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Benavides M, Bonnet S, Le Moigne FAC, Armin G, Inomura K, Hallstrøm S, Riemann L, Berman-Frank I, Poletti E, Garel M, Grosso O, Leblanc K, Guigue C, Tedetti M, Dupouy C. Sinking Trichodesmium fixes nitrogen in the dark ocean. ISME J 2022; 16:2398-2405. [PMID: 35835942 PMCID: PMC9478103 DOI: 10.1038/s41396-022-01289-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/29/2022] [Accepted: 07/05/2022] [Indexed: 01/04/2023]
Abstract
The photosynthetic cyanobacterium Trichodesmium is widely distributed in the surface low latitude ocean where it contributes significantly to N2 fixation and primary productivity. Previous studies found nifH genes and intact Trichodesmium colonies in the sunlight-deprived meso- and bathypelagic layers of the ocean (200-4000 m depth). Yet, the ability of Trichodesmium to fix N2 in the dark ocean has not been explored. We performed 15N2 incubations in sediment traps at 170, 270 and 1000 m at two locations in the South Pacific. Sinking Trichodesmium colonies fixed N2 at similar rates than previously observed in the surface ocean (36-214 fmol N cell-1 d-1). This activity accounted for 40 ± 28% of the bulk N2 fixation rates measured in the traps, indicating that other diazotrophs were also active in the mesopelagic zone. Accordingly, cDNA nifH amplicon sequencing revealed that while Trichodesmium accounted for most of the expressed nifH genes in the traps, other diazotrophs such as Chlorobium and Deltaproteobacteria were also active. Laboratory experiments simulating mesopelagic conditions confirmed that increasing hydrostatic pressure and decreasing temperature reduced but did not completely inhibit N2 fixation in Trichodesmium. Finally, using a cell metabolism model we predict that Trichodesmium uses photosynthesis-derived stored carbon to sustain N2 fixation while sinking into the mesopelagic. We conclude that sinking Trichodesmium provides ammonium, dissolved organic matter and biomass to mesopelagic prokaryotes.
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Affiliation(s)
- Mar Benavides
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
- Turing Center for Living Systems, Aix-Marseille University, 13009, Marseille, France.
| | - Sophie Bonnet
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Frédéric A C Le Moigne
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
- LEMAR, Laboratoire des Sciences de l'Environnement Marin, UMR6539, CNRS, UBO, IFREMER, IRD, 29280, Plouzané, Technopôle Brest-Iroise, France
| | - Gabrielle Armin
- Graduate School of Oceanography, University of Rhode Island, South Kingstown, RI, USA
| | - Keisuke Inomura
- Graduate School of Oceanography, University of Rhode Island, South Kingstown, RI, USA
| | - Søren Hallstrøm
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Lasse Riemann
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Ilana Berman-Frank
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt, Carmel, Haifa, Israel
| | - Emilie Poletti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Marc Garel
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Olivier Grosso
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Karine Leblanc
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Catherine Guigue
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Marc Tedetti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Cécile Dupouy
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
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Poletti E, Galvani M, Dubini A, Poletti V, Piciucchi S. Correlations between radiological and histological findings in patients with pulmonary vein stenosis after radiofrequency ablation: A case series. Pulmonology 2022; 28:396-398. [PMID: 35896431 DOI: 10.1016/j.pulmoe.2022.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/02/2022] [Accepted: 03/30/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- E Poletti
- IRCCS Policlinico San Donato, Milan/University of Milano Statale, Milan, Italy.
| | - M Galvani
- Department of Cardiology, GB Morgagni Hospital, Forlì/University of Bologna, Italy
| | - A Dubini
- Department of Pathology, GB Morgagni Hospital, Forlì/University of Bologna, Italy
| | - V Poletti
- Department of Diseases of the Thorax, GB Morgagni Hospital, Forlì/University of Bologna, Italy; Department of Respiratory Disease & Allergy, Aarhus University Hospital, Aarhus, Denmark
| | - S Piciucchi
- Department of Radiology, GB Morgagni Hospital, Forlì/University of Bologna, Italy
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Juul T, Bazzocchi G, Coggrave M, Johannesen IL, Hansen RBM, Thiyagarajan C, Poletti E, Krogh K, Christensen P. Reliability of the international spinal cord injury bowel function basic and extended data sets. Spinal Cord 2011; 49:886-91. [PMID: 21445082 DOI: 10.1038/sc.2011.23] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN This study was designed as an international validation study. OBJECTIVE The objective of this study was to assess the inter-rater reliability of the International Spinal Cord Injury Bowel Function Basic and Extended Data Sets. SETTING Three European spinal cord injury centers. METHODS In total, 73 subjects with spinal cord injury and a history of bowel dysfunction, out of which 77% were men and median age of the subjects was 49 years (range 20-81), were studied. The inter-rater reliability was estimated by having two raters complete both data sets on the same subject. First and second tests were separated by 14 days. Cohen's kappa was computed as a measure of agreement between raters. RESULTS Inter-rater reliability assessed by kappa statistics was very good (≥0.81) in 5 items, good (0.61-0.80) in 11 items, moderate (0.41-0.60) in 20 items, fair (0.21-0.40) in 11 and poor (<0.20) in 5 items. CONCLUSION Most items within the International Spinal Cord Injury Bowel Function Data sets have acceptable inter-rater reliability and are useful tools for data collection in international clinical practice and research. However, minor adjustments are recommended.
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Affiliation(s)
- T Juul
- Surgical Research Unit, Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark.
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Virgili R, Degni M, Schivazappa C, Faeti V, Poletti E, Marchetto G, Pacchioli MT, Mordenti A. Effect of age at slaughter on carcass traits and meat quality of Italian heavy pigs1. J Anim Sci 2003; 81:2448-56. [PMID: 14552371 DOI: 10.2527/2003.81102448x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Barrows and gilts (n = 128) from four breed crosses were used to investigate the effect of age at slaughter on carcass traits, proteolytic enzyme activity, and meat and fat quality. Pigs were blocked by breed cross into four blocks, and within blocks, one pen (eight barrows and eight gilts) was assigned randomly to be slaughtered at either 8 or 10 mo of age. Pigs were fed a corn-barley-soybean meal finisher diet from 104 +/- 2.5 d of age (37.7 +/- 0.33 kg BW) to the appropriate slaughter age. Carcasses from older (10 mo) pigs had lower (P < 0.01) muscularity indexes and lean cut yields than those of younger (8 mo) pigs, but dressing percentage and longissimus muscle area increased (P < 0.01) with age. Older pigs produced a redder (P < 0.01) and darker (P < 0.05) semimembranosus, with lower (P < 0.01) ultimate pH and cathepsin B and B + L activities, as well as higher (P < 0.01) aminopeptidase hydrolyzing activity than younger pigs. Moreover, the longissimus muscle of pigs slaughtered at 10 mo of age had lower (P < 0.01) drip and cooking loss percentages than that from pigs slaughtered at 8 mo of age. Ham subcutaneous fat from 10-mo-old pigs had greater (P < 0.05) percentages of oleic acid and lower (P < 0.01) proportions of moisture, linoleic, and linolenic acids than subcutaneous fat from pigs slaughtered at 8 mo of age. Results from this study indicate that fresh hams from pigs slaughtered at 10 mo of age would be more suitable for the production of high-quality, Italian, dry-cured hams.
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Affiliation(s)
- R Virgili
- Stazione Sperimentale per l'Industria delle Conserve Alimentari, 43100 Parma, Italy.
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