736 research outputs found
Resident Impacts of Immigration: Perspectives from America’s Age of Mass Migration
Elementary economic models are often used to suggest that immigration depresses the wages of native-born workers. These models assume that when immigrants enter a labour market, all other features of that market remain unchanged. Such an assumption is almost never valid. Here we explore the economic impacts of immigrants during America’s Age of Mass Migration a century ago. This was a period of dynamic structural change that witnessed the appearance of new industries, adoption of new technologies, discovery of new mineral resources, the rise of big business, and the geographic concentration of industries. We show that immigrants – and residents – selected destinations where labour demand and wages were rising. Thus, native workers experienced wage increases in the presence of heavy immigration. Models that abstract from the special characteristics of labour markets that attract immigrants misrepresent their economic impact.Immigration, Internal migration, Economic history of immigration, Counterfactual analysis
Dark and Baryonic Matter in Bright Spiral Galaxies: I.Near-infrared and Optical Broadband Surface Photometry of 30 Galaxies
We present photometrically calibrated images and surface photometry in the B,
V, R, J, H, and K-bands of 25, and in the g, r, and K-bands of 5 nearby bright
(Bo_T<12.5 mag) spiral galaxies with inclinations between 30-65 degrees
spanning the Hubble Sequence from Sa to Scd. Data are from The Ohio State
University Bright Spiral Galaxy Survey, the Two Micron All Sky Survey, and the
Sloan Digital Sky Survey Second Data Release. Radial surface brightness
profiles are extracted, and integrated magnitudes are measured from the
profiles. Axis ratios, position angles, and scale lengths are measured from the
near-infrared images. A 1-dimensional bulge/disk decomposition is performed on
the near-infrared images of galaxies with a non-negligible bulge component, and
an exponential disk is fit to the radial surface brightness profiles of the
remaining galaxies.Comment: 28 page
Myth of the Industrial Scrap Heap: A Revisionist View of Turn-of-the- Century American Retirement
Using the census survival method to calculate net flows across employment states between 1900 and 1910, we find that approximately one-fifth of all men who reached the age of 55 eventually retired before their death. Many of these retirees appear to have planned their withdrawal from paid employment by accumulating assets, becoming self-employed, and then liquidating their assets to provide a stream of income to finance consumption in old age. This `modern' retirement behavior, we argue, has important implications for the economic history of capital and labor markets, of saving and investment, of insurance and pensions, and of the family economy.
Historical Perspectives on the Economic Consequences of Immigration into the United States
This paper highlights the distinctive features of the theoretical approach taken by scholars" who analyzed the impacts of the mass migration into the United States in the two decades" preceding World War I. Broadly speaking, this literature was couched in terms of the "aggregate" production function, productivity change in factor proportions. Attention was focused on the close interrelatedness among the many" diverse elements in the economy. A notable difference between the historical studies and the recent literature on the impacts" of immigration is the propensity of the current literature to concentrate only on the first-round" consequences. It is easy to show that these will be harmful to resident workers who face direct" competition. Economic historians writing about the earlier period of high immigration went" beyond the first-round effects. Taking a long-run perspective, they identified many aspects of" the mass immigration that were beneficial from the point of view of the resident population."
Fixing the Facts: Editing of the 1880 U.S. Census of Occupations with Implications for Long-Term Trends and the Sociology of Official Statistics
We argue that the enumerators' occupational returns from the important census of 1880 were heavily edited prior to publication. The effect was to substantially reduce the number of individuals reported with an occupation. For youthful and older males and all women the editing was so substantial as to qualitatively affect the apparent trend in labor force participation for these groups over time. The stylized facts regarding labor market dynamics during the period of American industrialization and the historical stories constructed around them will now need to be reexamined. We contend that the editing was secretly authorized by Francis Amasa Walker, Superintendent of the Tenth Census of 1880 and one of the most prominent and decorated economists, statisticians, and public servants in America at this time. While other scholars have identified potential sources of bias in census figures, no one has heretofore suggested that the official statistics of the United States were covertly altered to present a picture different from information collected by census enumerators. If we are correct, the sociology of official nineteenth-century American statistics will require rethinking.
USM3D Simulations for Second Sonic Boom Workshop
The NASA Tetrahedral Unstructured Software System with the USM3D flow solver was used to compute test cases for the Second AIAA Sonic Boom Prediction Workshop. The intent of this report is to document the USM3D results for SBPW2 test cases. The test cases included an axisymmetric equivalent area body, a JAXA wing body, a NASA low boom supersonic configuration modeled with flow through nacelles and engine boundary conditions. All simulations were conducted for a free stream Mach number of 1.6, zero degrees angle of attack, and a Reynolds number of 5.7 million per meter. Simulations were conducted on tetrahedral grids provided by the workshop committee, as well as a family of grids generated by an in-house approach for sonic boom analyses known as BoomGrid using current best practices. The near-field pressure signatures were extracted and propagated to the ground with the atmospheric propagation code, sBOOM. The USM3D near-field pressure signatures, corresponding sBOOM ground signatures, and loudness levels on the ground are compared with mean values from other workshop participants
Experimental and Computational Sonic Boom Assessment of Boeing N+2 Low Boom Models
Near-field pressure signatures were measured and computational predictions made for several sonic boom models representing Boeing's Quiet Experimental Validation Concept (QEVC) supersonic transport, as well as three axisymmetric calibration models. Boeing developed the QEVC under a NASA Research Announcement (NRA) contract for Experimental Systems Validations for N+2 Supersonic Commercial Transport Aircraft, which was led by the NASA High Speed Project under the Fundamental Aeronautics Program. The concept was designed to address environmental and performance goals given in the NRA, specifically for low sonic boom loudness levels and high cruise efficiency, for an aircraft anticipated to enter service in the 2020 timeframe. Wind tunnel tests were conducted on the aircraft and calibration models during Phases I and II of the NRA contract from 2011 to 2013 in the NASA Ames 9- by 7-Foot and NASA Glenn 8- by 6-Foot Supersonic Wind Tunnels. Sonic boom pressure signatures were acquired primarily at Mach 1.6 and 1.8, and force and moment data were acquired from Mach 0.8 to 1.8. The sonic boom test data were obtained using a 2-in. flat-top pressure rail and a 14-in. round-top tapered "reflection factor 1" (RF1) pressure rail. Both rails capture an entire pressure signature in one data point, and successive signatures at varying positions along or above the rail were used to improve data quality through spatial averaging. The sonic boom data obtained by the rails were validated with high-fidelity numerical simulations of off-body pressures using the CFD codes USM3D, Cart3D, and OVERFLOW. The test results from the RF1 rail showed good agreement between the computational and experimental data when a variety of testing techniques including spatial averaging of a series of pressure signatures were employed, however, reflections off the 2-in. flat-top rail caused distortions in the signatures that did not agree with the CFD predictions. The 9 x 7 and 8 x 6 wind tunnels generally produced comparable data
The potential of painting: unlocking Disenfranchised Grief for people living with dementia
As part of the “Creative Well” programme at Betsi Cadwaladr University Health Board (BCUHN) North Wales, artist/researchers Megan Wyatt and Susan Liggett qualitatively investigated how painting can access a means of communication for people living with Dementia. In a workshop setting within a gallery environment at Ruthin Crafts Centre, participants living with dementia were facilitated on a one to one basis the opportunity to paint alongside the artist/researchers. The participants were from a wellestablished art group called “Lost in Art” that is managed by Denbighshire Arts Service.
During the workshops, a number of experiences were articulated. These included experiences of illness, crisis and loss. They were captured through observations, interviews, visual art and video to contribute to new understandings and models of engagement through art for people living with dementia and their carers.
Focusing on theory and practice in arts based research and the social sciences, this paper investigates the potential of painting to unlock experiences such as disenfranchised grief for people living with dementia. The conclusions do not measure how and if participants felt disenfranchised grief but rather provide an alternative to augment the body of knowledge surrounding how people living with dementia can communicate feelings of disenfranchised grief through painting.
Objective: In this presentation I aim to outline the main findings from the above paper that is to be published in an academic journal later in the year on Illness Crisis and Loss published by Sage
Alteration of the Gut Microbiome in Normal and Overweight School Children from Selangor with \u3ci\u3eLactobacillus\u3c/i\u3e Fermented Milk Administration
Childhood obesity is a serious public health problem worldwide. Perturbations in the gut microbiota composition have been associated with the development of obesity in both children and adults. Probiotics, on the other hand, are proven to restore the composition of the gut microbiome which helps reduce the development of obesity. However, data on the effect of probiotics on gut microbiota and its association with childhood obesity is limited. This study aims to determine the effect of probiotics supplement intervention on gut microbiota profiles in obese and normal-weight children. A total of 37 children, 17 normal weight, and 20 overweight school children from a government school in Selangor were selected to participate in this study. Participants were further divided into intervention and control groups. The intervention groups received daily probiotic drinks while the control groups continued eating their typical diet. Fecal samples were collected from the participants for DNA extraction. The hypervariable V3 and V4 regions of 16S rRNA gene were amplified and sequenced using the Illumina MiSeq platform. No significant differences in alpha diversity were observed between normal weight and obese children in terms of the Shannon Index for evenness or species richness. However, a higher intervention effect on alpha diversity was observed among normal-weight participants compared to obese. The participants’ microbiome was found to fluctuate throughout the study. Analysis of the taxa at species level showed an increase in Bacteroides ovatus among the normal weight cohort. Genus-level comparison revealed a rise in genus Lachnospira and Ruminococcus in the overweight participants after intervention, compared to the normal-weight participants. The probiotics intervention causes an alteration in gut microbiota composition in both normal and overweight children. Though the association could not be defined statistically, this study has provided an improved understanding of the intervention effect of probiotics on gut microbiome dysbiosis in an underrepresented population
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