bluuebunny/crossref_metadata_2025 huggingface dataset:
Trunk and leg kinematics of grounded and aerial running in bipedal macaques
Authors: Blickhan Reinhard , Andrada Emanuel , Hirasaki Eishi , Ogihara Naomichi
Published: December 2020

Across a wide range of Froude speeds, non-human primates such as macaques prefer to use grounded and aerial running when locomoting bipedally. Both gaits are characterized by bouncing kinetics of the center of mass. On the other hand, a discontinuous change from pendular to bouncing kinetics occurs in human locomotion. To clarify the mechanism underlying these differences in bipedal gait mechanics between humans and non-human primates, we investigated the influence of gait on joint kinematics in the legs and trunk of three macaques crossing an experimental track. The coordination of movement was compared with observations available for primates. Compared to human running, macaque leg retraction cannot merely be produced by hip extension, but needs to be supported by substantial knee flexion. As a result, despite quasi-elastic whole-leg operation, the macaque's knee showed only minor rebound behavior. Ankle extension resembled that observed during human running. Unlike human running and independent of gait, torsion of the trunk represents a rather conservative feature in primates, and pelvic axial rotation added to step length. Pelvic lateral lean during grounded running by macaques (compliant leg) and human walking (stiff leg) depends on gait dynamics at the same Froude speed. The different coordination between the thorax and pelvis in the sagittal plane as compared to human runners indicates different bending modes of the spine. Morphological adaptations in non-human primates to quadrupedal locomotion may prevent human-like operation of the leg and limit exploitation of quasi-elastic leg operation despite running dynamics.
Winter honeybee (Apis mellifera) populations show greater potential to induce immune response than summer ones after immune stimuli
Authors: Dostálková Silvie , Dobeš Pavel , Kunc Martin , Hurychová Jana , Škrabišová Mária , Petřivalský Marek , Titěra Dalibor , Havlík Jaroslav , Hyršl Pavel , Danihlík Jiří
Published: December 2020

In the temperate climates of middle Europe and North America, two distinct honeybee (Apis mellifera) populations are found in colonies: short-living summer bees emerge in spring and survive until summer, whereas long-living winter bees emerge in late August and overwinter. Besides the difference in their life spans, each of these populations fulfills a different role in the colonies and individual bees have distinct physiological and immunological adaptations depending on their roles. For instance, winter worker bees have higher vitellogenin levels and larger reserves of nutrients in the fat body than summer bees. The differences between the immune systems of both populations are well described at the constitutive level; however, our knowledge of its inducibility is still very limited. In this study, we focus on the response of 10-day-old honeybee workers to immune challenges triggered in vivo by injecting heat-killed bacteria, with particular focus on honeybees that emerge and live under hive conditions. Responses to bacterial injections differed between summer and winter bees. The latter induced more intense response, including higher expression of antimicrobial genes and antimicrobial activity, as well as a significant decrease in vitellogenin gene expression and its concentration in the hemolymph. The intense immune response observed in winter honeybees may contribute to our understanding of the relationships between colony fitness and infection with pathogens, as well as its association with successful overwintering.
Acclimation to warm temperatures has important implications for mitochondrial function in Atlantic salmon (Salmo salar)
Authors: Gerber Lucie , Clow Kathy A. , Gamperl Anthony K.
Published: December 2020

In fishes, the capacity of thermal acclimation to preserve cardiac mitochondrial function under future warming scenarios is important to understand given the central role that cardiac energy metabolism and performance play in this taxa's thermal tolerance. We acclimated Atlantic salmon to 12 and 20°C (for>2 months), and investigated the effects of acute and chronic warming on cardiac mitochondrial respiration and ROS production (release rate) using high-resolution fluorespirometry. Further, we compared the sensitivity of mitochondrial respiration to nitric oxide (i.e., the NO IC50), and assessed the mitochondrial response to anoxia-reoxygenation (AR). Acute exposure to 20°C increased maximal mitochondrial respiration by ∼55%, however, the mitochondria's complex I-respiratory control ratio was 17% lower and ROS production was increased by≥60%. Acclimation to 20°C: i) preserved mitochondrial coupling and aerobic capacity; ii) decreased the mitochondria's ROS production by ∼30%; iii) increased the mitochondria's NO IC50 by ∼23%; iv) and improved mitochondrial membrane integrity at 20°C. AR did not affect mitochondrial function at 12°C, but acute exposure to 20°C and AR depressed maximal mitochondrial respiration (by ∼9%) and coupling (by ∼16%) without impacting ROS production. Finally, warm acclimation did not improve the capacity of mitochondria to recover from AR, indicating that there was no ‘cross tolerance’ between these challenges. Our findings provide compelling evidence that thermal plasticity of cardiac mitochondrial function contributes to the Atlantic salmon's capability to survive at≥20°C for prolonged periods, but question whether this plasticity may allow them to withstand high temperatures when combined with other stressors.
Τα παιδιά ως ερευνητές στο πλαίσιο του αειφόρου σχολείου
Authors: Δασκολιά Μαρία , Κέκερη Ευαγγελία , Τσεβρένη Ίριδα
Published: December 2020

Επίκεντρο της παρούσης έρευνας είναι η διερεύνηση της συμμετοχής μαθητών/τριών σε ερευνητικές διαδικασίες με θέμα το αειφόρο σχολείο στο πλαίσιο της περιβαλλοντικής εκπαίδευσης. Πρόκειται για μια μελέτη περίπτωσης, που κινείται στην ερευνητική παράδοση «τα παιδιά ως ερευνητές». Σε αυτή συμμετείχαν μαθητές/τριες ενός Γυμνασίου της Αττικής. Σκοπός της έρευνας ήταν να εξεταστεί με ποιους τρόπους η εκπαιδευτική παρέμβαση που σχεδιάστηκε από την ερευνητική ομάδα και υλοποιήθηκε στην ομάδα των μαθητών/τριών συνέβαλε στην ανάπτυξη της συμμετοχής τους στις διαφορετικές ερευνητικές διαδικασίες και να αναδειχτούν οι δυσκολίες που αντιμετωπίζουν όταν αναλαμβάνουν τον ρόλο «ερευνητών». Σύμφωνα με τα αποτελέσματα, η συμμετοχή των μαθητών/τριών διαμορφώθηκε σταδιακά, ανάλογα με τις διαφορετικές φάσεις υλοποίησης της έρευνας και τις παιδαγωγικές παρεμβάσεις της ερευνητικής ομάδας. Οι μαθητές/τριες καλλιέργησαν βασικές ερευνητικές ικανότητες, ξεπερνώντας δισταγμούς και τη μαθημένη παθητική στάση και ταυτόχρονα ενδυναμώθηκαν μέσα από τη συνεργασία τους με τους ερευνητές και την υποβοηθούμενη, ολοένα και μεγαλύτερη ανάληψη δικής τους πρωτοβουλίας. Οι δυσκολίες που συνάντησαν αφορούν κυρίως στην ανάληψη ενός πιο ενεργητικού ρόλου, στη χρήση των ερευνητικών εργαλείων και στη συνέπεια ως προς συνεργασία των ομάδων εκτός των πλαισίων που θέτει το ωρολόγιο σχολικό πρόγραμμα.
Effect of vitamin E supplementation on orthodontic tooth movement in Wistar rats: a prelimary study
Authors: Sufarnap Erliera , Siregar Darmayanti , Lindawati Yumi
Published: December 2020

Background: Tooth movement induced by the application of orthodontic force was initiated by inflammatory process. Studies have shown that vitamin E has an anti-inflammatory and antioxidant properties which perhaps could inhibit the tooth to move. This study aimed to evaluate the effect of vitamin E supplementation on orthodontic tooth movement in Wistar rats.

Methods: Wistar rats (n=56) were divided into two groups. Group 1 served as the control groups, while group 2 was given vitamin E for 14 days before application of orthodontic force. Each group was divided into four subgroups (n=7), corresponding to the number of days orthodontic force lasted, i.e. 0, 1, 3, 7 days. At each of these four time points, distance measurements and quantity of osteoblasts-osteoclasts were measured in each rat.

Results: Tooth movement distance was increased for group 2 than group 1 for all time intervals, but this difference was only statistically different on day 3 (p=0.001). For both groups, tooth movement was significantly different between each time interval in each group (p=0.041). The mean number of osteoblast cells was increased for group 2 compared to group 1 for all time intervals (p<0.05), but was not significant different between time intervals (p=0.897). The number of osteoclasts was not significantly different between groups, but it was statistically different between time intervals (p=0.004).

Conclusion: The outcome of this study demonstrated that group 2  resulted a better tooth movement compared to group 1 and significantly found on day 3, based on the distance measurement. The osteoclast cell numbers were the same within both control groups, whilst  the number of osteoblast cells in group 2 was significantly higher than those in group 1.
Clash of the pandemics – At least 150’000 adults in Switzerland suffer from obesity grades 2 or 3 and are thus at elevated risk for severe COVID-19
Authors: Staub Kaspar , Matthes Katarina L. , Rühli Frank , Bender Nicole
Published: December 2020

Background: Grade 2 and 3 obesity, alongside with other relevant risk factors, are substantially and independently associated with adverse outcomes of coronavirus disease 2019 (COVID-19). However, for Switzerland, due to the lack of synthesis studies, it is currently unknown how many people are affected by obesity at all. This knowledge may help to better estimate the relevance and size of this group at elevated risk, which could be incorporated into strategies to protect risk groups during the still unfolding COVID-19 pandemic. This study aimed to provide a first overall estimation of how many people in Switzerland are currently affected by grade 2 or 3 obesity.

Methods: Five representative national population-based studies were accessed which were conducted between 2012 and 2017 and which include data on height and weight of adult men and women in Switzerland.

Results: In Switzerland in 2012-2017, among the 11.20% adults who were obese (body mass index (BMI) ≥30.0kg/m2), 1.76% (95% CI 1.50-2.02) suffered from grade 2 obesity (BMI 35.0-39.9 kg/m2), and 0.58% (95% CI 0.50-0.66) from grade severe 3 obesity (BMI ≥40.0 kg/m2). Converted into estimated absolute population numbers, this corresponds to a total of approximately n=154,515 people who suffer from grade 2 or 3 obesity (n=116,216 and n=38,298, respectively).

Conclusions: This risk group includes many younger people in Switzerland. The number of people with obesity-related risk becomes 3.8 to 13.6 times higher if grade 1 obesity and overweight people are also included in this risk group, for which there are arguments arising in the latest literature. In general, this large group at risk for severe COVID-19 should be given more attention and support. If it is confirmed that obesity plays a major role in severe COVID-19 courses, then every kilo of body weight that is not gained or that is lost in lockdown counts.
DESIGN FEATURES OF MICROCIRCUITS BASIC ELEMENTS FOR SPACE
Authors: Zolnikov Vladimir , Skvortsova Tatyana , Strukov I. , Ilunina Anna , Maklakova Elena
Published: December 2020

The article describes a microcircuit intended for certification of CMOS technology for the production of RS LSI on SPS structures. Its general and technical characteristics are considered. The description and substantiation of the construction, which unites variables by switching layers, allows to implement library elements. The library of elements of the base matrix crystal is considered: its composition and development features. Formulas for calculating the signal delay by the bistable method and estimating the duration of the front of the response of an element at its output are given.
Tail-Heaviness, Asymmetry, and Profitability Forecasting by Quantile Regression
Authors: Tian Hui , Yim Andrew , Newton David P.
Published: December 2020

We show that quantile regression is better than ordinary-least-squares (OLS) regression in forecasting profitability for a range of profitability measures following the conventional setup of the accounting literature, including the mean absolute forecast error (MAFE) evaluation criterion. Moreover, we perform both a simulated-data and an archival-data analysis to examine how the forecasting performance of quantile regression against OLS changes with the shape of the profitability distribution. Considering the MAFE and mean squared forecast error (MSFE) criteria together, we see that the quantile regression is more accurate relative to OLS when the profitability to be forecast has a heavier-tailed distribution. In addition, the asymmetry of the profitability distribution has either a U-shape or an inverted-U-shape effect on the forecasting accuracy of quantile regression. An application of the distributional shape analysis framework to cash flow forecasting demonstrates the usefulness of the framework beyond profitability forecasting, providing additional empirical evidence on the positive effect of tail-heaviness and supporting the notion of an inverted-U-shape effect of asymmetry.

This paper was accepted by Shiva Rajgopal, accounting.
Extemporaneous Coordination in Specialist Teams: The Familiarity Complementarity
Authors: Ching Kenny , Forti Enrico , Rawley Evan
Published: December 2020

Team production is ubiquitous in the economy, but managing teams effectively remains a challenge for many organizations. This paper studies how familiarity among teammates influences the performance of specialist teams, relative to nonspecialist teams. Applying theories of team production to contexts where team members coordinate interdependent activities extemporaneously, we develop predictions about factors that shift the marginal returns to specialization along two dimensions of familiarity: social familiarity and functional familiarity. We test our hypotheses in the context of Defence of the Ancients 2 (DOTA2), a major e-sports game where, in some formats, players are exogenously assigned to five-person teams. After analyzing nearly 6.5 million matches, we find that specialist teams are relatively more successful when members are more socially and functionally familiar with one another. The results suggest that the plug-and-play perspective on specialist teams is incomplete; rather, specialization and familiarity are complements in dynamic environments where team members coordinate extemporaneously.

Funded: Financial support from the UCL School of Management and Worcester Polytechnic Institute is gratefully acknowledged.
Synovial fluid interleukin-6 is not superior to cell count and differential in the detection of periprosthetic joint infection
Authors: Mihalič René , Zdovc Jurij , Brumat Peter , Trebše Rihard
Published: December 2020

Aims

Synovial fluid white blood cell (WBC) count and percentage of polymorphonuclear cells (%PMN) are elevated at periprosthetic joint infection (PJI). Leucocytes produce different interleukins (IL), including IL-6, so we hypothesized that synovial fluid IL-6 could be a more accurate predictor of PJI than synovial fluid WBC count and %PMN. The main aim of our study was to compare the predictive performance of all three diagnostic tests in the detection of PJI.

Methods

Patients undergoing total hip or knee revision surgery were included. In the perioperative assessment phase, synovial fluid WBC count, %PMN, and IL-6 concentration were measured. Patients were labeled as positive or negative according to the predefined cut-off values for IL-6 and WBC count with %PMN. Intraoperative samples for microbiological and histopathological analysis were obtained. PJI was defined as the presence of sinus tract, inflammation in histopathological samples, and growth of the same microorganism in a minimum of two or more samples out of at least four taken.

Results

In total, 49 joints in 48 patients (mean age 68 years (SD 10; 26 females (54%), 25 knees (51%)) were included. Of these 11 joints (22%) were infected. The synovial fluid WBC count and %PMN predicted PJI with sensitivity, specificity, accuracy, PPV, and NPV of 82%, 97%, 94%, 90%, and 95%, respectively. Synovial fluid IL-6 predicted PJI with sensitivity, specificity, accuracy, PPV, and NPV of 73%, 95%, 90%, 80%, and 92%, respectively. A comparison of predictive performance indicated a strong agreement between tests.

Conclusions

Synovial fluid IL-6 is not superior to synovial fluid WBC count and %PMN in detecting PJI. Level of Evidence: Therapeutic Level II Cite this article: Bone Jt Open 2020;1-12:737–742.
TELEMONITORING OF BIOMEDICAL PARAMETERS - TECHNOLOGICAL ASPECTS AND APPLICATIONS
Authors:   Department of Information Systems and Technologies, Łukasiewicz Research Network — Institute of Medical Technology and Equipment, Sobotnicka Ewelina , Feige Daniel ,   Department of Information Systems and Technologies, Łukasiewicz Research Network — Institute of Medical Technology and Equipment, Sobotnicki Aleksander ,   Research Department, Łukasiewicz Research Network — Institute of Medical Technology and Equipment, Gacek Adam ,   Research Department, Łukasiewicz Research Network — Institute of Medical Technology and Equipment
Published: December 2020

Abstract: The article presents the main technological aspects of systems of telemonitoring of biomedical parameters, based on the example of research carried out in the Łukasiewicz Research Network — Institute of Medical Technology and Equipment, Zabrze. Medical telemonitoring covers technologies for the acquisition, processing and analysis of biomedical information. Data sources and technologies for obtaining biomedical information are an important element of medical telemonitoring. Medical telemonitoring systems are one of the main elements of telemedicine or telehealth. Telemonitoring of vital biomedical parameters is mainly used to perform remote diagnostics and medical rehabilitation. This applies primarily to patients from the so-called “high risk” groups, who are treated or rehabilitated outside hospitals. An important area for the application of medical telemonitoring is the safety of people working under extreme or stressful conditions. Telemonitoring of vital parameters can also be used to increase the safety of those who engage in physical activity for health promotion, sports and performance.
Effect of refractive index of packaging materials on the light extraction efficiency of COB-LEDs with millilens array
Authors: Yu Xingjian , Xiang Linyi , Zhou Shuling , Pei Naiqi , Luo Xiaobing
Published: December 2020

Lens arrays are introduced to diminish the total internal reflection (TIR) that happens at chip-encapsulant and encapsulant-air interfaces of chip-on-board light-emitting diodes (COB-LEDs), so as to improve the light extraction efficiency (LEE) of the COB-LEDs. However, the LEE of COB-LEDs with lens array depends on the refractive index of the encapsulant layer

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and lens array

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, which was rarely concerned so far. Optical simulations based on a Monte Carlo ray tracing method, and experiments were conducted to investigate the effect of

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and

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on the LEE of COB-LEDs with millilens array. The simulated results show that the TIR at chip-encapsulant, encapsulant-lens, and lens-air interfaces can be significantly diminished by regulating the

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e
n
c
a
p

and

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, and the LEE of COB-LEDs decreases as the refractive difference of encapsulant layer and lens array

|

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s

−

n

e
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|

increases. Compared to the COB-LEDs with only a flat encapsulant layer, the LEEs of blue and white COB-LEDs with

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=

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=

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O

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are enhanced by 246.2% and 50.6%, where

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is the refractive index of the top layer of the conventional LED chip. The experimental results agree well with the simulated results with normalized LEE deviation within 7.3%.
Over 10  W linearly polarized supercontinuum directly produced in an erbium-doped fiber MOPA seeded with stretched soliton
Authors: Shen Rong , Fang Hong , Zhao Junqing , Ouyang Deqin , Wang Meng , Wu Xu , Ruan Shuangchen
Published: December 2020

We experimentally achieve over 10 W linearly polarized supercontinuum (SC) generation in a polarization-maintaining (PM) erbium-doped fiber (EDF) master oscillator power-amplifier (MOPA). The house-built PM seeding EDF laser can deliver

∼

209

f
s

soliton around

∼

1563.7

n
m

, which is then stretched to

>

15

p
s

using a long piece of normal-dispersion fiber. The wideband spectrum of the ultrashort seeding soliton facilitates the further spectral broadening with nonlinear effects. The soliton stretching decelerates the peak power increase, thus facilitating higher amplified average power. After several stages of pre-amplification, the stretched soliton is fed into the main amplifier constructed with PM large mode area fibers. The output average power is finally amplified to

∼

11.51

W

. The corresponding spectrum spans from

∼

1450

to

∼

2200

n
m

, indicating that SC is formed due to the induced strong nonlinear effects. The polarization extinction ratio at the output reaches over 18 dB. The PM characteristic potentially enhances the system’s resistance to environmental disturbances and eliminates instabilities relating to polarization-mode coupling. Our result represents, so far, the highest SC power directly produced in an EDF MOPA, to the best of our knowledge, especially in a linearly polarized manner. This also suggests a scheme for powerful SC generation that employs direct laser diode pumping and duration-managed pulse seeding.
Feasible time-bin entanglement purification based on sum-frequency generation
Authors: Yan Pei-Shun , Zhou Lan , Zhong Wei , Sheng Yu-Bo
Published: December 2020

High quality time-bin entanglement is widely exploited to achieve the purposes of fundamental tests of physics and the implementation of quantum communication protocols both in free space and optical fiber propagation. However, the imperfect approaches of generating time-bin entangled state will degrade its quality and limit its practical application. Entanglement purification is to distill high quality entangled states from low quality entangled states. In this paper, we present the first entanglement purification protocol (EPP) for time-bin entanglement. We first explain this EPP for two-photon time-bin entangled state and then extend it to the system of multi-photon time-bin entangled state. We also design a possible realization of this EPP with practical spontaneous parametric down conversion (SPDC) source. Differ from the conventional EPPs, this EPP does not require the sophisticated controlled-not (CNOT) gate or similar operations, and it uses the feasible sum-frequency generation (SFG) to perform the purification. Moreover, the double-pair noise emitted from the SPDC source can be eliminated automatically which is the other advantage of this EPP. If we combine with the faithful entanglement swapping, this EPP may have potential to be a part of full quantum repeaters.
FleXCT: a flexible X-ray CT scanner with 10 degrees of freedom
Authors: Samber Björn De , Renders Jens , Elberfeld Tim , Maris Yves , Sanctorum Jonathan , Six Nathanaël , Liang Zhihua , Beenhouwer Jan De , Sijbers Jan
Published: December 2020

Laboratory based X-ray micro-CT is a non-destructive testing method that enables three dimensional visualization and analysis of the internal and external morphology of samples. Although a wide variety of commercial scanners exist, most of them are limited in the number of degrees of freedom to position the source and detector with respect to the object to be scanned. Hence, they are less suited for industrial X-ray imaging settings that require advanced scanning modes, such as laminography, conveyor belt scanning, or time-resolved imaging (4DCT). We introduce a new X-ray scanner FleXCT that consists of a total of ten motorized axes, which allow a wide range of non-standard XCT scans such as tiled and off-centre scans, laminography, helical tomography, conveyor belt, dynamic zooming, and X-ray phase contrast imaging. Additionally, a new software tool ‘FlexRayTools’ was created that enables reconstruction of non-standard XCT projection data of the FleXCT instrument using the ASTRA Toolbox, a highly efficient and open source set of tools for tomographic projection and reconstruction.
Matrix optics representation and imaging analysis of a light-field near-eye display
Authors: Yao Cheng , Cheng Dewen , Wang Yongtian
Published: December 2020

Integral-imaging-based (InI-based) light-field near-eye display (LF-NED) is an effective way to relieve vergence-accommodation conflict (VAC) in applications of virtual reality (VR) and augmented reality (AR). Lenslet arrays are often used as spatial light modulator (SLM) in such systems. However, the conflict between refocusing on a virtual object point from the light-field image (LF image) and focusing on the image plane of the lenslets leads to degradation of the viewing effect. Thus, the light field (LF) cannot be accurately restored. In this study, we introduce matrix optics and build a parameterized model of a lenslet-array-based LF-NED with general applicability, based on which the imaging process is derived, and the performance of the system is analyzed. A lenslet-array-based LF-NED optical model is embodied in LightTools to verify the theoretical model. The simulations prove that the model we propose and the conclusions about it are consistent with the simulation results. Thus, the model can be used as the theoretical basis for evaluating the primary performance of an InI-based LF-NED system.
Impact of laser frequency noise on high-extinction optical modulation
Authors: West Gavin N. , Loh William , Kharas Dave , Ram Rajeev J.
Published: December 2020

In present literature on integrated modulation and filtering, limitations in the extinction ratio are dominantly attributed to a combination of imbalance in interfering wave amplitude, instability of control signals, stray light (e.g., in the cladding), or amplified spontaneous emission from optical amplifiers. Here we show that the existence of optical frequency noise in single longitudinal mode lasers presents an additional limit to the extinction ratio of optical modulators. A simple frequency-domain model is used to describe a linear optical system’s response in the presence of frequency noise, and an intuitive picture is given for systems with arbitrary sampling time. Understanding the influence of frequency noise will help guide the design choices of device and system engineers and offer a path toward even higher-extinction optical modulators.
Hydrogel based Fabry-Pérot cavity for a pH sensor
Authors: Noman Abdullah Al , Dash Jitendra Narayan , Cheng Xin , Leong Chern Yang , Tam Hwa-Yaw , Yu Changyuan
Published: December 2020

A simple, reliable, and quick reactive Fabry-Pérot (FP) structure-based fiber optic pH sensor is presented. The pH-sensitive hydrogel and single-mode fiber (SMF) are placed inside a fused silica capillary to form the FP cavity. The gel thickness is characterized by the spin coating method with respect to different spin speeds. The proposed sensor shows a pH sensitivity of 0.30 nm/pH along with a fast response time of 15 s to 20 s for different pH solvents in the acidic range. Also, the temperature sensitivity of the FPI sensor is found to be -0.56 nm/°C.
Proposal for noise-free visible-telecom quantum frequency conversion through third-order sum and difference frequency generation
Authors: Lu Xiyuan , Moille Gregory , Rao Ashutosh , Srinivasan Kartik
Published: December 2020

Quantum frequency conversion (QFC) between the visible and telecom is a key to connect quantum memories in fiber-based quantum networks. Current methods for linking such widely separated frequencies, such as sum/difference frequency generation and four-wave mixing Bragg scattering, are prone to broadband noise generated by the pump laser(s). To address this issue, we propose to use third-order sum/difference frequency generation (TSFG/TDFG) for an upconversion/downconversion QFC interface. In this process, two long wavelength pump photons combine their energy and momentum to mediate frequency conversion across the large spectral gap between the visible and telecom bands, which is particularly beneficial from the noise perspective. We show that waveguide-coupled silicon nitride microring resonators can be designed for efficient QFC between 606 and 1550 nm via a 1990 nm pump through TSFG/TDFG. We simulate the device dispersion and coupling, and from the simulated parameters, estimate that the frequency conversion can be efficient (

) at 50 mW pump power. Our results suggest that microresonator TSFG/TDFG is promising for compact, scalable, and low-power QFC across large spectral gaps.
152 km-range single-ended distributed acoustic sensor based on inline optical amplification and a micromachined enhanced-backscattering fiber
Authors: Masoudi Ali , Beresna Martynas , Brambilla Gilberto
Published: December 2020

In this Letter, a distributed acoustic sensor (DAS) with a sensing range in excess of 150 km is reported. This extended sensing range is achieved by adding a low-loss enhanced-backscattering fiber at the far end of a standard single-mode fiber. A conventional DAS system along with inline optical amplifiers are used to interrogate the sensing fiber. The combined system exhibits a minimum detectable strain of 40 n

ε

at 1 Hz over a spatial resolution of 5 m.
Non-invasive optical imaging using the extension of the Fourier–domain shower–curtain effect
Authors: Xie Xiangsheng , He Qiangzhi , Liu Yikun , Liang Haowen , Zhou JianYing
Published: December 2020

Optical imaging for non-self-luminous objects surrounded by complex scattering environments is scientifically challenging and technologically important. We propose a non-invasive imaging method by externally sending the illuminating light through the scattering medium and by detecting and analyzing the speckle patterns. The imaging of the object is recovered by extending the application scope of the Fourier–domain shower–curtain effect. It is found that the imaging depth is substantially extended and that faster imaging restoration is realized with the improved illumination scheme assisted with optical lenses, hence making it possible to apply the non-invasive optical imaging technique for practical applications.
Prior expectations evoke stimulus-specific activity in the deep layers of the primary visual cortex
Authors: Aitken Fraser , Menelaou Georgios , Warrington Oliver , Koolschijn Renée S. , Corbin Nadège , Callaghan Martina F. , Kok Peter
Published: December 2020

The way we perceive the world is strongly influenced by our expectations. In line with this, much recent research has revealed that prior expectations strongly modulate sensory processing. However, the neural circuitry through which the brain integrates external sensory inputs with internal expectation signals remains unknown. In order to understand the computational architecture of the cortex, we need to investigate the way these signals flow through the cortical layers. This is crucial because the different cortical layers have distinct intra- and interregional connectivity patterns, and therefore determining which layers are involved in a cortical computation can inform us on the sources and targets of these signals. Here, we used ultra-high field (7T) functional magnetic resonance imaging (fMRI) to reveal that prior expectations evoke stimulus-specific activity selectively in the deep layers of the primary visual cortex (V1). These findings are in line with predictive processing theories proposing that neurons in the deep cortical layers represent perceptual hypotheses and thereby shed light on the computational architecture of cortex.
Real-time structural motif searching in proteins using an inverted index strategy
Authors: Bittrich Sebastian , Burley Stephen K. , Rose Alexander S.
Published: December 2020

Biochemical and biological functions of proteins are the product of both the overall fold of the polypeptide chain, and, typically, structural motifs made up of smaller numbers of amino acids constituting a catalytic center or a binding site that may be remote from one another in amino acid sequence. Detection of such structural motifs can provide valuable insights into the function(s) of previously uncharacterized proteins. Technically, this remains an extremely challenging problem because of the size of the Protein Data Bank (PDB) archive. Existing methods depend on a clustering by sequence similarity and can be computationally slow. We have developed a new approach that uses an inverted index strategy capable of analyzing >170,000 PDB structures with unmatched speed. The efficiency of the inverted index method depends critically on identifying the small number of structures containing the query motif and ignoring most of the structures that are irrelevant. Our approach (implemented at motif.rcsb.org) enables real-time retrieval and superposition of structural motifs, either extracted from a reference structure or uploaded by the user. Herein, we describe the method and present five case studies that exemplify its efficacy and speed for analyzing 3D structures of both proteins and nucleic acids.
Common maternal and fetal genetic variants show expected polygenic effects on risk of small- or large-for-gestational-age (SGA or LGA), except in the smallest 3% of babies
Authors: Beaumont Robin N. , Kotecha Sarah J. , Wood Andrew R. , Knight Bridget A. , Sebert Sylvain , McCarthy Mark I. , Hattersley Andrew T. , Järvelin Marjo-Riitta , Timpson Nicholas J. , Freathy Rachel M. , Kotecha Sailesh
Published: December 2020

Babies born clinically Small- or Large-for-Gestational-Age (SGA or LGA; sex- and gestational age-adjusted birth weight (BW) <10th or >90th percentile, respectively), are at higher risks of complications. SGA and LGA include babies who have experienced environment-related growth-restriction or overgrowth, respectively, and babies who are heritably small or large. However, the relative proportions within each group are unclear. We assessed the extent to which common genetic variants underlying variation in birth weight influence the probability of being SGA or LGA. We calculated independent fetal and maternal genetic scores (GS) for BW in 11,951 babies and 5,182 mothers. These scores capture the direct fetal and indirect maternal (via intrauterine environment) genetic contributions to BW, respectively. We also calculated maternal fasting glucose (FG) and systolic blood pressure (SBP) GS. We tested associations between each GS and probability of SGA or LGA. For the BW GS, we used simulations to assess evidence of deviation from an expected polygenic model.

Higher BW GS were strongly associated with lower odds of SGA and higher odds of LGA (ORfetal = 0.75 (0.71,0.80) and 1.32 (1.26,1.39); ORmaternal = 0.81 (0.75,0.88) and 1.17 (1.09,1.25), respectively per 1 decile higher GS). We found evidence that the smallest 3% of babies had a higher BW GS, on average, than expected from their observed birth weight (assuming an additive polygenic model: Pfetal = 0.014, Pmaternal = 0.062). Higher maternal SBP GS was associated with higher odds of SGA P = 0.005.

We conclude that common genetic variants contribute to risk of SGA and LGA, but that additional factors become more important for risk of SGA in the smallest 3% of babies.
CAF-1 and Rtt101p function within the replication-coupled chromatin assembly network to promote H4 K16ac, preventing ectopic silencing
Authors: Young Tiffany J. , Cui Yi , Pfeffer Claire , Hobbs Emilie , Liu Wenjie , Irudayaraj Joseph , Kirchmaier Ann L.
Published: December 2020

Replication-coupled chromatin assembly is achieved by a network of alternate pathways containing different chromatin assembly factors and histone-modifying enzymes that coordinate deposition of nucleosomes at the replication fork. Here we describe the organization of a CAF-1-dependent pathway inSaccharomyces cerevisiaethat regulates acetylation of histone H4 K16. We demonstrate factors that function in this CAF-1-dependent pathway are important for preventing establishment of silenced states at inappropriate genomic sites using a crippledHMRlocus as a model, while factors specific to other assembly pathways do not. This CAF-1-dependent pathway required the cullin Rtt101p, but was functionally distinct from an alternate pathway involving Rtt101p-dependent ubiquitination of histone H3 and the chromatin assembly factor Rtt106p. A major implication from this work is that cells have the inherent ability to create different chromatin modification patterns during DNA replication via differential processing and deposition of histones by distinct chromatin assembly pathways within the network.
3D genome evolution and reorganization in the Drosophila melanogaster species group
Authors: Torosin Nicole S. , Anand Aparna , Golla Tirupathi Rao , Cao Weihuan , Ellison Christopher E.
Published: December 2020

Topologically associating domains, or TADs, are functional units that organize chromosomes into 3D structures of interacting chromatin. TADs play an important role in regulating gene expression by constraining enhancer-promoter contacts and there is evidence that deletion of TAD boundaries leads to aberrant expression of neighboring genes. While the mechanisms of TAD formation have been well-studied, current knowledge on the patterns of TAD evolution across species is limited. Due to the integral role TADs play in gene regulation, their structure and organization is expected to be conserved during evolution. However, more recent research suggests that TAD structures diverge relatively rapidly. We use Hi-C chromosome conformation capture to measure evolutionary conservation of whole TADs and TAD boundary elements betweenD. melanogasterandD. triauraria, two early-branching species from themelanogasterspecies group which diverged ∼15 million years ago. We find that the majority of TADs have been reorganized since the common ancestor ofD. melanogasterandD. triauraria, via a combination of chromosomal rearrangements and gain/loss of TAD boundaries. TAD reorganization between these two species is associated with a localized effect on gene expression, near the site of disruption. By separating TADs into subtypes based on their chromatin state, we find that different subtypes are evolving under different evolutionary forces. TADs enriched for broadly expressed, transcriptionally active genes are evolving rapidly, potentially due to positive selection, whereas TADs enriched for developmentally-regulated genes remain conserved, presumably due to their importance in restricting gene-regulatory element interactions. These results provide novel insight into the evolutionary dynamics of TADs and help to reconcile contradictory reports related to the evolutionary conservation of TADs and whether changes in TAD structure affect gene expression.
Antenatal corticosteroid administration and early school age child development: A regression discontinuity study in British Columbia, Canada
Authors: Hutcheon Jennifer A. , Harper Sam , Liauw Jessica , Skoll M. Amanda , Srour Myriam , Strumpf Erin C.
Published: December 2020

Background

There are growing concerns that antenatal corticosteroid administration may harm children’s neurodevelopment. We investigated the safety of antenatal corticosteroid administration practices for children’s overall developmental health (skills and behaviors) at early school age.

Methods and findings

We linked population health and education databases from British Columbia (BC), Canada to identify a cohort of births admitted to hospital between 31 weeks, 0 days gestation (31+0 weeks), and 36+6 weeks, 2000 to 2013, with routine early school age child development testing. We used a regression discontinuity design to compare outcomes of infants admitted just before and just after the clinical threshold for corticosteroid administration of 34+0 weeks. We estimated the median difference in the overall Early Development Instrument (EDI) score and EDI subdomain scores, as well as risk differences (RDs) for special needs designation and developmental vulnerability (<10th percentile on 2 or more subdomains). The cohort included 5,562 births admitted between 31+0 and 36+6 weeks, with a median EDI score of 40/50. We found no evidence that antenatal corticosteroid administration practices were linked with altered child development at early school age: median EDI score difference of −0.5 [95% CI: −2.2 to 1.7] (p = 0.65), RD per 100 births for special needs designation −0.5 [−4.2 to 3.1] (p = 0.96) and for developmental vulnerability of 3.9 [95% CI:−2.2 to 10.0] (p = 0.24). A limitation of our study is that the regression discontinuity design estimates the effect of antenatal corticosteroid administration at the gestational age of the discontinuity, 34 + 0 weeks, so our results may become less generalisable as gestational age moves further away from this point.

Conclusions

Our study did not find that that antenatal corticosteroid administration practices were associated with child development at early school age. Our findings may be useful for supporting clinical counseling about antenatal corticosteroids administration at late preterm gestation, when the balance of harms and benefits is less clear.
Diagnostic accuracy of an in-house Scrub Typhus enzyme linked immunoassay for the detection of IgM and IgG antibodies in Laos
Authors: Elders Philip N. D. , Dhawan Sandhya , Tanganuchitcharnchai Ampai , Phommasone Koukeo , Chansamouth Vilada , Day Nicholas P. J. , Garcia-Rivera Jose A. , Hertz Jeffrey C. , Mayxay Mayfong , Vongsouvath Manivanh , Dubot-Pérès Audrey , Robinson Matthew T. , Newton Paul N. , Blacksell Stuart D.
Published: December 2020

Scrub typhus is a major cause of morbidity and mortality in Southeast Asia. Diagnosis of scrub typhus is difficult due to a lack of accessible validated diagnostic tools. Despite its objectivity, the diagnostic accuracy of ELISA tests is influenced by methodological and patient factors. This study aims to evaluate the performance of a novel in-house ELISA developed in the Mahidol Oxford Tropical Medicine Research Unit (MORU) for anti-scrub typhus group IgM and IgG compared to the “gold standard” reference IFA and PCR, and to determine whether the in-house ELISA can be used as a seroepidemiological screening tool and/or stand-alone test for scrub typhus. A total of 1,976 admission and 1,438 participant follow-up sera collected in the Lao PDR (Laos) were tested with ELISA for IgM and IgG. Samples with an ELISA OD≥0.50 were tested with IFA for IgM and/or IgG. A strong positive relationship was present between ELISA ODs and IFA titers for admission IgM (r2: 0.70, p <0.005) and IgG (r2: 0.76, p<0.005), and for follow-up IgM and IgG (both r2: 0.76, p<0.005) samples. The best compromise between sensitivity and specificity for the ELISA OD cut-off is likely to be between 0.8–1.0 for IgM antibodies and 1.2–1.8 for IgG antibodies. These results demonstrate that the diagnostic accuracy of the MORU in-house scrub typhus group ELISA is comparable to that of IFA, with similar results as reported for the commonly used InBios Scrub Typhus Detect ELISA, validating the use of the in-house ELISA. The optimal ELISA cut-off would depend on the use of the test, and the desired sensitivity and specificity. Further studies are required to authenticate the use of these cut-offs in other endemic regions. This in-house ELISA has the potential to replace the imperfect IFA, which could ultimately reduce the burden of scrub typhus by improving the rate of scrub typhus diagnoses in endemic low-resource areas.
Risk assessment and evaluation of China’s policy to prevent COVID-19 cases imported by plane
Authors: Pan Jinhua , Tian Jie , Xiong Haiyan , Liu Zhixi , Yao Ye , Wang Yesheng , Zhu Wenlong , Wang Yue , Wang Weibing
Published: December 2020

As of October 5, 2020, China has reported 2,921 cases imported from overseas. Assessing the effectiveness of China's current policies on imported cases abroad is very important for China and other countries that are facing or will face overseas imported cases. In April, we used a susceptible-exposed-infectious-recovered metapopulation model to simulate the epidemic in seven foreign countries, China and the three Chinese key cities. Based on the model outside China, we estimated the proportion of people in incubation period and calculated the risk indexes for Chinese cities through analyzing aviation traffic data from these countries. Based on the model in China and the three key cities, we collected information on control measures and quantified the effectiveness of implementing the current policies at different times and intensities. Our model results showed that Shanghai, Beijing, Qingdao, Guangzhou, and Tianjin have the top five risk indexes. As of April 20, 2020, under current measures, the number of confirmed cases could be reduced by 99% compared with no air traffic restrictions and isolation measures; the reduction could be 93% with isolation of passengers only from key countries. If the current policy were postponed for 7, 10, or 20 days, the increase in the number of confirmed cases would be 1,329, 5,524, and 779,245 respectively, which is 2.1, 5.7, and 662.9 times the number of confirmed cases under current measures. Our research indicates that the importation control measures currently taken by China were implemented at an appropriate time to prevent the epidemic spreading and have achieved relatively good control results. However, it is necessary to remain vigilant; otherwise, another outbreak peak could occur.
Sodium-bile acid co-transporter is crucial for survival of a carcinogenic liver fluke Clonorchis sinensis in the bile
Authors: Dai Fuhong , Yoo Won Gi , Lu Yanyan , Song Jin-Ho , Lee Ji-Yun , Byun Youngro , Pak Jhang Ho , Sohn Woon-Mok , Hong Sung-Jong
Published: December 2020

The liver fluke Clonorchis sinensis inhabits the bile ducts, where bile concentration disparities across the fluke cell membrane can cause bile intoxication. Sodium-bile acid co-transporter (SBAT) plays a crucial role in bile acid recycling. The process by which SBAT imports bile acids is electrically coupled to sodium ion co-transportation. Here, we report that the SBAT of C. sinensis (CsSBAT) is involved in bile acid transportation. CsSBAT cDNA encoded a putative polypeptide of 546 amino acid residues. Furthermore, CsSBAT consisted of ten putative transmembrane domains, and its 3D structure was predicted to form panel and core domains. The CsSBAT had one bile acid- and three Na+-binding sites, enabling coordination of a symport process. CsSBAT was mainly localized in the mesenchymal tissue throughout the fluke body and sparsely localized in the basement of the tegument, intestinal epithelium, and excretory bladder wall. Bile acid permeated into the adult flukes in a short time and remained at a low concentration level. Bile acid accumulated inside the mesenchymal tissue when CsSBAT was inhibited using polyacrylic acid–tetradeoxycholic acid conjugate. The accumulated bile acid deteriorated the C. sinensis adults leading to death. CsSBAT silencing shortened the lifespan of the fluke when it was placed into bile. Taken together, we propose that CsSBAT transports bile acids in the mesenchymal tissue and coordinate with outward transporters to maintain bile acid homeostasis of C. sinensis adults, contributing to C. sinensis survival in the bile environment.