bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geotechnical properties of lateritic soil stabilized with sugarcane straw ash
Authors: Olowofoyeku A , Ofuyatan O , Oluwafemi J , Iroaganachi P 
Published: January 2021

Abstract
An increase in population with the demand of a wider road and also maintenance of transportation infrastructure has been alarming over the past few decades. Owing to this fact investigation will be carried out on laterite soil to improve the geotechnical properties of the soil to be able to stabilize the soil to withstand the load coming on it. In this investigation agricultural waste (sugarcane straw ash) will be used at varying percentage of 0, 4, 8, 10 and 12 to stabilized the laterite soil and improve the properties of the soil. The result indicates that with the increase of SCSA in the soil sample at 4% proportion ratio the soil strength is increased and at 12% it reduced drastically. The result of the tests shows that the strength of the soil is good when 4% SCSA are added. The optimum substitute increased the load bearing capacity of the soil thereby making an improvement to the lateritic soil.
Numerical approximation of second-order boundary value problems via hybrid boundary value method
Authors: Akinlabi G. O. , Busari A. A. , Abatan O. G. , Odunlami O. A. 
Published: January 2021

AbstractHybrid Boundary Value Method (HyBVM) is a new scheme, which is based on Linear Multistep Method (LMM). The HyBVM is the hybrid version of the Boundary Value Methods (BVMs) which are methods derived to overcome the limitations of the LMMs. This new scheme shares the same characteristic with the Runge Kutta method as data are utilized at off-step points. In this work, we apply this method to two second order Boundary Value Problems (BVPs) with mixed boundary conditions and the results are efficient when compared to other BVMs in literature.
Optimization and analysis of the packet switched network with focus on the 3G network
Authors: Oje A. A. , Edeki S. O. 
Published: January 2021

Abstract
A class of computer communications network that groups and passes data in the form of s mall packets is referred to as the PSN.. This research aimed at analyzing the Network output on 3 G Network, which is using Packet Switching. The Performance indices observed include the Received Signal Code Power (RSCP), the Energy per Chip to Spectral Noise density ratio, Handover Success Rate, and the Throughput. These indices were used to define the Coverage, accessibility, and data throughput of the Network.
Coupled method for the solution of a one-dimensional heat equation with axial symmetry
Authors: Edeki S. O. , Ogunniyi P. O. , Imaga O. F. 
Published: January 2021

Abstract
In this article, we implement the Projected Differential Transform Method (PDTM) coupled with Laplace Transform Method (LTM), hereby referred to as LPDTM, to solve a one-dimensional heat model (equation) with axial symmetry. Using the proposed framework (LPDTM), the exact solution (results) are obtained with convenience. It is noted that the suggested methodology performs very well and gives rapidly converging series solutions with less computational activities.
Nudging health care workers towards a flu shot: reminders are accepted but not necessarily effective. A randomized controlled study among residents in general practice in France
Authors: Barbaroux Adriaan , Benoit Laurie , Raymondie Romain A , Milhabet Isabelle 
Published: January 2021

AbstractBackgroundA nudge corresponds to any procedure that influences choice architecture, without using persuasion or financial incentives. Nudges are effective in increasing vaccination with heterogeneous levels of acceptability.ObjectiveTo evaluate the effectiveness and acceptability of a nudge promoting influenza vaccination for general practice trainees, also called residents.MethodsThe hypothesis was that a reminder would be efficient and accepted and that prior exposure to a nudge increases its acceptability. Residents were randomly divided into three parallel experimental arms: a nudge group, a no-nudge group and a control group in order to evaluate the Hawthorne effect. The nudge consisted of providing a paper form for the free delivery of the vaccine and contacts for occupational health services.ResultsThe analysis included 161 residents. There was a strong consensus among the residents that it is very acceptable to nudge their peers and patients. Acceptability was better with residents exposed to the nudge and with residents included in step 1 (Hawthorne effect). The nudge did not increase vaccination coverage.ConclusionThe failure of this nudge highlights the importance of matching an intervention to the population’s needs. The experimental approach is innovative in this context and deserves further attention.ClinicalTrials.gov pre-registrationNCT03768596
Evolution of Chi motifs in Proteobacteria
Authors: Buton Angélique , Bobay Louis-Marie 
Published: January 2021

AbstractHomologous recombination is a key pathway found in nearly all bacterial taxa. The recombination complex not only allows bacteria to repair DNA double-strand breaks but also promotes adaption through the exchange of DNA between cells. In Proteobacteria, this process is mediated by the RecBCD complex, which relies on the recognition of a DNA motif named Chi to initiate recombination. The Chi motif has been characterized in Escherichia coli and analogous sequences have been found in several other species from diverse families, suggesting that this mode of action is widespread across bacteria. However, the sequences of Chi-like motifs are known for only five bacterial species: E. coli, Haemophilus influenzae, Bacillus subtilis, Lactococcus lactis, and Staphylococcus aureus. In this study, we detected putative Chi motifs in a large dataset of Proteobacteria and identified four additional motifs sharing high sequence similarity and similar properties to the Chi motif of E. coli in 85 species of Proteobacteria. Most Chi motifs were detected in Enterobacteriaceae and this motif appears well conserved in this family. However, we did not detect Chi motifs for the majority of Proteobacteria, suggesting that different motifs are used in these species. Altogether these results substantially expand our knowledge on the evolution of Chi motifs and on the recombination process in bacteria.
SPECIALIZED TRANSDUCTION WITH Λplac5: INVOLVEMENT OF THE RecE AND RecF RECOMBINATION PATHWAYS
Authors: Porter Ronald D 
Published: January 2021

ABSTRACT
Several aspects of the recombination resulting from λplac5 transduction were investigated in strains of Escherichia coliK-12 that use the RecE or RecF recombination pathways. In a RecBC pathway strain, F42lac recombination with λplac5 is 20- to 50-fold higher than chromosomal lac times λplac5 recombination, and this recombination enhancement is largely dependent on constitutive expression of F42lac fertility functions. Here, it was observed that F42lac fertility functions do not effect the ability of F42lac to recombine with λplac5 in a RecE or RecF pathway strain. Therefore, the enhancement observed in a Rec+ (or RecBC pathway) strain is directly dependent on the recBC gene product. The end product of recombination between λplac5 and either F42lac or chromosomal lac in RecE and RecF pathway strains was monitored by scoring for addition and substitution transductants. It was observed that the percentage of addition transductants was lower in all cases for RecE and RecF pathway strains as compared with RecBC pathway or a recB strain. It is concluded that the introduction of sbcA or sbcB into a recB strain produces a change in recombination mechanism that is reflected in the nature of the end product of recombination.
CENTROMERE ORIENTATION OF QUADRIVALENTS OF HETEROZYGOUS TRANSLOCATIONS AND AN AUTOPLOID OF GOSSYPIUM HIRSUTUM L
Authors: Endrizzi J E , Ray D T , Gathman A C 
Published: January 2021

ABSTRACT
Cytological observations of quadrivalents of heterozygous translocations in Gossypium hirsutum L. demonstrate that, in addition to alternate-1 and alternate-2 orientations, a third alternate orientation (alternate-3), which occurs as a three-dimensional, V-type configuration, can be identified.—Two additional types of disjunctions, the centromere orientations of which are rotational modifications of either adjacent or alternate configurations, were also observed in quadrivalents of a translocation heterozygote. These two types are rare, and both appear in the form of the Roman numeral X. The X and the alternate-3 types also occur in quadrivalents of an autoploid of G. hirsutum.—The two X types, along with adjacent-1, adjacent-2, alternate-1 and alternate-2 orientations, represent the six possible types of planar 2 x 2 random orientation of the four centromeres of a quadrivalent. Including the three-dimensional alternate-3 type, there are seven types of orientation.
A COMPARISON OF MUTATION RATES FOR SPECIFIC LOCI AND CHROMOSOME REGIONS IN DYSGENIC HYBRID MALES OF DROSOPHILA MELANOGASTER
Authors: Simmons Michael J , Raymond John D , Johnson Nancy A , Fahey Thomas M 
Published: January 2021

ABSTRACT
The mutation rates of specific loci and chromosome regions were estimated for two types of dysgenic hybrid males. These came from crosses between P or Q males and M females in the P-M system of hybrid dysgenesis. The M × P hybrids were the more mutable for each of the loci and chromosome regions tested. The Beadex locus was highly mutable in these hybrids but did not mutate at all in the sample of gametes from the M × Q hybrids. The singed locus had 75% of the mutability of Beadex in the M × P hybrids; it was also mutable in the M × Q hybrids. The white locus was only slightly mutable in the M × P hybrids and not at all mutable in the M × Q hybrids. The mutations in singed and white probably arose from the insertion of P elements into these loci; the mutations at Beadex probably involved the action of a P element located near this locus on the X chromosome of the P strain that was used in the experiments. Mutations in two chromosome regions, one including the zeste-white loci and the other near the miniature locus, were much more frequent in the M × P hybrids than in the M × Q hybrids. These mutations also probably arose from P element insertions. The implication is that insertion mutations occur infrequently in the M × Q hybrids, possibly because most of the P elements they carry are defective. In M × P hybrids, there is variation among loci with respect to P elements mutagenesis, indicating that P elements possess a degree of insertional specificity.
THE EVOLUTION OF MULTIGENE FAMILIES UNDER INTRACHROMOSOMAL GENE CONVERSION
Authors: Nagylaki Thomas 
Published: January 2021

ABSTRACT
A model for the evolution of the probabilities of genetic identity within and between loci of a multigene family in a finite population is formulated and investigated. Unbiased intrachromosomal gene conversion, equal crossing over between tandemly repeated genes, random genetic drift and mutation to new alleles are incorporated. Generations are discrete and nonoverlapping; the diploid, monoecious population mates at random. Formulas for the equilibrium values of the probabilities of identity and a cubic equation for the rate of convergence are deduced. Numerical examples indicate the following. The amount of homology at equilibrium generally decreases as the mutation rate, the population size and the number of repeats increase; it may increase or decrease with increasing crossover rate. The intralocus homology has an intermediate minimum, whereas the interlocus homology increases, as the rate of gene conversion increases. The intralocus homology decreases, whereas the interlocus homology increases, as the proportion of symmetric heteroduplexes increases. The characteristic convergence time can be sufficiently short to imply that intrachromosomal gene conversion may be an important mechanism for maintaining sequence homogeneity among repeated genes. The convergence time decreases as the conversion rate and the proportion of symmetric heteroduplexes increase; although exceptions occur, it generally increases as the population size and the number of repeats increase; it may increase or decrease with increasing crossover rate.
EXPRESSION OF A DNA REPLICATION GENE CLUSTER IN BACTERIOPHAGE T4: GENETIC LINKAGE AND THE CONTROL OF GENE PRODUCT INTERACTIONS
Authors: Gerald W L , Karam J D 
Published: January 2021

ABSTRACT
The results of this study bear on the relationship between genetic linkage and control of interactions between the protein products of different cistrons. In T4 bacteriophage, genes 45 and 44 encode essential components of the phage DNA replication multiprotein complex. T4 gene 45 maps directly upstream of gene 44 relative to the overall direction of reading of this region of the phage chromosome, but it is not known whether these two genes are cotranscribed. It has been shown that a nonsense lesion of T4 gene 45 exerts a cis-dominant inhibitory effect on growth of a missense mutant of gene 44 but not on growth of phage carrying the wild-type gene 44 allele. In previous work, we confirmed these observations on polarity of the gene 45 mutation but detected no polar effects by this lesion on synthesis of either mutant or wild-type gene 44 protein. In the present study, we demonstrate that mRNA for gene 44 protein is separable by gel electrophoresis from gene 45-protein-encoding mRNA. That is, the two proteins are not synthesized from one polycistronic message, and the cis-dominant inhibitory effect of the gene 45 mutation on gene 44 function is probably expressed at a posttranslational stage. We propose that close genetic linkage, whether or not it provides shared transcriptional and translational regulatory signals for certain clusters of functionally related cistrons, may determine the intracellular compartmentalization for synthesis of proteins encoded by these clusters. In prokaryotes, such linkage-dependent compartmentation may minimize the diffusion distances between gene products that are synthesized at low levels and are destined to interact.
FORMATION OF CHROMOSOME REARRANGEMENTS BY P FACTORS IN DROSOPHILA
Authors: Engels William R , Preston Christine R 
Published: January 2021

ABSTRACT
We studied a collection of 746 chromosome rearrangements all induced by the activity of members of the P family of transposable elements in Drosophila melanogaster. The chromosomes ranged from simple inversions to complex rearrangements. The distribution of complex rearrangement classes was of the kind expected if each rearrangement came about from a single multibreak event followed by random rejoining of chromosome segments, as opposed to a series of two-break events. Most breakpoints occurred at or very near (within a few hundred nucleotide pairs) the sites of preexisting P elements, but these elements were often lost during the rearrangement event. There were also a few cases of apparent gain of P elements. In cases in which both breakpoints of an inversion retained P elements, that inversion was capable of reverting at high frequencies to the original sequence or something close to it. This reversion occurred with sufficient precision to restore the function of a gene, held-up-b, which had been mutated by the breakpoint. However, some of the reversions had acquired irregularities at the former breakpoints that were detectable either by standard cytology or by molecular methods. The revertants themselves retained the ability to undergo further rearrangements depending on the presence of P elements. We interpret these results to rule out the simplest hypotheses of rearrangement formation that involve cointegrate structures or homologous recombination. The data provide a general picture of the rearrangement process and its possible relationship to transposition.
FUNCTIONAL INTERCHANGEABILITY OF DNA REPLICATION GENES IN SALMONELLA TYPHIMURIUM AND ESCHERICHIA COLI DEMONSTRATED BY A GENERAL COMPLEMENTATION PROCEDURE
Authors: Maurer Russell , Osmond Barbara C , Shekhtman Eugene , Wong Annette , Botstein David 
Published: January 2021

ABSTRACT
Twenty-four genes from Salmonella typhimurium that affect DNA replication were isolated from a λ-Salmonella genomic library by lysogenic complementation of temperature-sensitive mutants of Salmonella or E. coli, using a new plaque complementation assay. The complementing λ clones, which make red plaques in this assay, and noncomplementing mutant derivatives, which make uncolored plaques, were used to further characterize the temperature-sensitive Salmonella mutants and to establish the functional similarity of E. coli and Salmonella DNA replication genes. For 17 of 18 E. coli mutants representing distinct loci, a Salmonella gene that complemented the mutant was found. This result indicates that single Salmonella replication proteins are able to function in otherwise all E. coli replication complexes and suggests that the detailed properties of Salmonella and E. coli replication proteins are very similar. The other seven Salmonella genes that were cloned were unrelated functionally to any E. coli genes examined. —As an aid to the derivation of chromosomal mutations affecting some of the cloned genes, a general method was developed for placing a transposon in the Salmonella chromosome in a segment corresponding to cloned DNA. Chromosomal mutations were derived in Salmonella affecting a gene (dnaA) that was cloned by complementation of an E. coli mutant by using the transposon-encoded drug resistance as a selectable marker in local mutagenesis.
GENETIC CONTROL OF MEIOSIS IN RICE, ORYZA SATIVA L. III. EFFECT OF DS GENES ON GENETIC RECOMBINATION
Authors: Kitada Kunio , Omura Takeshi 
Published: January 2021

ABSTRACT
The recombination frequency as influenced by five independent recessive ds genes was measured on three segments of different chromosomes of rice, Oryza sativa L. Each ds gene in the homozygous condition resulted in an almost equally reduced recombination frequency in the three segments. When the mean reduction in recombination frequency was related to the reduction of chiasma frequency, the five ds genes were divided into two types: in one type the reduction of chiasma frequency almost corresponded to the mean reduction of recombination frequency, and in the other the chiasma frequency was greatly reduced in comparison with the mean reduction of recombination frequency. Three of the five ds genes were found to belong to the former group. In both types, normal synaptonemal complexes were observed in pachytene cells homozygous for ds genes. This finding suggests that ds genes do not affect the formation of synaptonemal complexes which are regarded as the prerequisite structure for crossing over.
IDENTIFICATION OF NEW GENES INVOLVED IN THE REGULATION OF YEAST ALCOHOL DEHYDROGENASE II
Authors: Denis Clyde L 
Published: January 2021

ABSTRACT
Recessive mutations in two negative control elements, CRE1 and CRE2, have been obtained that allow the glucose-repressible alcohol dehydrogenase (ADHII) of yeast to escape repression by glucose. Both the cre1 and cre2 alleles affected ADHII synthesis irrespective of the allele of the positive effector, ADR1. However, for complete derepression of ADHII synthesis, a wild-type ADR1 gene was required. Neither the cre1 nor cre2 alleles affected the expression of several other glucose-repressible enzymes. A third locus, CCR4, was identified by recessive mutations that suppressed the cre1 and cre2 phenotypes. The ccr4 allele blocked the derepression of ADHII and several other glucose-repressible enzymes, indicating that the CCR4 gene is a positive control element. The ccr4 allele had no effect on the repression of ADHII when it was combined with the ADR1-5 c allele, whereas the phenotypically similar ccr1 allele, which partially suppresses ADR1-5 c, did not suppress the cre1 or cre2 phenotype. Complementation studies also indicated that ccr1 and snf1 are allelic. A model of ADHII regulation is proposed in which both ADR1 and CCR4 are required for ADHII expression. CRE1 and CRE2 negatively control CCR4, whereas CCR1 is required for ADR1 function.
CLONAL ANALYSIS OF DOMINANT FEMALE-STERILE, GERMLINE-DEPENDENT MUTATIONS IN DROSOPHILA MELANOGASTER
Authors: Perrimon Norbert 
Published: January 2021

ABSTRACT
Three allelic, dominant and germline-dependent female-sterile mutations (ovoD mutations) can be classified according to the severity of the ovarian abnormalities that they produce. The size and frequency of +/+ germline clones, induced in ovoD/+ females, were compared with K10/K10 germline clones induced in K10/+ control females. The frequency of germline clones induced by irradiation of first instar larvae is similar for the three dominant alleles and K10; however, the clone size increased with the strength of the allele tested, compared with K10 clones. When clones were induced later in development, the clone frequencies decreased with the strength of the alleles. These results are discussed in the context of the antimorphic nature of these mutations and the characteristics of germline development. The use of these alleles as tools in the genetic analysis of development is discussed.
EPISTATIC INTERACTIONS OF RADIATION-SENSITIVE (rad) MUTANTS OF CAENORHABDITIS ELEGANS
Authors: Hartman Philip S 
Published: January 2021

ABSTRACT
Six double mutants and a quadruple mutant were derived from four UV radiation-hypersensitive single mutants (rad-1, rad-2, rad-3 and rad-7). Sensitivities of the 11 strains to UV, γ-radiation and methyl methanesulfonate (MMS) were compared. Of the six double mutants, only the rad-1;rad-2 and rad-3;rad-7 doubles were no more hypersensitive than the most sensitive single mutant to UV-radiation. Thus, rad-1 and rad-2 define one epistasis group, whereas rad-3 and rad-7 define another. Consistent with this model was the observation that rad-1 and rad-2, but not rad-3 and rad-7, were hypersensitive to γ-radiation. In addition, none of the multiple mutants was more hypersensitive to γ-radiation than the most sensitive single rad mutant. No synergistic interactions of the rad mutations with respect to MMS sensitivities were observed.
MOLECULAR ANALYSIS OF X-RAY-INDUCED ALCOHOL DEHYDROGENASE (Adh) NULL MUTATIONS IN DROSOPHILA MELANOGASTER
Authors: Kelley Mark R , Mims Inka P , Farnet Chris M , Dicharry Sherry A , Lee William R 
Published: January 2021

ABSTRACT
We have attempted to analyze at the molecular level mutants previously determined as having intragenic lesions caused by X-ray mutagenesis. C. S. Aaron isolated 33 null mutations at the Adh locus and in collaboration with other investigators classified 23 as deletions. Of the eight mutants analyzed here, only two produced a detectable ADH protein using the two-dimensional electrophoresis technique. Restriction endonuclease and Southern blot analysis showed that three of the mutants were normal compared to the wild-type restriction pattern, with one of the three producing a mutant ADH protein. Among the five mutants that had altered restriction patterns, only one mutant produced a detectable mutant ADH protein. All the mutants produced a hybridizable mRNA when probed with the genomic clones, suggesting that the mutant phenotype was not due to transcriptional inhibition. Two probable explanations proposed for these observations are (1) mutations may be due to deletions of one or a few bases resulting in frameshifts to nonsense codons and premature termination of ADH peptide synthesis or (2) mutations may be a result of transitions to nonsense codons, again producing shortened ADH proteins. Those mutants producing a mutant polypeptide may have resulted from mutations to missense rather than nonsense codons. The five mutants showing an abnormal endonuclease Southern blot along with the 23 mutants previously shown to be deletions (28/33 or 85%) are associated with multiple DNA chain breaks. Although all of the DNA chain breaks are not necessarily associated with the mutant phenotype of the Adh locus, multiple DNA chain breaks are the most consistent characteristic of ionizing radiation damage to DNA.