bluuebunny/crossref_metadata_2025 huggingface dataset:
TWO MULTIALLELIC MATING COMPATIBILITY LOCI SEPARATELY REGULATE ZYGOTE FORMATION AND ZYGOTE DIFFERENTIATION IN THE MYXOMYCETE PHYSARUM POLYCEPHALUM
Authors: Youngman Philip J , Anderson Roger W , Holt Charles E
Published: April 2021

The mating of Physarum polycephalum amoebae, the ultimate consequence of which is a "plasmodium," was recently shown to be governed by two compatibility loci, matA (or mt) and matB (DEE1 978; YOUNGMAeNt aZ. 1979), We present evidence that matA and matB separately regulate two discrete stages of mating: in the first stage, amoebae (which are normally haploid) fuse in pairs, with a specificity determined by matB genotype, to form diploid zygotes; subsequent differentiation of the zygotes into plasmodia is regulated by matA and is unaffected by matB. Mixtures of amoebae carrying unlike matA and matB alleles formed diploids to the extent of 10 to 15% of the cells present, and the diploids differentiated into plasmodia. When only the matB alleles differed, diploid cells still formed to a comparable (5 to 101%) extent, but rather than differentiating, these diploids remained amoebae. When strains carried the same alleles of matB, formation of diploid cells was greatly reduced: in like matB, like-matd mixtures, none of 320 cells examined was diploid; in like maiB, unlike mat-A mixtures, differentiating diploids could be detected, but at only IO-3 to 10-2 the frequency of unlike-matB, unlike-matA mixtures. The nondifferentiating diploid amoebae recovered from unlike-matB, like-matA mixtures were genetically stable through extensive growth, even though they grew more slowly than haploids (10-hr us. 8-hr doubling period), and could be crossed with both haploids and diploids. The results of such higher ploidy and mixed ploidy crosses indicate that karyogamy does not invariably accompany zygote formation and differentiation.
THIRD-CHROMOSOME MUTAGEN-SENSITIVE MUTANTS OF DROSOPHILA MELANOGASTER
Authors: Boyd J B , Golino M D , Shaw K E S , Osgood C J , Green M M
Published: April 2021

A total of 34 third chromosomes of Drosophila melanogaster that render homozygous larvae hypersensitive to killing by chemical mutagens have been isolated. Genetic analyses have placed responsible mutations in more than eleven complementation groups. Mutants in three complementation groups are strongly sensitive to methyl methanesulfonate, those in one are sensitive to nitrogen mustard, and mutants in six groups are hypersensitive to both mutagens. Eight of the ten loci mapped fall within 15% of the genetic map that encompasses the centromere of chromosome 3. Mutants from four of the complementation groups are associated with moderate to strong meiotic effects in females. Preliminary biochemical analyses have implicated seven of these loci in DNA metabolism.
GENETICS OF FERTILITY RESTORATION IN THE C-GROUP OF CYTOPLASMIC MALE STERILITY IN MAIZE
Authors: Kheyr-Pour A , Gracen V E , Everett H L
Published: April 2021

The genetics of fertility restoration of cms-C group cytoplasm of maize was studied using crosses involving stable maintainer lines and lines that restored full pollen fertility. Pollen fertility in the sources of cms-C sterile cytoplasms studied was restored by a single dominant restorer (Rf4) gene. The fertility restoration was sporophytic. Allelism tests among five restorer lines showed that they all apparently carried the same alleles (Rf4 Rf4). Similar tests also demonstrated that seven nonrestoring maintainer lines had apparently the same genotype (rf4 rf4), although a partial "late break" of fertility was observed at low levels in some maintainer crosses. Comparative studies among different cms-C sources (C, Bb, ES, PR and RB) indicated that similar inheritance of fertility restoration was involved. The data indicated that a single, dominant Rf gene is involved in the restoration of several C-group cytoplasms, at least in the lines studied here. This is the first single-gene, sporophytic restorer system described in maize to date.
GERMLINE HYPERMUTABILITY IN DROSOPHILA AND ITS RELATION TO HYBRID DYSGENESIS AND CYTOTYPE
Authors: Engels William R
Published: April 2021

In its hypermutable state, an unstable singed allele, snw, mutates in the germline to two other alleleic forms at a total frequency usually between 40 and 60%. In its stable state, the mutation rate of snw is essentially zero. Its state depends on an extrachromosomal condition indistinguishable from a property called cytotype previously studied as a component of hybrid dysgenesis. Of the two known systems of hybrid dysgenesis, denoted P-M and I-R, snw hypermutability is determined by the P-M system and appears to be independent of the I-R system. Cytotype, as defined by the control of snw mutability, is self-reproducing in the cytoplasm or nucleoplasm of the germline through at least two generations. However, it is not entirely autonomous, being ultimately determined by the chromosomes after sufficiently many generations of backcrossing. This combination of chromosomal and extrachromosomal transmission agrees well with previous studies on cytotype. Temperature differences have little effect on the mean mutation rates, but they have a pronounced effect on the intrinsic variance among individuals. The latter effect suggests that high temperatures reduce germ-cell survival during the development of dysgenic flies. Chromosomal rearrangements produce no apparent effects on the behavior of snw. Hypermutability is thought to be caused by the excision or other alteration of an inserted genetic element in the snw gene. This element might be a copy of the "P factor," which is though to be a mobile sequence capable of causing female sterility and other dysgenic traits in the P-M system.
GENETIC DRIFT AND ESTIMATION OF EFFECTIVE POPULATION SIZE
Authors: Nei Masatoshi , Tajima Fumio
Published: April 2021

The statistical properties of the standardized variance of gene frequency changes (a quantity equivalent to Wright's inbreeding coefficient) in a random mating population are studied, and new formulae for estimating the effective population size are developed. The accuracy of the formulae depends on the ratio of sample size to effective size, the number of generations involved (t), and the number of loci or alleles used. It is shown that the standardized variance approximately follows the Χ2 distribution unless t is very large, and the confidence interval of the estimate of effective size can be obtained by using this property. Application of the formulae to data from an isolated population of Dacus oleae has shown that the effective size of this population is about one tenth of the minimum census size, though there was a possibility that the procedure of sampling genes was improper.
AGENTS THAT CAUSE A HIGH FREQUENCY OF GENETIC CHANGE FROM [psi
+] TO [psi
-] IN SACCHAROMYCES CEREVISIAE
Authors: Tuite M F , Mundy C R , Cox B S
Published: April 2021

The [psi] factor of yeast is cytoplasmically inherited. Singh, Helms and Sherman (1979) reported that high concentrations of KCl and of ethylene glycol induce the genetic change from [psi  +] to [psi  -]. In this study, the following agents have been shown to induce the same genetic change: guanidine hydrochloride at 1 mm, dimethyl sulfoxide at 2.5% v/v and ethanol or methanol at 10% v/v. It is likely that a number of other agents also cause the change, namely 2 m glycerol, m succinate, m glutamate and m MgCl2. Most of these agents induce the change at very high frequencies; with some, the frequency is 100%. Although the observed phenotypic change can also occur as a result of chromosomal gene mutation, no changes of this type were identified. Some of the agents also cause mutation from [rho  +] to [rho  -] and from killer to sensitive.
AUTOSOMAL FACTORS WITH CORRELATED EFFECTS ON THE ACTIVITIES OF THE GLUCOSE 6-PHOSPHATE AND 6-PHOSPHOGLUCONATE DEHYDROGENASES IN DROSOPHILA MELANOGASTER
Authors: Laurie-Ahlberg C C , Williamson J H , Cochrane B J , Wilton A N , Chasalow F I
Published: April 2021

Isogenic lines, in which chromosomes sampled from natural populations of D. melanogaster are substituted into a common genetic background, were used to detect and partially characterize autosomal factors that affect the activities of the two pentose phosphate pathway enzymes, glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). The chromosome 3 effects on G6PD and 6PGD are clearly correlated; the chromosome 2 effects, which are not so great, also appear to be correlated, but the evidence in this case is not so strong. Examination of activity variation of ten other enzymes revealed that G6PD and 6PGD are not the only pair of enzymes showing a high positive correlation, but it is among the highest in both sets of lines. In addition, there was some evidence that the factor(s) affecting G6PD and 6PGD may also affect two other metabolically related enzymes, transaldolase and phosphoglucose isomerase.—Rocket immunoelectrophoresis was used to estimate specific CRM levels for three of the enzymes studied: G6PD, 6PGD and ME. This experiment shows that a large part of the activity variation is accounted for by variation in CRM level (especially for chromosome 3 lines), but there remains a significant fraction of the genetic component of activity variation that is not explained by CRM level.—These results suggest that the autosomal factors are modifiers involved in regulation of the expression of the X-linked structural genes for G6PD and 6PGD, but a role in determining part of the enzymes′ primary structure cannot be excluded with the present evidence.
MODULATION OF PROTEIN LEVELS IN CHROMOSOMAL DOSAGE SERIES OF MAIZE: THE BIOCHEMICAL BASIS OF ANEUPLOID SYNDROMES
Authors: Birchler James A , Newton Kathleen J
Published: April 2021

Genetically defined dosage series of chromosome arms 1L, 3L, 4S, 5L, 7L, 9S, 10L and combinations of 1L-3L, collectively spanning approximately one-third of the maize genome, were examined for alterations in the expression of total protein profiles in scutellar tissue. The major effects found were negative correlations of specific proteins with the dosage of particular regions in a manner similar to that previously described for enzyme activity levels (Birchler 1979). Chromosome arms 1L, 4S and 5L produced the most severe negative effects, with 3L and 7L exhibiting this phenomenon to a lesser degree. Positive correlations of certain proteins were observed with the dosage of the 1L, 3L, 5L and 7L regions. The structural locus of one of the major scutellar proteins (PRO) is present in the long arm of chromosome 1 (Schwartz 1979), but exhibits compensation in a dosage series involving whole-arm comparisons. Multiple factors in 1L affect the level of the protein. The compound TB-1La-3L4759-3 (1L 0.20-0.39) has a slight negative effect on PRO, while TB-1La-3Le (1L 0.20-0.58) and TB-1La-3L5267 (1L 0.20-0.72) have a more pronounced negative influence. The level of this protein is not altered by the dosage of 3L. These observations suggest that compensation is brought about by the cancellation of a positive structural gene dosage effect by the negative inverse effect. Other regions of the genome that contribute to the control of PRO levels are 4S and 5L. Total protein profiles were also compared in haploid, diploid and tetraploid maize as a comparison to the aneuploid series. Most proteins exhibit structural-gene-dosage effects through the ploidy series, but others show a positive effect greater than expected from varying the structural genes. Still others are negatively affected by ploidy changes. In general, the ploidy alterations are not as great as predicted from the cumulative action of the aneuploid effects. The bearing of these observations on the biochemical basis of aneuploid syndromes is discussed.
ANALYSIS OF A CONTROLLING-ELEMENT MUTATION AT THE Adh LOCUS OF MAIZE
Authors: Osterman John C , Schwartz Drew
Published: April 2021

A Ds-suppressed Adh mutant was isolated by the allyl alcohol pollen selection technique. The mutant produces a reduced level of an altered thermolabile enzyme suggesting that the Ds element is inserted in the Adh structural gene. The mutant protein is enzymatically active and does not differ detectably in size from the progenitor protein. A number of possible explanations for the data are presented.
NET GENETIC AND TEMPORARY EPISTATIC OR MATERNAL ENVIRONMENTAL RESPONSES TO SELECTION FOR EGG PRODUCTION IN CHICKENS
Authors: Bennett G L , Dickerson G E , Gowe R S , McAllister A J , Emsley J A B
Published: April 2021

The difference between progeny from selected and unselected parents (T) was experimentally partitioned into net genetic change (GA), temporary favorable epistatic combinations (GEP) and egg-transmitted maternal environment (M) in two strains of Leghorns selected over 14 years for early pure-strain egg production. Differences among progeny from selected sires and dams, selected sires only, selected dams only, unselected sires and dams and the parental generation were equated to expected GA, GEP and M responses for each trait. Total response was 3.3% for early egg number, 3.7% for total egg number, 0.5% for egg weight, 3.8% for early egg mass and 4.2% for total egg mass. Among progeny that survived the test period and were judged to be normal, total response was 2.6% for total number of eggs, 3.0% for early egg mass and 3.1% for total egg mass. The percentage of T attributed to GA was 9% for early egg number, 24% for total egg number, 43% for early egg mass and 47% for total egg mass; but 52% for total egg number, 98% for early egg mass and 71% for total egg mass of normal survivors. Temporary maternal selection responses (M) were (1) positive for number of eggs and egg masses, (2) greater for all progeny than for normal survivors, and (3) increased with progeny age. The results suggest that M was caused by reduced egg-transmitted disease. Epistatic selection response was positive for earlier sexual maturity and for number of eggs, but negative for egg weight and thus was small for egg masses. Temporary epistatic and maternal responses can explain overestimation of additive genetic response from offspring-parent regression or from replicated single-generation selection and apparent superiority of mass selection over family or combined selection.
GENETICALLY INDUCED MITOTIC EXCHANGE IN THE HETEROCHROMATIN OF DROSOPHILA MELANOGASTER
Authors: Robbins Leonard G
Published: April 2021

Multiple copies of the 18s and 28sribosomal RNA cistrons are present in both the Xand Y chromosomes of Drosophila melanogaster.Data are presented here that identify a locus, Rex,that causes exchange-like events between duplicated ribosomal complexes at the ends of an attached-XY chromosome. Rex:(1) is close to or in the basal heterochromatin of the Xchromosome; (2)is semidominant and (its effect) is temperature sensitive; (3) acts maternally; and (4) affects behavior of paternally derived attached-XY chromosomes shortly after fertilization. Though, at this point, the existence of Rexis known only from its effects on behavior of a particular compound chromosome, it presents intriguing possibilities for understanding regulation of chromosome behavior and organization of the ribosomal cistrons.
A duplication on chromosome 16q12 affecting theIRXBgene cluster is associated with autosomal dominant cone dystrophy with early tritanopic color vision defect
Authors: Kohl Susanne , Llavona Pablo , Sauer Alexandra , Reuter Peggy , Weisschuh Nicole , Kempf Melanie , Dehmelt Florian Alexander , Arrenberg Aristides B , Sliesoraityte Ieva , Zrenner Eberhart , van Schooneveld Mary J , Rudolph Günther , Kühlewein Laura , Wissinger Bernd
Published: April 2021

Cone dystrophies are a rare subgroup of inherited retinal dystrophies and hallmarked by color vision defects, low or decreasing visual acuity and central vision loss, nystagmus and photophobia. Applying genome-wide linkage analysis and array comparative genome hybridization, we identified a locus for autosomal dominant cone dystrophy on chromosome 16q12 in four independent multigeneration families. The locus is defined by duplications of variable size with a smallest region of overlap of 608 kb affecting the IRXB gene cluster and encompasses the genes IRX5 and IRX6. IRX5 and IRX6 belong to the Iroquois (Iro) protein family of homeodomain-containing transcription factors involved in patterning and regionalization of embryonic tissue in vertebrates, including the eye and the retina. All patients presented with a unique progressive cone dystrophy phenotype hallmarked by early tritanopic color vision defects. We propose that the disease underlies a misregulation of the IRXB gene cluster on chromosome 16q12 and demonstrate that overexpression of Irx5a and Irx6a, the two orthologous genes in zebrafish, results in visual impairment in 5-day-old zebrafish larvae.
Quantification of persister formation ofEscherichia colileveraging electronic cell counting and semi-mechanistic pharmacokinetic/pharmacodynamic modelling
Authors: Seeger Johanna , Michelet Robin , Kloft Charlotte
Published: April 2021

Background

Persister formation of Escherichia coli under fluoroquinolone exposure causes treatment failure and promotes emergence of resistant strains. Semi-mechanistic pharmacokinetic/pharmacodynamic modelling of data obtained from in vitro infection model experiments comprehensively characterizes exposure–effect relationships, providing mechanistic insights.

Objectives

To quantify persister formation of E. coli under levofloxacin exposure and to explain the observed growth-kill behaviour, leveraging electronic cell counting and pharmacokinetic/pharmacodynamic modelling.

Methods

Three fluoroquinolone-resistant clinical E. coli isolates were exposed to levofloxacin in static and dynamic in vitro infection model experiments. Complementary to plate counting, bacterial concentrations over time were quantified by electronic cell counting and amalgamated in a semi-mechanistic pharmacokinetic/pharmacodynamic model (1281 bacterial and 394 levofloxacin observations).

Results

Bacterial regrowth was observed under exposure to clinically relevant dosing regimens in the dynamic in vitro infection model. Electronic cell counting facilitated identification of three bacterial subpopulations: persisters, viable cells and dead cells. Two strain-specific manifestations of the levofloxacin effect were identified: a killing effect, characterized as a sigmoidal Emax model, and an additive increase in persister formation under levofloxacin exposure. Significantly different EC50 values quantitatively discerned levofloxacin potency for two isolates displaying the same MIC value: 8 mg/L [EC50 = 17.2 (95% CI = 12.6–23.8) mg/L and 8.46 (95% CI = 6.86–10.3) mg/L, respectively]. Persister formation was most pronounced for the isolate with the lowest MIC value (2 mg/L).

Conclusions

The developed pharmacokinetic/pharmacodynamic model adequately characterized growth-kill behaviour of three E. coli isolates and unveiled strain-specific levofloxacin potencies and persister formation. The mimicked dosing regimens did not eradicate the resistant isolates and enhanced persister formation to a strain-specific extent.
Stress-constrained topology optimization for material extrusion polymer additive manufacturing
Authors: Liu Jikai , Yan Jingjing , Yu Huangchao
Published: April 2021

This paper presents a comprehensive numerical and experimental study on stress-constrained topology optimization for Fused Deposition Modeling (FDM) additive manufacturing. The qp method is employed to avoid the singularity issue of stress-constrained problems. The P-norm function with stability transformation is adopted to build the global stress constraint with iterative corrections to eliminate the gap between the maximum local stress and the P-norm stress. The Heaviside projection is employed to generate clear-cut 0–1 designs. Two benchmark examples have been studied with the numerical algorithm. Experiments are performed on the topologically optimized MBB beam to investigate the impact of the FDM process parameters, including deposition path direction, building direction, and slicing layer height, on the resulted structural strength. The stress-constrained designs without and with Heaviside projection are comparatively tested with experiments. The stress-minimization designs subject to different P-norm parameters are compared both numerically and experimentally. Experiments show that the deposition path direction and the building direction evidently affect the derived structural strength. Moreover, overthin structural members may severely degrade the structural strength due to manufacturing and loading uncertainties.
Syntax and the Illusion of Fit: How Grammatical Subject Influences Persuasion
Authors: Ostinelli Massimiliano , Luna David
Published: April 2021

We examine how the grammatical subject of a marketing claim affects persuasion. We refer to this phenomenon as the subject bias and introduce the distinction between users subjects (where product users are the grammatical subject of a sentence) and product subjects (where the product is the grammatical subject of the sentence). We find that users subjects can lead to an illusion of fit, where a reader believes that an offer provides a better fit for oneself than for other consumers, which, in turn, affects persuasion. Eight experiments, including a field study, provide support for the subject bias in different domains, ranging from online dating services to medical products, and uncover the underlying process along with its boundary conditions while ruling out alternative explanations. These findings advance the understanding of the antecedents and consequences of idiosyncratic fit and introduce a novel language effect in consumer research that has theoretical, methodological, and practical implications.
On the Form and Origins of the Bizarre Sex Chromosomal System of the Mandarin Vole
Authors: Roy Scott William
Published: April 2021

Recent work has illuminated the bizarre sex chromosomal system of the mandarin vole, Lasiopodomys mandarinus. The ancestral sex chromosomes have been replaced by 4 neo-sex chromosomes. These sex chromosomes show non-Mendelian inheritance and epistatic sex determination, as well as unaccounted-for karyotype frequencies. I suggest a model to account for the complex observed inheritance patterns. The proposed model combines putative adaptations previously observed in rodents, including feminizing X chromosomes and Y-biased spermatogenesis, with a novel proposed mechanism of genomic imprinting of X-linked genes during oogenesis in XY females. Alternative possibilities are also discussed. The proposed scenario provides a relatively simple and testable model for the function and origins of a remarkably complex mammalian sex chromosomal system.
Equality of Opportunity and Antitrust: The Curious Case of College Rankings
Authors: Stavroulaki Theodosia
Published: April 2021

Rankings increasingly dominate our world. We use them to choose just about everything—from which pizza or ice cream to buy, to which doctors to trust with our health, to which universities to trust with our intellectual growth and flourishing. But should we trust them? Taking popular academic rankings as an example, such as the U.S. News rankings, this article contends not necessarily, for several reasons. First, because as this article argues, the U.S. News rankings may mislead rather than inform consumers. Second, by fueling a prestige battle between universities, the U.S. News rankings incentivize universities to harm cultural and economic diversity—important facets of educational quality. These conclusions, critical in their own right, raise additional important but underexplored questions for antitrust law. Should universities be allowed to boycott the U.S. News rankings so that they can free themselves of the prestige battle in which they participate? Can an “antirankings boycott” be justified by antitrust law on the basis that it may allow universities to promote diversity and increase access to the underserved? Although these questions are not easy to address, they are at the heart of this article.
Be My Safe Haven: Parent–Child Relationships and Emotional Health During COVID-19
Authors: Bate Jordan , Pham Phoebe T , Borelli Jessica L
Published: April 2021

Objective

Since March 2020, millions of children have been confined to their homes and restricted from in-person activities, radically changing the dynamics of parent–child relationships. This study examines the association between coronavirus disease 2019 (COVID-19) impact and the mental health of parents and school-aged children; specifically, whether qualities of the parent–child relationship moderated the relationship between parents’ emotional health (EH) and children’s emotional and behavioral health (EBH).

Methods

Data from this Internet-based study of a community sample were collected in March–May 2020. Parents (N = 158, 92.4% White, 96.2% female) reported on COVID-19 impacts, their own EH, perceptions of their relationship with their eldest child between 6 and 12 years-old, and the EBH of that child.

Results

Responses to questions about COVID-19 impact were assigned weighted values and used to create a COVID-19 impact scale. Hierarchical linear regressions revealed that greater COVID-19 impact was associated with greater parents’ EH issues only, and parents’ EH was a significant positive predictor of children’s EBH. Positive qualities and conflict in the parent–child relationship moderated the link between parents’ and children’s EH. At higher levels of relationship conflict and lower levels of positivity, there were stronger positive associations between parents’ and children’s EH. Parent–child relationship quality did not moderate the association between parents’ EH and children’s behavioral health (BH).

Conclusions

These cross-sectional study results suggest that beyond focusing on symptom management, families may benefit from supports targeting the parent–child relationship. Insights and implications for practitioners are discussed.
A rare case of idiopathic intrauterine intestinal volvulus complicated with intestinal perforation: a case report from Syria
Authors: Khoury Victor , Omran Ammar , Taishori Norma
Published: April 2021

Fetal intestinal volvulus is rare, but it is a serious condition due to its life-threatening complications.

The bowel loop becomes twisted; thus, impaired venous return leads to bowel necrosis.

Prenatal volvulus is most secondary to intestinal atresia, arterial supply defect or without any underlying cause, with consideration that cystic fibrosis is the cause of the intestinal obstruction, because of meconium ileus.

We report a case of prenatal volvulus complicated with intestinal perforation and meconium peritonitis in the context of meconium ileus.
How unbiased statistical methods lead to biased scientific discoveries: A case study of the Efron–Petrosian statistic applied to the luminosity-redshift evolution of gamma-ray bursts
Authors: Bryant Christopher Michael , Osborne Joshua Alexander , Shahmoradi Amir
Published: April 2021

Statistical methods are frequently built upon assumptions that limit their applicability to certain problems and conditions. Failure to recognize these limitations can lead to conclusions that may be inaccurate or biased. An example of such methods is the non-parametric Efron–Petrosian test statistic used in the studies of truncated data. We argue and show how the inappropriate use of this statistical method can lead to biased conclusions when the assumptions under which the method is valid do not hold. We do so by reinvestigating the evidence recently provided by multiple independent reports on the evolution of the luminosity/energetics distribution of cosmological Long-duration Gamma-Ray Bursts (LGRBs) with redshift. We show that the effects of detection threshold have been likely significantly underestimated in the majority of previous studies. This underestimation of detection threshold leads to severely incomplete LGRB samples that exhibit strong apparent luminosity-redshift or energetics-redshift correlations. We further confirm our findings by performing extensive Monte Carlo simulations of the cosmic rates and the luminosity/energy distributions of LGRBs and their detection process.
A massive open cluster hiding in full sight
Authors: Negueruela I , Chené A-N , Tabernero H M , Dorda R , Borissova J , Marco A , Kurtev R
Published: April 2021

Obscuration and confusion conspire to limit our knowledge of the inner Milky Way. Even at moderate distances, the identification of stellar systems becomes compounded by the extremely high density of background sources. Here, we provide a very revealing example of these complications by unveiling a large, massive, young cluster in the Sagittarius arm that has escaped detection until now despite containing more than 30 stars brighter than G = 13. By combining Gaia DR2 astrometry, Gaia and 2MASS photometry, and optical spectroscopy, we find that the new cluster, which we name Valparaiso 1, located at $\sim 2.3\,$ kpc, is about 75 Ma old and includes a large complement of evolved stars, among which we highlight the 4 d classical Cepheid CM Sct and an M-type giant that probably represents the first detection of an asymptotic giant branch star in a Galactic young open cluster. Although strong differential reddening renders accurate parameter determination unfeasible with the current data set, direct comparison to clusters of similar age suggests that Valparaiso 1 was born as one of the most massive clusters in the solar neighbourhood, with an initial mass close to $10^{4}\, \mathrm{M}_{\odot }$.
The contribution of globular clusters to cosmic reionization
Authors: Ma Xiangcheng , Quataert Eliot , Wetzel Andrew , Faucher-Giguère Claude-André , Boylan-Kolchin Michael
Published: April 2021

We study the escape fraction of ionizing photons (fesc) in two cosmological zoom-in simulations of galaxies in the reionization era with halo mass Mhalo ∼ 1010 and $10^{11}\, \mathrm{ M}_{\odot }$ (stellar mass M* ∼ 107 and $10^9\, \mathrm{ M}_{\odot }$) at z = 5 from the Feedback in Realistic Environments project. These simulations explicitly resolve the formation of proto-globular clusters (GCs) self-consistently, where 17–39 per cent of stars form in bound clusters during starbursts. Using post-processing Monte Carlo radiative transfer calculations of ionizing radiation, we compute fesc from cluster stars and non-cluster stars formed during a starburst over ∼100 Myr in each galaxy. We find that the averaged fesc over the lifetime of a star particle follows a similar distribution for cluster stars and non-cluster stars. Clusters tend to have low fesc in the first few Myr, presumably because they form preferentially in more extreme environments with high optical depths; the fesc increases later as feedback starts to destroy the natal cloud. On the other hand, some non-cluster stars formed between cluster complexes or in the compressed shells at the front of a superbubble can also have high fesc. We find that cluster stars on average have comparable fesc to non-cluster stars. This result is robust across several star formation models in our simulations. Our results suggest that the fraction of ionizing photons from proto-GCs to cosmic reionization is comparable to the cluster formation efficiencies in high-redshift galaxies and thus proto-GCs likely contribute an appreciable fraction of photons but are not the dominant sources for reionization.
Multiwavelength monitoring and reverberation mapping of a changing look event in the Seyfert galaxy NGC 3516
Authors: Oknyansky V L , Brotherton M S , Tsygankov S S , Dodin A V , Bao D-W , Zhao B-X , Du P , Burlak M A , Ikonnikova N P , Tatarnikov A M , Belinski A A , Fedoteva A A , Shatsky N I , Mishin E O , Zheltouhov S G , Potanin S A , Wang J-M , McLane J N , Kobulnicky H A , Dale D A , Zastrocky T E , Maithil J , Olson K A , Adelman C , Carter Z , Murphree A M , Oeur M , Schonsberg S , Roth T
Published: April 2021

We present the results of photometric and spectroscopic monitoring campaigns of the changing look AGN NGC 3516 carried out in 2018 to 2020 covering the wavelength range from the X-ray to the optical. The facilities included the telescopes of the CMO SAI MSU, the 2.3-m WIRO telescope, and the XRT and UVOT of Swift. We found that NGC 3516 brightened to a high state and could be classified as Sy1.5 during the late spring of 2020. We have measured time delays in the responses of the Balmer and He ii λ4686 lines to continuum variations. In the case of the best-characterized broad H β line, the delay to continuum variability is about 17 d in the blue wing and is clearly shorter, 9 d, in the red, which is suggestive of inflow. As the broad lines strengthened, the blue side came to dominate the Balmer lines, resulting in very asymmetric profiles with blueshifted peaks during this high state. During the outburst the X-ray flux reached its maximum on 2020 April 1 and it was the highest value ever observed for NGC 3516 by the Swift observatory. The X-ray hard photon index became softer, ∼1.8 in the maximum on 2020 April 21 compared to the mean ∼0.7 during earlier epochs before 2020. We have found that the UV and optical variations correlated well (with a small time delay of 1–2 d) with the X-ray until the beginning of 2020 April, but later, until the end of 2020 June, these variations were not correlated. We suggest that this fact may be a consequence of partial obscuration by Compton-thick clouds crossing the line of sight.
A pilot study of interplanetary scintillation with FAST
Authors: Liu Li-Jia , Peng Bo , Yu Lei , Yu Ye-Zhao , Lu Ji-Guang , Liu Bin , Chang O , Bisi M M ,   FAST Collaboration, Qiu Yu-Hai , Zhang Xi-Zhen , Zhang Cheng-Min , Xiong Ming , Fallow R A , Tokumaru M , Mejia-Ambriz Julio
Published: April 2021

Observations of interplanetary scintillation (IPS) are an efficient remote-sensing method to study the solar wind and inner heliosphere. From 2016 to 2018, some distinctive observations of IPS sources like 3C 286 and 3C 279 were accomplished with the Five-hundred-meter Aperture Spherical radio Telescope (FAST), the largest single-dish telescope in the world. Due to the 270–1620 MHz wide frequency coverage of the ultra-wideband (UWB) receiver, one can use both single-frequency and dual-frequency analyses to determine the projected velocity of the solar wind. Moreover, based on the extraordinary sensitivity owing to the large collecting surface area of FAST, we can observe weak IPS signals. With the advantages of both the wider frequency coverage and high sensitivity, and also with our radio frequency interference (RFI) mitigation strategy and an optimized model-fitting method, in this paper we analyse the fitting confidence intervals of the solar wind velocity and present some preliminary results achieved using FAST, which point to the current FAST system being highly capable of carrying out observations of IPS.
The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the eBOSS emission line galaxy sample
Authors: Alam Shadab , de Mattia Arnaud , Tamone Amélie , Ávila S , Peacock John A , Gonzalez-Perez V , Smith Alex , Raichoor Anand , Ross Ashley J , Bautista Julian E , Burtin Etienne , Comparat Johan , Dawson Kyle S , du Mas des Bourboux Hélion , Escoffier Stéphanie , Gil-Marín Héctor , Habib Salman , Heitmann Katrin , Hou Jiamin , Mohammad Faizan G , Mueller Eva-Maria , Neveux Richard , Paviot Romain , Percival Will J , Rossi Graziano , Ruhlmann-Kleider Vanina , Tojeiro Rita , Vargas Magaña Mariana , Zhao Cheng , Zhao Gong-Bo
Published: April 2021

Cosmological growth can be measured in the redshift space clustering of galaxies targeted by spectroscopic surveys. Accurate prediction of clustering of galaxies will require understanding galaxy physics, which is a very hard and highly non-linear problem. Approximate models of redshift space distortion (RSD) take a perturbative approach to solve the evolution of dark matter and galaxies in the universe. In this paper, we focus on extended Baryon Oscillation Spectroscopic (eBOSS) emission line galaxies (ELGs) that live in intermediate mass haloes. We create a series of mock catalogues using haloes from the Multidark and outer rim dark matter only N-body simulations. Our mock catalogues include various effects inspired by baryonic physics such as assembly bias and the characteristics of satellite galaxies kinematics, dynamics, and statistics deviating from dark matter particles. We analyse these mocks using the TNS RSD model in Fourier space and the convolution Lagrangian perturbation theory (CLPT) in configuration space. We conclude that these two RSD models provide an unbiased measurement of RSD within the statistical error of our mocks. We obtain the conservative theoretical systematic uncertainty of $3.3{{\ \rm per\ cent}}$, $1.8{{\ \rm per\ cent}}$, and $1.5{{\ \rm per\ cent}}$ in fσ8, α∥, and α⊥, respectively, for the TNS and CLPT models. We note that the estimated theoretical systematic error is an order of magnitude smaller than the statistical error of the eBOSS ELG sample and hence are negligible for the purpose of the current eBOSS ELG analysis.
Population synthesis of accreting white dwarfs: rates and evolutionary pathways of H and He novae
Authors: Kemp Alex J , Karakas Amanda I , Casey Andrew R , Izzard Robert G , Ruiter Ashley J , Agrawal Poojan , Broekgaarden Floor S , Temmink Karel D
Published: April 2021

Novae are some of the most commonly detected optical transients and have the potential to provide valuable information about binary evolution. Binary population synthesis codes have emerged as the most effective tool for modelling populations of binary systems, but such codes have traditionally employed greatly simplified nova physics, precluding detailed study. In this work, we implement a model treating H and He novae as individual events into the binary population synthesis code binary_c. This treatment of novae represents a significant improvement on the ‘averaging’ treatment currently employed in modern population synthesis codes. We discuss the evolutionary pathways leading to these phenomena and present nova event rates and distributions of several important physical parameters. Most novae are produced on massive white dwarfs, with approximately 70 and 55 per cent of nova events occurring on O/Ne white dwarfs for H and He novae, respectively. Only 15 per cent of H-nova systems undergo a common-envelope phase, but these systems are responsible for the majority of H nova events. All He-accreting He-nova systems are considered post-common-envelope systems, and almost all will merge with their donor star in a gravitational-wave-driven inspiral. We estimate the current annual rate of novae in M31 (Andromeda) to be approximately 41 ± 4 for H novae, underpredicting the current observational estimate of $65^{+15}_{-16}$, and 0.14 ± 0.015 for He novae. When varying common-envelope parameters, the H nova rate varies between 20 and 80 events per year.
Trips-Viz: an environment for the analysis of public and user-generated ribosome profiling data
Authors: Kiniry Stephen J , Judge Ciara E , Michel Audrey M , Baranov Pavel V
Published: April 2021

Trips-Viz (https://trips.ucc.ie/) is an interactive platform for the analysis and visualization of ribosome profiling (Ribo-Seq) and shotgun RNA sequencing (RNA-seq) data. This includes publicly available and user generated data, hence Trips-Viz can be classified as a database and as a server. As a database it provides access to many processed Ribo-Seq and RNA-seq data aligned to reference transcriptomes which has been expanded considerably since its inception. Here, we focus on the server functionality of Trips-viz which also has been greatly improved. Trips-viz now enables visualisation of proteomics data from a large number of processed mass spectrometry datasets. It can be used to support translation inferred from Ribo-Seq data. Users are now able to upload a custom reference transcriptome as well as data types other than Ribo-Seq/RNA-Seq. Incorporating custom data has been streamlined with RiboGalaxy (https://ribogalaxy.ucc.ie/) integration. The other new functionality is the rapid detection of translated open reading frames (ORFs) through a simple easy to use interface. The analysis of differential expression has been also improved via integration of DESeq2 and Anota2seq in addition to a number of other improvements of existing Trips-viz features.
Human methylome variation across Infinium 450K data on the Gene Expression Omnibus
Authors: Maden Sean K , Thompson Reid F , Hansen Kasper D , Nellore Abhinav
Published: April 2021

While DNA methylation (DNAm) is the most-studied epigenetic mark, few recent studies probe the breadth of publicly available DNAm array samples. We collectively analyzed 35 360 Illumina Infinium HumanMethylation450K DNAm array samples published on the Gene Expression Omnibus. We learned a controlled vocabulary of sample labels by applying regular expressions to metadata and used existing models to predict various sample properties including epigenetic age. We found approximately two-thirds of samples were from blood, one-quarter were from brain and one-third were from cancer patients. About 19% of samples failed at least one of Illumina’s 17 prescribed quality assessments; signal distributions across samples suggest modifying manufacturer-recommended thresholds for failure would make these assessments more informative. We further analyzed DNAm variances in seven tissues (adipose, nasal, blood, brain, buccal, sperm and liver) and characterized specific probes distinguishing them. Finally, we compiled DNAm array data and metadata, including our learned and predicted sample labels, into database files accessible via the recountmethylation R/Bioconductor companion package. Its vignettes walk the user through some analyses contained in this paper.
Street Music
Authors: Watt Paul , Bacchieri Daniel
Published: April 2021

For centuries, street musicians, or buskers, have been plying their trade the world over. However, the study of street music and musicians is an emerging field of research. It is richly interdisciplinary and reaches into many fields, including anthropology, art history, cultural studies, ethnomusicology, human geography, law and legal studies, marketing, and musicology, as well as tourism and urban studies. The topics on which scholars write largely include noise and regulation, protest, aesthetics of space, and studies of street musicians in particular cities and countries on every continent. The genres of music include street cries and brass bands, along with studies of solo instruments such as the harp, violin, voice, and accordion. The literature on street music can be categorized into three overlapping areas: historical, ethnographical, and philosophical and social. Historical studies are concentrated on street cries and street singing. Ethnographical studies are evident in a range of historical studies but also in contemporary accounts of artists from New York to Moscow and Rio de Janeiro to Melbourne. Encounters with buskers provide not only insight into the reasons they perform, but also the repertory they play and the influence of audiences and technology on their performance. Where and how musicians perform also tell us about the precarious place street musicians occupy in the cultural economies of place, especially in relation to the use of digital culture and e-commerce as a means of making money and publicity. Philosophical and social inquiry asks questions about the nature of the space street music occupies; the ways in which it is and owned, shared, or a contested space; and the psychology of creativity in the moment of performance for both musician and audience. At the heart of much of the literature on street music is the way street sound and music has been captured over the centuries. Early modern studies rely on texts—and textual analyses—to speculate on the style or mode of singing that street criers and performers used to disseminate their messages or to perform. Studies from the late 18th century rely on artworks such as woodblocks, engravings, etchings, and oil paintings to depict the sound. In the 19th century, musical transcriptions begin to appear as a way to approximate the sound of the street (usually sounds created by solo performers), but today transcription is less of a requirement. Video-recording and other forms of digital imaging are capturing the sounds and music of street musicians and their sometimes international careers. Some studies adopt theoretical approaches drawing on the work of such writers as Michel de Certeau, Erving Goffman, Henri Lefebvre, Jacques Attali, and Richard Florida.
The Hijaz and International Law
Authors: Dahlan Malik
Published: April 2021

The Hashemite Kingdom of Hijaz attracted little notice in the Western international legal history during its brief lifetime, and has not been much covered in the historical literature since. However, the Hijazi state is critical for international law because it stands at the intersection of Arab self-determination and Islamic statehood. Its birth in 1916 was, understandably perhaps, overshadowed by the military significance of the Arab Revolt against the Ottomans, and the role played in it by Colonel T.E. Lawrence. Its demise, formally declared in 1932 but inevitable after the Saudi invasion of 1924–1925, was met by silence from the members of the League of Nations despite the fact The Hijaz was one of its founding members. This neglect of the Hijazi state is unfortunate for a number of reasons. Firstly, it was the earliest attempt at Arab statehood in modern international legal history, the first ethnocentric expression of Arab self-determination to be recognized by the European powers after the Great War and, as home to the holy cities of Mecca and Medina, it had significance for Islamic governance that is disproportionate to its economic or geopolitical value. Secondly, it presents a test for one of the most fiercely contested areas of international law: how to understand and apply national self-determination to the formation and recognition of states. In this case, the claim for self-determination is bound up with the ethnocentric awakening of Arabs, the struggle over the political and institutional forms that a collectivity should take, and what balance could be struck between Western, Westphalian views of the state and Islamic governance traditions and principles. Thirdly, it provided an early example of how small states would fare in the new international order, and the extent to which they could expect great powers to abide by international law, as it emerged from the Great War. As it turned out, Sharif Hussein’s refusal to acquiesce in the League of Nations’ mandate system, itself based on the Sykes–Picot agreement between Britain and France, coupled with his support for Arab aspirations to control Jerusalem, made the fledgling state vulnerable to imperial Realpolitik. Fourthly, the fall of The Hijaz was bound up with the fall of the Caliphate in 1924, with repercussions that are still being felt. Finally, the historical events, which did much to determine the map of the Middle East today, present a telling example of how international law functions in regions where great powers are actively competing for influence and control. This bibliography collects readings that cast light on how ideas of the nation and the state have been understood and applied, with particular reference to the Islamic collectivity, the Arabs, and The Hijaz. It is divided into two general areas. The first looks at the national aspects of self-determination and the second looks at the state as understood by international law and by Islamic jurisprudence, again with special reference to The Hijaz.