Plan de manejo ambiental para mitigar los impactos generados por explotacion minera en el municipio de Nechí en el Bajo Cauca - Región de La Mojana

Trabajo de InvestigaciónEsta investigación propone un Plan de Manejo Ambiental enfocado a la explotación minera, especialmente dirigido al municipio de Nechí – Antioquia (Colombia), lo anterior debido a los problemas y fuertes impactos ambientales y sociales, que se han visto con el pasar del tiempo debido al mal manejo de los procesos necesarios para tal fin.INTRODUCCIÓN 1. ANTECEDENTES 2. PLANTEAMIENTO Y FORMULACION DEL PROBLEMA 3. OBJETIVOS 4. MARCO DE REFERECIA TEORICO 5. MARCO DE REFERECIA CONCEPTUAL 6. CARACTERIZACION DEL TERRITORIO 7. ESTUDIO DE IMPACTO AMBIENTAL E IDENTIFICACION DE PROBLEMAS GENERADOS POR LA EXPLOTACION MINERA 8. DISEÑO PLAN DE MANEJO AMBIENTAL 9. CONCLUSIONES Y RECOMENDACIONES 10. BIBLIOGRAFIAPregradoIngeniero Civi

Synthesis of 2-methyl- and 2-methylenecyclobutane amino acids

An efficient and easy formal [2+2] cycloaddition (Michael-Dieckmann-type reaction) on methyl 2-acetamidoacrylate with ketene diethyl acetal gave the cyclobutane core. Two kinds of 2-substituted cyclobutane amino acids have been obtained from this compound by means of stereocontrolled interconversion of functional groups: 1-amino-2-methylcyclobutane-1-carboxylic acids (2,4-methanovalines) and 1-amino-2-methylenecyclobutane-1-carboxylic acid. The latter amino acid can be regarded as a restricted -methyl-- vinylglycine. © 2005 Elsevier Ltd. All rights reserved

Photoionization in the time and frequency domain

Ultrafast processes in matter, such as the electron emission following light absorption, can now be studied using ultrashort light pulses of attosecond duration ($10^{-18}$s) in the extreme ultraviolet spectral range. The lack of spectral resolution due to the use of short light pulses may raise serious issues in the interpretation of the experimental results and the comparison with detailed theoretical calculations. Here, we determine photoionization time delays in neon atoms over a 40 eV energy range with an interferometric technique combining high temporal and spectral resolution. We spectrally disentangle direct ionization from ionization with shake up, where a second electron is left in an excited state, thus obtaining excellent agreement with theoretical calculations and thereby solving a puzzle raised by seven-year-old measurements. Our experimental approach does not have conceptual limits, allowing us to foresee, with the help of upcoming laser technology, ultra-high resolution time-frequency studies from the visible to the x-ray range.Comment: 5 pages, 4 figure

Search for neutrinos from transient sources with the ANTARES telescope and optical follow-up observations

The ANTARES telescope has the opportunity to detect transient neutrino sources, such as gamma-ray bursts, core-collapse supernovae, flares of active nuclei... To enhance the sensitivity to these sources, we have developed a new detection method based on the optical follow-up of "golden" neutrino events such as neutrino doublets coincident in time and space or single neutrinos of very high energy. The ANTARES Collaboration has therefore implemented a very fast on-line reconstruction with a good angular resolution. These characteristics allow to trigger an optical telescope network; since February 2009. ANTARES is sending alert trigger one or two times per month to the two 25 cm robotic telescope of TAROT. This follow-up of such special events would not only give access to the nature of the sources but also improves the sensitivity for transient neutrino sources.Comment: 3 pages, 3 figures, Proceedings of the 31st ICRC, Lodz, Polan, July 200

Membrane binding and insertion of the predicted transmembrane domain of human scramblase 1

AbstractHuman phospholipid scramblase 1 (SCR) was originally described as an intrinsic membrane protein catalyzing transbilayer phospholipid transfer in the absence of ATP. More recently, a role as a nuclear transcription factor has been proposed for SCR, either in addition or alternatively to its capacity to facilitate phospholipid flip-flop. Uncertainties exist as well from the structural point of view. A predicted α-helix (aa residues 288–306) located near the C-terminus has been alternatively proposed as a transmembrane domain, or as a protein core structural element. This paper explores the possibilities of the above helical segment as a transmembrane domain. To this aim two peptides were synthesized, one corresponding to the 19 α-helical residues, and one containing both the helix and the subsequent 12-residues constituting the C-end of the protein. The interaction of these peptides with lipid monolayers and bilayers was tested with Langmuir balance surface pressure measurements, proteoliposome reconstitution and analysis, differential scanning calorimetry, tests of bilayer permeability, and fluorescence confocal microscopy. Bilayers of 28 different lipid compositions were examined in which lipid electric charge, bilayer fluidity and lateral heterogeneity (domain formation) were varied. All the results concur in supporting the idea that the 288–306 peptide of SCR becomes membrane inserted in the presence of lipid bilayers. Thus, the data are in agreement with the possibility of SCR as an integral membrane protein, without rejecting alternative cell locations

Accurate quantification of selenoproteins in human plasma/serum by isotope dilution ICP-MS : focus on selenoprotein P

Acknowledgements The research leading to these results was funded by the EMRP Joint Research Project “Metrology for metalloproteins” (HLT-05 2012). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.Peer reviewedPostprin

Evaluating the Neolithic expansion at both shores of the Mediterranean Sea

During the Neolithic, human populations underwent cultural and technological developments that led to an agricultural revolution. Although the population genetics and evolution of European Neolithic populations have been extensively studied, little is known regarding the Neolithic expansion in North Africa with respect to Europe. One could expect that the different environmental and geological conditions at both shores of the Mediterranean Sea could have led to contrasting expansions. In order to test this hypothesis, we compared the Neolithic expansion in Europe and North Africa accounting for possible migration between them through the Strait of Gibraltar. We analyzed the entire X chromosome of 580 individuals from 20 populations spatially distributed along the North of Africa and Europe. Next, we applied approximate Bayesian computation based on extensive spatially explicit computer simulations to select among alternative scenarios of migration through the Strait of Gibraltar and to estimate population genetics parameters in both expansions. Our results suggest that, despite being more technologically advanced, Neolithic populations did not expand faster than Paleolithic populations, which could be interpreted as a consequence of a more sedentary lifestyle. We detected reciprocal Neolithic migration between the Iberian Peninsula and North Africa through the Strait of Gibraltar. Counterintuitively, we found that the studied Neolithic expansions presented similar levels of carrying capacity and migration, and occurred at comparable speeds, suggesting a similar demic process of substitution of hunter–gatherer populations. Altogether, the Neolithic expansion through both Mediterranean shores was not so different, perhaps because these populations shared similar technical abilities and lifestyle patterns.Fundação para a Ciência e a Tecnologia | Ref. POCI-01-0145-FEDER-007274Fundação para a Ciência e a Tecnologia | Ref. SFRH/BD/97200/2013Fundação para a Ciência e a Tecnologia | Ref. IF/01262/2014Fundação para a Ciência e a Tecnologia | Ref. IF/00955/2014Ministerio de Economía y Competitividad | Ref. RYC-2015-18241Ministerio de Economía y Competitividad | Ref. CGL2013-44351-