1,760 research outputs found
Making the Most of Conferring in Reading Workshop
Reading conferences with students are an integral part of the reader’s workshop format. Conferring provides the opportunity for students to reveal their thinking and reading processes to the teacher. This workshop will explore ways to target the needs of your students and gain deeper insight into their strengths and learning needs
Conferring Made Easier Using Writing Toolkits
Many teachers struggle with making their conferences effective and meaningful. What do you do when faced with that immediate challege of what to focus on in a writing piece that has many areas that need support? Discover the different types of conferences and the tools that will help make your conferences memorable, supportive and efficient
Launching and Supporting Writing Workshop
This teacher friendly workshop will provide participants with a fast-paced overview of some of the most practical and effective strategies for supporting students to write clear, coherent pieces of writing across genres. Throughout the workshop, participants will learn specific strategies for supporting a wide range of students. This workshop will touch up ways to help students brainstorm ideas and plan sections of their work. This workshop will help support the new ELA Standards of Learnin
The equivalence of fluctuation scale dependence and autocorrelations
We define optimal per-particle fluctuation and correlation measures, relate
fluctuations and correlations through an integral equation and show how to
invert that equation to obtain precise autocorrelations from fluctuation scale
dependence. We test the precision of the inversion with Monte Carlo data and
compare autocorrelations to conditional distributions conventionally used to
study high- jet structure.Comment: 10 pages, 9 figures, proceedings, MIT workshop on correlations and
fluctuations in relativistic nuclear collision
Developing collaborative partnerships with culturally and linguistically diverse families during the IEP process
Family participation in the special education process has been federally mandated for 40 years, and educators recognize that effective collaboration with their students’ families leads to improved academic and social outcomes for students. However, while some family-school relationships are positive and collaborative, many are not, particularly for culturally and linguistically diverse (CLD) families. This article provides practice guidelines based in research for teachers who seek to improve their practices when working with CLD families who have children served by special education
A High Fraction of Ly-alpha-Emitters Among Galaxies with Extreme Emission Line Ratios at z ~ 2
Star-forming galaxies form a sequence in the [OIII]/H-beta vs. [NII]/H-alpha
diagnostic diagram, with low metallicity, highly ionized galaxies falling in
the upper left corner. Drawing from a large sample of UV-selected star-forming
galaxies at z~2 with rest-frame optical nebular emission line measurements from
Keck-MOSFIRE, we select the extreme ~5% of the galaxies lying in this upper
left corner, requiring log([NII]/H-alpha) =
0.75. These cuts identify galaxies with 12 + log(O/H) <~ 8.0, when oxygen
abundances are measured via the O3N2 diagnostic. We study the Ly-alpha
properties of the resulting sample of 14 galaxies. The mean (median) rest-frame
Ly-alpha equivalent width is 39 (36) A, and 11 of the 14 objects (79%) are
Ly-alpha-emitters (LAEs) with W_Lya > 20 A. We compare the equivalent width
distribution of a sample of 522 UV-selected galaxies at 2.0<z<2.6 identified
without regard to their optical line ratios; this sample has mean (median)
Ly-alpha equivalent width -1 (-4) A, and only 9% of these galaxies qualify as
LAEs. The extreme galaxies typically have lower attenuation at Ly-alpha than
those in the comparison sample, and have ~50% lower median oxygen abundances.
Both factors are likely to facilitate the escape of Ly-alpha: in less dusty
galaxies Ly-alpha photons are less likely to be absorbed during multiple
scatterings, while the harder ionizing spectrum and higher ionization parameter
associated with strong, low metallicity star formation may reduce the covering
fraction or column density of neutral hydrogen, further easing Ly-alpha escape.
The use of nebular emission line ratios may prove useful in the identification
of galaxies with low opacity to Ly-alpha photons across a range of redshifts.Comment: 12 pages, 5 figures, 2 tables. Accepted for publication in Ap
The static and dynamic conductivity of warm dense Aluminum and Gold calculated within a density functional approach
The static resistivity of dense Al and Au plsmas are calculated where all the
needed inputs are obtained from density functional theory (DFT). This is used
as input for a study of the dynamic conductivity. These calculations involve a
self-consistent determination of (i) the equation of state (EOS) and the
ionization balance, (ii) evaluation of the ion-ion, and ion-electron
pair-distribution functions, (iii) Determination of the scattering amplitudes,
and finally the conductivity. We present data for the static resistivity of Al
for compressions 0.1-2.0, and in the temperature range T= 0.1 - 10 eV. Results
for Au in the same temperature range and for compressions 0.1-1.0 is also
given. In determining the dynamic conductivity for a range of frequencies
consistent with standard laser probes, a knowledge of the electronic
eigenstates and occupancies of Al- or Au plasma becomes necessary. They are
calculated using a neutral-pseudoatom model. We examine a number of
first-principles approaches to the optical conductivity, including many-body
perturbation theory, molecular-dynamics evaluations, and simplified
time-dependent DFT. The modification to the Drude conductivity that arises from
the presence of shallow bound states in typical Al-plasmas is examined and
numerical results are given at the level of the Fermi Golden rule and an
approximate form of time-dependent DFT.Comment: 5 figures, Latex original. Cross-referencced to PLASMA PHYSIC
Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE
We present initial results of a deep near-IR spectroscopic survey covering
the 15 fields of the Keck Baryonic Structure Survey (KBSS) using MOSFIRE on the
Keck 1 telescope, focusing on a sample of 251 galaxies with redshifts 2.0< z <
2.6, star-formation rates 2 < SFR < 200 M_sun/yr, and stellar masses 8.6 <
log(M*/M_sun) < 11.4, with high-quality spectra in both H- and K-band
atmospheric windows. We show unambiguously that the locus of z~2.3 galaxies in
the "BPT" nebular diagnostic diagram exhibits a disjoint, yet similarly tight,
relationship between the ratios [NII]6585/Halpha and [OIII]/Hbeta as compared
to local galaxies. Using photoionization models, we argue that the offset of
the z~2.3 locus relative to z~ 0 is explained by a combination of harder
ionizing radiation field, higher ionization parameter, and higher N/O at a
given O/H than applies to most local galaxies, and that the position of a
galaxy along the z~2.3 star-forming BPT locus is surprisingly insensitive to
gas-phase oxygen abundance. The observed nebular emission line ratios are most
easily reproduced by models in which the net ionizing radiation field resembles
a blackbody with effective temperature T_eff = 50000-60000 K and N/O close to
the solar value at all O/H. We critically assess the applicability of
commonly-used strong line indices for estimating gas-phase metallicities, and
consider the implications of the small intrinsic scatter in the empirical
relationship between excitation-sensitive line indices and stellar mass (i.e.,
the "mass-metallicity" relation), at z~2.3.Comment: 41 pages, 25 figures, accepted for publication in the Astrophysical
Journal. Version with full-resolution figures available at
http://www.astro.caltech.edu/~ccs/mos_bpt_submit.pd
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