Pablo Eugenio Salazar Rojas - Academia.edu (original) (raw)
Uploads
Papers by Pablo Eugenio Salazar Rojas
Latin American Journal of Aquatic Research, 2014
The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillone... more The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax), associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia) and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus), associated with the thermocline (12°C), and finally, larvae of the families Myctophidae (Diogenichthys atlanticus) and Bathylagidae (Bathylagus nigrigenys), associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.
Salud & Sociedad, 2011
Durante el año 2014 se resolvieron los concursos FONDECYT regular 2014 y de Iniciación a la inves... more Durante el año 2014 se resolvieron los concursos FONDECYT regular 2014 y de Iniciación a la investigación 2013. En el concurso de Iniciación a la Investigación, se presentaron 703 proyectos, de los cuales fueron aprobaron 308. De estos, 6 corresponden a Psicología (de un total de 20 proyectos postulados), por un valor de 358.897 millones de pesos, lo que constituye el 1,5% del total del financiamiento otorgado en esta categoría. En el concurso regular, de 1286 proyectos postulados, se aprobaron para financiamiento 581. De estos, 21 proyectos corresponden a Psicología (de un total de 45 presentados), por un valor de 2.097.829 millones, lo que equivale al 3,0% del monto total asignado a este concurso. Se presentan en este artículo especial, resúmenes de 20 proyectos aprobados para el área, los cuales comenzaron a ejecutarse en noviembre del 2013 (iniciación) y que estarán ejecutándose hasta el periodo 2016-2017. PALABRAS CLAVE: Psicología, FONDECYT, investigación.
Scientific Reports, 2017
Treponema pallidum subsp. pallidum, the causative agent of syphilis, is a highly invasive spiroch... more Treponema pallidum subsp. pallidum, the causative agent of syphilis, is a highly invasive spirochete pathogen that uses the vasculature to disseminate throughout the body. Identification of bacterial factors promoting dissemination is crucial for syphilis vaccine development. An important step in dissemination is bacterial adhesion to blood vessel surfaces, a process mediated by bacterial proteins that can withstand forces imposed on adhesive bonds by blood flow (vascular adhesins). The study of T. pallidum vascular adhesins is hindered by the uncultivable nature of this pathogen. We overcame these limitations by expressing T. pallidum adhesin Tp0751 (pallilysin) in an adhesion-attenuated strain of the cultivable spirochete Borrelia burgdorferi. Under fluid shear stress representative of conditions in postcapillary venules, Tp0751 restored bacterial-vascular interactions to levels similar to those observed for infectious B. burgdorferi and a gain-of-function strain expressing B. burgdorferi vascular adhesin BBK32. The strength and stability of Tp0751-and BBK32-dependent endothelial interactions under physiological shear stress were similar, although the mechanisms stabilizing these interactions were distinct. Tp0751 expression also permitted bacteria to interact with postcapillary venules in live mice as effectively as BBK32-expressing strains. These results demonstrate that Tp0751 can function as a vascular adhesin. Treponema pallidum subsp. pallidum is a bacterium from the spirochete family and the causative agent of syphilis. Syphilis is a sexually transmitted disease, which is often considered a disease of the past. However, it still represents a global health problem with 36 million cases and 11 million new infections annually 1. Moreover, syphilis incidence has increased dramatically over the past two decades in Canada 2 , the United States 3 , China 4 , and in a number of European countries 5-7. Given its high prevalence, syphilis has a substantial impact on global health. Syphilis infection in pregnancy has up to 80% morbidity and can result in stillbirth, neonatal death, and complications associated with congenital syphilis in newborns 8. Active syphilis infection also significantly increases infectivity of HIV-positive patients and risk of HIV acquisition 9 , and modeling studies suggest that controlling syphilis will contribute to HIV prevention 10. Since elimination of syphilis has not been achieved by antibiotic treatment, novel preventative approaches are needed to fight this disease. To date, the molecular mechanisms of T. pallidum pathogenesis are still poorly understood. This is mainly because the organism is an obligate human pathogen that cannot be cultured continuously in vitro 11. The inability to culture T. pallidum has limited the use of many experimental approaches, including genetic manipulation to
Anaerobe, Jan 12, 2017
During six years as German National Consultant Laboratory for Spirochetes we investigated 149 int... more During six years as German National Consultant Laboratory for Spirochetes we investigated 149 intestinal biopsies from 91 patients, which were histopathologically diagnosed with human intestinal spirochetosis (HIS), using fluorescence in situ hybridization (FISH) combined with 16S rRNA gene PCR and sequencing. Aim of this study was to complement histopathological findings with FISH and PCR for definite diagnosis and species identification of the causative pathogens. HIS is characterized by colonization of the colonic mucosa of the human distal intestinal tract by Brachyspira spp. Microbiological diagnosis of HIS is not performed, because of the fastidious nature and slow growth of Brachyspira spp. in culture. In clinical practice, diagnosis of HIS relies solely on histopathology without differentiation of the spirochetes. We used a previously described FISH probe to detect and identify Brachyspira spp. in histological gut biopsies. FISH allowed rapid visualization and identification...
Latin American Journal of Aquatic Research, 2014
The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillone... more The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax), associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia) and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus), associated with the thermocline (12°C), and finally, larvae of the families Myctophidae (Diogenichthys atlanticus) and Bathylagidae (Bathylagus nigrigenys), associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.
Salud & Sociedad, 2011
Durante el año 2014 se resolvieron los concursos FONDECYT regular 2014 y de Iniciación a la inves... more Durante el año 2014 se resolvieron los concursos FONDECYT regular 2014 y de Iniciación a la investigación 2013. En el concurso de Iniciación a la Investigación, se presentaron 703 proyectos, de los cuales fueron aprobaron 308. De estos, 6 corresponden a Psicología (de un total de 20 proyectos postulados), por un valor de 358.897 millones de pesos, lo que constituye el 1,5% del total del financiamiento otorgado en esta categoría. En el concurso regular, de 1286 proyectos postulados, se aprobaron para financiamiento 581. De estos, 21 proyectos corresponden a Psicología (de un total de 45 presentados), por un valor de 2.097.829 millones, lo que equivale al 3,0% del monto total asignado a este concurso. Se presentan en este artículo especial, resúmenes de 20 proyectos aprobados para el área, los cuales comenzaron a ejecutarse en noviembre del 2013 (iniciación) y que estarán ejecutándose hasta el periodo 2016-2017. PALABRAS CLAVE: Psicología, FONDECYT, investigación.
Scientific Reports, 2017
Treponema pallidum subsp. pallidum, the causative agent of syphilis, is a highly invasive spiroch... more Treponema pallidum subsp. pallidum, the causative agent of syphilis, is a highly invasive spirochete pathogen that uses the vasculature to disseminate throughout the body. Identification of bacterial factors promoting dissemination is crucial for syphilis vaccine development. An important step in dissemination is bacterial adhesion to blood vessel surfaces, a process mediated by bacterial proteins that can withstand forces imposed on adhesive bonds by blood flow (vascular adhesins). The study of T. pallidum vascular adhesins is hindered by the uncultivable nature of this pathogen. We overcame these limitations by expressing T. pallidum adhesin Tp0751 (pallilysin) in an adhesion-attenuated strain of the cultivable spirochete Borrelia burgdorferi. Under fluid shear stress representative of conditions in postcapillary venules, Tp0751 restored bacterial-vascular interactions to levels similar to those observed for infectious B. burgdorferi and a gain-of-function strain expressing B. burgdorferi vascular adhesin BBK32. The strength and stability of Tp0751-and BBK32-dependent endothelial interactions under physiological shear stress were similar, although the mechanisms stabilizing these interactions were distinct. Tp0751 expression also permitted bacteria to interact with postcapillary venules in live mice as effectively as BBK32-expressing strains. These results demonstrate that Tp0751 can function as a vascular adhesin. Treponema pallidum subsp. pallidum is a bacterium from the spirochete family and the causative agent of syphilis. Syphilis is a sexually transmitted disease, which is often considered a disease of the past. However, it still represents a global health problem with 36 million cases and 11 million new infections annually 1. Moreover, syphilis incidence has increased dramatically over the past two decades in Canada 2 , the United States 3 , China 4 , and in a number of European countries 5-7. Given its high prevalence, syphilis has a substantial impact on global health. Syphilis infection in pregnancy has up to 80% morbidity and can result in stillbirth, neonatal death, and complications associated with congenital syphilis in newborns 8. Active syphilis infection also significantly increases infectivity of HIV-positive patients and risk of HIV acquisition 9 , and modeling studies suggest that controlling syphilis will contribute to HIV prevention 10. Since elimination of syphilis has not been achieved by antibiotic treatment, novel preventative approaches are needed to fight this disease. To date, the molecular mechanisms of T. pallidum pathogenesis are still poorly understood. This is mainly because the organism is an obligate human pathogen that cannot be cultured continuously in vitro 11. The inability to culture T. pallidum has limited the use of many experimental approaches, including genetic manipulation to
Anaerobe, Jan 12, 2017
During six years as German National Consultant Laboratory for Spirochetes we investigated 149 int... more During six years as German National Consultant Laboratory for Spirochetes we investigated 149 intestinal biopsies from 91 patients, which were histopathologically diagnosed with human intestinal spirochetosis (HIS), using fluorescence in situ hybridization (FISH) combined with 16S rRNA gene PCR and sequencing. Aim of this study was to complement histopathological findings with FISH and PCR for definite diagnosis and species identification of the causative pathogens. HIS is characterized by colonization of the colonic mucosa of the human distal intestinal tract by Brachyspira spp. Microbiological diagnosis of HIS is not performed, because of the fastidious nature and slow growth of Brachyspira spp. in culture. In clinical practice, diagnosis of HIS relies solely on histopathology without differentiation of the spirochetes. We used a previously described FISH probe to detect and identify Brachyspira spp. in histological gut biopsies. FISH allowed rapid visualization and identification...