On the supercritical KDV equation with time-oscillating nonlinearity

For the initial value problem (IVP) associated to the generalized Korteweg-de Vries (gKdV) equation with supercritical nonlinearity, \begin{equation*} u_{t}+\partial_x^3u+\partial_x(u^{k+1}) =0,\qquad k\geq 5, \end{equation*} numerical evidence [Bona J.L., Dougalis V.A., Karakashian O.A., McKinney W.R.: Conservative, high-order numerical schemes for the generalized Korteweg–de Vries equation. Philos. Trans. Roy. Soc. London Ser. A 351, 107–164 (1995) ] shows that, there are initial data $\phi\in H^1(\mathbb{R})$ such that the corresponding solution may blow-up in finite time. Also, with the evidence from numerical simulation [Abdullaev F.K., Caputo J.G., Kraenkel R.A., Malomed B.A.: Controlling collapse in Bose–Einstein condensates by temporal modulation of the scattering length. Phys. Rev. A 67, 012605 (2003) and Konotop V.V., Pacciani P.: Collapse of solutions of the nonlinear Schrödinger equation with a time dependent nonlinearity: application to the Bose–Einstein condensates. Phys. Rev. Lett. 94, 240405 (2005) ], it has been claimed that a periodic time dependent coefficient in the nonlinearity would disturb the blow-up solution, either accelerating or delaying it. In this work, we investigate the IVP associated to the gKdV equation \begin{equation*} u_{t}+\partial_x^3u+g(\omega t)\partial_x(u^{k+1}) =0, \end{equation*} where $g$ is a periodic function and $k\geq 5$ is an integer. We prove that, for given initial data $\phi \in H^1(\mathbb{R})$, as $|\omega|\to \infty$, the solution $u_{\omega}$ converges to the solution $U$ of the initial value problem associated to \begin{equation*} U_{t}+\partial_x^3U+m(g)\partial_x(U^{k+1}) =0, \end{equation*} with the same initial data, where $m(g)$ is the average of the periodic function $g$. Moreover, if the solution $U$ is global and satisfies $\|U\|_{L_x^5L_t^{10}}<\infty$, then we prove that the solution $u_{\omega}$ is also global provided $|\omega|$ is sufficiently large.M. P. was partially supported by the Research Center of Mathematics of the University of Minho, Portugal through the FCT Pluriannual Funding Program, and through the project PTDC/MAT/109844/2009, and M. S. was partially supported by FAPESP Brazil

Effects of breed‐production system on collagen, textural, and sensory traits of 10 European beef cattle breeds

In the current study the collagen, texture, and sensory characteristics of meat from 712 yearling males of 10 local Spanish and French beef breeds raised in their typical production systems were described. The breed‐production system affected collagen and texture variables but affected sensory variables only slightly. There was a large amount of intra breed‐production system variation for all the variables. French breeds had lower values for collagen solubility (~12%) than Spanish breeds (~40%). Stress (WB) varied from 36 N/cm2 in Casina to 44 N/cm2 in Salers, whereas compression stress at 80% ranged from 35 N/cm2 in Asturiana de los Valles to 40 N/cm2 in Salers. Oven cooking resulted in higher cooking losses (24%) than cooking on a grill (12%). Cooking losses increased as the grill temperature increased. Numerous significant correlations were found among variables. Carcass weight is associated with all the collagen and texture variables. Correlation coefficients among texture and collagen variables were statistically significant and these correlation coefficients were in general higher for solubility percentage than for total collagen content, highlighting the importance of the solubility of collagen rather than total collagen in determining meat textural properties. Practical applications. To differentiate a product in the market, it is necessary to define its characteristics. Differentiation allows increasing the added value of products and, therefore, income of the farmers. In addition, it guarantees to the consumers that the product they purchase has the intrinsic and extrinsic quality features that they seek. For consumers, beef texture is one of the most important quality attributes sought, therefore, studying factors that can affect beef texture is a major interest for the industry.info:eu-repo/semantics/acceptedVersio

Anion Transport by Proteins: Protein Motifs Involved in Anion Binding

Various cellular processes require the participation of specific anions, including Cl-, F-, I-, HCO3- and CO32-. However, their ionic charges impede their permeation across the hydrophobic lipid bilayers of the cells. Cell membranes thus contain specific macromolecular transport proteins, ion channels and transporters, to facilitate and control the passage of anions across the lipid bilayer. Anion-transport proteins need to be able to discriminate between different anions to carry out their function. What drives the protein selectivity for different substrates is a fundamental question that has long fascinated scientists. However, anion recognition in proteins is still poorly understood due to the lack of crystal structures of anion-transporting proteins and the underdevelopment of computational tools for studies of anions. To fill some of these gaps, this thesis elucidates important determinants of ion selectivity in proteins, involved in the transport of Cl-, I-, F-, HCO3-, and CO32- from several different protein families. In chapter 2, we studied carbonate and bicarbonate binding in proteins, through a survey of the preferred coordination numbers, amino acid and atom type composition of the coordination spheres of HCO3- and CO32- in bicarbonate- and carbonate-bound proteins deposited in the Protein DataBank. Some interesting differences in the coordination patterns for HCO3- and CO32- were highlighted. In chapter 3, we evaluated the thermodynamics of anion binding in a series of binding sites constructed from real anion-binding proteins using Quantum Mechanics calculations. The importance of the thermodynamics of binding for the anion selectivity was discussed. In chapters 4 and 5, we assessed the anion dynamics in proteins from the SLC4 and SLC5 families, respectively, using various computational methods, which led to the identification of putative binding sites in the protein matrix for sodium and the transported anions. Our work contributes to the increasing body of knowledge on anion-protein interactions and provides important mechanistic insights into the anion transport and selectivity of several proteins of interest for human physiology

Effect of artichoke (Cynara scolymus L.) by-product on the quality and total phenol content of bread

peer reviewe

Fate and reuse of nitrogen-containing organics from the hydrothermal conversion of algal biomass

Hydrothermal (HT) conversion is a promising and suitable technology for the generation of biofuels from microalgae. Besides the fact that water is used as a “green” reactant and solvent and that no biomass drying is required, the technology offers a potential nutrient source for microalgae culture using an aqueous effluent very rich in essential inorganic nutrients. However, upon continuous and multiple recycling of this HT effluent, the recalcitrant organic fraction is likely to increase and may potentially attain toxic thresholds for microalgae use. In this work, we show the presence of recalcitrant N-containing organic compounds (NOC's) in the HT effluent. The most prominent NOC's in the extracts were carefully examined for their effect on microalgae, namely 2-pyrrolidinone and β-phenylethylamine (β-PEA). The first set of experiments consisted in testing these two substances at three different concentrations (10, 50 and 150 ppm) using three different microalgae strains: Phaeodactylum tricornutum, Chlorella sorokiniana and Scenedesmus vacuolatus. The confirmed half maximal inhibitory concentration (IC50) was approximately 75 ppm for all tested species. In the second set of experiments, P. tricornutum was grown using diluted HT effluent. Experimental conditions were set by adjusting the nitrogen concentration in the HT effluent to be equal to a known commercial medium. The concentrations of specific NOC's were lowered to concentrations of 8.5 mg/L 2-pyrrolidinone and 0.5 mg/L β-PEA after dilution. The growth of P. tricornutum using the diluted HT solution was kept constant with no evidence of inhibition or consumption of NOC's, as the concentration of the specific compounds remains the same before and after growth. Therefore, in order to avoid effects of accumulation of NOC's upon continuous recycling, the HT effluent was pumped through the existing hydrothermal gasification unit as a water clean-up step. The conversion of NOC's to ammonium was successfully achieved

Thermophilic cyanobacteria Leptolyngbya sp

Leptolyngbya sp. INSTML01 16S ribosomal RNA gene, partial sequence GenBank: MG753795.

Extraction of carotenoids from Chlorella vulgaris using green solvents and syngas production from residual biomass

A combined process for carotenoids extraction and efficient bioenergy recovery from the wet microalgae biomass is proposed. High added-value products could thus be extracted prior a hydrothermal gasification of the algal biomass into synthetic natural gas. The economic sustainability of biofuel production from algal biomass as well as the large energy demands of microalgae cultivation and harvesting is addressed in this paper. Two green solvents, ethanol and 2-methyltetrahydrofuran (MTHF), were used to achieve the maximum extractability of selected carotenoids. Pure MTHF was tested for the first time as an alternative renewable solvent for carotenoid extraction from wet biomass and promising results were obtained (30 min at 110 °C), with 45% of total carotenoids being extracted. The energy content of the residual biomass corresponds to a High Heating Value (HHV) of 18.1 MJ/kg. With a 1:1 mixture of both MTHF and ethanol, more carotenoids were extracted from wet biomass (66%) and the remaining HHV of the residual biomass was 15.7 MJ/kg. The perspectives of combined carotenoid extraction and energy recovery for a better microalgae valorization are discussed