bluuebunny/crossref_metadata_2025 huggingface dataset:
Aluminum-based concurrent photonic and plasmonic energy conversion driven by quasi-localized plasmon resonance
Authors: Chang Yin-Jung , Shih Ko-Han , Muthuramalingam Karthickraj
Published: November 2020

Plasmon-enhanced sensitive photodetection using plasmonic noble metals has been widely investigated; however, aluminum (Al)-based photoelectric conversion concurrently utilizing photonic and plasmonic approaches is less explored. Here, photodetection driven by quasi-localized plasmon resonance (QLPR) is investigated. Concurrent photonic and plasmonic contributions to strong absorption in the active region require delocalized, slow-propagating resonant electric field to occur around the peripheries of Al nano-structures and depend on the spatial distribution of diffraction efficiencies of all space harmonics. Efficiency limits are shown to be largely determined by the spatial degrees of freedom and the associated traveling distances of hot electrons during carrier transport. With strong absorption and relatively high reaching-emission probabilities structured in the same region, the measured responsivity and the external quantum efficiency of the fabricated device at 638.9 nm are 4.1889 μA/mW and 0.8129% at −0.485 V, respectively. Our results provide physical insights into related problems and may offer a route to more efficient, hot-carrier based photoelectric conversion devices.
Multiple Dirac points by high-order photonic bands in plasmonic-dielectric superlattices
Authors: Liu Zhenzhen , Wei Guochao , Zhang Dasen , Xiao Jun-Jun
Published: November 2020

The emergence of Dirac points (DPs) characterizes the topological phase transition and the gapless interface states in composite metal-dielectric metamaterials. In this work, we study a kind of compound plasmonic-dielectric periodic structure (PDPS) which sustains both plasmonic modes and multiple photonic modes. The structure has primitive cell consisting of four layers made from triple constituent components. Due to the generalized Su-Schrieffer-Heeger, DPs can emerge at the Brillouin zone center. More specifically, in weak plasmonic-photonic mode interaction regime, multiple DPs would emerge at the Brillouin zone center and edge due to the band folding, from the perspective of general effective medium. From the rigorous field analysis, the origin of these DPs is clearly demonstrated. These interleaved DPs behave as the intermediate transitions of the surface impedance for the PDPS and raise fully spanned topological interface states originated from 0 to 2nd-order photonic bands in the PDPS. The cases of combining our PDPS with either a plasmonic or dielectric homogenous medium are presented.
Laser wavelength metrology with low-finesse etalons and Bayer filters
Authors: Nicholas Porter J. , Jackson Jarom S. , Durfee Dallin S. , Sandberg Richard L.
Published: November 2020

We present a wavelength meter with picometer-scale resolution based on etaloning effects of inexpensive glass slides and the built-in color filters of a consumer grade CMOS camera. After calibrating the device to a commercial meter, we tested the device’s calibration stability using two tunable visible lasers for a period of over 16 days. The wavelength error over that entire period has a standard deviation of 5.29 parts per million (ppm) about a most probable error of 0.90 ppm. Within 24 hours of calibration, this improves to 0.04 ppm with a standard deviation of 3.94 ppm.
Efficient multi-watt 1720 nm ring-cavity Tm-doped fiber laser
Authors: Zhang Lu , Zhang Junxiang , Sheng Quan , Sun Shuai , Shi Chaodu , Fu Shijie , Bai Xiaolei , Fang Qiang , Shi Wei , Yao Jianquan
Published: November 2020

Using commercial Tm-doped silica fiber and 1570-nm in-band pump source, we demonstrated an efficient 1720-nm all-fiber laser with ring-cavity configuration. The theoretical model based on rate equations was built up to analyze the laser performance of Tm-doped fiber, which exhibits strong absorption in the 1.7-μm region. The results show that efficient laser operation can be achieved through the optimization of output coupling and the length of Tm-doped fiber. An experimental investigation was performed and agreed with the calculation. By using homemade couplers, we experimentally achieved 2.36-W laser output at 1720 nm under a 6-W launched pump. The slope efficiency with respect to the absorbed pump power and optical efficiency were 50.2% and 39.3%, respectively. Due to the employment of a ring resonator, a narrow laser linewidth of ∼4 GHz at maximum output power was observed.
Investigation of acoustic plasmons in vertically stacked metal/dielectric/graphene heterostructures for multiband coherent perfect absorption
Authors: Li Hongju , Zhang Yu , Xiao Haixiao , Qin Meng , Xia Shengxuan , Wang Lingling
Published: November 2020

Coherent absorption, as the time-reversed counterpart to laser, has been widely proposed recently to flexibly modulate light-matter interactions in two-dimensional materials. However, the multiband coherent perfect absorption (CPA) in atomically thin materials still has been elusive. We exploit the multiband CPA in vertically stacked metal/dielectric/graphene heterostructures via ultraconfined acoustic plasmons which can reduce the photon wavelength by a factor of about 70 and thus enable multiple-order resonances on a graphene ribbon of finite width. Under the illumination of two counter-propagating coherent beams, the two-stage coupling scheme is used for exciting multispectral acoustic plasmon resonances on the heterostructure simultaneously, thereby contributing to the ultimate multiband CPA in the mid-infrared region. The strong dependence of the nearly linear dispersion of acoustic plasmons on the chemical potential in graphene and the separation between the metal and the graphene allows the tunability in spectral positions of absorption peaks. Intriguingly, the absorption of each resonant peak is continuously tuned by varying the relative amplitude of two counter-propagating beams, and even their phase difference, respectively. The maximum modulation depth of 4.46*105 is observed. The scattering matrix is employed to demonstrate the principle of CPA and the finite-difference time-domain (FDTD) simulations are used for elucidating the flexible tunability. More importantly, the multiband coherent absorber is robust to the incident angle, and thus undoubtedly benefits extensive applications on optoelectronic and engineering technology areas for modulators and optical switches.
Effects of polarization aberrations in an unobscured off-axis space telescope on its PSF ellipticity
Authors: Luo Jing , He Xu , Fan Kuo , Zhang Xiaohui
Published: November 2020

Polarization aberrations exist in almost all astronomical telescopes. Polarization aberrations would bring about asymmetric apodization in the exit pupil, leading to asymmetric PSFs. The shape of PSFs is critical to telescopes that are used to detect weak gravitational lensing (WGL) in the universe. In this paper, polarization aberrations and their connections with PSF ellipticity in an unobscured off-axis space telescope are analyzed. Together with the Jones pupil, cumulative diattenuation and retardance maps of the telescope are obtained via polarization ray tracing. Due to asymmetric apodization caused by polarization aberrations, the ellipticities of all four PSF components are found to be greater than zero. The PSF ellipticity of the telescope over the full FOV is obtained. Results show that polarization aberrations change PSF ellipticity in different degrees at different FOVs. The maximum variance of PSF ellipticity induced by polarization aberrations is 7.5e–3 and the average value is 2.7e–3. In addition, interpolation errors of PSF ellipticity would also be affected by polarization aberrations. It is found that there are 405 FOV points (about 4% of all FOV points involved in the calculations) whose variances of interpolation errors caused by polarization aberrations are greater than 1.4e–4. According to the results shown in this paper, polarization aberrations of telescopes play a significant role in WGL measurements.
V- and W-band microwave generation and modulation using semiconductor lasers at period-one nonlinear dynamics
Authors: Tseng Chin-Hao , Lin Chun-Ting , Hwang Sheng-Kwang
Published: November 2020

Microwave generation and modulation over the V- and W-bands are investigated using a semiconductor laser subject to both comb-like optical injection and direct modulation. The former not only excites period-one (P1) nonlinear dynamics for tunable microwave generation but also improves the stability and purity of such generated microwaves. The latter upconverts data onto the generated microwaves by superimposing the data effectively only onto the lower oscillation sideband of the P1 dynamics, which prevents the data from dispersion-induced degradation over fiber distribution. As a result, microwaves that are continuously tunable from 40 to 110 GHz with a 3-dB linewidth of less than 1 Hz and with phase noise better than

−

95

d
B
c

/

H
z

at 10-kHz offset are generated. A bit-error ratio better than the forward error correction limit,

3.8
×

10

−
3

, is achieved for 12-Gb/s 16-quadrature amplitude modulation data after 25-km fiber distribution.
Dual-longitudinal-mode CW self-sweeping operation in Er-doped fiber laser
Authors: Kashirina Ekaterina K. , Lobach Ivan A. , Kablukov Sergey I.
Published: November 2020

A new type of sweeping operation—dual-mode continuous-wave (CW) self-sweeping—is demonstrated in an erbium-doped fiber laser with a sweeping range of 2.8 nm in a region of 1605 nm. The laser generates two adjacent longitudinal modes of equal intensity, but at some moments of time, one of the modes with lower frequency begins to vanish and a new one with even higher frequency starts to grow. As a result, the self-sweeping of lasing frequency with CW intensity dynamics is observed.
Tunable metamaterial-based silicon waveguide
Authors: Han Yuxi , Lin Jie , Lin Yu-Sheng
Published: November 2020

A tunable metamaterial (MM)-based silicon (Si) waveguide is presented that is composed of an MM nanodisk array on a Si-on insulator substrate. A significant modulation efficiency of transmission intensity could be realized by elevating individually or simultaneously the column number of MM nanodisks. For a convenient description, an MM-based Si waveguide with one, two, three, four, and five columns of MM nanodisks are denoted as MM-1, MM-2, MM-3, MM-4, and MM-5, respectively. Transmission intensity of MM-based Si waveguides could be switched between on and off states by driving different columns of MM nanodisks on the Si waveguide surface. Transmission intensities could be attenuated from 100% to 56%, 24%, 6%, 1%, and 0% for MM-1, MM-2, MM-3, MM-4, and MM-5, respectively, at the wavelength of 1.525 µm. Furthermore, the MM-5 device is exposed to an ambient environment with different refraction indices. It exhibits a linear relationship of resonance dips and refraction indexes. The proposed design of the MM-based Si waveguide provides potential possibilities in an optical switch, variable optical attenuator, and sensor applications.
Principle study of the europium vacancy color center in a diamond
Authors: Tan Xin , Liu Zhixin , Liu Zhiyu , Ren Yuan , Sun Shiyang , JIa Huiling
Published: November 2020

First-principles analyses are performed on the diamond europium vacancy (EuV) color center. Three different models indicate that the structure of the EuV color center contains a stable vacancy around the Eu atom. Energy band calculations show that the stable EuV color center has spin polarization and its spin-up energy level structure is highly suitable as a single-photon source. The zero-point transition energy is 1.989 eV (623 nm). The existence of metastable energy levels in the EuV is also predicted. Nitrogen atoms have a negative impact on the electronic structure of the EuV, in comparison to diamond color centers such as NE8 and TiV-N.
Temporal switching to extend the bandwidth of thin absorbers
Authors: Li Huanan , Alù Andrea
Published: November 2020

Wave absorption in time-invariant, passive thin films is fundamentally limited by a trade-off between bandwidth and overall thickness. In this work, we investigate the use of temporal switching to reduce signal reflections from a thin grounded slab over broader bandwidths. We extend quasi-normal mode theory to time switching, developing an ab initio formalism that can model a broad class of time-switched structures. Our formalism provides optimal switching strategies to maximize the bandwidth over which minimal reflection is achieved, showing promising prospects for time-switched nanophotonic and metamaterial systems to overcome the limits of time-invariant, passive structures.
Massively parallel amplitude-only Fourier neural network
Authors: Miscuglio Mario , Hu Zibo , Li Shurui , George Jonathan K. , Capanna Roberto , Dalir Hamed , Bardet Philippe M. , Gupta Puneet , Sorger Volker J.
Published: November 2020

Machine intelligence has become a driving factor in modern society.
However, its demand outpaces the underlying electronic technology due
to limitations given by fundamental physics, such as capacitive
charging of wires, but also by system architecture of storing and
handling data, both driving recent trends toward processor
heterogeneity. Task-specific accelerators based on free-space optics
bear fundamental homomorphism for massively parallel and real-time
information processing given the wave nature of light. However,
initial results are frustrated by data handling challenges and slow
optical programmability. Here we introduce a novel amplitude-only
Fourier-optical processor paradigm capable of processing large-scale

∼

(

1000

×

1000

)

matrices in a single time step and
100 µs-short latency. Conceptually, the information flow direction is
orthogonal to the two-dimensional programmable network, which
leverages

10

6

parallel channels of display
technology, and enables a prototype demonstration performing
convolutions as pixelwise multiplications in the Fourier domain
reaching peta operations per second throughputs. The required
real-to-Fourier domain transformations are performed passively by
optical lenses at zero-static power. We exemplary realize a
convolutional neural network (CNN) performing classification tasks on
2 megapixel large matrices at 10 kHz rates, which latency-outperforms
current graphic processing unit and phase-based display technology by
1 and 2 orders of magnitude, respectively. Training this optical
convolutional layer on image classification tasks and utilizing it in
a hybrid optical-electronic CNN, shows classification accuracy of 98%
(Modified National Institute of Standards and Technology) and 54%
(CIFAR-10). Interestingly, the amplitude-only CNN is inherently robust
against coherence noise in contrast to phase-based paradigms and
features a delay over 2 orders of magnitude lower than
liquid-crystal-based systems. Such an amplitude-only massively
parallel optical compute paradigm shows that the lack of phase
information can be accounted for via training, thus opening
opportunities for high-throughput accelerator technology for machine
intelligence with applications in network-edge processing, in data
centers, or in pre-processing information or filtering toward
near-real-time decision making.
Plasmonic evolution maps for planar metamaterials
Authors: Jiang Liyong , Jiang Jianli , Zhu Zebin , Yuan Guanghui , Kang Ming , Shen Ze Xiang
Published: November 2020

Understanding the mode’s origin in planar metamaterials is fundamental for related applications in nanophotonics and plasmonics. For complex planar metamaterials, conventional analysis that directly obtains the final charge/current distribution of a mode is usually difficult in helping to understand the mode’s origin. In this paper, we propose a mode evolution method (MEM) with a core analysis tool, i.e., plasmonic evolution maps (PEMs), to describe the mode evolution in several complementary planar metamaterials with designed plasmonic atoms/molecules. The PEMs could not only clearly explain a mode’s origin, but also reveal the role of a structure’s symmetry in the mode formation process. The MEM with PEMs can work as a simple, efficient, and universal approach for the mode analysis in different kinds of planar metamaterials.
Photonic two-particle quantum walks in Su–Schrieffer–Heeger lattices
Authors: Klauck Friederike , Heinrich Matthias , Szameit Alexander
Published: November 2020

We report on the experimental demonstration of two-photon quantum walks at the edge of a photonic Su–Schrieffer–Heeger lattice and compare them to those observed when launching photons at the edge of a homogeneous lattice. Whereas at the topological edge, one of the photons primarily remains close to the edge, both photons penetrate freely from the trivial edge into the bulk. This behavior manifests also in the average inter-particle distance, which is significantly larger at the topological edge. Hence, for a given propagation length, the entangled two-photon state launched at the topological edge extends over a wider domain of the lattice.
DeepPheno: Predicting single gene loss-of-function phenotypes using an ontology-aware hierarchical classifier
Authors: Kulmanov Maxat , Hoehndorf Robert
Published: November 2020

Predicting the phenotypes resulting from molecular perturbations is one of the key challenges in genetics. Both forward and reverse genetic screen are employed to identify the molecular mechanisms underlying phenotypes and disease, and these resulted in a large number of genotype–phenotype association being available for humans and model organisms. Combined with recent advances in machine learning, it may now be possible to predict human phenotypes resulting from particular molecular aberrations. We developed DeepPheno, a neural network based hierarchical multi-class multi-label classification method for predicting the phenotypes resulting from loss-of-function in single genes. DeepPheno uses the functional annotations with gene products to predict the phenotypes resulting from a loss-of-function; additionally, we employ a two-step procedure in which we predict these functions first and then predict phenotypes. Prediction of phenotypes is ontology-based and we propose a novel ontology-based classifier suitable for very large hierarchical classification tasks. These methods allow us to predict phenotypes associated with any known protein-coding gene. We evaluate our approach using evaluation metrics established by the CAFA challenge and compare with top performing CAFA2 methods as well as several state of the art phenotype prediction approaches, demonstrating the improvement of DeepPheno over established methods. Furthermore, we show that predictions generated by DeepPheno are applicable to predicting gene–disease associations based on comparing phenotypes, and that a large number of new predictions made by DeepPheno have recently been added as phenotype databases.
Antigenicity, stability, and reproducibility of Zika reporter virus particles for long-term applications
Authors: Whitbeck J. Charles , Thomas Anu , Kadash-Edmondson Kathryn , Grinyo-Escuer Ariadna , Stafford Lewis J. , Cheng Celine , Liao Grant C. , Holtsberg Frederick W. , Aman M. Javad , Simmons Graham , Davidson Edgar , Doranz Benjamin J.
Published: November 2020

The development of vaccines against flaviviruses, including Zika virus (ZIKV) and dengue virus (DENV), continues to be a major challenge, hindered by the lack of efficient and reliable methods for screening neutralizing activity of sera or antibodies. To address this need, we previously developed a plasmid-based, replication-incompetent DENV reporter virus particle (RVP) production system as an efficient and safe alternative to the Plaque Reduction Neutralization Test (PRNT). As part of the response to the 2015–2016 ZIKV outbreak, we developed pseudo-infectious ZIKV RVPs by modifying our DENV RVP system. The use of ZIKV RVPs as critical reagents in human clinical trials requires their further validation using stability and reproducibility metrics for large-scale applications. In the current study, we validated ZIKV RVPs using infectivity, neutralization, and enhancement assays with monoclonal antibodies (MAbs) and human ZIKV-positive patient serum. ZIKV RVPs are antigenically equivalent to live virus based on binding ELISA and neutralization results and are nonreplicating based on the results of live virus replication assays. We demonstrate reproducible neutralization titer data (NT50values) across different RVP production lots, volumes, time frames, and laboratories. We also show RVP stability across experimentally relevant time intervals and temperatures. Our results demonstrate that ZIKV RVPs provide a safe, high-throughput, and reproducible reagent for large-scale, long-term studies of neutralizing antibodies and sera, which can facilitate large-scale screening and epidemiological studies to help expedite ZIKV vaccine development.
Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India
Authors: Modgil Vinay , Mahindroo Jaspreet , Narayan Chandradeo , Kalia Manmohit , Yousuf Md , Shahi Varun , Koundal Meenakshi , Chaudhary Pankaj , Jain Ruby , Sandha Kawaljeet Singh , Tanwar Seema , Gupta Pratima , Thakur Kamlesh , Singh Digvijay , Gautam Neha , Kakkar Manish , Bharti Bhavneet , Mohan Balvinder , Taneja Neelam
Published: November 2020

Enteroaggregative Escherichia coli (EAEC) is an evolving enteric pathogen that causes acute and chronic diarrhea in developed and industrialized nations in children. EAEC epidemiology and the importance of atypical EAEC (aEAEC) isolation in childhood diarrhea are not well documented in the Indian setting. A comparative analysis was undertaken to evaluate virulence, phylogeny, and antibiotic sensitivity among typical tEAEC versus aEAEC. A total of 171 EAEC isolates were extracted from a broad surveillance sample of diarrheal (N = 1210) and healthy children (N = 550) across North India. Polymerase chain reaction (PCR) for the aggR gene (master regulator gene) was conducted to differentiate tEAEC and aEAEC. For 21 virulence genes, we used multiplex PCR to classify possible virulence factors among these strains. Phylogenetic classes were identified by a multiplex PCR for chuA, yjaA, and a cryptic DNA fragment, TspE4C2. Antibiotic susceptibility was conducted by the disc diffusion method as per CLSI guidelines. EAEC was associated with moderate to severe diarrhea in children. The prevalence of EAEC infection (11.4%) was higher than any other DEC group (p = 0.002). tEAEC occurrence in the diarrheal group was higher than in the control group (p = 0.0001). tEAEC strain harbored more virulence genes than aEAEC. astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination was present in more than 50% of strains. Also, 75.8% of EAEC strains were multidrug-resistant (MDR). Phylogroup D (43.9%) and B1 (39.4%) were most prevalent in the diarrheal and control group, respectively. Genetic analysis revealed EAEC variability; the comparison of tEAEC and aEAEC allowed us to better understand the EAEC virulence repertoire. Further microbiological and epidemiological research is required to examine the pathogenicity of not only typical but also atypical EAEC.
Vaccination with novel low-molecular weight proteins secreted from Trichinella spiralis inhibits establishment of infection
Authors: Srey Mellina T. , Taccogna Alessia , Oksov Yelena , Lustigman Sara , Tai Pei-Yi , Acord John , Selkirk Murray E. , Lamb Tracey J. , Guiliano David B.
Published: November 2020

Trichinella spiralismuscle stage larvae (mL1) produce excretory-secreted products (ESPs), a complex mixture of protein, which are believed to be important for establishing or maintaining an infection niche within skeletal muscle and the intestine. Studies of both whole ESPs and individual cloned proteins have shown that some ESPs are potent immunogens capable of eliciting protective immune responses. Here we describe two novel proteins,Secreted fromMuscle stageLarvae SML-4 and SML-5 which are 15 kDa and 12 kDa respectively. The genes encoding these proteins are highly conserved within the Trichinellids, are constituents of mL1 ESP and localized in the parasite stichosome. While SML-5 is only expressed in mL1 and early stages of adult nematode development, SML-4 is a tyvosylated glycoprotein also produced by adult nematodes, indicating it may have a function in the enteral phase of the infection. Vaccination with these proteins resulted in an impaired establishment of adult stages and consequently a reduction in the burden of mL1 in BALB/c mice. This suggests that both proteins may be important for establishment of parasite infection of the intestine and are prophylactic vaccine candidates.
From resistance to persistence: Insights of a mathematical model on the indiscriminate use of insecticide
Authors: Schechtman Helio , Valle Denise , Souza Max O.
Published: November 2020

The development of insecticide resistance is becoming a threat to many arboviruses control programs worldwide. While this has been attributed to the indiscriminate use of insecticide, a more theoretical study is apparently not available. Using in-silico experiments, we investigated the effects of two different policies: one used by the Brazilian Ministry of Health (which follows the World Health Organization protocol) and a more permissive one, akin to those employed by various gated communities and private companies. The results show that the public policy does not lead to resistance fixation. On the other hand, permissive application of adulticide, such as intensive domestic use mainly during epidemic periods, might lead to the fixation of a resistant population, even when resistance is associated with moderate fitness costs.
Overweight/obesity as the potentially most important lifestyle factor associated with signs of pneumonia in COVID-19
Authors: Sacco Vanessa , Rauch Barbara , Gar Christina , Haschka Stefanie , Potzel Anne L. , Kern-Matschilles Stefanie , Banning Friederike , Benz Irina , Meisel Mandy , Seissler Jochen , Lechner Andreas
Published: November 2020

Objective

The occurrence of pneumonia separates severe cases of COVID-19 from the majority of cases with mild disease. However, the factors determining whether or not pneumonia develops remain to be fully uncovered. We therefore explored the associations of several lifestyle factors with signs of pneumonia in COVID-19.

Methods

Between May and July 2020, we conducted an online survey of 201 adults in Germany who had recently gone through COVID-19, predominantly as outpatients. Of these, 165 had a PCR-based diagnosis and 36 had a retrospective diagnosis by antibody testing. The survey covered demographic information, eight lifestyle factors, comorbidities and medication use. We defined the main outcome as the presence vs. the absence of signs of pneumonia, represented by dyspnea, the requirement for oxygen therapy or intubation.

Results

Signs of pneumonia occurred in 39 of the 165 individuals with a PCR-based diagnosis of COVID-19 (23.6%). Among the lifestyle factors examined, only overweight/obesity was associated with signs of pneumonia (odds ratio 2.68 (1.29–5.59) p = 0.008). The observed association remained significant after multivariate adjustment, with BMI as a metric variable, and also after including the antibody-positive individuals into the analysis.

Conclusions

This exploratory study finds an association of overweight/obesity with signs of pneumonia in COVID-19. This finding suggests that a signal proportional to body fat mass, such as the hormone leptin, impairs the body’s ability to clear SARS-CoV-2 before pneumonia develops. This hypothesis concurs with previous work and should be investigated further to possibly reduce the proportion of severe cases of COVID-19.
A machine learning approach to predict ethnicity using personal name and census location in Canada
Authors: Wong Kai On , Zaïane Osmar R. , Davis Faith G. , Yasui Yutaka
Published: November 2020

Background

Canada is an ethnically-diverse country, yet its lack of ethnicity information in many large databases impedes effective population research and interventions. Automated ethnicity classification using machine learning has shown potential to address this data gap but its performance in Canada is largely unknown. This study conducted a large-scale machine learning framework to predict ethnicity using a novel set of name and census location features.

Methods

Using census 1901, the multiclass and binary class classification machine learning pipelines were developed. The 13 ethnic categories examined were Aboriginal (First Nations, Métis, Inuit, and all-combined)), Chinese, English, French, Irish, Italian, Japanese, Russian, Scottish, and others. Machine learning algorithms included regularized logistic regression, C-support vector, and naïve Bayes classifiers. Name features consisted of the entire name string, substrings, double-metaphones, and various name-entity patterns, while location features consisted of the entire location string and substrings of province, district, and subdistrict. Predictive performance metrics included sensitivity, specificity, positive predictive value, negative predictive value, F1, Area Under the Curve for Receiver Operating Characteristic curve, and accuracy.

Results

The census had 4,812,958 unique individuals. For multiclass classification, the highest performance achieved was 76% F1 and 91% accuracy. For binary classifications for Chinese, French, Italian, Japanese, Russian, and others, the F1 ranged 68–95% (median 87%). The lower performance for English, Irish, and Scottish (F1 ranged 63–67%) was likely due to their shared cultural and linguistic heritage. Adding census location features to the name-based models strongly improved the prediction in Aboriginal classification (F1 increased from 50% to 84%).

Conclusions

The automated machine learning approach using only name and census location features can predict the ethnicity of Canadians with varying performance by specific ethnic categories.
Effects of small-sided recreational team handball training on mechanical muscle function, body composition and bone mineralization in untrained young adults—A randomized controlled trial
Authors: Fristrup Bjørn , Krustrup Peter , Andersen Jesper L. , Hornstrup Therese , Løwenstein Frederik T. , Larsen Mikkel A. , Helge Jørn W. , Póvoas Susana C. A. , Aagaard Per
Published: November 2020

Prolonged physical inactivity in young adults may lead to deficiencies in musculoskeletal fitness, and thus a need exists to develop physical activity and exercise programmes that are effective of increasing musculoskeletal fitness. The aim of this study, therefore, was to investigate the effects of small-sided team handball training on lower limb muscle strength, postural balance and body composition in young adults. Twenty-six men and twenty-eight women were stratified for peak oxygen uptake (VO2peak) and body fat percentage and randomly allocated to either 12 wks of small-sided recreational team handball training (THG: 14 men and 14 women, age 24.1±2.6 yrs (mean±SD), VO2peak 39.8±5.9 ml/kg/min and body fat percentage 32.7±8.7%) or serving as non-exercising controls (CON: 12 men and 14 women, age 24.8±3.1 yrs, VO2peak 39.7±5.0 ml/kg/min, body fat percentage 31.7±9.7%). THG trained on average 1.8 times/week for 12 wks. At 0 and 12 wks, lower limb muscle strength, rate of force development (RFD), vertical jump height and power, postural balance, body composition and muscle biopsies were assessed. No training effects were observed for maximal isokinetic or isometric knee extensor strength, maximal vertical jump height or take-off power, fibre type distribution or capillarization. Late phase (RFD) increased (+7.4%, p<0.05) and postural sway excursion length was improved after training (-9%, p<0.05) in THG with no difference from CON (p>0.05). Further, THG demonstrated a decrease in body fat percentage (-3.7%) accompanied by increases in whole-body fat free mass (FFM) (+2.2%), leg FFM (+2.5%), total bone mineral content (BMC) (+1.1%), leg BMC (+1.2%), total hip bone mineral density (+1.6%) and hip T-score (+50%) which differed from CON (all p<0.05). In conclusion, recreational small-sided team handball training appears to effectively improve rapid force capacity, postural balance, lean and fat body mass and bone health in previously untrained young adults. The study was registered at ClinicalTrials.gov (NCT04247724).

ClinicalTrials.gov ID number: NCT04247724
Early indicators of intensive care unit bed requirement during the COVID-19 epidemic: A retrospective study in Ile-de-France region, France
Authors:   By the COVID-19 APHP-Universities-INRIA-INSERM Group
Published: November 2020

The aim of our retrospective study was to evaluate the earliest COVID19-related signal to anticipate requirements of intensive care unit (ICU) beds. Although the number of ICU beds is crucial during the COVID-19 epidemic, there is no recognized early indicator to anticipate it. In the Ile-de-France region, from February 20 to May 5, 2020, emergency medical service (EMS) calls and the response provided (ambulances) together the percentage of positive reverse transcriptase polymerase chain reaction (RT-PCR) tests, general practitioner (GP) and emergency department (ED) visits, and hospital admissions of COVID-19 patients were recorded daily and compared to the number of ICU patients. Correlation curve analysis was performed to determine the best correlation coefficient, depending on the number of days the indicator has been shifted. Primary endpoint was the number of ICU patients. EMS calls, percentage of positive RT-PCR tests, ambulances used, ED and GP visits of COVID-19 patients were strongly associated (R2 ranging between 0.79 to 0.99, all P<0.001) with COVID-19 ICU patients with an anticipation delay of 23, 15, 14, 13, and 12 days respectively. Hospitalization did not anticipate ICU bed requirement. A qualitative analysis of the onset of the second wave period of the epidemic (August 1 to September 15, 2020) in the same region provided similar results. The daily number of COVID19-related telephone calls received by the EMS and corresponding dispatch ambulances, and the proportion of positive RT-PCR tests were the earliest indicators of the number of COVID19 patients requiring ICU care during the epidemic crisis, rapidly followed by ED and GP visits. This information may help health authorities to anticipate a future epidemic, including a second wave of COVID19, or decide additional social measures.
Tissue expression of antigens of ABH blood groups in species of New World Monkeys (Aotus infulatus, Callithrix jacchus, Sapajus apella and Saimiri sciureus)
Authors: Aguiar Délia Cristina Figueira , Pereira Washington Luiz Assunção , de Matos Gyselly de Cássia Bastos , Marruaz da Silva Klena Sarges , de Loiola Rosane do Socorro Pompeu , Corvelo Tereza Cristina Oliveira
Published: November 2020

ABH antigens are histo-antigens, but were first described on the surface of human erythrocytes. They are found in those cells only in great apes and humans, while in more primitive animals they are found in tissues and body fluids. ABH antigens are mainly distributed in tissues that are in contact with the external environment and may serve as ligands for pathogens in tissues or block their connection. Description of the distribution of these molecules in non-human primate tissues is restricted to a few tissues and species. This paper describes the expression of human A, B and H type antigens in different organs from four species of New World Primates, obtained from the Centro Nacional de Primatas, as well as comparing that expression with what has been described for humans. In this study, although the tissue description of the antigens is similar to the genetic model for humans, some differences in expression between some organs from those species and those of humans were found. The differences occurred mainly in endodermal organs that have secretory functions and are probably under the control of the human-type FUT-2 enzyme. In the mesodermal-origin organs there was a reduction or absence of A and B antigen marking, particularly in the H precursor substance, indicating that those organs are under the control of the human-type FUT-1 enzyme. These findings have demonstrated that there is similar ABH antigen reactivity in tissue distribution between the species, although there are some species-specific cases.
The promise of an intersectoral network in enhancing the response to transgender survivors of sexual assault
Authors: Du Mont Janice , Hemalal Shilini , Kosa Sarah Daisy , Cameron Lee , Macdonald Sheila
Published: November 2020

Objectives

This study explores the promise of an intersectoral network in enhancing the response to transgender (trans) survivors of sexual assault.

Methods

One hundred and three representatives of healthcare and community organizations across Ontario, Canada were invited to participate in a survey. Respondents were asked to: 1) identify systemic challenges to supporting trans survivors, 2) determine barriers to collaborating across sectors, and 3) indicate how an intersectoral network might address these challenges and barriers. Descriptive statistics were used to summarize quantitative data and qualitative data were collated thematically.

Results

Sixty-seven representatives responded to the survey, for a response rate of 65%. Several themes capturing the challenges organizations face in supporting trans survivors were identified: Lack of knowledge and training among providers, Inadequate resources across organizations and institutions, and Limited access to and availability of appropriate services. Barriers to collaborating across sectors considered important by the overwhelming majority of respondents were: Lack of trans-positive service professionals (e.g., a paucity of sensitivity training), lack of resources (e.g., staff, staff time and workload, spaces to meet), and Institutional structures (e.g., oppressive policies, funding mandates). Four ways in which a network could address these challenges and barriers emerged from the data: Center the voices of trans communities in advocacy; Support competence of professionals to provide trans-affirming care; Provide the platform, strategies, and tools to aid in organizational change; and Create space for organizations to share ideas, goals, and resources.

Conclusion

Our findings deepen our understanding of important impediments to enhancing the response to trans survivors of sexual assault and the role networks of healthcare and community organizations can play in comprehensively responding to complex health and social problems.
Medical education in times of COVID-19: German students’ expectations – A cross-sectional study
Authors: Loda Teresa , Löffler Tobias , Erschens Rebecca , Zipfel Stephan , Herrmann-Werner Anne
Published: November 2020

Background

Since the COVID-19 pandemic has affected the education of medical students, medical faculties have faced the challenge of adapting instruction to digital platforms. Although medical students are willing to support pandemic response efforts, how the crisis will affect their medical training remains uncertain. Thus, in this study, we investigated the teaching- and learning-related stressors and expectations of medical students in Germany during the COVID-19 pandemic.

Methods

A cross-sectional survey was distributed online to undergraduate medical students at medical faculties in Germany. Students answered questions about COVID-19 and teaching (on a 7-point Likert scale from 0 (“not at all”) to 6 (“completely”)) and completed mental well-being measurements, including the State–Trait Anxiety Inventory (STAI), the Generalised Anxiety Disorder scale (GAD-7) and the Perceived Health Questionnaire (PHQ-9). Descriptive data analysis, a t-test and Pearson correlations were performed to process the data.

Results

Medical students felt well-informed about COVID-19 in general (M = 5.64, SD = 1.28) and in the medical context (M = 5.14, SD = 1.34) but significantly less informed about the pandemic in the academic context, M = 2.47, SD = 1.49, t(371) = 31.98, p < .001. Their distress levels were high (STAI: M = 45.12, SD = 4.73) and significantly correlated with the academic context (rp = .164, p < .01) but not their private lives. Concerning how they were taught, they most often expected online lectures (91.7%) and live broadcasts (67.2%) and less often expected innovative digital teaching strategies, including serious games (17.3%) and virtual-reality exercises (16.7%).

Discussion

Medical students seem to be aware of the COVID-19 pandemic and its consequences for academic and healthcare contexts. They also seem to think that their teachers will enhance their digital competencies during the pandemic. Therefore, faculties of medicine need to rapidly and adequately digitalise their approaches to teaching.
EGYVIR: An immunomodulatory herbal extract with potent antiviral activity against SARS-CoV-2
Authors: Roshdy Wael H. , Rashed Helmy A. , Kandeil Ahmed , Mostafa Ahmed , Moatasim Yassmin , Kutkat Omnia , Abo Shama Noura M. , Gomaa Mokhtar R. , El-Sayed Ibrahim H. , El Guindy Nancy M. , Naguib Amal , Kayali Ghazi , Ali Mohamed A.
Published: November 2020

Due to the challenges for developing vaccines in devastating pandemic situations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), developing and screening of novel antiviral agents are peremptorily demanded. Herein, we developed EGYVIR as a potent immunomodulatory herbal extract with promising antiviral activity against SARS-CoV-2. It constitutes of a combination of black pepper extract with curcumin extract. The antiviral effect of EGYVIR extract is attributed to the two key phases of the disease in severe cases. First, the inhibition of the nuclear translocation of NF-kβ p50, attenuating the SARS-CoV-2 infection-associated cytokine storm. Additionally, the EGYVIR extract has an in vitro virucidal effect for SARS-CoV-2. The in vitro study of EGYVIR extract against SARS-CoV-2 on Huh-7 cell lines, revealed the potential role of NF-kβ/TNFα/IL-6 during the infection process. EGYVIR antagonizes the NF-kβ pathway in-silico and in-vitro studies. Consequently, it has the potential to hinder the release of IL-6 and TNFα, decreasing the production of essential cytokines storm elements.
Taphonomic information from the modern vertebrate death assemblage of Doñana National Park, Spain
Authors: Domingo M. Soledad , Martín-Perea David M. , Badgley Catherine , Cantero Enrique , López-Guerrero Paloma , Oliver Adriana , Negro Juan José
Published: November 2020

Modern death assemblages provide insights about the early stages of fossilization and useful ecological information about the species inhabiting the ecosystem. We present the results of taphonomic monitoring of modern vertebrate carcasses and bones from Doñana National Park, a Mediterranean coastal ecosystem in Andalusia, Spain. Ten different habitats were surveyed. Half of them occur in active depositional environments (marshland, lake margin, river margin, beach and dunes). Most of the skeletal remains belong to land mammals larger than 5 kg in body weight (mainly wild and feral ungulates). Overall, the Doñana bone assemblage shows good preservation with little damage to the bones, partly as a consequence of the low predator pressure on large vertebrates. Assemblages from active depositional habitats differ significantly from other habitats in terms of the higher incidence of breakage and chewing marks on bones in the latter, which result from scavenging, mainly by wild boar and red fox. The lake-margin and river-margin death assemblages have high concentrations of well preserved bones that are undergoing burial and offer the greatest potential to produce fossil assemblages. The spatial distribution of species in the Doñana death assemblage generally reflects the preferred habitats of the species in life. Meadows seem to be a preferred winter habitat for male deer, given the high number of shed antlers recorded there. This study is further proof that taphonomy can provide powerful insights to better understand the ecology of modern species and to infer past and future scenarios for the fossil record.
The incidence of sore throat and group A streptococcal pharyngitis in children at high risk of developing acute rheumatic fever: A systematic review and meta-analysis
Authors: Pearce Sarah , Bowen Asha C. , Engel Mark E. , de la Lande Maya , Barth Dylan D.
Published: November 2020

Background

Group A streptococcal (GAS) pharyngitis has traditionally been considered the sole precursor of acute rheumatic fever (ARF). Evidence from Australia, however, suggests that GAS skin infections may contribute to the pathogenesis of ARF. A missing piece of evidence is the incidence of sore throat and GAS pharyngitis in this setting. We conducted a systematic review and meta-analysis of the incidence of sore throat and GAS pharyngitis in all children at risk of developing ARF.

Methods

Databases were systematically searched for studies reporting on the incidence of pharyngitis among children from low to upper-middle income countries, and Indigenous children living in high-income countries. Studies were subjected to data extraction by two independent reviewers. Following an assessment of the methodological quality of the studies, we extracted incidence rates (IRs) and conducted a meta-analysis. This systematic review is registered on PROSPERO (CRD42019113019).

Results

From 607 titles identified by the search, 11 articles met the predetermined inclusion criteria; ten studies reported IRs while for the remaining study, the incidence was calculated. The pooled incidence estimated for sore throat was 82.5 per 100 child-years (95% confidence interval [CI], 6.5 to 1044.4 per 100 child-years, I2 = 100%) and GAS pharyngitis was 10.8 per 100 child-years (95% CI, 2.3 to 50.0 per 100 child-years, I2 = 99.9%).

Conclusions

The pooled IRs for sore throat in children at risk of developing ARF were higher than rates reported in developed nations (32.70–40 per 100 child-years) and similar for GAS pharyngitis (12.8–14 per 100 years). The limited Australian data lend support to the need for further studies to inform the role of GAS pharyngitis in the development of ARF in Australian Indigenous children, so as to inform local primary prevention strategies for ARF and Rheumatic Heart Disease (RHD).
Adaptive volumetric light and atmospheric scattering
Authors: shihan Tan , jianwei Zhang , yi Lin , hong Liu , menglong Yang , wenyi Ge
Published: November 2020

An adaptive sampling-based atmospheric scattering and volumetric light framework for flight simulator (FS) is proposed to enhance the immersion and realism in real-time. The framework comprises epipolar sampling (ES), visible factor culling (VFC), interactive participating media density estimating (IPMDE). The main process of proposed architecture is as follows: the scene is divided into two levels according to the distance from the camera. In the high-level pipeline, the layer close to the camera, more samples, and smaller sampling step size is used to improve image quality. Further, the IPMDE method is designed to enhance realism by achieving interactivity with the participating media and multiple light sources. Further optimization is performed by the lookup table and 3D volumetric textures, by which we can compute the density of participating media and the scattering coefficient in parallel. In the low-level pipeline, when the samples are far away from the camera, its influence on the final output is also reduced, which results in fewer samples and a bigger sampling step size. The improved ES method further reduces the number of samples involved in ray marching using the features of epipolar geometry. It then generates global light effects and shadows of distant terrain. The VFC method uses an acceleration structure to quickly find the lit segments which eliminate samples blocked by obstacles. The experimental results demonstrate our architecture achieves a better sense of reality in real-time and is very suitable for FS.