bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acting rapidly to deploy readily available methane mitigation measures by sector can immediately slow global warming
Authors: Ocko Ilissa B , Sun Tianyi , Shindell Drew , Oppenheimer Michael , Hristov Alexander N , Pacala Stephen W , Mauzerall Denise L , Xu Yangyang , Hamburg Steven P 
Published: April 2021

Abstract
Methane mitigation is essential for addressing climate change, but the value of rapidly implementing available mitigation measures is not well understood. In this paper, we analyze the climate benefits of fast action to reduce methane emissions as compared to slower and delayed mitigation timelines. We find that the scale up and deployment of greatly underutilized but available mitigation measures will have significant near-term temperature benefits beyond that from slow or delayed action. Overall, strategies exist to cut global methane emissions from human activities in half within the next ten years and half of these strategies currently incur no net cost. Pursuing all mitigation measures now could slow the global-mean rate of near-term decadal warming by around 30%, avoid a quarter of a degree centigrade of additional global-mean warming by midcentury, and set ourselves on a path to avoid more than half a degree centigrade by end of century. On the other hand, slow implementation of these measures may result in an additional tenth of a degree of global-mean warming by midcentury and 5% faster warming rate (relative to fast action), and waiting to pursue these measures until midcentury may result in an additional two tenths of a degree centigrade by midcentury and 15% faster warming rate (relative to fast action). Slow or delayed methane action is viewed by many as reasonable given that current and on-the-horizon climate policies heavily emphasize actions that benefit the climate in the long-term, such as decarbonization and reaching net-zero emissions, whereas methane emitted over the next couple of decades will play a limited role in long-term warming. However, given that fast methane action can considerably limit climate damages in the near-term, it is urgent to scale up efforts and take advantage of this achievable and affordable opportunity as we simultaneously reduce carbon dioxide emissions.
Utilizing rainy season onset predictions to enhance maize yields in Ethiopia
Authors: Lala Jonathan , Yang Meijian , Wang Guiling , Block Paul 
Published: April 2021

Abstract
For countries dependent on rainfed agriculture, failure of the rainy season can lead to serious consequences on the broader economy. Maize, a common staple crop in these countries, often expresses significant interannual variability, given its high sensitivity to water stress. It is traditionally planted at rainy season onset to maximize the growing season and potential yield; however, this risks planting during a ‘false onset’ that can damage the crop or require replanting. Rainy season onset forecasts offer some promise in reducing this risk; however, the potential for increasing yield has not been explicitly quantified. This study quantifies the yield gap associated with suboptimal maize planting times using a process-based crop model over a 36 year historical period across Ethiopia. Onset-informed and forecast-informed approaches are compared with a baseline approach, and results indicate a strong potential for yield gains in drier regions as well as reductions in interannual variance countrywide. In contrast, regions with reliably sufficient precipitation illustrate only minimal gains. In general, integration of onset forecasts into agricultural decision-making warrants inclusion in agricultural extension efforts.
Classification of Land Cover in Kumamoto Area, Japan to Evaluate Infiltration and Surface Runoff
Authors: Amano H , Iwasaki Y , Ichikawa T 
Published: April 2021

Abstract
Almost 100% of domestic water is covered by groundwater in the Kumamoto region, Japan. However, in recent years, the groundwater recharge area (particularly paddy fields) has been significantly decreasing, and the groundwater level has been gradually dropping in some places. Aside from this, the groundwater level was abnormally changed as an impact of the 2016 Kumamoto earthquake. Our final goal is to build a model to represent the groundwater level change including the abnormal change. For this purpose, we generated a land cover map by using temporal Normalized Difference Vegetation Index (NDVI) changes based on Landsat-8 satellite images and Geographic Information System (GIS) data. Our classification results well expressed the actual land cover especially around rivers, lakes and buildings compared with the existing land cover map. The calculated infiltration and surface runoff amounts from grasslands with the different land uses indicated the importance of understanding not only land covers but also land uses to evaluate infiltration and surface runoff amounts.
Load distribution to contact area analysis of Gecko’s limb and feet
Authors: Tjandra K , Putra R , Sriwijaya R 
Published: April 2021

Abstract
Gecko possesses a distinct feature that enables it to move in lateral and vertical directions due to its adhesive foot structures. In the past few years, the research on Gecko is primarily focused on this adhesive feature. However, Gecko’s hind attachment relies heavily on the available contact area between its foot and its attaching medium. In this paper, physical observation and finite element analysis were performed to identify the load distribution pattern and contact area of Gecko’s hind. Further investigations were also performed to understand the force in each digit of Gecko’s feet. This research will provide readers with a more holistic understanding and complement previous research on Gecko’s attachment system.
Alignment dynamics of single-wall carbon nanotubes under electric field in different surfactant solutions
Authors: Rahman Atiqur , Zubair Ahmed 
Published: April 2021

Abstract
The dynamics of metallic single-wall carbon nanotube (SWCNT) alignment inside various viscous media under electric field is investigated in this simulation work for the manifestation of macroscale aligned SWCNT films. An alternating current (AC) electric field was applied to the liquid solution of several surfactants (DIW, DMF, CHEX, SDS, and DOC) containing SWCNTs. The time required for the SWCNTs to get aligned to the applied AC electric field was simulated for different initial conditions for all the surfactants. An analytical model based on dielectrophoresis induced torque was employed. The model considers the viscosity and conductivity of the surrounding medium. The influence of SWCNT length, SWCNT radius, and frequency of the AC field on the assembly of SWCNTs were studied. Our analysis showed that a longer and narrower SWCNT prompts faster assembly to an aligned SWCNT aggregation. Furthermore, the effect of the concentration of SDS and the effect of electric field strength for DIW surfactant were also investigated. Viscosity plays a significant role in the alignment process. Slower SWCNT alignment is caused by a medium of higher viscosity.
Design of metal hydride reactor with embedded helical coil using optimization methods
Authors: Tiwari Saurabh , Sharma Pratibha 
Published: April 2021

Abstract
Metal hydride offers an efficient and cost-effective method to store hydrogen. In this study, Taguchi method coupled with grey relational analysis was used to optimize the design parameters i.e., diameter of helical tube (dh), major diameter of helical tube (dm), number of turns of helical tube (N) and velocity of heat transfer fluid (
V

f

) for the helical tube heat exchanger embedded inside metal hydride bed to achieve minimum desorption time (td) for 80% desorption and minimum outlet temperature (T0) of heat transfer fluid (HTF). The performance of all experiments in the orthogonal array used for Taguchi and Grey relational analysis was evaluated by 3-D numerical simulations performed in commercial software COMSOL 5.3a. This stepwise methodology is significantly computationally efficient as the number of required simulations reduced by 90% as compared to the traditional parametric study-based methodology. Further, this methodology enables to estimate an optimized level of the parameters by considering all the objective functions (td, T0) simultaneously. Later, the performance of the optimally designed systems was compared with the orthogonal array experiments and it was found out that the optimized system designs have better performance in terms of the objective parameters i.e., td and T0 when compared with the other experiments of orthogonal array. These optimized systems will then be used for refrigeration and cooling applications.
SISTER CHROMATID EXCHANGE IN XERODERMA PIGMENTOSUM CELLS THAT ARE DEFECTIVE IN DNA EXCISION REPAIR OR POST-REPLICATION REPAIR
Authors: Wolff Sheldon , Bodycote Judy , Thomas G H , Cleaver James E 
Published: April 2021

ABSTRACT
The formation of sister chromatid exchanges has been postulated to depend upon the action of DNA repair enzymes. Our experiments with various human cell lines show that the yield of sister chromatid exchanges is within normal limits in both excision-repair-defective and post-replication-repair-defective cells from the autosomal recessive disease, xeroderma pigmentosum. These results indicate that hypotheses invoking known DNA repair processes to account for the recombination of sister chromatids are inadequate and that the exact enzymatic processes are as yet unknown.
GENETIC DAMAGE AT SPECIFIC GENE LOCI IN DROSOPHILA WITH BETATRON X-RAYS
Authors: Alexander Mary L 
Published: April 2021

ABSTRACT
The mutation rate was determined for mature sperm at eight specific gene loci on the third chromosome of Drosophila melanogaster using the low ion density radiations of 22 Mev betatron X-rays. A dose of 3000 rads of betatron X-rays produced a mutation rate of 4.36 × 10-8 per rad/locus. Among the mutations observed, 66% were recessive lethals and 34% viable when homozygous. Only one of the 24 viable mutations was associated with a chromosome aberration. Among the 47 recessive lethals, no two-break aberrations were detected in 48.9% of the lethals, deletions were associated with 42.2%, inversions with 6.7% and translocations with 2.2%.—When these genetic results are compared to those for 250 KV X-rays, the mutation rate for betatron treatments was slightly lower (.76), the recessive lethal rate among induced mutations was higher, and the chromosome aberrations among lethal mutations were slightly lower than with 250 KV X-rays. Although the two types of irradiations differ by an ion density of approximately ten, the amount and types of inheritable genetic damage induced by the two radiations in mature sperm were not significantly different.
LIPID DEFICIENCIES, LEUKOCYTOSIS, BRITTLE SKIN—A LETHAL SYNDROME CAUSED BY A RECESSIVE MUTATION, EDEMATOUS (OED), IN THE MOUSE
Authors: Schiffman Michael B , Santorineou Maria L , Lewis Susan E , Turchin Howard A , Gluecksohn-Waelsch Salome 
Published: April 2021

ABSTRACT
A new neonatal lethal mutation in the mouse with pleiotropic effects, edematous (oed), arose spontaneously in the phocomelic strain and has been shown to have an autosomal recessive mode of inheritance. The external phenotypic characteristics include a generally bloated appearance, shiny cellophane-like skin, and distal hematomata of the extremities. Internally, no gross or histological abnormalities could be identified, with the exception of a striking leukocytosis. Biochemical analysis revealed a severe disturbance of lipid metabolism. Deficiencies in the VLDL, LDL, and the HDL lipoprotein fractions have been found in the mutant plasma. In addition, all serum lipids are markedly decreased. However, in the mutant liver, only triglycerides are significantly decreased; total liver cholesterol and phospholipid values are within normal limits. The primary biochemical defect as well as the causal relationship between the striking abnormalities of lipid metabolism and those of skin and blood are unknown at this time.
POPULATION GENETICS OF EUPHYDRYAS BUTTERFLIES. I. GENETIC VARIATION AND THE NEUTRALITY HYPOTHESIS
Authors: McKechnie Stephen W , Ehrlich Paul R , White Raymond R 
Published: April 2021

ABSTRACT
Twenty-one populations of the checkerspot butterfly, Euphydryas editha, and ten populations of Euphydryas chalcedona were sampled for genetic variation at eight polymorphic enzyme loci. Both species possessed loci that were highly variable from population to population and loci that were virtually identical across all populations sampled. Our data indicate that the neutrality hypothesis is untenable for the loci studied, and therefore selection is indicated as the major factor responsible for producing these patterns. Thorough ecological work allowed gene flow to be ruled out (in almost all instances) as a factor maintaining similar gene frequencies across populations. The Lewontin-Krakauer test indicated magnitudes of heterogeneity among standardized variances of gene frequencies inconsistent with the neutrality hypothesis. The question of whether or not to correct this statistic for sample size is discussed. Observed equitability of gene frequencies of multiple allelic loci was found to be greater than that predicted under the neutrality hypothesis. Genetic differentiation presisting through two generations was found between the one pair of populations known to exchange significant numbers of individuals per generation. Two matrices of genetic distance between populations, based on the eight loci sampled, were found to be significantly correlated with a matrix of environmental distance, based on measures of fourteen environmental parameters. Correlations between gene frequencies and environmental parameters, results of multiple regression analysis, and results of principle component analysis showed strong patterns of association and of "explained" variation. The correlation analyses suggest which factors might be further investigated as proximate selective agents.
COLD-SENSITIVE MUTANTS OF DROSOPHILA MELANOGASTER DEFECTIVE IN RIBOSOME ASSEMBLY
Authors: Falke Ernest V , Wright Theodore R F 
Published: April 2021

ABSTRACT
Thirteen X-linked, cold-sensitive lethal, female-sterile mutants of Drosophila melanogaster located at eight separate loci were screened for their ability to assemble ribosomes at the restrictive temperature of 17°. Females were labelled with 3H-uridine for either 2 or 20 hours at 17°. A mitochondria-free extract was prepared and analyzed by means of sucrose gradient centrifugation. Four of the mutants, l(1)TW-2 cs, l(1)HM16cs, l(1)HM23cs, and l(1)HM20cs, had a lower ratio of cpm in the 40S subunit to cpm in the 60S subunit (40S:60S ratio) than wild type with a 2-hour label. The same was true of a 20-hour label of l(1)TW-2cs, l(1)HM16cs, and l(1)HM23cs, which are allelic, resulted in a 40S:60S ratio higher than wild type. Four other cs mutants were found to have less drastic effects on ribosome assembly. The ribosomal subunits of mutants l(1)HM16sc and l(1)HM20cs sediment at the same rate as their wild-type counterparts. The same is true for the RNA in their ribosomal particles. Sucrose gradient analysis of ribosomes from cold-sensitive lethal, female-sterile mutants appears to be an effective method for finding mutants that affect ribosome assembly.
GENE FREQUENCY DISTRIBUTIONS AS A TEST OF SELECTIVE NEUTRALITY
Authors: Robertson Alan 
Published: April 2021

ABSTRACT
The analysis of differences between loci in the variance of gene frequency over populations within a species has been suggested as a method of detecting natural selection. It is shown that, in the absence of selection, the expected variation over loci depends strongly on the pattern of relationships between populations. The effect of structure within a species is always to increase the variation and therefore to reduce the power of the method.
ON INVERTED REPEAT SEQUENCES IN CHROMOSOMAL DNA
Authors: Wallace Bruce , Kass Thomas L 
Published: April 2021

ABSTRACT
It is suggested that chromosomal DNA should contain a class of palindromic reverse repeats, comparable in number to that of genes themselves, which are formed as follows: (1) a transcription-termination signal that follows the gene plus (on the complementary strand and located as near to the "anti-gene" as possible); (2) a second termination signal which actively prevents the accidental transcription of the anti-gene. Thus, the adjacent termination-anti-termination region of one strand would complement the anti-termination-termination region of the other.
CLUSTERING OF SPECIFIC CROSSOVERS IN MAIZE MICROSPOROCYTES
Authors: Maguire Marjorie P 
Published: April 2021

ABSTRACT
Analysis of systematic scan data from microsporocyte smear preparations suggests that cells with a crossover in a specific region tend to be geographically clustered to some extent within anthers. Crossover classes observed include single crossovers within a heterozygous inversion, three-strand double crossovers within and proximal to the inversion, and four-strand double crossovers within the inversion. Evidence for clustering within scans of cells of the first two classes is reported, but results are inconclusive for the third class. No evidence for within-scan correlation of frequencies of any two of the crossover classes was found. It is inferred that a large part of the variability in crossover frequency observed is probably due to factors which alter crossover interference. Implications related to the frequency and distribution of crossover sites are discussed.
VARIATIONS IN THE NUMBER OF THE Y CHROMOSOMAL rRNA GENES IN DROSOPHILA HYDEI
Authors: Kunz W 
Published: April 2021

ABSTRACT
The number of rRNA cistrons is measured by filter saturation hybridization in different stocks of D. hydei, where the wild-type X chromosome has one nucleolus organizer (NO) and the wild-type Y has two separated NO's. (see PDF) females having no X chromosomal NO show an rDNA content exceeding that of a Y chromosome. An even greater increase in the rRNA cistron number is measured in two translocation stocks where the (see PDF) is combined with one half of a Y and, therefore, each stock contains only one of the two Y chromosomal NO's. But when the same Y fragments are brought together with a wild-type X chromosome they lose about one-half of their rRNA cistrons within one generation. Males with two complementary Y fragments but having no X chromosomal NO show a considerably higher rDNA content than the (see PDF) females, although both are equal in respect of their NO number. Consideration is given to related phenomena in Drosophila melanogaster.
THE GENETIC VARIABILITY OF THIRD CHROMOSOMES IN A LOCAL POPULATION OF DROSOPHILA MELANOGASTER
Authors: Watanabe Takao K , Yamaguchi Osamu , Mukai Terumi 
Published: April 2021

ABSTRACT
Five hundred and two third chromosomes were extracted from a large cage population of Drosophila melanogaster initiated two months after collection of the progenitors near Raleigh, North Carolina in 1970.—Salivary gland chromosomes of 489 chromosome lines were examined and 54 chromosomes were found to carry inversions. The inversions were classified into three polymorphic types [In(3L)P, In(3R)P, and In(3R)C] and two unique types. The polymorphic inversions were found in frequencies of 0.012, 0.088, and 0.010, respectively.—Viabilities of homozygotes and heterozygotes were examined. Chromosomes with lethals occurred with a frequency of 0.495: 0.537 in the group of inversion-carrying chromosomes and 0.490 in the group of inversion-free chromosomes. The average homozygote viability computed on the basis of an average heterozygote viability of 1.0000 was 0.3235 if lethal lines were included and 0.6290 if they were excluded. The detrimental load to lethal load ratio (D:L ratio) was 0.70 (=0.4636-0.6650). The average viability of lethal heterozygotes was significantly larger than that of lethal-free heterozygotes. It appears, however, that lethal genes in heterozygotes have deleterious effects on fitness as a whole.—The average degree of dominance for viability polygenes was estimated to be about 0.3-0.4 in lethal-free individuals and nearly zero in lethal heterozygotes. Overdominance or some form of balancing selection was suggested at some loci. The difference between the values obtained for average degree of dominance due to genetic backgrounds and superior vibaility of lethal heterozygotes (but not fitness as a whole) suggests that some epistasis or coadaptation occurs.—The results described above are similar to those obtained for the second chromosomes (Mukai and Yamaguchi 1974).
COMPLEMENTATION ANALYSIS OF LINKED CIRCADIAN CLOCK MUTANTS OF NEUROSPORA CRASSA
Authors: Feldman Jerry F , Hoyle Marian N 
Published: April 2021

ABSTRACT
A fourth mutant of Neurospora crassa, designated frq-4, has been isolated in which the period length of the circadian conidiation rhythm is shortened to 19.3 ± 0.3 hours. This mutant is tightly linked to the three previously isolated frq mutants, and all four map to the right arm of linkage group VII about 10 map units from the centromere. Complementation tests suggest, but do not prove, that all four mutations are allelic, since each of the four mutants is co-dominant with the frq + allele—i.e., heterokaryons have period lengths intermediate between the mutant and wild-type—and since heterokaryons between pairs of mutants also have period lengths intermediate between those of the two mutants.
INHIBITION OF GROWTH BY AMBER SUPPRESSORS IN YEAST
Authors: Liebman Susan W , Sherman Fred 
Published: April 2021

ABSTRACT
Strains of the yeast Saccharomyces cerevisiae that contain highly efficient amber (UAG) suppressors grow poorly on nutrient medium, while normal or nearly normal growth rates are observed when these strains lose the suppressors or when the suppressors are mutated to lower efficiencies. The different growth rates account for the accumulation of mutants with lowered efficiencies in cultures of strains with highly efficient amber suppressors. Genetic analyses indicate that one of the mutations with a lowered efficiency of suppression is caused by an intragenic mutation of the amber suppressor. The inhibition of growth caused by excessive suppression is expected to be exacerbated when appropriate suppressors are combined together in haploid cells if two suppressors act with a greater efficiency than a single suppressor. Such retardation of growth is observed with combinations of two UAA (ochre) suppressors (Gilmore 1967) and with combinations of two UAG suppressors when the efficiencies of each of the suppressors are within a critical range. In contrast, combinations of a UAA suppressor and a UAG suppressor do not affect growth rate. Apparently while either excessive UAA or excessive UAG suppression is deleterious to yeast, a moderate level of simultaneous UAA and UAG suppression is not.
A COMPUTER MODEL ALLOWING MAINTENANCE OF LARGE AMOUNTS OF GENETIC VARIABILITY IN MENDELIAN POPULATIONS. II. THE BALANCE OF FORCES BETWEEN LINKAGE AND RANDOM ASSORTMENT
Authors: Wills Christopher , Miller Charles 
Published: April 2021

ABSTRACT
It is shown, through theory and computer simulations of outbreeding Mendelian populations, that there may be conditions under which a balance is struck between two factors. The first is the advantage of random assortment, which will, when multilocus selection is for intermediate equilibrium values, lead to higher average heterozygosity than when linkage is introduced. There is some indication that random assortment is also advantageous when selection is toward a uniform distribution of equilibrium values. The second factor is the advantage of linkage between loci having positive epistatic interactions. When multilocus selection is for a bimodal distribution of equilibrium values, an early advantage of random assortment is replaced by a later disadvantage. Linkage disequilibrium, which in finite populations is increased only by random or selective sampling, may hinder the movement of alleles to their selective equilibria, thus leading to the advantage of random assortment.—Some consequences of this approach to the structure of natural populations are discussed.