Search

In the manufacturing industry, it is important to reduce machining deviations as soon as possible to avoid the cost associated with reworks. The definition of mathematical models that predict future failures in the diagnosis of combustion engines associated with errors in machining is a way that helps to save time and money in a process. This paper proposes the analysis and establishment of correlations between the deviations of the machining in cylinder heads and the rejections of an engine cold testing in an automotive manufacturing company. To determine the relationships, a sample of heads and engines was measured in two months, and statistical models were established using inferential statistics. It was possible to establish 77 statistical models that allow predicting which machining of the cylinder heads are contributing to the rejects and therefore adjust the corresponding tools. Due to a large amount of data from the results of the 77 models, this article shows only one model which is one of the most representatives. Using this statistical model, it was possible to know which characteristic of the tool should be adjusted in addition it was also possible to know that the test limits for oil pressure have to be adjusted in the engine cold testing. [ABSTRACT FROM AUTHOR]

The Pampas is among the major agricultural regions in the world; a large proportion of Argentina crop production is originated in this region. The exportation of grain and oil crop represents more than 40% of the total national exportations. Impact of future climate on wheat, maize and soybean yield and crop adaptation in the Pampas region (60 million hectares) are assessed using climatic inputs generated by CCSM4 climate model (National Center for Atmospheric Research, US). Projections show an increase in the seasonal means maximum and minimum temperature for both the near (2015–2039) and the far (2075–2099) future, as well as a seasonal annual precipitation increase in the near future and a significant increase in the far future with extreme emissions scenarios. In the near future the crop model projects a reduction in wheat yield, an increase in maize yield and a significant increment in soybean yield compared to the regional baseline for moderate (RCP4.5) and extreme (RCP8.5) emissions. In the far future the projection shows a decrease in wheat yield in the RCP4.5 scenario and an increase in the RCP8.5 scenario, maize and soybean shown a yield increase in both scenarios. Adaptation strategies for the near and far future are proposed for wheat and maize that result in up to 45% yield increases. Adaptation strategies are not proposed for soybean because yield increases were predicted in all scenarios and horizons. [ABSTRACT FROM AUTHOR]

Microbial expansins act on plant cell walls similarly to plant expansins, albeit their loosening activity levels are tenfold lesser compared to plant expansins. We report the characterization of an expansin-like gene from the plant pathogen Pectobacterium carotovorum, named exl1. PcExl1 is an acidic protein that binds cellulose (Avicel), and weakens filter paper. The acidic nature of PcExl1 confers different binding properties when compared to Bacillus subtilis BsEXLX1, which is a basic protein. PcExl1 binding to wheat cell wall increased when acidic components were depleted, reaching a similar level to the binding to Avicel, indicating that cellulose is the target of PcExl1. [ABSTRACT FROM AUTHOR]

This paper identifies two sources of uncertainties in model projections of temperature and precipitation: internal and inter-model variability. Eight models of WCRP-CMIP3 and WCRP-CMIP5 were compared to identify improvements in the reliability of projections from new generation models. While no significant differences are observed between both datasets, some improvements were found in the new generation models. For example, in summer CMIP5 inter-model variability of temperature was lower over northeastern Argentina, Paraguay and northern Brazil, in the last decades of the 21st century. Reliability of temperature projections from both sets of models is high, with signal to noise ratio greater than 1 over most of the study region. Although no major differences were observed in both precipitation datasets, CMIP5 inter-model variability was lower over northern and eastern Brazil in summer (especially at the end of the 21st century). Reliability of precipitation projections was low in both datasets. However, the signal to noise ratio in new generation models was close to 1, and even greater than 1 over eastern Argentina, Uruguay and southern Brazil in some seasons. [ABSTRACT FROM AUTHOR]

This paper evaluates a present climate simulation over southern South America performed with the Meteorological Research Institute/Japanese Meteorological Agency (MRI/JMA) high resolution global model. Main patterns of low and upper-level atmospheric circulation were analysed in a 25-year simulation as well as climate means, interannual variability, trends and bias of temperature and precipitation. The model is able to reproduce the main atmospheric circulation patterns and mean surface variables, although some deficiencies were found such as an overestimation of temperature over central Argentina in most of seasons, an overestimation of austral winter precipitation over northeastern and central Argentina, an underestimation of precipitation in all the seasons over southeast of Brazil, an underestimation of the amplitude of the annual cycle temperature in some regions and an overestimation of the amplitude of the annual cycle of precipitation over mountainous areas. Model interannual variability was also assessed. In general, temperature variability is overestimated, whereas precipitation is underestimated. The spatial structure of the year-to-year variability of precipitation is correctly simulated by the model, although some patterns were misplaced. Most of regions present a cold seasonal bias reaching values of − 2 °C in some regions. It was found that precipitation biases are between 3 and − 1 mm day−1. In some regions and seasons observed and simulated temperature trends coincide, as in austral summer or spring, where the model and the observations show positive trends in most of regions. However, there is no agreement between observed and simulated precipitation trends in almost all the regions and seasons. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Winter orographic precipitation over the Andes between 30° and 37°S is examined using precipitation gauges in the mountains and adjacent lowlands. Because of the limited number of precipitation gauges, this paper focuses on the large-scale variation in cross-barrier precipitation and does not take into account the fine ridge-valley scale. The maximum amount of precipitation was observed on the windward slope of the mountain range below the crest, which was twice that observed on the low-windward side between 32.5° and 34°S. Toward the east of the crest, precipitation amounts drop sharply, generating a strong cross-barrier gradient. The rain shadow effect is greater in the north (32°-34.5°S) than in the south (35°-36.5°S) of the low-lee side, which is probably due to more baroclinic activity in southernmost latitudes and a southward decrease in the height of the Andes enabling more spillover precipitation. The effect of the Andes on winter precipitation is so marked that it modifies the precipitation regimes in the adjacent windward and leeward lowlands north of 35°S. Based on the fact that ~75%% of the wintertime precipitation accumulated in the fourth quartile, through four or five heavy events on average, the synoptic-scale patterns of the heavy (into fourth quartile) orographic precipitation events were identified. Heavy events are strongly related to strong water vapor transport from the Pacific Ocean in the pre-cold-front environment of extratropical cyclones, which would have the form of atmospheric rivers as depicted in the reanalysis and rawinsonde data. The composite fields revealed a marked difference between two subgroups of heavy precipitation events. The extreme (100th-95th percentiles) events are associated with deeper cyclones than those for intense (95th-75th percentiles) events. These deeper cyclones lead to much stronger plumes of water vapor content and cross-barrier moisture flux against the high Andes, resulting in heavier orographic precipitation for extreme events. In addition, regional airflow characteristics suggest that the low-level flow is typically blocked and diverted poleward in the form of an along-barrier jet. On the lee side, downslope flow dominates during heavy events, producing prominent rain shadow effects as denoted by the domain of downslope winds extending to low-leeward side (i.e., zonda wind). [ABSTRACT FROM AUTHOR]

We present an analysis of climate change over southern South America as simulated by a regional climate model. The regional model MM5 was nested within time-slice global atmospheric model experiments conducted by the HadAM3H model. The simulations cover a 10-year period representing present-day climate (1981–1990) and two future scenarios for the SRESA2 and B2 emission scenarios for the period 2081–2090. There are a few quantitative differences between the two regional scenarios. The simulated changes are larger for the A2 than the B2 scenario, although with few qualitative differences. For the two regional scenarios, the warming in southern Brazil, Paraguay, Bolivia and northeastern Argentina is particularly large in spring. Over the western coast of South America both scenarios project a general decrease in precipitation. Both the A2 and B2 simulations show a general increase in precipitation in northern and central Argentina especially in summer and fall and a general decrease in precipitation in winter and spring. In fall the simulations agree on a general decrease in precipitation in southern Brazil. This reflects changes in the atmospheric circulation during winter and spring. Changes in mean sea level pressure show a cell of increasing pressure centered somewhere in the southern Atlantic Ocean and southern Pacific Ocean, mainly during summer and fall in the Atlantic and in spring in the Pacific. In relation to the pressure distribution in the control run, this indicates a southward extension of the summer mean Atlantic and Pacific subtropical highs. [ABSTRACT FROM AUTHOR]

We present an analysis of a regional simulation of present-day climate (1981–1990) over southern South America. The regional model MM5 was nested within time-slice global atmospheric model experiments conducted by the HadAM3H model. We evaluate the capability of the model in simulating the observed climate with emphasis on low-level circulation patterns and surface variables, such as precipitation and surface air mean, maximum and minimum temperatures. The regional model performance was evaluated in terms of seasonal means, seasonal cycles, interannual variability and extreme events. Overall, the regional model is able to capture the main features of the observed mean surface climate over South America, its seasonal evolution and the regional detail due to topographic forcing. The observed regional patterns of surface air temperatures (mean, maxima and minima) are well reproduced. Biases are mostly within 3°C, temperature being overestimated over central Argentina and underestimated in mountainous regions during all seasons. Biases in northeastern Argentina and southeastern Brazil are positive during austral spring season and negative in other seasons. In general, maximum temperatures are better represented than minimum temperatures. Warm bias is larger during austral summer for maximum temperature and during austral winter for minimum temperature, mainly over central Argentina. The broad spatial pattern of precipitation and its seasonal evolution are well captured; however, the regional model overestimates the precipitation over the Andes region in all seasons and in southern Brazil during summer. Precipitation amounts are underestimated over the La Plata basin from fall to spring. Extremes of precipitation are better reproduced by the regional model compared with the driving model. Interannual variability is well reproduced too, but strongly regulated by boundary conditions, particularly during summer months. Overall, taking into account the quality of the simulation, we can conclude that the regional model is capable in reproducing the main regional patterns and seasonal cycle of surface variables. The present reference simulation constitutes the basis to examine the climate change simulations resulting from the A2 and B2 forcing scenarios which are being reported in a separate study. [ABSTRACT FROM AUTHOR]

Gene regulation at the transcriptional level is a central process in all organisms, and DNA-binding transcription factors, known as TFs, play a fundamental role. This class of proteins usually binds at specific DNA sequences, activating or repressing gene expression. In general, TFs are composed of two domains: the DNA-binding domain (DBD) and an extra domain, which in this work we have named “companion domain” (CD). This latter could be involved in one or more functions such as ligand binding, protein-protein interactions or even with enzymatic activity. In contrast to DBDs, which have been widely characterized both experimentally and bioinformatically, information on the abundance, distribution, variability and possible role of the CDs is scarce. Here, we investigated these issues associated with the domain architectures of TFs in prokaryotic genomes. To this end, 19 families of TFs in 761 non-redundant bacterial and archaeal genomes were evaluated. In this regard we found four main groups based on the abundance and distribution in the analyzed genomes: i) LysR and TetR/AcrR; ii) AraC/XylS, SinR, and others; iii) Lrp, Fis, ArsR, and others; and iv) a group that included only two families, ArgR and BirA. Based on a classification of the organisms according to the life-styles, a major abundance of regulatory families in free-living organisms, in contrast with pathogenic, extremophilic or intracellular organisms, was identified. Finally, the protein architecture diversity associated to the 19 families considering a weight score for domain promiscuity evidenced which regulatory families were characterized by either a large diversity of CDs, here named as “promiscuous” families given the elevated number of variable domains found in those TFs, or a low diversity of CDs. Altogether this information helped us to understand the diversity and distribution of the 19 Prokaryotes TF families. Moreover, initial steps were taken to comprehend the variability of the extra domain in those TFs, which eventually might assist in evolutionary and functional studies. [ABSTRACT FROM AUTHOR]

Due to the importance of the winemaking sector in Mendoza, Argentina, the assessment of future scenarios for viticulture is of foremost relevance. In this context, it is important to understand how temperature increase and precipitation changes will impact on grapes, because of changes in grapevine phenology and suitability wine-growing regions must be understood as an indicator of climate change. The general objective is to classify the suitable areas of viticulture in Argentina for the current and future climate using the MM5 regional climate change simulations. The spatial distribution of annual mean temperature, annual rainfall, and some bioclimatic indices has been analyzed for the present (1970-1989) and future (2080-2099) climate under SRES A2 emission scenario. In general, according to projected average growing season temperature and Winkler index classification, the regional model estimates (i) a reduction of cool areas, (ii) a westward and southward displacement of intermediate and warm suitability areas, and (iii) the arise of new suitability regions (hot and very hot areas) over Argentina. In addition, an increase of annual accumulated precipitation is projected over the center-west of Argentina. Similar pattern of change is modeled for growing season, but with lower intensity. Furthermore, the evaluation of projected seasonal precipitation shows a little precipitation increase over Cuyo and center of Argentina in summer and a little precipitation decrease over Cuyo and northern Patagonia in winter. Results show that Argentina has a great potential for expansion into new suitable vineyard areas by the end of twenty-first century, particularly due to projected displacement to higher latitudes for most present suitability winegrowing regions. Even though main conclusions are based on one global-regional model downscaling, this approach provides valuable information for implementing proper and diverse adaptation measures in the Argentinean viticultural regions. It has been concluded that regional climate change simulations are an adequate methodology, and indeed, the MM5 regional model is an appropriate tool to be applied in viticultural zoning in Mendoza, Argentina. [ABSTRACT FROM AUTHOR]

Background and Aim: Exacerbations of chronic obstructive pulmonary disease (COPD) carry significant consequences for patients and are responsible for considerable health-care costs—particularly if hospitalization is required. Despite the importance of hospitalized exacerbations, relatively little is known about their determinants. This study aimed to analyze predictors of hospitalized exacerbations and mortality in COPD patients. Methods: This was a retrospective population-based cohort study. We selected 900 patients with confirmed COPD aged ≥35 years by simple random sampling among all COPD patients in Cantabria (northern Spain) on December 31, 2011. We defined moderate exacerbations as events that led a care provider to prescribe antibiotics or corticosteroids and severe exacerbations as exacerbations requiring hospital admission. We observed exacerbation frequency over the previous year (2011) and following year (2012). We categorized patients according to COPD severity based on forced expiratory volume in 1 second (Global Initiative for Chronic Obstructive Lung Disease [GOLD] grades 1–4). We estimated the odds ratios (ORs) by logistic regression, adjusting for age, sex, smoking status, COPD severity, and frequent exacerbator phenotype the previous year. Results: Of the patients, 16.4% had ≥1 severe exacerbations, varying from 9.3% in mild GOLD grade 1 to 44% in very severe COPD patients. A history of at least two prior severe exacerbations was positively associated with new severe exacerbations (adjusted OR, 6.73; 95% confidence interval [CI], 3.53–12.83) and mortality (adjusted OR, 7.63; 95%CI, 3.41–17.05). Older age and several comorbidities, such as heart failure and diabetes, were similarly associated. Conclusions: Hospitalized exacerbations occurred with all grades of airflow limitation. A history of severe exacerbations was associated with new hospitalized exacerbations and mortality. [ABSTRACT FROM AUTHOR]

Archaea represent a diverse phylogenetic group that includes free-living, extremophile, mesophile, symbiont, and opportunistic organisms. These prokaryotic organisms share a high significant similarity with the basal transcriptional machinery of Eukarya, and they share regulatory mechanisms with Bacteria, such as operonic organization and DNA-binding transcription factors (TFs). In this work, we identified the repertoire of TFs in 415 archaeal genomes and compared them with their counterparts in bacterial genomes. The comparisons of TFs, at a global level and per family, allowed us to identify similarities and differences between the repertoires of regulatory proteins of bacteria and archaea. For example, 11 of 62 families are more highly abundant in archaea than bacteria, and 13 families are abundant in bacteria but not in archaea and 38 families have similar abundances in the two groups. In addition, we found that archaeal TFs have a lower isoelectric point than bacterial proteins, i.e., they contain more acidic amino acids, and are smaller than bacterial TFs. Our findings suggest a divergence occurred for the regulatory proteins, even though they are common to archaea and bacteria. We consider that this analysis contributes to the comprehension of the structure and functionality of regulatory proteins of archaeal organisms. [ABSTRACT FROM AUTHOR]

Quinoa has been cultivated for millennia in the Andes since its domestication on the shores of Lake Titicaca, between Peru and Bolivia. As a rustic crop of the Andean highlands, it has conquered the international market for less than thirty years. Today, Peru has become the world’s leading producer and the majority of its production is exported. Produced locally by small-scale farmers and consumed globally, quinoa reflects the context of the globalization of agriculture and food. The COVID-19 crisis has also affected Peru and it raises questions about the robustness and resilience of export food chains. This opinion article looks back at debates organized in May–June 2020 in Peru. After recalling the general context of the cultivation of quinoa and the link between COVID-19, agriculture and biodiversity, we highlight the links between health crisis, agricultural crisis and food crisis. This global pandemic offers us the opportunity to question the current agricultural models to draw lessons to build the future. The projection of new solidarities through a collective trademark appears to carry a transnational territorial project at Andean level. Accompanying the actors to make it an inclusive development model requires adapted participatory tools. [ABSTRACT FROM AUTHOR]

Background The regulation of gene expression at the transcriptional level is a fundamental process in prokaryotes. Among the different kind of mechanisms modulating gene transcription, the one based on DNA binding transcription factors, is the most extensively studied and the results, for a great number of model organisms, have been compiled making it possible the in silico construction of their corresponding transcriptional regulatory networks and the analysis of the biological relationships of the components of these intricate networks, that allows to elucidate the significant aspects of their organization and evolution. Results We present a thorough review of each regulatory element that constitutes the transcriptional regulatory network of Bacillus subtilis. For facilitating the discussion, we organized the network in topological modules. Our study highlight the importance of σ factors, some of them acting as master regulators which characterize modules by inter- or intra-connecting them and play a key role in the cascades that define relevant cellular processes in this organism. We discussed that some particular functions were distributed in more than one module and that some modules contained more than one related function. We confirm that the presence of paralogous proteins confers advantages to B. subtilis to adapt and select strategies to successfully face the extreme and changing environmental conditions in which it lives. Conclusions The intricate organization is the product of a non-random network evolution that primarily follows a hierarchical organization based on the presence of transcription and σ factor, which is reflected in the connections that exist within and between modules. [ABSTRACT FROM AUTHOR]

The ability of bacteria and archaea to modulate metabolic process, defensive response, and pathogenic capabilities depend on their repertoire of genes and capacity to regulate the expression of them. Transcription factors (TFs) have fundamental roles in controlling these processes. TFs are proteins dedicated to favor and/or impede the activity of the RNA polymerase. In prokaryotes these proteins have been grouped into families that can be found in most of the different taxonomic divisions. In this work, the association between the expansion patterns of 111 protein regulatory families was systematically evaluated in 1351 non-redundant prokaryotic genomes. This analysis provides insights into the functional and evolutionary constraints imposed on different classes of regulatory factors in bacterial and archaeal organisms. Based on their distribution, we found a relationship between the contents of some TF families and genome size. For example, nine TF families that represent 43.7% of the complete collection of TFs are closely associated with genome size; i.e., in large genomes, members of these families are also abundant, but when a genome is small, such TF family sizes are decreased. In contrast, almost 102 families (56.3% of the collection) do not exhibit or show only a low correlation with the genome size, suggesting that a large proportion of duplication or gene loss events occur independently of the genome size and that various yet-unexplored questions about the evolution of these TF families remain. In addition, we identified a group of families that have a similar distribution pattern across Bacteria and Archaea, suggesting common functional and probable coevolution processes, and a group of families universally distributed among all the genomes. Finally, a specific association between the TF families and their additional domains was identified, suggesting that the families sense specific signals or make specific protein-protein contacts to achieve the regulatory roles. [ABSTRACT FROM AUTHOR]