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  • 1
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Dwarf galaxies have attracted increased attention in recent years, because of their susceptibility to galaxy transformation processes within rich galaxy clusters. Direct evidence for these processes, however, has been difficult to obtain, with a small number of diffuse light trails and ...
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0022-1910
    Keywords: Benzaldehyde ; Chemoreceptors ; Cotton ; Oviposition deterrent ; Sensillum ; Synergism ; Terpenes
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 74 (1995), S. 71-82 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Spodoptera littoralis ; oviposition ; deterrents ; feeding ; larval experience ; induction ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Females ofSpodoptera littoralis Boisd. (Lepidoptera: Noctuidae) with different feeding experiences during their larval development were tested for their ovipositional response to methanol extracts of larval frass and semisynthetic diets. The effect of the following frass, diet and diet component extracts was tested: (a) frass fromS. littoralis orAgrotis segetum larvae fed on a potato-based diet; (b) frass fromS. littoralis larvae fed on a wheat germ-based diet; (c) potato and wheat germ-based diets; and (d) potatoes and wheat germ. Ovipositing females without prior experience of the potato diet were deterred by extracts of: (1) larval frass from either species fed on potato diet; (2) the potato-based diet; (3) potato. Also females with experience of the potato diet during only a part of their larval development were deterred from oviposition by frass of larvae reared on the potato diet and by the diet itself. However, for females reared on the potato diet for their entire larval development, oviposition was no longer deterred by either of the three extracts listed above. Extracts of: (1) frass from larvae of either species reared on wheat germ diet: (2) the wheat germ diet; or (3) wheat germ did not significantly affect oviposition. Females with ablated antennae were still deterred by frass extracts from larvae fed on potato diet, when they had been reared on the wheat germ diet. In feeding experiments, larvae of larval stage one and of larval stage three-four reared on either of the two diets preferred to feed on the wheat germ diet. However, the preference was significantly stronger for larvae with no prior contact with the potato diet. The effect of larval experience on the loss of oviposition-deterring activity by extracts of larval frass, diets and diet components is discussed in view of induction and selection.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 91 (1999), S. 431-441 
    ISSN: 1570-7458
    Keywords: repellent ; Ixodes ricinus ; host-seeking ; bioassay ; tick ; DEET
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A bioassay was developed to examine the response of ticks towards potential repellents that may protect vertebrates against tick bites. Such tick repellents must be effective despite the unavoidable presence of various attractive host-derived stimuli. Therefore, a moving-object-bioassay (MO-bioassay) was developed that mimicks body warmth and movement of vertebrates by a rotating and heated drum. Compounds which were tested for their effects on ticks were applied onto a small elevated area of the drum. Ticks were allowed to approach the drum by walking on a glass rod which ended ≈1 mm away from the local elevation. Ticks could cling to this elevation that intermittently passed by, whereas the remaining drum surface was too far away from the tip of the rod to be contacted by the ticks. Without the presence of any repellents, 85.5% of 600 hungry, field-collected Ixodes ricinus nymphs moved to the heated, rotating drum within 2 min. Further experiments with unfed I. ricinus nymphs were performed to test whether one established and two potential tick repellents elicit an avoidance reaction in the ticks despite the proven attractiveness of the drum. Freshly applied DEET (N,N-diethyl-m-toluamide) at a concentration of 0.11 mg cm−2 proved active as a repellent in the MO-bioassay over a distance of a few mm as well as by direct contact. A similar repellent effect was observed with (−)-myrtenal at 1 mg cm−2, but not at 0.1 mg cm−2, indicating that this terpenaldehyde is a weaker repellent for I. ricinus nymphs than DEET. No repellent effect was observed with camphor (0.1 mg cm−2). The MO-bioassay thus is a rapid, simple and low-cost test method allowing the investigation of tick host-contact behaviour as well as the screening of candidate repellents which are either perceived as volatiles or via contact chemoreception.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 87 (2000), S. 216-219 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Notes: Abstract  The role of a general green leaf volatile (glv) in host finding by larvae of the oligophagous chrysomelid Cassida denticollis was investigated using a new bioassay which takes into account the need for neonate larvae of this species to climb fresh host plants from the ground. A "stem arena" was designed in which plant stems of the host, tansy (Tanacetum vulgare), and stem dummies (tooth picks), both wrapped in perforated filter paper, were offered to neonate larvae. The wrapping allowed olfactory responses to be tested by preventing access to contact stimuli of stems and dummies. Larvae significantly preferred to climb the wrapped tansy stems over dummies after a period of 15 min. The test glv, (Z)-3-hexen-1-ol, was not attractive when applied to dummies. However, when the glv was applied to the bottom of the arena, the ability of larvae to discriminate between host stems and untreated dummies was significantly enhanced. More larvae climbed wrapped host stems than dummies even within 5 min. While numerous other herbivorous insects are known to be directly attracted by glv, this study shows that a singly offered glv on its own is unattractive to an herbivore but enhances the herbivore's ability to differentiate between host and nonhost plants.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 79 (1992), S. 271-274 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 72 (1985), S. 485-486 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 48 (1992), S. 1023-1027 
    ISSN: 1420-9071
    Keywords: Chrysolina fuliginosa ; Coleoptera ; Chrysomelidae ; beetles ; cardenolides ; eggs ; glands ; chemical defence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Besides the known sarmentogenin 3-O-β-D-allopyranoside (1) and digitoxigenin-3-O-[β-D-xylopyranosyl-(1→4)-2′, 3′-di-O-acetyl-β-D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by1H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Herz-, Thorax- und Gefässchirurgie 12 (1998), S. 94-99 
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Karotischirurgie – Koronarchirurgie – Eversions-Endarterektomie ; Key words Carotid surgery – coronary surgery – eversion endarterectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Coronary artery bypass grafting combined with eversion endarterectomy of the internal carotid artery was performed in 27 patients between October, 1993, and October, 1996. Preoperatively, 2 patients had suffered hemiparesis. Among the remaining patients who presented with asymptomatic stenosis of the internal carotid artery the indication for surgery was based on a hemodynamically significant stenosis of at least 90%. In 23 patients the stenosis was unilateral whereas in 4 patients bilateral stenosis of the internal carotid artery with a maximum of 70% was present. In these patients the choice of the operative site was based on clinical symptoms or on the degree of the stenosis. In 5 patients kinking of the internal carotid artery was demonstrated. Patients with unilateral stenosis of the internal carotid artery and contralateral occlusion underwent conventional thrombendarterectomy with patch plasty. The mean clamping time for the carotid artery was 12.6 minutes (±3,5 minutes). An intraluminal shunt was not used in any patient. No patient suffered from persistent neurological symptoms associated with the procedure. Ultrasound evaluation of the carotid bifurcation between postoperative day 5 and 7 as well as after a mean period of 12.6 (±6.8) months revealed an unimpeded flow pattern within the carotid bifurcation. Eversion endarterectomy in conjunction with open heart surgery represents a safe and fast operative procedure to completely desobliterate unilateral carotid lesions with optional shortening of an elongated vascular segment.
    Notes: Zusammenfassung Im Zeitraum von Oktober 1993 bis Oktober 1996 wurde bei 27 Patienten simultan zur Koronaroperation eine Eversions-Endarterektomie (EEA) der A. carotis interna durchgeführt. Präoperativ hatten 2 Patienten eine Hemiparese erlitten, 3 Patienten hatten über transitorisch ischämische Attacken (TIA) berichtet. Bei den übrigen Patienten mit asymptomatischer Karotis-Interna-Stenose wurde die Operationsindikation aufgrund einer hochgradigen, wenn auch klinisch asymptomatischen Stenosierung (〉90%) gestellt. Bei 23 Patienten lag eine einseitige Karotisstenose vor, bei 4 Patienten war auch die Gegenseite bis maximal 70% stenosiert, wobei sich die Wahl der Operationsseite nach der klinischen Symptomatik oder dem Grad der Stenose richtete. Insgesamt 5 Patienten zeigten eine Elongation der A. carotis interna mit Knickbildung. Ausgeschlossen von der EEA wurden 6 Patienten mit einseitiger Karotis-Interna-Stenose und gleichzeitigem Verschluß der Gegenseite, die mit konventioneller Thrombendarterektomie und Patch-Plastik operiert wurden. Die mittlere Abklemmzeit der A. carotis betrug 12,6 (±3,5) min. Eine intraluminale Shunteinlage fand in keinem Fall statt. Peri- und postoperativ kam es bei keinem Patienten zu einer neu aufgetretenen neurologischen Symptomatik. Duplex-B-Kontrollen der Karotisbifurkation unmittelbar perioperativ zwischen Tag 5 und 7 sowie postoperativ nach im Mittel 12,6 (±6,8) Monaten zeigten unauffällige Strömungsverhältnisse im Bereich der Karotis-Neobifurkation. Die Karotis-Eversions-Endarterektomie stellt ein sicheres und rasches operatives Verfahren dar, um im Zusammenhang mit der Herzoperation eine einseitige Karotis-Läsion zu desobliterieren und gleichzeitig eine Verkürzung des elongierten Gefäßabschnittes vorzunehmen.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 17 (1991), S. 2323-2332 
    ISSN: 1573-1561
    Keywords: Galeruca tanaceti ; Coleoptera ; Chrysomelidae ; anthraquinones ; eggs ; larvae ; hemolymph ; ovaries ; Tanacetum vulgäre ; Achillea millefolium ; feeding deterrence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The overwintering eggs and the larvae of the leaf beetleGaleruca tanaceti (L.) contain hydroxylated anthraquinones. In both developmental stages, l,8-dihydroxy-3-methylanthraquinone (= chrysophanol) and 1,8-di-hydroxyanthraquinone (= chrysazin) were detected by GC-MS and GC-FTIR analyses. In the eggs, chrysazin was found only in traces. Anthraquinones were also present in ovaries and hemolymph of gravid females, which were investigated in order to examine the incorporation of these substances into the eggs. Neither in acidified nor in nonacidified extracts of the host plantsTanacetum vulgäre L. andAchillea millefolium L. were anthraquinones found. The activity of these anthraquinones as chemical defense substances was proved in bioassays with the antMyrmica ruginodis NYL. Further possible biological significances of anthraquinones are discussed.
    Type of Medium: Electronic Resource
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