Differential Reaction of Larvae of the Western Corn Rootworm to Certain Species of Gramineae

Forty-four species of grass, 12 species of broadleaf weeds, and 15 species of broadleaf crops were screened as possible hosts of the larvae of the western corn rootworm, Diabrotica virgifera LeConte. The larve did not survive on any of the broadleaf species, but they were able to complete their immature stages on 13 grass species. Corn was the most favorable host for larval development as indicated by the number and relative size of the beetles recovered. Viable eggs were obtained from females reared as larvae on all hosts. Clean cultivation should play a role in rootworm control since 2 of the most common field weeds; green foxtail, Setaria viridis (L.) Beauv., and yellow foxtail, S. Lutescens (Weigel) Hubb; are both hosts. Broadleaf crops as well as oats, Avena sativa L., and sorghum, Sorghum vulgare Pers., can be safely used in rotation with core since they are not hosts of corn rootworm larvae. But some narrowleaf crop species (wheat, Triticum aestivum L.; spelt, T. spelta L.; barley, Hordeum vugare L.; foxtail millet, Setaria italic [L.} Beauv.; intermediate wheatgrass, Agropyron intermedium [Host] Beauv.; pubescent wheatgrass, A. trachycaulum [Link] Malte) would be injured by rootworm larvae if they were planted in egg-laden fields. Eight of the near relatives of corn from the tribe Tripsaceae (Maydeae) were intensively screened as possible sources of resistant germplasm. Adults were recovered from all of the species tested, but there appeared to be a vast difference between members of the tribe in their ability to support rootworm larvae. Tripsacum dactyloides (L.) L. appeared to be the only species tested that had a high degree of resistance to larvae of the western corn rootworm. The resistance is due to antibiosis or nonpreference and can perhaps be transferred to corn if it is not too complexly inherited. Tests were conducted to determine why some grasses were not hosts of the larvae. Olfactometer tests of both hosts and nonhosts indicated that all grasses tested attracted corn rootworm larvae up to a distance of 50 mm and that some of the grasses were significantly more attractive than corn roots. Lack of attractancy or repellency was apparently not involved in the nonhost status. Tests with maxillectomized larvae, maxillectomized and labiumectomized larvae, and normal larvae indicated that none of these ingested an appreciable amount of the roots of oats. The maxillary palpi for western corn rootworm larvae were important in the detection of sucrose (a feeding stimulant), and appeared to inhibit feeding when sucrose was absent. However, the maxillae were not the only receptors that detected sucrose absence by receptors other than the maxillary palpi. Laser radiation was used to maxillectomize the rootworm larvae. This technique may be useful in maxillectomizing other small insects and in studying the function of other sense organs. The roots of sorghum were found to be toxic to the larvae of the western corn rootworm. Preliminary tests suggested that the toxin involved was hydrocyanic acid. Other experiments showed that free cyanide was toxic to the larvae when it was ingested at a level of 10 ppm. Cyanogenetic glucosides were not toxic to larvae when ingested at a level equivalent to 2000 ppm cyanide unless appropriate hydrolytic enzymes were present. Toxic levels of hydrocyanic acid probably result during larval feeding on sorghum roots because of the action of beta glucosidase of endogenous cyanogenetic glucosides such as dhurrin

Feeding Alfalfa to South Carolina Dairy Herds

The nutritional value of alfalfa hay is important if it is to be used competitively with other feedstuffs in rations being fed to South Carolina Dairy Herds. Excellent quality hay has high nutrient concentration, digestibility and intake. The appearance of good physical characteristics of alfalfa hay as well as other hays and forages along with the knowledge of harvest dates, stages of maturity, and other conditions are not enough and can be deceiving. Therefore, forage testing is crucial and very important

Hydrogen sulfide plasma passivation of gallium arsenide

Improvement in the electrical properties of the GaAs surface has been accomplished using a room‐temperature hydrogen sulfide plasma. The surface has then been protected by a 300 °C plasma enhanced chemical vapor deposition (PECVD) SiO2 film. This treatment is highly reproducible due to computer control of process parameters and long‐lasting due to the SiO2 cap. Improved C‐V characteristics were observed, showing interface trap densities in the high 1011 cm−2 eV−1 range. Photoluminescence (PL) measurements on the sulfided samples showed increased intensity over the untreated samples.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71276/2/APPLAB-60-6-716-1.pd

A hybrid analysis of ellipsometry data from patterned structures

Rigorous coupled wave analysis (RCWA) has been used for modeling the polarization dependent reflection from periodic patterns for process monitoring and control. However, the computational load of this vector method is very heavy. In this paper, we will carefully examine a much simpler scalar method for reflection modeling. We also extend the application of the vector analysis to some special non-periodic structures by combining RCWA with the scalar model. We conclude that this hybrid approach is of significant promise for in situ IC production applications. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87397/2/373_1.pd

Evaluation of Gerard Langbaine the Critic

Englis

Interference fringe-free transmission spectroscopy of amorphous thin films

Based on optical fundamentals, we present in this article a practical method to obtain an interference fringe-free transmission spectrum for hydrogenated amorphous solid thin films. From this spectrum, reliable optical properties, such as the Urbach edge and optical band gap of the thin films, can be extrapolated directly. In terms of the Brewster angle accuracy, the margins of error of the proposed method due to material dispersion are less than ±1%±1% for hydrogenated amorphous silicon and less than ±1.2%±1.2% for hydrogenated amorphous silicon nitride. These figures are less than the detectable limit of the proposed method. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70510/2/JAPIAU-88-10-5764-1.pd

Electrospinning of food-grade nanofibres from whey protein

In this study, electrospinning has been employed to produce micro to nano scale fibres of whey protein in order to investigate their potential for use in the food industry. Initially, spinning of purewhey protein proved challenging; so in order to facilitate the spinning of freshly prepared aqueous solutions, small amounts of polyethylene oxide (as low as 1% w/w in solution) were incorporated in the spinning solutions. The electrospun composite polyethylene-oxide/whey fibres exhibited diameters in the region of 100 to 400 nm, showing the potential to build fibre bundles from this size up. Time-dependent examinations of pure whey protein aqueous solutions were conducted using rheometery and small angle neutron scattering techniques, with the results showing a substantial change in the solution properties with time and stirring; and allowing the production of fibres, albeit with large diameters,without the need for an additive. The spinability is related to the potential of thewhey protein composites to form aggregate structures, either through hydration and interaction with neighbouring proteins, or through interaction with the polyethylene oxide

Analysis of reflectometry and ellipsometry data from patterned structures

Specular reflected light techniques, including both single wavelength and spectroscopic versions of ellipsometry and reflectometry, have been used for both etch and growth rate control. However, use of these techniques for process control on products has been limited due to the problems inherent in the analysis of reflected light from patterned structures. In this paper, we examine techniques for the quantitative analysis of data from both highly regular grating structures and from patterns with low local order. We find good quantitative agreement of vector diffraction theory to specular reflection data. We conclude that there is significant promise for the use of specular techniques for in situ monitoring of topography provided that computational speed issues can be improved. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87552/2/331_1.pd

Global forms and local forces : PhD enrollments and graduations in Australia, Canada, the Czech Republic, the United Kingdom, and the United States

 This chapter presents and discusses data from five different nations—Australia, Canada, the Czech Republic, the United Kingdom, and the United States—on doctoral candidates and graduates. These data are from governmental and institutional sources for the years 1998–2004, a sample that enables changes across a five-year span to be identified. They span important basic characteristics, such as gender, age, discipline, and study load (that is, full-time or part-time study). Therefore, readers can see national as well as international trends and differences in such characteristics and can match these to equivalent and/or contemporary data in their own nations. The five countries considered here are among those whose data were discussed at the 2007 CIRGE research synthesis meeting in Australia. Although these countries are not universally representative of doctoral education, their practices do offer a vivid sense of how vastly the enterprise of doctoral education differs in its scope and dimensions around the worl