bluuebunny/crossref_metadata_2025 huggingface dataset:
Environment-stable sub-100 fs Er: fiber laser with a 3 dB bandwidth of 78 nm
Authors: Han Yi , Tian Haochen , Meng Fei , Wang Kai , Cao Shiying
Published: November 2022

A robust all polarization-maintaining (PM) passively mode-locked Er-doped fiber laser is demonstrated based on the biased nonlinear amplifier loop mirror (NALM). With a π/2 nonreciprocal free-space phase shifter, stable single pulse mode locking can be obtained at the central wavelength of 1565.7 nm with a 3 dB spectral bandwidth of 24.6 nm in the soliton regime. The repetition rate of the pulse train is 98.13 MHz. The direct output pulse duration is 109 fs, which is nearly transform-limited. After the intracavity dispersion management, the robust self-started mode-locking in the stretched-pulse regime is realized at 1564 nm, and the 3 dB spectral bandwidth reaches up to 78 nm. The repetition rate of the pulse train is 199.6 MHz. In particular, the direct output pulse width is only 77 fs with a low integrated relative intensity noise (RIN) of only 0.0044% (integrated from 1 Hz to 1 MHz). To the best of our knowledge, this is the shortest pulse width directly from the all-PM NALM laser oscillator.
Bound modes in the continuum in integrated photonic LiNbO3 waveguides: are they always beneficial?
Authors: Čtyroký Jiří , Petráček Jiří , Kuzmiak Vladimír , Richter Ivan
Published: November 2022

We discuss several types of integrated photonic LiNbO3 waveguides supporting propagation of modes which can be classified as bound states in the continuum (BICs). The key properties leading to the existence of BICs (or quasi-BICs) considered here are the material anisotropy, the waveguide birefringence, or the combination of both. Typical examples are titanium diffused and proton exchanged waveguides in bulk LiNbO3 crystals and recently proposed dielectric-loaded waveguides on LiNbO3 thin films. Proton exchanged waveguides in thin film LiNbO3 are considered, too. These waveguide structures are discussed from the point of view of their benefit for applications, especially in electro-optic devices.
Tracking registration of optical see-through augmented reality based on the Riemannian manifold constraint
Authors: An Zhe , Liu Yang
Published: November 2022

Two three-dimensional tracking registration methods combined with Riemannian manifold object constraints are proposed to solve problems of low accuracy and instability of three-dimensional tracking registration in sparse and complex scenes. A deep convolution neural network is used to extract three-dimensional instance objects from the location by analyzing reasons that affect registration accuracy in sparse and complex scenes. The three-dimensional tracking registration model is established according to the Riemannian manifold constraint relationship of instance objects in different states. The stability of the three-dimensional tracking registration algorithm is improved by combining inertial sensors, and cumulative error is optimized using instance object labels to improve algorithm robustness. The proposed algorithm can effectively improve the accuracy of three-dimensional tracking registration. It can improve the performance of augmented reality systems and be applied to power system navigation, medical, and other fields.
High-efficiency broadband third-order OAM mode converter based on a multi-period preset-twist long-period fiber grating
Authors: Chang Wenzhe , Feng Mao , Wang Pan , Wang Zhi , Liu Yan-Ge
Published: November 2022

All-fiber mode converters for generating orbital angular momentum (OAM) beams have many applications in optical communications, optical sensing and lasers. Currently, it is a great challenge to use a long-period fiber grating (LPFG) to broadband excite high-order OAM modes above the second-order. Here, we demonstrate a preset-twist LPFG fabrication method, which introduces asymmetry in the refractive index modulation area, for efficient generation of third-order modes. Through optimization, the generation of third-order OAM modes with 99.55% conversion efficiency, 0.81 dB insertion loss, and over 99% purity is achieved with only 40 pitch number. In addition, a multi-period preset-twist LPFG is proposed and demonstrated to achieve the excitation of broadband third-order mode with conversion efficiency of more than 99%, insertion loss of less than 1 dB, and mode purity of more than 90%. The 15 dB bandwidth (96.8% conversion efficiency) of the LPFG is 109 nm in the wavelength range from 1475 nm to 1584 nm, and the 20 dB bandwidth (99% conversion efficiency) of the LPFG is 92 nm from 1488 nm to 1580 nm. To the best of our knowledge, this is the first time to generate efficient and broadband third-order mode using a long-period fiber grating.
Precursor beat length and spun period measurement of a spun fiber using polarization optical frequency domain reflectometry
Authors: Dandu Prasad , Kim SungMoon , Gusarov Andrei , Sandah Fourier , Wuilpart Marc
Published: November 2022

In this Letter, a novel, to the best of our knowledge, nondestructive method for measuring the spun fiber parameters (precursor beat length and spun period) is presented both theoretically and experimentally. The proposed technique is based on analyzing the polarization optical frequency domain reflectometer traces. Experimental results are in agreement with the theoretical predictions.
112 orbital angular momentum modes amplification based on a 7RC-EDF with low differential mode gain
Authors: Wen Tianjin , Gao Shecheng , Zhang Jie , Tu Jiajing , Li Wei , Du Cheng , Liu Weiping , Li Zhaohui
Published: November 2022

We demonstrate 112 orbital angular momentum (OAM) modes amplification based on a designed and fabricated 7-ring-core erbium-doped fiber (7RC-EDF). The differential mode gain (DMG) of all the intra-core OAM modes in 7RC-EDF is effectively reduced. The DMG of intra-core modes can be suppressed by the high overlap between the signal modes and pump fundamental mode resulting from the designed structures of the ring core assisted by a trench. The differential gain of the inter-core can be controlled by the power of the core-pump configuration as well. With an experimentally optimized scheme of the pump power of each core, a record low-DMG of 2.8 dB among the 112 OAM modes (16-OAM-mode per core in the 7-core) is achieved at a wavelength of 1550 nm. The obtained favorable performance of the 112 OAM modes based on 7RC-EDF indicates it may promote a long-haul high-density OAM modes multiplexed transmission.
Compact fiber sensor for pH measurement based on the composite effect of hydrogel deformation and LC refractive index variation
Authors: Ma Zhenyu , Sun Jing , Zhou Sijie , Shan WenJun , Yan Yunxiang , Liu Yongjun
Published: November 2022

A novel, to the best of our knowledge, type of compact pH fiber sensor combined with a hydrogel based on the whispering gallery mode (WGM) is proposed and integrates a liquid crystal (LC) microdroplet in a capillary in a compact structure as small as 180 µm. In the research, the hydrogel performs both as a supporting frame and a responsive material that causes morphological deformation of the LC microdroplet with pH variation. Moreover, a new phenomenon of pH-induced LC refractive index variation is observed and applied in the pH measurement, so that the acid itself can also lead the LC microdroplet structure transition. Thus, the WGM method is applied to detect the composite effect simultaneously to improve the sensing capability. The sensitivity of the sensor in the pH range from 4.55 to 6.86 reaches 3.19 nm/pH. The response time is short, within 60 s. The simple and compact structure of the sensor reduces the cost and enhances the stability, which is of great potential for biomedical pH measurement.
Mid-infrared laser operation of Er3+-doped BaF2 and (Sr,Ba)F2 crystals
Authors: Normani Simone , Basyrova Liza , Loiko Pavel , Benayad Abdelmjid , Braud Alain , Hideur Ammar , Camy Patrice
Published: November 2022

We report on the first, to our knowledge, mid-infrared laser operation of two Er3+-doped barium-containing fluorite-type crystals, BaF2 and (Sr,Ba)F2, featuring a low-phonon energy behavior. A continuous wave 4.9 at.% Er:(Sr,Ba)F2 laser generated 519 mW at 2.79 µm with a slope efficiency of 25.0% and a laser threshold of 27 mW. The vibronic and spectroscopic properties of these crystals are determined. The phonon energy of (Sr,Ba)F2 is as low as 267 cm−1. The Er3+ ions in this crystal feature a broadband emission owing to the 4I11/2 → 4I13/2 transition and a long luminescence lifetime of the 4I11/2 level (10.6 ms) making this compound promising for low-threshold, broadly tunable, and pulsed 2.8-µm lasers.
Desensitization design method of a freeform optical system based on local curve control
Authors: Qin Zichang , Meng Qingyu , Wang Xiaodong
Published: November 2022

In this Letter, an error sensitivity evaluation function of freeform optical systems is proposed, and a desensitization design method is established. This method adopts the idea of micro-elements and, based on geometric optics theory, studies the relationship between the local curve of the freeform surface and the change of the wavefront error (ΔWE) when the optical system is disturbed by the position error, and realizes the desensitization design of the optical system. By simply changing the evaluation function, the method can be applied to the desensitization design of any optical system with any surface (spherical, aspheric, and freeform surface).
Attentional enhancement predicts individual differences in visual working memory under go/no-go search conditions
Authors: Tay Daniel , McDonald John J.
Published: November 2022

Attention-control processes transfer relevant information to visual working memory (WM) and prevent irrelevant information from consuming WM resources. Although event-related potentials (ERPs) have revealed attention-control processes associated with enhancement of relevant stimuli (targets) and suppression of irrelevant stimuli (distractors), only the suppressive processes have been found to predict WM capacity. We hypothesised a link between target-enhancement processes and WM capacity would be revealed in a task that requires more control than the conventional visual search paradigms used to study target selection. Here, participants searched for a pop-out target on Go trials and withheld responses on an equal number of randomly intermixed No-Go trials, depending on the colour of the stimulus array. Magnitudes of ERP indices associated with target enhancement (the singleton detection positivity, SDP, and N2pc) were positively correlated with individual differences in WM capacity. These relationships vanished when participants searched for the pop-out target on every trial, regardless of stimulus-array colour. Inhibitory processes associated with suppressing distractors (PD) and withholding responses (no-go P3) on No-Go trials did not predict WM capacity. These findings indicate that target-enhancement mechanisms control access to WM in search tasks that require dynamic control and disconfirm the view that the gateway to WM is entirely inhibitory by nature.
Role of path information in visual perception of joint stiffness
Authors: West A. Michael , Huber Meghan E. , Hogan Neville
Published: November 2022

Humans have an astonishing ability to extract hidden information from the movement of others. In previous work, subjects observed the motion of a simulated stick-figure, two-link planar arm and estimated its stiffness. Fundamentally, stiffness is the relation between force and displacement. Given that subjects were unable to physically interact with the simulated arm, they were forced to make their estimates solely based on observed kinematic information. Remarkably, subjects were able to correctly correlate their stiffness estimates with changes in the simulated stiffness, despite the lack of force information. We hypothesized that subjects were only able to do this because the controller used to produce the simulated arm’s movement, composed of oscillatory motions driving mechanical impedances, resembled the controller humans use to produce their own movement. However, it is still unknown what motion features subjects used to estimate stiffness. Human motion exhibits systematic velocity-curvature patterns, and it has previously been shown that these patterns play an important role in perceiving and interpreting motion. Thus, we hypothesized that manipulating the velocity profile should affect subjects’ ability to estimate stiffness. To test this, we changed the velocity profile of the simulated two-link planar arm while keeping the simulated joint paths the same. Even with manipulated velocity signals, subjects were still able to estimate changes in simulated joint stiffness. However, when subjects were shown the same simulated path with different velocity profiles, they perceived motions that followed a veridical velocity profile to be less stiff than that of a non-veridical profile. These results suggest that path information (displacement) predominates over temporal information (velocity) when humans use visual observation to estimate stiffness.
Western blot using Trypanosoma cruzi chimeric recombinant proteins for the serodiagnosis of chronic Chagas disease: A proof-of-concept study
Authors: Daltro Ramona Tavares , Santos Emily Ferreira , Silva Ângelo Antônio Oliveira , Maron Freitas Natália Erdens , Leony Leonardo Maia , Vasconcelos Larissa Carvalho Medrado , Luquetti Alejandro Ostermayer , Celedon Paola Alejandra Fiorani , Zanchin Nilson Ivo Tonin , Regis-Silva Carlos Gustavo , Santos Fred Luciano Neves
Published: November 2022

Background

Chagas disease (CD) is caused by Trypanosoma cruzi. The chronic phase of CD is characterized by the presence of IgG anti-T. cruzi antibodies; and diagnosis is performed by serological methods. Because there is no reliable test that can be used as a reference test, WHO recommends the parallel use of two different tests for CD serodiagnosis. If results are inconclusive, samples should be subjected to a confirmatory test, e.g., Western blot (WB) or PCR. PCR offers low sensitivity in the chronic phase, whereas few confirmatory tests based on the WB method are commercially available worldwide. Therefore, new diagnostic tools should be evaluated to fill the gap in CD confirmatory tests. In recent years, four chimeric recombinant antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4) have been evaluated in phase I, II and III studies using ELISA, liquid microarray and immunochromatography with 95–100% accuracy. Given the high diagnostic performance of these antigens, the present study investigated the ability of these molecules to diagnose chronic CD using a WB testing platform.

Methodology/Principal findings

In this study, we analyzed the diagnostic potential of four chimeric antigens using 40 T. cruzi-positive, 24-negative, and three additional positive samples for visceral leishmaniasis (i.e., potentially cross-reactive) using WB as the diagnostic platform. Checkerboard titration with different dilutions of antigens, conjugated antigens, and serum samples was performed to standardize all assays. All IBMP antigens achieved 100% sensitivity, specificity, and accuracy, with the exception of IBMP-8.3, which had 100% specificity despite lack of significance, but lower sensitivity (95%) and accuracy (96.9%). No cross-reactivity was observed in samples positive for leishmaniasis.

Conclusions/Significance

The present phase I (proof-of-concept) study demonstrated the high diagnostic potential of these four IBMP antigens to discriminate between T. cruzi-positive and -negative samples, making them candidates for phase II and confirmatory testing with WB.
Neurological manifestations of scrub typhus infection: A systematic review and meta-analysis of clinical features and case fatality
Authors: Alam Ali M. , Gillespie Conor S. , Goodall Jack , Damodar Tina , Turtle Lance , Vasanthapuram Ravi , Solomon Tom , Michael Benedict D.
Published: November 2022

Background

Scrub typhus has become a leading cause of central nervous system (CNS) infection in endemic regions. As a treatable condition, prompt recognition is vital. However, few studies have focused on describing the symptomology and outcomes of neurological scrub typhus infection. We conducted a systematic review and meta-analysis to report the clinical features and case fatality ratio (CFR) in patients with CNS scrub typhus infection.

Methods

A search and analysis plan was published in PROSPERO [ID 328732]. A systematic search of PubMed and Scopus was performed and studies describing patients with CNS manifestations of proven scrub typhus infection were included. The outcomes studied were weighted pooled prevalence (WPP) of clinical features during illness and weighted CFR.

Results

Nineteen studies with 1,221 (656 adults and 565 paediatric) patients were included. The most common clinical features in CNS scrub typhus were those consistent with non-specific acute encephalitis syndromes (AES), such as fever (WPP 100.0% [99.5%-100.0%, I2 = 47.8%]), altered sensorium (67.4% [54.9–78.8%, I2 = 93.3%]), headache (65.0% [51.5–77.6%, I2 = 95.1%]) and neck stiffness 56.6% (29.4–80.4%, I2 = 96.3%). Classical features of scrub typhus were infrequently identified; an eschar was found in only 20.8% (9.8%-34.3%, I2 = 95.4%) and lymphadenopathy in 24.1% (95% CI 11.8% - 38.9%, I2 = 87.8%). The pooled CFR (95% CI) was 3.6% (1.5%– 6.4%, I2 = 67.3%). Paediatric cohorts had a CFR of 6.1% (1.9–12.1%, I2 = 77%) whilst adult cohorts reported 2.6% (0.7–5.3%, I2 = 43%).

Conclusion

Our meta-analyses illustrate that 3.6% of patients with CNS manifestations of scrub typhus die. Clinicians should have a high index of suspicion for scrub typhus in patients presenting with AES in endemic regions and consider starting empiric treatment whilst awaiting results of investigations, even in the absence of classical signs such as an eschar or lymphadenopathy.
A mouse model of peripheral nerve injury induced by Japanese encephalitis virus
Authors: Wang Xiaoli , Wang Guowei , Yang Huan , Fu Shihong , He Ying , Li Fan , Wang Huanyu , Wang Zhenhai
Published: November 2022

Japanese encephalitis virus (JEV) is the most important cause of acute encephalitis in Eastern/Southern Asia. Infection with this virus also induces peripheral nerve injury. However, the disease pathogenesis is still not completely understood. Reliable animal models are needed to investigate the molecular pathogenesis of this condition. We studied the effect of Japanese encephalitis virus infection in C57BL/6 mice after a subcutaneous challenge. Limb paralysis was determined in mice using behavioral tests, including a viral paralysis scale and the hanging wire test, as well as by changes in body weight. Nerve conduction velocity and electromyography testing indicated the presence of demyelinating neuropathy of the sciatic nerve. Pathological changes in neural tissues were examined by immunofluorescence and transmission electron microscopy, which confirmed that the predominant pathologic change was demyelination. Although Western blots confirmed the presence of the virus in neural tissue, additional studies demonstrated that an immune-induced inflammatory response resulted in severe never injury. Immunofluorescence confirmed the presence of Japanese encephalitis virus in the brains of infected mice, and an inflammatory reaction was observed with hematoxylin-eosin staining as well. However, these observations were inconsistent at the time of paralysis onset. In summary, our results demonstrated that Japanese encephalitis virus infection could cause inflammatory demyelination of the peripheral nervous system in C57BL/6 mice.
Facing flood disaster: A cluster randomized trial assessing communities’ knowledge, skills and preparedness utilizing a health model intervention
Authors: Mhd Noor Mohd Tariq , Kadir Shahar Hayati , Baharudin Mohd Rafee , Syed Ismail Sharifah Norkhadijah , Abdul Manaf Rosliza , Md Said Salmiah , Ahmad Jamilah , Muthiah Sri Ganesh
Published: November 2022

Floods occur when a body of water overflows and submerges normally dry terrain. Tropical cyclones or tsunamis cause flooding. Health and safety are jeopardized during a flood. As a result, proactive flood mitigation measures are required. This study aimed to increase flood disaster preparedness among Selangor communities in Malaysia by implementing a Health Belief Model-Based Intervention (HEBI). Selangor’s six districts were involved in a single-blinded cluster randomized controlled trial Community-wide implementation of a Health Belief Model-Based Intervention (HEBI). A self-administered questionnaire was used. The intervention group received a HEBI module, while the control group received a health talk on non-communicable disease. The baseline variables were compared. Immediate and six-month post-intervention impacts on outcome indicators were assessed. 284 responses with a 100% response rate. At the baseline, there were no significant differences in ethnicity, monthly household income, or past disaster experience between groups (p>0.05). There were significant differences between-group for intervention on knowledge, skills, preparedness (p<0.001), Perceived Benefit Score (p = 0.02), Perceived Barrier Score (p = 0.03), and Cues to Action (p = 0.04). GEE analysis showed receiving the HEBI module had effectively improved knowledge, skills, preparedness, Perceived Benefit Score, Perceived Barrier Score, and Cues to Action in the intervention group after controlling the covariate. Finally, community flood preparedness ensured that every crisis decision had the least impact on humans. The HEBI module improved community flood preparedness by increasing knowledge, skill, preparedness, perceived benefit, perceived barrier, and action cues. As a result, the community should be aware of this module.

Clinical trial registration: The trial registry name is Thai Clinical Trials Registry, trial number TCTR20200202002.
Association between recent overdose and chronic pain among individuals in treatment for opioid use disorder
Authors: Hartz Sarah M. , Culverhouse Robert C. , Mintz Carrie M. , Ellis Matthew S. , Kasper Zachary A. , Cavazos-Rehg Patricia , Grucza Richard A. , Bierut Laura J. , Cicero Theodore J.
Published: November 2022

Chronic pain increases risk for opioid overdose among individuals with opioid use disorder. The purpose of this study is to evaluate the relationship between recent overdose and whether or not chronic pain is active. 3,577 individuals in treatment for opioid use disorder in 2017 or 2018 were surveyed regarding recent overdoses and chronic pain. Demographics from the 2017 Treatment Episode Data Set, which includes all U.S. facilities licensed or certified to provide substance use care, were used to evaluate the generalizability of the sample. χ2tests and logistic regression models were used to compare associations between recent overdoses and chronic pain. Specifically, active chronic pain was associated with opioid overdose among people in treatment for opioid use disorder. Individuals with active chronic pain were more likely to have had a past month opioid overdose than those with no history chronic pain (adjusted OR = 1.55, 95% CI 1.16–2.08, p = 0.0003). In contrast, individuals with prior chronic pain, but no symptoms in the past 30 days, had a risk of past month opioid overdose similar to those with no history of chronic pain (adjusted OR = 0.88, 95% CI 0.66–1.17, p = 0.38). This suggests that the incorporation of treatment for chronic pain into treatment for opioid use disorder may reduce opioid overdoses.
Anti-leishmanial physalins—Phytochemical investigation, in vitro evaluation against clinical and MIL-resistant L. tropica strains and in silico studies
Authors: Bano Saira , Bibi Memoona , Farooq Saba , Zafar Humaira , Shaikh Muniza , Khoso Behram Khan , Yousuf Sammer , Choudhary M. Iqbal
Published: November 2022

Cutaneous leishmaniasis (CL) is a major health problem in over 98 countries of the world, including Pakistan. The current treatments are associated with a number of adverse effects and availability problem of drugs. Therefore, there is an urgent need of easily available and cost effective treatments of CL- in Pakistan. The bioassay-guided fractionation and purification of crude extract of Physalis minima has led to the isolation of a new aminophysalin B (1), and eight known physalins, physalin B (2), 5ß,6ß-epoxyphysalin B (3), 5α-ethoxy-6ß-hydroxy-5,6-dihydrophysalin B (4), physalin H (5), 5ß,6ß-epoxyphysalin C (6), and physalin G (7), K (8), and D (9). It is worth noting that compound 1 is the second member of aminophysalin series, whereas compound 6 was fully characterized for the first time. The structures of compounds 1–9 were elucidated by spectroscopic techniques Whereas, the structural assignments of compounds 1 and 8 were also supported by single-crystal X-ray diffraction studies. The anti-leishmanial activity of isolated physlains 1–9 was evaluated against Leishmania major and Leishmania tropica promastigotes. Compounds 2, 3, and 5–7 (IC50 = 9.59 ± 0.27–23.76 ± 1.10 μM) showed several-fold more potent activity against L. tropca than tested drug miltefosine (IC50 = 42.75 ± 1.03 μm) and pentamidine (IC50 = 27.20 ± 0.01 μM). Whereas compounds 2, 3 and 5 (IC50 = 3.04 ± 1.12–3.76 ± 0.85 μM) were found to be potent anti-leishmanial agents against L. major, several fold more active than tested standard miltefosine (IC50 = 25.55 ± 1.03 μM) and pentamidine (IC50 = 27.20 ± 0.015 μM). Compounds 4 (IC50 = 74.65 ± 0.81 μM) and 7 (IC50 = 39.44 ± 0.65 μM) also showed potent anti-leishmanial ativity against the miltefosine-unresponsive L. tropica strain (MIL resistant) (miltefosine IC50 = 169.55 ± 0.78 μM). Molecular docking and predictive binding studies indicated that these inhibitors may act via targeting important enzymes of various metabolic pathways of the parasites.
Psychometric properties and cross-cultural adaptation of the Indonesian version of the Brief COPE in a sample of advanced cancer patients
Authors: Huda Nurul , Lin Yen-Kuang , Shaw Malissa Kay , Hsu Yu-Ying , Chang Hsiu-Ju
Published: November 2022

The Brief COPE Inventory has been proven as acceptable psychometric properties to examine coping strategies among cancer patients. However, most psychometric testing studies have been carried out in Western countries, raising concerns about the properties’ relevance and applicability in other cultural contexts. This study aimed to present psychometric properties of the Brief COPE in a sample of patients with advanced cancer in Indonesia. Specifically, we intended to examine the factorial structure and the measure’s validity and reliability. This study included 440 patients from the original study who completed the Indonesian version of Brief COPE. We used exploratory factor analysis and confirmatory factor analysis to assess factor structure and evaluate the structural model fit, respectively. Reliability was demonstrated by internal consistency represented by Cronbach’s alpha coefficient. The factor analysis identified a 21-items scale with 5-factors (avoidance, religion and acceptance, social support coping, problem solving and distraction). Confirmatory factor analysis demonstrated a good model fit. For the whole scale and its subscales Cronbach’s alpha coefficients were acceptable signifying good reliability. Convergent, divergent validity and contrast group comparison were evidenced by significant correlations among subscales and the other instruments used. This study shows that the Indonesian version of Brief COPE is a reliable and valid instrument to measure coping in advanced cancer patients and is ready for use amongst this population in the Indonesian cultural context.
A simulation study: Using dual ancillary variable to estimate population mean under stratified random sampling
Authors: Ahmad Sohaib , Hussain Sardar , Yasmeen Uzma , Aamir Muhammad , Shabbir Javid , El-Morshedy M. , Al-Bossly Afrah , Ahmad Zubair
Published: November 2022

In this paper, we propose an improved ratio-in-regression type estimator for the finite population mean under stratified random sampling, by using the ancillary varaible as well as rank of the ancillary varaible. Expressions of the bias and mean square error of the estimators are derived up to the first order of approximation. The present work focused on proper use of the ancillary variable, and it was discussed how ancillary variable can improve the precision of the estimates. Two real data sets as well as simulation study are carried out to observe the performances of the estimators. We demonstrate theoretically and numerically that proposed estimator performs well as compared to all existing estimators.
Prevalence of Schistosoma mansoni infection among fishermen in Busega district, Tanzania
Authors: Mang’ara Revocatus J. L. , Ngasala Billy , John Winfrida
Published: November 2022

Background

Schistosoma (S.) mansoni infection is endemic in all regions around Lake Victoria and affects all age groups to different degrees. In most endemic areas, less attention has been paid to determining the prevalence of infection, sanitation status, and knowledge about intestinal schistosomiasis (KIS) in fishermen. Therefore, the purpose of this study was to establish the prevalence of S. mansoni infection and associated factors among fishermen in the Busega district.

Materials and methods

A cross-sectional study was conducted among fishermen in July, 2020 in five fishing villages in the Busega district located along Lake Victoria. A total of 352 fishermen were interviewed with regard to their sanitation status and level of KIS. A single stool sample from fishermen was examined for S.mansoni eggs by using the Formalin-Ether Concentration technique. The potential factors associated with S. mansoni infection were explored using multivariable logistic regression.

Results

The prevalence of S. mansoni infection was high (65.0%) among fishermen and varied with age, whereby fishermen aged ≤36 years had the highest prevalence. Fishermen had a low level of KIS and the majority of them reported practicing open defecation during fishing (81%). These fishermen with a low level of KIS and who reported defecating in open areas during fishing had 2.8 times (95% CI: 1.0–7.2) and 2.1 times (95% CI: 1.1–3.9) higher odds of being infected with S. mansoni than those with a high level of KIS and those who did not report defecating in open areas during fishing, respectively.

Conclusion

S. mansoni infection was high among fishermen in the Busega district. Furthermore, fishermen had a low level of KIS and were reported to have defecated in open areas during fishing. Infection with S. mansoni was associated with age, a low level of KIS and open defecation behaviour during fishing. Therefore, mass drug administration (MDA) with praziquantel, health education, and sanitation behaviour change interventions were needed.
Specified-duration shapers for suppressing residual vibrations
Authors: Kang Brian Byunghyun
Published: November 2022

Input-shaping control has received considerable research attention for suppressing residual vibrations. Although numerous studies have been conducted on designing input shapers with arbitrary robustness to modeling errors, no studies have focused on the design of input shapers with arbitrarily specified shaping times. In this study, a specified-duration (SD) shaper, which is an input shaper with an arbitrarily specified shaping time, and a systematic method to design an SD shaper using impulse vectors are proposed. As the specified shaping time increases, the SD shaper increases the number of impulses one by one according to the number of added derivative constraints, thereby improving robustness to modeling errors. The performance of the SD shaper was evaluated for a second-order system through computer simulations. The simulation results revealed that the SD shaper suppresses residual vibrations of the vibratory system at the specified shaping time. The validity of the SD shaper was experimentally verified using a horizontal beam vibration apparatus. The results of this study provide insight into the development of vibration suppression strategies with input shaping control.
Perception of Health Care Workers (HCWs) towards early antenatal booking in Fiji: A qualitative study
Authors: Maharaj Renita , Mohammadnezhad Masoud
Published: November 2022

Background

Early booking or registration into Antenatal Care (ANC) can be defined as initiation of ANC before 12 weeks of gestation and is important for the best health outcome of the mother and the baby. Delayed initiation of ANC has been linked to increased rate of maternal and fetal mortality. There is international consensus that ANC should begin within first trimester yet pregnant women delay initiation of ANC. Health Care Workers (HCWs) understanding of reasons for this can improve patient provider relationship.

Objectives

This study aims to explore the perception of the HCWs in Fiji towards early antenatal booking.

Methods

A qualitative study was employed using four Focus-Group Discussions (FGDs)with the HCWs who provide health care service for pregnant women in Ba Mission Hospital (BMH) in 2020. Each group comprised of medical officers, mid-wives and registered nurse who were chosen purposively. A semi-structured open ended questionnaire was used to guide the discussion. Data was transcribed and analyzed manually using thematic content analysis using the following process: familiarization, coding, identifying themes, reviewing and refining, integration and interpretation.

Results

There was a total of 18 HCWs for the FGDs. The mean age of the participants was 37.4±11.8years. The three themes identified were: knowledge of HCWs on early booking, their perceived barriers and perceived enabling factors to early antenatal booking. The FGDs identified that the HCWs had adequate knowledge on early initiation of ANC and that there were a range of barriers to early initiation of ANC. The HCWs also suggested factors that could enable women to book early.

Conclusion

Based on the study it can be concluded that the HCWs have a positive perception of early antenatal booking, however, there are various factors that contribute to delayed antenatal booking. The barriers to early ANC are both an opportunity and a challenge to strengthen and review the maternal services offered. The enabling factors should be reinforced from an individual level to the health system and the general context. The implications of the barriers and enabling factors identified in this study is to implement evidence-based policies to improve early antenatal booking in Ba, Fiji.
Marine fungi showing multifunctional activity against human pathogenic microbes and cancer
Authors: Ameen Fuad , AlNAdhari Saleh , Al-Homaidan Ali A.
Published: November 2022

Multifunctional drugs have shown great promise in biomedicine. Organisms with antimicrobial and anticancer activity in combination with antioxidant activity need further research. The Red Sea and the Arabian Gulf coasts were randomly sampled to find fungi with multifunctional activity. One hundred strains (98 fungi and 2 lichenized forms) were isolated from 15 locations. One-third of the isolates inhibited clinical bacterial (Staphylococcus aureus, Bacillus subtilis, Vibrio cholerae, Salmonella typhi, S. paratyphi) and fungal pathogens (Talaromycets marneffei, Malassezia globose, Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus) and four cancer cell lines (Hep G2 liver, A-549 lung, A-431skin, MCF 7 breast cancer). Bacterial and cancer inhibition was often accompanied by a high antioxidant activity, as indicated by the principal component analysis (PCA). PCA also indicated that fungal and bacterial pathogens appeared to be inhibited mostly by different marine fungal isolates. Strains with multifunctional activity were found more from the Rea Sea than from the Arabian Gulf coasts. The highest potential for multifunctional drugs were observed for Acremonium sp., Acrocalymma sp., Acrocalymma africana, Acrocalymma medicaginis (activity reported for the first time), Aspergillus sp. Cladosporium oxysporum, Emericellopsis alkaline, Microdochium sp., and Phomopsis glabrae. Lung, skin, and breast cancers were inhibited 85%–97% by Acremonium sp, while most of the isolates showed low inhibition (ca 20%). The highest antifungal activity was observed for Acremonium sp., Diaporthe hubeiensis, Lasiodiplodia theobromae, and Nannizia gypsea. One Acremonium sp. is of particular interest to offer a multifunctional drug; it displayed both antifungal and antibacterial activity combined with high antioxidant activity (DPPH scavenging 97%). A. medicaginis displayed combined antibacterial, anticancer, and antioxidant activity being of high interest. Several genera and some species included strains with both high and low biological activities pointing out the need to study several isolates to find the most efficient strains for biomedical applications.
Investigating the effects of antipsychotics on brain insulin action: Study protocol for a multi-modality magnetic resonance imaging (MRI) study in healthy controls
Authors: Stogios Nicolette , Hamel Laurie , Smith Emily , Sanches Marcos , Remington Gary , Voineskos Aristotle , Dash Satya , Graff-Guerrero Ariel , Hahn Margaret , Agarwal Sri Mahavir
Published: November 2022

Antipsychotics (APs) are the cornerstone of treatment for schizophrenia (SCZ) but are unfortunately associated with serious metabolic adverse effects including weight gain and type 2 diabetes. The pathophysiology of AP-induced metabolic dysfunction is largely undetermined. Brain insulin resistance has been posited to be at the cross-roads of many cognitive and metabolic disorders, and disruption of central insulin action has emerged as a possible explanatory mechanism underlying AP induced metabolic dysfunction. Previous studies suggest that change in neuroimaging-based parameters with intranasal insulin administration can be leveraged to investigate brain insulin resistance. In this proof-of-concept study, we will utilize neural signatures of insulin action in the brain to examine if APs disrupt brain insulin signaling. It is hypothesized that: 1) intranasal insulin (INI), but not intranasal placebo (INP), will change cerebral blood flow and resting state connectivity, as well as increase glutamate levels in the striatum and dorsolateral prefrontal cortex; 2) oral olanzapine (OLA), but not oral placebo (PL), will inhibit the effect of INI on these parameters. Thirty-two healthy volunteers will undergo a single blind, cross-over design, wherein all participants receive the following four treatment combinations, 2–6 weeks apart, in a random sequence: INP + PL, INP + OLA, INI + PL, and INI + OLA. Participants will undergo an MRI-based assay of brain insulin resistance 15 minutes after administering 160 IU INI or INP. The scanning protocol includes resting and task-based functional MRI, arterial spin labelling, and proton magnetic resonance spectroscopy. Demonstrating that OLA can acutely induce brain insulin resistance is clinically relevant to metabolic health in SCZ. Evidence of brain insulin resistance induced by acute AP dosing can inform the early use of adjunctive insulin sensitizers for the treatment of metabolic comorbidities associated with AP treatment in severe mental illness.

Trial registration

ClinicalTrials.gov Registration: NCT03741478.
The effects of competency-based training model in the training of new nurses: A meta-analysis and systematic review
Authors: Chen Suqing , Zhang Chenxia , Li Wanling
Published: November 2022

Background

It is necessary to evaluate the effects of competency-based training (CBT) model in the clinical training of new nurses, to provide insights to the management of nurses.

Methods

We searched PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, Wanfang and Weipu Databases for the randomized controlled trials (RCTs) on the application effect of CBT in new nurse training up to December 15, 2021. Two investigators independently screened the literature, extracted the data and evaluated the quality of the literatures. RevMan 5.3 software was used for meta-analysis.

Results

A total of 7 RCTs involving 639 new nurses were included. Meta-analyses indicated that CBT improved the ability of clinical nursing care [SMD = 1.52, 95%CI (0.13~2.90), P = 0.03], critical thinking and innovation[SMD = 0.69, 95%CI (0.43~0.95), P<0.001], interpersonal communication[SMD = 0.74, 95%CI (0.51~0.97), P<0.001], professional construction and development[SMD = 1.92, 95%CI (1.41~2.42), P<0.001], level of comprehensive knowledge[SMD = 1.20, 95%CI (0.63~1.76), P<0.001] and level of good personal traits[SMD = 1.89, 95%CI (1.27~2.50), P<0.001].The results of Egger regression tests indicated that there were no statistical biases amongst the synthesized outcomes (all P>0.05).

Conclusions

CBT is beneficial for improving the competency of newly recruited nurses. More RCTs from different population and regions are needed to further elucidate the role of CBT in nurse management.
Spatial and seasonal variation in macrozoobenthic density, biomass and community composition in a major tropical intertidal area, the Bijagós Archipelago, West-Africa
Authors: Coelho Ana Pinto , Henriques Mohamed , Rocha Afonso Duarte , Paulino João , Schaars Loran Kleine , Ramos Catarina , de Barros Aissa Regalla , Catry Teresa , Granadeiro José Pedro , Piersma Theunis , Alves José Augusto
Published: November 2022

The coastal intertidal ecosystem of the Bijagós Archipelago, Guinea-Bissau, one of the largest and most important in West Africa, sustains a considerable proportion of the migratory shorebird populations of the East Atlantic Flyway and operates as a nursery area for benthic fish in the region. The macrozoobenthos in these mudflats constitute the main food source for both groups so that spatial and temporal variation in their abundance and community composition is likely to influence the abundance and distribution of fish and birds. In this study we described the spatial and temporal dynamics in the density, biomass, and community composition of macrozoobenthos across six intertidal flats in three islands of the Bijagós Archipelago. Overall, the Bijagós Archipelago was characterised by a highly species-rich macrozoobenthic community, with ca. 88 taxa identified across all sites, reaching a mean density of 1871 ± 58.3 ind.m-2(mean ± SE) and mean biomass of 5.65 ± 0.41 g of AFDM.m-2(ash-free dry mass per m2), values much lower than what was described for nearby intertidal areas, namely the Band d’Arguin, Mauritania. Density and biomass of major macrozoobenthos classes (Bivalvia, Polychaeta, Malacostraca and Gastropoda) differed across sites and months, displaying an overall increase in density towards the final months of the dry season (March and April). Similarly, community composition also differed significantly between sites and throughout the season. The site with most distinct community composition (Adonga) supported low diversity and high abundance of a few bivalve species, whilst other two sites that hosted the most diverse communities, were also the most similar between them (Anrumai and Abu). These spatial and temporal patterns constitute an important baseline to improve knowledge of this intertidal ecosystem and will contribute towards a better understanding of the spatial and temporal distribution patterns of their consumers.
Diagnostic accuracy of a SARS-CoV-2 rapid antigen test among military and civilian personnel of an Air Force airport in central Italy
Authors: Verde Paola , Marcantonio Cinzia , Costantino Angela , Martina Antonio , Simeoni Matteo , Taffon Stefania , Tritarelli Elena , Campanella Carmelo , Cresta Raffaele , Bruni Roberto , Ciccaglione Anna Rita , Pisani Giulio , Nisini Roberto , Spada Enea
Published: November 2022

Background

Most SARS-CoV-2 rapid antigen detection tests (RADTs) validation studies have been performed on specimens from COVID-19 patients and negative controls or from mostly symptomatic individuals. Herein we evaluated the diagnostic accuracy of AFIAS COVID-19 Ag, hereinafter denominated as AFIAS, during a COVID-19 screening program surveillance testing conducted among personnel of an Italian military airport.

Methods

Nasopharyngeal swabs (NPSs) were collected from study participants and were analysed by both AFIAS and RT-PCR assay. A questionnaire collecting demographic and exposure data were administered to all participants. AFIAS accuracy parameters including Cohen’s kappa (K) were determined.

Results

Overall, from November 2020 to April 2021, 1294 (NPSs) were collected from 1183 participants (88.6% males, 11.4% females; mean age were 41.3, median age 42). Forty-nine NPSs (3.78%) were positive by RT-PCR, while 54 NPSs were positive by AFIAS. Overall baseline sensitivity, specificity, positive and negative predictive values were 0.633, 0.981, 0.574, 0.985, respectively and K was 0.585 (moderate). AFIAS sensitivity tended to be higher for NPSs with higher viral load. A higher sensitivity (0.944) compared to the overall baseline sensitivity (0.633) was also found for NPSs from participants with COVID-19 compatible symptoms, for which K was 0.891 (almost perfect). Instead, AFIAS sensitivity was quite poor for NPSs from asymptomatic participants. Most false negative NPSs in this group had moderate viral load.

Conclusion

Overall, AFIAS showed high specificity but only moderate sensitivity, mainly because of the high proportion of asymptomatic participants. However, AFIAS showed good sensitivity for NPSs with high viral load and nearly optimal accuracy parameters for NPSs from participants with COVID-19 compatible symptoms. Thus, taking into consideration its performance features, this test can be useful for COVID-19 case identification and management as well as for infection control.
Molecular modelling of the HCMV IL-10 protein isoforms and analysis of their interaction with the human IL-10 receptor
Authors: Pantaleão Simone Queiroz , Camillo Lívia de Moraes Bomediano , Neves Tainan Cerqueira , Menezes Isabela de Godoy , Stangherlin Lucas Matheus , Batista Helena Beatriz de Carvalho Ruthner , Poole Emma , Nevels Michael , Philot Eric Alisson , Scott Ana Ligia , Carlan da Silva Maria Cristina
Published: November 2022

The human cytomegalovirus (HCMV) UL111A gene encodes several homologs of the cellular interleukin 10 (cIL-10). Alternative splicing in the UL111A region produces two relatively well-characterized transcripts designated cmvIL-10 (isoform A) and LAcmvIL-10 (isoform B). The cmvIL-10 protein is the best characterized, both structurally and functionally, and has many immunosuppressive activities similar to cIL-10, while LAcmvIL-10 has more restricted biological activities. Alternative splicing also results in five less studied UL111A transcripts encoding additional proteins homologous to cIL-10 (isoforms C to G). These transcripts were identified during productive HCMV infection of MRC-5 cells with the high passage laboratory adapted AD169 strain, and the structure and properties of the corresponding proteins are largely unknown. Moreover, it is unclear whether these protein isoforms are able to bind the cellular IL-10 receptor and induce signalling. In the present study, we investigated the expression spectrum of UL111A transcripts in fully permissive MRC-5 cells and semi permissive U251 cells infected with the low passage HCMV strain TB40E. We identified a new spliced transcript (H) expressed during productive infection. Using computational methods, we carried out molecular modelling studies on the three-dimensional structures of the HCMV IL-10 proteins encoded by the transcripts detected in our work (cmvIL-10 (A), LAcmvIL-10 (B), E, F and H) and on their interaction with the human IL-10 receptor (IL-10R1). The modelling predicts clear differences between the isoform structures. Furthermore, the in silico simulations (molecular dynamics simulation and normal-mode analyses) allowed us to evaluate regions that contain potential receptor binding sites in each isoform. The analyses demonstrate that the complexes between the isoforms and IL-10R1 present different types of molecular interactions and consequently different affinities and stabilities. The knowledge about structure and expression of specific viral IL-10 isoforms has implications for understanding of their properties and role in HCMV immune evasion and pathogenesis.