3,394 research outputs found
Goldsmithing traditions and innovations in colonial Colombia: an analytical study of crucibles from Santa Cruz de Mompox
© 2019, © Society for Post-Medieval Archaeology 2019. SUMMARY: The 16th-century Spanish conquest of Colombia brought new technologies that altered and interacted with native metalworking traditions. In the colonial village of Santa Cruz de Mompox, renowned because of its goldsmithing tradition, indigenous groups and Spaniards experienced momentous encounters of individuals, metallurgical technologies and knowledge. However, little is known concerning colonial metallurgy, its continuities and changes with regards to the pre-Columbian period. Here we present the analytical characterization of five crucibles recovered in Mompox, together with discussion of relevant archival evidence. We find evidence for the local manufacture of crucibles as well as for the melting of unrefined gold dust, tumbaga (gold-copper-silver alloys) and silver. These metallurgical practices illustrate some likely illegal activities, continuities with pre-Columbian traditions in the use of tumbagas, and the Spanish-led introduction of silver in northern Colombia. It is argued that metallurgical remains can be informative of wider social and economic negotiations that engaged indigenous peoples, mestizos and Spaniards, which are critical to understand the configuration of the colonial reality
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Global Analysis of Predicted G Protein-Coupled Receptor Genes in the Filamentous Fungus, Neurospora crassa.
G protein-coupled receptors (GPCRs) regulate facets of growth, development, and environmental sensing in eukaryotes, including filamentous fungi. The largest predicted GPCR class in these organisms is the Pth11-related, with members similar to a protein required for disease in the plant pathogen Magnaporthe oryzae. However, the Pth11-related class has not been functionally studied in any filamentous fungal species. Here, we analyze phenotypes in available mutants for 36 GPCR genes, including 20 Pth11-related, in the model filamentous fungus Neurospora crassa. We also investigate patterns of gene expression for all 43 predicted GPCR genes in available datasets. A total of 17 mutants (47%) possessed at least one growth or developmental phenotype. We identified 18 mutants (56%) with chemical sensitivity or nutritional phenotypes (11 uniquely), bringing the total number of mutants with at least one defect to 28 (78%), including 15 mutants (75%) in the Pth11-related class. Gene expression trends for GPCR genes correlated with the phenotypes observed for many mutants and also suggested overlapping functions for several groups of co-transcribed genes. Several members of the Pth11-related class have phenotypes and/or are differentially expressed on cellulose, suggesting a possible role for this gene family in plant cell wall sensing or utilization
Respuesta biológica, nutricional y hematoinmune en juveniles Cherax quadricarinatus (Decapoda: Parastacidae) alimentados con mezcla probiótica
Objetivo: Evaluar indicadores biológicos, nutricionales y hematoinmunes en juveniles Cherax quadricarinatus que fueron cultivados y alimentados con una mezcla de probióticos. Materiales y métodos: Un diseño completamente aleatorizado (DCA) con seis tratamientos: 0 (control), 1×102 µL, 2×102 µL, 3×102 µL, 4×102 µL y 5×102 µL de mezcla de probióticos (Bacterol Shrimp Forte), con tres repeticiones cada una; se utilizaron 18 tanques experimentales de diametro 1.7 m y área de 2.26 m2, con una densidad de 20 juveniles (0.95±0.10 g y 7.78±0.77mm) por tanque durante 60 dÃas. Se midieron los parámetros biológicos (peso, longitud, aumento de peso, aumento de peso, tasa de crecimiento especÃfico, aumento de longitud, aumento de longitud y supervivencia), nutricionales (conversión alimenticia, eficiencia alimenticia y eficiencia proteica) y hematoinmune (total de hemocitos, hemocitos diferenciales, tasa fagocÃtica, superóxido dismutasa y estrés hipóxico). Resultados: Para los indicadores biológicos, los mejores resultados (p<0.05) se obtuvieron al utilizar 4×102 µL del probiótico (peso final: 9.11 g; longitud final: 68.95 mm; tasa de crecimiento especÃfico: 3.74). En cuanto a los parámetros nutricionales, los mejores resultados se obtuvieron con 3×102 µL (conversion alimenticia: 1.09, eficiencia alimenticia: 0.91 y eficiencia proteica: 2.61); aunque no hubo diferencias entre 3×102 y 4×102 µL. Para la respuesta hematoinmune, hubo diferencias (p <  0.05) para todos los indicadores en estudio, con un mejor desempeño para 4×102 µL de la mezcla de probióticos. Conclusiones: La mezcla de probióticos induce la respuesta hematoinmune, biológica y nutricional con la mejor respuesta para concentraciones de 3×102 µL y 4×102 µL
The RabGEF ALS2 is a hypoxia inducible target associated with the acquisition of aggressive traits in tumor cells
Indexación ScopusTumor hypoxia and the hypoxia inducible factor-1, HIF-1, play critical roles in cancer progression and metastasis. We previously showed that hypoxia activates the endosomal GTPase Rab5, leading to tumor cell migration and invasion, and that these events do not involve changes in Rab protein expression, suggesting the participation of intermediate activators. Here, we identified ALS2, a guanine nucleotide exchange factor that is upregulated in cancer, as responsible for increased Rab5-GTP loading, cell migration and metastasis in hypoxia. Specifically, hypoxia augmented ALS2 mRNA and protein levels, and these events involved HIF-1α-dependent transcription, as shown by RNAi, pharmacological inhibition, chromatin immunoprecipitation and bioinformatics analyses, which identified a functional HIF-1α-binding site in the proximal promoter region of ALS2. Moreover, ALS2 and Rab5 activity were elevated both in a model of endogenous HIF-1α stabilization (renal cell carcinoma) and by following expression of stable non-hydroxylatable HIF-1α. Strikingly, ALS2 upregulation in hypoxia was required for Rab5 activation, tumor cell migration and invasion, as well as experimental metastasis in C57BL/6 mice. Finally, immunohistochemical analyses in patient biopsies with renal cell carcinoma showed that elevated HIF-1α correlates with increased ALS2 expression. Hence, this study identifies ALS2 as a novel hypoxia-inducible gene associated with tumor progression and metastasis. © 2020, The Author(s).https://www-nature-com.recursosbiblioteca.unab.cl/articles/s41598-020-79270-
Balanços energéticos agropecuários: uma importante ferramenta como indicativo de sustentabilidade de agroecossistemas.
No Brasil, pouca atenção se tem dado à s formas e caminhos com que os fluxos energéticos se distribuem nos sistemas produtivos. Na agropecuária, a atenção tem sido voltada a novas fontes de energia (biomassa) ou em tecnologia alternativa, visando a racionalização do uso de energia fóssil ou elétrica. Entretanto, a agricultura tem se desenvolvido baseada fortemente na utilização intensiva de máquinas agrÃcolas, com conseqüente uso de combustÃveis fósseis. Um fator de estrangulamento muito forte no consumo energético geral tem sido a utilização massiva de fertilizantes derivados do petróleo nos agroecossistemas. Estudos de Balanços Energéticos visam determinar os pontos de estrangulamento energético fundamentando a busca por tecnologias poupadoras de energia, especialmente aquelas de origem fóssil (combustÃvel, fertilizante, agrotóxicos, energia despendida na fabricação das máquinas e implementos, etc.). No Brasil, a Região Sul, é onde se encontram vários trabalhos buscando uma agricultura mais auto-sustentável, do ponto de vista da utilização da energia. Em vista da possibilidade de eventuais futuras crises energéticas, o presente trabalho procura analisar o estado-da-arte dos estudos em Balanço Energético, no Brasil e no Mundo, como uma ferramenta de indicação da sustentabilidade dos sistemas agropecuários
Evolutionary and pulsational properties of white dwarf stars
Abridged. White dwarf stars are the final evolutionary stage of the vast
majority of stars, including our Sun. The study of white dwarfs has potential
applications to different fields of astrophysics. In particular, they can be
used as independent reliable cosmic clocks, and can also provide valuable
information about the fundamental parameters of a wide variety of stellar
populations, like our Galaxy and open and globular clusters. In addition, the
high densities and temperatures characterizing white dwarfs allow to use these
stars as cosmic laboratories for studying physical processes under extreme
conditions that cannot be achieved in terrestrial laboratories. They can be
used to constrain fundamental properties of elementary particles such as axions
and neutrinos, and to study problems related to the variation of fundamental
constants.
In this work, we review the essentials of the physics of white dwarf stars.
Special emphasis is placed on the physical processes that lead to the formation
of white dwarfs as well as on the different energy sources and processes
responsible for chemical abundance changes that occur along their evolution.
Moreover, in the course of their lives, white dwarfs cross different
pulsational instability strips. The existence of these instability strips
provides astronomers with an unique opportunity to peer into their internal
structure that would otherwise remain hidden from observers. We will show that
this allows to measure with unprecedented precision the stellar masses and to
infer their envelope thicknesses, to probe the core chemical stratification,
and to detect rotation rates and magnetic fields. Consequently, in this work,
we also review the pulsational properties of white dwarfs and the most recent
applications of white dwarf asteroseismology.Comment: 85 pages, 28 figures. To be published in The Astronomy and
Astrophysics Revie
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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