| 1. |
- Berndt, Sonja I., et al.
(author)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Journal article (peer-reviewed)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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| 2. |
- Bonaglia, Stefano, et al.
(author)
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The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study
- 2017
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In: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 14:2, s. 285-300
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Journal article (peer-reviewed)abstract
- Over the last decades, the impact of human activities on the global nitrogen (N) cycle has drastically increased. Consequently, benthic N cycling has mainly been studied in anthropogenically impacted estuaries and coasts, while in oligotrophic systems its understanding is still scarce. Here we report on benthic solute fluxes and on rates of denitrification, anammox, and dissimilatory nitrate reduction to ammonium (DNRA) studied by in situ incubations with benthic chamber landers during two cruises to the Gulf of Bothnia (GOB), a cold, oligotrophic basin located in the northern part of the Baltic Sea. Rates of N burial were also inferred to investigate the fate of fixed N in these sediments. Most of the total dissolved fixed nitrogen (TDN) diffusing to the water column was composed of organic N. Average rates of dinitrogen (N-2) production by denitrification and anammox (range: 53-360 mu mol Nm(-2) day(-1)) were comparable to those from Arctic and subarctic sediments worldwide (range: 34-344 mu mol Nm(-2) day(-1)). Anammox accounted for 18-26% of the total N2 production. Absence of free hydrogen sulfide and low concentrations of dissolved iron in sediment pore water suggested that denitrification and DNRA were driven by organic matter oxidation rather than chemolithotrophy. DNRA was as important as denitrification at a shallow, coastal station situated in the northern Bothnian Bay. At this pristine and fully oxygenated site, ammonium regeneration through DNRA contributed more than one-third to the TDN efflux and accounted, on average, for 45% of total nitrate reduction. At the offshore stations, the proportion of DNRA in relation to denitrification was lower (0-16% of total nitrate reduction). Median value and range of benthic DNRA rates from the GOB were comparable to those from the southern and central eutrophic Baltic Sea and other temperate estuaries and coasts in Europe. Therefore, our results contrast with the view that DNRA is negligible in cold and well-oxygenated sediments with low organic carbon loading. However, the mechanisms behind the variability in DNRA rates between our sites were not resolved. The GOB sediments were a major source (237 kt yr(-1), which corresponds to 184% of the external N load) of fixed N to the water column through recycling mechanisms. To our knowledge, our study is the first to document the simultaneous contribution of denitrification, DNRA, anammox, and TDN recycling combined with in situ measurements.
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| 3. |
- Hall, Marcus, et al.
(author)
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Reproductive homing and fine-scaled genetic structuring of anadromous Baltic Sea perch (Perca fluviatilis)
- 2022
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In: Fisheries Management and Ecology. - : John Wiley & Sons. - 0969-997X .- 1365-2400. ; 29:5, s. 586-596
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Journal article (peer-reviewed)abstract
- To investigate the population dynamics of anadromous Baltic Sea perch Perca fluviatilis (Linnaeus), we studied the migratory behaviour (arrival to spawning location) and population structure (genetic structure and differentiation) of three closely located (<50 km) populations. Spawning migration lasted for 32-80 days, and passive integrated transponder tag (PIT-tag) data indicated that anadromous perch displayed reproductive homing. Populations were differentiated, despite low levels of gene flow (3%-5%), and differentiation increased with increasing geographic distance. This fine-scaled spatial structuring was likely, at least partly, explained by homing behaviour. Analyses of temporal within-stream substructuring yielded inconclusive results, so further studies are required to evaluate this. Taken together, our findings highlight the potential for fine-scaled genetic structuring in anadromous perch and indicate that multiple mechanisms, such as isolation by distance, homing, and reproductive timing could contribute to this pattern. This illustrates the importance of considering cryptic barriers to accurately identify reproductive units, and points to the need for local management of anadromous perch.
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| 4. |
- Nilsson, Madeleine, et al.
(author)
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Particle shuttling and oxidation capacity of sedimentary organic carbon on the Baltic Sea system scale
- 2021
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In: Marine Chemistry. - : Elsevier BV. - 0304-4203. ; 232
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Journal article (peer-reviewed)abstract
- Continental margin sediments receive most of the particulate organic carbon (POC) deposited on the global seafloor, making them crucial locations in the carbon cycle. However, the complex environments in coastal oceans make it challenging to predict the fate of sedimentary organic carbon (OC) in these areas. Here we use data from 21 sites in the Baltic Sea, representing different biological and physiochemical regimes, to explore controls on sedimentary OC cycling. To this end, we combine in situ measured benthic fluxes of dissolved inorganic carbon (DIC; proxy for OC oxidation) with data on sediment properties. In the Gulf of Bothnia, low sedimentary OC oxidation capacities (yearly DIC flux divided by sedimentary POC inventory) were likely caused by a large fraction of terrestrial material in the POC pool, indicated by low sedimentary chlorophyll a content and high (> 10) carbon:nitrogen ratios. The highest OC oxidation capacities were measured at shallow, permanently oxic sites in the Baltic Proper, where bioturbation likely stimulates OC oxidation. The other sites in the Baltic Proper and all stations in the Gulf of Finland displayed increasing OC oxidation capacities with increasing normalised water depth (station depth divided by maximal depth in the basin). This pattern suggests that substantial quantities of POC are shuttled, through repeated cycles of resuspension-redeposition, from shallow erosion-transport (ET) areas to deep accumulation (A) areas. This interpretation was supported by decreasing sediment age and increasing sedimentary inventories of POC and chlorophyll a with normalised water depth. Our calculations indicate that particle shuttling redistributes almost half of the deposited export production from ET areas to A areas in the Baltic Proper, and that substantial amounts of terrestrial organic material are transported through particle shuttling to the deeper parts of the Gulf of Finland and Gulf of Bothnia. Depositional setting and POC origin can thus be central factors in predicting the distribution and fate of OC in coastal and shelf sediments.
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| 5. |
- Speliotes, Elizabeth K., et al.
(author)
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Association analyses of 249,796 individuals reveal 18 new loci associated with body mass index
- 2010
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 937-948
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Journal article (peer-reviewed)abstract
- Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ~2.8 million SNPs in up to 123,865 individuals with targeted follow up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity susceptibility loci and identified 18 new loci associated with body mass index (P < 5 × 10−8), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation.
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| 6. |
- Ståhl, H., et al.
(author)
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Factors influencing organic carbon recycling and burial in Skagerrak sediments
- 2004
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In: Journal of Marine Research. - : Journal of Marine Research/Yale. - 0022-2402 .- 1543-9542. ; 62:6, s. 867-907
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Journal article (peer-reviewed)abstract
- Different factors influencing recycling and burial rates of organic carbon (OC) were investigated in the continental margin sediments of the Skagerrak (NE North Sea). Two different areas, one in the southern and one in the northeastern part of the Skagerrak were visited shortly after a spring bloom (March 1999) and in late summer (August 2000). Results suggested that: (1) Organic carbon oxidation rates (C-ox) (2.2-18 mmol Cm-2 d(-1)) were generally larger than the O-2 uptake rates (1.9-25 mmol m(-2) d(-1)). Both rates were measured in situ using a benthic lander. A mean apparent respiration ratio (C-ox:O-2corr) of 1.3 +/- 0.5 was found, indicating some long-term burial of reduced inorganic substances in these sediments. Measured O-2, fluxes increased linearly with increasing C-ox rates during the late summer cruise but not on the, early spring cruise, indicating a temporal uncoupling of anaerobic mineralization and reoxidation of reduced substances. (2) Dissolved organic carbon (DOC) fluxes (0.2-1.0 mmol Cm-2 d(-1)) constituted 3-10% of the C-ox rates and were positively correlated with the latter, implying that net DOC production rates were proportional to the overall sediment OC remineralization rates. (3) Chlorophyll a (Chl-a) concentrations in the sediment were significantly higher in early spring compared to late summer. The measured C-ox rates, but not O-2 fluxes, showed a strong positive correlation with the Chl-a inventories in the top 3 cm of the sediment. (4) Although no relationship was found between the benthic fluxes and the macrofaunal biomass in the chambers, total in situ measured dissolved inorganic carbon (C-T) fluxes were 1-5.4 times higher than diffusive mediated C-T fluxes, indicating that macrofauna have a significant impact on benthic exchange rates of OC remineralization products in Skagerrak sediments. (5) OC burial fluxes were generally higher in northeastern Skagerrak than in the southern part. The same pattern was observed for burial efficiencies, with annual means of similar to62% and similar to43% for the two areas respectively. (6) On a basin-wide scale, there was a significant positive linear correlation between the burial efficiencies and sediment accumulation rates. (7) The calculated particulate organic carbon (POC) deposition, from benthic flux and burial measurements, was only 24-78% of the sediment trap measured POC deposition, indicating a strong near-bottom lateral transport and resuspension of POC. (8) A larger fraction of the laterally advected material of lower quality seemed to settle in the northeastern Skagerrak rather than in the southern Skagerrak. (9) Skagerrak sediments, especially in the northeastern part, act as an efficient net sink for organic carbon, even in a global continental margin context.
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| 7. |
- Viktorsson, Lena, 1980, et al.
(author)
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Recycling and burial of phosphorus in sediments of an anoxic fjord - The By Fjord, western Sweden
- 2013
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In: Journal of Marine Research. - : Journal of Marine Research/Yale. - 0022-2402 .- 1543-9542. ; 71:5, s. 351-374
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Journal article (peer-reviewed)abstract
- Recycling and burial of sediment phosphorus were studied in the By Fjord, western Sweden, during the years 2009 to 2010 using autonomous benthic landers and sediment sampling. The By Fjord is a small fjord with a shallow sill at its narrow mouth, which limits water exchange of the fjord’s basin water. The water in the basin is exchanged only every 3 to 5 years and the water below sill level is anoxic or sulfidic between water renewals. Five sites were examined in the By Fjord; three shallow sites above the sill level with oxic bottom waters and two deeper sites with anoxic bottom waters. Contents of sediment organic carbon and total nitrogen were higher at deep stations when compared to shallow stations, whereas the contents of sediment inorganic P was higher, and sediment organic P generally lower, at shallow than at deep stations both in surficial and buried sediment. One shallow oxic site and one deep anoxic site were also examined in the adjacent Koljo Fjord having similar characteristics as the By Fjord. In situ measurements of benthic fluxes of dissolved inorganic phosphorus (DIP) showed that the fluxes from sediments with oxic overlying water (0.05–0.23 mmol m−2 d−1) were much lower than fluxes from sediments with anoxic overlying water (1.25–2.26 mmol m−2 d−1). The DIP flux increased with increasing flux of dissolved inorganic carbon (DIC) not only at anoxic but also at oxic bottoms, which is different from observations in brackish water environments. The average ratio between the DIC and DIP fluxes at oxic bottoms was almost 10 times higher than the Redfield C:P ratio indicating partial immobilization of P in oxic sediments. In contrast, the C:P ratio in fluxes was on average 1.5 times lower than Redfield at the anoxic bottoms. The benthic fluxes from anoxic bottoms were P rich not only in relation to C, but also to N. The low C:P flux ratio at anoxic sites coincided with a ≈ 2.5 times higher than Redfield C:P ratio of organic matter in the sediment solid phase clearly suggesting preferential regeneration of P at anoxic bottoms. Burial of inorganic P was higher than organic P burial at both anoxic and oxic sites; the former made up 59 to 60% of the total P burial at the deep anoxic stations, and 80% at the main shallow oxic station. The burial efficiency for organic P at anoxic bottoms was estimated to be only 1 to 3%, which indicates extremely efficient recycling of deposited organic P under anoxic conditions in this fjord environment.
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| 8. |
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| 9. |
- Al-Saffar, Anas, 1969-, et al.
(author)
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Parallel Changes in Harvey-Bradshaw Index, TNFα, and Intestinal Fatty Acid Binding Protein in Response to Infliximab in Crohn’s Disease
- 2017
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In: Gastroenterology Research and Practice. - Egypt : Hindawi Publishing Corporation. - 1687-6121 .- 1687-630X. ; , s. 1-8
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Journal article (peer-reviewed)abstract
- Intestinal fatty acid binding protein (I-FABP) indicates barrier integrity. Aims: determine if I-FABP is elevated in active Crohn's disease (CD) and if I-FABP parallels anti-TNF alpha antibody (infliximab) induced lowering of TNF alpha and Harvey-Bradshaw Index (HBI) as potential indicator of mucosal healing. I-FABP distribution along human gut was determined. Serum from 10 CD patients collected during first three consecutive infliximab treatments with matched pretreatment and follow-up samples one week after each treatment and corresponding HBI data were analyzed. I-FABP reference interval was established from 31 healthy subjects with normal gut permeability. I-FABP and TNF alpha were measured by ELISA; CRP was measured by nephelometry. Healthy tissue was used for I-FABP immunohistochemistry. Pretreatment CD patient TNF alpha was 1.6-fold higher than in-house reference interval, while I-FABP was 2.5-fold higher, which lowered at follow-ups. Combining all 30 infusion/follow-up pairs also revealed changes in I-FABP. HBI followed this pattern; CRP declined gradually. I-FABP was expressed in epithelium of stomach, jejunum, ileum, and colon, with the highest expression in jejunum and ileum. I-FABP is elevated in active CD with a magnitude comparable to TNF alpha. Parallel infliximab effects on TNF alpha, HBI, and I-FABP were found. I-FABP may be useful as an intestine selective prognostic marker in CD.
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| 10. |
- Almroth, Elin, 1977, et al.
(author)
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Effects of resuspension on benthic fluxes of oxygen, nutrients, dissolved inorganic carbon, iron and manganese in the Gulf of Finland, Baltic Sea
- 2009
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In: Continental Shelf Research. - : Elsevier BV. - 0278-4343. ; 29, s. 807-818
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Journal article (peer-reviewed)abstract
- The effect of resuspension on benthic fluxes of oxygen (O2), ammonium (NH4+), nitrate (NO3−), phosphate (PO43−), silicate (Si(OH)4), dissolved inorganic carbon (DIC), total dissolved iron (Fe) and total dissolved manganese (Mn) was studied at three different stations in the Gulf of Finland (GoF), Baltic Sea during three cruises in June–July 2003, September 2004 and May 2005. The stations were situated on different bottom types in the western, central and eastern part, respectively, of the open GoF. The fluxes were measured in-situ using the autonomous Göteborg benthic lander. To simulate resuspension events, the stirring speed was increased in two of the four chambers of the lander after approximately half of the incubation time. The other two chambers were used as control chambers. Clear effects of resuspension were observed on the oxygen fluxes where an increase of the consumption was observed in 88% of the cases and on average with 59% (stdev=53). The NH4+ fluxes were affected in 50% of the cases (4 out of 8 incubations) at stations with low bottom water oxygen concentrations, but in no cases where the bottom water was oxygenated (0 out of 9 incubations). The NH4+ fluxes decreased by 26±27% in 2005 and by 114±19% in 2003. There was no clear effect of resuspension on the fluxes of any of the other solutes in this study. Thus, resuspension events did not play a significant role in release/uptake of NO3−, PO43−, Si(OH)4, DIC, Fe and Mn in GoF sediments. However, increased oxygen consumption as a result of resuspension may lead to spreading of anoxic/suboxic bottom water conditions, and thus indirectly to increased benthic release of phosphate, ammonium and iron.
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