bluuebunny/crossref_metadata_2025 huggingface dataset:
A link between Notch and progesterone maintains the functionality of the rat corpus luteum
Authors: Accialini P , Hernández S F , Bas D , Pazos M C , Irusta G , Abramovich D , Tesone M
Published: November 2014

In this study, we investigated the interaction between the Notch pathway and progesterone to maintain the functionality of the corpus luteum (CL). When Notch signaling is activated, the γ-secretase complex releases the active intracellular domains (NICD) of their receptors, which exert survival effects. We designed studies to analyze whether thein vitroinhibition of Notch affects progesterone production, steroidogenic regulators, apoptotic parameters, and signaling transduction pathways in the cultures of CL isolated from pregnant and superovulated rats. We detected a decrease in progesterone production when corpora lutea (CL) were incubated withN-(N-(3,5-difluorophenacetyl-l-alanyl))-S-phenylglycine t-butyl ester (DAPT), a γ-secretase inhibitor. This effect could be in part due to the decrease detected in the CL protein levels of P450scc because STAR and 3β-hydroxysteroid dehydrogenase were not affected by Notch inhibition. Besides, the addition of aminoglutethimide to the CL culture medium decreased NICD of NOTCH1. We observed an increase in the expression of active CASPASE3 (CASP3) after inhibition by Notch, which was reversed by the presence of progesterone. The BAX:BCLXLratio was increased in CL treated with DAPT and the presence of progesterone reversed this effect. In addition, phosphorylation of AKT was inhibited in CL treated with DAPT, but had no effect on ERK activation. To demonstrate that the action of DAPT is specifically related with the inhibition of Notch, CLs were incubated with DLL4 antibody and a decrease in progesterone production was detected. These results suggest the existence of a novel link between progesterone and the Notch signaling pathway to maintain the functionality of the CL.
Structural Evolution Properties of Cu-25 wt %Sn Alloy During Ball Milling
Authors: Hüseyin Arslan
Published: December 2014

In the present study, Cu-25 wt %Sn alloy samples were prepared by the mechanical alloying process using planetary high-energy ball mill. The alloy formation and different physical properties associated with their formations were investigated as a function of milling times of 0, 10, 20, 70, 80, 100, 120, 150 and 200 h by means of the x-ray diffraction (XRD) technique, scanning electron microscopy (SEM) and differential scanning calorimeter (DSC). After milling time of 80 h, the complete formation of martensite transformation is observed. When milling time increases from 70 to 120 h, the grain size decreases from 20.8 to 8.6 nm, while the strain increases from 4.73 % to 7.59 %. It is inferred that the martensite volume fraction increases from 30 to 55 % when milling time increases from 20 to 200 h. Moreover, by using SEM the grain morphologies at different formation stages during ball milling are observed.
Early Weight Loss Nomograms for Exclusively Breastfed Newborns
Authors: Flaherman Valerie J. , Schaefer Eric W. , Kuzniewicz Michael W. , Li Sherian X. , Walsh Eileen M. , Paul Ian M.
Published: December 2014

BACKGROUND:

The majority of newborns are exclusively breastfed during the birth hospitalization, and weight loss is nearly universal for these neonates. The amount of weight lost varies substantially among newborns with higher amounts of weight loss increasing risk for morbidity. No hour-by-hour newborn weight loss nomogram exists to assist in early identification of those on a trajectory for adverse outcomes.

METHODS:

For 161 471 term, singleton neonates born at ≥36 weeks’ gestation at Northern California Kaiser Permanente hospitals in 2009–2013, data were extracted from the birth hospitalization regarding delivery mode, race/ethnicity, feeding type, and weights from electronic records. Quantile regression was used to create nomograms stratified by delivery mode that estimated percentiles of weight loss as a function of time among exclusively breastfed neonates. Weights measured subsequent to any nonbreastmilk feeding were excluded.

RESULTS:

Among this sample, 108 907 newborns had weights recorded while exclusively breastfeeding with 83 433 delivered vaginally and 25 474 delivered by cesarean. Differential weight loss by delivery mode was evident 6 hours after delivery and persisted over time. Almost 5% of vaginally delivered newborns and >10% of those delivered by cesarean had lost ≥10% of their birth weight 48 hours after delivery. By 72 hours, >25% of newborns delivered by cesarean had lost ≥10% of their birth weight.

CONCLUSIONS:

These newborn weight loss nomograms demonstrate percentiles for weight loss by delivery mode for those who are exclusively breastfed. The nomograms can be used for early identification of neonates on a trajectory for greater weight loss and related morbidities.
Stability of cylindrical panel with variable thickness
Authors: Luong Nguyen Thi Hien , Hoach Thach Som So
Published: December 2014

A linear buckling analysis based on the small deflection theory is presented for the cylindrical panel with sinusoidal changes in the shell thickness. The buckling load for simply supported cylindrical panel around the periphery is defined by using the hybrid perturbation - Galerkin method. The influence of the thickness variation parameter on the critical loads is investigated.
About an approximate method to solve the static boundary value problems in the isotropic hardening elastic-plastic solid
Authors: Phong Ngo Thanh , Trung Nguyen Thoi , Vinh Nguyen Phu
Published: December 2014

The paper presents the theory, model, weak form, finite element method and return-mapping algorithm for the isotropic hardening elastic-plastic problem. Then applying the algorithm to numerically simulate a variety of plane strain problems.
Calculation of fracture mechanic parameters via FEM for some cracked plates under different loads
Authors: Nhu Ngo Huong , Giang Nguyen Truong
Published: December 2014

This paper describes some results in analyzing cracked plates via FEM based on the procedures in CASTEM 2000 [1]. The basic methods for computing the crack parameters by the finite element analysis are presented. Some programs written by GIBIAN languages to solve problems for cracked plates are given. In possible cases, the numerical results are composed with analytical solution or testing result that gives a good agreement. The influence of plate configurations, the crack length, the external load type on the crack characteristic values are considered. The numerical analysis for inclined crack at angle and in arbitrary position of plate, the crack at hole in the plate, the crack of gravity dams are realized. The given results and programs can be applied to practical problems for controlling the brittle failure state of a structure.
Forced nonlinear vibration of shallow shell and application to technical diagnosis
Authors: Thach Le Ngoc , Lien Tran Van
Published: December 2014

This paper presents direct and inverse problems of forced nonlinear vibration of shallow shell. From that the method of establishment and solution of technical diagnosis for shallow shell under the vibrated load is proposed. The diagnosis criterion is the minimum of the difference between the square of experimental and theoretical data. The diagnosed parameters are the external loads and the reactions arose at the boundaries.
About the Gibbs-Appel equations for multibody systems
Authors: Khang Nguyen Van
Published: December 2014

In this paper a matrix form of Gibbs-Appel function is recommended for multibody dynamics formulations. The form proposed in this paper seems to be more clear and suitable for automatic generation of dynamical equations of motion. The advantages followed from the formulation proposed are illustrated through an example.
Two approximation methods of spatial derivatives on unstructured triangular meshes and their application in computing two dimensional flows
Authors: Lang Nguyen Duc , Lich Tran Gia , Duc Le
Published: December 2014

Two approximation methods (the Green's theorem technique and the directional derivative technique) of spatial derivatives have been proposed for finite differences on unstructured triangular meshes. Both methods have the first order accuracy. A semi-implicit time matching methods beside the third order Adams-Bashforth method are used in integrating the water shallow equations written in both non-conservative and conservative forms. To remove spurious waves, a smooth procedure has been used. The model is tested on rectangular grids triangulari2jed after the 8-neighbours strategy. In the context of the semi-implicit time matching methods, the directional Derivative technique is more accurate than Green's theorem technique. The results from the third order Adams-Bashforth scheme are the most accurate, especially for discontinuous problems. In this case, there is a minor difference between two approximation techniques of spatial derivatives.
Free vibration of prestress Timoshenko beams resting on elastic foundation
Authors: Kien Nguyen Dinh
Published: December 2014

This paper presents a finite element formulation for investigating the free vibration of uniform Timoshenko beams resting on a Winkler-type elastic foundation and prestressing by axial force. Taking the effect of prestress, foundation support and shear deformation into account, a stiffness matrix for Timoshenko-type beam element is formulated using the energy method. The element consistent mass matrix is obtained from the kinetic energy using simple linear shape functions. Employing the formulated element, the natural frequencies of the beams having various boundary conditions are determined for different values of the axial force and foundation stiffness. The vibration Characteristics of the beams partially supported on the foundation are also studied and highlighted. Specially, the effects of shear deformation on the vibration frequencies of prestress beams fully and partially supported on the elastic foundation are investigated in detail.
Spectral proper transformation and application to gust response prediction of structures
Authors: Hoa Le Thai , Anh Nguyen Dong
Published: December 2014

Random turbulent loading on engineering structures which immersed in the atmospheric turbulent flow is often represented as the multi-dimensional and/ or multivariate Gaussian random loading processes. Gust response prediction, however, usually burdens a lot of computational difficulties due to turbulent loading projection on the generalized structural coordinates. In these cases, the decomposition techniques must be required to decouple the multi-variate turbulent loading into the independently generalized turbulent forces, then is associated with the generalized structural modes. This paper will present the proper orthogonal decomposition using the spectral proper transformation in the frequency domain to decouple the multi-variate turbulent loading processes. New approach in the gust response prediction of structures will be formulated with numerical example of cable-stayed bridge.
Orthogonal-based wavelet analysis of wind turbulence and correlation between turbulence and forces
Authors: Hoa Le Thai , Anh Nguyen Dong
Published: December 2014

Recent models of wind turbulence and turbulence-force relation as well still contain uncertainties. Further studies on them are needed to gain the better knowledge to refine the existing problems from analytical computations to wind tunnel's physical simulations in the wind engineering. The continuous and discrete wavelet transforms have been applied as powerful transformation tools to represent time series into the time-frequency localization. This paper will apply the orthogonal-based wavelet decomposition to investigate the intermittency of the turbulence and to detect the turbulence-force correlation in the both temporal-spectral information using proposed cross energy of wavelet decompositions. Analyzing data have been obtained by physical measurements on model from the wind tunnel tests.
Experimental study of radiation heat transfer coefficient of diffusion flames
Authors: Ga Bui Van , Tuy Le Van , Vang Huynh Ba , Lu Le Van , Linh Nguyen Ngoc
Published: December 2014

Basing on analysis of flame pictures given by visioscope by two-color method, the paper presents evolution of radiation heat transfer coefficient \(\varepsilon_s\) of soot in diffusion flames in air, in furnace and in combustion chamber of Diesel engine. \(\varepsilon_s\) reaches respectively its maximal value of 0.15; 0.30 and 0.45 in regions of maximal soot fraction of the three above flames.
Some problems on nonlinear oscillations
Authors: Dao Nguyen Van
Published: December 2014

Special Issue Dedicated to the Memory of Prof. Nguyen Van Dao
Construction of asymptotic in Krylov-Bogoliubov-Mitropolsky sense solution of wave equations
Authors: Mitropolsky Yu. A.
Published: December 2014

The paper in question gives consideration to two examples of KBM method for constructing approximate solutions of Klein-Gordon-Bretherton equations often occurred in practice.
On the technical diagnostics of ball-bearing based on modelling of rotor-bearing systems by vibration method
Authors: Menh Nguyen Cao
Published: December 2014

In this paper, after analysing deformations of loading ball-bearing it is able to investigate vibrations of rotor-bearing system as the system with non-linear and periodically varying stiffness. The modelling of the systems is depent on properties of the shaft (rigid or flexible) and on measurement techniques for system vibrations (by eddy current proximity probe for rotating shaft or on non-rotating parts of the rotor-bearing systems) it can be described by a single degree-of-freedom or two-degree-of freedom nonlinear systems subjected to parametric and external excitations. Therefore it is possible to obtain different characteristics of system vibrations with respect to different defects of ball-bearing. These symptoms help us to identify and estimate the bearing quality by measurement and analysis of system vibrations.
Potential evapotranspiration estimation and its effect on hydrological model response
Authors: Nghi Vu Van , Dung Do Duc , Lam Dang Thanh
Published: December 2014

Potential evapotranspiration can be directly calculated by the Penman-Monteith equation, known as the one-step method. The approach requires data on the land cover and related-vegetation parameters based on AVHRR and LDAS information, which are available in recent years. The Nong Son basin, a sub-catchment of the Vu Gia-Thu Bon basin in the Central Vietnam, is selected for this study. To this end, NAM model was used; the results obtained show that the NAM model has the potential to reproduce the effects of potential evapotranspiration on hydrological response. This is seemingly manifested in the good agreement between model simulation of discharge and the observed at the stream gauge.
Static and dynamic analysis of laminated composite plates with integrated piezoelectrics
Authors: Thinh Tran Ich , Ngoc Le Kim
Published: December 2014

A Finite Element model based on First-order Shear Deformation Theory is developed for the static shape control and vibration control of la minated composite plates integrated with piezoelectric sensors and actuators. A nine-node isoparametric rectangular element with 45 degrees of freedom for the generalized displacements and 2 electrical degrees of freedom is implemented for the static and dynamic analyses. The model is validated by comparing with existing results documented in the literature. Some numerical results are presented. It is concluded that the shape of the piezoelectric laminated composite plates can reach the desired shape through passive control or active control. The influence of stacking sequence of composite plates and position of piezoelectric layers and sensors/actuators patches on the response of the piezoelectric composite plates is evaluated.
Research on manufacturing dry mixed cement mortar with high compressive strength, high flexural strength, low shrinkage and high watertightness for restoration of damaged hydraulic structures in Vietnam
Authors: Phu Nguyen Quang , Uyen Hoang Pho , Hua Jiang Lin , Jiaping Liu
Published: December 2014

Using normal materials to manufacture the mixed mortar is necessary for restoration of hydraulic structures in Vietnam. It will salvage the materials and decreases the cost price of the mortar. In this research, we used cement made in Vietnam (Chinfon - Haiphong cement), natural sand (Lo River sand), polymer acrylic and high range water reducing (of SIKA company)' with proportion 1 : 3 : 0.03 : 0.003 by weight. The water to cement ratio is 0.5, which always ensure the compressive strength of mortar more than 40 MPa and small shrinkage, good watertightness, and high adhesion. That is suitable for the restoration of concrete structures in general and hydraulic structures in particular of Vietnam. The dry mixed mortar is manufactured and in bag of 15±0.5 kg weight.
The error estimate and the convergence rate for h, p - refinement in the finite element analysis
Authors: Son Nguyen Hoai
Published: December 2014

The goal of this study is to further investigate and to develop a more efficient way in the error estimate and the rate of the convergence for the mesh h, p-refinement procedure in the finite element analysis for two-dimensional and three-dimensional elastostatic mechanics problems. The oscillation of the stress field around singularity points is also considered in the refinement process. In this paper, a-refinement procedure with a h-uniform and p-uniform analysis capability is called a h, p-refinement procedure. We also establish the refinement criterion for the adaptive strategy with h-refinement based on the ratio of error indicator or the enrichment indicator.
Non-destructive testing of tennis strings
Authors: Phuong Luong Minh
Published: December 2014

The paper aims to illustrate three advantages of infrared thermography as a non-destructive, non-contact and in real time technique (a) to detect the occurrence of intrinsic dissipation localisation, (b) to observe the progressive damage processes and mechanisms of gut failure, and to determine the optimal tensions for each type of tennis strings. Experimental results evidence a limit of acceptable damage beyond which string will fail due to coalescence of defects and/or weakness zones.
Determining reaction forces in planar mechanisms
Authors: Sanh Do , Phong Dinh Van , Khoa Do Dang , Phong Phan Dang
Published: December 2014

In the paper, it is introduced a method to determine joint reaction forces, constraint forces and internal forces at the cross section of linkages. Based on the principle of compatibility and the ideality of constraints, the methodology is presented to analyze and determine reaction forces in planar mechanisms.
Duality in process of noncommutative deformation and topological nature of Cherepanov-Rice integral
Authors: Khoa Trinh Van
Published: December 2014

In t his paper it is showed, that for the noncommutative deformation simultaneously there exist also loading deformation H, and unloading deformation \(H^v\). The real deformation is a combination of these types of deformations. The criterion of destruction J reflects topological character of medium, i.e. it defines properties of symmetry of medium at destruction. It is possible to tell, that during destruction the energy is released not continuously but and discretely. This situation is reflected through topological number Q or number of unloading, connected to him.
An intermediate asymptotic solution of the coupled creep-damage crack problem in similarity variables
Authors: Stepanova Larisa V.
Published: December 2014

The class of self-similar solutions to coupled (creep-damage) crack problems is considered. The constitutive model is based on continuum damage mechanics. The conventional Kachanov-Rabotnov creep-damage theory is utilized to study the asymptotic behavior of damage in the region very near the crack tip. The totally damaged zone where the damage (integrity) parameter reaches its critical value is assumed to exist in the vicinity of the crack tip. Using the similarity variable the asymptotic solutions to mode I and mode III crack problems are obtained. The asymptotic stress, creep strain rate and damage fields near the crack tip are analyzed by solving nonlinear eigenvalue problems resulting in a new far stress distribution. The configurations of the totally damaged zone governed by the new far stress field are found and analyzed.
An inequality for a quadratic functional
Authors: Chau Le Khanh
Published: December 2014

An inequality is proved for a quadratic functional with the logarithmic kernel. The best constant of this inequality and the corresponding function for which the equality holds are found precisely.
Unilateral contact and damage analysis in masonry arches
Authors: Campo M. , Drosopoulos G. A. , Stavroulakis G. E.
Published: December 2014

In the present work the ultimate failure load and the collapse mechanism of a stone arch bridge are estimated by the usage of (a) a multi - part elastic model with unilateral contact frictional interfaces and (b) a continuous damage model. According to the contact model, contact interfaces simulating potential cracks are considered and their opening or sliding indicates crack initiation. The second model deals with the material damage consisting in the development of internal micro cracks that affect the load bearing capacity of the material. Satisfactory comparison of the results is reported here.
Experimental investigation of friction behavior in pre-sliding regime for pneumatic cylinder
Authors: Bo Tran Xuan , Thang Pham Tat , Cong Do Thanh , Loc Ngo Sy
Published: December 2014

Friction always presents in pneumatic cylinders and causes difficulties in controlling position and velocity of pneumatic systems. In order to improve the control performance of the pneumatic systems, it is necessary to fully understand behavior of friction in the pneumatic cylinders. So far, dynamic friction behavior of pneumatic cylinders has been investigated but mainly focused on the friction behavior in sliding regime. In pre-sliding regime, friction behavior has not been investigated. In this paper, experimental investigations of friction behavior of a pneumatic cylinder in pre-sliding regime are made. The friction force is calculated from the equation of motion of the piston using the measured values of pressures in the two cylinder chambers and the piston displacement. The pressures are controlled by using two proportional pressure control valve. The friction force versus piston displacement characteristics are measured and analysed under various operating conditions of the applied force and the pressures. Experimental results show that: i) the piston motion in pre-sliding regime exhibits a nonlinear spring behavior; ii) hysteretic behavior with nonlocal memory is verified; iii) the pressures have influence only on the size of the hysteretic loop. These experimental results can be applied to develop a friction model for pneumatic cylinders.
Discriminación Salarial Por Género “Efecto Techo De Cristal”. Caso: Siete Áreas Metropolitanas De Colombia
Authors: Chávez Nelson Manolo , Ríos Héctor
Published: December 2014

Este documento pretende determinar la existencia de la discriminación ocupacional de las mujeres “efectotecho de cristal” a través del análisis de un modelo probabilístico para el periodo comprendido entre 1984 y2010, analizando de manera descriptiva los posibles factores que inciden para que las mujeres no alcancenlos cargos directivos que normalmente son ocupados por los hombres. De esta manera, se evalúa el nivel dediscriminación por género en los cargos jerárquicos, estimando un modelo “Probit”, por medio del cual se validóla situación laboral de la mujer en las siete áreas metropolitanas (Manizales, Bogotá, Cali, Bucaramanga,Medellín, Pasto y Barranquilla), y a partir del cual, se logró establecer que existe una barrera invisible explicadapor lo prejuicios del empleador hombre que no permite que la mujer alcance dichos cargos directivos.
Sytuacja demograficzno-społeczna wybranych miast województwa śląskiego w latach 2002 i 2009
Authors: Mielecka-Kubień Zofia , Warzecha Katarzyna
Published: December 2014

The purpose of the research was to determine the similarities that exist among cities in the province of Śląskie with more than 100,000 inhabitants in the interval of a few years. The cities considered were Bielsko-Biała, Bytom, Chorzów, Częstochowa, Dąbrowa  Górnicza, Gliwice, Katowice, Ruda Śląska, Rybnik, Sosnowiec, Tychy and Zabrze, all of which are located within close geographical proximity to one another. The similarity of the cities was analysed according to chosen socio-economic indicators and demographic coefficients in the years 2002 and 2009. J. Czekanowski method was applied; to determine which groups of cities were better or worse off with regard to the given profile of the investigation, the average values of the indicators for the entire set of the cities, and for its established groups were compared. The research was conducted in the following profiles: I - socio-demographic situation, II - population health and its determinants, III - affluence, IV - educational and cultural level. The cities that were the most similar to each other, and in the best socio-economic and demographic situation were, for both years, and in spite of the relatively big geographic distance, Bielsko-Biała and Częstochowa. Bielsko-Biała stood alone among the cities for its affluence. Sosnowiec, Zabrze and Gliwice - all cities in the former Upper-Silesian Industrial District - were similar to each other insofar as they were in the worst situation.
Propozycja modyfikacji wskaźnika ujawnionej przewagi komparatywnej z wykorzystaniem funkcji wymiernych
Authors: Salamaga Marcin
Published: December 2014

The Revealed Comparative Advantage Index (RCA) is used to estimate the export attractiveness and comparative advantage in the country by industry sectors or commodity groups. This measure has many disadvantages because it ranges from 0 to ∞. Its empirical distribution is strongly asymmetric and is not stable in time. The Revealed Comparative Advantage Index distribution is strongly dependent on the number of reference countries, industries and commodity groups taken under consideration. In consequence, some RCA distribution parameters are not stable. These problematic properties make its outcomes impossible to compare across time and space. The paper proposes transforming the RCA measure into a new index, ranging from -1 to 1, by using a special class of rational  unctions. The new measure has a symmetric distribution with a stable mean and is independent of the industry sectors or commodity groups. Empirical distributions of the adjusted RCA index are built on the basis of data on Polish export and import commodities by Standard International Trade Classification (SITC).
Leptin replacement therapy for the treatment of non-HAART associated lipodystrophy syndromes: a meta-analysis into the effects of leptin on metabolic and hepatic endpoints
Authors: Rodríguez Alexander J. , Neeman Teresa , Giles Aaron G. , Mastronardi Claudio A. , Paz Filho Gilberto
Published: November 2014

The clinical manifestations of lipodystrophy syndromes (LS) are hypoleptinemia, hyperglycemia, insulin resistance, dyslipidemia and hepatic steatosis. Leptin replacement therapy (LRT) is effective at improving these pathologies. Currently, there are no data compiling the evidence from the literature, and demonstrating the effect of LRT in LS patients. A systematic review of the MEDLINE and Cochrane Library databases was conducted to identify studies assessing the effect of LRT on metabolic and hepatic endpoints in patients with LS not associated with highly active antiretroviral therapy (HAART) use. Standardized mean differences (SMD) and 95% confidence intervals of pooled results were calculated for overall changes in glucose homeostasis, lipid profile, and hepatic physiology, using an inverse-variance random-effects model. After screening, 12 studies were included for review. Meta-analysis of results from 226 patients showed that LRT decreased fasting glucose [0.75 SMD units (range 0.36‐1.13), p=0.0001], HbA1c [0.49 (0.17‐0.81), p=0.003], triglycerides [1.00 (0.69‐1.31), p<0.00001], total cholesterol [0.62 (0.21‐1.02), p=0.003], liver volume [1.06 (0.51‐1.61), p=0.0002] and AST [0.41 (0.10‐0.73) p=0.01]. In patients with non-HAART LS, LRT improves the outcome of several metabolic and hepatic parameters. Studies were limited by small populations and therefore large prospective trials are needed to validate these findings.
Natalizumab treatment for multiple sclerosis: updates and considerations for safer treatment in JCV positive patients
Authors: Nali Luiz Henrique da Silva , Moraes Lenira , Fink Maria Cristina Domingues , Callegaro Dagoberto , Romano Camila Malta , Oliveira Augusto Cesar Penalva de
Published: November 2014

Natalizumab is currently one of the best options for treatment of patients with Multiple Sclerosis who have failed traditional prior therapies. However, prolonged use, prior immunosuppressive therapy and anti-JCV antibody status have been associated with increased risk of developing progressive multifocal leukoencephalopathy (PML). The evaluation of these conditions has been used to estimate risks of PML in these patients, and distinct (sometimes extreme) approaches are used to avoid the PML onset. At this time, the biggest issue facing the use of Natalizumab is how to get a balance between the risks and the benefits of the treatment. Hence, strategies for monitor JCV-positive patients undergoing Natalizumab treatment are deeply necessary. To illustrate it, we monitored JCV/DNA in blood and urine of a patient receiving Natalizumab for 12 months. We also bring to discussion the effectiveness of the current methods used for risk evaluation, and the real implications of viral reactivation.
Algunas reflexiones sobre la distancia entre "hablar química" y "comprender química"
Authors: Galagovsky Lydia Raquel , Bekerman Diana , Giacomo María Angélica Di , Alí Salvador
Published: November 2014

Una clase de química puede ser considerada como un espacio de comunicación entre el docente experto y los estudiantes novatos, donde los lenguajes utilizados son la interfase explícita y observable del intercambio comunicativo. En el presente trabajo se muestra con dos ejemplos cómo la diversidad de lenguajes químicos en lugar de favorecer la comprensión de los estudiantes, puede actuar como fuente de obstáculos que dificultan la comunicación en el aula. Así mismo, se analizará con otros dos ejemplos cómo el discurso con el que se enseña la disciplina también es potencial generador de errores en los estudiantes, cuando ellos construyen sus modelos mentales idiosincrásicos a partir de un discurso recortado y simplificado, desde las mejores intenciones de realizar buenas transposiciones didácticas. Se plantea que un enfoque de análisis de la situación de aula como un encuentro comunicativo entre experto y novato conduce a una necesaria diferenciación entre "hablar química" y "comprender química".
A estrutura composicional dos textos de estudantes sobre ciclos de materiais: evidências de uso e apropriação da linguagem científica
Authors: Silva Nilma Soares da , Aguiar Junior Orlando Gomes de
Published: November 2014

Neste trabalho, apresentamos uma análise das respostas de estudantes do 8º ano do Ensino Fundamental a uma questão de pós-teste aplicado depois de concluída uma sequência de ensino sobre reações químicas. O foco da análise consiste em identificar os modos de uso e apropriação da linguagem científica pelos estudantes. Utilizamos elementos da gramática funcional de Halliday e Martin para examinarmos a estrutura composicional dos textos. Tal análise foi feita considerando o processo de formação e evolução de conceitos a partir do referencial sociocultural de Vigotsky, destacando-se evidências de apropriação dos conceitos de transformação, elementos e substâncias químicas. Os resultados indicam uma variedade de estilos composicionais, prevalecendo a explicação narrativa mais próxima da linguagem cotidiana. Concluímos que o processo de apropriação é longo e que o pensamento dos estudantes, apesar de ter traços de coerência e objetividade, difere do pensamento conceitual.
A problemática dos organismos geneticamente modificados e a formação científica do cidadão comum: um estudo com manuais escolares de Ciências Naturais do 9º ano adotados em Portugal
Authors: Dourado Luís , Matos Luís
Published: November 2014

Uma das aplicações da biotecnologia são os organismos geneticamente modificados (OGM), os quais têm uma utilização cada vez maior, apresentando vantagens, mas, também, sendo referidos como organismos potencialmente perigosos. Correspondendo a esses factos, os manuais de ciências dedicam algumas das suas páginas à biotecnologia, sendo os OGMs um dos aspetos focados. Nesse sentido e considerando a importância que o manual escolar tem na educação em ciências, procedemos a um estudo que envolveu a análise dos manuais escolares de ciências naturais do 9º ano adotados em Portugal, na parte respeitante aos OGMs. Neste estudo verificou-se que os manuais nem sempre apresentam a informação correta e necessária, de forma adequada, e que nem sempre lhe dão o devido destaque. Dado que a nossa investigação revela a existência de falhas ao nível dos manuais, as conclusões obtidas podem contribuir para uma melhoria dos mesmos e, consequentemente, da qualidade da educação em ciências.
Coherencia curricular y oportunidades para aprender Ciencias
Authors: Zúñiga Marcela Ruiz , Arévalo Alejandra Meneses , Maggio Maximiliano Montenegro
Published: November 2014

Se determinó la coherencia curricular entre oportunidades de aprendizaje y habilidades científicas ofrecidas por un texto escolar chileno y por las actividades de aula en 5º grado asociadas al contenido "Fuerza". Se realizó un análisis discursivo de la unidad didáctica del texto y de las actividades con el fin de construir matrices de contenido para tópicos y habilidades; la medición de coherencia curricular se realizó a través del índice de Porter para la coherencia. Los resultados muestran que el texto escolar promueve más observación (24.2%) y menos ordenamiento de la información (0.95%). En las clases, predominó repetición de contenidos de manera oral y escrita (66.8%) y menos análisis de hipótesis (1.6%). El índice de Porter entre el texto y el aula fue 0.360, entre el texto y el marco curricular fue 0.267. Se concluye que el texto y las clases ofrecen leves oportunidades para el desarrollo de las habilidades científicas.
Mediadores na coconstrução do conhecimento de ciências em atividades de modelagem
Authors: Paganini Paula , Justi Rosária , Mozzer Nilmara Braga
Published: November 2014

Neste trabalho, analisamos como diferentes mediadores podem favorecer a construção de conhecimento pelos estudantes, por meio do processo de coconstrução, durante a realização de atividades de modelagem. Mediadores são entendidos aqui como qualquer entidade que possa auxiliar na construção do conhecimento, fomentando ou facilitando o processo de ensino-aprendizagem. Os dados foram coletados durante a aplicação de atividades de modelagem para o ensino de solubilidade a alunos de 15-16 anos. Para a análise, destacamos os mediadores mais relevantes (ações do professor e dos alunos, modelos, argumentos e gestos) em termos de influência na construção do conhecimento dos estudantes nesse contexto. A análise do papel de cada um deles pode dar suporte às relevantes discussões em contextos de formação de professores.
Adição de lisina digestível em rações experimentais para juvenis de tilápia-do-nilo
Authors: Rampe M.C.C. , Pacheco M.L. , Vargas Júnior J.G. , Giannotti J.D.G. , Demuner L.F. , Marin J.F.V.
Published: November 2014

Objetivou-se por meio deste estudo determinar a necessidade nutricional de lisina digestível em rações para juvenis de tilápia-do-nilo (Oreochromis niloticus). Setecentos e vinte peixes masculinizados (7,30±0,11g) foram alimentados durante 30 dias com oito rações (26,81% de proteína digestível e 3090kcal/kg de energia digestível da ração) contendo teores crescentes de lisina digestível (1,24; 1,36; 1,48; 1,60; 1,72; 1,84; 1,96 e 2,08%). As tilápias foram distribuídas em delineamento inteiramente ao acaso, com oito tratamentos, seis repetições e 15 peixes por unidade experimental. Foram avaliadas variáveis de desempenho (ganho de peso, taxa de crescimento específico, taxa de sobrevivência, consumo de ração, consumo de lisina digestível, conversão alimentar aparente, eficiência proteica para ganho, eficiência de lisina para ganho e eficiência de retenção de nitrogênio) e de composição corporal (teores de umidade, gordura, proteína, matéria mineral corporal e as taxas de deposição diária de proteína e gordura corporais). A elevação do teor de lisina digestível na ração não influenciou (P>0,05) o consumo de ração, a taxa de sobrevivência e os teores de umidade e de matéria mineral corporal, mas melhorou de forma quadrática (P<0,05) os demais parâmetros avaliados, com exceção do consumo de lisina e da eficiência de lisina para ganho, que aumentou e reduziu, respectivamente, de forma linear (P<0,05). Recomenda-se que rações para juvenis de tilápia-do-nilo devam conter 1,84% de lisina digestível para máximo ganho de peso.
Nutritional value of high moisture corn silage in the diet of Holstein cows
Authors: Persichetti Júnior P. , Almeida Júnior G.A. , Costa C. , Meirelles P.R.L. , Silveira J.P.F. , Panichi A. , Silva M.G.B. , Factori M. A. , Cavasano F.A. , Mendonça S.A.
Published: November 2014

Five Holstein cows were distributed in a 5x5 latin square design to assess the effect of replacement levels of dry ground corn grain (DGCG) by high moisture corn silage (HMCS) on intake, total nutrient digestibility and plasma glucose, according to the following treatments: 1) 100% DGCG; 2) 75% DGCG and 25% HMCS; 3) 50% DGCG and 50% HMCS; 4) 25% DGCG and 75% HMCS; 5) 100% HMCS. The experiment lasted 70 days, divided into five phases of 14 days each. The digestibility was obtained using chromic oxide (Cr2O3) as the indicator. Fecal samples were collected twice daily and blood samples were collected on the last day of each period before the first meal (0h) and 2h, 4h, 6h and 12h after the meal. There was no effect (P>0.05) on the intake of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and starch. The total apparent digestibility of DM, crude protein (CP), NDF and ADF were not affected (P>0.05) by the treatments, as well as the plasma glucose concentration. However, there was a decreased linear effect (P<0.05) for the protein intake and increased linear effect (P<0.05) for starch digestibility, as the level of HMCS was increased in the diets.
Relação proteína:carboidrato no desempenho e metabolismo de juvenis de pacamã (Lophiosilurus alexandri)
Authors: Figueiredo R.A.C.R. , Souza R.C. , Bezerra K.S. , Campeche D.F.B. , Campos R.M.L. , Souza A.M. , Melo J.F.B.
Published: November 2014

Objetivou-se neste estudo verificar o melhor nível de inclusão entre proteína e carboidrato no desempenho e algumas respostas metabólicas em juvenis de pacamã (Lophiosilurus alexandri). Testaram-se quatro dietas com as relações proteína/carboidrato (PB:CHO) 1,24; 0,84; 0,51 e 0,33 durante 60 dias. Foram utilizados 240 juvenis de pacamã pesando inicialmente 1,90g, alimentados duas vezes ao dia (8% da biomassa). Avaliou-se o ganho de peso total, taxa de crescimento específico, consumo de ração aparente, conversão alimentar aparente, rendimento de carcaça e gordura visceral. Glicemia, aminoácidos totais livres no plasma e glicogênio hepático também foram avaliados. A relação PB:CHO influenciou (P<0,05) os parâmetros de desempenho e metabolismo, exceto o glicogênio hepático. Maiores concentrações de glicose e aminoácidos totais livres no plasma foram observadas nos peixes que se alimentaram com a dieta contendo a maior relação PB:CHO (1,24). Além disso, observaram-se melhores médias de ganho de peso, taxa de crescimento específico e conversão alimentar aparente. Maiores percentuais de gordura visceral e menor rendimento de carcaça foram observados nos animais submetidos à dieta composta pela menor relação PB:CHO (0,33). Pode-se concluir que a dieta com a relação PB:CHO de 1,24 promoveu melhor desempenho e respostas metabólicas em juvenis de pacamã.
Heating produced by therapeutic ultrasound in the presence of a metal plate in the femur of canine cadavers
Authors: Andrades A.O. , Mazzanti A. , Beckmann D.V. , Aiello G. , Chaves R.O. , Santos R.P.
Published: November 2014

The present study aimed to assess the heat generated by a therapeutic ultrasound (TUS) in a metal bone plate and adjacent structures after fixation to the femur of canine cadavers. Ten pairs of hind limbs were used, and they were equally distributed between groups that were subjected to 1- and 3-MHz frequencies, with each frequency testing 1- and 2-W/cm² intensities. The right hind limb was defined as the control group (absence of the metal plate), and the left hind limb was the test group (presence of the metal plate). Therefore, the control groups (CG) were denominated CGI, using TUS with 1-MHz frequency and 1-W/cm² intensity; CGII, using 1-MHz frequency and 2-W/cm² intensity; CGIII, using 3-MHz frequency and 1-W/cm² intensity; and CGIV, using 3-MHz frequency and 2-W/cm² intensity. For each control group, its respective test group (TG) was denominated TGI, TGII, TGIII and TGIV. The TUS was applied to the lateral aspect of the thigh using the continuous mode and a 3.5-cm² transducer in a 6.25-cm² area for 2 minutes. Sensors were coupled to digital thermometers that measured the temperature in different sites before (t0) and after (t1) of the TUS application. The temperatures in t1were higher in all tested groups. The intramuscular temperature was significantly higher (P<0.05) in the groups used to test the 3-MHz frequency in the presence of the metal plate. The therapeutic ultrasound in the continuous mode using frequencies of 1 and 3 MHz and intensities of 1 and 2 W/cm2 for 2 minutes caused heating of the metal plate and adjacent structures after fixation to the femur of canine cadavers.
O uso do peritônio de paca conservado em solução supersaturada de açúcar a 300% ou glicerina a 98% implantados na parede abdominal de ratos
Authors: Leal L.M. , Ferreira A.R.S. , Reis A.C.G. , Martins L.L. , Garcia Filho S.P. , Machado R.F.
Published: November 2014

Na busca de material biológico alternativo para a realização de implantes, objetivou-se com o presente estudo avaliar comparativamente a implantação do peritônio de paca, uma nova opção de biomaterial, conservado em solução supersaturada de açúcar a 300% e conservado em glicerina a 98% na parede abdominal de ratos Wistar. Foram utilizados 60 ratos, machos, da linhagem Wistar, pesando entre 150 e 200 gramas, organizados nos seguintes grupos experimentais: grupo controle (GI), grupo peritônio conservado em solução supersaturada de açúcar a 300% (GII) e grupo peritônio conservado em glicerina a 98% (GIII), cada um com 20 animais. Os grupos GII e GIII receberam o enxerto de peritônio da paca conservado em solução de açúcar 300% e glicerina 98%, respectivamente, e o grupo GI não recebeu a membrana. Cinco ratos de cada grupo foram submetidos à eutanásia em quatro momentos distintos: sete, 15, 30 e 60 dias de pós-operatório para avaliações macroscópicas e microscópicas da interface implante-tecido nativo. Apesar de reações adversas observadas em 57,5% dos animais do grupo GII e GIII, em 95% dos animais desses grupos houve boa cicatrização da membrana. Na análise histológica, verificou-se a presença de grande infiltrado inflamatório nos períodos iniciais (sete e 15 dias) e grande presença de tecido conjuntivo nos momentos finais (30 e 60 dias). Concluiu-se que o peritônio da paca como membrana biológica conservado nos meios estudados pode ser utilizado com segurança na parede abdominal de ratos; ainda, que sua conservação em solução supersaturada de açúcar a 300% permitiu melhor maleabilidade no ato cirúrgico.
Quantificação de citocinas no soro e homogenato da pata na intoxicação experimental com veneno de Bothropoides jararaca em ratos Wistar tratados com soroterapia e Mikania glomerata
Authors: Motta Y.P. , Sakate M. , Nogueira R.M.B. , Peraçoli M.T.S. , Sangiorgio F. , Floriano R.S. , Takahagi E.N.
Published: November 2014

O presente estudo teve como objetivo quantificar os níveis de citocinas pró-inflamatórias, entre as quais TNF-α, interleucina-1β (IL-1β), IL-6, e anti-inflamatórias, como IL-10, interferon-γ (INF-γ), bem como comparar o efeito do tratamento convencional com o efeito do tratamento complementado pelo extrato da planta Mikania glomerata, na intoxicação experimental por Bothropoides jararaca. Foram usados ratos Wistar,divididos em três grupos: C - controle, VB - veneno botrópico + soro antiofídico e VBM - veneno botrópico + soro antiofídico + Mikania glomerata. As citocinas foram quantificadas, no soro e no homogenato desses animais, pelo teste ELISA, em três momentos (M1 - 30 minutos, M2 - seis horas e M3 - 24 horas após a inoculação do veneno). Os resultados obtidos evidenciaram que a intoxicação por veneno botrópico estimula principalmente a produção de IL-6 no soro e TNF-α, IL-1β, IL-6 no homogenato da pata de animais experimentalmente intoxicados. O tratamento complementar, com o extrato da planta Mikania glomerata, teve influência principalmente na produção de IL-6, IL-10 e IFN-γ no soro e IL-6, IL-1β e IFN-γ no homogenato. Porém, são necessários novos estudos com o extrato de Mikania glomerata para que se possa entender a ação dessa planta sobre a intoxicação botrópica, bem como verificar qual a melhor via para administrá-lo.
Morfometria corpórea, características do sêmen, proteínas seminais e testosterona em cervos Cervus unicolor, em cativeiro
Authors: Chacur M.G.M. , Martins E.A.F. , Silva A.A. , Guaberto L.M. , Gabriel Filho L.R.A. , Sanches O.C. , Oba E.
Published: November 2014

Objetivou-se estudar a morfometria corpórea, as características do sêmen, o perfil proteico do plasma seminal em SDS-PAGE e a concentração sérica de testosterona em cervos-sambar (Cervus unicolor), criados em cativeiro, na estação reprodutiva da primavera. Quatro machos com idades entre 12 e 36 meses foram avaliados em quatro momentos, com intervalos de sete dias, com peso corpóreo (60,5 a 89,0kg), índice de massa corporal (93,07kg/m2 a 126,56kg/m2), volume do ejaculado (0,50±0,35mL a 0,75±0,28mL), motilidade espermática (87,75±4,78% a 90,00±7,07%), defeitos totais (17,25±5,81% a 47,72±17,55%), testosterona sérica (6,43±4,33ng/dL a 166,00±64,48ng/dL) e proteínas do plasma seminal com bandas entre 7,6 e 142kDa. As características dos ejaculados não diferiram (P>0,05) entre as três primeiras colheitas. Houve diferença (P<0,05) para os defeitos espermáticos com elevação na quarta colheita. No plasma seminal de cada cervo, foram identificadas de 16 a 27 bandas de proteínas entre 7,6 e 142kDa. Conclui-se que a qualidade espermática foi satisfatória na primavera. O estresse das contenções sucessivas causou queda da qualidade espermática. A idade influi na concentração sérica de testosterona, a qual foi maior nos cervos aos 36 meses.
Partial lateral corpectomy associated with pediculectomy to treat extradural chondroma in a dog: technique description
Authors: Marinho P.V.T. , Zani C.C. , Jark P.C. , Minto B.W. , Costa M.T.
Published: November 2014

This study aimed to describe in detail the surgical technique of partial lateral corpectomy (PLC) associated with pediculectomy to treat an in vitroextradural chondroma. A 12-year old female Cocker Spaniel was seen in the hospital with proprioceptive ataxia of hind limbs associated with extradural compression between the 1st and 2nd lumbar vertebrae. The owner opted for euthanasia since the patient's condition changed due to simultaneous illnesses that culminated in a poor prognosis. The patient's body was formally ceded to perform experimental spinal decompression. The technique was effective to completely remove the epidural mass with minimal manipulation of the spinal cord.