Viability of some probiotic coatings in bread and its effect on the crust mechanical properties

9 pages, 4 figures, 3 tablesThe objective of this study was to obtain functional bread combining the microencapsulation of Lactobacillus acidophilus and starch based coatings. Different probiotic coatings (dispersed or multilayer) were applied onto the surface of partially baked breads. In all treatments, microencapsulated L.acidophilus survived after baking and storage time, although reduction was higher in the sandwich treatment (starch solution/sprayed microcapsules/starch solution). Despite coatings significantly affected the physicochemical properties of the crust, increasing water activity and reducing the failure force, the sensory evaluation revealed a good acceptability of the functional breads. Scanning electron microscopy revealed the presence of scattered microcapsules onto the bread crust, being highly covered in the sandwich coating. Therefore, L.acidophilus included in microcapsules can be incorporated to bread surface through edible coatings, leading functional bread with similar characteristics to common bread, but with additional healthy benefits.Authors acknowledge the financial support of Spanish Ministry of Economy and Sustainability (Project AGL2011-23802) and the Consejo Superior de Investigaciones Científicas (CSIC). Authors thank Mr. Alfonso Martínez from CICATA, IPM (México) for his contribution with the electron microscopy analysis. R. Altamirano-Fortoul would like to thank her PhD grant (JAE pre) to CSIC. The authors also thank Forns Valencians S.A. (Spain) for supplying commercial frozen partially baked breads.Peer reviewe

Worsening water quality conditions at Inner Puno Bay, Lake Titicaca, Peru, and their effect on Lemna spp. biomass

Although there have been a number of studies on aquatic conditions and the flora and fauna of Lake Titicaca over many decades (Gilson 1939, 1964; Uéno 1967; Richerson et al. 1975), most of this work has been centred on the offshore regions of the main lake. More recently studies have begun to focus on near-shore waters, especially of Inner Puno Bay (Luna 1981; Northcote et al. 1989 (Spanish version 1991)). Here there has been a deterioration in water quality conditions, especially near areas close to a levee built very recently for tourist viewing, called ‘Bahia de los Incas’ (Figs. 1, 2, 3). Water quality there has been degrading and abundant growth of Lemna spp. has been developing (Cruz 2005). To some extent this Lemna growth can take up nutrients (Quispe 1999) and heavy metals (Choque 2000), but these would be released, in part, with annual die-down

Выход загруженных веществ in vitro из системы упорядоченных биодеградируемых отдельностоящих микрокамер

We address in this paper the optimization of a multi-site, multi-period, and multi-product planning problem with sequence-dependent changeovers, which is modeled as a mixed-integer linear programming (MILP) problem. Industrial instances of this problem require the planning of a number of production and distribution sites over a time span of several months. Temporal and spatial Lagrangean decomposition schemes can be useful for solving these types of large-scale production planning problems. In this paper we present a theoretical result on the relative size of the duality gap of the two decomposition alternatives. We also propose a methodology for exploiting the economic interpretation of the Lagrange multipliers to speed the convergence of numerical algorithms for solving the temporal and spatial Lagrangean duals. The proposed methods are applied to the multi-site multi-period planning problem in order to illustrate their computational effectiveness.</p

Physicochemical characterization and presence of heavy metals in the trout farming area of Lake Titicaca, Peru

Certain areas of Lake Titicaca exhibit signs of contamination from urban drainage, mining tailings, and waste from trout cage farming. The objective of this study was to determine the physicochemical conditions of the water and the concentration of heavy metals in sediments of a trout (Oncorhynchus mykiss) farming area in Puno Bay, Lake Titicaca. Water samples were collected at depths of 1, 5, 10, and 15 meters from the surface, as well as from sediments at the bottom of the lake. Additionally, samples were taken 500 meters from the trout breeding area, where no farming activities took place. The study was carried out over a period of 10 months. Some physical-chemical measurements were taken in situ using a multiparametric device, while others were carried out at IMARPE’s laboratory. The results indicate that the physical-chemical quality of the water does not exceed the tolerance limits recommended by the Environmental Quality Standards - ECA Peru. The water pH was 8.79 and the dissolved oxygen was 6.81. The heavy metals (Hg, Cd, Pb, Zn, Cu) found in the sediments were within the permissible limits compared to the ISQG Canada Standard. However, the concentration of As, at 41 mg kg-1, exceeded the tolerance limit. Uncontrolled trends in trout production volumes could compromise water quality and sustainability

Dense stellar clump formation driven by strong quasar winds in the FIRE cosmological hydrodynamic simulations

We investigate the formation of dense stellar clumps in a suite of high-resolution cosmological zoom-in simulations of a massive, star forming galaxy at $z \sim 2$ under the presence of strong quasar winds. Our simulations include multi-phase ISM physics from the Feedback In Realistic Environments (FIRE) project and a novel implementation of hyper-refined accretion disk winds. We show that powerful quasar winds can have a global negative impact on galaxy growth while in the strongest cases triggering the formation of an off-center clump with stellar mass ${\rm M}_{\star}\sim 10^{7}\,{\rm M}_{\odot}$, effective radius ${\rm R}_{\rm 1/2\,\rm Clump}\sim 20\,{\rm pc}$, and surface density $\Sigma_{\star} \sim 10^{4}\,{\rm M}_{\odot}\,{\rm pc}^{-2}$. The clump progenitor gas cloud is originally not star-forming, but strong ram pressure gradients driven by the quasar winds (orders of magnitude stronger than experienced in the absence of winds) lead to rapid compression and subsequent conversion of gas into stars at densities much higher than the average density of star-forming gas. The AGN-triggered star-forming clump reaches ${\rm SFR} \sim 50\,{\rm M}_{\odot}\,{\rm yr}^{-1}$ and $\Sigma_{\rm SFR} \sim 10^{4}\,{\rm M}_{\odot}\,{\rm yr}^{-1}\,{\rm kpc}^{-2}$, converting most of the progenitor gas cloud into stars in $\sim$2\,Myr, significantly faster than its initial free-fall time and with stellar feedback unable to stop star formation. In contrast, the same gas cloud in the absence of quasar winds forms stars over a much longer period of time ($\sim$35\,Myr), at lower densities, and losing spatial coherency. The presence of young, ultra-dense, gravitationally bound stellar clumps in recently quenched galaxies could thus indicate local positive feedback acting alongside the strong negative impact of powerful quasar winds, providing a plausible formation scenario for globular clusters.Comment: 14 pages, 12 figure

Local positive feedback in the overall negative: the impact of quasar winds on star formation in the FIRE cosmological simulations

Negative feedback from accreting supermassive black holes is regarded as a key ingredient in suppressing star formation and quenching massive galaxies. However, several models and observations suggest that black hole feedback may have a positive effect, triggering star formation by compressing interstellar medium gas to higher densities. We investigate the dual role of black hole feedback using cosmological hydrodynamic simulations from the Feedback In Realistic Environments (FIRE) project, including a novel implementation of hyper-refined accretion-disc winds. Focusing on a massive, star-forming galaxy at $z \sim 2$ ($M_{\rm halo} \sim 10^{12.5} \, {\rm M}_{\odot}$), we show that strong quasar winds with kinetic power $\sim$10$^{46}$ erg/s acting for $>$20$\,$Myr drive the formation of a central gas cavity and can dramatically reduce the star formation rate surface density across the galaxy disc. The suppression of star formation is primarily driven by reducing the amount of gas that can become star-forming, compared to directly evacuating the pre-existing star-forming gas reservoir (preventive feedback dominates over ejective feedback). Despite the global negative impact of quasar winds, we identify several plausible signatures of local positive feedback, including: (1) spatial anti-correlation of wind-dominated regions and star-forming clumps, (2) higher local star formation efficiency in compressed gas near the edge of the cavity, and (3) increased local contribution of outflowing material to star formation. Stars forming under the presence of quasar winds tend to do so at larger radial distances. Our results suggest that positive and negative AGN feedback can coexist in galaxies, but local positive triggering of star formation plays a minor role in global galaxy growth.Comment: 17 pages, 12 figure

Los desafíos del cambio : investigación en diseño

1 archivo PDF (194 páginas)Aborda los desafíos del cambio y la investigación en diseño - a 30 años de distancia de la creación de la Universidad Autónoma Metropolitana y de ejercer la figura de profesor investigador, signo distintivo de nuestra Institución -trata los cambios y desafíos que se han presentado durante este tiempo, con relación a su objeto de estudio, la manera como se concibe y realiza la investigación, como en la práctica se ha dado - o no- el binomio investigación docencia y cómo se enfrentan las dificultades y las soluciones que han tomado los profesores-investigadores

Water Network Optimization with Wastewater Regeneration Models

The conventional water network synthesis approach greatly simplifies wastewater treatment units by using fixed recoveries, creating a gap for their applicability to industrial processes. This work describes a unifying approach combining various technologies capable of removing all the major types of contaminants through the use of more realistic models. The following improvements are made over the typical superstructure-based water network models. First, unit-specific shortcut models are developed in place of the fixed contaminant removal model to describe contaminant mass transfer in wastewater treatment units. Shortcut wastewater treatment cost functions are also incorporated into the model. In addition, uncertainty in mass load of contaminants is considered to account for the range of operating conditions. Furthermore, the superstructure is modified to accommodate realistic potential structures. We present a modified Lagrangean-based decomposition algorithm in order to solve the resulting nonconvex mixed-integer nonlinear programming (MINLP) problem efficiently. Several examples are presented to illustrate the effectiveness and limitations of the algorithm for obtaining the global optimal solutions.The authors would like to acknowledge financial support from the National Science Foundation for financial support under grant CBET-1437668, the program “Estancias de movilidad en el extranjero “Jose Castillejo” para jóvenes doctores” (JC2011-0051) of the Spanish Ministerio de Educación, and from the University of Alicante (GRE11-19)