1109) and show both analytically and numerically that it describes extremely well the statistical properties of LABSP

Metastable States in High Order Short-Range Spin Glasses

The mean number of metastable states in higher order short-range spin glasses is estimated analytically using a variational method introduced by Tanaka and Edwards for very large coordination numbers. For lattices with small connectivities, numerical simulations do not show any significant dependence on the relative positions of the interacting spins on the lattice, indicating thus that these systems can be described by a few macroscopic parameters. As an extremely anisotropic model we consider the low autocorrelated binary spin model and we show through numerical simulations that its landscape has an exceptionally large number of local optima

Self-avoiding fractional Brownian motion - The Edwards model

In this work we extend Varadhan's construction of the Edwards polymer model to the case of fractional Brownian motions in $\R^d$, for any dimension $d\geq 2$, with arbitrary Hurst parameters $H\leq 1/d$.Comment: 14 page

Using abstract interpretation to produce dependable aerospace control software

In the context of software dependability, the software veri- fication process has an important role. Formal verification of programs is an activity that can be inserted in this process to improve software reliability. This paper presents the defini- tion of an approach that employs a formal verification tech- nique based on abstract interpretation. The main goal is to apply this technique as a formal activity in the software veri- fication process to help software engineers identify programs faults. The applicability of the proposed approach is demon- strated by a case study based on embedded aerospace control software. The results obtained from its use show that abstract interpretation can contribute to software dependability.Fundação para a Ciência e a Tecnologia (FCT

Low triglyceride levels are associated with a better metabolic control in patients with type 1 diabetes

<p>Abstract</p> <p>Background</p> <p>Although it is well known in the literature that high triglyceride serum (TG) levels can jeopardize the metabolic control, little is known about the influence of low TG on type 1 diabetes patients (T1D). The aim of this study is to investigate the distribution of TG serum levels in individuals with T1D and its relationship with metabolic control.</p> <p>Findings</p> <p>We reviewed the medical charts of 180 patients with T1D, who were classified in groups according to TG levels: 1) low (below 50 mg/dL); 2) normal (50-150 mg/dL); 3) high (above 150 mg/dL). TG were low in 21.1% (n = 38; group 1), normal in 68.6% (n = 123; group 2) and high in 10.6% (n = 19; group 3). High TG was associated with a poor metabolic control (p < 0.001). Patients with TG lower than 50 mg/dL had a lower HbA1c than those with TG between 50 and 150 mg/dL (7.41+/-1.50% vs 8.56%+/-1.94%; p = 0.002).</p> <p>Conclusion</p> <p>TG lower than 50 mg/dL was common and might be associated with a better metabolic control in patients with T1D, although it is not clear whether the former is the cause or consequence for the latter.</p

Psoralen analogues: synthesis, inhibitory activity of growth of human tumor cell lines and computational studies

Eight psoralens have been evaluated for their ability to inhibit the in vitro growth of three human turner cell lines representing different tumor types, MCF-7 (breast cancer), NCI-14460 (non-small cell lung cancer) and SF-268 (CNS cancer). The synthesis of four new psoralens (benzofur-ocournarins) is presented as well as the results of the ab initio calculations to find the parameters that relate the structure with the antitumor activity. This work provides supplementary information that could allow the development of new psoralen analogues with this type of biological activity.For financial support from Fundação para a Ciência e Tecnologia, Portugal (I&D no. 226/9 and to CQ-UM), POCTI and FEDER; Ph.D. grants from FCT: Ana M.A.G. Oliveira (PRAXIS XXI/BD/19707/99), Madalena Pedro (SFRH/BD/1456/2000) and César Portela (SFRH/BD/3036/2000). For financial support and research grants to FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais) and CNPq (Conselho Nacional do Desenvolvimento Científico e Tecnológico, Brazil). The authors thank National Cancer Institute, Bethesda, MD (USA) for kindly providing the tumor cell lines and Elisa Pinto for obtaining 1H-NMR and 13C-NMR spectra and elemental analyses.POCTI

Generating human-like movements on an anthropomorphic robot using an interior point method

In previous work we have presented a model for generating human-like arm and hand movements on an anthropomorphic robot involved in human-robot collaboration tasks. This model was inspired by the Posture-Based Motion-Planning Model of human movements. Numerical results and simulations for reach-to-grasp movements with two different grip types have been presented previously. In this paper we extend our model in order to address the generation of more complex movement sequences which are challenged by scenarios cluttered with obstacles. The numerical results were obtained using the IPOPT solver, which was integrated in our MATLAB simulator of an anthropomorphic robot.EU funded Project PF7 Marie Curie ``NETT - Neural Engineering Transformative Technologies'', by FEDER funds through COMPETE (Operational Programme Thematic Factors of Competitiveness) and by portuguese funds through FCT (Foundation for Science and Technology) within the projects PEst-C/MAT/UI0013/2011 and FCOMP-01-0124-FEDER-022674

The Egas Moniz histology digital platform : a dream that came true

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio