Cryptococcosis in Atlántico, Colombia: an approximation of the prevalence of this mycosis and the distribution of the etiological agent in the environment

ABSTRACTINTRODUCTION:Cryptococcosis is an invasive disease acquired by inhalation of infectious propagules from the environment. Currently, compulsory notification of the spread of this disease is not required in Colombia. However, reporting of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome cases to the National Surveillance System has suggested that there is a growing population at risk of contracting cryptococcosis. Few studies have described the occurrence of cryptococcosis in Colombia. Therefore, in this study, we examined the pathology of this disease in Atlántico, Colombia and determined the distributions of Cryptococcus neoformans and Cryptococcus gattii in the environment.METHODS:Clinical samples/isolates were gathered from cases of cryptococcosis previously diagnosed at health institutions in Atlántico, and surveys were completed by clinicians. The environmental study considered 32 sampling points and three tree species, i.e., Quickstick ( Gliricidia sepium ), Almond ( Terminalia catappa ), and Pink trumpet ( Tabebuia rosea ). Environmental and clinical samples/isolates were analyzed for phenotypic and genotypic confirmation.RESULTS:From 1997-2014, 41 cases of cryptococcosis were reported. The mean patient age was 40.5 years (range: 18-63 years); 76% were men, and 78% were HIV positive. Isolation was possible in 38 cases ( C. neoformans , molecular type VNI in 37 cases and C. gattii , molecular type VGI in one case). In 2012-2014, 2,068 environmental samples were analyzed with a positivity of 0.4% ( C. neoformans , molecular type VNI) in Almond and Pink trumpet trees.CONCLUSIONS:Cryptococcus neoformans , molecular type VNI had a higher prevalence than C. gattii and was associated with human exposure and the pathogenesis of cryptococcosis in this geographical region.

Generalized Dasymetric Mapping Algorithm for Accessing Land-Use Change

Contém resumo

Modulation of the secretome of hBMSCs by tailoring the macromolecular gradient in hydrogels to generate tissue-to-tissue interfaces

Tissue-to-tissue interfaces are commonly present in all tissues exhibiting structural, biological and chemical gradients serving a wide range of physiological functions. These interfaces are responsible for mediation of load transfer between two adjacent tissues. They are also important structures in sustaining the cellular communications to retain tissueâ s functional integration and homeostasis. [1] All cells have the capacity to sense and respond to physical and chemical stimulus and when cultured in three-dimensional (3D) environments they tend to perform their function better than in two-dimensional (2D) environments. Spatial and temporal 3D gradient hydrogels better resemble the natural environment of cells in mimicking their extracellular matrix. [2] In this study we hypothesize that differential functional properties can be engineered by modulation of macromolecule gradients in a cell seeded threedimensional hydrogel system. Specifically, differential paracrine secretory profiles can be engineered using human Bone Marrow Stem Cells (hBMSCâ s). Hence, the specific objectives of this study are to: assemble the macromolecular gradient hydrogels to evaluate the suitablity for hBMSCâ s encapsulation by cellular viability and biofunctionality by assessing the paracrine secretion of hBMSCâ s over time. The gradient hydrogels solutions were prepared by blend of macromolecules in one solution such as hyaluronic (HA) acid and collagen (Col) at different ratios. The gradient hydrogels were fabricated into cylindrical silicon moulds with higher ratio solutions assembled at the bottom of the mould and adding the two solutions consecutively on top of each other. The labelling of the macromolecules was performed to confirm the gradient through fluorescence microscopy. Additionally, AFM was conducted to assess the gradient hydrogels stiffness. Gradient hydrogels characterization was performed by HA and Col degradation assay, degree of crosslinking and stability. hBMSCâ s at P3 were encapsulated into each batch solution at 106 cells/ml solution and gradient hydrogels were produced as previously described. The hBMSCâ s were observed under confocal microscopy to assess viability by Live/Dead® staining. Cellular behaviour concerning proliferation and matrix deposition was also performed. Secretory cytokine measurement for pro-inflammatory and angiogenesis factors was carried out using ELISA. At genomic level, qPCR was carried out. The 3D gradient hydrogels platform made of different macromolecules showed to be a suitable environment for hBMSCâ s. The hBMSCâ s gradient hydrogels supported high cell survival and exhibited biofunctionality. Besides, the 3D gradient hydrogels demonstrated differentially secretion of pro-inflammatory and angiogenic factors by the encapsulated hBMSCâ s. References: 1. Mikos, AG. et al., Engineering complex tissues. Tissue Engineering 12,3307, 2006 2. Phillips, JE. et al., Proc Natl Acad Sci USA, 26:12170-5, 2008

Comparing standard and low-cost tools for gradient evaluation along potential cycling paths

Promoting the use of non-motorized modes of transport, such as cycling, is an important contribution to the improvement of mobility, accessibility and equity in cities. Cycling offers a fast and cheap transportation option for short distances, helping to lower pollutant emissions and contributing to a healthier way of life. In order to make the cycling mode more competitive in relation to motorized traffic, it is necessary to evaluate the potential of alternatives from the perspective of the physical effort. One way to do so consists of assessing the suitability of locations for implementing cycling infrastructures. In this work, four tools to determine the gradient along potential cycling paths are compared. Furthermore, an evaluation of the reliability of some low-cost tools to measure this parameter was conducted, by comparison with standard measurements using cartographic plans, on a field case study applied to the city of Braga, Portugal. These tools revealed a good level of accuracy for the planning stage, but proved to be less reliable for use in design.

Analytical and numerical study of the electro-osmotic annular flow of viscoelastic fluids

In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed.

Myopia control with a novel peripheral gradient soft lens and orthokeratology: a 2-year clinical trial

Objective. To evaluate the degree of axial elongation with soft radial refractive gradient (SRRG) contact lenses, orthokeratology (OK), and single vision (SV) spectacle lenses (control) during a period of 1 year before treatment and 2 years after treatment. Methods. This was a prospective, longitudinal, nonrandomized study. The study groups consisted of 30, 29, and 41 children, respectively. The axial length (AL) was measured during 2 years after recruitment and lens fitting. Results. The baseline refractive sphere was correlated significantly (r 2 = 0.542; P < 0.0001) with the amount of myopia progression before baseline. After 2 years, the mean myopia progression values for the SRRG, OK, and SV groups were −0.56 ± 0.51, −0.32 ± 0.53, and −0.98 ± 0.58 diopter, respectively. The results represent reductions in myopic progression of 43% and 67% for the SRRG and OK groups, respectively, compared to the SV group. The AL increased more in the SV group compared to the SRRG and OK groups, with 27% and 38% lower axial elongation, respectively, compared to the SV group at the 2-year visit (P < 0.05). SRRG and OK showed no differences (P = 0.430). Conclusion. The SRRG lens significantly decreased AL elongation compared to the SV control group. The SRRG lens was similarly effective to OK in preventing myopia progression in myopic children and adolescent.

Palm community transitions along a topographic gradient from floodplain to terra firme in the eastern Amazon

Palms show clear niche segregation patterns along topographic gradients in tropical forests, with some species associated to terra firme and others to seasonally flooded areas. The aim of this study was to quantitatively describe the fine-scale spatial variation within a palm community, tracking the changes in species' abundance along environmental gradients associated with a perennial stream the eastern Amazon. The study of palm communities was based on 60 forest plots in which all adult palms were counted. We found a total of 566 palms in a community containing 11 species. Furthermore, we found a significant separation in the palm community between seasonally-flooded and terra firme forests. We found a gradient with various densities of the three most abundant palm species within the first 100 m away from the flooded area. Other species were located exclusively in the terra firme forest. The abundance of the six most common species were distributed in relation to humidity gradients from floodplains to terra firme, with palm distribution from the most flood-tolerant to the least flood-tolerant palm species as follows: Euterpe oleracea, Attalea phalerata and Socratea exorrhiza (species with floodplain affinity), Astrocaryum gynacanthum, Astrocaryum aculeatum, Attalea maripa (species with terra firme affinity)

Regulation of human mesenchymal stem cell osteogenesis by specific surface density of fibronectin: a gradient study

 The success of synthetic bone implants requires good interface between the material and the host tissue. To study the biological relevance of fi bronectin (FN) density on the osteogenic commitment of human bone marrow mesenchymal stem cells (hBMMSCs), human FN was adsorbed in a linear density gradient on the surface of PCL. The evolution of the osteogenic markers alkaline phosphatase and collagen 1 alpha 1 was monitored by immunohistochemistry, and the cytoskeletal organization and the cell-derived FN were assessed. The functional analysis of the gradient revealed that the lower FN-density elicited stronger osteogenic expression and higher cytoskeleton spreading, hallmarks of the stem cell commitment to the osteoblastic lineage. The identifi cation of the optimal FN density regime for the osteogenic commitment of hBM-MSCs presents a simple and versatile strategy to signifi cantly enhance the surface properties of polycaprolactone as a paradigm for other synthetic polymers intended for bone-related applications.

Osteogenic differentiation of human mesenchymal stem cells in the absence of osteogenic supplements: a surface-roughness gradient study

The use of biomaterials to direct osteogenic differentiation of human mesenchymal stem cells (hMSCs) in the absence of osteogenic supplements is thought to be part of the next generation of orthopedic implants. We previously engineered surface-roughness gradients of average roughness (Ra) varying from the sub-micron to the micrometer range ( 0.5–4.7 lm), and mean distance between peaks (RSm) gradually varying from 214 lm to 33 lm. Here we have screened the ability of such surface-gradients of polycaprolactone to influence the expression of alkaline phosphatase (ALP), collagen type 1 (COL1) and mineralization by hMSCs cultured in dexamethasone (Dex)-deprived osteogenic induction medium (OIM) and in basal growth medium (BGM). Ra 1.53 lm/RSm 79 lm in Dex-deprived OI medium, and Ra 0.93 lm/RSm 135 lm in BGM consistently showed higher effectiveness at supporting the expression of the osteogenic markers ALP, COL1 and mineralization, compared to the tissue culture polystyrene (TCP) control in complete OIM. The superior effectiveness of specific surface-roughness revealed that this strategy may be used as a compelling alternative to soluble osteogenic inducers in orthopedic applications featuring the clinically relevant biodegradable polymer polycaprolactone.

Cardiac involvement in total generalized lipodystrophy (Berardinelli- Seip syndrome)

Total generalized lipodystrophy (Berardinelli--Seip Syndrome) is a rare hereditary disease characterized by insulin-resistant diabetes mellitus and a small quantity of adipose tissue and is of unknown origin. Common cardiovascular alterations related to this syndrome are cardiac hypertrophy and arterial hypertension. This article reports a case of Berardinelli--Seip syndrome and reviews the literature with special emphasis on the cardiovascular manifestations of this syndrome.

Modelos Mixtos-Aditivos Generalizados para el Estudio de Fenómenos Biológicos y Sociales Descriptos por Datos Agregados y/o Longitudinales. Generalized Mixed Additive Models for the Study of Biological and Social Phenomenons from Longitudinal and/or Aggregated Data.

Este proyecto propone extender y generalizar los procesos de estimación e inferencia de modelos aditivos generalizados multivariados para variables aleatorias no gaussianas, que describen comportamientos de fenómenos biológicos y sociales y cuyas representaciones originan series longitudinales y datos agregados (clusters). Se genera teniendo como objeto para las aplicaciones inmediatas, el desarrollo de metodología de modelación para la comprensión de procesos biológicos, ambientales y sociales de las áreas de Salud y las Ciencias Sociales, la condicionan la presencia de fenómenos específicos, como el de las enfermedades.Es así que el plan que se propone intenta estrechar la relación entre la Matemática Aplicada, desde un enfoque bajo incertidumbre y las Ciencias Biológicas y Sociales, en general, generando nuevas herramientas para poder analizar y explicar muchos problemas sobre los cuales tienen cada vez mas información experimental y/o observacional.Se propone, en forma secuencial, comenzando por variables aleatorias discretas (Yi, con función de varianza menor que una potencia par del valor esperado E(Y)) generar una clase unificada de modelos aditivos (paramétricos y no paramétricos) generalizados, la cual contenga como casos particulares a los modelos lineales generalizados, no lineales generalizados, los aditivos generalizados, los de media marginales generalizados (enfoques GEE1 -Liang y Zeger, 1986- y GEE2 -Zhao y Prentice, 1990; Zeger y Qaqish, 1992; Yan y Fine, 2004), iniciando una conexión con los modelos lineales mixtos generalizados para variables latentes (GLLAMM, Skrondal y Rabe-Hesketh, 2004), partiendo de estructuras de datos correlacionados. Esto permitirá definir distribuciones condicionales de las respuestas, dadas las covariables y las variables latentes y estimar ecuaciones estructurales para las VL, incluyendo regresiones de VL sobre las covariables y regresiones de VL sobre otras VL y modelos específicos para considerar jerarquías de variación ya reconocidas. Cómo definir modelos que consideren estructuras espaciales o temporales, de manera tal que permitan la presencia de factores jerárquicos, fijos o aleatorios, medidos con error como es el caso de las situaciones que se presentan en las Ciencias Sociales y en Epidemiología, es un desafío a nivel estadístico. Se proyecta esa forma secuencial para la construcción de metodología tanto de estimación como de inferencia, comenzando con variables aleatorias Poisson y Bernoulli, incluyendo los existentes MLG, hasta los actuales modelos generalizados jerárquicos, conextando con los GLLAMM, partiendo de estructuras de datos correlacionados. Esta familia de modelos se generará para estructuras de variables/vectores, covariables y componentes aleatorios jerárquicos que describan fenómenos de las Ciencias Sociales y la Epidemiología.

Aproximación al diseño de sistemas de bio-reactores para la delignificación de materiales lignocelulósicos y para la decontaminación de suelos y efluentes. Approximation to the design of bio-reactors systems for the delignificación of lignocellulosic materials and for the decontamination of soil and effluents

Los materiales lignocelulósicos residuales de las actividades agroindustriales pueden ser aprovechados como fuente de lignina, hemicelulosa y celulosa. El tratamiento químico del material lignocelulósico se debe enfrentar al hecho de que dicho material es bastante recalcitrante a tal ataque, fundamentalmente debido a la presencia del polímero lignina. Esto se puede lograr también utilizando hongos de la podredumbre blanca de la madera. Estos producen enzimas lignolíticas extracelulares fundamentalmente Lacasa, que oxida la lignina a CO2. Tambien oxida un amplio rango de sustratos ( fenoles, polifenoles, anilinas, aril-diaminas, fenoles metoxi-sustituídos, y otros), lo cual es una buena razón de su atracción para aplicaciones biotecnológicas. La enzima tiene potencial aplicación en procesos tales como en la delignificación de materiales lignocelulósicos y en el bioblanqueado de pulpas para papel, en el tratamiento de aguas residuales de plantas industriales, en la modificación de fibras y decoloración en industrias textiles y de colorantes, en el mejoramiento de alimentos para animales, en la detoxificación de polutantes y en bioremediación de suelos contaminados. También se la ha utilizado en Q.Orgánica para la oxidación de grupos funcionales, en la formación de enlaces carbono- nitrógeno y en la síntesis de productos naturales complejos. HIPOTESIS: Los hongos de podredumbre blanca, y en condiciones óptimas de cultivo producen distintos tipos de enzimas oxidasas, siendo las lacasas las más adecuadas para explorarlas como catalizadores en los siguientes procesos:  Delignificación de residuos de la industria forestal con el fin de aprovechar tales desechos en la alimentación animal.  Decontaminación/remediación de suelos y/o efluentes industriales. Se realizarán los estudios para el diseño de bio-reactores que permitan responder a las dos cuestiones planteadas en la hipótesis. Para el proceso de delignificación de material lignocelulósico se proponen dos estrategias: 1- tratar el material con el micelio del hongo adecuando la provisión de nutrientes para un desarrollo sostenido y favorecer la liberación de la enzima. 2- Utilizar la enzima lacasa parcialmente purificada acoplada a un sistema mediador para oxidar los compuestos polifenólicos. Para el proceso de decontaminación/remediación de suelos y/o efluentes industriales se trabajará también en dos frentes: 3) por un lado, se ha descripto que existe una correlación positiva entre la actividad de algunas enzimas presentes en el suelo y la fertilidad. En este sentido se conoce que un sistema enzimático, tentativamente identificado como una lacasa de origen microbiano es responsable de la transformación de compuestos orgánicos en el suelo. La enzima protege al suelo de la acumulación de compuestos orgánicos peligrosos catalizando reacciones que involucran degradación, polimerización e incorporación a complejos del ácido húmico. Se utilizarán suelos incorporados con distintos polutantes(por ej. policlorofenoles ó cloroanilinas.) 4) Se trabajará con efluentes industriales contaminantes (alpechínes y/o el efluente líquido del proceso de desamargado de las aceitunas). The lignocellulosic raw materials of the agroindustrial activities can be taken advantage as source of lignin, hemicellulose and cellulose. The chemical treatment of this material is not easy because the above mentioned material is recalcitrant enough to such an assault, due to the presence of the lignin. This can be achieved also using the white-rot fungi of the wood. It produces extracellular ligninolitic enzymes, fundamentally Laccase, which oxidizes the lignin to CO2. The enzyme has application in such processes as in the delignification of lignocellulosic materials and in the biobleaching of fibers for paper industry, in the treatment of waste water of industrial plants, in the discoloration in textile industries, in the improvement of food for ruminants, in the detoxification of polutants and in bioremediation of contaminated soils. HYPOTHESIS: The white-rot fungi produce different types of enzymes, being the laccases the most adapted to explore them as catalysts in the following processes:  Delignification of residues of the forest industry in order to take advantage of such waste in the animal feed.  Decontamination of soils and / or waste waters. The studies will be conducted for the design of bio reactors that allow to answer to both questions raised in the hypothesis. For the delignification process of lignocellulosic material they propose two strategies: 1- to treat the material with the fungi 2-to use the partially purified enzyme to oxidize the polyphenolic compounds. For the soil and/or waste water decontamination process, we have: 3- Is know that the enzyme protects to the soil of the accumulation of organic dangerous compounds catalyzing reactions that involve degradation, polymerization and incorporation to complexes of the humic acid. There will be use soils incorporated into different pollutants. 4- We will work with waste waters (alpechins or the green olive debittering effluents.

Lösbarkeit und Finite-Elemente-Approximation eines mathematischen Modells für die Strömung in Magnetfluiddichtungen

Navier-Stokes-Gleichungen, Gleitrandbedingung, Konvektions-Diffusions-Gleichung, Finite-Elemente-Methode, Mehrgitterverfahren, Fehlerabschätzung, Iterative Entkopplung

Simultaneous recording of EEG and fMRI : new approach to remove gradient and ballistocardiogram EEG-artifacts

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2009

Gradient injection in preparative chromatography : exploitation of sample solvents different than the mobile phase

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2010