Toward the chemical ecology of medicinal plant use in chimpanzees: The case ofVernonia amygdalina,a plant used by wild chimpanzees possibly for parasite-related diseases

The bitter and related constituents have been isolated fromVernonia amygdalina (Compositae), a plant ingested by wild chimpanzees possibly suffering from parasite-related diseases in the Mahale Mountains National Park, Tanzania. Isolated from the plant were four known sesquiterpene lactones, seven new steroid glucosides, and two aglycones of the glucosides. The sesquiterpene lactones showed significant in vitro antischistosomal, plasmodicidal, and leishmanicidal activities. Antischistosomal activity was also found for the major steroid glucoside, vernonioside B₁. A trend in the glucosides to show significant antischistosomal, plasmodicidal, and amebicidal activities when the sugar moiety was removed, was observed. Vernodalin, judged as the most significant constituent for antiparasitic activities in vitro, was tested for in vivo antischistosomal effect. It was, however, highly toxic to the cercaria-infected mouse. Chimpanzees have been only rarely observed to ingest anything but the pith of the young stem. The occurrence of vernonioside B₁ and its aglycone vernoniol B₁, the major constituents among the steroid-related constituents, were detected at significant levels in the pith. However, vernodalin was abundant only in the leaves and bark. Thus, chimpanzees at Mahale were hypothesized to control parasite-related diseases by ingesting the young pith of this tree containing steroid-related constituents.     

Kernel-based transition probability toward similarity measure for semi-supervised learning

For improving the classification performance on the cheap, it is necessary to exploit both labeled and unlabeled samples by applying semi-supervised learning methods, most of which are built upon the pair-wise similarities between the samples. While the similarities have so far been formulated in a heuristic manner such as by k-NN, we propose methods to construct similarities from the probabilistic viewpoint. The kernel-based formulation of a transition probability is first proposed via comparing kernel least squares to variational least squares in the probabilistic framework. The formulation results in a simple quadratic programming which flexibly introduces the constraint to improve practical robustness and is efficiently computed by SMO. The kernel-based transition probability is by nature favorably sparse even without applying k-NN and induces the similarity measure of the same characteristics. Besides, to cope with multiple types of kernel functions, the multiple transition probabilities obtained correspondingly from the kernels can be probabilistically integrated with prior probabilities represented by linear weights. We propose a computationally efficient method to optimize the weights in a discriminative manner. The optimized weights contribute to a composite similarity measure straightforwardly as well as to integrate the multiple kernels themselves as multiple kernel learning does, which consequently derives various types of multiple kernel based semi-supervised classification methods. In the experiments on semi-supervised classification tasks, the proposed methods demonstrate favorable performances, compared to the other methods, in terms of classification performances and computation time.     

Oxidative Dehydrogenation of Propane on Calcium Hydroxyapatites Partially Substituted with Vanadate

Solid solutions of phosphate and vanadate calcium hydroxyapatites were synthesized and the catalytic activities for the oxidative dehydrogenation of propane to propylene on those catalysts were examined. Although the conversion of propane and the selectivity to propylene were 7.6 and 3.5% on calcium hydroxyapatite (CaHAp), the incorporation of vanadate to CaHAp by V/P=0.05 (atomic ratio) resulted in the enhancement of the conversion and the selectivity to 17.2 and 52.4%, respectively, corresponding to those on Mg₂V₂O₇ under the same reaction conditions (14.0 and 50.9%, respectively).     

Densification Energy during Nanoindentation of Silica Glass

Load/unload displacement curves at room temperature (humidity 49%) for silica glass have been measured in the penetration range of 0.5–1.2 μm using a Vickers nanoindentation technique (load/unload speed 50 mN/s). Deformation energies have been estimated for the first time. The universal (dynamic) hardness, H _u, and elastic recovery, E _R, at the penetration depth, h _t, of 1.0 μm are H _u= 4.1 GPa and E _R= 0.7. The following energies for total deformation, U _t, elastic deformation, U _e, and plastic deformation (i.e., densification during loading), U _p, are obtained: U _t=190, U _e=135 and U _p= 55 kJ/mol at h _t= 0.5 μm and U _t= 139, U _e= 96 and U _p= 43 kJ/mol at h _t=1.0 μm. All these deformation energies increase with decreasing penetration depth. It is found that plastic deformation energies of 38–55 kJ/mol for 0.5 < h _t < 1.2 μm are very close to the activation energy (46–54 kJ/mol) for the recovery of densification in silica glass, but are very small compared with the single bond strength (443 kJ/mol for Si—O bond) of SiO₂.     

Structural characteristics,rheological properties,extrusion, and melt spinning of 60/40 poly(hydroxybenzoic acid-coethylene terephthalate) (PHB/PET)

The rheological properties, extrusion, and melt spinning characteristics, and concomitant morphological features of 60/40 PHB/PET aromatic copolyester have been investigated. The material flows at temperatures above 190°C, but all crystallites may not melt completely until about 250°C. The material exhibits a yield stress value in shear flow. In fact, yield stress values were measured over a range of temperature from 190 to 260°C and estimated at higher temperatures. Extrudate swell measurements were also made in the same range. Significant extrudate swell does not occur until the fluid is at a temperature where the yield stress is approximately 1/50th of its maximum value. Extrudates are fibrillar in character and exhibit significant levels of crystalline orientation. The level of crystalline orientation in melt spun fibers does not vary significantly with drawdown ratio, since it is apparently developed to near its limiting extent during its flow through the die. All of these responses are similar to those observed in melt flow/processing studies of thermotropic liquid crystalline hydroxypropylcellulose.     

Study on organosilicon positive resist. II. Organosilicon positive photoresist (OSPR–1334) and its application to bilayer resist system

A new alkali-developable organosilicon positive photoresist (OSPR–1334) and a bilayer resist process with OSPR–1334 has been developed. OSPR–1334 is composed of poly(p-hydroxybenzylsilsesquioxane) and naphthoquinone diazide. The sensitivity and the resolution are almost the same as those of conventional novolac-based resists when aqueous tetrakis (2-hydroxyethyl) ammonium hydroxide is used as a developer. Also, OSPR–1334 has excellent resistance to O₂RIE. The etching rate is 3.6 nm/min, while that of polyimide resins or hard-baked novolac-based resists is 100 nm/min. OSPR–1334 is suitable for use as the top layer of the bilayer resist system. OSPR–1334, after O₂RIE, can be eliminated by dissolving an unchanged layer followed by spinning out or filtrating a changed surface layer. Submicron patterns with a high aspect ratio can easily be obtained with this bilayer resist process.     

Preparation of high magnetic flux density CoNiFeB film by electroless deposition for application to magnetic recording devices

A CoNiFeB soft magnetic thin film with high saturation magnetic flux density (B_s) for use as a magnetic recording head core material or as a soft magnetic underlayer of a double perpendicular magnetic recording medium was prepared by electroless deposition. When the CoNiFeB alloy thin film was deposited on a evaporated Cu (100 nm thick)/glass substrate, the saturated magnetic flux density was found to increase up to 2.0 T by increasing the concentration of FeSO₄. The coercivity (H_c) was found to decrease to 6 Oe while the saturated magnetic flux density was maintained higher than 1.8 T by optimizing the concentrations of tartaric acid and citric acid in the electroless plating solution. An X-ray diffraction (XRD) study showed that the intensity of the assigned peak in the bcc (1 1 0) of CoNiFeB film decreased as the concentration of tartaric acid was decreased. Moreover, the coercivity of the CoNiFeB film formed on a NiFe substrate exhibits lower coercivity than that formed on a Cu substrate.     

Genome‐Wide Assessment of the Binding Effects of Artificial Transcriptional Activators by High‐Throughput Sequencing

One of the major goals in DNA‐based personalized medicine is the development of sequence‐specific small molecules to target the genome. SAHA‐PIPs belong to such class of small molecule. In the context of the complex eukaryotic genome, the differential biological effects of SAHA‐PIPs are unclear. This question can be addressed by identifying the binding regions across the genome; however, it is a challenge to enrich small‐molecule‐bound DNA without chemical crosslinking. Here, we developed a method that employs high‐throughput sequencing to map the binding area of small molecules throughout the chromatinized human genome. Analysis of the sequenced data confirmed the presence of specific binding sites for SAHA‐PIPs from the enriched sequence reads. Mapping the binding sites and enriched regions on the human genome clarifies the reason for the distinct biological effects of SAHA‐PIP. This approach will be useful for identifying the function of other small molecules on a large scale.     

Prediction of Type IV creep failure of a seam-welded mod. 9Cr-1Mo elbow based on microscopic damage simulation

Utilising the random-fracture-resistance model of grain boundaries, micro-macro combined creep damage simulation was applied to the prediction of the distribution of small defects in the FGHAZ (fine-grained heat-affected zone) of longitudinal welds in an actual-size elbow of modified 9Cr-1Mo (9Cr-1MoVNb) steel subject to internal pressure at 923 K. Based on the simulation results, a prediction scheme for the final rupture life of welds was considered using the damage mechanics concept together with effective stress. The applicability of nonlinear fracture mechanics was also discussed, assuming the initial crack length determined from the microscopic simulation results. The results thus obtained are summarized as follows: As the simulation results showed, the peaks of small defect density in the subsurface could be predicted, corresponding well with the observed results. Final failure life prediction based on the damage mechanics concept was found to be applicable, by considering both the final failure surface connecting the weakest grain boundaries and the effective stress against this surface. The fracture mechanics approach was also found applicable when assuming the initial crack length from the high peaks of the simulated small defects in the last stage of creep life.