211 research outputs found

    Female preferences for single and combined traits in computer animated stickleback males

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    In many animal species, males have more than one secondary sexual character. Apart from theoretical considerations about the evolution of multiple traits, there are almost no empirical studies on female mate choice decisions based on combinations of traits as opposed to decisions based on single traits. Because three-spined sticklebacks are exceptionally well suited to be tested with computer animation technique, which itself fills the gap of adequate test paradigms for multiple traits, we tested female sticklebacks for their preferences for both single and combined male traits. We used virtual stickleback males that differed either in red throat coloration, courtship intensity, body size, or in combinations of these traits. The virtual male with increased redness was found to be preferred by females, whereas the male courting more intensely was not. The tests for combinations of traits revealed the more pronounced female preferences, the more traits were available to the females to judge male qualit

    Probing bacterial-fungal interactions at the single cell level.

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    Interactions between fungi and prokaryotes are abundant in many ecological systems. A wide variety of biomolecules regulate such interactions and many of them have found medicinal or biotechnological applications. However, studying a fungal-bacterial system at a cellular level is technically challenging. New microfluidic devices provided a platform for microscopic studies and for long-term, time-lapse experiments. Application of these novel tools revealed insights into the dynamic interactions between the basidiomycete Coprinopsis cinerea and the bacterium Bacillus subtilis. Direct contact was mediated by polar attachment of bacteria to only a subset of fungal hyphae suggesting a differential competence of fungal hyphae and thus differentiation of hyphae within a mycelium. The fungicidal activity of B. subtilis was monitored at a cellular level and showed a novel mode of action on fungal hyphae

    The infectious propagules of Aspergillus fumigatus are coated with antimicrobial peptides

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    Fungal spores are unique cells that mediate dispersal and survival in the environment. For pathogenic fungi encountering a susceptible host, these specialised structures may serve as infectious particles. The main causative agent of the opportunistic disease aspergillosis, Aspergillus fumigatus, produces asexual spores, the conidia, that become dissipated by air flows or water currents but also serve as propagules to infect a susceptible host. We demonstrate that the defX gene of this mould encodes putative antimicrobial peptides resembling cysteine‐stabilised (CS)αβ_{αβ} defensins that are expressed in a specific spatial and temporal manner in the course of asexual spore formation. Localisation studies on strains expressing a fluorescent proxy or tagged defX alleles expose that these antimicrobial peptides are secreted to coat the conidial surface. Deletion mutants reveal that the spore‐associated defX gene products delay the growth of Gram‐positive Staphylococcus aureus and demonstrate that the defX gene and presumably its encoded spore‐associated defensins confer a growth advantage to the fungal opponent over bacterial competitors. These findings have implications with respect to the ecological niche of A. fumigatus that serves as a ‘virulence school’ for this human pathogenic mould; further relevance is given for the infectious process resulting in aspergillosis, considering competition with the host microbiome or co‐infecting microorganisms to break colonisation resistance at host surfaces

    Combining microfluidics and RNA-sequencing to assess the inducible defensome of a mushroom against nematodes

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    Background Fungi are an attractive source of nutrients for predators. As part of their defense, some fungi are able to induce the production of anti-predator protein toxins in response to predation. A previous study on the interaction of the model mushroom Coprinopsis cinerea by the fungivorous nematode Aphelenchus avenae on agar plates has shown that the this fungal defense response is most pronounced in the part of the mycelium that is in direct contact with the nematode. Hence, we hypothesized that, for a comprehensive characterization of this defense response, an experimental setup that maximizes the zone of direct interaction between the fungal mycelium and the nematode, was needed. Results In this study, we conducted a transcriptome analysis of C. cinerea vegetative mycelium upon challenge with A. avenae using a tailor-made microfluidic device. The device was designed such that the interaction between the fungus and the nematode was confined to a specific area and that the mycelium could be retrieved from this area for analysis. We took samples from the confrontation area after different time periods and extracted and sequenced the poly(A)+ RNA thereof. The identification of 1229 differentially expressed genes (DEGs) shows that this setup profoundly improved sensitivity over co-cultivation on agar plates where only 37 DEGs had been identified. The product of one of the most highly upregulated genes shows structural homology to bacterial pore-forming toxins, and revealed strong toxicity to various bacterivorous nematodes. In addition, bacteria associated with the fungivorous nematode A. avenae were profiled with 16S rRNA deep sequencing. Similar to the bacterivorous and plant-feeding nematodes, Proteobacteria and Bacteroidetes were the most dominant phyla in A. avenae. Conclusions The use of a novel experimental setup for the investigation of the defense response of a fungal mycelium to predation by fungivorous nematodes resulted in the identification of a comprehensive set of DEGs and the discovery of a novel type of fungal defense protein against nematodes. The bacteria found to be associated with the fungivorous nematode are a possible explanation for the induction of some antibacterial defense proteins upon nematode challenge

    Patient and healthcare professional eHealth literacy and needs for systemic sclerosis support: a mixed methods study

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    OBJECTIVES: We engaged patients with systemic sclerosis (SSc) and healthcare professionals to assess electronic health (eHealth) literacy and needs relating to web-based support using internet-based information and communication technologies (ICT). METHODS: We employed an explanatory sequential mixed methods design. First, we conducted a cross-sectional survey in patients (n=101) and professionals (n=47). Next, we conducted three focus groups with patients, family members and professionals (n=17). RESULTS: Of patients, 89.1% used ICT at least weekly for private communication. Patients reported relatively high comprehension of eHealth information ([Formula: see text] =6.7, 95% CI: 6.2 to 7.3, range 1-10), yet were less confident evaluating information reliability ([Formula: see text] =5.8, 95% CI: 5.1 to 6.4) and finding eHealth apps ([Formula: see text] =4.8, 95% CI: 4.2 to 5.4). Patients and professionals reported little experience with web-based self-management support. Focus groups revealed 'considering non-ICT-accessible groups' and 'fitting patients' and professionals' technology' as crucial for acceptability. In relation to understanding/appraising eHealth, participants highlighted that general SSc information is not tailored to individual's disease course. Recommendations included 'providing timely, understandable and safe information' and 'empowering end-users in ICT and health decision-making skills'. Professionals expressed concerns about lacking resources. Patients were concerned about data security and person-centredness. Key eHealth drivers included 'addressing end-user perceptions' and 'putting people at the centre of technology'. CONCLUSIONS: Patients and professionals need education/training to support uptake of eHealth resources. Key elements include guiding patients to timely/reliable information and using eHealth to optimise patient-provider communication. Design that is responsive to end-users' needs and considers individuals with limited eHealth literacy and/or ICT access appears to be critical for acceptability

    Patient Assessment Chronic Illness Care (PACIC) and its associations with quality of life among Swiss patients with systemic sclerosis: a mixed methods study

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    BACKGROUND: The Chronic Care Model (CCM) is a longstanding and widely adopted model guiding chronic illness management. Little is known about how CCM elements are implemented in rare disease care or how patients' care experiences relate to health-related quality of life (HRQoL). We engaged patients living with systemic sclerosis (SSc) to assess current care according to the CCM from the patient perspective and their HRQoL. METHODS: We employed an explanatory sequential mixed methods design. First, we conducted a cross-sectional quantitative survey (n = 101) using the Patient Assessment of Chronic Illness Care (PACIC) and Systemic Sclerosis Quality of Life (SScQoL) questionnaires. Next, we used data from individual patient interviews (n = 4) and one patient focus group (n = 4) to further explore care experiences of people living with SSc with a focus on the PACIC dimensions. RESULTS: The mean overall PACIC score was 3.0/5.0 (95% CI 2.8-3.2, n = 100), indicating care was 'never' to 'generally not' aligned with the CCM. Lowest PACIC subscale scores related to 'goal setting/tailoring' (mean = 2.5, 95% CI 2.2-2.7) and 'problem solving/contextual counselling' (mean = 2.9, 95% CI 2.7-3.2). No significant correlations were identified between the mean PACIC and SScQoL scores. Interviews revealed patients frequently encounter major shortcomings in care including 'experiencing organized care with limited participation', 'not knowing which strategies are effective or harmful' and 'feeling left alone with disease and psychosocial consequences'. Patients often responded to challenges by 'dealing with the illness in tailored measure', 'taking over complex coordination of care' and 'relying on an accessible and trustworthy team'. CONCLUSIONS: The low PACIC mean overall score is comparable to findings in patients with common chronic diseases. Key elements of the CCM have yet to be systematically implemented in Swiss SSc management. Identified gaps in care related to lack of shared decision-making, goal-setting and individual counselling-aspects that are essential for supporting patient self-management skills. Furthermore, there appears to be a lack of complex care coordination tailored to individual patient needs

    Bidirectional propagation of signals and nutrients in fungal networks via specialized hyphae

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    Intercellular distribution of nutrients and coordination of responses to internal and external cues via endogenous signaling molecules are hallmarks of multicellular organisms. Vegetative mycelia of multicellular fungi are syncytial networks of interconnected hyphae resulting from hyphal tip growth, branching, and fusion. Such mycelia can reach considerable dimensions and, thus, different parts can be exposed to quite different environmental conditions. Our knowledge about the mechanisms by which fungal mycelia can adjust nutrient gradients or coordinate their defense response to fungivores is scarce, in part due to limitations in technologies currently available for examining different parts of a mycelium over longer time periods at the microscopic level. Here, we combined a tailor-made microfluidic platform with time-lapse fluorescence microscopy to visualize the dynamic response of the vegetative mycelium of a basidiomycete to two different stimuli. The microfluidic platform allows simultaneous monitoring at both the colony and single-hypha level. We followed the dynamics of the distribution of a locally administered nutrient analog and the defense response to spatially confined predation by a fungivorous nematode. Although both responses of the mycelium were constrained locally, we observed long-distance propagation for both the nutrient analog and defense response in a subset of hyphae. This propagation along hyphae occurred in both acropetal and basipetal directions and, intriguingly, the direction was found to alternate every 3 hr in an individual hypha. These results suggest that multicellular fungi have, as of yet, undescribed mechanisms to coordinate the distribution of nutrients and their behavioral response upon attack by fungivores

    Neer Award 2016: reduced muscle degeneration and decreased fatty infiltration after rotator cuff tear in a poly(ADP-ribose) polymerase 1 (PARP-1) knock-out mouse model.

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    BACKGROUND Disturbed muscular architecture, atrophy, and fatty infiltration remain irreversible in chronic rotator cuff tears even after repair. Poly (adenosine 5'-diphosphate-ribose) polymerase 1 (PARP-1) is a key regulator of inflammation, apoptosis, muscle atrophy, muscle regeneration, and adipocyte development. We hypothesized that the absence of PARP-1 would lead to a reduction in damage to the muscle subsequent to combined tenotomy and neurectomy in a PARP-1 knockout (KO) mouse model. METHODS PARP-1 KO and wild-type C57BL/6 (WT group) mice were analyzed at 1, 6, and 12 weeks (total n = 84). In all mice, the supraspinatus and infraspinatus muscles of the left shoulder were detached and denervated. Macroscopic analysis, magnetic resonance imaging, gene expression analysis, immunohistochemistry, and histology were used to assess the differences in PARP-1 KO and WT mice. RESULTS The muscles in the PARP-1 KO group had significantly less retraction, atrophy, and fatty infiltration after 12 weeks than in the WT group. Gene expression of inflammatory, apoptotic, adipogenic, and muscular atrophy genes was significantly decreased in PARP-1 KO mice in the first 6 weeks. DISCUSSION Absence of PARP-1 leads to a reduction in muscular architectural damage, early inflammation, apoptosis, atrophy, and fatty infiltration after combined tenotomy and neurectomy of the rotator cuff muscle. Although the macroscopic reaction to injury is similar in the first 6 weeks, the ability of the muscles to regenerate was much greater in the PARP-1 KO group, leading to a near-normalization of the muscle after 12 weeks

    Uncovering Algebraic Structures in the MPC Landscape

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    A fundamental problem in the theory of secure multi-party computation (MPC) is to characterize functions with more than 2 parties which admit MPC protocols with information-theoretic security against passive corruption. This question has seen little progress since the work of Chor and Ishai (1996), which demonstrated difficulties in resolving it. In this work, we make significant progress towards resolving this question in the important case of aggregating functionalities, in which m parties P1, . . . , Pm hold inputs x1, . . . , xm and an aggregating party P0 must learn f(x1,...,xm). We uncover a rich class of algebraic structures that are closely related to secure computability, namely, “Commuting Permutations Systems” (CPS) and its variants. We present an extensive set of results relating these algebraic structures among themselves and to MPC, including new protocols, impossibility results and separations. Our results include a necessary algebraic condition and slightly stronger sufficient algebraic condition for a function to admit information-theoretically secure MPC protocols. We also introduce and study new models of minimally interactive MPC (called UNIMPC and UNIMPC*), which not only help in understanding our positive and negative results better, but also open up new avenues for studying the cryptographic complexity landscape of multi-party functionalities. Our positive results include novel protocols in these models, which may be of independent practical interest. Finally, we extend our results to a definition that requires UC security as well as semi-honest security (which we term strong security). In this model we are able to carry out the characterization of all computable functions, except for a gap in the case of aggregating functionalities
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