bluuebunny/crossref_metadata_2025_split huggingface dataset:
EVIDENCE FOR X-LINKAGE OF STEROID SULFATASE IN THE MOUSE: STEROID SULFATASE LEVELS IN OOCYTES OF XX AND XO MICE
Authors: Gartler Stanley M , Rivest Martha 
Published: January 2021

ABSTRACT
The steroid sulfatase (STS) levels in mature oocytes of XX and XO mice were assayed along with lactate dehydrogenase (LDH), an autosomal marker, and glucose-6-phosphate dehydrogenase (G6PD), a known X-linked gene. LDH levels in XX and XO oocytes were equal, whereas STS and G6PD levels were approximately twice as high in XX oocytes as in XO oocytes. These results indicate that the STS gene is X-linked in the mouse just as it is in humans. Assays of STS in kidney tissue of XX and XO mice indicated dosage compensation for the gene, which is different from that observed in humans.
GENETIC CHARACTERIZATION OF THE SufJ FRAMESHIFT SUPPRESSOR IN SALMONELLA TYPHIMURIUM
Authors: Bossi Lionello , Kohno Tadahiko , Roth John R 
Published: January 2021

ABSTRACT
A new suppressor of +1 frameshift mutations has been isolated in Salmonella typhimurium. This suppressor, sufJ, maps at minute 89 on the Salmonella genetic map between the argH and rpo(rif) loci, closely linked to the gene for the ochre suppressor tyrU(supM). The suppressor mutation is dominant to its wild-type allele, consistent with the suppressor phenotype being caused by an altered tRNA species. The sufJ map position coincides with that of a threonine tRNA(ACC/U) gene; the suppressor has been shown to read the related fourbase codons ACCU, ACCC, ACCA.—The ability of sufJ to correct one particular mutation depends on the presence of a hisT mutation which causes a defect in tRNA modification. This requirement is allele specific, since other frameshift mutations can be corrected by sufJ regardless of the state of the hisT locus.—Strains carrying both a sufJ and a hisT mutation are acutely sensitive to growth inhibition by uracil; the inhibition is reversed by arginine. This behavior is characteristic of strains with mutations affecting the arginine-uracil biosynthetic enzyme carbamyl phosphate synthetase. The combination of two mutations affecting tRNA structure may reduce expression of the structural gene for this enzyme (pyrA).
GENE INTERACTIONS BETWEEN POTASSIUM-SENSITIVE AND POTASSIUM-RESISTANT MUTATIONS OF PARAMECIUM TETRAURELIA
Authors: Cronkite Donald L 
Published: January 2021

ABSTRACT
Two unlinked recessive mutations (ks-1 and ks-2) have been induced in Paramecium tetraurelia stock 51. Wild-type survives and grows when up to 30 mm KCl is added to the medium, but the mutants cease to grow and die when added KCl reaches 20-25 m m. These K+-sensitives have been crossed to stocks containing the K+-resistant genes, fA (very resistant) and kA(moderately resistant). All four genes are unlinked. Double mutants of ks-1 and either kA or fA are as resistant as the resistant member of the pair. Doubles of ks-2 and kA are like wild type, and doubles of ks-2 and fA are shifted from high resistance toward wild type. Gene ks-2 acts like a suppressor of kA and fA. This suppression can be understood in terms of the known biochemical defects of the mutants.
APPLICATION OF THE OVARIAN TERATOMA MAPPING METHOD IN THE MOUSE
Authors: Eppig Janan T , Eicher Eva M 
Published: January 2021

ABSTRACT
Murine ovarian teratomas were used to determine recombination percentages for gene-gene and centromere-gene intervals. Data were obtained utilizing a recombinant inbred strain, LTXBJ, and a number of newly developed LT/SvEi congenic strains. ——Centromere-gene recombination was measured at 11.3 ± 1.2% for the centromere of chromosome 7 – Gpi-1 interval and 15.8 ± 2.4% for the centromere of chromosome 14 – Np-1 interval using the ovarian teratoma method. The centromere – Np-1 interval was measured at 26.5 ± 3.6% using a standard backcross involving the Rb6Bnr Robertsonian translocation as a centromere marker. ——To assess the accuracy of the ovarian teratoma mapping method, we compared the recombination frequency obtained for the Mpi-1–Mod-1 interval on chromosome 9 using the ovarian teratoma method to that obtained using a standard backcross. The recombination percentage was 22.9 ± 5.4 using the ovarian teratoma method and 18.6 ± 3.3 using the backcross method, indicating that the two methods produce equivalent estimates of recombination. In addition, for centromere-gene intervals known to be more than 30 cM in length, the ovarian teratoma method was consistent with classical recombination methods, yielding high recombination percentages. We conclude from these results that the ovarian teratoma mapping method is a reliable method for estimating recombination frequencies and the most accurate method available for estimating centromere-gene recombination frequency in the mouse.
THE EXPERIMENTAL ASSESSMENT OF FITNESS IN DROSOPHILA. II. A COMPARISON OF COMPETITIVE AND NONCOMPETITIVE MEASURES
Authors: Haymer D S , Hartl D L 
Published: January 2021

ABSTRACT
Twelve diverse strains of Drosophila melanogaster have been examined with respect to their individual fitness components and with respect to their relative performance under competitive and noncompetitive conditions. Individual fitness components included estimates of time until successful copulation (t), fecundity (f) and egg-to-adult viability (v), and a composite index of overall fitness of the form fv/t was used for comparisons among strains. Noncompetitive performance was assessed in terms of the biomass (standing crop) and productivity of equilibrium experimental populations. Competitive performance was assessed in terms of relative competitive ability vis-à-vis a standard compound-autosome-bearing strain in single-generation tests. A significant correlation was found between the composite index of individual fitness components and the competitive compound-autosome test. Although the biomass and productivity of equilibrium populations were correlated with each other, neither of these noncompetitive measures was correlated with individual fitness components or with the composite index. We suggest that the performance of strains in such noncompetitive tests may be related to what Wright has called the "mean selective value" of the populations. Judging from their association with the composite index of individual fitness components, competitive tests such as the compound-autosome test seem to be related more nearly to the average Darwinian fitness of the populations.
MARKER RESCUE FROM BLEOMYCIN-TREATED CHLAMYDOMONAS REINHARDI
Authors: Hourcade Dennis E 
Published: January 2021

ABSTRACT
A new method has been developed for gene transfer in eukaryotic cells. Chlamydomonas reinhardi, a unicellular eukaryotic alga, was treated with a lethal dose of bleomycin, an agent that induces chromosome breakage. Bleomycin-treated cells were mated with untreated cells, and the mixture was plated onto selective agar medium. The progeny that arose contained the genetic markers from the untreated parent plus a subset of the genetic markers from the bleomycin-treated parent. Those markers derived from the untreated parent were stable, whereas those recovered from the bleomycin-treated parent were often unstable. Markers closely linked in the bleomycin-treated parent were usually rescued or lost together, whereas distantly linked or unlinked markers were rescued or lost independently. These results suggest that bleomycin treatment of C. reinhardi leads to the formation of chromosome fragments, and fusion of bleomycin-treated cells to untreated cells results in the rescue of some of these fragments. This procedure provides a new means of gene transfer that may be useful for genetic mapping, genetic engineering and for the study of genetic organization.
TRANSPOSABLE ELEMENTS IN MENDELIAN POPULATIONS. III. STATISTICAL RESULTS
Authors: Kaplan Norman L , Brookfield John F Y 
Published: January 2021

ABSTRACT
Methods are proposed for estimating the parameters in the frequency spectrum derived from the model of Langley, Brookfield and Kaplan for the evolution of a transposable element in a finite Mendelian population. Statistical properties of these estimates are studied, and the results are supported with simulation data. The effects on the estimates caused by possible insensitivities of the experimental technique are also discussed. To illustrate the proposed methodology, the data of Montgomery and Langley are analyzed.
STUDIES OF ENZYME POLYMORPHISM IN THE KAMUELA POPULATION OF DROSOPHILA MERCATORUM. III. EFFECTS OF VARIATION AT THE αGPD LOCUS AND SUBFLIGHT STRESS ON THE ENERGY CHARGE AND GLYCOLYTIC INTERMEDIATE CONCENTRATIONS
Authors: Clark R L , Boerwinkle Eric , Brewer G J , Sing C F 
Published: January 2021

ABSTRACT
We have employed a "level crossing" strategy to study the primary effects of an enzyme polymorphism in Drosophila mercatorum. This strategy consists of following genetic differences across intervening phenotypes to possible fitness effects. In this paper, we report the steady state concentrations of the glycolytic intermediates and the adenylates (intervening phenotypes) in two genotypes (αGPD-F, αGPD-S) at two stress levels (rest, subflight). We did not detect a genotype or a genotype by stress interaction effect on glycolytic intermediate or adenylate concentrations despite the ability of the experimental design to detect a 20 to 50% difference from the mean of a control. The flux of glycolysis is adequate to maintain the energy charge in both strains under the stress levels considered. If there is a fitness difference between these αGPD variants, it is unlikely to be a result of modifications of glycolysis. Subflight stress, however, resulted in an increase in metabolic flux. The observed pattern of intermediate concentration differences is consistent with the modulation of glycolysis by the ratio of the ATP and AMP concentrations acting on phosphofructokinase activity.
PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN RYE AND GRASSHOPPERS
Authors: Santos J L , Orellana J , Giraldez R 
Published: January 2021

ABSTRACT
Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.
CYCLOPHOSPHAMIDE-INDUCED IN VIVO SISTER CHROMATID EXCHANGES (SCE) IN MUS MUSCULUS. III. QUANTITATIVE GENETIC ANALYSIS
Authors: Reimer Dorothy L , Singh Shiva M 
Published: January 2021

ABSTRACT
In vivo cyclophosphamide (CP)-induced sister chromatid exchanges (SCEs) were evaluated in females from five genetic strains of mice (C57BL/6J, C3H/S, 129/ReJ, BALB/c and DBA/2) and their F1 hybrids. Baseline (noninduced) SCE values differ significantly among strains, 129/ReJ having the lowest and DBA/2 having the highest mean SCE per cell values. In general, the baseline SCE of a given F1 is within the range of its corresponding parental strains or near the lower parental value. Furthermore, there is a genotype-dependent increase in mean SCEs per cell with CP dose. Strain differences in SCE induction are noted particularly at the two higher CP doses (4.50 and 45.0 mg/kg). In general, F1 hybrids involving a strain with high induced SCEs and a strain with low induced SCEs exhibit mean SCE values that are closer to the value of the lower strain. F1s involving two strains with high SCEs or two strains with low SCEs yield SCEs not different from parental strains. The method of diallel cross analysis showed the order of dominance of these strains in SCE induction to be 129/ReJ BALB/c C3H/S DBA/2 C57BL/6J. These results support the involvement of predominantly nonadditive genetic factors as major gene(s) in SCE induction. In addition, involvement of random and independent events in SCE induction is suggested by the distribution of SCEs which follows a Poisson distribution.
IDENTIFICATION OF AN AUTOSOMAL LOCUS AFFECTING STEROID SULFATASE ACTIVITY AMONG INBRED STRAINS OF MICE
Authors: Erickson Robert P , Harper Kenneth , Kramer James M 
Published: January 2021

ABSTRACT
We have found an activity variant for testicular and liver steroid sulfatase among inbred strains of mice that is not X-linked. C57BL/6J, SM/J and SWR/J testicular extracts hydrolyze 3H-dehydroepiandrosterone sulfate twice as rapidly as do A/J extracts. The C3H/HeJ and DBA/2J strains were intermediate. The Km values for C57BL/6J and A/J are 2.29 ± 0.10 and 1.01 ± 0.02 μM, respectively. The F1 values in both directions were intermediate, which argues against X-linkage of this trait. F2 values show scattered high-intermediate-low values compatible with assay variation superimposed on the segregation of codominant alleles. When assayed for both testicular and liver steroid sulfatase, nine recombinant inbred lines between A/J and C57BL/6J segregate to near the parental strain values. Thus, this activity variation for steroid sulfatase appears to be determined by a single gene, which is not X-linked. Sex and steroidal hormone differences in liver steroid sulfatase activity were not present in the A/J strain, but females of the C57BL/6J and some recombinant inbred lines had higher levels. Electrophoretic studies only disclosed a variant in the SM/J strain, which seems to be secondary to the well-known neuraminidase variation in SM/J.
EPISTATIC GROUPING OF REPAIR-DEFICIENT MUTANTS IN NEUROSPORA: COMPARATIVE ANALYSIS OF TWO uvs-3 ALLELES, uvs-6 AND THEIR mus DOUBLE MUTANT STRAINS
Authors: Käfer Etta 
Published: January 2021

ABSTRACT
The nuclease halo mutant, nuh-4, of Neurospora crassa was identified conclusively as an allele of uvs-3, a gene involved in error-prone DNA repair. Like uvs-3, nuh-4 showed spontaneous mutator effects, and any previous contradictory findings were found to be due to newly arisen mutants. In normal strains the two alleles are noncomplementing and indistinguishable for sensitivity to UV and methyl methanesulfonate (MMS). Like uvs-3, nuh-4 lacked secretion of the extracellular enzyme, DNase A, a Ca++-dependent strand-nonspecific endonuclease which was found to be phosphate repressible. However, nuh-4 differed from uvs-3 in showing much higher conidial viability and lower sensitivity to ionizing radiation and mitomycin C.——Epistatic relationships of the two uvs-3 alleles with seven other MMS-sensitive mutants were determined and compared with those of the highly X-ray-sensitive mutant, uvs-6. Three epistatic groups were found, based on survival of double mutant strains relative to that of their component single mutant strains after treatment with MMS. Both, uvs-3 and nuh-4, were epistatic to mus-9 which also is a mutator. None of the three produced viable double mutants in crosses to uvs-6. On the other hand, uvs-6, but not the uvs-3 alleles, was found to be epistatic to mus-7 and mus-10. The excision-defective uvs-2 and mus-8 both showed synergism with the uvs-3 alleles and with uvs-6, forming a third, separate epistatic group.
Twelve Years after the Financial Crisis—Too-big-to-fail is still with us
Authors: Hellwig Martin 
Published: January 2021

ABSTRACT
This article comments on the Consultation Report published by the Financial Stability Board (FSB) evaluating the success of regulatory reforms since the global financial crisis of 2007–2009. It argues that the FSB’s assessment of the role of equity is too narrow, being phrased in terms of bankruptcy avoidance and risk-taking incentives, without attention to debt overhang creating distortions in funding choices, the systemic impact of ample equity reducing deleveraging needs after losses, or equity contributing to smoothing of lending and asset purchases over time. The FSB’s treatment of systemic risk also pays too little attention to the mutual interdependence of different parts of the system, which is not well captured by linear causal relationships. Finally, the article points out that bank resolution of systemically important institutions is still not viable, due to lack of political acceptance of single-point-of-entry procedures and bail-in. Within the European Union, this viability is further undermined by the lack of sufficient funding for banks in resolution and the lack of fiscal backstops.
Circumstance, Answerability, and Luck
Authors: Radoilska Lubomira 
Published: January 2021

Abstract
This paper identifies a distinctive kind of moral luck, deep circumstantial luck, and then explores its effects on moral responsibility. A key feature of the phenomenon is that it is recurrent rather than one-off. It also affects agents across a wide range of situations making it difficult to detect. Deeply unlucky agents are subject to unfavourable moral assessments through no fault of their own both in specific cases and when they try to respond to such initial assessments. In this respect, deep circumstantial luck takes the form of a normative burden that grows over time. A process-oriented conception of moral responsibility as answerability is proposed to explain this phenomenon and highlight its implications for rethinking vicarious responsibility.
A Novel Mathematical Model to Calculate the Osteotomy in Ankylosing Spondylitis
Authors: Akpolat Ahmet Onur , Tasci Fatih , Kilinc Bekir Eray , Celebi Mehmet Emin , Balioglu Mehmet Bülent 
Published: January 2021

Mini
The authors developed a mathematical model to the sagittal vertical axis (SVA) change in ankylosing spondylitis whom PSO is planned. The mathematical model was developed using trigonometric equations. No significant difference exists between postop SVA change amount and SVA calculated. The mathematical model is reliable in restoring the global sagittal balance.

Study Design.
Retrospective study.

Objective.
This study aims to develop a mathematical model to help precalculate the sagittal vertical axis (SVA) change in patients with ankylosing spondylitis (AS) with rigid kyphotic deformity for whom pedicle subtraction osteotomy (PSO) is planned.

Summary of Background Data.
SVA is an important metric parameter used to evaluate the global sagittal balance. Previous studies have investigated angular changes in pelvic parameters using PSO; however, no mathematical model is available to calculate SVA change as a metric in these studies.

Methods.
Twenty-one patients who met the inclusion criteria were included in the study. The mathematical model was developed using basic trigonometric equations. Measurements for SVA, lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), and the mathematical model were performed in the preop and early postop period. The amount of SVA change in the poststop period was calculated in the mathematical model.

Results.
The mean age was 33.81 ± 6.01 years. No statistical difference was observed between MATLAB and the angles used in the mathematical modeling (P > 0.05). No significant difference exists between postop SVA change amount and SVA calculated via mathematical modeling (P > 0.05). A statistically significant difference was observed between preop and postop measurements of LL, SVA, PT, and SS variables (P < 0.001). No statistically significant difference existed between PI (P > 0.05).

Conclusion.
This novel mathematical model is reliable in restoring the global sagittal balance of the patients with AS scheduled for PSO and prevent the osteotomy complications.

Level of Evidence: 3
Pulmonary pathology of COVID-19: a review of autopsy studies
Authors: Borczuk Alain C. 
Published: January 2021

Purpose of review
COVID-19 lung injury is a common manifestation of severe illness. Lung tissue examination has been largely derived from autopsy – a combination of case reports, small and moderately sized series with international scope. Common and uncommon histopathology provides insight into the progression of severe, fatal disease.

Recent findings
COVID-19 lung histology is most commonly diffuse alveolar damage as part of acute respiratory distress syndrome. Lung injury can be temporally heterogeneous, with patterns of healing alongside new injury. Viral studies, including immunohistochemistry, RNA in-situ hybridization, and tissue-based Polymerase chain reaction (PCR) assist in discerning complications of therapy (e.g. ventilator-associated pneumonia) from primary viral-induced injury. Response to viral infection produces systemic effects, and one major manifestation is thrombosis of micro-circulation and larger vessels. Less common patterns include neutrophil-rich inflammation, raising speculation that neutrophil extra-cellular traps may play a role in both viral control and exaggerated immune response.

Summary
The heterogeneity of fatal cases- persistence of viral infection in lung, clearance of virus but severe lung injury, thrombosis, and exaggerated immune response – suggest that antiviral, antithrombotic, anti-inflammatory, and supportive therapy play a role in treatment, but that the patient-specific cause and timing of the lung injury is important in choosing intervention.
Rapid selection of HIV envelopes that bind to neutralizing antibody B cell lineage members with functional improbable mutations
Authors: Swanson Olivia , Rhodes Brianna , Wang Avivah , Xia Shi-Mao , Melissa Cooper , Parks Robert , Sanzone Aja , Louder Mark K. , Lin Bob C. , Doria-Rose Nicole A. , Saunders Kevin O. , Bonsignori Mattia , Wiehe Kevin , Haynes Barton F. , Azoitei Mihai L. 
Published: January 2021

SummaryElicitation of broadly neutralizing antibodies (bnAbs) by an HIV vaccine will involve priming the immune system to activate antibody precursors, followed by boosting immunizations to select for antibodies with functional features required for neutralization breadth. The higher the number of acquired mutations necessary for function, the more convoluted are the antibody developmental pathways. HIV bnAbs acquire a large number of somatic mutations, but not all mutations are functionally important. Here we identified a minimal subset of mutations sufficient for the function of the naturally occurring V3-glycan bnAb DH270.6. Using antibody library screening, candidate envelope immunogens that interacted with DH270.6-like antibodies containing this set of key mutations were identified and selectedin vitro. Our results demonstrate that less complex B cell evolutionary pathways than those naturally observed exist for the induction of HIV bnAbs by vaccination, and establish rational approaches to identify boosting sequential envelope candidate immunogens.