Autonomous Systems as Legal Agents: Directly by the Recognition of Personhood or Indirectly by the Alchemy of Algorithmic Entities

The clinical manifestations of platelet dense (δ) granule defects are easy bruising, as well as epistaxis and bleeding after delivery, tooth extractions and surgical procedures. The observed symptoms may be explained either by a decreased number of granules or by a defect in the uptake/release of granule contents. We have developed a method to study platelet dense granule storage and release. The uptake of the fluorescent marker, mepacrine, into the platelet dense granule was measured using flow cytometry. The platelet population was identified by the size and binding of a phycoerythrin-conjugated antibody against GPIb. Cells within the discrimination frame were analysed for green (mepacrine) fluorescence. Both resting platelets and platelets previously stimulated with collagen and the thrombin receptor agonist peptide SFLLRN was analysed for mepacrine uptake. By subtracting the value for mepacrine uptake after stimulation from the value for uptake without stimulation for each individual, the platelet dense granule release capacity could be estimated. Whole blood samples from 22 healthy individuals were analysed. Mepacrine incubation without previous stimulation gave mean fluorescence intensity (MFI) values of 83±6 (mean ± 1 SD, range 69–91). The difference in MFI between resting and stimulated platelets was 28±7 (range 17–40). Six members of a family, of whom one had a known δ-storage pool disease, were analysed. The two members (mother and son) who had prolonged bleeding times also had MFI values disparate from the normal population in this analysis. The values of one daughter with mild bleeding problems but a normal bleeding time were in the lower part of the reference interval

The follow-up of patients of sixty-five years of age and younger with acute ischemic stroke and transient ischemic attacks, and elevated D-dimer levels in plasma

D-dimer levels in plasma, a degradation product of fibrin, have been shown to correlate with the severity of ischemic stroke. In order to investigate the outcome of patients with elevated D-dimer we have carried out a follow-up study of patients of 65 years of age and younger with acute ischemic stroke or transient ischemic attacks (TIA) admitted to our stroke unit from 1991 to 1992. Twenty-two of the 57 patients had elevated D-dimer levels in the plasma. High levels were associated with cardioembolic stroke. On follow-up after a mean of 12 years, 15 patients had died and six patients had suffered another stroke or TIA (three of whom were dead). Ten patients had suffered other cardiovascular events and seven of them were dead. We concluded that high levels of D-dimer in acute ischemic stroke patients on admission were associated with cardioembolic stroke and might have prognostic value for the development of further cardioor cerebrovascular events. Advanced age was found to be an independent risk factor

Why Extremes Don't Meet : Le Pen and Besancenot Voters in the 2007 French Presidential Election

Focusing on electoral support for the extreme Left and the extreme Right on the eve of the 2007 French presidential election, this article refutes the "convergence of the extremes" theory. It draws on data from the 2007 CEVIPOF French Electoral Panel to compare the profiles of voters for Jean-Marie Le Pen and Olivier Besancenot. Combining sociological, psycho-political, and economic models for explaining voter choice, it shows how different Le Pen and Besancenot voters are in their partisan and ideological attachments, as well as their social affinities and their positions on candidates and issues. Divergent social and political logics explain the electoral support for these two candidates: their voters do not occupy the same political space, they do not have the same social background, and they do not hold the same values

Targeted disruption of the gene encoding DNA ligase IV leads to lethality in embryonic mice

AbstractDNA ligase IV is the most recently identified member of a family of enzymes joining DNA strand breaks in mammalian cell nuclei [1,2]. The enzyme occurs in a complex with the XRCC4 gene product [3], an interaction mediated via its unique carboxyl terminus [4,5]. Cells lacking XRCC4 are hypersensitive to ionising radiation and defective in V(D)J recombination [3,6], implicating DNA ligase IV in the pathway of nonhomologous end-joining (NHEJ) of DNA double-strand breaks mediated by XRCC4, the Ku70/80 heterodimer and the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) in mammalian cells (reviewed in [7]). The phenotype of a null mutant of the Saccharomyces cerevisiae DNA ligase IV homologue indicates that the enzyme is non-essential and functions in yeast NHEJ [8–10]. Unlike other mammalian DNA ligases for which cDNAs have been characterised, DNA ligase IV is encoded by an intronless gene (LIG4). Here, we show that targeted disruption of LIG4 in the mouse leads to lethality associated with extensive apoptotic cell death in the embryonic central nervous system. Thus, unlike Ku70/80 and DNA-PKcs [11–14], DNA ligase IV has an essential function in early mammalian development

Gradient-dependent inhibition of stimulatory signaling from platelet G protein-coupled receptors

As platelet activation is an irreversible and potentially harmful event, platelet stimulatory signaling must be tightly regulated to ensure the filtering-out of inconsequential fluctuations of agonist concentrations in the vascular milieu. Herein, we show that platelet activation via G protein-coupled receptors is gradient-dependent that is determined not only by agonist concentrations per se but also by how rapidly concentrations change over time. We demonstrate that gradient-dependent inhibition is a common feature of all major platelet stimulatory G protein-coupled receptors, while platelet activation via the non- G protein- coupled receptor glycoprotein VI is strictly concentration-dependent. By systematically characterizing the effects of variations in temporal agonist concentration gradients on different aspects of platelet activation, we demonstrate that gradient-dependent inhibition of protease-activated receptors exhibit different kinetics, with platelet activation occurring at lower agonist gradients for protease-activated receptor 4 than for protease-activated receptor 1, but share a characteristic bimodal effect distribution, as gradient-dependent inhibition increases over a narrow range of gradients, below which aggregation and granule secretion is effectively shut off. In contrast, the effects of gradient-dependent inhibition on platelet activation via adenosine diphosphate and thromboxane receptors increase incrementally over a large range of gradients. Further, depending on the affected activation pathway, gradient- dependent inhibition results in different degrees of refractoriness to subsequent autologous agonist stimulation. Mechanistically, our study identifies an important role for the cyclic adenosine monophosphate-dependent pathway in gradient-dependent inhibition. Together, our findings suggest that gradient-dependent inhibition may represent a new general mechanism for hemostatic regulation in platelets