bluuebunny/crossref_metadata_2025_split huggingface dataset:
MOLECULAR FATE OF HETEROLOGOUS BACTERIAL DNA IN COMPETENT BACILLUS SUBTILIS. I. PROCESSING OF B. PUMILUS AND B. LICHENIFORMIS DNA IN B. SUBTILIS
Authors: te Riele Hein P J , Venema Gerard 
Published: January 2021

ABSTRACT
Competent Bacillus subtilis cells were exposed to radioactive and density labeled donor DNA extracted from B. pumilus and B. licheniformis. The DNA from these strains hybridized with B. subtilis DNA in vitro at a rate of 24% and 11%, respectively. After entry the vast majority of heterologous DNA was found at the single-strand DNA position in CsCl gradients, and was gradually degraded during incubation. Much less donor DNA than expected from the hybridization values participated in the formation of the donorrecipient complex (DRC). By subjecting the heterologous DRC to sonication and alkaline CsCl gradient centrifugation, it was established that the DRC consisted of three components: (1) recipient DNA in which breakdown products of donor DNA were incorporated through DNA synthesis, (2) recipient DNA in which donor DNA was covalently integrated and (3) recipient DNA in which the donor moiety was not covalently integrated.
DOMINANT SUPPRESSORS OF A MUSCLE MUTANT DEFINE AN ESSENTIAL GENE OF CAENORHABDITIS ELEGANS
Authors: Greenwald Iva S , Horvitz H Robert 
Published: January 2021

ABSTRACT
The sup-11 I locus of C. elegans was defined by rare dominant suppressors of unc-93(e1500) III, a mutation that affects muscle structure. All ten of these dominant suppressors have a recessive "scrawny" phenotype. Two additional classes of sup-11 alleles were identified. One class, null alleles, was obtained by reversion of the dominant suppressor activity. These null alleles are recessive embryonic lethals, indicating that sup-11 is an essential gene. Members of the second class, rare semidominant revertants of the "scrawny" phenotype, are partial suppressors of unc-93(e1500). The genetic properties of the dominant suppressor mutations suggest that they are rare missense mutations that confer a novel activity to the sup-11 protein. We consider some of the ways that sup-11 alleles might suppress unc-93(e1500), including the possibilities that the altered sup-11 proteins restore function to a protein complex or are modified products of a gene that is a member of an unc-93 gene family.
ASYMMETRIC EFFECTS OF DELETIONS AND SUBSTITUTIONS ON HIGH NEGATIVE INTERFERENCE IN COLIPHAGE LAMBDA
Authors: Makin G J Vance , Szybalski W , Blattner F R 
Published: January 2021

ABSTRACT
Experiments have been performed to help clarify the role of nonhomologies in phage λ recombination. Three-factor crosses were carried out, and the frequencies of single and double recombinants in the two adjoining intervals were compared when the central marker was either a double point mutation (v1v3) or deletion (rex-cI deletion) or nonhomologous substitution (imm434). In all cases the lefthand marker was a bio substitution (Fec- phenotype, which does not permit plating on recA -), and the righthand marker was an amber mutation in gene O. Experiments were performed in all four possible arrangements of the central and rightward markers, while selecting for the Fec+ phenotype on the recA - host. As anticipated, high negative interference (HNI) was observed with point mutations, but when the central marker was a substitution nonhomology, HNI was reduced about tenfold. Surprisingly, when the central marker was a simple deletion, a dramatic asymmetry in results was observed, with HNI being exhibited only when the central deletion marker was acquired by the double recombinant. These results indicate that under normal conditions (red +, gam +, rec +) and with noninhibited DNA replication, recombination in coliphage λ entails a highly asymmetric step that could be at the level of strand transfer or mismatch repair.
FRAMESHIFT SUPPRESSION IN SACCHAROMYCES CEREVISIAE. V. ISOLATION AND GENETIC PROPERTIES OF NONGROUP-SPECIFIC SUPPRESSORS
Authors: Culbertson Michael R , Gaber Richard F , Cummins Claudia M 
Published: January 2021

ABSTRACT
Two classes of frameshift suppressors distributed at 22 different loci were identified in previous studies in the yeast Saccharomyces cerevisiae. These suppressors exhibited allele-specific suppression of +1 G:C insertion mutations in either glycine or proline codons, designated as group II and group III frameshift mutations, respectively. Genes corresponding to representative suppressors of each group have been shown to encode altered glycine or proline tRNAs containing four base anticodons.—This communication reports the existence of a third class of frameshift suppressor that exhibits a wider range in specificity of suppression. The suppressors map at three loci, suf12, suf13, and suf14, which are located on chromosomes IV, XV, and XIV, respectively. The phenotypes of these suppressors suggest that suppression may be mediated by genes other than those encoding the primary structure of glycine or proline tRNAs.
THE GENETICS OF A SMALL AUTOSOMAL REGION OF DROSOPHILA MELANOGASTER, INCLUDING THE STRUCTURAL GENE FOR ALCOHOL DEHYDROGENASE. V. CHARACTERIZATION OF X-RAY-INDUCED Adh NULL MUTATIONS
Authors: Ashburner M , Aaron C S , Tsubota S 
Published: January 2021

ABSTRACT
Of 31 X-ray-induced and 2 spontaneous Adh null mutations selected for resistance to pentenol (Aaron 1979), 21 are deletions, including Adh and one or more neighboring loci. By contrast, none of 13 EMS-induced Adhn mutations are deletions. On average, the size of these X-ray-induced deletions is shorter than that of 12 formaldehyde-induced Adhn deletions (O'Donnell, Mandell, Krauss and Sofer 1977). Both the X-ray- and formaldehyde-induced deletions show a nonrandom distribution of break points in region 34D to 35D of chromosome arm 2L. Some of the deletions display particular genetic properties associated with one of their end points.
MARKER-DEPENDENT RECOMBINATION IN T4 BACTERIOPHAGE. II. THE EVALUATION OF MISMATCH REPAIRABILITIES IN CROSSES WITHIN INDICATOR DISTANCES
Authors: Shcherbakov V P , Plugina L A , Kudryashova E A , Efremova O I , Sizova S T , Toompuu Oleg G 
Published: January 2021

ABSTRACT
The contribution of mismatch repair to genetic recombination in T4 phage has been evaluated by three independent approaches: (1) testing for non-additivity of recombinant frequencies; (2) measurements of double exchange frequencies in three-factor crosses: (3) comparisons of recombination abilities of mutations occupying the same site. Quantitative agreement among the results of these approaches suggests that within distances much less than the mean length of hybrid regions, mismatch repair accounts perfectly for high negative interference as measured in three-factor crosses and as manifested by non-additivity in two-factor crosses. The mismatch repair mechanism readily recognizes only particular mismatches, the repair frequency being dependent on the base sequence in both strands of the mismatched region.
SPINELESS-ARISTAPEDIA: A HOMEOTIC GENE THAT DOES NOT CONTROL THE DEVELOPMENT OF SPECIFIC COMPARTMENTS IN DROSOPHILA
Authors: Struhl Gary 
Published: January 2021

ABSTRACT
A two-step screen for isolating null mutations of the spineless-aristapedia locus has been performed, and several amorphic mutations, as well as a small deficiency, have been obtained. With the exception of the deficiency, which deletes genes required for viability on either side of the spineless-aristapedia locus, these mutations result in a transformation of only the distal antenna into distal leg, thereby indicating that the spineless-aristapedia gene is required for specifying antennal as opposed to leg development in only the distal portion of the antenna. Because this distal region does not appear to be a developmental compartment, it is probable that the spineless-aristapedia gene, unlike several other homeotic genes, is required for maintaining the correct determined state in a population of cells defined by their relative position, not by their ancestry.
THE NOTCH LOCUS OF DROSOPHILA HYDEI: ALLELES, PHENOTYPES AND FUNCTIONAL ORGANIZATION
Authors: Van Breugel F M A , Langhout B Van Zijll 
Published: January 2021

ABSTRACT
The Notch (N) locus of Drosophila hydei and a series of its alleles and phenotypes are described. Some models are discussed to explain the opposite effects of some alleles on the structure of the wing, the neomorphic action of NAx over typical N alleles and the interaction with the mutation Costal-nick (Cnk).
DENSITY-DEPENDENT SELECTION INCORPORATING INTRASPECIFIC COMPETITION. II. A DIPLOID MODEL
Authors: Asmussen Marjorie A 
Published: January 2021

ABSTRACT
A diploid model is introduced and analyzed in which intraspecific competition is incorporated within the context of density-regulated selection. It is assumed that each genotype has a unique carrying capacity corresponding to the equilibrium population size when only that type is present. Each genotypic fitness at a single diallelic autosomal locus is a decreasing function of a distinctive effective population size perceived as a result of intraspecific competition. The resulting fitnesses are both density and frequency dependent with selective advantage determined by a balance between genotypic carrying capacity and sensitivity to intraspecific competition. A major finding is that intergenotypic interactions may allow genetic variation to be more easily maintained than in the corresponding model of purely density-dependent selection. In addition, numerical study confirms the possible existence of multiple interior equilibria and that neither overdominance in fitness nor carrying capacity is necessary for stability. The magnitude of the equilibrium population size and optimization principles are also discussed.
DOSAGE COMPENSATION IN DROSOPHILA: NADP-ENZYME ACTIVITIES AND CROSS-REACTING MATERIAL
Authors: Williamson John H , Bentley Michael M 
Published: January 2021

ABSTRACT
The relationships between gene dosage, enzyme activities and CRM levels have been determined for G6PD and 6PGD. Enzyme activities and CRM levels were directly proportional and increased in genotypes carrying duplications of the respective structural genes. When a duplication consisting of the distal 45% of the X chromosome was used to duplicate Pgd +, 6PGD activity and CRM increased and G6PD activity decreased. When the proximal 55% of the X chromosome was duplicated, G6PD activity and CRM increased whereas 6PGD activity and CRM levels decreased. These observations support the model of dosage compensation of X-linked genes that invokes an autosomal activator in limited concentrations for which X-linked loci compete. The distal 45% of the X chromosome, when duplicated, caused a significant increase in NADP-malic enzyme activity and CRM levels, as if a structural gene for NADP-ME is sex-linked.
FERTILITY COMPENSATION OF CORNERSTONE MALE STERILITY OF WHEAT BY RYE
Authors: Hossain M A , Driscoll C J 
Published: January 2021

ABSTRACT
The genome of rye is known to compensate for the lost male-fertility gene(s) of wheat chromosome arm 4Aα in the Cornerstone male-sterility mutant. A search for the rye chromosome(s) involved in this compensation showed that chromosomes 2R and 4R are responsible. Only the short arms of these two chromosomes are the operative ones. Chromosome arm 4RS compensates in an erratic way, whereas 2RS compensates in a full and consistent way. The entire chromosome 2R compensates less well than the 2RS telocentric which reflects an antifertility factor(s) on 2RL. This may be a specific expression of the 2R genes for poor vigor which are located on only the long arm. 2RS will be a valuable piece of chromatin for the XYZ system of producing hybrid wheat.
A GENETIC ANALYSIS OF CANDIDA ALBICANS: ISOLATION OF A WIDE VARIETY OF AUXOTROPHS AND DEMONSTRATION OF LINKAGE AND COMPLEMENTATION
Authors: Kakar S N , Partridge R M , Magee P T 
Published: January 2021

ABSTRACT
Naturally occurring strains of Candida albicans appear to be diploid and heterozygous for a limited number of nutritional markers. Additional heterozygosity can be induced by treatment with mutagens; nitrous acid alone or in combination with UV is a potent mutagen in terms of both efficacy and efficiency in the production of a wide variety of mutations. Spheroplast fusion followed by regeneration on selective media revealed complementation among four histidine-requiring mutants analyzed. Some of the fusion products appeared to be stable prototrophs, whereas in others several kinds of segregants resulted, apparently due to chromosomal or nuclear elimination. The results are suggestive of both heterokaryosis as well as nuclear fusion. The procedures described can be successfully used for generating new mutants and studying allelism. Three sets of linkage relationships have been derived from evidence provided by concomitant appearance or cosegragation of several auxotrophic markers.
THE INTERACTION OF cos WITH CHI IS SEPARABLE FROM DNA PACKAGING IN recA-recBC-MEDIATED RECOMBINATION OF BACTERIOPHAGE LAMBDA
Authors: Kobayashi Ichizo , Stahl Mary M , Leach David , Stahl Franklin W 
Published: January 2021

ABSTRACT
Chi (5′-GCTGGTGG) is a recombinator in RecA- RecBC-mediated recombination in Escherichia coli. In bacteriophage λ vegetative recombination, Chi is fully active only when it is correctly oriented with respect to cos, the site that defines the ends of the packaged chromosome. Here we demonstrate that packaging from cos is not necessary for this cos-Chi interaction. Our evidence suggests that correctly oriented cos is an activator of Chi. cos, as an activator, is (1) dominant over cos -, (2) active opposite an extensive heterology, (3) able to interact with Chi only when on the same (cis) chromosome, and (4) able to interact with Chi at distances as far as ≥ 20 kb. Thus, cos and Chi form a two-component recombinator system for general recombination. cos may serve as an asymmetric entry site for a recombination enzyme that recognizes Chi in an asymmetric way.
RECOMBINATION IN THE VICINITY OF INSERTIONS OF TRANSPOSON Tn5 IN MYXOCOCCUS XANTHUS
Authors: Sodergren Erica , Cheng Yvonne , Avery Leon , Kaiser Dale 
Published: January 2021

ABSTRACT
To test genetic recombination in the vicinity of insertions of the transposon Tn5, crosses were performed by transduction between M. xanthus strains carrying different insertions of Tn5. One member of each pair carried resistance to kanamycin (Tn5-Km); the other carried resistance to tetracycline (Tn5-Tc). The distance between each pair of Tn5 insertions was also measured by restriction mapping. The physical distance corresponding to each recombination frequency was calculated from the transductional linkage and compared with distance on the restriction map. A good correspondence between the two measures of distance was obtained for a pair of Tn5 insertions near the cglB locus and for another pair near the mgl locus. Correspondence between the two measurements of distance, the observed allelic behavior of Tn5-Km and Tn5-Tc at the same locus and the finding of the same frequencies of recombinants in reciprocal crosses implied that recombination in the vicinity of Tn5 was normal.
Analytical Methodologies for the Characterization and Analysis of the Parent Compound and Phase I Metabolites of 4F-MDMB-BICA in Human Microsome, Urine and Blood Samples
Authors: Körmöczi Tímea , Sija Éva , Institóris László , Kereszty Éva M , Ilisz István , Berkecz Róbert 
Published: January 2021

Abstract
4F-MDMB-BICA is one of the most dangerous new illicit synthetic cannabinoids (SCs) in 2020. Consumption of 4F-MDMB-BICA has been associated with a number of death cases and related serious adverse health effects in Hungary. Therefore, the use of reliable analytical methods to confirm the intake of 4F-MDMB-BICA is an important issue in forensic practice. Besides the detection of the parent compounds of SCs, the screening of their metabolites provides a reliable confirmation of their consumption, in particular, when the parent compound is under the limit of detection. To the best of our knowledge, this is the first report describing the identification of metabolites of 4F-MDMD-BICA after treatment with pooled human liver microsome (pHLM) and in human urine and blood samples using the combination of data obtained by comprehensive ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC–HRMS) and semi-targeted UHPLC–HRMS-MS methods. Finally, our routine UHPLC coupled with triple-quadrupole tandem low-resolution mass spectrometry method for screening urine and blood SCs was improved by adding the parent compound and selected main biomarkers of 4F-MDMD-BICA. From the pHLM assay of 4F-MDMD-BICA, 30 phase I metabolites were characterized and structural information thus obtained provided the basis of further identification of in vivo urine and blood metabolites. Overall, 20 urinary and 13 blood in vivo metabolites of 4F-MDMD-BICA have been identified by the investigation of five authentic urine and two blood samples. The ester hydrolysis metabolite was selected as a reliable primary biomarker in urine and blood. As secondary targets, urinary mono-hydroxylation metabolite and ester hydrolysis + dehydrogenation metabolite in blood were recommended due to their abundance and selectivity. Overall, the main phase I metabolites of 4F-MDMD-BICA were successfully characterized, and our routine analytical method with related sample preparation procedure provided a reliable analytical tool for screening both 4F-MDMD-BICA and its selected metabolites in urine and blood samples.
What Are the Implications of Applying Equipoise in Planning Citizens Basic Income Pilots in Scotland?
Authors: McCartney Gerry , Craig Neil , Myers Fiona , Hearty Wendy , Barclay Coryn 
Published: January 2021

Abstract
We have been asked to consider the feasibility of piloting a Citizens’ Basic Income (CBI): a basic, unconditional, universal, individual, regular payment that would replace aspects of social security and be introduced alongside changes to taxes. Piloting and evaluating a CBI as a Cluster Randomized Control Trial (RCT) raises the question of whether intervention and comparison groups would be in equipoise, and thus whether randomization would be ethical. We believe that most researchers would accept that additional income, or reduced conditions on receiving income would be likely to improve health, especially at lower income levels. However, there are genuine uncertainties about the impacts on other outcomes, and CBI as a mechanism of providing income. There is also less consensus amongst civil servants and politicians about the impacts on health, and substantial disagreement about whether these would outweigh other impacts. We believe that an RCT is ethical because of these uncertainties. We also argue that the principle of equipoise should apply to randomized and non-randomized trials; that randomization is a fairer means of allocating to intervention and comparison groups; and that there is an ethical case for experimentation to generate higher-quality evidence for policymaking that may otherwise do harm.
Analgesic efficacy of two approaches of ultrasound-guided quadratus lumborum block for laparoscopic renal surgery
Authors: Li Xue , Xu Zhen-Zhen , Li Yu-Ting , Lin Zeng-Mao , Liu Zheng-Ye , Wang Dong-Xin 
Published: January 2021

BACKGROUND
Moderate-to-severe pain exists in the early postoperative period after laparoscopic renal surgery.

OBJECTIVE
We investigated the analgesic effect of quadratus lumborum block (QLB) via two approaches in patients undergoing laparoscopic renal nephrectomy.

DESIGN
A randomised controlled trial.

SETTING
An academic tertiary care hospital in Beijing, China.

PARTICIPANTS
Ninety-six patients aged 18 to 70 years who were scheduled for elective laparoscopic radical or partial nephrectomy.

INTERVENTIONS
Eligible patients were allocated randomly to a control group (no block), lateral QLB group or posterior QLB group. Ultrasound-guided QLB was performed via either the lateral or posterior approach with 30 ml of 0.4% ropivacaine before surgery.

MAIN OUTCOME MEASURES
The primary outcome was sufentanil equivalent consumption within 24 h. Among secondary outcomes, somatic and visceral pain intensity at rest and on coughing were assessed with a numerical rating scale (where 0 = no pain and 10 = the worst pain) until 24 h postoperatively.

RESULTS
Sufentanil equivalent consumption did not differ among the three groups (118 ± 36 μg in the control group, 115 ± 47 μg in the lateral QLB group and 119 ± 40 μg in the posterior QLB group; P = 0.955). However, both somatic (lateral QLB vs. control, median difference −1, P < 0.001 at rest and −2 to −1, P < 0.001 on coughing; posterior QLB vs. control, −1, P < 0.001 at rest and −2 to −1, P < 0.001 on coughing) and visceral pain scores (lateral QLB vs. control, −1 to 0, P < 0.001 at rest and −1, P < 0.001 on coughing; posterior QLB vs. control, −1 to 0, P < 0.001 at rest and −2 to −1, P < 0.001 on coughing) were significantly lower in the two QLB groups than in the control group.

CONCLUSION
For patients undergoing laparoscopic renal surgery, a pre-operative single-shot QLB via the lateral or posterior approach did not decrease opioid consumption, but improved analgesia for up to 24 h after surgery.

TRIAL REGISTRATION

www.chictr.org.cn identifier: ChiCTR1800019883.
Early and surgical menopause associated with higher Framingham Risk Scores for cardiovascular disease in the Canadian Longitudinal Study on Aging
Authors: Price Madison A. , Alvarado Beatriz E. , Rosendaal Nicole T.A. , Câmara Saionara M.A. , Pirkle Catherine M. , Velez Maria P. 
Published: January 2021

Abstract

Objective:
In women, the risk of cardiovascular disease (CVD) is higher in the postmenopausal period. The effect that menopausal type, natural versus surgical, or the age at natural menopause has on CVD needs further investigation. To this end, we assessed the association between menopausal type and timing and the 10-year office-based Framingham Risk Score (FRS) in women from the Canadian Longitudinal Study on Aging.

Methods:
We included women aged 45 to 85 years from the Canadian Longitudinal Study on Aging Comprehensive cohort of seven Canadian provinces who were menopausal at the time of recruitment and had no prior CVD. Poisson regressions were used to evaluate the association between menopausal characteristics and the FRS. Natural menopause was defined as the cessation of menstrual periods for at least 1 year in women with no history of hysterectomy. Surgical menopause was defined as hysterectomy with or without oophorectomy prior to natural menopause. As main covariates, we examined age, education, province of residency, and hormone therapy.

Results:
A total of 10,090 women (8,200 natural menopausal and 1,890 surgical menopausal) were eligible for the study. In the multivariable model, surgical menopause was associated with a higher mean FRS compared with natural menopause (CVD risk 12.4% vs 10.8%, P < 0.001). Compared with women with age at natural menopause from 50 to 54 years (CVD risk 10.2%), natural menopause before age 40, 40 to 44, or 45 to 49 had a higher CVD risk (12.2%, 11.4%, and 10.6%, respectively, P < 0.001).

Conclusions:
Our study supports an association between menopausal type and timing on CVD risk prediction and highlights the need to be judicious about surgical menopause. Preventative interventions for CVD should be considered in surgical menopausal women and women with an age at natural menopause less than 45 years.

Video Summary:

http://links.lww.com/MENO/A701.