Speciation by hybridization is emerging as a significant contributor to biological diversification. Yet, little is known about the relative contributions of (i) evolutionary novelty and (ii) sorting of pre-existing parental incompatibilities to the build-up of reproductive isolation under this mode of speciation. Few studies have addressed empirically whether hybrid animal taxa are intrinsically i

Calcium channels must be subjected to a very precise regulation in order to preserve cell function and viability. Voltage gated calcium channels (VGCC) represent the main pathway for calcium entry in excitable cells. This explains why depolarization induces a rapid-onset and short-term inactivation of calcium currents. Contrarily to this well-documented mechanism to maintain calcium below toxic le

During the stress response adrenal medullary chromaffin cells release catecholamines to the bloodstream. Voltage-activated calcium channels present in the cell membrane play a crucial role in this process. Although the electrophysiological and pharmacological properties of chromaffin cell calcium channels have been studied in detail, the molecular composition of these channels has not been defined

Apoptosis is an active process that is regulated by different signalling pathways. One of the more important organelles involved in apoptosis regulation is the mitochondrion. Electron chain transport disruption increases free radical production leading to multiple conductance channel opening, release of cytochrome c and caspase activation. This death pathway can be blocked by anti-apoptotic member

1. Mitochondrial mechanisms involved in veratridine-induced chromaffin cell death have been explored. 2. Exposure to veratridine (30 micro M, 1 h) produces cytochrome c release to the cytoplasm that seems to be mediated by superoxide anions and that is blocked by cyclosporin A (10 micro M), MnTBAP (10 nM), catalase (100 IU ml(-1)) and vitamin E (50 micro M). 3. Following veratridine treatment, the

An industrial model of a dynamic system is usually not just a set of differential equations. External inputs acting on the system are common, such as an external force acting on a body or wind pressing on a car. Update of these inputs needs to be handled by the numerical solver in an efficient way.In dynamical simulation, multistep methods are commonly used. A multistep method uses the solution hi

PURPOSE: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive forms of cancer with no curative therapies available. To date, strategies to target ATC by immunotherapy have not been evaluated. We investigated whether ATC would be a suitable target for natural killer (NK) cell-based immunotherapy.EXPERIMENTAL DESIGN: We first established seven new cell lines from ATC tumors, three from p

Upon activation, platelets release plasma-membrane derived microparticles (PMPs) exposing phosphatidylserine (PS) on their surface. The function and clearance mechanism of these MPs are incompletely understood. As they are pro-coagulant and potentially pro-inflammatory, rapid clearance from the circulation is essential for prevention of thrombotic diseases. The tyrosine kinase receptors Tyro3, Axl

Acute lymphoblastic leukemia (ALL) is the commonest childhood malignancy and is characterized by recurring structural genetic alterations. Previous studies of DNA methylation suggest epigenetic alterations may also be important, but an integrated genome-wide analysis of genetic and epigenetic alterations in ALL has not been performed. We analyzed 137 B-lineage and 30 T-lineage childhood ALL cases

BackgroundPostzygotic isolation in the form of reduced viability and/or fertility of hybrids may help maintain species boundaries in the face of interspecific gene flow. Past hybridization events between house sparrows (Passer domesticus) and Spanish sparrows (P. hispaniolensis) have given rise to a homoploid hybrid species, the Italian sparrow (P. italiae). Although genetic incompatibilities are

We compared the influence of the microbial community composition and the environmental conditions for the functioning - microbial growth and respiration - and trait distribution - bacterial pH tolerance - of soil microorganisms across a pH gradient. Sterilised soil microcosms, including pH 4.1, 5.2, 6.7 and 8.3, with added plant litter were inoculated with unsterilized soil in a factorial design a

We consider 5-dimensional Lie groups equipped with a left-invariant Riemannian metric. On such groups we construct left-invariant conformal foliations with minimal leaves of codimension 2. These foliations produce complex-valued harmonic morphisms locally defined on the Lie group.

This paper presents a theoretical analysis of the neoliberal production of anxiety in academic faculty members in universities in Northern Europe. The paper focuses on neoliberalization as it is instantiated through audit and ranking systems designed to produce academia as a space of economic efficiency and intensifying competition. We suggest that powerful forms of competition and ranking of acad

Mohammad Reza Pahlavi, the Shah of Iran, was toppled in the Islamic Revolution of 1979. A year later he passed away from lymphoma, a disease he had secretly battled for several years, but still it remains unknown exactly when he was diagnosed with cancer, if he was aware of his condition and who close to him knew about his illness. Following his 1979 exile from Iran, physicians from numerous count