2,766 research outputs found
Results from RHIC with Implications for LHC
Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are
reviewed from the perspective of measurements in p-p collisions at the CERN-ISR
which serve as a basis for many of the techniques used. Issues such as J/Psi
suppression and hydrodynamical flow in A+A collisions require data from
LHC-Ions for an improved understanding. Suppression of high pT particles in
Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as
the equality of the suppression of inclusive pi0 (from light quarks and gluons)
and direct-single electrons (from the decay of heavy quarks) in the transverse
momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of
suppression and leads to a fundamental question of whether the Higgs boson
gives mass to fermions. Observation of an exponential distribution of direct
photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are
negligible and with no similar exponential distribution in p-p collisions
indicates thermal photon emission from the medium at RHIC, making PHENIX at the
moment ``the hottest experiment in Physics''.Comment: Invited lectures at the International School of Subnuclear Physics,
47th Course, "The most unexpected at LHC and the status of High Energy
Frontier'', Erice, Sicily, Italy, August 29-September 7. 2009. 32 pages, 22
figure
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A search for chargino-neutralino production at the Fermilab Tevatron Collider
We have searched for evidence of supersymmetry with the Collider Detector at Fermilab using trilepton events in p{anti p} collisions at {radical}s = 1.8 TeV. In the Minimal Supersymmetric Standard Model (MSSM), we expect trilepton events from chargino-neutralino ({tilde {xi}}{sup {+-}}{sub 1}{tilde {xi}}{sup 0}{sub 2}) pair production, with subsequent decay into leptons. In all possible combinations of electron and muon channels, we observe no candidate events in 107 pb{sup -1} of data. We present limits on chargino and neutralino production within the framework of a supergravity inspired MSSM: {sigma}{sub {tilde {xi}}{sup {+-}}{sub 1}{tilde {xi}}{sup 0}{sub 2}} {center_dot} BR({tilde {xi}}{sup {+-}}{sub 1}{tilde {xi}}{sup 0}{sub 2} {yields} 3l + X) 81.5 GeV/c{sup 2} for tan {beta} = 2, {mu} = -600 GeV/c{sup 2} and M{sub {tilde q}} = M{sub {tilde g}}. We also present limits on a SU(5) x U(1) supergravity model and a 4 and 1/2 parameter Minimal SUGRA model
A compilation, classification, and comparison of lists of spontaneous speaking vocabulary of children in kindergarten, Grade I, Grade II, and Grade III
Thesis (Ed.M.)--Boston UniversityLanguage development has been studied for many years.
The beginning vocabularies are easy to count ana record.
As tne child grows and moves about, his speaking vocabulary
increases very rapidly. Some estimates suggest
that a minimum speaking vocabulary at six years would include
three thousand words.
New words have come into children's speaking vocabularies
as a result of modern technology since World War II.
Lists of spontaneous vocabulary furnish material for teachers
and text book writers. The purpose of this study is
to analyze two lists recorded in 1954 and 1955.
An attempt has been made to classify the new list.
The lists were compared with three existing lists, Rinsland,
International Kindergarten Union and Gates
Appealing to fear: a meta-analysis of fear appeal effectiveness and theories
The effects of fear appeals on attitudes, intentions, and behaviors were examined in a comprehensive meta-analysis. Studies were included if they contained a treatment group exposed to a fear appeal, a valid comparison group, a manipulation of depicted fear, a measure of attitudes, intentions, or behaviors concerning the targeted risk or recommended solution, and adequate statistics to calculate effect sizes. The meta-analysis included 127 papers (9% unpublished) yielding 248 independent samples (NTotal = 27,372) collected from diverse populations. Results showed a positive effect of fear appeals on attitudes, intentions, and behaviors, with the average effect on a composite index being fixed-effects d ̅ = 0.27. Moderation analyses based on prominent fear appeal theories showed that the effectiveness of fear appeals increased when the message depicted higher levels of fear, included efficacy statements, and depicted high susceptibility and severity. Messages were also more influential when the recommended behavior was one-time only, was self-esteem enhancing (hindering) and death was (was not) mentioned, and occurred at a delay when death was mentioned. Finally, fear appeals were more influential when the message’s audience was primarily female, from collectivist cultures, and young adult
Heavy Ion Physics at RHIC
The status of the physics of heavy ion collisions is reviewed based on
measurements over the past 6 years from the Relativistic Heavy Ion Collider
(RHIC) at Brookhaven National Laboratory. The dense nuclear matter produced in
Au+Au collisions with nucleon-nucleon c.m. energy GeV at
RHIC corresponds roughly to the density and temperature of the universe a few
microseconds after the `big-bang' and has been described as "a perfect liquid"
of quarks and gluons, rather than the gas of free quarks and gluons, ``the
quark-gluon plasma" as originally envisaged. The measurements and arguments
leading to this description will be presented.Comment: 31 pages, 23 figures, Proceedings of Symposium "50+ Years of High
Energy Physics at UB", University at Buffalo, NY, October 20-21,200
Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces
The \emph{Chow parameters} of a Boolean function
are its degree-0 and degree-1 Fourier coefficients. It has been known
since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of
any linear threshold function uniquely specify within the space of all
Boolean functions, but until recently (O'Donnell and Servedio) nothing was
known about efficient algorithms for \emph{reconstructing} (exactly or
approximately) from exact or approximate values of its Chow parameters. We
refer to this reconstruction problem as the \emph{Chow Parameters Problem.}
Our main result is a new algorithm for the Chow Parameters Problem which,
given (sufficiently accurate approximations to) the Chow parameters of any
linear threshold function , runs in time \tilde{O}(n^2)\cdot
(1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a
representation of an LTF that is \eps-close to . The only previous
algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot
2^{2^{\tilde{O}(1/\eps^2)}}.
As a byproduct of our approach, we show that for any linear threshold
function over , there is a linear threshold function which
is \eps-close to and has all weights that are integers at most \sqrt{n}
\cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best
previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot
2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower
bound of (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg,
Servedio). Our techniques also yield improved algorithms for related problems
in learning theory
Deciphering the properties of the medium produced in heavy ion collisions at RHIC by a pQCD analysis of quenched large spectra
We discuss the question of the relevance of perturbative QCD calculations for
analyzing the properties of the dense medium produced in heavy ion collisions.
Up to now leading order perturbative estimates have been worked out and
confronted with data for quenched large hadron spectra. Some of
them are giving paradoxical results, contradicting the perturbative framework
and leading to speculations such as the formation of a strongly interacting
quark-gluon plasma. Trying to bypass some drawbacks of these leading order
analysis and without performing detailed numerical investigations, we collect
evidence in favour of a consistent description of quenching and of the
characteristics of the produced medium within the pQCD framework.Comment: 10 pages, 3 figure
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Multivariate Modeling Identifies Neutrophil- and Th17-Related Factors as Differential Serum Biomarkers of Chronic Murine Colitis
Background: Diagnosis of chronic intestinal inflammation, which characterizes inflammatory bowel disease (IBD), along with prediction of disease state is hindered by the availability of predictive serum biomarker. Serum biomarkers predictive of disease state will improve trials for therapeutic intervention, and disease monitoring, particularly in genetically susceptible individuals. Chronic inflammation during IBD is considered distinct from infectious intestinal inflammation thereby requiring biomarkers to provide differential diagnosis. To address whether differential serum biomarkers could be identified in murine models of colitis, immunological profiles from both chronic spontaneous and acute infectious colitis were compared and predictive serum biomarkers identified via multivariate modeling.Methodology/Principal Findings: Discriminatory multivariate modeling of 23 cytokines plus chlorotyrosine and nitrotyrosine (protein adducts from reactive nitrogen species and hypochlorite) in serum and tissue from two murine models of colitis was performed to identify disease-associated biomarkers. Acute C. rodentium-induced colitis in C57BL/6J mice and chronic spontaneous Helicobacter-dependent colitis in TLR4−/− x IL-10−/− mice were utilized for evaluation. Colon profiles of both colitis models were nearly identical with chemokines, neutrophil- and Th17-related factors highly associated with intestinal disease. In acute colitis, discriminatory disease-associated serum factors were not those identified in the colon. In contrast, the discriminatory predictive serum factors for chronic colitis were neutrophil- and Th17-related factors (KC, IL-12/23p40, IL-17, G-CSF, and chlorotyrosine) that were also elevated in colon tissue. Chronic colitis serum biomarkers were specific to chronic colitis as they were not discriminatory for acute colitis.Conclusions/Significance: Immunological profiling revealed strikingly similar colon profiles, yet distinctly different serum profiles for acute and chronic colitis. Neutrophil- and Th17-related factors were identified as predictive serum biomarkers of chronic colitis, but not acute colitis, despite their presence in colitic tissue of both diseases thereby demonstrating the utility of mathematical modeling for identifying disease-associated serum biomarkers.</p
Multivariate Modeling Identifies Neutrophil- and Th17-Related Factors as Differential Serum Biomarkers of Chronic Murine Colitis
Diagnosis of chronic intestinal inflammation, which characterizes inflammatory bowel disease (IBD), along with prediction of disease state is hindered by the availability of predictive serum biomarker. Serum biomarkers predictive of disease state will improve trials for therapeutic intervention, and disease monitoring, particularly in genetically susceptible individuals. Chronic inflammation during IBD is considered distinct from infectious intestinal inflammation thereby requiring biomarkers to provide differential diagnosis. To address whether differential serum biomarkers could be identified in murine models of colitis, immunological profiles from both chronic spontaneous and acute infectious colitis were compared and predictive serum biomarkers identified via multivariate modeling.Discriminatory multivariate modeling of 23 cytokines plus chlorotyrosine and nitrotyrosine (protein adducts from reactive nitrogen species and hypochlorite) in serum and tissue from two murine models of colitis was performed to identify disease-associated biomarkers. Acute C. rodentium-induced colitis in C57BL/6J mice and chronic spontaneous Helicobacter-dependent colitis in TLR4(-/-) x IL-10(-/-) mice were utilized for evaluation. Colon profiles of both colitis models were nearly identical with chemokines, neutrophil- and Th17-related factors highly associated with intestinal disease. In acute colitis, discriminatory disease-associated serum factors were not those identified in the colon. In contrast, the discriminatory predictive serum factors for chronic colitis were neutrophil- and Th17-related factors (KC, IL-12/23p40, IL-17, G-CSF, and chlorotyrosine) that were also elevated in colon tissue. Chronic colitis serum biomarkers were specific to chronic colitis as they were not discriminatory for acute colitis.Immunological profiling revealed strikingly similar colon profiles, yet distinctly different serum profiles for acute and chronic colitis. Neutrophil- and Th17-related factors were identified as predictive serum biomarkers of chronic colitis, but not acute colitis, despite their presence in colitic tissue of both diseases thereby demonstrating the utility of mathematical modeling for identifying disease-associated serum biomarkers
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