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51.
Takashi Saitoh Jon Olav Vik Nils Chr. Stenseth Toshikazu Takanishi Shintaro Hayakashi Nobuo Ishida Masaaki Ohmori Toshio Morita Shigeru Uemura Masahiko Kadomatsu Jun Osawa Koji Maekawa 《Population Ecology》2008,50(2):159-167
We analysed the effects of Quercus crispula acorn abundance on the density dependence of the large Japanese wood mouse Apodemus speciosus using time series data (1992–2007). The data were obtained in a forest in northern Hokkaido, Japan, by live-trapping rodents
and directly counting acorns on the ground. Acorn abundance in one year clearly influenced the abundance of wood mice in the
following year in all models examined based on the Gompertz and Ricker model; in addition, the abundance of wood mice had
effects on the population. Acorn abundance influenced the strength of density dependence (intraspecific competition) of the
wood mouse population. When the abundance of acorns was high, density dependence was relaxed, and as a result the equilibrium
density at which the population growth rate decreased to zero became higher. Those effects of acorn abundance were regarded
as a nonlinear perturbation effect (sensu Royama 1992). The nonlinearity of density dependence was also detected; higher densities had stronger effects on population growth rates.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
52.
Toshio Ohmori Takashi Ikai Yasuji Minoda Koichi Yamada 《Bioscience, biotechnology, and biochemistry》2013,77(7):1599-1605
Two hundreds and fifty eight strains of microorganisms have been isolated from 526 samples (soil, leaf and river water gathered from 17 prefectures) by repeating liquid enrichment culture techniques in the medium containing biphenyl, diphenylmethane, diphenylethane or terphenyl, as the sole source of carbon.In the course of investigation, several strains were found to produce a large amount of γ-benzoylbutyric acid from biphenyl. Furthermore these strains utilized p-Cl-biphenyl and produced p-Cl-benzoic acid in good yield.Microorganisms obtained were almost short rod, motile bacteria, and fungi were also found from the screening medium of diphenylethane. 相似文献
53.
Aiko Shinko Takashi Agari Masahiro Kameda Takao Yasuhara Akihiko Kondo Judith Thomas Tayra Kenichiro Sato Tatsuya Sasaki Susumu Sasada Hayato Takeuchi Takaaki Wakamori Cesario V. Borlongan Isao Date 《PloS one》2014,9(7)
In clinical practice, deep brain stimulation (DBS) is effective for treatment of motor symptoms in Parkinson’s disease (PD). However, the mechanisms have not been understood completely. There are some reports that electrical stimulation exerts neuroprotective effects on the central nervous system diseases including cerebral ischemia, head trauma, epilepsy and PD, although there are a few reports on neuroprotective effects of spinal cord stimulation (SCS). We investigated the neuroprotective effects of high cervical SCS on PD model of rats. Adult female Sprague-Dawley rats received hour-long SCS (2, 50 or 200 Hz) with an epidural electrode at C1–2 level for 16 consecutive days. At 2 days after initial SCS, 6-hydroxydopamine (6-OHDA) was injected into the right striatum of rats. Behavioral evaluations of PD symptoms were employed, including cylinder test and amphetamine-induced rotation test performed at 1 and 2 weeks after 6-OHDA injection. Animals were subsequently euthanized for immunohistochemical investigations. In order to explore neurotrophic and growth factor upregulation induced by SCS, another cohort of rats that received 50 Hz SCS was euthanized at 1 and 2 weeks after lesion for protein assays. Behavioral tests revealed that the number of amphetamine-induced rotations decreased in SCS groups. Immunohistochemically, tyrosine hydroxylase (TH)-positive fibers in the striatum were significantly preserved in SCS groups. TH-positive neurons in the substantia nigra pars compacta were significantly preserved in 50 Hz SCS group. The level of vascular endothelial growth factor (VEGF) was upregulated by SCS at 1 week after the lesion. These results suggest that high cervical SCS exerts neuroprotection in PD model of rats, at least partially by upregulation of VEGF. SCS is supposed to suppress or delay PD progression and might become a less invasive option for PD patients, although further preclinical and clinical investigations are needed to confirm the effectiveness and safety. 相似文献
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56.
Takashi Hirayama 《Plant signaling & behavior》2014,9(10)
Poly(A) status is the major determinant of mRNA stability, even in endosymbiotic organelles. Poly(A) specific ribonuclease (PARN) is distributed widely among eukaryotes and has been shown to regulate the poly(A) status of cytoplasmic mRNA in various organisms. Surprisingly, our recent study revealed that PARN also directly regulates poly(A) status of mitochondrial mRNA in Arabidopsis. In this addendum, we discuss whether this mitochondrial function of PARN is common in plants and why PARN has been assigned such a unique function. 相似文献
57.
Takashi Hamano Yukimasa Mitsuhashi Yukio Matsuki 《Bioscience, biotechnology, and biochemistry》2013,77(10):2237-2243
A simple and selective gas chromatographic method was established for determining naturally occurring secondary amines. Secondary amines separated from foods by extraction with dichloro-methane and reextraction with hydrochloric acid were readily converted into the corresponding sulfonamides by reaction with benzenesulfonyl chloride under alkaline condition. Gas chromatography was carried out with a capillary coated with OV-101 and a flame photometric detector. Column temperature was programmed from 170 to 230°C at a rate of 5°C/min.The obtained sulfonamides were separated from one another within 40 min.Eleven secondary amines examined were added to 5 kinds of foods and recovered from them. The mean recovery rates were in the range 71.3% (dimethylamine)–99.8% (piperidine).The limits of detection varied from 0.002 ppm (dimethylamine) to 0.01 ppm (morpholine). 相似文献
58.
Kunisuke Nagamatsu Yasumasa Kido Tadao Terao Takashi Ishida Satoshi Toki 《Life sciences》1982,30(13):1121-1127
The ability of sulfhydryl compounds to provide protection against the acute toxicity of morphinone was investigated in mice. Subcutaneous administration of morphinone produced a reduction of hepatic non-protein sulfhydryl concentration. Pretreatments of mice with glutathione or cysteine significantly increased the survival rate of mice given a lethal dose of morphinone, whereas morphinone lethality was markedly potentiated by diethyl maleate. On the other hand, the administration of morphine produced a dose dependent reduction of hepatic non-protein sulfhydryl contents. However, neither glutathione nor cysteine protected mice from the acute toxicity of morphine. A possible explanation for these observations was proposed as follows: morphine is oxidized by morphine 6-dehydrogenase to morphinone, and the morphinone thus produced decreases the sulfhydryl contents in the liver. This mechanism is supported by the fact that morphinone reacts easily with glutathione and cysteine . 相似文献
59.
7-O-Galloyl-(+)-catechin and 3-O-galloylprocyanidin B-3, along with gambiriins A-1 and B-3 and four polygalloylglucoses, have been isolated fro 相似文献