El comercio de antigüedades en Arica durante el periodo republicano peruano (1824-1880): El rol de la comunidad británica como un subproducto del imperio informal

The port of Arica was part of the global network of exchanges established by the North Atlantic powers in their process of global colonial expansion during the 19th century, which in Latin America sought to position them as new hegemonic forces in the region, replacing Spain. Arica was constituted as a node in this network, participating in it as a zone of commercial exchanges and intercultural contacts. One dimension of these exchanges was the trade in antiquities, mainly archaeological objects associated with pre-Hispanic cemeteries, which were intensively exploited from the beginning of the Hispanic colonial period. In this way, Arica functioned as a repository of archaeological specimens, where a diversity of agents interacted, within which the resident British community played a leading role over the local élite.El puerto de Arica fue parte de la red global de intercambios establecida por las potencias noratlánticas en su proceso de expansión colonial global durante el siglo XIX, este en América Latina buscó posicionarlas como nuevas fuerzas hegemónicas en la región sustituyendo a España. Arica se constituyó como un nodo de esta red, participando en ella como una zona de intercambios comerciales y contactos interculturales. Una dimensión de estos intercambios fue el comercio de antigüedades, principalmente objetos arqueológicos asociados a cementerios prehispánicos, los que fueron explotados intensivamente desde inicios del periodo colonial hispano. De esta forma, Arica funcionó como un repositorio de especímenes arqueológicos, donde interactuaron una diversidad de agentes, dentro de los cuales, la comunidad británica residente cumplió un rol principal por sobre la élite local

Glutamate 83 and arginine 85 of helix H3 bend are key residues for FtsZ polymerization, GTPase activity and cellular viability of Escherichia coli: lateral mutations affect FtsZ polymerization and E. coli viability

BACKGROUND: FtsZ is an essential cell division protein, which localizes at the middle of the bacterial cell to mediate cytokinesis. In vitro, FtsZ polymerizes and induces GTPase activity through longitudinal interactions to form the protofilaments, whilst lateral interactions result within formation of bundles. The interactions that participate in the protofilaments are similar to its eukaryotic homologue tubulin and are well characterized; however, lateral interactions between the inter protofilaments are less defined. FtsZ forms double protofilaments in vitro, though the key elements on the interface of the inter-protofilaments remain unclear as well as the structures involved in the lateral interactions in vivo and in vitro. In this study, we demonstrate that the highly conserved negative charge of glutamate 83 and the positive charge of arginine 85 located in the helix H3 bend of FtsZ are required for in vitro FtsZ lateral and longitudinal interactions, respectively and for in vivo cell division. RESULTS: The effect of mutation on the widely conserved glutamate-83 and arginine-85 residues located in the helix H3 (present in most of the tubulin family) was evaluated by in vitro and in situ experiments. The morphology of the cells expressing Escherichia coli FtsZ (E83Q) mutant at 42°C formed filamented cells while those expressing FtsZ(R85Q) formed shorter filamented cells. In situ immunofluorescence experiments showed that the FtsZ(E83Q) mutant formed rings within the filamented cells whereas those formed by the FtsZ(R85Q) mutant were less defined. The expression of the mutant proteins diminished cell viability as follows: wild type > E83Q > R85Q. In vitro, both, R85Q and E83Q reduced the rate of FtsZ polymerization (WT > E83Q >> R85Q) and GTPase activity (WT > E83Q >> R85Q). R85Q protein polymerized into shorter filaments compared to WT and E83Q, with a GTPase lag period that was inversely proportional to the protein concentration. In the presence of ZipA, R85Q GTPase activity increased two fold, but no bundles were formed suggesting that lateral interactions were affected. CONCLUSIONS: We found that glutamate 83 and arginine 85 located in the bend of helix H3 at the lateral face are required for the protofilament lateral interaction and also affects the inter-protofilament lateral interactions that ultimately play a role in the functional localization of the FtsZ ring at the cell division site

A model for the Escherichia coli FtsB/FtsL/FtsQ cell division complex

<p>Abstract</p> <p>Background</p> <p>Bacterial division is produced by the formation of a macromolecular complex in the middle of the cell, called the <it>divisome</it>, formed by more than 10 proteins. This process can be divided into two steps, in which the first is the polymerization of FtsZ to form the Z ring in the cytoplasm, and then the sequential addition of FtsA/ZipA to anchor the ring at the cytoplasmic membrane, a stage completed by FtsEX and FtsK. In the second step, the formation of the peptidoglycan synthesis machinery in the periplasm takes place, followed by cell division. The proteins involved in connecting both steps in cell division are FtsQ, FtsB and FtsL, and their interaction is a crucial and conserved event in the division of different bacteria. These components are small bitopic membrane proteins, and their specific function seems to be mainly structural. The purpose of this study was to obtain a structural model of the periplasmic part of the FtsB/FtsL/FtsQ complex, using bioinformatics tools and experimental data reported in the literature.</p> <p>Results</p> <p>Two oligomeric models for the periplasmic region of the FtsB/FtsL/FtsQ <it>E. coli </it>complex were obtained from bioinformatics analysis. The FtsB/FtsL subcomplex was modelled as a coiled-coil based on sequence information and several stoichiometric possibilities. The crystallographic structure of FtsQ was added to this complex, through protein-protein docking. Two final structurally-stable models, one trimeric and one hexameric, were obtained. The nature of the protein-protein contacts was energetically favourable in both models and the overall structures were in agreement with the experimental evidence reported.</p> <p>Conclusions</p> <p>The two models obtained for the FtsB/FtsL/FtsQ complex were stable and thus compatible with the <it>in vivo </it>periplasmic complex structure. Although the hexameric model 2:2:2 has features that indicate that this is the most plausible structure, the ternary complex 1:1:1 cannot be discarded. Both models could be further stabilized by the binding of the other proteins of the <it>divisome</it>. The bioinformatics modelling of this kind of protein complex, whose function is mainly structural, provide useful information. Experimental results should confirm or reject these models and provide new data for future bioinformatics studies to refine the models.</p

Effect of water application on wine quality and yield in ‘Carménère’ under the presence of a shallow water table in central Chile

Chile is the world’s leading producer of ‘Carménère’ (Vitis vinifera L.), which in turn is an important variety in Chile, where vineyards are typically grown under irrigated conditions and a large percentage are located in valleys with similar water table levels to those of the study area. Different irrigation management strategies have been used to improve wine quality, such as water stress and deficit irrigations, but the presence of a water table has not been considered in extant literature. This study analyzes the effects of the irrigation regime on grape yield and wine quality when a shallow water table is located between 1.5 to 2.2 m depth during the irrigation season. Five applied water treatments: 0%, 20%, 40%, 75%, and 100% of estimated vineyard evapotranspiration (ETc) were applied in an own-rooted ‘Carménère’ vineyard located in the Peumo Valley (Chile) during three consecutive seasons (2004-2005 to 2006-2007). Applying 1400 to 9400 m3 ha-1 per season (100% ETc) had no substantial effect on the measured quality parameters, although grape production in the treatment without irrigation (0% ETc) was significantly reduced. Applying water at 20% to 40% ETc produced high yield (13 to 16 t ha-1), double the historical mean production, and high quality wine with the presence of a water table close to the bottom of the root zone.Universidad de Concepción, ChileBMBF/CONICYT 231-2010Water Resources Center for Agriculture and MiningCONICYT/FONDAP/1513001

Nivel de conocimiento y practica del Examen de Papanicolaou en las mujeres de 25 a 64 años que asistieron al Centro de Salud Vista Alegre. Ayacucho 2017

OBJETIVO: Determinar la relación entre el conocimiento y práctica del examen de Papanicolaou en mujeres de 25 a 64 arios que asisten al Centro de Salud Vista Alegre Ayacucho 2017. MÉTODOS: Es un estudio observacional, correlacional, analítico, prospectivo, cuantitativo y transversal en él se evaluó a mujeres de 25 a 64 arios que asisten al Centro de Salud Vista Alegre Ayacucho 2017. Se utilizó encuestas estructuradas y la validez del instrumentó se realizó con Cronbach para la variable conocimiento (alfa = 0.922) y para la variable practica (alfa = 0.553). La población son de 45 mujeres y la muestra fue de 40 mujeres de 25 a 64 años. La información que se obtuvo se tabulo para el procesamiento estadístico de los datos en el programa de Excel, SPSS y Rho Spearman. Se utilizó la estadística descriptiva como: frecuencia, porcentaje, media aritmética y desviación estándar. La estadística inferencial determinó la relación existente entre variables a través de la prueba Chi-cuadrado con un nivel de significancia < 0,05. RESULTADOS: El 30% de las mujeres de 25 a 64 años encuestadas se encuentran entre los 26-32 arios. Del total de mujeres encuestadas, el 50% conocen que el Papanicolaou se realiza para la detección del cáncer del cuello uterino; el 35% sabe que el Papanicolaou sirve para detectar cáncer uterino; el 47.5% refieren que deben realizarse el Papanicolaou las mujeres con inicio de relaciones sexuales; el 42.5% sabe cuándo debe realizarse el Papanicolaou que es cuando inicia sus relaciones sexuales; el 42.5% piensan que el Papanicolaou sirve para evitar flujos vaginales; de igual manera; el 55.5% presentaron un nivel de conocimiento alto con respecto al Papanicolaou; el 90% mostraron una práctica adecuada frente al examen del Papanicolaou; el 50% de mujeres no se realiza el Papanicolaou por vergüenza; el 60% de las parejas si están de acuerdo para que las mujeres se realicen el Papanicolaou y el 65% de las mujeres practican realizarse el examen de Papanicolaou. Así mismo se encontró que existe relación estadísticamente significativa entre el nivel de conocimiento alto y la práctica adecuada frente al examen de Papanicolaou (p < 0,05). CONCLUSIONES: Que las mujeres de 25 a 64 arios que asistieron al Centro de Salud Vista Alegre, presentan un nivel de conocimiento alto y una práctica adecuada frente al examen del Papanicolaou.Tesis de segunda especialida

Surface energy balance model of transpiration from variable canopy cover and evaporation from residue-covered or bare soil systems: Model evaluation

A surface energy balance model (SEB) was extended by Lagos et al. Irrig Sci 28:51–64 (2009) to estimate evapotranspiration (ET) from variable canopy cover and evaporation from residue-covered or bare soil systems. The model estimates latent, sensible, and soil heat fluxes and provides a method to partition evapotranspiration into soil/residue evaporation and plant transpiration. The objective of this work was to perform a sensitivity analysis of model parameters and evaluate the performance of the proposed model to estimate ET during the growing and non-growing season of maize (Zea Mays L.) and soybeans (Glycine max) in eastern Nebraska. Results were compared with measured data from three eddy covariance systems under irrigated and rain-fed conditions. Sensitivity analysis of model parameters showed that simulated ET was most sensitive to changes in surface canopy resistance, soil surface resistance, and residue surface resistance. Comparison between hourly estimated ET and measurements made in soybean and maize fields provided support for the validity of the surface energy balance model. For growing season’s estimates, Nash–Sutcliffe coefficients ranged from 0.81 to 0.92 and the root mean square error (RMSE) varied from 33.0 to 48.3 W m–2. After canopy closure (i.e., after leaf area index (LAI = 4) until harvest), Nash–Sutcliffe coefficients ranged from 0.86 to 0.95 and RMSE varied from 22.6 to 40.5 W m–2. Performance prior to canopy closure was less accurate. Overall, the evaluation of the SEB model during this study was satisfactory

Surface energy balance model of transpiration from variable canopy cover and evaporation from residue-covered or bare soil systems: Model evaluation

A surface energy balance model (SEB) was extended by Lagos et al. Irrig Sci 28:51–64 (2009) to estimate evapotranspiration (ET) from variable canopy cover and evaporation from residue-covered or bare soil systems. The model estimates latent, sensible, and soil heat fluxes and provides a method to partition evapotranspiration into soil/residue evaporation and plant transpiration. The objective of this work was to perform a sensitivity analysis of model parameters and evaluate the performance of the proposed model to estimate ET during the growing and non-growing season of maize (Zea Mays L.) and soybeans (Glycine max) in eastern Nebraska. Results were compared with measured data from three eddy covariance systems under irrigated and rain-fed conditions. Sensitivity analysis of model parameters showed that simulated ET was most sensitive to changes in surface canopy resistance, soil surface resistance, and residue surface resistance. Comparison between hourly estimated ET and measurements made in soybean and maize fields provided support for the validity of the surface energy balance model. For growing season’s estimates, Nash–Sutcliffe coefficients ranged from 0.81 to 0.92 and the root mean square error (RMSE) varied from 33.0 to 48.3 W m–2. After canopy closure (i.e., after leaf area index (LAI = 4) until harvest), Nash–Sutcliffe coefficients ranged from 0.86 to 0.95 and RMSE varied from 22.6 to 40.5 W m–2. Performance prior to canopy closure was less accurate. Overall, the evaluation of the SEB model during this study was satisfactory

Use of machine learning to improve the robustness of spatial estimation of evapotranspiration

Estimation of the crop water requirement is critical in the optimization of the agricultural production process, due to that yield and costs are directly affected by this estimation. Nowadays, remote sensing is a useful tool for estimating Evapotranspiration (ET), since it is possible to map their spatial and temporal variability. ET models using satellite images have been developed in the last decades, using in most cases the surface energy balance which has generated good ET representation in different study sites. One of these models is METRIC (Mapping EvapoTranspiration at high Resolution using Internalized Calibration), which estimates ET using mainly data from Landsat 7 and 5 images, and a physical-empirical basis to solve the surface energy balance. The main drawback of the METRIC model is the low robustness in the selection of two parameters called anchor pixels. Even though the rules to select anchor pixels are standardized, the procedure requires a user to choose the area where these pixels will be selected. In this sense, ET estimation is highly sensible to this selection, producing important differences when different anchor pixels are selected. In this study, a machine learning method is implemented through the GEOBIA (Geographic Object Based Image Analysis) approach for the identification of anchor objects, changing the focus from the pixels to the objects. Image segmentation and classification processes are used for an adequate selection of anchor objects, considering spectral and contextual information. The main contribution of this work proves that it is not necessary to choose an area to select the anchor parameters, improving the numerical stability of the model METRIC and increasing the robustness of the ET estimation. Results were validated by comparing the original selection of anchor pixels, as well as in-situ ET estimation using data obtained from Surface Renewal Stations, in sugar beat crop

Toward reduction of artifacts in fused images

Most fusion satellite image methodologies at pixel-level introduce false spatial details, i.e.artifacts, in the resulting fusedimages. In many cases, these artifacts appears because image fusion methods do not consider the differences in roughness or textural characteristics between different land covers. They only consider the digital values associated with single pixels. This effect increases as the spatial resolution image increases. To minimize this problem, we propose a new paradigm based on local measurements of the fractal dimension (FD). Fractal dimension maps (FDMs) are generated for each of the source images (panchromatic and each band of the multi-spectral images) with the box-counting algorithm and by applying a windowing process. The average of source image FDMs, previously indexed between 0 and 1, has been used for discrimination of different land covers present in satellite images. This paradigm has been applied through the fusion methodology based on the discrete wavelet transform (DWT), using the à trous algorithm (WAT). Two different scenes registered by optical sensors on board FORMOSAT-2 and IKONOS satellites were used to study the behaviour of the proposed methodology. The implementation of this approach, using the WAT method, allows adapting the fusion process to the roughness and shape of the regions present in the image to be fused. This improves the quality of the fusedimages and their classification results when compared with the original WAT metho

May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk