Efecto de seis dietas en el crecimiento y supervivencia de poslarvas de abulón rojo (Haliotis rufescens) y su híbrido (H. rufescens ♀ × H. fulgens ♂)

One of the main bottlenecks in abalone aquaculture is maintaining individuals during the weaning stage, when the natural diet changes from diatoms (postlarvae) to macroalgae (juvenile). During this period, abalone pass through profound morphological and physiological changes, which suitable nutrient requirements must sustain. An inadequate diet can result in adverse effects such as late metamorphosis, starvation, slow growth and even death during this phase. Two strategies have been proposed to increase the growth and survival rates of weaning abalone: (i) extending feeding with benthic diatoms and (ii) abalone hybridization via interspecific crosses. To evaluate the efficiency of the two strategies, we assessed the growth and survival rates of postlarvae of pure red abalone (Haliotis rufescens) and a hybrid obtained by crossing red abalone females with green abalone (H. fulgens) males. Both crosses were supplied with six different diets consisting of either one macroalgae mono-diet (Macrocystis pyrifera or Ulva ohnoi) or a mixture with Navicula incerta. Overall, cross-specific diets achieved better growth rates, suggesting that each cross may need specific food items (nutrients) during weaning. Moreover, pure red abalone generally showed the highest growth rates, while the hybrid abalone showed the highest survival rates with most tested diets. Hence, hybrids appear to be better at withstanding stressful conditions, and their use in aquaculture could reduce losses and increase commercial production.   Uno de los principales cuellos de botella en la acuicultura de abulón es el mantenimiento de los individuos durante la fase de destete, cuando la dieta natural cambia de diatomeas (postlarvas) a macroalgas (juveniles). Durante este período, el abulón pasa por profundos cambios morfológicos y fisiológicos, que deben ser sostenidos por una alimentación adecuada. Una dieta inadecuada puede provocar efectos adversos como: metamorfosis tardía, inanición, crecimiento lento e incluso la muerte durante esta fase. Por ello, se han propuesto dos estrategias para aumentar las tasas de crecimiento y supervivencia del abulón durante la fase de destete: (i) ampliar el período de alimentación con diatomeas bentónicas y (ii) la hibridación de abulones mediante cruces interespecíficos. Para determinar la eficacia de ambas estrategias, se evaluaron las tasas de crecimiento y supervivencia de postlarvas de abulón rojo puro (Haliotis rufescens) y de un híbrido obtenido mediante el cruce de hembras de abulón rojo y machos de abulón azul (H. fulgens). A ambos cruces se les suministraron seis dietas diferentes consistentes en una mono dieta de macroalgas (Macrocystis pyrifera, Ulva ohnoi) o en una mezcla con Navicula incerta. En general, con las dietas específicas para cada cruce se obtuvieron mejores tasas de crecimiento, lo que sugiere que cada cruce requiere alimentos (nutrientes) específicos durante el destete. Además, el abulón rojo puro mostró en general las tasas de crecimiento más altas, mientras que en el abulón híbrido se obtuvieron las mayores tasas de supervivencia con la mayoría de las dietas probadas. Por lo que los híbridos parecen soportar mejor las condiciones de estrés, y su uso en la acuicultura podría ayudar a reducir las pérdidas y aumentar su producción comercial

Composición y estructura de la comunidad de moluscos de fondos blandos de la isla Santa Cruz, golfo de California, México

Background. In the marine environment of San Cruz Island, no published references exist regarding the ecology of soft-bottom mollusks. Thus, it is important to carry out research that broadens and deepens the knowledge of this marine area and contributes to proposals of management methods and alternatives for the sustainable use of insular marine resources. Goals. This study seeks to characterize the community composition and structure of soft-bottom mollusks of the infralitoral zone of Santa Cruz Island, and describe some of the characteristics associated with their habitat. Methods. During August 2010, 32 samples were collected: 16 were biological samples and 16 were sediment samples. The composition, abundance, and diversity of the malacological community were analyzed using ecological indexes. Results. 695 individuals were recorded and grouped in two classes: Gastropoda with 446 organisms (5 orders, 11 families, and 19 species); the most abundant species was Siphonaria maura (18%); the class Bivalvia included 249 organisms (8 orders, 14 families, and 25 species); the most abundant species was Tellina eburnea (10%). The Gastropoda class were more abundant than the Bivalvia, i.e., 64.17% and 35% respectively. The species with major abundances and relative frequencies were the gastropods Siphonaria maura (18%) and the bivalve Septifer seteki (69%). Four trophic categories were identified: filterers (73%), herbivores (20%), carnivores (5%), and ectoparasites, the latter of which were the rarest group (2 %). Conclusions. At this site, the specific richness (44 taxa) was lower compared to other sites from different latitudes of the western Gulf of California, likely derived from the higher energy environment of the study area that allowed only juvenile mollusks and micromollusks to be collected.  Antecedentes. Respecto al ambiente marino de la isla Santa Cruz, no existen trabajos publicados de ecología de las especies de moluscos de fondos blandos, por lo que es importante realizar investigaciones que amplíen y profundicen el conocimiento de la zona marina y contribuyan a plantear métodos de manejo y alternativas de uso sustentable de los recursos marinos insulares. Objetivos. El presente trabajo pretende caracterizar la composición y estructura de la comunidad de los moluscos de fondos blandos de la zona infralitoral de la isla Santa Cruz y describir algunas características asociadas con su hábitat. Métodos. En agosto de 2010 se recolectaron 32 muestras, 16 biológicas y 16 de sedimentos. Se analizó la composición, abundancia y diversidad de la comunidad béntica malacológica mediante indicadores ecológicos. Resultados. Se registraron 695 ejemplares agrupados en dos clases, Gastropoda: 446 organismos (cinco órdenes, 11 familias y 19 especies), entre los cuales la especie más abundante fue Siphonaria maura (18%); y Bivalvia: 249 organismos (ocho ordenes, 14 familias y 25 especies), donde la especie más abundante fue Tellina eburnea (10%). La clase Gastropoda fue mayor (64.17%) que Bivalvia (35.82%). Las especies con mayor abundancia y frecuencia relativa fueron el gastrópodo Siphonaria maura (18%) y el bivalvo Septifer zeteki (69%). Se encontraron cuatro categorías tróficas: filtradores (73%), herbívoros (20%), carnívoros (5%) y ectoparásitos (2%). Conclusiones. En este sitio, la riqueza específica (44 taxones) fue menor en comparación con otros sitios de diferente latitud en el golfo de California occidental, posiblemente debido a que la zona de estudio es un ambiente de alta energía donde sólo se encontraron juveniles de moluscos y micromoluscos

Antiproliferative activity of protein extracts from the black clam (Chione fluctifraga) on human cervical and breast cancer cell lines

The wide diversity of the marine environment has been an important resource for the discovery of new bioactive agents from marine organisms. The aim of this study was to obtain protein extracts from the clam Chione fluctifraga and determine its antiproliferative activity against cervical and breast cancer cells. The extracts were obtained by ammonium sulfate fractionation, gel filtration and ion exchange chromatography. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay (MTT). The results showed that 3F3 had antiproliferative effect against HeLa and MDA-MB-231 cell lines with IC50 values of 138.035 and 157.19 μg/ml, respectively, and 2F2 showed IC50 values of 67.46 μg/ml on HeLa cells. These results suggest that protein extracts from C. fluctifraga might be potential anticancer agents.Key words: Protein extracts, clam, antiproliferative activity, breast cancer, cervical cancer

Variación espacial de ensambles de moluscos bentónicos de fondos blandos del archipiélago Espíritu Santo, golfo de California, México

Background. The Espiritu Santo archipelago is recognized for its high biodiversity as a national park. Studies carried out on soft-bottom mollusks are of the faunistic type, and little is known about the variations in their community structure. Objective. To know the composition and the spatial variation in the structure of the assemblages of soft-bottom mollusks of the archipelago and to describe the possible incidence of the type of substrate in their structuring. Methods. In the infralittoral zone, 66 sampling sites were distributed in nine locations. The mollusks were collected by autonomous diving using a 1 m-2 metal frame and a nucleator to analyze of the sediment texture. The medium-grained sand substrate presented the highest distribution. The ecological indices of abundance, species richness (S), Shannon-Wiener diversity (H´), and Pielou evenness index (J´) were estimated. Results. 23,743 individuals were quantified, belonging to 102 species distributed in three classes, 17 orders, 39 families, and 70 genera. The bivalves were represented by 48 species, 9 orders, 17 families, and 39 genera. The gastropods by 52 species, 7 orders, 21 families and 30 genera, and the scaphopods by 1 species. Significant differences were found between localities for species richness and diversity but not for species equity. Conclusions. Spatial variations were observed in the structure of the mollusks assemblages in the archipelago, which could be due to the combined effect of the sediment texture and the presence of mangroves existing in some locations.Antecedentes. El Parque Nacional Archipiélago Espíritu Santo es reconocido por su elevada biodiversidad. Los estudios realizados sobre los moluscos de fondos blandos son inventarios faunísticos, y se conoce poco sobre la variación de su estructura comunitaria. Objetivo. Conocer la composición y la variación espacial en la estructura de los ensambles de moluscos de fondos blandos de este archipiélago y describir la posible relación con el tipo de sustrato. Métodos. En la zona infralitoral se distribuyeron 66 sitios de muestreo en nueve localidades. La colecta de moluscos se realizó mediante buceo autónomo utilizando un marco metálico de 1m2 y para el análisis de la textura del sedimento un nucleador. Se estimaron los indicadores estructurales de abundancia (N), riqueza de especies (S) y los índices de diversidad de Shannon-Wiener (H´) y de Equidad de Pielou (J´). Resultados. El sustrato de arena de grano medio presentó la mayor contribución. Se cuantificaron 23 743 organismos, registrados en 102 especies distribuidas en tres clases, 17 órdenes, 39 familias y 70 géneros. Los bivalvos estuvieron representados por 48 especies, 39 géneros, 17 familias y nueve órdenes. Los gastrópodos por 52 especies, 30 géneros, 21 familias y siete órdenes y los escafópodos por una especie. Se encontraron diferencias significativas entre las localidades para la riqueza de especies y diversidad, pero no para equidad. Conclusiones. Se observaron variaciones espaciales en la estructura de los ensambles de moluscos en el archipiélago, las cuales pudieron ser debidas al efecto combinado de la textura del sedimento y a la presencia de mangles en algunas localidades

Phenology, productivity, and chemical characterization of Jatropha curcas L. as tool for selecting non-toxic elite germplasm

A phenological, physical and chemical descriptive study was carried out on six germplasms of Jatropha curcas L. collected from different areas of Mexico. From these six germplasms, elite germplasms that are better adaptable, with high seed, oil and protein yield, and low levels of phorbol esters were identified. The thermal constant (2570 ± 9) and seed weight (0.695 ± 0.065 g) were similar in all the six germplasms. The average plant height was 1.47 ± 0.25 m after one year of evaluation. Variation in the number of inflorescences (0 to 22) and seed yield (27.35 ± 22.65 g) per plant, and fruit per cluster (2.9 ± 2.2) was considerable. Kernel oil and crude protein contents were 57 ± 3% and 26 ± 2%, respectively. Germplasms India and Isla (Veracruz) had the highest levels of phorbol esters (5.982 and 2.070 mg·g-1, respectively). The reproductive stage and phorbol esters content were critical in selecting elite germplasms. Based on our results, we were able to select three elite germplasms.Key words: Jatropha curcas, elite germplasm, accumulated degree days (ADD), yield, oil, protein, phorbol esters

Plan de comercialización de aguacates San Carlos

Dentro de este proyecto se trabajó con la investigación de oportunidades de negocio para una huerta de aguacate que inició esta nueva administración. En el proyecto se evaluaron diversas opciones de comercialización nacional a través de diversos canales con la finalidad de compartir con la empresa diversos escenarios dependiendo de la capacidad de producción que tenga la huerta una vez que se tenga la primera cosecha. De igual forma se investigaron diversos usos y procesos que se pueden realizar con el aguacate con el fin de buscar la diversificación del producto y poder satisfacer otros mercados. El plan a largo plazo es la exportación del aguacate una vez que la empresa cuente con más experiencia operativa y el capital necesario para así aprovechar la creciente demanda del producto alrededor del mundo.ITESO, A.C

Roadmaps to Utopia: Tales of the Smart City

Notions of the Smart City are pervasive in urban development discourses. Various frameworks for the development of smart cities, often conceptualized as roadmaps, make a number of implicit claims about how smart city projects proceed but the legitimacy of those claims is unclear. This paper begins to address this gap in knowledge. We explore the development of a smart transport application, MotionMap, in the context of a £16M smart city programme taking place in Milton Keynes, UK. We examine how the idealized smart city narrative was locally inflected, and discuss the differences between the narrative and the processes and outcomes observed in Milton Keynes. The research shows that the vision of data-driven efficiency outlined in the roadmaps is not universally compelling, and that different approaches to the sensing and optimization of urban flows have potential for empowering or disempowering different actors. Roadmaps tend to emphasize the importance of delivering quick practical results. However, the benefits observed in Milton Keynes did not come from quick technical fixes but from a smart city narrative that reinforced existing city branding, mobilizing a growing network of actors towards the development of a smart region. Further research is needed to investigate this and other smart city developments, the significance of different smart city narratives, and how power relationships are reinforced and constructed through them

Desgaste profesional y job performance en colaboradores de entidades microfinancieras en la región Junín

Currently, high levels of professional burnout can be observed associated with low levels of performance and, therefore, productivity in various business sectors. The formulated objective was to measure the relationship between professional burnout and work performance in microfinance entities in the Junín region. The research was framed in the guidelines of the quantitative paradigm and in the criteria of a non-experimental-transversal design, of a basic observational type and relational level. The sample was made up of 190 collaborators of microfinance entities in the Junín region. The technique used was the survey, professional burnout was measured using the Maslach exhaustion inventory and to measure work performance the work performance scale was obtained, the data was analyzed with the support of SPSS 25 for Windows. The results show negative connections of -0.224 between professional burnout and job performance with a p-value of 0.027. Therefore, it was concluded that there is a significant negative correlation between professional burnout and work performance in collaborators of microfinance entities in the Junín region.Actualmente puede observarse altos niveles de desgaste profesional asociado a niveles bajos de desempeño y, por tanto, de productividad en diversos sectores empresariales. El objetivo formulado fue medir la relación existente entre desgaste profesional y job performance en entidades microfinancieras de la región Junín. La investigación estuvo enmarcada en los lineamientos del paradigma cuantitativo y en los criterios de un diseño no experimental-transversal, de tipo básico observacional y nivel relacional. La muestra lo conformaron 190 colaboradores de entidades microfinancieras de la región Junín. La técnica empleada fue la encuesta, se midió el desgaste profesional utilizando el inventario de agotamiento de Maslach y para medir job performance se utilizó la escala de desempeño laboral, los datos fueron analizados con el soporte del SPSS 25 para Windows. Los resultados muestran correlación negativa de -0,224 entre desgaste profesional y job performance con un p-valor de 0,027. Por tanto, se concluyó que existe correlación negativa significativa entre desgaste profesional y job performance en colaboradores de entidades microfinancieras de la región Junín