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71.
The elongated eye span of male Diopsid flies is a sexually selected character that scales positively with body size. Previously,
the duration of agonistic contests was found to increase as rival body size and eye span disparities decreased. Hence, along
with its role in mate choice, eye span seems to facilitate mutual assessment of rival size. However, such results are also
expected in the absence of rival assessment, when each individual persists according to its own size-dependent internal threshold.
Here, we reanalyze these contests to distinguish between these two hypotheses using two measures of size: body length and
eye span. Mutual assessment predicts that contest duration should increase with loser size and decrease with winner size.
In contrast, our results were more consistent with self-assessment: We found a positive relationship between loser size and
contest duration, whereas winner size did not affect contest duration. Thus, flies did not appear to assess the size of their
rivals, indicating that the mutual assessment function of eye span elongation may be less important than previously suspected.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
72.
73.
C. Stafford Brandt Chief 《Journal of the Air & Waste Management Association (1995)》2013,63(5):248-257
The absorption of hydrogen sulfide and methyl mercaptan by aqueous solutions of chlorine, sodium hydroxide, and chlorine plus sodium hydroxide was studied using a two-inch diameter absorption column packed with ¼ inch Intalox saddles. Absorption rates were noticeably affected by chemical reactions occurring in the aqueous chlorine and hydroxide media. These solutions were studied as a means of controlling sulfur-containing gas emissions from kraft paper mills. The absorption studies indicated that aqueous chlorine solutions at a pH above 12 were effective absorbents for hydrogen sulfide removal in absorption equipment designed to tolerate sulfur in suspension. The absorption of methyl mercaptan in aqueous chlorine solutions appeared to be impractical since dimethyl disulfide was apparently the only product formed and was stripped from the tower by the gas stream. Sodium hydroxide solution was an effective absorbent for both methyl mercaptan and hydrogen sulfide when hydroxide to sulfide or mercaptan feed ratios were greater than 1 or 1.8, respectively. The mercaptan absorption coefficient was approximately twice that for sulfide absorption. 相似文献
74.
Erik R. Hagen K. John. Holmes Julie E. Kiang Roland C. Steiner 《Journal of the American Water Resources Association》2005,41(6):1417-1430
The three largest water utilities in the Washington, D.C., metropolitan area (WMA) rely on the Potomac River and its reservoirs for water supply. These utilities have committed to a periodic review of the system's adequacy to meet future demands. In 1990, 1995, 2000, and again in 2004 (for publication in 2005) the utilities requested that the Interstate Commission on the Potomac River Basin (ICPRB) conduct a 20‐year water demand and resource adequacy study to fulfill this need. The selection of the five‐year interval provides multiple benefits. It allows regular updates and incorporation of recent demographic forecasts, and it increases visibility and understanding of the adequacy of the region's water resources. It also provides adequate time to conduct research on the physical system and to incorporate modifications based on this research into subsequent studies. The studies and lessons learned are presented in this case study of the WMA. The work has been a natural outgrowth of a long history of cooperative water supply planning and management among the main WMA water utilities and ICPRB. 相似文献
75.
Understanding the mechanisms and determinants of conflict resolution is of great theoretical and practical importance because
the outcome of contests between males over limited resources such as mates, territories, and food has profound fitness consequences.
Despite the large literature on the theory of conflict resolution, relatively few empirical studies explicitly test predictions
related to contest structure for these models. In sexually dimorphic species of stalk-eyed flies (Diopsidae), males engage
in characteristic aggressive interactions over both females and food resources. We used sequential analysis of aggressive
interactions between dyads of male stalk-eyed flies to investigate patterns of escalation, behavioral matching, and physical
contact in order to distinguish between three common models of conflict resolution: the sequential assessment model, the cumulative
assessment model, and the energetic war of attrition. Stalk-eyed flies were shown to engage in both low- and high-intensity
behaviors during interactions with patterns of escalation and no de-escalation. Aggressive interactions did not demonstrate
behavioral matching between winners and losers. Stalk-eyed flies also escalated to behaviors that included physical contact
without injuries. Our results provide support for the sequential assessment model based on patterns of escalation with no
de-escalation, behavioral mismatching, and behaviors which include physical contact but no injuries. 相似文献
76.
Spokes L Jickells T Weston K Gustafsson BG Johnsson M Liljebladh B Conley D Ambelas-Skjødth C Brandt J Carstensen J Christiansen T Frohn L Geernaert G Hertel O Jensen B Lundsgaard C Markager S Martinsen W Møller B Pedersen B Sauerberg K Sørensen LL Hasager CC Sempreviva AM Pryor SC Lund SW Larsen S Tjernström M Svensson G Zagar M 《Environmental pollution (Barking, Essex : 1987)》2006,140(3):453-462
This paper summarises the results of the EU funded MEAD project, an interdisciplinary study of the effects of atmospheric nitrogen deposition on the Kattegat Sea between Denmark and Sweden. The study considers emissions of reactive nitrogen gases, their transport, transformations, deposition and effects on algal growth together with management options to reduce these effects. We conclude that atmospheric deposition is an important source of fixed nitrogen to the region particularly in summer, when nitrogen is the limiting nutrient for phytoplankton growth, and contributes to the overall eutrophication pressures in this region. However, we also conclude that it is unlikely that atmospheric deposition can, on its own, induce algal blooms in this region. A reduction of atmospheric nitrogen loads to this region will require strategies to reduce emissions of ammonia from local agriculture and Europe wide reductions in nitrous oxide emissions. 相似文献
77.
Advanced paternal age (APA) is associated with infertility and other reproductive risks. Studies looking at APA and outcomes have used different paternal age cut-offs, which has complicated systematic evaluations of reproductive risk associated with paternal aging. This review of the literature suggests that the impact of paternal aging on adverse reproductive outcomes is small, but significant. Studies suggest the incidence of paternal age effect disorders attributed to de novo autosomal dominant mutations is less than 0.5%. Other risks associated with APA include infertility, miscarriage, birth defects, poor neurodevelopmental outcomes, and childhood cancer. Although the increasing prevalence of APA has mirrored the rise in maternal age, this topic has not received similar attention. In this review, we summarize the available literature on the reproductive risks associated with APA to provide a framework for comprehensive genetic counseling and evidence-based management of APA pregnancies. 相似文献
78.
Recent legislation mandates an increased role for public participation in natural resource policy making. This paper presents an operational way to provide those impacted with relevant information and to enable public officials to assess public reaction to proposed policies. The methodology transforms results obtained from a multisector model of income formation and distribution into positive economic measures of distributional impacts. The usefulness of the methodology is illustrated in the context of a policy to increase coal surface mining on public lands. 相似文献
79.
Interaction of soil pH and phosphorus efficacy: Long-term effects of P fertilizer and lime applications on wheat,barley, and sugar beet 总被引:3,自引:0,他引:3
Phosphorus (P), a plant macronutrient, must be adequately supplied for crop growth. In Germany, many soils are high in plant-available P; specifically in arable farming, P fertilizer application has been reduced or even omitted in the last decade. Therefore, it is important to understand how long these soils can support sustainable crop production, and what concentrations of soil P are required for it. We analyzed a 36-year long-term field experiment regarding the effects of different P application and liming rates on plant growth and soil P concentrations with a crop rotation of sugar beet, wheat, and barley. Sugar beet reacted to low soil P and low soil pH levels more sensitively than wheat, which was not significantly affected by the long-term omitted P application. All three crop species showed adequate growth at soil P levels lower than the currently recommended levels, if low soil pH was optimized by liming. The increase in efficacy of soil and fertilizer P by reduced P application rates therefore requires the adaptation of the soil pH to a soil type-specific optimal level. 相似文献
80.
By 2012, Hammarby Sjöstad, a former large industrial harbor area in southern Stockholm, Sweden, will be a fully developed residential district containing approximately 11,000 apartments and accommodating 35,000 people. The transformation of the area began in 1996, and the development soon became renowned for its ambitious environmental program, inspired by Agenda 21 (United Nations in Rio declaration on environment and development. United Nations Department of Economic and Social Affairs (DESA), Rio de Janeiro, 1992) and the Sydney 2000 Olympics in Australia (Newman in Landsc Urban Plan 44:219–226, 1999). Using results based on literature reviews, in-depth interviews, discussions with focus groups, and quantitative data, this paper attempts to gain insight into how the environmental program influenced the planning and performance of the district with regard to sustainable urban development. In doing so, three important conclusions were maintained that could be valuable for similar projects concerning the planning and development of sustainable urban districts. First, the environmental program proved vital to the development process of Hammarby Sjöstad, specifically in its drive to create a sustainable urban district. When planning on improving the sustainability of future districts, such a program should be introduced and integrated earlier in the planning stage of the district. Second, the metabolic flows of Hammarby Sjöstad were reduced as a result of the integrated system—the Hammarby Model—of Hammarby Sjöstad. In order to reduce the metabolic flows in future urban districts even further, it is important to facilitate the integration of technical innovations into existing integrated systems. Third, this case study showed that there was a loss of valid and credible data related to the aims and goals of the environmental program of Hammarby Sjöstad. In future urban districts, it is of the utmost importance to include a clear structure of the assessment process in the environmental program, which would ensure the quality of gathered data and facilitate the development of even better sustainable urban districts in the future. 相似文献