1,298 research outputs found
Geology of the Bottle Lake Complex, Maine
Guidebook to the geology of Northeastern Maine and neighboring New Brunswick: The 72nd annual meeting of the New England Intercollegiate Geological Conference, Presque Isle, Maine, October 10-13, 1980: Trip A-
Remnant Colloform Pyrite at the Haile Gold Deposit, South Carolina: A Textural Key to Genesis
Auriferous iron sulfide-bearing deposits of the Carolina slate belt have distinctive mineralogical and textural features—traits that provide a basis to construct models of ore deposition. Our identification of paragenetically early types of pyrite, especially remnant colloform, crustiform, and layered growth textures of pyrite containing electrum and pyrrhotite, establishes unequivocally that gold mineralization was coeval with deposition of host rocks and not solely related to Paleozoic tectonic events. Ore horizons at the Haile deposit, South Carolina, contain many remnants of early pyrite: (1) fine-grained cubic pyrite disseminated along bedding; (2) finegrained spongy, rounded masses of pyrite that may envelop or drape over pyrite cubes; (3) fragments of botryoidally and crustiform layered pyrite, and (4) pyritic infilling of vesicles and pumice. Detailed mineral chemistry by petrography, microprobe, SEM, and EDS analysis of replaced pumice and colloform structures containing both arsenic compositional banding and electrum points to coeval deposition of gold and the volcanic host rocks and, thus, confirms a syngenetic origin for the gold deposits. Early pyrite textures are present in other major deposits of the Carolina slate belt, such as Ridgeway and Barite Hill, and these provide strong evidence for models whereby the sulfide ores formed prior to tectonism. The role of Paleozoic metamorphism was to remobilize and concentrate gold and other minerals in structurally prepared sites. Recognizing the significance of paragenetically early pyrite and gold textures can play an important role in distinguishing sulfide ores that form in volcanic and sedimentary environments from those formed solely by metamorphic processes. Exploration strategies applied to the Carolina slate belt and correlative rocks in the eastern United States in the Avalonian basement will benefit from using syngenetic models for gold mineralization
Effects of putrescine, cadaverine, spermine, spermidine and β-phenylethylamine on cultured bovine mammary epithelial cells
A bovine mammary epithelial cell line (BME-UV1) and three-dimensional collagen primary bovine organoids were used to evaluate the effects of cadaverine, putrescine, spermine, spermidine and β-phenylethylamine on mammary epithelial cells. Each biogenic amine was diluted in several concentrations (0-50 mM in BME-UV1 and 0-4 mM in primary bovine organoids) in the appropriate saline solution for the cell culture considered. In order to determine the activity of each compound tritiated thymidine incorporation was used. At low concentrations, all amines induced cell proliferation in both cultures. In BME-UV1, spermine significantly inhibited cell proliferation (P<0.001), while the other amines inhibited at higher concentrations (50mM). In primary bovine organoids, β−phenylethylamine significantly (P<0.001) inhibited cell proliferation at 4 mM. Organoids cultured in the presence of all amines, except β-phenylethylamine, had stellate projections indicating intense cell proliferation. Proliferation of mammary epithelial cells was stimulated at low concentrations, while at high concentrations it was inhibited. Our results suggested that the effects of each compound on mammary epithelial cells could be related to the compound itself and not to mediating by the bovine amino oxidase, responsible of the formation of toxic metabolites
Interleukin-8 expression in bronchoalveolar lavage cells in the evaluation of alveolitis in idiopathic pulmonary fibrosis
AbstractInterleukin-8 (IL-8) is a neutrophilic chemotactic factor which may have a prominent role in the attraction of neutrophils to the lung in idiopathic pulmonary fibrosis (IPF). The objective of this study was to investigate the usefulness of IL-8 expression in bronchoalveolar lavage (BAL) cells in the evaluation of alveolitis in IPF. We analysed the BAL cell expression of IL-8 by immunocytochemistry in 19 patients with IPF (six smokers, three ex-smokers and ten non-smokers) and in a control group composed of 14 individuals (six smokers, eight non-smokers). In IPF, BAL was performed on both the pulmonary lobe with the most extensive involvement and the one less extensively involved on high-resolution computed tomography (HRCT) scans. The percentages and absolute numbers of BAL IL-8+ macrophages from lobes with the most extensive HRCT scan involvement (36 ± 6% and (6 ± 2 × 104 ml−1) (SE) and from those less extensively involved [26% ± 4% and (6 ± 1) × 104 ml−1] were significantly higher with respect to both those from healthy smokers [17% ± 6% and (7 ± 4) × 104 ml−1] and those from non-smokers [2% ± 1% and (1 ± 0·3) × 104 ml−1] (P=0·005 and P=0·001, respectively), without differences between the two lobes. In contrast, both the proportions and the absolute numbers of BAL neutrophils in IPF were significantly higher in lobes with the most extensively involved HRCT scan in comparison with lobes with the least extensive involvement [13% ± 3%, (3 ± 1) × 104 ml−1 vs. 8% ± 2%, (1 ± 0·3) × 104 ml−1, P=0·05]. Moreover, the numbers of BAL neutrophils, but not those of IL-8+ macrophages, correlated with the extent of total pulmonary HRCT scan abnormalities in the most involved lobe (r=0·64, P=0·04). A correlation between neutrophils and IL-8+ cells was not observed. The results of this study suggest that, in IPF, BAL neutrophilia offers a better description of the disease inflammatory process than the expression of IL-8 in BAL cells
Influencia de la restricción de vitamina A en la dieta de cerdos ibéricos sobre el metabolismo y la transcripción de genes relacionados con lipogénesis
Vitamin A is a liposoluble vitamin obtained from the diet with multiple physiological actions in all animal tissues, including an antiadipogenic action which seems to be limited to muscular tissues. Thus, vitamin A restriction has been proposed as a strategy for improving meat and carcass quality in farm animals. In this work we have studied the effects of vitamin A dietary restriction on productive traits, tissue fatty acid composition and expression of a panel of adipogenic and lipogenic candidate genes in Iberian pigs. Forty Torbiscal pigs were fed with a standard or a Vitamin A restricted diet from two months of age till their sacrifice conducted in two batches, at 100 and 160 Kg live weight. Diet had no significant effect on growth, fatness, yields or intramuscular fat, but animals receiving no vitamin A supplementation showed higher monounsaturated fatty acids and lower saturated fatty acids in back fat and loin samples than the control ones. Adipose tissue SCD gene expression was higher in vitamin A restricted animals, as occurs with CRABP II expression. On the other hand, RXRG expression was higher in control group, in agreement with the influence on transcription of retinoic acid and its potential relationship with adipogenesis and lipogenesis.La vitamina A es una vitamina liposoluble obtenida de la dieta con numerosas funciones fisiológicas en los tejidos animales, incluyendo un efecto antiadipogénico aparentemente limitado al tejido muscular. La restricción de vitamina A se ha propuesto como una herramienta para mejorar la calidad de la canal y de la carne en animales de abasto. En el presente trabajo hemos estudiado el efecto de la restricción de vitamina A en el pienso sobre caracteres productivos, composición tisular de ácidos grasos y expresión de un panel de genes candidato con funciones adipogénicas y lipogénicas en cerdos ibéricos. Cuarenta cerdos de la estirpe Torbiscal fueron alimentados con pienso estándar o con pienso sin vitamina A en el corrector desde los dos meses de edad hasta su sacrificio, realizado en dos lotes (a 100 y 160 kg de peso vivo). La dieta no afectó al crecimiento, engrasamiento, rendimientos ni a la cantidad de grasa intramuscular, pero los animales restringidos mostraron una cantidad mayor de ácidos grasos monoinsaturados y menor de saturados en el tocino dorsal y en el lomo. El análisis de expresión génica en el tocino dorsal mostró una mayor expresión de SCD y CRABP II en el grupo restringido. Por otro lado, la expresión de RXRG fue mayor en el grupo control, en concordancia con el efecto modulador de la transcripción génica del ácido retinoico y su potencial relación con la adipogénesis y lipogénesis
Influence of natural ventilation due to buoyancy and heat transfer in the energy efficiency of a double skin facade building
In recent years, the interest in double skin facades has increased because of aesthetic reasons and for its use as passive system to save energy. Some authors have investigated their behavior related to thermal performance and energy efficiency compared to single skin facades but only considering the air cavity. The aim of this work is to identify a more efficient double glazed facade configuration that improves energy efficiency and indoor comfort conditions in buildings studying natural ventilation due to buoyancy-driven flow and heat transfer including solar radiation compared to a single skin facade. A simplified model was simulated using a computational fluid dynamics software to investigate the effects due to different cavity widths in winter and summer conditions with opened and closed vents and considering solar radiation or not. The main results obtained were that in winter closed vents is always efficient and ventilating is never beneficial. In summer closed vents is efficient in the absence of solar radiation and in its presence opened vents is favorable. Results showed the optimum air cavity width, and it was concluded that these double skin facades reduce the heating and cooling demands of a building, being more efficient compared to single skin facades
Not all shellfish "allergy" is allergy!
The popularity of shellfish has been increasing worldwide, with a consequent increase in adverse reactions that can be allergic or toxic. The approximate prevalence of shellfish allergy is estimated at 0.5-2.5% of the general population, depending on degree of consumption by age and geographic regions. The manifestations of shellfish allergy vary widely, but it tends to be more severe than most other food allergens
p73 deficiency results in impaired self renewal and premature neuronal differentiation of mouse neural progenitors independently of p53
10 p.-5 fig.The question of how neural progenitor cells maintain its self-renewal throughout life is a fundamental problem in cell biology with
implications in cancer, aging and neurodegenerative diseases. In this work, we have analyzed the p73 function in embryonic
neural progenitor cell biology using the neurosphere (NS)-assay and showed that p73-loss has a significant role in the
maintenance of neurosphere-forming cells in the embryonic brain. A comparative study of NS from Trp73-/-, p53KO, p53KO;Trp73-/-and their wild-type counterparts demonstrated that p73 deficiency results in two independent, but related, phenotypes: a smaller NS size (related to the proliferation and survival of the neural-progenitors) and a decreased capacity to
form NS (self-renewal). The former seems to be the result of p53 compensatory activity, whereas the latter is p53 independent.
We also demonstrate that p73 deficiency increases the population of neuronal progenitors ready to differentiate into neurons at the expense of depleting the pool of undifferentiated neurosphere-forming cells. Analysis of the neurogenic niches
demonstrated that p73-loss depletes the number of neural-progenitor cells, rendering deficient niches in the adult mice.
Altogether, our study identifies TP73 as a positive regulator of self-renewal with a role in the maintenance of the neurogenic
capacity. Thus, proposing p73 as an important player in the development of neurodegenerative diseases and a potential
therapeutic target.This work was supported by Grants SAF2009-
07897 from Spanish Ministerio de Ciencia e Innovacion (to MCM), Grant from Cajas de Ahorro de Castilla y León (to MCM), and Grants LE030A07 (to MMM) and
LE015A10-2 (to MCM) from the Junta de Castilla y León.Peer reviewe
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