Mathematical analysis and numerical comparison of energy-conservative schemes for the Zakharov equations

Furihata and Matsuo proposed in 2010 an energy-conserving scheme for the Zakharov equations, as an application of the discrete variational derivative method (DVDM). This scheme is distinguished from conventional methods (in particular the one devised by Glassey in 1992) in that the invariants are consistent with respect to time, but it has not been sufficiently studied both theoretically and numerically. In this study, we theoretically prove the solvability under the loosest possible assumptions. We also prove the convergence of this DVDM scheme by improving the argument by Glassey. Furthermore, we perform intensive numerical experiments for comparing the above two schemes. It is found that the DVDM scheme is superior in terms of accuracy, but since it is fully-implicit, the linearly-implicit Glassey scheme is better for practical efficiency. In addition, we proposed a way to choose a solution for the first step that would allow Glassey's scheme to work more efficiently

Clinical Approaches for Understanding the Expression Levels of Pattern Recognition Receptors in Otitis Media with Effusion

Objectives. Bacterial infections in the normally sterile environment of the middle ear cavity usually trigger host immune response, whereby the innate immune system plays a dominant role as the host’s first line of defense. We evaluated the expression levels of Toll-like receptors (TLRs)-2,-4,-5,-9, and nucleotide-binding oligomerization domain-containing proteins (NODs)-1 and-2, all of which are related to bacterial infection in pediatric patients with otitis media with effusion (OME). Methods. The study sample consisted of 46 pediatric patients with OME, all of whom had ventilation tubes inserted. The expression levels of TLR-2,-4,-5,-9, NOD-1 and-2 mRNA in middle ear effusion were assessed by polymerase chain reaction (PCR). Difference of pattern recognition receptors (PRRs) expression level by presence of bacteria, ventilation tube insertion rate, and effusion fluid character was assessed. Results. All effusion fluid samples collected from patients with OME showed expression of TLR-2,-4,-5,-9, NOD-1, and-2 mRNA by PCR. However, we found no differences among expression levels of PRRs in relation to characteristics of exudates, presence of bacteria, or frequencies of ventilation tube insertion (P>0.05). Conclusion. Our findings suggest that exudates of OME patients show PRR expressions that are related to the innate immune response regardless of the characteristics of effusion fluid, presence of bacteria in exudates, or frequency o

Macaque models of human infectious disease.

Macaques have served as models for more than 70 human infectious diseases of diverse etiologies, including a multitude of agents-bacteria, viruses, fungi, parasites, prions. The remarkable diversity of human infectious diseases that have been modeled in the macaque includes global, childhood, and tropical diseases as well as newly emergent, sexually transmitted, oncogenic, degenerative neurologic, potential bioterrorism, and miscellaneous other diseases. Historically, macaques played a major role in establishing the etiology of yellow fever, polio, and prion diseases. With rare exceptions (Chagas disease, bartonellosis), all of the infectious diseases in this review are of Old World origin. Perhaps most surprising is the large number of tropical (16), newly emergent (7), and bioterrorism diseases (9) that have been modeled in macaques. Many of these human diseases (e.g., AIDS, hepatitis E, bartonellosis) are a consequence of zoonotic infection. However, infectious agents of certain diseases, including measles and tuberculosis, can sometimes go both ways, and thus several human pathogens are threats to nonhuman primates including macaques. Through experimental studies in macaques, researchers have gained insight into pathogenic mechanisms and novel treatment and vaccine approaches for many human infectious diseases, most notably acquired immunodeficiency syndrome (AIDS), which is caused by infection with human immunodeficiency virus (HIV). Other infectious agents for which macaques have been a uniquely valuable resource for biomedical research, and particularly vaccinology, include influenza virus, paramyxoviruses, flaviviruses, arenaviruses, hepatitis E virus, papillomavirus, smallpox virus, Mycobacteria, Bacillus anthracis, Helicobacter pylori, Yersinia pestis, and Plasmodium species. This review summarizes the extensive past and present research on macaque models of human infectious disease

Three Dimensional Analysis of the Wind Induced Flow by means of the Low Reynolds Number k-ε Turbulent Model

Numerical experiments were conducted by means of the k- ε turbulent model to understand the three dimensional turbulent structure of the wind induced flow in the closed water body. First, three types of the k- ε models were evaluated in terms of their adaptabilities to the wind induced flow. Next, the Low Reynolds number k- ε model, which had the best adaptability, was used to analyze the influence of the aquatic plants luxuriating on the water surface. The analysis was performed under the different luxuriant patterns in which the part of water surface in the water tank is covered with the aquatic plants. The analytical results indicated that the scale of the flow became very small below the aquatic plants. In addition, the flow field was divided into two portions when the aquatic plants were located at the center of the water tank. In this luxuriant pattern, the scale of the flow circulation, which was assessed through the distribution of the eddy viscosity coefficient, significantly decreased compared with other patterns although the luxuriant rates of the aquatic plants were equal

低レイノルズ数型k-ε乱流モデルを用いた吹送流の三次元数値解析

Numerical experiments were conducted by means of the k- ε turbulent model to understand the three dimensional turbulent structure of the wind induced flow in the closed water body. First, three types of the k- ε models were evaluated in terms of their adaptabilities to the wind induced flow. Next, the Low Reynolds number k- ε model, which had the best adaptability, was used to analyze the influence of the aquatic plants luxuriating on the water surface. The analysis was performed under the different luxuriant patterns in which the part of water surface in the water tank is covered with the aquatic plants. The analytical results indicated that the scale of the flow became very small below the aquatic plants. In addition, the flow field was divided into two portions when the aquatic plants were located at the center of the water tank. In this luxuriant pattern, the scale of the flow circulation, which was assessed through the distribution of the eddy viscosity coefficient, significantly decreased compared with other patterns although the luxuriant rates of the aquatic plants were equal

Evaluation of the Fertilizer Characteristics of Nitrogen in Liquid Compost by Rice Cultivation in Pots

We aimed to obtain the fundamental data of the fertilizer characteristics of nitrogen in liquid compost (LC), which is produced from organic wastes such as human waste and sewage sludge. The rice cultivar Hinihokari was cultivated in pots, and 5 combinations of basal fertilization and topdressing using chemical fertilizer and LC were applied in the experimental plots. Growth indicators such as plant length, the number of tillers, and the SPAD value were measured during the rice-growth season, and the amounts of nitrogen absorbed by the rice plants were estimated using these values. In addition, to understand the fertilizer characteristics of nitrogen in LC, we measured the inorganic-nitrogen concentration in the soil water. In the experimental plots in which either chemical fertilizer or LC was applied as basal fertilizer, nitrogen absorption during the initial growth stage (i.e., from transplantation to 24 days after transplantation) did not differ significantly; however, the nitrogen absorption was slightly lower in the experimental plots, in which LC was applied as the basal fertilizer. Further, the ammonium-nitrogen concentration in soil water indicated that the organic nitrogen in LC was completely mineralized at approximately 40 days after the transplantation. This phenomenon was considered to be responsible for the lowered nitrogen absorption during the initial growth stage in the plants that underwent basal fertilization with LC. In addition, in the experimental plots in which LC topdressing was applied, nitrogen absorption in the late period of rice growth (i.e., from 40 days to 55 days after transplantation) was low, and we hypothesized that the ammonium-nitrogen in LC was lost through volatilization, since the topdressing was applied to the soil surface. Further, rainfall greater than 40 mm $day^-1$ continued for 3 days after the topdressing, and leaching of the fertilizer components was suspected.本研究では，液状堆肥の窒素成分の肥料特性に関する基礎データを得ることを目的に，ポット栽培試験を実施した．化成肥料と液状堆肥を組み合わせて基肥と追肥を行った５試験区について，水稲の窒素吸収量を推定した．さらに，生育期間中の土壌水の無機態窒素濃度の計測結果と水稲の窒素吸収量を照査し，液状堆肥の肥料特性について考察した．得られた結果は以下の通りである.（1）生育初期において化成肥料区と液状堆肥区の間の推定窒素吸収量に若干の差が見られたが，生育中期（移植35日後）において，窒素吸収量は同程度になった.（2）LC-NF〈Non-Plant〉区の土壌水のアンモニア態窒素濃度の変化および上記（1）の結果を踏まえて，液状堆肥の20％程度含まれる有機態窒素の無機化が，移植後40日頃まで続くと推察された.（3）液状堆肥の追肥区は，化成肥料の追肥区に比べ，生育後期（移植40日～55日後）の窒素吸収量が低く推移した．これは，追肥の表層施用による液状堆肥に含まれる窒素成分の揮散や，追肥後の降雨による流亡が原因として考えられる