Long-Term Dynamics of Bird Dispersal Network Structures Associated with the Functions in Bird Migration and Fruit Abundance

2021 ◽  
Author(s):  
Kyohsuke Ohkawara ◽  
Kazuya Kimura ◽  
Fumio Satoh
Keyword(s):  
Time Scale ◽  
Bird Migration ◽  
Bird Species ◽  
Factors Affecting ◽  
Fruit Abundance ◽  
Positive Effects ◽  
Bird Dispersal ◽  
Long Time ◽  
Nested Structure ◽  
Migrant Birds

Abstract In temperate zones, the complex network of seed dispersal by migrant birds is formed and the structure is dynamic on long time scale. Over 12 years, we examined interannual variability of structures of bird dispersal networks and factors affecting them by observing the characteristics of fruit abundance, bird migration and bird dispersal interactions in central Japan. The fruit abundance exhibited a remarkable fluctuation across years, with the number of fruiting trees and matured fruits fluctuating repeatedly every other year, leading to the periodic fluctuations. The abundance of migrants was also fluctuated. According to the abundance of fruits and migrants, the 12 years as study period was classified into three types. The seed transporting frequency and the dispersal networks were investigated by collecting faeces of migrants. Of the 6652 samples collected from 15 bird species, 1671 (25.1%) included seeds from 60 plant species. Main dispersers were composed of Turdus pallidus, T. obscurus and Zosterops japonicus. The structures of bird dispersal networks were highly nested over 12 years, suggesting the networks are stable. Specifically, the nested structure developed in years when fruit abundance was low. GLM analyses showed the abundance of migrants, particularly T. pallidus and T. obscurus, had strong positive effects on construction of nested structure. The development of nested structure may be caused by the fact the two Turdus species were more frequently functioning as generalist dispersers when fruit abundance was lower. Our study revealed one of the mechanisms determining the structure of bird dispersal network on long time scale.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

Using Self-report to Study How Application affect Motivation of Behavior Change (Preprint)

2020 ◽  
Author(s):  
Yuan Yin ◽  
Yurong Yu
Keyword(s):  
Behavior Change ◽  
Self Report ◽  
Group Method ◽  
Behavior Changes ◽  
Technology Design ◽  
Factors Affecting ◽  
Negative Results ◽  
Long Time ◽  
Ecological Momentary ◽  
Positive Effect

BACKGROUND Currently, changing behaviors with the assistance of mobile applications has been popularized. However, most of the participants are unable to persist in participating in behavior-changing activities for a long time. Some researchers have studied what factors motivate people to maintain behaviors-changing actions. There has been controversy about whether the commonly used triggers, negative results or competitions, could motivate behavior changes. In the meantime, the main methodology these researchers have been using is to conduct experiments, from which data was collected from subjects’ recalling previous behavior changing. The experiments are time-consuming, and the results can be unreliable. To resolve this problem, the Ecological Momentary Assessment (EMA) was developed to record real-time feedback. However, the EMA unavoidably increases the workload of the subjects. OBJECTIVE This study investigated the factors affecting behavior change, especially from the motivation aspect. Additionally, this paper attempted to identify a way to record human behavior changes without increasing the subjects’ workload. METHODS The methodology of “self-report” was adopted to report how people’s views regarding the behavior-changing intervention. To achieve a balance between workload and being timely, the self-reporting data was recorded once a day. After the 28-day “self-report” experiment, the “focus group” method was used to gather people’s feedback on behavior changing process. RESULTS This paper identified 9 factors: cooperation, competition, award, understandable graphic, reminder and alarm, trust and willing, gender, relation with disease and environmental factors). These factors could affect motivation of behavior changing. Besides, we found that negative results could be a motivation for behavior changing. In the experiment, we also found that a small number of subjects tended to cheat for a more “beautiful” result. The last part of the paper has presented possible implications for technology design to facilitate behavior-changing. CONCLUSIONS In particular, (i) the research promoted the possibility of cheating when recording data which is ignored by existing research and will make the digital applications less useful; (ii) the results show that not all cooperation is needed to lead to a positive effect; (iii) the research identified the negative results caused by over-competition in behavior change. Finally, the paper proposes technology design directions should focus on giving motivation through keeping dairy, negative results feedback and avoid cheating.

scholarly journals Core Elements Affecting Sharing: Evidence from the United States

2021 ◽  
Vol 13 (7) ◽  
pp. 3943
Author(s):  
Aurelija Burinskienė ◽  
Edita Leonavičienė ◽  
Virginija Grybaitė ◽  
Olga Lingaitienė ◽  
Juozas Merkevičius
Keyword(s):  
United States ◽  
The United States ◽  
Collaborative Consumption ◽  
Factors Affecting ◽  
Use Of Resources ◽  
Personal Consumption ◽  
Depth Analysis ◽  
Core Elements ◽  
Long Time ◽  
Number Of Visits

The new phenomenon called sharing or collaborative consumption emerged a decade ago and is continuously growing. It creates new possibilities for society, and especially for business, is beneficial for the environment, makes more efficient use of resources, and presents a new competitive business model. The scientific literature lacks a more in-depth analysis of the factors influencing sharing activity growth; therefore, the paper’s authors attempt to fill this gap. The authors aim to identify the factors affecting the use of sharing platforms. To reach the goal, the authors developed a regression model and constructed a list of 71 variables. The study used monthly United States data from January 2017 to June 2020 from the publicly available Federal Reserve Economic Data (FRED)and Google trends databases. The comparison to other indexes proves that the proposed index, representing the number of visits to sharing platforms (SEP), is a unique one. The first index allowed us to revise the sharing activity monthly. The authors identified that variables such as wage level, social network users, import level, and personal consumption are critical in affecting the number of visits to sharing platforms. The presented framework could be helpful for practitioners and policymakers analysing the stimulation of sharing or collaborative consumption. It includes indicators representing different areas, such as society, technology, and country, and allows for monthly investigations. Such activity was evident for a long time when online platforms contributed to its wider accessibility. The results help to forecast the number of visits monthly. Sharing is still an emerging area for research; thus, the authors tried to explore the phenomenon of sharing to expand the conceptual level of knowledge.

scholarly journals Long-Time-Scale Magnetization Ordering Induced by an Adsorbed Chiral Monolayer on Ferromagnets

ACS Nano ◽  
2021 ◽  
Author(s):  
I. Meirzada ◽  
N. Sukenik ◽  
G. Haim ◽  
S. Yochelis ◽  
L. T. Baczewski ◽  
...  
Keyword(s):  
Time Scale ◽  
Long Time

scholarly journals Factors Affecting Teaching English as a Second Language (TESL) Postgraduate Students’ Behavioural Intention for Online Learning during the COVID-19 Pandemic

2021 ◽  
Vol 13 (6) ◽  
pp. 3524
Author(s):  
Melor Md Yunus ◽  
Wee Shin Ang ◽  
Harwati Hashim
Keyword(s):  
Online Learning ◽  
Survey Design ◽  
Behavioural Intention ◽  
Intention To Use ◽  
Postgraduate Students ◽  
Factors Affecting ◽  
Positive Effects ◽  
Performance Expectancy ◽  
Use Of Technology ◽  
Facilitating Conditions

Online learning has become essential in education as the spread of coronavirus 19 (COVID-19) pandemic has brought significant changes to the field. However, education should remain welcoming and supportive to all the learners as it is important to keep the students’ behavioural intention in any form of learning environment. Thus, this study is significant as online learning is leading the trend of education now. Past studies revealed that the factors of performance expectancy, effort expectancy, social influence, and facilitating conditions under the unified theory of acceptance and use of technology (UTAUT) model affect learners’ behavioural intention to use online learning. This study intended to identify the most significant factors that influence TESL postgraduate students’ behavioural intention towards the use of online learning during the COVID-19 pandemic. It also examined the relationship amongst the four factors and postgraduate students’ behavioural intention to use online learning. The participants consisted of 169 postgraduate students at a public university in Malaysia. To achieve the aim, the study utilized a survey design using a questionnaire. The results from regression analysis revealed that all of the factors have positive effects on postgraduate students’ behavioural intention to use online learning. Meanwhile, performance expectancy has the greatest influence on postgraduate students’ behavioural intention. Hence, this study concludes that the practicality and the usefulness of online learning should be highlighted by the authorities.

scholarly journals Dynamics of transposable elements under the selection model

1999 ◽  
Vol 74 (2) ◽  
pp. 159-164 ◽  
Author(s):  
A. TSITRONE ◽  
S. CHARLES ◽  
C. BIÉMONT
Keyword(s):  
Equilibrium Point ◽  
Dynamic Characteristics ◽  
Time Scale ◽  
Copy Number ◽  
Stable Equilibrium ◽  
Stable Equilibrium Point ◽  
Asymptotically Stable ◽  
Weak Selection ◽  
Strong Selection ◽  
Long Time

We examine an analytical model of selection against the deleterious effects of transposable element (TE) insertions in Drosophila, focusing attention on the asymptotic and dynamic characteristics. With strong selection the only asymptotically stable equilibrium point corresponds to extinction of the TEs. With very weak selection a stable and realistic equilibrium point can be obtained. The dynamics of the system is fast for strong selection and slow, on the human time scale, for weak selection. Hence weak selection acts as a force that contributes to the stabilization of mean TE copy number. The consequence is that under weak selection, and ‘out-of-equilibrium’ situation can be maintained for a long time in populations, with mean TE copy number appearing stabilized.

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