Discovery of a new INTEGRAL source: IGR J19140+0951

IGR J19140+0951 (formerly known as IGR J19140+098) was discovered with the INTEGRAL satellite in March 2003. We report the details of the discovery, using an improved position for the analysis. We have performed a simultaneous study of the 5-100 keV JEM-X and ISGRI spectra from which we can distinguish two different states. From the results of our analysis we propose that IGR J19140+0951 is a persistent Galactic X-ray binary, probably hosting a neutron star although a black hole cannot be completely ruled out.Comment: 4 pages, 4 figures. Accepted for publication in A&A

A Protocol for Generating Random Elements with their Probabilities

We give an AM protocol that allows the verifier to sample elements x from a probability distribution P, which is held by the prover. If the prover is honest, the verifier outputs (x, P(x)) with probability close to P(x). In case the prover is dishonest, one may hope for the following guarantee: if the verifier outputs (x, p), then the probability that the verifier outputs x is close to p. Simple examples show that this cannot be achieved. Instead, we show that the following weaker condition holds (in a well defined sense) on average: If (x, p) is output, then p is an upper bound on the probability that x is output. Our protocol yields a new transformation to turn interactive proofs where the verifier uses private random coins into proofs with public coins. The verifier has better running time compared to the well-known Goldwasser-Sipser transformation (STOC, 1986). For constant-round protocols, we only lose an arbitrarily small constant in soundness and completeness, while our public-coin verifier calls the private-coin verifier only once

Efficient computation of matched solutions of the Kapchinskij-Vladimirskij envelope equations for periodic focusing lattices

A new iterative method is developed to numerically calculate the periodic, matched beam envelope solution of the coupled Kapchinskij-Vladimirskij (KV) equations describing the transverse evolution of a beam in a periodic, linear focusing lattice of arbitrary complexity. Implementation of the method is straightforward. It is highly convergent and can be applied to all usual parameterizations of the matched envelope solutions. The method is applicable to all classes of linear focusing lattices without skew couplings, and also applies to all physically achievable system parameters -- including where the matched beam envelope is strongly unstable. Example applications are presented for periodic solenoidal and quadrupole focusing lattices. Convergence properties are summarized over a wide range of system parameters.Comment: 20 pages, 5 figures, Mathematica source code provide

An Improved Interactive Streaming Algorithm for the Distinct Elements Problem

The exact computation of the number of distinct elements (frequency moment $F_0$) is a fundamental problem in the study of data streaming algorithms. We denote the length of the stream by $n$ where each symbol is drawn from a universe of size $m$. While it is well known that the moments $F_0,F_1,F_2$ can be approximated by efficient streaming algorithms, it is easy to see that exact computation of $F_0,F_2$ requires space $\Omega(m)$. In previous work, Cormode et al. therefore considered a model where the data stream is also processed by a powerful helper, who provides an interactive proof of the result. They gave such protocols with a polylogarithmic number of rounds of communication between helper and verifier for all functions in NC. This number of rounds $\left(O(\log^2 m) \;\text{in the case of} \;F_0 \right)$ can quickly make such protocols impractical. Cormode et al. also gave a protocol with $\log m +1$ rounds for the exact computation of $F_0$ where the space complexity is $O\left(\log m \log n+\log^2 m\right)$ but the total communication $O\left(\sqrt{n}\log m\left(\log n+ \log m \right)\right)$. They managed to give $\log m$ round protocols with $\operatorname{polylog}(m,n)$ complexity for many other interesting problems including $F_2$, Inner product, and Range-sum, but computing $F_0$ exactly with polylogarithmic space and communication and $O(\log m)$ rounds remained open. In this work, we give a streaming interactive protocol with $\log m$ rounds for exact computation of $F_0$ using $O\left(\log m \left(\,\log n + \log m \log\log m\,\right)\right)$ bits of space and the communication is $O\left( \log m \left(\,\log n +\log^3 m (\log\log m)^2 \,\right)\right)$. The update time of the verifier per symbol received is $O(\log^2 m)$.Comment: Submitted to ICALP 201

Customer Focused Price Optimisation

Tesco want to better understand how to set online prices for their general merchandise (i.e. not groceries or clothes) in the UK. Because customers can easily compare prices from different retailers we expect they will be very sensitive to price, so it is important to get it right. There are four aspects of the problem. • Forecasting: Estimating the customer demand as a function of the price chosen (especially hard for products with no sales history or infrequent sales). • Objective function: What exactly should Tesco aim to optimise? Sales volume? Profit? Profit margin? Conversion rates? • Optimisation: How to choose prices for many related products to optimise the chosen objective function. • Evalution: How to demonstrate that the chosen prices are optimal, especially to people without a mathematical background. Aggregate sales data was provided for about 400 products over about 2 years so that quantitive approaches could be tested. For some products competitors’ prices were also provided

Polyester/cotton for pillow cases

This investigation was limited in scope to strength, appearance and color change. The polyester/cotton cases did maintain strength for this specified period but other physical properties which were not measured could be important such as pilling and tear strength after longer wear. The cases were not worn to destruction by 45 launderings. They apparently have a much longer wear period

Rugs and Carpets

Carpets and rugs help to make a home attractive, cozy, and livable in any or all rooms - including the kitchen and bathroom. It is important to select carpeting which will give you the most satisfaction and which is best suited for your particular needs and situation

Socioeconomic predictors and consequences of depression among primary care attenders with non-communicable diseases in the Western Cape, South Africa:Cohort study within a randomised trial

Background: Socioeconomic predictors and consequences of depression and its treatment were investigated in 4393 adults with specified non-communicable diseases attending 38 public sector primary care clinics in the Eden and Overberg districts of the Western Cape, South Africa.   Methods: Participants were interviewed at baseline in 2011 and 14 months later, as part of a randomised controlled trial of a guideline-based intervention to improve diagnosis and management of chronic diseases. The 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) was used to assess depression symptoms, with higher scores representing more depressed mood. Results: Higher CESD-10 scores at baseline were independently associated with being less educated (p=0.004) and having lower income (p=0.003). CESD-10 scores at follow-up were higher in participants with less education (p=0.010) or receiving welfare grants (p=0.007) independent of their baseline scores. Participants with CESD-10 scores of 10 or more at baseline (56% of all participants) had 25% higher odds of being unemployed at follow-up (p=0.016), independently of baseline CESD-10 score and treatment status. Among participants with baseline CESD-10 scores of 10 or more, antidepressant medication at baseline was independently more likely in participants who had more education (p=0.002), higher income (p<0.001), or were unemployed (p=0.001). Antidepressant medication at follow up was independently more likely in participants with higher income (p=0.023), and in clinics with better access to pharmacists (p=0.053) and off-site drug delivery (p=0.013).  Conclusions: Socioeconomic disadvantage appears to be both a cause and consequence of depression, and may also be a barrier to treatment. There are opportunities for improving the prevention, diagnosis and treatment of depression in primary care in inequitable middle income countries like South Africa.  Trial registration: The trial is registered with Current Controlled Trials (ISRCTN20283604) and the Office for Human Research Protections Database (IRB00001938, FWA00001637)

INTEGRAL observations of the black hole candidate H 1743-322 in outburst

INTEGRAL made 3 observations in 2003 April of the black hole candidate H 1743-322 during the rising part, and close to the maximum, of an outburst. H 1743-322 was previously observed in outburst in 1977-1978. The source is located in a crowded region of the sky (l = 357 deg, b = -2 deg) and at least 18 sources are clearly detected in the field of view of the gamma-ray imager during a 277 ksec exposure. These are well known persistent X-ray binaries and 3 transient sources in outburst. The combined 5-200 keV JEM-X and SPI spectrum of H 1743-322 is well fit with an absorbed ((2.5 10E22 atom/cm2) soft (photon index 2.70 +/- 0.09) power-law model consistent with J 1743-322 being in a high/soft state.Comment: 5 pages. Figs. 2 and 3 are best viewed in color. To appear in INTEGRAL special edition of A&A

Rational sequences for the conductance in quantum wires from affine Toda field theories

We analyse the expression for the conductance of a quantum wire which is decribed by an integrable quantum field theory. In the high temperature regime we derive a simple formula for the filling fraction. This expression involves only the inverse of a matrix which contains the information of the asymptotic phases of the scattering matrix and the solutions of the constant thermodynamic Bethe ansatz equations. Evaluating these expressions for minimal affine Toda field theory we recover several sequences of rational numbers, which are multiples of the famous Jain sequence for the filling fraction occurring in the context of the fractional quantum Hall effect. For instance we obtain $\nu= 4 m/(2m +1)$ for $A_{4m-1}$-minimal affine Toda field theory. The matrices involved have in general non-rational entries and are not part of previous classification schemes based on integral lattices.Comment: 9 pages Latex, version to appear in Journal of Physics