122 research outputs found

    Worm Grunting, Fiddling, and Charming—Humans Unknowingly Mimic a Predator to Harvest Bait

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    Background: For generations many families in and around Florida’s Apalachicola National Forest have supported themselves by collecting the large endemic earthworms (Diplocardia mississippiensis). This is accomplished by vibrating a wooden stake driven into the soil, a practice called ‘‘worm grunting’’. In response to the vibrations, worms emerge to the surface where thousands can be gathered in a few hours. Why do these earthworms suddenly exit their burrows in response to vibrations, exposing themselves to predation? Principal Findings: Here it is shown that a population of eastern American moles (Scalopus aquaticus) inhabits the area where worms are collected and that earthworms have a pronounced escape response from moles consisting of rapidly exiting their burrows to flee across the soil surface. Recordings of vibrations generated by bait collectors and moles suggest that ‘‘worm grunters’ ’ unknowingly mimic digging moles. An alternative possibility, that worms interpret vibrations as rain and surface to avoid drowning is not supported. Conclusions: Previous investigations have revealed that both wood turtles and herring gulls vibrate the ground to elicit earthworm escapes, indicating that a range of predators may exploit the predator-prey relationship between earthworms and moles. In addition to revealing a novel escape response that may be widespread among soil fauna, the results sho

    On Unbounded Composition Operators in L2L^2-Spaces

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    Fundamental properties of unbounded composition operators in L2L^2-spaces are studied. Characterizations of normal and quasinormal composition operators are provided. Formally normal composition operators are shown to be normal. Composition operators generating Stieltjes moment sequences are completely characterized. The unbounded counterparts of the celebrated Lambert's characterizations of subnormality of bounded composition operators are shown to be false. Various illustrative examples are supplied

    Assessment of Complement Cascade Components in Patients With Bipolar Disorder

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    Introduction: The immune system is undoubtedly involved in the pathogenesis of various psychiatric disorders, such as schizophrenia, bipolar disorder, or depression. Although its role is not fully understood, it appears that this area of research can help to understand the etiology of mental illness. One of the components of the human immune system is the complement system, which forms a part of the innate immune response. Physiologically, except for its essential protective role, it is a vital element in the regeneration processes, including neurogenesis. To date, few studies have tried to clarify the role of the complement cascade in mental disorders.Materials and Methods: We evaluated concentrations of C3a, C5a, and C5b-9 complement cascade components in the peripheral blood of 30 patients suffering from bipolar disorder (BD) for at least 10 years, in euthymia, who were not treated with lithium salts. In addition, we divided our study sample into BD type I (BD-I, 22 persons), and BD type II (BD-II, 8 patients). The control group consisted of 30 healthy volunteers matched for age, sex, BMI, and smoking habits.Results: Compared to healthy controls, BD patients had elevated concentrations of all the investigated components. Furthermore, in patients with BD-II, we observed higher concentrations of C5b-9 as compared to patients with BD-I. However, there was a significant effect of BD diagnosis only on the levels of C3a and C5a but not on the level of C5b-9 after adjustment for potential confounding factors.Conclusions: Increased concentrations of components C3a and C5a of the complement system in the investigated group as compared to healthy controls suggest involvement of the complement cascade in the pathogenesis of BD, and provides further evidence of immune system dysregulation in BD patients

    PET Molecular Targets and Near-Infrared Fluorescence Imaging of Atherosclerosis

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    PURPOSE OF REVIEW: With this review, we aim to summarize the role of positron emission tomography (PET) and near-infrared fluorescence imaging (NIRF) in the detection of atherosclerosis. RECENT FINDINGS: (18)F-FDG is an established measure of increased macrophage activity. However, due to its low specificity, new radiotracers have emerged for more specific detection of vascular inflammation and other high-risk plaque features such as microcalcification and neovascularization. Novel NIRF probes are engineered to sense endothelial damage as an early sign of plaque erosion as well as oxidized low-density lipoprotein (oxLDL) as a prime target for atherosclerosis. Integrated NIRF/OCT (optical coherence tomography) catheters enable to detect stent-associated microthrombi. Novel radiotracers can improve specificity of PET for imaging atherosclerosis. Advanced NIRF probes show promise for future application in human. Intravascular NIRF might play a prominent role in the detection of stent-induced vascular injury

    Overview of the first Wendelstein 7-X long pulse campaign with fully water-cooled plasma facing components

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    after a long device enhancement phase, scientific operation resumed in 2022. The main new device components are the water cooling of all plasma facing components and the new water-cooled high heat flux divertor units. Water cooling allowed for the first long-pulse operation campaign. A maximum discharge length of 8 min was achieved with a total heating energy of 1.3 GJ. Safe divertor operation was demonstrated in attached and detached mode. Stable detachment is readily achieved in some magnetic configurations but requires impurity seeding in configurations with small magnetic pitch angle within the edge islands. Progress was made in the characterization of transport mechanisms across edge magnetic islands: Measurement of the potential distribution and flow pattern reveals that the islands are associated with a strong poloidal drift, which leads to rapid convection of energy and particles from the last closed flux surface into the scrape-off layer. Using the upgraded plasma heating systems, advanced heating scenarios were developed, which provide improved energy confinement comparable to the scenario, in which the record triple product for stellarators was achieved in the previous operation campaign. However, a magnetic configuration-dependent critical heating power limit of the electron cyclotron resonance heating was observed. Exceeding the respective power limit leads to a degradation of the confinement

    System for examination of humidity influence on gas sensors

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    Czujniki gazów są bardzo istotnym elementem wielu instalacji przemysłowych – nie tylko jako elementy bezpośredniej kontroli i obserwacji procesów chemicznych, ale także jako kluczowy komponent systemów bezpieczeństwa. Istotne jest więc zapewnienie odpowiednich parametrów metrologicznych tego typu sensorów, w tym odporności na działanie czynników zewnętrznych. Jednym z czynników mogących silnie wpływać na pomiary stężenia gazu jest jego wilgotność. Niniejszy artykuł przedstawia projekt i konstrukcję urządzenia pozwalającego na regulację wilgotności mieszanek kalibracyjnych gazów, a także jego testy i przeprowadzone z jego pomocą badania czujników katalitycznych i z absorpcją podczerwieni, dowodzące użyteczności zbudowanego prototypu w roli sprzętu laboratoryjnego.Gas sensors are significant elements of many plants in industry. They do not only serve as indicators and elements of control loops in chemical processes, but also are the main part of the safety systems. In many situations a gas sensor is the first line of defence against leakage of dangerous substances. Therefore, ensuring its appropriate metrological parameters is crucial. The fact that sensors should not be sensitive to environmental parameters is very important. Unfortunately, influence of air humidity, which can strongly affect measurements, is difficult to measure. This paper proposes a system for preparation of gas mixtures with specific relative humidity. It allows to examine the reaction of gas sensors to changes of vapour concentration in calibration gases. One of assumptions of this project was low cost of manufacturing the system and simple, modular construction. The design, construction and examination of the device are presented. The exemplary tests of catalytic sensors and infrared sensors are also described. The accuracy and practical utility of the system were proved by results of conducted research
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