Parasite aggregations in host populations using a reformulated negative binomial model

2004 ◽  
Vol 78 (1) ◽  
pp. 57-61 ◽  
Author(s):  
P. Pal ◽  
J.W. Lewis
Keyword(s):  
Negative Binomial ◽  
Host Population ◽  
Distribution Model ◽  
Cumulative Probability ◽  
Heligmosomoides Polygyrus ◽  
Specific Level ◽  
Parasite Aggregation ◽  
High Degree ◽  
Binomial Function

AbstractThe negative binomial distribution model is reformulated and used to demarcate a host population at a specific level of infection by defining an attribute spanning a range of parasite aggregations. The upper limit of the range specifies the boundary for the classification of the host population and provides a technique to determine the cumulative probability at any level of parasite infection to a high degree of accuracy. This approach also leads to the evaluation of thekparameter, i.e. an inverse measure of dispersion of parasite aggregation, for each fraction of the host population with a discrete level of infection. The basic mathematical premise of the negative binomial function is unaltered in developing this reformulation which was applied to data on the distribution of the trichostrongylid nematodeHeligmosomoides polygyrusin populations of the field mouse,Apodemus sylvaticus.

scholarly journals Heterogeneity in transmission parameters of hookworm infection within the baseline data from the TUMIKIA study in Kenya

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
James E. Truscott ◽  
Alison K. Ower ◽  
Marleen Werkman ◽  
Katherine Halliday ◽  
William E. Oswald ◽  
...  
Keyword(s):  
Negative Binomial ◽  
Positive Association ◽  
Monitoring And Evaluation ◽  
Host Population ◽  
Transmission Model ◽  
High Coverage ◽  
Study Region ◽  
Transmission Parameters ◽  
Parasite Aggregation ◽  
The Impact

Abstract Background As many countries with endemic soil-transmitted helminth (STH) burdens achieve high coverage levels of mass drug administration (MDA) to treat school-aged and pre-school-aged children, understanding the detailed effects of MDA on the epidemiology of STH infections is desirable in formulating future policies for morbidity and/or transmission control. Prevalence and mean intensity of infection are characterized by heterogeneity across a region, leading to uncertainty in the impact of MDA strategies. In this paper, we analyze this heterogeneity in terms of factors that govern the transmission dynamics of the parasite in the host population. Results Using data from the TUMIKIA study in Kenya (cluster STH prevalence range at baseline: 0–63%), we estimated these parameters and their variability across 120 population clusters in the study region, using a simple parasite transmission model and Gibbs-sampling Monte Carlo Markov chain techniques. We observed great heterogeneity in R0 values, with estimates ranging from 1.23 to 3.27, while k-values (which vary inversely with the degree of parasite aggregation within the human host population) range from 0.007 to 0.29 in a positive association with increasing prevalence. The main finding of this study is the increasing trend for greater parasite aggregation as prevalence declines to low levels, reflected in the low values of the negative binomial parameter k in clusters with low hookworm prevalence. Localized climatic and socioeconomic factors are investigated as potential drivers of these observed epidemiological patterns. Conclusions Our results show that lower prevalence is associated with higher degrees of aggregation and hence prevalence alone is not a good indicator of transmission intensity. As a consequence, approaches to MDA and monitoring and evaluation of community infection status may need to be adapted as transmission elimination is aimed for by targeted treatment approaches.

Applying an aggregative dispersive dichotomy (ADD) model to parasitic infections in host populations

2008 ◽  
Vol 82 (3) ◽  
pp. 187-192 ◽  
Author(s):  
P. Pal ◽  
M.A. Abu-Madi ◽  
J.W. Lewis
Keyword(s):  
Negative Binomial ◽  
Parasitic Infection ◽  
Simulated Data ◽  
Wood Mouse ◽  
Threshold Level ◽  
Host Community ◽  
Parasitic Infections ◽  
Cumulative Probability ◽  
Scale Free ◽  
Parasite Aggregation

AbstractAn aggregative dispersive dichotomy (ADD) model is presented to describe the distribution of parasites in host populations. The ADD model is a mathematical construct which provides two complementary measures extracted from a reformulated negative binomial (NBD) and an inequality model, which combine to capture observed patterns of a parasitic infection. The dispersion element is modelled using the NBD with the threshold set at a parasite level above zero. By applying binomial dichotomy, the host community is divided into two sub-populations, one including hosts harbouring parasites up to the threshold and the other with parasites above the threshold level. Thekparameter, derived from the NBD, provides a cumulative probability. However,kis relatively insensitive to variations in the degree of aggregation, a known feature of the NBD model. The aggregation of parasites above the threshold in the host sub-population is evaluated by using an inequality model which is indexed by a scale-free parameter δ(δ ≥ 1) and provides an accurate measure of parasite aggregation. Applications of this model are made from field and simulated data in wood mouse populations infected with the trichostrongylid nematodeHeligmosomoides polygyrusfrom a woodland site in Surrey.

The Degree Of Understanding Of Zakat On Profession/Income In Jepara Regency

2018 ◽  
Vol 16 (2) ◽  
pp. 138
Author(s):  
Aan Zainul Anwar ◽  
Miftah Arifin
Keyword(s):  
Qualitative Method ◽  
Civil Servants ◽  
Distribution Model ◽  
Professional Work ◽  
Government Officials ◽  
Military Police ◽  
High Degree

This study aimed to determine the degree of understanding of zakat on profession/income and the characteristics of the community distribution model as an effective collection model for zakat institutions. This study used a qualitative method with 68 respondents from various professional work backgrounds including civil servants, teachers, employees, military, police, and government officials. The results of this study were that Jepara people have a high degree of understanding about zakat but have not been fully able to calculate nishab of zakat especially zakat on profession/income. Therefore, not all people who are obliged to pay zakat on professionand the distribution of zakat on professionis still directly to mustahiq.Keywords: Zakat on Profession/Income; Understanding of Zakat; Zakat; Alms 

scholarly journals Identification of the degree of impact of dams on the hydrologic regime of semi-arid rivers: an evaluation of the DHRAM method

RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Naiah Caroline Rodrigues de Souza ◽  
◽  
Andrea Sousa Fontes ◽  
Lafayette Dantas da Luz ◽  
Sandra Maria Conceição Pinheiro ◽  
...  
Keyword(s):  
Hydrological Regime ◽  
Flow Regulation ◽  
Hydrologic Regime ◽  
Local Conditions ◽  
Operating Rules ◽  
Hydrologic Variability ◽  
High Degree ◽  
The Impact ◽  
Semi Arid

ABSTRACT The flow regulation that results from the implantation of dams causes consequences to the river ecosystems due to the modification on the characteristics of the hydrologic regime. The investigation of these changes become relevant, mainly in semi-arid regions where there is a great amount of these hydraulic structures and lack of such analyzes. Considering the above, this paper aims to evaluate the Dundee Hydrological Regime Alteration Method (DHRAM) through the classification of the degree of impact of dams located on rivers Itapicuru, Paraguaçu and their tributaries, verifying the adequacy of its use to represent the semi-arid hydrologic regime. Thereby, the DHRAM was applied in three versions: considering the thresholds that define the scores to classify the degree of impact in its original set (accordingly to Black et al. (2005)); with the adjustment of those thresholds to local conditions; and, with the regrouping of variables and adjustment of thresholds. The results showed that the method in its original set is applicable to semi-arid rivers, however it tends to be very restrictive against the high natural hydrologic variability characteristic of these rivers, and it ends up pointing to a high degree of alteration for dams that are known for not causing a very siginifcant flow regulation. The DHRAM with the regrouping of variables and the adjustment of thresholds presented the classification that approached the most to the known characteristics of the studied dams, being useful for the evaluation of the impact of dams still in project, and also to guide the adoption of operating rules that minimize the most significant hydrologic alterations that are identified.

Integrating Reliability Analysis in Life Cycle Cost Estimation of Heat Exchanger and Pump

2014 ◽  
Vol 903 ◽  
pp. 408-413 ◽  
Author(s):  
FRESELAM Mulubrhan ◽  
Ainul Akmar Mokhtar ◽  
Masdi Muhammad
Keyword(s):  
Life Cycle ◽  
Heat Exchanger ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Distribution Model ◽  
Maintenance Cost ◽  
Published Data ◽  
Acquisition Costs ◽  
Maintenance Policies ◽  
High Degree

This paper presents a mathematical model to estimate the life cycle cost (LCC) of heat exchanger and pump. Maintenance cost, down time cost and acquisition costs are calculated. The main uncertainty in calculating these costs are prediction of number of failure and cumulative down time. Number of failure is determined using failure and repair time density function. According to the characteristic that the cumulative failure probability observed, a Weibull distribution model is used. The scale and shape parameters of the Weibull are extracted from the published data. The results of the study show that 71.3% loss in the reliability of heat exchanger and 34.2% reliability loss in pump could lead to 66.2 % increment of the total cost. The reliability of the system decreases because of number of failures will increase each year, and this failure leads to unavailability of the system.Therefore in order to achieve higher system effectiveness and reduce the total LCC, the reliability of the systems need to be increased through proper maintenance policies and strategies. The results of the study could assist the managers to make decision with high degree of accuracy.

Evaluational Reactions to Erotic Literature

1965 ◽  
Vol 16 (3) ◽  
pp. 985-994 ◽  
Author(s):  
Leon A. Jakobovits
Keyword(s):  
Short Stories ◽  
Hard Core ◽  
Cumulative Effect ◽  
Sampling Bias ◽  
Male And Female ◽  
Warm Up ◽  
Erotic Literature ◽  
High Degree ◽  
Very High

On the basis of analysis of a variety of erotic literature Kronhausen and Kronhausen (1959) have suggested that there seem to be two general types: erotic realism ( ER) and hard-core obscenity ( O). Using three of the distinguishing criteria which were identified (context, exaggeration, and anti-eroticism), 20 short stories were specifically written in such a way that 10 had the characteristics of ER and the others had the characteristics of O. Study I showed a very high degree of agreement between judges in their classification of these stories as either ER or O. Study II revealed that male and female readers react differentially to the two types of stories. Females consistently rate O as more interesting and sexually stimulating than males do, the latter finding ER as more arousing than O. Other evaluational reactions are also described. A “warm-up” cumulative effect with successive reading was found with both sexes. The possibility of sampling bias affecting the data was noted.

scholarly journals On the Cognitive Foundation of Lexical Classification of the Subject World

2020 ◽  
pp. 59-75
Author(s):  
Alexey D. Koshelev ◽  
Keyword(s):  
Human Cognition ◽  
Language Of Thought ◽  
Human Species ◽  
Specific Level ◽  
Human Ability ◽  
The World ◽  
The Subject ◽  
Lexical Classification

The paper presents a language of thought (a set of cognitive units and relations) used to provide non-verbal definitions for the following five concepts: ARMCHAIR, MUG, RAVINE, LAKE, TREE. These definitions make it possible to describe concepts on two levels of specificity. On the first level, a concept is presented as a holistic cognitive unit. On the second, more specific, level, the same concept is viewed as a partitive system, i.e. a hierarchical system of its parts, the latter being smaller concepts into which the original holistic unit is decomposed. A hypothesis is advanced that such structure is inherent to all visible objects. The partitive system is argued to play a major role in human cognition. It, first, provides for an in-depth understanding of the perceived objects through understanding the role of their parts, and, second, underlies the formation of the hierarchy of concepts with respect to their generality. Besides, it can be considered as one of the defining properties of the human species as it accounts for the human ability to purposefully change the world.

scholarly journals Assessment of genetic diversity in Indian Barnyard millet (Echinochloa spp. complex) using morphological and molecular markers

2016 ◽  
Vol 8 (3) ◽  
pp. 1643-1648 ◽  
Author(s):  
M. P. Moharil ◽  
Dipti Gawai ◽  
N. Dikshit ◽  
M.S. Dudhare ◽  
P. V. Jadhav
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Genetic Improvement ◽  
Molecular Diversity ◽  
Genetic Relationships ◽  
Barnyard Millet ◽  
Clear Cut ◽  
Cultivated Species ◽  
High Degree

In the present study, morphological and molecular markers (RAPD primers) were used to analyze the genetic diversity and genetic relationships among 21 accessions of Echinochloa spp. complex comprising the wild and cultivated species collected from Melghat and adjoining regions of Vidarbha, Maharashtra. The availability of diverse genetic resources is a prerequisite for genetic improvement of any crop including barnyard millet. A high degree of molecular diversity among the landraces was detected. Among the 21 genotypes, two major groups (A and B) were formed, at 67.28 % similarity, which clearly encompasses 15 accessions of E. frumentacea and 6 accessions of E. colona. Higher similarity was observed in accessions of E. frumentacea. The accessions IC 597322 and IC 597323 also IC 597302 and IC 597304 showed more than 94% similarity among themselves. The classification of genetic diversity has enabled clear-cut grouping of barnyard millet accessions into two morphological races (E. frumentacea and E. colona).

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