303 research outputs found

    Mode Selection Rules for Two-Delay Systems: Dynamical Explanation for the Function of the Register Hole on the Clarinet

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    Generally, time-delay systems are regarded as multi-attractor systems. We investigate mode selection rules for two-delay systems considering which oscillation mode is first excited by the Hopf bifurcation with increasing a bifurcation parameter. In particular, we focus on the case that the strength of the short time delay α1 is lower than that of the long time delay α2. In a certain range of α1/α2 in which it is sufficiently small but still not negligible, the third-harmonic mode occupies a particular range of the ratio of the two delay times such that 2 < tR2/tR1 < 4, where tR1 and tR2 denote the short and long delay times, respectively. This is the key for understanding the function of the register hole on the clarinet, which is smaller in radius than the other tone holes, but works well to raise the pitch of first register notes in a wide range more than an octave by a twelfth (19 semitones), i.e., generating third harmonics, when opened. This is confirmed using a simple model of the clarinet with two delays: short and long time delays are regarded as delayed reflections caused by the register hole and the open end of the pipe, respectively. The working range of the register hole roughly corresponds to the particular range of the third-harmonic mode for two-delay systems (2 < tR2/tR1 < 4)

    Peripheral platelet phagocytosis in an extremely low birth weight infant: a case report

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    A 768 g female neonate, born at 25 weeks' gestation, developed sepsis due to methicillin-resistant Staphylococcus epidermidis on day 14. Severe thrombocytopenia was observed, and hemophagocytic macrophages were identified in her peripheral blood smear. Cytokine profiles at the time of onset suggested that an inflammatory cytokine storm had activated lymphocytes and macrophages, leading to platelet phagocytosis. After administration of vancomycin for 14 days and immunoglobulin therapy, she improved without any complications. Considering the results of cytokine profiles, early intervention for infection may have prevented progression to hemophagocytic lymphohistiocytosis and reduced the severity of clinical symptoms

    Denitrification in low oxic environments increases the accumulation of nitrogen oxide intermediates and modulates the evolutionary potential of microbial populations.

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    Denitrification in oxic environments occurs when a microorganism uses nitrogen oxides as terminal electron acceptors even though oxygen is available. While this phenomenon is well-established, its consequences on ecological and evolutionary processes remain poorly understood. We hypothesize here that denitrification in oxic environments can modify the accumulation profiles of nitrogen oxide intermediates with cascading effects on the evolutionary potentials of denitrifying microorganisms. To test this, we performed laboratory experiments with Paracoccus denitrificans and complemented them with individual-based computational modelling. We found that denitrification in low oxic environments significantly increases the accumulation of nitrite and nitric oxide. We further found that the increased accumulation of these intermediates has a negative effect on growth at low pH. Finally, we found that the increased negative effect at low pH increases the number of individuals that contribute to surface-associated growth. This increases the amount of genetic diversity that is preserved from the initial population, thus increasing the number of genetic targets for natural selection to act upon and resulting in higher evolutionary potentials. Together, our data highlight that denitrification in low oxic environments can affect the ecological processes and evolutionary potentials of denitrifying microorganisms by modifying the accumulation of nitrogen oxide intermediates

    Measurement of Doppler effects in a cryogenic buffer-gas cell

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    Buffer-gas cooling is a universal cooling technique for molecules and used for various purposes. One of its ap- plications is using molecules inside a buffer-gas cell for low-temperature spectroscopy. Although a high-intensity signal is expected in the cell, complex molecular dynamics is a drawback for precise spectroscopy. In this study, we performed high-resolution absorption spectroscopy of low -J transitions in the &Atilde;&sup2;Π(0, 0, 0)-˜X&sup2;Σ+(0, 0, 0) band of calcium monohydroxide (CaOH). CaOH molecules were produced by laser ablation in a copper cell and cooled to ∼5 K using helium buffer gas. We probed the Doppler effects in a buffer-gas cell by injecting counterpropagating lasers inside the cell. The time evolutions of the Doppler width and shift were simulated using a dedicated Monte Carlo simulation and compared with data

    Low-J Transitions in A˜2Π(0,0,0)−X˜2Σ+(0,0,0) Band of Buffer-gas-cooled CaOH

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    Calcium monohydroxide radical (CaOH) is receiving an increasing amount of attention from the astrophysics community as it is expected to be present in the atmospheres of hot rocky super-Earth exoplanets as well as interstellar and circumstellar environments. Here, we report the high-resolution laboratory absorption spectroscopy on low-J transitions in A ˜ 2 Π ( 0 , 0 , 0 ) − X ˜ 2 Σ + ( 0 , 0 , 0 ) band of buffer-gas-cooled CaOH. In total, 40 transitions out of the low-J states were assigned, including 27 transitions that have not been reported in previous literature. The determined rotational constants for both ground and excited states are in excellent agreement with previous literature, and the measurement uncertainty for the absolute transition frequencies was improved by more than a factor of 3. This will aid future interstellar, circumstellar, and atmospheric identifications of CaOH. The buffer-gas-cooling method employed here is a particularly powerful method to probe low-J transitions and is easily applicable to other astrophysical molecules.</jats:p

    High-resolution spectroscopy of buffer-gas-cooled phthalocyanine

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    For over five decades, studies in the field of chemical physics and physical chemistry have primarily aimed to understand the quantum properties of molecules. However, high-resolution rovibronic spectroscopy has been limited to relatively small and simple systems because translationally and rotationally cold samples have not been prepared in sufficiently large quantities for large and complex systems. In this study, we present high-resolution rovibronic spectroscopy results for large gas-phase molecules, namely, free-base phthalocyanine (FBPc). The findings suggest that buffer-gas cooling may be effective for large molecules introduced via laser ablation. High-resolution electronic spectroscopy, combined with other experimental and theoretical studies, will be useful in understanding the quantum properties of molecules. These findings also serve as a guide for quantum chemical calculations of large molecules

    A Young Man with Anti-NMDAR Encephalitis following Guillain-Barré Syndrome

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    A 19-year-old man developed rapidly progressive muscle weakness and dysesthesia in the extremities, and dyspnea after a flu-like episode. Nerve conduction studies showed reduced motor nerve conduction velocities with conduction block, and sensory nerve action potentials could not be evoked. The patient was diagnosed as having Guillain-Barré syndrome (GBS), and was treated with 2 cycles of intravenous immunoglobulin (IVIg) therapy and was assisted by mechanical ventilation. During the recovery course of the illness, he experienced several attacks of psychomotor agitation from the 37th hospital day, and generalized tonic convulsive seizures suddenly developed on the 42nd hospital day. Brain MRI showed high-intensity lesions in the bilateral thalamus and medial temporal lobes. The convulsions were controlled by continuous thiopental infusion (until the 50th hospital day) and mechanical ventilation (until the 84th hospital day). Intravenous methylprednisolone pulse therapy (1,000 mg/day) for 3 days followed by dexamethasone (16 mg/day) was added. After relief of convulsive seizures, prominent orolingual dyskinesia appeared, and on MRI marked atrophy of the bilateral medial temporal lobes was seen. Anti-N-methyl-D-aspartate receptor (NMDAR) antibodies in serum and cerebrospinal fluid were positive on the 92nd hospital day. Anti-NMDAR encephalitis usually affects young females but a small number of male cases with this disease have been reported. Our male patient was unique in having GBS, a post-infectious autoimmune disease, as a preceding disease, suggesting that anti-NMDAR encephalitis itself is caused by a parainfectious autoimmune mechanism

    The Role of Teachers in the Development of Play Using Grasses and Flowers in a Kindergarten Class for 4-year-olds

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     本論は,幼稚園4歳児学級における草花を使った遊びにおいて,教師の役割を整理し,考察するものである。幼児教育では,遊びの展開に伴って,調和的で多様な学びが深化・発展し,遊びや学びは,幼児主体で偶発的に生じているように見える。しかし,遊びの展開や学びの背景には,「幼児の姿を予想した環境構成」「遊び方の変化に合わせた物的環境の整備」「遊びの発展への架け橋」といった教師の役割が見出された。This paper aims to organize and examine the role of teachers in the play using grasses and flowers in a kindergarten class for 4-year-olds. In early childhood education, harmonious and diverse learning deepens and develops alongside the development of play, with play and learning seemingly occurring spontaneously and child-directed. However, the roles of teachers, such as “environmental constitution anticipating the child's presence,” “maintenance of the physical environment in accordance with changes in play,” and “bridging to the development of play,” were identified as underlying the background of the development of play and learning

    Investigation of biomarkers in a rare case of fulminant necrotizing enterocolitis in a preterm infant

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    We encountered a very rare case of fulminant necrotizing enterocolitis (F-NEC) in a preterm male baby. The course of NEC and sepsis in this case was clearly different from the usual course. After onset at 14 days of life, catheter-related bloodstream infection was first assumed, and antibiotics and γ-globulin administration were started. However, 12 hours after onset, the baby's abdominal distension increased remarkably, and his entire abdominal wall turned red to purple. Escherichia coli were isolated from the blood culture, but the catheter tip culture was negative. Exchange transfusion was performed 32 hours after onset, but no significant changes were observed in the baby's general condition, and he died 46 hours after onset. The acute phase reactants of CRP and α1-acid glycoprotein increased, but haptoglobin did not. Although IL-1β and TNFα increased as expected with sepsis, IL-6, IL-8, IL-10, and G-CSF however increased to a greater extent than expected. From the above, we diagnosed the development of intestinal necrosis as a result of widespread intestinal ischemia, and that sepsis was associated with this poor condition
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