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991.
Sami M. Kivel? Panu V?lim?ki David Carrasco Maarit I. M?enp?? Satu M?ntt?ri 《Die Naturwissenschaften》2012,99(8):607-616
A resource allocation trade-off is expected when resources from a common pool are allocated to two or more traits. In holometabolous insects, resource allocation to different functions during metamorphosis relies completely on larval-derived resources. At adult eclosion, resource allocation to the abdomen at the expense of other body parts can be seen as a rough estimate of resource allocation to reproduction. Theory suggests geographic variation in resource allocation to the abdomen, but there are currently no empirical data on it. We measured resource allocation to the abdomen at adult eclosion in four geometrid moths along a latitudinal gradient. Resource (total dry material, carbon, nitrogen) allocation to the abdomen showed positive allometry with body size. We found geographic variation in resource allocation to the abdomen in each species, and this variation was independent of allometry in three species. Geographic variation in resource allocation to the abdomen was complex. Resource allocation to the abdomen was relatively high in partially bivoltine populations in two species, which fits theoretical predictions, but the overall support for theory is weak. This study indicates that the geographic variation in resource allocation to the abdomen is not an allometric consequence of geographic variation in resource acquisition (i.e., body size). Thus, there is a component of resource allocation that can evolve independently of resource acquisition. Our results also suggest that there may be intraspecific variation in the degree of capital versus income breeding. 相似文献
992.
Karen Hardy Stephen Buckley Matthew J. Collins Almudena Estalrrich Don Brothwell Les Copeland Antonio García-Tabernero Samuel García-Vargas Marco de la Rasilla Carles Lalueza-Fox Rosa Huguet Markus Bastir David Santamaría Marco Madella Julie Wilson ángel Fernández Cortés Antonio Rosas 《Die Naturwissenschaften》2012,99(8):617-626
Neanderthals disappeared sometime between 30,000 and 24,000?years ago. Until recently, Neanderthals were understood to have been predominantly meat-eaters; however, a growing body of evidence suggests their diet also included plants. We present the results of a study, in which sequential thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) were combined with morphological analysis of plant microfossils, to identify material entrapped in dental calculus from five Neanderthal individuals from the north Spanish site of El Sidrón. Our results provide the first molecular evidence for inhalation of wood-fire smoke and bitumen or oil shale and ingestion of a range of cooked plant foods. We also offer the first evidence for the use of medicinal plants by a Neanderthal individual. The varied use of plants that we have identified suggests that the Neanderthal occupants of El Sidrón had a sophisticated knowledge of their natural surroundings which included the ability to select and use certain plants. 相似文献
993.
Despite a rapidly improving fossil record, the reproductive biology of Mesozoic birds remains poorly known: only a handful of undisputed, isolated Cretaceous eggs (some containing embryonic remains) are known. We report here the first fossil evidence for a breeding colony of Mesozoic birds, preserved at the Late Cretaceous (Maastrichtian) Oarda de Jos (Od) site in the Sebe? area of Transylvania, Romania. A lens of calcareous mudstone with minimum dimensions of 80?cm length, 50?cm width and 20?cm depth contains thousands of tightly packed, morphologically homogenous eggshell fragments, seven near-complete eggs and neonatal and adult avialan skeletal elements. Eggshell forms 70–80?% of the matrix, and other fossils are entirely absent. The bones exhibit clear characters of the Cretaceous avialan clade Enantiornithes, and the eggshell morphology is also consistent with this identification. Both taphonomy and lithology show that the components of this lens were deposited in a single flood event, and we conclude that it represents the drowned remains of a larger enantiornithine breeding colony, swamped by rising water, washed a short distance and deposited in a shallow, low-energy pond. The same fate often befalls modern bird colonies. Such a large concentration of breeding birds suggests aquatic feeding in this species, augments our understanding of enantiornithine biology and shows that colonial nesting was not unique to crown birds. 相似文献
994.
With regard to automotive traffic, a tunnel-type semi enclosed atmosphere is characterized by a higher concentration of gaseous pollutants than on urban traffic roads and highlights the gaseous effluent species having an impact on material degradation. Therefore, a transverse approach between air quality and its consequences upon the longevity of materials is necessary, implying better knowledge of tunnel atmosphere and a better understanding of material degradation inside a tunnel for operating administration. Gaseous pollutant measurements carried out in a road tunnel in Rouen (Normandy) give the real world traffic concentrations of experimental exposure conditions. The sampling campaigns, achieved in summer and winter include SO2, NO2, BTEX and aldehyde analyses. Effluent profiles in the upward and downward tubes have been established. The current work shows that SO2, NO2, formaldehyde, acetaldehyde, propanal and butanal must be considered in the degradation process of materials in a stuffy environment. As regards NO2, its concentration depends on the modification of the automotive fleet. The total aldehyde concentrations indicate no particular trend between the two bores. Formaldehyde, acetaldehyde, propanal, butanal and acrolein species are the most abundant species emitted by vehicles and represent 90% to 95% of the total aldehyde emissions. 相似文献
995.
The present article studies the effect of CeO2 and Al2O3 on the activity of Pd/Co3O4/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/Co3O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation (CO + O2 and CO + NO) and total hexane oxidation (C6H14 + O2). Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/Co3O4/cordierite. The second support decreases the activity of Pd/Co3O4/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of CoAl2O4 formation. 相似文献
996.
Xiaoguang Liu Mohammad M.I. Chowdhury Masuduz Zaman Mingu Kim George Nakhla 《环境科学学报(英文版)》2019,31(8):169-178
This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants(K_(I,Ni)) for ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors(SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μ_(max), b, and K_o of AOB were 0.16 day~(-1), 0.098 day~(-1) and 2.08 mg O_2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen(DO)(7 mg/L) and long solids retention time(SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible. 相似文献
997.
Adánez-Rubio Iñaki Pérez-Astray Antón Abad Alberto Gayán Pilar De Diego Luis F. Adánez Juan 《Mitigation and Adaptation Strategies for Global Change》2019,24(7):1293-1306
Mitigation and Adaptation Strategies for Global Change - Bioenergy with carbon dioxide (CO2) capture and storage (BECCS) technologies represent an interesting option to reach negative carbon... 相似文献
998.
Variation in vocal behavior among local populations of songbirds may be significant to females in mate choice. In a study of dialect populations of brown-headed cowbirds, estradiol-implanted females from two dialects held the pre-copulatory lordosis posture longer in response to playback of the local flight whistle song than to foreign whistle types from adjacent and more distant dialects. Females were held in captivity for a relatively brief period prior to testing and received no tutoring so discrimination was based solely on experience in the wild. This is the first study to show evidence of discrimination by female cowbirds based on flight whistle type. Evidence is presented from one of the study dialects that the majority of yearling male cowbirds are vocally distinct from resident adults in having either foreign or incomplete local whistles. Although these yearlings are fully mature sexually, they have little or no mating success. The correlation between female whistle preference and male mating success suggests that the ability to give the correct local whistle type may be a characteristic used by females to assess age and quality of a potential mate. A learned female preference for the predominant local song type may be a factor in the stability of these dialects by making it adaptive for males to conform to the local dialect. 相似文献
999.
1000.