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31.
32.
Ross A. Robinson Samuel C. Griffiths Lieke L. van de Haar Tomas Malinauskas Eljo Y. van Battum Pavol Zelina Rebekka A. Schwab Dimple Karia Lina Malinauskaite Sara Brignani Marleen H. van den Munkhof Özge Düdükcü Anna A. De Ruiter Dianne M.A. Van den Heuvel Benjamin Bishop Jonathan Elegheert A. Radu Aricescu R. Jeroen Pasterkamp Christian Siebold 《Cell》2021,184(8):2103-2120.e31
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34.
《Critical reviews in biotechnology》2013,33(4):337-353
Recent advances in the convergence of the biological, chemical, physical, and engineering sciences have opened new avenues of research into the interfacing of diverse biological moieties with inanimate platforms. A main aspect of this field, the integration of live cells with micro-machined platforms for high throughput and bio-sensing applications, is the subject of the present review. These unique hybrid systems are configured in a manner that ensures positioning of the cells in designated patterns, and enables cellular viability maintenance, and monitoring of cellular functionality. Here we review both animate and inanimate surface properties and how they affect cellular attachment, describe relevant modifications of both types of surfaces, list technologies for platform engineering and for cell deposition in the desired configurations, and discuss the influence of various deposition and immobilization methods on the viability and performance of the immobilized cells. 相似文献
35.
Abstract. The ecological roles of small (1–1000 mg) predators in benthic marine systems are poorly understood. We investigated the natural history and predatory impact of one group of such mesopredators—larvae of dipteran flies in the genus Oedoparena —which prey on intertidal barnacles. We 1) quantified patterns of larval Oedoparena distribution and abundance in the Northwest Straits of Washington State, USA, 2) determined larval physiological tolerance limits in the laboratory, and 3) conducted a manipulative field experiment to assess the role of microhabitat temperature on predation rates in Oedoparena . Members of Oedoparena in Washington are univoltine, with peak larval abundance in late spring and early summer. Infestation frequencies in the barnacles Balanus glandula and Chthamalus dalli were as high as 22% and 35%, respectively. In laboratory studies, larvae of O . glauca were able to tolerate temperatures up to 37°C; however, this temperature is often exceeded in high intertidal habitats. In a field manipulation using experimental shades, we demonstrate that the alleviation of physiological stress greatly increased the abundance of larvae of Oedoparena spp. As a result of increased larval densities under shades, adult B. glandula mortality increased from 5% to nearly 30%, and C. dalli mortality increased from less than 20% to over 60%. Because high intertidal barnacles serve as food and habitat for a diverse array of species, Oedoparena spp. have the potential to play a major role in structuring high intertidal communities, particularly in cooler microhabitats. 相似文献
36.
The life-cycle of the ancient asexual ostracod Darwinula stevensoni was studied during 1 year in a eutrophic pond in Belgium. The reproductive period of this species started in March and was effectively completed by September of the same year. All changes in population structure took place during the spring and summer months and a rapid turnover of the instars was observed. The life-cycle of Darwinula stevensoni appears to take one year or less in Belgium and this is considerably shorter than the 4 years which had been reported previously from subarctic populations. The difference to the present study is most likely temperature-related. Maximal densities of D. stevensoni were observed in June and July and attained 105 ind. m–2. During winter, densities were lower with a mean of 104 ind. m–2. Consequently, the calculated population size of each month was high throughout the year. Together with the low mutation rate, such a large population size could effectively counteract the stochastic loss of mutation-free genotypes as predicted by Muller's ratchet. D. stevensoni is a brooder; the maximum number of embryos and juvenile instars (up to third stage) found within a single female was 11. 相似文献
37.
Effects of ambient temperature on avian incubation behavior 总被引:6,自引:1,他引:5
Ambient temperature is commonly thought to influence avian incubation
behavior. However, results of empirical studies examining correlationsbetween ambient temperature and bout duration are equivocal.We propose that these equivocal results can be partly explainedby developing a conceptual understanding of how we should expecttemperature to influence incubation. We demonstrate why linearcorrelation analyses across a wide range of temperatures canbe inappropriate based on development of an incubation model
for small birds that incorporates how ambient temperature influencesboth embryonic development and adult metabolism. We found supportfor predictions of the model using incubation data from orange-crownedwarblers (Vermivora celata) in Arizona. Both off- and on-boutduration were positively correlated with ambient temperaturebetween 9° and 26°C, but unrelated to ambient temperature<9° and 26-40°C. Bout durations declined as ambienttemperature approached or exceeded 40°C. Incubating orange-crowned
warblers appeared to avoid bouts off the nest <7 min andbouts on the nest <20 min. Time of day, duration of theprevious bout, and variation among nests all explained variationin both on- and off-bout duration. Although we found supportfor the general shape of the incubation model, temperature still
explained only a small portion of the overall variation in on-and off-bout duration. Results of previous studies were generallyconsistent with the model for off-bout duration; most studiesin colder environments reported positive correlations withtemperature, and the one negative correlation reported was
from a hot environment. However, the relationships between on-boutduration and temperature reported in previous studies wereless consistent with our model and our data. Although somediscrepancies could be explained by considering our model,some studies reported negative correlations in cold environments.The effect of ambient temperature on duration of on-bouts probablydiffers among species based on the amount of fat reserves females
typically carry during incubation and the extent of male incubationfeeding. Additional studies of the effects of temperature onavian incubation will help improve the general model and ultimatelyaid our understanding of energetic and ecological constraintson avian incubation. 相似文献
38.
Using molecular dynamics simulations and steady‐state fluorescence spectroscopy, we have identified a conformational change in the active site of a thermophilic flavoenzyme, NADH oxidase from Thermus thermophilus HB8 (NOX). The enzyme's far‐UV circular dichroism spectrum, intrinsic tryptophan fluorescence, and apparent molecular weight measured by dynamic light scattering varied little between 25 and 75°C. However, the fluorescence of the tightly bound FAD cofactor increased approximately fourfold over this temperature range. This effect appears not to be due to aggregation, unfolding, cofactor dissociation, or changes in quaternary structure. We therefore attribute the change in flavin fluorescence to a temperature‐dependent conformational change involving the NOX active site. Molecular dynamics simulations and the effects of mutating aromatic residues near the flavin suggest that the change in fluorescence results from a decrease in quenching by electron transfer from tyrosine 137 to the flavin. Proteins 2012. © 2011 Wiley Periodicals, Inc. 相似文献
39.
Maria de Lourdes Lucio Ferrarese Osvaldo Ferrarese-Filho JoĂo Domingos Rodrigues 《Acta Physiologiae Plantarum》2000,22(2):121-124
Ferulic acid uptake by soybean root in nutrient culture was investigated by the depletion method at different concentrations,
temperatures and pH. Results showed that soybean roots absorbed this compound at greater rates in the concentrations between
0.05-mM and 1.0-mM and it was concentration dependent. Ferulic acid uptake was unaffected at pH 4.5 or 6.0 but reduced at
pH 7.0. At pH 6.0, uptake rates decreased significantly with increasing temperature of nutrient solution. 相似文献
40.
Effect of soil water stress on soil respiration and its temperature sensitivity in an 18-year-old temperate Douglas-fir stand 总被引:5,自引:0,他引:5
RACHHPAL S. JASSAL T. ANDREW BLACK MICHAEL D. NOVAK DAVID GAUMONT-GUAY ZORAN NESIC 《Global Change Biology》2008,14(6):1305-1318
We analyzed 17 months (August 2005 to December 2006) of continuous measurements of soil CO2 efflux or soil respiration (RS) in an 18‐year‐old west‐coast temperate Douglas‐fir stand that experienced somewhat greater than normal summertime water deficit. For soil water content at the 4 cm depth (θ) > 0.11 m3 m?3 (corresponding to a soil water matric potential of ?2 MPa), RS was positively correlated to soil temperature at the 2 cm depth (TS). Below this value of θ, however, RS was largely decoupled from TS, and evapotranspiration, ecosystem respiration and gross primary productivity (GPP) began to decrease, dropping to about half of their maximum values when θ reached 0.07 m3 m?3. Soil water deficit substantially reduced RS sensitivity to temperature resulting in a Q10 significantly < 2. The absolute temperature sensitivity of RS (i.e. dRS/dTS) increased with θ up to 0.15 m3 m?3, above which it slowly declined. The value of dRS/dTS was nearly 0 for θ < 0.08 m3 m?3, thereby confirming that RS was largely unaffected by temperature under soil water stress conditions. Despite the possible effects of seasonality of photosynthesis, root activity and litterfall on RS, the observed decrease in its temperature sensitivity at low θ was consistent with the reduction in substrate availability due to a decrease in (a) microbial mobility, and diffusion of substrates and extracellular enzymes, and (b) the fraction of substrate that can react at high TS, which is associated with low θ. We found that an exponential (van't Hoff type) model with Q10 and R10 dependent on only θ explained 92% of the variance in half‐hourly values of RS, including the period with soil water stress conditions. We hypothesize that relating Q10 and R10 to θ not only accounted for the effects of TS on RS and its temperature sensitivity but also accounted for the seasonality of biotic (photosynthesis, root activity, and litterfall) and abiotic (soil moisture and temperature) controls and their interactions. 相似文献