86 research outputs found

    Finding the Area of Origin of the Horse-Chestnut Leaf Miner : a Challenge

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    CABI Bioscience Switzerland centreTechnological Educational Institution of KavalaInstitute of Animal EcologyUniversity pf Natural Resources and Applied Life Sciences, Institute of Plant ProtectionUniversity of SopronInstitute of ZoologyInstitute of Organic Chemistry and BiochemistryUniversity of ForestryProceedings : IUFRO Kanazawa 2003 "Forest Insect Population Dynamics and Host Influences"., Scedule:14-19 September 2003, Vemue: Kanazawa Citymonde Hotel, Kanazawa, Japan, Joint metting of IUFRO working groups : 7.01.02 Tree resistance to Insects | 7.03.06 Integrated management of forset defoloating insects | 7.03.07 Population dynamics of forest insects, Sponsored by: IUFRO-J | Ishikawa Prefecture | Kanazawa City | 21st-COE Program of Kanazawa University, Editors: Kamata, Naoto | Liebhold, Nadrew M. | Quiring, Dan T. | Clancy, Karen M

    Temporal and spatial variations in the parasitoid complex of the horse chestnut leafminer during its invasion of Europe

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    The enemy release hypothesis posits that the initial success of invasive species depends on the scarcity and poor adaptation of native natural enemies such as predators and parasitoids. As for parasitoids, invading hosts are first attacked at low rates by a species-poor complex of mainly generalist species. Over the years, however, parasitoid richness may increase either because the invading host continuously encounters new parasitoid species during its spread (geographic spread-hypothesis) or because local parasitoids need different periods of time to adapt to the novel host (adjustment-hypothesis). Both scenarios should result in a continuous increase of parasitoid richness over time. In this study, we reconstructed the development of the hymenopteran parasitoid complex of the invasive leafminer Cameraria ohridella (Lepidoptera, Gracillariidae). Our results show that the overall parasitism rate increases as a function of host residence time as well as geographic and climatic factors, altogether reflecting the historic spread of C. ohridella. The same variables also explain the individual parasitism rates of several species in the parasitoid complex, but fail to explain the abundance of others. Evidence supporting the “geographic spread-hypothesis” was found in the parasitism pattern of Cirrospilus talitzkii (Hymenoptera, Eulophidae), while that of Pediobius saulius, another eulophid, indicated an increase of parasitism rates by behavioral, phenological or biological adjustments. Compared to fully integrated host-parasitoid associations, however, parasitism rates of C. ohridella are still very low. In addition, the parasitoid complex lacks specialists, provided that the species determined are valid and not complexes of cryptic (and presumably more specialized) species. Probably, the adjustment of specialist parasitoids requires more than a few decades, particularly to invaders which establish in ecological niches free of native hosts, thus eliminating any possibility of recruitment of pre-adapted parasitoids

    Management of an extrasphincteric fistula in an HIV-positive patient by using fibrin glue: a case report with tips and tricks

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    <p>Abstract</p> <p>Background</p> <p>Individuals with impaired immunity are at higher risk of perianal diseases. Concerning complex anal fistulas impaired healing and complication rates are also higher. Definitive treatment of a fistula aims controlling the purulent discharge and prevents its recurrence. It depends mainly on the trajectory of the fistula and the underlying disease.</p> <p>We present a case of a HIV-positive patient with a complex extrasphincteric anal fistula who was treated successfully with fibrin glue application. We further, discuss tips and tricks when applying fibrin glue as plugging material in complex anal fistulas.</p> <p>Case presentation</p> <p>A sixty-one-year-old HIV-positive male referred to us for warts and extrasphincteric fistula. Because of the patients' immunological status, we opted against surgery and recommended fibrin glue plugging. The patient was discharged the same day. A follow-up examination was performed 5 days after the initial fibrin glue application showing that the fistula canal was obstructed. Three months and a year post-intervention the fistula tract remains closed.</p> <p>Conclusion</p> <p>The best treatment for a disease gives at least the same result with the other treatments with minimised risk for the life of the patient and minimal application effort. Conservative closure of fistula with fibrin plugging is simple, safe and with less morbidity than surgery. Our patient was successfully treated without endangering his life despite his precarious medical state. Not everybody believes in the effectiveness of fibrin glue application, however we consider this solution in cases of complex fistulas at least as primary procedure in special populations such as the immunosupressed.</p

    Comparison between human fetal and adult skin

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    Healing of early-gestation fetal wounds results in scarless healing. Since the capacity for regeneration is probably inherent to the fetal skin itself, knowledge of the fetal skin composition may contribute to the understanding of fetal wound healing. The aim of this study was to analyze the expression profiles of different epidermal and dermal components in the human fetal and adult skin. In the human fetal skin (ranging from 13 to 22 weeks’ gestation) and adult skin biopsies, the expression patterns of several epidermal proteins (K10, K14, K16, K17, SKALP, involucrin), basement membrane proteins, Ki-67, blood vessels and extracellular matrix proteins (fibronectin, chondroitin sulfate, elastin) were determined using immunohistochemistry. The expression profiles of K17, involucrin, dermal Ki-67, fibronectin and chondroitin sulfate were higher in the fetal skin than in adult skin. In the fetal skin, elastin was not present in the dermis, but it was found in the adult skin. The expression patterns of basement membrane proteins, blood vessels, K10, K14, K16 and epidermal Ki-67 were similar in human fetal skin and adult skin. In this systematic overview, most of the differences between fetal and adult skin were found at the level of dermal extracellular matrix molecules expression. This study suggests that, especially, dermal components are important in fetal scarless healing

    Two spatiotemporally distinct value systems shape reward-based learning in the human brain

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    Avoiding repeated mistakes and learning to reinforce rewarding decisions is critical for human survival and adaptive actions. Yet, the neural underpinnings of the value systems that encode different decision-outcomes remain elusive. Here coupling single-trial electroencephalography with simultaneously acquired functional magnetic resonance imaging, we uncover the spatiotemporal dynamics of two separate but interacting value systems encoding decision-outcomes. Consistent with a role in regulating alertness and switching behaviours, an early system is activated only by negative outcomes and engages arousal-related and motor-preparatory brain structures. Consistent with a role in reward-based learning, a later system differentially suppresses or activates regions of the human reward network in response to negative and positive outcomes, respectively. Following negative outcomes, the early system interacts and downregulates the late system, through a thalamic interaction with the ventral striatum. Critically, the strength of this coupling predicts participants’ switching behaviour and avoidance learning, directly implicating the thalamostriatal pathway in reward-based learning

    A new model for preclinical testing of dermal substitutes for human skin reconstruction

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    BACKGROUND: Currently, acellular dermal substitutes used for skin reconstruction are usually covered with split-thickness skin grafts. The goal of this study was to develop an animal model in which such dermal substitutes can be tested under standardized conditions using a bioengineered dermo-epidermal skin graft for coverage. METHODS: Bioengineered grafts consisting of collagen type I hydrogels with incorporated human fibroblasts and human keratinocytes seeded on these gels were produced. Two different dermal substitutes, namely Matriderm(®), and an acellular collagen type I hydrogel, were applied onto full-thickness skin wounds created on the back of immuno-incompetent rats. As control, no dermal substitute was used. As coverage for the dermal substitutes either the bioengineered grafts were used, or, as controls, human split-thickness skin or neonatal rat epidermis were used. Grafts were excised 21 days post-transplantation. Histology and immunofluorescence was performed to investigate survival, epidermis formation, and vascularization of the grafts. RESULTS: The bioengineered grafts survived on all tested dermal substitutes. Epidermis formation and vascularization were comparable to the controls. CONCLUSION: We could successfully use human bioengineered grafts to test different dermal substitutes. This novel model can be used to investigate newly designed dermal substitutes in detail and in a standardized way

    Biologie, Frassverhalten und Parasitenkomplex von Platycampus luridiventris Fallen (Nematinae, Tenthredinidae), einer Erlen-Blattwespe mit aberranter Lebensweise, im Vergleich zu anderen Nematinen

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    SIGLEAvailable from TIB Hannover: MA 7027 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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