Eficiencia de distintos métodos de hibridación en cruzamientos de arroz para obtención de líneas puras

Hybridization efficiency of two crossing methods (involving emasculation by hot water or by anther aspiration), was determined in rice. Quantitative comparisons between crossing methods for pure line breeding are scarce and the objectives of this work were to evaluate the advantages and disadvantages of emasculation methods, and to determine an adequate temperature for hot water emasculation. Hot water emasculation at a temperature suitable to each variety (followed by panicle pollination) achieved a higher percentage of hybrid F1 plants (54.6%) than anther aspiration (8.4%), but significantly more seed set was obtained after anther aspiration (31.5%) than after hot water immersion (16.5%). The easiest and quickest emasculation method was the immersion in hot water of panicles from detached rooted tillers.Se determinó la eficiencia de dos métodos de cruzamiento en arroz, implicando emasculación (castración) por agua caliente o por aspiración de anteras. Las comparaciones cuantitativas entre métodos de cruzamiento para obtención de líneas puras son escasas y por ello los principales objetivos de este trabajo fueron evaluar las ventajas y desventajas de ambos métodos de emasculación, así como determinar una temperatura adecuada de castración con agua caliente. La emasculación por agua caliente a una temperatura adecuada para cada variedad (seguida de polinización con panícula) obtuvo un mayor porcentaje de plantas F1 híbridas (54,6%) que la aspiración de anteras (8,4%), pero se obtuvieron significativamente más semillas tras aspiración de anteras (31,5%) que tras inmersión en agua caliente (16,5%). El método más fácil y rápido de emasculación fue la inmersión en agua caliente de las panículas de tallos con raíz, pero separados de la planta madre

Comparación agronómica entre arroz ecológico y arroz biodinámico

Biodynamic agriculture is a type of organic agriculture which has been applied successfully to different crops, including rice. Due to the lack of published studies comparing biodynamic and organic rice, the objective of the present study was to compare the performance of rice (Oryza sativa L.) under these two agronomical methods. Two varieties were transplanted mechanically in Pego-Oliva Natural Park (Alicante, Spain) under continuous flooding, without fertilization or rotation. Grain yield was not significantly different between methods of culture (4,188 vs 4,237 kg ha-1 under organic and biodynamic agriculture, respectively). In our study, grain yield was not significantly different between varieties either (4,228 vs 4,199 kg ha-1for ‘Bomba’ and ‘Albufera’, respectively), but whole grain milling yield was higher in ‘Albufera’ than in ‘Bomba’ (66% vs 55.4%). It is concluded that in these conditions and with these varieties, both methods yield equally.La agricultura biodinámica es un tipo de agricultura ecológica que ha sido utilizada con éxito en varios cultivos, incluyendo arroz. Debido a la falta de estudios publicados que comparen el arroz ecológico con el arroz biodinámico, el objetivo del presente estudio fue comparar el comportamiento del arroz (Oryza sativa L.) bajo estos dos métodos de cultivo. Dos variedades fueron transplantadas mecánicamente en un parque natural de Pego (Alicante, España), bajo riego continuo por inundación, sin fertilizantes ni rotación. La productividad no fue significativamente distinta entre métodos de cultivo (4.188 frente a 4.237 kg ha-1 en cultivo ecológico y biodinámico, respectivamente). En nuestro estudio, no hubo diferencias de productividad de grano entre variedades (4.228 frente a 4.199 kg ha-1 en ‘Bomba’ y ‘Albufera’, respectivamente), pero el rendimiento de granos enteros en molino fue mayor en ‘Albufera’ que en ‘Bomba’ (66% frente a 55.4%). Se concluye que, en estas condiciones y con estas variedades, ambos métodos producen igual

Information transmission around block trades on the Spanish stock exchange

This study investigates the informational effects of large transactions, or Block Trades (BT), in the Spanish Stock Exchange (SSE). In the open market period, this topic was not facilitated in the SSE as it was in other markets until 1998. The SSE thus provides a special environment for analysing the information transmission of these specific transactions. It is assumed that information can be better reflected by changes in true asset value, proxied by the midpoint of bid-ask best quotes. Therefore, we will look at changing true asset value orders instead of trades. Three different effects are studied around BTs: price, liquidity and information transmission. To capture them, three different endogenous variables are considered: true asset returns, relative spreads and adverse selection spread component. With this approach, no clear effects of BTs are found. The main result of the study is that there seems to be an increase in information asymmetries when one looks at the adverse selection spread component in some of the different subsample classifications (buyer, seller and sweeping BT), but there is no significant permanent effect on returns. This result could be related to insiders trading in the market. In sharp contrast with adverse selection evidence, a temporary decrease in bid/ask spread around BTs is also observed. These changes reflect temporary liquidity effects related to other spread components (order processing costs and inventory costs).

Lithium Directs Embryonic Stem Cell Differentiation Into Hemangioblast‐Like Cells

[EN] Definitive hematopoietic stem cells (HSCs) derive from specialized regions of the endothelium known as the hemogenic endothelium (HE) during embryonic developmental processes. This knowledge opens up new possibilities for designing new strategies to obtain HSCs in vitro from pluripotent stem cells (PSCs). Previous advances in this field show that the Wnt/beta-catenin signaling pathway plays a crucial role in PSC-derived HSC formation. In this work, lithium, a GSK3 inhibitor, is identified as an element capable of stabilizing beta-catenin and inducing embryonic stem cells (ESCs) differentiation in hemangioblast-like cells, highly consistent with the role of Wnt agonists on ESC differentiation. ESCs treated with 10 mm lithium express CD31+, SCA-1+, Nkx2-5+, CD34+, and FLK1+ cells characteristic of the hemangioblast cells that precede HE development. However, 10 mm Li treated cells remain arrested in a hemangioblast-like phase, which switched into the expression of HE markers after stimulation with maturation medium. The ability of lithium-treated ESCs to further derive into HE is confirmed after defined maturation, resulting in a rapid increase in cells positive for the HE markers RUNX1 and SOX17. The results represent a novel strategy for generating HSC precursors in vitro as a multipotent source of stem cells for blood disease therapies.P.R. acknowledges support from the Spanish Ministry of Science, Innovation, and Universities (RTI2018-096794), and Fondo Europeo de Desarrollo Regional (FEDER). CIBER-BBN was an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. M.S.-S. acknowledges support from the UK Engineering and Physical Sciences Research Council (EPSRC - EP/P001114/1Mnatsakanyan, H.; Salmerón Sánchez, M.; Rico Tortosa, PM. (2021). Lithium Directs Embryonic Stem Cell Differentiation Into Hemangioblast-Like Cells. Advanced Biosystems. 5(8):1-10. https://doi.org/10.1002/adbi.2020005691105