A Numerical Method for Distinction between Blow-up and Global Solutions of the Nonlinear Heat Equation

The famous one-dimensional nonlinear heat equation is considered. To this equation a numerical method for distinction between blow-up and global solutions is proposed. Difficulty is in the treatment of the global solution which is defined in the infinite interval. The bounding transform is used to overcome this difficulty. Numerical experiments show the validity of our method

J- and Ks-band Galaxy Counts and Color Distributions in the AKARI North Ecliptic Pole Field

We present the J- and Ks-band galaxy counts and galaxy colors covering 750 square arcminutes in the deep AKARI North Ecliptic Pole (NEP) field, using the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer (FLAMINGOS) on the Kitt Peak National Observatory (KPNO) 2.1m telescope. The limiting magnitudes with a signal-to-noise ratio of three in the deepest regions are 21.85 and 20.15 in the J- and Ks-bands respectively in the Vega magnitude system. The J- and Ks-band galaxy counts in the AKARI NEP field are broadly in good agreement with those of other results in the literature, however we find some indication of a change in the galaxy number count slope at J~19.5 and over the magnitude range 18.0 < Ks < 19.5. We interpret this feature as a change in the dominant population at these magnitudes because we also find an associated change in the B - Ks color distribution at these magnitudes where the number of blue samples in the magnitude range 18.5 < Ks < 19.5 is significantly larger than that of Ks < 17.5

Gene up-regulation in response to predator kairomones in the water flea, Daphnia pulex

<p>Abstract</p> <p>Background</p> <p>Numerous cases of predator-induced polyphenisms, in which alternate phenotypes are produced in response to extrinsic stimuli, have been reported in aquatic taxa to date. The genus <it>Daphnia </it>(Branchiopoda, Cladocera) provides a model experimental system for the study of the developmental mechanisms and evolutionary processes associated with predator-induced polyphenisms. In <it>D. pulex</it>, juveniles form neckteeth in response to predatory kairomones released by <it>Chaoborus </it>larvae (Insecta, Diptera).</p> <p>Results</p> <p>Previous studies suggest that the timing of the sensitivity to kairomones in <it>D. pulex </it>can generally be divided into the embryonic and postembryonic developmental periods. We therefore examined which of the genes in the embryonic and first-instar juvenile stages exhibit different expression levels in the presence or absence of predator kairomones. Employing a candidate gene approach and identifying differentially-expressed genes revealed that the morphogenetic factors, <it>Hox3</it>, <it>extradenticle </it>and <it>escargot</it>, were up-regulated by kairomones in the postembryonic stage and may potentially be responsible for defense morph formation. In addition, the juvenile hormone pathway genes, <it>JHAMT </it>and <it>Met</it>, and the insulin signaling pathway genes, <it>InR </it>and <it>IRS-1</it>, were up-regulated in the first-instar stage. It is well known that these hormonal pathways are involved in physiological regulation following morphogenesis in many insect species. During the embryonic stage when morphotypes were determined, one of the novel genes identified by differential display was up-regulated, suggesting that this gene may be related to morphotype determination. Biological functions of the up-regulated genes are discussed in the context of defense morph formation.</p> <p>Conclusions</p> <p>It is suggested that, following the reception of kairomone signals, the identified genes are involved in a series of defensive phenotypic alterations and the production of a defensive phenotype.</p

HIGH-DOSE-RATE AFTERLOADING INTRACAVITARY IRRADIATION AND EXPANDABLE METALLIC BILIARY ENDOPROSTHESIS FOR MALIGNANT BILIARY OBSTRUCTION

A double lumen catheter was developed as an applicator for the remote afterloading system (RALS) of ⁶⁰Co for the intracavitary irradiation of an obstructed common bile duct due to gallbladder cancer in 1 case and by cholangiocarcinoma in 7 cases. This was followed by the biliary endoprosthesis with expandable metallic stents to maintain patency. The mean survival period after treatment was not long (14 weeks). However, removal of the external drainage tube was possible in 7 of the 8 cases, and none of the 8 cases showed dislodgement or deformity of the stent, or obstruction of the bile duct in the stent-inserted area. This combination effectively provided palliation, and has considerable potential for malignant biliary obstruction

Existence and Uniqueness of Quasiperiodic Solutions to Van der Pol type Equations

This paper is concerned with the existence and uniqueness of quasiperiodic solutions to Van der Pol type equations driven by two or more distinct frequency input signals from the viewpoint of numerical analysis. A numerical result given in the previous paper [13] is corrected

東京湾におけるコノシロ仔稚魚の出現様式と発育段階

Occurrence patterns of konoshiro gizzard shad Konosirus punctatus larvae and juveniles were examined in Tokyo Bay by monthly samplings using the following two types of gear: a small seine net towed at three tidal flats in the inner bay from June 2006 to August 2008 and at three surf zones in the outer bay from April 1998 to March 1999 except July 1998; and a ring net towed at five sites in offshore waters of the outer bay from April 1996 to March 1997 except August 1996. Their ontogenetic intervals were also determined by the development of swimming- and feeding-related characters based on 129 cleared and stained specimens of 3.6-25.1 mm in body length, BL. In the outer Tokyo Bay, specimens collected from offshore waters were 1,114 individuals ranging from 3.0 to 7.2 mm BL, while those from surf zones being 4,991 ranging from 7.8 to 34.1 mm BL. Specimens collected from the tidal flats of inner Tokyo Bay was 1,800 individuals ranging from 5.2 to 18.3 mm BL. Four developmental phases were detected on both the swimming and feeding functions. Spawning grounds of K. punctatus are suggested to be formed in offshore waters, lower reaches of rivers and a brackish lagoon of the inner Tokyo Bay as well as offshore waters of outer Tokyo Bay. The surf zones and tidal flats of Tokyo Bay were clarified to be a nursery ground for K. punctatus larvae/juveniles. However, the larval body size when the number of individuals starts decreasing was different between the tidal flats, > ca. 10 mm BL and the surf zone, > ca. 18 mm BL. Based on the developmental phases, K. punctatus larvae/juveniles would acquire the functional, juvenile swimming and feeding abilities at about 18 mm BL, and thus the decrease in the surf zones are considered to be an active behaviour to shift their habitats for more adequate growth. However in the tidal flats of inner bay, the decrease in number is not accounted by habitat shifts but supposed to be caused by such other factors as the water quality, extent of tidal flats and/or any other unknown causes.東京湾外湾の沖合5地点（稚魚ネット：1996年4月～1997年3月）と砕波帯3地点（地曳網：1998年4月～1999年3月）および内湾の干潟域3地点（地曳網：2006年6月～2008年8月）で採集したコノシロの仔稚魚について、その出現状況を明らかにした。さらに129個体（体長3.6～25.1mm）を透明骨格標本にし、遊泳・摂餌機能に関する形質の発達を観察した。外湾の沖合では1,114個体（体長3.0～7.2mm）が、砕波帯では4,991個体（7.8～34.1mm）が、さらに内湾の干潟域では1,800個体（5.2～18.3mm）が出現した。関連形質の発達に基づいて、遊泳・摂餌機能別の発育段階をそれぞれ4段階設定した。産卵場は外湾の沖合だけではなく、内湾の沖合や河川下流域、あるいは汽水の潟湖などに形成されることが示唆された。外湾の砕波帯と内湾の干潟域はコノシロ仔稚魚の成育場であるが、採集された個体数は干潟域では体長10mm以上、砕波帯では18mm以上になると減少しはじめた。体長18mmで稚魚としての遊泳・摂餌能力が獲得されるため、砕波帯での個体数の減少は、より良い成長をするために積極的な生息場の移動をおこなった結果だと考えられた。しかし内湾の干潟域における個体数の減少は、生息場の移動では説明できないため、水質や干潟域の規模、あるいは何らかの他の要因に起因すると推定された。David E. ANGMALISANG(Corresponding author), Hitoshi IMAI and Hiroshi KOHNO: Laboratory of Ichthyology, Tokyo University of Marine Science and Technology (TUMSAT)デイビッド E. アンマリサン・今井仁・河野 博: 東京海洋大学魚類学研究室Hitoshi IMAI: Present address: Japan Wildlife Research Center今井仁: 一般財団法人 自然環境研究センターHiroshi KOHNO: Department of Ocean Sciences, Tokyo University of Marine Science and Technology (TUMSAT)河野博: 東京海洋大学学術研究院海洋環境科学部

Radiological evaluation of joint space width in medial knee osteoarthritis

Background. Although joint space width on weight-bearing radiographs of the knee is critical for early diagnosis and grading knee osteoarthritis, the optimal method with which to accurately measure this value remains controversial. The purpose of this study was to investigate and quantify the effects of the radiographic technique on joint space width in medial knee osteoarthritis.Materials and Methods. We compared maximum plateau gaps and minimum joint space widths on bilateral weight-bearing plain radiographs acquired using three different methods in 31 patients with medial knee osteoarthritis (56 knee joints): standing with the knee extended (standard imaging); SynaFlexer method; and Rosenberg method. Measured values were compared statistically, with values of P < 0.05 considered significant.Results. Maximum plateau gap in the medial compartment was significantly lower with the SynaFlexer method (3.2 ± 1.5 mm) and Rosenberg method (2.2 ± 1.2 mm) than with standard imaging (4.7 ± 2.2 mm; P < 0.05 each). Minimum width of the medial joint space was also significantly lower with the SynaFlexer method (3.1 ± 1.4 mm) and Rosenberg method (2.3 ± 1.4 mm) than with standard imaging (4.1 ± 1.4 mm; P < 0.05 each).Conclusion. The Rosenberg method appears beneficial for diagnosing early knee osteoarthritis, while the SynaFlexer method seems more appropriate for assessing disease severity or progression in patients with painful intermediate to severe knee osteoarthritis