77 research outputs found
First basin-wide experimental results on N2-fixation in the open Mediterranean Sea.
Mediterranean Sea presents several biogeochemical anomalies compared to the global ocean. Unbalanced N budget, high nitrate/phosphate ratios in subsurface waters and light isotopic signals in particulate and dissolved nitrogen have suggested a relevant occurrence of N2-fixation. This study presents, for the first time, N2-fixation rate measurements in the open Mediterranean Sea on a basin scale during early summer, compared to one site in the North Atlantic. Very low rates (0.052?0.031 nmols N l-1d-1) were observed in all sub-regions of the Mediterranean, unlike the higher values measured in the North Atlantic surface waters (0.300?0.115 nmols N l-1d-1). No evidence of phosphate limitation emerges from this study. Low N2-fixation rates associated to light isotopic composition of PON (from -2.10 to 4.11?) suggest that other light N sources, different from atmospheric N2, fuel the Mediterranean ecosystem
CONTEMPORARY CLINICAL DECISION SUPPORT SYSTEMS: A PRELIMINARY REVIEW AND RESEARCH AGENDA
Clinical decision support systems (CDSS) improve healthcare delivery by providing data-driven opinions to care providers throughout the entire care process. The Information Systems (IS) community has produced many works on the subject in the last decade, and it is necessary to comprehensively examine the current state of research to determine the most promising themes to explore in future research. In this short paper, we conducted a literature review of the past five years to synthesise research efforts. By reviewing a preliminary sample of papers, we found that three major areas may be of interest to the IS Community: \u27Positive\u27 and \u27negative\u27 CDSS discontinuance, patient-centric value creation of CDSSs and the role of policy-makers in mitigating harmful social effects of CDSS policies. This research-in-progress will hopefully lead to the creation of a research agenda for CDSSs
Nitrogen fixation in the Mediterranean Sea
The Mediterranean Sea is an oligotrophic basin characterized by low nutrient levels and unusually high NO3/PO4 molar ratios in the deeper layers, that reach the maximum (N/P = 28) in the Eastern Mediterranean. An external nitrogen source needs to be claimed in order to explain the nitrogen excess. Pantoja et al. (2002) found that the 15N/14N natural abundance in particulate and in dissolved inorganic nitrogen display low values, suggesting an important role of a "light" nitrogen source. Two hypotheses can be invoked: (i) nitrogen compounds from atmospheric deposition and/or(ii)atmospheric molecular nitrogen throughout nitrogen fixation . During TRANSMED oceanographic cruise carried out in the framework of Italian project VECTOR(June 2007), N2 fixation experiments have been carried out all over the Mediterranean Sea and outside the Gibraltar Strait. Surprisingly, very low rates (< 0.10 nmol N2*l-1*d-1) have been observed in different areas of the basin, while higher values have been observed in Atlantic Ocean according with literature data. These preliminary results suggest a major role for nitrogen atmospheric deposition in shaping the NO3/PO4 anomaly of the basin. Pantoja, S., D. J. Repeta, J. P. Sachs, and D. M. Sigman (2002). Stable isotope constraints on the nitrogen cycle of the Mediterranean Sea water column, Deep Sea Res., Part I, 4, 1609- 1621
Denizlerdeki Mikrobiyal Reaksiyonların Yeni YaklaĆımlar Kullanılarak AraĆtırılması: Genetik, Biyojeokimya ve Modelleme
TĂBÄ°TAK ĂAYDAG15.10.2018ODTĂ Deniz Bilimleri EnstitĂŒsĂŒ tarafından Mersin Körfezi?nde 1997 yılından bu yanasĂŒrdĂŒrĂŒlen Erdemli Zaman Serisi (ETS) programı dahilinde ölĂ§ĂŒlen degiskenlere ek olarak, buproje kapsamında toplam su kolonu derinligi 200 metre olan istasyonda altı farklı derinliktenbir yıl boyunca aylık periyotlarda deniz suyu örneklemesi yapılmıstır. Bu örneklerde yeni nesildizileme yönteminin kullanıldıgı amplikon dizilemesi (metagenomik) analizleri yapılarakbiyojeokimyasal döngĂŒlerde önemli roller oynayan bakteri tĂŒrleri tayin edilmis, topluluk yapılarıve bolluklarının zamansal degisimi belirlenmistir. Taksalar arasında Pelagibacteriacea?ya aitolan SAR11 kladının tĂŒm derinlikler ve aylarda baskınlıgı gözlenmistir. Bu kladın ĂŒyelerifonksiyonel olarak organik maddeyi oksitleyerek karbondioksit ĂŒreten heterotrofik bakterilerdirve dolayısıyla biyojeokimyasal döngĂŒlerin remineralizasyon ayagında rol almaktadırlar.SAR11 kladının bollugu yıl boyunca %22 ve %64 arasında degisim göstermistir. SAR11kladının ekotipleri olan Clade Ia ve Clade Ib ise derinlige baglı yayılım göstermektedirler.Clade Ia yĂŒzey sularında baskınlık gösterirken Clade Ib?nin derin sularda komĂŒniteye katkısıdaha fazla olmaktadır. Bunun yanı sıra komĂŒnite yapısını belirleyen en önemli çevreselfaktörler sıcaklık, nitrat, görĂŒnĂŒr oksijen kullanımı, sezon ve ısıklı tabaka derinligi olarakbelirlenmistir. Sezonlar arasındaki filogenetik çesitlilik, belirgin olarak farklı bulunmustur.Bunun yanı sıra bakterilerin aktif metabolizmalarını tayin etmek için sezonluk olarak mRNAörneklemesi yapılmıs ve örnekler metatranskriptom yöntemi ile analiz edilmistir. Bu yöntemaracılıgı ile bakteriler tarafından gerçeklestirilen biyokimyasal reaksiyonların aktif ve inaktifoldukları dönemler saptanmıstır. Nitrifikasyonun ilk basamagı olan amonyak oksitilenmesiKasım ayında oldukça yĂŒksek bulunmustur. Ancak nitrifikasyonun ikinci basamagı olan nitritinnitrata oksitlenme sĂŒrecine ait olan belirteç genlere herhangi bir örnekde rastlanmamıstır.Sisteme yeni azot girdisi saglayan azot fiksasyonuna mRNA ifadelerinde rastlanmamıstır.Metatranskriptom yöntemine elde edilen bulgulara ek olarak nitrifikasyon ve azot fiksasyonsĂŒreçleri izotop yöntemi ile de her ay dört farklı derinlikten yapılan örneklemeler ilearastırılmıstır. Nitrifikasyonun sadece afotik bölgede gerçeklesmedigi görĂŒlmĂŒstĂŒr. Azotfiksasyonu belirteç genlerine rastlanmadıgı halde izotop yöntemi ile yapılan çalısmada azotfiksasyonu tĂŒm yıl boyunca ve tĂŒm derinliklerde çok dĂŒsĂŒk de olsa tespit edilmistir. AzotdöngĂŒsĂŒne ek olarak, metatranskriptom çalısması ile kısıtlı inorganik fosfat varlıgında aktiveolan alkalin fosfataz?ın sezonluk degisimi de göstermistir. Buna göre, ortamda dĂŒsĂŒk fosfatkonsantrasyonları gözlemlendiginde bakterilerin diger fosfor kaynaklarına yöneldigigözlemlenmistir.Bunlara ek olarak denizdeki biyokimyasal döngĂŒleri sayısal olarak temsil eden ve tahminleridirekt olarak ölĂ§ĂŒmlerle karsılastırılabilecek bir modelleme sistemi bölgeye uyarlanmıstır. Bumodelleme sistemi bir parametre tahmin algoritması ve proje kapsamında yapılan ölĂ§ĂŒmverileri ile birlestirilerek modelde reaksiyon hızlarını kontrol eden parametrelerin tahminiyapılmıstır. Bu tahmin sonucunda ortaya çıkan nitrifikasyon hızları izotop yöntemi ile yapılannitrifikasyon hızları ile karsılastırılmıstır. Bu karsılastırma reaksiyon hızları tahmini içinmodelleme sistemi ve parametre tahmini kullanımının zor olan izotop yöntemine alternatif biryöntem olma potansiyelini göstermistir.Yapılan bir yıllık gözlemler, kullanılan izotop yöntemleri ve modelleme yaklasımı bölgedekibilimsel bilgiye önemli katkılar saglamıstır. Bakteri topluluk yapıları TĂŒrkiye kıyılarında ilk defakĂŒltĂŒr bagımsız yöntemlerle ortaya konmustur. Bunun yanı sıra izotop yöntemleri ve yapılanmetatranscriptom çalısması bölgede azot fiksasyonunun baskın bir sĂŒreç olmadıgını ortayakoymustur. Biyojeokimyasal bir modelleme sistemi basarıyla bölgeye uyarlanmıstır.In addition to the measured variables within the Erdemli Time Series (ETS) monitoring programcarried out in Mersin Bay since 1997 by the METU-Institute of Marine Sciences, sea watersampling was performed where the total water column depth is 200 meters and from sixdifferent depths monthly for one year. These samples were analyzed by next generationsequencing using amplicon sequencing (metagenomic) approach and the bacterial speciesthat play important roles in biogeochemical cycles and the temporal changes of communitystructures and abundances were determined. SAR11 clade belonging to Pelagibacteriaceawas the most dominant taxa in all depths and months. SAR11 is ubiquitous in the seas andreplicate under the most limiting nutrient conditions. The abundance of the SAR11 cladethroughout the year ranged between 22% and 64%. Clade Ia and Clade Ib, the ecotypes ofthe SAR11 clade, showed depth-dependent distribution. Clade Ia dominated the surfacewaters, while Clade Ib contributes the most to the community in deeper waters. The mostimportant environmental factors that determine the community composition were determinedto be; temperature, nitrate, apparent oxygen utilization, season and euphotic zone depth.Phylogenetic diversity between seasons was found to be significantly different.Furthermore, to determine the active metabolism of bacteria mRNA samples were collectedseasonally and analyzed by metatranscriptomics approach. By using this approach, active andinactive periods of biochemical reactions mediated by bacteria was discovered. Ammoniaoxidation, the first step of nitrification, was found to be high in November. However, markergenes that are belong to nitrite oxidation to nitrate which is the second step of nitrification, havenot been detected in any samples. Indicator genes of nitrogen fixation which provides newnitrogen to the system was not found in mRNA expressions. In addition to the findings obtainedfrom the metatranscriptomics study, nitrification and nitrogen fixation processes wereinvestigated using isotope measurements from four different depths each month. It wasobserved that the nitrification did not occur only in the aphotic zone. Nitrogen fixation was notdetected in the indicator genes, but in the study conducted with isotope method, even with lowlevels, nitrogen fixation was determined throughout the year and depths. Additionally, to thenitrogen cycle, the seasonal change of alkaline phosphatase activity which is active especiallyduring inorganic phosphate limitation was also identified by the metatranscriptomics study.Accordingly, when low phosphate concentrations were observed in the environment, it wasobserved that bacteria adapt to use other phosphorus sources.Furthermore, a modeling system that represents the marine biochemical cycles numericallyand whose estimates can be compared directly with the measurements was adapted to theregion. This modeling system was combined with a parameter estimation scheme and measurements obtained in the project, and the parameters controlling the reaction rates in themodel were estimated. Nitrification rates according to the estimations were cpmpared with theresults of nitrification rates obtained by isotopic measurements. This comparison showed thepotential of using modeling system and parameter estimation as an alternative approach to thehard isotope measurements for estimating reaction rates.One-year long observations, isotope methods used and modeling approach have madesignificant contributions to scientific knowledge in the region. Bacterial community structurehave been revealed by culture-independent method for the first time in the coasts of Turkey.In addition, isotope methods and metatranscriptom study showed that nitrogen fixation is nota dominant process in the region. And a biogeochemical modeling system has beensuccessfully adapted to the region
Ocean acidification research in the Mediterranean Sea : status, trends and next steps
Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nationâs International Atomic Energy Agencyâs (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, and illustrates that both the Algero-Provencal and Ionian sub-basins are currently the least studied Mediterranean areas, 2) the carbonate system is still poorly quantified in coastal zones, and long-term time-series are still sparse across the Mediterranean Sea, which is a challenge for studying its variability and assessing coastal OA trends, 3) the most studied groups of organisms are autotrophs (algae, phanerogams, phytoplankton), mollusks, and corals, while microbes, small mollusks (mainly pteropods), and sponges are among the least studied, 4) there is an overall paucity in socio-economic, paleontological, and modeling studies in the Mediterranean Sea, and 5) in spite of general resource availability and the agreement for improved and coordinated OA governance, there is a lack of consistent OA policies in the Mediterranean Sea. In addition to highlighting the current status, trends and gaps of OA research, this work also provides recommendations, based on both our literature assessment and a survey that targeted the Mediterranean OA scientific community. In light of the ongoing 2021-2030 United Nations Decade of Ocean Science for Sustainable Development, this work might provide a guideline to close gaps of knowledge in the Mediterranean OA research.peer-reviewe
A global database of dissolved organic matter (DOM) concentration measurements in coastal waters (CoastDOM v1)
Measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) con-centrations are used to characterize the dissolved organic matter (DOM) pool and are important components ofbiogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOMv1; available at https://doi.org/10.1594/PANGAEA.964012, L\uf8nborg et al., 2023) compiling previously pub-lished and unpublished measurements of DOC, DON, and DOP in coastal waters. These data are complementedby hydrographic data such as temperature and salinity and, to the extent possible, other biogeochemical variables(e.g. chlorophyll a, inorganic nutrients) and the inorganic carbon system (e.g. dissolved inorganic carbon andtotal alkalinity). Overall, CoastDOM v1 includes observations of concentrations from all continents. However,most data were collected in the Northern Hemisphere, with a clear gap in DOM measurements from the SouthernHemisphere. The data included were collected from 1978 to 2022 and consist of 62 338 data points for DOC,20 356 for DON, and 13 533 for DOP. The number of measurements decreases progressively in the sequenceDOC > DON > DOP, reflecting both differences in the maturity of the analytical methods and the greater focuson carbon cycling by the aquatic science community. The global database shows that the average DOC concen-tration in coastal waters (average \ub1 standard deviation (SD): 182 \ub1 314 ÎŒmol C Lâ1; median: 103 ÎŒmol C Lâ1) is13-fold higher than the average coastal DON concentration (13.6 \ub1 30.4 ÎŒmol N Lâ1; median: 8.0 ÎŒmol N Lâ1),which is itself 39-fold higher than the average coastal DOP concentration (0.34 \ub1 1.11 ÎŒmol P Lâ1; median:0.18 ÎŒmol P Lâ1). This dataset will be useful for identifying global spatial and temporal patterns in DOM and willhelp facilitate the reuse of DOC, DON, and DOP data in studies aimed at better characterizing local biogeochem-ical processes; closing nutrient budgets; estimating carbon, nitrogen, and phosphorous pools; and establishing abaseline for modelling future changes in coastal waters
Ocean carbon from space: Current status and priorities for the next decade
This is the final version. Available on open access from Elsevier via the DOI in this recordData availability:
Data for Fig. 1a were generated from a free Scopus (https://www.scopus.com/) search of the terms "Ocean carbon satellite" (using All fields) in March 2022. Data from Fig. 1b and 1c were generated from the workshop registration and are available within the figure (participation number, geographical representation and gender split).The ocean plays a central role in modulating the Earthâs carbon cycle. Monitoring how the ocean carbon cycle is changing is fundamental to managing climate change. Satellite remote sensing is currently our best tool for viewing the ocean surface globally and systematically, at high spatial and temporal resolutions, and the past few decades have seen an exponential growth in studies utilising satellite data for ocean carbon research. Satellite-based observations must be combined with in-situ observations and models, to obtain a comprehensive view of ocean carbon pools and fluxes. To help prioritise future research in this area, a workshop was organised that assembled leading experts working on the topic, from around the world, including remote-sensing scientists, field scientists and modellers, with the goal to articulate a collective view of the current status of ocean carbon research, identify gaps in knowledge, and formulate a scientific roadmap for the next decade, with an emphasis on evaluating where satellite remote sensing may contribute. A total of 449 scientists and stakeholders participated (with balanced gender representation), from North and South America, Europe, Asia, Africa, and Oceania. Sessions targeted both inorganic and organic pools of carbon in the ocean, in both dissolved and particulate form, as well as major fluxes of carbon between reservoirs (e.g., primary production) and at interfaces (e.g., air-sea and landâocean). Extreme events, blue carbon and carbon budgeting were also key topics discussed. Emerging priorities identified include: expanding the networks and quality of in-situ observations; improved satellite retrievals; improved uncertainty quantification; improved understanding of vertical distributions; integration with models; improved techniques to bridge spatial and temporal scales of the different data sources; and improved fundamental understanding of the ocean carbon cycle, and of the interactions among pools of carbon and light. We also report on priorities for the specific pools and fluxes studied, and highlight issues and concerns that arose during discussions, such as the need to consider the environmental impact of satellites or space activities; the role satellites can play in monitoring ocean carbon dioxide removal approaches; economic valuation of the satellite based information; to consider how satellites can contribute to monitoring cycles of other important climatically-relevant compounds and elements; to promote diversity and inclusivity in ocean carbon research; to bring together communities working on different aspects of planetary carbon; maximising use of international bodies; to follow an open science approach; to explore new and innovative ways to remotely monitor ocean carbon; and to harness quantum computing. Overall, this paper provides a comprehensive scientific roadmap for the next decade on how satellite remote sensing could help monitor the ocean carbon cycle, and its links to the other domains, such as terrestrial and atmosphere.European Space AgencySimons FoundationUK National Centre for Earth Observation (NCEO)UKRIAtlantic Meridional Transect ProgrammeSwiss National Science Foundatio
New hints on nutrients dynamics and their impact on carbon sequestration in the Mediterranean Sea
In the World Ocean nitrogen and phosphorus cycles are deeply linked to the carbon cycle. As nitrate and phosphate play an important role in controlling biological production, the intensity of atmospheric carbon sequestration is strongly influenced by nutrient bioavailability. This thesis aims to contribute to the understanding of the ability of the Mediterranean Sea in absorbing C and N from the atmosphere.
The Mediterranean Sea presents several biogeochemical anomalies compared to the global ocean. The high nitrate/phosphate ratios in subsurface waters and the low 15N/14N ratios in particulate and dissolved nitrogen have suggested a significant occurrence of nitrogen fixation (N2 fixation) or an important impact of nitrogen atmospheric deposition.
This study presents, for the first time, a basin-wide overview of direct measurements of N2 fixation, with values in the North Atlantic for comparison. Very low N2 fixation rates (0.0520.031 nmols N l-1d-1) were observed in all sub-regions of the Mediterranean, in contrast to the higher values measured in the North Atlantic (0.3000.115 nmols N l-1d-1). Higher phosphorus (inorganic or organic) concentrations were not associated with higher N2 fixation rates.
An isotopic evaluation of the nitrogen sources based on isotopic signature of deep nitrate, N atmospheric deposition and Atlantic inflow nitrate, provides a rough estimate of the amount of N atmospheric deposition. The range varies between 22 and 60% of the total nitrate entering the Mediterranean Sea.
Large amount of N deposition from the atmosphere can explain both P-limitation and anomalous N/P ratio in deep layers. The external inputs of N, determining the excess of N in the marine system could ultimately fuel new production and enhance Mediterraneanâs ability in carbon sequestration
Lingotto. Test track or roof garden?
At the end of 2020, a ârestylingâ of the iconic test track on the roof of the former FIAT Lingotto plant in Turin was announced. It is part of a larger project that intends to establish commercial activities in and around the multifunctional complex related to environmental sustainability and electric mobility. According to the team of architects led by Benedetto Camerana, the track will be transformed into an elevated park (or, more properly, a roof garden) inspired by
the High Line, the linear park built on an abandoned elevated section of the New York Subway.
Transforming the test runway of the Lingotto with a roof-garden turns the futuristic roof of FIAT into an ordinary rural street. Perhaps we need to courageously verify that there is still a lack of awareness of the values of the industrial heritage that is not overcome in architectural practice. Nobody, I hope, would permanently put creepers on Antonelliâs Mole or rural flower boxes on the balustrades of Palazzo Madama in Piazza Castello, but on the Lingotto it seems normal. AIPAI-TICCIH Italy is obviously and cordially ready for a debate
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