bluuebunny/crossref_metadata_2025 huggingface dataset:
THE DILEMMA OF SCIENCE AND MORALS
Authors: Stent Gunther S
Published: January 2021

The conflicts between science and morals which still continue to arise despite the apparent hegemony of atheistic scientism over traditional Judeo-Christianity in the twentieth century reflect a basic contradiction in the metaphysical foundation of Western lives. As was set forth by Machiavelli, the contradiction inherent in Western ethics is that it is based on the simultaneous belief in both objectively valid moral truths and purely relative values of communal purpose. The achievements of twentieth century science have intensified these contradictions. Modern physics has put in question the validity of its own metaphysical basis, namely the belief in Natural Law, and modern biology has been unable to come to terms with the Cartesian dualism of body and soul. By contrast, Chinese lives are comparatively free of these contradictions, being founded on the philosophies of Confucianism and Taoism, to which the concepts of objectively valid truth or Natural Law are foreign. Recent developments in Western attitudes regarding science and morals can be interpreted as a movement away from the traditional belief in absolute truths towards a Chinese relativism.
SOME ACRIDINE-RESISTANT MUTATIONS OF BACTERIOPHAGE T4D
Authors: Rappaport Harriet , Russel Marjorie , Susman Millard
Published: January 2021

Three new 9-aminoacridine (9AA) resistant mutations of bacteriophage T4D have been isolated and characterized. Two of the mutations, rs and rc, have identical patterns of acridine resistance, but they map on opposite sides of the rII region. In addition, rs has an effect on the plaque morphology of r mutations, whereas rc does not. The third mutation, ama, maps very close to rs but exhibits a different pattern of resistance to 9AA. None of the three is resistant to acridines by virtue of reduced permeability. Taken together with other mutations that have been previously characterized, these new mutations permit us to set the minimum number of acridine-sensitive processes in T4 development at four.
A FINE STRUCTURE MAP OF THE SALMONELLA HISTIDINE OPERATOR-PROMOTER
Authors: Ely Bert , Fankhauser David B , Hartman Philip E
Published: January 2021

Over 100 regulatory mutations linked to the histidine (his) operon of S. typhimurium have been isolated. They all map in a region estimated to be several hundred base pairs in length located at one end of the his operon ("the hisO region"). The mutations are located at sixteen recombinationally separable sites or are deletions encompassing several sites. Data obtained from pairs of reciprocal three-point tests show that "constitutive" (high enzyme levels) and "promoter-like" (low enzyme levels) hisO mutations are interspersed on the genetic map. In a few crosses, recombination was not observed to occur between markers shown to occupy different sites based on behavior in other recombination tests.
EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON RESPONSES TO DISRUPTIVE SELECTION IN DROSOPHILA MELANOGASTER
Authors: Barker J S F , Karlsson L J E
Published: January 2021

Disruptive selection for sternopleural bristle number with opportunity for random mating was done in the four treatment combinations of two population sizes (40 pairs and 8 pairs of selected parents) and two selection intensities (1 in 40 and 1 in 2). In each generation, matings among selected parents were observed in a mating chamber, and progeny collected separately from each female parent. In the high number, high selection intensity treatment, divergence between the high and low parts ceased about generation 11. The isolation index increased rapidly to generation 3, but then fluctuated to termination of the population at generation 17. The overall isolation index was significant, indicating a real tendency to assortative mating. The failure of the isolation index to increase after generation 3 was attributed to lower average mating fitness of high males (due to inbreeding) and reduced receptivity of low females (due to a homozygous lethal gene with a large effect on sternopleural bristle number in heterozygotes). In the two low number treatments, isolation indices fluctuated from generation to generation with no obvious trends, and none of the overall isolation indices were significantly different from zero. The high number, low selection intensity treatment showed very little divergence, and one of the replicates showed, in contrast with expectation and the high number, high selection intensity treatment, a significant tendency to disassortative mating. Intense disruptive selection may lead to assortative mating.
THE EVOLUTIONARY ADVANTAGE OF RECOMBINATION
Authors: Felsenstein Joseph
Published: January 2021

The controversy over the evolutionary advantage of recombination initially discovered by Fisher and by Muller is reviewed. Those authors whose models had finite-population effects found an advantage of recombination, and those whose models had infinite populations found none. The advantage of recombination is that it breaks down random linkage disequilibrium generated by genetic drift. Hill and Robertson found that the average effect of this randomly-generated linkage disequilibrium was to cause linked loci to interfere with each other's response to selection, even where there was no gene interaction between the loci. This effect is shown to be identical to the original argument of Fisher and Muller. It also predicts the "ratchet mechanism" discovered by Muller, who pointed out that deleterious mutants would more readily increase in a population without recombination. Computer simulations of substitution of favorable mutants and of the long-term increase of deleterious mutants verified the essential correctness of the original Fisher-Muller argument and the reality of the Muller ratchet mechanism. It is argued that these constitute an intrinsic advantage of recombination capable of accounting for its persistence in the face of selection for tighter linkage between interacting polymorphisms, and possibly capable of accounting for its origin.
THE TWO-LOCUS MODEL WITH SEX DIFFERENCES IN RECOMBINATION
Authors: Strobeck Curtis
Published: January 2021

The criteria for stability of the equilibrium with D=0 are obtained for the two locus model with multiplicative or symmetric fitnesses when the recombination values in males and females are different. It is shown that if r is defined to be equal to the average of the recombination values in males and females, then the criteria are exactly the same as in the standard two locus model.—The equilibrium values with D≠0 are obtained for the symmetric fitness model. At this equilibrium, the absolute value of D is always greater (for the same average recombination value) if the recombination values in males and females differ than if they are equal.
RECIPIENT GENE DUPLICATION DURING GENERALIZED TRANSDUCTION
Authors: Stodolsky M
Published: January 2021

An Hfrl3 ΔProA-lac  deletion recipient, -ΔproA-lac-F-purE+-, has been utilized in a study of the origins of duplications formed during chromosome fragment integration. Among the Pro-Lac+ transductants, some have duplications spanning the F locus. These transductants are, or segregate, strains with F' episomes carrying genes of the duplication. Some of the duplications include purE+, a gene which is not coinherited with lac+ during bacteriophage P1- mediated transduction. Thus recipient genes have been duplicated during recombinant formation. Crossing-over models including replication steps provide a basis for explaining the duplication process.
GENETIC LIMITS OF THE XANTHINE DEHYDROGENASE STRUCTURAL ELEMENT WITHIN THE ROSY LOCUS IN DROSOPHILA MELANOGASTER
Authors: Gelbart William M , McCarron Margaret , Pandey Janardan , Chovnick Arthur
Published: January 2021

Experiments are described that provide an opportunity to estimate the genetic limits of the structural (amino acid coding) portion of the rosy locus (3: 52.0) in Drosophila melanogaster, which controls the enzyme, xanthine dehydrogenase (XDH) . This is accomplished by mapping experiments which localize sites responsible for electrophoretic variation in the enzyme on the known genetic map of null-XDH rosy mutants. Electrophoretic sites are distributed along a large portion of the null mutant map. A cis-trans test involving electrophoretic variants in the left- and right-hand portions of the map leads to the conclusion that the entire region between these variants is also structural. Hence most, if not all, of the null mutant map of the rosy locus contains structural information for the amino acid sequence of the XDH polypeptide. Consideration is given to the significance of the present results for the general problem of gene organization in higher eukaryotes.
REPAIR OF X-IRRADIATION DAMAGE IN TRIBOLIUM CASTANEUM STRAINS SELECTED FOR DIFFERENCES IN DEVELOPMENTAL RATES
Authors: Soliman M Hani
Published: January 2021

Lines previously selected for different speed of development were found to differ in their spontaneous and induced wing abnormalities after single exposure to X-ray (10 KR) in Tribolium castaneum at 33° and 70% relative humidity. At the time of irradiation the mean developmental time (from egg to first day pupa) was 16.9, 18.8, 22.8 and 18.4 days for fast, intermediate, slow and unselected lines, respectively. There was no difference between males and females in their responses. The spontaneous rate (angular values) of wing abnormalities was 5.3%, 11.2%, 3.5% and 7.2%, and the corresponding induced values were 16.7%, 20.5%, 11.7% and 25.2% for fast, intermediate, slow and unselected lines, respectively. The difference between the spontaneous (due to selection) and the induced (due to selection and irradiation) rates indicates that slowing down development will probably increase the efficiency of the repair of the irradiation damage. This difference (angular values) was 11.4%, 9.4% and 8.1% for fast, intermediate and slow lines, respectively. Increasing developmental time by one day resulted in repairing 0.56% of the radiation damage. These results indicate that both the genetic and the developmental state of the line influence both induction and repair of the X-irradiation damage. The relationship between development, cell cycle, protein synthesis and repair is discussed.
THE BACILLUS SUBTILIS GENOME: REPLICATION-ORDER AND MAP-POSITION DISCREPANCIES—EVIDENCE FOR A SECOND ORIGIN
Authors: Copeland James C
Published: January 2021

Replication order to map position discrepancies have been documented in B. subtilis. The discrepancies were found to occur whenever the genome of B. subtilis was replicated under a variety of physiological conditions and in both 168 and W23 strains. The earliest replicating marker involved in these discrepancies was thr versus purB and aroA versus recA. A detailed linkage analysis of the ura to argA region was consistent with its being a continuous linkage group. This led to the conclusion that an origin for new starts at replication exists between recA and aroA.
MITOCHONDRIAL GENETICS VII. ALLELISM AND MAPPING STUDIES OF RIBOSOMAL MUTANTS RESISTANT TO CHLORAMPHENICOL, ERYTHROMYCIN AND SPIRAMYCIN IN S. CEREVISIAE
Authors: Netter Pierre , Petrochilo Eric , Slonimski Piotr P , Bolotin-Fukuhara Monique , Coen Dario , Deutsch Jean , Dujon Bernard
Published: January 2021

We have isolated 15 spontaneous mutants resistant to one or several antibiotics like chloramphenicol, erythromycin and spiramycin. We have shown by several criteria that all of them result from mutations localized in the mitochondrial DNA. The mutations have been mapped by allelism tests and by two- and three-factor crosses involving various configurations of resistant and sensitive alleles associated in cis or in trans with the mitochondrial locus ω which governs the polarity of genetic recombination. A general mapping procedure based on results of heterosexual (ω+ × ω-) crosses and applicable to mutations localized in the polar segment is described and shown to be more resolving than that based on results of homosexual crosses. Mutations fall into three loci which are all linked and map in the following order: ω-RI-RII-RIII. The first locus is very tightly linked with ω while the second is less linked to the first. Mutations of similar resistance phenotype can belong to different loci and different phenotypes to the same locus. Mutations confer antibiotic resistance on isolated mitochondrial ribosomel and delineate a ribosomal segment of the mitochondrial DNA. Homo- and hetero-sexual crosses between mutants of the ribosomal segment and those belonging to the genetically unlinked ATPase locus, OI, have been performed in various allele configurations. The polarity of recombination between RI, RII, RIII and OI decreases as a function of the distance of the R locus from the ω locus rather than as a function of the distance of the R locus from the OI locus.
DOSAGE COMPENSATION OF GENES ON THE LEFT AND RIGHT ARMS OF THE X CHROMOSOME OF DROSOPHILA PSEUDOOBSCURA AND DROSOPHILA WILLISTONI
Authors: Abraham Irene , Lucchesi John C
Published: January 2021

We have investigated the occurrence of dosage compensation in D. willistoni and D. pseudoobscura, two species whose X chromosome is metacentric with one arm homologous to the X and the other homologous to the left arm of chromosome 3 of D. melanogaster. Crude extracts were assayed for isocitrate dehydrogenase (XR), glucose-6-phosphate dehydrogenase (XL?), 6-phosphogluconate dehydrogenase (XL?), and α-glycerophosphate dehydrogenase (chromosome 2) in D. willistoni, and for esterase-5 (XR), glucose-6-phosphate dehydrogenase (XL?), 6-phosphogluconate dehydrogenase (XL?) and amylase (chromosome 3) in D. pseudoobscura. Our results indicate that a mechanism for dosage compensation is operative in both arms of the X chromosome of these two species.
VARIATION OF SPONTANEOUS OCCURRENCE RATES OF CHROMOSOMAL ABERRATIONS IN THE SECOND CHROMOSOMES OF DROSOPHILA MELANOGASTER
Authors: Yamaguchi Osamu , Mukai Terumi
Published: January 2021

After accumulating mutations by the aid of marked inversions, spontaneous occurrence rates of chromosome aberrations were estimated for 1148 chromosome lines that originated from five stem line second chromosomes of Drosophila melanogaster. In chromosome lines originating from three stem chromosomes (CH, PQ, and RT), mutations were accumulated for 7550, 7252, and 7256 chromosome generations, respectively, but no structural change was detected. For the chromosome lines that originated from the other two stem chromosomes, the situation was different: Twenty aberrations (19 paracentric inversions and 1 translocation between the second and the third chromosomes) during 45990 chromosome generations took place in the 500 chromosome lines derived from stem line chromosome (AW), and 92 aberrations (83 paracentric inversions, 6 pericentric inversions, 2 translocations between the second and the third chromosomes and 1 transposition) arose during 45006 chromosome generations in the 500 chromosome lines derived from stem line chromosome (JH). For the AW group the occurrence rate becomes 0.00043 per chromosome per generation for all aberrations and 0.00041 for inversions. For the JH group the corresponding rates are 0.00204 and 0.00198, respectively.—A non-random distribution of the breakpoint on the salivary gland chromosome was observed and the breakpoints were concentrated in the regions 26, 29, 33, and 34.—The cytoplasms and the chromosomes (other than the second chromosomes) were made approximately uniform throughout the experiments. Thus, this remarkable variability in the occurrence rate is most probably due to the differences in one or more chromosomal elements on the original five stem chromosomes. The mutable chromosomes (AW and JH) appear to carry a kind of mutator factor such as hi (Ives 1950).
THE EFFECT OF LINKAGE ON THE MEAN VALUE OF INBREDS DERIVED FROM A RANDOM MATING POPULATION
Authors: van Aarde I M R
Published: January 2021

An expression is derived which accounts for the effect of linkage on the mean value of diploid inbreds. The original population is taken to be in Hardy-Weinberg equilibrium. It is shown that linkage will accelerate inbreeding depression. The precise nature of the acceleration is worked out for some special cases.
COMPARATIVE GENETICS OF THE T-EVEN BACTERIOPHAGES
Authors: Russell Richard L
Published: January 2021

A system of amber mutants has been developed for each of the T-even bacteriophages T2 and T6, to complement those already available in T4. In T2 these mutants identify 52 genes, of which 49 are homologous with T4 genes; in T6 they identify 45 genes, of which 42 have T4 homologs, and an additional one which is homologous to a T2 gene not yet identified in T4. In both T2 and T6, recombination between mutants is characterized by considerable negative interference, which is correctable by a mapping function designed for T4. Recombinational maps of T2 and T6 constructed with these mutants have the same gene order and nearly the same gene spacings as in T4, with the exception of the tail fiber region; T2 and T6 appear to lack a localized recombinational expansion of this region found in T4. Homologous gene products from all three phages are in general interchangeable, with the exception of those from two apparently "co-adapted" tail fiber genes, 37 and 38. The general genetic similarity of all three phages suggests that they are analogous to races of higher organisms, retaining the capacity for genetic exchange despite some clear genetic differences and some incipient isolating mechanisms.
EFFECTS OF SR-SPIROCHETE INFECTION ON DROSOPHILA MELANOGASTER CARRYING INTERSEX GENES
Authors: Miyamoto Chieko , Oishi Kugao
Published: January 2021

Three sex-transforming genes (ix, traD, and dsx) in D. melanogaster were examined with respect to possible interactions with the NSR strain of SR-spirochetes. The SR-spirochetes exerted a lethal effect on XY but not on XX individuals, regardless of whether they were phenotypically males, intersexes, or females. These results, taken together with those reported by Sakaguchi and Poulson (1963) on tra and 2X3A intersexes, both of which are resistant to the androcidal action of SR-spirochetes, support the interpretation that male susceptibility is a consequence of the single X condition.
RECOMBINATION-DEFICIENT DELETIONS IN BACTERIOPHAGE Λ AND THEIR INTERACTION WITH CHI MUTATIONS
Authors: Henderson David , Weil Jon
Published: January 2021

We have isolated a new class of deletion mutants of phage lambda that extend from the prophage attachment site, att, into the gam and cIII genes. In this respect they are similar to certain of the λpbio transducing phage, but they differ in having a low burst size and in forming minute plaques. Lytically grown stocks of the deletions contain a variable proportion of phage that produce large plaques. These have been shown to carry an additional point mutation. Similar mutations, called chi, have been described by Lam et al. (1974), who showed that they result in a hot-spot for recombination produced by the host recombination system (Rec). We show that chi mutations can occur at several sites in the lambda genome and produce a Rec-dependent increase in the burst size of the one deletion tested.—In addition to reducing burst size, the one deletion tested reduces synthesis of DNA and endolysin but increases production of serum blocking protein. A chi mutation partially restores DNA synthesis and endolysin production and reduces serum blocking protein to normal levels. Our results are consistent with the hypothesis put forward by Lam et al., that chi enhances the frequency of Rec-promoted recombination, which provides the only pathway for production of maturable DNA in a red- gam- infection. The mechanism of the differential effect on protein production is, however, unclear.—Chi mutations are found to occur in DNA other than that of λ. We show that, as has been suggested elsewhere (McMilin, Stahl and Stahl 1974), the λpbio transducing phages carry a chi mutation within the E. coli DNA substitution. A chi mutation also arose in a new substitution of unknown origin isolated in the course of this work.
AN ANALYSIS OF THE MODE OF GENE ACTION AFFECTING PUPA WEIGHT IN TRIBOLIUM CASTANEUM
Authors: Goodwill R
Published: January 2021

Triple-testcross experiments (Kearsey and Jinks 1968) were employed to investigate the mode of gene action affecting pupa weight in Tribolium castaneum. Their experimental design involves two inbred lines, the F1 progeny and a segregating population derived from the cross of the inbred lines. In the present experiments, four segregating populations were used. These populations included the F2 generation, a select line (SEL) and two relaxed select lines (RSI and RSII). In addition, all possible reciprocal crosses were made among the RSI, RSII, and SEL populations. It was observed that: (1) additive, dominant and epistatic gene effects all made significant contributions to the pupa weight of the progeny from all four segregating populations; (2) there was no evidence of either accumulation of epistasis as a result of selection in the SEL population or decline in epistasis as a result of removing selection pressure from the RSI and RSII populations; and (3) significant negative heterosis and maternal effects contributed to the pupa weight of the crossbred progeny of the RSI, RSII and SEL populations.
GEOGRAPHICAL DISTRIBUTION OF TWELVE TRANSFERRIN ALLELES IN BLACK RATS OF ASIA AND OCEANIA
Authors: Moriwaki Kazuo , Kato Hatao , Imai Hirotami , Tsuchiya Kimiyuki , Yosida Tosihide
Published: January 2021

About 450 black rats (Rattus rattus) were collected from 25 localities in Asia and Oceania. Their serum transferrins were analyzed by a newly developed thin layer acrylamide gel electrophoresis accompanied with acrinol pretreatment, exhibiting 12 transferrin bands. Generally, Asian type rats (2N=42) had fast-moving transferrins (R-series), Ceylon type (2N=40) moderately moving ones and Oceanian type (2N=38) slowly moving ones (C-series). Exceptionally, in northern India and Pakistan all Asian-type rats had C-series Tf. The possibility that divergence of R-series Tf and C-series Tf had preceded the karyotypic differentiation from 42 to 38 is proposed. In combination with the previous molecular data, the time of the divergence is roughly estimated between the order of a million years and ten thousand years.
STUDIES OF MUTATIONS IN T4 CONTROL GENES 33 AND 55
Authors: Horvitz H Robert
Published: January 2021

Available mutations in transcriptional control genes 33 and 55 of coliphage T4 have been examined. By complementation analysis and map position, 15 mutants (13 in T4D, 2 in T4B) have been shown to lie in gene 33 and 6 (5 in T4D, 1 in T4B) in gene 55. According to patterns of suppression and recombination, these mutants define three distinct amber sites in gene 33 and also three distinct amber sites in gene 55. All of these mutations are true amber mutations, in apparent contrast to some traditional T4 "amber" mutants which grow in su+  E. coli CR63 but not in su-  E. coli B because of a strain difference other than the su+ determinant. Evidence is presented that, contrary to previous suggestions (Bolle et al. 1968; Pulitzer and Geiduschek 1970), the gene 33 product is absolutely essential for T4 development.
A GENETIC AND BIOCHEMICAL STUDY OF HISTIDINE BIOSYNTHESIS IN MICROCOCCUS LUTEUS
Authors: Kane-Falce Caroline , Kloos Wesley E
Published: January 2021

Histidine auxotrophs of Micrococcus luteus strain ATCC 27141 were induced by treatment of the parent strain with N-methyl-N′-nitro-N-nitro-soguanidine. Auxotrophs were biochemically characterized by examining culture accumulations of histidine intermediates, using paper chromatography and the Bratton-Marshall test, and growth responses to L-histidinol. his(IG) mutants failed to accumulate Pauly-positive imidazoles; his(EAHF) mutants accumulated 5-amino-1-ribosyl-4-imidazole carboxamide; hisB mutants accumulated imidazoleglycerol; hisC mutants accumulated imidazoleacetol; hisD mutants accumulated histidinol. L-histidinol failed to stimulate the growth of hisD mutants, but did stimulate all other histidine mutants, blocked at earlier steps in the biosynthetic pathway. In addition, imidazoleglycerol phosphate dehydrase activity was assayed in representative mutants of each class. hisB mutants lacked activity for this enzyme.—Two-point, three-point, and cotransformation analyses resolved linkage relationships of histidine genes and in two gene clusters aided in determining their sequences. Histidine biosynthetic genes exist in at least four separate, unlinked regions of the chromosome. One histidine gene cluster is closely linked to a tryptophan gene cluster and appears to be contiguous in the sequence his(IG)-his(EAHF)-trpE-trpC-trpB-trpA. A second and unlinked histidine cluster has the tentative gene sequence his(EAHF)-hisB-hisC-his(EAHF). The hisD gene and an unclassified mutant site his-94 are not linked to any of the other histidine genes examined in this study or to each other.
MITOTIC CHROMOSOME LOSS IN A DISOMIC HAPLOID OF SACCHAROMYCES CEREVISIAE
Authors: Campbell D A , Fogel S , Lusnak K
Published: January 2021

Experiments designed to characterize the incidence of mitotic chromosome loss in a yeast disomic haploid were performed. The selective methods employed utilize the non-mating property of strains disomic for linkage group III and heterozygous at the mating type locus. The principal findings are: (1) The frequency of spontaneous chromosome loss in the disome is of the order 10-4 per cell; this value approximates the frequency in the same population of spontaneous mitotic exchange resulting in homozygosity at the mating type locus. (2) The recovered diploids are pure clones, and thus represent unique events in the disomic haploid. (3) Of the euploid chromosomes recovered after events leading to chromosome loss, approximately 90% retain the parental marker configuration expected from segregation alone; however, the remainder are recombinant for marker genes, and are the result of mitotic exchanges in the disome, especially in regions near the centromere. The recombinant proportion significantly exceeds that expected if chromosome loss and mitotic exchange in the disome were independent events. The data are consistent with a model proposing mitotic nondisjunction as the event responsible for chromosome loss in the disomic haploid.
ROLE OF DNA SEQUENCES IN GENETIC RECOMBINATION IN THE ISO-1-CYTOCHROME c GENE OF YEAST. I. DISCREPANCIES BETWEEN PHYSICAL DISTANCES AND GENETIC DISTANCES DETERMINED BY FIVE MAPPING PROCEDURES
Authors: Moore Carol W , Sherman Fred
Published: January 2021

Recombination rates have been examined in two-point crosses of various defined cyc1 mutants using five mapping methods. Nucleotide sequences of mutant codons were identified in previous studies from alterations in functional iso-1-cytochromes c produced by intragenic revertants. Heteroallelic diploids were analyzed for rates of mitotic recombination that occurred spontaneously and that were induced with X-rays, ultraviolet light and the near-ultraviolet light emitted by sunlamps, as well as rates of meiotic recombination that occur after sporulation. Frequencies of both mitotic and meiotic recombination do not necessarily correspond with physical distances separating altered nucleotides. The most extreme discrepancy involved two adjacent intervals of thirteen base pairs which differed approximately thirtyfold in their spontaneous and X-ray-induced recombination rates. Marked disproportions between genetic and physical distances appear to be due to the interaction of the two nucleotide sequences in the heteroallelic combination and not to the sequences of the mutant codons alone. Recombination values that were obtained by all five methods could not be used to establish the correct order of mutant sites. Relationships of the recombination rates for the various pairwise crosses are different after mitosis from those after meiosis, suggesting that these two recombinational processes are to some extent different in their dependence on particular nucleotide configurations. On the other hand, the relationships of the rates induced by UV-, sunlamp- and X-irradiation were identical or very similar. In addition to the intrinsic properties of the alleles affecting frequencies of mitotic and meiotic recombination rates, two- to threefold variations in recombination rates could be attributed to genetic backgrounds.
LETHAL EFFECTS OF LOW AND "NULL" ACTIVITY ALLELES OF 6-PHOSPHOGLUCONATE DEHYDROGENASE IN DROSOPHILA MELANOGASTER
Authors: Bewley Glenn C , Lucchesi John C
Published: January 2021

EMS-induced "null" and low activity alleles for 6-phosphogluconate dehydrogenase were characterized with respect to enzymatic activity, relative viability, fertility, and the effective lethal phase. It was determined that flies hemizygous and homozygous for the low activity allele, Pgd  -, possessed a depressed developmental rate, diminished viability, and loss of female fertility. Heterozygotes for Pgd  - and a deficiency for Pgd  + were lethal. The "null" activity allele demonstrated a lethal phenotype in both the hemizygous and homozygous condition. The effective lethal phase for the "null" allele occurs during late embryonic development (20-22 hr).
A POSSIBLE ROLE OF REPETITIOUS DNA IN RECOMBINATORY JOINING DURING CHROMOSOME REARRANGEMENT IN DROSOPHILA MELANOGASTER
Authors: Lee C S
Published: January 2021

It is postulated that certain repetitious DNA components play a role in the recombination processes during chromosome rearrangements. When the distribution of silver grain densities after the in situ hybridization of repetitious DNA (Rudkin and Tartof 1973) and the distribution of chromosome breaks due to X-irradiation (Kaufmann 1946) are compared, a strong correlation is found for the euchromatic portion of the D. melanogaster salivary X chromosome. These observations justify the postulate above that certain repetitious DNA provides homologous regions in the DNA of broken chromosome ends necessary for proper recombinatory joining.
NATURAL SELECTION AND AGE-STRUCTURED POPULATIONS
Authors: Demetrius Lloyd
Published: January 2021

This paper studies the properties of a new class of demographic parameters for age-structured populations and analyzes the effect of natural selection on these parameters. Two new demographic variables are introduced: the entropy of a population and the reproductive potential. The entropy of a population measures the variability of the contribution of the different age classes to the stationary population. The reproductive potential measures the mean of the contribution of the different age classes to the Malthusian parameter. The Malthusian parameter is precisely the difference between the entropy and the reproductive potential. The effect of these demographic variables on changes in gene frequency is discussed. The concept of entropy of a genotype is introduced and it is shown that in a random mating population in Hardy-Weinberg equilibrium and under slow selection, the rate of change of entropy is equal to the genetic variance in entropy minus the covariance in entropy and reproductive potential. This result is an information theoretic analog of Fisher's fundamental theorem of natural selection.
PARAMETERS OF MITOTIC RECOMBINATION IN MINUTE MUTANTS OF DROSOPHILA MELANOGASTER
Authors: Ferrus A
Published: January 2021

A sample of 16 Minutes, representing 12 loci distributed over all the chromosome arms and including 3 pairs of alleles and 4 deficiencies, has been studied with respect to several developmental and recombinational parameters. Cell marker mutants located in most of the chromosome arms were used to assess (1) spontaneous and X-ray-induced mitotic recombination frequencies of each Minute, and (2) clone sizes of the different cell marker clones. These parameters were analyzed both in the wing disc and in the abdominal histoblasts.—Whereas spontaneous frequencies are not affected by the presence of the Minutes studied, the different Minutes characteristically increase the frequency of recombination clones arising after X-irradiation. The recombinant clones which are M  +/M  + are significantly larger than clones in the same fly which retain the M  +/M condition. This is particularly striking in clones in the wing disc, slightly so in clones in the tergites. The occurrence of mitotic recombination in the fourth chromosome is reported for the first time.—Chaeta length and developmental delay correlates with the recombinational parameters in different ways. Possible causal interrelationships of the different traits of the Minute syndrome are discussed.
POLYALLELIC MUTATIONAL EQUILIBRIA
Authors: King Jack Lester , Ohta Tomoko
Published: January 2021

A new deterministic formulation is derived of the equilibrium between mutation and natural selection, which takes into account (a) the possibility of many allelic mutation states, (b) selection coefficients of the order of magnitude of the mutation rate and (c) the possibility of further mutation of already mutant alleles. The frequencies of classes of alleles 0, 1, 2, n mutant steps removed from the type allele are shown to form a Poisson distribution, with a mean and variance of the mutation rate divided by the coefficient of selection against each incremental mutational step. — This formulation is interpreted in terms of the expected frequencies of electromorphs, defined as classes of alleles characterized by common electrophoretic mobilities of their protein products. Electromorph frequencies are predicted to form stable unimodal distributions of relatively few phenotypic classes. Common electromorph frequencies found throughout the ranges of species with large population sizes are interpreted as being a uniquely electrophoretic phenomenon; band patterns on starch and acrylamide gels are phenotypes, not genotypes. It is predicted that individual electromorphs are highly heterogeneous with regard to amino acid sequence.
Perceived Types, Causes, and Consequences of Financial Exploitation: Narratives From Older Adults
Authors: Nguyen Annie L , Mosqueda Laura , Windisch Nikki , Weissberger Gali , Axelrod Jenna , Han S Duke
Published: January 2021

Objectives

The goal of this study was to investigate the perception of financial exploitation and its causes and consequences by older adults who have firsthand experience of being exploited.

Method

Thirty-one cognitively healthy older adult participants aged 50 or older were drawn from the Finance, Cognition, and Health in Elders Study. In-depth, one-on-one interviews were conducted. Interview transcripts were analyzed using an iterative, data-driven, thematic coding scheme and emergent themes were summarized.

Results

Categories of financial exploitation included (a) investment fraud, (b) wage theft/money owed, (c) consumer fraud, (d) imposter schemes, and (e) manipulation by a trusted person. Themes emerged around perceived causes: (a) element of trust, (b) promise of financial security, (c) lack of experience or awareness, (d) decision-making, and (e) interpersonal dynamics. Perceived consequences included negative and positive impacts around (a) finances, (b) financial/consumer behaviors (c) relationships and trust, (d) emotional impact, and (e) future outlook.

Discussion

These narratives provide important insights into perceived financial exploitation experiences.
Maximizing Home Health Aide Retention: The Impact of Control and Support on the Job
Authors: Gleason Hayley P , Miller Edward Alan
Published: January 2021

Background and Objectives

This study examined relationships between the level of control and support and home health aides (HHAs) job satisfaction and intent to leave the job.

Research Design and Methods

Data derive from a survey of 512 HHAs in Massachusetts. Logistic regression using generalized estimating equations was employed for the analysis. Dependent variables included satisfaction and intent to leave the job as a home care aide generally and satisfaction and intent to leave the job at the aide’s current agency.

Results

The findings showed that greater control and support on the job were important predictors of positive work outcomes, controlling for job demands and other covariates. The odds of HHAs being satisfied with their job as a home care aide increased with the degree of control, whereas the odds of HHAs being satisfied with their job at their current agency increased with the extent of support. Control was negatively associated with HHAs’ intent to leave the job as an aide; no relationship was found between control or support and HHAs’ intent to leave their current agency.

Discussion and Implications

The results from this study illustrate the importance for HHAs of having control and autonomy in their work, as well as the benefit of support from supervisors and the home care agency, on satisfaction and intent to leave. Expanding HHA’s ability to maintain control over their day-to-day work, as well as enhancing the supports available to them, is likely to benefit home care workers, clients, and agencies through increased retention.
Dimethyl fumarate dose-dependently increases mitochondrial gene expression and function in muscle and brain of Friedreich’s ataxia model mice
Authors: Hui Chun Kiu , Dedkova Elena N , Montgomery Claire , Cortopassi Gino
Published: January 2021

Previously we showed that dimethyl fumarate (DMF) dose-dependently increased mitochondrial gene expression and function in cells and might be considered as a therapeutic for inherited mitochondrial disease, including Friedreich’s ataxia (FA). Here we tested DMF’s ability to dose-dependently increase mitochondrial function, mitochondrial gene expression (frataxin and cytochrome oxidase protein) and mitochondrial copy number in C57BL6 wild-type mice and the FXNKD mouse model of FA. We first dosed DMF at 0–320 mg/kg in C57BL6 mice and observed significant toxicity above 160 mg/kg orally, defining the maximum tolerated dose. Oral dosing of C57BL6 mice in the range 0–160 mg/kg identified a maximum increase in aconitase activity and mitochondrial gene expression in brain and quadriceps at 110 mg/kg DMF, thus defining the maximum effective dose (MED). The MED of DMF in mice overlaps the currently approved human-equivalent doses of DMF prescribed for multiple sclerosis (480 mg/day) and psoriasis (720 mg/day). In the FXNKD mouse model of FA, which has a doxycycline-induced deficit of frataxin protein, we observed significant decreases of multiple mitochondrial parameters, including deficits in brain mitochondrial Complex 2, Complex 4 and aconitase activity, supporting the idea that frataxin deficiency reduces mitochondrial gene expression, mitochondrial functions and biogenesis. About 110 mg/kg of oral DMF rescued these enzyme activities in brain and rescued frataxin and cytochrome oxidase expression in brain, cerebellum and quadriceps muscle of the FXNKD mouse model. Taken together, these results support the idea of using fumarate-based molecules to treat FA or other mitochondrial diseases.
Evolutionary genetics of skin pigmentation in African populations
Authors: Feng Yuanqing , McQuillan Michael A , Tishkoff Sarah A
Published: January 2021

Skin color is a highly heritable human trait, and global variation in skin pigmentation has been shaped by natural selection, migration and admixture. Ethnically diverse African populations harbor extremely high levels of genetic and phenotypic diversity, and skin pigmentation varies widely across Africa. Recent genome-wide genetic studies of skin pigmentation in African populations have advanced our understanding of pigmentation biology and human evolutionary history. For example, novel roles in skin pigmentation for loci near MFSD12 and DDB1 have recently been identified in African populations. However, due to an underrepresentation of Africans in human genetic studies, there is still much to learn about the evolutionary genetics of skin pigmentation. Here, we summarize recent progress in skin pigmentation genetics in Africans and discuss the importance of including more ethnically diverse African populations in future genetic studies. In addition, we discuss methods for functional validation of adaptive variants related to skin pigmentation.
Multi-omics analyses of cognitive traits and psychiatric disorders highlight brain-dependent mechanisms
Authors: Korologou-Linden Roxanna , Leyden Genevieve M , Relton Caroline L , Richmond Rebecca C , Richardson Tom G
Published: January 2021

Integrating findings from genome-wide association studies with molecular datasets can help develop insight into the underlying functional mechanisms responsible for trait-associated genetic variants. We have applied the principles of Mendelian randomization to investigate whether brain-derived gene expression (n = 1194) may be responsible for mediating the effect of genetic variants on eight cognitive and psychological outcomes (attention-deficit hyperactivity disorder, Alzheimer’s disease, bipolar disorder, depression, intelligence, insomnia, neuroticism and schizophrenia). Transcriptome-wide analyses identified 83 genes associated with at least one outcome (PBonferroni < 6.72 × 10−6), with multiple trait colocalization also implicating changes to brain-derived DNA methylation at nine of these loci. Comparing effects between outcomes identified the evidence of enrichment, which may reflect putative causal relationships, such as an inverse relationship between genetic liability towards schizophrenia risk and cognitive ability in later life. Repeating these analyses in whole blood (n = 31 684), we replicated 58.2% of brain-derived effects (based on P < 0.05). Finally, we undertook phenome-wide evaluations at associated loci to investigate pleiotropic effects with 700 complex traits. This highlighted pleiotropic loci such as FURIN [initially implicated in schizophrenia risk (P = 1.05 × 10−7)], which had evidence of an effect on 28 other outcomes, as well as genes which may have a more specific role in disease pathogenesis [e.g. SLC12A5 which only provided evidence of an effect on depression (P = 7.13 × 10−10)]. Our results support the utility of whole blood as a valuable proxy for future studies analysing molecular datasets, but also suggest that conducting analyses in a tissue-specific manner may be more comprehensive.
Finiteness Theorems for Kac–Moody Groups over Non-archimedean Local Fields
Authors: Ali Abid
Published: January 2021

We prove the finiteness of formal analogs of the spherical function (Spherical Finiteness), the ${\textbf c}$-function (Gindikin–Karpelevich Finiteness), and obtain a formal analog of Harish-Chandra’s limit (Approximation Theorem) relating spherical and ${\textbf c}$-function in the setting of $p$-adic Kac–Moody groups. The finiteness theorems imply that the formal analog of the Gindikin–Karpelevich integral is well defined in local Kac–Moody settings. These results extend Braverman–Garland–Kazhdan–Patnaik’s affine Gindikin–Karpelevich finiteness theorems from [ 4] and provide an algebraic analog of the combinatorial results of Gaussent–Rousseau [10] and Hébert [14].
Deemed consent for organ donation: a comparison of the English and Scottish approaches
Authors: Parsons Jordan A
Published: January 2021

Deemed consent for organ donation has long been discussed as a potential solution to the shortage of organs for transplantation, with several countries having implemented it. In Great Britain, Wales was the first nation to introduce such a system, having done so in 2015. Now, the other two nations are following suit. In this paper, I compare the approaches of England and Scotland in moving to systems of deemed consent for organ donation. After outlining both sets of legislation, I focus on three points on which the two nations differ. First, the role of those close to the deceased in the consent process and the extent to which clinicians are required to consult them ahead of consent being deemed. Second, the role of government ministers in ensuring widespread public awareness. Third, the ways in which the two nations responded to the challenge of the COVID-19 pandemic in relation to the implementation of deemed consent. I conclude that on all three points, the Scottish approach is preferable.
Mixed infected laryngocoele presenting as airway obstruction: a case report
Authors: James Danielle L , Garry Stephen , Corbett Mel , Lang John
Published: January 2021

Laryngocoele is a rare entity, defined as an abnormal cystic dilatation of saccule of the laryngeal ventricle. Three types of laryngocele have been described, based on their relation to the thyrohyoid membrane: internal, external or mixed type. Symptoms are variable, including neck swelling, shortness of breath, dysphonia and fever, if the laryngocoele becomes infected. Patients may also present in extremis with airway obstruction. We present the case of a healthy 34-year-old gentleman with acute airway obstruction due to a mixed infected laryngocoele. Flexible nasoendoscopy showed a large cystic swelling arising from the laryngeal ventricle. Computed tomography of neck confirmed a right paraglottic collection extending into the ventricle and glottis, causing significant airway compromise. The patient was managed with microlaryngoscopy and cystic decompression. At outpatient follow up, he was completely asymptomatic and is currently under surveillance. Endoscopic decompression is a safe and effective initial management for mixed laryngocoele.
Contradictory Phenomenon Between Serum Separator Tube and Plasma Tube: A Case Report
Authors: Pang Lu , Xing Ying , Xing Lingsheng , Miao Linzi , An Chongwen , Li Haixia
Published: January 2021

Separator gels in blood collection tubes are used to separate serum from clotted whole blood or plasma from cells. Here we present a case of a patient with a contradictory phenomenon between the serum separator tube and the plasma tube. The serum separator tube showed mixed serum and separator gel and distinctly less serum. However, the plasma tube showed fewer cells. Laboratory study revealed an IgG level of 78.9 g/L. Serum immunofixation electrophoresis analysis identified the abnormal pattern as a dense IgG band with a corresponding dense light chain band of λ. Bone marrow smear showed 53% proplasmacytes. The patient was diagnosed with multiple myeloma. The marked hyperproteinemia, especially hyperimmunoglobulinemia, may have resulted in the density alteration of serum that was mixed or located above the separator gel. This phenomenon is also seen in patients injected with iodinated radiologic contrast media such as iohexol and in patients on hemodialysis with a concentrated sodium citrate solution.
Preparing Austere Maritime Surgical Teams for Deployment During the COVID-19 Global Pandemic: Is It Time to Change the Training Pipeline?
Authors: Vicente Diego A , Ugochukwu Obinna , Johnston Michael G , Craft Chad , Damin Virginia , Tadlock Matthew D
Published: January 2021

Introduction

Navy Medicine's Role 2 Light Maneuver (R2LM) Emergency Resuscitative Surgical Systems (ERSS) are austere surgical teams manned, trained, and equipped to provide life-saving damage control resuscitation and surgery in any environment on land or sea. Given the restrictions related to the COVID-19 pandemic, the previously established pre-deployment training pipeline for was modified to prepare a new R2LM team augmenting a Role 1 shipboard medical department.

Methods

The modified curriculum created in response to COVID-19 related restriction is compared and contrasted to the established pre-deployment R2LM ERSS curriculum. Subject Matter Experts and currently deployed R2LM members critically evaluate the two curricula.

Results

Both curricula included the team R2LM platform training and exposure to cadaver based team trauma skills training. The modified curriculum included didactics on shipboard resuscitation, anesthesia and surgery, shipboard COVID-19 management, and prolonged field care in austere maritime environments.

Conclusions

We describe Navy Medicines R2LM ERSS capability and compare and contrast the standard R2LM pre-COVID-19 curriculum to the modified curriculum. Central to both curricula, the standard R2LM platform training is important for developing and honing team dynamics, communication skills and fluid leadership; important for the successful function austere surgical teams. Several opportunities for improvement in the pre-deployment training were identified for R2LM teams augmenting shipboard Role 1 medical departments.