Search results for "SELE"
showing 10 items of 4721 documents
Limited effects of size-selective harvesting and harvesting-induced life-history changes on the temporal variability of biomass dynamics in complex f…
2023
Harvesting has been implicated in destabilizing the abundances of exploited populations. Because selective harvesting often targets large individuals, some studies have proposed that exploited populations often experience demographic shifts toward younger, smaller individuals and become more sensitive to environmental fluctuations. The theory of consumer–resource dynamics has been applied to address the impacts of harvesting in simple modular food webs, but harvested populations are embedded in a complex food web in nature. In addition, exploited populations have been shown to undergo trait evolution or phenotypic changes toward early maturation at smaller sizes. Using an empirically derive…
A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments
2020
Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from descriptive studies to modeling approaches of varying complexity. Increasingly, isotope tracer data are being used to compare ecosystems and analyze experimental manipulations. Currently, a formal statistical framework for analyzing such experiments is lacking, making it impossible to calculate the estimation errors associated with the model fit, the…
Zastosowanie ekstrakcji i technik membranowych do rozdziału stereoizomerów aminokwasów i ich pochodnych
2004
Derivatives of amino acids are known from their great biological relevance, for example can be used as pharmaceuticals, crop protection substances or food additives. In significant number of cases such substances show their biological potency only as single enantiomer. Therefore, one of the most important conditions during their production is to ensure their high optical purity. Generally, two routes to accomplish this goal are considered to be most effective. The first one is to synthesize enantiomers with the support of chiral catalyst introduced into the reaction mixture. The second approach involves the preparation of racemic mixture and in final step to separate it into single enantiom…
Elecciones primarias abiertas en el Partido Socialista Francés 2011: votan afiliados y simpatizantes.
2014
Elecciones primarias abiertas en el Partido Socialista Francés. 2011 1.- El modelo francés de 2011. Primarias a la francesa: votan afiliados y simpatizantes. 2.- Una experiencia inédita en Francia: los socialistas abren la elección de su candidato a la Presidencia de la Republica a los simpatizantes de la izquierda. Octubre de 2011. 3.- Los candidatos. 4.-Riesgos. Participación y voto adversario. 5.- ¿Quien podía votar en las primarias? Participar por un euro y adherirse a los valores de la izquierda y de la República. "Me reconozco en los valores de la izquierda y de la República, en el proyecto de una sociedad de libertad, igualdad, fraternidad, el laicismo, la justicia la solidaridad y e…
Validación clínica de la cinematografía como nuevo método de selección embrionaria
2017
El objetivo de la presente tesis es la validación clínica del cultivo y selección embrionaria mediante análisis morfocinético. La tesis ha sido elaborada en la modalidad de compendio de publicaciones, siendo los siguientes los que la constituyen. En primer lugar se incluye una detallada revisión de la tecnología time-lapse (publicaciones previas al respecto, tecnología disponible, resultados obtenidos hasta la fecha por diferentes grupos y modelos de selección propuestos). A continuación se explica el modelo de selección desarrollado por nuestro grupo, prestando especial interés a uno de los factores de exclusión, de gran relevancia. En tercer lugar consta un trabajo en el que se realizó un…
Recent developments and applications of the chiral Brønsted acid catalyzed allylboration of carbonyl compounds
2018
The 50-year-old allylboration reaction has seen dramatic developments since the dawn of the new century after the first catalytic asymmetric versions came into play. In the past decade alone, several methodologies capable of achieving the desired homoallylic alcohols in over 90% ee have been developed. This review focuses on the chiral Brønsted acid catalyzed allylboration reaction, covering everything from the very first examples and precedents to modern day variations and applications.1 Introduction2 Early Developments3 Synthetic Applications4 Variants5 Computational Contribution6 Conclusions
Mapping a-priori defined plant associations using remotely sensed vegetation characteristics
2014
Abstract Incorporation of a priori defined plant associations into remote sensing products is a major challenge that has only recently been confronted by the remote sensing community. We present an approach to map the spatial distribution of such associations by using plant indicator values (IVs) for salinity, moisture and nutrients as an intermediate between spectral reflectance and association occurrences. For a 12 km 2 study site in the Netherlands, the relations between observed IVs at local vegetation plots and visible and near-infrared (VNIR) and short-wave infrared (SWIR) airborne reflectance data were modelled using Gaussian Process Regression (GPR) (R 2 0.73, 0.64 and 0.76 for sali…
Stereoselective Synthesis and Pharmacological Evaluation of 2,4-Bridged Piperidine Derivatives Designed to Activate the κ-Opioid Receptor
2021
Germinal center B cells govern their own fate via antibody feedback
2013
High-affinity antibodies reenter germinal centers (GCs) and limit antigen access, thus causing sustained directional evolution in GCs toward higher-affinity antibody production.
Selective chiral inhibition of Ca2+ entry promoted by bisbenzyltetrahydroisoquinolines in rat uterus.
1992
Abstract The effects of diltiazem and six bisbenzyltetrahydroisoquinoline alkaloids (antioquine, 7-O-methylantioquine, dimethylantioquine, monterine, granjine and cordobimine) were studied in rat isolated uterus in order to clarify the mechanisms of their relaxant actions. All the compounds tested completely relaxed KCl-induced contractions and totally or partially inhibited oxytocin-induced rhythmic contractions. Only alkaloids with absolute configurations (1R,1′S or 1R,1′R) acted intracellularly, promoting relaxation of contractile responses induced by oxytocin in a Ca2+-free medium, as does papaverine. Alkaloids of the antioquine series (1S,1′R) selectively inhibited Ca2+ entry. The grea…