Adaptive Predictive Control Using Neural Network for a Class of Pure-feedback Systems in Discrete-time

10.1109/TNN.2008.2000446IEEE Transactions on Neural Networks1991599-1614ITNN

The effect of cooling prior to and during exercise on exercise performance and capacity in the heat: a meta-analysis

Exercise is impaired in hot, compared to moderate, conditions. The development of hyperthermia is strongly linked to the impairment and as a result, many different strategies have been investigated to combat this. This meta-analysis focused on one of the most popular strategies: cooling. Pre-cooling has received the most attention but more recently cooling applied during the bout of exercise has also been investigated and both were reviewed. We conducted a literature search and retrieved twenty-eight articles which investigated the effect of cooling administered either prior to (n=23) or during (n=5) an exercise test in hot (WBGT >26°C) conditions. Mean and weighted effect sizes (Cohen’s d) were calculated. Overall, pre-cooling has a moderate (d=0.73) effect on subsequent performance but the magnitude of the effect is dependent upon the nature of the test. Sprint performance is impaired (d=-0.26) but intermittent performance and prolonged exercise are both improved following cooling (d=0.47 and d=1.91 respectively). Cooling during exercise also has a positive effect on performance and capacity (d=0.76). Improvements were observed in studies with and without cooling-induced physiological alterations and the literature supports the suggestion of a dose-response relationship between cooling, thermal strain and improvements in performance and capacity. In summary, pre-cooling can improve subsequent intermittent and prolonged exercise performance and capacity in a hot environment but sprint performance is impaired. Cooling during exercise also has a positive effect on exercise performance and capacity in a hot environment

Similarity theory and calculation of turbulent fluxes at the surface for the stably stratified atmospheric boundary layers

In this paper we revise the similarity theory for the stably stratified atmospheric boundary layer (ABL), formulate analytical approximations for the wind velocity and potential temperature profiles over the entire ABL, validate them against large-eddy simulation and observational data, and develop an improved surface flux calculation technique for use in operational models.Comment: The submission to a special issue of the Boundary-Layer Meteorology devoted to the NATO advanced research workshop Atmospheric Boundary Layers: Modelling and Applications for Environmental Securit

Pointlike probes of superstring-theoretic superfluids

In analogy with an experimental setup used in liquid helium, we use a pointlike probe to study superfluids which have a gravity dual. In the gravity description, the probe is represented by a hanging string. We demonstrate that there is a critical velocity below which the probe particle feels neither drag nor stochastic forces. Above this critical velocity, there is power-law scaling for the drag force, and the stochastic forces are characterized by a finite, velocity-dependent temperature. This temperature participates in two simple and general relations between the drag force and stochastic forces. The formula we derive for the critical velocity indicates that the low-energy excitations are massless, and they demonstrate the power of stringy methods in describing strongly coupled superfluids.Comment: 17 pages, 2 figures, added a figure, a reference, and moved material to an appendi

Quantum Critical Superfluid Flows and Anisotropic Domain Walls

We construct charged anisotropic AdS domain walls as solutions of a consistent truncation of type IIB string theory. These are a one-parameter family of solutions that flow to an AdS fixed point in the IR, exhibiting emergent conformal invariance and quantum criticality. They represent the zero-temperature limit of the holographic superfluids at finite superfluid velocity constructed in arXiv:1010.5777. We show that these domain walls exist only for velocities less than a critical value, agreeing in detail with a conjecture made there. We also comment about the IR limits of flows with velocities higher than this critical value, and point out an intriguing similarity between the phase diagrams of holographic superfluid flows and those of ordinary superconductors with imbalanced chemical potential.Comment: 11 pages, 3 figures. V2: Very minor corrections. JHEP versio

Robust Adaptive Control of a Class of Nonlinear Strict-feedback Discrete-time Systems with Exact Output Tracking

10.1016/j.automatica.2009.07.025Automatica45112537-2545ATCA

The [alpha/Fe] Ratios in Dwarf Galaxies: Evidence for a Non-universal Stellar Initial Mass Function?

It is well established that the [alpha/Fe] ratios in elliptical galaxies increase with galaxy mass. This relation holds also for early-type dwarf galaxies, although it seems to steepen at low masses. The [alpha/Fe] vs. mass relation can be explained assuming that smaller galaxies form over longer timescales (downsizing), allowing a larger amount of Fe (mostly produced by long-living Type Ia Supernovae) to be released and incorporated into newly forming stars. Another way to obtain the same result is by using a flatter initial mass function (IMF) in large galaxies, increasing in this way the number of Type II Supernovae and therefore the production rate of alpha-elements. The integrated galactic initial mass function (IGIMF) theory predicts that the higher the star formation rate, the flatter the IMF. We have checked, by means of semi-analytical calculations, that the IGIMF theory, combined with the downsizing effect (i.e. the shorter duration of the star formation in larger galaxies), well reproduces the observed [alpha/Fe] vs. mass relation. In particular, we show a steepening of this relation in dwarf galaxies, in accordance with the available observations.Comment: 4 pages, 2 figures; to appear in the proceedings of the JENAM 2010 Symposium on Dwarf Galaxies (Lisbon, September 9-10, 2010

Expert consensus for respiratory physiotherapy management of mechanically ventilated adults with community-acquired pneumonia: A Delphi study

Rationale and aims: Patients with community‐acquired pneumonia (CAP) are frequently admitted to an intensive care unit. Physiotherapy may be provided to optimize respiratory function; however, there is significant variability in clinical practice and limited research directing best practice for this cohort. This study aimed to determine expert consensus for best physiotherapy practice for invasively ventilated adults with CAP. Method: A modified Delphi technique involved an international expert panel completing three rounds of an online questionnaire. The initial 35‐statement questionnaire, based on a systematic literature review and survey of current clinical practice, covered physiotherapy assessment and treatment of intubated patients with CAP. Quantitative data using Likert scales determined level of agreement, with qualitative data collected through open‐ended responses. Consensus threshold was set a priori at 70%. Items not achieving consensus were modified and new items added based on themes from qualitative data. Quantitative data were analysed descriptively, with thematic analysis used on qualitative data. Results: The panel comprised 29 international clinical and academic experts in critical care physiotherapy. Response rate was more than 95% for each round. Outcome achieved was 38 consensus statements covering assessment and treatment, with 28 statements (74%) providing consensus on recommended clinical practice, two consensus disagreement statements (7%) for what practice is not recommended, and eight statements (21%) indicating which treatments may be beneficial. Conclusion: Expert consensus regarding physiotherapy for intubated adults with CAP patients provides an evidence‐based approach to guide clinical practice. The consensus statements can also be used to guide research evaluating physiotherapy interventions for patients with CAP