bluuebunny/crossref_metadata_2025_split huggingface dataset:
MARKER DISCRIMINATION AND MUTAGEN-INDUCED ALTERATIONS IN PNEUMOCOCCAL TRANSFORMATION
Authors: Tiraby Jean-Gérard , Fox Maurice S 
Published: January 2021

ABSTRACT
Nitrous acid-induced and hydroxylamine-induced chemical alterations in transforming DNA result in the loss of biological activity and in mutagenesis. The function responsible for the discrimination between high efficiency and low efficiency markers in pneumococcal transformation, and for the elimination of a substantial fraction of spontaneously occurring mutational events, does not appear to act on integrated DNA carrying these chemical alterations. The chemical modifications result in mutations that are evident among bacteria transformed with the treated DNA. Fusidic acid-resistant mutants isolated in this way have been shown to be predominantly of the low efficiency class. We have previously reported that most mutations of spontaneous origin occurring in this locus are of the high efficiency class, and have suggested that discrimination results from the elimination of specific classes of base pair mismatches that occur as intermediates in transformation. It would appear that the base pair mismatches most effectively eliminated in the discriminating strain of pneumococcus are those of the A:C and G:T type and that the immediate product of transformation with mutagenized DNA involves intermediates that are not recognized as A:C or G:T by the discrimination system.
DOMINANCE RELATIONSHIPS BETWEEN TWO ALLELIC GENES CONTROLLING GLYCOSYLTRANSFERASES WITH DIFFERENT SUBSTRATE SPECIFICITY IN MELANDRIUM
Authors: van Brederode J , van Nigtevecht G 
Published: January 2021

ABSTRACT
Genetical analysis showed that the genes gG and gX, which control, respectively, the glucosylation and xylosylation of the 7-hydroxyl group of isovitexin in the petals of Melandrium, are alleles. In petal extracts of plants possessing the gene gX an enzyme was present which catalyzed the transfer of the xylose moiety of UDP-xylose to the 7-hydroxyl group of isovitexin. The xylosyl-transferase controlled by the gene gX had a "true Km value" of 0.77 mM for UDP-xylose. The "true Km value" for isovitexin was &lt;&lt; 0.04 mM. The transfer of glucose from UDP-glucose to the 7-hydroxyl group of isovitexin is catalyzed by the enzyme controlled by gene gG. In plants possessing both the alleles gG and gX, only the gene product of gG, i.e., isovitexin 7-O-glucoside, was found. In this respect gG is dominant over allele gX. In petal extracts of these gGgX plants, however, besides UDP-glucose: isovitexin 7-O-glucosyltransferase, also UDP-xylose: isovitexin 7-O-xylosyltransferase could be detected. This means that the dominance is not a consequence of transcriptional and/or translational control. Enzyme kinetic experiments showed that inhibition of the xylosyltransferase by the endproduct of the glucosyltransferase did not occur. Comparison of the enzyme kinetic parameters revealed that the dominance is probably caused by differences in Vmax between the two enzymes, both working at saturating isovitexin concentrations. A competition model is suggested which explains why the amount of isovitexin 7-O-glucoside in gGgG plants and the amount of isovitexin 7-O-xyloside in gXgX plants are about the same, whereas in gGgX plants isovitexin 7-O-xyloside escapes detection. The differences in distribution of the isovitexin glycosylation genes in the two species M. album and M. dioicum are discussed.
THE GENETIC IDENTIFICATION OF A HETEROCHROMATIC SEGMENT ON THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Parry Dilys M , Sandler L 
Published: January 2021

ABSTRACT
An autosomal euchromatic maternal-effect mutant, abo (= abnormal oocyte), interacts with, or regulates the activity of, the heterochromatin of the sex chromosomes of Drosophila melanogaster. It is shown that this interaction or regulation with the X chromosome involves a specific heterochromatic locus or small region that maps to the distal penultimate one-eighth of the basal X-chromosome heterochromatic segment.
ASSOCIATION OF ALLELES OF THE MALIC DEHYDROGENASE LOCUS WITH A PERICENTRIC INVERSION IN DROSOPHILA ROBUSTA
Authors: Prakash Satya , Levitan Max 
Published: January 2021

ABSTRACT
Associations of Malic dehydrogenase alleles with the third chromosome arrangement 3R and the pericentric arrangement 3L-R are described. Even though significant associations between alleles and inversions exist within a population, there is an overall similarity in MDH allele frequencies in different populations inspite of large differences in inversion frequencies.
CORRELATIONS IN MULTI-LOCUS GENETIC SYSTEMS: A MATHEMATICAL MODEL
Authors: Falk C T , Falk H 
Published: January 2021

ABSTRACT
A spin model with parallels to a multi-locus genetic model is presented which makes it possible to calculate the correlation between allelic states at any two loci in a population at equilibrium. The main features are: (1) The decay of correlation with distance may be expressed essentially as a linear combination of two exponentials, one of which dominates when the two loci are sufficiently far apart. (2) The correlation between two loci a specified distance apart is increased as the number of loci in the entire system increases. The results are compared with those of other theoretical models and discussed in the light of available experimental data. Possible ways of generalizing the model are outlined. However, additional experimental data is clearly needed to indicate the genetic relevance of work of this nature.
REVERTANTS AND SECONDARY arom-2 MUTANTS INDUCED IN NON-COMPLEMENTING MUTANTS IN THE arom GENE CLUSTER OF NEUROSPORA CRASSA
Authors: Case Mary E , Giles Norman H 
Published: January 2021

ABSTRACT
Extensive genetical and biochemical studies have been performed with revertants and secondary arom-2 mutants induced in two different primary non-complementing mutants which map within the arom gene cluster of Neurospora crassa. These studies indicate that mutant M54 but not M25 can revert by super-suppressor mutations in unlinked genes, thus confirming previous evidence that M54 contains a nonsense codon. At least three new super suppressors of M54 have been detected. All four super suppressors (including one previously detected) when combined with M54 result in high levels of all five of the arom enzymic activities in the form of arom multienzyme complexes very similar to (but not necessarily identical with) that in wild type (WT).—Evidence has also been obtained that the two non-complementing mutants can yield revertants which appear to result from true back mutations and produce arom aggregates essentially indistinguishable from that of WT. In addition, M25, but not M54, when plated on quinic acid yields revertants (secondary mutants) some of which are phenotypically indistinguishable from arom-2 primary mutants and others of which, although also mapping within the arom-2 gene, exhibit unusual properties. Genetic evidence indicates that the M25 secondary mutants are localized within the arom-2 gene, but that they arise from mutational events more complex than ones resulting in single base pair changes in the M25 codon.—The recovery of secondary arom-2 mutants as revertants of non-complementing arom mutants provides strong evidence, independent of earlier recombination data, that non-complementing arom mutants are located within the arom-2 structural gene of the arom gene cluster. In addition, the occurrence and characteristics of these secondary arom-2 mutants provide strong evidence, independent of the results with nonsense suppressors, that the arom gene cluster is transcribed, beginning with the arom-2 gene, as a single polycistronic messenger ribonucleic acid (mRNA) molecule which is subsequently translated into the arom multienzyme complex.
CHROMOSOMAL LOCATION BY USE OF TRISOMICS AND NEW ALLELES OF AN ENDOPEPTIDASE IN ZEA MAYS
Authors: Nielsen Gunnar , Scandalios John G 
Published: January 2021

ABSTRACT
An association was found earlier between the Ep1 gene locus coding for an endopeptidase and the endosperm color gene Y1 on chromosome 6 of Zea mays. By employing primary trisomics we have unequivocally placed the Ep1 gene on chromosome 6, closely linked to the Y1 locus. Additionally we describe new alleles at the Ep1 locus, and present evidence for the existence of a second endopeptidase system in maize.
EFFECTS OF DOSE ON THE INDUCTION OF DOMINANT-LETHAL MUTATIONS WITH TRIETHYLENEMELAMINE IN MALE MICE
Authors: Matter B E , Generoso W M 
Published: January 2021

ABSTRACT
Dose effects of triethylenemelamine (TEM) in the induction of dominant-lethal mutations were studied at the early spermatozoon, midspermatid and spermatocyte stages. The pattern of effects on spermatocytes, unlike midspermatids and early spermatozoa, indicated possible cytotoxic damage, so for the determination of TEM dose-response curves in the induction of genetic damage only the data for midspermatids and early spermatozoa were used. The TEM dose-effect curves for those two stages differ markedly from ethyl methanesulfonate (EMS) dose-effect curves. Beginning with the lowest doses at which significant effects are observed, there is a considerably more rapid increase in dominant-lethal effects with dose of EMS than TEM. Another marked difference between the two compounds is in the ratio of the genetically effective dose (as measured by dominant-lethal mutations) to the lethal dose. The ratio is 1:100 for TEM and only 1:3.5 for EMS; thus, TEM is mutagenic far below its toxic level. Obviously, these results have important implications not only for our understanding of the nature of chemical induction and recovery of chromosomal aberrations but also for the practical problems of evaluating the mutagenic effects of chemicals.
DNA DAMAGE AND REPAIR IN EUKARYOTIC CELLS
Authors: Painter R B 
Published: January 2021

ABSTRACT
Damage in DNA after irradiation can be classified into five kinds: base damage, single-strand breaks, double-strand breaks, DNA-DNA cross-linking, and DNA-protein cross-linking. Of these, repair of base damage is the best understood. In eukaryotes, at least three repair systems are known that can deal with base damage: photoreactivation, excision repair, and post-replication repair. Photoreactivation is specific for UV-induced damage and occurs widely throughout the biosphere, although it seems to be absent from placental mammals. Excision repair is present in prokaryotes and in animals but does not seem to be present in plants. Post-replication repair is poorly understood. Recent reports indicate that growing points in mammalian DNA simply skip past UV-induced lesions, leaving gaps in newly made DNA that are subsequently filled in by de novo synthesis. Evidence that this concept is oversimplified or incorrect is presented.—Single-strand breaks are induced by ionizing radiation but most cells can rapidly repair most or all of them, even after supralethal doses. The chemistry of the fragments formed when breaks are induced by ionizing radiation is complex and poorly understood. Therefore, the intermediate steps in the repair of single-strand breaks are unknown. Double-strand breaks and the two kinds of cross-linking have been studied very little and almost nothing is known about their mechanisms for repair.—The role of mammalian DNA repair in mutations is not known. Although there is evidence that defective repair can lead to cancer and/or premature aging in humans, the relationship between the molecular defects and the diseased state remains obscure.
PROTEIN SYNTHESIS DIRECTED BY THE RNA FROM A PLANT VIRUS IN A NORMAL ANIMAL CELL
Authors: Knowland John 
Published: January 2021

ABSTRACT
RNA from tobacco mosaic virus can be translated inside oocytes of the frog Xenopus laevis. The main product is a polypeptide with a molecular weight of 140,000. There is no evidence for coat protein synthesis, and it is unlikely that the polypeptide that is made contains either a whole or a partial coat protein sequence.
The picture of translation of tobacco mosaic virus RNA obtained using oocytes is very much simpler than that found using cell-free protein-synthesizing systems, in which a great many polypeptides are made under the direction of tobacco mosaic virus RNA. The reasons for this difference are discussed, and the relative merits of in vivo and in vitro protein-synthesizing systems are compared.
EXPERIMENTAL STUDIES ON THE ORIGIN OF CULTIVATED RICE
Authors: Oka Hiko-Ichi 
Published: January 2021

ABSTRACT
1) Contributions to the origin of cultivated rice made by the author and his colleagues were briefly reviewed under several headlines.—2) Two parallel series of evolution of cultivated species, the Asian form of Oryza perennis to O. sativa and O. breviligulata to O. glaberrima, were pointed out compared.—3) In both the two series, a continuous array of intergrades between wild and cultivated species is found in a particular region. The pattern of character variations among those intermediate plants was considered as indicating the evolutionary path, and the monophyletic origin of the Indica and Japonica types of O. sativa was discussed.—4) The conditions of establishment of a weedy form of O. perennis found in India were discussed. It was noticed that cultivation by man in itself works as a selective agent for cultivated types.
Chromosome-level reference genome of the European wasp spider Argiope bruennichi: a resource for studies on range expansion and evolutionary adaptation
Authors: Sheffer Monica M , Hoppe Anica , Krehenwinkel Henrik , Uhl Gabriele , Kuss Andreas W , Jensen Lars , Jensen Corinna , Gillespie Rosemary G , Hoff Katharina J , Prost Stefan 
Published: January 2021

Abstract

Background
Argiope bruennichi, the European wasp spider, has been investigated intensively as a focal species for studies on sexual selection, chemical communication, and the dynamics of rapid range expansion at a behavioral and genetic level. However, the lack of a reference genome has limited insights into the genetic basis for these phenomena. Therefore, we assembled a high-quality chromosome-level reference genome of the European wasp spider as a tool for more in-depth future studies.

Findings
We generated, de novo, a 1.67 Gb genome assembly of A. bruennichi using 21.8× Pacific Biosciences sequencing, polished with 19.8× Illumina paired-end sequencing data, and proximity ligation (Hi-C)-based scaffolding. This resulted in an N50 scaffold size of 124 Mb and an N50 contig size of 288 kb. We found 98.4% of the genome to be contained in 13 scaffolds, fitting the expected number of chromosomes (n = 13). Analyses showed the presence of 91.1% of complete arthropod BUSCOs, indicating a high-quality assembly.

Conclusions
We present the first chromosome-level genome assembly in the order Araneae. With this genomic resource, we open the door for more precise and informative studies on evolution and adaptation not only in A. bruennichi but also in arachnids overall, shedding light on questions such as the genomic architecture of traits, whole-genome duplication, and the genomic mechanisms behind silk and venom evolution.
Mantle serpentinization beneath a failed rift and post-spreading magmatism in the northeastern South China Sea margin
Authors: Liu Yutao , Li Chun-Feng , Wen Yonglin , Yao Zewei , Wan Xiaoli , Qiu Xuelin , Zhang Jia-zheng , Abbas Aqeel , Peng Xi , Li Gang 
Published: January 2021

SUMMARYThe post-spreading magmatic activities in the northeastern South China Sea (SCS) margin are very strong, evidenced by widely distributed high-velocity lower crust (HVLC) and numerous volcanoes. However, there are large contrasts in magmatic activities and crustal structure between the Southern Depression (TSD) of the Tainan Basin and the volcanic continental slope area further south. We analyse their crustal P-wave velocity structures based on a newly acquired wide-angle ocean bottom seismic data set. The Cenozoic strata below the TSD, a Cenozoic failed rift, are relatively thick (∼3–4.5 km) with velocities from 1.6 to 3.6–3.9 km s–1, whereas the Mesozoic strata are relatively thin (∼1–2.5 km) with velocities from 4.3 to 4.6–5.2 km s–1. In the TSD, magmatic activities are relatively weak and the crust is severely thinned (∼4 km). The crust is 9–15 km thick below the volcanic continental slope area, which shows extensive volcanism. We identified HVLC below the failed rift of the TSD (Zone 1) and attributed it to mantle serpentinization, whereas the imaged HVLC below the volcanic continental slope (Zone 3) and HVLC adjacent to the failed rift of the TSD (Zone 2) are due to post-spreading magmatic underplating/intrusions. At the model distance ∼90 km, lateral transition from magmatic underplating/intrusions to mantle serpentinization occurred abruptly. We concur that post-spreading cooling and thermal contraction in the nearby SCS oceanic lithosphere can trigger decompressive melting and deformation in the thinned continental slope zone. Our study shows that, in addition to mantle serpentinization in the continent–ocean transition (COT) zone, mantle can also be serpentinized below the rift during early-stage rifting. Weak syn-rifting magmatism and mantle serpentinization below the failed rift support that the northeastern SCS has a magma-poor margin.
Screening for mild cognitive impairment among older Albanian patients by clinical pharmacists
Authors: Harasani Klejda , Xhafaj Delina , Lekaj Adrisa , Veshi Livia , Olvera-Porcel Maria del Carmen 
Published: January 2021

Abstract

Objectives
To assess the prevalence of mild cognitive impairment (MCI) and its correlated factors among elderly Albanian patients using different screening tools applied by clinical pharmacists.

Methods
Patients aged 60 years old or more from two primary care centers located in two Albanian cities were included in the study. Two clinical pharmacists applied the MoCA/MoCA B (Montreal Cognitive Assessment/Basic) and the Mini-Cog in Albanian. A predictive multivariate logistic regression analysis and Kappa statistic were conducted.

Key findings
The prevalence of MCI using MoCA/MoCA B and Mini-Cog scales was 75.73 and 20.39%, respectively. There was a poor degree of agreement between them (Kappa 2.38). Older men had an increased risk of MCI.

Conclusions
The involvement of clinical pharmacists in screening for MCI might help in selecting vulnerable individuals for more specialized examination. The MoCA/MoCA B tool is recommended for higher sensitivity.
Numerical homogenization for nonlinear strongly monotone problems
Authors: Verfürth Barbara 
Published: January 2021

AbstractIn this work we introduce and analyse a new multiscale method for strongly nonlinear monotone equations in the spirit of the localized orthogonal decomposition. A problem-adapted multiscale space is constructed by solving linear local fine-scale problems, which is then used in a generalized finite element method. The linearity of the fine-scale problems allows their localization and, moreover, makes the method very efficient to use. The new method gives optimal a priori error estimates up to linearization errors. The results neither require structural assumptions on the coefficient such as periodicity or scale separation nor higher regularity of the solution. The effect of different linearization strategies is discussed in theory and practice. Several numerical examples including the stationary Richards equation confirm the theory and underline the applicability of the method.
Nature Identification of Chinese Herbal Medicine Compounds Based on Molecular Descriptors
Authors: Wei Guohui , Fu Xianjun , Wang Zhenguo 
Published: January 2021

AbstractBackgroundThe nature of Chinese herbal medicines (CHMs) is a bridge between traditional Chinese medicine and clinical application. Accurate nature identification of CHMs is essential for guiding the clinical application of CHMs.ObjectiveTo develop a new method for nature identification of CHMs according to compounds in CHMs.MethodsThe nature of a CHM is a comprehensive manifestation of the properties of various compounds in the CHM. In this study, 2012 CHM compounds were extracted to construct a compound data set. Molecular descriptors were utilized to build an identification model for classification of the cold-hot-neutral nature of CHM compounds.ResultsThe predictive accuracy and confusion matrix were validated using the assembled data set. The best model produced accuracies of 96.5 ± 0.5% and 86.5 ± 1.5% on training set and test set, respectively. Furthermore, the identification model is robust in predicting the cold-hot-neutral nature of CHM compounds.ConclusionThis work shows how a classification model for medical nature identification can be developed. The derived model can be utilized for the application of CHMs.HighlightsTo construct a nature identification model for analysis of the cold-hot-neutral nature of CHMs according to the compounds in CHMs.
Digital Retaliation? Denial-of-Service Attacks after Sanction Events
Authors: Lutscher Philipp M 
Published: January 2021

Abstract
Conventional wisdom expects to see a rise in cyber activities around aggressive foreign policy events. In this article, I test this claim by investigating whether sanctions lead to an increase in denial-of-service (DoS) attacks using new data on DoS attacks measured from Internet traffic. Exploring the development of DoS attacks around sanctions imposed against Russia in 2014 indeed shows an increase of DoS attacks against several sanction sender states. Extending this case study to a systematic analysis, including all sanction threats and impositions made by the United States and the European Union between 2008 and 2016, shows no apparent patterns. When I exclusively consider sanctions against technologically advanced countries, however, the frequency of attacks rises systematically against the United States. It thus appears that states do not always have to expect a digital retaliation after aggressive foreign policies. Nevertheless, sanctioning countries may have to anticipate an increase in DoS attacks when their governments impose sanctions against technologically advanced countries.
Perforation of the descending colon diverticulum in a patient following recovery from severe COVID-19 pneumonia: a case report
Authors: Hamaoka Michinori , Shiozaki Shohei , Nakahara Hideki , Itamoto Toshiyuki 
Published: January 2021

Abstract
The outcome of surgery in patients who have recovered from severe coronavirus disease 2019 (COVID-19) is unknown. Herein, we present a case of an emergency operation for acute pan-peritonitis due to perforation of the descending colon diverticulum in a patient who recovered from severe COVID-19 pneumonia. A 59-year-old man, who had recovered from severe COVID-19 pneumonia ~6 months previously, developed acute pan-peritonitis due to perforation of a diverticulum in the descending colon. Emergency surgery was performed, and the perforation was sutured and closed. He was discharged from the hospital 13 days postoperatively. There was no relapse of COVID-19 during the perioperative period of peritonitis surgery. General perioperative management may, therefore, be sufficient in patients who have recovered from COVID-19.
Black holes LIGO/Virgo domination and single-lined binaries with a black hole candidate component
Authors: Lipunov Vladimir , Gorbovskoy Evgeny , Grinshpun Valeria , Vlasenko Daniil 
Published: January 2021

ABSTRACT
In this letter, we note that the observed in the LIGO/Virgo experiment ratio of the detection rate of black holes to the rate of detection of binary neutron stars requires the assumption of a ‘conservative’ collapse of massive stars into a black hole: almost all the mass of the collapsing star goes under the horizon. This is consistent with the large masses of black holes detected by LIGO/Virgo. On the other hand, the assumption of a small loss of matter during the collapse into a black hole is in good agreement with the small eccentricity of single-lined binaries. At the same time, the absence of X-rays from most black holes in binary systems with blue stars is explained. We argue that three sets of LIGO/Virgo observations and data on the single-lined binary with a candidate black hole component confirm the scenario of the evolution of massive field binaries.