bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the Upper Atmosphere from Neutral and Electron Density Observations
Authors: Calabia Andres , Jin Shuanggen 
Published: September 2020

AbstractUpper-atmospheric processes under different space weather conditions are still not well understood, and the existing models are far away from the desired operational requirements due to the lack of in-situ measurements input. The ionospheric perturbation of electromagnetic signals affects the accuracy and reliability of Global Navigation Satellite Systems (GNSS), satellite communication infrastructures, and Earth observation techniques. Furthermore, the variable aerodynamic drag, due to variable thermospheric mass density, disturbs orbital tracking, collision analysis, and re-entry calculations of Low Earth Orbit (LEO) objects, including manned and unmanned artificial satellites. In this paper, we use the Principal Component Analysis (PCA) technique to study and compare the main driver-response relationships and spatial patterns of total electron content (TEC) estimates from 2003 to 2018, and total mass density (TMD) estimates at 475 km altitude from 2003 to 2015. Comparison of the first TEC and TMD PCA mode shows a very similar response to solar flux, but annual cycle shown by TEC is approximately one order of magnitude larger. A clear hemispheric asymmetry is shown in the global distribution of TMD, with higher values in the southern hemisphere than in the northern hemisphere. The hemispheric asymmetry is not visible in TEC. The persistent processes including a favorable solar wind input and particle precipitation over the southern magnetic dip may produce a higher thermospheric heating, which results in the hemispheric asymmetry in TMD.
Direct calculation of mutual information of distant regions
Authors: Shiba Noburo 
Published: September 2020

Abstract
We consider the (Rényi) mutual information, $$ {I}^{(n)}\left(A,B\right)={S}_A^{(n)}+{S}_B^{(n)}-{S}_{A\cup B}^{(n)} $$

I

n

A
B

=

S
A

n

+

S
B

n

−

S

A
∪
B

n

, of distant compact spatial regions A and B in the vacuum state of a free scalar field. The distance r between A and B is much greater than their sizes RA,B. It is known that $$ {I}^{(n)}\left(A,B\right)\sim {C}_{AB}^{(n)}{\left\langle 0\left|\phi (r)\phi (0)0\right|\right\rangle}^2 $$

I

n

A
B

∼

C
AB

n

0

ϕ

r

ϕ

0

0

2

. We obtain the direct expression of $$ {C}_{AB}^{(n)} $$

C
AB

n

for arbitrary regions A and B. We perform the analytical continuation of n and obtain the mutual information. The direct expression is useful for the numerical computation. By using the direct expression, we can compute directly I(A, B) without computing SA, SB and SA∪B respectively, so it reduces significantly the amount of computation.
nNNPDF2.0: quark flavor separation in nuclei from LHC data
Authors: Khalek Rabah Abdul , Ethier Jacob J. , Rojo Juan , van Weelden Gijs 
Published: September 2020

Abstract
We present a model-independent determination of the nuclear parton distribution functions (nPDFs) using machine learning methods and Monte Carlo techniques based on the NNPDF framework. The neutral-current deep-inelastic nuclear structure functions used in our previous analysis, nNNPDF1.0, are complemented by inclusive and charm-tagged cross-sections from charged-current scattering. Furthermore, we include all available measurements of W and Z leptonic rapidity distributions in proton-lead collisions from ATLAS and CMS at $$ \sqrt{s} $$

s

= 5.02 TeV and 8.16 TeV. The resulting nPDF determination, nNNPDF2.0, achieves a good description of all datasets. In addition to quantifying the nuclear modifications affecting individual quarks and antiquarks, we examine the implications for strangeness, assess the role that the momentum and valence sum rules play in nPDF extractions, and present predictions for representative phenomenological applications. Our results, made available via the LHAPDF library, highlight the potential of high-energy collider measurements to probe nuclear dynamics in a robust manner.
Topological correlators and surface defects from equivariant cohomology
Authors: Panerai Rodolfo , Pittelli Antonio , Polydorou Konstantina 
Published: September 2020

Abstract
We find a one-dimensional protected subsector of $$ \mathcal{N} $$
N
= 4 matter theories on a general class of three-dimensional manifolds. By means of equivariant localization we identify a dual quantum mechanics computing BPS correlators of the original model in three dimensions. Specifically, applying the Atiyah-Bott-Berline-Vergne formula to the original action demonstrates that this localizes on a one-dimensional action with support on the fixed-point submanifold of suitable isometries. We first show that our approach reproduces previous results obtained on S3. Then, we apply it to the novel case of S2× S1 and show that the theory localizes on two noninteracting quantum mechanics with disjoint support. We prove that the BPS operators of such models are naturally associated with a noncom- mutative star product, while their correlation functions are essentially topological. Finally, we couple the three-dimensional theory to general $$ \mathcal{N} $$
N
= (2, 2) surface defects and extend the localization computation to capture the full partition function and BPS correlators of the mixed-dimensional system.
Higher dimensional black hole scalarization
Authors: Astefanesei Dumitru , Herdeiro Carlos , Oliveira João , Radu Eugen 
Published: September 2020

Abstract
In the simplest scalar-tensor theories, wherein the scalar field is non-minimally coupled to the Ricci scalar, spontaneous scalarization of electrovacuum black holes (BHs) does not occur. This ceases to be true in higher dimensional spacetimes, d > 4. We consider the scalarization of the higher dimensional Reissner-Nordström BHs in scalar-tensor models and provide results on the zero modes for different d, together with an explicit construction of the scalarized BHs in d = 5, discussing some of their properties. We also observe that a conformal transformation into the Einstein frame maps this model into an Einstein-Maxwel- scalar model, wherein the non-minimal coupling occurs between the scalar field and the Maxwell invariant (rather than the Ricci scalar), thus relating the occurence of scalarization in the two models. Next, we consider the spontaneous scalarization of the Schwarzschild- Tangherlini BH in extended-scalar-tensor-Lovelock gravity in even dimensions. In these models, the scalar field is non-minimally coupled to the (d/2)th Euler density, in d spacetime dimensions. We construct explicitly examples in d = 6, 8, showing the properties of the four dimensional case are qualitatively generic, but with quantitative differences. We compare these higher d scalarized BHs with the hairy BHs in shift-symmetric Horndeski theory, for the same d, which we also construct.
Flavour violating effects of Yukawa running in SMEFT
Authors: Aebischer Jason , Kumar Jacky 
Published: September 2020

Abstract
We study Yukawa Renormalization Group (RG) running effects in the context of the Standard Model Effective Theory (SMEFT). The Yukawa running being flavour dependent leads to RG-induced off-diagonal entries, so that initially diagonal Yukawa matrices at the high scale have to be rediagonalized at the electroweak (EW) scale. Performing such flavour rotations can lead to flavour violating operators which differ from the ones obtained through SMEFT RG evolution. We show, that these flavour rotations can have a large impact on low-energy phenomenology. In order to demonstrate this effect, we com- pare the two sources of flavour violation numerically as well as analytically and study their influence on several examples of down-type flavour transitions. For this purpose we con- sider $$ {B}_s-{\overline{B}}_s $$

B
s

−

B
¯

s

mixing, b → sγ, b → sℓℓ as well as electroweak precision observables. We show that the rotation effect can be comparable or even larger than the contribution from pure RGE evolution of the Wilson coefficients.
A High-Frequency Homogenization Approach Near the Dirac Points in Bubbly Honeycomb Crystals
Authors: Ammari Habib , Hiltunen Erik Orvehed , Yu Sanghyeon 
Published: September 2020

AbstractIn (Ammari et al. in SIAM J Math Anal. arXiv:1811.03905), the existence of a Dirac dispersion cone in a bubbly honeycomb phononic crystal comprised of bubbles of arbitrary shape is shown. The aim of this paper is to prove that, near the Dirac points, the Bloch eigenfunctions is the sum of two eigenmodes. Each eigenmode can be decomposed into two components: one which is slowly varying and satisfies a homogenized equation, while the other is periodic across each elementary crystal cell and is highly oscillating. The slowly oscillating components of the eigenmodes satisfy a system of Dirac equations. Our results in this paper prove for the first time a near-zero effective refractive index near the Dirac points for the plane-wave envelopes of the Bloch eigenfunctions in a sub-wavelength metamaterial. They are illustrated by a variety of numerical examples. We also compare and contrast the behaviour of the Bloch eigenfunctions in the honeycomb crystal with that of their counterparts in a bubbly square crystal, near the corner of the Brillouin zone, where the maximum of the first Bloch eigenvalue is attained.
Couplings via Comparison Principle and Exponential Ergodicity of SPDEs in the Hypoelliptic Setting
Authors: Butkovsky Oleg , Scheutzow Michael 
Published: September 2020

AbstractWe develop a general framework for studying ergodicity of order-preserving Markov semigroups. We establish natural and in a certain sense optimal conditions for existence and uniqueness of the invariant measure and exponential convergence of transition probabilities of an order-preserving Markov process. As an application, we show exponential ergodicity and exponentially fast synchronization-by-noise of the stochastic reaction–diffusion equation in the hypoelliptic setting. This refines and complements corresponding results of Hairer and Mattingly (Electron J Probab 16:658–738, 2011).
Adiabatic Invariants for the FPUT and Toda Chain in the Thermodynamic Limit
Authors: Grava T. , Maspero A. , Mazzuca G. , Ponno A. 
Published: September 2020

AbstractWe consider the Fermi–Pasta–Ulam–Tsingou (FPUT) chain composed by $$N \gg 1$$

N
≫
1

particles and periodic boundary conditions, and endow the phase space with the Gibbs measure at small temperature $$\beta ^{-1}$$

β

-
1

. Given a fixed $${1\le m \ll N}$$

1
≤
m
≪
N

, we prove that the first m integrals of motion of the periodic Toda chain are adiabatic invariants of FPUT (namely they are approximately constant along the Hamiltonian flow of the FPUT) for times of order $$\beta $$
β
, for initial data in a set of large measure. We also prove that special linear combinations of the harmonic energies are adiabatic invariants of the FPUT on the same time scale, whereas they become adiabatic invariants for all times for the Toda dynamics.
Influence of action video gaming on spatial representation in the haptic modality
Authors: Van Mier Hanneke I. , Jiao Hui 
Published: September 2020

AbstractSpatial representation in the haptic domain has been shown to be prone to systematic errors. When participants are asked to make two bars haptically parallel, their performance deviates from what would be veridically parallel. This is hypothesized to be caused by the bias of the egocentric reference frame. Stimulating the use of an allocentric reference frame has previously been shown to improve performance in haptic parallelity matching. The aim of the current study was to investigate the influence of action video game experience on parallelity performance. We hypothesized that participants who extensively play action video games with a so-called ‘bird’s-eye view’ are likely to process spatial information more allocentrically, resulting in better performance in haptic parallelity matching. This was tested in two groups of male participants, 10 participants with extensive action video gaming experience (AVGPs) and 10 participants without or hardly any action video gaming experience (NAVGPs). Additionally, the effect of visual–haptic practice on haptic parallelity performance was tested. In the haptic blocks, blindfolded participants had to feel the orientation of a reference bar with their non-dominant hand and had to match this orientation on a test bar with their dominant hand. In subsequent visual–haptic blocks, they had full view of the set-up and visually paralleled both bars. As hypothesized, AVGPs performed significantly better in haptic blocks than NAVGPs. Visual–haptic practice resulted in significantly better performance in subsequent haptic blocks in both groups. These results suggest that playing action video games might enhance haptic spatial representation, although a causative relationship still needs to be established.
Validation of an in vivo porcine simulation model of pedicled latissimus dorsi myocutaneous flap elevation
Authors: Hamada Maha Wagdy , Pafitanis Giorgios , Nistor Alex , Kim Youn Hwan , Myers Simon , Ghanem Ali 
Published: September 2020

Abstract
Background
In vivo and ex vivo simulation training workshops can contribute to surgical skill acquisition but require validation before becoming incorporated within curricula. Ideally, that validation should include the following: face, content, construct, concurrent, and predictive validity.

Methods
During two in vivo porcine surgical training workshops, 27 participants completed questionnaires relating to face and content validity of porcine in vivo flap elevation. Six participants’ performances raising a pedicled myocutaneous latissimus dorsi (LD) flap in the pig (2 experts and 4 trainees) were sequentially and objectively assessed for construct validity with hand motion analysis (HMA), a performance checklist, a blinded randomized procedure-specific rating scale of standardized video recordings, and flap viability by fluorescence imaging.

Results
Face and content validity were demonstrated straightforwardly. Construct validity was demonstrated for average procedure time by HMA between trainees and experts (p = 0.036). Skill acquisition was demonstrated by trainees’ HMA average number of hand movements (p = 0.046) and fluorescence flap viability (p = 0.034).

Conclusion
Face and content validity for in vivo porcine flap elevation simulation training were established. Construct validity was established for an in vivo porcine latissimus dorsi flap elevation simulation specifically. Predictive validity will prove more challenging to establish.
Level of evidence: Not ratable .
Causes of acromion and scapular spine fractures following reverse shoulder arthroplasty: a retrospective analysis and literature review
Authors: Nyffeler Richard W. , Altioklar Bartu , Bissig Philipp 
Published: September 2020

Abstract
Purpose
Fractures of the acromion and the scapular spine are serious complications after reverse total shoulder arthroplasty. They concern about 4 to 5% of the patients and always result in a significant deterioration of shoulder function. Different causes have been taken into consideration, particularly stress or fatigue fractures. The purpose of the present study was to analyse our own cases and to discuss the causes reported in the literature.

Methods
We reviewed our shoulder arthroplasty registry and the consultation reports of the last ten years. The charts and radiographs of all patients who had a post-operative fracture of the acromion or the scapular spine were carefully examined and the results were compared with those of an age- and gender-matched control group.

Results
Twelve patients with an average age of 79 years sustained a fracture of the acromion (n = 6) or the scapular spine (n = 6). The time interval between the operation and the fracture averaged 26 months and ranged from three weeks to 70 months. Eight patients (67%) had a trauma. Seven of them reported a fall on the corresponding shoulder and one a heavy blow on the acromion. The four non-traumatic fractures were attributed to poor bone quality. All 12 patients had immediate pain and difficulty to actively elevate the affected arm. The time interval between the fracture and its diagnosis averaged ten weeks (0 to 10 months). At final follow-up, all patients could reach their face and refused further surgery. Two patients rated their result as good, six as acceptable and four as poor.

Conclusions
Our study cannot support the hypothesis that most acromion and scapular spine fractures after RSA are the result of increased tension in the deltoid or stress fractures. In our series, the majority of the fractures were related to a fall. Implantation of a reverse prosthesis exposes the acromion and makes it more vulnerable to direct trauma. Non-traumatic fractures were associated with poor bone quality.
Donor Site Morbidity of Patients Receiving Vertical Rectus Abdominis Myocutaneous Flap for Perineal, Vaginal or Inguinal Reconstruction
Authors: Schellerer Vera S. , Bartholomé Lenka , Langheinrich Melanie C. , Grützmann Robert , Horch Raymund E. , Merkel Susanne , Weber Klaus 
Published: September 2020

AbstractBackgroundManagement of donor site closure after harvesting a vertical rectus abdominis myocutaneous (VRAM) flap is discussed heterogeneously in the literature. We aim to analyze the postoperative complications of the donor site depending on the closure technique.MethodsDuring a 12‐year period (2003–2015), 192 patients in our department received transpelvic VRAM flap reconstruction. Prospectively collected data were analyzed retrospectively.Results182 patients received a VRAM flap reconstruction for malignant, 10 patients for benign disease. The median age of patients was 62 years. 117 patients (61%) received a reconstruction of donor site by Vypro® mesh, 46 patients (24%) by Vicryl® mesh, 23 patients (12%) by direct closure and 6 patients (3%) by combination of different meshes. 32 patients (17%) developed in total 34 postoperative complications at the donor site. 22 complications (11%) were treated conservatively, 12 (6%) surgically. 17 patients (9%) developed incisional hernia during follow‐up, with highest incidence in the Vicryl® group (n = 8; 17%) and lowest in the Vypro® group (n = 7; 6%). Postoperative parastomal hernias were found in 30 patients (16%) including three patients with simultaneous hernia around an urostomy and a colostomy. The highest incidence of parastomal hernia was found in patients receiving primary closure of the donor site (n = 6; 26%), the lowest incidence in the Vypro® group (n = 16; 14%).ConclusionThe use of Vypro® mesh for donor site closure appears to be associated with a low postoperative incidence of complications and can therefore be recommended as a preferred technique.
In‐Hospital Postoperative Mortality Rates for Selected Procedures in Tanzania's Lake Zone
Authors: Wurdeman Taylor , Strader Christopher , Alidina Shehnaz , Barash David , Citron Isabelle , Kapologwe Ntuli , Maina Erastus , Massaga Fabian , Mazhiqi Adelina , Meara John G. , Menon Gopal , Reynolds Cheri , Sydlowski Meaghan , Varallo John , Maongezi Sarah , Ulisubisya Mpoki 
Published: September 2020

AbstractBackgroundPostoperative mortality rate is one of six surgical indicators identified by the Lancet Commission on Global Surgery for monitoring access to high‐quality surgical care. The primary aim of this study was to measure the postoperative mortality rate in Tanzania's Lake Zone to provide a baseline for surgical strengthening efforts. The secondary aim was to measure the effect of Safe Surgery 2020, a multi‐component intervention to improve surgical quality, on postoperative mortality after 10 months.MethodsWe prospectively collected data on postoperative mortality from 20 health centers, district hospitals, and regional hospitals in Tanzania's Lake Zone over two time periods: pre‐intervention (February to April 2018) and post‐intervention (March to May 2019). We analyzed postoperative mortality rates by procedure type. We used logistic regression to determine the impact of Safe Surgery 2020 on postoperative mortality.ResultsThe overall average in‐hospital non‐obstetric postoperative mortality rate for all surgery procedures was 2.62%. The postoperative mortality rates for laparotomy were 3.92% and for cesarean delivery was 0.24%. Logistic regression demonstrated no difference in the postoperative mortality rate after the Safe Surgery 2020 intervention.ConclusionsOur results inform national surgical planning in Tanzania by providing a sub‐national baseline estimate of postoperative mortality rates for multiple surgical procedures and serve as a basis from which to measure the impact of future surgical quality interventions. Our study showed no improvement in postoperative mortality after implementation of Safe Surgery 2020, possibly due to low power to detect change.
#Covid4Rheum: an analytical twitter study in the time of the COVID-19 pandemic
Authors: Ruffer Nikolas , Knitza Johannes , Krusche Martin 
Published: September 2020

AbstractSocial media services, such as Twitter, offer great potential for a better understanding of rheumatic and musculoskeletal disorders (RMDs) and improved care in the field of rheumatology. This study examined the content and stakeholders associated with the Twitter hashtag #Covid4Rheum during the COVID-19 pandemic. The content analysis shows that Twitter connects stakeholders of the rheumatology community on a global level, reaching millions of users. Specifically, the use of hashtags on Twitter assists digital crowdsourcing projects and scientific collaboration, as exemplified by the COVID-19 Global Rheumatology Alliance registry. Moreover, Twitter facilitates the distribution of scientific content, such as guidelines or publications. Finally, digital data mining enables the identification of hot topics within the field of rheumatology.
Time interval between (chemo)radiotherapy and subsequent laryngectomy is not prognostic for post operative complications and survival
Authors: Pézier Thomas F. , Rijken Johannes A. , Tijink Bernard M. , Braunius W. Weibel , de Bree Remco 
Published: September 2020

Abstract
Purpose
Pharyngocutaneous fistula (PCF) formation and swallowing difficulties are common and troublesome complications following total laryngectomy (TL). Prior (chemo)radiotherapy ((C)RT) is thought to be a risk factor for these complications, but there is conflicting evidence as to whether the time interval between (C)RT and TL is important. The impact of time interval on these complications and also its impact on overall survival are investigated.

Methods
This is a retrospective case note review of all patients undergoing TL at the University Medical Center, Utrecht, The Netherlands over the 10-year period from January 2008 to December 2017. The cohort was split into those who underwent TL within a year of finishing (C)RT and those longer than 1 year.

Results
One hundred and twenty-six patients (108 males, 18 females), with a mean age of 66 underwent total laryngectomy after prior (C)RT in the study period. Overall 5-year survival was 35% with a median follow-up of 30 months. Fifty-four patients underwent laryngectomy within a year of their (C)RT versus 72 patients who had a time interval of more than one year. No differences in PCF rate, risk of dilatation or overall survival could be found between the two groups.

Conclusions
In this modern cohort, time interval between (C)RT and surgery did not impact PCF rate, risk of dilatation or overall survival.