bluuebunny/crossref_metadata_2025 huggingface dataset:
What Drives House Price Cycles? International Experience and Policy Issues
Authors: Duca John V. , Muellbauer John , Murphy Anthony
Published: September 2021

The role of real estate during the global financial and economic crisis has prompted efforts to better incorporate housing and financial channels into macro models, improve housing models, develop macroprudential tools, and reform the financial system. This article provides an overview of major, recent contributions to the literature in relation to earlier research on what drives housing prices and how they affect economic activity. Particularly emphasized are studies, both theoretical and more strongly evidence-based, that connect housing markets with credit markets, house price expectations, financial stability, and the wider economy. The literature reveals much diversity in the international and regional behavior of house prices and the need to improve data tracking key housing supply and demand influences. Also reviewed are studies examining how monetary, macroprudential, and other policies affect house prices and access to housing. This survey is designed to help readers navigate the plethora of recent studies and understand the unsettled issues and avenues for further research. The findings should be of interest to policy makers concerned with financial stability as well as those dealing with the role of housing in the wider economy (JEL E32, E44, E63, G01, G21, R31).
Prior elicitation of the efficacy and tolerability of Methotrexate and Mycophenolate Mofetil in Juvenile Localised Scleroderma
Authors: Desai Yasin , Jaki Thomas , Beresford Michael W , Burnett Thomas , Eleftheriou Despina , Jacobe Heidi , Leone Valentina , Li Suzanne , Mozgunov Pavel , Ramanan Athimalaipet V , Torok Kathryn S , Anderson Marina E , Anton Jordi , Avcin Tadej , Felton Jessie , Foeldvari Ivan , Laguda Bisola , McErlane Flora , Shaw Lindsay , Zulian Francesco , Pain Clare E
Published: September 2021

Background Evidence is lacking for safe and effective treatments for juvenile localised scleroderma (JLS). Methotrexate (MTX) is commonly used first line and mycophenolate mofetil (MMF) second line, despite a limited evidence base. A head to head trial of these two medications would provide data on relative efficacy and tolerability. However, a frequentist approach is difficult to deliver in JLS, because of the numbers needed to sufficiently power a trial. A Bayesian approach could be considered.

Methods An international consensus meeting was convened including an elicitation exercise where opinion was sought on the relative efficacy and tolerability of MTX compared to MMF to produce prior distributions for a future Bayesian trial. Secondary aims were to achieve consensus agreement on critical aspects of a future trial.

Results An international group of 12 clinical experts participated. Opinion suggested superior efficacy and tolerability of MMF compared to MTX; where most likely value of efficacy of MMF was 0.70 (95% confidence interval (CI) 0.34-0.90) and of MTX was 0.68 (95% CI 0.41-0.8). The most likely value of tolerability of MMF was 0.77 (95% CI 0.3-0.94) and of MTX was 0.62 (95% CI 0.32-0.84). The wider CI for MMF highlights that experts were less sure about relative efficacy and tolerability of MMF compared to MTX. Despite using a Bayesian approach, power calculations still produced a total sample size of 240 participants, reflecting the uncertainty amongst experts about the performance of MMF.

Conclusions Key factors have been defined regarding the design of a future Bayesian approach clinical trial including elicitation of prior opinion of the efficacy and tolerability of MTX and MMF in JLS. Combining further efficacy data on MTX and MMF with prior opinion could potentially reduce the pre-trial uncertainty so that, when combined with smaller trial sample sizes a compelling evidence base is available.
Improving the support for XML dynamic updates using a hybridization labeling scheme (ORD-GAP)
Authors: Haw Su-Cheng , Amin Aisyah , Wong Chee-Onn , Subramaniam Samini
Published: September 2021

Background: As the standard for the exchange of data over the World Wide Web, it is important to ensure that the eXtensible Markup Language (XML) database is capable of supporting not only efficient query processing but also capable of enduring frequent data update operations over the dynamic changes of Web content. Most of the existing XML annotation is based on a labeling scheme to identify each hierarchical position of the XML nodes. This computation is costly as any updates will cause the whole XML tree to be re-labelled. This impact can be observed on large datasets. Therefore, a robust labeling scheme that avoids re-labeling is crucial.

Method: Here, we present ORD-GAP (named after Order Gap), a robust and persistent XML labeling scheme that supports dynamic updates. ORD-GAP assigns unique identifiers with gaps in-between XML nodes, which could easily identify the level, Parent-Child (P-C), Ancestor-Descendant (A-D) and sibling relationship. ORD-GAP adopts the OrdPath labeling scheme for any future insertion.

Results: We demonstrate that ORD-GAP is robust enough for dynamic updates, and have implemented it in three use cases: (i) left-most, (ii) in-between and (iii) right-most insertion. Experimental evaluations on DBLP dataset demonstrated that ORD-GAP outperformed existing approaches such as ORDPath and ME Labeling concerning database storage size, data loading time and query retrieval. On average, ORD-GAP has the best storing and query retrieval time.

Conclusion: The main contributions of this paper are: (i) A robust labeling scheme named ORD-GAP that assigns certain gap between each node to support future insertion, and (ii) An efficient mapping scheme, which built upon ORD-GAP labeling scheme to transform XML into RDB effectively.
Exploratory graph analysis of the network data of the Ethereum blockchain
Authors: Yap Timothy Tzen Vun , Ho Ting Fong , Ng Hu , Goh Vik Tor
Published: September 2021

Background: This research uses exploratory graph analysis to analyze the transaction data of the Ethereum network. This is achieved through network visualization and mathematical and statistical modelling of the network data.

Methods: The dataset used in this study was extracted from the Ethereum in the BigQuery public dataset, specifically selected transactions in July 2019. The transactions were firstly modelled as network graphs and then visualized using the Kamada-Kawai and force-directed graphs layouts. Further modelling was explored with classical random graph and network block, with emphasis on network cohesion, hierarchical clustering and community membership.

Results: Looking at the network visualization and hierarchical clustering of the data, the network shows 170 clusters, the largest having 135 members. Through random graph modelling the optimum number of clusters is shown to be 95. Referring to the generated dendrograms, notable large transactions center around the DRINK token, the Maximine Exchange, the Upbit2 Exchange and the IDEX Exchange, identified through public disclosure of their Ethereum addresses. The network graphs tend to go towards the DRINK smart contract and the Maximine Exchange, indicating deposit actions, while it is the opposite for the IDEX Exchange. Further analysis also shows a different number of communities than the expected number. Falling short of the expected 170 clusters, the model is not able to capture additional mechanism that may be present at the density and social interaction distribution level of the network. On the other hand, network block modelling shows only four major clusters out of the 170 expected clusters, an indication that the model is not able to capture the network sufficiently.

Conclusions: The study was able to capture and model the interconnectedness of the system with its notion of elements, in this case, the transactions on the network.
Assessing the generalisability of a multicentre qualitative dementia research: the experience and challenges faced by the MinD project in Europe
Authors: Lim Jennifer N.W. , Niedderer Kristina , Tournier Isabelle , Almeida Rosa , Harrison Dew , Holthoff-Detto Vjera , Ludden Geke , van Rompay Thomas , van der Voort Mascha , Galansinska Aleksandra , Smith Tina , Lasada Raquel L. , Bueno Yolanda A. , Druschke Diana , Ziebuhr Berit , Zanasi Michele
Published: September 2021

Background: Generalisation of findings is an important aspect of research and essential for evidence-based practice. While generalisation is common in quantitative research, there is a lack of generalisability in qualitative research. This paper presents the experience and challenges faced by the Designing for People with Dementia (MinD) project in meeting the requirements to strengthen the generalisation of findings on the lived experience of people living with dementia and their engagement to co-create designs to empower their everyday living.  

Methods: Polit and Beck (2010)’s strategies to generalise qualitative findings were applied: (1) replication in sampling; (2) replication of studies; (3) meta-synthesis of findings; (4) reflexivity and conceptualization; (5) immersion with the data; and (6) thick description.

Results: While it is possible to increase the generabilisabilty of qualitative evidence through the replication of the sampling to attain a large, heterogeneous sample in different and multiple contexts and environments; implementation of sound and robust research; conducting in-depth analysis and interpretation collaboratively for emergent themes; and meeting the thick description requirement, there are challenges that the project team faced in implementing some of the Polit and Beck’s strategies because of the condition, namely dementia, that our participants are having. Other challenges faced were: the language and culturaldiversity in the team; diverse  work and organisational procedures; and the inter-disciplinary differences relating to the methods of enquiry, approaches and techniques to conduct research. These challenges will need to be identified and addressed at the start of the project with a strong leadership to ensure a seamless journey to complete the project successfully.Trust between the researchers and participants, and time to build this trust are critical to recruitment and participation in the study; these factors are of utmost important in research involving participants with condition such as dementia.
An update on immunotherapy with PD-1 and PD-L1 blockade
Authors: Koh Sung Ae
Published: September 2021

Cancer is the leading cause of death and is on the rise worldwide. Until 2010, the development of targeted treatment was mainly focused on the growth mechanisms of cancer. Since then, drugs with mechanisms related to tumor immunity, especially immune checkpoint inhibitors, have proven effective, and most pharmaceutical companies are striving to develop related drugs. Programmed cell death-1 and programmed cell death ligand-1 inhibitors have shown great success in various cancer types. They showed durable and sustainable responses and were approved by the U.S. Food and Drug Administration. However, the response to inhibitors showed low percentages of cancer patients; 15% to 20%. Therefore, combination strategies with immunotherapy and conventional treatments were used to overcome the low response rate. Studies on combination therapy have typically reported improvements in the response rate and efficacy in several cancers, including non-small cell lung cancer, small cell lung cancer, breast cancer, and urogenital cancers. The combination of chemotherapy or targeted agents with immunotherapy is one of the leading pathways for cancer treatment.
Leviathan Inc. and Corporate Environmental Engagement
Authors: Hsu Po-Hsuan , Liang Hao , Matos Pedro
Published: September 2021

In a 2010 special report, The Economist magazine termed the resurgence of state-owned, publicly listed enterprises “Leviathan Inc.” and criticized the poor governance and low efficiency of these firms. We compile a new comprehensive data set of state ownership of publicly listed firms in 44 countries over the period of 2004–2017 and show that state-owned enterprises are more responsive to environmental issues. The effect is more pronounced in economies lacking energy security and strong environmental regulation, and among firms with more local operations and higher domestic government ownership. We find a similar effect on corporate social engagement but not on governance quality. These results suggest a different role for “Leviathan Inc.,” especially in dealing with environmental externalities.

This paper was accepted by Colin Mayer, Special Section of Management Science on Business and Climate Change.

Funding: H. Liang acknowledges the DBS Sustainability Fellowship from Singapore Management University. P.-H. Hsu acknowledges the fellowship from the Batten Institute of Darden School of Business of the University of Virginia and the financial support from the E.SUN Academic Award and Ministry of Science and Technology and Ministry of Education in Taiwan [Grants MOST108-2410-H-007-099-MY2, MOST109-2628-H-007-001-MY4, MOST109-2634-F-002-045, MOE109J0321Q2, and MOE109L900202]. P. Matos acknowledges financial support from the Richard A. Mayo Center for Asset Management at the University of Virginia's Darden School of Business.

Supplemental Material: The data files and online appendix are available at https://doi.org/10.1287/mnsc.2021.4064 .
Short-pulse broadband stimulated Raman scattering in carbon disulfide via resonance cascading
Authors: Li Shuang , Wang Ying , Liu Xiaofeng , Sun Chenglin , Fang Wenhui , Men Zhiwei
Published: September 2021

Cascaded stimulated Raman scattering (SRS) of carbon disulfide (

C
S

2

) was investigated by a pulsed Nd:YAG laser with a wavelength of 532 nm. The fourth-order Stokes and second-order anti-Stokes lines were generated when the pump laser energy was about 1.909 mJ in one sample cell (

C

1

) only. However, the same result was obtained in the second sample cell (

C

2

) with a pump energy of 0.883 mJ. At the same time, the fifth-order Stokes line was produced in

C

2

when the pump energy increased to 1.208 mJ, and the coherent radiation wavelength ranged from 498 to 644 nm. The result was attributed to the resonance enhancement effect, where the frequency difference between the pump laser and the Stokes light emitted from the working medium (

C
S

2

) self-matched with the vibrational energy level of

C

=

S

, which resulted in the generation of the cascaded broadband SRS. The anti-Stokes SRS was attributed to four-wave mixing. Simultaneously, the pulse durations of the Stokes and anti-Stokes were compressed to about 380 ps by SRS and laser-induced breakdown. The resonance effect not only reduced the threshold, but it also generated broadband and short-pulse SRS.
Simultaneous measurement of salinity and temperature using a Sagnac interferometer based on concatenated polarization-maintaining fiber tapers
Authors: Yang Chengkun , Zhang Shengqi , Shi Donglei , Wu Yichang , Cao Zihan , Liu Zhengyong
Published: September 2021

A Sagnac loop interferometer based on concatenated polarization-maintaining fiber (PMF) tapers is proposed for simultaneous measurement of seawater salinity and temperature. The influences of the distance between the PMF tapers as well as fiber taper diameter on sensor performance have been investigated. Experimental results indicate that the fabricated sensor with a distance of 3 cm between adjacent fiber tapers possesses the salinity and temperature sensitivities of 0.367 nm/% and

−

0.728

n
m

/

∘

C

, respectively, and the taper waist diameter of 20 µm would help to improve salinity sensitivity in comparison with a sensor of 30 µm in diameter. The proposed Sagnac loop interferometer based on concatenated PMF tapers is expected to find potential applications in the measurement of seawater salinity.
Quantitative and anatomical imaging of dermal angiopathy by noninvasive photoacoustic microscopic biopsy
Authors: Ma Haigang , Cheng Zhongwen , Wang Zhiyang , Qiu Haixia , Shen Tianding , Xing Da , Gu Ying , Yang Sihua
Published: September 2021

The ability to noninvasively acquire the fine structure of deep tissues is highly valuable but remains a challenge. Here, a photoacoustic microscopic biopsy (PAMB) combined switchable spatial-scale optical excitation with single-element depth-resolved acoustic detection mode was developed, which effectively coordinated the spatial resolution and the penetration depth for visualizations of skin delamination and chromophore structures up to reticular dermis depth, with the lateral resolution from 1.5 to 104 μm and the axial resolution from 34 to 57 μm. The PAMB obtained anatomical imaging of the pigment distribution within the epidermis and the vascular patterns of the deep dermal tissue, enabling quantification of morphological abnormalities of angiopathy without the need for exogenous contrast agents. The features of healthy skin and scar skin, and the abnormal alteration of dermal vasculature in port wine stains (PWS) skin were first precisely displayed by PAMB-shown multi-layered imaging. Moreover, the quantitative vascular parameters evaluation of PWS were carried out by the detailed clinical PAMB data on 174 patients, which reveals distinct differences among different skin types. PAMB captured the PWS changes in capillary-loop depth, diameter, and vascular volume, making it possible to perform an objective clinical evaluation on the severity of PWS. All the results demonstrated the PAMB can provide vascular biopsy and new indexes deep into the dermal skin noninvasively, which should be meaningful to timely evaluate the pathological types and treatment response of skin diseases. This opens up a new perspective for label-free and non-invasive biopsies of dermal angiopathy.
Arbitrary polarization and orbital angular momentum generation based on spontaneously broken degeneracy in helically twisted ring-core photonic crystal fibers
Authors: Fujisawa Takeshi , Saitoh Kunimasa
Published: September 2021

Using orbital angular momentum (OAM) as a spatial information channel attracts a lot of attention due to its infinite multiplexing capability. The research on OAM carrying fibers is intensively studied and ring-core fibers are promising candidates for them. At the same time, generating OAM modes in those fibers are also important topic. Here, the evolutions of polarization states including OAM of light in helically twisted ring-core photonic crystal fibers (PCFs) are investigated for generating OAM states. The degeneracy of some of the mode sets is spontaneously broken, and the birefringence cause a geometric phase (GP) in the twisted PCFs while preserving the vectorial nature of the modes. It is demonstrated that an arbitrary polarization and OAM state can be generated by using the GP in uniformly twisted and twisted PCFs with periodical inversion. In the ring-core PCF presented in this paper, the degeneracy of HE31 and EH31 mode sets are broken, and OAM light with the topological charge of 2 and 4 can be generated. The wavelength dependence is very small compared with that of OAM generators based on long-period gratings (LPGs). Furthermore, by properly setting the period of the inversion, OAM light with different topological charges can be simultaneously generated with the same fiber structure. These results indicate that the proposed approach is effective for the generation of OAM modes with the conventional fiber modes.
Polarization-insensitive achromatic metalens based on computational wavefront coding
Authors: Sun Ti , Hu Jingpei , Ma Suodong , Xu Feng , Wang Chinhua
Published: September 2021

Broadband achromatic metalens imaging is of great interest in various applications, such as integrated imaging and augmented/virtual reality display. Current methods of achromatic metalenses mainly rely on the compensation of a linear phase dispersion implemented with complex nanostructures. Here, we propose and experimentally demonstrate a polarization-insensitive achromatic metalens (PIA-ML) based on computational wavefront coding. In this method, simple circular or square nanopillars are individually coded such that the focal depths at wavelengths at both ends of the achromatic bandwidth overlap at the designed focal plane, which removes the limitation of requiring a linear phase dispersion. An optimized PIA-ML that works in the full optical communication band from 1300 to 1700nm was obtained using a particle swarm optimization algorithm. Experimental results show that both focusing and imaging of the fabricated metalens are consistent with theoretical predictions within the broadband wavelength range, which provides a new methodology for ultra-broadband achromatic imaging with simple-shaped nanostructures.
Dynamic coherent diffractive imaging with a physics-driven untrained learning method
Authors: Yang Dongyu , Zhang Junhao , Tao Ye , Lv Wenjin , Lu Shun , Chen Hao , Xu Wenhui , Shi Yishi
Published: September 2021

Reconstruction of a complex field from one single diffraction measurement remains a challenging task among the community of coherent diffraction imaging (CDI). Conventional iterative algorithms are time-consuming and struggle to converge to a feasible solution because of the inherent ambiguities. Recently, deep-learning-based methods have shown considerable success in computational imaging, but they require large amounts of training data that in many cases are difficult to obtain. Here, we introduce a physics-driven untrained learning method, termed Deep CDI, which addresses the above problem and can image a dynamic process with high confidence and fast reconstruction. Without any labeled data for pretraining, the Deep CDI can reconstruct a complex-valued object from a single diffraction pattern by combining a conventional artificial neural network with a real-world physical imaging model. To our knowledge, we are the first to demonstrate that the support region constraint, which is widely used in the iteration-algorithm-based method, can be utilized for loss calculation. The loss calculated from support constraint and free propagation constraint are summed up to optimize the network’s weights. As a proof of principle, numerical simulations and optical experiments on a static sample are carried out to demonstrate the feasibility of our method. We then continuously collect 3600 diffraction patterns and demonstrate that our method can predict the dynamic process with an average reconstruction speed of 228 frames per second (FPS) using only a fraction of the diffraction data to train the weights.
Airy light-sheet Raman imaging
Authors: Subedi N. R. , Yaraghi S. , Jung P. S. , Kukal G. , McDonald A. G. , Christodoulides D. N. , Vasdekis A. E.
Published: September 2021

Light-sheet fluorescence microscopy has greatly improved the speed and overall photostability of optically sectioning cellular and multi-cellular specimens. Similar gains have also been conferred by light-sheet Raman imaging; these schemes, however, rely on diffraction limited Gaussian beams that hinder the uniformity and size of the imaging field-of-view, and, as such, the resulting throughput rates. Here, we demonstrate that a digitally scanned Airy beam increases the Raman imaging throughput rates by more than an order of magnitude than conventional diffraction-limited beams. Overall, this, spectrometer-less, approach enabled 3D imaging of microparticles with high contrast and 1 µm axial resolution at 300 msec integration times per plane and orders of magnitude lower irradiation density than coherent Raman imaging schemes. We detail the apparatus and its performance, as well as its compatibility with fluorescence light-sheet and quantitative-phase imaging towards rapid and low phototoxicity multimodal imaging.
Research on the lossless contention MAC protocol and the performance of an ultraviolet communication network
Authors: Li Cheng , Li Jianhua , Xu Zhiyong , Wang Jingyuan
Published: September 2021

Ultraviolet (UV) communication has been the topic of extensive recent research due to its non-line-of-sight (NLOS) communication, anti-interference, and high confidentiality. Given the lack of the UV Media Access Control (MAC) protocol, this paper proposes a UV lossless contention MAC (UVLLC-MAC) protocol creatively. This MAC protocol is based on the superposition logic of UV power, which effectively reduces the collision loss of multi-node contention access. The basic working mechanism and protocol flow are given in detail, and the network performance is simulated and analyzed mathematically based on a four-node UV network. Comparing with the slotted ALOHA protocol, the simulation results indicate that the network has a higher throughput and lower delay under the protocol. The practical networking of four communication terminals is designed and implemented, and the effectiveness of the new UVLLC-MAC protocol is fully verified.
Sub-pixel high-resolution imaging of high-energy x-rays inspired by sub-wavelength optical imaging
Authors: Bertaux N. , Allain M. , Weizeorick J. , Park J.-S. , Kenesei P. , Shastri S. D. , Almer J. , Highland M. J. , Maddali S. , Hruszkewycz S. O.
Published: September 2021

We have developed and demonstrated an image super-resolution method—XR-UNLOC: X-Ray UNsupervised particle LOCalization—for hard x-rays measured with fast-frame-rate detectors that is an adaptation of the principle of photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM), which enabled biological fluorescence imaging at sub-optical-wavelength scales. We demonstrate the approach on experimental coherent Bragg diffraction data measured with 52 keV x-rays from a nanocrystalline sample. From this sample, we resolve the fine fringe detail of a high-energy x-ray Bragg coherent diffraction pattern to an upsampling factor of 16 of the native pixel pitch of 30 μm of a charge-integrating fastCCD detector. This was accomplished by analysis of individual photon locations in a series of “nearly-dark” instances of the diffraction pattern that each contain only a handful of photons. Central to our approach was the adaptation of the UNLOC photon fitting routine for PALM/STORM to the hard x-ray regime to handle much smaller point spread functions, which required a different statistical test for photon detection and for sub-pixel localization. A comparison to a photon-localization strategy used in the x-ray community (“droplet analysis”) showed that XR-UNLOC provides significant improvement in super-resolution. We also developed a metric by which to estimate the limit of reliable upsampling with XR-UNLOC under a given set of experimental conditions in terms of the signal-to-noise ratio of a photon detection event and the size of the point spread function for guiding future x-ray experiments in many disciplines where detector pixelation limits must be overcome.
Investigation of the tool influence function neighborhood effect in atmospheric pressure plasma processing based on an innovative reverse analysis method
Authors: Ji Peng , Li Duo , Su Xing , Jin Yuan , Qiao Zheng , Wang Bo , Ding Fei
Published: September 2021

Ultra precision optical surfaces can be efficiently manufactured using a computer-controlled optical surfacing (CCOS) process. Based on the chemical reaction, atmospheric pressure plasma processing (APPP) is a promising deterministic CCOS technique and has great application prospect for the figuring processing as well as freeform generation. However, the plasma jet also works as the heat source, leading to the variation of substrate temperature field. This way, the tool influence function (TIF) is continuously changed, which leads to the nonlinear removal characteristic. Especially, it becomes much more complex when considering the neighboring dwell points, because they are thermally interacted. The conventional time-variant TIF model cannot accurately describe the practical TIF changes. In this paper, an innovative reverse analysis method is proposed to derive the practical TIF changes in APPP. First, the special problem of the TIF neighborhood effect is pointed out. The limitation of the conventional TIF model is analyzed with the assisted thermal model. Then, an innovative reverse analysis method is presented to derive the TIF changes from the practical removal, which is demonstrated with the simulation. Further, the proposed method is applied to the analysis of the TIF changes in APPP. To verify its feasibility, the experimental validation is undertaken, which proves its capability of deriving complex TIF changes.
Optical method for simultaneous thickness measurements of two layers with a significant thickness difference
Authors: Bae Jaeseok , Park Jungjae , Ahn Heulbi , Jin Jonghan
Published: September 2021

In this study, an optical method that allows simultaneous thickness measurements of two different layers distributed over a broad thickness range from several tens of nanometers to a few millimeters based on the integration of a spectroscopic reflectometer and a spectral-domain interferometer is proposed. Regarding the optical configuration of the integrated system, various factors, such as the operating spectral band, the measurement beam paths, and the illumination beam type, were considered to match the measurement positions and effectively separate two measurement signals acquired using both measurement techniques. Furthermore, for the thickness measurement algorithm, a model-based analysis method for high-precision substrate thickness measurements in thin-film specimens was designed to minimize the measurement error caused by thin films, and it was confirmed that the error is decreased significantly to less than 8 nm as compared to that when using a Fourier-transform analysis. The ability to undertake simultaneous thickness measurements of both layers using the proposed system was successfully verified on a specimen consisting of silicon dioxide thin film with nominal thicknesses of 100 nm and 150 nm and a 450 µm-thick silicon substrate, resulting in the exact separation between the two layers. From measurement uncertainty evaluation of a thin-film, a substrate in a thin-film specimen, and a single substrate, the uncertainties were estimated to be 0.12 nm for the thin-film, 0.094 µm for the substrate in a thin-film specimen, and 0.076 µm for the substrate. The measurement performance of thicknesses distributed on multi-scale was verified through comparative measurements using standard measurement equipment for several reference samples.
Prototype system for underwater wireless optical communications employing orbital angular momentum multiplexing
Authors: Zhang Jinrun , Fan Fan , Zeng Jinwei , Wang Jian
Published: September 2021

The orbital angular momentum (OAM) multiplexing technology is an essential method to boost underwater wireless optical communication (UWOC) capacity. However, state-of-art UWOC systems are often demonstrated in the laboratory using bulky and high power-consumption instruments, which can be impractical in a realistic environment. In this work, we propose, design and demonstrate a compact and energy-efficient OAM multiplexing UWOC prototype with complete packaging. Indeed, we improve the signal generation, modulation, receiving and processing components by employing the integrated programmable chips. We also employ two geometric phase Q-plate chips as an OAM multiplexer and de-multiplexer, respectively. Owing to the improvement of these components and the optical design, we package the complete UWOC system in two 65cm×35cm×40cm boxes with the power consumption of 20W. Our experiment demonstrates such a completely packaged prototype can support two 625Mbit/s channels (OAM+3, OAM-3) multiplexing in a 6-meter underwater environment with fidelity.
All-optical noncontact phase-domain photoacoustic elastography
Authors: Yang Fen , Chen Zhongjiang , Xing Da
Published: September 2021

Mechanical properties such as elasticity are important indicators of tissue functions that can be used for clinical diagnosis and disease monitoring. However, most current elastography techniques are limited in their ability to distinguish localized microstructural mechanical variations due to employing elastic wave velocity measurement. In addition, their contact-based measurement manner is not favored and may even be prohibited in many applications. In this Letter, we propose all-optical noncontact phase-domain photoacoustic elastography (NPD-PAE), leveraging the temporal response characteristics of laser-induced thermoelastic displacement using optical interferometric detection to calculate the elastic modulus. The all-optical pump-probe method allows the capture of the initial displacement profiles generated at the origin, thus enabling the extraction of in situ elasticity. The feasibility of the method was verified using a tissue-mimicking phantom. The capability to map the mechanical contrast was demonstrated on an ex vivo biological tissue. NPD-PAE opens a new avenue for development of a noncontact elastography technique, holding great potential in the biomedical field and materials science.
Thermally enhanced responsivity in an all-silicon optical power monitor based on defect-mediated absorption
Authors: Huang Qikai , Yu Hui , Zhang Qiang , Li Yan , Chen Weiwei , Wang Yuehai , Yang Jianyi
Published: September 2021

We demonstrate a high responsivity all-silicon in-line optical power monitor by using the thermal effect to enhance the quantum efficiency of defect-mediated absorption at 1550 nm. The doping compensation technique is utilized to increase the density of lattice defects responsible for the sub-bandgap absorption and suppress the detrimental free carrier absorption. The 200-μm-long device presents a propagation loss as low as 2.9 dB/cm. Its responsivity is enhanced from 12.1 mA/W to 112 mA/W at

−
9
  
V

bias by heating the optical absorption region. With this device, we build an optical power monitoring system that operates in the sampling mode. The minimal detectable optical power of the system is below

−
22.8
  
dBm

, while the average power consumption is less than 1 mW at a sampling frequency of 10 Hz. Advantages of this scheme in terms of high responsivity, low insertion loss, and low power consumption lend itself to implement the feedback control of advanced large-scale silicon photonic integrated circuits.
Fluorescent nanodiamonds for characterization of nonlinear microscopy systems
Authors: Žurauskas Mantas , Alex Aneesh , Park Jaena , Hood Steve R. , Boppart Stephen A.
Published: September 2021

Characterizing the performance of fluorescence microscopy and nonlinear imaging systems is an essential step required for imaging system optimization and quality control during longitudinal experiments. Emerging multimodal nonlinear imaging techniques require a new generation of microscopy calibration targets that are not susceptible to bleaching and can provide a contrast across the multiple modalities. Here, we present a nanodiamond-based calibration target for microscopy, designed for facilitating reproducible measurements at the object plane. The target is designed to support day-to-day instrumentation development efforts in microscopy laboratories. The images of a phantom contain information about the imaging performance of a microscopy system across multiple spectral windows and modalities. Since fluorescent nanodiamonds are not prone to bleaching, the proposed imaging target can serve as a standard, shelf-stable sample to provide rapid reference measurements for ensuring consistent performance of microscopy systems in microscopy laboratories and imaging facilities.
Enhanced performance of a fast GaAs-based terahertz modulator via surface passivation
Authors: He Yulian , Wang Yuansheng , Yang Qinghui , Zhang Huaiwu , Wen Qiye
Published: September 2021

Surface-modified semiconductors show enormous potential for opto-terahertz (THz) spatial modulation due to their enhanced modulation depth (MD) along with their inherent broad bandwidth. Taking full advantage of the surface modification, a performance-enhanced, all-optical, fast switchable THz modulator was achieved here based on the surface-passivated GaAs wafer. With a decreased surface recombination rate and prolonged carrier lifetime induced by passivation, S-passivated GaAs was demonstrated as a viable candidate to enhance THz modulation performance in MD, especially at low photodoping levels. Despite a degraded modulation rate owing to the longer carrier lifetime, this passivated GaAs modulator simultaneously realizes a fast modulation at a 69-MHz speed and as high an MD as

∼
94
%

in a spectral wideband of 0.2–1.2 THz. The results demonstrated a new strategy to alleviate the tradeoff between high MD and speed in contrast to bare surfaces or heterogeneous films/unusual geometry on semiconductors including Si, Ge, and GaAs.
Human herpesvirus 8 molecular mimicry of ephrin ligands facilitates cell entry and triggers EphA2 signaling
Authors: Light Taylor P. , Brun Delphine , Guardado-Calvo Pablo , Pederzoli Riccardo , Haouz Ahmed , Neipel Frank , Rey Félix A. , Hristova Kalina , Backovic Marija
Published: September 2021

Human herpesvirus 8 (HHV-8) is an oncogenic virus that enters cells by fusion of the viral and endosomal cellular membranes in a process mediated by viral surface glycoproteins. One of the cellular receptors hijacked by HHV-8 to gain access to cells is the EphA2 tyrosine kinase receptor, and the mechanistic basis of EphA2-mediated viral entry remains unclear. Using X-ray structure analysis, targeted mutagenesis, and binding studies, we here show that the HHV-8 envelope glycoprotein complex H and L (gH/gL) binds with subnanomolar affinity to EphA2 via molecular mimicry of the receptor’s cellular ligands, ephrins (Eph family receptor interacting proteins), revealing a pivotal role for the conserved gH residue E52 and the amino-terminal peptide of gL. Using FSI-FRET and cell contraction assays, we further demonstrate that the gH/gL complex also functionally mimics ephrin ligand by inducing EphA2 receptor association via its dimerization interface, thus triggering receptor signaling for cytoskeleton remodeling. These results now provide novel insight into the entry mechanism of HHV-8, opening avenues for the search of therapeutic agents that could interfere with HHV-8–related diseases.
Personalized brain stimulation for effective neurointervention across participants
Authors: van Bueren Nienke E. R. , Reed Thomas L. , Nguyen Vu , Sheffield James G. , van der Ven Sanne H. G. , Osborne Michael A. , Kroesbergen Evelyn H. , Cohen Kadosh Roi
Published: September 2021

Accumulating evidence from human-based research has highlighted that the prevalent one-size-fits-all approach for neural and behavioral interventions is inefficient. This approach can benefit one individual, but be ineffective or even detrimental for another. Studying the efficacy of the large range of different parameters for different individuals is costly, time-consuming and requires a large sample size that makes such research impractical and hinders effective interventions. Here an active machine learning technique is presented across participants—personalized Bayesian optimization (pBO)—that searches available parameter combinations to optimize an intervention as a function of an individual’s ability. This novel technique was utilized to identify transcranial alternating current stimulation (tACS) frequency and current strength combinations most likely to improve arithmetic performance, based on a subject’s baseline arithmetic abilities. The pBO was performed across all subjects tested, building a model of subject performance, capable of recommending parameters for future subjects based on their baseline arithmetic ability. pBO successfully searches, learns, and recommends parameters for an effective neurointervention as supported by behavioral, simulation, and neural data. The application of pBO in human-based research opens up new avenues for personalized and more effective interventions, as well as discoveries of protocols for treatment and translation to other clinical and non-clinical domains.
Ergodicity-breaking reveals time optimal decision making in humans
Authors: Meder David , Rabe Finn , Morville Tobias , Madsen Kristoffer H. , Koudahl Magnus T. , Dolan Ray J. , Siebner Hartwig R. , Hulme Oliver J.
Published: September 2021

Ergodicity describes an equivalence between the expectation value and the time average of observables. Applied to human behaviour, ergodic theories of decision-making reveal how individuals should tolerate risk in different environments. To optimize wealth over time, agents should adapt their utility function according to the dynamical setting they face. Linear utility is optimal for additive dynamics, whereas logarithmic utility is optimal for multiplicative dynamics. Whether humans approximate time optimal behavior across different dynamics is unknown. Here we compare the effects of additive versus multiplicative gamble dynamics on risky choice. We show that utility functions are modulated by gamble dynamics in ways not explained by prevailing decision theories. Instead, as predicted by time optimality, risk aversion increases under multiplicative dynamics, distributing close to the values that maximize the time average growth of in-game wealth. We suggest that our findings motivate a need for explicitly grounding theories of decision-making on ergodic considerations.
FiCoS: A fine-grained and coarse-grained GPU-powered deterministic simulator for biochemical networks
Authors: Tangherloni Andrea , Nobile Marco S. , Cazzaniga Paolo , Capitoli Giulia , Spolaor Simone , Rundo Leonardo , Mauri Giancarlo , Besozzi Daniela
Published: September 2021

Mathematical models of biochemical networks can largely facilitate the comprehension of the mechanisms at the basis of cellular processes, as well as the formulation of hypotheses that can be tested by means of targeted laboratory experiments. However, two issues might hamper the achievement of fruitful outcomes. On the one hand, detailed mechanistic models can involve hundreds or thousands of molecular species and their intermediate complexes, as well as hundreds or thousands of chemical reactions, a situation generally occurring in rule-based modeling. On the other hand, the computational analysis of a model typically requires the execution of a large number of simulations for its calibration, or to test the effect of perturbations. As a consequence, the computational capabilities of modern Central Processing Units can be easily overtaken, possibly making the modeling of biochemical networks a worthless or ineffective effort. To the aim of overcoming the limitations of the current state-of-the-art simulation approaches, we present in this paper FiCoS, a novel “black-box” deterministic simulator that effectively realizes both a fine-grained and a coarse-grained parallelization on Graphics Processing Units. In particular, FiCoS exploits two different integration methods, namely, the Dormand–Prince and the Radau IIA, to efficiently solve both non-stiff and stiff systems of coupled Ordinary Differential Equations. We tested the performance of FiCoS against different deterministic simulators, by considering models of increasing size and by running analyses with increasing computational demands. FiCoS was able to dramatically speedup the computations up to 855×, showing to be a promising solution for the simulation and analysis of large-scale models of complex biological processes.
Germline genome modification through novel political, ethical, and social lenses
Authors: Xafis Vicki , Schaefer G. Owen , Labude Markus K. , Zhu Yujia , Holm Soren , Foo Roger Sik-Yin , Lai Poh San , Chadwick Ruth
Published: September 2021

Much has been written about gene modifying technologies (GMTs), with a particularly strong focus on human germline genome editing (HGGE) sparked by its unprecedented clinical research application in 2018, shocking the scientific community. This paper applies political, ethical, and social lenses to aspects of HGGE to uncover previously underexplored considerations that are important to reflect on in global discussions. By exploring 4 areas—(1) just distribution of HGGE benefits through a realist lens; (2) HGGE through a national interest lens; (3) “broad societal consensus” through a structural injustice lens; and (4) HGGE through a scientific trustworthiness lens—a broader perspective is offered, which ultimately aims to enrich further debates and inform well-considered solutions for developments in this field. The application of these lenses also brings to light the fact that all discussions about scientific developments involve a conscious or unconscious application of a lens that shapes the direction of our thinking.
The impact of access to water supply and sanitation on the prevalence of active trachoma in Ethiopia: A systematic review and meta-analysis
Authors: Abebe Thomas Ayalew , Tucho Gudina Terefe
Published: September 2021

Background

Trachoma is a worldwide infectious disease causing blindness. Trachoma continued as a public health problem in Ethiopia due to a lack of sanitation and inadequate prevention strategies. This study aimed to identify the impact of water supply and sanitation intervention on preventing active trachoma among children.

Methods

Systematic literature searches were performed from 4 international databases. The search involved articles published from January 1995 up to March 2019. The Cochran Q and I2 statistical tests were used to check heterogeneity among the studies. A random-effect meta-analysis was employed to determine the pooled estimates with a 95% confidence interval (CI). Data analysis was performed using the CMA V.3 and RevMan 5 software program, and the result of the systematic review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Findings

Out of 211 studies screened for the analysis, only 29 studies were finally included in this systematic review and meta-analysis. The result revealed factors that are significantly associated with increased odds of active trachoma. Accordingly, households with no access to toilet facilities (odds ratio [OR]: 2.04, 95% CI: 1.75–2.38), no access to improved water (OR: 1.58, 95% CI: 1.27–1.96), and do not practice regular face washing for children (OR: 4.19, 95% CI: 3.02–5.81) have shown increased odds of active trachoma. Besides, the results show a higher prevalence of active trachoma among children who did not wash their faces with soap and frequently.

Conclusions

The study found strong evidence that lack of access to water, sanitation, and hygiene (WASH) was associated with increased prevalence of active trachoma among children. Therefore, a comprehensive and partnership-oriented program is needed to tackle the problem, but further study will be required to strengthen its implementation.