1,204 research outputs found

    PROPUESTA DE ALGORITMO DE RECONSTRUCCIÓN DE EVENTOS PARA ESTUDIAR LA EVOLUCIÓN DE LAS CÉLULAS CANCERÍGENAS

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    In this work, a general algorithm is proposed to design the reconstruction of chemical/physical/biological process events as one of the most complicated today: the evolution of cancer cells. Studying the evolution of the boundary curves it is possible to make a three-dimensional (3D) integration, in addition the 3D figure obtained can be explained through a mathematical model to estimate its geometric evolution after physical/chemical reactions. In this work, there are analyzed images of each stage of the process based on the evolution of cancer cells. Each image was processed in order to obtain a mathematical equation as a reference to understand the geometry of the 3D structure based on its 2D image for each stage. On the other side, with this information and the processing of each stage image, a mathematical equation was achieved to describe the geometry of the structure between stages by "Optimal Prediction Analysis" which is so important to gain understanding of the geometry of the structure with the internal process.En este trabajo se propone un algoritmo general para diseñar la reconstrucción de eventos de proceso químico/físico/biológico como uno de los más complicados hoy en día: la "evolución de las células cancerígenas". Estudiando la evolución de las curvas de frontera es posible hacer una integración en tres dimensiones (3D), además la cifra 3D obtenida se puede explicar a través de un modelo matemático para estimar su evolución geométrica después de reacciones físicas/químicas. En este trabajo, hay imágenes analizadas de cada etapa del proceso basadas en la evolución de las células cancerosas. Cada imagen fue procesada con el fin de obtener una ecuación matemática como referencia para entender la geometría de la estructura 3D basada en su imagen 2D para cada etapa. En el otro lado, con esta información y el procesamiento de cada imagen de etapa, se logró una ecuación matemática para describir la geometría de la estructura entre etapas mediante "Análisis de Predicción Óptima" que es tan importante para obtener la comprensión de la geometría de la estructura con el proceso interno

    Towards an optimal design of target for tsetse control: comparisons of novel targets for the control of palpalis group tsetse in West Africa

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    Background: Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices. Methodology/Principal Findings: Experiments were performed on three tsetse species, namely Glossina palpalis gambiensis and G. tachinoides in Burkina Faso and G. p. palpalis in Côte d'Ivoire. The 1×1 m2 black blue black target commonly used in W. Africa was used as the standard, and effects of changes in target size, shape, and the use of netting instead of black cloth were measured. Regarding overall target shape, we observed that horizontal targets (i.e. wider than they were high) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones (i.e. higher than they were wide) (P<0.001). For the three tsetse species including G. p. palpalis, catches were highly correlated with the size of the target. However, beyond the size of 0.75 m, there was no increase in catches. Replacing the black cloth of the target by netting was the most cost efficient for all three species. Conclusion/Significance: Reducing the size of the current 1*1 m black-blue-black target to horizontal designs of around 50 cm and replacing black cloth by netting will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa

    Fresnel Representation of the Wigner Function: An Operational Approach

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    We present an operational definition of the Wigner function. Our method relies on the Fresnel transform of measured Rabi oscillations and applies to motional states of trapped atoms as well as to field states in cavities. We illustrate this technique using data from recent experiments in ion traps [D. M. Meekhof et al., Phys. Rev. Lett. 76, 1796 (1996)] and in cavity QED [B. Varcoe et al., Nature 403, 743 (2000)]. The values of the Wigner functions of the underlying states at the origin of phase space are W(0)=+1.75 for the vibrational ground state and W(0)=-1.4 for the one-photon number state. We generalize this method to wave packets in arbitrary potentials.Comment: 4 pages include 4 figures, submitted to PR

    Determination of the high-pressure crystal structure of BaWO4 and PbWO4

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    We report the results of both angle-dispersive x-ray diffraction and x-ray absorption near-edge structure studies in BaWO4 and PbWO4 at pressures of up to 56 GPa and 24 GPa, respectively. BaWO4 is found to undergo a pressure-driven phase transition at 7.1 GPa from the tetragonal scheelite structure (which is stable under normal conditions) to the monoclinic fergusonite structure whereas the same transition takes place in PbWO4 at 9 GPa. We observe a second transition to another monoclinic structure which we identify as that of the isostructural phases BaWO4-II and PbWO4-III (space group P21/n). We have also performed ab initio total energy calculations which support the stability of this structure at high pressures in both compounds. The theoretical calculations further find that upon increase of pressure the scheelite phases become locally unstable and transform displacively into the fergusonite structure. The fergusonite structure is however metastable and can only occur if the transition to the P21/n phases were kinetically inhibited. Our experiments in BaWO4 indicate that it becomes amorphous beyond 47 GPa.Comment: 46 pages, 11 figures, 3 table

    How do tsetse recognise their hosts? The role of shape in the responses of tsetse (Glossina fuscipes and G. palpalis) to artificial hosts

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    Palpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting .95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the fly’s host-seeking behaviour.Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m2 to 1.0 m2. For both species, increasing the size of a square target from 0.01 m2 (dimensions = 0.1 x 0.1 m) to 1.0 m2 (1.0 x 1.0 m) increased the catch ,4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide x 0.5 m high) caught, 1.8x more tsetse than vertical ones (0.5 m wide x 1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25 x 0.25 m2. The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT

    Quantum computation with two-level trapped cold ions beyond Lamb-Dicke limit

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    We propose a simple scheme for implementing quantum logic gates with a string of two-level trapped cold ions outside the Lamb-Dicke limit. Two internal states of each ion are used as one computational qubit (CQ) and the collective vibration of ions acts as the information bus, i.e., bus qubit (BQ). Using the quantum dynamics for the laser-ion interaction as described by a generalized Jaynes-Cummings model, we show that quantum entanglement between any one CQ and the BQ can be coherently manipulated by applying classical laser beams. As a result, universal quantum gates, i.e. the one-qubit rotation and two-qubit controlled gates, can be implemented exactly. The required experimental parameters for the implementation, including the Lamb-Dicke (LD) parameter and the durations of the applied laser pulses, are derived. Neither the LD approximation for the laser-ion interaction nor the auxiliary atomic level is needed in the present scheme.Comment: 12 pages, no figures, to appear in Phys. Rev.

    ANÁLISIS TÉRMICO ÓPTIMO DE LA TRANSMISIÓN DEL CORONAVIRUS (COVID-19) DURANTE DÍAS DE CUARENTENA EN PERÚ

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    In this research is analyzed COVID-19 transmission by thermodynamic and energy balance between geographic areas and its correlation with possible COVID-19 transmission between 2 persons at least. In order to achieve parameters for medical doctors, as for example the minimal distance among two infected people, who have this virus, there were designed mathematical models that were based in statistical data to get information of COVID-19 propagation as the dependence on temperature of geographic areas, moreover the thermal effect of the minimal distance between two people avoiding COVID-19 infection. With this work, answers are sought to the questions: if it could be possible to find a relation between temperature and virus transmission? Or if it could be possible to get a correlation variable among thermal variables with minimal distance separation (it was described above) for two people? Hence, it is waited answers to these questions owing to be support for medical doctors, who are trying to find solution against COVID-19 propagation. It is worth mentioning that this research can be extended to more complex areas such as street markets, street fair or enclosed marketplaces, where products and services are sold, moreover, not every area has an air conditioning system in Peru. Nevertheless, in this research it is achieved the technique, how to solve this task: to obtain appropriated ventilation parameters as the dependence on the minimal distance that people need to be separated, according to avoid virus transmission between each other. Furthermore, it is suggested some geometrical/material characteristics for air filters and ultraviolet (UV) disinfection at the entrance of the main air duct.En esta investigación se analiza la transmisión de COVID-19 por equilibrio termodinámico y energético entre áreas geográficas y su correlación con la posible transmisión de COVID-19 entre al menos 2 personas. Con el fin de lograr parámetros para los médicos, como por ejemplo la distancia mínima entre dos personas infectadas que tienen este virus, se diseñaron modelos matemáticos basados en datos estadísticos para obtener información sobre la propagación de COVID-19 como la dependencia de la temperatura de áreas geográficas, además, el efecto térmico de la distancia mínima entre dos personas evitando la infección por COVID-19. Con este trabajo, se buscan respuestas a las preguntas: ¿Si fuera posible encontrar una relación entre la temperatura y la transmisión del virus? ¿O si fuera posible obtener una variable de correlación entre variables térmicas con una separación mínima de distancia (se describió anteriormente) para dos personas? Por lo tanto, se esperan respuestas a estas preguntas debido al apoyo de los médicos, que están tratando de encontrar una solución contra la propagación de COVID-19. Vale la pena mencionar que esta investigación puede extenderse a áreas más complejas como mercados y ferias abiertas al aire libre o mercados cerrados, donde se venden productos y servicios, además, no todas las áreas tienen un sistema de aire acondicionado en Perú. Sin embargo, en esta investigación se logra la técnica, cómo resolver esta tarea: obtener parámetros de ventilación apropiados como la dependencia de la distancia mínima que las personas necesitan para separarse, para evitar la transmisión del virus entre sí. Además, se sugieren algunas características geométricas / materiales para los filtros de aire y la desinfección mediante ultravioleta (UV) en la entrada del conducto de aire principal

    Geochemistry and microbiology of tropical serpentine soils in the Santa Elena Ophiolite, a landscape-biogeographical approach

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    This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: The datasets supporting the conclusions of this article are available in https://doi.org/10.17632/w6cdt3sn99.4 with CC BY 4.0 license, in NCBI SRA (Sequence Read Archive; http://www.ncbi.nlm.nih.gov/sra/, under the project accession number: PRJNA606410) and within the article and its additional file.The Santa Elena Ophiolite is a well-studied ultramafic system in Costa Rica mainly comprised of peridotites. Here, tropical climatic conditions promote active laterite formation processes, but the biogeochemistry of the resulting serpentine soils is still poorly understood. The aim of this study was to characterize the soil geochemical composition and microbial community of contrasting landscapes in the area, as the foundation to start exploring the biogeochemistry of metals occurring there. The soils were confirmed as Ni-rich serpentine soils but differed depending on their geographical location within the ophiolite area, showing three serpentine soil types. Weathering processes resulted in mountain soils rich in trace metals such as cobalt, manganese and nickel. The lowlands showed geochemical variations despite sharing similar landscapes: the inner ophiolite lowland soils were more like the surrounding mountain soils rather than the north lowland soils at the border of the ophiolite area, and within the same riparian basin, concentrations of trace metals were higher downstream towards the mangrove area. Microbial community composition reflected the differences in geochemical composition of soils and revealed potential geomicrobiological inputs to local metal biogeochemistry: iron redox cycling bacteria were more abundant in the mountain soils, while more manganese-oxidizing bacteria were found in the lowlands, with the highest relative abundance in the mangrove areas. The fundamental ecological associations recorded in the serpentine soils of the Santa Elena Peninsula, and its potential as a serpentinization endemism hotspot, demonstrate that is a model site to study the biogeochemistry, geomicrobiology and ecology of tropical serpentine areas.Ministerio de Ciencia, Tecnología y Telecomunicaciones (MICITT), Government of Costa RicaUniversidad de Costa RicaMICITTNatural Environment Research Council (NERC

    Improving the cost-effectiveness of visual devices for the control of Riverine tsetse flies, the major vectors of Human African Trypanosomiasis

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    Control of the Riverine (Palpalis) group of tsetse flies is normally achieved with stationary artificial devices such as traps or insecticide-treated targets. The efficiency of biconical traps (the standard control device), 161 m black targets and small 25625 cm targets with flanking nets was compared using electrocuting sampling methods. The work was done on Glossina tachinoides and G. palpalis gambiensis (Burkina Faso), G. fuscipes quanzensis (Democratic Republic of Congo), G. f. martinii (Tanzania) and G. f. fuscipes (Kenya). The killing effectiveness (measured as the catch per m2 of cloth) for small targets plus flanking nets is 5.5–15X greater than for 1 m2 targets and 8.6–37.5X greater than for biconical traps. This has important implications for the costs of control of the Riverine group of tsetse vectors of sleeping sickness

    High-pressure x-ray diffraction and ab initio study of Ni2Mo3N, Pd2Mo3N, Pt2Mo3N, Co3Mo3N, and Fe3Mo3N: Two families of ultra-incompressible bimetallic interstitial nitrides

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    We have studied by means of high-pressure x-ray diffraction the structural stability of Ni2Mo3N, Co3Mo3N, and Fe3Mo3N. We also report ab initio computing modeling of the high-pressure properties of these compounds, Pd2Mo3N, and Pt2Mo3N. We have found that the nitrides remain stable in the ambient-pressure cubic structure at least up to 50 GPa and determined their equation of state. All of them have a bulk modulus larger than 300 GPa. Single-crystal elastic constants have been calculated in order to quantify the stiffness of the investigated nitrides. We found that they should have a Vickers hardness similar to that of cubic spinel nitrides like gamma-Si3N4Comment: 25 pages, 6 figures, 3 table
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