Situación actual del secado artificial de madera proveniente del bosque nativo

Vásquez, M. Facultad de Ciencias Forestales. Universidad de Talca. Casilla 747, Talca. Chile. Hernández, G. Jefe de Proyectos. División Industrias. Instituto Forestal, Casilla 109C, Concepción. Chile.La reciente promulgación de la Ley Corta de Bosque Nativo ha motivado a varias instituciones a poner especial atención en la importancia que éste puede poseer desde el punto de vista productivo, ambiental y social. El manejo del bosque nativo debería generar una considerable actividad en torno al recurso, habiéndose estimado un área productiva de 5,13 millones de hectáreas dentro de un total de 13,4 millones de hectáreas actualmente existentes. El primer paso hacia la agregación de valor de la madera aserrada proveniente del bosque nativo se centra en el correcto secado, que por provenir de árboles de renovales, bosques jóvenes, pueden incorporar más variables al desafío técnico de secar en un tiempo razonable con una calidad aceptable. La tecnología puede estar disponible, sin embargo la falta de estudio en forma sistemática ha dificultado proporcionar el conocimiento sobre su comportamiento frente al secado y las causas que originan su desclasificación. El presente estudio es una revisión bibliográfica que recopila la información sobre programas de secado, tiempo de secado y defectos del proceso, publicadas en universidades, centros de investigación, organismos estatales y entrevistas con especialistas del área. Los resultados que pretende mostrar son las actuales prácticas del secado en especies nativas como coigue (Nothofagus dombeyi), coigue de Magallanes (Nothofagus betuliodes), raulí (Nothofagus alpina), roble (Nothofagus oblicua), hualo (Nothofagus glauca), lenga (Nothofagus pumilio), tepa (Laurelia philippiana) y canelo (Drymis winteri) y señalar que es necesario seguir ampliando el conocimiento hacia otras especies, como por ejemplo el olivillo (Aextoxicom punctatum) de la región del Maule

Radio y cultura: Una propuesta de radio ciudadana en Internet

This article is the result of research project to qualify for a Master's degree "La Peña Cultural: model citizen Internet radio" carried out during 2013 and 2014 for Universidad de Medellin. It explored the Internet radio as a platform with multimedia tools that could strengthen the formation of reflective citizenship through content of cultural promotion. Similarly, it identifies, from a tracking station in Colombia, how these tools -social networks, podcasts, chats, video channels and new ways to communicate- allow the active participation of citizens in their production. Rescuing the use of technologies that facilitate communication, such as Internet radio, to recognize and retrieve the value of their own cultural promotion of a state in order to form a reflective citizenship, it is the approach that was made from the ethnographic and applied research and is now presented in this article. It is the way in which citizens could converge in a medium to produce content that will strengthen their cultural identity or, if you will, their vision of the nation. It is a commitment to establish an alternative to the traditional models, a guide to the community interested in promoting a reflexive citizen of cultural heritage

Structural models of the different trimers present in the core of phycobilisomes from <i>Gracilaria chilensis</i> based on crystal structures and sequences

Phycobilisomes (PBS) are accessory light harvesting protein complexes that directionally transfer energy towards photosystems. Phycobilisomes are organized in a central core and rods radiating from it. Components of phycobilisomes in Gracilaria chilensis (Gch) are Phycobiliproteins (PBPs), Phycoerythrin (PE), and Phycocyanin (PC) in the rods, while Allophycocyanin (APC) is found in the core, and linker proteins (L). The function of such complexes depends on the structure of each component and their interaction. The core of PBS from cyanobacteria is mainly composed by cylinders of trimers of α and β subunits forming heterodimers of Allophycocyanin, and other components of the core including subunits αII and β18. As for the linkers, Linker core (LC) and Linker core membrane (LCM) are essential for the final emission towards photoreaction centers. Since we have previously focused our studies on the rods of the PBS, in the present article we investigated the components of the core in the phycobilisome from the eukaryotic algae, Gracilaria chilensis and their organization into trimers. Transmission electron microscopy provided the information for a three cylinders core, while the three dimensional structure of Allophycocyanin purified from Gch was determined by X-ray diffraction method and the biological unit was determined as a trimer by size exclusion chromatography. The protein sequences of all the components of the core were obtained by sequencing the corresponding genes and their expression confirmed by transcriptomic analysis. These subunits have seldom been reported in red algae, but not in Gracilaria chilensis. The subunits not present in the crystallographic structure were modeled to build the different composition of trimers. This article proposes structural models for the different types of trimers present in the core of phycobilisomes of Gch as a first step towards the final model for energy transfer in this system

Anthropologists Respond to The Lancet EAT Commission

The Lancet Commissions are widely known as aspirational pieces, providing the mechanisms for consortia and networks of researchers to organize, collate, interrogate and publish around a range of subjects. Although the Commissions are predominantly led by biomedical scientists and cognate public health professionals, many address social science questions and involve social science expertise. Medical anthropologist David Napier was lead author of the Lancet Commission on Culture and Health (2014), for example, and all commissions on global health (https://www.thelancet.com/global-health/commissions) address questions of social structure, everyday life, the social determinants of health, and global inequalities.The Nutrire CoLab: Diana Burnett; Megan A. Carney; Lauren Carruth; Sarah Chard; Maggie Dickinson: Diana Burnett, Megan A. Carney, Lauren Carruth, Sarah Chard, Maggie Dickinson, Alyshia Gálvez, Hanna Garth, Jessica Hardin, Adele Hite, Heather Howard, Lenore Manderson, Emily Mendenhall, Abril Saldaña-Tejeda, Dana Simmons, Natali Valdez, Emily Vasquez, Megan Warin, Emily Yates-Doer

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

Search for Anomalous Couplings in the Higgs Sector at LEP

Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

Neutral-Current Four-Fermion Production in e+e- Interactions at LEP

Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of data collected with the L3 detector at LEP at centre-of-mass energies root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and llvv, where l denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e+e- -> Zgamma* -> ffff process is studied and its total cross section at the average centre-of-mass energy 196.6GeV is found to be 0.29 +/- 0.05 +/- 0.03 pb, where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass spectra of the qqll final states are analysed to search for the possible production of a new neutral heavy particle, for which no evidence is found

Measurement of Exclusive rho+rho- Production in Mid-Virtuality Two-Photon Interactions and Study of the gamma gamma* -> rho rho Process at LEP

Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 < Q^2 <0.85GeV^2 and 1.1GeV < W_gg < 3GeV. These results, together with previous L3 measurements of rho0 rho0 and rho+ rho- production, allow a study of the gamma gamma* -> rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2