A LONGITUDINAL STUDY OF IMPRESSION MANAGEMENT STRATEGIES AND LEADERSHIP EMERGENCE: THE MODERATING ROLES OF GENDER AND VIRTUALNESS

This study used a longitudinal study spanning a twelve-week time period and involving 165 undergraduate students to examine the combined impact of gender and impression management strategies on leader emergence by members relying on low versus high virtualness. The subjects were formed into 44 self-managed work groups and charged with completing four deliverables that built on top of each other and were part of their course requirement. The results shows that for individuals relying on low virtualness, there were significant three-way interaction effects between gender, for individuals relying impression management strategies (ingratiation and self-promotion) and time as well as significant two- way interaction effects, regardless of gender, between intimidation and time. For individuals relying on high virtualness, there were significant three-way interaction effects between gender, impression management strategies (ingratiation, self-promotion and exemplification) and time on leader emergence.Slope analysis revealed that women relying on low virtualness faced a backlash in terms of their leader emergence when engaging in high ingratiation, a role-congruent impression management strategy that has been shown to enhance performance evaluations in organizational settings. For these women, high self-promotion, a role-incongruent strategy, also decreased leader emergence over time. In contrast, the leadership emergence for men relying on low virtualness was not impacted by any impression management strategies. Also, the results showed that regardless of gender, for members relying on low virtualness, high intimidation reduced leader emergence over time while low intimidation had the opposite effect. However, intimidation enhanced leader emergence initially.Women relying on high virtualness, on the other hand, did not face a backlash in their leader emergence when they engaged in high ingratiation (a role-congruent strategy) and high self-promotion (a role-incongruent strategy). Instead, for women relying on high virtualness, low ingratiation, self-promotion and exemplification increased their leader emergence over time. Further, regardless of gender, individuals relying on high virtualness did not face any dysfunctional effects on leader emergence over time when they engaged in high supplication or intimidation. In addition, for men relying on high virtualness, ingratiation, exemplification and self-promotion positively influenced leader emergence, regardless of time.In essence, our results demonstrated that the relationship between impression management strategies and leader emergence is influenced by virtualness, time and gender. Women and men need to be wary when engaging in impression management strategies when relying on low virtualness. Further, a text-based setting enables both women and men to engage in impression management strategies without facing backlash effects. For women relying on high virtualness, it would appear that in the long run, they should let their work speak for itself, while for men with a similar disposition, they can still engage in ingratiation, self-promotion and exemplification--in their emerging as leaders

Gender, Media and Leader Emergence: Examining the Impression Management Strategies of Men and Women in Different Settings

This study examined the impact of media (face-to-face versus computer-mediated communication) on the process of leadership emergence by females and males. Specifically, we adapted the literature associated with impression management to investigate whether there are any differences in terms of two key impression management behaviors- self-promotion and supplication- between males and females who emerged as leaders in face-to-face and technology-mediated settings. Our findings challenge conventional gender-related findings. The results indicated that self-promotion plays an important role in influencing leadership emergence while supplication negatively impacts leadership emergence. In a face-to-face context, females who emerged as leaders were found to employ more self-promotion tactics than male leaders while female leaders and male leaders did not differ with respect to the amount of supplication tactics used. Females who emerged as leaders in a face-to-face context were also found to engage in greater self-promotion and more supplication tactics than females who emerged as leaders in a CmC context. Interestingly, there was no significant impact of media on the extent of self-promotion and supplication strategies displayed by male leaders. Future research avenues and implications are discussed

Observation of First-Order Metal-Insulator Transition without Structural Phase Transition in VO_2

An abrupt first-order metal-insulator transition (MIT) without structural phase transition is first observed by current-voltage measurements and micro-Raman scattering experiments, when a DC electric field is applied to a Mott insulator VO_2 based two-terminal device. An abrupt current jump is measured at a critical electric field. The Raman-shift frequency and the bandwidth of the most predominant Raman-active A_g mode, excited by the electric field, do not change through the abrupt MIT, while, they, excited by temperature, pronouncedly soften and damp (structural MIT), respectively. This structural MIT is found to occur secondarily.Comment: 4 pages, 4 figure

Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties

Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe(2)O(4) MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T(2) relaxivities (r(2)) at 4.7 T and room temperature in the range of 60 to 300 mM(−1)s(−1), depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe(2)O(4) MNPs could be used as initial base cores of MRI T(2) CAs, with almost unique T(2) relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis. PACS: 75.75.Fk, 78.67.Bf, 61.46.D

Pseudoaneurysm of the popliteal artery mimicking tumorous condition

Diagnosing pseudoaneurysms of the popliteal artery is usually straightforward in physical examinations and imaging findings. However, when a pseudoaneurysm shows a soft tissue mass with adjacent osseous change, it can mimic a bone tumor or a soft tissue sarcoma. We present a case of a 65-year-old man who had a pseudoaneurysm of the popliteal artery showing soft tissue mass and insinuating into the intramedullary cavity of the tibia. This presented case emphasizes the importance of considering pseudoaneurysms in the differential diagnosis of an apparent soft tissue mass with pressure erosion in adjacent bone

A Case of a False-Positive Anti-Myeloperoxidase Antibody ELISA in a Patient with Hypothyroidism

We present a case of a false-positive anti-myeloperoxidase (MPO) antibody result on an ELISA in a patient with anti-thyroid microsomal antibody (TMA)-positive hypothyroidism. A 41-year-old woman presented with dyspnea on exertion. The initial evaluation revealed pericardial effusion associated with hypothyroidism. In addition, microscopic hematuria with normal renal function and positive cytoplasmic anti-neutrophil cytoplasmic antibodies (c-ANCA) on immunofluorescent assay were found. In further evaluation, elevated anti-TMA and MPO antibodies by ELISA. While no definite signs of vasculitis were present, the clinical state improved with thyroid hormone replacement and diuretics. Anti-MPO antibody was still positive in the follow-up tests, and microscopic hematuria persisted. On the basis of previous reports that thyroid peroxidase and MPO molecules contain cross-reactive epitopes that are exposed in denaturated molecules, we suggest that in a patient with anti-TMA-positive hypothyroidism, anti-MPO antibody might also be positive on ELISA without clinical signs of vasculitis

Comparative cardiovascular outcomes in type 2 diabetes patients taking dapagliflozin versus empagliflozin: a nationwide population-based cohort study

BACKGROUND: Sodium-glucose co-transporter-2 inhibitors displayed cardiovascular benefits in type 2 diabetes mellitus in previous studies; however, there were some heterogeneities regarding respective cardiovascular outcomes within the class. Furthermore, their efficacies in Asians, females, and those with low cardiovascular risks were under-represented. Thus, we compared the cardiovascular outcomes between new users of dapagliflozin and empagliflozin in a broad range of patients with type 2 diabetes mellitus using a nationwide population-based real-world cohort from Korea. METHODS: Korean National Health Insurance registry data between May 2016 and December 2018 were extracted, and an active-comparator new-user design was applied. The primary outcome was a composite of heart failure (HF)-related events (i.e., hospitalization for HF and HF-related death), myocardial infarction, ischemic stroke, and cardiovascular death. The secondary outcomes were individual components of the primary outcome. RESULTS: A total of 366,031 new users of dapagliflozin or empagliflozin were identified. After 1:1 nearest-neighbor propensity score matching, 72,752 individuals (mean age approximately 56 years, 42% women) from each group were included in the final analysis, with a follow-up of 150,000 ~ person-years. Approximately 40% of the patients included in the study had type 2 diabetes mellitus as their sole cardiovascular risk factor, with no other risk factors. The risk of the primary outcome was not different significantly between dapagliflozin and empagliflozin users (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.855-1.006). The risks of secondary outcomes were also similar, with the exception of the risks of HF-related events (HR 0.84, 95% CI 0.714-0.989) and cardiovascular death (HR 0.76, 95% CI 0.618-0.921), which were significantly lower in the dapagliflozin users. CONCLUSIONS: This large-scale nationwide population-based real-world cohort study revealed no significant difference in composite cardiovascular outcomes between new users of dapagliflozin and empagliflozin. However, dapagliflozin might be associated with lower risks of hospitalization or death due to HF and cardiovascular death than empagliflozin in Asian patients with type 2 diabetes mellitus

Detection of an intermediate during the unfolding process of the dimeric ketosteroid isomerase

AbstractFailure to detect the intermediate in spite of its existence often leads to the conclusion that two-state transition in the unfolding process of the protein can be justified. In contrast to the previous equilibrium unfolding experiment fitted to a two-state model by circular dichroism and fluorescence spectroscopies, an equilibrium unfolding intermediate of a dimeric ketosteroid isomerase (KSI) could be detected by small angle X-ray scattering (SAXS) and analytical ultracentrifugation. The sizes of KSI were determined to be 18.7Å in 0M urea, 17.3Å in 5.2M urea, and 25.1Å in 7M urea by SAXS. The size of KSI in 5.2M urea was significantly decreased compared with those in 0M and 7M urea, suggesting the existence of a compact intermediate. Sedimentation velocity as obtained by ultracentrifugation confirmed that KSI in 5.2M urea is distinctly different from native and fully-unfolded forms. The sizes measured by pulse field gradient nuclear magnetic resonance (NMR) spectroscopy were consistent with those obtained by SAXS. Discrepancy of equilibrium unfolding studies between size measurement methods and optical spectroscopies might be due to the failure in detecting the intermediate by optical spectroscopic methods. Further characterization of the intermediate using 1H NMR spectroscopy and Kratky plot supported the existence of a partially-folded form of KSI which is distinct from those of native and fully-unfolded KSIs. Taken together, our results suggest that the formation of a compact intermediate should precede the association of monomers prior to the dimerization process during the folding of KSI