Synchronization by Reactive Coupling and Nonlinear Frequency Pulling

We present a detailed analysis of a model for the synchronization of nonlinear oscillators due to reactive coupling and nonlinear frequency pulling. We study the model for the mean field case of all-to-all coupling, deriving results for the initial onset of synchronization as the coupling or nonlinearity increase, and conditions for the existence of the completely synchronized state when all the oscillators evolve with the same frequency. Explicit results are derived for Lorentzian, triangular, and top-hat distributions of oscillator frequencies. Numerical simulations are used to construct complete phase diagrams for these distributions

Gravel is soil is gravel

Around 3.8 M ha of gravelly soil contributes to crop production in south west WA. Soil analysis and glasshouse experiments routinely take place in the absence of the ≥2 mm fraction. Typical processes include sample collection, air drying, and sieving (\u3c2 mm) prior to experimentation or analysis. The ≥2 mm fraction is discarded as it is often considered inert, acting as a soil volume diluent, and problematic for routine chemical analysis when intact because of size and representativeness. However, the literature cites that the ≥2 mm fraction may contribute positively to soil chemical, physical and biological properties

Validating and extending the national Better Fertiliser Decisions for Pasture critical values for phosphorus

Viable pasture based grazing systems in south-western Australia have been made possible over much of the landscape through input of nutrients to soils which were impoverished when first cleared. Initial dramatic increases in production stimulated subsequent applications of fertilisers, particularly phosphatic fertilisers, ever since. However, excessive fertiliser application can be tied to environmental impacts including the loss of phosphorus (P) to waterways impacting on water quality

Comparative analysis of ascorbic acid in human milk and infant formula using varied milk delivery systems

<p>Abstract</p> <p>Background</p> <p>The expression of human milk for later use is on the rise. Bottle systems are used to deliver the expressed milk. Research has shown that storage of both human milk and artificial baby milk, or infant formula, leads to a loss of ascorbic acid (commonly called Vitamin C). As milk is removed from the bottle during feeding and replaced by ambient air, it is unknown if loss of ascorbic acid occurs during the course of a feeding. The purpose of this study is to investigate the effect of the milk delivery system on levels of ascorbic acid in human milk and infant formula. The objectives are to 1) determine changes in ascorbic acid concentration during a 20 minute "feed," 2) determine if there is a difference in ascorbic acid concentration between delivery systems, and 3) evaluate if any differences are of clinical importance.</p> <p>Methods</p> <p>Commonly available bottles were used for comparison of bottle delivery systems. Mature human milk was standardized to 42 mg/L of ascorbic acid. Infant formula with iron and infant formula with docosahexanoic acid were used for the formula samples. Each sample was analyzed for ascorbic acid concentration at baseline (0), 5, 10, 15, and 20 minutes. Each collection of samples was completed in triplicate. Samples were analyzed for ascorbic acid using normal-phase high performance liquid chromatography.</p> <p>Results</p> <p>Ascorbic acid concentration declined in all bottle systems during testing, Differences between the bottle systems were noted. Ascorbic acid concentrations declined to less than 40% of recommended daily intake for infants in 4 of the bottles systems at the 20 minute sampling.</p> <p>Conclusion</p> <p>The bottle systems used in this study had measurable decreases in the mean concentration of ascorbic acid. More research is needed to determine if the observed decreases are related to lower plasma ascorbic acid concentration in infants exclusively bottle fed. The decrease of ascorbic acid concentration observed in both human milk and infant formula using varied milk delivery systems may be of clinical importance. For infants who rely solely on bottle feeds there may be increased risk of deficiency. Bottle shape, size, and venting should be considered.</p

Synchronization by Nonlinear Frequency Pulling

We analyze a model for the synchronization of nonlinear oscillators due to reactive coupling and nonlinear frequency pulling motivated by the physics of arrays of nanoscale oscillators. We study the model for the mean field case of all-to-all coupling, deriving results for the onset of synchronization as the coupling or nonlinearity increase, and the fully locked state when all the oscillators evolve with the same frequency

Data co-processing for extreme scale analysis level II ASC milestone (4745).

Exascale supercomputing will embody many revolutionary changes in the hardware and software of high-performance computing. A particularly pressing issue is gaining insight into the science behind the exascale computations. Power and I/O speed con- straints will fundamentally change current visualization and analysis work ows. A traditional post-processing work ow involves storing simulation results to disk and later retrieving them for visualization and data analysis. However, at exascale, scien- tists and analysts will need a range of options for moving data to persistent storage, as the current o ine or post-processing pipelines will not be able to capture the data necessary for data analysis of these extreme scale simulations. This Milestone explores two alternate work ows, characterized as in situ and in transit, and compares them. We nd each to have its own merits and faults, and we provide information to help pick the best option for a particular use

HANDS-ON EXPERIMENTATION IN THE FLUID MECHANICS CLASSROOM AS HOMEWORK WITH EFLUIDS.COM

ABSTRACT In an introductory fluid mechanics course, it is important for students to realize that the mathematical models they are deriving in class sometimes model the real world well and sometimes not so well. One way to demonstrate this is to have the students model a simple experiment and compare the results of the model to those of the experiment. This exercise teaches the importance of the model assumptions and the applicability of the model. It would be even more effective if the experiments were simple enough so that students could do them at home as a homework assignment, rather than restricting their experience to a &quot;canned&quot; two hour lab course. At eFluids.com, we are building a library of such experiments in an effort to build a community of educators that moves beyond the traditional mathematical exercises for homework. Here, we describe a number of these experiments and how they can be used in classes

BSE infectivity in jejunum, ileum and ileocaecal junction of incubating cattle

To establish bovine spongiform encephalopathy (BSE) public health protection measures it is important to precisely define the cattle tissues considered as specified risk materials (SRM). To date, in pre-clinical BSE infected cattle, no evidence of the BSE agent had been found in the gut outside of the ileal Peyer's Patches. This study was undertaken to determine when and where the pathological prion protein (PrPSc) and/or BSE infectivity can be found in the small intestine of cattle 4 to 6 months of age, orally challenged with BSE. Samples of the jejunum, the ileum and the ileocaecal junction from 46 BSE infected cattle, culled from 1 up to 44 months post infection (mpi) were examined by immunohistochemistry. Samples from cattle 8 mpi to 20 mpi were additionally studied by PTA Western blot, rapid tests, and by mouse (TgbovXV) bioassay. In doing so nearly all of the cattle, from 4 up to 44 mpi, had detectable amounts of PrPSc and/or infectivity in the distal ileum. In the distal ileum clear time-dependent variations were visible concerning the amount of PrPSc, the tissue structures affected, and the cells involved. BSE infectivity was found not only in the ileum and ileocaecal junction but also in the jejunum. The systematic approach of this study provides new data for qualitative and quantitative risk assessments and allows defining bovine SRM more precisely