bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of proximity and accessibility drivers in simulating dynamic urban growth
Authors: Wang Rong , Feng Yongjiu , Wei Yongliang , Tong Xiaohua , Zhai Shuting , Zhou Yilun , Wu Peiqi
Published: November 2020

Dynamic urban growth is affected by various driving factors which are important for building cellular automata (CA) models. Two categories of urban‐growth drivers (i.e., proximity and accessibility) have not been well differentiated in simulating urban patterns. We built two CA models (Pro‐CAPSO and Acc‐CAPSO) using particle swarm optimization (PSO) incorporating the proximity and accessibility drivers and applied these models to simulate urban growth at Zhuji in China. The results show that although both models accurately reproduced urban growth from 2005 to 2015, differences in the allocation of urban cells are apparent. The proximity‐based model yielded a slightly better figure of merit (FOM) of 19.3% during calibration (2005–2010) as compared to the accessibility‐based model with FOM of 17.5%. An opposite trend (FOM 17.5% vs. 18.3%) was found for subsequent validation (2010–2015). The simulations by the Acc‐CAPSO model are closer to the real urban patterns as measured by landscape metrics. The results indicate that accessibility is a relatively robust driver in predicting long‐term future urban growth. For specific regions, urban future scenarios produced by the two models show opposing patterns; in the same areas, when Pro‐CAPSO predicted more new urban cells, Acc‐CAPSO predicted fewer, and vice versa. Our methods are useful for modelers in selecting appropriate factors between proximity and accessibility and arrange the combination to represent human disturbance when simulating urban growth.
Classification of universal formality maps for quantizations of Lie bialgebras
Authors: Merkulov Sergei , Willwacher Thomas
Published: November 2020

We settle several fundamental questions about the theory of universal deformation quantization of Lie bialgebras by giving their complete classification up to homotopy equivalence. Moreover, we settle these questions in a greater generality: we give a complete classification of the associated universal formality maps. An important new technical ingredient introduced in this paper is a polydifferential endofunctor ${\mathcal {D}}$ in the category of augmented props with the property that for any representation of a prop ${\mathcal {P}}$ in a vector space $V$ the associated prop ${\mathcal {D}}{\mathcal {P}}$ admits an induced representation on the graded commutative algebra $\odot ^\bullet V$ given in terms of polydifferential operators. Applying this functor to the minimal resolution $\widehat {\mathcal {L}\textit{ieb}}_\infty$ of the genus completed prop $\widehat {\mathcal {L}\textit{ieb}}$ of Lie bialgebras we show that universal formality maps for quantizations of Lie bialgebras are in one-to-one correspondence with morphisms of dg props
\[F: \mathcal{A}\textit{ssb}_\infty \longrightarrow {\mathcal{D}}\widehat{\mathcal{L}\textit{ieb}}_\infty \]
satisfying certain boundary conditions, where $\mathcal {A}\textit{ssb}_\infty$ is a minimal resolution of the prop of associative bialgebras. We prove that the set of such formality morphisms is non-empty. The latter result is used in turn to give a short proof of the formality theorem for universal quantizations of arbitrary Lie bialgebras which says that for any Drinfeld associator $\mathfrak{A}$ there is an associated ${\mathcal {L}} ie_\infty$ quasi-isomorphism between the ${\mathcal {L}} ie_\infty$ algebras $\mathsf {Def}({\mathcal {A}} ss{\mathcal {B}}_\infty \rightarrow {\mathcal {E}} nd_{\odot ^\bullet V})$ and $\mathsf {Def}({\mathcal {L}} ie{\mathcal {B}}\rightarrow {\mathcal {E}} nd_V)$ controlling, respectively, deformations of the standard bialgebra structure in $\odot V$ and deformations of any given Lie bialgebra structure in $V$. We study the deformation complex of an arbitrary universal formality morphism $\mathsf {Def}(\mathcal {A}\textit{ssb}_\infty \stackrel {F}{\rightarrow } {\mathcal {D}}\widehat {\mathcal {L}\textit{ieb}}_\infty )$ and prove that it is quasi-isomorphic to the full (i.e. not necessary connected) version of the graph complex introduced Maxim Kontsevich in the context of the theory of deformation quantizations of Poisson manifolds. This result gives a complete classification of the set $\{F_\mathfrak{A}\}$ of gauge equivalence classes of universal Lie connected formality maps: it is a torsor over the Grothendieck–Teichmüller group $GRT=GRT_1\rtimes {\mathbb {K}}^*$ and can hence can be identified with the set $\{\mathfrak{A}\}$ of Drinfeld associators.
Myths and methodologies: Reliability of forearm cutaneous vasodilatation measured using laser‐Doppler flowmetry during whole‐body passive heating
Authors: Gemae Mohamed R. , Akerman Ashley P. , McGarr Gregory W. , Meade Robert D. , Notley Sean R. , Schmidt Madison D. , Rutherford Maura M. , Kenny Glen P.
Published: November 2020

Laser‐Doppler flowmetry (LDF) is commonly used to assess cutaneous vasodilatation responses, but its reliability (i.e. consistency) during whole‐body passive heating is unknown. We therefore assessed the reliability of LDF‐derived indices of cutaneous vasodilatation during incremental whole‐body heating. Fourteen young men (age: 24 (SD 5) years) completed three identical trials, each separated by 1 week. During each trial, a water‐perfused suit was used to raise and clamp oesophageal temperature at 0.6°C (low‐heat strain; LHS) and 1.2°C (moderate‐heat strain; MHS) above baseline. LDF‐derived skin blood flow (SkBF) was measured at three dorsal mid‐forearm sites, with local skin temperature clamped at 34°C. Data were expressed as absolute cutaneous vascular conductance (CVCabs; SkBF/mean arterial pressure) and normalised to maximal conductance (%CVCmax) achieved via simultaneous local skin heating to 44°C and increasing oesophageal temperature to 1.8°C above baseline. Between‐day reliability was characterised as measurement consistency across trials, while within‐day reliability was characterised as measurement consistency across adjacent skin sites during each trial. Between‐ and within‐day absolute reliability (coefficient of variation) generally improved with increasing heat strain, changing from poor (>25%) at baseline, poor‐to‐moderate (15–34%) at LHS, and moderate (10–25%) at MHS. Generally, these estimates were more consistent when expressed as %CVCmax. Conversely, relative reliability was mostly acceptable (intraclass correlation coefficient ≥0.70) during LHS and when data were expressed as CVCabs. These findings indicate that the consistency of LDF‐derived CVC estimates during heat stress depends on the level of heat strain and method of data expression, which should be considered when designing and interpreting experiments.
Arecibo radio telescope to be decommissioned
Authors: Clery Daniel
Published: November 2020

Famed observatory set for demolition after cable failures put it on the brink of collapse.
Study homes in on ‘exceptional responders’ to cancer drugs
Authors: Kaiser Jocelyn
Published: November 2020

Project reveals clues to why some patients respond much better than others.
Potential signs of life on Venus are fading fast
Authors: Voosen Paul
Published: November 2020

Amid mounting criticism, claims for cloud-borne phosphine are downgraded.
Public needs to prep for vaccine side effects
Authors: Wadman Meredith
Published: November 2020

"Take Tylenol and suck it up," says one researcher. Fever, aches show vaccine works.
Individual heterozygosity predicts translocation success in threatened desert tortoises
Authors: Scott Peter A. , Allison Linda J. , Field Kimberleigh J. , Averill-Murray Roy C. , Shaffer H. Bradley
Published: November 2020

Survival of the most variable

As more species become highly threatened because of human activity, there has been an increasing push to understand how best to reintroduce or translocate individuals from wild or captive populations. Suggestions have varied from choosing individuals from the most environmentally similar regions to choosing those that might have the best ability to adapt to new environments. Scott
et al.
used long-term data collected during translocations of Mojave Desert tortoises, including animals formerly kept as pets, to test these questions. Although the overall rates of survival for all tortoises at the site (both reintroduced and native) were extremely low, translocated individuals with the highest heterozygosity survived at much higher rates than those determined to be similar to the target population.

Science
, this issue p.
1086
Capturing roaming molecular fragments in real time
Authors: Endo Tomoyuki , Neville Simon P. , Wanie Vincent , Beaulieu Samuel , Qu Chen , Deschamps Jude , Lassonde Philippe , Schmidt Bruno E. , Fujise Hikaru , Fushitani Mizuho , Hishikawa Akiyoshi , Houston Paul L. , Bowman Joel M. , Schuurman Michael S. , Légaré François , Ibrahim Heide
Published: November 2020

Roaming dynamics in real time

Roaming is distinct from conventional reaction channels because of the unusual geometries that chemical systems use to bypass the minimum energy pathway. It is a relatively new phenomenon that is usually determined in experiments through spectroscopic characterization of the roaming products. Using a combination of time-resolved Coulomb explosion imaging and quasiclassical trajectory analysis, Endo
et al.
report real-time observation of individual fragments of the prototypical reaction of deuterated formaldehyde (D
2
CO) dissociation as they roam on ultrafast time scales. They show that roaming not only occurs several orders of magnitude earlier than previously expected but also that it can terminate in a radical (D + DCO) rather than the well-known molecular (D
2
+ CO) product channel.

Science
, this issue p.
1072
Cost-effectiveness of new antiviral treatments for non-genotype 1 hepatitis C virus infection in China: a societal perspective
Authors: Wei Xia , Zhao Jingyu , Yang Li
Published: November 2020

Objective

This study aimed to estimate the cost-effectiveness of direct-acting antivirals (DAAs) among patients with non-genotype 1 for the eradication of hepatitis C virus (HCV) infection in China.

Methods

A decision-analytic Markov model was developed to estimate the lifetime costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) for DAAs and pegylated interferon plus ribavirin (PEG-RBV) from a societal perspective. The model inputs were derived from the literature, a patient survey, HCV expert opinions and a specialised drug price database available in China. Sensitivity analysis was conducted to evaluate the model robustness and calculate reasonable prices of DAAs.

Results

For patients infected with HCV genotype 2, the pan-genotypic regimen sofosbuvir/velpatasvir (SOF/VEL) was the most cost-effective strategy compared with PEG-RBV, with an ICER of US$5653/QALY. For genotype 3, the combination of sofosbuvir plus daclatasvir (SOF-DCV) was the most cost-effective approach, with an ICER of US$3314/QALY. All DAA regimens for genotype 6 were cost-saving, and sofosbuvir plus ribavirin (SOF-RBV) was the optimal regimen. One-way sensitivity analysis demonstrated that the ICERs were most sensitive to the utility values, discount rate and drug costs. Probabilistic sensitivity analysis indicated that using a threshold equal to one time the gross domestic product (GDP) per capita in China (US$9769/QALY, 2018), the probability of SOF/VEL, SOF-DCV and SOF-RBV being cost-effective was 58%, 83% and 71% for genotype 2, 3 and 6, respectively. Threshold analysis showed that the price of DAAs should be reduced by some degree to achieve better affordability.

Conclusions

DAAs were cost-effective compared with traditional treatments. A reasonable reduction in the price of DAAs will increase drug affordability and is of great significance as a global strategy to eradicate viral hepatitis.
International observational atopic dermatitis cohort to follow natural history and treatment course: TARGET-DERM AD study design and rationale
Authors: Abuabara Katrina , Silverberg Jonathan I , Simpson Eric L , Paller Amy S , Eichenfield Lawrence F. , Bissonnette Robert , Krueger James , Harris John E. , Dalfonso Laura , Watkins Stephanie E , Crawford Julie M , Thaçi D , Guttman-Yassky Emma
Published: November 2020

Introduction

As new topical and systemic treatments become available for atopic dermatitis (AD), there is a need to understand how treatments are being used in routine clinical practice, their comparative effectiveness and their long-term safety in diverse clinical settings.

Methods and analysis

The TARGET-DERM AD cohort is a longitudinal, observational study of patients with AD of all ages, designed to provide practical information on long-term effectiveness and safety unobtainable in traditional registration trials. Patients with physician-diagnosed AD receiving prescription treatment (topical or systemic) will be enrolled at academic and community clinical centres. Up to 3 years of retrospective medical records, 5 years of prospective medical records, and optional biological samples and patient-reported outcomes will be collected. The primary aims include characterisation of AD treatment regimens, evaluation of response to therapy, and description of adverse events.

Ethics and dissemination

TARGET-DERM has been approved by a central IRB (Copernicus Group IRB, 5000 Centregreen Way Suite 200, Cary, North Carolina 27513) as well as local and institutional IRBs. No additional Ethics Committee reviews. Results will be reviewed by a publications committee and submitted to peer-reviewed journals.

Trial registration number

NCT03661866, pre-results.
Promotion or education: a content analysis of industry-authored oral health educational materials targeted at acute care nurses
Authors: Grundy Quinn , Millington Anna , Cussen Cliodna , Held Fabian , Dale Craig M
Published: November 2020

Objectives

To assess the nature, quality and independence of scientific evidence provided in support of claims in industry-authored educational materials in oral health.

Design

A content analysis of educational materials authored by the four major multinational oral health product manufacturers.

Setting

Acute care settings.

Participants

68 documents focused on oral health or oral care, targeted at acute care clinicians and identified as ‘educational’ on companies’ international websites.

Main outcome measures

Data were extracted in duplicate for three areas of focus: (a) products referenced in the documents, (b) product-related claims and (c) citations substantiating claims. We assessed claim–citation pairs to determine if information in the citation supported the claim. We analysed the inter-relationships among cited authors and companies using social network analysis.

Results

Documents ranged from training videos to posters to brochures to continuing education courses. The majority of educational materials explicitly mentioned a product (59/68, 87%), a branded product (35/68, 51%), and made a product-related claim (55/68, 81%). Among claims accompanied by a citation, citations did not support the majority (91/147, 62%) of claims, largely because citations were unrelated. References used to support claims most often represented lower levels of evidence: only 9% were systematic reviews (7/76) and 13% were randomised controlled trials (10/76). We found a network of 20 authors to account for 37% (n=77/206) of all references in claim–citation pairs; 60% (12/20) of the top 20 cited authors received financial support from one of the four sampled manufacturers.

Conclusions

Resources to support clinicians’ ongoing education are scarce. However, caution should be exercised when relying on industry-authored materials to support continuing education for oral health. Evidence of sponsorship bias and reliance on key opinion leaders suggests that industry-authored educational materials have promotional intent and should be regulated as such.
Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study: sequential mixed-methods study protocol in Michigan, USA
Authors: Salhi Rama A , Fouche Sydney , Mendel Peter , Nelson Christopher , Fetters Michael D , Guetterman Timothy , Forman Jane , Nham Wilson , Goldstick Jason E , Lehrich Jessica , Forbush Bill , Iovan Samantha , Hsu Antony , Shields Theresa A , Domeier Robert , Setodji Claude M , Neumar Robert W ,   CARES Surveillance Group, Nallamothu Brahmajee K , Abir Mahshid
Published: November 2020

Introduction

Out-of-hospital cardiac arrest (OHCA) is a common, life-threatening event encountered routinely by first responders, including police, fire and emergency medical services (EMS). Current literature suggests that there is significant regional variation in outcomes, some of which may be related to modifiable factors. Yet, there is a persistent knowledge gap regarding strategies to guide quality improvement efforts in OHCA care and, by extension, survival. The Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study aims to fill these gaps and to improve outcomes.

Methods and analysis

This mixed-methods study includes three aims. In aim I, we will define variation in OHCA survival to the emergency department (ED) among EMS agencies that participate in the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) in order to sample EMS agencies with high-survival and low-survival outcomes. In aim II, we will conduct site visits to emergency medical systems—including 911/dispatch, police, non-transport fire, and EMS agencies—in approximately eight high-survival and low-survival communities identified in aim I. At each site, key informant interviews and a multidisciplinary focus group will identify themes associated with high OHCA survival. Transcripts will be coded using a structured codebook and analysed through thematic analysis. Results from aims I and II will inform the development of a survey instrument in aim III that will be administered to all EMS agencies in Michigan. This survey will test the generalisability of factors associated with increased OHCA survival in the qualitative work to ultimately build an EPOC Toolkit which will be distributed to a broad range of stakeholders as a practical ‘how-to’ guide to improve outcomes.

Ethics and dissemination

The EPOC study was deemed exempt by the University of Michigan Institutional Review Board. Findings will be compiled in an ‘EPOC Toolkit’ and disseminated in the USA through partnerships including, but not limited to, policymakers, EMS leadership and health departments.
The Biathlon Injury and Illness Surveillance (BIIS) project protocol: a prospective cohort study across two World Cup seasons
Authors: Fitzpatrick Jane , Panagodage Perera Nirmala
Published: November 2020

Introduction

Reliably and accurately establishing injury and illness epidemiology in biathletes will provide insight into seasonal changes, provide potential to better embed innovative prevention strategies and advance sports medicine through the provision of effective healthcare to biathletes. The main objective of the Biathlon Injury and Illness Study (BIIS) is to provide the first comprehensive epidemiological profile of injury and illness in biathlon athletes during two consecutive Biathlon World Cup seasons over 2-years.

Methods

The BIIS study methodology is established in line with the International Olympic Committee (IOC) injury and illness surveillance protocols using a biathlon-specific injury and illness report form. Team medical staff will provide weekly data using injury and illness definitions of any injury or illness that receives medical attention regardless of time loss. Injuries or illness must be diagnosed and reported by a qualified medical professional (eg, team physician, physiotherapist) to ensure accurate and reliable diagnoses. Descriptive statistics will be used to identify the type, body region and nature of the injury or illness and athlete demographics such as age and gender. Summary measures of injury and illnesses per 1000 athlete-days will be calculated whereby the total number of athletes will be multiplied by the number of days in the season to calculate athlete-days.

Ethics and Dissemination

This study has been approved by the Bellbery Human Research Ethics Committee (HREC reference: 2017-10-757). Results will be published irrespective of negative or positive outcomes and disseminated through different platforms to reach a wide range of stakeholders.
Gasping for air: measuring patient education and activation skillsets in two clinical assessment contexts
Authors: Wilhite Jeffrey A , Fisher Harriet , Altshuler Lisa , Cannell Elisabeth , Hardowar Khemraj , Hanley Kathleen , Gillespie Colleen , Zabar Sondra
Published: November 2020

Objective structured clinical examinations (OSCEs) provide a controlled, simulated setting for competency assessments, while unannounced simulated patients (USPs) measure competency in situ or real-world settings. This exploratory study describes differences in primary care residents’ skills when caring for the same simulated patient case in OSCEs versus in a USP encounter. Data reported describe a group of residents (n=20) who were assessed following interaction with the same simulated patient case in two distinct settings: an OSCE and a USP visit at our safety-net clinic from 2009 to 2010. In both scenarios, the simulated patient presented as an asthmatic woman with limited understanding of illness management. Residents were rated through a behaviourally anchored checklist on visit completion. Summary scores (mean % well done) were calculated by domain and compared using paired sample t-tests. Residents performed significantly better with USPs on 7 of 10 items and in two of three aggregate assessment domains (p<0.05). OSCE structure may impede assessment of activation and treatment planning skills, which are better assessed in real-world settings. This exploration of outcomes from our two assessments using the same clinical case lays a foundation for future research on variation in situated performance. Using both assessments during residency will provide a more thorough understanding of learner competency.
Non-diabetic ketoacidosis: a case series and literature review
Authors: Bashir Bilal , Fahmy Ahmed A , Raza Farheen , Banerjee Moulinath
Published: November 2020

The genesis of ketone bodies by organisms is a protective mechanism. This metabolic process helps organisms to survive acute metabolic derangements in times of nutrient deficiency. When prolonged, ketogenesis leads to ketoacidosis, which is a potentially life-threatening metabolic disorder due to the accumulation of keto-acids in the body. The most common cause is diabetic ketoacidosis, though starvation ketoacidosis and alcoholic ketoacidosis are not uncommon. The presentation of all ketoacidotic states is similar—being generally unwell, abdominal pain, rapid and shallow breathing, vomiting and dehydration. Non-diabetic ketoacidotic states are very commonly overlooked due to relative unawareness among the clinicians, leading to misdiagnosis and thereby inappropriate management culminating in added mortality and morbidity. We describe here six cases of alcoholic and starvation ketoacidosis, review the literature currently available and discuss the common pitfalls in managing such cases.
‘We need to do more than just stick the Good Veterinary Workplaces policy up in practices’
Authors: Jones Peter Harlech
Published: November 2020

Peter Harlech Jones argues that although publication of this new BVA policy is a great first step to improving working environments, more needs to be done to ensure it will succeed in making a difference.
The mechanism behind BAF60c in myocardial metabolism in rats with heart failure is through the PGC1α-PPARα-mTOR signaling pathway
Authors: Chen Qiang , Chen Lizhu , Jian Jianguo , Li Junping , Zhang Xiaomiao
Published: November 2020

Metabolic remodeling in heart failure (HF) is a type of overload cardiomyopathy caused by insufficient energy supply or an imbalance of glucose and lipid metabolism. Therefore, metabolic pathways may serve as potential targets for HF treatment. BRM-associated factor (BAF) 60c (also known as smarcd3) promotes the transformation of oxidative muscle fibers to glycolytic muscle fibers. Our study aimed to test whether BAF60c and the PGC1α–PPARα–mTOR pathway interact to affect myocardial metabolism in HF rats. Established rat models of HF were injected with BAF60c low or overexpression plasmids to assess cardiac contractile proteins, energy metabolism, oxidative metabolism, glycolysis, high-energy phosphate content, mitochondrial function, and apoptosis. BAF60c overexpression/siRNA plasmid was transfected into H9C2 cells. These results suggest that HF rats present decreased levels of BAF60c, increased glycolysis, and reduced levels of cardiac contractile proteins, PGC1α, PPARα, and oxidative metabolism. Overexpression of BAF60c maintained the balance between oxidative metabolism and glycolysis and activated the PGC1α-PPARα-mTOR pathway. PGC1α interacted with BAF60c, and overexpression of PGC1α decreased BAF60c knockdown, damaging H9C2 cells. Collectively, overexpression of BAF60c activated the PGC1α-PPARα-mTOR pathway, maintained the oxidative metabolism/glycolysis balance, and improved mitochondrial function in HF rats. This study offers novel insights into HF treatment.
Live load factors for military traffic in bridge evaluation
Authors: MacDonald Andrew James , Bartlett F. Michael , Wight R. Gordon
Published: November 2020

Military vehicles are sometimes required to transit bridges owned and operated by civilian bridge authorities. Using available data regarding the gross vehicle weight and associated axle loads of military traffic, live load factors, calibrated to the Canadian Highway Bridge Design Code, are proposed for bridge design and evaluation. This paper recommends live load factors for three categories of military vehicles: (i) wheeled-transport vehicles; (ii) wheeled-fighting vehicles; and (iii) tracked-fighting vehicles. The values are derived for interior girders of simply supported slab-on-girder bridges subjected to a single lane of traffic loading and are believed to be generally applicable for other structural elements and bridge types. Inherent differences between fighting vehicles, which are heavily armoured, and transport vehicles, which although armoured have high payloads, suggest that highway bridges should be evaluated separately for military fighting vehicles and military transport vehicles using distinct live load factors.
CF3-substituted diselenide modulatory effects on oxidative stress, induced by single and repeated morphine administrations, in susceptible tissues of mice
Authors: Rodrigues Renata F. , Martins Carolina C. , Rosa Suzan G. , Nogueira Cristina W.
Published: November 2020

Studies reveal that oxidative stress is associated with adverse effects of long-term morphine treatment. The m-trifluoromethyl-diphenyl diselenide (CF3) is a multi-target organoselenium compound that has antioxidant properties in different experimental models. This study aimed to investigate the CF3 effects against redox imbalance in peripheral and central tissues of mice, after single or multiple morphine doses. Swiss male mice received a single dose of morphine (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.), or morphine was repeatedly injected (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.) administered twice daily for 7 days. Oxidative stress was determined in the hippocampus, liver, and kidney. CF3 reversed the increase in reactive species caused by single and multiple morphine doses in the peripheral tissues. CF3 increased hepatic non-protein thiol levels and the superoxide dismutase (SOD) activity decreased by a single morphine dose. CF3 reversed the reduction in SOD activity in the kidney of mice repeatedly exposed to morphine. The study demonstrates that peripheral tissues were more susceptible than the hippocampus to oxidative stress induced by morphine in mice. The results show that CF3 modulated parameters of oxidative stress modified by single and multiple morphine administrations in peripheral and central tissues of mice.
Primate-specific histone variants
Authors: Ding Dongbo , Nguyen Thi Thuy , Pang Matthew Y.H. , Ishibashi Toyotaka
Published: November 2020

Canonical histones (H2A, H2B, H3, and H4) are present in all eukaryotes where they package genomic DNA and participate in numerous cellular processes, such as transcription regulation and DNA repair. In addition to the canonical histones, there are many histone variants, which have different amino acid sequences, possess tissue-specific expression profiles, and function distinctly from the canonical counterparts. A number of histone variants, including both core histones (H2A/H2B/H3/H4) and linker histones (H1/H5), have been identified to date. Htz1 (H2A.Z) and CENP-A (CenH3) are present from yeasts to mammals, and H3.3 is present from Tetrahymena to humans. In addition to the prevalent variants, others like H3.4 (H3t), H2A.Bbd, and TH2B, as well as several H1 variants, are found to be specific to mammals. Among them, H2BFWT, H3.5, H3.X, H3.Y, and H4G are unique to primates (or Hominidae). In this review, we focus on localization and function of primate- or hominidae-specific histone variants.
A New Dynamic Stall Approach for Investigating Bifurcation and Chaos in Aeroelastic Response of a Blade Section with Flap Free-Play Section
Authors: Esbati Lavasani Reza , Shams Shahrokh
Published: November 2020

This paper investigates the effects of the unsteady nonlinear aerodynamic, plunge/pitch cubic nonlinearities, flap free-play nonlinearity, and coupled nonlinear aeroelasticity on the dynamics of the three-dimensional blade section. The dynamic stall model is developed based on the unsteady Wagner aerodynamics. Coupling the developed nonlinear aerodynamic model and nonlinear elasticity model results in the nonlinear aeroelastic model. The nonlinear aeroelastic equation of motion is converted into a state-space form. The resulting nonlinear state-space equation of motion is simulated by a standard Runge–Kutta algorithm in MATLAB. The proposed model is validated against test data of distinct two- and three-degrees-of-freedom studies and is compared to the ONERA model. Bifurcation diagrams show that there is distinct airspeed, in which the system experiences limit cycle oscillations (LCOs) or chaos. Both hysteresis air loads and structural nonlinearity make the system unstable at airspeed less than linear flutter speed. The nonlinearity of the structure causes supercritical pitchfork bifurcation. Elastic-aerodynamic nonlinearity interaction causes sub-supercritical bifurcation at the lower airspeed and chaotic motion at a higher airspeed. Furthermore, the effects of the initial condition on the response of the nonlinear aero-servo-elastic system are investigated by the Lyapunov exponent method.
Sliding Bifurcations in the Memristive Murali–Lakshmanan–Chua Circuit and the Memristive Driven Chua Oscillator
Authors: Ahamed A. Ishaq , Lakshmanan M.
Published: November 2020

In this paper, we report the occurrence of sliding bifurcations admitted by the memristive Murali–Lakshmanan–Chua circuit [Ishaq & Lakshmanan, 2013] and the memristive driven Chua oscillator [Ishaq et al., 2011]. Both of these circuits have a flux-controlled active memristor designed by the authors in 2011, as their nonlinear element. The three-segment piecewise-linear characteristic of this memristor bestows on the circuits two discontinuity boundaries, dividing their phase spaces into three subregions. For proper choice of parameters, these circuits take on a degree of smoothness equal to one at each of their two discontinuities, thereby causing them to behave as Filippov systems. Sliding bifurcations, which are characteristic of Filippov systems, arise when the periodic orbits in each of the subregions, interact with the discontinuity boundaries, giving rise to many interesting dynamical phenomena. The numerical simulations are carried out after incorporating proper zero time discontinuity mapping (ZDM) corrections. These are found to agree well with the experimental observations which we report here appropriately.
Homoclinic Orbits and Solitary Waves within the Nondissipative Lorenz Model and KdV Equation
Authors: Shen Bo-Wen
Published: November 2020

Recent studies using the classical Lorenz model and generalized Lorenz models present abundant features of both chaotic and oscillatory solutions that may change our view on the nature of the weather as well as climate. In this study, the mathematical universality of solutions in different physical systems is presented. Specifically, the main goal is to reveal mathematical similarities for solutions of homoclinic orbits and solitary waves within a three-dimensional nondissipative Lorenz model (3D-NLM), the Korteweg–de Vries (KdV) equation, and the Nonlinear Schrodinger (NLS) equation. A homoclinic orbit for the [Formula: see text], [Formula: see text], and [Formula: see text] state variables of the 3D-NLM connects the unstable and stable manifolds of a saddle point. The [Formula: see text] and [Formula: see text] solutions for the homoclinic orbit can be expressed in terms of a hyperbolic secant function ([Formula: see text]) and a hyperbolic secant squared function ([Formula: see text]), respectively. Interestingly, these two solutions have the same mathematical form as solitary solutions for the NLS and KdV equations, respectively. After introducing new independent variables, the same second-order ordinary differential equation (ODE) and solutions for the [Formula: see text] component and the KdV equation were obtained. Additionally, the ODE for the [Formula: see text] component has the same form as the NLS for the solitary wave envelope. Finally, how a logistic equation, also known as the Lorenz error growth model, and an improved error growth model can be derived by simplifying the 3D-NLM is also discussed. Future work will compare the solutions of the 3D-NLM and KdV equation in order to understand the different physical role of nonlinearity in their solutions and the solutions of the error growth model and the 3D-NLM, as well as other Lorenz models, to propose an improved error growth model for better representing error growth at linear and nonlinear stages for both oscillatory and nonoscillatory solutions.
Data-Driven Business Model Innovation: About Barriers and New Perspectives
Authors: Mosig Tim , Lehmann Claudia , Neyer Anne-Katrin
Published: November 2020

Today, data are increasing in importance for firms trying to create and maintain a competitive advantage. As value creation is highly dependent on this key resource, data, the necessity of re-designing firms’ business models arises. By conducting and analyzing 58 in-depth interviews, we contribute a distinct set of barriers to data-driven business model innovation showing how data-related, technology-related, aversions and regulatory hurdles are the most challenging. Based on six focus groups that discussed these findings, participants identified the necessity for a change in companies’ firm-centered perspectives on business. Hence, we propose a model of data-driven business ecosystems that aims to provide guidance for conducting successful business in a data-driven world.
ADD
Authors: Geilinger Moritz , Hahn David , Zehnder Jonas , Bächer Moritz , Thomaszewski Bernhard , Coros Stelian
Published: November 2020

We present a differentiable dynamics solver that is able to handle frictional contact for rigid and deformable objects within a unified framework. Through a principled mollification of normal and tangential contact forces, our method circumvents the main difficulties inherent to the non-smooth nature of frictional contact. We combine this new contact model with fully-implicit time integration to obtain a robust and efficient dynamics solver that is analytically differentiable. In conjunction with adjoint sensitivity analysis, our formulation enables gradient-based optimization with adaptive trade-offs between simulation accuracy and smoothness of objective function landscapes. We thoroughly analyse our approach on a set of simulation examples involving rigid bodies, visco-elastic materials, and coupled multi-body systems. We furthermore showcase applications of our differentiable simulator to parameter estimation for deformable objects, motion planning for robotic manipulation, trajectory optimization for compliant walking robots, as well as efficient self-supervised learning of control policies.
Scene mover
Authors: Wang Hanqing , Liang Wei , Yu Lap-Fai
Published: November 2020

We propose a novel approach for automatically generating a move plan for scene arrangement.
1
Given a scene like an apartment with many furniture objects, to transform its layout into another layout, one would need to determine a collision-free move plan. It could be challenging to design this plan manually because the furniture objects may block the way of each other if not moved properly; and there is a large complex search space of move action sequences that grow exponentially with the number of objects. To tackle this challenge, we propose a learning-based approach to generate a move plan automatically. At the core of our approach is a Monte Carlo tree that encodes possible states of the layout, based on which a search is performed to move a furniture object appropriately in the current layout. We trained a policy neural network embedded with a LSTM module for estimating the best actions to take in the expansion step and simulation step of the Monte Carlo tree search process. Leveraging the power of deep reinforcement learning, the network learned how to make such estimations through millions of trials of moving objects. We demonstrated our approach for moving objects under different scenarios and constraints. We also evaluated our approach on synthetic and real-world layouts, comparing its performance with that of humans and other baseline approaches.
RBF liquids
Authors: Nakanishi Rafael , Nascimento Filipe , Campos Rafael , Pagliosa Paulo , Paiva Afonso
Published: November 2020

We introduce a novel liquid simulation approach that combines a spatially adaptive pressure projection solver with the Particle-in-Cell (PIC) method. The solver relies on a generalized version of the Finite Difference (FD) method to approximate the pressure field and its gradients in tree-based grid discretizations, possibly non-graded. In our approach, FD stencils are computed by using meshfree interpolations provided by a variant of Radial Basis Function (RBF), known as RBF-Finite-Difference (RBF-FD). This meshfree version of the FD produces differentiation weights on scattered nodes with high-order accuracy. Our method adapts a quadtree/octree dynamically in a narrow-band around the liquid interface, providing an adaptive particle sampling for the PIC advection step. Furthermore, RBF affords an accurate scheme for velocity transfer between the grid and particles, keeping the system's stability and avoiding numerical dissipation. We also present a data structure that connects the spatial subdivision of a quadtree/octree with the topology of its corresponding dual-graph. Our data structure makes the setup of stencils straightforward, allowing its updating without the need to rebuild it from scratch at each time-step. We show the effectiveness and accuracy of our solver by simulating incompressible inviscid fluids and comparing results with regular PIC-based solvers available in the literature.
MapTree
Authors: Ren Jing , Melzi Simone , Ovsjanikov Maks , Wonka Peter
Published: November 2020

In this paper we propose an approach for computing multiple high-quality near-isometric dense correspondences between a pair of 3D shapes. Our method is fully automatic and does not rely on user-provided landmarks or descriptors. This allows us to analyze the full space of maps and extract multiple diverse and accurate solutions, rather than optimizing for a single optimal correspondence as done in most previous approaches. To achieve this, we propose a compact tree structure based on the spectral map representation for encoding and enumerating possible rough initializations, and a novel efficient approach for refining them to dense pointwise maps. This leads to a new method capable of both producing multiple high-quality correspondences across shapes and revealing the symmetry structure of a shape without a priori information. In addition, we demonstrate through extensive experiments that our method is robust and results in more accurate correspondences than state-of-the-art for shape matching and symmetry detection.
A moving least square reproducing kernel particle method for unified multiphase continuum simulation
Authors: Chen Xiao-Song , Li Chen-Feng , Cao Geng-Chen , Jiang Yun-Tao , Hu Shi-Min
Published: November 2020

In physically based-based animation, pure particle methods are popular due to their simple data structure, easy implementation, and convenient parallelization. As a pure particle-based method and using Galerkin discretization, the Moving Least Square Reproducing Kernel Method (MLSRK) was developed in engineering computation as a general numerical tool for solving PDEs. The basic idea of Moving Least Square (MLS) has also been used in computer graphics to estimate deformation gradient for deformable solids. Based on these previous studies, we propose a multiphase MLSRK framework that animates complex and coupled fluids and solids in a unified manner. Specifically, we use the Cauchy momentum equation and phase field model to uniformly capture the momentum balance and phase evolution/interaction in a multiphase system, and systematically formulate the MLSRK discretization to support general multiphase constitutive models. A series of animation examples are presented to demonstrate the performance of our new multiphase MLSRK framework, including hyperelastic, elastoplastic, viscous, fracturing and multiphase coupling behaviours etc.
DHFSlicer
Authors: Yang Jinfan , Araujo Chrystiano , Vining Nicholas , Ferguson Zachary , Rosales Enrique , Panozzo Daniele , Lefevbre Sylvain , Cignoni Paolo , Sheffer Alla
Published: November 2020

3-axis milling enables cheap and precise fabrication of target objects from precut slabs of materials such as wood or stone. However, the space of directly millable shapes is limited since a 3-axis mill can only carve a height-field (HF) surface during each milling and their size is bounded by the slab dimensions, one of which, the
height
, is typically significantly smaller than the other two for many typical materials. Extending 3-axis milling of precut slabs to general arbitrarily-sized shapes requires decomposing them into bounded-height 3-axis millable parts, or
slices
, which can be individually milled and then assembled to form the target object. We present
DHFSlicer
, a novel decomposition method that satisfies the above constraints and significantly reduces both milling time and material waste compared to alternative approaches. We satisfy the fabrication constraints by partitioning target objects into
double height-field
(DHF) slices, which can be fabricated using two milling passes: the HF surface accessible from one side is milled first, the slice is then flipped using appropriate fixtures, and then the second, remaining, HF surface is milled.
DHFSlicer
uses an efficient coarse-to-fine decomposition process: It first partitions the inputs into maximally coarse blocks that satisfy a
local
DHF criterion with respect to per-block milling axes, and then cuts each block into well-sized DHF slices. It minimizes milling time and material waste by keeping the slice count small, and maximizing slice height. We validate our method by embedding it within an end-to-end DHF milling pipeline and fabricating objects from slabs of foam, wood, and MDF; demonstrate that using the obtained slices reduces milling time and material waste by 42% on average compared to existing automatic alternatives; and highlight the benefits of DHFSlicer via extensive ablation studies.
Deep relightable textures
Authors: Meka Abhimitra , Pandey Rohit , Häne Christian , Orts-Escolano Sergio , Barnum Peter , David-Son Philip , Erickson Daniel , Zhang Yinda , Taylor Jonathan , Bouaziz Sofien , Legendre Chloe , Ma Wan-Chun , Overbeck Ryan , Beeler Thabo , Debevec Paul , Izadi Shahram , Theobalt Christian , Rhemann Christoph , Fanello Sean
Published: November 2020

The increasing demand for 3D content in augmented and virtual reality has motivated the development of volumetric performance capture systemsnsuch as the Light Stage. Recent advances are pushing free viewpoint relightable videos of dynamic human performances closer to photorealistic quality. However, despite significant efforts, these sophisticated systems are limited by reconstruction and rendering algorithms which do not fully model complex 3D structures and higher order light transport effects such as global illumination and sub-surface scattering. In this paper, we propose a system that combines traditional geometric pipelines with a neural rendering scheme to generate photorealistic renderings of dynamic performances under desired viewpoint and lighting. Our system leverages deep neural networks that model the classical rendering process to learn implicit features that represent the view-dependent appearance of the subject independent of the geometry layout, allowing for generalization to unseen subject poses and even novel subject identity. Detailed experiments and comparisons demonstrate the efficacy and versatility of our method to generate high-quality results, significantly outperforming the existing state-of-the-art solutions.
Optimizing depth perception in virtual and augmented reality through gaze-contingent stereo rendering
Authors: Krajancich Brooke , Kellnhofer Petr , Wetzstein Gordon
Published: November 2020

Virtual and augmented reality (VR/AR) displays crucially rely on stereoscopic rendering to enable perceptually realistic user experiences. Yet, existing near-eye display systems ignore the gaze-dependent shift of the no-parallax point in the human eye. Here, we introduce a gaze-contingent stereo rendering technique that models this effect and conduct several user studies to validate its effectiveness. Our findings include experimental validation of the location of the no-parallax point, which we then use to demonstrate significant improvements of disparity and shape distortion in a VR setting, and consistent alignment of physical and digitally rendered objects across depths in optical see-through AR. Our work shows that gaze-contingent stereo rendering improves perceptual realism and depth perception of emerging wearable computing systems.
Sparse cholesky updates for interactive mesh parameterization
Authors: Herholz Philipp , Sorkine-Hornung Olga
Published: November 2020

We present a novel linear solver for interactive parameterization tasks. Our method is based on the observation that quasi-conformal parameterizations of a triangle mesh are largely determined by boundary conditions. These boundary conditions are typically constructed interactively by users, who have to take several artistic and geometric constraints into account while introducing cuts on the geometry. Commonly, the main computational burden in these methods is solving a linear system every time new boundary conditions are imposed. The core of our solver is a novel approach to efficiently update the Cholesky factorization of the linear system to reflect new boundary conditions, thereby enabling a seamless and interactive workflow even for large meshes consisting of several millions of vertices.