bluuebunny/crossref_metadata_2025 huggingface dataset:
DAMPING BEHAVIOR OF DRY AND EPOXY- IMPREGNATED CARBON NANOTUBE YARN
Authors: DYER W. HENRY , BAKIS CHARLES E.
Published: October 2022

Multiwalled carbon nanotubes (CNTs) are believed to add beneficial damping to fiber reinforced polymer composites on account of their weak, reversible inter-wall bonding and CNT/polymer bonding. An effective way to add a large volume fraction of CNTs to a fiber composite is to form the CNTs into condensed yarns and add the yarns to the interlayer regions of composites with the CNTs oriented along the primary loading direction. To address the ongoing need for additional data on the damping provided to fiber composites by CNT yarns, the current investigation focuses on the tensile damping behavior of a commercially available yarn with and without epoxy impregnation. Based on quasi-static tensile tests using cross-sectional areas measured by ethanol immersion testing, dry yarn was observed to have an elastic modulus of 109 GPa and an ultimate tensile strength of 1.30 GPa, while impregnated yarn had a modulus of 62 GPa and a strength of 0.813 GPa. Dry and impregnated yarns exhibited a ratcheting mechanism, where permanent strain is accumulated with repeated load cycling. Through dynamic mechanical analysis, it was shown that both dry and impregnated yarns exhibited high damping, with average initial loss factors of 0.110 and 0.0953, respectively. With continued cycling and increased strain, the storage modulus of impregnated yarns increased by 450%, while the loss modulus increased by 256% and the loss factor decreased by 35%. Dry and impregnated yarns exhibited quasi-static and dynamic properties that were highly sensitive to loading history, although impregnated yarns showed greater degrees of change over larger numbers of loading cycles. It is shown that an established micromechanical model can predict to within 6% the loss factor of a [90]6 hybrid carbon/epoxy laminate containing 10 vol% CNT yarns aligned in the 0° orientation, based on known dynamic properties of the impregnated yarn and the baseline laminate without CNTs.
Salud en ruinas: la destrucción capitalista del cuidado médico en el Instituto Materno Infantil de Bogotá
Authors: Abadía Barrero César Ernesto
Published: October 2022

Salud en ruinas relata varias décadas de la historia de El Materno, el hospital universitario y centro de atención en salud maternal y neonatal más antiguo de Colombia, mientras enfrentaba amenazas constantes de cierre por parte del gobierno. En esta etnografía colaborativa y basada en equipos, salen a flote las dinámicas cotidianas en torno a la enseñanza, el aprendizaje y el trabajo en salud antes, durante y después de la privatización del hospital. Junto con narraciones detalladas de las y los protagonistas de la historia del Materno, el autor analiza la vida social de las políticas neoliberales en salud y argumenta que la privatización de la atención médica no se trata solo de desfinanciar los hospitales públicos; también arruina ricas tradiciones de cuidado médico al negar o destruir prácticas en salud que desafían a la medicina occidental. A pesar de los recortes radicales en la financiación y un sistema privatizado, corrupto y disfuncional, los profesores, el personal y los estudiantes de El Materno continuaron encontrando formas creativas de brindar atención médica innovadora, de alta calidad y no mercantilizada. Al rastrear las violencias, los conflictos, las esperanzas y las incertidumbres que caracterizaron las luchas por mantener abierto El Materno, Abadía-Barrero demuestra que cualquier estudio del cuidado médico debe estar imbuido en historias políticas más amplias.
Do Political Differences Inhibit Market Transactions? An Investigation in the Context of Online Lending
Authors: Wang Hongchang , Overby Eric
Published: October 2022

Do political differences, which are becoming increasingly acute among Americans, inhibit market transactions? We study this by examining whether the perceived political distance between investors and borrowers in an online lending market affects whom investors choose to fund. Using two complementary empirical approaches (a gravity model and a difference-in-differences analysis), we find a nuanced effect: Investors from comparatively conservative states consider political distance when making lending decisions, whereas investors from comparatively liberal states do not. Lending activity drops by as much as 11.6% when the investor’s state is more conservative than the borrower’s state. We also find that political distance between investors and borrowers reduces the likelihood that a borrower’s listing will be funded, thereby limiting the ability of the market to fulfill its function. However, political distance does not predict loan performance, which is consistent with another finding: The relationship of political distance to lending activity is not significant for experienced investors. It may be that investors stop considering political distance after they learn from experience that it does not predict loan performance. We find evidence for two mechanisms underlying our results: (1) a preference-based mechanism, in which investors from conservative states have a general preference for borrowers from conservative states, and (2) a rationality-based mechanism in which investors from conservative states use political ideology as a signal of creditworthiness (rightly or wrongly). Our results contribute to the literatures on online frictions and political (in)tolerance and have implications for the design of online lending (and other) markets.

This paper was accepted by Kartik Hosanagar, information systems.

Supplemental Material: The data files and online appendix are available at https://doi.org/10.1287/mnsc.2022.4575 .
Convergence of a Packet Routing Model to Flows over Time
Authors: Sering Leon , Vargas Koch Laura , Ziemke Theresa
Published: October 2022

Mathematical approaches for modeling dynamic traffic can be roughly divided into two categories: discrete packet routing models and continuous flow over time models. Despite very vital research activities on models in both categories, their connection was poorly understood so far. We build this connection by specifying a (competitive) packet routing model, which is discrete in terms of flow and time, and proving its convergence to the intensively studied model of flows over time with deterministic queuing. More precisely, we prove that the limit of the convergence process when decreasing the packet size and time step length in the packet routing model constitutes a flow over time with multiple commodities. In addition, we show that the convergence result implies the existence of approximate equilibria in the competitive version of the packet routing model. This is of significant interest as exact pure Nash equilibria cannot be guaranteed in the multicommodity setting.

Funding: This work was funded by the Deutsche Forschungsgemeinschaft (German Research Foundation) under Germany’s Excellence Strategy—The Berlin Mathematics Research Center MATH+ [Grant EXC-2046/1, project ID: 390685689] and the Research Training Group [Grant 2236 UnRAVeL].
Move-in Ready or Fixer-Upper? VC Specialization and Start-up Innovation
Authors: Alvarez-Garrido Elisa
Published: October 2022

Extant scholarship typically assumes that VC firms prefer to pick winners. I offer an alternative perspective: that specialist VC firms can select less attractive start-ups—with innovative potential but in need of help—and then contribute to the start-ups’ innovative processes so they can achieve their potential. The analogy is buying a fixer-upper house, which, with the right help, can be brought to the level of one that is move-in ready. I argue that specialist (versus generalist) VC firms in the syndicate have superior commercialization knowledge and specialized resource networks, and they can choose to follow a move-in-ready strategy (select winners) or a fixer-upper strategy (build winners). This choice is contingent on the research environment and how unique the help from the specialist VC firm is: in well-developed research environments, a specialist adds less value and may follow a move-in-ready strategy; in less-developed research environments, a specialist adds more value and may follow a fixer-upper strategy. I leverage an ideal empirical context, global biotechnology VC-backed start-ups, over the period 1996–2006, when the biotech industry was established in the United States and developing in 25 other countries, and highlight qualitative insights from 20 interviews with investors in seven countries.

Funding: Funding from the Mack Institute for Innovation Management at the Wharton School and from the CIBER at the University of South Carolina is greatly appreciated.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/stsc.2022.0176 .
Organisational health literacy: empowering gastrointestinal patients
Authors: Smith Graeme D , Poon Sara
Published: October 2022

Living with a chronic gastrointestinal disorder, such as inflammatory bowel disease, can be a challenging experience. Management often requires active involvement by patients through self-management activities to control disease processes and reduce the risk of complications. A range of skills are required to ensure successful self-management, including the ability to detect worsening symptoms and adhere to treatment regimens and lifestyle restrictions. Central to effective self-management is the ability to access and process reliable health-related information. However, the content and the way in which gastrointestinal information is delivered in the clinical setting may not always be entirely suitable for the target population. Such health information activities reflect an important aspect of health literacy, as well as the knowledge and skill that are required by a patient and their family to make informed healthcare decisions. It is a concept that is increasingly viewed as the interplay between personal and organisational health literacy (OHL) factors. Inadequate health literacy in people with chronic illness, including gastrointestinal conditions, is associated with poorer health outcomes and greater complications. Healthy People 2030 has elevated the status of health literacy, stressing that it has the potential to enhance quality of healthcare, including the provision of effective person-centred care. To date, limited consideration has been given to gastrointestinal-related health literacy issues, and more attention should be given to this social determinant of health. This piece explores some the most pertinent nursing issues related to health literacy in the gastrointestinal setting, with specific focus on the importance of establishing OHL.
Extending understanding of ‘care’ as an embodied phenomenon: Alexander Technique teacher perspectives on restoring carers to themselves
Authors: Woods Charlotte , Wolverson Emma , Glover Lesley
Published: October 2022

Data from an international survey of teachers of the Alexander Technique – an embodied form of self-care – illustrate their perspectives on how the Alexander Technique supports caring by combatting carer self-loss. Understanding of care as an embodied phenomenon is furthered by describing: (1) specific embodied habits that seem highly pertinent to care of self and others; and (2) how they might be (re)acquired in learning the Alexander Technique. In offering both practical and philosophical ways in which the Alexander Technique differs from alternatives, the article invites fresh thinking about theory and practice in supporting care, and argues that research on the Alexander Technique in the context of caring is warranted.
What if time was not money? Towards a pluriversal understanding of time for sustainable consumption
Authors: Stroude Aurianne
Published: October 2022

Facing the growing emergency of changing consumption patterns to address the environmental crisis, many scholars have been studying individual behavioural change. Acknowledging that consumption is not just an individual choice but a social practice – embedded in socioeconomic, material, affective and cultural configurations – recent work has broadened the understanding of how to address sustainable consumption. Even though sustainability issues are fundamentally time-bound, time is seldom conceptualised as a substantive element. This article aims to contribute to this debate by raising the importance of time understandings to address (un)sustainable consumption. In the first part of this article the idea that the dominant economic system has pervaded our imaginaries, our behaviours and interactions, including how we see and experience time, is discussed, drawing mainly on degrowth scholars. The main understandings of time that stem from the assumption that ‘time is money’ are highlighted through the metaphors of the clock, the arrow and the target. Drawing on a qualitative fieldwork carried out in Ireland in spring 2021 among people engaged in sustainable practices, three alternative understandings of time – the cycle, the flow and the link – are then brought forward and discussed. It is argued that these different time understandings are performative in that they open up opportunities for more sustainable consumption and that we should aim at a pluriversal understanding of time that could foster the evolution of social organisation and institutions, towards non-capitalist goals such as wellbeing and environmental preservation.
Optical wireless communication system performance in natural water turbulence of any strength
Authors: Yi Xiang , Liu Huanhuan , Ban Kun , Korotkova Olga
Published: October 2022

The recently introduced power spectrum model for natural water turbulence, i.e., that at any average temperature, average salinity, and stratification [J. Opt. Soc. Am. A 37, 1614 (2020)JOAOD61084-752910.1364/JOSAA.399150], is extended from weak to moderate-to-strong regimes with the help of the spatial filtering approach. Based on the extended spectrum, the expressions for the scintillation index (SI) are obtained, and based on its signal-to-noise ratio and bit error rate of the underwater wireless optical communication (UWOC) system with the on-off-keying modulation and gamma–gamma irradiance distribution model, the analysis is performed. The obtained results are compared with those derived from the widely used Nikishov and Nikishov spectrum. It is shown that the natural water turbulence results in the SI for plane (spherical) waves attaining higher maxima values at shorter propagation distances, about 20 m (40 m) with respect to 30 m (50 m) of Nikishovs turbulence. Therefore, it predicts a stronger degradation of the UWOC system performance in weak and moderate turbulence regimes.
Polarized grating transition radiation from a 2D photonic crystal
Authors: Sergeeva D. Yu. , Garaev D. I. , Tishchenko A. A.
Published: October 2022

Transition radiation (TR) is widely used as a radiation source in a wide spectral range, from terahertz to x rays. Conventional flat surfaces are usually used, but with the development of applications using microscopically structured surfaces, periodic surface structures are beginning to be studied. The periodicity of the surface dramatically changes the characteristics of TR, so this type of radiation received its own name: grating transition radiation (GTR). In this work, we investigate the polarization properties of GTR from a two-dimensional (2D) photonic crystal consisting of small particles arranged in a flat lattice (a 2D photonic crystal slab). We show theoretically that the polarization properties of GTR differ significantly from those of the kindred types of radiation: conventional TR and Smith–Purcell radiation. Since we found that the asymptotic behavior depending on the electron velocity for GTR and classical TR diverges, we performed homogenization and show that the results for GTR after homogenization are in perfect agreement with those for classical TR. This means that different dependence on the electron velocity for TR from a slab and for GTR from a 2D photonic crystal slab is caused by the fundamental difference between a conventional slab and a 2D photonic crystal due to its microscopic structure. The constructed theory contains the coordinates of the particles the photonic crystal consists of, which allows considering structures of finite size, both symmetrical and asymmetric. For asymmetric targets, the polarization of the radiation proves to be very sensitive to the electron’s trajectory. This sensibility of polarization characteristics opens up good opportunities for studying fine fundamental effects connected with the electron trajectory, such as the effect of the quantum nature of free electrons which manifests itself in the properties of radiation generated by free electrons. Also, the obtained results may find application in the design of compact sources of polarized radiation based on microscopically structured surfaces.
Light shift suppression with pulsed light detection in magnetic-state-selected cesium beam clocks
Authors: Li Yuanhao , Xu Shaohang , Chen Sifei , Liu Chang , Wang Jiale , Wang Yanhui
Published: October 2022

Light detection is widely used in atomic clocks. The simple detecting structure induces the light shift which influences the clock’s long-term stability. We introduce a new method to suppress light shift by using pulsed light instead of continuous light to detect atomic states. Under a suitable pulsed sequence, the part of the atoms which do not simultaneously interact with light and microwave field are detected. We demonstrate the validity of our approach in a magnetic-state-selected cesium beam clock. Using a well-tuned sequence, the light shift coefficient is reduced by a factor of about 10, in comparison with the continuous light detection scheme. In a clock stability test with extra light power noise, the result shows good immunity of the method to laser power fluctuations. We also analyze the sources of the clock short-term stability degradation, including the Dick effect and the fact that a reduced number of atoms is detected in the pulsed detection case.
Ridge waveguide couplers with leaky mode resonator-like wavelength responses
Authors: Schoenhardt Steffen , Boes Andreas , Nguyen Thach G. , Mitchell Arnan
Published: October 2022

Integrated photonic resonators based on bound states in the continuum (BICs) on the silicon-on-insulator (SOI) platform have the potential for novel, mass-manufacturable resonant devices. While the nature of BIC-based ridge resonators requires the resonators to be extended in the (axial) propagation direction of the resonant mode, the requirement for excitation from the quasi-continuum extends the resonator structures also in the lateral dimensions, resulting in large device footprints. To overcome this footprint requirement, we investigate the translation of BIC-based ridge resonators into a guided mode system with finite lateral dimensions. We draw analogies between the resulting waveguide system and the BIC-based resonators and numerically demonstrate that, analog to the BIC-based resonators, such a waveguide system can exhibit spectrally narrow-band inversion of its transmissive behavior.
Visible transparent mid-infrared broadband absorbers based on gradient refractive indexes and multi-size cavity resonances
Authors: Li Liang , Cui Qi , Zhang Yu-Jun , Wu Ying , Han Cai-Qin , Yan Chang-Chun
Published: October 2022

We proposed a multi-layered nanorod structure with the same tilt angle and different diameters, which has high visible transmittance and strong 3-5 µm absorption based on the principles of the gradient of the refractive index and the multi-size cavity resonances. The indium tin oxide (ITO) was selected as the target material to fabricate the structure by using a glancing angle deposition method. The experimental results show that when the deposition angle θ is 80°, swing deposition is successively done with the rotation angle φ of ±8°, ± 5°, ± 3°, and 0° on the surface of the substrate, and the quartz crystal microbalance thicknesses of ITO nanorods are 220 nm for each deposition, the average transmittance is 80.5% in the range of 400-800 nm and the integrated absorption is 86% in the 3-5 µm band. Such a simple, low-cost, and easy-to-fabricate device has potential applications in window stealth materials and other related fields.
OAM-based optical wavelet using a single pixel detection system for probing dynamic environments with application to real-time measurements of strong atmospheric turbulence
Authors: Free Justin , Dai Kunjian , Vanderschaaf Liam , Cox Michael , Miller J. Keith , Watkins Richard J. , Johnson Eric G.
Published: October 2022

This paper presents a novel method for optical probing by generating optical fields with characteristics of wavelets. The optical wavelets form a basis of rotated asymmetric beams with scaled orbital angular momentum (OAM) and beam sizes. The probing method was used experimentally to measure the continuous wavelet transform of a turbulent propagation path, giving insight into the angular properties about a fixed radius. The wavelet transform of a three-dimensional turbulence distribution was measured; the measurements are much faster than the turbulence changes, allowing characterization of an instantaneous realization of turbulence over time. Results show highly localized regions of OAM in space through the turbulence and characteristics of the turbulence can be extracted from the wavelet transforms.
Superoscillation focusing with suppressed sidebands by destructive interference
Authors: Zhang Kun , Dong Fengliang , Yan Shaokui , Xu Lihua , Hu Haifeng , Song Zhiwei , Shang Zhengguo , Zhou Yi , Liu Yufei , Wen Zhongquan , Dai Luru , Chu Weiguo , Chen Gang
Published: October 2022

Optical superoscillation, a phenomenon that the local optical field can oscillate much faster than that allowed by its highest harmonic, can significantly overcome the Abbe diffraction limit. However, as the spot size is compressed below the superoscillation criteria of 0.38λ/NA, huge sidebands will inevitably appear around the central lobe with intensity hundreds of times higher than that of the central lobe. Here, we propose an approach to realize superoscillation by using destructive interference. The central lobe size can be compressed beyond the superoscillation criteria without formation of strong sidebands by destructive interference between focused fields. Such a super-resolution metalens can find its application in label-free far-field super-resolution microscopy.
Receiver sensitivity of type-II return-to-zero signals having finite extinction ratios
Authors: Lee Jihoon , Kim Hoon
Published: October 2022

In this two-part paper, we develop expressions describing the receiver sensitivity of return-to-zero (RZ) signals having finite extinction ratios (ERs) and arbitrary duty cycles. Between the two known ways of modeling RZ signals, this work focuses on RZ pulses riding on a constant pedestal of optical power (hereinafter referred to as Type II). We find out that the sensitivity of a receiver limited by signal-dependent noise degrades as the duty cycle decreases. By contrast, an optimum duty cycle for the receiver sensitivity exists if signal-independent noise limits the receiver performance. As the duty cycle approaches 0, we discover that the signal-dependent noise dominates the signal-independent noise, regardless of the receiver used. We present the experimental results supporting our theoretical analysis.
PT symmetric single-mode line-defect photonic crystal lasers with asymmetric loss design
Authors: Wang Lingfang , Cheng Xiaotian , Zhang Xiaodong , Yu Jiawang , Xia Mingjun , Li Chenhui , Lin Xing , Liu Feng , Jin Chaoyuan
Published: October 2022

The exploration of parity-time (PT) symmetry in micro-/nano-cavity lasers has recently gained immense research interest. The PT symmetric phase transition to single-mode lasing has been achieved by arranging the spatial distribution of optical gain and loss in single or coupled cavity systems. In terms of photonic crystal (PhC) lasers, a non-uniform pumping scheme is usually employed to enter the PT symmetry-breaking phase in a longitudinal PT symmetric system. Instead, we use a uniform pumping scheme to enable the PT symmetric transition to the desired single lasing mode in line-defect PhC cavities based on a simple design with asymmetric optical loss. The flexible control of gain–loss contrast is realized by removing a few rows of air holes in PhCs. We obtain single-mode lasing with a side mode suppression ratio (SMSR) of around 30 dB without affecting the threshold pump power and linewidth. The output power of the desired mode is six times higher than that in multimode lasing. This simple approach enables single-mode PhC lasers without sacrificing the output power, threshold pump power, and linewidth of a multimode cavity design.
Effect of the AlN strain compensation layer on InGaN quantum well red-light-emitting diodes beyond epitaxy
Authors: Liu Zhiyuan , Nong Mingtao , Lu Yi , Cao Haicheng , Yuvaraja Saravanan , Xiao Na , Alnakhli Zahrah , Aguileta Vázquez Raul Ricardo , Li Xiaohang
Published: October 2022

An atomically thick AlN layer is typically used as the strain compensation layer (SCL) for InGaN-based-red light-emitting diodes (LEDs). However, its impacts beyond strain control have not been reported, despite its drastically different electronic properties. In this Letter, we describe the fabrication and characterization of InGaN-based red LEDs with a wavelength of 628 nm. A 1-nm AlN layer was inserted between the InGaN quantum well (QW) and the GaN quantum barrier (QB) as the SCL. The output power of the fabricated red LED is greater than 1 mW at 100 mA current, and its peak on-wafer wall plug efficiency (WPE) is approximately 0.3%. Based on the fabricated device, we then used numerical simulation to systematically study the effect of the AlN SCL on the LED emission wavelength and operating voltage. The results show that the AlN SCL enhances the quantum confinement and modulates the polarization charges, modifying the device band bending and the subband energy level in the InGaN QW. Thus, the insertion of the SCL considerably affects the emission wavelength, and the effect on the emission wavelength varies with the SCL thickness and the Ga content introduced into the SCL. In addition, the AlN SCL in this work reduces the LED operating voltage by modulating the polarization electric field and energy band, facilitating carrier transport. This implies that heterojunction polarization and band engineering is an approach that can be extended to optimize the LED operating voltage. We believe our study better identifies the role of the AlN SCL in InGaN-based red LEDs, promoting their development and commercialization.
Spectrally programmable Raman fiber laser with adaptive wavefront shaping
Authors: Zhang Yanli , Wang Shanshan , She Mingzhu , Rao Yunjiang , Zhang Weili
Published: October 2022

Raman fiber lasers (RFLs) have broadband tunability due to cascaded stimulated Raman scattering, providing extensive degrees of freedom for spectral manipulation. However, the spectral diversity of RFLs depends mainly on the wavelength flexibility of the pump, which limits the application of RFLs. Here, a spectrally programmable RFL is developed based on two-dimensional spatial-to-spectral mapping of light in multimode fibers (MMFs). Using an intracavity wavefront shaping method combined with genetic algorithm optimization, we launch light with a selected wavelength(s) at MMF output into the active part of the laser for amplification. In contrast, the light of undesired wavelengths is blocked. We demonstrate spectral shaping of the high-order RFL, including a continuously tunable single wavelength and multiple wavelengths with a designed spectral shape. Due to the simultaneous control of different wavelength regions, each order of Raman Stokes light allows flexible and independent spectral manipulation. Our research exploits light manipulation in a fiber platform with multi-eigenmodes and nonlinear gain, mapping spatial control to the spectral domain and extending linear light control in MMFs to active light emission, which is of great significance for applications of RFLs in optical imaging, sensing, and spectroscopy.
Shared biophysical mechanisms determine early biofilm architecture development across different bacterial species
Authors: Jeckel Hannah , Díaz-Pascual Francisco , Skinner Dominic J. , Song Boya , Jiménez-Siebert Eva , Strenger Kerstin , Jelli Eric , Vaidya Sanika , Dunkel Jörn , Drescher Knut
Published: October 2022

Bacterial biofilms are among the most abundant multicellular structures on Earth and play essential roles in a wide range of ecological, medical, and industrial processes. However, general principles that govern the emergence of biofilm architecture across different species remain unknown. Here, we combine experiments, simulations, and statistical analysis to identify shared biophysical mechanisms that determine early biofilm architecture development at the single-cell level, for the speciesVibrio cholerae,Escherichia coli,Salmonella enterica, andPseudomonas aeruginosagrown as microcolonies in flow chambers. Our data-driven analysis reveals that despite the many molecular differences between these species, the biofilm architecture differences can be described by only 2 control parameters: cellular aspect ratio and cell density. Further experiments using single-species mutants for which the cell aspect ratio and the cell density are systematically varied, and mechanistic simulations show that tuning these 2 control parameters reproduces biofilm architectures of different species. Altogether, our results show that biofilm microcolony architecture is determined by mechanical cell–cell interactions, which are conserved across different species.
Global genome decompaction leads to stochastic activation of gene expression as a first step toward fate commitment in human hematopoietic cells
Authors: Parmentier Romuald , Racine Laëtitia , Moussy Alice , Chantalat Sophie , Sudharshan Ravi , Papili Gao Nan , Stockholm Daniel , Corre Guillaume , Fourel Geneviève , Deleuze Jean-François , Gunawan Rudiyanto , Paldi Andras
Published: October 2022

When human cord blood–derived CD34+ cells are induced to differentiate, they undergo rapid and dynamic morphological and molecular transformations that are critical for fate commitment. In particular, the cells pass through a transitory phase known as “multilineage-primed” state. These cells are characterized by a mixed gene expression profile, different in each cell, with the coexpression of many genes characteristic for concurrent cell lineages. The aim of our study is to understand the mechanisms of the establishment and the exit from this transitory state. We investigated this issue using single-cell RNA sequencing and ATAC-seq. Two phases were detected. The first phase is a rapid and global chromatin decompaction that makes most of the gene promoters in the genome accessible for transcription. It results 24 h later in enhanced and pervasive transcription of the genome leading to the concomitant increase in the cell-to-cell variability of transcriptional profiles. The second phase is the exit from the multilineage-primed phase marked by a slow chromatin closure and a subsequent overall down-regulation of gene transcription. This process is selective and results in the emergence of coherent expression profiles corresponding to distinct cell subpopulations. The typical time scale of these events spans 48 to 72 h. These observations suggest that the nonspecificity of genome decompaction is the condition for the generation of a highly variable multilineage expression profile. The nonspecific phase is followed by specific regulatory actions that stabilize and maintain the activity of key genes, while the rest of the genome becomes repressed again by the chromatin recompaction. Thus, the initiation of differentiation is reminiscent of a constrained optimization process that associates the spontaneous generation of gene expression diversity to subsequent regulatory actions that maintain the activity of some genes, while the rest of the genome sinks back to the repressive closed chromatin state.
Enhanced mosquito vectorial capacity underlies the Cape Verde Zika epidemic
Authors: Rose Noah H. , Dabo Stéphanie , da Veiga Leal Silvânia , Sylla Massamba , Diagne Cheikh T. , Faye Oumar , Faye Ousmane , Sall Amadou A. , McBride Carolyn S. , Lambrechts Louis
Published: October 2022

The explosive emergence of Zika virus (ZIKV) across the Pacific and Americas since 2007 was associated with hundreds of thousands of human cases and severe outcomes, including congenital microcephaly caused by ZIKV infection during pregnancy. Although ZIKV was first isolated in Uganda, Africa has so far been exempt from large-scale ZIKV epidemics, despite widespread susceptibility among African human populations. A possible explanation for this pattern is natural variation among populations of the primary vector of ZIKV, the mosquito Aedes aegypti. Globally invasive populations of Ae. aegypti outside of Africa are considered effective ZIKV vectors because they are human specialists with high intrinsic ZIKV susceptibility, whereas African populations of Ae. aegypti across the species’ native range are predominantly generalists with low intrinsic ZIKV susceptibility, making them less likely to spread viruses in the human population. We test this idea by studying a notable exception to the patterns observed across most of Africa: Cape Verde experienced a large ZIKV outbreak in 2015 to 2016. We find that local Ae. aegypti in Cape Verde have substantial human-specialist ancestry, show a robust behavioral preference for human hosts, and exhibit increased susceptibility to ZIKV infection, consistent with a key role for variation among mosquito populations in ZIKV epidemiology. These findings suggest that similar human-specialist populations of Ae. aegypti in the nearby Sahel region of West Africa, which may be expanding in response to rapid urbanization, could serve as effective vectors for ZIKV in the future.
Characterizing acceptable and appropriate implementation strategies of a biobehavioral survey among men who have sex with men and others assigned male who have sex with men in Zimbabwe
Authors: Parmley Lauren E. , Miller Sophia S. , Harris Tiffany G. , Mugurungi Owen , Rogers John H. , Hakim Avi , Musuka Godfrey , Chingombe Innocent , Mapingure Munyaradzi
Published: October 2022

Key populations including men who have sex with men (MSM), female sex workers, people who inject drugs, transgender persons, and prisoners account for nearly 50% of new HIV infections globally. To inform the HIV response and monitor trends in HIV prevalence and incidence among key populations, countries have increased efforts to implement biobehavioral surveys (BBS) with these groups as part of routine surveillance. Yet the marginalized nature of populations participating in a BBS requires contextually acceptable and appropriate strategies for effective implementation. We conducted a formative assessment to inform the first BBS conducted with MSM and others assigned male who have sex with men (OAMSM) in Zimbabwe, where same-sex sexual behaviors are illegal and highly stigmatized and describe applications of our findings. Qualitative data were collected through four focus groups with 32 MSM/OAMSM and 25 in-depth interviews (15 MSM/OAMSM, 10 service providers/gatekeepers) from December 2018 to January 2019. Rapid assessment techniques were employed including rapid identification of themes from audio recordings and review of detailed field notes and memos to identify key themes. Findings from this assessment included contextually relevant considerations including behaviors and terminology to avoid when working with MSM/OAMSM in Zimbabwe, appropriate compensation amounts for survey participation, proposed data collection sites, and differences in sexual openness, marital status, and networks among younger and older MSM/OAMSM. Participants also reported strong network ties suggesting respondent-driven sampling—a peer chain referral approach—to be an appropriate recruitment method in this context. Taken together, these findings highlighted key considerations and strategies for implementation to ensure the subsequent BBS in Zimbabwe was both acceptable and appropriate. These results and applications of these results are important for informing surveillance efforts and broader HIV-related engagement efforts among MSM/OAMSM in Zimbabwe as well as in other contextually similar countries in Southern Africa.
Remdesivir does not affect mitochondrial DNA copy number or deletion mutation frequency in aged male rats: A short report
Authors: Herbst Allen , Choi Solbie , Hoang Austin N. , Kim Chiye , Martinez Moreno Diana , McKenzie Debbie , Aiken Judd M. , Wanagat Jonathan
Published: October 2022

Remdesivir is a leading therapy in patients with moderate to severe coronavirus 2 (SARS-CoV-2) infection; the majority of whom are older individuals. Remdesivir is a nucleoside analog that incorporates into nascent viral RNA, inhibiting RNA-directed RNA polymerases, including that of SARS-CoV-2. Less is known about remdesivir’s effects on mitochondria, particularly in older adults where mitochondria are known to be dysfunctional. Furthermore, its effect on age-induced mitochondrial mutations and copy number has not been previously studied. We hypothesized that remdesivir adversely affects mtDNA copy number and deletion mutation frequency in aged rodents. To test this hypothesis, 30-month-old male F333BNF1 rats were treated with remdesivir for three months. To determine if remdesivir adversely affects mtDNA, we measured copy number and mtDNA deletion frequency in rat hearts, kidneys, and skeletal muscles using digital PCR. We found no effects from three months of remdesivir treatment on mtDNA copy number or deletion mutation frequency in 33-month-old rats. These data support the notion that remdesivir does not compromise mtDNA quality or quantity at old age in mammals. Future work should focus on examining additional tissues such as brain and liver, and extend testing to human clinical samples.
Evaluation and construction of the capacities of urban innovation chains based on efficiency improvement
Authors: Zhang Rui , Ji Changxu , Tan Liguo , Sun Yuqin
Published: October 2022

This study examines urban innovation activities from the perspective of improving the efficiency of innovation chains and explored their operational patterns. The connotation of the urban innovation chain was analyzed following the process of the innovation chain and the characteristics of urban innovation activities. The urban innovation chain can be divided into the following three stages: original, technological, and innovation transformation. An indicator system for evaluating the three capacities of the urban innovation chain was established. Furthermore, the development level of strategic emerging industries was used as an indicator to measure the chain’s efficiency and analyze the relationship between these three constructed capacities in Chinese national innovative cities. Data published on the national innovative cities were used to measure the capacity of the urban innovation chain. The development of Strategic emerging industries indicates cities’ innovation performance, and an inductive approach was applied to analyze the relationship between the capacity construction of the urban innovation chain and innovation performance in innovative cities. This study found that the capacity of the urban innovation chain positively affected urban innovation performance and that the balanced development of the three capacities positively affected urban innovation performance. When urban innovation performance was at its highest, the contribution of original innovation capacity to innovation performance was significantly greater than that of the other two capacities; thus, an inverted U-curve illustrates the relationship between the improvement of urban innovation performance and the balance of the three capacities of the urban innovation chain. This study’s conclusions enrich the relevant theories of the innovation chain, provide a reference for the construction of the urban innovation chain, and promote the development of Strategic emerging industries.
Temperature and settlement characteristics of graded crushed-rock layer for runway engineering in permafrost regions
Authors: Liu Xiaolan , Fu Chuanwei , Li Shunqun
Published: October 2022

To maintain the temperature and settlement stability of a subgrade, a combination of graded crushed rock layer and insulation layer may be applied to optimize pavement structures. This study verifies a proposed numerical model of pavement and subgrade design in permafrost regions and evaluates temperature and settlement characteristics at different particle size and thickness of graded crushed rock layer and different thickness and location of insulation layer. The results show that the temperature and settlement of the combination of graded crushed-rock layer and insulation layer decrease significantly as the particle diameter and thickness of graded crushed-rock layer increase, and vary little when the thickness of insulation layer is more than 0.15 m. The location of installation layer has significant influence on the temperature of the subbase layer, but has little influence on the temperature of the subgrade. The maximum settlement of the pavement structure and subgrade decreases when the installation layer varies from the top of the subbase layer to the bottom of the subbase layer. The optimal combination of graded crushed-rock layer and insulation layer is that the 0.15 m-thickness installation layer is at the bottom of the 0.50 m-thickness graded crushed-rock layer with the particle size of 6–8 cm. This study provides a theoretical basis for the design, construction, operation, maintenance, and safety management of airport runways in permafrost regions.
The secret life of baby turtles: A novel system to predict hatchling emergence, detect infertile nests, and remotely monitor sea turtle nest events
Authors: Clabough Erin B. D. , Kaplan Eric , Hermeyer David , Zimmerman Thomas , Chamberlin Joshua , Wantman Samuel
Published: October 2022

Current understanding of sea turtle nesting, hatching, and emergence events has been largely limited to observable events on the surface of the sand, though recent approaches using audio or visual equipment have allowed scientists to better understand some underground nest phenomena. We used a technology-based approach to define motion-related Caretta caretta hatching and emergence nest events. We describe a novel low-cost, accelerometer-based system called TurtleSense that can detect movement and temperature within sea turtle nests remotely. TurtleSense is successfully able to specifically detect motion within sea turtle nests over the entire course of incubation. This system allows for the identification of infertile nests and the detection of four predictable sequential developmental activity patterns in viable nests, including a hatch and posthatch period, the timing of which can be used to tightly predict hatchling emergence events almost to the day. TurtleSense provides a much better understanding about what is happening in the nest before emergence and allows for the generation of a theory of the mechanism that triggers mass emergence. Our results suggest that motion plays a large role in hatchling communication and that the timing of emergence events may be related to the cessation of movement within the nest. Current management of sea turtle nesting events is primarily driven by counting the number of days since the nest was laid, with further safeguards placed at the nest upon subsequent visual observation of depression or emergence events. Use of TurtleSense technology can impact nest management and conservation efforts, allowing organizations to use this motion data to more tightly predict emergence dates for sea turtle hatchlings and to use viability data to inform nest management decisions.
Job satisfaction among healthcare workers in the aftermath of the COVID-19 pandemic
Authors: Barili Emilia , Bertoli Paola , Grembi Veronica , Rattini Veronica
Published: October 2022

Using a unique survey of more than 7,000 respondents conducted immediately after the first wave of the COVID-19 pandemic in Italy, we investigate potential drivers of the job satisfaction of healthcare workers. Relying on a representative sample of Italian physicians and nurses, we show that, in addition to personal characteristics (e.g., age, gender, health status), contextual factors (i.e., working conditions) play the leading role in explaining variation in the level of satisfaction (58%). In particular, working in a high-quality facility increases worker satisfaction and willingness to remain in the profession, and in the current medical specialization, while working in a province with a perceived shortage of medical personnel yields the opposite result. Direct experience with COVID-19 (e.g., having tested positive) is not significantly correlated with the level of job satisfaction, which is instead significantly reduced by changes in the working conditions caused by the health emergency.
“Men are the head of the family, the dominant head”: A mixed method study of male involvement in maternal and child health in a patriarchal setting, Western Nigeria
Authors: Okafor Ifeoma Peace , Chukwudi Chioma Lilian , Igwilo Ugonnaya Ugochinyere , Ogunnowo Babatunde Enitan
Published: October 2022

Introduction

The importance of involving men in reproductive, maternal and child health (RMCH) programs is increasingly recognized globally. In Nigeria, most MCH services do not actively engage fathers.

Aim

To assess men’s knowledge, involvement in MCH and the barriers in Southwest Nigeria. Predictors of good knowledge and involvement were also assessed.

Methods

This was a community-based cross sectional study. Quantitative and qualitative methods were used in data collection which was done within a period of three months in 2018. Quantitative data were collected with interviewer administered questionnaires from 418 respondents who were selected by multistage sampling methodology. The topic was further explored using focus group discussion (FGD). Quantitative data were analysed using EPI-INFO version 7. Quantitative variables were summarized using means and standard deviations while multivariable analysis was carried out to determine predictors of good knowledge and involvement in MCH. A combination of deductive and inductive analysis was used for the qualitative data.

Results

Overall, 65% of men had good knowledge of MCH while 60.8% had good involvement. Predictors of good knowledge were being a Christian (AOR 1.674, 95% CI 1.045–2.679), being of Yoruba tribe (AOR 1.753, 95% CI 1.100–2.796), having post-secondary education (AOR 1.984, 95% CI 1.002–3.928), having more under-fives in the household (AOR 2.162 95% CI 1.365–3.425) and spouse having post-secondary education (AOR 2.755, 95% CI 1.189–6.382). Predictors of good involvement in MCH include higher educational level of spouse: secondary (AOR 2.852, 95% CI 1.214–6.699), post-secondary (AOR 2.270, 95% CI 1.000–5.161) and having good knowledge of MCH (AOR 2.518, 95% CI 1.587–3.994). From the FGD, other factors which influence involvement were related to traditional/cultural orientation, time constraint and finance among others.

Conclusion

Men’s knowledge and their involvement in maternal and child health were sub-optimal. For improvement, community-based intervention programmes should be designed for men and implemented, taking into consideration their traditional/cultural roles, religious orientation, busy schedules, and educational backgrounds. They should be re-oriented on their patriarchally informed belief about their perceived roles in RMCH.