bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotational magic conditions for ultracold molecules in the presence of Raman and Rayleigh scattering
Authors: Kotochigova Svetlana , Guan Qingze , Tiesinga Eite , Scarola Vito , DeMarco Brian , Gadway Bryce
Published: June 2024

Molecules have vibrational, rotational, spin-orbit and hyperfine degrees of freedom or quantum states, each of which responds in a unique fashion to external electromagnetic radiation. The control over superpositions of these quantum states is key to coherent manipulation of molecules. For example, the better the coherence time the longer quantum simulations can last. The important quantity for controlling an ultracold molecule with laser light is its complex-valued molecular dynamic polarizability. Its real part determines the tweezer or trapping potential as felt by the molecule, while its imaginary part limits the coherence time. Here, our study shows that efficient trapping of a molecule in its vibrational ground state can be achieved by selecting a laser frequency with a detuning on the order of tens of GHz relative to an electric-dipole-forbidden molecular transition. Close proximity to this nearly forbidden transition allows to create a sufficiently deep trapping potential for multiple rotational states without sacrificing coherence times among these states from Raman and Rayleigh scattering. In fact, we demonstrate that magic trapping conditions for multiple rotational states of the ultracold 23Na87Rb polar molecule can be created.
Defects analysis of radiation damage mechanism for IMM triple-junction solar cell under 1 MeV electron irradiation
Authors: Zhang Shuyi , Zhuang Yu , Aierken Abuduwayiti , Song Qiaogang , Zhang Qin , Wang Qian , Dou Youbo , Zhang Qiuli
Published: June 2024

Inverted metamorphic (IMM) GaInP/GaAs/InGaAs rigid triple-junction solar cells under 1 MeV electron irradiation at various fluences were investigated theoretically. By fitting the electrical and optical parameters of solar cells with experimental results at the fluence ranging from 1 × 1014 e cm−2 to 1 × 1015 e cm−2, basic trap information was obtained, and then the minority carrier lifetime and trap concentration of sub-cells at various fluences were also calculated. The defects analysis of IMM triple-junction solar cell presented in this work could help understanding the radiation damage mechanism of 1 MeV electron irradiation.
Wave packet dynamics of entangled q-deformed states
Authors: Rohith M , Anupama S , Sudheesh C
Published: June 2024

This paper explores the wave packet dynamics of a math-type q-deformed field interacting with atoms in a Kerr-type nonlinear medium. The primary focus is on the generation and dynamics of entanglement using the q-deformed field, with the quantification of entanglement accomplished through the von Neumann entropy. Two distinct initial q-deformed states, the q-deformed Fock state, and the q-deformed coherent state, are investigated. The entanglement dynamics reveal characteristics of periodic, quasi-periodic, and chaotic behaviour. Non-deformed initial states display wave packet near revivals and fractional revivals in entanglement dynamics while introducing q-deformation eliminates these features. The q-deformation significantly influences wave packet revivals and fractional revivals, with even a slight introduction causing their disappearance. For large values of q, the entanglement dynamics exhibit a chaotic nature. In the case of a beam splitter-type interaction applied to the initial deformed Fock state, an optimal deformation parameter q is identified, leading to maximum entanglement exceeding the non-deformed scenario.
Time-fractional lorenz type chaotic systems with asymmetric gaussian uncertainty: series solutions via extended He-Mohand algorithm in fuzzy-caputo sense
Authors: Qayyum Mubashir , Ahmad Efaza
Published: June 2024

In this paper, modeling and analysis of 3D fuzzy-fractional Lorenz type systems is presented. System under-consideration includes classical Lorenz, Chen and Burke-Shaw chaotic systems. Asymmetrical Gaussian fuzzy logic with fractional calculus is applied to model complex systems with intricate patterns. The focus of this study is fuzzy-fractional modeling and simulations. For solution purpose, a hybrid perturbation method is introduced where standard homotopy perturbation method (HPM) is enhanced by incorporating Mohand transform in fuzzy-Caputo sense. This hybrid mechanism provides an efficient way to find solutions in fuzzy-fractional environment. Validity of obtained solutions is checked by computing residual errors, which ultimately confirms the convergence of applied methodology. The dynamical behavior of fuzzy-fractional chaotic models is analyzed through various 2-3D plots to represent the chaotic regions as well unpredictable trajectories at both upper and lower bounds. Fuzzy membership functions of 3D models at different values of fractional derivative are also demonstrated through 2D plots. Analysis reveals that extended hybrid methodology proves to be a valuable tool for researchers dealing with nonlinear chaotic fractional systems with fuzzy characteristics.
Squeezing equivalence of quantum harmonic oscillators under different frequency modulations
Authors: S Coelho Stanley , Queiroz Lucas , Alves Danilo T
Published: June 2024

The papers by Janszky and Adam [Phys. Rev. A 46, 6091 (1992)] and Chen et al [Phys. Rev. Lett.
104, 063 002 (2010)] are examples of works where one can find the following equivalences: quantum harmonic oscillators subjected to different time-dependent frequency modulations, during a certain time interval τ, exhibit exactly the same final null squeezing parameter (r

f
= 0). In the present paper, we discuss a more general case of squeezing equivalence, where the final squeezing parameter can be non-null (r

f
≥ 0). We show that when the interest is in controlling the forms of the frequency modulations, but keeping free the choice of the values of r

f
and τ, this in general demands numerical calculations to find these values leading to squeezing equivalences (a particular case of this procedure recovers the equivalence found by Jansky and Adams). On the other hand, when the interest is not in previously controlling the form of these frequencies, but rather r

f
and τ (and also some constraints, such as minimization of energy), one can have analytical solutions for these frequencies leading to squeezing equivalences (particular cases of this procedure are usually applied in problems of shortcuts to adiabaticity, as done by Chen et al). In this way, this more general squeezing equivalence discussed here is connected to recent and important topics in the literature as, for instance, generation of squeezed states and the obtaining of shortcuts to adiabaticity.
Compact polarization-insensitive microwave metamaterial absorber with hepta-band characteristics
Authors: Garg Supriya , Jain Prince , Garg Sahil , Sharma Bhavya , Das Gourab , Sardana Neha , Kumar Sanjeev , Singh Arun Kumar
Published: June 2024

This paper presents an ultra-thin and compact metamaterial absorber (MMA) capable of achieving near-perfect absorption peaks across the C, X, Ku, and K frequency bands. The MMA structure features a modified metallic plus-shaped resonator surrounded by symmetric L-shaped resonators within a compact size of 13 × 13 mm2. The absorber exhibits seven absorption peaks at different resonant frequencies including 4.23, 6.48, 10.62, 12.92, 14.03, 17.39, and 18.11 GHz. With a thickness of 0.0225λ and a compact size of 0.1833λ at the lowest frequency, the absorber offers remarkable thinness and compactness. Different characteristics of the absorber, such as normalized impedance, surface current distribution, and electric field distribution, are also examined. The polarization-insensitive behavior of the MMA is assessed through absorption and reflection responses under different polarization and incident angles. The Equivalent Circuit Model (ECM) of the metamaterial absorber is also designed to accurately represent the MMA unit cell across all resonant frequencies. Experimental validation of the proposed MMA confirms its performance consistency with simulation results. The proposed MMA design holds potential for applications in defense, detection, and sensing. The sensing ability of the MMA is analyzed using simulations at different refractive index values.
Protection of entanglement in two independently decohering qubits via local prior and post parity-time symmetry operations
Authors: Li Wen-Juan , Leng Yang
Published: June 2024

Protection of entanglement of two qubits undergoing two independent amplitude damping channels using a local parity-time (

PT

) symmetric operation is exactly studied. First, the explicit expressions of concurrence quantifying the entanglement of two qubits with both local

PT

symmetric operation and two amplitude damping channels are obtained. Then, we give two schemes, i.e. prior and post

PT

symmetric operations, to show the performance of

PT

symmetric operation on entanglement dynamics of two qubits. By investigation, we find that the effect of prior

PT

symmetric operation schemes on the protection of entanglement of two qubits in the double channel case is superior to that of the single channel case. Conversely, the effect of post

PT

symmetric operation scheme on the protection of entanglement of two qubits in the single channel case is better than that in the double channel case. In other words, the local

PT

symmetric operation approach may have potential applications in combating amplitude damping decoherence.
Laser-accelerated MeV-scale collimated electron bunch from a near-critical plasma of a liquid jet target
Authors: Ivanov K A , Shulyapov S A , Gorlova D A , Tsygvintsev I P , Krivokorytov M S , Tsymbalov I N , Volkov R V , Savelev A B
Published: June 2024

Generation of a collimated electron bunch with energy of a few MeV is demonstrated experimentally during propagation of 1 TW 10 Hz femtosecond laser radiation through a near-critical plasma formed from a micrometer-scale liquid jet (ethanol) target by ablation and boring with an intense nanosecond pulse. Hydrodynamic and particle-in-cell simulations reveal the evolution of the plasma cloud and help to identify the acceleration mechanism, which is related to self-modulated laser Wakefield acceleration during nonlinear propagation of laser radiation through plasma. The measured bunch divergence is at the level of 0.04 rad with high shot-to-shot stability. The total charge of the particles with energy above 1.6 MeV was estimated at ∼15 pC. The simplicity and robustness of the target design allows for enhanced pulse repetition rate with suppressed debris formation.
The ring-shaped shadow of a rotating naked singularity with a complete photon sphere*
Authors: Wang 王 Mingzhi 明智 , Guo 郭 Guanghai 广海 , Yan 闫 Pengfei 鹏飞 , Chen 陈 Songbai 松柏 , Jing 荆 Jiliang 继良
Published: June 2024

We investigate the shadows of the Konoplya-Zhidenko naked singularity. In the spacetime of the Konoplya-Zhidenko naked singularity, not only an unstable retrograde light ring (LR) but also an unstable prograde LR exists, leading to the formation of a complete photon sphere (PS). Due to the absence of an event horizon, a dark disc-shaped shadow does not appear; instead, a ring-shaped shadow is observed. The ring-shaped shadow appears as an infinite number of relativistic Einstein rings in the image of the naked singularity. For some parameter values, only the unstable retrograde LR exists, resulting in an incomplete unstable PS and thus giving rise to an arc-shaped shadow for the Konoplya-Zhidenko naked singularity. The shadow of the Konoplya-Zhidenko naked singularity gradually shifts to the right as the rotation parameter a increases and gradually becomes smaller as the deformation parameter

increases. Moreover, stable LRs and stable photon spherical orbits can exist in the Konoplya-Zhidenko naked singularity spacetime, but they have no effect on the image of the naked singularity. This study demonstrates that a rotating naked singularity can exhibit not only an arc-shaped shadow but also a ring-shaped shadow.
Comprehensive analysis of uncertainty quantification for the 58Ni(n, p)58Co reaction cross section*
Authors: Choudhary Mahesh , Sharma Aman , Singh Namrata , Upadhyay Mahima , Dubey Punit , Gandhi A. , Hingu Akash , Mishra G , De Sukanya , Danu L. S. , Kumar Ajay , Thomas R. G. , Sood Saurav , Prasad Sajin , Mukherjee S. , Ruskov I. N. , Kopatch Yu. N. , Kumar A.
Published: June 2024

In this study, we measured the 58Ni(n, p)58Co reaction cross section with neutron energies of 1.06, 1.86, and 2.85 MeV. The cross section was measured using neutron activation techniques and γ-ray spectroscopy, and it was compared with cross section data available in the EXFOR. Furthermore, we calculated the covariance matrix of the measured cross section for the aforementioned nuclear reaction. The uncertainties of the theoretical calculation for 58Ni(n, p)58Co reaction cross section were calculated via Monte Carlo method. In this study, we used uncertainties in the optical model and level density parameters to calculate uncertainties in the theoretical cross sections. The theoretical calculations were performed by using TALYS-1.96. In this study, we aim to analyze the effect of uncertainties of the nuclear model input as well as different experimental variables used to obtain the values of reaction cross section.
A distributed, high-channel-count, implanted bidirectional system for restoration of somatosensation and myoelectric control
Authors: Lambrecht Joris M , Cady Sedona R , Peterson Erik J , Dunning Jeremy L , Dinsmoor David A , Pape Forrest , Graczyk Emily L , Tyler Dustin J
Published: June 2024

Objective. We intend to chronically restore somatosensation and provide high-fidelity myoelectric control for those with limb loss via a novel, distributed, high-channel-count, implanted system. Approach. We have developed the implanted Somatosensory Electrical Neurostimulation and Sensing (iSens®) system to support peripheral nerve stimulation through up to 64, 96, or 128 electrode contacts with myoelectric recording from 16, 8, or 0 bipolar sites, respectively. The rechargeable central device has Bluetooth® wireless telemetry to communicate to external devices and wired connections for up to four implanted satellite stimulation or recording devices. We characterized the stimulation, recording, battery runtime, and wireless performance and completed safety testing to support its use in human trials. Results. The stimulator operates as expected across a range of parameters and can schedule multiple asynchronous, interleaved pulse trains subject to total charge delivery limits. Recorded signals in saline show negligible stimulus artifact when 10 cm from a 1 mA stimulating source. The wireless telemetry range exceeds 1 m (direction and orientation dependent) in a saline torso phantom. The bandwidth supports 100 Hz bidirectional update rates of stimulation commands and data features or streaming select full bandwidth myoelectric signals. Preliminary first-in-human data validates the bench testing result. Significance. We developed, tested, and clinically implemented an advanced, modular, fully implanted peripheral stimulation and sensing system for somatosensory restoration and myoelectric control. The modularity in electrode type and number, including distributed sensing and stimulation, supports a wide variety of applications; iSens® is a flexible platform to bring peripheral neuromodulation applications to clinical reality. ClinicalTrials.gov ID NCT04430218.
Identifying behavioral links to neural dynamics of multifiber photometry recordings in a mouse social behavior network
Authors: Chen Yibo , Chien Jonathan , Dai Bing , Lin Dayu , Chen Zhe Sage
Published: June 2024

Objective. Distributed hypothalamic-midbrain neural circuits help orchestrate complex behavioral responses during social interactions. Given rapid advances in optical imaging, it is a fundamental question how population-averaged neural activity measured by multi-fiber photometry (MFP) for calcium fluorescence signals correlates with social behaviors is a fundamental question. This paper aims to investigate the correspondence between MFP data and social behaviors. Approach: We propose a state-space analysis framework to characterize mouse MFP data based on dynamic latent variable models, which include a continuous-state linear dynamical system and a discrete-state hidden semi-Markov model. We validate these models on extensive MFP recordings during aggressive and mating behaviors in male-male and male-female interactions, respectively. Main results: Our results show that these models are capable of capturing both temporal behavioral structure and associated neural states, and produce interpretable latent states. Our approach is also validated in computer simulations in the presence of known ground truth. Significance: Overall, these analysis approaches provide a state-space framework to examine neural dynamics underlying social behaviors and reveals mechanistic insights into the relevant networks.
A boundary element method of bidomain modeling for predicting cellular responses to electromagnetic fields
Authors: Czerwonky David M , Aberra Aman S , Gomez Luis J
Published: June 2024

Objective. Commonly used cable equation approaches for simulating the effects of electromagnetic fields on excitable cells make several simplifying assumptions that could limit their predictive power. Bidomain or ‘whole’ finite element methods have been developed to fully couple cells and electric fields for more realistic neuron modeling. Here, we introduce a novel bidomain integral equation designed for determining the full electromagnetic coupling between stimulation devices and the intracellular, membrane, and extracellular regions of neurons. Approach. Our proposed boundary element formulation offers a solution to an integral equation that connects the device, tissue inhomogeneity, and cell membrane-induced E-fields. We solve this integral equation using first-order nodal elements and an unconditionally stable Crank–Nicholson time-stepping scheme. To validate and demonstrate our approach, we simulated cylindrical Hodgkin–Huxley axons and spherical cells in multiple brain stimulation scenarios. Main Results. Comparison studies show that a boundary element approach produces accurate results for both electric and magnetic stimulation. Unlike bidomain finite element methods, the bidomain boundary element method does not require volume meshes containing features at multiple scales. As a result, modeling cells, or tightly packed populations of cells, with microscale features embedded in a macroscale head model, is simplified, and the relative placement of devices and cells can be varied without the need to generate a new mesh. Significance. Device-induced electromagnetic fields are commonly used to modulate brain activity for research and therapeutic applications. Bidomain solvers allow for the full incorporation of realistic cell geometries, device E-fields, and neuron populations. Thus, multi-cell studies of advanced neuronal mechanisms would greatly benefit from the development of fast-bidomain solvers to ensure scalability and the practical execution of neural network simulations with realistic neuron morphologies.
Nonlinear MHD modeling of soft β limits in W7-AS
Authors: Ramasamy R. , Aleynikova K. , Nikulsin N. , Hindenlang F. , Holod I. , Strumberger E. , Hoelzl M. ,   the JOREK team
Published: June 2024

An important question for the outlook of stellarator reactors is their robustness against pressure driven modes, and the underlying mechanism behind experimentally observed soft β limits. Towards building a robust answer to these questions, simulation studies are presented using a recently derived reduced nonlinear MHD model. First, the initial model implementation is extended to capture fluid compression by including the influence of parallel flows. Linear benchmarks of a (2, 1) tearing mode in W7-AS geometry, and interchange modes in a finite β, net-zero current carrying stellarator with low magnetic shear are then used to demonstrate the modeling capabilities. Finally, a validation study is conducted on experimental reconstructions of finite β W7-AS discharges. In agreement with past experimental analysis, it is shown that (i) the MHD activity is resistive, (ii) a soft β limit is observed, when the plasma resistivity approaches the estimated experimental value, and (iii) low n MHD activity is observed at intermediate β values, particularly a nonlinearly dominant (2, 1) mode. The MHD activity is mild, explaining the soft β limit, because the plasma volume remains separated into distinct sub-volumes in which field lines are ergodically confined. For the assumed transport parameters, the enhanced perpendicular transport along stochastic magnetic field lines can be overcome with the experimental heating power. The limitations in the current modeling are described, alongside an outlook for characterizing the quasi-steady state operational limit in W7-AS and other devices in more detail in future work.
Study on the influence of gap dependent error on the cryogenic permanent magnet undulator performance
Authors: Sun Shuchen , Guo Qing , Li Xiaoyu , Lu Huihua , Li Yuhui , Sun Yajun , Zhao Shutao , Zhang Lei , Li Zhiqiang , Chen Wan , Zhang Xiangzhen
Published: June 2024

The mass production of the first stage of HEPS (High Energy
Photon Source) is approaching its final stage. 6 CPMUs (cryogenic
permanent magnet undulators) have been manufactured, with four
successfully finalizing the tuning of the magnetic field. To ensure
radiation performance, HEPS's CPMUs enforce stringent phase error
protocols. Moreover, the contraction properties at cryogenic
temperature lead to a decrease in phase error after cooling. In the
process of CPMU commissioning, a technique for forecasting the
change of magnetic errors from room to cryogenic temperature was
discovered and studied, as will be demonstrated in this paper.
On the BEM solution of convection–diffusion type equations involving variable convective coefficients
Authors: Fendoğlu Hande , Bozkaya Canan , Tezer-Sezgin Munevver
Published: June 2024

In this study, numerical solutions of the unsteady convection–diffusion type equations of variable convective coefficients are investigated by two effective techniques alternative to direct boundary element method (BEM). That is, the domain boundary element and the dual reciprocity BEMs with the fundamental solution of convection–diffusion equation are used in space to transform the governing differential equations into equivalent integral equations while a backward finite difference scheme is utilized in time discretization. The fruitfulness of these combined techniques are shown by the implementation of the techniques for some widely investigated fluid dynamics problems. In fact, the lid-driven cavity flow is solved, and precise results are attained as benchmarks for assessing the accuracy of the aforementioned methods. Further, the application of the methods is extended for the natural convection flow which is governed mainly by the convection–diffusion type equations accompanied by the velocity components as variable convective coefficients. The obtained numerical results reveal that the domain BEM which uses the fundamental solution of convection–diffusion equation captures the characteristics and physical advancement of the fluid flow quite well at various combined values of the problem physical parameters.
Observation and analysis of positive leader re-illumination in a 10 m ultra-high voltage transmission line gap under switching impulse voltages
Authors: HUANG 黄 Biao 标 , ZHOU 周 Xuan 旋 , WANG 王 She 涉 , ZHUANG 庄 Chijie 池杰 , ZENG 曾 Rong 嵘 , DENG 邓 Le 乐
Published: June 2024

The leader propagation is one of the most important stages in long air gap discharge. The mechanism behind leader re-illumination remains unclear. In high humidity conditions (20.0–30.1 g/m³), we have conducted experiments of long sparks in a 10 m ultra-high voltage (UHV) transmission line gap under switching impulse voltages. The positive leaders predominantly propagate discontinuously, with almost no significantly continuous propagation occurring. The leader channels are intensely luminous and each elongation segment is straight, with streamers resembling the “branch type” which differs from the “diffuse type” streamers at the front of continuous propagation leaders. The distribution of the propagation velocities is highly random (3.7–18.4 cm/μs), and the average velocity (9.2 cm/μs) significantly exceeds that of continuous propagation (1.5–2.0 cm/μs). Analysis suggests that the current-velocity models suitable for continuous leader propagation do not align well with the experimental data in re-illumination mode. Based on the discharge current waveforms and optical images, it is speculated that the newly elongated leader in re-illumination mode does not evolve gradually from the stem (about 1 cm) but rather evolves overall from a thermal channel much longer than stem.
An Incongruous Pair
Authors: Ward Matthew
Published: June 2024

Romantic writers and critics alike have long professed theories of a certain kind of privileged imagination that is tied to the sympathetic capacity of poets—one that has the power to see into all of life’s infinite variety and to yoke together apparently irreconcilable phenomena. In this chapter, we discover that such ideas, which have come to define a certain form of Romanticism, overlap with theories of the laughable professed at the time. Explanations for laughter and the creative faculties might seem an incongruous pair, but they have a lot in common in the Romantic period. To talk, as many did, of the sort of sympathy that ‘unites the most opposite extremes’, and works through ‘the remoteness of … combinations’, just as naturally implies an instinct for the comic as it does a sublime or visionary genius. Indeed, as we will see, in some cases the comical predates it.
Diagnostic accuracy of upper tract urothelial carcinoma using biopsy, urinary cytology, and nephroureterectomy specimens: A tertiary cancer center experience
Authors: Zhao Jianping , Shen Yuan , Guo Ming , Matin Surena F , Hansel Donna E , Guo Charles C
Published: June 2024

Objectives

We studied the diagnostic accuracy and discordance of upper tract urothelial carcinoma (UTUC) by comparing biopsy and urinary cytology with matched nephroureterectomy specimens.

Methods

Sixty-nine patients with UTUC without neoadjuvant treatment were retrospectively identified who had matched biopsy and nephroureterectomy specimens. Twenty patients had concurrent upper tract cytology. H&E and cytology slides were re-reviewed. Statistical analysis was performed.

Results

Patients included 48 men and 21 women with a mean age of 69 years. A concordant grade between biopsy and surgical specimen was present in 49 (71%) patients. The mean size of biopsy specimens in the discordant group was significantly smaller than that in the concordant group. Invasion was evaluated in 48 biopsy cases that had adequate subepithelial tissue, and 33 of them were diagnosed with concordant invasion status. Mean tumor size in both tumor grade and invasion discordant groups was significantly larger than that in the concordant group. High-grade urothelial carcinoma was detected in 84% of cases using urinary cytology.

Conclusions

Our study demonstrates the diagnostic challenges of UTUC on small biopsy specimens. Biopsy specimen size and tumor size are significantly associated with the diagnostic discordance. Upper tract cytology showed high diagnostic accuracy and should be complementary to the biopsy.
Multi-omic analysis tools for microbial metabolites prediction
Authors: Wu Shengbo , Zhou Haonan , Chen Danlei , Lu Yutong , Li Yanni , Qiao Jianjun
Published: June 2024

How to resolve the metabolic dark matter of microorganisms has long been a challenging problem in discovering active molecules. Diverse omics tools have been developed to guide the discovery and characterization of various microbial metabolites, which make it gradually possible to predict the overall metabolites for individual strains. The combinations of multi-omic analysis tools effectively compensates for the shortcomings of current studies that focus only on single omics or a broad class of metabolites. In this review, we systematically update, categorize and sort out different analysis tools for microbial metabolites prediction in the last five years to appeal for the multi-omic combination on the understanding of the metabolic nature of microbes. First, we provide the general survey on different updated prediction databases, webservers, or software that based on genomics, transcriptomics, proteomics, and metabolomics, respectively. Then, we discuss the essentiality on the integration of multi-omics data to predict metabolites of different microbial strains and communities, as well as stressing the combination of other techniques, such as systems biology methods and data-driven algorithms. Finally, we identify key challenges and trends in developing multi-omic analysis tools for more comprehensive prediction on diverse microbial metabolites that contribute to human health and disease treatment.
Efficient testing of the biomarker positive and negative subgroups in a biomarker-stratified trial
Authors: Li Lang , Ivanova Anastasia
Published: June 2024

In many randomized placebo-controlled trials with a biomarker defined subgroup, it is believed that this subgroup has the same or higher treatment effect compared with its complement. These subgroups are often referred to as the biomarker positive and negative subgroups. Most biomarker-stratified pivotal trials are aimed at demonstrating a significant treatment effect either in the biomarker positive subgroup or in the overall population. A major shortcoming of this approach is that the treatment can be declared effective in the overall population even though it has no effect in the biomarker negative subgroup. We use the isotonic assumption about the treatment effects in the two subgroups to construct an efficient way to test for a treatment effect in both the biomarker positive and negative subgroups. A substantial reduction in the required sample size for such a trial compared with existing methods makes evaluating the treatment effect in both the biomarker positive and negative subgroups feasible in pivotal trials especially when the prevalence of the biomarker positive subgroup is less than 0.5.
The Complex Role of Child Protection Officers in Arab Society in Israel: Focus on Power, State Connections and Absence of Indigenous Knowledge
Authors: Allassad Alhuzail Nuzha , Jedwab Merav
Published: June 2024

The Arab population in Israel is an ethnic, national, Indigenous minority experiencing discrimination and inequality, especially in education, health and welfare. This population’s constant societal change is coupled with social problems such as violence, crime, unemployment and poverty. These characteristics pose many challenges to social workers, particularly those empowered by the Youth Law (Care and Supervision), 1960, known as child protection officers (CPOs). Besides the usual challenges CPOs face, additional challenges stem from the Arab population’s being a traditional, collective society with a mistaken view of the CPO’s role and also from the state’s discriminatory policy. This exploratory qualitative study, using semi-structured interviews, of thirty Arab CPOs in Israel revealed challenges related to the role and to CPOs’ representation in the Arab population, namely, as having power backed by the law and being closely linked to the national establishment and institutions. Additional challenges include the lack of community-based treatment facilities, the absence of Indigenous knowledge in training and treatment and the lack of a mechanism to protect Arab CPOs from burnout and dropout. The findings are relevant to societies with minority populations.
Polymerase Chain Reaction on Respiratory Tract Specimens of Immunocompromised Patients to Diagnose Pneumocystis Pneumonia: A Systematic Review and Meta-analysis
Authors: Brown Lottie , Rautemaa-Richardson Riina , Mengoli Carlo , Alanio Alexandre , Barnes Rosemary A , Bretagne Stéphane , Chen Sharon C A , Cordonnier Catherine , Donnelly J Peter , Heinz Werner J , Jones Brian , Klingspor Lena , Loeffler Juergen , Rogers Thomas R , Rowbotham Eleanor , White P Lewis , Cruciani Mario
Published: June 2024

Background

This meta-analysis examines the comparative diagnostic performance of polymerase chain reaction (PCR) for the diagnosis of Pneumocystis pneumonia (PCP) on different respiratory tract samples, in both human immunodeficiency virus (HIV) and non-HIV populations.

Methods

A total of 55 articles met inclusion criteria, including 11 434 PCR assays on respiratory specimens from 7835 patients at risk of PCP. QUADAS-2 tool indicated low risk of bias across all studies. Using a bivariate and random-effects meta-regression analysis, the diagnostic performance of PCR against the European Organisation for Research and Treatment of Cancer–Mycoses Study Group definition of proven PCP was examined.

Results

Quantitative PCR (qPCR) on bronchoalveolar lavage fluid provided the highest pooled sensitivity of 98.7% (95% confidence interval [CI], 96.8%–99.5%), adequate specificity of 89.3% (95% CI, 84.4%–92.7%), negative likelihood ratio (LR−) of 0.014, and positive likelihood ratio (LR+) of 9.19. qPCR on induced sputum provided similarly high sensitivity of 99.0% (95% CI, 94.4%–99.3%) but a reduced specificity of 81.5% (95% CI, 72.1%–88.3%), LR− of 0.024, and LR+ of 5.30. qPCR on upper respiratory tract samples provided lower sensitivity of 89.2% (95% CI, 71.0%–96.5%), high specificity of 90.5% (95% CI, 80.9%–95.5%), LR− of 0.120, and LR+ of 9.34. There was no significant difference in sensitivity and specificity of PCR according to HIV status of patients.

Conclusions

On deeper respiratory tract specimens, PCR negativity can be used to confidently exclude PCP, but PCR positivity will likely require clinical interpretation to distinguish between colonization and active infection, partially dependent on the strength of the PCR signal (indicative of fungal burden), the specimen type, and patient population tested.
Loss of Cavin-2 destabilizes phosphatase and tensin homologue and enhances Akt signalling pathway in cardiomyocytes
Authors: Maruyama Naoki , Ogata Takehiro , Kasahara Takeru , Hamaoka Tetsuro , Higuchi Yusuke , Tsuji Yumika , Tomita Shinya , Sakamoto Akira , Nakanishi Naohiko , Matoba Satoaki
Published: June 2024

Aims

Specific cavins and caveolins, known as caveola-related proteins, have been implicated in cardiac hypertrophy and myocardial injury. Cavin-2 forms complexes with other caveola-related proteins, but the role of Cavin-2 in cardiomyocytes (CMs) is poorly understood. Here, we investigated an unknown function of Cavin-2 in CMs.

Methods and results

Under cardiac stress-free conditions, systemic Cavin-2 knockout (KO) induced mild and significant CM hypertrophy. Cavin-2 KO suppressed phosphatase and tensin homologue (PTEN) associated with Akt signalling, whereas there was no difference in Akt activity between the hearts of the wild-type and the Cavin-2 KO mice under cardiac stress-free conditions. However, after swim training, CM hypertrophy was more facilitated with enhanced phosphoinositide 3-kinase (PI3K)-Akt activity in the hearts of Cavin-2 KO mice. Cavin-2 knockdown neonatal rat CMs (NRCMs) using adenovirus expressing Cavin-2 short hairpin RNA were hypertrophied and resistant to hypoxia and H2O2-induced apoptosis. Cavin-2 knockdown increased Akt phosphorylation in NRCMs, and an Akt inhibitor inhibited Cavin-2 knockdown-induced anti-apoptotic responses in a dose-dependent manner. Cavin-2 knockdown increased phosphatidylinositol-3,4,5-triphosphate production and attenuated PTEN at the membrane fraction of NRCMs. Immunostaining and immunoprecipitation showed that Cavin-2 was associated with PTEN at the plasma membrane of NRCMs. A protein stability assay showed that Cavin-2 knockdown promoted PTEN destabilization in NRCMs. In an Angiotensin II (2-week continuous infusion)-induced pathological cardiac hypertrophy model, CM hypertrophy and CM apoptosis were suppressed in CM-specific Cavin-2 conditional KO (Cavin-2 cKO) mice. Because Cavin-2 cKO mouse hearts showed increased Akt activity but not decreased extracellular signal-regulated kinase activity, suppression of pathological hypertrophy by Cavin-2 loss may be due to increased survival of healthy CMs.

Conclusion

Cavin-2 plays a negative regulator in the PI3K-Akt signalling in CMs through interaction with PTEN. Loss of Cavin-2 enhances Akt activity by promoting PTEN destabilization, which promotes physiological CM hypertrophy and may enhance Akt-mediated cardioprotective effects against pathological CM hypertrophy.
The Secret Intelligence Service, Passport Control and Jewish Refugees from the Third Reich, 1938–1939
Authors: Baxter Christopher
Published: June 2024

The role of members of the British Secret Intelligence Service (SIS) in helping Jewish refugees flee Nazi persecution in the 1930s has garnered wide interest. It has been claimed that SIS officers, in their cover role as Passport Control Officers (PCOs), helped ‘save’ thousands of Jews from the Third Reich by issuing immigration visas. The focus, however, has been on individual SIS officers, rather than the collective effort of the many passport control staff involved in issuing visas. There has also been a tendency to devolve the matter into a process of producing crude balance sheets of numbers of Jews ‘saved’. This article seeks to understand how SIS came to exploit passport control work as cover for its activities and to assess the impact of the refugee crisis on SIS operations. It also aims to make sense of some of the statistics regarding visas issued by individuals such as Captain Frank Foley and Captain Thomas Kendrick, identifying some wild over-estimates. The article suggests that the humanitarian work carried out by SIS/PCO personnel should not be rendered as a competition as to who ‘saved’ the most refugees. It is important to research the subject forensically without a partisan attitude towards the personalities involved in order to uncover the truth and understand what happened.
Cognitive Impairment and Social Determinants of Health Among Indigenous Women
Authors: Roh Soonhee , Lee Yeon-Shim , Moon Heehyul , Steele Joel S , Warne Donald K , Lee Jung-Ah
Published: June 2024

Background and Objectives

Cognitive impairment and Alzheimer’s disease and related dementias (ADRD) pose significant challenges for Indigenous populations, necessitating urgent research. Limited evidence suggests that high rates of ADRD among Indigenous peoples are associated with social determinants of health (SDOH), such as education, income, health literacy, religion, and social engagement.

Research Design and Methods

Collaborating with a Northern Plains tribe, participants were recruited 123 self-identified Indigenous women aged 40–70 through a comprehensive recruitment strategy. Employing the SDOH framework, the research assessed cognitive impairment and Alzheimer’s disease knowledge (ADK), utilizing the Ascertain Dementia 8 and Alzheimer’s disease knowledge scales (ADK-30). The investigation examined the relationships between selected SDOH variables and cognitive impairment status.

Results

More than half of the participants showed signs of cognitive impairment, which correlated with lower income and education levels. Increased knowledge about Alzheimer’s disease, particularly in terms of treatment management and its life impact subscales, was associated with lower odds of cognitive impairment. Conversely, higher levels of depressive symptoms and participation in religious activities were linked to increased odds of cognitive impairment.

Discussion and Implications

The findings underscore the importance of culturally grounded tools and SDOH frameworks tailored to Indigenous contexts in addressing ADRD disparities. Future research should integrate historical and cultural factors to advance health equity within Indigenous communities, ultimately mitigating the impact of ADRD and promoting overall well-being.
Market landscape and insurer–provider integration: the case of ambulatory surgery centers
Authors: Zhao Xiaoxi , Richards Michael R , Damberg Cheryl L , Whaley Christopher M
Published: June 2024

Insurer–provider integration is a new form of vertical integration, with increasing prominence in health care markets. While there are potential benefits from tighter alignment between providers and payers, risks of perverse impacts on health care markets loom large. Yet, little is known about this new wave of consolidation, which limits options for policy or regulatory responses. We focus on a dominant insurer's acquisitions of ambulatory surgery centers (ASCs) to document the growth and geographic spread of these ownership events. We found that a diverse swathe of the United States has experienced an insurer-led ASC takeover. The acquisitions are also more frequently in areas where the insurer holds a higher enrollee market share at baseline, although a linear prediction of the likelihood of ASC acquisition shows a more nuanced picture.
Introgression of the Gamete Recognition Molecule, Bindin, in the Sea Urchin Diadema
Authors: Lessios H A
Published: June 2024

Synopsis

Hybridization is important in evolution, because it is a necessary (though not sufficient) step in the introgression of potentially adaptive variation between species. Bindin is a gamete recognition protein in echinoids and asteroids, capable of blocking cross-fertilization between species to varying degrees. Four species of the sea urchin genus Diadema are broadly sympatric in the Indo-Pacific: D. paucispinum, D. savignyi, D. clarki, and D. setosum. Data from three published studies, one of identification of hybrids through allozymes, one of the phylogeography of mitochondrial DNA, and one of the phylogeny of bindin, were combined to assess the degree of bindin introgression between these four species. I analyzed sequences of the ATPase 8 and ATPase 6 mitochondrial genes and of bindin, sampled throughout the species ranges, with an isolation–migration algorithm, IMa3. IMa3 uses a coalescent approach to produce Bayesian estimates of effective population sizes and gene flow between populations. The results showed that bindin alleles coalesce completely within the species bounds of D. clarki and of D. setosum. The sister species D. paucispinum and D. savignyi, however, were estimated as having exchanged a bindin allele at an average of every one to two-and-a-half generations since they speciated from each other. As the allozyme study detected nine hybrids between three of these species in Okinawa (most of them between D. setosum and D. savignyi) in a single sample, hybrids between these species are produced, but bindin does not introgress. Therefore, bindin must not be efficient in blocking heterospecific fertilizations. Complete, or almost complete, reproductive isolation between species of Diadema must result from low hybrid fitness.
Cumulus: a federated electronic health record-based learning system powered by Fast Healthcare Interoperability Resources and artificial intelligence
Authors: McMurry Andrew J , Gottlieb Daniel I , Miller Timothy A , Jones James R , Atreja Ashish , Crago Jennifer , Desai Pankaja M , Dixon Brian E , Garber Matthew , Ignatov Vladimir , Kirchner Lyndsey A , Payne Philip R O , Saldanha Anil J , Shankar Prabhu R V , Solad Yauheni V , Sprouse Elizabeth A , Terry Michael , Wilcox Adam B , Mandl Kenneth D
Published: June 2024

Objective

To address challenges in large-scale electronic health record (EHR) data exchange, we sought to develop, deploy, and test an open source, cloud-hosted app “listener” that accesses standardized data across the SMART/HL7 Bulk FHIR Access application programming interface (API).

Methods

We advance a model for scalable, federated, data sharing and learning. Cumulus software is designed to address key technology and policy desiderata including local utility, control, and administrative simplicity as well as privacy preservation during robust data sharing, and artificial intelligence (AI) for processing unstructured text.

Results

Cumulus relies on containerized, cloud-hosted software, installed within a healthcare organization’s security envelope. Cumulus accesses EHR data via the Bulk FHIR interface and streamlines automated processing and sharing. The modular design enables use of the latest AI and natural language processing tools and supports provider autonomy and administrative simplicity. In an initial test, Cumulus was deployed across 5 healthcare systems each partnered with public health. Cumulus output is patient counts which were aggregated into a table stratifying variables of interest to enable population health studies. All code is available open source. A policy stipulating that only aggregate data leave the institution greatly facilitated data sharing agreements.

Discussion and Conclusion

Cumulus addresses barriers to data sharing based on (1) federally required support for standard APIs, (2) increasing use of cloud computing, and (3) advances in AI. There is potential for scalability to support learning across myriad network configurations and use cases.
Milk microbiome in the first month of lactation and at weaning from ewes supplemented with zinc pre- and postpartum
Authors: Knuth Ryan M , Page Chad M , Stewart Whitney C , Hummel Gwendolynn L , Woodruff Kelly L , Whaley Jaelyn R , Springer Alexis L , Austin Kathleen J , Murphy Thomas W , Bisha Bledar , Cunningham-Hollinger Hannah C
Published: June 2024

Mastitis is an important disease with economic and welfare implications in both clinical and subclinical states. The aim of this research was to sequence the hypervariable V4 region of the 16S rRNA gene to describe the microbial diversity and taxonomy of milk from clinically healthy ewes (Rambouillet, WF = 9; Hampshire, BF = 5). Experimental ewes represented a subset of a larger study assessing the impacts of divergent dietary zinc (Zn) concentrations [1 × National Academics of Sciences, Engineering, and Medicine (NASEM) recommendations = CON or 3 × NASEM recommendations = ZnTRT] throughout late gestation and lactation. Milk was collected at four periods during early lactation (18 to 24 h, 7 d, 14 d, and 21 d postpartum) and at weaning (84 ± 14 d postpartum). Somatic cell counts (SCC) were quantified, averaged, and classed (low: < 500 × 103; medium: 500 × 103 – 100 × 104; high: > 100 × 104 cells/mL). Milk samples (n = 67) were sequenced to identify bacteria and archaea; the most abundant phyla were Actinobacteria, Bacteroidetes, Cyanobacteria, Euryarchaeota, Firmicutes, Fusobacteria, Lentisphaerae, Proteobacteria, Spirochaetes, Tenericutes, Saccharibacteria TM7, and Verrucomicrobia. Mastitis pathogens were among the most relatively abundant genera, including Staphylococcus, Mannheimia, Corynebacterium, and Pseudomonas. Effects of breed, dietary Zn concentration, SCC class, and their two-way interactions on milk microbiome diversity and taxonomy were assessed within early lactation (using a repeated measures model) and weaning samples. Alpha-diversity metrics included Pielou’s evenness, Faith’s phylogenetic diversity, and Shannon’s entropy indices. The main and interactive effects between Zn treatment, breed, SCC class, and period were variable in early lactation and not evident in weaning samples. Milk from BF ewes had increased Faith’s phylogenetic diversity and Shannon’s entropy, and differed in unweighted UniFrac composition (P ≤ 0.10). Milk from CON ewes had a reduced rate of composition change through early lactation (P = 0.02) indicating greater microbiome stability than ZnTRT ewe milk. These results support that milk is not sterile, and breed, dietary Zn concentration, and SCC class variably affect the milk microbiome. Findings from the current study provide important foundational insights into the effects of increased dietary Zn supplementation on longitudinal changes in the milk microbiome and associations with mammary gland health and mastitis.