Cartografía geoquímica multielemental en sedimentos de corriente en un contexto de arco isla volcánico. Aplicación al análisis de potencialidad metalogénica en un area de la República Dominicana

Este estudio presenta los principales resultados y conclusiones de la exploración y cartografía geoquímica multielemental llevada a cabo, a partir de muestras de sedimentos de arroyo, en el sector de Bonao-Constanza de la Cordillera Central de la República Dominicana. En el área estudiada, de 3.800 km2, fueron recogidas 684 muestras, con una densidad de muestreo de 1 muestra / 5 km2, en las que se analizaron 48 elementos químicos por técnicas de ICPAES y Activación Neutrónica. Esta zona, situada en el ámbito del arco isla de borde de la placa caribeña, contiene importantes mineralizaciones de carácter epitermal y volcanosedimentario y posee un gran potencial de nuevas mineralizaciones. Dada la complejidad geológica y los fenómenos superimpuestos de alteración hidrotermal, la geoquímica multielemental permite, a través del análisis de las pautas de distribución espacial de los elementos y de las asociaciones geoquímicas, una definición más razonada de áreas anómalas, su valoración, y un conocimiento de su posible significado en relación con el contexto petrogenético, geológico y geoquímico en el que se hallan. La información geoquímica de los materiales superficiales, permite, de acuerdo con las tendencias generales de la cartografía geoquímica, extraer conclusiones que son de aplicación e interés para el conocimiento geológico y ambiental del territorio, además de para la exploración minera.The main results and conclusions of the multielemental geochemical mapping on stream sediments carried out in the Bonao-Constanza area, Cordillera Central, Dominican Republic are presented in this paper. The studied area covers 3800 km2 . The sampling density applied was 1 sample / 5 km2. A total of 684 samples were taken and 48 elements were analysed by Neutron Activation and ICPAES techniques. The area, located in the island arc of the Caribbean plate, contains important epithermal and volcanosedimentary mineralizations and has a huge potential for blind deposits. Due to the complex geology and the superimposed hydrothermal alterations, the multielemental geochemistry allows, through the analysis of patterns of spatial distribution of the elements and their geochemical associations, a better definition of anomalous zones and their assessment and meaning in relationship with their petrogenetic, geological and geochemical context. The geochemical datasets of the superficial materials allow, according with the general trends of the geochemical exploration and mapping, to get applicable and interesting conclusions for the geological, environmental and mineral exploration knowledge

Cartografía geoquímica multielemental en sedimentos de corriente en un contexto de arco isla volcánico. Aplicación al análisis de potencialidad metalogénica en un area de la República Dominicana

The main results and conclusions of the multielemental geochemical mapping on stream sediments carried out in the Bonao-Constanza area, Cordillera Central, Dominican Republic are presented in this paper. The studied area covers 3800 km2 . The sampling density applied was 1 sample / 5 km2. A total of 684 samples were taken and 48 elements were analysed by Neutron Activation and ICPAES techniques. The area, located in the island arc of the Caribbean plate, contains important epithermal and volcanosedimentary mineralizations and has a huge potential for blind deposits. Due to the complex geology and the superimposed hydrothermal alterations, the multielemental geochemistry allows, through the analysis of patterns of spatial distribution of the elements and their geochemical associations, a better definition of anomalous zones and their assessment and meaning in relationship with their petrogenetic, geological and geochemical context. The geochemical datasets of the superficial materials allow, according with the general trends of the geochemical exploration and mapping, to get applicable and interesting conclusions for the geological, environmental and mineral exploration knowledge

Existence of positive solutions for a parameter fractional pp-Laplacian problem with semipositone nonlinearity

In this paper we prove the existence of at least one positive solution for the nonlocal semipositone problem $$\displaystyle \left\{\begin{array}{rcll} (-\Delta)_p^s(u) &=& \lambda f(u) \qquad & \text{in} \ \ \Omega \\u &=& 0 & \text{in} \ \ \mathbb{R}^N -\Omega , \end{array}\right.$$ whenever $\lambda >0$ is a sufficiently small parameter. Here $\Omega \subseteq \mathbb{R}^N$ a bounded domain with $C^{1,1}$ boundary, $2\leqslant p <N$, $s\in (0,1)$ and $f$ superlineal and subcritical. We prove that if $\lambda>0$ is chosen sufficiently small the associated Energy Functional to the problem has a mountain pass structure and, therefore, it has a critical point $u_\lambda$, which is a weak solution. After that we manage to prove that this solution is positive by using new regularity results up to the boundary and a Hopf's Lemma

Role of plastid transglutaminase in LHCII polyamination and thylakoid electron and proton flow

Transglutaminases function as biological glues in animal cells, plant cells and microbes. In energy producing organelles such as chloroplasts the presence of transglutaminases was recently confirmed. Furthermore, a plastidial transglutaminase has been cloned from maize and the first plants overexpressing tgz are available (Nicotiana tabacum TGZ OE). Our hypothesis is that the overexpression of plastidal transglutaminase will alter photosynthesis via increased polyamination of the antenna of photosystem II. We have used standard analytical tools to separate the antenna from photosystem II in wild type and modified plants, 6 specific antibodies against LHCbs to confirm their presence and sensitive HPLC method to quantify the polyamination level of these proteins. We report that bound spermidine and spermine were significantly increased (∼80%) in overexpressors. Moreover, we used recent advances in in vivo probing to study simultaneously the proton and electron circuit of thylakoids. Under physiological conditions overexpressors show a 3-fold higher sensitivity of the antenna down regulation loop (qE) to the elicitor (luminal protons) which is estimated as the ΔpH component of thylakoidal proton motive force. In addition, photosystem (hyper-PSIIα) with an exceptionally high antenna (large absorption cross section), accumulate in transglutaminase over expressers doubling the rate constant of light energy utilization (Kα) and promoting thylakoid membrane stacking. Polyamination of antenna proteins is a previously unrecognized mechanism for the modulation of the size (antenna absorption cross section) and sensitivity of photosystem II to down regulation. Future research will reveal which peptides and which residues of the antenna are responsible for such effects

Vascular Complications of Pancreatitis: Role of Interventional Therapy

Major vascular complications related to pancreatitis can cause life-threatening hemorrhage and have to be dealt with as an emergency, utilizing a multidisciplinary approach of angiography, endoscopy or surgery. These may occur secondary to direct vascular injuries, which result in the formation of splanchnic pseudoaneurysms, gastrointestinal etiologies such as peptic ulcer disease and gastroesophageal varices, and post-operative bleeding related to pancreatic surgery. In this review article, we discuss the pathophysiologic mechanisms, diagnostic modalities, and treatment of pancreatic vascular complications, with a focus on the role of minimally-invasive interventional therapies such as angioembolization, endovascular stenting, and ultrasound-guided percutaneous thrombin injection in their management

The in-plane electrodynamics of the superconductivity in Bi2Sr2CaCu2O8+d: energy scales and spectral weight distribution

The in-plane infrared and visible (3 meV-3 eV) reflectivity of Bi2Sr2CaCu2O8+d (Bi-2212) thin films is measured between 300 K and 10 K for different doping levels with unprecedented accuracy. The optical conductivity is derived through an accurate fitting procedure. We study the transfer of spectral weight from finite energy into the superfluid as the system becomes superconducting. In the over-doped regime, the superfluid develops at the expense of states lying below 60 meV, a conventional energy of the order of a few times the superconducting gap. In the underdoped regime, spectral weight is removed from up to 2 eV, far beyond any conventional scale. The intraband spectral weight change between the normal and superconducting state, if analyzed in terms of a change of kinetic energy is ~1 meV. Compared to the condensation energy, this figure addresses the issue of a kinetic energy driven mechanism.Comment: 13 pages with 9 figures include

Antioxidant activity and cardioprotective effect of a nonalcoholic extract of Vaccinium meridionale Swartz during ischemia-reperfusion in rats

Our objective was to assess the antioxidant properties and the effects against the reperfusion injury of a nonalcoholic extract obtained by fermentation from the Colombian blueberry, mortino ( Vaccinium meridionale Swartz, Ericaceae). Antioxidant properties were assessed by in vitro systems. To examine the postischemic myocardial function, isolated rat hearts were treated 10 min before ischemia and during the first 10 min of reperfusion with the extract. To analyze the participation of nitric oxide (NO), other experiments were performed in the presence of nitric oxide synthase (NOS) inhibition with NG-nitro-L-arginine methyl ester (L-NAME). In cardiac tissue thiobarbituric acid reactive substances (TBARS) concentration, reduced glutathione (GSH) content, endothelial NOS (eNOS), and Akt expression were also measured. The blueberry extract showed higher total phenols and anthocyanins contents, scavenging activity of superoxide radical and systolic and diastolic function was improved, TBARS diminished, GSH was partially preserved, and both NOS and Akt expression increased in hearts treated with the extract. These beneficial effects were lost when eNOS was inhibited. In resume, these data show that the increase of eNOS expression via Akt and the scavenging activity contribute to the cardioprotection afforded by acute treatment with Colombian blueberry extract against ischemia and reperfusion injury.Fil: Lopera, Yasmin E.. Universidad Nacional de Colombia; ColombiaFil: Fantinelli, Juliana Catalina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico la Plata. Centro de Investigaciones Cardiovasculares "dr. Horacio Eugenio Cingolani"; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: González Arbeláez, Luisa Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico la Plata. Centro de Investigaciones Cardiovasculares "dr. Horacio Eugenio Cingolani"; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: Rojano, Benjamín. Universidad Nacional de Colombia; ColombiaFil: Ríos, José Luis. Universidad de Valencia; EspañaFil: Schinella, Guillermo. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Mosca, Susana Maria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico la Plata. Centro de Investigaciones Cardiovasculares "dr. Horacio Eugenio Cingolani"; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentin