| 1. |
- Saunois, Marielle, et al.
(författare)
-
The Global Methane Budget 2000–2017
- 2020
-
Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3516 .- 1866-3508. ; 12:3, s. 1561-1623
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Atmospheric emissions and concentrations of CH4 continue to increase, making CH4 the second most important human-influenced greenhouse gas in terms of climate forcing, after carbon dioxide (CO2). The relative importance of CH4 compared to CO2 depends on its shorter atmospheric lifetime, stronger warming potential, and variations in atmospheric growth rate over the past decade, the causes of which are still debated. Two major challenges in reducing uncertainties in the atmospheric growth rate arise from the variety of geographically overlapping CH4 sources and from the destruction of CH4 by short-lived hydroxyl radicals (OH). To address these challenges, we have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. Following Saunois et al. (2016), we present here the second version of the living review paper dedicated to the decadal methane budget, integrating results of top-down studies (atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up estimates (including process-based models for estimating land surface emissions and atmospheric chemistry, inventories of anthropogenic emissions, and data-driven extrapolations).For the 2008–2017 decade, global methane emissions are estimated by atmospheric inversions (a top-down approach) to be 576 Tg CH4 yr−1 (range 550–594, corresponding to the minimum and maximum estimates of the model ensemble). Of this total, 359 Tg CH4 yr−1 or ∼ 60 % is attributed to anthropogenic sources, that is emissions caused by direct human activity (i.e. anthropogenic emissions; range 336–376 Tg CH4 yr−1 or 50 %–65 %). The mean annual total emission for the new decade (2008–2017) is 29 Tg CH4 yr−1 larger than our estimate for the previous decade (2000–2009), and 24 Tg CH4 yr−1 larger than the one reported in the previous budget for 2003–2012 (Saunois et al., 2016). Since 2012, global CH4 emissions have been tracking the warmest scenarios assessed by the Intergovernmental Panel on Climate Change. Bottom-up methods suggest almost 30 % larger global emissions (737 Tg CH4 yr−1, range 594–881) than top-down inversion methods. Indeed, bottom-up estimates for natural sources such as natural wetlands, other inland water systems, and geological sources are higher than top-down estimates. The atmospheric constraints on the top-down budget suggest that at least some of these bottom-up emissions are overestimated. The latitudinal distribution of atmospheric observation-based emissions indicates a predominance of tropical emissions (∼ 65 % of the global budget, < 30∘ N) compared to mid-latitudes (∼ 30 %, 30–60∘ N) and high northern latitudes (∼ 4 %, 60–90∘ N). The most important source of uncertainty in the methane budget is attributable to natural emissions, especially those from wetlands and other inland waters.Some of our global source estimates are smaller than those in previously published budgets (Saunois et al., 2016; Kirschke et al., 2013). In particular wetland emissions are about 35 Tg CH4 yr−1 lower due to improved partition wetlands and other inland waters. Emissions from geological sources and wild animals are also found to be smaller by 7 Tg CH4 yr−1 by 8 Tg CH4 yr−1, respectively. However, the overall discrepancy between bottom-up and top-down estimates has been reduced by only 5 % compared to Saunois et al. (2016), due to a higher estimate of emissions from inland waters, highlighting the need for more detailed research on emissions factors. Priorities for improving the methane budget include (i) a global, high-resolution map of water-saturated soils and inundated areas emitting methane based on a robust classification of different types of emitting habitats; (ii) further development of process-based models for inland-water emissions; (iii) intensification of methane observations at local scales (e.g., FLUXNET-CH4 measurements) and urban-scale monitoring to constrain bottom-up land surface models, and at regional scales (surface networks and satellites) to constrain atmospheric inversions; (iv) improvements of transport models and the representation of photochemical sinks in top-down inversions; and (v) development of a 3D variational inversion system using isotopic and/or co-emitted species such as ethane to improve source partitioning.The data presented here can be downloaded from https://doi.org/10.18160/GCP-CH4-2019 (Saunois et al., 2020) and from the Global Carbon Project.
|
|
| 2. |
- Andrén, Lennart, 1946, et al.
(författare)
-
Diltiazem in hypertensive patients with type II diabetes mellitus.
- 1988
-
Ingår i: The American journal of cardiology. - : Elsevier BV. - 0002-9149. ; 62:11
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty-three patients with essential hypertension and diabetes mellitus type II were treated with the calcium antagonist diltiazem (120 to 180 mg twice daily). The mean dose was 307 mg/day. The study was a double-blind, placebo-controlled, crossover design. All measurements were performed 12 to 14 hours after drug intake. Blood pressure, heart rate and forearm blood flow were measured noninvasively. Platelet function was studied by measuring adenosine diphosphate-induced platelet aggregation and the platelet specific proteins, beta thromboglobulin and platelet factor 4. Thromboxane B2 formation in serum and the plasma concentration of diltiazem and its metabolites N-demethyldiltiazem, deacetyldiltiazem and N-demethyldeacetyldiltiazem were measured both during placebo and diltiazem treatment. Diabetic control was evaluated by following HbA1C, fasting blood glucose and urinary glucose. Diltiazem reduced both systolic and diastolic (supine and standing) blood pressure significantly. Forearm blood flow was significantly increased by 32%, p less than 0.05. Supine heart rate decreased significantly, while no such change was seen in the standing position. No significant changes were observed in platelet function during diltiazem treatment. There was no relation between the observed blood pressure reduction and the plasma concentration of diltiazem or its metabolites. A positive correlation between the change in heart rate and the metabolite N-demethyldeacetyldiltiazem was observed (r = 0.647, p = 0.005). Three patients were excluded during diltiazem treatment (skin exanthema, headache and atrial fibrillation) and 1 during placebo treatment (angina pectoris). No negative effect on diabetes control was observed. Thus, diltiazem could be used for treatment of hypertension in diabetic patients.
|
|
| 3. |
- Bahnan, Wael, et al.
(författare)
-
Spike-Dependent Opsonization Indicates Both Dose-Dependent Inhibition of Phagocytosis and That Non-Neutralizing Antibodies Can Confer Protection to SARS-CoV-2
- 2022
-
Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization correlate with the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies could influence monocyte-mediated immune functions and propose that non-neutralizing antibodies could confer protection to SARS-CoV-2 infection by mediating phagocytosis.
|
|
| 4. |
- Bednar, Johannes, et al.
(författare)
-
Role of removals in contributing to the long-term goals of the Paris Agreement
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report delves into the multifaceted dimensions of carbon dioxide removal methods. The report discusses the role of carbon dioxide removal methods in contributing to attaining the long-term goal of the Paris Agreement and investigates best practices in the implementation of the collaborative instruments under Article 6 for their incentivisation and scaling. The present climate policy and actual decision-making are still centred on achieving net-zero carbon emissions but the long-term challenge is the inevitable reversal of the overshoot, requiring carbon removal to outpace residual emissions, leading to net negative emissions globally. The report discusses the need to assign responsibility for climate overshoot reversal in order to guarantee the viability of a global net-negative GHG economy. The report analyses and proposes ways to address risks associated with carbon removal, including mitigation deterrence, that carbon removed from the atmosphere might be re-released, carbon-leakage effects, and challenges related to monitoring mitigation outcomes. It offers recommendations based on these deliberations.
|
|
| 5. |
- Bjarnadóttir, Thóra K., et al.
(författare)
-
The human and mouse repertoire of the adhesion family of G-protein-coupled receptors
- 2004
-
Ingår i: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 84:1, s. 23-33
-
Tidskriftsartikel (refereegranskat)abstract
- The adhesion G-protein-coupled receptors (GPCRs) (also termed LN-7TM or EGF-7TM receptors) are membrane-bound proteins with long N-termini containing multiple domains. Here, 2 new human adhesion-GPCRs, termed GPR133 and GPR144, have been found by searches done in the human genome databases. Both GPR133 and GPR144 have a GPS domain in their N-termini, while GPR144 also has a pentraxin domain. The phylogenetic analyses of the 2 new human receptors show that they group together without close relationship to the other adhesion-GPCRs. In addition to the human genes, mouse orthologues to those 2 and 15 other mouse orthologues to human were identified (GPR110, GPR111, GPR112, GPR113, GPR114, GPR115, GPR116, GPR123, GPR124, GPR125, GPR126, GPR128, LEC1, LEC2, and LEC3). Currently the total number of human adhesion-GPCRs is 33. The mouse and human sequences show a clear one-to-one relationship, with the exception of EMR2 and EMR3, which do not seem to have orthologues in mouse. EST expression charts for the entire repertoire of adhesion-GPCRs in human and mouse were established. Over 1600 ESTs were found for these receptors, showing widespread distribution in both central and peripheral tissues. The expression patterns are highly variable between different receptors, indicating that they participate in a number of physiological processes.
|
|
| 6. |
- Ekblom, Robert, et al.
(författare)
-
Balancing selection, sexual selection and geographic structure in MHC genes of Great Snipe
- 2010
-
Ingår i: Genetica. - : Springer Science and Business Media LLC. - 0016-6707 .- 1573-6857. ; 138:4, s. 453-461
-
Tidskriftsartikel (refereegranskat)abstract
- Signatures of balancing selection are often found when investigating the extremely polymorphic regions of major histocompatibility complex (MHC) genes, and it is generally accepted that selective forces maintain this polymorphism. However, the exact nature of the selection is controversial. Theoretical studies have mainly focused on overdominance and/or frequency dependent selection while laboratory studies have emphasised the role of mate choice. Empirical field data, on the other hand, have been relatively scarce. Previously we have found that geographic structure in MHC class II genes of the Great Snipe (Gallinago media) is too pronounced to be explained by neutral forces alone. Here we test the hypothesis that sexual selection on MHC alleles may be influencing this geographic structure between mountain and lowland populations. We found evidence of balancing selection acting on MHC genes in the form of a higher rate of amino-acid changing substitutions compared to silent substitutions in the peptide binding regions. Not only natural selection but also sexual selection may influence MHC polymorphism in this bird because certain MHC alleles have been found to be associated with higher male mating success. Contrary to predictions from negative frequency dependent selection, males carrying locally rare alleles did not have a mating advantage. Instead, the mating success of alleles in a mountain population was positively correlated to their relative frequency in the mountains compared to the lowlands, implying that locally adapted MHC alleles may also be favoured by sexual selection.
|
|
| 7. |
- Ekblom, Robert, et al.
(författare)
-
Female choice and male humoral immune response in the lekking great snipe (Gallinago media)
- 2005
-
Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 16:2, s. 346-351
-
Tidskriftsartikel (refereegranskat)abstract
- Parasites and diseases constitute major evolutionary forces in many natural populations, and thus having an efficient immune defense to resist infections is crucial for many organisms. Properties of the immune response may also influence mate choice decisions in many animals. Theory predicts several advantages for females when choosing males with superior immune systems. These benefits can be both direct (e.g. increased paternal care and reduced disease transmission) and indirect (good genes). We have investigated female choice with respect to antibody response to two novel antigens in males of a lekking bird, the great snipe (Gallinago media). Because of the lek mating system, female choice probably mainly incurs indirect (genetic) rather than direct benefits. Males responded to vaccination with diphtheria and tetanus toxoids by producing specific antibodies to both antigens. Triggering the immune system had no negative impact on display activities or survival. Males that were chosen by females as mates had on average higher antibody response to the tetanus antigen than their neighbors. We did not, however, find any covariance between the strength of the antibody response and male mating success.
|
|
| 8. |
|
|
| 9. |
- Ekblom, Robert, 1976-
(författare)
-
Immunoecology of the Great Snipe (Gallinago media) : Mate Choice, MHC Variation, and Humoral Immunocompetence in a Lekking Bird
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- At the centre of the vertebrate immune system is a group of proteins called MHC (major histocompatibility complex) molecules. These function in self – non self recognition and activation of the immune defence against intruding parasites and pathogens. In this thesis I have investigated individual variation in MHC class II genes and antibody producing ability in relation to ecology and behaviour in the great snipe (Gallinago media), a lekking bird, breeding in northern Europe. There was much variation in the MHC genes of the great snipe and the sequence data show that balancing selection has been acting on these genes. I found genetic differentiation in the MHC between two separate geographic regions of the great snipe distribution. Furthermore, this structure was more pronounced than that previously found in neutral genetic markers, suggesting that different selection pressures (possibly resulting from variation in parasitic fauna) are acting in these different regions. The birds produced specific antibodies following injection with two novel antigens. Males that were chosen as mates, had higher antibody titers than their neighbouring males, suggesting that this ability may be important in female mate choice. Such choice could give the offspring an enhanced immune system or could favour females directly by avoidance of sexually transmitted diseases. Females choosing to mate with a male having a different set of MHC genes than their own could give the offspring immune system the ability to react to a wide range of parasites. No such mate choice could, however, be found in the great snipe. Instead, females preferred males with certain MHC alleles, irrespective of their own MHC type. If those alleles confer resistance to parasites currently prevailing in the population, such resistance would be inherited by the offspring, thereby enhancing their fitness.
|
|
| 10. |
- Ekblom, Robert, et al.
(författare)
-
Major histocompatibility complex variation and mate choice in a lekking bird, the great snipe (Gallinago media)
- 2004
-
Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 13:12, s. 3821-3828
-
Tidskriftsartikel (refereegranskat)abstract
- Genes of the major histocompatibility complex (MHC) play a major part in the activation of the vertebrate immune system. In addition, they also appear to function as cues for mate choice. In mammals especially, several kinds of MHC-dependent mate choice have been hypothesized and observed. These include choice of mates that share no or few alleles with the choosing individual, choice of mates with alleles that differ as much as possible from the choosing individual, choice of heterozygous mates, choice of certain genotypes and choice of rare alleles. We investigated these different aspects of mate choice in relation to MHC in a lekking bird species, the great snipe (Gallinago media). We found no evidence for MHC disassortative mating, no preference for males with many MHC alleles and no preference for rare alleles. However, we did find that some allelic lineages were more often found in males with mating success than in males without mating success. Females do not seem to use themselves as references for the MHC-dependent mate choice, rather they seem to prefer males with certain allele types. We speculate that these alleles may be linked to resistance to common parasites.
|
|
