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111.
Abstract Among eight species of Polydrusus weevils which belong to subgenus Scythodrusus, at least two possess parthenogenetic forms: P. (S.) inustus and P. (S.) pilifer. Both of these species consist of dioecious populations in the Caspian area and of parthenogenetic populations in Eastern Europe (P. (S.) inustus), the Caucasus region (both species) and Middle Asia (P. (S.) pilifer). The origin of parthenogenesis in this subgenus is unresolved; however some data suggest that the parthenogenetic forms are of hybrid ancestry. The genetic distinctness of parthenogenetic Scythodrusus was assessed on the basis of COII, ITS2, EF1‐α and Wolbachiawsp, 16S ribosomal DNA, ftsZ and hcpA sequence comparisons. Both taxa turned out to be monophyletic for all markers, which is an evidence against hybridization of their dioecious ancestors. On the other hand, a high frequency of heterozygous P. (S.) inustus females suggests an origin resulting from hybridization between genetically distinct dioecious representatives of this species. Very similar strains of Wolbachia supergroup A were found in both species, indicating that they have been either inherited from a common ancestor or were transmitted between parthenogenetic Scythodrusus weevils and probably spread randomly across their ranges.  相似文献   
112.
ABSTRACT: BACKGROUND: In Europe, only a limited number of cross-cultural comparative field studies or meta-analyses have been focused on the dynamics through which folk plant knowledge changes over space and time, while a few studies have contributed to the understanding of how plant uses change among newcomers. Nevertheless, ethnic minority groups and/or linguistic "isles" in Southern and Eastern Europe may provide wonderful arenas for understanding the various factors that influence changes in plant uses. METHODS: A field ethnobotanical study was carried out in Mundimitar (Montemitro in Italian), a village of approx. 450 inhabitants, located in the Molise region of South-Eastern Italy. Mundimitar is a South-Slavic community, composed of the descendants of people who migrated to the area during the first half of the 14th century, probably from the lower Neretva valley (Dalmatia and Herzegovina regions). Eighteen key informants (average age: 63.7) were selected using the snowball sampling technique and participated in in-depth interviews regarding their Traditional Knowledge (TK) of the local flora. RESULTS: Although TK on wild plants is eroded in Montemitro among the youngest generations, fiftyseven taxa (including two cultivated species, which were included due to their unusual uses) were quoted by the study participants. Half of the taxa have correspondence in the Croatian and Herzegovinian folk botanical nomenclature, and the other half with South-Italian folk plant names. A remarkable link to the wild vegetable uses recorded in Dalmatia is evident. A comparison of the collected data with the previous ethnobotanical data of the Molise region and of the entire Italian Peninsula pointed out a few uses that have not been recorded in Italy thus far: the culinary use of boiled black bryony (Tamus communis) shoots in sauces and also on pasta; the use of squirting cucumber (Ecballium elaterium) juice for treating malaria in humans; the aerial parts of the elderberry tree (Sambucus nigra) for treating erysipelas in pigs; the aerial parts of pellitory (Parietaria judaica) in decoctions for treating haemorrhoids. CONCLUSIONS: The fact that half of the most salient species documented in our case study - widely available both in Molise and in Dalmatia and Herzegovina - retain a Slavic name could indicate that they may have also been used in Dalmatia and Herzegovina before the migration took place. However, given the occurrence of several South-Italian plant names and uses, also a remarkable acculturation process affected the Slavic community of Montemitro during these last centuries. Future directions of research should try to simultaneously compare current ethnobotanical knowledge of both migrated communities and their counterparts in the areas of origin.  相似文献   
113.
Thiocyanates (SCN-) are ubiquitous in nature. There are indispensable part of host defense system that act as a substrate for lactoperoxidase (LPO). In our study we present initial data on SCN- concentration in saliva of CF patients in comparison to healthy non-smokers and healthy smokers. 5 ml of saliva was collected from each subject to a sterile tube and thiocyanate concentration was measured in each sample. The results of the measurements are presented on Fig. 1. Mean concentration of SCN- in saliva of CF patients was 0.031 +/- 0.0052 g/l, in healthy non-smokers 0.039 +/- 0.0048 g/l and in healthy smokers 0.048 +/- 0.0161 g/l. The differences between each group were statistically significant. Studies on larger group of patients and probably on different material (BALF or induced sputum) should present interesting data complementing the in vitro studies.  相似文献   
114.
A literature survey was performed of human cathepsin D gene, cathepsin D biosynthesis, posttranslatory modifications, transport within the cell, substrate specificity and catalytic effect. Methods used to determine the activity and level of this proteinase as well as its role in the biochemistry and pathobiochemistry of cells, tissues and organs were considered.  相似文献   
115.
Phytol, a C20 alcohol esterifying the C-17(3) propionate, and Mg2+ ion chelated in the central cavity, are conservative structural constituents of chlorophylls. To evaluate their intramolecular structural effects we prepared a series of metal- and phytyl-free derivatives of bacteriochlorophyll a and applied them as model chlorophylls. A detailed spectroscopic study on the model pigments reveals meaningful differences in the spectral characteristics of the phytylated and non-phytylated pigments. Their analysis in terms of solvatochromism and axial coordination shows how the central Mg and phytyl residue shape the properties of the pigment. Surprisingly, the presence/absence of the central Mg has no effect on the solvatochromism of (bacterio)chlorophyll pi-electron system and the hydrophobicity of phytyl does not interfere with the first solvation shell of the chromophore. However, both residues significantly influence the conformation of the pigment macrocycle and the removal of either residue increases the macrocycle flexibility. The chelation of Mg has a flattening effect on the macrocycle whereas bulky phytyl residue seems to control the conformation of the chromophore via steric interactions with ring V and its substituents. The analysis of spectroscopic properties of bacteriochlorophyllide (free acid) shows that esterification of the C-17(3) propionate is necessary in chlorophylls because the carboxyl group may act as a strong chelator of the central Mg. These observations imply that the truncated chlorophylls used in theoretical studies are not adequate as models of native chromophores, especially when fine effects are to be modeled.  相似文献   
116.
It is well documented that glycan synthesis is altered in some pathological processes, including cancer. The most frequently observed alterations during tumourigenesis are extensive expression of beta1,6-branched complex type N-glycans, the presence of poly-N-acetyllactosamine structures, and high sialylation of cell surface glycoproteins. This study investigated two integrins, alpha3beta1 and alpha(v)beta3, whose expression is closely related to cancer progression. Their oligosaccharide structures in two metastatic melanoma cell lines (WM9, WM239) were analysed with the use of matrix-assisted laser desorption ionisation mass spectrometry. Both examined integrins possessed heavily sialylated and fucosylated glycans, with beta1,6-branches and short polylactosamine chains. In WM9 cells, alpha3beta1 integrin was more variously glycosylated than alpha(v)beta3; in WM239 cells the situation was the reverse. Functional studies (wound healing and ELISA integrin binding assays) revealed that the N-oligosaccharide component of the tested integrins influenced melanoma cell migration on vitronectin and alpha3beta1 integrin binding to laminin-5. Additionally, more variously glycosylated integrins exerted a stronger influence on these parameters. To the best of our knowledge, this is the first report concerning structural characterisation of alpha(v)beta3 integrin glycans in melanoma or in any cancer cells.  相似文献   
117.
Defense responses to inoculation with Fusarium oxysporum SCHLECHT f. sp. lupini were studied in embryo axes of Lupinus luteus L. cv. Polo cultured on a medium with sucrose (60 mM) or without it. Exogenous sucrose caused a marked endogenous increase in concentrations of sucrose, glucose and fructose in embryo axes. In axes cultured with sucrose, high performance liquid chromatography (HPLC) revealed generally higher levels of isoflavone glycosides (particularly until 48 h of culture) and free aglycones (genistein, wighteone, luteone). Inoculation resulted in a considerable decline in soluble carbohydrates between 24 and 72 h of culture. Simultaneously, the infection stimulated an increase in the level of free isoflavone aglycones in inoculated embryo axes, as compared to non-inoculated ones. Concentrations of free aglycones (i.e. genistein, wighteone and luteone) after infection were particularly high in inoculated embryo axes fed with sucrose. Genistein was a better inhibitor to F. oxysporum growth than genistein 7-O-glucoside tested. Exogenous sucrose also stimulated the activity of phenylalanine ammonialyase (PAL, EC 4.3.1.5)--an important enzyme initiating phenylpropanoid metabolism. After infection of tissues, a strong increase was observed in the activity of PAL and beta-glucosidase (EC 3.2.1.21)--an enzyme hydrolyzing isoflavone glycosides. Furthermore, the growth of inoculated embryo axes cultured with sucrose was less inhibited as a result of infection than inoculated axes cultured under carbohydrate deficiency conditions. Additionally, it had been reported previously that disease symptoms of embryo axes growing in the presence of sucrose were less intensive [30]. These results suggest that soluble sugars are involved in the mechanism of resistance, as they can stimulate phenylpropanoid metabolism and contribute to the increase in concentration of isoflavonoids, which are important elements of the defense system of legumes.  相似文献   
118.
The arbuscular mycorrhizal status of two plant species, Biscutella laevigata L. and Plantago lanceolata L., was investigated on calamine spoil mounds in Boles^aw (southern Poland). Although B. laevigata is a member of the Brassicaceae, a family generally accepted as non-mycorrhizal, this species formed AM symbioses on both heavy metal-contaminated and non-contaminated sites. Besides vesicles and coils, arbuscules were also observed, especially in roots collected prior to seed maturity. Relative mycorrhizal root length and relative arbuscular richness were usually much higher in P. lanceolata than in B. laevigata but not absolute arbuscule richness. Roots of P. lanceolata showed higher colonisation than B. laevigata. Although roots were collected from plants in close proximity, no correlation in mycorrhizal parameters was found between the two species.  相似文献   
119.
Ł aska  Grażyna 《Plant Ecology》2001,157(1):77-99
Disturbances are common phenomena that occurs in nature and significantly affects the dynamics of vegetation and plant populations. This paper shows that despite considerable progress in the theory of disturbances, for different authors the notion of disturbance has different meanings. The differences follow from an alternative understanding of the term, assumption of the holistic or reductionistic concept of the study or different approaches to equilibrium and non-equilibrium in nature. Different theoretical and methodological assumptions taken when analysing vegetation changes under the effect of disturbances allow relative arbitrariness in the interpretation of results. However, not all biotic interactions and ecological processes taking place in plant communities can be identified as disturbances. The effects of disturbances should be described on the basis of an objective assessment of what is normal for the functioning and stabilisation of a community as well as what disturbs and disrupts this equilibrium. Moreover, assuming the equivalent treatment of ecological systems, the interaction of the disturbing factors should be related to a specific level of life organisation (an individual, population or community), which would permit unambiguous discernment of the disturbance effects and finally generalise its effects on different levels of the hierarchical structure of vegetation.  相似文献   
120.
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