62 research outputs found

    Connecting Earth observation to high-throughput biodiversity data

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    Understandably, given the fast pace of biodiversity loss, there is much interest in using Earth observation technology to track biodiversity, ecosystem functions and ecosystem services. However, because most biodiversity is invisible to Earth observation, indicators based on Earth observation could be misleading and reduce the effectiveness of nature conservation and even unintentionally decrease conservation effort. We describe an approach that combines automated recording devices, high-throughput DNA sequencing and modern ecological modelling to extract much more of the information available in Earth observation data. This approach is achievable now, offering efficient and near-real-time monitoring of management impacts on biodiversity and its functions and services

    Environmental factors shaping the distribution of common wintering waterbirds in a lake ecosystem with developed shoreline

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    In this study, we tested whether the spatial distribution of waterbirds is influenced by shoreline urbanization or other habitat characteristics. We conducted monthly censuses along shoreline sections of a continental lake (Lake Balaton, Hungary) to assess the abundance of 11 common species that use this lake as a feeding and staging area during migration and winter. We estimated the degree of urbanization of the same shoreline sections and also measured other habitat characteristics (water depth, extent of reed cover, biomass of zebra mussels, distances to waste dumps and to other wetlands). We applied linear models and model averaging to identify habitat variables with high relative importance for predicting bird distributions. Bird abundance and urbanization were strongly related only in one species. Other habitat variables exhibited stronger relationships with bird distribution: (1) diving ducks and coots preferred shoreline sections with high zebra mussel biomass, (2) gulls preferred sites close to waste dumps, and (3) the abundances of several species were higher on shoreline sections close to other wetlands. Our findings suggest that the distribution of waterbirds on Lake Balaton is largely independent of shoreline urbanization and influenced by food availability and connectivity between wetlands

    An Ultrasound Assisted Anchoring Technique (BoneWelding® Technology) for Fixation of Implants to Bone – A Histological Pilot Study in Sheep

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    The BoneWelding® Technology offers new opportunities to anchor implants within bone. The technology melted the surface of biodegradable polymer pins by means of ultrasound energy to mould material into the structures of the predrilled bone. Temperature changes were measured at the sites of implantation in an in vitro experiment. In the in vivo part of the study two types of implants were implanted in the limb of sheep to investigate the biocompatibility of the method. One implant type was made of PL-DL-lactide (PLA), the second one was a titanium core partially covered with PLA. Healing period was 2 and 6 months, with 3 sheep per group. Bone samples were evaluated radiologically, histologically and histomorphometrically for bone remodeling and inflammatory reactions. Results demonstrated mild and short temperature increase during insertion. New bone formed at the implant without evidence of inflammatory reaction. The amount of adjacent bone was increased compared to normal cancellous bone. It was concluded that the BoneWelding® Technology proved to be a biocompatible technology to anchor biodegradable as well as titanium-PLA implants in bone

    The effect of cartilage and bone density of mushroom-shaped, photooxidized, osteochondral transplants: an experimental study on graft performance in sheep using transplants originating from different species

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    BACKGROUND: Differences in overall performance of osteochondral photooxidized grafts were studied in accordance of their species origin and a new, more rigorous cleansing procedure using alcohol during preparation. METHODS: Photooxidized mushroom-shaped grafts of bovine, ovine, human and equine origin were implanted in the femoral condyles of 32 sheep (condyles: n = 64). No viable chondrocytes were present at the time of implantation. Grafts were evaluated at 6 months using plastic embedded sections of non-decalcified bone and cartilage specimens. Graft incorporation, the formation of cyst-like lesions at the base of the cartilage junction as well as cartilage morphology was studied qualitatively, semi-quantitatively using a score system and quantitatively by performing histomorphometrical measurements of percentage of bone and fibrous tissue of the original defects. For statistical analysis a factorial analysis of variance (ANOVA- test) was applied. RESULTS: Differences of graft performance were found according to species origin and cleansing process during graft preparation. According to the score system cartilage surface integrity was best for equine grafts, as well as dislocation or mechanical stability. The equine grafts showed the highest percentage for bone and lowest for fibrous tissue, resp. cystic lesions. The new, more rigorous cleansing process decreased cartilage persistence and overall graft performance. CONCLUSION: Performance of grafts from equine origin was better compared to bovine, ovine and human grafts. The exact reason for this difference was not proven in the current study, but could be related to differences in density of cartilage and subchondral bone between species

    Long term in-vivo studies of a photo-oxidized bovine osteochondral transplant in sheep

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    BACKGROUND: Articular cartilage has limited capacity to repair. Defects greater than 3 mm heal with formation of inferior fibrous cartilage. Therefore, many attempts have been made to find the ideal graft for larger cartilage lesions. Different grafts, such as untreated or cryopreserved osteochondral transplants, have been used with variable success. METHODS: Photo-oxidized osteochondral grafts were implanted in both femoral condyles of one ovine knee. Untreated xenogeneic and autogeneic grafts served as controls. Three groups of 8 sheep each were formed and they were sacrificed 6, 12 or 18 months after surgery. RESULTS: The macroscopic evaluation of the condyle and graft showed a well-maintained cartilage surface in most grafts at all time points. However, the host cartilage matrix deteriorated considerably in all xenogeneic, most autogeneic and fewer of the photo-oxidized grafts at 12 and 18 months, respectively. The blue colour of the photo-oxidized grafts resulting from the process of photo-oxidation was visible in all grafts at 6 months, had diminished at 12 months and had completely disappeared at 18 months after surgery. Histologically a loss of matrix staining was almost never noticed in untreated xenografts, transiently at 6 months in photo-oxidized grafts and increased at 12 and 18 months. Fusion between graft and host cartilage could be seen in photo-oxidized grafts at 12 and 18 months, but was never seen in autografts and xenografts. CONCLUSIONS: The photo-oxidation of osteochondral grafts and its use as transplant appears to have a beneficial effect on cartilage and bone remodelling. Osteochondral grafts pre-treated with photo-oxidation may be considered for articular cartilage replacement and therefore may delay artificial joint replacements in human patients
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