Distribution, morphology and habitats of saline wetlands : a case study from Monegros, Spain

Wetlands in semiarid regions have received less attention than wetlands in humidtemperate areas, and the limited amount of information has resulted in little regulatory recognition. A comprehensive map of the saline wetlands that occur in karstic depressions in the semiarid region of Monegros, NE Spain, was developed from historical data, topography, and surveys of vascular flora. Playa-lakes and other saline depressions are expressions of solution dolines largely founded on groundwater dynamics and favored by the limestone and gypsum-rich substrate. Substrate composition, groundwater dynamics, and the network of infilled valleys are key factors in the distribution of the wetlands. In spite of the anthropogenic imprint, wetlands morphometrics are the expression of geological processes. Significant correlations were found between basin area and depth, and between elongation and substrate composition. The predominantly subelongated shape of the Monegros saline wetlands (MSW) reflects their origin and a geometry strongly influenced by fractures. Grouping the MSW based on geological and vegetation features, provide a predictable relationship of surficial processes with the occurrence of otherwise complex and undetectable hydrological connectivity. Our ten geologybased Groups showed a high intra-group variation in depth, elongation, and vegetation cover. The eight vegetation-based categories mirror the gradation in flooding frequency and the soil salinity of MSW. The significant contrasts existing in-between the groups of wetlands and the disclosure of their causal factors provides a functional perspective at the landscape scale. This approach will help to monitor the ongoing environmental alterations associated with new on-farm irrigation developments

A triangle model of criminality

This paper is concerned with a quantitative model describing the interaction of three sociological species, termed as owners, criminals and security guards, and denoted by X, Y and Z respectively. In our model, Y is a predator of the species X, and so is Z with respect to Y . Moreover, Z can also be thought of as a predator of X, since this last population is required to bear the costs of maintaining Z. We propose a system of three ordinary differential equations to account for the time evolution of X(t), Y (t) and Z(t) according to our previous assumptions. Out of the various parameters that appear in that system, we select two of them, denoted by H, and h, which are related with the efficiency of the security forces as a control parameter in our discussion. To begin with, we consider the case of large and constant owners population, which allows us to reduce (3)–(5) to a bidimensional system for Y (t) and Z(t). As a preliminary step, this situation is first discussed under the additional assumption that Y (t) + Z(t) is constant. A bifurcation study is then performed in terms of H and h, which shows the key role played by the rate of casualties in Y and Z, that results particularly in a possible onset of bistability. When the previous restriction is dropped, we observe the appearance of oscillatory behaviours in the full two-dimensional system. We finally provide a exploratory study of the complete model (3)–(5), where a number of bifurcations appear as parameter H changes, and the corresponding solutions behaviours are described

A comparative study of boron transport models in NRC thermal-hydraulic code TRACE

[EN] Recently, the interest in the study of various types of transients involving changes in the boron concentration inside the reactor, has led to an increase in the interest of developing and studying new models and tools that allow a correct study of boron transport. Therefore, a significant variety of different boron transport models and spatial difference schemes are available in the thermal-hydraulic codes. According to this interest, in this work it will be compared the results obtained using the different boron transport models implemented in the NRC thermal-hydraulic code TRACE. To do this, a set of models has been created using the different options and configurations that could have influence in boron transport. These models allow us to reproduce a simple event of filling or emptying the boron concentration in a long pipe. Moreover, with the aim to compare the differences obtained when one-dimensional or three-dimensional components are chosen, it has modeled many different cases using only pipe components or a mix of pipe and vessel components. In addition, the influence of the void fraction in the boron transport has been studied and compared under close conditions to a BWR commercial model. A final collection of the different cases and boron transport models are compared between them and those corresponding to the analytical solution provided by the Burgers equation. From this comparison, important conclusions are drawn that will be the basis of modeling the boron transport in TRACE adequately.Olmo-Juan, N.; Barrachina Celda, TM.; Miró Herrero, R.; Verdú Martín, GJ.; Pereira, C. (2019). A comparative study of boron transport models in NRC thermal-hydraulic code TRACE. Brazilian Journal of Radiation Sciences. 7(2B):1-18. https://doi.org/10.15392/bjrs.v7i2B.767S11872

Ensayo biogeográfico de la Pteridoflora valenciana

En el presente trabajo se realiza un análisis comparativo de las pteridofloras de los diiferentes sectores fitogeográficos (sensu Costa, 1986) que integran la Comunidad Valenciana.The present paper deals with the biogeography and of pteridophytes in the Comunidad Valenciana (Levante, Spain), following the present chorological division of this area

Cleavage of the C-C bond in the ethanol oxidation reaction on platinum. Insight from experiments and calculations

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b03117, see http://pubs.acs.org/page/policy/articlesonrequest/index.html".[EN] Using a combination of experimental and computational methods, mainly FTIR and DFT calculations, new insights are provided here in order to better understand the cleavage of the C–C bond taking place during the complete oxidation of ethanol on platinum stepped surfaces. First, new experimental results pointing out that platinum stepped surfaces having (111) terraces promote the C–C bond breaking are presented. Second, it is computationally shown that the special adsorption properties of the atoms in the step are able to promote the C–C scission, provided that no other adsorbed species are present on the step, which is in agreement with the experimental results. In comparison with the (111) terrace, the cleavage of the C–C bond on the step has a significantly lower activation energy, which would provide an explanation for the observed experimental results. Finally, reactivity differences under acidic and alkaline conditions are discussed using the new experimental and theoretical evidence.This work has been financially supported by the MINECO (Spain) (project CTQ2013-44083-P) and Generalitat Valenciana (project PROMETEOII/2014/013).Ferre Vilaplana, A.; Buso-Rogero, C.; Feliu, JM.; Herrero, E. (2016). Cleavage of the C-C bond in the ethanol oxidation reaction on platinum. Insight from experiments and calculations. Journal of Physical Chemistry C. 120(21):11590-11597. https://doi.org/10.1021/acs.jpcc.6b03117S11590115971202

Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology

BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients. METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients. RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005). CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second

Recent advances on dendrogeomorphological research applied to flood hazard analysis in Spain.

Estudios dendroecológicos para el análisis de regímentes torrenciales y avenida

Microwave-assisted functionalization of carbon nanohorns with oligothiophene units with SERS activity

[EN] Carbon nanohorns have been functionalized with oligothiophene unitsviathe 1,3-dipolar cycloaddition reaction under microwave irradiation and solvent-free conditions. A dramatic Raman enhancement was found for one of the synthesized derivatives. Experimental andin silicostudies helped to understand the enhancement, attributed to the modification of electromagnetic fields upon functionalization at the tip of the nanostructures.This work was supported by the Iberdrola Foundation (CONV120313), the Spanish Ministerio de Economia y Competitividad (CTQ2017-88158-R), the Junta de Comunidades de Castilla-La Mancha (SBPLY/17/180501/000204) and FEDER-JCCM (UNCM13-1E-1663). The work at the University of Malaga was funded by the MICINN (PID2019-110305GB-I00) and Junta de Andalucia (P09FQM-4708) projects. M. I. L. acknowledges MINECO for her Juan de la Cierva-formacion grant (FJCI-2016-29593). The authors acknowledge the computer resources, technical expertise, and assistance provided by the Supercomputing and Bioinformatics centre of the University of Malaga.Iglesias, D.; Guerra, J.; Lucío, MI.; González-Cano, RC.; Lopez Navarrete, JT.; Ruiz Delgado, MC.; Vázquez, E.... (2020). Microwave-assisted functionalization of carbon nanohorns with oligothiophene units with SERS activity. Chemical Communications. 56(63):8948-8951. https://doi.org/10.1039/D0CC03496G89488951566

Expression of Wilms' tumor suppressor in the liver with cirrhosis: relation to hepatocyte nuclear factor 4 and hepatocellular function

The Wilms' tumor suppressor WT1 is a transcriptional regulator present in the fetal but not in the mature liver. Its expression and functional role in liver diseases remains unexplored. In this study, we analyzed WT1 expression by reverse-transcription polymerase chain reaction (RT-PCR) and by immunohistochemistry in normal and diseased livers. In addition, we performed in vitro studies in isolated rat hepatocytes to investigate WT1 regulation and function. We detected WT1 messenger RNA (mRNA) in 18% of normal livers, 17% of chronic hepatitis with minimal fibrosis, 49% of chronic hepatitis with bridging fibrosis, and 71% of cirrhotic livers. In cirrhosis, WT1 immunoreactivity was localized to the nucleus of hepatocytes. WT1 mRNA abundance correlated inversely with prothrombin time (P =.04) and directly with serum bilirubin (P =.002) and with the MELD score (P =.001) of disease severity. In rats, WT1 expression was present in fetal hepatocytes and in the cirrhotic liver but not in normal hepatic tissue. In vitro studies showed that isolated primary hepatocytes express WT1 when stimulated with transforming growth factor beta (TGF-beta) or when the cells undergo dedifferentiation in culture. Moreover, we found that WT1 down-regulates hepatocyte nuclear factor 4 (HNF-4), a factor that is essential to maintain liver function and metabolic regulation in the mature organ. Hepatic expression of HNF-4 was impaired in advanced human cirrhosis and negatively correlated with WT1 mRNA levels (P =.001). In conclusion, we show that WT1 is induced by TGF-beta and down-regulates HNF-4 in liver cells. WT1 is reexpressed in the cirrhotic liver in relation to disease progression and may play a role in the development of hepatic insufficiency in cirrhosis