Effect of the growth rate of Pseudomonas aeruginosa biofilms on the susceptibility to antimicrobial agents: beta-lactams and fluoroquinolones

The combined effects of meal cost and food flavor on meal size were studied with a method that avoided the covariation of nutrient composition and caloric density with palatability. As rats (Rattus norvegicus) drank flavored fluids (unpalatable 0.05% sucrose octaacetate [SOA], neutral 0.05% saccharin, and palatable 2% Polycose + 0.2% saccharin [P + S]), liquid diet was infused intragastrically. Relative to saccharin, rats with free access ate 10% more calories in larger meals while consuming P + S and initially ate fewer calories in smaller but more frequent meals while drinking SOA. Other rats lever-pressed to begin meals, which halved meal number and doubled meal size relative to the free-access group. Although foraging rats also ate larger P + S meals and smaller SOA meals, the changes did not affect total intake. Without the usual differential postingestive effects of foods that differ in palatability, making food more costly blunts rats' response to its flavor.     

Area selective epitaxy of indium phosphide on silicon (100) substrates without buffer layers by liquid phase epitaxy

Area selective epitaxy (ASE) of InP was performed by liquid phase epitaxy on Si (100) substrates without the use of buffer layers. At the start of epitaxy, the growth temperature was rapidly lowered to obtain high supersaturation. Epitaxial growth was then carried out at constant temperature. While small InP nuclei were observed in the broader open areas, ASE layers and layers showing slight epitaxial lateral overgrowth were formed in the narrow openings. Etch pit density of the InP ASE layers on Si is dependent on the length of open seed region and X-ray diffraction results indicate that the lattice strain in the InP nuclei on the Si substrate was fully relaxed.     

Are bibliometric measures consistent with scientists’ perceptions? The case of interdisciplinarity in research

Scientometrics - Interdisciplinary research (IDR) has become an important component in the conduction of leading-edge science and innovation. From the different approaches available to measuring...     

A level set based topology optimization method using the discretized signed distance function as the design variables

This paper deals with a new topology optimization method based on the level set method. In the proposed method, the discretized signed distance function, a kind of level set function, is used as the design variables, and these are then updated using their sensitivities. The signed distance characteristic of the design variables are maintained by performing a re-initialization at every update during the iterated optimization procedure. In this paper, a minimum mean compliance problem and a compliant mechanism design problem are formulated based on the level set method. In the formulations of these design problems, a perimeter constraint is imposed to overcome the ill-posedness of the structural optimization problem. The sensitivity analysis for the above structural optimization problems is conducted based on the adjoint variable method. The augmented Lagrangian method is incorporated to deal with multiple constraints. Finally, several numerical examples that include multiple constraints are provided to confirm the validity of the method, and it is shown that appropriate optimal structures are obtained.     

Efficient parallel processing of competitive learning algorithms

Vector quantization (VQ) is an attractive technique for lossy data compression, which has been a key technology for data storage and/or transfer. So far, various competitive learning (CL) algorithms have been proposed to design optimal codebooks presenting quantization with minimized errors. Although algorithmic improvements of these CL algorithms have achieved faster codebook design than conventional ones, limitations of speedup still exist when large data sets are processed on a single processor. Considering a variety of CL algorithms, parallel processing on flexible computing environment, like general-purpose parallel computers is in demand for a large-scale codebook design. This paper presents a formulation for efficiently parallelizing CL algorithms, suitable for distributed-memory parallel computers with a message-passing mechanism. Based on this formulation, we parallelize three CL algorithms: the Kohonen learning algorithm, the MMPDCL algorithm and the LOJ algorithm. Experimental results indicate a high scalability of the parallel algorithms on three different types of commercially available parallel computers: IBM SP2, NEC AzusA and PC cluster.     

Specific Gut Microbial Environment in Lard Diet-Induced Prostate Cancer Development and Progression

Lard diet (LD) is a risk factor for prostate cancer (PCa) development and progression. Two immunocompetent mouse models fed with isocaloric specific fat diets (LD) enriched in saturated and monounsaturated fatty acid (SMFA), showed significanftly enhanced PCa progression with weight gain compared with a fish oil diet (FOD). High gut microbial divergency resulted from difference in diets, and the abundance of several bacterial species, such as in the orders Clostridiales and Lactobacillales, was markedly altered in the feces of LD- or FOD-fed mice. The proportion of the order Lactobacillales in the gut was negatively involved in SMFA-induced body weight gain and PCa progression. We found the modulation of lipid metabolism and cholesterol biosynthesis pathways with three and seven commonly up- and downregulated genes in PCa tissues, and some of them correlated with the abundance of the order Lactobacillales in mouse gut. The expression of sphingosine 1-phosphate receptor 2, which is associated with the order Lactobacillales and cancer progression in mouse models, was inversely associated with aggressive phenotype and weight gain in patients with PCa using the NCBI Gene Expression Omnibus database. Therefore, SMFA may promote PCa progression with the abundance of specific gut microbial species and overexpression of lipogenic genes in PCa. Therapeutics with alteration of gut microbiota and candidate genes involved in diet-induced PCa progression may be attractive in PCa.     

Improvement of thickness and uniformity of isotopically enriched C targets on backings by the HIVIPP method

We have made enriched ¹²C targets to accurately measure the cross-section of the ¹²C(α,γ)¹⁶O reaction, which is very important in nuclear astrophysics. Isotopically enriched ¹²C targets for studying this small cross-section, especially for use with an intense pulsed α beam was desired to meet the following requirements: (1) use of impurity-free enriched ¹²C, (2) stability for a long time measurement and (3) uniform thickness in the range 200–300 μg/cm². To meet these experimental requirements, isotopically enriched amorphous ¹²C powder was converted into graphite powder in an electric furnace at a temperature of 3000 K and subsequently the graphite powder was deposited on a thick Au backing via the HIVIPP method. Targets thus prepared could be made thicker than 200 μg/cm². They had a good uniformity and a very high stability against irradiation with high intensity ion beams.     

First results of target preparation by the HIVIPP method in pressures higher than one bar

We recently developed a new variation for the deposition method named HIVIPP (HIgh energy VIbrational Powder Plating), which is based on the high-energy vibrational motion of powder in the high electric field between parallel electrodes at room temperature and in vacuum. The HIVIPP method is very simple and does not require any complicated mechanisms to prepare both supported (backed) and self-supporting targets. The motivation for the present work was a desire to explore whether it could be done successfully with pressures higher than one bar, with reactive gases or inert gases, and without a vacuum-pumping system. The first successful results are reported for depositions of metallic chromium and non-metallic silicon powders in nitrogen, oxygen, and air at >1 bar.     

High-speed μc-Si films deposition and large-grain poly-Si films deposition by surface wave discharge

Microcrystalline silicon (μc-Si) and polycrystalline silicon (poly-Si) films are deposited by surface wave (SW) discharge at 2.45 GHz in H₂/SiH₄ gas. This high density SW plasma at relatively low pressures (4-60 Pa) enables strong dissociation of feedstock gas. The films deposited on substrate are investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The SW discharge in 10% SiH₄ at total pressure of ∼ 30 Pa gives μc-Si films on a substrate at 250 °C, at a fairly high deposition rate of 4-20 nm/s, with a crystalline volume fraction of 0.5-0.8 and a grain size of 10-40 nm. Furthermore, poly-Si film with crystalline volume fraction of > 99% is deposited at higher substrate temperature (400 °C) in 2% SiH₄ discharge at lower pressure (4 Pa). X-ray diffraction and SEM results revealed that the grain size of poly-Si films is as large as 600 nm, which is almost 6 times larger than previously reported values.     

Study on underground thermal characteristics by using digital national land information, and its application for energy utilization

This paper describes a method for evaluating characteristics of underground thermal properties and groundwater, whose evaluation is essential for designing systems of underground thermal energy utilization. First, the systems using underground thermal energy are classified into two categories: borehole system with indirect heat exchange, and aquifer system with direct use of underground water. These systems are also divided into thermal storage systems and heat source/sink systems. Second, the characteristics of the underground in Japan are analyzed by using a geographical information system (GIS) and hydrogeological information. Regulations on environmental protection, such as those relating to national parks for instance, and the distribution of thermal energy demand eliminate 77% of Japan from consideration for underground thermal energy utilization. Areas limited to borehole thermal energy utilization account for 17% of areas where underground thermal energy can be used, with the remaining 74% suitable for both boreholes and aquifers. Finally, we estimate the thickness of aquifer and groundwater velocity in Sapporo. We find that most parts of Sapporo are suitable for aquifer thermal energy storage (ATES).