441 research outputs found

    Estructura del Complejo Alpujárride y observaciones hidrogeológicas al NO de Sierra Tejeda (provincias de Granada y Málaga, Zona Interna Bética)

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    In the NW of Sierra Tejeda (Spain) it is possible differentiate only two Alpujarride tectonic units, i.e. the Almijara and, in an upper position, the Robledal unit, simplifying previous divisions. Hydrogeological data support this interpretation since a hydraulic connection exists between the two areas occupied by marbles (Sierra Tejeda and Rodaderos sectors). Both areas has been previously considered as belonging to two different tectonic units not directly connected. In the Robledal unit, gneisses in the lower part of the lithologic sequence correlate with other units of the Guájares-Jubrique/Los Reales group (upper group of Alpujarride units). Extensional deformations are superposed over these tectonic units, but, according to field observations, they have not the enormous importance attributed to them in previous models, as they do not differentiate new tectonic units, at least in this area. New E-W faults are drawn along the northern edge of Sierra Tejeda, contributing to the westward drift of the Betic Internal Zone.Al NO de Sierra Tejeda solo se pueden diferenciar dos unidades tectónicas alpujárrides, la de Almijara y, sobre ella, la de Robledal, simplificando divisiones previas. Datos hidrogeológicos avalan esta interpretación ya que apuntan a la posible conexión hidráulica entre dos áreas ocupadas por mármoles (sectores de Tejeda y Rodaderos) que previamente han sido consideradas como unidades tectónicas diferentes lo que lo hace improbable. En la unidad Robledal la presencia de gneises en la parte inferior de la secuencia litológica permite su correlación con otras unidades del grupo Guájares-Jubrique/ Los Reales (grupo superior de unidades del Complejo Alpujárride). Deformaciones extensionales se superponen al cabalgamiento de unidades, pero a las que no damos la enorme importancia atribuida en previos modelos, pues no permiten, al menos en esta área, la diferenciación de nuevas unidades tectónicas. Se muestran, además, nuevas fallas E-O situadas al N de Sierra Tejeda, que facilitaron el desplazamiento hacia el oeste de la Zona Interna Bética

    Structure of the Alpujarride Complex and hydrogeological observations to the NW of Sierra Tejeda (Granada and Malaga provinces, Betic Internal Zone, Spain)

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    n the NW of Sierra Tejeda (Spain) it is possible differentiate only two Alpujarride tectonic units, i.e. the Almijara and, in an upper position, the Robledal unit, simplifying previous divisions. Hydrogeological data support this interpretation since a hydraulic connection exists between the two areas occupied by marbles (Sierra Tejeda and Rodaderos sectors). Both areas has been previously considered as belonging to two different tectonic units not directly connected. In the Robledal unit, gneisses in the lower part of the lithologic sequence correlate with other units of the Guájares-Jubrique/Los Reales group (upper group of Alpujarride units). Extensional deformations are superposed over these tectonic units, but, according to field observations, they have not the enormous importance attributed to them in previous models, as they do not differentiate new tectonic units, at least in this area. New E-W faults are drawn along the northern edge of Sierra Tejeda, contributing to the westward drift of the Betic Internal Zone.Al NO de Sierra Tejeda solo se pueden diferenciar dos unidades tectónicas alpujárrides, la de Almijara y, sobre ella, la de Robledal, simplificando divisiones previas. Datos hidrogeológicos avalan esta interpretación ya que apuntan a la posible conexión hidráulica entre dos áreas ocupadas por mármoles (sectores de Tejeda y Rodaderos) que previamente han sido consideradas como unidades tectónicas diferentes lo que lo hace improbable. En la unidad Robledal la presencia de gneises en la parte inferior de la secuencia litológica permite su correlación con otras unidades del grupo Guájares-Jubrique/ Los Reales (grupo superior de unidades del Complejo Alpujárride). Deformaciones extensionales se superponen al cabalgamiento de unidades, pero a las que no damos la enorme importancia atribuida en previos modelos, pues no permiten, al menos en esta área, la diferenciación de nuevas unidades tectónicas. Se muestran, además, nuevas fallas E-O situadas al N de Sierra Tejeda, que facilitaron el desplazamiento hacia el oeste de la Zona Interna Bética

    Autoluminescent Metal-Organic Frameworks (MOFs): Self-Photoemission of a Highly Stable Thorium MOF

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    A novel thorium(IV) metal-organic framework (MOF), Th(2,6-naphtalenedicarboxylate)2, has been synthesized via solvothermal reaction of thorium nitrate and 2,6-naphtalendicarboxilyc acid. This compound shows a new structural arrangement with an interesting topology and an excellent thermal resistance, as the framework is stable in air up to 450 \ub0C. Most notably, this MOF, combining the radioactivity of its metal center and the scintillation property of the ligand, has been proven capable of spontaneous photon emission

    How much effort is required to accurately describe the complex ecology of a rodent‐borne viral disease?

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    We use data collected on 18, 1-ha live trapping grids monitored from 1994 through 2005 and on five of those grids through 2013 in the mesic northwestern United States to illustrate the complexity of the deer mouse (Peromyscus maniculatus)/Sin Nombre virus (SNV) host-pathogen system. Important factors necessary to understand zoonotic disease ecology include those associated with distribution and population dynamics of reservoir species as well as infection dynamics. Results are based on more than 851,000 trap nights, 16,608 individual deer mice and 10,572 collected blood samples. Deer mice were distributed throughout every habitat we sampled and were present during every sampling period in all habitats except high altitude habitats over 1900 m. Abundance varied greatly among locations with peak numbers occurring mostly during fall. However, peak rodent abundance occurred during fall, winter and spring during various years on three grids trapped 12 months/yr. Prevalence of antibodies to SNV averaged 3.9% to 22.1% but no grids had mice with antibodies during every month. The maximum period without antibody-positive mice ranged from 1 to 52 months, or even more at high altitude grids where deer mice were not always present. Months without antibody-positive mice were more prevalent during fall than spring. Population fluctuations were not synchronous over broad geographic areas and antibody prevalences were not well spatially consistent, differing greatly over short distances. We observed an apparently negative, but nonstatistically significant relationship between average antibody prevalence and average deer mouse population abundance and a statistically significant positive relationship between the average number of antibody positive mice and average population abundance. We present data from which potential researchers can estimate the effort required to adequately describe the ecology of a rodentborne viral system. We address different factors affecting population dynamics and hantavirus antibody prevalence and discuss the path to understanding a complex rodent-borne disease system as well as the obstacles in that path.Fil: Douglass, Richard J.. University of Montana; Estados UnidosFil: Vadell, María Victoria. Universidad Nacional de San Martín. Instituto de Investigaciones e Ingeniería Ambiental. Laboratorio de Ecología de Enfermedades Transmitidas por Vectores; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    High-throughput screening of the thermoelastic properties of ultrahigh-temperature ceramics

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    Ultrahigh-temperature ceramics (UHTCs) are a group of materials with high technological interest because of their applications in extreme environments. However, their characterization at high temperatures represents the main obstacle for their fast development. Obstacles are found from an experimental point of view, where only few laboratories around the world have the resources to test these materials under extreme conditions, and also from a theoretical point of view, where actual methods are expensive and difficult to apply to large sets of materials. Here, a new theoretical high-throughput framework for the prediction of the thermoelastic properties of materials is introduced. This approach can be systematically applied to any kind of crystalline material, drastically reducing the computational cost of previous methodologies up to 80% approximately. This new approach combines Taylor expansion and density functional theory calculations to predict the vibrational free energy of any arbitrary strained configuration, which represents the bottleneck in other methods. Using this framework, elastic constants for UHTCs have been calculated in a wide range of temperatures with excellent agreement with experimental values, when available. Using the elastic constants as the starting point, other mechanical properties such a bulk modulus, shear modulus, or Poisson ratio have been also explored, including upper and lower limits for polycrystalline materials. Finally, this work goes beyond the isotropic mechanical properties and represents one of the most comprehensive and exhaustive studies of some of the most important UHTCs, charting their anisotropy and thermal and thermodynamical properties.Ministerio de Ciencia e Innovación PID2019-106871GB-I00European Union 752608Red Española de Supercomputación QS-2019-2-0006, QS-2019-3-0021, QS-2020-2-003

    Inhibition of ATPase from chloroplasts by a hydroxamic acid from Gramineae.

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    Abstract-DIMBOA (2,4-dihydroxy-7-methoxy-l,4-benzoxazin-3-one), a hydroxamic acid from the Gramineae involved in the resistance of cereals to aphids, inhibits energy transfer reactions. In this paper the effect of DIMBOA on the ATPase activity of chloroplast coupling factor 1 (CF,) was studied. A rapid inactivation of the enzyme was observed which increased with the concentration of DIMBOA. This inactivation was reversed by dilution and by filtration of the inhibitor. The inactivation was partially prevented by pre-treatment of the enzyme with iodoacetamide. A slower simultaneous inactivation was observed which followed pseudo-first order kinetics. It is suggested that part of the rapid inhibition of CF, ATPase caused by DIMBOA is due to its reaction with sulthydryl groups on the enzyme. These reactions of DIMBOA may explain some of the inhibitory properties of DIMBOA on a wide range of organisms

    Transbronchial and transesophageal fine-needle aspiration using a single ultrasound bronchoscope in the diagnosis of locoregional recurrence of surgically-treated lung cancer

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    The present study sought to evaluate the usefulness of EBUS-TBNA in the diagnosis of locoregional recurrence of lung cancer in a cohort of lung cancer patients who were previously treated surgically, and describe our initial experience of EUS-B-FNA in this clinical scenario. We retrospectively studied the clinical records of all patients with a previous surgically-treated lung cancer who were referred to our bronchoscopy unit after suspicion of locoregional recurrence. The diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy of EBUS-TBNA for the diagnosis of locoregional recurrence were evaluated. Seventy-three patients were included. EBUS-TBNA confirmed malignancy in 40 patients: 34 confirmed to have locoregional recurrence, six had metachronous tumours. Of the 33 patients with non-malignant EBUS-TBNA; 2 had specific non-malignant diseases, 26 underwent radiological follow up and 5 patients underwent surgery. Of the 26 patients who had radiological follow up; 18 remained stable, three presented thoracic radiological progression and 5 presented extrathoracic progression. Of the 5 patients who underwent surgery; 3 had metachronous tumours, one confirmed to be a true negative and one presented nodal invasion. Seven patients underwent EUS-B-FNA, four of them confirmed to have recurrence. The sensitivity, specificity, NPV, PPV and overall accuracy of EBUS-TBNA for the diagnosis of locoregional recurrence were 80.9, 100, 69.2, 100 and 86.6% respectively. EBUS-TBNA is an accurate procedure for the diagnosis of locoregional recurrence of surgically-treated lung cancer. EUS-B-FNA combined with EBUS-TBNA broads the diagnostic yield of EBUS-TBNA alone

    Boundary value problems for second order linear difference equations: application to the computation of the inverse of generalized Jacobi matrices

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    We have named generalized Jacobi matrices to those that are practically tridiagonal, except for the two final entries and the two first entries of its first andits last row respectively. This class of matrices encompasses both standard Jacobiand periodic Jacobi matrices that appear in many contexts in pure and appliedmathematics. Therefore, the study of the inverse of these matrices becomes ofspecific interest. However, explicit formulas for inverses are known only in a fewcases, in particular when the coefficients of the diagonal entries are subjected tosome restrictions.We will show that the inverse of generalized Jacobi matrices can be raisedin terms of the resolution of a boundary value problem associated with a secondorder linear difference equation. In fact, recent advances in the study of lineardifference equations, allow us to compute the solution of this kind of boundaryvalue problems. So, the conditions that ensure the uniqueness of the solution ofthe boundary value problem leads to the invertibility conditions for the matrix,whereas that solutions for suitable problems provide explicitly the entries of theinverse matrix.Peer ReviewedPostprint (author's final draft

    EEG Microstates Change in Response to Increase in Dopaminergic Stimulation in Typical Parkinson’s Disease Patients.

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    Objectives: Characterizing pharmacological response in Parkinson’s Disease (PD) patients may be a challenge in early stages but gives valuable clues for diagnosis. Neurotropic drugs may modulate Electroencephalography (EEG) microstates (MS). We investigated EEG-MS default-mode network changes in response to dopaminergic stimulation in PD. Methods: Fourteen PD subjects in HY stage III or less were included, and twentyone healthy controls. All patients were receiving dopaminergic stimulation with levodopa or dopaminergic agonists. Resting EEG activity was recorded before the first daily PD medication dose and 1 h after drug intake resting EEG activity was again recorded. Time and frequency variables for each MS were calculated. Results: Parkinson’s disease subjects MS A duration decreases after levodopa intake, MS B appears more often than before levodopa intake. MS E was not present, but MS G was. There were no significant differences between control subjects and patients after medication intake. Conclusion: Clinical response to dopaminergic drugs in PD is characterized by clear changes in MS profile. Significance: This work demonstrates that there are clear EEG MS markers of PD dopaminergic stimulation state. The characterization of the disease and its response to dopaminergic medication may be of help for early therapeutic diagnosis.post-print606 K
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