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Inducing Mild Traumatic Brain Injury in C. elegans via Cavitation-Free Surface Acoustic Wave-Driven Ultrasonic Irradiation.
Mild traumatic brain injury is an all-too-common outcome from modern warfare and sport, and lacks a reproducible model for assessment of potential treatments and protection against it. Here we consider the use of surface acoustic wave (SAW) irradiation of C. elegans worms-without cavitation-as a potential, ethically reasonable animal-on-a-chip model for inducing traumatic brain injury in an animal, producing significant effects on memory and learning that could prove useful in a model that progress from youth to old age in but a few weeks. We show a significant effect by SAW on the ability of worms to learn post-exposure through associative learning chemotaxis. At higher SAW intensity, we find immediate, thorough, but temporary paralysis of the worms. We further explore the importance of homogeneous exposure of the worms to the SAW-driven ultrasound, an aspect poorly controlled in past efforts, if at all, and demonstrate the absence of cavitation through a change in fluids from a standard media for the worms to the exceedingly viscous polyvinyl alcohol. Likewise, we demonstrate that acoustic streaming, when present, is not directly responsible for paralysis nor learning disabilities induced in the worm, but is beneficial at low amplitudes to ensuring homogeneous ultrasound exposure
Dark matter in the classically conformal B-L model
When the classically conformal invariance is imposed on the minimal gauged
B-L extended Standard Model (SM), the B-L gauge symmetry is broken by the
Coleman-Weinberg mechanism naturally at the TeV scale. Introducing a new Z_2
parity in the model, we investigate phenomenology of a right-handed neutrino
dark matter whose stability is ensured by the parity. We find that the relic
abundance of the dark matter particle can be consistent with the observations
through annihilation processes enhanced by resonances of either the SM Higgs
boson, the B-L Higgs boson or the B-L gauge boson (Z' boson). Therefore, the
dark matter mass is close to half of one of these boson masses. Due to the
classically conformal invariance and the B-L gauge symmetry breaking via the
Coleman-Weinberg mechanism, Higgs boson masses, Z' boson mass and the dark
matter mass are all related, and we identify the mass region to be consistent
with experimental results. We also calculate the spin-independent cross section
of the dark matter particle off with nucleon and discuss implications for
future direct dark matter search experiments.Comment: 13 pages, 4 figure
Localization of massive fermions on the baby-skyrmion branes in 6 dimensions
We construct brane solutions in 6 dimensional Einstein-Skyrme systems. A
class of baby skyrmion solutions realizes warped compactification of the extra
dimensions and gravity localization on the brane for negative bulk cosmological
constant. Coupling of the fermions with the brane skyrmions lead to the brane
localized fermions. In terms of the level crossing picture, emergence of the
massive localized modes as well as the zero mode are observed. Nonlinear nature
of the skyrmions brings richer information for the fermions level structure.
The level comprises doubly degenerate lowest plus single excited modes. The
three generation of the fundamental fermions is based on this structure. The
quark/lepton mass hierarchy is successfully obtained in terms of a slightly
deformed baby-skyrmions with topological charge three.Comment: 16 pages, 17 figures. One figure added, some points clarified,
references improved. Version accepted for publicatio
Consideration for Affects of an XOR in a Random Number Generator Using Ring Oscillators
A cloud service to offer entropy has been paid much attention to. As one of the entropy sources, a physical random number generator is used as a true random number generator, relying on its irreproducibility. This paper focuses on a physical random number generator using a field-programmable gate array as an entropy source by employing ring oscillator circuits as a representative true random number generator. This paper investigates the effects of an XOR gate in the oscillation circuit by observing the output signal period. It aims to reveal the relationship between inputs and the output through the XOR gate in the target generator. The authors conduct two experiments to consider the relevance. It is confirmed that combining two ring oscillators with an XOR gate increases the complexity of the output cycle. In addition, verification using state transitions showed that the probability of the state transitions was evenly distributed by increasing the number of ring oscillator circuits
CTX: A Clock-Gating-Based Test Relaxation and X-Filling Scheme for Reducing Yield Loss Risk in At-Speed Scan Testing
At-speed scan testing is susceptible to yield loss risk due to power supply noise caused by excessive launch switching activity. This paper proposes a novel two-stage scheme, namely CTX (Clock-Gating-Based Test Relaxation and X-Filling), for reducing switching activity when test stimulus is launched. Test relaxation and X-filling are conducted (1) to make as many FFs inactive as possible by disabling corresponding clock-control signals of clock-gating circuitry in Stage-1 (Clock-Disabling), and (2) to make as many remaining active FFs as possible to have equal input and output values in Stage-2 (FF-Silencing). CTX effectively reduces launch switching activity, thus yield loss risk, even with a small number of donpsilat care (X) bits as in test compression, without any impact on test data volume, fault coverage, performance, and circuit design.2008 17th Asian Test Symposium (ATS 2008), 24-27 November 2008, Sapporo, Japa
Magnetic and axial vector form factors as probes of orbital angular momentum in the proton
We have recently examined the static properties of the baryon octet (magnetic
moments and axial vector coupling constants) in a generalized quark model in
which the angular momentum of a polarized nucleon is partly spin and partly orbital . The orbital momentum was
represented by the rotation of a flux-tube connecting the three constituent
quarks. The best fit is obtained with ,
. We now consider the consequences of this
idea for the -dependence of the magnetic and axial vector form factors. It
is found that the isovector magnetic form factor
differs in shape from the axial form factor by an amount that
depends on the spatial distribution of orbital angular momentum. The model of a
rigidly rotating flux-tube leads to a relation between the magnetic, axial
vector and matter radii, , where , . The shape of is found to be close to a dipole
with GeV.Comment: 18 pages, 5 ps-figures, uses RevTe
Predicting effects of climate change on productivity and persistence of forest trees
Global climate change increases uncertainty in sustained functioning of forest ecosystems. Forest canopies are a key link between terrestrial ecosystems, the atmosphere, and climate. Here, we introduce research presented at the 66th meeting of the Ecological Society of Japan in the symposium “Structure and function of forest canopies under climate change.” Old-growth forest carbon stores are the largest and may be the most vulnerable to climate change as the balance between sequestration and emission could easily be tipped. Detailed structural analysis of individual large, old trees shows they are allocating wood to the trunk and crown in patterns that cannot be deduced from ground, thus can be used to more accurately quantify total forest carbon and sequestration. Slowly migrating species sensitive to novel climatic conditions will have to acclimate at the individual level. Accounting for physiological responses of trees to climate change will improve predictions of future species distributions and subsequent functioning of forest ecosystems. Field experiments manipulating temperature and precipitation show how trees compensate physiologically to mitigate for higher temperatures and drought. However, it is difficult to measure acclimation responses over long timeframes. Intraindividual trait variation is proposed as an indicator of acclimation potential of trees to future conditions and suggests that acclimation potential may vary among regional populations within a species. Integrating whole-tree structural data with physiological data offers a promising avenue for understanding how trees will respond to climatic shifts
Uterine Carcinosarcoma in a 2-year-old Female Wistar Hannover GALAS Rat
Carcinosarcomas are rare tumors in humans as well as rats and most commonly occur in the
uterus. Recently, we observed a case of incidental carcinosarcoma of the uterus in a
female Wistar Hannover GALAS [BrlHan:WIST@ Jcl (GALAS)] rat at 2 years of age.
Histopathologically, the tumor was characterized by an admixture of malignant epithelial
and nonepithelial elements. The carcinomatous components represented a type of endometrial
carcinoma, consisting of glandular and solid proliferation of large-sized tumor cells.
Prominent mitoses and tumor cell invasion were observed. The sarcomatous components were
characterized by multifocal proliferation of severe atypical cells with cartilage matrix
and were diagnosed as chondrosarcoma. Transitions between carcinomatous and sarcomatous
components were observed, and many tumor cells in the solid lesion showed
immunohistochemical reactivity with both cytokeratin and vimentin. Based on these
findings, this tumor was diagnosed as a uterine carcinosarcoma. This is the first report
of uterine carcinosarcoma in Wistar Hannover GALAS [BrlHan:WIST@Jcl (GALAS)] rats
Forgeability of AZ Series Magnesium Alloy produced by Twin Roll Casting
Plastic forming of magnesium alloy is hardly reported because of its low forgeability. The productions of magnesium alloy are mainly produced by casting. Typical wrought magnesium alloy is AZ31. Magnesium-aluminum alloy indicates maximum elongation when the composition includes 3% aluminum. When the magnesium alloy includes over 3% aluminum, its elongation slightly decreases. Therefore, AZ31 that include 3% aluminum and 1% zinc is generally used for plastic forming. The more increasing aluminum composition, the larger 0.2% proof stress becomes. However its forgeability is decreasing because of precipitation of β phase such as Mg17Al12. It is supposed that the β phase is refined by rapid cooling casting process such as twin roll casting. In this paper, the magnesium alloy thick sheet of AZ91, AZ121 and AZ131 for hot forging, that include 9%, 12% and 13% aluminum composition respectively, was produced by twin roll strip casting process. And the forgeability of high aluminum containing magnesium alloy was investigated by die forging. As a result, it was possible to forge their magnesium alloys
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