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141.
Signe Brinkløv Elisabeth K. V. Kalko Annemarie Surlykke 《Behavioral ecology and sociobiology》2010,64(11):1867-1874
Echolocating bats adjust the time–frequency structure such as sweep rate and pulse interval of their sonar calls when they
move from open space to vegetation-dense environments. Emitted call intensity is equally important for echolocation, but adjustment
of signal intensity to different habitats has never been systematically studied in any bat species. To address this question,
we recorded sonar calls of the Neotropical trawling insectivorous bat Macrophyllum macrophyllum (Phyllostomidae) at three sites with different obstacle densities (clutter). We found a clear correlation between emitted
intensity and degree of clutter, with intensity proportional to decreasing clutter. In highly cluttered, semicluttered, and
open spaces, M. macrophyllum emitted calls with mean source levels (sound pressure level (SPL) 10 cm from the bat’s mouth) of 100, 105, and 111 dB SPL
root mean square (rms), respectively. To our knowledge, this is the first documentation of dynamic intensity adjustments in
bats. Phyllostomid bats were previously considered silent, but the 111-dB SPL rms emitted by free-ranging M. macrophyllum in open space is comparable to output in aerial insectivorous bats from other families. Our results suggest that the acoustic
constraints of habitats are better predictors of call intensity than phylogeny and therefore likely to be major drivers shaping
the sonar system of bats in the course of evolution. 相似文献
142.
Increasingly, citizens are being asked to take a more active role in disaster risk reduction (DRR), as decentralization of hazard governance has shifted greater responsibility for hazard preparedness actions onto individuals. Simultaneously, the taxonomy of hazards considered for DRR has expanded to include medical and social crises alongside natural hazards. Risk perception research emerged to support decision-makers with understanding how people characterize and evaluate different hazards to anticipate behavioral response and guide risk communication. Since its inception, the risk perception concept has been incorporated into many behavioral theories, which have been applied to examine preparedness for numerous hazard types. Behavioral theories have had moderate success in predicting or explaining preparedness behaviors; however, they are typically applied to a single hazard type and there is a gap in understanding which theories (if any) are suited for examining multiple hazard types simultaneously. This paper first reviews meta-analyses of behavioral theories to better understand performance. Universal lessons learnt are summarized for survey design. Second, theoretically based preparedness studies for floods, earthquakes, epidemics, and terrorism are reviewed to assess the conceptual requirements for a ‘multi-hazard’ preparedness approach. The development of an online preparedness self-assessment and learning platform is discussed. 相似文献
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145.
Jan S. Erkamp Vincent W.V. Jaddoe Liesbeth Duijts Irwin K.M. Reiss Annemarie G.M.G.J. Mulders Eric A.P. Steegers Romy Gaillard 《黑龙江环境通报》2020,40(6):746-757
Objective
To determine screening performance of maternal, fetal and placental characteristics for selecting pregnancies at risk of gestational hypertension and preeclampsia in a low-risk multi-ethnic population.Method
In a prospective population-based cohort among 7124 pregnant women, we collected maternal characteristics including body mass index, ethnicity, parity, smoking and blood pressure in early-pregnancy. Fetal characteristics included second and third trimester estimated fetal weight and sex determined by ultrasound. Placental characteristics included first and second trimester placental growth factor concentrations and second and third trimester uterine artery resistance indices.Results
Maternal characteristics provided the best screening result for gestational hypertension (area-under-the-curve [AUC] 0.79 [95% Confidence interval {CI} 0.76-0.81]) with 40% sensitivity at 90% specificity. For preeclampsia, the maternal characteristics model led to a screening performance of AUC 0.74 (95% CI 0.70-0.78) with 33% sensitivity at 90% specificity. Addition of second and third trimester placental ultrasound characteristics only improved screening performance for preeclampsia (AUC 0.78 [95% CI 0.75-0.82], with 48% sensitivity at 90% specificity).Conclusion
Routinely measured maternal characteristics, known at the start of pregnancy, can be used in screening for pregnancies at risk of gestational hypertension or preeclampsia within a low-risk multi-ethnic population. Addition of combined second and third trimester placental ultrasound characteristics only improved screening for preeclampsia.146.
Günther A. Wagner 《Die Naturwissenschaften》1980,67(5):216-226
Only relatively few laboratories are actively engaged in thermoluminescence-dating of rocks and artifacts. Nearly all these laboratories combine the practical application with methodical developments, because thermoluminescence-dating is too complex in order to become a routine method in the near future. This article reviews the principles and new developments and the archaeological and geological applications of thermoluminescence-dating. 相似文献
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The Science of Nature - 相似文献
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