The Maunder minimum (1645-1715) was indeed a grand minimum: a reassessment of multiple datasets

Aims. Although the time of the Maunder minimum (1645–1715) is widely known as a period of extremely low solar activity, it is still being debated whether solar activity during that period might have been moderate or even higher than the current solar cycle (number 24). We have revisited all existing evidence and datasets, both direct and indirect, to assess the level of solar activity during the Maunder minimum. Methods. We discuss the East Asian naked-eye sunspot observations, the telescopic solar observations, the fraction of sunspot active days, the latitudinal extent of sunspot positions, auroral sightings at high latitudes, cosmogenic radionuclide data as well as solar eclipse observations for that period. We also consider peculiar features of the Sun (very strong hemispheric asymmetry of the sunspot location, unusual differential rotation and the lack of the K-corona) that imply a special mode of solar activity during the Maunder minimum. Results. The level of solar activity during the Maunder minimum is reassessed on the basis of all available datasets. Conclusions. We conclude that solar activity was indeed at an exceptionally low level during the Maunder minimum. Although the exact level is still unclear, it was definitely lower than during the Dalton minimum of around 1800 and significantly below that of the current solar cycle #24. Claims of a moderate-to-high level of solar activity during the Maunder minimum are rejected with a high confidence level.

Quantum States Allowing Minimum Uncertainty Product of phi and L(z)

We provide necessary and sufficient conditions for states to have an arbitrarily small uncertainty product of the azimuthal angle phi and its canonical moment L(z). We illustrate our results with analytical examples.

Minimum cycle cover and Chinese postman problems on mixed graphs with bounded tree-width

Let M = (V, E, A) be a mixed graph with vertex set V, edge set E and arc set A. A cycle cover of M is a family C = {C(1), ... , C(k)} of cycles of M such that each edge/arc of M belongs to at least one cycle in C. The weight of C is Sigma(k)(i=1) vertical bar C(i)vertical bar. The minimum cycle cover problem is the following: given a strongly connected mixed graph M without bridges, find a cycle cover of M with weight as small as possible. The Chinese postman problem is: given a strongly connected mixed graph M, find a minimum length closed walk using all edges and arcs of M. These problems are NP-hard. We show that they can be solved in polynomial time if M has bounded tree-width. (C) 2008 Elsevier B.V. All rights reserved.

Glucose-induced heat production, insulin secretion and lactate production in isolated Wistar rat pancreatic islets

Transplantation of pancreatic islets is efficient in improving the metabolic control and quality of life and in preventing severe hypoglycemia in patients with brittle type I diabetes mellitus. More accurate methods to assess islet viability would be extremely useful in designing target interventions for islet cytoprorection and in reducing the number of islets required to achieve insulin independence. Here we report on an application of calorimetry to evaluate the metabolic response of pancreatic islets to glucose stimulation. A significant increase in metabolic heat was produced by islet samples when consecutively subjected to 2.8 and 16.3 mmol L-1 glucose. Under these glucose concentrations, 1000 islets released average heat values of 9.16 +/- 0.71 mJ and 14.90 +/- 1.21 mJ over 50 min, respectively. Additionally, the glucose stimulation indexes were 1.67 +/- 0.30 for insulin. 1.72 +/- 0.13 for heat and 2.91 +/- 0.50 for lactate, raising the important possibility of substituting the secreted insulin index/ratio by the index/ratio of the heat released in the evaluation of Langerhans islets viability for transplantation. Altogether, Our results demonstrate the applicability of calorimetry to assess the quality of isolated pancreatic islets and to study vital islet functions. (c) 2008 Published by Elsevier B.V.

New material for orthopedic implants: Electrochemical study of nickel free P558 stainless steel in minimum essential medium

Nickel, a component of stainless steels (SS) applied in orthopedic implants may cause allergic processes in human tissues P558 nickel free SS was studied to verify its viability as a substitute for stainless steel containing nickel Its performance is compared to ISO 5832-9 and F138 most used nowadays grades in implants fabrications, in minimum essential medium. MEM, at 37 degrees C. Potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and ""in vitro"" cytotoxicity were used as techniques. From the electrochemical point of view P558 SS is comparable to ISO 5832-9 SS in MEM It remains passivated until the transpassivation potential, above which generalized corrosion occurs F138 presents pitting corrosion at 370 mV/SCE. The cytotoxicity results showed that P558. ISO 5832-9 and F138 do not present cytotoxic character Therefore, these results suggest that P558 SS can be applied in orthopedic implants (C) 2010 Elsevier BV All rights reserved

Comparative electrochemical study of 5832-9 stainless steel at different media of biological interest

The electrochemical behavior of ISO 5832-9 stainless steel at 37 degrees C in 0.9% NaCl, Ringer Lactate and minimum essential medium (MEM) has been studied, using linear voltammetry, and surface analysis by SEM and EDS. Mechanical and toxicity tests were made. ISO 5832-9 is passivated at corrosion potential (E) and it does not present pitting corrosion on the media studied from to 50 in V above the transpassivation potential (Ei). SEM and EDS analysis have shown that the sample previously immersed in MEM presents a diffirent behavior at 50 in V above El: the manganese oxide inclusions are absent in the surface. E. values and passivation current density values j(pass) changed according to the following. E(corr, RL) < E(corr,NaCl) < E(corr, MEM) and J (MEM) << j(RL) congruent to j(NaCl) The stainless steel was characterized as non toxic in the cytotoxicity assay

Effects of melatonin on hemolymph glucose and lactate concentrations in the fiddler crab, uca pugilator

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine hormone produced by the pineal gland that works to regulate sleep/wake cycles and activity rhythms. The effects of melatonin in metabolism are far from understood. Melatonin was injected into the fiddler crab, Uca pugilator, to investigate the effects of melatonin on hemolymph glucose and lactate levels. Following injection at t=O, hemolymph samples were collected at t=O.5, 1.0, 1.5 and 5.0 hours. Melatonin caused a decrease in the stress response to injection and also caused delayed hyperglycemia. Melatonin-injected crabs also retained the glucose and lactate rhythymicity when compared to saline-injected crabs. Glucose and lactate rhythms followed the same pattern indicating that the cycles are coupled. Also, melatonin was synthesized using tbe Fischer Indole synthesis and characterized using H?NMR. The synthetic melatonin demonstrated biological activity when injected into the crabs as when compared to pure melatonin on the effects on glucose and lactate concentrations. Overall, melatonin influences both glucose metabolism and the production of lactate.

The effects of the minimum wage on earnings and employment in Brazil

This paper analyzes the effects of the mlmmum wage on both, eammgs and employment, using a Brazilian rotating panel data (Pesquisa Mensal do Emprego - PME) which has a similar design to the US Current Population Survey (CPS). First an intuitive description of the data is done by graphical analysis. In particular, Kemel densities are used to show that an increase in the minimum wage compresses the eamings distribution. This graphical analysis is then forrnalized by descriptive models. This is followed by a discussion on identification and endogeneity that leads to the respecification of the model. Second, models for employment are estimated, using an interesting decomposition that makes it possible to separate out the effects of an increase in the minimum wage on number of hours and on posts of jobs. The main result is that an increase in the minimum wage was found to compress the eamings distribution, with a moderately small effect on the leveI of employment, contributing to alleviate inequality.

Higher salaries, more teaching, better performance? The effects of the introduction of the minimum salary for teachers in Brazil

De acordo com a literatura empírica, há fortes evidências de que, após o controle de características socioeconômicas dos alunos, a qualidade dos professores é o fator mais importante para explicar o desempenho do aluno em testes padronizados. No entanto, não há consenso sobre como sistemas públicos de ensino podem melhorar a qualidade dos professores. Será que o pagamento de salários mais elevados a professores da rede pública impactam a qualidade dos professores nas escolas públicas? O Governo Federal brasileiro introduziu, em 2009, piso salarial nacional para os professores de escolas públicas, provocando um perceptível aumento exógeno dos salários dos professores municipais. O principal objetivo desta tese é avaliar os impactos de curto prazo da elevação linear e incondicional do salário do professor na qualidade da educação. Devido à ausência de dados secundários sobre o valor do salário-base de professores entre 2008 e 2013, tivemos que realizar um levantamento com as Secretarias Municipais de Educação para reunir informação sobre a estrutura da carreira docente e sobre os salários-bases nesse período. Com base em nossa pesquisa de campo, o primeiro capítulo investiga a conformidade dos sistemas municipais de ensino ao piso salarial nacional para professores de redes públicas. Encontramos que fatores não observáveis/observados são determinantes para explicar a variabilidade salarial verificada entre os municípios e o cumprimento da lei, o que embasa nossa estratégia de identificação com base em métodos de diferença em diferenças, combinados com pareamento com base em escore de propensão. O segundo capítulo centra-se na estimativa do impacto da elevação dos salários dos professores sobre a proficiência dos alunos de 5º ano do ensino fundamental municipal. De acordo com estes resultados, o aumento salarial incondicional não gerou uma expansão da proficiência escolar dos alunos, pelo menos no curto prazo. Embora não tenham sido detectados impactos na aprendizagem dos alunos, alguns mecanismos de transmissão do aumento salarial para melhores resultados educacionais podem já ter sido ativados. Assim, o principal objetivo do terceiro capítulo é avaliar o impacto dos aumentos de salário sobre a qualidade dos professores atuais e dos potenciais futuros professores. Avaliamos o impacto de aumentos de salário sobre o desempenho dos professores no ENADE, uma proxy de sua qualidade, e sobre a atratividade dos cursos de ensino superior associados à carreira docente. Essa atratividade é medida por meio da qualidade dos que entram nos respectivos cursos superiores, de acordo com seu desempenho no Enem. Neste último capítulo, aplicamos modelo de Tripla-Diferenças visando controlar dois tipos de potenciais fatores de confusão: (i) mudanças no desempenho dos professores (potenciais futuros professores) entre grupos de municípios, que foram submetidos ao tratamento e os que não foram tratados, que nada têm a ver com a política; e (ii) as alterações no desempenho de todos os professores (alunos) que vivem no município em que houve a elevação salarial devido à introdução da lei. As estimativas obtidas indicam que a elevação salarial gerou efeitos leves sobre a qualidade dos professores e sobre a atratividade dos cursos relacionados à carreira docente.

Effects of butorphanol on the minimum anesthetic concentration for sevoflurane in guineafowl (Numida meleagris)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)