Tailored particle current in an optical lattice by a weak time-symmetric harmonic potential

Quantum ratchets exhibit asymptotic currents when driven by a time-periodic potential of zero mean if the proper spatio-temporal symmetries are broken. There has been recent debate on whether directed currents may arise for potentials which do not break these symmetries. We show here that, in the presence of degeneracies in the quasienergy spectrum, long-lasting directed currents can be induced, even if the time reversal symmetry is not broken. Our model can be realized with ultracold atoms in optical lattices in the tight-binding regime, and we show that the time scale of the average current can be controlled by extremely weak fields.Comment: 4 pages, 4 figure

Spectral Measures of Bipartivity in Complex Networks

We introduce a quantitative measure of network bipartivity as a proportion of even to total number of closed walks in the network. Spectral graph theory is used to quantify how close to bipartite a network is and the extent to which individual nodes and edges contribute to the global network bipartivity. It is shown that the bipartivity characterizes the network structure and can be related to the efficiency of semantic or communication networks, trophic interactions in food webs, construction principles in metabolic networks, or communities in social networks.Comment: 16 pages, 1 figure, 1 tabl

Catalytical Properties of Free and Immobilized Aspergillus niger Tannase

A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methyl gallate as substrates. KM and Vmax values for free enzyme were very similar for both substrates. But, after immobilization, KM and Vmax values increased drastically using tannic acid as substrate. These results indicated that immobilized tannase is a better biocatalyst than free enzyme for applications on liquid systems with high tannin content, such as bioremediation of tannery or olive-mill wastewater

Novel Strategies for Upstream and Downstream Processing of Tannin Acyl Hydrolase

Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme

Structure of characteristic Lyapunov vectors in spatiotemporal chaos

We study Lyapunov vectors (LVs) corresponding to the largest Lyapunov exponents in systems with spatiotemporal chaos. We focus on characteristic LVs and compare the results with backward LVs obtained via successive Gram-Schmidt orthonormalizations. Systems of a very different nature such as coupled-map lattices and the (continuous-time) Lorenz `96 model exhibit the same features in quantitative and qualitative terms. Additionally we propose a minimal stochastic model that reproduces the results for chaotic systems. Our work supports the claims about universality of our earlier results [I. G. Szendro et al., Phys. Rev. E 76, 025202(R) (2007)] for a specific coupled-map lattice.Comment: 9 page

Typical Mexican agroindustrial residues as supports for solid-state fermentation

Biological wastes contain several reusable substances of high value such as soluble sugars and fiber. Direct disposal of such wastes to soil or landfill causes serious environmental problems. Thus, the development of potential value-added processes for these wastes is highly attractive. These biological wastes can be used as support-substrates in Solid-State Fermentation (SSF) to produce industrially relevant metabolites with great economical advantage. In addition, it is an environment friendly method of waste management. In this study were analyzed six different Mexican agro industrial residues to evaluate their suitability as support-substrate in SSF, between physicochemical properties that have included Water Absorption Index (WAI), Critical Moisture Point (CHP) and Packing Density (PD). The selection of an appropriate solid substrate plays an important role in the development of an efficient SSF process. The results provided important knowledge about the characteristics of these materials revealing their potential for use in fermentation processes.(undefined

Transcranial direct current stimulation in neglect rehabilitation after stroke: a systematic review.

Hemispatial neglect is one of the most frequent attention disorders after stroke. The presence of neglect is associated with longer hospital stays, extended rehabilitation periods, and poorer functional recovery. Transcranial direct current stimulation (tDCS) is a new technique with promising results in neglect rehabilitation; therefore, the objective of this systematic review, performed following the PRISMA guidelines, is to evaluate the effectiveness of tDCS on neglect recovery after stroke. The search was done in MEDLINE (PubMed), Web of Science, Scopus, Cochrane Library, and BioMed Central databases. A total of 311 articles were found; only 11 met the inclusion criteria, including 152 post-stroke patients in total. Methodological quality and risk of bias were assessed for all the studies, and methodological characteristics of the studies, sample sizes, methods, main results, and other relevant data were extracted. tDCS intervention ranged from one to twenty sessions distributed in 1 day to 4 weeks, with intensity ranged from 1 to 2 mA. We found moderate evidence for the efficacy of tDCS in the rehabilitation of hemispatial neglect after a stroke, being more effective in combination with other interventions. Nonetheless, the limited number of studies and some studies' design characteristics makes it risky to draw categorical conclusions. Since scientific evidence is still scarce, further research is needed to determine the advantage of this treatment in acute, sub-acute and chronic stroke patients. Future studies should include larger samples, longer follow-ups, and broader neurophysiological assessments, with the final aim of establishing the appropriate use of tDCS as an adjuvant intervention in neurorehabilitation settings.pre-print964 K

pH-Responsive Polymeric Nanoparticles as Drug Delivery Systems

Micelles are excellent devices to be used as controlled drug delivery systems since they exhibit the ability to protect the drug or encapsulated substance from the routes of degradation until they reach the site of action: moreover, they can pass through biological barriers and reach intracellular compartments. In addition, when a drug is administered and released from the dosage form, the kinetic behavior of the drug depends largely on their chemical structure. However, when the drug is immersed at the core of a NP, the physicochemical properties that actually affect the distribution of the drug in the body are those from the latter. As a result, this approach controls drug release, diminishing side effects and increasing therapeutic rates. In the present work novel smart micelles have been prepared and tested as drug delivery systemsMinisterio de Economía y Competitividad-Grant MAT2016-77345-C3-2-PJunta de Andalucía-Grant P12-FQM-155

A comprehensive sensitivity analisys of the WRF model for air quality applications over the Iberian Peninsula

Meteorological inputs play a vital role on regional air quality modelling. An extensive sensitivity analysis of the Weather Research and Forecasting (WRF) model was performed, in the framework of the Integrated Assessment Modelling System for the Iberian Peninsula (SIMCA) project. Up to 23 alternative model configurations, including Planetary Boundary Layer schemes, Microphysics, Land-surface models, Radiation schemes, Sea Surface Temperature and Four-Dimensional Data Assimilation were tested in a 3 km spatial resolution domain. Model results for the most significant meteorological variables, were assessed through a series of common statistics. The physics options identified to produce better results (Yonsei University Planetary Boundary Layer, WRF Single-Moment 6-class microphysics, Noah Land-surface model, Eta Geophysical Fluid Dynamics Laboratory longwave radiation and MM5 shortwave radiation schemes) along with other relevant user settings (time-varying Sea Surface Temperature and combined grid-observational nudging) where included in a “best case” configuration. This setup was tested and found to produce more accurate estimation of temperature, wind and humidity fields at surface level than any other configuration for the two episodes simulated. Planetary Boundary Layer height predictions showed a reasonable agreement with estimations derived from routine atmospheric soundings. Although some seasonal and geographical differences were observed, the model showed an acceptable behaviour overall. Despite being useful to define the most appropriate setup of the WRF model for air quality modelling over the Iberian Peninsula, this study provides a general overview of WRF sensitivity and can constitute a reference for future mesoscale meteorological modelling exercises

Resistencia a Tuta absoluta en una entrada de la especie silvestre de tomate Solanum pimpinellifolium

2 páginas, 1 figura, 1 tabla.-- Artículo publicado en la revista profesional de sanidad vegetal.-- et al.[EN]: We previously found resistance to pests (twospotted spider mite and whitefly) based on type IV glandular trichomes and acylsucrose production in an accession of the wild tomato species S. pimpinellifolium from the germplasm collection at the Experimental Station La Mayora – CSIC. Resistance to the South American tomato pinworm of that accession and plant materials derived from it was investigated in greenhouse conditions at CNPH (Brasilia, Brazil) and, when Tuta absoluta was introduced into Spain, at Exp. Sta. La Mayora (Málaga, southern Spain). Genotypes carrying type IV glandular trichomes showed reduced pest damage, especially on young, apical leaves. Possibility for control of Tuta by the utilization of resistant tomato cultivars looks forward to future breeding programmes for the trait.[ES]: Una entrada de la especie silvestre de tomate S. pimpinellifolium del banco de germoplasma de la Estación Experimental La Mayora-CSIC presenta resistencia a plagas (araña roja y mosca blanca) merced a sus tricomas glandulares de tipo IV y producción de acilsacarosas. Con el fin de estudiar si esta entrada y otros genotipos de tomate de ella derivados eran también resistentes a T. absoluta, se realizaron experimentos en condiciones de invernadero en CNPH (Brasilia, Brasil) y, una vez que Tuta se introdujo en España, en la E.E. La Mayora (Algarrobo, Málaga). Los genotipos con tricomas de tipo IV sufrieron menores daños por la plaga, especialmente en las hojas apicales, más jóvenes. La posibilidad del control de Tuta mediante la utilización de variedades resistentes queda abierta a futuros programas de mejora genética del carácter.Trabajo financiado por MICINN-FEDER (Proyecto AGL2007-66760-C02-02/AGR).Peer reviewe