721 research outputs found
Water temperature dynamics in High Arctic river basins
Despite the high sensitivity of polar regions to climate change and the strong influence of temperature upon ecosystem processes, contemporary understanding of water temperature dynamics in Arctic river systems is limited. This research gap was addressed by exploring high-resolution water column thermal regimes for glacier-fed and non-glacial rivers at eight sites across Svalbard during the 2010 melt season. Mean water column temperatures in glacier-fed rivers (0.3-3.2 °C) were lowest and least variable near the glacier terminus but increased downstream (0.7-2.3 °C km ). Non-glacial rivers, where discharge was sourced primarily from snowmelt runoff, were warmer (mean: 2.9-5.7 °C) and more variable, indicating increased water residence times in shallow alluvial zones and increased potential for atmospheric influence. Mean summer water temperature and the magnitude of daily thermal variation were similar to those of some Alaskan Arctic rivers but low at all sites when compared with alpine glacierized environments at lower latitudes. Thermal regimes were correlated strongly (p<0.01) with incoming short-wave radiation, air temperature, and river discharge. Principal drivers of thermal variability were inferred to be (i) water source (i.e. glacier melt, snowmelt, groundwater); (ii) exposure time to the atmosphere; (iii) prevailing meteorological conditions; (iv) river discharge; (v) runoff interaction with permafrost and buried ice; and (vi) basin-specific geomorphological features (e.g. channel morphology). These results provide insight into the potential changes in high-latitude river systems in the context of projected warming in polar regions. We hypothesize that warmer and more variable temperature regimes may prevail in the future as the proportion of bulk discharge sourced from glacial meltwater declines and rivers undergo a progressive shift towards snow water and groundwater sources. Importantly, such changes could have implications for aquatic species diversity and abundance and influence rates of ecosystem functioning in high-latitude river systems
Religious Relationships with the Environment in a Tibetan Rural Community: Interactions and Contrasts with Popular Notions of Indigenous Environmentalism
Representations of Green Tibetans connected to Buddhism and indigenous wisdom have been deployed by a variety of actors and persist in popular consciousness. Through interviews, participatory mapping and observation, we explored how these ideas relate to people's notions about the natural environment in a rural community on the Eastern Tibetan plateau, in Sichuan Province, China. We found people to be orienting themselves towards the environment by means of three interlinked religious notions: (1) local gods and spirits in the landscape, which have become the focus of conservation efforts in the form of 'sacred natural sites;' (2) sin and karma related to killing animals and plants; (3) Buddhist moral precepts especially non-violence. We highlight the gaps between externally generated representations and local understandings, but also the dynamic, contested and plural nature of local relationships with the environment, which have been influenced and reshaped by capitalist development and commodification of natural resources, state environmental policies, and Buddhist modernist ideas
Microform-scale variations in peatland permeability and their ecohydrological implications
1. The acrotelm-catotelm model of peatland hydrological and biogeochemical processes posits that the permeability of raised bogs is largely homogenous laterally but varies strongly with depth
through the soil profile; uppermost peat layers are highly permeable while deeper layers are, effectively, impermeable.
2. We measured down-core changes in peat permeability, plant macrofossil assemblages, dry bulk density and degree of humification beneath two types of characteristic peatland microform – ridges
and hollows – at a raised bog in Wales. Six 1424 C dates were also collected for one hollow and an adjacent ridge. 3. Contrary to the acrotelm-catotelm model, we found that deeper peat can be as highly permeable as near-surface peat and that its permeability can vary by more than an order of magnitude between microforms over horizontal distances of 1-5 metres. 4. Our palaeo-ecological data paint a complicated picture of microform persistence. Some microforms can remain in the same position on a bog for millennia, growing vertically upwards as the bog grows. However, adjacent areas on the bog (< 10 m distant) show switches between microform type over time, indicating a lack of persistence. 5. Synthesis. We suggest that the acrotelm-catotelm model should be used cautiously; spatial variations in peatland permeability do not fit the simple patterns suggested by the model. To understand how peatlands as a whole function both hydrologically and ecologically it is necessary to understand how patterns of peat physical properties and peatland vegetation develop and persist
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Cooperative Carbon Dioxide Adsorption in Alcoholamine- and Alkoxyalkylamine-Functionalized Metal-Organic Frameworks.
A series of structurally diverse alcoholamine- and alkoxyalkylamine-functionalized variants of the metal-organic framework Mg2 (dobpdc) are shown to adsorb CO2 selectively via cooperative chain-forming mechanisms. Solid-state NMR spectra and optimized structures obtained from van der Waals-corrected density functional theory calculations indicate that the adsorption profiles can be attributed to the formation of carbamic acid or ammonium carbamate chains that are stabilized by hydrogen bonding interactions within the framework pores. These findings significantly expand the scope of chemical functionalities that can be utilized to design cooperative CO2 adsorbents, providing further means of optimizing these powerful materials for energy-efficient CO2 separations
Flow intermittence in river networks: understanding the ecohydrological diversity of aquatic–terrestrial ecosystems
Temporary streams comprise dynamic mosaics of lotic, lentic and terrestrial habitats and dominate global river networks, occurring across regions with contrasting climate types. Recent advances in our ecohydrological understanding of temporary streams have focused on systems in arid, semi-arid and mediterranean climates. In this special issue, we present new temporary stream research from underrepresented regions, primarily cool, wet temperate climates but also continental central Europe and the mediterranean-climate region of South Africa. We bring together observational case studies, laboratory experiments, and field surveys spanning surface water and groundwater habitats. Papers within the special issue explore ecological responses to flow intermittence; examine biodiversity patterns of rare and endemic species at broad spatial scales; characterize diverse responses to drying events within and among populations; demonstrate the value of long-term observational data in understanding the hydrological drivers that underpin biotic responses; and present opportunities to improve temporary stream monitoring and management. Collectively, these contributions complement dryland research to advance global understanding of temporary stream ecohydrology. However, the terrestrial communities that inhabit dry channels remain a notable research gap, which we address in a review of global literature. As global change causes an increase in their extent across climate regions, we urge researchers and stakeholders to collaborate to implement recommendations that address the challenges associated with the effective management of temporary streams as aquatic–terrestrial ecosystems
The NEWMEDS rodent touchscreen test battery for cognition relevant to schizophrenia.
RATIONALE: The NEWMEDS initiative (Novel Methods leading to New Medications in Depression and Schizophrenia, http://www.newmeds-europe.com ) is a large industrial-academic collaborative project aimed at developing new methods for drug discovery for schizophrenia. As part of this project, Work package 2 (WP02) has developed and validated a comprehensive battery of novel touchscreen tasks for rats and mice for assessing cognitive domains relevant to schizophrenia. OBJECTIVES: This article provides a review of the touchscreen battery of tasks for rats and mice for assessing cognitive domains relevant to schizophrenia and highlights validation data presented in several primary articles in this issue and elsewhere. METHODS: The battery consists of the five-choice serial reaction time task and a novel rodent continuous performance task for measuring attention, a three-stimulus visual reversal and the serial visual reversal task for measuring cognitive flexibility, novel non-matching to sample-based tasks for measuring spatial working memory and paired-associates learning for measuring long-term memory. RESULTS: The rodent (i.e. both rats and mice) touchscreen operant chamber and battery has high translational value across species due to its emphasis on construct as well as face validity. In addition, it offers cognitive profiling of models of diseases with cognitive symptoms (not limited to schizophrenia) through a battery approach, whereby multiple cognitive constructs can be measured using the same apparatus, enabling comparisons of performance across tasks. CONCLUSION: This battery of tests constitutes an extensive tool package for both model characterisation and pre-clinical drug discovery.This work was supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 115008 of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013). The authors thank Charlotte Oomen for valuable comments on the manuscript.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4007-
Multivariable regression analysis in Schistosoma mansoni-infected individuals in the Sudan reveals unique immunoepidemiological profiles in uninfected, egg+ and non-egg+ infected individuals
Background: In the Sudan, Schistosoma mansoni infections are a major cause of morbidity in schoolaged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity.
Methodology: This retrospective study evaluated immunoepidemiological aspects in 234 individuals(range 4–85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles(cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis.
Principal Findings: Nearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis.
Conclusions/Significance: Schistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways/mechanisms of IL-2 and IL-1β as potential diagnostic markers in order to distinguish patent from non-patent individuals
Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies
The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes
Unexpected mitochondrial genome diversity revealed by targeted single-cell genomics of heterotrophic flagellated protists
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData availability:
Complete mtDNA sequences assembled from this study are available at GenBank under the accession numbers MK188935 to MK188947, MN082144 and MN082145. Sequencing data are available under NCBI BioProject PRJNA379597. Reads have been deposited at NCBI Sequence Read Archive with accession number SRP102236. Partial mtDNA contigs and other important contigs mentioned in the text are available from Figshare at https://doi.org/10.6084/m9.figshare.7314728. Nuclear SAG assemblies are available from Figshare at https://doi.org/10.6084/m9.figshare.7352966. A protocol is available from protocols.io at: https://doi.org/10.17504/protocols.io.ywpfxdn.Code availability:
The bioinformatic workflow is available at https://doi.org/10.5281/zenodo.192677; additional statistical analysis code is available at https://doi.org/10.6084/m9.figshare.9884309.Most eukaryotic microbial diversity is uncultivated, under-studied and lacks nuclear genome data. Mitochondrial genome sampling is more comprehensive, but many phylogenetically important groups remain unsampled. Here, using a single-cell sorting approach combining tubulin-specific labelling with photopigment exclusion, we sorted flagellated heterotrophic unicellular eukaryotes from Pacific Ocean samples. We recovered 206 single amplified genomes, predominantly from underrepresented branches on the tree of life. Seventy single amplified genomes contained unique mitochondrial contigs, including 21 complete or near-complete mitochondrial genomes from formerly under-sampled phylogenetic branches, including telonemids, katablepharids, cercozoans and marine stramenopiles, effectively doubling the number of available samples of heterotrophic flagellate mitochondrial genomes. Collectively, these data identify a dynamic history of mitochondrial genome evolution including intron gain and loss, extensive patterns of genetic code variation and complex patterns of gene loss. Surprisingly, we found that stramenopile mitochondrial content is highly plastic, resembling patterns of variation previously observed only in plants.Gordon and Betty Moore FoundationLeverhulme TrustDavid and Lucile Packard FoundationRoyal SocietyEuropean Molecular Biology OrganizationCONICYT FONDECYTGenome Canad
Supporting conservationists’ mental health through better working conditions
Biodiversity conservation work can be challenging but rewarding, with potential consequences for conservationists’ mental health. Yet, little is known about patterns of mental health among conservationists and its associated workplace protective and risk factors. A better understanding might help improve working conditions, supporting conservationists’ job satisfaction, productivity, and engagement, while reducing costs from staff turnover, absenteeism, and presenteeism. We surveyed 2311 conservation professionals working across 122 countries, asking about experiences of psychological distress, working conditions, and personal characteristics. Over half were from and worked in Europe and North America, and most had university-level education, were in desk-based academic and practitioner roles, and responded in English. Heavy workload, job demands, and organizational instability were linked to higher distress, but job stability and satisfaction with one's contributions to conservation were associated with lower distress. Respondents with low dispositional and conservation-specific optimism, poor physical health, limited social support, women, and early-career professionals were most at risk in our sample. Our results flag important risk factors that employers could consider, though further research is needed among groups under-represented in our sample. We suggest ways employers and others might promote the positives and manage the risks of working in the sector, potentially supporting conservationists’ mental health and abilities to protect nature
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