9,762 research outputs found

    The last common bilaterian ancestor

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    Many regulatory genes appear to be utilized in at least superficially similar ways in the development of particular body parts in Drosophila and in chordates. These similarities have been widely interpreted as functional homologies, producing the conventional view of the last common protostome-deuterostome ancestor (PDA) as a complex organism that possessed some of the same body parts as modern bilaterians. Here we discuss an alternative view, in which the last common PDA had a less complex body plan than is frequently conceived. This reconstruction alters expectations for Neoproterozoic fossil remains that could illustrate the pathways of bilaterian evolution

    Ability of LIGO and LISA to probe the equation of state of the early Universe

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    The expansion history of the Universe between the end of inflation and the onset of radiation-domination (RD) is currently unknown. If the equation of state during this period is stiffer than that of radiation, w>1/3w > 1/3, the gravitational wave (GW) background from inflation acquires a blue-tilt dlogρGWdlogf=2(w1/3)(w+1/3)>0{d\log\rho_{\rm GW}\over d\log f} = {2(w-1/3)\over (w+1/3)} > 0 at frequencies ffRDf \gg f_{\rm RD} corresponding to modes re-entering the horizon during the stiff-domination (SD), where fRDf_{\rm RD} is the frequency today of the horizon scale at the SD-to-RD transition. We characterized in detail the transfer function of the GW energy density spectrum, considering both 'instant' and smooth modelings of the SD-to-RD transition. The shape of the spectrum is controlled by ww, fRDf_{\rm RD}, and HinfH_{\rm inf} (the Hubble scale of inflation). We determined the parameter space compatible with a detection of this signal by LIGO and LISA, including possible changes in the number of relativistic degrees of freedom, and the presence of a tensor tilt. Consistency with upper bounds on stochastic GW backgrounds, however, rules out a significant fraction of the observable parameter space. We find that this renders the signal unobservable by Advanced LIGO, in all cases. The GW background remains detectable by LISA, though only in a small island of parameter space, corresponding to scenarios with an equation of state in the range 0.46w0.560.46 \lesssim w \lesssim 0.56 and a high inflationary scale Hinf1013 GeVH_{\rm inf} \gtrsim 10^{13}~{\rm GeV}, but low reheating temperature 1 MeVTRD150 MeV1~{\rm MeV} \lesssim T_{\rm RD} \lesssim 150~{\rm MeV} (equivalently, 1011 HzfRD3.6109 Hz10^{-11}~{\rm Hz} \lesssim f_{\rm RD} \lesssim 3.6\cdot10^{-9}~{\rm Hz}). Implications for early Universe scenarios resting upon an SD epoch are briefly discussed.Comment: Matching published version in JCAP, 32 pages, 8 figure

    Method of stabilizing flueric vortex valves and vortex amplifiers

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    Inducing losses in the vortex chamber of vortex valves and vortex amplifiers resolves the problem of unstable operation caused by a sufficiently large positive feedback. Induced losses also reduce pressure gain and throttling range of vortex pressure amplifier

    Positional spending and status seeking in rural China

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    Focusing on a remote area in rural China, we use a panel census of households in 26 villages to show that socially observable spending has risen sharply in recent years. We demonstrate that such spending by households is highly sensitive to social spending by other villagers. This suggests that social spending is either positional in nature (that is, motivated by status concerns) or subject to herding behavior. We also document systematic relations between social spending and changes in higher order terms of the income distribution. In particular, and consistent with theories of rank-based status seeking, we find the poor increase spending on gifts as the income distribution tightens so that local competition for status intensifies. In addition families of unmarried men (who face grim marriage prospects given China’s high sex ratios, especially in poor areas) intensify their competition for status by increasing their spending on weddings. The welfare implications of spending in order to “keep up with the Joneses” are potentially large, particularly for poor households.Positional spending, Poverty, Rural-urban linkages, status,

    A piezoelectrically actuated ball valve

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    Bimorph strip composed of two layers of poled piezoelectric ceramic material closes and opens valve. Strip performs like capacitator, allowing initial inrush of current when valve is energized and then only small leakage current flows as valve remains energized

    Analisis Pengukuran Kinerja Menggunakan Metode Balanced Scorecard pada PT.Bahtera Utama

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    This research was conducted in PT.Bahtera Utama by measuring performance using the Balanced Scorecard as measured through four perspectives, that is financial perspective, the customer perspective, internal business process perspective, and learning and growth perspective. The purpose of this study was to measure the performance with balanced scorecard, analyze and recommend the results to the company. The research method used is a case study and survei methods with descriptive research. The results of this study indicate that the performance of the financial perspective quite good includes the profits, revenue, productivity, and the short term liabilities have not been able to be achieved as expectations. For Customer perspective, the performance of the companies is very good where customer satisfaction and loyalty must be maintained, for the continuation of the order. For Internal Business Process perspective, the company's performance in terms of both innovation and quality of products are very good, but in the time of processing product distribution is average and company has been able to fix it with the strategic objectives effectively and efficiently. For learning and growth perspective, the performance is good at all points but in the employee productivity and commitment, the targets have not been able to be achieved and the application of the information technology is very good. Overall assessment of performance on the PT.Bahtera Utama is good with the score of 4.29

    Measuring Systemic Risk of Banking in Indonesia: Conditional Value at Risk Model Application

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    Systemic risk is a risk of collapse of the financial system that would cause the financial system is not functioning properly. Measurement of systemic risk in the financial institutions, especially banks are crucial, because banks are highly vulnerable to financial crisis. In this study, to estimate the conditional value-at-risk (CoVaR) used quantile regression. Samples in this study of 9 banks have total assets of the largest in Indonesia. Testing the correlation between VaR and ΔCoVaR in this study using Spearman correlation and Kendall\u27s Tau. There are five banks that have a significant correlation between VaR and ΔCoVaR, meanwhile four others banks in the sample did not have a significant correlation. However, the correlation coefficient is below 0.50, which indicates that there is a weak correlation between VaR and CoVaR.DOI: 10.15408/sjie.v6i2.529

    Post clamp

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    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post

    Damping of an oscillating scalar field indirectly coupled to a thermal bath

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    The damping process of a homogeneous oscillating scalar field that indirectly interacts with a thermal bath through a mediator field is investigated over a wide range of model parameters. We consider two types of mediator fields, those that can decay to the thermal bath and those that are individually stable but pair annihilate. The former case has been extensively studied in the literature by treating the damping as a local effect after integrating out the assumed close-to-equilibrium mediator field. The same approach does not apply if the mediator field is stable and freezes out of equilibrium. To account for the latter case, we adopt a non-local description of damping that is only meaningful when we consider full half-oscillations of the field being damped. The damping rates of the oscillating scalar field and the corresponding heating rate of the thermal bath in all bulk parameter regions are calculated in both cases, corroborating previous results in the direct decay case. Using the obtained results, the time it takes for the amplitude of the scalar field to be substantially damped is estimated.Comment: 39 pages, 9 figures, 1 table; typos corrected, references adde
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