Load Balancing in the Non-Degenerate Slowdown Regime

We analyse Join-the-Shortest-Queue in a contemporary scaling regime known as the Non-Degenerate Slowdown regime. Join-the-Shortest-Queue (JSQ) is a classical load balancing policy for queueing systems with multiple parallel servers. Parallel server queueing systems are regularly analysed and dimensioned by diffusion approximations achieved in the Halfin-Whitt scaling regime. However, when jobs must be dispatched to a server upon arrival, we advocate the Non-Degenerate Slowdown regime (NDS) to compare different load-balancing rules. In this paper we identify novel diffusion approximation and timescale separation that provides insights into the performance of JSQ. We calculate the price of irrevocably dispatching jobs to servers and prove this to within 15% (in the NDS regime) of the rules that may manoeuvre jobs between servers. We also compare ours results for the JSQ policy with the NDS approximations of many modern load balancing policies such as Idle-Queue-First and Power-of-$d$-choices policies which act as low information proxies for the JSQ policy. Our analysis leads us to construct new rules that have identical performance to JSQ but require less communication overhead than power-of-2-choices.Comment: Revised journal submission versio

Deducing the Multi-Trader Population Driving a Financial Market

We previously laid out a framework for predicting financial movements and pockets of predictability by deducing the heterogeneity in the multi-agent population in temrs of trader types playing in an artificial financial market model [7]. This work explores extensions to this basic framework. We allow for more intelligent agents with a richer strategy set, and we no longer constrain the estimate for the heterogeneity over the agents to a probability space. We then introduce a scheme which accounts for models with a wide variety of agent types. We also discuss a mechanism for bias removal on the estimates of the relevant parameters

Will it gel? Successful computational prediction of peptide gelators using physicochemical properties and molecular fingerprints

The self-assembly of low molecular weight gelators to form gels has enormous potential for cell culturing, optoelectronics, sensing, and for the preparation of structured materials. There is an enormous “chemical space” of gelators. Even within one class, functionalised dipeptides, there are many structures based on both natural and unnatural amino acids that can be proposed and there is a need for methods that can successfully predict the gelation propensity of such molecules. We have successfully developed computational models, based on experimental data, which are robust and are able to identify in silico dipeptide structures that can form gels. A virtual computational screen of 2025 dipeptide candidates identified 9 dipeptides that were synthesised and tested. Every one of the 9 dipeptides synthesised and tested were correctly predicted for their gelation properties. This approach and set of tools enables the “dipeptide space” to be searched effectively and efficiently in order to deliver novel gelator molecules

Early introduction of water and complementary feeding and nutritional status of children in northern Senegal

Abstract Objective Malnutrition is responsible globally for 60% of deaths among children under 5 years and is often attributed to suboptimal feeding practices. In response, the World Health Organization recommends exclusive breast-feeding for the first 6 months of life. The objective of this study was to determine if an association exists between the early introduction of water and complementary foods (CFs) and the nutritional status of children in northern Senegal. Design/Setting/Subjects A cross-sectional study of 374 children in the Podor Health District between the ages of 6 and 23 months was conducted. Knowledge and behaviours of mothers regarding introduction of water and CFs were assessed via individual interviews. Results Water was introduced to about 85% of the children in the first 3 months of life and 62% were fed CFs before 6 months. Overall, 16% had clinically significant wasting (weight-for-length Z-score (WHZ) less than −2) and 20% had stunting (height-for-age Z-score (HAZ) less than −2). There was no significant association between wasting or stunting and introduction of water before 3 months (WHZ: odds ratio=0.99, 95% confidence interval 0.46-2.14, P=0.97; HAZ: 0.68, 0.34-1.36, P=0.3) or introduction of CFs before 6 months (WHZ: 0.81, 0.46-1.42, P=0.5; HAZ: 0.79, 0.46-1.35, P=0.4). A significant association was found between wasting and male sex, age, living in Guede community, drinking river/pond water and large family size, while stunting was associated with age and drinking tap water. Conclusion The results of the present study suggest that early introduction of water and CFs is frequent and is not associated with increased risk for malnutrition among children from this region of northern Senegal, but the possibility of reverse causality cannot be exclude

Monitoring exercise-induced muscle fatigue and adaptations: Making sense of popular or emerging indices and biomarkers

Regular exercise with the appropriate intensity and duration may improve an athlete’s physical capacities by targeting different performance determinants across the endurance–strength spectrum aiming to delay fatigue. The mechanisms of muscle fatigue depend on exercise intensity and duration and may range from substrate depletion to acidosis and product inhibition of adenosinetriphosphatase (ATPase) and glycolysis. Fatigue mechanisms have been studied in isolated muscles; single muscle fibers (intact or skinned) or at the level of filamentous or isolated motor proteins; with each approach contributing to our understanding of the fatigue phenomenon. In vivo methods for monitoring fatigue include the assessment of various functional indices supported by the use of biochemical markers including blood lactate levels and more recently redox markers. Blood lactate measurements; as an accompaniment of functional assessment; are extensively used for estimating the contribution of the anaerobic metabolism to energy expenditure and to help interpret an athlete’s resistance to fatigue during high intensity exercise. Monitoring of redox indices is gaining popularity in the applied sports performance setting; as oxidative stress is not only a fatigue agent which may play a role in the pathophysiology of overtraining syndrome; but also constitutes an important signaling pathway for training adaptations; thus reflecting training status. Careful planning of sampling and interpretation of blood biomarkers should be applied; especially given that their levels can fluctuate according to an athlete’s lifestyle and training histories

Dimensional Reduction and Screening Masses in Pure Gauge Theories at Finite Temperature

We studied screening masses in the equilibrium thermodynamics of SU(2) and SU(3) pure gauge theories on the lattice. At a temperature of 2 Tc we found strong evidence for dimensional reduction in the non-perturbative spectrum of screening masses. Mass ratios in the high temperature SU(3) theory are consistent with those in the pure gauge theory in three dimensions. At the first order SU(3) phase transition we report the first measurement of the true scalar screening mass.Comment: 34 pages, 10 figure

Analytic doubly periodic wave patterns for the integrable discrete nonlinear Schroedinger (Ablowitz-Ladik) model

We derive two new solutions in terms of elliptic functions, one for the dark and one for the bright soliton regime, for the semi-discrete cubic nonlinear Schroedinger equation of Ablowitz and Ladik. When considered in the complex plane, these two solutions are identical. In the continuum limit, they reduce to known elliptic function solutions. In the long wave limit, the dark one reduces to the collision of two discrete dark solitons, and the bright one to a discrete breather.Comment: 12 pages, 2 figures. To appear, Physics Letters