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By employing the Hankel transform of a radial ground current, the Zenneck surface wave, which is a non-radiating guided-wave mode, is derived. We report on its use in our replication of the ‘crucial’ Seneca Lake experiment of 1936, which had been used to vindicate the Sommerfeld sign error myth, and which has implications in efficient wireless power transfer over great distances.

Neurons are distinctive in that they are generally considered to be permanently post-mitotic cells. The oncoprotein p53 is a key regulator in neuronal development, notably in cell proliferation and neuronal death. We hypothesize that p53 maintains the post-mitotic characteristic of differentiated neurons. New lines of conditionally immortalized cortical cells were generated to test this hypothesis. Populations of cells were obtained from the neocortices of dual transgenic mice that were null for p53 and expressed a temperature-sensitive SV40 large T antigen. At a permissive temperature (32 degrees C), the cells continued to proliferate and most expressed nestin and proteins associated with glia. At a non-permissive temperature (39 degrees C), the cells expressed cytoskeletal proteins associated with differentiated neurons such as microtubule associated protein 2 and neurofilament 200. Under permissive conditions, both p53(+/-) and p53(-/-) cells exhibited similar cycling behaviors; the length of the cell cycle was 13-15 h and85% of the cells were actively cycling. In non-permissive conditions, most p53(+/-) cells stopped dividing, whereas the p53(-/-) cells continued to proliferate. The survival of the cells also differed. In the non-permissive conditions, many p53(+/-) cells died following treatment with a neurotoxin (ethanol, 400 mg/dl), whereas the p53(-/-) cells did not. After re-introduction to the permissive conditions, both cell lines expressed neuron-like characteristics, but only the p53(-/-) cells retained their ability to cycle. Therefore, p53-mediated activities appear to be involved in the proliferation, survival, and post-mitotic nature of neuron-like cells.

Chorio-allantoic membranes (CAMS) were collected and analyzed for chlorinated hydrocarbons as part of a wildlife toxicology demonstration project at Naval Air Station (NAS) Whidbey Island, Washington, USA. Concentrations of DDT, DDE, DDD, Aroclor 1254, and Aroclor 1260 were found at concentrations below 0.4 ppm for 13 of 14 samples. The low correlations among DDT and its metabolites in CAMS suggest herons are not being exposed to a consistent source of these compounds. Comparison of chlorinated hydrocarbon data for CAMS from three Puget Sound heron colonies, NAS Whidbey, Samish Island and Dumas Bay, indicates contaminant burdens in herons from NAS Whidbey and Samish Island are significantly lower than burdens in herons from Dumas Bay.

We describe a simulation model designed to study the effects of helicopter disturbance on molting Pacific black brant near Teshekpuk Lake, Alaska. Locations of 18118 brant were digitized into the model based on 10 years of population survey data. Bell 206 and Bell 412 helicopters were simulated flying across the molting grounds along two routes between two airfields. The model determined the behavioral and energetic response of birds encountered by the aircraft during an overflight. Altitude and frequency of overflights were held constant during a simulated 28-day molting period, but were varied among simulations. The model provided the degree of weight loss these birds experienced due to helicopter disturbance. The effects of overflights on brant were classified into five risk categories based on weight. For both routes, the number of flocks and birds in each category was determined for each altitude, aircraft type, and overflight frequency. Simulation results indicated that the model can be used to identify flight-line modifications that result in significantly decreased disturbance to the birds.

A sophisticated selective mechanism that regulates nuclear-cytoplasmic traffic has evolved in eukaryotes which circumvents the formidable barrier presented by the nuclear envelope. The sites of RNA and protein exchanges are the nuclear pore complexes (NPCs), 125 MDa supramolecular assemblies inserted into the envelope (see recent reviews by Dingwall, 1991; Goldfarb and Michaud, 1991; Miller et al., 1991; Nigg et al., 1991). In this article, the role NPCs play in regulating intracellular macromolecular traffic will be discussed.

In August of 1995, the Johns Hopkins University (JHU) Applied Physics Laboratory (APL) and Orbital Sciences Corporation (Orbital) entered into a fixed-price contract to develop the spacecraft bus for the Far Ultraviolet Spectroscopic Explorer (FUSE). Since that time, Orbital and JHU have worked together to perform the design, analysis, procurement, fabrication, and subsystem integration as an example of how a Principal Investigator led team can work. The FUSE spacecraft is currently undergoing final Integration and Test at Orbital's Germantown, Maryland Facility in preparation for delivery to APL by April, 1998 with launch in October, 1998. This paper describes the process and partnership formed by Orbital and JHU in this development activity, the resulting spacecraft characteristics, and the lessons learned from this program to date.

Summarizes project to design and build aileron retrofit blades for a 600 kW upwind, teetered rotor, full-span pitch control, horizontal-axis wind turbine.

Publisher Summary This chapter focuses on Nadsonia genus and its member species. The cells in this genus are lemon-shaped, ovoidal, or elongate and the vegetative reproduction occurs by bud-fission at both poles, which involves the formation of a bud-like structure on a very wide neck. The bud is separated by the formation of a cross wall, followed by fission. Ascospore formation involves two mechanisms. In the first case, the contents of the zygote move into another bud formed at the opposite end of the parent cell after a heterogamic conjugation between the parent cell and a bud. This second bud is then delimited by a septum and becomes the ascus. In the second mechanism, the bud is normally delimited by a septum and the parent cell becomes the ascus, after a heterogamic conjugation between the parent cell and a bud. The member species of this genus include Nadsonia commutata and Nadsonia fulvescens, which again has two variants including Nadsonia fulvescens var. fulvescens and Nadsonia fulvescens var. elongata. Asci in Nadsonia commutata are formed by the second mechanism, following lysis of the wall separating a parent cell and a polar bud. The nucleus and other contents of the bud pass into the parent cell where karyogamy and meiosis take place.

Publisher Summary This chapter focuses on Saccharomycodes genus and its member species. The cells of this species are large, diploid, lemon-shaped (apiculate) or elongate cells, which reproduce by bipolar budding on a very broad base (bud-fission). Pseudomycelium is absent or poorly developed. The spores are spheroidal with an apparently smooth wall and a narrow subequatorial ledge and irregularly spaced surface nodules may be visible. The asci usually contain four spores, occurring in two pairs, and upon germination, members of each pair ordinarily conjugate. In some strains, the spores may germinate without conjugation. The sole member species of this genus is Saccharomycodes ludwigii . The cells of this species, after three days of growth in 5% malt extract at 25° C, may appear as lemon-shaped with blunt tips, sausage-shaped, curved, broad-oval, or elongated with a swelling in the middle. The cells are single or in pairs and sometimes in groups ofthree. The spores of this species are spheroidal and smooth with a narrow subequatorial ledge, which is visible in sections viewed in the electron microscope. In freeze-fracture replicas, the outer surface of the spores shows irregularly spaced nodules. Usually, there are four spores per ascusin two groups of two, although some strains produce two spores per ascus.

Publisher Summary This chapter focuses on Phaffia genus, whose vegetative cells are ellipsoidal and occur singly, in pairs, and occasionally in short chains, and reproduce by enteroblastic budding. Carotenoid pigments are synthesized (mainly astaxanthin and a minor proportion of P-carotene), which give cells en masse a red to salmon-red color. Phaffia appears to have a restricted geographic distribution, nine strains of which were isolated in the mountainous locations in a wide area of Japanese islands and a single strain came from Alaska, U.S.A. The only member species of this genus is Phaffia rhodozyma. Because of its high astaxanthin content, Phaffia rhodozyma has been used as a dietary pigment source to impart the desirable orange-red color to the normally white flesh of pen-reared salmonids and crustaceans.

Publisher Summary This chapter focuses on Metschnikowia and its member species. The cells of this genus are spheroidal to ellipsoidal, as well as pyriform, cylindroid, or lunate. Vegetative reproduction in this genus occurs through multilateral budding. Its asci are elongate and its ascospores are needle-shaped, attenuate at one or both ends, and without a whip-like appendage. Some species are parasitic in invertebrates, as well as free-living in aquatic habitats, while others are terrestrial, free-living, and often associated with flowers. The sugars are fermented by most species and nitrate is not assimilated. The member species of this genus include Metschnikowia agaves; Metschnikowia australis; Metschnikowia bicuspidata including its three variants Metschnikowia bicuspidata, Metschnikowia bicuspidata var. californica, and Metschnikowia bicuspidata var. chathamia; Metschnikowia gruessii; Metschnikowia hawaiiensis; Metschnikowia krissii; and Metschnikowia lunata. The Metschnikowia agaves species, after one day on yeast carbon base agar (without added nitrogen source) and mixed strains of complementary mating types, give rise to long (several cell lengths) conjugation tubes, or elongated cells. After 3 days at 25° C, mature asci are observed that are pleomorphic in shape but are usually quasi-cylindrical and conjugated. In the case of Metschnikowia australis, a large clavate ascus develops containing two acicular spores after the conjugation of two haploid cells of complementary mating types.

Publisher Summary This chapter focuses on Eremothecium genus and its constituent species. The budding cells of this genus are absent or present, and when present, budding is multilateral on a narrow base. The cells are globose, ovoidal, ellipsoidal, or cylindroidal. Its asci, which become deliquescent, form 8-32 ascospores that are fusiform or acicular. Ascospores may have a central septum, and those of some species have a tapered, terminal extension of the cell wall. The sugars are fermented by some species and nitrate is not assimilated. The constituent species of this genus include Eremothecium ashbyi, Eremothecium coryli, Eremothecium cymbalari, and Eremothecium gossypii. The asci of Eremothecium ashbyi are ellipsoidal to fusiform, and occur mostly intercalary and in long chains. The ascospores are evenly distributed in the ascus, and are hyaline, narrow, sickleshaped, rounded at the tip, but with a basal spine. The Asci in Eremothecium coryli are long, curved cylindrical cells with rounded ends, although they are sometimes of irregular shape. Examination under the light microscope reveals the presence of vacuoles and a difference of refringence between the two halves of the spores. When stained with the Ziehl–Neelsen or the Schaeffer–Fulton malachite green technique, the half supporting the whip-like appendage is not acid fast and does not retain the malachite green.

Publisher Summary This chapter focuses on Cyniclomyces genus and its constituent species. The cells of this genus are long-ovoidal to cylindrical. In liquid media they occur in branched chains and in solid media, they are mainly singles or pairs. Vegetative reproduction occurs through budding at the poles or on broad shoulders, and in liquid media a layer of sediment is formed. Ascospores in this genus are ovoidal to cylindrical, one to four per ascus. No conjugation of cells occur prior to sporulation, and upon germination, an exosporium is evident. Fermentation of sugars is weak and growth occurs only between 30 and 40°C. Amino acids, B-vitamins, and an increased level of CO2 in the gas atmosphere are required for growth. The only member species of this genus is Cyniclomyces guttulatus. When a plate of yeast autolyzate-Proteose-peptone-glucose agar (pH4.5) is inoculated with cells of C. guttulatus, smooth, semiglossy colonies appear after 24 hours, provided the plates are incubated in an atmosphere high in CO2 content. No conjugation immediately precedes ascospore formation and the vegetative cells are presumed to be diploid. Asci contain one to four (rarely more) ovoidal to cylindrical ascospores, which lie free in the ascus. Thisarrangement is quite different from the tightly fitting spores in asci of species of Saccharomyces.

Forty-one isolates of Botrytis cinerea Fr. collected from 34 nurseries (mainly from tomato and lettuce crops) and 72 isolates from a tomato experiment were examined for tolerance in vitro to benomyl. Six of the nursery isolates grew in the presence of 500 ppm benomyl and five of these came from lettuce crops. Almost all of the remaining 35 isolates were completely inhibited by 0·5 ppm. None of the 72 isolates from the tomato experiment, which included various benomyl treatments, was as tolerant although several grew at 12·5 ppm benomyl. Three benomyl-tolerant isolates were tested and found to be similarly tolerant to the related compounds thiophanate-methyl, thiabendazole and BAS 3460F. Benomyl tolerance was not lost after ten successive subcultures on agar in the absence of benomyl.

A procedure was developed to remove trophectoderm cells from day-8 blastocysts of the marmoset monkey. Using micromanipulative techniques, a tear was made in the zona pellucida opposite the inner cell mass which facilitated the controlled herniation of trophectoderm cells as the blastocysts developed in vitro. After 24 h (day-9 blastocysts) and 48 h (day-10 blastocysts) of culture approximately 20% and approximately 50% respectively of the blastocyst had herniated. The herniated trophectoderm was cut off by freehand and the biopsied blastocysts transferred to recipients. Normal offspring were born but pregnancies could be established from day-10 blastocysts only if the recipients were treated with human chorionic gonadotrophin during early pregnancy. One pregnancy was established after the transfer of three frozen biopsied day-10 blastocysts. Biopsies of 30-50 cells from day-10 blastocysts could be readily grown in vitro as trophoblast vesicles to in excess of 1000 cells but biopsies of less than 20 cells from day-9 blastocysts formed a monolayer of binucleated and multinucleated cells with limited cell replication. Assuming human trophectoderm cells have a similar capacity to the marmoset to grow in vitro, the application of this technique to human blastocysts would provide sufficient cells on which the preimplantation diagnosis of a genetic disorder could be made.

Terremutin, a new metabolite isolated from cultures of an Aspergillus terreus mutant, has been characterized as 4,5-dihydroxy-3-methyl-7-oxabicyclo[4.1.0]hept-3-en-2-one. The complete stereochemistry is presented.

Thalli of Marchantia polymorpha were irradiated with Co60 gamma rays at exposures up to 55 kR and scored for survival after 4 weeks of growth. The reproductive integrity of the two apical cells of the thalli was inhibited by exposures lower than those required for complete lethality of the thalli. The nuclei of these apical cells are approximately 9·4 times larger than those in the vegetative cells adjacent to the proximal end of the rhizoids (116·6 ±13·0 μ3 vs. 12·4 ±1·1 μ3). At the 100 per cent lethal exposure the energy absorbed by the interphase chromosomes of the vegetative cells of the thallus is within the 95 per cent confidence limits as previously predicted for chromosomes of similar size in higher plants. The radiosensitivity of the thallus, however, is different from that of the gemma when sensitivity is based on an energy absorption basis: the thallus is approximately 4·3 times more sensitive than the gemmae.

Eighteen patients with reversible airway disease judged by an improvement in maximum voluntary ventilation (MVV) of 30 percent or more six months after entry into a comprehensive, standardized care program for chronic airway obstruction were compared to similar individuals not equally improved. Patients with chronic airway obstruction with a wheezing type onset who also demonstrated recurrent bouts of wheezing or congestion and those with a relatively short duration of disease with a small but definite response to inhaled bronchodilator are candidates for a trial of corticosteroid therapy guided by physiologic tests to measure objective functional improvement. The 18 improved patients had a statistically significant improvement in vital capacity, maximum voluntary ventilation, resting pO2, resting oxygen saturation, and a marked improvement in exercise tolerance.

The effect of commercial processing (blanching and/or roasting) on total vitamin B6 retention in processed almonds (Prunus amygdalus, Batsch) was investigated. The yeasts Saccharomyces uvarum and Kloeckera apiculata were used as comparative test organisms for the assay. Different values for vitamin B6 content were obtained from the same samples by using different test organisms. The use of K. apiculata resulted in significantly higher values for total vitamin B6 content than those obtained using S. uvarum. These differences in vitamin B6 values could be attributed to the inherent differences in the nutritional requirements of the two yeasts to vitamin B6 and to the differences in the natural responses of the two organisms towards the different forms of vitamin B6. The overall results obtained indicate that both blanching and roasting processes resulted in some loss of vitamin B6 content. Roasted almonds retained approximately 76% (with S. uvarum) and 74% (with K. apiculata) of their initial vitamin B6 content. Similarly, blanched almonds retained 88% (with S. uvarum) and 87% (with K. apiculata) of their initial vitamin B6 content. Almonds that were blanched and then roasted retained approximately 78% (with S. uvarum) and 73% (with K. apiculata) of their initial vitamin B6 content. The total vitamin B6 content of the natural unprocessed (raw) almonds was 0.83 μg/g (with S. uvarum) and 1.74 μg/g (with K. apiculata) on a dry-weight basis. These values were used as the basis for calculating the percent retention in the processed almond samples.

A spectrophotometric and a radioacti ve-1 abel The exposure system was a glass technique were used to assess acoustically induced iodine release. test tube insonated transversely with a 1 MHz ultrasound source. The medium used for the assays was 5.0 mM sodium iodide in the presence of carbon tetrachloride. In one assay 1311 was quantitated by liquid scintillation counting and in the other the optical density of the solution was monitored at 520 nm. For both techniques there was a dose dependent re1 ationship between the percentage of iodine released and the u ltrasound intensity (1

Commercial production of Shiitake, Lentinus edodes , in the United States in 1985 was estimated at 400, 000 kg, most destined for the fresh market. The technology for indoor production in supplemented sawdust media currently employed by the U.S. growers is primarily adapted from that developed in Japan, Taiwan and mainland China, and significant changes do not appear warranted at the present time.

Yeasts were isolated from the crop and/or gut contents of foraging honey bees which were captured upon their return to the hive near Davis, California during a yearlong study. One hundred eighty-one yeasts were isolated from 194 pollen-collecting (PC) bees while 381 yeasts were isolated from 209 nectar-collectors (NC). Ascosporogenous yeasts (27%) included species of Debaryomyces (2 isolates), Hanseniaspora (36), Kluyveromyces (13), Metschnikowia (79), Pichia (20) and Saccharomyces (2). Asporogenous isolates (73%) were represented by Candida (156 isolates), Cryptococcus (60), Kloeckera (46), Rhodotorula (63), Sporobolomyces (1), Torulopsis (75) and Trichosporon (2). No sporogenous basidiomycetous yeasts were identified. Numbers of yeasts isolated varied seasonally for both PC and NC bees, increasing in March-April, September-October and in December for PC bees. Maximum numbers for NC bees was July-September which coincided with minimum isolates from PC bees (June-August). Isolation of sporogenous and asporogenous yeasts also varied with time of year and/or type of bee activity. KEYWORDS Yeasts;, honey bees;, yeast ecology;, insect ecology.

trasonically-ind uced cell terms of classical radiation A theoretical expression tion of intact c ell s remaining after a given period of sonication in a rotating cul ture tube to the number of non-trapped bubbles, a, which a cell must encounter in order to be lysed is obtained. The expression is compared to experimental results in order to determine the actual value of a. It is found that L equals one (1). The concentration of non-trapped bubbles which is responsible f r th observed cell lysis is estimated at 25-50x109 mechanism for non-trapped-bubble-induced cell lysis is proposed. A