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991.
Novel ecosystems: theoretical and management aspects of the new ecological world order 总被引:9,自引:1,他引:8
Richard J. Hobbs Salvatore Arico James Aronson Jill S. Baron Peter Bridgewater Viki A. Cramer Paul R. Epstein John J. Ewel Carlos A. Klink Ariel E. Lugo David Norton Dennis Ojima David M. Richardson Eric W. Sanderson Fernando Valladares Montserrat Vilà Regino Zamora Martin Zobel 《Global Ecology and Biogeography》2006,15(1):1-7
We explore the issues relevant to those types of ecosystems containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and inadvertent introduction of species from other regions. Novel ecosystems (also termed 'emerging ecosystems') result when species occur in combinations and relative abundances that have not occurred previously within a given biome. Key characteristics are novelty, in the form of new species combinations and the potential for changes in ecosystem functioning, and human agency, in that these ecosystems are the result of deliberate or inadvertent human action. As more of the Earth becomes transformed by human actions, novel ecosystems increase in importance, but are relatively little studied. Either the degradation or invasion of native or 'wild' ecosystems or the abandonment of intensively managed systems can result in the formation of these novel systems. Important considerations are whether these new systems are persistent and what values they may have. It is likely that it may be very difficult or costly to return such systems to their previous state, and hence consideration needs to be given to developing appropriate management goals and approaches. 相似文献
992.
Kamphuis S Hrafnkelsdóttir K Klein MR de Jager W Haverkamp MH van Bilsen JH Albani S Kuis W Wauben MH Prakken BJ 《Arthritis research & therapy》2006,8(6):R178
Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disease characterized by chronic joint inflammation. Knowing which antigens drive the autoreactive T-cell response in JIA is crucial for the understanding of disease pathogenesis and additionally may provide targets for antigen-specific immune therapy. In this study, we tested 9 self-peptides derived from joint-related autoantigens for T-cell recognition (T-cell proliferative responses and cytokine production) in 36 JIA patients and 15 healthy controls. Positive T-cell proliferative responses (stimulation index > or =2) to one or more peptides were detected in peripheral blood mononuclear cells (PBMC) of 69% of JIA patients irrespective of major histocompatibility complex (MHC) genotype. The peptides derived from aggrecan, fibrillin, and matrix metalloproteinase (MMP)-3 yielded the highest frequency of T-cell proliferative responses in JIA patients. In both the oligoarticular and polyarticular subtypes of JIA, the aggrecan peptide induced T-cell proliferative responses that were inversely related with disease duration. The fibrillin peptide, to our knowledge, is the first identified autoantigen that is primarily recognized in polyarticular JIA patients. Finally, the epitope derived from MMP-3 elicited immune responses in both subtypes of JIA and in healthy controls. Cytokine production in short-term peptide-specific T-cell lines revealed production of interferon-gamma (aggrecan/MMP-3) and interleukin (IL)-17 (aggrecan) and inhibition of IL-10 production (aggrecan). Here, we have identified a triplet of self-epitopes, each with distinct patterns of T-cell recognition in JIA patients. Additional experiments need to be performed to explore their qualities and role in disease pathogenesis in further detail. 相似文献
993.
Capaldo A Gay F De Falco M Virgilio F Valiante S Laforgia V Varano L 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2006,143(1):86-93
The aims of this study were to propose a bioindicator organism, the newt Triturus carnifex, for the assessment of toxicological impact of thiophanate methyl in the Campania region (Italy) and the possible adverse activity on the adrenal gland. In the acute toxicity study, experimental groups of T. carnifex were exposed to 2.40, 4.80, 9.60 and 19.20 microg/L tap water of thiophanate methyl for 2 days; the LD50 was found to be 9.60 microg/L. To evaluate the effects on the adrenal gland, newts were exposed to a dose of 25% of the LD50 2 days for 8 days. The ultrastructural features of the tissues as well as the serum levels of aldosterone, corticosterone, norepinephrine (NE) and epinephrine (E) were evaluated. The number of secretory vesicles in the chromaffin cells appeared significantly decreased, whereas NE and E serum levels appeared strongly increased. Moreover, corticosterone and aldosterone serum levels appeared significantly reduced. The results suggest that: 1) T. carnifex has the features of an ideal bioindicator, due to its high sensitivity to thiophanate methyl, 2) thiophanate methyl acts as endocrine disruptor, affecting the adrenal gland at very low doses, 3) thiophanate methyl may be toxic for nontarget organisms, such as newts. 相似文献
994.
Di Francesco A Donati M Mattioli L Naldi M Salvatore D Poglayen G Cevenini R Baldelli R 《The new microbiologica》2006,29(4):303-305
We tested 731 sera from apparently healthy light horses against Chlamydophila pneumoniae, by a microimmuno-fluorescence (MIF) test. To verify cross-reactions with other species of chlamvdiae, all sera with an antibody titre > or = 32 to C. pneumoniae were tested against both C. psittaci and C. abortus. Antibodies to C. pneumoniae were detected in 194 out of 731 (26.5%) samples tested, with antibody titres ranging from 32 to 1024. No antibody titre > or = 32 was detected in sera to C. abortus. Only few sera with a high antibody titre to C. pneumoniae reacted weakly with C. psittaci at the dilution of 1:32. 相似文献
995.
Colicchio R Pagliarulo C Lamberti F Vigliotta G Bruni CB Alifano P Salvatore P 《DNA Repair》2006,5(12):1428-1438
Several invasive serogroup B meningococcal strains phylogenetically related to the lineage III (ET-24) exhibited a mutator phenotype as shown by mutagenicity assay using rifampicin-resistance as a selection marker. Hypermutation was associated to the presence of defective mutL alleles that were genetically characterized. Interestingly, the mutator phenotype was suppressed when a non-functional recB(ET-37) allele, derived from ET-37 meningococcal strains, replaced the functional recB allele in a lineage III strain. In contrast, the same gene replacement did not affect mutation frequencies in a mismatch repair-proficient strain. These results suggested that in MutL-deficient strains spontaneous mutations mostly arise from post-replicative DNA synthesis associated to the activity of the RecBCD recombination pathway. 相似文献
996.
De Rosa S Seizova K Kamenarska Z Petrova A Iodice C Stefanov K Popov S 《Zeitschrift für Naturforschung. C, Journal of biosciences》2006,61(1-2):129-134
The sterol and fatty acid composition of three Adriatic Sea sponges (Geodia cydonium and two unidentified Tedania sp.), collected at the same time and same place, was established. Twenty-four sterols and forty fatty acids were identified. The identical ecological conditions, including the diet, allowed us to apply the results obtained for taxonomical conclusions, based on the biodiversity of the investigated sponges. On the basis of the sterol composition they can be separated into two groups: Tedania and Geodia sponges. The sterol and fatty acid composition indicates that the two investigated Tedania samples might be different species or subspecies. 相似文献
997.
De-Simone SG de Salles CM Batista e Silva CM Hassón-Voloch A 《Zeitschrift für Naturforschung. C, Journal of biosciences》2006,61(11-12):884-888
A soluble fructose-1,6-bisphosphate aldolase enzyme has been purified 50.2-fold (2.36%) at the homogeneity from the electric organ of Electrophorus electricus by one step of DEAE-52 anion exchange chromatography followed by Superose-12 gel filtration-FPLC. Like other aldolase enzymes the E. electricus protein is a dimer with two identical subunits of 45 kDa. The N-terminal (20 residues) revealed a high homology with S. aurata (75%, goldfish), R. ratus and M. musculus (mouse, 80%) enzymes. 相似文献
998.
Burgey CS Stump CA Nguyen DN Deng JZ Quigley AG Norton BR Bell IM Mosser SD Salvatore CA Rutledge RZ Kane SA Koblan KS Vacca JP Graham SL Williams TM 《Bioorganic & medicinal chemistry letters》2006,16(19):5052-5056
In our continuing effort to identify CGRP receptor antagonists for the acute treatment of migraine, we have undertaken a study to evaluate alternative 4-substituted piperidines to the lead dihydroquinazolinone 1. In this regard, we have identified the piperidinyl-azabenzimidazolone and phenylimidazolinone structures which, when incorporated into the benzodiazepine core, afford potent CGRP receptor antagonists (e.g., 18 and 29). These studies produced a potent analog (18) which overcomes the instability issues associated with the lead structure 1. A general pharmacophore for the 4-substituted piperidine component of these CGRP receptor antagonists is also presented. 相似文献
999.
Cappelli A Matarrese M Moresco RM Valenti S Anzini M Vomero S Turolla EA Belloli S Simonelli P Filannino MA Lecchi M Fazio F 《Bioorganic & medicinal chemistry》2006,14(12):4055-4066
The previous exploration of the structure-affinity relationships concerning 4-phenyl-2-quinolinecarboxamide peripheral benzodiazepine receptor (PBR) ligands 6 showed as an interesting result the importance of the presence of a chlorine atom in the methylene carbon at position 3 of the quinoline nucleus. The subnanomolar PBR affinity shown by N-benzyl-3-chloromethyl-N-methyl-4-phenyl-2-quinolinecarboxamide (6b) suggested its chlorine atom to be replaced with other halogens in order to optimize the interaction of the quinolinecarboxamide derivatives with PBR and to develop suitable candidates for positron emission tomography (PET) or single photon emission computed tomography (SPECT) studies. The binding studies led to the discovery of fluoromethyl derivative 6a, which showed an IC50 value of 0.11 nM and is, therefore, one of the most potent PBR ligands so far described. Fluoromethyl derivative 6a has been labeled with 11C (t1/2=20.4 min, beta+=99.8%) starting from the corresponding des-methyl precursor (14) using [11C]CH3I in the presence of tetrabutylammonium hydroxide in DMF with a 35-40% radiochemical yield (corrected for decay) and 1.5 Ci/micromol of specific radioactivity. Ex vivo rat biodistribution and inhibition (following intravenous pre-administration of PK11195) studies showed that [11C]6a rapidly and specifically accumulated in PBR-rich tissues such as heart, lung, kidney, spleen, and adrenal, and at a lower level in other peripheral organs and in the brain. The images obtained in mouse with small animal YAP-(S)PET essentially confirmed the result of the ex vivo biodistribution experiments. The biological data suggest that [11C]6a is a promising radioligand for peripheral benzodiazepine receptor PET imaging in vivo. 相似文献
1000.
Forest Management and Plant Species Diversity in Chestnut Stands of Three Mediterranean Areas 总被引:1,自引:0,他引:1
Hélène Gondard François Romane Ignacio Santa Regina Salvatore Leonardi 《Biodiversity and Conservation》2006,15(4):1129-1142
Over many centuries, chestnut fruits had an important role as food, while chestnut wood was used for local purposes. Today
sweet chestnut stands are very common around the western Mediterranean Basin, and it is necessary to analyze the dynamic of
plant species diversity in different chestnut stand types (groves and coppices) to guide management strategies that will allow
the conservation of biodiversity. Our objective was to analyze consequences on plant species diversity of various management
strategies in chestnut stands of three Mediterranean areas, Salamanca (Spain), the Cévennes (France), and Etna volcano (Italy).
We found that plant species diversity is different according to management types; it is higher in groves than in coppice stands.
We also demonstrated that Castanea sativa cultivated groves were characterized by small heliophillous therophytes. C. sativa abandoned groves, mixed C. sativa–Quercus pyrenaica coppice stands, Q. pyrenaica coppice stands, and young C. sativa coppice stands were characterized by hemicryptophytes with anemochorous dispersal mode and chamaephytes. Medium and old C. sativa coppice stands (that differ by the shoot age) were characterized by phanerophytes with zoochorous dispersal mode. Human perturbations
maintain a quite high level of species diversity. In contrast, the abandonment of chestnut stands leads to homogeneous vegetation
with decreasing diversity. One solution could be to maintain a landscape mosaic constituted of diverse chestnut stands modified
by human activities (groves, cultivated or abandoned, and coppice stands). This could enhance regional plant diversity. 相似文献