A Functional MRI and Magneto/Electro Source Imaging Procedure for Cognitive and Pre-surgical Evaluation

AbstractAnalysis of normal/pathological brain activity using neuroimaging methods is necessary to avoid operation risks, and the outcome serves as prior information for surgical neuronavigation. We present an fMRI/MEG/EEG-based methodology for tasks demanding mainly sensorimotor and visual/cognitive responses. This consists of carefully selected/designed stimulation paradigms and statistical parametric mapping methods that demonstrate the practicability of these techniques for clinical applications. The results replicate known findings in the brain-imaging field, with the improvement that our analyses are restricted to grey matter tissue. The latter enhance computations, which is advantageous for the massive data analyses that are typical of clinical and radiological functional brain “checkup” services

The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network

The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0% – 0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further development of biomimetic tools for measuring RBC deformability (e.g. the AMVN) could enable a more functionally relevant testing of RBC mechanical properties

The Need of a Neonatal Preparation for Chagas Disease

Fil: Sosa-Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: Belizan, Jose M. Department of Mother and Child Health Research, Institute for Clinical Effectiveness and Health Policy (IECS), Buenos Aires; Argentina.Fil: Althabe, Fernando. Department of Mother and Child Health Research, Institute for Clinical Effectiveness and Health Policy (IECS), Buenos Aires; Argentina.Fil: Rubinstein, Aldofo. Institute for Clinical Effectiveness and Health Policy, Buenos Aires; Argentina.We have read about the efforts and initiatives related to the design of drugs for parasitic diseases in McKerrow's article [1] with interest and expectation. One of the pressing needs in this area is for a neonatal preparation for Chagas disease. Satisfactory achievements have been made in Argentina in relation to the transmission of the disease by vectors and through blood transfusion [2,3]. Vertical transmission is now the great challenge in eradicating Chagas disease. Around 800–1,300 neonates infected with Trypanosmoma cruzi are born every year in our country [4]. Almost 99% of all births occur in hospital, thus allowing the detection of infants born with parasites immediately after birth. The initiation of treatment of these neonates before they and their mothers leave the hospital is a good strategy to obtain high treatment coverage. The later attendance of mothers with their children to health-care facilities is quite unpredictable and irregular. Also, it is difficult to link information about maternal and neonatal parasitic status obtained at birth with later attendance at other health-care facilities

Sucesiones figurales, una secuencia didáctica utilizando las variables como números generales

Both numerical and figural sequences are used on secondary level students in order to visualize variables as general numbers. During there apprenticeship participants could experience different kinds of difficulties and are unable to identify the pattern that governs the succession, not coordinate the spatial structure to the number, and going from a numerical representation to an algebraic. We believe that sometimes the time devoted to this activity is not enough and exercises proposed by some teachers and some official textbooks are mostly successions of linear and numeric. Only some exercises raised are with figural sequences of type quadratic. The purpose of this research is to implement a teaching sequence in which figural succession of linear and quadratic involved in which students are able to visualize the behavior or pattern of figure and thereby have greater chances of reaching an algebraic generalization. As a model in this research Theory of Didactic Situations Brousseau that is a theory of teaching, in which mathematical objects that will teach could have an origin that is generated or built by professor were use with some intentionality. As it was proposed methodology Didactic Engineering Artigue, which consists of four phases: preliminary analysis, design and a priori analysis of teaching situations, experimentation and subsequent analysis and validation. One of the main results found is that students of junior year (aged 15 to 16 years), were able to recognize the pattern and reach the generalization of a figural succession of linear and quadratic due to the sequences used. Figural first solving a linear succession, generating a first approach, then work with quadratic succession.Las sucesiones tanto numéricas como figurales son empleadas para que los estudiantes de nivel de secundaria logren usar la variable como número general. Durante su aprendizaje podrían experimentar diferentes tipos de dificultades como son: no identificar el patrón que rige a la sucesión, no coordinar la estructura espacial a la numérica, pasar de una representación numérica a una algebraica, entre otras. Además de esto, consideramos que en algunas ocasiones el tiempo que se dedica a esta actividad no es suficiente y desafortunadamente los ejercicios propuestos por algunos profesores y por ciertos libros de texto oficiales, son en su mayoría sucesiones del tipo lineal y numérico, sólo algunos ejercicios planteados son con sucesiones figurales del tipo cuadrático. Es por eso que el propósito de esta investigación es implementar una secuencia didáctica en la que se involucren sucesiones figurales del tipo lineal y cuadrático, en la que los estudiantes consigan por sí solos visualizar el comportamiento o el patrón de la figura y con esto tengan mayores posibilidades de llegar a una generalización algebraica. Como modelo en esta investigación se utilizó La Teoría de Situaciones Didácticas de Brousseau se trata de una teoría de la enseñanza, en la que los objetos matemáticos que se van a enseñar podrían tener un origen que sea generado o construido por el profesor, con una cierta intencionalidad. Como metodología se propuso a La Ingeniería Didáctica de Artigue, que se compone de cuatro fases: análisis preliminares, concepción y análisis a priori de las situaciones didácticas, experimentación y de análisis a posteriori y validación. Uno de los principales resultados que se encontraron es que, estudiantes de tercer año de secundaria (edades entre 15 y 16 años), lograron reconocer el patrón y llegar a la generalización de una sucesión figural del tipo lineal y cuadrático, debido a las secuencias utilizadas. Primero resolviendo una sucesión figural del tipo lineal, lo que generó un primer acercamiento, para posteriormente trabajar con la sucesión del tipo cuadrático

The Bariloche Neutron Physics Group Current Activities

Our group has evolved around a small accelerator-based neutron source (ABNS), the 25 million electron Volt (MeV) linear electron accelerator at the Bariloche Atomic Centre. It is dedicated to applications of neutronic methods to tackle problems of basic sciences and to technological applications. Among these, the determination of total cross section of a material as a function of neutron energy by means of transmission experiments for thermal and sub-thermal neutrons is very sensitive to the geometric arrangement and movement of the atoms, over distances ranging from the 'first-neighbour scale' up to the microstructural level or 'grain scale'. This also allowed to test theoretical models of calculated cross sections and scattering kernels. Interest has moved from pulsed neutron diffraction towards deep inelastic neutron scattering (DINS), a powerful tool for the determination of atomic momentum distribution in condensed matter and for non-destructive mass spectroscopy. In recent years non-intrusive techniques aimed at the scanning of large cargo containers have started to be developed with this ABNS, testing the capacity and limitations to detect special nuclear material and dangerous substances in thick cargo arrangements. More recently, the use of the ever-present “bremsstrahlung” radiation has been recognized as a useful complement to instrumental neutron activation, as it permits to detect other nuclear species through high-energy photon activation. The facility is also used for graduate and undergraduate students experimental work within the frame of Instituto Balseiro Physics and Nuclear Engineering courses of study, and also MSc and PhD theses work.Fil: Mayer, Roberto Edmundo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: D'Amico, N. M. B.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Granada, Jose Rolando. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dawidowski, Javier. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santisteban, Javier Roberto. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blostein, Juan Jeronimo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tartaglione, Aureliano. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez Palomino, Luis Alberto. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marquez Damian, Jose Ignacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sepúlveda Sosa, C.. Comision Chilena de Energia Nuclear; Chil

Acute Effects of Squat Position and Whole-body Vibration Frequencies on Muscular Function and Jump Performance

PURPOSE: To determine the acute effects of different whole-body vibration (WBV) frequencies and squat depths on lower extremity isometric and isokinetic muscle function and vertical jump performance. METHODS: Thirteen healthy male (age = 23.8 ± 5.3 years) and fifteen healthy female subjects (age = 22.45 ± 3.04 years) performed six randomized sessions of vibration protocols (VPs) in different squat positions with 90° (low-squat) and 140° (high-squat) knee flexion angle at 30 Hz (30Hz90°; 30Hz140°), 40 Hz (40Hz90°; 40Hz140°) & 50 Hz (50Hz90°; 50Hz140°). Each subject performed 5 sets x 1-min of static squats with 30-sec rest between each set. Then they rested for 5-min and repeated 5 more sets. Once completed, vertical jump performance was measured. Furthermore, subjects were tested for maximum 5-sec right knee extensor isometric contractions at 60° of knee flexion, and isokinetic concentric knee extension and flexion at 180°/sec, utilizing standard Biodex protocol. All VPs were performed on the same commercial side to side alternating vibration platform and foot placement for all squats was recorded to ensure consistency. RESULTS: Two-way repeated measures ANOVA indicated a significant condition main effect in average jump height (pCONCLUSION: The findings are suggestive of greater muscular strength and explosive power production following a high-squat WBV warm-up compared to low-squat WBV warm-up. This can be attributed to augmented muscle fatigue and/or increased muscle length due to the plasticity of skeletal muscle while performing low-squat WBV warm-up, resulting in impaired ability to produce muscular force

First results from the Very Small Array -- I. Observational methods

The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from other CMB interferometers with the result that different systematic errors are expected. We have tested the operation of the VSA with a variety of blank-field and calibrator observations and cross-checked its calibration scale against independent measurements. We find that systematic effects can be suppressed below the thermal noise level in long observations; the overall calibration accuracy of the flux density scale is 3.5 percent and is limited by the external absolute calibration scale.Comment: 9 pages, 10 figures, MNRAS in press (Minor revisions

A Comprehensive Evaluation of Sdox, a Promising H2S-Releasing Doxorubicin for the Treatment of Chemoresistant Tumors

Sdox is a hydrogen sulfide (H2S)-releasing doxorubicin effective in P-glycoprotein-overexpressing/doxorubicin-resistant tumor models and not cytotoxic, as the parental drug, in H9c2 cardiomyocytes. The aim of this study was the assessment of Sdox drug-like features and its absorption, distribution, metabolism, and excretion (ADME)/toxicity properties, by a multi- and transdisciplinary in silico, in vitro, and in vivo approach. Doxorubicin was used as the reference compound. The in silico profiling suggested that Sdox possesses higher lipophilicity and lower solubility compared to doxorubicin, and the off-targets prediction revealed relevant differences between Dox and Sdox towards several cancer targets, suggesting different toxicological profiles. In vitro data showed that Sdox is a substrate with lower affinity for P-glycoprotein, less hepatotoxic, and causes less oxidative damage than doxorubicin. Both anthracyclines inhibited CYP3A4, but not hERG currents. Unlike doxorubicin, the percentage of zebrafish live embryos at 72 hpf was not affected by Sdox treatment. In conclusion, these findings demonstrate that Sdox displays a more favorable drug-like ADME/toxicity profile than doxorubicin, different selectivity towards cancer targets, along with a greater preclinical efficacy in resistant tumors. Therefore, Sdox represents a prototype of innovative anthracyclines, worthy of further investigations in clinical settings

ConBr lectin modulates MAPKs and Akt pathways and triggers autophagic glioma cell death by a mechanism dependent upon caspase-8 activation

Glioblastoma multiforme is the most aggressive type of glioma, with limited treatment and poor prognosis. Despite some advances over the last decade, validation of novel and selective antiglioma agents remains a challenge in clinical pharmacology. Prior studies have shown that leguminous lectins may exert various biological effects, including antitumor properties. Accordingly, this study aimed to evaluate the mechanisms underlying the antiglioma activity of ConBr, a lectin extracted from the Canavalia brasiliensis seeds. ConBr at lower concentrations inhibited C6 glioma cell migration while higher levels promoted cell death dependent upon carbohydrate recognition domain (CRD) structure. ConBr increased p38MAPK and JNK and decreased ERK1/2 and Akt phosphorylation. Moreover, ConBr inhibited mTORC1 phosphorylation associated with accumulation of autophagic markers, such as acidic vacuoles and LC3 cleavage. Inhibition of early steps of autophagy with 3-methyl-adenine (3-MA) partially protected whereas the later autophagy inhibitor Chloroquine (CQ) had no protective effect upon ConBr cytotoxicity. ConBr also augmented caspase-3 activation without affecting mitochondrial function. Noteworthy, the caspase-8 inhibitor IETF-fmk attenuated ConBr induced autophagy and C6 glioma cell death. Finally, ConBr did not show cytotoxicity against primary astrocytes, suggesting a selective antiglioma activity. In summary, our results indicate that ConBr requires functional CRD lectin domain to exert antiglioma activity, and its cytotoxicity is associated with MAPKs and Akt pathways modulation and autophagy- and caspase-8- dependent cell death.Fil: Wolin, Ingrid A. V.. Universidade Federal de Santa Catarina; BrasilFil: Heinrich, Isabella A.. Universidade Federal de Santa Catarina; BrasilFil: Nascimento, Ana Paula M.. Universidade Federal de Santa Catarina; BrasilFil: Welter, Priscilla G.. Universidade Federal de Santa Catarina; BrasilFil: Sosa, Liliana del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: de Paul, Ana Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Zanotto Filho, Alfeu. Universidade Federal de Santa Catarina; BrasilFil: Nedel, Cláudia Beatriz. Universidade Federal de Santa Catarina; BrasilFil: Lima, Lara Dias. Universidade Estadual do Ceará; BrasilFil: Osterne, Vinicius Jose Silva. Universidade Estadual do Ceará; BrasilFil: Pinto Junior, Vanir Reis. Universidade Estadual do Ceará; BrasilFil: Nascimento, Kyria S.. Universidade Estadual do Ceará; BrasilFil: Cavada, Benildo S.. Universidade Estadual do Ceará; BrasilFil: Leal, Rodrigo B.. Universidade Federal de Santa Catarina; Brasi