1,348 research outputs found
Six-fermion production and Higgs boson physics at future colliders
The six-fermion production processes ,
with all the lepton flavours and , relevant to the study of the
intermediate-mass Higgs boson at future linear colliders, are
analysed. A Monte Carlo program, taking into account the whole set of
tree-level scattering amplitudes and the relevant radiative effects, is
developed to provide integrated cross sections and generation of unweighted
events. The complete calculation is compared with the available results of real
Higgs production, and the opportunities of precision studies with event
generation are discussed, demonstrating the relevance of a full six-fermion
calculation. Numerical results for integrated cross sections with various
kinematical cuts and including radiative effects are given and commented. In
the analysis of event samples, several distributions are studied and found to
be sensitive to the presence and to the properties of the Higgs boson.Comment: LaTeX, 27 pages, 13 figures included. Minor changes, final version to
appear in Eur. Phys. J.
At risk policy and early intervention programmes for underperforming students: Ensuring success?
Purpose - The purpose of this paper is to examine a University's at risk program and ask is the intervention strategy working? The program seeks to assist at risk students who may be experiencing difficulties transitioning, for example from school into university. The program also seeks to identify problems and suggest remediation strategies before attrition
The anomaly-free quantization of two-dimensional relativistic string. I
An anomaly-free quantum theory of a relativistic string is constructed in
two-dimensional space-time. The states of the string are found to be similar to
the states of a massless chiral quantum particle. This result is obtained by
generalizing the concept of an ``operator'' in quantum field theory.Comment: LaTeX, 19 pages, no figure
Interactions Between Spermine-Derivatized Tentacle Porphyrins And The Human Telomeric DNA G-Quadruplex
G-rich DNA sequences have the potential to fold into non-canonical G-Quadruplex (GQ) structures implicated in aging and human diseases, notably cancers. Because stabilization of GQs at telomeres and oncogene promoters may prevent cancer, there is an interest in developing small molecules that selectively target GQs. Herein, we investigate the interactions of meso-tetrakis-(4-carboxysperminephenyl)porphyrin (TCPPSpm4) and its Zn(II) derivative (ZnTCPPSpm4) with human telomeric DNA (Tel22) via UV-Vis, circular dichroism (CD), and fluorescence spectroscopies, resonance light scattering (RLS), and fluorescence resonance energy transfer (FRET) assays. UV-Vis titrations reveal binding constants of 4.7 × 10⁶ and 1.4 × 10⁷ M⁻¹ and binding stoichiometry of 2–4:1 and 10–12:1 for TCPPSpm4 and ZnTCPPSpm4, respectively. High stoichiometry is supported by the Job plot data, CD titrations, and RLS data. FRET melting indicates that TCPPSpm4 stabilizes Tel22 by 36 ± 2 °C at 7.5 eq., and that ZnTCPPSpm4 stabilizes Tel22 by 33 ± 2 °C at ~20 eq.; at least 8 eq. of ZnTCPPSpm4 are required to achieve significant stabilization of Tel22, in agreement with its high binding stoichiometry. FRET competition studies show that both porphyrins are mildly selective for human telomeric GQ vs duplex DNA. Spectroscopic studies, combined, point to end-stacking and porphyrin self-association as major binding modes. This work advances our understanding of ligand interactions with GQ DNA
Top-quark physics in six-quark final states at the Next Linear Collider
The processes of six-quark production with one pair are studied by
means of a complete tree-level electroweak calculation. The top-quark signal is
examined: the importance of electroweak backgrounds, of the order of 10% above
the threshold and of about 30% of the purely electroweak signal at
threshold, is further stressed by studying the dependence of the cross-section
at threshold on the Higgs mass in the range between 100 GeV and 185 GeV, and
finding variations of the order of 10%. In the study of some event-shape
variables, a strong effect of initial-state radiation is found, in particular
for the thrust distribution, which is studied for several centre-of-mass
energies at the TeV scale. The effectiveness of cuts on the thrust for
isolating QCD backgrounds, as pointed out by some authors, is confirmed also in
the presence of electroweak backgrounds and initial-state radiation.Comment: LaTeX (using elsart.sty), 17 pages, 9 figures include
ArCo: the Italian Cultural Heritage Knowledge Graph
ArCo is the Italian Cultural Heritage knowledge graph, consisting of a
network of seven vocabularies and 169 million triples about 820 thousand
cultural entities. It is distributed jointly with a SPARQL endpoint, a software
for converting catalogue records to RDF, and a rich suite of documentation
material (testing, evaluation, how-to, examples, etc.). ArCo is based on the
official General Catalogue of the Italian Ministry of Cultural Heritage and
Activities (MiBAC) - and its associated encoding regulations - which collects
and validates the catalogue records of (ideally) all Italian Cultural Heritage
properties (excluding libraries and archives), contributed by CH administrators
from all over Italy. We present its structure, design methods and tools, its
growing community, and delineate its importance, quality, and impact
Lymphocyte Subsets and Inflammatory Cytokines of Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma
Almost all multiple myeloma (MM) cases have been demonstrated to be linked to earlier monoclonal gammopathy of undetermined significance (MGUS). Nevertheless, there are no identified characteristics in the diagnosis of MGUS that have been helpful in differentiating subjects whose cancer may progress to a malignant situation. Regarding malignancy, the role of lymphocyte subsets and cytokines at the beginning of neoplastic diseases is now incontestable. In this review, we have concentrated our attention on the equilibrium between the diverse lymphocyte subsets and the cytokine system and summarized the current state of knowledge, providing an overview of the condition of the entire system in MGUS and MM. In an age where the therapy of neoplastic monoclonal gammopathies largely relies on drugs capable of acting on the immune system (immunomodulants, immunological checkpoint inhibitors, CAR-T), detailed knowledge of the the differences existing in benign and neoplastic forms of gammopathy is the main foundation for the adequate and optimal use of new drugs
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