scholarly journals Micro-environmental conditions and high population density affects the transmission of severe acute respiratory syndrome corona virus-2 in metropolitan cities of India

2021 ◽  
Vol 6 (4) ◽  
pp. 116
Author(s):  
Seema Mishra ◽  
Sanjay Dwivedi ◽  
Ruchi Agnihotri ◽  
Vishnu Kumar ◽  
Pragya Sharma ◽  
...  
Keyword(s):  
Population Density ◽  
Severe Acute Respiratory Syndrome ◽  
Environmental Conditions ◽  
High Population ◽  
High Population Density ◽  
Corona Virus ◽  
Metropolitan Cities

scholarly journals COVID-19 Pandemic in India: A Mathematical Model Study

2020 ◽  
Author(s):  
Sudhanshu Kumar Biswas ◽  
Jayanta Kumar Ghosh ◽  
Susmita Sarkar ◽  
Uttam Ghosh
Keyword(s):  
Population Density ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Virus Disease ◽  
Control Measures ◽  
High Population ◽  
Model Parameters ◽  
High Population Density ◽  
Corona Virus ◽  
Very High

The present novel corona virus (2019-nCoV) infection has created a global emergency situation by spreading all over the world in a large scale within very short time period. The infection induced death rate is also very high. There is no vaccine or anti-viral medicine for such infection. So at this moment a major worldwide problem is that how we can control this pandemic. On the other hand, India is a high population density country, where the corona virus disease (COVID-19) has started to spread from $1^{st}$ week of March, 2020 in a significant number of COVID-19 positive cases. Due to this high population density human to human social contact rate is very high in India. So control of the pandemic COVID-19 in early stage is very urgent and challenging problem. Mathematical models are employed in this paper to study the COVID-19 dynamics, to identify the influential parameters and to find the proper prevention strategies to reduce the outbreak size. In this work, we have formulated a deterministic compartmental model to study the spreading of COVID-19 and estimated the model parameters by fitting the model with reported data of ongoing pandemic in India. Sensitivity analysis has been done to identify the key model parameters. The basic reproduction number has been estimated from actual data and the effective basic reproduction number has been studied on the basis of reported cases. Some effective preventive measures and their impacts on the disease dynamics have also been studied. Future trends of the disease transmission has been Predicted from our model with some control measures. Finally, the positive measures to control the disease have been summarized.

scholarly journals Recruitment sex ratios in gray-tailed voles (Microtus canicaudus) in response to density, sex ratio, and season

2003 ◽  
Vol 81 (8) ◽  
pp. 1306-1311 ◽  
Author(s):  
Monica L Bond ◽  
Jerry O Wolff ◽  
Sven Krackow
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Resource Competition ◽  
Sex Ratios ◽  
Female Offspring ◽  
High Population ◽  
Reproductive Value ◽  
High Population Density ◽  
Adult Sex Ratio ◽  
Sex Ratio Adjustment

We tested predictions associated with three widely used hypotheses for facultative sex-ratio adjustment of vertebrates using eight enclosed populations of gray-tailed voles, Microtus canicaudus. These were (i) the population sex ratio hypothesis, which predicts that recruitment sex ratios should oppose adult sex-ratio skews, (ii) the local resource competition hypothesis, which predicts female-biased recruitment at low adult population density and male-biased recruitment at high population density, and (iii) the first cohort advantage hypothesis, which predicts that recruitment sex ratios should be female biased in the spring and male biased in the autumn. We monitored naturally increasing population densities with approximately equal adult sex ratios through the spring and summer and manipulated adult sex ratios in the autumn and measured subsequent sex ratios of recruits. We did not observe any significant sex-ratio adjustment in response to adult sex ratio or high population density; we did detect an influence of time within the breeding season, with more female offspring observed in the spring and more male offspring observed in the autumn. Significant seasonal increases in recruitment sex ratios indicate the capacity of female gray-tailed voles to manipulate their offspring sex ratios and suggest seasonal variation in the relative reproductive value of male and female offspring to be a regular phenomenon.

Aggregations of masked shrews ( Sorex cinereus ): density-related mating behavior? / Agrégation de musaraignes masquées ( Sorex cinereus ): accouplement relatif à la densité de la population?

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Thomas J. Maier ◽  
Katherine L. Doyle
Keyword(s):  
Population Density ◽  
Mating Behavior ◽  
High Population ◽  
High Population Density ◽  
Genetic Analyses ◽  
Highly Active ◽  
Sorex Cinereus

AbstractLarge aggregations of shrews have been reported and various explanations offered for this seemingly rare behavior; however, there has been little evidence to support any particular interpretation. We observed two small aggregations of highly active vocalizing Sorex cinereus while performing wildlife surveys in forested habitats in central Massachusetts, USA. These observations, in conjunction with a review of other reports, including genetic analyses, strongly suggest that such aggregations of adult Sorex are associated with mating behavior, more readily observed during periods of high population density. Published accounts of such behavior may be rare because primarily large aggregations have been reported; however, smaller breeding aggregations may be common.

Analysis of steroid hormone levels in female mice at high population density

1998 ◽  
Vol 64 (4) ◽  
pp. 529-533 ◽  
Author(s):  
John C Chapman ◽  
John J Christian ◽  
Mary Ann Pawlikowski ◽  
Sandra D Michael
Keyword(s):  
Population Density ◽  
Steroid Hormone ◽  
High Population ◽  
High Population Density ◽  
Hormone Levels ◽  
Female Mice

Environmental Issues Regarding Space Launches over the Black Sea

2013 ◽  
Vol 330 ◽  
pp. 805-810
Author(s):  
Dragos R. Rugescu
Keyword(s):  
Population Density ◽  
Black Sea ◽  
Environmental Issues ◽  
High Population ◽  
The Black Sea ◽  
Western Coast ◽  
High Population Density ◽  
Research Activity ◽  
The West ◽  
Space Project

The Romanian NERVA space project, aimed at building and using a small rocket launcher for injecting nanosatellites into a LEO, requires the establishment of a secure launching area. The first candidate is on the western coast of the Black Sea and the candidate launching and flight corridor is the west-east vector above the sea. A series of ecological and safety challenges appear due to the high population density of the regions close to the sea-shores of the Black Sea; they must be catalogued and securely solved, before any space activity above the Black Sea begins. The main challenges of such an endeavor are analyzed henceforth and several solutions that fall within the scope of a recent research activity of the NERVA team are proposed.

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