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211.
1. Figs and pollinating fig wasps provide a model system for studying mutualism. The permeability of the syconium changes during receptivity or between seasons, which may affect the behaviour of pollinators. Fig fruits are permeable during receptivity, and in some species, pollinators can enter and re‐emerge after oviposition/pollination. We studied the relationship between fig permeability and pollinator re‐emergence behaviour with a functional dioecious fig, Ficus hispida and the obligate pollinator Ceratosolen solmsi marchali. 2. The relationship reflects the interaction of figs and pollinators in the mutualism and also the conflicts of interests between the two partners: figs benefit from the enclosed fig fruits which have low permeability, but pollinators benefit from their re‐emergence behaviour, which requires high fig permeability. 3. The results showed that at the end of receptivity, the permeability of fig fruits lowered rapidly with changes to the ostiole structures, and re‐emergence rate was low, with more re‐emerging pollinators trapped in the ostiolar bracts. Our results also showed that in the rainy season, the length of receptivity was shorter and fig permeability was lower. The re‐emergence rates were also lower than those in the dry season. The results elucidated that figs' interests dominated in the conflicts between fig and pollinating wasp. 4. Based on a new criteria which employed the classification of pollinators found dead in the ostiolar bracts and which involved a survey of 6 monoecious and 12 dioecious fig species, we found that re‐emergence behaviour was prevalent among fig species, and was more prevalent in functional dioecious figs than monoecious ones.  相似文献   
212.
Da Silva, A.‐C., Kershaw, S. & Boulvain, F. 2011: Sedimentology and stromatoporoid palaeoecology of Frasnian (Upper Devonian) carbonate mounds in southern Belgium. Lethaia, Vol. 44, pp. 255–274. Stromatoporoids are the most abundant large skeletal organisms in middle Frasnian carbonate mound environments of southern Belgium. They occur in environments ranging from flank and off‐mound, mound core, shallow mound and restricted mound. A detailed log and comprehensive sampling of stromatoporoids in a single section cutting through all middle Frasnian mound levels in La Boverie–Rochefort Quarry, near Rochefort and Dinant reveals a stromatoporoid assemblage comprising 10 genera; 472 samples, containing an overall total of 3079 stromatoporoids (including complete and fragmented specimens) have been studied. The following list gives abundance using numbers of specimens and areas of total stromatoporoid area on outcrop surfaces (% number; % area in cm2): Actinostroma (0.4; 9.2), Amphipora (15.5; 1.7), Atelodictyon (0.2; 4.4), Clathrocoilona (0.3; 0.5), Euryamphipora (13.7; 0.7), Idiostroma (2; 1.9), Salairella (1.2; 9.6), branching Stachyodes (43.2; 59.1), laminar Stachyodes australe (1.9; 1.3), Stictostroma (4.8; 13.1) and Trupetostroma (0.2; 0.8), showing that Stachyodes is approximately half of the total assemblage. Deeper environments contain more abundant low profile forms, shallow water facies contain more domical and bulbous forms; branching forms are ubiquitous. Low profile stromatoporoids are likely to have been important sediment stabilizers that may have led to expansion of the carbonate factory, and they may have therefore contributed to the structural building of the mounds. Stromatoporoid‐coral intergrowths are observed in only Stictostroma suggesting that there is a close biological relationship between them; however, stromatoporoid skeletons in almost all cases appear to be unaffected by the presence of intergrown corals, suggesting they were commensals. □Frasnian, Late Devonian, mounds, palaeoecology, stromatoporoid.  相似文献   
213.
1. The underlying basis of alternative male reproductive strategies is either genetic or environmental. Several non‐pollinating fig wasp lineages have dimorphic males, typically with winged males that disperse from natal figs to mate and flightless males that seek mating opportunities in natal figs. 2. Walkerella sp. from Ficus benjamina has dark and pale wingless males. Observations and experiments in Xishuangbanna, Southern China found that (i) the sex ratio of Walkerella sp. did not vary with foundress number or brood size. (ii) The frequency of dark males increased with brood size and foundress number and they were absent from figs with a single foundress. This produced a higher proportion of dark males at higher densities. (iii) Males of both morphs fought, but injuries to dark males were more frequent. (iv) Dark males were more likely to disperse away from their natal figs and (v) they were more resistant to dehydration. 3. Responses to selection are constrained by the genetic options available. Consequently, selection pressures acting on different lineages can produce similar outcomes that are achieved in different ways. Walkerella species lack winged males, but dark males display some of their features, dispersing from natal figs and displaying appropriate physiological and behavioural adaptations. However, dark males also displayed increased levels of damage from fighting – a feature unlikely to be shared with the winged males of other species.  相似文献   
214.
上海两种新记录植物   总被引:2,自引:0,他引:2  
报道了上海2种新分布植物:禾本科的日本莠竹[Microstegium japonicum (Miq.) Koidz.]和菊科的卤地菊[Wedelia prostrata (Hook.et Arn.) Hemsl.].  相似文献   
215.
216.
The phylogeographic structure of 15 genera of Amazonian marsupials and rodents is summarized based on comparative sequence of the mitochondrial cytochrome b gene. The data are limited in geographical coverage, with samples widely scattered throughout Amazonia from the base of the Andes in Peru to the Guianan coast and eastern Brazil. We use this approach to define species boundaries, based minimally on the principle of reciprocal monophyly, in conjunction with morphological or other genetic discontinuities. The taxa so defined are older than previously appreciated, with many lineages dating from 1 to more than 3 Myr, and thus apparently predating the early Pleistocene. We relate patterns of concordant geographical shifts with underlying tectonic history and to current positions of major rivers. Finally, we provide comments on the utility of these data and patterns to conservation, articulating a need to incorporate phylogeographic information as part of the rationale in establishing conservation priorities at the organismal and geographical area levels.  相似文献   
217.
218.
Abstract: Stromatoporoid faunas in the Frasnian of southern Belgium are abundant in the carbonate platform environments present in this area. Stromatoporoids dominate the large skeletal organisms and occur principally in biostromes. The stromatoporoid assemblage is represented by a small number of taxa. Stromatoporoid genera include Actinostroma, Amphipora, Atelodictyon, Clathrocoilona, Salairella, Stachyodes, Stictostroma, Stromatopora and Trupetostroma which are present in environments ranging from the outer, outer intermediate, inner intermediate and inner zones and associated biostromes. Most large skeletal stromatoporoids are low profile, which reinforces the conclusions of previous studies that low‐profile growth forms were the most successful stromatoporoid forms. These low‐profile forms are likely to have been important sediment stabilisers that may have led to expansion of the carbonate factory. Growth forms vary between facies, indicating some degree of environmental control on form; for example, laminar in the intermediate zone, bulbous and domical in the inner and outer zones. Stromatoporoid taxa vary in occurrence across the environmental gradient from shallow to deep. There is some taxonomic control on growth forms, with some taxa showing more variability than others in different environments.  相似文献   
219.
The effect of some fresh‐cut carrot label attributes on consumer purchase intention was evaluated using conjoint analysis. The following three attributes were chosen and manipulated: price (high and low), packaging type (polyethylene bags and expanded polystyrene trays) and production process (organic with certification stamp, organic without certification stamp and no information). A complete factorial design was used, and 12 hypothetical packages of fresh‐cut carrot were developed and evaluated by 96 consumers based on their purchase intention. The consumers were divided into four groups with different opinions. Low price and organic with certification label were the favorite choices of the groups. Only one group preferred expanded polystyrene trays. No interactions were exhibited among the attributes in all groups.  相似文献   
220.
We report clear evidence that the interaction of the CD38 molecule with the specific mAb A10 on normal human cells and lines modulates the expression of surface activation markers relevant to T, NK, and plasma cell biology and functions. Moreover A10 mAb binding is followed by proliferation effects on all the target cells analyzed, and the phenomenon is accessory cell and IL-2 dependent. The effects of A10 mAb synergizing both CD2 and CD3 activation pathways indicate that CD38 signal transduction mechanism(s) are apparently different from the aforementioned. Nevertheless the decreased A10-driven proliferation after CD3-Ti modulation suggests a possible functional interdependence between these activation pathways. Taken together, the results indicate that the CD38 molecule might play a physiologic role in T, NK, and plasma cell regulation.  相似文献   
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