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Identification of coexistence of biological and non-biological aerosol particles with DAPI (4′,6-diamidino-2-phenylindole) stain

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Particuology 2023年第1期72卷 49-57页

作者： Ting Liu Jiaquan Zhang Junji Cao Han Zheng Changlin Zhan Hongxia Liu Lili Zhang Kai Xiao Shan Liu Dong Xiang Daizhou Zhang School of Environmental Science and Engineering Hubei Polytechnic UniversityHubei Key Laboratory of Mine Environmental Pollution Control and RemediationHuangshi 435003China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China School of Computer Science and Artificial Intelligence Wuhan University of TechnologyWuhan 430063China Faculty of Environmental and Symbiotic Sciences Prefectural University of KumamotoKumamoto 862-8502Japan

The fluorescent dye 4′,6-diamidino-2-phenylindole (DAPI) has been widely used to stain microorganisms in various environment media. We applied DAPI fluorescence enumeration to airborne microorganisms and found that non-biological particles, including organic compounds, minerals, and soot, were also visible upon exposure to UV excitation under fluorescence microscope. Using laboratory-prepared biological particles as the control, we investigated the feasibility of identifying both biological and non-biological particles in the same sample with DAPI staining. We prepared biological (bacterial, fungi, and plant detritus) and non-biological (biochar, soot, mineral, metal, fly ash, salt) particles in the laboratory and enumerated the particles and their mixture with DAPI. We found that mineral particles were transparent, and biochar, soot, metals and fly ash particles were black under a filter set at excitation 350/50 nm and emission 460/50 nm bandpass (DAPI-BP), while biological particles were blue, as expected. Particles of the water-soluble salts NaCl and (NH_(4))_(2)SO_(4) were yellow under a filter set at excitation 340–380 nm and emission 425 nm long pass (DAPI-LP). Case studies with samples of dustfall, atmospheric aerosols and surface soils could allow for the quantification of the relative number of different types of particles and particles with organic matter or salt coating as well. Fluorescence enumeration with DAPI stain is thus able to identify the co-existence of biological and non-biological particles in the air, at least to the extent of those examined in this study.

关键词： 4',6-diamidino-2-phenylindole(DAPI) Biological particles Nonbiological particles Atmospheric aerosols

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Reconstruction of the singularity-free gravity via Raychaudhuri equations

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The European Physical Journal C 2024年第7期84卷 1-12页

作者： Gadbail, Gaurav N. Arora, Simran Sahoo, P. K. Bamba, Kazuharu Department of Mathematics Birla Institute of Technology and Science-Pilani Hyderabad India Department of Mathematics CDOE Chandigarh University Punjab India Faculty of Symbiotic Systems Science Fukushima University Fukushima Japan

We study the bounce cosmology to construct a singularity-free $$f({\mathcal {R}})$$ model using the reconstruction technique. The formulation of the $$f({\mathcal {R}})$$ model is based on the Raychaudhari equation, a key element employed in reconstructed models to eliminate singularities. We explore the feasibility of obtaining stable gravitational Lagrangians, adhering to the conditions $$f_{{\mathcal {R}}}>0$$ and $$f_{{\mathcal {R}}{\mathcal {R}}}>0$$ . Consequently, both models demonstrate stability, effectively avoiding the Dolgov–Kawasaki instability. Our assessment extends to testing the reconstructed model using energy conditions and the effective equation-of-state (EoS). Our findings indicate that the reconstructed super-bounce model facilitates the examination of a singularity-free accelerating universe for both phantom and non-phantom phases. However, in the case of the reconstructed oscillatory bounce model, two scenarios are considered with $$\omega =-\,1/3$$ and $$\omega =-\,2/3$$ . While the model proves suitable for studying a singular-free accelerating universe in the $$\omega =-\,1/3$$ case, it fails to demonstrate such behavior under energy conditions for the $$\omega =-\,2/3$$ scenario. The reconstructed models accommodate early-time bouncing behavior and late-time cosmic acceleration within a unified framework.

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Gaussian Process Approach for Model-Independent Reconstruction of f(Q) Gravity with Direct Hubble Measurements

arXiv

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arXiv 2024年

作者： Gadbail, Gaurav N. Mandal, Sanjay Sahoo, P.K. Department of Mathematics Birla Institute of Technology and Science-Pilani Hyderabad Campus Hyderabad500078 India Faculty of Symbiotic Systems Science Fukushima University Fukushima960-1296 Japan

The increase of discrepancy in the standard procedure to choose the arbitrary functional form of the Lagrangian f(Q) motivates us to solve this issue in modified theories of gravity. In this regard, we investigate the Gaussian process (GP), which allows us to eliminate this issue in a f(Q) model-independent way. In particular, we use the 58 Hubble measurements coming from cosmic chronometers and the radial Baryon acoustic oscillations (BAO) to reconstruct H(z) and its derivatives H′(z), H′′(z), which resulting lead us to reconstruct region of f(Q), without any assumptions. The obtained mean curve along ΛCDM constant in the reconstructed region follows a quadratic behavior. This motivates us to propose a new f(Q) parametrization, i.e., f(Q) = −2Λ + ϵQ2, with the single parameter ϵ, which signifies the deviations from ΛCDM cosmology. Further, we probe the widely studied power-law and exponential f(Q) models against the reconstructed region and can improve the parameter spaces significantly compared with observational analysis. In addition, the direct Hubble measurements, along with the reconstructed f(Q) function, allow the H0 tension to be alleviated. © 2024, CC BY.

关键词： Cosmology

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Reconstruction of the scalar field potential in nonmetricity gravity through Gaussian processes

arXiv

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arXiv 2024年

作者： Gadbail, Gaurav N. Mandal, Sanjay Sahoo, P.K. Bamba, Kazuharu Department of Mathematics Birla Institute of Technology and Science-Pilani Hyderabad Campus Hyderabad500078 India Faculty of Symbiotic Systems Science Fukushima University Fukushima960-1296 Japan

The accelerated expansion of the universe has been widely confirmed, posing challenges to the standard ΛCDM model, particularly the cosmological coincidence problem. This has motivated the exploration of modified gravity theories, including nonmetricity gravity, which explains cosmic acceleration without dark energy. In this work, we incorporate a quintessence scalar field into the nonmetricity framework to model both inflation and late-time acceleration. Employing the Gaussian process method with a square exponential kernel, we reconstruct the scalar field potential, V(), from observational Hubble data sets coming from cosmic chronometers (CC) as well as from the method of radial baryon acoustic oscillations (BAO) in a model-independent approach. This approach allows us to obtain a suitable quintessence scalar field model that aligns with the observational Hubble data under the framework of power-law nonmetricity gravity. Additionally, we compare our reconstructed potential with power-law scalar field potentials, revealing that these models show better agreement with the observational data, providing new insights into the dynamics of the universe. In contrast, we find that the early dark energy has minimal effect on the present-time accelerated expansion of the universe. © 2024, CC BY.

关键词： Dark energy

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Morphology And Germinability of Scrippsiella Trochoidea Cysts in Acidified Sediments of Hypoxic Zones

SSRN

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SSRN 2024年

作者： Kim, Young-Ok Ichinomiya, Mutsuo Choi, Jungmin Baek, Ju-Wook Kim, Sung-Han Lee, Jae Seong Ocean Climate Response & Ecosystem Research Department Korea Institute of Ocean Science and Technology Busan49111 Korea Republic of Faculty of Environmental Symbiotic Science Prefectural University of Kumamoto Kumamoto862-8502 Japan Marine Environment Research Department Korea Institute of Ocean Science and Technology Busan49111 Korea Republic of

This study investigates calcareous cysts of Scrippsiella trochoidea, with a focus on morphological changes from spiny to naked types in surface sediments of hypoxic zones. Cyst type abundance and bottom environments were compared at two stations representing hypoxic and normoxic conditions. Germination tests, simulating in situ pH conditions, were conducted to elucidate differences in germinability between spiny and naked cysts. At the hypoxic station, pH values reached a minimum of 7.2 in September, coinciding with high bottom water temperatures and low dissolved oxygen levels. Significant differences in cyst abundances were observed: naked and intermediate cysts dominated the hypoxic station, while spiny cysts were more abundant at the normoxic station. Both cyst types showed similar decreases in germinability under low pH conditions. Morphological changes in ungerminated cysts, such as cytoplasm degradation and wall thickening, occurred under acidified conditions. Further research is needed to examine the combined effects of hypoxia and acidification. © 2024, The Authors. All rights reserved.

关键词： Surficial sediments

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Thermodynamic and shadow analysis of Dehnen type dark matter Halo corrected Schwarzschild black hole surrounded by thin disk

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The European Physical Journal C 2025年第6期85卷 1-15页

作者： Rani, Shamaila Jawad, Abdul Heydari-Fard, Malihe Zafar, Usman Institute for Theoretical Physics and Cosmology Zhejiang University of Technology Hangzhou China Department of Mathematics COMSATS University Islamabad Lahore-Campus Lahore Pakistan Department of Physics The University of Qom Qom Iran Faculty of Symbiotic Systems Science Fukushima University Fukushima Japan

In this work, the Schwarzschild black hole immersed in a Dehnen-type dark matter halo is considered for analyzing its various properties such as thermodynamics (through various entropies), shadow and optical appearance. For this purpose, we analytically describe the thermodynamic characteristics of BHs, like heat capacity and Helmholtz and Gibbs free energy, to study the local and global stability of such BHs by utilizing different entropy models. We also investigate the sparsity of Hawking radiations and found that the halo core radius and density are key factors determining the sparsity of this black hole. Astrophysical BHs are believed to be surrounded by luminous accretion disks. By considering the geometrically and optically thin accretion flow around the Schwarzschild black hole immersed in a Dehnen-type dark matter halo, we investigate the shadow and optical appearance of such a black hole. We show that in addition to the structure of the space-time geometry, the black hole’s image depends on the location of the accretion disk. By analyzing three specific radii, we determine the impact of direct emissions, photon rings, and lensing rings on the total intensity. The results indicate that direct emissions dominate the intensity while lensing and photon rings contribute minimally.

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f (Q, T) gravity: From early to late-time cosmic acceleration

arXiv

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arXiv 2023年

作者： Das, Surajit Mandal, Sanjay Department of Physics Birla Institute of Technology and Science - Pilani Hyderabad Campus Telangana Hyderabad500078 India Faculty of Symbiotic Systems Science Fukushima University Fukushima960-1296 Japan

In this article, we explore the comprehensive narrative of cosmic evolution within a cosmological framework by utilizing a novel form of gravity known as generalized symmetric teleparallel gravity, denoted as f (Q, T) gravity. Here, Q represents the non-metricity scalar, while T denotes the trace of the energy-momentum tensor. We present and analyze two distinct f (Q, T) cosmological models, each characterized by its unique Lagrangian. Our investigation delves into the cosmological parameters of these models, scrutinizing various energy conditions, examining the inflationary dynamics of the early universe through scalar field formulations, and probing the mysterious nature of dark energy using statefinder diagnostics and (ω − ω′) phase space analysis. Ultimately, our findings offer a comprehensive account of cosmic evolution, spanning from the early universe to its late-time evolution. © 2023, CC BY.

关键词： Phase space methods

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Reconstruction of the singularity-free f(R) gravity via Raychaudhuri equations

arXiv

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arXiv 2024年

作者： Gadbail, Gaurav N. Arora, Simran Sahoo, P.K. Bamba, Kazuharu Department of Mathematics Birla Institute of Technology and Science-Pilani Hyderabad Campus Hyderabad500078 India Department of Mathematics CDOE Chandigarh University Punjab 140413 India Faculty of Symbiotic Systems Science Fukushima University Fukushima960-1296 Japan

We study the bounce cosmology to construct a singularity-free f(R) model using the reconstruction technique. The formulation of the f(R) model is based on the Raychaudhari equation, a key element employed in reconstructed models to eliminate singularities. We explore the feasibility of obtaining stable gravitational Lagrangians, adhering to the conditions fR > 0 and fRR > 0. Consequently, both models demonstrate stability, effectively avoiding the Dolgov-Kawasaki instability. Our assessment extends to testing the reconstructed model using energy conditions and the effective equation-of-state (EoS). Our findings indicate that the reconstructed super-bounce model facilitates the examination of a singularity-free accelerating universe for both phantom and non-phantom phases. However, in the case of the reconstructed oscillatory bounce model, two scenarios are considered with ω = −1/3 and ω = −2/3. While the model proves suitable for studying a singular-free accelerating universe in the ω = −1/3 case, it fails to demonstrate such behavior under energy conditions for the ω = −2/3 scenario. The reconstructed models accommodate early-time bouncing behavior and late-time cosmic acceleration within a unified framework. © 2024, CC BY.

关键词： Cosmology

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Basic Approach to Estimation of Blood Oxygen Saturation Using an RGB Color Camera without Infrared Light 4

Basic Approach to Estimation of Blood Oxygen Saturation Usin...

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4th IEEE Global Conference on Life sciences and Technologies, LifeTech 2022

作者： Yoshizawa, Makoto Sugita, Norihiro Tanaka, Akira Togashi, Atsushi Kaji, Isao Yambe, Tomoyuki Tohoku University Center for Promotion of Innovation Strategy Sendai Japan Tohoku University Graduate School of Engineering Sendai Japan Fukushima University Faculty of Symbiotic Systems Science Fukushima Japan Shizuoka Institute of Science and Technology Faculty of Informatics Fukuroi Japan Sendai Foundation for Applied Information Sciences Sendai Japan

ISBN: (纸本)9781665419048

A method for estimating SPO2 using only an ordinary RGB color camera without using infrared light required by general pulse oximeters has been developed. In the method, first, three video pulse waves based on RGB video signals obtained by photographing the palm with a white LED light source were acquired as accurately as possible, and then their AC and DC components were obtained. SPO2 was estimated from the interrelationship among the three types of ratios. In the experiment, healthy 91 participants were made to hold their breath for 20s to create changes in SPO2. True values of SPO2 obtained from the fingertip photoelectric pulse wave meter was compared with estimated values from the palm video image. The results performed from five trials of cross-validation demonstrated that the multiple regression model was superior to the optimization method for absorption coefficients. © 2022 IEEE.

关键词： Oxygen

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The Stability of Anisotropic Compact Stars Influenced by Dark Matter under Teleparallel Gravity: An Extended Gravitational Deformation Approach

arXiv

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arXiv 2024年

作者： Pradhan, Sneha Bhar, Piyali Mandal, Sanjay Sahoo, P.K. Bamba, Kazuharu Department of Mathematics Birla Institute of Technology and Science-Pilani Hyderabad Campus Hyderabad500078 India Department of Mathematics Government General Degree College Singur West Bengal Hooghly712409 India Faculty of Symbiotic Systems Science Fukushima University Fukushima960-1296 Japan

In our investigation, we pioneer the development of geometrically deformed strange stars within the framework of teleparallel gravity theory through gravitational decoupling via the complete geometric deformation (CGD) technique. The significant finding is the precise solution for deformed strange star (SS) models achieved through the vanishing complexity factor scenario. Further, we introduce the concept of space-time deformation caused by dark matter (DM) content in DM haloes, leading to perturbations in the metric potentials gtt and grr components. Mathematically, this DM-induced deformation is achieved through the CGD method, where the decoupling parameter α governs the extent of DM influence. To validate our findings, we compare our model predictions with observational constraints, including GW190814 (with a mass range of 2.5 − 2.67M☉) and neutron stars (NSTRs) such as EXO (formula presented), 4U 1608-52 (formula presented), and PSR J0952-0607 (formula presented). Our investigation delves into the stability of the model by considering causality conditions, Herrera’s Cracking Method, the adiabatic index, and the Harrison-Zeldovich-Novikov criterion. We demonstrate that the developed model mimics a wide range of recently observed pulsars. To emphasize its compatibility, we highlight the predicted mass and radius in tabular form by varying both the parameters α and ζ1. Notably, our findings are consistent with the observation of gravitational waves from the first binary merger event. Furthermore, we compare our results with those obtained for a slow-rotating configuration. In addition to this, we discuss the moment of inertia using the Bejger-Haensel approach in this formulation. © 2024, CC BY.

关键词： Dark Matter

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