1,850 research outputs found
Holomorphic functions on complex Banach lattices
We introduce and study the algebraic, analytic and lattice properties of
regular homogeneous polynomials and holomorphic functions on complex Banach
lattices. We show that the theory of power series with regular terms is closer
to the theory of functions of several complex variables than the theory of
holomorphic functions on Banach spaces. We extend the concept of the Bohr
radius to Banach lattices and show that it provides us with a lower bound for
the ratio between the radius of regular convergence and the radius of
convergence of a regular holomorphic function. This allows us to show that the
radius of regular convergence coincides with the radius of convergence for
holomorphic functions on finite dimensional spaces and orthogonally additive
holomorphic functions but that these radii can be radically different on
for
Deep Learning Image Analysis to Isolate and Characterize Different Stages of S-phase in Human Cells
Abstract. This research used deep learning for image analysis by isolating and characterizing distinct DNA replication patterns in human cells. By leveraging high-resolution microscopy images of multiple cells stained with 5-Ethynyl-2′-deoxyuridine (EdU), a replication marker, this analysis utilized Convolutional Neural Networks (CNNs) to perform image segmentation and to provide robust and reliable classification results. First multiple cells in a field of focus were identified using a pretrained CNN called Cellpose. After identifying the location of each cell in the image a python script was created to crop out each cell into individual .tif files. After careful annotation, a CNN was created from scratch using the TensorFlow Keras package and trained on those images to categorize them into five distinct replication patterns. Using a holdout test set our model was able to achieve an accuracy of 86.5%. This analysis method for segmentation and classification enhances the efficiency and reproducibility of DNA replication analysis, allowing for high-throughput processing and analysis of replication foci. This research can enhance image analysis in cell biology by providing a time-efficient and accurate tool to investigate replication dynamics, advance cancer research, and contribute to scientific discovery in various domains
Fullerene—Porphyrin Constructs
Porphyrins and fullerenes are spontaneously attracted to each other. This new supramolecular recognition element can be used to construct discrete host-guest complexes, as well as ordered arrays of interleaved porphyrins and fullerenes. The fullerene-porphyrin interaction underlies successful chromatographic separations of fullerenes, and there are promising applications in the areas of porous framework solids and photovoltaic devices
A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36
Background Rust diseases are of major importance in wheat production worldwide. With the constant evolution of new rust strains and their adaptation to higher temperatures, consistent and durable disease resistance is a key challenge. Environmental conditions affect resistance gene performance, but the basis for this is poorly understood. Results Here we show that a change in day temperature affects wheat resistance to Puccinia striiformis f. sp tritici (Pst), the causal agent of yellow (or stripe) rust. Using adult plants of near-isogenic lines UC1041 +/- Yr36, there was no significant difference between Pst percentage uredia coverage in plants grown at day temperatures of 18°C or 25°C in adult UC1041 + Yr36 plants. However, when plants were transferred to the lower day temperature at the time of Pst inoculation, infection increased up to two fold. Interestingly, this response was independent of Yr36, which has previously been reported as a temperature-responsive resistance gene as Pst development in adult UC1041 -Yr36 plants was similarly affected by the plants experiencing a temperature reduction. In addition, UC1041 -Yr36 plants grown at the lower temperature then transferred to the higher temperature were effectively resistant and a temperature change in either direction was shown to affect Pst development up to 8 days prior to inoculation. Results for seedlings were similar, but more variable compared to adult plants. Enhanced resistance to Pst was observed in seedlings of UC1041 and the cultivar Shamrock when transferred to the higher temperature. Resistance was not affected in seedlings of cultivar Solstice by a temperature change in either direction. Conclusions Yr36 is effective at 18°C, refining the lower range of temperature at which resistance against Pst is conferred compared to previous studies. Results reveal previously uncharacterised defence temperature sensitivity in the UC1041 background which is caused by a change in temperature and independently of Yr36. This novel phenotype is present in some cultivars but absent in others, suggesting that Pst defence may be more stable in some cultivars than others when plants are exposed to varying temperatures
Interferometry with Photon-Subtracted Thermal Light
We propose and implement a quantum procedure for enhancing the sensitivity
with which one can determine the phase shift experienced by a weak light beam
possessing thermal statistics in passing through an interferometer. Our
procedure entails subtracting exactly one (which can be generalized to m)
photons from the light field exiting an interferometer containing a
phase-shifting element in one of its arms. As a consequence of the process of
photon subtraction, and somewhat surprisingly, the mean photon number and
signal-to-noise ratio of the resulting light field are thereby increased,
leading to enhanced interferometry. This method can be used to increase
measurement sensitivity in a variety of practical applications, including that
of forming the image of an object illuminated only by weak thermal light
5-hydroxytryptamine (5-HT) cellular sequestration during chronic exposure delays 5-HT<sub>3</sub> receptor resensitization due to Its subsequent release
The serotonergic synapse is dynamically regulated by serotonin (5-hydroxytryptamine (5-HT)) with elevated levels leading to the down-regulation of the serotonin transporter and a variety of 5-HT receptors, including the 5-HT type-3 (5-HT(3)) receptors. We report that recombinantly expressed 5-HT(3) receptor binding sites are reduced by chronic exposure to 5-HT (IC(50) of 154.0 ± 45.7 μm, t(½) = 28.6 min). This is confirmed for 5-HT(3) receptor-induced contractions in the guinea pig ileum, which are down-regulated after chronic, but not acute, exposure to 5-HT. The loss of receptor function does not involve endocytosis, and surface receptor levels are unaltered. The rate and extent of down-regulation is potentiated by serotonin transporter function (IC(50) of 2.3 ± 1.0 μm, t(½) = 3.4 min). Interestingly, the level of 5-HT uptake correlates with the extent of down-regulation. Using TX-114 extraction, we find that accumulated 5-HT remains soluble and not membrane-bound. This cytoplasmically sequestered 5-HT is readily releasable from both COS-7 cells and the guinea pig ileum. Moreover, the 5-HT level released is sufficient to prevent recovery from receptor desensitization in the guinea pig ileum. Together, these findings suggest the existence of a novel mechanism of down-regulation where the chronic release of sequestered 5-HT prolongs receptor desensitization
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