587 research outputs found
B_c and Excited B States - A Tevatron Review
In this paper recent results from the CDF and D0 experiments on heavy flavor
spectroscopy are reported. Both experiments are using up to 1.1 fb^{-1} of data
delivered by the Tevatron proton-antiproton collider at the Fermi National
Accelerator Laboratory, Batavia IL, USA.Comment: To appear in the conference proceedings for Beauty 200
Heavy hadron spectroscopy and the bag model
Some time ago a slightly improved variant of bag model (the modified bag
model) suitable for the unified description of light and heavy hadrons was
developed. The main goal of the present work was to calculate the masses of the
ground state baryons containing bottom quarks in the framework of this model.
For completeness the predictions for other heavy hadrons are also given. The
reasonable agreement of our results with other theoretical calculations and
available experimental data suggests that our predictions could serve as a
useful complementary tool for the interpretation of heavy hadron spectra.Comment: 18 pages, 9 tables, references to experiments updated, rms deviations
given in some table
Morning concurrent track 1: What does it mean for K-12 students to think about sustainability in the Western U.S.?
MORNING CONCURRENT TRACK 1: WHAT DOES IT MEAN FOR K-12 STUDENTS TO THINK ABOUT SUSTAINABILITY IN THE WESTERN U.S.? Moderator Kent Crippen Student Union Room 207 Ellen Ebert - Using the STS/EEE Model in 6-12 Curriculum to Understand the Sustainability Issues Related to the Colorado River System (repeats Afternoon Concurrent Session #1) Abstract: Beginning in 1982, the National Science Teachers Association called for curriculum designers to develop materials that demonstrate the interconnectedness among science, technology and societal issues while presenting both positive and negative influences. This session will focus on using the STS/EEE learning model to design curriculum for secondary science that emphasizes sustainability issues focused on the Colorado River system. The presentation will outline the essential features of the STS/EEE model, then engage participants in applying the model in a novel situation. Rebecca Reichenbach – CCSD Action Research: Understanding the Urban Heat Island Effect (repeats Afternoon Concurrent Session #1) Abstract: Due to the unique placement of Western High School within a concrete and asphalt island and a result construction project to rebuild it, a group of science teachers from Western High became interested in how the new construction would affect the urban heat island footprint of their school. A student project was developed to track and document the construction process over a two-year timeframe. The participating teachers used action research to study the impact of the project on their teaching practice and student learning. Three inquiry-style laboratory activities were created to teach students about heat concepts and the effect of heat islands. A misconceptions survey, along with student journaling, were used as data sources for determining changes in student understanding. Results show significant conceptual change in the grade 9 students, with less significant change for the older student population. This presentation will describe the research context, process, and its impact on participating students and teachers. Allison Brody, Amy Page – Environmental Literacy as an Indicator for Urban Sustainability Abstract: For sustainability initiatives to be successful, citizens must have the knowledge, action skills, and motivation to support and participate in these initiatives. In other words, Urban Sustainability will not be successful unless our citizens are environmentally literate. The responsibility for creating this “environmentally literate” citizenry should fall in large part to educators, both in the formal and non-formal sectors. Therefore, these educators need a clear understanding of the specific knowledge and action skills that our citizens need. In this session, we will explore the competencies that citizens need to engage in sustainability practices in Nevada, and how educators can incorporate these competencies into their curricula and programs. Marcel Parent, Signa Gundlach – Sustainability Education at the Springs Preserve: Broad Strokes and Targeting Standards Abstract: Sustainability is a rather unwieldy and challenging area in education. From the broad but vague concepts defining it, to the innumerable sectors of human activities in which it applies, learning about sustainability is at the same time wonderfully simple and terrible complex. This presentation will introduce the participants to some of the approaches taken at the Springs Preserve to make learning about sustainability an engaging experience that will impact future behavior
The New Heavy Mesons: A Status Report
A survey of the experimental, phenomenological, and theoretical status of the
new heavy mesons is presented. States discussed are the , ,
, , , X(3872), X(3940), Y(3940), Z(3930), and
Y(4260). Quark models for spectra, strong decays, and hadronic interactions are
reviewed and used to interpret the new states. New results for strong decay
models, bound state decays, mesonic molecules, properties of the X(3872), and
the chiral doublet model are also presented.Comment: 62 page, 40 figs, 16 tables. v3 corrects typos, adds references.
Version to appear in Physics Report
Ab initio calculations of the physical properties of transition metal carbides and nitrides and possible routes to high-Tc
Ab initio linear-response calculations are reported of the phonon spectra and
the electron-phonon interaction for several transition metal carbides and
nitrides in a NaCl-type structure. For NbC, the kinetic, optical, and
superconducting properties are calculated in detail at various pressures and
the normal-pressure results are found to well agree with the experiment.
Factors accounting for the relatively low critical temperatures Tc in
transition metal compounds with light elements are considered and the possible
ways of increasing Tc are discussed.Comment: 19 pages, 7 figure
Measuring the Autistic Women's Experience (AWE)
We developed a Dutch questionnaire called the Autistic Women's Experience (AWE) and compared its psychometric properties to the Autism Spectrum Quotient (AQ). Whilst attenuated gender differences on the AQ have been widely replicated, this instrument may not fully capture the unique experience of autistic women. The AWE was co-developed with autistic women to include items that reflect autistic women's experience. We investigated the AWE (49 items) and compared it with the AQ (50 items) in Dutch autistic individuals ( N = 153, n = 85 women) and in the general population ( N = 489, n = 246 women) aged 16+. Both the AQ and AWE had excellent internal consistency and were highly and equally predictive of autism in both women and men. Whilst there was a gender difference on the AQ among non-autistic people (men > women), there was no gender difference among autistic people, confirming all earlier studies. No gender differences were detected on the AWE overall scale, yet subtle gender differences were observed on the subscales. We conclude that the AQ is valid for both genders, but the AWE provides an additional useful perspective on the characteristics of autistic women. The AWE needs further validation in independent samples using techniques that allow for testing gender biases, as well as a confirmatory factor analysis in a larger sample. </p
Study of Bc --> J/psi pi, etac pi decays with perturbative QCD approach
The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD
approach. It is found that form factors and branching ratios are sensitive to
the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of
the charmonium wave functions for Coulomb potential and harmonic oscillator
potential, respectively, f_J/psi and f_etac are the decay constants of the
J/psi and etac mesons, respectively. The large branching ratios and the clear
signals of the final states make the Bc --> J/psi pi, etac pi decays to be the
prospective channels for measurements at the hadron collidersComment: 21 pages, revtex
Self-oligomerization Regulates Stability of Survival Motor Neuron Protein Isoforms by Sequestering an SCF\u3csup\u3eSlmb\u3c/sup\u3e Degron
Spinal muscular atrophy (SMA) is caused by homozygous mutations in human SMN1. Expression of a duplicate gene (SMN2) primarily results in skipping of exon 7 and production of an unstable protein isoform, SMNΔ7. Although SMN2 exon skipping is the principal contributor to SMA severity, mechanisms governing stability of survival motor neuron (SMN) isoforms are poorly understood. We used a Drosophila model system and label-free proteomics to identify the SCFSlmb ubiquitin E3 ligase complex as a novel SMN binding partner. SCFSlmb interacts with a phosphor degron embedded within the human and fruitfly SMN YG-box oligomerization domains. Substitution of a conserved serine (S270A) interferes with SCFSlmb binding and stabilizes SMNΔ7. SMA-causing missense mutations that block multimerization of full-length SMN are also stabilized in the degron mutant background. Overexpression of SMNΔ7S270A, but not wild-type (WT) SMNΔ7, provides a protective effect in SMA model mice and human motor neuron cell culture systems. Our findings support a model wherein the degron is exposed when SMN is monomeric and sequestered when SMN forms higher-order multimers
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