752 research outputs found
Machine learning based dimension reduction for a stable modeling of periodic flow phenomena
In designing efficient feedback control laws for fluid flow, the modern
control theory can serve as a powerful tool if the model can be represented by
a linear ordinary differential equation (ODE). However, it is generally
difficult to find such a linear model for strongly nonlinear and
high-dimensional fluid flow phenomena. In this study, we propose an autoencoder
which maps the periodic flow phenomena into a latent dynamics governed by a
linear ODE, referred to as a pseudo-symplectic Linear system Extracting
AutoEncoder (LEAE). In addition to the normal functionality of autoencoder,
pseudo-symplectic LEAE emulates a symplectic time integration scheme so that
the Hamiltonian (i.e., the pseudo-energy) of the latent variables is conserved.
We demonstrate that the stability of the derived ODE is improved by considering
the integration stepping forward and backward at the same time. Here, we
consider the circular cylinder wake at as a typical periodic flow
phenomenon.Comment: 6 pages, 4 figure
Synergistic effects of cardiac resynchronization therapy and Bachmann’s bundle pacing on heart failure with atrial tachyarrhythmias
Cardiac resynchronization therapy (CRT) is electrical resynchronization of the ventricles.
Bachmann’s bundle (BB) pacing is considered to be electrical resynchronization of the atria.
Atrial fibrillation (AF) and congestive heart failure (HF) often coexist in the same patient.
A 69 year-old man who underwent CRT combined with BB pacing for HF and atrial
tachycardias or atrial fibrillation (AF) improved HF symptoms. The combined therapy reduced
the number of admissions and occurrence of atrial tachyarrhythmias. It is possible that
CRT combined with BB pacing could provide synergistic, beneficial effects on symptoms in
patients with HF and AF and hence break a vicious circle
Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells
Fluoride ion batteries are potential “next-generation” electrochemical storage devices that offer high energy density. At present, such batteries are limited to operation at high temperatures because suitable fluoride ion–conducting electrolytes are known only in the solid state. We report a liquid fluoride ion–conducting electrolyte with high ionic conductivity, wide operating voltage, and robust chemical stability based on dry tetraalkylammonium fluoride salts in ether solvents. Pairing this liquid electrolyte with a copper–lanthanum trifluoride (Cu@LaF_3) core-shell cathode, we demonstrate reversible fluorination and defluorination reactions in a fluoride ion electrochemical cell cycled at room temperature. Fluoride ion–mediated electrochemistry offers a pathway toward developing capacities beyond that of lithium ion technology
Flow control by a hybrid use of machine learning and control theory
Flow control has a great potential to contribute to the sustainable society
through mitigation of environmental burden. However, high dimensional and
nonlinear nature of fluid flows poses challenges in designing efficient control
laws. This paper aims to propose a hybrid method (i.e., machine learning and
control theory) for feedback control of fluid flows. We propose a partially
nonlinear linear-system extraction autoencoder (pn-LEAE), which consists of
convolutional neural networks-based autoencoder (CNN-AE) and a custom layer to
extract a low-dimensional latent dynamics. This pn-LEAE basically extracts a
linear dynamical system so that the modern control theory can easily be
applied, but at the same time, it is designed to capture a nonlinear
development of the latent dynamics. We demonstrate the effectiveness of the
linear system extracted by the pn-LEAE, as well as the designed control law's
effectiveness for a flow around a circular cylinder at the Reynolds number of
. This is the first attempt utilizing CNN-AE for
linearization of fluid flows involving transient development to design a
feedback control law.Comment: 13 pages, 12 figure
A glucocorticoid-regulating molecule, Fkbp5, may interact with mitogen-activated protein kinase signaling in the organ of Corti of mice cochleae
FKBP5 is a 51-Da FK506-binding protein and member of the immunophilin family involved in controlling the signaling of glucocorticoid receptor from the cytosol to nucleus. Fkbp5 has previously been shown to be expressed in murine cochlear tissue, including the organ of Corti (i.e., the sensory epithelium of the cochlea). Fkbp5-/- mice as used in this study show hearing loss in the low-frequency (8-kHz) range and click-evoked auditory brainstem response (ABR) threshold compared to wild-type mice. Both Fkbp5-/- and wild-type mice showed hearing loss at all frequencies and click-ABR thresholds at 24 h and 14 days following acoustic overexposure (AO). Tissues of the organ of Corti were subjected to RNA sequencing and KEGG pathway analysis. In Fkbp5-/- mice before AO, the mitogen-activated protein kinase (MAPK) signaling pathway was dysregulated compared to wild-type mice. In wild-type mice at 12 h following AO, the most significantly modulated KEGG pathway was the TNF signaling pathway and major MAPK molecules p38 and Jun were involved in the TNF signaling pathway. In Fkbp5-/- mice at 12 h following AO, the MAPK signaling pathway was dysregulated compared to wild-type mice following AO. In conclusion, Fkbp5 interacts with MAPK signaling in the organ of Corti in mice cochleae
Effects of Protective Measures against COVID-19 on Auditory Communication for People with Hearing Loss
WHO has recommended various measures to combat the COVID-19 pandemic, including mask-wearing and physical distancing. However, these changes impair communication for individuals with hearing loss. We investigated the changes in auditory communication associated with COVID-19 measures in 269 patients (male: 45.7%, female: 54.3%, median age: 54 y.o.). Most patients with hearing loss had difficulty engaging in auditory communication with people wearing masks, especially in noisy surroundings or with physical distanc-ing. These difficulties were noticeable in patients with severe hearing loss. Developing communication support strategies for people with hearing loss is an urgent need while COVID-19 measures are in place
Anaesthesia for a morbidly obese patient with schizophrenia and intellectual disability
We report the case of a morbidly obese woman with schizophrenia and intellectual disability who underwent dental treatment using general anaesthesia. The 38-year-old patient was 156 cm tall and weighed 140 kg, with a body mass index of 57.5 kg.m-2. Her developmental age was less than five or six years. She had been taking several antipsychotic agents, including haloperidol. Tracheal intubation was performed smoothly and anaesthesia was maintained uneventfully using propofol and remifentanil.This case demonstrates that the method of general anaesthesia presented here can be used safely in managing patients with these kinds of disabilities
Identifying vertebral fractures in the Japanese population using the trabecular bone score : a cross-sectional study
Background: The trabecular bone score (TBS) is reported to be an independent predictor of fracture risk in patients with primary or secondary osteoporosis. However, there have been few reports on its use in the Japanese population. This study aimed to investigate the risk factors for vertebral fracture in the Japanese population and to evaluate the usefulness of TBS.
Methods: This cross-sectional study involved 279 patients aged 60–90 years in whom bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). TBS was calculated based on the DXA scans. The presence or absence of vertebral fractures was assessed from T11 to L5. The patients were divided into those with vertebral fractures (VF group, n = 104) and those without vertebral fractures (non-VF group, n = 175).
Results: Of the 104 patients in the VF group, 75 had 1 vertebral fracture and 29 had 2 or more fractures. The mean TBS was 1.28 in the VF group and 1.35 in the non-VF group (p 1.23).
Conclusion: TBS was a significant indicator of vertebral fractures in the Japanese population and might contribute to identifying patients with vertebral fractures, particularly those with osteopenia who need pharmacologic therapy
Bilateral Scleritis and Neutrophilic Dermatosis With Cytogenetic Chromosomal Aberrancy Related to Pyoderma Gangrenosum: A Case Report of a 20-Year Follow-Up
Pyoderma gangrenosum is a non-infectious autoimmune disease with skin plaques and ulcers in the entity of neutrophilic dermatosis and may have a background of myelodysplastic syndromes. This study reported a 20-year follow-up of a patient with pyoderma gangrenosum and scleritis who showed chromosomal aberrancy from the initial phase and later in the course developed thrombocythemia. A 51-year-old man presented with widespread indurated erythematous plaques with scaling and pustules on the forehead, bilateral eyelids, and nasal bridge, in addition to nodular scleritis in the left eye and ulcer formation of the plaques in the lower legs. Skin biopsy revealed massive dermal infiltration mainly with neutrophils in the absence of neutrophilic vasculitis. Suspected of myelodysplastic syndromes, bone marrow biopsy was normal, while chromosomal aberrancy, 46, XY, del (20) (q11q13.3), was detected. In the diagnosis of neutrophilic dermatosis, probably of pyoderma gangrenosum, he began to have oral prednisolone 20 mg daily and colchicine 1 mg daily, leading to the subsidence of skin lesions. Four months later, he developed nodular scleritis in the right eye and began to use topical 0.1% betamethasone in both eyes. He was stable with only prednisolone 12.5 mg daily until the age of 55.5 years, when he showed an increase of serum lactate dehydrogenase. The bone marrow aspirate disclosed neither blast cell increase nor atypical cells. The same chromosomal aberrancy was repeatedly detected. One year later, he developed breathing difficulty and underwent tracheostomy. Laryngeal lesion biopsy disclosed squamous cell papilloma with human papillomavirus-6. At 60 years old, he showed marginal corneal infiltration in the left eye, and at 61 years old, hypopyon in the right eye. Platelets tended to increase up to 1000 × 103/µL, and bone marrow examinations were recommended but refused by the patient. At the latest follow-up at 71 years old, he was ambulatory in health and stable with a tracheostomy cannula. In conclusion, pyoderma gangrenosum with scleritis occurred in an undetermined hematological malignancy with chromosomal aberrancy
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