Thick target pixe analysis

Bibliography: p. 211-221.The evaluation of the physical parameters governing the X-ray yield production in thick targets by charged particles was investigated and matrix correction factors (MCF) were calculated for a wide variety of materials including values for all pure non-gaseous elements or their compounds for the Kα and Lα X-ray lines. These factors were calculated for 1, 2, 3 and 4 MeV proton bombarding energies. A new methodology named 'common matrix type' (CMT) was developed for the determination of trace element concentrations in carbon-rich materials, such as most biological materials, with unknown matrix composition. A universal set of matrix correction factors (MCF) values for these materials was established for trace elements with Z ≥ 19 and irradiations with proton energies in the range of 1 to 4 MeV. A similar methodology was developed for silicon-rich and calcium-rich materials where the main components, Al, Si and Ca do not vary appreciably in their concentrations. CMT methodologies were applied successfully for the determination of trace elemental concentrations in a wide variety of thick target materials, which included archaeological cultural materials, biological tissues and geological ores. The technique of correspondence analysis was used for the statistical analysis of the extended data matrix generated in most of the applications. This technique of interpretation of multielemental data proved to be a valuable tool. Two modes of PIXE application, macro-mode and micro-mode, were evaluated at different ion bombarding energies ranging from 1 to 85 MeV. Experimental X-ray production cross sections at 66 and 85 MeV were evaluated and found to correlate well with theory based on the plane wave Born approximation (PWBA) for the Kα and Kβ lines. It was found that the irradiation of intermediate thickness samples of geological ores by energetic protons (66 MeV) is a suitable technique for the determination of small traces of rare earth metals with detection limits for analysis expected to be below the μg.g-1 range. The fact that energetic protons can be used means that no need for matrix correction is necessary. Micro-PIXE with low energy protons was found suitable for the determination of small traces of metals in human kidney stones and for the study of interrelationships between trace element concentrations with time of stone formation, in stones excreted from a single patient

Myrosmodes nervosa (Orchidaceae, Cranichidinae, subgenus Myrosmodes): nueva combinación de Myrosmodes para Chile

De acuerdo a datos macromorfológicos y de hábitat se transfiere Altensteinia nervosa Kraenzl. al género Myrosmodes. Se describela especie y se establece el tipo.De acuerdo a datos macromorfológicos y de hábitat se transfiere Altensteinia nervosa Kraenzl. al género Myrosmodes. Se describela especie y se establece el tipo

Letter from the editor

Dear readers. The Earth Sciences Research Journal has been recently flooded with dozens of good papers expecting to be published. Thanks to you, readers, reviewers, authors for your trust. We are continuously working to improve our editorial processes. The trend topics of those papers go from gas and petroleum exploitation, land use, geological hazards, to sustainable development, environmental protection and optimization of operation techniques. Without forgetting the basic research. All those subjects are welcome in Earth Sciences Research Journal. Proudly, we remark our journal, your journal, as the natural stage for the debate between economic development and sustainable development. There is no a better referee for this discussion than education entities. If your manuscript put lights on this important subjects, do not hesitate to submit it. Is this not a minor topic! Nowadays, every political decision, every policy designed, every industrial and human activity are seen through the lens of the Environmental Awareness. We can not quit on this responsibility. As an example of how important those topics are, during the coming days, US President Barack Obama is going to enact a law expanding the protection areas in Hawaii in close four times the current size. It means longlines fishing operators will not be permitted in the 582581 square miles; neither the seabed mining in a region with rich deposits of manganese, nickel, zinc, cobalt, and titanium. Similar decisions have been taken in Chile and Costa Rica, this last one with a 26% of its land territory protected as a natural park. Just talking about some cases in this side of the world, where we are more familiar with. The next meeting of Geological Society of America, taking place in Denver, on September, will hand on this same topics. Are the extracting and exploitation of resource prohibitions the solution to environmentalism? Welcome all your papers cracking this nut

Letter from editor

During the outgoing year, successful events took place, as Latin American and Caribbean Seismological Commission Assembly, on July 23, 24, 25, in Bogotá, Colombia. In that academic event, the relevant results associated with the seismotectonic behavior of the Latin America and Caribbean region were addressed, as well as the implications of active exploration of the tectonic conditions, the socio-economic impacts of exploration and extraction of economic resources, and the implementation of non-conventional techniques for exploring and mining that can contribute to sustainable development. Another event was the Shale Colombia 2014, unconventional oil and gas development congress, aimed to determine the next steps towards the commercialization of unconventional oil and gas development for the country. The event hosted case studies from some of the pioneers in Colombian development, using the latest reservoir data fiscal updates and global scale technology case studies, to evaluate real potential Colombia holds for unconventional development. In the outlook of 2015, one of the main events is the 26th International Union of Geodesy and Geophysics General Assembly, to be realized between June 22 and July 2, in Prague, Czech Republic. You are on time to participate in this event yet. In Colombia will take place the XV Colombian Congress of Geology on 31 August to 5 September. This event is a bi-annual meeting gathering scientists, academicians, and researchers from the region, with an extensive participation of international guests. The Congress wants to provide a scenery to discuss the perspectives of mineral resources, new exploration techniques related to energy supply, proposals for optimized management of mining and mineral resources, between other topics.Finally, we want to introduce you the manuscripts selected for this edition. There is a broad range of information about seismology with four papers coming from different countries. The first one is an analysis of the elastic structure beneath Australia shown by means of S-velocity maps and determined by the regionalization and inversion of Rayleigh wave dispersion. The obtained S-velocity models suggest the existence of lateral and vertical heterogeneity in the structure.From Turkey, the second manuscript presents a site response analysis and estimation of S-wave velocity depending on acceleration data. The other two articles in seismology for this edition are based on improving accuracy and reliability of the first arrival times through Cross Correlation Technique, and in the characterization of seismic events using only one seismological station. In other knowledge field, it is presented a mineralization potential study of the intrusive bodies in Valis, northwest of Iran. A very graphical manuscript coming from the Gaza strip shows a study in sand dunes, from morphology, textural characteristics, and associated environmental impacts. From Morocco, a study aimed to evaluate geostatistical methods for delimitation of anomalies detected in the phosphatic series of Sidi Chenane found that the exponential model is the best one to represent the spatial variability of their geoelectric data; models of the geology were successfully obtained from geostatistical method, which help mapping the phosphate deposit inclusions and the estimations of phosphate reserves were improved and better constrained. In geotechnics, three important works are displayed. One is about the experimental triaxial tests developed to estimate undrained critical shear strength under monolithic loadings; the second one reads about classification of caving depth by feature extraction in cutting images, and the other is a simulation using artificial neural network and adaptative neuro-fuzzy system of compression ratio in a municipal solid waste. Last two works talk about GIS and Kriging techniques applied to map a spatial distribution of sediments pollution in the Khajeh Kory river and an assessment of the land ecological security for Yancheng city, in China. We hope you may find interesting information in our ESRJ.  Carlos Alberto Vargas Earth Sciences Research Journal Editor in Chie

Letter from the editor

Dear readers. The Earth Sciences Research Journal has been recently flooded with dozens of good papers expecting to be published. Thanks to you, readers, reviewers, authors for your trust. We are continuously working to improve our editorial processes. The trend topics of those papers go from gas and petroleum exploitation, land use, geological hazards, to sustainable development, environmental protection and optimization of operation techniques. Without forgetting the basic research. All those subjects are welcome in Earth Sciences Research Journal. Proudly, we remark our journal, your journal, as the natural stage for the debate between economic development and sustainable development. There is no a better referee for this discussion than education entities. If your manuscript put lights on this important subjects, do not hesitate to submit it. Is this not a minor topic! Nowadays, every political decision, every policy designed, every industrial and human activity are seen through the lens of the Environmental Awareness. We can not quit on this responsibility. As an example of how important those topics are, during the coming days, US President Barack Obama is going to enact a law expanding the protection areas in Hawaii in close four times the current size. It means longlines fishing operators will not be permitted in the 582581 square miles; neither the seabed mining in a region with rich deposits of manganese, nickel, zinc, cobalt, and titanium. Similar decisions have been taken in Chile and Costa Rica, this last one with a 26% of its land territory protected as a natural park. Just talking about some cases in this side of the world, where we are more familiar with. The next meeting of Geological Society of America, taking place in Denver, on September, will hand on this same topics. Are the extracting and exploitation of resource prohibitions the solution to environmentalism? Welcome all your papers cracking this nut

In vivo Neutralization of Pro-inflammatory Cytokines During Secondary Streptococcus pneumoniae Infection Post Influenza A Virus Infection

An overt pro-inflammatory immune response is a key factor contributing to lethal pneumococcal infection in an influenza pre-infected host and represents a potential target for therapeutic intervention. However, there is a paucity of knowledge about the level of contribution of individual cytokines. Based on the predictions of our previous mathematical modeling approach, the potential benefit of IFN-γ- and/or IL-6-specific antibody-mediated cytokine neutralization was explored in C57BL/6 mice infected with the influenza A/PR/8/34 strain, which were subsequently infected with the Streptococcus pneumoniae strain TIGR4 on day 7 post influenza. While single IL-6 neutralization had no effect on respiratory bacterial clearance, single IFN-γ neutralization enhanced local bacterial clearance in the lungs. Concomitant neutralization of IFN-γ and IL-6 significantly reduced the degree of pneumonia as well as bacteremia compared to the control group, indicating a positive effect for the host during secondary bacterial infection. The results of our model-driven experimental study reveal that the predicted therapeutic value of IFN-γ and IL-6 neutralization in secondary pneumococcal infection following influenza infection is tightly dependent on the experimental protocol while at the same time paving the way toward the development of effective immune therapies

A Fresh Catch of Massive Binaries in the Cygnus OB2 Association

Massive binary stars may constitute a substantial fraction of progenitors to supernovae and gamma-ray bursts, and the distribution of their orbital characteristics holds clues to the formation process of massive stars. As a contribution to securing statistics on OB-type binaries, we report the discovery and orbital parameters for five new systems as part of the Cygnus OB2 Radial Velocity Survey. Four of the new systems (MT070, MT174, MT267, and MT734 (a.k.a. VI Cygni #11) are single-lined spectroscopic binaries while one (MT103) is a double-lined system (B1V+B2V). MT070 is noteworthy as the longest period system yet measured in Cyg OB2, with P=6.2 yr. The other four systems have periods ranging between 4 and 73 days. MT174 is noteworthy for having a probable mass ratio q<0.1, making it a candidate progenitor to a low-mass X-ray binary. These measurements bring the total number of massive binaries in Cyg OB2 to 25, the most currently known in any single cluster or association.Comment: Accepted for publication in the Astrophysical Journa