Jonathan A Guzmán

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The utilization of lignin from Pinus radiata black liquor, as a copolymer in ligninphenol-formaldehyde resin binders was studied. Methylolation, demethylation and ultrafiltration separation of high molecular-weight fractions were carried out in order to increase lignin reactivity. The different modified lignins were tested in preparation of(More)
AIMS The species identification and antimicrobial resistance profiles were determined for enterococci isolated from Southern California surface and ocean waters. METHODS AND RESULTS Species identification was determined for 1413 presumptive Enterococcus isolates from urban runoff, bay, ocean and sewage water samples. The most frequently isolated species(More)
Environmental heterogeneity mostly dominated by differing light regimes affects the expression of phenotypic plasticity, which is important for plant growth and survival, especially in the forest understory. The knowledge about these responses to this heterogeneity is a key factor for forest restoration initiatives. In this study, we determine several(More)
We have recently redesigned the first crystal mount of our cryogenically cooled monochromator to reduce its sensitivity to pressure fluctuations in the cryogenic lines feeding the Si (111) crystal. With the use of a fluorescence-based X-ray beam position monitor (BPM) placed 19 m away from the monochromator, much operational experience has been gained on(More)
We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste Island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are(More)
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