Efecto de la aplicación de soluciones de Chorella Vulgaris y Scenedesmus Obliquus sobre el contenido de compuestos funcionales en germinados de brócoli

107 Páginas.Existe evidencia que vincula la calidad de nutrientes disponible para las plantas durante su crecimiento con la producción de diversos compuestos fitoquímicos. En este proyecto se evaluó el efecto de la aplicación de 10 soluciones de tratamiento preparados a partir de cultivos de las micro algas Chlorella vulgaris y Scenedesmus obliquus como fuente nutritiva, sobre el contenido de compuestos fitoquímicos funcionales (β-caroteno, ácido ascórbico, sulforafane y actividad antioxidante) en germinados de brócoli de 7 y 14 días por su potencialidad como alimento funcional. Los resultados indicaron que algunas de las soluciones de micro algas tienen la capacidad de mejorar el contenido de estos compuestos fitoquímicos, encontrándose un incremento de hasta un 100% en el sulforafane y ácido ascórbico de algunas muestras

Study of samples geometry to analyze mechanical properties in Fused Deposition Modeling process (FDM)

[EN] Parts manufactured by Fused Deposition Modeling (FDM) present anisotropic properties, which have influence in tensile test results. In this paper, test samples of Polylactide (PLA) are manufactured by FDM according to geometries defined in UNE-EN ISO 527-2:2012 and ASTM D638-14:2014. Manufacturing parameters as wall thickness, orientation of building wall lines, and orientation of infill pattern have beeen studied. A nomenclature to define manufacturing direction of sample is also developed. Stress concentration can modify obtained results in tensile test, and it could be due to geometrical discontinuities, pressure points and thermal shock. Standard and no standard geometries have been evaluated to test FDM process. In order to avoid premature sample failure by stress concentration, different strategies have been developed: manufacturing samples with a rectangular geometry, an annealing treatment and to manufacture the samples as union of different parts. Last strategy has allowed to reduce stress concentration zones and to improve tensile strength values.Lluch-Cerezo, J.; Benavente Martínez, R.; Meseguer, M.; Gutiérrez, SC. (2019). Study of samples geometry to analyze mechanical properties in Fused Deposition Modeling process (FDM). Procedia Manufacturing. 41:890-897. https://doi.org/10.1016/j.promfg.2019.10.012S89089741Lee, J.-Y., An, J., & Chua, C. K. (2017). Fundamentals and applications of 3D printing for novel materials. Applied Materials Today, 7, 120-133. doi:10.1016/j.apmt.2017.02.004T. Wohlers, 3D Printing and Additive Manufacturing State of the Industry, Wohlers Report 2016 Wohlers Associates, Inc., 2016.Dizon, J. R. C., Espera, A. H., Chen, Q., & Advincula, R. C. (2018). Mechanical characterization of 3D-printed polymers. Additive Manufacturing, 20, 44-67. doi:10.1016/j.addma.2017.12.002Ahn, S., Montero, M., Odell, D., Roundy, S., & Wright, P. K. (2002). Anisotropic material properties of fused deposition modeling ABS. Rapid Prototyping Journal, 8(4), 248-257. doi:10.1108/13552540210441166Chacón, J. M., Caminero, M. A., García-Plaza, E., & Núñez, P. J. (2017). Additive manufacturing of PLA structures using fused deposition modelling: Effect of process parameters on mechanical properties and their optimal selection. Materials & Design, 124, 143-157. doi:10.1016/j.matdes.2017.03.065Wendt, C., Valerga, A. P., Droste, O., Batista, M., & Marcos, M. (2017). FEM based evaluation of Fused Layer Modelling monolayers in tensile testing. Procedia Manufacturing, 13, 916-923. doi:10.1016/j.promfg.2017.09.160Rodríguez-Panes, A., Claver, J., & Camacho, A. (2018). The Influence of Manufacturing Parameters on the Mechanical Behaviour of PLA and ABS Pieces Manufactured by FDM: A Comparative Analysis. Materials, 11(8), 1333. doi:10.3390/ma11081333Rankouhi, B., Javadpour, S., Delfanian, F., & Letcher, T. (2016). Failure Analysis and Mechanical Characterization of 3D Printed ABS With Respect to Layer Thickness and Orientation. Journal of Failure Analysis and Prevention, 16(3), 467-481. doi:10.1007/s11668-016-0113-2Z. Liu, Y. Wang, B. Wu, C. Cui, Y. Guo, C. Yan, A critical review of fused deposition modeling 3D printing technology in manufacturing polylactic acid parts, The International Journal of Advanced Manufacturing Technology, doi.org/10.1007/s00170-019-03332-x.Yao, T., Deng, Z., Zhang, K., & Li, S. (2019). A method to predict the ultimate tensile strength of 3D printing polylactic acid (PLA) materials with different printing orientations. Composites Part B: Engineering, 163, 393-402. doi:10.1016/j.compositesb.2019.01.025ASTM D638-14:2014, “Standard test method for tensile properties of plastics”, ASTM International, West Conshohocken, PA, 2014.A. Rodríguez-Panes, J. Claver, A. M. Camacho, M. A. Sebastián, Análisis normativo y evaluación geométrica de probetas para la caracterización mecánica de piezas obtenidas por fabricación aditiva mediante FDM. Actas Del XXII Congreso Nacional de Ingeniería Mecánica, (September), (2018) 1–11.Lanzotti, A., Grasso, M., Staiano, G., & Martorelli, M. (2015). The impact of process parameters on mechanical properties of parts fabricated in PLA with an open-source 3-D printer. Rapid Prototyping Journal, 21(5), 604-617. doi:10.1108/rpj-09-2014-0135UNE-EN ISO/ASTM 52921:2017, “Terminología normalizada para la fabricación aditiva. Sistemas de coordenadas y métodos de ensayo”, Asociación Española de Normalización y Certificación, Madrid, 2017

An iterative semi-implicit scheme with robust damping

An efficient, iterative semi-implicit (SI) numerical method for the time integration of stiff wave systems is presented. Physics-based assumptions are used to derive a convergent iterative formulation of the SI scheme which enables the monitoring and control of the error introduced by the SI operator. This iteration essentially turns a semi-implicit method into a fully implicit method. Accuracy, rather than stability, determines the timestep. The scheme is second-order accurate and shown to be equivalent to a simple preconditioning method. We show how the diffusion operators can be handled so as to yield the property of robust damping, i.e., dissipating the solution at all values of the parameter \mathcal D\dt, where $\mathcal D$ is a diffusion operator and \dt the timestep. The overall scheme remains second-order accurate even if the advection and diffusion operators do not commute. In the limit of no physical dissipation, and for a linear test wave problem, the method is shown to be symplectic. The method is tested on the problem of Kinetic Alfv\'en wave mediated magnetic reconnection. A Fourier (pseudo-spectral) representation is used. A 2-field gyrofluid model is used and an efficacious k-space SI operator for this problem is demonstrated. CPU speed-up factors over a CFL-limited explicit algorithm ranging from $\sim20$ to several hundreds are obtained, while accurately capturing the results of an explicit integration. Possible extension of these results to a real-space (grid) discretization is discussed.Comment: Submitted to the Journal of Computational Physics. Clarifications and caveats in response to referees, numerical demonstration of convergence rate, generalized symplectic proo

Navigating Liminal Legalities Along Pathways To Citizenship: Immigrant Vulnerability and the Role of Mediating Institutions

In this report, we summarize the findings of research funded by the Russell Sage Foundation and conducted in Southern California over the course of eighteen months between January 2014 and September 2015. This time period coincided with the announcement of and subsequent legal challenges to the DACA and DAPA program – a period characterized by extreme legal uncertainty over the availability and scope of these “Executive Relief” programs. Drawing from 16 in-depth interviews with staff of 10 different immigrant serving organizations and 47 interviews with noncitizens in the Los Angeles and Orange County areas, we captured the on-the-ground challenges facing noncitizens and community based organizations as the scope and availability of Executive Relief was debated. In our research, we focused on the hardships and barriers to incorporation imposed by liminal legal status, the challenges faced by organizations mediating between their constituents and the state in periods of legal uncertainty, and the ways that uncertainty has reshaped the social, political and legal environment in which immigrant-serving organizations and their constituents interact. Our research is ongoing, but here we offer our preliminary findings for some of our research questions

Risk of Dementia Associated with Elevated Plasma Homocysteine in a Latin American Population

The relationship between total homocysteine (tHcy) and dementia risk remains controversial, as the association varies among populations and dementia subtypes. We studied a Venezuelan population that has high prevalence of both elevated tHcy and dementia. We tested the hypotheses that (1) elevated tHcy is associated with increased dementia risk, (2) the risk is greater for vascular dementia (VaD) than for Alzheimer's disease (AD), and (3) a history of stroke may partly explain this association. 2100 participants (≥55 years old) of the Maracaibo Aging Study underwent standardized neurological, neuropsychiatric, and cardiovascular assessments. Elevated tHcy was significantly associated with dementia, primarily VaD. When history of stroke and other confounding factors were taken into account, elevated tHcy remained a significant risk factor in older (>66 years), but not in younger (55–66 years) subjects. Ongoing studies of this population may provide insight into the mechanism by which tHcy increases risk for dementia

The Green Bank Ammonia Survey: Unveiling the Dynamics of the Barnard 59 star-forming Clump

Understanding the early stages of star formation is a research field of ongoing development, both theoretically and observationally. In this context, molecular data have been continuously providing observational constraints on the gas dynamics at different excitation conditions and depths in the sources. We have investigated the Barnard 59 core, the only active site of star formation in the Pipe Nebula, to achieve a comprehensive view of the kinematic properties of the source. These information were derived by simultaneously fitting ammonia inversion transition lines (1,1) and (2,2). Our analysis unveils the imprint of protostellar feedback, such as increasing line widths, temperature and turbulent motions in our molecular data. Combined with complementary observations of dust thermal emission, we estimate that the core is gravitationally bound following a virial analysis. If the core is not contracting, another source of internal pressure, most likely the magnetic field, is supporting it against gravitational collapse and limits its star formation efficiency.Comment: 18 pages, 18 figure

Using Situs for the integration of multi-resolution structures

Situs is a modular and widely used software package for the integration of biophysical data across the spatial resolution scales. It has been developed over the last decade with a focus on bridging the resolution gap between atomic structures, coarse-grained models, and volumetric data from low-resolution biophysical origins, such as electron microscopy, tomography, or small-angle scattering. Structural models can be created and refined with various flexible and rigid body docking strategies. The software consists of multiple, stand-alone programs for the format conversion, analysis, visualization, manipulation, and assembly of 3D data sets. The programs have been ported to numerous platforms in both serial and shared memory parallel architectures and can be combined in various ways for specific modeling applications. The modular design facilitates the updating of individual programs and the development of novel application workflows. This review provides an overview of the Situs package as it exists today with an emphasis on functionality and workflows supported by version 2.5

Pandemic grief in El Salvador: factors that predict dysfunctional grief due to a COVID-19 death among Salvadoran adults

Thousands of people have died of COVID-19 in El Salvador. However, little is known about the mental health of those who are mourning the loss of a loved one to COVID-19. Therefore, the objective of this study was to examine the dysfunctional grief associated with COVID-19 death among Salvadoran adults. A sample of 435 Salvadorans (M = 29 years; SD = 8.75) who lost a family member or loved one to COVID-19 completed a digital survey using the Google Forms platform, during April 2 and 28, 2022. The results revealed that 35.1% reported clinically elevated symptoms of dysfunctional grief and among those mourners, and 25.1% also exhibited clinical levels of coronavirus anxiety. A binary logistic regression revealed that predictor variables such as COVID-19 anxiety (p =.003), depression (p =.021), and COVID-19 obsession (p =.032) were significant (χ2 = 84.31; Nagelkerke R2 =.242) and predict a 24.2% chance of dysfunctional bereavement