Search Results - (Author, Cooperation:T. J. Smith)

2013-08-24

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Animals, Domestic/*microbiology ; Humans ; Meat/*microbiology ; Methicillin-Resistant Staphylococcus aureus/*isolation & purification ; Staphylococcal Infections/*transmission/*veterinary ; Zoonoses/*microbiology/*transmission

2014-01-11

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Anti-Bacterial Agents/*adverse effects ; Antibiotic Prophylaxis/*adverse effects/*veterinary ; *Drug Resistance, Bacterial ; *Guidelines as Topic ; Humans ; *Legislation, Veterinary

2018-06-05

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2018-04-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

1089-7550

AIP Digital Archive

Physics

Numerical calculations of synchrotron radiation emitted from the modified betatron accelerator show that, for relativistic electron energies up to approximately 2 MeV, the single-particle intensity spectrum is characterized by a peak at the Doppler-shifted cyclotron frequency associated with the applied toroidal field. As the electron energy is increased above a few MeV, the calculated spectrum becomes comparable to that of an electron in purely circular motion. Measurements of the radiation using fixed-frequency heterodyne receivers indicate that the polarization, amplitude, and the temporal evolution of radiated power during the first few hundred microseconds of acceleration are in good agreement with the predicted single-particle spectrum. These observations have been used to confirm the energy evolution and provide information about the magnitude of the transverse velocity of the beam electrons. Late-time signal decay suggests that electrons are moving off the minor axis in a manner that is consistent with the excitation of the electron-cyclotron resonance.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

This article investigates a new approach to the optical generation of large-amplitude coherent molecular vibrations in condensed media. On the basis of analytical results using pulse propagators in the classical Franck approximation, we are led to investigate the efficacy of driving vibrational motion in the electronic ground state by impulsive stimulated Raman scattering with a timed sequence of electronically preresonant femtosecond laser pulses. Numerically exact computations are performed on a model system of dilute molecular Iodine in a low-temperature host crystal. Vibrational relaxation is incorporated via Redfield theory. The results indicate that under a variety of conditions, chemically significant (greater than 0.1 A(ring)) displacements can be produced in a Raman active mode with a fair measure of control over wave packet spreading, and without substantial population loss due to electronic absorption. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The nonlinear effects of ultrashort phase-locked electronically resonant pulse pairs on the ground state nuclear motion are investigated theoretically. The pulse-pair propagator, momentum impulse, and displacement are determined in the weak field limit for pulse pairs separated by a time delay short on a nuclear time scale. Possible application to large amplitude vibrational excitation of the 104 cm−1 mode of α-perylene is considered and comparisons are made to other Raman excitation methods.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] SIR - A recent letter (Nature 2 February, p.408) drew attention to page charges in journals and suggested a possible credit system for referees. However, according to an advertising circular recently received by me, at least one new journal (Engineering Computations) is adopting a "rigorous, ...

Electronic Resource

1570-7458

mites ; Halotydeus destructor ; resistance ; antixenosis ; feeding ; toughness ; Trifolium subterraneum ; Acarina ; Penthaleidae

Springer Online Journal Archives 1860-2000

Biology

Abstract The short-term response of redlegged earth mite, Halotydeus destructor (Tucker) (Acarina: Penthaleidae) to cotyledons of different varieties of subterranean clover (Trifolium subterraneum subsp. subterraneum L.) was assessed by means of paired choice tests, and no-choice tests. H. destructor had lower numbers and fed less on detached cotyledons of resistant than susceptible varieties, yielding a correlation between the numbers of mites and feeding damage to the cotyledons during a three hour test period. For a number of resistant and susceptible varieties, there was a negative correlation between cotyledon deterrence in the three hour choice test and feeding damage to seedling after a two week period. Since the response of the mites to different subclover varieties occurred within three hours, it is concluded that the resistance is based on antixenosis. No evidence was obtained for antifeedant activity in organic solvent extracts from the variety DGI007 (resistant) in comparison with those from the variety Dalkeith (susceptible). Water soluble compounds from DGI007 cotyledons were preferred by mites, in feeding tests in terms of numbers, over those from Dalkeith (susceptible). Squeezed sap from the cotyledons of both varieties showed the same effects on mites as 5% glucose and were more phagostimulatory than water extracts. Mechanically damaged cotyledons of Dalkeith and DGI007 attracted more mites than the undamaged counterparts. The toughness of cotyledons in 17 varieties of T. subterraneum subsp. subterraneum was measured with a manual penetrometer. Results showed a negative correlation between toughness values and mite feeding damage scores (r2=0.752) for all varieties except S3615D (resistant). This implies a likely involvement of epidermal toughness as a contributor in the antixenotic resistance of these varieties. Other mechanisms may be involved in the resistance of S3615D.

Electronic Resource

1570-7458

Springer Online Journal Archives 1860-2000

Biology

Résumé Des études en laboratoire sur le comportement alimentaire des larves de dernier âge de Sericesthis nigrolineata, ont montré que celles-ci sont moins actives en présence de racines mortes que dans un sol nu et se déplacent encore moins dans un sol avec présence de racines vivantes. Les larves ingèrent de façon sélective la matière organique du sol même sans plantes, mais la présence de racines vivantes a pour effet d'accroître la quantité de matière organique trouvée dans l'intestin des larves, d'accroître également la vitesse d'ingestion et la croissance larvaire. L'alimentation et la croissance des larves ne sont pas dépendantes de la quantité de matière organique contenue dans le sol, et il est suggéré que les larves se nourrissent préférentiellement sur les racines vivantes.

Abstract In a laboratory study of feeding behaviour, final (third)-instar larvae of Sericesthis nigrolineata moved less in soil in the presence of dead roots than in soil alone, and less in soil in the presence of living roots than with dead roots. Larvae selectively ingested organic matter from soil with no plants but the presence of living roots produced increases in the amount of organic matter in the gut of larvae, the amount of organic matter removed from the food in the gut, the rate of ingestion and the rate of larval growth. The feeding and growth responses of larvae were not correlated with the quantity of organic matter present in the soil. It is suggested that the larvae preferentially select and feed on living roots.

Electronic Resource

1570-7458

Springer Online Journal Archives 1860-2000

Biology

Résumé La consommation des larves de troisième stade de Sericesthis nigrolineata a été mesurée sous des conditions de température constante. Les larves ont été placées dans un milieu de tourbe humide et nourries de carottes. La consommation augmente de façon exponentielle avec la température entre 4° et 30°; la partie inférieure de la courbe résulte du fait que les larves cessent de se nourrir, mais au haut de la courbe les larves sont tuées par les hautes températures. Les taux relatifs de croissance larvaire atteignent leur apogée à 17.5° et la croissance est nulle à 5° et 32°; le coefficient d'utilisation digestive est le plus élevé à 14° avec une valeur maximum de 11%. Les larves de troisième stade ont perdu du poids mais ont continué à se nourrir sauf pendant une courte période avant de se transformer en prépupes. Le développement larvaire dépend de la température et il n'y a aucune évidence de diapause pour les larves. En supposant qu'il n'y ait aucun changement dans le taux de croissance, on estime qu'une larve consomme 4237–5085 mg de carotte (poids humide) au cours de sa vie et la proportion de nourriture prise par les larves de premier, second et troisième stade augmente régulièrement d'un facteur × 3,5 à peu près entre chaque stade. Les données de consommation estimées pour les larves de S. nigrolineata, en se servant de carottes comme source de nourriture, représentent la meilleure estimation de ration alimentaire dont on dispose, en attendant que la consommation de racines d'herbe puisse être mesurée directement.

Abstract Consumption of carrot by third-instar larvae of Sericesthis nigrolineata was measured under conditions of constant temperature. Consumption increased curvilinearly with increasing temperature between 4° and 30°. Larvae stopped feeding at the lower threshold, but at the upper threshold larval mortality prevented further feeding. Larval relative growth rate peaked at 17.5°, with zero growth at 5° and 32°, and the proportion of food converted to growth was greatest at 14° with a value of 11%. Late third-instar larvae lost weight but continued feeding, except for a short non-feeding period, before entering the prepupal stage. There was no evidence for a diapause by mature larvae.

Electronic Resource

1570-7458

Musca vetustissima ; Onthophagus binodis ; Scarabaeinae ; Muscidae ; spring ; summer ; interspecific ; intraspecific ; densities

Springer Online Journal Archives 1860-2000

Biology

Résumé Des oeufs de mouches de brousse (Musca vetustissima) et des bousiers adultes (Onthophagus binodis) ont été dépos'es à différentes densités sur de la bouse de printemps, riche en nutriments, ou d'été, paure, au laboratoire à 25°C. Les compétitions intra- et interspécifiques ont été plus intenses pour les mouches sur la bouse d/été, et pour les bousiers sur la bouse de printemps. Dans les bouses d'été, la taille des mouches et leur survie ont été influencées à la fois par la densité des bousiers et par celle des mouches. Les mouches élevées sur bouses d'été étaient plus petites, et une corrélation entre la taille et le taux de survie a été observée pour des mouches dont la largeur de la tête était inférieure à environ 2,00 mm. La mortalité était due probablement en grande partie à la mort des larves. Les bousiers n'ont construit que très peu de boules d'excrêments et déchiquetaient la bouse, surtout quand leur densité était élevée. Dans la bouse de printemps, la production de boules d'excrêment a été réduite tant par les densités de bousiers que de celles de mouches. La survie des mouches a été influencée par la densité de bousiers, moins cependent que dans les bouses d'été, mais pas par celle des mouches. La mortalité était due probablement à la mort des oeufs.

Abstract A range of densities of bush fly (Musca vetustissima) eggs and dung beetle (Onthophagus binodis) adults were placed on either nutritious spring or poor summer dung in the laboratory at 25°C. Intra- and interspecific competition were greater for flies in summer dung than in spring dung, and intra-and interspecific competition were greater for dung beetles in spring dung than in summer dung. In summer dung fly size and survival were influenced by both beetle and fly densities. Flies in summer dung were smaller, and below a headwidth of about 2.0 mm there was a correlation between size and survival. Mortality was probably due largely to death of larvae. Also beetles produced very few brood balls, and shredded this dung, particularly at high densities. In spring dung, beetle brood ball production which was greater was reduced by both beetle and fly densities, and beetles left the pads earlier at high fly densities. Fly survival was influenced by beetle density, but less than in summer dung, and not by fly density. Mortality was probably caused by death of eggs. These data support field observations that dung beetles cause higher fly mortality in summer dung than spring dung.

Electronic Resource

1569-8041

costs ; fee-for-service ; granulocyte colony stimulating factors ; granulocyte macrophage colony stimulating factors ; hematopoietic colony stimulating factors ; HMO

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background/objectives: Financial considerations play an important role in the delivery of medical care in the US. In 1996, revised guidelines from the American Society of Clinical Oncology (ASCO) indicated that granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF) were unlikely to be harmful for older acute myeloid leukemia (AML) patients and suggested that physicians could consider their use in this setting. In 1997, the ASCO health services research committee evaluated whether physician reimbursement was a primary determinant in the decision to use G-CSF and GM-CSF in this clinical situation. Patients and methods: A questionnaire describing clinical scenarios for a 67-year-old man with newly diagnosed de novo AML was mailed to 1500 ASCO members who practiced medical oncology and hematology. Physicians were queried about their preferences for adjunctive CSF use following induction and consolidation chemotherapy. Results: Of 1020 potentially eligible respondents, returned surveys were received from 672. Following induction chemotherapy, support for CSF use was 40%, similar in magnitude for that for non-use of these agents. The most important determinant of support for CSF use was being in a fee-for-service practice (P 〈 0.001). Conclusions: Physicians in the US are mixed in their support for CSFs for older AML patients. Support was high in settings where CSF use was accompanied by financial profit to the physician practice, and support was low otherwise.

Electronic Resource

1570-7458

Fluctuating asymmetry ; avermectin ; Musca vetustissima ; developmental stability

Springer Online Journal Archives 1860-2000

Biology

Résumé La fluctuation de l'asymétrie a été utilisée comme indice de la stabilité du développement pour mettre en évidence l'effet de l'exposition à l'avermectine B1 au cours du développement de M. vetustissima. Les mouches élevées sur bouses de vaches traitées à l'avermectine B1 sont devenues significativement plus asymétriques pour 2 caractères morphométriques (longueurs des veines de l'aile) que celles élevées sur bouses de vaches témoins ou de vaches traitées au Levamisole-HCl, même quand la survie des mouches n'était pas affectée par le traitement. La fluctuation de l'asymétrie s'est avérée un bon critère pour définir des stress pendant le développement, alors que des critères conventionnels comme la survie ne permettent pas de déceler quoi que ce soit.

Abstract Fluctuating asymmetry is used as an indicator of developmental stability to assess the effect of exposure to Avermectin B1 on normal developmental processes in the bush fly, Musca vetustissima Walker (Diptera: Muscidae). Flies breeding in dung from cattle treated with Avermectin B1 were found to be significantly more asymmetric for two morphometric characters (wing vein lengths), than those breeding in dung from either untreated cattle or cattle treated with Levamisole-HCl at times when fly survival was not affected by the treatments. Fluctuating asymmetry is shown to be a valuable means of defining developmental stress in situations where conventional estimates such as survival show no response.

Electronic Resource

1432-1254

Springer Online Journal Archives 1860-2000

Geography

Physics

Zusammenfassung Bronchialasthma bei Studenten der Universität Minnesota wurde bezüglich der Empfindlichkeit gegen Getreidesamen mit Kontrollgruppen untersucht, um den Einfluss der in der Luft befindlichen Pollen durch nahe gelegene Getreidefelder zu finden. Unter verhältnismässig hohen Konzentrationen wurde beobachtet,dass gegen Getreidesamen empfindliche Studenten doppelt so viele Asthmaanfälle hatten, wie die Kontrollgruppe, die keine signifikante Änderung zeigte. Eine Verbindung von Windrichtung und relativ hohen Staubkonzentrationen mit Asthmaanfällen ergab eine Korrelation von höherer Signifikanz in der sensiblen Gruppe. Weitere Zuordnungen zeigten, dass diese Beziehung nur wenig durch Änderungen von Jahreszeit und Temperatur beeinflusst wird. Es wurde auch beobachtet, dass die Relative Feuchte die Empfindlichkeit gegen Pollen bei entsprechend sensibilisierten Studenten beeinflussen kann. In der Kontrollgruppe zeigten Wetterparameter keine Beziehung zum Asthma.

Resume On a étudié les accès d'asthme bronchial provoqués par les polluants de l'atmosphère provenant d'entreprises travaillant les céréales et situées dans le voisinage du l'Université du Minnesota. Pour ce faire,on s'est servi d'étudiants de la dite Université sensibles aux poussières de céréales d'une part et d'un groupe de contrôle d'autre part. Dans des conditions de poussière relativement forte,on a observé que les étudiants sensibles aux poussières de céréales présentaient une fréquence double d'accès d'asthme alors que le groupe de contrôle n'était pas touché de façon significative. En utilisant une conbinaison des facteurs direction du vent et forte poussière d'une part, accès d'asthme d'autre part,on obtient une corrélation plus significative dans le groupe des gens sensibles.Des combinaisons multiples indiquent que cette corrélation n'est que peu influencée par la saison ou des changements de température. On a aussi remarqué que les conditions d'humidité relative peuvent influencer de façon significative la sensibilité effective aux poussières des étudiants du premier groupe. Quant au groupe de contrôle, on n'a pas trouvé de relation entre les accès d'asthme et les paramètres météorologiques.

Abstract Student bronchial asthma at the University of Minnesota was studied in grain sensitive and in control groups to find the influence of air pollutants from nearby grain installations on this problem.Under relatively high dust conditions it was observed that grain sensitive students had a two-fold increase in asthma attacks while the controls showed no significant changes. A combined association of wind direction and relatively high dust conditions with asthma gave a correlation of higher significance in the grain sensitive group. Multiple associations indicated that this relationship is only weakly affected by seasonal and temperature changes. It was also observed that relative humidity conditions may significantly influence the effectiveness of the dust exposure in sensitive students. Weather parameters showed no association with asthma in the control group.

Electronic Resource

1432-0800

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Electronic Resource

1432-0800

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Electronic Resource

1432-0800

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Electronic Resource

1572-9702

Assays ; volatile compounds ; Halotydeus destructor ; mite feeding ; subclover cotyledons ; artificial damage

Springer Online Journal Archives 1860-2000

Biology

Abstract The effects on the redlegged earth mite (Halotydeus destructor) (Acarina: Penthaleidae) of volatile compounds released from artificially damaged cotyledons of subterranean clover (Trifolium subterraneum L.), a host plant, were investigated with different assays. Mites were repelled by the volatile compounds in flask tube and in trimmed cotyledon disc tests. No differences could be shown between different tissue amounts and between resistant and susceptible varieties. When a membrane sachet was used containing either 2-(E)-hexenal, a compound produced by damaged subclover cotyledons, or the total volatile compounds collected from damaged cotyledons of Dalkeith (susceptible) admixed with 1% glucose, mites gathered to low but were deterred by high concentrations of the compounds. Volatile compounds collected from the resistant variety DGI007 were more deterrent than those from the susceptible Dalkeith. Membrane sachets containing 30 p.p.m. of 2-(E)-hexenal and 1% glucose were less preferred than cotyledons of Dalkeith (susceptible) but were not different from DGI007 (resistant). By increasing the glucose concentration to 5%, the membrane sachets with 30 p.p.m. of 2-(E)-hexenal were preferred to cotyledons of either variety. The results indicate that the membrane feeding technique provides a sensitive way of assaying volatile compounds from damaged subclover cotyledons against the mite.

Electronic Resource

1572-9702

redlegged earth mite ; Halotydeus destructor ; cold storage ; low temperature

Springer Online Journal Archives 1860-2000

Biology

Abstract Survival of medium sized nymphal stages of redlegged earth mite Halotydeus destructor (Tucker) (mainly tritonymphs and deutonymphs) stored under low temperature (1.5° C) in sealed plastic boxes remained more than 50% after 12 days of storage, with some mites surviving for up to eight weeks. Adding fresh subclover leaves into the storage box increased the survival rate of mites from 12% to 28%, 19 days after the storage started. Mites stored for two weeks at low temperatures showed feeding activity in a screening experiment similar to mites collected directly from the field. This indicated that cold storage of redlegged earth mite can be used to build up mite numbers for large screening experiments, or to extend the period of availability of mites collected from the field. However, their reproductive ability was greatly reduced after three weeks at low temperature. Thus, care should be taken when using mites for experiments measuring reproduction. The implications of low temperatures for reducing field populations of mites in midwinter are also discussed.

Electronic Resource