74 research outputs found

    Warming increases the compositional and functional variability of a temperate protist community

    Get PDF
    Phototrophic protists are a fundamental component of the world's oceans by serving as the primary source of energy, oxygen, and organic nutrients for the entire ecosystem. Due to the high thermal seasonality of their habitat, temperate protists could harbour many well-adapted species that tolerate ocean warming. However, these species may not sustain ecosystem functions equally well. To address these uncertainties, we conducted a 30-day mesocosm experiment to investigate how moderate (12C) and substantial (18C) warming compared to ambient conditions (6C) affect the composition (18S rRNA metabarcoding) and ecosystem functions (biomass, gross oxygen productivity, nutritional quality – C:N and C:P ratio) of a North Sea spring bloom community. Our results revealed warming-driven shifts in dominant protist groups, with haptophytes thriving at 12 C and diatoms at 18 C. Species responses primarily depended on the species' thermal traits, with indirect temperature effects on grazing being less relevant and phosphorus acting as a critical modulator. The species Phaeocystis globosa showed highest biomass on low phosphate concentrations and relatively increased in some replicates of both warming treatments. In line with this, the C:P ratio varied more with the presence of P. globosa than with temperature. Examining further ecosystem responses under warming, our study revealed lowered gross oxygen productivity but increased biomass accumulation whereas the C:N ratio remained unaltered. Although North Sea species exhibited resilience to elevated temperatures, a diminished functional similarity and heightened compositional variability indicate potential ecosystem repercussions for higher trophic levels. In conclusion, our research stresses the multifaceted nature of temperature effects on protist communities, emphasising the need for a holistic understanding that encompasses trait-based responses, indirect effects, and functional dynamics in the face of exacerbating temperature changes

    A multimodal imaging approach enables in vivo assessment of antifungal treatment in a mouse model of invasive pulmonary aspergillosis

    Get PDF
    Aspergillus fumigatus causes life-threatening lung infections in immunocompromised patients. Mouse models are extensively used in research to assess the in vivo efficacy of antifungals. In recent years, there has been an increasing interest in the use of non-invasive imaging techniques to evaluate experimental infections. However, single imaging modalities have limitations concerning the type of information they can provide. In this study, magnetic resonance imaging and bioluminescence imaging were combined to obtain longitudinal information on the extent of developing lesions and fungal load in a leucopenic mouse model of IPA. This multimodal imaging approach was used to assess changes occurring within lungs of infected mice receiving voriconazole treatment starting at different time points after infection. Results showed that IPA development depends on the inoculum size used to infect animals and that disease can be successfully prevented or treated by initiating intervention during early stages of infection. Furthermore, we demonstrated that reduction of the fungal load is not necessarily associated with the disappearance of lesions on anatomical lung images, especially when antifungal treatment coincides with immune recovery. In conclusion, multimodal imaging allows to investigate different aspects of disease progression or recovery by providing complementary information on dynamic processes, which are highly useful for assessing the efficacy of (novel) therapeutic compounds in a time- and labor-efficient manner

    German S3 guideline "actinic keratosis and cutaneous squamous cell carcinoma" – long version of the update 2023

    Get PDF
    Actinic keratosis (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline “actinic keratosis and cutaneous squamous cell carcinoma” was updated and expanded by the topics cutanepus squamous cell carcinoma in situ (Bowen’s disease) and actinic cheilitis. This guideline was developed at the highest evidence level (S3) and is aimed at dermatologists, general practitioners, ear nose and throat specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings, as well as other medical specialties, policy makers and insurance funds involved in the diagnosis and treatment of patients with AK and cSCC

    Diagnostic Performance of a Support Vector Machine for Dermatofluoroscopic Melanoma Recognition: The Results of the Retrospective Clinical Study on 214 Pigmented Skin Lesions

    No full text
    The need for diagnosing malignant melanoma in its earliest stages results in an increasing number of unnecessary excisions. Objective criteria beyond the visual inspection are needed to distinguish between benign and malignant melanocytic tumors in vivo. Fluorescence spectra collected during the prospective, multicenter observational study (“FLIMMA”) were retrospectively analyzed by the newly developed machine learning algorithm. The formalin-fixed paraffin-embedded (FFPE) tissue samples of 214 pigmented skin lesions (PSLs) from 144 patients were examined by two independent pathologists in addition to the first diagnosis from the FLIMMA study, resulting in three histopathological results per sample. The support vector machine classifier was trained on 17,918 fluorescence spectra from 49 lesions labeled as malignant (1) and benign (0) by three histopathologists. A scoring system that scales linearly with the number of the “malignant spectra” was designed to classify the lesion as malignant melanoma (score > 28) or non-melanoma (score ≤ 28). Finally, the scoring algorithm was validated on 165 lesions to ensure model prediction power and to estimate the diagnostic accuracy of dermatofluoroscopy in melanoma detection. The scoring algorithm revealed a sensitivity of 91.7% and a specificity of 83.0% in diagnosing malignant melanoma. Using additionally the image segmentation for normalization of lesions’ region of interest, a further improvement of sensitivity of 95.8% was achieved, with a corresponding specificity of 80.9%

    Cognitive factors mediate placebo responses in patients with house dust mite allergy.

    Get PDF
    BACKGROUND: Placebo effects have been reported in type I allergic reactions. However the neuropsychological mechanisms steering placebo responses in allergies are largely unknown. The study analyzed whether and to what extend a conditioned placebo response is affecting type I allergic reactions and whether this response can be reproduced at multiple occasions. METHODS: 62 patients with house dust mite allergy were randomly allocated to either a conditioned (n = 25), sham-conditioned (n = 25) or natural history (n = 12) group. During the learning phase (acquisition), patients in the conditioned group received the H1-receptor antagonist desloratadine (5mg) (unconditioned stimulus/US) together with a novel tasting gustatory stimulus (conditioned stimulus/CS). Patients in the sham-conditioned control group received the CS together with a placebo pill. After a wash out time of 9 days patients in the conditioned and sham-conditioned group received placebo pills together with the CS during evocation. Allergic responses documented by wheal size after skin prick test and symptom scores after nasal provocation were analyzed at baseline, after last desloratadine treatment and after the 1(st) and 5(th) CS re-exposure. RESULTS: Both conditioned and sham-conditioned patients showed significantly decreased wheal sizes after the 1(st) CS-evocation and significantly decreased symptom scores after the 1(st) as well as after the 5(th) evocation compared to the natural history control group. CONCLUSIONS: These results indicate that placebo responses in type I allergy are not primarily mediated by learning processes, but seemed to be induced by cognitive factors such as patients' expectation, with these effects not restricted to a single evocation
    • 

    corecore