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We present the results of our 14th horizon scan of issues we expect to influence biological conservation in the future. From an initial set of 102 topics, our global panel of 30 scientists and practitioners identified 15 issues we consider most urgent for societies worldwide to address. Issues are novel within biological conservation or represent a substantial positive or negative step change at global or regional scales. Issues such as submerged artificial light fisheries and accelerating upper ocean currents could have profound negative impacts on marine or coastal ecosystems. We also identified potentially positive technological advances, including energy production and storage, improved fertilisation methods, and expansion of biodegradable materials. If effectively managed, these technologies could realise future benefits for biological diversity.  相似文献   

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It is known that cobalamin (Cbl) deficiency damages myelin by increasing tumor necrosis factor (TNF)-α and decreasing epidermal growth factor (EGF) levels in rat central nervous system (CNS), and affects the peripheral nervous system (PNS) morphologically and functionally. It is also known that some polyneuropathies not due to Cbl deficiency are connected with increased TNF-α levels, and that various cytokines (including TNF-α) and growth factors regulate the in vitro synthesis of normal prions (PrPCs). Given that there is extensive evidence that PrPCs play a key role in the maintenance of CNS and PNS myelin, we investigated whether the PrPC octapeptide repeat (OR) region is involved in the pathogenesis of rat Cbl-deficient (Cbl-D) polyneuropathy. After intracerebroventricularly administering antibodies (Abs) against the OR region (OR-Abs) to Cbl-D rats to prevent myelin damage and maximum nerve conduction velocity (MNCV) abnormalities, and PrPCs to otherwise normal rats to reproduce PNS Cbl-D-like lesions, we measured PrPC levels and MNCV of the sciatic and tibial nerves. PrPC and TNF-α levels were increased in sciatic and tibial nerves of Cbl-D and saline-treated rats, and the OR-Abs normalized the myelin ultrastructure, TNF-α levels, and MNCV values of the sciatic and tibial nerves of Cbl-D rats. The same peripheral nerves of the otherwise normal PrPC-treated rats showed typical Cbl-D myelin lesions, significantly increased TNF-α levels, and significantly decreased MNCV values. These findings demonstrate that Cbl deficiency induces excess PrPCs and thereby excess OR regions, which seem to be responsible for the PNS myelin damage, as has recently been found in the case of CNS myelin damage [66]. Furthermore, excess TNF-α is also involved in the pathogenesis of Cbl-D polyneuropathy. In conclusion, we have extended the list of prion diseases by adding one caused by excess PrPCs and the polyneuropathies related to excess TNF-α.  相似文献   

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新的生物课程标准对生物教学提出了新的要求,生物实验室的建设也必须做出相应的改变,使之更好地为新形势下的生物教学服务。  相似文献   

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A new model for biological pattern formation   总被引:2,自引:0,他引:2  
Various non-equilibrium growth models have been used to explore the development of morphology in biological systems. Here we review a class of biological growth models which exhibit fractal structures and discuss the relationship of these models to a variety of other phenomena.  相似文献   

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An entirely online upper‐division university marine invertebrates course modeled after a field experience‐intensive course that also provided interaction with live animals and research experience was offered at Rosario Beach Marine Laboratory in the summer of 2020. We describe online methods we used for providing field experiences to students participating online, as well as a workstation and interactive method for identification and detailed anatomical examination of live macroinvertebrates with students. Students were also involved as active participants in a field research project. Nearly all of the equipment involved is inexpensive or readily available in most university biology laboratories or classrooms.  相似文献   

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A new version of the molecular graphics program FRODO was developed to allow the range of Tektronix graphics stations to be used for molecular modeling and crystallographic applications. The work was divided into two parts: first, the universal molecular modeling graphic package (Tek_MMGP) was written to enable basic modeling operations for Tektronix stations. Second, all routines of FRODO involving computer graphics were modified to fit the new hardware environment, and linked with Tek_MMGP. The resulting package, Tek_FRODO, has been used successfully for crystallographic refinement in several projects. The program, written in FORTRAN, is ready to be ported to any of Tektronix 3D graphics stations; it is available from the authors on request.  相似文献   

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BIOS is a computerised database system for holding species distributiondata. Emphasis has been placed on the flexibility in which storedinformation can be accessed. Multiple retrieval pathways permitsimple enquiries to be answered or complicated interrogationsequences for statistical treatment of data. The structuralorganisation of the database is explained and details of itscontents are listed. Examples of applications in the fieldsof zoogeography and ecology are given together with illustrations.  相似文献   

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Hitherto undescribed strata containing well-preserved fish occur at the base of the Tortonian, Upper Coralline Limestone Formation at Il Fawwara, Malta. The major elements of the fish fauna are Bregmaceros albyi, Syngnathus sp.a sciaenid and indeterminate members of the Percoidei. Collectively these fish are considered to represent part of a shallow marine assemblage tolerant to both sedimentation and salinity fluctuations.Detailed work on the associated fossils and sediments leads to the conclusion that this bed accumulated during a brief interval when shallow water sediments and biota were intermittently carried into a small shelf depression by a succession of density flows. Evidence is presented to suggest that these flows were set in motion by periodic storm activity affecting shallow water areas adjacent to a carbonate coastline of low relief.  相似文献   

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Aqueous extracts from 42 species of Vietnamese marine macroalgae, including 17 Chlorophyta, 22 Rhodophyta, and three Phaeophyta species, were examined for hemagglutination activity using native and enzyme-treated different animal and human erythrocytes. All extracts agglutinated at least one type of erythrocytes tested. Strong activity was detected in extracts from four Chlorophyta (Caulerpa serulata var. boryana, Caulerpa sertularioides f. longipes, Halimeda velasquezii, and Halimeda discoidea) and two Rhodophyta species (Gelidiella acerosa and Titanophora pulchra) with enzyme-treated rabbit and horse erythrocytes. The hemagglutinins of some active species were examined for sugar-binding specificity, pH, temperature stability, and divalent cation independency using ammonium sulfate precipitates prepared from their extracts. In a hemagglutination–inhibition test with various monosaccharides and glycoproteins, none of the hemagglutinins had affinity for monosaccharides. The activity of the hemagglutinins was inhibited by some glycoproteins tested. The inhibition profiles with glycoproteins were different depending on hemagglutinin species, suggesting the presence of lectins specific for complex N-glycans, high mannose N-glycans or O-glycans. On the other hand, the activities of almost all algal hemagglutinins were stable over a wide range of pH and temperature, and independent of the presence of divalent cations, except Gelidiopsis scoparia hemagglutinin, its activity was dependent on the presence of divalent cations. These results suggest that Vietnamese marine macroalgae may be good sources of useful lectins for many biological applications.  相似文献   

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Aqueous protein extracts from 30 Brazilian marine algae were examined for haemagglutinating activity using native and enzyme-treated rabbit, chicken, sheep and human erythrocytes. Most extracts agglutinated at least one of the blood cells used. Sheep and rabbit erythrocytes were more suitable for detection of the agglutinating activity. The minimum protein concentration necessary to produce positive agglutination was usually lower with enzyme-treated erythrocytes than native ones. The five algal protein extracts showing the greatest haemagglutination titre were tested for sugar-binding specificity. Only the activity present in the green alga Cauler pacupressoides was inhibited by simple sugars and not by the glycoproteins tested. The activity of the other four extracts was inhibited by at least one of the glycoproteins utilised. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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