Generating-function approach for bond percolations in hierarchical networks

We study bond percolations on hierarchical scale-free networks with the open bond probability of the shortcuts $\tilde{p}$ and that of the ordinary bonds $p$. The system has a critical phase in which the percolating probability $P$ takes an intermediate value $0<P<1$. Using generating function approach, we calculate the fractal exponent $\psi$ of the root clusters to show that $\psi$ varies continuously with $\tilde{p}$ in the critical phase. We confirm numerically that the distribution $n_s$ of cluster size $s$ in the critical phase obeys a power law $n_s \propto s^{-\tau}$, where $\tau$ satisfies the scaling relation $\tau=1+\psi^{-1}$. In addition the critical exponent $\beta(\tilde{p})$ of the order parameter varies as $\tilde{p}$, from $\beta\simeq 0.164694$ at $\tilde{p}=0$ to infinity at $\tilde{p}=\tilde{p}_c=5/32$.Comment: 8 pages, 8 figure

Oxygen reduction on bimodal nanoporous palladium-copper catalyst synthesized using sacrificial nanoporous copper

Nanoporous copper (NP-Cu), as a sacrificial support, was used for the synthesis of bimodal nanoporous palladium–copper (BNP-PdCu) for oxygen reduction reaction (ORR) electrodes in fuel cells. The catalytic performance of BNP-PdCu in ORR per electrochemical surface area was enhanced by the dissolution and removal of supporting NP-Cu, which indicates that the intrinsic catalytic properties of palladium are improved by the proposed synthesis strategy including galvanic replacement of copper with palladium, following copper dissolution. Cu remained on Pd surfaces even after dissolution of Cu. Additionally, significant local lattice contraction was observed at the ligament surface. First-principles calculations on the adsorbing oxygen species on Pd show that both lattice contraction and alloying with copper increase the binding energies of oxygen species to the Pd surface. The high ORR activity of the present BNP-PdCu is suggested to be mainly due to the Cu-ligand effect

Significantly high polarization degree of the very low-albedo asteroid (152679) 1998 KU2_\mathrm{2}

We present a unique and significant polarimetric result regarding the near-Earth asteroid (152679) 1998 KU$_\mathrm{2}$ , which has a very low geometric albedo. From our observations, we find that the linear polarization degrees of 1998 KU$_\mathrm{2}$ are 44.6 $\pm$ 0.5\% in the R$_\mathrm{C}$ band and 44.0 $\pm$ 0.6\% in the V band at a solar phase angle of 81.0\degr. These values are the highest of any known airless body in the solar system (i.e., high-polarization comets, asteroids, and planetary satellites) at similar phase angles. This polarimetric observation is not only the first for primitive asteroids at large phase angles, but also for low-albedo (< 0.1) airless bodies. Based on spectroscopic similarities and polarimetric measurements of materials that have been sorted by size in previous studies, we conjecture that 1998 KU$_\mathrm{2}$ has a highly microporous regolith structure comprising nano-sized carbon grains on the surface.Comment: 9 pages, 5 figures, and 3 tables, accepted for publication in A&

Positive feedback regulation of type I IFN genes by the IFN-inducible transcription factor IRF-7

AbstractThe interferon regulatory factor (IRF) family of transcription factors regulate the interferon (IFN) system, among which IRF-3 is involved in the virus-induced IFN-β gene expression. Here we show that another member IRF-7 is critical for the IFN-α gene induction. Unlike the IRF-3 gene, the IRF-7 gene is induced by IFNs through activation of the ISGF3 transcription factor, and IRF-7 undergoes virus-induced nuclear translocation. In cells lacking p48, an essential component of IFN stimulated gene factor 3 (ISGF3), ectopic expression of IRF-7 but not IRF-3 can rescue the deficiency to induce IFN-α genes. These results indicate that IRF-7 is a key factor in the positive feedback regulation of IFN-α/β production

Understanding the formation of maxillary sinus in Japanese human foetuses using cone beam CT

The formation of the maxillary sinus (MS) is tied to the maturation of the craniofacial bones during development. The MS and surrounding bone matrices in Japanese foetal specimens were inspected using cone beam computed tomography relative to the nasal cavity (NC) and the surrounding bones, including the palatine bone, maxillary process, inferior nasal concha and lacrimal bone. The human foetuses analysed were 223.2 ± 25.9 mm in crown-rump length (CRL) and ranged in estimated age from 20 to 30 weeks of gestation. The amount of bone in the maxilla surrounding the MS increased gradually between 20 and 30 weeks of gestation. Various calcified structures that formed the bone matrix were found in the cortical bone of the maxilla, and these calcified structures specifically surrounded the deciduous tooth germs. By 30 weeks of gestation, the uncinate process of the ethmoid bone formed a border with the maxilla. The distance from the midline to the maximum lateral surface border of the MS combined with the width from the midline to the maximum lateral surface border of the inferior nasal concha showed a high positive correlation with CRL in Japanese foetuses. There appears to be a complex correlation between the MS and NC formation during development in the Japanese foetus. Examination of the surrounding bone indicated that MS formation influences maturation of the maxilla and the uncinate process of the ethmoid bone during craniofacial bone development

Flower visitor fauna of the narrow endemic lily Lilium rubellum Baker in a lowland habitat in Yamagata, northern Japan

Floral visitor fauna of the narrow endemic lily Lilium rubellum was examined in a lowland habitat in Kaminoyama City, Yamagata Prefecture, northern Japan. Flowers of L. rubellum bloomed from early to late June. During 23 h of observing floral visitors, 64 insects were detected on L. rubellum flowers. Although coleopteran insects were most frequently found on L. rubellum flowers, they did not seem to be effective pollinators because of their body size. Bees were less frequently observed than coleopteran insects, but all individuals contacted sexual organs in L. rubellum flowers. Syrphid flies were seen less frequently, but they were also considered effective pollinators. From our observations, L. rubellum is a bee-pollinated species of the genus Lilium. Bee pollination has also been recorded in a species of Lilium sect. Archelirion, L. japonicum var. abeanum. The floral characteristics of L. japonicum var. abeanum (e.g., pinkish color, relatively small and tubular corolla, and lateral insertion of anthers into the corolla) were similar to those of L. rubellum and the character combination may be related to the bee-pollination mode in Lilium. key words： bee pollination, Bombus, Ceratina, flower visitor fauna, Lilium japonicum var. abeanum, Lilium rubellum, nitidulid beetle, syrphid fl

Effects of Melophlins on Colony Formation of Chinese Hamster V79 Cells and IL-8 Production in PMA-stimulated HL-60 Cells

We have recently isolated four new melophlins P (1), Q (2), R (3), and S (4) together with seven known melophlins A (5), D (6), E (7), G (8), H (9), I (10), and O (11) from two marine sponges of the genus Melophlus collected in Palau. In this study, the influence of these compounds on the colony formation of Chinese hamster V79 cells and the production of IL-8 in PMA-stimulated HL-60 cells were examined. These 11 compounds did not show any effect on IL-8 production. The EC50 values of compounds 2, 3, 4, 5, 7, 9, 10, and 11 against V79 cells were 44.0, 13.3, 16.7, 27.2, 19.8, 8.5, 23.1, and 9.6 μM, respectively. The linear-chain-type compounds (1, 6, and 8) were not active against V79 cells at 50 μM. Although the growth inhibitory activity of these melophlins was not remarkable, some structure-activity relationships of these compounds against V79 and murine leukemia L1210 cells were observed