THE POPULATION DYNAMICS OF IPS GRANDICOLLIS (EICHHOFF) (COLEOPTERA: SCOLYTIDAE) IN JAMAICA

1990 ◽  
Vol 122 (2) ◽  
pp. 217-227 ◽  
Author(s):  
Eric Garraway ◽  
B.E. Freeman
Keyword(s):  
Population Dynamics ◽  
Major Part ◽  
Egg Laying ◽  
Primary Role ◽  
Ips Grandicollis ◽  
Potential Pest ◽  
Population Numbers

AbstractIps grandicollis (Eichhoff) was first recorded from Jamaica in 1978 and has become a potential pest in Pinus plantations in the island. Its distribution there is determined by the occurrence of suitable food, but not by altitude or rainfall. Developmental mortality due to predators, parasites, and resin did not limit population numbers within logs: control resulted ultimately from competition among egg-laying females and among larvae for space in suitable logs. However, when the entire Jamaican population was considered, dispersive loss of adults played a major part in the limitation of numbers. A cyclic budget revealed that a minimum of 44% of the population was lost during dispersal. Dispersive loss in the males (77.3%) was higher than that in the females (35.4%), and this difference may be related to the primary role of the males in finding suitable logs.

Zoonoses as factor of evolution, population dynamics, and speciation

2021 ◽  
pp. 153-172
Author(s):  
Igor Evstafiev ◽  
Igor Zagorodniuk
Keyword(s):  
Population Dynamics ◽  
Small Mammals ◽  
Population Diversity ◽  
Crimean Peninsula ◽  
Species Ranges ◽  
Animal Populations ◽  
Tick Borne Encephalitis ◽  
Evolutionary Changes ◽  
Population Numbers

The role of zoonoses in changes of animal populations and communities is considered. The analysis was carried out using examples of population dynamics of small mammals distributed in the Crimean Peninsula, under the influence of the main zoonoses common for this territory, in particular tularaemia, leptospirosis, Marseille fever, viral tick-borne encephalitis, Ixodes tick-borne borreliosis, Crimea-Congo fever, KU fever, HFRS, and many others. Such data were analysed according to databases on the state of small-mammal populations and zoonoses common in these populations, obtained by original studies over the past 40 years. The role of zoonoses as factors of evolutionary changes in populations of small mammals is considered, in particular as a factor of mortality leading to significant reductions in population numbers and fragmentation of species ranges, as well as factors determining co-evolution of pathogens, vectors (arthropods), and small-mammals as hosts. Both groups of factors lead to the formation of population diversity due to changes in character variability and the formation of new characters associated with adaptations to zoonoses.

Sports Photography and Historical Development

2018 ◽  
Vol 5 (1) ◽  
pp. 93-115
Author(s):  
Miloš Stamenković
Keyword(s):  
Historical Development ◽  
Emotional Reaction ◽  
Main Role ◽  
Primary Role

SummarySports photography undoubtedly has a significant place in sports press and publicism. It’s main and primary role is to present sports to the readers as art, which it is. Sport is characterized by dynamic and varied movements, and the main role of sports photography is reflected in the fact that it is in this way that sport shows its essence. Having in mind that photography tells more than a thousand words it sends a clear message to the reader as well to people who are informed about events via sports portals. Sports photography is a multidimensional art for many reasons. When we say “multi”, it primarily refers to a wider range that sports photography has to offer, which means sports photography is not only directed at presenting athletes on the move and the main actors who contribute to achieving the results by their engagement – it also has the role of sports “psychophotography” which is an analysis and capture of the emotional reaction of an athlete after winning or losing from the opposing team.

OBOLESCENCE AND THE DIFFUSION OF INNOVATIONS

2020 ◽  
pp. 113-130
Author(s):  
A.V. GOLUBEV ◽  
Keyword(s):  
Diffusion Of Innovations ◽  
Time Lag ◽  
Practical Implementation ◽  
Primary Role ◽  
Innovation Development ◽  
Scientific Hypothesis ◽  
Scientific Papers ◽  
The Moment ◽  
Sociological Studies

The diffusion of innovations is described as a process in a number of scientific papers. At the same time, the causes of this process have not been sufficiently studied. The author’s goal is to consider the main regularities, under which the life cycle of innovations begins, and propose measures to enhance diffusion in modern conditions. As a scientific hypothesis, the author accepts the postulate about the primary role of the obolescence of attracted innovations in this process. The analysis revealed not only the economic proportions that initiate the start of innovation promotion, but also the influence on the diffusion rate of the obsolescence degree of innovations and the market share occupied by the new product. Methodological approaches have been developed to determine economic efficiency depending on the moment of technological change-over, as well as to determine the absolute and relative speed of innovation diffusion. Sociological studies were conducted to determine the state of innovation development and the time lag between obtaining information about an innovation and its practical implementation. The author presents his “Agroopyt” information system developed to disseminate knowledge in the agricultural sphere and ensure technology transfer in agriculture. Digital methods provide for significant accelerateion of the diffusion of innovations and expand its scope.

scholarly journals Do males matter? The role of males in population dynamics

Oikos ◽  
2007 ◽  
Vol 116 (2) ◽  
pp. 335-348 ◽  
Author(s):  
Daniel J. Rankin ◽  
Hanna Kokko
Keyword(s):  
Population Dynamics

scholarly journals Four Mutant Alleles Elucidate the Role of the G2 Protein in the Development of C4 and C3 Photosynthesizing Maize Tissues

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 787-797
Author(s):  
Lizzie Cribb ◽  
Lisa N Hall ◽  
Jane A Langdale
Keyword(s):  
Cell Types ◽  
Bundle Sheath ◽  
Primary Role ◽  
Ribulose Bisphosphate Carboxylase ◽  
Sheath Cell ◽  
Mesophyll Cells ◽  
Phenotypic Data ◽  
Bisphosphate Carboxylase ◽  
Bundle Sheath Cell

Abstract Maize leaf blades differentiate dimorphic photosynthetic cell types, the bundle sheath and mesophyll, between which the reactions of C4 photosynthesis are partitioned. Leaf-like organs of maize such as husk leaves, however, develop a C3 pattern of differentiation whereby ribulose bisphosphate carboxylase (RuBPCase) accumulates in all photosynthetic cell types. The Golden2 (G2) gene has previously been shown to play a role in bundle sheath cell differentiation in C4 leaf blades and to play a less well-defined role in C3 maize tissues. To further analyze G2 gene function in maize, four g2 mutations have been characterized. Three of these mutations were induced by the transposable element Spm. In g2-bsd1-m1 and g2-bsd1-s1, the element is inserted in the second intron and in g2-pg14 the element is inserted in the promoter. In the fourth case, g2-R, four amino acid changes and premature polyadenylation of the G2 transcript are observed. The phenotypes conditioned by these four mutations demonstrate that the primary role of G2 in C4 leaf blades is to promote bundle sheath cell chloroplast development. C4 photosynthetic enzymes can accumulate in both bundle sheath and mesophyll cells in the absence of G2. In C3 tissue, however, G2 influences both chloroplast differentiation and photosynthetic enzyme accumulation patterns. On the basis of the phenotypic data obtained, a model that postulates how G2 acts to facilitate C4 and C3 patterns of tissue development is proposed.

The Only Function of Grauzone Required for Drosophila Oocyte Meiosis Is Transcriptional Activation of the cortex Gene

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1831-1839
Author(s):  
Emily Harms ◽  
Tehyen Chu ◽  
Gwénola Henrion ◽  
Sidney Strickland
Keyword(s):  
Zinc Finger ◽  
Transcriptional Activation ◽  
Single Amino Acid ◽  
Primary Role ◽  
Extra Copy ◽  
Oocyte Meiosis ◽  
Zinc Finger Motifs ◽  
High Level ◽  
Transcriptional Pathway

Abstract The grauzone and cortex genes are required for the completion of meiosis in Drosophila oocytes. The grauzone gene encodes a C2H2-type zinc-finger transcription factor that binds to the cortex promoter and is necessary for high-level activation of cortex transcription. Here we define the region of the cortex promoter to which Grauzone binds and show that the binding occurs through the C-terminal, zinc-finger-rich region of the protein. Mutations in two out of the five grauzone alleles result in single amino acid changes within different zinc-finger motifs. Both of these mutations result in the inability of Grauzone to bind DNA effectively. To determine the mechanism by which Grauzone regulates meiosis, transgenic flies were produced with an extra copy of the cortex gene in homozygous grauzone females. This transgene rescued the meiosis arrest of embryos from these mutants and allowed their complete development, indicating that activation of cortex transcription is the primary role of Grauzone during Drosophila oogenesis. These experiments further define a new transcriptional pathway that controls the meiotic cell cycle in Drosophila oocytes.

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