10 research outputs found

    Saltmarsh as habitat of Common Redshanks Tringa totanus breeding in the Wadden Sea of Lower Saxony, Germany : useful hideaway or ecological trap?

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    Die Brutbestände des Rotschenkels nehmen in weiten Teilen Europas stark ab, während die des Wattenmeeres stabil sind bzw. lange Zeit waren. Verschiedene Studien legen jedoch nahe, dass die Reproduktion des Rotschenkels im Wattenmeer räumlich stark variiert. Ziel der in den Jahren 2004 bis 2006 durchgeführten telemetrischen Untersuchungen von Küken des Rotschenkels auf der Insel Wangerooge und im Petersgroden am Festland war, erstmalig den Bruterfolg dieser Art zu beziffern, die bisher vorläufige Einschätzung einer räumlich stark variierenden Reproduktion zu verifizieren sowie Modelle künftiger Bestandsverläufe zu entwerfen. Aufgrund geringerer Gelege-Prädation erzielten die Vögel auf Wangerooge einen sehr viel höheren Schlupferfolg (2005/06: 64 bzw. 93 % der Gelege) als im Petersgroden (2004 bis 2006: 4 bis 15 %). Abgesehen von witterungsbedingten Totalverlusten im Jahre 2004 am Festland, lag die Mortalität nicht-flügger Küken in beiden Gebieten bei 70-80 %. Der Bruterfolg in den Jahren 2005 und 2006 wird auf 0,51 bzw. 1,0 Küken pro Brutpaar auf Wangerooge und auf konstant 0,15 Küken/Brutpaar am Festland geschätzt. Bei bisherigen Schätzungen (Literaturwerte) jährlicher Mortalitätsraten von 35 (Subadulte) bzw. 25 % (Adulte) wären diese Bruterfolge bei Weitem nicht ausreichend, um den untersuchten Festlandsbestand langfristig zu erhalten. Auf Wangerooge dagegen würden zumindest zeitweise mehr Jungvögel produziert als für die Erhaltung des regionalen Bestandes notwendig sind. Die bisherige Annahme einer räumlich variierenden Reproduktion von Rotschenkeln im Wattenmeer konnte mit diesen Ergebnissen bestätigt werden. Ob die gefundenen Bruterfolge zur Erklärung der gegenwärtigen Bestandsdynamik des Rotschenkels im Wattenmeer ausreichen, bleibt allerdings weiterhin fraglich. Die Notwendigkeit eines integrierten Populationsmonitorings wird vor diesem Hintergrund diskutiert. Die nicht-flüggen Küken waren in beiden Untersuchungsgebieten sehr ortstreu. Sie entfernten sich in den ersten Lebenswochen durchschnittlich maximal knapp 200 m vom ursprünglichen Neststandort und nutzten dabei eine Fläche von durchschnittlich etwa 0,4 ha. Die Raumnutzung von Rotschenkel-Familien legt nahe, dass der Bruterfolg der Vögel auch nach dem Schlupf der Küken noch potentiell stark durch die landwirtschaftliche Nutzung gefährdet ist, insbesondere durch Mahd. Die hier vorgelegte Untersuchung unterstreicht die Vermutung, dass landwirtschaftliche Nutzung ein ungeeignetes Mittel des Habitatmanagements für Brutvögel der Salzrasen darstellt.In contrast to most other European breeding sites, the breeding population of the Redshank Tringa totanus in the European Wadden Sea is stable in most areas of the ecosystem. As suggested by recent studies on hatching success, however, Redshank reproduction is spatially variable and cannot reliably explain the population trend mentioned above. From 2004 to 2006, a telemetry study on Redshank chicks was conducted in Petersgroden (mainland) and on the island of Wangerooge to record annual breeding success and its spatial variability and to derive predictions on future population trends. Due to lower predation, birds on Wangerooge achieved considerably higher hatching success than birds at the mainland (2005/06: 64 and 93 % of clutches vs. 4 to 15 %, 2004-2005). Apart from total losses due to weather conditions in 2004 at the mainland, chick mortality was relatively constant between regions and years (70-80 %). Derived from chick mortality, breeding success was 0.51 (2005) and 1.0 (2006) chicks per pair on Wangerooge and constantly 0.15 chicks per pair at the mainland. Considering published estimates of annual subadult (35 %) and adult (25 %) mortality, breeding success achieved during this study should not be sufficient to maintain the regional population of the mainland study site. In contrast, the Wangerooge population produced more chicks than needed to sustain its local population. The assumption of spatially varying reproduction of Redshanks breeding in the Wadden Sea could be confirmed by this study. However, it still has to be clarified whether Redshank population dynamics is explained by this varying breeding success. Due to a lack of knowledge in annual survival rates, the necessity of initiating an integrated population monitoring project is discussed. As additionally revealed by chick telemetry, non-fledged chicks were found up to only about 200 m from its former nest site and used about 0.4 ha of the respective saltmarsh habitat. Small home range sizes of Redshank broods within the saltmarsh suggest a potential vulnerability to agricultural habitat management, especially to mowing. Derived from these results, it is unlikely that agriculture is an appropriate way of managing saltmarsh for breeding birds

    Teledermatology: Comparison of Store-and-Forward Versus Live Interactive Video Conferencing

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    A decreasing number of dermatologists and an increasing number of patients in Western countries have led to a relative lack of clinicians providing expert dermatologic care. This, in turn, has prolonged wait times for patients to be examined, putting them at risk. Store-and-forward teledermatology improves patient access to dermatologists through asynchronous consultations, reducing wait times to obtain a consultation. However, live video conferencing as a synchronous service is also frequently used by practitioners because it allows immediate interaction between patient and physician. This raises the question of which of the two approaches is superior in terms of quality of care and convenience. There are pros and cons for each in terms of technical requirements and features. This viewpoint compares the two techniques based on a literature review and a clinical perspective to help dermatologists assess the value of teledermatology and determine which techniques would be valuable in their practice

    A skin cancer prevention facial-aging mobile app for secondary schools in Brazil : appearance-focused interventional study.

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    Background: The incidence of melanoma is increasing faster than any other major cancer both in Brazil and worldwide. Southeast Brazil has especially high incidences of melanoma, and early detection is low. Exposure to ultraviolet (UV) radiation is a primary risk factor for developing melanoma. Increasing attractiveness is a major motivation among adolescents for tanning. A medical student-delivered intervention that takes advantage of the broad availability of mobile phones and adolescents? interest in their appearance indicated effectiveness in a recent study from Germany. However, the effect in a high-UV index country with a high melanoma prevalence and the capability of medical students to implement such an intervention remain unknown. Objective: In this pilot study, our objective was to investigate the preliminary success and implementability of a photoaging intervention to prevent skin cancer in Brazilian adolescents. Methods: We implemented a free photoaging mobile phone app (Sunface) in 15 secondary school classes in southeast Brazil. Medical students ?mirrored? the pupils? altered 3-dimensional (3D) selfies reacting to touch on tablets via a projector in front of their whole grade accompanied by a brief discussion of means of UV protection. An anonymous questionnaire capturing sociodemographic data and risk factors for melanoma measured the perceptions of the intervention on 5-point Likert scales among 356 pupils of both sexes (13-19 years old; median age 16 years) in grades 8 to 12 of 2 secondary schools in Brazil. Results: We measured more than 90% agreement in both items that measured motivation to reduce UV exposure and only 5.6% disagreement: 322 (90.5%) agreed or strongly agreed that their 3D selfie motivated them to avoid using a tanning bed, and 321 (90.2%) that it motivated them to improve their sun protection; 20 pupils (5.6%) disagreed with both items. The perceived effect on motivation was higher in female pupils in both tanning bed avoidance (n=198, 92.6% agreement in females vs n=123, 87.2% agreement in males) and increased use of sun protection (n=197, 92.1% agreement in females vs n=123, 87.2% agreement in males) and independent of age or skin type. All medical students involved filled in a process evaluation revealing that they all perceived the intervention as effective and unproblematic, and that all pupils tried the app in their presence. Conclusions: The photoaging intervention was effective in changing behavioral predictors for UV protection in Brazilian adolescents. The predictors measured indicated an even higher prospective effectiveness in southeast Brazil than in Germany (>90% agreement in Brazil vs >60% agreement in Germany to both items that measured motivation to reduce UV exposure) in accordance with the theory of planned behavior. Medical students are capable of complete implementation. A randomized controlled trial measuring prospective effects in Brazil is planned as a result of this study

    Laser-manufactured mirrors for geometrical output coupling of intracavity-generated high harmonics

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    We demonstrate micro structuring of fused-silica laser mirror substrates by Inverse Laser Drilling. Slits of a width down to ~80 µm and circular holes with diameters down to ~50 µm have been structured into quarter-inch thick substrates. Except for chipping, the surface areas around these openings have not been irreversibly affected by the manufacturing process. The micro structured mirrors can be used for geometrical output coupling of coherent EUV radiation from cavity-enhanced high harmonic generation

    Teledermatology: Comparison of Store-and-Forward Versus Live Interactive Video Conferencing

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    A decreasing number of dermatologists and an increasing number of patients in Western countries have led to a relative lack of clinicians providing expert dermatologic care. This, in turn, has prolonged wait times for patients to be examined, putting them at risk. Store-and-forward teledermatology improves patient access to dermatologists through asynchronous consultations, reducing wait times to obtain a consultation. However, live video conferencing as a synchronous service is also frequently used by practitioners because it allows immediate interaction between patient and physician. This raises the question of which of the two approaches is superior in terms of quality of care and convenience. There are pros and cons for each in terms of technical requirements and features. This viewpoint compares the two techniques based on a literature review and a clinical perspective to help dermatologists assess the value of teledermatology and determine which techniques would be valuable in their practice

    Lack of astrocytes hinders parenchymal oligodendrocyte precursor cells from reaching a myelinating state in osmolyte-induced demyelination

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    Demyelinated lesions in human pons observed after osmotic shifts in serum have been referred to as central pontine myelinolysis (CPM). Astrocytic damage, which is prominent in neuroinflammatory diseases like neuromyelitis optica (NMO) and multiple sclerosis (MS), is considered the primary event during formation of CPM lesions. Although more data on the effects of astrocyte-derived factors on oligodendrocyte precursor cells (OPCs) and remyelination are emerging, still little is known about remyelination of lesions with primary astrocytic loss. In autopsy tissue from patients with CPM as well as in an experimental model, we were able to characterize OPC activation and differentiation. Injections of the thymidine-analogue BrdU traced the maturation of OPCs activated in early astrocyte-depleted lesions. We observed rapid activation of the parenchymal NG
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