221 research outputs found
The Nuclear Science References (NSR) Database and Web Retrieval System
The Nuclear Science References (NSR) database together with its associated
Web interface, is the world's only comprehensive source of easily accessible
low- and intermediate-energy nuclear physics bibliographic information for more
than 200,000 articles since the beginning of nuclear science. The
weekly-updated NSR database provides essential support for nuclear data
evaluation, compilation and research activities. The principles of the database
and Web application development and maintenance are described. Examples of
nuclear structure, reaction and decay applications are specifically included.
The complete NSR database is freely available at the websites of the National
Nuclear Data Center http://www.nndc.bnl.gov/nsr and the International Atomic
Energy Agency http://www-nds.iaea.org/nsr.Comment: 16 pages, 5 figure
Applicability of the orientation average formula in heavy-ion fusion reactions of deformed nuclei
In heavy-ion fusion reactions involving a well deformed nucleus, one often
assumes that the orientation of the target nucleus does not change during the
reaction. We discuss the accuracy of this procedure by analyzing the excitation
function of the fusion cross section and the fusion barrier distribution in the
reactions of Sm target with various projectiles ranging from C
to Ar. It is shown that the approximation gradually looses its accuracy
with increasing charge product of the projectile and target nuclei because of
the effects of finite excitation energy of the target nucleus. The relevance of
such inaccuracy in analyzing the experimental data is also discussed.Comment: 5 pages and 3 figure
The Generalized Liquid Drop Model Alpha-Decay Formula: Predictability Analysis and Super-Heavy Element Alpha Half-Lives
The predictive accuracy of the generalized liquid drop model (GLDM) formula
for alpha decay half-lives has been investigated in a detailed manner and a
variant of the formula with improved coefficients is proposed. The method
employs the experimental alpha half-lives of the well-known alpha standards
(REFERENCE) to obtain the coefficients of the analytical formula using the
experimental Qalpha values (the DSR-E formula), as well as the finite range
droplet model (FRDM) derived Qalpha values (the FRDMFRDM formula). The
predictive accuracy of these formulae were checked against the experimental
alpha half-lives of an independent set of nuclei (TEST) that span approximately
the same Z,A region as the standards and possess reliable alpha spectroscopic
data, and were found to yield good results for the DSR-E formula but not for
the FRDM-FRDM formula. The two formulae were used to obtain the alpha
half-lives of super-heavy (SHE) and heavy nuclides where the relative accuracy
was found to markedly improve for the FRDM-FRDM, which corroborates the
appropriateness of the FRDM masses and the GLDM prescription for high Z,A
nuclides. Further improvement resulted, especially for the FRDM-FRDM formula,
after a simple linear optimization over the calculated and experimental
half-lives of TEST was used to re-calculate the half-lives of the SHE and heavy
nuclides. The advantage of this optimization was that it required no
recalculation of the coefficients of the basic DSR-E or FRDM-FRDM formulae. The
halflives for 324 medium-mass to super-heavy alpha decaying nuclides,
calculated using these formulae and the comparison with experimental
half-lives, are presented.Comment: 61 pages, 6 figures, PDF file, to appear in Atomic Data and Nuclear
Data Table
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice
More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease
Manipulation of the fatty acids composition of poultry meat and giblets by dietary inclusion of two oil sources and conjugated linoleic acid
Sa‘īd b. Ḥasan, biographical notes through the prism of Masālik al-Naẓar
The Islamic polemical tract Kitāb Masālik al-Naẓar reveals much about its author, the Jewish apostate Sa‘īd b. Ḥasan. Sa‘īd plunges into diverse polemic themes, including some with which he is poorly acquainted, and uses sources from all three Abrahamic faiths, showing greater familiarity with Jewish sources than with the Qur’ān. The discussion explores Sa‘īd’s treatment of various issues in Muslim-Jewish polemics through the prism of his important polemical tract, Masālik al-Naẓar, and takes one of the first steps toward lifting Sa‘īd out of his undeserved obscurity in scholarship
Designing a broad-spectrum integrative approach for cancer prevention and treatment
Targeted therapies and the consequent adoption of "personalized" oncology have achieved notablesuccesses in some cancers; however, significant problems remain with this approach. Many targetedtherapies are highly toxic, costs are extremely high, and most patients experience relapse after a fewdisease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistantimmortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are notreliant upon the same mechanisms as those which have been targeted). To address these limitations, aninternational task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspectsof relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a widerange of high-priority targets (74 in total) that could be modified to improve patient outcomes. For thesetargets, corresponding low-toxicity therapeutic approaches were then suggested, many of which werephytochemicals. Proposed actions on each target and all of the approaches were further reviewed forknown effects on other hallmark areas and the tumor microenvironment. Potential contrary or procar-cinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixedevidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of therelationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. Thisnovel approach has potential to be relatively inexpensive, it should help us address stages and types ofcancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for futureresearch is offered
Limits on the production of scalar leptoquarks from Z (0) decays at LEP
A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)
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