1,175 research outputs found
Forecasting the effects of the Andaman Islands - Sumatra megathrust earthquakes (Dec. 2004 and Mar. 2005) on volcanoes in the surrounding area
The Andaman Islands - Sumatra earthquake (Mw = 9.3, Dec. 2004) and the subsequent Sumatra earthquake (Mw = 8.7, Mar. 2005) represent one of most energetic sequence of earthquakes ever recorded. Since both events occurred in a strongly
active volcanic region, their exceptionally strong stress perturbation gives the opportunity to understand the eff ects of stress perturbations on volcanic systems.
Here, we set the rules for a forward test of the causal relationship between stress
perturbation and subsequent volcanic eruptions, by means of the comparison of the spatio-temporal distribution of the eruptions which follow the earthquakes with the
co- and the post-seismic stress field due to the earthquakes. In practice, we forecast that the volcanic activity of the next 30 years will be significantly promoted by the stress perturbation; thus, we define the rules for an objective test of such
an hypothesis. Given the extremely high values of stress perturbation due to this sequence of earthquakes, the results of our test will definitively provide a reliable evaluation of the possible statistical impact of earthquake-eruption interaction on
long-term volcanic hazard assessments
Integration of stochastic models for long-term eruption forecasting into a Bayesian event tree scheme: a basis method to estimate the probability of volcanic unrest
Eruption forecasting refers, in general, to the
assessment of the occurrence probability of a given erup-
tive event, whereas volcanic hazards are normally associated
with the analysis of superficial and evident phenomena
that usually accompany eruptions (e.g., lava, pyroclastic
flows, tephra fall, lahars, etc.). Nevertheless, several hazards
of volcanic origin may occur in noneruptive phases dur-
ing unrest episodes. Among others, remarkable examples
are gas emissions, phreatic explosions, ground deforma-
tion, and seismic swarms. Many of such events may lead to
significant damages, and for this reason, the “risk” associ-
ated to unrest episodes could not be negligible with respect
to eruption-related phenomena. Our main objective in this
paper is to provide a quantitative framework to calculate
probabilities of volcanic unrest. The mathematical frame-
work proposed is based on the integration of stochastic mod-
els based on the analysis of eruption occurrence catalogs
into a Bayesian event tree scheme for eruption forecast-
ing and volcanic hazard assessment. Indeed, such models
are based on long-term eruption catalogs and in many
cases allow a more consistent analysis of long-term tem-
poral modulations of volcanic activity. The main result of
this approach is twofold: first, it allows to make inferences
about the probability of volcanic unrest; second, it allows
to project the results of stochastic modeling of the eruptive
history of a volcano toward the probabilistic assessment of
volcanic hazards. To illustrate the performance of the pro-
posed approach, we apply it to determine probabilities of
unrest at Miyakejima volcano, Japan
Bayesian event tree for eruption forecasting (BET_EF) at Vesuvius, Italy: a retrospective forward application to the 1631 eruption
Reliable forecasting of the next eruption at
Vesuvius is the main scientific factor in defining effective strategies to reduce volcanic risk in one of the most dangerous volcanic areas of the world. In this paper, we apply a recently developed probabilistic code for eruption forecasting to new and independent historical data related to the pre-eruptive phase of the 1631 eruption. The results obtained point out three main issues: (1) the importance of “cold” historical data (according to Guidoboni 2008) related to pre-eruptive phases for evaluating forecasting tools and possibly refining them; (2) the BET_EF code
implemented for Vesuvius would have forecasted the 1631 eruption satisfactorily, marking different stages of the pre-eruptive phase; (3) the code shows that pre-eruptive signals that significantly increase the probability of eruption were likely detected more than 2 months before the event
Primary radiotherapy in progressive optic nerve sheath meningiomas: a long-term follow-up study
Background/aims: To report the outcome of primary radiotherapy in patients with progressive optic nerve sheath meningioma (ONSM). Methods: The clinical records of all patients were reviewed in a retrospective, observational, multicentre study. Results: Thirty-four consecutive patients were included. Twenty-six women and eight men received conventional or stereotactic fractionated radiotherapy, and were followed for a median 58 (range 51–156) months. Fourteen eyes (41%) showed improved visual acuity of at least two lines on the Snellen chart. In 17 (50%) eyes, the vision stabilised, while deterioration was noted in three eyes (9%). The visual outcome was not associated with age at the time of radiotherapy (p=0.83), sex (p=0.43), visual acuity at the time of presentation (p=0.22) or type of radiotherapy (p=0.35). Optic disc swelling was associated with improved visual acuity (p<0.01) and 4/11 patients with optic atrophy also showed improvement. Long-term complications were dry eyes in five patients, cataracts in three, and mild radiation retinopathy in four. Conclusion: Primary radiotherapy for patients with ONSM is associated with long-term improvement of visual acuity and few adverse effects.Peerooz Saeed, Leo Blank, Dinesh Selva, John G. Wolbers, Peter J.C.M. Nowak, Ronald B. Geskus, Ezekiel Weis, Maarten P. Mourits, Jack Rootma
Densities and phase equilibria of hydrogen, propane and vegetable oil mixtures. Experimental data and thermodynamic modeling
Heterogeneous catalytic gas-liquid reactions are intensified when carried out in the homogenous fluid phase by means of a supercritical co-solvent. For instance, supercritical propane is used to enhance yield in the hydrogenation of vegetable oils. Besides phase equilibrium knowledge, volumetric information is also needed to elucidate kinetic mechanisms and design continuous supercritical reactors. In this work, we report new experimental PvT data of the reactive mixture H2+sunflower oil+propane using the isochoric method. In addition, the phase equilibria and PvT data are modeled with the GCA and RK-PR equations of state, respectively. The isochoric method not only provides PvT information under the reaction conditions, but also the reactive system compressibility, key variable to attain enhanced transport properties in the supercritical reactors.Fil: Hegel, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Cotabarren, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Brignole, Esteban Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Pereda, Selva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. University of KwaZulu-Natal; Sudáfric
Un ensayo de clasificación regional de la provincia de Tucumán
Fil: Santillán de Andrés, Selva E..
Universidad Nacional de TucumánFil: Ricci, Teodoro Ricardo.
Universidad Nacional de Tucumá
Bayesian Event Tree for Eruption Forecasting (BET_EF) at Vesuvius, Italy: a retrospective forward application to the 1631 eruption
Reliable forecasting of the next eruption at Vesuvius is the main scientific ingredient to define effective strategies to reduce volcanic risk in one of the most dangerous volcanic areas around the world. In this paper, we apply a recently developed probabilistic code for eruption forecasting to new and independent historical data related to the pre-eruptive phase of the 1631 eruption. The results obtained point out three main issues: 1) the importance of “cold” historical data (according to Guidoboni 2008) related to pre-eruptive phases for evaluating forecasting tools and possibly refining them; 2) the BET_EF code implemented for Vesuvius would have forecast the 1631 eruption satisfactorily, marking different stages of the pre-eruptive phase; 3) the code shows that pre-eruptive signals that significantly increase the probability of eruption were likely detected more than two months before the even
El equipo técnico en la orientación profesional y escolar
Más de cuarenta años de existencia científica poseen ya los más afamados servicios de orientación vocacional y profesional de Europa y América. La experiencia recogida a través de todo ese tiempo, mediante ensayos, confirmaciones y reformas, permiten que se pueda hablar de un equipo ideal para este tipo de servicios. Ante todo, convendría aclarar que la primitiva "orientación profesional" (la palabra profesional es típica en los países de idiomas latinos y vocacional "vocacional" en los de idioma inglés) ha agregado un "pariente" que adoptó todos sus rasgos, además de adjuntar algunos más para integrarse con toda propiedad en la función que desempeña.Departamento de Psicologí
Studies on Nymphaea pubescens willd. (Nymphaeaceae) - a plant drug of aquatic flora interest.
The present study was aimed at establishing scientific validation with supporting data of the aquatic plant Nymphaea pubescens Willd family Nymphaeaceae on its pharmacognosy, phytochemistry and pharmacological
activities.
The study for the first time designed to focus on the pharmacognostic standardization, systematic isolation of the phytoconstituents, identification by spectroscopic interpretation including 2D NMR studies and subjecting the same for physico-chemical analysis like Lipinski rule of five, pharmacodynamic and pharmacokinetic parameters, screening the plant extracts and the isolated compounds
for the target based antidiabetic activity in the type II diabetic animal model enzymatically and also at the receptor level, anti-cancer activity and In-vitro antioxidant
activity in order to establish and standardize the folklore claims.
The pharmacognostic standardization helps to differentiate between the species and adulterants or substitutes. The study revealed the macroscopic, microscopic identification, physico-chemical constants, powder and fluorescence
analytical datas that provides the standardizing protocol for Nymphaea pubescens.
Thoroughly investigated the literature, presence of macrocyclic flavonol Nympholide A and Nympholide B in Nymphaea lotus and Nuciferine in Nelumbo nucifera were isolated and reported. But so far no such compounds were isolated and scientifically proved from Nymphaea pubescens.
The phytochemical studies of the aquatic plant for the first time focused mainly on identification and isolation of two aliphatic compounds 10-oxoundecanoic acid and 14-oxopentadec-9-enoic acid, one aporphine based alkaloid Nuciferine and one flavonol Quercetin. The studies supported by TLC, HPTLC, UV, IR, 1H NMR, 13C NMR, 13C DEPT-135 NMR, HMBC 2D NMR, Mass spectroscopic and melting point data’s. In addition the isolated compounds are subjected for physico-chemical analysis by feeding the structure of the compound in the database ACD/ilabs. The physico-chemical studies revealed all the isolated compounds exhibits drug likeness
property.
The literature has thus so far documented no pharmacological and systematic study has been attempted to confirm the traditional practice of using Nymphaea pubescens in the treatment of diabetes and cancer.
The pharmacological studies of the root and rhizome showed that the ethanolic extract acts mechanistically by increasing the glycolytic enzymes, antiapoptotic
protein Bcl-2 expression and decreasing the gluconeogenic enzymes, proapoptotic protein expression in hepatic cells. The isolated compounds 10-oxoundecanoic acid, 14-oxopentadec-9-enoic acid and Nuciferine inhibit the Protein
tyrosine phosphatase 1B receptor involved in the insulin signaling deactivation pathway. The ethanolic extract from the root and rhizome of Nymphaea pubescens screened for the first time for antidiabetic activity in the type II diabetes induced animal models and the compounds 10-oxoundecanoic acid, 14-oxopentadec-9-enoic acid and Nuciferine was isolated from root and rhizome and molecularly docked for
the first time.
The ethyl acetate fraction from ethanolic flower extract of N.pubescens showed significant anticancer and anti-oxidant activity and the activities may be due to the presence of Quercetin which is isolated and reported for the first time.
We conclude that the aquatic plant Nymphaea pubescens is scientifically proved by isolating the compounds 10-oxoundecanoic acid, 14-oxopentadec-9-enoic acid, Nuciferine and Quercetin and validating by physico-chemical property analysis, chemotaxonomical analysis, molecular studies of the extracts for the antidiabetic activity, molecular docking for the isolated compounds with the receptor Protein
Tyrosine Phosphatase 1B, biological assay for active fraction in the DAL induced animal model and its free radical scavenging effect, since scientific validation is the hour of the day.
The aquatic plant Nymphaea pubescens also gives the chemotaxonomical significance due to the presence of aporphine based alkaloid Nuciferine and flavonol Quercetin to the Nymphaeaceae family.
In future, large scale isolation of 10-oxoundecanoic acid, 14-oxopentadec-9-enoic acid and Nuciferine and screening the isolated compounds for in-vivo antidiabetic activity including apoptotic studies, in-vivo assay for PTP1B, QSAR
studies may provide potent lead molecules for the treatment of type II diabetes mellitus
El equipo técnico en la orientación profesional y escolar
Más de cuarenta años de existencia científica poseen ya los más afamados servicios de orientación vocacional y profesional de Europa y América. La experiencia recogida a través de todo ese tiempo, mediante ensayos, confirmaciones y reformas, permiten que se pueda hablar de un equipo ideal para este tipo de servicios. Ante todo, convendría aclarar que la primitiva "orientación profesional" (la palabra profesional es típica en los países de idiomas latinos y vocacional "vocacional" en los de idioma inglés) ha agregado un "pariente" que adoptó todos sus rasgos, además de adjuntar algunos más para integrarse con toda propiedad en la función que desempeña.Departamento de Psicologí
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