DETERMINATION OF PREMATURE LARVAL DROP AND OTHER CAUSES OF LARCH SAWFLY MORTALITY

1967 ◽  
Vol 99 (11) ◽  
pp. 1121-1131 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Adult Emergence ◽  
Large Data ◽  
Curvilinear Relationship ◽  
First Year ◽  
Larval Weight ◽  
Linear Relationships ◽  
Larch Sawfly ◽  
Key Factor ◽  
Causes Of Mortality ◽  
Prolonged Diapause

AbstractFifth-instar larvae of the larch sawfly, Pristiphora erichsonii (Hartig), of different weights, were deprived of food and placed in containers with moist moss. A low percentage of the early fifth-instar larvae were able to spin cocoons, but the percentage rapidly increased to a plateau as the larval weight increased. All but the heaviest larvae suffered appreciable mortality before first-year adult emergence was complete. A curvilinear relationship between larval weight and survival to the adult stage or to larvae in prolonged diapause is evident. The percentage of mature ova in adult females was reduced at the lower larval weights, with corresponding increases in the percentages of near-mature and large immature ova. There were linear relationships between larval weights, adult weights, and numbers of oöcytes. A method for assessing premature larval drop and other causes of mortality under field conditions is described and data for a number of years and plots are presented. Variations in the percentages of unparasitized normal late fifth-instar larvae were large. Data indicate that parasitism by Olesicampe (Holocremnus) sp. nr. nematorum (Tschek) and Bessa harveyi (Townsend) is the most important factor, probably a key factor, contributing to this variation.

DIFFERENCES IN POSTDIAPAUSE DEVELOPMENT AMONG GEOGRAPHICALLY DISTINCT POPULATIONS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1972 ◽  
Vol 104 (8) ◽  
pp. 1307-1312 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Relative Humidity ◽  
Northwest Territories ◽  
Cold Treatment ◽  
Adult Emergence ◽  
Population Differences ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
C 50 ◽  
The Times ◽  
Prolonged Diapause

AbstractDistinct differences were observed in postdiapause development and prolonged diapause of the larch sawfly, Pristiphora erichsonii (Hartig), obtained from the vicinity of Tazin River, Northwest Territories; near Riverton, Manitoba; and near Renovo, Pennsylvania. All populations had been reared under controlled laboratory conditions (21°±0.5 °C, 50±10% relative humidity, and a 15-hr daily photophase) for two or more generations.After 280 days cold treatment at 3°±1 °C, cocoons were dissected and the number of pronymphs and eonymphs was determined. Insects from each population were then reared at 5°, 10°, and 15 °C. Times to adult emergence, duration of individual stages, and numbers remaining in prolonged diapause at each temperature were determined.The most significant differences occurred among populations reared at 5 °C. At this temperature, the times to adult emergence and the duration of individual stages of development and the proportions remaining in prolonged diapause or arrested development, increased from northern to southern latitudes. Less significant population differences were noted at 10° and 15° than at 5 °C.

scholarly journals Genre Knowledge and Writing Development: Results From the Writing Transfer Project

2019 ◽  
Vol 37 (1) ◽  
pp. 69-103 ◽  
Author(s):  
Dana Lynn Driscoll ◽  
Joseph Paszek ◽  
Gwen Gorzelsky ◽  
Carol L. Hayes ◽  
Edmund Jones
Keyword(s):  
General Education ◽  
Institutional Design ◽  
Explanatory Power ◽  
Theoretical Work ◽  
Writing Development ◽  
First Year ◽  
Writing Courses ◽  
Key Factor ◽  
Genre Knowledge ◽  
Audience Awareness

Using a mixed-methods, multi-institutional design of general education writing courses at four institutions, this study examined genre as a key factor for understanding and promoting writing development. It thus aims to provide empirical validation of decades of theoretical work on and qualitative studies of genre and the nature of genre knowledge. While showing that both simplistic and nuanced genre knowledge promote writing development, our findings suggest that nuanced genre knowledge correlates with writing development over the course of a semester. Based on these findings, we propose an expanded view of Tardy’s four genre knowledge components and argue for their explanatory power. We recognize these genre components can be cultivated by using three particular strategies: writing for nonclassroom audiences, using source texts explicitly to join existing disciplinary conversations, and cultivating two types of metacognitive awareness (awareness of the writing strategies used to complete specific tasks and awareness of one’s levels of proficiency in particular types of writing knowledge). Findings can be used to enrich first-year or upper-division writing curricula in the areas of genre knowledge, audience awareness, and source use.

scholarly journals Transformational school leadership as a key factor for teachers’ job attitudes during their first year in the profession

2018 ◽  
Vol 48 (1) ◽  
pp. 106-132 ◽  
Author(s):  
Laura Thomas ◽  
Melissa Tuytens ◽  
Geert Devos ◽  
Geert Kelchtermans ◽  
Ruben Vanderlinde
Keyword(s):  
Transformational Leadership ◽  
Beginning Teachers ◽  
School Leadership ◽  
Self Efficacy ◽  
Job Attitudes ◽  
School Level ◽  
Dropping Out ◽  
First Year ◽  
Collegial Support ◽  
Key Factor

Teacher attrition is a global concern that is particularly prevalent among beginning teachers. Teachers’ intrinsic motivation to teach, affective organisational commitment and job satisfaction are considered job attitudes that stop them from dropping out of the profession. This study explores the interplay between factors at the school level (i.e. transformational leadership of the principal, professional collegial support) and the teacher level (i.e. self-efficacy) influencing these job attitudes. A sample of 292 first-year primary-school teachers participated. The results of the path analysis demonstrated that transformational leadership of the principal is directly related to teachers’ job attitudes in a positive way. Moreover, transformational leadership of the principal is also indirectly related to these attitudes, via both professional collegial support and teachers’ self-efficacy. Implications for the supportive role of the principal in the teachers’ first year in the profession are discussed.

Market orientation and firm performance: can there be too much of a good thing?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vivien Jancenelle ◽  
Susan F. Storrud-Barnes ◽  
Dominic Buccieri
Keyword(s):  
Firm Performance ◽  
Market Orientation ◽  
Past Research ◽  
Good Thing ◽  
Annual Reports ◽  
Curvilinear Relationship ◽  
Computer Assisted ◽  
Content Type ◽  
Trade Offs ◽  
Linear Relationships

PurposePast research has generally purported that market orientation (MO) leads to superior firm performance, despite emerging evidence suggesting that the highest levels of MO are not always rewarded. Drawing on resource-based view and MO literature, the authors posit that too much MO may be as detrimental as too little for firms seeking to achieve better performance, and that moderate MO capabilities may be the most beneficial. Furthermore, the authors propose and test for organizational confidence as a first potential moderator of the MO-performance inverted U-shaped link.Design/methodology/approachThe authors use Computer-Assisted-Text-Analysis (CATA) methodology assess constructs from annual reports matched with a 5-year longitudinal dataset of 2,245 firm-year observations drawn from the S&P 500.FindingsThe results not only support the presence of an inverted U-shaped link between MO and firm performance, but also identify organizational confidence as an important moderator of this newly uncovered curvilinear relationship.Practical implicationsWhen it comes to the effect of MO on firm performance, there can be indeed be “too much of a good thing,” and managers should be aware of the trade-offs that come attached with overcommitting to a MO strategy.Originality/valueThe authors contribute to extant research on the MO–performance link by moving beyond simple linear relationships and identifying an inverted U-shaped relationship between MO and firm performance. This newly found curvilinear relationship may explain and reconcile prior contradicting findings on the benefits of MO. Organizational confidence is also found to trigger a shape-flip of the MO–performance link, thereby suggesting a new boundary condition.

The Role of Self-Efficacy and Aging in Managing Disease

2020 ◽  
pp. 207-253
Author(s):  
Debra N. Weiss-Randall
Keyword(s):  
Life Expectancy ◽  
Self Efficacy ◽  
Management Program ◽  
Self Management ◽  
Integrative Approach ◽  
Evidence Based ◽  
Quality Of Life Research ◽  
Key Factor ◽  
Causes Of Mortality ◽  
The U.S

In 1900, life expectancy in the U.S. was 47 years and infectious diseases were the leading cause of mortality; today, life expectancy in the U.S. is almost 80 years and chronic diseases are the leading causes of mortality. Eighty percent of adults 65 and older have multiple chronic health conditions, which are costly to treat. Offering older adults an evidence-based self-management program can reduce medical costs and improve patient outcomes and quality of life. Research has shown that self-efficacy is a key factor in effective self-management programs. The Chronic Disease Self-Management Program (CDSMP) is an evidence-based program that helps patients to boost their self-efficacy and improve their disease self-management, under the supervision of a physician. In addition, the use of evidence-based complementary modalities is recommended as part of an integrative approach to self-management to help patients manage the daily anger, fear, and depression that frequently accompany living with an incurable disease.

scholarly journals A Study on the Behavior of Clustering Techniques for Modeling Travel Time in Road-Based Mass Transit Systems

Proceedings ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 18
Author(s):  
Cristóbal ◽  
Padrón ◽  
Quesada-Arencibia ◽  
Alayón ◽  
Blasio ◽  
...  
Keyword(s):  
Travel Time ◽  
Behavior Pattern ◽  
Large Data ◽  
Mass Transit ◽  
Clustering Methods ◽  
Knowledge Modeling ◽  
Activity Data ◽  
Transit Systems ◽  
Clustering Techniques ◽  
Key Factor

In road-based mass transit systems, the travel time is a key factor affecting quality of service. For this reason, to know the behavior of this time is a relevant challenge. Clustering methods are interesting tools for knowledge modeling because these are unsupervised techniques, allowing hidden behavior patterns in large data sets to be found. In this contribution, a study on the utility of different clustering techniques to obtain behavior pattern of travel time is presented. The study analyzed three clustering techniques: K-medoid, Diana, and Hclust, studying how two key factors of these techniques (distance metric and clusters number) affect the results obtained. The study was conducted using transport activity data provided by a public transport operator.

Does Work Inhibit Cognitive Development During College?

1998 ◽  
Vol 20 (2) ◽  
pp. 75-93 ◽  
Author(s):  
Ernest T.Pascarella ◽  
Marcia I. Edison ◽  
Amaury Nora ◽  
Linda Serra Hagedorn ◽  
Patrick T.Terenzini
Keyword(s):  
Cognitive Development ◽  
Negative Impact ◽  
Positive Influence ◽  
Curvilinear Relationship ◽  
First Year ◽  
Background Characteristics ◽  
Student Background ◽  
Standardized Measures ◽  
Science Reasoning ◽  
Part Time

This longitudinal investigation of 23 colleges and universities sought to estimate the impacts of on- and off-campus work on standardized measures of student cognitive development across three years of college. With controls made for student background characteristics and other experiences of college, there was little evidence to suggest that either form of work inhibited cognitive development in the first year of college. In the second year of college, on-campus work had small negative total and direct influences on science reasoning, but neither form of work inhibited students’ writing skills. Both forms of work had a significant curvilinear relationship with a composite measure of end-of-third-year cognitive development consisting of reading comprehension and critical thinking. Part-time on- or off-campus work had a positive influence, but on-campus work in excess of 15 hours per week or off-campus work in excess of 20 hours per week had a negative impact. Finally, across all years of the study, the cognitive impacts of work appear to be essentially the same, irrespective of student characteristics (e.g., ethnicity, gender, age, precollege ability, full-or part-time enrollment) and whether or not the student attended a two-year or a four-year college.

Under-over benefitting perceptions and evaluation of services

2016 ◽  
Vol 26 (4) ◽  
pp. 430-447 ◽  
Author(s):  
Vicente Martínez-Tur ◽  
Yolanda Estreder ◽  
Carolina Moliner ◽  
Rosa María Sánchez-Hernández ◽  
José Mª Peiró
Keyword(s):  
Customer Service ◽  
Design Methodology ◽  
Curvilinear Relationship ◽  
Content Type ◽  
Nonlinear Relationships ◽  
Linear Relationships ◽  
Linear And Nonlinear ◽  
Competing Hypotheses ◽  
Curvilinear Relationships ◽  
Practical Implications

Purpose – In the context of service exchanges, the purpose of this paper is to examine the form of the link from under-benefitting (customers receive less than they invest) vs over-benefitting (customers receive more than they invest) perceptions to customer service evaluations. The authors assess three competing hypotheses: maximization, fairness, and the asymmetric hypotheses. Design/methodology/approach – Linear and nonlinear relationships between under-over benefitting perceptions and service evaluations are examined following a test-retest approach. These relationships are investigated in four samples from two survey studies: hotels (Time 1, n=591; Time 2, n=512) and restaurants (Time 1, n=536; Time 2, n=473). Findings – Results confirmed the existence of asymmetrical curvilinear relationships. Service evaluations improve sharply when perceptions move from under-benefitting perceptions to balanced situations. However, service evaluations do not improve in high over-benefitting situations. Practical implications – The design of employee tasks and services should avoid both under-benefitting perceptions and a disproportionate maximization of customer benefits. Originality/value – Previous research studies have investigated these types of relationships by computing linear relationships or comparing different groups of customers. The current research tests the link from under-over benefitting perceptions to customer service evaluations by also considering nonlinear relationships. This approach supports an asymmetrical curvilinear relationship that captures the complexity of service exchanges.

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