Weyl Invariance and Spurious Black Hole in Two-Dimensional Dilaton Gravity

In two-dimensional dilaton gravity theories, there may exist a global Weyl invariance which makes black hole spurious. If the global invariance and the local Weyl invariance of the matter coupling are intact at the quantum level, there is no Hawking radiation. We explicitly verify the absence of anomalies in these symmetries for the model proposed by Callan, Giddings, Harvey and Strominger. The crucial observation is that the conformal anomaly can be cohomologically trivial and so not truly anomalous in such dilaton gravity models.Comment: 28 pages, KANAZAWA-93-0

Carrier PNA for shRNA delivery into cells

A peptide nucleic acid (PNA)-cell-penetrating peptide (CPP) conjugate (carrier PNA) was used as 'bridgebuilder' to connect a CPP with an shRNA. The carrier PNA successfully formed a hybrid with an shRNA bearing complementary dangling bases and the shRNA was introduced into cells by the carrier PNA, and RNAi was induced by the shRNA

WARP : Revisiting GFN for Lightweight 128-bit Block Cipher

In this article, we present WARP, a lightweight 128-bit block cipher with a 128-bit key. It aims at small-footprint circuit in the field of 128-bit block ciphers, possibly for a unified encryption and decryption functionality. The overall structure of WARP is a variant of 32-nibble Type-2 Generalized Feistel Network (GFN), with a permutation over nibbles designed to optimize the security and efficiency. We conduct a thorough security analysis and report comprehensive hardware and software implementation results. Our hardware results show that WARP is the smallest 128-bit block cipher for most of typical hardware implementation strategies. A serialized circuit of WARP achieves around 800 Gate Equivalents (GEs), which is much smaller than previous state-of-the-art implementations of lightweight 128-bit ciphers (they need more than $1,000$ GEs). While our primary metric is hardware size, WARP also enjoys several other features, most notably low energy consumption. This is somewhat surprising, since GFN generally needs more rounds than substitution permutation network (SPN), and thus GFN has been considered to be less advantageous in this regard. We show a multi-round implementation of WARP is quite low-energy. Moreover, WARP also performs well on software: our SIMD implementation is quite competitive to known hardware-oriented 128-bit lightweight ciphers for long input, and even much better for small inputs due to the small number of parallel blocks. On 8-bit microcontrollers, the results of our assembly implementations show that WARP is flexible to achieve various performance characteristics

カンケイ ドウブツ アオゴカイ Perinereis aibuhitensis キョダイ ヘモグロビン ノ グロビンサ ニ フクマレル ケウナ SSケツゴウ

The extracellular hemoglobin (Hb) from the polychaete Perinereis aibuhitensis consists of four types of 144 globins and two types of 36 linker chains，having a molecular mass of about 3,500 kDa. There are two types of globin subunits: monomer chain a and disulfide-bondedt rimer AbB. The amino acid sequences of the four globin chains (a，A ，b ，B ) were already reported，previously (Yamanaka，M. et al. Natural Science Research of Tokushima University, 19, 63-92, 2005). The site of disulfide bonds in the globin subunits have been investigated. Each globin chain contains an intrachain disulfide bond between N-terminal and C-terminal Cys residues. In addition，the interchain disulfide bonds were found between chains A and b，and b and B. Therefore，it is elucidated that the chain b is situated at the center of disulfide-bonded trimer，such as A-b-B.The sites of disulfide-bonds determined all could be suitably fitted to the tree dimensional structure of each subunit in a model without stretching or twisting. It was also confirmed that there is no free Cys residue in Peinereis globins. The positions of Cys residues of Perinereis globin sequences were compared wIth those of other 27 chains derived from the homologous Hbs. Among 31 sequences，Cys residues were distributed in six sites. The sites 1 and 2 are located at the N-terminal region of amino acid sequences，the sItes 3 and 4 at the central region，and the sites 5 and 6 at C-terminal region. Furthermore，the Cys distribution was categorized into eight patterns. Perinereis Hb has four patterns I，IV，VII，VIII，be ing lack of the central sites 3 and 4. It should be noted that the pattern II includes the unique globins from Hbs of Lamellibrachia，Riftia and Oligobrachia that carry H2S to the symbiotic bacteria，suggesting that these globin chains might carry H2S in vivo. The phylogenetic tree of 31 globin chains derived from the giant Hbs is divided into two families A and B， as already poited out by us Previously. The family A indudes pattern I-V，whereas the family B includes V- VIII

Comparing serial X-ray crystallography and microcrystal electron diffraction (MicroED) as methods for routine structure determination from small macromolecular crystals.

Innovative new crystallographic methods are facilitating structural studies from ever smaller crystals of biological macromolecules. In particular, serial X-ray crystallography and microcrystal electron diffraction (MicroED) have emerged as useful methods for obtaining structural information from crystals on the nanometre to micrometre scale. Despite the utility of these methods, their implementation can often be difficult, as they present many challenges that are not encountered in traditional macromolecular crystallography experiments. Here, XFEL serial crystallography experiments and MicroED experiments using batch-grown microcrystals of the enzyme cyclophilin A are described. The results provide a roadmap for researchers hoping to design macromolecular microcrystallography experiments, and they highlight the strengths and weaknesses of the two methods. Specifically, we focus on how the different physical conditions imposed by the sample-preparation and delivery methods required for each type of experiment affect the crystal structure of the enzyme

Method for the quantitative evaluation of ecosystem services in coastal regions

Wetlands, tidal flats, seaweed beds, and coral reefs are valuable not only as habitats for many species, but also as places where people interact with the sea. Unfortunately, these areas have declined in recent years, so environmental improvement projects to conserve and restore them are being carried out across the world. In this study, we propose a method for quantifying ecosystem services, that is, useful for the proper maintenance and management of artificial tidal flats, a type of environmental improvement project. With this method, a conceptual model of the relationship between each service and related environmental factors in natural and social systems was created, and the relationships between services and environmental factors were clarified. The state of the environmental factors affecting each service was quantified, and the state of those factors was reflected in the evaluation value of the service. As a result, the method can identify which environmental factors need to be improved and if the goal is to increase the value of the targeted tidal flat. The method demonstrates an effective approach in environmental conservation for the restoration and preservation of coastal areas

Polycystic Kidney Disease in the Medaka (Oryzias latipes) pc Mutant Caused by a Mutation in the Gli-Similar3 (glis3) Gene

Polycystic kidney disease (PKD) is a common hereditary disease in humans. Recent studies have shown an increasing number of ciliary genes that are involved in the pathogenesis of PKD. In this study, the Gli-similar3 (glis3) gene was identified as the causal gene of the medaka pc mutant, a model of PKD. In the pc mutant, a transposon was found to be inserted into the fourth intron of the pc/glis3 gene, causing aberrant splicing of the pc/glis3 mRNA and thus a putatively truncated protein with a defective zinc finger domain. pc/glis3 mRNA is expressed in the epithelial cells of the renal tubules and ducts of the pronephros and mesonephros, and also in the pancreas. Antisense oligonucleotide-mediated knockdown of pc/glis3 resulted in cyst formation in the pronephric tubules of medaka fry. Although three other glis family members, glis1a, glis1b and glis2, were found in the medaka genome, none were expressed in the embryonic or larval kidney. In the pc mutant, the urine flow rate in the pronephros was significantly reduced, which was considered to be a direct cause of renal cyst formation. The cilia on the surface of the renal tubular epithelium were significantly shorter in the pc mutant than in wild-type, suggesting that shortened cilia resulted in a decrease in driving force and, in turn, a reduction in urine flow rate. Most importantly, EGFP-tagged pc/glis3 protein localized in primary cilia as well as in the nucleus when expressed in mouse renal epithelial cells, indicating a strong connection between pc/glis3 and ciliary function. Unlike human patients with GLIS3 mutations, the medaka pc mutant shows none of the symptoms of a pancreatic phenotype, such as impaired insulin expression and/or diabetes, suggesting that the pc mutant may be suitable for use as a kidney-specific model for human GLIS3 patients

Capturing structural changes of the S-1 to S-2 transition of photosystem II using time-resolved serial femtosecond crystallography

Photosystem II (PSII) catalyzes light-induced water oxidation through an S-i-state cycle, leading to the generation of di-oxygen, protons and electrons. Pumpprobe time-resolved serial femtosecond crystallography (TR-SFX) has been used to capture structural dynamics of light-sensitive proteins. In this approach, it is crucial to avoid light contamination in the samples when analyzing a particular reaction intermediate. Here, a method for determining a condition that avoids light contamination of the PSII microcrystals while minimizing sample consumption in TR-SFX is described. By swapping the pump and probe pulses with a very short delay between them, the structural changes that occur during the S-1-to-S-2 transition were examined and a boundary of the excitation region was accurately determined. With the sample flow rate and concomitant illumination conditions determined, the S-2-state structure of PSII could be analyzed at room temperature, revealing the structural changes that occur during the S-1-to-S-2 transition at ambient temperature. Though the structure of the manganese cluster was similar to previous studies, the behaviors of the water molecules in the two channels (O1 and O4 channels) were found to be different. By comparing with the previous studies performed at low temperature or with a different delay time, the possible channels for water inlet and structural changes important for the water-splitting reaction were revealed

Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin

X線自由電子レーザーを用いて、光照射によるチャネルロドプシンの構造変化の過程を捉えることに成功. 京都大学プレスリリース. 2021-03-26.Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore

Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA

X-ray free-electron lasers (XFELs) have opened new opportunities for timeresolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TRSFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals. Two types of injectors are used: one for extruding highly viscous samples such as lipidic cubic phase (LCP) and the other for pulsed liquid droplets. Under standard sample flow conditions from the viscous-sample injector, delay times from nanoseconds to tens of milliseconds are accessible, typical time scales required to study large protein conformational changes. A first demonstration of a TR-SFX experiment on bacteriorhodopsin in bicelle using a setup with a droplet-type injector is also presented.112Ysciescopu