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1.
  • 1.1. Polyamines were extracted from the guts and ovaries of the sea urchin Anthocidoris crassispina, and the guts and flesh of the sea cucumber Stichopus japonicus and the sea squirt Halocynthia roretzi, the oyster Crassostrea gigas and the short-necked clam Tapes philippinarum, and analyzed by ion-exchange high-performance liquid chromatography and gas chromatography-mass spectrometry.
  • 2.2. Norspermidine and norspermine as well as putrescine, cadaverine, spermidine, spermine and agmatine were the ubiquitous polyamines in these invertebrates. These results suggest the widespread distribution of norspermidine and norspermine in invertebrates.
  • 3.3. Thermopentamine, thermohexamine and homothermohexamine were found in the sea urchin. This in the first report on the occurence of thermopentamine and hexaamine in invertebrates.
  • 4.4. Homospermidine, canavalmine, aminopropylhomospermidine, homospermine, caldopentamine, homocaldopentamine and aminopropylcanavalmine were found in the sea cucumber. Homospermidine, aminopropylhomospermidine and homospermine were found in the squirt. This is the first report on the occurence of canavalmine, aminopropylhomospermidine, homospermine, homocaldopentamine and aminopropylcanavalmine in invertebrates.
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2.
Maturation of walleye by age, size and surplus energy   总被引:3,自引:0,他引:3  
The probability of annual sexual maturation by male and female walleye Stizostedion vitreum was related to age, size and an index of condition, I VF=[arcsine(visceral fat)0·5(body mass)−0·5]. Most males first matured at ages 2 and 3 years; size explained first maturation, but condition explained later maturation. In contrast, most females first matured at ages 4 and 5 years; maturity of females was more dependent upon condition. Maturity of females at ages 4 and 5 years was significantly correlated with average I VF of the population ( PI VF). The size reached by age 2 years (early growth) was correlated with the PI VF. Growing degree-days, Secchi depth, latitude and lake morphology were not correlated with the PI VF. Annual variations in female spawning stock size were related to the condition of the females, presumably reflecting the net acquisition of energy in the preceding growing season. Annual variations within lakes in the net acquisition of energy may exceed the variations in energy availability between lakes, dictated by lake morphology and geography. Thus, assessment of condition could be used to predict annual potential spawning stock size and egg production.  相似文献   

3.
《Plains anthropologist》2013,58(76):85-95
Abstract

Eleven boulder configurations in Saskatchewan were examined in 1975 for possible astronomical alignments. Three were found to contain alignments to summer solstice phenomena. Ethnographic interviewing failed to discover any tradition of solstice marking in the historic tribes of the Northwestern Plains, but did suggest that the boulder configurations may have been constructed for the private observations of calendar-keeping shamans. Ethnoarchaeological mapping of a 1975 Sun Dance camp revealed that the ceremonial structures were aligned to sunrise, but whether this was deliberate, and if deliberate, traditional, could not be determined.  相似文献   

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Whole animal oxygen consumption rates and plasma constituents were determined in the tilapia O. mossambicus , acclimated for 1 month in fresh water, sea water, and 1·6 × sea water. Oxygen consumption rates for the three water salinities were: 177·2 ± 16·86, 78·6 ± 2·32, and 195·4 ± 15·39 mg O2 kg−1 h−1 (means ± 1 s.e.), respectively. Plasma prolactin (tPRL188) concentration was significantly lower in 1·6 × sea water compared to fresh and sea water. There were no significant differences among mean plasma cortisol concentration and lysozyme activity. Ventilation was significantly higher in fish in sea water compared to the fish in fresh and 1·6 × sea water. The lowest oxygen consumption rates were found in fish acclimated to sea water. That salinity is probably closest to the brackish waters from which they were captured in the wild, and this agreement likely reflects the selection for optimal morphological and physiological characteristics to live in that environment.  相似文献   

10.
The EU Water Framework Directive (WFD), EU Nitrate Directive and EU Rural Development Policy (RDP) aim to improve water quality. The nutrient content of water can be decreased by reducing nitrogen emission. In this article a novel approach is applied to the evaluation of the impact of Agri Environmental Measures (AEM), which are part of axis 2 of the EU Rural Development Programme. The spending on AEM is linked to the reduction of nitrogen surplus, and hence, to the improvement of water quality. Reduction of nitrogen surplus is considered as a beta convergence process, in which the nitrogen surplus of EU member states converges to a steady state level. The convergence is tested, applying spatial econometrics on a panel data set of EU member states. The development over time of nitrogen surplus is explained applying the conditional beta convergence methodology. To allow for varying steady state nitrogen surpluses, structural variables are added to the analysis. RDP spending on AEM was added as structural variable to evaluate whether they affect the reduction of nitrogen surplus. The fixed effects panel data specification was tested to be the best model and preferred over spatial econometric specifications. A significantly negative effect is found between AEM expenditures and nitrogen surplus. Based on these estimation results it can be concluded that spending on AEM affects the convergence of nitrogen surplus towards a steady state level. A causal relationship cannot be tested with data on EU Member State level and additional analysis at smaller spatial level is warranted.  相似文献   

11.
Pigments absorbing 350–1,050 nm radiation have had an important role on the Earth for at least 3.5 billion years. The ion pumping rhodopsins absorb blue and green photons using retinal and pump ions across cell membranes. Bacteriochlorophylls (BChl), absorbing in the violet/blue and near infra red (NIR), power anoxygenic photosynthesis, with one photoreaction centre; and chlorophylls (Chl), absorbing in the violet/blue and red (occasionally NIR) power oxygenic photosynthesis, with two photoreaction centres. The accessory (bacterio)chlorophylls add to the spectral range (bandwidth) of photon absorption, e.g., in algae living at depth in clear oceanic water and in algae and photosynthetic (PS) bacteria in microbial mats. Organism size, via the package effect, determines the photon absorption benefit of the costs of synthesis of the pigment–protein complexes. There are unresolved issues as to the evolution of Chls vs. BChls and the role of violet/blue and NIR radiation in PS bacteria.  相似文献   

12.
Abstract

Norway is involved in two maritime boundary disputes with the Soviet Union. In relation to Svalbard, the Soviet Union argues that the archipelago has a continental shelf and an exclusive economic zone (EEZ) of its own to which all parties to the Svalbard Treaty have equal access. This is disputed by Norway, which maintains that such a view of the matter implies an expansive interpretation of the Svalbard Treaty for which there is no support in international legal practice. In the Barents Sea there is a continuing dispute between Norway and the Soviet Union over the proper location of the continental shelf and EEZ boundaries. This article sets out some of the reasons behind the different arguments on which the two base their respective cases, and the reasons why Norway in the absence of a delineated boundary has refused to accept Soviet proposals for economic cooperation in the disputed ocean area. Major emphasis is placed on the confluence of several circumstances inter alia, geopolitical and historical factors, a strongly asymmetrical power relationship, and legal ambiguity.  相似文献   

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The phospholipid composition of organs and tissues was investigated in representatives of five phyla of marine invertebrates: Annelida (Chaetopterus variopedatus, Serpula vermicularis), Echiuroidea (Urechis unicinctus), Sipunculoidea (Phascolosoma japonicum), Mollusca (Gastropoda: Tectonatica janthostoma, Neptunea polycostata; Bivalvia: Mactra sulcataria, Peronidia venuloza, Patinopecten yessoensis, Crenomytilus grayanus; Cephalopoda: Octopus conispadiceus, Todarodes pacificus), and Arthropoda (Paralythodes camtschatica, Erimacrus isenbekii, Hemigrapsus sanguineus, Pinixa rathbunii). The specificity of phospholipid distribution was shown to be related to the taxonomic position of marine invertebrates and functional properties of their organs and tissues. In Echiuroidea, Sipunculoidea, and Arthropoda, ceramide aminoethylphosphonate was found only in the digestive organs. This suggests an exogenous origin of this phospholipid.  相似文献   

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We summarize the research on Asian Sun catfish, Horabagrus brachysoma (Günther), an endemic and threatened freshwater catfish from Western Ghats of India, and provide a comprehensive review of its taxonomy, distribution, biology, population, conservation and aquaculture. Although described in 1864, the taxonomy of H. brachysoma, particularly its familial affinities, continues to be in flux. The species, originally described from the erstwhile ‘state of Cochin’ in present day Kerala State, India, has a current distribution ranging from southern Kerala (8°N) to southern Maharashtra (16°N), where they are found in lowland westward-flowing rivers, as well as natural freshwater lakes and backwaters. As a much relished food fish, H. brachysoma is exploited throughout its range, predominantly through an unmanaged artisanal fishery. Although there are no scientific estimates of either the status or trends in overall population of this endemic catfish, anecdotal evidence and fisher-knowledge suggests drastic declines of several local populations. The fishery for H. brachysoma in the Periyar and Achenkovil rivers in the State of Kerala has been documented to be unsustainable. As a result of an overall population decline of 35 % due to overharvest and habitat loss, H. brachysoma is assessed as ‘Vulnerable’ on the IUCN Red List of Threatened Species?. Primary research on various aspects of feeding, reproductive biology and demography has generated a wealth of information on the species, but this knowledge is yet to be utilized for the development and implementation of in situ conservation or management plans. In view of its high consumer demand, efficient biological and eco-physiological characteristics, as well as the availability of a captive breeding technology, H. brachysoma is considered an emerging species for small-scale aquaculture. Priorities for scientific research to address knowledge-gaps, as well as strategies for effective conservation of this threatened freshwater catfish are discussed.  相似文献   

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To be competitive with common plastics, the production costs of polyhydroxyalkanoates (PHAs) have to be minimized. Biotechnological polymer production occurs in aerobic processes; therefore, only about 50% of the main carbon sources and even a lower percentage of the precursors used for production of co-polyesters end up in the products wanted. A second cost factor in normally phosphate-limited production processes for PHAs is the costs for complex nitrogen sources. Both cheap carbon sources and cheap nitrogen sources are available from agricultural waste and surplus materials and make a substantial contribution for minimizing PHA production costs. In this study, fermentations for PHA production were carried out in laboratory-scale bioreactors on hydrolyzed whey permeate and glycerol liquid phase from the biodiesel production using a highly osmophilic organism. Without any precursor, the organism produced a poly[3(hydroxybutyrate-co-hydroxyvalerate)] copolyester on both carbon sources. During the accumulation phases, a constant 3-hydroxyvalerate content of 8-10% was obtained at a total PHA concentration of 5.5 g/L (on hydrolyzed whey permeate) and 16.2 g/L (glycerol liquid phase). In an additional fermentation, an expensive nitrogen source was substituted by meat and bone meal beside the glycerol liquid phase as a carbon source, resulting in a final PHA concentration of 5.9 g/L.  相似文献   

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Tourism climate and thermal comfort in Sun Moon Lake,Taiwan   总被引:1,自引:0,他引:1  
Bioclimate conditions at Sun Moon Lake, one of Taiwan’s most popular tourist destinations, are presented. Existing tourism-related climate is typically based on mean monthly conditions of air temperature and precipitation and excludes the thermal perception of tourists. This study presents a relatively more detailed analysis of tourism climate by using a modified thermal comfort range for both Taiwan and Western/Middle European conditions, presented by frequency analysis of 10-day intervals. Furthermore, an integrated approach (climate tourism information scheme) is applied to present the frequencies of each facet under particular criteria for each 10-day interval, generating a time-series of climate data with temporal resolution for tourists and tourism authorities.  相似文献   

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