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81.
Marc Gracia Nacima Meghelli Lluís Comas Javier Retana 《Regional Environmental Change》2011,11(2):349-358
The current state of Mediterranean mountain areas has been driven by two main factors: intense traditional human activity
and the dynamics of the ecosystem itself. In this study, we examine land-cover changes in a National Park in the Pyrenees
mountains (NE Iberian Peninsula), which was designated a protected area 55 years ago. First, we have analyzed spatio-temporal
changes in land-cover pattern and forest dynamics from 1957 to 2005. During this period, land-cover dynamics consisted of
two main processes: (i) expansion of the forest area and (ii) increasing cover of forests already present in 1957. To analyze
the role of the conservation level of the park, we have also compared the results obtained within the park with those of unprotected,
peripheral areas. In the two areas with different protection level, dense forests increased throughout the period because
of the reduction in forestry activities. The peripheral area showed a higher rate of forest-cover change from 1957 to 2005
compared to the National Park. This higher increase in forest cover in the peripheral area could be related to a higher proportion
in the National Park of screes and rocky areas and to the decline and transformation of forest activities in these peripheral,
lower elevation areas. 相似文献
82.
83.
The activity of 210Po and 210Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759 ± 277 Bq kg−1 for 210Po (range 460-1470 Bq kg−1 dry weight), and 45 ± 19 Bq kg−1 for 210Pb (range 23-96 Bq kg−1 dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that 210Po and 210Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210 ± 75 Bq kg−1 (dry weight) for 210Po and 10 ± 4 Bq kg−1 (dry weight) for 210Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of 210Po and man-made contaminants measured in mussels far from pollution sources. 相似文献
84.
85.
Zandra C. Deans Anil Biricik Martine De Rycke Gary L. Harton Miroslav Hornak Farrah Khawaja Céline Moutou Jan Traeger-Synodinos Pamela Renwick 《黑龙江环境通报》2023,43(4):506-515
Objective
Genomics Quality Assessment has provided external quality assessments (EQAs) for preimplantation genetic testing (PGT) for 12 years for eight monogenic diseases to identify sub-optimal PGT strategies, testing and reporting of results, which can be shared with the genomics community to aid optimised standards of PGT services for couples.Method
The EQAs were provided in two stages to mimic end-to-end protocols. Stage 1 involved DNA feasibility testing of a couple undergoing PGT and affected proband. Participants were required to report genotyping results and outline their embryo testing strategy. Lymphoblasts were distributed for mock embryo testing for stage 2. Submitted clinical reports and haplotyping results were assessed against peer-ratified criteria. Performance was monitored to identify poor performance.Results
The most common testing methodology was short tandem repeat linkage analysis (59%); however, the adoption of single nucleotide polymorphism-based platforms was observed and a move from blastomere to trophectoderm testing. There was a variation in testing strategies, assigning marker informativity and understanding test limitations, some clinically unsafe. Critical errors were reported for genotyping and interpretation.Conclusion
EQA provides an overview of the standard of preimplantation genetic testing-M clinical testing and identifies areas of improvement for accurate detection of high-risk embryos. 相似文献86.
Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its
adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body
condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined
sticklebacks (Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions.
All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition.
Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In
contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is,
to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial
cannibalism. 相似文献
87.
Laura Rodríguez-Loeches Alejandro Barro Martha Pérez Frank Coro 《Die Naturwissenschaften》2009,96(4):531-536
Both sexes of Phoenicoprocta capistrata have functional tymbals. The scanning electron microscopy revealed differences in the morphology of these organs in males
and females. Male tymbals have a well-developed striated band, constituted by 21 ± 2 regularly arranged striae whereas female
tymbals lack a striated band. This type of sexual dimorphism is rare in Arctiidae. The recording of the sound produced by
moths held by the wings revealed that while males produced trains of pulses organized in modulation cycles, females produced
clicks at low repetition rate following very irregular patterns. Statistically, there are differences between sexes in terms
of the duration of pulses, which were 355 ± 24 μs in the case of males and 289 ± 29 μs for females. The spectral characteristics
of the pulses also show sexual dimorphism. Male pulses are more tuned (Q
10 = 5.2 ± 0.5) than female pulses (Q
10 = 2.7 ± 0.5) and have a higher best frequency (42 ± 1 kHz vs. 29 ± 2 kHz). To our knowledge, this is the first report on
an arctiid moth showing sexual dimorphism in tymbal’s anatomy that leads to a best frequency dimorphism. Males produce sound
at mating attempts. The sounds recorded during mating are modulation cycles with the same spectral characteristics as those
recorded when males are held by the wings. The morphological and acoustic features of female tymbals could indicate a process
of degeneration and adaptation to conditions under which the emission of complex patterns is not necessary.
Frank Coro no longer works at Universidad de La Habana. 相似文献
88.
Alexander Golub Jos Cozijnsen Annie Petsonk 《Mitigation and Adaptation Strategies for Global Change》2009,14(5):433-453
This article examines possibilities for linkage between the European Union Emissions Trading System (EU ETS) and Russia, with
a view to enhancing cooperation on a broader scale than the project-based approaches that have been tested thus far. Three
paths for possible EU-Russia linkage are presented by which the Russian Assigned Amount under the Kyoto Protocol can be greened
in order to stimulate emissions trading: 1. Joint implementation—reductions earned via individual projects in Russia; 2. Greened
allowances or green investment schemes; and 3. Linked cap-and-trade systems, in which a Russian domestic emissions trading
system would link with the European Union Emissions Trading System. The authors conclude that the third option, emissions
trading through linked domestic emissions trading systems, offers the best opportunities at the lowest transaction costs.
The authors discuss useful innovative instruments like call options and slip level arrangements on government-to-government
and business-to-business levels.
相似文献
Annie PetsonkEmail: |
89.
Johannes Kroiss Erhard Strohm Cédric Vandenbem Jean-Pol Vigneron 《Die Naturwissenschaften》2009,96(8):983-986
Chrysidid wasps in the subfamily Chrysidinae are brood parasitoids or cleptoparasites of other insects and famous for their
cuticular iridescence. In this study, we examine the dorsal abdominal cuticle of the chrysidid wasp Hedychrum rutilans to identify the underlying color mechanism. Using scanning electron microscopy, reflectance spectral analysis, and theoretical
calculations, we demonstrate the presence of an epicuticular multilayer reflector consisting of six lamellae with a thickness
of 185 nm each. The lamellae exhibit a rough surface probably functioning as spacers between the individual layers. The reflector
has a measured reflectance maximum at λ = 630 nm, i.e., in the red part of the visible spectrum of light at normal incidence and the reflectance maximum shifts to
green as the angle of incidence increases. Complementary theoretical modeling corroborates the view that the epicuticular
multilayer generates the iridescent color of the chrysidid cuticle.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
90.
Fabian Engel Kaitlin J. Farrell Ian M. McCullough Facundo Scordo Blaize A. Denfeld Hilary A. Dugan Elvira de Eyto Paul C. Hanson Ryan P. McClure Peeter Nõges Tiina Nõges Elizabeth Ryder Kathleen C. Weathers Gesa A. Weyhenmeyer 《Die Naturwissenschaften》2018,105(3-4):25
The magnitude of lateral dissolved inorganic carbon (DIC) export from terrestrial ecosystems to inland waters strongly influences the estimate of the global terrestrial carbon dioxide (CO2) sink. At present, no reliable number of this export is available, and the few studies estimating the lateral DIC export assume that all lakes on Earth function similarly. However, lakes can function along a continuum from passive carbon transporters (passive open channels) to highly active carbon transformers with efficient in-lake CO2 production and loss. We developed and applied a conceptual model to demonstrate how the assumed function of lakes in carbon cycling can affect calculations of the global lateral DIC export from terrestrial ecosystems to inland waters. Using global data on in-lake CO2 production by mineralization as well as CO2 loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of \( {0.70}_{-0.31}^{+0.27} \) to \( {1.52}_{-0.90}^{+1.09} \) Pg C yr?1 depending on the assumed function of lakes. Thus, the considered lake function has a large effect on the calculated lateral DIC export from terrestrial ecosystems to inland waters. We conclude that more robust estimates of CO2 sinks and sources will require the classification of lakes into their predominant function. This functional lake classification concept becomes particularly important for the estimation of future CO2 sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change. 相似文献