A Multilevel Study Of Supportive Leadership And Individual Work Outcomes: The Mediating Roles Of Team Cooperation, Job Satisfaction, And Team Commitment

Due to increasing empowerment in work teams, team leaders’ supportive role in helping team members perform their tasks is deemed important. The present study aimed at exploring the multilevel dynamics involving team leaders’ supportive leadership and individual work outcomes. Longitudinal survey data were collected from 536 employees in 69 teams of a large engineering company located in South Korea. The results of multilevel structural equation modeling showed that individuals’ perceptions of supportive leadership were positively related to their subsequent task performance, and that this relationship was mediated by team commitment. The relationship between individual-level perceptions of supportive leadership and organizational citizenship behavior (OCB) was mediated by job satisfaction and team commitment. On the other hand, team cooperation mediated the relationship between team-level perceptions of supportive leadership and OCB. These findings provide meaningful insights into multilevel mediation processes involving different levels of supportive leadership perceptions

Self-Serving Bias in Performance Goal Achievement Appraisals: Evidence From Long-Distance Runners

While working with a long-distance running event organizer, the authors of this study observed considerable differences between event participants’ official finish time (i.e., bib time) and their self-reported finish time in the post-event survey. Drawing on the notion of self-serving bias, we aim to explore the source of this disparity and how such psychological bias influences participants’ event experience at long-distance running events. Using evidence of 1,320 marathon runners, we demonstrated how people are more likely to be subject to a biased self-assessment contingent upon achieving their best finish time at the event. The study samples were split into record-high-achieved and record-high-missed groups, and the self-serving biases of each group were explored. Results from the t-test comparing record-high-achieved and -missed groups showed that runners in the record-high-missed group were significantly more likely to report a positively biased finish time than runners in the record-high-achieved group (p \u3c 0.01). Additionally, results from logistic regression showed that as runners missed their best finish time by a wider margin, the probability of reporting a positively biased incorrect finish time increased. Lastly, we conducted an additional t-test and revealed that runners who are subject to self-serving bias showed a lower level of overall event satisfaction. The current study suggests one way to bypass the adverse effects of participant sport event participants’ worse-than-expected athletic performance. We specifically suggest that the event organizers target runners who had worse-than-expected performance and make extra efforts on non-race service attributes (e.g., finish line experience, rest and recovery area, and transportation after the event) because these runners are more likely to be unsatisfied with the event

Self-Isolated Dual-Mode High-Pass Birdcage RF Coil for Proton and Sodium MR Imaging at 7 T MRI

This study presents the feasibility of a dual-mode high-pass birdcage RF coil to acquire MR images at both 1H and 23Na frequencies at ultra-high-field MR scanner, 7 T. A dual-mode circuit (DMC) in the dual-mode birdcage (DMBC) RF coil operates at two frequencies, addressing the limitations of sensitivity reduction and isolation between two frequencies as in traditional dual-tuned RF coil. Finite-difference time-domain (FDTD) based electromagnetic (EM) simulations were performed to verify the RF coil at each frequency on the three-dimensional human head model. The DMBC RF coil resonated at proton (1H) and sodium (23Na) frequencies, and also single-tuned high-pass birdcage RF coils were constructed for both 1H and 23Na frequencies. The bench test performance of the RF coils was evaluated using network analysis parameters, including the measurement of scattering parameters (S-parameters) and quality factors (Q-factors). Q-factor of the DMBC coil at 1H port was 10.2% lower than that of 1H single-tuned birdcage (STBC) coil, with a modest SNR reduction of 6.5%. Similarly, the Q-factor for the DMBC coil at 23Na port was 12.3% less than that of 23Na STBC coil, and the SNR showed a minimal reduction of 5.4%. Utilizing the DMBC coil, promising 1H and 23Na MR images were acquired compared to those by using STBC coils. In conclusion, deploying a DMBC 1H/23Na coil has been demonstrated to overcome traditional constraints associated with dual-tuned RF coils, achieving this with only nominal signal attenuation across both nuclei operational frequencies

Renormalization group theory for percolation in time-varying networks

Motivated by multi-hop communication in unreliable wireless networks, we present a percolation theory for time-varying networks. We develop a renormalization group theory for a prototypical network on a regular grid, where individual links switch stochastically between active and inactive states. The question whether a given source node can communicate with a destination node along paths of active links is equivalent to a percolation problem. Our theory maps the temporal existence of multi-hop paths on an effective two-state Markov process. We show analytically how this Markov process converges towards a memory-less Bernoulli process as the hop distance between source and destination node increases. Our work extends classical percolation theory to the dynamic case and elucidates temporal correlations of message losses. Quantification of temporal correlations has implications for the design of wireless communication and control protocols, e.g. in cyber-physical systems such as self-organized swarms of drones or smart traffic networks.Comment: 8 pages, 3 figure

Stemness Evaluation of Mesenchymal Stem Cells from Placentas According to Developmental Stage: Comparison to Those from Adult Bone Marrow

This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (P<0.001, 31.7±5.8 vs. 15.7±6.2 with group I, 9.2±4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs

A Case of Lambert-Eaton Myasthenic Syndrome Associated with Atypical Bronchopulmonary Carcinoid Tumor

The Lambert-Eaton myasthenic syndrome (LEMS) is typically recognized as a paraneoplastic syndrome associated with a small cell lung carcinoma (SCLC), whereas LEMS with other neuroendocrine lung tumors, including carcinoids or large cell lung carcinoma, are highly unusual. Here, we report a rare case of LEMS with atypical bronchopulmonary carcinoid tumor: A 65-yr-old man presented with progressive leg weakness and a diagnosis of LEMS was made by serial repetitive nerve stimulation test. Chest CT revealed a lung nodule with enlargement of paratracheal lymph nodes, and surgically resected lesion showed pathological features of atypical carcinoid tumor. We concluded that LEMS could be associated with rare pulmonary neuroendocrine tumor other than SCLC, which necessitates pathologic confirmation followed by aggressive treatment for optimal management in these rare cases

OCT using spectrally resolved bandwidth

An apparatus is disclosed for studying an object based on at least one of polarization, space, position or angle of light that has reflected from the object. An optical tomographic instrumentation of the apparatus includes a light source coupled to a source path, a sample path, a reference path, and a detection path, wherein the light source generates a spectrally resolved bandwidth. The spectrally resolved bandwidth includes a plurality of spectrally resolved cells and a detector in the detection path for analyzing light reflected from an object in the sample path and the light reflected in the reference path based upon at least one of the polarization, spatial relationship, position or angle domains.Board of Regents, University of Texas Syste

Obesity and Metabolic Syndrome in Korea

In Korea, a person with a body mass index (BMI) ≥25 kg/m2 is considered obese, and a person with a BMI ≥30 kg/m2 is classified as severely obese. Central obesity is defined as a waist circumference ≥90 cm for Korean men and ≥85 cm for Korean women. Recent epidemiologic data show that the prevalence of severe obesity and metabolic syndrome is steadily increasing. These epidemics increased morbidity and mortality of type 2 diabetes, cardiovascular diseases, and obesity-related cancers such as breast, colorectal, and other cancers in Korea. Decreased physical activity, increased fat and alcohol consumption, heavy smoking, and stress/depressed mood are the primary modifiable life-style risk factors for Koreans. Recently, public health interventions to encourage life-style changes have shown promising results in reducing the prevalence of severe obesity and metabolic syndrome