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Phylogenetic relationships of Pseudo-nitzschia subpacifica (Bacillariophyceae) from the Mexican Pacific, and its production of domoic acid in culture

Sonia Quijano (2020, [Artículo])

Pseudo-nitzschia is a cosmopolitan genus, some species of which can produce domoic acid (DA), a neurotoxin responsible for the Amnesic Shellfish Poisoning (ASP). In this study, we identified P. subpacifica for the first time in Todos Santos Bay and Manzanillo Bay, in the Mexican Pacific using SEM and molecular methods. Isolates from Todos Santos Bay were cultivated under conditions of phosphate sufficiency and deficiency at 16°C and 22°C to evaluate the production of DA. This toxin was detected in the particulate (DAp) and dissolved (DAd) fractions of the cultures during the exponential and stationary phases of growth of the cultures. The highest DA concentration was detected during the exponential phase grown in cells maintained in P-deficient medium at 16°C (1.14 ± 0.08 ng mL-1 DAd and 4.71 ± 1.11 × 10−5 ng cell-1 of DAp). In P-sufficient cultures DA was higher in cells maintained at 16°C (0.25 ± 0.05 ng mL-1 DAd and 9.41 ± 1.23 × 10−7 ng cell-1 of DAp) than in cells cultured at 22°C. Therefore, we confirm that P. subpacifica can produce DA, especially under P-limited conditions that could be associated with extraordinary oceanographic events such as the 2013–2016 "Blob" in the northeastern Pacific Ocean. This event altered local oceanographic conditions and possibly generated the presence of potential harmful species in areas with economic importance on the Mexican Pacific coast. © 2020 Quijano-Scheggia et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

domoic acid, domoic acid, kainic acid, Article, cell growth, controlled study, diatom, Mexico, morphology, nonhuman, Pacific Ocean, phylogeny, plant cell, plant growth, Pseudo nitzschia, toxin analysis, cell culture technique, classification, diatom, CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Thermal and mechanical properties of PLA-based multiscale cellulosic biocomposites

MIGUEL ANGEL RUZ CRUZ Pedro Jesús Herrera Franco Emmanuel Alejandro Flores Johnson MARIA VERONICA MORENO CHULIM LUCIANO MIGUEL GALERA MANZANO Alex Valadez González (2022, [Artículo])

In this work polylactic acid (PLA) based multiscale cellulosic biocomposites were prepared with the aim to evaluate the effect of the incorporation of cellulose nanocrystals (CNCs) on the PLA biocomposites reinforced with cellulose microfibers (MFCs). For this, PLA composite materials reinforced with both MFCs and with a combination of MFCs and CNCs were prepared, while keeping the content of cellulosic reinforcements constant. The thermal and mechanical properties of these multiscale PLA biocomposites were characterized by thermogravimetry (TGA), differential scanning calorimetry (DSC), flexural mechanical and, dynamic mechanical (DMA) tests. Likewise, they were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show that the replacement of MFCs by CNCs in the 1–5% range appreciably modifies the thermal and mechanical properties of multiscale compounds. For example, they increase the thermal stability of the materials, modify the PLA crystallization process and play the role of adhesion promoters since the mechanical properties in flexure increase in the order of 40% and the storage modulus increases in the order of 35% at room temperature. Also, the addition of CNCs increases the relaxation temperature of the material from 50 to 60 °C, thereby expanding the temperature range for its use. © 2022 The Author(s)

MULTISCALE BIOCOMPOSITES CELLULOSE MICROFIBER CELLULOSE NANOCRYSTALS HIERARCHICAL STRUCTURE PROPERTIES INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Propaganda against Mexican women married to Chinese immigrants in Chihuahua 1920-1940

Vladimir Alejandro Armendáriz Romero Jesús Adolfo Trujillo Holguín (2023, [Artículo, Artículo])

At the turn of the 20th century and at the beginning of the new revolutionary government stage in Mexico, the press was an effective way to disseminate propaganda for the nationalist ideology of the State. An important part of this diffusion covered the question of the racial constitution of the mexicans, which led to the need to convince the public that it was important to determine controls over women and with whom they married since they were responsible for the reproduction of the Mexican race. Therefore, a mixture of races considered undesirable, such as the Chinese, was detestable. This propaganda occurred in the context of national anti-Chinese and anti-Jewish campaigns in which they wanted to expel these foreigners on the pretext that their presence and mixing with them would result in degeneration. In Chihuahua there are indications of this propaganda, but also that women married to Chinese resisted this campaign against their families.

Racism gender social control mestizophobia propaganda Racismo género control social mestizofobia HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA

Coinfection and in vitro interaction of Lasiodiplodia pseudotheobromae and Pestalotiopsis mangiferae associated with dieback in branches of mango (Mangifera indica) Manila variety, in Veracruz, Mexico

LILIANA EUNICE SAUCEDO PICAZO Luis Guillermo Hernández Montiel NORMA FLORES ESTEVEZ PATRICIA GEREZ FERNANDEZ ANGEL FERNANDO ARGÜELLO ORTIZ JUAN CARLOS NOA CARRAZANA (2022, [Artículo])

"Dieback disease caused by fungal complexes is a severe problem in mango trees (Mangifera indica). Its main symptoms are branch rot, gummosis, and finally, the tree’s death. In this work, the species of the fungal complex causing mango dieback in the Manila variety in Veracruz, Mexico were identified. The in vitro interaction of two species belonging to the complex was evaluated and the severity of the co-infection in mango branches. Lasiodiplodia pseudotheobromae and Pestalotiopsis mangiferae were identified as causal agents of mango dieback in the producing area of Veracruz. In coinfected mango branches, greater severity of necrosis was observed than in individual infections. Liquid culture filtrates applied in co-cultures showed different results for each species of phytopathogen. The P. mangiferae filtrate had no significant antagonistic effects on the growth of L. pseudotheobromae (inhibition of 2.68%), while the L. pseudotheobromae filtrate inhibited 41.38% of P. mangiferae. The results show that multiple infections in mango trees increase the damage caused by dieback, which could directly impact the development of control strategies."

gummosis, virulence, interaction, fungal complex CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS FITOPATOLOGÍA FITOPATOLOGÍA FITOPATOLOGÍA

Atlas para el manejo de riesgos en grandes obras hidráulicas por efecto de eventos meteorológicos extremos: primera etapa

ISAAC BONOLA ALONSO José Alfredo González Verdugo JOSE RAUL FLORES BERRONES JAVIER AVILES LOPEZ XIANGYUE LI LIU (2011, [Documento de trabajo])

Tabla de contenido: Introducción – Búsqueda y análisis de información – Objetivo del análisis multiespectral – Justificación – Introducción al análisis multiespectral – Metodología – Análisis analógico multiespectral de las imágenes de satélite empleadas – Estructuras volcánicas – Estructuras sedimentarias – Estructuras geomorfológicas sedimentarias – Reología – Reología de la sustancia actuante – Los índices estructurales genéticos de las rocas sedimentarias – Porosidad de las rocas carbonatadas – Deslizamiento de paredes montañosas y de tierras – Conclusiones y recomendaciones – Información relevante recopilada.

Introducción – Búsqueda y análisis de información – Objetivo del análisis multiespectral – Justificación – Introducción al análisis multiespectral – Metodología – Análisis analógico multiespectral de las imágenes de satélite empleadas – Estructuras volcánicas – Estructuras sedimentarias – Estructuras geomorfológicas sedimentarias – Reología – Reología de la sustancia actuante – Los índices estructurales genéticos de las rocas sedimentarias – Porosidad de las rocas carbonatadas – Deslizamiento de paredes montañosas y de tierras – Conclusiones y recomendaciones – Información relevante recopilada.

Construcciones hidráulicas Reología Desastres naturales Factores meteorológicos Informes de proyectos INGENIERÍA Y TECNOLOGÍA

Índices de seguridad hídrica (ISH)

José Manuel Rodríguez Varela Velitchko Tzatchkov Petronilo Edilburgo Cortez Mejía ARIZABETH SAINOS OSCAR JESUS LLAGUNO GUILBERTO LUCIANO SANDOVAL YOVAL DAVID ORTEGA GAUCIN EDGAR YURI MENDOZA CAZARES SALVADOR NAVARRO BARRAZA (2017, [Documento de trabajo])

El objetivo del proyecto fue establecer a nivel municipal índices de seguridad hídrica de accesibilidad y disponibilidad a los servicios de agua potable y saneamiento; seguridad y calidad del agua ante fenómenos de inundaciones, sequías y de contaminación del recurso agua. Para lo cual, con base en una revisión del estado del arte, se identificaron al menos nueve definiciones de seguridad hídrica. Se identificaron varias metodologías internacionales y nacionales para medir la seguridad hídrica, incluyendo la del Programa Nacional Hídrico (PNH) con ocho indicadores en los que se incluyen dos índices. Se decidió trabajar sobre siete indicadores: 1) el índice global de acceso a los servicios básicos de agua (IGASA) del PNH; 2) el índice de vulnerabilidad a la sequía; 3) abatimientos de aguas subterráneas con métodos indirectos, como el experimento de recuperación de gravedad y clima; 4) vulnerabilidad social; 5) indicador municipal de seguridad hídrica; 6) índice global de seguridad hídrica a nivel estatal; y 7) un indicador de gestión del agua. Se analizó la metodología del Índice Global de Seguridad Hídrica, para poder aplicarla, lo cual se hizo a nivel estatal con datos 2015, principalmente de la CONAGUA, así como datos internacionales en la componente de administración.

Seguridad hídrica Factores meteorológicos Ciudades Abastecimiento de agua Calidad del agua CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

In vitro Digestibility of Yarrowia lipolytica Yeast and Growth Performance in Whiteleg Shrimp Litopenaeus vannamei

ANA RUTH ALVAREZ SANCHEZ CLAUDIO HUMBERTO MEJIA RUIZ Héctor Gerardo Nolasco Soria Alberto Peña Rodríguez (2018, [Artículo])

"Marine yeasts used in aquaculture disease control can also be an important protein source for improving feeding and nutrition of crustaceans. Yarrowia lipolyticca has been studied for its capacity to secrete heterologous proteins and high content of unsaturated fatty acids, beta-glucan, and mannane polymers in the cell wall. We measured in vitro digestibility of Y. lipolyticca by whiteleg shrimp Litopenaeus vannamei digestive enzymes, and an in vivo assay of Y. lipolytica in feed onwhiteleg shrimp growth. We found that digestive gland enzymes of shrimp digest Y. lipolytica, based on reduced optical density of a yeast suspension. Digestion was –0.00236 ± 0.00010 OD U min–1 for intact cells and –0.00325 ± 0.00010 OD U min–1 for lysed cells. Release of reducing sugars in intact cells (5.3940 ± 0.1713 μmol h–1), and lysed cells (0.8396 ± 0.2251 μmol h–1) was measured. Digestive gland treatment significantly reduced cell viability (near 100%), relative to the control. Electron microscopy shows that the cell wall of Y. lipolytica exposed to the digestive gland enzymes was severely damaged. Shrimp diet containing Y. lipolytica resulted in significantly higher weight gain and specific growth rate of whiteleg shrimp."

Marine yeast, cell digestibility, cell viability, turbidimetry, reduced sugars BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOQUÍMICA BIOQUÍMICA DE ALIMENTOS BIOQUÍMICA DE ALIMENTOS