2,913 research outputs found
Identifying Finite-Time Coherent Sets from Limited Quantities of Lagrangian Data
A data-driven procedure for identifying the dominant transport barriers in a
time-varying flow from limited quantities of Lagrangian data is presented. Our
approach partitions state space into pairs of coherent sets, which are sets of
initial conditions chosen to minimize the number of trajectories that "leak"
from one set to the other under the influence of a stochastic flow field during
a pre-specified interval in time. In practice, this partition is computed by
posing an optimization problem, which once solved, yields a pair of functions
whose signs determine set membership. From prior experience with synthetic,
"data rich" test problems and conceptually related methods based on
approximations of the Perron-Frobenius operator, we observe that the functions
of interest typically appear to be smooth. As a result, given a fixed amount of
data our approach, which can use sets of globally supported basis functions,
has the potential to more accurately approximate the desired functions than
other functions tailored to use compactly supported indicator functions. This
difference enables our approach to produce effective approximations of pairs of
coherent sets in problems with relatively limited quantities of Lagrangian
data, which is usually the case with real geophysical data. We apply this
method to three examples of increasing complexity: the first is the double
gyre, the second is the Bickley Jet, and the third is data from numerically
simulated drifters in the Sulu Sea.Comment: 14 pages, 7 figure
Central wheatbelt grain legume development extension program : fieldpeas and lupins
The project aims to:
1) Collect integrate and extend to advisers, farmers and industry representatives technical information on field pea growing systems to optimize profit and reduce new enterprise failure risks.
2) Collect market and process information (prices and demand) for all types of field pea products, and to advise industry representatives and growers on the best options for the continued development of the field pea industry.
3) Identify areas within the field pea industry which require immediate research and industry action.
4) Conduct a field research programme on field pea agronomy within the central medium and high rainfall areas of the W.A. wheatbelt
Extracellular vesicle signatures and protein citrullination are modified in shore crabs (Carcinus maenas) infected with Hematodinium sp
Epizootiologists recurrently encounter symbionts and pathobionts in the haemolymph (blood equivalent) of shellfish. One such group is the dinoflagellate genus , which contains several species that cause debilitating disease in decapod crustaceans. The shore crab acts as a mobile reservoir of microparasites, including sp., thereby posing a risk to other co-located commercially important species, e.g. velvet crabs ( ). Despite the widespread prevalence and documented seasonality of infection dynamics, there is a knowledge gap regarding host-pathogen antibiosis, namely, how avoids the host's immune defences. Herein, we interrogated the haemolymph of -positive and -negative crabs for extracellular vesicle (EV) profiles (a proxy for cellular communication), alongside proteomic signatures for post-translational citrullination/deimination performed by arginine deiminases, which can infer a pathologic state. Circulating EV numbers in parasitized crab haemolymph were reduced significantly, accompanied by smaller EV modal size profiles (albeit non-significantly) when compared to -negative controls. Differences were observed for citrullinated/deiminated target proteins in the haemolymph between the parasitized and control crabs, with fewer hits identified overall in the former. Three deiminated proteins specific to parasitized crab haemolymph were actin, Down syndrome cell adhesion molecule (DSCAM), and nitric oxide synthase - factors that contribute to innate immunity. We report, for the first time, sp. could interfere with EV biogenesis, and that protein deimination is a putative mechanism of immune-modulation in crustacean- interactions
Simultaneous complementary idiotypic responses: absence of reciprocal regulation
Complementary antibodies, i.e. antibodies having combining site structures which are at least partially directed against each other, were induced in A/He mice by immunization with phosphorylcholine (Pc) coupled to keyhole limpet hemocyanin or with the Pc-binding IgA myeloma protein, HOPC-8 (H8). Both responses were monitored by enumerating plaque-forming cells and assaying serum antibody levels to Pc and H8. Prior immunization with H8 markedly suppressed subsequent immunization with Pc and vice versa; neither plaque-forming cell response was diminished, however, when mice were immunized simultaneously with Pc and H8. Experiments were designed to determine if the absence of reciprocal regulation was due to change in idiotypes. This was determined by measuring inhibition of plaque formation using complementary antibody. Plaque formation by cells was equally inhibited by high dilutions of the appropriate complementary antibody whether cells were from mice immunized with one, the other, or both antigens. Thus, the absence of regulation could not be accounted for by emergence of different idiotypes. Interestingly, sera from mice immunized to have high responses to both antigens were relatively ineffective in inhibiting plaque formation or suppressing immunization to Pc. However, such sera contained complexes of the complementary antibodies; apparently antibody to Pc in such sera quenches or neutralizes the activity of anti-H8 antibody. But the formation of complexes, at least measurable levels of circulating complexes, must be a result rather than the cause for the absence of reciprocal regulation, since regulation was also absent when immunization to Pc was manipulated so that responses were too low to result in detectable levels of circulating antibody to Pc. It is proposed that simultaneous complementary responses may occur in nature to other antigens and antibodies, and that such simultaneous responses may cause pathologic changes
On the decay of deformed actinide nuclei
decay through a deformed potential barrier produces significant
mixing of angular momenta when mapped from the nuclear interior to the outside.
Using experimental branching ratios and either semi-classical or
coupled-channels transmission matrices, we have found that there is a set of
internal amplitudes which are essentially constant for all even--even actinide
nuclei. These same amplitudes also give good results for the known anisotropic
particle emission of the favored decays of odd nuclei in the same mass
region.
PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures
uuencoded gz-compressed .tar file To appear in Physical Review Letter
Building a Spiking Neural Network Model of the Basal Ganglia on SpiNNaker
We present a biologically-inspired and scalable model of the Basal Ganglia (BG) simulated on the SpiNNaker machine, a biologically-inspired low-power hardware platform allowing parallel, asynchronous computing. Our BG model consists of six cell populations, where the neuro-computational unit is a conductance-based Izhikevich spiking neuron; the number of neurons in each population is proportional to that reported in anatomical literature. This model is treated as a single-channel of action-selection in the BG, and is scaled-up to three channels with lateral cross-channel connections. When tested with two competing inputs, this three-channel model demonstrates action-selection behaviour. The SpiNNaker-based model is mapped exactly on to SpineML running on a conventional computer; both model responses show functional and qualitative similarity, thus validating the usability of SpiNNaker for simulating biologically-plausible networks. Furthermore, the SpiNNaker-based model simulates in real time for time-steps 1 ms; power dissipated during model execution is & #x2248;1.8 W
Future eDestination Marketing: Perspective of an Australian Tourism Stakeholder Network.
Tourism destinations are difficult to manage because of the complex relationships of their diverse public and private stakeholders. At the same time, strategic marketing efforts are important for destinations to foster positive consequences of tourism, particularly given the range of opportunities and challenges created by the emergence of social media that destinations can use advantageously. This article aims to explore future eDestination marketing from Australian tourism stakeholder network perspectives. Workshops were convened in July 2012 in Melbourne, Australia, for select stakeholders invited to contribute to the futures national tourism technology strategy. They presented a stakeholder network approach to futures strategy development that aims to contribute to that used in recent national tourism plans and strategies for Australia developed by the government. Building on theories of stakeholder networks and futures, the article demonstrates the value of a futures stakeholder network method compared to traditional government approaches by critically analyzing outcomes of both
Molecular cytogenetic characterization of breakpoints in 19 patients with hematologic malignancies and 12p unbalanced translocations
Structural rearrangements of the short arm of chromosome 12 are frequent cytogenetic findings in various hematologic malignancies. The ETV6 gene is the most common target for rearrangements in 12p13. Fluorescence in situ hybridization (FISH) investigations have shown that translocations of 12p other than t(12;21) are frequently accompanied by small interstitial deletions that include ETV6. Unbalanced translocations involving ETV6 have rarely been described, and breakpoints outside ETV6 appear to be strongly associated with complex karyotypes. We studied bone marrow samples from 19 patients known to have 12p unbalanced translocations and complex karyotypes, using FISH and spectral karyotyping. FISH analysis confirmed the hemizygous deletion of the ETV6 and CDKN1B genes in 74% of cases. We found four cases with interstitial deletions. In these four cases and in two others (6/19, 31.5%), the fusion with the partner chromosome was in the subtelomeric region of 12p13.3, confirming that there is a recurrent breakpoint in this region
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