Improved Analytic Solution of Black Hole Superradiance

The approximate solution of the Klein-Gordon equation for a real scalar field of mass $\mu$ in the geometry of a Kerr black hole obtained by Detweiler \cite{Detweiler:1980uk} is widely used in the analysis of the stability of black holes as well as the search of axion-like particles. In this work, we confirm a missing factor $1/2$ in this solution, which was first identified in Ref.~\cite{Pani:2012bp}. The corrected result has strange features that put questions on the power-counting strategy. We solve this problem by adding the next-to-leading order (NLO) contribution. Compared to the numerical results, the NLO solution reduces the percentage error of the LO solution by a factor of 2 for all important values of $r_g \mu$. Especially the percentage error is $\lesssim 10\%$ in the region of $r_g\mu \lesssim 0.35$. The NLO solution also has a compact form and could be used straightforwardly.Comment: 5 pages, 3 figures, Accepted by PR

Next-to-leading-order solution to Kerr-Newman black hole superradiance

The superradiant instabilities of Kerr-Newman black holes with charged or uncharged massive spin-0 fields are calculated analytically to the next-to-leading order in the limit of $\alpha\sim r_g \mu \ll 1$. A missing factor of $1/2$ in the previous leading-order result is identified. The next-to-leading order result has a compact form and is in good agreement with existing numerical calculations. The percentage error increases with $\alpha$, from a few percent for $\alpha\sim 0.1$ to about $50\%$ for $\alpha\sim 0.4$. Massive neutral scalars too heavy to be produced with Kerr black hole superradiance may exist in the superradiant region of Kerr-Newman black holes.Comment: 11 pages, 5 figures, 2 tables. Matches Physical Review D versio

2,4-Dihydr­oxy-N′-(3,4,5-trimethoxy­benzyl­idene)benzohydrazide

In the title compound, C17H18N2O6, the mol­ecule is slightly twisted, with a dihedral angle of 18.1 (2)° between the two benzene rings. In the crystal structure, mol­ecules are linked into a network by inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds. An intra­molecular O—H⋯O hydrogen bond is also present

TaCA: Upgrading Your Visual Foundation Model with Task-agnostic Compatible Adapter

Visual foundation models like CLIP excel in learning feature representations from extensive datasets through self-supervised methods, demonstrating remarkable transfer learning and generalization capabilities. A growing number of applications based on visual foundation models are emerging, including innovative solutions such as BLIP-2. These applications employ pre-trained CLIP models as upstream feature extractors and train various downstream modules to accomplish diverse tasks. In situations involving system upgrades that require updating the upstream foundation model, it becomes essential to re-train all downstream modules to adapt to the new foundation model, which is inflexible and inefficient. In this paper, we introduce a parameter-efficient and task-agnostic adapter, dubbed TaCA, that facilitates compatibility across distinct foundation models while ensuring enhanced performance for the new models. TaCA allows downstream applications to seamlessly integrate better-performing foundation models without necessitating retraining. We conduct extensive experimental validation of TaCA using different scales of models with up to one billion parameters on various tasks such as video-text retrieval, video recognition, and visual question answering. The results consistently demonstrate the emergent ability of TaCA on hot-plugging upgrades for visual foundation models. Codes and models will be available at https://github.com/TencentARC/TaCA

(Z)-4-[(Ethyl­amino)(furan-2-yl)methyl­idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

In the crystal of the title compound, C17H17N3O2, the mol­ecules exist in the keto–enamine form. The pyrazole ring is oriented at 10.59 (4) and 57.98 (5)° to the phenyl and furyl rings, respectively, and the dihedral angle between phenyl and furyl rings is 73.30 (11)°. An intra­molecular N—H⋯O hydrogen bond occurs between imino and carbonyl groups. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into supra­molecular chains along the b axis

ViT-Lens: Towards Omni-modal Representations

Though the success of CLIP-based training recipes in vision-language models, their scalability to more modalities (e.g., 3D, audio, etc.) is limited to large-scale data, which is expensive or even inapplicable for rare modalities. In this paper, we present ViT-Lens that facilitates efficient omni-modal representation learning by perceiving novel modalities with a pretrained ViT and aligning to a pre-defined space. Specifically, the modality-specific lens is tuned to project multimodal signals to the shared embedding space, which are then processed by a strong ViT that carries pre-trained image knowledge. The encoded multimodal representations are optimized toward aligning with the modal-independent space, pre-defined by off-the-shelf foundation models. A well-trained lens with a ViT backbone has the potential to serve as one of these foundation models, supervising the learning of subsequent modalities. ViT-Lens provides a unified solution for representation learning of increasing modalities with two appealing benefits: (i) Exploiting the pretrained ViT across tasks and domains effectively with efficient data regime; (ii) Emergent downstream capabilities of novel modalities are demonstrated due to the modality alignment space. We evaluate ViT-Lens in the context of 3D as an initial verification. In zero-shot 3D classification, ViT-Lens achieves substantial improvements over previous state-of-the-art, showing 52.0% accuracy on Objaverse-LVIS, 87.4% on ModelNet40, and 60.6% on ScanObjectNN. Furthermore, we enable zero-shot 3D question-answering by simply integrating the trained 3D lens into the InstructBLIP model without any adaptation. We will release the results of ViT-Lens on more modalities in the near future.Comment: 19 pages, 4 figures and 9 table

NASA-Approved Rotary Bioreactor Enhances Proliferation of Human Epidermal Stem Cells and Supports Formation of 3D Epidermis-Like Structure

The skin is susceptible to different injuries and diseases. One major obstacle in skin tissue engineering is how to develop functional three-dimensional (3D) substitute for damaged skin. Previous studies have proved a 3D dynamic simulated microgravity (SMG) culture system as a “stimulatory” environment for the proliferation and differentiation of stem cells. Here, we employed the NASA-approved rotary bioreactor to investigate the proliferation and differentiation of human epidermal stem cells (hEpSCs). hEpSCs were isolated from children foreskins and enriched by collecting epidermal stem cell colonies. Cytodex-3 micro-carriers and hEpSCs were co-cultured in the rotary bioreactor and 6-well dish for 15 days. The result showed that hEpSCs cultured in rotary bioreactor exhibited enhanced proliferation and viability surpassing those cultured in static conditions. Additionally, immunostaining analysis confirmed higher percentage of ki67 positive cells in rotary bioreactor compared with the static culture. In contrast, comparing with static culture, cells in the rotary bioreactor displayed a low expression of involucrin at day 10. Histological analysis revealed that cells cultured in rotary bioreactor aggregated on the micro-carriers and formed multilayer 3D epidermis structures. In conclusion, our research suggests that NASA-approved rotary bioreactor can support the proliferation of hEpSCs and provide a strategy to form multilayer epidermis structure

Production and Radioprotective Effects of Pyrroloquinoline Quinone

Pyrroloquinoline quinone (PQQ) was produced by fermentation of the Methylovorus sp. MP688 strain and purified by ion-exchange chromatography, crystallization and recrystallization. The yield of PQQ reached approximately 125 mg/L and highly pure PQQ was obtained. To determine the optimum dose of PQQ for radioprotection, three doses (2 mg/kg, 4 mg/kg, 8 mg/kg) of PQQ were orally administrated to the experimental animals subjected to a lethal dose of 8.0 Gy in survival test. Survival of mice in the irradiation + PQQ (4 mg/kg) group was found to be significantly higher in comparison with the irradiation and irradiation + nilestriol (10 mg/kg) groups. The numbers of hematocytes and bone marrow cells were measured for 21 days after sublethal 4 Gy gamma-ray irradiation with per os of 4 mg/kg of PQQ. The recovery of white blood cells, reticulocytes and bone marrow cells in the irradiation + PQQ group was faster than that in the irradiation group. Furthermore, the recovery of bone marrow cell in the irradiation + PQQ group was superior to that in irradiation + nilestriol group. Our results clearly indicate favourable effects on survival under higher lethal radiation doses and the ability of pyrroloquinoline quinine to enhance haemopoietic recovery after sublethal radiation exposure

Geometry and optics calibration of WFCTA prototype telescopes using star light

The Large High Altitude Air Shower Observatory project is proposed to study high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20 TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component of the LHAASO project, will be used to study energy spectrum and compositions of cosmic ray by measuring the total Cherenkov light generated by air showers and shower maximum depth. Two prototype telescopes have been in operation since 2008. The pointing accuracy of each telescope is crucial to the direction reconstruction of the primary particles. On the other hand the primary energy reconstruction relies on the shape of the Cherenkov image on the camera and the unrecorded photons due to the imperfect connections between photomultiplier tubes. UV bright stars are used as point-like objects to calibrate the pointing and to study the optical properties of the camera, the spot size and the fractions of unrecorded photons in the insensitive areas of the camera.Comment: 5 pages, 6 figures, submitted to Chinese Physics

miR-124 Suppresses Pancreatic Ductal Adenocarcinoma Growth by Regulating Monocarboxylate Transporter 1-Mediated Cancer Lactate Metabolism

Background/Aims: Increasing evidence shows that reprogramming of energy metabolism is a hallmark of cancer. Considering the emergence of microRNAs as crucial modulators of cancer, this study aimed to better understand the molecular mechanisms of miR-124 in regulating glycolysis in human pancreatic cancer. Methods: RT-PCR was used to investigate the expression of monocarboxylate transporters (MCTs) in pancreatic ductal adenocarcinoma (PDAC) patient samples and the PANC-1 cell line. A public database and immunochemistry were used for comprehensive analysis of MCT1 expression. The targeting of MCT1 by miR-124 was predicted by software and validated for the MCT1 3’-UTR by dual-luciferase reporter analysis. Cell proliferation, apoptosis, migration, xenografting, and the intracellular pH and L-lactate levels were assessed. Hypoxia-inducible factor-α (HIF-1α) and lactate dehydrogenase A (LDH-A) expression levels were determined by RT-PCR and western blotting. Results: MCT1 expression was higher in PDAC tissue than in normal tissue. Inhibition of MCT1 affected lactate metabolism, resulting in a higher intracellular pH and less proliferation of PANC-1 cells. MCT1 was the target gene of miR-124. In in vitro experiments, miR-124 inhibited the glycolytic activity of PANC-1 cells by targeting MCT1, further decreasing the tumor phenotype by increasing the intracellular pH through LDH-A and HIF-1α. In in vivo experiments, overexpression of miR-124 and silencing of MCT1 significantly inhibited tumor growth. Conclusion: miR-124 inhibits the progression of PANC-1 by targeting MCT1 in the lactate metabolic pathway. Our findings provide novel evidence for further functional studies of miR-124, which might be useful for future therapeutic approaches to PDAC