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Volume 55, Issue 4
Displaying 1-7 of 7 articles from this issue
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Yoko YAMAMOTO, Kazuaki TANAKA, Noboru KOMORI1994 Volume 55 Issue 4 Pages 241-245
Published: October 28, 1994
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSOdor compounds produced by myxobacterial strains isolated from lake water and sediments were studied. The major odor compound was identified as geosmin, which was produced in culture medium in a range from 7 to 270 μg⋅l-1. The geosmin content in cells varied with growth conditions. Higher concentrations were observed in the exponential phase, and its concentration decreased in the stationary phase of growth. The loss of geosmin content in cells was accompanied by an increase in geosmin released into the media.View full abstractDownload PDF (255K) -
Yoshihiro MIZUKAMI, Taku KOMORI, Munetsugu KAWASHIMA1994 Volume 55 Issue 4 Pages 247-255
Published: October 28, 1994
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSPrecipitation samples were collected every 24 hours during three years from December 1990 to November 1993 at Otsu, Shiga, Japan. Dissolved ions such as H+, Na+, K÷, Mg2+, Ca2+, Cl-, NO2-, NO3-, SO42- and H2PO4-, and conductivity were analyzed in 324 samples obtained. pH ranged from 3.9 to 5.9 and the average was 4.45. In 89% of samples, the pH values were less than 5.0. All of the ions show big fluctuations in concentration with coefficients of variation from 97 to 194%. Good correlation between [H+] + [NH4+] + [Ca2+]nss and [SO42-]nss+ [NO3-] implies that acidification by sulfuric and nitric acids and neutralization by bases such as ammonia and calcium compounds determine the pH of precipitation. As a result of principal components analysis, dissolved ions were divided into three groups. The first group, including H+, SO42-, NO3- and NH4+, was assigned to originate in acids and a base which come from gas sources ; the second one, including Na+, Mg2+ and Cl-, derives mainly from sea-salts ; the third one, including Ca2+, K+ and H2PO4-, possibly originates from soil.View full abstractDownload PDF (455K) -
Masahiro OCHIAI, Yuuichi SHIMIZU1994 Volume 55 Issue 4 Pages 257-266
Published: October 28, 1994
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSWater samples taken from the lower part of the Tsurumi River were measured for carbohydrates, amino acids, and chlorophyll pigments by GLC and HPLC. These particulate organic compounds were classified in two categories using arabinose and chlorophyll pigments as marker : One fraction was supplied from the upper part of the TR-07 (Takano-Ohashi) and the other was produced in situ by algae in the river water. Two fractions from the particulate carbohydrates and amino acids concentrations were calculated at each sampling station. We observed that the behavior of the particulate carbohydrates supplied from the upper part was different from that of the particulate amino acid in the estuary of the Tsurumi river. The particulate carbohydrates decreased slowly from TR-07 to lower part and the particulate amino acids decreased sharply at TR-06 (Sueyoshi-Bashi). These two compounds may have different susceptibility to ionic strength change.View full abstractDownload PDF (510K) -
Teppei SEKI, Makoto TANIGUCHI1994 Volume 55 Issue 4 Pages 267-277
Published: October 28, 1994
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSIn order to clarify eigen oscillations of water level in Lake Biwa, water-level oscillations observed are compared with those obtained from a numerical method. Analyses of water-level oscillations measured at Ayamehama in the North Basin and at Chagasaki in the South Basin were performed by using Fast Fourier Transform (FFT) Method. Numerical analyses of eigen oscillations in Lake Biwa have been done by using Finite Element Method (FEM). Seven modes of eigen oscillation at periods longer than 30 minutes can be distinguished. Dominant periods of the oscillation obtained by FFT method agree well with those obtained by FEM.View full abstractDownload PDF (681K) -
Keishi TAKANO, Shuji HINO1994 Volume 55 Issue 4 Pages 279-286
Published: October 28, 1994
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDense water blooms of blue-green algae (Microcystis aeruginosa and Apha-nizomenon flos-aquae) had been observed in hypertrophic Lake Barato in the 1980s, but have not reappeared since 1990. Instead of these water blooms, diatoms (Melosira spp. and Cyclotella spp.) have dominated in summer. Orthophosphate (PO4-P) had been detected throughout the year, but since 1990 has apparently become depleted during May and June. In 1991, PO4-P concentrations increased in August and/or September, as did the biomass of blue-green algae (Anabaena spiroides or Phormidium spp.). These observations suggested that diatoms adapted to higher phosphorus limitation under conditions of low water temperature and high silicate concentration. Diatoms thus continued their dominance over blue-green algae because the latter could not grow in early summer due to a lack of PO4-P, most of which was taken up by the diatoms.View full abstractDownload PDF (468K) -
Toshio OHONO, Norio HAYAKAWA1994 Volume 55 Issue 4 Pages 287-295
Published: October 28, 1994
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThe cyclic change of water temperature in a reservoir can be predicted by the Autoregressive Model (AR model). In order to assess the validity of the short-range forecasting method by the AR model of order 2, we introduce a new parameter to compare the autoregressive model forecasting with the persistence model forecasting. The AR model forecasting results in an inprovement of about 35% in the root meansquare error over the persistence method which predicts no change at every step. We also applied the AR model to the reservoir of Yahagi 1st Dam, and obtained the temporal change with the period of 4-5 days in water temperature.View full abstractDownload PDF (491K) -
2. Glossosomatidae, Beraeidae, Odontoceridae and MolannidaeTakao NOZAKI, Tomiko ITO, Kazumi TANIDA1994 Volume 55 Issue 4 Pages 297-305
Published: October 28, 1994
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThis second in a series of checklists of Japanese Trichoptera deals with 20 species (4 genera) of Glossosomatidae, one species of Beraeidae, 4 species (2 genera) of Odontoceridae and 3 species (2 genera) of Molannidae. The following species were wrongly recorded from Japan due to misidentification of larvae ; Agapetus comatus PJCTET, Agapetus fuscipes CURTIS, Glossosoma boltoni CURTIS and Glossosoma vernale PICTET. We designated as valid two names, Agapetus budoensis KOBAYASHI and Glos-sosoma uogatanum KOBAYASHI, from the original descriptions.
In Glossosomatidae, we suggested five taxonomical problems : description of Agapetus annulicornis (MATSUMURA) was insufficient for specific identification ; many descriptions of larvae were also insufficient for specific and, at times, generic identification ; 3)relationships of subgenera Mystroglossa and Synafophora should be clarified ; Glossosoma inops (TSUDA) should be compared with similar species in adjacent districts ; 5)an unnamed 'species' recorded from Hokkaido has not yet been identified, though the fine figures of male genitalia were provided.
In Odontoceridae, three taxonomical problems remain : 1)geographical variations of Perissoneura species, P. paradoxa McLACHLAN and P. similis BANKS, have not been studied ; 2)the holotype of Psilotreta armata MARTYNOV awaits reexamination ; 3) status of one unnamed 'species' of Psilotreta from the Ryukyus is not yet described.
In Molannidae, the type material of Molanna nervosa ULMER should be reexamined and compared with materials recently obtained from Hokkaido and Honshu.View full abstractDownload PDF (587K)
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