Evaluación de reservas. Yacimiento salino de Puite

El presente estudio elaborado por el INGEMMET, es el tercero que se ejecuta en el yacimiento salino de Puite, de propiedad de la Empresa de la Sal EMSAL, que mediante la firma de convenio N ° 046-AL-EMSAL del 17 de setiembre de 1986 y el Adendum del 14 de noviembre, encomienda al INGEMMET a ejecutar tales estudios. Las investigaciones a realizar en este tercer estudio tienen por objeto determinar las posibilidades de ubicar reservas de sal económicamente explotables en el yacimiento de Puite, el mismo que se encuentra ubicado en el paraje del mismo nombre, distrito de lte, provincia y departamento de Tacna

Summary of Pb isotopic compositions in epitermal precios metal deposits, Orcopampa área of Southern Peru, Berenguela area of Western Bolivia, and the Maricunga belt in north-central Chile

The Mesozoic and Cenozoic Central Andes are divided into three Pb isotopic provinces, based upon the Pb isotopic compositions of ore minerals (MacFarlane et al., 1990). Macfarlane et al., 0990), furthermore, argue that the Pb isotopic compositions of the ore minerals reílect those of the igneous rocks associated with the deposits. Province I lies along the coast of Perú, Chile, and westernmost Bolivia. Mcsozoic and early Cenozoic volcapic and plutonic ares built upon a rifted and thinned continental margin dominate this province. Three subprovinces are distinguished based upon slight differences in Pb isotopic compositions. Province la includes northern and central Chile south of 19°S; province lb includes central Perú north of 13°S; whereas province le includes central and southern Perú between the two other subprovinces. Province II lies in the high Andes of central Perú and, perhaps, in northern Chile and Argentina, where miogeoclinal sedimentary rocks crop out and the crust underwent a lower magnitude of extension in the early Mesozoic. This region generally represents a back-arc position relative to the Mesozoic and early Cenozoic magmatic ares, and extensive magmatism related to the Andean cycle has only occurred since the Oligocene. Paleozoic ares are the dominant basement in this province. Province III lies in the Cordillera Oriental and Altiplano of Perú and Bolivia where Paleozoic, Mesozoic, and Cenozoic sedimentary rocks are multiply dcformed by thrust faults. Magma ti-e episodes of Triassic to Jurassic and Oligocene to Miocene age are documented. Proterozoic rocks of the Brazilian shicld are underthrust beneath the Cordillera Oriental, with the youngest shortcning episode beginning in the Oligocene. Province III is subdivided into two subprovinces: ma lies in southeastern Perú where both episodes of magmatism occurred, whereas IIIb lies in Bolivia where magmatism is primarily of Oligocene and Miocene age. Pb isotopic compositions for Province I are slightly less radiogenic than those from province II, whereas province III isotopic compositions are much more varied with consistently higher 207Pb/ 204pb and 208pb/204pb at a given 206pb/ 204pb_Province I Pb isotopic compositions (206pb/ 204pb =18.21-18.82; 207Pb/2<YíPb = 15.55-15.69; 2º8Pb/2º4Pb = 38.11-38.95) overlap with and extend below the average crustal growth curve of Staccy and Kramers (1975) on the uranogenic diagram (207pb/204pb versus 206pb/204Pb). Province lT Pb isotopic compositions (206pb/2<Yípb = 18.76-18.90; 207pb/204pb 15.62-15.73; 208pb/204pb 38.63-39.16) and Province III Pb isotopic compositions (206pb/204Pb 17.97-25.18; 207pb/204pb 15.51-16.00; 208pb/20/4pb 37.71-40.07) lie above the average crustal growth curve on the same diagram. The Pb isotopic compositions from these last two provinces require contribution from a high mu (238U/204pb) Proterozoic or Archean source. On the thorogcnic Pb isotopic variation diagram (208Pb/ 204Pb versus 206pb/204pb), isotopic compositions for province I, 11, and IIIa scatter along the average crustal growth curve of Stacey and Kramers (1975-) indicating that a time averaged Th/U ratio - 4 (the average cristal value) characterizes the Central Andes. Pb isotopic compositions for province IIIb are the most radiogenic and also the most heterogeneous. The variable radiogenic Pb isotopic compositions of province III suggcst heterogeneous upper cristal sources, whereas the isotopic compositions of province I probably reflect a mafic cristal lithospheric source, probably modified by subduction processcs. Province II isotopic compositions conceivably represent a mix betwecn the two model reservoirs

Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry

Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality

Animales en la poesía : una selección

RESUMEN : La presente es una antología de poemas sobre animales que hemos decidido llamar así, simplemente, Animales en la poesía, distinto al título de Bestiario, que contemplamos inicialmente, debido a cierta generalización que, bajo ese nombre, se reúne animales de toda índole, incluso aquellos pequeños animales que poco prefiguran un bestiario. Esta designación, justamente, designaría una reunión de bestias y estas están definidas, genéricamente, como animales de cuatro patas; entonces ello desmentiría o se prestaría para equívocos...CONTENIDO : Animales en la poesía. -- Kuyata. -- Poema con caballos rojos. -- Un cruce. -- Insectos en la misa. -- Gato casero. -- El gallinazo gira sobre los árboles. -- La serpiente que danza. -- El dragón azulado. -- A un perro. -- Ciervo. -- Cervatillo. -- Avechucho. -- Necoclí. -- Pez muerto. -- En el bosque, al lado del mar. -- Sobre las colinas. -- La perrita coja. -- El loro. -- Giran, giran. -- Pájaros. -- Cangrejos en el Morrosquillo. -- Garcilla bueyera. -- El burro. -- El gatopájaro. -- Bestia mía. -- Habla la vaca (fragmento). -- Un pueblo de amos... -- La mosca. -- Una avispa sobre el agua. -- Hormiga y faraona. -- Tulipanes rojos. -- La mariposa. -- El armadillo. -- Olvidadas ya la libertad y la floresta. -- Verdor. -- Reciclando. -- Milacos. -- Respuesta al párroco. -- La más pequeña abeja. -- El cóndor. -- La canción de los osos. -- Espíritu de pájaro. -- Aves de mar. -- La sirena. -- Un mono

Proyecto Mazo Cruz: resumen de actividades 1993

A consecuencia del proyecto BID-INGEMMET, se desarrolló en 1991 un programa de prospección de yacimientos epitermales en el extremo Sur del Perú. La interpretación de imágenes de satélite y el subsecuente control de campo de varias áreas anómalas, resultó en 1992 en la solicitud de un área de no admisión de denuncios denominado " Mazo Cruz": En el presente año se han realizado 3 campañas de campo, alcanzando los siguientes resultados: - Reconocimiento geológico regional en los alrededores del área del Proyecto (Mazo Cruz - Huacullani - Pizacoma - Tupala). El área se encuentra en volcánicos de la Formación Barroso, mostrando amplias zonas de alteración, aparentemente controlada por el régimen de la tectónica regional (sistemas de fallas N 15 ·E 1 E-W). Las alteraciones afloran dentro de dos amplias estructuras estrato-volcánicas, que han experimentado varias fases de destrucción y subsecuentes fases de reactivación magmáticas. Las mineralizaciones están relacionadas a estas fases posteriores. -Prospección de la zona, resultando en la ubicación de una serie de alteraciones hidrotermales (propilitización, argilitización, silicificación) de un área total de aproximadamente 20 Km. Entre las más expectantes tenemos: JAPO, YULACA, ARICHUA y APACHETA. -SECTOR Cos. YULACA: 3.5 x 2.5 Km. La zona de alteración y mineralización más amplia e importante, se caracteriza por un centro silicificado (Co. Sílice) con "vuggy silica" y el afloramiento de brechas hidrotermales con leyes de oro que alcanzan 1 gr./ton. Hacia los márgenes predomina la argilitizaci6n. Además, existe una mineralización tipo veta (Pb, Zn, Cu) dentro de un entorno propilitizado. Igualmente, argilitizado silicificado; además, existe una zona limitada alteración tipo stockwork. -SECTOR JAPO 4 X 2 Km. - SECTOR ARICHUA: 1 x 1 Km. menos interesante. - SECTOR APACHETA 1. 5 x 1. 5 Km. Semejante a Yulaca y bastante expectante con zonas de silicificación hasta "vuggy silica” dentro de un "anillo" de argilitización

Reconocimiento geológico e investigaciones de depósitos minerales en el ambiente volcánico Neógeno y Cuaternario del departamento de Arequipa, sur del Perú

El presente informe es el resultado del estudio de reconocimiento de un área cubierta por tres cuadrantes de 2 escenas del Thematic Mapper, mayormente de las partes altoandinas del departamento de Arequipa y que se extiende hacia los departamentos adyacentes de Ayacucho y Cuzco (Fig. 1). El área de estudio comprende aproximadamente 24,000 km. El estudio fue parte del Programa Internacional de Adiestramiento para la Investigación de Recursos Auro-argentíferos en 300,000 km2 en rocas volcánicas neógenas y cuaternarias de los Andes Centrales. Este programa ha sido financiado por el Banco Interamericano de Desarrollo (BID) y fue llevado a cabo por las Instituciones Geológicas Nacionales de Perú (INGEMMET), Bolivia (GEOBOL) y Chile (SERNAGEOMIN), con el asesoramiento del U. S. Geological Survey (USGS), durante el período de junio de 1990 a diciembre de 1992. El área de estudio fue seleccionada por la presencia de rocas volcánicas huéspedes, yacimientos epitermales de metales preciosos, algunos de los cuales fueron explotados durante la época de la Colonia, y por qué el área posee un potencial significativo para el descubrimiento de nuevos yacimientos de metales preciosos. Las principales minas en operación O 992) son: Arcata, Caylloma, Orcopampa, y Shila. Estas minas y otros depósitos conocidos consisten principalmente de vetas bien definidas que fueron fácilmente localizadas. Las abundantes zonas de alteración hidrotermal en esta región, que parecen no tener depósitos explotables en superficie, podrían tener yacimientos ecónómicos "ciegos" en profundidad. En consecuencia, los mayores esfuerzos estuvieron dirigidos a ubicar tales zonas de alteración

The Long-Term Maintenance of Upper Limb Motor Improvements Following Transcranial Direct Current Stimulation Combined with Rehabilitation in People with Stroke: A Systematic Review of Randomized Sham-Controlled Trials

Background: The effectiveness of transcranial direct current stimulation (tDCS) in the upper limb (UL) motor rehabilitation of stroke has been widely studied. However, the long-term maintenance of its improvements has not yet been proven. Methods: A systematic search was conducted in MEDLINE/Pubmed, Web of Science, PEDRo, and Scopus databases from inception to April 2021. Randomized controlled trials were included if they performed a tDCS intervention combined with UL rehabilitation in stroke patients, performed several sessions (five or more), and assessed long-term results (at least three-month follow-up). Risk of bias and methodological quality were evaluated with the Cochrane RoB-2 and the Oxford quality scoring system. Results: Nine studies were included, showing a high methodological quality. Findings regarding UL were categorized into (1) functionality, (2) strength, (3) spasticity. All the studies that showed significant improvements retained them in the long term. Baseline functionality may be a limiting factor in achieving motor improvements, but not in sustaining them over the long term. Conclusion: It seems that the improvements achieved during the application of tDCS combined with UL motor rehabilitation in stroke were preserved until the follow-up time (from 3 months to 1 year). Further studies are needed to clarify the long-term effects of tDCS

Refractive predictability and visual outcomes of an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis

Purpose: To evaluate the refractive predictability obtained with an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis, confirming which intraocular lens power formula provides the most accurate calculation. Methods: The study enrolled 71 eyes with previous successful myopic laser in situ keratomileusis surgery of 43 patients undergoing cataract surgery with implantation of the extended range of vision intraocular lens TECNIS Symfony (Johnson and Johnson Vision). Intraocular lens power was calculated using all American Society of Cataract and Refractive Surgeons formulas, and their average value was selected for implantation. Refractive outcomes were evaluated at 3 months postoperatively. Results: Postoperative spherical equivalent within ±0.50 and ±1.00 D was found in 61.6% and 86.3% of eyes, respectively. In eyes with pre-laser in situ keratomileusis data available, no significant correlation was found between pre-laser in situ keratomileusis spherical equivalent and post-cataract surgery spherical equivalent (r = 0.237, p = 0.114). A postoperative spherical equivalent within ±0.50 D was found in 65.2% and 55.6% of eyes in the subgroups with and without pre-laser in situ keratomileusis data available, respectively (p = 0.480). Statistically significantly higher differences between the intraocular lens power implanted and the calculation provided by the Potvin–Hill (p = 0.028) and Barrett True K No History formulas (p = 0.022) were found in those eyes with postoperative spherical equivalent > 0.50 D. Conclusion: The extended range of vision intraocular lens evaluated can provide a predictable refractive correction in eyes with previous laser in situ keratomileusis surgery. The Potvin–Hill and Barrett True K No History are the most adequate formulas to perform intraocular lens power calculations in these cases