bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interfacial interaction and prenucleation at liquid-Al/γ-Al2O3{1 1 1} interfaces
Authors: Fang Changming , Yasmin Sultana , Fan Zhongyun 
Published: January 2021

Abstract
Alumina (α- and γ-Al2O3) particles are formed in liquid Al-Mg alloys during the liquid dealing and cast processes. These native oxide particles have non-trivial influences on the microstructures and properties of the solidified parts, and may act as potential heterogenous nucleation sites during solidification. At present there is still a lack of understanding about the interaction and atomic arrangements at the interfaces between liquid-Al and γ-Al2O3 substrates. Here we investigate the liquid-Al/γ-Al2O3{1 1 1} interfaces by means of ab initio molecular dynamics simulations and electronic structure calculations. We found that the interfacial interaction at the interfaces leads to formation of an ordered terminating Al layer. This newly formed terminating Al layer is positively charged and chemically bonded to the substrate and thus, becomes part of the substrate. Analysis showed that the terminating Al layer contains vacancies and displacements, being atomically rough. The newly-formed Al layer is also structurally coupled with the substrates. These γ-Al2O3 particles are weak templates for nearby liquid to nucleate. The present study sheds some light on the role of alumina particles in grain refinement of Al-based alloys during solidification processing.
Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial
Authors: Lin Yu-Shiuan , Weibel Janine , Landolt Hans-Peter , Santini Francesco , Meyer Martin , Brunmair Julia , Meier-Menches Samuel M , Gerner Christopher , Borgwardt Stefan , Cajochen Christian , Reichert Carolin 
Published: January 2021

Abstract
Caffeine is commonly used to combat high sleep pressure on a daily basis. However, interference with sleep–wake regulation could disturb neural homeostasis and insufficient sleep could lead to alterations in human gray matter. Hence, in this double-blind, randomized, cross-over study, we examined the impact of 10-day caffeine (3 × 150 mg/day) on human gray matter volumes (GMVs) and cerebral blood flow (CBF) by fMRI MP-RAGE and arterial spin-labeling sequences in 20 habitual caffeine consumers, compared with 10-day placebo (3 × 150 mg/day). Sleep pressure was quantified by electroencephalographic slow-wave activity (SWA) in the previous nighttime sleep. Nonparametric voxel-based analyses revealed a significant reduction in GMV in the medial temporal lobe (mTL) after 10 days of caffeine intake compared with 10 days of placebo, voxel-wisely adjusted for CBF considering the decreased perfusion after caffeine intake compared with placebo. Larger GMV reductions were associated with higher individual concentrations of caffeine and paraxanthine. Sleep SWA was, however, neither different between conditions nor associated with caffeine-induced GMV reductions. Therefore, the data do not suggest a link between sleep depth during daily caffeine intake and changes in brain morphology. In conclusion, daily caffeine intake might induce neural plasticity in the mTL depending on individual metabolic processes.
Evolution of Cefiderocol Non-Susceptibility inPseudomonas aeruginosain a Patient Without Previous Exposure to the Antibiotic
Authors: Streling Ana Paula , Al Obaidi Mohanad M , Lainhart William D , Zangeneh Tirdad , Khan Ayesha , Dinh An Q , Hanson Blake , Arias Cesar A , Miller William R 
Published: January 2021

AbstractWe report the emergence of non-susceptibility to cefiderocol from a subpopulation of Pseudomonas aeruginosa recovered from a patient without history of cefiderocol exposure. Whole genome sequencing identified mutations in major iron transport pathways previously associated with cefiderocol uptake. Susceptibility testing should be performed before therapy with siderophore cephalosporins.
Long-term outcome after the arterial switch operation: 43 years of experience
Authors: van der Palen Roel L F , Blom Nico A , Kuipers Irene M , Rammeloo Lukas A J , Jongbloed Monique R M , Konings Thelma C , Bouma Berto J , Koolbergen David R , Hazekamp Mark G 
Published: January 2021

Abstract

OBJECTIVES
The objective of this study was to assess our 43-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) by analysing cardiac outcome measures (hospital and late mortality, reoperations and catheter interventions, significant coronary artery obstruction) and to identify risk factors for reoperation and catheter interventions.

METHODS
A total of 490 patients who underwent ASO for TGA from 1977 to 2020 were included in this retrospective, single-centre study. Data on reoperation and catheter intervention of hospital survivors were estimated by the Kaplan–Meier method and compared using a long-rank test. Risk factors for reoperation and/or catheter intervention were assessed by multivariate Cox regression analysis.

RESULTS
Hospital mortality occurred in 43 patients (8.8%), late death in 12 patients (2.9%) and 43 patients were lost to follow-up. Median follow-up time of 413 hospital survivors was 15.6 (interquartile range 7.0–22.4) years. Reoperations were performed in 83 patients (117 reoperations). Neoaortic valve regurgitation with root dilatation was the second most common indication for reoperation (15/83 patients, 18.1%) after right ventricular outflow tract obstruction (50/83 patients, 60.2%). Risk factors for any reoperation on multivariable analysis were: TGA morphological subtype [TGA with ventricular septal defect: hazard ratio (HR) = 1.99, 95% confidence interval (CI) 1.18–3.36; P = 0.010 and Taussig-Bing: HR = 2.17, 95% CI 1.02–4.64; P = 0.045], aortic arch repair associated with ASO (HR = 3.03, 95% CI 1.62–5.69; P = 0.001) and a non-usual coronary artery anatomy (HR = 2.41, 95% CI 1.45–4.00; P = 0.001). One hundred and one catheter interventions were performed in 54 patients, usually for relief of supravalvular pulmonary stenosis (44/54 patients, 81.5%) or arch obstruction (10/54 patients, 18.5%). Main risk factor for catheter intervention on multivariable analysis was aortic arch repair associated with ASO (HR = 2.95, 95% CI 1.37–6.36; P = 0.006). Significant coronary artery stenosis was relatively uncommon (9/413 patients, 2.2%) but may be underrepresented.

CONCLUSIONS
Patients after ASO typically have good long-term clinical outcomes but reoperations and interventions remain necessary in some patients. Neoaortic valve regurgitation with root dilatation is the second most common indication for reoperation after right ventricular outflow tract obstruction and an increasing need for neoaortic valve and root redo surgery in future is to be expected.
The relationship between blood pressure and risk of atrial fibrillation: a Mendelian randomization study
Authors: Georgiopoulos Georgios , Ntritsos Georgios , Stamatelopoulos Kimon , Tsioufis Costas , Aimo Alberto , Masi Stefano , Evangelou Evangelos 
Published: January 2021

Abstract

Aims
Observational studies suggest elevated blood pressure (BP) as the leading risk factor for incident atrial fibrillation (AF), but whether this relationship is causal remains unknown. In this study, we used Mendelian randomization (MR) to investigate the potential causal association of BP levels with the risk of developing AF.

Methods and results
Genetic variants associated with the BP traits were retrieved from the International Consortium of Blood Pressure-Genome Wide Association Studies (N = 299 024). From 901 reported variants, 894 were assessed in a dedicated Genome-Wide Association Study of AF genetics, including &gt;1 000 000 subjects of European ancestry. We used two-sample MR analyses to examine the potential causal association of systolic BP (SBP) and diastolic BP (DBP) as well as of pulse pressure (PP) with AF. MR analysis identified a potentially causal association between AF and SBP [odds ratio (OR): 1.018 per 1 mmHg increase, 95% confidence interval (CI): 1.012–1.024, P &lt; 0.001], DBP (OR: 1.026, 95% CI: 1.016–1.035, P &lt; 0.001), and PP (OR: 1.014, 95% CI: 1.001–1.028, P = 0.033). These findings were robust in sensitivity analyses, including the MR-Egger method and the MR pleiotropy residual sum and outlier test (MR-PRESSO). The causal relationship of BP and AF did not change when single-nucleotide polymorphisms associated with possible confounders (i.e. coronary artery disease and obesity) of the causal relationship were excluded.

Conclusions
The association between increased BP levels and the risk of AF is likely causal and applies for different BP indices. Independently from other risk factors, optimal BP control might represent an important therapeutic target for AF prevention in the general population.
THE GENETIC STRUCTURE OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. XVI. EXCESS OF ADDITIVE GENETIC VARIANCE OF VIABILITY
Authors: Mukai Terumi , Nagano Shuji 
Published: January 2021

ABSTRACT
About 500 second and 500 third chromosomes were extracted, using the marked inversion technique, from the Orlando-Lake Placid, Florida, population. From the experiments using these chromosomes, the following findings were obtained: (1) The frequencies of lethal-carrying chromosomes were 0.37 in the second and 0.55 in the third chromosomes. (2) The size of the population was estimated to be effectively infinite, on the basis of the allelism rate of lethal-carrying chromosomes. (3) The detrimental and lethal loads for viability were, respectively, 0.40 and 0.45 for the second and 0.52 and 0.78 for the third chromosomes. Consequently, the detrimental to lethal load ratio is 0.90 for the second and 0.67 for the third chromosomes. (4) Lethal genes were shown to be deleterious when heterozygous. (5) The average degree of dominance for mildly deleterious genes (viability polygenes) was estimated to be nearly 0.5, although the confidence interval is large. (6) Additive (σ2 A) and dominance (σ2 D) variances of viability were estimated by using a partial diallel cross method. The results were (see PDF) and (see PDF) for the second chromosomes. (7) Environmental variances of viability were estimated. The result indicates that the heterozygotes are more homeostatic than the homozygotes. The most striking finding is that the additive variance is larger than expected on the classical hypothesis from the detrimental load. Several possible explanations for the discrepancy are offered. The most likely cause, we suggest, is genotype-environment interaction (diversifying selection) acting on viability polygenes. Overdominance is inconsistent with the low dominance variance, and frequency-dependent selection also appears unlikely as an explanation.
GENETIC ANALYSIS OF THREE DOMINANT FEMALE-STERILE MUTATIONS LOCATED ON THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Busson D , Gans M , Komitopoulou K , Masson M 
Published: January 2021

ABSTRACT
Three dominant female-sterile mutations were isolated following ethyl methanesulfonate (EMS) mutagenesis. Females heterozygous for two of these mutations show atrophy of the ovaries and produce no eggs (ovoD 1) or few eggs (ovoD 2); females heterozygous for the third mutation, ovoD 3, lay flaccid eggs. All three mutations are germ line-dependent and map to the cytological region 4D-E on the X chromosome; they represent a single allelic series. Two doses of the wild-type allele restore fertility to females carrying ovoD 3 and ovoD 2, but females carrying ovoD 1 and three doses of the wild-type allele remain sterile. The three mutations are stable in males but are capable of reversion in females; reversion of the dominant mutations is accompanied by the appearance, in the same region, of a recessive mutation causing female sterility. We discuss the utility of these mutations as markers of clones induced in the female germ line by mitotic recombination as well as the nature of the mutations.
HOMOEOSIS IN DROSOPHILA: A NEW ENHANCER OF POLYCOMB AND RELATED HOMOEOTIC MUTATIONS
Authors: Sato Takashi , Russell Michael A , Denell R E 
Published: January 2021

ABSTRACT
A new recessive lethal mutation in Drosophila melanogaster, Enhancer of Polycomb [E(Pc)], and chromosomal deficiencies lacking this locus act as dominant enhancers of the Polycomb mutant syndrome in adults. Thus, although E(Pc)/+ flies are phenotypically normal, this locus is haplo-abnormal with respect to its effect on the Polycomb phenotype. Recombinational and deficiency mapping localize the E(Pc) locus on chromosome 2 proximally and very closely linked (∼0.1 map unit) to the engrailed gene. E(Pc) enhances the expression of all Polycomb point mutations examined including that of a deficiency, indicating that this interaction does not depend on the presence of an altered Polycomb gene product. In several respects the mutations extra sex comb, lethal(4)29, and Polycomblike resemble those at the Polycomb locus. In the presence of E(Pc), recessive alleles of extra sex comb and lethal(4)29 are rendered slightly pseudodominant, and the homoeotic effects of Polycomblike heterozygotes are also enhanced. However, E(Pc) does not affect the expression of dominant mutations within the Bithorax gene complex (Cbx) or Antennapedia gene complex (AntpNs, Antp 73b, Antpscx, AntpEfW15, ScrMsc) which give homoeotic transformations resembling those of the Polycomb syndrome. Available evidence from the study of adult phenotypes suggests that mutations at E(Pc) do not result in homoeotic changes directly but instead modify the expression of a specific set of functionally related homoeotic variants.
EVIDENCE FOR DUPLICATION OF THE STRUCTURAL GENES CODING PLASTID AND CYTOSOLIC ISOZYMES OF TRIOSE PHOSPHATE ISOMERASE IN DIPLOID SPECIES OF CLARKIA
Authors: Pichersky E , Gottlieb L D 
Published: January 2021

ABSTRACT
Formal genetic analyses of the mode of inheritance of the multiple plastid and cytosolic isozymes of triose phosphate isomerase (TPI, EC 5.3.1.1) in annual diploid species of Clarkia (Onagraceae), native to California, suggest that each set of isozymes is specified by duplicate structural genes. In contrast, most diploid plant species possess one plastid and one cytosolic TPI isozyme each coded by a single locus. Linkage tests revealed that the two genes coding the plastid TPIs assort independently. Although the number of individuals sampled per species was small, the plastid isozymes were electrophoretically more variable than the cytosolic isozymes. The two gene duplications are the first reported that characterize an entire plant genus. Initial electrophoretic surveys of TPI in other genera of Onagraceae revealed that the duplication of the gene coding the plastid isozyme is apparently restricted to Clarkia, whereas that of the gene coding the cytosolic isozyme is present in most genera of the family. The separate phylogenetic distributions of the two duplications suggest that the processes that gave rise to them were unrelated.
EVOLUTIONARY RELATIONSHIP OF DNA SEQUENCES IN FINITE POPULATIONS
Authors: Tajima Fumio 
Published: January 2021

ABSTRACT
With the aim of analyzing and interpreting data on DNA polymorphism obtained by DNA sequencing or restriction enzyme technique, a mathematical theory on the expected evolutionary relationship among DNA sequences (nucleons) sampled is developed under the assumption that the evolutionary change of nucleons is determined solely by mutation and random genetic drift. The statistical property of the number of nucleotide differences between randomly chosen nucleons and that of heterozygosity or nucleon diversity is investigated using this theory. These studies indicate that the estimates of the average number of nucleotide differences and nucleon diversity have a large variance, and a large part of this variance is due to stochastic factors. Therefore, increasing sample size does not help reduce the variance significantly. The distribution of sample allele (nucleomorph) frequencies is also studied, and it is shown that a small number of samples are sufficient in order to know the distribution pattern
ISOGENIC STRAINS OF PHYCOMYCES BLAKESLEEANUS SUITABLE FOR GENETIC ANALYSIS
Authors: Alvarez M I , Eslava A P 
Published: January 2021

ABSTRACT
The progeny of crosses between wild-type strains of Phycomyces usually do not exhibit all of the expected genotypes from meiosis. By backcrossing, we have isolated a new (+) mating-type strain, A56, which is nearly isogenic with the (-) wild-type NRRL1555 commonly used in Phycomyces research. Tetrad analysis of the backcrosses shows that meiosis becomes more regular as the parental (+) and (-) strains become more isogenic. In our two-factor crosses with unlinked markers, the regularity of meiosis is measured as the percent of reciprocal ditypes plus tetratypes in the progeny. We have shown that this percentage increases from about 15% for crosses between nonisogenic parents to 90% in the eighth backcross. The results indicate that routine, reliable recombination analyses are possible in P. blakesleeanus.
GENETIC DIFFERENTIATION AMONG KARYOTYPIC FORMS OF THE BLACK RAT, RATTUS RATTUS
Authors: Baverstock P R , Adams M , Maxson L R , Yosida T H 
Published: January 2021

ABSTRACT
The black rat, Rattus rattus, consists of five karyotypic forms—2n = 42 (high C-banding); 2n = 42 (low C-banding); 2n = 40; 2n = 38; 2n = 42 Mauritius. Here, we use isozyme electrophoresis and microcomplement fixation to elucidate the genetic distance and phylogenetic relationship among each of the various karyotypic forms of R. rattus and R. norvegicus. The results show that (1) the 2n = 42 Mauritius black rat (2n = 42Mau) is genetically very similar to the 2n = 38 form, suggesting that this island population has undergone very rapid chromosomal evolution; (2) the 2n = 40 form from the highlands of Sri Lanka is genetically distinct from the 2n = 38 form from the lowlands; the genetic difference is probably insufficient, however, to prevent future introgression; (3) the level of genetic differentiation occurring between the 2n = 42 forms on the one hand and the 2n = 38, 2n = 40 and 2n = 42 Mau forms on the other support the hybrid incompatability data in suggesting that the two groups are either full species or incipient species; (4) in contrast to data from amino acid composition of transferrin and from restriction endonuclease digests of mtDNA, the present data suggest that the various karyotypic forms of R. rattus are phylogenetically more closely related to each other than any is to R. norvegicus, and that they are related by a series 2n = 42 → 2n = 40 → 2n = 38; (5) the R. rattus/R. norvegicus divergence occurred 2-8 million years ago, whereas the various chromosomal forms of R. rattus diverged over the last 4 million years.
SUPPRESSOR SYSTEMS OF SEGREGATION DISTORTER (SD) CHROMOSOMES IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER
Authors: Hiraizumi Yuichiro , Thomas Anita M 
Published: January 2021

ABSTRACT
Several natural populations of D. melanogaster were investigated for the presence (or absence) of the Segregation Distorter (SD) chromosomes and their suppressor systems. The SD chromosomes were found, at frequencies of a few percent, in two independent samples taken in different years from a Raleigh, North Carolina, population, whereas no SD chromosomes were found in samples collected from several populations in Texas. The populations in these localities were found to contain suppressor X chromosomes in high frequencies (75% or higher). They also contained relatively low frequencies of partial suppressor or insensitive second chromosomes of varying degrees, but completely insensitive second chromosomes were practically absent in all populations examined. The frequencies of suppressor X chromosomes, as well as those of the partially insensitive or suppressor second chromosomes, were the same among the populations investigated. This suggests the possibility that the development of a suppressor system of SD in a population could be independent of the presence of an SD chromosome. Segregation distortion appeared to be occurring in natural genetic backgrounds, but the degree of distortion varied among males of different genotypes. There were many instances in which the SD chromosomes showed transmission frequencies from their heterozygous male parents that were smaller than 0.6 and, in several cases, even smaller than 0.5. The presence of a recessive suppressor, or suppressors, of SD in natural populations was suggested.
NEW HYBRIDS WITH D GENOME WHEAT RELATIVES
Authors: Zhao Y H , Kimber G 
Published: January 2021

ABSTRACT
The cytology of nine new D genome hybrids involving Triticum syriacum, Triticum ventricosum, Triticum cyclindricum, Triticum juvenale, Triticum crassum, Triticum tauschii and Triticum aestivum is described. The calculation of numerical values of the relative affinity and the patterns of chromosome pairing indicate that the D genome in T. syriacum and T. juvenale may have been substantially modified and that of T. crassum somewhat modified from that of the diploid progenitor, T. tauschii.
AUTOREGULATORY FUNCTIONING OF A DROSOPHILA GENE PRODUCT THAT ESTABLISHES AND MAINTAINS THE SEXUALLY DETERMINED STATE
Authors: Cline Thomas W 
Published: January 2021

ABSTRACT
Sxl appears to head a regulatory gene hierarchy that controls Drosophila sexual dimorphism in response to the X chromosome/autosome balance. Only XXAA cells normally have Sxl + activity. It maintains both the female morphogenetic sequence and a level of X-linked dosage-compensated gene expression compatible with diplo-X cell survival. In the absence of this activity, male sexual development and dosage-compensated gene hyperactivation ensure. Loss-of-function Sxl mutations generally have female-specific lethal effects caused by upsets in dosage compensation. New female-viable Sxl mutant alleles and combinations which lack Sxl's female sex determination function, yet still provide sufficient dosage compensation function for diplo-X survival, are described here. Consequently, such mutants cause genotypic females to develop as phenotypic males. Some of these sex-transforming Sxl mutants do not require the maternally produced da + activity that is normally essential for the functioning of zygotic Sxl alleles. In this paper, products of these unusual alleles are shown to act in trans to induce the expression of zygotic Sxl + alleles that would otherwise be unable to function due to a lack of maternal da + activity. This result indicates a third function for Sxl + product: a positive autoregulatory role. Controls for the autoregulation experiments demonstrated the sex-trans-forming epigenetic effect of the da mutation for the first time in diploids. In these experiments the female-specific zygotic lethal effects that normally would have accompanied loss of maternal da + activity were suppressed by mutations known to block dosage-compensation gene hyperactivation-the autosomal, male-specific lethals. Three types of abnormal sexual phenotypes were produced in the experiments described here, each with important implications for the mechanism of sex determination: (1) a true intersex phenotype produced by one particular Sxl allele shows that Sxl + must be involved in the cellular response to the X/A balance rather than in its establishment; (2) a maternally induced, female-sterile phenotype indicates that either the process of autoregulation or the mutants used to demonstrate it are tissue specific and (3) a mosaic intersexual phenotype whose character implies that the Sxl + activity level is set early in development, both by the da +-mediated X/A balance signal and by autoregulation, and is maintained subsequently in a cell autonomous fashion, independent of the initiating X/A balance signal. Thus, this study supports the view that sex determination is truly determinative in the standard developmental sense, and that Sxl is the carrier of the sexually determined state.