Structure, morphogenesis and patterns of defoliation of Brachiaria decumbens Stapf. pastures

This study aimed to contribute to the understanding o f the morphogenesis and structure of signal grass (Brachiaria decumbens Stapf.) pastures, and how they are affected by the environment and cattle defoliation. A diagrammatic model was adopted to identify and relate the major morphogenetic and structural characteristics at different levels of organisation o f the sward: phytomer, tiller, plant and population. The morphogenetic characteristics studied were leaf elongation rate (LER), intemode elongation rate (IER), leaf senescence rate (LSR), leaf appearance rate (LAR), tiller birth rate (TBR) and tiller death rate (TDR). The structural characteristics analysed were length of phytomer components (blade, sheath and internode), number o f phytomers per tiller, total length and number o f live blades per tiller, number and size-age distributions o f tillers per plant, and number and size distribution o f plants and tillers per area. Experiments to analyse the effects o f temperature, nitrogen application, season and defoliation intensity on sward structural and morphogenetic variables were performed under controlled and field conditions, and using destructive and non-destructive measurements.An initial experiment under controlled environments showed highest LAR, LER and IER values at 30°C, and strong mutual regulations between morphogenetic and structural characteristics at the phytomer and tiller levels. The effects of cattle grazing and nitrogen fertilisation on the dynamics o f signal grass morphology, and the patterns o f defoliation were monitored during one year in long established pastures in Santa Cruz, Bolivia. Plant and population demography were mainly determined by the season: high number of seedlings and new vegetative tillers at the beginning o f summer; new vegetative tillers, plant fragmentation, and flowering during summer (wet season); and low tiller and plant densities with low proportions o f live leaf towards the following winter. Defoliation affected the phytomer and tiller levels of sward organisation, mainly through increases in the population o f young tillers. All morphogenetic characteristics were mainly affected by season, with higher values during summer. LSR, IER and LAR were partly regulated by tiller size or age characteristics, while TBR and TDR were directly affected by the intensity of defoliation. During winter, soil water availability affected tiller growth more than temperature. The low doses o f nitrogen applied in the field were effective in increasing LER and TBR after short spells at the end o f winter, but not during the main growing season. Tillers o f signal grass showed very high turnover rates, mainly because o f their pattern o f growth with intemode elongation, the production o f weak aerial tillers, and the speed in developing flowers during the reproductive season. The pattern o f defoliation by cattle was best explained at the tiller level, due to the sward heterogeneity in tiller structure and the physical barrier imposed by the tiller stem.A conceptual model integrating the information obtained from the experiments was developed as a synthesis for discussion. The applicability o f information on sward morphogenesis and structure as a pasture management decision support tool, especially in the diagnosis o f pasture degradation is finally considered

Potencial territorial de Cantabria para la producción de leche de bovino en base a pasto

Cantabria es un territorio eminentemente ganadero, en el que destacan la relevancia del bovino y los pastos. En las últimas décadas, el sector ganadero está inmerso en un proceso de ajuste estructural, dando como resultado una reducción de las explotaciones, elevación de la dimensión e intensificación productiva. Esta reconfiguración del sector, unido a la demanda creciente de productos de mayor calidad y respetuosos con el medio ambiente, hacen que el objetivo de este trabajo sea analizar el potencial territorial de Cantabria para producir leche en base a pasto, a partir de información productiva y territorial de 99 ganaderías. Se recurre a un análisis de regresión lineal múltiple, capaz de estimar el porcentaje de forraje verde en la dieta (pasto/no pasto) a partir de 41 variables territoriales. El modelo seleccionado, incluye 4 variables (superficie pastos; % superficie pastos; densidad de borde; índice de forma del paisaje) y que tiene un porcentaje de acierto del 70,1%. Los resultados apuntan que el 33% de las ganaderías producen leche en base a pasto, de los cuales la mitad lo hace en condiciones territoriales adaptadas al sistema; además hay un 12% que tiene potencial para producir y no lo hace

Mussel-inspired lego approach for controlling the wettability of surfaces with colorless coatings

The control of surface wettability with polyphenol coatings has been at the forefront of materials research since the late 1990s, when robust underwater adhesion was linked to the presence of L-DOPA-a catecholic amino acid-in unusually high amounts, in the sequences of several mussel foot proteins. Since then, several successful approaches have been reported, although a common undesired feature of most of them is the presence of a remnant color and/or the intrinsic difficulty in fine-tuning and controlling the hydrophobic character. We report here a new family of functional catechol-based coatings, grounded in the oxidative condensation of readily available pyrocatechol and thiol-capped functional moieties. The presence of at least two additional thiol groups in their structure allows for polymerization through the formation of disulfide bonds. The synthetic flexibility, together with its modular character, allowed us to: (I) develop coatings with applications exemplified by textiles for oil-spill water treatment; (II) develop multifunctional coatings, and (III) fine-tune the WCA for flat and textile surfaces. All of this was achieved with the application of colorless coating

Mussel-Inspired Lego Approach for Controlling the Wettability of Surfaces with Colorless Coatings

The control of surface wettability with polyphenol coatings has been at the forefront of materials research since the late 1990s, when robust underwater adhesion was linked to the presence of L-DOPA—a catecholic amino acid—in unusually high amounts, in the sequences of several mussel foot proteins. Since then, several successful approaches have been reported, although a common undesired feature of most of them is the presence of a remnant color and/or the intrinsic difficulty in fine-tuning and controlling the hydrophobic character. We report here a new family of functional catechol-based coatings, grounded in the oxidative condensation of readily available pyrocatechol and thiol-capped functional moieties. The presence of at least two additional thiol groups in their structure allows for polymerization through the formation of disulfide bonds. The synthetic flexibility, together with its modular character, allowed us to: (I) develop coatings with applications exemplified by textiles for oil-spill water treatment; (II) develop multifunctional coatings, and (III) fine-tune the WCA for flat and textile surfaces. All of this was achieved with the application of colorless coatings.Fil: Casagualda, Carolina. Universitat Autònoma de Barcelona; EspañaFil: Mancebo Aracil, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universitat Autònoma de Barcelona; EspañaFil: Moreno Villaecija, Miguel Angel. Universitat Autònoma de Barcelona; EspañaFil: López Moral, Alba. Universitat Autònoma de Barcelona; EspañaFil: Alibés, Ramon. Universitat Autònoma de Barcelona; EspañaFil: Busqué, Félix. Universitat Autònoma de Barcelona; EspañaFil: Ruiz Molina, Daniel. Universitat Autònoma de Barcelona; Españ

Caracterización productiva y territorial de las ganaderías de bovino de leche en Cantabria, según el contenido de forraje verde en la dieta (póster)

En los últimos años, están apareciendo en el mercado leche en la que se indica “de pastoreo” o “de pasto”, debido al interés creciente de la sociedad hacia productos más saludables y respetuosos con el medioambiente. El objetivo de este trabajo es profundizar en la relación entre las características territoriales de las ganaderías de bovino de leche y su manejo alimentario. Se clasificaron 99 ganaderías en función del porcentaje de forraje verde (FV) en la dieta -de primavera- de las vacas en lactación (No pasto <25% FV; Pasto ≥25% FV). Como variables se incluyeron el porcentaje de materia seca de los distintos componentes de la dieta, las principales características productivas y la información territorial contenida en la base de datos oficial SIA (Sistema integrado de ayudas) para 41 variables territoriales. Las ganaderías pertenecientes al modelo en base a pasto (≥25% FV) constituyen el 33% y presentan una menor dimensión productiva, carga ganadera y consumo de concentrado, con una mayor dedicación al pastoreo. Además, presentan mayor altitud de las parcelas, parcelas de mayor dimensión, más homogéneas y con mejor geometría, pero también un suelo de baja capacidad de uso agrícola. Este trabajo abre la posibilidad a analizar el potencial productivo y territorial de Cantabria para la producción de leche en base a pasto, como estrategia de valorización de los sistemas extensivos de producción de leche ligada al territorio

Bioinspired Functional Catechol Derivatives through Simple Thiol Conjugate Addition

The combination of the surface-adhesive properties of catechol rings and functional moieties conveying specific properties is very appealing to materials chemistry, but the preparation of catechol derivatives often requires elaborate synthetic routes to circumvent the intrinsic reactivity of the catechol ring. In this work, functional catechols are synthesized straightforwardly by using the bioinspired reaction of several functional thiols with o-benzoquinone. With one exception, the conjugated addition of the thiol takes place regioselectively at the 3-position of the quinone, and is rationalized by DFT calculations. Overall, this synthetic methodology provides a general and straightforward access to functional and chain-extended catechol derivatives, which are later tested with regard to their hydro-/oleophobicity, colloidal stability, fluorescence, and metal-coordinating capabilities in proof-of-concept applications