620 research outputs found
Phase Shifts of the Circadian Locomotor Rhythm Induced by Pigment-Dispersing Factor in the Cricket Gryllus bimaculatus
Pigment-dispersing factors (PDFs) are octadeca-peptides widely distributed in insect optic lobes and brain. In this study, we have purified PDF and determined its amino acid sequence in the cricket Gryllus bimaculatus. Its primary structure was NSEIINSLLGLPKVLNDA-NH2, homologous to other PDH family members so far reported. When injected into the optic lobe of experimentally blinded adult male crickets, Gryllus-PDF induced phase shifts in their activity rhythms in a phase dependent and dose dependent manner. The resulted phase response curve (PRC) showed delays during the late subjective night to early subjective day and advances during the mid subjective day to mid subjective night. The PRC was different in shape from those for light, serotonin and temperature. These results suggest that PDF plays a role in phase regulation of the circadian clock through a separate pathway from those of other known phase regulating agents
Optimal Data Split Methodology for Model Validation
The decision to incorporate cross-validation into validation processes of
mathematical models raises an immediate question - how should one partition the
data into calibration and validation sets? We answer this question
systematically: we present an algorithm to find the optimal partition of the
data subject to certain constraints. While doing this, we address two critical
issues: 1) that the model be evaluated with respect to predictions of a given
quantity of interest and its ability to reproduce the data, and 2) that the
model be highly challenged by the validation set, assuming it is properly
informed by the calibration set. This framework also relies on the interaction
between the experimentalist and/or modeler, who understand the physical system
and the limitations of the model; the decision-maker, who understands and can
quantify the cost of model failure; and the computational scientists, who
strive to determine if the model satisfies both the modeler's and decision
maker's requirements. We also note that our framework is quite general, and may
be applied to a wide range of problems. Here, we illustrate it through a
specific example involving a data reduction model for an ICCD camera from a
shock-tube experiment located at the NASA Ames Research Center (ARC).Comment: Submitted to International Conference on Modeling, Simulation and
Control 2011 (ICMSC'11), San Francisco, USA, 19-21 October, 201
A Comprehensive and Versatile Multimodal Deep Learning Approach for Predicting Diverse Properties of Advanced Materials
We present a multimodal deep learning (MDL) framework for predicting physical
properties of a 10-dimensional acrylic polymer composite material by merging
physical attributes and chemical data. Our MDL model comprises four modules,
including three generative deep learning models for material structure
characterization and a fourth model for property prediction. Our approach
handles an 18-dimensional complexity, with 10 compositional inputs and 8
property outputs, successfully predicting 913,680 property data points across
114,210 composition conditions. This level of complexity is unprecedented in
computational materials science, particularly for materials with undefined
structures. We propose a framework to analyze the high-dimensional information
space for inverse material design, demonstrating flexibility and adaptability
to various materials and scales, provided sufficient data is available. This
study advances future research on different materials and the development of
more sophisticated models, drawing us closer to the ultimate goal of predicting
all properties of all materials.Comment: 38 pages, 17 figures, 1 tabl
The Nuclear Receptor Genes HR3 and E75 Are Required for the Circadian Rhythm in a Primitive Insect
Insect circadian rhythms are generated by a circadian clock consisting of transcriptional/translational feedback loops, in which CYCLE and CLOCK are the key elements in activating the transcription of various clock genes such as timeless (tim) and period (per). Although the transcriptional regulation of Clock (Clk) has been profoundly studied, little is known about the regulation of cycle (cyc). Here, we identify the orphan nuclear receptor genes HR3 and E75, which are orthologs of mammalian clock genes, Rorα and Rev-erbα, respectively, as factors involved in the rhythmic expression of the cyc gene in a primitive insect, the firebrat Thermobia domestica. Our results show that HR3 and E75 are rhythmically expressed, and their normal, rhythmic expression is required for the persistence of locomotor rhythms. Their RNAi considerably altered the rhythmic transcription of not only cyc but also tim. Surprisingly, the RNAi of HR3 revealed the rhythmic expression of Clk, suggesting that this ancestral insect species possesses the mechanisms for rhythmic expression of both cyc and Clk genes. When either HR3 or E75 was knocked down, tim, cyc, and Clk or tim and cyc, respectively, oscillated in phase, suggesting that the two genes play an important role in the regulation of the phase relationship among the clock genes. Interestingly, HR3 and E75 were also found to be involved in the regulation of ecdysis, suggesting that they interconnect the circadian clock and developmental processes
(1R,2R)-1,2-Diphenyl-1,2-bis(1H-tetrazol-1-yl)ethane
The title compound, C16H14N8, is a new chiral ligand designed for applications in supramolecular chemistry and Fe2+ spin-crossover complexes. The crystal structure shows a herring-bone arrangement of the molecules, which are mutually linked via intermolecular C—H⋯N interactions mainly donated by the alkyl and tetrazole H atoms
The gene regulatory system for specifying germ layers in early embryos of the simple chordate
動物胚の遺伝子発現を数式で表現 --動物の胚葉形成システムをまるごと理解--.京都大学プレスリリース. 2021-06-10.In animal embryos, gene regulatory networks control the dynamics of gene expression in cells and coordinate such dynamics among cells. In ascidian embryos, gene expression dynamics have been dissected at the single-cell resolution. Here, we revealed mathematical functions that represent the regulatory logics of all regulatory genes expressed at the 32-cell stage when the germ layers are largely specified. These functions collectively explain the entire mechanism by which gene expression dynamics are controlled coordinately in early embryos. We found that regulatory functions for genes expressed in each of the specific lineages contain a common core regulatory mechanism. Last, we showed that the expression of the regulatory genes became reproducible by calculation and controllable by experimental manipulations. Thus, these regulatory functions represent an architectural design for the germ layer specification of this chordate and provide a platform for simulations and experiments to understand the operating principles of gene regulatory networks
Influence of pulsive pressure waves on liquid penetration into wood in semi-opened container
The purpose of this paper was to confirm the influence of pulsive pressure waves on the liquid penetration into wood in the semi-opened container. Wood block sample was irradiated by the pulsive pressure waves in the semi-opened container filled with water used as a liquid. The irradiation was also performed in the closed container for the comparison. The water penetration into the sample was promoted by the pressure-wave irradiation. There was little difference in the degree of the penetration between the closed and the semi-opened containers. It was presumed from the measured hydraulic pressure that the pressure-wave energy irradiated on the sample in the closed container was higher than that in the semi-opened container. It was also presumed that the cavitation generation was promoted in the semi-opened container. This indicates that the cavitation as well as the pressure waves themselves affected the liquid penetration into wood. The compressive deformation of the sample irradiated in the semi-opened container was slightly smaller than that in the closed container. This indicates that the pulsive pressure-wave irradiation in the semi-opened container promoted the liquid penetration into wood with less compressive deformation
Fasting period after Rybelsus administration influences clinical benefit
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have been attracted attention for various beneficial effects. Among them, oral semaglutide (Rybelsus) was developed using the absorption enhancer sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). The relationship between the bioavailability and post-dose fasting time period was analyzed. The results showed that i) its bioavailability with drinking 50mL and 120mL of water together was almost similar, ii) bioavailability for 240mL intake was about 2/3 of 50-120mL, iii) general availability would be about 1.4% for 50-120ml water, and 0.8% for 240mL of water. Tolerability and safety of Rybelsus showed similar results for healthy subjects, patients with renal and/or hepatic impairment. From mentioned above, Rybelsus has been one of the topic agents with characteristic mechanism of SNAC and clinical benefit of GLP-1RA. It will be expected to be applied widely in actual diabetic practice
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