10,447 research outputs found
Rotuma, a changing mobility, 1978-1983 : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Geography at Massey University
This work describes the changes in movement of people to and from Rotuma immediately before, and following, the establishment of an airport on the Island in May 1981. A sample survey was carried out during the middle of 1983 to gain field data. The dynamics of movement are investigated and the research examines whether any subsets within the Rotuman community had a higher or lower level of movement, by sex, age, religion, education or occupation during the period 1978-1983
Endocytic signaling in leaves and roots: same rules different players.
To take up proteins and other components required by the cell, cells internalize a portion of the plasma membrane (PM), which invaginates to form a closed vesicle within the cytoplasm in a process known as endocytosis. The major plant endocytic mechanism is mediated by clathrin, a protein that is necessary to generate a coated vesicle on the inner side of the PM. These vesicles bud away from the membrane generating a vesicle whose contents originated from outside of the cell and they can selectively concentrate or exclude compounds. The process is therefore of key importance to plant growth, development, signaling, polarity, and nutrient delivery. Rho family small GTPases are conserved molecular switches that function in many signaling events. Plants possess only a single Rho-like GTPase (ROP) family. ROPs are known to be involved in the control of cell polarity by regulating endocytosis. To contend with the high levels of regulation required for such processes, plants have evolved specific regulators, including the Rop-interactive CRIB motif-containing protein (RIC) effectors. Recent findings have demonstrated that ROP dynamics and the cytoskeleton (including actin microfilaments and microtubules) are interwoven. In this review, we summarize the current understanding of endocytosis in plants, with particular regard to the signaling pathways
Learning and comparing functional connectomes across subjects
Functional connectomes capture brain interactions via synchronized
fluctuations in the functional magnetic resonance imaging signal. If measured
during rest, they map the intrinsic functional architecture of the brain. With
task-driven experiments they represent integration mechanisms between
specialized brain areas. Analyzing their variability across subjects and
conditions can reveal markers of brain pathologies and mechanisms underlying
cognition. Methods of estimating functional connectomes from the imaging signal
have undergone rapid developments and the literature is full of diverse
strategies for comparing them. This review aims to clarify links across
functional-connectivity methods as well as to expose different steps to perform
a group study of functional connectomes
The calculation of expectations for classes of diffusion processes by Lie symmetry methods
This paper uses Lie symmetry methods to calculate certain expectations for a
large class of It\^{o} diffusions. We show that if the problem has sufficient
symmetry, then the problem of computing functionals of the form
can be reduced to evaluating a single
integral of known functions. Given a drift we determine the functions
for which the corresponding functional can be calculated by symmetry.
Conversely, given , we can determine precisely those drifts for which
the transition density and the functional may be computed by symmetry. Many
examples are presented to illustrate the method.Comment: Published in at http://dx.doi.org/10.1214/08-AAP534 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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Practical method for the determination of time step in non-orthogonal FDTD
The Non-Orthogonal FDTD algorithm is well-suited to the modelling of curved structures, however users of the technique frequently have difficulty determining an appropriate time step for the algorithm. This contribution presents a new method which is shown to be both a practical and reliable technique for determining the time step
On Explicit Probability Laws for Classes of Scalar Diffusions
This paper uses Lie symmetry group methods to obtain transition probability densities for scalar diffusions, where the diffusion coefficient is given by a power law. We will show that if the drift of the diffusion satisfies a certain family of Riccati equations, then it is possible to compute a generalized Laplace transform of the transition density for the process. Various explicit examples are provided. We also obtain fundamental solutions of the Kolmogorov forward equation for diffusions, which do not correspond to transition probability densities.Lie symmetry groups; fundamental solutions; transition probability densities, Ito diffusions
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