Search results for "ICTE"
showing 10 items of 239 documents
Introduction to the monographic issue “Conflicts in the territory. The evidence of incompatibility between economic growth and sustainability”
2020
El creixement econòmic està produint canvis en el metabolisme social. Les societats cada vegada consumeixen més materials i energia alhora que produeixen més quantitats de deixalles, tot impulsant un desplaçament geogràfic de fonts de recursos i embornals de residus. Això crea impactes que no són resolts per polítiques econòmiques o canvis en la tecnologia, i per tant, cauen desproporcionadament sobre alguns grups socials que moltes vegades protesten i resisteixen, encara que tals grups no sempre es defineixen com a ecologistes (Martínez Alier, 2003). La distribució ecològica es refereix, així, a les asimetries o desigualtats socials, espacials, temporals en l'ús que fan els humans dels rec…
Entrevista a Ernest Garcia i Joan Martínez-Alier: “Per conservar la llibertat hem d’aprendre a deixar de creure en l’abundància i el creixement econò…
2020
El creixement econòmic ha produït canvis en el metabolisme social. L’extracció i ús de recursos naturals i les deixalles, emanacions o residus estan generant cada vegada més conflictes socioambientals i ecològic-distribuïts, tant a escala global com a escala local. Tanmateix, els recursos s’estan exhaurint i cada vegada es fa més evident que la premissa de conciliar creixement econòmic i protecció del medi ambient no és, ni serà, realitzable. Això ha produït canvis i polaritzacions en la consciència col·lectiva. Per una banda, hi ha reaccions del tipus negacionisme extrem i de destrucció ambiental. I, per altra, reaccions de col·lapse. Conversem amb Joan Martínez-Alier, catedràtic i investi…
Responses of Young Peach Trees to Root Confinement
1994
Rooted cuttings of Nemaguard peach [Prunus persica (L.) Batsch.] were grown in 0.18-, 0.36-, 0.90-, and 2.40-liter containers for 16 weeks to study the influence of root confinement on growth, gas exchange, water uptake, and leaf carbohydrate and nutrient content. An automatic nutrient-solution dispensing system was used to ensure uniform fertility among treatments and to prevent drought stress. Leaf area and stem length were reduced by root confinement 6 to 7 weeks after transplanting, and differences among treatments increased throughout the experiment. Final tree dry weights were reduced by 51% over a 13-fold reduction in rooting volume, but dry weight partitioning was largely unaffected…
Maximum likelihood estimation for the exponential power function parameters
1995
This paper addresses the problem of obtaining maximum likelihood estimates for the three parameters of the exponential power function; the information matrix is derived and the covariance matrix is here presented; the regularity conditions which ensure asymptotic normality and efficiency are examined. A numerical investigation is performed for exploring the bias and variance of the maximum likelihood estimates and their dependence on sample size and shape parameter.
An approximation to maximum likelihood estimates in reduced models
1990
SUMMARY An approximation to the maximum likelihood estimates of the parameters in a model can be obtained from the corresponding estimates and information matrices in an extended model, i.e. a model with additional parameters. The approximation is close provided that the data are consistent with the first model. Applications are described to log linear models for discrete data, to models for multivariate normal distributions with special covariance matrices and to mixed discrete-continuous models.
Beyond Pseudo‐natural Products: Sequential Ugi/Pictet‐Spengler Reactions Leading to Steroidal Pyrazinoisoquinolines That Trigger Caspase‐Independent …
2021
In this work, we describe how stereochemically complex polycyclic compounds can be generated by applying a synthetic sequence comprising an intramolecular Ugi reaction followed by a Pictet-Spengler cyclization on steroid-derived scaffolds. The resulting compounds, which combine a fragment derived from a natural product and a scaffold not found in nature. are both structurally distinct and globally similar to natural products at the same time, and interrogate an alternative region of the chemical space. One of the new compounds showed significant antiproliferative activity on HepG2 cells through a caspase-independent cell-death mechanism, an appealing feature when new antitumor compounds are…
Packing meterials with surface barriers, controlled distribution and topography of ligands for sample clean-up and analysis of biologically active so…
1991
Various types of, so-called, restricted access packings have been developed for sample clean-up and analysis of biologically active solutes by means of HPLC. The unique feature of these packings is that they prevent the access of matrix components such as protein whilst selectively retaining the drug components and their metabolites. This results from the fact that the particles of the packings possess a surface barrier for large solutes at the external or internal surface area and exhibit a controlled gradient in the chemical surface composition. They are grouped, according to their particle structures, into internal-surface reversed phases (ISRP), shielded hydrophobic phases (SHP), semi-p…
Anomalous surface diffusion of protons on lipid membranes.
2014
AbstractThe cellular energy machinery depends on the presence and properties of protons at or in the vicinity of lipid membranes. To asses the energetics and mobility of a proton near a membrane, we simulated an excess proton near a solvated DMPC bilayer at 323 K, using a recently developed method to include the Grotthuss proton shuttling mechanism in classical molecular dynamics simulations. We obtained a proton surface affinity of −13.0 ± 0.5 kJ mol−1. The proton interacted strongly with both lipid headgroup and linker carbonyl oxygens. Furthermore, the surface diffusion of the proton was anomalous, with a subdiffusive regime over the first few nanoseconds, followed by a superdiffusive re…
Morphological variation and the recent evolution of wing length in the icterine Warbler: A case of unidirectional introgression?
1999
Icterine Warbler Hippolais icterina and Melodious Warbler H. polyglotta are closely related species with parapatric breeding ranges. Their breeding ranges overlap only in a narrow zone in western Europe, where the Icterine Warbler population is presently declining and the Melodious Warbler population expanding. In eastern Burgundy (France), both species have bred in sympatry for at least forty years, but the Icterine Warbler started to decline in the mid-seventies. The two species differ in wing length and wing formula. Morphological variations of the wing were compared for the Icterine Warbler population in eastern Burgundy between 1965/76 and 1985/96. In the second period, wing length and…
Canopy Architecture Appraisal by Fractal Dimension of 'Flordastar' Peach Trees Grafted onto Different Rootstocks
2007
The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour, by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara, Barrier, GF677 and MrS 2/5 rootstocks. On digital pictures of leafless, dormant peach tree…