645 research outputs found
Catching the "Local" Bug: A Look at State Agricultural Marketing Programs
State Marketing Program, Local Foods, Consumer Awareness, State-Sponsored Logos, Mid-Atlantic Region, Marketing,
Comparing Willingness to Pay for Organic, Natural, Locally Grown, and State Marketing Program Promoted Foods in the Mid-Atlantic Region
A choice experiment of Mid-Atlantic consumers was conducted to determine marginal willingness to pay for the attributes organic, natural, locally grown, and state marketing program promoted for strawberry preserves. The influence of purchasing venue on willingness to pay was also examined. Results indicated a price premium when purchased at a farmers market across all five states and versions. Organic was preferred to natural in only one state. Preference ordering between local and state program promoted varied. Consumers in Maryland and Pennsylvania clearly preferred local, while those in New Jersey seemed most likely to prefer the state program version.organic, natural, locally grown, state marketing program, choice experiment, Consumer/Household Economics, Demand and Price Analysis, Marketing,
Metformin Induces a Dietary Restriction–Like State and the Oxidative Stress Response to Extend C. elegans Healthspan via AMPK, LKB1, and SKN-1
Metformin, a biguanide drug commonly used to treat type-2 diabetes, has been noted to extend healthspan of nondiabetic mice, but this outcome, and the molecular mechanisms that underlie it, have received relatively little experimental attention. To develop a genetic model for study of biguanide effects on healthspan, we investigated metformin impact on aging Caenorhabditis elegans. We found that metformin increases nematode healthspan, slowing lipofuscin accumulation, extending median lifespan, and prolonging youthful locomotory ability in a dose-dependent manner. Genetic data suggest that metformin acts through a mechanism similar to that operative in eating-impaired dietary restriction (DR) mutants, but independent of the insulin signaling pathway. Energy sensor AMPK and AMPK-activating kinase LKB1, which are activated in mammals by metformin treatment, are essential for health benefits in C. elegans, suggesting that metformin engages a metabolic loop conserved across phyla. We also show that the conserved oxidative stress-responsive transcription factor SKN-1/Nrf2 is essential for metformin healthspan benefits in C. elegans, a mechanistic requirement not previously described in mammals. skn-1, which functions in nematode sensory neurons to promote DR longevity benefits and in intestines for oxidative stress resistance lifespan benefits, must be expressed in both neurons and intestines for metformin-promoted healthspan extension, supporting that metformin improves healthy middle-life aging by activating both DR and antioxidant defense longevity pathways. In addition to defining molecular players operative in metformin healthspan benefits, our data suggest that metformin may be a plausible pharmacological intervention to promote healthy human aging
Reverberation Mapping Results from MDM Observatory
We present results from a multi-month reverberation mapping campaign
undertaken primarily at MDM Observatory with supporting observations from
around the world. We measure broad line region (BLR) radii and black hole
masses for six objects. A velocity-resolved analysis of the H_beta response
shows the presence of diverse kinematic signatures in the BLR.Comment: To appear in the Proceedings of the IAU Symposium No. 267:
Co-Evolution of Central Black Holes and Galaxies, Rio de Janeiro, 200
Reverberation Mapping of IC4329A
We present the results of a new reverberation mapping campaign for the
broad-lined active galactic nucleus (AGN) in the edge-on spiral IC4329A.
Monitoring of the optical continuum with band photometry and broad
emission-line flux variability with moderate-resolution spectroscopy allowed
emission-line light curves to be measured for H, H, and HeII
. We find a time delay of days for H,
a similar time delay of days for H, and an
unresolved time delay of days for HeII. The time delay for
H is consistent with the predicted value from the relationship between
AGN luminosity and broad line region radius, after correction for the
mag of intrinsic extinction at 5100A. Combining the measured time
delay for H with the broad emission line width and an adopted value of
, we find a central supermassive black hole mass of
. Velocity-resolved time
delays were measured across the broad H emission-line profile and may be
consistent with an ''M''-like shape. Modeling of the full reverberation
response of H was able to provide only modest constraints on some
parameters, but does exhibit agreement with the black hole mass and average
time delay. The models also suggest that the AGN structure is misaligned by a
large amount from the edge-on galaxy disk. This is consistent with expectations
from the unified model of AGNs, in which broad emission lines are expected to
be visible only for AGNs that are viewed at relatively face-on inclinations.Comment: 12 pages, 6 figures, 3 tables; accepted for publication in Ap
Metastatic model of HPV+ oropharyngeal squamous cell carcinoma demonstrates heterogeneity in tumor metastasis
Human papillomavirus induced (HPV+) cancer incidence is rapidly rising, comprising 60–80% of oropharyngeal squamous cell carcinomas (OPSCCs); while rare, recurrent/metastatic disease accounts for nearly all related deaths. An in vivo pre-clinical model for these invasive cancers is necessary for testing new therapies. We characterize an immune competent recurrent/metastatic HPV+ murine model of OPSSC which consists of four lung metastatic (MLM) cell lines isolated from an animal with HPV+ OPSCC that failed cisplatin/radiation treatment. These individual metastatic clonal cell lines were tested to verify their origin (parental transgene expression and define their physiological properties: proliferation, metastatic potential, heterogeneity and sensitivity/resistance to cisplatin and radiation. All MLMs retain expression of parental HPV16 E6 and E7 and degrade P53 yet are heterogeneous from one another and from the parental cell line as defined by Illumina expression microarray. Consistent with this, reverse phase protein array defines differences in protein expression/activation between MLMs as well as the parental line. While in vitro growth rates of MLMs are slower than the parental line, in vivo growth of MLM clones is greatly enhanced. Moreover, in vivo resistance to standard therapies is dramatically increased in 3 of the 4 MLMs. Lymphatic and/or lung metastasis occurs 100% of the time in one MLM line. This recurrent/metastatic model of HPV+ OPSCC retains the characteristics evident in refractory human disease (heterogeneity, resistance to therapy, metastasis in lymph nodes/lungs) thus serving as an ideal translational system to test novel therapeutics. Moreover, this system may provide insights into the molecular mechanisms of metastasis
Systematic Uncertainties in Black Hole Masses Determined from Single Epoch Spectra
We explore the nature of systematic errors that can arise in measurement of
black hole masses from single-epoch spectra of active galactic nuclei (AGNs) by
utilizing the many epochs available for NGC 5548 and PG1229+204 from
reverberation mapping databases. In particular, we examine systematics due to
AGN variability, contamination due to constant spectral components (i.e.,
narrow lines and host galaxy flux), data quality (i.e., signal-to-noise ratio,
S/N), and blending of spectral features by comparing the precision and accuracy
of single-epoch mass measurements to those of recent reverberation mapping
studies. We calculate masses by characterizing the broad Hbeta emission line by
both the full width at half maximum and the line dispersion and demonstrate the
importance of removing narrow emission-line components and host starlight. We
find that the reliability of line width measurements rapidly decreases for S/N
lower than ~10 to 20 (per pixel) and that fitting the line profiles instead of
direct measurement of the data does not mitigate this problem but can, in fact,
introduce systematic errors. We also conclude that a full spectral
decomposition to deblend the AGN and galaxy spectral features is unnecessary
except to judge the contribution of the host galaxy to the luminosity and to
deblend any emission lines that may inhibit accurate line width measurements.
Finally, we present an error budget which summarizes the minimum observable
uncertainties as well as the amount of additional scatter and/or systematic
offset that can be expected from the individual sources of error investigated.
In particular, we find that the minimum observable uncertainty in single-epoch
mass estimates due to variability is ~ 20 per pixel)
spectra.Comment: 60 pages, 20 figures, accepted for publication in Ap
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