1,095 research outputs found

    Generalized (m,k)-Zipf law for fractional Brownian motion-like time series with or without effect of an additional linear trend

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    We have translated fractional Brownian motion (FBM) signals into a text based on two ''letters'', as if the signal fluctuations correspond to a constant stepsize random walk. We have applied the Zipf method to extract the ζ′\zeta ' exponent relating the word frequency and its rank on a log-log plot. We have studied the variation of the Zipf exponent(s) giving the relationship between the frequency of occurrence of words of length m<8m<8 made of such two letters: ζ′\zeta ' is varying as a power law in terms of mm. We have also searched how the ζ′\zeta ' exponent of the Zipf law is influenced by a linear trend and the resulting effect of its slope. We can distinguish finite size effects, and results depending whether the starting FBM is persistent or not, i.e. depending on the FBM Hurst exponent HH. It seems then numerically proven that the Zipf exponent of a persistent signal is more influenced by the trend than that of an antipersistent signal. It appears that the conjectured law ζ′=∣2H−1∣\zeta ' = |2H-1| only holds near H=0.5H=0.5. We have also introduced considerations based on the notion of a {\it time dependent Zipf law} along the signal.Comment: 24 pages, 12 figures; to appear in Int. J. Modern Phys

    Spiels Petroleumsmaskine.

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    Spiels Petroleumsmaskine

    Evidence-based organizational change and development: is evidence-based OCD a reality or mere rhetoric?

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    ©2020 The Authors. Published in International Journal of HRD Practice, Policy & Research. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://en.calameo.com/read/006426985bb96f8ce61e6This article discusses the compelling need for, and demonstrates, the significant practical 'reality' of evidence-based organizational change and development (EBOCD). It offers a summary of a previously conducted analysis that resulted in 10 validated 'original' and 10 'new' emergent common 'insights' and 'lessons learned' on the effective formulation and implementation of OCD initiatives. These were deduced from 'critical perspectives' and 'reflective case histories' of EBOCD practice offered by over 70 evidence-based organizational leaders/managers, HRD professionals and change management consultants. The article concludes with several recommendations for those engaged in OCD change agency practic

    Radio frequency electronics on plastic

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    In this paper the recent progress of active high frequency electronics on plastic is discussed. This technology is mechanically flexible, bendable, stretchable and does not need any rigid chips. Indium Gallium Zinc Oxide (IGZO) technology is applied. At 2 V supply and gate length of 0.5 μm, the thin-film transistors (TFTs) yield a measured transit frequency of 138 MHz. Our scalable TFT compact simulation model shows good agreement with measurements. To achieve a sufficiently high yield, TFTs with gate lengths of around 5 μm are used for the circuit design. A Cherry Hopper amplifier with 3.5 MHz bandwidth, 10 dB gain and 5 mW dc power is presented. The fully integrated receiver covering a plastic foil area of 3 × 9 mm2 includes a four stage cascode amplifier, an amplitude detector, a baseband amplifier and a filter. At a dc current of 7.2 mA and a supply of 5 V, a bandwidth of 2 - 20 MHz and a gain beyond 15 dB were measured. Finally, an outlook regarding future advancements of high frequency electronics on plastic is given

    Influences of organizational investments in social capital on service employee commitment and performance

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    a b s t r a c t a r t i c l e i n f o Improving customers&apos; service experiences by identifying ways to develop organizational cultures that better motivate and engage service employees is an important issue for service organizations and a top priority in services research. However, extant services research focuses far more on managing customer relationships than on the dynamics of effectively supporting and developing the service personnel who interact with customers. This study assesses the influence of an organizational human resource developmental initiative on service employees. The authors utilize social capital theory and the theory of reasoned action to propose and test a model that examines relationships between organizational investments in social capital and service employees&apos; work-related attitudes, norms, and behaviors. Results from a field study of 407 customerfacing employees from multiple service organizations suggest that making organizational investments in social capital favorably influences service employees&apos; commitment, job performance, and organizational citizenship behavior

    Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure

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    Temperature dependent extended x-ray absorption fine structure (EXAFS) spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20 - 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence of the pair-distance distribution widths, \sigma(T) was accurately modeled using a correlated-Debye model for the lattice vibrational properties, suggesting Debye-like behavior in this material. We obtain pair- specific correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7 K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the first unambiguous determination of Ga-specific vibrational properties in PuGa alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu bonds. This effect has important implications for lattice stabilization mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres

    Identification of miR-21-5p and miR-210-3p serum levels as biomarkers for patients with papillary renal cell carcinoma: a multicenter analysis

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    BACKGROUND: Expression of circulating serum microRNAs has not been studied in a cohort of patients with papillary renal cell carcinoma (pRCC) so far. We hypothesized that miRNA deregulation in malignant tissue is reflected in serum and could be used for non-invasive diagnosis of pRCC as well as differentiation between type 1 and type 2 pRCC. METHODS: We selected 11 differentially regulated miRNAs from the Cancer Genome Atlas (TCGA) pRCC data set as potential serum validation candidates. Serum miRNA expression was determined by qRT-PCR in a total of 34 pRCC type 1, 33 pRCC type 2 and 33 control subjects of three german high-volume medical centers. RESULTS: Heatmap and principal component analysis showed that miRNA expression did not cluster the samples into distinct sample groups and that miRNA levels did not significantly discriminate healthy individuals from patients with pRCC, nor between patients with type 1 and type 2 pRCC. However, miR-21-5p levels were significantly increased in patients with advanced pRCC (>pT3, and/or pN+ and/or pM+) in comparison to localized pRCC. Moreover, adding the expression of miR-210-3p, which was significantly down-regulated in localized pRCC sera in comparison to healthy sera, additionally increased diagnostic accuracy in our study cohort. CONCLUSIONS: In our multicenter cohort, we were not able to identify a single miRNA serum marker for pRCC including its subclasses. However, our study revealed that miR-21-5p levels were elevated in advanced disease (with added diagnostic accuracy via addition of miR-210-3p expression), proposing these two miRs as potential biomarkers in pRCC

    The Chicken Yolk Sac IgY Receptor, a Mammalian Mannose Receptor Family Member, Transcytoses IgY across Polarized Epithelial Cells

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    In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds
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