bluuebunny/crossref_metadata_2025 huggingface dataset:
DLR’s airborne support of ESA’s Aeolus mission - from pre-launch campaigns to mission performance validation
Authors: Witschas Benjamin , Lemmerz Christian , Lux Oliver , Rahm Stephan , Marksteiner Uwe , Geiß Alexander , Weiler Fabian , Reitebuch Oliver
Published: March 2023

In August 2018, the first-ever spaceborne wind lidar – Aeolus – was launched and has since then been providing global data of the horizontal wind field from the ground up to 30 km to improve numerical weather prediction. Aeolus is based on a single instrument called ALADIN (Atmospheric Laser Doppler Instrument), which comprises a single-frequency, ultraviolet solid-state laser in a master oscillator power amplifier configuration that emits nanosecond pulses into the atmosphere. High output energy and excellent frequency stability ensure a sufficient signal-to-noise ratio of the backscatter return needed for an accurate determination of the wind-induced Doppler frequency shift. To demonstrate the Aeolus measurement principle and to validate the corresponding wind data quality, the German Aerospace Center (DLR) started with airborne pre-launch validation activities already in 2007. After launch, these activities were extended by four campaigns over Europe, the North Atlantic region, and the tropics. In this talk, the challenges of the development and the operation of ALADIN are addressed and the successful accomplishment of the Aeolus mission is demonstrated using the results obtained from the post-launch validation campaigns.
Coherent Lidar for Airborne Wind Measurements with High-Percentage Tropospheric Coverage
Authors: Henderson Sammy , Kavaya Michael , Yu Jirong , Marketon John , Bedka Kris
Published: March 2023

A 2-micron coherent lidar has been developed with performance suitable for near continuous measurement of wind profiles from high-altitude aircraft to the Earth's surface under most atmospheric backscatter conditions.
1.4km Free Space Optical Communication Bit Error Rate Measurements over a 48 hour period at 10Gbit/s
Authors: Bradley C. , Ruff E.
Published: March 2023

Rapid, secure, high bandwidth communication is valuable for civilian uses such as last mile access, mesh networks, and disaster relief. Exciting Technology is developing low C-SWaP free space optical communication (FSOC) equipment that can be quickly put into operation by an unskilled user, can handle dynamic targets, and can communicate between one server node and multiple client nodes simultaneously. This paper describes BER experiments using an ET’s FSOC equipment over 48hrs and 1.4km.
Hermite-Gaussian Beams Classification based on 1D Speckle Information using 1D Convolutional Neural Network
Authors: Singh Purnesh , Kumar Vijay
Published: March 2023

Classification of Hermite-Gaussian modes using a randomly picked 1D cross-line array across the 2D speckle pattern of the respective modes is proposed. Less than one-by-thousandth of the image data is utilized for classification.
Optomechanical noise suppression with the optimal squeezing process
Authors: Wang Chang-Wei , Niu Wei , Zhang Yang , Cheng Jiong , Zhang Wen-Zhao
Published: March 2023

Quantum squeezing-assisted noise suppression is a promising field with wide applications. However, the limit of noise suppression induced by squeezing is still unknown. This paper discusses this issue by studying weak signal detection in an optomechanical system. By solving the system dynamics in the frequency domain, we analyze the output spectrum of the optical signal. The results show that the intensity of the noise depends on many factors, including the degree or direction of squeezing and the choice of the detection scheme. To measure the effectiveness of squeezing and to obtain the optimal squeezing value for a given set of parameters, we define an optimization factor. With the help of this definition, we find the optimal noise suppression scheme, which can only be achieved when the detection direction exactly matches the squeezing direction. The latter is not easy to adjust as it is susceptible to changes in dynamic evolution and sensitive to parameters. In addition, we find that the additional noise reaches a minimum when the cavity (mechanical) dissipation κ(γ) satisfies the relation κ = Nγ, which can be understood as the restrictive relationship between the two dissipation channels induced by the uncertainty relation. Furthermore, by taking into account the noise source of our system, we can realize high-level noise suppression without reducing the input signal, which means that the signal-to-noise ratio can be further improved.
Wave-optics-based image synthesis for super resolution reconstruction of a FZA lensless camera
Authors: Chen Xiao , Pan Xiuxi , Nakamura Tomoya , Takeyama Saori , Shimano Takeshi , Tajima Kazuyuki , Yamaguchi Masahiro
Published: March 2023

A Fresnel Zone Aperture (FZA) mask for a lensless camera, an ultra-thin and functional computational imaging system, is beneficial because the FZA pattern makes it easy to model the imaging process and reconstruct captured images through a simple and fast deconvolution. However, diffraction causes a mismatch between the forward model used in the reconstruction and the actual imaging process, which affects the recovered image’s resolution. This work theoretically analyzes the wave-optics imaging model of an FZA lensless camera and focuses on the zero points caused by diffraction in the frequency response. We propose a novel idea of image synthesis to compensate for the zero points through two different realizations based on the linear least-mean-square-error (LMSE) estimation. Results from computer simulation and optical experiments verify a nearly two-fold improvement in spatial resolution from the proposed methods compared with the conventional geometrical-optics-based method.
Compact single-polarization coupler based on a dual-hollow-core anti-resonant fiber
Authors: Jia Haoqiang , Wang Xin , Huang Bingsen , Xue Lu , Sheng Xinzhi , Lou Shuqin
Published: March 2023

A compact single-polarization (SP) coupler based on a dual-hollow-core anti-resonant fiber (DHC-ARF) is proposed. By introducing a pair of thick-wall tubes into a ten-tube single-ring hollow-core anti-resonant fiber, the core is separated into two cores to form the DHC-ARF. More importantly, by introducing the thick-wall tubes, dielectric modes in the thick wall are excited to inhibit the mode-coupling of secondary eigen-state of polarization (ESOP) between two cores while the mode-coupling of the primary ESOP can be enhanced, and thus the coupling length (Lc) of the secondary ESOP is greatly increased and that of primary ESOP is reduced to several millimeters. Simulation results show that the Lc of the secondary ESOP is up to 5549.26 mm and one of the primary ESOP is only 3.12 mm at 1550 nm through optimizing fiber structure parameters. By using a 1.53-mm-long DHC-ARF, a compact SP coupler can be implemented with a polarization extinction ratio (PER) less than - 20 dB within the wavelength range from 1547 nm to 1551.4 nm, and the lowest PER of - 64.12 dB is achieved at 1550 nm. Its coupling ratio (CR) is stable within 50 ± 2% in the wavelength range from 1547.6 nm to 1551.4 nm. The novel compact SP coupler provides a reference for developing HCF-based polarization-dependent components for use in the high-precision miniaturized resonant fiber optic gyroscope.
Monolithic silicon photonic 32x32 thin-CLOS AWGR for all-to-all interconnections
Authors: Fu Mingye , Liu Guangyao , Zhang Yichi , Proietti Roberto , Yoo S. J. Ben
Published: March 2023

This paper reports the design, fabrication, and experimental demonstration of a monolithic silicon photonic (SiPh) 32×32 Thin-CLOS arrayed waveguide grating router (AWGR) for scalable SiPh all-to-all interconnection fabrics. The 32×32 Thin-CLOS makes use of four 16-port silicon nitride AWGRs, which are compactly integrated and interconnected by a multi-layer waveguide routing method. The fabricated Thin-CLOS has 4 dB insertion loss, < −15 dB adjacent channel crosstalk, and < −20 dB non-adjacent channel crosstalk. System experiments operated on the 32×32 SiPh Thin-CLOS demonstrate error-free communication at 25 Gb/s.
Analogy of the interior Schwarzschild metric from transformation optics
Authors: Xiao Wen , Chen Huanyang
Published: March 2023

In this paper, we make an analogy of the interior Schwarzschild metric from transformation optics (we call the method transformation cosmology). It is shown that a simple refractive index profile is sufficient to capture the behavior of the metric to bend light. There is a critical value of the ratio of the radius of the massive star to the Schwarzschild radius, which is exactly related to the condition of collapsing into a black hole. We demonstrate the light bending effect for three cases from numerical simulations as well. Especially, we find that a point source at the photon sphere will form an image inside the star approximately, and the equivalent lens is like Maxwell’s fish-eye lens. This work will help us to explore the phenomena of massive stars with laboratory optical tools.
Low half-wave voltage polymeric electro-optic modulator using CLD-1/PMMA for electrocardiogram (ECG) signal acquisition
Authors: Li Hongqiang , Lin Zhilin , Zhang Lizhen , Cao Lu , Ren Feng , Meng Wentao , Wang Yingjie , Zhang Cheng , Chen Liying , Zhang Shanshan , Zhang Zanyun , Li Enbang , Daniel Prades Joan
Published: March 2023

Electro-optic (EO) modulators are typically made of inorganic materials such as lithium niobate; the replacement of these modulators with organic EO materials is a promising alternative due to their lower half-wave voltage (Vπ), ease of handling, and relatively low cost. We propose the design and fabrication of a push-pull polymer electro-optic modulator with voltage-length parameters (VπL) of 1.28 V·cm. The device uses a Mach–Zehnder structure and is made of a second-order nonlinear optical host-guest polymer composed of a CLD-1 chromophore and PMMA polymer. The experimental results show that the loss is 1.7 dB, Vπ drops to 1.6 V, and the modulation depth is 0.637 dB at 1550 nm. The results of a preliminary study show that the device is capable of efficiently detecting electrocardiogram (ECG) signals with performance on par with that of commercial ECG devices.
Ultraviolet communication with a large scattering angle via artificial agglomerate fog
Authors: Tang Jingyin , Ding Yifan , Lin Tianrui , Sun Lei , Pan Yuchen , Gong Chen , Xu Zhengyuan
Published: March 2023

Considering strong signal attenuation of the large-angle non-line-of-sight (NLOS) link achieved due to the ultraviolet (UV) scattering properties, we propose to increase the UV communication link gain under a large scattering angle via generating agglomerate fog within a certain range as a secondary light source. In this study, a channel model with locally strong scatterers from agglomerate fog is proposed based on Monte Carlo ray-tracing approaches. Mie theory is adopted to calculate the atmospheric channel parameters, to further evaluate the link gain of a channel under non-uniform atmosphere. The performance of scattering system in the presence of fog conditions depends on the relative positions of the light source to the fog and to the receiver. The link gain results reveal the transmission capabilities for different scattering channel geometries, and give the optimal spray point location within a 10 m communication range. We further establish a foggy NLOS system using an agglomerate fog generator to verify our research in the real environment. The results show that the received signal strength of the NLOS link can be effectively enhanced by constructing scatterers in the atmospheric channel, which significantly decreases the bit-error rate (BER).
Straight and curved distributed Bragg reflector design for compact WDM filters
Authors: Gebregiorgis Yonas , Chandran Sujith , Papadovasilakis Marios , Bian Yusheng , Rakowski Michal , Aboketaf Abdelsalam , Augur Rod , Viegas Jaime
Published: March 2023

Grating-assisted contra-directional couplers (CDCs) wavelength selective filters for wavelength division multiplexing (WDM) are designed and experimentally demonstrated. Two configuration setups are designed; a straight-distributed Bragg reflector (SDBR) and curved distributed Bragg reflector (CDBR). The devices are fabricated on a monolithic silicon photonics platform in a GlobalFoundries CMOS foundry. The sidelobe strength of the transmission spectrum is suppressed by controlling the energy exchange between the asymmetric waveguides of the CDC using grating and spacing apodization. The experimental characterization demonstrates a flat-top and low insertion loss (0.43 dB) spectrally stable performance (<0.7 nm spectral shift) across several different wafers. The devices have a compact footprint of only 130µm2/Ch (SDBR) and 3700µm2/Ch (CDBR).
QoS-aware secure transmission design for VLC with semi-grant-free NOMA scheme
Authors: Li Ganggang , Wang Ping , Zhou Binna , He Huimeng , Hao Weihan , Yang Ting
Published: March 2023

This work aims to enhance the physical layer security (PLS) of non-orthogonal multiple access (NOMA) aided indoor visible light communication (VLC) system with semi-grant-free (SGF) transmission scheme, in which a grant-free (GF) user shares the same resource block with a grant-based (GB) user whose quality of service (QoS) must be strictly guaranteed. Besides, the GF user is also provided with an acceptable QoS experience, which is closely aligned with the practical application. Both active and passive eavesdropping attacks are discussed in this work, where users’ random distributions are taken into account. Specifically, to maximize the secrecy rate of the GB user in the presence of an active eavesdropper, the optimal power allocation policy is obtained in exact closed-form and the user fairness is then assessed by Jain’s fairness index. Moreover, the secrecy outage performance of the GB user is analyzed in the presence of the passive eavesdropping attack. Both exact and asymptotic theoretical expressions for the secrecy outage probability (SOP) of the GB user are derived, respectively. Furthermore, the effective secrecy throughput (EST) is investigated on the basis of the derived SOP expression. Through simulations, it is found that the PLS of this VLC system can be significantly improved by the proposed optimal power allocation scheme. The radius of the protected zone, the outage target rate for the GF user, and the secrecy target rate for the GB user would have pronounced impacts on the PLS and user fairness performance of this SGF-NOMA assisted indoor VLC system. The maximum EST will increase with the increasing transmit power and it is hardly influenced by the target rate for the GF user. This work will benefit the design of indoor VLC system.
Monolithic high contrast grating on GaSb/AlAsSb based epitaxial structures for mid-infrared wavelength applications
Authors: Schade A. , Bader A. , Huber T. , Kuhn S. , Czyszanowski T. , Pfenning A. , Rygała M. , Smołka T. , Motyka M. , Sęk G. , Hartmann F. , Höfling S.
Published: March 2023

We demonstrate monolithic high contrast gratings (MHCG) based on GaSb/AlAs0.08Sb0.92 epitaxial structures with sub-wavelength gratings enabling high reflection of unpolarized mid-infrared radiation at the wavelength range from 2.5 to 5 µm. We study the reflectivity wavelength dependence of MHCGs with ridge widths ranging from 220 to 984 nm and fixed 2.6 µm grating period and demonstrate that peak reflectivity of above 0.7 can be shifted from 3.0 to 4.3 µm for ridge widths from 220 to 984 nm, respectively. Maximum reflectivity of up to 0.9 at 4 µm can be achieved. The experiments are in good agreement with numerical simulations, confirming high process flexibility in terms of peak reflectivity and wavelength selection. MHCGs have hitherto been regarded as mirrors enabling high reflection of selected light polarization. With this work, we show that thoughtfully designed MHCG yields high reflectivity for both orthogonal polarizations simultaneously. Our experiment demonstrates that MHCGs are promising candidates to replace conventional mirrors like distributed Bragg reflectors to realize resonator based optical and optoelectronic devices such as resonant cavity enhanced light emitting diodes and resonant cavity enhanced photodetectors in the mid-infrared spectral region, for which epitaxial growth of distributed Bragg reflectors is challenging.
Quantitative differential phase contrast imaging in an LED array microscope: errata
Authors: Tian Lei , Waller Laura
Published: March 2023

This errata corrects typos found in the derived transfer functions in [Opt. Express 23, 11394 (2015)10.1364/OE.23.011394].
Signal-to-idler energy conversion from 1.9 to 2.3 µm by transient stimulated Raman chirped-pulse amplification
Authors: Petrulenas Augustinas , Mackonis Paulius , Rodin Aleksej M.
Published: March 2023

The combination of optical parametric and transient stimulated Raman amplification of chirped pulses demonstrates a new approach for idler energy buildup in the short-wave (SW)IR range. Optical parametric chirped-pulse amplification (OPCPA) output pulses in the wavelength range from ∼1800 nm to ∼2000 nm for the signal and from ∼2100 nm to ∼2400 nm for the idler were used as pump and Stokes seed, respectively, in a stimulated Raman amplifier based on a KGd(WO4)2 crystal. Both OPCPA and its supercontinuum seed were pumped with ∼1.2-ps transform-limited pulses from a Yb:YAG chirped-pulse amplifier. The transient stimulated Raman chirped-pulse amplifier provides a 33% increase in idler energy with nearly transform-limited ∼53-fs pulses after compression.
Three-dimensional polarization of fields radiated by partially coherent electromagnetic cylindrical sources
Authors: Santarsiero M. , De Sande J. C. G. , Korotkova O. , Martínez-Herrero R. , Piquero G. , Gori F.
Published: March 2023

Partially coherent electromagnetic sources with cylindrical symmetry and infinite extent radiating outward are introduced. Their 3 × 3 cross-spectral density matrix is given through expansions of the field components in terms of basis functions related to the Hankel functions. The spectral density and the three-dimensional degree of polarization of such sources and the fields they radiate are examined. Several examples are presented and discussed. Among them, a class of cylindrical sources whose coherent vector modes coincide with the above basis functions is defined and studied.
Enhanced Light Emission of Germanium Light-Emitting-Diode on 150 mm Germanium-On-Insulator (GOI)
Authors: wu shaoteng , WANG Zhaozhen , Zhang Lin , Chen Qimiao , wen shuyu , Lee Kwang Hong , bao shuyu , FAN WJ , Tan Chuan Seng , Luo Jun-Wei
Published: March 2023

Germanium-on-insulator (GOI) has become a novel platform for Ge-based electronic and photonic applications. Discrete photonic devices such as waveguides, photodetectors, modulators, and optical pumping lasers have been successfully demonstrated on this platform. To realize electric injection emitting is highly desirable towards integrated photonics. In this work, we report for the first time the Ge p−i−n light-emitting-diodes (LEDs) on the GOI substrate. The high-quality Ge LED on a 150-mm diameter GOI substrate was fabricated via direct wafer bonding followed by ion implantations. As a tensile strain of 0.19% has been introduced during the GOI fabrication process resulting from thermal mismatch, the LED devices exhibit a dominant direct bandgap transition peak near 0.785 eV (~1,580nm) at room temperature. In sharp contrast to conventional III-V LEDs, we found that the electroluminescence/photoluminescence (EL/PL) spectra show enhanced intensities as raising the temperature from 300 to 450 K as a consequence of higher occupation of direct bandgap. The maximum enhancement in EL intensity is a factor of 140% near 1,635 nm due to the improved optical confinement offered by the bottom insulator layer. This work potentially broadens the GOI's functional variety for applications in near-infrared sensing, electronics, and photonics.
Propagation and focusing dependency of a laser beam with its aberration distribution: understanding of the halo induced disturbance.
Authors: RONDEPIERRE Alexandre , Espinos Driss Oumbarek , Zhidkov Alexei , Hosokai Tomonao
Published: March 2023

In various applications, it is necessary to understand laser field dynamics during its propagation, especially at the focal position including the dispersed energy surrounding the main pulse, that is called the halo effect. For instance, the properties of electron beams produced by Laser Wake Field Acceleration (LWFA) strongly depend on the laser energy distribution and its halo in the vicinity of the focus. Indeed, under certain condition this halo, or even its internal structures, can propagate and be self-focused independently of the main pulse in the plasma. This paper aims at providing sufficient tools to properly describe the behavior of a focused laser beam, including the halo. Consequently, an optical description regarding the source of this halo is provided. Therefore, a more accurate estimation of the input laser beam that should be used in simulations of high-power laser applications, may now be obtained. Finally, one may also find ways to positively manipulate the laser beam.
Using Fresnel diffraction theory, the propagation and focusing of an experimental high-power (sub-petawatt) aberrated beam is numerically calculated. The shape of the focused beam pattern within a few Rayleigh lengths is analysed as a function of main aberrations (up to the 14th term of Zernike Polynomials). Furthermore, at the focus position, spreading of the energy is compared to both the case of a perfect diffraction-limited Gaussian and a super-Gaussian beam.
G4mismatch: Deep neural networks to predict G-quadruplex propensity based on G4-seq data
Authors: Barshai Mira , Engel Barak , Haim Idan , Orenstein Yaron
Published: March 2023

G-quadruplexes are non-B-DNA structures that form in the genome facilitated by Hoogsteen bonds between guanines in single or multiple strands of DNA. The functions of G-quadruplexes are linked to various molecular and disease phenotypes, and thus researchers are interested in measuring G-quadruplex formation genome-wide. Experimentally measuring G-quadruplexes is a long and laborious process. Computational prediction of G-quadruplex propensity from a given DNA sequence is thus a long-standing challenge. Unfortunately, despite the availability of high-throughput datasets measuring G-quadruplex propensity in the form of mismatch scores, extant methods to predict G-quadruplex formation either rely on small datasets or are based on domain-knowledge rules. We developed G4mismatch, a novel algorithm to accurately and efficiently predict G-quadruplex propensity for any genomic sequence. G4mismatch is based on a convolutional neural network trained on almost 400 millions human genomic loci measured in a single G4-seq experiment. When tested on sequences from a held-out chromosome, G4mismatch, the first method to predict mismatch scores genome-wide, achieved a Pearson correlation of over 0.8. When benchmarked on independent datasets derived from various animal species, G4mismatch trained on human data predicted G-quadruplex propensity genome-wide with high accuracy (Pearson correlations greater than 0.7). Moreover, when tested in detecting G-quadruplexes genome-wide using the predicted mismatch scores, G4mismatch achieved superior performance compared to extant methods. Last, we demonstrate the ability to deduce the mechanism behind G-quadruplex formation by unique visualization of the principles learned by the model.
Benefit of stereoscopic volume rendering for the identification of pediatric pulmonary vein stenosis from CT angiography
Authors: Noga Michelle , Luan Jiali , Krishnaswamy Deepa , Morgan Brendan , Cockburn Ross , Punithakumar Kumaradevan
Published: March 2023

The use of three-dimensional (3D) technologies in medical practice is increasing; however, its use is largely untested. One 3D technology, stereoscopic volume-rendered 3D display, can improve depth perception. Pulmonary vein stenosis (PVS) is a rare cardiovascular pathology, often diagnosed by computed tomography (CT), where volume rendering may be useful. Depth cues may be lost when volume rendered CT is displayed on regular screens instead of 3D displays. The objective of this study was to determine whether the 3D stereoscopic display of volume-rendered CT improved perception compared to standard monoscopic display, as measured by PVS diagnosis. CT angiograms (CTAs) from 18 pediatric patients aged 3 weeks to 2 years were volume rendered and displayed with and without stereoscopic display. Patients had 0 to 4 pulmonary vein stenoses. Participants viewed the CTAs in 2 groups with half on monoscopic and half on stereoscopic display and the converse a minimum of 2 weeks later, and their diagnoses were recorded. A total of 24 study participants, comprised of experienced staff cardiologists, cardiovascular surgeons and radiologists, and their trainees viewed the CTAs and assessed the presence and location of PVS. Cases were classified as simple (2 or fewer lesions) or complex (3 or more lesions). Overall, there were fewer type 2 errors in diagnosis for stereoscopic display than standard display, an insignificant difference (p = 0.095). There was a significant decrease in type 2 errors for complex multiple lesion cases (≥3) vs simpler cases (p = 0.027) and improvement in localization of pulmonary veins (p = 0.011). Subjectively, 70% of participants stated that stereoscopy was helpful in the identification of PVS. The stereoscopic display did not result in significantly decreased errors in PVS diagnosis but was helpful for more complex cases.
Physical activity and functional disability among older adults in Ghana: The moderating role of multi-morbidity
Authors: Awuviry-Newton Kofi , Amponsah Mary , Amoah Dinah , Dintrans Pablo Villalobos , Afram Adjeiwa Akosua , Byles Julie , Mugumbate Jacob Rugare , Kowal Paul , Asiamah Nestor
Published: March 2023

Knowledge about how physical activity levels relate to functional disability is essential for health promotion and planning older adults’ care or rehabilitation. The risk of living with one or more chronic health conditions increases with increasing age in lower and higher income countries–many of which are associated with physical inactivity. We conducted a cross-sectional study to examine the moderating role of multimorbidity on physical activity and its measures on functional disability among older adults in Ghana. Data from WHO’s Study on global AGEing and adult health Ghana Wave 2 with a sample of 4,446 people aged 50+ years was used for this study. Functional disability was assessed using the 12-item WHO Disability Assessment Schedule 2.0. Three categories of physical activity levels were used: vigorous intensity, moderate intensity, and walking. Past month diagnosis by a doctor was used to assess the presence of a chronic condition, and the presence of two or more conditions was used to define multi-morbidity. Logistic regressions with a post hoc interactional tests were used to examine the associations. Overall, physical activity had a significant association with functional disability (OR = 0.25, 95%CI; 0.12, 0.32). A similar relationship was found for vigorous-intensity (OR = 0.19, 95%CI: 0.12, 0.29), moderate-intensity (OR = 0.19, 95%CI: 0.15, 0.25) and walking (OR = 0.41, 95%CI: 0.33, 0.51). Older adults living with one condition and physically active were 47% less likely to experience functional disability compared with the less active counterparts living with at least two chronic conditions. Among the three measures of physical activity, multimorbidity moderated the relationship between walking and functional disability. Future strategies for meeting the health and long-term care needs of older adults, particularly those living with only one chronic condition in Ghana should consider encouraging walking. Policies, financial assistance, family, and community level interventions aimed to promote and sustain physical activity among older adults should be a priority for stakeholders in Ghana.
Out-of-pocket expenditures and financial risks associated with treatment of vaccine-preventable diseases in Ethiopia: A cross-sectional costing analysis
Authors: Memirie Solomon Tessema , Tolla Mieraf Taddesse , Rumpler Eva , Sato Ryoko , Bolongaita Sarah , Tefera Yohannes Lakew , Tesfaye Latera , Tadesse Meseret Zelalem , Getnet Fentabil , Mengistu Tewodaj , Verguet Stéphane
Published: March 2023

Background

Vaccine-preventable diseases (VPDs) remain major causes of morbidity and mortality in low- and middle-income countries (LMICs). Universal access to vaccination, besides improved health outcomes, would substantially reduce VPD-related out-of-pocket (OOP) expenditures and associated financial risks. This paper aims to estimate the extent of OOP expenditures and the magnitude of the associated catastrophic health expenditures (CHEs) for selected VPDs in Ethiopia.

Methods and findings

We conducted a cross-sectional costing analysis, from the household (patient) perspective, of care-seeking for VPDs in children aged under 5 years for pneumonia, diarrhea, measles, and pertussis, and in children aged under 15 years for meningitis. Data on OOP direct medical and nonmedical expenditures (2021 USD) and household consumption expenditures were collected from 995 households (1 child per household) in 54 health facilities nationwide between May 1 and July 31, 2021. We used descriptive statistics to measure the main outcomes: magnitude of OOP expenditures, along with the associated CHE within households. Drivers of CHE were assessed using a logistic regression model. The mean OOP expenditures per disease episode for outpatient care for diarrhea, pneumonia, pertussis, and measles were $5·6 (95% confidence interval (CI): $4·3, 6·8), $7·8 ($5·3, 10·3), $9·0 ($6·4, 11·6), and $7·4 ($3·0, 11·9), respectively. The mean OOP expenditures were higher for inpatient care, ranging from $40·6 (95% CI: $12·9, 68·3) for severe measles to $101·7 ($88·5, 114·8) for meningitis. Direct medical expenditures, particularly drug and supply expenses, were the major cost drivers. Among those who sought inpatient care (345 households), about 13·3% suffered CHE, at a 10% threshold of annual consumption expenditures. The type of facility visited, receiving inpatient care, and wealth were significant predictors of CHE (p-value < 0·001) while adjusting for area of residence (urban/rural), diagnosis, age of respondent, and household family size. Limitations include inadequate number of measles and pertussis cases.

Conclusions

The OOP expenditures induced by VPDs are substantial in Ethiopia and disproportionately impact those with low income and those requiring inpatient care. Expanding equitable access to vaccines cannot be overemphasized, for both health and economic reasons. Such realization requires the government’s commitment toward increasing and sustaining vaccine financing in Ethiopia.
Evaluation of opportunities to implement community-wide mass drug administration for interrupting transmission of soil-transmitted helminths infections in India
Authors: Aruldas Kumudha , Dawson Kim , Saxena Malvika , Titus Angelin , Johnson Jabaselvi , Gwayi-Chore Marie-Claire , Muliyil Jayaprakash , Kang Gagandeep , Walson Judd L. , Khera Ajay , Ajjampur Sitara S. R. , Means Arianna Rubin
Published: March 2023

Background

The World Health Organization Neglected Tropical Disease (NTD) guidelines recommend control of soil transmitted helminth (STH)-associated morbidity with targeted deworming of preschool and school-aged children who are disproportionately affected by STH-associated morbidity. However, this strategy leaves many adults untreated and reinfection within communities perpetuates transmission even when mass drug administration (MDA) coverage of children is high. Evidence suggests that it may be possible to interrupt STH transmission by expanding MDA to a community-wide MDA (cMDA).

Methods

This multi-methods study of organizational readiness survey, key informant interviews, and program mapping, were conducted with government stakeholders in three Indian states, Goa, Sikkim, and Odisha, to assess readiness of the states for transitioning from school-based MDA to cMDA and identify opportunities to leverage existing infrastructure from other NTD programs like lymphatic filariasis (LF) for STH cMDA.

Principal findings

Overall, all three states indicated a highly favorable policy environment, effective leadership structure, adequate material resources, demonstrated technical capacity, and adequate community infrastructure needed to launch a STH cMDA program. The findings indicated a high-level of health system readiness to implement provided human resources and financial resources to deliver cMDA is strengthened. Areas with a significant overlap between LF and STH MDA platforms, particularly at the community-level, may be best primed for transitioning. Immunization, maternal child health, and non-communicable disease control programs were the other programs for possible integration of cMDA. States indicated having effective leadership structures in place at the state-level, however, engaging local leaders and community groups were considered crucial for successful implementation of cMDA. In-migration was a perceived challenge for estimating drug requirement and preventing possible stockouts.

Conclusions

Findings from this study are intended to proactively support government decision making, prioritization, and program planning across heterogenous implementation contexts in India to speed the translation of research findings into practice.

Clinical trial registration

NCT03014167; ClinicalTrials.gov.
Association between intraoperative end-tidal carbon dioxide and postoperative organ dysfunction in major abdominal surgery: A cohort study
Authors: Dong Li , Takeda Chikashi , Kamitani Tsukasa , Hamada Miho , Hirotsu Akiko , Yamamoto Yosuke , Mizota Toshiyuki
Published: March 2023

Background

Data on the effects of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative organ dysfunction are limited. Thus, this study was designed to investigate the relationship between the intraoperative EtCO2level and postoperative organ dysfunction in patients who underwent major abdominal surgery under general anesthesia.

Methods

We conducted a cohort study involving patients who underwent major abdominal surgery under general anesthesia at Kyoto University Hospital. We classified those with a mean EtCO2of less than 35 mmHg as low EtCO2. The time effect was determined as the minutes when the EtCO2value was below 35 mmHg, whereas the cumulative effect was evaluated by measuring the area below the 35-mmHg threshold. The outcome was postoperative organ dysfunction, defined as a composite of at least one organ dysfunction among acute renal injury, circulatory dysfunction, respiratory dysfunction, coagulation dysfunction, and liver dysfunction within 7 days after surgery.

Results

Of the 4,171 patients, 1,195 (28%) had low EtCO2, and 1,428 (34%) had postoperative organ dysfunction. An association was found between low EtCO2and increased postoperative organ dysfunction (adjusted risk ratio, 1.11; 95% confidence interval [CI], 1.03–1.20;p= 0.006). Additionally, long-term exposure to EtCO2values of less than 35 mmHg (≥224 min) was associated with postoperative organ dysfunction (adjusted risk ratio, 1.18; 95% CI, 1.06–1.32;p= 0.003) and low EtCO2severity (area under the threshold) (adjusted risk ratio, 1.13; 95% CI, 1.02–1.26;p= 0.018).

Conclusions

Intraoperative low EtCO2of below 35 mmHg was associated with increased postoperative organ dysfunction.
Detection of Hepatitis C virus RNA using a novel hybridization chain reaction method that competitively dampens cascade amplification
Authors: Zhang Chen , Qu Qingrong , Yao Yuming , Fan Xiaobo , Wu Guoqiu
Published: March 2023

The hybridization chain reaction (HCR) is widely used for biosensing. However, HCR does not provide the required sensitivity. In this study, we reported a method to improve the sensitivity of HCR by dampening the cascade amplification. First, we designed a biosensor based on HCR, and an initiator DNA was used to trigger the cascade amplification. Optimization of the reaction was then performed, and the results showed that the limit of detection (LOD) for the initiator DNA was about 2.5 nM. Second, we designed a series of inhibitory DNAs to dampen the HCR cascade amplification, and DNA dampeners (50 nM) were applied in the presence of the DNA initiator (50 nM). One of the DNA dampeners (D5) showed the best inhibitory efficiency of greater than 80%. This was further applied at concentrations ranging from 0 nM to 10 nM to prohibit the HCR amplification caused by a 2.5 nM initiator DNA (the limit of detection for this initiator DNA). The results showed that 0.156 nM of D5 could significantly inhibit the signal amplification (p<0.05). Additionally, the limit of detection for the dampener D5 was 16 times lower than that for the initiator DNA. Based on this detection method, we achieved a detection limit as low as 0.625 nM for HCV-RNAs. In summary, we developed a novel method with improved sensitivity to detect the target designed to prohibit the HCR cascade. Overall, this method could be used to qualitatively detect the presence of single-stranded DNA/RNA.
Evaluation of headstarting as a conservation tool to recover Blanding’s Turtles (Emydoidea blandingii) in a highly fragmented urban landscape
Authors: Wijewardena Tharusha , Keevil Matthew G. , Mandrak Nicholas E. , Lentini Andrew M. , Litzgus Jacqueline D.
Published: March 2023

Freshwater turtle populations are declining globally as a result of anthropogenic activities. Threats to turtles in urban areas are exacerbated by road mortality and subsidized predators, which can lead to catastrophic shifts in population size and structure. Headstarting is used as a conservation tool to supplement turtle populations that may otherwise face extirpation. A headstarting program began in 2012 to recover a functionally extinct population of Blanding’s Turtles (Emydoidea blandingii) 26in Rouge National Urban Park (RNUP), Ontario, Canada. The original population included five adults and one juvenile turtle. From 2014 to 2020, 270 headstarted turtles were released. The population has been monitored annually since 2014 using visual-encounter surveys, radio-telemetry, and live trapping (from 2018 onwards). We used mark-recapture and radio-telemetry data to quantify abundance, survival, and sex ratio of the headstarted turtle population. Using a Jolly-Seber model, we estimated abundance to be 183 turtles (20 turtles/ha) in 2020. Estimated survival of headstarted turtles approached 89%, except for turtles released in 2019 when survival was 43% as a result of a known mass mortality event at the study site. Pre- and post-release sex ratios were not significantly different (χ2 = 1.92; p = 0.16), but shifted from 1:1.5 to 1:1 male:female post-release. Given that the headstarted turtles have not yet reached sexual maturity, it is unclear whether headstarted turtles will reach adulthood and successfully reproduce to maintain a self-sustaining population. Thus, to evaluate the success of the headstarting program, long-term monitoring is required.
Flagellum-driven cargoes: Influence of cargo size and the flagellum-cargo attachment geometry
Authors: Bae Albert J. , Ahmad Raheel , Bodenschatz Eberhard , Pumir Alain , Gholami Azam
Published: March 2023

The beating of cilia and flagella, which relies on an efficient conversion of energy from ATP-hydrolysis into mechanical work, offers a promising way to propel synthetic cargoes. Recent experimental realizations of such micro-swimmers, in which micron-sized beads are propelled by isolated and demembranated flagella from the green algae Chlamydomonas reinhardtii (C. reinhardtii), revealed a variety of propulsion modes, depending in particular on the calcium concentration. Here, we investigate theoretically and numerically the propulsion of a bead as a function of the flagellar waveform and the attachment geometries between the bead and the flagellum. To this end, we take advantage of the low Reynolds number of the fluid flows generated by the micro-swimmer, which allows us to neglect fluid inertia. By describing the flagellar waveform as a superposition of a static component and a propagating wave, and using resistive-force theory, we show that the asymmetric sideways attachment of the flagellum to the bead makes a contribution to the rotational velocity of the micro-swimmer that is comparable to the contribution caused by the static component of the flagellar waveform. Remarkably, our analysis reveals the existence of a counter-intuitive propulsion regime in which an increase in the size of the cargo, and hence its drag, leads to an increase in some components of the velocity of the bead. Finally, we discuss the relevance of the uncovered mechanisms for the fabrication of synthetic, bio-actuated medical micro-robots for targeted drug delivery.
Troll story: The dark tetrad and online trolling revisited with a glance at humor
Authors: Volkmer Sara Alida , Gaube Susanne , Raue Martina , Lermer Eva
Published: March 2023

Internet trolling is considered a negative form of online interaction that can have detrimental effects on people’s well-being. This pre-registered, experimental study had three aims: first, to replicate the association between internet users’ online trolling behavior and the Dark Tetrad of personality (Machiavellianism, narcissism, psychopathy, and sadism) established in prior research; second, to investigate the effect of experiencing social exclusion on people’s motivation to engage in trolling behavior; and third, to explore the link between humor styles and trolling behavior. In this online study, participants were initially assessed on their personality, humor styles, and global trolling behavior. Next, respondents were randomly assigned to a social inclusion or exclusion condition. Thereafter, we measured participants’ immediate trolling motivation. Results drawn from 1,026 German-speaking participants indicate a clear correlation between global trolling and all facets of the Dark Tetrad as well as with aggressive and self-defeating humor styles. However, no significant relationship between experiencing exclusion/inclusion and trolling motivation emerged. Our quantile regression findings suggest that psychopathy and sadism scores have a significant positive effect on immediate trolling motivation after the experimental manipulation, whereas Machiavellianism and narcissism did not explain variation in trolling motivation. Moreover, being socially excluded had generally no effect on immediate trolling motivation, apart from participants with higher immediate trolling motivation, for whom the experience of social exclusion actually reduced trolling motivation. We show that not all facets of the Dark Tetrad are of equal importance for predicting immediate trolling motivation and that research should perhaps focus more on psychopathy and sadism. Moreover, our results emphasize the relevance of quantile regression in personality research and suggest that even psychopathy and sadism may not be suitable predictors for low levels of trolling behavior.
Regulation of inflammatory genes in decidual cells: Involvement of the bromodomain and extra-terminal family proteins
Authors: Ajgaonkar Sandeep , Hirst Jonathan J. , Norris Mary , Zakar Tamas
Published: March 2023

The decidua undergoes proinflammatory activation in late pregnancy, promoting labor. Bromodomain and Extra-Terminal (BET) family proteins interact with acetylated histones and may control gene expression in inflammation. Here, we assessed whether BETs are involved in inflammatory gene regulation in human decidual cells. We have treated primary cultures of decidual stromal cells (DSCs) from term pregnancies with endotoxin (LPS) and measured the expression of a panel of pro-and anti-inflammatory genes. BET involvement was assessed using the selective BET inhibitors (+)-JQ1 and I-BET-762 or the negative control compound (-)-JQ1. Histone 3 and -4 acetylation and BETs binding at the target gene promoters were determined to assess whether these processes are involved in the actions of LPS, BETs, and BET inhibitors. LPS increased the expression of the proinflammatory (PTGS2, IL6, CXCL8/IL8, TNF) and the anti-inflammatory (IL10, IDO1) genes of the panel. The constitutively expressed inflammatory genes (PTGS1, PTGES) were unaffected. The BET inhibitors, but not the control compound, reduced the basal and LPS-induced expression of PTGS1, PTGS2, IL6, CXCL8/IL8, IL10, and IDO1. TNF expression was not changed by BET inhibition. The dominant BETs were Bromodomain-containing protein -2 (BRD2) and -4L (BRD4L) in DSCs. LPS increased histone 4 acetylation at the CXCL8/IL8 and TNF promoters and histone 3 and -4 acetylation at the IDO1 promoter, while (+)-JQ1 abrogated histone acetylation at several promoters. Overall, histone acetylation and promoter binding of BETs showed no consistent relationship with gene expression across the gene panel and the treatments. BET proteins, predominantly BRD2 and BRD4L, control critical pro- and anti-inflammatory genes in DSCs. TNF induction exemplifies a BET-independent pathway. Changing histone acetylation at the promoters is not a general obligatory requirement for inflammatory gene expression in response to LPS. BETs likely act at chromatin loci separate from the examined promoters. BET inhibitors may block decidual activation at labor.
Phenotypic and Genotypic screening of fifty-two rice (Oryza sativa L.) genotypes for desirable cultivars against blast disease
Authors: B. Jeevan , Hosahatti Rajashekara , Koti Prasanna S. , Devappa Vinaykumar Hargi , Ngangkham Umakanta , Devanna Pramesh , Yadav Manoj Kumar , Mishra Krishna Kant , Aditya Jay Prakash , Boraiah Palanna Kaki , Gaber Ahmed , Hossain Akbar
Published: March 2023

Magnaporthe oryzae, the rice blast fungus, is one of the most dangerous rice pathogens, causing considerable crop losses around the world. In order to explore the rice blast-resistant sources, initially performed a large-scale screening of 277 rice accessions. In parallel with field evaluations, fifty-two rice accessions were genotyped for 25 major blast resistance genes utilizing functional/gene-based markers based on their reactivity against rice blast disease. According to the phenotypic examination, 29 (58%) and 22 (42%) entries were found to be highly resistant, 18 (36%) and 29 (57%) showed moderate resistance, and 05 (6%) and 01 (1%), respectively, were highly susceptible to leaf and neck blast. The genetic frequency of 25 major blast resistance genes ranged from 32 to 60%, with two genotypes having a maximum of 16R-genes each. The 52 rice accessions were divided into two groups based on cluster and population structure analysis. The highly resistant and moderately resistant accessions are divided into different groups using the principal coordinate analysis. According to the analysis of molecular variance, the maximum diversity was found within the population, while the minimum diversity was found between the populations. Two markers (RM5647 and K39512), which correspond to the blast-resistant genesPi36andPik, respectively, showed a significant association to the neck blast disease, whereas three markers (Pi2-i, Pita3, and k2167), which correspond to the blast-resistant genesPi2,Pita/Pita2, andPikm, respectively, showed a significant association to the leaf blast disease. The associated R-genes might be utilized in rice breeding programmes through marker-assisted breeding, and the identified resistant rice accessions could be used as prospective donors for the production of new resistant varieties in India and around the world.