bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear relations for Laurent polynomials and lattice equations
Authors: Hone Andrew N W , Pallister Joe
Published: October 2020

A recurrence relation is said to have the Laurent property if all of its iterates are Laurent polynomials in the initial values with integer coefficients. Recurrences with this property appear in diverse areas of mathematics and physics, ranging from Lie theory and supersymmetric gauge theories to Teichmüller theory and dimer models. In many cases where such recurrences appear, there is a common structural thread running between these different areas, in the form of Fomin and Zelevinsky’s theory of cluster algebras. Laurent phenomenon algebras, as defined by Lam and Pylyavskyy, are an extension of cluster algebras, and share with them the feature that all the generators of the algebra are Laurent polynomials in any initial set of generators (seed). Here we consider a family of nonlinear recurrences with the Laurent property, referred to as ‘Little Pi’, which was derived by Almanet alvia a construction of periodic seeds in Laurent phenomenon algebras, and generalizes the Heideman–Hogan family of recurrences. Each member of the family is shown to be linearizable, in the sense that the iterates satisfy linear recurrence relations with constant coefficients. We derive the latter from linear relations with periodic coefficients, which were found recently by Kamiyaet alfrom travelling wave reductions of a linearizable lattice equation on a six-point stencil. By making use of the periodic coefficients, we further show that the birational maps corresponding to the Little Pi family are maximally superintegrable. We also introduce another linearizable lattice equation on the same six-point stencil, and present the corresponding linearization for its travelling wave reductions. Finally, for both of the six-point lattice equations considered, we use the formalism of van der Kamp to construct a broad class of initial value problems with the Laurent property.
Optomechanical cooling by STIRAP-assisted energy transfer: an alternative route towards the mechanical ground state
Authors: Sarma Bijita , Busch Thomas , Twamley Jason
Published: October 2020

Standard optomechanical cooling methods ideally require weak coupling and cavity damping rates which enable the motional sidebands to be well resolved. If the coupling is too large then sideband-resolved cooling is unstable or the rotating wave approximation can become invalid. In this work we describe a protocol to cool a mechanical resonator coupled to a driven optical mode in an optomechanical cavity, which is also coupled to an optical mode in another auxiliary optical cavity, and both the cavities are frequency-modulated. We show that by modulating the amplitude of the drive as well, one can execute a type of STIRAP transfer of occupation from the mechanical mode to the lossy auxiliary optical mode which results in cooling of the mechanical mode. We show how this protocol can outperform normal optomechanical sideband cooling in various regimes such as the strong coupling and the unresolved sideband limit.
Numerical simulation of the coupled viscous Burgers equation using the Hermite formula and cubic B-spline basis functions
Authors: Abdullah Muhammad , Yaseen Muhammad , de la Sen Manuel
Published: October 2020

A numerical procedure dependent on the cubic B-spline and the Hermite formula is developed for the coupled viscous Burgers’ equation (CVBE). The method uses a combination of the Hermite formula and the cubic B-spline for discretization of the space dimension while the time dimension is approximated using the typical finite differences. A piecewise continuous sufficiently smooth function is obtained as a solution which allows to approximate solution at any location in the domain of interest. The scheme is tested for stability analysis and is proved to be unconditionally stable. Numerical experiments and comparison of outcomes reveal that the suggested scheme comes up with better accuracy and is extremely productive.
On the role of the hydrogen concentration in the L-H transition power threshold in EAST
Authors: Shao L.M. , Xu G.S. , Yu Y.W. , Zhang L. , Chen L. , Chen Y.J. , Duan Y.M. , Gao W. , He L. , Hu J.S. , Li Y.Y. , Qian J.P. , Wang Y.M. , Wu X.Q. , Xu W. , Yan N. , Zhou T.F. , Zuo G.Z.
Published: October 2020

A decrease in the L-H transition power threshold

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L-H

under the lithium wall conditioning has been observed since 2010 in EAST. The physical mechanism responsible for the reduced

P

L-H

is found to be related to three phases of wall recycling as determined by the accumulation of lithium in the vessel. In phase I (a few rounds of wall conditioning) the wall recycling is low, while no clear variation of L-H transition power threshold is observed. In phase II (after another few rounds of wall conditioning) a clear increase in the wall recycling is observed, leading to decreased L-H transition power threshold. In phase III the wall recycling is higher and the hydrogen concentration

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is lower compared to phases I and II. In this third phase the L-H transition power threshold is mainly reduced by the decreased

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. During phase III of the wall recycling, the quantitative relationship between the hydrogen content and normalized L-H transition power threshold

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Interregional Transfers for Pandemic Surges
Authors: Michelson Kenneth A , Rees Chris A , Sarathy Jayshree , VonAchen Paige , Wornow Michael , Monuteaux Michael C , Neuman Mark I
Published: October 2020

Background

Hospital inpatient and intensive care unit (ICU) bed shortfalls may arise due to regional surges in volume. We sought to determine how interregional transfers could alleviate bed shortfalls during a pandemic.

Methods

We used estimates of past and projected inpatient and ICU cases of coronavirus disease 2019 (COVID-19) from 4 February 2020 to 1 October 2020. For regions with bed shortfalls (where the number of patients exceeded bed capacity), transfers to the nearest region with unused beds were simulated using an algorithm that minimized total interregional transfer distances across the United States. Model scenarios used a range of predicted COVID-19 volumes (lower, mean, and upper bounds) and non–COVID-19 volumes (20%, 50%, or 80% of baseline hospital volumes). Scenarios were created for each day of data, and worst-case scenarios were created treating all regions’ peak volumes as simultaneous. Mean per-patient transfer distances were calculated by scenario.

Results

For the worst-case scenarios, national bed shortfalls ranged from 669 to 58 562 inpatient beds and 3208 to 31 190 ICU beds, depending on model volume parameters. Mean transfer distances to alleviate daily bed shortfalls ranged from 23 to 352 miles for inpatient and 28 to 423 miles for ICU patients, depending on volume. Under all worst-case scenarios except the highest-volume ICU scenario, interregional transfers could fully resolve bed shortfalls. To do so, mean transfer distances would be 24 to 405 miles for inpatients and 73 to 476 miles for ICU patients.

Conclusions

Interregional transfers could mitigate regional bed shortfalls during pandemic hospital surges.
Usefulness of left atrial strain for predicting incident atrial fibrillation and ischaemic stroke in the general population
Authors: Alhakak Alia Saed , Biering-Sørensen Sofie Reumert , Møgelvang Rasmus , Modin Daniel , Jensen Gorm Boje , Schnohr Peter , Iversen Allan Zeeberg , Svendsen Jesper Hastrup , Jespersen Thomas , Gislason Gunnar , Biering-Sørensen Tor
Published: October 2020

Aims

Left atrial enlargement predicts incident atrial fibrillation (AF). However, the prognostic value of peak atrial longitudinal strain (PALS) for predicting incident AF in participants from the general population is currently unknown. Our aim was to investigate if PALS can be used to predict AF and ischaemic stroke in the general population.

Methods and results

A total of 400 participants from the general population underwent a health examination, including two-dimensional speckle tracking echocardiography of the left atrium. The primary endpoint was incident AF at follow-up. All participants with known AF and prior stroke at baseline were excluded (n = 54). The secondary endpoint consisted of the composite of AF and ischaemic stroke. During a median follow-up of 16 years, 36 participants (9%) were diagnosed with incident AF and 30 (7%) experienced an ischaemic stroke, resulting in 66 (16%) experiencing the composite outcome. PALS was a univariable predictor of AF [per 5% decrease: hazard ratio (HR) 1.42; 95% confidence interval (CI) (1.19–1.69), P < 0.001]. However, the prognostic value of PALS was modified by age (P = 0.002 for interaction). After multivariable adjustment PALS predicted AF in participants aged <65 years [per 5% decrease: HR 1.46; 95% CI (1.06–2.02), P = 0.021]. In contrast, PALS did not predict AF in participants aged ≥65 years after multivariable adjustment [per 5% decrease: HR 1.05; 95% CI (0.81–1.35), P = 0.72]. PALS also predicted the secondary endpoint in participants aged <65 years and the association remained significant after multivariable adjustment.

Conclusion

In a low-risk general population, PALS provides novel prognostic information on the long-term risk of AF and ischaemic stroke in participants aged <65 years.
Disease-associated GRIN protein truncating variants trigger NMDA receptor loss-of-function
Authors: Santos-Gómez Ana , Miguez-Cabello Federico , García-Recio Adrián , Locubiche-Serra Sílvia , García-Díaz Roberto , Soto-Insuga Víctor , Guerrero-López Rosa , Juliá-Palacios Natalia , Ciruela Francisco , García-Cazorla Àngels , Soto David , Olivella Mireia , Altafaj Xavier
Published: October 2020

De novo GRIN variants, encoding for the ionotropic glutamate NMDA receptor subunits, have been recently associated with GRIN-related disorders, a group of rare paediatric encephalopathies. Current investigational and clinical efforts are focused to functionally stratify GRIN variants, towards precision therapies of this primary disturbance of glutamatergic transmission that affects neuronal function and brain. In the present study, we aimed to comprehensively delineate the functional outcomes and clinical phenotypes of GRIN protein truncating variants (PTVs)—accounting for ~20% of disease-associated GRIN variants—hypothetically provoking NMDAR hypofunctionality. To tackle this question, we created a comprehensive GRIN PTVs variants database compiling a cohort of nine individuals harbouring GRIN PTVs, together with previously identified variants, to build-up an extensive GRIN PTVs repertoire composed of 293 unique variants. Genotype–phenotype correlation studies were conducted, followed by cell-based assays of selected paradigmatic GRIN PTVs and their functional annotation. Genetic and clinical phenotypes meta-analysis revealed that heterozygous GRIN1, GRIN2C, GRIN2D, GRIN3A and GRIN3B PTVs are non-pathogenic. In contrast, heterozygous GRIN2A and GRIN2B PTVs are associated with specific neurological clinical phenotypes in a subunit- and domain-dependent manner. Mechanistically, cell-based assays showed that paradigmatic pathogenic GRIN2A and GRIN2B PTVs result on a decrease of NMDAR surface expression and NMDAR-mediated currents, ultimately leading to NMDAR functional haploinsufficiency. Overall, these findings contribute to delineate GRIN PTVs genotype–phenotype association and GRIN variants stratification. Functional studies showed that GRIN2A and GRIN2B pathogenic PTVs trigger NMDAR hypofunctionality, and thus accelerate therapeutic decisions for this neurodevelopmental condition.
AG Hogan advises CJEU to rule that disclosure of evidence in court proceedings is not a communication to the public
Authors: Malovic Nedim
Published: October 2020

Opinion of Advocate General Hogan in Case C-637/19 BY v CX, EU:C:2020:650, 3 September 2020

In his Opinion on 3 September 2020, Advocate General (AG) Hogan advised the Court of Justice of the European Union (CJEU) to rule that the electronic transmission by a party to proceedings of protected materials as evidence to a court does neither constitute a communication nor a distribution to the public under, respectively, Articles 3(1) and 4(1) of Directive 2001/29 (the InfoSoc Directive).
Telescope performance real-time monitoring based on machine learning
Authors: Hu Tian Z , Zhang Yong , Cui Xiang Q , Zhang Qing Y , Li Ye P , Cao Zi H , Pan Xiu S , Fu Ying
Published: October 2020

In astronomy, the demand for high-resolution imaging and high-efficiency observation requires telescopes that are maintained at peak performance. To improve telescope performance, it is useful to conduct real-time monitoring of the telescope status and detailed recordings of the operational data of the telescope. In this paper, we provide a method based on machine learning to monitor the telescope performance in real-time. First, we use picture features and the random forest algorithm to select normal pictures captured by the acquisition camera or science camera. Next, we cut out the source image of the picture and use convolutional neural networks to recognize star shapes. Finally, we monitor the telescope performance based on the relationship between the source image shape and telescope performance. Through this method, we achieve high-performance real-time monitoring with the Large Sky Area Multi-Object Fibre Spectroscopic Telescope, including guiding system performance, focal surface defocus, submirror performance, and active optics system performance. The ultimate performance detection accuracy can reach up to 96.7 per cent.
Characterizing the Gaia radial velocity sample selection function in its native photometry
Authors: Rybizki Jan , Rix Hans-Walter , Demleitner Markus , Bailer-Jones Coryn A L , Cooper William J
Published: October 2020

The Gaia Data Release 2 (DR2) radial velocity sample (GDR2RVS), which provides six-dimensional phase-space information on 7.2 million stars, is of great value for inferring properties of the Milky Way. Yet a quantitative and accurate modelling of this sample is hindered without knowledge and inclusion of a well-characterized selection function. Here we derive the selection function through estimates of the internal completeness, i.e. the ratio of GDR2RVS sources compared to all Gaia DR2 sources (GDR2all). We show that this selection function or ‘completeness’ depends on basic observables, in particular the apparent magnitude GRVS and colour G − GRP, but also on the surrounding source density and on sky position, where the completeness exhibits distinct small-scale structure. We identify a region of magnitude and colour that has high completeness, providing an approximate but simple way of implementing the selection function. For a more rigorous and detailed description we provide python code to query our selection function, as well as tools and adql queries that produce custom selection functions with additional quality cuts.
Chemical diversity among A–B stars with low rotational velocities: non-LTE abundance analysis
Authors: Mashonkina L , Ryabchikova T , Alexeeva S , Sitnova T , Zatsarinny O
Published: October 2020

We present accurate element abundance patterns based on the non-local thermodynamic equilibrium (non-LTE, NLTE) line formation for 14 chemical elements from He to Nd for a sample of nine A9 to B3-type stars with well-determined atmospheric parameters and low rotational velocities. We constructed new model atom of Zr ii–iii and updated model atoms for Sr ii and Ba ii by implementing the photoionization cross-sections from calculations with the Dirac B-spline R-matrix method. The NLTE abundances of He to Fe in the stars HD 17081, HD 32115, HD 160762, and HD 209459 are found to be consistent with the solar abundances, and HD 73666 being a Blue Straggler does not reveal deviations from chemical composition of the Praesepe cluster. Three of these stars with an effective temperature of lower than 10 500 K have supersolar abundances of Sr, Zr, Ba, and Nd, and our results suggest the presence of a positive correlation between stellar effective temperature and abundance. For each star, enhancement of Ba is higher than that for any other heavy element. We propose that the solar Ba abundance is not representative of the galactic Ba abundance at modern epoch. The status of HD 145788 was not clarified: This star has solar abundances of C to Si and enhancements of Sr to Ba similar to that for superficially normal stars of similar temperature, while Ca, Ti, and Fe are overabundant. The NLTE abundances of Vega support its status of a mild λ Bootis star.
Synthetic line and continuum observations of simulated turbulent clouds: the apparent widths of filaments
Authors: Priestley F D , Whitworth A P
Published: October 2020

Filamentary structures are ubiquitous in observations of real molecular clouds and also in simulations of turbulent, self-gravitating gas. However, making comparisons between observations and simulations is complicated by the difficulty of estimating volume densities observationally. Here, we have post-processed hydrodynamical simulations of a turbulent isothermal molecular cloud, using a full time-dependent chemical network. We have then run radiative transfer models to obtain synthetic line and continuum intensities that can be compared directly with those observed. We find that filaments have a characteristic width of ${\sim }0.1 \, {\rm pc}$, both on maps of their true surface density and on maps of their $850\, {\rm \mu m}$ dust continuum emission in agreement with previous work. On maps of line emission from CO isotopologues, the apparent widths of filaments are typically several times larger because the line intensities are poorly correlated with the surface density. On maps of line emission from dense gas tracers such as N2H+ and HCN, the apparent widths of filaments are ${\la}0.1\, {\rm pc}$. Thus, current observations of molecular-line emission are compatible with the universal $0.1 \, {\rm pc}$ filament width inferred from Herschel observations, provided proper account is taken of abundance, optical depth, and excitation considerations. We find evidence for ${\sim}0.4 \, {\rm km \, s^{-1}}$ radial velocity differences across filaments. These radial velocity differences might be a useful indicator of the mechanism by which a filament has formed or is forming, for example the turbulent cloud scenario modelled here, as against other mechanisms such as cloud–cloud collisions.
A ‘big data’ approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species
Authors: Graf Daniel L , Cummings Kevin S
Published: October 2020

The objective of this review is to update our previously published checklist of Recent freshwater mussel species and genera (Graf & Cummings, 2007, J. Molluscan Stud.: 291–314) to reflect the new data and research findings that have accumulated over the last decade. The MUSSEL Project Database was developed to synthesize the available taxonomic nomenclature, species ranges and published taxonomic hypotheses on genus–species combinations and synonymy. We have found 4,988 available species-group level nominal species representing 958 valid species in 192 genera worldwide, an increase of 118 species since 2007. The current patterns of species richness are discussed with regard to both taxonomy and geography, as is the general flux in the number of species recognized over time. A checklist is provided herein, with a bibliography to key faunistic and taxonomic references. The full dataset is maintained and updated on the MUSSEL Project Web Site (http://mussel-project.net/).
A novel assay provides insight into tRNAPhe retrograde nuclear import and re-export inS. cerevisiae
Authors: Nostramo Regina T , Hopper Anita K
Published: October 2020

In eukaryotes, tRNAs are transcribed in the nucleus and subsequently exported to the cytoplasm where they serve as essential adaptor molecules in translation. However, tRNAs can be returned to the nucleus by the evolutionarily conserved process called tRNA retrograde nuclear import, before relocalization back to the cytoplasm via a nuclear re-export step. Several important functions of these latter two trafficking events have been identified, yet the pathways are largely unknown. Therefore, we developed an assay in Saccharomyces cerevisiae to identify proteins mediating tRNA retrograde nuclear import and re-export using the unique wybutosine modification of mature tRNAPhe. Our hydrochloric acid/aniline assay revealed that the karyopherin Mtr10 mediates retrograde import of tRNAPhe, constitutively and in response to amino acid deprivation, whereas the Hsp70 protein Ssa2 mediates import specifically in the latter. Furthermore, tRNAPhe is re-exported by Crm1 and Mex67, but not by the canonical tRNA exporters Los1 or Msn5. These findings indicate that the re-export process occurs in a tRNA family-specific manner. Together, this assay provides insights into the pathways for tRNAPhe retrograde import and re-export and is a tool that can be used on a genome-wide level to identify additional gene products involved in these tRNA trafficking events.
MASI: microbiota—active substance interactions database
Authors: Zeng Xian , Yang Xue , Fan Jiajun , Tan Ying , Ju Lingyi , Shen Wanxiang , Wang Yali , Wang Xinghao , Chen Weiping , Ju Dianwen , Chen Yu Zong
Published: October 2020

Xenobiotic and host active substances interact with gut microbiota to influence human health and therapeutics. Dietary, pharmaceutical, herbal and environmental substances are modified by microbiota with altered bioavailabilities, bioactivities and toxic effects. Xenobiotics also affect microbiota with health implications. Knowledge of these microbiota and active substance interactions is important for understanding microbiota-regulated functions and therapeutics. Established microbiota databases provide useful information about the microbiota-disease associations, diet and drug interventions, and microbiota modulation of drugs. However, there is insufficient information on the active substances modified by microbiota and the abundance of gut bacteria in humans. Only ∼7% drugs are covered by the established databases. To complement these databases, we developed MASI, Microbiota—Active Substance Interactions database, for providing the information about the microbiota alteration of various substances, substance alteration of microbiota, and the abundance of gut bacteria in humans. These include 1,051 pharmaceutical, 103 dietary, 119 herbal, 46 probiotic, 142 environmental substances interacting with 806 microbiota species linked to 56 diseases and 784 microbiota–disease associations. MASI covers 11 215 bacteria-pharmaceutical, 914 bacteria-herbal, 309 bacteria-dietary, 753 bacteria-environmental substance interactions and the abundance profiles of 259 bacteria species in 3465 patients and 5334 healthy individuals. MASI is freely accessible at http://www.aiddlab.com/MASI.
Directed co-evolution of interacting protein–peptide pairs by compartmentalized two-hybrid replication (C2HR)
Authors: Siau Jia Wei , Nonis Samuel , Chee Sharon , Koh Li Quan , Ferrer Fernando J , Brown Christopher J , Ghadessy Farid J
Published: October 2020

Directed evolution methodologies benefit from read-outs quantitatively linking genotype to phenotype. We therefore devised a method that couples protein–peptide interactions to the dynamic read-out provided by an engineered DNA polymerase. Fusion of a processivity clamp protein to a thermostable nucleic acid polymerase enables polymerase activity and DNA amplification in otherwise prohibitive high-salt buffers. Here, we recapitulate this phenotype by indirectly coupling the Sso7d processivity clamp to Taq DNA polymerase via respective fusion to a high affinity and thermostable interacting protein–peptide pair. Escherichia coli cells co-expressing protein–peptide pairs can directly be used in polymerase chain reactions to determine relative interaction strengths by the measurement of amplicon yields. Conditional polymerase activity is further used to link genotype to phenotype of interacting protein–peptide pairs co-expressed in E. coli using the compartmentalized self-replication directed evolution platform. We validate this approach, termed compartmentalized two-hybrid replication, by selecting for high-affinity peptides that bind two model protein partners: SpyCatcher and the large fragment of NanoLuc luciferase. We further demonstrate directed co-evolution by randomizing both protein and peptide components of the SpyCatcher–SpyTag pair and co-selecting for functionally interacting variants.
Clinically relevant updates of the HbVar database of human hemoglobin variants and thalassemia mutations
Authors: Giardine Belinda M , Joly Philippe , Pissard Serge , Wajcman Henri , K. Chui David H , Hardison Ross C , Patrinos George P
Published: October 2020

HbVar (http://globin.bx.psu.edu/hbvar) is a widely-used locus-specific database (LSDB) launched 20 years ago by a multi-center academic effort to provide timely information on the numerous genomic variants leading to hemoglobin variants and all types of thalassemia and hemoglobinopathies. Here, we report several advances for the database. We made clinically relevant updates of HbVar, implemented as additional querying options in the HbVar query page, allowing the user to explore the clinical phenotype of compound heterozygous patients. We also made significant improvements to the HbVar front page, making comparative data querying, analysis and output more user-friendly. We continued to expand and enrich the regular data content, involving 1820 variants, 230 of which are new entries. We also increased the querying potential and expanded the usefulness of HbVar database in the clinical setting. These several additions, expansions and updates should improve the utility of HbVar both for the globin research community and in a clinical setting.
Constitutional Conventions and the Judiciary
Authors: Stephenson Scott
Published: October 2020

Analyses of constitutional conventions tend not to include those conventions that concern relations between the judiciary and other arms of government. The focus is generally on the conventions concerning the monarch, executive and legislature. This article argues that a study of the constitutional conventions relating to the judiciary reveals three insights about the nature of constitutional conventions and the nature of the judiciary. First, significant aspects of the judiciary’s authority, independence and impartiality are often secured by means of constitutional convention. Second, these conventions help understand the simultaneous strength and fragility of the judiciary’s constitutional position. Third, they highlight that, contrary to suggestions in the literature on democratic decay, it is not always problematic for constitutional conventions to be modified or even destroyed. To illustrate these insights, the article compares the executive’s duty to defend the judiciary from public attack in Australia, the UK and the United States.
Incidence of extra-articular manifestations in ankylosing spondylitis, psoriatic arthritis and undifferentiated spondyloarthritis: results from a national register-based cohort study
Authors: Bengtsson Karin , Forsblad-d'Elia Helena , Deminger Anna , Klingberg Eva , Dehlin Mats , Exarchou Sofia , Lindström Ulf , Askling Johan , Jacobsson Lennart T H
Published: October 2020

Objectives

To estimate the incidence and strength of association of extra-articular manifestations [EAMs, here: anterior uveitis (AU), IBD and psoriasis] in patients with AS, undifferentiated SpA (uSpA) and PsA, compared with controls.

Methods

Three mutually exclusive cohorts of patients aged 18–69 years with AS (n = 8517), uSpA (n = 10 245) and PsA (n = 22 667) were identified in the Swedish National Patient Register 2001–2015. Age-, sex- and geography-matched controls were identified from the Swedish Population Register. Follow-up began 1 January 2006, or six months after the first SpA diagnosis, whichever occurred later, and ended at the first date of the EAM under study, death, emigration, 70 years of age, and 31 December 2016. Incidence rates (IRs) and incidence rate ratios were calculated for each EAM, and stratified by sex and age.

Results

Incidence rate ratios for incident AU, IBD and psoriasis were significantly increased in AS (20.2, 6.2, 2.5), uSpA (13.6, 5.7, 3.8) and PsA (2.5, 2.3, n.a) vs controls. Men with AS and uSpA had significantly higher IRs per 1000 person-years at risk for incident AU than women with AS (IR 15.8 vs 11.2) and uSpA (IR 10.1 vs 6.0), whereas no such sex difference was demonstrated in PsA or for the other EAMs.

Conclusions

AU, followed by IBD and psoriasis, is the EAM most strongly associated with AS and uSpA. Among the SpA subtypes, AS and uSpA display a largely similar pattern of EAMs, whereas PsA has a considerably weaker association with AU and IBD.
Procedure-specific and patient-specific pain management for ambulatory surgery with emphasis on the opioid crisis
Authors: Raeder Johan
Published: October 2020

Purpose of review

Postoperative pain is frequent while, on the other hand, there is a grooving general concern on using effective opioid pain killers in view of the opioid crisis and significant incidence of opioid abuse. The present review aims at describing nonopioid measures in order to optimize and tailor perioperative pain management in ambulatory surgery.

Recent findings

Postoperative pain should be addressed both preoperatively, intraoperatively and postoperatively. The management should basically be multimodal, nonopioid and procedure-specific. Opioids should only be used when needed on top of multimodal nonopioid prophylaxis, and then limited to a few days at maximum, unless strict control is applied. The individual patient should be screened preoperatively for any risk factors for severe postoperative pain and/or any abuse potential.

Basic multimodal analgesia should start preoperatively or peroperatively and include paracetamol, cyclo-oxygenase (COX)-2 specific inhibitor or conventional nonsteroidal anti-inflammatory drug (NSAID) and in most cases dexamethasone and local anaesthetic wound infiltration. If any of these basic analgesics are contraindicated or there is an extra risk of severe postoperative pain, further measures may be considered: nerve-blocks or interfascial plane blocks, gabapentinnoids, clonidine, intravenous lidocaine infusion or ketamine infusion. In the abuse-prone patient, a preferably nonopioid perioperative approach should be aimed at.
Association Between Symbolic Play and Language: A Comparison Between Typically Developing Children and Children with Down Syndrome
Authors: Joginder Singh Susheel , Gan Brenda , Chu Shin Ying
Published: October 2020

Objective:

Language and symbolic play require the same underlying symbolic ability and develop parallel to one another. The aim of this study was to determine the association between symbolic play and vocabulary in typically developing children and children with Down syndrome in Malaysia.

Methods:

Twenty-five typically developing children and 25 children with Down syndrome aged between 12 and 36 months were involved in this study. They were recruited from an early intervention center and various kindergartens from the West Coast of Peninsular Malaysia. Their play skills were assessed using the Symbolic Play Test Second Edition, and information about their vocabulary was obtained through the MacArthur Bates Communicative Development Inventories that was filled out by their parents.

Results:

There was a significant difference in the vocabulary and symbolic play scores of children with Down syndrome compared with typically developing children. There was also a positive correlation between symbolic play scores and receptive and expressive vocabulary scores for both groups of children.

Conclusion:

When providing intervention, speech-language pathologists need to promote the development of symbolic play in addition to language, given the association between the two. They should also look into introducing an augmentative and alternative communication system to the children who demonstrate age-appropriate symbolic play skills but have trouble with symbolic language production.
Poor Graft and Patient Survival After Liver Transplantation in Sarcoidosis
Authors: Thuluvath Avesh J. , Savva Yulia , Chen Po-Hung
Published: October 2020

Goals and Background:

There are limited data on post-liver transplantation (LT) outcomes of patients with sarcoidosis.

Study:

We examined the clinical characteristics and post-LT outcomes of patients with sarcoidosis using the United Network for Organ Sharing database from 1985 to 2016 and compared them to patients (entire cohort as well as age, gender, and year of LT-matched counterparts) with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). For the matched design, a conditional logistic regression was used for categorical variables and marginal generalized estimating equation regression models for continuous variables. Survival functions were constructed using the Kaplan-Meier estimator.

Results:

A total of 206 patients with sarcoidosis, transplanted during the study period, were compared with 3933 patients with PBC and 5323 with PSC. In total, 197 patients with sarcoidosis were compared with 576 with PBC and 576 with PSC in the 1:3 matched analysis. The sarcoidosis group had a higher proportion of blacks (53.3%) and a higher prevalence of obesity and type II diabetes mellitus. The graft and patient survival for sarcoidosis patients were lower when compared with unmatched PBC and PSC patients. The results remained unchanged in the matched analysis. At 5-year, patient survival was ~15% lower for the sarcoidosis group when compared with PBC and PSC. In multivariate analysis using matched data, hazard ratios (HRs) for graft (HR=1.68, 95% confidence interval=1.03-2.75, P=0.04), and patient (HR=2.01, confidence interval=1.22-3.34, P<0.01) survival were higher for sarcoidosis.

Conclusions:

Patients who underwent LT for sarcoidosis had a lower graft and patient survival when compared with those with PBC or PSC. That being said, 66% of patients survived 5 years after transplantation, suggesting that LT is an acceptable option in this population.
The interconnection between lipoprotein(a), lipoprotein(a) cholesterol and true LDL-cholesterol in the diagnosis of familial hypercholesterolemia
Authors: Yeang Calvin , Willeit Peter , Tsimikas Sotirios
Published: October 2020

Purpose of review

Elevated levels of lipoprotein(a) [Lp(a)] are present in 30–50% of patients with familial hypercholesterolemia. The contribution of Lp(a) towards risk stratification of patients with familial hypercholesterolemia has been recently recognized, with studies showing a significantly worse prognosis if Lp(a) is elevated. However, the role of elevated Lp(a) in diagnosis of familial hypercholesterolemia is less well defined or accepted.

Recent findings

An important confounder in the diagnosis of familial hypercholesterolemia is the significant contribution of the cholesterol content on Lp(a) (Lp(a)-C) in individuals with elevated Lp(a). Because Lp(a)-C is incorporated into all clinical LDL-C measurements, it can contribute significantly to the cholesterol threshold diagnostic criteria for familial hypercholesterolemia used in most clinical algorithms.

In this review, we discuss the interrelationship of Lp(a), Lp(a)-C and correct LDL-C in the diagnosis and prognosis of familial hypercholesterolemia. Future studies of accurately measuring correct LDL-C or in using apoB-100 and Lp(a) criteria may overcome the limitations of using estimated LDL-C in the diagnosis of familial hypercholesterolemia in individuals with concomitant elevation of Lp(a).
Predictors of surgical management for paediatric orbital subperiosteal abscesses
Authors: Appachi Swathi , Bedwell Joshua R.
Published: October 2020

Purpose of review

Many paediatric orbital subperiosteal abscesses (SPA) are effectively managed conservatively with systemic antibiotics, but surgical drainage is required in some patients. This review aims to summarize the current literature to determine predictors of surgical intervention.

Recent findings

Nearly all the data regarding this topic come from analysis of retrospective case series. There is consensus that large volume SPAs require surgical drainage; however, the cutoff for volume differs between studies. Proptosis more than 5 mm, superior location of SPA and patient age more than 9 years are also all factors that may predispose towards surgical treatment.

A conservative approach may be trialled in younger patients with medial, smaller volume SPAs. Larger volume SPA, presence of proptosis, superior location of SPA and patient age more than 9 years should lower the threshold for considering surgical intervention. Given that many studies have been retrospective, future studies should be prospective and specifically aim to determine a cutoff for SPA volume.
Rhinovirus Detection in the Nasopharynx of Children Undergoing Cardiac Surgery Is Not Associated With Longer PICU Length of Stay: Results of the Impact of Rhinovirus Infection After Cardiac Surgery in Kids (RISK) Study
Authors: Roeleveld Peter Paul , Van Rijn Anneloes L. , de Wilde Rob B. P. , van Zwet Erik W. , Wink Jeroen , Rozendaal Lieke , Hogenbirk Karin , Hazekamp Mark G. , Man Wing Ho , Sidorov Igor , Kraakman Margriet E. M. , Claas Eric C. J. , de Jonge Evert , Kroes Aloys C. M. , de Vries Jutte J. C.
Published: October 2020

Objectives:

To determine whether children with asymptomatic carriage of rhinovirus in the nasopharynx before elective cardiac surgery have an increased risk of prolonged PICU length of stay.

Study Design:

Prospective, single-center, blinded observational cohort study.

Setting:

PICU in a tertiary hospital in The Netherlands.

Patients:

Children under 12 years old undergoing elective cardiac surgery were enrolled in the study after informed consent of the parents/guardians.

Interventions:

The parents/guardians filled out a questionnaire regarding respiratory symptoms. On the day of the operation, a nasopharyngeal swab was obtained. Clinical data were collected during PICU admission, and PICU/hospital length of stay were reported. If a patient was still intubated 3 days after operation, an additional nasopharyngeal swab was collected. Nasopharyngeal swabs were tested for rhinovirus and other respiratory viruses with polymerase chain reaction.

Measurements and Main RESULTS:

Of the 163 included children, 74 (45%) tested rhinovirus positive. Rhinovirus-positive patients did not have a prolonged PICU length of stay (median 2 d each; p = 0.257). Rhinovirus-positive patients had a significantly shorter median hospital length of stay compared with rhinovirus-negative patients (8 vs 9 d, respectively; p = 0.006). Overall, 97 of the patients (60%) tested positive for one or more respiratory virus. Virus-positive patients had significantly shorter PICU and hospital length of stay, ventilatory support, and nonmechanical ventilation. Virus-negative patients had respiratory symptoms suspected for a respiratory infection more often. In 31% of the children, the parents reported mild upper respiratory complaints a day prior to the cardiac surgery, this was associated with postextubation stridor, but no other clinical outcome measures.

Conclusions:

Preoperative rhinovirus polymerase chain reaction positivity is not associated with prolonged PICU length of stay. Our findings do not support the use of routine polymerase chain reaction testing for respiratory viruses in asymptomatic children admitted for elective cardiac surgery.
Growth and Neurodevelopment Outcomes in HIV-, Tenofovir-, and Efavirenz-Exposed Breastfed Infants in the PMTCT Option B+ Program in Malawi
Authors: Kapito-Tembo Atupele P. , Bauleni Andy , Wesevich Austin , Ongubo Dennis , Hosseinipour Mina C. , Dube Queen , Mwale Patrick , Corbett Amanda , Mwapasa Victor , Phiri Sam
Published: October 2020

Background:

Pregnant and breastfeeding women in Option B+ in Malawi received antiretroviral drugs (ARVs) containing efavirenz (EFV) and tenofovir disoproxil fumarate (TDF). However, effects on growth, renal, bone metabolism, and neurodevelopment of long-term exposure to low doses of these drugs through breast milk in HIV-exposed infants are unclear.

Methods:

Prospective cohorts of TDF-and-EFV–exposed and TDF-and-EFV–unexposed breastfed infants of HIV-infected and HIV-uninfected mothers in Option B+ were recruited in 2:1 ratio, respectively, followed from birth to 18 months. Infants with low birth weight, premature birth, and congenital abnormalities were excluded. Anthropometrics were assessed at birth, 6 weeks, 3, 6, 12, and 18 months. Neurodevelopment assessments used the Bayley Scales of Infant and Toddler Development III from 6 weeks. Creatinine, alkaline phosphatase, and phosphorus were assessed at 3, 6, and 12 months.

Results:

Of 260 HIV-and-ARV–exposed and 125 HIV-and-ARV–unexposed infants enrolled at birth, 87% and 57%, 78% and 59%, 77% and 54%, 73% and 51%, and 65% and 43% completed 6-weeks, 3, 6, 12, and 18 months visits, respectively. There were no significant differences in the mean Z-scores for length-for-age, weight-for-age, weight-for-length, mid-upper arm circumference-for-age, and head circumference-for-age between groups except at 6-weeks for length-for-age. No bone fractures occurred. Neurodevelopment outcomes were similar between groups. Of creatinine, alkaline phosphatase, and serum phosphate measurements, 1.7%, 2.6%, and 3.3% reached any toxicity levels grades 1–4, respectively, with no differences between groups.

Conclusion:

Long-term exposure to EFV and TDF through breastfeeding in infants of HIV-infected mothers does not seem to result in significant growth, neurodevelopment, renal, or bone adverse outcomes. Data support safety of breastfeeding through 18 months within the Option B+ program.
SARS-CoV-2 RNA detection using pooling of self-collected samples: Simple protocol may foster asymptomatic surveillance
Authors: Lopez-Lopes Giselle Ibette , de Cassia Compagnoli Carmona Rita , Silva Valéria Oliveira , Ahagon Cintia Mayumi , do Prado Lincoln Spinazola , dos Santos Fabiana Pereira , da Silva Daniela Bernardes Borges , de Oliveira Santos Katia Corrêa , Benega Margarete Aparecida , Ribeiro Willian Nery , Cilli Audrey , Matsuda Elaine Monteiro , Sardinha Afonso Ana Maria , Sampaio Tavares Timenetsky Maria do Carmo , de Macedo Brígido Luís Fernando
Published: October 2020

1

Background

Surveillance of COVID infection and isolation of infected individuals is one of the available tools to control the spread of SAR-CoV-2. Asymptomatic and pre symptomatic are responsible for substantial transmission. RNA or antigen tests are necessary to identify non-symptomatic individuals. We tested the feasibility of using samples pooling offering different collection alternatives (swab/throat wash/saliva) to volunteers of a public health institute.

Methods

We evaluated pool samples from frozen material from previously tested samples and a prospective collection from asymptomatic volunteers. Some collections were paired for comparison. Pools and some individual samples were extracted with QIAamp Viral RNA Mini Kit (Qiagen, USA) and/or Lucigen Quick Extract DNA extraction solution (BioSearch, USA) and submitted to rtPCR (Allplex, Seegene, Korea).

Results

A total of 240 samples from 130 new collections and 37 samples with known result were evaluated. Pool CT was generally higher than individual samples. Lucigen extraction showed higher CT, including false negative results for samples with high CT at Qiagen extraction. Paired Swab and TW samples showed comparable results. No volunteer from negative pools reported any symptom in the 2-3 days after collection.

Conclusions

Clinical samples pooling to detect SARS-CoV-2 RNA is feasible and an economical way to test for COVID-19, especially in surveillance strategies targeting more infectiousness, higher viremia individuals. The use of Lucigen reagents show lower sensibility that may lead to false negative results with lower viremia samples. Combining throat wash with saliva may provide and interesting self-collection alternative, but more comparative work is needed.
In vivoassessment of neurodegeneration in Spinocerebellar Ataxia type 7
Authors: Parker Jacob A. , Merchant Shabbir H. , Attaripour-Isfahani Sanaz , Cho Hyun Joo , McGurrin Patrick , Brooks Brian P. , La Spada Albert R. , Hallett Mark , Huryn Laryssa A. , Horovitz Silvina G.
Published: October 2020

Spinocerebellar Ataxia type 7 (SCA7) is a neurodegenerative disease characterized by progressive cerebellar ataxia and retinal degeneration. Increasing loss of visual function complicates the use of clinical scales to track the progression of motor symptoms, hampering our ability to develop accurate biomarkers of disease progression, and thus test the efficacy of potential treatments. In this cross-sectional study, we aimed to identify imaging measures of neurodegeneration, which may more accurately reflect SCA7 severity and progression. We analyzed diffusion tensor imaging (DTI) data collected from a cohort of 13 SCA7 patients and 14 healthy volunteers using two recent methodological advances: 1) a diffusion tensor-based image registration technique, and 2) a dual-compartment DTI model to control for the potential increase in extracellular CSF-like water due to neurodegeneration. These methodologies allowed us to assess both volumetric and microstructural abnormalities in both white and gray matter brain-wide in SCA7 patients for the first time. To measure tissue volume, we performed diffusion tensor-based morphometry (DTBM) using the tensor-based registration. To assess tissue microstructure, we computed the parenchymal mean diffusivity (pMD) and parenchymal fractional anisotropy (pFA) using the dual compartment model. This model also enabled us to estimate the parenchymal volume fraction (pVF), a measure of parenchymal tissue volume within a given voxel. While DTBM and pVF revealed tissue loss primarily in the brainstem, cerebellum, thalamus, and a subset of cerebral white matter tracts in patients, pMD and pFA detected microstructural abnormalities brain-wide (p< 0.05, FWE corrected; Hedge’sg> 1). This distinction was meaningful in terms of motor symptom severity, as we found that patient scores on the Scale for the Assessment and Rating of Ataxia correlated most strongly with cerebellar pVF (r= - 0.66,p= 0.015) and global white matter pFA (r= −0.64,p= 0.018). Since this contrast between focal tissue loss and global microstructural abnormality has previously been described in neuropathology, we believe the approach employed here is well suited for thein-vivoassessment of neurodegeneration. Moving forward, this approach could be applied to characterize the full spatiotemporal pattern of neurodegeneration in SCA7, and potentially develop an accurate imaging biomarker of disease progression.

Highlights

DTI study reveals brain-wide differences between SCA7 patients and controls.

DTI dual-compartment model controls for increased CSF-like free water in patients.

Tensor-based deformations show SCA7 tissue loss extends beyond cerebellum.

Focal atrophy, but global microstructural abnormalities were observed in SCA7.

Ataxia most correlated with cerebellar atrophy, global microstructural abnormality.