2,780 research outputs found
B\,^1\Sigma^{+}_{u} and EF\,^{1}\Sigma^{+}_{g} level energies of D
Accurate absolute level energies of the B\,^1\Sigma^{+}_{u}, and
EF\,^{1}\Sigma^{+}_{g}, rovibrational quantum states of molecular
deuterium are derived by combining results from a Doppler-free two-photon laser
excitation study on several lines in the
(0,0) band, with results
from a Fourier-transform spectroscopic emission study on a low-pressure
hydrogen discharge. Level energy uncertainties as low as 0.0005 cm are
obtained for some low-lying E\,^{1}\Sigma^{+}_{g} inner-well rovibrational
levels, while uncertainties for higher-lying rovibrational levels and those of
the F\,^{1}\Sigma^{+}_{g} outer-well states are nominally 0.005 cm.
Level energies of B\,^1\Sigma^{+}_{u} rovibrational levels, for
and are determined at an accuracy of 0.001 cm. Computed
wavelengths of D Lyman transitions in the
B\,^1\Sigma^{+}_{u}-X\,^{1}\Sigma^{+}_{g} () bands are also tabulated
for future applications.Comment: appears in Journal of Molecular Spectroscopy (2014
New record of <i>Carapus dubius</i> (Carapidae) off Madagascar?
When checking the identification of the Carapidae in the MNHN collection (Muséum National d’Histoire Naturelle, Paris) a specimen of Eurypleuron owasianum (Matsubara, 1953) (MNHN 1992-0914) caught off Madagascar (20°S, 42°30’E) was found to be incorrectly identified. The specimen is vey close to Carapus dubius (Putnam, 1874), which is known from the Eastern Pacific (Markle and Olney, 1990)
Reclaiming human machine nature
Extending and modifying his domain of life by artifact production is one of
the main characteristics of humankind. From the first hominid, who used a wood
stick or a stone for extending his upper limbs and augmenting his gesture
strength, to current systems engineers who used technologies for augmenting
human cognition, perception and action, extending human body capabilities
remains a big issue. From more than fifty years cybernetics, computer and
cognitive sciences have imposed only one reductionist model of human machine
systems: cognitive systems. Inspired by philosophy, behaviorist psychology and
the information treatment metaphor, the cognitive system paradigm requires a
function view and a functional analysis in human systems design process.
According that design approach, human have been reduced to his metaphysical and
functional properties in a new dualism. Human body requirements have been left
to physical ergonomics or "physiology". With multidisciplinary convergence, the
issues of "human-machine" systems and "human artifacts" evolve. The loss of
biological and social boundaries between human organisms and interactive and
informational physical artifact questions the current engineering methods and
ergonomic design of cognitive systems. New developpment of human machine
systems for intensive care, human space activities or bio-engineering sytems
requires grounding human systems design on a renewed epistemological framework
for future human systems model and evidence based "bio-engineering". In that
context, reclaiming human factors, augmented human and human machine nature is
a necessityComment: Published in HCI International 2014, Heraklion : Greece (2014
Beyond inverse Ising model: structure of the analytical solution for a class of inverse problems
I consider the problem of deriving couplings of a statistical model from
measured correlations, a task which generalizes the well-known inverse Ising
problem. After reminding that such problem can be mapped on the one of
expressing the entropy of a system as a function of its corresponding
observables, I show the conditions under which this can be done without
resorting to iterative algorithms. I find that inverse problems are local (the
inverse Fisher information is sparse) whenever the corresponding models have a
factorized form, and the entropy can be split in a sum of small cluster
contributions. I illustrate these ideas through two examples (the Ising model
on a tree and the one-dimensional periodic chain with arbitrary order
interaction) and support the results with numerical simulations. The extension
of these methods to more general scenarios is finally discussed.Comment: 15 pages, 6 figure
Thrombospondin modulates melanoma--platelet interactions and melanoma tumour cell growth in vivo.
In this study we have investigated the role of thrombospondin (TSP) as a possible ligand playing a key role in human M3Da. melanoma cell interaction with platelets and in tumour growth. TSP is secreted (80 +/- 6 ng TSP 10(-6) cells) and bound to the surface of M3Da. cells via receptors different from CD36, as shown by biosynthetic labelling and immunofluorescence studies. The levels of TSP binding to M3Da. cells evaluated by binding studies, using an anti-TSP monoclonal antibody (MAb) (LYP8), shows 367,000 +/- 58,000 (mean +/- s.d.) LYP8 binding sites per cell with a dissociation constant (Kd) of 67 nM. TSP binding to M3Da. cells shows 400,000 +/- 50,000 TSP binding sites per cell with a Kd of 10 nM. The capacity of anti-TSP MAb (LYP8) to inhibit M3Da.-platelet interactions was followed on an aggregometer and evaluated by electron microscopy studies. The biological role of TSP binding to M3Da. cells was investigated by implanting subcutaneously the M3Da. cell line in nude mice and following the size and time of in vivo tumour growth. Reducing the availability or the functional level of TSP by using an anti-TSP MAb (LYP8) resulted in a significant decrease in platelet aggregates interacting with M3Da. melanoma cells. Using an enzyme-linked immunosorbent assay, purified alpha nu beta 3 was shown to bind TSP. Moreover, LYP8-coated M3Da. cells showed a reduced capacity to form tumours in vivo. M3Da. cells were observed to attach and spread on human platelet TSP-coated plastic wells. This attachment by M3Da. cells was inhibited in a similar way by LYP8 and an anti-alpha nu beta 3 MAb (LYP18). The results obtained in this study show that TSP secreted and bound to the surface of a human melanoma cell line (M3Da.) acts as a link between aggregated platelets and the M3Da. cell surface. Moreover, these results shows that TSP can modulate tumour growth in vivo. Reagents such as MAbs directed against TSP and peptides derived from TSP could not only be used as a new therapeutic approach in the control of tumour metastasis of melanoma, but may also contribute to elucidation of the role of TSP in cancer biology
Annexin A2 at the interface between F-actin and membranes enriched in phosphatidylinositol 4,5,-bisphosphate
AbstractVesicle rocketing has been used as a model system for understanding the dynamics of the membrane-associated F-actin cytoskeleton, but in many experimental systems is induced by persistent, non-physiological stimuli. Localised changes in the concentration of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) in membranes stimulate the recruitment of actin-remodelling proteins to their sites of action, regulate their activity and favour vesicle rocketing. The calcium and anionic phospholipid-binding protein annexin A2 is necessary for macropinocytic rocketing and has been shown to bind both PI(4,5)P2 and the barbed-ends of F-actin filaments. Here we show that annexin A2 localises to the comet tails which form constitutively in fibroblasts from patients with Lowe Syndrome. These fibroblasts are deficient in OCRL1, a phosphatidylinositol polyphosphate 5-phosphatase with specificity for PI(4,5)P2. We show that upon depletion of annexin A2 from these cells vesicle rocketing is reduced, and that this is also dependent upon PI(4,5)P2 formation. Annexin A2 co-localised with comet-tails induced by pervanadate and hyperosmotic shock in a basophilic cell line, and in an epithelial cell line upon activation of PKC. In vitro annexin A2 promoted comet formation in a bead-rocketing assay and was sufficient to link F-actin filaments to PI(4,5)P2 containing vesicles. These observations are consistent with a role for annexin A2 as an actin nucleator on PI(4,5)P2-enriched membranes
On Using High-Definition Body Worn Cameras for Face Recognition from a Distance
Recognition of human faces from a distance is highly desirable for law-enforcement. This paper evaluates the use of low-cost, high-definition (HD) body worn video cameras for face recognition from a distance. A comparison of HD vs. Standard-definition (SD) video for face recognition from a distance is presented. HD and SD videos of 20 subjects were acquired in different conditions and at varying distances. The evaluation uses three benchmark algorithms: Eigenfaces, Fisherfaces and Wavelet Transforms. The study indicates when gallery and probe images consist of faces captured from a distance, HD video result in better recognition accuracy, compared to SD video. This scenario resembles real-life conditions of video surveillance and law-enforcement activities. However, at a close range, face data obtained from SD video result in similar, if not better recognition accuracy than using HD face data of the same range
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