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  • 1
    Electronic Resource
    Electronic Resource
    Electron, photon, and ion beams from the relativistic interaction of Petawatt laser pulses with solid targets : The 41st annual meeting of the division of plasma physics of the american physical society (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 2076-2082 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In recent Petawatt laser experiments at Lawrence Livermore National Laboratory, several hundred joules of 1 μm laser light in 0.5–5.0-ps pulses with intensities up to 3×1020 W cm−2 were incident on solid targets and produced a strongly relativistic interaction. The energy content, spectra, and angular patterns of the photon, electron, and ion radiations have all been diagnosed in a number of ways, including several novel (to laser physics) nuclear activation techniques. About 40%–50% of the laser energy is converted to broadly beamed hot electrons. Their beam centroid direction varies from shot to shot, but the resulting bremsstrahlung beam has a consistent width. Extraordinarily luminous ion beams (primarily protons) almost precisely normal to the rear of various targets are seen—up to 3×1013 protons with kTion∼several MeV representing ∼6% of the laser energy. Ion energies up to at least 55 MeV are observed. The ions appear to originate from the rear target surfaces. The edge of the ion beam is very sharp, and collimation increases with ion energy. At the highest energies, a narrow feature appears in the ion spectra, and the apparent size of the emitting spot is smaller than the full back surface area. Any ion emission from the front of the targets is much less than from the rear and is not sharply beamed. The hot electrons generate a Debye sheath with electrostatic fields of order MV per micron, which apparently accelerate the ions. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.874030
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  • 2
    Electronic Resource
    Electronic Resource
    HOST PLANT INFLUENCES ON SEX PHEROMONE BEHAVIOR OF PHYTOPHAGOUS INSECTS1 (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Entomology 42 (1997), S. 371-391 
    Details
    ISSN: 0066-4170
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Notes: Abstract The sexual behavior of phytophagous insects is often integrated in a variety of ways with their host plants. This integration may be manifested as effects or influences of host plants on insect physiology and behavior, including sex pheromone communication, that reflect strategies by insects to optimize mating and reproduction. Certain insects sequester or otherwise acquire host plant compounds and use them as sex pheromones or sex pheromone precursors. Other insects produce or release sex pheromones in response to particular host plant cues. Chemicals from host plants often synergize or otherwise enhance insect responses to sex pheromones. By these means, host plants may be used by insects to regulate or mediate sexual communication. For many species of insects, host plant influences on insect sex pheromone communication may be important aspects of the formation of feeding and mating aggregations, of insect strategies to locate both hosts and mates, of behavioral reproductive isolation among sibling species, and of the regulation of reproduction to coincide with the availability of food and oviposition sites. Knowledge of these relationships is critical to understanding many different areas of the behavioral ecology of plant-feeding insects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.ento.42.1.371
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  • 3
    Electronic Resource
    Electronic Resource
    Alcohol urges in alcohol-dependent drinkers: further validation of the Alcohol Urge Questionnaire in an untreated community clinical population (2002)
    Oxford, UK : Blackwell Science Ltd
    Addiction 97 (2002), S. 0 
    Details
    ISSN: 1360-0443
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Background  Alcohol craving is a key element of the alcohol dependence syndrome. However, there is a lack of consensus about the precise nature of craving and the most appropriate method of measurement. Alcohol urges measured by the Alcohol Urge Questionnaire showed a unidimensional structure and evidence of validity and reliability in a US clinical population. The main aim of this study was to establish the validity of the AUQ in an untreated UK clinical population, and its relationships to drinking and personality factors.Subjects  All subjects (n = 80) were alcohol-dependent (DSM-IV) and presenting for pre-treatment assessment at a community alcohol team in South-west ­London.Method  All subjects completed the AUQ, Severity of Alcohol Dependence ­Questionnaire (SADQ), Spielberger's State Trait Anxiety Inventory (STAI) and Eysenck Personality Questionnaire (EPQ) and provided a breath specimen for alcohol analysis (BAL).Results  Principal components analysis of AUQ revealed one factor which accounted for 69% of variance with high interitem correlations, and an alpha reliability of 0.93. AUQ was significantly correlated with SADQ, BAC, state and trait anxiety and negatively correlated with time since last drink. There were no significant correlations between AUQ and any of the EPQ subscales. SADQ was correlated with neuroticism, but not other EPQ subscales. A regression analysis showed that only SADQ, time since last drink and BAL were significant predictors of alcohol urges.Conclusions  This study confirmed the AUQ factor structure and provided further evidence for the validity of AUQ. The relationship between BAL and urges deserves further research. The results did not support the contention that ­anxiety and personality factors predict urges when drinking-related variables, which also predict urges, are controlled for. The AUQ is a useful measure for clinical and experimental alcohol craving research.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1360-0443.2002.00252.x
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  • 4
    Electronic Resource
    Electronic Resource
    Molecular basis for interaction of the protein tyrosine kinase ZAP-70 with the T-cell receptor (1995)
    [s.l.] : Nature Publishing Group
    Nature 377 (1995), S. 32-38 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The crystal structure of the tandem SH2 domains of human ZAP-70 in complex with a peptide derived from the ζ-subunit of the T-cell receptor reveals an unanticipated interaction between the two domains. A coiled coil of α-helices connects the two SH2 domains, producing an interface that ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/377032a0
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  • 5
    Electronic Resource
    Electronic Resource
    Seasonal abundance and spatial patterns of the predatorLyctocoris campestris in stored corn (1995)
    Springer
    Entomologia experimentalis et applicata 75 (1995), S. 33-42 
    Details
    ISSN: 1570-7458
    Keywords: Lyctocoris campestris ; Anthocoridae ; Heteroptera ; seasonal abundance ; trapping efficiency ; disersion pattern ; stored-product ; predator ; sex-ratio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A two-year sampling study (1992–93) in a flat storage of shelled corn showed that the larger pirate bugLyctocoris campestris (F.) (Heteroptera: Anthocoridae), can be detected by relative sampling techniques as early as the second week of May. The perceived seasonal pattern ofL. campestris varied with trapping method. Of the three relative sampling methods used, probe traps consistently captured more bugs of both sexes than cardboard traps in the grain and sticky flight traps. Probe traps showed a third degree polynomial trend through the season. On the other hand, flight traps were effective for monitoringL. campestris population during early and mid-summer when temperatures were high, but the effectiveness declined during late summer and early fall. Cardboard traps showed the opposite trend to those of flight traps, with increasingL. campestris abundance during the fall when bugs sought refuge as temperature decreased. Sampling date and environmental factors, including grain moisture content, air and grain temperatures were correlated with trap capture. Earlier work reported thatL. campestris showed a highly female biased sex ratio in the field as opposed to a 1∶1 sex ratio in laboratory colonies. The present study found that the estimate of sex ratios in the field can differ with trapping methods. Of the three relative sampling methods used, flight and cardboard traps, in most cases, showed no deviation from a 1∶1, sex ratio. Probe traps, however, indicated a highly female biased sex ratio in field populations. Absolute sampling using a 1140 ml cup sampler also showed no deviation from a 1∶1 sex ratio in the field population. The data suggested that relative sampling methods may be inappropriate for sex ratio estimation in the field. Thus, an absolute sampling method is required for determination of the true field sex ratio ofL. campestris. Analyses of dispersion patterns showed that both males and females ofL. campestris exhibit an aggregated spatial distribution in the grain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382777
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  • 6
    Electronic Resource
    Electronic Resource
    Radiative Transfer in a Turbulent Expanding Molecular Envelope: Application to Mira (1997)
    Springer
    Astrophysics and space science 251 (1997), S. 189-192 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000740823858
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  • 7
    Electronic Resource
    Electronic Resource
    Multiple Origins of Cyclodiene Insecticide Resistance in Tribolium castaneum (Coleoptera: Tenebrionidae) (1999)
    Springer
    Journal of molecular evolution 48 (1999), S. 615-624 
    Details
    ISSN: 1432-1432
    Keywords: Key words: Mutation rate — Migration — Point mutation — Pesticide resistance —γ-Aminobutyric acid receptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. The number of origins of pesticide resistance-associated mutations is important not only to our understanding of the evolution of resistance but also in modeling its spread. Previous studies of amplified esterase genes in a highly dispersive Culex mosquito have suggested that insecticide resistance-associated mutations (specifically a single-gene duplication event) can occur a single time and then spread throughout global populations. In order to provide data for resistance-associated point mutations, which are more typical of pesticide mechanisms as a whole, we studied the number of independent origins of cyclodiene insecticide resistance in the red flour beetle Tribolium castaneum. Target-site insensitivity to cyclodienes is conferred by single point mutations in the gene Resistance to dieldrin (Rdl), which codes for a subunit of a γ-aminobutyric acid (GABA) receptor. These point mutations are associated with replacements of alanine 302 which render the receptor insensitive to block by the insecticide. We collected 141 strains of Tribolium worldwide and screened them for resistance. Twenty-four strains contained resistant individuals. After homozygosing 23 of these resistance alleles we derived a nucleotide sequence phylogeny of the resistant strains from a 694-bp section of Rdl, encompassing exon 7 (which contains the resistance-associated mutation) and part of a flanking intron. The phylogeny also included six susceptible alleles chosen at random from a range of geographical locations. Resistance alleles fell into six clades and three clades contained both resistant and susceptible alleles. Although statistical analysis provided support at only the 5–6% level, the pattern of variation in resistance alleles is more readily explained by multiple independent origins of resistance than by spread of a single resistance-associated mutation. For example, two resistance alleles differed from two susceptible alleles only by the resistance-associated mutation itself, suggesting that they form the susceptible ancestors and that resistance arose independently in several susceptible backgrounds. This suggests that in Tribolium Rdl, de novo mutations for resistance have arisen independently in several populations. Identical alleles were found in geographically distant regions as well, also implying that some Rdl alleles have been exported in stored grain. These differences from the Culex study may stem both from differences in the population genetics of Tribolium versus that of mosquitoes and differences in mutation rates associated with point mutations versus gene duplication events. The Tribolium data therefore suggest that multiple origins of insecticide resistance (associated with specific point mutations) may be more common than the spread of single events. These findings have implications for the way in which we model the evolution and spread of insecticide resistance genes and also suggest that parallel adaptive substitutions may not be uncommon in phyletic evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006504
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  • 8
    Electronic Resource
    Electronic Resource
    Search for Extraterrestrial Origin of Atmospheric Trace Molecules — Radio Sub-MM Observations during the Leonids (1998)
    Springer
    Earth, moon and planets 82-83 (1998), S. 129-140 
    Details
    ISSN: 1573-0794
    Keywords: Early Earth ; H2O ; HCN ; Leonids 1999 ; lower thermosphere ; O3 ; mesosphere ; meteors ; micro-wave ; radio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract To identify the effect of meteor showers on the molecular content of the upper atmosphere of the Earth, we have carried out ground-based observations of atmospheric HCN. HCN radio observations at CSO (Hawaii) on Nov 18/19, 1999, the night after the second Leonid shower maximum, show unusually low HCN abundances above 45 km altitude, which are only recovered after sunrise. We also investigated UARS/HALOE satellite data on H2O and O3. No correlation appears of year round H2O and O3 around 55 km with annual meteor showers, nor with meteor activity at the time of the 1998 Leonid shower.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017075315388
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  • 9
    Electronic Resource
    Electronic Resource
    Spectroscopic evidence for interstellar ices in comet Hyakutake (1996)
    [s.l.] : Nature Publishing Group
    Nature 383 (1996), S. 418-420 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The identification of HNC was made in comet C/1996 B2 (Hyakutake) through its / = 4-3 transition at 362.630092 GHz. The first detection was obtained at the James Clerk Maxwell Telescope (JCMT) on March 16.6ux when the comet was at 1.219 AU from the Sun and 0.305 AU from the Earth. Observations ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/383418a0
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  • 10
    Electronic Resource
    Electronic Resource
    Dried leaves from rocky mountain plants decrease infestation by stored-product beetles (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 127-142 
    Details
    ISSN: 1573-1561
    Keywords: Insecticide ; fumigant ; terpenoids ; Coleoptera ; Bruchidae ; Curculionidae ; camphor ; carvacrol ; Monarda fistulosa ; Artemisia tridentata ; Zabrotes subfasciatus ; Sitophilus oryzae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Leaves of two highly aromatic plants,Artemisia tridentata (Nutt.) andMonarda fistulosa L., prepared according to a patented process, inhibited oviposition by the Mexican bean weevil,Zabrotes subfasciatus (Boheman), in beans at concentrations less than 1% w/w. Both plant species were less effective against the rice weevil,Sitophilus oryzae L., in wheat, with onlyM. fistulosa exhibiting any concentration-dependent activity. The maximal control achieved against this species was less than 50% at 3% w/w. Two less aromatic plant species,Balsamorhiza sagittata (Pursh.) Nutt. andGeranium viscosissimum Fisch. and Mey., caused only low levels of inhibition against both insect species. Volatiles probably caused the response toA. tridentata andM. fistulosa, while the asymptotic concentration dependence for the less volatile plant material was likely caused by behavioral factors related to the physical presence of foreign particulate matter in the foodstuff. Chemical analysis indicated that most of the volatile components from the dried leaf material from all species were terpenoids, with camphor (9.7 mg/g) and 1,8-cineole (4.0 mg/g) being most abundant inA. tridentata and carvacrol (26.3 mg/g) being most abundant inM. fistulosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02036647
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