Plant Productivity Dispersion and the College Premium: Evidence from the United States 1977-1997

2015 ◽  
Author(s):  
Damir Stijepic
Keyword(s):  
United States ◽  
Plant Productivity ◽  
The United States ◽  
College Premium

scholarly journals Trends in Quality-Adjusted Skill Premia in the United States, 1960–2000

2011 ◽  
Vol 101 (6) ◽  
pp. 2309-2349 ◽  
Author(s):  
Pedro Carneiro ◽  
Sokbae Lee
Keyword(s):  
United States ◽  
College Enrollment ◽  
College Graduates ◽  
The United States ◽  
Average Quality ◽  
Demand And Supply ◽  
Percentage Points ◽  
New Evidence ◽  
College Premium

This paper presents new evidence that increases in college enrollment lead to a decline in the average quality of college graduates between 1960 and 2000, resulting in a decrease of 6 percentage points in the college premium. A standard demand and supply framework can qualitatively account for the trend in the college and age premia over this period, but substantial quantitative adjustments are needed to account for changes in quality. (JEL I23, J24, J31)

scholarly journals Estimation of Ultraviolet-A Irradiance from Measurements of 368-nm Spectral Irradiance

2005 ◽  
Vol 22 (12) ◽  
pp. 1853-1863 ◽  
Author(s):  
R. H. Grant ◽  
J. R. Slusser
Keyword(s):  
United States ◽  
Radiative Transfer ◽  
Plant Productivity ◽  
The United States ◽  
Spectral Irradiance ◽  
Radiative Transfer Model ◽  
Mean Bias Error ◽  
Transfer Model ◽  
Semiempirical Model ◽  
Ultraviolet A

Abstract The estimation of ultraviolet-A (UV-A) radiation across the earth’s surface is needed to model plant productivity and future impacts of ultraviolet-B radiation on plant productivity. We have developed two models to estimate the UV-A irradiance from measurements of the diffuse and global spectral irradiance at 368 nm. The models were developed from 30-min-interval measurements made throughout 2000 at three locations across the United States and evaluated from 30-min measurements made throughout 2000 at three additional locations and throughout 2001 and 2002 at seven locations. UV-A irradiance was best estimated from measured global 368-nm irradiance and empirical functions defining the UV-A and 368-nm irradiance values estimated from a theoretical pseudospherical two-stream discrete-ordinates radiative transfer model. The radiative transfer model provided baseline irradiance relationships between UV-A irradiance and 368-nm spectral irradiance. The semiempirical model estimated the UV-A irradiance at seven locations across the United States with a mean bias error of 0.5 W m−2 and a root-mean-square error of 2 W m−2, corresponding to approximately ±4% of a clear-sky irradiance of 50 W m−2 for a solar zenith angle of 30°. This model error was comparable to the combined effect of previously estimated UV-A and 368-nm irradiance measurement errors.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

Digital image acquisition, processing, and analysis in a polymer microscopy laboratory

1994 ◽  
Vol 52 ◽  
pp. 454-455
Author(s):  
Vinod K. Berry ◽  
Xiao Zhang
Keyword(s):  
United States ◽  
Image Analysis ◽  
Digital Image ◽  
Image Acquisition ◽  
Image Transmission ◽  
The United States ◽  
Quantitative Image Analysis ◽  
Quantitative Image

In recent years it became apparent that we needed to improve productivity and efficiency in the Microscopy Laboratories in GE Plastics. It was realized that digital image acquisition, archiving, processing, analysis, and transmission over a network would be the best way to achieve this goal. Also, the capabilities of quantitative image analysis, image transmission etc. available with this approach would help us to increase our efficiency. Although the advantages of digital image acquisition, processing, archiving, etc. have been described and are being practiced in many SEM, laboratories, they have not been generally applied in microscopy laboratories (TEM, Optical, SEM and others) and impact on increased productivity has not been yet exploited as well.In order to attain our objective we have acquired a SEMICAPS imaging workstation for each of the GE Plastic sites in the United States. We have integrated the workstation with the microscopes and their peripherals as shown in Figure 1.

Silence of the Land: On the Historical Irrelevance of Territory to Congressional Districting and Political Representation in the United States

2001 ◽  
Vol 15 (01) ◽  
pp. 53-87 ◽  
Author(s):  
Andrew Rehfeld
Keyword(s):  
United States ◽  
House Of Representatives ◽  
Political Representation ◽  
The United States ◽  
Representative Government ◽  
Congressional District ◽  
Congressional Districts ◽  
Communities Of Interest

Every ten years, the United States “constructs” itself politically. On a decennial basis, U.S. Congressional districts are quite literally drawn, physically constructing political representation in the House of Representatives on the basis of where one lives. Why does the United States do it this way? What justifies domicile as the sole criteria of constituency construction? These are the questions raised in this article. Contrary to many contemporary understandings of representation at the founding, I argue that there were no principled reasons for using domicile as the method of organizing for political representation. Even in 1787, the Congressional district was expected to be far too large to map onto existing communities of interest. Instead, territory should be understood as forming a habit of mind for the founders, even while it was necessary to achieve other democratic aims of representative government.

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