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Dystrophinopathy is caused by alterations in DMD. Approximately 1% of patients remain genetically undiagnosed because intronic variations are not detected by standard methods. Here, we combined laboratory and in silico analyses to identify disease-causing genomic variants in genetically undiagnosed patients and determine the regulatory mechanisms underlying abnormal DMD transcript generation. DMD transcripts from 20 genetically undiagnosed dystrophinopathy patients in whom no exon variants were identified, despite dystrophin deficiency on muscle biopsy, were analyzed by transcriptome sequencing. Genome sequencing captured intronic variants and their effects were interpreted using in silico tools. Targeted long-read sequencing was applied in cases with suspected structural genomic abnormalities. Abnormal DMD transcripts were detected in all cases analyzed. Exonization of intronic sequences was observed in 15 cases and exon skipping in one case; 13 single nucleotide variants and three structural rearrangements were identified as causal genomic variations. DMD transcripts were aberrantly spliced and polyadenylated in two cases in which chromosome rearrangements were detected. In one case, DMD transcripts were terminated due to nucleotide repeat expansion. Our combined analysis approach successfully identified pathogenic events. Detection of diseasing-causing mechanisms in DMD transcripts could inform the therapeutic options for patients with dystrophinopathy.

Dystrophinopathy is caused by alterations in DMD. Approximately 1% of patients remain genetically undiagnosed, because intronic variations are not detected by standard methods. Here, we combined laboratory and in silico analyses to identify disease-causing genomic variants in genetically undiagnosed patients and determine the regulatory mechanisms underlying abnormal DMD transcript generation. DMD transcripts from 20 genetically undiagnosed dystrophinopathy patients in whom no exon variants were identified, despite dystrophin deficiency on muscle biopsy, were analyzed by transcriptome sequencing. Genome sequencing captured intronic variants and their effects were interpreted using in silico tools. Targeted long-read sequencing was applied in cases with suspected structural genomic abnormalities. Abnormal DMD transcripts were detected in 19 of 20 cases; Exonization of intronic sequences in 15 cases, exon skipping in one case, aberrantly spliced and polyadenylated transcripts in two cases and transcription termination in one case. Intronic single nucleotide variants, chromosomal rearrangements and nucleotide repeat expansion were identified in DMD gene as pathogenic causes of transcript alteration. Our combined analysis approach successfully identified pathogenic events. Detection of diseasing-causing mechanisms in DMD transcripts could inform the therapeutic options for patients with dystrophinopathy.

Carnitine-acylcarnitine translocase (CACT) deficiency is a fatty acid ß-oxidation disorder of the carnitine shuttle in mitochondria, with a high mortality rate in childhood. We evaluated three patients, including two siblings, with neonatal-onset CACT deficiency and revealed identical homozygous missense mutations of p.Arg275Gln within the SLC25A20 gene. One patient died from hypoglycemia and arrhythmia at 26 months; his pathological autopsy revealed increased and enlarged mitochondria in the heart but not in the liver., 論文

Objectives The aim of this study was to develop and validate a simple and reliable gas chromatography‐mass spectrometry (GC‐MS) method to simultaneously determine urinary 1‐naphthol (1‐NAP) and 2‐naphthol (2‐NAP) for biological monitoring of occupational exposure to naphthalene. Methods NAPs were derivatized in situ with acetic anhydride after enzymatic hydrolysis, extracted with n‐hexane, and analyzed using GC‐MS. Validation of the proposed method was conducted in accordance with US Food and Drug Administration guidance. A final validation was performed by analyzing a ClinChek®‐Control for phenolic compounds. Results The linearity of calibration curves was indicated by a high correlation coefficient (>0.999) in the concentration range 1‐100 μg/L for each NAP. The limits of detection and quantification for each NAP were 0.30 and 1.00 μg/L, respectively. The recovery was 90.8%‐98.1%. The intraday and interday accuracies, expressed as the deviation from the nominal value, were 92.2%‐99.9% and 93.4%‐99.9%, respectively. The intraday and interday precision, expressed as the relative standard deviation, was 0.3%‐3.9% and 0.4%‐4.1%, respectively. The ClinChek® values obtained using our method were sufficiently accurate. Conclusions The proposed method is simple, reliable, and appropriate for routine analyses, and is useful for biological monitoring of naphthalene exposure in occupational health practice.

The neurological symptoms of pediatric mild encephalopathy/encephalitis with a reversible splenial lesion (MERS) are mild and have a good prognosis. However, some aspects of neonatal MERS are unclear due to a lack of clinical knowledge. We present a neonatal case of MERS with features of poor activity and prolonged poor oxygenation after birth without asphyxia. He was diagnosed with MERS by brain magnetic resonance imaging (MRI) on day10, because the diffusion restriction of the splenium of the corpus callosum (SCC) seen on diffusion-weighted MRI on day 5 was attenuating. He was discharged due to good progress on day 26, but growth issues and developmental delay were observed in the follow up from 1-10 months. In rare neonatal cases, many aspects of the clinical course and prognosis are thus unclear. MERS should be considered in newborns who show unexplained non-neural or other encephalopathic symptoms.

A Japanese boy aged 7 years with Bainbridge-Ropers syndrome (BRPS) had a prominent domed forehead without metric ridge, mild prominence of the Sylvian fissure with bitemporal hollowing, and a heterozygous de novo novel variant "p.P1010Lfs*14" in ASXL3 gene in addition to typical findings of BRPS., 論文

Isovaleric acidemia (IVA) is an organic acid disease caused by a deficiency of isovaleryl-CoA dehydrogenase. Deficiency of this enzyme leads to accumulation of organic acids, such as isovalerylcarnitine and isovalerylglycine. The proposed IVA treatments include leucine restriction and l-carnitine and/or glycine supplementation, which convert isovaleric acid into non-toxic isovalerylcarnitine and isovalerylglycine, respectively. We examined the therapeutic response using the leucine load test and performed a 10-year follow-up in the patient. Methods:We evaluated the patient with IVA beginning at 5 years of age, when he presented with a mild to intermediate metabolic phenotype. Ammonia, free carnitine, isovalerylcarnitine, and isovalerylglycine were analyzed in the urine and blood after a meal consisting of 1600 mg leucine with glycine alone (250 mg/kg/day), l-carnitine alone (100 mg/kg/day), or both glycine and l-carnitine for four days each. Results:(Leucine load test) Three hours after the meal, serum ammonia levels increased most dramatically with glycine treatment alone, then with both in combination, and least with l-carnitine alone. Urinary isovalerylglycine levels increased 2-fold more with glycine supplementation than those following supplementation with both agents or with l-carnitine alone. Treatment with both agents resulted in a gradual increase in urinary acylcarnitine levels during the 6-h period following the leucine load, reaching concentrations comparable to those observed with l-carnitine alone. (Clinical course) After initiation of both glycine (200 mg/kg/day) and l-carnitine (100 mg/kg/day) supplementation at 5 years of age, doses were gradually reduced to 111.7 mg/kg/day and 55.8 mg/kg/day, respectively, at 15 years of age. His mind and body had developed without any sequelae. Discussion:We concluded that l-carnitine conjugated isovaleric acid earlier than glycine. Additionally, during the 10-year follow-up period, the patient displayed no clinical deterioration., 論文

Cornelia de Lange syndrome (CdLS) is a cohesinopathy caused by genetic variations. We present a female with SMC1A-associated CdLS with a novel SMC1A truncation mutation (p. Arg499Ter), transposition of the great arteries, and periodic intractable seizures from 40 months of age. A review of the literature revealed that a seizure-free period after birth of at least 15 months is required for these patients to be able to walk, irrespective of the epileptic course., 論文

Carnitine-acylcarnitine translocase (CACT) deficiency is a fatty acid ß-oxidation disorder of the carnitine shuttle in mitochondria, with a high mortality rate in childhood. We evaluated three patients, including two siblings, with neonatal-onset CACT deficiency and revealed identical homozygous missense mutations of p.Arg275Gln within the SLC25A20 gene. One patient died from hypoglycemia and arrhythmia at 26 months; his pathological autopsy revealed increased and enlarged mitochondria in the heart but not in the liver.

Here, we present the case of a 15-year-old Japanese girl with Dystonia 28, childhood-onset; DYT28 (MIM#606834) showing early-onset generalized progressive dystonia and status dystonicus. The patient was genetically undiagnosed and had not responded to various medications. By trio-based whole exome sequencing and in silico analyses, we identified a de novo heterozygous variant of KMT2B: NM_014727.2: c.7828C > T, p.(Arg2610Cys). Globus pallidus internus deep brain stimulation (GPi-DBS) therapy was considered; however, the therapy could not be performed due to the patient's poor nutritional status and repeated infections. GPi-DBS is considered to be an effective treatment for patients with KMT2B mutations, and genetic diagnosis is important before progression to status dystonicus.

A pilot study of newborn screening for Fabry disease was performed in Okinawa, Japan. A total of 2,443 neonates were screened using dried blood spot samples over 7 years starting in 2007. Of 13 neonates determined to have low alpha-galactosidase A (GLA) activity, one boy had a new missense mutation, p.G144D of the GLA gene. This mutation was considered to be a late-onset type, as evaluated based on plasma globotriaosylsphingosine levels and family history., 論文

A 10-year-old boy developed bilateral optic neuritis and myelitis after a suspected viral infection and appendicitis. Magnetic resonance imaging (MRI) showed multiple lesions in both optic nerves, the optic chiasm, and the spinal cord. Several small lesions were also observed in the cerebellum and cerebral white matter. The serum tested negative for anti-aquaporin (AQP)-4 antibody and positive for anti-myelin oligodendrocyte glycoprotein (MOG) antibody. The diagnosis was neuromyelitis optica spectrum disorder (NMOSD). Two courses of high-dose methylprednisolone were administered; however, only a small improvement in his visual acuity was achieved. He underwent 3 courses of plasma exchange to achieve sufficient visual acuity. After the serum anti-MOG antibody titer decreased to the cut-off level, oral prednisolone and azathioprine administration were also stopped, 10 months after onset. Recently, NMO and NMOSD cases positive for anti-MOG antibodies have been reported, which showed clinical features different from those of NMO cases positive for anti-AQP4 antibody. Although most of the reported cases responded to steroid therapy, plasma exchange was required in our case. Further analysis on larger numbers of cases is needed to establish treatments for anti-MOG antibody-positive NMO and NMOSD.

This paper analyzes the network performance of the Prodigy parallel AI machine, which is currently being developed. This machine is a multiprocessor system focusing on knowledge information processing problems with fine-grain parallelism, and thus it is adequate for solving the problems whose structures can be treated as networks. A base-m n-cube network is proposed as an appropriate interconnection network for these problems and the proposed network is employed for the Prodigy interconnection network. It deals with the suitability of the base-m n-cube network to the Prodigy machine and the possibility of making a large system in addition to network performance through comparisons with binary n-cube and mesh networks, where the performance figures are measured by simulation. The results of the comparison show that the base-m n-cube network is better than others for the Prodigy machine.

A method for fast screening of pesticide multiresidues in aqueous samples using dual stir bar sorptive extraction-thermal desorption-low thermal mass gas chromatography-mass spectrometry (dual SBSE-TD-LTM-GC-MS) has been developed. Recovery of 82 pesticides - organochlorine, carbamate, organophosphorous, pyrethroid and others - for the SBSE was evaluated as a function of octanol-water distribution coefficients (log K(o/w): 1.7-8.35), sample volume (2-20 mL), salt addition (0-30% NaCl), and methanol addition (0-20%). The optimized method consists of a dual SBSE performed simultaneously on respectively a 20-mL sample containing 30% NaCl and a 20-mL sample without modifier (100% sample solution). One extraction with 30% NaCl is mainly targeting solutes with low K(o/w) (log K(o/w)3.5) and another extraction with unmodified sample solution is targeting solutes with medium and high K(o/w) (log K(o/w)3.5). After extraction, the two stir bars are placed in a single glass desorption liner and are simultaneously desorbed. The desorbed compounds are analyzed by use of LTM-GC-MS with fast temperature programming (75 degrees C min(-1)) using a 0.18 mm i.d. narrow-bore capillary column and fast scanning (10.83 scan s(-1)) using quadrupole MS. The method showed good linearity (r(2)0.9900) and high sensitivity (limit of detection:10 ng L(-1)) for most of the target pesticides. The method was applied to the determination of pesticides at nanograms per liter levels in river water and brewed green tea.

A method for the simultaneous determination of 22 volatile organic compounds (VOCs), methyl- tert -butyl ether (MTBE), 1,4-dioxane, 2-methylisoborneol (2-MIB) and geosmin in water by headspace solid phase microextraction (SPME)-gas chromatography–mass spectrometry (GC–MS) is described. Three types of SPME fibers (carboxen (CAR)/polydimethylsiloxane (PDMS), divinylbenzene (DVB)/PDMS and 100-μm PDMS) were evaluated to achieve the method detection limits and linear range required in Japanese water regulation. A 100-μm PDMS was found to be the best coating to obtain a wide range of linearity for the target compounds in multiple-component system. CAR/PDMS and DVB/PDMS of adsorbent type fibers showed a narrow linear range for 22 VOCs, MTBE and 1,4-dioxane at the μg/l levels due to the limited capacity. The detection limits of this method were 0.01–0.05 μg/l for 22 VOCs, 0.01 μg/l for MTBE, 1.2 μg/l for 1,4-dioxane, 0.6 ng/l for 2-MIB and 0.3 ng/l for geosmin. The recoveries of 22 VOCs and MTBE from a river water sample spiked at 1 μg/l were between 93.7 and 104.0%, with R.S.D. values of between 1.7 and 9.5%. Those of 1,4-dioxane, 2-MIB and geosmin at 5 μg/l, 10 ng/l and 10 ng/l, respectively, were 109.1, 95.9 and 97.4%, with R.S.D. values of 2.0, 5.6 and 1.8%. The method provided linear range from 0.1 to 100 μg/l for 21 VOCs and MTBE, 0.1 to 50 μg/l for m , p -xylene, 5 to 100 μg/l for 1-4dioxane and 1 to 100 ng/l for 2-MIB and geosmin.

A method is described for the determination of 2-MIB and geosmin by gas chromatography-mass spectrometry (GC-MS) using stir bar sorptive extraction (SBSE). The detection limits using selected ion monitoring (SIM) were compared between solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE). Since polydimethylsiloxane (PDMS) is only available for stationary phase on the stir bar for SBSE, a 100-μm PDMS fiber was used for SPME due to the same sorption mechanism. The sensitivities of the SBSE method was 54 times higher for 2-MIB and 10 times higher for geosmin than those of the SPME method. The detection limits of the SBSE method evaluated in river water were 0.33 and 0.15 ng/L respectively for 2-MIB and geosmin. The reproducibilities (n = 5) were 9.2 and 3.7%, respectively, at 2 ng/L for 2-MIB and geosmin.

A method for the determination of estrogens (17alpha-estradiol, 17beta-estradiol, estrone, ethynyl estradiol, and estriol) as pentafluorobenzyl-trimethylsilyl (PFB-TMS) derivatives by gas chromatography-mass spectrometry (GC-MS) with negative-ion chemical-ionization (NICI) is described. The NICI of all the derivatives produced an intense [M-PFB]- ion as the base peak. The reagent gas (methane) flow-rate and the ion source temperature were determined to be 2.0 ml/min and 240 degrees C, respectively, for the optimized NICI-selected ion monitoring (SIM) conditions. The sensitivities of the PFB-TMS derivatives in the NICI mode were 8.0-130 times higher than those of the PFB-TMS derivatives in electron ionization (EI) mode, and 12-25 times higher than those of all the TMS derivatives in the EI mode. This method was applied to the analysis of estrogens in river water using a solid-phase extraction as the sample preparation. The recoveries of the target chemicals from a river-water sample spiked with standards at 2 ng/l level were 85.8-126.5% (RSD, 6.2-13.0%). The methodical detection limits ranged from 0.10 to 0.28 ng/l.

Gas chromatography-mass spectrometry (GC-MS) with a temperature-programmable pyrolyzer was used for the analysis of waterborne paints. Evolved gas analysis (EGA) profiles of the waterborne paints were obtained by this temperature-programmed pyrolysis directly coupled with MS via a deactivated metal capillary tube. The EGA profile suggested the optimal thermal desorption conditions for solvents and additives and the subsequent optimal pyrolysis temperature for the remaining polymeric material. Polymers were identified from pyrograms with the assistance of a new polymer library. The solvents were identified from the electron ionization mass spectra with the corresponding chemical ionization mass spectra. The additive was identified as zinc pyrithione by comparison with authentic standard. Zinc pyrithione cannot be analyzed by GC-MS as it is. However, the thermal decomposition products of zinc pyrithione could be detected. The information on the decomposition temperature and products was useful for the identification of the original compound.

A method for the trace level determination of 11 phenols as pentafluorobenzyl (PFB) derivatives by gas chromatography–mass spectrometry (GC-MS) with negative-ion chemical ionization (NICI) is described. First, the conditions for the PFB derivatisation of phenols were optimized and were found to be reaction temperature 80 °C and reaction time 5 h. Second, the detection limits using selected ion monitoring (SIM) were compared between trimethylsilylated (TMS) derivatives in the electron ionization (EI) mode and PFB derivatives in the NICI mode. The responses for the PFB derivatives in the NICI mode were 3.3–61 times higher than those of the TMS derivatives in the EI mode. The instrumental detection limits using NICI-SIM ranged from 2.6 to 290 fg. This method was applied to the analysis of phenols in river water using solid-phase extraction. The recoveries of the phenols from a river water sample spiked with standards at 100 ng l−1 with 2-chlorophenol, 4-chloro-3-methylphenol and pentachlorophenol and at 1000 ng l−1 with phenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2-nitrophenol, 2,4,6-trichlorophenol and 4-nitrophenol were 81.2–106.3% (RSD 5.1–8.0%), except for 2-methyl-4,6-dinitrophenol and 2,4-dinitrophenol, for which the recoveries were 5.8 and 4.2%, respectively, because water contained in the acetone eluate interfered with the derivatisation of these compounds with two electrophilic nitro groups.

A method for the determination of 24 organochlorine pesticides by gas chromatography-mass spectrometry (GC-MS) with negative-ion chemical-ionization (NICI) using programmable temperature vaporizer (PTV)-based large volume injection (LVI) is described. The ion source temperature was determined to be 150 °C for the optimized NICI-selected ion monitoring (SIM) conditions. PTV inlet parameters were also optimized. The sensitivities of the pesticides by splitless-GC-NICI-MS were approximately 7.8–360 times higher than those of the pesticides by splitless-GC-EI-MS. The sensitivities of the pesticides by LVI-GC-NICI-MS were over 80 times higher than those of the pesticides by spiltless-GC-NICI-MS. This method was applied to the determination of the pesticides in river water using micro liquid–liquid extraction as sample preparation. The recoveries of the pesticides from a river water sample spiked with standards at 2 ng l−1 and 20 ng l−1were 75–111% (RSD, 2.9–15%) and 92–105% (RSD, 0.5–5.6%), respectively. The methodical detection limits ranged from 0.004 to 2.2 ng l−1

Gas chromatograph/mass spectrometer (GC/MS) and gas chromatograph/atomic emission detector (GC/AED) with temperature programmable pyrolyzer were used for analysis of pressure sensitive adhesives in adhesive tapes. Evolved gas analysis (EGA) profile of the adhesives was obtained by this temperature-programmed pyrolyzer directly coupled with MS via a deactivated metal capillary tube. The EGA profile suggested the optimal thermal desorption condition for additives and the subsequent optimal pyrolysis temperature for the remaining polymeric material. Rubbers were identified from pyrograms with the assistance of a new polymer library. The additives were selectively detected by monitoring hetero elements and these screening results of GC/AED enabled one to easily find additive peaks in complex chromatograms of GC/MS with interference of tackifier. The additives were able to be identified by the corresponding GC/MS data. Furthermore, the EGA profile gave significant data for crosslinking agents by using specific ion monitoring.

外因性内分泌攪乱物質として疑われているアルキルフェノール類7種について,ペンタフルオロベンジル(PFB)誘導体とし負イオン化学イオン化(NICI)法を用いるガスクロマトグラフィー/質量分析法(GC/MS)による分析法を確立した。まず,アルキルフェノール類及びそのPFB誘導体について,電子イオン化(EI)法及びNICI法を用いる選択イオン検出法(SIM)により検出限界の比較を行った。PFB誘導体のNICI-SIM法ではモニターイオンとして各化合物のベースピークである(M-PFB)-イオンを用い,また試薬ガス(メタン)流量及びイオン源温度の最適条件を検討し,それぞれ2.5ml/min及び250°Cとした。EI-SIM法では,PFB誘導体とすることで誘導体化せずに測定した場合より2.1～6.3倍の感度を示し,更にPFB誘導体のNICI-SIM法では67～300倍もの高い感度を示した。NICI-SIM法により各アルキルフェノール類の検出限界は1.0～33pg/mlであった。検量線の直線性は1pg/ml～10ng/mlの範囲で,いずれの化合物も相関係数0.9995以上であった。また,繰り返し再現性(相対標準偏差,n=6)は,濃度10,100,1000pg/mlでそれぞれ3.6～6.8,2.3～4.9,2.4～3.5%であった。更に,河川水100mlに4-n-ペンチルフェノール,4-n-ヘキシルフェノール,4-n-ヘプチルフェノール及び4-n-オクチルフェノールは1ng,4-t-ブチルフェノール及び4-t-オクチルフェノールは10ng,ノニルフェノール(混合物)は500ngを添加し,本法で得られた回収率は77.9～102%であり,また繰り返し再現性(n=5)は相対標準偏差で4.1～12%であり,いずれも良好な結果を示した。

Aim: To clarify the evolution of an augmented startle reflex in Tay–Sachs disease and compare the temporal relationship between this reflex and brainstem evoked potentials. Subjects and methods: Clinical and electrophysiological data from 3 patients with Tay–Sachs disease were retrospectively collected. Results: The augmented startle reflex appeared between the age of 3 and 17 months and disappeared between the age of 4 and 6 years. Analysis of brainstem auditory evoked potentials revealed that poor segregation of peak I, but not peak III, coincided with the disappearance of the augmented startle reflex. A blink reflex with markedly high amplitude was observed in a patient with an augmented startle reflex. Conclusion: The correlation between the augmented startle reflex and the preservation of peak I but not peak III supports the theory that the superior olivary nucleus is dispensable for this reflex. The blink reflex with high amplitudes may represent augmented excitability of reticular formation at the pontine tegmentum in Tay–Sachs disease, where the pattern generators for the augmented startle and blink reflexes may functionally overlap.

The detailed matrices and their behaviors during pesticide residue analyses were clarified using a metabolomics analysis approach. The matrix profile was investigated using two different extraction solvents, acetone and acetonitrile. Acetone extracted the matrix components with a wide range of log P(O/W) values. Components with log P(O/W) values10, such as sterols and tocopherols, and components with log P(O/W) values3.2 were more extracted by acetone than by acetonitrile. In contrast, components with log P(O/W) values in the range from 3.2 to 10 were extracted by both acetone and acetonitrile at the same concentration level. The study also examined the difference in the column cleanup efficiency using a solid phase extraction (SPE). Florisil, silica gel, NH(2), PSA, and GCB were selected as representative columns for pesticide residue analysis, and acetone extraction of brown rice was selected in this experiment. Most of the matrix components were removed by either column, whereas monoacylglycerols, which are the components causing the matrix effect, were not removed by any column. Understanding such a detailed matrix behavior helps to develop a better analytical method for pesticide analysis using GC-MS.

Fenthion, fenthion sulfoxide, fenthion oxon sulfoxide and fensulfothion showed two different mass spectra in GC/MS, depending on their concentrations. The base peaks shifted to lower levels by 1 m/z at lower concentration, and no retention time shifts were observed. The "shifted base peaks" were not obtained by a general EI fragmentation. The product ion scan spectra of the "shifted base peaks" were coincident with those of molecular ions of their corresponding sulfides. These phenomena can be ascribed to the conversion of sulfoxide into sulfide by the dominant deoxidation reaction than EI fragmentation in an ion source. Adding polyethylene glycol 300 (PEG300) into a test solution prevented sulfoxide deoxidation. © The Japan Society for Analytical Chemistry.

Similarly to the ellipse angle the hyperbola angle is also introduced to express the roundness values of curve. While curves of various functions were previously examined with regard to the roundness values, general curves as parts of letterings are measured with an image scanner and a computer. The measured values are numerically converted to the roundness values. The method is applied to curvilinesr parts of letters C of letterings.

At present, the binary n-cube is considered to be interesting as an interconnection network for the highly parallel computers. Most of those networks, however, use the serial communication channel, which prevents the realization of satisfactory communication performance. From such a viewpoint, it is desired to construct an interconnection network with higher speed, higher versatility, and the easy implementation. The authors have already proposed the base-m n-cube as the interconnection network for the parallel AI machine Prodigy. This paper shows that the base-m n-cube is better than the binary n-cube in versatility and easy implementation. Furthermore, the authors developed Prodigy which utilizes the forementioned excellent property to connect 512 processors by the 8-bit width full duplex base-8 3-cube with a handshake. Two kinds of gate arrays are used in the implementation. It is shown as a result that the interconnection network can be constructed with the highest speed in the presently known cube-type highly parallel computers. It is verified by an actual measurement that the transfer performance is deteriorated only slightly by the collision in the random communication.

A method for determining the earthy and musty odors 2-methylisoborneol (2-MIB) and geosmin in drinking water using static headspace-GC-MS is described. To achieve lower detection limits, split ratio was optimized with ramped inlet pressure for large headspace sampling volume. The ramped inlet pressure, which held higher pressure (higher column flow rate) only during injection, allowed us to inject 3-mL volume to GC with very low split ratio (2:1). Although sequential analysis with a stainless steel ion source often changed the mass spectrum of 2-MIB, this spectral change was eliminated by using an inert ion source with a 6 mm drawout plate. The detection limits of this method were 0.36 and 0.14 ng/L, respectively, for 2-MIB and geosmin. The repeatabilities (n = 30) were 6.6 and 4.8%, respectively, at 1 ng/L for 2-MIB and geosmin.

A method for determining 68 pesticides in river water using stir bar sorptive extraction (SBSE)-thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS) is described. SBSE sampling was optimized for sample solution pH, salting-out and methanol addition. Although salting-out enhanced the ability of the method to extract most of the pesticides with low absolute recoveries, the absolute recoveries of four pesticides were not improved by salting-out. The detection limits of the method for the pesticides ranged from 0.2 to 20 ng/l. Analyte recoveries from a river water sample spiked with standards at 10 and 100 ng/l were 58.5–132.0% (RSD: 1.8–15.8%) and 61.0–121.3% (RSD: 1.4–20.2%), respectively.

A method for the determination of seven alkylphenols and bisphenol A by stir bar sorptive extraction (SBSE) with in situ derivatization-thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) is described. SBSE was performed with in situ acetylation and without derivatization for comparison. For 4-tert-butylphenol and bisphenol A, in situ acetylation improved the responses in SBSE-TD-GC-MS. The method detection limits ranged from 0.1 to 3.2 ng/l. The recoveries of the analytes from a river water sample spiked with standards at 10 and 100 ng/l were 85.3-105.9% (R.S.D., 3.0-11.0%) and 88.3-105.8% (R.S.D., 1.6-8.3%), respectively.

Changing of radiuses of curvature of a curve generally can match with that of either of conic sections when the change is continuous. With this feature arcs of functional curves are approximated by conic sections. It leads a method of numerical solution of functions being difficult otherwise to be solved. Because of the second degree, equations of conic section can be easily solved even if reversely. As a practical example reduction of the tristimulus value Y to the Munsell value V about colors, an equation of the fifth degree, is treated by the approximation with an equation of hyperbola.

The effect of a magnetic mirror field and ion motion in a high frequency gas discharge are investigated experimentally. The breakdown voltage in the mirror field is about ten percent less than that in uniform field. For both the uniform and the mirror magnetic fields, the minimum voltage of breakdown are observed at ωci/ω1, where ωci and ω are the frequencies of the ion cyclotron and the applied alternating electric field, respectively. These experimental results can be explained by a theory describing energy gain by ions and reduction in the number of electrons by diffusion.

The ellipse angle is examined to obtain numerical values of roundness of curve. Similarly to the ellipse angle the hyperbola angle is introduced also to express the roundness values of curve. An arc is matched with a similar shape of conic section by examining changes of radiuses of curvature along the curves. The angle value of the selected conic section can represent the roundness value of the arc. Changes of radiuses of curvature of conic section can completely cover those of all types of curves. It shows a fundamental characteristic of the conic section. The roundness values are applied to four curves of fundamental functions.

The frequency change of an ion acoustic wave by the finite boundary effect is examined experimentally and theoretically for an ion-beam plasma system. The ion acoustic and its harmonic-like waves can be excited by the finite boundary effect though the condition for the occurence of the usual two stream instability is not satisfied in an unbounded case. The frequencies of these waves decrease monotonically with the distance between two boundaries. Their frequencies change slightly by altering either the number density or the drift velocity of the ion beam. These characteristics are well explained by a dispersion relation derived from the linearized one-dimentional fluid equations on the boundary condition.

When the ion beam-plasma system is stimulated by a pump field with frequency f o near the ion Langmuir frequency f pi , the ion sound wave ( f s ) is enhanced and, at the same time, a new wave ( f b ) corresponding to the slow wave of the beam appears, and among their frequencies, the resonant condition, f b = f pi + f s , is satisfied. The resonant condition for the wave numbers, k b = k pi + k s , is ascertained by a test wave method. The test wave grows temporally at the frequencies coinciding with the frequencies of f b and f pi and, at the same time, the wave with the frequency of f b - f pi = f s grows also temporally. Their growing is affected by an ion beam energy, an initial intensity of the pump field and its frequency. These phenomena will be discussed with a nonlinear theory of the explosive instability for the coherent three-wave interaction.

Explosively unstable waves in an ion beam-plasma system are experimentally studied by use of the pump field method. The generated waves of an ion acoustic (γ) and a fast(α)- and a slow(β)-modes of the ion beam satisfy the resonance conditions both for frequency f β = f α + f γ and for wave number k β = k α + k γ . They at first all grow rapidly and attain their respective maximum intensities which are several times of their initial ones. There is an optimum intensity of the pump field to excite these three waves at the same time. The behaviors of their temporal growths are well explained by a nonlinear theory of coherent three-wave interaction.