The ground state energy of the Edwards-Anderson spin glass model with a parallel tempering Monte Carlo algorithm

We study the efficiency of parallel tempering Monte Carlo technique for calculating true ground states of the Edwards-Anderson spin glass model. Bimodal and Gaussian bond distributions were considered in two and three-dimensional lattices. By a systematic analysis we find a simple formula to estimate the values of the parameters needed in the algorithm to find the GS with a fixed average probability. We also study the performance of the algorithm for single samples, quantifying the difference between samples where the GS is hard, or easy, to find. The GS energies we obtain are in good agreement with the values found in the literature. Our results show that the performance of the parallel tempering technique is comparable to more powerful heuristics developed to find the ground state of Ising spin glass systems.Comment: 30 pages, 17 figures. A new section added. Accepted for publication in Physica

A new method for analyzing ground-state landscapes: ballistic search

A ``ballistic-search'' algorithm is presented which allows the identification of clusters (or funnels) of ground states in Ising spin glasses even for moderate system sizes. The clusters are defined to be sets of states, which are connected in state-space by chains of zero-energy flips of spins. The technique can also be used to estimate the sizes of such clusters. The performance of the method is tested with respect to different system sizes and choices of parameters. As an application the ground-state funnel structure of two-dimensional +or- J spin glasses of systems up to size L=20 is analyzed by calculating a huge number of ground states per realization. A T=0 entropy per spin of s_0=0.086(4)k_B is obtained.Comment: 10 pages, 11 figures, 35 references, revte

Untersuchung zur Qualität der Diagnostik bei Endometriose zur Verkürzung der Diagnosezeit

Endometriosis is the second most common benign gynaecological disease. It is estimated, that 10-15 % of the female population suffer from endometriosis and it takes an average of 6 years (3 years for acyesis patients and up to 10 years for patients with pain) from the onset of the symptoms until a diagnosis is made (Schweppe et al., 2003). The consequences of such a long delay from onset to diagnosis are a considerable loss in quality of life and performance, drastic treat-ments and high costs for the health system. Early detection of the disease could help reduce morbidity, improve the chances of better and less drastic therapies and reduce costs. This could be achieved by optimizing the diagnostic steps and better interdisciplinary cooperation. Extensive treatment is possible in certified clinics for endometrioses. It would also be helpful if information about this disease could be improved and made available for doctors from other specialties and the population.Endometriose ist die zweithäufigste benigne gynäkologische Erkrankung. Man geht davon aus, dass 10-15 % aller Frauen davon betroffen sind. Das Zeitintervall von Beginn der Beschwerden bis zur Diagnose dauert durchschnittlich 6 Jahre (bei Sterilitätspatientinnen 3 Jahre, bei Schmerzpatientinnen bis zu 10 Jahren) (Schweppe et al., 2003). Die Folgen solch einer langen Diagnosezeit sind beträchtliche Einbußen in der Lebensqualität und Leistungsfähigkeit der Frauen, drastische Behandlungsformen und hohe Kosten für das Gesundheitssystem.Ein frühzeitiges Erkennen der Erkrankung könnte zur Senkung der Morbidität beitragen, bessere und weniger drastische Therapieoptionen möglich machen und die Kosten senken. Dies könnte durch eine Optimierung der Diagnoseschritte und eine bessere interdisziplinäre Zusammenarbeit erzielt werden. Eine umfassende Behandlung ist in zertifizierten Endometriosezentren möglich. Zudem müsste die Information über diese Erkrankung, für Ärzte anderer Fachdisziplinen und die Bevölkerung verbessert werden

Scaling of stiffness energy for 3d +/-J Ising spin glasses

Large numbers of ground states of 3d EA Ising spin glasses are calculated for sizes up to 10^3 using a combination of a genetic algorithm and Cluster-Exact Approximation. A detailed analysis shows that true ground states are obtained. The ground state stiffness (or domain wall) energy D is calculated. A D ~ L^t behavior with t=0.19(2) is found which strongly indicates that the 3d model has an equilibrium spin-glass-paramagnet transition for non-zero T_c.Comment: 4 pages, 4 figure

Dynamics of the Wang-Landau algorithm and complexity of rare events for the three-dimensional bimodal Ising spin glass

We investigate the performance of flat-histogram methods based on a multicanonical ensemble and the Wang-Landau algorithm for the three-dimensional +/- J spin glass by measuring round-trip times in the energy range between the zero-temperature ground state and the state of highest energy. Strong sample-to-sample variations are found for fixed system size and the distribution of round-trip times follows a fat-tailed Frechet extremal value distribution. Rare events in the fat tails of these distributions corresponding to extremely slowly equilibrating spin glass realizations dominate the calculations of statistical averages. While the typical round-trip time scales exponential as expected for this NP-hard problem, we find that the average round-trip time is no longer well-defined for systems with N >= 8^3 spins. We relate the round-trip times for multicanonical sampling to intrinsic properties of the energy landscape and compare with the numerical effort needed by the genetic Cluster-Exact Approximation to calculate the exact ground state energies. For systems with N >= 8^3 spins the simulation of these rare events becomes increasingly hard. For N >= 14^3 there are samples where the Wang-Landau algorithm fails to find the true ground state within reasonable simulation times. We expect similar behavior for other algorithms based on multicanonical sampling.Comment: 9 pages, 12 figure

Consciência fonológica na alfabetização : o que dizem a BNCC e a PNA

Este Trabalho de Conclusão do Curso de Licenciatura em Pedagogia foi elaborado a partir de uma pesquisa bibliográfica acerca da relação entre o desenvolvimento da consciência fonológica (CF) e o processo de alfabetização, considerando os documentos oficiais da Base Nacional Comum Curricular (BNCC) e a Política Nacional de Alfabetização (PNA). A consciência fonológica é a capacidade de refletir sobre os sons da língua. Sendo assim, o objetivo do presente trabalho visa analisar e compreender de que forma a consciência fonológica contribui no processo de alfabetização e o que dizem esses documentos oficiais sobre o assunto. Conforme a BNCC, a análise descreve as habilidades relacionadas à consciência fonológica de acordo com seus níveis em cada ano da alfabetização: 1º e 2º ano. Já a PNA apresenta a consciência fonológica como componente necessário para a alfabetização. A presente pesquisa concluiu que o desenvolvimento da consciência fonológica se revela como grande aliado para o sucesso na aprendizagem da escrita e da leitura. Os documentos oficiais da BNCC e da PNA apontaram a consciência fonológica como uma habilidade metalinguística fundamental no ciclo de alfabetização.Resumo em língua estrangeira não disponíve

A new chronology for the Moon and Mercury

In this paper we present a new method for dating the surface of the Moon, obtained by modeling the incoming flux of impactors and converting it into a size distribution of resulting craters. We compare the results from this model with the standard chronology for the Moon showing their similarities and discrepancies. In particular, we find indications of a non-constant impactor flux in the last 500 Myr and also discuss the implications of our findings for the Late Heavy Bombardment hypothesis. We also show the potential of our model for accurate dating of other inner Solar System bodies, by applying it to Mercury.Comment: 27 pages, 13 figures, 1 table; accepted by A

Ordered phase in the two-dimensional randomly coupled ferromagnet

True ground states are evaluated for a 2d Ising model with random near neighbor interactions and ferromagnetic second neighbor interactions (the Randomly Coupled Ferromagnet). The spin glass stiffness exponent is positive when the absolute value of the random interaction is weaker than the ferromagnetic interaction. This result demonstrates that in this parameter domain the spin glass like ordering temperature is non-zero for these systems, in strong contrast to the 2d Edwards-Anderson spin glass.Comment: 7 pages; 9 figures; revtex; new version much extende

Nephrotic syndrome associated with toxoplasmosis: report of seven cases

The concomitance of nephrotic syndrome and acute infection by Toxoplasma gondii is a rare occurrence in humans. In this paper seven cases of children, ranging from 11 months to 7 year-old, with concomitant nephrotic syndrome and asymptomatic acute T. gondii infection are reported. In one of those patients only the administration of anti-Toxoplasma therapy was enough to control the clinical and laboratory manifestations of the disease. In the other patients it was necessary to introduce corticosteroids or other immunosuppressant drugs. Three patients had complete clinical and laboratory improvement and the remaining showed only a partial response.Ocorrência concomitante de síndrome nefrótica e infecção aguda por Toxoplasma gondii em seres humanos é situação pouco frequente. No presente trabalho são relatados sete casos de crianças, com idade variável entre 11 meses e sete anos, que apresentavam síndrome nefrótica e infecção aguda por T. gondii assintomática. Em um dos pacientes o tratamento específico anti-Toxoplasma foi suficiente para controlar clínica e laboratorialmente as manifestações da doença. Nos demais foi preciso administrar corticosteróides ou outras drogas imunossupressoras. Após introdução desse esquema três pacientes apresentaram remissão completa dos sintomas; os demais apenas remissão parcial

Canine vaccination in Germany: A survey of owner attitudes and compliance

Background: Vaccination is the most important preventive measure for protection against infectious diseases in humans and companion animals. Nevertheless, scepticism about the safety and importance of vaccines is increasing in human and in veterinary medicine. Although owner attitudes towards vaccination have been investigated in cats, there are no similar studies in dogs. The goals of this study were therefore to investigate the vaccination status of dogs in Germany, to determine owner compliance with vaccination and to identify factors that play a role in owners' decisions to have their dogs vaccinated. Methods Data were collected from August 2018 to February 2019 using an online survey targeting dog owners in Germany. A total of 3,881 questionnaires were evaluated, and factors associated with the vaccination status of dogs were determined by a linear logistic regression model using Akaike information criterion. Cohen's kappa statistic was used to evaluate agreement between questionnaire and 340 vaccination passports submitted voluntarily by owners. Results: A total of 46.8% (n = 1,818/3,881) of dogs were vaccinated with core vaccines according to current guidelines with the lowest vaccination rate for leptospirosis (50.1%;n = 1,941/3,874). Dog's age (16 weeks to 15 months) (odds ratio (OR): 3.08;95% CI: 2.05-4.68), type (working dog) (OR: 2.06;95% CI: 1.22-3.53) and travelling abroad within previous 36 months (OR: 1.82;95% CI: 1.12-2.96) had the strongest 'positive' association with the vaccination status. Recommendation from a veterinarian not to vaccinate against leptospirosis had the strongest 'negative' association (OR: 0.08;95% CI: 0.04-0.18). Conclusion The study revealed a need for improvement in vaccination compliance because of inadequate vaccination coverage, especially for leptospirosis, in dogs. Factors influencing owner compliance were numerous. Vaccination recommendations made by the veterinarian had a strong association with the vaccination status and should be used to increase canine vaccination rates