| 1. |
- Arndt, D. S., et al.
(författare)
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State of the Climate in 2016
- 2017
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 98:8, s. S1-S280
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Tidskriftsartikel (refereegranskat)abstract
- In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
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| 2. |
- Steele, A., et al.
(författare)
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A Reduced Organic Carbon Component in Martian Basalts
- 2012
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 337:6091, s. 212-215
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Tidskriftsartikel (refereegranskat)abstract
- The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life.
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| 3. |
- Barrenäs, Fredrik, et al.
(författare)
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Interleukin-15 response signature predicts RhCMV/SIV vaccine efficacy
- 2021
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 17:7
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Tidskriftsartikel (refereegranskat)abstract
- Simian immunodeficiency virus (SIV) challenge of rhesus macaques (RMs) vaccinated with strain 68-1 Rhesus Cytomegalovirus (RhCMV) vectors expressing SIV proteins (RhCMV/SIV) results in a binary outcome: stringent control and subsequent clearance of highly pathogenic SIV in similar to 55% of vaccinated RMs with no protection in the remaining 45%. Although previous work indicates that unconventionally restricted, SIV-specific, effector-memory (EM)-biased CD8(+) T cell responses are necessary for efficacy, the magnitude of these responses does not predict efficacy, and the basis of protection vs. non-protection in 68-1 RhCMV/SIV vector-vaccinated RMs has not been elucidated. Here, we report that 68-1 RhCMV/SIV vector administration strikingly alters the whole blood transcriptome of vaccinated RMs, with the sustained induction of specific immune-related pathways, including immune cell, toll-like receptor (TLR), inflammasome/cell death, and interleukin-15 (IL-15) signaling, significantly correlating with subsequent vaccine efficacy. Treatment of a separate RM cohort with IL-15 confirmed the central involvement of this cytokine in the protection signature, linking the major innate and adaptive immune gene expression networks that correlate with RhCMV/SIV vaccine efficacy. This change-from-baseline IL-15 response signature was also demonstrated to significantly correlate with vaccine efficacy in an independent validation cohort of vaccinated and challenged RMs. The differential IL-15 gene set response to vaccination strongly correlated with the pre-vaccination activity of this pathway, with reduced baseline expression of IL-15 response genes significantly correlating with higher vaccine-induced induction of IL-15 signaling and subsequent vaccine protection, suggesting that a robust de novo vaccine-induced IL-15 signaling response is needed to program vaccine efficacy. Thus, the RhCMV/SIV vaccine imparts a coordinated and persistent induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8(+) T cell function, that support the ability of vaccine-elicited unconventionally restricted CD8(+) T cells to mediate protection against SIV challenge.
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| 4. |
- Gommenginger, Christine, et al.
(författare)
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SEASTAR: A mission to study ocean submesoscale dynamics and small-scale atmosphere-ocean processes in coastal, shelf and polar seas
- 2019
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 6:JUL
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- High-resolution satellite images of ocean color and sea surface temperature reveal an abundance of ocean fronts, vortices and filaments at scales below 10 km but measurements of ocean surface dynamics at these scales are rare. There is increasing recognition of the role played by small scale ocean processes in ocean-atmosphere coupling, upper-ocean mixing and ocean vertical transports, with advanced numerical models and in situ observations highlighting fundamental changes in dynamics when scales reach 1 km. Numerous scientific publications highlight the global impact of small oceanic scales on marine ecosystems, operational forecasts and long-term climate projections through strong ageostrophic circulations, large vertical ocean velocities and mixed layer re-stratification. Small-scale processes particularly dominate in coastal, shelf and polar seas where they mediate important exchanges between land, ocean, atmosphere and the cryosphere e.g. freshwater, pollutants. As numerical models continue to evolve towards finer spatial resolution and increasingly complex coupled atmosphere-wave-ice-ocean systems, modern observing capability lags behind, unable to deliver the high-resolution synoptic measurements of total currents, wind vectors and waves needed to advance understanding, develop better parameterizations and improve model validations, forecasts and projections. SEASTAR is a satellite mission concept that proposes to directly address this critical observational gap with synoptic two-dimensional imaging of total ocean surface current vectors and wind vectors at 1 km resolution and coincident directional wave spectra. Based on major recent advances in squinted along-track Synthetic Aperture Radar interferometry, SEASTAR is an innovative, mature concept with unique demonstrated capabilities, seeking to proceed towards spaceborne implementation within Europe and beyond.
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| 5. |
- Camus, M. Florencia, et al.
(författare)
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Single Nucleotides in the mtDNA Sequence Modify Mitochondrial Molecular Function and Are Associated with Sex-Specific Effects on Fertility and Aging
- 2015
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 25:20, s. 2717-2722
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondria underpin energy conversion in eukaryotes. Their small genomes have been the subject of increasing attention, and there is evidence that mitochondrial genetic variation can affect evolutionary trajectories and shape the expression of life-history traits considered to be key human health indicators [1, 2]. However, it is not understood how genetic variation across a diminutive genome, which in most species harbors only about a dozen protein-coding genes, can exert broad-scale effects on the organisnnal phenotype [2, 3]. Such effects are particularly puzzling given that the mitochondrial genes involved are under strong evolutionary constraint and that mitochondrial gene expression is highly conserved across diverse taxa [4]. We used replicated genetic lines in the fruit fly, Drosophila melanogaster, each characterized by a distinct and naturally occurring mitochondrial haplotype placed alongside an isogenic nuclear background. We demonstrate that sequence variation within the mitochondria! DNA (mtDNA) affects both the copy number of mitochondrial genomes and patterns of gene expression across key mitochondrial protein-coding genes. In several cases, haplotype-mediated patterns of gene expression were gene-specific, even for genes from within the same transcriptional units. This invokes post-transcriptional processing of RNA in the regulation of mitochondrial genetic effects on organismal phenotypes. Notably, the haplotype-mediated effects on gene expression could be traced backward to the level of individual nucleotides and forward to sex-specific effects on fertility and longevity. Our study thus elucidates how small-scale sequence changes in the mitochondrial genome can achieve broad-scale regulation of health-related phenotypes and even contribute to sex-related differences in longevity.
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| 6. |
- Pereira, Laura M., et al.
(författare)
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From fAIrplay to climate wars : making climate change scenarios more dynamic, creative, and integrative
- 2021
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Ingår i: Ecology and Society. - 1708-3087. ; 26:4
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Tidskriftsartikel (refereegranskat)abstract
- Understanding possible climate futures that include carbon dioxide removal (CDR) and solar radiation modification (SRM) requires thinking not just about staying within the remaining carbon budget, but also about politics and people. However, despite growing interest in CDR and SRM, scenarios focused on these potential responses to climate change tend to exclude feedbacks between social and climate systems (a criticism applicable to climate change scenarios more generally). We adapted the Manoa Mash Up method to generate scenarios for CDR and SRM that were more integrative, creative, and dynamic. The method was modified to identify important branching points in which different choices in how to respond to climate change (feedbacks between climate and social dynamics) lead to a plurality of climate futures. An interdisciplinary group of participants imagined distant futures in which SRM or CDR develop into a major social-environmental force. Groups received other seeds of change, such as Universal Basic Income or China's Belt and Road Initiative, and surprises, such as permafrost collapse that grew to influence the course of events to 2100. Groups developed narratives describing pathways to the future and identified bifurcation points to generate families of branching scenarios. Four climate-social dynamics were identified: motivation to mitigate, moral hazard, social unrest, and trust in institutions. These dynamics could orient toward better or worse outcomes with SRM and CDR deployment (and mitigation and adaptation responses more generally) but are typically excluded from existing climate change scenarios. The importance of these dynamics could be tested through the inclusion of social-environmental feedbacks into integrated assessment models (IAM) exploring climate futures. We offer a step-by-step guide to the modified Manoa Mash-up method to generate more integrative, creative, and dynamic scenarios; reflect on broader implications of using this method for generating more dynamic scenarios for climate change research and policy; and provide examples of using the scenarios in climate policy communication, including a choose-your-own adventure game called Survive the Century (https://survivethecentury.net/), which was played by over 15,000 people in the first 2 weeks of launching.
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| 7. |
- Adl, Sina M., et al.
(författare)
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Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes
- 2019
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Ingår i: Journal of Eukaryotic Microbiology. - : WILEY. - 1066-5234 .- 1550-7408. ; 66:1, s. 4-119
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Tidskriftsartikel (refereegranskat)abstract
- This revision of the classification of eukaryotes follows that of Adl et al., 2012 [J. Euk. Microbiol. 59(5)] and retains an emphasis on protists. Changes since have improved the resolution of many nodes in phylogenetic analyses. For some clades even families are being clearly resolved. As we had predicted, environmental sampling in the intervening years has massively increased the genetic information at hand. Consequently, we have discovered novel clades, exciting new genera and uncovered a massive species level diversity beyond the morphological species descriptions. Several clades known from environmental samples only have now found their home. Sampling soils, deeper marine waters and the deep sea will continue to fill us with surprises. The main changes in this revision are the confirmation that eukaryotes form at least two domains, the loss of monophyly in the Excavata, robust support for the Haptista and Cryptista. We provide suggested primer sets for DNA sequences from environmental samples that are effective for each clade. We have provided a guide to trophic functional guilds in an appendix, to facilitate the interpretation of environmental samples, and a standardized taxonomic guide for East Asian users.
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| 8. |
- Collet, Julie M., et al.
(författare)
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Rapid evolution of the intersexual genetic correlation for fitness in Drosophila melanogaster
- 2016
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 70:4, s. 781-795
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Tidskriftsartikel (refereegranskat)abstract
- Sexual antagonism (SA) arises when male and female phenotypes are under opposing selection, yet genetically correlated. Until resolved, antagonism limits evolution toward optimal sex-specific phenotypes. Despite its importance for sex-specific adaptation and existing theory, the dynamics of SA resolution are not well understood empirically. Here, we present data from Drosophila melanogaster, compatible with a resolution of SA. We compared two independent replicates of the LHM population in which SA had previously been described. Both had been maintained under identical, controlled conditions, and separated for around 200 generations. Although heritabilities of male and female fitness were similar, the intersexual genetic correlation differed significantly, being negative in one replicate (indicating SA) but close to zero in the other. Using population sequencing, we show that phenotypic differences were associated with population divergence in allele frequencies at nonrandom loci across the genome. Large frequency changes were more prevalent in the population without SA and were enriched at loci mapping to genes previously shown to have sexually antagonistic relationships between expression and fitness. Our data suggest that rapid evolution toward SA resolution has occurred in one of the populations and open avenues toward studying the genetics of SA and its resolution.
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| 9. |
- D'Ovidio, Francesco, et al.
(författare)
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Frontiers in fine-scale in situ studies: Opportunities during the SWOT fast sampling phase
- 2019
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 6
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Forskningsöversikt (refereegranskat)abstract
- © 2019 Frontiers Media S. A. Conceived as a major new tool for climate studies, the Surface Water and Ocean Topography (SWOT) satellite mission will launch in late 2021 and will retrieve the dynamics of the oceans upper layer at an unprecedented resolution of a few kilometers. During the calibration and validation (CalVal) phase in 2022, the satellite will be in a 1- day-repeat fast sampling orbit with enhanced temporal resolution, sacrificing the spatial coverage. This is an ideal opportunity - unique for many years to come - to coordinate in situ experiments during the same period for a focused study of fine scale dynamics and their broader roles in the Earth system. Key questions to be addressed include the role of fine scales on the ocean energy budget, the connection between their surface and internal dynamics, their impact on plankton diversity, and their biophysical dynamics at the ice margin.
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| 10. |
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