scholarly journals Dietary polyunsaturated fatty acid supply improves Daphnia performance during vertical migration

2019 ◽  
Author(s):  
Jana Isanta Navarro ◽  
Matthias Fromherz ◽  
Michelle Dietz ◽  
Bettina Zeis ◽  
Anke Schwarzenberger ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Vertical Migration ◽  
Temperature Fluctuations ◽  
Temperature Acclimation ◽  
Trophic Levels ◽  
List Type ◽  
Dietary Pufa ◽  
Pufa Supplementation ◽  
Cold Temperatures ◽  
Cascading Effects

AbstractDiel vertical migration (DVM) is a common predator avoidance strategy of zooplankton. Migration to deeper water layers during the day to escape visually hunting predators most likely requires physiological adaptations to periodically changing temperatures. Polyunsaturated fatty acids (PUFA) are essential nutrients that play crucial roles in membrane temperature acclimation. Exposure to cold temperatures typically results in an increase in the relative abundance of PUFA in cell membranes and PUFA requirements of Daphnia have been shown to increase with decreasing temperatures.To assess the significance of dietary PUFA for coping with temperature fluctuations experienced during DVM, we reared Daphnia magna at either constantly warm or fluctuating temperatures simulating DVM both with and without dietary PUFA supplementation.We show that the well-known positive effect of dietary eicosapentaenoic acid (EPA) supplementation on offspring production and population growth rates of Daphnia is more pronounced at alternating temperatures than at constantly warm temperatures. Exposure to alternating temperatures caused modification in body PUFA concentrations and, consequently, increased lipid peroxidation. However, detrimental effects of lipid peroxidation were not evident.Our data demonstrate that the capacity to cope with the distinct temperature fluctuations experienced during DVM increases with dietary EPA supplementation, suggesting that an adequate dietary PUFA supply is crucial especially for migrating Daphnia populations. A dietary deficiency in long-chain PUFA may thus severely constrain predator evasion, potentially resulting in increased mortality and cascading effects on lower trophic levels.

scholarly journals Omega-3 Supplementation and Heart Disease: A Population-Based Diet by Gene Analysis of Clinical Trial Outcomes

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2154
Author(s):  
Maria Luz Fernandez ◽  
Sarah A. Blomquist ◽  
Brian Hallmark ◽  
Floyd H. Chilton
Keyword(s):  
Clinical Trials ◽  
Heart Disease ◽  
Fatty Acid Desaturase ◽  
Interaction Model ◽  
Dietary Exposure ◽  
Population Based ◽  
Biologically Active ◽  
Omega 3 ◽  
Dietary Pufa ◽  
Pufa Supplementation

Omega-3 (n-3) polyunsaturated fatty acids (PUFA) and their metabolites have long been recognized to protect against inflammation-related diseases including heart disease. Recent reports present conflicting evidence on the effects of n-3 PUFAs on major cardiovascular events including death. While some studies document that n-3 PUFA supplementation reduces the risk for heart disease, others report no beneficial effects on heart disease composite primary outcomes. Much of this heterogeneity may be related to the genetic variation in different individuals/populations that alters their capacity to synthesize biologically active n-3 and omega 6 (n-6) PUFAs and metabolites from their 18 carbon dietary precursors, linoleic acid (LA, 18:2 n-6) and alpha-linolenic (ALA, 18:3, n-3). Here, we discuss the role of a FADS gene-by-dietary PUFA interaction model that takes into consideration dietary exposure, including the intake of LA and ALA, n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in determining the efficacy of n-3 PUFA supplementation. We also review recent clinical trials with n-3 PUFA supplementation and coronary heart disease in the context of what is known about fatty acid desaturase (FADS) gene-by-dietary PUFA interactions. Given the dramatic differences in the frequencies of FADS variants that impact the efficiency of n-3 and n-6 PUFA biosynthesis, and their downstream signaling products among global and admixture populations, we conclude that large clinical trials utilizing “one size fits all” n-3 PUFA supplementation approaches are unlikely to show effectiveness. However, evidence discussed in this review suggests that n-3 PUFA supplementation may represent an important opportunity where precision interventions can be focused on those populations that will benefit the most from n-3 PUFA supplementation.

scholarly journals Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea

2020 ◽  
Author(s):  
Jan Niklas Macher ◽  
Berry B. van der Hoorn ◽  
Katja T. C. A. Peijnenburg ◽  
Lodewijk van Walraven ◽  
Willem Renema
Keyword(s):  
North Sea ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
List Type ◽  
The North ◽  
Shelf Sea ◽  
The North Sea ◽  
Zooplankton Communities

AbstractZooplankton are key players in marine ecosystems, linking primary production to higher trophic levels. The high abundance and high taxonomic diversity renders zooplankton ideal for biodiversity monitoring. However, taxonomic identification of the zooplankton assemblage is challenging due to its high diversity, subtle morphological differences and the presence of many meroplanktonic species, especially in coastal seas. Molecular techniques such as metabarcoding can help with rapid processing and identification of taxa in complex samples, and are therefore promising tools for identifying zooplankton communities. In this study, we applied metabarcoding of the mitochondrial cytochrome c oxidase I gene to zooplankton samples collected along a latitudinal transect in the North Sea, a shelf sea of the Atlantic Ocean. Northern regions of the North Sea are influenced by inflow of oceanic Atlantic waters, whereas the southern parts are characterised by more coastal waters. Our metabarcoding results indicated strong differences in zooplankton community composition between northern and southern areas of the North Sea, particularly in the classes Copepoda, Actinopterygii (ray-finned fishes) and Polychaeta. We compared these results to the known distributions of species reported in previous studies, and by comparing the abundance of copepods to data obtained from the Continuous Plankton Recorder (CPR). We found that our metabarcoding results are mostly congruent with the reported distribution and abundance patterns of zooplankton species in the North Sea. Our results highlight the power of metabarcoding to rapidly assess complex zooplankton samples, and we suggest that the technique could be used in future monitoring campaigns and biodiversity assessments.HighlightsZooplankton communities are different in northern and southern areas of the North SeaMetabarcoding results are consistent with known species distributions and abundanceMetabarcoding allows for fast identification of meroplanktonic species

scholarly journals Polyunsaturated fatty acids in the treatment of attention deficit hyperactivity disorder

2014 ◽  
Vol 4 (6) ◽  
pp. 245 ◽  
Author(s):  
Klaus W. Lange ◽  
Joachim Hauser ◽  
Shigehiko Kanaya ◽  
Ivo Kaunzinger ◽  
Katharina M Lange ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Attention Deficit Hyperactivity Disorder ◽  
Polyunsaturated Fatty Acids ◽  
Attention Deficit ◽  
Adhd Symptoms ◽  
Omega 3 ◽  
Dietary Pufa ◽  
Blood Concentrations ◽  
Pufa Supplementation ◽  
Hyperactivity Disorder

Background: Attention deficit/hyperactivity disorder (ADHD) is one of the most common behavioral disorders in children. Insufficient dietary intake of long-chain polyunsaturated fatty acids (LC-PUFAs) has been suggested to have an impact on the development of symptoms of ADHD in children. Individuals with ADHD have been demonstrated to have significantly reduced blood concentrations of PUFAs and, in particular, reduced levels of omega-3 (n-3) PUFAs. These findings suggest that PUFA supplementation may reduce the attention and behavior problems associated with ADHD.Objective: To provide an overview of the efficacy of dietary LC-PUFA supplementation in the treatment of ADHD. Methods: Literature published up until December 2013 on the effects of n-3 PUFA supplementation on ADHD symptoms was obtained using a PubMed search and critically reviewed.Results: Dietary PUFA supplementation appears to have beneficial effects on ADHD symptoms although these effects are small. The clinical relevance of these observations remains to be determined.Conclusion: There is only limited support for the efficacy of PUFA supplementation for the core symptoms of ADHD. Given the small effect sizes regarding PUFA supplementation, it may not be a sufficient therapy for a majority of patients with ADHD.Keywords: diet, nutrition, polyunsaturated fatty acid, PUFA, attention deficit/hyperactivity disorder, ADHD

scholarly journals Cascading effects of a top predator on intraspecific competition at intermediate and basal trophic levels

2018 ◽  
Vol 32 (9) ◽  
pp. 2241-2252 ◽  
Author(s):  
Catherine M. Matassa ◽  
Patrick J. Ewanchuk ◽  
Geoffrey C. Trussell
Keyword(s):  
Intraspecific Competition ◽  
Trophic Levels ◽  
Top Predator ◽  
Cascading Effects

Diel Vertical migration of marine organisms and the biological carbon pump

2021 ◽  
Author(s):  
Jerome Pinti ◽  
Tim DeVries ◽  
Tommy Norin ◽  
Camila Serra-Pompei ◽  
Roland Proud ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Food Web ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Marine Organisms ◽  
Trophic Levels ◽  
Mesopelagic Fish ◽  
Pelagic Food Web ◽  
Carbon Pump ◽  
Biological Carbon Pump

<p>Diel Vertical Migration (DVM) is a key feature of pelagic and mesopelagic ecosystems, mainly driven by predator-prey interactions along a time-varying vertical gradient of light. Marine organisms including meso-zooplankton and fish typically hide from visual predators at depth during daytime and migrate up at dusk to feed in productive near-surface waters during nighttime. Specific migration patterns, however, vary tremendously, for instance in terms of residency depth during day and night. In addition to environmental parameters such as light intensity and oxygen concentration, the migration pattern of each organism is intrinsically linked to the patterns of its conspecifics, its prey, and its predators through feedbacks that are hard to understand—but important to consider.</p><p>DVM not only affects trophic interactions, but also the biogeochemistry of the world’s oceans.  Organisms preying at the surface and actively migrating vertically transport carbon to depth, contributing to the biological carbon pump, and directly connecting surface production with mesopelagic and demersal ecosystems.</p><p>Here, we present a method based on a game-theoretic trait-based mechanistic model that enables the optimal DVM patterns for all organisms in a food-web to be computed simultaneously. The results are used to investigate the contributions of the different food-web pathways to the active component of the biological carbon pump. We apply the method to a modern pelagic food-web (comprised of meso- and macro-zooplankton, forage fish, mesopelagic fish, large pelagic fish and gelatinous organisms), shedding light on the direct effects that different trophic levels can have on the DVM behaviours of each other. The model is run on a global scale to assess the carbon export mediated by different functional groups, through fecal pellet production, carcasses sinking and respiration.</p><p>Finally, the model output is coupled to an ocean inverse circulation model to assess the carbon sequestration potential of the different export pathways. Results indicate that the carbon sequestration mediated by fish is much more important than presently recognised in global assessments of the biological carbon pump. The work we present relates to contemporary ecosystems, but we also explain how it can be adapted to fit any pelagic food-web structure to assess the contribution of the active biological pump to the global carbon cycle in past ecosystems.</p>

Structural and biochemical analyses of cardiac ventricular enlargement in cold-acclimated striped bass

1997 ◽  
Vol 273 (1) ◽  
pp. R252-R258 ◽  
Author(s):  
K. J. Rodnick ◽  
B. D. Sidell
Keyword(s):  
Striped Bass ◽  
Cardiac Tissue ◽  
Citrate Synthase ◽  
Temperature Acclimation ◽  
Circulatory Support ◽  
Ventricular Enlargement ◽  
Cold Temperatures ◽  
Atp Production ◽  
Ventricular Mass ◽  
Biochemical Analyses

We examined effects of temperature acclimation on ultrastructural characteristics of cardiac myocytes and maximal activities of metabolic enzymes in cardiac tissue of striped bass (Morone saxatilis). Ventricular mass and ventricular mass divided by body weight were significantly increased (29% and 40%, respectively) in animals acclimated to cold (5 degrees C) vs. warm temperatures (25 degrees C). Mean myocyte diameter was increased at cold temperature (3.47 +/- 0.14 vs. 2.98 +/- 0.08 microns), which is sufficient to explain the increase in ventricular mass. Ventricular enlargement did not alter volume densities of mitochondria, myofibrils, protein concentration, or citrate synthase activity. Thus total volume of mitochondria and myofibrils increased proportionately with cardiac mass in cold animals. Activities of hexokinase (34%) and carnitine palmitoyltransferase (42%) increased in cold animals, suggesting positive compensation and increased aerobic capacity for utilization of glucose and fatty acids for energy production. Enlargement of the ventricle and an increased capacity for ATP production in striped bass may help compensate for kinetic constraints at cold temperatures and maintain circulatory support to oxidative axial musculature for swimming activity.

Large mammals generate both top-down effects and extended trophic cascades on floral-visitor assemblages

2019 ◽  
Vol 35 (4) ◽  
pp. 185-198 ◽  
Author(s):  
Allison Louthan ◽  
Emily Valencia ◽  
Dino J. Martins ◽  
Travis Guy ◽  
Jacob Goheen ◽  
...  
Keyword(s):  
Trophic Cascade ◽  
Structural Equation ◽  
Trophic Cascades ◽  
Trophic Levels ◽  
Large Mammals ◽  
Top Down ◽  
Cascading Effects ◽  
Floral Visitor ◽  
Show Evidence ◽  
Floral Visitors

AbstractCascading effects of high trophic levels onto lower trophic levels have been documented in many ecosystems. Some studies also show evidence of extended trophic cascades, in which guilds dependent on lower trophic levels, but uninvolved in the trophic cascade themselves, are affected by the trophic cascade due to their dependence on lower trophic levels. Top-down effects of large mammals on plants could lead to a variety of extended trophic cascades on the many guilds dependent on plants, such as pollinators. In this study, floral-visitor and floral abundances and assemblages were quantified within a series of 1-ha manipulations of large-mammalian herbivore density in an African savanna. Top-down effects of large mammals on the composition of flowers available for floral visitors are first shown, using regressions of herbivore activity on metrics of floral and floral-visitor assemblages. An extended trophic cascade is also shown: the floral assemblage further altered the assemblage of floral visitors, according to a variety of approaches, including a structural equation modelling approach (model with an extended trophic cascade was supported over a model without, AICc weight = 0.984). Our study provides support for extended trophic cascades affecting floral visitors, suggesting that trophic cascades can have impacts throughout entire communities.

scholarly journals Diversity of caecal bacteria is altered in interleukin-10 gene-deficient mice before and after colitis onset and when fed polyunsaturated fatty acids

Microbiology ◽  
2010 ◽  
Vol 156 (11) ◽  
pp. 3306-3316 ◽  
Author(s):  
Bianca Knoch ◽  
Katia Nones ◽  
Matthew P. G. Barnett ◽  
Warren C. McNabb ◽  
Nicole C. Roy
Keyword(s):  
Fatty Acids ◽  
Bacterial Community ◽  
Polyunsaturated Fatty Acids ◽  
Expression Profiles ◽  
Clinical Signs ◽  
Gene Expression Profiles ◽  
Intestinal Bacteria ◽  
Interleukin 10 ◽  
Dietary Pufa ◽  
Pufa Supplementation

Interleukin-10 gene-deficient (Il10 –/–) mice show a hyper-reaction to normal intestinal bacteria and develop spontaneous colitis similar to that of human Crohn's disease when raised under conventional (but not germ-free) conditions. The lack of IL10 protein in these mice leads to changes in intestinal metabolic and signalling processes. The first aim of this study was to identify changes in the bacterial community of the caeca at 7 weeks of age (preclinical colitis) and at 12 weeks of age (when clinical signs of colitis are present), and establish if there were any changes that could be associated with the mouse genotype. We have previously shown that dietary n-3 and n-6 polyunsaturated fatty acids (PUFA) have anti-inflammatory effects and affect colonic gene expression profiles in Il10 –/– mice; therefore, we also aimed to test the effect of the n-3 PUFA eicosapentaenoic acid (EPA) and the n-6 PUFA arachidonic acid (AA) on the bacterial community of caeca in both Il10 –/– and C57 mice fed these diets. The lower number of caecal bacteria observed before colitis (7 weeks of age) in Il10 –/– compared to C57 mice suggests differences in the intestinal bacteria that might be associated with the genotype, and this could contribute to the development of colitis in this mouse model. The number and diversity of caecal bacteria increased after the onset of colitis (12 weeks of age). The increase in caecal Escherichia coli numbers in both inflamed Il10 –/– and healthy C57 mice might be attributed to the dietary PUFA (especially dietary AA), and thus not be a cause of colitis development. A possible protective effect of E. coli mediated by PUFA supplementation and associated changes in the bacterial environment could be a subject for further investigation to define the mode of action of PUFA in colitis.

scholarly journals Temperature is a dominant driver of distinct annual seasonality of leaf litter production of equatorial tropical rain forests

2018 ◽  
Author(s):  
Kanehiro Kitayama ◽  
Masayuki Ushio ◽  
Shin-ichiro Aiba
Keyword(s):  
Tropical Forests ◽  
Air Temperature ◽  
Forest Ecosystem ◽  
Trophic Levels ◽  
Litter Production ◽  
List Type ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Leaf Litterfall ◽  
Annual Periodicity

ABSTRACTIntra-annual periodicity of canopy photosynthetic activity and leaf development has been documented in seasonal and weakly-seasonal tropical forests in the Amazon and elsewhere. However, vegetative periodicity such as leaf flush and fall in apparently “aseasonal” equatorial tropical forests has not been well documented. Moreover, causal drivers of the vegetative periodicity in those forests have not been identified largely because of the difficulty in performing manipulative experiments targeting whole forest ecosystem dynamics.Here we show a distinct annual seasonality in canopy dynamics using a Fourier analysis with a statistical significance test on the long-term, fortnightly monitored dataset of leaf litterfall in nine evergreen tropical rain forests on Mount Kinabalu, Borneo. Statistically significant annual periodicity occurs across altitudes and soil types in all years irrespective of the year-to-year climatic variability, suggesting that fluctuations in regional climate rather than local micro-climatic, edaphic and/or biotic conditions cause the precise 1-year periodicity.We examine climatic factors that have causative effects on the distinct 1-year periodicity using the spectrum convergent cross mapping that we developed in the present study to distinguish causal relationships from seasonality-driven synchronization. According to the analysis, we find that mean daily air temperature is most strongly, causatively related to the 1-year periodicity of leaf litterfall. However, knowledge on ecophysiolocial and molecular mechanisms underlying temperature-control of tropical tree growth is limited and further studies are required to understand the detailed mechanisms.(Synthesis) We suggest that intra-annual temperature changes in association with the movement of the intertropical convergence zone cause the distinct annual vegetative periodicity. Because vegetative periodicity can be transmitted to the dynamics of higher trophic levels through a trophic cascade, interactions between vegetative periodicity and daily air temperature, not rainfall, would more strongly cause changes in the dynamics of equatorial tropical rain forests. Our results show that clear vegetative periodicity (i.e., annual seasonality) can be found in equatorial tropical rain forests under diverse local environments, and that air temperature is a more important factor than the other climate variables in the climate-forest ecosystem interactions.

scholarly journals Narrative Review of n-3 Polyunsaturated Fatty Acid Supplementation upon Immune Functions, Resolution Molecules and Lipid Peroxidation

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 662
Author(s):  
Gary P. Zaloga
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Fatty Acids ◽  
Fish Oil ◽  
Inflammatory Responses ◽  
Biological Effects ◽  
Scientific Evidence ◽  
Immune Functions ◽  
Pufa Supplementation ◽  
Fish Oil Supplementation

Fish oil supplementation is commonplace in human nutrition and is being used in both enteral and parenteral formulations during the treatment of patients with a large variety of diseases and immune status. The biological effects of fish oil are believed to result from their content of n-3 polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). These fatty acids are known to have numerous effects upon immune functions and are described as immunomodulatory. However, immunomodulatory is a nondescript term that encompasses immunostimulation and immunosuppression. The primary goal of this review is to better describe the immune effects of n-3 PUFA as they relate to immunostimulatory vs. immunosuppressive effects. One mechanism proposed for the immune effects of n-3 PUFA relates to the production of specialized pro-resolving mediators (SPMs). A second goal of this review is to evaluate the effects of n-3 PUFA supplementation upon production of SPMs. Although n-3 PUFA are stated to possess anti-oxidative properties, these molecules are highly oxidizable due to multiple double bonds and may increase oxidative stress. Thus, the third goal of this review is to evaluate the effects of n-3 PUFA upon lipid oxidation. We conclude, based upon current scientific evidence, that n-3 PUFA suppress inflammatory responses and most cellular immune responses such as chemotaxis, transmigration, antigen presentation, and lymphocyte functions and should be considered immunosuppressive. n-3 PUFA induced production of resolution molecules is inconsistent with many resolution molecules failing to respond to n-3 PUFA supplementation. n-3 PUFA supplementation is associated with increased lipid peroxidation in most studies. Vitamin E co-administration is unreliable for prevention of the lipid peroxidation. These effects should be considered when administering n-3 PUFA to patients that may be immunosuppressed or under high oxidative stress due to illness or other treatments.

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