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1.
Unilateral extirpation of the wing discs was performed on mid- and late-third instar larvae of Sarcophaga peregrina to investigate the regulation capacities of the thoracic discs. Out of 636 operated larvae, 175 became adult and all of them exhibited hemithoracic structures, lacking any adult structures in the operated side, which were normally produced from a wing disc. These findings suggest that the wing disc does not possess the capacity of bicentric regulation to produce the thoracic structures of the opposite side.  相似文献   
2.
Agricultural fields are an important anthropogenic source of atmospheric nitrous oxide (N2O) and nitric oxide (NO). Although many field studies have tested the effectiveness of possible mitigation options on N2O and NO emissions, the effectiveness of each option varies across sites due to environmental factors and field management. To combine these results and evaluate the overall effectiveness of enhanced‐efficiency fertilizers [i.e., nitrification inhibitors (NIs), polymer‐coated fertilizers (PCFs), and urease inhibitors (UIs)] on N2O and NO emissions, we performed a meta‐analysis using field experiment data (113 datasets from 35 studies) published in peer‐reviewed journals through 2008. The results indicated that NIs significantly reduced N2O emissions (mean: ?38%, 95% confidential interval: ?44% to ?31%) compared with those of conventional fertilizers. PCFs also significantly reduced N2O emissions (?35%, ?58% to ?14%), whereas UIs were not effective in reducing N2O. NIs and PCFs also significantly reduced NO (?46%, ?65% to ?35%; ?40%, ?76% to ?10%, respectively). The effectiveness of NIs was relatively consistent across the various types of inhibitors and land uses. However, the effect of PCFs showed contrasting results across soil and land‐use type: they were significantly effective for imperfectly drained Gleysol grassland (?77%, ?88% to ?58%), but were ineffective for well‐drained Andosol upland fields. Because available data for PCFs were dominated by certain regions and soil types, additional data are needed to evaluate their effectiveness more reliably. NIs were effective in reducing N2O emission from both chemical and organic fertilizers. Moreover, the consistent effect of NIs indicates that they are potent mitigation options for N2O and NO emissions.  相似文献   
3.
AKIYAMA, S., WAKABAYASHI, M. & OHBA, H., 1992. Chromosome evolution in Himalayan Impatiens (Balsaminaceae). Chromosome numbers and karyotypes have been investigated in species of Himalayan Impatiens . In addition to confirming previous chromosome counts, the presence of a tetraploid taxon ( I. exilis) is revealed. In central and east Nepal species with x = 9 are more common than those with other basic numbers and this number is shown to be one of the most frequent numbers in the genus. Most species with x = 9 have a bimodal karyotype. The species relationships are discussed.  相似文献   
4.
We investigated microbial methanogenesis and community structure based on 16S rRNA gene sequences from a coal seam aquifer located 843–907 m below ground level in northern Japan; additionally, we studied the δ13C and δ2H (δD) of coal‐bed gases and other physicochemical parameters. Although isotopic analysis suggested a thermocatalytic origin for the gases, the microbial activity and community structure strongly implied the existence of methanogenic microbial communities in situ. Methane was generated in the enrichment cultures of the hydrogenotrophic and methylotrophic microorganisms obtained from coal seam groundwater. Methanogen clones dominated the archaeal 16S rRNA gene libraries and were mostly related to the hydrogenotrophic genus Methanoculleus and the methylotrophic genus Methanolobus. Bacterial 16S rRNA gene libraries were dominated by the clones related to the genera Acetobacterium and Syntrophus which have a symbiotic association with methanogens. LIBSHUFF analysis revealed that N2 gas injected into the coal seam (for enhanced methane production) does not affect the coverage of archaeal and bacterial populations. However, amova analysis does provide evidence for a change in the genetic diversity of archaeal populations that are dominated by methanogens. Therefore, N2 injection into the coal seam might affect the cycling of matter by methanogens in situ.  相似文献   
5.
In most temperate insects, diapause strategies and voltinism generally exhibit latitudinal clines, supporting the concept that they represent adaptations to climate. In contrast, in the satyrine butterfly Ypthima multistriata Butler, local populations with different voltinism patterns are geographically intermingled, suggesting that life‐history traits related to diapause may differ even between geographically and phylogenetically close populations. In this study, we experimentally examined the critical photoperiod for diapause induction and the larval developmental period in two univoltine and two bivoltine populations of Y. multistriata, all of which inhabit virtually the same latitude (34.652–34.750°N). We found that the critical photoperiod for diapause induction was longer in the univoltine populations than in the bivoltine populations. Moreover, the larval period under the long day length treatment was different among populations in both sexes, although significant differences were also detected between populations with the same voltinism. These results indicate that in Y. multistriata, life‐history traits related to diapause can not be attributed merely to climatic conditions such as temperature or day length, which depend largely on latitude. Therefore, we suggest that biotic elements, such as leaf toughness, as well as abiotic elements should be taken into account in attempts to explain the enigmatic pattern of geographic variation in the diapause strategies of Y. multistriata.  相似文献   
6.
In order to construct an anlageplan of the imaginal disc, various fragments of the wing disc from mature larvae of Sarcophaga peregrina were implanted into host larvae of the same age. The implants were metamorphosed with the host and the differentiated adult structures were analyzed.
On the basis of the results obtained from the transplanted disc fragments, a fate map of the wing disc was satisfactorily constructed.
The fate map of S. peregrina is similar to an earlier study of Drosophila , but the PAA, PWP, and AP are located in different positions from those of Drosophila .  相似文献   
7.
We investigated the diversity and distribution of archaeal and bacterial 16S rRNA gene sequences in deep aquifers of mid‐ to late Miocene hard shale located in the northernmost region of the Japanese archipelago. A major fault in the north‐west–south‐east (NW–SE) direction runs across the studied area. We collected three groundwater samples from boreholes on the south‐west (SW) side of the fault at depths of 296, 374 and 625 m below ground level (m.b.g.l.) and one sample from the north‐east (NE) side of the fault at a depth of 458 m.b.g.l. The groundwater samples were observed to be neutral and weakly saline. The total microbial counts after staining with acridine orange were in the order 105?106 cells mL?1 and 103 cells mL?1 in the aquifers to the SW and to the NE of the fault, respectively. A total of 407 archaeal and bacterial 16S rRNA gene sequences (204 and 203 sequences, respectively) were determined for clone libraries constructed from all groundwater samples. Phylogenetic analyses showed that the libraries constructed from the SW aquifers were generally coherent but considerably different from those constructed from the NE aquifer. All of the archaeal clone libraries from the SW aquifers were predominated by a single sequence closely related to the archaeon Methanoculleus chikugoensis, and the corresponding bacterial libraries were mostly predominated by the sequences related to Bacteroidetes, Firmicutes and δ‐Proteobacteria. In contrast, the libraries from the NE aquifer were dominated by uncultured environmental archaeal clones with no methanogen sequences and by β‐proteobacterial clones with no sequences related to Bacteroidetes and δ‐Proteobacteria. Hence, the possible coexistence of methanogens and sulphate reducers in Horonobe deep borehole (HDB) on the SW side is suggested, particularly in HDB‐6 (374 m.b.g.l.). Moreover, these organisms might play an important geochemical role in the groundwater obtained from the aquifers.  相似文献   
8.
In 2009 the WPA President established a Task Force that was to examine available evidence about the stigmatization of psychiatry and psychiatrists and to make recommendations about action that national psychiatric societies and psychiatrists as professionals could do to reduce or prevent the stigmatization of their discipline as well as to prevent its nefarious consequences. This paper presents a summary of the Task Force’s findings and recommendations. The Task Force reviewed the literature concerning the image of psychiatry and psychiatrists in the media and the opinions about psychiatry and psychiatrists of the general public, of students of medicine, of health professionals other than psychiatrists and of persons with mental illness and their families. It also reviewed the evidence about the interventions that have been undertaken to combat stigma and consequent discrimination and made a series of recommendations to the national psychiatric societies and to individual psychiatrists. The Task Force laid emphasis on the formulation of best practices of psychiatry and their application in health services and on the revision of curricula for the training of health personnel. It also recommended that national psychiatric societies establish links with other professional associations, with organizations of patients and their relatives and with the media in order to approach the problems of stigma on a broad front. The Task Force also underlined the role that psychiatrists can play in the prevention of stigmatization of psychiatry, stressing the need to develop a respectful relationship with patients, to strictly observe ethical rules in the practice of psychiatry and to maintain professional competence.  相似文献   
9.
10.
Transgenic fish carrying a reconstructed mouse tyrosinase gene, mg-Tyrs-J, were produced by microinjecting the gene into the oocyte nucleus of an orange-colored variant of medaka (Oryzias latipes). Of 64 oocytes microinjected and subsequently inseminated, 13 embryos developed normally beyond hatching and three of them exhibited brown skin pigmentation in the adult as was commonly observed in the wild type of this species. Light and electron microscopic examination disclosed a ubiquitous distribution of typical melanophores in the skin of these transgenic fish. Judging from their population density and distribution pattern, it was presumed that melanogenesis in these fish was elicited in amelanotic melanophores that resided in the skin of the orange-colored fish of this variant. Immunofluorescence with use of the anti-mouse tyrosinase antiserum lacking reactivity to medaka tyrosinase clearly disclosed that the gene introduced was expressed in the melanophores of transgenic fish. Crosses of female transgenic fish and males from an orange-colored variant yielded offspring exhibiting wild-type or orange-colored pigmentation in a ratio of 1:1, thus implying that mg-Tyrs-J integrated into the medaka genome behaves like a dominant gene. Little melanogenesis was observed in xanthophores, leucophores and iridophores in transgenic fish, suggesting possible specificity in recognition of teleostean cell types (i.e., melanophores) by the regulatory region of the mouse tyrosinase gene.  相似文献   
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