bluuebunny/crossref_metadata_2025 huggingface dataset:
Οικονομικές παράμετροι της πολιτικής δίκης στην ελληνική και διεθνή δικονομική σκηνή
Authors: Δούκα Αναστασία
Published: November 2021

Η παρούσα διδακτορική διατριβή προσεγγίζει το δίκαιο των δικαστικών εξόδων, των μηχανισμών χρηματοδότησης της δίκης και των χρηματικών ποινών τάξης στην ελληνική και διεθνή δικονομική σκηνή υπό μία τελολογική και δικαιοσυγκριτική σκοπιά. Σημείο εκκίνησης της τελολογικής ερμηνείας αποτελεί η καταγραφή των δικονομικών αρχών, που προκύπτουν από την άρρηκτη σύνδεση του δικαίου των δικαστικών εξόδων με την έννοια της αποτελεσματικότητας στην παροχή έννομης προστασίας (άρθρ. 20 § 1 Σ και 6 § 1 ΕΣΔΑ). Η δικαιοσυγκριτική ερμηνεία εστιάζει στη συστηματική παρουσίαση και αξιολόγηση των ρυθμίσεων περί κατανομής της δικαστικής δαπάνης σε 40 συνολικά δικαιοταξίες, αποδίδοντας ιδιαίτερη έμφαση στο αγγλικό, στο αμερικανικό και στο γερμανικό δικονομικό δίκαιο, με απώτερο στόχο την άντληση γνωστικής αξίας και τη μεταφορά της στην εγχώρια δικονομική σκηνή. Στο πεδίο του ελληνικού δικαίου των δικαστικών εξόδων εξετάζονται αναλυτικά η αρχική και η τελική κατανομή της δικαστικής δαπάνης, η χρηματοδότηση της δίκης και οι χρηματικές ποινές τάξης, ενώ ταυτόχρονα αναδεικνύονται τα προβλήματα που αντιμετωπίζει η ελληνική νομολογία και αναζητούνται λύσεις βάσει τελολογικών σταθμίσεων και δικαιοσυγκριτικών προσεγγίσεων. Τέλος, η διατριβή ανοίγει τον επιστημονικό διάλογο επί του κρίσιμου θέματος των δικαστικών εξόδων στις διασυνοριακές διαφορές εντός Ευρωπαϊκής Ένωσης, υπογραμμίζοντας την απουσία συστηματικής ενοποίησης των διατάξεων επιδίκασης δικαστικής δαπάνης σε επίπεδο ευρωπαϊκού δικονομικού δικαίου.
Lightning safety awareness level in Malaysia
Authors: Nazri Khairul , Lim Siow Chun , Gomes Chandima
Published: November 2021

Introduction: Malaysia is one of the countries with the highest lightning flash density globally. While sufficiency of lightning protection system is crucial to ensure human safety against lightning strikes, the public awareness towards lightning safety is also equally important in Malaysia. Hence, this study was conducted to understand the current lightning safety awareness level of the Malaysian population.

Methods: An online questionnaire survey which consists of 22 scientific statements of lightning was first developed in Malay and English. The questionnaire allows the respondent to also check their own score upon completion of the questionnaire. It was then distributed to the public for data collection. The sample size comprised of both genders, all layers of society from various educational level and social background.

Results: Overall, the awareness on lightning safety amongst Malaysian is at moderate level with an average score of slightly above 50%. Urbanites scored marginally better than their rural counterparts. One’s education level does not dictate their awareness level of lightning safety.

Discussion: In conclusion, the public in Malaysia needs to be better educated on lightning safety. Similar studies should be replicated in other countries experiencing similar levels of lightning activity to better understand the public’s perception on lightning.
Evaluation of electrocardiogram: numerical vs. image data for emotion recognition system
Authors: Sayed Ismail Sharifah Noor Masidayu , Ab. Aziz Nor Azlina , Ibrahim Siti Zainab , Nawawi Sophan Wahyudi , Alelyani Salem , Mohana Mohamed , Chia Chun Lee
Published: November 2021

Background: The electrocardiogram (ECG) is a physiological signal used to diagnose and monitor cardiovascular disease, usually using ECG wave images. Numerous studies have proven that ECG can be used to detect human emotions using numerical data; however, ECG is typically captured as a wave image rather than as a numerical data. There is still no consensus on the effect of the ECG input format (either as an image or a numerical value) on the accuracy of the emotion recognition system (ERS). The ERS using ECG images is still inadequately studied. Therefore, this study compared ERS performance using ECG image and ECG numerical data to determine the effect of the ECG input format on the ERS.

Methods: This study employed the DREAMER dataset, which contains 23 ECG recordings obtained during audio-visual emotional elicitation. Numerical data was converted to ECG images for the comparison. Numerous approaches were used to obtain ECG features. The Augsburg BioSignal Toolbox (AUBT) and the Toolbox for Emotional feature extraction from Physiological signals (TEAP) extracted features from numerical data. Meanwhile, features were extracted from image data using Oriented FAST and rotated BRIEF (ORB), Scale Invariant Feature Transform (SIFT), KAZE, Accelerated-KAZE (AKAZE), Binary Robust Invariant Scalable Keypoints (BRISK), and Histogram of Oriented Gradients (HOG). Dimension reduction was accomplished using linear discriminant analysis (LDA), and valence and arousal were classified using the Support Vector Machine (SVM).

Results: The experimental results indicated that numerical data achieved arousal and valence accuracy of 69% and 79%, respectively, which was greater than those of image data. For ECG images, the highest accuracy for arousal was 58% percent; meanwhile, the valence was 63%.

Conclusions: The finding showed that numerical data provided better accuracy for ERS. However, ECG image data which shows positive potential and can be considered as an input modality for the ERS.
Case Report: Acute abdomen presentation revealing a metastatic invasive mole with uterine rupture
Authors: Dhieb Fatma , Boumediene Miriam , Saoussem Armi , Mariem Garci , Nabil Mathlouthi , Bel Haj Kacem Linda , Ksentini Meriem , Jrad Miriam
Published: November 2021

Gestational trophoblastic neoplasia refers to the aggressive subset of gestational trophoblastic disease, including invasive mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. These tumors may have atypical clinical presentations that can mislead the diagnosis.

The reported case is a 48-year-old woman in perimenopause, without any history of vaginal bleedings nor molar pregnancy, who presented to the Emergency Department with acute abdominal pain. Serum beta human chorionic gonadotropin (β-HCG) was highly elevated at 261 675.23 mIU/ml. A complicated invasive mole was suspected, and an abdominal computed tomography was performed, showing a moderate hemoperitoneum associated to complex cystic and solid uterine mass, with a common left iliac adenomegaly and multiple pulmonary nodules. MRI showed a multiloculated cystic uterine mass with zones of hemorrhage recalling an invasive mole with perforation of the posterior uterus wall, associated to a high abundance hemoperitoneum. The diagnosis of a metastatic invasive mole complicated of uterine rupture and hemoperitoneum was retained.

A surgical intervention was decided immediately and a subtotal hysterectomy with bilateral annexectomy was done. Pathologic examination of the specimen was positive for an invasive mole. The patient was proposed for chemotherapy.

This case study will increase awareness of unusual clinical presentations of gestational trophoblastic neoplasia

We believe that our case will contribute to the literature not only because of the rarity of this entity in perimenopausal period, but also due the atypical clinical presentation as acute abdomen without vaginal bleeding nor history of molar pregnancy evacuation
Presence, flow, and narrative absorption questionnaires: a scoping review
Authors: Pianzola Federico
Published: November 2021

Background: This is a review and analysis of the questionnaires most used in empirical research on psychological phenomena labelled as “presence,” “flow,” and “narrative absorption,” mostly for experiences mediated by technology (printed books, screens for games and films, and virtual reality). Overlapping concepts have been formulated in different fields according to specific disciplinary interests and based on knowledge within each field.

Objectives: This review focuses on how language is actually used in questionnaire items, rather than on how concepts are formulated top-down and associated with corresponding linguistic expressions that become items of a questionnaire. The goal is to highlight similarities and overlaps in order to show a possible interdisciplinary agreement about the core aspects of the psychological states elicited by mediated experiences.

Eligibility criteria: Questionnaires developed or used for research about VR, video games, films, or books have been selected for analysis. They should be available in English and used in empirical research since the year 2000.

Sources of evidence: A search has been performed through Google Scholar and two other disciplinary bibliographies edited by international learned societies.

Charting methods: The items of each questionnaire are categorized based on their wordings, and thus independently from the conceptual models within which they have been developed.  Based on this categorization, various domains to which the items can be ascribed are identified (e.g. space, realism, agency, etc.) and psychological phenomena are linked to them (e.g. presence, social presence, narrative absorption, etc.).

Results: 308 items in 23 questionnaires have been found to have overlapping of wordings.

Conclusions: A list of the core aspects of presence, social presence, flow, and narrative absorption is presented, together with a critical selection of items suitable to measure each construct.
Impact on the service volume of a single hand surgery center during the COVID-19 pandemic period in Daegu
Authors: Oh Sang Ho , Kim Young Woo , Woo Sang Hyun
Published: November 2021

Purpose: We investigated what changes occurred at single hand surgery center during the coronavirus disease 2019 (COVID-19) pandemic in Daegu, Korea using patient data of 4 years (2018–2021).Methods: This is a single-center retrospective study of patients visiting our center during the COVID-19 pandemic (January 22 to May 6, 2020) in comparison to the most recent 4 years from 2018 to 2021. Service volumes (SVs) including the number of in/outpatients, emergency room, elective, and emergency surgeries were analyzed. The demographics, injury mechanism, and place of injury of hand trauma were analyzed in patients seen during the peak period of COVID-19 (February 24 to March 9, 2020) at W Hospital.Results: SVs were significantly reduced in 2020 as compared with other years. The SVs except for the number of emergency surgeries have recovered after 2 months from the first confirmed case of COVID-19 in Daegu, Korea. At the peak period, the effect of COVID-19 was weak on emergency room-related SVs. In addition, a daily number of in/outpatients and elective surgeries had a statistically significant negative correlation with the number of COVID-19 confirmed (p<0.05). During the peak period, superficial laceration increased and finger and wrist fractures decreased. The number of cases occurring in workplace increased, however, occurring outside during daily life decreased.Conclusion: COVID-19 pandemic greatly reduces service volume in our center. Thorough protective strategy from COVID-19 such as personal protective equipment was essential for early recovery of hospital functions during the pandemic. In addition, manpower for the emergency room must be preserved during the pandemic. The results of our study, which reported SVs through the pandemic will help maintain the function of hand surgery centers.
Centrosymmetric universal realizability
Authors: Julio Ana , Linares Yankis R. , Soto Ricardo L.
Published: November 2021

A list $\Lambda =\{\lambda_{1},\ldots,\lambda_{n}\}$ of complex numbers is said to be realizable, if it is the spectrum of an entrywise nonnegative matrix $A$. In this case, $A$ is said to be a realizing matrix. $\Lambda$ is said to be universally realizable, if it is realizable for each possible Jordan canonical form (JCF) allowed by $\Lambda$. The problem of the universal realizability of spectra is called the universal realizability problem (URP). Here, we study the centrosymmetric URP, that is, the problem of finding a nonnegative centrosymmetric matrix for each JCF allowed by a given list $\Lambda $. In particular, sufficient conditions for the centrosymmetric URP to have a solution are generated.
Zero lock-in implementation by phase wrapping/unwrapping in a ring laser gyroscope
Authors: Lee Jae-Cheul , Cho Hyun-Ju , Yang Ho-Soon
Published: November 2021

The main factors that limit the performance of ring laser gyroscopes include random walk, quantization noise, and bias stability. The first two factors determine the alignment time for navigation systems, and the bias stability error can result in long-term accuracy. We show that a phase wrapping/unwrapping algorithm, which has been widely used in interferometry fields, can be utilized to remove lock-in and quantization errors by implementing a zero-lock-in ring laser gyroscope. Furthermore, the performance of the ring laser gyroscope with no mechanical dither is described, and mirror dithering, instead of mechanical dithering, is proposed.
Randomly aperiodically poled LiNbO3 crystal design by Monte Carlo–Metropolis with simulated annealing optimization for ultrabroadband photon pair generation
Authors: Ramos-Israde Elier , Garay-Palmett Karina , Cudney Roger S.
Published: November 2021

We report a scheme for generating ultrabroadband two-photon states by spontaneous parametric downconversion (SPDC) using randomly aperiodically poled crystals designed with an optimization algorithm based on the Monte Carlo–Metropolis method with simulated annealing. A particular SPDC source is discussed, showing results of the spectral and temporal properties of the emitted two-photon states, obtaining almost transform-limited SPDC biphoton wave packets. We also analyze the effect of fabrication errors on the SPDC.
Performance evaluation of InGaAs/InP single-photon avalanche diodes based on fitting of dark current
Authors: Li Li , Li Lin , Li Gang
Published: November 2021

We analyzed the dark current characteristics of InGaAs/InP single-photon avalanche diodes (SPADs) at different bias voltages and developed a method to evaluate SPAD material quality. We performed dark current and dark count experiments on two sample device groups. By sub-area fitting dark current experimental data, we obtained the material parameters for the two groups. The difference in the parameters between the two groups is attributed to the difference in the cavity temperatures used for epitaxial growth. Finally, we calculated the dark count probability of the two groups and validated the effectiveness of our method by comparing the calculated and experimental values. The evaluation method contributes to continuous improvements in the material quality of SPADs.
Real-valued diffraction calculations for computational holography [Invited]
Authors: Shimobaba Tomoyoshi , Tahara Tatsuki , Hoshi Ikuo , Shiomi Harutaka , Wang Fan , Hara Takayuki , Kakue Takashi , Ito Tomoyoshi
Published: November 2021

Computational holography, encompassing computer-generated holograms and digital holography, utilizes diffraction calculations based on complex-valued operations and complex Fourier transforms. However, for some holographic applications, only real-valued holograms or real-valued diffracted results are required. This study proposes a real-valued diffraction calculation that does not require any complex-valued operation. Instead of complex-valued Fourier transforms, we employ a pure real-valued transform. Among the several real-valued transformations that have been proposed, we employ the Hartley transformation. However, our proposed method is not limited to this transformation, as other real-valued transformations can be utilized.
Domain adaptation and transfer learning for failure detection and failure-cause identification in optical networks across different lightpaths [Invited]
Authors: Musumeci Francesco , Venkata Virajit Garbhapu , Hirota Yusuke , Awaji Yoshinari , Xu Sugang , Shiraiwa Masaki , Mukherjee Biswanath , Tornatore Massimo
Published: November 2021

Optical network failure management (ONFM) is a promising application of machine learning (ML) to optical networking. Typical ML-based ONFM approaches exploit historical monitored data, retrieved in a specific domain (e.g., a link or a network), to train supervised ML models and learn failure characteristics (a signature) that will be helpful upon future failure occurrence in that domain. Unfortunately, in operational networks, data availability often constitutes a practical limitation to the deployment of ML-based ONFM solutions, due to scarce availability of labeled data comprehensively modeling all possible failure types. One could purposely inject failures to collect training data, but this is time consuming and not desirable by operators. A possible solution is transfer learning (TL), i.e., training ML models on a source domain (SD), e.g., a laboratory testbed, and then deploying trained models on a target domain (TD), e.g., an operator network, possibly fine-tuning the learned models by re-training with few TD data. Moreover, in those cases when TL re-training is not successful (e.g., due to the intrinsic difference in SD and TD), another solution is domain adaptation, which consists of combining unlabeled SD and TD data before model training. We investigate domain adaptation and TL for failure detection and failure-cause identification across different lightpaths leveraging real optical SNR data. We find that for the considered scenarios, up to 20% points of accuracy increase can be obtained with domain adaptation for failure detection, while for failure-cause identification, only combining domain adaptation with model re-training provides significant benefit, reaching 4%–5% points of accuracy increase in the considered cases.
Robust optical axis control of monocular active gazing based on pan-tilt mirrors for high dynamic targets
Authors: Cao Ruimin , Fu Jian , Yang Hui , Wang Lihui , Ishikawa Masatoshi
Published: November 2021

The real-time and stability performance are both crucial for the active vision system (AVS) to gaze the high dynamic targets (HDTs). This study focused on the robust optical axis control mechanism of monocular AVS based on pan-tilt mirrors. We proposed an adaptive self-window to accommodate the HDTs within the region of interest. The minimum-envelope-ellipse and unscented-Kalman-filter methods were proposed to compensate and predict the angle of optical axis when the HDTs were blocked. The static and dynamic compensation error rates were less than 1.46% and 2.71%, prediction error rate was less than 13.88%, improving the gazing stability while ensuring real-time performance.
Fast and accurate spectral-estimation axial super-resolution optical coherence tomography
Authors: de Wit Jos , Angelopoulos Kostas , Kalkman Jeroen , Glentis George-Othon
Published: November 2021

Spectral-estimation OCT (SE-OCT) is a computational method to enhance the axial resolution beyond the traditional bandwidth limit. However, it has not yet been used widely due to its high computational load, dependency on user-optimized parameters, and inaccuracy in intensity reconstruction. In this study, we implement SE-OCT using a fast implementation of the iterative adaptive approach (IAA). This non-parametric spectral estimation method is optimized for use on OCT data. Both in simulations and experiments we show an axial resolution improvement with a factor between 2 and 10 compared to standard discrete Fourier transform. Contrary to parametric methods, IAA gives consistent peak intensity and speckle statistics. Using a recursive and fast reconstruction scheme the computation time is brought to the sub-second level for a 2D scan. Our work shows that SE-OCT can be used for volumetric OCT imaging in a reasonable computation time, thus paving the way for wide-scale implementation of super-resolution OCT.
Terahertz hybrid plasmonic waveguides with ultra-long propagation lengths based on multilayer graphene-dielectric stacks
Authors: Huang Chia-Chih , Huang Chia-Chien
Published: November 2021

To develop on-chip photonic devices capable of transmitting terahertz signals beyond the propagation distance of millimeter while keeping deep subwavelength field confinement has been a challenging task. Herein, we propose a novel multilayer graphene-based hybrid plasmonic waveguide (MLGHPW) consisting of a cylindrical dielectric waveguide and hyperbolic metamaterials. The device is based on alternating graphene and dielectric layers on a rib substrate, operating in the terahertz range (f = 3 THz). We couple the fundamental dielectric waveguide mode with the fundamental volume plasmon polarition modes originated from the coupling of plasmon polaritons at individual graphene sheets. The resulting hybrid mode shows ultra-low loss compared with the conventional GHPW modes at the comparable mode sizes. The present MLGHPW demonstrated a few millimeters of propagation length while keeping the mode area of 10−3 A0, where A0 is the diffraction-limited area, thus possessing a thirty times larger figure of merit (FoM) compared to other GHPWs. The additional degree of freedom (the number of graphene layers) makes the proposed MLGHPW more flexible to control the mode properties. We investigated the geometry and physical parameters of the device and identified optimal FoM. Moreover, we analyzed the crosstalk between waveguides and confirmed the potential to construct compact on-chip terahertz devices. The present design might have the possible extensibility to other graphene-like materials, like silicene, germanen, stanene etc.
Thermal stability of wavefront shaping using a DMD as a spatial light modulator
Authors: Rudolf Benjamin , Du Yang , Turtaev Sergey , Leite Ivo T. , Čižmár Tomáš
Published: November 2021

Computer-controlled spatial modulation of coherent light has enabled multiple new ways of imaging through complex media. MEMS-based digital micromirror devices (DMDs) employed as spatial light modulators present considerably higher display frame rates compared to the popular alternative based on liquid crystal technology. For a progress beyond laboratory conditions, the digital hologram projected with a DMD needs to remain time-invariant after the wavefront correction. The thermal load of the DMD when operating at the highest display frame rates is one of the main sources of wavefront deviations that significantly impacts the imaging performance over time. In this work, we studied the wavefront deviations induced by temperature variation of the DMD, and show that they correspond to low-order aberrations which can be represented by Zernike polynomials up to the second order. Further, we study their influence on the focussing quality using wavefront shaping on two popular model systems – a highly-scattering diffuser and a multimode optical fibre – and verify a rapid degradation as the DMD temperature departs from the initial calibration temperature. By actively controlling and stabilizing the temperature of the DMD with a thermoelectric cooler, we demonstrate that the stability of high-speed DMD-based wavefront shaping systems can be greatly extended in time, without the need for recalibration.
Dual-wavelength switchable, mid-infrared quantum cascade laser with two shallow-etched distributed Bragg reflectors
Authors: Guan Yanjiao , Wang Lijun , Zhuo Ning , Zhang Jinchuan , Zhai Shenqiang , Liu Junqi , Liu Shuman , Liu Fengqi
Published: November 2021

A dual-wavelength quantum cascade laser (QCL) with two shallow-etched distributed Bragg reflectors is designed and fabricated. Based on a heterogeneous active region within a single waveguide, single-mode emission at 7.6μm and 8.2μm was achieved. The two wavelengths can be independently controlled by selective current injection on different regions of the device, which are electrically isolated. High optical powers of about 275mW and 218mW at room temperature were obtained for the single-mode emission at 7.6μm and 8.2μm, respectively. The presented design concept for high power, dual-wavelength switchable, mid-infrared QCLs is significant in developing miniaturized multi-species gas detection systems.
High-responsivity, self-driven visible-near infrared Sb2Se3 nanorod array photodetector
Authors: Zhang Yusong , Zhang Yiran , Ma Haiya , Feng Yang , Wang Shufang , Li Zhiqiang
Published: November 2021

Anisotropic antimony selenide (Sb2Se3) semiconductor has received considerable attention due to its unique one-dimensional crystal structure and corresponding superior and anisotropic optical and electronic properties. It is a promising material for a wide range of applications related to electronics and optoelectronics. Herein, we demonstrate a high-performance and self-powered Sb2Se3 nanorod array-based core/shell heterojunction detector fabricated on glass substate. The detector shows a wide spectral photoresponse range from visible to near-infrared (405-980 nm). The detector yields a detectivity of as high as 2.06×1012 Jones in the visible light (638 nm) and that of 1.82×1012 Jones (830 nm) at zero bias. Due to the strong built-in filed and excellent carrier transport, the detector exhibits ultrafast response speed at both rise (30 μs) and decay (68 μs) processes. Further analysis demonstrates that the noise is mainly generated from the 1/f noise in the low frequency range, while it is affected by the shot noise and generation-recombination noise in high frequency.
In-plane directionality control of strongly localized resonant modes of light in disordered arrays of dielectric scatterers
Authors: Naziul Haque A. K. M. , Ahmed Tashfiq , Baten Md Zunaid
Published: November 2021

In this work we propose and analyze techniques of in-plane directionality control of strongly localized resonant modes of light in random arrays of dielectric scatterers. Based on reported diameters and areal densities of epitaxially grown self-organized nanowires, two-dimensional (2D) arrays of dielectric scatterers have been analyzed where randomness is gradually increased along a preferred direction of directionality enhancement. In view of the multiple-scattering mediated wave dynamics and directionality enhancement of light in such arrays, a more conveniently realizable, practical structure is proposed where a 2D periodic array is juxtaposed with a uniform, random scattering medium. Far- and near-field emission characteristics of such arrays show that in spite of the utter lack of periodicity in the disordered regime of the structure, directionality of the high-Q resonant modes is modified such that on average more than 70% of the output power is emitted along the pre-defined direction of preference. Such directionality enhancement and strong localization are nonexistent when the 2D periodic array is replaced with a one-dimensional Bragg reflector, thereby confirming the governing role of in-plane multiple scattering in the process. The techniques presented herein offer novel means of realizing not only directionality tunable edge-emitting random lasers but also numerous other disordered media based photonic structures and systems with higher degrees of control and tunability.
Broadband perfect transparency-to-absorption switching in tilted anisotropic metamaterials based on the anomalous Brewster effect
Authors: Ma Zhikai , Fan Huiying , Zhou Hang , Huang Min , Luo Jie
Published: November 2021

Dynamically switchable light transmission/absorption functionality is highly desirable in sensing and functional devices. However, the operating bandwidth of the newly emerging schemes using resonant meta-structures is inherently limited. In this work, we design and numerically demonstrate a non-resonant tilted anisotropic metamaterial consisting of phase-change materials. When the phase transition of the phase-change material from amorphous phase to crystalline phase occurs, the functionality of the metamaterial can be switched from perfect transparency to perfect absorption for transverse-magnetic polarization under oblique incidence over a broad spectrum. Such a remarkable phenomenon originates in the anomalous Brewster effect, which enables broadband reflectionless transmission/absorption of light under the anomalous Brewster’s angle. Moreover, gradient metamaterials exhibiting dynamically controllable functionality for incident light with an almost arbitrary wavefront are demonstrated. The proposed metamaterials are simple but highly efficient, which may find applications in sensing and advanced and intelligent optical devices.
Deep tissue scattering compensation with three-photon F-SHARP
Authors: Berlage Caroline , Tantirigama Malinda L. S. , Babot Mathias , Di Battista Diego , Whitmire Clarissa , Papadopoulos Ioannis N. , Poulet James F. A. , Larkum Matthew , Judkewitz Benjamin
Published: November 2021

Optical imaging techniques are widely used in biological research, but their penetration depth is limited by tissue scattering. Wavefront shaping techniques are able to overcome this problem in principle, but are often slow, and their performance depends on the sample. This greatly reduces their practicability for biological applications. Here we present a scattering compensation technique based on three-photon excitation, which converges faster than comparable two-photon (2P) techniques and works reliably even on densely labeled samples, where 2P approaches fail. To demonstrate its usability and advantages for biomedical imaging, we apply it to the imaging of dendritic spines on layer 5 neurons labeled with green fluorescent protein in an anesthetized mouse.
Synchronization of gigahertz core resonances in multiple photonic crystal fiber cores by timing-modulated harmonic mode locking
Authors: Yeh Dung-Han , He Wenbin , Pang Meng , Jiang Xin , Russell Philip St.J.
Published: November 2021

Synchronization of mechanical oscillators by optical forces is a topic that has been much explored in recent years, for example, in the context of SiN microdisk resonators. Here we report stable long-term synchronization of the core vibrations of three different photonic crystal fibers, driven intra-cavity by a 2 GHz train of timing-modulated pulses in a high harmonic opto-acoustically mode-locked fiber laser. The core resonances are equally spaced in frequency and are coupled purely by the optical field. Under the correct conditions, they become stably synchronized, being simultaneously driven by the timing-modulated pulse train. Floquet–Bloch theory, in which the pulses are treated as particles trapped in potential wells and coupled by optomechanical back-action, describes the complex temporal dynamics observed in the experiments. This unique system provides a novel means of modifying the temporal structure of pulse trains running at few-gigahertz repetition rates.
Slide-free histological imaging by microscopy with ultraviolet surface excitation using speckle illumination
Authors: Wong Ivy H. M. , Zhang Yan , Chen Zhenghui , Kang Lei , Wong Terence T. W.
Published: November 2021

Microscopy with ultraviolet surface excitation (MUSE) is a promising slide-free imaging technique to improve the time-consuming histopathology workflow. However, since the penetration depth of the excitation light is tissue dependent, the image contrast could be significantly degraded when the depth of field of the imaging system is shallower than the penetration depth. High-resolution cellular imaging normally comes with a shallow depth of field, which also restricts the tolerance of surface roughness in biological specimens. Here we propose the incorporation of MUSE with speckle illumination (termed MUSES), which can achieve sharp imaging on thick and rough specimens. Our experimental results demonstrate the potential of MUSES in providing histological images with

∼
1
  
μm

spatial resolution and improved contrast, within 10 minutes for a field of view of

1.7
  
mm
×
1.2
  
mm

. With the extended depth of field feature, MUSES also relieves the constraint of tissue flatness. Furthermore, with a color transformation assisted by deep learning, a virtually stained histological image can be generated without manual tuning, improving the applicability of MUSES in clinical settings.
Fitness costs of female choosiness are low in a socially monogamous songbird
Authors: Forstmeier Wolfgang , Wang Daiping , Martin Katrin , Kempenaers Bart
Published: November 2021

Female mate choice is thought to be responsible for the evolution of many extravagant male ornaments and displays, but the costs of being too selective may hinder the evolution of choosiness. Selection against choosiness may be particularly strong in socially monogamous mating systems, because females may end up without a partner and forego reproduction, especially when many females prefer the same few partners (frequency-dependent selection). Here, we quantify the fitness costs of having mating preferences that are difficult to satisfy, by manipulating the availability of preferred males. We capitalize on the recent discovery that female zebra finches (Taeniopygia guttata) prefer males of familiar song dialect. We measured female fitness in captive breeding colonies in which one-third of females were given ample opportunity to choose a mate of their preferred dialect (two-thirds of all males; “relaxed competition”), while two-thirds of the females had to compete over a limited pool of mates they preferred (one-third of all males; “high competition”). As expected, social pairings were strongly assortative with regard to song dialect. In the high-competition group, 26% of the females remained unpaired, yet they still obtained relatively high fitness by using brood parasitism as an alternative reproductive tactic. Another 31% of high-competition females paired disassortatively for song dialect. These females showed increased levels of extra-pair paternity, mostly with same-dialect males as sires, suggesting that preferences were not abolished after social pairing. However, females that paired disassortatively for song dialect did not have lower reproductive success. Overall, females in the high-competition group reached equal fitness to those that experienced relaxed competition. Our study suggests that alternative reproductive tactics such as egg dumping can help overcome the frequency-dependent costs of being selective in a monogamous mating system, thereby facilitating the evolution of female choosiness.
Mouse-adapted SARS-CoV-2 protects animals from lethal SARS-CoV challenge
Authors: Muruato Antonio , Vu Michelle N. , Johnson Bryan A. , Davis-Gardner Meredith E. , Vanderheiden Abigail , Lokugamage Kumari , Schindewolf Craig , Crocquet-Valdes Patricia A. , Langsjoen Rose M. , Plante Jessica A. , Plante Kenneth S. , Weaver Scott C. , Debbink Kari , Routh Andrew L. , Walker David , Suthar Mehul S. , Shi Pei-Yong , Xie Xuping , Menachery Vineet D.
Published: November 2021

The emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has resulted in a pandemic causing significant damage to public health and the economy. Efforts to understand the mechanisms of Coronavirus Disease 2019 (COVID-19) have been hampered by the lack of robust mouse models. To overcome this barrier, we used a reverse genetic system to generate a mouse-adapted strain of SARS-CoV-2. Incorporating key mutations found in SARS-CoV-2 variants, this model recapitulates critical elements of human infection including viral replication in the lung, immune cell infiltration, and significant in vivo disease. Importantly, mouse adaptation of SARS-CoV-2 does not impair replication in human airway cells and maintains antigenicity similar to human SARS-CoV-2 strains. Coupled with the incorporation of mutations found in variants of concern, CMA3p20 offers several advantages over other mouse-adapted SARS-CoV-2 strains. Using this model, we demonstrate that SARS-CoV-2–infected mice are protected from lethal challenge with the original Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), suggesting immunity from heterologous Coronavirus (CoV) strains. Together, the results highlight the use of this mouse model for further study of SARS-CoV-2 infection and disease.
M-DATA: A statistical approach to jointly analyzing de novo mutations for multiple traits
Authors: Xie Yuhan , Li Mo , Dong Weilai , Jiang Wei , Zhao Hongyu
Published: November 2021

Recent studies have demonstrated that multiple early-onset diseases have shared risk genes, based on findings fromde novomutations (DNMs). Therefore, we may leverage information from one trait to improve statistical power to identify genes for another trait. However, there are few methods that can jointly analyze DNMs from multiple traits. In this study, we develop a framework called M-DATA (Multi-trait framework forDe novomutationAssociationTest withAnnotations) to increase the statistical power of association analysis by integrating data from multiple correlated traits and their functional annotations. Using the number of DNMs from multiple diseases, we develop a method based on an Expectation-Maximization algorithm to both infer the degree of association between two diseases as well as to estimate the gene association probability for each disease. We apply our method to a case study of jointly analyzing data from congenital heart disease (CHD) and autism. Our method was able to identify 23 genes for CHD from joint analysis, including 12 novel genes, which is substantially more than single-trait analysis, leading to novel insights into CHD disease etiology.
Source apportionment and quantification of liquid and headspace leaks from closed system drug-transfer devices via Selected Ion Flow Tube Mass Spectrometry (SIFT-MS)
Authors: Doepke Amos , Streicher Robert P.
Published: November 2021

A system to differentiate and quantify liquid and headspace vapor leaks from closed system drug-transfer devices (CSTDs) is presented. CSTDs are designed to reduce or eliminate hazardous drug (HD) exposure risk when compounding and administering HDs. CSTDs may leak liquid, headspace, or a mixture of the two. The amount of HD contained in liquid and headspace leaks may be substantially different. Use of a test solution containing two VOCs with differences in ratios of VOC concentrations in the headspace and liquid enables source apportionment of leaked material. SIFT-MS was used to detect VOCs from liquid and headspace leaks in the vapor phase. Included in this report is a novel method to determine the origin and magnitude of leaks from CSTDs. A limit of leak detection of 24 μL of headspace vapor and 0.14 μL of test liquid were found using Selected Ion Flow Tube Mass Spectrometry (SIFT-MS).
Evaluation of morphological traits of wheat varieties at germination stage under salinity stress
Authors: Gholizadeh Fatemeh , Mirzaghaderi Ghader , Danish Subhan , Farsi Mohammad , Marashi Seyed Hasan
Published: November 2021

Salinity stress is one of the major plant growth-limiting factors in agriculture. It causes ionic imbalance, thus decrease the growth and yield attributes of crops especially wheat. Seedling stage is considered as one of the most sensitive stages under salinity stress. Survival of seeds at seedling stage can overcome the adverse impacts of salinity stress to some extent. Selection of salt tolerant varieties in seedling stage is considered as an effective strategy. Hence, current study was conducted to examine the seed germination responses of four wheat varieties under different levels of salinity. The wheat varieties such as ‘Rakhshan’, ‘Sirvan’, ‘Pishgam’ and ‘Heidari’ were grown and four salinity levels of 0, 4, 8 and 12 dS/m were applied under completely randomized design. The varieties such as ‘Sirvan’, ‘Rakhshan’ and ‘Heidari’ showed significant response for germination compared to ‘Pishgam’ at 12 dS/m salinity. Furthermore, the variety ‘Rakhshan’ showed significantly higher germination rate (20.3%), higher root length (33.4%) and higher shoot length (84.3%) than ‘Pishgam’, ‘Sirvan’ and ‘Sirvan’ respectively. However, contrasting results were obtained for dry weight of seedlings where 12.2% increase was observed in ‘Pishgam’ over ‘Rakhshan’ at 12 dS/m salinity that might be due to higher capability to uptake of Na and Cl ions. In conclusion, ‘Rakhshan’ wheat variety proved to be the most salinity tolerant as it grew better under saline soil conditions. More investigations at field level are recommended to declare ‘Rakhshan’ as salinity tolerant cultivar.
Safe reopening of college campuses during COVID-19: The University of California experience in Fall 2020
Authors: Pollock Brad H. , Kilpatrick A. Marm , Eisenman David P. , Elton Kristie L. , Rutherford George W. , Boden-Albala Bernadette M. , Souleles David M. , Polito Laura E. , Martin Natasha K. , Byington Carrie L.
Published: November 2021

Background

Epidemics of COVID-19 in student populations at universities were a key concern for the 2020–2021 school year. The University of California (UC) System developed a set of recommendations to reduce campus infection rates. SARS-CoV-2 test results are summarized for the ten UC campuses during the Fall 2020 term.

Methods

UC mitigation efforts included protocols for the arrival of students living on-campus students, non-pharmaceutical interventions, daily symptom monitoring, symptomatic testing, asymptomatic surveillance testing, isolation and quarantine protocols, student ambassador programs for health education, campus health and safety pledges, and lowered density of on-campus student housing. We used data from UC campuses, the UC Health–California Department of Public Health Data Modeling Consortium, and the U.S. Census to estimate the proportion of each campus’ student populations that tested positive for SARS-CoV-2 and compared it to the fraction individuals aged 20–29 years who tested positive in their respective counties.

Results

SARS-CoV-2 cases in campus populations were generally low in September and October 2020, but increased in November and especially December, and were highest in early to mid-January 2021, mirroring case trajectories in their respective counties. Many students were infected during the Thanksgiving and winter holiday recesses and were detected as cases upon returning to campus. The proportion of students who tested positive for SARS-CoV-2 during Fall 2020 ranged from 1.2% to 5.2% for students living on campus and was similar to students living off campus. For most UC campuses the proportion of students testing positive was lower than that for the 20–29-year-old population in which campuses were located.

Conclusions

The layered mitigation approach used on UC campuses, informed by public health science and augmented perhaps by a more compliant population, likely minimized campus transmission and outbreaks and limited transmission to surrounding communities. University policies that include these mitigation efforts in Fall 2020 along with SARS-CoV-2 vaccination, may alleviate some local concerns about college students returning to communities and facilitate resumption of normal campus operations and in-person instruction.
‘We dry contaminated meat to make it safe’: An assessment of knowledge, attitude and practices on anthrax during an outbreak, Kisumu, Kenya, 2019
Authors: Mugo Bernard Chege , Lekopien Cornelius , Owiny Maurice
Published: November 2021

Introduction

Anthrax is the highest-ranked priority zoonotic disease in Kenya with about ten human cases annually. Anthrax outbreak was reported in Kisumu East Sub County after some villagers slaughtered and ate beef from a cow suspected to have died of anthrax. We aimed at establishing the magnitude of the outbreak, described associated factors, and assessed community knowledge, attitude, and practices on anthrax.

Methods

We reviewed human and animal records, conducted case search and contact tracing using standard case definitions in the period from July 1through to July 28, 2019. A cross-sectional study was conducted to assess community knowledge, attitude, and practices towards anthrax. The household selection was done using multistage sampling. We cleaned and analyzed data in Ms. Excel and Epi Info. Descriptive statistics were carried out for continuous and categorical variables while analytical statistics for the association between dependent and independent variables were calculated.

Results

Out of 53 persons exposed through consumption or contact with suspicious beef, 23 cases (confirmed: 1, probable: 4, suspected: 18) were reviewed. The proportion of females was 52.17% (12/23), median age 13.5 years and range 45 years. The attack rate was 43.4% (23/53) and the case fatality rate was 4.35% (1/23). Knowledge level, determined by dividing those considered to be ‘having good knowledge’ on anthrax (numerator) by the total number of respondents (denominator) in the population regarding cause, transmission, symptoms and prevention was 51% for human anthrax and 52% for animal anthrax. Having good knowledge on anthrax was associated with rural residence [OR = 5.5 (95% CI 2.1–14.4; p<0.001)], having seen a case of anthrax [OR = 6.2 (95% CI 2.8–14.2; p<0.001)] and among those who present cattle for vaccination [OR = 2.6 (95% CI 1.2–5.6; p = 0.02)]. About 23.2% (26/112) would slaughter and sell beef to neighbors while 63.4% (71/112) would bury or burn the carcass. Nearly 93.8% (105/112) believed vaccination prevents anthrax. However, 5.4% (62/112) present livestock for vaccination.

Conclusion

Most anthrax exposures were through meat consumption. Poor knowledge of the disease might hamper prevention and control efforts.
Profiling of Bacillus cereus on Canadian grain
Authors: Gamage Niradha Withana , Bamforth Janice , Ashfaq Tehreem , Bernard Kathryn , Gräfenhan Tom , Walkowiak Sean
Published: November 2021

Microorganisms that cause foodborne illnesses challenge the food industry; however, environmental studies of these microorganisms on raw grain, prior to food processing, are uncommon. Bacillus cereus sensu lato is a diverse group of bacteria that is common in our everyday environment and occupy a wide array of niches. While some of these bacteria are beneficial to agriculture due to their entomopathogenic properties, others can cause foodborne illness; therefore, characterization of these bacteria is important from both agricultural and food safety standpoints. We performed a survey of wheat and flax grain samples in 2018 (n = 508) and 2017 (n = 636) and discovered that B. cereus was present in the majority of grain samples, as 56.3% and 85.2%, in two years respectively. Whole genome sequencing and comparative genomics of 109 presumptive B. cereus isolates indicates that most of the isolates were closely related and formed two genetically distinct groups. Comparisons to the available genomes of reference strains suggested that the members of these two groups are not closely related to strains previously reported to cause foodborne illness. From the same data set, another, genetically more diverse group of B. cereus was inferred, which had varying levels of similarity to previously reported strains that caused disease. Genomic analysis and PCR amplification of genes linked to toxin production indicated that most of the isolates carry the genes nheA and hbID, while other toxin genes and gene clusters, such as ces, were infrequent. This report of B. cereus on grain from Canada is the first of its kind and demonstrates the value of surveillance of bacteria naturally associated with raw agricultural commodities such as cereal grain and oilseeds.