The UV/H2O2 - photodegradation of poly(ethyleneglycol) and model compounds

The general mechanism for the photodegradation of polyethyleneglycol (PEG) by H2O2/UV was determined studying the photooxidation of small model molecules, like low molecular weight ethyleneglycols (tetra-, tri-, di-, and ethyleneglycol). After 30 min of irradiation the average molar mass (Mw) of the degradated PEG, analysed by GPC, fall to half of its initial value, with a concomitant increase in polydispersitivity and number of average chain scission (S), characterizing a random chain scission process yielding oligomers and smaller size ethyleneglycols. HPLC analysis of the photodegradation of the model ethyleneglycols proved that the oxidation mechanism involved consecutive reactions, where the larger ethyleneglycols gave rise, successively, to smaller ones. The photodegradation of ethyleneglycol lead to the formation of low molecular weight carboxylic acids, like glycolic, oxalic and formic acids.

Trabalho multiprofissional: representações em um serviço público de saúde municipal

Este estudo tem como objetivo conhecer as representações sociais dos profissionais de saúde sobre o trabalho multiprofissional no Serviço Público de Saúde no município de Bandeirantes, Paraná. Foram entrevistados 44 profissionais de saúde de nível superior, com quatro questões abertas que abordaram aspectos de interesse para o tema. Para a análise dos dados, tomou-se como base o referencial da Teoria da Representação Social. Para o processamento dos dados, utilizou-se a técnica do Discurso do Sujeito Coletivo, por meio da qual se construíram os discursos-sínteses com auxílio do programa Qualiquantisoft. Nos discursos obtidos, os profissionais de saúde entrevistados consideraram seu trabalho uma rotina de atendimento programado, determinado pela demanda, desgastante, porém vocacionado. Destacaram que o trabalho multiprofissional é a integração de vários campos da área da saúde, entre profissionais de outras áreas e de outras especialidades para ter uma equipe formada para solucionar os problemas. Relataram que, para o desenvolvimento do trabalho multiprofissional, seria necessária maior interação entre os gestores e os profissionais; recursos materiais e físicos para a melhoria do atendimento; capacitação, conscientização, contratação de profissionais para o serviço; remuneração salarial e organização do serviço de saúde. Os conteúdos revelaram barreiras para o desenvolvimento do trabalho multiprofissional, como ausência de novas formas de gestão, flexibilização das relações de trabalho e necessidade de resolução de questões antigas, como remuneração salarial, planos de cargos e carreiras, e organização do serviço, com instalação de mecanismos que possam evitar a intensa rotatividade de profissionais.

Entre a frieza, o cálculo e a "vida loka": violência e sofrimento no trajeto de um adolescente em cumprimento de medida socioeducativa

O conceito de sofrimento social caracteriza-se pela compreensão das situações de aflição e dor como experiências sociais e não como problemas individuais. Este trabalho analisa a natureza social e política do sofrimento de um adolescente em cumprimento de medida socioeducativa. Inspirado na abordagem de Veena Das, o artigo se apóia em "carne" e discurso para problematizar a relação entre cidadania e segmentos juvenis discriminados, que se manifesta nas ambiguidades das práticas institucionais presentes no fluxo de execução de medidas socioeducativas. O artigo analisa as contradições entre o objetivo institucional de evitar a reincidência de atos infracionais, auxiliando o adolescente a tornar-se um cidadão autônomo, e as narrativas e expressões corporais dos adolescentes durante o cumprimento das medidas. A trajetória aqui descrita leva ao reconhecimento de que o trânsito da medida de internação para as medidas em meio aberto se dá sob a tensão entre o discurso institucional de reorganizar a vida escolar, familiar e comunitária e a experiência cotidiana dos adolescentes, que segue marcada pela constante ameaça policial e pela privação de acessos a bens públicos. O cumprimento de medidas socioeducativas acaba por reforçar entre os adolescentes a aflição de serem socialmente tidos como suspeitos e fugitivos e, consequentemente, a incorporação de um lugar social particular, o de membro do "mundo do crime". O desempenho na vida cotidiana de um "estilo bandido" revela formas de resposta ao discurso dominante no sistema socioeducativo, contexto que indica o paradoxo do Estado brasileiro, que garante uma democracia formal enquanto viola direitos civis.

Dose-response effects of systemic anandamide administration in mice sequentially submitted to the open field and elevated plus-maze tests

The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9% saline, ethyl alcohol, Emulphor® (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.

A fuzzy reed-frost model for epidemic spreading

In this paper, we present a fuzzy approach to the Reed-Frost model for epidemic spreading taking into account uncertainties in the diagnostic of the infection. The heterogeneities in the infected group is based on the clinical signals of the individuals (symptoms, laboratorial exams, medical findings, etc.), which are incorporated into the dynamic of the epidemic. The infectivity level is time-varying and the classification of the individuals is performed through fuzzy relations. Simulations considering a real problem with data of the viral epidemic in a children daycare are performed and the results are compared with a stochastic Reed-Frost generalization

Protein-energy malnutrition alters the C3 complement factor in response to lipopolysaccharide in a murine model

A desnutrição proteico-energética modifica a resistência à infecção, modificando diversos processos fisiológicos, incluindo a hematopoiese e as funções imunológicas. Neste estudo, avaliamos as concentrações séricas do fator C3 e do Sistema Complemento total (CH50) em um modelo no qual camundongos submetidos à desnutrição proteico-energética são estimulados com lipopolissacarídeo (LPS), e avaliamos a celularidade periférica, medular e esplênica. Camundongos Swiss, machos, adultos, com dois meses de idade foram submetidos ao processo de desnutrição proteica com uma dieta contendo 4% de proteína em comparação aos animais controles com uma dieta contendo 20% de proteína. Quando os animais do grupo desnutrido alcançaram aproximadamente 20% de perda de peso, em relação ao inicial, foram inoculados endovenosamente com LPS. As células do sangue, da medula óssea e do baço foram quantificadas, bem como as concentrações circulantes de C3 e CH50 em animais estimulados com LPS. Os animais desnutridos apresentaram anemia e leucopenia, além de redução significativa da celularidade da medula óssea e do baço. Os animais desnutridos apresentaram menor taxa de sobrevivência, bem como das concentrações do fator C3 do complemento e do complemento total em relação aos animais controles. Estes resultados sugerem que animais desnutridos apresentam uma resposta deficiente aos LPS. A síntese menor do complemento pode ser em parte responsável pela imunodeficiência observada. Estes resultados conduzem-nos a inferir que a desnutrição proteico-energética interfere na ativação da resposta imune

The Rg1 allele as a valuable tool for genetic transformation of the tomato 'Micro-Tom' model system

Background: The cultivar Micro-Tom (MT) is regarded as a model system for tomato genetics due to its short life cycle and miniature size. However, efforts to improve tomato genetic transformation have led to protocols dependent on the costly hormone zeatin, combined with an excessive number of steps. Results: Here we report the development of a MT near-isogenic genotype harboring the allele Rg1 (MT-Rg1), which greatly improves tomato in vitro regeneration. Regeneration was further improved in MT by including a two-day incubation of cotyledonary explants onto medium containing 0.4 mu M 1-naphthaleneacetic acid (NAA) before cytokinin treatment. Both strategies allowed the use of 5 mu M 6-benzylaminopurine (BAP), a cytokinin 100 times less expensive than zeatin. The use of MT-Rg1 and NAA pre-incubation, followed by BAP regeneration, resulted in high transformation frequencies (near 40%), in a shorter protocol with fewer steps, spanning approximately 40 days from Agrobacterium infection to transgenic plant acclimatization. Conclusions: The genetic resource and the protocol presented here represent invaluable tools for routine gene expression manipulation and high throughput functional genomics by insertional mutagenesis in tomato.

Change and Aging Senescence as an Adaptation

Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual, and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory: i) competition is between individuals; ii) there is some degree of locality, so quite often competition will be between parents and their progeny; iii) optimal conditions are not stationary, and mutation helps each species to keep competitive. When conditions change, a senescent species can drive immortal competitors to extinction. This counter-intuitive result arises from the pruning caused by the death of elder individuals. When there is change and mutation, each generation is slightly better adapted to the new conditions, but some older individuals survive by chance. Senescence can eliminate those from the genetic pool. Even though individual selection forces can sometimes win over group selection ones, it is not exactly the individual that is selected but its lineage. While senescence damages the individuals and has an evolutionary cost, it has a benefit of its own. It allows each lineage to adapt faster to changing conditions. We age because the world changes.

Multistable behavior above synchronization in a locally coupled Kuramoto model

A system of nearest neighbors Kuramoto-like coupled oscillators placed in a ring is studied above the critical synchronization transition. We find a richness of solutions when the coupling increases, which exists only within a solvability region (SR). We also find that the solutions possess different characteristics, depending on the section of the boundary of the SR where they appear. We study the birth of these solutions and how they evolve when the coupling strength increases, and determine the diagram of solutions in phase space.

Aging and fluctuation-dissipation ratio in a nonequilibrium q-state lattice model

A generalized version of the nonequilibrium linear Glauber model with q states in d dimensions is introduced and analyzed. The model is fully symmetric, its dynamics being invariant under all permutations of the q states. Exact expressions for the two-time autocorrelation and response functions on a d-dimensional lattice are obtained. In the stationary regime, the fluctuation-dissipation theorem holds, while in the transient the aging is observed with the fluctuation-dissipation ratio leading to the value predicted for the linear Glauber model.

EVALUATING VIBRATIONS ON A SMALL-SCALE MODEL OF A TIMBER FOOTBRIDGE

In Brazil, the study of pedestrian-induced vibration on footbridges has been undertaken since the early 1990s, for concrete and steel footbridges. However, there are no recorded studies of this kind for timber footbridges. Brazilian code ABNT NBR 7190 (1997) gives design requirements only for static loads in the case of timber footbridges, without considering the serviceability limit state from pedestrian-induced vibrations. The aim of this work is to perform a theoretical dynamic, numerical and experimental analysis on simply-supported timber footbridges, by using a small-scale model developed from a 24 m span and 2 m width timber footbridge, with two main timber beams. Span and width were scaled down (1:4) to 6 m e 0.5 in, respectively. Among the conclusions reached herein, it is emphasized that the Euler-Bernoulli beam theory is suitable for calculating the vertical and lateral first natural frequencies in simply-supported timber footbridges; however, special attention should be given to the evaluation of lateral bending stiffness, as it leads to conservative values.

Parametric model for the analysis of concrete expansion due to alkali-aggregate reaction

The alkali-aggregate reaction (AAR) is a chemical reaction that provokes a heterogeneous expansion of concrete and reduces important properties such as Young's modulus, leading to a reduction in the structure's useful life. In this study, a parametric model is employed to determine the spatial distribution of the concrete expansion, combining normalized factors that influence the reaction through an AAR expansion law. Optimization techniques were employed to adjust the numerical results and observations in a real structure. A three-dimensional version of the model has been implemented in a finite element commercial package (ANSYS(C)) and verified in the analysis of an accelerated mortar test. Comparisons were made between two AAR mathematical descriptions for the mechanical phenomenon, using the same methodology, and an expansion curve obtained from experiment. Some parametric studies are also presented. The numerical results compared very well with the experimental data validating the proposed method.

Architecture for machining process and production monitoring based in open computer numerical control

This paper proposes an architecture for machining process and production monitoring to be applied in machine tools with open Computer numerical control (CNC). A brief description of the advantages of using open CNC for machining process and production monitoring is presented with an emphasis on the CNC architecture using a personal computer (PC)-based human-machine interface. The proposed architecture uses the CNC data and sensors to gather information about the machining process and production. It allows the development of different levels of monitoring systems with mininium investment, minimum need for sensor installation, and low intrusiveness to the process. Successful examples of the utilization of this architecture in a laboratory environment are briefly described. As a Conclusion, it is shown that a wide range of monitoring solutions can be implemented in production processes using the proposed architecture.

Contribution margin model applied to the marketing planning of a container liner carrier

The implementation of confidential contracts between a container liner carrier and its customers, because of the Ocean Shipping Reform Act (OSRA) 1998, demands a revision in the methodology applied in the carrier's planning of marketing and sales. The marketing and sales planning process should be more scientific and with a better use of operational research tools considering the selection of the customers under contracts, the duration of the contracts, the freight, and the container imbalances of these contracts are basic factors for the carrier's yield. This work aims to develop a decision support system based on a linear programming model to generate the business plan for a container liner carrier, maximizing the contribution margin of its freight.

Rumor Propagation Model: An Equilibrium Study

Compartmental epidemiological models have been developed since the 1920s and successfully applied to study the propagation of infectious diseases. Besides, due to their structure, in the 1960s an interesting version of these models was developed to clarify some aspects of rumor propagation, considering that spreading an infectious disease or disseminating information is analogous phenomena. Here, in an analogy with the SIR (Susceptible-Infected-Removed) epidemiological model, the ISS (Ignorant-Spreader-Stifler) rumor spreading model is studied. By using concepts from the Dynamical Systems Theory, stability of equilibrium points is established, according to propagation parameters and initial conditions. Some numerical experiments are conducted in order to validate the model.