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1.
Chlorophyll-fluorescence parameters of three mosses, Rhytidiadelphusloreus (Hedw.) Warnst.,Anomodon viticulosus (Hedw.) Hook &Tayl. and Grimmia pulvinata (Hedw.) Sm. were measured duringdrying, and following remoistening after a period of desiccation.Most changed little with drying until the full-turgor pointwas approached, when rapid changes accompanied loss of cellwater. In R. loreus all parameters decreased together down toa water content of about 30% d.wt (RWC approx. 0.15). At lowwater contents (5–16% d.wt; RWC approx. 0.02–0.08)saturating pulses tended to suppress rather than stimulate fluorescence.In A. viticulosus Fv/Fm, qPand  相似文献   
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Glial cell line-derived neurotrophic factor (GDNF) promotes development and differentiation of dopaminergic neurons, thus it has an important role in dopamine-related neuropsychiatric disorders. Since the role of dopamine system in smoking is well established, we hypothesized that GDNF gene variants may affect smoking behaviour. Self-reported data on smoking behaviour (never smoked, quit, occasional, or regular smokers) and level of nicotine addiction (Hooked on Nicotine Checklist and Fagerstrom Nicotine Addiction Scale), anxiety, as well as buccal samples were obtained from 930 Hungarian young adults (18–35 years). Genetic analysis involved eight GDNF single-nucleotide polymorphisms (SNP) (rs1981844, rs3812047, rs3096140, rs2973041, rs2910702, rs1549250, rs2973050 and rs11111). Allele-wise association analyses of the eight GDNF SNPs provided a significant association between smoking behaviour and rs3096140 (P = 0.0039). The minor allele (C) was more frequent in those groups who smoked in some form (quit, occasional or regular smokers) as compared to those who never smoked (P = 0.0046). This result remained significant after Bonferroni correction for multiple testing. In the ever smoking group, no significant differences were found in the level of nicotine addiction by the alleles of these polymorphisms. Also, no significant interaction of rs3096140 and smoking categories were observed on anxiety mean scores. Although previous data demonstrated an association between GDNF rs2910704 and severity of methamphetamine use to the best of our knowledge, this is the first study on the role of GDNF genetic variations in smoking behaviour. Our results suggest that GDNF rs3096140 might be involved in the genetic background of smoking, independent of anxiety characteristics.  相似文献   
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Feeding innovations and parasitism in birds   总被引:2,自引:0,他引:2  
The rate of behavioural innovation, such as opportunistic feeding innovation, may facilitate adaptation to novel environments. Because parasites may affect how their hosts adopt novel means of resource acquisition, or because opportunistic behaviours may involve the risk of being exposed to a large parasite fauna, we hypothesize an evolutionary link between the rate of feeding innovations and parasitism. We investigated the phylogenetic relationship between relative frequency of feeding innovations (adjusted for research effort and population size) and relative size of immune defense organs (as a relative measure of parasite-mediated selection) and the prevalence of blood parasites in birds. Using generalized least squares models, we found that species with relatively large bursa of Fabricius, thymus, and spleen had higher rates of feeding innovations than species with small immune defense organs. Similarly, there was a positive interspecific association between feeding innovation and haematozoa prevalence. These relationships were not confounded by migration, relative brain size, geographical distribution, and male plumage brightness. Analyses of causality relying on evolutionary modelling of discrete variables and path analysis suggest that increasing rate of feeding innovation may place species under intense selection due to parasitism. Therefore, behavioural adaptation by feeding innovation seems to have consequences for the coevolutionary arm race between parasites and hosts.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 441–455.  相似文献   
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1. Adult caddisflies (Trichoptera) and mayflies (Ephemeroptera) were light-trapped on summer evenings along the Detroit River and Lake St. Clair, near Windsor, Ontario, Canada. Light traps were located at the shore and at increasing distances inland up to 5 km, and were operated simultaneously for 2 h following sunset. Catches of five species of caddisflies of the family Hydropsychidae ( Cheumatopsyche campyla , Cheumatopsyche speciosa , Hydropsyche hageni , Hydropsyche phalerata , Macrostemum zebratum ) and the mayfly Hexagenia (Ephemeridae) were used to examine inland distribution.
2. Inland dispersal was limited: catches of caddisflies declined at a greater than exponential rate with increasing distance from shore. Mean dispersal distance from the shoreline ranged from 650 to 1845 m. Smaller caddisfly species dispersed shorter distances than larger caddisflies and Hexagenia .
3. Inland distribution of adult caddisflies exhibited considerable interspecific variation: distribution was inconsistent among trials for Hexagenia , possibly owing to timing of collections in relation to periods of peak emergence.
4. Sex ratios of caddisflies were female biased at most sites. No consistent bias was observed for Hexagenia . Different inland distribution patterns were observed for males and females. The differences appeared to reflect species-specific reproductive strategies.  相似文献   
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Insect‐induced galls on plants comprise species‐rich but self‐contained communities of herbivores and natural enemies. In the present study, we focus on galls induced by cynipid gall wasps on oaks, and on the least‐known trophic level that these galls contain: inquilines. These insects, also cynipids, feed on gall tissue and are an abundant but taxonomically poorly understood part of an otherwise well‐studied system. We used DNA sequence data to examine spatial patterns in the genetic diversity of Synergus umbraculus Olivier 1791 (Hymenoptera: Cynipidae: Synergini), a widespread species attacking many host galls across the Western Palaearctic. Analysis of 239 cytochrome b sequences revealed eight haplogroups showing significant phylogeographic pattern across the Western Palaearctic, corresponding to putative glacial refugia in Iberia, Central Europe, Turkey, and Iran. There were significant genetic discontinuities across the Pyrenees and the Anatolian diagonal but no impact of the Alps, suggesting that significant discontinuities have biotic rather than physical causes. Detailed analysis of sites in the Carpathian Basin reveal a high diversity and low spatial structure, and identify Central Europe as the source of colonists for Quaternary colonization of Germany, France, and Britain. We found no evidence for host‐associated differentiation of S. umbraculus lineages associated with the most common cynipid host galls, suggesting frequent shifts within the host gall assemblage by inquiline lineages. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 750–764.  相似文献   
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Several unanswered questions remain regarding the taxonomy and phylogeny of inquiline gallwasps (Cynipidae: Synergini), obligate inhabitants of plant galls induced primarily by other gallwasps (Cynipidae: Cynipini and Diplolepidini). Here we use morphological and molecular data to revise the inquiline genus Synophrus, members of which are notable for extensively modifying the structure of galls induced by oak gallwasp hosts on oaks in the section Cerris of Quercus subgenus Quercus in the Western Palaearctic. Previous taxonomic treatments have recognized three Western Palaearctic species of Synophrus: S. pilulae, S. politus and S. olivieri. Our results support the establishment of four additional Western Palaearctic species: Synophrus hungaricus sp.n. , S. libani sp.n. , S. syriacus sp.n. and S. hispanicus sp.n. We describe and diagnose these new taxa, analyse their phylogenetic relationships, and show that Synophrus inquilines are able to impose their own gall phenotypes on those of their hosts. We provide an updated key to Synophrus.  相似文献   
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Abstract Oak gallwasps (Hymenoptera; Cynipidae, tribe Cynipini) are cyclically parthenogenetic insects that induce galls on specific plant hosts in the family Fagaceae. Understanding the processes underlying the evolution of specific oak associations requires knowledge of the phylogenetic relationships among oak gallwasp genera. Although three major lineages of oak gallwasps have been identified, the status and relationships of several species‐poor but biologically significant genera remain unresolved. Two such genera are Chilaspis and Dryocosmus, whose western palaearctic species all gall oaks in the section Cerris. Dryocosmus is particularly significant biologically because it includes: (a) the only palaearctic gallwasp to gall chestnuts, Castanea, and (b) nearctic species. The oak section Cerris is wholly absent from the nearctic, and the relationship between palaearctic and nearctic Dryocosmus is significant for patterns of host plant evolution in the tribe as a whole. We examined the relationships between Chilaspis, Dryocosmus and other oak cynipid genera using cladograms from sequence data for two mitochondrial loci (cytochrome c oxidase subunit I and cytochrome b) and two nuclear loci (the 28S ribosomal gene regions D2 and D3–5). Our analyses support the following conclusions: (1) palaearctic Chilaspis and Dryocosmus species form an intermingled monophyletic group. (2) We propose that Chilaspis Mayr, 1881 is a syn.n. of Dryocosmus Giraud, 1859 and propose the name D. mayri as a comb.rev. for the species previously named C. mayri, and D. nitidus and D. israeli as comb.n. of C. nitida and C. israeli, respectively. (3) We reassess the utility of morphological characters previously regarded as diagnostic for these genera. (4) Two species previously known only from a single generation represent two halves of a single species lifecycle. Dryocosmus nervosus is here designated a syn.n. of D. cerriphilus. (5) The nearctic species D. favus lies outside the palaearctic Chilaspis/Dryocosmus clade, and Dryocosmus as currently recognized is not a monophyletic group. (6) Dryocosmus/Chilaspis is closely related to the other oak gallwasp taxa (Aphelonyx, Plagiotrochus, Pseudoneuroterus, Trichagalma, and some Neuroterus species) galling section Cerris oaks. This implies an early branching evolution of this oak association within this group, and supports previous work showing the rarity of oak gallwasp host shifts.  相似文献   
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