bluuebunny/crossref_metadata_2025_split huggingface dataset:
A MODEL FOR ANALYSIS OF POPULATION STRUCTURE
Authors: Rothman Edward D , Sing Charles F , Templeton Alan R 
Published: January 2021

ABSTRACT
Arguments have been presented for the appropriateness of a multinomial Dirichlet distribution for describing single-locus genotypic frequencies in a subdivided population. This distribution is defined as a function of allele frequency, the average (over the entire population) inbreeding coefficient and the correlation between genotypes within a subdivision. Alternative parameterizations and their genetic interpretations are given.—We then show how information from a sample drawn from this subdivided population, in the absence of pedigrees, can be combined with the multinomial Dirichlet model to form a likelihood function. This likelihood function is then used as the basis for estimation and testing hypotheses concerning the genetic parameters of the model. Comparisons of this approach to the alternative procedure of COCKEXHAM (1969) and (1973) are made using human data obtained from Tecumseh, Michigan and Monte Carlo simulations.—Finally, implications of these results to statistical inference and to mutation rates are presented.
FURTHER EVIDENCE FOR SELECTIVE DIFFERENCES BETWEEN ISOALLELES IN DROSOPHILA
Authors: Wills Christopher , Phelps Julia , Ferguson Richard 
Published: January 2021

ABSTRACT
A number of separate strains of Drosophila pseudoobscura were inbred for 38 generations of brother-sister mating with forced heterozygosity for two alleles of either the octanol dehydrogenase or esterase-5 locus. Crosses were set up within each of these inbred lines such that simple mendelian ratios were expected, and eggs from these crosses were placed on media with additions of simple chemicals likely to interact with alleles of the two loci—octanol and ethanol for the ODH locus and tributyrin and triacetin for the E-5 locus. Similar crosses were set up involving parental flies with normally heterozygous genetic background as a control.—Significant deviations from mendelian expectation were observed in inbred E-5 flies grown on tributyrin, inbred ODH males grown on octanol, and inbred ODH females grown on ethanol. There was also a strong effect of octanol medium on males of one of the inbred E-5 lines, and a weak effect of tributyrin medium on ODH inbred females.—The probability that these results reflect interactions between these loci and the environment is assessed in the light of differences between the present results and those obtained at earlier stages of inbreeding.
EVIDENCE FOR THE SINGLE PHASE PAIRING THEORY OF MEIOSIS
Authors: Novitski E 
Published: January 2021

ABSTRACT
The segregation pattern of an attached X chromosome with several Y-autosome translocations conflicts with the expectations based on the distributive pairing hypothesis because the chromosomes segregating from the translocation configuration include both exchange and non-exchange chromosomes. The results of the second experiment involving three compound chromosomes go even further; they suggest that the essential association which determines the segregation of nonhomologous elements is in fact set up prior to the time of crossing over.
RECIPROCAL TRANSLOCATIONS AND TRANSLOCATION DISOMICS OF ASPERGILLUS AND THEIR USE FOR GENETIC MAPPING
Authors: Käfer Etta 
Published: January 2021

ABSTRACT
Two new techniques are described for genetic mapping of reciprocal translocations in A. nidulans, which can be used to locate centromeres and meiotically unlinked markers. They both make use of unbalanced disomics from heterozygous translocation crosses. These are mainly hyperhaploids of two classes: either typical-looking n + 1 with a normal chromosome in addition to a haploid set containing the translocation, or translocation disomics. When large chromosome segments are involved, such disomics, as well as stable aneuploids and duplication types, show characteristic phenotypes and can be classified visually. The first method maps translocation breaks qualitatively, since translocated markers can be identified when translocation disomics are analyzed for heterozygous markers. The second method measures meiotic linkage of any marker to the translocation breaks when allele ratios in the balanced haploid sectors of either or both classes of disomics are determined: linked markers show reciprocal deviations from 1:1—In addition, it can be shown that frequencies of nondisjunction and recovery of specific translocation disomics both depend on the relative position of the break within a chromosome arm. Such information can provide a rough estimate of the positions of breaks for a new translocation.—Using these techniques, as well as mitotic mapping in homo- and heterozygous translocation diploids, four reciprocal translocations were mapped. From these results, information on the sequence and orientation of most of the "meiotic fragments" of the current maps (groups III, VI, VII and VIII) was obtained, and the position of the centromeres of groups VI and VII were identified. Translocation disomics are also used to map meiotically unlinked single genes, e.g. oliA of group VII, to specify chromosome segments.
CHEMICAL SELECTION OF MUTANTS THAT AFFECT ALCOHOL DEHYDROGENASE IN DROSOPHILA II. USE OF 1—PENTYNE—3—Ol
Authors: O'Donnell Janis , Gerace Larry , Leister Flora , Sofer William 
Published: January 2021

ABSTRACT
We describe a procedure for the selection of alcohol dehydrogenase negative mutants in Drosophila. The method consists of exposing eggs and larvae to low concentrations of 1-pentyne-3-ol dissolved in the culture medium. Only those flies with greatly reduced levels of alcohol dehydrogenase activity survive. In addition, genotypically negative flies die if their mothers are alcohol dehydrogenase positive. Using this procedure and formaldehyde to generate mutants, we were able to detect seven alcohol dehydrogenase negative mutants out of 350,000 individuals subjected to selection. At least five of the mutants contain small deletions that include the alcohol dehydrogenase locus.
A NEW METHOD FOR MUTANT SELECTION IN SACCHAROMYCES CEREVISIAE
Authors: Henry Susan A , Horowitz Bernard 
Published: January 2021

ABSTRACT
A new method for the selection of auxotrophic, antibiotic- and temperature-sensitive mutants in Saccharomyces cerevisiae is reported. The technique is based upon the observation that certain fatty acid auxotrophs of yeast die when deprived of fatty acid only under conditions supporting growth. When macromolecular synthesis is blocked, the fatty acid-starved cells survive. By appropriate manipulation of a fatty acid-requiring strain enrichment as great as 75-fold was achieved for certain classes of auxotrophic mutants. An enrichment of approximately 100-fold is possible for some antibiotic-sensitive mutants. Selection for temperature-sensitive mutants, however, resulted in less than a 2-fold increase in the frequency of such mutants, probably because of the heterogeneity of this mutant category. It is likely that only that fraction of temperature-sensitive mutations which rapidly and reversibly blocks macromolecular synthesis is selected by this technique.
A REVISION OF THE CYTOLOGY AND ONTOGENY OF SEVERAL DEFICIENCIES IN THE 3A1—3C6 REGION OF THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Kaufman T C , Shannon M P , Shen M W , Judd B H 
Published: January 2021

ABSTRACT
The cytology and developmental attributes of 18 deficiency mutations in the 3A1-3C6 region of the salivary gland X chromosome of Drosophila melanogaster have been investigated. The cytological limits of several older deficiencies have been revised and clarified and several new deficiencies are characterized. The deficiency mutants, with one possible exception, show a lethal phase in the late embryonic period or the early first larval instar. In contrast, the earliest acting point mutation lethals exposed by these deficiencies generally exhibit a somewhat later, post-embryonic lethality, perhaps indicating that the deficiencies are having some cumulative or synergistic impact on development. However, even with this difference in time of lethality, it is still possible to conclude that it is not the absolute size of the deficiency but rather the character of the loci deleted that determines the impact on development. Observations on the morphology of lethal embryos shows that while this analysis is internally consistent, it does not agree with earlier work. None of the 3A1-3C6 deficiencies causes any major teratologies during embryogenesis. Furthermore, the "earliest acting" gene in this region does not lie in band 3C1 but is most likely associated with bands 3A8-10.
CLONAL AGE AND THE PROPORTION OF DEFECTIVE PROGENY AFTER AUTOGAMY IN PARAMECIUM AURELIA
Authors: Fukushima Shinichi 
Published: January 2021

ABSTRACT
The relation of mortality and the proportion of progeny with reduced fission after autogamy to the clonal age in Paramecium aurelia was investigated. This relation is not linear but the proportion of defective progeny increases stepwise. The observations are in agreement with those expected from the calculations of the number of deleterious mutations in the micronucleus.
CROSSING OVER AND DIPLOID EGG FORMATION IN THE ELONGATE MUTANT OF MAIZE
Authors: Nel P M 
Published: January 2021

ABSTRACT
Rhoades (1941) found recombination in the proximal regions of chromosome 5 to be higher in male than in female flowers. Two explanations were proposed to account for the lower female values, namely: (1) there is a basic difference in rates of crossing over in mega- and microsporocytes, or (2) selective orientation of the chromosome 5 bivalent on the meiotic spindle leads to the preferential segregation of noncrossover chromatids to the basal megaspore. These alternatives have been tested by carrying out a half-tetrad analysis of the diploid eggs produced by plants homozygous for the recessive elongate (el) allele. The A2—Bt crossover values determined from the diploid eggs of elongate plants were much lower than those calculated from haploid sperm of both El el and el el plants. Since male and female flowers should have similar cross-over values if the orientation hypothesis were correct, it was concluded that the amount of crossing over in the A2-Bt region of chromosome 5 is intrinsically higher in male than in female meiocytes. In the analysis of diploid eggs the use of the Bt locus, which marks the centric region of chromosome 5, provided information on the origin of diploid eggs. The genotypic constitution of 425 diploid eggs was ascertained. Of these, 20.4% were Bt bt. They could not be accounted for by failure of the second meiotic division or by replication during the interphase between the two meiotic divisions, but are expected if there is a single division with an equational separation of the centromere regions of chromosome 5. The Bt Bt and bt bt genotypes arise from a disjunctional separation. It is proposed that diploid eggs are produced by an abnormal meiosis in which there is one division with either disjunctional or equational separation. Disjunctional separation is more frequent but the ratio of the two types varies from ear to ear. Recombination in the A2-Bt-Pr region of chromosome 5 was found to be higher in the haploid gametes of elongate homozygotes than in El El and El el plants. On the other hand, crossing over was reduced in the Sh-Bz segment of chromosome 9 in elongate plants, but the adjacent Bz—Wx interval was unaffected.
EXPRESSION IN ORGAN CULTURE OF AGOUTI LOCUS GENES OF THE MOUSE
Authors: Knisely A S , Gasser David L , Silvers Willys K 
Published: January 2021

ABSTRACT
Cleffmann (1963) reported that pigment cells of the lethal yellow (Ay/a) genotype change to black immediately upon cultivation, and continue to produce black pigment unless sulfhydryl reagents are added to the culture medium. We have attempted to repeat this observation and have not been able to do so. We also have been unable to induce the synthesis of yellow pigment by adding glutathione to cultures of agouti (A/A) skin. We therefore suggest that hypotheses which attempt to explain the action of agouti locus genes on the basis of effects of sulfhydryl compounds be considered with caution.
A GENETIC ANALYSIS OF PHOTOTACTIC BEHAVIOR IN DROSOPHILA MELANOGASTER I. SELECTION IN THE PRESENCE OF INVERSIONS
Authors: Markow Therese Ann 
Published: January 2021

ABSTRACT
The effectiveness of selection for positive and negative phototactic behavior in populations of Drosophila melanogaster heterozygous for various multiple inversions was compared using the method of realized heritability. Selection in the presence of FM6, SM1 or TM3 alone was as effective as in populations carrying no inversions. However, the presence of FM6 and TM3 together reduced the effectiveness of selection for photopositive behavior and FM6 and SM1 and TM3 restricted the response to selection for negative phototactic behavior. The results are discussed in terms of the organization of genes influencing phototactic behavior in this species.
GENETIC CONTROL OF RADIATION SENSITIVITY IN SCHIZOSACCHAROMYCES POMBE
Authors: Nasim A , Smith B P 
Published: January 2021

ABSTRACT
Genetic analysis of a large number of radiation-sensitive mutants of S. pombe, isolated in different laboratories, showed that these isolates represent 22 non-allelic loci. The mutants were shown to fall into three distinct classes concerning response to UV and ionizing radiation, including two mutants which are primarily sensitive to ionizing radiation but not to UV. Single-gene mutants were crossed to obtain supersensitive double mutants. Such double mutants showed a marked increase in sensitivity to a variety of inactivating agents as compared to the parental strains. The isolation of three classes of radiation-sensitive mutants and the construction of double mutants implies the presence of multiple pathways in S. pombe for repair of radiation-induced damage. The bearing of these data on cellular repair mechanisms in eukaryotes is discussed.
SEX CHROMOSOME MEIOTIC DRIVE SYSTEMS IN DROSOPHILA MELANOGASTER I. ABNORMAL SPERMATID DEVELOPMENT IN MALES WITH A HETEROCHROMATIN-DEFICIENT X CHROMOSOME (sc
4
sc
8)
Authors: Peacock W J , Miklos George L Gabor , Goodchild D J 
Published: January 2021

ABSTRACT
The meiotic drive characteristics of the In(1)sc4Lsc8R/Y system have been examined by genetic analysis and by light and electron microscopy. sc4sc8/Y males show a direct correlation between nondisjunction frequency and meiotic drive. Temperature-shift experiments reveal that the temperature-sensitive period for nondisjunction is at meiosis, whereas that for meiotic drive has both meiotic and post-meiotic components. Cytological analyses in the light and electron microscopes reveal failures in spermiogenesis in the testes of sc 4 sc 8 males. The extent of abnormal spermatid development increases as nondisjunction becomes more extreme.
Resolution Status and Age as Moderators for Interpersonal Everyday Stress and Stressor-Related Affect
Authors: Witzel Dakota D , Stawski Robert S 
Published: January 2021

Abstract

Objectives
To examine stressor characteristics (i.e., stressor resolution) and individual differences (i.e., age) as moderators of affective reactivity and residue associated with everyday interpersonal stressors, including arguments and avoided arguments.

Method
A sample of 2,022 individuals participated in the second wave of the National Study of Daily Experiences (meanage = 56.25, range = 33–84). Over 8 consecutive evenings, participants completed the Daily Inventory of Stressful Experiences and self-report measures of stressor resolution status and daily negative affect (NA) and positive affect (PA). Using multilevel modeling, we examined whether increases in daily NA and decreases in daily PA associated with arguments and avoided arguments occurring on the same day (i.e., reactivity) or the day before (i.e., residue) differed depending on resolution of the interpersonal stressor. We further examined whether such stressor resolution effects were moderated by age.

Results
Resolution significantly dampened NA and PA reactivity and residue associated with arguments; NA reactivity associated with avoided arguments (ps &lt; .05). Older age was associated with being more likely to resolve both arguments and avoided arguments (ps &lt; .05) and did reduce reactivity associated with avoided arguments. Older age did not moderate PA reactivity or NA or PA residue associated with either arguments or avoided arguments (ps &gt; .05).

Discussion
Unresolved everyday arguments and avoided arguments are differentially potent in terms of affective reactivity and residue, suggesting resolution may be crucial in emotional downregulation. Future work should focus on exploring resolution of other everyday stressors to garner a comprehensive understanding of what characteristics impact stressor–affect associations and for whom.
Coping of Older Adults in Times of COVID-19: Considerations of Temporality Among Dutch Older Adults
Authors: Verhage Miriam , Thielman Lucia , de Kock Lieke , Lindenberg Jolanda 
Published: January 2021

AbstractObjectivesGlobally, mitigation measures during the coronavirus disease 2019 (COVID-19) pandemic have focused on protecting older adults. Earlier disaster studies have shown the importance of including older peoples’ voices to prevent secondary stressors, yet these voices have received little attention during this pandemic. Here, we explore how Dutch older adults view this crisis and cope with measures to contribute to our understanding of coping of older adults in general and during disaster situations more specifically.MethodQualitative study using semistructured telephone interviews with 59 diverse older adults aged 54–95 throughout the Netherlands.ResultsOlder adults typify this crisis as ungraspable, disrupting their daily and social lives. Despite filling their lives with activities, they experience loss or lack of purpose. They try to follow measures to decrease infection risk and gain control, and use problem- and emotion-focused coping strategies. Emotion-focused strategies used were interpreting their personal vulnerability, self-enhancing comparisons, acceptance, and distraction. In the latter 2 strategies, the temporary nature of measures was emphasized.DiscussionOlder adults describe this crisis consistently with earlier findings from disaster studies. They use known coping strategies, but emphasize the duration in relation to their expectation of temporality. This underscores a dynamic, processual approach toward coping that incorporates temporal dimensions such as duration and order. Our findings stress the importance of acknowledging heterogeneity among older adults and adjusting communication about mitigation measures to decrease insecurity and increase resonance. This may make COVID-19 mitigation measures more manageable and age-responsible and allow older adults to start living again.
A plasma metabolomic signature of Leber hereditary optic neuropathy showing taurine and nicotinamide deficiencies
Authors: Bocca Cinzia , Le Paih Victor , Chao de la Barca Juan Manuel , Kouassy Nzoughet Judith , Amati-Bonneau Patrizia , Blanchet Odile , Védie Benoit , Géromin Daniela , Simard Gilles , Procaccio Vincent , Bonneau Dominique , Lenaers Guy , Orssaud Christophe , Reynier Pascal 
Published: January 2021

Abstract
Leber’s hereditary optic neuropathy (LHON) is the most common disorder due to mitochondrial DNA mutations and complex I deficiency. It is characterized by an acute vision loss, generally in young adults, with a higher penetrance in males. How complex I dysfunction induces the peculiar LHON clinical presentation remains an unanswered question. To gain an insight into this question, we carried out a non-targeted metabolomic investigation using the plasma of 18 LHON patients, during the chronic phase of the disease, comparing them to 18 healthy controls. A total of 500 metabolites were screened of which 156 were accurately detected. A supervised Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) highlighted a robust model for disease prediction with a Q2 (cum) of 55.5%, with a reliable performance during the permutation test (cross-validation analysis of variance, P-value = 5.02284e−05) and a good prediction of a test set (P = 0.05). This model highlighted 10 metabolites with variable importance in the projection (VIP) &gt; 0.8. Univariate analyses revealed nine discriminating metabolites, six of which were the same as those found in the Orthogonal Projections to Latent Structures Discriminant Analysis model. In total, the 13 discriminating metabolites identified underlining dietary metabolites (nicotinamide, taurine, choline, 1-methylhistidine and hippurate), mitochondrial energetic substrates (acetoacetate, glutamate and fumarate) and purine metabolism (inosine). The decreased concentration of taurine and nicotinamide (vitamin B3) suggest interesting therapeutic targets, given their neuroprotective roles that have already been demonstrated for retinal ganglion cells. Our results show a reliable predictive metabolomic signature in the plasma of LHON patients and highlighted taurine and nicotinamide deficiencies.
The Marmoset: The Next Frontier in Understanding the Development of the Human Brain
Authors: Homman-Ludiye Jihane , Bourne James A 
Published: January 2021

Abstract
Rodent models, particularly mice, have dominated the field of developmental neuroscience for decades, like they have in most fields of biomedicine research. However, with 80 million years since rodents and primates last shared a common ancestor, the use of mice to model the development of the human brain is not without many shortcomings. The human brain diverges from the mouse brain in many aspects and is comprised of novel structures as well as diversified cellular subtypes. While these newly evolved features have no equivalent in rodents, they are observed in nonhuman primates. Therefore, elucidating the cellular mechanisms underlying the development and maturation of the healthy and diseased human brain can be achieved using less complex nonhuman primates. Historically, macaques were the preferred nonhuman primate model. However, over the past decade, the New World marmoset monkey (Callithrix jacchus) has gained more importance, particularly in the field of neurodevelopment. With its small size, twin or triplet birth, and prosocial behavior, the marmoset is an ideal model to study normal brain development as well as neurodevelopmental disorders, which are often associated with abnormal social behaviors. The growing interest in the marmoset has prompted many comparative studies, all demonstrating that the marmoset brain closely resembles that of the human and is perfectly suited to model human brain development. The marmoset is thus poised to extend its influence in the field of neurodevelopment and will hopefully fill the gaps that the mouse has left in our understanding of how our brain forms and how neurodevelopmental disorders originate.
H∞ estimation for non-linear positive switched systems with time-varying delay
Authors: Li Shuo , Chen Yun , Xue Anke 
Published: January 2021

Abstract
For non-linear positive switched systems (NPSSs) with time-varying delay, the $H_{\infty }$ estimation problem is addressed in this paper. Firstly, in light of T-S fuzzy modeling method, the considered NPSS is equivalently transformed into a switched positive T-S fuzzy system. Then, a less conservative $H_{\infty }$ performance co1ndition is provided for the error system via presenting a new piecewise quadratic copositive Lyapunov–Krasovskii functional. Furthermore, an observer is constructed to make the underlying system exponentially stable with a preset $H_{\infty }$ performance and an iterative optimization algorithm is proposed to obtain the observer parameters. To verify the effectiveness of the theoretical results, two examples are finally presented.