A new approach to uncover dynamic phase coordination and synchronization

Phase attractive maps are an essential mechanism of multi-stable systems such as found in coupled neuronal oscillators. An essential feature of this type of dynamic nonlinear coordination is dynamic phase synchronization. The identification of dynamic phase synchronizations is complicated due to changing frequency ratios of synchronized intervals, other nonstationarities, and noise. In order to overcome these problems the momentary phase relations and their statistics were analyzed by several authors. In this way phase synchronizations also in chaotic and noisy oscillating systems could be uncovered. We propose a novel method which avoids one essential limitation of these approaches, namely the necessity of presetting particular frequency ratios of interest. The proposed novel method was validated by its application to a simulated driven neuronal generator during the transition period between different synchronization modes and to dynamically coupled components of sympathetic nerve discharges.     

Using mutual information to measure coupling in the cardiorespiratory system

Approximately 2,000 infants with sickle cell disease are born each year in the United States. Sickle cell disease is an inherited disorder of red blood cell hemoglobin. Sickle cells increase adhesion and cause blockage in the small blood vessels, resulting in tissue damage. The cells' production of hemoglobin S results in two major pathophysiologic features of sickle cell disorders: chronic hemolytic anemia and vaso-occlusion. These disorders cause ischemic tissue damage and acute and chronic organ failure. Potential complications for children with sickle cell disease include vaso-occlusive events, splenic sequestration, bacterial septicemia from splenic hypofunction, aplastic crisis, pulmonary compromise including acute chest syndrome, renal tubular dysfunction and renal failure, priapism, aseptic necrosis, gallstones, delayed growth and development, leg ulcers, stroke and premature death. Three major sickle cell complications during the first years of life are dactylitis, splenic hypofunction and splenic sequestration. The risk for pneumococcal meningitis is 36 times greater in children with sickle cell anemia than for black children without the disease, and 314 times greater than for white children.     

Topographic independent component analysis.

In ordinary independent component analysis, the components are assumed to be completely independent, and they do not necessarily have any meaningful order relationships. In practice, however, the estimated "independent" components are often not at all independent. We propose that this residual dependence structure could be used to define a topographic order for the components. In particular, a distance between two components could be defined using their higher-order correlations, and this distance could be used to create a topographic representation. Thus, we obtain a linear decomposition into approximately independent components, where the dependence of two components is approximated by the proximity of the components in the topographic representation.     

Dynamic viscosities of pure tin and Sn-Ag,Sn-Cu,and Sn-Ag-Cu eutectic melts

The dynamic viscosities of the melts of pure tin and eutectic Sn-Ag, Sn-Cu, and Sn-Ag-Cu alloys are studied in heating followed by cooling, and the maximum heating temperature was 1200°C. An irreversible decrease in the viscosity is found in the temperature range 800–1000°C in the polytherms of all melts. This finding is related to the loss of a local order in a melt and can be used to develop temperature regimes for the production of lead-free solders.     

Cognitive skill acquisition and transfer in younger and older adults.

The acquisition of cognitive skills often depends on 1 of (or a combination of) 2 processes, the execution of an algorithm, and the retrieval of problem instances. This study examined the effects of age and repetition of problem instances on the production and verification of solutions to 2 serially presented sets of alphabet arithmetic problems. Analyses of the parameters derived from power-function fits for individuals revealed age differences favoring young adults in improvement span, learning rate, and asymptote. For both age groups, the beneficial effects of repetitions on 1st-set response times were attributable to algorithmic speedup and to the retrieval of instances, whereas improvements in the speed of 2nd-set response times were attributable primarily to item retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surface tension and mass density of liquid Cu–Ge alloys

We report a study on the mass density and surface tension of liquid Cu–Ge alloys in the temperature range between the liquidus line and 1373 K. The experiments have been carried out by means of the sessile-drop method. The temperature dependences of both properties are given in terms of linear relations for all alloys under investigation. Both, density and surface tension show remarkable deviations from linear mixing: The density is increased, and the surface tension reduced due to Ge acting as surfactant. The composition dependence of the surface tension is discussed in terms of a simple compound formation model which is well able to relate the results to previous findings on the short-range order of the alloys under investigation.     

The dynamic viscosity of liquid Cu–Si alloys

The dynamic viscosity of liquid Cu–Si alloys is measured in the Cu-rich composition range (up to 40 at.% Si). The Arrhenius-law describing the temperature dependence of the viscosity holds for all alloys investigated. The viscosity isotherms, both experimental and from thermodynamic model calculations, show a broad maximum covering the homogenity ranges of the intermetallic phases. An interconnection of such findings with the atomic structure of the liquid alloys is briefly discussed.     

Locally clocked pipelines and dynamic logic

Micropipelines and most of its variants use a delay-insensitive controller to moderate a pipeline. In search of improved performance, we depart from the delay-insensitive model in favor of a bounded-delay model for the controller. In particular, we demonstrate how a general delay-insensitive controller for level-sensitive pipelines can be improved by assuming a bounded-delay model and taking advantage of delay information to make the controller faster and more efficient. The new control scheme is referred to as locally clocked (LC) control. A highly pipelined logic technique called LC dynamic logic is presented that combines the bounded-delay controller for their comments and suggestions. with a latching dynamic logic gate design. Simulations comparing LC control with its delay-insensitive counterpart are presented. Also, an 8 × 8 bit multiplier with a maximum frequency of 715 MHz for a 1 μm CMOS process that uses LC dynamic logic is presented