1,667 research outputs found
Oxygen-limited thermal tolerance is seen in a plastron-breathing insect and can be induced in a bimodal gas exchanger.
Thermal tolerance has been hypothesized to result from a mismatch between oxygen supply and demand. However, the generality of this hypothesis has been challenged by studies on various animal groups, including air-breathing adult insects. Recently, comparisons across taxa have suggested that differences in gas exchange mechanisms could reconcile the discrepancies found in previous studies. Here, we test this suggestion by comparing the behaviour of related insect taxa with different gas exchange mechanisms, with and without access to air. We demonstrate oxygen-limited thermal tolerance in air-breathing adults of the plastron-exchanging water bug Aphelocheirus aestivalis. Ilyocoris cimicoides, a related, bimodal gas exchanger, did not exhibit such oxygen-limited thermal tolerance and relied increasingly on aerial gas exchange with warming. Intriguingly, however, when denied access to air, oxygen-limited thermal tolerance could also be induced in this species. Patterns in oxygen-limited thermal tolerance were found to be consistent across life-history stages in these insects, with nymphs employing the same gas exchange mechanisms as adults. These results advance our understanding of oxygen limitation at high temperatures; differences in the degree of respiratory control appear to modulate the importance of oxygen in setting tolerance limits
Non-Markovian non-stationary completely positive open quantum system dynamics
By modeling the interaction of a system with an environment through a renewal
approach, we demonstrate that completely positive non-Markovian dynamics may
develop some unexplored non-standard statistical properties. The renewal
approach is defined by a set of disruptive events, consisting in the action of
a completely positive superoperator over the system density matrix. The random
time intervals between events are described by an arbitrary waiting-time
distribution. We show that, in contrast to the Markovian case, if one performs
a system-preparation (measurement) at an arbitrary time, the subsequent
evolution of the density matrix evolution is modified. The non-stationary
character refers to the absence of an asymptotic master equation even when the
preparation is performed at arbitrary long times. In spite of this property, we
demonstrate that operator expectation values and operators correlations have
the same dynamical structure, establishing the validity of a non-stationary
quantum regression hypothesis. The non-stationary property of the dynamic is
also analyzed through the response of the system to an external weak
perturbation.Comment: 13 pages, 3 figure
Een methodologische vergelijking: De Likert-, en de semantische differentiaal meettechniek toegepast op etnocentrische attitudes
Contains fulltext :
3311.pdf (publisher's version ) (Open Access
CdSe/CdS dot-in-rods nanocrystals fast blinking dynamics
The blinking dynamics of colloidal core-shell CdSe/CdS dot-in-rods is studied
in detail at the single particle level. Analyzing the autocorrelation function
of the fluorescence intensity, we demonstrate that these nanoemitters are
characterized by a short value of the mean duration of bright periods (ten to a
few hundreds of microseconds). The comparison of the results obtained for
samples with different geometries shows that not only the shell thickness is
crucial but also the shape of the dot- in-rods. Increasing the shell aspect
ratio results in shorter bright periods suggesting that surface traps impact
the stability of the fluorescence intensity
Systematic design of market-based balancing arrangements for deregulated power systems: An asynchronous solution
In the deregulated electrical energy market, network operators have to provide market participants with appropriate incentives to guarantee stable operation of the power grid. We demonstrate that the current synchronous energy-based market and incentive system do not necessarily induce power exchange profiles that contribute to grid stability and security of supply. State-of-the-art solutions for tackling the inconsistency between energy-based market mechanisms and power-related balancing objectives can decrease freedom of trade or increase market complexity. This paper provides an alternative scheduling concept as a means to overcome this issue, which relies on asynchronous settlement of energy transactions. We show that in this way, grid operation can become more robust and the strain on balancing reserves can be reduced considerably
Simple model for the power-law blinking of single semiconductor nanocrystals
We assign the blinking of nanocrystals to electron tunneling towards a uniform spatial distribution of traps. This naturally explains the power-law distribution of off times, and the power-law correlation function we measured on uncapped CdS dots. Capped dots, on the other hand, present extended on times leading to a radically different correlation function. This is readily described in our model by involving two different, dark and bright, charged states. Coulomb blockade prevents further ionization of the charged dot, thus giving rise to long, power-law distributed off and on times
Preadvies beekdallandschappen : knelpunten, kennislacunes en kennisvragen voor natuurherstel in beekdalen
Dit preadvies is onder begeleiding van het OBN deskundigenteam beekdallandschappen opgesteld door een groep deskundigen afkomstig van KWR, Alterra, B-WARE, Stichting Bargerveen en Vlinderstichting. Het rapport bevat tevens achtergronddocumentatie betreffende: hydrologie, processen in beken, stofstromen en stofregulatie, bodemvorming, dispersie van soorten en klimaatsverandering. Speciale aandacht wordt gegeven aan dagvlinders, libellen, beekvissen en beekdalmacrofaun
The generality of changes in the trait composition of fish and invertebrate communities after flow restoration in a large river (French Rhône)
1. A multiple-trait-based approach can provide predictions and interpretations of the responses of freshwater communities to river restoration that apply in different taxonomic contexts. We compared the observed and predicted effects of restoration on sets of traits in fish and invertebrate communities in four reaches of the Rhône River. Restoration included minimum flow increases in three bypassed main channels and the reconnection of eight floodplain channels. 2. Predictions (described in detail in three other articles in this Special Issue) were based on habitat models that related the density of modelled taxa to their physical habitats. We used trait information extracted from the literature to translate predicted taxonomic changes into predicted changes in traits. Observed changes in traits calculated for modelled taxa and for all taxa in the community were both compared to predictions. 3. In 10 of 12 cases, observed changes in traits correlated with predicted ones. With few exceptions, the agreement was higher for fish and invertebrates in the main channels than for invertebrates in floodplain channels. Predictions translated to the trait category level improved those at the taxonomic level in 5/6 and 4/6 cases for modelled taxa and all taxa, respectively. However, the improvement was statistically significant according to a null model for 1/6 and 3/6 cases for modelled taxa and all taxa, respectively. 4. The validation of trait predictions suggested that traits related to locomotion and attachment, as well as general biology and physiology, were particularly suited to predicting and understanding the effects of physical restoration. For example, after restoration, clingers and passive filter feeders dominated invertebrate communities in the main channels, whereas invertebrate communities in the floodplain underwent a selection of traits frequent in running water (clingers, flattened shape and gill respiration). Within fish communities, the periodic life-history strategy that characterises fish species in downstream reaches (long life span, large body, late sexual maturity) increased with restoration, whereas the opportunistic strategy decreased. 5. Our results suggest that a better understanding of how hydraulics shapes traits in riverine systems is critically needed for assessing the effects of restoration measures impacting flow. In addition, existing trait databases (especially for fish) should be expanded to better reflect the energetic trade-offs that organisms must make in various flow contexts
Вплив структури фонових знань перекладача на інтерпретацію міфологічних алюзій
L.M.Chernovaty, T.K.Varenko. An impact of the interpreters’ background knowledge structure upon their interpretation of mythological allusions. Basing upon an experimental research into the ways English sentences containing mythology-related allusions are interpreted into Ukrainian, the author argues for the necessity to include the corresponding elements into the subject-matter of the interpreter-training course to provide for the acquisition of background knowledge in mythology and folklore related to the cultures contacting in the process of interpreting.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/1128
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