Image Guided Cancer Therapy: Developing a Process for Quantitative Organ Imaging

In developing new nanoparticle-based image guided drug delivery systems it is important to measure the drug’s bio-distribution, the percent of injected drug that reaches target and non-target tissues over time and the drug’s plasma clearance. The main technique used to measure drug concentration in tissue or plasma requires extracting the drug (or fluorescent dye in the case of an imaging agent) from the tissue, but can be avoided by directly imaging the drug in the tissue or blood. However, the fluorescence signal obtained directly from the organ is reduced by scatter and absorption. Instead of imaging whole organs, the tissue is sectioned. A calibration curve is required to convert fluorescence intensity to drug concentration. This calibration curve will be able to quantitatively predict the concentration of drug based on fluorescence levels from nanoparticles loaded with IR-820 dye and drug. The calibration curve was created by synthesizing phantoms using sodium chloride, TRIS buffer, sodium azide, porcine gelatin, hemoglobin and IR-820. Different concentrations of IR-820 (4?M, 2?M, 1?M, 0.5?M, 0.25?M, and a control) were added to the phantoms. Precise and accurate slices of the molds at thicknesses of 5?m, 10?m, 15?m, and 20?m were achieved using a cryostat. Their fluorescence was imaged and measured using the Odyssey CLX. It is assumed that the IR-820 is uniformly distributed in all samples. The results of the experiment demonstrated that there is a linear relationship between the thickness of the phantoms and the fluorescence signal it emits. The relationship between the concentrations and the signal isn’t as a direct and doesn’t demonstrate such a linear trend. Further analysis is being performed to see the effects of the Porcine hemoglobin in the samples as well as the mixing of the IR-820 with the gelatin for the stock solutions

Multifocal outbreak of equine influenza in vaccinated horses in Argentina in 2018: Epidemiological aspects and molecular characterisation of the involved virus strains

Background: Equine influenza is an important cause of respiratory disease of horses worldwide. The equine influenza virus (EIV) undergoes antigenic drift through the accumulation of amino acid substitutions in the viral proteins, which may lead to vaccine breakdown. Objectives: To describe the epidemiological findings and the molecular characteristics of the EIV detected during the multifocal outbreak that occurred in Argentina between March and July 2018 and evidence a vaccine breakdown. Study design: Observational, descriptive study. Methods: Virus was detected in nasopharyngeal swabs using real-time reverse transcriptase PCR (RT-PCR). Nucleotide and deduced amino acid sequences of the haemagglutinin (HA) and neuraminidase (NA) genes were obtained from EIV positive nasopharyngeal swabs, and phylogenetic analysis was undertaken. Amino acid sequences were compared against the current World Organisation for Animal Health (OIE)-recommended Florida clade 1 vaccine strain and strain components of vaccines used in Argentina. Serum samples were tested using haemagglutination inhibition test. Results: Equine influenza virus infection was confirmed using real-time RT-PCR and serological testing. The phylogenetic analysis of the HA and NA genes revealed that all the EIV identified during the outbreak belong to the H3N8 subtype, Florida clade 1. Multiple amino acid changes, some of them at antigenic sites, were observed in the circulating virus when compared with the strains included in the most commonly used vaccine in Argentina. Seventy-six percent of the affected horses had been vaccinated with this vaccine, suggesting the occurrence of vaccine breakdown. Main limitations: The study does not include antigenic characterisation and full genome sequencing of Argentinian strains, that could provide additional information. Conclusions: The occurrence of this multifocal equine influenza outbreak in regularly vaccinated horses is a field evidence of vaccine breakdown, reinforcing the necessity of keeping vaccine strains updated according to OIE recommendations. It also underlines the importance of the implementation of appropriate quarantine measures and restriction of horse movement in the face of disease.Fil: Olguin Perglione, Cecilia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Vissani, María Aldana. Universidad del Salvador; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alamos, Florencia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Barrandeguy, M.. Universidad del Salvador; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentin

Local conditions vs regional context: variation in composition of bird communities along the Middle Paraná River, an extensive river-floodplain system of South America

We studied spatial changes in species composition (i.e., beta diversity) of local assemblages of birds along ∼450 km of the Middle Paraná River, an extensive fluvial system of South America. Point counts were used to survey birds at 60 plots located in shrub swamps and marshes of the floodplain within four sites (15 plots per site). Two sites were surrounded by each of the two upland ecoregions. Beta diversity of bird assemblages was high and was more important than alpha diversity in shaping regional diversity (i.e., gamma diversity) of the fluvial system. Compositional changes were related to species turnover among plots, while nestedness dissimilarity was not important for shaping diversity patterns. Variation-partitioning analysis showed that local conditions (i.e., landscape composition within a radius of 200 m from the center of each plot) accounted for more spatial variation in assemblage composition than did location along the fluvial system. Adjacent upland ecoregions did not account for spatial changes in bird composition within the fluvial system. In conclusion, environmental heterogeneity created by flood pulses is an important factor for sustaining regional diversity of birds within the fluvial system through effects on beta diversity

El proyecto, un universo a construir

El Curso de Nivelación de la Facultad de Arquitectura, Urbanismo y Diseño promueve la exploración, la recuperación de experiencias individuales y grupales, el intercambio y la discusión a través del trabajo en taller, y la elaboración de conceptos

Modelling Tropical Deforestation: A Comparison of Approaches

International audienceTropical deforestation, as an important factor in global change, is a topic that recently has received considerable attention. GIS-based spatially explicit models that intend to predict the location of land use/cover change (LUCC) can help scientists and policy makers to understand, anticipate and possibly prevent the adverse effects of land-use change. There are many approaches and softwares to model LUCC such as CLUE-S, DINAMICA GEOMOD and IDRISI. This study intends to compare these four modelling approaches. First, a review of methods and tools employed by each software to carry out the simulation was done. Then, the four packages were applied to a "virtual" case which involves a map of deforestation, which comprises two types of deforestation (forest to shifting agriculture and forest to pasture lands), along with several explanatory variables (drivers). Deforestation was modelled using the four approaches and the output maps were compared

Stress detection using wearable physiological and sociometric sensors

Stress remains a significant social problem for individuals in modern societies. This paper presents a machine learning approach for the automatic detection of stress of people in a social situation by combining two sensor systems that capture physiological and social responses. We compare the performance using different classifiers including support vector machine, AdaBoost, and k-nearest neighbour. Our experimental results show that by combining the measurements from both sensor systems, we could accurately discriminate between stressful and neutral situations during a controlled Trier social stress test (TSST). Moreover, this paper assesses the discriminative ability of each sensor modality individually and considers their suitability for real time stress detection. Finally, we present an study of the most discriminative features for stress detection

Local structure adaptability through multi cations for oxygen redox accommodation in Li-Rich layered oxides

Stable lattice oxygen redox (l-OR) is the key enabler for achieving attainable high energy density in Li-rich layered oxide cathode materials for Li-ion batteries. However, the unique local structure response to oxygen redox in these materials, resulting in energy inefficiency and hysteresis, still remains elusive, preventing their potential applications. By combining the state-of-the-art neutron pair distribution function with crystal orbital overlap analysis, we directly observe the distinct local structure adaption originated from the potential O–O chemical bonds. The structure adaptability is optimized based on the nature of multi transition metals in our model compound Li1.2Ni0.13Mn0.54Co0.13O2, which accommodates the oxygen redox and at the same time preserves the global layered structure. These findings not only advance the understanding of l-OR, but also provide new perspectives in the rational design of high-energy-density cathode materials with reversible and stable l-OR

Desarrollo de una herramienta de apoyo a la enseñanza de biología: el caso del Microscopio Virtual de Histología

El microscopio de luz es una herramienta muy importante para enseñar sobre tejidos corporales. Sin embargo, no es siempre que este instrumento se encuentra disponible para uso en cursos de grado, posgrado y, en particular, en la educación básica. Con esto, la creación de un Atlas Virtual de Histología (el Microscopio Virtual de Histología), combinado con la amplia posibilidad de acceso de la Internet, permitirá ofrecer una fuente de información alternativa en la construcción del conocimiento científico. De manera diferente a los atlas disponibles en la literatura, que generalmente presentan la imagen de un tejido en un único aumento, el microscopio virtual propuesto en este estudio presenta la imagen en incrementos progresivos, intentando simular una visualización en un microscopio real. En este trabajo se presenta el estado actual de desarrollo del microscopio virtual y los próximos pasos.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Desarrollo de una herramienta de apoyo a la enseñanza de biología: el caso del Microscopio Virtual de Histología

El microscopio de luz es una herramienta muy importante para enseñar sobre tejidos corporales. Sin embargo, no es siempre que este instrumento se encuentra disponible para uso en cursos de grado, posgrado y, en particular, en la educación básica. Con esto, la creación de un Atlas Virtual de Histología (el Microscopio Virtual de Histología), combinado con la amplia posibilidad de acceso de la Internet, permitirá ofrecer una fuente de información alternativa en la construcción del conocimiento científico. De manera diferente a los atlas disponibles en la literatura, que generalmente presentan la imagen de un tejido en un único aumento, el microscopio virtual propuesto en este estudio presenta la imagen en incrementos progresivos, intentando simular una visualización en un microscopio real. En este trabajo se presenta el estado actual de desarrollo del microscopio virtual y los próximos pasos.Sociedad Argentina de Informática e Investigación Operativa (SADIO