Analysis of adaptive algorithms for an integrated communication network

Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes

Among-site variability in the stochastic dynamics of East African coral reefs

Coral reefs are dynamic systems whose composition is highly influenced by unpredictable biotic and abiotic factors. Understanding the spatial scale at which long-term predictions of reef composition can be made will be crucial for guiding conservation efforts. Using a 22-year time series of benthic composition data from 20 reefs on the Kenyan and Tanzanian coast, we studied the long-term behaviour of Bayesian vector autoregressive state-space models for reef dynamics, incorporating among-site variability. We estimate that if there were no among-site variability, the total long-term variability would be approximately one third of its current value. Thus among-site variability contributes more to long-term variability in reef composition than does temporal variability. Individual sites are more predictable than previously thought, and predictions based on current snapshots are informative about long-term properties. Our approach allowed us to identify a subset of possible climate refugia sites with high conservation value, where the long-term probability of coral cover <= 0.1 was very low. Analytical results show that this probability is most strongly influenced by among-site variability and by interactions among benthic components within sites. These findings suggest that conservation initiatives might be successful at the site scale as well as the regional scale.Comment: 97 pages, 49 figure

Simultaneous computation of dynamical and equilibrium information using a weighted ensemble of trajectories

Equilibrium formally can be represented as an ensemble of uncoupled systems undergoing unbiased dynamics in which detailed balance is maintained. Many non-equilibrium processes can be described by suitable subsets of the equilibrium ensemble. Here, we employ the "weighted ensemble" (WE) simulation protocol [Huber and Kim, Biophys. J., 1996] to generate equilibrium trajectory ensembles and extract non-equilibrium subsets for computing kinetic quantities. States do not need to be chosen in advance. The procedure formally allows estimation of kinetic rates between arbitrary states chosen after the simulation, along with their equilibrium populations. We also describe a related history-dependent matrix procedure for estimating equilibrium and non-equilibrium observables when phase space has been divided into arbitrary non-Markovian regions, whether in WE or ordinary simulation. In this proof-of-principle study, these methods are successfully applied and validated on two molecular systems: explicitly solvated methane association and the implicitly solvated Ala4 peptide. We comment on challenges remaining in WE calculations

FSI simulations for explosions very near reinforced concrete structures

The analysis of explosives in contact or very near to reinforced concrete (RC) structures is an important aspect in the design of protective structures and vulnerability assessments. Although this remains a topic of high importance for defence, a more widespread interest has developed as civilian structures become the targets of terrorism. This type of assessment requires a robust simulation method for coupled fluid-structural interactions (FSI) which can handle the explosive detonation, air blast propagation, structural deformation, and damage evolution. This paper describes the application of a loose-coupling method which combines the FEFLO CFD code and SAIC’s CSD code for 3D numerical simulations of unconfined and semi-confined explosions near RC structures. This approach takes advantage of the unstructured tetrahedral mesh for the CFD and an embedded method for CSD structures inside the fluid domain. Comparisons of simulations with experiment provide validation, but also reveal some weaknesses of the method. A good agreement between simulation and experiment is found with moderate explosive loading. However, a severe explosive loading with confinement results in extensive damage to the structure which is difficult to reproduce in simulations

Development of a healthy ageing index in Latin American countries - a 10/66 dementia research group population-based study.

BACKGROUND: Our population is ageing and in 2050 more than one out of five people will be 60 years or older; 80% of whom will be living in a low-and-middle income country. Living longer does not entail living healthier; however, there is not a widely accepted measure of healthy ageing hampering policy and research. The World Health Organization defines healthy ageing as the process of developing and maintaining functional ability that will enable well-being in older age. We aimed to create a healthy ageing index (HAI) in a subset of six low-and-middle income countries, part of the 10/66 study, by using items of functional ability and intrinsic capacity. METHODS: The study sample included residents 65-years old and over (n = 12,865) from catchment area sites in Cuba, Dominican Republic, Peru, Venezuela, Mexico and Puerto Rico. Items were collected by interviewing participants or key informants between 2003 and 2010. Two-stage factor analysis was employed and we compared one-factor, second-order and bifactor models. The psychometric properties of the index, including reliability, replicability, unidimensionality and concurrent convergent validity as well as measurement invariance per ethnic group and gender were further examined in the best fit model. RESULTS: The bifactor model displayed superior model fit statistics supporting that a general factor underlies the various items but other subdomain factors are also needed. The HAI indicated excellent reliability (ω = 0.96, ωΗ = 0.84), replicability (H = 0.96), some support for unidimensionality (Explained Common Variance = 0.65) and some concurrent convergent validity with self-rated health. Scalar measurement invariance per ethnic group and gender was supported. CONCLUSIONS: A HAI with excellent psychometric properties was created by using items of functional ability and intrinsic capacity in a subset of six low-and-middle income countries. Further research is needed to explore sub-population differences and to validate this index to other cultural settings

Picosecond X-ray Absorption Spectroscopy of Photochemical Transient Species in Solution

A photoinduced Fe(II) spin crossover reaction in solution is studied with ultrafast x-ray absorption spectroscopy. The iron-nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state

Feeling connected again: interventions that increase social identification reduce depression symptoms in community and clinical settings

Background: Clinical depression is often preceded by social withdrawal, however, limited research has examined whether depressive symptoms are alleviated by interventions that increase social contact. In particular, no research has investigated whether social identification (the sense of being part of a group) moderates the impact of social interventions

Багатомовність в Україні та її специфіка

У статті висвітлюються аспекти явища багатомовності, характерні для України як для національної держави, котра продовжує перебувати на стадії трансформації державно-політичної, соціально-економічної, духовної систем. Підкреслюється актуальність «аксіоми національної державності», згідно з якою українська мова, яка є рідною для більшості членів титульної нації країни, має бути єдиною державною мовою.The article studies the aspects of the phenomenon of multilingualism which are characteristic of Ukraine as a national state that remains at the stage of final forming complicated by the transformation of state political, social, economic and spiritual systems. The author underlines actuality of “the axiom of national statehood” that expects Ukrainian to be official language because it is native for the most of members of a titular nation in Ukraine

Novel mutations expand the clinical spectrum of DYNC1H1-associated spinal muscular atrophy

OBJECTIVE To expand the clinical phenotype of autosomal dominant congenital spinal muscular atrophy with lower extremity predominance (SMA-LED) due to mutations in the dynein, cytoplasmic 1, heavy chain 1 (DYNC1H1) gene. METHODS Patients with a phenotype suggestive of a motor, non-length-dependent neuronopathy predominantly affecting the lower limbs were identified at participating neuromuscular centers and referred for targeted sequencing of DYNC1H1. RESULTS We report a cohort of 30 cases of SMA-LED from 16 families, carrying mutations in the tail and motor domains of DYNC1H1, including 10 novel mutations. These patients are characterized by congenital or childhood-onset lower limb wasting and weakness frequently associated with cognitive impairment. The clinical severity is variable, ranging from generalized arthrogryposis and inability to ambulate to exclusive and mild lower limb weakness. In many individuals with cognitive impairment (9/30 had cognitive impairment) who underwent brain MRI, there was an underlying structural malformation resulting in polymicrogyric appearance. The lower limb muscle MRI shows a distinctive pattern suggestive of denervation characterized by sparing and relative hypertrophy of the adductor longus and semitendinosus muscles at the thigh level, and diffuse involvement with relative sparing of the anterior-medial muscles at the calf level. Proximal muscle histopathology did not always show classic neurogenic features. CONCLUSION Our report expands the clinical spectrum of DYNC1H1-related SMA-LED to include generalized arthrogryposis. In addition, we report that the neurogenic peripheral pathology and the CNS neuronal migration defects are often associated, reinforcing the importance of DYNC1H1 in both central and peripheral neuronal functions