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101.
102.
Summary. Queens in colonies of the small myrmicine ant, Leptothorax gredleri Mayr 1855 (Hymenoptera, Formicidae) engage in dominance interactions and form social hierarchies, in which typically only the top-ranking queen lays eggs. Occasionally, queen antagonism escalates to violent mandible fighting, during which the sting is used to apply Dufour gland secretions onto the cuticle of the opponent. Contaminated queens often are attacked by nestmate workers. Here we show that the chemical composition of the Dufour gland is colony-specific and that workers can discriminate between secretions from their own and other colonies. Our findings suggest that Dufour gland secretions are involved in the establishment of hierarchies within a colony. When invading an alien colony the queen presumably employs the secretions during the expulsion of the resident queen. Apparently, Dufour gland secretions play a role in intraspecific queen competition similar to that in slave-making and inquiline formicoxenine ants, where they function as "propaganda substances" in an interspecific context. Received 7 July 1998; accepted 15 September 1998.  相似文献   
103.
Many current audit programs are very good at determining the compliance issues at a site, but are less successful in developing long-term compliance solutions. One method for addressing these issues is the use of root cause analysis techniques. These techniques allow the facility to identify and focus on permanent solutions to compliance issues. The authors note the following: Conducting a root cause analysis is not a substantial burden on the audit team or the facility. Most information is already collected during the audit, but is not being used. Looking at the overview pattern of the root cause analysis can provide a picture of the maturity of your audit program. Pareto charts are excellent methods to convey the results of your analysis. They show both the trends of analysis and help highlight the most significant root causes.  相似文献   
104.
The US Environmental Protection Agency recently completed two regulatory negotiation demonstrations. These demonstrations suggest that the current EPA rule-making process could be improved through the introduction of face-to-face negotiation at the earliest stages of rulemaking. In the demonstrations, EPA (1) relied on a consensus building process to forestall litigation after the promulgation of the final rule; (2) Used a nonpartisan facilitator to convene the negotiations; (3) Defined criteria to determine which parties should be represented in the negotiation. From the perspective of participants, the negotiating consensus version of a draft regulation is a successful alternative to the traditional rulemaking process. It is still too soon to say negotiated rulemaking significantly reduces the likelihood of ligitation. The results of the demonstration indicate that it is possible for either an agency employee or a neutral outsider to facilitate the sessions. A successful negotiation also requires top level agency support as well as the confidence of the environmental community. The single most important outcome of the negotiations was that the participants developed a greater understanding of the interests of the other parties. The demonstrations also suggest possible changes in future regulatory negotiations.  相似文献   
105.
Being constantly connected to others via e‐mail and other online messages is increasingly typical for many employees. In this paper, we develop and test a model that specifies how interruptions by online messages relate to negative and positive affect. We hypothesize that perceived interruptions by online messages predict state negative affect via time pressure and that perceived interruptions predict state positive affect via responsiveness to these online messages and perceived task accomplishment. A daily survey study with 174 employees (a total of 811 day‐level observations) provided support for our hypotheses at the between‐person and within‐person level. In addition, perceived interruptions showed a negative direct association with perceived task accomplishment. Our study highlights the importance of being responsive to online messages and shows that addressing only the negative effects of perceived interruptions does not suffice to understand the full impact of interruptions by online messages in modern jobs.  相似文献   
106.
The expert panel for biological indication and effect research of the state institutes and agencies, pursues the harmonisation and optimisation of methods used for biological indication since 1980. This demonstrated increased significance after the fall of the Berlin Wall and the admission of the new German states, formerly East Germany. The publication of recommendations and the co-operation with other panels of experts (for example the VDI (association of German engineers) build the basis for the expert panel’s effect on the public. As first federal biological indication system, the expert panel, together with the federal institute for the environment, introduced moss-monitoring in the Federal Republic of Germany. For the future, the main point of effort will still lie in the exchange of information between state agencies and the harmonisation of methods. Above this, the expert panel should control the co-ordination of biological indication for a federal environment surveillance, develop evaluation strategies and methods, point out research deficiencies and develop new methods when necessary. Thus, for example, the expert panel has to point out possible connections and co-operations towards the monitoring of genetically manipulated organisms and changes in climate. Existing biological indication methods, including moss-monitoring, are to be screened for actuality and, when necessary, are to undergo further developments. The expert panel will also work on the development of effect-related environmental indicators as tools for an indication of ecological sustainability.  相似文献   
107.
108.
Buchanan, Brian, Zachary M. Easton, Rebecca Schneider, and M. Todd Walter, 2011. Incorporating Variable Source Area Hydrology Into a Spatially Distributed Direct Runoff Model. Journal of the American Water Resources Association (JAWRA) 48(1): 43‐60. DOI: 10.1111/j.1752‐1688.2011.00594.x Abstract: Few hydrologic models simulate both variable source area (VSA) hydrology, and runoff‐routing at high enough spatial resolutions to capture fine‐scale hydrologic pathways connecting VSA to the stream network. This paper describes a geographic information system‐based operational model that simulates the spatio‐temporal dynamics of VSA runoff generation and distributed runoff‐routing, including through complex artificial drainage networks. The model combines the Natural Resource Conservation Service’s Curve Number (CN) equation for estimating storm runoff with the topographic index concept for predicting the locations of VSA and a runoff‐routing algorithm into a new spatially distributed direct hydrograph (SDDH) model (SDDH‐VSA). Using a small agricultural watershed in central New York, SDDH‐VSA results were compared to those from a SDDH model using the traditional land use assumptions for the CN (SDDH‐CN). The SDDH‐VSA model generally agreed better with observed discharge than the SDDH‐CN model (average, Nash‐Sutcliffe efficiency of 0.69 vs. 0.58, respectively) and resulted in more realistic spatial patterns of runoff‐generating areas. The SDDH approach did not correctly capture the timing of runoff from small storms in dry periods. Despite this type of limitation, SDDH‐VSA extends the applicability of the SDDH technique to VSA conditions, providing a basis for new tools to help identify critical management areas and assess water quality risks due to landscape alterations.  相似文献   
109.
The genetic composition and diversity of Plantago lanceolata L. populations were analysed using amplified fragment length polymorphism (AFLP) as well as simple sequence repeat (SSR) markers to test for differences in an old semi-natural grassland after five years of treatment with ambient or elevated ozone (O3) using a free-air fumigation system. Genetic diversity in populations exposed to elevated O3 was slightly higher than in populations sampled from control plots. This effect was significant for AFLP-based measures of diversity and for SSR markers based on observed heterozygosity. Also, a small but significant difference in genetic composition between O3 treatments was detected by analysis of molecular variance and redundancy analysis. The results show that micro-evolutionary processes could take place in response to long-term elevated O3 exposure in highly diverse populations of outbreeding plant species.  相似文献   
110.
Coupled human and natural systems   总被引:18,自引:0,他引:18  
Humans have continuously interacted with natural systems, resulting in the formation and development of coupled human and natural systems (CHANS). Recent studies reveal the complexity of organizational, spatial, and temporal couplings of CHANS. These couplings have evolved from direct to more indirect interactions, from adjacent to more distant linkages, from local to global scales, and from simple to complex patterns and processes. Untangling complexities, such as reciprocal effects and emergent properties, can lead to novel scientific discoveries and is essential to developing effective policies for ecological and socioeconomic sustainability. Opportunities for truly integrating various disciplines are emerging to address fundamental questions about CHANS and meet society's unprecedented challenges.  相似文献   
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