Search Results - (Author, Cooperation:H. J. Williams)

2018-04-17

American Physical Society (APS)

0031-9007

1079-7114

Physics

Atomic, Molecular, and Optical Physics

2018-01-12

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

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Genetics, Microbiology

2013-04-26

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Aerobiosis ; Archaea/metabolism ; Bacteria/*metabolism ; Bacterial Proteins/chemistry/metabolism ; *Biocatalysis ; Deoxyadenosines/chemistry/metabolism ; Electron Spin Resonance Spectroscopy ; Glycine/chemistry/metabolism ; Hydrogen/metabolism ; Lyases/chemistry/metabolism ; Mass Spectrometry ; Methane/*biosynthesis/chemistry/metabolism ; Methionine/metabolism ; Mutant Proteins/chemistry/genetics/metabolism ; Pentosephosphates/chemistry/metabolism ; S-Adenosylmethionine/metabolism

2014-01-28

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Child Development Disorders, Pervasive/genetics ; Cytoskeletal Proteins/metabolism ; Exome/genetics ; Fragile X Mental Retardation Protein/metabolism ; Humans ; Intellectual Disability/genetics ; *Models, Neurological ; Mutation/*genetics ; Mutation Rate ; Nerve Net/*metabolism/physiopathology ; Nerve Tissue Proteins/metabolism ; Neural Pathways/*metabolism/physiopathology ; Phenotype ; RNA, Messenger/genetics/metabolism ; Receptors, N-Methyl-D-Aspartate/metabolism ; Schizophrenia/*genetics/metabolism/*physiopathology ; Substrate Specificity ; Synapses/*metabolism

2011-11-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Escherichia coli/enzymology/genetics/*metabolism ; Escherichia coli Proteins/chemistry/genetics ; Lyases/genetics/metabolism ; Organophosphonates/*chemistry/*metabolism ; Phosphates/*chemistry/*metabolism

2011-11-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1570-7458

Hymenoptera ; Ichneumonidae ; Campoletis sonorensis ; parasitoid ; host microhabitat ; synomones ; wind tunnel ; experience

Springer Online Journal Archives 1860-2000

Biology

Abstract The host microhabitat location behavior of females of the generalist parasitoid Campoletis sonorensis (Cameron) (Hymenoptera: Ichneumonidae) was studied in a wind tunnel. Visual cues associated with the host plant cotton, Gossypium hirsutum L., were important and significantly more parasitoids completed flights to a damaged 4-leaf cotton plant bearing a Heliothis virescens (F.) (Lepidoptera: Noctuidae) larva and frass than to a similarly damaged single leaf with frass and a larva. This difference in completed flights was not due to differences in amounts of volatiles released by the two stimuli. Both naive and experienced parasitoids responded differently to an undamaged cotton leaf, a mechanially damaged leaf, a naturally damaged leaf with the host removed and a naturally damaged leaf with a host larva. Parasitoids completed significantly fewer flights to the undamaged sources of volatiles than to damaged sources of volatiles. Experienced females responded strongly to all types of damage. The number of flights completed by naive females to the three types of damage differed but not significantly and was less than the number completed by experienced females. Components of the preflight experience were varied to determine which factors were responsible for the higher response of experienced females to the host/plant complex. Oviposition was the most important component of this experience. Contact with host frass or plant damage followed by oviposition did not increase the response over that exhibited by females allowed oviposition only. When frass or damaged plant material were contacted without subsequent oviposition, females completed fewer flights than naive females.

Electronic Resource

1570-7458

Campoletis sonorensis ; parasitoid ; Hymenoptera ; Ichneumonidae ; Heliothis virescens ; cotton ; potential host community location ; host location

Springer Online Journal Archives 1860-2000

Biology

Résumé Les comportements d'évaluation de l'effectif d'hôtes potentiels et de la position des hôtes par C. sonorensis (Hyméno.: Iccheumonidae) ont été quantifiés pour déterminer les séquences significatives des événements comportementaux. La localisation de la colonie potentielle d'hôtes est apparue comme une séquence régulière des événements comportementaux. Une fois que le parasitoïde a localisé une colonie potentielle, on a constaté que la recherche au hasard des hôtes se poursuit jusqu'à ce qu'il ait la démonstration qu'il s'agit d'une plante attaquée. La localisation par le parasitoïde d'un hôte certain a consitué une autre séquence régulière des événements comportementaux terminant la localisation de l'hôte. L'influence de pieds de coton intacts, de pieds abîmés mécaniquement et de pieds occupés par des chenilles du 3ème stade de l'hôte et de plantes dont les chenilles ont été retirées juste avant l'expérience a été déterminée en modifiant la composition du complexe hôte/plante. Des femelles naïves de C. sonorensis ont montré en présence de pieds de coton intacts apparemment toutes les séquences comportementales de vol impliquées dans la localisation d'une colonie potentielle d'hôtes. Une fois que le parasitoïde a atteint la colonie potentielle d'hôtes, la présence de dégâts de l'hôte n'a pas modifié le temps passé sur la plante, mais a modifié le temps consacré à la prospection.

Abstract Wind tunnel flight behavior of inexperienced female Campoletis sonorensis (Cameron) (Hymenoptera; Ichneumonidae) in response to its larval host Heliothis virescens (F.) (Lepidoptera: Noctuidae) feeding on the host plant cotton (Gossypium hirsutum L.) is described. The flight behavioral sequence was determined by quantification of frequencies of observed behaviors and probabilities of first-order behavioral transitions. Comparison of inexperienced C. sonorensis flights to undamaged and damaged cotton indicated that stimuli from undamaged plants alone are adequate to elicit the complete flight behavioral sequence observed in response to H. virescens feeding on cotton. Parasitoid foraging behavior was also analyzed after landing on the stimulus. This behavior appeared to be random in its initial stages, but became sequential after location of evidence of a host. Analysis of foraging on undamaged and 3 treatments of damaged cotton resulted in the determination that parasitoids tend to remain on damaged plants longer than undamaged plants although no significant difference was detected. C. sonorensis spent a greater percentage of their time foraging on host damaged plants than on undamaged plants.

Electronic Resource

1570-7458

parasitoid ; Campoletis sonorensis ; Hymenoptera ; Ichneumonidae ; cotton ; Gossypium hirsutum ; habitat location ; flight ; wind tunnel

Springer Online Journal Archives 1860-2000

Biology

Résumé Campoletis sonorensis (Cameron) est attiré par diverses plantes et manifeste une forte attraction pour le coton (Gossypium hirsutum L.). Le vol étant certainement le moyen utilisé lors de la détection d'habitats chez ce parasitoïde, un test biologique en tunnel de vol a été développé pour évaluer ces réponses de détection d'habitat chez des femelles deC. sonorensis en présence de coton. Des essais comparatifs ont montré l'existence de vols orientés vers le coton mais non vers des sources inertes, et, sur le coton, les vols ont été plus nombreux vers les plantes avec glandes que vers celles sans glande. Ces résultats sont apparus consistents sur trois paires de lignées avec et sans glandes. Le coton dépourvu de glande ne possède pas, ou seulement en faibles quantités, les terpènes volatils présent en quantités abondantes dans le coton avec glandes. Ce fait peut donc être reponsable des différences de comportement de vol observé envers les deux types de coton. Lors d'essais comparatifs, un nombre de parasitoïdes significativement supérieur a volé vers le cultivarG. hirsutum L. Tamcot CAMD-E par rapport aux espèces diploîdesG. arboreum etG. anomalum. Les cotons diploîdes manquent de certains terpènes volatils démontré attractifs pourC. sonorensis et ces différences peuvent expliquer les résultats observés. Des changements significatifs de réponse des parasitoïdes peuvent donc naître des variations de composition chimiques résultant de pression de sélection naturelles ou artificielles.

Abstract The behavior of parasitoidCampoletis sonorensis females to cotton (Gossypium hirsutum) leaf odor sources was examined in a wind tunnel bioassay. Parasitoids exhibited oriented flights to cotton but not to inert sources, and flew in significantly greater proportion to glanded cotton when compared to glandless cotton in choice tests. A relative lack of volatile terpenes in glandless cotton may account for response differences. Significantly more parasitoids flew to theG. hirsutum cultivar Tamcot CAMD-E than to the diploid cottonsG. arboreum andG. anomalum in choice tests. Differences in volatile chemical composition of the diploid cottons may account for these results. The data are discussed with regard to host habitat location.

Electronic Resource

1570-7458

Campoletis sonorensis ; Microplitis croceipes ; Heliothis virescens ; Gossypium hirsutum ; wind tunnel ; bioassay ; Hymenoptera ; parasitoid

Springer Online Journal Archives 1860-2000

Biology

Résumé Le comportement de vol de M. croceipes Cres. (Hym. Braconidae) et de C. sonorensis Cam. (Hym. Icheumonidae) a été étudié en olfactométrie dans un tunnel à vent. Les femelles des deux espèces, et non les mâles, ont un vol orienté par l'odeur des feuilles fraîches de coton (Gossypium hirsutum L.). La fréquence d'envol est liée aux changements de vitesse du vent, aux variations d'émissions, par le cotonnier, des substances volatiles, en fonction de la vitesse du vent, ou aux deux. La fréquence d'envol à vitesse de vent constante dépend de l'éclairage. La fréquence d'envol de C. sonorensis augmente avec des intensités lumineuses relativement fortes et diminue avec des intensités relativement faibles. L'inverse est observé avec M. croceipes. Le vent chargé d'odeurs de larves ou d'extréments d'Heliothis virescens F., attire M. croceipes et non C. sonorensis. Nous suggérons une éventuelle interaction des odeurs portées par le vent et provenant de l'habitat et de l'hôte.

Abstract Flight behavior of parasitoids Microsplitis croceipes Cresson (Braconidae) and Campoletis sonorensis (Cameron) (Ichneumonidae) was examined in a wind tunnel. Both species exhibited odor directed, oriented flights to cotton, although flight frequency was related to variation in wind velocity or differential cotton volatile emission with changes in wind velocity, or both. Flight frequency at constant wind velocity was affected by illumination. Microplitis croceipes was attracted to the wind borne odor of Heliothis virescens (F.) frass and larvae, whereas C. sonorensis was not. Possible interaction of the wind borne odors from the habitat and host is suggested for parasitoids.

Electronic Resource

1432-1998

Springer Online Journal Archives 1860-2000

Medicine

Abstract Gallstone formation complicating cardiac valve replacement has been amply documented in adults. Two children who developed gallstones shortly after cardiac valve surgery are reported.

Electronic Resource

1420-9098

Springer Online Journal Archives 1860-2000

Biology

Resume Nous décrivons dans cet article l'ultrastructure et la fonction de l'intestin postérieur chez la “fourmi de feu”Solenopsis invicta Buren. La base de l'intestin postérieur est fermée et insérée (par le “dôme”) dans la paroi postérieure de l'intestin moyen; elle est composée de cellules basales provenant à la fois des quatres tubes malpighiens et de l'intestin postérieur (ileo-colon). L'ileo-colon débouche, grâce à une valvule rectale, dans le rectum, et y déverse de l'acide urique (excrétion blanchâtre) sécrété par les tubes malipighiens. L'épithélium rectal à paroi mince possède trois papilles rectales composées de grosses cellules cuboïdes. Les matériaux excrétés par la larve consistent en deux éléments: un précipité blanc composé d'acide urique et un liquide clair composé d'eau et de sels. Les observations ultrastructurales suggèrent que les papilles rectales et les tubes malipighiens sécrètent le liquide clair à partir de l'hémolymphe; les résultats d'expériences menées sur les excréments indiquent par ailleurs que les excrétions larvaires ne sont pas ingérées par les autres membres de la colonie, à l'exception des adultes qui mangent du liquide clair en cas de déficit en eau. Les adultes transportent les matériaux excrétés hors du nid.

Summary The ultrastructure and excretions of the hindgut of larvæ of the imported fire ant,Solenopsis invicta Buren, is described. The anterior or base of the hindgut is closed and rooted (via the “dome”) in the posterior wall of the midgut, and is composed of basal cells of both the malpighian tubules and the small intestine (ileo-colon). The ileo-colon opens via a rectal valve into the rectum and transfers uric acid (white excretion) secreted by the malpighian tubules, into the rectum. The thin walled rectal epithelium has three rectal pads composed of large, cuboidal cells. The excretory product of larvæ consists of 2 components, a white precipitate composed of uric acid and a clear liquid consisting of water and salts. Ultrastructural and observational studies suggest that the rectal pads and malpighian tubules secrete the clear fluid from the hemolymph. Results of experiments with the waste products indicate that larval excretions are not ingested by other members of the colony except adults which under water stress do consume some of the clear liquid. The adults do participate in the removal of the excretory products from the brood chamber.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Z,Z,Z-Allofarnesene (2Z, 4Z, 6Z)-2,6,10-trimethyl-2, 4, 6, 10-dodecatetraene) was identified as the trail pheromone of the red imported fire ant by comparing chromatographic and spectral properties of the pheromone obtained from ant Dufour's glands with those of synthetic compounds.

Electronic Resource

1573-1561

Bracon ; Ephestia ; Lepidoptera ; Pyralidae ; Hymenoptera ; Braconidae ; kairomone ; host selection ; parasitoid ; foraging ; ketones ; 2-acylcyclohexane-1,3-diones

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract 2-Acylcyclohexane-1,3-diones produced in the mandibular glands ofEphestia kuehniella Zeller (Lepidoptera: Pyralidae) fifth instars acted as arrestment and host-trail following kairomones for the parasitoid,Bracon hebetor (Say) (Hymenoptera: Braconidae). The behavioral response of the parasitoids to the kairomone varied with kairomone concentration and distribution. However, only small differences in activity were noted for the different mandibular gland components.B. hebetor females that encountered filter paper patches impregnated with the kairomone exhibited antennation and probing behavior. Females followed trails formed with 2-[(Z,E)12,14-hexadecadienoyl]cyclohexane-1,3-dione in the same manner exhibited with host-made trails. At concentrations of 1.0 μg/mm and above, trail following was interrupted by frequent probing.

Electronic Resource

1434-9949

Controlled Trials ; Study Design ; Remission-Inducing Therapy

Springer Online Journal Archives 1860-2000

Medicine

Summary Clinical trials with slow-acting or disease-modifying drugs in rheumatoid arthritis are difficult to design and execute. Such trials are expensive and require long periods of observation. However, there is no acceptable alternative to the properly designed and completed controlled clinical trial. Broad principles for the design of such trials and the basic elements of the study design are outlined and discussed.

Electronic Resource

1573-1561

Campoletis sonorensis ; parasitoid ; Hymenoptera ; Ichneumonidae ; cotton ; Gossypium hirsutum ; host habitat location ; green leaf chemical ; monoterpene ; sesquiterpene ; electroantennogram ; olfaction ; volatile

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Combined gas chromatography-electroantennogram (GC-EAG) recording ofCampoletis sonorensis (Cameron) responses to cotton plant volatile chemicals was performed.C. sonorensis antennal olfactory receptors respond differentially to green leaf, mono-, and sesquiterpene chemicals that have been identified previously in cotton. EAG depolarizations to green leaf chemicals were greater than to terpenes.

Electronic Resource

1573-1561

Xylocopa micans ; Hymenoptera ; Anthophoridae ; mesosomal glands ; mandibular glands ; hydrocarbons ; fatty acid esters ; territoriality ; mating system

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Males ofXylocopa micans employ two mating systems in south-central Texas. They defend territories around flowering wisteria and redbud in March and April, and they maintain nonresource-based or landmark territories in July and August. Mandibular and mesosomal gland contents (analyzed by GC-MS) are different in bees employing the two mating systems. Mandibular glands contain only straight-chain hydrocarbons in bees defending floral resources, but include ethyl oleate in bees defending landmark territories. Mesosomal glands contain saturated, mono- and diunsaturated straight-chain hydrocarbons and methyl and ethyl esters of long-chain fatty acids. The major ethyl ester, ethyl oleate, comprises only 1.1% of mesosomal gland contents in bees defending floral resources but comprises 39.7% of gland content of bees defending landmark territories. These findings are discussed relative to the proposed sex pheromone function ofXylocopa gland secretions.

Electronic Resource

1573-1561

Trissolcus basalis ; Nezara viridula ; Hymenoptera ; Scelionidae ; Heteroptera ; Pentatomidae ; kairomone ; parasitoid ; identification ; defensive glands ; host location ; (E)-2-decenal

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract A short-chain α,β-unsaturated aldehyde, (E)-2-decenal, present in the defensive metathoracic gland ofNezara viridula (L.) (Heteroptera: Pentatomidae), stimulates a behavioral response in the egg parasitoidTrissolcus basalis (Woll.) (Hymenoptera: Scelionidae). Preliminary studies showed thatT. basalis are attracted to an area containing adultN. viridula, but we also found that femaleT. basalis would examine and probe glass beads coated with an acetone extract of the metathoracic gland from males or females. Using this bioassay, the kairomone was isolated by bioassay directed by preparative gas chromatography and identified by NMR and mass spectrometry as (E)-2-decenal. The biological activity of the identified aldehyde was compared with analogs to determine specificity. An unstable Z isomer was found to be more active but not present in detectable or behaviorly relevant levels in the host, based on the bell-shaped dose-response curve of the two isomers. An investigation was also designed to determine if theE isomer was also responsible for the egg recognition kairomone activity previously reported. However, no 2-decenal isomers were detected in host egg extracts and the chemical characteristics of the 2-decenal isomers differ from the unidentified egg recognition kairomone. The role of the (E)-2-decenal in attracting femaleT. basalts toN. viridula was demonstrated in a Y-tube olfactometer; this alk-2-enal appears to act as a long-range kairomone orientingT. basalis toNezara populations.

Electronic Resource

1573-1561

Parasitoid ; Hymenoptera ; Ichneumonidae ; Campoletis sonorensis ; synomone ; sesquiterpene ; α-humulene ; γ-bisabolene ; β-caryophyllene oxide ; spathulenol ; gossonorol ; β-bisabolol

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract In laboratory bioassays, the parasitoidCampoletis sonorensis was attracted to the following sesquiterpenes isolated from cotton essential oil: α-humulene, γ-bisabolene, β-caryophyllene oxide, spathulenol, β-bisabolol, and a new, naturally occurring bisabolene-related alcohol, (2-p-tolyl-6-methylhept-5-en-2-ol) which we name gossonorol. This is the first report of spathulenol in cotton. β-Caryophyllene, a major component of cotton, was not attractive to the parasitoids. The response of the parasitoids to these compounds and the possibility of augmenting parasitoid activity in the field by manipulating plant secondary metabolites is discussed.

Electronic Resource

1573-1561

Pheromone ; Rhyzopertha dominica ; lesser grain borer ; Coleoptera ; Bostrichidae ; unsaturated ester ; dominicalure ; 1-methylbutyl (E)-2-methyl-2-pentenoate ; 1-methylbutyl (E)-2,4-dimethyl-2-pentenoate

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Volatiles from lesser grain borers,Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), were collected on Porapak Q, and those from the male beetles were shown to contain two compounds, that were attractive individually and in combination to both sexes. These compounds were identified as (S)-(+)-1-methylbutyl (E)-2-methyl-2-pentenoate and (S)-(+)-1-methylbutyl (E)-2,4-dimethyl-2-pentenoate by spectrometry and comparison with synthesized compounds. The two compounds have been assigned the trivial names dominicalure 1 and dominicalure 2, respectively. Synthesized samples of these compounds, individually and in combination, were effective in trapping both sexes in field studies.

Electronic Resource