Broad Range Of Morphologies Research Articles

Artificial Intelligence-Based Counting Algorithm Enables Accurate and Detailed Analysis of the Broad Spectrum of Spot Morphologies Observed in Antigen-Specific B-Cell ELISPOT and FluoroSpot Assays.

Antigen-specific B-cell ELISPOT and multicolor FluoroSpot assays, in which the membrane-bound antigen itself serves as the capture reagent for the antibodies that B cells secrete, inherently result in a broad range of spot sizes and intensities. The diversity of secretory footprint morphologies reflects the polyclonal nature of the antigen-specific B cell repertoire, with individual antibody-secreting B cells in the test sample differing in their affinity for the antigen, fine epitope specificity, and activation/secretion kinetics. To account for these heterogeneous spot morphologies, and to eliminate the need for setting up subjective counting parameters well-by-well, CTL introduces here its cutting-edge deep learning-based IntelliCount™ algorithm within the ImmunoSpot® Studio Software Suite, which integrates CTL's proprietary deep neural network. Here, we report detailed analyses of spots with a broad range of morphologies that were challenging to analyze using standard parameter-based counting approaches. IntelliCount™, especially in conjunction with high dynamic range (HDR) imaging, permits the extraction of accurate, high-content information of such spots, as required for assessing the affinity distribution of an antigen-specific memory B-cell repertoire ex vivo. IntelliCount™ also extends the range in which the number of antibody-secreting B cells plated and spots detected follow a linear function; that is, in which the frequencies of antigen-specific B cells can be accurately established. Introducing high-content analysis of secretory footprints in B-cell ELISPOT/FluoroSpot assays, therefore, fundamentally enhances the depth in which an antigen-specific B-cell repertoire can be studied using freshlyisolated or cryopreserved primary cell material, such as peripheral blood mononuclear cells.

Shape-controlled monolayer MoSe2 flakes by chemical vapor deposition towards tuning the photoluminescence emission

In this study, we report on the controllable chemical vapor deposition (CVD) synthesis of monolayer MoSe2 flakes with different shapes such as hexagons, triangles, sawtooth hexagons, dendrites and fractals deposited on SiO2/Si substrates. This broad range of morphologies is due to the change in the vapor composition resulting from the confinement of the MoO3 and Se vapor and to the variation in the growth rate of the variable shaped MoSe2 crystals. It is also revealed that the photoluminescence (PL) response of the MoSe2 flakes is strongly affected by their shape and size. Our findings will open new avenues towards achieving morphology-controlled monolayer MoSe2 flakes for optoelectronic and energy harvesting systems.

Batch-Mask: Automated Image Segmentation for Organisms with Limbless or Non-Standard Body Forms.

Efficient comparisons of biological color patterns are critical for understanding the mechanisms by which organisms evolve in nature, including sexual selection, predator-prey interactions, and thermoregulation. However, limbless, elongate, or spiral-shaped organisms do not conform to the standard orientation and photographic techniques required for many automated analyses. Currently, large-scale color analysis of elongate animals requires time-consuming manual landmarking, which reduces their representation in coloration research despite their ecological importance. We present Batch-Mask: an automated, customizable workflow to automatically analyze large photographic datasets to isolate non-standard biological organisms from the background. Batch-Maskis completely open-source and does not depend on any proprietary software. We also present a user guide for fine-tuning weights to a custom dataset and incorporating existing manual visual analysis tools (e.g., micaToolbox) into a single automated workflow for comparing color patterns across images. Batch-Maskwas 60x faster than manual landmarking and produced masks that correctly identified 96% of all snake pixels. To validate our approach, we used micaToolbox to compare pattern energy in a sample set of snake photographs segmented by Batch-Maskand humans and found no significant difference in the output results. The fine-tuned weights, user guide, and automated workflow substantially decrease the amount of time and attention required to quantitatively analyze non-standard biological subjects. With these tools, biologists can compare color, pattern, and shape differences in large datasets that include significant morphological variation in elongate body forms. This advance is especially valuable for comparative analyses of natural history collections across a broad range of morphologies. Through landmark-free automation, Batch-Maskcan greatly expand the scale of space, time, or taxonomic breadth across which color variation can be quantitatively examined.

OMEGA – OSIRIS Mapping of Emission-line Galaxies in A901/2: II. – Environmental influence on integrated star formation properties and AGN activity

We present a study of the star formation and AGN activity for galaxies in the Abell 901/2 multi-cluster system at z~0.167 as part of the OMEGA survey. Using Tuneable Filter data obtained with the OSIRIS instrument at the GTC we produce spectra covering the Halpha and [N II] spectral lines for more than 400 galaxies. Using optical emission-line diagnostics, we identify a significant number of galaxies hosting AGN, which tend to have high masses and a broad range of morphologies. Moreover, within the environmental densities probed by our study, we find no environmental dependence on the fraction of galaxies hosting AGN. The analysis of the integrated Halpha emission shows that the specific star formation rates (SSFRs) of a majority of the cluster galaxies are below the field values for a given stellar mass. We interpret this result as evidence for a slow decrease in the star formation activity of star-forming galaxies as they fall into higher-density regions, contrary to some previous studies which suggested a rapid truncation of star formation. We find that most of the intermediate- and high-mass spiral galaxies go through a phase in which their star formation is suppressed but still retain significant star-formation activity. During this phase, these galaxies tend to retain their spiral morphology while their colours become redder. The presence of this type of galaxies in high density regions indicates that the physical mechanism responsible for suppressing star-formation affects mainly the gas component of the galaxies, suggesting that ram-pressure stripping or starvation are potentially responsible.

Up-scaling the synthesis of Cu2O submicron particles with controlled morphologies for solar H2 evolution from water

The synthesis of Cu2O was studied to examine the effects of up-scaling on the size and morphology of the resultant particles. As a result, a successful protocol employing an automated laboratory reactor was developed for large-scale synthesis of phase-pure Cu2O colloids with specific sizes in the submicron to micrometer range (0.2–2.6μm). The as-synthesized products have been studied by means of powder X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, UV–Vis–NIR spectroscopy, scanning electron microscopy, and photoelectrochemical measurements. A broad range of morphologies, both equilibrium (stellated octahedrons, cubes, cuboctahedrons, truncated octahedrons, truncated cuboctahedrons) and metastable (cage-like hierarchical structures, microspheres with flower-like texture), with uniform sizes have been selectively prepared either by careful tuning of synthesis conditions. Recrystallization of primary aggregates through Ostwald ripening is proposed as the formation mechanism for these Cu2O structures. As a photocathode for photoelectrochemical H2 evolution, Cu2O submicron cubes with exposed {001} facets exhibit a high open-circuit potential of ca. 0.9V vs. the RHE at pH 1.

Chiroptical aggregates from block copolymer bearing amino acid moieties in aqueous solution

AbstractOptically active poly(ethylene glycol) monomethyl ether‐b‐poly(methacryloyl‐L‐leucine methyl ester) (denoted as MPEG‐b‐PMALM) copolymers were prepared via atom transfer radical polymerization (ATRP), using bromine (Br) end‐capped poly(ethylene glycol) monomethyl ether (denoted as MPEG‐Br) as macroinitiator in the presence of CuBr/tris(2‐dimethylaminoethy1)amine (Me6TREN) as catalytic system. Broad range of morphologies, such as spherical, cylindrical, and vesicular micelles, which were prepared by initially dissolving prepared polymer in organic solvent at different concentration followed by addition various amount of water before dialysis against water to remove any added solvent, was observed by transmission electron microscope (TEM). More detailed chiroptical properties of the micelles/aggregates in aqueous solution were evaluated by circular dichroism (CD) spectroscopy as a function of micelles morphologies, polymer concentration, solvents employed, temperature, etc. The micellar solutions exhibit almost the same CD spectra regardless of its morphologies. The intensity of the CD spectra of the cylindrical micelles decreased in the molar ellipticities as the micellar concentration in water was increased. The Cotton effect was markedly changed when the solvent hydrophobicity was changed by addition of trifluoromethyl ethanol (TFME) to water. The intensity of the CD spectra decreased not too much within the temperature range from 20 °C to 90 °C, indicating good stability of the micelles upon temperature variation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1345–1355, 2009

Linking structure and nanomechanical properties via instrumented nanoindentations on well-defined and fine-tuned morphology poly(ethylene)

Several poly(ethylene) samples with a broad range of morphologies were studied in this work using nanoindentations. The samples had degrees of crystallinity ranging from 30 to 100% while their Young's modulus ranged from few tens of MPa up to several GPa. Experimental conditions for the correct evaluation of Young's modulus were at first identified, choosing a suitable loading rate in order to minimize viscoelastic effects on the unloading. The force curves, i.e., plots of applied load vs. penetration depth, were then analyzed following two common procedures available in the literature. None of these procedures leads to satisfying results when compared to other experimental techniques. However, it was found that a recently proposed correction factor to the Oliver and Pharr procedure allows to evaluate reliably Young's modulus of the poly(ethylene) samples exhibiting very different, fine-tuned morphologies.

Optically active micelles from self-assembly of MPEG-b-PMALM copolymer in water

Reported here is fabrication of optically active micelles with broad range of morphologies in water, such as spheres, cylinders, and vesicles, from self-assembly of poly(ethylene glycol) monomethyl ether-b-poly- (methacryloyl-L-leucine methyl ester) (MPEG-b-PMALM) copolymer, which was prepared via atom transfer radical polymerization (ATRP) from vinyl monomer bearing chiral amino acid moieties, N-methacryloyl L-leucine methyl ester (MALM), using bromine (Br) end-capped poly(ethylene golycol) monomethylether (MPEG-Br) as macroinitiator in the presence of CuBr/Me 6TREN as catalytic system.

Electrical properties of morphologically characterized neurons in the intergeniculate leaflet of the rat thalamus

The intergeniculate leaflet (IGL) is a flat thalamic nucleus that responds to retinal illumination, but also to non-photic input from many brain areas. Its only known function is to modulate the circadian rhythm generated by the suprachiasmatic nucleus. Previously, the firing behavior of cells in IGL has been investigated with extra-cellular recordings, but intracellular recordings from morphologically identified mammalian IGL neurons are lacking. We recorded from and labeled IGL cells in rat brain slices to characterize their basic membrane properties and cell morphology. A high fraction of neurons (82.5%) were spontaneously active. The silent cells were identified as neurons by electrophysiological techniques. The spontaneous activity was due to intrinsic membrane properties, and not driven by rhythmic synaptic input. Most spontaneously active cells had a very regular firing pattern with a coefficient of variation of the spike intervals <0.12 in more than 50% of the cells. Rebound depolarization after a hyperpolarizing pulse, usually with one fast action potential on top, was observed in 80% of the cells. The silent neurons had a range of resting membrane potentials and spike thresholds overlapping with the active ones. This suggests that spontaneous activity was controlled by several, yet undetermined factors in addition to membrane potential. Within the IGL we found a broad range of morphologies without apparent categories and no significant correlation with activity. However, the spontaneous, usually regular, spiking and the rebound depolarization of IGL cells is typical a feature that distinguish them from neurons in ventral and from interneurons in the dorsal lateral geniculate nuclei.

Morphological considerations on the mechanical properties of blown high-density polyethylene films

Blown films having a broad range of morphologies were prepared from high-density polyethylenes (HDPE) with unimodal and bimodal molecular weight distribution under several processing conditions, and the effect of their morphological features on the dart drop impact resistance, Elmendorf tear strength, and tensile properties of the films has been studied. The organization of lamellar stacks seems to play a critical role on the mechanical properties of the blown HDPE films. The dart drop impact resistance of the blown HDPE films is highly dependent on the presence of the network structure of lamellar stacks and the level of the intraconnectivity and interconnectivity of lamellar stacks. The coherent orientation of lamellar stacks leads to significant anisotropy of tear and tensile properties. © 1997 John Wiley & Sons, Inc.