bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-efficiency transformation and gene expression inPicosynechococcussp. PCC 7002
Authors: Hren Andrew P. , Abraham Joshua P. , Tumen-Velasquez Melissa P. , Vergara Michael Melesse , Guss Adam M. , Alexander William G. , Pfleger Brian F. , Fox Jerome M. , Eckert Carrie A. 
Published: September 2024

AbstractCyanobacteria are promising microbial platforms for a myriad of biotechnological applications, from sustainable biomaterials to photosynthetic chemical production, but still lack the breadth of genetic tools available for more commonly engineered microbes such asEscherichia coli. This study develops genetic tools to enhance the transformation efficiency and heterologous gene expression inPicosynechococcussp. PCC 7002, a fast-growing, halotolerant, and naturally competent strain. Integration of fluorescent reporter cassettes across the genome revealed an integration site that yields a fourfold improvement in gene expression relative to previously reported sites. Protocol optimization and engineered DNA methylation inE. coliincreased transformation efficiency by over tenfold. This work provides an experimental framework for efficient genome editing and metabolic engineering in the model cyanobacterium PCC 7002.
Cortical state contributions to response variability in the early visual cortex: A system identification approach
Authors: Sooriyaarachchi Jinani , Zhan Chang’an , Baker Curtis L. 
Published: September 2024

AbstractNeurons in the early visual cortex respond selectively to multiple features of visual stimuli, but they respond differently to repeated presentation of the same visual stimulus. Such trial-to-trial response variabilities are often treated as noise and addressed by simple trial-averaging to obtain the stimulus-driven response, though this approach is insufficient to fully remove the response variability. More importantly, there is evidence that response variability may primarily be caused by non-sensory factors, particularly by variations in cortical state.Here we recorded and analyzed neuronal spiking activity in response to natural images from areas 17 and 18 of cats, along with local population neuronal signals; local field potential (LFP) and multi-unit activity (MUA). We used a variability ratio (VR) measure to quantify the variability of neural responses across trials and two cortical state indicative measures; global fluctuation index (GFI) calculated using MUA and synchrony index (SI) calculated using LFP signals. We propose a compact convolutional neural network model with two parallel pathways, to capture the stimulus- driven activity and the cortical state-driven response variabilities. The stimulus-driven pathway contains a spatiotemporal filter, a parametric rectifier and a Gaussian map and the cortical state-driven pathway contains temporal filters for MUA and LFP. The model parameters are fit to best predict each neuron’s spiking activity.Single neurons showed highly varying degrees of trial-to-trial response variability, even when recorded simultaneously. The fitted model performed with a significantly higher accuracy in predicting neural responses compared to a basic model with a stimulus-driven pathway alone. The neurons with higher response variability benefited more from the cortical state-driven pathway compared to less variable neurons. These results provide insights to understanding the possibility of trial-to-trial response variabilities emerging as an effect of cortical state dynamics.
The tilt illusion arises from an efficient reallocation of neural coding resources at the contextual boundary
Authors: Zhang Ling-Qi , Mao Jiang , Aguirre Geoffrey K. , Stocker Alan A. 
Published: September 2024

AbstractThe tilt illusion — a bias in the perceived orientation of a center stimulus induced by an oriented surround — illustrates how context shapes visual perception. While the tilt illusion has been the subject of quantitative study for over 85 years, we still lack a comprehensive account of the phenomenon that connects its neural and behavioral characteristics. Here, we demonstrate that the tilt illusion originates from a dynamic change in neural coding precision induced by the surround context. We simultaneously obtained psychophysical and fMRI responses from human subjects while they viewed gratings in the absence and presence of an oriented surround, and extracted sensory encoding precision from their behavioral and neural data. Both measures show that in the absence of a surround, encoding reflects the natural scene statistics of orientation. However, in the presence of an oriented surround, encoding precision is significantly increased for stimuli similar to the surround orientation. This local change in encoding is sufficient to accurately predict the behavioral characteristics of the tilt illusion using a Bayesian observer model. The effect of surround modulation increases along the ventral stream, and is localized to the portion of the visual cortex with receptive fields at the center-surround boundary. The pattern of change in coding accuracy reflects the surround-conditioned orientation statistics in natural scenes, but cannot be explained by local stimulus configuration. Our results suggest that the tilt illusion naturally emerges from a dynamic coding strategy that efficiently reallocates neural coding resources based on the current stimulus context.
Probing the position-dependent optical energy fluence rate in three-dimensional scattering samples
Authors: Akdemir Ozan , Truong Minh Duy , Rates Alfredo , Lagendijk Ad , Vos Willem L. 
Published: September 2024

The accurate determination of the position-dependent energy fluence rate of scattered light (which is proportional to the energy density) is crucial to the understanding of transport in anisotropically scattering and absorbing samples, such as biological tissue, seawater, atmospheric turbulent layers, and light-emitting diodes. While Monte Carlo simulations are precise, their long computation time is not desirable. Common analytical approximations to the radiative transfer equation (RTE) fail to predict light transport and could even give unphysical results. Therefore, we experimentally probe the position-dependent energy fluence rate of light inside scattering samples where the widely used P1 and P3 approximations to the RTE fail. The samples are three-dimensional (3D) aqueous suspensions of anisotropically scattering and both absorbing and nonabsorbing spherical scatterers, namely, microspheres (r=0.5µm) with and without absorbing dye. To probe the energy fluence rate, we detect the emission of quantum-dot reporter particles that are excited by the incident light and that are contained in a thin capillary. By scanning the capillary through the sample, we access the position dependence. We present a comprehensive discussion of experimental limitations and of both random and systematic errors. Our observations agree well with the Monte Carlo simulations and the P3 approximation of the RTE with a correction for forward scattering. In contrast, the P1 and the P3 approximations deviate increasingly from our observations, ultimately even predicting unphysical negative energies.

Published by the American Physical Society
2024
ρ
meson magnetic dipole moment from
BaBar

e+e−→π+π−π0π0
cross section measurement
Authors: Rojas Antonio , Toledo Genaro 
Published: September 2024

We obtain the value of the magnetic dipole moment of the ρ meson, using data from the collaboration for the e+e−→π+π−2π0 process. The considered center of mass energy range is from 0.9 to 1.8 GeV. We describe the γ*→4π vertex using a vector meson dominance model, including the intermediate resonant contributions relevant at these energies. We find μρ=2.7±0.3 in e/2mρ units. We improve on the previous extracted value, where preliminary data from the same collaboration was used, by considering definite data, better grounded values of the parameters involved, and an explicit gauge invariant description of the process.

Published by the American Physical Society
2024
Theoretical study of the
π+p→pa0+ϕ
reaction
Authors: Xu Aojia , Li Ruitian , Luo Xuan , Sun Hao 
Published: September 2024

We study the production of hyperon resonances in the π+p→pa0+ϕ reaction within an effective Lagrangian approach. The model includes the production of Δ(1940) and Δ(1920) in the intermediate state excited by the ρ and p exchanges between the initial proton and π meson. Because of the large contribution of ρ exchange in Δ(1940) production, Δ(1940) is found to be a significant contribution near the threshold in this reaction. We provide total and differential cross section predictions for the reaction and discuss the possible influence of model parameters, off-shell effects, and branching ratios for Δ(1940)→pa0 and Δ(1920)→pa0 decays, which will be useful in future experimental studies. This reaction can provide a platform for studying the features of Δ(1940) resonance, especially the coupling to the pa0 channel.

Published by the American Physical Society
2024
Strong dipole-dipole interactions via enhanced light-matter coupling in composite nanofiber waveguides
Authors: Jain Kritika , Ruks Lewis , le Kien Fam , Busch Thomas 
Published: September 2024

We study the interaction of emitters with a composite waveguide formed from two parallel optical nanofibers in regimes of experimental importance for atomic gases or solid-state emitters. Using the exact dyadic Green's function we comprehensively investigate the coupling efficiency and the fiber-induced Lamb shift accounting for variations in emitter positions and fiber configurations. This reveals coupling efficiencies and Purcell factors that are enhanced considerably beyond those using a single fiber waveguide, and robustness in the figures of merit. We finally investigate resonant dipole-dipole interactions and the generation of entanglement between two emitters mediated through the composite waveguide under excitation. We show that the concurrence can be enhanced for two fiber systems, such that entanglement may be present even in cases where it is zero for a single fiber. All-fiber systems are simple in construction and benefit from a wealth of existing telecommunications technologies, while enjoying strong couplings to emitters and offering interesting light-matter functionalities specific to slot waveguides.

Published by the American Physical Society
2024
Comparison of estimation limits for quantum two-parameter estimation
Authors: Yung Simon K. , Conlon Lorcán O. , Zhao Jie , Lam Ping Koy , Assad Syed M. 
Published: September 2024

Measurement estimation bounds for local quantum multiparameter estimation, which provide lower bounds on possible measurement uncertainties, have so far been formulated in two ways: by extending the classical Cramér-Rao bound (e.g., the quantum Cramér-Rao bound and the Nagaoka Cramér-Rao bound) and by incorporating the parameter estimation framework with the uncertainty principle, as in the Lu-Wang uncertainty relation. In this work, we present a general framework that allows a direct comparison between these different types of estimation limits. Specifically, we compare the attainability of the Nagaoka Cramér-Rao bound and the Lu-Wang uncertainty relation, using analytical and numerical techniques. We show that these two limits can provide different information about the physically attainable precision. We present an example where both limits provide the same attainable precision and an example where the Lu-Wang uncertainty relation is not attainable even for pure states. We further demonstrate that the unattainability in the latter case arises because the figure of merit underpinning the Lu-Wang uncertainty relation (the difference between the quantum and classical Fisher information matrices) does not necessarily agree with the conventionally used figure of merit (mean-squared error). The results offer insights into the general attainability and applicability of the Lu-Wang uncertainty relation. Furthermore, our proposed framework for comparing bounds of different types may prove useful in other settings.

Published by the American Physical Society
2024
Operando
X-ray and Mass Spectroscopy of Reduced Graphene Oxide (
rGO
)-Mediated Cobalt Catalysts for Boosting the Hydrogen Evolution Reaction
Authors: Mariano Carl Osby M. , Clemente Russell Hizon , Tsai Meng-Hsuan , Chin Yi-Ying , Chen Jin-Ming , Lee Jyh-Fu , Lu Ying-Jui , Chen Chien-Ming , Chen Po-Tuan , Chuang Cheng-Hao 
Published: September 2024

Inserting underlying reduced graphene oxide (rGO) into Co aims to regulate the chemical integrity and catalytic ability of the Co upper layer for hydrogen evolution reaction (HER) as a green-hydrogen goal. Principally, an mass spectrometer indicates 3.8 times more considerable hydrogen generation in Co/rGO than in Co. The spectroscopical approaches, combining soft and hard X-ray probing, illustrate the chemical oxidation evolution of electronic Co-3 and Co-4 states differently regarding the underlying rGO contribution. A unique examination is regarded as the phase transition from the initial middle to high oxidation and to deoxidation, related to the intermediate Co0 existence and H2 generation. The chemical adsorption of Co–O(H), Co–Hads, and H2 molecules desorption have been assigned their spectral significances. The rGO mediation indicates two significant metal Co and Co–O(H) blocks in the two-dimensional - domain. Density-functional-theory (DFT) calculation provides the regeneration, sustained stability, and decreasing energy barrier of Co–Hads catalysts due to the rGO incorporation, thereby augmenting the HER enhancement through the alternative Volmer-Heyrovsky process. The experiment, including mass spectrometer, soft, and hard X-ray, provides evidence regarding the catalyst’s HER enhancement. This study offers insights into the chemical composition, electronic structure, and active role of Co bonded with or without the extinct OH and H bonds, advancing our comprehension of electrocatalytic reactions, thus taking our knowledge of composite materials to stepwise electrocatalytic reactions forward. This cutting-edge experiment under environment and DFT studies gives critical information regarding the catalytic mechanism and chemical stability of the Co and rGO materials.

Published by the American Physical Society
2024
Greening the procurement: a SMART evaluation of environmental sustainability in Australian government purchasing policies
Authors: Shahin Aryana , Polonsky Michael , Wood Lincoln C. , Presbitero Alfred , Wijayasundara Mayuri 
Published: September 2024

PurposeThis study evaluates how well Victorian local councils’ procurement policies align with the sustainable and circular economy (CE) approach that prioritises sustainable and regenerative practices. It proposes a set of criteria designed to effectively integrate environmental sustainability issues into purchasing policies.Design/methodology/approachEmploying the Specific, Measurable, Assignable, Realistic and Time-bound (SMART) framework, a multi-dimensional content analysis guided by the goal-setting theory was applied to evaluate all 79 Victorian local councils’ procurement policies. This approach provided an assessment of policy specificity, measurability, assignability, realism and time sensitivity in promoting environmental sustainability through purchasing policies.FindingsThe findings underscored a significant deficiency in policy adherence to all SMART criteria concerning environmental sustainability, hindering the effective green purchasing decisions within government entities. This lack of integration of greening in purchasing policy poses challenges for manufacturers of waste-derived goods, obscuring the procurement objectives of these critical public sector customers.Practical implicationsThe paper contributes to the sustainable procurement (SP) discourse by proposing guidelines aimed at improving the efficacy of governmental purchasing of sustainable products. These guidelines address the broader imperative to mitigate the environmental impacts of governmental spending on less sustainable goods, thereby fostering ecological sustainability and promoting responsible consumption.Originality/valueWhile past studies have often relied on subjective content analysis methods, the SMART assessment used to develop the environmental sustainability criteria for purchasing policies, which distinguishes this study from previous governmental policy evaluation studies. This approach marks a departure from traditional governmental policy evaluation studies, offering a more structured analysis of policy effectiveness in promoting SP practices.
Entrepreneurial orientation and supply chain performance: the roles of entrepreneurial competence and local community networking (evidence from Ghana)
Authors: Agbemude Samuel , Nuertey Dorcas , Poku Emmanuel , Owusu Felix 
Published: September 2024

PurposeThis study aims to assess the effect of entrepreneurial orientation on supply chain performance both directly and indirectly through entrepreneurial competence, as well as the moderating role of local community networking in these relationships, within the context of institutional voids in Ghana.Design/methodology/approachThe study utilized a cross-sectional survey data from 225 small and medium sized enterprises (SMEs) in order to test the hypotheses. The data analysis was conducted using partial least squares structural equation modelling techniques.FindingsThe results revealed that entrepreneurial orientation is a significant positive predictor of both entrepreneurial competence and supply chain performance. Similarly, entrepreneurial competence was shown to positively predict supply chain performance, both directly and as a mediator between entrepreneurial orientation and supply chain performance. Local community networking, however, positively moderated the relationship between entrepreneurial orientation and entrepreneurial competence but not the relationship between entrepreneurial orientation and supply chain performance.Originality/valueThis study contributes to literature by looking at the relationship between entrepreneurial orientation, entrepreneurial competence, local community networking and supply chain performance within the context of an emerging economy with institutional voids. The study shows the importance of an entrepreneurial mindset in developing the necessary skills, competences and abilities needed to survive in the turbulent business environment.
Affective states and a firm’s performance: the mediating role of dynamic managerial capabilities
Authors: Bogodistov Yevgen , Schmidt Susanne 
Published: September 2024

PurposeExtant research supports the importance of dynamic managerial capabilities in capturing managers’ individual roles in organisations’ adjustments to change. This paper develops a multidimensional scale for measuring dynamic managerial capabilities consisting of sensing, seizing and reconfiguration capacities that mediate between managers’ affective states and their firms’ performance.Design/methodology/approachThe scale is validated in a survey-based study among 204 managers in companies in the United States of America (USA). We applied a multiple regression model (a triple mediation) using each of DMCs’ three dimensions to test the effects of managers’ affective states on their firms’ performance.FindingsThe multidimensional construct of DMCs adds about 15 % of variance explained to a firm’s performance, as perceived by its managers. So managers’ affective states do have an impact on DMCs and, later, on their firms’ performance.Research limitations/implicationsWe show the impact of negative and positive affect on DMCs. We also show that DMCs’ three dimensions should be treated in a formative manner that advances discussion on DMCs and their role in a firm’s performance.Practical implicationsUnderstanding managers’ affective states helps incorporate “hot cognition” into firms’ strategising processes. Although both positive and negative emotions can be helpful, depending on the situation, positive affect is generally more valuable than negative affect as it relates to a firm’s performance.Originality/valueOur work proposes measuring DMCs based on Teece’s (2007) disaggregation of DMCs into sensing, seizing and reconfiguration capacities. We approach each of these dimensions separately and show that managers’ affective states influence each dimension differently.
Punishment and survival – incarcerated persons' experiences with extreme heat in Texas prisons
Authors: Purdum Carlee , Dixon Benika , Dominick Amite 
Published: September 2024

PurposeThe impact of extreme heat on prisons and carceral facilities is becoming increasingly visible, yet remains overlooked by scholars, practitioners and policymakers. Prisons are a unique type of infrastructure designed to severely limit and control the movement of hundreds and even thousands of individuals as a form of punishment. This leads to many significant challenges to mitigating the risk of heat-related illness in prisons and other carceral spaces that have remained overlooked across many disciplines including emergency management, disasters, corrections and public health.Design/methodology/approachFor this study, we analyzed 192 surveys from incarcerated persons in state prisons throughout Texas to understand how incarceration and the punitive prison environment create challenges to managing extreme heat in prisons.FindingsWe found that characteristics of modern incarceration, including communal distribution of resources, crowded conditions and a lack of agency for incarcerated people, create barriers to accessing resources during periods of extreme heat. Furthermore, the punitive nature of the prison environment as manifested in the relationship between staff and incarcerated persons and certain prison policies also create barriers to incarcerated persons accessing resources to reduce their risk of heat-related illness and death.Social implicationsThese issues are particularly relevant to the health and safety of incarcerated persons during periods of extreme temperatures but also speak broadly to the implications of incarceration, disaster risk, and the advancement of human rights for incarcerated people.Originality/valueThis article addresses a gap in the literature by including the perspectives of persons incarcerated in Texas prisons experiencing extreme heat and implicates the characteristics of incarceration and punishment in the production of disaster risk.