scholarly journals CHROMOSOMAL ANALYSIS OF DDT-RESISTANCE IN A LONG-TERM SELECTED POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1977 ◽  
Vol 87 (4) ◽  
pp. 685-697
Author(s):  
D Dapkus ◽  
D J Merrell
Keyword(s):  
Drosophila Melanogaster ◽  
Resistance Genes ◽  
Large Scale ◽  
Genetic Basis ◽  
Chromosomal Analysis ◽  
Positive Interactions ◽  
Ddt Resistance ◽  
High Level ◽  
And Control

ABSTRACT The genetic basis of DDT-resistance was studied in a population of Drosophila melanogaster. This population was unique in that it had been continually selected for DDT-resistance since 1952 and had achieved a very high level of resistance. The genetic basis of resistance was studied by means of a chromosomal analysis. Fifteen combinations of resistant and control chromosomes were tested using a time-based DDT test. The analysis of the data showed that resistance was multifactorial with each of the three major chromosomes involved. Dominant and recessive second and third chromosome effects were found to be much more important than those of the first chromosome, which had no detectable recessive effects. Second and third chromosome resistance genes showed incomplete dominance. The average dominance of the second chromosome was much less than that of the third chromosome. These large-scale differences between chromosomes' effects and average dominance may indicate that a small number of resistance genes are involved. Two significant interactions between chromosomes were found. Scaling difficulties make the interactions difficult to interpret without further data. It seems possible that positive interactions between resistance have been developed by the long-term directional selection in this population.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

Corporate Structure, Industrial Development, and Structural Change in South Africa

2021 ◽  
pp. 348-374
Author(s):  
Pamela Mondliwa ◽  
Simon Roberts
Keyword(s):  
South Africa ◽  
South African ◽  
Industrial Development ◽  
Large Scale ◽  
Economies Of Scale ◽  
Corporate Structure ◽  
Continuity And Change ◽  
Economic Concentration ◽  
And Control

The orientation of large corporations is at the heart of how countries develop. These firms make large-scale investments and realize economies of scale and scope, as well as make long-term commitments to the learning and research necessary to build capabilities required for industrial development. In many industries and sectors the large firms have key technologies, govern access to markets, and control material inputs which can shape the structure of an economy. The chapter reviews the changing corporate structure in South Africa focusing on the implications for industrial development, the evolving internationalization of South African businesses, and the political economy of economic policy. While the South African economy has remained highly concentrated, the corporate structure has altered in fundamental ways. The chapter identifies key elements of continuity and change to explain the implications of the continued high levels of economic concentration for the economy through the lens of the corporate structure.

scholarly journals FORMATION OF RESEARCH COMPETENCIES IN THE PROCESS OF TRAINING PENITENTIARY PSYCHOLOGISTS

2020 ◽  
Vol 2 ◽  
pp. 315
Author(s):  
Irina Slobodskaya ◽  
Elena Filipova ◽  
Oxana Martynyuk
Keyword(s):  
Information Technologies ◽  
Law And Economics ◽  
Education Institution ◽  
Mathematical Methods ◽  
Research Competencies ◽  
Training Courses ◽  
High Level ◽  
And Control ◽  
Long Term Experience

Training of penitentiary psychologists on the educational program «Psychology of official activity» is conducted in two universities of the Federal penitentiary service (FSIN of Russia). An important component of the practical and scientific activities of the penitentiary psychologist is the development, conduct and analysis of various psychological studies that require a high level of development of the necessary competencies. This article discusses the author's methodology IVDRC (Individual vector of development of research competencies), used in the training of penitentiary psychologists in the study of mathematical methods in psychology. The methodology is based on the continuity and professional orientation of training courses, individual approach, support and control of the stages of study of disciplines, the use of information technologies, own methodological materials and manuals. The developed technique is a generalization of long-term experience of teaching mathematical disciplines in departmental higher education institution. The technique of IVDRC has been successfully used for several years at the psychological faculty of the Vologda Institute of Law and Economics of the Federal Penal Service of Russia. To date, more than 150 cadets have been trained using the technology of IVDRC. The article analyzes some results and efficiency of its application using statistical methods. 

Single-dose AAV-based vaccine induces a high level of neutralizing antibodies and provides long-term protection against SARS-CoV-2 in rhesus macaques

2021 ◽  
Author(s):  
Dali Tong ◽  
Mei Zhang ◽  
Yunru Yang ◽  
Han Xia ◽  
Haiyang Tong ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Prevention And Control ◽  
Rhesus Macaques ◽  
Single Shot ◽  
Receptor Binding Domain ◽  
Global Public Health ◽  
Adeno Associated Virus ◽  
High Level ◽  
And Control

Coronavirus disease 2019 (COVID-19), which is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, continues to threaten global public health. Developing a vaccine that only requires single immunization but provides long-term protection for the prevention and control of COVID-19 is important. Here, we developed an adeno-associated virus (AAV)-based vaccine expressing a stable receptor-binding domain (SRBD) protein. The vaccine requires only single shot, but provides effective neutralizing antibodies (NAbs) over 300 days in rhesus macaques (Macaca mulatta). In addition, the NAbs are at much higher levels than seen in the sera of convalescent patients. It is worth to note that though we detected the pre-existing AAV2/9 NAbs before immunization, the vaccine still induced high and effective NAbs, and did not boost the AAV2/9 NAbs levels in rhesus macaques. Importantly, AAV-SRBD immune sera efficiently neutralized the SARS-CoV-2 P.1/P.2, B.1.1.7, and B.1.351 variants. Together, all the data suggest the vaccine has great potential in preventing the spread of SARS-CoV-2.

scholarly journals Cloud vertical structure over a tropical station obtained using long-term high resolution Radiosonde measurements

2018 ◽  
Author(s):  
Nelli Narendra Reddy ◽  
Madineni Venkat Ratnam ◽  
Ghouse Basha ◽  
Varaha Ravikiran
Keyword(s):  
Large Scale ◽  
Vertical Structure ◽  
Lower Layer ◽  
Monsoon Season ◽  
Single Layer ◽  
Cloud Base ◽  
High Level ◽  
Tropical Station ◽  
Layer Cloud

Abstract. Cloud vertical structure, including top and base altitudes, thickness of cloud layers, and the vertical distribution of multi-layer clouds affects the large-scale atmosphere circulation by altering gradients in the total diabatic heating/cooling and latent heat release. In this study, long-term (11 years) observations of high vertical resolution radiosondes are used to obtain the cloud vertical structure over a tropical station, Gadanki (13.5° N, 79.2° E), India. The detected cloud layers are verified with independent observations using cloud particle sensor (CPS) sonde launched from the same station. High-level clouds account for 69.05 %, 58.49 %, 55.5 %, and 58.6 % of all clouds during pre-monsoon, monsoon, post-monsoon, and winter seasons, respectively. The average cloud base (cloud top) altitude for low-level, middle-level, high-level and deep convective clouds are 1.74 km (3.16 km), 3.59 km (5.55 km), 8.79 km (10.49 km), and 1.22 km (11.45 km), respectively. Single-layer, two-layer, and three-layer clouds account for 40.80 %, 30.71 %, and 19.68 % of all cloud configurations, respectively. Multi-layer clouds occurred more frequently during the monsoon with 34.58 %. Maximum cloud top altitude and the cloud thickness occurred during monsoon season for single-layer clouds and the uppermost layer of multiple layer cloud configurations. In multi-layer cloud configurations, diurnal variations in the thickness of upper layer clouds are larger than those of lower layer clouds. Heating/cooling in the troposphere and lower stratosphere due to these clouds layers is also investigated and found peak cooling (peak warming) below (above) the Cold Point Tropopause (CPT) altitude. The magnitude of cooling (warming) increases from single-layer to four or more-layer cloud occurrence. Further, the vertical structure of clouds is also studied with respect to the arrival date of Indian summer monsoon over Gadanki.

scholarly journals Data-driven traffic and diffusion modeling in peer-to-peer networks: A real case study

2014 ◽  
Vol 2 (3) ◽  
pp. 341-366
Author(s):  
ROMAIN HOLLANDERS ◽  
DANIEL F. BERNARDES ◽  
BIVAS MITRA ◽  
RAPHAËL M. JUNGERS ◽  
JEAN-CHARLES DELVENNE ◽  
...  
Keyword(s):  
Large Scale ◽  
Synthetic Data ◽  
Real Data ◽  
Peer To Peer ◽  
Free Riders ◽  
Peer Network ◽  
Peer To Peer Networks ◽  
Peer To Peer Systems ◽  
High Level ◽  
And Control

AbstractPeer-to-peer systems have driven a lot of attention in the past decade as they have become a major source of Internet traffic. The amount of data flowing through the peer-to-peer network is huge and hence challenging both to comprehend and to control. In this work, we take advantage of a new and rich dataset recording the peer-to-peer activity at a remarkable scale to address these difficult problems. After extracting the relevant and measurable properties of the network from the data, we develop two models that aim to make the link between the low-level properties of the network, such as the proportion of peers that do not share content (i.e., free riders) or the distribution of the files among the peers, and its high-level properties, such as the Quality of Service or the diffusion of content, which are of interest for supervision and control purposes. We observe a significant agreement between the high-level properties measured on the real data and on the synthetic data generated by our models, which is encouraging for our models to be used in practice as large-scale prediction tools. Relying on them, we demonstrate that spending efforts to reduce the amount of free riders indeed helps to improve the availability of files on the network. We observe however a saturation of this phenomenon after 60% of free riders.

scholarly journals Thermal–hydraulic–mechanical (THM) behaviour of a large-scale in situ heating experiment during cooling and dismantling

2012 ◽  
Vol 49 (10) ◽  
pp. 1169-1195 ◽  
Author(s):  
M. Sánchez ◽  
A. Gens ◽  
L. Guimarães
Keyword(s):  
Large Scale ◽  
Element Formulation ◽  
Model Predictions ◽  
Engineered Barriers ◽  
Heating Test ◽  
High Level ◽  
Fully Coupled ◽  
Clay Barrier

A geological disposal facility for high-level radioactive waste (HLW) encompasses both natural (host rock) and (generally clay-based) engineered barriers. Many processes can influence, either positively or negatively, the effectiveness of the safety functions of isolation and retardation. This paper focuses on the analysis of a large-scale heating test when subjected to cooling and subsequent partial dismantling. The experiment reproduces the conditions of an HLW repository at full scale under realistic conditions. Key thermal, hydraulic, and mechanical (THM) variables, such as temperature, relative humidity, stresses, and fluid pressures, were measured in the clay barrier and surrounding rock. The experimental observations recorded during the cooling down and clay barrier excavation are analyzed in light of a fully coupled THM finite element formulation. This analysis has provided the opportunity to explore the behaviour of the clay and natural barriers under conditions very relevant for the repository performance but not analyzed previously. Overall, the model predictions are quite satisfactory when compared against experimental observations. Furthermore, model predictions for a period of 20 years, including the transient phase induced by the partial dismantling, are also presented. This additional analysis has allowed a better understanding of the effect of thermal gradient on long-term clay hydration.

scholarly journals The structure and organization of an Amazonian bird community remains little changed after nearly four decades

2021 ◽  
Author(s):  
Ari Martinez ◽  
Jose Ponciano ◽  
Juan Gomez ◽  
Thomas Valqui ◽  
Jorge Novoa ◽  
...  
Keyword(s):  
Large Scale ◽  
Bird Community ◽  
Forest Reserves ◽  
Spatio Temporal ◽  
Mixed Species Flocks ◽  
High Level ◽  
Bird Distribution ◽  
Manu National Park ◽  
Apparent Stability

Documenting patterns of spatio-temporal change in hyper-diverse communities remains a challenge for tropical ecology, yet is increasingly urgent as some long-term studies have shown major declines in bird communities even in relatively undisturbed sites. In 1982, Terborgh et al. quantified the structure and organization of the bird community in a 97-ha. plot in southeastern Peru. We revisited the same plot in 2018 and repeated the same intense combination of methodologies as the original study in order to evaluate community-wide changes. Contrary to the results from studies elsewhere, we found little change in bird distribution and abundance within the plot, although there were some declines related to loss of mixed-species flocks with a high level of species interdependence. This apparent stability suggests that large-scale forest reserves such as Manu National Park may provide the conditions necessary for establishing refugia from at least some of the effects of global change on birds.

Do the “Spreadability” and Finger Length of Cellists and Guitarists Change Due to Practice?

2000 ◽  
Vol 15 (1) ◽  
pp. 23-30
Author(s):  
Renate Kloeppel
Keyword(s):  
Teaching Methods ◽  
Large Scale ◽  
Control Group ◽  
Left Hand ◽  
Finger Length ◽  
Left Elbow ◽  
Comparison Groups ◽  
The Right ◽  
And Control

It is a widely held opinion among musicians that extreme joint positions increase the flexibility in the corresponding joints. There are also occasional views that extensive use of the fingers starting in childhood may lead to increased finger length. These opinions have implications for teaching methods; however, in spite of extensive examinations of the shapes of musicians’ hands, to date there have been almost no objective findings. There have been large-scale examinations of the angle of supination of the left elbow of violinists, with the finding that primarily genetic factors are responsible. In order to answer the question whether external factors can influence joint configurations of the hand as well as finger length, the active finger spreads and finger lengths of 210 subjects (cellists, guitarists, and control subjects) were measured. The working hypothesis was that there would be an increase in finger spread in the left hand fingers compared with the right if the frequent extreme positions taken on the fingerboard did in fact influence finger spread. The nonmusician control group, however, would not be expected to show this difference, or at least not to the same extent as in the musicians. Similar differences should apply to finger length, if this is influenced by long-term practicing on these instruments. A majority of the measurements of all three groups demonstrated a greater spreadability of the fingers of the left hand than of the right. In contrast to the comparison groups, there was a significantly greater span between the left hand index and small fingers of cellists. This span was not measured in the guitarists because it does not apply in their playing as it does for cellists. In addition, the measurements of the right-left differences in the finger lengths of the cellists when compared with the nonmusician group showed significantly longer fingers on the left than the right. This difference is probably caused by better-developed fingertips of the cellists. Further research is needed to discern whether the spreadability could be improved through specific training programs.

scholarly journals The effect of cryopreservation on the lethal mutation rate in Drosophila melanogaster

1997 ◽  
Vol 69 (3) ◽  
pp. 209-213 ◽  
Author(s):  
DAVID HOULE ◽  
ALEXEY S. KONDRASHOV ◽  
LEV YU. YAMPOLSKY ◽  
SHANNON CALDWELL ◽  
PETER L. STEPONKUS
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Mutagenic Effect ◽  
Genetic Impact ◽  
Mutagenic Effects ◽  
And Control ◽  
Biological Organisms ◽  
Long Term Studies ◽  
Cryopreserved Embryos

Although cryopreservation is routinely used for the storage of a range of biological organisms, few studies have been conducted to determine whether cryopreservation increases the frequency of mutation. A procedure for the cryopreservation of Drosophila melanogaster embryos has recently been developed. Cryopreservation of D. melanogaster is of special interest to geneticists and evolutionary biologists because it would make it possible to assay control and experimental populations simultaneously during long-term studies. Before cryopreserved embryos can be used for such studies, it is first necessary to show that cryopreservation is not mutagenic. We tested for mutagenic effects of cryopreservation in D. melanogaster embryos with an X-linked, recessive lethal assay. The mutation rates of cryopreserved and control flies were not significantly different. We can be 95% certain that cryopreservation does not increase mutation by a factor greater than 2·39. This is the first quantitative estimate of the mutagenic effect of cryopreservation on the germ line of a metazoan. The results are reassuring when considering the genetic impact of cryopreservation on mammalian gametes and embryos.

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