bluuebunny/crossref_metadata_2025_split huggingface dataset:
MUTAGEN SPECIFICITY IN THE INDUCTION OF CHROMOSOMAL ABERRATIONS IN SOMATIC CELLS OF DROSOPHILA MELANOGASTER
Authors: Pimpinelli S , Pignone D , Santini G , Gatti M , Olivieri G 
Published: April 2021

ABSTRACT
The distribution of chromosomal aberrations between and within chromosomes of male D. melanogaster somatic cells after treatment with UV has been analyzed.—Distribution of the breaks between chromosomes was largely nonrandom since we found a higher aberration frequency than that expected on the Y chromosome. Moreover, within the chromosomes the aberrations are clustered in the pericentromeric heterochromatic regions. The above distribution is compared with that of the breaks induced by X rays and methyl-methane-sulphonate (MMS) which were distributed in a different pattern.
INFLUENCE OF GENE DUPLICATION AND X-INACTIVATION ON MOUSE MITOCHONDRIAL MALIC ENZYME ACTIVITY AND ELECTROPHORETIC PATTERNS
Authors: Eicher Eva M , Coleman Douglas L 
Published: April 2021

ABSTRACT
We have investigated, with and without the influence of X-inactivation, the relationship between autosomal gene-dosage and gene-product in a mammalian system, the mouse. The gene was mitochondrial malic enzyme (Mod-2), shown to lie on Chromosome 7 between the albino (c) and shaker-1 (sh-1) loci, and the enzyme was its product, mitochondrial malic enzyme (MOD-2). Gene duplication, with and without the influence of X-inactivation, was achieved using a translocation that involves the insertion of a portion of Chr 7, including Mod-2, into the X, T(X;7)1Ct. A 1:1 relationship for Mod-2 dosage and MOD-2 activity was found in heart mitochondria. Evidence of X-inactivation of Mod-2 was noted in heart and kidney preparations from females carrying a Mod-2 duplication (one copy of Mod-2 in the X and two copies of Mod-2 on Chr 7). We conclude that the expression of an autosomal locus attached to X-chromatin depends upon whether the translocation is in a balanced or unbalanced state.
IDENTIFICATION OF A MAJOR LOCUS CONTRIBUTING TO ERYTHROCYTE 2,3-DIPHOSPHOGLYCERATE VARIABILITY IN HOODED (LONG-EVANS) RATS
Authors: Noble N A , Brewer G J 
Published: April 2021

ABSTRACT
The erythrocyte glycolytic intermediate 2,3-diphosphoglycerate (DPG) and adenosine triphosphate (ATP) play an important role in oxygen transport and delivery by binding to hemoglobin (Hb) and reducing its affinity for oxygen. Considerable quantitative variability in the levels of DPG and ATP exists in human populations and in a population of hooded (Long-Evans) rats we have studied. This paper presents the results of studies on the genetic component of DPG-level variation in an outbred population of hooded rats. Beginning with about 100 rats, a two-way selection experiment was initiated. Pairs of rats with the highest DPG levels were mated to produce a High-DPG rat strain and animals with the lowest DPG levels were mated to produce a Low-DPG strain. Mean DPG levels responded rapidly to selection and, from generation 3 on, the differences between strain means were highly significant. Ten High-DPG strain rats were intercrossed with 10 Low-DPG strain rats of generation 10 to produce an F1 generation in which the DPG levels were almost as high as those of High-DPG animals. This indicates partial dominance of High-DPG alleles. The F2 DPG-level distribution showed two distinct subpopulations. The high DPG subpopulation contained three times as many animals as the low DPG subpopulation. From these results and the statistical analyses performed, it was concluded that the DPG differences between strains were due to an allelic difference at one major locus, the allele carried by the High-DPG strain showing partial dominance over the allele carried by the Low-DPG strain. It appears that this locus may also effect ATP levels to a large extent and is polymorphic in hooded rat populations. Identification of this locus gives us a useful tool for studies of the physiological effects of DPG variability, as well as providing an example of a major gene effect in a quantitatively varying trait.
MICROGEOGRAPHIC DIFFERENTIATION OF CHROMOSOMAL AND ENZYME POLYMORPHISMS IN DROSOPHILA PERSIMILIS
Authors: Taylor Charles E , Powell Jeffrey R 
Published: April 2021

ABSTRACT
We studied microgeographic and temporal genetic differentiation in natural populations of Drosophila persimilis with respect to chromosome inversion and enzyme polymorphisms. Both inversion frequencies and allozyme frequencies varied significantly over short distances. Neither differed significantly between morning and evening collections. Because several studies of the dispersal behavior of this species have been performed, we attempt to fit the observed data to mathematical models which relate dispersion to random genetic drift and to spatially varying selection coefficients. We conclude that the observations are due at least partly to behavioral differences among genotypes. i.e., habitat preferences. These results have implications for genetic load theory and models of selection in heterogeneous environments.
FURTHER STUDIES ON GENE POLYMORPHISM IN THE MAINBODY AND GEOGRAPHICALLY ISOLATED POPULATIONS OF DROSOPHILA PSEUDOOBSCURA
Authors: Prakash Satya 
Published: April 2021

ABSTRACT
We have examined polymorphism at 22 additional loci in the populations from the mainbody of Drosophila pseudoobscura and an isolated population from Bogotá, Colombia, which also shows partial reproductive isolation from mainbody populations. These studies extend our previous observations of reduced gene polymorphism and apparent lack of unique allele in the Bogotá population.
CENTROMERIC EFFECT ON THE DEGREE OF NONRANDOM DISJUNCTION IN THE FEMALE DROSOPHILA MELANOGASTER
Authors: Mark Hon Fong Louie , Zimmering Stanley 
Published: April 2021

ABSTRACT
From crosses of females possessing a heteromorphic X-chromosome bivalent, FR1/+, the shorter crossover products were recovered on the average more frequently than the longer reciprocals as predicted by Novitski's (1951) hypothesis of nonrandom disjunction (NRD). The present study stemmed from an unexpected result of these crosses. Evidence for a centromeric effect on NRD was obtained, suggested by a negative correlation between the degree of NRD, c, and the distance between the region of exchange and the centromere as inferred from SET's (single exchange tetrads). Studies on sex chromosome systems other than FR1 confirmed these results. An analogous centromeric effect on preferential segregation had been clearly demonstrated in maize (Kikudome 1958, 1959; Rhoades and Dempsey 1966). However, prior to the present investigation, no such effect of the centromere on NRD in Drosophila had been described, although reanalysis of part of the data of Novitski (1951) and Novitski and Sandler (1956) suggests some evidence of a seriation of increasing c values extending from the most distal region of the chromosome toward the centromere. A suggestion that the effect in Drosophila may be related in some way to the time required for chiasma terminalization, i.e., those terminalizing earlier (distally located crossovers) permitting more random disjunction of the chromatids from the asymmetric dyad and those terminalizing later, progressively less random, is considered and rejected since in general the expected pattern of c values for the various double exchange tetrads (DET's) is inconsistent with that prediction and provides evidence suggesting the possibility of reversals, in part, of c values obtained for SET's.
EFFECTS OF SELFING ON SELECTION FOR RECOMBINATION
Authors: Charlesworth D , Charlesworth B , Strobeck C 
Published: April 2021

ABSTRACT
This paper describes the results of computer simulations of selection on a locus which affects the rate of recombination between a pair of loci under selection. Four different models of selection for increased recombination were examined. In our first two models, which involve hitchhiking effects, increased levels of selfing can lead to increased selection for recombination, but need not always do so. With two models of selection for recombination caused by fluctuations in the environment, increased selfing always led to increased selection for recombination. Constant-environment models with nonadditive fitnesses at the two selected loci were also studied. Selfing increased selection for modifiers decreasing recombination, compared with random-mating populations in which indeed there might be no selection for decreased recombination. At high levels of selfing, the intensity of selection against recombination was sometimes found to weaken again.
MUTATOR MUTATIONS IN BACTERIOPHAGE T4 GENE 42 (dHMC HYDROXYMETHYLASE)
Authors: Williams Warren E , Drake John W 
Published: April 2021

ABSTRACT
Temperature-sensitive mutations of bacteriophage T4 gene 42 produce diverse effects upon spontaneous mutation rates. G:C → A:T transition rates are increased, often strongly; frameshift mutation rates are weakly increased; A:T → G:C transition rates (and perhaps also A:T → Py:Pu transversion rates) are decreased; and one G:C → Py:Pu transversion rate is also decreased. These results, together with certain interactions between gene-42 mutator effects and both base analogue mutagenesis and the viral error-prone repair system, suggest that the dHMC hydroxymethylase coded by gene 42 affects mutation rates in a more complex manner than by the simple regulation of the concentration of the DNA precursor dHMCTP.
PHYLOGENIES CONSTRAINED BY THE CROSSOVER PROCESS AS ILLUSTRATED BY HUMAN HEMOGLOBINS AND A THIRTEEN-CYCLE, ELEVEN-AMINO-ACID REPEAT IN HUMAN APOLIPOPROTEIN A-I
Authors: Fitch Walter M 
Published: April 2021

ABSTRACT
Examination of human apolipoprotein A-I revealed a segment of eleven amino acids that repeated itself 13 times in succession without any additional intervening amino acids between the beginning of the repeats (amino acid 93) and their end at the carboxyl terminus of the sequence. The segments are not identical, but the pattern of their physical and chemical properties is highly conserved. The pattern is shown to be suitable to the formation of alpha helices with an amphipathic character consistent with the formation of a micellar structure, a process entirely appropriate to the protein's known function in the blood stream as a lipid carrier. The simplest hypothesis to account for repeated segments is a series of unequal crossovers. But such a series implies that some segments are more closely related to each other than they are to others, that is, they have a "phylogenetic" relationship. It is shown that only a small fraction of all possible phylogenies are consistent with a set of segments arising by simple unequal crossing over. Nevertheless, it is shown that the apolipoprotein A-I segments are readily interpretable as the result of simple unequal crossing over. Moreover, the crossover constraint applies with as much force to segments larger than a gene as to segments within a gene, and this is shown to require that the human gamma (Gly) hemoglobin gene lie to the left, rather than to the right, of the other non-alpha human hemoglobin genes, a conclusion for which there is no direct genetic evidence currently available.
A MODEL OF FUNCTIONAL EPISTASIS AND LINKAGE DISEQUILIBRIUM IN POPULATIONS WITH OVERLAPPING GENERATIONS
Authors: Giesel James T 
Published: April 2021

ABSTRACT
A model of functional epistasis is proposed in which it is assumed that coupling and repulsion genotypes differ in metabolic efficiency and thus in development time and net fecundity. The implications of this model are investigated for iteroparous populations with fluctuating rates of increase. It is found that the fluctuations in rate of increase can lead to large fluctuations in gamete frequency and D, the coefficient of linkage disequilibrium, but that D will almost always have a value of zero at some point during the populations' demographic cycle. Some of the model populations would be expected to be in a state of linkage disequilibrium only fleetingly: others would exhibit D-cycles interpretable as random fluctuation. Implications of the model for interpretations of existing data on linkage disequilibrium among enzyme loci in Drosophila are discussed.
Chromatin conformation capture (Hi-C) sequencing of patient-derived xenografts: analysis guidelines
Authors: Dozmorov Mikhail G , Tyc Katarzyna M , Sheffield Nathan C , Boyd David C , Olex Amy L , Reed Jason , Harrell J Chuck 
Published: April 2021

Abstract

Background
Sequencing of patient-derived xenograft (PDX) mouse models allows investigation of the molecular mechanisms of human tumor samples engrafted in a mouse host. Thus, both human and mouse genetic material is sequenced. Several methods have been developed to remove mouse sequencing reads from RNA-seq or exome sequencing PDX data and improve the downstream signal. However, for more recent chromatin conformation capture technologies (Hi-C), the effect of mouse reads remains undefined.

Results
We evaluated the effect of mouse read removal on the quality of Hi-C data using in silico created PDX Hi-C data with 10% and 30% mouse reads. Additionally, we generated 2 experimental PDX Hi-C datasets using different library preparation strategies. We evaluated 3 alignment strategies (Direct, Xenome, Combined) and 3 pipelines (Juicer, HiC-Pro, HiCExplorer) on Hi-C data quality.

Conclusions
Removal of mouse reads had little-to-no effect on data quality as compared with the results obtained with the Direct alignment strategy. Juicer extracted more valid chromatin interactions for Hi-C matrices, regardless of the mouse read removal strategy. However, the pipeline effect was minimal, while the library preparation strategy had the largest effect on all quality metrics. Together, our study presents comprehensive guidelines on PDX Hi-C data processing.
Deep-learning assisted regularized elastic full waveform inversion using the velocity distribution information from wells
Authors: Li Yuanyuan , Alkhalifah Tariq , Zhang Zhendong 
Published: April 2021

SUMMARYElastic full waveform inversion (EFWI) can, theoretically, give high-resolution estimates of the subsurface. However, in practice, the resolution and illumination of EFWI are limited by the bandwidth and aperture of seismic data. The often-present wells in developed fields as well as some exploratory regions can provide complementary information of the target area. We, thus, introduce a regularization technique, which combines the surface seismic and well log data, to help improve the resolution of EFWI. We use deep neural networks to learn the statistical relations between some selected features of the inverted model and the facies interpreted from well logs. The selected features are the means and variances of the inverted velocities defined within Gaussian windows. Using multiple fully connected layers, we train our neural networks to identify the relation between the means and variances at the well location and those from the inverted model. The network is used to map the means and variances extracted from the well to the whole model domain. We then perform another EFWI in which we fit the predicted data to the observed ones as well as fit the model over a Gaussian window to the predicted means and variances. The tests on synthetic and real seismic data demonstrate that the proposed method can effectively improve the resolution and illumination of deep-buried reservoirs, which often encounter poor illumination from seismic data.
Long-term outcomes after the paediatric Ross and Ross-Konno procedures
Authors: Schlein Johanna , Ebner Barbara Elisabeth , Geiger Ralf , Simon Paul , Wollenek Gregor , Moritz Anton , Gamillscheg Andreas , Base Eva , Laufer Günther , Zimpfer Daniel 
Published: April 2021

Abstract

OBJECTIVES
The Ross procedure is an attractive option for the management of aortic valve disease in paediatric patients. We reviewed our experience with the paediatric Ross procedure to determine survival and freedom from reoperation in the third decade after surgery.

METHODS
We reviewed the data of 124 paediatric patients [71% male, median age at time of surgery 11.1 years (interquartile range 6–14.8 years); 63.7% bicuspid aortic valve], who underwent the Ross procedure at 2 tertiary centres from April 1991 to April 2020. The Ross-Konno procedures were performed on 14 (11.3%) patients. Deaths were cross-checked with the national health insurance database, and survival status was available for 96.8% of the patients. The median follow-up time was 12.1 years (interquartile range 3–18 years).

RESULTS
There were 3 early and 6 late deaths. All early deaths occurred in patients aged &lt;1 year at the time of surgery. The 25-year survival was 90.3%. Actuarial freedom from reoperation (linearized rates in parentheses) was as follows: Autograft reoperation was 90.8% (0.48%/patient-year) and right ventricular outflow tract (RVOT) reoperation was 67% (2.07%/patient year) at 25 years. The univariable Cox-proportional hazard analysis revealed younger age at time of surgery (P &lt; 0.001), smaller implanted valve size (P &lt; 0.001) and the use of a xenograft rather than a homograft (P &lt; 0.001) as predictors of RVOT reoperation. At multivariable Cox-proportional hazard analysis, only age was an independent risk factor for RVOT reoperation (P = 0.041).

CONCLUSIONS
The Ross and the Ross-Konno procedures are associated with good outcomes in paediatric patients. Reoperation of the RVOT is frequent and associated with younger age.
Clinical Utility of an Exoskeleton Robot Using Three-Dimensional Scanner Modeling in Burn Patient: A Case Report
Authors: Joo So Young , Lee Seung Yeol , Cho Yoon Soo , Yi Sangho , Seo Cheong Hoon 
Published: April 2021

Abstract
Hands are the part of the body that are most commonly involved in burns, and the main complications are finger joint contractures and nerve injuries. Hypertrophic scarring cannot be avoided despite early management of acute hand burn injuries, and some patients may need the application of an exoskeleton robot to restore hand function. To do this, it is essential to individualize the customization of the robot for each patient. Three-dimensional (3D) technology, which is widely used in the field of implants, anatomical models, and tissue fabrication, makes this goal achievable. Therefore, this report is a study on the usefulness of an exoskeleton robot using 3D technology for patients who lost bilateral hand function due to burn injury. Our subject was a 45-year-old man with upper limb dysfunction of 560 days after a flame and chemical burn injury, with resultant impairment of manual physical abilities. After wearing an exoskeleton robot made using 3D printing technology, he could handle objects effectively and satisfactorily. This innovative approach provided considerable advantages in terms of customization of size and reduction in manufacturing time and costs, thereby showing great potential for use in patients with hand dysfunction after burn injury.
Pathological progress of traumatic femur head necrosis after femoral neck fracture in children and adolescents: a case series study
Authors: Yang Fan , Zhuang Zhikun , Tu Yonggang , Hong Zhinan , Pang Fengxiang , He Wei , Wei Qiushi , Li Ziqi 
Published: April 2021

Abstract
The pathological progression and prognosis of traumatic femur head necrosis (TFHN) after femoral neck fracture (FNF) in children and adolescent is relatively unknown and has never been specifically characterized. As we speculated, the prognosis in such population would be poor and characterized as the high risk of femoral head collapse, hip deformity and degeneration in a short term. This retrospective case series enrolled 64 children and adolescent with TFHN who treated with observational treatment from 2000.1 to 2018.1. The primary outcomes, the progression of femoral head collapse, hip deformity (Stulberg classification) and hip degeneration (Tönnis grade), and their prognostic factors were analysed. Sixty-four patients with a mean age of 13 years (6–16 years) were included. A total of 28 hips (44%) showed unsatisfactory outcome and 25 (39%) hips collapsed progressively during a mean follow-up of 48 months (24–203 months). Finally, 38 hips (59%) experienced hip deformity, 20 of them were Class IV/V. Thirty-four hips (53%) generally progressed to osteoarthritis, 14 of them were classified as Grades II/III. The location of the lesion and the presence of subluxation were found to be related to progression of collapse; however, the presence of subluxation was the only independent risk factor of severe hip deformity and degeneration. TFHN in children and adolescent is a rapidly progressing disease with a poor prognosis characterized by a high risk of femoral head collapse progression. If the subluxation emerged, collapsed cases showed increasingly tendency towards hip deformity and degeneration.
Expect the Unexpected—First Case of Congenital Rubella Syndrome in Israel in 20 Years: A Case Report
Authors: Molad Michal , Gover Ayala , Ephros Moshe , Lavie-Nevo Karen , Waisman Dan , Levin Tal , Kanaaneh Yara , Indenbaum Victoria 
Published: April 2021

Abstract
Congenital rubella syndrome (CRS) is a devastating condition associated with significant morbidity. Due to universal vaccination programs, it is currently a rare condition, especially in developed countries. We report an infant born in Israel to a foreign worker from the Philippines who presented with a blueberry muffin rash immediately after birth. Initial workup revealed sonographic brain anomalies, abnormal hearing tests, and a patent ductus arteriosus. CRS was subsequently confirmed by laboratory diagnosis. Rubella virus genotype 1E was detected in the infant’s nasopharyngeal swab and urine samples. This was the first case of CRS in Israel in 20 years, emphasizing the need to “think outside the box” when dealing with infants of mothers who are foreign workers, refugees, or visitors of foreign relatives, in which rubella immune status is unknown. Additionally, public health authorities should consider the routine assessment of rubella immunity status of foreign workers in order to avoid such tragic, preventable diseases.
We present a case of congenital rubella syndrome – rarely seen in developed countries. This emphasis the need to “think out of the box” when dealing with infants of mothers who come from countries in which the vaccination program is not well established.
Modified laparoscopic toupet fundoplication with fundo-phrenico-pexy
Authors: Schriener Thomas , Berkhoff Stefan , Ezzy Mohsen , Kraus Thomas W , Elshafei Moustafa 
Published: April 2021

Abstract
This article presents an alternative technique to the common Toupet fundoplication. It is a modern combination of the standard Toupet procedure and an additional fundophrenicopexie of the gastric wrap. In 1963 Toupet first described his technique of a fundoplication for reflux surgery. Over the past years this procedure has been modified and expanded many times. We have learned that the short gastric vessels need to be divided to get the wrap closer and easier around the esophagus. Furthermore, it is likely necessary to perform a balanced hiatoplasty to avoid slippage of the wrap. Our procedure is a modification of the standard Toupet fundoplication, but is extended by fixing the wrap to the anterior wall of the diaphragm. We consider our modification successful and safe in treating gastroesophageal reflux disease in patients with type I/II hiatal hernia and prevent postoperative complications such as dysphagia or slippage of the wrap.