31 research outputs found
Weak value amplification in a shot-noise limited interferometer
We study the weak-value amplification (WVA) in a phase measurement with an
optical interferometer in which shot noise limits the sensitivity. We compute
the signal and the shot noise including the full-order interaction terms of the
WVA, and show that the shot-noise contribution to a phase shift in a pointer
variable is always larger than the final variance of the pointer variable. This
yields difference in estimating noise level up to a factor of 1.5. To clarify
an advantage for practical uses of the WVA, we discuss signal-to-noise ratio
and its optimization in the presence of the shot noise.Comment: 6 pages, 4 figure
All-order evaluation of weak measurements: --- The cases of an operator which satisfies the property ---
Some exact formulae of the expectation values and probability densities in a
weak measurement for an operator which satisfies the property are derived. These formulae include all-order effects of the unitary
evolution due to the von-Neumann interaction. These are valid not only in the
weak measurement regime but also in the strong measurement regime and tell us
the connection between these two regime. Using these formulae, arguments of the
optimization of the signal amplification and the signal to noise ratio are
developed in two typical experimental setups.Comment: 17 pages, 10 figures (v1); Fig.3 and some typos are corrected (v2);
Comments and references are added and some typos are corrected (v3
The Japanese space gravitational wave antenna; DECIGO
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future
Japanese space gravitational wave antenna. DECIGO is expected to open a new window of
observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing
various mysteries of the universe such as dark energy, formation mechanism of supermassive
black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of
three drag-free spacecraft, whose relative displacements are measured by a differential Fabry–
Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-
DECIGO first and finally DECIGO in 2024
DECIGO pathfinder
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article
The 2G allele of promoter region of Matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinase (<it>MMP</it>) is known to be involved in the initial and progressive stages of cancer development, and in the aggressive phenotypes of cancer. This study examines the association of single nucleotide polymorphisms in promoter regions of <it>MMP-1 </it>and <it>MMP-3 </it>with susceptibility to oral squamous cell carcinoma (OSCC).</p> <p>Methods</p> <p>We compared 170 Japanese OSCC cases and 164 healthy controls for genotypes of <it>MMP-1 </it>and <it>MMP-3</it>.</p> <p>Results</p> <p>The frequency of the <it>MMP-1 </it>2G allele was higher and that of the 1G homozygote was lower in the OSCC cases (<it>p </it>= 0.034). A multivariate logistic regression analysis revealed that subjects who were 45 years old or older had a significantly increased (2.47-fold) risk of OSCC (95%CI 1.47–4.14, <it>p </it>= 0.0006), and those carrying the <it>MMP-1 </it>2G allele had a 2.30-fold risk (95%CI 1.15–4.58, <it>p </it>= 0.018), indicating independent involvement of these factors in OSCC. One of the key discoveries of this research is the apparent reduction of the <it>MMP-1 </it>1G/1G and 1G/2G genotype distributions among the early onset OSCC cases under the ages of 45 years. It should be noted that the tongue was the primary site in 86.2% of these early onset cases. This could suggest the specific carcinogenic mechanisms, i.e. specific carcinogenic stimulations and/or genetic factors in the tongue.</p> <p>Conclusion</p> <p>Since the 2G allele is a majority of the <it>MMP-1 </it>genotype in the general population, it seems to act as a genetic pre-condition in OSCC development. However this report suggests a crucial impact of the <it>MMP-1 </it>2G allele in the early onset OSCC.</p
Current status of space gravitational wave antenna DECIGO and B-DECIGO
Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the
future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO
aims at the detection of primordial gravitational waves, which could be
produced during the inflationary period right after the birth of the universe.
There are many other scientific objectives of DECIGO, including the direct
measurement of the acceleration of the expansion of the universe, and reliable
and accurate predictions of the timing and locations of neutron star/black hole
binary coalescences. DECIGO consists of four clusters of observatories placed
in the heliocentric orbit. Each cluster consists of three spacecraft, which
form three Fabry-Perot Michelson interferometers with an arm length of 1,000
km. Three clusters of DECIGO will be placed far from each other, and the fourth
cluster will be placed in the same position as one of the three clusters to
obtain the correlation signals for the detection of the primordial
gravitational waves. We plan to launch B-DECIGO, which is a scientific
pathfinder of DECIGO, before DECIGO in the 2030s to demonstrate the
technologies required for DECIGO, as well as to obtain fruitful scientific
results to further expand the multi-messenger astronomy.Comment: 10 pages, 3 figure
The status of DECIGO
DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present
Current status of space gravitational wave antenna DECIGO and B-DECIGO
The Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could have been produced during the inflationary period right after the birth of the Universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the Universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry–Pérot Michelson interferometers with an arm length of 1000 km. Three DECIGO clusters will be placed far from each other, and the fourth will be placed in the same position as one of the other three to obtain correlation signals for the detection of primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder for DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand multi-messenger astronomy