Pion-kaon femtoscopy in Pb−-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV measured with ALICE

Femtoscopic correlations between charged pions and kaons for different charge combinations are measured in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV with ALICE at the LHC. The three-dimensional pion-kaon ($\pi-{\rm K}$) correlation functions and double ratios in the out-side-long pair rest frame are studied in different centrality bins. The $\pi-{\rm K}$ femtoscopic source size parameter ($R_{\rm out}$) and emission asymmetry ($\mu_{\rm out}$) are extracted. It is observed that the average source size of the system and the emission asymmetry between pions and kaons increase from peripheral to central events.Comment: 4 pages, 4 figures, Proceedings of XXVIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018

Non-identical particle femtoscopy in Pb−-Pb collisions at sNN=2.76 \mathbf{\sqrt{{\textit s}_{\rm NN}}}=2.76 TeV measured with ALICE

Two-particle femtoscopic correlations between non-identical charged particles for different charge combinations are measured in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV with ALICE at the LHC. The three-dimensional two-particle correlation functions are studied in different centrality bins. The femtoscopic source size parameter ($R_{Out}$) and emission asymmetry ($\mu$) are extracted. It is observed that the average source size of the system and emission asymmetry between particles increase from peripheral to central events.Comment: 3 pages, 2 figures, Proceedings of XXXIX International Conference on High Energy Physics (ICHEP 2018

DistancePPG: Robust non-contact vital signs monitoring using a camera

Vital signs such as pulse rate and breathing rate are currently measured using contact probes. But, non-contact methods for measuring vital signs are desirable both in hospital settings (e.g. in NICU) and for ubiquitous in-situ health tracking (e.g. on mobile phone and computers with webcams). Recently, camera-based non-contact vital sign monitoring have been shown to be feasible. However, camera-based vital sign monitoring is challenging for people with darker skin tone, under low lighting conditions, and/or during movement of an individual in front of the camera. In this paper, we propose distancePPG, a new camera-based vital sign estimation algorithm which addresses these challenges. DistancePPG proposes a new method of combining skin-color change signals from different tracked regions of the face using a weighted average, where the weights depend on the blood perfusion and incident light intensity in the region, to improve the signal-to-noise ratio (SNR) of camera-based estimate. One of our key contributions is a new automatic method for determining the weights based only on the video recording of the subject. The gains in SNR of camera-based PPG estimated using distancePPG translate into reduction of the error in vital sign estimation, and thus expand the scope of camera-based vital sign monitoring to potentially challenging scenarios. Further, a dataset will be released, comprising of synchronized video recordings of face and pulse oximeter based ground truth recordings from the earlobe for people with different skin tones, under different lighting conditions and for various motion scenarios.Comment: 24 pages, 11 figure

Parallel versus off-pathway Michaelis-Menten mechanism for single-enzyme kinetics of a fluctuating enzyme

Recent fluorescence spectroscopy measurements of the turnover time distribution of single-enzyme turnover kinetics of $\beta$-galactosidase provide evidence of Michaelis-Menten kinetics at low substrate concentration. However, at high substrate concentrations, the dimensionless variance of the turnover time distribution shows systematic deviations from the Michaelis-Menten prediction. This difference is attributed to conformational fluctuations in both the enzyme and the enzyme-substrate complex and to the possibility of both parallel and off-pathway kinetics. Here, we use the chemical master equation to model the kinetics of a single fluctuating enzyme that can yield a product through either parallel or off-pathway mechanisms. An exact expression is obtained for the turnover time distribution from which the mean turnover time and randomness parameters are calculated. The parallel and off-pathway mechanisms yield strikingly different dependences of the mean turnover time and the randomness parameter on the substrate concentration. In the parallel mechanism, the distinct contributions of enzyme and enzyme-substrate fluctuations are clearly discerned from the variation of the randomness parameter with substrate concentration. From these general results we conclude that an off-pathway mechanism, with substantial enzyme-substrate fluctuations, is needed to rationalize the experimental findings of single-enzyme turnover kinetics of $\beta$-galactosidase.Comment: 27 pages, 5 figure

An Examination of the Maturity Effect in the Indian Commodities Futures Market

This paper has examined the Samuelson’s hypothesis which states that the price volatility increases as the contract nears its maturity. It has also examined the BCSS hypothesis which provides that negative covariance between the spot price and net cost of carry explains the maturity effect. The study has examined these hypotheses on the data for wheat and pepper futures contract traded at NCDEX from the date of listing of the contract to 31st March 2007 and the maturity effect has been examined for each contract individually. The study has indicated that maturity effect is present in around 45 per cent of the wheat and pepper contracts. Evidence supporting the BCSS hypothesis is present more strongly in the case of wheat as compared to pepper and 79 per cent of the contracts having maturity effect have depicted negative covariance in the case of wheat. Thus, it can be concluded that maturity effect is present and it is explained to a large extent by the negative co-variance between spot price and net carry cost. The study has observed that there is further scope for research in this area in relation to other agricultural commodities and also metals. Further studies can also be undertaken to find the informational efficiency and the reaction of informational flow to identify the reasons for the presence or absence of maturity effect.Agricultural and Food Policy,

New physics solutions for RDR_D and RD∗R_{D^*}

Recent measurements of $R_{D^*}$ have reduced tension with the Standard Model prediction. Taking all the present data into account, we obtain the values of the Wilson coefficients of each new physics four-fermion operator of a given Lorentz structure. We find that the combined data rule out most of the solutions based on scalar/pseudoscalar operators. By studying the inter-relations between different solutions, we find that there are only four allowed solutions, which are based on operators with $(V-A)$, linear combination of $(V-A)$ and $(V+A)$, tensor and linear combination of scalar/pseudoscalar and tensor structure. We demonstrate that the need for new physics is driven by those measurement of $R_D$ and $R_{D^*}$ where the $\tau$ lepton is not studied. Further, we show that new physics only in $b\rightarrow c\,\mu\,\bar{\nu}$ is not compatible with the full set of observables in the decays $B\rightarrow Dl\bar{\nu}$ and $B\rightarrow D^*l\bar{\nu}$.Comment: 16 pages, 1 figure (Accepted for publication in JHEP