Comparison of sulfur isotope ratio measurements by various techniques, and the δ(34)S values of some sulur standards

Three techniques (combustion of Ag(2)S by Cu(2)O, thermal decomposition of BaSO(4) and KIBA reagent method under vacuum) for sulfur isotope ratio measurements of geological samples are described in detail. The δ(34)S values of three working standards (MSS-2, MSS-3 and MSS-4) obtained by these techniques for the last 13 years were compared (Table 1 and Fig. 3): the most acceptable values of the three standards are +21.5, +3.5 and +4.5‰, respectively

Estrategias de exportación y producción de cobre de las pymes mineras de la región sur del Perú, 2017

La presente investigación titulada Estrategias de Exportación y Producción de cobre de las Pymes mineras de la región sur del Perú, 2017, tuvo como objetivo principal determinar la relación que existe entre las estrategias de exportación con la producción de cobre de las Mypes de la región sur del país, 2017. El tipo de investigación fue aplicada de nivel correlacional y diseño no experimental. Se utilizó como población 20 Mypes peruanas que exportan el cobre en sus diferentes presentaciones de la región sur del Perú, y la muestra fue el 100% de la población. La validez del instrumento se obtuvo mediante juicio de expertos y la confiabilidad con el coeficiente del alfa de Cronbach. La recolección de datos se obtuvo a través de dos cuestionarios con 39 ítems con escala de 5 categorías. El análisis de datos se hizo utilizando el programa estadístico SPSS versión 25 llegando a evidenciar que existe relación moderada entre las estrategias de exportación y la producción del cobre de las mypes mineras de la región sur del Perú, 201

Differential Regulation of Gene Expression of Alveolar Epithelial Cell Markers in Human Lung Adenocarcinoma-Derived A549 Clones

Stem cell therapy appears to be promising for restoring damaged or irreparable lung tissue. However, establishing a simple and reproducible protocol for preparing lung progenitor populations is difficult because the molecular basis for alveolar epithelial cell differentiation is not fully understood. We investigated an in vitro system to analyze the regulatory mechanisms of alveolus-specific gene expression using a human alveolar epithelial type II (ATII) cell line, A549. After cloning A549 subpopulations, each clone was classified into five groups according to cellmorphology andmarker gene expression. Two clones (B7 and H12)were further analyzed. Under serum-free culture conditions, surfactant protein C (SPC), an ATII marker, was upregulated in both H12 and B7. Aquaporin 5 (AQP5), an ATI marker, was upregulated in H12 and significantly induced in B7. When the RAS/MAPK pathway was inhibited, SPC and thyroid transcription factor-1 (TTF-1) expression levels were enhanced. After treatment with dexamethasone (DEX), 8-bromoadenosine 3’5’-cyclic monophosphate (8-Br-cAMP), 3-isobutyl-1-methylxanthine (IBMX), and keratinocyte growth factor (KGF), surfactant protein B and TTF-1 expression levels were enhanced. We found that A549-derived clones have plasticity in gene expression of alveolar epithelial differentiation markers and could be useful in studying ATII maintenance and differentiation

EFSO at different geographical locations verified with observing-system experiments

ひとつひとつの観測データが気象予測に与える影響を簡易に評価する手法を確認 --北極の観測データは7日先の北米気象予測の改善に貢献することも明らかに--. 京都大学プレスリリース. 2021-04-30.An ensemble-based forecast sensitivity to observations (EFSO) diagnosis has been implemented in an atmospheric general circulation model–ensemble Kalman filter data assimilation system to estimate the impacts of specific observations from the quasi-operational global observing system on weekly short-range forecasts. It was examined whether EFSO reasonably approximates the impacts of a subset of observations from specific geographical locations for 6-hour forecasts, and how long the 6-hour observation impacts can be retained during the 7-day forecast period. The reference for these forecasts was obtained from 12 data denial experiments in each of which a subset of three radiosonde observations launched from a geographical location was excluded. The 12 locations were selected from three latitudinal bands comprising (i) four Arctic regions, (ii) four midlatitude regions in the Northern Hemisphere, and (iii) four tropical regions during the Northern Hemisphere winter of 2015/16. The estimated winter-averaged EFSO-derived observation impacts well corresponded to the 6-hour observation impacts obtained by the data denials and EFSO could reasonably estimate the observation impacts by the data denials on short-range (6-hour to 2-day) forecasts. Furthermore, during the medium-range (4-day to 7-day) forecasts, it was found that the Arctic observations tend to seed the broadest impacts and their short-range observation impacts could be projected to beneficial impacts in Arctic and midlatitude North American areas. The midlatitude area located just downstream of dynamical propagation from the Arctic toward the midlatitudes. Results obtained by repeated Arctic data-denial experiments were found to be generally common to those from the non-repeated experiments

Growth Effects of Annuities and Government Transfers in Perpetual Youth Models

We show that in overlapping generations endogenous growth models with uncertain lifetime, the introduction of government transfers always increases economic growth by crowding out the private annuity market and increasing accidental bequests. In particular, if the government imposes a flat-rate consumption tax (which is neutral to the consumption-saving margin), uses part of the tax revenue for unproductive purposes, and rebates the rest equally across agents as a lump-sum transfer, the economy grows faster and improves the welfare of future generations