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11.
Depending on their faunal content islands can function as important ‘vehicles’ for conservation. In this study, we examine data on 440 butterfly species over 564 European islands in 10 island groups. To determine the status of the butterfly fauna, we have adopted two approaches, island-focused and species-focused, examined using principal components analysis and regression modelling. In the former, we relate species richness, rarity and endemicity to island geography (area, elevation, isolation and location in latitude and longitude); in the latter, species occurrence on islands is examined in relation to distribution, range, range boundaries, and altitudinal limits on the continent as well as species’ ecology (number of host plants) and morphology (wing expanse). Species on islands are also assessed for their status on the continental mainland, their distributional dynamics (extinctions, distribution changes) and conservation status (Red Data Book, European Habitat Directive, Species of European Conservation Concern and Bern Convention listing. Unexpectedly, we find that a large fraction of the European butterfly species is found on the islands (63.4%; 59% on small islands) comprising some 6.2% of the land area of Europe. Although species occurring on the islands tend, on the whole, to have lower conservation status and are not declining over Europe, 45 species are endemics restricted to the islands. Species richness shows only a weak locational pattern and is related as expected to isolation from the continental source and island area; but, both rarity and endemicity have distinctive geographical bias to southern Europe, on islands now under increasing pressure from climate change and increasingly intensive human exploitation. The vulnerability of species on islands is emphasised in the relationship of island occurrence (% occurrence and presence/absence of species on any island) with continental distributions. A large proportion of the variation (84%) is accounted by continental distribution, the southern range limit and lower altitudinal limit. Most species (69%) occur on very few islands (<5%). In view of ongoing species dynamics on islands, migrations and extinctions of species, island repositories of species depend in large part on conservation of butterflies at continental sources. The unique faunas and rare species on islands also depend on appropriate concern being given to the island faunas. Conservation of European islands is thus a two-way process, sustaining sources and conserving island refuges. Residuals from the regressions (islands with more or fewer species, rare and endemic species; species occurring more or less frequently than expected on islands) provide warning signals of regions and islands deserving immediate attention.  相似文献   
12.
13.
Hormones in milk     
Otakar Koldovsky 《Life sciences》1980,26(22):1833-1836
Hormones are present in milk of man and other mammals. Their concentration is influenced by various factors. Studies in rodents show that some hormones with large molecules retain physiological activity when administered perorally to suckling mammals.  相似文献   
14.
The 1030-residue polypeptide chain of the NAD-specific glutamate dehydrogenase of Neurospora crassa was fragmented by treatment with cyanogen bromide. The isolation and sequences of 18 fragments ranging in size from 4 to 51 residues are described. Some of these peptides proved to be cleavage products resulting from hydrolysis at acid-sensitive aspartyl-prolyl bonds. Some overlaps could be deduced on the basis of known sequences of peptides obtained by tryptic hydrolysis.  相似文献   
15.
Suckling rat liver N-acetyl-β-glucosaminidase (hexosaminidase) activity undergoes considerable fluctuation during the first two weeks of life. As two major forms of hexosaminidase (A, heat-labile, and B, heat-stable) are known to exist in both human and adult rat liver, we choose to examine the effect of the maturative hormones, thyroxine and cortisone, upon these isozymes during the suckling period. Between days 7 and 15, the observed developmental change is attributable solely to an increase in the ‘A-like’ (heat-labile) form of the enzyme; an enhanced response is seen in thyroxine-injected 11–15-day old animals. The response may be considered ‘age-independent’, as adult animals react in the same manner. In contrast, cortisone-injected sucklings show a decrease in both A and B isozymes, while in adults no changes in total activity or isozyme distribution are evoked. The ratio of hexosaminidase A to hexosaminidase B in suckling rat liver appears to shift in favor of the labile (A) isozyme early in development.  相似文献   
16.
The phenolic compound composition, antioxidant activity and impact on cell viability of edible flower extracts of Allium schoenoprasum; Bellis perennis; Cichorium intybus; Rumex acetosa; Salvia pratensis; Sambucus nigra; Taraxacum officinale; Tragopogon pratensis; Trifolium repens and Viola arvensis was examined for the first time. Total phenolic content of the flowers of these plants fell between 11.72 and 42.74 mg of tannin equivalents/kg of dry matter. Antioxidant activity ranged from 35.56 to 71.62 g of ascorbic acid equivalents/kg of dry matter. Using the Human Hepatocellular Carcinoma cell-line (HepG2) and the Human Immortalized Non-tumorigenic Keratinocyte cell line (HaCaT), we assessed cell viability following a 3 day incubation period in media containing 25, 50, 75 and 100 μg/ml of total phenolic compounds using a colorimetric MTT assay. These three properties could make the herbs useful in treatment of various diseases like cancer. The tested extracts had significant effects on cell viability, but the effects were dependent not only on the phenolic compound concentration and the edible flowers species, but also on the phenolic compound and antioxidant profiles. In addition, responses differed between cell lines.  相似文献   
17.
Carbon and oxygen stable isotope records were compared for Jurassic/Cretaceous (J/K) boundary sections located in the Tethyan Realm (Brodno, Western Slovakia, and Puerto Escaño, Southern Spain; bulk limestones), and the Boreal Realm (Nordvik Peninsula, Northern Siberia, belemnites). Since a detailed biostratigraphic correlation of these Tethyan and Boreal sections is impossible due to different faunal assemblages, correlation of the isotope records was based on paleomagnetic data. This novel approach can improve our understanding of the synchroneity of individual isotope excursions in sections where detailed biostratigraphic correlation is impossible. No significant excursions in either the carbon or oxygen isotope records to be used for future Boreal/Tethyan correlations were found around the J/K boundary (the upper Tithonian and lower Berriasian; magnetozones M20n to M18n) in the studied sections. At the Nordvik section, where a much longer section (middle Oxfordian–basal Boreal Berriasian) was documented, the transition from the middle Oxfordian to the Kimmeridgian and further to the Volgian is characterized by a decrease in belemnite δ18O values (from δ18O values up to + 1.6‰ vs. V-PDB in the Oxfordian to values between + 0.3 and ? 0.8‰ in the late Volgian and earliest Boreal Berriasian). This trend, which has previously been reported from the Russian Platform and Tethyan Realm sections, corresponds either to gradual warming or a decrease in seawater δ18O. Supposing that the oxygen isotope compositions of seawater in the Arctic/Boreal and Tethyan Realms were similar, then the differences between oxygen isotope datasets for these records indicate differences in temperature. The Boreal/Tethyan temperature difference of 7–9 °C in the middle and late Oxfordian decreases towards the J/K boundary, indicating a significant decrease in latitudinal climatic gradients during the Late Jurassic. Two positive carbon isotope excursions recorded for the middle Oxfordian and upper Kimmeridgian in the Nordvik section can be correlated with a similar excursion described earlier for the Russian Platform. Minor influence of biofractionation at the carbon isotopes, and the influence of migration of belemnites to deeper, slightly cooler water at the oxygen isotopes, cannot be excluded for the obtained belemnite data.  相似文献   
18.
At present, Cape gooseberry (Physalis peruviana) fruit is one of the less used raw materials of plant origin, which can be used for human nutrition. This fruit, as well as alimentary products made of it, were used by healers in folk medicine in the distant past. The aim of this study was to monitor and evaluate the antioxidant capacity of fresh fruit of three Cape gooseberry cultivars ‘Giant’, ‘Golden berry’ and ‘Inka’. Antioxidant capacity was also tested, on the basis of the scavenging effect of reactive oxygen species (ROS) and lipid peroxidation of methanolic extracts made of fresh fruit. These results were further extended and supplemented with determinates of the vitamin C and total phenolic contents. These analyses were made for three consecutive years. The highest values of antioxidant capacity were observed in the ‘Inka’ cultivar (9.31 grams of ascorbic acid equivalents kg−1 of fresh mass). In this cultivar, the obtained results were corroborated also in ROS and the contents of vitamin C and total phenolics. Due to a high antioxidant capacity of this fruit species, the results presented should increase its popularity above all as a promising raw material, which can be used for human nutrition.  相似文献   
19.
Soboren, Josephine (University of California, Los Angeles), and Joseph F. Nyc. Amino acid interactions in Neurospora crassa. J. Bacteriol. 82:20-25. 1961.-A systematic study of the effects of the naturally occurring amino acids on the growth of a wild-type strain of Neurospora crassa focused attention upon l-tryptophan, which exhibits a strong growth inhibitory effect. Further investigation disclosed that other tryptophan metabolites, anthranilic acid, indole, kynurenine, and 3-hydroxykynurenine also inhibit growth. The proposed antimetabolic role of these aromatic compounds explains the poor growth response of certain tryptophan-requiring strains of N. crassa to tryptophan supplements. The growth of normal and mutant strains of N. crassa on media supplemented with tryptophan is influenced by the presence of other amino acids.  相似文献   
20.
In the recent past, we demonstrated that a great deal is going on in the salivary glands of Drosophila in the interval after they release their glycoprotein‐rich secretory glue during pupariation. The early‐to‐mid prepupal salivary glands undergo extensive endocytosis with widespread vacuolation of the cytoplasm followed by massive apocrine secretion. Here, we describe additional novel properties of these endosomes. The use of vital pH‐sensitive probes provided confirmatory evidence that these endosomes have acidic contents and that there are two types of endocytosis seen in the prepupal glands. The salivary glands simultaneously generate mildly acidic, small, basally‐derived endosomes and strongly acidic, large and apical endosomes. Staining of the large vacuoles with vital acidic probes is possible only after there is ambipolar fusion of both basal and apical endosomes, since only basally‐derived endosomes can bring fluorescent probes into the vesicular system. We obtained multiple lines of evidence that the small basally‐derived endosomes are chiefly involved in the uptake of dietary Fe3+ iron. The fusion of basal endosomes with the larger and strongly acidic apical endosomes appears to facilitate optimal conditions for ferrireductase activity inside the vacuoles to release metabolic Fe2+ iron. While iron was not detectable directly due to limited staining sensitivity, we found increasing fluorescence of the glutathione‐sensitive probe CellTracker Blue CMAC in large vacuoles, which appeared to depend on the amount of iron released by ferrireductase. Moreover, heterologous fluorescently‐labeled mammalian iron‐bound transferrin is actively taken up, providing direct evidence for active iron uptake by basal endocytosis. In addition, we serendipitously found that small (basal) endosomes were uniquely recognized by PNA lectin, whereas large (apical) vacuoles bound DBA lectin.  相似文献   
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