scholarly journals Partial migration in a subtropical wading bird in the Southeastern U.S.

2019 ◽  
Author(s):  
Simona Picardi ◽  
Peter C. Frederick ◽  
Rena R. Borkhataria ◽  
Mathieu Basille
Keyword(s):  
Quantitative Description ◽  
Partial Migration ◽  
Food Supplementation ◽  
Gps Tracking ◽  
Future Research ◽  
Sympatric Populations ◽  
Distributed Resources ◽  
Wood Stork ◽  
Wading Bird ◽  
Migratory Patterns

ABSTRACTThe function of migration is to allow exploitation of resources whose availability is heterogeneous in space and time. Much effort has been historically directed to studying migration as a response to seasonal, predictable fluctuations in resource availability in temperate species. A deeper understanding of how different migration patterns emerge in response to different patterns of resource variation requires focusing on species inhabiting less predictable environments, especially in tropical and subtropical areas. We provide the first individual-based, quantitative description of migratory patterns in a subtropical wading bird in the Southeastern U.S., the wood stork (Mycteria americana). Using GPS tracking data for 64 individuals tracked between 2004 and 2017, we classified migratory behavior at the individual-year level using information theory-based model selection on non-linear models of net squared displacement. We found that the wood stork population is partially migratory, with 59% of individuals seasonally commuting between winter ranges in Florida and summer ranges elsewhere in the population range (migrants), and 28% remaining in a single area in Florida year-round (residents). Additionally, 13% of storks act as facultative migrants, migrating in some years but not in others. Comparing the distribution of residents and migrants suggests that different migratory strategies might be associated with the use of different or differently distributed resources, possibly including food supplementation from human activities. The existence of facultative migrants shows the potential for plastic change of migratory patterns. Partial migration in wood storks may be an adaptation to high heterogeneity and unpredictability of food resources. We suggest that future research should focus on wading birds as model species for the study of partial migration as an adaptation to heterogeneous and unpredictable environments, by comparing populations of the same species across different wetland systems and sympatric populations of species that differ in their resource acquisition mechanisms.

scholarly journals The use of nocturnal flights for barrier crossing in a diurnally migrating songbird

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Christie D. Lavallée ◽  
Saeedeh Bani Assadi ◽  
Alicia M. Korpach ◽  
James D. Ray ◽  
Jason D. Fischer ◽  
...  
Keyword(s):  
Energy Savings ◽  
Open Water ◽  
Gps Tracking ◽  
Future Research ◽  
Barrier Crossing ◽  
Migration Patterns ◽  
Migration Strategies ◽  
Diurnal Migrant ◽  
Time And Energy ◽  
High Degree

Abstract Background The migration patterns of land birds can generally be divided into those species that migrate principally during the day and those that migrate during the night. Some species may show individual plasticity in the use of day or night flight, particularly when crossing large, open-water or desert barriers. However, individual plasticity in circadian patterns of migratory flights in diurnally migrating songbirds has never been investigated. Methods We used high precision GPS tracking of a diurnal, migratory swallow, the purple martin (Progne subis), to determine whether individuals were flexible in their spring migration strategies to include some night flight, particularly at barrier crossing. Results Most (91%) of individuals made large (sometimes > 1000 km), open-water crossings of the Caribbean Sea and the Gulf of Mexico that included the use of night flight. 32% of all water crossings were initiated at night, demonstrating that night flight is not only used to complete large crossings but may confer other advantages for diurnal birds. Birds were not more likely to initiate crossings with supportive winds, however crossings were more likely when they reduced travel distances. Our results are consistent with diurnal birds using night flight to help achieve time- and energy-savings through ‘short cuts’ at barrier crossings, at times and locations when foraging opportunities are not available. Conclusions Overall, our results demonstrate the use of nocturnal flight and a high degree of individual plasticity in migration strategies on a circadian scale in a species generally considered to be a diurnal migrant. Nocturnal flights at barrier crossing may provide time and energy savings where foraging opportunities are low in an otherwise diurnal strategy. Future research should target how diel foraging and refueling strategies support nocturnal flights and barrier crossing in this and other diurnal species.

scholarly journals Partial migration in a subtropical wading bird in the southeastern United States

Ecosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Simona Picardi ◽  
Peter C. Frederick ◽  
Rena R. Borkhataria ◽  
Mathieu Basille
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Partial Migration ◽  
Wading Bird

scholarly journals A bibliometric approach to quantitatively assess current research trends in 5G security

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
M. Najmul Islam Farooqui ◽  
Junaid Arshad ◽  
Muhammad Mubashir Khan
Keyword(s):  
State Of The Art ◽  
Research Work ◽  
Quantitative Description ◽  
Research Trends ◽  
Security And Privacy ◽  
Future Research ◽  
Content Type ◽  
Research Areas ◽  
Art Research ◽  
5G Security

PurposeAlongside the remarkable evolution of cellular communication to 5G networks, significant security and privacy challenges have risen which can affect the widespread adoption of advanced communication technologies. In this context, the purpose of this paper is to examine research within security and privacy for 5G-based systems highlighting contributions made by the research community and identify research trends within different subdomains of 5G security where open issues still exist.Design/methodology/approachThis paper uses a bibliographic approach to review the state-of-the-art in the field of 5G security and is the pioneering effort to investigate 5G security research using this methodology. Specifically, the paper presents a quantitative description of the existing contributions in terms of authors, organizations, and countries. It then presents detailed keyword and co-citation analysis that shows the quantity and pattern of research work in different subfields. Finally, 5G security areas are identified having open challenges for future research work.FindingsThe study shows that China leads the world in terms of published research in the field of 5G security with USA and India ranked second and third respectively. Xidian University, China is ranked highest for number of publications and h-index followed by University Oulu and AALTO University Finland. IEEE Access, Sensors and IEEE Internet of Things Journal are the top publication venues in the field of 5G security. Using VOSViewer aided analysis with respect to productivity, research areas and keywords, the authors have identified research trends in 5G security among scientific community whilst highlighting specific challenges which require further efforts.Originality/valueExisting studies have focused on surveys covering state-of-the art research in secure 5G network (Zhang et al. 2019), physical layer security (Wu et al., 2018), security and privacy of 5G technologies (Khan et al., 2020) and security and privacy challenges when 5G is used in IoT (Sicari et al. 2020). However, our research has revealed no existing bibliometric studies in this area and therefore, to our best knowledge, this paper represents pioneering such effort for security within 5G.

scholarly journals Electricity market strategies applied to microgrid development

2020 ◽  
Vol 11 (1) ◽  
pp. 530
Author(s):  
Carlos Ulises Cassiani ◽  
John Edwin Candelo Becerra ◽  
Fredy Edimer Hoyos
Keyword(s):  
Electricity Market ◽  
Renewable Resources ◽  
Fossil Fuels ◽  
Current System ◽  
Future Research ◽  
Distributed Resources ◽  
Electrical Grids ◽  
Market Strategies ◽  
Great Development ◽  
The Way

<span>Over the last decade, the liberalization of the electricity market has been sought. In order to fight the environmental impact caused by the use of fossil fuels, it is aimed to change the current system of centralized generation and achieve a more distributed one; distributed resources can use renewable or non-renewable resources as main source of energy, one way to implement these distributed systems is through micro electrical grids, since these allow improving energy efficiency. The way to efficiently implement this type of network is an important point to be solved in future research and even more if the way of conducting an electricity market for different communities is unknown. That is why this text presents the characteristics of microgrids, the management of microgrids, and the wide and promising panorama of future opportunities for a great development of this type of grid.</span>

scholarly journals Residual Properties in Damaged Laminated Composites through Nondestructive Testing: A Review

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4513
Author(s):  
Carlo Boursier Niutta ◽  
Andrea Tridello ◽  
Davide S. Paolino ◽  
Giovanni Belingardi
Keyword(s):  
Composite Structures ◽  
Damage Tolerance ◽  
Laminated Composites ◽  
Quantitative Description ◽  
Material Behavior ◽  
Future Research ◽  
Widespread Application ◽  
Residual Properties ◽  
Nondestructive Techniques ◽  
Material State

The development of damage tolerance strategies in the design of composite structures constitutes a major challenge for the widespread application of composite materials. Damage tolerance approaches require a proper combination of material behavior description and nondestructive techniques. In contrast to metals, strength degradation approaches, i.e., the residual strength in presence of cracks, are not straightforwardly enforceable in composites. The nonhomogeneous nature of such materials gives rise to several failure mechanisms and, therefore, the definition of an ultimate load carrying capacity is ambiguous. Nondestructive techniques are thus increasingly required, where the damage severity is quantified not only in terms of damage extension, but also in terms of material response of the damaged region. Based on different approaches, many nondestructive techniques have been proposed in the literature, which are able to provide a quantitative description of the material state. In the present paper, a review of such nondestructive techniques for laminated composites is presented. The main objective is to analyze the damage indexes related to each method and to point out their significance with respect to the residual mechanical performances, as a result of the working principle of each retained technique. A possible guide for future research on this subject is thus outlined.

Investigating the Relationships between Mobility Behaviours and Indicators of Subjective Well–Being Using Smartphone–Based Experience Sampling and GPS Tracking

2020 ◽  
Vol 34 (5) ◽  
pp. 714-732
Author(s):  
Sandrine R. Müller ◽  
Heinrich Peters ◽  
Sandra C. Matz ◽  
Weichen Wang ◽  
Gabriella M. Harari
Keyword(s):  
Experience Sampling ◽  
Movement Patterns ◽  
Past Research ◽  
Well Being ◽  
Gps Tracking ◽  
Future Research ◽  
Subjective Well Being ◽  
Personality Psychology ◽  
Physical Environments ◽  
Using Data

People interact with their physical environments every day by visiting different places and moving between them. Such mobility behaviours likely influence and are influenced by people's subjective well–being. However, past research examining the links between mobility behaviours and well–being has been inconclusive. Here, we provide a comprehensive investigation of these relationships by examining individual differences in two types of mobility behaviours (movement patterns and places visited) and their relationship to six indicators of subjective well–being (depression, loneliness, anxiety, stress, affect, and energy) at two different temporal levels of analysis (two–week tendencies and daily level). Using data from a large smartphone–based longitudinal study ( N = 1765), we show that (i) movement patterns assessed via GPS data (distance travelled, entropy, and irregularity) and (ii) places visited assessed via experience sampling reports (home, work, and social places) are associated with subjective well–being at the between and within person levels. Our findings suggest that distance travelled is related to anxiety, affect, and stress, irregularity is related to depression and loneliness, and spending time in social places is negatively associated with loneliness. We discuss the implications of our work and highlight directions for future research on the generalizability to other populations as well as the characteristics of places. © 2020 European Association of Personality Psychology

scholarly journals Migration costs drive convergence of threshold traits for migratory tactics

2013 ◽  
Vol 280 (1773) ◽  
pp. 20132539 ◽  
Author(s):  
Genki Sahashi ◽  
Kentaro Morita
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Partial Migration ◽  
Size At Maturity ◽  
Selective Force ◽  
Threshold Trait ◽  
Salmonid Species ◽  
Migratory Patterns ◽  
Migration Costs

Partial migration of some, but not all, members of a population is a common form of migration. We evaluated how migration costs influence which members migrate in 10 populations of two salmonid species. The migratory patterns of both species were evaluated based on the size at maturity for resident males, which is the threshold trait that determines the migratory tactics used within a population. In both species, this size was smaller in males located further from the sea, where migration costs are presumably higher. Moreover, the threshold sizes at maturity in males were correlated between both species. Our results suggest that migration costs are a significant convergent selective force on migratory tactics and life-history traits in nature.

Comparing ecological momentary assessment to sensor-based approaches in predicting dietary lapse

2021 ◽  
Author(s):  
Rebecca J Crochiere ◽  
Fengqing (Zoe) Zhang ◽  
Adrienne S Juarascio ◽  
Stephanie P Goldstein ◽  
J Graham Thomas ◽  
...  
Keyword(s):  
Risk Factors ◽  
Weight Loss ◽  
Ecological Momentary Assessment ◽  
Self Report ◽  
Gps Tracking ◽  
Future Research ◽  
Model Accuracy ◽  
Prediction Rate ◽  
Ecological Momentary ◽  
Momentary Assessment

Abstract Ecological momentary assessment (EMA; brief self-report surveys) of dietary lapse risk factors (e.g., cravings) has shown promise in predicting and preventing dietary lapse (nonadherence to a dietary prescription), which can improve weight loss interventions. Passive sensors also can measure lapse risk factors and may offer advantages over EMA (e.g., objective, automatic, semicontinuous data collection), but currently can measure only a few lapse predictors, a notable limitation. This study preliminarily compared the burden and accuracy of commercially available sensors versus established EMA in lapse prediction. N = 23 adults with overweight/obesity completed a 6-week commercial app-based weight loss program. Participants wore a Fitbit, enabled GPS tracking, completed EMA, and reported on EMA and sensor burden poststudy via a 5-point Likert scale. Sensed risk factors were physical activity and sleep (accelerometer), geolocation (GPS), and time, from which 233 features (measurable characteristics of sensor signals) were extracted. EMA measured 19 risk factors, lapse, and categorized GPS into meaningful geolocations. Two supervised binary classification models (LASSO) were created: the sensor model predicted lapse with 63% sensitivity (true prediction rate of lapse) and 60% specificity (true prediction rate of non-lapse) and EMA model with 59% sensitivity and 72% specificity. EMA model accuracy was higher, but self-reported EMA burden (M = 2.96, SD = 1.02) also was higher (M = 1.50, SD = 0.94). EMA model accuracy was superior, but EMA burden was higher than sensor burden. Findings highlight the promise of sensors in contributing to lapse prediction, and future research may use EMA, sensors, or both depending on prioritization of accuracy versus participant burden.

Toward an Information Management Infrastructure for Product Family Planning and Mass Customization

2004 ◽  
Author(s):  
Steven B. Shooter ◽  
Timothy W. Simpson ◽  
Soundar R. T. Kumara ◽  
Robert B. Stone ◽  
Janis P. Terpenny
Keyword(s):  
Family Planning ◽  
Product Development ◽  
Information Management ◽  
New Product Development ◽  
Product Family ◽  
Future Research ◽  
Distributed Resources ◽  
Future Research Directions ◽  
Realization Process ◽  
Product Realization

Complex new product development requires numerous decisions by many individuals and groups, which are often geographically and temporally distributed. There is a need to share and coordinate distributed resources and synchronize decisions, and recent advances in information technology (IT) pose an untapped potential for assisting in the capture, storage, retrieval and facilitated use of product development information. We exploit IT to address this problem through the proposed approach to Product Family Planning. By sharing assets such as components, processes and knowledge across a family of products, companies can efficiently develop differentiated products and increase the flexibility and responsiveness of their product realization process. In this paper we describe our recent efforts in realizing an information management infrastructure for product family planning and platform customization. In particular, we focus on three current research thrusts to identify product platform leveraging strategies to support future product family planning: (1) an evolutionary approach to product platforming, (2) a bottom-up approach to product platforming, and (3) industry-based platform case studies. Future research directions are also outlined.

Annual migratory patterns of Far East Greylag Geese ( Anser anser rubrirostris ) revealed by GPS tracking

2020 ◽  
Vol 15 (3) ◽  
pp. 213-223
Author(s):  
Xianghuang LI ◽  
Xin WANG ◽  
Lei FANG ◽  
Nyambayar BATBAYAR ◽  
Tseveenmyadag NATSAGDORJ ◽  
...  
Keyword(s):  
Far East ◽  
Gps Tracking ◽  
Anser Anser ◽  
Migratory Patterns ◽  
Greylag Geese
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