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Edoardo Mazza Miguel Parra-Saavedra Michael Bajka Eduard Gratacos Kypros Nicolaides Jan Deprest 《黑龙江环境通报》2014,34(1):33-41
Measuring the stiffness of the cervix might be useful in the prediction of preterm delivery or successful induction of labor. For that purpose, a variety of methods for quantitative determination of physical properties of the pregnant cervix have been developed. Herein, we review studies on the clinical application of these new techniques. They are based on the quantification of mechanical, optical, or electrical properties associated with increased hydration and loss of organization in collagen structure. Quasi-static elastography determines relative values of stiffness; hence, it can identify differences in deformability. Quasi-static elastography unfortunately cannot quantify in absolute terms the stiffness of the cervix. Also, the current clinical studies did not demonstrate the ability to predict the time point of delivery. In contrast, measurement of maximum deformability of the cervix (e.g. quantified with the cervical consistency index) provided meaningful results, showing an increase in compliance with gestational age. These findings are consistent with aspiration measurements on the pregnant ectocervix, indicating a progressive decrease of stiffness along gestation. Cervical consistency index and aspiration measurements therefore represent promising techniques for quantitative assessment of the biomechanical properties of the cervix. © 2013 John Wiley & Sons, Ltd. 相似文献
23.
David D. Cohen Jagoda Crawford Eduard Stelcer Vuong Thu Bac 《Atmospheric environment (Oxford, England : 1994)》2010,44(31):3761-3769
Fine particulate matter (PM2.5), source fingerprints and their contributions have been measured and reported previously at Hanoi, Vietnam, from 25 April 2001 to 31 December 2008. In this study back trajectories are used to identify long range transport into Hanoi for two of these sources, namely, windblown dust (Soil) from 12 major deserts in China and emissions from 33 coal fired power plants (Coal) in Vietnam and China. There were 28 days of extreme Soil events with concentrations greater than 6 μg m?3 and 25 days of extreme Coal with concentrations greater than 30 μg m?3 from a total of 748 sampling days during the study period. Through the use of back trajectories it was found that long range transport of soil from the Taklamakan and Gobi desert regions (more than 3000 km to the north west) accounted for 76% of the extreme events for Soil. The three local Vietnamese power stations contributed to 15% of the extreme Coal events, while four Chinese power stations between 300 km and 1700 km to the north-east of Hanoi contributed 50% of the total extreme Coal events measured at the Hanoi sampling site. 相似文献
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Ivonne?MeucheEmail author K.?Eduard?Linsenmair Heike?Pr?hl 《Behavioral ecology and sociobiology》2012,66(4):613-621
In many species male reproductive success is limited by access to females. Territoriality is one behavioural strategy which
helps to acquire females. In the present study, we investigated the correlation between territory size and (1) female availability
and (2) rate of intrusion by conspecific males in strawberry poison frogs, Oophaga pumilio. Males defended smaller territories in areas with a high female density and high rate of intrusion by conspecific males.
Only males with high body condition values were able to establish territories in areas of high female density probably due
to better fighting abilities. Moreover, dominant calling frequency was lower during agonistic interactions. Because only males
with high body condition values were able to produce very low dominant frequencies, the acoustic properties appear to be an
honest signal containing information about fighting abilities. Thus, the negative correlation between dominant frequency and
mating success of males found in previous studies seems to be in part the result of intrasexual competition between males. 相似文献
27.
Contents of phenolic compounds in leaf extracts often serve as a measure of plant anti-herbivore defence. This method suffers from the multifunctionality of phenolics and from problems with their colorimetric quantification. Here we present further evidence for the pertinence of these problems. Contents of condensed tannins (CCT) were spectrophotometrically quantified in leaf extracts of 11 closely related mimosoid species, and Spodoptera littoralis caterpillars were reared on artificial diet containing these extracts. The relationship of CCT with caterpillar growth differed considerably among plant species, since both positive and negative correlations were detected. There was, however, a negative correlation of CCT with fungal spore germination, indicating a role of these compounds in resistance to fungi. Detailed knowledge on the structure and biological function of defensive compounds and on the overall composition of leaves is required to estimate a plant's defensive efficacy against a particular group of enemies. 相似文献
28.
Martin Heil Brigitte Fiala K. Eduard Linsenmair Thomas Boller 《Die Naturwissenschaften》1999,86(3):146-149
Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences
such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences.
Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections
actively in the obligate myrmecophyte Macaranga
triloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition
for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not
only as an antiherbivore defense but also as an effective agent against fungal pathogens.
Received: 5 August 1998 / Accepted in revised form: 18 November 1998 相似文献
29.
Feichtinger Franz Smidt Stefan Klaghofer Eduard 《Environmental science and pollution research international》2002,9(2):31-36
The water balance for the site Mühleggerköpfl in the North Tyrolean Limestone Alps has been established to a soil depth of 50 cm. The evaporation amounts to 42% and deep percolation is 58 % of the precipitation. The surface runoff was negligible and therefore the according nitrate fluxes as well. Soil water analysis revealed mean nitrate concentrations of 3 to 15 mg NO3 L−1, depending on soil depth. The nitrate concentrations at 50 cm soil depth and the associated percolation rates led to NO2 −N outputs of 15.9 kg NO3 −N ha−1 in the year 1999 and 7.9 kg NO3 ∼N ha−1 in the year 2000.
相似文献30.
Frank van der Meulen Bert van der Valk Laurens Baars Eduard Schoor Hans van Woerden 《Journal of Coastal Conservation》2014,18(5):505-513
A new dune area was constructed by beach and foreshore nourishments along the Delfland Coast in the southwestern Netherlands. The new area is intended to be a compensation for losses of existing high quality dunes in nearby areas, due to the use/construction of Maasvlakte 2, the new harbour extension of Rotterdam opening in 2013. The target habitats for compensation include dry grey dunes and moist dune valley grassland. Due to the habitat type, the nourished material had to have a special character. The nourishment was carried out according to a special design and initial development of the new area had to follow certain pathways. In order to meet the compensation requirements in time. Careful monitoring is done to assess whether development of the new habitat is taking place in the direction of the desired target habitats. This paper reports on the construction of the new area and on the first years of development and monitoring. The monitoring mainly concerns development of the abiotic landscape elements, geomorphology, groundwater and soils. The lessons learned from this area are discussed in the light of the development of other recent young nature areas in the sandy Dutch delta coast. This gives new insights for coastal management in general in the context of building with nature. 相似文献