THE DYNAMICS OF LARCH SAWFLY (HYMENOPTERA: TENTHREDINIDAE) POPULATIONS IN SOUTHEASTERN MANITOBA

1976 ◽  
Vol 108 (7) ◽  
pp. 701-730 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Population Dynamics ◽  
Simple Model ◽  
Density Dependence ◽  
Principal Component ◽  
Population Trends ◽  
Foreseeable Future ◽  
Factors Affecting ◽  
Principal Component Analyses ◽  
Larch Sawfly ◽  
The Impact

AbstractLife-table study plots were established in southeastern Manitoba to study the population dynamics of the larch sawfly for the 1956 to 1972 generations and to evaluate the impact of two recently introduced parasites.Abbreviated life tables were used to calculate k-values, expressions of mortality during the different stages due to various factors. Graphical and principal component analyses of the k-values showed that mortality during the cocoon and adult stages (k5) largely determined population trends. None of the factors affecting populations before the introduction of the parasite Olesicampe benefactor Hinz was density-dependent. However, a form of density dependence appeared to exist for O. benefactor and for its hyperparasite Mesochorus dimidiatus Holmgren. The area of discovery for both species decreased rapidly as the density of the female parasites increased.A simple model confirmed that k5 was largely responsible for determining population trends. A second model utilizing the relationships between areas of discovery and adult female densities for O. benefactor and M. dimidiatus provided reasonable approximations to observed values for numbers of sawfly eggs, and numbers of adults, rates of attack, and attacks per female for both species of parasites.Twenty sets of 50 pairs of randomly generated values of k5 were used as simulated input in the second model. None of the values for simulated egg populations of the larch sawfly reached outbreak proportions when O. benefactor and M. dimidiatus were present, but most exceeded these levels in their absence. Larch sawfly populations in southeastern Manitoba should be controlled by O. benefactor in the foreseeable future.

The Impact of Financial Inclusion on Poverty Reduction

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Huong Thi Thanh Tran ◽  
Ha Thi Thu Le
Keyword(s):  
Poverty Reduction ◽  
Negative Impact ◽  
Positive Impact ◽  
Trade Openness ◽  
Principal Component ◽  
Financial Inclusion ◽  
Factors Affecting ◽  
Global Issue ◽  
Negative Effect ◽  
The Impact

Abstract Poverty is a global issue and a lot of attention and efforts of the international community have been made to deal with this problem. Especially in the context of the COVID-19 pandemic, when a part of the population could fall into poverty due to rising unemployment and income deduction, identifying the factors affecting poverty becomes particularly important. Financial inclusion has been recognized as one important factor affecting poverty reduction. This research is conducted to investigate the impact of financial inclusion and other control variables on poverty reduction. The study employs Principal Component Analysis (PCA) to build a financial inclusion index. Using 2SLS and the GMM regressions for a panel data of 29 European countries during the period from 2011 to 2017, the results show that financial inclusion has a negative impact on poverty at all three poverty lines of USD1.9, 3.2, and 5.5 per day. The proportion of the population aged 15–64 and the ratio of service employment to the total number of employment also have a negative effect on all three levels of POV1.9, POV3.2, and POV5.5. In contrast, GDP per capita, trade openness and the proportion of the population aged from 25 with at least secondary school education have a positive impact on poverty at three levels of poverty. The results confirm that financial inclusion plays an important role in reducing poverty. The study provides a number of recommendations to governments to promote financial inclusion and reduce poverty in the countries.

scholarly journals Biotic and Abiotic Factors Affecting the Population Dynamics of Ceratium hirundinella, Peridinium cinctum, and Peridiniopsis elpatiewskyi

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 137
Author(s):  
Behrouz Zarei Darki ◽  
Alexandr F. Krakhmalnyi
Keyword(s):  
Population Dynamics ◽  
Abiotic Factors ◽  
Sulfate Ion ◽  
Temperature Conductivity ◽  
Factors Affecting ◽  
Ceratium Hirundinella ◽  
Peridinium Cinctum ◽  
Abiotic And Biotic Factors ◽  
The Impact

The present research was conducted to assess the impact of abiotic and biotic factors on the growth of freshwater dinoflagellates such as Ceratium hirundinella, Peridinium cinctum, and Peridiniopsis elpatiewskyi, which reduce the quality of drinking water in the Zayandeh Rud Reservoir. To this end, 152 algal and zoological samples were collected from the reservoir located in the Central part of Iran in January, April, July, and October 2011. Abiotic factors such as pH, temperature, conductivity, transparency, dissolved oxygen, and nutrient concentration of the water were measured in all study stations. The results showed that the population dynamics of dinoflagellates in the Zayandeh Rud Reservoir was different depending on season, station, and depth. The findings proved that C. hirundinella was one of the dominant autumn planktons in the highest biovolume in the Zayandeh Rud Reservoir. While P. elpatiewskyi was present in the reservoir throughout a year with biovolume peak in summer. Accompanying bloom of P. elpatiewskyi and C. hirundinella, P. cinctum also grew in well-heated summer and autumn waters. It was further found that Ceratium density was positively correlated with sulfate ion concentrations, while the growth of P. cinctum and P. elpatiewskyi were associated, first and foremost, with NO2− and Mn.

scholarly journals Spatial memory shapes density dependence in population dynamics

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171411 ◽  
Author(s):  
Louise Riotte-Lambert ◽  
Simon Benhamou ◽  
Christophe Bonenfant ◽  
Simon Chamaillé-Jammes
Keyword(s):  
Population Dynamics ◽  
Spatial Memory ◽  
Density Dependence ◽  
Cognitive Abilities ◽  
Population Level ◽  
Renewable Resource ◽  
Foraging Efficiency ◽  
Movement Model ◽  
Individual Level ◽  
The Impact

Most population dynamics studies assume that individuals use space uniformly, and thus mix well spatially. In numerous species, however, individuals do not move randomly, but use spatial memory to visit renewable resource patches repeatedly. To understand the extent to which memory-based foraging movement may affect density-dependent population dynamics through its impact on competition, we developed a spatially explicit, individual-based movement model where reproduction and death are functions of foraging efficiency. We compared the dynamics of populations of with- and without-memory individuals. We showed that memory-based movement leads to a higher population size at equilibrium, to a higher depletion of the environment, to a marked discrepancy between the global (i.e. measured at the population level) and local (i.e. measured at the individual level) intensities of competition, and to a nonlinear density dependence. These results call for a deeper investigation of the impact of individual movement strategies and cognitive abilities on population dynamics.

scholarly journals Lifestyle of Generation Y in Thailand’s Rural Society

2021 ◽  
pp. 63-69
Author(s):  
Kanokwara Phuangprayong ◽  
◽  
Sanit Noonin
Keyword(s):  
Generation Y ◽  
Rural Areas ◽  
Rural Society ◽  
Principal Component ◽  
Study Data ◽  
Factors Affecting ◽  
Modern Development ◽  
Service Areas ◽  
Level Of Significance ◽  
The Impact

The research aimed to analyze the component of lifestyle of generation Y and explore factors affecting the lifestyle of generation Y in Thailand’s rural society. Data were collected by questionnaire from 393 samples who are generation Y (18 to 37 years old in 2018) and lived in rural areas of Thailand, that were the communities in service areas of the graduate volunteer students, Class 49, Thammasat University. In this study, data were analyzed by using descriptive statistics, factor analysis by employing principal component analysis and multiple regression analysis (Enter Method). The results showed that in each lifestyle; activities, interests and opinions of generation Y can be classified into 9 groups and factors affecting the lifestyle of generation Y in Thailand’s modern rural society were age, marital status, education level, income adequacy, the membership of a group or organization in the community, affected by state policy, the impact of modern development and using social media. These variables could predict the lifestyle of generation Y in Thailand’s modern rural society at 31.5% at the .05 level of significance.

The Impact of Density Dependence, Sociopolitical Legitimation and Competitive Intensity on Self-Help/Mutual-Aid Formation

2008 ◽  
Vol 29 (1) ◽  
pp. 79-101 ◽  
Author(s):  
Matthew E. Archibald
Keyword(s):  
Density Dependence ◽  
Institutional Factors ◽  
Mutual Aid ◽  
Competitive Intensity ◽  
Factors Affecting ◽  
Health Movement ◽  
Self Help ◽  
Beneficial Impact ◽  
Movement Organizations ◽  
The Impact

Density-dependent and density-independent legitimation and competition are used to explain the evolution of self-help/mutual-aid (1955—2000), a long-lived population of health movement organizations. While previous research suggests the importance of both kinds of measures, this paper shows that better specification of density-independent sociopolitical legitimation and competitive intensity improves understanding of organizational and institutional factors affecting organizational formation. Sociopolitical legitimation, for instance, has a beneficial impact on self-help/mutual-aid formation, but later depresses founding rates because identity enclosure hinders new entries. Implications for further studies of identity, legitimation and competition are discussed.

Rainfall Insurance Scheme for Coffee in Karnataka: Exploring the Indicators of Performance

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Minnappa Prabhu ◽  
Gowdara Kotreshwar
Keyword(s):  
Factor Analysis ◽  
Principal Component ◽  
Index Insurance ◽  
Insurance Scheme ◽  
Basis Risk ◽  
Factors Affecting ◽  
Rainfall Index ◽  
Several Variables ◽  
Risk Protection ◽  
The Impact

The purpose of this paper is to explore the factors influencing the design and the development of Rainfall Insurance scheme for coffee plantation. The method used is qualitative design with some quantitative elements. Data were collected through a field survey of 390 growers who have purchased the rainfall insence contracts. Factor Analysis, Principal Component Analysis, Kaiser-Meyer-Olkin, Bartletts Test of Sphericity, and Kaisers Varimax rotation were used to measure the sample adequacy and to extract the factors affecting the rainfall index insurance. In this study several variables impacting rainfall index insurance have been identified for factor analysis. On the basis of Varimax with Kaiser Normalization, eight factors have emerged. These include: Rainfall Risk, Trigger Rainfall, Sum Insured, Rainfall Risk Protection, Basis Risk, Claim Settlement, Payout, and Premium. The study highlights the impact of factors on the performance of RISC. The findings reveal the need for redesign and recasting existing Rainfall Insurance Scheme for efficient risk management in coffee industry. The findings of study reinforce the need for better understanding of the factors impacting Rainfall Insurance Scheme for coffee performance. The study is useful in generating inputs for redesigning Rainfall Insurance Scheme for coffee by insurers.

Is technological change a devourer of jobs?

2017 ◽  
pp. 111-140 ◽  
Author(s):  
R. Kapeliushnikov
Keyword(s):  
Technological Change ◽  
Critical Analysis ◽  
New Technologies ◽  
Employment Growth ◽  
Foreseeable Future ◽  
Employment Effects ◽  
Technological Unemployment ◽  
Micro Level ◽  
Task Sets ◽  
The Impact

The paper provides a critical analysis of the idea of technological unemployment. The overview of the existing literature on the employment effects of technological change shows that on the micro-level there exists strong and positive relationship between innovations and employment growth in firms; on the sectoral level this correlation becomes ambiguous; on the macro-level the impact of new technologies seems to be positive or neutral. This implies that fears of explosive growth of technological unemployment in the foreseeable future are exaggerated. Our analysis further suggests that new technologies affect mostly the structure of employment rather than its level. Additionally we argue that automation and digitalisation would change mostly task sets within particular occupations rather than distribution of workers by occupations.

The Impact of Shariah Governance and Corporate Governance on the Risk Management Practices: Evidence from Local and Foreign Islamic Banks in Malaysia

2018 ◽  
Vol 15 (2) ◽  
pp. 1-20
Author(s):  
Sabri Embi ◽  
Zurina Shafii
Keyword(s):  
Risk Management ◽  
Corporate Governance ◽  
Management Practices ◽  
Principal Component ◽  
T Test ◽  
The Body ◽  
Primary Data ◽  
Islamic Banks ◽  
Shariah Governance ◽  
The Impact

The purpose of this study is to examine the impact of Shariah governance and corporate governance (CG) on the risk management practices (RMPs) of local Islamic banks and foreign Islamic banks operating in Malaysia. The Shariah governance comprises the Shariah review (SR) and Shariah audit (SA) variables. The study also evaluates the level of RMPs, CG, SR, and SA between these two type of banks. With the aid of SPSS version 20, the items for RMPs, CG, SR, and SA were subjected to principal component analysis (PCA). From the PCA, one component or factor was extracted each for the CG, SR, and RMPs while another two factors were extracted for the SA. Primary data was collected using a self-administered survey questionnaire. The questionnaire covers four aspects ; CG, SR, SA, and RMPs. The data received from the 300 usable questionnaires were subjected to correlation and regression analyses as well as an independent t-test. The result of correlation analysis shows that all the four variables have large positive correlations with each other indicating a strong and significant relationship between them. From the regression analysis undertaken, CG, SR, and SA together explained 52.3 percent of the RMPs and CG emerged as the most influential variable that impacts the RMPs. The independent t-test carried out shows that there were significant differences in the CG and SA between the local and foreign Islamic banks. However, there were no significant differences between the two types of the bank in relation to SR and RMPs. The study has contributed to the body of knowledge and is beneficial to academicians, industry players, regulators, and other stakeholders.

DAMPAK KEBIJAKAN FISKAL TERHADAP KINERJA SEKTOR PERTANIAN DI SULAWESI TENGGARA

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
La Ode Jabuddin ◽  
Ayub M Padangaran ◽  
Azhar Bafadal Bafadal
Keyword(s):  
Fiscal Policy ◽  
Interest Rates ◽  
Agricultural Sector ◽  
Simultaneous Equations ◽  
Poor People ◽  
Land Area ◽  
Factors Affecting ◽  
Historical Simulation ◽  
The Impact ◽  
Direct Expenditure

This study aims to: (1) Knowing the dynamics of fiscal policy and the performance of the agricultural sector, (2) Analyze the factors that influence fiscal policy and the performance                   of the agricultural sector, and (3) Analyzing the impact of fiscal policy on the performance of the agricultural sector. The data used in this study were pooled 2005-2013 data in the aggregate. Econometric model the impact of fiscal policy on the performance of the agricultural sector is built in the form of simultaneous equations, consisting of 7 equations with 25 total variables in the model, 7 endogenous variables, 12 exogenous variables, and 6 variables lag. The model is estimated by 2SLS method SYSLIN procedures and historical simulation with SIMNLIN procedure.The results showed that: (1) The development of fiscal policy in Southeast Sulawesi from year to year tends to increase, (2) The performance of the agricultural sector from the aspect of GDP has decreased, from the aspect of labor is still consistent, in terms of investment to grow positively, and assign roles which means to decrease the number of poor people, (3) factors affecting fiscal policy is local revenues, equalization funds, other revenues, as well as the lag fiscal policy, (4) the factors that affect the performance of the agricultural sector from the aspect GDP is labor, direct expenditure and GDP lag; from the aspect of labor is the total labor force, investment, land area, direct expenditure, as well as the lag of labor; from the aspect of investment is influenced by GDP per capita, land area, interest rates and investment lag; as well as from the aspect of poor people, are affected by population, investments, direct expenditure and poverty lag, (5). Fiscal policy impact on the agricultural sector GDP increase, a decrease in the number of poor, declining agricultural laborers, and a decrease in the amount of investment in the agricultural sector.Keywords: Fiscal policy, the performance of the agricultural sector, the simultaneous equations

Long-term population dynamics of the red deer and European roe deer at the protected and not-protected areas in Mountain Crimea

2017 ◽  
Vol 7 (4) ◽  
pp. 65-72
Author(s):  
V. N. Shmagol' ◽  
V. L. Yarysh ◽  
S. P. Ivanov ◽  
V. I. Maltsev
Keyword(s):  
Population Dynamics ◽  
Protected Areas ◽  
Red Deer ◽  
Nature Reserve ◽  
Roe Deer ◽  
Precipitation Amount ◽  
Annual Precipitation ◽  
Population Number ◽  
The Impact

<p>The long-term population dynamics of the red deer (<em>Cervus elaphus</em> L.) and European roe deer (<em>Capreolus</em> <em>capreolus</em> L.) at the mountain and forest zone of Crimea during 1980-2017 is presented. Fluctuations in numbers of both species are cyclical and partly synchronous. Period of oscillations in the population of red deer is about 25 years, the average duration of the oscillation period of number of roe deer is 12.3 years. During the fluctuations in the number the increasing and fall in population number of the red deer had been as 26-47 %, and roe deer – as 22-34 %. Basing on the dada obtained we have assumed that together with large-scale cycles of fluctuations in population number of both red deer and roe deer the short cycles of fluctuations in the number of these species with period from 3.5 to 7.5 years take place. Significant differences of the parameters of cyclical fluctuations in the number of roe deer at some sites of the Mountainous Crimea: breaches of synchronicity, as well as significant differences in the duration of cycles are revealed. The greatest deviations from the average values of parameters of long-term dynamics of the number of roe deer in Crimea are noted for groups of this species at two protected areas. At the Crimean Nature Reserve the cycle time of fluctuations of the numbers of roe deer was 18 years. At the Karadag Nature Reserve since 1976 we can see an exponential growth in number of roe deer that is continued up to the present time. By 2016 the number of roe deer reached 750 individuals at a density of 437 animals per 1 thousand ha. Peculiarity of dynamics of number of roe deer at some sites proves the existence in the mountain forest of Crimea several relatively isolated groups of deer. We assumed that "island" location of the Crimean populations of red deer and European roe deer, their relatively little number and influence of permanent extreme factors of both natural and anthropogenic origination have contributed to a mechanism of survival of these populations. The elements of such a mechanism include the following features of long-term dynamics of the population: the reduction in the period of cyclic population fluctuations, while maintaining their amplitude and the appearance of additional small cycles, providing more flexible response of the population to the impact of both negative and positive environmental factors. From the totality of the weather conditions for the Crimean population of roe deer the recurring periods of increases and downs in the annual precipitation amount may have relevance. There was a trend of increase in the roe deer population during periods of increasing annual precipitation.</p>

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