bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeted Nucleotide Repair of cyc1 Mutations in Saccharomyces cerevisiae Directed by Modified Single-Stranded DNA Oligonucleotides
Authors: Brachman Erin E , Kmiec Eric B
Published: April 2021

Modified single-stranded DNA oligonucleotides have been used to direct base changes in the CYC1 gene of Saccharomyces cerevisiae. In this process, the oligonucleotide is believed to hybridize to the target site through the action of a DNA recombinase and, once bound, DNA repair enzymes act to excise the nucleotide, replace it, and revert the gene to wild-type status. Nucleotide exchange exhibits a strand bias as, in most cases, a higher level of base reversal appears in cells in which the oligonucleotide is designed to hybridize to the nontemplate strand. But, in one case, a higher level was observed when an oligonucleotide complementary to the transcribed strand was used. Mutant haploid and diploid strains are reverted to wild type at this locus with approximately the same frequency and all strains take up the oligonucleotide with approximately equal efficiency. Some repair preference for certain base mismatches was observed; for example, T/T and C/C mispairs exhibited the highest degree of reactivity. Finally, we demonstrate that proteins involved in DNA pairing can enhance the repair activity up to 22-fold, while others affect the reaction minimally. Taken together, these results confirm the importance and versatility of yeast as a model system to elucidate the factors regulating the frequency of nucleotide exchange directed by oligonucleotides.
Transcription Profiling in Drosophila Eyes That Overexpress the Human Glaucoma-Associated Trabecular Meshwork-Inducible Glucocorticoid Response Protein/Myocilin (TIGR/MYOC)
Authors: Borrás Teresa , Morozova Tatiana V , Heinsohn Stefanie L , Lyman Richard F , Mackay Trudy F C , Anholt Robert R H
Published: April 2021

The availability of the human genome sequence together with sequenced genomes of several model organisms provides an unprecedented opportunity to utilize comparative genomic approaches for the discovery of genes that contribute to human disease. We have used transgenic flies to establish an experimental paradigm for the discovery of genes that might be involved in the development of glaucoma, a prevalent disease affecting a large segment of the population. Inherited mutations in the trabecular meshwork-inducible glucocorticoid response protein/myocilin (TIGR/MYOC) are associated with juvenile glaucoma and some cases of adult primary open angle glaucoma. The interrelationships between TIGR/MYOC and the development of glaucoma, however, are not understood. We show that overexpression of human TIGR/MYOC in the eyes of Drosophila melanogaster results in distortion of ommatidia accompanied by fluid discharge. High-density oligonucleotide microarrays identified altered expression of 50 transcripts in response to TIGR/MYOC overexpression, including homologs of aquaporin-4 and cytochrome-P450, previously associated with glaucoma, and several proteins of unknown function. We found that expression of Swiss Cheese, a neurodegenerative protein, increased 34-fold and that its human ortholog, neuropathy target esterase, is also upregulated in response to adenovirus-mediated overexpression of TIGR/MYOC in perfused postmortem human eyes. Our observations establish the Drosophila eye as an advantageous system for the discovery of genes that are associated with glaucoma.
Arabidopsis MET1 Cytosine Methyltransferase Mutants
Authors: Kankel Mark W , Ramsey Douglas E , Stokes Trevor L , Flowers Susan K , Haag Jeremy R , Jeddeloh Jeffrey A , Riddle Nicole C , Verbsky Michelle L , Richards Eric J
Published: April 2021

We describe the isolation and characterization of two missense mutations in the cytosine-DNA-methyl-transferase gene, MET1, from the flowering plant Arabidopsis thaliana. Both missense mutations, which affect the catalytic domain of the protein, led to a global reduction of cytosine methylation throughout the genome. Surprisingly, the met1-2 allele, with the weaker DNA hypomethylation phenotype, alters a well-conserved residue in methyltransferase signature motif I. The stronger met1-1 allele caused late flowering and a heterochronic delay in the juvenile-to-adult rosette leaf transition. The distribution of late-flowering phenotypes in a mapping population segregating met1-1 indicates that the flowering-time phenotype is caused by the accumulation of inherited defects at loci unlinked to the met1 mutation. The delay in flowering time is due in part to the formation and inheritance of hypomethylated fwa epialleles, but inherited defects at other loci are likely to contribute as well. Centromeric repeat arrays hypomethylated in met1-1 mutants are partially remethylated when introduced into a wild-type background, in contrast to genomic sequences hypomethylated in ddm1 mutants. ddm1 met1 double mutants were constructed to further our understanding of the mechanism of DDM1 action and the interaction between two major genetic loci affecting global cytosine methylation levels in Arabidopsis.
Maximum-Likelihood Estimation of Relatedness
Authors: Milligan Brook G
Published: April 2021

Relatedness between individuals is central to many studies in genetics and population biology. A variety of estimators have been developed to enable molecular marker data to quantify relatedness. Despite this, no effort has been given to characterize the traditional maximum-likelihood estimator in relation to the remainder. This article quantifies its statistical performance under a range of biologically relevant sampling conditions. Under the same range of conditions, the statistical performance of five other commonly used estimators of relatedness is quantified. Comparison among these estimators indicates that the traditional maximum-likelihood estimator exhibits a lower standard error under essentially all conditions. Only for very large amounts of genetic information do most of the other estimators approach the likelihood estimator. However, the likelihood estimator is more biased than any of the others, especially when the amount of genetic information is low or the actual relationship being estimated is near the boundary of the parameter space. Even under these conditions, the amount of bias can be greatly reduced, potentially to biologically irrelevant levels, with suitable genetic sampling. Additionally, the likelihood estimator generally exhibits the lowest root mean-square error, an indication that the bias in fact is quite small. Alternative estimators restricted to yield only biologically interpretable estimates exhibit lower standard errors and greater bias than do unrestricted ones, but generally do not improve over the maximum-likelihood estimator and in some cases exhibit even greater bias. Although some nonlikelihood estimators exhibit better performance with respect to specific metrics under some conditions, none approach the high level of performance exhibited by the likelihood estimator across all conditions and all metrics of performance.
Bayesian Inference of Recent Migration Rates Using Multilocus Genotypes
Authors: Wilson Gregory A , Rannala Bruce
Published: April 2021

A new Bayesian method that uses individual multilocus genotypes to estimate rates of recent immigration (over the last several generations) among populations is presented. The method also estimates the posterior probability distributions of individual immigrant ancestries, population allele frequencies, population inbreeding coefficients, and other parameters of potential interest. The method is implemented in a computer program that relies on Markov chain Monte Carlo techniques to carry out the estimation of posterior probabilities. The program can be used with allozyme, microsatellite, RFLP, SNP, and other kinds of genotype data. We relax several assumptions of early methods for detecting recent immigrants, using genotype data; most significantly, we allow genotype frequencies to deviate from Hardy-Weinberg equilibrium proportions within populations. The program is demonstrated by applying it to two recently published microsatellite data sets for populations of the plant species Centaurea corymbosa and the gray wolf species Canis lupus. A computer simulation study suggests that the program can provide highly accurate estimates of migration rates and individual migrant ancestries, given sufficient genetic differentiation among populations and sufficient numbers of marker loci.
Coupled Mutagenesis Screens and Genetic Mapping in Zebrafish
Authors: Rawls John F , Frieda Matthew R , McAdow Anthony R , Gross Jason P , Clayton Chad M , Heyen Candy K , Johnson Stephen L
Published: April 2021

Forward genetic analysis is one of the principal advantages of the zebrafish model system. However, managing zebrafish mutant lines derived from mutagenesis screens and mapping the corresponding mutations and integrating them into the larger collection of mutations remain arduous tasks. To simplify and focus these endeavors, we developed an approach that facilitates the rapid mapping of new zebrafish mutations as they are generated through mutagenesis screens. We selected a minimal panel of 149 simple sequence length polymorphism markers for a first-pass genome scan in crosses involving C32 and SJD inbred lines. We also conducted a small chemical mutagenesis screen that identified several new mutations affecting zebrafish embryonic melanocyte development. Using our first-pass marker panel in bulked-segregant analysis, we were able to identify the genetic map positions of these mutations as they were isolated in our screen. Rapid mapping of the mutations facilitated stock management, helped direct allelism tests, and should accelerate identification of the affected genes. These results demonstrate the efficacy of coupling mutagenesis screens with genetic mapping.
Chromosomal Lesion Suppression and Removal in Escherichia coli via Linear DNA Degradation
Authors: Miranda Anabel , Kuzminov Andrei
Published: April 2021

RecBCD is a DNA helicase/exonuclease implicated in degradation of foreign linear DNA and in RecA-dependent recombinational repair of chromosomal lesions in E. coli. The low viability of recA recBC mutants vs. recA mutants indicates the existence of RecA-independent roles for RecBCD. To distinguish among possible RecA-independent roles of the RecBCD enzyme in replication, repair, and DNA degradation, we introduced wild-type and mutant combinations of the recBCD chromosomal region on a low-copy-number plasmid into a ΔrecA ΔrecBCD mutant and determined the viability of resulting strains. Our results argue against ideas that RecBCD is a structural element in the replication factory or is involved in RecA-independent repair of chromosomal lesions. We found that RecBCD-catalyzed DNA degradation is the only activity important for the recA-independent viability, suggesting that degradation of linear tails of σ-replicating chromosomes could be one of the RecBCD’s roles. However, since the weaker DNA degradation capacity due a combination of the RecBC helicase and ssDNA-specific exonucleases restores viability of the ΔrecA ΔrecBCD mutant to a significant extent, we favor suppression of chromosomal lesions via linear DNA degradation at reversed replication forks as the major RecA-independent role of the RecBCD enzyme.
Mode of Selection and Experimental Evolution of Antifungal Drug Resistance in Saccharomyces cerevisiae
Authors: Anderson James B , Sirjusingh Caroline , Parsons Ainslie B , Boone Charles , Wickens Claire , Cowen Leah E , Kohn Linda M
Published: April 2021

We show that mode of selection, degree of dominance of mutations, and ploidy are determining factors in the evolution of resistance to the antifungal drug fluconazole in yeast. In experiment 1, yeast populations were subjected to a stepwise increase in fluconazole concentration over 400 generations. Under this regimen, two mutations in the same two chromosomal regions rose to high frequency in parallel in three replicate populations. These mutations were semidominant and additive in their effect on resistance. The first of these mutations mapped to PDR1 and resulted in the overexpression of the ABC transporter genes PDR5 and SNQ2. These mutations had an unexpected pleiotropic effect of reducing the residual ability of the wild type to reproduce at the highest concentrations of fluconazole. In experiment 2, yeast populations were subjected to a single high concentration of fluconazole. Under this regimen, a single recessive mutation appeared in each of three replicate populations. In a genome-wide screen of ∼4700 viable deletion strains, 13 were classified as resistant to fluconazole (ERG3, ERG6, YMR102C, YMR099C, YPL056C, ERG28, OSH1, SCS2, CKA2, SML1, YBR147W, YGR283C, and YLR407W). The mutations in experiment 2 all mapped to ERG3 and resulted in the overexpression of the gene encoding the drug target ERG11, but not PDR5 and SNQ2. Diploid hybrids from experiments 1 and 2 were less fit than the parents in the presence of fluconazole. In a variation of experiment 2, haploids showed a higher frequency of resistance than diploids, suggesting that degree of dominance and ploidy are important factors in the evolution of antifungal drug resistance.
An in Vivo Analysis of the vestigial Gene in Drosophila melanogaster Defines the Domains Required for Vg Function
Authors: MacKay Julie O , Soanes Kelly H , Srivastava Ajay , Simmonds Andrew , Brook William J , Bell John B
Published: April 2021

Considerable evidence indicates an obligate partnership of the Drosophila melanogaster Vestigial (VG) and Scalloped (SD) proteins within the context of wing development. These two proteins interact physically and a 56-amino-acid motif within VG is necessary and sufficient for this binding. While the importance of this SD-binding domain has been clearly demonstrated both in vitro and in vivo, the remaining portions of VG have not been examined for in vivo function. Herein, additional regions within VG were tested for possible in vivo functions. The results identify two additional domains that must be present for optimal VG function as measured by the loss of ability to rescue vg mutants, to induce ectopic sd expression, and to perform other normal VG functions when they are deleted. An in vivo study such as this one is fundamentally important because it identifies domains of VG that are necessary in the cellular context in which wing development actually occurs. The results also indicate that an additional large portion of VG, outside of these two domains and the SD-binding domain, is dispensable in the execution of these normal VG functions.
Chromosome-level genome assembly of the hard-shelled mussel Mytilus coruscus, a widely distributed species from the temperate areas of East Asia
Authors: Yang Jin-Long , Feng Dan-Dan , Liu Jie , Xu Jia-Kang , Chen Ke , Li Yi-Feng , Zhu You-Ting , Liang Xiao , Lu Ying
Published: April 2021

Background

The hard-shelled mussel (Mytilus coruscus) is widely distributed in the temperate seas of East Asia and is an important commercial bivalve in China. Chromosome-level genome information of this species will contribute not only to the development of hard-shelled mussel genetic breeding but also to studies on larval ecology, climate change biology, marine biology, aquaculture, biofouling, and antifouling.

Findings

We applied a combination of Illumina sequencing, Oxford Nanopore Technologies sequencing, and high-throughput chromosome conformation capture technologies to construct a chromosome-level genome of the hard-shelled mussel, with a total length of 1.57 Gb and a median contig length of 1.49 Mb. Approximately 90.9% of the assemblies were anchored to 14 linkage groups. We assayed the genome completeness using BUSCO. In the metazoan dataset, the present assemblies have 89.4% complete, 1.9% incomplete, and 8.7% missing BUSCOs. Gene modeling enabled the annotation of 37,478 protein-coding genes and 26,917 non-coding RNA loci. Phylogenetic analysis showed that M. coruscus is the sister taxon to the clade including Modiolus philippinarum and Bathymodiolus platifrons. Conserved chromosome synteny was observed between hard-shelled mussel and king scallop, suggesting that this is shared ancestrally. Transcriptomic profiling indicated that the pathways of catecholamine biosynthesis and adrenergic signaling in cardiomyocytes might be involved in metamorphosis.

Conclusions

The chromosome-level assembly of the hard-shelled mussel genome will provide novel insights into mussel genome evolution and serve as a fundamental platform for studies regarding the planktonic-sessile transition, genetic diversity, and genomic breeding of this bivalve.
Sex ratios and natal origins of green turtles from feeding grounds in the Southwest Atlantic Ocean
Authors: de Almeida João Paulo Felix Augusto , dos Santos Robson Guimarães , Mott Tamí
Published: April 2021

Potential effects of climate change on living species are a widely debated topic. Species with temperature-dependent sex determination can be particularly impacted by warmer temperatures because unbalanced sex ratios could threaten population viability. In sea turtles, sex ratio estimates have highlighted the potential feminization of current populations, which tends to increase since warmer temperatures would generate more females. Here, we evaluated temporal variation in sex ratios of green turtles from feeding grounds of the Southwest Atlantic Ocean (SWA) using data from a 7-year time frame, from 2010 to 2016. We also evaluated natal origins of female and male green turtles from SWA based on mitochondrial DNA. Sex ratios of juvenile and adult green turtles were generally female-skewed across collection years. We identified 11 haplotypes in northeast SWA, and the haplotype composition of females and males was slightly different. Likewise, the estimated the natal origins of females and males were divergent. Ascension Island was estimated to be the main source of females while Guinea Bissau was estimated to be the main source of males. Studies evaluating natal origins of females and males independently are rare, this study provides one of the first assessments of the kind for green turtles in the SWA.
Non-judicial rights review of counterterrorism policies: The role of fundamental rights in the making of the counterterrorism database and the data retention legislation in Germany
Authors: Lang Andrej
Published: April 2021

This article analyzes the institutions, procedures, and mechanisms of non-judicial rights review in Germany, focusing on the policy field of national security. Although there is currently a fruitful constitutional debate about the virtues and vices of non-judicial review in the Anglo-Saxon legal world, this debate has virtually gone unnoticed in German scholarship, and the role of political actors in protecting fundamental rights is neglected. This article studies how rights considerations affect the making of antiterrorism policy in Germany and what mechanisms exist in the legislative process to ensure the creation of rights-respecting antiterrorism policy. It is methodologically designed as a case study and focuses on two controversial pieces of legislation: the Data Retention Act and the Anti-Terror Database Act. The article reveals that Germany features a bureaucratic model of rights review in which rights issues are primarily negotiated between the two constitutional ministries—the Ministry of Justice and the Ministry of the Interior—which are mutually entangled in an institutionalized competitive relationship. This model complements the German strong-form model of judicial review and has the effect that the role of rights is mostly mediated through the Constitutional Court’s case law and the prospect of judicial review. The article further demonstrates that these non-judicial rights-review processes are surrounded by a legalistic and rather formalistic political culture that is not conducive to a principled and deliberative engagement with fundamental rights. Overall, rights are prominently considered and clearly have a constraining effect, however, often ultimately recede when weighed against the objective of ensuring collective security in the wake of the threat of terrorism.
A Leray Model for the Orlik–Solomon Algebra
Authors: Bibby Christin , Denham Graham , Feichtner Eva Maria
Published: April 2021

We construct a combinatorial generalization of the Leray models for hyperplane arrangement complements. Given a matroid and some combinatorial blow-up data, we give a presentation for a bigraded (commutative) differential graded algebra. If the matroid is realizable over $\mathbb {C}$, this is the familiar Morgan model for a hyperplane arrangement complement, embedded in a blowup of projective space. In general, we obtain a cdga that interpolates between the Chow ring of a matroid and the Orlik–Solomon algebra. Our construction can also be expressed in terms of sheaves on combinatorial blowups of geometric lattices. As a key technical device, we construct a monomial basis via a Gröbner basis for the ideal of relations. Combining these ingredients, we show that our algebra is quasi-isomorphic to the classical Orlik–Solomon algebra of the matroid.
Supremacy Smugglers? Islam in the Legacy of Theological Liberalism
Authors: Schmiedel Ulrich
Published: April 2021

This article interrogates the interpretation of Islam in the legacy of theological liberalism. Ernst Troeltsch (1865–1923) has been labelled the figurehead of such liberalism. Islam is a recurrent referent in his thought, running through his theological and philosophical writings. Whereas studies such as Tomoko Masuzawa’s immensely influential The Invention of World Religions contend that Troeltsch’s conceptualization of religion smuggles assumptions of the supremacy of Christianity from theological into non-theological research on religion, I argue that Troeltsch’s characterization of Islam clarifies how he both constructs and collapses the supremacy smuggling for which he is criticized. For the current controversies about Islam in the European and the American public square, Troeltsch is instructive because he captures both the problems and the promises of the theological thinking that came to be called “liberal” for the study of religion.
Biodegradable Temporizing Matrix Reconstruction of Complex Perineal Burn Wound: A Case Report
Authors: Concannon Elizabeth , Coghlan Patrick , DamKat Thomas Lindsay , Solanki Nicholas S , Greenwood John E
Published: April 2021

This case report details our experience using a two-stage Biodegradable Temporizing Matrix (NovoSorb® PolyNovo Ltd) and autograft for acute reconstruction of a complex perineal burn wound in an elderly comorbid patient. A 77-year-old man sustained 42% full-thickness burns extending circumferentially from bilateral thighs and buttocks, across the entire perineal and genital regions up to his mid-trunk, following self-immolation using an accelerant. Early total burn wound excision was carried out with acute application of Biodegradable Temporizing Matrix to all affected sites. Excellent integration and vascularization of Biodegradable Temporizing Matrix took place despite the challenge of intermittent fecal contamination affecting the perineal and buttock burn sites and matrix colonization with multidrug-resistant organisms. Delamination and serial split-thickness skin autografting were carried out 42 days after the first matrix application with complete and robust graft take. Perineal burns present a reconstructive challenge due to the proximity of specialized structures such as the genitalia, urethral, and anal orifices. Restoration of complex anatomy and function may be required after debridement with increased risks of infection, contracture formation, and mortality compared with burns affecting other anatomical sites. Two-stage Biodegradable Temporizing Matrix represents a reliable reconstruction option for complex extensive perineal wounds in frail elderly patients, despite an unfavorable local microbial environment.
Genomic-, phenotypic-, and toxicity-based safety assessment and probiotic potency of Bacillus coagulans IDCC 1201 isolated from green malt
Authors: Bang Won Yeong , Ban O-Hyun , Lee Bo Som , Oh Sangki , Park Chanmi , Park Mi-Kyung , Jung Sung Keun , Yang Jungwoo , Jung Young Hoon
Published: April 2021

Probiotics are beneficial microorganisms, and the evaluation of their safety for human use in the food industry has become critical. This study examines the safety of Bacillus coagulans IDCC 1201 isolated from green malt by analyzing its genomic and phenotypic characteristics and determining its toxicity. The presence of antibiotic resistance and toxigenic genes and gene transferability were investigated using whole-genome analysis. The strain's hemolytic and enzyme activities, minimum inhibitory concentrations of antibiotics, and biogenic amine and D-lactate production were also examined. Furthermore, the principal properties of B. coagulans IDCC 1201 as probiotics, such as resistance to abiotic stress and intestinal adhesion, were studied. The whole-genome analysis demonstrated that B. coagulans IDCC 1201 had no antibiotic resistance or toxigenic genes; the strain was susceptible to the nine antibiotics proposed by the European Food Safety Authority. Moreover, this strain lacked hemolytic and β-glucuronidase activities. Additionally, it was confirmed that B. coagulans IDCC 1201 produced undesirable metabolites, including biogenic amines or D-lactate, at a safe level. Finally, the strain exhibited functional potential as a probiotic in terms of abiotic tolerance, such as bile tolerance and intestinal adhesion in in vitro experiments. In conclusion, B. coagulans IDCC 1201 can be considered as a safe probiotic with regard to human health.
Statement in Support of Revising the Uniform Determination of Death Act and in Opposition to a Proposed Revision
Authors: Shewmon D Alan
Published: April 2021

Discrepancies between the Uniform Determination of Death Act (UDDA) and the adult and pediatric diagnostic guidelines for brain death (BD) (the “Guidelines”) have motivated proposals to revise the UDDA. A revision proposed by Lewis, Bonnie and Pope (the RUDDA), has received particular attention, the three novelties of which would be: (1) to specify the Guidelines as the legally recognized “medical standard,” (2) to exclude hypothalamic function from the category of “brain function,” and (3) to authorize physicians to conduct an apnea test without consent and even over a proxy’s objection. One hundred seven experts in medicine, bioethics, philosophy, and law, spanning a wide variety of perspectives, have come together in agreement that while the UDDA needs revision, the RUDDA is not the way to do it. Specifically, (1) the Guidelines have a non-negligible risk of false-positive error, (2) hypothalamic function is more relevant to the organism as a whole than any brainstem reflex, and (3) the apnea test carries a risk of precipitating BD in a non-BD patient, provides no benefit to the patient, does not reliably accomplish its intended purpose, and is not even absolutely necessary for diagnosing BD according to the internal logic of the Guidelines; it should at the very least require informed consent, as do many procedures that are much more beneficial and less risky. Finally, objections to a neurologic criterion of death are not based only on religious belief or ignorance. People have a right to not have a concept of death that experts vigorously debate imposed upon them against their judgment and conscience; any revision of the UDDA should therefore contain an opt-out clause for those who accept only a circulatory-respiratory criterion.
Memories, Mementos, and Memorialization of Young Unaccompanied Afghans Navigating within Europe
Authors: LØnning Moa Nyamwathi , Kohli Ravi K S
Published: April 2021

This article considers memories, mementos, and memorialization in stories by unaccompanied young people and their journeys within Europe. It looks at their ‘navigation’ of remembering and forgetting and how this intertwines with movement and stillness. It is based on a study about Afghan males aged 15–24 years in Norway and Greece. Participants differed in terms of their backgrounds, migration projects, and their legal status. In their various circumstances, their narratives point to how memories unfold, are shared, must be negotiated, and sometimes, forgotten as they navigate towards a sense of safety and a sustainable future. They also point to how mementos may take different forms while on the move, as traces along the migration trail that have the potential to become part of the memories of others who come across them. Finally, their narratives point to practices of memorialization, and how they too are intimately connected to remembering and forgetting.
Correlation and co-localization of QTL for stomatal density, canopy temperature, and productivity with and without drought stress inSetaria
Authors: Prakash Parthiban Thathapalli , Banan Darshi , Paul Rachel E , Feldman Maximilian J , Xie Dan , Freyfogle Luke , Baxter Ivan , Leakey Andrew D B
Published: April 2021

Mechanistic modeling indicates that stomatal conductance could be reduced to improve water use efficiency (WUE) in C4 crops. Genetic variation in stomatal density and canopy temperature was evaluated in the model C4 genus, Setaria. Recombinant inbred lines (RILs) derived from a Setaria italica×Setaria viridis cross were grown with ample or limiting water supply under field conditions in Illinois. An optical profilometer was used to rapidly assess stomatal patterning, and canopy temperature was measured using infrared imaging. Stomatal density and canopy temperature were positively correlated but both were negatively correlated with total above-ground biomass. These trait relationships suggest a likely interaction between stomatal density and the other drivers of water use such as stomatal size and aperture. Multiple quantitative trait loci (QTL) were identified for stomatal density and canopy temperature, including co-located QTL on chromosomes 5 and 9. The direction of the additive effect of these QTL on chromosome 5 and 9 was in accordance with the positive phenotypic relationship between these two traits. This, along with prior experiments, suggests a common genetic architecture between stomatal patterning and WUE in controlled environments with canopy transpiration and productivity in the field, while highlighting the potential of Setaria as a model to understand the physiology and genetics of WUE in C4 species.
Escaping from pollution: Air pollution and the settlement intentions of floating migrants in Chinese cities
Authors: Jia Kai , Chen Shaowei
Published: April 2021

Understanding the mechanisms underlying floating migrants’ settlement intentions is vital for guiding evidence-based policies for China’s urbanisation and regional economic development. While prior studies have identified various determinants of migrants’ settlement decisions, little attention has been paid to the effects of environmental pollution on these decisions. To fill this gap, this study utilises a unique data set combining individual-level data from a national survey and city-level data obtained from various sources to investigate the effects of air pollution on floating migrants’ settlement intentions in China. Using a novel instrumental variable, our regression results show significantly negative impacts of air pollution on both migrants’ permanent settlement intention and their expected length of settlement. Additionally, these impacts are stronger for the skilled migrants compared to the less skilled ones. These findings imply that environmental pollution should be seriously considered when promoting urbanisation in China and beyond.
Effects of solar flares and coronal mass ejections on Earth’s horizontal magnetic field and solar wind parameters during the minimum solar cycle 24
Authors: Syed Zafar S N A , Umar R , Sabri N H , Jusoh M H , Dagang A N , Yoshikawa A
Published: April 2021

Previous studies have reported that coronal mass ejections (CMEs) and solar flares lead to the development of huge storms and high-speed streams. Our aim in this paper is to investigate the response of the geomagnetic index SYM/H to the solar wind parameters, such as solar wind speed V, dynamic pressure P, input energy IE and the interplanetary magnetic field (IMF) Bz component, associated with solar flares and CME events. The response of the ground geomagnetic field (H-component) to the solar wind parameters and the IMF Bz component at three low-latitude stations has also been analysed. Our findings show that the delay of the solar wind changes in the Earth’s magnetosphere in response to the weak geomagnetic storm (SYM/H = −30 nT) at the beginning of 2014 December 21. A weak storm of SYM/H = −30 nT in the middle of 2014 November 5 is suggested by a low magnetic reconnection process in the magnetosphere. In addition, the strong southward IMF Bz component and high solar wind changes in the magnetosphere system, which were a result of the X2.0 solar flare event and the CMEs on 2014 October 27, responded to the moderate storm (SYM/H = −60 nT) at the beginning of 2014 October 28. This dynamic physical process in the magnetosphere caused by solar wind variation is seen to excite the Earth’s H-component through ultra low frequency at the ground-based magnetometers at the BCL (Vietnam), TIR (India) and SCN (Indonesia) stations during the geomagnetic storm. This study relates to seismic investigations and geomagnetic-induced current on the ground.
A maximum X-ray luminosity scale of disc-dominated tidal destruction events
Authors: Mummery Andrew
Published: April 2021

We develop a model describing the dynamical and observed properties of disc-dominated tidal disruption events (TDEs) around black holes with the lowest masses (M ≲ few × 106M⊙). TDEs around black holes with the lowest masses are most likely to reach super-Eddington luminosities at early times in their evolution. By assuming that the amount of stellar debris that can form into a compact accretion disc is set dynamically by the Eddington luminosity, we make a number of interesting and testable predictions about the observed properties of bright soft-state X-ray TDEs and optically bright, X-ray dim TDEs. We argue that TDEs around black holes of the lowest masses will expel the vast majority of their gravitationally bound debris into a radiatively driven outflow. A large-mass outflow will obscure the innermost X-ray producing regions, leading to a population of low black hole mass TDEs that are only observed at optical and UV energies. TDE discs evolving with bolometric luminosities comparable to their Eddington luminosity will have near constant (i.e. black hole mass independent) X-ray luminosities, of order LX, max ≡ LM ∼ 1043 − 1044 erg s−1. The range of luminosity values stems primarily from the range of allowed black hole spins. A similar X-ray luminosity limit exists for X-ray TDEs in the hard (Compton scattering dominated) state, and we therefore predict that the X-ray luminosity of the brightest X-ray TDEs will be at the scale LM(a) ∼ 1043 − 1044 erg s−1, independent of black hole mass and accretion state. These predictions are in strong agreement with the properties of the existing population (∼40 sources) of observed TDEs.
Posthumous trading patterns affecting artwork prices
Authors: De Silva Dakshina G , Kosmopoulou Georgia , Pownall Rachel A J , Press Robert
Published: April 2021

This study aims to identify factors contributing to price fluctuations in artworks after an artist’s death. With access to information on seller characteristics from a historical dataset of all art auctions that took place in London between 1741 and 1913, we investigate how trading patterns and network effects at auctions affect art sales prices. Following an artist’s death, we capture dynamic effects in sales patterns and find that prices decline by 7%. We attribute this decline on the confluence of non-strategic and strategic effects, first on a frequent lack of access to professional consultation and secondly on changes in trading patterns of art dealers posthumously. Our results highlight the long-term influence of those factors on high valued art.
SARS-CoV-2 Viral Persistence Based on Cycle Threshold Value and Liver Injury in Patients With COVID-19
Authors: Wong Grace Lai-Hung , Yip Terry Cheuk-Fung , Wong Vincent Wai-Sun , Tse Yee-Kit , Hui David Shu-Cheong , Lee Shui-Shan , Yeoh Eng-Kiong , Chan Henry Lik-Yuen , Lui Grace Chung-Yan
Published: April 2021

Background

Liver injury in patients with coronavirus disease 2019 (COVID-19) is common and prognostic. Direct viral tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for angiotensin-converting enzyme 2 receptors in hepatocytes may be one of the mechanisms of liver injury. We aimed to determine the role of viral persistence of SARS-CoV-2, based on cycle threshold (Ct) value, in liver injury in COVID-19.

Methods

This was a territory-wide retrospective cohort study of all public hospitals in Hong Kong. Laboratory-confirmed COVID-19 was identified. Serial liver biochemistries and Ct values of SARS-CoV-2 RNA were analyzed.

Results

We identified 7622 COVID-19 patients (mean age, 47 years; 48.2% male) diagnosed from March 24 to January 1, 2021, who had serial liver biochemistries and Ct values. A total of 1363 (17.9%) COVID-19 patients had alanine transferase (ALT)/aspartate aminotransferase (AST) elevations with 2 temporal patterns—early (within first 14 days of symptom onset) and late (>14 days from symptom onset). COVID-19 patients with ALT/AST elevations had a lower Ct value at admission (23 vs 25; P < .001), day 5 (24 vs 26; P < .001), and day 20 (31 vs 32; P < .001) after admission, compared with those without ALT/AST elevations. COVID-19 patients with ALT/AST elevations had a longer duration from first positive to first negative reverse transcription polymerase chain reaction test for SARS-CoV-2 (13 vs 9 days; P < .001). ALT/AST elevation and presence of diabetes were independent risk factors of viral persistence.

Conclusions

Liver injury in COVID-19 is linked to a higher SARS-CoV-2 viral load during the early phase of infection, signifying a possible direct viral injury to the liver. Prolonged viral persistence of SARS-CoV-2 is associated with liver injury.
Post-COVID-19 WHO Reform: Ethical Considerations
Authors: de Campos-Rudinsky Thana C
Published: April 2021

This study argues against the expansive approach to the WHO reform, according to which to be a better global health leader, WHO should do more, be given more power and financial resources, have more operational capacities, and have more teeth by introducing more coercive monitoring and compliance mechanisms to its IHR. The expansive approach is a political problem, whose root cause lies in ethics: WHO’s political overambition is grounded on WHO’s lack of conceptual clarity on what good leadership means and what health (as a human right) means. This study presents this ethical analysis by putting forth an alternative: the humble approach to the WHO reform. It argues that to be a better leader, WHO should do much less and have a much narrower mandate. More specifically, WHO should focus exclusively on coordination efforts, by ensuring truthful, evidence-based, consistent, and timely shared communications regarding PHEIC among WHO member-states and other global health stakeholders, if the organization desires to be a real global health leader whose authority the international community respects and whose guidance people trust.
Epidemiology of physical inactivity in Nigeria: a systematic review and meta-analysis
Authors: Adeloye Davies , Ige-Elegbede Janet O , Auta Asa , Ale Boni M , Ezeigwe Nnenna , Omoyele Chiamaka , Dewan Mary T , Mpazanje Rex G , Agogo Emmanuel , Alemu Wondimagegnehu , Gadanya Muktar A , Harhay Michael O , Adebiyi Akindele O
Published: April 2021

Background

Physical activity is crucial to preventing noncommunicable diseases. This study aimed to provide up-to-date evidence on the epidemiology of insufficient physical activity across Nigeria to increase awareness and prompt relevant policy and public health response.

Methods

A systematic literature search of community-based studies on physical inactivity was conducted. We constructed a meta-regression epidemiologic model to determine the age-adjusted prevalence and number of physically inactive persons in Nigeria for 1995 and 2020.

Results

Fifteen studies covering a population of 13 814 adults met our selection criteria. The pooled crude prevalence of physically inactive persons in Nigeria was 52.0% (95% CI: 33.7–70.4), with prevalence in women higher at 55.8% (95% CI: 29.4–82.3) compared to men at 49.3% (95% CI: 24.7–73.9). Across settings, prevalence of physically inactive persons was significantly higher among urban dwellers (56.8%, 35.3–78.4) compared to rural dwellers (18.9%, 11.9–49.8). Among persons aged 20–79 years, the total number of physically inactive persons increased from 14.4 million to 48.6 million between 1995 and 2020, equivalent to a 240% increase over the 25-year period.

Conclusions

A comprehensive and robust strategy that addresses occupational policies, town planning, awareness and information, and sociocultural and contextual issues is crucial to improving physical activity levels in Nigeria.
Building supply chain capacity for neglected tropical diseases: experience from the Ascend West and Central Africa programme
Authors: Villacorta Linaza Rocio , Garner Timothy , Genovezos Chantelle
Published: April 2021

The Ascend West and Central Africa programme, funded by the UK Foreign, Commonwealth and Development Office (FCDO) is supporting integrated preventative chemotherapy for up to five neglected tropical diseases (NTDs), including intestinal worms, lymphatic filariasis, river blindness, trachoma and schistosomiasis. The programme is implemented across 13 countries by a consortium of four leading international development partners: Sightsavers, Liverpool School of Tropical Medicine, Schistosomiasis Control Initiative Foundation and Mott Macdonald. This paper presents messages learnt from country assessments that took place prior to the global outbreak of coronavirus disease 2019 (COVID-19). These messages remain relevant post-COVID-19, with greater priority being given to the challenges for national NTD programmes in continuing to deliver mass drug administration (MDA) during the pandemic. Stakeholder coordination from the earliest stages of the pandemic has occurred at two levels: in the first mile with global partners of the NTD Supply Chain Forum and in the last mile with implementing partners in each country. This has been instrumental to manage delayed MDA, including the impact delays have on the shipment of NTD donated drugs and the distribution of stock held in country. The Ascend West and Central Africa programme is supporting countries with the resumption of MDA through a risk assessment and mitigation action (RAMA) process.
Inadequate community knowledge about sickle cell disease among the Indian tribal population: a formative assessment in a multicentric intervention study
Authors: Babu Bontha V , Sridevi Parikipandla , Surti Shaily , Ranjit Manoranjan , Bhat Deepa , Sarmah Jatin , Sudhakar Godi , Sharma Yogita
Published: April 2021

Background

Sickle cell disease (SCD) is a serious public health problem, with >300 000 affected births worldwide each year. About 73% of the SCD-affected people in India belong to the tribal population. The Government of India is planning to implement a programme for SCD and hence people's knowledge of SCD is crucial. This paper reports the SCD-related knowledge among the Indian tribal population.

Methods

As part of a formative assessment before an intervention, data were collected from 9837 adults from 24 primary health centre areas of six states. Each community's knowledge of SCD was elicited through an interviewer-administered pretested questionnaire. Univariate and multivariate analyses were conducted.

Results

Overall, 32.1% (CI 31.2 to 33.1%) of participants had heard of SCD, 7.9% (CI: 7.3 to 8.4%) knew that SCD is hereditary, 19.4% (CI: 18.7 to 20.3%) knew that a blood test can diagnose SCD and 23.9% (CI: 23.1 to 24.8%) knew that SCD is treatable. Only 13.1% (CI: 12.4 to 13.8%) knew that SCD can be prevented. No more than 16% knew about any SCD symptoms. Multiple logistic regression revealed some predictors of basic knowledge (i.e. had heard of SCD).

Conclusions

There is a gross inadequacy of knowledge about SCD in the Indian tribal population. This study warrants implementing a health education programme as a part of the SCD programme.
The Leaf Bacterial Microbiota of Female and Male Kiwifruit Plants in Distinct Seasons: Assessing the Impact ofPseudomonas syringaepv.actinidiae
Authors: Ares Aitana , Pereira Joana , Garcia Eva , Costa Joana , Tiago Igor
Published: April 2021

The Pseudomonas syringae pv. actinidiae pandemic has been compromising the production of the kiwifruit industry in major producing countries. Abiotic factors and plant gender are known to influence the disease outcome. To better understand their impact, we have determined the diversity of the leaf bacterial communities using the V5-V6 region of the 16S ribosomal RNA gene amplicon on the Illumina MiSeq sequencing platform. Healthy and diseased female and male kiwifruit plants were analyzed in two consecutive seasons: spring and autumn. This work describes whether the season, plant gender, and presence of P. syringae pv. actinidiae can affect the leaf bacterial community. Fifty bacterial operational taxonomic units were identified and assigned to five phyla distributed by 14 different families and 23 genera. The leaves of healthy female and male kiwi plants share most of the identified bacterial populations, which undergo major seasonal changes. In both cases, a substantial increase of the relative abundance of genus Methylobacterium is observed in autumn. The presence of P. syringae pv. actinidiae induced profound changes on leaf bacterial community structures, translated into a reduction in the relative abundance of previously dominant genera that had been found in healthy plants; namely, Hymenobacter, Sphingomonas, and Massilia spp. The impact of P. syringae pv. actinidiae was less pronounced in the bacterial community structure of male plants in both seasons. Some of the naturally occurring genera have the potential to act as antagonists or as enhancers of the defense mechanisms, paving the way for environmentally friendly and sustainable disease control.
Circulating Level of Myelin Basic Protein Predicts Postherpetic Neuralgia
Authors: Yang Xin , Shen Yu , Ding Zhuofeng , Tian Ying , Hu Jiajia , Guo Qulian , Huang Changsheng
Published: April 2021

Objectives:

Patients with herpes zoster (HZ) would benefit from accurate prediction of whether they are likely to develop postherpetic neuralgia (PHN). We investigated whether a circulating biomarker of neuronal damage could be a predictor of PHN in this nonmatched prospective, nested, case-control study.

Materials and Methods:

We included patients with HZ who were within 90 days after rash onset. Volunteers without a history of HZ were recruited as controls. We evaluated epidemiologic factors and circulating neuronal damage biomarkers, including cell-free DNA, myelin basic protein (MBP), and soluble protein-100B (S100B). We conducted logistic regression analyses to develop a prediction model of PHN.

Results:

We found that cell-free DNA and MBP levels were higher in patients with HZ (n=71) than in controls (n=37). However, only MBP level was higher in patients who developed PHN (n=25), in comparison with those who did not (n=46). MBP level and 3 clinical factors, age, acute pain severity, and response to treatment drugs were identified as independent predictors of PHN. Receiver operating characteristic (ROC) curve analysis showed that the prediction made using a combination of MBP level and clinical factors had an area under ROC curve of 0.853 (95% confidence interval: 0.764 to 0.943), which was better than prediction using clinical factors alone (area under ROC curve: 0.823, 95% confidence interval: 0.728 to 0.917).

Discussion:

Our results indicate that circulating MBP level in patients with HZ is a predictor for PHN. The combination of clinical predictors and MBP level enhanced the prediction performance.