37,417 research outputs found
Applications of LANDSAT data to the integrated economic development of Mindoro, Phillipines
LANDSAT data is seen as providing essential up-to-date resource information for the planning process. LANDSAT data of Mindoro Island in the Philippines was processed to provide thematic maps showing patterns of agriculture, forest cover, terrain, wetlands and water turbidity. A hybrid approach using both supervised and unsupervised classification techniques resulted in 30 different scene classes which were subsequently color-coded and mapped at a scale of 1:250,000. In addition, intensive image analysis is being carried out in evaluating the images. The images, maps, and aerial statistics are being used to provide data to seven technical departments in planning the economic development of Mindoro. Multispectral aircraft imagery was collected to compliment the application of LANDSAT data and validate the classification results
Explicit computations of low lying eigenfunctions for the quantum trigonometric Calogero-Sutherland model related to the exceptional algebra E7
In the previous paper math-ph/0507015 we have studied the characters and
Clebsch-Gordan series for the exceptional Lie algebra E7 by relating them to
the quantum trigonometric Calogero-Sutherland Hamiltonian with coupling
constant K=1. Now we extend that approach to the case of general K
Modeling contact formation between atomic-sized gold tips via molecular dynamics
The formation and rupture of atomic-sized contacts is modelled by means of
molecular dynamics simulations. Such nano-contacts are realized in scanning
tunnelling microscope and mechanically controlled break junction experiments.
These instruments routinely measure the conductance across the nano-sized
electrodes as they are brought into contact and separated, permitting
conductance traces to be recorded that are plots of conductance versus the
distance between the electrodes. One interesting feature of the conductance
traces is that for some metals and geometric configurations a jump in the value
of the conductance is observed right before contact between the electrodes, a
phenomenon known as jump-to-contact. This paper considers, from a computational
point of view, the dynamics of contact between two gold nano-electrodes.
Repeated indentation of the two surfaces on each other is performed in two
crystallographic orientations of face-centred cubic gold, namely (001) and
(111). Ultimately, the intention is to identify the structures at the atomic
level at the moment of first contact between the surfaces, since the value of
the conductance is related to the minimum cross-section in the contact region.
Conductance values obtained in this way are determined using first principles
electronic transport calculations, with atomic configurations taken from the
molecular dynamics simulations serving as input structures.Comment: 6 pages, 4 figures, conference submissio
Role of Membrane GM1 on Early Neuronal Membrane Actions of Aβ During Onset of Alzheimer\u27s Disease
The ability of beta-amyloid peptide (Aβ) to disrupt the plasma membrane through formation of pores and membrane breakage has been previously described. However, the molecular determinants for these effects are largely unknown. In this study, we examined if the association and subsequent membrane perforation induced by Aβ was dependent on GM1levels. Pretreatment of hippocampal neurons with D-PDMP decreased GM1 and Aβ clustering at the membrane (Aβ fluorescent-punctas/20 μm, control = 16.2 ± 1.1 vs. D-PDMP = 6.4 ± 0.4, p \u3c 0.001). Interestingly, membrane perforation with Aβ occurred with a slower time course when the GM1 content was diminished (time to establish perforated configuration (TEPC) (min): control = 7.8 ± 2 vs. low GM1 = 12.1 ± 0.5, p \u3c 0.01), suggesting that the presence of GM1 in the membrane can modulate the distribution and the membrane perforation by Aβ. On the other hand, increasing GM1 facilitated the membrane perforation (TEPC: control = 7.8 ± 2 vs. GM1 = 6.2 ± 1 min, p \u3c 0.05). Additionally, using Cholera Toxin Subunit-B (CTB) to block the interaction of Aβ with GM1 attenuated membrane perforation significantly. Furthermore, pretreatment with CTB decreased the membrane association of Aβ (fluorescent-punctas/20 μm, Aβ: control = 14.8 ± 2.5 vs. CTB = 8 ± 1.4, p \u3c 0.05), suggesting that GM1 also plays a role in both association of Aβ with the membrane and in perforation. In addition, blockade of the Aβ association with CTB inhibited synaptotoxicity. Taken together, our results strongly suggest that membrane lipid composition can affect the ability of Aβ to associate and subsequently perforate the plasma membrane thereby modulating its neurotoxicity in hippocampal neurons
Large area pulse ionization chamber for measurement of extremely heavy cosmic rays
Parallel plate ionization chamber for identifying relativistic cosmic ray nucle
Infinitesimal Variations of Hodge Structure at Infinity
By analyzing the local and infinitesimal behavior of degenerating polarized
variations of Hodge structure the notion of infinitesimal variation of Hodge
structure at infinity is introduced. It is shown that all such structures can
be integrated to polarized variations of Hodge structure and that, conversely,
all are limits of infinitesimal variations of Hodge structure (IVHS) at finite
points. As an illustration of the rich information encoded in this new
structure, some instances of the maximal dimension problem for this type of
infinitesimal variation are presented and contrasted with the "classical" case
of IVHS at finite points
- …