bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimated prevalence rates and risk factors for common mental health problems among Syrian and Afghan refugees in Türkiye
Authors: Kurt Gulsah , Ventevogel Peter , Ekhtiari Maryam , Ilkkursun Zeynep , Erşahin Merve , Akbiyik Nuriye , Acarturk Ceren
Published: September 2022

Background

Türkiye hosts 4 million refugees and asylum seekers, with Syrians and Afghans being among the largest refugee groups in country. There are limited comparative data on the conflict- and displacement-related experiences of these groups and the relation with mental health status.

Aims

To assess the mental health status of Syrians and Afghans in Türkiye, identify risk factors and explore to what extent differences in mental health conditions are related to potentially traumatic events and post-displacement stressors.

Method

Two parallel online survey studies were conducted between April and June 2021 among 798 Syrians and 785 Afghans in Türkiye. Data were collected on sociodemographic characteristics, traumatic events (Harvard Trauma Questionnaire), post-displacement stressors (Post-Migration Living Difficulties Checklist), symptoms of depression and anxiety (Hopkins Symptoms Checklist-25) and post-traumatic stress disorder (PTSD) (Post-Traumatic Stress Disorder Checklist for DSM-5, short form).

Results

For Syrian and Afghan participants respectively, estimated prevalence rates were: 41.1% and 50.3% for depression; 39.6% and 41% for anxiety; and 41.6% and 46.5% for PTSD. In both groups, significant predictors were female gender, exposure to potentially traumatic events, and structural and socioeconomic post-displacement stressors. Additional risk factors were older age for Afghans and higher education for Syrians.

Conclusions

Self-reported symptoms of common mental health problems are highly prevalent among Syrian and Afghan refugees and associated with a wide range of risk factors. After controlling for conflict- and displacement-related experiences, Afghans reported higher anxiety symptoms than Syrians, which is likely related to their legal status in Türkiye.
Association Between DPP4 Inhibitor Use and the Incidence of Cirrhosis, ESRD, and Some Cancers in Patients With Diabetes
Authors: Na Yewon , Kim Soo Wan , Park Ie Byung , Choi Soo Jung , Nam Seungyoon , Jung Jaehun , Lee Dae Ho
Published: September 2022

Context

There are relatively few data on noncardiovascular (non-CV) long-term clinical outcomes of dipeptidyl peptidase 4 inhibitor (DPP4i) treatment.

Objective

We aimed to evaluate some non-CV effects of DPP4is in patients with diabetes.

Methods

Based on data from the National Health Insurance Service database in Korea (2007-2018), we conducted 3 pairwise comparisons of metformin-combined antidiabetic therapies in adult patients with diabetes: DPP4is vs (1) all other oral antidiabetic agents, (2) sulfonylureas/glinides, and (3) thiazolidinediones (TZDs). Major outcomes were liver cirrhosis, end-stage renal disease (ESRD), and cancers in the liver, kidney, and pancreas. Adjusted hazard ratios (HRs) and 95% CIs for the outcomes were estimated using an adjusted Cox model.

Results

Of the 747 124 patients included, 628 217 had received DPP4i therapy for a mean duration of 33.8 ± 25.0 months. Compared with TZD therapy, DPP4i therapy was associated with higher adjusted HRs [95% CIs] for liver cirrhosis (1.267 [1.108-1.449]), ESRD (1.596 [1.139-2.236]), liver cancer (1.117 [1.011-1.235]), and pancreatic cancer (1.158 [1.040-1.290]). Furthermore, apart from liver cirrhosis, a higher risk of each of these outcomes was associated with DPP4i use than with non-DPP4i use. The higher adjusted HRs associated with DPP4i use further increased when patients with long-term exposure to DPP4is were analyzed.

Conclusion

DPP4i therapy in patients with diabetes was associated with a higher risk of liver cirrhosis and cancer, ESRD, and pancreatic cancer than TZD therapy and, except for liver cirrhosis, the risk of these outcomes was greater with DPP4i treatment than with non-DPP4i treatment.
Probability of Pregnancy With Mono vs Multiple Folliculogenesis in Women With Unexplained Infertility
Authors: Plowden Torie C , Mumford Sunni L , Wild Robert A , Cedars Marcelle I , Steiner Anne Z , Franasiak Jason M , Diamond Michael P , Santoro Nanette
Published: September 2022

Context

Ovarian stimulation (OS) increases pregnancy rates but can cause multiple folliculogenesis and multiple pregnancy.

Objective

To determine whether the probability of pregnancy differs in OS cycles with mono- vs multifolliculogenesis in women with unexplained infertility (UI).

Design

Secondary analysis of a multicenter, randomized controlled trial: Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation with 3 treatment arms: gonadotropins, clomiphene, or letrozole, combined with intrauterine insemination. Women were categorized as having either 1 or ≥ 2 mature follicles (≥ 16 mm). Relative risk (RR) and 95% CIs for clinical pregnancy and live birth by number of follicles were estimated using generalized linear models adjusted for age, body mass index, years of infertility, and history of prior live birth.

Setting

12 US-based clinical sites.

Participants

Normally cycling women aged 18 to 40 years with a normal uterine cavity and at least 1 patent fallopian tube. Male partners with ≥ 5 million total motile sperm.

Interventions

Gonadotropins, clomiphene, or letrozole with insemination

Main Outcome Measure(s)

Clinical pregnancy rates (CPR) and live birth rates (LBR).

Results

A single mature follicle > 16 mm resulted in lower CPR (RR, 0.70; 95% CI, 0.54-0.90) and LBR (RR, 0.67; 95% CI, 0.51-0.89) compared with ≥ 2 mature follicles. When stratified by treatment modality, no association of follicle number with CPR or LBR was observed for letrozole or clomiphene, but women using gonadotropins had lower CPR and LBR with monofolliculogenesis.

Conclusion

In couples undergoing gonadotropin treatment for UI, monofolliculogenesis following OS is related to a lower rate of live birth.
Hazard Versus Linear Probability Difference-in-Differences Estimators for Demographic Processes
Authors: Wu Lawrence L. , Wen Fangqi
Published: September 2022

This study examines the properties of the linear probability difference-in-differences estimator when the data are in fact generated by a single-decrement, continuous-time hazard process. We focus on the textbook case of two groups and two periods in which the control and treatment groups are observed before and after treatment. We provide formal derivations and illustrate matters concretely by reexamining economic studies that have relied on the linear probability difference-in-differences estimator when attempting to obtain estimates of the causal effect of unilateral and no-fault divorce. In particular, we show that the increasing then decreasing pattern of effects found by Wolfers (2006) can be generated by a time-invariant effect of treatment in a proportional hazard setting. We conclude that often implicit assumptions about how the data are generated are an important and necessary component of causal identification.
The influence of substrate size upon pulling and gripping forces in parrots (Psittaciformes: Agapornis roseicollis)
Authors: Dickinson Edwin , Young Melody W. , Kim Charles J. , Hadjiargyrou Michael , Granatosky Michael C.
Published: September 2022

The ability to securely grasp substrates of variable diameter is critical to arboreal animals. Arboreal specialists have emerged across several vertebrate lineages – including mammals, lizards and amphibians – and several attempts have been made to quantify their grasping performance, by measuring either gripping (i.e. forces generated about an object or substrate enclosed within the digits) or pulling (i.e. the ability to resist being removed from a substrate) forces. In this study, we present data on both pulling and gripping performance across a range of substrate diameters (0.5–17.5 mm) within a model parrot species (Agapornis roseicollis). Parrots represent an ancient arboreal lineage, allowing us to compare their abilities with those of arboreal specialists within other tetrapod groups. Data were collected using 3D-printed perches of variable diameter, and forces were registered using either an AMTI low-load force plate (grip force) or a Harvard Apparatus portable strength tester (pull force). Gripping forces peaked at a 5 mm diameter perch, while pulling forces were greatest at a 2.5 mm diameter. All forces strongly diminished above 10 mm size, suggesting grip force is optimized when utilizing small perches, a finding which corresponds to observational studies of preferential perching habits among free-ranging parrots. Relative grasping performance (adjusted for body size) in parrots is roughly equivalent to that of other arboreal specialists from other tetrapod lineages, but low when compared with that of raptorial birds that utilize their feet during aerial prey capture. Further taxonomic sampling is encouraged to contextualize how grasping performance varies in an adaptive evolutionary context.
The daunting task of modifying ribosomal RNA
Authors: Meier U. Thomas
Published: September 2022

One of the most basic tasks of every cell is the synthesis of ribosomes, yet the process is so complex that we are only beginning to comprehend it. In human cells, the final product contains four RNAs and 79 proteins forming a large ribonucleoprotein, the ribosome. About twice as many factors are involved in assembly of these protein synthesizing machines. Additionally, some 200 small nucleolar ribonucleoproteins (snoRNPs) function in the modification of pre-ribosomal RNA (pre-rRNA) at a similar number of ribonucleotides. Modification is essential for proper function and biogenesis of ribosomes (Decatur and Fournier 2002; Sloan et al. 2016). While abrogation of individual modifications has little to no measurable effects, removal of a combination of modifications or of all causes severe to lethal effects. Modifications mostly cluster around the functional centers of the ribosome and some modifications are important for ribosome assembly. The subject of this perspective is to raise awareness to how modification at so many sites can be achieved while the pre-rRNA is being processed, folded and re-folded, and assembled with ribosomal proteins to yield the pre-ribosomal subunits in the nucleolus (Baßler and Hurt 2019). This is not a comprehensive review but a simplification of complex issues providing access to the general reader.
Koryfeusze śląskiej mediewistyki w XIX w. w służbie idei i narodu. U źródeł koncepcji europeizacji Śląska w średniowieczu (rekonesans)
Authors: Rosik Stanisław
Published: September 2022

CORYPHAEUS OF SILESIAN MEDIEVAL STUDIES IN THE 19TH CENTURY IN THE SERVICE OF THE IDEA AND THE NATION AT THE SOURCES OF THE CONCEPT OF EUROPEANIZATION OF SILESIA IN THE MIDDLE AGES (RECONNAISSANCE) The article describes the achievements of Silesian historiography, which laid the foundation for the interpretation of the history of the region in the Middle Ages. The focus was on presenting research on the long 13th century. It was a century particularly important for the later history of Silesia due to the German colonization. The historiography of Silesia in the 18th century was generally described. However, the focus was on historians active in the 19th century. The article presents research achievements of Karl Adolf Menzel (1784-1855), Gustav Gottlieb Büsching (1783-1829), Gustav Adolf Harald Stenzel (1792-1854), Colmar Grünhagen (1828-1911). The achievements of Grünhagen, who published source materials for the history of Silesia in Scriptores rerum Silesiacarum and Codex diplomaticus Silesiae, published since 1870, and in Regesta episcopatus Vratislaviensis (1864), were especially emphasized. In the years 1884-1886 he published the very important Geschichte Schlesiens.
Żagańska kolekcja listów i autografów w Rosyjskim Państwowym Archiwum Akt Dawnych w Moskwie
Authors: Ciesielski Tomasz
Published: September 2022

THE ŻAGAŃ COLLECTION OF LETTERS AND AUTOGRAPHS IN THE RUSSIAN STATE ARCHIVES OF HISTORICAL RECORDS IN MOSCOW The Russian State Archives of Historical Records in Moscow (РÝоссийский государственный ар- хив древних актов) contains a group No. 1587, which the institution’s resource list calls ‘Collection of Autographs Gathered by Princes Żagań.’ The article describes the history of the library of the dukes of Żagań in the 19th century, including the creation of a collection of manuscripts. This collection is of a particular importance as a testimony to the final years of the Duchy of Courland and Semigalia and the extensive family ties of the princes of Żagań. The collection also includes autographs of important historical figures in Europe, sources concerning the Thirty Years’ War in Silesia, and relations with the inhabitants of the Republic of Poland, including King Stanisław August Poniatowski. In the second part of the article, the content of the correspondence of Princess Anna Karolina Biron with the Polish king and its context were reported.
Pushing Yourself Harder: The Effects of Mobile Touch Modes on Users’ Self-Regulation
Authors: Liu Yang (Alison) , Jiang Zhenhui (Jack) , Choi Ben C. F.
Published: September 2022

Mobile health interventions are widely used to facilitate individuals’ management of their health behavior. A notable issue is that health interventions with obvious persuasive intent may cause negligence and reactance. In this study, we propose a subtle but powerful way to bolster self-regulation in maintaining healthy behavior by leveraging embodied interaction design. Our study shows that bodily actions in interacting with digital devices can trigger thoughts about prior associated experiences and, thus, be strategically designed to affect individuals’ judgments, decisions, and behavior. Specifically, in three experiments, we find that firmly pressing a touchscreen during mobile interaction (as compared with gently tapping a touchscreen) can activate users’ approach motivation and, thus, induce their preference for a healthy over a tasty beverage, lead to more challenging exercise goals and more exercise, and reduce personal hygiene lapses after receiving hygiene education. Hence, designers of digital health products may consider designing interaction with pressing gestures to facilitate users’ self-regulation and attainment of health-related goals. Policymakers can also encourage the adoption of relevant app designs to improve citizens’ health wellbeing.
Fully Polynomial-Time Approximation Schemes for Fair Rent Division
Authors: Arunachaleswaran Eshwar Ram , Barman Siddharth , Rathi Nidhi
Published: September 2022

We study the problem of fair rent division that entails splitting the rent and allocating the rooms of an apartment among agents in a fair manner (i.e., under the imposed rents, no agent has a strictly stronger preference for any other agent’s room). The utility functions specify the cardinal preferences of the agents for the rooms for every possible room rent. Although envy-free solutions are guaranteed to exist under reasonably general utility functions, efficient algorithms for finding them were known only for quasilinear utilities. This work addresses this notable gap and develops a fully polynomial-time approximation scheme for fair rent division with minimal assumptions on the utility functions. Envy-free solutions correspond to equilibria of a two-sided matching market with monetary transfers; hence, this work also provides efficient algorithms for finding approximate equilibria in such markets. We complement the algorithmic results by proving that the fair rent division problem lies in the intersection of the complexity classes polynomial parity arguments on directed graphs and polynomial local search.
Assessment of Water Quality of Kulik River of Raiganj with Reference to Physicochemical Characteristics and Potability
Authors: Roy Vivek , Saha Barnan Kumar , Saha Jayanti , Pal Ayon
Published: September 2022

This study involves the assessment of physicochemical and microbiological parameters evaluated from nine sites along the stretch of the Kulik river for one year (during January–December 2020), in and around the town of Raiganj in Uttar Dinajpur district of West Bengal, India. The study was carried out to determine whether the river water can be used for drinking, domestic or household and recreation purposes. The parameters such as water temperature, pH, free carbon dioxide, dissolved oxygen, total alkalinity, total hardness, chlorides and total coliform count were analyzed using standard protocols. Significant differences were observed in the parameters both temporally and spatially. Total coliform count indicated the river water has high faecal contamination. The present study depicts the quality of the river and indicates that the water is non-potable. The result implies that the river needs continuous monitoring and treatment to maintain its aesthetic and hygienic value and to ensure its conservation for the future generation.
Flood Hazard Vulnerability Assessment by using Geo Spatial Techniques: Krishna and Guntur Districts, Andhra Pradesh
Authors: Prasad B. , Rao P. Brahmaji , Ramamohanarao P. , Sarathkumar S.
Published: September 2022

The study on flood hazard vulnerability assessment of Guntur and Krishna district in Andhra Pradesh. The present study has attempted by using the historical flood inundation data (2000-2020) and obtain flood hazard zones using multi temporal data sets through remote sensing and GIS. The Krishna floods of 2020 have been used as a case study for ground-truthing verification. Flood Hazard Zonation (FHZ)mapwas generated after getting flood hazard layers and integrating them in the GIS environment using a multi-criteria overlay analysis approach.The flood hazard zones has been classified into low, moderate and highbased on frequency of floods, their spatial extent and number of flooding events occurred in the study area during last 21 years. About414 villages are identified as low hazard category, 58 villages fall in Moderate and 35 villages are in High flood hazard category in the study area. Minimizing Disaster Risk Reduction, the Government particularly the disaster management authorities shall integrate long-term mitigation strategies based on risk assessment and geospatial technologies for sustainable development and planning.
COMUNICAÇÃO E DISCURSO POLÍTICO EM TEMPOS DE CRISE: o uso do Twitter por presidentes sul-americanos na pandemia da Covid-19
Authors: Carreiro Rodrigo , Mesquita Pedro , Silva Rodrigo
Published: September 2022

O presente artigo busca compreender de que forma o Twitter foi utilizado por presidentes sul-americanos durante a pandemia da Covid-19, já que os agentes políticos ocupam uma centralidade na comunicação política, principalmente nesses momentos de crise. Foram coletados tweets no período de dois meses. Os líderes selecionados foram: Jair Bolsonaro (Brasil), Sebastian Piñera (Chile), Alberto Fernández (Argentina) e Nicolás Maduro (Venezuela). O Twitter foi usado com intensidade por todos eles, que focaram nas medidas tomadas para conter o avanço do Coronavírus e na rotina de trabalho relacionada ao tema.
Inequalities in receipt of long-term care services by disabled or older people and co-resident carer dyads in England
Authors: Brimblecombe Nicola
Published: September 2022

Internationally, many care-recipients and unpaid carers are not receiving the services they need to live full and independent lives, representing substantial social injustice. We explored unmet need and inequalities in receipt of long-term care services in England. Methods comprised in-depth interviews and secondary analysis of UK Household Longitudinal Study dyad data from 2017/2019. We found widespread unmet need for services overall and inequalities by sex, ethnicity, income, and area deprivation. Aspects of long-term care policy, service delivery, people’s material resources, and constrained and unconstrained choice all played a role.
Is Turkey a Western nation? How the Turkish political elite aimed to appeal to the US political elite during the Afghan conflict
Authors: Basbugoglu Tarik
Published: September 2022

Using discourse analysis as its methodology, this article demonstrates how the Turkish political elite sought to play a ‘Western nation role’ towards Afghanistan in order to appeal indirectly to the US political elite. In that sense, this article underlines how, under coalition (1999–2002) and the Justice and Development Party (2002–) rule, the Turkish governments used security and humanitarian narratives to underscore Turkey’s contributions to Western security after the 11 September 2001 attacks. Continuing on from those narratives, the article explains how a non-Western Muslim country could consider fellow Muslim nations as ‘others’ in order to present itself as a Western actor. This document also details how queer international relations theory and securitisation theory explain the Turkish elite’s decision-making during the North Atlantic Treaty Organization’s presence in Afghanistan over the last two decades. To that end, this article highlights how the Justice and Development Party government continued the pro-Western narratives of its predecessor coalition government, which decided to send Turkish military forces into Afghanistan in order to appeal to the US political elite.
Abortion rights and Roe v Wade: implications for social work – voices from the social work academy
Authors: Lavalette Michael , Beddoe Liz , Horgan Goretti , Sewpaul Vishanthie
Published: September 2022

This paper draws together the work of three leading social work academics to look at the question of abortion and a woman’s right to chose in the context of the recent Roe V Wade reversal in the United States.
What if we decenter consumption and human in the study of consumption and sustainability? A commentary on ‘Care and consumption’ by Laurence Godin
Authors: Sato Chizu
Published: September 2022

This is a commentary on ‘Care and consumption’ (Godin, 2022). I offer my commentary to push some of the author’s points a bit further.
Application of 3D reconstruction technology based on an improved MC algorithm in a shotcreting robot
Authors: Ouyang Qi , Lin Yanhua , Zhang Xinglan , Fan Yuexin , Yang Weijing , Huang Tao
Published: September 2022

A shotcreting robot needs to reconstruct the arch surface in three dimensions (3D) during the process of spraying a tunnel. To solve this problem, we propose an improved marching cube (MC) reconstruction method based on a point cloud splice and normal re-orient. First, we use the explosion-proof LIDAR to acquire the point cloud data of the tunnel arch, followed by the use of the iterative closest point algorithm, a PassThrough filter, and a StatisticalOutlierRemoval filter for point cloud splicing, data segmentation, and simplification, respectively. In order to improve the reconstruction accuracy, we adjusted the estimated point cloud normal for normal consistency and obtained the geometric features of the complex point cloud surface. Furthermore, combined with the improved MC algorithm, the 3D reconstruction of the tunnel arch is realized. The experimental results show that the proposed method can reconstruct the 3D model of the tunnel arch surface quickly and accurately, which lays a foundation for further research on a trajectory plan, spraying status monitors, and control strategies.
AR/VR light engines: perspectives and challenges
Authors: Hsiang En-Lin , Yang Zhiyong , Yang Qian , Lai Po-Cheng , Lin Chih-Lung , Wu Shin-Tson
Published: September 2022

Augmented reality (AR) and virtual reality (VR) have the potential to
revolutionize the interface between our physical and digital worlds.
Recent advances in digital processing, data transmission, optics, and
display technologies offer new opportunities for ubiquitous AR/VR
applications. The foundation of this revolution is based on AR/VR
display systems with high image fidelity, compact formfactor, and high
optical efficiency. In this review paper, we start by analyzing the
human vision system and the architectures of AR/VR display systems and
then manifest the main requirements for the light engines. Next, the
working principles of six display light engines, namely transmissive
liquid crystal display, reflective liquid-crystal-on-silicon
microdisplay, digital light processing microdisplay, micro
light-emitting-diode microdisplay, organic light-emitting-diode
microdisplay, and laser beam scanning displays, are introduced.
According to the characteristics of these light engines, the
perspectives and challenges of each display technology are analyzed
through five performance metrics, namely resolution density, response
time, efficiency/brightness/lifetime, dynamic range, and compactness.
Finally, potential solutions to overcoming these challenges are
discussed.
Narrowband metamaterial absorbers based on interlaced T-shaped all-dielectric resonators for sensing application
Authors: Fan Yi , Yang Rongcao , Li Zhaohua , Zhao Yijia , Tian Jinping , Zhang Wenmei
Published: September 2022

In this paper, a narrowband metamaterial absorber and its complementary structure absorber are proposed, which can be used for refractive index sensing in the terahertz (THz) band. The proposed two absorbers are composed of complementary rotating interlaced T-shaped all-dielectric resonators located on gold plates. It is demonstrated that the interlaced T-shaped absorber has a narrow single absorption peak with absorptivity of 99.4% at 2.987 THz; its full width at half maximum (FWHM) is 0.0219 THz, and the relative bandwidth is 0.73%. The complementary absorber has two narrow absorption peaks at 3.171 THz and 3.409 THz with absorptivity of 99.3% and 99.8%, corresponding FWHMs of 0.0133 THz and 0.0074 THz, and relative bandwidths of 0.42% and 0.22%, respectively. Based on the narrowband absorption characteristics of the absorbers, the sensing applications for different refractive indices of analyte layers are studied. The sensing sensitivity of the two absorbers can reach 1030 GHz/RIU and 3190 GHz/RIU, respectively. The proposed absorbers are promising in the fields of electromagnetic detection, imaging, and sensing.
Advanced nonlinearity equalizer with TC-NL-MLSE for transmitting beyond 200-Gb/s PAM-8 in IM/DD systems
Authors: Zhou Jiahao , Zhang Jing , Zhao Xue , Jin Taowei , Hu Shaohua , Lin Hong , Zhenming Yu , Zhang Qianwu , Xu Bo , Qiu Kun
Published: September 2022

The severe band-limited effect resulted from the low-cost optical transceiver increases the channel memory length and the number of taps of the equalizers. Besides, the interaction of fiber dispersion and square-law detection introduce nonlinear distortions in intensity modulation and direct-detection (IM/DD) transmission systems. The serious band-limited effect and nonlinear distortions degrade the transmission performance and bring challenges to current equalizers for low-complexity implementation. In this paper, we propose a trellis-compression nonlinear maximum likelihood sequence estimation (TC-NL-MLSE) algorithm to compensate the linear and nonlinear distortions with lower complexity. In the TC-NL-MLSE, we introduce a polynomial nonlinear filter (PNLF) to partly compensate both the linear distortions and nonlinear distortions. Then, we establish a look-up-table (LUT) to calculate the nonlinear branch metric (BM). To simplify the calculation, two or three levels with the highest probabilities are selected according to decision thresholds for each symbol to compress the state-trellis graph (STG). This significantly reduces computational complexity on BM calculations especially for high-order modulations. We conduct experiments to transmit beyond the 200-Gb/s PAM-8 signal over 2-km standard single mode fiber (SSMF) at C-band. The TC-NL-MLSE outperforms the reduced-state MLSE with PNLF, and can reach the 7%-overhead hard-decision forward error correction threshold. Moreover, the TC-NL-MLSE reduces the complexity by 97% compared with standard LUT-MLSE, limiting the multipliers around 100 at the expense of only 0.2-dB receiver sensitivity penalty.
Second harmonic generation under doubly resonant lattice plasmon excitation
Authors: Beer Sebastian , Gour Jeetendra , Alberucci Alessandro , David Christin , Nolte Stefan , Zeitner Uwe D.
Published: September 2022

Second harmonic generation is enhanced at the surface lattice resonance in plasmonic nanoparticle arrays. We carried out a parametric investigation on two-dimensional lattices composed of gold nanobars where the centrosymmetry is broken at oblique incidence. We study the influence of the periodicity, the incidence angle and the direction of the linear input polarization on the second harmonic generation. Excitation of the surface lattice resonance either at the fundamental or second harmonic wavelength, achieved by varying the incidence angle, enhance the conversion efficiency. As a special case, we demonstrate that both the wavelengths can be simultaneously in resonance for a specific period of the lattice. In this double resonant case, maximum second harmonic power is achieved.
Numerical modeling for the characteristics study of a focusing ultrashort spatiotemporal optical vortex
Authors: Rui Guanghao , Yang Bin , Ying Xinyuan , Gu Bing , Cui Yiping , Zhan Qiwen
Published: September 2022

Spatiotemporal (ST) wave packet carrying pure transverse orbital angular moment (OAM) with subwavelength spatial size has attracted increasing attentions in recent years, which can be obtained by tightly focusing a linear superposition of ST vortices with different topological charges. In this work, numerical models are proposed to explore the impact of the pulse width of the ST vortex on the characteristics of its focal field. We demonstrate that the rigorous model for calculating the focused ST wave packet is essential for ultrashort optical pulse, while the simplified model has the advantage of high efficiency but can only provide credible results when the pulse width of the illumination is long enough. Specifically, when the pulse width decreases from 100 fs to 5 fs, the accuracy of the simplified model would decrease significantly from 99% to 65.5%. In addition, it is found that the pulse duration would still lead to the collapse of transverse OAM structure near the focus of a high numerical aperture lens, even though the ST astigmatism has already been corrected. To analyze the physical mechanism behind this distortion, Levenberg-Marquardt algorithm is adopted to retrieve the OAM distribution of the focal field. It is shown that the contributions from undesired OAM modes would become nontrivial for short pulse width, leading to the formation of the focal field with hybrid OAM structures. These findings provide insight for the focusing and propagation studies of ultrashort ST wave packets, which could have wide potential applications in microscopy, optical trapping, laser machining, nonlinear light-matter interactions, etc.
Pump tuning of a mid-infrared whispering gallery optical parametric oscillator
Authors: Amiune N. , Zawilski K. T. , Schunemann P. G. , Buse K. , Breunig I.
Published: September 2022

Optical parametric oscillators (OPOs) constitute an important coherent, narrow-linewidth and widely tunable light source with applications in spectroscopy and many other fields. Their realizations based on whispering gallery resonators (WGRs) provide a small footprint and ultra-low thresholds, with demonstrations of tunability typically done via temperature variation. In this work, we show the pump tuning capabilities of a mm-sized WGR mid-infrared OPO made of CdSiP2. By tuning a telecom wavelength diode laser by 16 nm, we generate tunable light from 2708 to 3575 nm. Furthermore, we show controlled tuning in steps of 1 free spectral range (FSR) and the possibility of 12 GHz of continuous tuning. All these features are in good agreement with the theoretical predictions. We conclude that tuning from 2.4 to 4.9 µm is even possible, while still using commercially available near-infrared diode lasers. This work highlights the advantages of pump tuning of WGR OPOs and provides valuable insights for their precise control.
Investigating deep optics model representation in affecting resolved all-in-focus image quality and depth estimation fidelity
Authors: Liu Xin , Li Linpei , Liu Xu , Hao Xiang , Peng Yifan
Published: September 2022

The end-to-end (E2E) optimization of optics and image processing, dubbed deep optics, has renewed the state-of-the-art in various computer vision tasks. However, specifying the proper model representation or parameterization of the optical elements remains elusive. This article comprehensibly investigates three modeling hypotheses of the phase coded-aperture imaging under a representative context of deep optics, joint all-in-focus (AiF) imaging and monocular depth estimation (MDE). Specifically, we analyze the respective trade-off of these models and provide insights into relevant domain-specific requirements, explore the connection between the spatial feature of the point spread function (PSF) and the performance trade-off between the AiF and MDE tasks, and discuss the model sensitivity to possible fabrication errors. This study provides new prospects for future deep optics designs, particularly those aiming for AiF and/or MDE.
Ultra-rapid dual-comb ranging with an extended non-ambiguity range
Authors: Li Ran , Ren Xinyi , Han Bing , Yan Ming , Huang Kun , Liang Yan , Ge Jinman , Zeng Heping
Published: September 2022

In this Letter, we report a scheme that combines time-of-flight (ToF) ranging detection of multi-repetition-rate pulses with asymmetric dual-comb ranging (DCR) measurement. Notably, this combination extends the non-ambiguity range (NAR) of the DCR method without sacrificing its refresh rate and distance precision. With this scheme, we demonstrate absolute distance measurement of moving targets with an NAR of 1.5 km, which is 5× larger than that allowed solely by the DCR method for a given refresh rate at 500 kHz. The ranging precision in a single measurement of 2 µs reaches 10 µm at an effective distance of 571 m (down to 60 nm in 0.1 s). This combined scheme benefits remote sensing of high-speed objects.
Polarization-insensitive 40-channel 100-GHz spacing fold-back planar echelle grating Mux/Demux for photonic integrated wavelength-selective switches
Authors: Wang Yu , Calabretta Nicola
Published: September 2022

We present and numerically demonstrate a novel polarization-insensitive (PI) 40-channel 100-GHz spacing fold-back planar echelle grating (PEG) multiplexer/demultiplexer (Mux/Demux) to realize the compact 1 × 2 crossing-less photonic integrated wavelength-selective switch (PIC-WSS). The PI operation is achieved by a polarization splitter to feed the TE and TM mode into the PEG via two waveguides with different incidental angles so that the two diffracted modes combine at the same output waveguide. By optimizing the design of different input/output angle combinations and sharing the same blazed angle, a single compact PI PEG with fold-back configuration can simultaneously work as twice the Demux and Mux required. The footprint of the single fold-back PI PEG is only ∼40 mm2. The numerical results show that the 40-channel 100-GHz spaced PI fold-back PEG has < 2.4 dB insertion loss, < –60 dB cross talk, zero polarization-dependent wavelength shift (PDWS), 0.3 dB polarization-dependent loss (PDL), < 0.5 dB loss variation and < 0.01 nm wavelength shift between Mux and Demux.
Highly sensitive fiber optic humidity sensor based on polyvinyl alcohol Fabry–Perot
Authors: Khashin Suroor L. , Mohammed Saif A. , Taher Hanan J.
Published: September 2022

In this paper, a fiber optic Fabry–Perot (FP) for relative humidity (RH) sensing is presented. The proposed FP cavity is constructed by splicing a 50-mm length of no-core fiber (NCF) in a single mode fiber. Then, the end side of the NCF is coated with a polyvinyl alcohol (PVA) thin film membrane with different thicknesses (1, 2, 3, 4 µm respectively) to work as a mirror. The fringes pattern of the FP undergoes a spectral shift owing to the alteration in the PVA refractive index with the ambient RH alternative. The highest obtainable sensitivity was observed at thickness of 3 µm, which is about 0.866 nm/RH%. After that, the diameter of the NCF is tuned from 125 to 65 µm using hydrofluoric acid (HF40%) to maximize the evanescent field and thus improved sensitivity to about 0.908 nm/RH% at the diameter of 95 µm for 30% to 90% RH range. The sensor shows good stability, and easy fabricated.
Molecular architecture of the C. elegans centriole
Authors: Woglar Alexander , Pierron Marie , Schneider Fabian Zacharias , Jha Keshav , Busso Coralie , Gönczy Pierre
Published: September 2022

Uncovering organizing principles of organelle assembly is a fundamental pursuit in the life sciences. Caenorhabditis elegans was key in identifying evolutionary conserved components governing assembly of the centriole organelle. However, localizing these components with high precision has been hampered by the minute size of the worm centriole, thus impeding understanding of underlying assembly mechanisms. Here, we used Ultrastructure Expansion coupled with STimulated Emission Depletion (U-Ex-STED) microscopy, as well as electron microscopy (EM) and electron tomography (ET), to decipher the molecular architecture of the worm centriole. Achieving an effective lateral resolution of approximately 14 nm, we localize centriolar and PeriCentriolar Material (PCM) components in a comprehensive manner with utmost spatial precision. We found that all 12 components analysed exhibit a ring-like distribution with distinct diameters and often with a 9-fold radial symmetry. Moreover, we uncovered that the procentriole assembles at a location on the centriole margin where SPD-2 and ZYG-1 also accumulate. Moreover, SAS-6 and SAS-5 were found to be present in the nascent procentriole, with SAS-4 and microtubules recruited thereafter. We registered U-Ex-STED and EM data using the radial array of microtubules, thus allowing us to map each centriolar and PCM protein to a specific ultrastructural compartment. Importantly, we discovered that SAS-6 and SAS-4 exhibit a radial symmetry that is offset relative to microtubules, leading to a chiral centriole ensemble. Furthermore, we established that the centriole is surrounded by a region from which ribosomes are excluded and to which SAS-7 localizes. Overall, our work uncovers the molecular architecture of the C. elegans centriole in unprecedented detail and establishes a comprehensive framework for understanding mechanisms of organelle biogenesis and function.
Demonstration of three-dimensional contact point determination and contour reconstruction during active whisking behavior of an awake rat
Authors: Huet Lucie A. , Emnett Hannah M. , Hartmann Mitra J. Z.
Published: September 2022

The rodent vibrissal (whisker) system has been studied for decades as a model of active touch sensing. There are no sensors along the length of a whisker; all sensing occurs at the whisker base. Therefore, a large open question in many neuroscience studies is how an animal could estimate the three-dimensional (3D) location at which a whisker makes contact with an object. In the present work we simulated the shape of a real rat whisker to demonstrate the existence of several unique mappings from triplets of mechanical signals at the whisker base to the three-dimensional whisker-object contact point. We then used high speed video to record whisker deflections as an awake rat whisked against a peg, and used the mechanics resulting from those deflections to extract the contact points along the peg surface. These results demonstrate that measurement of specific mechanical triplets at the base of a biological whisker can enable 3D contact point determination during natural whisking behavior. The approach is viable even though the biological whisker has non-ideal, non-planar curvature, and even given the rat’s real-world choices of whisking parameters. Visual intuition for the quality of the approach is provided in a video that shows the contour of the peg gradually emerging during active whisking behavior.
Extracting individual characteristics from population data reveals a negative social effect during honeybee defence
Authors: Petrov Tatjana , Hajnal Matej , Klein Julia , Šafránek David , Nouvian Morgane
Published: September 2022

Honeybees protect their colony against vertebrates by mass stinging and they coordinate their actions during this crucial event thanks to an alarm pheromone carried directly on the stinger, which is therefore released upon stinging. The pheromone then recruits nearby bees so that more and more bees participate in the defence. However, a quantitative understanding of how an individual bee adapts its stinging response during the course of an attack is still a challenge: Typically, only the group behaviour is effectively measurable in experiment; Further, linking the observed group behaviour with individual responses requires a probabilistic model enumerating a combinatorial number of possible group contexts during the defence; Finally, extracting the individual characteristics from group observations requires novel methods for parameter inference.

We first experimentally observed the behaviour of groups of bees confronted with a fake predator inside an arena and quantified their defensive reaction by counting the number of stingers embedded in the dummy at the end of a trial. We propose a biologically plausible model of this phenomenon, which transparently links the choice of each individual bee to sting or not, to its group context at the time of the decision. Then, we propose an efficient method for inferring the parameters of the model from the experimental data. Finally, we use this methodology to investigate the effect of group size on stinging initiation and alarm pheromone recruitment.

Our findings shed light on how the social context influences stinging behaviour, by quantifying how the alarm pheromone concentration level affects the decision of each bee to sting or not in a given group size. We show that recruitment is curbed as group size grows, thus suggesting that the presence of nestmates is integrated as a negative cue by individual bees. Moreover, the unique integration of exact and statistical methods provides a quantitative characterisation of uncertainty associated to each of the inferred parameters.
Optimal control methods for nonlinear parameter estimation in biophysical neuron models
Authors: Kadakia Nirag
Published: September 2022

Functional forms of biophysically-realistic neuron models are constrained by neurobiological and anatomical considerations, such as cell morphologies and the presence of known ion channels. Despite these constraints, neuron models still contain unknown static parameters which must be inferred from experiment. This inference task is most readily cast into the framework of state-space models, which systematically takes into account partial observability and measurement noise. Inferring only dynamical state variables such as membrane voltages is a well-studied problem, and has been approached with a wide range of techniques beginning with the well-known Kalman filter. Inferring both states and fixed parameters, on the other hand, is less straightforward. Here, we develop a method for joint parameter and state inference that combines traditional state space modeling with chaotic synchronization and optimal control. Our methods are tailored particularly to situations with considerable measurement noise, sparse observability, very nonlinear or chaotic dynamics, and highly uninformed priors. We illustrate our approach both in a canonical chaotic model and in a phenomenological neuron model, showing that many unknown parameters can be uncovered reliably and accurately from short and noisy observed time traces. Our method holds promise for estimation in larger-scale systems, given ongoing improvements in calcium reporters and genetically-encoded voltage indicators.
Use of race, ethnicity, and ancestry data in health research
Authors: Lu Clara , Ahmed Rabeeyah , Lamri Amel , Anand Sonia S.
Published: September 2022

Race, ethnicity, and ancestry are common classification variables used in health research. However, there has been no formal agreement on the definitions of these terms, resulting in misuse, confusion, and a lack of clarity surrounding these concepts for researchers and their readers. This article examines past and current understandings of race, ethnicity, and ancestry in research, identifies the distinctions between these terms, examines the reliability of these terms, and provides researchers with guidance on how to use these terms. Although race, ethnicity, and ancestry are often treated synonymously, they should be considered as distinct terms in the context of health research. Researchers should carefully consider which term is most appropriate for their study, define and use the terms consistently, and consider how their classification may be used in future research by others. The classification should be self-reported rather than assigned by an observer wherever possible.
Drug discovery research in Ghana, challenges, current efforts, and the way forward
Authors: Amewu Richard Kwamla , Amoateng Patrick , Arthur Patrick Kobina , Asare Prince , Asiamah Isaac , Boamah Daniel , Darko Otchere Isaac , Dzidzor Amengor Cedric , Ekuadzi Edmund , Chibale Kelly , Farrell Susan Jane , Appiah-Oppong Regina , Osei-Safo Dorcas , David Read Kevin , Hugh Gilbert Ian , Yeboah-Manu Dorothy
Published: September 2022

We have a long-term vision to develop drug discovery research capacity within Ghana, to tackle unmet medical needs in Ghana and the wider West African region. However, there are several issues and challenges that need to be overcome to enable this vision, including training, human resource, equipment, infrastructure, procurement, and logistics. We discuss these challenges from the context of Ghana in this review. An important development is the universities and research centres within Ghana working together to address some of these challenges. Therefore, while there is a long way to go to fully accomplish our vision, there are encouraging signs.
Competition among cities for export trade brings diversification: The experience of China’s urban export trade development
Authors: Li Enkang , Ma Yingyi , Wang Yi , Chen Yu , Niu Bo
Published: September 2022

Market competition is considered to have a significant impact on product diversification, but related issues are rarely discussed on a city scale. To analyze the diversification of export commodities and export market of 270 Chinese cities, this study uses data from 2000 to 2017 based on the commodity concentration index, market concentration index, export similarity index, spatial stratified heterogeneity, and the Almon lag model. The study’s findings are: (1) The diversification of exports in most Chinese cities increased, which was higher in more developed cities in the southeast than in less developed ones in the northwest. With time, the degree of commodity and market diversification in some developed southeast Chinese cities (e.g., Shanghai) declined. This indicates the difference in and complexity of the evolution of export development in hundreds of Chinese cities between 2000 and 2017. (2) The export competition between cities became increasingly fierce, which effectively urged most of them to improve their export diversification levels. Facing increasing export competition pressure, 81.11% of the total number of cities will enhance the diversification of export commodities to cope with challenges posed by other cities. But only 56.67% will further expand the export market when the pressure of export competition increases. The biggest contribution of this study is the finding that for most Chinese cities, when export competition from other domestic cities increases, increasing diversification of products becomes a wise choice. However, the influence of competition on the diversification degree of the city’s export market is relatively weak. This study provides not only a new perspective for existing research on urban export trade, but also valuable information for cities to form a more profitable and robust trading system.