1,089 research outputs found
Effect of thermal inhomogeneity for THz radiation from intrinsic Josephson junction stacks of BiSrCaCuO
Terahertz radiation from the mesa structures of
BiSrCaCuO is detected in samples with thin electrodes
nm. In samples with thick electrodes 400 nm, neither
radiations nor voltage jumps in current-voltage characteristics are detected.
This suggests that the thin electrode helps excite the Josephson plasma
oscillation as a result of the poor heat flow through the electrode. The
shielding effect by the electrode is not essential. We consider that the local
temperature rise is the origin of the synchronization of the phase kink for
terahertz radiation.Comment: 4 pages, 3 figure
CRISPR screens identify genes essential for in vivo virulence among proteins of hyperLOPIT-unassigned subcellular localization in Toxoplasma
Tachibana Yuta, Sasai Miwa, Yamamoto Masahiro, et al. CRISPR screens identify genes essential for in vivo virulence among proteins of hyperLOPIT-unassigned subcellular localization in Toxoplasma. mBio , e01728-24 (2024); https://doi.org/10.1128/mbio.01728-24.The research field to identify and characterize genes essential for in vivo virulence in Toxoplasma gondii has been dramatically advanced by a series of in vivo clustered regularly interspaced short palindromic repeats (CRISPR) screens. Although subcellular localizations of thousands of proteins were predicted by the spatial proteomic method called hyperLOPIT, those of more than 1,000 proteins remained unassigned, and their essentiality in virulence was also unknown. In this study, we generated two small-scale gRNA libraries targeting approximately 600 hyperLOPIT-unassigned proteins and performed in vivo CRISPR screens. As a result, we identified several genes essential for in vivo virulence that were previously unreported. We further characterized two candidates, TgGTPase and TgRimM, which are localized in the cytoplasm and the apicoplast, respectively. Both genes are essential for parasite virulence and widely conserved in the phylum Apicomplexa. Collectively, our current study provides a resource for estimating the in vivo essentiality of Toxoplasma proteins with previously unknown localizations
Positive feedback regulation of fzd7 expression robustly shapes a steep Wnt gradient in Xenopus heart development, together with sFRP1 and heparan sulfate
Acknowledgements We thank Dr. Yukio Nakamura (Aberdeen University, UK; Present address: Repertoire Genesis Inc., Japan.) and Dr. Masanori Taira (Chuo University, Japan) for their help in initiating this project; Dr. Takehiko Nakamura (Seikagaku Corporation, Japan) for NAH46 antibody and hybridoma; Dr. Osamu Yoshie (Kindai University, Japan) for HepSS-1 hybridoma; Dr. Makoto Matsuyama (Shigei Medical Research Institute, Japan) for the contribution to the generation of NAH46 and HepSS-1 antibody from the hybridomas; Dr. Steven D. Aird for technical editing of the manuscript. This international collaboration was supported in part by Daiwa Anglo-Japanese Foundation (12969/13787 to T.Y., B.A., T.M., and S.H.); with additional research support in Japan from MEXT/JSPS KAKENHI (19K16138 to T.Y., 18K06244/21K06183 to T.Y. and T.M.); and in the United Kingdom from BHF (RG/18/8/33673 to S.H.) and BBSRC (BB/N021924/1; BB/M001695/1 to S.H.). S.H. was a Royal Society/Leverhulme Trust Senior Research Fellow (SRF\R1\191017).Peer reviewedPublisher PD
Gene expression profiling in rats with depressive-like behavior
Individual differences indicate stronger phenotypes than model animals especially in behavioral studies, and some animals show unexpected behaviors in control and animal model groups. High-throughput analysis including cDNA microarray analysis are more affected by individual differences, because more samples are needed to reduce the difference in multiple factor analysis than single factor analysis such as real-time PCR. We measured the depressive-like behavior of over 100 normal rats in the forced swimming test and selected the rats for control and depression group from them to minimize the individual difference using data of force swimming test. Here, we provided the detail of methods and quality control parameters for the cDNA microarray data. This dataset can reflect the increase of depressive-like behavior. The dataset is deposited in the gene expression omnibus (GEO), series GSE63377
Quantum state tomography for Kerr parametric oscillators
Kerr parametric oscillators (KPOs) implemented in the circuit QED
architecture can operate as qubits. Their applications to quantum annealing and
universal quantum computation have been studied intensely. For these
applications, the readout of the state of KPOs is of practical importance. We
develop a scheme of state tomography for KPOs with reflection measurement.
Although it is known that the reflection coefficient depends on the state of
the KPO, it is unclear whether tomography of a qubit encoded into a KPO can be
performed in a practical way mitigating decoherence during the measurement, and
how accurate it is. We show that the reflection coefficient has a one-to-one
correspondence with a diagonal element of the density matrix of the qubit when
a probe frequency is properly chosen and an additional single-photon-drive is
introduced. Thus, our scheme offers a novel way to readout the qubit along an
axis of the Bloch sphere, and therefore the reflection measurement and
single-qubit gates can constitute state tomography
Demonstrating Bayesian Quantum Phase Estimation with Quantum Error Detection
Quantum phase estimation (QPE) serves as a building block of many different
quantum algorithms and finds important applications in computational chemistry
problems. Despite the rapid development of quantum hardware, experimental
demonstration of QPE for chemistry problems remains challenging due to its
large circuit depth and the lack of quantum resources to protect the hardware
from noise with fully fault-tolerant protocols. In the present work, we take a
step towards fault-tolerant quantum computing by demonstrating a QPE algorithm
on a Quantinuum trapped-ion computer. We employ a Bayesian approach to QPE and
introduce a routine for optimal parameter selection, which we combine with a
quantum error detection code carefully tailored to the hardware
capabilities. As a simple quantum chemistry example, we take a hydrogen
molecule represented by a two-qubit Hamiltonian and estimate its ground state
energy using our QPE protocol. In the experiment, we use the quantum circuits
containing as many as 920 physical two-qubit gates to estimate the ground state
energy within hartree of the exact value.Comment: 16 pages, 9 figure
Host genetics highlights IFN-γ-dependent Toxoplasma genes encoding secreted and non-secreted virulence factors in in vivo CRISPR screens
Secreted virulence factors of Toxoplasma to survive in immune-competent hosts have been extensively explored by classical genetics and in vivo CRISPR screen methods, whereas their requirements in immune-deficient hosts are incompletely understood. Those of non-secreted virulence factors are further enigmatic. Here we develop an in vivo CRISPR screen system to enrich not only secreted but also non-secreted virulence factors in virulent Toxoplasma-infected C57BL/6 mice. Notably, combined usage of immune-deficient Ifngr1−/− mice highlights genes encoding various non-secreted proteins as well as well-known effectors such as ROP5, ROP18, GRA12, and GRA45 as interferon-γ (IFN-γ)-dependent virulence genes. The screen results suggest a role of GRA72 for normal GRA17/GRA23 localization and the IFN-γ-dependent role of UFMylation-related genes. Collectively, our study demonstrates that host genetics can complement in vivo CRISPR screens to highlight genes encoding IFN-γ-dependent secreted and non-secreted virulence factors in Toxoplasma.Tachibana Y., Hashizaki E., Sasai M., et al. Host genetics highlights IFN-γ-dependent Toxoplasma genes encoding secreted and non-secreted virulence factors in in vivo CRISPR screens. Cell Reports 42, 112592 (2023); https://doi.org/10.1016/j.celrep.2023.112592
The effect of sharing a meal with a robot on feelings of loneliness during the eating experience.
This study aimed to explore the impact of communal eating with robots on feelings of loneliness and mood. The experiment involved 33 undergraduate and graduate students, who were divided into three groups: dining with a close other, dining with a robot, and dining alone. Participants dined for 10 minutes under their assigned conditions and completed questionnaires about loneliness and negative mood before and after the meal. The results showed that dining with a close other or a robot significantly reduced feelings of loneliness during the meal, and the effects of these groups were comparable. Additionally, dining with a close other significantly reduced negative mood compared to eating alone. However, dining with a robot did not show a significant change in negative mood compared to eating alone. These results suggest that eating with a robot may reduce loneliness to the same extent as eating with a close other, and also suggest that eating with a close other may reduce loneliness and negative mood. In the future, it is considered essential to address the limitations of this study and further explore the effectiveness of approaches to loneliness using robots
Deoxofluorination of graphite oxide with sulfur tetrafluoride
In this study, deoxofluorination of graphite oxide (GO) using sulfur tetrafluoride (SF₄) at a temperature below the decomposition temperature of GO (∼200 °C) was investigated for the first time with and without HF catalysis. At 25 °C, the reaction proceeds only at high SF₄ pressures (≥8 atm) when not catalyzed by HF and at 1 atm SF₄ under the catalysis of HF. The degree of fluorination increases at higher temperatures and SF₄ pressures. Hydroxy and carbonyl groups are replaced by fluorine following this reaction, and SF₄ and SOF₂ are introduced into the product, while the epoxy groups do not react. SF₄ and SOF₂ in the products are removed by washing with water. The obtained product is less hygroscopic than pristine GO owing to the hydrophobicity of the fluorine atom. The interlayer separation of the product is increased after deoxofluorination despite the smaller size of fluorine than the sizes of the oxygen-containing functional groups. When compared with direct fluorination using elemental fluorine, deoxofluorination using SF₄ has the advantages of high reactivity with hydroxy groups and the preservation of the carbon skeleton, and the reaction results in the formation of graphite oxyfluoride
PERFORMANCE ANALYSIS OF THE START PHASE OF SKELETON ATHLETES AT INTERNATIONAL COMPETITIONS
The purpose of this study was to investigate characteristics of the skeleton start motion from the viewpoint of step frequency and step length. Twenty-six male and twenty female skeleton athletes at international competitions were videotaped and analysed their start motion with the three-dimensional DLT method. There were high significant correlations between the start time and the goal time in both men (r = 0.947, p \u3c 0.001) and women (r = 0.741, p \u3c 0.001). As for the start time, men showed a significant correlation with the step length at the 1st step (r = -0.606, p \u3c 0.01) while women showed significant correlations with the step frequency at the 1st (r = -0.475, p \u3c 0.05), 3rd (r = -0.497, p \u3c 0.05) and 5th (r = -0.471, p \u3c 0.05) step. These result indicated that men emphasized step length at the 1st step, while women relied more on step frequency
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