Search results for "Berg"

Topics in the geometry of non-Riemannian lie groups

2017

Large Hardy-Weinberg equilibrium deviations in the Daphnia longispina of Lake El Tobar

1995

The population structure of Daphnia longispina in Lake El Tobar, Spain was studied by measuring variation at the aldehyde oxidase (AO), phosphoglucose isomerase (PGI) and phosphoglucose mutase (PGM) loci in each of 1337 individuals from four collections. In 9 of the 12 comparisons between observed allele frequencies and those expected by Hardy-Weinberg equilibrium there was an excess of heterozygotes. We found 27 of the potential number of 54 composite electromorphs (‘clones’) based on the three allozymes. Clone diversities were rather high in all collections. Three clones reached frequencies of over 25% and different clones were dominant in each of the four collections. Strong temporal var…

Calculation of the conformational dependence of valence and Rydberg states in n-tetrasilane

1999

Abstract Previous CIS/6-31G ∗∗ and CASSCF/6-31G ∗ calculations of valence excited states of n -tetrasilane accounted qualitatively for the observed conformational dependence of condensed-phase UV absorption spectra. In an attempt to understand this result, we have performed CIS calculations with a larger basis set (MC-311G(2d) on Si, 6-311G on H, and 2s, 2p, and 2d diffuse orbitals at molecular center of mass). The first two excited states are of valence character at all dihedral angles if the molecule is isolated. When it is embedded in a rare gas cluster, the lowest four states are of valence character, and the results are nearly identical with those obtained without diffuse orbitals in t…

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…

Targeting the vascular endothelial growth factor system to prevent ovarian hyperstimulation syndrome

2008

BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) typically occurs when ovaries are primed with FSH/ LH and subsequently exposed to hCG. The ultimate pathophysiological step underlying this clinical picture is increased vascular permeability (VP). METHODS: A search of the literature was carried out using PubMed and the authors’ files. RESULTS: In rodents and humans, the expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) mRNA increases during ovarian stimulation. With the administration of hCG, the expression of each rises to a maximum. Expression of VEGF/VEGFR-2 mRNAs correlates with enhanced VP, with both peaking 48 h following an injection of hCG. Imm…

A Reassessment of the Therapeutic Potential of a Dopamine Receptor 2 Agonist (D2-AG) in Endometriosis by Comparison against a Standardized Antiangiog…

2021

Dopamine receptor 2 agonists (D2-ags) have been shown to reduce the size of tumors by targeting aberrant angiogenesis in pathological tissue. Because of this, the use of a D2-ag was inferred for endometriosis treatment. When assayed in mouse models however, D2-ags have been shown to cause a shift of the immature vessels towards a more mature phenotype but not a significant reduction in the amount of vascularization and size of lesions. These has raised concerns on whether the antiangiogenic effects of these compounds confer a therapeutic value for endometriosis. In the belief that antiangiogenic effects of D2-ags in endometriosis were masked due to non-optimal timing of pharmacological inte…

Inhibition of KIF20A by BKS0349 reduces endometriotic lesions in a xenograft mouse model

2019

AbstractSeveral studies have suggested a possible etiological association between ovarian endometriosis and ovarian cancer. Evidence has shown that KIF20A overexpression might confer a malignant phenotype to ovarian tumors by promoting proliferation and inhibiting apoptosis. However, no data about the role of KIF20A in endometriosis have been described. In this study, the human endometrium (n = 4) was transfected by mCherry adenovirus and intraperitoneally implanted in mice. Subsequently, mice were divided in three groups (n = 8/group) that were treated with Vehicle, BKS0349 (KIF20A-antagonist) or cabergoline (dopamine receptor agonist) for 21 days. mCherry-labeled endometriotic lesions wer…

Evaluación estandarizada del potencial antiangiógénico del agonista dopaminérgico en el tratamiento de la endometriosis

2018

La endometriosis es una enfermedad crónica, de elevada prevalencia y etiopatogenia no claramente establecida, para la que no se dispone, actualmente, de un tratamiento seguro y eficaz a largo plazo. El establecimiento de la angiogénesis como uno de los requisitos fundamentales en la implantación y desarrollo de la enfermedad ha llevado a considerar los fármacos antiangiogénicos como una potencial diana terapéutica. Estos compuestos han demostrado, en modelos animales, reducir el tamaño de las lesiones endometriales; sin embargo, el uso de estos compuestos en humanos se ve limitado por el intolerable perfil de efectos secundarios que presenta. Los agonistas dopaminérgicos (fármacos con un pe…

Enseñanza de las ciencias : revista de investigación y experiencias didácticas

1996

Resumen basado en el de la publicación Resumen en inglés La evolución histórica del principio de Le Chatelier está relacionada con su uso en el aula de química. La aparente simplicidad en la cual el principio de Le Chatelier fue formulado por primera vez y el éxito logrado en la implementación de algunos procesos industriales importantes le dio un reconocimiento inicial que aún perdura. Sin embargo, desde el comienzo de este siglo, diferentes autores han señalado el carácter limitado de la regla cualitativa y su formulación vaga y ambigua. Además, la termodinámica dada por el Principio de Le Chatelier en algunas formulaciones cuantitativas limitan su aplicabilidad. Sin embargo, la mayoría d…

A Survey of Some Arithmetic Applications of Ergodic Theory in Negative Curvature

2017

This paper is a survey of some arithmetic applications of techniques in the geometry and ergodic theory of negatively curved Riemannian manifolds, focusing on the joint works of the authors. We describe Diophantine approximation results of real numbers by quadratic irrational ones, and we discuss various results on the equidistribution in \(\mathbb{R}\), \(\mathbb{C}\) and in the Heisenberg groups of arithmetically defined points. We explain how these results are consequences of equidistribution and counting properties of common perpendiculars between locally convex subsets in negatively curved orbifolds, proven using dynamical and ergodic properties of their geodesic flows. This exposition…