Objective: Self‐reported sleep disturbances are present in over 80% of patients with depression. However, sleep electroencephalography (EEG) findings, based on overnight polysomnography have not ...always differentiated depressed patients from healthy individuals.
Method: The present paper will review the findings on sleep EEG studies in depression highlighting how recent technological and methodological advances have impacted on study outcomes.
Results: The majority of studies, including our own work, do indicate that sleep homeostasis and sleep EEG rhythms are abnormal in depression, but the sleep disturbances were strongly moderated by gender and age. Melancholic features of depression correlated significantly with low slow‐wave activity in depressed men, but not in depressed women. Women with depression showed low temporal coherence of sleep EEG rhythms but the presence or absence of melancholic features did not influence correlations.
Conclusion: Diagnostic classification schemas and clinical features of depression may influence sleep EEG findings, but gender may be a more important consideration.
Landscape-level shifts in plant species distribution and abundance can fundamentally change the ecology of an ecosystem. Such shifts are occurring within mangrove-marsh ecotones, where over the last ...few decades, relatively mild winters have led to mangrove expansion into areas previously occupied by salt marsh plants. On the Texas (USA) coast of the western Gulf of Mexico, most cases of mangrove expansion have been documented within specific bays or watersheds. Based on this body of relatively small-scale work and broader global patterns of mangrove expansion, we hypothesized that there has been a recent regional-level displacement of salt marshes by mangroves. We classified Landsat-5 Thematic Mapper images using artificial neural networks to quantify black mangrove (Avicennia germinans) expansion and salt marsh (Spartina alterniflora and other grass and forb species) loss over 20 years across the entire Texas coast. Between 1990 and 2010, mangrove area grew by 16.1 km(2), a 74% increase. Concurrently, salt marsh area decreased by 77.8 km(2), a 24% net loss. Only 6% of that loss was attributable to mangrove expansion; most salt marsh was lost due to conversion to tidal flats or water, likely a result of relative sea level rise. Our research confirmed that mangroves are expanding and, in some instances, displacing salt marshes at certain locations. However, this shift is not widespread when analyzed at a larger, regional level. Rather, local, relative sea level rise was indirectly implicated as another important driver causing regional-level salt marsh loss. Climate change is expected to accelerate both sea level rise and mangrove expansion; these mechanisms are likely to interact synergistically and contribute to salt marsh loss.
The carbon sequestration potential in coastal soils is linked to aboveground and belowground plant productivity and biomass, which in turn, is directly and indirectly influenced by nutrient input. We ...evaluated the influence of long-term and near-term nutrient input on aboveground and belowground carbon accumulation in seagrass beds, using a nutrient enrichment (nitrogen and phosphorus) experiment embedded within a naturally occurring, long-term gradient of phosphorus availability within Florida Bay (USA). We measured organic carbon stocks in soils and above- and belowground seagrass biomass after 17 months of experimental nutrient addition. At the nutrient-limited sites, phosphorus addition increased the carbon stock in aboveground seagrass biomass by more than 300 %; belowground seagrass carbon stock increased by 50–100 %. Soil carbon content slightly decreased ( ∼ 10 %) in response to phosphorus addition. There was a strong but non-linear relationship between soil carbon and Thalassia testudinum leaf nitrogen : phosphorus (N : P) or belowground seagrass carbon stock. When seagrass leaf N : P exceeded an approximate threshold of 75 : 1, or when belowground seagrass carbon stock was less than 100 g m−2, there was less than 3 % organic carbon in the sediment. Despite the marked difference in soil carbon between phosphorus-limited and phosphorus-replete areas of Florida Bay, all areas of the bay had relatively high soil carbon stocks near or above the global median of 1.8 % organic carbon. The relatively high carbon content in the soils indicates that seagrass beds have extremely high carbon storage potential, even in nutrient-limited areas with low biomass or productivity.
Adaptive Comanagement Plummer, Ryan; Crona, Beatrice; Armitage, Derek R. ...
Ecology and society,
09/2012, Letnik:
17, Številka:
3
Journal Article
Recenzirano
Odprti dostop
This paper outlines the results of a systematic review of the literature on adaptive comanagement (ACM). Adaptive comanagement is an emergent governance approach for complex social–ecological systems ...that links the learning function of adaptive management (experimental and experiential) and the linking (vertically and horizontally) function of comanagement. Given the rapid growth of adaptive comanagement scholarship, there is value in a systematic analysis of how the concept is being conceptualized to elucidate agreement and discrepancies and to examine the challenges this presents for cross-case comparisons and the possibility of arriving at more generalizable insights. A synthesis-based methodology has been developed involving a comprehensive search and screening of academic databases and the internet. A detailed analysis of 108 documents was undertaken to characterize the state of the ACM literature, unpack the construct of ACM, and examine relationships among aspects of ACM based on accumulated experiences to date. The systematic review and analysis reveals imprecision, inconsistency, and confusion with the concept. Robust evidentiary insights into how the variables or components of ACM interrelate as well as relate to goals and outcomes are, therefore, presently not possible. These findings lead to the discussion of a series of challenges for ACM scholarship. Opportunities remain for ACM scholars to pursue theoretical development in rigorous ways that facilitate empirically based cross-site comparisons.
This study empirically investigates the influence of bridging organizations on governance outcomes for marine conservation in Indonesia. Conservation challenges require ways of governing that are ...collaborative and adaptive across boundaries, and where conservation actions are better coordinated, information flows improved, and knowledge better integrated and mobilized. We combine quantitative social network analysis and qualitative data to analyze bridging organizations and their networks, and to understand their contributions and constraints in two case studies in Bali, Indonesia. The analysis shows 1) bridging organizations help to navigate the 'messiness' inherent in conservation settings by compensating for sparse linkages, 2) the particular structure and function of bridging organizations influence governing processes (i.e., collaboration, knowledge sharing) and subsequent conservation outcomes, 3) 'bridging' is accomplished using different strategies and platforms for collaboration and social learning, and 4) bridging organizations enhance flexibility to adjust to changing marine conservation contexts and needs. Understanding the organizations that occupy bridging positions, and how they utilize their positionality in a governance network is emerging as an important determinant of successful conservation outcomes. Our findings contribute to a relatively new body of literature on bridging organizations in marine conservation contexts, and add needed empirical investigation into their value to governance and conservation in Coral Triangle nations and beyond.
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