Geomorphological mapping of granite caves

[Abstract] The aim is to develop a mapping which represents the relief and the form (morphology) of granite caves and associated superficial structures

Analysis of the relationship between land surface temperature and wildfire severity in a series of landsat images

The paper assesses spatio-temporal patterns of land surface temperature (LST) and fire severity in the Las Hurdes wildfire of Pinus pinaster forest, which occurred in July 2009, in Extremadura (Spain), from a time series of fifteen Landsat 5 TM images corresponding to 27 post-fire months. The differenced Normalized Burn Ratio (dNBR) was used to evaluate burn severity. The mono-window algorithm was applied to estimate LST from the Landsat thermal band. The burned zones underwent a significant increase in LST after fire. Statistically significant differences have been detected between the LST within regions of burn severity categories. More substantial changes in LST are observed in zones of greater fire severity, which can be explained by the lower emissivity of combustion products found in the burned area and changes in the energy balance related to vegetation removal. As time progresses over the 27 months after fire, LST differences decrease due to vegetation regeneration. The differences in LST and Normalized Difference Vegetation Index (NDVI) values between burn severity categories in each image are highly correlated (r = 0.84). Spatial patterns of severity and post-fire LST obtained from Landsat time series enable an evaluation of the relationship between these variables to predict the natural dynamics of burned areas

Reproducibility of extracellular vesicle research

Publisher Copyright: © 2022Cells release membrane-delimited particles into the environment. These particles are called “extracellular vesicles” (EVs), and EVs are present in fluids contacting cells, including body fluids and conditioned culture media. Because EVs change and contribute to health and disease, EVs have become a hot topic. From the thousands of papers now published on EVs annually, one easily gets the impression that EVs provide biomarkers for all diseases, and that EVs are carriers of all relevant biomolecules and are omnipotent therapeutics. At the same time, EVs are heterogeneous, elusive and difficult to study due to their physical properties and the complex composition of their environment. This overview addresses the current challenges encountered when working with EVs, and how we envision that most of these challenges will be overcome in the near future. Right now, an infrastructure is being developed to improve the reproducibility of EV measurement results. This infrastructure comprises expert task forces of the International Society of Extracellular Vesicles (ISEV) developing guidelines and recommendations, instrument calibration, standardized and transparent reporting, and education. Altogether, these developments will support the credibility of EV research by introducing robust reproducibility, which is a prerequisite for understanding their biological significance and biomarker potential.Peer reviewe

Tratamiento de fracturas toracolumbares: nuestra experiencia en el periodo 2000-2003. Protocolo de actuación

Presentamos una revisión de los resultados obtenidos en pacientes intervenidos de fracturas tóraco-lumbares durante los años 2000 a 2003, en ambos inclusive, por el servicio de Traumatología y Cirugía Ortopédica del Hospital Universitario Virgen de las Nieves de Granada; así como el protocolo seguido en el manejo diagnóstico-terapéutico de este tipo de pacientes. Las fracturas más frecuentes fueron en L1 y del tipo A3 de la clasificación AO. La vía de abordaje más utilizada fue la posterior (138 casos). En 132 casos se instrumentó la vértebra fracturada y en 39 casos fue necesaria la descompresión. El índice sagital medio preoperatorio fue de 17,5º y el postoperatorio de 3,5º. La pérdida de altura vertebral preoperatoria fue del 52% y del 14% al final del tratamiento. En 39 pacientes con déficit neurológico se realizó descompresión. En el 79% de los casos los resultados fueron excelentes y en el resto regulares o malos.We present the results of surgical treatment in patients with thoraco-lumbar fractures operated on between the years 2000 and 2003 at the Orthopedic and Traumatology Department of the hospital Virgen de las Nieves Hospital of Granada, Spain. The diagnosis and therapeutic protocol of this type of patients is also evaluated. A3 type from AO classification fracture of L1, was the most frequent injury. Posterior surgical approach of the spine was mainly used (138 cases), in 132 cases the fracture was stabilized by means of internal fixation and 39 cases required decompression of the lumbar canal. The average sagital index was 17,5º preoperative and 3,5º after surgery. The average loss of height was 52% preoperative and 14% at the end of treatment. In 39 surgical decompression was indicated for neurological impairment. Excellent results were obtained in 79% of the cases, the rest were fair and poor

Tratamiento y prevención de las enfermedades cardiovasculares: efecto de los ácidos grasos omega 3 frente a la hipoxia

La cardiopatía isquémica y el accidente cerebrovascular se presentan como las primeras causas de muerte a nivel mundial. El desarrollo de ambas está condicionado por múltiples factores de riesgo, entre los que destaca el estado inflamatorio sistémico propio de pacientes obesos, que lleva a la progresión de la aterosclerosis. Profundizar en los mecanismos de esta relación resulta fundamental para el desarrollo de nuevas herramientas terapéuticas y profilácticas. Distintas investigaciones han demostrado la eficacia de la suplementación con ácidos grasos omega 3 en la disminución del estado inflamatorio, así como su acción sobre el metabolismo de los lípidos. Uno de los mecanismos que se han sugerido es que pueda actuar sobre la respuesta celular a la hipoxia que, en el tejido adiposo, podría ser la principal desencadenante de la inflamación y que determinará la evolución de los pacientes con cardiopatía isquémica o accidente cerebrovascular, que no suponen otra cosa que la interrupción del flujo sanguíneo a nivel coronario o cerebral. En este contexto, la presente revisión pretende determinar el estado de la investigación sobre el empleo de ácidos grasos omega 3 en el tratamiento y prevención de las principales enfermedades cardiovasculares por sus acciones frente a la hipoxia. A pesar de la heterogeneidad de los artículos revisados parece claro el efecto beneficioso de los ácidos grasos omega 3, aunque pocos parecen relacionarlo con su acción frente a la hipoxia. En estos últimos parece que el efecto estaría mediado por la angiogénesis y la actividad de VEGF y quizá podría estar implicada la regulación de HIF-1α. Si bien, parece clara la necesidad de una mayor investigación en este campo para detallar los mecanismos por los que actúan los omega 3 y la relación que podrían tener con la hipoxia.Ischemic heart disease and stroke are the leading causes of death worldwide. The development of both is conditioned by multiple risk factors, among which, the systemic inflammatory state characteristic of obese patients stands out, which leads to the progression of atherosclerosis. Studying the mechanisms of this relationship in depth is essential for the development of new therapeutic and prophylactic tools. Various investigations have shown the efficacy of omega 3 fatty acid supplementation in reducing the inflammatory state, as well as its action on lipid metabolism. One of the mechanisms that have been suggested is that it can act on the cellular response to hypoxia that, in adipose tissue, could be the main trigger for inflammation and that will determine the evolution of patients with ischemic heart disease or stroke, which only consist on the interruption of blood flow at coronary or cerebral level. In this context, this review aims to determine the state of the research on the use of omega 3 fatty acids in the treatment and prevention of the main cardiovascular diseases due to their actions against hypoxia. Despite the heterogeneity of the articles reviewed, the beneficial effect of omega 3 fatty acids seems clear, although few seem to relate these to their action against hypoxia. In the latter, it appears that the effect would be mediated by angiogenesis and VEGF activity, and perhaps, HIF-1α regulation might be involved. In any case, it seems clear the need for further research in this field to detail the mechanisms by which omega 3 act, and the relationship that they could have with hypoxia

Stress tensor fluctuations in de Sitter spacetime

The two-point function of the stress tensor operator of a quantum field in de Sitter spacetime is calculated for an arbitrary number of dimensions. We assume the field to be in the Bunch-Davies vacuum, and formulate our calculation in terms of de Sitter-invariant bitensors. Explicit results for free minimally coupled scalar fields with arbitrary mass are provided. We find long-range stress tensor correlations for sufficiently light fields (with mass m much smaller than the Hubble scale H), namely, the two-point function decays at large separations like an inverse power of the physical distance with an exponent proportional to m^2/H^2. In contrast, we show that for the massless case it decays at large separations like the fourth power of the physical distance. There is thus a discontinuity in the massless limit. As a byproduct of our work, we present a novel and simple geometric interpretation of de Sitter-invariant bitensors for pairs of points which cannot be connected by geodesics.Comment: 35 pages, 4 figure

Effect of Calcium Carbonate Residues from Cement Industries on the Phenolic Composition and Yield of Shiraz Grapes

Phenolic compounds are secondary metabolites synthesised in response to biotic or abiotic stress in plants.  This stress-induced increase in phenolic compound concentrations is generally activated by internal levels of abscisic acid (ABA). The exogenous application of ABA or calcium chloride on grapevines is also known to increase grape yield and alter the phenolic composition of grapes. Residues of cement industries such as calcium carbonates (CaCO3) are a safe environmental source of calcium that could be used to induce the synthesis of phenolic compounds and act as a yield promoter in grapes and other crops. Consequently, the objective of this study was to evaluate the effect of cement industries’ CaCO3 residues (CaCO3R) on the yield and concentration of phenolic compounds in Shiraz grapes. Thirteen phenolic compounds were identified and quantified by HPLC-DAD. Malvidin-3-O-glucoside was the major anthocyanin found inShiraz grapes, and its concentration increased by more than 200% in CaCO3R-treated vines. Similarly, the concentration of cinnamic acid, the main precursor of phenolic compounds, increased by more than 900%in grapes treated with CaCO3 residues at harvest time. Finally, catechin, epicatechin and procyanidin B1 and B2 increased significantly at harvest time in CaCO3R-treated grapes relative to the controls. In general, it was found that foliar application of CaCO3 residues from the cement industry at véraison induced an increase in yield, and in the concentration and composition of phenolic compounds in grapes

Antioxidant activity of alkaloids from Bocconia arborea. A study on six testing methods

El fraccionamiento de la actividad antioxidante dirigida por actividad, junto con el análisis químico, llevaron al aislamiento de tres alcaloides de benzofenantridina del extracto de metanol de la corteza de Bocconia arborea. La identificación se basó en métodos espectroscópicos. Se analizó la actividad antioxidante de los alcaloides aislados 6- acetonildihidroqueleritrina, queleritrina y dihidroqueleritrina en ensayos de tiocianato, la actividad de barrido de los radicales libres, el método de decoloración del b-caroteno y el ensayo de la desoxirribosa. Todos los alcaloides mostraron actividad antioxidante significativa en ácido linoleico y b-caroteno. Además de conceder protección frente a la desoxirribosa, la peroxidación liposómica y los lípidos microsomiales de la peroxidación, también presentaron efectos de barrido en los radicales de 1,1-difenil-2-picrilhidrazil.Antioxidative activity-guided fractionation together with chemical analysis led to the isolation of three benzophenanthridine alkaloids from methanol extract of the bark of Bocconia arborea. Identification was based on spectroscopic methods. The isolated alkaloids 6-acetonyldihydrochelerythrine, chelerythrine and dihydrochelerythrine were tested for antioxidative activity on thiocyanate assays, free radical scavenging activity, b-carotene bleaching method, and deoxyribose assay. All alkaloids exhibited significant antioxidant activities in linoleic acid and b-carotene. Although afforded protection against the damage of deoxyribose, liposome peroxidation and microsomial lipid from peroxidation, also exhibited scavenging effects on the 1,1-diphenyl-2-picrylhydrazyl radicals

Bounds on the dipole moments of the tau-neutrino via the process e+e−→ννˉγe^{+}e^{-}\rightarrow \nu \bar \nu \gamma in a 331 model

We obtain limits on the anomalous magnetic and electric dipole moments of the $\nu_{\tau}$ through the reaction $e^{+}e^{-}\rightarrow \nu \bar \nu \gamma$ and in the framework of a 331 model. We consider initial-state radiation, and neglect $W$ and photon exchange diagrams. The results are based on the data reported by the L3 Collaboration at LEP, and compare favorably with the limits obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C. arXiv admin note: substantial text overlap with arXiv:hep-ph/060527