912 research outputs found

    Neurophysiological defects in temperature-sensitive paralytic mutants of Drosophila melanogaster.

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    Phase-locking transition in a chirped superconducting Josephson resonator

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    By coupling a harmonic oscillator to a quantum system it is possible to perform a dispersive measurement that is quantum non-demolition (QND), with minimal backaction. A non-linear oscillator has the advantage of measurement gain, but what is the backaction? Experiments on superconducting quantum bits (qubits) coupled to a non-linear Josephson oscillator have thus far utilized the switching of the oscillator near a dynamical bifurcation for sensitivity, and have demonstrated partial QND measurement. The detailed backaction associated with the switching process is complex, and may ultimately limit the degree to which such a measurement can be QND. Here we demonstrate a new dynamical effect in Josephson oscillators by which the bifurcation can be accessed without switching. When energized with a frequency chirped drive with an amplitude close to a sharp, phase-locking threshold, the oscillator evolves smoothly in one of two diverging trajectories - a pointer for the state of a qubit. The observed critical behavior agrees well with theory and suggests a new modality for quantum state measurement.Comment: 5 pages, 4 figure

    Sugar-hydrolysing enzymes in gustatory mutants of Drosophila

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    The distribution of the isozymes of α-glucosidase in different parts of Drosophila melanogaster was examined. Two of the eight glucosidase bands are associated with tarsi. The gustatory mutations in the genes gustB and gustC greatly reduce tarsal glucosidase activity, but the enzyme deficiency is not correlated with inability to taste sugars

    Millikelvin thermal and electrical performance of lossy transmission line filters

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    We report on the scattering parameters and Johnson noise emission of low-pass stripline filters employing a magnetically loaded silicone dielectric down to 25 mK. The transmission characteristic of a device with f−3dBf_{-3dB}=1.3 GHz remains essentially unchanged upon cooling. Another device with f−3dBf_{-3dB}=0.4 GHz, measured in its stopband, exhibits a steady state noise power emission consistent with a temperature difference of a few mK relative to a well-anchored cryogenic microwave attenuator at temperatures down to 25 mK, thus presenting a matched thermal load.Comment: 4 pages, 4 figure

    Quantum Fluctuations in the Chirped Pendulum

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    An anharmonic oscillator when driven with a fast, frequency chirped voltage pulse can oscillate with either small or large amplitude depending on whether the drive voltage is below or above a critical value-a well studied classical phenomenon known as autoresonance. Using a 6 GHz superconducting resonator embedded with a Josephson tunnel junction, we have studied for the first time the role of noise in this non-equilibrium system and find that the width of the threshold for capture into autoresonance decreases as the square root of T, and saturates below 150 mK due to zero point motion of the oscillator. This unique scaling results from the non-equilibrium excitation where fluctuations, both quantum and classical, only determine the initial oscillator motion and not its subsequent dynamics. We have investigated this paradigm in an electrical circuit but our findings are applicable to all out of equilibrium nonlinear oscillators.Comment: 5 pages, 4 figure

    Wavelet transforms of meteorological parameters and gravity waves

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    The main purpose of this paper is to analyze some characteristics of gravity waves (GWs), and seasonal variations of atmospheric waves over Istanbul by using wavelet techniques. Daily radiosonda data of Istanbul in the troposphere and lower stratosphere (1000hPa-30hPa) between 1993 and 1997 have been considered. Wavelet analysis based on a computer simulation of data is generally close to the real data when Daubechies wavelet series are used. Daily, monthly, seasonal and annual variations of pressure heights, air temperature and deviations from mean values have been analyzed. Variations show the effects of gravity waves for different pressure levels in the troposphere. These waves lead to the meso-scale wave-form structures in spring, autumn and winter. As a result of this study, wavelet series and transforms for data construction, definition of some discontinuities and the local effects on the signal have been compared with the results of previous studies. The most similar structure between temperature, turbulence parameters and geo-potential height deviations has been defined at the 500-hPa pressure level

    Study of Solitons on submanifolds of Kenmotsu statistical manifolds

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    The differential geometry of Kenmotsu manifold is a valuable part of contact geometry with nice applications in other fields such as theoretical physics. Theoretical physicists have also been looking into the equation of Ricci soliton and Yamabe soliton in relation with Einstein manifolds, Quasi Einstein manifolds and string theory. In this research servey, we examine the Ricci solitons and Yamabe soliton on statistical counterpart of a Kenmotsu manifold, that is, Kenmotsu statistical manifold with some related examples. We investigate some statistical curvature properties of Kenmotsu statistical manifolds. Also, we study the almost η\eta-Ricci solitons on submanifolds of Kenmotsu statistical manifold with concircular vector field. Furthermore, we have also discuss the behavior of almost quasi-Yamabe soliton on subamnifolds of Kenmotsu statistical manifolds endowed with concircular vector field and concurrent vector filed. Finally, we have furnish an example of 55-dimensional Kenmotsu statistical manifolds admitting the η\eta-Ricci soliton and almost quasi-Yamabe soliton as well.Comment: arXiv admin note: text overlap with arXiv:1902.0929

    A rapid method for measuring olfactory responses of Drosophila larva

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    STANDARDIZATION OF SEED VIABILITY PROTOCOL FOR PINUS WALLICHIANA A.B.JACKSON IN KASHMIR, INDIA

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    ABSTRACT Pinus wallichiana seeds were subjected to tetrazolium test in order to evaluate their viability characteristics. Seeds were soaked in distilled water for 24 hours followed by soaking in 1% tetrazolium salt and incubated at 30 o C ±1 temperature in dark for 36 hours. Six staining patterns were recognized. Root mean square method was applied to determine the viable categories. Three staining patterns represented viable and three non-viable seeds. The tetrazolium staining, an established method of testing seed viability was compared with germination test. Nine seed lots were tested by each method .A close relationship was observed in the results of TTC test and germination test in the present investigation. The tetrazolium staining technique thus potentially provides an immediate and rapid method for determining seed viability

    Behaviour change intervention for smokeless tobacco cessation: its development, feasibility and fidelity testing in Pakistan and in the UK

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    Background: People of South Asian-origin are responsible for more than three-quarters of all the smokeless tobacco (SLT) consumption worldwide; yet there is little evidence on the effect of SLT cessation interventions in this population. South Asians use highly addictive and hazardous SLT products that have a strong socio-cultural dimension. We designed a bespoke behaviour change intervention (BCI) to support South Asians in quitting SLT and then evaluated its feasibility in Pakistan and in the UK. Methods: We conducted two literature reviews to identify determinants of SLT use among South Asians and behaviour change techniques (BCTs) likely to modify these, respectively. Iterative consensus development workshops helped in selecting potent BCTs for BCI and designing activities and materials to deliver these. We piloted the BCI in 32 SLT users. All BCI sessions were audiotaped and analysed for adherence to intervention content and the quality of interaction (fidelity index). In-depth interviews with16 participants and five advisors assessed acceptability and feasibility of delivering the BCI, respectively. Quit success was assessed at 6 months by saliva/urine cotinine. Results: The BCI included 23 activities and an interactive pictorial resource that supported these. Activities included raising awareness of the harms of SLT use and benefits of quitting, boosting clients’ motivation and self-efficacy, and developing strategies to manage their triggers, withdrawal symptoms, and relapse should that occur. Betel quid and Guthka were the common forms of SLT used. Pakistani clients were more SLT dependent than those in the UK. Out of 32, four participants had undetectable cotinine at 6 months. Fidelity scores for each site varied between 11.2 and 42.6 for adherence to content – maximum score achievable 44; and between 1.4 and 14 for the quality of interaction - maximum score achievable was 14. Interviews with advisors highlighted the need for additional training on BCTs, integrating nicotine replacement and reducing duration of the pre-quit session. Clients were receptive to health messages but most reported SLT reduction rather than complete cessation. Conclusion: We developed a theory-based BCI that was also acceptable and feasible to deliver with moderate fidelity scores. It now needs to be evaluated in an effectiveness trial
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