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991.
Public signaling plays an important role in territorial and sexual displays in animals; however, in certain situations, it
is advantageous to keep signaling private to prevent eavesdropping by unintended receivers. In the northeastern Pacific, two
populations of killer whales (Orcinus orca), fish-eating “resident” killer whales and mammal-eating “transient” killer whales, share the same habitat. Previous studies
have shown that residents use whistles as private signals during close-range communication, where they probably serve to coordinate
behavioral interactions. Here, we investigated the whistling behavior of mammal-eating killer whales, and, based on divergent
social structures and social behaviors between residents and transients, we predicted to find differences in both whistle
usage and whistle parameters. Our results show that, like resident killer whales, transients produce both variable and stereotyped
whistles. However, clear differences in whistle parameters between ecotypes show that the whistle repertoire of mammal-eating
killer whales is clearly distinct from and less complex than that of fish-eating killer whales. Furthermore, mammal-eating
killer whales only produce whistles during “milling after kill” and “surface-active” behaviors, but are almost completely
silent during all other activities. Nonetheless, whistles of transient killer whales may still serve a role similar to that
of resident killer whales. Mammal-eating killer whales seem to be under strong selection to keep their communication private
from potential prey (whose hearing ranges overlap with that of killer whales), and they appear to accomplish this mainly by
restricting vocal activity rather than by changes in whistle parameters. 相似文献
992.
Colby J. Tanner Gül Deniz Salalι Andrew L. Jackson 《Behavioral ecology and sociobiology》2011,65(2):249-256
Human activity can have a large impact on surrounding ecosystems. For example, humans alter resource distributions for other
species, potentially modifying these species competitive dynamics. These changes in local competitive processes are frequently
associated with species invasions. Here, we investigate how differences in resource distribution affect competitive behaviour
using the highly invasive European shore crab (Carcinus maenas). Using a controlled laboratory experiment in combination with behaviour assays and social network analysis, we show that
individuals feeding in habitats with clumped food distributions are more aggressive than individuals feeding in habitats where
food is evenly dispersed, and this aggression is present even on days where crabs are not feeding. Additionally, this persistent
aggression can be induced, suggesting that individuals of this invasive species possess the flexibility to modify their competitive
behaviours in response to differences in food distributions. Furthermore, we show how these individual responses can lead
to changes in overall organisation of aggressive interactions within a population. We discuss these results in relation to
how human impacts can have long-term effects on competitive behavioural strategies, and how behavioural flexibility can allow
invasive species to colonise and persist in highly impacted sites such as urban ecosystems. 相似文献
993.
Jelle S. van Zweden Christoph Grüter Sam M. Jones Francis L.W. Ratnieks 《Behavioral ecology and sociobiology》2011,65(6):1277-1282
Social insects need to defend their nest against robbery, parasitism and predation. The stingless bee Tetragonisca angustula is unique in that it has guards that hover near the nest entrance in addition to guards that stand at the entrance. We tested
both the general hypothesis that hovering guards increase the effectiveness with which flying intruders are detected and the
specific hypothesis that hovering guards improve the detection of workers of the obligate robber bee, Lestrimellita limao. In an intraspecific study comparing colonies, we found a strong positive relationship between the number of hovering guards
and the distance at which a dummy robber bee or L. limao worker, experimentally moved towards the nest entrance, was detected. These results were mirrored in an interspecific study
showing that four species of stingless bees with similar population colonies but which lacked hovering guards, detected L. limao only at the nest entrance, in contrast to T. angustula. In addition, we found that a greater number of attacks by guards occurred when dummies were impregnated with citral, a major
component of L. limao mandibular gland odour. Our results support the hypothesis that T. angustula hovering guards increase the detection perimeter for flying intruders, especially L. limao. 相似文献
994.
995.
The present paper outlines potential shortcomings of analyzing events in high hazard systems. We argue that the efficiency of organizational learning within high hazard systems is at least partially undermined by the subjective theories of organizing held by their members. These subjective theories basically reflect an “engineering” understanding of “how a system and its components perform”, and are assumed to involve (social-) psychological blind spots when applied to the analysis of events. More specifically, we argue that they neglect individual motives and goals that critically drive work performance and social interactions in high hazard systems. First, we focus on the process of identifying the causes of failed organizing within the course of an event analysis. Our analysis reveals a mismatch between the basic functional assumptions of the event analyst on the motives of social actors involved in an event and on the other hand, the perspective held by the social actors themselves. Second, we discuss the process of correcting failed social system performance after events. Thereby we draw on blind spots that emerge from the direct application of technical safety principles (i.e., standardization and redundancy) to the organization of social systems. Finally, we propose some future research strategies for developing event analysis methods which are aimed at improving an organization’s learning potential. 相似文献
996.
Scheurer M Storck FR Graf C Brauch HJ Ruck W Lev O Lange FT 《Journal of environmental monitoring : JEM》2011,13(4):966-973
Six trace contaminants (acesulfame (ACE), sucralose (SUC), carbamazepine (CBZ), diatrizoic acid (DTA), 1H-benzotriazole (BTZ) and its 4-methyl analogue (4-TTri)) were traced from wastewater treatment plants (WWTPs) to receiving waters and further to riverbank filtration (RBF) wells to evaluate their prediction power as potential wastewater markers. Furthermore, the persistence of some compounds was investigated in advanced wastewater treatment by soil aquifer treatment (SAT). During wastewater treatment in four conventional activated sludge WWTPs ACE, SUC, and CBZ showed a pronounced stability expressed by stable concentration ratios in influent (in) and effluent (out) (ACE/CBZ: in45, out40; SUC/CBZ: in1.8, out1.7; and ACE/SUC: in24, out24). In a fifth WWTP, additional treatment with powdered activated carbon led to a strong elimination of CBZ, BTZ, and 4-TTri of about 80% and consequently to a distinctive shift of their ratios with unaffected compounds. Data from a seven month monitoring program at seven sampling locations at the rivers Rhine and Main in Germany revealed the best concentration correlation for ACE and CBZ (r(2) = 0.94) and also a good correlation of ACE and CBZ concentrations to BTZ and 4-TTri levels (r(2) = 0.66 to 0.82). The comparison of ratios at different sampling sites allowed for the identification of a CBZ point source. Furthermore, in Switzerland a higher consumption of SUC compared to Germany can be assumed, as a steadily increasing ACE/SUC ratio along the river Rhine was observed. In RBF wells a good correlation (r(2) = 0.85) was again observed for ACE and CBZ. Both also showed the highest stability at a prolonged residence time in the subsurface of a SAT field. In the most peripheral wells ACE and CBZ were still detected with mean values higher than 36 μg L(-1) and 1.3 μg L(-1), respectively. Although SUC concentrations in wastewater used for SAT decreased by more than 80% from about 18 μg L(-1) to 2.1 μg L(-1) and 3.5 μg L(-1) in these outlying wells, the compound was still adequate to indicate a wastewater impact in a qualitative way. 相似文献
997.
Occurrence and distribution of organophosphorus flame retardants and plasticizers in anthropogenically affected groundwater 总被引:1,自引:0,他引:1
Regnery J Püttmann W Merz C Berthold G 《Journal of environmental monitoring : JEM》2011,13(2):347-354
Occurrence and distribution of chlorinated and non-chlorinated organophosphates in 72 groundwater samples from Germany under different recharge/infiltration conditions were investigated. Tris(2-chloro-1-methylethyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) were the most frequently detected organophosphates in groundwater samples. Highest individual organophosphate concentrations (>0.1 μg L(-1)) were determined in groundwater polluted by infiltrating leachate and groundwater recharged via riverbank filtration of organophosphate-loaded recipients. In samples from springs and deep groundwater monitoring wells that are not affected by surface waters, organophosphate concentrations were mostly below the limit of detection. The occurrence (3-9 ng L(-1)) of TCPP and TCEP in samples from aquifers with groundwater ages between 20 and 45 years indicates the persistence of both compounds within the aquifer. At urban sites organophosphate-loaded precipitation, surface runoff, and leakage of wastewater influenced groundwater quality. For rural sites, where groundwater recharge is only influenced by precipitation, organophosphates were very rarely detectable in groundwater. 相似文献
998.
Ivonne Bedei Karl-Philipp Gloning Luc Joyeux Matthias Meyer-Wittkopf Daria Willner Martin Krapp Alexander Scharf Jan Degenhardt Kai-Sven Heling Peter Kozlowski Kathrin Trautmann Kai M. Jahns Annegret Geipel Ismail Tekesin Michael Elsässer Lucas Wilhelm Ingo Gottschalk Jan-Erik Baumüller Cahit Birdir Andreas Schröer Felix Zöllner Aline Wolter Johanna Schenk Tascha Gehrke Alicia Spaeth Roland Axt-Fliedner 《黑龙江环境通报》2023,43(2):183-191
Objective
Omphalocele is known to be associated with genetic anomalies like trisomy 13, 18 and Beckwith–Wiedemann syndrome, but not with Turner syndrome (TS). Our aim was to assess the incidence of omphalocele in fetuses with TS, the phenotype of this association with other anomalies, their karyotype, and the fetal outcomes.Method
Retrospective multicenter study of fetuses with confirmed diagnosis of TS. Data were extracted from a detailed questionnaire sent to specialists in prenatal ultrasound.Results
680 fetuses with TS were included in this analysis. Incidence of small omphalocele in fetuses diagnosed ≥12 weeks was 3.1%. Including fetuses diagnosed before 12 weeks, it was 5.1%. 97.1% (34/35) of the affected fetuses had one or more associated anomalies including increased nuchal translucency (≥3 mm) and/or cystic hygroma (94.3%), hydrops/skin edema (71.1%), and cardiac anomalies (40%). The karyotype was 45,X in all fetuses. Fetal outcomes were poor with only 1 fetus born alive.Conclusion
TS with 45,X karyotype but not with X chromosome variants is associated with small omphalocele. Most of these fetuses have associated anomalies and a poor prognosis. Our data suggest an association of TS with omphalocele, which is evident from the first trimester. 相似文献999.
Objective
To examine the impact of the fetal fraction (FF) on the screen-positive rate in screening for microdeletion 22q11.2.Methods
This study is based on samples that were analyzed using the Harmony® Prenatal Test (Roche Inc). The study cohort comprised samples from women with singleton pregnancies who were at least 16 years old and at least at 11 weeks' gestation. Logistic regression analysis was used to determine significant covariates that carry an impact on the screen-positive rate.Results
The study population consisted of 52,019 pregnancies, including 309 pregnancies with a high-risk result for microdeletion 22q11.2. Thus, the overall screen-positive rate was 0.59%. In the low-risk group, the FF was 10.1%, and in the high-risk group, it was 7.3%. Regression analysis indicated a strong correlation between the FF and the screen-positive rate. In the cases with an FF of <11.0%, the screen-positive rate was 0.92%, while it was 0.13% in the group with a higher FF.Conclusion
The screen-positive rate depends on the FF. In order to keep the rate low, we recommend restricting the analysis to samples with a FF of 11% and more. 相似文献1000.
Permeable biobarrier systems (PBSs) are being recognized as low‐cost passive bioremediation technologies for chlorinated organic contamination. This innovative technology can play a crucial and effective role in site restorations. Laboratory‐scale experiments were conducted to investigate the biodegradation of trichloroethylene (TCE) to ethylene in shallow groundwater through the use of a PBS enhanced by bioaugmentation at the U.S. Department of Energy's Savannah River Site (SRS). Two composts and two plant amendments, eucalyptus mulch (EM) and corncobs (CC), were examined for their effectiveness at creating and maintaining conditions suitable for TCE anaerobic dechlorination. These materials were evaluated for their (1) nutrient and organic carbon content, (2) TCE sorption characteristics, and (3) longevity of release of nutrients and soluble carbon in groundwater to support TCE dechlorination. Native bacteria in the columns had the ability to convert TCE to dichloroethenes (DCEs); however, the inoculation with the TCE‐degrading culture greatly increased the rate of biodegradation. This caused a significant increase in by‐product concentration, mostly in the form of DCEs and vinyl chloride (VC) followed by a slow degradation to ethylene. Of the tested amendments, eucalyptus mulch was the most effective at supporting the reductive dechlorination of TCE. Corncobs created a very acidic condition in the column that inhibited dechlorination. © 2007 Wiley Periodicals, Inc. 相似文献