population density
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2022 ◽  
Vol 11 (1) ◽  
pp. 64
Giedrė Beconytė ◽  
Andrius Balčiūnas ◽  
Aurelija Šturaitė ◽  
Rita Viliuvienė

This paper proposes a method for quantitative evaluation of perception deviations due to generalization in choropleth maps. The method proposed is based on comparison of class values assigned to different aggregation units chosen for representing the same dataset. It is illustrated by the results of application of the method to population density maps of Lithuania. Three spatial aggregation levels were chosen for comparison: the 1 × 1 km statistical grid, elderships (NUTS3), and municipalities (NUTS2). Differences in density class values between the reference grid map and the other two maps were calculated. It is demonstrated that a perceptual fallacy on the municipality level population map of Lithuania leads to a misinterpretation of data that makes such maps frankly useless. The eldership level map is, moreover, also largely misleading, especially in sparsely populated areas. The method proposed is easy to use and transferable to any other field where spatially aggregated data are mapped. It can be used for visual analysis of the degree to which a generalized choropleth map is liable to mislead the user in particular areas.

2022 ◽  
Vol 12 (1) ◽  
Tsuneya Yoshida ◽  
Tomonari Mizoguchi ◽  
Yasuhiro Hatsugai

AbstractNon-Hermitian topology is a recent hot topic in condensed matters. In this paper, we propose a novel platform drawing interdisciplinary attention: rock–paper–scissors (RPS) cycles described by the evolutionary game theory. Specifically, we demonstrate the emergence of an exceptional point and a skin effect by analyzing topological properties of their payoff matrix. Furthermore, we discover striking dynamical properties in an RPS chain: the directive propagation of the population density in the bulk and the enhancement of the population density only around the right edge. Our results open new avenues of the non-Hermitian topology and the evolutionary game theory.

2022 ◽  
Vol 12 (3) ◽  
pp. 324-359
Alcinéia Miranda Campos ◽  
Francisco Gean Freitas do Nascimento ◽  
Helenilza Ferreira Albuquerque Cunha

We herein assess population growth in indigenous lands (ILs) Wajãpi, Uaçá, Galibi and Juminã in Amapá State-Brazil, which has influenced deforestation increase. We assumed the hypothesis of no association between demographic density and deforestation because population density in these areas is low. We used population growth, deaths, and deforestation data by considering a historical series (2002-2018). Demographic data have shown that Uaçá and Wajãpi ILs recorded the highest population growth. The highest demographic density was observed for Galibi ILs and the lowest one for Wajãpi ILs. The highest deforestation was observed for Uaçá ILs and the lowest one for Juminã ILs. Therefore, indigenous lands in Amapá State have an essential role in forest conservation.

Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He

Animals can adjust reproductive strategies in favour of corporation or competition in response to local population size and density, the two key factors of social environments. However, previous studies usually focus on either population size or density but ignore their interactions. Using a haplodiploid spider mite, Tetranychus ludeni Zacher, we carried out a factorial experiment in the laboratory to examine how ovipositing females adjust their fecundity and offspring sex ratio during their early reproductive life under various population size and density. We reveal that females laid significantly more eggs with increasing population size and significantly fewer eggs with increasing population density. This suggests that large populations favour cooperation between individuals and dense populations increase competition. We demonstrate a significant negative interaction of population size and density that resulted in significantly fewer eggs laid in the large and dense populations. Furthermore, we show that females significantly skewed the offspring sex ratio towards female-biased in small populations to reduce the local mate competition among their sons. However, population density incurred no significant impact on offspring sex ratio, while the significant positive interaction of population size and density significantly increased the proportion of female offspring in the large and dense populations, which will minimise food or space competition as females usually disperse after mating at crowded conditions. These results also suggest that population density affecting sex allocation in T. ludeni is intercorrelated with population size. This study provides evidence that animals can manipulate their reproductive output and adjust offspring sex ratio in response to various social environments, and the interactions of different socio-environmental factors may play significant roles.

2022 ◽  
Vol 11 (1) ◽  
pp. e38411122133
Denise Rodrigues Conceição ◽  
Anderli Divina Ferreira Rios ◽  
Niusmar dos Santos Noronha Júnior ◽  
Ramon Ribeiro dos Santos ◽  
Rafael Matias da Silva ◽  

Nematodes are of great importance in soybean cultivation, especially the Pratylenchus brachyurus known as root lesion nematode. Its attack on plant roots causes less efficiency in the absorption of water and nutrients, in addition to damaging the plant's development. There is still no fully efficient method to control this phytopathogen, however, some products are available on the market, including biological control. Thus, the aim of this study was to evaluate commercial biological products in the efficiency of reducing the nematode population in soybean crop in Goiás, Brazil. The design was completely randomized in a 2x4 factorial scheme, the first factor being two soybean genotypes (Brasmax Bônus and Nidera NS 8383) and the second factor the treatments consisting of different dosages in an association of three commercial products: No-Estio®, Bio-fertility® and Radic®. The treatments used were: T1 control - without application of the products; T2 half the recommended dose; T3 the recommended dose and T4 a dose and a half that recommended by the manufacturer. Plant evaluation was carried out after 75 days of nematode inoculation. The results obtained showed that both cultivars hosted P. brachyurus, however, the treatments using the products had a lower population density of this nematode. It was concluded that the two soybean cultivars are hosts of Pratylenchus brachyurus. The agronomic character plant height was more affected when there was no application by the biological method. The association of No-Estio®, Bio-fertility® and Radic® products reduced the population density of nematodes in infected plants.

Javier Cifuentes-Faura

COVID-19 has caused an unprecedented crisis, resulting in a global pandemic with millions infected and dying. Given the importance given to sustainability and the reduction in pollutant gases in recent years, the main objective of this study was to determine whether pollutant emissions are associated with an increased number of COVID-19 cases in Europe. Other demographic variables that may have an impact on the number of coronavirus cases, such as population density, average age or the level of restrictive policies implemented by governments, are also included. It has been shown that the emission of carbon monoxide pollutant gases and pollutant emissions from transport positively affect the incidence of COVID-19, so that the sustainable policy implemented in recent years in Europe should be reinforced, and tougher sanctions and measures should be imposed when pollution thresholds are exceeded.

2022 ◽  
Kyle Shaw ◽  
Peter Beerli

The terms population size and population density are often used interchangeably, when in fact they are quite different. When viewed in a spatial landscape, density is defined as the number of individuals within a square unit of distance, while population size is simply the total count of a population. In discrete population genetics models, the effective population size is known to influence the interaction between selection and random drift with selection playing a larger role in large populations while random drift has more influence in smaller populations. Using a spatially explicit simulation software we investigate how population density affects the flow of new mutations through a geographical space. Using population density, selectional advantage, and dispersal distributions, a model is developed to predict the speed at which the new allele will travel, obtaining more accurate results than current diffusion approximations provide. We note that the rate at which a neutral mutation spreads begins to decay over time while the rate of spread of an advantageous allele remains constant. We also show that new advantageous mutations spread faster in dense populations.

2022 ◽  
Vol 22 (1) ◽  
Zhicheng Du ◽  
Boyi Yang ◽  
Bin Jalaludin ◽  
Luke Knibbs ◽  
Shicheng Yu ◽  

Abstract Background Hand, foot, and mouth disease (HFMD) is an epidemic infectious disease in China. Relationship of neighborhood greenness with human health has been widely studied, yet its association with severe HFMD has not yet been established. Methods Individual HFMD cases that occurred in Guangdong province in 2010 were recruited and were categorised into mild and severe cases. Residential greenness was assessed using global land cover data. We used a case-control design (i.e., severe versus mild cases) with logistic regression models to assess the association between neighborhood greenness and HFMD severity. Effect modification was also examined. Results A total of 131,606 cases were included, of whom 130,840 were mild cases and 766 were severe cases. In an unadjusted model, HFMD severity increased with higher proportion of neighborhood greenness (odds ratio, OR = 1.029, 95%CI: 1.009–1.050). The greenness-HFMD severity association remained (OR = 1.031, 95%CI: 1.006–1.057) after adjusting for population density, demographic variables and climate variables. Both population density (Z = 4.148, P < 0.001) and relative humidity (Z = -4.297, P < 0.001) modified the association between neighborhood greenness and HFMD severity. In the stratified analyses, a protective effect (OR = 0.769, 95%CI: 0.687–0.860) of greenness on HFMD severity were found in the subgroup of population density being lower than and equal to 5 ln(no.)/km2. While in both the subgroups of population density being higher than 5, the greenness had hazard effects (subgroup of > 5 & ≤7: OR = 1.071, 95%CI: 1.024–1.120; subgroup of > 7: OR = 1.065, 95%CI: 1.034–1.097) on HFMD severity. As to relative humidity, statistically significant association between greenness and HFMD severity was only observed in the subgroup of being lower than and equal to 76% (OR = 1.059, 95%CI: 1.023–1.096). Conclusions Our study found that HFMD severity is associated with the neighborhood greenness in Guangdong, China. This study provides evidence on developing a prevention strategy of discouraging the high-risk groups from going to the crowded green spaces during the epidemic period.

Recycling ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 1
Lamia Ben Amor ◽  
Sami Hammami

Over the past fifteen years, numerous policies for recycling and recovering waste have been implemented throughout the world. Tunisia is among the countries considering recycling as a sustainable development path. This empirical study aimed to investigate and examine the influence of financial determinants measured by the price of waste disposal (PDI), institutional determinants measured by the collection of waste (CW) and the number of drop-off recycling centers, and ordinance and demographic determinants measured by the population density and the recycling rate for plastic as a domestic waste based on a panel of 24 Tunisian governorates over the 2001–2020 period. It is concluded from the empirical findings that all exogenous variables except population density have a significant effect on the recycling rate.

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