536 research outputs found
Experimental Performance Evaluation of a MR Brake-Based Haptic System for Teleoperation
In this work, a new type of haptic system inspired by human wrist motion is proposed, and its performance is evaluated experimentally for teleoperation. The master device has 3-DOF rotational motion, which is the same as human wrist motion; semi-active magnetorheological brakes are installed to generate a haptic effect for the operator. To achieve a good haptic feedback effect, the master device is designed with a lightweight structure and the haptic actuator is designed with minimal size. The slave robot has 3-DOF rotational motion using servomotors, a five-bar linkage mechanism, and a pivot point. In the proposed slave robot, instead of a commercial torque sensor, a newly designed torque sensor that uses three force sensors is adopted. It is experimentally validated that the proposed haptic system has good performance in terms of the tracking control of the desired position and repulsive torque. In addition, to ensure that the human operator can actually distinguish the different magnitudes of torque, a simple recognition test is carried out. Although not continuous, it is confirmed that the torque difference can be distinguished at three levels. Finally, it is demonstrated that the proposed haptic system can be effectively applied to a real teleoperation system
Leading With Callings: Effects of Leader’s Calling on Followers’ Team Commitment, Voice Behavior, and Job Performance
Viewing work as a calling has been considered to be beneficial to individuals and organizations. However, research to date has largely focused on the effects of individuals’ own callings on themselves, leaving the effects of one’s calling on others unexplored. Based on research that demonstrates prevalent effects of callings and leader’s influences on followers at work, we assumed that leader calling might have positive effects on followers’ outcomes. Specifically, we hypothesized that the extent to which leaders view their work as a calling have positive influences on followers’ team commitment, leader-rated voice behavior, and job performance. We also examined a mediating effect of transformational leadership on the relations between leader’s calling and the three follower’s outcomes. Using data on 284 leader-follower pairs from the South Korean Air Force, we found that leader’s calling was positively associated with followers’ team commitment, voice behaviors, and job performance. The effects of leader’s calling on follower commitment and voice behavior were partly accounted for by follower perceptions of transformational leadership. However, a mediating role of transformational leadership on the link between leader’s calling and job performance was not supported. The implications of these findings are discussed
A Case of Autoimmune Pancreatitis Manifested by a Pseudocyst and IgG4-Associated Cholangitis
Autoimmune pancreatitis (AIP) is a benign disorder and a unique form of chronic pancreatitis with several characteristic features. A cystic formation that mimics a pseudocyst is a rare finding. There have been a few reports of AIP complicated by pancreatic cysts. We present a case of AIP with multiple pseudocysts and obstructive jaundice caused by IgG4-associated cholangitis. We initially missed the diagnosis due to the pseudocyst. Based on the computed tomography images, laboratory findings and the therapeutic response to steroids, the case was diagnosed as AIP with pseudocysts and associated cholangiopathy
Genetic variation of aldolase from Korean isolates of Plasmodium vivax and its usefulness in serodiagnosis
Background: The malaria aldolase is widely used as rapid diagnostic test (RDT), but the efficacy in aspect of its serological effectiveness in diagnosis is not known. The genetic variation of Korean isolates was analysed and recombinant aldolase was evaluated as a serological antigen in Plasmodium vivax malaria. Methods: Genomic DNA was purified and the aldolase gene of P. vivax from 25 patients’ blood samples was amplified. The samples came from 5 epidemic areas; Bucheon-si, Gimpo-si, Paju-si of Gyeonggido, Gangwha-gun of Incheon metropolitan city, and Cheorwon of Gangwon-do, South Korea. The antigenicity of the recombinant aldolase was tested by western blot and enzyme-linked immunosorbent assay (ELISA). Results: Sequence analysis of 25 Korean isolates of P. vivax showed that the open reading frame (ORF) of 1,110 nucleotides encoded a deduced protein of 369 amino acids (aa). This ORF showed 100% homology with the P. vivax Sal I strain (XM_00165894) and P. vivax WDK strain (AF247063), 87.4% homology with Plasmodium falciparum (AF179421), 90.6% homology with Plasmodium chabaudi (AF247060), 89.5% homology with Plasmodium vinckei (AF247061), and 96.7% homology with Plasmodium knowlesi. A single nucleotide polymorphism (SNP) at nucleotide 180 (G to A, n = 5) was also observed in the isolates. The expressed recombinant protein had a molecular weight of approximately 31 kDa (monomeric form) and 62 kDa (dimeric form) as analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Among 109 P. vivax patients, 32 (29.4%) had positive in an enzyme-linked absorbance assay (ELISA). This result showed significant correlation between ELISA and an indirect fluorescent antibody test (IFAT) (P < 0.0001). Conclusions: The aldolase gene from Korean isolates of P. vivax showed one SNP at nucleotide position 180; this SNP mutant was discovered in only the western part of Han River, and included the regions of Ganghwa, Gimpo, and Bucheon. Based on the results, the relationship between antibody production against aldolase and the pattern of disease onset should be more investigated before using aldolase for serodiagnosis
Recommended from our members
Estimating the malaria transmission of Plasmodium vivax based on serodiagnosis
Background: Plasmodium vivax re-emerged in 1993 and has now become a major public health problem during the summer season in South Korea. The aim of this study was to interpret and understand the meaning of seroepidemiological studies for developing the best malaria control programme in South Korea. Methods: Blood samples were collected in Gimpo city, Paju city, Yeoncheon County, Cheorwon County and Goseong County of high risk area in South Korea. Microscopy was performed to identify patients infected with P. vivax. Antibody detection for P. vivax was performed using indirect fluorescent antibody test (IFAT). Results: A total of 1,574 blood samples was collected from participants in the study areas and evaluated against three parameters: IFAT positive rate, annual antibody positive index (AAPI), and annual parasite index (API). The IFAT positive rate was 7.24% (n = 114). Of the five study areas, Gimpo had the highest IFAT positive rate (13.68%) and AAPI (4.63). Yeongcheon had the highest API in 2005 (2.06) while Gimpo had the highest API in 2006 (5.00). No correlation was observed between any of the three parameters and study sites' distance from the demilitarized zone (DMZ). Conclusions: These results showed that P. vivax antibody levels could provide useful information about the prevalence of malaria in endemic areas. Furthermore, AAPI results for each year showed a closer relationship to API the following year than the API of the same year and thus could be helpful in predicting malaria transmission risks
Could Fractional Exhaled Nitric Oxide Test be Useful in Predicting Inhaled Corticosteroid Responsiveness in Chronic Cough? A Systematic Review
© 2016 Background Fractional exhaled nitric oxide (FENO) is a safe and convenient test for assessing T H 2 airway inflammation, which is potentially useful in the management of patients with chronic cough. Objective To summarize the current evidence on the diagnostic usefulness of FENO for predicting inhaled corticosteroid (ICS) responsiveness in patients with chronic cough. Methods A systematic literature review was conducted to identify articles published in peer-reviewed journals up to February 2015, without language restriction. We included studies that reported the usefulness of FENO (index test) for predicting ICS responsiveness (reference standard) in patients with chronic cough (target condition). The data were extracted to construct a 2 × 2 accuracy table. Study quality was assessed with Quality Assessment of Diagnostic Accuracy Studies 2. Results We identified 5 original studies (2 prospective and 3 retrospective studies). We identified considerable heterogeneities in study design and outcome definitions, and thus were unable to perform a meta-analysis. The proportion of ICS responders ranged from 44% to 59%. Sensitivity and specificity ranged from 53% to 90%, and from 63% to 97%, respectively. The reported area under the curve ranged from abou t 0.60 to 0.87; however, studies with a prospective design and a lower prevalence of asthma had lower area under the curve values. None measured placebo effects or objective cough frequency. Conclusions We did not find strong evidence to support the use of FENO tests for predicting ICS responsiveness in chronic cough. Further studies need to have a randomized, placebo-controlled design, and should use validated measurement tools for cough. Standardization would facilitate the development of clinical evidence
Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer
Magnetic skyrmions have fast evolved from a novelty, as a realization of
topologically protected structure with particle-like character, into a
promising platform for new types of magnetic storage. Significant engineering
progress was achieved with the synthesis of compounds hosting room-temperature
skyrmions in magnetic heterostructures, with the interfacial
Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation.
Here we report findings of ultrathin skyrmion formation in a few layers of
SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer.
Measurement of the topological Hall effect (THE) reveals a robust stability of
skyrmions in this platform, judging from the high value of the critical field
1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as
much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up
to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film
proves the rumpling of the Ru-O plane to be the source of inversion symmetry
breaking and DMI. First-principles calculations based on the structure obtained
from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the
main source of skyrmion robustness. These features promise a few-layer SRO to
be an important new platform for skyrmionics, without the necessity of
introducing the capping layer to boost the spin-orbit coupling strength
artificially.Comment: Supplementary Information available upon reques
Emergence of robust 2D skyrmions in SrRuO3 ultrathin film without the capping layer
Magnetic skyrmions have fast evolved from a novelty, as a realization of
topologically protected structure with particle-like character, into a
promising platform for new types of magnetic storage. Significant engineering
progress was achieved with the synthesis of compounds hosting room-temperature
skyrmions in magnetic heterostructures, with the interfacial
Dzyaloshinskii-Moriya interactions (DMI) conducive to the skyrmion formation.
Here we report findings of ultrathin skyrmion formation in a few layers of
SrRuO3 grown on SrTiO3 substrate without the heavy-metal capping layer.
Measurement of the topological Hall effect (THE) reveals a robust stability of
skyrmions in this platform, judging from the high value of the critical field
1.57 Tesla (T) at low temperature. THE survives as the field is tilted by as
much as 85 degrees at 10 Kelvin, with the in-plane magnetic field reaching up
to 6.5 T. Coherent Bragg Rod Analysis, or COBRA for short, on the same film
proves the rumpling of the Ru-O plane to be the source of inversion symmetry
breaking and DMI. First-principles calculations based on the structure obtained
from COBRA find significant magnetic anisotropy in the SrRuO3 film to be the
main source of skyrmion robustness. These features promise a few-layer SRO to
be an important new platform for skyrmionics, without the necessity of
introducing the capping layer to boost the spin-orbit coupling strength
artificially.Comment: Supplementary Information available upon reques
- …