Enhancement of Glossiness Perception by Retinal-Image Motion: Additional Effect of Head-Yoked Motion Parallax

It has been argued that when an observer moves, a contingent retinal-image motion of a stimulus would strengthen the perceived glossiness. This would be attributed to the veridical perception of three-dimensional structure by motion parallax. However, it has not been investigated whether the effect of motion parallax is more than that of retinal-image motion of the stimulus. Using a magnitude estimation method, we examine in this paper whether cross-modal coordination of the stimulus change and the observer''s motion (i.e., motion parallax) is essential or the retinal-image motion alone is sufficient for enhancing the perceived glossiness. Our data show that a retinal-image motion simulating motion parallax without head motion strengthened the perceived glossiness but that its effect was weaker than that of motion parallax with head motion. These results suggest the existence of an additional effect of the cross-modal coordination between vision and proprioception on glossiness perception. That is, motion parallax enhances the perception of glossiness, in addition to retinal-image motions of specular surfaces.     

Application of light-cured dental adhesive resin for mounting electrodes or microdialysis probes in chronic experiments

In chronic recording experiments, self-curing dental acrylic resins have been used as a mounting base of electrodes or microdialysis-probes. Since these acrylics do not bond to the bone, screws have been used as anchors. However, in small experimental animals like finches or mouse, their craniums are very fragile and can not successfully hold the anchors. In this report, we propose a new application of light-curing dental resins for mounting base of electrodes or microdialysis probes in chronic experiments. This material allows direct bonding to the cranium. Therefore, anchor screws are not required and surgical field can be reduced considerably. Past experiences show that the bonding effect maintains more than 2 months. Conventional resin's window of time when the materials are pliable and workable is a few minutes. However, the window of working time for these dental adhesives is significantly wider and adjustable.     

Environmental DNA monitoring method of the commercially important and endangered fish Gnathopogon caerulescens

Limnology - Gnathopogon caerulescens is an endangered but commercially important fish in Lake Biwa, Japan. The population size of G. caerulescens has drastically reduced in the past decades, and...     

Production and characterization of recombinant P1 adhesin essential for adhesion,gliding, and antigenic variation in the human pathogenic bacterium,Mycoplasma pneumoniae

Mycoplasma pneumoniae forms an attachment organelle at one cell pole, binds to the host cell surface, and glides via a unique mechanism. A 170-kDa protein, P1 adhesin, present on the organelle surface plays a critical role in the binding and gliding process. In this study, we obtained a recombinant P1 adhesin comprising 1476 amino acid residues, excluding the C-terminal domain of 109 amino acids that carried the transmembrane segment, that were fused to additional 17 amino acid residues carrying a hexa-histidine (6?×?His) tag using an Escherichia coli expression system. The recombinant protein showed solubility, and chirality in circular dichroism (CD). The results of analytical gel filtration, ultracentrifugation, negative-staining electron microscopy, and small-angle X-ray scattering (SAXS) showed that the recombinant protein exists in a monomeric form with a uniformly folded structure. SAXS analysis suggested the presence of a compact and ellipsoidal structure rather than random or molten globule-like conformation. Structure model based on SAXS results fitted well with the corresponding structure obtained with cryo-electron tomography from a closely related species, M. genitalium. This recombinant protein may be useful for structural and functional studies as well as for the preparation of antibodies for medical applications.     

Isolation of Aspergillus caninus (Synonym: Phialosimplex caninus) from a Canine Iliac Lymph node

Mycopathologia - Aspergillus caninus (synonym: Phialosimplex caninus) is an anamorphic fungus species associated with systemic infections in dogs that has been transferred from the genus...     

Cloning and Sequencing of the Spore Germination Gene of Bacillus megaterium ATCC 12872: Similarities to the NaH-Antiporter Gene of Enterococcus hirae

The germination mutant TM-31 of Bacillus megaterium ATCC 12872, was isolated by transposon Tn917 insertional mutagenesis. Glucose, L -proline, L -leucine and KNO₃ germinated TM-31 poorly. The DNA in the region of the Tn917 insertion was cloned, and its nucleotide sequence determined. One major open reading frame was present on the cloned DNA. The hydrophobic protein encoded is presumably membrane-associated. A homology search revealed that the gene encoded in the region of the Tn917 insertion is homologous to napA of Enterococcus hirae. napA codes for the NaH-antiporter. It is hypothesized that transport of cations must play an important role in spore germination in B. megaterium ATCC 12872.     

Eutrophication of mountain lakes in Japan due to increasing deposition of anthropogenically produced dust

Atmospheric dust has wide-reaching effects, not only influencing climate conditions, but also ecosystems. The eastern region of the Asian continent is one of the largest emitters of dust in the world, and recent economic growth in the region has been accompanied by an increase in anthropogenic emissions. However, the effects of increased Asian dusts on aquatic ecosystems are not well understood. We examined fossil pigments and zooplankton remains from ²¹⁰Pb-dated sediments taken from high mountain lakes of Hourai-Numa and Hachiman-Numa, located in the Towada-Hachimantai National Park of Japan Islands, to uncover historical changes in the phyto- and zooplankton community over the past 100?years. Simultaneously, we measured the geochemical variables of TOC, TN, TP, ??¹³C, ??¹⁵N, and lead isotopes (²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb) in the sediments to identify environmental factors causing such changes. As a result, despite few anthropogenic activities in the watersheds, alpine lakes in Japan had increased algal and herbivore plankton biomasses by 3?C6 fold for recent years depending on the surrounding terrestrial vegetation and landscape conditions. Biological and biogeochemical proxies recorded from the lake sediments showed that this eutrophication occurred after the 1990s when P deposition increased as a result of atmospheric loading of dust transported from the Asian continent. The continued increase of anthropogenically produced dust may therefore impart damaging impacts on mountain ecosystems even if they are protected from direct anthropogenic disturbances.     

Comparative studies on the functional roles of N- and C-terminal regions of molluskan and vertebrate troponin-I

Vertebrate troponin regulates muscle contraction through alternative binding of the C-terminal region of the inhibitory subunit, troponin-I (TnI), to actin or troponin-C (TnC) in a Ca(2+)-dependent manner. To elucidate the molecular mechanisms of this regulation by molluskan troponin, we compared the functional properties of the recombinant fragments of Akazara scallop TnI and rabbit fast skeletal TnI. The C-terminal fragment of Akazara scallop TnI (ATnI(232-292)), which contains the inhibitory region (residues 104-115 of rabbit TnI) and the regulatory TnC-binding site (residues 116-131), bound actin-tropomyosin and inhibited actomyosin-tropomyosin Mg-ATPase. However, it did not interact with TnC, even in the presence of Ca(2+). These results indicated that the mechanism involved in the alternative binding of this region was not observed in molluskan troponin. On the other hand, ATnI(130-252), which contains the structural TnC-binding site (residues 1-30 of rabbit TnI) and the inhibitory region, bound strongly to both actin and TnC. Moreover, the ternary complex consisting of this fragment, troponin-T, and TnC activated the ATPase in a Ca(2+)-dependent manner almost as effectively as intact Akazara scallop troponin. Therefore, Akazara scallop troponin regulates the contraction through the activating mechanisms that involve the region spanning from the structural TnC-binding site to the inhibitory region of TnI. Together with the observation that corresponding rabbit TnI-fragment (RTnI(1-116)) shows similar activating effects, these findings suggest the importance of the TnI N-terminal region not only for maintaining the structural integrity of troponin complex but also for Ca(2+)-dependent activation.     

Influence of the Cytoplasmic Domains of Aquaporin-4 on Water Conduction and Array Formation

Phosphorylation of Ser180 in cytoplasmic loop D has been shown to reduce the water permeability of aquaporin (AQP) 4, the predominant water channel in the brain. However, when the structure of the S180D mutant (AQP4M23S180D), which was generated to mimic phosphorylated Ser180, was determined to 2.8 Å resolution using electron diffraction patterns, it showed no significant differences from the structure of the wild-type channel. High-resolution density maps usually do not resolve protein regions that are only partially ordered, but these can sometimes be seen in lower-resolution density maps calculated from electron micrographs. We therefore used images of two-dimensional crystals and determined the structure of AQP4M23S180D at 10 Å resolution. The features of the 10-Å density map are consistent with those of the previously determined atomic model; in particular, there were no indications of any obstruction near the cytoplasmic pore entrance. In addition, water conductance measurements, both in vitro and in vivo, show the same water permeability for wild-type and mutant AQP4M23, suggesting that the S180D mutation neither reduces water conduction through a conformational change nor reduces water conduction by interacting with a protein that would obstruct the cytoplasmic channel entrance. Finally, the 10-Å map shows a cytoplasmic density in between four adjacent tetramers that most likely represents the association of four N termini. This finding supports the critical role of the N terminus of AQP4 in the stabilization of orthogonal arrays, as well as their interference through lipid modification of cysteine residues in the longer N-terminal isoform.