155 research outputs found
Comparison of two 3D tracking paradigms for freely flying insects
In this paper, we discuss and compare state-of-the-art 3D tracking paradigms for flying insects such as Drosophila melanogaster. If two cameras are employed to estimate the trajectories of these identical appearing objects, calculating stereo and temporal correspondences leads to an NP-hard assignment problem. Currently, there are two different types of approaches discussed in the literature: probabilistic approaches and global correspondence selection approaches. Both have advantages and limitations in terms of accuracy and complexity. Here, we present algorithms for both paradigms. The probabilistic approach utilizes the Kalman filter for temporal tracking. The correspondence selection approach calculates the trajectories based on an overall cost function. Limitations of both approaches are addressed by integrating a third camera to verify consistency of the stereo pairings and to reduce the complexity of the global selection. Furthermore, a novel greedy optimization scheme is introduced for the correspondence selection approach. We compare both paradigms based on synthetic data with ground truth availability. Results show that the global selection is more accurate, while the previously proposed tracking-by-matching (probabilistic) approach is causal and feasible for longer tracking periods and very high target densities. We further demonstrate that our extended global selection scheme outperforms current correspondence selection approaches in tracking accuracy and tracking time
The Parametric Symmetry and Numbers of the Entangled Class of 2 \times M \times N System
We present in the work two intriguing results in the entanglement
classification of pure and true tripartite entangled state of under stochastic local operation and classical communication. (i) the
internal symmetric properties of the nonlocal parameters in the continuous
entangled class; (ii) the analytic expression for the total numbers of the true
and pure entangled class states. These properties help
people to know more of the nature of the entangled system.Comment: 12 pages, 5 figure
BaFe12O19 single-particle-chain nanofibers : preparation, characterization, formation principle, and magnetization reversal mechanism
BaFe12O19 single-particle-chain
nanofibers have been successfully prepared by
an electrospinning method and calcination
process, and their morphology, chemistry,
and crystal structure have been characterized
at the nanoscale. It is found that individual
BaFe12O19 nanofibers consist of single nanoparticles which are found to stack along the
nanofiber axis. The chemical analysis shows that the atomic ratio of Ba/Fe is 1:12, suggesting a
BaFe12O19 composition. The crystal structure of the BaFe12O19 single-particle-chain nanofibers
is proved to be M-type hexagonal. The single crystallites on each BaFe12O19 single-particlechain
nanofibers have random orientations. A formation mechanism is proposed based on
thermogravimetry/differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and transmission
electron microscopy (TEM) at six temperatures, 250, 400, 500, 600, 650, and 800 �C.
The magnetic measurement of the BaFe12O19 single-particle-chain nanofibers reveals that the
coercivity reaches a maximum of 5943 Oe and the saturated magnetization is 71.5 emu/g at
room temperature. Theoretical analysis at the micromagnetism level is adapted to describe the
magnetic behavior of the BaFe12O19 single-particle-chain nanofibers
Rnd3/RhoE Modulates HIF1α/VEGF Signaling by Stabilizing HIF1α and Regulates Responsive Cardiac Angiogenesis
The insufficiency of compensatory angiogenesis in the heart of patients with hypertension contributes to heart failure transition. The hypoxia-inducible factor 1α-vascular endothelial growth factor (HIF1α-VEGF) signaling cascade controls responsive angiogenesis. One of the challenges in reprograming the insufficient angiogenesis is to achieve a sustainable tissue exposure to the proangiogenic factors, such as HIF1α stabilization. In this study, we identified Rnd3, a small Rho GTPase, as a proangiogenic factor participating in the regulation of the HIF1α-VEGF signaling cascade. Rnd3 physically interacted with and stabilized HIF1α, and consequently promoted VEGFA expression and endothelial cell tube formation. To demonstrate this proangiogenic role of Rnd3 in vivo, we generated Rnd3 knockout mice. Rnd3 haploinsufficient (Rnd3(+/-)) mice were viable, yet developed dilated cardiomyopathy with heart failure after transverse aortic constriction stress. The poststress Rnd3(+/-) hearts showed significantly impaired angiogenesis and decreased HIF1α and VEGFA expression. The angiogenesis defect and heart failure phenotype were partially rescued by cobalt chloride treatment, a HIF1α stabilizer, confirming a critical role of Rnd3 in stress-responsive angiogenesis. Furthermore, we generated Rnd3 transgenic mice and demonstrated that Rnd3 overexpression in heart had a cardioprotective effect through reserved cardiac function and preserved responsive angiogenesis after pressure overload. Finally, we assessed the expression levels of Rnd3 in the human heart and detected significant downregulation of Rnd3 in patients with end-stage heart failure. We concluded that Rnd3 acted as a novel proangiogenic factor involved in cardiac responsive angiogenesis through HIF1α-VEGFA signaling promotion. Rnd3 downregulation observed in patients with heart failure may explain the insufficient compensatory angiogenesis involved in the transition to heart failure
Template Route to Chemically Engineering Cavities at Nanoscale: A Case Study of Zn(OH)2 Template
A size-controlled Zn(OH)2 template is used as a case study to explain the chemical strategy that can be executed to chemically engineering various nanoscale cavities. Zn(OH)2 octahedron with 8 vertices and 14 edges is fabricated via a low temperature solution route. The size can be tuned from 1 to 30 μm by changing the reaction conditions. Two methods can be selected for the hollow process without loss of the original shape of Zn(OH)2 template. Ion-replacement reaction is suitable for fabrication of hollow sulfides based on the solubility difference between Zn(OH)2 and products. Controlled chemical deposition is utilized to coat an oxide layer on the surface of Zn(OH)2 template. The abundant hydroxyl groups on Zn(OH)2 afford strong coordination ability with cations and help to the coating of a shell layer. The rudimental Zn(OH)2 core is eliminated with ammonia solution. In addition, ZnO-based heterostructures possessing better chemical or physical properties can also be prepared via this unique templating process. Room-temperature photoluminescence spectra of the heterostructures and hollow structures are also shown to study their optical properties
Nuclear import receptors are recruited by FG-nucleoporins to rescue hallmarks of TDP-43 proteinopathy
Background: Cytoplasmic mislocalization and aggregation of TAR DNA-binding protein-43 (TDP-43) is a hallmark of the amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD) disease spectrum, causing both nuclear loss-of-function and cytoplasmic toxic gain-of-function phenotypes. While TDP-43 proteinopathy has been associated with defects in nucleocytoplasmic transport, this process is still poorly understood. Here we study the role of karyopherin-β1 (KPNB1) and other nuclear import receptors in regulating TDP-43 pathology.
Methods: We used immunostaining, immunoprecipitation, biochemical and toxicity assays in cell lines, primary neuron and organotypic mouse brain slice cultures, to determine the impact of KPNB1 on the solubility, localization, and toxicity of pathological TDP-43 constructs. Postmortem patient brain and spinal cord tissue was stained to assess KPNB1 colocalization with TDP-43 inclusions. Turbidity assays were employed to study the dissolution and prevention of aggregation of recombinant TDP-43 fibrils in vitro. Fly models of TDP-43 proteinopathy were used to determine the effect of KPNB1 on their neurodegenerative phenotype in vivo.
Results: We discovered that several members of the nuclear import receptor protein family can reduce the formation of pathological TDP-43 aggregates. Using KPNB1 as a model, we found that its activity depends on the prion-like C-terminal region of TDP-43, which mediates the co-aggregation with phenylalanine and glycine-rich nucleoporins (FG-Nups) such as Nup62. KPNB1 is recruited into these co-aggregates where it acts as a molecular chaperone that reverses aberrant phase transition of Nup62 and TDP-43. These findings are supported by the discovery that Nup62 and KPNB1 are also sequestered into pathological TDP-43 aggregates in ALS/FTD postmortem CNS tissue, and by the identification of the fly ortholog of KPNB1 as a strong protective modifier in Drosophila models of TDP-43 proteinopathy. Our results show that KPNB1 can rescue all hallmarks of TDP-43 pathology, by restoring its solubility and nuclear localization, and reducing neurodegeneration in cellular and animal models of ALS/FTD.
Conclusion: Our findings suggest a novel NLS-independent mechanism where, analogous to its canonical role in dissolving the diffusion barrier formed by FG-Nups in the nuclear pore, KPNB1 is recruited into TDP-43/FG-Nup co-aggregates present in TDP-43 proteinopathies and therapeutically reverses their deleterious phase transition and mislocalization, mitigating neurodegeneration. Graphical Abstract: [Figure not available: see fulltext.]
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Genetic Diversity among Wheat Accessions from the USDA National Small Grains Collection
Accessions of common wheat (Triticum aestivum L. subsp. aestivum) from the USDA–ARS National Small Grains Collection (NSGC) are a resource for wheat scientists worldwide. The genetic diversity of the wheat core subset, representing approximately 10% of the collection’s 42,138 T. aestivum accessions, was examined using 390 diversity arrays technology (DArT) markers, 4941 single nucleotide polymorphisms (SNPs), and descriptor data. The marker profiles revealed duplicates, which were excluded to form an informative core (iCore) of 3230 accessions. The iCore population structure and diversity within various subgroups were examined with analysis of molecular variance, principal coordinate analysis, cluster analysis, and by ranking the contribution of individual accessions to overall diversity. Accession groups based on molecular marker data corresponded well to their geographic origin, and population structure was accounted for primarily by differences between Iranian landrace accessions and the rest of the accessions. Accessions classified as breeding lines were overrepresented among those ranked as most diverse based on SNP data, whereas Iranian landraces were underrepresented. Although less diverse as a group, Iranian landrace accessions had a higher frequency of resistance to bunt diseases and Russian wheat aphid compared with the iCore as a whole. The present study provides support for establishing core subsets based on geographic origin of accessions and will be a basis for further study of diversity among NSGC wheats
Functional relationship of furfural yields and the hemicellulose-derived sugars in the hydrolysates from corncob by microwave-assisted hydrothermal pretreatment
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