Mechanisms inducing spatially extended synchrony in mast seeding: The role of pollen coupling and environmental fluctuation

2004 ◽  
Vol 19 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Yoh IWASA ◽  
Akiko SATAKE
Keyword(s):  
Mast Seeding ◽  
Environmental Fluctuation ◽  
Spatially Extended

scholarly journals Features of the formation of the St. Petersburg agglomeration by the beginning of the XX century

2020 ◽  
Vol 164 ◽  
pp. 05009
Author(s):  
Sergey Sementsov ◽  
Svetozar Zavarikhin ◽  
Yuryi Kurbatov ◽  
Yuryi Pukharenko
Keyword(s):  
Urban Planning ◽  
Significant Role ◽  
Communication Analysis ◽  
Garden Cities ◽  
Central Russia ◽  
Environmental Transport ◽  
Spatially Extended ◽  
The Baltic ◽  
The City

The study of the Russian historical St. Petersburg agglomeration at all stages from its foundation (from 1703) until the final imperial stage (1917) required the use of complex functional, urban-planning and landscape, socio-economic, environmental, transport and communication analysis on the basis of data from archives, historical cartography and iconography. The main results were the conclusions that during the XVIII - early XX centuries, there was a crystallization of a huge agglomeration around the city of St. Petersburg, which included three belts: “external”, “middle”, “nearby”, which spatially extended from Yaroslavl (in Central Russia) to Riga (in the Baltic). The paper discusses the features of the formation of the “nearby belt” of agglomeration in the initial (1703 - January 1725) and in the final (1901-1916) development periods. The study revealed a significant role of special types of objects in these processes - estates of the aristocratic society and “garden cities” that provided a belt (around St. Petersburg and the largest settlements and complexes), linear (along radial and ring highways), and nodal (around individual large settlements) construction, spreading in the latitudinal direction from Narva and Ivangorod to the mouth of the Syas river, and in the meridian direction - from Vyborg to the city of Luga. Within the boundaries of this agglomeration zone, four sub-agglomerations had begun to emerge since the 1710s and have fully formed by the 1910s. The materials of the paper can be useful both for historians of urban planning and for modern urbanists.

Cellular distributions of creatine kinase in branchia of euryhaline tilapia (Oreochromis mossambicus)

2003 ◽  
Vol 284 (1) ◽  
pp. C233-C241 ◽  
Author(s):  
Li-Yih Lin ◽  
Chia-Chang Chiang ◽  
Hong-Yi Gong ◽  
Ching-Yi Cheng ◽  
Pung-Pung Hwang ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Cellular Localization ◽  
Potential Role ◽  
Oreochromis Mossambicus ◽  
Staining Intensity ◽  
Muscle Type ◽  
Environmental Fluctuation ◽  
High Association ◽  
Salinity Changes

Although euryhaline teleosts can adapt to environmental fluctuation of salinity, their energy source for responding to changes in salinity and osmolarity remains unclear. This study examines the cellular localization of creatine kinase (CK) expression in branchia of tilapia ( Oreochromis mossambicus). Western blot analysis of muscle-type CK (MM form) revealed a high association with salinity changes, but BB and MB forms of CK in the gills of fish adapted to seawater did not change. With the use of immunocytochemistry, three CK isoforms (MM, MB, and BB) were localized in mitochondria-rich (MR) cells and other epithelial cells of tilapia gills. In addition, staining intensity of MM-form CK in MR cells increased after seawater transfer, whereas BB and MB forms did not significantly change. To our knowledge, this work presents the first evidence of CK expression in MR cells of tilapia gills, highlighting the potential role of CK in providing energy for ion transport.

scholarly journals Mast seeding promotes evolution of scatter-hoarding

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Rafał Zwolak ◽  
Dale Clement ◽  
Andrew Sih ◽  
Sebastian J. Schreiber
Keyword(s):  
Plant Species ◽  
Environmental Variability ◽  
European Beech ◽  
Mast Seeding ◽  
Scatter Hoarding ◽  
Future Consumption ◽  
Seed Fall ◽  
The Cost ◽  
Parameter Values

Many plant species worldwide are dispersed by scatter-hoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatter-hoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners large advantages in cache recovery, by kin selection, or by introducing reciprocal pilferage of ‘shared’ seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behaviour, and the demography of scatterhoarders. The parameter values are based mostly on research on European beech ( Fagus sylvatica ) and yellow-necked mice ( Apodemus flavicollis ). Starvation of scatterhoarders between mast years decreases the population density that enters masting events, which leads to reduced seed pilferage. Satiation of scatterhoarders during mast events lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behaviour especially when interannual variation in seed fall and the period between masting events are large. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

scholarly journals Studying the genetic basis of masting

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Akiko Satake ◽  
Dave Kelly
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Mast Seeding ◽  
Ecological Genomics ◽  
Theme Issue ◽  
Natural Conditions ◽  
Genetic Level ◽  
Seed Crops

The mechanisms underlying mast seeding have traditionally been studied by collecting long-term observational data on seed crops and correlating seedfall with environmental variables. Significant progress in ecological genomics will improve our understanding of the evolution of masting by clarifying the genetic basis of masting traits and the role of natural selection in shaping those traits. Here, we summarize three important aspects in studying the evolution of masting at the genetic level: which traits govern masting, whether those traits are genetically regulated, and which taxa show wide variation in these traits. We then introduce recent studies on the molecular mechanisms of masting. Those studies measure seasonal changes in gene expression in natural conditions to quantify how multiple environmental factors combine to regulate floral initiation, which in many masting plant species is the single largest contributor to among-year variation in seed crops. We show that Fagaceae offers exceptional opportunities for evolutionary investigations because of its diversity at both the phenotypic and genetic levels and existing documented genome sequences. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

scholarly journals A spatially extended model to assess the role of landscape structure on the pollination service of Apis mellifera

2020 ◽  
Vol 431 ◽  
pp. 109201 ◽  
Author(s):  
Julien Joseph ◽  
Fernanda Santibáñez ◽  
María Fabiana Laguna ◽  
Guillermo Abramson ◽  
Marcelo N. Kuperman ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Landscape Structure ◽  
Extended Model ◽  
Pollination Service ◽  
Spatially Extended

scholarly journals Multiple nest entrances alter foraging and information transfer in ants

2020 ◽  
Vol 7 (2) ◽  
pp. 191330 ◽  
Author(s):  
Marine Lehue ◽  
Bertrand Collignon ◽  
Claire Detrain
Keyword(s):  
Information Transfer ◽  
Food Source ◽  
Lower Amount ◽  
Foraging Efficiency ◽  
Foraging Patterns ◽  
Social Exchanges ◽  
Spatially Extended ◽  
Ecological Success ◽  
Transfer Of Information

The ecological success of ants relies on their ability to discover and collectively exploit available resources. In this process, the nest entrances are key locations at which foragers transfer food and information about the surrounding environment. We assume that the number of nest entrances regulates social exchanges between foragers and inner-nest workers, and hence influences the foraging efficiency of the whole colony. Here, we compared the foraging responses of Myrmica rubra colonies settled in either one-entrance or two-entrance nests. The total outflows of workers exploiting a sucrose food source were similar regardless of the number of nest entrances. However, in the two-entrance nests, the launching of recruitment was delayed, a pheromone trail was less likely to emerge between the nest and the food source, and recruits were less likely to reach the food target. As a result, an additional entrance through which information could transit decreased the efficiency of social foraging and ultimately led to a lower amount of retrieved food. Our study confirms the key-role of nest entrances in the transfer of information from foragers to potential recruits. The influence of the number of entrances on the emergence of a collective trail also highlights the spatially extended impact of the nest architecture that can shape foraging patterns outside the nest.

ROLE OF MIGRATORY BIRDS UNDER ENVIRONMENTAL FLUCTUATION — A MATHEMATICAL STUDY

2008 ◽  
Vol 16 (01) ◽  
pp. 81-106 ◽  
Author(s):  
SAMRAT CHATTERJEE ◽  
S. PAL ◽  
J. CHATTOPADHYAY
Keyword(s):  
Migratory Birds ◽  
Threshold Value ◽  
Disease Spread ◽  
Control Procedure ◽  
Mathematical Study ◽  
Environmental Fluctuation ◽  
Environmental Disturbances ◽  
Proposed Model ◽  
Account Standard

Chatterjee and Chattopadhyay1proposed and analyzed a simple one season eco-epidemiological model to understand the role of migratory birds in an eco-epidemiological scenario. In this paper, we have modified their model taking into account standard incidence as horizontal incidence. We have studied the proposed model both in the absence and in the presence of environmental disturbances. From our analysis, we observe that in the absence of the environmental fluctuations, the disease spread by migratory birds may be controlled by either decreasing the contact rate, or increasing the recovery or predation rates. Further, we also observe that if the artificial eutrophication (or intensity of white noise) is kept under a certain threshold value, the control procedure proposed in the deterministic case is also valid in the presence of environmental disturbances.

scholarly journals Numerical Bifurcation Methods applied to Climate Models: Analysis beyond Simulation

2019 ◽  
Author(s):  
Henk A. Dijkstra
Keyword(s):  
Degrees Of Freedom ◽  
Climate Models ◽  
State Of The Art ◽  
Climate System ◽  
Special Issue ◽  
Personal View ◽  
Spatially Extended ◽  
System Variability ◽  
Numerical Bifurcation

Abstract. In this special issue contribution, I provide a personal view on the role of bifurcation analysis of climate models in the development of a theory of climate system variability. The state-of-the-art of the methodology is shortly outlined and the main part of the paper deals with examples of what has been done and what has been learned. In addressing these issues, I will discuss the role of a hierarchy of climate models, concentrate on results for spatially extended (stochastic) models (having many degrees of freedom) and evaluate the importance of these results for a theory of climate system variability.

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