Outsourcing of functions in El Teniente Division at Codelco Chile

The primary purpose of this study is to determine the vision of contract administrators with regard to the administration and monitoring of contracts between El Teniente Division and outside companies. The results obtained based on a series of interviews and a survey produced evidence that shows that there is an outsourcing system, which consists of a set of rules and procedures aimed at regulating the purchase of goods or contracting works or services, designed to ensure performance of contracts with third-party companies. It is at this stage that they found the main issues in the contractor management system. In the future we expect to be able to investigate this subject in other state-owned companies.

A comparison of energy efficiency certification in housing: a study of the Chilean and Spanish cases

Faced with implementing policies that seek to improve the energy efficiency of housing and reduce the impact of CO2 emissions, several countries are introducing (unilaterally or by international agreement) energy certification systems that allow the effects of these policies to be evaluated. This study aims to compare the energy efficiency certification systems in Spain and Chile, identifying convergent and divergent parameters, enabling the existing gaps to be identified and improvements noted for both systems. To do so, 20 sample dwellings in Santiago de Chile were evaluated, along with the local calculating tools in both countries. The analysis considered the aspects of regulation, its reach, the characterization of the models and the necessary indicators. The comparison identified, among others, differences such as obligatory implementation of the system, a study of the existing buildings in the focus area, the prevailing indicators for evaluating the effects of the buildings, the low incidence of mixed energy systems in the Chilean system and the possibility of proposing and evaluating improvements in the Spanish system. As a result, higher energy requirements and greater CO2 emissions were identified in the Chilean system, reaching differences of 42 kWh/m2/year in consumption and 14 kgCO2/ m2/year in emissions with regard to the Spanish qualification. The results of this comparison have facilitated the identification of improvements that will increase the evaluation standards of the Chilean system.Peer ReviewedPostprint (published version

Metabolic Imbalance Effect on Retinal Müller Glial Cells Reprogramming Capacity: Involvement of Histone Deacetylase SIRT6

Retinal Müller glial cells (MGs) are among the first to demonstrate metabolic changes during retinal disease and are a potential source of regenerative cells. In response to a harmful stimulus, they can dedifferentiate acquiring neural stem cells properties, proliferate and migrate to the damaged retinal layer and differentiate into lost neurons. However, it is not yet known how this reprogramming process is regulated in mammals. Since glucose and oxygen are important regulatory elements that may help directing stem cell fate, we aimed to study the effect of glucose variations and oxidative stress in Müller cells reprogramming capacity and analyze the participation the histone deacetylase SIRT6, as an epigenetic modulator of this process. We found that the combination of high glucose and oxidative stress induced a decrease in the levels of the marker glutamine synthetase, and an increase in the migration capacity of the cells suggesting that these experimental conditions could induce some degree of dedifferentiation and favor the migration ability. High glucose induced an increase in the levels of the pluripotent factor SOX9 and a decrease in SIRT6 levels accompanied by the increase in the acetylation levels of H3K9. Inhibiting SIRT6 expression by siRNA rendered an increase in SOX9 levels. We also determined SOX9 levels in retinas from mice with a conditional deletion of SIRT6 in the CNS. To further understand the mechanisms that regulate MGs response under metabolic impaired conditions, we evaluated the gene expression profile and performed Gene Ontology enrichment analysis of Müller cells from a murine model of Diabetes. We found several differentially expressed genes and observed that the transcriptomic change involved the enrichment of genes associated with glucose metabolism, cell migration, development and pluripotency. We found that many functional categories affected in cells of diabetic animals were directly related to SIRT6 function. Transcription factors enrichment analysis allowed us to predict several factors, including SOX9, that may be involved in the modulation of the differential expression program observed in diabetic MGs. Our results underline the heterogeneity of Müller cells response and the challenge that the study of metabolic impairment in vivo represents.Fil: Sanhueza Salas, L. Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: García Venzor, Alfredo. Ben Gurion University of the Negev; IsraelFil: Beltramone, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Capurro, Claudia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Toiber, Debra. Ben Gurion University of the Negev; IsraelFil: Silberman, Dafne Magalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

Role for Tetrahydrobiopterin in the Fetoplacental Endothelial Dysfunction in Maternal Supraphysiological Hypercholesterolemia

Maternal physiological hypercholesterolemia occurs during pregnancy, ensuring normal fetal development. In some cases, the maternal plasma cholesterol level increases to above this physiological range, leading to maternal supraphysiological hypercholesterolemia (MSPH). This condition results in endothelial dysfunction and atherosclerosis in the fetal and placental vasculature. The fetal and placental endothelial dysfunction is related to alterations in the L-arginine/nitric oxide (NO) pathway and the arginase/urea pathway and results in reduced NO production. The level of tetrahydrobiopterin (BH4), a cofactor for endothelial NO synthase (eNOS), is reduced in nonpregnant women who have hypercholesterolemia, which favors the generation of the superoxide anion rather than NO (from eNOS), causing endothelial dysfunction. However, it is unknown whether MSPH is associated with changes in the level or metabolism of BH4; as a result, eNOS function is not well understood. This review summarizes the available information on the potential link between MSPH and BH4 in causing human fetoplacental vascular endothelial dysfunction, which may be crucial for understanding the deleterious effects of MSPH on fetal growth and development

Conservative treatment of Ameloblastoma: report of 2 cases and review of the literature

Introduction: Ameloblastomas correspond to one of the most prevalent odontogenic tumors in developing countries, they are mainly located in the mandible, and their treatment has been widely discussed over the years, using radical or conservative treatments depending on different variables. Clinical case: We present two cases of patients with Ameloblastoma who underwent conservative treatment without the use of adjuvant therapy, obtaining satisfactory results evaluated in the medium term. Discussion: Due to a possible recurrence with conservative treatment, radical management has been suggested, however, the choice of treatment should be based on a series of clinical, histological and radiographic characteristics. Introducción: Los Ameloblastomas corresponden a uno de los tumores odontogénicos más prevalentes en los países en desarrollo, se ubican principalmente en la mandíbula, y su tratamiento ha sido ampliamente discutido a lo largo de los años, utilizando tratamientos radicales o conservadores dependiendo de distintas variables. Caso clínico: Se presentan dos casos de pacientes con un Ameloblastoma a quienes se les realizó tratamiento conservador sin uso de terapia coadyuvante, obteniendo resultados satisfactorios evaluados a mediano plazo. Discusión:  Debido a una posible recurrencia con un tratamiento conservador, se ha sugerido manejo radical, sin embargo, la elección de tratamiento debe ser en base a una serie de características clínicas, histológicas y radiográficas

Rehabilitación fija sobre dos implantes cortos ferulizados en vano desdentado maxilar posterior atrófico

Background: A problem when planning implants in long-standing toothless areas is the atrophy of the alveolar ridge close to the maxillary sinus1. Additional surgical procedures (maxillary sinus lift and grafts) are usually performed to install conventional implants (≥10mm in length), involving high morbidity, invasiveness, prolonged healing periods, and high treatment costs2. A solution to this problem is the use of short implants (<10mm in length).The objective is to document the use of short implants as a successful alternative in implant-supported rehabilitation of the free end span in the posterior maxillary area with low bone height. Clinical Presentation: Female patient, 62 years old, with no relevant medical history, consulted for the rehabilitation of teeth 14 and 15 extracted 10 years ago. On clinical examination, the scarce bone height of the left posterior maxillary space was evidenced. Radiographically there was proximity to the maxillary sinus.Short implants of 5 mm wide and 7 long were installed for tooth 14 and 5 mm wide and 6 long for tooth 15 (Unitite Prime Compact, SIN Brand), being rehabilitated and splinted using a fixed prosthesis cemented on an abutment of titanium. 12 months after rehabilitation, she maintained excellent functional results. Clinical Relevance: The literature reports that short implants are a viable treatment alternative in atrophic ridges, demonstrating a satisfactory survival rate similar to long implants but with less marginal bone loss, risk of complications, surgical time, and cost of treatment3,4.When multiple short implants are required, splinted restorations can be performed, increasing the area of occlusal resistance to axial forces, distributing less load towards the cement, implant abutment, and peri-implant interface. Rehabilitations of this type have shown fewer prosthetic complications, screw loosening, and the number of failed implants4. Conclusion: Rehabilitation using short splinted implants is a valid option for rehabilitating posterior areas of the atrophic maxilla, avoiding the need for complementary surgeries, obtaining satisfactory survival rates with low complications and better prosthetic prognosis than long implants after additional surgical techniques and short non-splinted implants.Antecedentes: Una problemática al planificar implantes en zonas desdentadas de larga data, es la atrofia del reborde alveolar cercano al seno maxilar1. Se realizan procedimientos quirúrgicos adicionales (elevación de seno maxilar e injertos), para instalar implantes convencionales (≥10mm de longitud), que implican una alta morbilidad, invasividad, curación prolongada y altos costos de tratamiento2. Una solución es el uso de implantes cortos (<10mm de longitud).Presentación Clínica: Paciente sexo femenino, 62 años, sin antecedentes médicos de relevancia, consulta por rehabilitación de dientes 14 y 15 extraídos hace 10 años. Al examen se evidencia escasa altura ósea. Radiográficamente existe cercanía con el seno maxilar.Se instalaron implantes cortos para los dientes 14 y 15, siendo rehabilitados y ferulizados mediante prótesis fija cementada sobre pilar de titanio. A 12 meses de la rehabilitación, mantuvo excelentes resultados funcionales.Relevancia Clínica: La literatura reporta que los implantes cortos son una alternativa de tratamiento viable en crestas atróficas, demostrando una tasa de supervivencia satisfactoria similar a los implantes largos pero con menor pérdida ósea marginal, riesgo de complicaciones, tiempo quirúrgico y costo del tratamiento3,4.Cuando se requieren múltiples implantes cortos, se pueden realizar rehabilitaciones ferulizadas, aumentando el área de resistencia oclusal a fuerzas axiales, distribuyendo menor carga hacia el cemento, pilar de implante e interfaz periimplantaria. Rehabilitaciones de este tipo han demostrado menores complicaciones protésicas, aflojamiento de tornillos y número de implantes fallidos4.Conclusión: La rehabilitación mediante implantes cortos ferulizados es una opción válida para la rehabilitación sobre zonas posteriores del maxilar atrófico, evitando la necesidad de cirugías complementarias, obteniéndose tasas de supervivencia satisfactorias con bajas complicaciones y mejor pronóstico protésico que los implantes largos post técnicas quirúrgicas adicionales e implantes cortos no ferulizados

Interluquina-6 como biomarcador de éxito de tratamientos para tratornos temporomandibulares articulares

Objective: To evaluate IL-6 level changes in synovial fluid (SF) in the temporomandibular joint (TMJ) post-treatment of temporomandibular disorders (TMD).  Material and Methods: In a first search, MeSH terms were used in Pubmed. A second one was conducted in Pubmed and the Cochrane Library, with MeSH terms and keywords in an advanced search. Inclusion criteria were all systematic reviews since 2015 on treatments for TMD, and clinical studies since 2015 where IL-6 levels were measured in SF post-treatment of TMD. Exclusion criteria were all studies where IL-6 levels were measured in plasma or joint tissue.Results: In the first search, 41 results were obtained per title and abstract, of which 15 systematic reviews remained meeting the inclusion criteria. In a second search, 35 results were obtained, of which 28 were excluded by title and abstract as they were not pertinent. After full reading, three randomized clinical studies remained that met the inclusion criteria. Conclusion: It is necessary to continue considering new therapeutic strategies to decrease levels of pro-inflammatory cytokines, where IL-6 might become a possible biomarker in TMD.Objetivo: Evaluar si cambia el nivel de IL-6 en liquido sinovial (LS) de articulación temporomandibular (ATM), post tratamiento de transtornos temporomandibulares (TTM) articulares. Especificos: Conocer los tratamientos efectivos para TTM articulares y explorar si existen cambios de nivel de IL-6 en LS post tratamiento de TTM articulares.Materiales y métodos: En una primera búsqueda se utilizaron términos MeSH en Pubmed. La segunda fue realizada en Pubmed y Cochrane Library, con términos MeSH y palabras claves en búsqueda avanzada. Criterios de inclusión: Revisiones sistemáticas desde 2015 sobre tratamientos para TTM articulares. Estudios clínicos desde 2015, donde se mida nivel de IL-6 en LS post tratamiento de TTM articulares. Criterios de exclusión: Estudios donde midan los niveles de IL-6 plasmáticos o en tejido articular.Resultados: En la primera búsqueda se encontraron 41 resultados; por título y resumen quedan 15 revisiones sistemáticas cumpliendo los criterios de inclusión. En la segunda 35 resultados; 28 fueron excluidos por título y resumen al no ser atingentes. Luego de lectura completa, quedan 3 estudios clínicos aleatorizados cumpliendo los criterios de inclusión. Conclusión: Es preciso seguir estudiando, buscando estrategias terapéuticas que puedan disminuir niveles de citoquinas proinflamatorias, siendo IL-6 un posible biomarcador en TTM articulares

Efectos en el uso de cobertor y bioestimulantes sobre número de frutos, peso fresco y peso seco en cerezo (Prunus avium L.) cv. Lapins y Santina

50 p.Durante los últimos años, el cultivo del cerezo ha incrementado su producción y exportación, posicionando a nuestro país como el principal exportador del hemisferio sur. Debido a la alta demanda de este frutal, su distribución geográfica se ha incrementado de manera exponencial en la zona centro y centro sur de nuestro país, caracterizándose por presentar condiciones edafoclimáticas privilegiadas para su producción. Dado los avances tecnológicos se han implementado varias tecnologías y productos que facilitan su producción. Entre estas tecnologías destacan el uso de bioestimulantes y de cobertores plásticos anti-partidura. La presente investigación tiene como objetivo evaluar el uso de cobertor plástico y aplicaciones foliares de bioestimulantes sobre el número de frutos y peso de la fruta en cerezos (Prunus avium L.) cv. Lapins y Santina en un huerto comercial. El presente estudio se realizó durante la temporada 2019-2020 en el valle de Pencahue, Región del Maule, en donde se evaluaron 4 ensayos: Lapins con y sin cobertura y Santina con y sin cobertura. Evaluándose además el uso de bio-estimulante, mediante un diseño en bloques completamente al azar con 3 repeticiones por tratamiento: i) T0 – control; ii) T1 – bio-estimulante Rezist; iii) T2 – bio-estimulante Bio-Hold; y iv) T3 – mezcla de ambos bio-estimulantes. El uso de bioestimulantes mostró diferencias significativas en el número de frutos de ambos cultivares. Algo similar se observó al utilizar cobertor plástico, registrando diferencias significativas entre los tratamientos, incrementando tanto en el peso como en el número de frutos en ambos cultivares. Con relación a los cultivares se observaron diferencias significativas entre ellos, registrando el mayor número y peso de frutos en el cv. Lapins

Ensamble de aves en zonas con diferente grado de urbanización en la ciudad de Bahía

La fragmentación y cambios en la vegetación se encuentran entre los procesos relacionados a la urbanización con mayor incidencia sobre las aves. El objetivo del trabajo es analizar las variaciones en el ensamble de aves según el grado de urbanización en la ciudad de Bahía Blanca, Buenos Aires. Se definieron 20 transectas de 100m de longitud (ambas veredas) en el micro-centro, macro-centro y periferia de la ciudad. Se realizaron dos muestreos semanales de octubre a diciembre de 2007. Se registró la riqueza y abundancia de aves, las perchas utilizadas y el número de automóviles/personas transitando por minuto. Se observaron 25 especies de aves, de las cuales las más comunes fueron Columba livia, Zenaida auriculata y Passer domesticus. Las transectas con mayor tránsito vehicular y peatonal mostraron las menores riquezas específicas. La mayoría de las aves observadas utilizaron árboles como perchas para posarse. Los gremios más representados fueron los granívoros, omnívoros e insectívoros. Nuestros resultados indican que el impacto de la urbanización sobre los ambientes naturales podría provocar la retracción de algunas especies y favorecer la expansión de otras ampliamente distribuidas.Fragmentation and vegetation changes are processes related to urbanization with an important incidence on birds. In this work we analize the bird assemblage variations along an urban gradient in Bahía Blanca city, Buenos Aires. Twenty transects were established, 100 metres long and 12 metres wide, in the micro-centre, macro-centre and the periphery of the city. Two samples a week were taken from october to december. We registered richness, bird abundance, perche-sites and number of vehicles/people per minute. Twenty five species were observed and Columba livia, Zenaida auriculata and Passer domesticus were the most common species. The transects with more vehicular and pedestrian traffic showed the minor specific richnesses. The most observed birds used trees as perche-sites. Granivores, omnivores and insectivores were the most represented guilds. Our results indicate that the impact of urbanization on natural environments could provoke the retraction of some species and promote the expansion of other of them widely distributed.Fil: Germain, Paola. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Cuevas, Yannina Andrea. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Sanhueza, Cristina del Carmen. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Tizón, Francisco Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Loydi, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: de Villalobos, Ana Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Zapperi, Georgina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Vazquez, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Pompozzi, Gabriel Alejandro. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Zoología de Invertebrados II; ArgentinaFil: Piovan, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Latitudinal Variation in the Toxicity and Sexual Compatibility of Alexandrium catenella Strains from Southern Chile

The bloom-forming toxic dinoflagellate Alexandrium catenella was first detected in southern Chile (39.5–55° S) 50 years ago and is responsible for most of the area’s cases of paralytic shellfish poisoning (PSP). Given the complex life history of A. catenella, which includes benthic sexual cysts, in this study, we examined the potential link between latitude, toxicity, and sexual compatibility. Nine clones isolated from Chilean Patagonia were used in self- and out-crosses in all possible combinations (n = 45). The effect of latitude on toxicity, reproductive success indexes, and cyst production was also determined. Using the toxin profiles for all strains, consisting of C1, C2, GTX4, GTX1, GTX3, and NeoSTX, a latitudinal gradient was determined for their proportions (%) and content per cell (pg cell−1), with the more toxic strains occurring in the north (−40.6° S). Reproductive success also showed a latitudinal tendency and was lower in the north. None of the self-crosses yielded resting cysts. Rather, the production of resting cysts was highest in pairings of clones separated by distances of 1000–1650 km. Our results contribute to a better understanding of PSP outbreaks in the region and demonstrate the importance of resting cysts in fueling new toxic events. They also provide additional evidence that the introduction of strains from neighboring regions is a cause for concern.En prens