250 research outputs found
A proteomic signature for CNS adaptations to the valence of environmental stimulation
Environmental Enrichment leads to a significant improvement in long-term performance across a range of cognitive functions in mammals and it has been shown to produce an increased synaptic density and neurogenesis. Nevertheless it is still an open question as to whether some key aspects of spatial learning & memory and procedural learning might be embodied by different molecular pathways to those of social cognition. Associated with synaptic changes and potentially underlying conditions, the Ras-ERK pathway has been proposed to be the primary mediator of in vivo adaptations to environmental enrichment, acting via the downstream Ras-ERK signalling kinase MSK1 and the transcription factor CREB. Herein, we show that valence of environmental stimulation increased social competition and that this is associated with a specific proteomic signature in the frontal lobe but notably not in the hippocampus. Specifically, we show that altering the valence of environmental stimuli affected the level of social competition, with mice from negatively enriched environments winning significantly more encountersâeven though mice from positive were bigger and should display dominance. This behavioural phenotype was accompanied by changes in the proteome of the fronto-ventral pole of the brain, with a differential increase in the relative abundance of proteins involved in the mitochondrial metabolic processes of the TCA cycle and respiratory processes. Investigation of this proteomic signature may pave the way for the elucidation of novel pathways underpinning the behavioural changes caused by negative enrichment and further out understanding of conditions whose core feature is increased social competition
ACE-ASIA - Regional climatic and atmospheric chemical effects of Asian dust and pollution
Although continental-scale plumes of Asian dust and pollution reduce the amount of solar radiation reaching the earth's surface and perturb the chemistry of the atmosphere, our ability to quantify these effects has been limited by a lack of critical observations, particularly of layers above the surface. Comprehensive surface, airborne, shipboard, and satellite measurements of Asian aerosol chemical composition, size, optical properties, and radiative impacts were performed during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) study. Measurements within a massive Chinese dust storm at numerous widely spaced sampling locations revealed the highly complex structure of the atmosphere, in which layers of dust, urban pollution, and biomass-burning smoke may be transported long distances as distinct entities or mixed together. The data allow a first-time assessment of the regional climatic and atmospheric chemical effects of a continental-scale mixture of dust and pollution. Our results show that radiative flux reductions during such episodes are sufficient to cause regional climate change
Self-supervised learning of accelerometer data provides new insights for sleep and its association with mortality
Sleep is essential to life. Accurate measurement and classification of sleep/wake and sleep stages is important in clinical studies for sleep disorder diagnoses and in the interpretation of data from consumer devices for monitoring physical and mental well-being. Existing non-polysomnography sleep classification techniques mainly rely on heuristic methods developed in relatively small cohorts. Thus, we aimed to establish the accuracy of wrist-worn accelerometers for sleep stage classification and subsequently describe the association between sleep duration and efficiency (proportion of total time asleep when in bed) with mortality outcomes. We developed a self-supervised deep neural network for sleep stage classification using concurrent laboratory-based polysomnography and accelerometry. After exclusion, 1448 participant nights of data were used for training. The difference between polysomnography and the model classifications on the external validation was 34.7âmin (95% limits of agreement (LoA): â37.8â107.2âmin) for total sleep duration, 2.6âmin for REM duration (95% LoA: â68.4â73.4âmin) and 32.1âmin (95% LoA: â54.4â118.5âmin) for NREM duration. The sleep classifier was deployed in the UK Biobank with 100,000 participants to study the association of sleep duration and sleep efficiency with all-cause mortality. Among 66,214 UK Biobank participants, 1642 mortality events were observed. Short sleepers (<6âh) had a higher risk of mortality compared to participants with normal sleep duration of 6â7.9âh, regardless of whether they had low sleep efficiency (Hazard ratios (HRs): 1.58; 95% confidence intervals (CIs): 1.19â2.11) or high sleep efficiency (HRs: 1.45; 95% CIs: 1.16â1.81). Deep-learning-based sleep classification using accelerometers has a fair to moderate agreement with polysomnography. Our findings suggest that having short overnight sleep confers mortality risk irrespective of sleep continuity
Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)
We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multi-model mean OH concentration is overestimated by 5 to 10% but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high northâsouth OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34%). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6%) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the change in global mean tropospheric CO and NOx burdens (ÎCO/ÎNOx, approximately represents changes in OH sinks versus changes in OH sources) in the models, pointing to a need for better constraints on natural precursor emissions and on the chemical mechanisms in the current generation of chemistry-climate models. For the 1980 to 2000 period, we find that climate warming and a slight increase in mean OH (3.5 ± 2.2%) leads to a 4.3 ± 1.9% decrease in the methane lifetime. Analysing sensitivity simulations performed by 10 models, we find that preindustrial to present-day climate change decreased the methane lifetime by about four months, representing a negative feedback on the climate system. Further, we analysed attribution experiments performed by a subset of models relative to 2000 conditions with only one precursor at a time set to 1860 levels. We find that global mean OH increased by 46.4 ± 12.2% in response to preindustrial to present-day anthropogenic NOx emission increases, and decreased by 17.3 ± 2.3%, 7.6 ± 1.5%, and 3.1 ± 3.0% due to methane burden, and anthropogenic CO, and NMVOC emissions increases, respectively
Functional Correlations of Pathogenesis-Driven Gene Expression Signatures in Tuberculosis
Tuberculosis remains a major health threat and its control depends on improved measures of prevention, diagnosis and treatment. Biosignatures can play a significant role in the development of novel intervention measures against TB and blood transcriptional profiling is increasingly exploited for their rational design. Such profiles also reveal fundamental biological mechanisms associated with the pathology of the disease. We have compared whole blood gene expression in TB patients, as well as in healthy infected and uninfected individuals in a cohort in The Gambia, West Africa and validated previously identified signatures showing high similarities of expression profiles among different cohorts. In this study, we applied a unique combination of classical gene expression analysis with pathway and functional association analysis integrated with intra-individual expression correlations. These analyses were employed for identification of new disease-associated gene signatures, identifying a network of Fc gamma receptor 1 signaling with correlating transcriptional activity as hallmark of gene expression in TB. Remarkable similarities to characteristic signatures in the autoimmune disease systemic lupus erythematosus (SLE) were observed. Functional gene clusters of immunoregulatory interactions involving the JAK-STAT pathway; sensing of microbial patterns by Toll-like receptors and IFN-signaling provide detailed insights into the dysregulation of critical immune processes in TB, involving active expression of both pro-inflammatory and immunoregulatory systems. We conclude that transcriptomics (i) provides a robust system for identification and validation of biosignatures for TB and (ii) application of integrated analysis tools yields novel insights into functional networks underlying TB pathogenesis
Mismatches in scale between highly mobile marine megafauna and marine protected areas
Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe in part to facilitate the conservation of marine megafauna under the assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen to reflect the span of home range size in highly mobile marine megafauna, we show most MPAs are too small to encompass complete home ranges of most species. Based on size alone, 40% of existing MPAs could encompass the home ranges of the smallest ranged species, while only < 1% of existing MPAs could encompass those of the largest ranged species. Further, where home ranges and MPAs overlapped in real geographic space, MPAs encompassed < 5% of core areas used by all species. Despite most home ranges of mobile marine megafauna being much larger than existing MPAs, we demonstrate how benefits from MPAs are still likely to accrue by targeting seasonal aggregations and critical life history stages and through other management techniques.Fil: Conners, Melinda G.. University of Washington; Estados Unidos. State University of New York. Stony Brook University; Estados UnidosFil: Sisson, Nicholas B.. Old Dominion University; Estados UnidosFil: Agamboue, Pierre D.. Wildlife Conservation Society; GabĂłnFil: Atkinson, Philip W.. British Trust For Ornithology; Reino UnidoFil: Baylis, Alastair M. M.. Macquarie University; Australia. South Atlantic Environmental Research Institute; Reino UnidoFil: Benson, Scott R.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados Unidos. Moss Landing Marine Laboratories; Estados UnidosFil: Block, Barbara A.. University of Stanford; Estados UnidosFil: Bograd, Steven J.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Bordino, Pablo. Mote Marine Laboratory; Estados UnidosFil: Bowen, W.D.. Bedford Institute Of Oceanography, Fisheries And Oceans Canada; CanadĂĄ. Dalhousie University Halifax; CanadĂĄFil: Brickle, Paul. South Atlantic Environmental Research Institute; Reino Unido. University of Aberdeen; Reino Unido. University Of Aberdeeen; Reino UnidoFil: Bruno, Ignacio Matias. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: GonzĂĄlez Carman, Victoria. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Champagne, Cory D.. University of Washington; Estados UnidosFil: Crocker, Daniel E.. Sonoma State University; Estados UnidosFil: Costa, Daniel P.. University of California; Estados UnidosFil: Dawson, Tiffany M.. University Of Central Florida; Estados Unidos. Old Dominion University; Estados UnidosFil: Deguchi, Tomohiro. Yamashina Institute For Ornithology; JapĂłnFil: Dewar, Heidi. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Doherty, Philip D.. University of Exeter; Reino UnidoFil: Eguchi, Tomo. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Formia, Angela. Wildlife Conservation Society; GabĂłn. African Aquatic Conservation Fund; Estados UnidosFil: Godley, Brendan J.. University of Exeter; Reino UnidoFil: Graham, Rachel T.. Maralliance; PanamĂĄFil: Gredzens, Christian. Padre Island National Seashore; Estados UnidosFil: Hart, Kristen M.. United States Geological Survey; Estados UnidosFil: Hawkes, Lucy A.. University of Exeter; Reino UnidoFil: Henderson, Suzanne. Scottish Natural Heritage; Reino UnidoFil: Henry, Robert William. Groundswell Coastal Ecology; Estados UnidosFil: HĂŒckstĂ€dt, Luis A.. University of Exeter; Reino Unido. University of California; Estados Unido
Comparing nuclear power trajectories in Germany and the UK: from âregimes' to âdemocraciesâ in sociotechnical transitions and Discontinuities
This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ânuclear renaissanceâ, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field ofâsustainability transitionsâ. To this end, an âabductiveâ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are âinternalâ and âexternalâ to the âfocal regime configurationâ of nuclear power and associated âchallenger technologiesâ like renewables.
It is âinternalâ criteria that are emphasised in conventional sociotechnical regime theory, with âexternalâ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. âInternalâ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germanyâ the reverse of what is occurring.
âExternalâ criteria are more aligned with observed dynamics âespecially those relating to military nuclear commitments and broader âqualities of democracyâ. Despite many differences of framing concerning exactly what constitutes âdemocracyâ, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitmentsâ whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability
ADAM22/LGI1 complex as a new actionable target for breast cancer brain metastasis
Background: Metastatic breast cancer is a major cause of cancer-related deaths in woman. Brain metastasis is a common and devastating site of relapse for several breast cancer molecular subtypes, including oestrogen receptor-positive disease, with life expectancy of less than a year. While efforts have been devoted to developing therapeutics for extra-cranial metastasis, drug penetration of bloodâbrain barrier (BBB) remains a major clinical challenge. Defining molecular alterations in breast cancer brain metastasis enables the identification of novel actionable targets.Methods: Global transcriptomic analysis of matched primary and metastatic patient tumours (nâ=â35 patients, 70 tumour samples) identified a putative new actionable target for advanced breast cancer which was further validated in vivo and in breast cancer patient tumour tissue (nâ=â843 patients). A peptide mimetic of the target's natural ligand was designed in silico and its efficacy assessed in in vitro, ex vivo and in vivo models of breast cancer metastasis.Results: Bioinformatic analysis of over-represented pathways in metastatic breast cancer identified ADAM22 as a top ranked member of the ECM-related druggable genome specific to brain metastases. ADAM22 was validated as an actionable target in in vitro, ex vivo and in patient tumour tissue (nâ=â843 patients). A peptide mimetic of the ADAM22 ligand LGI1, LGI1MIM, was designed in silico. The efficacy of LGI1MIM and its ability to penetrate the BBB were assessed in vitro, ex vivo and in brain metastasis BBB 3D biometric biohybrid models, respectively. Treatment with LGI1MIM in vivo inhibited disease progression, in particular the development of brain metastasis.Conclusion: ADAM22 expression in advanced breast cancer supports development of breast cancer brain metastasis. Targeting ADAM22 with a peptide mimetic LGI1MIM represents a new therapeutic option to treat metastatic brain disease
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Reconstructing promoter activity from Lux bioluminescent reporters
The bacterial Lux system is used as a gene expression reporter. It is fast, sensitive and non-destructive, enabling high frequency measurements. Originally developed for bacterial cells, it has also been adapted for eukaryotic cells, and can be used for whole cell biosensors, or in real time with live animals without the need for euthanasia. However, correct interpretation of bioluminescent data is limited: the bioluminescence is different from gene expression because of nonlinear molecular and enzyme dynamics of the Lux system. We have developed a computational approach that, for the first time, allows users of Lux assays to infer gene transcription levels from the light output. This approach is based upon a new mathematical model for Lux activity, that includes the actions of LuxAB, LuxEC and Fre, with improved mechanisms for all reactions, as well as synthesis and turn-over of Lux proteins. The model is calibrated with new experimental data for the LuxAB and Fre reactions from Photorhabdus luminescens --- the source of modern Lux reporters --- while literature data has been used for LuxEC. Importantly, the data show clear evidence for previously unreported product inhibition for the LuxAB reaction. Model simulations show that predicted bioluminescent profiles can be very different from changes in gene expression, with transient peaks of light output, very similar to light output seen in some experimental data sets. By incorporating the calibrated model into a Bayesian inference scheme, we can reverse engineer promoter activity from the bioluminescence. We show examples where a decrease in bioluminescence would be better interpreted as a switching off of the promoter, or where an increase in bioluminescence would be better interpreted as a longer period of gene expression. This approach could benefit all users of Lux technology
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