bluuebunny/crossref_metadata_2025 huggingface dataset:
CHI MUTATION IN A TRANSPOSON AND THE ORIENTATION-DEPENDENCE OF CHI PHENOTYPE
Authors: Yagil Ezra , Dower Nancy A , Chattoraj Dhruba , Stahl Mary , Pierson Carey , Stahl Franklin W
Published: April 2021

Chi, an element that stimulates recombination via the E. coli RecBC pathway, can arise by spontaneous mutation in the transposon Tn5. When in phage λ in one orientation, the mutant transposon confers Chi+ phenotype (large plaque and a high rate of exchange near the transposon). In the other orientation, however, the transposon does not confer Chi+ phenotype. The mobility of the transposon allows us to show that the Chi+ orientation of the mutant Tn5 is the same at different locations in λ. These include a site near gene J, one in gam at 69, one to the right of gam at 73 and several to the right of R between 95.7 and 99.5. To the right of R, the mutant transposon could be found in only one orientation, that which confers Chi+ phenotype. We speculate that the other orientation of Tn5 in that locale is lethal to λ. The orientation-dependence of Chi+ phenotype also revealed that Tn5 flip-flops in λ.
PRECISE MAPPING OF THE HOMOTHALLISM GENES HML AND HMR IN SACCHAROMYCES CEREVISIAE
Authors: Klar Amar J S , McIndoo Jean , Hicks James B , Strathern Jeffrey N
Published: April 2021

The HML and HMR loci carry unexpressed copies of MAT  a and MATα information, and a replica of that information is transposed to MAT during mating-type interchange in Saccharomyces yeasts. A negative control mechanism keeps silent the information located at the HML and HMR loci. We mapped these loci by constructing strains in which these loci are expressed. In these strains, the mating type of the segregants is dependent upon the allele at HML and HMR. This novel approach is independent of their switching function. HML is located on the left arm of chromosome III distal to his4 by about 26.8 centimorgans (cM). HMR maps on the right arm of the same chromosome distal to thr4 by about 39.8 cM and proximal to MAL2 by about 1.0 cM. The results allow the exact placement of these loci and are in accord with the observations made by Harashima and Oshima (1976).
CAENORHABDITIS ELEGANS FERTILIZATION-DEFECTIVE MUTANTS WITH ABNORMAL SPERM
Authors: Argon Yair , Ward Samuel
Published: April 2021

Seven new fertilization-defective mutants of C. elegans have been isolated and characterized; six are temperature sensitive, one is absolute and all are autosomal recessive. One mutation is in a previously described gene, while the other six define six new fer genes that appear to code for sperm-specific functions necessary for normal fertilization. In all fer mutants, both males and hermaphrodites accumulate sperm in near normal numbers. In hermaphrodites, mutant sperm contact the oocytes, but fail to fertilize them. Instead, the sperm are swept into the uterus by the passing oocytes and are expelled when oocytes are laid. Males of two fer mutants do not transfer sperm during copulation, but the other mutant males transfer sperm that fail to move to the spermatheca. Spermatozoa from fer-1 and fer-4 mutants are motility-defective in vitro as well as in vivo, and their pseudopods have an altered morphology. The period of development during which mutant hermaphrodites are temperature sensitive for fertility overlaps the time of sperm development. Some mutants are temperature sensitive throughout the entire period, and others are temperature sensitive during or just prior to spermiogenesis. In fer-4/+ and fer-7/+ males, the fertility of the mutation-bearing sperm is diminished, reducing the transmission ratio. This implies some post-meiotic expression of these genes.—This set of mutants provides a variety of functional and structural alterations in nematode sperm that should help identify and analyze gene products involved in sperm morphogenesis and motility.
ISOLATION AND GENETIC CHARACTERIZATION OF CELL-LINEAGE MUTANTS OF THE NEMATODE CAENORHABDITIS ELEGANS
Authors: Horvitz H Robert , Sulston John E
Published: April 2021

Twenty-four mutants that alter the normally invariant post-embryonic cell lineages of the nematode Caenorhabditis elegans have been isolated and genetically characterized. In some of these mutants, cell divisions fail that occur in wild-type animals; in other mutants, cells divide that do not normally do so. The mutants differ in the specificities of their defects, so that it is possible to identify mutations that affect some cell lineages but not others. These mutants define 14 complementation groups, which have been mapped. The abnormal phenotype of most of the cell-lineage mutants results from a single recessive mutation; however, the excessive cell divisions characteristic of one strain, CB1322, require the presence of two unlinked recessive mutations. All 24 cell-lineage mutants display incomplete penetrance and/or variable expressivity. Three of the mutants are suppressed by pleiotropic suppressors believed to be specific for null alleles, suggesting that their phenotypes result from the complete absence of gene activity.
TEST FOR SELECTION ON POLYMORPHIC ISOZYME GENES USING THE POPULATION CAGE METHOD
Authors: Mukai Terumi , Yamazaki Tsuneyuki
Published: April 2021

Published experimental data of several species of Drosophila using the population cage method were reexamined. The authors of these works have claimed that selection operates on polymorphic isozyme genes. Since selection coefficients (s) estimated by us for the above data, assuming overdominance, or for some cases, additivity between alleles, were too large (s > 0.1), we conclude that these experimental results do not reflect the effects of the single loci in question; rather, we suggest that careful experimentation and judgment are required for testing with the population cage method whether or not selection actually operates on single genes.
LINKAGE RELATIONSHIPS OF 19 ENZYME LOCI IN MAIZE
Authors: Goodman M M , Stuber C W , Newton K , Weissinger H H
Published: April 2021

Linkage relationships of 19 enzyme loci have been examined. The chromosomal locations of eight of these loci are formally reported for the first time in this paper. These localizations should assist in the construction of additional useful chromosome marker stocks, especially since several of these enzyme loci lie in regions that were previously poorly mapped. Six loci are on the long arm of chromosome 1. The arrangement is (centromere)—Mdh4-mmm-Pgm1-Adh1-Phi-Gdh1, with about 46% recombination between Mdh4 and Gdh1.—Linkage studies with a2 and pr have resulted in the localization of four enzyme genes to chromosome 5 with arrangement Pgm2-Mdh5-Got3-a2-(centromere)-pr-Got2. Pgm2 lies approximately 35 map units distal to a2 in a previously unmapped region of the short arm of 5, beyond ameiotic.—Approximately 23% recombination was observed between Mdh4 and Pgm1 on chromosome 1, while 17% recombination occurred between Mdh5 and Pgm2 on chromosome 5. Similarly, linkages between Idh1 and Mdh1, about 22 map units apart on chromosome 8, and between Mdh2 and Idh2, less than 5 map units apart on chromosome 6, were observed. Thus, segments of chromosomes 1 and 5 and segments of 6 and 8 may represent duplications on nonhomologous chromosomes.
DIPLOID SPORE FORMATION AND OTHER MEIOTIC EFFECTS OF TWO CELL-DIVISION-CYCLE MUTATIONS OF SACCHAROMYCES CEREVISIAE
Authors: Schild David , Byers Breck
Published: April 2021

The meiotic effects of two cell-division-cycle mutations of Saccharomyces cerevisiae (cdc5 and cdc14) have been examined. These mutations were isolated by L. H. Hartwell and his colleagues and characterized as defective in mitosis, causing a temperature-sensitive arrest in late nuclear division. When subjected to the restrictive temperature in meiosis, diploid cells homozygous for either of these mutations generally proceeded through premeiotic DNA synthesis and commitment to meiotic levels of recombination, but then arrested at a stage following spindle pole body (SPB) duplication and separation. The two SPBs lacked the interconnection by spindle microtubules typical of the complete meiosis I spindle. Challenge of these homozygotes by a semi-restrictive temperature often caused the production of asci containing two diploid spores. Genetic analysis of the viable pairs of spores revealed that each spore had become homozygous for centromere-linked markers significantly more frequently than for distal markers, indicating that the two spores each contained pairs of sister centromeres that had co-segregated in the reductional division of meiosis I. Ultrastructural analysis of the cdc5 homozygote demonstrated that these cells had completed meiosis I and formed two meiosis II spindles, but that the latter remained unusually short. This resulted in the encapsulation of both poles of each spindle within a single spore wall. These mutations therefore are defective in both meiotic divisions, as well as in the mitotic division described originally.
THE frq LOCUS IN NEUROSPORA CRASSA: A KEY ELEMENT IN CIRCADIAN CLOCK ORGANIZATION
Authors: Gardner George F , Feldman Jerry F
Published: April 2021

Four new circadian clock mutants of Neurospora crassa have been isolated that alter the period length of the circadian conidiation rhythm. Three of these are at the frq locus on linkage group VIIR, where four other clock mutants are located. In contrast to wild type, which has a period length of 21.6 hr, frq-6 has a period length of 19 hr, while frq-7 and frq-8 have period lengths of 29 hr and represent the largest effects of any single gene mutants on circadian periodicity. Thus, seven mutants have now been isolated that map to the frq locus, with period lengths ranging from 16.5 to 29 hr, and each mutant alters clock periodicity by an integral multiple of 2.5 hr. In addition, all frq mutants show incomplete dominance in heterokaryons. The large percentage of clock mutants that map to this locus, coupled with their unique properties, suggests that the frq locus plays an important role in clock organization.—The fourth mutant, designated chrono (chr), has a period length of 23.5 hr, shows incomplete dominance and is unlinked to either of the previously identified clock loci, frq or prd (formerly called frq-5). Double mutants between various combinations of clock mutants show additive effects and indicate no significant gene interaction among mutants at these three loci.
INTRA- AND INTERSPECIFIC VARIATION OF THE MITOCHONDRIAL GENOME IN RATTUS NORVEGICUS AND RATTUS RATTUS: RESTRICTION ENZYME ANALYSIS OF VARIANT MITOCHONDRIAL DNA MOLECULES AND THEIR EVOLUTIONARY RELATIONSHIPS
Authors: Brown Gregory G , Simpson Melvin V
Published: April 2021

Restriction endonuclease analysis has revealed extensive mtDNA polymorphism in two species of rats, Rattus rattus and Rattus norvegicus. Sequence divergence values for the eight detected R. norvegicus variants range from 0.2% to 1.8% and for the eight R. rattus variants, from 0.2% to 9.6%. Three of the most closely related R. norvegicus mtDNA's appear to differ by deletions/insertions of about 4 base pairs apiece. Restriction sites for seven enzymes have been mapped for 11 of these variants. The 31 intraspecific and 41 interspecific variant sites appear to be evenly distributed on the mtDNA molecule outside of the rRNA cistrons. The location of sites present in all the DNAs suggests that the rRNA genes and possibly the light strand origin of replication may be more highly evolutionarily conserved than other parts of the molecule. The sequence divergences among the mtDNAs of animals whose geographic origins are separated by major barriers, such as oceans, were significantly greater than those among animals found within large land masses, such as the continental United States. Dendrograms (phenograms), which have been constructed to depict the relationships among the various DNAs, indicate that East Asian members of the R. rattus species are more closely related to American rats of this species than to other Asian R. rattus animals from Sri Lanka. Moreover, it appears that R. norvegicus comprises a group taxonomically distinct from any of the R. rattus subspecies.
DNA POLYMORPHISM DETECTABLE BY RESTRICTION ENDONUCLEASES
Authors: Nei Masatoshi , Tajima Fumio
Published: April 2021

Data on DNA polymorphisms detected by restriction endonucleases are rapidly accumulating. With the aim of analyzing these data, several different measures of nucleon (DNA segment) diversity within and between populations are proposed, and statistical methods for estimating these quantities are developed. These statistical methods are applicable to both nuclear and non-nuclear DNAs. When evolutionary change of nucleons occurs mainly by mutation and genetic drift, all the measures can be expressed in terms of the product of mutation rate per nucleon and effective population size. A method for estimating nucleotide diversity from nucleon diversity is also presented under certain assumptions. It is shown that DNA divergence between two populations can be studied either by the average number of restriction site differences or by the average number of nucleotide differences. In either case, a large number of different restriction enzymes should be used for studying phylogenetic relationships among related organisms, since the effect of stochastic factors on these quantities is very large. The statistical methods developed have been applied to data of Shah and Langley on mitochondrial (mt)DNA from Drosophila melanogaster, simulans and virilis. This application has suggested that the evolutionary change of mtDNA in higher animals occurs mainly by nucleotide substitution rather than by deletion and insertion. The evolutionary distances among the three species have also been estimated.
A SECOND CLASS OF ACETYLCHOLINESTERASE-DEFICIENT MUTANTS OF THE NEMATODE CAENORHABDITIS ELEGANS
Authors: Culotti Joseph G , Von Ehrenstein Gunter , Culotti Marilyn R , Russell Richard L
Published: April 2021

In Johnson et al. (1981), the Caenorhabditis elegans mutant strain PR1000, homozygous for the ace-1 mutation p1000, is shown to be deficient in the class A subset of acetylcholinesterases, which comprises approximately one-half of the total C. elegans acetylcholinesterase activity. Beginning with this strain, we have isolated 487 new behavioral and morphological mutant strains. Two of these, independently derived, lack approximately 98% of the wild-type acetylcholinesterase activity and share the same specific uncoordinated phenotype; both move forward in a slow and uncoordinated manner, and when mechanically stimulated to induce reversal, both hypercontract and become temporarily paralyzed. In addition to the ace-1 mutation, both strains also harbor recessive mutations in the same newly identified gene, ace-2, which maps to chromosome I and is therefore not linked to ace-1. Gene dosage experiments suggest that ace-2 is a structural gene for the remaining class B acetylcholinesterases, which are not affected by ace-1. —The uncoordinated phenotype of the newly isolated, doubly mutant strains depends on both the ace-1 and ace-2 mutations; homozygosity for either mutation alone produces normally coordinated animals. This result implies functional overlap of the acetylcholinesterases controlled by ace-1 and ace-2, perhaps at common synapses. Consistent with this, light microscopic histochemical staining of permeabilized whole mounts indicates some areas of possible spatial overlap of these acetylcholinesterases (nerve ring, longitudinal nerve cords). In addition, there is at least one area where only ace-2-controlled acetylcholinesterase activity appears (pharyngeo-intestinal valve).
SOME NATURAL VIABILITY SYSTEMS FOR A MULTIALLELIC LOCUS: A THEORETICAL STUDY
Authors: Karlin Samuel
Published: April 2021

The maintenance of genetic polymorphism under various natural structured viability regimes vs. general unrestricted fitness assignments are compared. The selection models considered include a generalized dominance fitness system, a generalized viability model based on allelic activity values, viability matrices based on multilocus activity levels, viability matrices defined by partitioned "resource" or "substrate" variables, and circulant-type viability matrices. A number of examples that support these formulations are discussed. Detailed results on the nature of the genotype frequency equilibrium configurations for the specified viability models are presented. An increased likelihood for a globally stable equilibrium is predicted for the more structured viability models.
THE ENTIRE COMPOUND AUTOSOMES OF DROSOPHILA MELANOGASTER
Authors: Novitski E , Grace D , Strommen C
Published: April 2021

Three new unusual compound chromosomes have been synthesized in Drosophila melanogaster. They consist of two homologous autosomes joined together in the new order: right arm, left arm, centromere, left arm, right arm, for each of the two major autosomes, and one in which chromosomes 2 and 3 have been combined in the order: right arm of 2, left arm of 2, centromere, left arm of 3, right arm of 3. The attachments of the autosomal arms were accomplished by obtaining chromosome breaks at or very close to the ends of the left arms of the autosomes such that no essential chromosome material has been removed; the compounds derived from them are therefore referred to as entire compounds. These large chromosomes are recovered in progeny with frequencies lower than expectation partly because of zygote mortality associated with these chromosomes, and partly because of a failure of spermiogenesis.
DISEQUILIBRIUM, SELECTION, AND RECOMBINATION: LIMITS IN TWO-LOCUS, TWO-ALLELE MODELS
Authors: Hastings Alan
Published: April 2021

All possible combinations of equilibria and fitnesses in two-locus, two-allele, deterministic, discrete-generation selection models are enumerated. This knowledge is used to obtain limits (which can be calculated to arbitrary precision) to the relationships among disequilibrium, selection and recombination for fixed values of allele frequencies. In all cases, the inequality|rD| < s/10 holds, where r is recombination and D is disequilibrium, and all selection coefficients lie between 1 - s and 1 + s times that of the double heterozygote. Linear programming techniques are used to calculate the minimum strength of selection needed to explain several observed nonzero values of D reported in the literature. One conclusion is that the failure to observe nonzero values of D is not surprising.
THE EFFECTS OF THREE DIFFERENT MAL LOCI ON THE REGULATION OF MALTASE SYNTHESIS IN YEAST
Authors: Mowshowitz Deborah Bernhardt
Published: April 2021

Inbred haploid strains of Saccharomyces cerevisiae carrying MAL1, MAL2 or MAL6 in a common background have been crossed to each other and to strains carrying no active MAL loci. The kinetics of maltase induction and the induced maltase levels have been examined in the inbred strains and in haploid segregants of the crosses. Differences have been found in the kinetics of induction and induced maltase levels that segregate with the different MAL loci. In the strains tested, the relative rates of maltase induction were MAL2>MAL6>>MAL1; the relative induced maltase levels were MAL2>MAL6~MAL1. These results indicate that MAL1, MAL2 and MAL6 are (or include) regulatory genes that control the accumulation of the enzymes of maltose fermentation.
FURTHER EVIDENCE FOR LACK OF GENE EXPRESSION IN THE TETRAHYMENA MICRONUCLEUS
Authors: Mayo Kristen A , Orias Eduardo
Published: April 2021

Certain galA mutations in the ciliated protozoan Tetrahymena thermophila confer an almost total loss of galactokinase activity in homozygotes. Heterokaryons have been constructed that are homogeneous for the galA1 mutation in the (45n) macronucleus, but which contain a galA  + (2n) micronucleus. Soluble cell extracts prepared from these heterokaryons have been assayed for galactokinase activity, using a radiometric assay for the conversion of galactose to galactose-1-phosphate (gal-1-P). No galactokinase activity attributable to the micronuclear genes is observed in such heterokaryons. These results, obtained with the galA1 marker, provide the first direct, quantitative evidence for the lack of micronuclear (germ line) gene expression in Tetrahymena during vegetative growth, and substantiate the predictions of previous phenotypic observations on heterokaryons and autoradiographic studies of micronuclear RNA synthesis. The generality of this conclusion will be established in the future when other enzymically assayable mutations become available for similar studies.
INDUCED REPAIR OF GENETIC DAMAGE IN NEUROSPORA
Authors: Stadler David , Moyer Richard
Published: April 2021

Repair of genetic damage in Neurospora has been studied using a procedure in which one strain is exposed to a potentially lethal dose of UV before being joined in a heterokaryon with an undamaged strain. We have monitored the ability of the second strain to rescue the first. The extent of rescue is greatly enhanced when the rescuing strain has itself received a small, nonlethal dose of UV, thus demonstrating an inducible repair system.—The experiment was modified by substituting X rays or nitrous acid for UV as either the damaging agent or the inducing agent. In every combination, induced rescue was observed.——Three repair-deficient mutants (uvs-2, uvs-3 and uvs-6) were substituted for wild type (uvs  +) as the rescuing component to find out whether any of them lacked the inducible repair system. Both uvs-2 and uvs-6 demonstrated inducible repair; uvs-3 showed none, but gave a high level of repair without induction, suggesting that it is a regulation (derepressed) mutant of an inducible repair system.
LINKAGE STUDIES INVOLVING TWO CHROMOSOMAL MALE-STERILITY MUTANTS IN HEXAPLOID WHEAT
Authors: Barlow K K , Driscoll C J
Published: April 2021

The factors for Cornerstone and Probus male sterility are allelic on chromosome arm 4Aα. They map independently of the centromere, but show linkage with a rye segment located 1 crossover unit from the centromere on the β arm. The alien segment causes asynapsis and some precocious terminalization of chiasmata when in repulsion with the mutants. The mutants, presumed to be terminal deletions, cause some desynapsis, but not asynapsis.
POST-TRANSLATIONAL MODIFICATION OF XANTHINE DEHYDROGENASE IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER
Authors: Johnson George , Finnerty Victoria , Hartl Daniel
Published: April 2021

Second chromosomes of D. melanogaster were isolated from a single natural population, and 40 were analyzed by gel-sieving electrophoresis for the presence of polymorphic loci on chromosome 2 that act to modify xanthine dehydrogenase and/or aldehyde oxidase, whose structural genes map to chromosome 3. Clear evidence of polymorphism for one or more xanthine dehydrogenase modifier loci was obtained.
CHROMOSOME INVERSION POLYMORPHISMS IN DROSOPHILA MELANOGASTER. I. LATITUDINAL CLINES AND ASSOCIATIONS BETWEEN INVERSIONS IN AUSTRALASIAN POPULATIONS
Authors: Knibb W R , Oakeshott J G , Gibson J B
Published: April 2021

Nineteen Australasian populations of Drosophila melanogaster have been screened for chromosome inversion polymorphisms. All 15 of the inversion types found are paracentric and autosomal, but only four of these, one on each of the major autosome arms, are common and cosmopolitan. North-south clines occur, with the frequencies of all four of the common cosmopolitan inversions increasing toward the equator. These clines in the Southern Hemisphere mirror north-south clines in the Northern Hemisphere, where the frequencies of all four of the common cosmopolitan inversions again increase towards the equator.—While few of the Australasian populations show significant disequilibrium between linked common cosmopolitan inversions, those that do invariably have excesses of coupling gametes, which is consistent with other reports. We also find nonrandom associations between the two major autosomes, with the northern populations in Australasia (those with high inversion frequencies) tending to be deficient in gametes with common cosmopolitan inversions on both major autosomes, while the southern populations in Australasia (low inversion frequencies) tend to have an excess of this class of gametes.—The clines and the nonrandom associations between the two major autosomes are best interpreted in terms of selection operating to maintain the common cosmopolitan inversion polymorphisms in natural populations of D. melanogaster.
γ-GLUTAMYL CYCLOTRANSFERASE: A NEW GENETIC POLYMORPHISM IN THE MOUSE (MUS MUSCULUS) LINKED TO LYT—2
Authors: Tulchin Natalie , Taylor Benjamin A
Published: April 2021

Electrophoretically variant forms of γ-glutamyl cyclotransferase have been identified in red cells of inbred mouse strains. Each inbred strain exhibited a major band of activity and a minor band that migrated more anodally. The polymorphism affects the migration of both the major and minor bands in a similar way. F1 hybrids between strains with fast forms (A/J) and strains with the slow forms (C57BL/6J) exhibited a four-banded pattern consistent with co-dominant inheritance. The patterns observed in backcross and F2 mice were consistent with the segregation of a pair of autosomal co-dominant alleles. Recombinant inbred strains and a congenic strain were used to show that the locus controlling γ-glutamyl cyclotransferase (Ggc) is linked to Lyt-2, a lymphocyte alloantigen locus on chromosome 6, with an estimated map distance of 5.0 ± 2.5 centimorgans.
GENETIC LINKAGE BETWEEN THE AH LOCUS AND A MAJOR GENE THAT INHIBITS SUSCEPTIBILITY TO AUDIOGENIC SEIZURES IN MICE
Authors: Seyfried Thomas N , Glaser Gilbert H
Published: April 2021

Mice of the DBA/2 (D2) strain are highly susceptible to sound-induced seizures at 21 days of age; whereas, mice of the C57BL/6 (B6) strain are resistant to these seizures. Although the difference in susceptibility to audiogenic seizures (ASs) between these two strains is inherited as a multiple-factor trait, an association was observed between susceptibility to ASs and the Ah locus. The Ah locus controls the inducibility of aryl hydrocarbon hydroxylase (AHH) activity by a number of aromatic hydrocarbons. B6 mice carry the Ahb allele and have inducible AHH activity; whereas, D2 mice carry the Ah  d allele and have noninducible activity. Inducibility is inherited as a Mendelian dominant trait in crosses between these strains. Mice carrying the Ahb allele are generally less susceptible to ASs at 21 days of age than are mice carrying the Ahd allele. The combined results from B6 x D2 recombinant inbred strains, congenic strains (where the Ahb allele was placed into the D2 genome and the Ahd allele placed into the B6 genome), the B6D2F1 × D2 backcross generation, and a random survey of various inbred strains, suggest that the association between these two traits is due to genetic linkage, rather than to pleiotrophy or to chance. A major gene that inhibits susceptibility to ASs appears to be closely linked to the Ah locus. This gene has been designated Ias, for inhibition of ASs. A large portion of the genetic variability of AS susceptibility may be due to the segregation of Ias.
MATHEMATICAL STUDY OF THE EVOLUTION OF GYNODIOECY WITH CYTOPLASMIC INHERITANCE UNDER THE EFFECT OF A NUCLEAR RESTORER GENE
Authors: Delannay X , Gouyon P H , Valdeyron G
Published: April 2021

A study is described of the influence of the introduction of a dominant nuclear restorer gene into a cytoplasmic gynodioecious plant population. This study includes the consideration of separate effects on the relative female fertility of nuclear, cytoplasmic and sex (phenotypic) factors. Under these assumptions, the introduction of a dominant nuclear restorer gene into a cytoplasmic gynodioecious population can lead to several different situations: persistence of cytoplasmic gynodioecy, appearance of a nuclear-cytoplasmic gynodioecy, appearance of a nuclear gynodioecy or complete restoration of male fertility. The development of stable nuclear-cytoplasmic gynodioecy in a mathematical model is new and is possible because of the consideration of the separate relative female fertilities. The possibility of a transformation of cytoplasmic gynodioecy into a nuclear one has never been obtained before. It could constitute a route for the appearance of this latter kind of gynodioecy in plant populations. Finally, the possibilities of evolution of gynodioecy from one kind to the other, and towards dioecy, are discussed, as are some theoretical schemes that seem to correspond to observed actual situations.
The incremental cost of improving immunization coverage in India through the Intensified Mission Indradhanush programme
Authors: Chatterjee Susmita , Das Palash , Pinheiro Anita , Haldar Pradeep , Ray Arindam , Brenzel Logan , Resch Stephen
Published: April 2021

Intensified Mission Indradhanush (IMI) was a strategic endeavour launched by the Government of India aiming to achieve 90% full immunization coverage in the country by 2018. The basic strategy of this special drive involved identifying missed children and vaccinating them in temporary outreach sites for 1 week over consecutive 4-month period starting from October 2017. This study estimated the incremental economic and financial cost of conducting IMI in India from a government provider perspective. Five states—Assam, Bihar, Maharashtra, Rajasthan and Uttar Pradesh were purposefully selected because of high concentration of IMI activities. The stratified random sample of 40 districts, 90 sub-districts and 289 sub-centres were included in this study. Cost data were retrospectively collected at all levels from administrative records, financial records and staff interviews involved in IMI. The weighted incremental economic cost per dose (including vaccine costs) was lowest in Uttar Pradesh (US$3.45) and highest in Maharashtra (U$12.23). Incremental economic cost per IMI dose was found to be higher than a recent routine immunization costing study by Chatterjee and colleagues in 2018, suggesting that it requires additional resources to immunize children through an intensified push in hard-to-reach areas. Incremental financial cost of the IMI programme estimated in this study will be helpful for the government for any future planning of such special initiative. The reasons for variation of unit costs of IMI across the study districts are not known, but lower baseline coverage, high population density, migration, geography and terrain and vaccinating small numbers of children per session could account for the range of findings. Further analysis is required to understand the determinants of cost variations of the IMI programme, which may aid in better planning and more efficient use of resources for future intensified efforts.
Cost-Reducing Traits for Agonistic Head Collisions: A Case for Neurophysiology
Authors: Tobiansky Daniel J , Long Kira M , Hamden Jordan E , Brawn Jeffrey D , Fuxjager Matthew J
Published: April 2021

Synopsis

Many animal species have evolved extreme behaviors requiring them to engage in repeated high-impact collisions. These behaviors include mating displays like headbutting in sheep and drumming in woodpeckers. To our knowledge, these taxa do not experience any notable acute head trauma, even though the deceleration forces would cause traumatic brain injury in most animals. Previous research has focused on skeletomuscular morphology, biomechanics, and material properties in an attempt to explain how animals moderate these high-impact forces. However, many of these behaviors are understudied, and most morphological or computational studies make assumptions about the behavior without accounting for the physiology of an organism. Studying neurophysiological and immune adaptations that covary with these behaviors can highlight unique or synergistic solutions to seemingly deleterious behavioral displays. Here, we argue that selection for repeated, high-impact head collisions may rely on a suite of coadaptations in intracranial physiology as a cost-reducing mechanism. We propose that there are three physiological systems that could mitigate the effects of repeated head trauma: (1) the innate neuroimmune response; (2) the glymphatic system, and (3) the choroid plexus. These systems are interconnected yet can evolve in an independent manner. We then briefly describe the function of these systems, their role in head trauma, and research that has examined how these systems may evolve to help reduce the cost of repeated, forceful head impacts. Ultimately, we note that little is known about cost-reducing intracranial mechanisms making it a novel field of comparative study that is ripe for exploration.
Balancing on a Limb: Effects of Gravidity on Locomotion in Arboreal, Limbed Vertebrates
Authors: Smith Shaylee K , Hilliard Young Vanessa K
Published: April 2021

Reproduction is linked to a plethora of costs in gravid females, not least of which is a reduction in locomotor performance. Locomotor constraints due to gravidity are apparent across aquatic, terrestrial, and arboreal habitats. Decrements to speed and maneuverability are the most often cited performance consequences of gravidity, regardless of habitat. Arboreal habitats present additional challenges, as they often are composed of unstable and varying substrates that affect locomotor performance. Many arboreal taxa exhibit morphological adaptations, such as grasping extremities and tails, that function to aid in stability during locomotion. Tail length has been found to correlate with lifestyle: arboreal mammals tend to have relatively longer tails compared with terrestrial counterparts. Balancing on a limb is hard on its own, but when combined with increased mass and shifts in center of mass due to pregnancy, it becomes even more challenging. However, few studies have explored the constraints that govern the intersection of arboreal locomotion, reproductive cost, and morphology. In this review, we identify fruitful areas for expansion of research and knowledge (i.e., the role of the tail) when it comes to arboreal balance during gestation.
Early-Life Corticosterone Body Condition Influence Social Status and Survival in a Food-Caching Passerine
Authors: Freeman Nikole E , Norris D Ryan , Sutton Alex O , Strickland Dan , Kyser T Kurt , Newman Amy E M
Published: April 2021

Synopsis

Individuals undergo profound changes throughout their early life as they grow and transition between life-history stages. As a result, the conditions that individuals experience during development can have both immediate and lasting effects on their physiology, behavior, and, ultimately, fitness. In a population of Canada jays in Algonquin Provincial Park, Ontario, Canada, we characterized the diet composition and physiological profile of young jays at three key time points during development (nestling, pre-fledge, and pre-dispersal) by quantifying stable-carbon (δ13C) and -nitrogen (δ15N) isotopes and corticosterone concentrations in feathers. We then investigated the downstream effects of early-life diet composition, feather corticosterone, and environmental conditions on a juvenile’s social status, body condition, and probability of being observed in the fall following hatch. Across the three time points, the diet of Canada jay young was composed primarily of vertebrate tissue and human food with the proportion of these food items increasing as the jays neared dispersal. Feather corticosterone concentrations also shifted across the three time points, decreasing from nestling to pre-dispersal. Dominant juveniles had elevated corticosterone concentrations in their feathers grown pre-dispersal compared with subordinates. High body condition as nestlings was associated with high body condition as juveniles and an increased probability of being observed in the fall. Together, our results demonstrate that nestling physiology and body condition influence the social status and body condition once individuals are independent, with potential long-term consequences on survival and fitness.
Dialogue and distrust: John Hart Ely and the Canadian Charter
Authors: Sigalet Geoffrey Thomas
Published: April 2021

John Hart Ely’s process theory of judicial review has had an influence on constitutions across the globe. This article explores and evaluates Ely’s influence on the drafting and development of the 1982 Canadian Charter of Rights and Freedoms. The article first outlines the rudimentary elements of Ely’s theory of judicial review, then how Ely’s explicit influence on the development of the Charter has mostly been limited to the context of Section 15 equality rights. But Ely’s influence has been more extensive in the way scholars have sought to understand the Charter. The third section of this article shows how Ely has had an impact on Patrick Monahan’s theory of judicial review under the Charter, and in Rosalind Dixon’s process theory of dialogue. The article concludes by arguing that although Ely’s concerns remain relevant in the Canadian context, there are two reasons to be skeptical of using Ely’s theory to understand Charter rights: the first reason is that the Charter features substantive rights that do not seem to be reducible to protections for participation in the political process; the second reason is that process-based dialogue theory appears to be insufficiently distrusting of courts.
Intranasal Oxytocin for Negative Symptoms of Schizophrenia: Systematic Review, Meta-Analysis, and Dose-Response Meta-Analysis of Randomized Controlled Trials
Authors: Sabe Michel , Zhao Nan , Crippa Alessio , Strauss Gregory P , Kaiser Stefan
Published: April 2021

Background

Negative symptoms are a core aspect of psychopathology in schizophrenia. Currently available pharmacological agents have proven minimally efficacious for remediating negative symptoms. A promising treatment avenue is the intranasal administration of the neuropeptide oxytocin. However, there have been inconsistencies in effects of oxytocin on negative symptoms throughout the literature, and factors leading to inconsistent effects are unclear.

Methods

We conducted a systematic review and meta-analysis of randomized clinical trials to compare the effectiveness of oxytocin with placebo for the treatment of negative symptoms and determine moderators of treatment effect. Random effects meta-analyses and dose-response meta-analysis were performed on mean changes in negative symptoms.

Results

In an initial analysis of all 9 identified randomized clinical trials, intranasal oxytocin showed no significant effect on negative symptoms. For higher doses (>40–80 IU), a beneficial effect on negative symptoms was found with a moderate effect size, but this effect disappeared after exclusion of 1 outlier study. The dose-response meta-analysis predicted that higher doses of oxytocin may be more efficacious for negative symptoms. For positive symptoms, no beneficial effect of oxytocin was found in the main meta-analysis, but the dose-response meta-analysis suggested a potential advantage of higher doses.

Conclusions

The present results show no consistent beneficial effect of intranasal oxytocin for the treatment of negative and positive symptoms. The dose-response meta-analysis does not allow drawing any firm conclusions but suggests that high doses of intranasal oxytocin may be more efficacious. If future studies are conducted, an effort to reach adequate CNS concentrations for a sufficient duration is required.
Development and feasibility testing of an evidence-based training programme for pharmacist independent prescribers responsible for the medicines-related activities within care homes
Authors: Wright David J , Blyth Annie , Maskrey Vivienne , Norris Nigel , Bond Christine M , Hughes Carmel M , Alldred David P , Holland Richard C ,   CHIPPS Team
Published: April 2021

Introduction

The UK pharmacists with independent prescribing rights (pharmacist independent prescribers [PIPs]) are authorised to prescribe within their areas of competence. To enable PIPs to provide pharmaceutical care to residents in care homes and assume responsibility for medicines management, a process for development and assessment of competence is required. The aim of this research was to develop a training and accreditation process (training programme) to enable PIPs to operate safely and effectively within care homes.

Methods

Located in England, Scotland and Northern Ireland across four sites and based on a systematic review, it consisted of four phases: (1) initial stakeholder engagement, (2) uni-professional focus groups and interviews, (3) expert panel consensus and (4) feasibility testing. Four PIPs were trained each to provide pharmaceutical care to 10 care home residents. An expert panel synthesised the evidence at each stage to develop each iteration of the training programme. Content analysis was used throughout.

Results

Differences in baseline knowledge of PIPs required inclusion of a Personal Development Framework and the provision of a mentor. Face-to-face training focussed on managing medicines for a complex older person, minimising prescribing costs and supporting people without capacity. Provision of time to understand local context and develop relationships with care homes and general practitioners was identified as a central requirement. PIPs were assessed for competency via viva. Feasibility testing demonstrated that the derived training programme was acceptable, practical and effective.

Discussion

The model seemed to work, but due to small numbers, larger-scale testing of the training programme is now required.
Flux-stability for conservation laws with discontinuous flux and convergence rates of the front tracking method
Authors: Ruf Adrian M
Published: April 2021

We prove that adapted entropy solutions of scalar conservation laws with discontinuous flux are stable with respect to changes in the flux under the assumption that the flux is strictly monotone in $u$ and the spatial dependency is piecewise constant with finitely many discontinuities. We use this stability result to prove a convergence rate for the front tracking method—a numerical method that is widely used in the field of conservation laws with discontinuous flux. To the best of our knowledge, both of these results are the first of their kind in the literature on conservation laws with discontinuous flux. We also present numerical experiments verifying the convergence rate results and comparing numerical solutions computed with the front tracking method to finite volume approximations.
Institutional and behaviour-change interventions to support COVID-19 public health measures: a review by the Lancet Commission Task Force on public health measures to suppress the pandemic
Authors: Lee Jong-Koo , Bullen Chris , Ben Amor Yanis , Bush Simon R , Colombo Francesca , Gaviria Alejandro , Karim Salim S Abdool , Kim Booyuel , Lavis John N , Lazarus Jeffrey V , Lo Yi-Chun , Michie Susan F , Norheim Ole F , Oh Juhwan , Reddy Kolli Srinath , Rostila Mikael , Sáenz Rocío , Smith Liam D G , Thwaites John W , Were Miriam K , Xue Lan ,   (The Lancet COVID-19 Commission Task Force for Public Health Measures to Suppress the Pandemic)
Published: April 2021

The Lancet COVID-19 Commission Task Force for Public Health Measures to Suppress the Pandemic was launched to identify critical points for consideration by governments on public health interventions to control coronavirus disease 2019 (COVID-19). Drawing on our review of published studies of data analytics and modelling, evidence synthesis and contextualisation, and behavioural science evidence and theory on public health interventions from a range of sources, we outline evidence for a range of institutional measures and behaviour-change measures. We cite examples of measures adopted by a range of countries, but especially jurisdictions that have, thus far, achieved low numbers of COVID-19 deaths and limited community transmission of severe acute respiratory syndrome coronavirus 2. Finally, we highlight gaps in knowledge where research should be undertaken. As countries consider long-term measures, there is an opportunity to learn, improve the response and prepare for future pandemics.
Polarisation and Poverty Reduction in Africa: The Devil Is in the Choice of Equivalence Relation
Authors: Partridge Fraser C
Published: April 2021

The focus of this paper is the low observed mean consumption elasticity of poverty in Africa, and the suggestion that polarisation of national distributions, specifically the non-parametric ‘relative distribution’ method, is essential to understand the low regional elasticity. The version of the methodology adopted results in a measure of absolute polarisation. We show that the results obtained for 24 countries in the region are entirely a product of this choice, and while preference for translation invariance is a normative matter, claims regarding changes in distributions are not. There is no evidence of distributional changes unaccounted for by standard measures of inequality and mean consumption. These variables also explain the evolution of poverty levels in the 24-country sample. Given that changes in mean consumption and inequality account for both the changes in the chosen measure of polarisation and the evolution of poverty, there is no distinct role for the chosen measure of polarisation in accounting for the evolution of poverty in the region.
Massive Burns: Retrospective Analysis of Changes in Outcomes Indicators Across 18 Years
Authors: Meuli Joachim N , Pantet Olivier , Berger Mette M , Waselle Laurent , Raffoul Wassim
Published: April 2021

The treatment and management of massive burns, defined as burns affecting at least 50% of total body surface area (TBSA), have considerably changed since the 1990s. This study aimed at analyzing if the length of intensive care unit (ICU) stay, the success of skin grafting operations, and the mortality changed in the past 18 years. Between 2000 and 2018, 77 patients were admitted for massive burns to the ICU of a university hospital. Transfers and early care withdrawal precluded inclusion for 38 patients, leaving 39 for analysis. Study variables were year of admission, demographics, burn characteristics, critical care treatment (fluid resuscitation, ventilation, and nutrition), and surgical therapy. Association between outcomes and year of admission was assessed through correlation and logistic regression analysis. Potential confounders were assessed through stepwise linear regression. Patients’ characteristics were stable over time with a median age of 36 (25.0–48.0) years, burns 65% (55.0–83.0) TBSA, and deep burns 55% (50.0–68.0) TBSA. Length of ICU stay remained stable at 0.97 (0.6–1.5) days/%TBSA. Mortality was stable as well. Energy and carbohydrate delivery decreased in parallel with the number of infectious episodes per patient. The number of operations was stable, but the take rate of skin grafts increased significantly. The multivariate analysis retained year of admission, weight, the total number of infections, daily lipid intakes, and fluid resuscitation as independent predicting variables.
Doing Relationship Work: A Theory of Change in Consumer–Brand Relationships
Authors: Alvarez Claudio , Brick Danielle J , Fournier Susan
Published: April 2021

This article proposes a novel theory, based on relational paradoxes, to explain how consumers enable or disable their relationships with brands over time. Analysis of data from in-depth, longitudinal interviews with 26 consumers reveals four relational tensions and seven actions that consumers take in response to these tensions, thus affecting the course and character of their brand relationships. Four consumer actions enable the consumer–brand relationship by creating patterns of relationship change based on equilibrium or transformation; three actions disable the relationship via patterns of vicious cycles or conflict. Overall, consumers do relationship work as they act to navigate tensions, thereby creating, maintaining, changing, and terminating their brand relationships. This research has implications for current theory on brand relationship templates, dysfunctional brand relationships, and customer relationship management.