530 research outputs found
Scaling of Pseudo-Critical Couplings in Two-Flavour QCD
We study the scaling behaviour of the pseudo-critical couplings for the
chiral phase transition in two-flavour QCD. We show that all existing results
from lattice simulations on lattices with temporal extent , 6 and 8
can be mapped onto a universal scaling curve. The relevant combination of
critical exponents, , is consistent with the scaling behaviour
expected for a second order phase transition with exponents. At present,
scaling according to the symmetry group can, however, not be ruled out.Comment: 8 pages, NSF-ITP 93-12
Imaging of temporomandibular joint: Approach by direct volume rendering
Materials and Methods: We have studied the temporom-andibular joint anatomy, directly on the living, from 3D images obtained by medical imaging Computed Tomography and Nuclear Magnetic Resonance acquisition, and subsequent re-engineering techniques 3D Surface Rendering and Volume Rendering. Data were analysed with the goal of being able to isolate, identify and distinguish the anatomical structures of the joint, and get the largest possible number of information utilizing software for post-processing work.Results: It was possible to reproduce anatomy of the skeletal structures, as well as through acquisitions of Magnetic Resonance Imaging; it was also possible to visualize the vascular, muscular, ligamentous and tendinous components of the articular complex, and also the capsule and the fibrous cartilaginous disc. We managed the Surface Rendering and Volume Rendering, not only to obtain three-dimensional images for colour and for resolution comparable to the usual anatomical preparations, but also a considerable number of anatomical, minuter details, zooming, rotating and cutting the same images with linking, graduating the colour, transparency and opacity from time to time.Conclusion: These results are encouraging to stimulate further studies in other anatomical districts.Background: The purpose of this study was to conduct a morphological analysis of the temporomandibular joint, a highly specialized synovial joint that permits movement and function of the mandible
Neural Stem Cell Regulation, Fibroblast Growth Factors, and the Developmental Origins of Neuropsychiatric Disorders
There is increasing appreciation for the neurodevelopmental underpinnings of many psychiatric disorders. Disorders that begin in childhood such as autism, language disorders or mental retardation as well as adult-onset mental disorders may have origins early in neurodevelopment. Neural stem cells (NSCs) can be defined as self-renewing, multipotent cells that are present in both the embryonic and adult brain. Several recent research findings demonstrate that psychiatric illness may begin with abnormal specification, growth, expansion and differentiation of embryonic NSCs. For example, candidate susceptibility genes for schizophrenia, autism and major depression include the signaling molecule Disrupted In Schizophrenia-1 (DISC-1), the homeodomain gene engrailed-2 (EN-2), and several receptor tyrosine kinases, including brain-derived growth factor and fibroblast growth factors, all of which have been shown to play important roles in NSCs or neuronal precursors. We will discuss here stem cell biology, signaling factors that affect these cells, and the potential contribution of these processes to the etiology of neuropsychiatric disorders. Hypotheses about how some of these factors relate to psychiatric disorders will be reviewed
Cell-to-Cell Adhesion and Neurogenesis in Human Cortical Development: A Study Comparing 2D Monolayers with 3D Organoid Cultures
SUMMARY
Organoids (ORGs) are increasingly used as models of cerebral cortical development. Here, we compared transcriptome and cellular phenotypes
between telencephalic ORGs and monolayers (MONs) generated in parallel from three biologically distinct induced pluripotent
stem cell (iPSC) lines. Multiple readouts revealed increased proliferation in MONs, which was caused by increased integrin signaling.
MONs also exhibited altered radial glia (RG) polarity and suppression of Notch signaling, as well as impaired generation of intermediate
progenitors, outer RG, and cortical neurons, which were all partially reversed by reaggregation of dissociated cells. Network analyses revealed
co-clustering of cell adhesion, Notch-related transcripts and their transcriptional regulators in a module strongly downregulated in
MONs. The data suggest that ORGs, with respect to MONs, initiate more efficient Notch signaling in ventricular RG owing to preserved
cell adhesion, resulting in subsequent generation of intermediate progenitors and outer RG, in a sequence that recapitulates the cortical
ontogenetic process
Immune thrombocytopenia in antiphospholipid syndrome: Is it primary or secondary?
Antiphospholipid syndrome (APS) is frequently associated with thrombocytopenia, in most cases mild and in the absence of major bleedings. In some patients with a confirmed APS diagnosis, secondary immune thrombocytopenia (ITP) may lead to severe thrombocytopenia with consequent major bleeding. At the same time, the presence of antiphospholipid antibodies (aPL) in patients with a diagnosis of primary ITP has been reported in several studies, although with some specific characteristics especially related to the variety of antigenic targets. Even though it does not enter the APS defining criteria, thrombocytopenia should be regarded as a warning sign of a “high risk” APS and thus thoroughly evaluated. The presence of aPL in patients with ITP should be assessed as well to stratify the risk of paradoxical thrombosis. In detail, besides the high hemorrhagic risk in secondary thrombocytopenia, patients with a co-diagnosis of APS or only antibodies are also at risk of arterial and venous thrombosis. In this narrative review, we discuss the correlation between APS and ITP, the mechanisms behind the above-reported entities, in order to support clinicians to define the most appropriate treatment strategy in these patients, especially when anticoagulant or antiplatelet agents may be needed
Computing Multipersistence by Means of Spectral Systems
In their original setting, both spectral sequences and persistent homology are algebraic topology tools defined from filtrations of objects (e.g. topological spaces or simplicial complexes) indexed over the set Z of integer numbers. Recently, generalizations of both concepts have been proposed which originate from a different choice of the set of indices of the filtration, producing the new notions of multipersistence and spectral system. In this paper, we show that these notions are related, generalizing results valid in the case of filtrations over Z. By using this relation and some previous programs for computing spectral systems, we have developed a new module for the Kenzo system computing multipersistence. We also present a new invariant providing information on multifiltrations and applications of our algorithms to spaces of infinite type
Pathological implications of Th1/Th2 cytokine genetic variants in Beh\ue7et's disease: Data from a pilot study in a Sicilian population
Cytokines act as pleiotropic polypeptides able to regulate inflammatory/immune responses and to provide important signals in physiological and pathological processes. Several cytokines (Th1, Th2, and Th17) seem to be involved in the pathophysiology of Beh\ue7et's disease, a chronic immune-mediated disease characterized by oral and genital lesions and ocular inflammation. Its individual susceptibility seems to be modulated by genetic variants in genes codifying these cytokines. Th1 and Th17 seem to be involved in the disease's active phases, and Th2 seems to affect the development or severity of the disease; however, contrasting data are reported. In this study, some genetic variants of the Th1/Th2 cytokine genes were investigated in Sicilian patients and age- and gender-matched controls. Three very significant associations with Beh\ue7et's disease were detected, and combined genotypes associated with increased disease risk were identified. Results obtained point to the key role of Th1/Th2 cytokine genetic variants in disease susceptibility
Numerical Evidence for the Observation of a Scalar Glueball
We compute from lattice QCD in the valence (quenched) approximation the
partial decay widths of the lightest scalar glueball to pairs of pseudoscalar
quark-antiquark states. These predictions and values obtained earlier for the
scalar glueball's mass are in good agreement with the observed properties of
and inconsistent with all other observed meson resonances.Comment: 12 pages of Latex, 3 PostsScript figures as separate uufil
- …