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The search for cryptic L-Rhamnosyltransferases on the Sporothrix schenckii genome

Hector M. Mora-Montes Karina García-Gutiérrez Laura Cristina García Carnero Nancy Lozoya-Perez Jorge Humberto Ramírez Prado (2022, [Artículo])

The fungal cell wall is an attractive structure to look for new antifungal drug targets and for understanding the host-fungus interaction. Sporothrix schenckii is one of the main causative agents of both human and animal sporotrichosis and currently is the species most studied of the Sporothrix genus. The cell wall of this organism has been previously analyzed, and rhamnoconjugates are signature molecules found on the surface of both mycelia and yeast-like cells. Similar to other reactions where sugars are covalently linked to other sugars, lipids, or proteins, the rhamnosylation process in this organism is expected to involve glycosyltransferases with the ability to transfer rhamnose from a sugar donor to the acceptor molecule, i.e., rhamnosyltransferases. However, no obvious rhamnosyltransferase has thus far been identified within the S. schenckii proteome or genome. Here, using a Hidden Markov Model profile strategy, we found within the S. schenckii genome five putative genes encoding for rhamnosyltransferases. Expression analyses indicated that only two of them, named RHT1 and RHT2, were significantly expressed in yeast-like cells and during interaction with the host. These two genes were heterologously expressed in Escherichia coli, and the purified recombinant proteins showed rhamnosyltransferase activity, dependent on the presence of UDP-rhamnose as a sugar donor. To the best of our knowledge, this is the first report about rhamnosyltransferases in S. schenckii. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

FUNGAL CELL-WALL GLYCANS RHAMNOCONJUGATES RHAMNOSYLTRANSFERASE BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Value chain research and development: The quest for impact

Jason Donovan (2023, [Artículo])

Motivation: For decades, governments, donors, and practitioners have promoted market-based development approaches (MBDA), most recently in the form of value chain development (VCD), to spur economic growth and reduce poverty. Changes in approaches have been shaped by funders, practitioners and researchers in ways that are incompletely appreciated. Purpose: We address the following questions: (1) how have researchers and practitioners shaped discussions on MBDA?; and (2) how has research stimulated practice, and how has practice informed research? We hypothesize that stronger exchange between researchers and practitioners increases the relevance and impact of value chain research and development. Methods and approach: We adopt Downs' (1972) concept of issue-attention cycles, which posits that attention to a particular issue follows a pattern where, first, excitement builds over potential solutions; followed by disenchantment as the inherent complexity, trade-offs, and resources required to solve it become apparent; and consequently attention moves on to a new issue. We review the literature on MBDA to see how far this framing applies. Findings: We identify five cycles of approaches to market-based development over the last 40 or more years: (1) non-traditional agricultural exports; (2) small and medium enterprise development; (3) value chains with a globalization perspective; (4) value chains with an agri-business perspective; and (5) value chain development. The shaping and sequencing of these cycles reflect researchers' tendency to analyse and criticize MBDA, while providing limited guidance on workable improvements; practitioners' reluctance to engage in critical reflection on their programmes; and an institutional and funding environment that encourages new approaches. Policy implications: Future MBDA will benefit from stronger engagement between researchers, practitioners, and funders. Before shifting attention to new concepts and approaches, achievements and failures in previous cycles need to be scrutinized. Evidence-based practice should extend for the length of the issue-attention cycle; preferably it should arrest the cycling of attention. Funders can help by requiring grantees to critically reflect on past action, by providing “safe spaces” for sharing such reflections, and by engaging in joint learning with practitioners and researchers.

Agri-Food Value Chains Issue-Attention Cycles Market-Based Development Approaches CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA VALUE CHAINS PRIVATE SECTOR RURAL DEVELOPMENT SMALLHOLDERS

Development of a thermoelectric test for electrical contactors

PABLO OROZCO CORRAL FRANCISCO JAVIER IBARRA VILLEGAS NOE VILLA VILLASEÑOR (2023, [Artículo])

In the economic model in which we develop, there is a dependence on the means of transport that every day is increasing and due to the importance of electrification in the issue of efficient and clean transportation, has caused the need for companies supplying components for automotive manufacturers to evolve and develop new technologies to stay ahead of the needs of their customers being in full evolution towards electrified transport. This evolution extends not only to manufacturing but to the test methods that currently exist, since automotive standards require suppliers to test in laboratory, the components they sell to their customers to ensure their correct operation.

Electrical contactors Powered thermal cycle endurance Busbars Electrification industry INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

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

La relación entre el crimen y ciclo económico en México: un enfoque espacial

Ricardo Masahiro Solis Ichien (2021, [Tesis de maestría])

En este trabajo se analiza la influencia del ciclo económico sobre los niveles de crimen en México desde el marco conceptual de la teoría de Cantor y Land (1985), los cuales distinguen el efecto de oportunidad y motivación criminal. Se presenta el análisis para el caso mexicano y se evalúa empíricamente el modelo de Cantor y Land para las 32 entidades federativas con datos trimestrales del 2010 a 2019. Utilizando un modelo econométrico que incorpora la interacción espacial en la tasa de crímenes y en el término de error, así como su rezago temporal, al que se le denomina como modelo espacial autorregresivo con errores autorregresivos de orden 1 (SARAR (1,1)) dinámico, se evalúa el modelo para siete tipos de crímenes: homicidios dolosos, secuestros, extorsiones, robo a negocios, robo a casa-habitación, robo de vehículo y robo a transeúnte. Los resultados muestran que se verifica la teoría de Cantor y Land (1985) para cuatro de los siete tipos de delitos. Los robos analizados se caracterizan como robos de necesidad y robos de especialización. Se encuentra evidencia del comportamiento espacial de la actividad criminal donde algunos delitos tienen un efecto regional y otros se concentran.

Crime -- Effect of business cycles on -- Mexico -- Econometric models. Violence -- Effect of business cycles on -- Mexico -- Econometric models. CIENCIAS SOCIALES CIENCIAS SOCIALES

Hacia el desarrollo de un nuevo antiparasitario basado en células en suspensión de Carica papaya

CYNTHIA ALEJANDRA GUZMÁN MEDINA (2023, [Tesis de doctorado])

Las enfermedades parasitarias son un problema de salud pública que afectan a más de la

quinta parte de la población a nivel mundial. Además de la morbilidad que generan, sino

son tratadas y controladas de manera adecuada pueden llegar a causar la muerte.

En el mercado existen diferentes antiparasitarios comerciales, que si bien son efectivos,

presentan diferentes efectos adversos tanto para el individuo parasitado (i.e. destrucción

de la microbiota intestinal) como para el medio ambiente. Este panorama señala la

relevancia de desarrollar tratamientos antiparasitarios más amigables con el ambiente y con

menores efectos adversos que estén disponibles actualmente en el mercado. Productos

obtenidos a partir de plantas con propiedades anti-parasitarias, cultivadas in vitro en

condiciones controladas, podrían representar una alternativa realista. Entre ellas figura la

planta Carica papaya, especie de zonas tropicales y subtropicales del planeta a cuyos frutos

se les adjudica actividades antiparasitarias. Estas propiedades se atribuyen a algunos de

sus compuestos concentrados en el latex y en las semillas como la papaina, la

quimiopapaína, la lisozima, la glicil-endopeptidasa, la proteasa de cisteína y el benzil-

isotiocinato.

El objetivo del presente trabajo fue evaluar la actividad antiparasitaria in vitro e in vivo de

un conjunto de callos y líneas de células de papaya de Carica papaya contra cisticercos de

Taenia crassiceps (cestodo) y contra trofozoitos de Entamoeba histolytica (protozoario). Los

extractos acuosos obtenidos a partir de callos y células cultivados en placa o en suspensión,

respectivamente, de las diferentes líneas de papaya revelaron alta capacidad cisticida

(>98% de mortalidad) in vitro contra cisticercos de Taenia crassiceps. En la evaluación in

vivo la línea no transformada obtuvo mayor efecto cisticida a 10mg/mL reduciendo el

número de cisticercos gemantes y aumentando los cisticercos calcificados en niveles

similares a los obtenidos utilizando antiparasitarios comerciales (albendazol y niclosamida).

Las líneas transformadas y sin transformar de papaya evaluadas indujeron una alta

capacidad amebicida (97% de mortalidad) in vitro contra trofozoitos de Entamoeba

histolytica. Las diferentes líneas transformadas y sin transformar de papaya redujeron

significativamente el número de abscesos amebianos y previnieron la hepatomegalia de

manera no significativamente diferente que el anti-parasitario comercial (metronidazol).

Los resultados generados en el presente estudio señalan al extracto acuoso obtenido a

partir de cultivos en suspensión de células de papaya transformada y no transformada

indujeron alto nivel de protección in vitro e in vivo por lo tanto; este es un producto efectivo

para el tratamiento de la cisticercosis y la amebiasis.

Parasitic diseases are a public health problem that affect more than a fifth of the population

worldwide. Additionally, and along with the morbidity the produce, they can cause death if

they are not treated and controlled adequately.

There are different commercial antiparasitic on the market which, although effective,

present different adverse effects both for the individual (i.e., destruction of the intestinal

microbiota) and for the environment alike. This panorama points out the relevance of

developing more environmentally friendly antiparasitic treatments with fewer adverse effects

than the ones currently available on the market. Products obtained from plants with anti-

parasitic properties, grown in vitro under controlled conditions, could represent a realistic

alternative. Among them is the Carica papaya, a species from tropical and subtropical areas

of the planet whose fruits are believed to have antiparasitic activities. These properties are attributed to some of its compounds concentrated in the latex and seeds such as papain,

chymopapain, lysozyme, glycyl-endopeptidase, cysteine-proteinase and benzyl-

isothiocyanate.

The objective of the present work is to evaluate the in vitro and in vivo antiparasitic activity

of a set of papaya callus and cell lines from Carica papaya against cysticerci of Taenia

crassiceps (cestode) and against trophozoites of Entamoeba histolytica (protozoan). The

aqueous extracts obtained from callus and cells cultured in plates or in suspension,

respectively, of the different papaya lines revealed high cysticidal capacity (>98% mortality)

in vitro against Taenia crassiceps cysticerci. Meanwhile, in the in vivo evaluation, the non-

transformed line obtained a greater cysticidal effect at 10 mg/mL, reducing the number of

budding cysticerci and increasing calcified cysticerci at levels like those obtained using

commercial antiparasitic (albendazole and niclosamide). The papaya lines evaluated

induced a high amoebicidal capacity (97% mortality) in vitro against Entamoeba histolytica

trophozoites. The different papaya lines significantly reduced the number of amoebic

abscesses and prevented hepatomegaly in a non-significantly different manner than the

commercial anti-parasitic (metronidazole).

The results produced in this thesis indicate that the aqueous extract obtained from

suspension cultures of transformed and non-transformed papaya cells induced a high level

of protection in vitro and in vivo. Therefore, this may represent an effective product for the

treatment of cysticercosis and amoebiasis.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS Carica papaya, antiparasitario, células en suspensión, T. crassiceps, E. histolytica. Carica papaya, antiparasitic, in-suspension cells, T. crassiceps, E. histolytica.

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

Efecto del fotoperiodo y la temperatura sobre la composición bioquímica en reproductores silvestres de cabrilla sardinera, Mycteroperca rosacea (Streets, 1877)

Effect of photoperiod and temperature on the biochemical composition in wild broodstock of sardine cabrilla, Mycteroperca rosacea (Streets, 1877)

JOSE ANTONIO ESTRADA GODINEZ MINERVA CONCEPCION MALDONADO GARCIA VICENTE GRACIA LOPEZ Rene Rebollar MILTON ALEJANDRO SPANOPOULOS ZARCO (2014, [Artículo])

"Se estimó el factor de condición (K), el índice gonadosomático (IGS), hepatosomático (IHS) y de grasa visceral (IGV), así como la composición bioquímica en diferentes tejidos de reproductores silvestres de cabrilla sardinera, Mycteroperca rosacea, para evaluarlos a lo largo de un ciclo reproductivo y ver la relación que presentan los cambios con respecto a la temperatura del agua y fotoperiodo de la zona de muestreo. Se capturaron 187 reproductores, 146 hembras y 41 machos en el golfo de California, México. Se observaron diferencias significativas (P < 0,005) en los IGS, IHS e IGV; en el caso de K no se encontraron diferencias. También, se observaron variaciones significativas (P < 0,05) en la mayoría de los parámetros bioquímicos, encontrándose los valores más altos durante la etapa de desove, mientras que los más bajos durante la etapa de reposo. Todos los índices estimados y los parámetros bioquímicos determinados, se correlacionaron significativamente (P < 0,05) con el fotoperiodo, mientras que solo se encontraron correlaciones significativas (P < 0,05) entre el IGS e IGV con respecto a la temperatura del agua."

"Condition factor (K), gonadosomatic index, (IGS), hepatosomatic index (IHS) and fat visceral index (IGV) were estimated and the biochemical composition in different tissues of wild leopard grouper broodstock was determinate too, in order to evaluate them along a reproductive cycle and see the relationship of these changes with respect to the water temperature and photoperiod in the sampling area. 187 brooders were caught, 146 females and 41 males in the Gulf of California, Mexico. Significant differences (P < 0.005) in the IGS, IHS and IGV but not for K were observed. Significant changes (P < 0.05) were also observed in most of the biochemical parameters, being the highest value during the spawning stage, whereas the lowest occurred during the resting stage. Significant correlations (P < 0.05) between all estimated indices and biochemical parameters were observed, while only significant correlations (P < 0.05) between the IGS and IGV with respect to water temperature."

Mycteroperca rosacea, cabrilla sardinera, ciclo reproductivo, composición bioquímica, fotoperiodo, temperatura, golfo de California wavelet sardine, reproductive cycle, biochemical composition, photoperiod, temperature, Gulf of California BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) FISIOLOGÍA ANIMAL FISIOLOGÍA ANIMAL

Maintenance of Coastal Surface Blooms by Surface Temperature Stratification and Wind Drift

MARY CARMEN RUIZ DE LA TORRE (2013, [Artículo])

Algae blooms are an increasingly recurrent phenomenon of potentially socio-economic impact in coastal waters globally and in the coastal upwelling region off northern Baja California, Mexico. In coastal upwelling areas the diurnal wind pattern is directed towards the coast during the day. We regularly found positive Near Surface Temperature Stratification (NSTS), the resulting density stratification is expected to reduce the frictional coupling of the surface layer from deeper waters and allow for its more efficient wind transport. We propose that the net transport of the top layer of approximately 2.7 kilometers per day towards the coast helps maintain surface blooms of slow growing dinoflagellate such as Lingulodinium polyedrum. We measured: near surface stratification with a free-rising CTD profiler, trajectories of drifter buoys with attached thermographs, wind speed and direction, velocity profiles via an Acoustic Doppler Current Profiler, Chlorophyll and cell concentration from water samples and vertical migration using sediment traps. The ADCP and drifter data agree and show noticeable current shear within the first meters of the surface where temperature stratification and high cell densities of L. polyedrum were found during the day. Drifters with 1m depth drogue moved towards the shore, whereas drifters at 3 and 5 m depth showed trajectories parallel or away from shore. A small part of the surface population migrated down to the sea floor during night thus reducing horizontal dispersion. The persistent transport of the surface bloom population towards shore should help maintain the bloom in favorable environmental conditions with high nutrients, but also increasing the potential socioeconomic impact of the blooms. The coast wise transport is not limited to blooms but includes all dissolved and particulate constituents in surface waters. © 2013 Ruiz-de la Torre et al.

chlorophyll, algal bloom, article, cell count, cell density, coastal waters, controlled study, dinoflagellate, Lingulodinium polyedrum, meteorological phenomena, Mexico, near surface temperature stratification, nonhuman, nutrient concentration, popul CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA