Microfilaria density distribution in the human population and its infectivity index for the mosquito population

Parasitology ◽  
1988 ◽  
Vol 96 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Chai Bin Park
Keyword(s):  
Population Density ◽  
Density Distribution ◽  
Gamma Distribution ◽  
Blood Meal ◽  
Human Population ◽  
Host Population ◽  
Mosquito Population ◽  
Carrier Rate ◽  
Average Volume ◽  
Gamma Distributions

SummaryA new method of computing the infectivity index of microfilariae (mf) for the mosquito population is proposed using the estimated mf density distribution in the human population. The observed density distribution is considered a compound of the Poisson and the gamma distributions. The former distribution describes the probability of a specimen containing a specified number of mf and the latter describes the density distribution of mf in the host population. The mf infectivity index is the probability that a blood meal will include at least 1 mf, conditional on the population-density distribution of mf as specified by the gamma distribution. Actual data indicate that this population-density-based infectivity index can be considerably different from the conventional index based on the survey-density distribution. The level of the carrier rate of mf in a survey is greatly influenced, apart from the sample variation, by the average volume of blood taken from each person. The rate computed on the estimated population-density distribution of mf is convertible to any base amount of blood.

MODELLING AND ANALYSIS OF THE SPREAD OF MALARIA: ENVIRONMENTAL AND ECOLOGICAL EFFECTS

2005 ◽  
Vol 13 (01) ◽  
pp. 1-11 ◽  
Author(s):  
SHIKHA SINGH ◽  
J. B. SHUKLA ◽  
PEEYUSH CHANDRA
Keyword(s):  
Infectious Disease ◽  
Population Density ◽  
Human Population ◽  
Ecological Factors ◽  
Ecological Effects ◽  
Mosquito Population ◽  
Human Population Density ◽  
Survival And Growth

In this paper, general SIS and SIRS models with immigration of human population for the spread of malaria are proposed and analyzed. Effects of natural as well as human population density related environmental and ecological factors, which are conductive to the survival and growth of mosquito population, are considered. It is shown in both the cases that as the parameters governing environmental and ecological factors increase, the spread of malaria increases. It is also found that due to immigration, this infectious disease becomes more endemic.

scholarly journals A Method for the Estimation of Finely-Grained Temporal Spatial Human Population Density Distributions Based on Cell Phone Call Detail Records

2020 ◽  
Vol 12 (16) ◽  
pp. 2572 ◽  
Author(s):  
Guangyuan Zhang ◽  
Xiaoping Rui ◽  
Stefan Poslad ◽  
Xianfeng Song ◽  
Yonglei Fan ◽  
...  
Keyword(s):  
Population Density ◽  
Density Distribution ◽  
Temporal Resolution ◽  
Human Population ◽  
Population Distribution ◽  
Ground Truth ◽  
Mobile Phone Data ◽  
Ground Truth Data ◽  
Density Distributions ◽  
Population Distributions

Estimating and mapping population distributions dynamically at a city-wide spatial scale, including those covering suburban areas, has profound, practical, applications such as urban and transportation planning, public safety warning, disaster impact assessment and epidemiological modelling, which benefits governments, merchants and citizens. More recently, call detail record (CDR) of mobile phone data has been used to estimate human population distributions. However, there is a key challenge that the accuracy of such a method is difficult to validate because there is no ground truth data for the dynamic population density distribution in time scales such as hourly. In this study, we present a simple and accurate method to generate more finely grained temporal-spatial population density distributions based upon CDR data. We designed an experiment to test our method based upon the use of a deep convolutional generative adversarial network (DCGAN). In this experiment, the highest spatial resolution of every grid cell is 125125 square metre, while the temporal resolution can vary from minutes to hours with varying accuracy. To demonstrate our method, we present an application of how to map the estimated population density distribution dynamically for CDR big data from Beijing, choosing a half hour as the temporal resolution. Finally, in order to cross-check previous studies that claim the population distribution at nighttime (from 8 p.m. to 8 a.m. on the next day) mapped by Beijing census data are similar to the ground truth data, we estimated the baseline distribution, first, based upon records in CDRs. Second, we estimate a baseline distribution based upon Global Navigation Satellite System (GNSS) data. The results also show the Root Mean Square Error (RMSE) is about 5000 while the two baseline distributions mentioned above have an RMSE of over 13,500. Our estimation method provides a fast and simple process to map people’s actual density distributions at a more finely grained, i.e., hourly, temporal resolution.

scholarly journals Mountain definitions and their consequences

Alpine Botany ◽  
2021 ◽  
Author(s):  
Christian Körner ◽  
Davnah Urbach ◽  
Jens Paulsen
Keyword(s):  
Species Richness ◽  
Population Density ◽  
Climatic Change ◽  
Plant Species ◽  
Human Population ◽  
Short Communication ◽  
Plant Species Richness ◽  
Mountainous Terrain ◽  
Human Population Density

AbstractMountains are rugged structures in the landscape that are difficult to delineate. Given that they host an overproportional fraction of biodiversity of high ecological and conservational value, conventions on what is mountainous and what not are in need. This short communication aims at explaining the differences among various popular mountain definitions. Defining mountainous terrain is key for global assessments of plant species richness in mountains and their likely responses to climatic change, as well as for assessing the human population density in and around mountainous terrain.

scholarly journals Bird and mammal conservation in Gaoligongshan Region and Jingdong County, Yunnan, China: patterns of species richness and nature reserves

Oryx ◽  
2000 ◽  
Vol 34 (4) ◽  
pp. 275-286 ◽  
Author(s):  
Daoying Lan ◽  
Robin Dunbar
Keyword(s):  
Species Richness ◽  
Population Density ◽  
Human Population ◽  
Yunnan Province ◽  
Nature Reserve ◽  
Present Situation ◽  
Primary Forest ◽  
Mammal Conservation ◽  
Latitudinal Patterns ◽  
Conservation Of Biodiversity

AbstractElevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest—especially primary forest—destruction and degradation in the low-lying areas.

Parasite infection and host dynamics in a naturally fluctuating rodent population

2012 ◽  
Vol 90 (9) ◽  
pp. 1149-1160 ◽  
Author(s):  
J.C. Winternitz ◽  
M.J. Yabsley ◽  
S.M. Altizer
Keyword(s):  
Population Density ◽  
Experimental Studies ◽  
Host Density ◽  
Positive Association ◽  
Population Cycles ◽  
Host Population ◽  
Reproductive Status ◽  
Vole Cycles ◽  
Host Infection ◽  
The Impact

Parasites can both influence and be affected by host population dynamics, and a growing number of case studies support a role for parasites in causing or amplifying host population cycles. In this study, we examined individual and population predictors of gastrointestinal parasitism on wild cyclic montane voles ( Microtus montanus (Peale, 1848)) to determine if evidence was consistent with theory implicating parasites in population cycles. We sampled three sites in central Colorado for the duration of a multiannual cycle and recorded the prevalence and intensity of directly transmitted Eimeria Schneider, 1875 and indirectly transmitted cestodes from a total of 267 voles. We found significant associations between host infection status, individual traits (sex, age, and reproductive status) and population variables (site, trapping period, and population density), including a positive association between host density and cestode prevalence, and a negative association between host density and Eimeria prevalence. Both cestode and Eimeria intensity correlated positively with host age, reproductive status, and population density, but neither parasite was associated with poorer host condition. Our findings suggest that parasites are common in this natural host, but determining their potential to influence montane vole cycles requires future experimental studies and long-term monitoring to determine the fitness consequences of infection and the impact of parasite removal on host dynamics.

scholarly journals Human population density correlates with phylogenetic diversity and plant vulnerability in southern Africa

2013 ◽  
Vol 86 ◽  
pp. 166 ◽  
Author(s):  
O. Maurin ◽  
T.J. Davies ◽  
K. Yessoufou ◽  
B.H. Daru ◽  
B.S. Bezeng ◽  
...  
Keyword(s):  
Population Density ◽  
Southern Africa ◽  
Human Population ◽  
Phylogenetic Diversity ◽  
Human Population Density

scholarly journals Reptile diversity of Sinos River Basin

2018 ◽  
Vol 18 (3) ◽  
Author(s):  
Camila Fernanda Moser ◽  
Fernanda Rodrigues de Avila ◽  
Roberto Baptista de Oliveira ◽  
Juliano Morales de Oliveira ◽  
Márcio Borges-Martins ◽  
...  
Keyword(s):  
Population Density ◽  
River Basin ◽  
Human Population ◽  
Urban Region ◽  
Research Centers ◽  
Human Population Density ◽  
In The Wild ◽  
Medical Importance ◽  
Scientific Collections

Abstract This work aimed to catalog the species of reptiles of the Sinos River Basin based on records from scientific collections and data collected in the field. We recorded 65 species, including 46 snakes, nine lizards, five turtles, four amphisbaenians and one caiman. Snakes composed most of the recorded specimens (91.3%), and the three most representative are venomous and of medical importance. The most urban region of the basin (Lowland) has the highest number of records. This fact may be a reflection of the high human population density in this region, which would have favored the encounter of specimens and their sending to scientific collections and research centers. It is worth highlighting that most species with few specimens in the collections are also rarely observed in the wild, such as Clelia hussani and Urostrophus vautieri. This observation makes it feasible that these populations are small or that they are declining.

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