bluuebunny/crossref_metadata_2025_split huggingface dataset:
FITNESS AND DENSITY-DEPENDENT POPULATION GROWTH IN DROSOPHILA MELANOGASTER
Authors: Mueller Laurence D , Ayala Francisco J 
Published: April 2021

ABSTRACT
The density-dependent rates of population growth were determined for 26 populations of Drosophila melanogaster maintained in the serial transfer system. Twenty-five populations were homozygous for an entire chromosome 2 sampled from nature; the other was a random heterozygous population. Rates of population growth around the carrying capacity cannot explain the large fitness depression of these lines. However, the homozygous lines show large differences in rates of population growth at low densities relative to the random heterozygous standard. The average relative fitness of the homozygous lines, as determined from the growth rates at the lowest density, is 0.51.
IDENTIFICATION OF A GENETIC ELEMENT THAT CONTROLS THE ORGAN-SPECIFIC EXPRESSION OF Adh1 IN MAIZE
Authors: Woodman James C , Freeling Michael 
Published: April 2021

ABSTRACT
Allozyme balances serve as markers of quantitative behavior of electrophoretically distinguishable alleles. By the use of ADH Set I allozyme balances, it is demonstrated that all Adh1-S/Adh1-F individuals from more than 20 diverse S/F families exhibit a reciprocal correlation between Adh1 quantitative behavior in two maize organs: the scutellum and primary root. Within an electrophoretic mobility class, the Adh1 allele that is relatively underexpressed in the scutellum is relatively overexpressed in the primary root, and vice versa. Segregation tests prove that this "reciprocal effect" is the property of a cis-acting site that is closely linked to or within the Adh1 structural gene, and it is not affected by diverse genetic backgrounds. Immunological and [3H]-leucine incorporation experiments establish that Adh1 quantitative variants differ in ADH1·ADH1 synthetic rates in the anaerobic primary root. The reciprocal-effect phenomenon suggests that the cis-acting loci controlling Adh1 quantitative expression in each respective organ are at least in close proximity, or may share common DNA sequences. We discuss the possibility that the reciprocal-effect locus is a regulatory component of the Adh1 cistron.
THE GENETIC AND CYTOLOGICAL ORGANIZATION OF THE Y CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Kennison James A 
Published: April 2021

ABSTRACT
Cytological and genetic analyses of 121 translocations between the Y chromosome and the centric heterochromatin of the X chromosome have been used to define and localize six regions on the Y chromosome of Drosophila melanogaster necessary for male fertility. These regions are associated with nonfluorescent blocks of the Y chromosome, as revealed using Hoechst 33258 or quinacrine staining. Each region appears to contain but one functional unit, as defined by failure of complementation among translocations with breakpoints within the same block. The distribution of translocation breakpoints examined appears to be nonrandom, in that breaks occur preferentially in the nonfluorescent blocks and not in the large fluorescent blocks.
GENETIC VARIABILITY OF FLIGHT METABOLISM IN DROSOPHILA MELANOGASTER. I. CHARACTERIZATION OF POWER OUTPUT DURING TETHERED FLIGHT
Authors: Curtsinger James W , Laurie-Ahlberg Cathy C 
Published: April 2021

ABSTRACT
The mechanical power imparted to the wings during tethered flight of Drosophila melanogaster is estimated from wing-beat frequency, wing-stroke amplitude and various aspects of wing morphology by applying the steady-state aerodynamics model of insect flight developed by Weis-Fogh (1972, 1973). Wing-beat frequency, the major determinant of power output, is highly correlated with the rate of oxygen consumption. Estimates of power generated during flight should closely reflect rates of ATP production in the flight muscles, since flies do not acquire an oxygen debt or accumulate ATP during flight. In an experiment using 21 chromosome 2 substitution lines, lines were a significant source of variation for all flight parameters measured. Broadsense heritabilities ranged from 0.16 for wing-stroke amplitude to 0.44 for inertial power. The variation among lines is not explained by variation in total body size (i.e., live weight). Line differences in flight parameters are robust with respect to age, ambient temperature and duration of flight. These results indicate that characterization of the power output during tethered flight will provide a sensitive experimental system for detecting the physiological effects of variation in the structure or quantity of the enzymes involved in flight metabolism.
A MODEL OF EVOLUTIONARY BASE SUBSTITUTIONS AND ITS APPLICATION WITH SPECIAL REFERENCE TO RAPID CHANGE OF PSEUDOGENES
Authors: Takahata Naoyuki , Kimura Motoo 
Published: April 2021

ABSTRACT
A model of evolutionary base substitutions that can incorporate different substitutional rates between the four bases and that takes into account unequal composition of bases in DNA sequences is proposed. Using this model, we derived formulae that enable us to estimate the evolutionary distances in terms of the number of nucleotide substitutions through comparative studies of nucleotide sequences. In order to check the validity of various formulae, Monte Carlo experiments were performed. These formulae were applied to analyze data on DNA sequences from diverse organisms. Particular attention was paid to problems concerning a globin pseudogene in the mouse and the time of its origin through duplication. We obtained a result suggesting that the evolutionary rates of substitution in the first and second codon positions of the pseudogene were roughly 10 times faster than those in the normal globin genes; whereas, the rate in the third position remained almost unchanged. Application of our formulae to histone genes H2B and H3 of the sea urchin showed that, in each of these genes, the rate in the third codon position is tremendously higher than that in the second position. All of these observations can easily and consistently be interpreted by the neutral theory of molecular evolution.
MUTATIONAL SPECIFICITY OF ULTRAVIOLET LIGHT IN ESCHERICHIA COLI WITH AND WITHOUT THE R PLASMID pKM101
Authors: Fowler R G , McGinty L , Mortelmans K E 
Published: April 2021

ABSTRACT
Plasmid pKM101 provides UV protection and increases the frequency of spontaneous and UV-induced mutations in Escherichia coli. By analyzing reversion patterns of defined trpA alleles, we showed that pKM101 altered the mutational specificity of UV-induced mutations. Certain UV-induced base-pair substitutions were strongly enhanced, while others were decreased in frequency in the presence of pKM101. This result suggests an interaction between cellular misrepair and an error-prone repair function(s) provided by pKM101. We have also examined UV mutational specificity in the absence of pKM101 and found the following: (1) UV preferentially enhances missense, as well as nonsense, intergenic suppressor mutations; (2) UV causes all possible base-pair substitutions as well as frameshift mutations; (3) G·C base pairs are more susceptible to UV mutagenesis than A·T base pairs at the same nucleotide positions; and (4) UV-induced mutations can occur at nucleotide positions that are not part of pyrimidine-pyrimidine sequences.
LINKAGE OF MUTATIONS AFFECTING MINUS FLAGELLAR MEMBRANE AGGLUTINABILITY TO THE mt
- MATING-TYPE LOCUS OF CHLAMYDOMONAS
Authors: Hwang Carol J , Monk Brian C , Goodenough Ursula W 
Published: April 2021

ABSTRACT
Two independently isolated mutant strains, imp-10 and imp-12, were obtained by UV irradiation of wild-type mating-type minus (wt-). Each fails to agglutinate sexually with gametes of either mating type, but mating and zygote formation can be elicited by agglutinating either strain to wt+ gametes by means of anti-flagellar antiserum. Tetrad analysis of the resultant zygotes shows that both imp-10 and imp-12 are very closely linked to mt -, with no recombinants observed. Diploid strains constructed between imp-10 or imp-12 and wt+ gametes are wt-, that is, they agglutinate and fuse like normal minus cells. Tetrad analysis of triploids from imp-10 diploid x wt+ haploid crosses shows that only imp-10 and wt+ products are recovered. A model is proposed to account for these results.
PARASEXUAL GENETIC ANALYSIS OF CELL PROPORTIONING MUTANTS OF DICTYOSTELIUM DISCOIDEUM
Authors: Morrissey James H , Loomis William F 
Published: April 2021

ABSTRACT
Eight independently isolated mutants of Dictyostelium discoideum that differentiate exclusively into stalk cells make up one complementation group and carry single recessive mutations at the stalky locus, stkA, located on linkage group II. KY19, a previously described strain that differentiates into spores, but not stalk cells, was found to possess a recessive mutation defining the stalkless locus, stlA, located on linkage group VI. An analysis of the properties of these mutants, together with the phenotype of a haploid double mutant carrying stkA and stlA indicates that stlA results in poorly organized stalk tubes and incomplete stalk cell differentiation, while stkA causes all of the cells to differentiate into stalk cells, even when not enclosed in the stalk tube. The significance of these results is discussed in relation to current theories of pattern formation in D. discoideum.
EVIDENCE THAT TWO LOCI PREDOMINANTLY DETERMINE THE DIFFERENCE IN SUSCEPTIBILITY TO THE HIGH PRESSURE NEUROLOGIC SYNDROME TYPE I SEIZURE IN MICE
Authors: McCall R D , Frierson D 
Published: April 2021

ABSTRACT
Most mammals tested, when exposed to increasing pressure in helium/oxygen atmospheres, exhibit progressive motor disturbances culminating in two, usually successive, well-differentiated convulsive seizures. The seizures are highly reproducible components of the constellation of events that collectively constitute the High Pressure Neurologic Syndrome (HPNS). In the present study, we present evidence that the mean difference in seizure threshold pressures of the first seizure to occur (HPNS Type I) between inbred mouse strains DBA/2J and C57BL/6J is predominantly determined (&gt; 60%) by the expression of a major locus—possibly linked to the H-2 locus on chromosome 17—and a minor locus, probably unlinked. This outcome is derived from applications of the maximum likelihood modeling procedure of Elston and Stewart (1973) and Stewart and Elston (1973) to eleven models of genetic determinacy and tests (including breeding tests) of "preferred" models so derived using BXD recombinant inbred strains that show the following: The major locus exhibits conditional dominance characteristics depending upon compression rate and minor locus genotype. At a constant mean compression rate of 100 atm hr-1, the major locus manifests strong, though incomplete, dominance apparently independent of minor locus genotype. Its expression is, however, highly sensitive to compression rate, losing its dominance altogether at a linear rate of 1,000 atm hr-1. The major locus interacts with the weakly dominant and relatively compression-rate-insensitive minor locus to retain dominance at fast compression only when the dominant alleles of both loci are present. A principal finding of this study is that employing two compression rates permits fuller genetic characterization of murine high-pressure seizure susceptibility differences than could be achieved by use of a single compression rate.
DYNAMICS OF THE LINKAGE DISEQUILIBRIUM FUNCTION UNDER MODELS OF GENE-FREQUENCY HITCHHIKING
Authors: Asmussen Marjorie A , Clegg Michael T 
Published: April 2021

ABSTRACT
The dynamic behavior of the linkage disequilibrium (D) between a neutral and a selected locus is analyzed for a variety of deterministic selection models. The time-dependent behavior of D is governed by the gene frequency at the selected locus (p) and by the selection (s) and recombination (r) parameters. Thomson (1977) showed numerically that D may increase under certain initial conditions. We give exact conditions for D to increase in time, which require that the selection intensity exceed the recombination fraction (s &gt; r) and that p be near zero or one. We conclude from this result that gene frequency hitchhiking is most likely to be important when a new favorable mutant enters a population. We also show that, for what can be a wide range of gene frequencies, D will decay at a faster rate than the neutral rate. Consequently, the hitchhiking effect may quickly diminish as the selected gene becomes more common.—The method of analysis allows a complete qualitative description of the dynamics of D as a function of s and r. Two major findings concern the range of gene frequencies at the selected locus for which D either increases over time or decays at a faster rate than under neutrality. For all models considered, the region where D increases (i) first enlarges then shrinks as selection intensifies, and (ii) steadily shrinks as r increases. In contrast, the region of accelerated decay constantly enlarges as the selection intensity increases. This region will either shrink or enlarge as r increases, depending upon the form of selection in force.
MUTATION AT THE am LOCUS OF NEUROSPORA CRASSA
Authors: Kinsey John A , Hung Bao-Shin T 
Published: April 2021

ABSTRACT
Forty-eight new mutations at the am locus of Neurospora crassa have been characterized. Nineteen mutations were induced by UV; of these, eight were missense, two were frameshifts, two were nonsense, three were deletions and four were unidentified. Twenty-nine mutations were induced with nitrous acid; of these, twenty-one were missense, three were frameshifts, one was nonsense, two were deletions and one was genetically unstable.
THE GENETIC ANALYSIS OF A RECIPROCAL TRANSLOCATION, eT1(III; V), IN CAENORHABDITIS ELEGANS
Authors: Rosenbluth Raja E , Baillie David L 
Published: April 2021

ABSTRACT
The Caenorhabditis elegans mutation e873, which results in a recessive uncoordinated phenotype (formerly named Unc-72) and which had been isolated after 32P t reatment (BRENNER1 974), has now been found to act as a crossover suppressor and to be associated with a translocation between linkage groups (LG's) IIIand V. The translocation has been named, eTl(ZI1; V); eT1acts as a dominant crossover suppressor for both the right half of LGIIIand the left half of LGV,providing a balancer for a total of 39 map units. The uncoordinated e873phenotype has been shown to be a consequence of Eminactive unr- 36111gene. It was possible to demonstrate that, in translocation heterozygotes, eT1chromosomes marked with either sma-3or dpy-11segregate from normal LGIII,while those marked with bli-5, sm-2or unc-42segregate from normal LGV.Since bli-5and sma-2are normally on LGIII,and dpy-11is normally on LGV,it is concluded that: (a) eT1is a reciprocal translocation; (b) there is a breakpoint between sma-3and sma-2in LGIII(the region containing unc- 36)and one between dpy-11and unc-42in LGV;(c) thera is no dominant centromere between sma-2and bli-5on LGIII,since in eT1these genes are not linked to a LGIIIcentromere. Similarly, it is highly unlikely that there is a centromere to the left of dpy-11on LGV.The new gene order in eT1was determined by measuring recombination rates between markers in eT1homozygotes. It is concluded that the new order is: dpy-1 sma-3 (break) dpy-11 unc-60,and bli-5 sma-2 (break) unc-42 unc-51.——Thisis the first analysis of a C. eleganstranslocation with respect to reciprocity, breakpoints and new gene order.
Mortality, Falls, and Fracture Risk Are Positively Associated With Frailty: A SIDIAP Cohort Study of 890 000 Patients
Authors: Middleton Robert , Poveda Jose Luis , Orfila Pernas Francesc , Martinez Laguna Daniel , Diez Perez Adolfo , Nogués Xavier , Carbonell Abella Cristina , Reyes Carlen , Prieto-Alhambra Daniel 
Published: April 2021

Abstract

Background
Frail subjects are at increased risk of adverse outcomes. We aimed to assess their risk of falls, all-cause mortality, and fractures.

Method
We used a retrospective cohort study using the Sistema d’Informació per al Desenvolupament de l’Investigació en Atenció Primària database (&gt;6 million residents). Subjects aged 75 years and older with ≥1 year of valid data (2007–2015) were included. Follow-up was carried out from (the latest of) the date of cohort entry up to migration, end of the study period or outcome (whichever came first). The eFRAGICAP classified subjects as fit, mild, moderate, or severely frail. Outcomes (10th revision of the International Classification of Diseases) were incident falls, fractures (overall/hip/vertebral), and all-cause mortality during the study period. Statistics: hazard ratios (HRs), 95% CI adjusted (per age, sex, and socioeconomic status), and unadjusted cause-specific Cox models, accounting for competing risk of death (fit group as the reference).

Results
A total of 893 211 subjects were analyzed; 54.4% were classified as fit, 34.0% as mild, 9.9% as moderate, and 1.6% as severely frail. Compared with the fit, frail had an increased risk of falls (adjusted HR [95% CI] of 1.55 [1.52–1.58], 2.74 [2.66–2.84], and 5.94 [5.52–6.40]), all-cause mortality (adjusted HR [95% CI] of 1.36 [1.35–1.37], 2.19 [2.16–2.23], and 4.29 [4.13–4.45]), and fractures (adjusted HR [95% CI] of 1.21 [1.20–1.23], 1.51 [1.47–1.55], and 2.36 [2.20–2.53]) for mild, moderate, and severe frailty, respectively. Severely frail had a high risk of vertebral (HR of 2.49 [1.99–3.11]) and hip fracture (HR [95% CI] of 1.85 [1.50–2.28]). Accounting for competing risk of death did not change results.

Conclusion
Frail subjects are at increased risk of death, fractures, and falls. The eFRAGICAP tool can easily assess frailty in electronic primary care databases in Spain.
Regional tongue deformations during chewing and drinking in the pig
Authors: Olson Rachel A , Montuelle Stéphane J , Curtis Hannah , Williams Susan H 
Published: April 2021

Abstract
As a muscular hydrostat, the tongue undergoes complex deformations during most oral behaviors, including chewing and drinking. During these behaviors, deformations occur in concert with tongue and jaw movements to position and transport the bolus. Moreover, the various parts of the tongue may move and deform at similar timepoints relative to the gape cycle or they may occur at different timepoints, indicating regional biomechanical and functional variation. The goal of this study is to quantify tongue biomechanics during chewing and drinking in pigs by characterizing intrinsic deformations of the tongue across multiple regions simultaneously. Tongue deformations are generally larger during chewing cycles compared to drinking cycles. Chewing and drinking also differ in the timing of regional length and width, but not total length, deformations. This demonstrates functional differences in the temporal dynamics of localized shape changes whereas the global properties of jaw-tongue coordination are maintained. Finally, differences in the trade-off between length and width deformations demonstrate that the properties of a muscular hydrostat are observed at the whole tongue level, but biomechanical variation (e.g., changes in movements and deformations) at the regional level exists. This study provides new critical insights into the regional contributions to tongue deformations as a basis for future work on multidimensional shape changes in soft tissues.
Ecomorphometric Analysis of Diversity in Cranial Shape of Pygopodid Geckos
Authors: Gurgis George P , Daza Juan D , Brennan Ian G , Hutchinson Mark , Bauer Aaron M , Stocker Michelle R , Olori Jennifer C 
Published: April 2021

SynopsisPygopodids are elongate, functionally limbless geckos found throughout Australia. The clade presents low taxonomic diversity (∼45 spp.), but a variety of cranial morphologies, habitat use, and locomotor abilities that vary between and within genera. In order to assess potential relationships between cranial morphology and ecology, computed tomography scans of 29 species were used for 3D geometric morphometric analysis. A combination of 24 static landmarks and 20 sliding semi-landmarks were subjected to Generalized Procrustes Alignment. Disparity in cranial shape was visualized through Principal Component Analysis, and a multivariate analysis of variance (MANOVA) was used to test for an association between shape, habitat, and diet. A subset of 27 species with well-resolved phylogenetic relationships was used to generate a phylomorphospace and conduct phylogeny-corrected MANOVA. Similar analyses were done solely on Aprasia taxa to explore species-level variation. Most of the variation across pygopodids was described by principal component (PC) 1(54%: cranial roof width, parabasisphenoid, and occipital length), PC2 (12%: snout elongation and braincase width), and PC3 (6%: elongation and shape of the palate and rostrum). Without phylogenetic correction, both habitat and diet were significant influencers of variation in cranial morphology. However, in the phylogeny-corrected MANOVA, habitat remained weakly significant, but not diet, which can be explained by generic-level differences in ecology rather than among species. Our results demonstrate that at higher levels, phylogeny has a strong effect on morphology, but that influence may be due to small sample size when comparing genera. However, because some closely related taxa occupy distant regions of morphospace, diverging diets, and use of fossorial habitats may contribute to variation seen in these geckos.
Retrospective Evaluation of the Accuracy of Five Different Severity Scores To Predict the Mortality in Burn Patients
Authors: de Carvalho Viviane Fernandes , Paggiaro André Oliveira , Goldner Alexandre , Gemperli Rolf 
Published: April 2021

Abstract
Patients with great clinical impairment, due to extensive burns, need to be admitted to intensive care units, in these treatment sites, indices are used to classify the severity of patients. The aim of this study was to compare the accuracy of the FLAMES score in relation to the Acute Physiologic and Chronic Health Evaluation II (APACHE II), the Simplified Acute Physiologic Score II (SAPS II), the Logistic Organ Dysfunction System (LODS), and the Abbreviated Burn Severity Index (ABSI) applied to the severe burn patient facing mortality in an ICU of a reference center for burns in Brazil. A retrospective study conducted in ICU comparing the accuracy the APACHE II, SAPS II, LODS, ABSI, and FLAMES instruments were applied to all the selected medical records. In order to assess the accuracy of the severity scores of the instruments (SIs) chosen for this study, the area under the receiver operating characteristic (ROC) curve was used. Among the 574 patients included in the study, male individuals (70.13%), with an average age of 44.01 ± 28.64 prevailed and the majority of the burns were caused by accidents (76.53%). The outcome accounted for 35.29% of deaths. It was observed that the FLAMES and ABSI presented the two largest areas under the ROC curves and the highest sensitivities (96% and 89%, respectively). The APACHE II, SAPS II, and LODS presented sensitivities equal to or greater than 80%. It has been demonstrated that indices specifically developed for burn patients, specifically the FLAMES and ABSI indices, presented better accuracies and prediction performances.