1,657 research outputs found

    Modeling team knowledge sharing and team flexibility : the role of within-team competition

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    This study examines the role of within-team competition (i.e. team hypercompetition and team development competition) in a team process. We developed and tested a model that associates team collectivism as the antecedent of within-team competition, and knowledge sharing and team flexibility as the outcomes. The model was empirically tested with data from 141 knowledge-intensive teams. The empirical findings showed that team collectivism had a positive relationship with team development competition and a negative relationship with team hypercompetition. Regarding the outcomes, team development competition and team hypercompetition had an indirect relationship with knowledge sharing and team flexibility through team empowerment. We offer a number of original contributions to the team effectiveness literature, especially by showing that team hypercompetition and team development competition have different impacts on team knowledge sharing and team flexibility

    Modelling leadership and team performance: the moderation of politics and leadership self-efficacy

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    [[abstract]]This study develops a research model that explains the development of team performance based on team reflexivity theory and social cognitive theory. In the model, team performance relates to considerate leadership and autocratic leadership indirectly via the mediation of team reflexivity. At the same time, politics and leadership self-efficacy are hypothesised as moderators in the model. Primary and secondary data were used via a two-wave investigation from three different sources for verifying our hypotheses. The team-level analyses show that team reflexivity mediates the positive relationship between considerate leadership and team performance. Politics positively moderates the relationship between autocratic leadership and team reflexivity. Leadership self-efficacy positively moderates the relationships between autocratic leadership and team reflexivity and between considerate leadership and team reflexivity. Finally, research implications based on our empirical results are discussed.[[notice]]補正完

    Effect of non-lattice oxygen on ZrO2-based resistive switching memory

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    ZrO2-based resistive switching memory has attracted much attention according to its possible application in the next-generation nonvolatile memory. The Al/ZrO2/Pt resistive switching memory with bipolar resistive switching behavior is revealed in this work. The thickness of the ZrO2 film is only 20 nm. The device yield improved by the non-lattice oxygen existing in the ZrO2 film deposited at room temperature is firstly proposed. The stable resistive switching behavior and the long retention time with a large current ratio are also observed. Furthermore, it is demonstrated that the resistive switching mechanism agrees with the formation and rupture of a conductive filament in the ZrO2 film. In addition, the Al/ZrO2/Pt resistive switching memory is also possible for application in flexible electronic equipment because it can be fully fabricated at room temperature

    The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation.

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    Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation

    Spatiotemporal dynamics of termite infestation in urban Araucaria cunninghamii: A case study in Taipei

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    Termite feeding on the trunk cross-sections of Araucaria cunninghamii in Taipei, Taiwan, was examined using 2D stress wave imaging (FAKOPP system). Six inspections were conducted at 2-month intervals to monitor six trees. 2D cross-sectional stress wave velocity images were created at different heights (30–180 cm) to assess termite feeding damage. Termite damage, quantified as damage ratio (DR, %), ranged from 0% to 55% across different trees and heights, with maximum increases of up to 21% in DR observed over a 2-month period. In the investigated cases, termites primarily fed on the interior of tree trunks. The feeding pattern typically extended longitudinally, then proceeded in a tangential (circular) direction, and finally moved radially. This study identified Coptotermes formosanus as a key termite species involved. Typically, termites prioritized feeding on the earlywood over the latewood. The periods with the highest damage to trunk cross-sections due to termite feeding occurred during seasons with higher temperatures and relative humidity. Damage initially appeared near the heartwood or the boundary between the heartwood and sapwood, gradually expanding into the heartwood. Of the six trees monitored for the full study duration (after one tree was felled for validation), subterranean termite tunneling was observed as the primary pattern in three trees, while aerial swarm invasion patterns were inferred for two trees based on initial damage locations

    A long non-coding RNA protects the heart from pathological hypertrophy

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    The role of long noncoding RNA (lncRNA) in adult hearts is unknownalso unclear is how lncRNA modulates nucleosome remodeling. An estimated 70% of mouse genes undergo antisense transcription, including myosin heavy chain 7 (Myh7) that encodes molecular motor proteins for heart contraction. Here, we identify a cluster of lncRNA transcripts from Myh7 loci and show a new lncRNA–chromatin mechanism for heart failure. In mice, these transcripts, which we named Myosin Heavy Chain Associated RNA Transcripts (MyHEART or Mhrt), are cardiac-specific and abundant in adult hearts. Pathological stress activates the Brg1-Hdac-Parp chromatin repressor complex to inhibit Mhrt transcription in the heart. Such stress-induced Mhrt repression is essential for cardiomyopathy to develop: restoring Mhrt to the pre-stress level protects the heart from hypertrophy and failure. Mhrt antagonizes the function of Brg1, a chromatin-remodeling factor that is activated by stress to trigger aberrant gene expression and cardiac myopathy. Mhrt prevents Brg1 from recognizing its genomic DNA targets, thus inhibiting chromatin targeting and gene regulation by Brg1. Mhrt binds to the helicase domain of Brg1, and this domain is crucial for tethering Brg1 to chromatinized DNA targets. Brg1 helicase has dual nucleic acid-binding specificities: it is capable of binding lncRNA (Mhrt) and chromatinized—but not naked—DNA. This dual-binding feature of helicase enables a competitive inhibition mechanism by which Mhrt sequesters Brg1 from its genomic DNA targets to prevent chromatin remodeling. A Mhrt-Brg1 feedback circuit is thus crucial for heart function. Human MHRT also originates from MYH7 loci and is repressed in various types of myopathic hearts, suggesting a conserved lncRNA mechanism in human cardiomyopathy. Our studies identify the first cardioprotective lncRNA, define a new targeting mechanism for ATP-dependent chromatin-remodeling factors, and establish a new paradigm for lncRNA–chromatin interaction

    Modeling Knowledge Sharing and Interemployee Helping From a Perspective of Flow Theory: A Survey of Online Knowledge Works

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    This study proposes a model based on flow theory by postulating key antecedents as the critical drivers of knowledge sharing and interemployee helping. In the model, knowledge sharing is influenced by flow experience directly and also indirectly via the mediation of interemployee helping. Accordingly, the flow experience is influenced simultaneously by four exogenous factors related to individuals’ perception about their work: work skills, self-fulfillment in challenges, perceived control, and vividness. The empirical findings of this study confirm the applicability of flow theory in business organizations by investigating online knowledge workers from business organizations. This study contributes to the knowledge management literature by extending flow theory to the area of knowledge sharing and interemployee helping, by validating idiosyncratic antecedent drivers of the flow theory, and by performing a practical operationalization of the flow experience. This research also provides managerial implications and limitations

    KCNN2 polymorphisms and cardiac tachyarrhythmias

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    Potassium calcium-activated channel subfamily N member 2 (KCNN2) encodes an integral membrane protein that forms small-conductance calcium-activated potassium (SK) channels. Recent studies in animal models show that SK channels are important in atrial and ventricular repolarization and arrhythmogenesis. However, the importance of SK channels in human arrhythmia remains unclear. The purpose of the present study was to test the association between genetic polymorphism of the SK2 channel and the occurrence of cardiac tachyarrhythmias in humans. We enrolled 327 Han Chinese, including 72 with clinically significant ventricular tachyarrhythmias (VTa) who had a history of aborted sudden cardiac death (SCD) or unexplained syncope, 98 with a history of atrial fibrillation (AF), and 144 normal controls. We genotyped 12 representative tag single nucleotide polymorphisms (SNPs) across a 141-kb genetic region containing the KCNN2 gene; these captured the full haplotype information. The rs13184658 and rs10076582 variants of KCNN2 were associated with VTa in both the additive and dominant models (odds ratio [OR] 2.89, 95% confidence interval [CI] = 1.505-5.545, P = 0.001; and OR 2.55, 95% CI = 1.428-4.566, P = 0.002, respectively). After adjustment for potential risk factors, the association remained significant. The population attributable risks of these 2 variants of VTa were 17.3% and 10.6%, respectively. One variant (rs13184658) showed weak but significant association with AF in a dominant model (OR 1.91, CI = 1.025-3.570], P = 0.042). There was a significant association between the KCNN2 variants and clinically significant VTa. These findings suggest an association between KCNN2 and VTa; it also appears that KCNN2 variants may be adjunctive markers for risk stratification in patients susceptible to SCD

    Waterproofed Photomultiplier Tube Assemblies for the Daya Bay Reactor Neutrino Experiment

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    In the Daya Bay Reactor Neutrino Experiment 960 20-cm-diameter waterproof photomultiplier tubes are used to instrument three water pools as Cherenkov detectors for detecting cosmic-ray muons. Of these 960 photomultiplier tubes, 341 are recycled from the MACRO experiment. A systematic program was undertaken to refurbish them as waterproof assemblies. In the context of passing the water leakage check, a success rate better than 97% was achieved. Details of the design, fabrication, testing, operation, and performance of these waterproofed photomultiplier-tube assemblies are presented.Comment: 16 pages, 11 figures. Submitted to Nucl. Instr. Met

    Small conductance calcium-activated potassium current is important in transmural repolarization of failing human ventricles

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    BACKGROUND: The transmural distribution of apamin-sensitive small conductance Ca(2+)-activated K(+) (SK) current (IKAS) in failing human ventricles remains unclear. METHODS AND RESULTS: We optically mapped left ventricular wedge preparations from 12 failing native hearts and 2 rejected cardiac allografts explanted during transplant surgery. We determined transmural action potential duration (APD) before and after 100 nmol/L apamin administration in all wedges and after sequential administration of apamin, chromanol, and E4031 in 4 wedges. Apamin prolonged APD from 363 ms (95% confidence interval [CI], 341-385) to 409 (95% CI, 385-434; P<0.001) in all hearts, and reduced the transmural conduction velocity from 36 cm/s (95% CI, 30-42) to 32 cm/s (95% CI, 27-37; P=0.001) in 12 native failing hearts at 1000 ms pacing cycle length (PCL). The percent APD prolongation is negatively correlated with baseline APD and positively correlated with PCL. Only 1 wedge had M-cell islands. The percentages of APD prolongation in the last 4 hearts at 2000 ms PCL after apamin, chromanol, and E4031 were 9.1% (95% CI, 3.9-14.2), 17.3% (95% CI, 3.1-31.5), and 35.9% (95% CI, 15.7-56.1), respectively. Immunohistochemical staining of subtype 2 of SK protein showed increased expression in intercalated discs of myocytes. CONCLUSIONS: SK current is important in the transmural repolarization in failing human ventricles. The magnitude of IKAS is positively correlated with the PCL, but negatively correlated with APD when PCL is fixed. There is abundant subtype 2 of SK protein in the intercalated discs of myocytes
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