12,698 research outputs found
Restrictive Immigration Policies and Latino Immigrant Identity in the United States
The United States is presently characterized by rising anti-immigrant sentiment, repressive immigration enforcement, and the negative framing of Latinos as threatening and undesirable. As a result, social boundaries between immigrants and natives have hardened and boundary crossing has become more difficult. Under these circumstances, the prediction of classical assimilation theory is turned on its head: the more time that immigrants spend in the United States and the more contact they have with Americans and American society, the more aware they become of the harsh realities of prejudice and discrimination and the more they come to experience the rampant inequalities of the secondary labor market. Rather than ideologically assimilating, therefore, the greater their experience in the United States, the more likely immigrants are to express a reactive ethnicity that rejects the label “American.” Our work suggests that the greatest threat to the successful assimilation of immigrants comes not from foreign involvements or transnational loyalties, but from the rejection, exclusion, and discrimination that immigrants experience in the United States.Immigration, Exclusion, Discrimination, Latinos, Identity
Restrictive Immigration Policies and Latino Immigrant Identity in the United States
The United States is presently characterized by rising anti-immigrant sentiment, repressive immigration enforcement, and the negative framing of Latinos as threatening and undesirable. As a result, social boundaries between immigrants and natives have hardened and boundary crossing has become more difficult. Under these circumstances, the prediction of classical assimilation theory is turned on its head: the more time that immigrants spend in the United States and the more contact they have with Americans and American society, the more aware they become of the harsh realities of prejudice and discrimination and the more they come to experience the rampant inequalities of the secondary labor market. Rather than ideologically assimilating, therefore, the greater their experience in the United States, the more likely immigrants are to express a reactive ethnicity that rejects the label “American.” Our work suggests that the greatest threat to the successful assimilation of immigrants comes not from foreign involvements or transnational loyalties, but from the rejection, exclusion, and discrimination that immigrants experience in the United States.Immigration, Exclusion, Discrimination, Latinos, Identity
Red Supergiants in the Andromeda Galaxy (M31)
Red supergiants are a short-lived stage in the evolution of moderately
massive stars (10-25Mo), and as such their location in the H-R diagram provides
an exacting test of stellar evolutionary models. Since massive star evolution
is strongly affected by the amount of mass-loss a star suffers, and since the
mass-loss rates depend upon metallicity, it is highly desirable to study the
physical properties of these stars in galaxies of various metallicities. Here
we identify a sample of red supergiants in M31 (the most metal-rich of the
Local Group galaxies) and derive their physical properties by fitting MARCS
atmosphere models to moderate resolution optical spectroscopy, and from V-K
photometry.Comment: Accepted for publication in the Astrophysical Journa
A Pilot Program to Assist CAFOs in Using Weather Data to Minimize Manure Management Risk
This paper summarizes a pilot project to disseminate site specific weather information that has been processed to estimate field runoff potential of land applied manure. Preliminary feedback indicate the program has value but that additional information is needed to understand how farmers use weather information to make decisions within the regulatory constraints they face.Environmental Economics and Policy,
"State Dependence and Long Term Site Capital in a Random Utility Model of Recreation Demand"
Conventional discrete choice Random Utility Maximization (RUM) models of recreation demand ignore the influence of knowledge, or site capital, gained over past trips on current site choice, despite its obvious impact. We develop a partially dynamic RUM model that incorporates a measure of site capital as an explanatory variable in an effort to address this shortcoming. To avoid the endogeneity of past and current trip choices, we estimate an auxiliary instrumental variable regression to purge site capital of its correlation with the error terms in current site utility. Our instrumental variable regression gives a fitted value ranging between 0 and 1 for each alternative for each person – a prediction of whether or not a person visited a site. Results suggest that the presence of accumulated site capital is an important predictor of current trips, and that failure to account for site capital will likely lead to underestimates of potential welfare effects.Random Utility Model; State Dependence; Non-Market Valuation
Deconvolution with Shapelets
We seek to find a shapelet-based scheme for deconvolving galaxy images from
the PSF which leads to unbiased shear measurements. Based on the analytic
formulation of convolution in shapelet space, we construct a procedure to
recover the unconvolved shapelet coefficients under the assumption that the PSF
is perfectly known. Using specific simulations, we test this approach and
compare it to other published approaches. We show that convolution in shapelet
space leads to a shapelet model of order
with and being the maximum orders of the intrinsic
galaxy and the PSF models, respectively. Deconvolution is hence a
transformation which maps a certain number of convolved coefficients onto a
generally smaller number of deconvolved coefficients. By inferring the latter
number from data, we construct the maximum-likelihood solution for this
transformation and obtain unbiased shear estimates with a remarkable amount of
noise reduction compared to established approaches. This finding is
particularly valid for complicated PSF models and low images, which
renders our approach suitable for typical weak-lensing conditions.Comment: 9 pages, 9 figures, submitted to A&
The Yellow and Red Supergiants of M33
Yellow and red supergiants are evolved massive stars whose numbers and
locations on the HR diagram can provide a stringent test for models of massive
star evolution. Previous studies have found large discrepancies between the
relative number of yellow supergiants observed as a function of mass and those
predicted by evolutionary models, while a disagreement between the predicted
and observed locations of red supergiants on the HR diagram was only recently
resolved. Here we extend these studies by examining the yellow and red
supergiant populations of M33. Unfortunately, identifying these stars is
difficult as this portion of the color-magnitude diagram is heavily
contaminated by foreground dwarfs. We identify the red supergiants through a
combination of radial velocities and a two-color surface gravity discriminant
and, after re-characterizing the rotation curve of M33 with our newly selected
red supergiants, we identify the yellow supergiants through a combination of
radial velocities and the strength of the OI 7774 triplet. We examine
~1300 spectra in total and identify 121 yellow supergiants (a sample which is
unbiased in luminosity above log(L/L\odot) ~ 4.8) and 189 red supergiants.
After placing these objects on the HR diagram, we find that the latest
generation of Geneva evolutionary tracks show excellent agreement with the
observed locations of our red and yellow supergiants, the observed relative
number of yellow supergiants with mass and the observed red supergiant upper
mass limit. These models therefore represent a drastic improvement over
previous generations.Comment: Accepted for publication in the Astrophysical Journa
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