1,205 research outputs found

    Reexamining the monetarist critique of interest rate rules

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    Monetarist economists argued long ago that central bank interest rate rules exacerbate macroeconomic fluctuations, essentially by not allowing the interest rate to respond promptly to shifts in the supply and demand for loans. To support this critique, they pointed to the procyclicality of the money stock. Yet, when there are real shocks and a real business cycle, modern macroeconomic models imply that some procyclicality of money is desirable, to stabilize the price level. A simple interest rate rule illustrates that the monetarist critique can be valid within this model, since the rule exacerbates the response of real activity to real shocks. Other interest rate rules instead limit the macro economy's response to real shocks. But, while these interest rate rules have diverse effects on real activity, there is an important common implication: By smoothing the nominal interest rate in the short run, the rules all lead to increases in the longer-run variability in inflation and nominal interest rates.Interest rates ; Macroeconomics

    Hybrid Low-Order Modeling for Conceptual Vehicle Design

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    Design freedom, and particularly the freedom to incorporate innovative designs and strategies, is greatest at the very beginning of vehicle conceptual design. Conversely, this is when the least knowledge of the product exists. As product content decisions are made the level of freedom in the design decreases and the design becomes locked in. The majority of vehicle lifecycle cost is also set by the end of vehicle conceptual design. This makes it critical to make well-informed and validated decisions in the concept design phase to avoid expensive iterations and redesign in the detailed design phase. Parametric vehicle modeling permits rapid iteration and optimization of vehicles in the conceptual design phase. A significant portion of vehicle design can be optimized parametrically without knowing specific Computer Aided Design (CAD) based details. Many overall vehicle characteristics such as curb mass, center of gravity location, key dimensions, occupant packaging and cargo volume can all be assessed and improved at the parametric level. Key vehicle performance measures can also be determined to a high level of confidence. In developing vehicle dimensions for a parametric model it is recommended to build up a vehicle using an inside-out approach centered on effective, knowledge-based occupant packaging. This work develops a continuum of dimensional parameters which tie vehicle internal and external dimensions together; it employs a combination of industry standard and author-defined component dimensions which make up overall vehicle outside dimensions. An effective continuum of functional parameters is also developed. In order to develop and optimize models for a desired vehicle type and size class, a knowledge base of vehicle typical values for key dimensional parameters has been compiled using a combination of data sources and field measurements. These values provide a useful starting point for the vehicle design optimization process. They also increase optimization effectiveness and ensure that the optimization begins within a valid design space. This work also develops a parametric modeling, scenario builder and optimization software framework which provides a design and optimization tool for vehicle design with trade-off evaluation tools. These parametric design methods improve design maturity prior to beginning vehicle detailed design

    Effects of soft contact lenses as an alternative to topical anesthesia when utilizing the pneuma-tonometer

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    The purpose of this study was two-fold. We attempted to determine if valid intraocular pressure readings could be obtained when utilizing the Digilab Pneuma-tonometer over a soft contact lens in place of an anesthetic on a patient\u27s eye. We also attempted to determine the nature of any difference in patient sensation between utilizing the tonometer with a soft lens versus utilization with a topical corneal anesthetic. Our results indicated that soft lenses allow accurate readings over a range of normal pressures. We also found that no significant difference in sensation existed between the two conditions (contact lens versus anesthetic). We found that utilizing a soft lens during the tonometric procedure was surprisingly uncomplicated, even on inexperienced patients. The results of this study suggest that the technique of utilizing soft lenses with the Pneuma-Tonometer is practical and will yield valid readings over a normal range of pressures

    Sex-Specific Relationships Between Interoceptive Accuracy and Emotion Regulation

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    Over the last years, there has been a resurge in the interest to study the relationship between interoception and emotion. By now, it is well established that interoception contributes to the experience of emotions. However, it may also be possible that interoception contributes to the regulation of emotions. To test this possibility, we studied the relationship between interoception and emotion regulation in a sample of healthy individuals (n = 84). We used a similar heartbeat detection task and a similar self-report questionnaire for the assessment of interoceptive accuracy and emotion regulation as in previous studies. In contrast to previous studies, we differentiated between male and female individuals in our analyses and controlled our analyses for individual characteristics that may affect the relationship between interoceptive accuracy and emotion regulation. We found sex-differences in interoceptive accuracy and emotion regulation that amounted to a sex-specific relationship between interoceptive accuracy and emotion regulation: Whereas interoceptive accuracy was related to reappraisal but not to suppression in male individuals, interoceptive accuracy was unrelated to reappraisal and suppression in female individuals. These findings indicate that the relationship between interoception and emotion regulation is far more complex than has been suggested by previous findings. However, these findings nonetheless support the view that interoception is essential for both, the regulation and experience of emotions

    Einfluss des Lösungsmittels auf die Wirkstoffbeladung von Mikroreservoirs mittels Inkjet-Printing

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    Die Arbeit liefert Erkenntnisse für die Beladung von Reservoirs (Ø 100 µm, Ø 400 µm) mit pharmazeutischen Wirkstoffen mittels Inkjet-Printing. Eine präzise Tropfeneinbringung führt nicht zwangsläufig zu einer präzisen Wirkstoffeinbringung. Während der Lösungsmittelverdunstung treten der Coffee-Ring-Effekt und Creeping auf. Die Ausprägung hängt vom Lösungsmittel ab. Eine leichtflüchtige, ethanolbasierte ASS-Lösung ist stark betroffen, Präzision und Homogenität stark eingeschränkt. Eine sehr schwerflüchtige DMSO-basierte ASS-Lösung ist geringfügig betroffen, Präzision und Homogenität brauchbar

    The Dichotomous Nucleon: Some Radical Conjectures for the Large Nc Limit

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    We discuss some problems with the large Nc approximation for nucleons which arise if the axial coupling of the nucleon to pions is large, g_A \sim Nc. While g_A \sim Nc in non-relativistic quark and Skyrme models, it has been suggested that Skyrmions may collapse to a small size, r \sim 1/f_pi \sim Lambda_QCD^{-1}/sqrt(Nc). (This is also the typical scale over which the string vertex moves in a string vertex model of the baryon.) We concentrate on the case of two flavors, where we suggest that to construct a nucleon with a small axial coupling, that most quarks are bound into colored diquark pairs, which have zero spin and isospin. For odd Nc, this leaves one unpaired quark, which carries the spin and isospin of the nucleon. If the unpaired quark is in a spatial wavefunction orthogonal to the wavefunctions of the scalar diquarks, then up to logarithms of Nc, the unpaired quark only costs an energy \sim Lambda_QCD. This naturally gives g_A \sim 1 and has other attractive features. In nature, the wavefunctions of the paired and unpaired quarks might only be approximately orthogonal; then g_A depends weakly upon Nc. This dichotomy in wave functions could arise if the unpaired quark orbits at a size which is parametrically large in comparison to that of the diquarks. We discuss possible tests of these ideas from numerical simulations on the lattice, for two flavors and three and five colors; the extension of our ideas to more than three or more flavors is not obvious, though.Comment: Published version in Nucl. Phys.

    Low-Load Unilateral and Bilateral Resistance Training to Restore Lower Limb Function in the Early Rehabilitation After Total Knee Arthroplasty: A Randomized Active-Controlled Clinical Trial

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    Background: Continuous passive motion (CPM) is frequently used during rehabilitation following total knee arthroplasty (TKA). Low-load resistance training (LLRT) using continuous active motion (CAM) devices is a promising alternative. We investigated the effectiveness of CPM compared to LLRT using the affected leg (CAMuni) and both legs (CAMbi) in the early post-operative rehabilitation. Hypotheses: (I) LLRT (CAMuni and CAMbi) is superior to CPM, (II) additional training of the unaffected leg (CAMbi) is more effective than unilateral training (CAMuni).Materials and Methods: Eighty-five TKA patients were randomly assigned to three groups, respectively: (i) unilateral CPM of the operated leg; (ii) unilateral CAM of the operated leg (CAMuni); (iii) bilateral alternating CAM (CAMbi). Patients were assessed 1 day before TKA (pre-test), 1 day before discharge (post-test), and 3 months post-operatively (follow-up). Primary outcome: active knee flexion range of motion (ROMFlex). Secondary outcomes: active knee extension ROM (ROMExt), swelling, pain, C-reactive protein, quality of life (Qol), physical activity, timed-up-and-go performance, stair-climbing performance, quadriceps muscle strength. Analyses of covariances were performed (modified intention-to-treat and per-protocol).Results: Hypothesis I: Primary outcome: CAMbi resulted in a higher ROMFlex of 9.0° (95%CI −18.03–0.04°, d = 0.76) and 6.3° (95%CI −14.31–0.99°, d = 0.61) compared to CPM at post-test and follow-up, respectively. Secondary outcomes: At post-test, C-reactive protein was lower in both CAM groups compared with CPM. Knee pain was lower in CAMuni compared to CPM. Improved ROMExt, reduced swelling, better stair-climbing and timed-up-and-go performance were observed for CAMbi compared to CPM. At follow-up, both CAM groups reported higher Qol and CAMbi showed a better timed-up-and-go performance. Hypothesis II: Primary outcome: CAMbi resulted in a higher knee ROMFlex of 6.5° (95%CI −2.16–15.21°, d = 0.56) compared to CAMuni at post-test. Secondary outcomes: At post-test, improved ROMExt, reduced swelling, and better timed-up-and-go performance were observed in CAMbi compared to CAMuni.Conclusions: Additional LLRT of the unaffected leg (CAMbi) seems to be more effective for recovery of function than training of the affected leg only (CAMuni), which may be mediated by positive transfer effects from the unaffected to the affected limb (cross education) and/or preserved neuromuscular function of the trained, unaffected leg.Trial Registration:ClinicalTrials.gov Identifier: NCT02062138

    Novel Missense Mutation A789V in IQSEC2 underlies X-Linked intellectual disability in the MRX78 family

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    Disease gene discovery in neurodevelopmental disorders, including X-linked intellectual disability (XLID) has recently been accelerated by next-generation DNA sequencing approaches. To date, more than 100 human X chromosome genes involved in neuronal signaling pathways and networks implicated in cognitive function have been identified. Despite these advances, the mutations underlying disease in a large number of XLID families remained unresolved. We report the resolution of MRX78, a large family with six affected males and seven affected females, showing X-linked inheritance. Although a previous linkage study had mapped the locus to the short arm of chromosome X (Xp11.4-p11.23), this region contained too many candidate genes to be analyzed using conventional approaches. However, our X-chromosome exome resequencing, bioinformatics analysis and inheritance testing revealed a missense mutation (c.C2366T, p.A789V) in IQSEC2, encoding a neuronal GDP-GTP exchange factor for Arf family GTPases (ArfGEF) previously implicated in XLID. Molecular modeling of IQSEC2 revealed that the A789V substitution results in the insertion of a larger side-chain into a hydrophobic pocket in the catalytic Sec7 domain of IQSEC2. The A789V change is predicted to result in numerous clashes with adjacent amino acids and disruption of local folding of the Sec7 domain. Consistent with this finding, functional assays revealed that recombinant IQSEC2A789V was not able to catalyze GDP-GTP exchange on Arf6 as efficiently as wild-type IQSEC2. Taken together, these results strongly suggest that the A789V mutation in IQSEC2 is the underlying cause of XLID in the MRX78 family

    Observation of an Excited Bc+ State

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    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

    Measurement of the inelastic pp cross-section at a centre-of-mass energy of 13TeV

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    The cross-section for inelastic proton-proton collisions at a centre-of-mass energy of 13TeV is measured with the LHCb detector. The fiducial cross-section for inelastic interactions producing at least one prompt long-lived charged particle with momentum p > 2 GeV/c in the pseudorapidity range 2 < η < 5 is determined to be ϭ acc = 62:2 ± 0:2 ± 2:5mb. The first uncertainty is the intrinsic systematic uncertainty of the measurement, the second is due to the uncertainty on the integrated luminosity. The statistical uncertainty is negligible. Extrapolation to full phase space yields the total inelastic proton-proton cross-section ϭ inel = 75:4 ± 3:0 ± 4:5mb, where the first uncertainty is experimental and the second due to the extrapolation. An updated value of the inelastic cross-section at a centre-of-mass energy of 7TeV is also reported
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