Identification problems of muon and electron events in the Super-Kamiokande detector

In the measurement of atmospheric nu_e and nu_mu fluxes, the calculations of the Super Kamiokande group for the distinction between muon-like and electronlike events observed in the water Cerenkov detector have initially assumed a misidentification probability of less than 1 % and later 2 % for the sub-GeV range. In the multi-GeV range, they compared only the observed behaviors of ring patterns of muon and electron events, and claimed a 3 % mis-identification. However, the expressions and the calculation method do not include the fluctuation properties due to the stochastic nature of the processes which determine the expected number of photoelectrons (p.e.) produced by muons and electrons. Our full Monte Carlo (MC) simulations including the fluctuations of photoelectron production show that the total mis-identification rate for electrons and muons should be larger than or equal to 20 % for sub-GeV region. Even in the multi-GeV region we expect a mis-identification rate of several % based on our MC simulations taking into account the ring patterns. The mis-identified events are mostly of muonic origin.Comment: 17 pages, 12 figure

The Carnot Cycle for Small Systems: Irreversibility and the Cost of Operations

We employ the recently developed framework of the energetics of stochastic processes (called `stochastic energetics'), to re-analyze the Carnot cycle in detail, taking account of fluctuations, without taking the thermodynamic limit. We find that both processes of connection to and disconnection from heat baths and adiabatic processes that cause distortion of the energy distribution are sources of inevitable irreversibility within the cycle. Also, the so-called null-recurrence property of the cumulative efficiency of energy conversion over many cycles and the irreversible property of isolated, purely mechanical processes under external `macroscopic' operations are discussed in relation to the impossibility of a perpetual machine, or Maxwell's demon.Comment: 11 pages with 3 figures. Resubmitted to Physical Review E. Many paragraphs have been modifie

Apollo asteroids (1566) Icarus and 2007 MK6: Icarus family members?

Although it is more complicated to search for near-Earth object (NEO) families than main belt asteroid (MBA) families, since differential orbital evolution within a NEO family can cause current orbital elements to drastically differ from each other, we have found that Apollo asteroids (1566) Icarus and the newly discovered 2007 MK6 are almost certainly related. Specifically, their orbital evolutions show a similar profile, time shifted by only ~1000 yr, based on our time-lag theory. The dynamical relationship between Icarus and 2007 MK6 along with a possible dust band, the Taurid-Perseid meteor swarm, implies the first detection of an asteroidal NEO family, namely the "Icarus asteroid family".Comment: 11 pages, 1 figure, to appear on Astrophysical Journal Letters (journal info added

COMET 169P/NEAT(=2002 EX 12 ): THE PARENT BODY OF THE α-CAPRICORNID METEOROID STREAM

ABSTRACT The Jupiter-family comet 169P/NEAT (previously known as asteroid 2002 EX 12 ) has a dynamical association with the α-Capricornid meteoroid stream. In this paper, we present photometric observations of comet 169P/NEAT to further investigate the physical characters of its disintegration state related to the stream. The comet shows a point-like surface brightness profile limiting contamination due to coma emission to ∼4% at most, indicating no evidence of outgassing. An upper limit on the fraction of the surface that could be sublimating water ice of <10 −4 is obtained with an upper limit to the mass loss of ∼10 −2 kg s −1 . The effective radius of nucleus is found to be 2.3 ± 0.4 km. Red filter photometry yields a rotational period of 8.4096 ± 0.0012 hr, and the range of the amplitude 0.29 ± 0.02 mag is indicative of a moderately spherical shape having a projected axis ratio ∼1.3. The comet shows redder colors than the Sun, being compatible with other dead comet candidates. The calculated lost mass per revolution is ∼10 9 kg. If it has sustained this mass loss over the estimated 5000 yr age of the α-Capricornid meteoroid stream, the total mass loss from 169P/NEAT (∼10 13 kg) is consistent with the reported stream mass (∼ 10 13 -10 15 kg), suggesting that the stream is the product of steady disintegration of the parent at every return

Stability and Electronic Properties of TiO2 Nanostructures With and Without B and N Doping

We address one of the main challenges to TiO2-photocatalysis, namely band gap narrowing, by combining nanostructural changes with doping. With this aim we compare TiO2's electronic properties for small 0D clusters, 1D nanorods and nanotubes, 2D layers, and 3D surface and bulk phases using different approximations within density functional theory and GW calculations. In particular, we propose very small (R < 0.5 nm) but surprisingly stable nanotubes with promising properties. The nanotubes are initially formed from TiO2 layers with the PtO2 structure, with the smallest (2,2) nanotube relaxing to a rutile nanorod structure. We find that quantum confinement effects - as expected - generally lead to a widening of the energy gap. However, substitutional doping with boron or nitrogen is found to give rise to (meta-)stable structures and the introduction of dopant and mid-gap states which effectively reduce the band gap. Boron is seen to always give rise to n-type doping while depending on the local bonding geometry, nitrogen may give rise to n-type or p-type doping. For under coordinated TiO2 surface structures found in clusters, nanorods, nanotubes, layers and surfaces nitrogen gives rise to acceptor states while for larger clusters and bulk structures donor states are introduced

Shapes, contact angles, and line tensions of droplets on cylinders

Using an interface displacement model we calculate the shapes of nanometer-size liquid droplets on homogeneous cylindrical surfaces. We determine effective contact angles and line tensions, the latter defined as excess free energies per unit length associated with the two contact lines at the ends of the droplet. The dependences of these quantities on the cylinder radius and on the volume of the droplets are analyzed.Comment: 26 pages, RevTeX, 10 Figure

Relating the thermodynamic arrow of time to the causal arrow

Consider a Hamiltonian system that consists of a slow subsystem S and a fast subsystem F. The autonomous dynamics of S is driven by an effective Hamiltonian, but its thermodynamics is unexpected. We show that a well-defined thermodynamic arrow of time (second law) emerges for S whenever there is a well-defined causal arrow from S to F and the back-action is negligible. This is because the back-action of F on S is described by a non-globally Hamiltonian Born-Oppenheimer term that violates the Liouville theorem, and makes the second law inapplicable to S. If S and F are mixing, under the causal arrow condition they are described by microcanonic distributions P(S) and P(S|F). Their structure supports a causal inference principle proposed recently in machine learning.Comment: 10 page

Novel Methodology for Creating Macaque Retinas with Sortable Photoreceptors and Ganglion Cells

Purpose: The ability to generate macaque retinas with sortable cell populations would be of great benefit to both basic and translational studies of the primate retina. The purpose of our study was therefore to develop methods to achieve this goal by selectively labeling, in life, photoreceptors (PRs) and retinal ganglion cells (RGCs) with separate fluorescent markers. Methods: Labeling of macaque (Macaca fascicularis) PRs and RGCs was accomplished by subretinal delivery of AAV5-hGRK1-GFP, and retrograde transport of micro-ruby™ from the lateral geniculate nucleus, respectively. Retinas were anatomically separated into different regions. Dissociation conditions were optimized, and cells from each region underwent fluorescent activated cell sorting (FACS). Expression of retinal cell type- specific genes was assessed by quantitative real-time PCR to characterize isolated cell populations. Results: We show that macaque PRs and RGCs can be simultaneously labeled in-life and enriched populations isolated by FACS. Recovery from different retinal regions indicated efficient isolation/enrichment for PRs and RGCs, with the macula being particularly amendable to this technique. Conclusions: The methods and materials presented here allow for the identification of novel reagents designed to target retinal ganglion cells and/or photoreceptors in a species that is phylogenetically and anatomically similar to human. These techniques will enable screening of intravitreally- delivered AAV capsid libraries for variants with increased tropism for PRs and/or RGCs and the evaluation of vector tropism and/or cellular promoter activity of gene therapy vectors in a clinically relevant species

SMART-1 Impact Ground-based campaign

Based on predictions of impact magnitude and cloud ejecta dynamics, we organized a SMART-1 ground-based observation campaign to perform coordinated measurements of the impact. Results from the coordinated multi-site campaign will be discussed

Language vs individuals in cross-linguistic corpus typology

Published as a special publication of Language Documentation & Conservation (No. 25).Peer reviewe