Publications by authors named "Jeewon Choi"

We isolated three novel strains, S1, S2, and S5, from human oral cavities and identified them as distinct novel species. All these strains are facultatively anaerobic, Gram-stain-positive, and non-flagellated bacteria. Their optimal growth conditions for these strains were observed in Columbia broth (CB) at 37 °C, pH 7.

View Article and Find Full Text PDF

Power assistance on joint torque may not be beneficial to all the related muscles. We investigated the effects of power assistance on torque release during isokinetic elbow flexion. An isokinetic dynamometer system was used to simulate dynamic elbow flexion with power assistance, which altered the exercise conditions of baseline isometric torque (greater and lower) and rotation speed (faster and slower) of the lever arm.

View Article and Find Full Text PDF

This study investigated how different shapes of umbrella handles and grip types influence muscle activation and postural variability under windy conditions. Seventeen adult participants were enrolled in this study, and different handle shapes (cylindrical, ellipsoidal, and triangular prism-shaped), grip types (four- and five-finger grip), and wind strengths were tested. Activation of the forearm and upper arm muscles was recorded using surface electromyography.

View Article and Find Full Text PDF

Background: Prolonged and sustained work posture among computer users is one of the main factors that contributes to musculoskeletal discomfort. Rest-break interventions such as task variation and microbreaks may help prevent muscle fatigue and work-related musculoskeletal disorder.

Objective: We aimed to investigate the effects of task variation and microbreaks at seated and standing workstations on forearm muscle activity, namely extensor digitorum communis, extensor carpi ulnaris, flexor digitorum superficialis, and flexor carpi ulnaris; mouse operation force (vertical compression force); mouse operation parameters; and perceived body discomfort during mouse operation.

View Article and Find Full Text PDF

Three novel bacterial strains, 321, 335, and 353, were isolated from the intestines of Aegosoma sinicum larvae collected from Paju-Si, South Korea. The strains were Gram-negative, obligate aerobe and had rod-shaped cells with a single flagellum. The three strains belonged to the genus Luteibacter in the family Rhodanobacteraceae and shared < 99.

View Article and Find Full Text PDF

This study investigated how sitting and standing working postures affected operation force, upper limb muscle activation, and task performance using different pointing devices. Fifteen male participants completed cursor aiming and dragging tasks using a conventional mouse, a vertical mouse, and a trackball at sitting and standing workstations. A custom-made force plate was used to measure operation forces applied to the pointing devices.

View Article and Find Full Text PDF

A novel bacterium, designated strain JHSY0214, was isolated from the gut of a Korean limpet, . Cells of strain JHSY0214 were Gram-stain-negative, strictly aerobic, yellow-pigmented, non-spore-forming, non-motile and showed a rod-coccus growth cycle. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus , and was most closely related to KCTC 12764 (98.

View Article and Find Full Text PDF

Nontuberculous mycobacterial pulmonary diseases (NTM-PDs) are emerging as global health threats with issues of antibiotic resistance. Accumulating evidence suggests that the gut-lung axis may provide novel candidates for host-directed therapeutics against various infectious diseases. However, little is known about the gut-lung axis in the context of host protective immunity to identify new therapeutics for NTM-PDs.

View Article and Find Full Text PDF

Three aerobic, Gram-negative, and rod-shaped bacterial strains, designated strains G4M1, SM13, and L12M9, were isolated from the gut of Batillaria multiformis, Cellana toreuma, and Patinopecten yessoensis collected from the Yellow Sea in South Korea. All the strains grew optimally at 25°C, in the presence of 2% (w/v) NaCl, and at pH 7. These three strains, which belonged to the genus Polaribacter in the family Flavobacteriaceae, shared < 98.

View Article and Find Full Text PDF

Purpose: Speed control is commonly used to regulate the forces applied by motorised walkers (MW) and there are often situations where the speed targeted deviates from the preferred walking speed of its users, such as when encouraging higher walking speeds and due to safety consideration. This study investigates the effects of different MW's target speeds on the selected walking speeds, force applied, perceived exertion, and gait of MW users during steady-state walking.

Materials And Methods: The spatiotemporal gait parameters and perceived exertion of twenty young healthy participants were measured as they walked at a comfortable, self-selected speed using a MW as it was controlled to target forward speeds of 0.

View Article and Find Full Text PDF

This study assessed the influence of different types of flooring on infants' crawling motion patterns and performance. Each participating infant (range: 8.7-12.

View Article and Find Full Text PDF

A novel Gram-stain-negative, aerobic, rod-shaped bacterium with a single polar flagellum, designated strain 2T18, was isolated from the gut of the freshwater mussel collected in the Republic of Korea. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belonged to the genus . Strain 2T18 formed a monophyletic clade with KCTC 42982, KACC 11706 and KCTC 23839, with sequence similarities of 98.

View Article and Find Full Text PDF

A polyphasic taxonomic approach was used to characterize two novel bacterial strains, designated as HDW11 and HDW19, isolated from intestine samples of the dark diving beetle and the diving beetle , respectively. Both isolates were Gram-stain-positive, facultatively anaerobic and non-motile. Strain HDW11 grew optimally at 30 °C, pH 8 and in the presence of 1% (w/v) NaCl.

View Article and Find Full Text PDF

A polyphasic taxonomic approach was used to characterize three novel bacterial strains, designated as HDW12A, HDW-15B, and HDW15C, isolated from the intestine of fish species Odontobutis interrupta or Siniperca scherzeri. All isolates were obligate aerobic, non-motile bacteria, and grew optimally at 30°C. Phylogenetic analysis based on 16S rRNA sequences revealed that strain HDW12A was a member of the genus Nocardioides, and closely related to Nocardioides allogilvus CFH 30205 (98.

View Article and Find Full Text PDF
Article Synopsis
  • * Phylogenetic analysis showed it belongs to a specific genus with a high sequence similarity (98.5%) to other known strains and an average nucleotide identity of 80.6%.
  • * Strain HDW20 has unique fatty acids, specific respiratory quinones, and distinct components in its cell wall peptidoglycan, leading researchers to propose it as a new species, named sp. nov., with the type strain denoted as HDW20.
View Article and Find Full Text PDF

Hypothalamic neurons including proopiomelanocortin (POMC)-producing neurons regulate body weights. The non-motile primary cilium is a critical sensory organelle on the cell surface. An association between ciliary defects and obesity has been suggested, but the underlying mechanisms are not fully understood.

View Article and Find Full Text PDF

Increasingly, electric motors are being incorporated into wheeled walkers to implement various smart features to better assist their users physically. These modified walkers, known as Smart Walkers, use their electric motors to generate horizontal forces that can be used to reduce the physical load for walking, prevent falls and provide navigation support. However, these forces can also alter gait and may inadvertently increase the exertion of the users.

View Article and Find Full Text PDF

Mechanical assistance on joint movement is generally beneficial; however, its effects on cooperative performance and muscle activity needs to be further explored. This study examined how motor performance and muscle activity are altered when mechanical assistance is provided during isometric force control of ramp-down and hold phases. Thirteen right-handed participants (age: 24.

View Article and Find Full Text PDF

This study investigated motor responses of force release during isometric elbow flexion by comparing effects of different ramp durations and step-down magnitudes. Twelve right-handed participants (age: 23.1 ± 1.

View Article and Find Full Text PDF

Despite the established comorbidity between mood disorders and abnormal eating behaviors, the underlying molecular mechanism and therapeutics remain to be resolved. Here, we show that a spexin-based galanin receptor type 2 agonist (SG2A) simultaneously normalized mood behaviors and body weight in corticosterone pellet-implanted (CORTI) mice, which are underweight and exhibit signs of anhedonia, increased anxiety, and depression. Administration of SG2A into the lateral ventricle produced antidepressive and anxiolytic effects in CORTI mice.

View Article and Find Full Text PDF

Background: In addition to addiction and substance abuse, motivational interviewing (MI) is increasingly being integrated in treating other clinical issues such as mental health problems. Most of the many technological adaptations of MI, however, have focused on delivering the action-oriented treatment, leaving its relational component unexplored or vaguely described. This study intended to design a conversational sequence that considers both technical and relational components of MI for a mental health concern.

View Article and Find Full Text PDF

It was hypothesized that atmospheric pressure changes can induce gas flow in the unsaturated zone to such an extent that the advective flux of organic vapors in unsaturated-zone soil gas can be significant relative to the gas-phase diffusion flux of these organic vapors. To test this hypothesis, a series of field measurements and computer simulations were conducted to simulate and compare diffusion and advection fluxes at a trichloroethene-contaminated field site at Picatinny Arsenal in north-central New Jersey. Moisture content temperature, and soil-gas pressure were measured at multiple depths (including at land surface) and times for three distinct sampling events in August 1996, October 1996, and August 1998.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Notice

Message: fwrite(): Write of 34 bytes failed with errno=28 No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 272

Backtrace:

A PHP Error was encountered

Severity: Warning

Message: session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Filename: Unknown

Line Number: 0

Backtrace: