472 research outputs found

    Glucosinolates on the leaf surface perceived by insect herbivores: review of ambiguous results and new investigations

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    Herbivorous insects identify their host plants either by structural features, chemical cues, or a combination. Some insects probe the host leaf prior feeding or oviposition, other species use olfactorial cues or compounds somewhere on the surface. Insects attacking Brassicaceae are no exception, some are attracted and stimulated by volatile isothiocyanates (ITC), many others depend fully on the non-volatile glucosinolates (GS) for host-plant recognition and acceptance. Since most insects have no access to the leaf interior investigators concluded that GS must be present on the leaf surface and ITC in the headspace. However, peelings of mechanically removed surface waxes were devoid of measurable amounts of GS, whereas solvent surface extractions revealed a correlation between stomatal conditions and GS concentrations. Both observations lead to the conclusion that the presence of GS on the top leaf surface is rather unlikely. In the experimental part we show that a chloroform/methanol/water (2:1:1 vol/vol/vol) solvent leaf extract contains GS and, in addition, thia-triaza-fluorenes (TTF), other oviposition stimulants of the cabbage root fly, Delia radicum. Electrophysiological investigations showed that both, GS and TTF stimulated specific receptor neurones of the fly. We suggest that these compounds probably originated from deeper leaf layers and that herbivorous insects may penetrate the wax layer and perceive the stimulating compounds in deeper layers or through the stomat

    In Vivo Degradation Behavior of the Magnesium Alloy LANd442 in Rabbit Tibiae

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    In former studies the magnesium alloy LAE442 showed promising in vivo degradation behavior and biocompatibility. However, reproducibility might be enhanced by replacement of the rare earth composition metal "E" by only a single rare earth element. Therefore, it was the aim of this study to examine whether the substitution of "E" by neodymium ("Nd") had an influence on the in vivo degradation rate. LANd442 implants were inserted into rabbit tibiae and rabbits were euthanized after 4, 8, 13 and 26 weeks postoperatively. In vivo μCT was performed to evaluate the in vivo implant degradation behaviour by calculation of implant volume, density true 3-D thickness and corrosion rates. Additionally, weight loss, type of corrosion and mechanical stability were appraised by SEM/EDS-analysis and three-point bending tests. Implant volume, density and true 3-D thickness decreased over time, whereas the variance of the maximum diameters within an implant as well as the corrosion rate and weight loss increased. SEM examination revealed mainly pitting corrosion after 26 weeks. The maximum bending forces decreased over time. In comparison to LAE442, the new alloy showed a slower, but more uneven degradation behavior and less mechanical stability. To summarize, LANd442 appeared suitable for low weight bearing bones but is inferior to LAE442 regarding its degradation morphology and strength

    Revision der Gattung Oncophorus (Musci, Dicranaceae)

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    The 12 species so far comprised in the genus Oncophorus are reduced to 6. Oncophorus fauriei Card. ex Ihs. and O. muratae Broth. ex Ihs. are synonymous with C. crispifolius, O. decumbens (Thwait. & Mitt.) Broth. is a species of Dicranum, O. gracilentus Zeng is a species of Dicranella, O. gracillimus Dix. is a synonym of O. wahlenbergii, O. sardous Herz. a synonym of O. virens.Von den 12 bisher in der Gattung Oncophorus eingeschlossenen Arten werden 6 anerkannt. Oncophorus fauriei Card. ex Ihs. und O. mutratae Broth. ex Ihs. sind ein Synonyme von C. crispifolius, O. decumbens (Thwait. & Mitt.) Broth. ist ein Dicranum, O. gracilentus Zeng gehört zu Dicranella, O. gracillimus Dix. ist ein Synonym von O. wahlenbergii, O. sardous Herz. ein Synonym von O. virens

    Influence of Heat Treatment on the Degradation Behaviour of Degradable Magnesium Based Implants

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    Aim of the study was to characterise the influence of heat treatment on the degradation behaviour and stability of degradable magnesium based implants. For this purpose two groups (untreated/ heat treated) of LAE442 pins were separately analysed in an in vitro and in vivo study. The corrosion behaviour was evaluated during 8 weeks degradation in SBF (in vitro) and 48 weeks degradation intramedullary in the rabbit tibia (in vivo). The analyses were made by using μ-computed tomography and three-point-bending tests. Heat treatment led to altered mechanical and corrosion properties of LAE442.While the initial stability declined significantly a reduction of the degradation rate over either in vitro and in vivo evaluation period is determined. If these alterations are still reasonable for osteosynthesis implants remains to be investigated in further projects.DFG/SFB/59

    Increased accumulation of magnetic nanoparticles by magnetizable implant materials for the treatment of implant-associated complications

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    Background: In orthopaedic surgery, accumulation of agents such as anti-infectives in the bone as target tissue is difficult. The use of magnetic nanoparticles (MNPs) as carriers principally enables their accumulation via an externally applied magnetic field. Magnetizable implants are principally able to increase the strength of an externally applied magnetic field to reach also deep-seated parts in the body. Therefore, the integration of bone-addressed therapeutics in MNPs and their accumulation at a magnetic orthopaedic implant could improve the treatment of implant related infections. In this study a martensitic steel platelet as implant placeholder was used to examine its accumulation and retention capacity of MNPs in an in vitro experimental set up considering different experimental frame conditions as magnet quantity and distance to each other, implant thickness and flow velocity.Results: The magnetic field strength increased to approximately 112% when a martensitic stainless steel platelet was located between the magnet poles. Therewith a significantly higher amount of magnetic nanoparticles could be accumulated in the area of the platelet compared to the sole magnetic field. During flushing of the tube system mimicking the in vivo blood flow, the magnetized platelet was able to retain a higher amount of MNPs without an external magnetic field compared to the set up with no mounted platelet during flushing of the system. Generally, a higher flow velocity led to lower amounts of accumulated MNPs. A higher quantity of magnets and a lower distance between magnets led to a higher magnetic field strength. Albeit not significantly the magnetic field strength tended to increase with thicker platelets.Conclusion: A martensitic steel platelet significantly improved the attachment of magnetic nanoparticles in an in vitro flow system and therewith indicates the potential of magnetic implant materials in orthopaedic surgery. The use of a remanent magnetic implant material could improve the efficiency of capturing MNPs especially when the external magnetic field is turned off thus facilitating and prolonging the effect. In this way higher drug levels in the target area might be attained resulting in lower inconveniences for the patient

    Neuropeptides in the Antennal Lobe of the Yellow Fever Mosquito, Aedes aegypti.

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    For many insects, including mosquitoes, olfaction is the dominant modality regulating their behavioral repertoire. Many neurochemicals modulate olfactory information in the central nervous system, including the primary olfactory center of insects, the antennal lobe. The most diverse and versatile neurochemicals in the insect nervous system are found in the neuropeptides. In the present study, we analyzed neuropeptides in the antennal lobe of the yellow fever mosquito, Aedes aegypti, a major vector of arboviral diseases. Direct tissue profiling of the antennal lobe by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry indicated the presence of 28 mature products from 10 different neuropeptide genes. In addition, immunocytochemical techniques were used to describe the cellular location of the products of up to seven of these genes within the antennal lobe. Allatostatin A, allatotropin, SIFamide, FMRFamide-related peptides, short neuropeptide F, myoinhibitory peptide, and tachykinin-related peptides were found to be expressed in local interneurons and extrinsic neurons of the antennal lobe. Building on these results, we discuss the possible role of neuropeptide signaling in the antennal lobe of Ae. aegypti. J. Comp. Neurol. 522:592-608, 2014. (c) 2013 Wiley Periodicals, Inc

    Assessment Tools in Clinical and Counseling Psychology

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    Evidence-based assessment (EBA) is defined as the use of standardized assessment tools that have research support for their psychometric properties (Jensen-Doss & Hawley, 2010). Assessment is a key aspect of the therapeutic process. It involves screening individuals who are at risk for a particular mental health concern, determining the severity of a given issue, and monitoring the effectiveness of treatment. EBA allows for best practice by providing empirically sound, valid, reliable measures of assessment. The broad areas of anxiety and depression represent extremely common disorders. Because of their high prevalence, evidence-based assessment tools catered toward depression and anxiety could be useful in primary care offices, inpatient clinics, and outpatient facilities. These measures take only minutes to complete and are easy to score and interpret. This reduces the strain on time and resources that longer, more complex measures would create. These instruments, along with many others, show that EBA is possible and plausible. The term “evidence-based” should not be reserved for treatment alone, but rather it should be integrated into all parts of the therapeutic process

    Filter Methods for Feature Selection in Supervised Machine Learning Applications : Review and Benchmark

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    The amount of data for machine learning (ML) applications is constantly growing. Not only the number of observations, especially the number of measured variables (features) increases with ongoing digitization. Selecting the most appropriate features for predictive modeling is an important lever for the success of ML applications in business and research. Feature selection methods (FSM) that are independent of a certain ML algorithm — so-called filter methods — have been numerously suggested, but little guidance for researchers and quantitative modelers exists to choose appropriate approaches for typical ML problems. This review synthesizes the substantial literature on feature selection benchmarking and evaluates the performance of 58 methods in the widely used R environment. For concrete guidance, we consider four typical dataset scenarios that are challenging for ML models (noisy, redundant, imbalanced data and cases with more features than observations). Drawing on the experience of earlier benchmarks, which have considered much fewer FSMs, we compare the performance of the methods according to four criteria (predictive performance, number of relevant features selected, stability of the feature sets and runtime). We found methods relying on the random forest approach, the double input symmetrical relevance filter (DISR) and the joint impurity filter (JIM) were well-performing candidate methods for the given dataset scenarios

    Modernisierung plus Traditionalisierung: Wertewandel und Werteaffirmation von Swaminarayan-Frauen in der Diaspora

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    Das Guinness Buch der Rekorde verzeichnet den 1995 eröffneten Swaminarayan-Tempel in einem nordwestlichen Stadtteil der britischen Hauptstadt London als den größten hinduistischen Tempel außerhalb des indischen Subkontinents. Ohne finanzielle Unterstützung von außen hatte eine hinduistische Reformgemeinschaft in der Diaspora die Mittel dazu aufgebracht, sich mit einer ganz im Gujarati-Stil gehaltenen Kultstätte ein viel besuchtes Monument des selbstbewussten Hinduismus in einer stark säkularisierten Umwelt zu setzen. Der folgende Artikel beschäftigt sich mit den Frauen, die sich in und um den Tempel engagieren, hier einen Lebensmittelpunkt sehen und ihre Identität mit der hergebrachten Tradition verknüpfen wollen. Bei allen von mir interviewten Frauen zeigte sich eine ausgesprochene Bereitschaft, westliche und säkulare Lebensformen selektiv anzunehmen, während gleichzeitig „Hindu-Identität“ unangetastet bleiben soll
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