scholarly journals Ecological and social pressures interfere with homeostatic sleep regulation in the wild

2021 ◽  
Author(s):  
J. Carter Loftus ◽  
Roi Harel ◽  
Chase L Nuñez ◽  
Margaret C Crofoot
Keyword(s):  
Spatial Scales ◽  
Sleep Patterns ◽  
Sleep Regulation ◽  
Papio Anubis ◽  
Physiological Importance ◽  
Social Pressures ◽  
Trade Offs ◽  
Sleep Homeostasis ◽  
In The Wild ◽  
Function Of Sleep

Sleep is fundamental to the health and fitness of all animals. The physiological importance of sleep is underscored by the central role of homeostasis in determining sleep investment – following periods of sleep deprivation, individuals experience longer and more intense sleep bouts. Yet, most studies of sleep have been conducted in highly controlled settings, disconnected from the ecological and social context that may exert pressures on sleep patterns in conflict with homeostatic regulation. Using tri-axial accelerometry and GPS to track the sleep patterns of a group of wild baboons (Papio anubis) at multiple temporal and spatial scales, we found that ecological and social pressures indeed interfere with homeostatic sleep regulation. Baboons sacrificed time spent sleeping when in less familiar locations and when sleeping in proximity to more group-mates, regardless of how much they had slept the prior night or how much they had physically exerted themselves the preceding day. Moreover, we found that the collective dynamics characteristic of social animal groups persist into the sleep period, as baboons exhibited synchronized patterns of waking throughout the night, particularly with nearby group-mates. Thus, for animals whose fitness depends critically on avoiding predation and developing social relationships, maintaining sleep homeostasis may be only secondary to remaining vigilant when sleeping in risky habitats and interacting with group-mates during the night. Our results highlight the importance of studying sleep in ecologically relevant contexts, where the adaptive function of sleep patterns directly reflect the complex trade-offs that have guided its evolution.

Homeostatic Response to Sleep Restriction in Adolescents

SLEEP ◽  
2021 ◽  
Author(s):  
Jelena Skorucak ◽  
Nathan Weber ◽  
Mary A Carskadon ◽  
Chelsea Reynolds ◽  
Scott Coussens ◽  
...  
Keyword(s):  
Slow Wave ◽  
Process Model ◽  
Animal Studies ◽  
Sleep Restriction ◽  
Sleep Regulation ◽  
Homeostatic Process ◽  
Sleep Homeostasis ◽  
High Prevalence ◽  
Homeostatic Response ◽  
Chronic Sleep

Abstract The high prevalence of chronic sleep restriction in adolescents underscores the importance of understanding how adolescent sleep is regulated under such conditions. One component of sleep regulation is a homeostatic process: if sleep is restricted, then sleep intensity increases. Our knowledge of this process is primarily informed by total sleep deprivation studies and has been incorporated in mathematical models of human sleep regulation. Several animal studies, however, suggest that adaptation occurs in chronic sleep restriction conditions, showing an attenuated or even decreased homeostatic response. We investigated the homeostatic response of adolescents to different sleep opportunities. Thirty-four participants were allocated to one of three groups with 5, 7.5 or 10 h of sleep opportunity per night for 5 nights. Each group underwent a protocol of 9 nights designed to mimic a school week between 2 weekends: 2 baseline nights (10 h sleep opportunity), 5 condition nights (5, 7.5 or 10 h), and two recovery nights (10 h). Measures of sleep homeostasis (slow-wave activity and slow-wave energy) were calculated from frontal and central EEG derivations and compared to predictions derived from simulations of the homeostatic process of the two-process model of sleep regulation. Only minor differences were found between empirical data and model predictions, indicating that sleep homeostasis is preserved under chronic sleep restriction in adolescents. These findings improve our understanding of effects of repetitive short sleep in adolescents.

scholarly journals Economic and ecological trade-offs of agricultural specialization at different spatial scales

2016 ◽  
Vol 122 ◽  
pp. 111-120 ◽  
Author(s):  
Stephan Klasen ◽  
Katrin M. Meyer ◽  
Claudia Dislich ◽  
Michael Euler ◽  
Heiko Faust ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Trade Offs

A framework for the Integrated Assessment of SDG trade-offs in the Sundarbans Biosphere Reserve.

2021 ◽  
Author(s):  
Charlotte Marcinko ◽  
Robert Nicholls ◽  
Tim Daw ◽  
Sugata Hazra ◽  
Craig Hutton ◽  
...  
Keyword(s):  
Environmental Change ◽  
Integrated Assessment ◽  
Spatial Scales ◽  
Strong Dependence ◽  
Management Strategies ◽  
Rural Livelihoods ◽  
Biosphere Reserve ◽  
Integrated Analysis ◽  
Trade Offs ◽  
The Sundarbans

<p>The United Nations Sustainable Development Goals (SDGs) and their corresponding targets are significantly interconnected, with many interactions, synergies and trade-offs between individual goals across multiple temporal and spatial scales.  We propose a framework for the Integrated Assessment Modelling (IAM) of a complex deltaic socio-ecological system in order to analyse such SDG interactions. We focus on the Sundarbans Biosphere Reserve (SBR), India within the Ganges-Brahmaputra-Meghna Delta. It is densely populated with 4.4 million people (2011), high levels of poverty and a strong dependence on rural livelihoods. It is only 50 km from the growing megacity of Kolkata (about 15 million people in 2020). The area also includes the Indian portion of the world’s largest mangrove forest – the Sundarbans – hosting the iconic Bengal Tiger. Like all deltaic systems, this area is subject to multiple drivers of environmental change operating across different scales. The IAM framework is designed to investigate current and future trends in socio-environmental change and explore associated policy impacts, considering a broad range of sub-thematic SDG indicators. Integration is achieved through the soft coupling of multiple sub-models, knowledge and data of relevant environmental and socio-economic processes.  The following elements are explicitly considered: (1) agriculture; (2) aquaculture; (3) mangroves; (4) fisheries; and (5) multidimensional poverty. Key questions that can be addressed include the implications of changing monsoon patterns, trade-offs between agriculture and aquaculture, or the future of the Sundarbans mangroves under sea-level rise and different management strategies, including trade-offs with land use to the north.  The novel high-resolution analysis of SDG interactions allowed by the IAM will provide stakeholders and policy makers the opportunity to prioritize and explore the SDG targets that are most relevant to the SBR and provide a foundation for further integrated analysis.</p>

scholarly journals A multiscale approach to balance trade-offs among dam infrastructure, river restoration, and cost

2018 ◽  
Vol 115 (47) ◽  
pp. 12069-12074 ◽  
Author(s):  
Samuel G. Roy ◽  
Emi Uchida ◽  
Simone P. de Souza ◽  
Ben Blachly ◽  
Emma Fox ◽  
...  
Keyword(s):  
New England ◽  
River Restoration ◽  
Spatial Scales ◽  
Dam Removal ◽  
The United States ◽  
Multiscale Approach ◽  
Funding Policy ◽  
Net Benefit ◽  
Trade Offs ◽  
Aging Infrastructure

Aging infrastructure and growing interests in river restoration have led to a substantial rise in dam removals in the United States. However, the decision to remove a dam involves many complex trade-offs. The benefits of dam removal for hazard reduction and ecological restoration are potentially offset by the loss of hydroelectricity production, water supply, and other important services. We use a multiobjective approach to examine a wide array of trade-offs and synergies involved with strategic dam removal at three spatial scales in New England. We find that increasing the scale of decision-making improves the efficiency of trade-offs among ecosystem services, river safety, and economic costs resulting from dam removal, but this may lead to heterogeneous and less equitable local-scale outcomes. Our model may help facilitate multilateral funding, policy, and stakeholder agreements by analyzing the trade-offs of coordinated dam decisions, including net benefit alternatives to dam removal, at scales that satisfy these agreements.

scholarly journals Memories of Migrations Past: Sociality and Cognition in Dynamic, Seasonal Environments

2021 ◽  
Vol 9 ◽  
Author(s):  
Eliezer Gurarie ◽  
Sriya Potluri ◽  
George Christopher Cosner ◽  
Robert Stephen Cantrell ◽  
William F. Fagan
Keyword(s):  
Environmental Changes ◽  
Animal Movement ◽  
Spatial Scales ◽  
Rapid Change ◽  
Reference Memory ◽  
Migratory Behavior ◽  
Migration Behavior ◽  
Long Distance ◽  
Trade Offs ◽  
Resource Dynamics

Seasonal migrations are a widespread and broadly successful strategy for animals to exploit periodic and localized resources over large spatial scales. It remains an open and largely case-specific question whether long-distance migrations are resilient to environmental disruptions. High levels of mobility suggest an ability to shift ranges that can confer resilience. On the other hand, a conservative, hard-wired commitment to a risky behavior can be costly if conditions change. Mechanisms that contribute to migration include identification and responsiveness to resources, sociality, and cognitive processes such as spatial memory and learning. Our goal was to explore the extent to which these factors interact not only to maintain a migratory behavior but also to provide resilience against environmental changes. We develop a diffusion-advection model of animal movement in which an endogenous migratory behavior is modified by recent experiences via a memory process, and animals have a social swarming-like behavior over a range of spatial scales. We found that this relatively simple framework was able to adapt to a stable, seasonal resource dynamic under a broad range of parameter values. Furthermore, the model was able to acquire an adaptive migration behavior with time. However, the resilience of the process depended on all the parameters under consideration, with many complex trade-offs. For example, the spatial scale of sociality needed to be large enough to capture changes in the resource, but not so large that the acquired collective information was overly diluted. A long-term reference memory was important for hedging against a highly stochastic process, but a higher weighting of more recent memory was needed for adapting to directional changes in resource phenology. Our model provides a general and versatile framework for exploring the interaction of memory, movement, social and resource dynamics, even as environmental conditions globally are undergoing rapid change.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Great Plains ◽  
Life Histories ◽  
Environmental Heterogeneity ◽  
Environmental Variability ◽  
Spatial Scales ◽  
Stream Fish ◽  
Metapopulation Dynamics ◽  
Stream Fishes ◽  
Spatial And Temporal Scales ◽  
Trade Offs

<em>Abstract</em>.—Stream fishes carry out their life histories across broad spatial and temporal scales, leading to spatially structured populations. Therefore, incorporating metapopulation dynamics into models of stream fish populations may improve our ability to understand mechanisms regulating them. First, we reviewed empirical research on metapopulation dynamics in the stream fish ecology literature and found 31 papers that used the metapopulation framework. The majority of papers applied no specific metapopulation model, or included space only implicitly. Although parameterization of spatially realistic models is challenging, we suggest that stream fish ecologists should incorporate space into models and recognize that metapopulation types may change across scales. Second, we considered metacommunity theory, which addresses how trade-offs among dispersal, environmental heterogeneity, and biotic interactions structure communities across spatial scales. There are no explicit tests of metacommunity theory using stream fishes to date, so we used data from our research in a Great Plains stream to test the utility of these paradigms. We found that this plains fish metacommunity was structured mainly by spatial factors related to dispersal opportunity and, to a lesser extent, by environmental heterogeneity. Currently, metacommunity models are more heuristic than predictive. Therefore, we propose that future stream fish metacommunity research should focus on developing testable hypotheses that incorporate stream fish life history attributes, and seasonal environmental variability, across spatial scales. This emerging body of research is likely to be valuable not only for basic stream fish ecological research, but also multispecies conservation and management.

Circadian Rhythms and Homeostatic Mechanisms for Sleep Regulation

2021 ◽  
pp. 65-86
Author(s):  
Cassie J. Hilditch ◽  
Erin E. Flynn-Evans
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Process Model ◽  
Modern Society ◽  
Current Evidence ◽  
Sleep Regulation ◽  
Sleep Homeostasis ◽  
Short And Long Term ◽  
Homeostatic Mechanisms

This chapter examines circadian rhythms and homeostatic mechanisms for sleep regulation. It reviews the current evidence describing the two-process model of sleep regulation and how to assess disruption to either of these sleep drives. This chapter also reviews the role of the photic and non-photic resetting of the circadian rhythm and describes how some aspects of modern society can cause sleep and circadian disruption. Further, this chapter describes how misalignment between the circadian rhythm and sleep homeostasis, such as occurs during jet lag and shift-work, can lead to sleep disruption. The short- and long-term consequences of circadian misalignment are also reviewed.

Influence of historical and contemporary habitat changes on the population genetics of the endemic South African parrot Poicephalus robustus

2019 ◽  
Vol 30 (2) ◽  
pp. 236-259
Author(s):  
WILLEM G. COETZER ◽  
COLLEEN T. DOWNS ◽  
MIKE R. PERRIN ◽  
SANDI WILLOWS-MUNRO
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Spatial Scales ◽  
Population Decline ◽  
Source Population ◽  
Population Bottlenecks ◽  
Eastern Cape ◽  
Forest Patches ◽  
In The Wild ◽  
Fragmented Forests

SummaryThe Cape Parrot Poicephalus robustus is a habitat specialist, restricted to forest patches in the Eastern Cape (EC), KwaZulu-Natal (KZN) and Limpopo provinces of South Africa. Recent census estimates suggest that there are less than 1,600 parrots left in the wild, although historical data suggest that the species was once more numerous. Fragmentation of the forest biome is strongly linked to climate change and exploitation of the forest by the timber industry. We examine the subpopulation structure and connectivity between fragmented populations across the distribution of the species. Differences in historical and contemporary genetic structure of Cape Parrots is examined by including both modern samples, collected from 1951 to 2014, and historical samples, collected from 1870 to 1946. A total of 114 individuals (historical = 29; contemporary = 85) were genotyped using 16 microsatellite loci. We tested for evidence of partitioning of genotypes at both a temporal and spatial scales by comparing shifts in allelic frequencies of historical (1870–1946) and contemporary (1951–2014) samples across the distribution of the species. Tests for population bottlenecks were also conducted to determine if anthropogenic causes are the main driver of population decline in this species. Analyses identified three geographically correlated genetic clusters. A southern group restricted to forest patches in the EC, a central group including birds from KZN and a genetically distinct northern Limpopo cluster. Results suggest that Cape Parrots have experienced at least two population bottlenecks. An ancient decline during the mid-Holocene (∼ 1,800-3,000 years before present) linked to climate change, and a more recent bottleneck, associated with logging of forests during the early 1900s. This study highlights the effects of climate change and human activities on an endangered species associated with the naturally fragmented forests of eastern South Africa. These results will aid conservation authorities with the planning and implementation of future conservation initiatives. In particular, this study emphasises the Eastern Cape mistbelt forests as an important source population for the species and calls for stronger conservation of forest patches in South Africa to promote connectivity of forest taxa.

scholarly journals Sleep Homeostasis and the Function of Sleep—Comments

SLEEP ◽  
2001 ◽  
Vol 24 (7) ◽  
pp. 750-750 ◽  
Author(s):  
R. V. Rial ◽  
M.C. Nicolau ◽  
S. Esteban ◽  
A. Gamundí ◽  
M. Akaârir
Keyword(s):  
Sleep Homeostasis ◽  
Function Of Sleep

scholarly journals Three Decades of Changes in Brazilian Municipalities and Their Food Production Systems

Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 422
Author(s):  
Ramon Felipe Bicudo da Silva ◽  
Mateus Batistella ◽  
James D. A. Millington ◽  
Emilio Moran ◽  
Luiz A. Martinelli ◽  
...  
Keyword(s):  
Food Production ◽  
Crop Production ◽  
Census Data ◽  
Production Systems ◽  
Statistical Tests ◽  
Spatial Scales ◽  
Farm Size ◽  
Socioeconomic Outcomes ◽  
Economic Output ◽  
Trade Offs

Agricultural systems are heterogeneous across temporal and spatial scales. Although much research has investigated farm size and economic output, the synergies and trade-offs across various agricultural and socioeconomic variables are unclear. This study applies a GIS-based approach to official Brazilian census data (Agricultural Censuses of 1995, 2006, and 2017) and surveys at the municipality level to (i) evaluate changes in the average soybean farm size across the country and (ii) compare agricultural and socioeconomic outcomes (i.e., soybean yield, agricultural production value, crop production diversity, and rural labor employment) relative to the average soybean farm size. Statistical tests (e.g., Kruskal–Wallis tests and Spearman’s correlation) were used to analyze variable outcomes in different classes of farm sizes and respective Agricultural Censuses. We found that agricultural and socioeconomic outcomes are spatially correlated with soybean farm size class. Therefore, based on the concepts of trade-offs and synergies, we show that municipalities with large soybean farm sizes had larger trade-offs (e.g., larger farm size was associated with lower crop diversity), while small and medium ones manifest greater synergies. These patterns are particularly strong for analysis using the Agricultural Census of 2017. Trade-off/synergy analysis across space and time is key for supporting long-term strategies aiming at alleviating unemployment and providing sustainable food production, essential to achieve the UN Sustainable Development Goals.

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