A Comparison of Changes in the Structure of Wages

This paper compares changes in the structure of wages in France, Great Britain, Japan. and the United States over the last twenty years. Wage differentials by education and occupation (skill differentials) narrowed substantially in all four countries in the 1970s. Overall wage inequality and skill differentials expanded dramatically in Great Britain and the United States and moderately in Japan during the 1980s. In contrast, wage inequality did not increase much in France through the mid-1980s. Industrial and occupational shifts favored more-educated workers in all four countries throughout the last twenty years. Reductions in the rate of the growth of the relative supply of college-educated workers in the face of persistent increases in the relative demand for more-skilled labor can explain a substantial portion of the increase in educational wage differentials in the United States, Britain, and Japan in the 1980s. Sharp increases in the national minimum wage (the SM1C) and the ability of French unions to extend contracts even in the face of declining membership helped prevent wage differentials from expanding in France through the mid-1980s.

Mid-infrared quantum optics in silicon

Applied quantum optics stands to revolutionise many aspects of information technology, provided performance can be maintained when scaled up. Silicon quantum photonics satisfies the scaling requirements of miniaturisation and manufacturability, but at 1.55 $\mu$m it suffers from unacceptable linear and nonlinear loss. Here we show that, by translating silicon quantum photonics to the mid-infrared, a new quantum optics platform is created which can simultaneously maximise manufacturability and miniaturisation, while minimising loss. We demonstrate the necessary platform components: photon-pair generation, single-photon detection, and high-visibility quantum interference, all at wavelengths beyond 2 $\mu$m. Across various regimes, we observe a maximum net coincidence rate of 448 $\pm$ 12 Hz, a coincidence-to-accidental ratio of 25.7 $\pm$ 1.1, and, a net two photon quantum interference visibility of 0.993 $\pm$ 0.017. Mid-infrared silicon quantum photonics will bring new quantum applications within reach.Comment: 8 pages, 4 figures; revised figures, updated discussion in section 3, typos corrected, added referenc

A Possible protective effect of nut consumption on risk of coronary heart-disease: the adventist health study

Background -Although dietary factors are suspected to be important determinants of coronary heart disease (CHD) risk, the direct evidence is relatively sparse. Methods. -The Adventist Health Study is a prospective cohort investigation of 31 208 non-Hispanic white California Seventh-Day Adventists. Extensive dietary information was obtained at baseline, along with the values of traditional coronary risk factors. These were related to risk of definite fatal CHD or definite nonfatal myocardial infarction

Remote Sensing of Parasitic Nematodes in Plants

A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken

Polypropylene pipe interface strength on marine sandy soils with varying coarse fraction

The interface shear strength of polypropylene pipeline coatings and marine sandy soils was investigated through direct and surface-over-soil interface shear box testing. Polypropylene specimens were acquired by removal from existing manufactured steel pipes and test soils were fabricated to closely resemble typical compositions and particle size distributions of North Sea marine sediments. The test sands varied according to their coarse particle fractions, with 0, 15 and 35% being retained on a 0·4 mm sieve. Testing was carried out at the very low stresses pertinent to pipeline interfaces, between 2·5 and 37·5 kPa, in both loose and dense states. The experimental results suggest a dependency of the interface shear strength on the stress level and relative density, with the coarse particle fraction playing a modest role. Surface characterisation and lack of volumetric deformation suggests that the shearing kinematic is predominantly grain sliding rather than rolling. Interface efficiency was largely constant despite some scatter due to variability in surface specimens. The distinct seams apparent on some of the polypropylene surfaces as inherent manufacturing artefacts had a negligible influence on interface strength. The relationship between interface strength, normalised roughness and Shore D hardness was assessed, discussed and compared with results from other works

Proceedings of the 17th Annual Meeting, Southern Soybean Disease Workers (March 20-22, 1990, Biloxi, Mississippi): Soybean Disease Control at a Crossroad

Contents Southern Soybean Disease Workers Officers 1989-1990 Southern Soybean Disease Workers Program Committee 1989-1990 Southern Soybean Disease Workers Committee Chairmen 1989-1990 General session Presidential address. B Gazaway Keynote address. K Smith Invited speakers Future Impacts of Biotechnology on Soybean Production and Uses. X Delannay Diseases of Soybean Associated with International Seed Trade. B Moore Impact of Regulatory Change and GLP\u27s on New Fungicide Discovery and Development. G Hammes Graduate student papers Double-Stranded RNA and Virus-Like Particles From the Soybean Stem canker Pathogen, Diaporthe phaseolorum var. caulivora. Y Lee, JP Snow, GT Berggren, and RA Valverde Development of Soybean Varieties Resistant to Phomopsis Seed Decay. MS Zimmerman and HC Minor Cloning of the vir Region of Agrobacterium tumefaciens Chry 5, a Strain Highly Virulent on Soybean. LG Kovacs, JA Wrather, and SG Pueppke Role of Overwintering Bean Leaf Beetle in the Epidemiology of Bean Pod Mottle Virus in Soybeans in Kentucky. JR dosAnjos, SA Ghabinal, DE Hershman, and DW Johnson Contributed papers SSDW soybean Disease Loss Estimates G Sciumbato Effects of Amino Acid Biosynthesis Inhibiting Herbicides on in vitro Growth and Development of Calonectria crotalariae. DK Berner, GT Berggren, and JP Snow Infection Cushion Formation by Rhizoctonia solani on Soybean Leaves. CS Kousik, JP Snow, and GT Berggren Is Stem Canker Monocyclic? KV SubbaRao, JP Snow, and GT Berggren Early-season Fungicide Sprays for Soybean Stem Canker Control. AY Chambers SSDW business session Treasurer\u27s report, 1989. G Hammes Contributed paper session Effect of Frogeye Leaf Spot on Soybeans in Florida. FM Shakes and CK Hiebsch Comparison of Application Timing of Two Foliar Fungicides for Control of Soybean Diseases. JC Rupe and MJ Cochran Performance of Soybean Lines under Stress Due to Brown Stem Rot, Soybean Cyst Nematode, and Iron Deficiency Chlorosis. LM Mansur, H Tachibana, and K Bidne Performance of Soybean Cultivars in Cyst and Peanut Root-Knot Nematode Infested Fields. CE Drye, DK Barefield, ER Shipe, and JD Mueller Yield of Aldicarb Treated Nematode Resistant and Susceptible Soybean Varieties. CE Drye, ER Garner, and JD Mueller Distribution, Races, and Effects of Soybean Cyst Nematode in Missouri. TL Niblack and GS Smith Performance of Selected Nematicides in a Field Infested with Root-Knot and Cyst Nematodes. RW Young, R Rodríguez-Kábana, and EL Carden Performance of Selected Soybean Cultivars in a Field Infested with Meloidogyne arenaria and Heterodera glycines. DG Robertson, R Rodríguez-Kábana, D Weaver, and EL Carden Sorghum-Soybean Rotation for the Management of Root-Knot and Cyst Nematodes: Long Term Effects. CF Weaver, R Rodríguez-Kábana, DB Weaver, and EL Carden Bahiagrass-Soybean Rotation for the Management of Root-Knot and Cyst Nematodes: Long Term Effects. PS King, R Rodríguez-Kábana, DB Weaver, and EL Carden Peanut-Soybean Rotations for the Management of Meloidogyne arenaria. R Rodríguez-Kábana, and DG Robertson Field Evaluation of Polyspecific Nematode Resistance in Soybean. DB Weaver, R Rodríguez-Kábana, and EL Carden Long Term Effects of Selected Rotations with Soybeans and Corn on Populations of Meloidogyne arenaria. R Rodríguez-Kábana, and D.G. Robertson Histopathology of Soybean Roots Inoculated with Fusariurn solani and Heterodera glycines. KS McLean, KW Roy and GW Lawrence. The opinions expressed by the participants at this conference are their own and do not necessarily represent the views of the southern Soybean Disease Workers (SSDW). Text, references, figures, and tables are reproduced essentially as they were supplied by the author(s) of each paper. Mention of pesticides does not constitute a recommendation for use, nor does it imply that the pesticides are registered under the Federal Insecticide, Fungicide, and Rodenticide Act as · amended. The use of trade names in this publication does not constitute a guarantee, warranty, or endorsement of the products by SSDW

Winter Mass Mortality of Animals in Texas Bays

The Texas coast experienced three unusually cold weather periods in the 1980\u27s, one in 1983 and two in 1989, that caused massive fish kills. Identification of organisms killed and estimation of the number of estuarine fishes and invertebrates killed was accomplished through a systematic standardized approach utilizing airplanes, ground qualitative observations and quantitative counts, and trawling. Of 159 species identified, 103 were fishes, 45 were invertebrates, and 11 were vertebrates other than fishes. About 14 million fishes were killed in December 1983, 11 million in February 1989 and 6 million in December 1989; number of invertebrates killed ranged from 13,000 in February 1989 to 1,000,000 in 1983. These assessments are the largest in area and most comprehensive to be documented in the literature with known levels of precision. Methodology used provides reasonably precise estimates which managers can use to assess extensive widespread kills and subsequent impacts on affected populations. It is recommended that managers consider reducing fishing mortality on the remaining economically important populations after extensive kills to speed recovery of those populations