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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 113 (1998), S. 391-399 
    ISSN: 1432-1939
    Keywords: Key words Feeding niche ; Host range ; Nitrogen ; Sampling effort
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated the guild structure of phytophagous insects on Brassicaceae in Poland and the influence of host-plant parameters (e.g. sampling effort, geographical distribution, taxonomic isolation, nitrogen indicator values) on the species richness of these guilds. The data were extracted from a study published by Lipa et al. The overall number of recorded ectophagous species is about twice the number of endophagous species. Irrespective of the feeding niche, species are predominantly oligophagous, feeding on more than two Brassicaceae genera. The relative importance of endophagous species within the fauna decreases with increasing host range. The sampling effort predicts a high proportion of the variance of alpha-diversity in oligo- and polyphagous insects, but only a low proportion in specialized species. After correction for sampling effort, most of the plant parameters do not explain an additional proportion of the variance in species richness. We hypothesize that the uniform chemical defence system across genera in Brassicaceae is an important factor triggering host range and diversity patterns in phytophagous insects on crucifers.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1420-9071
    Keywords: Tephritidae ; Urophora cardui (L.) ; Urophora stylata (Fab.) ; volatile ; 4-methyl-3Z,5-hexadienoic acid ; gas chromatography ; mass spectrometry ; quantitative analysis ; bioassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new natural substance has been identified in the rectal ampullae of gall-forming fruit flies. The substance was found to be the only volatile compound in the rectal ampulla of maleUrophora cardui andUrophora stylata. GC-MS methods were used to characterize its structure as 4-methyl-3Z,5-hexadienoic acid. Physiological parameters such as the amount of the acid at different ages and under different conditions were investigated. The biological significance of the new volatile as an arresting pheromone was tested in several bioassays. The arrestant function could not be established, but the results gave hints of a territorial function between conspecific males. The results are discussed with respect to gland morphology and predictions of communication models among fruit flies.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 48 (1992), S. 106-111 
    ISSN: 1420-9071
    Keywords: Cantharidin ; Ceratopogonidae ; Atrichopogon oedemerarum ; attractancy ; structure-activity relationship
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Several ceratopogonid flies are attracted to cantharidin and ingest it from both cantharidin-baits and from meloid beetles, one of the few known natural sources for cantharidin. Because meloids are absent in northern Bavaria, and certain canthariphilous flies of the genusAtrichopogon are temporarily associated with certain plants (Apiaceae, Aristolochiaceae), it was suggested that canthariphilous ceratopogonids might be generally attracted by chemically similar plant-derived compounds. At first the seasonal fluctuating attractancy, sex ratio and behaviour ofA. oedemerarum Storå was studied at cantharidin baits. Synthetic cantharidin analogues exhibited an attractancy forA. oedemerarum if the exo,exo-7-oxabicyclo[2.2.1]heptane skeleton of cantharidin was associated with a 2,3-dicarboxylic anhydride or a 2,3-γ-lactone. According to structure-activity studies, the analogues seem to fit best into the active site of the receptor if the carbonyl function of the γ-lacton is in the exo- and 2-position. This is the first report indicating that molecules other than cantharidin are attractive for canthariphilous insects.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 2016-07-26
    Description: Fault rock low-temperature thermochronometry can inform the timing, temperature, and significance of hydrothermal fluid circulation in fault systems. We demonstrate this with combined hematite (U-Th)/He (He) dating, and sandstone apatite fission-track (AFT) and apatite and zircon (U-Th)/He (He) thermochronometry from fault-related fissures on the Gower Peninsula, Wales. Hematite He dates from 141 ± 5.1 Ma to 120 ± 5.0 Ma overlap with a 131 ± 20 Ma sandstone infill AFT date. Individual zircon He dates are 402–260 Ma, reflecting source material erosion, and imply a maximum Late Permian infill depositional age. Burial history reconstruction reveals modern exposures were not buried sufficiently in the Triassic–Early Cretaceous to have caused reheating to temperatures necessary to reset the AFT or hematite He systems, and thus these dates cannot reflect cooling due to erosion alone. Hot fluids circulating through fissures in the Early Cretaceous reset the AFT system. Hematite was either also reset by fluids or precipitated from these fluids. Similar hematite He dates from fault-related mineralization in south Glamorgan (Wales) and Cumbria (England) imply concomitant regional hot groundwater flow along faults. In this example, hydrothermal fluid circulation, coeval with North Atlantic rifting, occurred in higher-permeability fissures and fault veins long after they initially formed, directly influencing local and regional geothermal gradients.
    Print ISSN: 1941-8264
    Electronic ISSN: 1947-4253
    Topics: Geosciences
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  • 5
    Publication Date: 2017-09-02
    Description: Purpose: The phase II MONARCH 1 study was designed to evaluate the single-agent activity and adverse event (AE) profile of abemaciclib, a selective inhibitor of CDK4 and CDK6, in women with refractory hormone receptor–positive (HR + ), HER2 – metastatic breast cancer (MBC). Experimental Design: MONARCH 1 was a phase II single-arm open-label study. Women with HR + /HER2 – MBC who had progressed on or after prior endocrine therapy and had 1 or 2 chemotherapy regimens in the metastatic setting were eligible. Abemaciclib 200 mg was administered orally on a continuous schedule every 12 hours until disease progression or unacceptable toxicity. The primary objective of MONARCH 1 was investigator-assessed objective response rate (ORR). Other endpoints included clinical benefit rate, progression-free survival (PFS), and overall survival (OS). Results: Patients ( n = 132) had a median of 3 (range, 1–8) lines of prior systemic therapy in the metastatic setting, 90.2% had visceral disease, and 50.8% had ≥3 metastatic sites. At the 12-month final analysis, the primary objective of confirmed objective response rate was 19.7% (95% CI, 13.3–27.5; 15% not excluded); clinical benefit rate (CR+PR+SD≥6 months) was 42.4%, median progression-free survival was 6.0 months, and median overall survival was 17.7 months. The most common treatment-emergent AEs of any grade were diarrhea, fatigue, and nausea; discontinuations due to AEs were infrequent (7.6%). Conclusions: In this poor-prognosis, heavily pretreated population with refractory HR + /HER2 – metastatic breast cancer, continuous dosing of single-agent abemaciciclib was well tolerated and exhibited promising clinical activity. Clin Cancer Res; 23(17); 5218–24. ©2017 AACR .
    Print ISSN: 1078-0432
    Electronic ISSN: 1557-3265
    Topics: Medicine
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  • 6
    Publication Date: 2020-02-12
    Keywords: 550 - Earth sciences
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 7
    Publication Date: 2021-11-01
    Description: Situated in the western Erzgebirge metallogenetic province (Vogtland, Germany), the Eichigt prospect is associated with several quartz-Mn-Fe-oxyhydroxide veins that are exposed at surface. Bulk-rock geochemical assays of vein material yield high concentrations of Li (0.6–4.1 kg/t), Co (0.6–14.7 kg/t), and Ni (0.2–2.8 kg/t), as well as significant quantities of Mn, Cu, and light rare earth elements, a very unusual metal tenor closely resembling the mixture of raw materials needed for Li-ion battery production. This study reports on the results of a first detailed investigation of this rather unique polymetallic mineralization style, including detailed petrographic and mineralogical studies complemented by bulk rock geochemistry, electron microprobe analyses, and laser ablation inductively coupled mass spectrometry. The mineralized material comprises an oxide assemblage of goethite hematite, hollandite, and lithiophorite that together cement angular fragments of vein quartz. Lithiophorite is the predominant host of Li (3.6–11.1 kg/t), Co (2.5–54.5 kg/t), and Ni (0.2–8.9 kg/t); Cu is contained in similar amounts in hollandite and lithiophorite whereas light rare earth elements (LREE) are mainly hosted in microcrystalline rhabdophane and florencite, which are finely intergrown with the Mn-Fe-oxyhydroxides. 40Ar/39Ar ages (~ 40–34 Ma) of coronadite group minerals coincide with tectonic activity related to the Cenozoic Eger Graben rifting. A low-temperature hydrothermal overprint of pre-existing base metal sulfide-quartz mineralization on fault structures that were reactivated during continental rifting is proposed as the most likely origin of the polymetallic oxyhydroxide mineralization at Eichigt. However, tectonically enhanced deep-reaching fracture-controlled supergene weathering cannot be completely ruled out as the origin of the mineralization.
    Language: English
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 8
    Publication Date: 2021-12-17
    Description: Deportment data is essential for the planning of mining and minerals processing operations. This need is particularly tangible for deposits of noble metals, such as gold and silver. Therefore, the current paucity of published gold and silver deportment data for individual ore deposits and districts – and the concomitant lack of understanding how this relates to salient geological and mineralogical features of these deposits – is surprising. In the present study, we apply a combination of bulk geochemistry, laser ablation-inductively coupled plasma-mass spectrometry, electron microprobe analysis, and mineral liberation analysis to gold- and silver-rich samples from the epithermal Freiberg Ag-Pb-Zn district, to investigate variability in gold and silver deportments, as well as the corresponding geological/mineralogical controls. The results show that the main carriers of gold are electrum and arsenopyrite, whereas silver is mostly hosted by Ag-sulfosalts (pyrargyrite, miargyrite, polybasite) and fahlore (freibergite). Deportments vary greatly between samples. These variations can be related to the relative abundances of different minerals within the samples, which in turn reflect their spatio-temporal position within the district. Comparisons with other epithermal Ag-Pb-Zn districts similar to Freiberg indicate that the results presented here are of general significance.
    Language: English
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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