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91.
B. H. King 《Behavioral ecology and sociobiology》2000,48(4):316-320
In the parasitoid wasp Spalangia endius more offspring and a greater proportion of daughters were oviposited in, and emerged from 0-day-old versus 3-day-old hosts.
Offspring that developed on the younger hosts (1) were larger at adulthood, (2) developed more quickly, (3) had higher survivorship
to adulthood, and (4) were more often able to chew their way out of the host. Sons and daughters did not differ in how host
age affected their size, development rate, or survivorship. The greater proportion of daughters from the younger hosts may
be adaptive, as described by the host quality model (a variant of the Trivers and Willard hypothesis). It is adaptive if greater
size or more rapid development has a more positive effect on a daughter’s than a son’s fitness and the positive effect is
large enough to compensate for sons being trapped disproportionately to daughters in the older hosts. Despite greater success
at drilling the younger hosts, mothers did not try to drill them sooner or more often. Having previously oviposited on the
older rather than the younger hosts had no detrimental effect on the mother’s subsequent longevity or offspring production.
Received: 8 March 2000 / Revised: 9 June 2000 / Accepted: 24 June 2000 相似文献
92.
Outi Heikinheimo 《Ecological modelling》2011,222(10):1731-1742
The interactions between cod (Gadus morhua), herring (Clupea harengus) and sprat (Sprattus sprattus) in the Central Baltic Sea were examined with a simple dynamic model, an alternative to more complicated and data-demanding multispecies and ecosystem models. The main aims of the study were to compare the effect of alternative structures on the model output and examine the control relationships in the fish assemblage under different environmental conditions. The effect of environmental conditions was modelled using a stock-recruitment equation for cod incorporating an environmental index. The model output was especially sensitive to the functional response in predation by cod on herring and sprat. The type II functional response led to a collapse of the clupeid stocks when cod was abundant, while the type III response produced more realistic stock dynamics. According to the simulations, an abundant cod stock was able to keep the sprat stock at a low level, while the herring stock was less affected and benefited from the decreased density of sprat. Simulation of different fishing scenarios indicated that reducing fishing mortality to the level currently advised by ICES would allow the recovery of the cod stock even in unfavourable environmental conditions. 相似文献
93.
探讨不同臭氧度量指标对我国人群总死亡风险的影响.基于中国知网、万方数据库、维普中文服务平台、 Web of Science和PubMed数据库,检索了建库至2020年12月底发表的相关时间序列研究和病例交叉研究,最终纳入22项合格研究.按照臭氧每日1 h最大浓度(O3-M1h)、每日8 h最大平均浓度(O3-M8h)和每日24 h平均浓度(O3-24h)分别进行Meta分析.结果表明,O3-M1h指标(RR#, 1.005 2; 95%CI, 1.003 1~1.007 3)与人群总死亡风险增加的关联更加密切,O3-24h指标(RR#, 1.003 6; 95%CI, 1.002 5~1.004 8)和O3-M8h指标(RR#, 1.003 1; 95%CI, 1.002 2~1.004 1)关联较弱. 3类指标的亚组分析表明,冷季臭氧的总死亡风险更高,老年人(≥65岁)更容易受臭氧污染的影响,且北方地区总死亡风险高于南方地区. 相似文献
94.
为了评估PM2.5排放导致女性生殖系统癌症的风险以及城乡差异,以卵巢癌为例,分析了中国东部地区2000~2011年期间PM2.5和卵巢癌发病率和死亡率的相关关系,并估算了PM2.5排放导致卵巢癌发病率和死亡率升高的风险.结果表明,城市地区卵巢癌发病率和死亡率显著高于农村,在城市地区,PM2.5与卵巢癌发病率显著相关,PM2.5年平均浓度每上升10μg/m3,城市地区卵巢癌发病率上升的相对风险为9.3%(相对于PM2.5年平均浓度为35μg/m3时),每十万人口升高0.51人. 相似文献
95.
James W. N. Steenberg Pamela J. Robinson Andrew A. Millward 《Journal of Environmental Planning and Management》2018,61(3):553-567
Urban forest ecosystems are complex and vulnerable social–ecological systems. The relationship between urban forests and housing is particularly variable and uncertain. We examine the influence of building renovation and rental housing on public trees at the parcel and street-section scale in a residential neighbourhood in Toronto, Canada. We use empirical data describing multiple tree inventories and government open data describing building permit applications to test for effects on urban forest structure, tree mortality, and tree planting. We found that the presence and number of building permits significantly predicted mortality at both scales, while planting was positively correlated with building permits at the street-section scale only. Multi-unit parcels had significantly lower rates of planting than single-unit parcels and multi-unit housing was positively correlated with mortality at the street-section scale. These findings suggest that where concentrated changes in housing stock are occurring, substantial losses of trees and associated ecosystem services are possible. 相似文献
96.
Fisher WS Davis WP Quarles RL Patrick J Campbell JG Harris PS Hemmer BL Parsons M 《Environmental monitoring and assessment》2007,125(1-3):347-360
Coral reefs provide shoreline protection, biological diversity, fishery harvests, and tourism, all values that stem from the
physically-complex coral infrastructure. Stony corals (scleractinians) construct and maintain the reef through deposition
of calcium carbonate. Therefore, assessment of coral reefs requires at least some measurement endpoints that reflect the biological
and physical condition of stony corals. Most monitoring programs portray coral quantity as live coral cover, which is the
two-dimensional proportion of coral surface to sea floor viewed from above (planar view). The absence of the third dimension,
however, limits our ability to characterize coral reef value, physiology, health and sustainability. A three-dimensional (3D)
approach more realistically characterizes coral structure available as community habitat and, when combined with estimates
of live coral tissue, quantifies the amount of living coral available for photosynthesis, growth and reproduction. A rapid
coral survey procedure that coupled 3D coral quantification with more traditional survey measurements was developed and tested
in the field. The survey procedure relied on only three underwater observations – species identification, colony size, and
proportion of live tissue – made on each colony in the transect. These observations generated a variety of metrics, including
several based on 3D colony surface area, that are relevant to reef management. 相似文献
97.
环境空气细颗粒物(PM_(2.5))污染是我国目前较为突出的环境问题,也对人群健康造成严重威胁。基于国内外5套不同来源的2015年中国PM_(2.5)年均暴露浓度数据和5种暴露-反应关系(exposure-response,E-R)模型,设置了不同PM_(2.5)暴露浓度与E-R模型的25种组合情景,评估了2015年中国归因于环境PM_(2.5)导致的超额死亡数。结果表明,2015年全国(覆盖2 826个区县) PM_(2.5)相关超额死亡数为75.0万~256.5万例,其中应用国内E-R模型评估得到的超额死亡数(186.0万~256.5万例)大于国外模型评估得到的超额死亡数(75.0万~133.2万例);空间分布上,京津冀、河南、山东等重污染地区及人口密度较大地区的PM_(2.5)相关疾病负担较重,这些地区需制定更严格的政策来改善空气质量及保护公众健康。指出,我国地面监测站获得的暴露数据通常会高估全国PM_(2.5)的实际浓度均值,运用多套PM_(2.5)暴露浓度数据和多种E-R模型评估疾病负担,有利于减少评估的不确定性。提出,应加强我国PM_(2.5)与人群健康的队列研究及数据积累,以获取更准确的E-R关系,提升PM_(2.5)相关疾病负担评估结果的准确性。 相似文献
98.
通过收集广州市2011~2015年6种疾病(非意外因素、心血管疾病、脑卒中、缺血性心脏病、呼吸系统疾病以及慢性阻塞性肺疾病)逐日死亡人数、逐日NO2浓度以及同期气象资料,采用广义相加模型探讨了NO2暴露对不同疾病死亡的影响(相对危险度,RR值)和累积滞后效应,并进一步采用分层分析方法解析了冷季(11月至次年4月)和暖季(5~10月) NO2死亡风险的差异.结果表明,NO2影响急促短暂,通常持续4d.当NO2浓度升高10μg/m3,在Lag0-4d时,人群非意外死亡人数将上升2.18%(RR=1.0218;95% CI:1.0167,1.0270),在冷季与暖季分别上升2.6%(RR=1.0260;95% CI:1.0191,1.0328)与0.57%(RR=1.0057;95% CI:0.9952,1.0163),两者差异有统计学意义(P=0.002).在不同疾病中,NO2对慢性阻塞性肺疾病的影响最大.因而NO2仍然为广州地区人群健康重要的危险因素,需要加强NO2排放的控制与治理,并且加强冷季健康风险预警以保护公共健康. 相似文献
99.
Acute toxicity testing of some industrial effluents (rubber (Rr), brewery (Br), and bottling (Bt)) on Chironomus travalensis (Diptera larvae) was determined at 96-h using a static bioassay technique. Effluent quality characterization revealed acidic pH values of 4.5 for Rr, 5.64 for Br, and 4.32 for Bt effluents. Tests were carried out in replicates between 10 and 100% effluent concentrations. Mortality rate rose progressively with increasing concentrations. Bt effluent was the most toxic with 96-h LC50 of 61.5%, closely followed by Rr effluent with 96-h LC50 of 87% and the least toxic was Br effluent with 96-h LC50 of 90%. 相似文献
100.
地震房屋倒塌率CR和地震死亡率FR存在一定的关系,据此,本文研究计算得到了北京地区在未来地震中各类建筑可能造成的人员死亡率FR. 相似文献