1,552 research outputs found

    Design to reliability shielded vertical interconnection applied to microwave Chip Scale Packaging

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    This paper presents the electrical design, measurement and reliability ests of a shielded vertical interconnection dedicated to microwave solder-mount packages. Electromagnetic simulations show very good results up to 20 GHz. Test samples have been designed and manufactured. Electrical results are in accordance with the simulations with insertion loss lower than 0.1 dB up to 20 GHz for the proposed interconnection. Reliability tests of present no degradation of the after 500 thermal cycles in the [-55°C, +125°C] temperature range

    Fixing DNA breaks during class switch recombination

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    Immunoglobulin (Ig) class switch recombination (CSR) involves the breakage and subsequent repair of two DNA sequences, known as switch (S) regions, which flank IgH constant region exons. The resolution of CSR-associated breaks is thought to require the nonhomologous end-joining (NHEJ) DNA repair pathway, but the role of the NHEJ factor DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in this process has been unclear. A new study, in which broken IgH-containing chromosomes in switching B cells were visualized directly, clearly demonstrated that DNA-PKcs and, unexpectedly, the nuclease Artemis are involved in the resolution of switch breaks

    Investigating (sequential) unit asking: an unsuccessful quest for scope sensitivity in willingness to donate judgments

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    People exhibit scope insensitivity: Their expressed valuation of a problem is not proportionate with its scope or size. To address scope insensitivity in charitable giving, Hsee et al. (2013) developed the (Classical) Unit Asking technique, where people are first asked how much they are willing to donate to support a single individual, followed by how much they are willing to donate to support a group of individuals. In this paper, we explored the mechanisms, extensions, and limitations of the technique. In particular, we investigated an extension of the technique, which we call Sequential Unit Asking (SUA). SUA asks people a series of willingness-to-donate questions, in which the number of individuals to be helped increases in a stepwise manner until it reaches the total group size. Across four studies investigating donation judgments (total (Formula presented.)), we did not find evidence that willingness to donate (WTD) judgments to the total group increased with larger groups. Instead, our results suggest that Unit Asking (sequential or classical) increases donation amounts only through a single one-off boost. Further, we find evidence in three out of four studies that the SUA extension increases WTD judgments over Classical Unit Asking. In a fifth study ((Formula presented.)) using a contingent valuation design (instead of donation judgments), we find scope sensitivity using all asking techniques. We conclude that, while it is difficult to create scope sensitivity in WTD judgments, SUA should be considered a promising approach to increase charitable donations

    Dual-energy X-ray absorptiometry scans accurately predict differing body fat content in live sheep

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    Background There is considerable interest in implementing mobile scanning technology for on-farm body composition analysis on live animals. These experiments evaluated the use of dual energy X-ray absorptiometry (DXA) as an accurate method of total body fat measurement in live sheep. Results In Exp. 1, visceral and whole body fat analysis was undertaken in sheep with body condition scores (BCS) in the range 2 to 3.25 (scale 1: thin to 5: fat). The relationship of BCS was moderately correlated with visceral fat depot mass (r = 0.59, P  0.05, n = 9). There was a moderate correlation between DXA body fat and BCS (r = 0.70, P < 0.01, n = 17), and DXA body fat was highly correlated with chemical body fat (r = 0.81, P < 0.001, n = 9). In Exp. 3, a series of five DXA scans, at 8-week intervals, was performed on growing sheep over a 32-week period. The average BCS ranged from 2.39 ± 0.07 (S.E.M.) to 3.05 ± 0.11 and the DXA body fat (%) ranged from 16.8 ± 0.8 to 24.2 ± 1.2. There was a moderate correlation between DXA body fat and BCS over the 32 weeks (r = 0.61, P < 0.001, n = 24). Conclusions Overall, these experiments indicated that there was good agreement between BCS, DXA and chemical analysis for measuring total body fat in sheep, and that DXA scanning is a valid method for longitudinal measurement of total body fat in live sheep

    Viscoelastic Phase Separation in Shear Flow

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    We numerically investigate viscoelastic phase separation in polymer solutions under shear using a time-dependent Ginzburg-Landau model. The gross variables in our model are the polymer volume fraction and a conformation tensor. The latter represents chain deformations and relaxes slowly on the rheological time giving rise to a large viscoelastic stress. The polymer and the solvent obey two-fluid dynamics in which the viscoelastic stress acts asymmetrically on the polymer and, as a result, the stress and the diffusion are dynamically coupled. Below the coexistence curve, interfaces appear with increasing the quench depth and the solvent regions act as a lubricant. In these cases the composition heterogeneity causes more enhanced viscoelastic heterogeneity and the macroscopic stress is decreased at fixed applied shear rate. We find steady two-phase states composed of the polymer-rich and solvent-rich regions, where the characteristic domain size is inversely proportional to the average shear stress for various shear rates. The deviatoric stress components exhibit large temporal fluctuations. The normal stress difference can take negative values transiently at weak shear.Comment: 16pages, 16figures, to be published in Phys.Rev.

    Orange emission in Pr3+-doped fluoroindate glasses

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    We synthesize and study the properties of praseodymium doped fluoroindate glasses. Glass compositions with praseodymium molar concentrations up to 5% were obtained with good optical quality. Thermal, optical, and luminescence properties are investigated. Judd–Ofelt analysis is used to determine radiative lifetime and emission cross-section of the orange transition originating from the 3P0 level. We find that these glasses are good candidates for the realization of blue diode laser pumped orange lasers for quantum information processing applications

    Focusing light through a free-form scattering medium

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    Imaging and transport light through scattering opaque media is a hot topic pursued in multiple fields, ranging from nanotechnology to life sciences. A promising technique to do this is wavefront shaping (WFS), where the light propagation through a scattering medium is controlled by interference [1][2]. Recently, the potential of WFS was even extended to, for instance, time-varying samples [3][4]. In most cases to date, WFS has been done on the quintessential scattering sample geometry, namely in slabs. Real-world applications, however, require samples to have any shape – “free-form scattering optics” – that defies current theories. Here, we present the study of an opaque sample of TiO2 particles suspended in silicone. Exploiting the flexibility of silicone, we are able to modify the geometry of the sample and measure the enhancement of the intensity η in a point of the speckle pattern. Using this opportunity, we compare the performance of a flat and a free form sample. These experimental measurements will be compared with a newly formulated theory of light transport in free form scattering media

    Remarks on the Causality, Unitarity and Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

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    The gauge-invariant Chern-Simons-type Lorentz- and CPT-breaking term is here re-assessed and issues like causality, unitarity, spontaneous gauge-symmetry breaking are investigated. Moreover, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses.Comment: 5 pages, NPB style, talk presented at "Renormalization Group and Anomalies in Gravity and Cosmology", Ouro Preto, Brazil, March 200

    An appropriate verbal probability lexicon for communicating surgical risks is unlikely to exist

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    Effective risk communication about medical procedures is critical to ethical shared decision-making. Here, we explore the potential for development of an evidence-based lexicon for verbal communication of surgical risk. We found that Ear, Nose and Throat (ENT) surgeons expressed a preference for communicating such risks using verbal probability expressions (VPEs; e.g., “high risk”). However, there was considerable heterogeneity in the expressions they reported using (Study 1). Study 2 compared ENT surgeons’ and laypeople’s (i.e., potential patients) interpretations of the ten most frequent VPEs listed in Study 1. While both groups displayed considerable variability in interpretations, lay participants demonstrated more, as well as providing systematically higher interpretations than those of surgeons. Study 3 found that lay participants were typically unable to provide unique VPEs to differentiate between the ranges of (low) probabilities required. Taken together, these results add to arguments that reliance on VPEs for surgical risk communication is ill-advised. Not only are there systematic interpretational differences between surgeons and potential patients, but the coarse granularity of VPEs raises severe challenges for developing an appropriate evidence-based lexicon for surgical risk communication. We caution against the use of VPEs in any risk context characterized by low, but very different, probabilities. (PsycInfo Database Record (c) 2022 APA, all rights reserved
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