bluuebunny/crossref_metadata_2025 huggingface dataset:
Magneto-transport phenomena of type-I multi-Weyl semimetals in co-planar setups
Authors: Nag Tanay , Nandy Snehasish
Published: October 2020

Having the chiral anomaly (CA) induced magneto-transport phenomena extensively studied in single Weyl semimetal as characterized by topological charge n = 1, we here address the transport properties in the context of multi-Weyl semimetals (m-WSMs) where n > 1. Using semiclassical Boltzmann transport formalism with the relaxation time approximation, we investigate several intriguing transport properties such as longitudinal magneto-conductivity (LMC), planar Hall conductivity (PHC), thermo-electric coefficients (TECs) and planar Nernst coefficient (PNC) for m-WSMs in the co-planar setups with external magnetic field, electric field and temperature gradient. Starting from the low-energy model, we show analytically that at zero temperature both LMC and PHC vary cubically with topological charge as n
3 while the finite temperature (T ≠ 0) correction is proportional to (n + n
2)T
2. Interestingly, we find that both the longitudinal and transverse TECs vary quadratically with topological charge as n
2 and the PNC is found to vary non-monotonically as a function of n. Our study hence clearly suggests that the inherent properties of m-WSMs indeed show up distinctly through the CA and the chiral magnetic effect induced transport coefficients in two different setups. Moreover, in order to obtain an experimentally realizable picture, we simultaneously verify our analytical findings through the numerical calculations using the lattice model of m-WSMs.
Combination therapy of biogenic C-dots and lysozyme for enhanced antibacterial and antibiofilm activity
Authors: Singh Anirudh , Verma Arushi , Singh Ruhar , Sahoo Amaresh Kumar , Samanta Sintu Kumar
Published: October 2020

Nearly 80% of human chronic infections are caused due to bacterial biofilm formation. The increased resistance against the conventional antimicrobial agents makes it difficult to treat the biofilm-related infections. The antibiotics resistance developed by planktonic cells has also become a major threat for human. Therefore, we have attempted here to develop an effective alternative strategy to overcome the issues of antibiotics resistance of bacteria. Upon synthesis, biogenic C-dots were combined with lysozymes which were further encapsulated into chitosan nanocarrier to form C-dots carrier (CDC). The as-synthesized C-dots were found irregular shaped and the average size of C-dots and CDC were 8 ± 2 nm and 450 ± 50 nm, respectively. To ensure secure and targeted delivery of C-dots and lysozyme we have employed chitosan, a biodegradable and natural biopolymer, as a delivery system. The study of time-dependent bacterial growth and flow cytometry analysis demonstrated that CDC can exhibit a synergistic bactericidal activity against the antibiotics resistant recombinant E. coli cells. Further, we have shown that the CDC could be a potent agent for both prevention of biofilm formation and eradication of preformed biofilm. In addition, we have observed that our drug delivery system is hemocompatible in nature making it suitable for in vivo applications. Therefore, we believe that the combination therapy of C-dots and lysozyme may be used as an excellent antibacterial and antibiofilm strategy.
Comparison of helium bubble formation in F82H, ODS, SIMP and T91 steels irradiated by Fe and He ions simultaneously*
Authors: Li Bingsheng , Yang Zhen , Xu Shuai , Wei Kongfang , Wang Zhiguang , Shen Tielong , Zhang Tongmin , Liao Qing
Published: October 2020

Ferritic-martensitic steels and ODS steels are attractive candidates for structural materials in advanced nuclear-power systems due to their good swelling resistance. Four kinds of steels, F82H, 15Cr-ODS, SIMP and T91, are investigated in this study. We take 6.4 MeV Fe3+ ions and energy-degraded 1.0 MeV He+ ions in the irradiation of these materials to 5 dpa and 60 appm He/dpa, 200 appm He/dpa and 600 appm He/dpa at 300 °C and 450 °C, respectively. The bubble formation and distribution are investigated by transmission electron microscopy (TEM). Formation and distribution of the bubbles in the four investigated steels are compared. The influence of irradiation temperature and helium injection ratio on bubble formation is discussed. It is found that there appears to be homogenously distributed bubbles at 300 °C irradiation while heterogeneously distributed bubbles at 450 °C irradiation.
Model predictive inverse method for recovering boundary conditions of two-dimensional ablation*
Authors: Wang Guang-Jun , Chen Ze-Hong , Zhang Guang-Xiang , Chen Hong
Published: October 2020

A model predictive inverse method (MPIM) is presented to estimate the time- and space-dependent heat flux on the ablated boundary and the ablation velocity of the two-dimensional ablation system. For the method, first of all, the relationship between the heat flux and the temperatures of the measurement points inside the ablation material is established by the predictive model based on an influence relationship matrix. Meanwhile, the estimation task is formulated as an inverse heat transfer problem (IHTP) with consideration of ablation, which is described by an objective function of the temperatures at the measurement point. Then, the rolling optimization is used to solve the IHTP to online estimate the unknown heat flux on the ablated boundary. Furthermore, the movement law of the ablated boundary is reconstructed according to the estimation of the boundary heat flux. The effects of the temperature measurement errors, the number of future time steps, and the arrangement of the measurement points on the estimation results are analyzed in numerical experiments. On the basis of the numerical results, the effectiveness of the presented method is clarified.
Atomic magnetometer with microfabricated vapor cells based on coherent population trapping*
Authors: Li Xiaojie , Shi Yue , Xue Hongbo , Ruan Yong , Feng Yanying
Published: October 2020

An atomic magnetometer based on coherent population trapping (CPT) resonances in microfabricated vapor cells is demonstrated. Fabricated by the micro-electro-mechanical-system (MEMS) technology, the cells are filled with Rb and Ne at a controlled pressure. An experimental apparatus is built for characterizing properties of microfabricated vapor cells via the CPT effects. The typical CPT linewidth is measured to be about 3 kHz (1.46 kHz with approximately zero laser intensity) for the rubidium D1 line at about 90 °C. The effects of pressure, temperature and laser intensity on CPT linewidth are studied experimentally. A closed-loop atomic magnetometer is finally finished with a sensitivity of 210.5 pT/Hz1/2 at 1 Hz bandwidth. This work paves the way for developing an integrated chip-scale atomic magnetometer in the future.
Majorana stellar representation for mixed-spin (s, 1/2) systems*
Authors: Su Yu-Guo , Yao Fei , Liang Hong-Bin , Che Yan-Ming , Fu Li-Bin , Wang Xiao-Guang
Published: October 2020

By describing the evolution of a quantum state with the trajectories of the Majorana stars on a Bloch sphere, Majorana’s stellar representation provides an intuitive geometric perspective to comprehend the quantum system with high-dimensional Hilbert space. However, the representation of a two-spin coupling system on a Bloch sphere has not been solved satisfactorily yet. Here, a practical method is presented to resolve the problem for the mixed-spin (s, 1/2) system and describe the entanglement of the system. The system can be decomposed into two spins: spin-(s + 1/2) and spin-(s – 1/2) at the coupling bases, which can be regarded as independent spins. Besides, any pure state may be written as a superposition of two orthonormal states with one spin-(s + 1/2) state and the other spin-(s – 1/2) state. Thus, the whole initial state can be regarded as a state of a pseudo spin-1/2. In this way, the mixed spin decomposes into three spins. Therefore, the state can be represented by (2s + 1) + (2s – 1) + 1 = 4s + 1 sets of stars on a Bloch sphere. Finally, some examples are given to show symmetric patterns on the Bloch sphere and unveil the properties of the high-spin system by analyzing the trajectories of the Majorana stars on the Bloch sphere.
Pulse-gated mode of commercial superconducting nanowire single photon detectors*
Authors: Liu Fan , Jiang Mu-Sheng , Lu Yi-Fei , Wang Yang , Bao Wan-Su
Published: October 2020

High detection efficiency and low intrinsic dark count rate are two advantages of superconducting nanowire single photon detectors (SNSPDs). However, the stray photons penetrated into the fiber would cause the extrinsic dark count rate, owing to the free running mode of SNSPDs. In order to improve the performance of SNSPDs in realistic scenarios, stray photons should be investigated and suppression methods should be adopted. In this study, we demonstrate the pulse-gated mode, with 500 kHz gating frequency, of a commercial SNSPD system for suppressing the response of stray photons about three orders of magnitude than its free-running counterpart on the extreme test conditions. When we push the gating frequency to 8 MHz, the dark count rate still keeps under 4% of free-running mode. In experiments, the intrinsic dark count rate is also suppressed to 4.56 × 10−2 counts per second with system detection efficiency of 76.4372%. Furthermore, the time-correlated single-photon counting analysis also approves the validity of our mode in suppressing the responses of stray photons.
Propagating Dirac plasmon polaritons in topological insulators
Authors: Wang Yong , Law Stephanie
Published: October 2020

We investigate the excitation of propagating Dirac plasmon polaritons (DPPs) in topological insulator (TI) thin films. A series of TI thin films were grown by molecular beam epitaxy. Periodic gold grating couplers with different periodicity were fabricated on the TI films to excite the propagating DPPs. A series of absorption peaks that shift with the grating periodicity were observed in Fourier transform infrared spectroscopy transmission scans. We have ruled out any source other than the excitation of propagating DPPs that could have caused the peaks to appear. The peak dispersion is consistent with theoretical predictions for coupled DPPs in TI thin films.
Effect of Ag nanoparticles on wafer-scale quasi-free-standing graphene characterization by surface enhanced Raman spectroscopy
Authors: Sun Li , Jiang Chao , Chen Xiufang , Yu Fapeng , Zhao Xian , Xu Xiangang , Xu Shicai
Published: October 2020

Quasi-free-standing graphene (QFSG) obtained by H intercalation on SiC (0001) substrate paves a new way for widening the applications in microelectronics field. In this work, the direct and efficient characterization of wafer-scale quasi-free-standing graphene on SiC was presented by Ag-assisting Raman spectroscopy. The Si-H peak existing at the interface between graphene and substrate was tested unambiguously. The effects of Ag distribution and particle size on Raman enhancement were clarified both theoretically and experimentally. It was found that relative larger Ag particles at aggregation area were accompanied with the better enhancement. Moreover, Raman mapping with Ag assisting was executed on QFSG obtained under different growth conditions and the corresponding QFSG coverages were evaluated effectively. The optimum H intercalation temperature was determined to be around 1000 °C with the coverage being 73%. This study would supply a new approach for uniform and wafer-scale QFSG fabrication.
Cyclosporin A and FGF signaling support the proliferation/survival of mouse primordial germ cell-like cells in vitro†
Authors: Ohta Hiroshi , Yabuta Yukihiro , Kurimoto Kazuki , Nakamura Tomonori , Murase Yusuke , Yamamoto Takuya , Saitou Mitinori
Published: October 2020

Primordial germ cells (PGCs) are the founding population of the germ cell lineage that undergo a multistep process to generate spermatozoa or oocytes. Establishing an appropriate culture system for PGCs is a key challenge in reproductive biology. By a chemical screening using mouse PGC-like cells (mPGCLCs), which were induced from mouse embryonic stem cells, we reported previously that forskolin and rolipram synergistically enhanced the proliferation/survival of mPGCLCs with an average expansion rate of ~20-fold. In the present study, we evaluated other chemicals or cytokines to see whether they would improve the current mPGCLC culture system. Among the chemicals and cytokines examined, in the presence of forskolin and rolipram, cyclosporin A (CsA) and fibroblast growth factors (FGFs: FGF2 and FGF10) effectively enhanced the expansion of mPGCLCs in vitro (~50-fold on average). During the expansion by CsA or FGFs, mPGCLCs comprehensively erased their DNA methylation to acquire a profile equivalent to that of gonadal germ cells in vivo, while maintaining their highly motile phenotype as well as their transcriptional properties as sexually uncommitted PGCs. Importantly, these mPGCLCs robustly contributed to spermatogenesis and produced fertile offspring. Furthermore, mouse PGCs (mPGCs) cultured with CsA ex vivo showed transcriptomes and DNA methylomes similar to those of cultured mPGCLCs. The improved culture system for mPGCLCs/mPGCs would be instructive for addressing key questions in PGC biology, including the mechanisms for germ cell migration, epigenetic reprogramming, and sex determination of the germline.
Componentwise approximate Bayesian computation via Gibbs-like steps
Authors: Clarté Grégoire , Robert Christian P , Ryder Robin J , Stoehr Julien
Published: October 2020

Approximate Bayesian computation methods are useful for generative models with intractable likelihoods. These methods are, however, sensitive to the dimension of the parameter space, requiring exponentially increasing resources as this dimension grows. To tackle this difficulty we explore a Gibbs version of the approximate Bayesian computation approach that runs component-wise approximate Bayesian computation steps aimed at the corresponding conditional posterior distributions, and based on summary statistics of reduced dimensions. While lacking the standard justifications for the Gibbs sampler, the resulting Markov chain is shown to converge in distribution under some partial independence conditions. The associated stationary distribution can further be shown to be close to the true posterior distribution, and some hierarchical versions of the proposed mechanism enjoy a closed-form limiting distribution. Experiments also demonstrate the gain in efficiency brought by the Gibbs version over the standard solution.
A Research Agenda for Urban Biodiversity in the Global Extinction Crisis
Authors: Knapp Sonja , Aronson Myla F J , Carpenter Ela , Herrera-Montes Adriana , Jung Kirsten , Kotze D Johan , La Sorte Frank A , Lepczyk Christopher A , MacGregor-Fors Ian , MacIvor J Scott , Moretti Marco , Nilon Charles H , Piana Max R , Rega-Brodsky Christine C , Salisbury Allyson , Threlfall Caragh G , Trisos Christopher , Williams Nicholas S G , Hahs Amy K
Published: October 2020

Rapid urbanization and the global loss of biodiversity necessitate the development of a research agenda that addresses knowledge gaps in urban ecology that will inform policy, management, and conservation. To advance this goal, we present six topics to pursue in urban biodiversity research: the socioeconomic and social–ecological drivers of biodiversity loss versus gain of biodiversity; the response of biodiversity to technological change; biodiversity–ecosystem service relationships; urban areas as refugia for biodiversity; spatiotemporal dynamics of species, community changes, and underlying processes; and ecological networks. We discuss overarching considerations and offer a set of questions to inspire and support urban biodiversity research. In parallel, we advocate for communication and collaboration across many fields and disciplines in order to build capacity for urban biodiversity research, education, and practice. Taken together we note that urban areas will play an important role in addressing the global extinction crisis.
Productivity divergence: state policy, corporate capture and labour power in the USA
Authors: Warner Mildred E , Xu Yuanshuo
Published: October 2020

What factors explain the divergence between returns to labour and overall productivity across US counties? We model the role of power at the subnational state level: Republican partisan control, corporate lobbying (measured by ALEC-sponsored bills) and labour power (unionisation). We find where state policy is captured by corporate interests, this undermines inclusive growth. Our hierarchical models use 2012 data for county areas in the continental USA and find labour returns are higher in states with more unionisation, but lower in states with Republican control and more corporate penetration of state legislatures. Labour and local government power have limited effect.
Rapid and Extraction-Free Detection of SARS-CoV-2 from Saliva by Colorimetric Reverse-Transcription Loop-Mediated Isothermal Amplification
Authors: Lalli Matthew A , Langmade Joshua S , Chen Xuhua , Fronick Catrina C , Sawyer Christopher S , Burcea Lauren C , Wilkinson Michael N , Fulton Robert S , Heinz Michael , Buchser William J , Head Richard D , Mitra Robi D , Milbrandt Jeffrey
Published: October 2020

Background

Rapid, reliable, and widespread testing is required to curtail the ongoing COVID-19 pandemic. Current gold-standard nucleic acid tests are hampered by supply shortages in critical reagents including nasal swabs, RNA extraction kits, personal protective equipment, instrumentation, and labor.

Methods

To overcome these challenges, we developed a rapid colorimetric assay using reverse-transcription loop-mediated isothermal amplification (RT-LAMP) optimized on human saliva samples without an RNA purification step. We describe the optimization of saliva pretreatment protocols to enable analytically sensitive viral detection by RT-LAMP. We optimized the RT-LAMP reaction conditions and implemented high-throughput unbiased methods for assay interpretation. We tested whether saliva pretreatment could also enable viral detection by conventional reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Finally, we validated these assays on clinical samples.

Results

The optimized saliva pretreatment protocol enabled analytically sensitive extraction-free detection of SARS-CoV-2 from saliva by colorimetric RT-LAMP or RT-qPCR. In simulated samples, the optimized RT-LAMP assay had a limit of detection of 59 (95% confidence interval: 44–104) particle copies per reaction. We highlighted the flexibility of LAMP assay implementation using 3 readouts: naked-eye colorimetry, spectrophotometry, and real-time fluorescence. In a set of 30 clinical saliva samples, colorimetric RT-LAMP and RT-qPCR assays performed directly on pretreated saliva samples without RNA extraction had accuracies greater than 90%.

Conclusions

Rapid and extraction-free detection of SARS-CoV-2 from saliva by colorimetric RT-LAMP is a simple, sensitive, and cost-effective approach with broad potential to expand diagnostic testing for the virus causing COVID-19.
Sleep pattern in the US and 16 European countries during the COVID-19 outbreak using crowdsourced smartphone data
Authors: Lee Paul H , Marek Jan , Nálevka Petr
Published: October 2020

Background

To stop the spread of the new coronavirus disease in 2019 (COVID-19), many countries had completely locked down. This lockdown restricted the everyday life of the affected residents and changed their mobility pattern, but its effects on sleep pattern were largely unknown.

Methods

Here, utilizing one of the largest crowdsourced database (Sleep as Android), we analyzed the sleep pattern of 25 217 users with 1 352 513 sleep records between 1 January and 29 April 2020 in the US and 16 European countries (Germany, UK, Spain, France, Italy, The Netherlands, Belgium, Hungary, Denmark, Finland, Norway, Czech, Sweden, Austria, Poland and Switzerland) with more than 100 records in all days of 2020.

Results

During the COVID-19 pandemic, the sleeping pattern before and after the country-level lockdown largely differed. The subjects increased their sleep duration by an average of 11.3 to 18.6 min on weekday nights, except Denmark (4.9 min) and Finland (7.1 min). In addition, subjects form all 16 European countries delayed their sleep onset from 10.7 min (Sweden) to 29.6 min (Austria).

Conclusion

During the COVID-19 pandemic, residents in the US and 16 European countries delayed their bedtime and slept longer than usual.
Benefits of robotically-assisted surgery for complex mitral valve repair
Authors: Fujita Tomoyuki , Kakuta Takashi , Kawamoto Naonori , Shimahara Yusuke , Yajima Shin , Tadokoro Naoki , Kitamura Soichiro , Kobayashi Junjiro , Fukushima Satsuki
Published: October 2020

OBJECTIVES

To determine whether robotic mitral valve repair can be applied to more complex lesions compared with minimally invasive direct mitral valve repair through a right thoracotomy.

METHODS

We enrolled 335 patients over a 9-year period; 95% of the robotic surgeries were performed after experience performing direct mitral valve repair.

RESULTS

The mean age in the robotic versus thoracotomy repair groups was 61 ± 14 vs 55 ± 11 years, respectively (P < 0.001); 97% vs 100% of the patients, respectively, had degenerative aetiologies. Repair complexity was simple in 106 (63%) vs 140 (84%), complex in 34 (20%) vs 20 (12%) and most complex in 29 (17%) vs 6 (4%) patients undergoing robotic versus thoracotomy repair, respectively. The average complexity score with robotic repair was significantly higher versus thoracotomy repair (P < 0.001). The robotic group underwent more chordal replacement using polytetrafluoroethylene and less resections. All patients underwent ring annuloplasty. Cross-clamp time did not differ between the groups, and no strokes or deaths occurred. More patients undergoing robotic repair underwent concomitant procedures versus the thoracotomy group (30% vs 14%, respectively; P < 0.001). The overall repair rate was 100%, with no early mortality or strokes in either group. Postoperative mean residual mitral regurgitation was 0.3 in both groups, and the mean pressure gradient through the mitral valve was 2.4 vs 2.7 mmHg (robotic versus thoracotomy repair, respectively; P = 0.031).

CONCLUSIONS

Robotic surgery can be applied to repair more complex mitral lesions, with excellent early outcomes.
Platforms as regulators
Authors: Dunne Niamh
Published: October 2020

The proposition that certain digital platforms act as ‘regulators’ within their own business models is a key pillar of the European Commission report on Competition Policy for the Digital Era, and the basis upon which its authors build a wide-ranging duty for dominant platforms to secure competition that is ‘fair, unbiased and pro-users’. This article seeks to shed light on this novel contention, exploring its meaning and the implications for platform operators. It considers the rationale provided within the report and compares the approach with established Article 102 TFEU case law, specifically the ‘special responsibility’ doctrine. Consideration is further given to whether the platforms-as-regulators notion aligns with alternative modes of regulation within the digital sphere. The aim is to explore whether this approach is coherent, and actually useful, as a means by which to frame and direct future enforcement against digital platforms.
Platymaia Miers, 1885 (Decapoda: Brachyura: Inachidae) can swim
Authors: Wicksten Mary K , Bingo Sarah
Published: October 2020

Two small spider crabs belonging to a species of Platymaia Miers, 1885 (Inachidae) were photographed by video feed from the Nautilus Exploration Program vessel Nautilus at 706 m off American Samoa, Pacific Ocean. Individuals swam by extending and contracting their very long, slender legs, rising above the sea floor by an estimated 2 m. These crabs do not have paddles on the fifth pereiopods, but they have setose legs. This is the first report of swimming in the wild for a crab of this genus.
Taxation of Digital Services Under Trade Agreements
Authors: Noonan Chris , Plekhanova Victoria
Published: October 2020

The digitalization of the economy combined with sophisticated tax planning has enabled some multinationals to avoid paying almost any income tax in most market jurisdictions from which they earn substantial profits. Faced with financial and political pressures to act, market states have sought to expand their tax bases so that these multinationals, especially those providing internet advertising and digital intermediation services, pay their ‘fair’ share of tax. The failure to reach an agreed outcome among Organisation for Economic Co-operation and Development and Group of Twenty members has led to an increasing number of states to take unilateral measures. In doing so, states need to navigate their obligations under double taxation agreements and trade agreements. An examination of typical double taxation agreements, the General Agreement on Trade in Services, and recent preferential trade agreements shows that states have limited options to expand their tax bases in compliance with their international obligations. Here, the imposition of an appropriately designed digital services tax has political and legal advantages. The growing volume of cross-border digital services and data flows suggests that greater engagement between the international tax and trade regimes is likely in the future, including in the negotiations of disciplines on electronic commerce.
Field Evaluation of a Spatial Repellent Emanation Vest for Personal Protection Against Outdoor Biting Mosquitoes
Authors: Sukkanon Chutipong , Tisgratog Rungarun , Muenworn Vithee , Bangs Michael J , Hii Jeffrey , Chareonviriyaphap Theeraphap
Published: October 2020

Exophilic vectors are an important contributor to residual malaria transmission. Wearable spatial repellents (SR) can potentially provide personal protection in early evening hours before people retire indoors. An SR prototype for passive delivery of transfluthrin (TFT) for protecting humans against nocturnal mosquitoes in Kanchanaburi, western Thailand, is evaluated. A plastic polyethylene terephthalate (PET) sheet (676 cm2) treated with 55-mg TFT (TFT-PET), attached to the back of short-sleeve vest worn by human collector, was evaluated under semifield and outdoor conditions. Field-caught, nonblood-fed female Anopheles minimus s.l. were released in a 40 m length, semifield screened enclosure. Two collectors positioned at opposite ends conducted 12-h human-landing collections (HLC). The outdoor experiment was conducted between treatments among four collectors at four equidistant positions who performed HLC. Both trials were conducted for 30 consecutive nights. TFT-PET provided 67% greater protection (P < 0.001) for 12 h compared with unprotected control, a threefold reduction in the attack. In outdoor trials, TFT-PET provided only 16% protection against An. harrisoni Harbach & Manguin (Diptera: Culicidae) compared with unprotected collector (P = 0.0213). The TFT-PET vest reduced nonanophelines landing by 1.4-fold compared with the PET control with a 29% protective efficacy. These findings suggest that TFT-PET had diminished protective efficacy in an open field environment. Nonetheless, the concept of a wearable TFT emanatory device has the potential for protecting against outdoor biting mosquitoes. Further development of portable SR tools is required, active ingredient selection and dose optimization, and more suitable device design and materials for advancing product feasibility.
The Simple Economics of Wholesale Price-Parity Agreements: The Case of the Airline Tickets Distribution Industry*
Authors: Padilla Jorge , Piccolo Salvatore , Watson Nadine
Published: October 2020

This paper clarifies the differences between retail and wholesale price-parity agreements in vertical industries. In contrast to traditional wide and narrow retail price-parity arrangements, the competitive effects of wholesale price-parity depend on the complexity of the vertical supply chain, the business model operated by sellers and distributors, and the strength of competition between direct and indirect distribution channels. While retail price-parity agreements are almost always anticompetitive, wholesale price-parity agreements may positively affect consumer welfare when direct and indirect distribution channels are close substitutes. To demonstrate the relevance of our analysis for competition policy, we illustrate our findings by referring to an industry that has recently attracted policy and regulatory interest on both sides of the Atlantic: the airline ticket distribution industry. We find that, in this industry, while wholesale price-parity agreements always harm airlines, Global Distribution Systems (GDSs) have preferences more aligned with consumers: when consumers benefit from these provisions, GDSs benefit too.

JEL: K21, L13, L40
In Utero Severe Acute Respiratory Syndrome Coronavirus 2 Infection
Authors: Von Kohorn Isabelle , Stein Sydney R , Shikani Beatrix T , Ramos-Benitez Marcos J , Vannella Kevin M , Hewitt Stephen M , Kleiner David E , Alejo Julie C , Burbelo Peter , Cohen Jeffrey I , Wiedermann Bernhard L , Chertow Daniel S
Published: October 2020

Evidence for in utero transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is growing but not definitive. We present a case of neonatal infection that supports in utero transmission of SARS-CoV-2 and provides insight into the hematogenous spread from mother to fetus.
Extracellular vesicles released from irradiated neonatal mouse cheek tissue increased cell survival after radiation
Authors: Ariyoshi Kentaro , Hiroyama Yota , Fujiwara Naoya , Miura Tomisato , Kasai Kosuke , Nakata Akifumi , Fujishima Yohei , Ting Goh Valerie Swee , Yoshida Mitsuaki A
Published: October 2020

Alopecia is one of the common symptoms after high-dose radiation exposure. In our experiments, neonatal mice that received 7 Gy X-ray exhibited defects in overall hair growth, except for their cheeks. This phenomenon might suggest that some substances were secreted and prevented hair follicle loss in the infant tissues around their cheeks after radiation damage. In this study, we focused on exosome-like vesicles (ELV) secreted from cheek skin tissues and back skin tissues, as control, and examined their radiation protective effects on mouse fibroblast cell lines. We observed that ELV from irradiated cheek skin showed protective effects from radiation. Our results suggest that ELV from radiation-exposed cheek skin tissue is one of the secreted factors that prevent hair follicle loss after high-dose radiation.
HIGH-TILLERING AND DWARF 12 modulates photosynthesis and plant architecture by affecting carotenoid biosynthesis in rice
Authors: Zhou Hui , Yang Mai , Zhao Lei , Zhu Zuofeng , Liu Fengxia , Sun Hongying , Sun Chuanqing , Tan Lubin
Published: October 2020

Photosynthesis and plant architecture are important factors influencing grain yield in rice (Oryza sativa L.). Here, we identified a high-tillering and dwarf 12 (htd12) mutant and analyzed the effects of the HTD12 mutation on these important factors. HTD12 encodes a 15-cis-ζ-carotene isomerase (Z-ISO) belonging to the nitrite and nitric oxide reductase U (NnrU) protein family, as revealed by positional mapping and transformation experiments. Sequence analysis showed that a single nucleotide transition from guanine (G) to adenine (A) in the 3’ acceptor site between the first intron and second exon of HTD12 alters its mRNA splicing in htd12 plants, resulting in a 49-amino acid deletion that affects carotenoid biosynthesis and photosynthesis. In addition, compared with the wild type, htd12 had significantly lower concentrations of ent-2’-epi-5-deoxystrigol (epi-5DS), a native strigolactone, in both roots and root exudates, resulting in an obvious increase in tiller number and decrease in plant height. These findings indicate that HTD12, the rice homolog of Z-ISO, regulates chloroplast development and photosynthesis by functioning in carotenoid biosynthesis, and modulates plant architecture by affecting strigolactone concentrations.
A network-based comparative framework to study conservation and divergence of proteomes in plant phylogenies
Authors: Shin Junha , Marx Harald , Richards Alicia , Vaneechoutte Dries , Jayaraman Dhileepkumar , Maeda Junko , Chakraborty Sanhita , Sussman Michael , Vandepoele Klaas , Ané Jean-Michel , Coon Joshua , Roy Sushmita
Published: October 2020

Comparative functional genomics offers a powerful approach to study species evolution. To date, the majority of these studies have focused on the transcriptome in mammalian and yeast phylogenies. Here, we present a novel multi-species proteomic dataset and a computational pipeline to systematically compare the protein levels across multiple plant species. Globally we find that protein levels diverge according to phylogenetic distance but is more constrained than the mRNA level. Module-level comparative analysis of groups of proteins shows that proteins that are more highly expressed tend to be more conserved. To interpret the evolutionary patterns of conservation and divergence, we develop a novel network-based integrative analysis pipeline that combines publicly available transcriptomic datasets to define co-expression modules. Our analysis pipeline can be used to relate the changes in protein levels to different species-specific phenotypic traits. We present a case study with the rhizobia-legume symbiosis process that supports the role of autophagy in this symbiotic association.
Abundance of primordial black holes in peak theory for an arbitrary power spectrum
Authors: Yoo Chul-Moon , Harada Tomohiro , Hirano Shin’ichi , Kohri Kazunori
Published: October 2020

We modify the procedure for estimating the primordial black hole (PBH) abundance proposed in [C.-M. Yoo, T. Harada, J. Garriga, and K. Kohri, Prog. Theor. Exp. Phys. 2018, 123E01 (2018)] so that it can be applied to a broad power spectrum such as the scale-invariant flat power spectrum. In the new procedure we focus on peaks of the Laplacian of the curvature perturbation $\Delta \zeta$, and use the values of $\Delta \zeta$ and $\Delta \Delta \zeta $ at each peak to specify the profile of $\zeta$ as a function of the radial coordinate; the values of $\zeta$ and $\Delta \zeta$ are used in the previous paper. The new procedure decouples the larger-scale environmental effect from the estimate of PBH abundance. Because the redundant variance due to the environmental effect is eliminated, we obtain a narrower shape of the mass spectrum compared to the previous procedure. Furthermore, the new procedure allows us to estimate the PBH abundance for the scale-invariant flat power spectrum by introducing a window function. Although the final result depends on the choice of the window function, we show that the $k$-space tophat window minimizes the extra reduction of the mass spectrum due to the window function. That is, the $k$-space tophat window has the minimum required property in the theoretical PBH estimation. Our procedure makes it possible to calculate the PBH mass spectrum for an arbitrary power spectrum by using a plausible PBH formation criterion with the nonlinear relation taken into account.
Infinite-Parameter ADHM Transform
Authors: Ward R. S.
Published: October 2020

The Atiyah–Drinfeld–Hitchin–Manin transform and its various generalizations are examples of nonlinear integral transforms between finite-dimensional moduli spaces. This note describes a natural infinite-dimensional generalization, where the transform becomes a map from boundary data to a family of solutions of the self-duality equations in a domain.
The Alternating Block Decomposition of Iterated Integrals and Cyclic Insertion on Multiple Zeta Values
Authors: Charlton Steven
Published: October 2020

The cyclic insertion conjecture of Borwein, Bradley, Broadhurst and Lisoněk states that by inserting all cyclic permutations of some initial blocks of 2’s into the multiple zeta value ζ(1, 3, … , 1, 3) and summing, one obtains an explicit rational multiple of a power of π. Hoffman gives a conjectural identity of a similar flavour concerning $ 2 \zeta(3,3,\{2\}^m) - \zeta(3,\{2\}^m,1,2) $.

In this paper, we introduce the ‘generalized cyclic insertion conjecture’, which we describe using a new combinatorial structure on iterated integrals—the so-called alternating block decomposition. We see that both the original BBBL cyclic insertion conjecture, and the Hoffman’s conjectural identity, are special cases of this generalized cyclic insertion conjecture. By using Brown’s motivic MZV framework, we establish that some symmetrized version of the generalized cyclic insertion conjecture always holds, up to a rational; this provides some evidence for the generalized conjecture.
Clinico-epidemiologic characteristics of the 2019 dengue outbreak in Bangladesh
Authors: Hasan Mohammad Jahid , Tabassum Tamanna , Sharif Mohiuddin , Khan Mohammad Abdullah Saeed , Bipasha Akhi Roy , Basher Ariful , Islam Mohammad Rafiqul , Amin Mohammad Robed , Gozal David
Published: October 2020

Background

Dengue fever shows a broad range of clinical presentations worldwide. Here we report on our clinical findings during the 2019 dengue outbreak in one of the largest tertiary care hospitals in Dhaka, the capital of Bangladesh.

Methods

A total of 747 suspected dengue cases (553 confirmed and 194 probable) were interviewed with a pro forma case record form. Statistical analyses were conducted using SPSS 20.0. Ethical clearance was obtained from the Dhaka Medical College.

Results

The mean age of the dengue cases was 27 y and approximately two-thirds were male. Positive tests for NS1 and anti-dengue immunoglobulin M antibody were present in 91.9% and 59.4% of the cases, respectively. Thrombocytopenia was present in 69% of cases and fever was present in 99.1% of cases. Gastrointestinal (GI) features, including anorexia and/or vomiting (69.4%), abdominal pain (39.8%) and diarrhoea (25.6%), were more prevalent than typical rash and pain symptoms. Hypotension was present in approximately one-quarter of patients (25.4%). Probable and confirmed dengue cases have shown similar clinical characteristics and laboratory findings.

Conclusions

The 2019 outbreak of dengue fever in Bangladesh was characterized by increased presentation with GI features. Recognition of this trend would permit early diagnosis and proper management of patients.
The Political Economy of the Related Party Transactions Regulation in the Shareholders’ Rights Directive II
Authors: Gözlügöl Alperen Afşin
Published: October 2020

This study tracks the legislative process of the Shareholders’ Rights Directive II as regards the regulation of related party transactions (RPT) and identifies important factors that have led to the current regime of RPT regulation in the EU. While the European Commission’s Proposal subjected material RPTs to approval by the majority of (minority) shareholders (MOM approval) and a number of other requirements, the requirements have been greatly watered down in the legislative process. The analysis suggests that the ambition of the European policy makers to strengthen European capital markets and attract/facilitate more foreign/cross-border investment led the European Commission to propose MOM approval for RPTs based on the feedback/demand from the institutional investors. This proposal, however, faced a backlash from the business community and some Member States. Relatedly, as a result of the pressure of the interest groups that represent the European companies and some reluctant Member States, during the legislative process, numerous compromises have been made, giving wide discretion to Member States in devising a regime of RPT regulation and effectively spelling the death of the European Commission’s ambitions. The study then concludes by connecting this process to accounts of how corporate law develops in the literature.
Evaluation of Resident Physicians’ Knowledge of and Attitudes Towards Prescribing Buprenorphine for Patients With Opioid Use Disorder
Authors: Shuey Bryant , Lee Dasom , Ugalde Israel , Borgan Saif , Bresnan Caroline , Qureshi Marvi , Mhaskar Rahul , Oxner Asa
Published: October 2020

Objective:

To determine internal medicine (IM) residents’ knowledge of, attitudes towards, and barriers to prescribing buprenorphine for opioid use disorder (OUD).

Methods:

We conducted a cross-sectional study of IM residents across all 35 Accreditation Council for Graduate Medical Education (ACGME) accredited Florida IM residency programs. We used an online survey to collect information about resident demographics, substance use curriculums, career interests, content knowledge about diagnosing and managing OUD, and attitudes about and barriers to prescribing buprenorphine for OUD. We used Chi-square test to explore differences in interest in prescribing buprenorphine. We created a composite knowledge score and investigated distribution of knowledge among characteristics via Mann-Whitney U test.

Results:

There were 161 participants (response rate 16.0%, n = 1008) across 35 programs Seventy-seven percent of residents provided care for patients with OUD more than once per month. Seventy-four percent report no buprenorphine prescribing training. Higher knowledge scores, interest in primary care, being an intern, and caring for patients with OUD more than monthly were associated with interest in obtaining a buprenorphine waiver (P < 0.05). Limited knowledge about OUD was the most important barrier to prescribing buprenorphine. Eighty-nine percent support legislation to deregulate buprenorphine.

Conclusions:

Knowledge about managing OUD was poor and represented the most commonly cited barrier to prescribing buprenorphine. Residents want to expand their role in treating OUD. Our findings warrant incorporating addiction medicine into residency curriculum standards. Legislation removing the buprenorphine waiver requirement may increase the number of resident buprenorphine prescribers and improve treatment options for patients with opioid addiction.
Femoral Neck Hounsfield Units as an Adjunct for Bone Mineral Density After Combat-Related Lower Extremity Amputation
Authors: Hoyt Benjamin W. , Lundy Alex E. , Clark DesRaj M. , Colantonio Donald , Tintle Scott M. , Potter Benjamin K.
Published: October 2020

Objectives:

To correlate femoral neck Hounsfield units (HUs) measured on a computed tomography (CT) scan to dual-energy x-ray absorptiometry (DEXA) T-scores allowing evaluation of bone mineral density (BMD) over time after lower extremity trauma–related amputation.

Design:

Retrospective cohort study.

Setting:

United States military trauma referral center.

Patients:

Military combat-related lower extremity amputees with both DEXA and CT scans within 6 months of each other.

Intervention:

None.

Main Outcome Measures:

Correlation between femoral neck comprehensive mean HUs and BMD and HUs threshold for low BMD.

Results:

Regression model correlation (r) between CT HU and DEXA T-score was r = 0.84 [95% confidence interval (CI) 0.52–0.94] and r = 0.81 (95% CI 0.57–0.92) when CT imaging was separated from DEXA by less than 4 and 5 months, respectively. Beyond 5 months separation, correlation decreased to r = 0.60 (95% CI 0.29–0.80). Using a receiver operator characteristic curve for mean comprehensive HUs to determine low BMD with 4-month cut-off, a threshold of 151 HUs was 97% sensitive and 84% specific to identify low BMD, whereas 98 HUs was 100% sensitive and 100% specific to identify osteoporosis.

Conclusion:

Using opportunistic CT, clinicians can reliably estimate BMD in trauma-related amputees. This information will inform providers making decisions regarding weightbearing and bisphosphonate therapy to limit further loss. Future phases of this study will aim to use this correlation to study the effects of weightbearing advancement timing, bisphosphonate therapy, and interventions on the natural history of bone density after amputation.

Level of Evidence:

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Variation in Treatment Approaches to Adolescent Midshaft Clavicle Fractures in Pediatric Versus Adult Hospitals
Authors: Zhang Dafang , Heyworth Benton E. , Liotta Elizabeth S. , Hergott Katelyn A. , Earp Brandon E.
Published: October 2020

Objective:

The primary objective of this study was to identify differences in the treatment approach for isolated, displaced midshaft clavicle fractures in adolescent patients 15–18 years of age at adult versus pediatric hospitals. The secondary objective of this study was to identify factors associated with the surgical treatment of these fractures in this age group.

Design:

Retrospective cohort study.

Setting:

Two adult and one pediatric tertiary care referral hospitals.

Patients/Participants:

Adolescent patients 15–18 years of age with isolated, displaced midshaft clavicle fractures treated at 2 adult tertiary care referral hospitals and one pediatric tertiary care referral hospital were identified. A total of 214 patients, 105 from the adult hospitals and 109 from the pediatric hospital, were included.

Intervention:

Nonoperative versus surgical treatment of clavicle fractures.

Main Outcome Measurement:

Surgical treatment.

Results:

A multivariable logistic regression analysis showed that superior–inferior fracture displacement [odds ratio (OR) 1.13, 95% confidence interval (CI) 1.06–1.20], dominant upper extremity injury (OR 2.60, 95% CI 1.19–5.67), and treatment at an adult hospital (OR 5.28, 95% CI 2.28–12.2) were independently associated with the surgical treatment of adolescent displaced midshaft clavicle fractures.

Conclusions:

After controlling for relevant demographic and fracture characteristics, adolescent patients treated at adult hospitals for displaced midshaft clavicle fractures have more than 5 times the odds of surgical treatment than those treated at a pediatric hospital. Significant practice variation across institutions reflects ongoing controversy in surgical indications and underscores the need for high-quality prospective outcome studies.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.