bluuebunny/crossref_metadata_2025 huggingface dataset:
MALE-SPECIFIC LETHAL MUTATIONS OF DROSOPHILA MELANOGASTER
Authors: Belote John M , Lucchesi John C
Published: April 2021

A total of 7,416 ethyl methanesulfonate (EMS)-treated second chromosomes and 6,212 EMS-treated third chromosomes were screened for sex-specific lethals. Four new recessive male-specific lethal mutations were recovered. When in homozygous condition, each of these mutations kills males during the late larval or early pupal stages, but has no detectable effect in females. One mutant, mlets, is a temperature sensitive allele of maleless, mle (Fukunaga, Tanaka and Oishi 1975), while the other three mutants identify two new loci: male-specific lethal-1 (msl-1) (two alleles) at map position 2-53.3 and male-specific lethal-2 (msl-2) at 2-9.0.——The male-specific lethality associated with these mutants is not related to the sex per se of the mutant flies, since sex-transforming genes fail to interact with these mutations. Moreover, the presence or absence of a Y chromosome in males or females has no influence on the male-specific lethal action of these mutations. Finally, no single region of the X chromosome, when present as a duplication, is sufficient to rescue males from the lethal effects of msl-1 or msl-2. These results suggest that the number of complete X chromosomes determines whether a fly homozygous for a male-specific lethal mutation lives or dies.
ORGANIZATION OF THE CHORION GENES OF BOMBYX MORI, A MULTIGENE FAMILY. III. DETAILED MARKER COMPOSITION OF THREE GENE CLUSTERS
Authors: Goldsmith Marian R , Clermont-Rattner Eileen
Published: April 2021

The chorion patterns produced by progeny from crosses that were used to define the linked gene clusters, Ch 1, Ch 2 and Ch 3 (strain C108 vs. strain Ascoli), were examined by two-dimensional gel electrophoresis (isoelectric focusing vs. SDS/urea). Approximately 60 proteins were assigned to four previously defined chorion classes, A, B, C and Hc, believed to represent the products of related genes, on the basis of size and relative cysteine content. All strain-specific markers showed co-dominance in the F1, indicating the likelihood that they are not products of post-translational modification. Twentyseven Ascoli markers co-segregated in testcross progeny, and none of the resolved proteins showed independent assortment, confirming their linkage to chromosome 2. Two-dimensional screening of recombinants demonstrated that all three clusters contain Class A and B markers; Hc markers have been found only in Ch 1 and Ch 2; whereas, mapped C markers were confined to Ch 3. This indicates that chorion clusters are heterogeneous with respect to the markers they contain.
QUANTITATIVE MEASUREMENT OF THE ABILITY OF DIFFERENT MUTAGENS TO INDUCE AN INHERITED CHANGE IN PHENOTYPE TO ALLOW MALTOSE UTILIZATION IN SUSPENSION CULTURES OF THE SOYBEAN, GLYCINE MAX (L.) MERR
Authors: Weber Gerd , Lark K G
Published: April 2021

Using a newly developed plating system, we have measured cell survival and the frequencies of variation in an inherited trait after treatment of soybean cell suspensions with different mutagens: ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), N-Methyl-N′-nitro-N-nitroso-guanidine (MNNG), hycanthone (1-{[2-(diethylamino) ethyl] amino}-4-(hydroxymethyl)-9H-thioxanthen-9-one and ultraviolet light (UV).—The heritable variation selected for displays a phenotype of rapid growth on maltose as carbon source. The marker is stable in the absence of maltose, and prolonged growth of variant cells on sucrose has not shown reversions to slow growth. Doubling time in suspension cultures is decreased from 100 hr to ca. 30 hr by the mutation. Both wild-type and variant cells grow on sucrose with a 24-hr doubling time. Thus, lethality after mutagen treatment can be estimated rapidly by growth on sucrose, whereas variants are scored on maltose medium. The spontaneous frequency of variants was 1.2 × 10-7; induced frequencies ranged from a low of 3.6 × 10-5 for EMS to a high of 10-3 for hycanthone. The high frequency of variants induced by hycanthone, a frame-shift mutagen, and the observation that UV induces variants in haploid cells with much higher frequency than in diploid cells suggests a recessive mutation.
EVOLUTION OF INTERACTIONS IN FAMILY-STRUCTURED POPULATIONS: MIXED MATING MODELS
Authors: Michod Richard E
Published: April 2021

The effect of inbreeding on sociality is studied theoretically for the evolution of interactions between siblings in certain mixed mating systems that give rise to inbreeding: sib with random mating and selfing with random mating. Two approaches are taken. First, specific models of altruism are studied for the various mating systems. In the case of the additive model, inbreeding facilitates the evolution of altruistic genes. Likewise, for the multiplicative model this is usually the case, as long as the costs of altruism are not too great. Second, the case of total altruism, in which the gene has zero individual fitness but increases the fitness of associates, is studied for a general fitness formulation. In this case, inbreeding often retards the ability of such genes to increase when rare, and the equilibrium frequency of those recessive genes that can increase is totally independent of the mating system and, consequently, of the amount of inbreeding. It appears from the results presented that inbreeding facilitates most forms of altruism, but retards extreme altruism. These results stem from the fact that inbreeding increases the within-family relatedness by increasing the between-family variance in allele frequency. In most cases this facilitates altruism. However, in the case of total altruism, only heterozygotes can pass on the altruistic allele, and inbreeding tends to decrease this heterozygote class. In either case, the important effect of inbreeding lies in altering the genotypic distribution of the interactions.
MEIOSIS IN NEUROSPORA CRASSA. I. THE ISOLATION OF RECESSIVE MUTANTS DEFECTIVE IN THE PRODUCTION OF VIABLE ASCOSPORES
Authors: DeLange A M , Griffiths A J F
Published: April 2021

A scheme has been devised for efficient isolation of recessive meiotic mutants of Neurospora crassa. These mutants were detected by their reduced fertility or by the abortion of ascospores. Their isolation involved the selection and screening of strains arising from ascospores disomic (n + 1) for linkage group I (LG I), which bears the mating-type locus. These strains are self-fertile heterokaryons that contain two types of haploid nuclei of opposite mating type (A + a). Selfings of these strains are homozygous for genes on all linkage groups except LGI and therefore allow the expression of recessive mutants with an altered sexual cycle. Using this selection procedure, three classes of mutants were detected. In one class, mutants had an early block in perithecial development (class I), and in another mutants had altered perithecia, but apparently unaltered fertility (class III). No recessive mutants were observed and all mutants tested (eight of class I and two of class III) were expressed only when used as the maternal parent. A third mutant class displayed normal production of perithecia, but defective formation of asci (class IIA), or black ascospores (class IIB). Four of 13 class IIA mutants were analyzed, and two of them [asc(DL131) and asc(DL400)] were definitely recessive. Analysis of 10 of 13 class IIB mutants disclosed six recessive, mutually complementing mutants: asc(DL95), asc(DL243), asc(DL711), asc(DL879), asc(DL917m) and asc(DL961). Mutants asc(DL95), asc(DL243) and the previously studied mei-1 mutant (Smith 1975) complemented one another in crosses, but did not recombine. These may be alleles of the same gene, or they may comprise a gene cluster.
REGULATORY GENES CONTROLLING MITOSIS IN THE FISSION YEAST SCHIZOSACCHAROMYCES POMBE
Authors: Nurse Paul , Thuriaux Pierre
Published: April 2021

Fifty-two wee mutants that undergo mitosis and cell division at a reduced size compared with wild type have been genetically analyzed. The mutants define two genes, wee1 and cdc2, which control the timing of mitosis. Fifty-one of the mutants map at the wee1 locus, which is unlinked to any known cdc gene. One of the wee1 alleles has been shown to be nonsense suppressible. The 52nd wee mutant maps within cdc2. Previously, only temperature-sensitive mutants that become blocked at mitosis have been found at the cdc2 locus. The simplest interpretation of these observations is that wee1  + codes for a negative element or inhibitor, and cdc2  + codes for a positive element or activator in the mitotic control. The gene dosage of wee1  + plays some role in determining the timing of mitosis, but the gene dosage of cdc2  + has little effect. However, some aspect of the cdc2 gene product activity is important for determining when mitosis takes place. The possible roles of wee1 and cdc2 in the mitotic control are discussed, with particular reference to the part they may play in the monitoring of cell size and cell growth rate, both of which influence the timing of mitosis.
GENETIC STRUCTURE OF PILEOLARIA PSEUDOMILITARIS (POLYCHAETA: SPIRORBIDAE)
Authors: Beckwitt Richard
Published: April 2021

The genetic structure of Pileolaria pseudomilitaris was studied by means of gene-diversity analysis of allozyme frequencies. At an esterase locus, most of the gene diversity was due to subdivision of the population into colonies and subpopulations separated by less than 100 meters. Gene frequencies at a phosphoglucose isomerase locus were similar over many kilometers, but differed between two habitat types. Differences between colonies are attributed to drift and founder effect; similarities over greater distances are attributed to similar selection pressures. A mathematical appendix details the method of gene diversity analysis for a multi-leveled, hierarchically subdivided population.
GENETIC FACTORS AFFECTING RECOVERY OF NONPOINT MUTATIONS IN THE REGION OF A GENE CODING FOR ORNITHINE TRANSCARBAMYLASE: INVOLVEMENT OF BOTH THE F FACTOR IN ITS CHROMOSOMAL STATE AND THE recA GENE
Authors: Jessop Adrienne P , Glansdorff N
Published: April 2021

Mutants of E. coli K12 that overproduce ornithine transcarbamylase can be identified in Car- strains because they permit utilization of citrulline as a carbamyl phosphate source, due to reversal of the normal OTCase reaction; they are called Cut mutants (citrulline utilizers). Hfr strains that carry the F factor adjacent to argF (one of two duplicate genes that code for ornithine transcarbamylase in E. coli K12) yield more Cut mutants than do F+ or F- strains, or Hfr strains in which the F factor is not adjacent to argF. When Hfr strains in which the F factor is integrated adjacent to argF are made recA, they yield few Cut mutants. Many of the Cut mutants recovered from one of the Hfr strains used in the investigation (Hfr P4X) are unstable; the properties of these unstable mutations suggest that they carry aberrations in the region of the argF gene. Thus, the increased yields of Cut mutants probably result from aberrations that occur when the F factor is integrated adjacent to argF. The nature of these aberrations is not yet known. The unstable Cut mutants are to a large extent stabilized by recA; such stabilization is one of the properties of duplications. Other data indicate that the aberrations may be more complex than simple gene duplications; in particular properties of segregants and some recombinants derived from unstable Cut mutants are most easily interpreted by assuming that segregation from, and possibly formation of, the unstable mutants occurs in several stages.
PROTEIN DEGRADATION, MEIOSIS AND SPORULATION IN PROTEINASE-DEFICIENT MUTANTS OF SACCHAROMYCES CEREVISIAE
Authors: Zubenko George S , Jones Elizabeth W
Published: April 2021

During the process of sporulation, a/α diploids degrade about 50% of their vegetative proteins. This degradation is not sporulation specific, for asporogenous diploids of a/a mating type degrade their vegetative proteins in a fashion similar to that of their a/α counterparts. Diploids lacking carboxypeptidase Y activity, prc1/prc1, show about 80% of wild-type levels of protein degradation, but are unimpaired in the production of normal asci. Diploids lacking proteinase B activity, prb1/prb1, show about 50% of wild-type levels of protein degradation. The effect on degradation of the proteinase B deficiency is epistatic to the degradation deficit attributable to the carboxypeptidase Y deficiency. The prb1 homozygotes undergo meiosis and produce spores, but the asci and, possibly, the spores are abnormal. Diploids homozygous for the pleiotropic pep4-3 mutation show only 30% of the wild-type levels of degradation when exposed to a sporulation regimen, and do not undergo meiosis or sporulation. Neither proteinase B nor carboxypeptidase Y is necessary for germination of spores. ——Approximately half of the colonies arising from a/a or α/α diploids exposed to the sporulation regiment that express an initially heterozygous drug-resistance marker (can1) appear to arise from mating-type switches followed by meiosis and sporulation.
A SECOND INFORMATIONAL SUPPRESSOR, SUP-7 X, IN CAENORHABDITIS ELEGANS
Authors: Waterston Robert H
Published: April 2021

More than 30 independent suppressor mutations have been obtained in the nematode C. elegans through reversion analysis of two unc-13 mutants. Many of the new isolates map to the region of the previously identified informational suppressor, sup-5 III (Waterston and Brenner 1978). Several of the other suppressor mutations map to the left half of the X-linkage group and define a second suppressor gene, sup-7 X. In tests against 40 mutations in six genes, the sup-7(st5) allele was found to suppress to a greater extent the same alleles acted on by sup-5(e1464). Like sup-5(e1464), sup-7(st5) acts on null alleles of the myosin heavy-chain gene unc-54 I (MacLeod et al. 1977; MacLeod, Waterston and Brenner 1977) and the putative paramyosin gene unc-15 I (Waterston et al. 1977). Chemical analysis of unc-15(e1214); sup-7(st5) animals show that paramyosin is restored to more than 30% of the wild-type level. —As was observed for sup-5(e1464), suppression by sup-7(st5) is dose dependent and is greater in animals grown at 15° than at 25°. However, associated with this increased suppression is a decreased viability of sup-7(st5) homozygotes. Reversion of the lethality has resulted in the isolation of deficiency mutations that complement st5 lethality, but lack suppressor function. These properties of sup-7(st5) suggest that it, like sup-5(e1464), is an informational suppressor of null alleles, and its reversion via deficiencies further narrows the possible explanations of its action.
ANALYSIS OF PLEIOTROPISM AT THE DOMINANT WHITE-SPOTTING (W) LOCUS OF THE HOUSE MOUSE: A DESCRIPTION OF TEN NEW W ALLELES
Authors: Geissler Edwin N , McFarland Eleanor C , Russell Elizabeth S
Published: April 2021

Characterization of the pleiotropic effects of ten new putative W locus mutations, nine co-isogenic and one highly congenic with the C57BL/6J strain, reveals a wide variety of influences upon pigmentation, blood formation and gametogenesis. None of the putative alleles, each of which is closely linked to Ph, a gene 0.1 cM from W, gave evidence of complementation with W39, a new allele previously shown to be allelic to Wv. All W*/W39 genotypes resulted in black-eyed-white anemics with reduced gametogenic activity.1 Homozygotes for seven of these mutations are lethal during perinatal life; anemic embryos have been identified in litters produced by intercross matings involving each of these alleles. —Phenotypes of mice of several mutant genotypes provide exceptions to the frequent observation that a double dose of dominant W alleles (e.g., W/Wv or W/W) results in defects of corresponding severity in each of the three affected tissues. One viable homozygote has little or no defect in blood formation, and another appears to have normal fertility. The phenotypes of these homozygotes support the conclusion that the three tissue defects are not dependent on each other for their appearance and probably do not result from a single physiological disturbance during the development of the embryo. —Although homozygosity for members of this series results in a wide range of phenotypes, the absence of complementation of any allele with W39, the close proximity of each mutant to Ph, and the fact that all alleles produce detectable (though sometimes marginal) defects in the same tissues affected by W and Wv, support the hypothesis that each new mutant gene is a W allele.
DENSITY- AND FREQUENCY-DEPENDENT SELECTION AT THE Mdh-2 LOCUS IN DROSOPHILA PSEUDOOBSCURA
Authors: ToŠić Mirjana , Ayala Francisco J
Published: April 2021

We have studied differenccs in the number of Drosophila pseudoobscura produced in a culture when the flies differ with respect to two alleles (F and S) at the Mdh-2 locus, which codes for a malate dehydrogenase enzyme. The studies were done at low and at high density in two- and three-genotype combinations (S/S, F/F and S/F), with one-genotype cultures as controls.—— Density affects the fitness of the Mdh-2 genotypes. Different genotypes are differently affected, and the genotype of the competitors also makes a difference on the fitness of a given genotype. When three genotypes are present in a culture, particularly at high density, intergenotypic competition is less intense than intragenotypic competition at several frequency combinations. That is, there is "overcompensation": the three genotypes together exploit the environmental resources better than one genotype alone.———The fitness of the genotypes is frequency dependent in both two-genotype and three-genotype combinations. An inverse relationship between frequency and fitness is observed at high density. This may lead to a stable polymorphism, because the fitness of a genotype increases as its frequency decreases.——Forty independent strains, sampled from a natural population, were used in the experiments. This ensures that more than 95% of the variation present in the genome in the natural population is also present is the experimental cultures. It also ensures that the genetic background of the Mdh-2 alleles is randomized in the same way as it is in nature. However, the possibility remains that Mdh-2 alleles in nature are nonrandomly associated with alleles at closely linked loci. If linkage disequilibrium is present in the experiments because it exists in nature, then the observed effects (such as frequency-dependent selection) would affect the Mdh-2 locus in nature as well.
THE CHROMOSOMAL BASIS OF SEXUAL ISOLATION IN TWO SIBLING SPECIES OF DROSOPHILA: D. ARIZONENSIS AND D. MOJAVENSIS
Authors: Zouros E
Published: April 2021

The chromosomal determination of interspecific differences in mating behavior was studied in the interfertile pair, Drosophila arizonensis and Drosophila mojavensis, by means of chromosomal substitutions. Interspecific crossing over was avoided by crossing hybrid males to parental females, and identification of the origin of each chromosome in backcrossed hybrids was possible by means of allozyme markers. It was found that male mating behavior is controlled by factors located in the PGM-marked chromosome (which, in other Drosophila species, is part of the X chromosome) and in the Y chromosome. The other chromosomes influence male sexual behavior through their interactions with each other and with the PGM-marked chromosome, but their overall effect is minor. Female mating behavior is controlled by factors located in the ODH-marked and AMY-marked chromosomes, with the other chromosomes exercising a small additive effect. Hence, the two sex-specific behaviors are under different genetic control. Cytoplasmic origin has no effect on the mating behavior of either sex. There appears to be no correlation between a chromosome's structural diversity (i.e., amounts of inversion polymorphism within a species or numbers of fixed inversions across species) and its contribution to sexual isolation. These findings are in general agreement with those from similar Drosophila studies and may not be specific to the species studied here.
RELATIONSHIP BETWEEN THE NUMBER OF HOMOEOLOGUES, CHIASMA FREQUENCY AND THE FREQUENCY OF TELOSOME PAIRING IN WHEAT
Authors: McGuire Patrick E , DvořÁk Jan
Published: April 2021

Pairing frequencies of a single telosome in groups of two, three, four, five and six equally related homoeologues were calculated for a range of values of c (the ratio of actual chiasma frequency to the total possible number of chiasmata, as described by Driscoll, Bielig and Darvey 1979). At low c values, the frequency of telosome pairing is little affected by the number of homoeologues. At high c values, the frequency is little affected by the number of homoeolgues if the number is even; if the number is odd, the frequency is dependent on the number of homoeologues and increases with increasing numbers of homoeologues. At intermediate c values, the pairing frequency is dependent on the number of homoeologues for both even and odd numbers of homoeologues.
DENSITY-DEPENDENT FERTILITY SELECTION IN EXPERIMENTAL POPULATIONS OF DROSOPHILA MELANOGASTER
Authors: Clark Andrew G , Feldman Marcus W
Published: April 2021

The effects of larval density on components of fertility fitness were investigated with two mutant lines of Drosophila melanogaster. The differences in adult body weight, wing length, larval survivorship and development time verified that flies reared at high density were resource limited. Experimental results indicate that: (1) relative fecundities of both sexes show density-dependent effects, (2) there is a strong density effect on male and female mating success, and (3) in general, there is a reduction in fecundity differences between genotypes at high density. These results imply that it may be important to consider fertility in models of density-dependent natural selection.
DELETION ANALYSIS OF THE TUMOROUS-HEAD (tuh—3) GENE IN DROSOPHILA MELANOGASTER
Authors: Kuhn David T , Woods Daniel F , Andrew Deborah J
Published: April 2021

In the presence of the naturally occurring maternal-effect alleles tuh-1h or tuh-1g, the tuh-3 mutant gene can cause the tumorous-head trait or the sac-testis trait. The tuh-3 gene functions as a semidominant in the presence of the tuh-1h maternal effect. Eye-antennal structures are replaced by posterior abdominal tergites and genital structures. If tuh-1h is replaced by its naturally occurring allele tuh-1g, tuh-3 functions as a recessive hypomorph and the defect switches from anterior to posterior structures, with a male genital-disc defect appearing with variable penetrance. Function and regulation of tuh-3  + may better be understood in light of the cytological localization of tuh-3 either adjacent to or as part of the bithorax complex. The tuh-3  + gene product appears to be essential for normal development, at least in the posterior end of the embryo.
THE GENETIC SYSTEM CONTROLLING RECOMBINATION IN THE SILKWORM
Authors: Ebinuma Hiroyasu , Yoshitake Narumi
Published: April 2021

The nature of recombination modifiers was investigated in Bombyx mori lines selected for high (H) and low (L) recombination rates between the pS and Y loci in chromosome 2. Since the mean recombination rates for the H × L and L × H F1 crosses were approximately intermediate between those of high and low lines, the cytoplasmic maternal effect and difference in the activity of recombination modifiers between marked and unmarked second chromosomes were not detected. The H × (L × H), H × (H × L), L × (L × H) and L × (H × L) backcrosses indicated the presence of additive and dominance effects of marked and unmarked second chromosomes and the remaining chromosomes.——Recombination rates between the pS and Y loci in chromosome 2 and half-nonrecombination rates between the pe and re loci in chromosome 5 of high and low lines indicated that these recombination modifiers caused changes in the recombination frequency between pS and Y in chromosome 2, but not between pe and re in chromosome 5.——There were no differences in viability between individuals having the second chromosomes of the recombinant types [pS +, pY (H); pS +, + Y (L)] and those of the nonrecombinant types [pS Y, p + (H); pS Y, + + (L)] in both high and low lines. Mean recombination rates measured in cis [pS Y/p + (H); pS Y/+ + (L)] and trans [pS +/p Y (H); pS +/+ Y (L)] males were the same in the high but not in the low line. No segregation of a single recombination modifier was indicated by the distribution of recombination rates measured in trans males [pS +/p Y (H); pS +/+ Y (L)] of high and low lines. Accordingly, the recombination modifiers distributed on chromosome 2 in the heterozygous condition were not gross chromosomal aberrations, but polygenic factors in the low line.
EVIDENCE FOR THE INCLUSION OF CONTROLLING ELEMENTS WITHIN THE STRUCTURAL GENE AT THE WAXY LOCUS IN MAIZE
Authors: Echt Craig S , Schwartz Drew
Published: April 2021

Minimal limits for the structural gene at the waxy locus have been set by investigations of the protein product of the gene. An altered protein is produced by four of the waxy mutants including B3, a controlling-element mutation. All are similar to wild type in molecular weight as determined by electrophoresis in SDS acrylamide gels. At least three of the five wx controlling-element mutations studied have been shown to lie within the limits of the structural gene.
RECESSIVE ALLELES FOUND AT R AND C LOCI IN MAIZE STOCKS SHOWING ABERRANT RATIO AT THE A LOCUS
Authors: Brakke Myron K , Samson R G , Compton W A
Published: April 2021

Corn stocks showing virus-induced aberrant ratio (AR) at the "A"locus were iound to have recessive alleles at the Rand/or C loci. Since by the known pedigree these loci should be homozygous dominant, the results suggest an inactivation of maize genes by a mechanism as yet unknown. The presence of recessive alleles at these additional loci can explain the segregation ratios obtained in these particular stocks.
FURTHER STUDY ON THE GENETIC CORRELATION BETWEEN MEMBERS OF A MULTIGENE FAMILY
Authors: Ohta Tomoko
Published: April 2021

The extent of genetic similarity (in terms of identity coefficients) was investigated among members of a multigene family that is evolving under mutation, unequal crossing over and random genetic drift. The method of KIMURA and OHTA (1979) was used, but the possibility was incorporated that the length of the shift (in terms of the number of genes) involved in unequal crossing over can be more than one gene unit. Extensive numerical analyses show that, at equilibrium, the identity coefficients between two gene members are practically independent of their distance apart on the chromosome when the mean length of the shift at unequal crossing over is more than 10% of the total size of the family. In that case, the approximate treatment by OHTA (1980) is shown to be valid, but when the mean length of the shift is less than IO%, the average identity coefficient at equilibrium is underestimated. In order to clarify the effect of natural selection responsible for keeping the family size stable, Monte Carlo simulation studies were performed. The results indicate that the identity coefficients are not greatly influenced by natural selection on gene family size, particularly when the number of genes shifted is small compared to the family size. In addition, with sufficiently strongselection on family size, unequal crossovers with a large shift (such as with maximum shift of 90% of the family size) become ineffective and almost indisdnguishable from those with a small shift.
Progress in the face of cuts: a qualitative Nigerian case study of maintaining progress towards universal health coverage after losing donor assistance
Authors: Obi Uche Shalom , Ogbuoji Osondu , Mao Wenhui , Shahid Minahil , Onwujekwe Obinna , Yamey Gavin
Published: April 2021

In the coming years, about a dozen middle-income countries are excepted to transition out of development assistance for health (DAH) based on their economic growth. This anticipated loss of external funds at a time when there is a need for accelerated progress towards universal health coverage (UHC) is a source of concern. Evaluating country readiness for transition towards country ownership of health programmes is a crucial step in making progress towards UHC. We used in-depth interviews to explore: (1) the preparedness of the Nigerian health system to transition out of DAH, (2) transition policies and strategies that are in place in Nigeria, (3) the road map for the implementation of these policies and (4) challenges and recommendations for making progress on such policies. We applied Vogus and Graff’s expanded transition readiness framework within the Nigerian context to synthesize preparedness plans, gaps, challenges and stakeholders’ recommendations for sustaining the gains of donor-funded programmes and reaching UHC. Some steps have been taken to integrate and institutionalize service delivery processes toward sustainable immunization and responsive primary healthcare in line with UHC. There are ongoing discussions on integrating human immunodeficiency virus (HIV) services with other services and the possibility of covering HIV services under the National Health Insurance Scheme (NHIS). We identified more transition preparedness plans within immunization programme compared with HIV programme. However, we identified gaps in all the nine components of the framework that must be filled to be able to sustain gains and make significant progress towards country ownership and UHC. Nigeria needs to focus on building the overall health system by identifying systematic gaps instead of continuing to invest in parallel programmes. Programmes need to be consolidated within the overall health system, health financing priorities and policies. A comprehensive and functional structure will provide continuity even in the event of decreasing external funds or donor exits.
Sidney Holt’s legacy lives on in fisheries science
Authors: Anderson Emory D , Bartolino Valerio , Birchenough Silvana , Browman Howard I , Gibbs Mark , Hidalgo Manuel , Prellezo Raúl , Yates Katherine
Published: April 2021

On 22 December 2019, the world of fisheries science and whale conservation lost one of its most ardent champions with the passing of Sidney J. Holt. His career began in 1947 at the age of 21. Ten years later, he and his colleague Ray Beverton published their authoritative monograph on quantitative fish population dynamics. In 1953, he joined the Fisheries Division of the United Nations Food and Agriculture Organization and soon became heavily involved in assessing whale stocks under the auspices of the International Whaling Commission, a role that eventually led to advocating for animal rights and the cessation of commercial whaling. Later in life, he returned to fisheries assessment and management, particularly issues pertaining to the Common Fisheries Policy of the European Union, where he advocated for fishing mortality less than that associated with maximum sustainable yield. This themed set consists of articles written by authors who knew and collaborated with Sidney, who may have met him once or twice at an international meeting, and who only knew of him via his reputation and massive and influential list of publications. Their articles address a wide range of topics relating to his work throughout his career and reflect, in part, the influence that his work has had on thinking about quantitative modelling of animal populations.
Enhancing the ecosystem approach for the fishery for Antarctic krill within the complex, variable, and changing ecosystem at South Georgia
Authors: Trathan P N , Fielding S , Hollyman P R , Murphy E J , Warwick-Evans V , Collins M A
Published: April 2021

The objective of the ecosystem approach to fisheries management is to sustain healthy marine ecosystems and the fisheries they support. One of the earliest implementations was in the Southern Ocean, where decision rules and stock reference points were developed for managing the Antarctic krill fishery, together with an ecosystem-monitoring programme intended to aid management decisions. This latter component has not been incorporated directly into management, so here, we consider variability in the krill fishery at South Georgia, relating it to physical and biological monitoring indices, finding sea surface temperature to be a key correlate with both annual catch and long-term biological indices. Some indices from krill predators showed significant positive relationships with krill harvesting in the preceding winter, presumably indicative of the importance of winter foraging conditions. We explore how ecological structure affects results, examining two monitoring sites 100 km apart. Results suggest different biological conditions at the two sites, probably reflecting different scales of ecosystem operation, emphasizing that an appreciation of scale will enhance krill fishery management. Finally, in reviewing different drivers of ecological change, we identify important additional monitoring that would help better reflect ecosystem status, improve the utility of CEMP, providing information necessary for the ecosystem approach at South Georgia.
Engagement with rights in the making of counterterrorism legislation—Perspectives from three case studies: An introduction
Authors: Steiner Talya
Published: April 2021

Recent years have seen an emerging consensus on the important role non-judicial actors can play in protecting rights, and the potential benefits of integrating the compliance with constitutional standards into the legislative process. However, the study of actual practices of pre-enactment rights scrutiny has highlighted the need for deeper analysis of the factors that ultimately determine the extent to which rights considerations are effectively taken into account in policy design. The three case studies in this symposium contribute to the growing empirical literature on non-judicial constitutional review. Each article follows a particular counterterrorism legislation process and analyzes the ways in which consideration of rights effected or failed to effect policy design. These nuanced and empirically grounded perspectives on what rights review in the policymaking process actually entails help point out mechanisms that positively affect the ability to create proportionate policy, while documenting barriers at both the individual and organizational levels that can prevent rights from being afforded their optimal weight in the process. This introduction presents the main comparative insights arising from the three case studies in the symposium. The first point relates to the identity of and dynamic between the actors who engage with rights in the process, particularly the interaction between political and bureaucratic actors and its effect on the nature of the rights discourse and its impact. The second point characterizes three types of stages in the policy process—stages of deliberation, evaluation, and justification—and demonstrates how the nature of engagement with rights differs at each stage in terms of substance, scope, and influence. The third and final point relates to the ramifications of the layered nature of policymaking for the possibility of truly engaging with considerations of rights.
Trends in Prevalence and Characteristics of Resolved and Current Hepatitis B Among US-Born Persons: National Health and Nutrition Examination Survey, 2001–2018
Authors: Ly Kathleen N , Xing Jian , Spradling Philip R
Published: April 2021

Background

After decades of decline, US acute hepatitis B incidence flattened since 2011. In persons aged ≥40 years and in jurisdictions affected by the opioid crisis, there is an increase in new cases. Data suggest new infections are occurring among US-born persons.

Methods

We used National Health and Nutrition Examination Survey data during 2001–2018 to examine changes in total antibody to hepatitis B virus core antigen (anti-HBc) prevalence in US-born persons. During 2013–2018, the distribution of characteristics was examined.

Results

During 2001–2006, 2007–2012, and 2013–2018, anti-HBc prevalence was 3.5%, 2.5%, and 2.6% among US-born persons, respectively. This corresponded to 5.7 (range, 4.8–6.6) million US-born persons with resolved or current HBV infection during 2013–2018, including 344 600 persons aged 6–29 years. The largest increase and highest prevalence was among persons who reported injection drug use (IDU), which increased from 35.3% during 2001–2006 to 58.4% during 2013–2018 (P = .07).

Conclusions

Anti-HBc prevalence among US-born persons remained flat during the most recent period, coinciding with a doubling of prevalence among persons reporting IDU. These data are consistent with acute hepatitis B surveillance trends, showing increasing incidence in subpopulations where prevention could be strengthened.

Anti-HBc prevalence among US-born persons decreased from 2001–2006 to 2007–2012 and remained flat during 2013–2018, coinciding with a near doubling of prevalence among US-born persons reporting a history of injection drug use.
Biochemical characterization of OXA-244, an emerging OXA-48 variant with reduced β-lactam hydrolytic activity
Authors: Rima Mariam , Emeraud Cecile , Bonnin Rémy A , Gonzalez Camille , Dortet Laurent , Iorga Bogdan I , Oueslati Saoussen , Naas Thierry
Published: April 2021

Background

OXA-48-producing Enterobacterales have widely disseminated globally with an increasing number of variants identified. Among them, OXA-244 is increasingly reported, despite detection difficulties.

Objectives

To determine the steady-state kinetic parameters of OXA-244.

Methods

The blaOXA-244 gene was amplified, cloned into plasmids p-TOPO and pET41b+, and transformed into Escherichia coli TOP10 for MIC determination and E. coli BL21 DE3 for purification. Steady-state kinetic parameters and IC50s of clavulanic acid, tazobactam and NaCl were determined using purified OXA-244. Molecular modelling was also performed.

Results

A reduction in MICs of temocillin and carbapenems was observed in E. coli expressing OXA-244 as compared with OXA-48. The kinetic parameters revealed a reduced carbapenemase activity of OXA-244 as compared with OXA-48, especially for imipenem, which was 10-fold lower. Similarly, catalytic efficiency (kcat/Km) was reduced by 4-fold and 20-fold for ampicillin and temocillin, respectively. Kinetic parameters for cephalosporins were, however, similar. Molecular modelling studies evidenced the key role of R214 in OXA-48, establishing salt bridges with D159 and with the carboxylate group of the R1 substituent of temocillin. These interactions are not possible with G214 in OXA-244, explaining the reduced affinity of temocillin for this enzyme. The R214G mutation in OXA-244 is also likely to induce changes in the active site’s water network that would explain the decrease in the hydrolysis rate of carbapenems.

Conclusions

Our data confirm that the R214G mutation (present in OXA-244) results in reduced carbapenem- and temocillin-hydrolysing activity, confirming the crucial role of residue 214 in the hydrolysis of these substrates by OXA-48-like β-lactamases.
Evaluation of Electrical Burn Injuries in Iran: A 7-Year Retrospective Study
Authors: Vaghardoost Reza , Saraee Amir , Ghavami Yaser , Sobouti Behnam
Published: April 2021

Electrical burn injuries can cause devastating and debilitating morbidities and impairments for patients. This cross-sectional descriptive study was performed on electrical burn patients hospitalized from 2014 to 2019 to evaluate electrical burn injuries’ epidemiology and characteristics. A total number of 726 patients with the mean age of 31.17 years were evaluated for electrical burn injuries. Mean total burn surface area (TBSA) was 16.61 ± 12.56. Most victims were male (696 cases, 95.7%) and most patients did not have a constant job (n = 458, 63%). Most affected burn sites were hands (28.6%) and upper limbs (27.8%). A total number of 89 (12.2%) patients suffered amputations with the hand fingers (64 cases) as the most common site. Low-voltage injuries were more common (n = 649, 89%). Most incidents happened at the workplace (n = 459, 63%). Comparison of patients with high-voltage and low-voltage injuries showed significant correlations and statistical difference between these two groups regarding TBSA, mean hospital stays, escharectomy, fasciotomy, amputations, debridement, fracture, and mortality rate (P = .001). Our observation revealed that electrical burn injuries are still significant causes of morbidity and mortality among trauma patients. In contrast to previous studies, low-voltage injuries were more common than high-voltage ones. We propose improvements in the manufacturing of electrical appliances; paying attention to safety measures will reduce the number of incidents. Moreover, training and education play important roles in reducing the number of incidents and mortality rates.
Flexure mechanics of nonlocal modified gradient nano-beams
Authors: Faghidian S Ali
Published: April 2021

Two frameworks of the nonlocal integral elasticity and the modified strain gradient theory are consistently merged to conceive the nonlocal modified gradient theory. The established augmented continuum theory is applied to a Timoshenko–Ehrenfest beam model. Nanoscopic effects of the dilatation, the deviatoric stretch, and the symmetric rotation gradients together with the nonlocality are suitably accommodated. The integral convolutions of the constitutive law are restored with the equivalent differential model subject to the nonclassical boundary conditions. Both the elastostatic and elastodynamic flexural responses of the nano-sized beam are rigorously investigated and the well posedness of the nonlocal modified gradient problems on bounded structural domains is confirmed. The analytical solution of the phase velocity of flexural waves and the deflection and the rotation fields of the nano-beam is detected and numerically illustrated. The transverse wave propagation in carbon nanotubes is furthermore reconstructed and validated by the molecular dynamics simulation data. Being accomplished in revealing both the stiffening and softening structural responses at nano-scale, the proposed nonlocal modified gradient theory can be beneficially implemented for nanoscopic examination of the static and dynamic behaviors of stubby nano-sized elastic beams.
Introgression ofASIPandTYRP1Alleles Explains Coat Color Variation in Valais Goats
Authors: Henkel Jan , Dubacher Alexandra , Bangerter Erika , Herren Ursula , Ammann Philippe , Drögemüller Cord , Flury Christine , Leeb Tosso
Published: April 2021

The Valais Blackneck goat is a Swiss goat breed with a characteristic coat color phenotype. Before the revision of the breed standard in 1938, 4 different color varieties of Valais goats were known. Besides Blackneck animals resembling the modern breed standard, the brown and white Copperneck goat, the white Capra Sempione, and the greyish Grüenochte comprised the historic Valais goats. The brown pigmentation of Copperneck goats had previously been traced back to an introgression of a mutant TYRP1 allele from Toggenburg goats. In the present study, we identified additional introgression events of distinct ASIP alleles causing the remaining 2 rare coat color patterns within the Valais Blackneck goat breed. We identified the introgression of the AWt allele from Appenzell or Saanen goats in white Capra Sempione goats. Similarly, introgression of the Apc allele from Peacock goats resulted in the greyish Grüenochte phenotype. These results demonstrate past hybridization events between breeds that are separated today. A perfect genotype-phenotype association in 393 Valais goats supported the causality of the genotyped variants for the different coat color phenotypes. Our study gives insights into the introgression of functionally relevant copy number variant (CNV) alleles controlling pigmentation between goat breeds with strikingly different coat color patterns.
WTO Litigation and SEZs: Determining the Scope of Exceptional Trade Unilateralism
Authors: Nedumpara James J , Gupta Manya , Choukroune Leïla
Published: April 2021

The incentives available to enterprises located in special economic zones can be classified into three broad categories, namely, (i) fiscal incentives in the nature of tax incentives and exemption of duties, (ii) non-fiscal incentives in the form of infrastructural and developmental facilities, and (iii) regulatory incentives covering lenient and flexible compliance requirements. The fiscal incentives in special economic zones are, to an extent, regulated by the law of the World Trade Organization although direct challenges of special economic zone policies have been very few or non-existent. The absence of legal challenges led to a number of World Trade Organization members pursuing unilateral trade policies within their special economic zones. However, the recent World Trade Organization Panel findings in India—Export Related Measures appear to highlight the thin margin for trade unilateralism especially in relation to fiscal incentives in special economic zones. In the above context, this article examines the permissible limits of trade unilateralism, in the context of special economic zones, by providing a fresh understanding of the disciplines under international trade law and the available jurisprudence. It focuses, in particular, on the precise contours of permissible trade unilateralism exercised by World Trade Organization members when granting fiscal incentives. In doing so, this article also examines the concept of exception as a manifestation of unilateralism in International Economic Law.
Effect of Zolpidem Tartrate on the Developmental Rate of Forensically Important FliesChrysomya megacephala(Diptera: Calliphoridae) andChrysomya saffranea
Authors: Al-Shuraym Laila A , Al-Mekhlafi Fahd A , Abd Al Galil Fahd Mohammed , Alhag Sadeq K , Al-Keridis Lamya Ahmed , Ali El Hadi Mohamed Rania , Wadaan Muhammad A , Al-Khalifa Mohammed S
Published: April 2021

Entomotoxicology is an emerging science in the forensic investigation of death; it now influences judicial activities. Briefly, carrion flies ingest various chemicals as they feed on a cadaver. In entomotoxicology, such toxicological compounds are qualitatively and quantitatively analyzed in insects recovered from carrion. Some of these chemicals can disrupt flies’ cellular physiology, leading to acceleration or delay in their developmental rate. In this study, the effect of zolpidem-contaminated tissue on the dipteran flies Chrysomya megacephala (Fabricius 1794) and Chrysomya saffranea (Bigot 1877) was assessed. Zolpidem tartrate is a sedative-hypnotic compound commonly used to treat anxiety and sleeping disorders, but it is associated with death from suicide. The effects were tested by providing the flies with liver tissue treated with various concentrations of zolpidem tartrate. The morphological parameters and development rate for all life cycle stages of treated insects were determined and used to estimate postmortem intervals. Results showed that the morphological parameters, i.e., weight, width, and length and rate of development of C. megacephala and C. saffranea was negatively associated with zolpidem tartrate concentration of C. saffranea, were negatively associated with the concentration of zolpidem tartrate, indicating that arthropod evidence evaluation can help establish the cause and time of death.