bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini-Channel Liquid Cooling System for Improving Heat Transfer Capacity and Thermal Uniformity in Battery Packs for Electric Vehicles
Authors: Li Congbo , Li Yongsheng , Srinivaas Sanjay , Zhang Jinwen , Qu Shiyang , Li Wei
Published: April 2021

Temperature is a significant factor affecting performance and safety of energy storage systems such as battery packs. How to design a reliable battery thermal management system (BTMS) is still a hot issue at present. Most of the past researches have focused on methods of reducing temperature rise. This paper mainly studies how to reduce the temperature deviation of the battery pack while ensuring heat dissipation conditions. This paper designs a mini-channel liquid cooling BTMS with a side cover to improve heat transfer capacity and thermal uniformity in battery packs. By analyzing different side cover materials, cooling water temperature, and water channel structure, the influence of different parameters on battery heat dissipation and uniformity is obtained. The main findings are: (1) the presence of the side cover can effectively reduce the maximum temperature and temperature deviation, and the material with high thermal conductivity is more likely to dissipate heat, (2) The increase of cooling water inlet temperature can improve temperature uniformity, and (3) When the cross-sectional area is fixed, as the channel depth increases, the temperature deviation gradually decreases.
The Development of a Highly Durable Fe-N-C Electrocatalyst With Favorable Carbon Nanotube Structures for the Oxygen Reduction in PEMFCs
Authors: Shen Shuiyun , Ren Ziwen , Xiang Silei , Chen Shiqu , Tan Zehao , Li Huiyuan , Zhang Junliang
Published: April 2021

Proton exchange membrane fuel cell (PEMFC) is a crucial route for energy saving, emission reduction, and the development of new energy vehicles because of its high power density, high energy density, as well as the low operating temperature which corresponds to fast starting and power matching. However, the rare and expensive Pt resource greatly hinders the mass production of the fuel cell, and the development of highly active and durable non-precious metal catalysts toward the oxygen reduction reaction (ORR) in the cathode is considered to be the ultimate solution. In this article, a highly active and durable Fe-N-C catalyst was facilely derived from metal-organic framework (MOF) materials, and a favorable structure of carbon nanotubes (CNTs) was formed, which accounts for a desired good durability. The as-optimized catalyst has a half-wave potential of 0.84 V for the ORR, which is comparable to that of commercial Pt/C. More attractively, it has good stabilities both in rotating disk electrode (RDE) and single-cell tests, which provides a large practical application potential in the replacement of Pt catalyst as the ORR electrocatalyst in fuel cells.
Effect of ZrO2 Nanoparticles and Mechanical Milling on Microstructure and Mechanical Properties of Al–ZrO2 Nanocomposites
Authors: Aktaş Sinem , Anıl Diler Ege
Published: April 2021

Nano-aluminum powders and nano-ZrO2 reinforcement particles were mechanically milled and hot-pressed to produce Al–ZrO2 nanocomposites. Microstructure and mechanical properties of Al–ZrO2 nanocomposites were investigated using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses and by performing hardness and compression testing. Uniform particle distribution was obtained up to 3 wt% of nano-ZrO2 particles using nano-sized aluminum powders as matrix powders and by applying a mechanical milling process. As the nano-ZrO2 reinforcement particles were uniformly distributed in the matrix, the relative density of the Al–ZrO2 nanocomposites increased up to 3 wt% nano-ZrO2 particles with an increase in milling time; on the other hand, the relative density decreased and the porosity increased with high-weight fractions (>3 wt%) of nano-ZrO2 particles due to the negative combined effect of less densification and an increase in the number of particle clusters. The hardness and compressive strength of the Al–ZrO2 nanocomposites improved despite increased porosity. However, the compressive strength of Al–ZrO2 nanocomposites with a high amount (>3 wt%) of nano-ZrO2 particles began to decrease due to the negative combined effect of the less densification of the powder particles and the clustering of nano-ZrO2 reinforcement particles. The brittle-ductile fracture occurred in the Al–ZrO2 nanocomposites.
Experimental Investigation of Direct Steam Generation Dynamics in Solar Fresnel Collectors
Authors: Mokhtar Marwan , Zahler Christian , Stieglitz Robert
Published: April 2021

Direct steam generation (DSG) is a technology used to produce steam from a solar concentrated thermal plant directly in the solar field without the use of an intermediate steam generator. This technology is attractive due to economic considerations but is technically challenging. In this brief, the results of an experimental study of DSG dynamics are presented. The study provides a detailed description of these effects supported by experimental results and suggests ways to coping with them.
Three-Dimensional Elastoplastic Contact Analysis of Rough Surface Considering a Micro-Scale Effect
Authors: You Shengyu , Tang Jinyuan , Wen Yuqin
Published: April 2021

The micro-surface asperity scale of grinding metal parts is within several microns. When two grinding surfaces are in contact, the unevenness of the plastic deformation of the asperities at the micro-scale leads to greater plastic hardening strength of the material. The results of the nano-indentation experiment conducted in this paper confirmed this phenomenon. Based on conventional mechanism-based strain gradient (CMSG) plasticity theory, the micro-scale plastic constitutive equation of materials is given and then is verified by the nano-indentation experiment. Finite element software abaqus and the user-defined element (UEL) subroutine are used to build three-dimensional rough surface elastoplastic contact models. By calculating the grinding rough surface contact in the macro-scale constitutive model based on J2 theory and in the CMSG plasticity constitutive model, the influence law of plastic micro-scale effect on contact performance is obtained.
Design of Contact-Aided Compliant Flexure Hinge Mechanism Using Superelastic Nitinol
Authors: Ping Zhongyuan , Zhang Tianci , Zhang Chi , Liu Jianbin , Zuo Siyang
Published: April 2021

This paper presents a novel miniature contact-aided compliant mechanism (CCM) that includes flexure hinges and contact-aided structures. This continuum mechanism comprises a nickel–titanium alloy (Nitinol) tube with CCM cut via laser micromachining and actuated using wires bending from −80 deg to +80 deg in four directions. The proposed CCM has the following merits: perfect capacity for deflection around the centroid, a self-backbone, and improved torsional as well as tensile strengths. Further, it is pre-assembled. First, kinematic and static models are used to predict the bending behavior of the mechanism. Thereafter, the maximum strain is evaluated using finite element analysis (FEA) then compared with the static models. Finally, the performances of the mechanism are characterized by experiments. The results validate the proposed models and demonstrate that the torsional and tensile strengths of the proposed CCM increased by more than 100% and 30%, respectively, compared with those of conventional non-CCMs with a similar fatigue life. Moreover, with the integrated forceps and probe, the proposed mechanism can achieve object transfer and square trajectory scanning of the targeted location. These experimental results demonstrate the potential clinical value of the proposed mechanism and provide important insights into the design of long and flexible instruments for endoscopic surgery.
Heterovalent semiconductor structures and devices grown by molecular beam epitaxy
Authors: Zhang Yong-Hang , Smith David J.
Published: April 2021

Heterovalent structures consisting of group II-VI/group III-V compound semiconductors offer attractive properties, such as a very broad range of bandgaps, large conduction band offsets, high electron and hole mobilities, and quantum-material properties such as electric-field-induced topological insulator states. These properties and characteristics are highly desirable for many electronic and optoelectronic devices as well as potential condensed-matter quantum-physics applications. Here, we provide an overview of our recent studies of the MBE growth and characterization of zincblende II-VI/III-V heterostructures as well as several novel device applications based on different sets of these materials. By combining materials with small lattice mismatch, such as ZnTe/GaSb (Δa/a ∼ 0.13%), CdTe/InSb (Δa/a ∼ 0.05%), and ZnSe/GaAs (Δa/a ∼ 0.26%), epitaxial films of excellent crystallinity were grown once the growth conditions had been optimized. Cross-sectional observations using conventional and atomic-resolution electron microscopy revealed coherent interfaces and close to defect-free heterostructures. Measurements across CdTe/InSb interfaces indicated a limited amount (∼1.5 nm) of chemical intermixing. Results for ZnTe/GaSb distributed Bragg reflectors, CdTe/MgxCd1−xTe double heterostructures, and CdTe/InSb two-color photodetectors are briefly presented, and the growth of a rock salt/zincblende PbTe/CdTe/InSb heterostructure is also described.
Courses bring field sites and labs to the small screen
Authors: Pennisi Elizabeth
Published: April 2021

Some pandemic-induced changes to hands-on classes may be here to stay.
Giant piezoelectricity in oxide thin films with nanopillar structure
Authors: Liu Huajun , Wu Haijun , Ong Khuong Phuong , Yang Tiannan , Yang Ping , Das Pranab Kumar , Chi Xiao , Zhang Yang , Diao Caozheng , Wong Wai Kong Alaric , Chew Eh Piew , Chen Yi Fan , Tan Chee Kiang Ivan , Rusydi Andrivo , Breese Mark B. H. , Singh David J. , Chen Long-Qing , Pennycook Stephen J. , Yao Kui
Published: April 2021

Simple strain enhancement

Piezoelectric materials are important as sensors and transducers for applications such as ultrasonics. Liu
et al.
discovered nanopillar regions in a sodium-niobium-oxide film that substantially improve the piezoelectric properties (see the Perspective by Bassiri-Gharb). These nanopillar regions reverse where the cations and anions are located in the crystal structure, with a distinctive boundary in between. This difference in structure results in a strain-sensitive polarity that enhances the piezoelectric properties in a chemically simple material.

Science
this issue p.
292
; see also p.
252
The burgeoning reach of animal culture
Authors: Whiten Andrew
Published: April 2021

We are not alone

Before the mid-20th century, it was generally assumed that culture, behavior learned from others, was specific to humans. However, starting with identification in a few species, evidence that animals can learn and transmit behaviors has accumulated at an ever-increasing pace. Today, there is no doubt that culture is widespread among animal species, both vertebrates and invertebrates, marine and terrestrial. Whiten reviews evidence for animal culture and elaborates on the wide array of forms that such culture takes. Recognizing that other species have complex and varied culture has implications for conservation and welfare and for understanding the evolution of this essential component of animal societies, including our own.

Science
, this issue p.
eabe6514
At-risk marine biodiversity faces extensive, expanding, and intensifying human impacts
Authors: O’Hara Casey C. , Frazier Melanie , Halpern Benjamin S.
Published: April 2021

An ever-growing human footprint

Human activities are increasingly affecting the marine environment but understanding how much and in what ways is an extreme challenge given the vastness of this system. O'Hara
et al.
looked at a suite of human-induced stressors on >1000 marine species over the course of 13 years. They found that species are experiencing increasing levels of stress over more than half of their ranges, with some species having an even higher proportion of their ranges affected. Fishing has the largest impact, but other stressors, such as climate change, are also important and growing.

Science
, this issue p.
84
Isolated boron in zeolite for oxidative dehydrogenation of propane
Authors: Zhou Hang , Yi Xianfeng , Hui Yu , Wang Liang , Chen Wei , Qin Yucai , Wang Ming , Ma Jiabi , Chu Xuefeng , Wang Yeqing , Hong Xin , Chen Zifeng , Meng Xiangju , Wang Hai , Zhu Qiuyan , Song Lijuan , Zheng Anmin , Xiao Feng-Shou
Published: April 2021

Isolating and stabilizing boron

Oxidative dehydrogenation of propane can produce propene from shale gas and help to replace petroleum as a propene feedstock. Boron-based catalysts can have high selectivity to propene, but the water by-product can deactivate the catalyst by hydrolyzing boron. Zhou
et al.
synthesized boron-doped silicate zeolites containing isolated boron sites that were stable against hydrolysis. The catalyst could achieve one-pass propane conversions up to ∼44% with selectivities for propene and >80% for ethene. They observed no deactivation after a 210-hour continuous test.

Science
, this issue p.
76
Diagnosing Pulmonary Tuberculosis by Using Sequence-Specific Purification of Urine Cell-Free DNA
Authors: Oreskovic Amy , Panpradist Nuttada , Marangu Diana , Ngwane M. William , Magcaba Zanele P. , Ngcobo Sindiswa , Ngcobo Zinhle , Horne David J. , Wilson Douglas P. K. , Shapiro Adrienne E. , Drain Paul K. , Lutz Barry R.
Published: April 2021

Transrenal urine cell-free DNA (cfDNA) is a promising tuberculosis (TB) biomarker, but is challenging to detect because of the short length (<100 bp) and low concentration of TB-specific fragments. We aimed to improve the diagnostic sensitivity of TB urine cfDNA by increasing recovery of short fragments during sample preparation.
Regulation of Hepatitis B Virus Replication by Cyclin Docking Motifs in Core Protein
Authors: Liu Haitao , Xi Ji , Hu Jianming
Published: April 2021

Hepatitis B virus (HBV) is an important global human pathogen and persistently infects hundreds of millions of people, who are at high risk of cirrhosis and liver cancer. HBV capsid packages a host cell protein kinase, the cyclin-dependent kinase 2 (CDK2), which is thought to be required to trigger disassembly of the viral nucleocapsid during infection by phosphorylating the capsid protein, a prerequisite for successful infection.
Activation of STING Signaling Pathway Effectively Blocks Human Coronavirus Infection
Authors: Liu Wei , Reyes Hanako M. , Yang June F. , Li Yize , Stewart Kathleen M. , Basil Maria C. , Lin Susan M. , Katzen Jeremy , Morrisey Edward E. , Weiss Susan R. , You Jianxin
Published: April 2021

The highly infectious and lethal SARS-CoV-2 is posing an unprecedented threat to public health. Other coronaviruses are likely to jump from a nonhuman animal to humans in the future.
Supplemental Material: Isotopic spatial-temporal evolution of magmatic rocks in the Gangdese belt: Implications for the origin of Miocene post-collisional giant porphyry deposits in southern Tibet
Authors: Luo Chen-Hao , Wang Rui , al. et
Published: April 2021

Two supplemental pictures and five supplemental tables. The pictures exhibit the Nd-Hf isotopic spatial distribution of the Gangdese belt magmatic rocks, southern Tibet, by using the average isotopic values of per 0.5 longitude (Fig. S1) and two additional magma mixing models related to the Jurassic and Cretaceous Gangdese belt magmatic rocks, southern Tibet (Fig. S2). The talbes contain all the data used in this research and their references.
Supplemental Material: Early and middle Miocene ice sheet dynamics in the Ross Sea: Results from integrated core-log-seismic interpretation
Authors: Pérez L F , al. et
Published: April 2021

Additional information regarding methods (Reflection seismic processing, Drill-site measurements, Core-log-seismic correlations, Spatial Velocity calculations, and Reflection Tomography model) and regional stratigraphy descriptions, as well as detailed considerations regarding the opal distribution and depth.
Supplemental Material: New insights into the formation and emplacement of impact melt rocks within the Chicxulub impact structure, following the 2016 IODP-ICDP Expedition 364
Authors: Graaff Sietze J. de , al. et
Published: April 2021

Appendix S1, containing all geochemical data and specific core depths of all samples and geochemical results for geologic reference materials presented in the article. Figures S1–S3, containing thinsection photographs of representative pre-impact lithologies.
Supplemental Material: Oxygen isotope (d18O) trends measured from Ordovician conodont apatite using secondary ion mass spectrometry (SIMS): Implications for paleo-thermometry studies
Authors: Edwards Cole T , al. et
Published: April 2021

Table S1: Stable oxygen isotopic data of each conodont measured using SIMS; Table S2: Stable oxygen isotopic data using SIMS of the Durango apatite standard and a modern shark tooth; Figure S1: Cross plot of d18Omean values and OH/16O from the Shingle Pass (blue), Antelope Range (green), and Cincinnati Arch (white) sections.
Low-energy sweeteners and body weight: a citation network analysis
Authors: Normand Mie , Ritz Christian , Mela David , Raben Anne
Published: April 2021

Objective

Reviews on the relationship of low-energy sweeteners (LES) with body weight (BW) have reached widely differing conclusions. To assess possible citation bias, citation analysis was used to quantify the relevant characteristics of cited articles, and explore citation patterns in relation to review conclusions.

Design

A systematic search identified reviews published from January 2010 to March 2020. Different characteristics (for example, type of review or research, journal impact factor, conclusions) were extracted from the reviews and cited articles. Logistic regression was used to estimate likelihood of articles with particular characteristics being cited in reviews. A qualitative network analysis linked reviews sub-grouped by conclusions with the types of articles they cited.

Main outcome measures

(OR; 95% CI) for likelihood that articles with particular characteristics were cited as evidence in reviews.

Results

From 33 reviews identified, 183 different articles were cited (including other reviews). Narrative reviews were 62% less likely to be cited than systematic reviews with meta-analysis (OR 0.38; 0.16 to 0.86; p=0.03). Likelihood of being cited was higher for evidence on children than adults (OR 2.27; 1.59 to 3.25; p<0.0001), and with increased journal impact factor (OR 1.15; 1.00 to 1.31; p=0.04). No other factors were statistically significant in the main analysis, and few factors were significant in subgroup analyses. Network analysis showed that reviews concluding a beneficial relationship of LES with BW cited mainly randomised controlled trials, whereas reviews concluding an adverse relationship cited mainly observational studies.

Conclusions

Overall reference to the available evidence across reviews appears largely arbitrary, making citation bias likely. Differences in the conclusions of individual reviews map onto different types of evidence cited. Overall, inconsistent and selective use of the available evidence may account for the diversity of conclusions in reviews on LES and BW.

Trial registration number

Prior to data analysis, the protocol was registered with the Open Science Framework (https://osf.io/9ghws).
SARS-CoV-2 population-based seroprevalence studies in Europe: a scoping review
Authors: Grant Rebecca , Dub Timothée , Andrianou Xanthi , Nohynek Hanna , Wilder-Smith Annelies , Pezzotti Patrizio , Fontanet Arnaud
Published: April 2021

Objectives

We aimed to review SARS-CoV-2 seroprevalence studies conducted in Europe to understand how they may be used to inform ongoing control strategies for COVID-19.

Design

Scoping review of peer-reviewed publications and manuscripts on preprint servers from January 2020 to 15 September 2020.

Primary measure

Seroprevalence estimate (and lower and upper CIs). For studies conducted across a country or territory, we used the seroprevalence estimate and the upper and lower CIs and compared them to the total number of reported infections to calculate the ratio of reported to expected infections.

Results

We identified 23 population-based seroprevalence studies conducted in Europe. Among 12 general population studies, seroprevalence ranged from 0.42% among residual clinical samples in Greece to 13.6% in an area of high transmission in Gangelt, Germany. Of the eight studies in blood donors, seroprevalence ranged from 0.91% in North-Western Germany to 23.3% in a high-transmission area in Lombardy region, Italy. In three studies which recruited individuals through employment, seroprevalence ranged from 0.5% among factory workers in Frankfurt, Germany, to 10.2% among university employees in Milan, Italy. In comparison to nationally reported cases, the extent of infection, as derived from these seroprevalence estimates, is manyfold higher and largely heterogeneous.

Conclusion

Exposure to the virus in Europe has not reached a level of infection that would prevent further circulation of the virus. Effective vaccine candidates are urgently required to deliver the level of immunity in the population.
Psychological and occupational impact of the COVID-19 pandemic on UK surgeons: a qualitative investigation
Authors: Al-Ghunaim Tmam Abdulaziz , Johnson Judith , Biyani Chandra Shekhar , O’Connor Daryl
Published: April 2021

Background

The COVID-19 pandemic represents the greatest biopsychosocial emergency the world has faced for a century. The pandemic has changed how individuals live and work, and in particular, frontline healthcare professionals have been exposed to alarming levels of stress.

Objective

The aim of this study was to understand the professional and personal effects of COVID-19 pandemic on surgeons working in the UK National Health Service (NHS).

Setting

Surgical departments in the NHS.

Design

Between May and July 2020, as part of an ongoing study, we asked surgeons two open-ended questions: ‘What challenges are the COVID-19 crisis currently presenting to you in your work and home life?’ and ‘How is this stress affecting you personally?’ Thematic analysis was used for the qualitative data. Responses to the second question were also categorised into four groups reflecting valence: positive, neutral, mildly negative and strongly negative.

Results

A total of 141 surgeons responded to the survey and the results indicated that 85.8% reported that they were generally negatively affected by the COVID-19 pandemic, of which 7.8% were strongly affected in a negative way. Qualitative thematic analysis identified four key themes from responses relating to the impact of the pandemic: (1) changing and challenging work environment as a result of COVID-19; (2) challenges to professional life and development; (3) management of change and loss in the respondents’ personal lives; (4) emotional and psychological impacts.

Conclusion

The results highlighted the substantial emotional and psychological effects of the COVID-19 pandemic on surgeons’ mental health, particularly in relation to fear and anxiety, loss of motivation, low mood, stress and burnout. There is an urgent need for workplace support and mental health interventions to help surgeons cope with the difficulties they face during the ongoing COVID-19 pandemic.
Sexual intercourse before exercise has a detrimental effect on lower extremity muscle strength in men
Authors: Kirecci Sinan Levent , Albayrak Ahmet Tevfik , Yavuzsan Abdullah Hizir , Yesildal Cumhur , Ilgi Musab , Kutsal Cemil
Published: April 2021

Introduction

The question of whether sexual intercourse can harm athletic performance is a long-debated topic since first sport competitions were invented. Therefore, due to the lack of solid evidence, we aimed to evaluate the effects of sexual intercourse on muscle training performance.

Materials and methods

Physically and sexually active, 50 men (age=29.3±1.14 years) were enrolled in the study. Participants completed three weight training sessions and all sessions were at the same time of the day. The maximum weight was adjusted in the first session. In the second and third sessions, they performed five repetitions of the squat with their maximum weight for each set with a total of five sets after participating in and abstaining from sexual intercourse the night before, respectively. The duration of sexual intercourse was measured with a stopwatch.

Results

The mean duration of sex was measured to be 13.8±3.61 min. Furthermore, the mean lifted weight before sex was calculated to be 109.4±11.41 kg and the mean lifted weight after sex was calculated to be 107±11.05 kg. According to obtained data, sexual intercourse has a significant detrimental effect on maximum weight in squat training (p=0001).

Conclusion

Results demonstrate that sexual intercourse within 24 hours before exercise have detrimental effect on lower extremity muscle force, which suggests that restricting sexual activity before a short-term activity may be necessary.
Immediate consequences and solutions used to maintain medical education during the COVID-19 pandemic for residents and medical students: a restricted review
Authors: Chasset François , Barral Matthias , Steichen Olivier , Legrand Anne
Published: April 2021

Background

The COVID-19 outbreak has dramatically impacted medical education, both bedside and academic teaching had to be adapted to comply with the reorganisation of care and social distancing measures.

Objectives

To overview the impact of the pandemic on medical education, including the pedagogical responses adopted and their assessment by medical students and residents.

Material and methods

This restricted systematic review was performed using Rayyan QCRI, to select observational or interventional articles and field experience reports assessing the impact of the COVID-19 pandemic on medical education for medical students and residents. Study design, study population, geographical origin, use of an educational tools (including softwares and social media), their type and assessment, were recorded. For studies evaluating a specific tool the Medical Education Research Study Quality Instrument (MERSQI) was used to assess study quality.

Results

The literature search identified 1480 references and 60 articles were selected. Most articles focused on residents (41/60; 69%), and half (30/60; 50%) involved surgical specialties. Online courses were the most frequently used pedagogical tool (52/60; 88%). Simulation tools were used more frequently in articles involving surgical specialties (15/29; 52%) compared with medical specialties (2/14; 12%) (p=0.01). Only four studies reported the assessment of pedagogical tools by medical students, their MERSQI scores ranged from 5.5/18 to 9.0/18.

Conclusion

Medical education was highly impacted by the COVID-19 pandemic particularly in surgical specialties. Online courses were the most frequently attempted solution to cope with social distancing constraints. Medical students' assessment of pedagogical tools was mostly positive, but the methodological quality of those studies was limited.
Was physics ever deterministic? The historical basis of determinism and the image of classical physics
Authors: van Strien Marij
Published: April 2021

Determinism is generally regarded as one of the main characteristics of classical physics, that is, the physics of the eighteenth and nineteenth century. However, an inquiry into eighteenth and nineteenth century physics shows that the aim of accounting for all phenomena on the basis of deterministic equations of motion remained far out of reach. Famous statements of universal determinism, such as those of Laplace and Du Bois-Reymond, were made within a specific context and research program and did not represent a majority view. I argue that in this period, determinism was often an expectation rather than an established result, and that especially toward the late nineteenth and early twentieth century, it was often thought of as a presupposition of physics: physicists such as Mach, Poincaré and Boltzmann regarded determinism as a feature of scientific research, rather than as a claim about the world. It is only retrospectively that an image was created according to which classical physics was uniformly deterministic.
Statistical odd-even staggering in few fermions systems
Authors: Pennini F. , Plastino A. , Ferri G. L. , Arizmendi M. C.
Published: April 2021

The odd-even staggering (OES) in nuclear binding energies is a well-known fact. A rather similar effect can be found in other finite fermion systems. For instance, ultra small metallic grains and metal clusters. The staggering in nuclei and grains is attributed primarily to pairing correlations. In clusters, it is originated by the Jahn–Teller effect [Phys. Rev. Lett. 81, 3599 (1998)]. Here, we work with a simple, Lipkin-like, exactly solvable two-level fermion model. A statistical mechanics’ treatment of it shows that OES effects also emerge here, as revealed by theoretical tools connected with the so-called statistical complexity.
Stability and Bifurcation in an SI Epidemic Model with Additive Allee Effect and Time Delay
Authors: Lv Yangyang , Chen Lijuan , Chen Fengde , Li Zhong
Published: April 2021

In this paper, we consider an SI epidemic model incorporating additive Allee effect and time delay. The primary purpose of this paper is to study the dynamics of the above system. Firstly, for the model without time delay, we demonstrate the existence and stability of equilibria for three different cases, i.e. with weak Allee effect, with strong Allee effect, and in the critical case. We also investigate the existence and uniqueness of Hopf bifurcation and limit cycle. Secondly, for the model with time delay, the stability of equilibria and the existence of Hopf bifurcation are discussed. All the above show that both additive Allee effect and time delay have vital effects on the prevalence of the disease.
Superbridge and bridge indices for knots
Authors: Adams Colin , Agarwal Nikhil , Allen Rachel , Khandhawit Tirasan , Simons Alex , Winarski Rebecca , Wootters Mary
Published: April 2021

We improve the upper bound on superbridge index [Formula: see text] in terms of bridge index [Formula: see text] from [Formula: see text] to [Formula: see text].
Carboniferous sedimentary provenance and tectonic setting in the Darbut region of Western Junggar (NW China): evidence from mineralogy, geochemistry and detrital zircon U–Pb dating
Authors: Weng Kai , Dong Yunpeng , Xu Xueyi , Ma Zhongping , Chen Bo
Published: April 2021

The Carboniferous tectonic evolution of Western Junggar is crucial to understanding the subduction–accretion process of the Central Asian Orogenic Belt, but the nature of this setting is still controversial. In this work, composite mineralogical, geochemical and detrital zircon U–Pb geochronological investigations have been conducted on Carboniferous clastic rocks in the Darbut region. The chemical compositions and sedimentary features show low sediment maturity and limited recycling, suggesting short-distance transportation and rapid accumulation. The samples contain igneous rock debris, mainly andesite and small amounts of basalt and granite, and a heavy mineral assemblage of Zr + Ap + Aug + Hbl + iron-bearing minerals (Hem-Lm, Ilm, Mag and Py). The samples feature moderate ratios of Zr/Sc (average 15.47) and Th/Sc (average 0.61), and low ratios of La/Sc, Co/Th and La/Th, as well as low Hf content, suggesting intermediate to felsic arc-related igneous provenances. Detrital zircon grains from the clastic rocks show prominent age peaks in the Devonian and Carboniferous with positive

ε

Hf
(
t
) values, indicating a consistent provenance associated with the Tiechanggou–Halaalate island arc. Combining the petrology, geochemistry and geochronology of the sedimentary and magmatic rocks, we conclude that the Darbut Carboniferous volcanic–sedimentary strata were deposited in a back-arc basin during
c.
327–311 Ma.

Supplementary material
: Tables S1-S6 and Figures S1-S6 are available at
https://doi.org/10.6084/m9.figshare.c.5357293
Revised tectonostratigraphy and structural evolution of the Köli Nappe Complex, Central Caledonides in Nordland, Norway
Authors: Saalmann K. , Bjerkgård T. , Slagstad T. , Sandstad J.S. , Lutro O. , Keiding J. , Snook B. , Angvik T.L.
Published: April 2021

The nappe stack in the Røssvatnet–Hattfjelldal region in the Central Norwegian Caledonides consists of seven nappes formed at the boundary between tectonostratigraphically upper and uppermost Caledonian levels. The rocks of all nappes share a polyphase tectonometamorphic evolution that is younger than the 491 ± 10 Ma depositional (volcanic) age of parts of the succession. Early stages of deformation characterized by centimetre- to kilometre-scale folding and intense shearing accompanied by greenschist to amphibolite facies peak metamorphism are correlated with the Early Ordovician Taconian accretionary orogeny along the Laurentian margin. The Taconian structures are cut by the Krutfjellet gabbro and diorite, which yield U–Pb zircon ages of 446 ± 5 and 444 ± 4 Ma, respectively. Large-scale nappe stacking and folding post-dating the emplacement of the gabbro is related to the collision of Laurentia with Baltica (Scandian orogeny) and was followed by late- to post-orogenic extension. The revised tectonostratigraphy assigns the structurally higher nappes to the Uppermost Allochthon, whereas the lower nappes are correlated with the Middle Köli Nappe Complex (Upper Allochthon). The boundary between these nappes is marked by an imbricate zone. Taconian deformation was probably much more penetrative and widespread than hitherto thought and therefore parts of the nappe stack were probably assembled before Scandian collision.

Supplementary material:
Electronic Supplement 1: U–Pb zircon data and Electronic Supplement 2: Methods (laser ablation inductively coupled plasma mass spectrometry U–Pb zircon geochronology) are available at
https://doi.org/10.6084/m9.figshare.c.5357255
Compatibility-Aware Web API Recommendation for Mashup Creation via Textual Description Mining
Authors: Qi Lianyong , Song Houbing , Zhang Xuyun , Srivastava Gautam , Xu Xiaolong , Yu Shui
Published: April 2021

With the ever-increasing prosperity of web Application Programming Interface (API) sharing platforms, it is becoming an economic and efficient way for software developers to design their interested mashups through web API re-use. Generally, a software developer can browse, evaluate, and select his or her preferred web APIs from the API's sharing platforms to create various mashups with rich functionality. The big volume of candidate APIs places a heavy burden on software developers’ API selection decisions. This, in turn, calls for the support of intelligent API recommender systems. However, existing API recommender systems often face two challenges. First, they focus more on the functional accuracy of APIs while neglecting the APIs’ actual compatibility. This then creates incompatible mashups. Second, they often require software developers to input a set of keywords that can accurately describe the expected functions of the mashup to be developed. This second challenge tests partial developers who have little background knowledge in the fields. To tackle the above-mentioned challenges, in this article we propose a compatibility-aware and text description-driven web API recommendation approach (named

WAR
text

).

WAR
text

guarantees the compatibility among the recommended APIs by utilizing the APIs’ composition records produced by historical mashup creations. Besides,

WAR
text

entitles a software developer to type a simple text document that describes the expected mashup functions as input. Then through textual description mining,

WAR
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can precisely capture the developers’ functional requirements and then return a set of APIs with the highest compatibility. Finally, through a real-world mashup dataset ProgrammableWeb, we validate the feasibility of our novel approach.
Zero-shot Cross-modal Retrieval by Assembling AutoEncoder and Generative Adversarial Network
Authors: Xu Xing , Tian Jialin , Lin Kaiyi , Lu Huimin , Shao Jie , Shen Heng Tao
Published: April 2021

Conventional cross-modal retrieval models mainly assume the same scope of the classes for both the training set and the testing set. This assumption limits their extensibility on zero-shot cross-modal retrieval (ZS-CMR), where the testing set consists of unseen classes that are disjoint with seen classes in the training set. The ZS-CMR task is more challenging due to the heterogeneous distributions of different modalities and the semantic inconsistency between seen and unseen classes. A few of recently proposed approaches are inspired by zero-shot learning to estimate the distribution underlying multimodal data by generative models and make the knowledge transfer from seen classes to unseen classes by leveraging class embeddings. However, directly borrowing the idea from zero-shot learning (ZSL) is not fully adaptive to the retrieval task, since the core of the retrieval task is learning the common space. To address the above issues, we propose a novel approach named Assembling AutoEncoder and Generative Adversarial Network (AAEGAN), which combines the strength of AutoEncoder (AE) and Generative Adversarial Network (GAN), to jointly incorporate common latent space learning, knowledge transfer, and feature synthesis for ZS-CMR. Besides, instead of utilizing class embeddings as common space, the AAEGAN approach maps all multimodal data into a learned latent space with the distribution alignment via three coupled AEs. We empirically show the remarkable improvement for ZS-CMR task and establish the state-of-the-art or competitive performance on four image-text retrieval datasets.
Friendly Fire
Authors: Balliu Musard , Merro Massimo , Pasqua Michele , Shcherbakov Mikhail
Published: April 2021

IoT platforms enable users to connect various smart devices and online services via reactive apps running on the cloud. These apps, often developed by third-parties, perform simple computations on data triggered by external information sources and actuate the results of computations on external information sinks. Recent research shows that unintended or malicious interactions between the different (even benign) apps of a user can cause severe security and safety risks. These works leverage program analysis techniques to build tools for unveiling unexpected interference across apps for specific use cases. Despite these initial efforts, we are still lacking a semantic framework for understanding interactions between IoT apps. The question of what security policy cross-app interference embodies remains largely unexplored.

This article proposes a semantic framework capturing the essence of cross-app interactions in IoT platforms. The framework generalizes and connects syntactic enforcement mechanisms to bisimulation-based notions of security, thus providing a baseline for formulating soundness criteria of these enforcement mechanisms. Specifically, we present a calculus that models the behavioral semantics of a system of apps executing concurrently, and use it to define desirable semantic policies targeting the security and safety of IoT apps. To demonstrate the usefulness of our framework, we define and implement static analyses for enforcing cross-app security and safety, and prove them sound with respect to our semantic conditions. We also leverage real-world apps to validate the practical benefits of our tools based on the proposed enforcement mechanisms.
The role of chronic muscle (in)activity on carnosine homeostasis: a study with spinal cord-injured athletes
Authors: Nemezio Kleiner , Yamaguchi Guilherme de Carvalho , Ramkrapes Ana Paula Boito , Schulz Mariane Leichsenring , Baptista Igor Luchini , Riani Luiz Augusto , Gonçalves Lívia de Souza , Sale Craig , Medeiros Marisa Helena Gennari de , Gualano Bruno , Artioli Guilherme Giannini
Published: April 2021

To examine the role of chronic (in)activity on muscle carnosine (MCarn) and how chronic (in)activity affects MCarn responses to β-alanine supplementation in spinal cord-injured athletes, 16 male athletes with paraplegia were randomized (2:1 ratio) to receive β-alanine ( n = 11) or placebo (PL, n = 5). They consumed 6.4 g/day of β-alanine or PL for 28 days. Muscle biopsies of the active deltoid and the inactive vastus lateralis (VL) were taken before and after supplementation. MCarn in the VL was also compared with the VL of a group of individuals without paraplegia ( n = 15). MCarn was quantified in whole muscle and in pools of individual fibers by high-performance liquid chromatography. MCarn was higher in chronically inactive VL vs. well-trained deltoid (32.0 ± 12.0 vs. 20.5 ± 6.1 mmol/kg DM; P = 0.018). MCarn was higher in inactive vs. active VL (32.0 ± 12.0 vs. 21.2 ± 7.5 mmol/kg DM; P = 0.011). In type-I fibers, MCarn was significantly higher in the inactive VL than in the active deltoid (38.3 ± 4.7 vs. 27.3 ± 11.8 mmol/kg DM, P = 0.014). MCarn increased similarly between inactive VL and active deltoid in the β-alanine group (VL: 68.9 ± 55.1%, P = 0.0002; deltoid: 90.5 ± 51.4%, P < 0.0001), with no changes in the PL group. MCarn content was higher in the inactive VL than in the active deltoid and the active VL, but this is probably a consequence of fiber type shift (type I to type II) that occurs with chronic inactivity. Chronically inactive muscle showed an increase in MCarn after BA supplementation equally to the active muscle, suggesting that carnosine accretion following β-alanine supplementation is not influenced by muscle inactivity.
Time-course of V̇o2 kinetics responses during moderate-intensity exercise subsequent to HIIT versus moderate-intensity continuous training in type 2 diabetes
Authors: Gildea Norita , McDermott Adam , Rocha Joel , O’Shea Donal , Green Simon , Egaña Mikel
Published: April 2021

High-intensity interval training and moderate-intensity continuous training elicited faster pulmonary oxygen uptake (V̇o2) kinetics during moderate-intensity cycling within 3 wk of training with no further changes thereafter in individuals with type 2 diabetes. These adaptations were accompanied by unaltered near-infrared spectroscopy-derived muscle deoxygenation (i.e. deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) kinetics and transiently reduced Δ[HHb+Mb]-to-ΔV̇o2 ratio, suggesting an enhanced blood flow distribution within the active muscles subsequent to both training interventions.
Application of Nonarbitrage Pricing Model and Finite Element Numerical Solution in the Value of Convertible Bonds in the Stock Market
Authors: Guo Xiaoxiao
Published: April 2021

Because of its creditor’s rights, equity, and options, convertible bonds have been developed rapidly since its emergence and have become one of the main tools in the financial market. One of the core problems of convertible bonds is pricing. The research on the pricing model of convertible bonds in China is relatively late. Most of them use foreign technologies, but they are quite different from the actual situation in China, and most of the models are characterized by a single factor. Therefore, this paper puts forward the nonarbitrage pricing model in the stock market and the application of the finite element numerical solution in the value of convertible bonds. The biggest innovation of this paper is to design a combined pricing model by using the model of nonarbitrage pricing theory and finite element numerical solution. The model combines the advantages of the nonarbitrage pricing theory and finite element numerical solution, and through the design of this paper, the model effectively improves the calculation accuracy and is suitable for most of the current market environment. While improving the comprehensive performance of the pricing model, it also simplifies the calculation methods and steps. In order to further verify the actual effect of the pricing model in this paper, the traditional binary tree model is taken as the experimental contrast object, including the comparative analysis of the market price and the theoretical price of the convertible bond, the comparative experiment of the prediction effect between the model and the binary tree model, and the analysis of the relative price error of the convertible bond. The results show that the comprehensive performance of the pricing model in this paper is significantly better than the traditional binary tree model. This study has achieved ideal results and can be widely recommended.
Exposure to Intimate Partner Violence and Hypertension Outcomes among Young Women in South Africa
Authors: De Wet-Billings Nicole , Godongwana Motlatso
Published: April 2021

Hypertension and intimate partner violence is affecting longevity and quality of life among women worldwide. In this study, intimate partner violence is identified as a risk factor for hypertension outcomes among young women in South Africa. Using a nationally representative sample of 216 (N) young women (15–34 years old) from the South African Demographic and Health Survey, this study uses cross-tabulations and logistic regression methods to identify the odds of hypertension outcomes. Results show that between 20 and 41% of 15–34-year-old women have hypertension. Further, 68% of women with hypertension experienced physical intimate partner violence. Finally, the odds of hypertension are increased if young women experience physical (OR: 4.07; CI: 1.04726–15.82438) or sexual (OR: 2.56; CI: 1.18198–5.55834) intimate partner violence. Efforts to reduce hypertension outcomes in the country should include intimate partner violence awareness and assistance.
Smarandache Ruled Surfaces according to Frenet-Serret Frame of a Regular Curve in

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Authors: Ouarab Soukaina
Published: April 2021

In this paper, we introduce original definitions of Smarandache ruled surfaces according to Frenet-Serret frame of a curve in

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. It concerns TN-Smarandache ruled surface, TB-Smarandache ruled surface, and NB-Smarandache ruled surface. We investigate theorems that give necessary and sufficient conditions for those special ruled surfaces to be developable and minimal. Furthermore, we present examples with illustrations.
Probiotics Can Further Reduce Waist Circumference in Adults with Morbid Obesity after Bariatric Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Authors: Zhang Yu , Yan Tong , Xu Chenxin , Yang Huawu , Zhang Tongtong , Liu Yanjun
Published: April 2021

Whether probiotics could be used as an adjunct to bariatric surgery is controversial. This meta-analysis aimed to evaluate the effects of probiotics on body weight, body mass index (BMI), percentage of the excess weight loss (%EWL), waist circumference (WC), and C-reactive protein (CRP) in adults with obesity after bariatric surgery (BS). PUBMED, EMBASE, and the Cochrane Central Registry of Controlled Trials were searched from the earliest record to March 2020. All randomized controlled trials (RCTs) on the effects of probiotics in adults with obesity after bariatric surgery were analyzed according to the eligibility criteria. Four RCTs, including 172 participants, were analyzed. There was a statistically significant difference in probiotics in the reduction of waist circumference at 12 months after bariatric surgery. However, probiotics were not effective in weight, BMI, %EWL, WC, and CRP both within 3 months and at 12 months postoperation. Probiotics aid adults with morbid obesity in achieving further waist circumference improvement after BS, with no significant effect on weight, BMI, %EWL, and CRP. More quality clinical studies are needed to confirm the efficacy and safety of probiotics, and address a number of practical issues before the routine clinical use of probiotics in adults with obesity undergoing BS.