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71.
Vincent Dietemann Jürgen Liebig Bert Hölldobler Christian Peeters 《Behavioral ecology and sociobiology》2005,58(5):486-496
In social insects, conflicts over male parentage can be resolved by worker policing. However, the evolution of policing behavior is constrained by the ability of individuals to identify reproductive nestmates, or their eggs. We investigated the occurrence of worker policing and its underlying chemical communication in the bulldog ant Myrmecia gulosa. Although workers have functional ovaries and can lay male-destined eggs, they do not reproduce in queenright colonies. To determine if their sterility is a consequence of worker policing, we experimentally induced worker reproduction in the presence of a queen. Some individuals were seized and immobilized by nestmates, and sometimes killed as a consequence. Although the ovarian development of immobilized individuals was variable, their cuticular hydrocarbon profiles were intermediate between reproductive and nonreproductive workers, indicating they were in the process of starting to reproduce. Approximately 29% of these incipient reproductive workers were successfully policed. To test for policing on eggs, we transferred viable worker eggs to queenright colonies and monitored their acceptance. Furthermore, we compared the surface hydrocarbons of the different types of eggs to determine whether these chemicals could be involved in egg recognition. We found that although there were differences in hydrocarbon profiles and discrimination between queen and worker-laid eggs, viable eggs were not destroyed. Our results strongly support the idea that cuticular hydrocarbons are involved in the policing of reproductive workers. A low level of worker policing appears sufficient to select for self-restraint in workers when few fitness benefits are gained by selfish reproduction. Policing of eggs may thus be unnecessary. 相似文献
72.
Bert Hölldobler 《Behavioral ecology and sociobiology》1976,1(1):3-44
1. | Scouts of the harvester ant Pogonomyrmex barbatus, P. maricopa and P. rugosus which discovered a new rich foraging area recruit nestmates by laying a trail with poison gland contents from the feeding site to the nest. Laboratory experiments have shown that Pogonomyrmex workers are stimulated to follow the trail by the trail pheromone alone. |
2. | The biological significance of the recruitment behavior was analyzed in the mesquite-acacia desert in Arizona-New Mexico, where the three species occur sympatrically. P. maricopa recruits less efficiently to food sources than does P. barbatus and P. rugosus. Generally the recruitment activity depends on a number of parameters of the food source, such as distance to the nest, density of the seed fall and size of the grains. |
3. | The recruitment activity is also affected by the presence, absence or distance of hostile neighboring colonies. |
4. | The use of chemically and visually marked trunk trails which originate from recruitment trails, guarantees and efficient partitioning of foraging grounds. It could be demonstrated that trunk trails, used by P. barbatus and P. rugosus during foraging and homing, have the effect of avoiding aggressive confrontations between neighboring colonies of the same species. They channel the mass of foragers of hostile neighboring nests into diverging directions, before each ant pursues its individual foraging exploration. This channeling subtly partitions the foraging grounds and allows a much denser nest spacing pattern than a foraging strategy without trunk trails, such as that employed by P. maricopa. |
5. | The behavioral mechanisms which maintain overdispersion both within and between species of Pogonomyrmex were investigated. Aggressive confrontations at the colony level and aggressive expulsion of foundress queens from the nest territories of mature colonies play thereby a major role. Observational as well as experimental data led to the conclusion that the farther away from its nest the intruder is, the less vigorous are the aggressive confrontations with the defenders. Only when neighboring colonies are located too close together will increased aggressive interactions eventually lead to the emigration of the weaker colony. |
6. | P. barbatus and P. rugosus have a wide niche overlap, whereas P. maricopa seems to be more specialized in regard to food. This is consistent with the findings that interspecific territoriality between P. barbatus and P. rugosus is considerably more developed than between these species on the one side and P. maricopa on the other. |
7. | Although foundress queens, which venture into a territory of a conspecific mature colony are fiercely attacked, most of them are not injured, but rather dragged or carried to the territorial border and then released. |
8. | Nevertheless foraging areas, even of conspecific colonies, frequently overlap, but aggressive interactions there are usually less intense than at the core areas (trunk trails plus nest yards), which normally do not overlap and are vigorously defended. |
73.
Summary Field observations and laboratory experiments demonstrate that in the Australian meat ant, Iridomyrmex purpureus, the modes of colony founding are remarkably diverse. New colonies can originate from single foundresses (haplometrosis), or foundress associations (pleometrosis), or by colony budding, or the adoption of newly-mated queens that dig founding chambers next to mature nests (probably their natal nests, as workers protect them and may help them dig). Readoption of foundresses and pleometrosis lead to the coexistence of several queens in one nest. We discovered a striking antagonistic behavior among coexisting queens in young colonies, in the form of ritualized antennation bouts. These interactions result in a reproductive rank order in which dominant queens inhibit egg-laying by subordinates, but escalation into physical fighting is rare. Workers ignore queen dominance interactions and treat all queens equally. The first quantitative ethogram of dominance display behavior between multiple ant queens, and its reproductive consequences, is presented. As a colony grows, queens become intolerant of each other's presence and permanently separate within the nest. Once separated, queens appear to be equal in status, laying approximately equal numbers of eggs. All queens continue to be tolerated by workers, even when the colony has reached a size of several thousand workers and begun to produce reproductives. Such mature nests of I. purpureus fulfill the criteria of oligogyny, defined by worker tolerance toward more than one queen and antagonism among queens, such that a limited number of fully functional queens are spaced far apart within a single colony. Oligogynous colonies can arise in this species by pleometrotic founding (primary oligogyny) or by adoption of queens into existing nests (secondary oligogyny). The adaptive significance of the complex system of colony founding, queen dominance and oligogyny in I. purpureus is discussed. 相似文献
74.
The origin of the presence of soil elements in the epiphytic lichen Lecanora conizaeoides was investigated in an area of heavily polluted soil (The Broekpolder The Netherlands). Analysis results of lichens, bark and tree rings of the supporting trees indicated that for As, Co, Cr, Cu, Fe, Hg, Sc and V the levels in lichens may be considered to originate from wet and dry deposition. The Cd, Mn and Zn levels in lichens might have originated from both wet and dry deposition and the substrate bark. For these three elements, in particular, accumulation characteristics in lichens should be further investigated. 相似文献
75.
Frank van der Meulen Bert van der Valk Laurens Baars Eduard Schoor Hans van Woerden 《Journal of Coastal Conservation》2014,18(5):505-513
A new dune area was constructed by beach and foreshore nourishments along the Delfland Coast in the southwestern Netherlands. The new area is intended to be a compensation for losses of existing high quality dunes in nearby areas, due to the use/construction of Maasvlakte 2, the new harbour extension of Rotterdam opening in 2013. The target habitats for compensation include dry grey dunes and moist dune valley grassland. Due to the habitat type, the nourished material had to have a special character. The nourishment was carried out according to a special design and initial development of the new area had to follow certain pathways. In order to meet the compensation requirements in time. Careful monitoring is done to assess whether development of the new habitat is taking place in the direction of the desired target habitats. This paper reports on the construction of the new area and on the first years of development and monitoring. The monitoring mainly concerns development of the abiotic landscape elements, geomorphology, groundwater and soils. The lessons learned from this area are discussed in the light of the development of other recent young nature areas in the sandy Dutch delta coast. This gives new insights for coastal management in general in the context of building with nature. 相似文献
76.
Potentially Allergenic Airborne Particles in the Vicinity of a Yeast and Penicillin Production Plant
Liesbeth Preller Albert Hollander Dick Heederik Bert Brunekreef 《Journal of the Air & Waste Management Association (1995)》2013,63(8):1094-1097
Potential health risks of exposure to emissions of a yeast and penicillin production plant were investigated by measuring viable particles and protein contents of particles in ambient air. The results showed a clear decrease of the downwind number of yeast colonyforming units with increasing distance from the source. Upwind the number of yeast colony-forming units was zero. Identification showed that nearly all yeast were of the species Saccharomlces cerevisiae. Such a trend could not be found for the total number of colony-forming units (yeasts, molds, and bacteria) although the upwind concentration was slightly lower than the downwind concentration. The downwind protein concentration was significantly elevated compared to the upwind concentration. 相似文献
77.
Wolkers H Hammill MO van Bavel B 《Environmental pollution (Barking, Essex : 1987)》2006,142(3):476-486
Accumulation and mother-pup transfer of halogenated organic contaminants was studied in hooded seal tissues from eastern Canada. Blubber polychlorinated biphenyl (PCB) and total pesticide concentrations were relatively high, possibly due to their high trophic level and demersal feeding habits. Blood plasma showed the lowest contaminant concentrations compared to blubber and liver, possibly due to a lower affinity of these compounds to lipoproteins in blood plasma. Total contaminant body burden correlated well with blubber, liver, and milk contaminants, but not with blood plasma contaminants, indicating that blood plasma might be less suitable to monitor contaminants in hooded seals. Lactational transfer favored less lipophilic contaminants and was associated with relatively high blood plasma PCB and polybrominated diphenyl ether concentrations in females. Despite lactational transfer, females did not show significantly lower blubber contaminant concentrations or burdens than males. This might be caused by their low blubber, and thus contaminant, loss during lactation compared to other species. 相似文献
78.
Olsman H Hagberg J Kalbin G Julander A van Bavel B Strid A Tysklind M Engwall M 《Environmental science and pollution research international》2006,13(3):161-169
Goal, Scope and Background The use of polybrominated diphenyl ethers (PBDEs) as flame retardants increases the risk for emissions of other brominated
compounds, such as polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). The large homology in structure of PBDD/Fs
and mechanism of toxic action, i.e. the capacity to activate the Ah receptor (AhR) pathway, compared to their well-studied
chlorinated analogues, justifies a raised concern to study the environmental levels and fate of these compounds. Decabromodiphenyl
ether (decaBDE) is the most widely used PBDE today. Studies on photolytic debromination of decaBDE in organic solvents have
shown debromination of decaBDE, as well as formation of PBDFs. However, little is known about the transformation mechanisms
and there are only scarce data on photoproducts and PBDE transformation in environmentally relevant matrices. In this study,
mechanism-specific dioxin bioassays were used to study photolytic formation of AhR agonists in toluene solutions of decaBDE.
In addition, the influence of irradiation time and UV-light wavelength on the formation was studied. PBDE congener patterns
and presence of PBDD/Fs were analysed. Further, AhR agonists were analysed in agricultural soils contaminated with PBDEs.
Soils were also exposed to UV-light to study changes in AhR agonist levels.
Methods Toluene solutions of decaBDE were irradiated using three different spectra of UV-light, simulating UV-A (320-400 nm), UV-AB
(280-400 nm), and UV-ABC (250-400 nm). Additionally, decaBDE solutions were exposed to narrow wavelength intervals (10 nm
bandwidth) with the central wavelengths 280, 290, 300, 310, 320, 330, 340, 350, 360 nm. AhR agonists in decaBDE solutions
were analysed with two different bioassays, the chick embryo liver-cell assay for dioxins (Celcad) and the dioxin responsive,
chemically activated luciferase expression assay (DR-Calux). Also, the decaBDE solutions were analysed with LRGC-LRMS to obtain
PBDE congener patterns for breakdown of decaBDE, and with HRGC-HRMS, for presence of PBDD/Fs. Four soils were exposed to UV-AB
light, under both dry and moist conditions. Levels of AhR agonists in soil extract fractions, before and after UV-exposure,
were analysed with the DR-Calux.
Results and Discussion Significant levels of photoproducts able to activate the AhR pathway, up to 31 ng bio-TEQ/ml, were formed in UV-exposed decaBDE
solutions. The transformation yield of decaBDE into AhR agonists was estimated to be at the 0.1%-level, on a molar basis.
The net formation was highly dependent on wavelength, with the sample irradiated at 330 nm showing the highest level of dioxin-like
activity. No activity was detected in controls. PBDE analysis confirmed decaBDE degradation and a clear time-dependent pattern
for debromination of PBDE congeners. AhR agonist effect in the recalcitrant fractions of the soils corresponded to the levels
of chemically derived TEQs, based only on chlorinated dioxin-like compounds in an earlier study. It was concluded that no
significant levels of other AhR agonists, e.g. PBDFs, were accumulated in the soil. UV-light caused changes in AhR-mediated
activity in the more polar and less persistent fractions of the soils, but it is not known which compounds are responsible
for this.
Recommendations and Perspective . The laboratory experiments in this study show that high levels of AhR agonists can be formed as photoproducts of decaBDE
and it is important to elucidate if and under which conditions this might occur in nature. However, soil analysis indicates
that photoproducts of PBDE do not contribute to the accumulated levels of persistent dioxin-like compounds in agricultural
soil. Still, more data is needed to fully estimate the environmental importance of PBDE photolysis and occurrence of its photoproducts
in other environmental compartments. Analysis with dioxin bioassays enabled us to gather information about photoproducts formed
from decaBDE even though the exact identities of these compounds were not known.
Conclusion Bioassays are valuable for studying environmental transformation processes like this, where chemical analysis and subsequent
toxicological evaluation requires available standard compounds and information on toxicological potency. The use of bioassays
allows a rapid evaluation of toxicological relevance. 相似文献
79.
Sheng Fulai Gary Flomenhoft Timothy J. Downs MaÁngeles Grande‐Ortiz Dana Graef Bert Scholtens Arthur P.J. Mol David A. Sonnenfeld Gert Spaargaren Rajeev K. Goel Edward W.T. Hsieh Serban Scrieciu Reinhard Steurer Christine Polzin Genia Kostka Tiho Ancev Elke Pirgmaier Frank Boons Karl‐Henrik Robèrt Christopher Bryant Ke Zhou Surya Raj Acharya David Huberman Denis J. Sonwa Michelle Mycoo Dabo Guan Klaus Hubacek U. Rashid Sumaila Hector G. Lopez‐Ruiz G. Jason Jolley Michael L. Dougherty André Francisco Pilon Ravi Prakash Tulus Tambunan Sebastian Hermann 《Natural resources forum》2011,35(1):63-72
80.
The linearity of the interspecies relation between the elemental contents in Parmelia sulcata and Lecanora conizaeoides, sampled in a polluted area, was examined by the function y=az+b and yz
–1=a+bz
–1, with y and z being the elemental content in Parmelia and Lecanora, respectively. For As, Co, V and Zn significant positive a and b values were found, allowing interspecies calibration. For Br, Cd, Cr, Fe, La, Sb, Se and W the a values were zero and the b values were positive, indicating saturation of Parmelia and thus ruling out interspecies calibration. For Cu a part of the data set showed saturation effects in Lecanora. The results showed that the average concentration ratio could not be used for intercalibration purposes, because the concentration ratios were dependent on the concentrations. 相似文献