605 research outputs found
Limits of flexural wave absorption by open lossy resonators: reflection and transmission problems
The limits of flexural wave absorption by open lossy resonators are
analytically and numerically reported in this work for both the reflection and
transmission problems. An experimental validation for the reflection problem is
presented. The reflection and transmission of flexural waves in 1D resonant
thin beams are analyzed by means of the transfer matrix method. The hypotheses,
on which the analytical model relies, are validated by experimental results.
The open lossy resonator, consisting of a finite length beam thinner than the
main beam, presents both energy leakage due to the aperture of the resonators
to the main beam and inherent losses due to the viscoelastic damping. Wave
absorption is found to be limited by the balance between the energy leakage and
the inherent losses of the open lossy resonator. The perfect compensation of
these two elements is known as the critical coupling condition and can be
easily tuned by the geometry of the resonator. On the one hand, the scattering
in the reflection problem is represented by the reflection coefficient. A
single symmetry of the resonance is used to obtain the critical coupling
condition. Therefore the perfect absorption can be obtained in this case. On
the other hand, the transmission problem is represented by two eigenvalues of
the scattering matrix, representing the symmetric and anti-symmetric parts of
the full scattering problem. In the geometry analyzed in this work, only one
kind of symmetry can be critically coupled, and therefore, the maximal
absorption in the transmission problem is limited to 0.5. The results shown in
this work pave the way to the design of resonators for efficient flexural wave
absorption
Pesticides in the Ebro River basin: Occurrence and risk assessment
In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 21% of the samples, respectively). The only pesticide detected in biota was chlorpyrifos (up to 840.2 ng g−1). Ecotoxicological risk assessment through RQs showed that organophosphorus and azol presented high risk for algae; organophosphorus, benzimidazoles, carbamates, juvenile hormone mimic and other pesticides for daphnia, and organophosphorus, azol and juvenile hormone mimics for fish. The sum TUsite for water and sediments showed values < 1 for the three bioassays. In both matrices, daphnia and fish were more sensitive to the mixture of pesticide residues present.This work has been supported by the Spanish Ministry of
Economy and Competitiveness through the projects NET-SCARCE
project (CTM2015-69780-REDC); “Evaluation of Emerging Contaminants
in the Turia River Basins: From Basic Research to the
Application of Environmental Forensics (EMERFOR)” (GCL2011-
29703-C02-02, http://mefturia.es) and European Communities 7th
Framework Programme funding under Grant Agreement No.
603629-ENV-2013-6.2.1-Globaqua. A, Ccanccapa gratefully acknowledges
the Conselleria DEducaci o, Cultura y Sport de Valencia
for the financial support through “Santiago Grisolía” Scholarship
Program.Peer reviewe
Quantum algorithm for the Laughlin wave function
We construct a quantum algorithm that creates the Laughlin state for an
arbitrary number of particles in the case of filling fraction one. This
quantum circuit is efficient since it only uses local qudit gates
and its depth scales as . We further prove the optimality of the circuit
using permutation theory arguments and we compute exactly how entanglement
develops along the action of each gate. Finally, we discuss its experimental
feasibility decomposing the qudits and the gates in terms of qubits and two
qubit-gates as well as the generalization to arbitrary filling fraction.Comment: 4 pages, 5 figure
Biological extraction of bromelain from pineapple byproducts
[Excerpt] Isolation and purification of valuable compounds are very important processes to valorize agro-food byproducts. Currently, protein extraction and development of environmentally friendly technologies are industrially relevant topics [1]. Among the extracted proteins from byproducts proteases are a relevant group for industrial applications. These enzymes are a class of hydrolytic enzymes capable of cleaving the peptide bonds of proteins chains and are essential in physiological processes [2]. (...
Liquid–liquid equilibrium of the Ucon 50-HB5100/sodium citrate aqueous two-phase systems
The phase diagrams of Ucon 50-HB5100/sodium citrate aqueous two-phase systems were determined at 5, 20 and 40 ◦C. Two medium pHs
5.20 and 8.20 were assayed. The binodal curves were satisfactorily described using a four-parameter sigmoidal equation. The two-phase area was
expanded by increasing both pH and temperature. The reliability of the measured tie line compositions was ascertained by correlation equations
given by Othmer–Tobias and Bancroft.VALNATURACONICETALFA II-0440-FA-Exchange programme between Universities
of the European Union and Latin Americ
Liquid-liquid equilibrium and partitioning features of bovine trypsin in Ucon 50 HB5100 /sodium citrate aqueous two phase systems
The phase diagrams of Ucon 50-HB-5100, a non-ionic random copolymer of ethylene oxide and propylene
oxide (EOPO) and sodium citrate aqueous two-phase systems were determined at different pHs (5.20
and 8.20) and temperatures (5, 20 and 40º C). The binodal curves were determined by refractive index and
enzymatic assay of the solution and described using a four-parameter sigmoidal equation, the reliability
of the measured tie line compositions was ascertained by correlation equations given by Othmer Tobias
and Bancroft. The two-phase area was expanded by increasing both pH and temperature. The partitioning
of bovine trypsin and a-chymotrypsin, proteases of similar physico-chemical properties was investigated
in order to evaluate the applicability of partitioning as a putative method to isolate from pancreas and to
obtain any information about their partitioning mechanism. The effect of different factors such as pH, tie
line length and the presence of an inorganic salt on the protein partition coefficient were analyzed.Se caracterizaron las curvas binomiales correspondientes a los sistemas bifásicos acuosos formados por
Ucon 50-HB-5100, un copolímero al azar de óxido de etileno y óxido de propileno (EOPO) y citrato de
sodio a diferentes pHs (5,20 y 8,20) y temperaturas (5, 20 y 40º C). Las curvas binomiales se obtuvieron
por determinación del índice de refracción y ensayos enzimáticos de las soluciones correspondientes; las
composiciones de las líneas de unión se corroboraron por las ecuaciones propuestas por Othmer Tobias y
Bancroft. El aumento del pH y la temperatura condujeron a un aumento del área bifásica. También se
ensayó el comportamiento de reparto de dos proteasas tripsina y α-quimotripsina con el objetivo de
emplear los principios de partición como método de aislamiento y purificación de Tripsina a partir de páncreas
bovino y de obtener información acerca del mecanismo de partición de la misma. Se analizó el efecto
del pH, longitud de la línea de unión y presencia de sales inorgánicas sobre el coeficiente de partición
de las enzimas
Resistance to melon vine decline derived from Cucumis melo spp. agrestis: genetic analysis of root structure and root response.
Melon vine decline is a major soilborne disease that causes severe economic losses around the world
First report of neocosmospora falciformis Causing Wilt and Root Rot of Muskmelon in Spain
‘Cantaloupe’ and ‘Piel de Sapo’ are melon (Cucumis melo L.) varieties cultivated in Spain. In 2018, during a pathogens survey in experimental fields of Valencia and Alicante provinces (southeast Spain), wilt and root rot of melon plants were detected in grafted and ungrafted plants. Disease incidence ranged from 10% (Alicante) to 45% (Valencia). Symptoms included yellowing and wilting of leaves, rotting at the stem base and upper root, and collapse of the entire plant. Samplings were conducted from severely decayed and dead plants. Fragments (0.5 to 1 cm) from rotted lower stems and roots were surface disinfected for 1 min in 1.5% NaOCl, washed twice with sterilized distilled water, and plated onto potato dextrose agar (PDA) with streptomycin sulfate (0.5 g/liter). Plates were incubated at 25°C in the dark for 3 to 5 days. Mycelia resembling Fusarium were isolated and characterized by morphological and molecular methods. Based on their adpressed beige mycelia, growth in concentric rings, and absence of sporodochia, colonies growing on PDA and Spezieller Nährstoffarmer agar were preliminary identified as belonging to the Fusarium solani species complex. On PDA, colonies were white-greyish to pale-cream growing in concentric rings with beige reverse after 6 days. No sporodochia were observed. Macroconidia were slender, falcate, hyaline, ..
Ecological, genetic and evolutionary drivers of regional genetic differentiation in Arabidopsis thaliana
Background: Disentangling the drivers of genetic differentiation is one of the cornerstones in evolution. This is because genetic diversity, and the way in which it is partitioned within and among populations across space, is an important asset for the ability of populations to adapt and persist in changing environments. We tested three major hypotheses accounting for genetic differentiation—isolation-by-distance (IBD), isolation-by-environment (IBE) and isolation-by-resistance (IBR)—in the annual plant Arabidopsis thaliana across the Iberian Peninsula, the region with the largest genomic diversity. To that end, we sampled, genotyped with genome-wide SNPs, and analyzed 1772 individuals from 278 populations distributed across the Iberian Peninsula.
Results: IBD, and to a lesser extent IBE, were the most important drivers of genetic differentiation in A. thaliana. In other words, dispersal limitation, genetic drift, and to a lesser extent local adaptation to environmental gradients, accounted for the within- and among-population distribution of genetic diversity. Analyses applied to the four Iberian genetic clusters, which represent the joint outcome of the long demographic and adaptive history of the species in the region, showed similar results except for one cluster, in which IBR (a function of landscape heterogeneity) was the most important driver of genetic differentiation. Using spatial hierarchical Bayesian models, we found that precipitation seasonality and topsoil pH chiefly accounted for the geographic distribution of genetic diversity in Iberian A. thaliana.
Conclusions: Overall, the interplay between the influence of precipitation seasonality on genetic diversity and the effect of restricted dispersal and genetic drift on genetic differentiation emerges as the major forces underlying the evolutionary trajectory of Iberian A. thaliana
Transcriptome analysis in blood cells from children reveals potential early biomarkers of metabolic alterations
OBJECTIVES: The development of effective strategies to prevent childhood obesity and its comorbidities requires new, reliable early biomarkers. Here, we aimed to identify in peripheral blood cells potential transcript-based biomarkers of unhealthy metabolic profile associated to overweight/obesity in children.
METHODS: We performed a whole-genome microarray analysis in blood cells to identify genes differentially expressed between overweight and normal weight children to obtain novel transcript-based biomarkers predictive of metabolic complications.
RESULTS: The most significant enriched pathway of differentially expressed genes was related to oxidative phosphorylation, for which most of genes were downregulated in overweight versus normal weight children. Other genes were involved in carbohydrate metabolism/glucose homoeostasis or in lipid metabolism (for example, TCF7L2, ADRB3, LIPE, GIPR), revealing plausible mechanisms according to existing biological knowledge. A set of differentially expressed genes was identified to discriminate in overweight children those with high or low triglyceride levels.
CONCLUSIONS: Functional microarray analysis has revealed a set of potential blood-cell transcript-based biomarkers that may be a useful approach for early identification of children with higher predisposition to obesity-related metabolic alterations
- …