scholarly journals Regular responses to selection I. Description of responses

1961 ◽  
Vol 2 (2) ◽  
pp. 161-176 ◽  
Author(s):  
J. M. Thoday ◽  
T. B. Boam
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
Gene Interactions ◽  
Selection Experiment ◽  
Recombinational Event ◽  
Set Up

1. Several lines of Drosophila melanogaster have been selected for increase of sternopleural chaeta-number.2. Three lines of the same origin, dp 1, dp 2 and dp 6, showed remarkably similar patterns of response involving an accelerated response from 24 to 28 chaetae and a plateau at about 30 chaetae. A line formed by crossing two of these was not responsive to selection, suggesting that the two parent lines were genetically similar.3. A fourth line, vg 4, related to these others, showed a similar accelerated response but continued to respond beyond 30 chaetae, reaching a plateau at about 37 chaetae.4. A further line, vg 6, set up by crossing two ‘improved’ lines, one with 30, the other with 22 chaetae, reached 46 chaetae and suggests there may sometimes be merit in selecting from the hybrids of ‘improved’ strains.5. It is argued that the event making possible the accelerated response is probably a recombinational event.6. The line vg 4 clearly demonstrates that some of the genes that may be exploited in a selection experiment have to be exploited in a particular order because of gene interactions.

scholarly journals Heritability of Directional Asymmetry in Drosophila melanogaster

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Ashley J. R. Carter ◽  
Elizabeth Osborne ◽  
David Houle
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Artificial Selection ◽  
Natural Variation ◽  
The Other ◽  
Directional Asymmetry ◽  
Consistent Difference ◽  
Selection Experiment ◽  
Response To Selection ◽  
Powerful Technique

Directional asymmetry (DA), the consistent difference between a pair of morphological structures in which the same side is always larger than the other, presents an evolutionary mystery. Although many paired traits show DA, genetic variation for DA has not been unambiguously demonstrated. Artificial selection is a powerful technique for uncovering selectable genetic variation; we review and critique the limited number of previous studies that have been performed to select on DA and present the results of a novel artificial selection experiment on the DA of posterior crossvein location in Drosophila wings. Fifteen generations of selection in two genetically distinct lines were performed and none of the lines showed a significant response to selection. Our results therefore support and reconfirm previous findings; despite apparent natural variation and evolution of DA in nature, DA remains a paradoxical trait that does not respond to artificial selection.

scholarly journals Functional interactions of neurogenic genes of Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 118 (3) ◽  
pp. 499-508
Author(s):  
A de-la-Concha ◽  
U Dietrich ◽  
D Weigel ◽  
J A Campos-Ortega
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
Gene Interactions ◽  
Wild Type Allele ◽  
Wild Type ◽  
Present Evidence ◽  
Type Allele ◽  
Functional Interactions ◽  
Neurogenic Genes ◽  
Enhancer Of Split

Abstract The neurogenic genes of Drosophila melanogaster are involved in the decision of ectodermal cells to take on a neural or an epidermal fate. We present evidence in support of the notion that six of the neurogenic genes are functionally related. We studied the phenotype of embryos lacking one of the neurogenic genes in the presence of an increased dosage of the wild-type allele of another neurogenic gene. Our analysis also included the Hairless locus, whose function is related to that of the neurogenic genes, as well as to many other genes. The effects observed were asymmetric in that triploidy for a given gene modified the phenotype of loss of the function of another gene, but triploidy of the latter gene did not modify the phenotype of loss of the function of the former gene. These asymmetries allowed us to establish a polarity of gene interactions, as well as to order the genes according to the assumed ability of some of them to modify the activity of others. In this sequence, almondex is the first link and Enhancer of split the last one. Our evidence suggests that the function of big brain is independent of the function of the other six. The consequences of this arrangement for the commitment of ectodermal cells are discussed.

Doctrine and Dialectic in Plato’s Dialogues

2018 ◽  
Author(s):  
Rachana Kamtekar
Keyword(s):  
Methodological Approach ◽  
The Other ◽  
Set Up

Chapter 1 lays out the methodological approach employed throughout the book, which is to pay attention to the dialectical dependence of what the main speaker in the dialogue says on the intellectual problem(s) set up in the dialogue both by himself and the other speakers. To illustrate, Chapter 1 describes Socrates’ use of the method of hypotheses from the Meno and Phaedo to answer questions that go beyond his claims to knowledge in the Republic.

scholarly journals Preparation of alcohol-based handrub in COVID-19 Alsatian cluster

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Elodie Di-Falco ◽  
Johan Bourbon ◽  
Isalyne Sbaffe ◽  
Jean-Daniel Kaiser
Keyword(s):  
Critical Period ◽  
Hospital Management ◽  
Management Team ◽  
The Other ◽  
Packaging Materials ◽  
Local Production ◽  
Technical Grade ◽  
Hand Sanitizer ◽  
Set Up ◽  
Real Challenge

AbstractAlsace, in particular Haut-Rhin, is one of the main clusters of COVID-19 in France. There has been a shortage of essential supplies in the area, especially alcohol-based hand sanitizer. In this context, and in accordance with the decree dated March 6, 2020, our hospital management team asked us to start local production of alcohol-based handrub. This was a real challenge: In one week, we had to implement the production of handrub to meet the needs of a 1,400-bed hospital. The production had to comply with the French preparation guidelines and take place on specific premises, with qualified and calibrated equipment, by qualified staff, under the supervision of a pharmacist. The other big challenge we faced was the supply of pharmaceutical raw and packaging materials. During this particular critical period, all suppliers were out of stock. Here, we describe the organizational set-up and the decisions made, e. g., to use technical-grade ethanol before the publication of the decrees dated March 13 and March 23, 2020.

scholarly journals Transvection at the End of the Truncated Chromosome in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1375-1387
Author(s):  
Mikhail Savitsky ◽  
Tatyana Kahn ◽  
Ekaterina Pomerantseva ◽  
Pavel Georgiev
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Regulatory Region ◽  
Proximal Region ◽  
The Other ◽  
Upstream Region ◽  
Upstream Sequence ◽  
Transcription Start ◽  
Promoter Proximal Region

Abstract The phenomenon of transvection is well known for the Drosophila yellow locus. Thus enhancers of a promoterless yellow locus in one homologous chromosome can activate the yellow promoter in the other chromosome where the enhancers are inactive or deleted. In this report, we examined the requirements for trans-activation of the yellow promoter at the end of the deficient chromosome. A number of truncated chromosomes ending in different areas of the yellow regulatory region were examined in combination with the promoterless y alleles. We found that trans-activation of the yellow promoter at the end of a deficient chromosome required ∼6 kb of an additional upstream sequence. The nature of upstream sequences affected the strength of transvection: addition of gypsy sequences induced stronger trans-activation than addition of HeT-A or yellow sequences. Only the promoter proximal region (within -158 bp of the yellow transcription start) was essential for trans-activation; i.e., transvection did not require extensive homology in the yellow upstream region. Finally, the yellow enhancers located on the two pairing chromosomes could cooperatively activate one yellow promoter.

scholarly journals Quantitative investigation reveals distinct phases in Drosophila sleep

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaochan Xu ◽  
Wei Yang ◽  
Binghui Tian ◽  
Xiuwen Sui ◽  
Weilai Chi ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
General Pattern ◽  
Model Organism ◽  
Infrared Camera ◽  
Fruit Fly ◽  
Genetic Dissection ◽  
Power Law Distribution ◽  
Quantitative Investigation ◽  
Waking Up ◽  
Set Up

AbstractThe fruit fly, Drosophila melanogaster, has been used as a model organism for the molecular and genetic dissection of sleeping behaviors. However, most previous studies were based on qualitative or semi-quantitative characterizations. Here we quantified sleep in flies. We set up an assay to continuously track the activity of flies using infrared camera, which monitored the movement of tens of flies simultaneously with high spatial and temporal resolution. We obtained accurate statistics regarding the rest and sleep patterns of single flies. Analysis of our data has revealed a general pattern of rest and sleep: the rest statistics obeyed a power law distribution and the sleep statistics obeyed an exponential distribution. Thus, a resting fly would start to move again with a probability that decreased with the time it has rested, whereas a sleeping fly would wake up with a probability independent of how long it had slept. Resting transits to sleeping at time scales of minutes. Our method allows quantitative investigations of resting and sleeping behaviors and our results provide insights for mechanisms of falling into and waking up from sleep.

scholarly journals Astronomy to understand a human environment

1998 ◽  
Vol 162 ◽  
pp. 211-213
Author(s):  
S. Isobe
Keyword(s):  
School System ◽  
Environmental Science ◽  
The Other ◽  
Human Environment ◽  
Science Courses ◽  
The Public ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Set Up ◽  
School Period

Astronomy is an important science in understanding a human environment. However, it is thought by most politicians, economists, and members of the public that astronomy is a pure science having no contribution to daily human activities except a few matters relating to time. The Japanese government is studying a reorganisation of our school system to have 5 school days per week, instead of 6 days per week, and this July its committee made a recommendation to reduce school hours for science and set up new courses for practical computers and environmental science. I currently made a proposal. It is very difficult for most of the school pupils, who will have non-scientific jobs, to understand science courses currently taught in school, because each science is taught independently from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not greatly help their understanding of global environmental problems.

Statics Analysis of the Mechanical Model of Nucleosome

2011 ◽  
Vol 343-344 ◽  
pp. 661-667 ◽  
Author(s):  
Yun Xue ◽  
De Wei Weng ◽  
Gang Ming Gong
Keyword(s):  
Mechanical Model ◽  
The Other ◽  
Elastic Rod ◽  
Equilibrium Equations ◽  
Constraint Force ◽  
Precession Angle ◽  
Nutation Angle ◽  
Analytic Expression ◽  
Set Up ◽  
Calculated Analysis

Mechanical model of nucleoside and its equilibrium equations are set up, and the mechanical properties on the equilibrium position are analyzed. In the case constraint force and electrostatic attraction between cylinder OH and elastic rod are balanced, the analytic expression of nutation angle of the section and its conditions of existence are given. It is show that the cylinder OH can maintain equilibrium at any range of the precession angle. In the other case when unbanced, there is phenomenon of separation of elastic rod from cylinder OH in the spiral wound 2 circles, and numerical solution of the precession angle at separation points are calculated. Analysis of equilibrium of cylinder H1 illustrates that the generatrix of cylinder H1 and OH are not parallel, and the angle between them is obtained

scholarly journals Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 353-364 ◽  
Author(s):  
Jerry A Coyne
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Species Difference ◽  
The Other ◽  
Chromosome 3 ◽  
Apparent Effect ◽  
The Third ◽  
Hydrocarbon Profile ◽  
The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

Federal Aviation Administration’s Probability of Detection Testing Results for Structural Health Monitoring (SHM)

2021 ◽  
Author(s):  
Paul Swindell ◽  
Danielle Stephens
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Federal Aviation Administration ◽  
Steering Committee ◽  
Probability Of Detection ◽  
The Other ◽  
Atlantic City ◽  
Commercial Aviation ◽  
Structural Health ◽  
Set Up

Abstract The Federal Aviation Administration (FAA) has been participating with the Society of Automotive Engineers (SAE) Aerospace Industry Steering Committee (AISC) to develop a methodology for calculating the Probability of Detection (POD) for Structural Health Monitoring (SHM) for damage detection on commercial aviation. Two POD methodologies were developed: one by Dr. William Meeker, Iowa State University, and the other by Dennis Roach, Sandia National Laboratories (SNL). With Dr. Seth Kessler, Metis Design Corp, a test program of 24 samples of aluminum strips to be fatigued on MTS machines was developed. The samples were designed to meet the ASTM E647. Twelve samples had two SHM modalities on the front and back from Metis (PZT and carbon nanotubes), and the other twelve had SHM sensors from Structural Monitoring Systems (SMS) (comparative vacuum monitoring – CVM) and Acellent Technologies (PZT). The tests were performed at the FAA William J Hughes Technical Center in Atlantic City, NJ. The samples were cycled every 1500 cycles and then stopped for SHM data collection. Once the crack exceeded 0.125 inches and provided for a minimum of 15 inspections, a new sample was tested until all 12 samples were completed. The data was provided to each company to be set up in the format needed to run through the POD methodologies. Then the data was provided to Dr. Meeker and Dr. Roach for analysis. This paper will provide the results of those tests.

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