Revisiting the S-matrix approach to the open superstring low energy effective lagrangian

The conventional S-matrix approach to the (tree level) open string low energy effective lagrangian assumes that, in order to obtain all its bosonic ${\alpha'}^N$ order terms, it is necessary to know the open string (tree level) $(N+2)$-point amplitude of massless bosons, at least expanded at that order in $\alpha'$. In this work we clarify that the previous claim is indeed valid for the bosonic open string, but for the supersymmetric one the situation is much more better than that: there are constraints in the kinematical bosonic terms of the amplitude (probably due to Spacetime Supersymmetry) such that a much lower open superstring $n$-point amplitude is needed to find all the ${\alpha'}^N$ order terms. In this `revisited' S-matrix approach we have checked that, at least up to ${\alpha'}^4$ order, using these kinematical constraints and only the known open superstring 4-point amplitude, it is possible to determine all the bosonic terms of the low energy effective lagrangian. The sort of results that we obtain seem to agree completely with the ones achieved by the method of BPS configurations, proposed about ten years ago. By means of the KLT relations, our results can be mapped to the NS-NS sector of the low energy effective lagrangian of the type II string theories implying that there one can also find kinematical constraints in the $N$-point amplitudes and that important informations can be inferred, at least up to ${\alpha'}^4$ order, by only using the (tree level) 4-point amplitude.Comment: 34 pages, 3 figure, Submitted on Aug 4, 2012, Published on Oct 15, 201

Efeito do sexo e da gestação sobre os níveis séricos de frutosamina de indivíduos normais

A frutosamina é um índice do controle metabólico no diabete mélito, refletindo as variações da glicemia nas últimas 2-3 semanas. Representa um conjunto de proteínas glicosadas, cuja fração principal é a albumina. Com o objetivo de es tabelecer os valotes normais da frutosamina em homens, mulheres e gestantes, os níveis séricos de frutosamina forilm medidos em 42 indivíduos normais (homens, n=21, idades 24-81 anos; mulheres, n=21, idades 22-71 anos) e 36 gestantes (idades 18-38 anos, idade gestacional 17-37 semanas). A frutosamina foi medida pelo método colorimétTico em um analisador automático COBAS MIRA-ROCHE. Os valores de frutosamina (média ± desvio padrão) observados em homens (2,99 ± 0.32 mmoljl) foram maiores do que nas mulheres (2,70 ± 0.26 mmol/1). Os valores nom1ais nas gestantes foram menores (2.40 ± 0.22 mmoljl) do que nas mulheres não-grávidas e a correção di! frutosamina de acordo com os túveis de albumina sérica não modificaram os resultados. Os dados apresentados indicam que devem ser considemdos o sexo ea presença ou não de gravidez pam se definir os limites normais dos valores de frutosamina sérica.Serum fructosamine is an index of metabolic control in diabetes mellitus, reflecting the glucose variations during the last 2-3 weeks. It represents a group of glycated proteins, in which the main fraction is albumin. The aim of this study was to determine the normal values in men, women and pregnants. Serum fructosamine was measured in 42healthy subjects (men n=21, aged 24-81 years; women n=21, aged 22-71years) and 36 normal pregnants (aged 18-38 years; gestacional age 17-37weeks). The fructosamine was determined by colorimetric method in an auto-analyser COBAS MIRA-ROCHE. The normal values (mean ± standard deviation) observed in men (2,99 ± 0,32 mmol/L)was higher than women (2,70 ± 0.26 mmol/L). The normal values in pregnants (2.40 ± 0.22mmol/L) were lower than non-pregnant women and the values were not dependent on serum albumin concentration. This data indicated the sex and pregnancy should be taken in account in order to establish the normal range of serum fructosamine

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Cervical lymph node metastasis in adenoid cystic carcinoma of the larynx: a collective international review

Adenoid cystic carcinoma (AdCC) of the head and neck is a well-recognized pathologic entity that rarely occurs in the larynx. Although the 5-year locoregional control rates are high, distant metastasis has a tendency to appear more than 5 years post treatment. Because AdCC of the larynx is uncommon, it is difficult to standardize a treatment protocol. One of the controversial points is the decision whether or not to perform an elective neck dissection on these patients. Because there is contradictory information about this issue, we have critically reviewed the literature from 1912 to 2015 on all reported cases of AdCC of the larynx in order to clarify this issue. During the most recent period of our review (1991-2015) with a more exact diagnosis of the tumor histology, 142 cases were observed of AdCC of the larynx, of which 91 patients had data pertaining to lymph node status. Eleven of the 91 patients (12.1%) had nodal metastasis and, based on this low proportion of patients, routine elective neck dissection is therefore not recommended