bluuebunny/crossref_metadata_2025 huggingface dataset:
Divergence and self-healing of a discrete vortex formed by phase-locked lasers
Authors: Dev Vasu , Pal Vishwa
Published: October 2021

Optical beams carrying orbital angular momentum (optical vortices) are sought for various applications, such as optical communications, optical trapping and manipulation, and material processing. Many of these applications involve the propagation of such beams; therefore, the knowledge of various aspects such as beam size and beam divergence, as well as the effect of beam obstruction, is required. In this paper, we present a numerical study on the generation of high-power discrete vortices by phase locking a 1D ring array of lasers in a degenerate cavity that involves spatial Fourier filtering with a specifically designed amplitude mask. Further, we show that, for a given system size (number of lasers) and fixed distance between the nearest-neighbor lasers, the size of a discrete vortex and its divergence upon propagation do not depend on the orbital angular momentum (topological charge), as opposed to a continuous vortex (Laguerre–Gaussian/Bessel–Gauss beams). We also investigate the self-healing of a discrete vortex by obstructing it at the waist plane (

z
=
0

) as well as propagation plane (

z
>
0

), and we show that a discrete vortex possesses good self-healing abilities. The propagation of a truncated discrete vortex has enabled us to identify an unknown topological charge and the rotation dynamics of intensity in a discrete vortex.
Fast polarization control for optical frequency combs
Authors: Kageyama Taiki , Hasegawa Taro
Published: October 2021

Polarization of an optical frequency comb is electrically controlled using a waveguide electro-optic phase modulator (WG-EOM). Owing to the low operation voltage and wide electric bandwidth of the WG-EOM, fast polarization control is possible. It is found that birefringence of the WG-EOM and polarization-maintaining optical fibers causes polarization-dependent pulse separation, which makes polarization control of the optical frequency comb impossible. Therefore, compensation of the birefringence is required for polarization control. In the experiment, a delay line in free space is used for birefringence compensation, and pulse-to-pulse polarization control of an optical frequency comb (with a repetition rate of 100 MHz) is demonstrated.
Development of an all-day portable polarization lidar system based on the division-of-focal-plane scheme for atmospheric polarization measurements
Authors: Kong Zheng , Ma Teng , Zheng Kexin , Cheng Yuan , Gong Zhenfeng , Hua Dengxin , Mei Liang
Published: October 2021

A portable polarization lidar system based on the division-of-focal-plane scheme has been proposed for all-day accurate retrieval of the atmospheric depolarization ratio. The polarization lidar system has been designed as a T-shaped architecture consisting of a closed transmitter and a detachable large focal receiver, which is capable of outdoor unmanned measurements. The lidar system features low cost, low maintenance and short blind range (∼100 m) by utilizing a 450 nm multimode laser diode as the light source and a polarization image sensor with four polarized channels as the detector. Validation measurements have been carried out on a near horizontal path in ten consecutive days. The linear volume depolarization ratio (LVDR) as well as its measurement uncertainty has been theoretically and experimentally evaluated without employing additional optical components and sophisticated online calibrations. The offset angle can also be accurately retrieved (i.e., −0.06°) from the four-directional polarized lidar profiles with a standard deviation of ±0.02° during the whole measurement period, which contributes negligible influence on the retrieval of the LVDR. It has been found out that the uncertainty of the LVDR was mainly originated from the random noise, which was below 0.004 at nighttime and may reach up to 0.008 during daytime owing to the increasing sunlight background. The performance of the polarization lidar system has been further examined through atmospheric vertical measurements. The low-cost low-maintenance portable polarization lidar system, capable of detecting four-directional polarized lidar signals simultaneously, opens up many possibilities for all-day field measurements of dust, cloud, urban aerosol, oriented particles, etc.
Ultra-compact multimode waveguide bend with shallowly etched grooves
Authors: Gao Sai , Wang Hongwei , Yi XIaogen , Qiu Ciyuan
Published: October 2021

In this work, an ultra-sharp multimode waveguide bend (MWB) based on gradient shallowly etched grooves is proposed and demonstrated. With a bending radius of only 5.6 μm, our shallowly-etched-groove multimode waveguide bend (SMWB) can enable low excess loss and low-crosstalk propagation with the four lowest-order TE mode-channels, simultaneously. In the simulation, the excess losses of the proposed 90°- SMWB for TE0-TE3 are all below 0.46 dB and the inter-mode crosstalks are lower than −18 dB in 1500 nm-1600 nm. Furthermore, the measured results of the fabricated 90°- SMWB show that the excess losses for TE0-TE3 are less than 1 dB and the inter-mode crosstalks are all below −14 dB in 1510 nm-1580 nm. Such a proposed device thus provides a promising solution for ultra-compact MWBs in multimode silicon photonics.
Enhanced mid-infrared emission of Pr3+ ions in solids through a “3-for-1” excitation process – quantified
Authors: Merkle Larry D. , Fleischman Zackery , Brown Ei Ei , Allen Jan L. , Hommerich Uwe , Dubinskii Mark
Published: October 2021

Evidence is presented that a “three-for-one” process based on two cross-relaxations between Pr3+ ions efficiently populates the mid-infrared-emitting 3H5 manifold in a Pr3+-doped low-maximum-phonon-energy host. The concentration dependence of infrared fluorescence spectra and lifetimes of polycrystalline Pr:KPb2Cl5 initially excited to the 3F3,4 manifolds indicate that the 3500-5500-nm fluorescence becomes strongly favored over shorter-wavelength infrared emission bands in the higher-concentration sample. The strong concentration dependence of the 3F3 and 3H6 manifold lifetimes suggests that both of these decay by cross-relaxation processes, resulting in more than one ion excited to 3H5 for each ion initially excited to 3F3. Indeed, modeling and accounting for all possible decay paths indicate that, on average, about 2.3 ions are excited to 3H5 for each initially-excited ion. This confirms that the three-for-one excitation process must occur and contribute significantly to the total excitation efficiency. These results indicate that the two distinct cross-relaxation processes observed between Pr ions result in substantially higher excitation quantum efficiency, 230%, than any ever reported in rare-earth doped materials.
Spatial decoherence compensation algorithm for a target speckle field in heterodyne detection based on frequency analysis and time translation
Authors: Geng Jinni , Feng Zhejun , Cao Changqing , Feng Songmeng , Xu Xiangkai , Shang Yajie , Wu Zengyan , Yan Xu
Published: October 2021

The decoherence effect of a laser caused by a speckle field seriously restricts the development of heterodyne lidar. To address this problem, we proposed a spatial decoherence compensation algorithm, whose feasibility was proved by experiments with a system featuring simple structure and convenient operation. The results demonstrated that the speed of the proposed algorithm was several orders higher than that of other algorithms and the system SNR was increased by a maximum of 1464 times after the algorithm processing. The proposed algorithm can process the signal in real time and effectively, having great application potential in long-distance weak target detection.
Measuring particle size in ultra-low concentration suspensions by removing the number fluctuation contribution in dynamic light scattering
Authors: Wang Qin , Shen Jin , Wang Mengjie , Thomas John C. , Wang Yajing , Liu Wei , Li Xinqiang , Li Xiufeng
Published: October 2021

In ultra-low concentration suspensions, particle number fluctuations in the scattering volume add a long delay component to the intensity autocorrelation function (ACF) in dynamic light scattering (DLS) measurements. This gives a strong artifact peak in the particle size distribution (PSD) recovered. To improve the accuracy of DLS at ultra-low concentrations, we analyzed the different decay characteristics of particle Brownian motion and particle number fluctuation in the ACF. By differentiating the ACF we were able to identify and separate the number fluctuation term and then analyze the ACF to recover the PSD. The results for simulated DLS data at 151nm and 690nm diameters with average particle numbers of 6, 12, 24 and 48 in the scattering volume at four noise levels show that, compared with the usual DLS data processing method, inversion of the ACF after the separation of the number fluctuation term effectively eliminates the strong artifact peaks, and the relative errors of peak positions and distribution errors are significantly reduced. This was further verified with experimental results from samples of standard polystyrene spheres.
Determining femtosecond laser fluence for surface engineering of transparent conductive thin films by single shot irradiation
Authors: Ma Hao , Zhao Yuan’an , Shao Yuchen , Lin Xiangkun , Li Dawei , Cao Zhaoliang , Leng Yuxin , Shao Jianda
Published: October 2021

In recent years, there has been increasing interest in optoelectronic applications of transparent conductive oxide (TCO) thin-film-based materials and devices fabricated using patterning techniques. Meanwhile, femtosecond laser processing is a convenient method that further improves the performance of TCO-based functional devices and expands their application prospects. In this study, we proposed a simple and effective strategy to determine the fluences required for laser processing TCOs. We investigated the modification of an indium tin oxide (ITO) film induced by a femtosecond laser (45/150 fs, 800 nm) at different pulse fluences. The results reveal that the laser modification of ITO films is highly dependent on the irradiated pulse fluences. Several distinct types of final micro/nanostructures were observed and may be attributed to superficial amorphization, spallation ablation, stress-assisted delamination, boiling evaporation, and phase explosion. The final micro/nanostructures were studied in detail using optical microscopy, scanning electron microscopy, transmission electron microscopy and a surface profiler. At a lower fluence above the melting but below the ablation threshold, a laterally parabolic amorphous layer profiled with maximum thicknesses of several tens of nanometers was quantitatively attained. At a higher fluence, stress-assisted delamination and superheated liquid-induced micro-honeycomb structures emerged. Furthermore, the electron and lattice temperature evolutions were also obtained using a two-temperature model to prove the ablation mechanism and ascertain the micro/nanostructure formation principle. The predicted surface temperatures confirmed film amorphization without ablation below 0.23 J/cm2. These results reveal the interaction mechanism between femtosecond laser pulse and ITO film including the competition between the free electron heating of intraband transition and the multiphoton absorption of the interband transition, which promotes the potential applications for femtosecond laser processing TCO films and other wide-band-gap semiconductors such as photodetectors, solar cells, UV-light-emitting diodes, and flat-panel displays.
Measurement uncertainty evaluation procedures and applications for various types of multichannel rotating-element spectroscopic ellipsometers
Authors: Cho Yong Jai , Chegal Won
Published: October 2021

A universal measurement uncertainty evaluation procedure is required for different types of multichannel rotating-element spectroscopic ellipsometers (RE-SEs) used in modern semiconductor industry. Herein, an improved uncertainty evaluation procedure, based on the universal measurement model functions and implicit function theorem, is introduced for unknown optical parameters of a sample. In addition, we develop a measurement standard instrument that can solve the error problems related to the basic principles of the multichannel RE-SEs used in the industrial field and present an example of applying the proposed uncertainty evaluation method to this standard instrument. Accordingly, the measurement performance for several types of real-time RE-SEs can be quantitatively compared. It can also be used for standardization, instrumentation, and measurement optimization.
Frequency-based dispersion Lamb-dip spectroscopy in a high finesse optical cavity
Authors: Bielska Katarzyna , Cygan Agata , Konefał Magdalena , Kowzan Grzegorz , Zaborowski Mikołaj , Charczun Dominik , Wójtewicz Szymon , Wcisło Piotr , Masłowski Piotr , Ciuryło Roman , Lisak Daniel
Published: October 2021

Frequency-based cavity mode-dispersion spectroscopy (CMDS), previously applied for Doppler-limited molecular spectroscopy, is now employed for the first time for saturation spectroscopy. Comparison with two intensity-based, cavity-enhanced absorption spectroscopy techniques, i.e. cavity mode-width spectroscopy (CMWS) and the well-established cavity ring-down spectroscopy (CRDS), shows the predominance of the CMDS. The method enables measurements in broader pressure range and shows high immunity of the Lamb dip position to the incomplete model of saturated cavity mode shape. Frequencies of transitions from the second overtone of CO are determined with standard uncertainty below 500 Hz which corresponds to relative uncertainty below 3 × 10−12. The pressure shift of the Lamb dips, which has not been detected for these transitions in available literature data, is observed.
Broadband anomalous reflective metasurface for complementary conversion of arbitrary incident polarization angles
Authors: Sun Yuhang , Liu Yumin , Wu Tiesheng , Wu Jun , Wang Yu , Li Jing , Ye Han
Published: October 2021

The abrupt phase changes at the interface can modulate the polarization and wavefront of electromagnetic waves, which is the physical mechanism of the plasmonic metasurfaces. Conventional polarization converters are difficult to obtain pure polarized light, and most of the anomalously reflecting metasurfaces are limited by the specific angle of incident polarization. Here, we present a high-efficient polarization-independent metasurface for broadband polarization conversion and anomalous reflection when a plane wave with an arbitrary polarization angle is incident vertically. We vary the dimensions of the polarization conversion unit cells and arrange them periodically to cover the full 2π phase range of cross-polarized light in two orthogonal directions. The simulation results show that the pure anomalous cross-polarization efficiency is over 80% over a wavelength range from 1400nm to 1800nm. In particular, the metasurface can realize the complementary conversion of polarization angle for incident light at any polarization angle, and deflect it to a specific angle. Our design provides strategies for miniaturization and integration of polarization conversion devices and systems.
Single-shot chirped pulse BOTDA for static and dynamic strain sensing
Authors: Wang Yuan , Chen Liang , Bao Xiaoyi
Published: October 2021

Driven by the strong need for distributed high-frequency dynamic strain sensing, ultra-fast Brillouin optical time-domain analysis is rapidly becoming a vital technique. Thus, in this Letter, we propose and demonstrate a novel method by using a chirped pulse as a pump signal to extract the relative Brillouin frequency shift (BFS) changes through the real-time delays between adjacent Brillouin traces; this enables static and dynamic strain measurement without time-consuming frequency sweeping process. Benefiting from single-shot measurement based on Brillouin traces, the system has a high acquisition rate that is only limited by the sensor length without averaging, and is immune to the polarization fading problem, thanks to electrical delay time measurement. The pump source is a 1 MHz linewidth laser without a phase-locking loop; the laser frequency drifting noise could be compensated by the signal from the non-disturbed fiber section. In the experiments, BFS measurement resolution of 0.42 MHz with 4.5 m spatial resolution is demonstrated over a 5 km non-uniform fiber.
Holographic and speckle encryption using deep learning
Authors: Wang Xiaogang , Wang Wenqi , Wei Haoyu , Xu Bijun , Dai Chaoqing
Published: October 2021

Vulnerability analysis of optical encryption schemes using deep learning (DL) has recently become of interest to many researchers. However, very few works have paid attention to the design of optical encryption systems using DL. Here we report on the combination of the holographic method and DL technique for optical encryption, wherein a secret image is encrypted into a synthetic phase computer-generated hologram (CGH) by using a hybrid non-iterative procedure. In order to increase the level of security, the use of the steganographic technique is considered in our proposed method. A cover image can be directly diffracted by the synthetic CGH and be observed visually. The speckle pattern diffracted by the CGH, which is decrypted from the synthetic CGH, is the only input to a pre-trained network model. We experimentally build and test the encryption system. A dense convolutional neural network (DenseNet) was trained to estimate the relationship between the secret images and noise-like diffraction patterns that were recorded optically. The results demonstrate that the network can quickly output the primary secret images with high visual quality as expected, which is impossible to achieve with traditional decryption algorithms.
Cascade Er:YAG pulsed lasers at room temperature
Authors: Wang Sibo , Qu Bo , Tian Ye , Zhu Zhanda , Hui Yongling , Lei Hong , Li Qiang
Published: October 2021

Cascaded mid-infrared (MIR) pulsed laser output in Er:YAG crystals at room temperature is achieved experimentally. The existence of a cascade at room temperature in Er:YAG crystals is confirmed. Furthermore, the effect of the cascade on MIR laser performance is studied. With the assistance of the cascade, the thresholds are reduced by 13.3% and 12.5%, and the slope efficiencies are increased by 3.2% and 12.3% compared to a non-cascade configuration in 10 and 15 at.% Er:YAG, respectively. The excited-state absorption is considered to be the mechanism responsible for the laser performance optimization. This Letter should be helpful for the improvement of erbium-doped 3 µm laser output energy.
Transient-mode photothermal optical coherence tomography
Authors: Salimi Mohammad Hossein , Villiger Martin , Tabatabaei Nima
Published: October 2021

Photothermal optical coherence tomography (PT-OCT) is an emerging extension of OCT, which forms images based on both scattering and absorption of light. The speed of PT-OCT, however, has been limited by the necessity for lock-in detection with extensive temporal sampling of the sample’s PT response. Here, we demonstrate transient-mode PT-OCT (TM-PT-OCT), which increases the effective A-line rate by orders of magnitude from 10–100 Hz to 1.5–7.5 kHz, by interrogating the sample’s transient thermal response to a single diode laser pulse. Functional imaging of moving samples with TM-PT-OCT at video rate is also presented. This significant improvement in imaging speed is expected to open the door for downstream integration of PT-OCT in clinical systems for in vivo imaging.
Operational response simulation tool for epidemics within refugee and IDP settlements: A scenario-based case study of the Cox’s Bazar settlement
Authors: Aylett-Bullock Joseph , Cuesta-Lazaro Carolina , Quera-Bofarull Arnau , Katta Anjali , Hoffmann Pham Katherine , Hoover Benjamin , Strobelt Hendrik , Moreno Jimenez Rebeca , Sedgewick Aidan , Samir Evers Egmond , Kennedy David , Harlass Sandra , Gidraf Kahindo Maina Allen , Hussien Ahmad , Luengo-Oroz Miguel
Published: October 2021

The spread of infectious diseases such as COVID-19 presents many challenges to healthcare systems and infrastructures across the world, exacerbating inequalities and leaving the world’s most vulnerable populations most affected. Given their density and available infrastructure, refugee and internally displaced person (IDP) settlements can be particularly susceptible to disease spread. In this paper we present an agent-based modeling approach to simulating the spread of disease in refugee and IDP settlements under various non-pharmaceutical intervention strategies. The model, based on theJuneopen-source framework, is informed by data on geography, demographics, comorbidities, physical infrastructure and other parameters obtained from real-world observations and previous literature. The development and testing of this approach focuses on the Cox’s Bazar refugee settlement in Bangladesh, although our model is designed to be generalizable to other informal settings. Our findings suggest the encouraging self-isolation at home of mild to severe symptomatic patients, as opposed to the isolation of all positive cases in purpose-built isolation and treatment centers, does not increase the risk of secondary infection meaning the centers can be used to provide hospital support to the most intense cases of COVID-19. Secondly we find that mask wearing in all indoor communal areas can be effective at dampening viral spread, even with low mask efficacy and compliance rates. Finally, we model the effects of reopening learning centers in the settlement under various mitigation strategies. For example, a combination of mask wearing in the classroom, halving attendance regularity to enable physical distancing, and better ventilation can almost completely mitigate the increased risk of infection which keeping the learning centers open may cause. These modeling efforts are being incorporated into decision making processes to inform future planning, and further exercises should be carried out in similar geographies to help protect those most vulnerable.
Environmental factors and hygiene behaviors associated with facial cleanliness and trachoma in Kongwa, Tanzania
Authors: Chen Xinyi , Munoz Beatriz , Wolle Meraf A. , Woods Geordie , Odonkor Michelle , Naufal Fahd , Mkocha Harran , West Sheila K.
Published: October 2021

Background

Having a clean face is protective against trachoma. In the past, long distances to water were associated with unclean faces and increased trachoma. Other environmental factors have not been extensively explored. We need improved clarity on the environmental factors associated with facial cleanliness and trachoma prevalence, especially when the disease burden is low.

Methodology/Principle findings

A cross-sectional survey focusing on household environments was conducted in all 92 villages in Kongwa, Tanzania, in a random selection of 1798 households. Children aged 0–5 years in these households were examined for facial cleanliness. In each of the 50 randomly-selected villages, 50 children aged 1–9 years were randomly selected and examined for trachoma. In a multivariate model adjusting for child age, we found that children were more likely to have clean faces if the house had a clean yard (OR 1.62, 95% CI 1.37–1.91), an improved latrine (OR 1.11, 95% CI 1.01–1.22), and greater water storage capacity (OR 1.02, 95% CI 1.00–1.04), and if there were clothes washed and drying around the house (OR 1.30, 95% CI 1.09–1.54). However, measures of crowding, wealth, time spent on obtaining water, or the availability of piped water was not associated with clean faces. Using a cleanliness index (clean yard, improved latrine, washing clothes, ≥1 child in the household having a clean face), the community prevalence of trachoma decreased with an increase in the average value of the index (OR 2.28, 95% CI 1.17–4.80).

Conclusions/Significance

Access to water is no longer a significant limiting factor in children’s facial cleanliness in Kongwa. Instead, water storage capacity and the way that water is utilized are more important in facial cleanliness. A household cleanliness index with a holistic measure of household environment is associated with reduced community prevalence of trachoma.
Leprosy in children in Cuba: Epidemiological and clinical description of 50 cases from 2012–2019
Authors: Rumbaut Castillo Raisa , Hurtado Gascón Laura C. , Ruiz-Fuentes Jenny Laura , Pastrana Fundora Fernanda M. , Ramírez Albajés César R. , Henao-Martínez Andres F. , Franco-Paredes Carlos , Escobedo Ángel Arturo
Published: October 2021

Introduction

In 1993, Cuba achieved leprosy elimination according to the World Health Organization’s (WHO) indicator of less than one case per 10,000 population. Despite this achievement, detection of new cases occurs every year among all age groups including children. Detection of new cases in children reveals persistent transmission of the infection.

Objective

To describe the clinical and epidemiological features of leprosy in individuals younger than 15 years (childhood leprosy) reported to the Cuban National Leprosy Control Program (NLCP) between 2012 and 2019.

Methods

We conducted a retrospective descriptive study between 2012 and 2019 to assess the clinical and epidemiologic features of individuals under the age of 15 years with a confirmed diagnosis of leprosy reported to the NLCP. We reviewed the NLCP database and collected data to better define the total number of cases of leprosy in adults, children (younger than 15 years). We assessed socio-demographic variables (age, gender, and province of residence) as well as variables of clinical interest including operational classification and staging at diagnosis, bacillary index, grade of disability by WHO staging. Additionally, we evaluated epidemiological variables including passive versus active surveillance of cases, contact investigation focusing specifically in household transmission, and the degree of kinship as well as standing of the child within the focus of transmission when there were additional cases.

Results

We identified fifty children during the study period corresponding to 3% of the overall cases of leprosy comprising all age groups in Cuba. In the age group younger than 15 years, the majorities of cases was from the Granma province and most were between the ages of 10 and 14 years. Clinically, multibacillary/lepromatous forms were the most common type identified with positive bacillary index. The majority of children diagnosed with leprosy during our study period had a history of a relative with a confirmed diagnosis of leprosy.

Conclusions

Detection of cases of leprosy in individuals younger than 15 years of age in Cuba demonstrates ongoing transmission of M. leprae in specific geographic hotspots. Its frequency in the early adolescence, the predominant clinical forms, and the mode of detection associated with sources of suspected familiar infection demonstrated that there is a need for further efforts by the NLCP to conduct active surveillance activities among affected communities to identify cases of leprosy earlier with the goal of preventing further household and community transmission.
Characterizing bracken fern phenological cycle using time series data derived from Sentinel-2 satellite sensor
Authors: Matongera Trylee Nyasha , Mutanga Onisimo , Sibanda Mbulisi
Published: October 2021

Bracken fern is an invasive plant that has caused serious disturbances in many ecosystems due to its ability to encroach into new areas swiftly. Adequate knowledge of the phenological cycle of bracken fern is required to serve as an important tool in formulating management plans to control the spread of the fern. This study aimed to characterize the phenological cycle of bracken fern using NDVI and EVI2 time series data derived from Sentinel-2 sensor. The TIMESAT program was used for removing low quality data values, model fitting and for extracting bracken fern phenological metrics. The Sentinel-2 satellite-derived phenological metrics were compared with the corresponding bracken fern phenological events observed on the ground. Findings from our study revealed that bracken fern phenological metrics estimated from satellite data were in close agreement with ground observed phenological events with R2 values ranging from 0.53–0.85 (p < 0.05). Although they are comparable, our study shows that NDVI and EVI2 differ in their ability to track the phenological cycle of bracken fern. Overall, EVI2 performed better in estimating bracken fern phenological metrics as it related more to ground observed phenological events compared to NDVI. The key phenological metrics extracted in this study are critical for improving the precision in the controlling of the spread of bracken fern as well as in implementing active protection strategies against the invasion of highly susceptible rangelands.
Competitiveness of Xinjiang’s mutton industry based on diamond model
Authors: Dawut Ablat , Tian Yingjie
Published: October 2021

In recent years, Xinjiang mutton production has experienced a growth trend; however, it cannot meet the new consumer demand. Based on Michael Porter’s “diamond model,” this study presents a case study on the Xinjiang mutton industry in China and establishes an index system for the competitiveness of the industry. The competitiveness of the mutton industry is analyzed quantitatively via correlation analysis and principal component analysis by investigating the relevant data of 10 Chinese provinces topping in mutton production. On account of the related elements of the diamond model, a qualitative analysis is also performed. The quantitative analysis shows that among the 10 provinces (regions) topping in mutton production in China, Inner Mongolia wins in competitiveness, followed by Xinjiang, and Henan ranks at the bottom. The qualitative analysis shows that the Xinjiang mutton industry is inferior in three main factors compared to its competitors, and these are the production factors related to and supporting the industries and the enterprise strategies. Xinjiang performs moderately in terms of the auxiliary government factors. However, Xinjiang is in an advantageous position with respect to the main factors of demand conditions and auxiliary elements of opportunities. Given the existing problems, this study discusses the main reasons for the lack of competitiveness of the Xinjiang mutton industry. It also puts forward some strategic suggestions to enhance the competitiveness of the Xinjiang mutton industry based on the six elements of diamond model.
The prognostic value of peripheral total and differential leukocyte count in renal progression: A community-based study
Authors: Yen Chiung-Hui , Wu I-Wen , Lee Chin-Chan , Hsu Kuang-Hung , Sun Chiao-Yin , Chen Chun-Yu , Pan Heng-Chih , Hsu Heng Jung
Published: October 2021

Background

Systemic inflammation is related to chronic kidney disease (CKD) patients. Elevated peripheral leukocyte count may be a herald of increased systemic inflammation and subclinical disease. Inflammation plays an important role in renal progression. The pattern of total and differential leukocyte count in CKD is not well understood. Besides, the association between total and differential leukocyte count and renal progression is still uncertain.

Methods

We conducted a community-based cohort study with a follow-up period of two years to evaluate the total and differential leukocyte counts and renal progression association.

Results

In our study population from the community with a total number of 2128, we found 15.7% (335/2128) CKD patients with a mean estimated glomerular filtration rate (eGFR) around 96 ± 26 ml/min/1.73 m2. The peripheral total leukocyte count and also differential leukocyte count were significantly negatively correlated with eGFR. A total of 56 patients (3%) experienced a rapid progression of the kidney with the definition of eGFR reduction changes of 30% or greater within two years. Univariate analysis indicated that rapid renal progression was significantly associated with male gender, co-morbidity of diabetes mellitus (DM), higher uric acid levels, higher peripheral neutrophil, monocyte, and eosinophil counts. However, only the peripheral neutrophil count was positively and independently associated with rapid renal progression after multivariate analysis. The ROC curve analysis found that the optimal cutoff value of peripheral neutrophil count for rapid progression was 2760/ mm3, with an area under the curve of 0.813.

Conclusion

Hyperinflammation with higher peripheral total and differential leukocyte count was noted in CKD patients. The peripheral neutrophil count was the only independent factor significantly associated with rapid renal progression. The optimal cutoff point of the peripheral neutrophil count with 2760/mm3 is useful for determining the high-risk population for rapid renal progression with a satisfying sensitivity and specificity.
Public perceptions of non-adherence to pandemic protection measures by self and others: A study of COVID-19 in the United Kingdom
Authors: Williams Simon N. , Armitage Christopher J. , Tampe Tova , Dienes Kimberly A.
Published: October 2021

Background

Novel viral pandemics present significant challenges to global public health. Non-pharmaceutical interventions (e.g. social distancing) are an important means through which to control the transmission of such viruses. One of the key factors determining the effectiveness of such measures is the level of public adherence to them. Research to date has focused on quantitative exploration of adherence and non-adherence, with a relative lack of qualitative exploration of the reasons for non-adherence.

Objective

To explore participants’ perceptions of non-adherence to COVID-19 policy measures by self and others in the UK, focusing on perceived reasons for non-adherence.

Methods

Qualitative study comprising 12 focus groups conducted via video-conferencing between 25th September and 13th November 2020. Participants were 51 UK residents aged 18 and above, reflecting a range of ages, genders and race/ethnicities. Data were analysed using a thematic approach.

Results

Participants reported seeing an increase in non-adherence in others over the course of the pandemic. Reports of non-adherence in self were lower than reports of non-adherence in others. Analysis revealed six main themes related to participants’ reported reasons for non-adherence in self and others: (1) ‘Alert fatigue’ (where people find it difficult to follow, or switch off from, information about frequently changing rules or advice) (2) Inconsistent rules (3) Lack of trust in government (4) Learned Helplessness (5) Resistance and rebelliousness (6)The impact of vaccines on risk perception. Participants perceived a number of systemic failures (e.g. unclear policy, untrustworthy policymakers) to strongly contribute to two forms non-adherence—violations and errors.

Conclusion

Findings suggest that latent and systemic failures—in the form of policy decisions that are commonly experienced as too changeable, inconsistent and confusing, and policy makers that are commonly perceived as untrustworthy–may play a significant role in creating the conditions that enable or encourage non-adherence.
Clinical management and outcome differences between first and second waves among COVID-19 hospitalized patients: A regional prospective observational cohort
Authors: Zuil María , Benítez Iván D. , Cabo-Gambín Ramón , Manzano Senra Carlos , Moncusí-Moix Anna , Gort-Paniello Clara , de Gonzalo-Calvo David , Molinero Marta , Vengoechea Aragoncillo Jose Javier , Comella Thais , de Batlle Jordi , Torres Gerard , Torres Antoni , Barbé Ferrán , González Jessica
Published: October 2021

The objective was to describe the clinical characteristics and outcomes of hospitalized COVID-19 patients during the two different epidemic periods. Prospective, observational, cohort study of hospitalized COVID-19. A total of 421 consecutive patients were included, 188 during the first period (March-May 2020) and 233 in the second wave (July-December 2020). Clinical, epidemiological, prognostic and therapeutic data were compared. Patients of the first outbreak were older and more comorbid, presented worse PaO2/FiO2 ratio and an increased creatinine and D-dimer levels at hospital admission. The hospital stay was shorter (14.5[8;29] vs 8[6;14] days, p<0.001), ICU admissions (31.9% vs 13.3%, p<0.001) and the number of patients who required mechanical ventilation (OR = 0.12 [0.05–10.26]; p<0.001) were reduced. There were no significant differences in hospital and 30-day after discharge mortality (adjusted HR = 1.56; p = 0.1056) or hospital readmissions. New treatments and clinical strategies appear to improve hospital length, ICU admissions and the requirement for mechanical ventilation. However, we did not observe differences in mortality or readmissions.
Messages that increase COVID-19 vaccine acceptance: Evidence from online experiments in six Latin American countries
Authors: Argote Tironi Pablo , Barham Elena , Zuckerman Daly Sarah , Gerez Julian E. , Marshall John , Pocasangre Oscar
Published: October 2021

As safe and effective vaccines become widely available, attaining herd immunity and limiting the spread of COVID-19 will depend on individuals choosing to vaccinate—and doing so quickly enough to outpace mutations. Using online surveys conducted across six Latin American countries in January 2021, we experimentally assess messages designed to counteract informational deficiencies and collective action problems that may drive hesitancy. We first find that basic vaccine information persuades around 8% of hesitant individuals to become willing to vaccinate, reduces intended wait to vaccinate by 0.4 months, and increases willingness to encourage others to vaccinate. Rather than facilitating free riding, learning, or social conformity, additional information about others’ behavior increases vaccine acceptance when respondents expect herd immunity will be achieved. Finally, priming the social approval benefits of vaccinating also increases vaccine acceptance. These results suggest that providing information and shaping social expectations and incentives could both significantly increase vaccine uptake.
Disulfiram use is associated with lower risk of COVID-19: A retrospective cohort study
Authors: Fillmore Nathanael , Bell Steven , Shen Ciyue , Nguyen Vinh , La Jennifer , Dubreuil Maureen , Strymish Judith , Brophy Mary , Mehta Gautam , Wu Hao , Lieberman Judy , Do Nhan , Sander Chris
Published: October 2021

Effective, low-cost therapeutics are needed to prevent and treat COVID-19. Severe COVID-19 disease is linked to excessive inflammation. Disulfiram is an approved oral drug used to treat alcohol use disorder that is a potent anti-inflammatory agent and an inhibitor of the viral proteases. We investigated the potential effects of disulfiram on SARS-CoV-2 infection and disease severity in an observational study using a large database of clinical records from the national US Veterans Affairs healthcare system. A multivariable Cox regression adjusted for demographic information and diagnosis of alcohol use disorder revealed a reduced risk of SARS-CoV-2 infection with disulfiram use at a hazard ratio of 0.66 (34% lower risk, 95% confidence interval 24–43%). There were no COVID-19 related deaths among the 188 SARS-CoV-2 positive patients treated with disulfiram, in contrast to 5–6 statistically expected deaths based on the untreated population (P = 0.03). Our epidemiological results suggest that disulfiram may contribute to the reduced incidence and severity of COVID-19. These results support carefully planned clinical trials to assess the potential therapeutic effects of disulfiram in COVID-19.
Identification of the centrosomal maturation factor SSX2IP as a Wtip-binding partner by targeted proximity biotinylation
Authors: Reis Alice H. , Xiang Bo , Ossipova Olga , Itoh Keiji , Sokol Sergei Y.
Published: October 2021

Wilms tumor-1-interacting protein (Wtip) is a LIM-domain-containing adaptor that links cell junctions with actomyosin complexes and modulates actomyosin contractility and ciliogenesis in Xenopus embryos. The Wtip C-terminus with three LIM domains associates with the actin-binding protein Shroom3 and modulates Shroom3-induced apical constriction in ectoderm cells. By contrast, the N-terminal domain localizes to apical junctions in the ectoderm and basal bodies in skin multiciliated cells, but its interacting partners remain largely unknown. Targeted proximity biotinylation (TPB) using anti-GFP antibody fused to the biotin ligase BirA identified SSX2IP as a candidate protein that binds GFP-WtipN. SSX2IP, also known as Msd1 or ADIP, is a component of cell junctions, centriolar satellite protein and a targeting factor for ciliary membrane proteins. WtipN physically associated with SSX2IP and the two proteins readily formed mixed aggregates in overexpressing cells. By contrast, we observed only partial colocalization of full length Wtip and SSX2IP, suggesting that Wtip adopts a ‘closed’ conformation in the cell. Furthermore, the double depletion of Wtip and SSX2IP in early embryos uncovered the functional interaction of the two proteins during neural tube closure. Our results suggest that the association of SSX2IP and Wtip is essential for cell junction remodeling and morphogenetic processes that accompany neurulation. We propose that TPB can be a general approach that is applicable to other GFP-tagged proteins.
Modeling non-pharmaceutical interventions in the COVID-19 pandemic with survey-based simulations
Authors: Kaffai Marius , Heiberger Raphael H.
Published: October 2021

Governments around the globe use non-pharmaceutical interventions (NPIs) to curb the spread of coronavirus disease 2019 (COVID-19) cases. Making decisions under uncertainty, they all face the same temporal paradox: estimating the impact of NPIs before they have been implemented. Due to the limited variance of empirical cases, researchers could so far not disentangle effects of individual NPIs or their impact on different demographic groups. In this paper, we utilize large-scale agent-based simulations in combination with Susceptible-Exposed-Infectious-Recovered (SEIR) models to investigate the spread of COVID-19 for some of the most affected federal states in Germany. In contrast to other studies, we sample agents from a representative survey. Including more realistic demographic attributes that influence agents’ behavior yields accurate predictions of COVID-19 transmissions and allows us to investigate counterfactual what-if scenarios. Results show that quarantining infected people and exploiting industry-specific home office capacities are the most effective NPIs. Disentangling education-related NPIs reveals that each considered institution (kindergarten, school, university) has rather small effects on its own, yet, that combined openings would result in large increases in COVID-19 cases. Representative survey-characteristics of agents also allow us to estimate NPIs’ effects on different age groups. For instance, re-opening schools would cause comparatively few infections among the risk-group of people older than 60 years.
Peptide inhibition of acute lung injury in a novel two-hit rat model
Authors: Sampson Alana C. , Lassiter Brittany P. , Gregory Rivera Magdielis , Hair Pamela S. , Jackson Kaitlyn G. , Enos Adrianne I. , Vazifedan Turaj , Werner Alice L. , Glesby Marshall J. , Lattanzio Frank A. , Cunnion Kenji M. , Krishna Neel K.
Published: October 2021

Acute lung injury (ALI) often causes severe trauma that may progress to significant morbidity and mortality. ALI results from a combination of the underlying clinical condition of the patient (e.g., inflammation) with a secondary insult such as viral pneumonia or a blood transfusion. While the secondary insult may be variable, the rapidly progressive disease process leading to pulmonary failure is typically mediated by an overwhelming innate immunological or inflammatory reaction driven by excessive complement and neutrophil-mediated inflammatory responses. We recently developed a ‘two-hit’ ALI rat model mediated by lipopolysaccharide followed by transfusion of incompatible human erythrocytes resulting in complement activation, neutrophil-mediated ALI and free DNA in the blood indicative of neutrophil extracellular trap formation. The objective of this study was to evaluate the role of peptide inhibitor of complement C1 (RLS-0071), a classical complement pathway inhibitor and neutrophil modulator in this animal model. Adolescent male Wistar rats were infused with lipopolysaccharide followed by transfusion of incompatible erythrocytes in the presence or absence of RLS-0071. Blood was collected at various time points to assess complement C5a levels, free DNA and cytokines in isolated plasma. Four hours following erythrocyte transfusion, lung tissue was recovered and assayed for ALI by histology. Compared to animals not receiving RLS-0071, lungs of animals treated with a single dose of RLS-0071 showed significant reduction in ALI as well as reduced levels of C5a, free DNA and inflammatory cytokines in the blood. These results demonstrate that RLS-0071 can modulate neutrophil-mediated ALI in this novel rat model.
CO-IRv2: Optimized InceptionResNetV2 for COVID-19 detection from chest CT images
Authors: Mondal M. Rubaiyat Hossain , Bharati Subrato , Podder Prajoy
Published: October 2021

This paper focuses on the application of deep learning (DL) in the diagnosis of coronavirus disease (COVID-19). The novelty of this work is in the introduction of optimized InceptionResNetV2 for COVID-19 (CO-IRv2) method. A part of the CO-IRv2 scheme is derived from the concepts of InceptionNet and ResNet with hyperparameter tuning, while the remaining part is a new architecture consisting of a global average pooling layer, batch normalization, dense layers, and dropout layers. The proposed CO-IRv2 is applied to a new dataset of 2481 computed tomography (CT) images formed by collecting two independent datasets. Data resizing and normalization are performed, and the evaluation is run up to 25 epochs. Various performance metrics, including precision, recall, accuracy, F1-score, area under the receiver operating characteristics (AUC) curve are used as performance metrics. The effectiveness of three optimizers known as Adam, Nadam and RMSProp are evaluated in classifying suspected COVID-19 patients and normal people. Results show that for CO-IRv2 and for CT images, the obtained accuracies of Adam, Nadam and RMSProp optimizers are 94.97%, 96.18% and 96.18%, respectively. Furthermore, it is shown here that for the case of CT images, CO-IRv2 with Nadam optimizer has better performance than existing DL algorithms in the diagnosis of COVID-19 patients. Finally, CO-IRv2 is applied to an X-ray dataset of 1662 images resulting in a classification accuracy of 99.40%.