Spherical designs and modular forms of the D4D_4 lattice

In this paper, we study shells of the $D_4$ lattice with a slightly general concept of spherical $t$-designs due to Delsarte-Goethals-Seidel, namely, the spherical design of harmonic index $T$ (spherical $T$-design for short) introduced by Delsarte-Seidel. We first observe that the $2m$-shell of $D_4$ is an antipodal spherical $\{10,4,2\}$-design on the three dimensional sphere. We then prove that the $2$-shell, which is the $D_4$ root system, is tight $\{10,4,2\}$-design, using the linear programming method. The uniqueness of the $D_4$ root system as an antipodal spherical $\{10,4,2\}$-design with 24 points is shown. We give two applications of the uniqueness: a decomposition of the shells of the $D_4$ lattice in terms of orthogonal transformations of the $D_4$ root system: and the uniqueness of the $D_4$ lattice as an even integral lattice of level 2 in the four dimensional Euclidean space. We also reveal a connection between the harmonic strength of the shells of the $D_4$ lattice and non-vanishing of the Fourier coefficient of a certain newforms of level 2. Motivated by this, congruence relations for the Fourier coefficients are discussed

Public views of health insurance in Japan during the era of attaining universal health coverage: a secondary analysis of an opinion poll on health insurance in 1967

While Japan’s success in achieving universal health insurance over a short period with controlled healthcare costs has been studied from various perspectives, that of beneficiaries have been overlooked. We conducted a secondary analysis of an opinion poll on health insurance in 1967, immediately after reaching universal coverage. We found that people continued to face a slight barrier to healthcare access (26.8% felt medical expenses were a heavy burden) and had high expectations for health insurance (60.5% were satisfied with insured medical services and 82.4% were willing to pay a premium). In our study, younger age, having children before school age, lower living standards, and the health insurance scheme were factors that were associated with a willingness to pay premiums. Involving high-income groups in public insurance is considered to be the key to ensuring universal coverage of social insurance

Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier

The power consumption of a conventional photoreceiver is dominated by that of the electric amplifier connected to the photodetector (PD). An ultralow-capacitance PD can overcome this limitation, because it can generate sufficiently large voltage without an amplifier when combined with a high-impedance load. In this work, we demonstrate an ultracompact InGaAs PD based on a photonic crystal waveguide with a length of only 1.7 μm and a capacitance of less than 1 fF. Despite the small size of the device, a high responsivity of 1 A/W and a clear 40 Gbit/s eye diagram are observed, overcoming the conventional trade-off between size and responsivity. A resistor-loaded PD was actually fabricated for light-to-voltage conversion, and a kilo-volt/watt efficiency with a gigahertz bandwidth even without amplifiers was measured with an electro-optic probe. Combined experimental and theoretical results reveal that a bandwidth in excess of 10 GHz can be expected, leading to an ultralow energy consumption of less than 1 fJ/bit for the photoreceiver. Amplifier-less PDs with attractive performance levels are therefore feasible and a step toward a densely integrated photonic network/processor on a chip

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

Most of the highly efficient luminescent silicon nanocrystals (SiNCs) reported to date consist of organically capped silicon cores. Here, we report a method of obtaining Si/SiO2 core/shell nanoparticles emitting at a peak energy of 1.5 eV with very high quantum yields (53–61%). The same method led to quantum yields of ~30% for porous silicon powder emitting at 1.9 eV. The SiNCs were very stable under continuous excitation for several hours. The lifetime at 1.5 eV was over 232 μs, the longest ever reported for SiNCs, consistent with the very high luminescence efficiency. The SiNCs were first fabricated by non-thermal plasma synthesis or anodization in the case of porous silicon. Then, a thin oxide shell (~1 nm) was grown using high-pressure water vapor annealing. This oxidation process allows for the growth of very good quality oxide with low defect concentration and low stress, resulting in very good surface passivation, which explains the very high quantum yields obtained

Visualizing Trimming Dependence of Biodistribution and Kinetics with Homo- and Heterogeneous N-Glycoclusters on Fluorescent Albumin

A series of N-glycans, each sequentially trimmed from biantennary sialoglycans, were homo- or heterogeneously clustered efficiently on fluorescent albumin using a method that combined strain-promoted alkyne-azide cyclization and 6π-azaelectrocyclization. Noninvasive in vivo kinetics and dissection analysis revealed, for the first time, a glycan-dependent shift from urinary to gall bladder excretion mediated by sequential trimming of non-reducing end sialic acids. N-glycoalbumins that were trimmed further, in particular, GlcNAc- and hybrid biantennary-terminated congeners, were selectively taken up by sinusoidal endothelial and stellate cells in the liver, which are critical for diagnosis and treatment of liver fibrillation. Our glycocluster strategy can not only reveal the previously unexplored extracellular functions of N-glycan trimming, but will be classified as the newly emerging glycoprobes for diagnostic and therapeutic applications

PetaFlow: a global computing-networking-visualisation unitwith social impact

International audienceThe PetaFlow application aims to contribute to the use of high performance computational resources forthe benefit of society. To this goal the emergence of adequate information and communication technologies withrespect to high performance computing-networking-visualisation and their mutual awareness is required. Thedeveloped technology and algorithms are presented and applied to a real global peta-scale data intensive scientificproblem with social and medical importance, i.e. human upper airflow modelling

Charged Vortices in High Temperature Superconductors Probed by NMR

We report a first experimental evidence that a vortex in the high temperature superconductors (HTSC) traps a finite electric charge from the high resolution measurements of the nuclear quadrupole frequencies. In slightly overdoped YBa_2Cu_3O_7 the vortex is negatively charged by trapping electrons, while in underdoped YBa_2Cu_4O_8 it is positively charged by expelling electrons. The sign of the trapped charge is opposite to the sign predicted by the conventional BCS theory. Moreover, in both materials, the deviation of the magnitude of the charge from the theory is also significant. These unexpected features can be attributed to the novel electronic structure of the vortex in HTSC.Comment: 6 pages, 7 figures, to be published in Phys Rev.

Precise Measurement of Cosmic-Ray Proton and Helium Spectra with the BESS Spectrometer

We report cosmic-ray proton and helium spectra in energy ranges of 1 to 120 GeV and 1 to 54 GeV/nucleon, respectively, measured by a balloon flight of the BESS spectrometer in 1998. The magnetic-rigidity of the cosmic-rays was reliably determined by highly precise measurement of the circular track in a uniform solenoidal magnetic field of 1 Tesla. Those spectra were determined within overall uncertainties of +-5 % for protons and +- 10 % for helium nuclei including statistical and systematic errors.Comment: 12 pages, 4 figure