9,120 research outputs found
Lesson Plan For Teaching Flannery O\u27Connor\u27s A Good Man Is Hard To Find
Suitable for high school and college and university classes. Developed by a Swarthmore College student, Adriana Obiols Roca, with feedback from Professor Peter Schmidt, as a final assignment in English 71D, The Short Story in the U.S., spring 2014.
Learning Objectives. Students will: understand the differences between direct and indirect characterization and be able to identify examples of each; understand the uses of irony and foreshadowing in the story as well as more generally in literature; become acquainted with Flannery O’Connor and her writing style, particularly with her use of the grotesque; explore the complexity of the themes present in the story and the characters O’Connor has created, especially the Misfit and the grandmother; exercise a variety of critical thinking and analytical skills in order to form ideas and opinions about O\u27Connor\u27s story and her writing strategies; practice reading comprehension and summarization; employ and practice writing skills in an essay assignment
Identifying Free-Riding in Energy-Conservation Programs Using Revealed Preference Data
Identifying the incidence of free-ridership is significant to a range of issues relevant to program evaluation, including the calculation of net program benefits and more general assessments of political acceptability. Estimates of freeridership in the area of energy policy frequently rely on ex-post surveys that ask program participants whether they would have behaved differently in the absence of program support.The present paper proposes an ex-ante approach to the calculation of the free-rider share using revealed preference data on home renovations from Germany’s residential sector.We employ a discretechoice model to simulate the effect of grants on renovation choices, the output from which is used to assess the extent of free-ridership under a contemporary subsidy program. Aside from its simplicity, a key advantage of the approach is that it bestows policymakers with an estimate of free-ridership prior to program implementation.Energy efficiency, residential sector,random utility model, discrete choice simulation
Primary Care Validation of a Single-Question Alcohol Screening Test
BACKGROUND
Unhealthy alcohol use is prevalent but under-diagnosed in primary care settings.
OBJECTIVE
To validate, in primary care, a single-item screening test for unhealthy alcohol use recommended by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).
DESIGN
Cross-sectional study.
PARTICIPANTS
Adult English-speaking patients recruited from primary care waiting rooms.
MEASUREMENTS
Participants were asked the single screening question, "How many times in the past year have you had X or more drinks in a day?", where X is 5 for men and 4 for women, and a response of >1 is considered positive. Unhealthy alcohol use was defined as the presence of an alcohol use disorder, as determined by a standardized diagnostic interview, or risky consumption, as determined using a validated 30-day calendar method.
MAIN RESULTS
Of 394 eligible primary care patients, 286 (73%) completed the
interview. The single-question screen was 81.8% sensitive (95% confidence interval (CI) 72.5% to 88.5%) and 79.3% specific (95% CI 73.1% to 84.4%) for the detection of unhealthy alcohol use. It was slightly more sensitive (87.9%, 95% CI 72.7% to 95.2%) but was less specific (66.8%, 95% CI 60.8% to 72.3%) for the detection of a current alcohol use disorder. Test characteristics were similar to that of a commonly used three-item screen, and were affected very little by subject demographic characteristics.
CONCLUSIONS. The single screening question recommended by the NIAAA accurately identified unhealthy alcohol use in this sample of primary care patients. These findings support the use of this brief screen in primary care.National Institute on Alcohol Abuse and Alcoholism (R01-AA010870
Flavour symmetry breaking in the kaon parton distribution amplitude
We compute the kaon's valence-quark (twist-two parton) distribution amplitude
(PDA) by projecting its Poincare'-covariant Bethe-Salpeter wave-function onto
the light-front. At a scale \zeta=2GeV, the PDA is a broad, concave and
asymmetric function, whose peak is shifted 12-16% away from its position in
QCD's conformal limit. These features are a clear expression of
SU(3)-flavour-symmetry breaking. They show that the heavier quark in the kaon
carries more of the bound-state's momentum than the lighter quark and also that
emergent phenomena in QCD modulate the magnitude of flavour-symmetry breaking:
it is markedly smaller than one might expect based on the difference between
light-quark current masses. Our results add to a body of evidence which
indicates that at any energy scale accessible with existing or foreseeable
facilities, a reliable guide to the interpretation of experiment requires the
use of such nonperturbatively broadened PDAs in leading-order, leading-twist
formulae for hard exclusive processes instead of the asymptotic PDA associated
with QCD's conformal limit. We illustrate this via the ratio of kaon and pion
electromagnetic form factors: using our nonperturbative PDAs in the appropriate
formulae, at spacelike-, which compares
satisfactorily with the value of inferred in annihilation
at .Comment: 7 pages, 2 figures, 3 table
A Designation Guide for Consistent Cross-System-Level Modeling of Embodiment Function Relations
BVRI Light Curves for 22 Type Ia Supernovae
We present 1210 Johnson/Cousins B,V,R, and I photometric observations of 22
recent type Ia supernovae (SNe Ia): SN 1993ac, SN 1993ae, SN 1994M, SN 1994S,
SN 1994T, SN 1994Q, SN 1994ae, SN 1995D, SN 1995E, SN 1995al, SN 1995ac, SN
1995ak, SN 1995bd, SN 1996C, SN 1996X, SN 1996Z, SN 1996ab, SN 1996ai, SN
1996bk, SN 1996bl, SN 1996bo, and SN 1996bv. Most of the photometry was
obtained at the Fred Lawrence Whipple Observatory (FLWO) of the
Harvard-Smithsonian Center for Astrophysics in a cooperative observing plan
aimed at improving the data base for SN Ia. The redshifts of the sample range
from =1200 to 37000 km s with a mean of =7000 km s.Comment: Accepted to the Astronomical Journal, 41 pages, 8 figure
Real Time Enzyme Inhibition Assays Provide Insights into Differences in Binding of Neuraminidase Inhibitors to Wild Type and Mutant Influenza Viruses
The influenza neuraminidase (NA) inhibitors zanamivir, oseltamivir and peramivir were all designed based on the knowledge that the transition state analogue of the cleaved sialic acid, 2-deoxy,2,3-dehydro N-acetyl neuraminic acid (DANA) was a weak inhibitor of NA. While DANA bound rapidly to the NA, modifications leading to the improved potency of these new inhibitors also conferred a time dependent or slow binding phenotype. Many mutations in the NA leading to decreased susceptibility result in loss of slow binding, hence this is a phenotypic marker of many but not all resistant NAs. We present here a simplified approach to determine whether an inhibitor is fast or slow binding by extending the endpoint fluorescent enzyme inhibition assay to a real time assay and monitoring the changes in IC50s with time. We carried out two reactions, one with a 30 min preincubation with inhibitor and the second without. The enzymatic reaction was started via addition of substrate and IC50s were calculated after each 10 min interval up to 60 min. Results showed that without preincubation IC50s for the wild type viruses started high and although they decreased continuously over the 60 min reaction time the final IC50s remained higher than for pre-incubated samples. These results indicate a slow equilibrium of association and dissociation and are consistent with slow binding of the inhibitors. In contrast, for viruses with decreased susceptibility, preincubation had minimal effect on the IC50s, consistent with fast binding. Therefore this modified assay provides additional phenotypic information about the rate of inhibitor binding in addition to the IC50, and critically demonstrates the differential effect of incubation times on the IC50 and Ki values of wild type and mutant viruses for each of the inhibitors
Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides
The tyrosine-(M)210 of the reaction center of Rhodobacter sphaeroides 2.4.1 has been changed to a tryptophan using site-directed mutagenesis. The reaction center of this mutant has been characterized by low-temperature absorption and fluorescence spectroscopy, time-resolved sub-picosecond spectroscopy, and magnetic resonance spectroscopy. The charge separation process showed bi-exponential kinetics at room temperature, with a main time constant of 36 ps and an additional fast time constant of 5.1 ps. Temperature dependent fluorescence measurements predict that the lifetime of P* becomes 4–5 times slower at cryogenic temperatures. From EPR and absorbance-detected magnetic resonance (ADMR, LD-ADMR) we conclude that the dimeric structure of P is not significantly changed upon mutation. In contrast, the interaction of the accessory bacteriochlorophyll BA with its environment appears to be altered, possibly because of a change in its position
The abstract boundary---a new approach to singularities of manifolds
A new scheme is proposed for dealing with the problem of singularities in
General Relativity. The proposal is, however, much more general than this. It
can be used to deal with manifolds of any dimension which are endowed with
nothing more than an affine connection, and requires a family \calc\ of curves
satisfying a {\em bounded parameter property} to be specified at the outset.
All affinely parametrised geodesics are usually included in this family, but
different choices of family \calc\ will in general lead to different
singularity structures. Our key notion is the {\em abstract boundary\/} or {\em
-boundary\/} of a manifold, which is defined for any manifold \calm\ and is
independent of both the affine connection and the chosen family \calc\ of
curves. The -boundary is made up of equivalence classes of boundary points
of \calm\ in all possible open embeddings. It is shown that for a
pseudo-Riemannian manifold (\calm,g) with a specified family \calc\ of
curves, the abstract boundary points can then be split up into four main
categories---regular, points at infinity, unapproachable points and
singularities. Precise definitions are also provided for the notions of a {\em
removable singularity} and a {\em directional singularity}. The
pseudo-Riemannian manifold will be said to be singularity-free if its abstract
boundary contains no singularities. The scheme passes a number of tests
required of any theory of singularities. For instance, it is shown that all
compact manifolds are singularity-free, irrespective of the metric and chosen
family \calc.Comment: 40 pages (amslatex) + 5 uuencoded figures (A postscript version is
also available on http://einstein.anu.edu.au/), CMA Maths. Research Report
No. MRR028-9
Final-State Interactions in e^+e^- -> t\bar{t} -> b l^+ \nu \bar{b} W^- Near Top Quark Threshold
We calculate final-state interaction corrections to the energy-angular
distribution of l^+ in semi-leptonic top quark decay, where the parent top
quark is produced via e^+e^- -> t\bar{t} near threshold. These are the
corrections due to gluon exchange between t and \bar{b} (\bar{t} and b) and
between b and \bar{b}. Combining with previously known other corrections, we
explicitly write down the l^+ energy-angular distribution including the full
O(alpha_s)=O(beta) corrections near t\bar{t} threshold. Numerical analyses of
the final-state interaction corrections are given. We find that they deform the
l^+ distribution typically at the 10% level. We also find that all qualitative
features of the numerical results can be understood from intuitive pictures.
The mechanisms of various effects of the final-state interactions are
elucidated. Finally we define an observable which is proper to the decay
process of the top quark (dependent only on d\Gamma_{t -> b l^+ \nu}/ dE_l
d\Omega_l of a free polarized top quark) near t\bar{t} threshold. Such a
quantity will be useful in extracting the decay property of the top quark using
the highly polarized top quark samples.Comment: Section 6 is enlarged substantially and a paragraph is added to
Section 8 correspondingly. Reference list is also improved. (27 pages
including figures, LaTeX
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