bluuebunny/crossref_metadata_2025 huggingface dataset:
Pandemics, Labor Relations, and Political Regimes: The Bubonic Plague and COVID-19 Crises in India
Authors: Sarkar Aditya
Published: May 2023

This article investigates the possibility of comparisons between the COVID-19 crisis in India and an earlier episode of pandemic crisis: bubonic plague in Bombay at the end of the nineteenth century. There are numerous apparent parallels. In both cases, Indians experienced an unprecedented and sweeping use of state authority to enforce minute regulations of everyday life. These regulations, on both occasions, were nominally universal in their scope but in practice bore most heavily on the working classes and specifically the urban poor. During both pandemic crises, the immediate consequence of the strategy of state control chosen was a massive flight of the urban poor: from Bombay between 1896 and 1898, and from many of India's major urban centers in the summer of 2020. The parallels and convergences mentioned above provide a basis for comparison. But they do no more than that: the emphasis of the analysis that follows is on the contrasts between the two pandemic crises. It is these contrasts between the two episodes, rather than the superficially more striking similarities, which offer a basis for reflection on the character of the respective crises. These reflections focus, at their core, on the mode of authoritarian state policy deployed in the two cases, and on the predicament of laboring classes during the two cycles of pandemic crisis.
Shaping the future of male reproductive health: fostering talent at the 14th Network of Young Researchers in Andrology meeting
Authors: Marcu Daniel , Egeberg Dorte , Richer Guillaume , Oud Manon , Houston Brendan , Berres Sven , de la Iglesia Alberto
Published: May 2023

The 14th Network of Young Researchers in Andrology (NYRA) meeting was a 2-day conference held at the University of East Anglia in Norwich, UK, organized by the NYRA. The meeting brought together researchers and experts to discuss and exchange ideas on male infertility and spermatogenesis. The meeting covered a wide range of topics related to male germline research, including the impact of mutations in the male germline on future generations, the use of innovative sequencing tools for the study of male infertility, and the intricate germline epigenome. The impact of aging on spermatogenesis was also discussed, with a focus on the increased DNA fragmentation rates, changes in DNA methylation patterns, and longer telomeres associated with aging sperm. Additionally, progress on fertility preservation options for children undergoing gonadotoxic cancer treatments was presented. The meeting also featured workshops on leadership and career development strategies in science, providing a valuable opportunity for young researchers to learn from experts in the field and exchange ideas with their peers. Overall, the meeting provided a platform for researchers to discuss the latest developments in male germline research, highlighting the importance of empowering young researchers to tackle male reproductive health.
Reputation and Partial Default
Authors: Amador Manuel , Phelan Christopher
Published: May 2023

This paper presents a continuous-time reputation model of sovereign debt allowing for both varying levels of partial default and full default. In it, a government can be a nonstrategic commitment type or a strategic opportunistic type, and a government’s reputation is its equilibrium Bayesian posterior of being the commitment type. Our equilibrium has that for bond levels reachable by both types without defaulting, bigger partial defaults (or bigger haircuts for bond holders) imply higher interest rates for subsequent bond issuances, as in the data. (JEL D83, E32, E43, G12, H63)
Should We Tax Capital Income or Wealth?
Authors: Boar Corina , Midrigan Virgiliu
Published: May 2023

We study optimal capital income and wealth taxation in an economy that reproduces the importance of private businesses for output and inequality. If entrepreneurs are subject to collateral constraints, they face heterogeneous rates of return, which generate a meaningful distinction between capital income and wealth taxation. We find that taxing capital income is preferable to taxing wealth because the efficiency gains from wealth taxation are swamped by the redistributional benefits of taxing the profits of richer entrepreneurs. Consequently, the gains from taxing wealth are modest. This conclusion is robust to the planner’s preference for redistribution and allowing for nonlinear taxes. (JEL D31, H21, H23, H24, H25, K34, L26)
Acoustic scattering properties of seagrass: In/ex-situ measurements of Posidonia oceanica
Authors: MUTLU Erhan , Olguner Cansu
Published: May 2023

The marine prairies are paramount to the marine ecosystem playing a crucial role in various ways. Owing to the global atmospheric events inducing hydrospheric changes, marine seaweeds have been negatively affected and are vulnerable. Conventional methods (SCUBA), which were previously used to collect seagrasses, have become a destructive method for deriving unrecoverable damages for their stocks and have been replaced with remote sensing methods. Considering the advantages of the acoustic methods, two different in/ex-situ experiments were conducted to ground-truth the common seagrass, P. oceanica, in time and space of the Turkish Mediterranean water in 2011-2012 using a scientific echosounder with a split beam transducer operated at a frequency of 206 kHz. After the separation of the seagrass from spurious scatterers, the acoustic parameters (Sa: area backscattering strength, Sv: volume backscattering strength, and TS: Target Strength) were correlated and regressed with the biometric variables (Leaf Area Index, biomass, volume, length, width, diameter, or thickness) of different parts (leaf, rhizome, and sheath) of the seagrass. Estimation of biometrics by acoustic methods has been considered a challenge up to now. Statistical relationships between biometrics and acoustics were precisely examined for the species. The relationships were linearly established in the acoustic geometric region. There was a seasonal difference in the relationships. Their rhizomes and sheaths were considered unstable non-linear parts and remained unexplained for the acoustic response. Acoustic response to the leaf density (d, g cm-3), which was a distinguished component in the reflection, was found to be dependent on the seasonal biological activities of P. oceanica. Posidonia, which has a d greater than 1 g/cm3, produced the geometric region. The present study was the first attempt to establish the relationships of the seagrass under protection, and can decrease usage of destructive methods for future studies.
Barriers and facilitators to maternal death surveillance and response at a busy urban National Referral Hospital in Uganda
Authors: Namagembe Imelda , Beyeza-Kashesya Jolly , Rujumba Joseph , K.Kaye Dan , Mukuru Moses , Kiwanuka Noah , Moffett Ashley , Nakimuli Annettee , Byamugisha Josaphat
Published: May 2023

Background: Preventable maternal and newborn deaths remain a global concern, particularly in low- and- middle-income countries (LMICs) Timely maternal death surveillance and response (MDSR) is a recommended strategy to account for such deaths through identifying contextual factors that contributed to the deaths to inform recommendations to implement in order to reduce future deaths. Implementation of MDSR is still suboptimal due to barriers such as inadequate skills and leadership to support MDSR.

With the leadership of WHO and UNFPA, there is momentum to roll out MDSR, however, the barriers and enablers for implementation have received limited attention. These have  implications for successful implementation. The aim of this study was: To assess barriers and facilitators to implementation of MDSR at a busy urban National Referral Hospital as perceived by health workers, administrators, and other partners in Reproductive Health.

Methods: Qualitative study using in-depth interviews (24), 4 focus-group discussions with health workers, 15 key-informant interviews with health sector managers and implementing partners in Reproductive-Health. We conducted thematic analysis drawing on the Theory of Planned Behaviour (TPB).  

Results: The major barriers to implementation of MDSR were: inadequate knowledge and skills; fear of blame / litigation; failure to implement recommendations; burn out because of workload   and inadequate leadership- to support health workers. Major facilitators were involving all health workers in the MDSR process, eliminate blame, strengthen leadership, implement recommendations from MDSR and functionalize lower health facilities (especially Health Centre -IVs).

Conclusions: The barriers of MDSR include knowledge and skills gaps, fear of blame and litigation, and other health system factors such as erratic emergency supplies, and leadership/governance challenges.

Recommendation: Efforts to strengthen MDSR for impact should use health system responsiveness approach to address the barriers identified, constructive participation of health workers to harness the facilitators and addressing the required legal framework.
On the distribution of the greatest common divisor of the elements in integral part sets
Authors: Srichan Teerapat
Published: May 2023

It is a classical result that the probability that two positive integers n, m ≤ x are relatively prime tends to 1/ζ(2) = 6/π2 as x → ∞. In this paper, the same result is still true when n and m are restricted to sub-sequences, i.e. Piatetski–Shapiro sequence, Beatty sequence and the floor function set.
(ψ, ϕ)-Wardowski contraction for three maps in Gb-metric spaces
Authors: Puvar Sejal , Vyas Rajendra G.
Published: May 2023

Introducing (ψ, ϕ) − Gb-Wardowski contraction for three maps, a common fixed point result is obtained for complete Gb-metric spaces. An application related to discontinuous activation function in neural network is also established.
On the identities of Ramanujan – a q-series approach
Authors: Bhaskar Srivastava
Published: May 2023

The idea of this paper is to prove two general theorems using q-series and deduce some partial theta identities and false theta identities. Some of the identities of Ramanujan come as special cases.
3D-Printed models as an improvement in medical professionals' education
Authors: Jachimczyk Jakub , Homa Piotr
Published: May 2023

Increasing usage of 3D-Printed models draws attention as a cheap alternative to traditional tools used in anatomy education and post-graduate training. Models can be self-prepared using existing DICOM files and printed on consumer-level printers using widely available materials. Prepared models benefit from high approval rate from students, multiplicity of printable structures and high detail accuracy. They can be used in wide range of medical training, for e.g., otolaryngology, neurosurgery, oncology, neuroradiology. Positive outcomes include greater eligibility for resident training, surgical planning and education, when compared to market available anatomical models. Additive manufacturing is expected to increase its presence in medical education.
PAISAJES CONTEMPORÁNEOS DE LA ABSTRACCIÓN GEOMÉTRICA: LA RETÍCULA EN EL ESPACIO ESCÉNICO
Authors: González Cubero Josefina
Published: May 2023

La retícula es el soporte conceptual y formal utilizado como paradigma de la modernidad en las artes plásticas durante el siglo xx, presente avant la lettre en la arquitectura, y un elemento de rezagada incorporación a la escenografía en la concepción del espacio escénico, aun nutriéndose de ellas. Ante su escasa y esporádica presencia en la escena en el pasado siglo, el artículo expone el aliento que adquiere en su ocaso y las formas que adopta en el siglo actual, fundamentalmente en la práctica escenográfica clásica en el teatro a la italiana. A través de una sucinta selección de ejemplos, y aplicando una metodología analítica y comparativa, se aporta un examen y taxonomía de cómo la retícula se ha denotado en el espacio escénico y qué ha connotado como sistema significante. El teatro de texto, la ópera y la danza son los territorios artísticos de las artes escénicas que se han recorrido, para desvelar los aspectos funcionales, plásticos y significativos de los paisajes de la abstracción geométrica configurados por la retícula.
ENTRE VANGUARDIA Y TRADICIÓN. ESCENOGRAFÍAS DE ETTORE FAGIUOLI EN LA ARENA DE VERONA
Authors: Frigo Elia , Tejedor Cabrera Antonio , Linares Gómez del Pulgar Mercedes
Published: May 2023

El artículo indaga en los aspectos compositivos y operativos de las escenografías del arquitecto Fagiuoli en la Arena de Verona a lo largo de su dilatada actividad como escenógrafo, entre 1913 y 1950. La postura pragmática y cuidadosa de Fagiuoli es fruto de una visión amplia que tiene en cuenta los múltiples problemas que el anfiteatro presenta a la hora de proyectar una escenografía. El arquitecto no se posiciona de manera clara dentro de una u otra corriente artística y valora cada obra como un desafío en sí mismo, consciente de su complejidad y de una resolución que se impone mediante una serie de herramientas de proyecto que se han ido acumulando a lo largo de la historia. A través de un recorrido cronológico por sus escenografías, se detectan las herramientas formales, compositivas y escenotécnicas utilizadas, así como la evolución del lenguaje arquitectónico, considerando los aspectos característicos de la Arena de Verona y la necesaria relación arquitectónica del decorado escénico con el anfiteatro.
The Impact of Financial Stress on Workplace Harassment and Discrimination
Authors: Narayan Ayushi
Published: May 2023

I study the impact of financial stress on the incidence of harassment and discrimination using Equal Employment Opportunity (EEO) charges brought forward by U.S. Postal Service workers. An analysis of more than 800,000 EEO charges filed between 2004 and 2019 demonstrates that financial stress experienced in the second week of the pay cycle increases EEO incidents by about 5% compared with the first week. Further analyses suggest that the uncovered effects are driven by changes in the number of incidents rather than in their reporting.

This paper was accepted by Yan Chen, behavioral economics and decision analysis.

Funding: This work was supported by the Laboratory for Economic Analysis and Policy at Harvard University and a James M. and Cathleen D. Stone PhD Scholar fellowship from the Multidisciplinary Program in Inequality & Social Policy.

Supplemental Material: The data files and online appendix are available at https://doi.org/10.1287/mnsc.2023.4815 .
Best Principal Submatrix Selection for the Maximum Entropy Sampling Problem: Scalable Algorithms and Performance Guarantees
Authors: Li Yongchun , Xie Weijun
Published: May 2023

This paper studies a classic maximum entropy sampling problem (MESP), which aims to select the most informative principal submatrix of a prespecified size from a covariance matrix. MESP is widely applied to many areas, including healthcare, power systems, manufacturing, and data science. By investigating its Lagrangian dual and primal characterization, we derive a novel convex integer program for MESP and show that its continuous relaxation yields a near-optimal solution. The results motivate us to study efficient approximation algorithms and develop their approximation bounds for MESP, which improves the best known one in the literature.
Financial inclusion and tax effort in sub-Saharan Africa: the role of institutional quality
Authors: Zallé Oumarou
Published: May 2023

Addressing growth challenges in developing countries requires mobilising domestic resources in the face of declining external financing. This paper explores the effects of financial inclusion on tax efforts in sub-Saharan Africa, conditioned by institutional quality. To do this, a finite mixture model that takes into account the potential presence of unobserved heterogeneity was estimated based on a sample taken from 43 countries over the 1996–2019 period. Tax effort scores were constructed using several stochastic frontier models. The results show that the impact of financial inclusion on tax efforts differs across country groups. For example, financial inclusion stimulates tax effort in sub-Saharan Africa in 93.8 per cent of cases and inhibits tax effort in only 6.2 per cent of cases. These results are robust to several sensitivity tests. This paper highlights the need for countries in sub-Saharan Africa to improve access to financial systems by increasing mobile banking coverage and accessibility and reducing financial services costs. These countries should also look to capitalise on the benefits of financial inclusion by protecting political rights and fighting corruption.
Thresholds of repression and criminalisation of oppositional political activism in the Israeli settler state: a preliminary investigation
Authors: Weizman Elian
Published: May 2023

This article investigates processes of criminalisation and mechanisms of repression and control of oppositional political activism of Israel’s citizens, both Palestinians and Jews, given the state’s particular political formation as a ‘liberal settler state’ (Robinson, 2013). In order to do so, the article traces the ‘threshold of threat’ that leads to criminalisation and repression in Israel. I argue that the process of criminalisation and repression is tied with the construction of the concept of ‘threat’ and is always bound with race-making. Further, the article treats criminalisation as a multilayered process involving both state and non-state actors, and a range of informal and formal strategies. I further argue that the operational logic of the settler state dictates the strategies used to tolerate, contain, limit or crush dissent altogether. Since the Israeli state strives to maintain privileges to its Jewish citizenry, we can trace more reliance on ‘informal’ strategies of criminalisation towards its Jewish citizens, led by civil society organisations and actors, while the ‘formal’ strategies, led by the state, are preserved almost exclusively for dealing with Palestinian political activism. Finally, I argue that unravelling processes of criminalisation and oppression, triggered by the crossing of the threshold of threat, exposes state vulnerabilities and fragility. By tracing the shifting thresholds of threat we gain a window into the precarity of such a system of power and how it can be challenged and transformed. We can also learn what opportunities for resistance exist and what ‘openings’ must be seized.
Decommissioning: another critical challenge for energy transitions
Authors: Partridge Tristan , Barandiaran Javiera , Triozzi Nick , Toni Valtierra Vanessa
Published: May 2023

To achieve the dual goals of minimising global pollution and meeting diverse demands for environmental justice, energy transitions need to involve not only a shift to renewable energy sources but also the safe decommissioning of older energy infrastructures and management of their toxic legacies. While the global scale of the decommissioning challenge is yet to be accurately quantified, the climate impacts are significant: each year, more than an estimated 29 million abandoned oil and gas wells around the world emit 2.5 million tons of methane, a potent greenhouse gas. In the US alone, at least 14 million people live within a mile of an abandoned oil or gas well, creating pollution that is concentrated among low-income areas and communities of colour. The costs involved in decommissioning projects are significant, raising urgent questions about responsibility and whether companies who have profited from the sale of extracted resources will be held liable for clean-up, remediation and management costs. Recognising these political goals and policy challenges, this article invites further research, scrutiny and debate on what would constitute the successful and safe decommissioning of sites affected by fossil fuel operations – with a particular focus on accountability, environmental inequality, the temporality of energy transitions, and strategies for phasing out or phasing down fossil fuel extraction.
Examining the change of half-period voltage in longitudinal electro-optic modulation and residual stress of potassium dihydrogen phosphate crystal
Authors: Liu Hui , Gao Zeliang , Wang Shenglai , Li Xianglin , Li Weidong , Wang Duanliang , Huang Pingping , Xu Longyun , Zhang Liyuan , Wang Bo
Published: May 2023

In this paper, the voltage-transmittance curvesKDP crystals were
measured accurately between two crossed or parallel polarizers using
longitudinal electro-optic effect. The end faces of rectangular KDP
samples were coated with ring-shaped electrodes using conductive
silver paint (CSP). The change of half period voltage U
i
has been investigated. A method for
quantitative characterization of residual stress has been proposed,
based on deviation voltage U
d
. The results demonstrate that loading
voltage is close to the integration of electric field intensity in
crystal along the optical path when the CSP ring electrodes have a
large outer radius R, small inner radius r, and long-distance d. The half-period voltage U
i
is also close to longitudinal
half-wave voltage U
π
in these circumstances. The unclamped
electro-optic coefficient γ63
σ
of KDP crystal at room temperature
was measured as 10.24±0.05pm/V at the wavelength of
632.8 nm.
Remote sensing oil in water with an all-fiber underwater single-photon Raman lidar
Authors: Shangguan Mingjia , Yang Zhifeng , Shangguan Mingyu , Lin Zaifa , Liao Zhuoyang , Guo Yirui , Liu Chuan
Published: May 2023

The detection of oil in water is of great importance for maintaining subsurface
infrastructures such as oil pipelines. As a potential technology for
oceanic application, an oceanic lidar has proved its advantages for
remote sensing of optical properties and subsea materials. However,
current oceanic lidar systems are highly power-consuming and bulky,
making them difficult to deploy underwater to monitor oil in water. To
address this issue, we have developed a compact single-photon Raman
lidar by using a single-photon detector with high quantum efficiency
and low dark noise. Due to the single-photon sensitivity, the
detection of the relatively weak Raman backscattered signal from
underwater oil was realized with a laser with a pulse energy of
1 µJ and a telescope with a diameter of 22.4 mm. An
experimental demonstration was conducted to obtain the
distance-resolved Raman backscatter of underwater oil of different
thicknesses up to a distance of 12 m. The results indicate the
single-photon Raman lidar’s potential for inspecting underwater oil
pipelines.
High-detection-efficiency stereo microscope system based on a mobile phone
Authors: Guo Xinran , Chang Jun , Chen Weilin , Hu Yaoyao , Ma Ning , Zhang Jianping
Published: May 2023

Most stereoscopic microscopes used for industrial component detection are large and have low detection efficiencies. The use of mobile phones as imaging systems (rather than conventional sensors) in industrial fields would make industrial testing more convenient. In this study, an external stereo microscope for mobile phones is designed. The proposed system can resolve details up to 0.01 mm with an 11 mm object field of view, −6.34× angular magnification, and quantitative 3D feature measurement. The combined system proposed in this paper is suitable for the microscopic observation of industrial components, with its low cost, high detection efficiency, and short installation steps.
Colinear focused laser differential interferometry and self-aligned focusing schlieren
Authors: Weisberger Joshua M. , Bathel Brett F.
Published: May 2023

A colinear focused laser differential interferometer (FLDI) and
self-aligned focusing schlieren (SAFS) system has been assembled and
tested in the laboratory, using a turbulent jet of compressed air
issuing from a small needle nozzle to provide a high frequency density
object. Measurements verified that the coupling of the SAFS system
onto the optical axis of the FLDI system had negligible influence on
the FLDI system’s data, including tests that assessed the influence of
the inclusion of dichroic mirrors, dichroic mirror reflection angle,
dichroic mirror positioning relative to the Wollaston prisms of the
FLDI system, and SAFS light propagation direction. A qualitative
comparison of the focusing ability of the two systems was made, and
FLDI power spectral density estimates and SAFS spectral proper
orthogonal decomposition were used for quantitative comparisons of the
acoustic frequency of the jet, with good agreement between the two.
The success of the system integration and resulting jet testing
demonstrates the utility of this colinear, simultaneous FLDI/SAFS
measurement system.
Graphdiyne-polymer composites for a hybrid bound-state pulsed fiber laser
Authors: Nie Liang , Zhao Yang , Guo Penglai , Wang Wei , Jin Zhiwen , Zhang Danni , Li Xiaohui , Guo Yixuan , Chai Tong , Liu Ruisheng
Published: May 2023

In this paper, the graphdiyne (GDY)-polymethyl methacrylate (PMMA) films are prepared by a spin-coating method. The PMMA films have the function of isolating GDY from air and protecting the GDY from mechanical damage. The nonlinear optical properties of GDY-PMMA films are probed experimentally. The nonlinear optical responses of GDY-PMMA films with a modulation depth of ∼4.94% and saturated magnetization of ∼0.3MW/cm2 are proved. When the GDY-PMMA films are applied to an erbium-doped hybrid passively mode-locked fiber laser (saturable absorber), the bound-state solitons, which are also called soliton molecules, can be obtained. The soliton molecule has a time separation of 13.31 ps, and the spectral modulation period of 0.58 nm. Along with the pump power increase, the separation of bound-state pulses becomes larger. When the pump power is fixed, stable bound solitons can be observed without any degeneration for more than 4.5 h. It is demonstrated that GDY-PMMA films have excellent nonlinear optical performance in a near-infrared regime, which we believe can be a novel type of photonics instrument and has a number of properties that are potentially promising in the ultrafast properties of laser.
Annotation-efficient learning for OCT segmentation
Authors: Zhang Haoran , Yang Jianlong , Zheng Ce , Zhao Shiqing , Zhang Aili
Published: May 2023

Deep learning has been successfully applied to OCT segmentation. However, for data from different manufacturers and imaging protocols, and for different regions of interest (ROIs), it requires laborious and time-consuming data annotation and training, which is undesirable in many scenarios, such as surgical navigation and multi-center clinical trials. Here we propose an annotation-efficient learning method for OCT segmentation that could significantly reduce annotation costs. Leveraging self-supervised generative learning, we train a Transformer-based model to learn the OCT imagery. Then we connect the trained Transformer-based encoder to a CNN-based decoder, to learn the dense pixel-wise prediction in OCT segmentation. These training phases use open-access data and thus incur no annotation costs, and the pre-trained model can be adapted to different data and ROIs without re-training. Based on the greedy approximation for the k-center problem, we also introduce an algorithm for the selective annotation of the target data. We verified our method on publicly-available and private OCT datasets. Compared to the widely-used U-Net model with 100% training data, our method only requires ∼10% of the data for achieving the same segmentation accuracy, and it speeds the training up to ∼3.5 times. Furthermore, our proposed method outperforms other potential strategies that could improve annotation efficiency. We think this emphasis on learning efficiency may help improve the intelligence and application penetration of OCT-based technologies.
Synchronization of silicon thermal free-carrier oscillators
Authors: Luiz Gustavo de O. , Rodrigues Caique C. , Alegre Thiago P. Mayer , Wiederhecker Gustavo S.
Published: May 2023

Recent exploration of collective phenomena in oscillator arrays has highlighted the potential to access a range of physical phenomena, from fundamental quantum many-body dynamics to the solution of practical optimization problems using photonic Ising machines. Spontaneous oscillations often arise in these oscillator arrays as an imbalance between gain and loss. Due to coupling between individual arrays, the spontaneous oscillation is constrained and leads to interesting collective behavior, such as synchronized oscillations in optomechanical oscillator arrays, ferromagnetic-like coupling in delay-coupled optical parametric oscillators, and binary phase states in coupled laser arrays. A key aspect of arrays is not only the coupling between the individuals but also their compliance toward neighbor stimuli. One self-sustaining photonic oscillator that can be readily implemented in a scalable foundry-based technology is based on the interaction of free carriers, temperature, and the optical field of a resonant silicon photonic microcavity. Here, we demonstrate that these silicon thermal free-carrier (FC) oscillators are extremely compliant to external excitation and can be synchronized up to their 16th harmonic using a weak seed. Exploring this unprecedented compliance to external stimuli, we also demonstrate robust synchronization between two thermal FC oscillators.
Wide field of view optical phased array with a high-directionality antenna
Authors: Wang Zheng , Yu Lei , Yang Yibo , Ma Pengfei , Cui Langlin , Luo Shuai , Ji Zhimin , Song Zhigang , Su Yanmei , Pan Jiaoqing , Wang Pengfei , Zhang Yejin
Published: May 2023

Light detection and ranging (LiDAR) is a widely utilized technology for extracting information from the outside world in fields such as automotive, robotics, and aerospace. Optical phased array (OPA) is a promising solution for LiDAR technology, although its application is limited by loss and alias-free steering range. In this paper, we propose a dual-layer antenna that achieves a peak directionality of over 92%, thereby mitigating antenna loss and enhancing power efficiency. Based on this antenna, we design and fabricate a 256-channel non-uniform OPA that achieves 150° alias-free steering.
Comprehensive measurement of the near-infrared refractive index of GaAs at cryogenic temperatures
Authors: Jiang Guo-qiu , Zhang Qi-hang , Zhao Jun-yi , Qiao Yu-kun , Ge Zhen-Xuan , Liu Run-ze , Chung Tung-Hsun , Lu Chao-yang , Huo Yong-heng
Published: May 2023

The refractive index is a critical parameter in optical and photonic
device design. However, due to the lack of available data, precise
designs of devices working in low temperatures are still frequently
limited. In this work, we have built a homemade spectroscopic
ellipsometer (SE) and measured the refractive index of GaAs at a
matrix of temperatures (4 K < T < 295 K) and photon wavelengths (700 nm < λ < 1000 nm) with a system error of ∼0.04. We
verified the credibility of the SE results by comparing them with
afore-reported data at room temperature and with higher precision
values measured by vertical GaAs cavity at cryogenic temperatures.
This work makes up for the lack of the near-infrared refractive index
of GaAs at cryogenic temperatures and provides accurate reference data
for semiconductor device design and fabrication.
High-power two-color plasma-based THz generation driven by a Tm-doped fiber laser
Authors: Buldt Joachim , Heuermann Tobias , Wang Ziyao , Gierschke Philipp , Lenski Mathias , Jauregui César , Limpert Jens
Published: May 2023

We report on the efficient generation of broadband THz radiation based on a two-color gas–plasma scheme. Broadband THz pulses covering the whole THz spectral region, from 0.1–35 THz, are generated. This is enabled by a high-power, ultra-fast, thulium-doped, fiber chirped pulse amplification (Tm:FCPA) system and a subsequent nonlinear pulse compression stage that uses a gas-filled capillary. The driving source delivers 40 fs pulses at a central wavelength of 1.9 μm with 1.2 mJ pulse energy and 101 kHz repetition rate. Owing to the long driving wavelength and the use of a gas-jet in the THz generation focus, the highest reported conversion efficiency for high-power THz sources (>20 mW) of 0.32% has been achieved. The high efficiency and average power of 380 mW of the broadband THz radiation make this an ideal source for nonlinear, tabletop THz science.
228 × 304 200-mW lidar based on a single-point global-depth d-ToF sensor and RGB-guided super-resolution neural network
Authors: Sun Miao , Wu Yifan , Cui Lebei , Yu Hengwei , Li Jie , Qian Jian , Wang Jier , Qiu Lei , Yin Chiang Patrick , Zhuo Shenglong
Published: May 2023

The cutting-edge imaging system exhibits low output resolution and high power consumption, presenting challenges for the RGB-D fusion algorithm. In practical scenarios, aligning the depth map resolution with the RGB image sensor is a crucial requirement. In this Letter, the software and hardware co-design is considered to implement a lidar system based on the monocular RGB 3D imaging algorithm. A 6.4 × 6.4-mm2 deep-learning accelerator (DLA) system-on-chip (SoC) manufactured in a 40-nm CMOS is incorporated with a 3.6-mm2 TX-RX integrated chip fabricated in a 180-nm CMOS to employ the customized single-pixel imaging neural network. In comparison to the RGB-only monocular depth estimation technique, the root mean square error is reduced from 0.48 m to 0.3 m on the evaluated dataset, and the output depth map resolution matches the RGB input.
Method for the refractive index of various tissues based on fluorescence microscopy
Authors: Fan Xiaoming , Tao Lele , Zhou Xiaoyu , He Xiao , Zhang Yu , Huang Haixin , Yang Jiale , Wang Simei , Ma Zhihui , Gensch Thomas , Huang Ruimin
Published: May 2023

Refractive index is an important optical constant that characterizes the interaction between light and specimen. A difference in refractive index between specimen and immersion medium introduces the imaging aberration and leads to a problem that the direct thickness measurement of a specimen by optical microscopy is not accurate. However, this aberration correction still requires the exact information of the refractive index of specimen and immersion medium. Herein, we propose an imaging strategy to estimate the refractive index for an unknown specimen. A simplified diffraction model is generated to obtain the relationship between axial scaling factor and refractive index. Then regular fluorescence microscopy is performed to measure the actual axial scaling factors of specimens from mouse muscle and tumor xenograft. Referring to our theoretical plot of axial scaling factor versus refractive index, the refractive index of tissue specimen is determined. For example, we obtain a mean refractive index (n) value of 1.36 for normal muscle tissues, and 1.41 for tumor xenografts. We demonstrate that this diffraction model-based estimation method is an alternative to the current techniques, improving the accurate measurement for refractive index of tissue specimen. The simple instrument requirement with an easy specimen preparation for this estimation method of refractive index may increase the image quality on tissue specimens with less aberration.
Universal visible emitters in nanoscale integrated photonics
Authors: Spektor G. , Carlson D. , Newman Z. , Skarda J. L. , Sapra N. , Su L. , Jammi S. , Ferdinand A. R. , Agrawal A. , Vučković J. , Papp S. B.
Published: May 2023

Visible wavelengths of light control the quantum matter of atoms and
molecules and are foundational for quantum technologies, including
computers, sensors, and clocks. The development of visible integrated
photonics opens the possibility for scalable circuits with complex
functionalities, advancing both science and technology frontiers. We
experimentally demonstrate an inverse design approach based on the
superposition of guided mode sources, allowing the generation and
complete control of free-space radiation directly from within a single
150 nm layer , showing low loss across visible and
near-infrared spectra. We generate diverging circularly polarized
beams at the challenging 461 nm wavelength that can be directly used
for magneto-optical traps of strontium atoms, constituting a
fundamental building block for a range of atomic-physics-based quantum
technologies. Our generated topological vortex beams and the potential
for spatially varying polarization emitters could open unexplored
light–matter interaction pathways, enabling a broad new
photonic–atomic paradigm. Our platform highlights the generalizability
of nanoscale devices for visible-laser emission and will be critical
for scaling quantum technologies.
Mutual repression between JNK/AP-1 and JAK/STAT stratifies senescent and proliferative cell behaviors during tissue regeneration
Authors: Jaiswal Janhvi , Egert Janine , Engesser Raphael , Peyrotón Andrea Armengol , Nogay Liyne , Weichselberger Vanessa , Crucianelli Carlo , Grass Isabelle , Kreutz Clemens , Timmer Jens , Classen Anne-Kathrin
Published: May 2023

Epithelial repair relies on the activation of stress signaling pathways to coordinate tissue repair. Their deregulation is implicated in chronic wound and cancer pathologies. Using TNF-α/Eiger-mediated inflammatory damage toDrosophilaimaginal discs, we investigate how spatial patterns of signaling pathways and repair behaviors arise. We find that Eiger expression, which drives JNK/AP-1 signaling, transiently arrests proliferation of cells in the wound center and is associated with activation of a senescence program. This includes production of the mitogenic ligands of the Upd family, which allows JNK/AP-1-signaling cells to act as paracrine organizers of regeneration. Surprisingly, JNK/AP-1 cell-autonomously suppress activation of Upd signaling viaPtp61Fand Socs36E, both negative regulators of JAK/STAT signaling. As mitogenic JAK/STAT signaling is suppressed in JNK/AP-1-signaling cells at the center of tissue damage, compensatory proliferation occurs by paracrine activation of JAK/STAT in the wound periphery. Mathematical modelling suggests that cell-autonomous mutual repression between JNK/AP-1 and JAK/STAT is at the core of a regulatory network essential to spatially separate JNK/AP-1 and JAK/STAT signaling into bistable spatial domains associated with distinct cellular tasks. Such spatial stratification is essential for proper tissue repair, as coactivation of JNK/AP-1 and JAK/STAT in the same cells creates conflicting signals for cell cycle progression, leading to excess apoptosis of senescently stalled JNK/AP-1-signaling cells that organize the spatial field. Finally, we demonstrate that bistable separation of JNK/AP-1 and JAK/STAT drives bistable separation of senescent signaling and proliferative behaviors not only upon tissue damage, but also inRasV12,scribtumors. Revealing this previously uncharacterized regulatory network between JNK/AP-1, JAK/STAT, and associated cell behaviors has important implications for our conceptual understanding of tissue repair, chronic wound pathologies, and tumor microenvironments.
Obstructive sleep apnea in a mouse model is associated with tissue-specific transcriptomic changes in circadian rhythmicity and mean 24-hour gene expression
Authors: Koritala Bala S. C. , Lee Yin Yeng , Gaspar Laetitia S. , Bhadri Shweta S. , Su Wen , Wu Gang , Francey Lauren J. , Ruben Marc D. , Gong Ming C. , Hogenesch John B. , Smith David F.
Published: May 2023

Intermittent hypoxia (IH) is a major clinical feature of obstructive sleep apnea (OSA). The mechanisms that become dysregulated after periods of exposure to IH are unclear, particularly in the early stages of disease. The circadian clock governs a wide array of biological functions and is intimately associated with stabilization of hypoxia-inducible factors (HIFs) under hypoxic conditions. In patients, IH occurs during the sleep phase of the 24-hour sleep–wake cycle, potentially affecting their circadian rhythms. Alterations in the circadian clock have the potential to accelerate pathological processes, including other comorbid conditions that can be associated with chronic, untreated OSA. We hypothesized that changes in the circadian clock would manifest differently in those organs and systems known to be impacted by OSA. Using an IH model to represent OSA, we evaluated circadian rhythmicity and mean 24-hour expression of the transcriptome in 6 different mouse tissues, including the liver, lung, kidney, muscle, heart, and cerebellum, after a 7-day exposure to IH. We found that transcriptomic changes within cardiopulmonary tissues were more affected by IH than other tissues. Also, IH exposure resulted in an overall increase in core body temperature. Our findings demonstrate a relationship between early exposure to IH and changes in specific physiological outcomes. This study provides insight into the early pathophysiological mechanisms associated with IH.
Amino acid sequence assignment from single molecule peptide sequencing data using a two-stage classifier
Authors: Smith Matthew Beauregard , Simpson Zack Booth , Marcotte Edward M.
Published: May 2023

We present a machine learning-based interpretive framework (whatprot) for analyzing single molecule protein sequencing data produced by fluorosequencing, a recently developed proteomics technology that determines sparse amino acid sequences for many individual peptide molecules in a highly parallelized fashion. Whatprot uses Hidden Markov Models (HMMs) to represent the states of each peptide undergoing the various chemical processes during fluorosequencing, and applies these in a Bayesian classifier, in combination with pre-filtering by a k-Nearest Neighbors (kNN) classifier trained on large volumes of simulated fluorosequencing data. We have found that by combining the HMM based Bayesian classifier with the kNN pre-filter, we are able to retain the benefits of both, achieving both tractable runtimes and acceptable precision and recall for identifying peptides and their parent proteins from complex mixtures, outperforming the capabilities of either classifier on its own. Whatprot’s hybrid kNN-HMM approach enables the efficient interpretation of fluorosequencing data using a full proteome reference database and should now also enable improved sequencing error rate estimates.
Predicting yield of individual field-grown rapeseed plants from rosette-stage leaf gene expression
Authors: De Meyer Sam , Cruz Daniel Felipe , De Swaef Tom , Lootens Peter , De Block Jolien , Bird Kevin , Sprenger Heike , Van de Voorde Michael , Hawinkel Stijn , Van Hautegem Tom , Inzé Dirk , Nelissen Hilde , Roldán-Ruiz Isabel , Maere Steven
Published: May 2023

In the plant sciences, results of laboratory studies often do not translate well to the field. To help close this lab-field gap, we developed a strategy for studying the wiring of plant traits directly in the field, based on molecular profiling and phenotyping of individual plants. Here, we use this single-plant omics strategy on winter-typeBrassica napus(rapeseed). We investigate to what extent early and late phenotypes of field-grown rapeseed plants can be predicted from their autumnal leaf gene expression, and find that autumnal leaf gene expression not only has substantial predictive power for autumnal leaf phenotypes but also for final yield phenotypes in spring. Many of the top predictor genes are linked to developmental processes known to occur in autumn in winter-typeB.napusaccessions, such as the juvenile-to-adult and vegetative-to-reproductive phase transitions, indicating that the yield potential of winter-typeB.napusis influenced by autumnal development. Our results show that single-plant omics can be used to identify genes and processes influencing crop yield in the field.
Soluble Vascular Adhesion Protein 1 (sVAP-1) as a biomarker for pregnancy complications: A pilot study
Authors: Danielli Marianna , Thomas Roisin C. , Gillies Clare L. , Lambert David G. , Khunti Kamlesh , Tan Bee Kang
Published: May 2023

Background

Vascular adhesion protein 1 (VAP-1) has been implicated in a wide range of clinical conditions. Moreover, serum levels are associated with disease prediction and progression in several clinical studies. There is a paucity of data on VAP-1 and pregnancy. Given the emerging role of VAP-1 in pregnancy, the aim of this study was to examine sVAP-1 as an early biomarker of pregnancy complications, especially hypertension during pregnancy. The objectives of the study are to associate sVAP-1 levels with other pregnancy complications, patient demographics and blood tests performed throughout pregnancy.

Methods

We conducted a pilot study in a cohort of pregnant women (gestational week lower than 20 at the time of recruitment) attending their first antenatal ultrasound scan at the Leicester Royal Infirmary (LRI, UK). Data were both prospectively generated (from blood sample analysis) and retrospectively collected (from hospital records).

Results

From July and October 2021, a total of 91 participants were enrolled. Using ELISA (enzyme-linked immunosorbent assay), we found reduced serum levels of sVAP-1 in pregnant women with either pregnancy induced hypertension (PIH) (310 ng/mL) or GDM (366.73 ng/mL) as compared to controls (427.44 ng/mL and 428.34 ng/mL, respectively). No significant difference was found between women with FGR compared to controls (424.32 ng/mL vs 424.52 ng/mL), and patients with any pregnancy complications compared to healthy pregnancies (421.28 ng/mL vs 428.34 ng/mL).

Conclusion

Further studies are needed to establish whether or not sVAP-1 might be considered as an early, non-invasive, and affordable biomarker to screen women who will develop PIH or GDM. Our data will aid sample size calculations for such larger studies.
Patients’ experience of undergoing maintenance hemodialysis. An interview study from Ethiopia
Authors: Gebrie Mignote Hailu , Asfaw Hussen Mekonnen , Bilchut Workagegnehu Hailu , Lindgren Helena , Wettergren Lena
Published: May 2023

Background

People with kidney failure require renal replacement therapy in the form of dialysis or a kidney transplant for survival. Many facets of their life, both within and outside the dialysis unit, are impacted by the management of this disease. It is important to comprehend the experiences of people undergoing hemodialysis in order to improve the care provided to them. Therefore, this study aimed to explore the experiences of patients undergoing maintenance hemodialysis in Ethiopia.

Methods

A qualitative descriptive study was conducted at two healthcare facilities in Ethiopia. Individual interviews with 15 participants (men and women aged 19–63), undergoing hemodialysis in Ethiopia, were analyzed using reflexive thematic analysis.

Results

The analysis resulted in five themes: Feeling grateful, Facing a restricted life, a Supportive environment, Dreaming of a transplant, and Leading a hassled life. The subthemes include Trust in treatment, Faith in God, Challenging fluid and dietary restrictions, Being too fatigued to socialize, Being stigmatized, Family and social support, Supportive healthcare, Lacking a donor and sponsor, COVID-19 as a barrier, Financial constraints, Inaccessibility to care and transport and Access line implantation. Despite being dependent on a machine and having to deal with food and fluid restrictions as well as financial challenges, participants were hopeful and dreamed of a transplant.

Conclusion

From the study’s participants, it was discovered that the experiences of people with kidney failure undergoing hemodialysis were generally, considerably negative narratives. Based on the results we recommend development of multidisciplinary teams to better meet patients’ physical, emotional, and social needs while undergoing hemodialysis. Such a team should also involve the patient’s family members when caring for patients on hemodialysis.