637 research outputs found

    Ultrasonographic assessment of the ovarian response in eCG-treated goats

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    A study was conducted to evaluate the accuracy of ultrasonographic evaluation of ovulation rate during the early luteal phase of does and to estimate the reliability of ultrasonic scanning to differentiate between the corpus luteum and luteinized follicles. Both ultrasonographic and laparoscopic observations of ovarian structures and radioimmunoassays of progesterone in plasma were performed in 47 goats on day 7 after estrus synchronization using intravaginal FGA sponges and eCG. Ultrasonographic scanning allowed the determination of the presence or absence of ovulation. Total ef®ciency in detecting the occurrence of multiple ovulations was 87.5%. However, accuracy to establish the number of corpora lutea decreased to 23.5% in goats with three or more ovulations, due to an increasing underestimation as the number of corpora lutea in the ovary increased (p<0.001). Ultrasonographic assessment of ovulation rate can be used to determine if a goat has ovulated or if multiple ovulations have occurred, but not to establish the precise number of corpora lutea. Evaluation of the ratio between cavity diameter and total luteal-tissue diameter is useful in distinguishing between corpora lutea and luteinized follicles, since the diameter differed between the two (0.36 0.21 vs. 0.64 0.16, respectively; p<0.005)

    Management of uncertain pairwise comparisons in AHP through probabilistic concepts

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    [EN] Fast and judicious decision-making is paramount for the success of many activities and processes. However, various degrees of difficulty may affect the achievement of effective and optimal solutions. Decisions should ideally meet the best trade-off among as many of the involved factors as possible, especially in the case of complex problems. Substantial cognitive and technical skills are indispensable, while not always sufficient, to carry out optimal evaluations. One of the most common causes of wrong decisions derives from uncertainty and vagueness in making forecasts or attributing judgments. The literature shows numerous efforts towards the optimization and modeling of uncertain contexts by means of probabilistic approaches. This paper proposes the use of probability theory to estimate uncertain expert judgments within the framework of the analytic hierarchy process and, more specifically, within a linearization scheme developed by the authors. After describing the necessary probabilistic concepts of interest, the main results are developed. These results can be summarized as using various kinds of random variables with uncertainty embodied in undecided pairwise comparisons. A case study focused on the maintenance management of an industrial water distribution system exemplifies the approach.Benítez López, J.; Carpitella, S.; Certa, A.; Izquierdo Sebastián, J. (2019). Management of uncertain pairwise comparisons in AHP through probabilistic concepts. Applied Soft Computing. 78:274-285. https://doi.org/10.1016/j.asoc.2019.02.020S2742857

    MR imaging features of high-grade gliomas in murine models: How they compare with human disease, reflect tumor biology, and play a role in preclinical trials

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    Murine models are the most commonly used and best investigated among the animal models of HGG. They constitute an important weapon in the development and testing of new anticancer drugs and have long been used in preclinical trials. Neuroimaging methods, particularly MR imaging, offer important advantages for the evaluation of treatment response: shorter and more reliable treatment end points and insight on tumor biology and physiology through the use of functional imaging DWI, PWI, BOLD, and MR spectroscopy. This functional information has been progressively consolidated as a surrogate marker of tumor biology and genetics and may play a pivotal role in the assessment of specifically targeted drugs, both in clinical and preclinical trials. The purpose of this Research Perspectives was to compile, summarize, and critically assess the available information on the neuroimaging features of different murine models of HGGs, and explain how these correlate with human disease and reflect tumor biology.This work was supported by the Programme for Advanced Medical Education from Fundaçâo Champalimaud, Fundaçâo Calouste Gulbenkian, Ministério da Saúde and Fundaçâo para a Ciência e Tecnologia, Portugal, to the first author (A.R.B.), and by grants from the Spanish Ministry of Science and Innovation SAF 2008–01327 and the Community of Madrid S-BIO-2006–0170, to the last author (S.G.C.).Peer Reviewe

    MR imaging features of high-grade gliomas in murine models: How they compare with human disease, reflect tumor biology, and play a role in preclinical trials

    Get PDF
    Murine models are the most commonly used and best investigated among the animal models of HGG. They constitute an important weapon in the development and testing of new anticancer drugs and have long been used in preclinical trials. Neuroimaging methods, particularly MR imaging, offer important advantages for the evaluation of treatment response: shorter and more reliable treatment end points and insight on tumor biology and physiology through the use of functional imaging DWI, PWI, BOLD, and MR spectroscopy. This functional information has been progressively consolidated as a surrogate marker of tumor biology and genetics and may play a pivotal role in the assessment of specifically targeted drugs, both in clinical and preclinical trials. The purpose of this Research Perspectives was to compile, summarize, and critically assess the available information on the neuroimaging features of different murine models of HGGs, and explain how these correlate with human disease and reflect tumor biology.This work was supported by the Programme for Advanced Medical Education from Fundaçâo Champalimaud, Fundaçâo Calouste Gulbenkian, Ministério da Saúde and Fundaçâo para a Ciência e Tecnologia, Portugal, to the first author (A.R.B.), and by grants from the Spanish Ministry of Science and Innovation SAF 2008–01327 and the Community of Madrid S-BIO-2006–0170, to the last author (S.G.C.).Peer Reviewe

    Magnetite mineralization inside cross-linked protein crystals

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    Crystallization in confined spaces is a widespread process in nature that also has important implications for the stability and durability of many man-made materials. It has been reported that confinement can alter essential crystallization events, such as nucleation and growth and, thus, have an impact on crystal size, polymorphism, morphology, and stability. Therefore, the study of nucleation in confined spaces can help us understand similar events that occur in nature, such as biomineralization, design new methods to control crystallization, and expand our knowledge in the field of crystallography. Although the fundamental interest is clear, basic models at the laboratory scale are scarce mainly due to the difficulty in obtaining well-defined confined spaces allowing a simultaneous study of the mineralization process outside and inside the cavities. Herein, we have studied magnetite precipitation in the channels of cross-linked protein crystals (CLPCs) with different channel pore sizes, as a model of crystallization in confined spaces. Our results show that nucleation of an Fe-rich phase occurs inside the protein channels in all cases, but, by a combination of chemical and physical effects, the channel diameter of CLPCs exerted a precise control on the size and stability of those Fe-rich nanoparticles. The small diameters of protein channels restrain the growth of metastable intermediates to around 2 nm and stabilize them over time. At larger pore diameters, recrystallization of the Fe-rich precursors into more stable phases was observed. This study highlights the impact that crystallization in confined spaces can have on the physicochemical properties of the resulting crystals and shows that CLPCs can be interesting substrates to study this process

    Consistent Clustering of Elements in Large Pairwise Comparison Matrices

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    [EN] In multi-attribute decision making the number of decision elements under consideration may be huge, especially for complex, real-world problems. Typically these elements are clustered and then the clusters organized hierarchically to reduce the number of elements to be simultaneously handled. These decomposition methodologies are intended to bring the problem within the cognitive ability of decision makers. However, such methodologies have disadvantages, and it may happen that such a priori clustering is not clear, and/or the problem has previously been addressed without any grouping action. This is the situation for the case study we address, in which a panel of experts gives opinions about the operation of 15 previously established district metered areas in a real water distribution system. Large pairwise comparison matrices may also be found when building comparisons of elements using large bodies of information. In this paper, we address a consistent compression of an AHP comparison matrix that collapses the judgments corresponding to a given number of compared elements. As a result, an a posteriori clustering of various elements becomes possible. In our case study, such a clustering offers several added benefits, including the identification of hidden or unknown criteria to cluster the considered elements of the problem. (C) 2018 Elsevier B.V. All rights reserved.Benítez López, J.; Carpitella, S.; Certa, A.; Ilaya-Ayza, AE.; Izquierdo Sebastián, J. (2018). Consistent Clustering of Elements in Large Pairwise Comparison Matrices. Journal of Computational and Applied Mathematics. 343:98-112. https://doi.org/10.1016/j.cam.2018.04.041S9811234

    A hybrid multicriteria approach to GPR image mining applied to water supply system maintenance

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    [EN] Data processing techniques for Ground Penetrating Radar (GPR) image mining provide essential information to optimize maintenance management of Water Supply Systems (WSSs). These techniques aim to elaborate on radargrams in order to produce meaningful graphical representations of critical buried components of WSSs. These representations are helpful non-destructive evaluation tools to prevent possible failures in WSSs by keeping them adequately monitored. This paper proposes an integrated multi-criteria decision making (MCDM) approach to prioritize various data processing techniques by means of ranking their outputs, namely their resulting GPR image representations. The Fuzzy Analytic Hierarchy Process (FAHP) is applied to weight various evaluation criteria, with the purpose of managing vagueness and uncertainty characterizing experts' judgments. Then, the Elimination Et Choix Traduisant la REalite III (ELECTRE III) method is used to obtain the final ranking of alternatives. A real case study, focusing on a set of four GPR images as outputs of different data processing techniques, is presented to prove the usefulness of the proposed hybrid approach. In particular, the GPR images are ranked according the evaluation of five criteria namely visualization, interpretation, identification of features, extraction of information and affordability. The findings offer a structured support in selecting the most suitable data processing technique(s) to explore WSS underground. In the presented case, two options, namely the variance filter and the subtraction methods, offer the best results. (C) 2018 Elsevier B.V. All rights reserved.Part of this work has been developed under the support of the Universitat Politecnica de Valencia, Valencia (Spain), grant: UPV mobility program for PhD students, awarded to the first author, and of Fundacion Carolina PhD, within its short stage scholarship program awarded to the second author.Carpitella, S.; Ocaña-Levario, SJ.; Benítez López, J.; Certa, A.; Izquierdo Sebastián, J. (2018). A hybrid multicriteria approach to GPR image mining applied to water supply system maintenance. Journal of Applied Geophysics. 159:754-764. https://doi.org/10.1016/j.jappgeo.2018.10.021S75476415

    Evaluation of the small ruminants cystic ovarian disease using transrectal ultrasonography

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    A transrectal ultrasonic method using a 7.5 MHz linear-array transducer was used in 194 ewes and 39 goats to study the characteristc of cystic ovaries. Cystic structures found on the ovaries include follicular cysts and luteinised cysts. Follicular cysts showed up as non-echogenic structures with a 1.5 ± 0.4 cm diameter. The cysts luteinised showed an echogenic rim of tissue, ranging from 2- 3 mm, around the cyst; the central cavity was 1±0.2 cm. In total, 4.1 percent of ewes and 5.1 percent of goats exhibited follicular cysts. Only 1 percent of ewes and 2.6 percent of goats showed luteinised cysts. In conclusion, the results demonstrated that transrectal ultrasonography provides a noninvasive form of visual access to the ovary from small ruminants, to evaluate pathological changes before the aplication of superovulation treatments and embryo transfer.Se ha realizado un estudio de las características ecográficas de estructuras quísticas ováricas en 194 ovejas y 39 cabras de diferentes razas y procedentes de distintas zonas geográficas, con el objeto de valorar la ecografía transrectal con sondas de alta resolución (7,5 MHz) como criterio de selección de animales destinados a programas de superovulación y recogida de embriones. Los quistes foliculares tenían una incidencia de presentación del 4,1 p.100 en las ovejas y del 5,1 p.100 en las cabras, presentándose ecográficamente con una morfología esférica anecoica de 1,5±0,4 cm de diámetro, con paredes finas y generalmente bien definidas. Los quistes luteínicos tuvieron una presentación del 1 p.100 en las ovejas y del 2,6 p.100 en las cabras. Ecográficamente se caracterizaban por presentar una cavidad central anecógena 1±0,2 cm, rodeada por un anillo ecogénico de 2-3 mm de espesor. No había diferencias significativas en la frecuencia de presentación de quistes ováricos entre ambas especies. Los resultados muestran que la ecografía transrectal con sondas de alta resolución permite la realización de un diagnóstico eficaz de la patología quística ovárica en los pequeños rumiantes, siendo recomendable esta metodología en la selección de hembras donantes y receptoras

    Nonlinearity-induced synchronization enhancement in micromechanical oscillators

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    An autonomous oscillator synchronizes to an external harmonic force only when the forcing frequency lies within a certain interval - known as the synchronization range - around the oscillator's natural frequency. Under ordinary conditions, the width of the synchronization range decreases when the oscillation amplitude grows, which constrains synchronized motion of micro- and nanomechanical resonators to narrow frequency and amplitude bounds. Here, we show that nonlinearity in the oscillator can be exploited to manifest a regime where the synchronization range increases with increasing oscillation amplitude. Experimental data are provided for self-sustained micromechanical oscillators operating in this regime, and analytical results show that nonlinearities are the key determinants of this effect. Our results provide a new strategy to enhance the synchronization of micromechanical oscillators by capitalizing on their intrinsic nonlinear dynamics.Fil: Antonio, Dario. Argonne National Laboratory; Estados UnidosFil: Czaplewski, David A.. Argonne National Laboratory; Estados UnidosFil: Guest, Jeffrey R.. Argonne National Laboratory; Estados UnidosFil: López, Daniel. Argonne National Laboratory; Estados UnidosFil: Arroyo, Sebastián Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Zanette, Damian Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin
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