Three Dirac operators on two architectures with one piece of code and no hassle

A simple minded approach to implement three discretizations of the Dirac operator (staggered, Wilson, Brillouin) on two architectures (KNL and core i7) is presented. The idea is to use a high-level compiler along with OpenMP parallelization and SIMD pragmas, but to stay away from cache-line optimization and/or assembly-tuning. The implementation is for N_v right-hand-sides, and this extra index is used to fill the SIMD pipeline. On one KNL node single precision performance figures for N_c=3, N_v=12 read 475 Gflop/s, 345 Gflop/s, and 790 Gflop/s for the three discretization schemes, respectively.Comment: 1+6 pages, 3 figures, proceedings of Lattice 2018; v2: typos in eqs. (3.1) and (4.2) corrected, results unchange

Validity of ChPT -- is M_\pi=135 MeV small enough ?

I discuss the practical convergence of the SU(2) ChPT series in the meson sector, based on 2+1 flavor lattice data by the Wuppertal-Budapest and Budapest-Marseille-Wuppertal collaborations. These studies employ staggered and clover-improved Wilson fermions, respectively. In both cases large box volumes and several lattice spacings are used, and the pion masses reach down to the physical mass point. We conclude that LO and NLO low-energy constants can be determined with controlled systematics, if there is sufficient data between the physical mass point and about 350 MeV pion mass. Exploratory LO+NLO+NNLO fits with a wider range reveal some distress of the chiral series near M_\pi ~ 400 MeV and suggest a complete breakdown beyond M_\pi ~ 500 MeV.Comment: 14 pages, 16 figures; written form of plenary talk at Lattice 201

Reconstructing Polyatomic Structures from Discrete X-Rays: NP-Completeness Proof for Three Atoms

We address a discrete tomography problem that arises in the study of the atomic structure of crystal lattices. A polyatomic structure T can be defined as an integer lattice in dimension D>=2, whose points may be occupied by $c$ distinct types of atoms. To ``analyze'' T, we conduct ell measurements that we call_discrete X-rays_. A discrete X-ray in direction xi determines the number of atoms of each type on each line parallel to xi. Given ell such non-parallel X-rays, we wish to reconstruct T. The complexity of the problem for c=1 (one atom type) has been completely determined by Gardner, Gritzmann and Prangenberg, who proved that the problem is NP-complete for any dimension D>=2 and ell>=3 non-parallel X-rays, and that it can be solved in polynomial time otherwise. The NP-completeness result above clearly extends to any c>=2, and therefore when studying the polyatomic case we can assume that ell=2. As shown in another article by the same authors, this problem is also NP-complete for c>=6 atoms, even for dimension D=2 and axis-parallel X-rays. They conjecture that the problem remains NP-complete for c=3,4,5, although, as they point out, the proof idea does not seem to extend to c<=5. We resolve the conjecture by proving that the problem is indeed NP-complete for c>=3 in 2D, even for axis-parallel X-rays. Our construction relies heavily on some structure results for the realizations of 0-1 matrices with given row and column sums

Demographic Dividend or Demographic Threat in Pakistan

Population growth and size have remained the focus of debate for centuries but the recent demographic transition in developing countries has made social scientists take note of the changing age structure of the population as well. As a result of declining population growth and consequent changes in age structure, the proportion of working-age population is increasing in most developing countries, with an associated decline in the dependent age population, offering a window of opportunity to these countries that is referred to as the demographic dividend. Pakistan is also going through the demographic transition, and is experiencing a once-in-a-lifetime demographic dividend as the working-age population bulges and the dependency ratio declines. This paper looks into the demographic dividend available to Pakistan and its implications for the country, mainly through three mechanisms : labour supply, savings, and human capital. For economic benefits to materialise, there is a need for policies dealing with education, public health, and those that promote labour market flexibility and provide incentives for investment and savings. On the contrary, if appropriate policies are not formulated, the demographic dividend might in fact be a cost, leading to unemployment and an unbearable strain on education, health, and old age security.Demographic dividend, age-structure, demographic transition, Pakistan

Demographic Dividend or Demographic Threat in Pakistan

Population growth and size have remained the focus of debate for centuries but the recent demographic transition in developing countries has made social scientists take note of the changing age structure of the population as well. As a result of declining population growth and consequent changes in age structure, the proportion of working-age population is increasing in most developing countries, with an associated decline in the dependent age population, offering a window of opportunity to these countries that is referred to as the “demographic dividend”. Pakistan is also going through the demographic transition, and is experiencing a once-in-a-lifetime demographic dividend as the working-age population bulges and the dependency ratio declines. This paper looks into the demographic dividend available to Pakistan and its implications for the country, mainly through three mechanisms: labour supply, savings, and human capital. For economic benefits to materialise, there is a need for policies dealing with education, public health, and those that promote labour market flexibility and provide incentives for investment and savings. On the contrary, if appropriate policies are not formulated, the demographic dividend might in fact be a cost, leading to unemployment and an unbearable strain on education, health, and old age securityDemographic dividend, age-structure, demographic transition, Pakistan

Reproductive Tract Infections among Women in Pakistan: An Urban Case Study

Reproductive tract infections (RTIs) among women—despite being common and having grave consequences—are not given much attention by policy-makers and health planners. The asymptomatic nature of most infections makes their detection and diagnosis difficult, making laboratory testing the most accurate method of bio-medical diagnosis. The present paper assesses the magnitude and nature of infections as diagnosed through laboratory testing and looks into the variation in magnitude and the nature of RTIs among women with different socio-economic and demographic characteristics. The aetiological rate of infection among women is found to be 24 percent, with the majority of these women testing positive for endogenous infections. Factors significantly increasing the likelihood of having an infection include intrauterine device use or getting a tubectomy, short inter-pregnancy intervals, and lower economic status of women.

Estimating the Middle Class in Pakistan

The concept ‘middle class’ is one of the most commonly used terms in the social sciences, including economics, sociology and political science. Despite its frequent use there is, however, no consensus on what the term exactly implies and its meaning remains ambiguous depending primarily on the context in which it is used. It is viewed as the class that is between, and separates, the lower and the upper classes, that is the rich and the poor, but there is no agreement on the exact boundaries that separates them. Most of the definitions and measurements of the middle class continue to be somewhat arbitrary and vague.

Ground state charmed meson spectra for N_f=2+1+1

We present a preliminary study of the charmed meson spectra using the electrically neutral subset of the new Budapest-Marseille-Wuppertal N_f=2+1+1 gauge configurations that utilise the 3-HEX smeared clover action. The analysis is performed with a focus on the hyperfine splitting.Comment: 7 pages, 5 figures; presentation given at the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14 - 18 July 2015, Kobe, Japa