MAJOR FACTORS IN SURVIVAL OF THE IMMATURE STAGES OF FENUSA PUSILLA IN SOUTHWESTERN QUEBEC

1970 ◽  
Vol 102 (8) ◽  
pp. 995-1002 ◽  
Author(s):  
H. H. Cheng ◽  
E. J. LeRoux
Keyword(s):  
Population Dynamics ◽  
Leaf Miner ◽  
Immature Stages ◽  
Key Factors ◽  
Larval Stages ◽  
Fenusa Pusilla ◽  
Two Generations ◽  
Key Factor ◽  
Major Factors ◽  
Old Trees

AbstractIntensive studies on the population dynamics of the birch leaf miner, Fenusa pusilla (Lepeletier), were carried out in two stands of blue birch at the Morgan Arboretum, Macdonald College, Que., from 1964 to 1966. Life tables for nine and two generations, respectively, showed that mortality of the immature stages was lower on 3- to 5-year-old trees than on 9-year-old trees. The analysis of successive age-interval survivals in relation to generation survival revealed that predation during the late larval stages was the key factor in generation survival of the insect on the younger trees. Desiccation of the leaf during the early larval stages along with predation were key factors on the older trees.

Major Factors in Survival of the Immature Stages of Pieris rapae (L.)

1966 ◽  
Vol 98 (6) ◽  
pp. 653-662 ◽  
Author(s):  
D. G. Harcourt
Keyword(s):  
Population Dynamics ◽  
Survival Rate ◽  
Pieris Rapae ◽  
Pupal Stage ◽  
Population Data ◽  
Life Tables ◽  
Immature Stages ◽  
Mortality Factors ◽  
Key Factor ◽  
Major Factors

AbstractDetailed studies on the population dynamics of the imported cabbageworm, Pieris rapae (L.), have been carried out at Merivale, Ontario, since 1959. A method for preparing life tables is described and a mean life table is presented for 18 generations of the species on cabbage. Population data for the preadult period show that there are three age intervals during which extensive mortality may occur: (1) between hatching and the second moult, (2) instars three to five, and (3) during the pupal stage. The analysis of successive age-interval survivals in relation to generation survival showed that the latter is largely determined by the survival rate for (2). Examination of the life tables revealed that a granulosis of the larvae caused by a capsule virus is the key factor in generation survival. Major mortality factors include rainfall and parasites.

BIOLOGY AND IMMATURE STAGES OF LEUCOPIS PIMCOLA AND CHAMAEMYIA POLYSTIGMA (DIPTERA: CHAMAEMYIIDAE)

1973 ◽  
Vol 105 (11) ◽  
pp. 1443-1452 ◽  
Author(s):  
Thomas P. Sluss ◽  
B. A. Foote
Keyword(s):  
Lolium Perenne ◽  
Feeding Habits ◽  
Life Cycles ◽  
Pine Bark ◽  
Larval Feeding ◽  
Immature Stages ◽  
Larval Instars ◽  
Larval Stages ◽  
Rye Grass ◽  
Two Generations

AbstractThe life cycles and larval feeding habits of Leucopis (Neoleucopis) pinicola Malloch and Chamaemyia polystigma Meigen were studied in northeastern Ohio. The larval stages of L. pinicola are predators of the pine bark aphid, Pineus strobi (Hartig) (Homoptera: Adelgidae). Probably there are only two generations a year, and overwintering occurs as mature larvae or pupae that are in diapause. Larvae of C. polystigma prey on the blue grass mealybug, Heterococcus nudus Green (Homoptera: Pseudococcidae), that infests perennial rye grass, Lolium perenne L. This species has three generations a year and overwinters as diapausing mature larvae and pupae.The eggs, three larval instars, and puparia of both species are described and illustrated.

scholarly journals Optimize Design of Run-Flat Tires by Simulation and Experimental Research

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 474
Author(s):  
Huaqiao Liu ◽  
Yiren Pan ◽  
Huiguang Bian ◽  
Chuansheng Wang
Keyword(s):  
Stress Distribution ◽  
Energy Loss ◽  
Successful Implementation ◽  
Performance Tests ◽  
Key Factors ◽  
Heat Accumulation ◽  
Factors Affecting ◽  
Structural Rigidity ◽  
Key Factor ◽  
Durability Testing

In this study, the two key factors affecting the thermal performance of the insert rubber and stress distribution on the tire sidewall were analyzed extensively through various performance tests and simulations to promote the development of run-flat tires. Four compounds and two structures of insert rubber were designed to investigate the effects of heat accumulation and stress distribution on durability testing at zero pressure. It was concluded that the rigidity and tensile strength of the compound were negatively correlated with temperature. The deformation was a key factor that affects energy loss, which could not be judged solely by the loss factor. The stress distribution, however, should be considered in order to avoid early damage of the tire caused by stress concentration. On the whole, the careful balance of mechanical strength, energy loss, and structural rigidity was the key to the optimal development of run-flat tires. More importantly, the successful implementation of the simulations in the study provided important and useful guidance for run-flat tire development.

From detente to containment: the emergence of Iran's new Saudi strategy

2021 ◽  
Author(s):  
Hassan Ahmadian ◽  
Payam Mohseni
Keyword(s):  
Decision Making ◽  
Saudi Arabia ◽  
Middle East ◽  
Strategic Decision ◽  
Key Factors ◽  
Peace And Conflict ◽  
Key Factor ◽  
Decision Making Factors ◽  
Containment Strategy ◽  
The Persian Gulf

Abstract Iran's strategy with respect to Saudi Arabia is a key factor in the complex balance of power of the Middle East as the Iranian–Saudi rivalry impacts the dynamics of peace and conflict across the region from Yemen to Syria, Lebanon, Iraq and Bahrain. What is Iranian strategic thinking on Saudi Arabia? And what have been the key factors driving the evolution of Iranian strategy towards the Kingdom? In what marks a substantive shift from its previous detente policy, we argue that Tehran has developed a new containment strategy in response to the perceived threat posed by an increasingly prox-active Saudi Arabia in the post-Arab Spring period. Incorporating rich fieldwork and interviews in the Middle East, this article delineates the theoretical contours of Iranian containment and contextualizes it within the framework of the Persian Gulf security architecture, demonstrating how rational geopolitical decision-making factors based on a containment strategy, rather than the primacy of sectarianism or domestic political orientations, shape Iran's Saudi strategy. Accordingly, the article traces Iranian strategic decision-making towards the Kingdom since the Islamic Revolution of 1979 and examines three cases of Iran's current use of containment against Saudi Arabia in Syria, Yemen and Qatar.

A METHOD FOR REARING THE LARVAL STAGES OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEMENS (LEPIDOPTERA: TORTRICIDAE), FOR PHYSIOLOGICAL STUDIES

1990 ◽  
Vol 122 (6) ◽  
pp. 1271-1272 ◽  
Author(s):  
Hemendra Mulye ◽  
Roger Gordon
Keyword(s):  
Population Dynamics ◽  
North America ◽  
Choristoneura Fumiferana ◽  
Insect Pest ◽  
Spruce Budworm ◽  
Forest Pest ◽  
Forest Insect ◽  
Larval Stages ◽  
Eastern Spruce Budworm ◽  
Physiological Studies

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.

Production and population dynamics of Ampelisca tenuicornis (Amphipoda) with notes on the biology of its parasite Sphaeronella longipes (Copepoda)

1977 ◽  
Vol 57 (4) ◽  
pp. 955-968 ◽  
Author(s):  
Martin Sheader
Keyword(s):  
Population Dynamics ◽  
Generation Time ◽  
Population Studies ◽  
Generation Length ◽  
Two Generations ◽  
The Mediterranean

Ampelisca tenuicornis Lilljeborg, 1855, is a member of a widely distributed genus of benthic tube-dwelling amphipods. Population studies of A. macrocephala Lilljeborg in the Øresund show it to have a generation length of 2 years (Kanneworff, 1965), and A. vadorum Mills off Massachusetts, U.S.A., produces two generations per year (Mills, 1967). A. brevicornis (Costa) in the Mediterranean breeds throughout the year with a generation time of 5–7 months (Kaim-Malka, 1969), but has only one generation per year in Helgoland Bight (Klein, Rachor & Gerlach, 1975).

scholarly journals Key Factors of Sustainability for Smartphones Based on Taiwanese Consumers’ Perceived Values

2018 ◽  
Vol 10 (12) ◽  
pp. 4446 ◽  
Author(s):  
Jui-Che Tu ◽  
Xiu-Yue Zhang ◽  
Sin-Yi Huang
Keyword(s):  
Service Quality ◽  
Purchase Intention ◽  
Perceived Value ◽  
Income Level ◽  
Demographic Variables ◽  
Key Factors ◽  
Significant Difference ◽  
Perceived Values ◽  
Perceived Price ◽  
Key Factor

The rapid growth of smartphones over recent decades has brought a large amount of e-waste as well as an increased carbon footprint. Facing severe environmental issues, sustainable development of smartphones has become a particularly important public concern. The main aim of this study was to clarify the key factor of sustainability for smartphones based on Taiwanese consumers’ perceived values. Apple’s iPhone was taken as an example. First, key factors of perception that smartphone consumers valued the most in terms of sustainable practice were extracted through a factor analysis. Second, demographic differences related to these key factors were investigated through t-test and one-way ANOVA analyses; demographic variables were gender, age, education level, occupation, and income level. The results were as follows: (1) the key factors were “recognition”, “brand advantage”, “service quality”, “usage period”, and “perceived price”; (2) there was a significant difference between genders on the key factors of perceived value (“recognition”, “brand advantage”, and “perceived price”). Specifically, females have higher perceived values of “recognition”, “brand advantage”, and “perceived price” than males; (3) there was a significant effect of income level on the key factor (“perceived price”) of perceived value. Specifically, respondents with an income level of NTD15,001–30,000 had a higher perceived value of “perceived price” than respondents earning NTD30,001–45,000. Among the five key factors, “recognition” and “brand advantage” are primary factors influencing purchase motivation; “recognition”, “brand advantage”, and “service quality” are primary factors that could influence brand loyalty; “perceived price” is the primary factor that affects purchase intention. This study contributes to the green market segmentation of smartphones. The limitations of the study relate to the size and distribution of the samples.

scholarly journals Person - job fi t and the work commitment of IT Personnel

2016 ◽  
Vol 26 (2) ◽  
pp. 218 ◽  
Author(s):  
Therasa C. ◽  
C. Vijayabanu
Keyword(s):  
Regression Analysis ◽  
Principal Component ◽  
Attrition Rate ◽  
P Value ◽  
Work Commitment ◽  
Key Factors ◽  
Coeffi Cients ◽  
Work Autonomy ◽  
Major Factors ◽  
The Impact

Introduction: There have been given a much higher importance to employee commitment and retention since India is experiencing the highest attrition rate globally Economic Times, 2015. Hence, considering the factors of Person-job fi t to interpret the impact towards work commitment is very well essential, especially in the current scenario. Work Commitment is a vital element in any organization which has outstanding impact on productivity and functioning and hence it is very much vital to have a committed workforce which is necessary in this competitive environment and tight labour market. In the same way, there is considerable amount of evidence that if P-J fi t is high then it will have a direct impact on organization commitment also. Person-job fi t is the compatibility between person’s competency and abilities and the requirements of the job Zheng et al.2. If there exists a mismatch between person-job fi t then the consequences might result in poor work commitment, low job satisfaction and extremely lower involvement in the job. Objective: This study analyzed the key factors that contribute to Person- job compatibility among IT workers and also analyzed the relationship and impact of Person- job compatibility towards work commitment. Methods: Exploratory Factor Analysis (EFA) was used to fi lter the key factors initially, followed by a linear regression technique to determine the impact of Person- job compatibility factors in work commitment on a sample of 300 employees. EFA used Principal Component analysis for extraction and Promax for rotation. Finally regression analysis was carried out to predict the work commitment through statistically significant person-job compatibility variables. Results: The impact of person-job compatibility on work commitment was studied through regression analysis and it imply that for every unit increase in HR Policy, a 0.52 (unstandardised coeffi cients) increase in work commitment is predicted and it has been turned out as a most impacting variable to predict work commitment. The coeffi cients for Relationship (B =.330, sig =.000), HR Policies (B =.519, sig =.000), Pay and Benefi ts (B =.386, sig =.000) and Employee Growth (B =.290, sig =.001) were statistically significant, since its p-value is .000 which is smaller than .05. The coeffi cients for Work Autonomy (B =.154, sig = .081) was not statistically signifi cant, since its p-value is 0.081 which is greater than.05. Conclusion: The major factors responsible for creating work commitment among IT employees are Relationship, HR Policies and strategies, Pay and benefi ts, Work autonomy and Employee growth. The most contributing regressors which accounts for creating work commitment are HR policies, Pay and benefi ts, Employee growth and work autonomy.

scholarly journals Why We Go Where We Go: Profiling User Decisions on Choosing POIs

2020 ◽  
Author(s):  
Renjun Hu ◽  
Xinjiang Lu ◽  
Chuanren Liu ◽  
Yanyan Li ◽  
Hao Liu ◽  
...  
Keyword(s):  
Key Factors ◽  
Real World Data ◽  
Decision Factors ◽  
Point Of Interest ◽  
Learning Factor ◽  
Poi Recommendation ◽  
Key Factor ◽  
Selection Of ◽  
Decision Structures

While Point-of-Interest (POI) recommendation has been a popular topic of study for some time, little progress has been made for understanding why and how people make their decisions for the selection of POIs. To this end, in this paper, we propose a user decision profiling framework, named PROUD, which can identify the key factors in people's decisions on choosing POIs. Specifically, we treat each user decision as a set of factors and provide a method for learning factor embeddings. A unique perspective of our approach is to identify key factors, while preserving decision structures seamlessly, via a novel scalar projection maximization objective. Exactly solving the objective is non-trivial due to a sparsity constraint. To address this, our PROUD adopts a self projection attention and an L2 regularized sparse activation to directly estimate the likelihood of each factor to be a key factor. Finally, extensive experiments on real-world data validate the advantage of PROUD in preserving user decision structures. Also, our case study indicates that the identified key decision factors can help us to provide more interpretable recommendations and analyses.

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