bluuebunny/crossref_metadata_2025 huggingface dataset:
Gaza: The Right to Life or the Right to Health During COVID-19
Authors: Qwaider Ayman
Published: January 2023

The coastal enclaved Gaza Strip has been particularly vulnerable even prior to the onset of the COVID-19 pandemic, due to years of Israeli blockade and successive wars which have devastated Gaza’s economy, education, health, and livelihood. This meant that preventive measures such as social distancing and self-quarantine were impossible in a place with an estimated population of 5,800 people per square kilometre. This chapter briefly reviews Gaza’s pre-pandemic health sector, explores the barriers to adequate responses to the pandemic and highlights some of its socio-political and health implications on Gaza’s vulnerable population. Considering Israeli military aggression against Gaza in May 2021, this chapter argues that an analysis of the medical and health response to a global pandemic should address the context of a systematic de-development process in the Gaza Strip.
The Street for Transport
Authors: Riggs William
Published: January 2023

Chapter 3 extends the discussion on the history of street and discuss the first experience of the street—the street for transport. It provides a primer in how planning and engineering for walking and biking is done extending on the prior chapters which covered background and history and including key terms, best practice in multimodal design, and livability measurement techniques. The chapter reviews specific geometries and examples of how standard car lanes now have 12+’ and some of the places and reasons why some streets differ. It goes over examples of curbs and street interventions as a way of illustrating that corridors for transportation do not need have a fixed definition, providing an overview of the transportation planning and engineering field that is built on in subsequent chapters.
Fabrication of a dual-focus artificial compound eye with improved imaging based on modified microprinting and air-assisted deformation
Authors: Li Jiang , Wang Wenjun , Fu Zuoli , Zhu Ruixiang , Huang Yuxiang
Published: January 2023

Natural compound eyes inspire the development of artificial optical devices that feature a large field of view and fast motion detection. However, the imaging of artificial compound eyes dramatically depends on many microlenses. The single focal length of the microlens array significantly limits the actual applications of artificial optical devices, like distinguishing objects at different distances. In this study, a curved artificial compound eye for a microlens array with different focal lengths was fabricated by inkjet printing and air-assisted deformation. By adjusting the space of the microlens array, secondary microlenses were created between intervals of the primary microlens. The diameter/height of the primary and secondary microlens arrays are 75/25 µm and 30/9 µm, respectively. The planar-distributed microlens array was transformed into a curved configuration using air-assisted deformation. Compared with adjusting the curved base to distinguish objects at different distances, the reported technique features simplicity and is easy to operate. The applied air pressure can be used to tune the field of view of the artificial compound eye. The microlens arrays with different focal lengths could distinguish the objects at different distances without additional components. When the external objects move a small distance, they can be detected by the microlens arrays due to their different focal lengths. It could effectively improve the motion perception of the optical system. Moreover, the focusing and imaging performances of the fabricated artificial compound eye were further tested. The compound eye combines the advantages of monocular eyes and compound eyes, holding great potential for developing advanced optical devices with a large field of view and automatic variable-focus imaging.
GRIN-lens-based in-line digital holographic microscopy
Authors: Khorshad Ali Akbar , Devaney Nicholas
Published: January 2023

In-line digital holographic microscopy (DHM) provides three-dimensional images with large fields of view and depths of field and micrometer-scale resolution, using a compact, cost-effective, and stable setup. Here, we develop the theoretical background and experimentally demonstrate an in-line DHM based on a gradient-index (GRIN) rod lens. In addition, we develop a conventional pinhole-based in-line DHM with different configurations to compare the resolution and image quality of both GRIN-based and pinhole-based systems. We show that in a high-magnification regime, where the sample is positioned near a source that produces spherical waves, our optimized GRIN-based setup provides better resolution (
∼1.38µm
). Furthermore, we employed this microscope to holographically image dilute polystyrene micro-particles with diameters of 3.0 and 2.0 µm. We investigated the effect of light source–detector and sample–detector distances on the resolution, by both theory and experiment. Our theoretical and experimental results are in good agreement.
Hyperspectral full polarization imaging system based on spatial modulation
Authors: Zhang Lei , Yang Yu , Zhao Shuai , Chen Tianci , Yu Kaiyang , Wang Keyi , Xie Chengfeng , Wang Mengyu , Cai Bolin
Published: January 2023

The hyperspectral full polarization imaging system (HFPIS) based on spatial modulation and liquid crystal tunable filter (LCTF) can modulate the polarization information of the target into the interferogram by means of interference imaging. It has the advantage of rapid imaging of the hyperspectral full polarization information from the target, and has good real time imaging and practicality. Through the spectroscopic imaging mode of a Savart prism, the corresponding interference optical path and imaging system are designed, including a beam expander, spatial modulator, LCTF, focusing system, and imaging sensor. This system can extract the different information from the target and demodulate it so as to obtain the hyperspectral polarization image. The experiment shows that the HFPIS can reveal the texture, contour, and other details of the target in the fog, and has obvious advantages over the traditional intensity imaging methods.
Scattering characteristics of a terahertz Bessel vortex beam by 3D dielectric-coated targets
Authors: Li Haiying , Chen Xinmiao , Zhao Lei , Meng Xiangshuai , Wu Tao
Published: January 2023

In order to explore the application of terahertz (THz) vortex beams in 3D dielectric-coated target detection and imaging, scattering characteristics of a THz Bessel vortex beam by 3D dielectric-coated conducting targets are investigated in terms of the combination of planewave angular spectrum expansion and a physics optics method in this paper. The accuracy of the proposed method is verified by comparing with the results of FEKO software. The scattering characteristics of a THz Bessel vortex beam by several typical 3D dielectric-coated targets are analyzed in detail. The effects of the beam parameters (topological charge, half-cone angle, incident angle and frequency) are discussed. The results show that with an increase of topological charge, the magnitude of the radar cross section (RCS) decreases, and the maximum value moves away from the incident direction gradually; the distribution of the RCS does not keep symmetry as the incident angle increases, and the corresponding orbital angular momentum state distribution of the far-scattered field is distorted remarkably.
Evaluation of color vision related quality of life changes due to cataract surgery
Authors: Jansone-Langina Zane , Ozolinsh Maris
Published: January 2023

Questionnaires have been used as research tools to provide a standardized approach to assess quality of life at various time periods and populations. However, literature shows only a few articles about self-reported color vision changes. Our aim was to evaluate the subjective patient feelings before and after cataract surgery and compare the results with a color vision test result. Our method was as follows: 80 cataract patients filled out a modified color vision questionnaire and performed the Farnsworth–Munsell 100 Hue Color Vision Test (FM100) before, two weeks, and six months after cataract surgery. We analyzed the correlations between these two types of results, which reveal that FM100 hue performance and subjective perception improved after surgery. Additionally, subjective patient questionnaire scores correlate well with the FM100 test results before and two weeks after the cataract surgery, but this effect decreased with longer follow-up times. We conclude that subjective color vision changes can only be noticed at longer periods after the cataract surgery. Health care professionals can use this questionnaire to better understand the subjective feelings of patients and monitor their color vision sensitivity changes.
Image quality assessment procedure for holographic displays based on exact numerical reconstruction of computer-generated holograms
Authors: Higashida Ryo , Miura Masato , Yamaguchi Yuta , Funabashi Nobuhiko , Aoshima Ken-ichi , Machida Kenji , Yamaguchi Masahiro
Published: January 2023

We proposed a technique for the computer-based reconstruction of computer-generated holograms and evaluation of the reconstructed 3D image quality. The proposed method mimics how the eye’s lens works, thus allowing for viewing position and eye focus adjustments. The angular resolution of the eye was used to output reconstructed images with the requisite resolution, and a reference object was used to normalize the images. Such data processing enables the numerical analysis of image quality. By comparing the reconstructed images with the original image with incoherent illumination, the image quality was quantitatively evaluated.
Accurate luminance and chromaticity controls of digital colors using CIE-based RGBW algorithms
Authors: Tang Ni , Wang Jiyong , Zhang Baofeng , Chen Hao , Qiu Min
Published: January 2023

Emerging high brightness of color displays and high signal-to-noise ratio of camera sensors require an addition of white (W) subpixels to ordinary red, green, and blue (RGB) subpixels. Conventional algorithms converting RGB signals to RGBW signals suffer from reduced chroma of highly saturated colors and complicated coordinate transformations between RGB color spaces and color spaces defined by the Commission internationale de l’éclairage (CIE). In this work, we developed a complete set of RGBW algorithms to digitally code a color in the CIE-based color spaces, making complicated processes including color space transformations and white balancing become largely unnecessary. The analytic three-dimensional gamut can be obtained so that the maximal hue and luminance of a digital frame could be simultaneously obtained. Exemplary applications in adaptive controls of the colors of an RGB display in accordance with the W component of background light validate our theory. The algorithm opens an avenue toward accurate manipulations of digital colors for RGBW sensors and displays.
Perception of brown with variation in center chromaticity and surround luminance
Authors: Shinomori Keizo , Werner John S.
Published: January 2023

Brown is a contrast color that depends on complex combinations of chromatic and achromatic signals. We measured brown perception with variations in chromaticity and luminance in center-surround configurations. In Experiment 1, the dominant wavelength and saturation in terms ofS-cone stimulation were tested with five observers in a fixed surround luminance (60cd/m2). A paired-comparison task required the observer to select the better exemplar of brown in one of two, simultaneously presented, stimuli (1.0° center diameter; annulus of 9.48° outer-diameter). In Experiment 2, the same task was tested with five observers in which surround luminance was varied (from 13.1 to99.6cd/m2) for two center chromaticities. The results were a set of win–loss ratios for each stimulus combination and converted toZ-scores. An ANOVA did not reveal a significant main effect of the observer factor but revealed a significant interaction with red/green (a∗) [but not with the dominant wavelength and theS-cone stimulation (orb∗)]. Experiment 2 revealed observer variation in interactions with surround luminance andS-cone stimulation. The averaged data plotted in 1976 L∗a∗b∗color space indicate that highZ-score values widely distribute in the area ofa∗from 5 to 28 andb∗over 6. The balance of the strength between yellowness and blackness differs among observers owing to the amount of induced blackness required for the best brown.
Using equiluminance settings to estimate the cardinal chromatic directions for individuals
Authors: Richardson Alex J. , Lee Kassandra R. , Crognale Michael A. , Webster Michael A.
Published: January 2023

Color information is processed by the retina and lateral geniculate along principal dimensions known as the cardinal directions of color space. Normal differences in spectral sensitivity can impact the stimulus directions that isolate these axes for individual observers and can arise from variation in lens and macular pigment density, photopigment opsins, photoreceptor optical density, and relative cone numbers. Some of these factors that influence the chromatic cardinal axes also impact luminance sensitivity. We modeled and empirically tested how well tilts on the individual’s equiluminant plane are correlated with rotations in the directions of their cardinal chromatic axes. Our results show that, especially for the SvsLM axis, the chromatic axes can be partially predicted by luminance settings, providing a potential procedure for efficiently characterizing the cardinal chromatic axes for observers.
Correlation of multimode fields in atmospheric turbulence
Authors: Baykal Yahya , Gökçe Muhsin Caner , Ata Yalçın , Gerçekcioğlu Hamza
Published: January 2023

Multimode field correlations are evaluated in atmospheric turbulence. High order field correlations are special cases of the results that we obtained in this paper. Field correlations are presented for various numbers of multimodes, various multimode contents of the same number of modes, and various high order modes versus the diagonal distance from various receiver points, source size, link length, structure constant, and the wavelength. Our results will be of help especially in the design of heterodyne systems operating in turbulent atmosphere and fiber coupling efficiency in systems employing multimode excitation.
Metasurface supporting quasi-BIC for optical trapping and Raman-spectroscopy of biological nanoparticles
Authors: Hasan Md Rabiul , Hellesø Olav Gaute
Published: January 2023

Optical trapping combined with Raman spectroscopy have opened new possibilities for analyzing biological nanoparticles. Conventional optical tweezers have proven successful for trapping of a single or a few particles. However, the method is slow and cannot be used for the smallest particles. Thus, it is not adapted to analyze a large number of nanoparticles, which is necessary to get statistically valid data. Here, we propose quasi-bound states in the continuum (quasi-BICs) in a silicon nitride (Si3N4) metasurface to trap smaller particles and many simultaneously. The quasi-BIC metasurface contains multiple zones with high field-enhancement (‘hotspots’) at a wavelength of 785 nm, where a single nanoparticle can be trapped at each hotspot. We numerically investigate the optical trapping of a type of biological nanoparticles, namely extracellular vesicles (EVs), and study how their presence influences the resonance behavior of the quasi-BIC. It is found that perturbation theory and a semi-analytical expression give good estimates for the resonance wavelength and minimum of the potential well, as a function of the particle radius. This wavelength is slightly shifted relative to the resonance of the metasurface without trapped particles. The simulations show that the Q-factor can be increased by using a thin metasurface. The thickness of the layer and the asymmetry of the unit cell can thus be used to get a high Q-factor. Our findings show the tight fabrication tolerances necessary to make the metasurface. If these can be overcome, the proposed metasurface can be used for a lab-on-a-chip for mass-analysis of biological nanoparticles.
Manipulating dispersive wave emission via temporal sinusoidal phase modulation
Authors: Li Haozhe , Wang Zhiteng , Xie Zhongxiang , Fan Dianyuan , Zhang Lifu
Published: January 2023

We report the dispersive wave (DW) emission from the Gaussian pulse with temporal sinusoidal phase (TSP) modulation. The TSP-induced chirp can enhance or cancel the chirp generated by self-phase modulation by properly selecting the modulation parameters of TSP, which can influence the nonlinear propagation of the TSP-modulated pulse. It is shown that the TSP can effectively control the resonant frequency and energy conversion efficiency of the DW emission. We give a modified phase-matching condition to predict the resonant frequencies, which agree with the simulation results obtained by numerically solving the nonlinear Schrödinger equation. The enhanced conversion efficiency of the DWs can be increased up to 28% with only TSP modulation. Our results can extend the application of temporal phase modulation technology for wavelength conversion, and broadband supercontinuum generation.
Simulation of the generation conditions and influence parameters of a self-mode-locked erbium-doped fiber laser
Authors: Hu Zeqiu , Wu Duanduan , Lin Wei , Li Zhe , Dai Shixun
Published: January 2023

The generation conditions and influence parameters of self-mode-locked pulses in fiber lasers are theoretically studied. By establishing the simulation model of a self-mode-locked erbium-doped fiber laser (EDFL) with a high-concentration erbium-doped fiber-based saturable absorber (SA), the effect of gain saturation energy, orientation angles of the polarizer and analyzer with respect to the fast axis of the fiber, laser coupling output ratio, dispersion value and condition on the self-mode-locked pulse generation and performances are quantitatively analyzed. The result shows that a low laser coupling output ratio can help the formation of a self-mode-locked pulse. The anomalous dispersion self-mode-locked EDFL has a relative high tolerance for dispersion value change but requires high gain energy for mode-locked pulse generation. The normal dispersion one possesses a low mode-locked pulse formation threshold but is relative polarization sensitive. This study is of important reference significance for the investigation of mode-locked fiber lasers.
Photon color conversion enhancement of colloidal quantum dots inserted into a subsurface laterally-extended GaN nano-porous structure in an InGaN/GaN quantum-well template
Authors: Chen Chen-Hua , Kuo Sheng-Yang , Feng His-Yu , Li Zong-Han , Yang Shaobo , Wu Shung-Hsiang , Hsieh Hao-Yu , Lin Yu-Sheng , Lee Yueh-Chi , Chen Wei-Cheng , Wu Ping-Hsiu , Chen Jun-Chen , Huang Yang-Yi , Lu You-Jui , Kuo Yang , Lin Chia-Feng , Yang C. C.
Published: January 2023

To improve the color conversion performance, we study the nanoscale-cavity effects on the emission efficiency of a colloidal quantum dot (QD) and the Förster resonance energy transfer (FRET) from quantum well (QW) into QD in a GaN porous structure (PS). For this study, we insert green-emitting QD (GQD) and red-emitting QD (RQD) into the fabricated PSs in a GaN template and a blue-emitting QW template, and investigate the behaviors of the photoluminescence (PL) decay times and the intensity ratios of blue, green, and red lights. In the PS samples fabricated on the GaN template, we observe the efficiency enhancements of QD emission and the FRET from GQD into RQD, when compared with the samples of surface QDs, which is attributed to the nanoscale-cavity effect. In the PS samples fabricated on the QW template, the FRET from QW into QD is also enhanced. The enhanced FRET and QD emission efficiencies in a PS result in an improved color conversion performance. Because of the anisotropic PS in the sample surface plane, the polarization dependencies of QD emission and FRET are observed.
Synthetic dispersion interferometry for relative atmospheric pressure sensing
Authors: Uittenbosch Hugo , Kliebisch Oliver , Lorbeer Raoul-Amadeus , Mahnke Peter
Published: January 2023

We present a modified version of the two-arm, two-color, single second harmonic generation heterodyne dispersion interferometer, as introduced by Irby et. al. [Rev. Sci. Instrum. 70, 699 (1999) 10.1063/1.1149489]. The amount of optical elements is reduced and digital in-phase and quadrature demodulation is used to retrieve the phase shift from a single photodetector signal. The intrinsic system noise and drift for this device are analyzed by measuring the Allan deviation. We investigate the use of this device for relative atmospheric pressure measurement. Relative pressure measurements are performed in a pressure chamber and referenced against a piezoresistive pressure transceiver to demonstrate the concept. It was found that the deviation was less than 150 Pa and an error estimation has been derived.
Matching entropy based disparity estimation from light field data
Authors: Shi Ligen , Liu Chang , He Di , Zhao Xing , Qiu Jun
Published: January 2023

A major challenge for matching-based disparity estimation from light field data is to prevent mismatches in occlusion and smooth regions. An effective matching window satisfying three characteristics: texture richness, disparity consistency, and anti-occlusion should be able to prevent mismatches to some extent. According to these characteristics, we propose matching entropy in the spatial domain of the light field to measure the amount of correct information in a matching window, which provides the criterion for matching window selection. Based on matching entropy regularization, we establish an optimization model for disparity estimation with a matching cost fidelity term. To find the optimum, we propose a two-step adaptive matching algorithm. First, the region type is adaptively determined to identify occluding, occluded, smooth, and textured regions. Then, the matching entropy criterion is used to adaptively select the size and shape of matching windows, as well as the visible viewpoints. The two-step process can reduce mismatches and redundant calculations by selecting effective matching windows. The experimental results on synthetic and real data show that the proposed method can effectively improve the accuracy of disparity estimation in occlusion and smooth regions and has strong robustness for different noise levels. Therefore, high-precision disparity estimation from 4D light field data is achieved.
Integrated O- and C-band silicon-lithium niobate Mach-Zehnder modulators with 100 GHz bandwidth, low voltage, and low loss
Authors: Valdez Forrest , Mere Viphretuo , Wang Xiaoxi , Mookherjea Shayan
Published: January 2023

Broadband integrated thin-film lithium niobate (TFLN) electro-optic modulators (EOM) are desirable for optical communications and signal processing in both the O-band (1310 nm) and C-band (1550 nm). To address these needs, we design and demonstrate Mach-Zehnder (MZ) EOM devices in a hybrid platform based on TFLN bonded to foundry-fabricated silicon photonic waveguides. Using a single silicon lithography step and a single bonding step, we realize MZ EOM devices which cover both wavelength ranges on the same chip. The EOM devices achieve 100 GHz EO bandwidth (referenced to 1 GHz) and about 2-3 V.cm figure-of-merit (

V
π

L

) with low on-chip optical loss in both the O-band and C-band.
Hiding images in noise
Authors: Johnson Steven , McMillan Alex , Frick Stefan , Rarity John , Padgett Miles
Published: January 2023

A limitation of free-space optical communications is the ease with which the information can be intercepted. This limitation can be overcome by hiding the information within background optical noise. We demonstrate the transfer of images over free-space using a photon-pair source emitting two correlated beams. One of these beams contains image information, to which noise is added, and the other correlated beam is used as a heralding trigger so that the intended recipient can differentiate this image signal from the background noise. The system uses spontaneous parametric down-conversion to create photon-pairs with a wide spectral bandwidth and a gated intensified camera to extract the image from the background noise. The high-dimensionality of the image space means that the information content can be many bits per detected photon, whereas the heralding photon can be restricted to a single spatial-mode within a secure fiber which itself could be protected against interception by traditional low-dimensionality quantum key protocols.
Versatile all-digital transport-of-intensity based wavefront sensor and adaptive optics using a DMD
Authors: Singh Keshaan , Dudley Angela , Forbes Andrew
Published: January 2023

Measuring and correcting wavefront aberrations is an important process in a wide variety of disciplines, from ophthalmology, laser cutting, and astronomy to free-space communication and microscopy, and always relies on measuring intensities to infer phase. One approach is to use the transport-of-intensity as a means for phase retrieval, exploiting the connection between observed energy flow in optical fields and their wavefronts. Here we present a simple scheme, using a digital micro-mirror device (DMD), to perform angular spectrum propagation and extract the wavefront of optical fields at various wavelengths, dynamically, with high resolution and tuneable sensitivity. We verify the capability of our approach by extracting common Zernike aberrations, turbulent phase screens, and lens phases under static and dynamic conditions at multiple wavelengths and polarizations. We use this setup for adaptive optics, correcting distortion using a second DMD to apply conjugate phase modulation. We observed effective wavefront recovery under a variety of conditions which allowed for convenient real-time adaptive correction in a compact arrangement. Our approach provides an all-digital system that is versatile, cheap, fast, accurate, broadband and polarization invariant.
Laser cooling by over 7 K in Yb-doped ZBLAN fibers with high-power pumping at atmospheric pressure
Authors: Xie Qingnan , Rao Daxing , Yu Guangze , Li Fujian , Guan Xianghe , Feng Wei , Ji Lailin , Cui Yong , Gao Yanqi , Sui Zhan
Published: January 2023

Anti-Stokes fluorescence (ASF) cooling has been demonstrated to be a viable method for balancing the waste heat produced in gain materials. In addition, radiation-balanced fiber lasers and amplifiers at atmospheric pressure have recently been developed. Here, we evaluate the cooling characteristics in a long section of a Yb-doped ZBLAN fiber with high pump power. The fiber has a 200-µm-diameter core and is doped with 3 wt. % Yb3+. As indicated by a thermal camera, cooling by over 7 K below ambient temperature was achieved by core pumping at 1030 nm. The temperature drop distribution at multiple measurement points in the fiber was evaluated with a maximum pump power of tens of watts. The results demonstrate the excellent ASF cooling performance of Yb-doped ZBLAN fibers. This study has great significance for the development of high-power radiation-balanced fiber lasers.
Octave-spanning soliton microcomb in silica microdisk resonators
Authors: Gu Jiaxin , Li Xuan , Qi Kai , Pu Keren , Li Zhixuan , Zhang Fan , Li Tao , Xie Zhenda , Xiao Min , Jiang Xiaoshun
Published: January 2023

We demonstrate a chip-based octave-spanning soliton microcomb in a whispering gallery mode microresonator platform. By fabricating a silica microdisk resonator and optimizing its dispersion with dry etching, we achieve an octave-spanning single-soliton microcomb with a repetition rate of ∼670 GHz at an optical pump power of 162.6 mW. Also, two dispersive waves at the end of the spectrum are observed to extend the comb spectral range and improve the comb power.
Lumped-element models of THz metasurfaces based on split-ring resonators and their complementary form
Authors: Papari Gian Paolo , Nivas Jijil JJ , Hu Meilin , Amoruso Salvatore , Andreone Antonello
Published: January 2023

Realistic lumped-element circuits describing split-ring resonator metasurfaces and their complementary forms are presented. To consider the polarization dependence, we exploit the symmetry of the meta-atoms with respect to the impinging electric field. Our approach enables to describe the circuital architectures including the effect of Ohmic dissipation in real metasurfaces. Lumped-element models describes in a simple way features like enhanced transmission and deep absorption that are observed in metasurfaces and complementary metasurfaces based on split-ring resonators.
The Classification of Surfaces via Normal Curves
Authors: Ayaz Fethi , Kegel Marc , Mohnke Klaus
Published: January 2023

We present a simple proof of the surface classification theorem using normal curves. This proof is analogous to Kneser’s and Milnor’s proof of the existence and uniqueness of the prime decomposition of 3-manifolds. In particular, we do not need any invariants from algebraic topology to distinguish surfaces.
Genotype–environment interactions determine microbiota plasticity in the sea anemone Nematostella vectensis
Authors: Baldassarre Laura , Reitzel Adam M. , Fraune Sebastian
Published: January 2023

Most multicellular organisms harbor microbial colonizers that provide various benefits to their hosts. Although these microbial communities may be host species- or even genotype-specific, the associated bacterial communities can respond plastically to environmental changes. In this study, we estimated the relative contribution of environment and host genotype to bacterial community composition in Nematostella vectensis, an estuarine cnidarian. We sampled N. vectensis polyps from 5 different populations along a north–south gradient on the Atlantic coast of the United States and Canada. In addition, we sampled 3 populations at 3 different times of the year. While half of the polyps were immediately analyzed for their bacterial composition by 16S rRNA gene sequencing, the remaining polyps were cultured under laboratory conditions for 1 month. Bacterial community comparison analyses revealed that laboratory maintenance reduced bacterial diversity by 4-fold, but maintained a population-specific bacterial colonization. Interestingly, the differences between bacterial communities correlated strongly with seasonal variations, especially with ambient water temperature. To decipher the contribution of both ambient temperature and host genotype to bacterial colonization, we generated 12 clonal lines from 6 different populations in order to maintain each genotype at 3 different temperatures for 3 months. The bacterial community composition of the same N. vectensis clone differed greatly between the 3 different temperatures, highlighting the contribution of ambient temperature to bacterial community composition. To a lesser extent, bacterial community composition varied between different genotypes under identical conditions, indicating the influence of host genotype. In addition, we identified a significant genotype x environment interaction determining microbiota plasticity in N. vectensis. From our results we can conclude that N. vectensis-associated bacterial communities respond plastically to changes in ambient temperature, with the association of different bacterial taxa depending in part on the host genotype. Future research will reveal how this genotype-specific microbiota plasticity affects the ability to cope with changing environmental conditions.
Pyfectious: An individual-level simulator to discover optimal containment policies for epidemic diseases
Authors: Mehrjou Arash , Soleymani Ashkan , Abyaneh Amin , Bhatt Samir , Schölkopf Bernhard , Bauer Stefan
Published: January 2023

Simulating the spread of infectious diseases in human communities is critical for predicting the trajectory of an epidemic and verifying various policies to control the devastating impacts of the outbreak. Many existing simulators are based on compartment models that divide people into a few subsets and simulate the dynamics among those subsets using hypothesized differential equations. However, these models lack the requisite granularity to study the effect of intelligent policies that influence every individual in a particular way. In this work, we introduce a simulator software capable of modeling a population structure and controlling the disease’s propagation at an individualistic level. In order to estimate the confidence of the conclusions drawn from the simulator, we employ a comprehensive probabilistic approach where the entire population is constructed as a hierarchical random variable. This approach makes the inferred conclusions more robust against sampling artifacts and gives confidence bounds for decisions based on the simulation results. To showcase potential applications, the simulator parameters are set based on the formal statistics of the COVID-19 pandemic, and the outcome of a wide range of control measures is investigated. Furthermore, the simulator is used as the environment of a reinforcement learning problem to find the optimal policies to control the pandemic. The obtained experimental results indicate the simulator’s adaptability and capacity in making sound predictions and a successful policy derivation example based on real-world data. As an exemplary application, our results show that the proposed policy discovery method can lead to control measures that produce significantly fewer infected individuals in the population and protect the health system against saturation.
Improving the validity of neuroimaging decoding tests of invariant and configural neural representation
Authors: Soto Fabian A. , Narasiwodeyar Sanjay
Published: January 2023

Many research questions in sensory neuroscience involve determining whether the neural representation of a stimulus property is invariant or specific to a particular stimulus context (e.g., Is object representation invariant to translation? Is the representation of a face feature specific to the context of other face features?). Between these two extremes, representations may also be context-tolerant or context-sensitive. Most neuroimaging studies have used operational tests in which a target property is inferred from a significant test against the null hypothesis of the opposite property. For example, the popular cross-classification test concludes that representations are invariant or tolerant when the null hypothesis of specificity is rejected. A recently developed neurocomputational theory suggests two insights regarding such tests. First, tests against the null of context-specificity, and for the alternative of context-invariance, are prone to false positives due to the way in which the underlying neural representations are transformed into indirect measurements in neuroimaging studies. Second, jointly performing tests against the nulls of invariance and specificity allows one to reach more precise and valid conclusions about the underlying representations, particularly when the null of invariance is tested using the fine-grained information from classifier decision variables rather than only accuracies (i.e., using the decoding separability test). Here, we provide empirical and computational evidence supporting both of these theoretical insights. In our empirical study, we use encoding of orientation and spatial position in primary visual cortex as a case study, as previous research has established that these properties are encoded in a context-sensitive way. Using fMRI decoding, we show that the cross-classification test produces false-positive conclusions of invariance, but that more valid conclusions can be reached by jointly performing tests against the null of invariance. The results of two simulations further support both of these conclusions. We conclude that more valid inferences about invariance or specificity of neural representations can be reached by jointly testing against both hypotheses, and using neurocomputational theory to guide the interpretation of results.
A real-time regional model for COVID-19: Probabilistic situational awareness and forecasting
Authors: Engebretsen Solveig , Diz-Lois Palomares Alfonso , Rø Gunnar , Kristoffersen Anja Bråthen , Lindstrøm Jonas Christoffer , Engø-Monsen Kenth , Kamineni Meghana , Hin Chan Louis Yat , Dale Ørjan , Midtbø Jørgen Eriksson , Stenerud Kristian Lindalen , Di Ruscio Francesco , White Richard , Frigessi Arnoldo , de Blasio Birgitte Freiesleben
Published: January 2023

The COVID-19 pandemic is challenging nations with devastating health and economic consequences. The spread of the disease has revealed major geographical heterogeneity because of regionally varying individual behaviour and mobility patterns, unequal meteorological conditions, diverse viral variants, and locally implemented non-pharmaceutical interventions and vaccination roll-out. To support national and regional authorities in surveilling and controlling the pandemic in real-time as it unfolds, we here develop a newregionalmathematical and statistical model. The model, which has been in use in Norway during the first two years of the pandemic, is informed by real-time mobility estimates from mobile phone data and laboratory-confirmed case and hospitalisation incidence. To estimate regional and time-varying transmissibility, case detection probabilities, and missed imported cases, we developed a novel sequential Approximate Bayesian Computation method allowing inference in useful time, despite the high parametric dimension. We test our approach on Norway and find that three-week-ahead predictions are precise and well-calibrated, enabling policy-relevant situational awareness at a local scale. By comparing the reproduction numbers before and after lockdowns, we identify spatially heterogeneous patterns in their effect on the transmissibility, with a stronger effect in the most populated regions compared to the national reduction estimated to be 85% (95% CI 78%-89%). Our approach is the first regional changepoint stochastic metapopulation model capable of real time spatially refined surveillance and forecasting during emergencies.
Modelling ribosome kinetics and translational control on dynamic mRNA
Authors: Dykeman Eric C.
Published: January 2023

The control of protein synthesis and the overall levels of various proteins in the cell is critical for achieving homoeostasis. Regulation of protein levels can occur at the transcriptional level, where the total number of messenger RNAs in the overall transcriptome are controlled, or at the translational level, where interactions of proteins and ribosomes with the messenger RNA determine protein translational efficiency. Although transcriptional control of mRNA levels is the most commonly used regulatory control mechanism in cells, positive-sense single-stranded RNA viruses often utilise translational control mechanisms to regulate their proteins in the host cell. Here I detail a computational method for stochastically simulating protein synthesis on a dynamic messenger RNA using the Gillespie algorithm, where the mRNA is allowed to co-translationally fold in response to ribosome movement. Applying the model to the test case of the bacteriophage MS2 virus, I show that the models ability to accurately reproduce experimental measurements of coat protein production and translational repression of the viral RNA dependant RNA polymerase at high coat protein concentrations. The computational techniques reported here open up the potential to examine the infection dynamics of a ssRNA virus in a host cell at the level of the genomic RNA, as well as examine general translation control mechanisms present in polycistronic mRNAs.
Exploration or exploitation? A study on equity incentive design, dynamic decision making, and economic consequences
Authors: Zhang Qianqian , Jiang Chunzi , Zhang Xiaomei
Published: January 2023

We examine whether equity incentive can encourage exploratory innovation from the perspective of dynamic innovation decision-making process. Using the data of equity incentives in China’s listed companies from 2006 to 2017, we construct exploratory intensity of innovation strategy and analyze the impact of equity incentive on corporation exploratory innovation strategy from both the cross-sectional and time-series perspectives. We find a positive relationship between the vesting period and explorative innovation strategy in the cross-sectional dimension. However, the time-series analyses show that the innovation strategy becomes less explorative and more exploitative after the third period during equity incentive. The effect of vesting period is stronger in smaller firms and during the non-financial crisis period. Further analysis reveals that followed by the changes in innovation strategy, the growth rates of innovation output and firm performance also decline.
Optimized inferences of finite population mean using robust parameters in systematic sampling
Authors: Shaheen Nazia , Qureshi Muhammad Nouman , Alamri Osama Abdulaziz , Hanif Muhammad
Published: January 2023

In this article, we have proposed a generalized estimator for mean estimation by combining the ratio and regression methods of estimation in the presence of auxiliary information using systematic sampling. We incorporated some robust parameters of the auxiliary variable to obtain precise estimates of the proposed estimator. The mathematical expressions for bias and mean square error of proposed the estimator are derived under large sample approximation. Many other generalized ratio and product-type estimators are obtained from the proposed estimator using different choices of scalar constants. Some special cases are also discussed in which the proposed generalized estimator reduces to the usual mean, classical ratio, product, and regression type estimators. Mathematical conditions are obtained for which the proposed estimator will perform more precisely than the challenging estimators mentioned in this article. The efficiency of the proposed estimator is evaluated using four populations. Results showed that the proposed estimator is efficient and useful for survey sampling in comparison to the other existing estimators.
Sero-prevalence and associated factors of sexually transmitted infections among youth-friendly services Attendees
Authors: Ambaye Erdachew , Ormago Moges Desta , Ali Musa Mohammed
Published: January 2023

Background

Worldwide, more than one million peoples acquire sexually transmitted infections (STIs). The burden of STIs and the youth awareness level on the transmission of STIs is under investigated in Sidama Regional State.

Objective

To determine the seroprevalence of STIs such as hepatitis B surface antigen (HBsAg), Anti-hepatitis C virus (HCV) antibodies, Human Immunodeficiency virus (HIV) seroprevalence, and syphilis and to determine associated factors among youth-friendly services Attendees at selected health facilities in Hawassa city, Ethiopia.

Methods

A multicenter cross-sectional study was conducted among 416 randomly selected youth attending youth-friendly services at selected health facilities from May to August 2021. To collect the background characteristics of participants an interviewer-administered questionnaire was used. Blood samples were collected, processed, and tested using Advanced Quality One Step rapid colloidal gold immunochromatographic assay for detection of antibodies for syphilis and hepatitis C virus infection, and hepatitis B virus surface antigen. For the diagnosis of syphilis Rapid Plasma Reagin was also used. HIV1/2 STAT PAK, HIV1/2/O ABON and HIV1/2 SD Bioline were used for testing antibodies for HIV infection. Data entry and analysis were performed using Statistical Package for the Social Sciences (SPSS) version 20.0 software. A crude and adjusted odds ratio with a 95% confidence interval (CI) was computed to identify associated factors.

Results

The overall seroprevalence of STIs was 11.5% (48/422), with a 95% CI: (8.7−14.9). Out of the 48 positive results, the proportions of HBsAg, Anti-HCV, HIV, and syphilis were 56.3% (27/48), 27.1% (13/48), 10.4% (5/48), and 6.3% (3/48) respectively. Out of 416 participants, 17.1% responded that it is safe to have sex without using a condom. The Odds of developing STI among female participants, participants who did not identify alcohol intake as a risk factor for STIs, and those who engaged in transactional sex were (AOR = 2.989: 95% CI: 1.27, 7.02), and (AOR = 2.393, 95% CI: 1.18, 4.81) and practice of transactional sex (AOR = 5.527, 95% CI: 1.62, 18.75).

Conclusions

STIs are common among youth-friendly services Attendee in Hawassa city The overall STI was significantly associated with sex (females), not able to identify alcohol intake as a risk factor, and practice of transactional sex. High number of (n = 289, 69.5%) participants think that the use of condoms is not effective in preventing STIs and they engage in sexual activity without using condoms.
Critical behavior and the Kibble-Zurek mechanism in a musical phase transition
Authors: Din Huay , Berezovsky Jesse
Published: January 2023

We investigate the critical phenomena emerging from a statistical mechanics model of musical harmony on a three-dimensional (3D) lattice, and the resulting structure of the ordered phase. In this model, each lattice site represents a tone, with nearest neighbors interacting via the perception of dissonance between them. With dissonance assumed to be an octave-wise periodic function of pitch difference, this model is a 3D XY system with the same symmetry and dimensionality as superfluid helium and models of the cosmological axion field. We use numerical simulation to observe a phase transition from disordered sound to ordered arrangements of musical pitches as a parameter analogous to the temperature is quenched towards zero. We observe the divergence of correlation length and relaxation time at the phase boundary, consistent with the critical exponents in similar systems. Furthermore, the quenched low-temperature phase of these systems displays topological defects in the form of vortex strings that thread throughout the system volume. We observe the formation of these vortex strings in accordance with the Kibble-Zurek mechanism, and discuss the structure of these vortex strings in the context of the theory of musical harmony, finding both similarities to established music theory, and uncovering new avenues to explore.