531 research outputs found
Properties of MoNxOy thin films as a function of N/O ratio
The main purpose of this work consists on the preparation of single layered molybdenum oxynitride, MoNxOy. The films were deposited on steel substrates by dc reactive magnetron sputtering. The depositions were carried out from a pure Mo target varying the flow rate of reactive gases, which allowed tune the crystallographic structure between insulating oxides and metallic nitrides and consequently electronic, mechanical and optical properties of the material. X-ray diffraction (XRD) results revealed the occurrence of molybdenum nitride for the films with low oxygen fraction: face-centred cubic phases (gama-Mo2N) for low nitrogen flow rate or cubic MoNx and hexagonal phase (delta-MoN) for high nitrogen flow rate. The increase of oxygen content induces an amorphization of the nitride phases and appearance of MoO3 phases. The increase of the oxygen fraction in the films induces also a high decrease in films hardness. Residual stresses revealed to be of compressive type, in the range of very few tenths of GPa to 2 GPa. All these results have been analysed and will be presented as a function of the deposition parameters, the chemical composition and the structure of the films.Fundação para a Ciência e a Tecnologia (FCT) – Pograma Operacional “Ciência, Tecnologia, Inovação” - POCTI/CTM/38086/2001.Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER)
THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE
Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managers’ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizations’ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research
Analytical Model for the Propagation of Small-Debris-Object Clouds After Fragmentations
AIP4/Itch Regulates Notch Receptor Degradation in the Absence of Ligand
International audienceBACKGROUND:The regulation of Notch signaling heavily relies on ubiquitination events. Drosophila Su(dx), a member of the HECT family of ubiquitin-ligases, has been described as a negative regulator of Notch signaling, acting on the post-endocytic sorting of Notch. The mammalian ortholog of Su(dx), Itch/AIP4, has been shown to have multiple substrates, including Notch, but the precise events regulated by Itch/AIP4 in the Notch pathway have not been identified yet.METHODOLOGY/PRINCIPAL FINDINGS:Using Itch-/- fibroblasts expressing the Notch1 receptor, we show that Itch is not necessary for Notch activation, but rather for controlling the degradation of Notch in the absence of ligand. Itch is indeed required after the early steps of Notch endocytosis to target it to the lysosomes where it is degraded. Furthermore Itch/AIP4 catalyzes Notch polyubiquitination through unusual K29-linked chains. We also demonstrate that although Notch is associated with Itch/AIP4 in cells, their interaction is not detectable in vitro and thus requires either a post-translational modification, or a bridging factor that remains to be identified.CONCLUSIONS/SIGNIFICANCE:Taken together our results identify a specific step of Notch regulation in the absence of any activation and underline differences between mammalian and Drosophila Notch pathways
A relational model of perceived overqualification : the moderating role of interpersonal influence on social acceptance.
Theories of perceived overqualification have tended to focus on employees’ job-related responses to account for effects on performance. We offer an alternative perspective and theorize that perceived overqualification could influence work performance through a relational mechanism. We propose that relational skills, in the form of interpersonal influence of overqualified employees, determine their tendency to experience social acceptance and, thus, engage in positive work-related behaviors. We tested this relational model across two studies using time-lagged, multisource data. In Study 1, the results indicated that for employees high on interpersonal influence, perceived overqualification was positively related to self-reported social acceptance, whereas for employees low on interpersonal influence, the relationship was negative. Social acceptance, in turn, was positively related to in-role job performance, interpersonal altruism, and team member proactivity evaluated by supervisors. In Study 2, we focused on peer-reported social acceptance and found that the indirect relationships between perceived overqualification and supervisor-reported behavioral outcomes via social acceptance were negative when interpersonal influence was low and nonsignificant when interpersonal influence was high. The implications of the general findings are discussed
Heart rate monitoring on the stroke unit. What does heart beat tell about prognosis? An observational study
<p>Abstract</p> <p>Background</p> <p>Guidelines recommend maintaining the heart rate (HR) of acute stroke patients within physiological limits; data on the frequency and predictors of significant deviations from these limits are scarce.</p> <p>Methods</p> <p>Demographical data, stroke risk factors, NIH stroke scale score, lesion size and location, and ECG parameters were prospectively assessed in 256 patients with ischemic stroke. Patients were continuously monitored for at least 24 hours on a certified stroke unit. Tachycardia (HR ≥120 bpm) and bradycardia (HR <45 bpm) and cardiac rhythm (sinus rhythm or atrial fibrillation) were documented. We investigated the influence of risk factors on HR disturbances and their respective influence on dependence (modified Rankin Scale ≥ 3 after three months) and mortality.</p> <p>Results</p> <p>HR ≥120 bpm occurred in 39 patients (15%). Stroke severity (larger lesion size/higher NIHSS-score on admission), atrial fibrillation and HR on admission predicted its occurrence. HR <45 bpm occurred in 12 patients (5%) and was predicted by lower HR on admission. Neither HR ≥120 nor HR <45 bpm independently predicted poor outcome at three moths. Stroke location had no effect on the occurrence of HR violations. Clinical severity and age remained the only consistent predictors of poor outcome.</p> <p>Conclusions</p> <p>Significant tachycardia and bradycardia are frequent phenomena in acute stroke; however they do not independently predict clinical course or outcome. Continuous monitoring allows detecting rhythm disturbances in stroke patients and allows deciding whether urgent medical treatment is necessary.</p
Frequent CEO Turnover and Firm Performance: The Resilience Effect of Workforce Diversity
© 2020, Springer Nature B.V. CEO turnover (or succession) is a critical event in an organization that influences organizational processes and performance. The objective of this study is to investigate whether workforce diversity (i.e., age, gender, and education-level diversity) might have a resilience effect on firm performance under the frequency of CEO turnover. Based on a sample of 409 Korean firms from 2010 to 2015, our results show that firms with more frequent CEO turnover have a lower firm performance. However, firms with more gender and education-level diversity could buffer the disruptive effect of frequent CEO turnover on firm performance to offer a benefit to the organization. Our theory and findings suggest that effectively managing diverse workforce can be a resilience factor in an uncertain organizational environment because diverse workforce has complementary skills and behaviors that can cope better with uncertainty and signals social inclusion of an organization, thus fostering a long-term exchange relationship. These findings contribute to the literature on CEO turnover (or succession) and diversity
Differences in Walking Pattern during 6-Min Walk Test between Patients with COPD and Healthy Subjects
BACKGROUND: To date, detailed analyses of walking patterns using accelerometers during the 6-min walk test (6MWT) have not been performed in patients with chronic obstructive pulmonary disease (COPD). Therefore, it remains unclear whether and to what extent COPD patients have an altered walking pattern during the 6MWT compared to healthy elderly subjects. METHODOLOGY/PRINCIPAL FINDINGS: 79 COPD patients and 24 healthy elderly subjects performed the 6MWT wearing an accelerometer attached to the trunk. The accelerometer features (walking intensity, cadence, and walking variability) and subject characteristics were assessed and compared between groups. Moreover, associations were sought with 6-min walk distance (6MWD) using multiple ordinary least squares (OLS) regression models. COPD patients walked with a significantly lower walking intensity, lower cadence and increased walking variability compared to healthy subjects. Walking intensity and height were the only two significant determinants of 6MWD in healthy subjects, explaining 85% of the variance in 6MWD. In COPD patients also age, cadence, walking variability measures and their interactions were included were significant determinants of 6MWD (total variance in 6MWD explained: 88%). CONCLUSIONS/SIGNIFICANCE: COPD patients have an altered walking pattern during 6MWT compared to healthy subjects. These differences in walking pattern partially explain the lower 6MWD in patients with COPD
Therapeutic potential of cladribine in combination with STAT3 inhibitor against multiple myeloma
<p>Abstract</p> <p>Background</p> <p>Cladribine or 2-chlorodeoxyadenosine (2-CDA) is a well-known purine nucleoside analog with particular activity against lymphoproliferative disorders, such as hairy cell leukemia (HCL). Its benefits in multiple myeloma (MM) remain unclear. Here we report the inhibitory effects of cladribine on MM cell lines (U266, RPMI8226, MM1.S), and its therapeutic potential in combination with a specific inhibitor of the signal transducer and activator of transcription 3 (STAT3).</p> <p>Methods</p> <p>MTS-based proliferation assays were used to determine cell viability in response to cladribine. Cell cycle progression was examined by flow cytometry analysis. Cells undergoing apoptosis were evaluated with Annexin V staining and a specific ELISA to quantitatively measure cytoplasmic histone-associated DNA fragments. Western blot analyses were performed to determine the protein expression levels and activation.</p> <p>Results</p> <p>Cladribine inhibited cell proliferation of MM cells in a dose-dependent manner, although the three MM cell lines exhibited a remarkably different responsiveness to cladribine. The IC50 of cladribine for U266, RPMI8226, or MM1.S cells was approximately 2.43, 0.75, or 0.18 μmol/L, respectively. Treatment with cladribine resulted in a significant G1 arrest in U266 and RPMI8226 cells, but only a minor increase in the G1 phase for MM1.S cells. Apoptosis assays with Annexin V-FITC/PI double staining indicated that cladribine induced apoptosis of U266 cells in a dose-dependent manner. Similar results were obtained with an apoptotic-ELISA showing that cladribine dramatically promoted MM1.S and RPMA8226 cells undergoing apoptosis. On the molecular level, cladribine induced PARP cleavage and activation of caspase-8 and caspase-3. Meanwhile, treatment with cladribine led to a remarkable reduction of the phosphorylated STAT3 (P-STAT3), but had little effect on STAT3 protein levels. The combinations of cladribine and a specific STAT3 inhibitor as compared to either agent alone significantly induced apoptosis in all three MM cell lines.</p> <p>Conclusions</p> <p>Cladribine exhibited inhibitory effects on MM cells <it>in vitro</it>. MM1.S is the only cell line showing significant response to the clinically achievable concentrations of cladribine-induced apoptosis and inactivation of STAT3. Our data suggest that MM patients with the features of MM1.S cells may particularly benefit from cladribine monotherapy, whereas cladribine in combination with STAT3 inhibitor exerts a broader therapeutic potential against MM.</p
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