Colonial Organization of Mine Labour in Charcas 1 (Present-Day Bolivia) and Its Consequences 2 (Sixteenth to the Seventeenth Centuries)

This article analyses the changes in the organization of labour during the sixteenth and seventeenth centuries in colonial Charcas, present-day Bolivia, focusing on the role that different colonial authorities played in this process and its consequences. The Spanish took advantage of the pre-Hispanic organization of labour from the beginning of their conquest. However, in a colonial context, labour relations changed significantly, and the architect of those alterations was Viceroy Francisco de Toledo. We examine the transformations in mine labour carried out by the Spanish colonial polity; these had a significant effect not only on mining, but also on all labour relations in the southern colonial Andes.Fil: Gil Montero, Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Geografía, Historia y Ciencias Sociales. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto de Geografía, Historia y Ciencias Sociales; ArgentinaFil: Zagalsky, Paula Cecilia. Universidad Nacional de Jujuy; Argentina. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

El problema termoelástico de conducción de calor entre sólidos en contacto mediante ecuaciones integrales de contorno

Se presenta una formulación basada en integrales de contorno para el análisis de problemas de contacto sin fricción en termoelasticidad bidimensional. Como modelo de resistencia térmica en la zona de contacto se consideran funciones decrecientes con la presión de contacto. Las ecuaciones del problema de conducción estacionaria de calor y las ecuaciones elásticas, que están acopladas a través de la resistencia térmica, se resuelven independientemente dentro de un proceso iterativo. La convergencia se alcanza cuando se obtiene una solución del problema elástico con deformaciones térmicas sin tracciones en la zona de contacto y con una ley de compresiones que implique valores de la resistencia concordantes con los supuestos en las ecuaciones térmicas, las cuales se resuelven en primer lugar. La formulación numérica propuesta permite detectar la posible separación de los cuerpos cuando el flujo de calor circula hacia el sólido de mayor distorsionabilidad termoelástica. El artículo incluye dos ejemplos que ilustran la aplicabilidad del procedimiento expuesto.A boundary integral formulation for two dimensional thermoelastic contact problems without friction is presented. The local thermal resistance at the contact zone is modelied as a given decreasing function of the contact pressure. The stationary heat conduction equations and the elastic equations, which are coupled through the thermal resistance, are solved independently in the scope of an iterative process. The elastic problem involving thermal loading is solved, and convergence is reached when the obtained contact pressure leads to a thermal resistance in agreement with the one assumed in the thermal problem, which was formerly solved. The present formulation also accounts for the possibility of separation in the initial contact zone when the heat flows towards the body of greatest distorsivity. The paper includes two examples illustrating the reliability of the method.Peer Reviewe

Nuestra experiencia con la enfermedad de Freiberg

Analizamos una serie de 34 pacientes, 9 varones y 25 mujeres, con enfermedad de Freiberg, detallando su localización y grado evolutivo en el momento del diagnóstico. Clínicamente la severidad del cuadro fue muy variable, y con frecuencia discordante con la imagen radiológica. Tan solo en 5 pacientes fue necesario el tratamiento quirúrgico. No se pudo detectar un factor etiológico claro y único, existiendo casos con y sin antecedentes traumáticos. Se describe la evolución radiológica de esta enfermedad. La RMN permite de forma precoz, detectar las anomalías óseas en las fases más iniciales.We analyze a series of 34 patients, 9 males and 25 females, with Freiberg's disease, detailing their location and severity at moment of the diagnosis. Clinically the severity of disease was variable, and frequently discordant with the radiological image. Only in 5 patients was necessary the surgical treatment. There was no etiologic factor clearly found in any of the cases, with and without traumatic precedents. We describe the radiological pattern of this disease. The MRI permits at early stage detection of bone anomalies

The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide

The chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharide of pathogenic Edwardsiella tarda strain EIB 202 were studied for the first time. The complete gene assignment for all LPS core biosynthesis gene functions was acquired. The complete structure of core oligosaccharide was investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry MSn, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. The following structure of the undecasaccharide was established: The heterogeneous appearance of the core oligosaccharide structure was due to the partial lack of β-d-Galp and the replacement of α-d-GlcpNAcGly by α-d-GlcpNGly. The glycine location was identified by mass spectrometry

Millisecond radiative recombination in poly(phenylene vinylene)-based light-emitting diodes from transient electroluminescence

The current and electroluminescence transient responses of standard poly(phenylene vinylene)-based light-emitting devices have been investigated. The electroluminescence time response is longer (milliseconds scale) than the current switch-off time by more than one order of magnitude, in the case of small area devices (<0.1 cm2). For large area devices ( ∼ 6 cm2) the electroluminescence decay time decreases from 1.45 ms to  ∼ 100 μs with increasing bias voltage. The fast current decay limits the electroluminescence decay at higher voltages. Several approaches are discussed to interpret the observed slow decrease of electroluminescence after turning off the bias. One relies upon the Langevin-type bimolecular recombination kinetics which is governed by the minority carriers (electrons), and another focuses on the slow release of trapped electrons as possible explanations. Additionally, we show that the device current density is mainly determined by the transport of the fastest carriers (holes)[email protected]

Biometrical Analysis of the Anterior Communicating Artery and the Anterior Cerebral Artery in the Precommunicating Segment of the Cerebral Arterial Circle

Indexación: ScieloLa conformación del círculo arterial cerebral tiene relevancia en la clínica neuroquirúrgica por la relación compleja que presentan las arterias que lo originan y su gran variabilidad. Debido a la alta frecuencia con que se observan aneurismas en las arteria comunicante anterior y en el segmento precomunicante (A1) de la arteria cerebral anterior se efectuó un análisis biométrico de ellas. El trabajo se realizó en 36 cerebros frescos procedentes de especímenes cuyos datos bioantropológicos estaban registrados. El calibre de la arteria comunicante anterior fue de 1.68 mm y la longitud, en promedio, de 2.50 mm. En el lado derecho el segmento A1 de la arteria cerebral anterior tenía una longitud de 12.91mm y un calibre de 2.39 mm. En el lado izquierdo, la longitud de este segmento fue de 12.77 mm y presentó un calibre de 2.46mm. En un 29% de las muestras analizadas, se presentaron arterias comunicantes dobles, con una longitud de 2.92 mm y un calibre de 0.95 mm. Se observó variabilidad en los componentes que constituyen el círculo arterial cerebral, cuando se consideran variables como lado, sexo e índice cefálico. PALABRAS CLAVE: Arteria comunicante anterior; Arteria cerebral anterior; Círculo arterial del cerebro; Índice cefálico.SUMMARY: The conformation of the cerebral arterial circle has relevance in the clinical neurosurgery for the complex relate that present the arteries that originate it and its great variability. Due to the high frequency with that aneurysms are observed in the anterior communicant artery and the anterior cerebral artery in the precommunicating segment (A1), we have decided to make an analysis biometrical in them. The work had done in 36 available fresh brains in the laboratories and they come from specimens whose data bioanthropological were registered. The caliber of the anterior communicating artery corresponds to 1.68 mm and the longitude to 2.50 mm. The segment A1 of the anterior cerebral artery it corresponds to a longitude of 12.91mm and it presents a caliber of 2.39 mm in the right side. In the left side the longitude of this segment is of 12.77 mm and it presents a caliber of 2.46. In 29% of the analyzed samples, they register double communicating arteries, with a longitude of 2.92 mm and a caliber of 0.95 mm. Variability of the components is observed that they constitute the cerebral arterial circle when is considered: side, sex and cephalic index KEY WORDS: Anterior communicating artery; Anterior cerebral artery; Cerebral arterial circle; Cephalix index

Biometrical Characteristics of Anterior Choroidal Artery in its Cisternal Segment

Indexación: Web of Science; ScieloLas implicancias clínicas que tienen los procesos oclusivos de la Arteria Coroidea Anterior (AChA), son de considerable importancia y nos han motivado para efectuar su análisis biométrico incorporando algunos otros parámetros. Para su ejecución, se utilizaron cerebros inyectados con látex coloreado de rojo fijados en solución de formol, provenientes del Servicio Médico Legal, Santiago.Para su observación, se usó lupa luminiscente 4 X y las mediciones efectuadas con Caliper Mitutoyo Digital. Esta arteria se originó de la Carótida Interna (ACI) en un 83,3 % y en un 16,7 % de la Arteria Comunicante Posterior (ACoP ). El calibre medio observado en su origen fue de 0,68 ± 0,31 mm; en el tercio medio de 0,60 ± 0,21 mm; en el punto de entrada en el plexo coroideo de 0,48 ± 0,23 mm. La longitud media desde el origen de la AChA al plexo coroideo fue de 28,67 ±6,33 mm; la distancia media desde su origen al de la ACoP fue de 6,97 ± 4,89 mm. El número promedio de ramas perforantes registradas fue de 6. Nuestros resultados pueden ser una contribución a considerar en la clínica.SUMMARY:The clinical implications of occlusive processes in the anterior choroidal artery (AChA) are of considerable importance and have motivated us to perform a biometrical analysis of the afore mentioned artery including new biometric parameters (measurements). This study was perfomed on vascularized brains that were both fixed with for formalin solution and injected whith red tinted latex and brains that were not fixed with formalin solution, which were obtained from the Medical Legal Service, Santiago. They were observed using a luminescent 4 X magnifying glass and the measurements perfomed using a Mitutoyo Digital Caliper. This artery originated from the internal carotid artery (ICA) in 83.3 % of the cases observed, and in 16.7 % it originated from the posterior communicating artery ( PCoA). The mean caliber (diameter) of the artery was 0.68 ± 0.31 mm at the point of origin; the middle third was 0.60 mm ± 0.21 mm; at the point of entry into the choroidal plexus it was 0.48 mm ± 0.23 mm. The mean length from its origin at the AChA to the choroidal plexus was 28.67 mm ± 6.33 mm; the mean distance from its origin at the PCoAwas 6.97mm± 4.89 mm. The number of perforating branches of the AChA was 6. Our results can be considered a clinical contribution. KEY WORDS : Anterior choroidal artery ; Biometry; Cephalix index; Internal carotid artery.http://ref.scielo.org/26fk9

Phospho-kinase profile of triple negative breast cancer and androgen receptor signaling

BACKGROUND: The androgen receptor (AR) plays a central role in the oncogenesis of different tumors, as is the case in prostate cancer. In triple negative breast cancer (TNBC) a gene expression classification has described different subgroups including a luminal androgen subtype. The AR can be controlled by several mechanisms like the activation of membrane tyrosine kinases and downstream signaling pathways. However little is known in TNBC about how the AR is modulated by these mechanisms and the potential therapeutic strategists to inhibit its expression. METHODS: We used human samples to evaluate the expression of AR by western-blot and phospho-proteomic kinase arrays that recognize membrane tyrosine kinase receptors and downstream mediators. Western-blots in human cell lines were carried out to analyze the expression and activation of individual proteins. Drugs against these kinases in different conditions were used to measure the expression of the androgen receptor. PCR experiments were performed to assess changes in the AR gene after therapeutic modulation of these pathways. RESULTS: AR is present in a subset of TNBC and its expression correlates with activated membrane receptor kinases-EGFR and PDGFRβ in human samples and cell lines. Inhibition of the PI3K/mTOR pathway in TNBC cell lines decreased notably the expression of the AR. Concomitant administration of the anti-androgen bicalutamide with the EGFR, PDGFRβ and Erk1/2 inhibitors, decreased the amount of AR compared to each agent given alone, and had an additive anti-proliferative effect. Administration of dihydrotestosterone augmented the expression of AR that was not modified by the inhibition of the PI3K/mTOR or Erk1/2 pathways. AR expression was posttranscriptionally regulated by PI3K or Erk1/2 inhibition. CONCLUSION: Our results describe the expression of the AR in TNBC as a druggable target and further suggest the combination of bicalutamide with inhibitors of EGFR, PDGFRβ or Erk1/2 for future development

Antitumor activity of the novel multi-kinase inhibitor EC-70124 in triple negative breast cancer

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Disseminated triple negative breast cancer (TNBC) is an incurable disease with limited therapeutic options beyond chemotherapy. Therefore, identification of druggable vulnerabilities is an important aim. Protein kinases play a central role in cancer and particularly in TNBC. They are involved in many oncogenic functions including migration, proliferation, genetic stability or maintenance of stem-cell like properties. In this article we describe a novel multi-kinase inhibitor with antitumor activity in this cancer subtype. EC-70124 is a hybrid indolocarbazole analog obtained by combinatorial biosynthesis of Rebeccamycin and Staurosporine genes that showed antiproliferative effect and in vivo antitumoral activity. Biochemical experiments demonstrated the inhibition of the PI3K/mTOR and JAK/STAT pathways. EC-70124 mediated DNA damage leading to cell cycle arrest at the G2/M phase. Pathway analyses identified several deregulated functions including cell proliferation, migration, DNA damage, regulation of stem cell differentiation and reversion of the epithelial-mesenchymal transition (EMT) phenotype, among others. Combination studies showed a synergistic interaction of EC-70124 with docetaxel, and an enhanced activity in vivo. Furthermore, EC-70124 had a good pharmacokinetic profile. In conclusion these experiments demonstrate the antitumor activity of EC-70124 in TNBC paving the way for the future clinical development of this drug alone or in combination with chemotherapy.Ministry of Economy and Competitiveness of Spain (BFU2012-39151 and RD12/0036/0003 to AP), and the AECC (to AP). Instituto de Salud Carlos III (PI13/01444) ACEPAIN and CRIS Cancer Foundation (to AO). JCM is a recipient of a Miguel Servet fellowship program (CP12/03073).Peer Reviewe

Polar flagella glycosylation in Aeromonas: genomic characterization and involvement of a specific glycosyltransferase (Fgi-1) in heterogeneous flagella glycosylation

Polar flagella from mesophilic Aeromonas strains have previously been shown to be modified with a range of glycans. Mass spectrometry studies of purified polar flagellins suggested the glycan typically includes a putative pseudaminic acid like derivative; while some strains are modified with this single monosaccharide, others modified with a heterologous glycan. In the current study, we demonstrate that genes involved in polar flagella glycosylation are clustered in highly polymorphic genomic islands flanked by pseudaminic acid biosynthetic genes (pse). Bioinformatic analysis of mesophilic Aeromonas genomes identified three types of polar flagella glycosylation islands (FGIs), denoted Group I, II and III. FGI Groups I and III are small genomic islands present in Aeromonas strains with flagellins modified with a single monosaccharide pseudaminic acid derivative. Group II were large genomic islands, present in strains found to modify polar flagellins with heterogeneous glycan moieties. Group II, in addition to pse genes, contained numerous glycosyltransferases and other biosynthetic enzymes. All Group II strains shared a common glycosyltransferase downstream of luxC that we named flagella glycosylation island 1, fgi-1, in A. piscicola AH-3. We demonstrate that Fgi-1 transfers the first sugar of the heterogeneous glycan to the pseudaminic acid derivative linked to polar flagellins and could be used as marker for polysaccharidic glycosylation of Aeromonas polar flagella