207 research outputs found
A theory of electric and magnetic birefringence in liquids
This article does not have an abstract
deep-orange and carnation define distinct stages in late endosomal biogenesis in Drosophila melanogaster
Endosomal degradation is severely impaired in primary hemocytes from larvae of eye color mutants of Drosophila. Using high resolution imaging and immunofluorescence microscopy in these cells, products of eye color genes, deep-orange (dor) and carnation (car), are localized to large multivesicular Rab7-positive late endosomes containing Golgi-derived enzymes. These structures mature into small sized Dor-negative, Car-positive structures, which subsequently fuse to form tubular lysosomes. Defective endosomal degradation in mutant alleles of dor results from a failure of Golgi-derived vesicles to fuse with morphologically arrested Rab7-positive large sized endosomes, which are, however, normally acidified and mature with wild-type kinetics. This locates the site of Dor function to fusion of Golgi-derived vesicles with the large Rab7-positive endocytic compartments. In contrast, endosomal degradation is not considerably affected in car1 mutant; fusion of Golgi-derived vesicles and maturation of large sized endosomes is normal. However, removal of Dor from small sized Car-positive endosomes is slowed, and subsequent fusion with tubular lysosomes is abolished. Overexpression of Dor in car1 mutant aggravates this defect, implicating Car in the removal of Dor from endosomes. This suggests that, in addition to an independent role in fusion with tubular lysosomes, the Sec1p homologue, Car, regulates Dor function
Climatic and terrain influence on acidity, exchangeable bases and cation exchange capacity in soils of coffee plantations of Karnataka
Transfer path based tyre absorption tests
The development process of a tyre usually involves a combination of simulation and testing techniques focused on characterizing acoustic/aerodynamic and vibrational phenomena. One of the acoustic phenomenon of interest is the absorption of the tyre, which affects the sound radiated. This properties is mainly related to local resonant effects, which can be changed by modifying the geometry of the tyre tread. A procedure is presented to determine the attenuation achieved due to a change in tyre tread configuration. The acoustic transfer path is measured from sound produced at one side of the tyre pavement contact area to the other. A miniature microphone and a small monopole with a known output have been developed to allow measurements inside the tyre grooves. Tyre sections with a circumferential groove only, as well as sections with additional side branches, have been evaluated
Operational modal analysis of a tyre using a PU probe based scanning technique
Tyre vibration can be studied with several experimental and simulation techniques. An important goal for a tyre manufacturer is to “tune” the resonant frequency of the tyre subsystem to reduce the structure-borne noise in the car interior. In this paper, a novel measurement technique is applied to determine the operational tyre deflection shapes under different conditions; i.e. free condition, loaded condition, and rolling condition. The vibrational behaviour of a tyre is studied using a PU probe, which comprises a sound pressure and a particle velocity sensor, and a scanning technique. The relative phase information is obtained using a static reference sensor. The experimental data can be used to validate simulated mode-shapes and resonant frequencies
On the analysis of the vibrational Boson peak and low-energy excitations in glasses
Implications of reduction procedures applied to the low energy part of the
vibrational density of states in glasses and supercooled liquids are considered
by advancing a detailed comparison between the excess - over the Debye limit -
vibrational density of states g(w) and the frequency-reduced representation
g(w)/w^2 usually referred to as the Boson peak. Analyzing representative
experimental data from inelastic neutron and Raman scattering we show that
reduction procedures distort to a great extent the otherwise symmetric excess
density of states. The frequency of the maximum and the intensity of the excess
experience dramatic changes; the former is reduced while the latter increases.
The frequency and the intensity of the Boson peak are also sensitive to the
distribution of the excess. In the light of the critical appraisal between the
two forms of the density of states (i.e. the excess and the frequency-reduced
one) we discuss changes of the Boson peak spectral features that are induced
under the presence of external stimuli such as temperature (quenching rate,
annealing), pressure, and irradiation. The majority of the Boson peak changes
induced by the presence of those stimuli can be reasonably traced back to
simple and expected modifications of the excess density of states and can be
quite satisfactorily accounted for the Euclidean random matrix theory.
Parallels to the heat capacity Boson peak are also briefly discussed.Comment: To appear in J. Non-Cryst. Solids (Proceedings of the 5th IDMRCS,
Lille, July 2005
Detector Description and Performance for the First Coincidence Observations between LIGO and GEO
For 17 days in August and September 2002, the LIGO and GEO interferometer
gravitational wave detectors were operated in coincidence to produce their
first data for scientific analysis. Although the detectors were still far from
their design sensitivity levels, the data can be used to place better upper
limits on the flux of gravitational waves incident on the earth than previous
direct measurements. This paper describes the instruments and the data in some
detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial
change
A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007
We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at
http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000
Stomach contents of cetaceans incidentally caught along Mangalore and Chennai coasts of India
Pharmacological separation of early afterdepolarizations from arrhythmogenic substrate in ΔKPQ Scn5a murine hearts modelling human long QT 3 syndrome
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