scholarly journals Omega-3 Pathways in Upwelling Systems: The Link to Nitrogen Supply

2021 ◽  
Vol 8 ◽  
Author(s):  
Eleonora Puccinelli ◽  
Fany Sardenne ◽  
Laure Pecquerie ◽  
Sarah E. Fawcett ◽  
Eric Machu ◽  
...  

Omega-3 long-chain polyunsaturated fatty acids (hereafter, omega-3), including eicosapentaenoic-acid (EPA) and docosahexaenoic-acid (DHA), are essential nutritional compounds for humans, providing several benefits related to cardiovascular and neural health. Human intake of omega-3 occurs mostly via seafood, particularly fish. The primary source of omega-3 in aquatic systems is represented by primary producers, from which omega-3 are transferred throughout the food web. Nitrogen is an essential nutrient for primary producers and can be supplied to surface waters as nitrate upwelled from below, or as ammonium and other regenerated nitrogen forms recycled in situ. Eastern Boundary Upwelling Systems (EBUS) are the most productive marine systems on Earth, together covering only 2% of the ocean’s surface area but supporting 25% of the global fish catch, thereby providing food for humans. In EBUS, nitrate and other nutrients are advected to the surface to support the proliferation of a phytoplankton community dominated by known omega-3 producers (i.e., diatoms). Given current climate change-related projections of ocean warming, acidification, deoxygenation, and increased upwelling intensity, phytoplankton community composition in EBUS may change. Additionally, the global production of EPA + DHA is expected to decrease by up to 30%, rendering its supply for human consumption insufficient by 2050. Here we discuss the state of knowledge related to omega-3 transfer from phytoplankton to small pelagic fish in EBUS, including factors that can influence omega-3 production, links to nitrogen cycling, climate change implications for the omega-3 supply to humans, and suggestions for future research directions to improve our understanding of omega-3 in the ocean.

2021 ◽  
pp. 004728162110078
Author(s):  
Shanna Cameron ◽  
Alexandra Russell ◽  
Luke Brake ◽  
Katherine Fredlund ◽  
Angela Morris

This article engages with recent discussions in the field of technical communication that call for climate change research that moves beyond the believer/denier dichotomy. For this study, our research team coded 900 tweets about climate change and global warming for different emotions in order to understand how Twitter users rely on affect rhetorically. Our findings use quantitative content analysis to challenge current assumptions about writing and affect on social media, and our results indicate a number of arenas for future research on affect, global warming, and rhetoric.


Games ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 45
Author(s):  
Tiziana Ciano ◽  
Massimiliano Ferrara ◽  
Mariangela Gangemi ◽  
Domenica Stefania Merenda ◽  
Bruno Antonio Pansera

This work aims to provide different perspectives on the relationships between cooperative game theory and the research field concerning climate change dynamics. New results are obtained in the framework of competitive bargaining solutions and related issues, moving from a cooperative approach to a competitive one. Furthermore, the dynamics of balanced and super-balanced games are exposed, with particular reference to coalitions. Some open problems are presented to aid future research in this area.


2021 ◽  
pp. 152483802098554
Author(s):  
Stephanie Gusler ◽  
Jessy Guler ◽  
Rachel Petrie ◽  
Heather Marshall ◽  
Daryl Cooley ◽  
...  

Although evidence suggests that individuals’ appraisals (i.e., subjective interpretations) of adverse or traumatic life events may serve as a mechanism accounting for differences in adversity exposure and psychological adjustment, understanding this mechanism is contingent on our ability to reliably and consistently measure appraisals. However, measures have varied widely between studies, making conclusions about how best to measure appraisal a challenge for the field. To address this issue, the present study reviewed 88 articles from three research databases, assessing adults’ appraisals of adversity. To be included in the scoping review, articles had to meet the following criteria: (1) published no earlier than 1999, (2) available in English, (3) published as a primary source manuscript, and (4) included a measure assessing for adults’ (over the age of 18) subjective primary and/or secondary interpretations of adversity. Each article was thoroughly reviewed and coded based on the following information: study demographics, appraisal measurement tool(s), category of appraisal, appraisal dimensions (e.g., self-blame, impact, and threat), and the tool’s reliability and validity. Further, information was coded according to the type of adversity appraised, the time in which the appraised event occurred, and which outcomes were assessed in relation to appraisal. Results highlight the importance of continued examination of adversity appraisals and reveal which appraisal tools, categories, and dimensions are most commonly assessed for. These results provide guidance to researchers in how to examine adversity appraisals and what gaps among the measurement of adversity appraisal which need to be addressed in the future research.


2010 ◽  
Vol 7 (12) ◽  
pp. 3941-3959 ◽  
Author(s):  
I. Marinov ◽  
S. C. Doney ◽  
I. D. Lima

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.


2019 ◽  
Vol 11 (4) ◽  
pp. 1163 ◽  
Author(s):  
Melissa Bedinger ◽  
Lindsay Beevers ◽  
Lila Collet ◽  
Annie Visser

Climate change is a product of the Anthropocene, and the human–nature system in which we live. Effective climate change adaptation requires that we acknowledge this complexity. Theoretical literature on sustainability transitions has highlighted this and called for deeper acknowledgment of systems complexity in our research practices. Are we heeding these calls for ‘systems’ research? We used hydrohazards (floods and droughts) as an example research area to explore this question. We first distilled existing challenges for complex human–nature systems into six central concepts: Uncertainty, multiple spatial scales, multiple time scales, multimethod approaches, human–nature dimensions, and interactions. We then performed a systematic assessment of 737 articles to examine patterns in what methods are used and how these cover the complexity concepts. In general, results showed that many papers do not reference any of the complexity concepts, and no existing approach addresses all six. We used the detailed results to guide advancement from theoretical calls for action to specific next steps. Future research priorities include the development of methods for consideration of multiple hazards; for the study of interactions, particularly in linking the short- to medium-term time scales; to reduce data-intensivity; and to better integrate bottom–up and top–down approaches in a way that connects local context with higher-level decision-making. Overall this paper serves to build a shared conceptualisation of human–nature system complexity, map current practice, and navigate a complexity-smart trajectory for future research.


2020 ◽  
Vol 11 ◽  
Author(s):  
Courtney B. Johnson ◽  
Jizhou Zhang ◽  
Daniel Lucas

Hematopoiesis in the bone marrow (BM) is the primary source of immune cells. Hematopoiesis is regulated by a diverse cellular microenvironment that supports stepwise differentiation of multipotent stem cells and progenitors into mature blood cells. Blood cell production is not static and the bone marrow has evolved to sense and respond to infection by rapidly generating immune cells that are quickly released into the circulation to replenish those that are consumed in the periphery. Unfortunately, infection also has deleterious effects injuring hematopoietic stem cells (HSC), inefficient hematopoiesis, and remodeling and destruction of the microenvironment. Despite its central role in immunity, the role of the microenvironment in the response to infection has not been systematically investigated. Here we summarize the key experimental evidence demonstrating a critical role of the bone marrow microenvironment in orchestrating the bone marrow response to infection and discuss areas of future research.


Author(s):  
Wilfrid Greaves

This article examines the implications of human-caused climate change for security in Canada. The first section outlines the current state of climate change, the second discusses climate change impacts on human security in Canada, and the third outlines four other areas of Canada’s national interests threatened by climate change: economic threats; Arctic threats; humanitarian crises at home and abroad; and the threat of domestic conflict. In the conclusion, I argue that climate change has clearly not been successfully “securitized” in Canada, despite the material threats it poses to human and national security, and outline directions for future research.


Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 449 ◽  
Author(s):  
Magnús Örn Stefánsson ◽  
Sigurður Baldursson ◽  
Kristinn P. Magnússon ◽  
Arnheiður Eyþórsdóttir ◽  
Hjörleifur Einarsson

The following study reports on the first thraustochytrid isolates identified from Iceland. They were collected from three different locations off the northern coast of the country (Location A, Skagaströnd; Location B, Hveravík; and Location C, Eyjafjörður). Using 18S rDNA sequence analysis, isolates from Locations A and B were identified within the Thraustochytrium kinnei species while other isolates within the Sicyoidochytrium minutum species when compared to other known strains. Cells isolated from Locations A ( 2 . 10 ± 0 . 70 g/L) and B ( 1 . 54 ± 0 . 17 g/L) produced more biomass than the ones isolated from Location C ( 0 . 43 ± 0 . 02 g/L). This study offers the first-time examination of the utility of byproducts from fisheries as a nitrogen source in media formulation for thraustochytrids. Experiments showed that isolates produced more biomass (per unit of substrate) when cultured on nitrogen of marine ( 2 . 55 ± 0 . 74 g/L) as compared to of commercial origin (  1 . 06 ± 0 . 57 g/L). Glycerol ( 2 . 43 ± 0 . 56 g/L) was a better carbon source than glucose ( 1 . 84 ± 0 . 57 g/L) in growth studies. Fatty acid (FA) profiles showed that the isolates from Location C (S. minutum) had low ratios of monounsaturated ( 4 . 21 ± 2 . 96 % ) and omega-6 ( 0 . 68 ± 0 . 59 % ) FAs. However, the isolates also had high ratios of docosahexaenoic acid (DHA; 35 . 65 ± 1 . 73 % ) and total omega-3 FAs ( 40 . 39 ± 2 . 39 % ), indicating that they could serve as a source of marine oils for human consumption and in aquaculture feeds. The T. kinnei isolates from Location A could be used in biodiesel production due to their high ratios of monounsaturated ( 18 . 38 ± 6 . 27 % ) long chain ( 57 . 43 ± 8 . 27 % ) FAs.


2018 ◽  
Vol 23 (3) ◽  
pp. 217-233 ◽  
Author(s):  
Stephane Hallegatte ◽  
Marianne Fay ◽  
Edward B. Barbier

AbstractBecause their assets and income represent such a small share of national wealth, the impacts of climate change on poor people, even if dramatic, will be largely invisible in aggregate economic statistics such as the Gross Domestic Product (GDP). Assessing and managing future impacts of climate change on poverty requires different metrics, and specific studies focusing on the vulnerability of poor people. This special issue provides a set of such studies, looking at the exposure and vulnerability of people living in poverty to shocks and stressors that are expected to increase in frequency or intensity due to climate change, such as floods, droughts, heat waves, and impacts on agricultural production and ecosystem services. This introduction summarizes their approach and findings, which support the idea that the link between poverty and climate vulnerability goes both ways: poverty is one major driver of people's vulnerability to climate-related shocks and stressors, and this vulnerability is keeping people in poverty. The paper concludes by identifying priorities for future research.


Agronomy ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 25 ◽  
Author(s):  
Tapan Pathak ◽  
Mahesh Maskey ◽  
Jeffery Dahlberg ◽  
Faith Kearns ◽  
Khaled Bali ◽  
...  

California is a global leader in the agricultural sector and produces more than 400 types of commodities. The state produces over a third of the country’s vegetables and two-thirds of its fruits and nuts. Despite being highly productive, current and future climate change poses many challenges to the agricultural sector. This paper provides a summary of the current state of knowledge on historical and future trends in climate and their impacts on California agriculture. We present a synthesis of climate change impacts on California agriculture in the context of: (1) historic trends and projected changes in temperature, precipitation, snowpack, heat waves, drought, and flood events; and (2) consequent impacts on crop yields, chill hours, pests and diseases, and agricultural vulnerability to climate risks. Finally, we highlight important findings and directions for future research and implementation. The detailed review presented in this paper provides sufficient evidence that the climate in California has changed significantly and is expected to continue changing in the future, and justifies the urgency and importance of enhancing the adaptive capacity of agriculture and reducing vulnerability to climate change. Since agriculture in California is very diverse and each crop responds to climate differently, climate adaptation research should be locally focused along with effective stakeholder engagement and systematic outreach efforts for effective adoption and implementation. The expected readership of this paper includes local stakeholders, researchers, state and national agencies, and international communities interested in learning about climate change and California’s agriculture.


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