Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults

PubMed Central

Comerford, Kevin B.

2015-01-01

In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older) from The NPD Group’s National Eating Trends® (NET®) database during 2011–2013; and the data were assessed using The NPD Group’s Nutrient Intake Database. Canned food consumers were placed into three groups: Frequent Can Users (≥6 canned items/week); n = 2584, Average Can Users (3–5 canned items/week); n = 4445, and Infrequent Can Users (≤2 canned items/week); n = 2732. The results provide evidence that Frequent Can Users consume more nutrient-dense food groups such as fruits, vegetables, dairy products, and protein-rich foods, and also have higher intakes of 17 essential nutrients including the shortfall nutrients—potassium, calcium and fiber—when compared to Infrequent Can Users. Therefore, in addition to fresh foods, diets higher in nutrient-dense canned food consumption can also offer dietary options which improve nutrient intakes and the overall diet quality of Americans. PMID:26184294

A model of phytoplankton blooms.

PubMed

Huppert, Amit; Blasius, Bernd; Stone, Lewi

2002-02-01

A simple model that describes the dynamics of nutrient-driven phytoplankton blooms is presented. Apart from complicated simulation studies, very few models reported in the literature have taken this "bottom-up" approach. Yet, as discussed and justified from a theoretical standpoint, many blooms are strongly controlled by nutrients rather than by higher trophic levels. The analysis identifies an important threshold effect: a bloom will only be triggered when nutrients exceed a certain defined level. This threshold effect should be generic to both natural blooms and most simulation models. Furthermore, predictions are given as to how the peak of the bloom Pmax is determined by initial conditions. A number of counterintuitive results are found. In particular, it is shown that increasing initial nutrient or phytoplankton levels can act to decrease Pmax. Correct predictions require an understanding of such factors as the timing of the bloom and the period of nutrient buildup before the bloom.

Differential sensitivity of spinach and amaranthus to enhanced UV-B at varying soil nutrient levels: association with gas exchange, UV-B-absorbing compounds and membrane damage.

PubMed

Singh, Suruchi; Agrawal, Madhoolika; Agrawal, S B

2013-07-01

The metabolic reasons associated with differential sensitivity of C3 and C4 plant species to enhanced UV-B under varying soil nutrient levels are not well understood. In the present study, spinach (Spinacia oleracea L. var All Green), a C3 and amaranthus (Amaranthus tricolor L. var Pusa Badi Chaulai), a C4 plant were subjected to enhanced UV-B (280-315 nm; 7.2 kJ m(-2) day(-1)) over ambient under varying soil nutrient levels. The nutrient amendments were recommended Nitrogen (N), Phosphorus (P), Potassium (K), 1.5× recommended NPK, 1.5× recommended N and 1.5× recommended K. Enhanced UV-B negatively affected both the species at all nutrient levels, but the reductions varied with nutrient concentration and combinations. Reductions in photosynthetic rate, stomatal conductance and chlorophyll content were significantly more in spinach compared with amaranthus. The reduction in photosynthetic rate was maximum at 1.5× recommended K and minimum in 1.5× NPK amended plants. The oxidative damage to membranes measured in terms of malondialdehyde content was significantly higher in spinach compared with amaranthus. Enhanced UV-B reduced SOD activity in both the plants except in amaranthus at 1.5× recommended K. POX activity increased under enhanced UV-B at all nutrient levels in amaranthus, but only at 1.5× K in spinach. Amaranthus had significantly higher UV-B-absorbing compounds than spinach even under UV-B stress. Lowest reductions in yield and total biomass under enhanced UV-B compared with ambient were observed in amaranthus grown at 1.5× recommended NPK. Enhanced UV-B did not significantly change the nitrogen use efficiency in amaranthus at all NPK levels, but reduced in spinach except at 1.5× K. These findings suggest that the differential sensitivity of the test species under enhanced UV-B at varying nutrient levels is due to varying antioxidative and UV-B screening capacity, and their ability to utilize nutrients. Amaranthus tolerated enhanced UV-B stress more than spinach at all nutrient levels and 1.5× recommended NPK lowered the sensitivity maximally to enhanced UV-B with respect to photosynthesis, biomass and yield. PCA score has also confirmed the lower sensitivity of amaranthus compared with spinach with respect to the measured physiological and biochemical parameters.

Pheromonal regulation of starvation resistance in honey bee workers ( Apis mellifera)

NASA Astrophysics Data System (ADS)

Fischer, Patrick; Grozinger, Christina M.

2008-08-01

Most animals can modulate nutrient storage pathways according to changing environmental conditions, but in honey bees nutrient storage is also modulated according to changing behavioral tasks within a colony. Specifically, bees involved in brood care (nurses) have higher lipid stores in their abdominal fat bodies than forager bees. Pheromone communication plays an important role in regulating honey bee behavior and physiology. In particular, queen mandibular pheromone (QMP) slows the transition from nursing to foraging. We tested the effects of QMP exposure on starvation resistance, lipid storage, and gene expression in the fat bodies of worker bees. We found that indeed QMP-treated bees survived much longer compared to control bees when starved and also had higher lipid levels. Expression of vitellogenin RNA, which encodes a yolk protein that is found at higher levels in nurses than foragers, was also higher in the fat bodies of QMP-treated bees. No differences were observed in expression of genes involved in insulin signaling pathways, which are associated with nutrient storage and metabolism in a variety of species; thus, other mechanisms may be involved in increasing the lipid stores. These studies demonstrate that pheromone exposure can modify nutrient storage pathways and fat body gene expression in honey bees and suggest that chemical communication and social interactions play an important role in altering metabolic pathways.

Are physical activity levels linked to nutrient adequacy? Implications for cancer risk.

PubMed

Csizmadi, Ilona; Kelemen, Linda E; Speidel, Thomas; Yuan, Yan; Dale, Laura C; Friedenreich, Christine M; Robson, Paula J

2014-01-01

Cancer prevention guidelines recommend a healthy body mass index, physical activity, and nutrient intake from food rather than supplements. Sedentary individuals may restrict energy intake to prevent weight gain and in so doing may compromise nutritional intake. We conducted a cross-sectional analysis to determine if adequacy of micronutrients is linked to physical activity levels (PALs) in healthy-weight adults. Tomorrow Project participants in Alberta, Canada (n = 5333), completed past-year diet and physical activity questionnaires. The percent meeting Dietary Reference Intakes (DRIs) was reported across low and high PAL groups, and the relation between PAL and percent achieved DRI was determined using multiple linear regression analyses. Overall, <50% of healthy-weight participants met DRIs for folate, calcium, and vitamin D. Percent achieved DRI increased linearly with increasing PAL in both genders (P < 0.01). A hypothetical increase in PAL from 1.4 to 1.9 was associated with a DRI that was 8%-13% higher for folate and vitamin C (men) and 5%-15% higher for calcium and iron (women). Healthy-weight adults at higher PALs appear more likely to meet DRIs for potential cancer-preventing nutrients. The benefits of higher PALs may extend beyond the usual benefits attributed to physical activity to include having a more favorable impact on nutrient adequacy.

Do elevated nutrients and organic carbon on Philippine reefs increase the prevalence of coral disease?

NASA Astrophysics Data System (ADS)

Kaczmarsky, L.; Richardson, L. L.

2011-03-01

Characterizations of Philippine coral diseases are very limited. The two most common, ulcerative white spot disease (UWS) and massive Porites growth anomalies (MPGA), target the genus Porites, a dominant reef-building genus. This is the first investigation in the Philippines to detect positive correlations between coral disease, nutrient levels, and organic carbon. A total of 5,843 Porites colonies were examined. Water and sediment samples were collected for analyses of nutrients (total nitrogen and phosphorus) and total organic carbon at 15 sites along a 40.5 km disease gradient, which was previously shown to positively correlate with human population levels. Results suggest that outbreaks of UWS and MPGAs are driven by elevated nutrient and organic carbon levels. Although the variables analyzed could be proxies for other causative agents (e.g., high sediment levels), the results provide quantitative evidence linking relatively higher coral disease prevalence to an anthropogenically impacted environment.

Light, nutrients, and food-chain length constrain planktonic energy transfer efficiency across multiple trophic levels

PubMed Central

Dickman, Elizabeth M.; Newell, Jennifer M.; González, María J.; Vanni, Michael J.

2008-01-01

The efficiency of energy transfer through food chains [food chain efficiency (FCE)] is an important ecosystem function. It has been hypothesized that FCE across multiple trophic levels is constrained by the efficiency at which herbivores use plant energy, which depends on plant nutritional quality. Furthermore, the number of trophic levels may also constrain FCE, because herbivores are less efficient in using plant production when they are constrained by carnivores. These hypotheses have not been tested experimentally in food chains with 3 or more trophic levels. In a field experiment manipulating light, nutrients, and food-chain length, we show that FCE is constrained by algal food quality and food-chain length. FCE across 3 trophic levels (phytoplankton to carnivorous fish) was highest under low light and high nutrients, where algal quality was best as indicated by taxonomic composition and nutrient stoichiometry. In 3-level systems, FCE was constrained by the efficiency at which both herbivores and carnivores converted food into production; a strong nutrient effect on carnivore efficiency suggests a carryover effect of algal quality across 3 trophic levels. Energy transfer efficiency from algae to herbivores was also higher in 2-level systems (without carnivores) than in 3-level systems. Our results support the hypothesis that FCE is strongly constrained by light, nutrients, and food-chain length and suggest that carryover effects across multiple trophic levels are important. Because many environmental perturbations affect light, nutrients, and food-chain length, and many ecological services are mediated by FCE, it will be important to apply these findings to various ecosystem types. PMID:19011082

Simultaneous remediation of nutrients from liquid anaerobic digestate and municipal wastewater by the microalga Scenedesmus sp. AMDD grown in continuous chemostats.

PubMed

Dickinson, K E; Bjornsson, W J; Garrison, L L; Whitney, C G; Park, K C; Banskota, A H; McGinn, P J

2015-01-01

The primary aim of this study was to investigate the capacity of a microalga, Scenedesmus sp. AMDD, to remediate nutrients from municipal wastewater, either as the sole nutrient source or after blending with wastewater obtained from the anaerobic digestion of swine manure. A complimentary aim was to study and define the effects of these wastewaters on microalgal growth, biomass productivity and composition which have important implications for a commercial biofuels production system. A microalga, Scenedesmus sp. AMDD, was grown in continuous chemostats in municipal wastewater or wastewater supplemented with 1·6× or 2·4× higher levels of nitrogen (N) obtained through supplementation with anaerobic digestates. Biomass productivity increased with increasing nutrient supplementation, but was limited by light at high cell densities. Cellular quotas of carbon (C), nitrogen and phosphorus (P) all increased in direct proportion to their concentrations in the combined wastewaters. At higher cell densities, total carbohydrate decreased while protein increased. Fatty acid content remained relatively constant. Under high nutrient levels, the fatty acid profiles contained a higher concentration of polyunsaturated fatty acids at the expense of monounsaturated fatty acids. Chlorophyll a was 2·5 times greater in the treatment of greatest nutrient supplementation compared to the treatment with the least. Ammonium (NH4(+)) and phosphate (PO4(3-)) were completely removed by algal growth in all treatments and with maximal removal rates of 41·2 mg N l(-1) d(-1) and 6·7 mg P l(-1) d(-1) observed in wastewater amended with 2·4× higher N level. The study is the first to report stable, long-term continuous algal growth and productivity obtained by combining wastewaters of different sources. The study is supported by detailed analyses of the composition of the cultivated biomass and links composition to the nutrient and light availabilities in the cultures. Simultaneous remediation of these wastes by algal growth is discussed as a strategy for the valorization of the biomass. © 2014 Her Majesty the Queen in Right of Canada © 2014 The Society for Applied Microbiology. Reproduced with the permission of the Minister of Industry.

Evergreen shrub traits and peatland carbon cycling under high nutrient load

NASA Astrophysics Data System (ADS)

Larmola, Tuula; Bui, Vi; Bubier, Jill L.; Wang, Meng; Murphy, Meaghan; Moore, Tim R.

2016-04-01

The reactive nitrogen (N) assimilated by plants is usually invested in chlorophyll to improve light harvesting capacity and in soluble proteins such as Rubisco to enhance carbon (C) assimilation. We studied the effects of simulated atmospheric N deposition on different traits of two evergreen shrubs Chamaedaphne calyculata and Rhododendron groenlandicum in a nutrient-poor Mer Bleue Bog, Canada that has been fertilized with N as NO3 and NH4 (2-8 times ambient annual wet deposition) with or without phosphorus (P) and potassium (K) for 7-12 years. We examined how nutrient addition influences the plant performance at leaf and canopy level and linked the trait responses with ecosystem C cycling. At the leaf level, we measured physiological and biochemical traits: CO2 exchange and chlorophyll fluorescence, an indicator of plant stress in terms of light harvesting capacity; and to study changes in photosynthetic nutrient use efficiency, we also determined the foliar chlorophyll, N, and P contents. At the canopy level, we examined morphological and phenological traits: growth responses and leaf longevity during two growing seasons. Regardless of treatment, the majority of leaves showed no signs of stress in terms of light harvesting capacity. The plants were N saturated: with increasing foliar N content, the higher proportion of N was not used in photosynthesis. Foliar net CO2 assimilation rates did not differ significantly among treatments, but the additions of N, P, and K together resulted in higher respiration rates. The analysis of the leaf and canopy traits showed that the two shrubs had different strategies: C. calyculata was more responsive to nutrient additions, more deciduous-like, whereas R. groenlandicum maintained evergreen features under nutrient load, shedding its leaves even later in the season. In all, simulated atmospheric N deposition did not benefit the photosynthetic apparatus of the dominant shrubs, but resulted in higher foliar respiration, contributing to stress and a weaker ecosystem C sink. Thus, elevated atmospheric deposition of nutrients to these systems may endanger C storage in peatlands.

Chemical characterization of biochar and assessment of the nutrient dynamics by means of preliminary plant growth tests.

PubMed

Prasad, Munoo; Tzortzakis, Nikos; McDaniel, Nicola

2018-06-15

Biochar can be produced from several organic sources with varying nutrients and metal concentrations. Four commercial grade biochars were evaluated as peat substitute. Biochars were characterised for plant nutrients and for biological stability. The results showed that there were negligible quantities of N and P and generally high levels of K and high biological stability. When these materials were mixed with peat at 10, 25 and 50% and nutrients were added to bring them to the same level of nutrients as in fertilized peat, it was found that biochar mixtures considerably reduced the levels of calcium chloride/DTPA (CAT) extractable N (including nitrate), P, and electrical conductivity- greater extent with higher rates of biochar addition except for K. The pH and K levels were increased with biochar addition. The drop in EC has important implications regarding the use of other materials used to dilute peat, for example, composted green waste, the rate of dilution is limited due to high EC and biochar addition gives the potential for higher peat dilution of these materials. Nitrate and phosphorus are very vulnerable to leaching of these nutrients in the environment in peat substrates and the binding of these by biochar has implication for leaching and nutrient application strategy. Root development using Cress test and tomato plant height and biomass using containers, were in some cases better than peat indicating that biochar could be used to dilute peat e.g. for seedling production where root development and rapid growth are very important. Application of biochars resulted in a marked reduction of N (and P) in the plant. There were significant correlation between CAT extractable N and P and corresponding plant concentration, indicating the standard growing media test, CAT, would be suitable for assessing the nutrient status of peat biochar mixes. Copyright © 2017 Elsevier Ltd. All rights reserved.

LARVAL SALAMANDER GROWTH RESPONDS TO ENRICHMENT OF A NUTRIENT POOR HEADWATER STREAM

EPA Science Inventory

While many studies have measured effects of nutrient enrichment on higher trophic levels in grazing food webs, few such studies exist for detritus-based systems. We measured effects of nitrogen and phosphorus addition on growth of larval Eruycea wilderae in a heterotrophic head...

Organic foods contain higher levels of certain nutrients, lower levels of pesticides, and may provide health benefits for the consumer.

PubMed

Crinnion, Walter J

2010-04-01

The multi-billion dollar organic food industry is fueled by consumer perception that organic food is healthier (greater nutritional value and fewer toxic chemicals). Studies of the nutrient content in organic foods vary in results due to differences in the ground cover and maturity of the organic farming operation. Nutrient content also varies from farmer to farmer and year to year. However, reviews of multiple studies show that organic varieties do provide significantly greater levels of vitamin C, iron, magnesium, and phosphorus than non-organic varieties of the same foods. While being higher in these nutrients, they are also significantly lower in nitrates and pesticide residues. In addition, with the exception of wheat, oats, and wine, organic foods typically provide greater levels of a number of important antioxidant phytochemicals (anthocyanins, flavonoids, and carotenoids). Although in vitro studies of organic fruits and vegetables consistently demonstrate that organic foods have greater antioxidant activity, are more potent suppressors of the mutagenic action of toxic compounds, and inhibit the proliferation of certain cancer cell lines, in vivo studies of antioxidant activity in humans have failed to demonstrate additional benefit. Clear health benefits from consuming organic dairy products have been demonstrated in regard to allergic dermatitis.

Methyl-Donor and Cofactor Nutrient Intakes in the First 2–3 Years and Global DNA Methylation at Age 4: A Prospective Cohort Study

PubMed Central

Taylor, Rachael M.; Smith, Roger; Collins, Clare E.; Mossman, David; Wong-Brown, Michelle W.; Chan, Eng-Cheng; Evans, Tiffany-Jane; Attia, John R.; Smith, Tenele; Butler, Trent

2018-01-01

Background: During the early postnatal period, the impact of nutrition on DNA methylation has not been well studied in humans. The aim was to quantify the relationship between one-carbon metabolism nutrient intake during the first three years of life and global DNA methylation levels at four years. Design: Childhood dietary intake was assessed using infant feeding questionnaires, food frequency questionnaires, 4-day weighed food records and 24-h food records. The dietary records were used to estimate the intake of methionine, folate, vitamins B2, B6 and B12 and choline. The accumulative nutrient intake specific rank from three months to three years of age was used for analysis. Global DNA methylation (%5-methyl cytosines (%5-mC)) was measured in buccal cells at four years of age, using an enzyme-linked immunosorbent assay (ELISA) commercial kit. Linear regression models were used to quantify the statistical relationships. Results: Data were collected from 73 children recruited from the Women and their Children’s Health (WATCH) study. No association was found between one-carbon metabolism nutrient intake and global DNA methylation levels (P 0.05). Global DNA methylation levels in males were significantly higher than in females (median %5-mC: 1.82 vs. 1.03, males and females respectively, (P 0.05)). Conclusion: No association was found between the intake of one-carbon metabolism nutrients during the early postnatal period and global DNA methylation levels at age four years. Higher global DNA methylation levels in males warrants further investigation. PMID:29495543

Living status and frequency of eating out-of-home foods in relation to nutritional adequacy in 4,017 Japanese female dietetic students aged 18-20 years: A multicenter cross-sectional study.

PubMed

Kobayashi, Satomi; Asakura, Keiko; Suga, Hitomi; Sasaki, Satoshi

2017-06-01

Living status (e.g., living with family or alone) may affect dietary habits. We compared nutritional adequacy according to living status and the frequency of eating out-of-home foods in young Japanese women. Female dietetic students (aged 18-20 years; n = 4,017) participated in a cross-sectional multicenter study, which was conducted in 85 dietetic schools in 35 of 47 prefectures in Japan. Habitual dietary intake was assessed with a validated diet history questionnaire. Nutritional adequacy was determined based on the Dietary Reference Intakes for Japanese, 2015, for two goals: preventing non-communicable chronic disease (a tentative dietary goal for preventing lifestyle-related diseases [DG] that tracks five nutrients) and avoiding insufficient intake of mainly vitamins and minerals (estimated average requirement [EAR] that tracks 14 nutrients). Women living with their family were less likely to meet DG nutrient levels, but more likely to meet EAR nutrient levels compared with those living alone. In contrast, women living alone had more inadequate nutrients with EAR and fewer nutrients with not-meeting DG than those living with families. A higher frequency of eating out-of-home was significantly associated with a higher prevalence of not-meeting DG nutrient levels only in the women living with their family. The prevalence of nutritional adequacy varied based on living status. In addition, women living with their family and those with a high frequency of eating out-of-home foods had the highest prevalence of not-meeting DG. Effective ways of improving dietary quality among young Japanese women differ by living status. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Biochar-enhanced composts reduce the potential leaching of nutrients and heavy metals and suppress plant-parasitic nematodes in excessively fertilized cucumber soils.

PubMed

Cao, Yune; Gao, Yanming; Qi, Yanbin; Li, Jianshe

2018-03-01

Excessive fertilization is a common agricultural practice that has largely reduced soil nutrient retention capacity and led to nutrient leaching in China. To reduce nutrient leaching, in this study, we evaluated the application of biochar, compost, and biochar-compost on soil properties, leaching water quality, and cucumber plant growth in soils with different nutrient levels. In general, the concentrations of nutrients and heavy metals in leaching water were higher under high-nutrient conditions than under low-nutrient conditions. Both biochar and compost efficiently enhanced soil cation exchange capacity (CEC), water holding capacity (WHC), and microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP), reduced the potential leaching of nutrients and heavy metals, and improved plant growth. The efficiency of biochar and compost in soil CEC, WHC, MBC, MBN, and MBP and plant growth was enhanced when applied jointly. In addition, biochar and biochar-enhanced compost efficiently suppressed plant-parasitic nematode infestation in a soil with high levels of both N and P. Our results suggest that biochar-enhanced compost can reduce the potential environmental risks in excessively fertilized vegetable soils.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber.

PubMed

Wheeler, R M; Mackowiak, C L; Sager, J C; Knott, W M; Berry, W L

1996-01-01

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

1996-01-01

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber

NASA Astrophysics Data System (ADS)

Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

Interactions between temperature and nutrients across levels of ecological organization.

PubMed

Cross, Wyatt F; Hood, James M; Benstead, Jonathan P; Huryn, Alexander D; Nelson, Daniel

2015-03-01

Temperature and nutrient availability play key roles in controlling the pathways and rates at which energy and materials move through ecosystems. These factors have also changed dramatically on Earth over the past century as human activities have intensified. Although significant effort has been devoted to understanding the role of temperature and nutrients in isolation, less is known about how these two factors interact to influence ecological processes. Recent advances in ecological stoichiometry and metabolic ecology provide a useful framework for making progress in this area, but conceptual synthesis and review are needed to help catalyze additional research. Here, we examine known and potential interactions between temperature and nutrients from a variety of physiological, community, and ecosystem perspectives. We first review patterns at the level of the individual, focusing on four traits--growth, respiration, body size, and elemental content--that should theoretically govern how temperature and nutrients interact to influence higher levels of biological organization. We next explore the interactive effects of temperature and nutrients on populations, communities, and food webs by synthesizing information related to community size spectra, biomass distributions, and elemental composition. We use metabolic theory to make predictions about how population-level secondary production should respond to interactions between temperature and resource supply, setting up qualitative predictions about the flows of energy and materials through metazoan food webs. Last, we examine how temperature-nutrient interactions influence processes at the whole-ecosystem level, focusing on apparent vs. intrinsic activation energies of ecosystem processes, how to represent temperature-nutrient interactions in ecosystem models, and patterns with respect to nutrient uptake and organic matter decomposition. We conclude that a better understanding of interactions between temperature and nutrients will be critical for developing realistic predictions about ecological responses to multiple, simultaneous drivers of global change, including climate warming and elevated nutrient supply. © 2014 John Wiley & Sons Ltd.

CO2 and nutrient-driven changes across multiple levels of organization in Zostera noltii ecosystems

NASA Astrophysics Data System (ADS)

Martínez-Crego, B.; Olivé, I.; Santos, R.

2014-12-01

Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low- and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and context-dependent, being mediated by epiphyte overgrowth rather than by direct effects on plant biochemistry. Overall, we found that the responses of seagrass meadows to individual and interactive effects of CO2 and nutrient enrichment varied depending on interactions among species and connections between organization levels.

Nutrient-induced modifications of wood anatomical traits of Alchornea lojaensis (Euphorbiaceae)

NASA Astrophysics Data System (ADS)

Spannl, Susanne; Homeier, Jürgen; Bräuning, Achim

2016-05-01

Regarding woody plant responses on higher atmospheric inputs of the macronutrients nitrogen (N) and phosphorous (P) on tropical forests in the future, an adaptive modification of wood anatomical traits on the cellular level of woody plants is expected. As part of an interdisciplinary nutrient manipulation experiment (NUMEX) carried out in Southern Ecuador, we present here the first descriptive and quantitative wood anatomical analysis of the tropical evergreen tree species Alchornea lojaensis (Euphorbiaceae). We sampled branch wood of nine individual trees belonging to treatments with N fertilization, N+P fertilization, and a control group, respectively. Quantitative evaluations of eleven different vessel parameters were conducted. The results showed that this endemic tree species will be able to adapt well to the future effects of climate change and higher nutrient deposition. This was firstly implied by an increase in vessel diameter and consequently a higher theo. area-specific hydraulic conductivity with higher nutrient availability. Secondly, the percentage of small vessels (0-20µm diameter) strongly increased with fertilization. Thirdly, the vessel arrangement (solitary vessels vs. multiple vessel groupings) changed towards a lower percentage of solitary vessel fraction (VS), and concurrently towards a higher total vessel grouping index (VG) and a higher mean group size of non-solitary vessels (VM) after N and N+P addition. We conclude that higher nutrient availability of N and N+P triggered higher foliage amount and water demand, leading to higher cavitation risk in larger vessels. This is counteracted by a stronger grouping of vessels with smaller risk of cavitation to ensure water supply during drier periods that are expected to occur in higher frequency in the near future.

Spatiotemporal patterns of phytoplankton composition and abundance in the Maryland Coastal Bays: The influence of freshwater discharge and anthropogenic activities

NASA Astrophysics Data System (ADS)

Oseji, Ozuem F.; Chigbu, Paulinus; Oghenekaro, Efeturi; Waguespack, Yan; Chen, Nianhong

2018-07-01

The spatial and temporal variations in phytoplankton abundance and community structure in the northern and southern parts of the Maryland Coastal Bays (MCBs) that differ in anthropogenic activities and hydrological characteristics were studied in 2012 and 2013 using photosynthetic pigments as biomarkers. Phytoplankton pigment biomass and diversity were generally higher in the northern bays that receive high nutrient input from St. Martin River, than in the southern bays where nutrient levels were comparatively low. Sites close to the mouths of tributaries in northern and southern bays had higher nutrient levels, which favored the development of dinoflagellates, and nano- and picophytoplankton, than sites closer to the inlets. The microplankton dominated the phytoplankton community in spring (>90%) and decreased in relative abundance into fall (<60%) whereas nanoplankton peaked in summer or fall. Picoplankton relative abundance increased from late spring (<10%, March 2012 & 2013) to summer (40%, July 2012 and August 2013) and was correlated positively with NH4+ and negatively with salinity. The observed spatial and seasonal patterns of phytoplankton relative abundance and diversity are likely due to changes in nutrient concentrations and ratios, driven by variations in freshwater discharge, and selective grazing of phytoplankton. Water quality management in the MCBs should continue to focus on reducing nutrient inputs into the bays.

High intensity, short duration rotational grazing on reclaimed cool season tall fescue/legume pastures: II. Forage production, soil and plant tissue comparisons between grazed and ungrazed pastures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, K.E.; Erickson, W.R.; Bonine, R.C.

The Midway Mine is located 50 miles south of Kansas City, Kansas straddling the border of Kansas and Missouri. The Pittsburg & Midway Coal Mining Co. mined the area until 1989, when the mine was closed and reclaimed. Approximately 3,750 acres were topsoiled and revegetated with a cool season tall fescue/legume pasture. High intensity, short duration rotational grazing has become the preferred management practice on these pastures. This study evaluated soil and vegetation data collected on 1,250 acres of pasture which was grazed by about 550 cow/calf units. Ongoing monitoring programs are evaluating the effects of rotational grazing. Soil testingmore » includes macro-nutrients, micro-nutrients and microbial activity. Plant tissue analyses monitor levels of principal macro-nutrients and micro-nutrients. Vegetation monitoring consists of measuring forage production. Results were contrasted between pregrazing and postgrazing, and grazed and ungrazed pasture. Agronomic data from the grazed versus ungrazed treatments documented the following results: (1) higher levels of plant tissue nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; (2) higher microbial activity; (3) similar levels of soil nitrate, phosphorus, potassium, calcium, magnesium, sodium and sulfur; and (4) increased biomass production.« less

Modelling potential production of macroalgae farms in UK and Dutch coastal waters

NASA Astrophysics Data System (ADS)

van der Molen, Johan; Ruardij, Piet; Mooney, Karen; Kerrison, Philip; O'Connor, Nessa E.; Gorman, Emma; Timmermans, Klaas; Wright, Serena; Kelly, Maeve; Hughes, Adam D.; Capuzzo, Elisa

2018-02-01

There is increasing interest in macroalgae farming in European waters for a range of applications, including food, chemical extraction for biofuel production. This study uses a 3-D numerical model of hydrodynamics and biogeochemistry to investigate potential production and environmental effects of macroalgae farming in UK and Dutch coastal waters. The model included four experimental farms in different coastal settings in Strangford Lough (Northern Ireland), in Sound of Kerrera and Lynn of Lorne (north-west Scotland) and in the Rhine plume (the Netherlands), as well as a hypothetical large-scale farm off the UK north Norfolk coast. The model could not detect significant changes in biogeochemistry and plankton dynamics at any of the farm sites averaged over the farming season. The results showed a range of macroalgae growth behaviours in response to simulated environmental conditions. These were then compared with in situ observations where available, showing good correspondence for some farms and less good correspondence for others. At the most basic level, macroalgae production depended on prevailing nutrient concentrations and light conditions, with higher levels of both resulting in higher macroalgae production. It is shown that under non-elevated and interannually varying winter nutrient conditions, farming success was modulated by the timings of the onset of increasing nutrient concentrations in autumn and nutrient drawdown in spring. Macroalgae carbohydrate content also depended on nutrient concentrations, with higher nutrient concentrations leading to lower carbohydrate content at harvest. This will reduce the energy density of the crop and thus affect its suitability for conversion into biofuel. For the hypothetical large-scale macroalgae farm off the UK north Norfolk coast, the model suggested high, stable farm yields of macroalgae from year to year with substantial carbohydrate content and limited environmental effects.

Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens

NASA Astrophysics Data System (ADS)

Gharajehdaghipour, Tazarve; Roth, James D.; Fafard, Paul M.; Markham, John H.

2016-04-01

Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ15N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra.

Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens.

PubMed

Gharajehdaghipour, Tazarve; Roth, James D; Fafard, Paul M; Markham, John H

2016-04-05

Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ(15)N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra.

Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens

PubMed Central

Gharajehdaghipour, Tazarve; Roth, James D.; Fafard, Paul M.; Markham, John H.

2016-01-01

Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ15N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra. PMID:27045973

Nutrient Presses and Pulses Differentially Impact Plants, Herbivores, Detritivores and Their Natural Enemies

PubMed Central

Murphy, Shannon M.; Wimp, Gina M.; Lewis, Danny

2012-01-01

Anthropogenic nutrient inputs into native ecosystems cause fluctuations in resources that normally limit plant growth, which has important consequences for associated food webs. Such inputs from agricultural and urban habitats into nearby natural systems are increasing globally and can be highly variable, spanning the range from sporadic to continuous. Despite the global increase in anthropogenically-derived nutrient inputs into native ecosystems, the consequences of variation in subsidy duration on native plants and their associated food webs are poorly known. Specifically, while some studies have examined the effects of nutrient subsidies on native ecosystems for a single year (a nutrient pulse), repeated introductions of nutrients across multiple years (a nutrient press) better reflect the persistent nature of anthropogenic nutrient enrichment. We therefore contrasted the effects of a one-year nutrient pulse with a four-year nutrient press on arthropod consumers in two salt marshes. Salt marshes represent an ideal system to address the differential impacts of nutrient pulses and presses on ecosystem and community dynamics because human development and other anthropogenic activities lead to recurrent introductions of nutrients into these natural systems. We found that plant biomass and %N as well as arthropod density fell after the nutrient pulse ended but remained elevated throughout the nutrient press. Notably, higher trophic levels responded more strongly than lower trophic levels to fertilization, and the predator/prey ratio increased each year of the nutrient press, demonstrating that food web responses to anthropogenic nutrient enrichment can take years to fully manifest themselves. Vegetation at the two marshes also exhibited an apparent tradeoff between increasing %N and biomass in response to fertilization. Our research emphasizes the need for long-term, spatially diverse studies of nutrient enrichment in order to understand how variation in the duration of anthropogenic nutrient subsidies affects native ecosystems. PMID:22952814

Shoot Development and Extension of Quercus serrata Saplings in Response to Insect Damage and Nutrient Conditions

PubMed Central

MIZUMACHI, ERI; MORI, AKIRA; OSAWA, NAOYA; AKIYAMA, REIKO; TOKUCHI, NAOKO

2006-01-01

• Background and Aims Plants have the ability to compensate for damage caused by herbivores. This is important to plant growth, because a plant cannot always avoid damage, even if it has developed defence mechanisms against herbivores. In previous work, we elucidated the herbivory-induced compensatory response of Quercus (at both the individual shoot and whole sapling levels) in both low- and high-nutrient conditions throughout one growing season. In this study, we determine how the compensatory growth of Quercus serrata saplings is achieved at different nutrient levels. • Methods Quercus serrata saplings were grown under controlled conditions. Length, number of leaves and percentage of leaf area lost on all extension units (EUs) were measured. • Key Results Both the probability of flushing and the length of subsequent EUs significantly increased with an increase in the length of the parent EU. The probability of flushing increased with an increase in leaf damage of the parent EU, but the length of subsequent EUs decreased. This indicates that EU growth is fundamentally regulated at the individual EU level. The probabilities of a second and third flush were significantly higher in plants in high-nutrient soil than those in low-nutrient soil. The subsequent EUs of damaged saplings were also significantly longer at high-nutrient conditions. • Conclusions An increase in the probability of flushes in response to herbivore damage is important for damaged saplings to produce new EUs; further, shortening the length of EUs helps to effectively reproduce foliage lost by herbivory. The probability of flushing also varied according to soil nutrient levels, suggesting that the compensatory growth of individual EUs in response to local damage levels is affected by the nutrients available to the whole sapling. PMID:16709576

Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis.

PubMed

Velthuis, Mandy; van Deelen, Emma; van Donk, Ellen; Zhang, Peiyu; Bakker, Elisabeth S

2017-01-01

Human activity is currently changing our environment rapidly, with predicted temperature increases of 1-5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus). In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition consistently leads to decreased carbon:nutrient ratios, elevated temperature does not change submerged aquatic plant carbon:nutrient stoichiometry in a consistent manner. This effect is rather dependent on nutrient availability and may be species-specific. As changes in the carbon:nutrient stoichiometry of submerged aquatic plants can impact the transfer of energy to higher trophic levels, these results suggest that eutrophication may enhance plant consumption and decomposition, which could in turn have consequences for carbon sequestration.

[Effect of atmospheric CO2 concentration and nitrogen application level on absorption and transportation of nutrient elements in oilseed rape].

PubMed

Wang, Wen-ming; Zhang, Zhen-hua; Song, Hai-xing; Liu, Qiang; Rong, Xiang-min; Guan, Chun-yun; Zeng, Jing; Yuan, Dan

2015-07-01

Effect of elevated atmospheric-CO2 (780 µmol . mol-1) on the absorption and transportation of secondary nutrient elements (calcium, magnesium, sulphur) and micronutrient elements (iron, manganese, zinc, molybdenum and boron) in oilseed rape at the stem elongation stage were studied by greenhouse simulated method. Compared with the ambient CO2 condition, the content of Zn in stem was increased and the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with no nitrogen (N) application; the contents of Ca, S, B and Zn were increased, and the contents of Mg, Mn, Mo and Fe were decreased under the elevated atmospheric CO2 with N application (0.2 g N . kg-1 soil); except the content of Mo in leaf was increased, the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with two levels of N application. Compared with the ambient CO2 condition, the amounts of Ca and S relative to the total amount of secondary nutrient elements in stem and the amounts of B and Zn relative to the total amount of micronutrient elements in stem were increased under the elevated-CO2 treatment with both levels of N application, and the corresponding values of Mg, Fe, Mn and Mo were decreased; no-N application treatment increased the proportion of Ca distributed into the leaves, and the proportion of Mg distributed into leaves was increased by the normal-N application level; the proportions of Mn, Zn and Mo distributed into the leaves were increased at both N application levels. Without N application, the elevation of atmospheric CO2 increased the transport coefficients of SFe, Mo and SS,B, but decreased the transport coefficients of SMg,Fe, SMg, Mn and SS,Fe, indicating the proportions of Mo, S transported into the upper part of plant tissues was higher than that of Fe, and the corresponding value of B was higher than that observed for S, the corresponding value of Mg was higher than that of Fe and Mn. Under normal-N application, the elevation of atmospheric CO2 increased the transport coefficients of SMg,Fe, SMg,Mn and SS,B, but decreased the transport coefficients of SCa, Mg, SFe,Mo and SS,Fe indicating the proportions of Fe, Mn and Ca transported into the upper part of plant tissues was higher than that of Mg; the corresponding value of B was higher than that observed for S, the corresponding value of Fe was higher than that of Mo, and the corresponding value of S was higher than that of Fe.

Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khangaonkar, Tarang; Sackmann, Brandon; Long, Wen

2012-08-14

Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence of hypoxia in some basins. However, the relative contributions of loads entering Puget Sound from natural and anthropogenic sources, and the effects of exchange flow from the Pacific Ocean are not well understood. Development of a quantitative model of Puget Sound is thus presented to help improve our understanding of the annual biogeochemical cycles in this system using the unstructured grid Finite-Volume Coastal Ocean Model framework and the Integrated Compartment Model (CE-QUAL-ICM) water quality kinetics.more » Results based on 2006 data show that phytoplankton growth and die-off, succession between two species of algae, nutrient dynamics, and dissolved oxygen in Puget Sound are strongly tied to seasonal variation of temperature, solar radiation, and the annual exchange and flushing induced by upwelled Pacific Ocean waters. Concentrations in the mixed outflow surface layer occupying approximately 5–20 m of the upper water column show strong effects of eutrophication from natural and anthropogenic sources, spring and summer algae blooms, accompanied by depleted nutrients but high dissolved oxygen levels. The bottom layer reflects dissolved oxygen and nutrient concentrations of upwelled Pacific Ocean water modulated by mixing with biologically active surface outflow in the Strait of Juan de Fuca prior to entering Puget Sound over the Admiralty Inlet. The effect of reflux mixing at the Admiralty Inlet sill resulting in lower nutrient and higher dissolved oxygen levels in bottom waters of Puget Sound than the incoming upwelled Pacific Ocean water is reproduced. Finally, by late winter, with the reduction in algal activity, water column constituents of interest, were renewed and the system appeared to reset with cooler temperature, higher nutrient, and higher dissolved oxygen waters from the Pacific Ocean.« less

Effect of mineral nutrients on cell growth and self-flocculation of Tolypothrix tenuis for the production of a biofertilizer.

PubMed

Silva, P G; Silva, H J

2007-02-01

The influence of mineral nutrients on the growth and self-flocculation of Tolypothrix tenuis was studied. The identification of possible limiting nutrients in the culture medium was performed by the biomass elemental composition approach. A factorial experimental design was used in order to estimate the contribution of macronutrients and micronutrients, as well as their interactions. Iron was identified to be limiting in the culture medium. The micronutrients influenced mainly cellular growth without effects on self-flocculation. Conversely, the self-flocculation capacity of the biomass increased at higher concentrations of macronutrients. The optimization of mineral nutrition of T. tenuis allowed a 73% increase in the final biomass level and 3.5 times higher flocculation rates.

Effects of soil characteristics on grape juice nutrient concentrations and other grape quality parameters in Shiraz

NASA Astrophysics Data System (ADS)

Concepción Ramos, Maria; Romero, Maria Paz

2017-04-01

This study investigated the response of grapes to soil properties in the variety Shiraz (SH) cultivated in the Costers de Segre Designation of Origin (NE, Spain). The research was carried out in two areas with differences in vigor, which was examined using the Normalized Difference Vegetation Index (NDVI). Soil properties such as organic matter content, pH, electrical conductivity and nutrients (N, P, K, Ca, Mg, Cu, Zn and Mn) were analysed in the two areas. Soil analyses were limited to the upper 40 cm. Soil N-NO3 was measured in 2M KCl extracts. Assimilable phosphorus was analysed by extraction with 0.5 M NaHCO3 at pH 8.5 using the Olsen method. The available K, Ca and Mg were evaluated in hemaaxinecobalt trichloride extracts and the available fraction of Cu, Zn, Mn and Fe in DTPA- trietanolamine extracts, by spectroscopy atomic emission/absorption. Berry grapes were collected at maturity. Nutrients in grape juice (K, Ca, Mg Cu, Zn, Mn and Fe) were determined after a microwave hydrogen peroxide digestion in a closed vessel microwave digestion system and measured by spectroscopy. Other grape properties that determine grape quality such as pH, berry weight and sugar content were analysed using the methods proposed by the OIV. Differences in soil properties were observed between plots, which determined the differences in vigour. The vines with lower vigour were grown in the soils with higher pH, electrical conductivity and silt content, which had in addition higher Ca, Mg and K available levels as well as higher levels of Fe and Mn than the soil in which vines had higher vigour. However, the available fraction of Cu and Zn was smaller. Similar differences in nutrient concentration in the berry were observed for all nutrients except for Cu. Grape juice pH and total soluble solids (°Brix) were higher in the most vigorous vines. However, the differences in berry weight and total acidity at ripening were not significant. Keywords: acidity; berry weight; nutrients; pH; soil characteristics, sugar content.

Nutrient intake and use of dietary supplements among US adults with disabilities.

PubMed

An, Ruopeng; Chiu, Chung-Yi; Andrade, Flavia

2015-04-01

Physical, mental, social, and financial hurdles in adults with disabilities may limit their access to adequate nutrition. To examine the impact of dietary supplement use on daily total nutrient intake levels among US adults 20 years and older with disabilities. Study sample came from 2007-2008 and 2009-2010 waves of the National Health and Nutrition Examination Survey, a nationally representative repeated cross-sectional survey. Disability was classified into 5 categories using standardized indices. Nutrient intakes from foods and dietary supplements were calculated from 2 nonconsecutive 24-hour dietary recalls. Two-sample proportion tests and multiple logistic regressions were used to examine the adherence rates to the recommended daily nutrient intake levels between dietary supplement users and nonusers in each disability category. The association between sociodemographic characteristics and dietary supplement use was assessed using multiple logistic regressions, accounting for complex survey design. A substantial proportion of the US adult population with disabilities failed to meet dietary guidelines, with insufficient intakes of multiple nutrients. Over half of the US adults with disabilities used dietary supplements. Dietary supplement use was associated with higher adherence rates for vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E, calcium, copper, iron, magnesium, and zinc intake among adults with disabilities. Women, non-Hispanic Whites, older age, higher education, and higher household income were found to predict dietary supplement use. Proper use of dietary supplements under the guidance of health care providers may improve the nutritional status among adults with disabilities. Copyright © 2015 Elsevier Inc. All rights reserved.

Bacteria and Nutrients in the Obhur Recreational Sharm, Jeddah, Saudi Arabia

NASA Astrophysics Data System (ADS)

Turki, Adnan; Mudarris, Mohammed

2013-04-01

Environmental pollution that render waters along the recreational shore unsatisfactory for use by the general public has become a global health problem. This study was carried out to examine the marine waters in sampling stations located at Sharm Obhur (North of Jeddah). These parameters included: total coliform (TC), l fecal coliform (FC) and nutrients (NO2-N, NO3-N, NH4-N and PO4-P). A comparison of the mean values of nutrients in Sharm Obhur with those of other locations in the Red Sea suggests that the mean levels of nutrients were similar to those of unpolluted areas. TC and FC counts were higher at the north sampling stations than the south ones, and with little variations between their numbers. FC was not recovered at stations to the south. The study shows that TC and FC counts at all sampling stations similar to the levels reported for normal unpolluted sea water. Keywords: Pollution, Nutrients, Coliforms, Sharm Obhur, Red Sea.

Nitrate losses, nutrients and heavy metal accumulation from substrates assembled for urban soils reconstruction.

PubMed

Civeira, G; Lavado, R S

2008-09-01

Urban soils may suffer mild to severe degradation as a result of physical and chemical alterations. To reconstruct these soils, a new upper horizon must be created, usually through the application of organic matter, one source of which is biosolids. Different soil mixtures were evaluated with regard to loss of nitrates in percolates and the uptake and incorporation of nutrients and heavy metals into plant tissues. The experiment was conducted in trays; treatments were mixtures of biosolids and a coarse material (e.g., sand or pine wood sawdust), combined in different proportions. Randomized trays were seeded with a mix of tall fescue (Festuca arundinacea L.) and perennial ryegrass (Lolium perenne L.). Plant biomass was quantified. Nitrates in percolates were measured, as were nutrients and heavy metals in mixtures and plant tissues. Plants accumulated substantially more N, and biomass was 40% higher, in the treatments with higher levels of biosolids. The same treatments released more nitrogen and resulted in higher percolate nitrate levels. Plants had normal concentrations of all nutrients, except nitrogen, which was low. Heavy metal concentrations were not significantly different among treatments. Based on the analysis of these data, the proportion of biosolids appears to be the most important factor affecting the quality of reconstructed soil and the rate of improvement. The type of coarse material used did not significantly affect the outcome.

Dietary and urinary metabonomic factors possibly accounting for higher blood pressure of black compared with white Americans: results of International Collaborative Study on macro-/micronutrients and blood pressure.

PubMed

Stamler, Jeremiah; Brown, Ian J; Yap, Ivan K S; Chan, Queenie; Wijeyesekera, Anisha; Garcia-Perez, Isabel; Chadeau-Hyam, Marc; Ebbels, Timothy M D; De Iorio, Maria; Posma, Joram; Daviglus, Martha L; Carnethon, Mercedes; Holmes, Elaine; Nicholson, Jeremy K; Elliott, Paul

2013-12-01

Black compared with non-Hispanic white Americans have higher systolic and diastolic blood pressure and rates of prehypertension/hypertension. Reasons for these adverse findings remain obscure. Analyses here focused on relations of foods/nutrients/urinary metabolites and higher black blood pressure for 369 black compared with 1190 non-Hispanic white Americans aged 40 to 59 years from 8 population samples. Multiple linear regression, standardized data from four 24-hour dietary recalls per person, two 24-hour urine collections, and 8 blood pressure measurements were used to quantitate the role of foods, nutrients, and metabolites in higher black blood pressure. Compared with non-Hispanic white Americans, blacks' average systolic/diastolic pressure was higher by 4.7/3.4 mm Hg (men) and 9.0/4.8 mm Hg (women). Control for higher body mass index of black women reduced excess black systolic/diastolic pressure to 6.8/3.8 mm Hg. Lesser intake of vegetables, fruits, grains, vegetable protein, glutamic acid, starch, fiber, minerals, and potassium, and higher intake of processed meats, pork, eggs, and sugar-sweetened beverages, along with higher cholesterol and higher Na/K ratio, related to in higher black blood pressure. Control for 11 nutrient and 10 non-nutrient correlates reduced higher black systolic/diastolic pressure to 2.3/2.3 mm Hg (52% and 33% reduction in men) and to 5.3/2.8 mm Hg (21% and 27% reduction in women). Control for foods/urinary metabolites had little further influence on higher black blood pressure. Less favorable multiple nutrient intake by blacks than non-Hispanic white Americans accounted, at least in part, for higher black blood pressure. Improved dietary patterns can contribute to prevention/control of more adverse black blood pressure levels.

Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

USDA-ARS?s Scientific Manuscript database

Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

Nutrient availability and phytoplankton nutrient limitation across a gradient of atmospheric nitrogen deposition

USGS Publications Warehouse

Elser, J.J.; Kyle, M.; Steuer, L.; Nydick, K.R.; Baron, Jill S.

2009-01-01

Atmospheric nitrogen (N) deposition to lakes and watersheds has been increasing steadily due to various anthropogenic activities. Because such anthropogenic N is widely distributed, even lakes relatively removed from direct human disturbance are potentially impacted. However, the effects of increased atmospheric N deposition on lakes are not well documented, We examined phytoplankton biomass, the absolute and relative abundance of limiting nutrients (N and phosphorus [P]), and phytoplankton nutrient limitation in alpine lakes of the Rocky Mountains of Colorado (USA) receiving elevated (>6 kg N??ha-1??yr-1) or low (<2 kg N??ha-1??yr-1) levels of atmospheric N deposition. Highdeposition lakes had higher NO3-N and total N concentrations and higher total N : total P ratios. Concentrations of chlorophyll and seston carbon (C) were 2-2.5 times higher in highdeposition relative to low-deposition lakes, while high-deposition lakes also had higher seston C:N and C:P (but not N:P) ratios. Short-term enrichment bioassays indicated a qualitative shift in the nature of phytoplankton nutrient limitation due to N deposition, as highdeposition lakes had an increased frequency of primary P limitation and a decreased frequency and magnitude of response to N and to combined N and P enrichment. Thus elevated atmospheric N deposition appears to have shifted nutrient supply from a relatively balanced but predominantly N-deficient regime to a more consistently P-limited regime in Colorado alpine lakes. This adds to accumulating evidence that sustained N deposition may have important effects on lake phytoplankton communities and plankton-based food webs by shifting the quantitative and qualitative nature of nutrient limitation. ?? 2009 by the Ecological Society of America.

Nutrients Can Enhance the Abundance and Expression of Alkane Hydroxylase CYP153 Gene in the Rhizosphere of Ryegrass Planted in Hydrocarbon-Polluted Soil

PubMed Central

Arslan, Muhammad; Afzal, Muhammad; Amin, Imran; Iqbal, Samina; Khan, Qaiser M.

2014-01-01

Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination. PMID:25360680

Evolving nutritional strategies in the presence of competition: a geometric agent-based model.

PubMed

Senior, Alistair M; Charleston, Michael A; Lihoreau, Mathieu; Buhl, Jerome; Raubenheimer, David; Simpson, Stephen J

2015-03-01

Access to nutrients is a key factor governing development, reproduction and ultimately fitness. Within social groups, contest-competition can fundamentally affect nutrient access, potentially leading to reproductive asymmetry among individuals. Previously, agent-based models have been combined with the Geometric Framework of nutrition to provide insight into how nutrition and social interactions affect one another. Here, we expand this modelling approach by incorporating evolutionary algorithms to explore how contest-competition over nutrient acquisition might affect the evolution of animal nutritional strategies. Specifically, we model tolerance of nutrient excesses and deficits when ingesting nutritionally imbalanced foods, which we term 'nutritional latitude'; a higher degree of nutritional latitude constitutes a higher tolerance of nutritional excess and deficit. Our results indicate that a transition between two alternative strategies occurs at moderate to high levels of competition. When competition is low, individuals display a low level of nutritional latitude and regularly switch foods in search of an optimum. When food is scarce and contest-competition is intense, high nutritional latitude appears optimal, and individuals continue to consume an imbalanced food for longer periods before attempting to switch to an alternative. However, the relative balance of nutrients within available foods also strongly influences at what levels of competition, if any, transitions between these two strategies occur. Our models imply that competition combined with reproductive skew in social groups can play a role in the evolution of diet breadth. We discuss how the integration of agent-based, nutritional and evolutionary modelling may be applied in future studies to further understand the evolution of nutritional strategies across social and ecological contexts.

Light Increases Energy Transfer Efficiency in a Boreal Stream

PubMed Central

Lesutienė, Jūratė; Gorokhova, Elena; Stankevičienė, Daiva; Bergman, Eva; Greenberg, Larry

2014-01-01

Periphyton communities of a boreal stream were exposed to different light and nutrient levels to estimate energy transfer efficiency from primary to secondary producers using labeling with inorganic 13C. In a one-day field experiment, periphyton grown in fast-flow conditions and dominated by opportunistic green algae were exposed to light levels corresponding to sub-saturating (forest shade) and saturating (open stream section) irradiances, and to N and P nutrient additions. In a two-week laboratory experiment, periphyton grown in low-flow conditions and dominated by slowly growing diatoms were incubated under two sub-saturating light and nutrient enrichment levels as well as grazed and non-grazed conditions. Light had significant positive effect on 13C uptake by periphyton. In the field experiment, P addition had a positive effect on 13C uptake but only at sub-saturating light levels, whereas in the laboratory experiment nutrient additions had no effect on the periphyton biomass, 13C uptake, biovolume and community composition. In the laboratory experiment, the grazer (caddisfly) effect on periphyton biomass specific 13C uptake and nutrient content was much stronger than the effects of light and nutrients. In particular, grazers significantly reduced periphyton biomass and increased biomass specific 13C uptake and C:nutrient ratios. The energy transfer efficiency, estimated as a ratio between 13C uptake by caddisfly and periphyton, was positively affected by light conditions, whereas the nutrient effect was not significant. We suggest that the observed effects on energy transfer were related to the increased diet contribution of highly palatable green algae, stimulated by higher light levels. Also, high heterotrophic microbial activity under low light levels would facilitate energy loss through respiration and decrease overall trophic transfer efficiency. These findings suggest that even a small increase in light intensity could result in community-wide effects on periphyton in boreal streams, with a subsequent increase in energy transfer and system productivity. PMID:25412343

Influence of Acacia trees on soil nutrient levels in arid lands

NASA Astrophysics Data System (ADS)

De Boever, Maarten; Gabriels, Donald; Ouessar, Mohamed; Cornelis, Wim

2014-05-01

The potential of scattered trees as keystone structures in restoring degraded environments is gaining importance. Scattered trees have strong influence on their abiotic environment, mainly causing changes in microclimate, water budget and soil properties. They often function as 'nursing trees', facilitating the recruitment of other plants. Acacia raddiana is such a keystone species which persists on the edge of the Sahara desert. The study was conducted in a forest-steppe ecosystem in central Tunisia where several reforestation campaigns with Acacia took place. To indentify the impact of those trees on soil nutrients, changes in nutrient levels under scattered trees of three age stages were examined for the upper soil layer (0-10 cm) at five microsites with increasing distance from the trunk. In addition, changes in soil nutrient levels with depth underneath and outside the canopy were determined for the 0-30 cm soil layer. Higher concentrations of organic matter (OM) were found along the gradient from underneath to outside the canopy for large trees compared to medium and small trees, especially at microsites close to the trunk. Levels of soluble K, electrical conductivity (EC), available P, OM, total C and N decreased whereas pH and levels of soluble Mg increased with increasing distance from tree. Levels of soluble Ca and Na remained unchanged along the gradient. At the microsite closest to the trunk a significant decrease in levels of soluble K, EC, OM, available P, total C and N, while a significant increase in pH was found with increasing depth. The concentration of other nutrients remained unchanged or declined not differently underneath compared to outside the canopy with increasing depth. Differences in nutrient levels were largely driven by greater inputs of organic matter under trees. Hence, Acacia trees can affect the productivity and reproduction of understory species with the latter in term an important source of organic matter. This positive feedback mechanism is of crucial importance for soil nutrient conservation and the restoration of degraded arid environments.

Development and validation of an individual dietary index based on the British Food Standard Agency nutrient profiling system in a French context.

PubMed

Julia, Chantal; Touvier, Mathilde; Méjean, Caroline; Ducrot, Pauline; Péneau, Sandrine; Hercberg, Serge; Kesse-Guyot, Emmanuelle

2014-12-01

Nutrient profiling systems could be useful public health tools as a basis for front-of-package nutrition labeling, advertising regulations, or food taxes. However, their ability beyond characterization of foods to adequately characterize individual diets necessitates further investigation. The objectives of this study were 1) to calculate a score at the individual level based on the British Food Standard Agency (FSA) food-level nutrient profiling system of each food consumed, and 2) to evaluate the validity of the resulting diet-quality score against food group consumption, nutrient intake, and sociodemographic and lifestyle variables. A representative sample of the French population was selected from the NutriNet-Santé Study (n = 4225). Dietary data were collected through repeated 24-h dietary records. Sociodemographic and lifestyle data were self-reported. All foods consumed were characterized by their FSA nutrient profile, and the energy intake from each food consumed was used to compute FSA-derived aggregated scores at the individual level. A score of adherence to French nutritional recommendations [Programme National Nutrition Santé guideline score (PNNS-GS)] was computed as a comparison diet-quality score. Associations between food consumption, nutritional indicators, lifestyle and sociodemographic variables, and quartiles of aggregated scores were investigated using ANOVAs and linear regression models. Participants with more favorable scores consumed higher amounts of fruits [difference Δ = 156 g/d between quartile 1 (less favorable) and quartile 4 (most favorable), P < 0.001], vegetables (Δ = 85 g/d, P < 0.001), and fish, and lower amounts of snack foods (Δ = -72 g/d, P < 0.001 for sugary snacks); they also had higher vitamin and mineral intakes and lower intakes of saturated fat. Participants with more favorable scores also had a higher adherence to nutritional recommendations measured with the PNNS-GS (Δ = 2.13 points, P < 0.001). Women, older subjects, and higher-income subjects were more likely to have more favorable scores. Our results show adequate validity of the FSA nutrient profiling system to characterize individual diets in a French context. The NutriNet-Santé Study was registered in the European Clinical Trials Database (EudraCT) as 2013-000929-31. © 2014 American Society for Nutrition.

Effects of nutrient enrichment derived from fish farming activities on macroinvertebrate assemblages in a subtropical region of Hong Kong.

PubMed

Gao, Qin-Feng; Cheung, Kwok-Leung; Cheung, Siu-Gin; Shin, Paul K S

2005-01-01

To study the correlation between nutrient enrichment derived from fish farming activities and changes in macrobenthic assemblages, a one-year field study was conducted in Kau Sai Bay marine fish culture zone of Hong Kong. Bimonthly sediment samples were collected at six stations: two at the fish cages, two near the boundary of the fish culture area, and two reference sites further away from the culture area. Sediment physico-chemical characteristics in terms of silt/clay fraction, moisture content, total organic carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorus (TP) were analyzed. The macrobenthos (>0.5 mm) present in the sediment were sorted, identified and enumerated. On average, TOC, TKN and TP levels at the fish cage stations were 82.8%, 128.5% and 1315.7% higher than those at the reference stations, respectively. As a result, the N:P molar ratio was greatly reduced from 8.75 at the reference stations to 1.83 at the fish cage stations. Univariate and multivariate analyses revealed that diversity of macrofauna was significantly reduced and community structure differed at the fish cage stations relative to the reference sites. The intermediary stations near the fish culture area showed a transitional state of disturbance. Faunal diversity was negatively correlated with nutrient level, reflecting the adverse impacts of nutrient enrichment derived from fish farming activities on the benthic assemblages. Whilst in subtropical Asia-Pacific trash fish is the major feed for fish culture resulting in a higher nutrient loading and nutrient ratio accumulated in the sediment beneath the fish rafts, the effects of nutrient enrichment on macrobenthic assemblages are comparable to that in temperate waters owing to relatively high sediment metabolism rate and smaller fish culture scale in Hong Kong.

Erythroneura lawsoni abundance and feeding injury levels are influenced by foliar nutrient status in intensively managed American sycamore.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coyle, David, Robert: Aubrey, Doug, Patric; Bentz, Jo-Ann

2010-01-01

Abstract 1 Abundance and feeding injury of the leafhopper Erythroneura lawsoni Robinson was measured in an intensively-managed American sycamore Platanus occidentalis L. plantation. Trees were planted in spring 2000 in a randomized complete block design, and received one of three annual treatments: (i) fertilization (120 kg N/ha/year); (ii) irrigation (3.0 cm/week); (iii) fertilization + irrigation; or (iv) control (no treatment). 2 Foliar nutrient concentrations were significantly influenced by the treatments because only sulphur and manganese levels were not statistically greater in trees receiving fertilization. 3 Over 116 000 E. lawsoni were captured on sticky traps during the study. Leafhopper abundancemore » was highest on nonfertilized trees for the majority of the season, and was positively correlated with foliar nutrient concentrations. Significant temporal variation in E. lawsoni abundance occurred, suggesting five discrete generations in South Carolina. 4 Significant temporal variation occurred in E. lawsoni foliar injury levels, with the highest injury ratings occurring in late June and August. Foliar injury was negatively correlated with foliar nutrient content, and higher levels of injury occurred more frequently on nonfertilized trees. 5 The results obtained in the present study indicated that increased E. lawsoni abundance occurred on trees that did not receive fertilization. Nonfertilized trees experienced greater foliar injury, suggesting that lower foliar nutrient status may have led to increased levels of compensatory feeding.« less

Impact of organic carbon and nutrients mobilized during chemical oxidation on subsequent bioremediation of a diesel-contaminated soil.

PubMed

Sutton, Nora B; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-02-01

Remediation with in situ chemical oxidation (ISCO) impacts soil organic matter (SOM) and the microbial community, with deleterious effects on the latter being a major hurdle to coupling ISCO with in situ bioremediation (ISB). We investigate treatment of a diesel-contaminated soil with Fenton's reagent and modified Fenton's reagent coupled with a subsequent bioremediation phase of 187d, both with and without nutrient amendment. Chemical oxidation mobilized SOM into the liquid phase, producing dissolved organic carbon (DOC) concentrations 8-16 times higher than the untreated field sample. Higher aqueous concentrations of nitrogen and phosphorous species were also observed following oxidation; NH4(+) increased 14-172 times. During the bioremediation phase, dissolved carbon and nutrient species were utilized for microbial growth-yielding DOC concentrations similar to field sample levels within 56d of incubation. In the absence of nutrient amendment, the highest microbial respiration rates were correlated with higher availability of nitrogen and phosphorus species mobilized by oxidation. Significant diesel degradation was only observed following nutrient amendment, implying that nutrients mobilized by chemical oxidation can increase microbial activity but are insufficient for bioremediation. While all bioremediation occurred in the first 28d of incubation in the biotic control microcosm with nutrient amendment, biodegradation continued throughout 187d of incubation following chemical oxidation, suggesting that chemical treatment also affects the desorption of organic contaminants from SOM. Overall, results indicate that biodegradation of DOC, as an alternative substrate to diesel, and biological utilization of mobilized nutrients have implications for the success of coupled ISCO and ISB treatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nutrient profiling can help identify foods of good nutritional quality for their price: a validation study with linear programming.

PubMed

Maillot, Matthieu; Ferguson, Elaine L; Drewnowski, Adam; Darmon, Nicole

2008-06-01

Nutrient profiling ranks foods based on their nutrient content. They may help identify foods with a good nutritional quality for their price. This hypothesis was tested using diet modeling with linear programming. Analyses were undertaken using food intake data from the nationally representative French INCA (enquête Individuelle et Nationale sur les Consommations Alimentaires) survey and its associated food composition and price database. For each food, a nutrient profile score was defined as the ratio between the previously published nutrient density score (NDS) and the limited nutrient score (LIM); a nutritional quality for price indicator was developed and calculated from the relationship between its NDS:LIM and energy cost (in euro/100 kcal). We developed linear programming models to design diets that fulfilled increasing levels of nutritional constraints at a minimal cost. The median NDS:LIM values of foods selected in modeled diets increased as the levels of nutritional constraints increased (P = 0.005). In addition, the proportion of foods with a good nutritional quality for price indicator was higher (P < 0.0001) among foods selected (81%) than among foods not selected (39%) in modeled diets. This agreement between the linear programming and the nutrient profiling approaches indicates that nutrient profiling can help identify foods of good nutritional quality for their price. Linear programming is a useful tool for testing nutrient profiling systems and validating the concept of nutrient profiling.

Growth, biomass allocation and nutrient use efficiency in Cladium jamaicense and Typha domingensis as affected by phosphorus and oxygen availability

USGS Publications Warehouse

Lorenzen, B.; Brix, H.; Mendelssohn, I.A.; McKee, K.L.; Miao, S.L.

2001-01-01

The effects of phosphorus (P) and oxygen availability on growth, biomass allocation and nutrient use efficiency in Cladium jamaicense Crantz and Typha domingensis Pers. were studied in a growth facility equipped with steady-state hydroponic rhizotrons. The treatments included four P concentrations (10, 40, 80 and 500 ??g I-1) and two oxygen concentration (8.0 and <0.5 mg O2 I-1) in the culture solutions. In Cladium, no clear relationship was found between P availability and growth rate (19-37 mg g-1 d-1), the above to below ground biomass ratio (A/B) (mean = 4.6), or nitrogen use efficiency (NUE) (mean = 72 g dry weight g-1 N). However, the ratio between root supported tissue (leaves, rhizomes and ramets) and root biomass (S/R) (5.6-8) increased with P availability. In contrast, the growth rate (48-89 mg g-1 d-1) and the biomass ratios A/B (2.4-6.1) and S/R (5.4-10.3) of Typha increased with P availability, while NUE (71-30 g dry weight g-1 N) decreased. The proportion of root laterals was similar in the two species, but Typha had thinner root laterals (diameter = 186 ??m) than Cladium (diameter = 438 ??m) indicating a larger root surface area in Typha. The two species had a similar P use efficiency (PUE) at 10 ??g PI-1 (mean = 1134 g dry weight g-1 P) and at 40 and 80 ??g PI-1 (mean = 482 dry weight g-1 P) but the N/P ratio indicated imbalances in nutrient uptake at a higher P concentration (40 ??g PI-1) in Typha than in Cladium (10 ??g PI-1). The two species had similar root specific P accumulation rate at the two lowest P levels, whereas Typha had 3-13-fold higher P uptake rates at the two highest P levels, indicating a higher nutrient uptake capacity in Typha. The experimental oxygen concentration in the rhizosphere had only limited effect on the growth of the two species and had little effect on biomass partitioning and nutrient use efficiency. The aerenchyma in these species was probably sufficient to maintain adequate root oxygenation under partially oxygen depleted conditions. Cladium had characteristics typical for plants from nutrient poor habitats, which included slow growth rate, low capacity for P uptake and relatively inflexible biomass partitioning in response to increased P availability. In contrast, Typha demonstrated a high degree of flexibility in growth, biomass partitioning, and nutrient accumulation to P availability, similar to species from nutrient rich habitats. Although the N/P ratio indicated that Typha was more nutrient stressed at the low P levels, Typha had a higher capacity for P uptake and was more competitive than Cladium at the applied P concentrations. ?? 2001 Elsevier Science B.V.

Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

PubMed

Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

2017-01-01

Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15-17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent cultivation in the DeepFlow negatively compared to substrate-based propagation. Water-based propagation resulted in frequent transient discolorations after transplanting in all cultivation systems, indicating a factor, other than irrigation supply of water, nutrients, and oxygen, influencing plant uptake. Plant uptake rates for water, nutrients, and oxygen are offered as a more fundamental way to compare and improve growing systems.

Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems

PubMed Central

Blok, Chris; Jackson, Brian E.; Guo, Xianfeng; de Visser, Pieter H. B.; Marcelis, Leo F. M.

2017-01-01

Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15–17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent cultivation in the DeepFlow negatively compared to substrate-based propagation. Water-based propagation resulted in frequent transient discolorations after transplanting in all cultivation systems, indicating a factor, other than irrigation supply of water, nutrients, and oxygen, influencing plant uptake. Plant uptake rates for water, nutrients, and oxygen are offered as a more fundamental way to compare and improve growing systems. PMID:28443129

Comparing intake estimations based on food composition data with chemical analysis in Malian women.

PubMed

Koréissi-Dembélé, Yara; Doets, Esmee L; Fanou-Fogny, Nadia; Hulshof, Paul Jm; Moretti, Diego; Brouwer, Inge D

2017-06-01

Food composition databases are essential for estimating nutrient intakes in food consumption surveys. The present study aimed to evaluate the Mali food composition database (TACAM) for assessing intakes of energy and selected nutrients at population level. Weighed food records and duplicate portions of all foods consumed during one day were collected. Intakes of energy, protein, fat, available carbohydrates, dietary fibre, Ca, Fe, Zn and vitamin A were assessed by: (i) estimating the nutrient intake from weighed food records based on an adjusted TACAM (a-TACAM); and (ii) chemical analysis of the duplicate portions. Agreement between the two methods was determined using the Wilcoxon signed-rank test and Bland-Altman plots. Bamako, Mali. Apparently healthy non-pregnant, non-lactating women (n 36) aged 15-36 years. Correlation coefficients between estimated and analysed values ranged from 0·38 to 0·61. At population level, mean estimated and analysed nutrient intakes differed significantly for carbohydrates (203·0 v. 243·5 g/d), Fe (9·9 v. 22·8 mg/d) and vitamin A (356 v. 246 µg retinol activity equivalents). At individual level, all estimated and analysed nutrient intakes differed significantly; the differences tended to increase with higher intakes. The a-TACAM is sufficiently acceptable for measuring average intakes of macronutrients, Ca and Zn at population level in low-intake populations, but not for carbohydrate, vitamin A and Fe intakes, and nutrient densities.

Early sugar-sweetened beverage consumption frequency is associated with poor quality of later food and nutrient intake patterns among Japanese young children: the Osaka Maternal and Child Health Study.

PubMed

Okubo, Hitomi; Miyake, Yoshihiro; Sasaki, Satoshi; Tanaka, Keiko; Hirota, Yoshio

2016-06-01

Evidence from Western countries shows that higher consumption of sugar-sweetened beverages (SSBs) is associated with lower quality of young children's diets, but little is known about these relations in non-Western countries with relatively low consumption levels of SSBs. We hypothesized that SSB consumption in infancy would be associated with poor quality of later food and nutrient intake patterns among Japanese young children. The study subjects were 493 Japanese mother-child pairs from a prospective birth cohort study. Dietary data on children were collected from the mothers using self-administered questionnaires when the children were aged 16-24 months and 41-49 months. Multiple linear regression analyses were used to examine the relationships between SSB consumption frequency in infancy and later intake of foods and nutrients. At 16-24 months of age, more than half of the children (56.4%) consumed SSBs less than once a week, whereas 11.6% consumed SSBs at least once daily. More frequent consumption of SSBs in infancy was associated with higher intake of confectionaries and SSBs and lower intake of fruits and vegetables at 41-49 months of age. These associations were still evident after adjustment for maternal SSB consumption and socioeconomic status. At the nutrient level, SSB consumption frequency was positively associated with energy intake and inversely associated with intake of many nutrients, such as protein, dietary fiber, and most of the micronutrients examined. In conclusion, higher consumption frequency of SSBs at an early age is associated with poor quality of overall dietary intake among young Japanese children 1.5-2.5 years later. Copyright © 2016 Elsevier Inc. All rights reserved.

Salmon carcasses increase stream productivity more than inorganic fertilizer pellets: A test on multiple trophic levels in streamside experimental channels

USGS Publications Warehouse

Wipfli, Mark S.; Hudson, John P.; Caouette, John P.; Mitchell, N.L.; Lessard, Joanna L.; Heintz, Ron A.; Chaloner, D.T.

2010-01-01

Inorganic nutrient amendments to streams are viewed as possible restoration strategies for re-establishing nutrients and stream productivity throughout the western coast of North America, where salmon runs and associated marine-derived nutrient subsidies have declined. In a mesocosm experiment, we examined the short-term (6 weeks) comparative effects of artificial nutrient pellets and salmon carcasses, alone (low and high amounts) and in combination, on stream food webs. Response variables included dissolved nutrient concentrations, biofilm ash-free dry mass (AFDM) and chlorophyll-alevels, macroinvertebrate density, growth and body condition of juvenile coho salmon Oncorhynchus kisutch, and whole-body lipid content of invertebrates and juvenile coho salmon. Most of the response variables were significantly influenced by carcass treatment; the only response variable significantly influenced by fertilizer pellet treatment was soluble reactive phosphorus (SRP) concentration. Ammonium-nitrogen concentration was the only response variable affected by both (low and high) levels of carcass treatment; all others showed no significant response to the two carcass treatment levels. Significant treatment × time interactions were observed for all responses except nitrate; for most responses, significant treatment effects were detected at certain time periods and not others. For example, significantly higher SRP concentrations were recorded earlier in the experiment, whereas significant fish responses were observed later. These results provide evidence that inorganic nutrient additions do not have the same ecological effects in streams as do salmon carcasses, potentially because inorganic nutrient additions lack carbon-based biochemicals and macromolecules that are sequestered directly or indirectly by consumers. Salmon carcasses, preferably deposited naturally during spawning migrations, appear to be far superior to inorganic nutrient amendments for sustaining and restoring stream productivity, including fish production, and should be chosen over artificial nutrient additions when feasible and practical.

Marine fisheries declines viewed upside down: human impacts on consumer-driven nutrient recycling.

PubMed

Layman, Craig A; Allgeier, Jacob E; Rosemond, Amy D; Dahlgren, Craig P; Yeager, Lauren A

2011-03-01

We quantified how two human impacts (overfishing and habitat fragmentation) in nearshore marine ecosystems may affect ecosystem function by altering the role of fish as nutrient vectors. We empirically quantified size-specific excretion rates of one of the most abundant fishes (gray snapper, Lutjanus griseus) in The Bahamas and combined these with surveys of fish abundance to estimate population-level excretion rates. The study was conducted across gradients of two human disturbances: overfishing and ecosystem fragmentation (estuaries bisected by roads), to evaluate how each could result in reduced population-level nutrient cycling by consumers. Mean estimated N and P excretion rates for gray snapper populations were on average 456% and 541% higher, respectively, in unfished sites. Ecosystem fragmentation resulted in significant reductions of recycling rates by snapper, with degree of creek fragmentation explaining 86% and 72% of the variance in estimated excretion for dissolved N and P, respectively. Additionally, we used nutrient limitation assays and primary producer nutrient content to provide a simple example of how marine fishery declines may affect primary production. This study provides an initial step toward integrating marine fishery declines and consumer-driven nutrient recycling to more fully understand the implications of human impacts in marine ecosystems.

Finding clean water habitats in urban landscapes: professional researcher vs citizen science approaches.

PubMed

McGoff, Elaine; Dunn, Francesca; Cachazo, Luis Moliner; Williams, Penny; Biggs, Jeremy; Nicolet, Pascale; Ewald, Naomi C

2017-03-01

This study investigated patterns of nutrient pollution in waterbody types across Greater London. Nitrate and phosphate data were collected by both citizen scientists and professional ecologists and their results were compared. The professional survey comprised 495 randomly selected pond, lake, river, stream and ditch sites. Citizen science survey sites were self-selected and comprised 76 ponds, lakes, rivers and streams. At each site, nutrient concentrations were assessed using field chemistry kits to measure nitrate-N and phosphate-P. The professional and the citizen science datasets both showed that standing waterbodies had significantly lower average nutrient concentrations than running waters. In the professional datasets 46% of ponds and lakes had nutrient levels below the threshold at which biological impairment is likely, whereas only 3% of running waters were unimpaired by nutrients. The citizen science dataset showed the same broad pattern, but there was a trend towards selection of higher quality waterbodies with 77% standing waters and 14% of rivers and streams unimpaired. Waterbody nutrient levels in the professional dataset were broadly correlated with landuse intensity. Rivers and streams had a significantly higher proportion of urban and suburban land cover than other waterbody types. Ponds had higher percentage of semi-natural vegetation within their much smaller catchments. Relationships with land cover and water quality were less apparent in the citizen-collected dataset probably because the areas visited by citizens were less representative of the landscape as whole. The results suggest that standing waterbodies, especially ponds, may represent an important clean water resource within urban areas. Small waterbodies, including ponds, small lakes<50ha and ditches, are rarely part of the statutory water quality monitoring programmes and are frequently overlooked. Citizen scientist data have the potential to partly fill this gap if they are co-ordinated to reduce bias in the type and location of the waterbodies selected. Copyright © 2016 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eltahir, F.H.

Nutrient solutions of 25 ppm Mo caused a marked growth reduction of apple seedlings, with the roots being the most sensitive indicators of toxicity symptoms. The toxicity symptoms could be alleviated with the addition of 50 ppm of sulfur to the nutrient solution. Several experiments proved that Mo could be readily absorbed through the leaves and then translocated to other organs and tissues of the plants. However, during the time period of these studies it was not possible to induce toxicity symptoms in apples by foliar applications of Mo. Apple seedlings can absorb and accumulate relatively large amounts of Momore » from nutrient solutions. The highest levels were found in the roots, followed by the leaves and then stems. When applied to bearing trees, a higher concentration of Mo was found in skin of the fruit than in the flesh. In the growth chamber, nitrate-N was highest in all tissues in the 0 ppm Mo nutrient solution and then decreased as the Mo level was increased. The reverse relationship was present with the ascorbic acid content of the leaves, increasing as the level of Mo increased. There was also a reduction of leaf chlorophyll at both the 0 ppm and 25 ppm Mo in the nutrient solutions. When the Mo content of the nutrient solutions was increased from 0 ppm through 25 ppm, there was a significant effect on the leaf levels of P, Mg and Zn, and on P, Ca, Mg, Mn, Fe, B and Zn in the roots. The greatest effect of 25 ppm Mo in the nutrient solutions. When the Mo content of the nutrient solutions was increased from 0 ppm through 25 ppm, there was a significant effect on the leaf levels of P, Mg and Zn, and on P, Ca, Mg, Mn, Fe, B and Zn in the roots. The greatest effect of 25 ppm Mo in the nurient solutions were on P and Zn in the leaves, and on P, Zn, Ca and Fe in the roots.« less

Light Is More Important Than Nutrient Ratios of Fertilization for Cymodocea nodosa Seedling Development.

PubMed

Alexandre, Ana; Silva, João; Santos, Rui

2018-01-01

Restoration of seagrass beds through seedlings is an alternative to the transplantation of adult plants that reduces the impact over donor areas and increases the genetic variability of restored meadows. To improve the use of Cymodocea nodosa seedlings, obtained from seeds germinated in vitro , in restoration programs, we investigated the ammonium and phosphate uptake rates of seedlings, and the synergistic effects of light levels (20 and 200 μmol quanta m -2 s -1 ) and different nitrogen to phosphorus molar ratios (40 μM N:10 μM P, 25 μM N:25 μM P, and 10 μM N:40 μM P) on the photosynthetic activity and growth of seedlings. The nutrient content of seedlings was also compared to the seed nutrient reserves to assess the relative importance of external nutrient uptake for seedling development. Eighty two percent of the seeds germinated after 48 days at a mean rate of 1.5 seeds per day. All seedlings under all treatments survived and grew during the 4 weeks of the experiment. Seedlings of C. nodosa acquired ammonium and phosphate from the incubation media while still attached to the seed, at rates of about twice of adult plants. The relevance of external nutrient uptake was further highlighted by the observation that seedlings' tissues were richer in nitrogen and phosphorus than non-germinated seeds. The uptake of ammonium followed saturation kinetics with a half saturation constant of 32 μM whereas the uptake of phosphate increased linearly with nutrient concentration within the range tested (5 - 100 μM). Light was more important than the nutrient ratio of fertilization for the successful development of the young seedlings. The seedlings' photosynthetic and growth rates were about 20% higher in the high light treatment, whereas different nitrogen to phosphorus ratios did not significantly affect growth. The photosynthetic responses of the seedlings to changes in the light level and their capacity to use external nutrient sources showed that seedlings of C. nodosa have the ability to rapidly acclimate to the surrounding light and nutrient environment while still attached to the seeds. C. nodosa seedlings experiencing fertilization under low light levels showed slightly enhanced growth if nourished with a balanced formulation, whereas a slight increase in growth was also observed with unbalanced formulations under a higher light level. Our results highlight the importance of high light availability at the seedling restoration sites.

Assessing the impacts of salinity and nutrient stress to Ruppia ...

EPA Pesticide Factsheets

Healthy seagrass beds were once found throughout the shallow areas of Narragansett Bay, R.I. but have disappeared due to infilling, pollution and disease. In Greenwich Bay, a highly developed embayment within Narragansett Bay, Ruppia maritima has colonized an area on the northern shore historically dominated by Zostera marina. Ruppia is extremely salinity tolerant, and may also be more nutrient tolerant than Zostera. To test this hypothesis 6-week microcosm experiments were conducted in the summers of 2014 and 2015. Microcosms were renewed daily to simulate tidal flushing and the water column was dosed with a 15N tracer for the first week of the experiments. In the 2014 microcosm experiment two salinity (20, 30 ppt) and four nutrient (0, 5, 10, 30 µM inorganic N) levels were used to test the species’ relative tolerance. This experiment yielded structurally significant results for Ruppia but no significant differences were detected for Zostera. In 2015 this experiment was performed for a second time with lower salinity (5, 30 ppt) and higher nutrients (0, 30, 100, 300, 1000 µM inorganic N) in order to determine Zostera’s tolerance to nutrient and salinity stress and confirm the previously observed Ruppia results. Both species had significant structural responses to the nutrient and salinity variables. Isotopic analysis run on above-ground tissue indicated that with increasing nutrient levels δ15N in the seagrass shoots increased, suggesting that nutrients

Colonic luminal microbiota and bacterial metabolite composition in pregnant Huanjiang mini-pigs: effects of food composition at different times of pregnancy

PubMed Central

Kong, Xiang-feng; Ji, Yu-jiao; Li, Hua-wei; Zhu, Qian; Blachier, F.; Geng, Mei-mei; Chen, Wen; Yin, Yu-long

2016-01-01

The gut harbours diverse and complex microbiota, which influence body health including nutrient metabolism, immune development, and protection from pathogens. Pregnancy is associated with immune and metabolic changes that might be related to microbiota compositional dynamics. We therefore investigated the colonic luminal bacteria community in Huanjiang mini-pigs fed diets with different nutrient levels from the first to third trimester of pregnancy. The concentrations of intestinal metabolites including short-chain fat acids, NH3-N, indole, skatole, and bioamines were also determined. We found that the colonic bacteria species richness estimators (Chao1 and ACE) decreased with increased gestational age. The dominant phyla identified were Firmicutes and Bacteroidetes; the dominant genera were Lactobacillus, Treponema, Ruminococcus, Clostridium, and Prevotella. In addition, microbiota displayed spatial and temporal heterogeneity in composition, diversity, and species abundance in different colonic segments from the first to third trimester of pregnancy. Furthermore, the bacterial metabolites also changed according to the diet used and the pregnancy stage. These findings suggest that colonic bacteria richness decreased as gestational age increased, and that the higher nutrient level diet increased the production of metabolites related to nitrogen metabolism. However, although the higher nutrient diet was associated with pregnancy syndrome, causal links remain to be determined. PMID:27917879

Effects of forest fire on soil nutrients in Turkish pine (Pinus brutia, Ten) ecosystems.

PubMed

Yildiz, Oktay; Esen, Derya; Sarginci, Murat; Toprak, Bulent

2010-01-01

Fire is a long-standing and poorly understood component of the Mediterranean forestlands in Turkey. Fire can alter plant composition, destroy biomass, alter soil physical and chemical properties and reduce soil nutrient pools. However fire can also promote productivity of certain ecosystems by mineralizing soil nutrients and promoting fast growing nitrogen fixing plant species. Fire effects on soils and ecosystems in Turkey and Mediterranean regions are not well understood. This study uses a retrospective space-for-time substitution to study soil macro-nutrient changes on sites which were burned at different times during the last 8 years. The study sites are in the Fethiye Forest Management Directorate in the western Mediterranean Sea region of Turkey. Our samples show 40% less Soil C, and cation exchange capacity (CEC) at 0-20 cm soil depth two weeks after the fire. Soil C and CEC appear to recover to pre-fire level in one year. Concentrations of Mg were significantly lower on new-burn sites, but returned to pre-fire levels in one year. Total soil N concentrations one and two years after fire were 90% higher than other sites, and total P was 9 times higher on new-burn site than averages from other sites. Some implications of these results for forest managers are discussed.

Evolving Nutritional Strategies in the Presence of Competition: A Geometric Agent-Based Model

PubMed Central

Senior, Alistair M.; Charleston, Michael A.; Lihoreau, Mathieu; Buhl, Jerome; Raubenheimer, David; Simpson, Stephen J.

2015-01-01

Access to nutrients is a key factor governing development, reproduction and ultimately fitness. Within social groups, contest-competition can fundamentally affect nutrient access, potentially leading to reproductive asymmetry among individuals. Previously, agent-based models have been combined with the Geometric Framework of nutrition to provide insight into how nutrition and social interactions affect one another. Here, we expand this modelling approach by incorporating evolutionary algorithms to explore how contest-competition over nutrient acquisition might affect the evolution of animal nutritional strategies. Specifically, we model tolerance of nutrient excesses and deficits when ingesting nutritionally imbalanced foods, which we term ‘nutritional latitude’; a higher degree of nutritional latitude constitutes a higher tolerance of nutritional excess and deficit. Our results indicate that a transition between two alternative strategies occurs at moderate to high levels of competition. When competition is low, individuals display a low level of nutritional latitude and regularly switch foods in search of an optimum. When food is scarce and contest-competition is intense, high nutritional latitude appears optimal, and individuals continue to consume an imbalanced food for longer periods before attempting to switch to an alternative. However, the relative balance of nutrients within available foods also strongly influences at what levels of competition, if any, transitions between these two strategies occur. Our models imply that competition combined with reproductive skew in social groups can play a role in the evolution of diet breadth. We discuss how the integration of agent-based, nutritional and evolutionary modelling may be applied in future studies to further understand the evolution of nutritional strategies across social and ecological contexts. PMID:25815976

Contribution of Dietary Supplements to Nutritional Adequacy in Various Adult Age Groups.

PubMed

Blumberg, Jeffrey B; Frei, Balz; Fulgoni, Victor L; Weaver, Connie M; Zeisel, Steven H

2017-12-06

Many Americans have inadequate intakes of several nutrients. The Dietary Guidelines for Americans 2015-2020 specifically identified vitamins A, C, D and E, calcium, magnesium, iron, potassium, choline and fiber as "underconsumed nutrients". Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009-2012, assessments were made of age-group differences in the impact of dietary supplements on nutrient intake and inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly ( p < 0.01) higher intakes of 15-16 of 19 nutrients examined in all age groups; and significantly reduced rates of inadequacy for 10/17, 8/17 and 6/17 nutrients examined among individuals age ≥71, 51-70 and 19-50 years, respectively. Compared to the other age groups, older adults (≥71 years) had lower rates of inadequacy for iron and vitamins A, C, D and E, but higher rates for calcium. An increased prevalence of intakes above the Tolerable Upper Intake Level was seen for 8-9 of 13 nutrients, but were mostly less than 5% of the population. In conclusion, dietary supplement use is associated with increased micronutrient intake, decreased inadequacies, and slight increases in prevalence above the UL, with greater benefits seen among older adults.

Synergistic Effects of Human Milk Nutrients in the Support of Infant Recognition Memory: An Observational Study

PubMed Central

Cheatham, Carol L.; Sheppard, Kelly Will

2015-01-01

The aim was to explore the relation of human milk lutein; choline; and docosahexaenoic acid (DHA) with recognition memory abilities of six-month-olds. Milk samples obtained three to four months postpartum were analyzed for fatty acids, lutein, and choline. At six months, participants were invited to an electrophysiology session. Recognition memory was tested with a 70–30 oddball paradigm in a high-density 128-lead event-related potential (ERP) paradigm. Complete data were available for 55 participants. Data were averaged at six groupings (Frontal Right; Frontal Central; Frontal Left; Central; Midline; and Parietal) for latency to peak, peak amplitude, and mean amplitude. Difference scores were calculated as familiar minus novel. Final regression models revealed the lutein X free choline interaction was significant for the difference in latency scores at frontal and central areas (p < 0.05 and p < 0.001; respectively). Higher choline levels with higher lutein levels were related to better recognition memory. The DHA X free choline interaction was also significant for the difference in latency scores at frontal, central, and midline areas (p < 0.01; p < 0.001; p < 0.05 respectively). Higher choline with higher DHA was related to better recognition memory. Interactions between human milk nutrients appear important in predicting infant cognition, and there may be a benefit to specific nutrient combinations. PMID:26540073

Synergistic Effects of Human Milk Nutrients in the Support of Infant Recognition Memory: An Observational Study.

PubMed

Cheatham, Carol L; Sheppard, Kelly Will

2015-11-03

The aim was to explore the relation of human milk lutein; choline; and docosahexaenoic acid (DHA) with recognition memory abilities of six-month-olds. Milk samples obtained three to four months postpartum were analyzed for fatty acids, lutein, and choline. At six months, participants were invited to an electrophysiology session. Recognition memory was tested with a 70-30 oddball paradigm in a high-density 128-lead event-related potential (ERP) paradigm. Complete data were available for 55 participants. Data were averaged at six groupings (Frontal Right; Frontal Central; Frontal Left; Central; Midline; and Parietal) for latency to peak, peak amplitude, and mean amplitude. Difference scores were calculated as familiar minus novel. Final regression models revealed the lutein X free choline interaction was significant for the difference in latency scores at frontal and central areas (p < 0.05 and p < 0.001; respectively). Higher choline levels with higher lutein levels were related to better recognition memory. The DHA X free choline interaction was also significant for the difference in latency scores at frontal, central, and midline areas (p < 0.01; p < 0.001; p < 0.05 respectively). Higher choline with higher DHA was related to better recognition memory. Interactions between human milk nutrients appear important in predicting infant cognition, and there may be a benefit to specific nutrient combinations.

Global implementation of two shared socioeconomic pathways for future sanitation and wastewater flows.

PubMed

van Puijenbroek, P J T M; Bouwman, A F; Beusen, A H W; Lucas, P L

2015-01-01

Households are an important source of nutrient loading to surface water. Sewage systems without or with only primary wastewater treatment are major polluters of surface water. Future emission levels will depend on population growth, urbanisation, increases in income and investments in sanitation, sewage systems and wastewater treatment plants. This study presents the results for two possible shared socioeconomic pathways (SSPs). SSP1 is a scenario that includes improvement of wastewater treatment and SSP3 does not include such improvement, with fewer investments and a higher population growth. The main drivers for the nutrient emission model are population growth, income growth and urbanisation. Under the SSP1 scenario, 5.7 billion people will be connected to a sewage system and for SSP3 this is 5 billion. Nitrogen and phosphorus emissions increase by about 70% under both SSP scenarios, with the largest increase in SSP1. South Asia and Africa have the largest emission increases, in the developed countries decrease the nutrient emissions. The higher emission level poses a risk to ecosystem services.

Hormone, metabolic peptide, and nutrient levels in the earliest phases of rheumatoid arthritis-contribution of free fatty acids to an increased cardiovascular risk during very early disease.

PubMed

Tang, Man Wai; Koopman, Frieda A; Visscher, Jan P M; de Hair, Maria J; Gerlag, Danielle M; Tak, Paul Peter

2017-02-01

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with changes in several hormones and metabolic peptides. Crosstalk between these factors and the immune system may be important for homeostasis during inflammation. Here, we studied the levels of hormones, metabolic peptides, and nutrients in individuals at risk for developing RA (at risk). In total, 18 hormones, metabolic peptides, and nutrients were measured in fasting serum samples from 45 autoantibody-positive individuals at risk, 22 RA patients, and 16 healthy subjects. Triglyceride (TG) levels were also measured in an independent validation cohort of 32 individuals at risk, 20 early arthritis patients, and 20 healthy controls. We found an elevated TG level in individuals at risk and significantly higher TG levels in RA patients compared to healthy controls. These results were confirmed in the validation cohort. Similarly, free fatty acid (FFA) levels showed an increase in individuals at risk and were significantly higher in RA patients compared to healthy controls. In RA patients, FFA levels were positively correlated with disease activity. Pancreatic polypeptide (PP) and norepinephrine levels were highly significantly increased in individuals at risk and RA patients compared to healthy controls. TG and FFA levels are increased in RA patients and positively correlated with disease activity parameters. The results presented here suggest a role for FFAs in the pathogenesis of RA. Furthermore, PP and norepinephrine may be a biomarker that could assist in the identification of individuals at risk.

Food labeling; nutrient content claims, definition of sodium levels for the term "healthy." Final rule.

PubMed

2005-09-29

The Food and Drug Administration (FDA) is amending its regulations concerning the maximum sodium levels permitted for foods that bear the implied nutrient content claim "healthy." The agency is retaining the currently effective, less restrictive, "first-tier" sodium level requirements for all food categories, including individual foods (480 milligrams (mg)) and meals and main dishes (600 mg), and is dropping the "second-tier" (more restrictive) sodium level requirements for all food categories. Based on the comments received about technological barriers to reducing sodium in processed foods and poor sales of products that meet the second-tier sodium level, the agency has determined that requiring the more restrictive sodium levels would likely inhibit the development of new "healthy" food products and risk substantially eliminating existing "healthy" products from the marketplace. After reviewing the comments and evaluating the data from various sources, FDA has become convinced that retaining the higher first-tier sodium level requirements for all food products bearing the term "healthy" will encourage the manufacture of a greater number of products that are consistent with dietary guidelines for a variety of nutrients. The agency has also revised the regulatory text of the "healthy" regulation to clarify the scope and meaning of the regulation and to reformat the nutrient content requirements for "healthy" into a more readable set of tables, consistent with the Presidential Memorandum instructing that regulations be written in plain language.

Effects of temperature, algae biomass and ambient nutrient on the absorption of dissolved nitrogen and phosphate by Rhodophyte Gracilaria asiatica

NASA Astrophysics Data System (ADS)

Du, Rongbin; Liu, Liming; Wang, Aimin; Wang, Yongqiang

2013-03-01

Gracilaria asiatica, being highly efficient in nutrient absorption, is cultivated in sea cucumber ponds to remove nutrients such as nitrogen and phosphate. It was cultured in a laboratory simulating field conditions, and its nutrient absorption was measured to evaluate effects of environmental conditions. Ammonia nitrogen (AN), nitrate nitrogen (NN), total inorganic nitrogen (TIN), and soluble reactive phosphorus (SRP) uptake rate and removal efficiency were determined in a 4×2 factorial design experiment in water temperatures ( T) at 15°C and 25°C, algae biomass (AB) at 0.5 g/L and 1.0 g/L, total inorganic nitrogen (TIN) at 30 μmol/L and 60 μmol/L, and soluble reactive phosphorus (SRP) at 3 and 6 μmol/L. AB and ambient TIN or SRP levels significantly affected uptake rate and removal efficiency of AN, NN, TIN, and SRP ( P< 0.001). G. asiatica in AB of 0.5 g/L showed higher uptake rate and lower removal efficiency relative to that with AB of 1.0 g/L. Nitrogen and phosphorus uptake rate rose with increasing ambient nutrient concentrations; nutrient removal efficiency decreased at higher environmental nutrient concentrations. The algae preferred to absorb AN to NN. Uptake rates of AN, NN, and SRP were significantly affected by temperature ( P < 0.001); uptake rate was higher for the 25°C group than for the 15°C group at the initial experiment stage. Only the removal efficiency of AN and SRP showed a significant difference between the two temperature groups ( P< 0.01). The four factors had significant interactive effects on absorption of N and P, implying that G. asiatica has great bioremedial potential in sea cucumber culture ponds.

Nutrients stimulate leaf breakdown rates and detritivore biomass: Bottom-up effects via heterotrophic pathways

USGS Publications Warehouse

Greenwood, J.L.; Rosemond, A.D.; Wallace, J.B.; Cross, W.F.; Weyers, H.S.

2007-01-01

Most nutrient enrichment studies in aquatic systems have focused on autotrophic food webs in systems where primary producers dominate the resource base. We tested the heterotrophic response to long-term nutrient enrichment in a forested, headwater stream. Our study design consisted of 2 years of pretreatment data in a reference and treatment stream and 2 years of continuous nitrogen (N) + phosphorus addition to the treatment stream. Studies were conducted with two leaf species that differed in initial C:N, Rhododendron maximum (rhododendron) and Acer rubrum (red maple). We determined the effects of nutrient addition on detrital resources (leaf breakdown rates, litter C:N and microbial activity) and tested whether nutrient enrichment affected macroinvertebrate consumers via increased biomass. Leaf breakdown rates were ca. 1.5 and 3?? faster during the first and second years of enrichment, respectively, in the treatment stream for both leaf types. Microbial respiration rates of both leaf types were 3?? higher with enrichment, and macroinvertebrate biomass associated with leaves increased ca. 2-3?? with enrichment. The mass of N in macroinvertebrate biomass relative to leaves tended to increase with enrichment up to 6?? for red maple and up to 44?? for rhododendron leaves. Lower quality (higher C:N) rhododendron leaves exhibited greater changes in leaf nutrient content and macroinvertebrate response to nutrient enrichment than red maple leaves, suggesting a unique response by different leaf species to nutrient enrichment. Nutrient concentrations used in this study were moderate and equivalent to those in streams draining watersheds with altered land use. Thus, our results suggest that similarly moderate levels of enrichment may affect detrital resource quality and subsequently lead to altered energy and nutrient flow in detrital food webs. ?? 2006 Springer-Verlag.

[Effects of sediment dredging on benthos community structure and water quality in Zhushan Bay].

PubMed

Liu, Guo-Feng; Zhang, Zhi-Yong; Liu, Hai-Qin; Zhong, Ji-Cheng; Yan, Shao-Hua; Fan, Cheng-Xin

2010-11-01

We surveyed the changes of macro-benthos community composition and nutrients concentration in water in Zhushan Bay after it had been dredged 6 months, which aimed to remove the polluted surface sediments. The results showed that the main benthos in the dredged and un-dredged sediments were Limodrilus hoffmeisteri, Pelopia and Bellamya aeruginosa; compared to the un-dredged sediments, the bio-diversity of dredged areas became lower. However, its biomass became higher than that in un-dredged areas. Concentration range changes of TN and TP in overlying water was 1.64-4.45 mg/L and 0.133-0.258 mg/L, respectively. The post-dredged sediments were still in a higher state of nutrients for the higher concentration nutrients in overlying water, macro-benthos were the species that lived in a serious polluted water environment. Using Shannon-Weaver, Simpson, and Goodnight benthic index to evaluate the results show that the dredged area is in the moderately polluted level, but un-dredged area is in the middle-heavily polluted level. According to the benthos fauna surveys and water quality monitoring results, the effective of sediment dredging could play its role only the strict control on the external pollution resources have been made and reduces the effects of polluted water on the sediments.

Role of the fish astyanax aeneus (Characidae) as a keystone nutrient recycler in low-nutrient neotropical streams

USGS Publications Warehouse

Small, G.E.; Pringle, C.M.; Pyron, M.; Duff, J.H.

2011-01-01

Nutrient recycling by animals is a potentially important biogeochemical process in both terrestrial and aquatic ecosystems. Stoichiometric traits of individual species may result in some taxa playing disproportionately important roles in the recycling of nutrients relative to their biomass, acting as keystone nutrient recyclers. We examined factors controlling the relative contribution of 12 Neotropical fish species to nutrient recycling in four streams spanning a range of phosphorus (P) levels. In high-P conditions (135 ??g/L soluble reactive phosphorus, SRP), most species fed on P-enriched diets and P excretion rates were high across species. In low-P conditions (3 ??g/L SRP), aquatic food resources were depleted in P, and species with higher body P content showed low rates of P recycling. However, fishes that were subsidized by terrestrial inputs were decoupled from aquatic P availability and therefore excreted P at disproportionately high rates. One of these species, Astyanax aeneus (Characidae), represented 12% of the total population and 18% of the total biomass of the fish assemblage in our focal low-P study stream but had P excretion rates >10-fold higher than other abundant fishes. As a result, we estimated that P excretion by A. aeneus accounted for 90% of the P recycled by this fish assemblage and also supplied ???90% of the stream P demand in this P-limited ecosystem. Nitrogen excretion rates showed little variation among species, and the contribution of a given species to ecosystem N recycling was largely dependent upon the total biomass of that species. Because of the high variability in P excretion rates among fish species, ecosystem-level P recycling could be particularly sensitive to changes in fish community structure in P-limited systems. ?? 2011 by the Ecological Society of America.

Gastropod growth and survival as bioindicators of stress associated with high nutrients in the intertidal of a shallow temperate estuary

NASA Astrophysics Data System (ADS)

Marsden, Islay D.; Baharuddin, Nursalwa

2015-04-01

The effects of multiple stressors on estuarine organisms are not well understood. Using cage experiments we measured the survival and growth of the pulmonate gastropod Amphibola crenata at five locations which differed contaminant levels. Water nutrients came from a nearby sewage treatment works and the sediment contained low levels of trace metals. Over 6 weeks of exposure, sediment surface chlorophyll levels varied amongst locations. The Chl a values were positively correlated with sediment N and P and trace metals As, Cd, Cu, Pb and Zn. Pulmonate survival depended on location, highest mortality was from a site close to the treatment plant and mortality rate of large individuals decreased significantly with distance away from it. For four locations, medium A. crenata had higher survival than small (juveniles) or adults. Growth rates of small individuals exceeded those for medium and large A. crenata. The mean length increment/week for medium gastropods ranged between 0.49 and 1.11 mm and was negatively correlated with the amount of Chl a in the surface sediment, suggesting the negative effects of eutrophication on gastropod growth. Growth rate of the pulmonate was not correlated with nutrient concentration or trace metal concentrations in the sediment. The dry weight condition index (CI) did not correlate with the growth rate, and for medium individuals, was unaffected by any of the environmental variables. The CI of small individuals was negatively affected by increasing water nutrient levels and the CI of large individuals negatively affected by increasing sediment nutrients and trace metal concentrations. The results from this study suggest that gastropod growth and survival could be used as tools to monitor the effects of changing nutrient levels and recovery from eutrophication within temperate estuaries.

Dietary patterns of adolescents in Germany--associations with nutrient intake and other health related lifestyle characteristics.

PubMed

Richter, Almut; Heidemann, Christin; Schulze, Matthias B; Roosen, Jutta; Thiele, Silke; Mensink, Gert B M

2012-03-22

The aim of this study was to identify dietary patterns among a representative sample of German adolescents and their associations with energy and nutrient intake, socioeconomic and lifestyle characteristics, and overweight status. In the analysis, data from the German Health Interview and Examination Survey for Children and Adolescents were used. The survey included a comprehensive dietary history interview conducted among 1272 adolescents aged 12 to 17 years. Dietary patterns were determined with principal component analysis (PCA) based on 48 food groups, for boys and girls separately. Three dietary patterns among boys and two among girls were identified. Among boys, high adherence to the 'western' pattern was associated with higher age, lower socioeconomic status (SES), and lower physical activity level (PA). High adherence to the 'healthy' pattern among boys, but not among girls, was associated with higher SES, and higher PA. Among boys, high adherence to the 'traditional' pattern was associated with higher age. Among girls, high adherence to the 'traditional and western' pattern was associated with lower age, lower SES and more hours watching TV per day. The nutrient density of several vitamins and minerals, particularly of B-vitamins and calcium, increased with increasing scores of the 'healthy' pattern among both sexes. Conversely, with increasing scores of the 'western' pattern among boys, most nutrient densities decreased, particularly of fibre, beta-carotene, vitamin D, biotin and calcium. Among girls with higher scores of the 'traditional and western' pattern, nutrient densities of vitamin A, C, E, K and folate decreased. Among boys, high adherence to the 'traditional' pattern was correlated with higher densities of vitamin B12 and vitamin D and lower densities of fibre, magnesium and iron. No significant associations between dietary patterns and overweight were found. Higher scores for dietary patterns characterized by higher consumption of take away food, meat, confectionary and soft drinks ('western' and 'traditional and western') were found particularly among 16- to 17-years old boys and among adolescents with lower SES. These patterns were also associated with higher energy density, higher percent of energy from unsaturated fatty acids and lower percent of energy from carbohydrates as well as lower nutrient densities of several vitamins and minerals. Therefore, nutritional interventions should try to focus more on adolescents with lower SES and boys in general.

Effects of agricultural subsidies of nutrients and detritus on fish and plankton of shallow-reservoir ecosystems.

PubMed

Pilati, Alberto; Vanni, Michael J; González, María J; Gaulke, Alicia K

2009-06-01

Agricultural activities increase exports of nutrients and sediments to lakes, with multiple potential impacts on recipient ecosystems. Nutrient inputs enhance phytoplankton and upper trophic levels, and sediment inputs can shade phytoplankton, interfere with feeding of consumers, and degrade benthic habitats. Allochthonous sediments are also a potential food source for detritivores, as is sedimenting autochthonous phytodetritus, the production of which is stimulated by nutrient inputs. We examined effects of allochthonous nutrient and sediment subsidies on fish and plankton, with special emphasis on gizzard shad (Dorosoma cepedianum). This widespread and abundant omnivorous fish has many impacts on reservoir ecosystems, including negative effects on water quality via nutrient cycling and on fisheries via competition with sportfish. Gizzard shad are most abundant in agriculturally impacted, eutrophic systems; thus, agricultural subsidies may affect reservoir food webs directly and by enhancing gizzard shad biomass. We simulated agricultural subsidies of nutrients and sediment detritus by manipulating dissolved nutrients and allochthonous detritus in a 2 x 2 factorial design in experimental ponds. Addition of nutrients alone increased primary production and biomass of zooplanktivorous fish (bluegill and young-of-year gizzard shad). Addition of allochthonous sediments alone increased algal sedimentation and decreased seston and sediment C:P ratios. Ponds receiving both nutrients and sediments showed highest levels of phytoplankton and total phosphorus. Adult and juvenile gizzard shad biomass was enhanced equally by nutrient or sediment addition, probably because this apparently P-limited detritivore ingested similar amounts of P in all subsidy treatments. Nutrient excretion rates of gizzard shad were higher in ponds with nutrient additions, where sediments were composed mainly of phytodetritus. Therefore, gizzard shad can magnify the direct effects of nutrient subsidies on phytoplankton production, and these multiple effects must be considered in strategies to manage eutrophication and fisheries in warmwater reservoir lakes where gizzard shad can dominate fish biomass.

Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow

PubMed Central

Ortega-Cisneros, Kelly; Scharler, Ursula M.

2015-01-01

This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N) and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N) was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N) and the tanaid Apseudes digitalis (%N, C:N). These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that estuarine invertebrates concentrated C and N between 10–100 fold from trophic level I (POM) to trophic level II (detritivores/deposit feeders) and thus highlighted their importance not only as links to higher trophic level organisms in the food web, but also as providers of a stoichiometrically homeostatic food source for such consumers. As climate change scenarios for the east coast of South Africa predict increased rainfall as a higher number of rainy days and days with higher rainfall, our results suggest that future changes in rainfall and river inflow will have measurable effects on the nutrient content and stoichiometry of food sources and possibly also in estuarine consumers. PMID:26352433

Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow.

PubMed

Ortega-Cisneros, Kelly; Scharler, Ursula M

2015-01-01

This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N) and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N) was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N) and the tanaid Apseudes digitalis (%N, C:N). These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that estuarine invertebrates concentrated C and N between 10-100 fold from trophic level I (POM) to trophic level II (detritivores/deposit feeders) and thus highlighted their importance not only as links to higher trophic level organisms in the food web, but also as providers of a stoichiometrically homeostatic food source for such consumers. As climate change scenarios for the east coast of South Africa predict increased rainfall as a higher number of rainy days and days with higher rainfall, our results suggest that future changes in rainfall and river inflow will have measurable effects on the nutrient content and stoichiometry of food sources and possibly also in estuarine consumers.

Long-term fertilization, but not warming, shifts rates of ectomycorrhizal nutrient cycling in Arctic tussock tundra.

NASA Astrophysics Data System (ADS)

Dunleavy, H.; Mack, M. C.

2017-12-01

The role of ectomycorrhizae (ECM) in Arctic nutrient cycling may be changing as temperature, nutrient availability, and ECM shrub abundance and size increase. A shift in ECM function has been proposed as a possible mechanism for shrub expansion. While several studies demonstrate a higher abundance of ECM as well as community compositional shifts in response to long-term experimental warming and fertilization, direct measurements of functional responses are missing. To understand the potential role of ECM in soil biogeochemical processes of the changing Arctic, we investigated the functional response of ECM to 30 years of summer warming and increased nutrient availability by measuring potential activities of extracellular enzymes associated with nitrogen (N) and phosphorous (P) acquisition on ECM root tips. We hypothesize ECM enzyme activities will be higher with warmer temperatures. Conversely, fertilization will lower ECM enzyme activities as N and P become less limiting to host plants. Preliminary results strongly support our latter hypothesis, but not the first. Warming decreased hydrolytic P-associated and labile N-associated enzyme activities on individual root tips (pmol/min/mm2 root tip) by 30% and 83%, respectively. However, warming increased ECM abundance and did not alter community-level activities (pmol/min/cm3 soil). Fertilization decreased hydrolytic and oxidative enzymatic activities on individual root tips by 34 to 80% as well as on a community level by 67 to 93%, even though ECM shrubs were almost monodominant. The combined effect of warming and fertilization decreased labile N-associated enzyme activity by 82%, but had little effect on oxidative and other hydrolytic enzyme activities. Although both warming and fertilization decreased root tip activities, reflecting a potential reduction in plant allocation to mycorrhizal nutrient acquisition, only fertilization lowered rates of ECM nutrient cycling. The indirect relationship between ECM abundance and individual root tip activity highlights the importance of measuring ECM function to assess the role of this symbiosis in nutrient cycling.

Effect of multi-nutrient insufficiency on markers of one carbon metabolism in young women: response to a methionine load.

PubMed

Katre, P; Joshi, S; Bhat, D S; Deshmukh, M; Gurav, N; Pandit, S; Lubree, H; Marczewski, S; Bennett, C; Gruca, L; Kalyanaraman, K; Naik, S S; Yajnik, C S; Kalhan, S C

2016-06-01

Multi-nutrient insufficiencies as a consequence of nutritional and economic factors are common in India and other developing countries. We have examined the impact of multi-nutrient insufficiency on markers of one carbon (1C) metabolism in the blood, and response to a methionine load in clinically healthy young women. Young women from Pune, India (n=10) and Cleveland, USA (n=13) were studied. Blood samples were obtained in the basal state and following an oral methionine load (50 mg/kg of body weight in orange juice). Plasma concentrations of vitamin B12, folate and B6 were measured in the basal state. The effect of methionine load on the levels of methionine, total homocysteine, cysteine, glutathione and amino acids was examined. Indian women were significantly shorter and lighter compared with the American women and had lower plasma concentration of vitamins B12, folate and B6, essential amino acids and glutathione, but higher concentration of total homocysteine. The homocysteine response to methionine load was higher in Indian women. The plasma concentrations of glycine and serine increased in the Indian women after methionine (in juice) load. A significant negative correlation between plasma B6 and homocysteine (r= -0.70), and plasma folate and glycine and serine levels were observed in the Indian group (P<0.05) but not in the American group. Multi-nutrient insufficiency in the Indian women caused unique changes in markers of whole body protein and 1C metabolism. These data would be useful in developing nutrient intervention strategies.

Groundwater Availability Alters Soil-plant Nutrient Cycling in a Stand of Invasive, N-fixing Phreatophytes

NASA Astrophysics Data System (ADS)

Dudley, B. D.; Miyazawa, Y.; Hughes, F.; Ostertag, R.; Kettwich, S. K.; MacKenzie, R.; Dulaiova, H.; Waters, C. A.; Bishop, J.; Giambelluca, T. W.

2013-12-01

N-fixing phreatophytic trees are common in arid and semi-arid regions worldwide, and can play significant roles in modifying hydrology and soil-plant nutrient cycling where they are present. In light of reductions in groundwater levels in many arid regions we estimated annual transpiration rates at a stand level, and alterations to C, N and P accretion in soils as a function of groundwater depth in a ca.120 year old stand of Prosopis pallida along an elevation gradient in coastal leeward Hawaii. We measured sapflow and stand level sapwood area to quantify transpiration, and calculated groundwater transpiration rates using P. pallida stem water δ18O values. By measuring soil resistivity, we were able to compare the volume of groundwater transpired by these trees to groundwater depth across the stand. We examined nutrient deposition and accretion in soils in lowland areas of the stand with accessible shallow groundwater, compared to upland areas with no groundwater access, as indicated by stem water δ18O values. Resistivity results suggested that groundwater was at a height close to sea level throughout the stand. Transpiration was around 1900 m3 ha-1 year-1 in the areas of the stand closest to the sea (where groundwater was at around 1-4 m below ground level) and decreased to around a tenth of that volume where groundwater was not accessible. Litterfall rates over the course of the year studied were 17 times greater at lowland sites, but this litterfall contributed ca. 24 times the N, and 35 times the P of upland sites. Thus, groundwater access contributed to the total mass of nitrogen and phosphorus deposited in the form of litter through higher litter quantity and quality. Total N content of soils was 4.7 times greater and inorganic N pools were eight times higher at lowland plots. These results suggest that groundwater depth can have strong effects on soil-plant nutrient cycling, so that reductions in the availability of shallow groundwater are likely to impact soil nutrient availability in arid regions.

Effect of dietary protein on intake, nutrients utilization, nitrogen balance, blood metabolites, growth and puberty in growing Bhadawari buffalo (Bubalus bubalis) heifers.

PubMed

Singh, Sultan; Kushwaha, Badri Prasad; Maity, Subendu Bikas; Singh, Krishan Kunwar; Das, Nityanand

2015-01-01

Fifteen Bhadawari buffalo heifers of 207 ± 9.78 kg mean body weight were randomly distributed into three dietary groups to evaluate the effect of protein level on nutrient utilization, nitrogen (N) balance, growth rate, blood metabolites, and puberty. All animals were offered wheat straw-berseem diets supplemented with concentrate mixtures of similar energy (2.7 Mcal/kg) and different protein levels (14.3-22%). Animals of standard-protein group (SPG) were offered protein and energy as per requirement, while animals of low-protein group (LPG) and high-protein group (HPG) were fed 20% less and 20% more protein, respectively, than SPG. Feed dry matter (DM) and metabolizable energy (ME) intake (% body wt. and g/kg w(0.75)) were similar for all three diets; however, the crude protein (CP) and digestible crude protein (DCP) intake on percent body weight and per kilogram metabolic weight was higher (P < 0.05) in HPG than in SPG or LPG. Digestibility of CP, cellulose, and hemicellulose was higher (P < 0.05) in HPG versus LPG. Fecal N excretion was similar, while urinary N excretion was highest (P < 0.05) in HPG (74.83 g/day) compared with SPG (50.03 g/day) and LPG (47.88 g/day), which resulted in lower N retention in HPG than in the other dietary groups. Level of dietary N had no effect on blood metabolites viz. glucose, urea, and N. Digestible energy (DE) and ME contents of diets were identical, while DCP contents were higher (P < 0.05) in HPG than in LPG. Feed and nutrient (CP and ME) conversion efficiency to produce a unit kilogram weight gain was identical among the dietary groups. Dietary protein level had no effect on the heifer's weight and age at puberty. The mean growth rate of heifers at 240 days was higher (P > 0.05) in SPG (330.8 g/day) than in LPG (296.7 g/day), while the animals gained more weight in January to March months and the lowest weight in May to July months. Protein level had no effect on conception rate of heifers. Results revealed that 20% higher or less protein than the ICAR requirement had no significant (P > 0.05) on feed intake, nutrient conversion efficiency for weight gain, heifer growth, and puberty; however, 20% more protein increased urinary N loss.

Impact of levels of total digestible nutrients on microbiome, enzyme profile and degradation of feeds in buffalo rumen

PubMed Central

Kala, Anju; Kamra, D. N.; Kumar, Avinash; Agarwal, Neeta; Chaudhary, L. C.; Joshi, C. G.

2017-01-01

The present study was aimed at understanding a shift in rumen microbiome of buffaloes fed various levels of total digestible nutrients. To understand the process, the metagenomics of rumen microbes, in vivo and in vitro rumen fermentation studies were carried out. Three rumen fistulated adult male Murrah buffaloes were fed three isonitrogenous diets varying in total digestible nutrients (70, 85 and 100% of TDN requirement) in 3X3 switch over design. On dry matter basis, wheat straw/ roughage content were 81, 63 and 51% and that of maize grain was 8, 16 and 21% in three diets respectively. After 20 d of feeding, rumen liquor and rumen contents were sampled just before (0h) and 4h post feeding. Ruminococcus flavefaciens and R. albus (estimated with real time PCR) were higher in high roughage diets. The predominant phyla in all the three groups were Bacteroidetes, Firmicutes followed by Proteobacteria, Actinobacteria and Fibrobacteres. A core group of more than fifty rumen bacteria was present in all the animals with very little variations due to level of TDN. The most predominant bacterial genera reported in order of decreasing abundance were: Prevotella, Bacteroides, Clostridium, Ruminococcus, Eubacterium, Parabacteroides, Fibrobacter, Butyrivibrio etc. The higher diversity of the enyzmes families GH 23, GH 28, GH 39, GH 97, GH 106, and GH 127 (the enzymes active in fibre and starch degradation) were significantly higher on 100%TDN diet while CE 14 (required for the hydrolysis of bond between carbohydrate and lignin) was higher on low TDN (70%) diet, indicating ester bond cleavage was better in animals fed high roughage (wheat straw) diet. PMID:28207851

Impact of levels of total digestible nutrients on microbiome, enzyme profile and degradation of feeds in buffalo rumen.

PubMed

Kala, Anju; Kamra, D N; Kumar, Avinash; Agarwal, Neeta; Chaudhary, L C; Joshi, C G

2017-01-01

The present study was aimed at understanding a shift in rumen microbiome of buffaloes fed various levels of total digestible nutrients. To understand the process, the metagenomics of rumen microbes, in vivo and in vitro rumen fermentation studies were carried out. Three rumen fistulated adult male Murrah buffaloes were fed three isonitrogenous diets varying in total digestible nutrients (70, 85 and 100% of TDN requirement) in 3X3 switch over design. On dry matter basis, wheat straw/ roughage content were 81, 63 and 51% and that of maize grain was 8, 16 and 21% in three diets respectively. After 20 d of feeding, rumen liquor and rumen contents were sampled just before (0h) and 4h post feeding. Ruminococcus flavefaciens and R. albus (estimated with real time PCR) were higher in high roughage diets. The predominant phyla in all the three groups were Bacteroidetes, Firmicutes followed by Proteobacteria, Actinobacteria and Fibrobacteres. A core group of more than fifty rumen bacteria was present in all the animals with very little variations due to level of TDN. The most predominant bacterial genera reported in order of decreasing abundance were: Prevotella, Bacteroides, Clostridium, Ruminococcus, Eubacterium, Parabacteroides, Fibrobacter, Butyrivibrio etc. The higher diversity of the enyzmes families GH 23, GH 28, GH 39, GH 97, GH 106, and GH 127 (the enzymes active in fibre and starch degradation) were significantly higher on 100%TDN diet while CE 14 (required for the hydrolysis of bond between carbohydrate and lignin) was higher on low TDN (70%) diet, indicating ester bond cleavage was better in animals fed high roughage (wheat straw) diet.

Foliar sprays of citric acid and salicylic acid alter the pattern of root acquisition of some minerals in sweet basil (Ocimum basilicum L.)

PubMed Central

Ghazijahani, Noushin; Hadavi, Ebrahim; Jeong, Byoung R.

2014-01-01

The effect of foliar application of two levels of citric acid (CA; 0 and 7 mM) and two levels of salicylic acid (SA; 0 and 1 mM) combined with two levels of nutrient solution strength (full strength and half strength) on mineral acquisition by sweet basil were investigated. The experiment was conducted in a randomized block design arrangement with three replications. SA alone reduced the plant height and thickened the stem. Plants supplied with a full strength solution had a ticker stem, produced more biomass, and showed higher values of Fv/Fm. Some changes in the uptake pattern of some nutrients, especially boron and sulfur, were noticed. Higher boron concentrations in leaves were in plants sprayed with a combination of 7 mM CA and 1 mM of SA. Applying combination of CA and SA was more effective than using them individually that suggests an effective synergism between them. PMID:25400645

Evaluation of a combined macrophyte-epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA.

PubMed

Ray, Andrew M; Mebane, Christopher A; Raben, Flint; Irvine, Kathryn M; Marcarelli, Amy M

2014-07-01

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte-epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte-epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

Evaluation of a combined macrophyte–epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA

USGS Publications Warehouse

Ray, Andrew M.; Mebane, Christopher A.; Raben, Flint; Irvine, Kathryn M.; Marcarelli, Amy M.

2014-01-01

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte–epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte–epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

Is nutrient intake associated with physical activity levels in healthy young adults?

PubMed

Yan, Yi; Drenowatz, Clemens; Hand, Gregory A; Shook, Robin P; Hurley, Thomas G; Hebert, James R; Blair, Steven N

2016-08-01

Both physical activity (PA) and diet are important contributors to health and well-being; however, there is limited information on the association of these behaviours and whether observed associations differ by weight. The present study aimed to evaluate whether nutrient intake is associated with PA and if this association varies by weight in young adults. Cross-sectional study to analyse the association between PA and nutrient intake. Participants were stratified as normal weight (18·5 kg/m2

Bacterial and Phytoplankton Responses to Nutrient Amendments in a Boreal Lake Differ According to Season and to Taxonomic Resolution

PubMed Central

Peura, Sari; Eiler, Alexander; Hiltunen, Minna; Nykänen, Hannu; Tiirola, Marja; Jones, Roger I.

2012-01-01

Nutrient limitation and resource competition in bacterial and phytoplankton communities may appear different when considering different levels of taxonomic resolution. Nutrient amendment experiments conducted in a boreal lake on three occasions during one open water season revealed complex responses in overall bacterioplankton and phytoplankton abundance and biovolume. In general, bacteria were dominant in spring, while phytoplankton was clearly the predominant group in autumn. Seasonal differences in the community composition of bacteria and phytoplankton were mainly related to changes in observed taxa, while the differences across nutrient treatments within an experiment were due to changes in relative contributions of certain higher- and lower-level phylogenetic groups. Of the main bacterioplankton phyla, only Actinobacteria had a treatment response that was visible even at the phylum level throughout the season. With increasing resolution (from 75 to 99% sequence similarity) major responses to nutrient amendments appeared using 454 pyrosequencing data of 16S rRNA amplicons. This further revealed that OTUs (defined by 97% sequence similarity) annotated to the same highly resolved freshwater groups appeared to occur during different seasons and were showing treatment-dependent differentiation, indicating that OTUs within these groups were not ecologically coherent. Similarly, phytoplankton species from the same genera responded differently to nutrient amendments even though biovolumes of the majority of taxa increased when both nitrogen and phosphorus were added simultaneously. The bacterioplankton and phytoplankton community compositions showed concurrent trajectories that could be seen in synchronous succession patterns over the season. Overall, our data revealed that the response of both communities to nutrient changes was highly dependent on season and that contradictory results may be obtained when using different taxonomic resolutions. PMID:22715392

Tree seedlings respond to both light and soil nutrients in a Patagonian evergreen-deciduous forest.

PubMed

Promis, Alvaro; Allen, Robert B

2017-01-01

Seedlings of co-occurring species vary in their response to resource availability and this has implications for the conservation and management of forests. Differential shade-tolerance is thought to influence seedling performance in mixed Nothofagus betuloides-Nothofagus pumilio forests of Patagonia. However, these species also vary in their soil nutrient requirements. To determine the effects of light and soil nutrient resources on small seedlings we examined responses to an experimental reduction in canopy tree root competition through root trenching and restricting soil nutrient depletion through the addition of fertilizer. To understand the effect of light these treatments were undertaken in small canopy gaps and nearby beneath undisturbed canopy with lower light levels. Seedling diameter growth was greater for N. pumilio and height growth was greater for N. betuloides. Overall, diameter and height growth were greater in canopy gaps than beneath undisturbed canopy. Such growths were also greater with fertilizer and root trenching treatments, even beneath undisturbed canopy. Seedling survival was lower under such treatments, potentially reflecting thinning facilitated by resource induced growth. Finally, above-ground biomass did not vary among species although the less shade tolerant N. pumilio had higher below-ground biomass and root to shoot biomass ratio than the more shade tolerant N. betuloides. Above- and below-ground biomass were higher in canopy gaps so that the root to shoot biomass ratio was similar to that beneath undisturbed canopy. Above-ground biomass was also higher with fertilizer and root trenching treatments and that lowered the root to shoot biomass ratio. Restricting soil nutrient depletion allowed seedlings of both species to focus their responses above-ground. Our results support a view that soil nutrient resources, as well as the more commonly studied light resources, are important to seedlings of Nothofagus species occurring on infertile soils.

Phosphorus Availability, Phytoplankton Community Dynamics, and Taxon-Specific Phosphorus Status in the Gulf of Aqaba, Red Sea

NASA Astrophysics Data System (ADS)

Mackey, K. R.; Labiosa, R. G.; Calhoun, M.; Street, J. H.; Post, A. F.; Paytan, A.

2006-12-01

The relationships among phytoplankton taxon-specific phosphorus-status, phytoplankton community composition, and nutrient levels were assessed over three seasons in the Gulf of Aqaba, Red Sea. During summer and fall, stratified surface waters were depleted of nutrients and picophytoplankton populations comprised the majority of cells (80% and 88% respectively). In winter, surface nutrient concentrations were higher and larger phytoplankton were more abundant (63%). Cell specific alkaline phosphatase activity (APA) derived from enzyme labeled fluorescence was consistently low (less than 5%) in the picophytoplankton throughout the year, whereas larger cells expressed elevated APA during the summer and fall but less in the winter. A nutrient addition bioassay during the fall showed that, relative to control, APA was reduced by half in larger cells following addition of orthophosphate, whereas the APA of picophytoplankton remained low (less than 1%) across all treatments and the control. These results indicate that the most abundant phytoplankton are not limited by orthophosphate and only some subpopulations (particularly of larger cells) exhibit orthophosphate-limitation throughout the year. Our results indicate that orthophosphate availability influences phytoplankton ecology, correlating with shifts in phytoplankton community structure and the nutrient status of individual cells. The role of dissolved organic phosphorus as an important phosphorus source for marine phytoplankton in oligotrophic settings and the need for evaluating nutrient limitation at the taxa and/or single cell level (rather than inferring it from nutrient concentrations and ratios or bulk enzyme activity measurements) are highlighted.

Drug-nutrient interactions.

PubMed

Chan, Lingtak-Neander

2013-07-01

Drug-nutrient interactions are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient interactions are usually multifactorial. Failure to identify and properly manage drug-nutrient interactions can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient interactions can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of interactions, drug-nutrient interactions can be categorized into 4 main types. Each type of interaction can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient interactions are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient interactions remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient interactions can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient interactions.

Interactive Effects of Nutrient and Mechanical Stresses on Plant Morphology

PubMed Central

Puijalon, Sara; Lena, Jean-Paul; Bornette, Gudrun

2007-01-01

Background and Aims Plant species frequently encounter multiple stresses under natural conditions, and the way they cope with these stresses is a major determinant of their ecological breadth. The way mechanical (e.g. wind, current) and resource stresses act simultaneously on plant morphological traits has been poorly addressed, even if both stresses often interact. This paper aims to assess whether hydraulic stress affects plant morphology in the same way at different nutrient levels. Methods An examination was made of morphological variations of an aquatic plant species growing under four hydraulic stress (flow velocity) gradients located in four habitats distributed along a nutrient gradient. Morphological traits covering plant size, dry mass allocation, organ water content and foliage architecture were measured. Key Results Significant interactive effects of flow velocity and nutrient level were observed for all morphological traits. In particular, increased flow velocity resulted in size reductions under low nutrient conditions, suggesting an adaptive response to flow stress (escape strategy). On the other hand, moderate increases in flow velocity resulted in increased size under high nutrient conditions, possibly related to an inevitable growth response to a higher nutrient supply induced by water renewal at the plant surface. For some traits (e.g. dry mass allocation), a consistent sense of variation as a result of increasing flow velocity was observed, but the amount of variation was either reduced or amplified under nutrient-rich compared with nutrient-poor conditions, depending on the traits considered. Conclusions These results suggest that, for a given species, a stress factor may result, in contrasting patterns and hence strategies, depending on a second stress factor. Such results emphasize the relevance of studies on plant responses to multiple stresses for understanding the actual ecological breadth of species. PMID:17913725

Maternal Dietary Nutrient Intake and Its Association  with Preterm Birth: A Case-control Study in Beijing,  China.

PubMed

Zhang, Yan; Zhou, Hong; Perkins, Anthony; Wang, Yan; Sun, Jing

2017-03-01

This study aimed to evaluate dietary nutrient intake among Chinese pregnant women by comparison with Chinese Dietary Reference Intakes (DRIs) and to explore the association between dietary nutrients and preterm birth. A case-control design was conducted in Beijing with 130 preterm delivery mothers in case group and 381 term delivery mothers in control group. Information on mothers' diet was collected using a food frequency questionnaire, and nutrients and energy intakes were subsequently calculated based on DRIs. Multivariate analysis of variance was used to compare the differences between term and preterm groups in relation to dietary nutrients. Dietary nutrient intakes were imbalanced in both groups compared with Chinese DRIs. Preterm delivery mothers had a lower level of fat and vitamin E intake than term delivery mothers (p < 0.05). Multivariate analysis showed lower vitamin E intake in preterm delivery mothers with a prepregnancy BMI < 18.5 kg/m2 (p < 0.05) and higher carbohydrate intake in preterm delivery mothers with prepregnancy BMI ≥ 24 kg/m2 (p < 0.05). An imbalanced diet in both groups and low level of dietary intakes of fat and vitamin E in preterm group suggest health education measures should be taken to improve the dietary quality of pregnant women, especially for those with an abnormal prepregnancy BMI.

Reducing environmental risk of excessively fertilized soils and improving cucumber growth by Caragana microphylla-straw compost application in long-term continuous cropping systems.

PubMed

Tian, Yongqiang; Wang, Qing; Zhang, Weihua; Gao, Lihong

2016-02-15

Continuous cropping is a common agricultural practice in the word. In China, farmers often apply excessive fertilizers to fields in an attempt to maintain yields in continuous cropping systems. However, this practice often results in high nutrient concentrations in soils, nutrient pollution in leaching water and more crop disease. Here, we investigated 8 different soils from continuously cropped cucumbers in Northern China that grouped into those with extremely high nutrient levels (EHNL) and those with lower nutrient levels (LNL). All soils were treated with Caragana microphylla-straw (CMS) compost addition, and then were used to measure soil physiochemical and microbial properties, leaching water quality, plant root growth and cucumber fruit yield. In general, the EHNL-soil showed higher nitrate, phosphorus and potassium concentrations in the leaching water compared to the LNL-soil. However, the CMS compost application increased soil nutrient and water holding capacities, total microbial biomass (bacteria and fungi), root length, plant biomass and fruit yields, but decreased nutrient concentrations in the leaching water from the EHNL-soil. In addition, the CMS compost decreased the number of Fusarium oxysporum f. sp. cucumerinum in soils with very high concentration of mineral nitrogen. Our results infer that CMS compost application was an effective method for reducing environmental risk of excessively fertilized soils. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of socio-demographic variables and dairy use on the intake of essential macro- and micronutrients in 0.5-12-year-old Indonesian children.

PubMed

Widodo, Yekti; Sandjaja, Sandjaja; Sumedi, Edith; Khouw, Ilse; Deurenberg, Paul

2016-01-01

To study the associations between nutrient intake, dairy intake and socioeconomic variables. Food consumption data using 24 h recall were collected in 3600 children, aged 0.5 to 12 years old in addition to frequency of dairy use and anthropometric and sociodemographic variables. Overall height for age Z-score (HAZ) and body mass index for age Z-score (BAZ) values (mean±SE) were -1.40±0.03 and -0.48±0.03 respectively, associated with a high prevalence of stunting and thinness in the population. The overall percentage of children not using any dairy products was 71%, and this percentage increased steadily with age. The overall energy intake from dairy was 99±3 kcal/capita/day and the overall energy intake from dairy in dairy users was 291±7 kcal/day. Dairy use did not differ between boys and girls, but was higher in urban areas, higher if the education of the mother was higher and higher if the mother had a permanent job and if the wealth status of the family was in the upper levels. Nutrient intake after the age of 3 years was inadequate for energy and all nutrients except for protein. The achievement of Recommended Dietary Allowances (RDA) for all nutrients was higher in dairy users compared to non-dairy users, also after correcting for the confounding effect of the higher energy intake (from dairy) and socio-demographic variables. The contribution increased with increasing frequency of dairy use. Adequate dairy intake can substantially add to the achievement of RDA in Indonesian children.

Impacts of fertilization on water quality of a drained pine plantation: a worst case scenario.

PubMed

Beltran, Bray J; Amatya, Devendra M; Youssef, Mohamed; Jones, Martin; Callahan, Timothy J; Skaggs, R Wayne; Nettles, Jami E

2010-01-01

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31-yr) and one young (8-yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature-thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (alpha = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature-thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature-thinned watershed.

Effect of nutrient density on production performance, egg quality and humoral immune response of brown laying (Dahlem Red) hens in the tropics.

PubMed

Panda, Arun Kumar; Rao, Savaram Venkata Rama; Raju, Mantena Venkata Lakshmi Narasimha; Niranjan, Matam; Reddy, Maddula Ramkoti

2012-02-01

A study was conducted to evaluate the effect of various concentrations of metabolizable energy (ME) with graded incremental levels of crude protein (CP) and essential amino acids (lysine and methionine) on production performance, egg quality and humoral immune response of Dahlem Red laying hens. Four experimental diets based on maize-soybean meal-deoiled rice bran were prepared. Diet 1 was fed as a control diet containing 2,600 kcal ME/kg, 15% CP, 0.75% Lys and 0.36% Met, and in the other three diets (D2, D3 and D4), concentrations of the above nutrients were increased by 2.5%, 5.0% and 7.5%, respectively. The levels of Ca (3.5%) and available P (0.32) were constant in all the diets. Each diet was offered ad libitum from 28 to 40 weeks of age to eight replicates containing six birds in each replicate. The egg production, egg weight and egg mass (in grams of egg per hen per day) were not affected by increasing the nutrient density up to 7.5% (2,795 kcal ME/kg diet) compared to the control group (2,600 ME/kg diet). However, feed consumption and feed efficiency (in grams of egg per gram of feed) were influenced by the variation in the nutrient density of diets. As the nutrient density increased by 5% (2,730 ME/kg diet), birds consumed significantly (P < 0.001) less feed. The birds in the 7.5% higher density group produced significantly (P < 0.05) higher egg mass per unit feed consumption compared to the control diet. Increasing nutrient density up to 7.5% had no effect on relative weight of albumen, yolk or shell. The Haugh unit, yolk colour and shell thickness were also not affected due to variation in the nutrient density. The humoral immune response measured at 34 and 40 weeks was progressively improved by increasing the nutrient density up to 5%. Increasing the nutrient density beyond 5% in the diet had no further influence on the humoral immune response. Based on the results of the present study, it can be concluded that Dahlem Red laying hens required 2,795 kcal/kg ME, 16% CP, 0.8% lysine and 0.4% methionine for eliciting optimum performance and immune response during 28 to 40 weeks of age.

Nitrogen and organic carbon cycling processes in tidal marshes and shallow estuarine habitats

NASA Astrophysics Data System (ADS)

Bergamaschi, B. A.; Downing, B. D.; Pellerin, B. A.; Kraus, T. E. C.; Fleck, J.; Fujii, R.

2016-02-01

Tidal wetlands and shallow water habitats can be sites of high aquatic productivity, and they have the potential of exchanging this newly produced organic carbon with adjacent deeper habitats. Indeed, export of organic carbon from wetlands and shallow water habitats to pelagic food webs is one of the primary ecosystem functions targeted in tidal wetland restorations. Alternatively, wetlands and shallow water habitats can function as retention areas for nutrients due to the nutrient demand of emergent macrophytes and denitrification in anoxic zones. They can also remove phytoplankton and non-algal particles from the aquatic food webs because the shallower waters can result in higher rates of benthic grazing and higher settling due to lower water velocities. We conducted studies in wetland and channel sites in the San Francisco estuary (USA) to investigate the dynamics of nutrients and carbon production at a variety of temporal scales. We collected continuous time series of nutrients, oxygen, chlorophyll and pH in conjunction with continuous acoustic measurement of water velocity and discharge to provide mass controls and used simple biogeochemical models to assess rates. We found a high degree of temporal variability in individual systems, corresponding to, for example, changes in nutrient supply, water level, light level, wind, wind direction, and other physical factors. There was also large variability among the different systems, probably due to differences in flows and geomorphic features. We compare the aquatic productivity of theses environments and speculate as to the formative elements of each. Our findings demonstrate the complex interaction between physical, chemical, and biological factors that determine the type of production and degree of export from tidal wetlands and shallow water habitats, suggesting that a clearer picture of these processes is important for guiding future large scale restoration efforts.

Resiliency of the Chesapeake Bay to Pollution Levels Following Storms and Based on Land-Use

NASA Astrophysics Data System (ADS)

Hasan, M.; Pavelsky, T.

2015-12-01

As pollution levels, transformations in land use, and ecological loss continue to increase in the Chesapeake Bay, questions arise as to whether this estuary, the largest in North America, will experience a change in the duration and levels of storm-related sediment and nutrient spikes. We use a combination of satellite data and previously-collected field measurements to study this question. We compare same-day and same-pixel NASA MODIS satellite data to in situ observations of sediment and nutrient concentrations over 20 years, and found that for at least 6 tributaries, the r2 value for a linear regression between the satellite reflectance and fieldwork measures of nitrogen, phosphorus, or suspended sediment concentrations exceeded 0.7, while for at least 12 tributaries, the r2 value exceeded 0.5. We took advantage of this relationship to estimate sediment and nutrient concentrations in the Chesapeake following major storm events, even in the absence of continuous in situ data. We studied sediment/nutrient levels daily following the storm, for every date on which a cloud-free MODIS image was available, for a month. The storms included 2003's Hurricane Isabel, 2011's Hurricane Irene, and 2012's Superstorm Sandy. The tributaries we focused on were the York and Piankatank Rivers of southern Virginia (heavily forested), the Potomac River (heavily urban), and the Nanticoke River of the Eastern Shore (heavily farmed). Results show that in the Potomac River, which over the last 15 years has experience a signifiant increase in urbanization, sediments and nutrients persist for longer periods and at higher levels compared to less urbanized rivers.

Eutrophication triggers contrasting multilevel feedbacks on litter accumulation and decomposition in fens.

PubMed

Emsens, W-J; Aggenbach, C J S; Grootjans, A P; Nfor, E E; Schoelynck, J; Struyf, E; van Diggelen, R

2016-10-01

Eutrophication is a major threat for the persistence of nutrient-poor fens, as multilevel feedbacks on decomposition rates could trigger carbon loss and increase nutrient cycling. Here, we experimentally investigate the effects of macronutrient (NPK) enrichment on litter quality of six species of sedge (Carex sp.), which we relate to litter decomposition rates in a nutrient-poor and nutrient-rich environment. Our research focused on four levels: we examined how eutrophication alters (1) fresh litter production ("productivity shift"), (2) litter stoichiometry within the same species ("intraspecific shift"), (3) overall litter stoichiometry of the vegetation under the prediction that low-competitive species are outcompeted by fast-growing competitors ("interspecific shift"), and (4) litter decomposition rates due to an altered external environment (e.g., shifts in microbial activity; "exogenous shift"). Eutrophication triggered a strong increase in fresh litter production. Moreover, individuals of the same species produced litter with lower C:N and C:P ratios, higher K contents, and lower lignin, Ca and Mg contents (intraspecific shift), which increased litter decomposability. In addition, species typical for eutrophic conditions produced more easily degradable litter than did species typical for nutrient-poor conditions (interspecific shift). However, the effects of nutrient loading of the external environment (exogenous shift) were contradictory. Here, interactions between litter type and ambient nutrient level indicate that the (exogenous) effects of eutrophication on litter decomposition rates are strongly dependent of litter quality. Moreover, parameters of litter quality only correlated with decomposition rates for litter incubated in nutrient-poor environments, but not in eutrophic environments. This suggests that rates of litter decomposition can be uncoupled from litter stoichiometry under eutrophic conditions. In conclusion, our results show that eutrophication affects litter accumulation and -decomposition at multiple levels, in which stimulatory and inhibitory effects interact. The cumulative effect of these interactions ultimately determine whether peatlands remain sinks or become sources of carbon under eutrophic conditions. © 2016 by the Ecological Society of America.

Adherence to dietary recommendations for Swedish adults across categories of greenhouse gas emissions from food.

PubMed

Sjörs, Camilla; Hedenus, Fredrik; Sjölander, Arvid; Tillander, Annika; Bälter, Katarina

2017-12-01

To explore associations between diet-related greenhouse gas emissions (GHGE), nutrient intakes and adherence to the Nordic Nutrition Recommendations among Swedish adults. Diet was assessed by 4d food records in the Swedish National Dietary Survey. GHGE was estimated by linking all foods to carbon dioxide equivalents, using data from life cycle assessment studies. Participants were categorized into quartiles of energy-adjusted GHGE and differences between GHGE groups regarding nutrient intakes and adherence to nutrient recommendations were explored. Sweden. Women (n 840) and men (n 627) aged 18-80 years. Differences in nutrient intakes and adherence to nutrient recommendations between GHGE groups were generally small. The dietary intake of participants with the lowest emissions was more in line with recommendations regarding protein, carbohydrates, dietary fibre and vitamin D, but further from recommendations regarding added sugar, compared with the highest GHGE group. The overall adherence to recommendations was found to be better among participants with lower emissions compared with higher emissions. Among women, 27 % in the lowest GHGE group adhered to at least twenty-three recommendations compared with only 12 % in the highest emission group. For men, the corresponding figures were 17 and 10 %, respectively. The study compared nutrient intakes as well as adherence to dietary recommendations for diets with different levels of GHGE from a national dietary survey. We found that participants with low-emission diets, despite higher intake of added sugar, adhered to a larger number of dietary recommendations than those with high emissions.

Interactive effects of nutrient additions and predation on infaunal communities

USGS Publications Warehouse

Posey, M.H.; Alphin, T.D.; Cahoon, L.; Lindquist, D.; Becker, M.E.

1999-01-01

Nutrient additions represent an important anthropogenic stress on coastal ecosystems. At moderate levels, increased nutrients may lead to increased primary production and, possibly, to increased biomass of consumers although complex trophic interactions may modify or mask these effects. We examined the influence of nutrient additions and interactive effects of trophic interactions (predation) on benthic infaunal composition and abundances through small-scale field experiments in 2 estuaries that differed in ambient nutrient conditions. A blocked experimental design was used that allowed an assessment of direct nutrient effects in the presence and absence of predation by epibenthic predators as well as an assessment of the independent effects of predation. Benthic microalgal production increased with experimental nutrient additions and was greater when infaunal abundances were lower, but there were no significant interactions between these factors. Increased abundances of one infaunal taxa, Laeonereis culveri, as well as the grazer feeding guild were observed with nutrient additions and a number of taxa exhibited higher abundances with predator exclusion. In contrast to results from freshwater systems there were no significant interactive effects between nutrient additions and predator exclusion as was predicted. The infaunal responses observed here emphasize the importance of both bottom-up (nutrient addition and primary producer driven) and top-down (predation) controls in structuring benthic communities. These processes may work at different spatial and temporal scales, and affect different taxa, making observation of potential interactive effects difficult.

Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Schulz, K. G.; Bellerby, R. G. J.; Brussaard, C. P. D.; Büdenbender, J.; Czerny, J.; Engel, A.; Fischer, M.; Koch-Klavsen, S.; Krug, S. A.; Lischka, S.; Ludwig, A.; Meyerhöfer, M.; Nondal, G.; Silyakova, A.; Stuhr, A.; Riebesell, U.

2013-01-01

Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in Kongsfjorden on the west coast of Spitsbergen (Norway), in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a), peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured as high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2-related shifts in nutrient flow into different phytoplankton groups (mainly dinoflagellates, prasinophytes and haptophytes) could have consequences for future organic matter flow to higher trophic levels and export production, with consequences for ecosystem productivity and atmospheric CO2.

Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Schulz, K. G.; Bellerby, R. G. J.; Brussaard, C. P. D.; Büdenbender, J.; Czerny, J.; Engel, A.; Fischer, M.; Koch-Klavsen, S.; Krug, S. A.; Lischka, S.; Ludwig, A.; Meyerhöfer, M.; Nondal, G.; Silyakova, A.; Stuhr, A.; Riebesell, U.

2012-09-01

Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in 2010, in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a), peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured at high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2 related shifts in nutrient flow into different phytoplankton groups (mainly diatoms, dinoflagellates, prasinophytes and haptophytes) could have consequences for future organic matter flow to higher trophic levels and export production, with consequences for ecosystem productivity and atmospheric CO2.

Phytoplankton Assemblage Characteristics in Recurrently Fluctuating Environments

PubMed Central

Roelke, Daniel L.; Spatharis, Sofie

2015-01-01

Annual variations in biogeochemical and physical processes can lead to nutrient variability and seasonal patterns in phytoplankton productivity and assemblage structure. In many coastal systems river inflow and water exchange with the ocean varies seasonally, and alternating periods can arise where the nutrient most limiting to phytoplankton growth switches. Transitions between these alternating periods can be sudden or gradual and this depends on human activities, such as reservoir construction and interbasin water transfers. How such activities might influence phytoplankton assemblages is largely unknown. Here, we employed a multispecies, multi-nutrient model to explore how nutrient loading switching mode might affect characteristics of phytoplankton assemblages. The model is based on the Monod-relationship, predicting an instantaneous growth rate from ambient inorganic nutrient concentrations whereas the limiting nutrient at any given time was determined by Liebig’s Law of the Minimum. Our simulated phytoplankton assemblages self-organized from species rich pools over a 15-year period, and only the surviving species were considered as assemblage members. Using the model, we explored the interactive effects of complementarity level in trait trade-offs within phytoplankton assemblages and the amount of noise in the resource supply concentrations. We found that the effect of shift from a sudden resource supply transition to a gradual one, as observed in systems impacted by watershed development, was dependent on the level of complementarity. In the extremes, phytoplankton species richness and relative overyielding increased when complementarity was lowest, and phytoplankton biomass increased greatly when complementarity was highest. For low-complementarity simulations, the persistence of poorer-performing phytoplankton species of intermediate R*s led to higher richness and relative overyielding. For high-complementarity simulations, the formation of phytoplankton species clusters and niche compression enabled higher biomass accumulation. Our findings suggest that an understanding of factors influencing the emergence of life history traits important to complementarity is necessary to predict the impact of watershed development on phytoplankton productivity and assemblage structure. PMID:25799563

Effect of Meloidogyne arenaria and Mulch Type on Okra in Microplot Experiments.

PubMed

Ritzinger, C H; McSorley, R; Gallaher, R N

1998-12-01

The effects of perennial peanut (Arachis glabrata) hay, an aged yard-waste compost (mainly woodchips), and a control treatment without amendment were determined on two population levels of root-knot (Melaidogyne arenaria) nematode over three consecutive years in field microplots. Okra (Hibiscus esculentus, susceptible to the root-knot nematode) and a rye (Secale cereale) cover crop (poor nematode host) were used in the summer and winter seasons, respectively. The organic amendment treatments affected plant growth parameters. In the first year, okra yields were greatest in peanut-amended plots. Yield differences with amendment treatment diminished in the second and third years. Okra plant height, total fruit weight, and fruit number were greater with the lower population level of the root-knot nematode. Residual levels of nutrients in soil were greater where root-knot nematode levels and damage were higher and plant growth was poor. Nutrient levels affected the growth of a subsequent rye cover crop.

Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

PubMed Central

2011-01-01

Background To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Results Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. Conclusions The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread in European resource-rich riparian forests and impedes its establishment under closed-canopy hardwood forests. PMID:22115342

Measuring calcium, potassium, and nitrate in plant nutrient solutions using ion-selective electrodes in hydroponic greenhouse of some vegetables.

PubMed

Vardar, Gökay; Altıkatoğlu, Melda; Ortaç, Deniz; Cemek, Mustafa; Işıldak, İbrahim

2015-01-01

Generally, the life cycle of plants depends on the uptake of essential nutrients in a balanced manner and on toxic elements being under a certain concentration. Lack of control of nutrient levels in nutrient solution can result in reduced plant growth and undesired conditions such as blossom-end rot. In this study, sensitivity and selectivity tests for various polyvinylchloride (PVC)-based ion-selective membranes were conducted to identify those suitable for measuring typical concentration ranges of macronutrients, that is, NO(3-), K(+), and Ca(2+), in hydroponic solutions. The sensitivity and selectivity of PVC-membrane-based ion-selective sensors prepared with tetradodecylammoniumnitrate for NO(3-), valinomycin for K(+), and Ca ionophore IV for Ca(2+) were found to be satisfactory for measuring NO(3-), K(+), and Ca(2+) ions in nutrient solutions over typical ranges of hydroponic concentrations. Potassium, calcium, and nitrate levels that were utilized by cucumber and tomato seedlings in the greenhouse were different. The findings show that tomato plants consumed less amounts of nitrate than cucumber plants over the first 2 months of their growth. We also found that the potassium intake was higher than other nutritional elements tested for all plants. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Phosphorus, zinc, and boron influence yield components in Earliglow strawberry

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, G.M.; Pritts, M.P.

1993-01-01

The main effects and interactions of soil-applied P, B, and Zn on yield and its components were examined in the field at two pH levels with Earliglow' strawberries (Fragaria ananassa Duch.). Applied nutrients had significant effects on several yield components, but responses depended on the levels of other nutrients or the soil pH. At a soil pH of 5.5, yield responded linearly to B and quadratically to P. At pH 6.5, P interacted with B and Zn. Fruit count per inflorescence was the yield component most strongly associated with yield, followed by individual fruit weight. However, these two yield componentsmore » responded differently to soil-applied nutrients. Foliar nutrient levels generally did not increase with the amount of applied nutrient, but often an applied nutrient had a strong effect on the level of another nutrient. Leaf nutrient levels were often correlated with fruit levels, but foliar and fruit levels at harvest were not related to reproductive performance. The study identifies some of the problems inherent in using foliar nutrient levels to predict a yield response and demonstrates how plant responses to single nutrients depend on soil chemistry and the presence of other nutrients.« less

Composition of methane-oxidizing bacterial communities as a function of nutrient loading in the Florida everglades.

PubMed

Chauhan, Ashvini; Pathak, Ashish; Ogram, Andrew

2012-10-01

Agricultural runoff of phosphorus (P) in the northern Florida Everglades has resulted in several ecosystem level changes, including shifts in the microbial ecology of carbon cycling, with significantly higher methane being produced in the nutrient-enriched soils. Little is, however, known of the structure and activities of methane-oxidizing bacteria (MOB) in these environments. To address this, 0 to 10 cm plant-associated soil cores were collected from nutrient-impacted (F1), transition (F4), and unimpacted (U3) areas, sectioned in 2-cm increments, and methane oxidation rates were measured. F1 soils consumed approximately two-fold higher methane than U3 soils; additionally, most probable numbers of methanotrophs were 4-log higher in F1 than U3 soils. Metabolically active MOB containing pmoA sequences were characterized by stable-isotope probing using 10 % (v/v) (13)CH(4). pmoA sequences, encoding the alpha subunit of methane monooxygenase and related to type I methanotrophs, were identified from both impacted and unimpacted soils. Additionally, impacted soils also harbored type II methanotrophs, which have been shown to exhibit preferences for high methane concentrations. Additionally, across all soils, novel pmoA-type sequences were also detected, indicating presence of MOB specific to the Everglades. Multivariate statistical analyses confirmed that eutrophic soils consisted of metabolically distinct MOB community that is likely driven by nutrient enrichment. This study enhances our understanding on the biological fate of methane being produced in productive wetland soils of the Florida Everglades and how nutrient-enrichment affects the composition of methanotroph bacterial communities.

Primary Productivity Regime and Nutrient Removal in the Danube Estuary

NASA Astrophysics Data System (ADS)

Humborg, C.

1997-11-01

The primary productivity regime, as well as the distribution of dissolved inorganic nutrients and particulate organic matter in the Danube estuary, were investigated during several cruises at different discharge regimes of the Danube River. The shallowness of the upper surface layer due to insignificant tidal mixing and strong stratification of the Danube estuary, as well as the high nutrient concentrations, are favourable for elevated primary production. The incident light levels at the bottom of the upper surface layer of the water column (0·5-3·0 m) were generally higher than 20% of the surface irradiance. Elevated chlorophyll (Chl) aconcentrations with maxima at mid salinities were found during each survey. Within the upper mixed layer estimated primary production of 0·2-4·4 g m-2day-1is very high compared with estuaries of other major world rivers. Mixing diagrams of dissolved inorganic nutrients reveal removal of significant quantities of nutrients during estuarine mixing. These observations were consistent with the distribution of particular organic matter, which was negatively correlated to the nutrient distribution during each survey. C:Chl aratios, as well as the elevated estimated production, indicate that biological transformation processes govern the nutrient distribution in this estuary.

Impact of Breakfast Skipping and Breakfast Choice on the Nutrient Intake and Body Mass Index of Australian Children

PubMed Central

Fayet-Moore, Flavia; Kim, Jean; Sritharan, Nilani; Petocz, Peter

2016-01-01

Recent data on breakfast consumption among Australian children are limited. This study examined the impact of breakfast skipping and breakfast type (cereal or non-cereal) on nutrient intakes, likelihood of meeting nutrient targets and anthropometric measures. A secondary analysis of two 24-h recall data from the 2007 Australian National Children’s Nutrition and Physical Activity Survey was conducted (2–16 years; n = 4487) to identify (a) breakfast skippers and (b) breakfast consumers, with breakfast consumers further sub-divided into (i) non-cereal and (ii) cereal consumers. Only 4% skipped breakfast and 59% of skippers were 14–16 years. Breakfast consumers had significantly higher intakes of calcium and folate, and significantly lower intakes of total fat than breakfast skippers. Cereal consumers were more likely to meet targets and consume significantly higher fibre, calcium, iron, had significantly higher intakes of folate, total sugars and carbohydrate, and significantly lower intakes of total fat and sodium than non-cereal consumers. The prevalence of overweight was lower among breakfast consumers compared to skippers, and among cereal consumers compared to-cereal consumers (p < 0.001), while no significant differences were observed for mean body mass index (BMI), BMI z-score, waist circumference and physical activity level across the categories. Breakfast and particularly breakfast cereal consumption contributes important nutrients to children’s diets. PMID:27517957

Effects of nitrogen fertilization on the phenolic composition and antioxidant properties of basil (Ocimum basilicum L.).

PubMed

Nguyen, Phuong M; Niemeyer, Emily D

2008-09-24

Many herbs and spices have been shown to contain high levels of polyphenolic compounds with potent antioxidant properties. In the present study, we explore how nutrient availability, specifically nitrogen fertilization, affects the production of polyphenolic compounds in three cultivars (Dark Opal, Genovese, and Sweet Thai) of the culinary herb, basil ( Ocimum basilicum L.). Nitrogen fertilization was found to have a significant effect on total phenolic levels in Dark Opal ( p < 0.001) and Genovese ( p < 0.001) basil with statistically higher phenolic contents observed when nutrient availability was limited at the lowest (0.1 mM) applied nitrogen treatment. Similarly, basil treated at the lowest nitrogen fertilization level generally contained significantly higher rosmarinic ( p = 0.001) and caffeic ( p = 0.001) acid concentrations than basil treated at other nitrogen levels. Nitrogen fertilization also affected antioxidant activity ( p = 0.002) with basil treated at the highest applied nitrogen level, 5.0 mM, exhibiting lower antioxidant activity than all other nitrogen treatments. The anthocyanin content of Dark Opal basil was not affected by applied nitrogen level, but anthocyanin concentrations were significantly impacted by growing season ( p = 0.001). Basil cultivar was also determined to have a statistically significant effect on total phenolic levels, rosmarinic and caffeic acid concentrations, and antioxidant activities.

Effects of Inclusion Levels of Wheat Bran and Body Weight on Ileal and Fecal Digestibility in Growing Pigs

PubMed Central

Huang, Q.; Su, Y. B.; Li, D. F.; Liu, L.; Huang, C. F.; Zhu, Z. P.; Lai, C. H.

2015-01-01

The objective of this study was to determine the effects of graded inclusions of wheat bran (0%, 9.65%, 48.25% wheat bran) and two growth stages (from 32.5 to 47.2 kg and 59.4 to 78.7 kg, respectively) on the apparent ileal digestibility (AID), apparent total tract digestibility (ATTD) and hindgut fermentation of nutrients and energy in growing pigs. Six light pigs (initial body weight [BW] 32.5±2.1 kg) and six heavy pigs (initial BW 59.4±3.2 kg) were surgically prepared with a T-cannula in the distal ileum. A difference method was used to calculate the nutrient and energy digestibility of wheat bran by means of comparison with a basal diet consisting of corn-soybean meal (0% wheat bran). Two additional diets were formulated by replacing 9.65% and 48.25% wheat bran by the basal diet, respectively. Each group of pigs was allotted to a 6×3 Youden square design, and pigs were fed to three experimental diets during three 11-d periods. Hindgut fermentation values were calculated as the differences between ATTD and AID values. For the wheat bran diets, the AID and ATTD of dry matter (DM), ash, organic matter (OM), carbohydrates (CHO), gross energy (GE), and digestible energy (DE) decreased with increasing inclusion levels of wheat bran (p<0.05). While only AID of CHO and ATTD of DM, ash, OM, CHO, GE, and DE content differed (p<0.05) when considering the BW effect. For the wheat bran ingredient, there was a wider variation effect (p<0.01) on the nutrient and energy digestibility of wheat bran in 9.65% inclusion level due to the coefficient of variation (CV) of the nutrient and energy digestibility being higher at 9.65% compared to 48.25% inclusion level of wheat bran. Digestible energy content of wheat bran at 48.25% inclusion level (4.8 and 6.7 MJ/kg of DM, respectively) fermented by hindgut was significantly higher (p<0.05) than that in 9.65% wheat bran inclusion level (2.56 and 2.12 MJ/kg of DM, respectively), which was also affected (p<0.05) by two growth stages. This increase in hindgut fermentation caused the difference in ileal DE (p<0.05) to disappear at total tract level. All in all, increasing wheat bran levels in diets negatively influences the digestibility of some nutrients in pigs, while it positively affects the DE fermentation in the hindgut. PMID:25925062

Biomass and nutrient allocation strategies in a desert ecosystem in the Hexi Corridor, northwest China.

PubMed

Zhang, Ke; Su, YongZhong; Yang, Rong

2017-07-01

The allocation of biomass and nutrients in plants is a crucial factor in understanding the process of plant structures and dynamics to different environmental conditions. In this study, we present a comprehensive scaling analysis of data from a desert ecosystem to determine biomass and nutrient (carbon (C), nitrogen (N), and phosphorus (P)) allocation strategies of desert plants from 40 sites in the Hexi Corridor. We found that the biomass and levels of C, N, and P storage were higher in shoots than in roots. Roots biomass and nutrient storage were concentrated at a soil depth of 0-30 cm. Scaling relationships of biomass, C storage, and P storage between shoots and roots were isometric, but that of N storage was allometric. Results of a redundancy analysis (RDA) showed that soil nutrient densities were the primary factors influencing biomass and nutrient allocation, accounting for 94.5% of the explained proportion. However, mean annual precipitation was the primary factor influencing the roots biomass/shoots biomass (R/S) ratio. Furthermore, Pearson's correlations and regression analyses demonstrated that although the biomass and nutrients that associated with functional traits primarily depended on soil conditions, mean annual precipitation and mean annual temperature had greater effects on roots biomass and nutrient storage.

A novel approach to selecting and weighting nutrients for nutrient profiling of foods and diets.

PubMed

Arsenault, Joanne E; Fulgoni, Victor L; Hersey, James C; Muth, Mary K

2012-12-01

Nutrient profiling of foods is the science of ranking or classifying foods based on their nutrient composition. Most profiling systems use similar weighting factors across nutrients due to lack of scientific evidence to assign levels of importance to nutrients. Our aim was to use a statistical approach to determine the nutrients that best explain variation in Healthy Eating Index (HEI) scores and to obtain β-coefficients for the nutrients for use as weighting factors for a nutrient-profiling algorithm. We used a cross-sectional analysis of nutrient intakes and HEI scores. Our subjects included 16,587 individuals from the National Health and Nutrition Examination Survey 2005-2008 who were 2 years of age or older and not pregnant. Our main outcome measure was variation (R(2)) in HEI scores. Linear regression analyses were conducted with HEI scores as the dependent variable and all possible combinations of 16 nutrients of interest as independent variables, with covariates age, sex, and ethnicity. The analyses identified the best 1-nutrient variable model (with the highest R(2)), the best 2-nutrient variable model, and up to the best 16-nutrient variable model. The model with 8 nutrients explained 65% of the variance in HEI scores, similar to the models with 9 to 16 nutrients, but substantially higher than previous algorithms reported in the literature. The model contained five nutrients with positive β-coefficients (ie, protein, fiber, calcium, unsaturated fat, and vitamin C) and three nutrients with negative coefficients (ie, saturated fat, sodium, and added sugar). β-coefficients from the model were used as weighting factors to create an algorithm that generated a weighted nutrient density score representing the overall nutritional quality of a food. The weighted nutrient density score can be easily calculated and is useful for describing the overall nutrient quality of both foods and diets. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Consumption of ready-to-eat cereals (RTEC) among Malaysian children and association with socio-demographics and nutrient intakes - findings from the MyBreakfast study.

PubMed

Mohd Nasir, Mohd Taib; Nurliyana, Abdul Razak; Norimah, A Karim; Jan Mohamed, Hamid Jan B; Tan, Sue Yee; Appukutty, Mahenderan; Hopkins, Sinead; Thielecke, Frank; Ong, Moi Kim; Ning, Celia; Tee, E Siong

2017-01-01

Background : The association between different types of breakfast meals and nutrient intakes has been studied to a lesser extent. Objective : This study compared nutrient intakes at breakfast and throughout the day between Malaysian children who consumed ready-to-eat cereals (RTEC) and those who did not. Methods : Anthropometric and dietary data for 1955 children aged 6-12 years from the MyBreakfast study were used in the analysis. Results : Overall, 18% of the children consumed RTEC at breakfast on at least one of the recall days. RTEC consumption was associated with younger age, urban areas, higher income and education level of parents. Among consumers, RTEC contributed 10% and 15% to daily intakes of calcium and iron respectively and ≥20% to daily intakes of vitamin C, thiamin, riboflavin and niacin. RTEC consumers had significantly higher mean intakes of vitamin C, thiamin, riboflavin, niacin, calcium, iron and sugar but lower intakes of fat and sodium than non-RTEC consumers at breakfast and for the total day. Conclusion : Consumption of fortified RTEC at breakfast was associated with lower fat and sodium intakes and higher intakes of several micronutrients both at breakfast and for the total day. However, total sugar intakes appeared to be higher.

A comparison of algal, macroinvertebrate, and fish assemblage indices for assessing low-level nutrient enrichment in wadeable Ozark streams

USGS Publications Warehouse

Justus, B.G.; Femmer, Suzanne R.; Davis, Jerri V.; Petersen, James C.; Wallace, J.E.

2010-01-01

All three biotic indices were negatively correlated to nutrient concentrations but the algal index had a higher correlation (rho = −0.89) than did the macroinvertebrate and fish indices (rho = −0.63 and −0.58, respectively). Biotic index scores were lowest and nutrient concentrations were highest for streams with basins having the highest poultry and cattle production. Because of the availability of litter for fertilizer and associated increases in grass and hay production, cattle feeding capacity increases with poultry production. Studies are needed that address the synergistic effect of poultry and cattle production on Ozark streams in high production areas before ecological risks can be adequately addressed.

Colony patterning and collective hyphal growth of filamentous fungi

NASA Astrophysics Data System (ADS)

Matsuura, Shu

2002-11-01

Colony morphology of wild and mutant strains of Aspergillus nidulans at various nutrient and agar levels was investigated. Two types of colony patterning were found for these strains. One type produced uniform colonies at all nutrient and agar levels tested, and the other exhibited morphological change into disordered ramified colonies at low nutrient levels. Both types showed highly condensed compact colonies at high nutrient levels on low agar media that was highly diffusive. Disordered colonies were found to develop with low hyphal extension rates at low nutrient levels. To understand basic pattern selection rules, a colony model with three parameters, i.e., the initial nutrient level and the step length of nutrient random walk as the external parameters, and the frequency of nutrient uptake as an internal parameter, was constructed. At low nutrient levels, with decreasing nutrient uptake frequency under diffusive conditions, the model colony exhibited onsets of disordered ramification. Further, in the growth process of A. nidulans, reduction of hyphal extension rate due to a population effect of hyphae was found when hyphae form three-dimensional dense colonies, as compared to the case in which hyphal growth was restricted into two-dimensional space. A hyphal population effect was introduced in the colony model. Thickening of colony periphery due to the population effect became distinctive as the nutrient diffusion effect was raised at high nutrient levels with low hyphal growth rate. It was considered that colony patterning and onset of disorder were strongly governed by the combination of nutrient diffusion and hyphal growth rate.

Innu food consumption patterns: traditional food and body mass index.

PubMed

Atikessé, Laura; de Grosbois, Sylvie Boucher; St-Jean, Mélissa; Penashue, Basile Mashen; Benuen, Manipia

2010-01-01

Food consumption patterns of an Innu community were described and the benefits of traditional food (TF) were investigated in relation to body mass index (BMI). A cross-sectional study was conducted using food frequency and 24-hour recall questionnaires to evaluate consumption patterns (n=118) and to assess energy and nutrient intakes from TF and store-bought food (SBF) (n=161). Body mass index was calculated with a sub-sample of 45 participants. Mean yearly TF meal consumption was significantly related to age (p=0.05). Participants reporting high TF and low SBF consumption presented with a normal body weight (BMI=24.1) at the lower quartile and a slightly overweight status (BMI=25.8) at the median. Mean values for protein and carbohydrate intake were higher than the Dietary Reference Intakes, whereas dietary fibre intake was below these guidelines for both genders. Store-bought food provided higher levels of energy and nutrients, except for protein. Although Innu consume high amounts of TF and SBF, a lack of some essential nutrients was observed. Because TF intake was related to a tendency toward a lower BMI, a combined, targeted diet could be proposed. Health services could reinforce the importance of TF consumption and promote traditional dietary practices that offer advantages at many levels.

Structuring of Bacterioplankton Diversity in a Large Tropical Bay

PubMed Central

Gregoracci, Gustavo B.; Nascimento, Juliana R.; Cabral, Anderson S.; Paranhos, Rodolfo; Valentin, Jean L.; Thompson, Cristiane C.; Thompson, Fabiano L.

2012-01-01

Structuring of bacterioplanktonic populations and factors that determine the structuring of specific niche partitions have been demonstrated only for a limited number of colder water environments. In order to better understand the physical chemical and biological parameters that may influence bacterioplankton diversity and abundance, we examined their productivity, abundance and diversity in the second largest Brazilian tropical bay (Guanabara Bay, GB), as well as seawater physical chemical and biological parameters of GB. The inner bay location with higher nutrient input favored higher microbial (including vibrio) growth. Metagenomic analysis revealed a predominance of Gammaproteobacteria in this location, while GB locations with lower nutrient concentration favored Alphaproteobacteria and Flavobacteria. According to the subsystems (SEED) functional analysis, GB has a distinctive metabolic signature, comprising a higher number of sequences in the metabolism of phosphorus and aromatic compounds and a lower number of sequences in the photosynthesis subsystem. The apparent phosphorus limitation appears to influence the GB metagenomic signature of the three locations. Phosphorus is also one of the main factors determining changes in the abundance of planktonic vibrios, suggesting that nutrient limitation can be observed at community (metagenomic) and population levels (total prokaryote and vibrio counts). PMID:22363639

Insights to bioprocess and treatment competence of urban wetlands.

PubMed

Mahapatra, Durga Madhab; Joshi, N V; Ramachandra, T V

2018-01-15

Wetlands play a major role in the recharge of groundwater resources, maintenance of water quality (remediation), moderate microclimate while supporting local livelihood through provision of fish, fodder, etc. The present study aims to investigate algal-bacterial consortium as a function of residence time with the water quality dynamics in two major wetlands in Bangalore city, India. Over thirty-two genera of algae were recorded with more than 40 species in the lakes and two dominant bacterial assemblages. The higher Ammonium-N content favoured the growth of these members. Significant correlation was observed between the nutrient concentrations and the community structure at the inflows and the outflows. The algal community showed negative correlation to filterable COD and high nutrients levels while bacterial abundance was observed under high loadings. The green algae Chlorophyceae (Chlorella blooms), which are indicators of nutrient enrichment were observed predominantly, that needs an immediate attention. Higher overall treatment efficiency was observed in terms of CNP removal during the Pre-monsoon season attributed to absence of macrophytes cover and rapid growth of algal assemblage's due to higher temperature regimes with adequate solar insolation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Growth impacts of Saharan dust, mineral nutrients, and CO2 on a planktonic herbivore in southern Mediterranean lakes.

PubMed

Villar-Argaiz, Manuel; Cabrerizo, Marco J; González-Olalla, Juan Manuel; Valiñas, Macarena S; Rajic, Sanja; Carrillo, Presentación

2018-05-17

Rising levels of CO 2 can boost plant biomass but reduce its quality as a food source for herbivores. However, significant uncertainties remain as to the degree to which the effect is modulated by other environmental factors and the underlying processes causing these responses in nature. To address these questions, we carried out CO 2 -manipulation experiments using natural seston from three lakes under nutrient-enriched conditions (mimicking eutrophication and atmospheric dust-input processes) as a food source for the planktonic Daphnia pulicaria. Contrary to expectations, there were no single effects of rising CO 2 on herbivorous growth. Instead, synergistic CO 2  × nutrient interactions indicated that CO 2 did not support higher zooplankton growth rates unless supplemented with dust or inorganic nutrients (nitrogen, N; phosphorus, P) in two of three studied lakes. The overall positive correlation between zooplankton growth and seston carbon (C), but not seston C:P, suggested that this was a food quantity-mediated response. In addition, we found that this correlation improved when the data were grouped according to the nutrient treatments, and that the response was largest for dust. The synergistic CO 2  × nutrient effects reported here imply that the effects of rising CO 2 levels on herbivorous growth may be strongly influenced by eutrophication processes and the increase in dust deposition predicted for the Mediterranean region. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

PubMed

Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

2015-01-01

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

Algal biofuels from urban wastewaters: maximizing biomass yield using nutrients recycled from hydrothermal processing of biomass.

PubMed

Selvaratnam, T; Pegallapati, A K; Reddy, H; Kanapathipillai, N; Nirmalakhandan, N; Deng, S; Lammers, P J

2015-04-01

Recent studies have proposed algal cultivation in urban wastewaters for the dual purpose of waste treatment and bioenergy production from the resulting biomass. This study proposes an enhancement to this approach that integrates cultivation of an acidophilic strain, Galdieria sulphuraria 5587.1, in a closed photobioreactor (PBR); hydrothermal liquefaction (HTL) of the wet algal biomass; and recirculation of the nutrient-rich aqueous product (AP) of HTL to the PBR to achieve higher biomass productivity than that could be achieved with raw wastewater. The premise is that recycling nutrients in the AP can maintain optimal C, N and P levels in the PBR to maximize biomass growth to increase energy returns. Growth studies on the test species validated growth on AP derived from HTL at temperatures from 180 to 300°C. Doubling N and P concentrations over normal levels in wastewater resulted in biomass productivity gains of 20-25% while N and P removal rates also doubled. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nutrient effects of broodstocks on the larvae in Patinopecten yessoensis

NASA Astrophysics Data System (ADS)

Bai, Yucen; Zhang, Tao; Qiu, Tianlong; Gao, Yan; Zhang, Xiaofang

2015-07-01

Patinopecten yessoensis is a commercial valuable species. This study deals with the effect of nutrient effects of the broodstock (mainly ovaries) on the larvae. Concentrations of total carbohydrate, total protein and total lipid in the gonads of P. yessoensis from three Hatcheries (Hatchery 1, Hatchery 2, and Hatchery 3) were determined before and after spawning. The relationship between the nutrient concentration in ovaries before spawning (BC) and that of larvae (LC) was assessed as well as the change in nutrient levels in ovaries after spawning (DC). Results indicate that the BC of total carbohydrate (7.66%) and total lipid (14.48%) in ovaries were significantly higher than in testes (5.20%, 5.20% respectively), whereas the BC of total protein in the ovaries was lower (61.76%) than in the testes (81.67%). The different gonadal composition suggests the different nutrient demands between male and female broodstocks in breeding season. Patinopecten yessoensis gonads contained a higher proportion of lipids, in comparison to other bivalves, which might be a response to the low ambient water temperatures. Further analysis of fatty acids showed that the concentrations of n-3PUFA, EPA and DHA in larvae (LC) were positively correlated with BC and DC, indicating the significant nutrient influence of broodstocks on the larvae. As these fatty acids are important in metabolism, and have been demonstrated to be influential to the viability of the larvae, larval growth and the settlement, spat growth, and juvenile survival in many bivalves, they could possibly be used as indexes to evaluate, and predict condition of broodstocks and larvae.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivas-Ubach, A.; Sardans, J.; Hódar, J. A.

Plants respond locally and systemically to herbivore attack. Most of the research conducted on plant-herbivore relationships at elemental and molecular levels have focused on nutrients or/and certain molecular compounds or specific families of defensive metabolites showing that herbivores tend to select plant individuals or species with higher nutrient concentrations and to avoid those with higher levels of phenolics and terpenes. Unfortunately, the defensive role of phenolics in conifers is still unclear. We performed stoichiometric and metabolomics, local and systemic, analyses in two subspecies of Pinus sylvestris under the herbivorous attack by the caterpillars of the pine processionary moth, an importantmore » pest in the Mediterranean Basin. Herbivorous attack was not associated with any of the elements analyzed. Both pine subspecies responded locally to folivory mainly by increasing the concentrations of various terpenes and phenolics. Systemic responses differed between subspecies and most of the metabolites presented intermediate concentrations between those of the affected parts and unattacked trees. Contrary as usually thought, foliar nutrient concentrations did not show to be a main factor of an alleged plant selection by adult female processionary moths for oviposition. Local increases in phenolics were more associated with antioxidant function for protection against oxidative damage produced by folivory. On the other hand, terpenes were directly related to defense against herbivores. Herbivory attack produced a general systemic shift in pines, including both primary and secondary metabolisms, that was, however, less intense and chemically different from the local responses. Subspecies responded similarly locally but differently to folivory at systemic level.« less

Can upwelling signals be detected in intertidal fishes of different trophic levels?

PubMed

Pulgar, J; Poblete, E; Alvarez, M; Morales, J P; Aranda, B; Aldana, M; Pulgar, V M

2013-11-01

For intertidal fishes belonging to three species, the herbivore Scartichthys viridis (Blenniidae), the omnivore Girella laevifrons (Kyphosidae) and the carnivore Graus nigra (Kyphosidae), mass and body size relationships were higher in individuals from an upwelling zone compared with those from a non-upwelling zone. RNA:DNA were higher in the herbivores and omnivores from the upwelling zone. Higher biomass and RNA:DNA in the upwelling intertidal fishes may be a consequence of an increased exposure to higher nutrient availability, suggesting that increased physiological conditioning in vertebrates from upwelling areas can be detected and measured using intertidal fishes of different trophic levels. © 2013 The Fisheries Society of the British Isles.

Understanding food webs in the Chesapeake Bay

USGS Publications Warehouse

Keough, J.R.; Haramis, G.M.; Perry, M.C.; Perry, M.C.

2002-01-01

Approaches to predictive modeling and to management of the Chesapeake Bay ecosystem are 'bottom up' (i.e., approaches involve the control of nutrient inputs in attempts to manage plankton productivity) and 'top down' (i.e., approaches involve controls on harvest of fisheries and wildlife in attempts to manage vertebrate populations). Both approaches are limited by a lack of understanding of trophic connections between nutrient inputs, primary producers, and higher trophic level consumers. This project is aimed at identifying trophic structure for the submersed aquatic vegetation habitat of the Chesapeake Bay. We are employing analysis of stable isotope ratios of plant and animal tissues to identify trophic levels and traditional food habits analysis to identify the foods of a number of species of waterfowl.

The biogeochemical heterogeneity of tropical forests.

PubMed

Townsend, Alan R; Asner, Gregory P; Cleveland, Cory C

2008-08-01

Tropical forests are renowned for their biological diversity, but also harbor variable combinations of soil age, chemistry and susceptibility to erosion or tectonic uplift. Here we contend that the combined effects of this biotic and abiotic diversity promote exceptional biogeochemical heterogeneity at multiple scales. At local levels, high plant diversity creates variation in chemical and structural traits that affect plant production, decomposition and nutrient cycling. At regional levels, myriad combinations of soil age, soil chemistry and landscape dynamics create variation and uncertainty in limiting nutrients that do not exist at higher latitudes. The effects of such heterogeneity are not well captured in large-scale estimates of tropical ecosystem function, but we suggest new developments in remote sensing can help bridge the gap.

Nutrient Digestibility and Metabolizable Energy Content of Mucuna pruriens Whole Pods Fed to Growing Pelibuey Lambs.

PubMed

Loyra-Tzab, Enrique; Sarmiento-Franco, Luis Armando; Sandoval-Castro, Carlos Alfredo; Santos-Ricalde, Ronald Herve

2013-07-01

The nutrient digestibility, nitrogen balance and in vivo metabolizable energy supply of Mucuna pruriens whole pods fed to growing Pelibuey lambs was investigated. Eight Pelibuey sheep housed in metabolic crates were fed increasing levels of Mucuna pruriens pods: 0 (control), 100 (Mucuna100), 200 (Mucuna200) and 300 (Mucuna300) g/kg dry matter. A quadratic (p<0.002) effect was observed for dry matter (DM), neutral detergent fibre (aNDF), nitrogen (N) and gross energy (GE) intakes with higher intakes in the Mucuna100 and Mucuna200 treatments. Increasing M. pruriens in the diets had no effect (p>0.05) on DM and GE apparent digestibility (p<0.05). A linear reduction in N digestibility and N retention was observed with increasing mucuna pod level. This effect was accompanied by a quadratic effect (p<0.05) on fecal-N and N-balance which were higher in the Mucuna100 and Mucuna200 treatments. Urine-N excretion, GE retention and dietary estimated nutrient supply (metabolizable protein and metabolizable energy) were not affected (p>0.05). DM, N and GE apparent digestibility coefficient of M. pruriens whole pods obtained through multiple regression equations were 0.692, 0.457, 0.654 respectively. In vivo DE and ME content of mucuna whole pod were estimated in 11.0 and 9.7 MJ/kg DM. It was concluded that whole pods from M. pruriens did not affect nutrient utilization when included in an mixed diet up to 200 g/kg DM. This is the first in vivo estimation of mucuna whole pod ME value for ruminants.

Energy and nutrient density of foods in relation to their carbon footprint.

PubMed

Drewnowski, Adam; Rehm, Colin D; Martin, Agnes; Verger, Eric O; Voinnesson, Marc; Imbert, Philippe

2015-01-01

A carbon footprint is the sum of greenhouse gas emissions (GHGEs) associated with food production, processing, transporting, and retailing. We examined the relation between the energy and nutrient content of foods and associated GHGEs as expressed as g CO2 equivalents. GHGE values, which were calculated and provided by a French supermarket chain, were merged with the Composition Nutritionnelle des Aliments (French food-composition table) nutrient-composition data for 483 foods and beverages from the French Agency for Food, Environmental and Occupational Health and Safety. Foods were aggregated into 34 food categories and 5 major food groups as follows: meat and meat products, milk and dairy products, frozen and processed fruit and vegetables, grains, and sweets. Energy density was expressed as kcal/100 g. Nutrient density was determined by using 2 alternative nutrient-density scores, each based on the sum of the percentage of daily values for 6 or 15 nutrients, respectively. The energy and nutrient densities of foods were linked to log-transformed GHGE values expressed per 100 g or 100 kcal. Grains and sweets had lowest GHGEs (per 100 g and 100 kcal) but had high energy density and a low nutrient content. The more-nutrient-dense animal products, including meat and dairy, had higher GHGE values per 100 g but much lower values per 100 kcal. In general, a higher nutrient density of foods was associated with higher GHGEs per 100 kcal, although the slopes of fitted lines varied for meat and dairy compared with fats and sweets. Considerations of the environmental impact of foods need to be linked to concerns about nutrient density and health. The point at which the higher carbon footprint of some nutrient-dense foods is offset by their higher nutritional value is a priority area for additional research. © 2015 American Society for Nutrition.

Invasion Potential of Two Tropical Physalis Species in Arid and Semi-Arid Climates: Effect of Water-Salinity Stress and Soil Types on Growth and Fecundity.

PubMed

Ozaslan, Cumali; Farooq, Shahid; Onen, Huseyin; Bukun, Bekir; Ozcan, Selcuk; Gunal, Hikmet

2016-01-01

Invasive plants are recognized for their impressive abilities to withstand adverse environmental conditions however, all invaders do not express the similar abilities. Therefore, survival, growth, nutrient uptake and fecundity of two co-occurring, invasive Physalis species were tested under water and salinity stresses, and different soil textures in the current study. Five different water stress levels (100, 75, 50, 25, and 12.5% pot water contents), four different soil salinity levels (0, 3, 6, and 12 dSm-1) and four different soil textures (67% clay, 50% clay, silt clay loam and sandy loam) were included in three different pot experiments. Both weeds survived under all levels of water stress except 12.5% water contents and on all soil types however, behaved differently under increasing salinity. The weeds responded similarly to salinity up till 3 dSm-1 whereas, P. philadelphica survived for longer time than P. angulata under remaining salinity regimes. Water and salinity stress hampered the growth and fecundity of both weeds while, soil textures had slight effect. Both weeds preferred clay textured soils for better growth and nutrient uptake however, interactive effect of weeds and soil textures was non-significant. P. angulata accumulated higher K and Na while P. philadelphica accrued more Ca and Mg as well as maintained better K/Na ratio. P. angulata accumulated more Na and P under salinity stress while, P. philadelphica accrued higher K and Mg, and maintained higher K/Na ratio. Collectively, highest nutrient accumulation was observed under stress free conditions and on clay textured soils. P. philadelphica exhibited higher reproductive output under all experimental conditions than P. angulata. It is predicted that P. philadelphica will be more problematic under optimal water supply and high salinity while P. angulata can better adapt water limited environments. The results indicate that both weeds have considerable potential to further expand their ranges in semi-arid regions of Turkey.

Invasion Potential of Two Tropical Physalis Species in Arid and Semi-Arid Climates: Effect of Water-Salinity Stress and Soil Types on Growth and Fecundity

PubMed Central

Ozaslan, Cumali; Bukun, Bekir; Ozcan, Selcuk

2016-01-01

Invasive plants are recognized for their impressive abilities to withstand adverse environmental conditions however, all invaders do not express the similar abilities. Therefore, survival, growth, nutrient uptake and fecundity of two co-occurring, invasive Physalis species were tested under water and salinity stresses, and different soil textures in the current study. Five different water stress levels (100, 75, 50, 25, and 12.5% pot water contents), four different soil salinity levels (0, 3, 6, and 12 dSm-1) and four different soil textures (67% clay, 50% clay, silt clay loam and sandy loam) were included in three different pot experiments. Both weeds survived under all levels of water stress except 12.5% water contents and on all soil types however, behaved differently under increasing salinity. The weeds responded similarly to salinity up till 3 dSm-1 whereas, P. philadelphica survived for longer time than P. angulata under remaining salinity regimes. Water and salinity stress hampered the growth and fecundity of both weeds while, soil textures had slight effect. Both weeds preferred clay textured soils for better growth and nutrient uptake however, interactive effect of weeds and soil textures was non-significant. P. angulata accumulated higher K and Na while P. philadelphica accrued more Ca and Mg as well as maintained better K/Na ratio. P. angulata accumulated more Na and P under salinity stress while, P. philadelphica accrued higher K and Mg, and maintained higher K/Na ratio. Collectively, highest nutrient accumulation was observed under stress free conditions and on clay textured soils. P. philadelphica exhibited higher reproductive output under all experimental conditions than P. angulata. It is predicted that P. philadelphica will be more problematic under optimal water supply and high salinity while P. angulata can better adapt water limited environments. The results indicate that both weeds have considerable potential to further expand their ranges in semi-arid regions of Turkey. PMID:27741269

Recent insights into physiological responses to nutrients by the cylindrospermopsin producing cyanobacterium, Cylindrospermopsis raciborskii

NASA Astrophysics Data System (ADS)

Burford, Michele A.; Willis, Anusuya; Chuang, Ann; Man, Xiao; Orr, Phil

2017-11-01

The harmful cyanobacterium Cylindrospermopsis raciborskii is a widespread species increasingly being recorded in freshwater systems around the world. Studies have demonstrated some key attributes of this species which may explain its global dominance. It has a high level of flexibility with respect to light and nutrients, being capable of growth under low and variable light conditions. However, it is the strategy with respect to nutrient utilization that has received more attention. Unlike many bloom forming species, the dominance of this species is not simply linked to higher nutrient loads. In fact it appears that it is more competitive when phosphorus and nitrogen availability is low and/or variable. An important component of this flexibility appears to be the result of within-population strain variability in responses to nutrients, as well as key physiological adaptations. Strain variability also appears to have an effect on the population-level cell quota of toxins, specifically cylindrospermopsins (CYNs). Field studies in Australia showed that populations had the highest proportion of toxic strains when dissolved inorganic phosphorus was added, resulting in stoichiometrically balanced nitrogen and phosphorus within the cells. These strategies are part of an arsenal of responses to environmental conditions, making it a challenging species to manage. However, our ability to improve bloom prediction will rely on a more detailed understanding of the complex physiology and ecology of this species.

Relationship between nutrients and plankton biomass in the turbidity maximum zone of the Pearl River Estuary.

PubMed

Shi, Zhen; Xu, Jie; Huang, Xiaoping; Zhang, Xia; Jiang, Zhijian; Ye, Feng; Liang, Ximei

2017-07-01

Nutrients, dissolved and particulate organic carbon and plankton (bacterio-, phyto- and zoo-) were compared in the turbidity maximum zone (TMZ) and adjacent areas (non-TMZ) in the Pearl River estuary. Our results showed that high levels of suspended substances had marked effect on dynamics of nutrients and plankton in the TMZ. Based on the cluster analysis of total suspended solids (TSS) concentrations, all stations were divided into two groups, TMZ with average TSS of 171mg/L and non-TMZ of 45mg/L. Suspended substances adsorbed PO 4 3- and dissolved organic carbon, resulting in higher particulate phosphorus and organic carbon (POC) and lower PO 4 3- and DOC in the TMZ, compared to the non-TMZ. However, suspended substances had limited effect on nitrogenous nutrients. Phytoplankton growth was light-limited due to high concentrations of suspended substances in the TMZ and a peak of phytoplankton abundance appeared in the non-TMZ. In contrast, the highest bacterial abundance occurred in the TMZ, which was likely partly responsible for low DOC levels. Two peaks of zooplankton abundance observed in the TMZ and non-TMZ in the Pearl River estuary were primarily supported by bacteria and phytoplankton, respectively. Our finding implied that high levels of suspended solids in the TMZ affect the trophic balance. Copyright © 2016. Published by Elsevier B.V.

Soil nutrient availability and reproductive effort drive patterns in nutrient resorption in Pentachlethra macroloba

Treesearch

K. L. Tully; Tana Wood; A. M. Schwantes; D. Lawrence

2013-01-01

The removal of nutrients from senescing tissues, nutrient resorption, is a key strategy for conserving nutrients in plants. However, our understanding of what drives patterns of nutrient resorption in tropical trees is limited. We examined the effects of nutrient sources (stand-level and tree-level soil fertility) and sinks (reproductive effort) on nitrogen (N) and...

Nutrient Intakes Linked to Better Health Outcomes Are Associated with Higher Diet Costs in the US

PubMed Central

Aggarwal, Anju; Monsivais, Pablo; Drewnowski, Adam

2012-01-01

Purpose Degrees of nutrient intake and food groups have been linked to differential chronic disease risk. However, intakes of specific nutrients may also be associated with differential diet costs and unobserved differences in socioeconomic status (SES). The present study examined degrees of nutrient intake, for every key nutrient in the diet, in relation to diet cost and SES. Methods Socio-demographic data for a stratified random sample of adult respondents in the Seattle Obesity Study were obtained through telephone survey. Dietary intakes were assessed using food frequency questionnaire (FFQ) (n = 1,266). Following standard procedures, nutrient intakes were energy-adjusted using the residual method and converted into quintiles. Diet cost for each respondent was estimated using Seattle supermarket retail prices for 384 FFQ component foods. Results Higher intakes of dietary fiber, vitamins A, C, D, E, and B12, beta carotene, folate, iron, calcium, potassium, and magnesium were associated with higher diet costs. The cost gradient was most pronounced for vitamin C, beta carotene, potassium, and magnesium. Higher intakes of saturated fats, trans fats and added sugars were associated with lower diet costs. Lower cost lower quality diets were more likely to be consumed by lower SES. Conclusion Nutrients commonly associated with a lower risk of chronic disease were associated with higher diet costs. By contrast, nutrients associated with higher disease risk were associated with lower diet costs. The cost variable may help somewhat explain why lower income groups fail to comply with dietary guidelines and have highest rates of diet related chronic disease. PMID:22662168

Contribution of Dietary Supplements to Nutritional Adequacy by Socioeconomic Subgroups in Adults of the United States.

PubMed

Blumberg, Jeffrey B; Frei, Balz; Fulgoni, Victor L; Weaver, Connie M; Zeisel, Steven H

2017-12-22

Many Americans have inadequate intakes of several nutrients, and the Dietary Guidelines for Americans 2015-2020 identified vitamins A, C, D, and E, in addition to calcium, magnesium, iron, potassium, choline, and fiber as "underconsumed nutrients". Based on nationally representative data on 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009-2012, assessments were made of socioeconomic differences, based on the Poverty Income Ratio (PIR), in terms of the association of dietary supplement use on nutrient intake and nutrient inadequacies. Compared to food alone, the use of any dietary supplement plus food was associated with significantly ( p < 0.01) higher intakes of 15-16 of 19 nutrients examined in all socioeconomic groups; and significantly reduced rates of inadequacy for 10/17 nutrients in the subgroup PIR > 1.85 (not poor), but only 4-5/17 nutrients (calcium and vitamins A, C, D, E) for the poor and nearly poor subgroups (PIR < 1.35 and PIR 1.35 to ≤1.85, respectively). An increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 3-9/13 nutrients, but all were less than 5% in the PIR subgroups. In conclusion, dietary supplement use was associated with an increased micronutrient intake, decreased inadequacies, and a slight increase in the prevalence of intakes above the UL, with greater benefits seen in the PIR > 1.85 subgroup.

Bioaccessible nutrients and bioactive components from fortified products prepared using finger millet (Eleusine coracana).

PubMed

Oghbaei, Morteza; Prakash, Jamuna

2012-08-30

Finger millet (Eleusine coracana), a staple food in semi-arid parts of the world, is a rich source of nutrients and bioactive components comparable to rice and wheat but with higher fibre content. Unprocessed and processed finger millet (whole flour (WFM), sieved flour (SFM), wafers and vermicelli with altered matrices (added Fe or Zn or reduced fibre)) were analysed for chemical composition, bioaccessible Fe, Zn and Ca, in vitro digestible starch (IVSD) and protein (IVPD) and bioactive components (polyphenols and flavonoids). WFM and SFM flours differed significantly in their composition. Sieving decreased the content of both nutrients and antinutrients in WFM but increased their digestibility/bioaccessibility. WFM products with Zn and Fe showed highest IVPD, whereas SFM products with Fe showed highest IVSD. Products with externally added Fe and Zn showed maximum bioaccessibility of Fe and Zn respectively. WFM had the highest levels of total polyphenols and flavonoids, 4.18 and 15.85 g kg⁻¹ respectively; however, bioaccessibility was highest in SFM vermicelli. The availability of nutrients and bioactive components was influenced by both processing methods and compositional alterations of the food matrix in finger millet products, and bioaccessibility of all constituents was higher in vermicelli (wet matrix) than in wafers (dry matrix). Copyright © 2012 Society of Chemical Industry.

Coupled impacts of climate and land use change across a river-lake continuum: insights from an integrated assessment model of Lake Champlain’s Missisquoi Basin, 2000-2040

NASA Astrophysics Data System (ADS)

Zia, Asim; Bomblies, Arne; Schroth, Andrew W.; Koliba, Christopher; Isles, Peter D. F.; Tsai, Yushiou; Mohammed, Ibrahim N.; Bucini, Gabriela; Clemins, Patrick J.; Turnbull, Scott; Rodgers, Morgan; Hamed, Ahmed; Beckage, Brian; Winter, Jonathan; Adair, Carol; Galford, Gillian L.; Rizzo, Donna; Van Houten, Judith

2016-11-01

Global climate change (GCC) is projected to bring higher-intensity precipitation and higher-variability temperature regimes to the Northeastern United States. The interactive effects of GCC with anthropogenic land use and land cover changes (LULCCs) are unknown for watershed level hydrological dynamics and nutrient fluxes to freshwater lakes. Increased nutrient fluxes can promote harmful algal blooms, also exacerbated by warmer water temperatures due to GCC. To address the complex interactions of climate, land and humans, we developed a cascading integrated assessment model to test the impacts of GCC and LULCC on the hydrological regime, water temperature, water quality, bloom duration and severity through 2040 in transnational Lake Champlain’s Missisquoi Bay. Temperature and precipitation inputs were statistically downscaled from four global circulation models (GCMs) for three Representative Concentration Pathways. An agent-based model was used to generate four LULCC scenarios. Combined climate and LULCC scenarios drove a distributed hydrological model to estimate river discharge and nutrient input to the lake. Lake nutrient dynamics were simulated with a 3D hydrodynamic-biogeochemical model. We find accelerated GCC could drastically limit land management options to maintain water quality, but the nature and severity of this impact varies dramatically by GCM and GCC scenario.

Ceramic Hollow Fibre Constructs for Continuous Perfusion and Cell Harvest from 3D Hematopoietic Organoids

PubMed Central

Tahlawi, Asma; Li, Kang

2018-01-01

Tissue vasculature efficiently distributes nutrients, removes metabolites, and possesses selective cellular permeability for tissue growth and function. Engineered tissue models have been limited by small volumes, low cell densities, and invasive cell extraction due to ineffective nutrient diffusion and cell-biomaterial attachment. Herein, we describe the fabrication and testing of ceramic hollow fibre membranes (HFs) able to separate red blood cells (RBCs) and mononuclear cells (MNCs) and be incorporated into 3D tissue models to improve nutrient and metabolite exchange. These HFs filtered RBCs from human umbilical cord blood (CB) suspensions of 20% RBCs to produce 90% RBC filtrate suspensions. When incorporated within 5 mL of 3D collagen-coated polyurethane porous scaffold, medium-perfused HFs maintained nontoxic glucose, lactate, pH levels, and higher cell densities over 21 days of culture in comparison to nonperfused 0.125 mL scaffolds. This hollow fibre bioreactor (HFBR) required a smaller per-cell medium requirement and operated at cell densities > 10-fold higher than current 2D methods whilst allowing for continuous cell harvest through HFs. Herein, we propose HFs to improve 3D cell culture nutrient and metabolite diffusion, increase culture volume and cell density, and continuously harvest products for translational cell therapy biomanufacturing protocols. PMID:29760729

Intra-Household Allocation of Nutrients in an Opening China.

PubMed

Zhou, Li; Chen, Xiaohong; Lei, Lei

2018-04-09

This paper uses China Health and Nutrition Survey (CHNS) data to analyze the effect of foreign direct investment (FDI) on nutrient intakes across various family roles to identify the different family roles' heterogeneous nutrition intake responses to economic openness. The empirical evidence shows that FDI enhances labor forces' calorie intake significantly, especially for rural households. The government should continue facilitating more FDI inflows, especially FDI in secondary industries for rural populations. However, the larger the family, the smaller the effect of FDI on nutrient intake for some family roles. The elderly and children may be weaker responders on nutrient intake than other family members in an open economy. This implies the existence of intra-household redistribution and that the level of effectiveness will decrease with family size. The results suggest that family members in rural areas can benefit more in terms of nutrient intake. Our empirical evidence also indicates that female family members' calorie intake from the FDI effect is higher than that of male family members (except for the granddaughter/grandson). Preferential policies should be provided for the FDI, flowing to rural areas and female dominant industries.

Intra-Household Allocation of Nutrients in an Opening China

PubMed Central

Zhou, Li; Chen, Xiaohong; Lei, Lei

2018-01-01

This paper uses China Health and Nutrition Survey (CHNS) data to analyze the effect of foreign direct investment (FDI) on nutrient intakes across various family roles to identify the different family roles’ heterogeneous nutrition intake responses to economic openness. The empirical evidence shows that FDI enhances labor forces’ calorie intake significantly, especially for rural households. The government should continue facilitating more FDI inflows, especially FDI in secondary industries for rural populations. However, the larger the family, the smaller the effect of FDI on nutrient intake for some family roles. The elderly and children may be weaker responders on nutrient intake than other family members in an open economy. This implies the existence of intra-household redistribution and that the level of effectiveness will decrease with family size. The results suggest that family members in rural areas can benefit more in terms of nutrient intake. Our empirical evidence also indicates that female family members’ calorie intake from the FDI effect is higher than that of male family members (except for the granddaughter/grandson). Preferential policies should be provided for the FDI, flowing to rural areas and female dominant industries. PMID:29642513

Socioeconomic Indicators Are Independently Associated with Nutrient Intake in French Adults: A DEDIPAC Study

PubMed Central

Si Hassen, Wendy; Castetbon, Katia; Cardon, Philippe; Enaux, Christophe; Nicolaou, Mary; Lien, Nanna; Terragni, Laura; Holdsworth, Michelle; Stronks, Karien; Hercberg, Serge; Méjean, Caroline

2016-01-01

Studies have suggested differential associations of specific indicators of socioeconomic position (SEP) with nutrient intake and a cumulative effect of these indicators on diet. We investigated the independent association of SEP indicators (education, income, occupation) with nutrient intake and their effect modification. This cross-sectional analysis included 91,900 French adults from the NutriNet-Santé cohort. Nutrient intake was estimated using three 24-h records. We investigated associations between the three SEP factors and nutrient intake using sex-stratified analysis of covariance, adjusted for age and energy intake, and associations between income and nutrient intake stratified by education and occupation. Low educated participants had higher protein and cholesterol intakes and lower fibre, vitamin C and beta-carotene intakes. Low income individuals had higher complex carbohydrate intakes, and lower magnesium, potassium, folate and vitamin C intakes. Intakes of vitamin D and alcohol were lower in low occupation individuals. Higher income was associated with higher intakes of fibre, protein, magnesium, potassium, beta-carotene, and folate among low educated persons only, highlighting effect modification. Lower SEP, particularly low education, was associated with lower intakes of nutrients required for a healthy diet. Each SEP indicator was associated with specific differences in nutrient intake suggesting that they underpin different social processes. PMID:26978393

Socioeconomic Indicators Are Independently Associated with Nutrient Intake in French Adults: A DEDIPAC Study.

PubMed

Si Hassen, Wendy; Castetbon, Katia; Cardon, Philippe; Enaux, Christophe; Nicolaou, Mary; Lien, Nanna; Terragni, Laura; Holdsworth, Michelle; Stronks, Karien; Hercberg, Serge; Méjean, Caroline

2016-03-10

Studies have suggested differential associations of specific indicators of socioeconomic position (SEP) with nutrient intake and a cumulative effect of these indicators on diet. We investigated the independent association of SEP indicators (education, income, occupation) with nutrient intake and their effect modification. This cross-sectional analysis included 91,900 French adults from the NutriNet-Santé cohort. Nutrient intake was estimated using three 24-h records. We investigated associations between the three SEP factors and nutrient intake using sex-stratified analysis of covariance, adjusted for age and energy intake, and associations between income and nutrient intake stratified by education and occupation. Low educated participants had higher protein and cholesterol intakes and lower fibre, vitamin C and beta-carotene intakes. Low income individuals had higher complex carbohydrate intakes, and lower magnesium, potassium, folate and vitamin C intakes. Intakes of vitamin D and alcohol were lower in low occupation individuals. Higher income was associated with higher intakes of fibre, protein, magnesium, potassium, beta-carotene, and folate among low educated persons only, highlighting effect modification. Lower SEP, particularly low education, was associated with lower intakes of nutrients required for a healthy diet. Each SEP indicator was associated with specific differences in nutrient intake suggesting that they underpin different social processes.

Effect of cadmium accumulation on mineral nutrient levels in vegetable crops: potential implications for human health.

PubMed

Yang, Danping; Guo, Zhiqiang; Green, Iain D; Xie, Deti

2016-10-01

Consumption of vegetables is often the predominant route whereby humans are exposed to the toxic metal Cd. Health impacts arising from Cd consumption may be influenced by changes in the mineral nutrient content of vegetables, which may occur when plants are exposed to Cd. Here, we subjected model root (carrot) and leaf (lettuce) vegetables to soil Cd concentrations of 0.3, 1.5, 3.3, and 9.6 μg g(-1) for 10 weeks to investigate the effect of Cd exposure on Cd accumulation, growth performance, and mineral nutrient homeostasis. The findings demonstrated that Cd accumulation in lettuce (20.1-71.5 μg g(-1)) was higher than that in carrot (3.2-27.5 μg g(-1)), and accumulation exceeded the maximum permissible Cd concentration in vegetables when soil contained more than 3.3 μg g(-1) of Cd. There was a marked hormetic effect on carrot growth at a soil Cd concentration of 3.3 μg g(-1), but increasing the Cd concentration to 9.6 μg g(-1) caused decreased growth in both crops. Additionally, in most cases, there was a positive correlation between Cd and the mineral nutrient content of vegetables, which was due to physiological changes in the plants causing increased uptake and/or translocation. This may suggest a general mechanism whereby the plant compensated for disrupted mineral nutrient metabolism by increasing nutrient supply to its tissues. Increased nutrient levels could potentially offset some risks posed to humans by increased Cd levels in crops, and we therefore suggest that changes in mineral nutrient levels should be included more widely in the risk assessment of potentially toxic metal contamination. Graphical abstract The Cd concentration (μg g-1 in dry matter) in the root, shoot and translocation factor (TF) of Cd from root to shoot in the carrot and lettuce, and the percentage of root Cd to the gross Cd contents (%) in carrot (C) and lettuce (D) exposed to soil Cd (0 (control), 1, 3, and 9 μg g-1) for 70 days. Values are means ± SD (n = 5).

The Influence of Shredder Feeding on Fungal Activity in a Nutrient-Enriched Stream and an Unaltered Stream

NASA Astrophysics Data System (ADS)

Chung, N.; Suberkopp, K.

2005-05-01

The effect of shredder feeding on aquatic hyphomycete communities associated with submerged leaves was studied in two southern Appalachian headwater streams in North Carolina. Coarse and fine mesh litter bags containing red maple (Acer rubrum) leaves were placed in the nutrient-enriched stream and in the reference stream and were retrieved monthly. Both shredder feeding and nutrient enrichment enhanced breakdown rates. The breakdown rates of leaves in coarse mesh bags in the reference stream (k = 0.0275) and fine mesh bags in the nutrient enriched stream (k = 0.0272) were not significantly different, suggesting that the shredding effect on litter breakdown was offset by higher fungal activity as a result of nutrient enrichment. Fungal sporulation rates and biomass (based on ergosterol concentrations) were higher in the nutrient enriched than in the reference stream, but neither fungal biomass nor sporulation rate was affected by shredder feeding. Species richness was higher in the nutrient-enriched than in the reference stream. The enrichment with nutrients altered fungal community composition more than shredder feeding.

Impacts of post-harvest slash and live-tree retention on biomass and nutrient stocks in Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

USGS Publications Warehouse

Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.

2013-01-01

Globally, there is widespread interest in using forest-derived biomass as a source of bioenergy. While conventional timber harvesting generally removes only merchantable tree boles, harvesting biomass feedstock can remove all forms of woody biomass (i.e., live and dead standing woody vegetation, downed woody debris, and stumps) resulting in a greater loss of biomass and nutrients as well as more severe habitat alteration. To investigate the potential impacts of this practice, this study examined the initial impacts (pre- and post-harvest) of various levels of slash and live-tree retention on biomass and nutrient stocks, including carbon (C), nitrogen (N), calcium (Ca), potassium (K), and phosphorus (P), in Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Treatments examined included three levels of slash retention, whole-tree harvest (WTH), 20% slash retention (20SR), and stem-only harvest (SOH), factored with three levels of green-tree retention, no trees retained (NONE), dispersed retention (DISP), and aggregate retention (AGR). Slash retention was the primary factor affecting post-harvest biomass and nutrient stocks, including woody debris pools. Compared to the unharvested control, stocks of biomass, carbon, and nutrients, including N, Ca, K, and P, in woody debris were higher in all treatments. Stem-only harvests typically contained greater biomass and nutrient stocks than WTH, although biomass and nutrients within 20SR, a level recommended by biomass harvesting guidelines in the US and worldwide, generally did not differ from WTH or SOH. Biomass in smaller-diameter slash material (typically 2.5-22.5 cm in diameter) dominated the woody debris pool following harvest regardless of slash retention level. Trends among treatments in this diameter range were generally similar to those in the total woody debris pool. Specifically, SOH contained significantly greater amounts of biomass than WTH while 20SR was not different from either WTH or SOH. Within P. tremuloides systems, we observed high stocks of smaller diameter slash material for all prescribed slash retention treatments. Most notably, WTH retains much more material than anticipated, up to 50% of available slash. These results reflect the high levels of breakage during winter harvest operations in these stands and, consequently, warrant consideration when anticipating the impacts of biomass harvesting on woody debris pools. Further investigation is necessary to understand how deliberate slash retention levels and season-of-harvest impact woody debris in other forest systems.

Human waste: An underestimated source of nutrient pollution in coastal seas of Bangladesh, India and Pakistan.

PubMed

Amin, Md Nurul; Kroeze, Carolien; Strokal, Maryna

2017-05-15

Many people practice open defecation in south Asia. As a result, lot of human waste containing nutrients such as nitrogen (N) and phosphorus (P) enter rivers. Rivers transport these nutrients to coastal waters, resulting in marine pollution. This source of nutrient pollution is, however, ignored in many nutrient models. We quantify nutrient export by large rivers to coastal seas of Bangladesh, India and Pakistan, and the associated eutrophication potential in 2000 and 2050. Our new estimates for N and P inputs from human waste are one to two orders of magnitude higher than earlier model calculations. This leads to higher river export of nutrients to coastal seas, increasing the risk of coastal eutrophication potential (ICEP). The newly calculated future ICEP, for instance, Godavori river is 3 times higher than according to earlier studies. Our modeling approach is simple and transparent and can easily be applied to other data-poor basins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of feeding sorghum straw based complete rations with different roughage to concentrate ratio on dry matter intake, nutrient utilization, and nitrogen balance in Nellore ram lambs.

PubMed

Malisetty, Venkateswarlu; Yerradoddi, Ramana Reddy; Devanaboina, Nagalakshmi; Mallam, Mahender; Mitta, Pavani

2014-06-01

An experiment was conducted by feeding sorghum straw (Sorghum bicolor) based complete rations at roughage concentrate ratio 70:30 (CR-I), 60:40 (CR-II), 50:50 (CR-III), and 40:60 (CR-IV) for 180 days to find out suitable ratio of sorghum straw in the complete ration (mash form) on nutrient utilization and nitrogen balance in Nellore ram lambs. The DMI (g/day) increased significantly (P < 0.05) as level of concentrate increased in complete rations. No significant difference was found in digestibilities of proximate nutrients. However, CP digestibility was higher either significantly or nonsignificantly by 2.12, 5.50, and 9.36 %, respectively, in lambs fed with CR-II (P > 0.05), CR-III (P > 0.05), and CR-IV (P < 0.05) rations in comparison to lambs fed with CR-I ration. Furthermore, CP digestibility was higher by 7.09 and 3.66 % in lambs fed with CR-IV ration than those fed with CR-II (P < 0.05) and CR-III (P > 0.05) ration. The average CWC digestibility coefficients were comparable among four rations. The N intake (g/day) was significantly (P < 0.01) different and progressively increased by 31.46, 48.69, and 82.86 % in ram lambs fed with CR-II, CR-III, and CR-IV rations, respectively, in comparison to CR-I ration. The N balance (g/day) was higher either significantly or nonsignificantly by 34.46 (P > 0.05), 133.46 (P < 0.01), and 198.87 % (P < 0.01) with CR-II, CR-III, and CR-IV rations, respectively, in comparison to CR-I ration. Based on results, it is inferred that the level of sorghum straw in complete ration had no effect on digestibility of nutrients barring crude protein in Nellore ram lambs.

Effects of inclusion level on nutrient digestibility and energy content of wheat middlings and soya bean meal for growing pigs.

PubMed

Huang, Qiang; Piao, Xiangshu; Liu, Ling; Li, Defa

2013-01-01

Two experiments were conducted to determine the effects of inclusion level of wheat middlings and soya bean meal on apparent total tract digestibility (ATTD) of energy and chemical components of these ingredients in growing pigs. Furthermore, the effects of the inclusion level on their contents of digestible energy (DE) and metabolisable energy (ME) were also determined by the difference method. In Experiment 1, six diets were fed to 36 growing pigs according to a completely randomised design. The basal diet was a corn-soya bean meal diet while the other five diets contained 9.6%, 19.2%, 28.8%, 38.4% or 48.0% of wheat middlings added at the expense of corn and soya bean meal. The measured digestibility of energy and most nutrients of wheat middlings increased (p < 0.05) with increasing levels of that ingredient. Equations were obtained to predict digestibility by inclusion level. At an inclusion level of 9.6% wheat middlings, their DE contents were significantly lower (8.9 MJ/kg DM) than for the higher levels (10.7 to 11.9 MJ/kg DM, p < 0.01). In Experiment 2, three diets were fed to 18 growing pigs according to a completely randomised block design. The basal diet was a corn-based diet while the other two diets were based on corn and two levels of soya bean meal (22.2% and 33.6%). The content of DE in soya bean meal did not differ at 22.2% and 33.6% inclusion levels (16.2 and 16.3 MJ/kg DM, respectively), but the digestibility of dry matter (DM), organic matter and carbohydrates was increased at a higher inclusion level (p < 0.05). This study revealed that the estimated digestibility of nutrients from soya bean meal and wheat middlings was affected by their dietary inclusion levels. For soya bean meal, the estimated energy contents was independent of its inclusion level, but not for wheat middlings. Therefore, the inclusion level of wheat middlings has to be considered for estimating their energy value.

Low-level arsenic exposure: nutritional and dietary predictors in first-grade Uruguayan children

PubMed Central

Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

2016-01-01

Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5–8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-hour dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9 µg/L) and household water (water As: median 0.45 µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on ”nutrient dense” dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity. PMID:26828624

Low-level arsenic exposure: Nutritional and dietary predictors in first-grade Uruguayan children.

PubMed

Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

2016-05-01

Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5-8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-h dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9µg/L) and household water (water As: median 0.45µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on "nutrient dense" dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Socioeconomic differences in purchases of more vs. less healthy foods and beverages: Analysis of over 25,000 British households in 2010☆

PubMed Central

Pechey, Rachel; Jebb, Susan A.; Kelly, Michael P.; Almiron-Roig, Eva; Conde, Susana; Nakamura, Ryota; Shemilt, Ian; Suhrcke, Marc; Marteau, Theresa M.

2013-01-01

Socioeconomic inequalities in diet-related health outcomes are well-recognised, but are not fully explained by observational studies of consumption. We provide a novel analysis to identify purchasing patterns more precisely, based on data for take-home food and beverage purchases from 25,674 British households in 2010. To examine socioeconomic differences (measured by occupation), we conducted regression analyses on the proportion of energy purchased from (a) each of 43 food or beverage categories and (b) major nutrients. Results showed numerous small category-level socioeconomic differences. Aggregation of the categories showed lower SES groups generally purchased a greater proportion of energy from less healthy foods and beverages than those in higher SES groups (65% and 60%, respectively), while higher SES groups purchased a greater proportion of energy from healthier food and beverages (28% vs. 24%). At the nutrient-level, socioeconomic differences were less marked, although higher SES was associated with purchasing greater proportions of fibre, protein and total sugars, and smaller proportions of sodium. The observed pattern of purchasing across SES groups contributes to the explanation of observed health differences between groups and highlights targets for interventions to reduce health inequalities. PMID:23849275

Consumption of ready-to-eat cereals (RTEC) among Malaysian children and association with socio-demographics and nutrient intakes – findings from the MyBreakfast study

PubMed Central

Mohd Nasir, Mohd Taib; Nurliyana, Abdul Razak; Norimah, A. Karim; Jan Mohamed, Hamid Jan B.; Tan, Sue Yee; Appukutty, Mahenderan; Hopkins, Sinead; Thielecke, Frank; Ong, Moi Kim; Ning, Celia; Tee, E. Siong

2017-01-01

ABSTRACT Background: The association between different types of breakfast meals and nutrient intakes has been studied to a lesser extent. Objective: This study compared nutrient intakes at breakfast and throughout the day between Malaysian children who consumed ready-to-eat cereals (RTEC) and those who did not. Methods: Anthropometric and dietary data for 1955 children aged 6–12 years from the MyBreakfast study were used in the analysis. Results: Overall, 18% of the children consumed RTEC at breakfast on at least one of the recall days. RTEC consumption was associated with younger age, urban areas, higher income and education level of parents. Among consumers, RTEC contributed 10% and 15% to daily intakes of calcium and iron respectively and ≥20% to daily intakes of vitamin C, thiamin, riboflavin and niacin. RTEC consumers had significantly higher mean intakes of vitamin C, thiamin, riboflavin, niacin, calcium, iron and sugar but lower intakes of fat and sodium than non-RTEC consumers at breakfast and for the total day. Conclusion: Consumption of fortified RTEC at breakfast was associated with lower fat and sodium intakes and higher intakes of several micronutrients both at breakfast and for the total day. However, total sugar intakes appeared to be higher. PMID:28469545

A Nutritional Profile of the Trap-Nesting Wasp Trypoxylon lactitarse (Hymenoptera: Crabronidae): Comparison of Sexes and Overwintering and Non-Overwintering Generations

PubMed Central

Judd, Timothy M.; Fasnacht, Matthew P.

2017-01-01

The wasp Trypoxylon lactitarse Saussure is a bivoltine trap-nesting species that possesses a non-overwintering generation (G1) and a generation that overwinters as a prepupa (G2). Thus, the nutritional needs of the G1 individuals were predicted to be different than the G2 because the latter generation needs to store energy prior to diapause. Trap-nesting Trypoxylon are also of interest because, unlike most Hymenoptera, the males guard the nest while females forage. Thus, males may lose nutrients as they stay and guard the nest. In this study, a nutritional profile was created for T. lactitarse to compare the macronutrient (protein, carbohydrates, and lipids) and micronutrient (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn) levels of the different life stages of the wasp and compare individuals of the G1 and G2 generations. There were distinct changes in the nutrient levels relative to the original food source as individuals metamorphosed into larvae, pupae, and adults. G1 larvae had higher levels of carbohydrates than G2 larvae. G2 larvae had higher levels of lipids and K than G1 larvae, indicating possible differences in energy storage. In adults, there was an increase in levels of carbohydrates and Mn. Parental males, which stay and guard the nest, were found to have higher levels of carbohydrates at the end of the nesting period than females and emerging adults. One possible implication is that females may feed males during the nesting period, as the females are the only individuals to forage. PMID:28054943

A Nutritional Profile of the Trap-Nesting Wasp Trypoxylon lactitarse (Hymenoptera: Crabronidae): Comparison of Sexes and Overwintering and Non-Overwintering Generations.

PubMed

Judd, Timothy M; Fasnacht, Matthew P

2017-01-03

The wasp Trypoxylon lactitarse Saussure is a bivoltine trap-nesting species that possesses a non-overwintering generation (G1) and a generation that overwinters as a prepupa (G2). Thus, the nutritional needs of the G1 individuals were predicted to be different than the G2 because the latter generation needs to store energy prior to diapause. Trap-nesting Trypoxylon are also of interest because, unlike most Hymenoptera, the males guard the nest while females forage. Thus, males may lose nutrients as they stay and guard the nest. In this study, a nutritional profile was created for T. lactitarse to compare the macronutrient (protein, carbohydrates, and lipids) and micronutrient (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn) levels of the different life stages of the wasp and compare individuals of the G1 and G2 generations. There were distinct changes in the nutrient levels relative to the original food source as individuals metamorphosed into larvae, pupae, and adults. G1 larvae had higher levels of carbohydrates than G2 larvae. G2 larvae had higher levels of lipids and K than G1 larvae, indicating possible differences in energy storage. In adults, there was an increase in levels of carbohydrates and Mn. Parental males, which stay and guard the nest, were found to have higher levels of carbohydrates at the end of the nesting period than females and emerging adults. One possible implication is that females may feed males during the nesting period, as the females are the only individuals to forage.

Advancing Analysis of Spatio-Temporal Variations of Soil Nutrients in the Water Level Fluctuation Zone of China’s Three Gorges Reservoir Using Self-Organizing Map

PubMed Central

Ye, Chen; Li, Siyue; Yang, Yuyi; Shu, Xiao; Zhang, Jiaquan; Zhang, Quanfa

2015-01-01

The ~350 km2 water level fluctuation zone (WLFZ) in the Three Gorges Reservoir (TGR) of China, situated at the intersection of terrestrial and aquatic ecosystems, experiences a great hydrological change with prolonged winter inundation. Soil samples were collected in 12 sites pre- (September 2008) and post submergence (June 2009) in the WLFZ and analyzed for soil nutrients. Self-organizing map (SOM) and statistical analysis including multi-way ANOVA, paired-T test, and stepwise least squares multiple regression were employed to determine the spatio-temporal variations of soil nutrients in relation to submergence, and their correlations with soil physical characteristics. Results showed significant spatial variability in nutrients along ~600 km long shoreline of the TGR before and after submergence. There were higher contents of organic matter, total nitrogen (TN), and nitrate (NO3-) in the lower reach and total phosphorus (TP) in the upper reach that were primarily due to the spatial variations in soil particle size composition and anthropogenic activities. Submergence enhanced soil available potassium (K), while significantly decreased soil N, possibly due to the alterations of soil particle size composition and increase in soil pH. In addition, SOM analysis determined important roles of soil pH value, bulk density, soil particle size (i.e., silt and sand) and nutrients (TP, TK, and AK) on the spatial and temporal variations in soil quality. Our results suggest that urban sewage and agricultural runoffs are primary pollutants that affect soil nutrients in the WLFZ of TGR. PMID:25789612

Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

PubMed

Tromboni, F; Dodds, W K

2017-07-01

Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

Vegetation composition, nutrient, and sediment dynamics along a floodplain landscape

USGS Publications Warehouse

Rybicki, Nancy B.; Noe, Gregory; Hupp, Cliff R.; Robinson, Myles

2015-01-01

Forested floodplains are important landscape features for retaining river nutrients and sediment loads but there is uncertainty in how vegetation influences nutrient and sediment retention. In order to understand the role of vegetation in nutrient and sediment trapping, we quantified species composition and the uptake of nutrients in plant material relative to landscape position and ecosystem attributes in an urban, Piedmont watershed in Virginia, USA. We investigated in situ interactions among vegetative composition, abundance, carbon (C), nitrogen (N) and phosphorus (P) fluxes and ecosystem attributes such as water level, shading, soil nutrient mineralization, and sediment deposition. This study revealed strong associations between vegetation and nutrient and sediment cycling processes at the plot scale and in the longitudinal dimension, but there were few strong patterns between these aspects at the scale of geomorphic features (levee, backswamp, and toe-slope). Patterns reflected the nature of the valley setting rather than a simple downstream continuum. Plant nutrient uptake and sediment trapping were greatest at downstream sites with the widest floodplain and lowest gradient where the hydrologic connection between the floodplain and stream is greater. Sediment trapping increased in association with higher herbaceous plant coverage and lower tree canopy density that, in turn, was associated with a more water tolerant tree community found in the lower watershed but not at the most downstream site in the watershed. Despite urbanization effects on the hydrology, this floodplain functioned as an efficient nutrient trap. N and P flux rates of herbaceous biomass and total litterfall more than accounted for the N and P mineralization flux rate, indicating that vegetation incorporated nearly all mineralized nutrients into biomass.

Insight into litter decomposition driven by nutrient demands of symbiosis system through the hypha bridge of arbuscular mycorrhizal fungi.

PubMed

Kong, Xiangshi; Jia, Yanyan; Song, Fuqiang; Tian, Kai; Lin, Hong; Bei, Zhanlin; Jia, Xiuqin; Yao, Bei; Guo, Peng; Tian, Xingjun

2018-02-01

Arbuscular mycorrhizal fungi (AMF) play an important role in litter decomposition. This study investigated how soil nutrient level affected the process. Results showed that AMF colonization had no significant effect on litter decomposition under normal soil nutrient conditions. However, litter decomposition was accelerated significantly under lower nutrient conditions. Soil microbial biomass in decomposition system was significantly increased. Especially, in moderate lower nutrient treatment (condition of half-normal soil nutrient), litters exhibited the highest decomposition rate, AMF hypha revealed the greatest density, and enzymes (especially nitrate reductase) showed the highest activities as well. Meanwhile, the immobilization of nitrogen (N) in the decomposing litter remarkably decreased. Our results suggested that the roles AMF played in ecosystem were largely affected by soil nutrient levels. At normal soil nutrient level, AMF exhibited limited effects in promoting decomposition. When soil nutrient level decreased, the promoting effect of AMF on litter decomposition began to appear, especially on N mobilization. However, under extremely low nutrient conditions, AMF showed less influence on decomposition and may even compete with decomposer microorganisms for nutrients.

Folate and nutrients involved in the 1-carbon cycle in the pretreatment of patients for colorectal cancer.

PubMed

Ferrari, Ariana; de Carvalho, Aline Martins; Steluti, Josiane; Teixeira, Juliana; Marchioni, Dirce Maria Lobo; Aguiar, Samuel

2015-06-02

To assess the ingestion of folate and nutrients involved in the 1-carbon cycle in non-treated patients with colorectal adenocarcinoma in a reference center for oncology in southeastern Brazil. In total, 195 new cases with colorectal adenocarcinoma completed a clinical evaluation questionnaire and a Food Frequency Questionnaire (FFQ). Blood samples from 161 patients were drawn for the assessment of serum folate. A moderate correlation was found between serum concentrations of folate, folate intake and the dietary folate equivalent (DFE) of synthetic supplements. Mulatto or black male patients with a primary educational level had a higher intake of dietary folate. Of patients obtaining folate from the diet alone or from dietary supplements, 11.00% and 0.10%, respectively, had intake below the recommended level. Of the patients using dietary supplements, 35% to 50% showed high levels of folic acid intake. There was a prevalence of inadequacy for vitamins B2, B6 and B12, ranging from 12.10% to 20.18%, while 13.76% to 22.55% of patients were likely to have adequate choline intake. The considerable percentage of patients with folate intake above the recommended levels deserves attention because of the harmful effects that this nutrient may have in the presence of established neoplastic lesions.

Dietary intakes by different markers of socioeconomic status: results of a New Zealand workforce survey.

PubMed

Metcalf, Patricia; Scragg, Robert; Davis, Peter

2006-08-18

To compare dietary nutrient and food group intakes of men and women in a work force with various measures of socioeconomic status. Daily nutrient intakes were calculated from a self-administered food frequency questionnaire from participants in a cross-sectional health screening survey of a multiracial workforce carried out between May 1988 and April 1990. Participants comprised 5517 Maori, Pacific Island and Other workers (3997 men, 1520 women) aged 40 to 78 years. Socioeconomic measures included the New Zealand Socioeconomic Index (NZSEI), gross household income and level of education. In general, there were trends across socioeconomic status levels with lower NZSEI occupational classes, lower family income, and non-tertiary education groups having lower intakes of dietary fibre, calcium, and alcohol and higher intakes of dietary cholesterol. These were reflected by their lower intakes of fruit, vegetables, milk, cheese and wine, and higher intakes of eggs. However, associations were not consistent across all measures of socioeconomic status. Dietary intakes showed a generally more adverse pattern in the lower socioeconomic strata. NZSEI and education were associated with food group selections, whereas nutrient intakes were associated with income. More money available for food could improve nutrition. Public health programmes to improve nutrition need to be targeted at these groups and be coupled with personal support and structural changes that make "healthy choices the easy choices".

Sewage in ground water in the Florida Keys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinn, E.A.

1995-12-31

More than 24,000 septic tanks, 5,000 cesspools, and greater than 600 shallow disposal wells introduce sewage effluents into porous and permeable limestone underlying the Florida Keys. To porous and permeable limestone underlying the Florida Keys. To assess the fate of sewage nutrients, 21 2- to 20-m-deep wells were core drilled and completed as water-monitoring wells. The wells were sampled quarterly and analyzed for 17 parameters. including nutrients and bacteria. Nutrients (mainly NH4, - which is 30 to 40 times higher than in surface sea water) were detected in ground water beneath the Keys and offshore coral reefs. Highest levels weremore » beneath reefs 5 to 8 km offshore. Ground waters were generally hypersaline and fecal bacteria (fecal coliform and streptococci) were detected in ground water beneath living coral reefs. Higher sea level on the Florida Bay side of the Keys is proposed as the mechanism for forcing ground water toward offshore coral reefs. Tidal pumping, which is more pronounced near the Keys, causes leakage of ground water where the sediment is thin. Areas lacking sediment cover consist of bare limestone bedrock or permeable coral reefs. These are the areas where coral diseases and algal growth have increased in recent years. Pollutants entering the ground water beneath the Florida Keys are likely to be transported seaward beneath impermeable Holocene sediments and may be upwelling through coral reefs and other hardbottom communities.« less

Tidal pumping drives nutrient and dissolved organic matter dynamics in a Gulf of Mexico subterranean estuary

NASA Astrophysics Data System (ADS)

Santos, Isaac R.; Burnett, William C.; Dittmar, Thorsten; Suryaputra, I. G. N. A.; Chanton, Jeffrey

2009-03-01

We hypothesize that nutrient cycling in a Gulf of Mexico subterranean estuary (STE) is fueled by oxygen and labile organic matter supplied by tidal pumping of seawater into the coastal aquifer. We estimate nutrient production rates using the standard estuarine model and a non-steady-state box model, separate nutrient fluxes associated with fresh and saline submarine groundwater discharge (SGD), and estimate offshore fluxes from radium isotope distributions. The results indicate a large variability in nutrient concentrations over tidal and seasonal time scales. At high tide, nutrient concentrations in shallow beach groundwater were low as a result of dilution caused by seawater recirculation. During ebb tide, the concentrations increased until they reached a maximum just before the next high tide. The dominant form of nitrogen was dissolved organic nitrogen (DON) in freshwater, nitrate in brackish waters, and ammonium in saline waters. Dissolved organic carbon (DOC) production was two-fold higher in the summer than in the winter, while nitrate and DON production were one order of magnitude higher. Oxic remineralization and denitrification most likely explain these patterns. Even though fresh SGD accounted for only ˜5% of total volumetric additions, it was an important pathway of nutrients as a result of biogeochemical inputs in the mixing zone. Fresh SGD transported ˜25% of DOC and ˜50% of total dissolved nitrogen inputs into the coastal ocean, with the remainder associated with a one-dimensional vertical seawater exchange process. While SGD volumetric inputs are similar seasonally, changes in the biogeochemical conditions of this coastal plain STE led to higher summertime SGD nutrient fluxes (40% higher for DOC and 60% higher for nitrogen in the summer compared to the winter). We suggest that coastal primary production and nutrient dynamics in the STE are linked.

The effects of human milk fortification on nutrients and milk properties.

PubMed

Donovan, R; Kelly, S G; Prazad, P; Talaty, P N; Lefaiver, C; Hastings, M L; Everly, D N

2017-01-01

To investigate the effects of fortification and storage on nutrients and properties of various human milk (HM) types. Mother's own milk (MOM) and pasteurized donor human milk (DHM; n=118) were analyzed pre- and post fortification with Enfamil and Similac human milk fortifier (EHMF and SHMF) before and after 24 h of refrigerated storage. Milk fortified with SHMF had significantly greater osmolality, pH and lipase activity than EHMF. Changes in protein, pH and osmolality following refrigerated storage differed between fortifiers. When milk type was factored into the analysis, protein and lipase activity changes in fresh MOM differed significantly from DHM and frozen MOM. Analysis of UNF HM found higher protein levels in preterm vs term samples and in MOM vs DHM. Nutrient composition of HM varies significantly by milk type. Although fortifiers enhance select nutrients, each has the potential to affect HM properties in a unique way and these affects may vary by milk type.

Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids

PubMed Central

Janampet, Razia Sultana; Malavath, Kishan Kumar; Neeradi, Rajanna; Chedurupalli, Satyanarayana; Thirunahari, Raghunandan

2016-01-01

Aim: This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. Materials and Methods: A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. Results: There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (p<0.05) in kids fed T2 ration with 50% replacement of groundnut cake with guar meal. Conclusion: It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects. PMID:27847410

Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids.

PubMed

Janampet, Razia Sultana; Malavath, Kishan Kumar; Neeradi, Rajanna; Chedurupalli, Satyanarayana; Thirunahari, Raghunandan

2016-10-01

This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (p<0.05) in kids fed T2 ration with 50% replacement of groundnut cake with guar meal. It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects.

Physiological, biomass elemental composition and proteomic analyses of Escherichia coli ammonium-limited chemostat growth, and comparison with iron- and glucose-limited chemostat growth

PubMed Central

Folsom, James Patrick

2015-01-01

Escherichia coli physiological, biomass elemental composition and proteome acclimations to ammonium-limited chemostat growth were measured at four levels of nutrient scarcity controlled via chemostat dilution rate. These data were compared with published iron- and glucose-limited growth data collected from the same strain and at the same dilution rates to quantify general and nutrient-specific responses. Severe nutrient scarcity resulted in an overflow metabolism with differing organic byproduct profiles based on limiting nutrient and dilution rate. Ammonium-limited cultures secreted up to 35  % of the metabolized glucose carbon as organic byproducts with acetate representing the largest fraction; in comparison, iron-limited cultures secreted up to 70  % of the metabolized glucose carbon as lactate, and glucose-limited cultures secreted up to 4  % of the metabolized glucose carbon as formate. Biomass elemental composition differed with nutrient limitation; biomass from ammonium-limited cultures had a lower nitrogen content than biomass from either iron- or glucose-limited cultures. Proteomic analysis of central metabolism enzymes revealed that ammonium- and iron-limited cultures had a lower abundance of key tricarboxylic acid (TCA) cycle enzymes and higher abundance of key glycolysis enzymes compared with glucose-limited cultures. The overall results are largely consistent with cellular economics concepts, including metabolic tradeoff theory where the limiting nutrient is invested into essential pathways such as glycolysis instead of higher ATP-yielding, but non-essential, pathways such as the TCA cycle. The data provide a detailed insight into ecologically competitive metabolic strategies selected by evolution, templates for controlling metabolism for bioprocesses and a comprehensive dataset for validating in silico representations of metabolism. PMID:26018546

Mycorrhizal fungi enhance plant nutrient acquisition and modulate nitrogen loss with variable water regimes.

PubMed

Bowles, Timothy M; Jackson, Louise E; Cavagnaro, Timothy R

2018-01-01

Climate change will alter both the amount and pattern of precipitation and soil water availability, which will directly affect plant growth and nutrient acquisition, and potentially, ecosystem functions like nutrient cycling and losses as well. Given their role in facilitating plant nutrient acquisition and water stress resistance, arbuscular mycorrhizal (AM) fungi may modulate the effects of changing water availability on plants and ecosystem functions. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant mycorrhiza-defective tomato genotype rmc were grown in microcosms in a glasshouse experiment manipulating both the pattern and amount of water supply in unsterilized field soil. Following 4 weeks of differing water regimes, we tested how AM fungi affected plant productivity and nutrient acquisition, short-term interception of a 15NH4+ pulse, and inorganic nitrogen (N) leaching from microcosms. AM fungi enhanced plant nutrient acquisition with both lower and more variable water availability, for instance increasing plant P uptake more with a pulsed water supply compared to a regular supply and increasing shoot N concentration more when lower water amounts were applied. Although uptake of the short-term 15NH4+ pulse was higher in rmc plants, possibly due to higher N demand, AM fungi subtly modulated NO3- leaching, decreasing losses by 54% at low and high water levels in the regular water regime, with small absolute amounts of NO3- leached (<1 kg N/ha). Since this study shows that AM fungi will likely be an important moderator of plant and ecosystem responses to adverse effects of more variable precipitation, management strategies that bolster AM fungal communities may in turn create systems that are more resilient to these changes. © 2017 John Wiley & Sons Ltd.

Mapping nutrient resorption efficiencies of subarctic cryptogams and seed plants onto the Tree of Life

PubMed Central

Lang, Simone I; Aerts, Rien; van Logtestijn, Richard S P; Schweikert, Wenka; Klahn, Thorsten; Quested, Helen M; van Hal, Jurgen R; Cornelissen, Johannes H C

2014-01-01

Nutrient resorption from senescing photosynthetic organs is a powerful mechanism for conserving nitrogen (N) and phosphorus (P) in infertile environments. Evolution has resulted in enhanced differentiation of conducting tissues to facilitate transport of photosynthate to other plant parts, ultimately leading to phloem. Such tissues may also serve to translocate N and P to other plant parts upon their senescence. Therefore, we hypothesize that nutrient resorption efficiency (RE, % of nutrient pool exported) should correspond with the degree of specialization of these conducting tissues across the autotrophic branches of the Tree of Life. To test this hypothesis, we had to compare members of different plant clades and lichens within a climatic region, to minimize confounding effects of climatic drivers on nutrient resorption. Thus, we compared RE among wide-ranging basal clades from the principally N-limited subarctic region, employing a novel method to correct for mass loss during senescence. Even with the limited numbers of species available for certain clades in this region, we found some consistent patterns. Mosses, lichens, and lycophytes generally showed low REN (<20%), liverworts and conifers intermediate (40%) and monilophytes, eudicots, and monocots high (>70%). REP appeared higher in eudicots and liverworts than in mosses. Within mosses, taxa with more efficient conductance also showed higher REN. The differences in REN among clades broadly matched the degree of specialization of conducting tissues. This novel mapping of a physiological process onto the Tree of Life broadly supports the idea that the evolution of conducting tissues toward specialized phloem has aided land plants to optimize their internal nitrogen recycling. The generality of evolutionary lines in conducting tissues and nutrient resorption efficiency needs to be tested across different floras in different climatic regions with different levels of N versus P availability. PMID:25360262

Diatom Cell Size, Coloniality and Motility: Trade-Offs between Temperature, Salinity and Nutrient Supply with Climate Change

PubMed Central

Svensson, Filip; Norberg, Jon; Snoeijs, Pauline

2014-01-01

Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how “body size” (cells and colonies) and motility change along temperature (2–26°C) and salinity (0.5–7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels. PMID:25279720

Diatom cell size, coloniality and motility: trade-offs between temperature, salinity and nutrient supply with climate change.

PubMed

Svensson, Filip; Norberg, Jon; Snoeijs, Pauline

2014-01-01

Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how "body size" (cells and colonies) and motility change along temperature (2-26°C) and salinity (0.5-7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels.

The Utility of Decomposition and Associated Microbial Parameters to Assess Changes in Stream Ecosystems due to Eutrophication

NASA Astrophysics Data System (ADS)

Gulis, V.; Ferreira, V. J.; Graca, M. A.

2005-05-01

Traditional approaches to assess stream ecosystem health rely on structural parameters, e.g. a variety of biotic indices. The goal of the Europe-wide RivFunction project is to develop methodology that uses functional parameters (e.g. plant litter decomposition) to this end. Here we report on decomposition experiments carried out in Portugal in five pairs of streams that differed in dissolved inorganic nutrients. On average, decomposition rates of alder and oak leaves were 2.8 and 1.4 times higher in high nutrient streams in coarse and fine mesh bags, respectively, than in corresponding reference streams. Breakdown rate correlated better with stream water SRP concentration rather than TIN. Fungal biomass and sporulation rates of aquatic hyphomycetes associated with decomposing leaves were stimulated by higher nutrient levels. Both fungal parameters measured at very early stages of decomposition (e.g. days 7-13) correlated well with overall decomposition rates. Eutrophication had no significant effect on shredder abundances in leaf bags but species richness was higher in disturbed streams. Decomposition is a key functional parameter in streams integrating many other variables and can be useful in assessing stream ecosystem health. We also argue that because decomposition is often controlled by fungal activity, microbial parameters can also be useful in bioassessment.

Groundwater flux and nutrient loading in the northeast section of Bear Lake, Muskegon County, Michigan, 2015

USGS Publications Warehouse

Totten, Alexander R.; Maurer, Jessica A.; Duris, Joseph W.

2017-11-30

Bear Lake in North Muskegon, Michigan, is listed as part of the Muskegon Lake area of concern as designated by the U.S. Environmental Protection Agency. This area of concern was designated as a result of eutrophication and beneficial use impairments. On the northeast end of Bear Lake, two man-made retention ponds (Willbrandt Pond East and Willbrandt Pond West), formerly used for celery farming, may contribute nutrients to Bear Lake. Willbrandt Ponds (East and West) were previously muck fields that were actively used for celery farming from the early 1900s until 2002. The restoration and reconnection of the Willbrandt Ponds into Bear Lake prompted concerns of groundwater nutrient loading into Bear Lake. Studies done by the State of Michigan and Grand Valley State University revised initial internal phosphorus load estimates and indicated an imbalance in the phosphorus budget in Bear Lake. From June through November 2015, the U.S. Geological Survey (USGS) did an investigative study to quantify the load of nutrients from shallow groundwater around the Willbrandt Ponds in an effort to update the phosphorus budget to Bear Lake. Seven sampling locations were established, including five shallow groundwater wells and two surface-water sites, in the Willbrandt pond study area and Bear Lake. A total of 12 nutrient samples and discrete water-level measurements were collected from each site from June through November 2015. Continuous water-level data were recorded for both surface-water monitoring locations for the entire sampling period.Water-level data indicated that Willbrandt Pond West had the highest average water-level elevation of all sites monitored, which indicated the general direction of flux is from Willbrandt Pond West to Bear Lake. Nutrient and chloride loading from Willbrandt Pond West to Bear Lake was calculated using two distinct methods: Dupuit and direct seepage methods. Shallow groundwater loading calculations were determined by using groundwater levels to first determine a flux of shallow groundwater, then nutrient concentrations to determine a load. It was determined that Willbrandt Pond East and Willbrandt Pond West contributed between 2 to 4 percent of the total annual phosphorus load to Bear Lake by way of shallow groundwater flow. Annual loads calculated for other constituents include orthophosphate (40–100 pounds per year [lb P/yr]), total nitrogen (200–830 lb/yr), chloride (12,700–32,100 lb/yr), and ammonia (130–670 lb N/yr). Study results indicated that mean groundwater and surface-water nutrient concentrations calculated in this study were higher than reported Michigan statewide values. The data collected in this study allow understanding of groundwater nutrient loading into Bear Lake in an effort to help inform future restoration and management decisions.

Long-term Nutrient Fertilization Increases CO2 Loss in Arctic Tundra

NASA Astrophysics Data System (ADS)

Graham, L. M.; Natali, S.; Rastetter, E. B.; Shaver, G. R.; Risk, D. A.; Loranty, M. M.; Jastrow, J. D.

2015-12-01

As anthropogenic climate change warms the Arctic, organic carbon (C) trapped in permafrost is at an increased risk of being released to the atmosphere as carbon dioxide (CO2). At the same time, higher rates of decomposition may increase nutrient availability and enhance plant growth, leading to an uptake of C that may offset respiratory losses. Arctic tundra ecosystems are highly nitrogen (N) limited, and the indirect effects of warming on nutrient availability will be the most likely outcome of increased temperature on plant productivity. This study aims to understand the effects of nutrient addition on arctic CO2 and H2O exchange in a tundra ecosystem at Toolik Lake Field Station, Alaska. The nutrient addition experiment, which began in 2006, is comprised of 7 fertilization treatments: 0.5, 1, 2, 5, and 10 g m-2 of N as NO3- and NH4+ (1:1) with 0.25, 0.5, 1, 2.5, and 5 g m-2 of phosphorus as PO43-; 5 g m-2 of N as NO3-; 5 g m-2 of N as NH4+, and one control plot. Plot-level CO2 and H2O exchange was measured at 5 light levels 7 times over a four-week period in June and July 2015. We measured ecosystem CO2 and H2O exchange using a rectangular plexiglass chamber (0.49 m2) that was connected to an infrared gas analyzer (LI-840). Other ecosystem variables measured include thaw depth, soil moisture and temperature, and normalized difference vegetation index. After 10 years of nutrient addition, fertilization significantly altered ecosystem C cycling. Soil respiration was greatest in the highest fertilization treatment (2.97 μmol m-2 s-1), increasing linearly with nutrient level at a rate of 0.133 μmol m-2 s-1 per g m-2 of N added (R2=0.914). Net CO2 uptake was greatest under highest fertilization (-2.06 μmol m-2 s-1), decreasing linearly with nutrient addition at a rate of -0.068 μmol m-2 s-1 per g m-2 of N added (R2=0.687). These results suggest that as nutrients become more available under a warmer climate, plant productivity increases may not offset respiratory losses, leading to a positive feedback to global climate.

Influence of different levels of concentrate and ruminally undegraded protein on digestive variables in beef heifers.

PubMed

Pina, D S; Valadares Filho, S C; Tedeschi, L O; Barbosa, A M; Valadares, R F D

2009-03-01

This experiment evaluated the effect of 2 levels of diet concentrate (20 and 40% of DM) and 2 levels of ruminally undegraded protein (RUP: 25 and 40% of CP) on nutrient intake, total and partial apparent nutrient digestibility, microbial protein synthesis, and ruminal and physiological variables. Eight Nellore heifers (233 +/- 14 kg of BW) fitted with ruminal, abomasal, and ileal cannulas were used. The animals were held in individual sheltered pens of approximately 15 m(2) and fed twice daily at 0800 and 1600 h for ad libitum intake. Heifers were allocated in two 4 x 4 Latin square designs, containing 8 heifers, 4 experimental periods, and 4 treatments in a 2 x 2 factorial arrangement. All statistical analyses were performed using PROC MIXED of SAS. Titanium dioxide (TiO(2)) and chromic oxide (Cr(2)O(3)) were used to estimate digesta fluxes and fecal excretion. Purine derivative (PD) excretion and abomasal purine bases were used to estimate the microbial N (MN) synthesis. No significant interaction (P > 0.10) between dietary levels of RUP and concentrate was observed. There was no effect of treatment (P = 0.24) on DMI. Both markers led to the same estimates of fecal, abomasal, and ileal DM fluxes, and digestibilities of DM and individual nutrients. Ruminal pH was affected by sampling time (P < 0.001), but no interaction between treatment and sampling time was observed (P = 0.71). There was an interaction between treatment and sampling time (P < 0.001) for ruminal NH(3)-N concentration. A linear decrease (P = 0.04) over sampling time was observed for the higher level of RUP, whereas a quadratic effect (P < 0.001) of sampling time was observed for the lower level of RUP. The higher level of dietary concentrate led to greater MN yield regardless of the level of RUP. The MN yield and the efficiency of microbial yield estimated from urinary PD excretion produced greater (P < 0.01) values than those estimated by either TiO(2) or Cr(2)O(3), which did not differ (P = 0.63) from each other. However, all methods yielded values that were within the range reported in the literature. In conclusion, no interactions between dietary levels of RUP and concentrate were observed for ruminal and digestive parameters. Neither RUP nor concentrate level affected DMI. Titanium dioxide showed to be similar to Cr(2)O(3) as an external marker to measure digestibility and nutrient fluxes in cattle.

County-level estimates of nitrogen and phosphorus from commercial fertilizer for the Conterminous United States, 1987–2006

USGS Publications Warehouse

Gronberg, Jo Ann M.; Spahr, Norman E.

2012-01-01

The U.S. Geological Survey’s National Water-Quality Assessment program requires nutrient input for analysis of the national and regional assessment of water quality. Detailed information on nutrient inputs to the environment are needed to understand and address the many serious problems that arise from excess nutrients in the streams and groundwater of the Nation. This report updates estimated county-level farm and nonfarm nitrogen and phosphorus input from commercial fertilizer sales for the conterminous United States for 1987 through 2006. Estimates were calculated from the Association of American Plant Food Control Officials fertilizer sales data, Census of Agriculture fertilizer expenditures, and U.S. Census Bureau county population. A previous national approach for deriving farm and nonfarm fertilizer nutrient estimates was evaluated, and a revised method for selecting representative states to calculate national farm and nonfarm proportions was developed. A national approach was used to estimate farm and nonfarm fertilizer inputs because not all states distinguish between farm and nonfarm use, and the quality of fertilizer reporting varies from year to year. For states that distinguish between farm and nonfarm use, the spatial distribution of the ratios of nonfarm-to-total fertilizer estimates for nitrogen and phosphorus calculated using the national-based farm and nonfarm proportions were similar to the spatial distribution of the ratios generated using state-based farm and nonfarm proportions. In addition, the relative highs and lows in the temporal distribution of farm and nonfarm nitrogen and phosphorus input at the state level were maintained—the periods of high and low usage coincide between national- and state-based values. With a few exceptions, nonfarm nitrogen estimates were found to be reasonable when compared to the amounts that would result if the lawn application rates recommended by state and university agricultural agencies were used. Also, states with higher nonfarm-to-total fertilizer ratios for nitrogen and phosphorus tended to have higher urban land-use percentages.

Cumulative Effects of Nutrient Enrichment and Elevated Temperature Compromise the Early Life History Stages of the Coral Acropora tenuis

PubMed Central

Noonan, Sam H. C.; Willis, Bette L.; Fabricius, Katharina E.; Negri, Andrew P.

2016-01-01

Inshore coral reefs are experiencing the combined pressures of excess nutrient availability associated with coastal activities and warming seawater temperatures. Both pressures are known to have detrimental effects on the early life history stages of hard corals, but studies of their combined effects on early demographic stages are lacking. We conducted a series of experiments to test the combined effects of nutrient enrichment (three levels) and elevated seawater temperature (up to five levels) on early life history stages of the inshore coral Acropora tenuis, a common species in the Indo-Pacific and Red Sea. Gamete fertilization, larval survivorship and larval settlement were all significantly reduced as temperature increased, but only fertilization was further affected by simultaneous nutrient enrichment. Combined high temperatures and nutrient enrichment affected fertilization in an additive manner, whereas embryo abnormalities increased synergistically. Higher than normal temperatures (32°C) increased coral juvenile growth rates 1.6-fold, but mortality also increased by 50%. The co-occurrence of nutrient enrichment with high temperatures reduced juvenile mortality to 36%, ameliorating temperature stress (antagonistic interaction). Overall, the types of effect (additive vs synergistic or antagonistic) and their magnitude varied among life stages. Gamete and embryo stages were more affected by temperature stress and, in some cases, also by nutrient enrichment than juveniles. The data suggest that coastal runoff events might exacerbate the impacts of warming temperatures on fertilization if these events co-occur during corals spawning. The cumulative impacts of simultaneous exposure to nutrient enrichment and elevated temperatures over all early life history stages increases the likelihood for failure of larval supply and recruitment for this coral species. Our results suggest that improving the water quality of river discharges into coastal areas might help to enhance the thermal tolerances of early life history stages in this common coral species. PMID:27575699

Tracking Se Assimilation and Speciation through the Rice Plant – Nutrient Competition, Toxicity and Distribution

PubMed Central

Eiche, Elisabeth; Riemann, Michael; Nick, Peter; Winkel, Lenny H. E.; Göttlicher, Jörg; Steininger, Ralph; Brendel, Rita; von Brasch, Matthias; Konrad, Gabriele; Neumann, Thomas

2016-01-01

Up to 1 billion people are affected by low intakes of the essential nutrient selenium (Se) due to low concentrations in crops. Biofortification of this micronutrient in plants is an attractive way of increasing dietary Se levels. We investigated a promising method of Se biofortification of rice seedlings, as rice is the primary staple for 3 billion people, but naturally contains low Se concentrations. We studied hydroponic Se uptake for 0–2500 ppb Se, potential phyto-toxicological effects of Se and the speciation of Se along the shoots and roots as a function of added Se species, concentrations and other nutrients supplied. We found that rice germinating directly in a Se environment increased plant-Se by factor 2–16, but that nutrient supplementation is required to prevent phyto-toxicity. XANES data showed that selenite uptake mainly resulted in the accumulation of organic Se in roots, but that selenate uptake resulted in accumulation of selenate in the higher part of the shoot, which is an essential requirement for Se to be transported to the grain. The amount of organic Se in the plant was positively correlated with applied Se concentration. Our results indicate that biofortification of seedlings with selenate is a successful method to increase Se levels in rice. PMID:27116220

Nutrient Digestibility and Metabolizable Energy Content of Mucuna pruriens Whole Pods Fed to Growing Pelibuey Lambs

PubMed Central

Loyra-Tzab, Enrique; Sarmiento-Franco, Luis Armando; Sandoval-Castro, Carlos Alfredo; Santos-Ricalde, Ronald Herve

2013-01-01

The nutrient digestibility, nitrogen balance and in vivo metabolizable energy supply of Mucuna pruriens whole pods fed to growing Pelibuey lambs was investigated. Eight Pelibuey sheep housed in metabolic crates were fed increasing levels of Mucuna pruriens pods: 0 (control), 100 (Mucuna100), 200 (Mucuna200) and 300 (Mucuna300) g/kg dry matter. A quadratic (p<0.002) effect was observed for dry matter (DM), neutral detergent fibre (aNDF), nitrogen (N) and gross energy (GE) intakes with higher intakes in the Mucuna100 and Mucuna200 treatments. Increasing M. pruriens in the diets had no effect (p>0.05) on DM and GE apparent digestibility (p<0.05). A linear reduction in N digestibility and N retention was observed with increasing mucuna pod level. This effect was accompanied by a quadratic effect (p<0.05) on fecal-N and N-balance which were higher in the Mucuna100 and Mucuna200 treatments. Urine-N excretion, GE retention and dietary estimated nutrient supply (metabolizable protein and metabolizable energy) were not affected (p>0.05). DM, N and GE apparent digestibility coefficient of M. pruriens whole pods obtained through multiple regression equations were 0.692, 0.457, 0.654 respectively. In vivo DE and ME content of mucuna whole pod were estimated in 11.0 and 9.7 MJ/kg DM. It was concluded that whole pods from M. pruriens did not affect nutrient utilization when included in an mixed diet up to 200 g/kg DM. This is the first in vivo estimation of mucuna whole pod ME value for ruminants. PMID:25049876

Predation and nutrients drive population declines in breeding waders.

PubMed

Møller, Anders Pape; Thorup, Ole; Laursen, Karsten

2018-04-20

Allee effects are defined as a decline in per capita fitness at low population density. We hypothesized that predation reduces population size of breeding waders and thereby the efficiency of predator deterrence, while total nitrogen through its effects on primary and secondary productivity increases population size. Therefore, nest predation could have negative consequences for population size because nest failure generally results in breeding dispersal and hence reduced local population density. To test these predictions, we recorded nest predation in five species of waders for 4,745 nests during 1987-2015 at the nature reserve Tipperne, Denmark. Predation rates were generally negatively related to conspecific and heterospecific population density, but positively related to overall population density of the entire wader community. Nest predation and population density were related to ground water level, management (grazing and mowing), and nutrients. High nest predation with a time lag of one year resulted in low overall breeding population density, while high nutrient levels resulted in higher population density. These two factors accounted for 86% of the variance in population size, presumably due to effects of nest predation on emigration, while nutrient levels increased the level of vegetation cover and the abundance of food in the surrounding brackish water. These findings are consistent with the hypothesis that predation may reduce population density through negative density dependence, while total nitrogen at adjacent shallow water may increase population size. Nest predation rates were reduced by high ground water level in March, grazing by cattle and mowing that affected access to and susceptibility of nests to predators. These effects can be managed to benefit breeding waders. © 2018 by the Ecological Society of America.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

NASA Astrophysics Data System (ADS)

Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

2018-05-01

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River

USGS Publications Warehouse

Houser, Jeff N.; Giblin, Shawn M.; James, William F.; Langrehr, H.A.; Rogala, James T.; Sullivan, John F.; Gray, Brian R.

2013-01-01

River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper Mississippi River (UMR) that varied in connectivity to the channel. Greater connectivity was associated with higher water column nitrate (NO3-N) concentration, higher rates of sediment phosphorus (P) release, and higher rates of NO3-N flux to the sediments. Rates of sediment P and N (as NH4-N) release were similar to those of eutrophic lakes. Water column nutrient concentrations were high, and FFP tissue was nutrient rich suggesting that the eutrophic condition of the UMR often facilitated abundant FFP. However, tissue nutrient concentrations, and the associations between FFP biomass and water column nutrient concentrations, suggested that nutrients constrained FFP abundance at some sites. FFP abundance was positively associated with SAV abundance and negatively associated with dissolved oxygen concentration. These results illustrate important connections among hydraulic connectivity, nutrient cycling, FFP, SAV, and DO in the backwaters of a large, floodplain river.

Marine Biogeochemistry Under The Influence of Fish And Fisheries: An Ecosystem Modeling Study

NASA Astrophysics Data System (ADS)

Disa, Deniz; Akoglu, Ekin; Salihoglu, Baris

2017-04-01

The ocean and the marine ecosystems are important controllers of the global carbon cycle. They play a pivotal role in capturing atmospheric carbon into the ocean body, transforming it into organic carbon through photosynthesis and transporting it to the depths of the ocean. Fish, which has a significant role in the marine food webs, is thought to have a considerable impact on carbon export. More specifically, fish has a control on plankton dynamics as a predator, it provides nutrient to the ecosystem by its metabolic activities and it has the ability of moving actively and transporting materials. Fishing is also expected to impact carbon cycle because it directly changes the fish biomasses. However, how fish impacts the biogeochemistry of marine ecosystems is not studied extensively. The aim of this study is to analyze the impact of fish and fisheries on marine biogeochemical processes by setting up an end-to-end model, which simulates lower and higher tropic levels of marine ecosystems simultaneously. For this purpose, a one dimensional biogeochemical model simulating lower tropic level dynamics (e.g. carbon export, nutrient cycles) and an food web model simulating fisheries exploitation and higher tropic level dynamics were online and two-way coupled. Representing the marine ecosystem from one end to the other, the coupled model served as a tool for the analysis of fishing impacts on marine biogeochemical dynamics. Results obtained after incorporation of higher trophic level model changed the plankton compositions and enhanced detritus pools and increased carbon export. Additionally, our model showed that active movement of fish contributed to transport of carbon from surface to the deeper parts of the ocean. Moreover, results after applying different fishing intensities indicated that changes in fisheries exploitation levels directly influence the marine nutrient cycles and hence, the carbon export. Depending on the target and the intensity of fisheries, considerable changes in the biogeochemical responses observed. In conclusion, unlike the models that do not represent the fish explicitly, we demonstrate how marine biogeochemical processes are impacted by the activity of fish assemblages and fisheries exploitation.

Research to Inform Nutrient Thresholds and Prioritization of ...

EPA Pesticide Factsheets

The information in this presentation focuses on SSWR's 4.02 project, which will advance the science needed to inform decisions to prioritize watersheds and nutrient sources for nutrient management and define appropriate nutrient levels for the nation’s waters, two important elements of EPA’s framework for managing nutrient pollution. The information in this presentation focuses on SSWR's 4.02 project, which will advance the science needed to inform decisions to prioritize watersheds and nutrient sources for nutrient management and define appropriate nutrient levels for the nation’s waters, two important elements of EPA’s framework for managing nutrient pollution.

Soil nutrient bioavailability and nutrient content of pine trees (Pinus thunbergii) in areas impacted by acid deposition in Korea.

PubMed

Yang, Jae E; Lee, Wi-Young; Ok, Yong Sik; Skousen, Jeffrey

2009-10-01

Acid deposition has caused detrimental effects on tree growth near industrial areas of the world. Preliminary work has indicated that concentrations of NO(3-), SO(4)(2-), F( - ) and Al in soil solutions were 2 to 33 times higher in industrial areas compared to non-industrial areas in Korea. This study evaluated soil nutrient bioavailability and nutrient contents of red pine (Pinus thunbergii) needles in forest soils of industrial and non-industrial areas of Korea. Results confirm that forest soils of industrial areas have been acidified mainly by deposition of sulfate, resulting in increases of Al, Fe and Mn and decreases of Ca, Mg and K concentrations in soils and soil solutions. In soils of industrial areas, the molar ratios of Ca/Al and Mg/Al in forest soils were <2, which can lead to lower levels and availability of nutrients for tree growth. The Ca/Al molar ratio of Pinus thunbergii needles on non-industrial sites was 15, while that of industrial areas was 10. Magnesium concentrations in needles of Pinus thunbergii were lower in soils of industrial areas and the high levels of acid cations such as Al and Mn in these soils may have antagonized the uptake of base cations like Mg. Continued acidification can further reduce uptake of base cations by trees. Results show that Mg deficiency and high concentrations of Al and Mn in soil solution can be limiting factors for Pinus thunbergii growth in industrial areas of Korea.

An assessment of seabird influence on Arctic coastal benthic communities

NASA Astrophysics Data System (ADS)

Zmudczyńska-Skarbek, Katarzyna; Balazy, Piotr; Kuklinski, Piotr

2015-04-01

It is well recognized that seabirds, particularly those nesting in coastal colonies, can provide significant nutrient enrichment to Arctic terrestrial ecosystems. However, little is known about the fate of bird-derived nutrients that return to the marine environment and potentially concentrate below the colonies. To attempt to assess the influence of this potential nutrient enrichment of the coastal benthic community, samples of macroalgae, sea urchins (mainly algivores), and hermit crabs (scavengers) were collected at two Arctic localities (Spitsbergen), (1) below a mixed colony of guillemots and kittiwakes, and (2) in an adjacent geomorphologically similar location not influenced by the seabird colony. A much higher nitrogen stable isotope ratio (δ15N) and total nitrogen content were found in terrestrial plants sampled below the colony than away from it. In benthic macroalgae, however, there were no δ15N differences. This might result from the timing of an intensive growth period in macroalgae in late winter/early spring, when there is little or no runoff from the land, and/or ornithogenic nutrients being directly incorporated by phytoplankton. Sea urchins showed higher δ15N and total N in the control site comparing to the colony-influenced area, suggesting differential food sources in their diet and a role of scavenging/carnivory on higher trophic levels there. Opportunistically feeding hermit crabs showed δ15N and total N enrichment below the seabird colony, suggesting dependence on detritus derived from food chains originating from pelagic producers. Our results indicate that seabirds in the Arctic may fertilize coastal benthic communities through pelagic-benthic coupling, while having no direct impact on bottom primary production.

National Aquatic Resource Surveys (NARS) N/P Values for Streams - Wadeable Streams Assessment

EPA Pesticide Factsheets

The National Aquatic Resource Survey (NARS) findings for nutrients in streams and lakes highlight that nutrient pollution is widespread across the United States and impacts biological communities. The NARS analysis examined the range of values for nutrients in least-disturbed sites in a WSA region [WSA regions are modified Level III ecoregions from Omernik (1987)] and used this distribution for nitrogen (N) and phosphorus (P) to separate sites into those having high, medium, or low concentrations of nutrients. Sites identified as high were worse (i.e., had higher nutrient concentrations) than 95% of the sites used to define least-disturbed condition. Similarly, the 75th percentile of the least-disturbed distribution was used to distinguish between sites in medium and low condition. This means that sites reported as being as low were as good as or better than 75% of the sites used to define least-disturbed condition. A relative risk analysis of the data from this survey found that nationally streams and lakes have more than two times greater risk of having degraded biological communities when nutrient concentrations are high than when they are low. For more information, please consult the National Wadeable Streams Assessment (WSA) Report available online at: https://www.epa.gov/national-aquatic-resource-surveys/nrsa:

Effects of irradiation intensity and pH on nutrients release and solids destruction of waste activated sludge using the microwave-enhanced advanced oxidation process.

PubMed

Chan, W I; Liao, P H; Lo, K V

2010-11-01

Using the microwave-enhanced advanced oxidation process (MW/H2O2-AOP), the pH and irradiation intensity on waste activated sludge samples were investigated to provide insight to the athermal effects on nutrients release, solids destruction, particle size distribution and dewaterability, and to demonstrate their interrelationships. Carbonaceous matters and nutrients released into solution depended on the irradiation intensity and time. Higher irradiation levels tended to be more effective in the solubilization of nutrients and had more pronounced effects in the dewaterability of sludge. In terms of particle size distribution, detectable particles increased in size for treatments in acidic conditions, while the dewaterability of treated sludge was improved. In treatments under neutral and alkaline conditions, the particle size range increased, with more small particles formed, thereby significantly deteriorating the dewaterability of sludge treated in alkaline conditions. The best results for the solubilization of nutrients were in alkaline conditions with high irradiation power, but dewaterability of the sludge was compromised. Sludge treatment with the MW/H2O2-AOP in acidic conditions with high irradiation power yielded the best dewaterable sludge and significant nutrient solubilization; therefore, it is the recommended treatment condition for activated sludge.

Contribution of Dietary Supplements to Nutritional Adequacy in Race/Ethnic Population Subgroups in the United States.

PubMed

Blumberg, Jeffrey B; Frei, Balz; Fulgoni, Victor L; Weaver, Connie M; Zeisel, Steven H

2017-11-28

The U.S. Centers for Disease Control and Prevention has reported that nutritional deficiencies in the U.S. population vary by age, gender, and race/ethnicity, and could be as high as nearly one third of certain population groups. Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES) primarily from 2009-2012, assessments were made of race/ethnic differences in the impact of dietary supplements on nutrient intake and prevalence of inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly higher intakes of 14 to 16 of 19 nutrients examined in all race/ethnic groups; and significantly ( p < 0.01) reduced rates of inadequacy for 8/17 nutrients examined in non-Hispanic whites, but only 3-4/17 nutrients (calcium, and vitamins A, D, and E) for other race/ethnic groups. Across race/ethnic groups an increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 1-9/13 nutrients, but all were less than 5% of the population. In conclusion, use of dietary supplements is associated with increased micronutrient intake, decreased nutrient inadequacies, and slight increases in prevalence above the UL in all race/ethnicities examined, with greater benefits among non-Hispanic whites.

Nutrient digestibility of broiler feeds containing different levels of variously processed rice bran stored for different periods.

PubMed

Mujahid, A; Asif, M; ul Haq, I; Abdullah, M; Gilani, A H

2003-09-01

Nutrient digestibility of broiler feeds containing different levels of variously processed rice bran stored for varying periods was determined. A total of 444 Hubbard male chicks were used to conduct four trials. Each trial was carried out on 111 chicks to determine digestibility of 36 different feeds. Chicks of 5 wk age were fed feeds containing raw, roasted, and extruded rice bran treated with antioxidant, Bianox Dry (0, 125, 250 g/ton), stored for a periods of 0, 4, 8, and 12 mo and used at levels of 0, 10, 20, and 30% in feeds. Digestibility coefficients for fat and fiber of feeds were determined. Increasing storage periods of rice bran significantly reduced the fat digestibility of feed, whereas no difference in fiber digestibility was observed. Processing of rice bran by extrusion cooking significantly increased digestibility of fat even used at higher levels in broiler feeds. Interaction of storage, processing, and levels was significant for fat digestibility. Treatments of rice bran by different levels of antioxidant had no effect on digestibility of fat and fiber when incorporated in broiler feed.

Filling Gaps in Biogeochemical Understanding of Wildfire Effects on Watersheds and Water Quality

NASA Astrophysics Data System (ADS)

Rhoades, Charles; Covino, Timothy; Chow, Alex

2017-04-01

Large, high-severity wildfires alter the biogeochemical conditions that determine how watersheds retain and release nutrients and influence stream water quality. These effects are commonly expected to abate within a few years, but recent studies show that post-fire watershed changes can have persistent, but poorly-understood biogeochemical consequences. Owing to the increased frequency and extent of high-severity wildfires predicted for western North America, and the growing awareness of the links between wildfire and clean water supply, there is a need to address these knowledge gaps. For the past 15 years we have tracked stream nutrients, chemistry, temperature, and sediment after the 2002 Hayman Fire, the largest wildfire in Colorado history. Our earlier work showed that headwater catchments that experienced extensive, high-severity forest fires had elevated stream nitrate, temperature, and turbidity for five post-fire years. Recent sampling, conducted 13 and 14 years after the fire, found that turbidity had largely returned to pretreatment levels, but that stream nitrate remained an order of magnitude above pre-fire levels in catchments with extensive high-severity wildfire. Stream temperature and total dissolved nitrogen concentration also remained higher in those catchments compared to unburned streams. Decreased plant demand is the mechanism commonly credited for post-fire nutrient losses, though our current work is evaluating the implications of soil and stream nutrient uptake and supply on persistent nitrogen (N) export from severely-burned catchments. For example, we have measured higher total soil N and higher net N mineralization in severely-burned portions of the Hayman Fire compared to moderately or unburned areas, indicating that higher soil N supply may contribute to N losses from upland soils. Conversely, using a nutrient tracer approach we found reduced N uptake in burned streams, which suggests a switch from the N-limited conditions typical of pristine catchments. Low stream dissolved organic carbon (DOC) in severely-burned catchments suggests greater carbon limitation on in-stream biological activity. This is the likely result of organic matter losses during the wildfire compounded by low allochthonous inputs from uplands or riparian zones. We also find that catchments with severely-burned headwater reaches and sparse riparian vegetation have high stream nitrate. Our findings regarding soil N supply and in-stream N retention coupled with the persistent N losses from burned headwaters and exposed riparian zones help prioritize restoration efforts aimed at mitigating long-term water quality effects of severe wildfires.

Effect of protein level and urea in concentrate mixture on feed intake and rumen fermentation in swamp buffaloes fed rice straw-based diet.

PubMed

Kang, Sungchhang; Wanapat, Metha; Phesatcha, Kampanat; Norrapoke, Thitima

2015-04-01

Four rumen-fistulated Thai native swamp buffaloes were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design to assess the effect of protein (CP) level and urea (U) source in concentrate diet on feed utilization and rumen ecology. The treatments were as follows: concentrate containing CP at 120 g/kg (soybean meal, SBM) (T1), 160 g/kg (SBM) (T2), 120 g/kg (U) (T3), and 160 g/kg (U) (T4), respectively. All buffaloes were fed concentrate at 10 g/kg of body weight, and rice straw was offered ad libitum. Feed intake and digestibilities of CP, neutral detergent fiber, and acid detergent fiber increased (P < 0.05) in treatments with higher level of CP especially with U source (P < 0.05). In contrast, CP level and source in concentrate did not affect on ruminal pH and temperature (P > 0.05), while concentration of ruminal ammonia (N), blood urea (U), volatile fatty acids profile, microorganism populations, and variable bacterial growth increased in buffaloes consumed concentrate containing CP at 160 g/kg (T2 and T4; P < 0.05). Fecal and urinary N excretions decreased in buffaloes consumed concentrate containing higher CP level especially with U source while purine derivatives increased which resulted in a higher N balance as compared to lower CP level and SBM source treatments (P < 0.05). In summary, higher CP level in concentrate improved feed intake, nutrient digestibility, purine derivatives, and rumen ecology, and U had shown better result than SBM. Concentrate mixtures containing 16 g/kg CP with U 40 g/kg could improved nutrients utilization with no adverse effects for swamp buffaloes fed on rice straw.

Inclusion of human mineralized exometabolites and fish wastes as a source of higher plant mineral nutrition in BTLSS mass exchange

NASA Astrophysics Data System (ADS)

Tikhomirova, Natalia; Tikhomirov, Alexander A.; Ushakova, Sofya; Anischenko, Olesya; Trifonov, Sergey V.

Human exometabolites inclusion into an intrasystem mass exchange will allow increasing of a closure level of a biological-technical life support system (BTLSS). Previously at the IBP SB RAS it was shown that human mineralized exometabolites could be incorporated in the BTLSS mass exchange as a mineral nutrition source for higher plants. However, it is not known how that combined use of human mineralized exometabolites and fish wastes in the capacity of nutrient medium, being a part of the BTLSS consumer wastes, will affect the plant productivity. Several wheat vegetations were grown in an uneven-aged conveyor on a neutral substrate. A mixture of human mineralized exometabolites and fish wastes was used as a nutrient solution in the experiment treatment and human mineralized exometabolites were used in the control. Consequently, a high wheat yield in the experiment treatment practically equal to the control yield was obtained. Thus, mineralized fish wastes can be an additional source of macro-and micronutrients for plants, and use of such wastes for the plant mineral nutrition allows increasing of BTLSS closure level.

Competition for nutrients and light: testing advances in resource competition with a natural phytoplankton community.

PubMed

Burson, Amanda; Stomp, Maayke; Greenwell, Emma; Grosse, Julia; Huisman, Jef

2018-05-01

A key challenge in ecology is to understand how nutrients and light affect the biodiversity and community structure of phytoplankton and plant communities. According to resource competition models, ratios of limiting nutrients are major determinants of species composition. At high nutrient levels, however, species interactions may shift to competition for light, which might make nutrient ratios less relevant. The "nutrient-load hypothesis" merges these two perspectives, by extending the classic model of competition for two nutrients to include competition for light. Here, we test five key predictions of the nutrient-load hypothesis using multispecies competition experiments. A marine phytoplankton community sampled from the North Sea was inoculated in laboratory chemostats provided with different nitrogen (N) and phosphorus (P) loads to induce either single resource limitation or co-limitation of N, P, and light. Four of the five predictions were validated by the experiments. In particular, different resource limitations favored the dominance of different species. Increasing nutrient loads caused changes in phytoplankton species composition, even if the N:P ratio of the nutrient loads remained constant, by shifting the species interactions from competition for nutrients to competition for light. In all treatments, small species became dominant whereas larger species were competitively excluded, supporting the common view that small cell size provides a competitive advantage under resource-limited conditions. Contrary to expectation, all treatments led to coexistence of diatoms, cyanobacteria and green algae, resulting in a higher diversity of species than predicted by theory. Because the coexisting species comprised three phyla with different photosynthetic pigments, we speculate that niche differentiation in the light spectrum might play a role. Our results show that mechanistic resource competition models that integrate nutrient-based and light-based approaches provide an important step forward to understand and predict how changing nutrient loads affect community composition. © 2018 The Authors Ecology published by Wiley Periodicals, Inc. on behalf of Ecological Society of America.

Dietary patterns in UK adolescents obtained from a dual-source FFQ and their associations with socio-economic position, nutrient intake and modes of eating.

PubMed

Northstone, Kate; Smith, Andrew D A C; Cribb, Victoria L; Emmett, Pauline M

2014-07-01

To derive dietary patterns using principal components analysis from separate FFQ completed by mothers and their teenagers and to assess associations with nutrient intakes and sociodemographic variables. Two distinct FFQ were completed by 13-year-olds and their mothers, with some overlap in the foods covered. A combined data set was obtained. Avon Longitudinal Study of Parents and Children (ALSPAC), Bristol, UK. Teenagers (n 5334) with adequate dietary data. Four patterns were obtained using principal components analysis: a 'Traditional/health-conscious' pattern, a 'Processed' pattern, a 'Snacks/sugared drinks' pattern and a 'Vegetarian' pattern. The 'Traditional/health-conscious' pattern was the most nutrient-rich, having high positive correlations with many nutrients. The 'Processed' and 'Snacks/sugared drinks' patterns showed little association with important nutrients but were positively associated with energy, fats and sugars. There were clear gender and sociodemographic differences across the patterns. Lower scores were seen on the 'Traditional/health conscious' and 'Vegetarian' patterns in males and in those with younger and less educated mothers. Higher scores were seen on the 'Traditional/health-conscious' and 'Vegetarian' patterns in girls and in those whose mothers had higher levels of education. It is important to establish healthy eating patterns by the teenage years. However, this is a time when it is difficult to accurately establish dietary intake from a single source, since teenagers consume increasing amounts of foods outside the home. Further dietary pattern studies should focus on teenagers and the source of dietary data collection merits consideration.

Nutrient contributions to the Santa Barbara Channel, California, from the ephemeral Santa Clara River

USGS Publications Warehouse

Warrick, J.A.; Washburn, L.; Brzezinski, Mark A.; Siegel, D.A.

2005-01-01

The Santa Clara River delivers nutrient rich runoff to the eastern Santa Barbara Channel during brief (???1-3 day) episodic events. Using both river and oceanographic measurements, we evaluate river loading and dispersal of dissolved macronutrients (silicate, inorganic N and P) and comment on the biological implications of these nutrient contributions. Both river and ocean observations suggest that river nutrient concentrations are inversely related to river flow rates. Land use is suggested to influence these concentrations, since runoff from a subwatershed with substantial agriculture and urban areas had much higher nitrate than runoff from a wooded subwatershed. During runoff events, river nutrients were observed to conservatively mix into the buoyant, surface plume immediately seaward of the Santa Clara River mouth. Dispersal of these river nutrients extended 10s of km into the channel. Growth of phytoplankton and nutrient uptake was low during our observations (1-3 days following runoff), presumably due to the very low light levels resulting from high turbidity. However, nutrient quality of runoff (Si:N:P = 16:5:1) was found to be significantly different than upwelling inputs (13:10:1), which may influence different algal responses once sediments settle. Evaluation of total river nitrate loads suggests that most of the annual river nutrient fluxes to the ocean occur during the brief winter flooding events. Wet winters (such as El Nin??o) contribute nutrients at rates approximately an order-of-magnitude greater than "average" winters. Although total river nitrate delivery is considerably less than that supplied by upwelling, the timing and location of these types of events are very different, with river discharge (upwelling) occurring predominantly in the winter (summer) and in the eastern (western) channel. ?? 2004 Elsevier Ltd. All rights reserved.

Effect of Canning and Freezing on the Nutritional Content of Apricots.

PubMed

Adkison, Erin Claire; Biasi, William B; Bikoba, Veronique; Holstege, Dirk M; Mitcham, Elizabeth J

2018-05-22

The effect of commercial canning and freezing on the nutritional content of fresh apricots was investigated. Processed samples were analyzed post-processing and after 3 months of storage and compared directly to fresh apricots from the same source. Vitamin C, beta-carotene, total phenols, and antioxidants were quantified. Compared to fresh, canned apricots initially exhibited similar levels of antioxidants, a 17% increase in beta-carotene, and a 48% increase in phenols, while vitamin C was reduced by 37%. After 3 months of storage, antioxidant levels were 47% higher than fresh. Vitamin C did not change significantly following storage and beta-carotene decreased by 15%. The canned apricot fruit packed in light syrup did not have higher total soluble solids (TSS) levels indicating no increase in fruit sugar content. Frozen apricots exhibited large increases in antioxidants (529%), beta-carotene (35%), vitamin C (3,370%), and phenols (406%) compared to fresh. After 3 months of storage, frozen apricots decreased in vitamin C (29%) and phenols (17%), but remained 2,375% and 318% higher than fresh, respectively. Beta-carotene increased during storage, reaching levels 56% higher than fresh while antioxidant activity was unchanged. This study demonstrates that key nutrients in canned and frozen apricots are retained or amplified upon processing, with the exception of vitamin C in canned apricots. The routine addition of citric and ascorbic acid to fruit prior to freezing resulted in significantly higher antioxidants, vitamin C, and phenols. Consumers eating canned or frozen apricots can feel confident of similar or superior nutritional content as compared to fresh apricots. The apricot industry is limited by the short shelf life of the fruit and consumer belief that processed produce is not as nutritious as fresh. Assessing the nutritional content of canned and frozen apricots and determining that processed apricots can deliver nearly comparable nutrient levels to fresh apricots provides the evidence needed to dispel these misconceptions and potentially increase demand for processed apricots among consumers. © 2018 Institute of Food Technologists®.

Mechanisms for Success after Long-term Nutrient Enrichment in a Boreal Forest Understory

PubMed Central

Grainger, Tess Nahanni; Turkington, Roy

2013-01-01

Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually) on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest understory. PMID:23573298

Productivity and river flux variability in response to the PETM on Atlantic margin at Bass River, NJ.

NASA Astrophysics Data System (ADS)

Stoll, H.; Shimizu, N.; Savain, R.; Zachos, J.; Ziveri, P.

2009-04-01

While the dramatic climate warming of the Paleocene-Eocene Thermal Maximum has been well characterized, changes in the hydrological cycle and the broader biogeochemical feedbacks (weathering, nutrients, productivity) are less well constrained. Here we describe new geochemical results from a coastal section on the midlatitude Atlantic margin of the U.S. at Bass River, NJ. We measured the elemental geochemistry of coccoliths to probe the productivity of these algae in response to the changing nutrient dynamics on the shelf in the time interval preceding and during the PETM. Coccoliths extracted from the siliclastic coastal section at Bass River NJ exhibit exceptionally good preservation and negligible overgrowth compared to typical ocean carbonate-rich sediments. Analysis of individual coccoliths using secondary ion mass spectrometry (SIMS) facilitates reliable trace element measurements in this low-carbonate section. Published sequence stratigraphy and microfossil analysis have revealed several third order sea level cycles in the late Paleocene including a highstand during the PETM. Consequently we extend our paleoproductivity records far below the PETM to characterize this background variability. We recognize a pattern of generally maximum productivity during lowstands and minimal productivity during highstands. Because nutrient concentrations decrease significantly with distance from the coast, highstands reduce productivity by shifting the highest nutrient levels landward, away from the site. This is likely due to greater distance from river sources as well as reduced wave turbulence which mixes nutrients into the photic zone. This general pattern is broken during the PETM, which features high productivity despite a sea level highstand. This anomalous high productivity may reflect enhanced riverine nutrient delivery, and potentially changes in wind strength and mixing intensity. Riverine nutrient delivery could increase with higher precipitation or precipitation seasonality, and/or higher weathering intensity. In support of enhanced riverine flow, seawater d18O ratios, calculated from coccolith d18O and TEX86 temperatures, indicate a strong decrease characteristic of freshening during the PETM. The excellent preservation of coccoliths also enables us to examine interspecific vital effects on coccolith stable isotopes, with minimal diagenetic homogenization. In Bass River coccolith size fractions separated and measured from the same sediments, the vital effects among different size fractions are <0.5 permil in carbon and oxygen isotope ratios, with little change over the PETM, consistent with our earlier results from ODP 690. This contrasts with the large range of stable isotope vital effects in modern cultures and sediment traps, which correlate with cell size and carbonate ion. These results support our hypothesis that the range of interspecific vital effects may have been reduced in the high-CO2 Paleocene ocean when the modern diversity of carbon concentrating mechanisms was not required.

De Novo Assembly of the Whole Transcriptome of the Wild Embryo, Preleptocephalus, Leptocephalus, and Glass Eel of Anguilla japonica and Deciphering the Digestive and Absorptive Capacities during Early Development.

PubMed

Hsu, Hsiang-Yi; Chen, Shu-Hwa; Cha, Yuh-Ru; Tsukamoto, Katsumi; Lin, Chung-Yen; Han, Yu-San

2015-01-01

Natural stocks of Japanese eel (Anguilla japonica) have decreased drastically because of overfishing, habitat destruction, and changes in the ocean environment over the past few decades. However, to date, artificial mass production of glass eels is far from reality because of the lack of appropriate feed for the eel larvae. In this study, wild glass eel, leptocephali, preleptocephali, and embryos were collected to conduct RNA-seq. Approximately 279 million reads were generated and assembled into 224,043 transcripts. The transcript levels of genes coding for digestive enzymes and nutrient transporters were investigated to estimate the capacities for nutrient digestion and absorption during early development. The results showed that the transcript levels of protein digestion enzymes were higher than those of carbohydrate and lipid digestion enzymes in the preleptocephali and leptocephali, and the transcript levels of amino acid transporters were also higher than those of glucose and fructose transporters and the cholesterol transporter. In addition, the transcript levels of glucose and fructose transporters were significantly raising in the leptocephali. Moreover, the transcript levels of protein, carbohydrate, and lipid digestion enzymes were balanced in the glass eel, but the transcript levels of amino acid transporters were higher than those of glucose and cholesterol transporters. These findings implied that preleptocephali and leptocephali prefer high-protein food, and the nutritional requirements of monosaccharides and lipids for the eel larvae vary with growth. An online database (http://molas.iis.sinica.edu.tw/jpeel/) that will provide the sequences and the annotated results of assembled transcripts was established for the eel research community.

De Novo Assembly of the Whole Transcriptome of the Wild Embryo, Preleptocephalus, Leptocephalus, and Glass Eel of Anguilla japonica and Deciphering the Digestive and Absorptive Capacities during Early Development

PubMed Central

Cha, Yuh-Ru; Tsukamoto, Katsumi; Lin, Chung-Yen; Han, Yu-San

2015-01-01

Natural stocks of Japanese eel (Anguilla japonica) have decreased drastically because of overfishing, habitat destruction, and changes in the ocean environment over the past few decades. However, to date, artificial mass production of glass eels is far from reality because of the lack of appropriate feed for the eel larvae. In this study, wild glass eel, leptocephali, preleptocephali, and embryos were collected to conduct RNA-seq. Approximately 279 million reads were generated and assembled into 224,043 transcripts. The transcript levels of genes coding for digestive enzymes and nutrient transporters were investigated to estimate the capacities for nutrient digestion and absorption during early development. The results showed that the transcript levels of protein digestion enzymes were higher than those of carbohydrate and lipid digestion enzymes in the preleptocephali and leptocephali, and the transcript levels of amino acid transporters were also higher than those of glucose and fructose transporters and the cholesterol transporter. In addition, the transcript levels of glucose and fructose transporters were significantly raising in the leptocephali. Moreover, the transcript levels of protein, carbohydrate, and lipid digestion enzymes were balanced in the glass eel, but the transcript levels of amino acid transporters were higher than those of glucose and cholesterol transporters. These findings implied that preleptocephali and leptocephali prefer high-protein food, and the nutritional requirements of monosaccharides and lipids for the eel larvae vary with growth. An online database (http://molas.iis.sinica.edu.tw/jpeel/) that will provide the sequences and the annotated results of assembled transcripts was established for the eel research community. PMID:26406914

Dietary glutamine supplementation effects on amino acid metabolism, intestinal nutrient absorption capacity and antioxidant response of gilthead sea bream (Sparus aurata) juveniles.

PubMed

Coutinho, F; Castro, C; Rufino-Palomares, E; Ordóñez-Grande, B; Gallardo, M A; Oliva-Teles, A; Peres, H

2016-01-01

A study was undertaken to evaluate dietary glutamine supplementation effects on gilthead sea bream performance, intestinal nutrient absorption capacity, hepatic and intestinal glutamine metabolism and oxidative status. For that purpose gilthead sea bream juveniles (mean weight 13.0g) were fed four isolipidic (18% lipid) and isonitrogenous (43% protein) diets supplemented with 0, 0.5, 1 and 2% glutamine for 6weeks. Fish performance, body composition and intestinal nutrient absorption capacity were not affected by dietary glutamine levels. Hepatic and intestinal glutaminase (GlNase), glutamine synthetase (GSase), alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase activities were also unaffected by dietary glutamine supplementation. In the intestine GlNase activity was higher and GSase/GlNase ratio was two-fold lower than in the liver, suggesting a higher use of glutamine for energy production by the intestine than by the liver. The liver showed higher catalase and glucose-6-phosphate dehydrogenase activities, while the intestine presented higher glutathione peroxidase and glutathione reductase activities and oxidised glutathione content, which seems to reveal a higher glutathione dependency of the intestinal antioxidant response. Total and reduced glutathione contents in liver and intestine and superoxide dismutase activity in the intestine were enhanced by dietary glutamine, though lipid peroxidation values were not affected. Overall, differences between liver and intestine glutamine metabolism and antioxidant response were identified and the potential of dietary glutamine supplementation to gilthead sea bream's antioxidant response was elucidated. Copyright © 2015 Elsevier Inc. All rights reserved.

A cost analysis of microalgal biomass and biodiesel production in open raceways treating municipal wastewater and under optimum light wavelength.

PubMed

Kang, Zion; Kim, Byung-Hyuk; Ramanan, Rishiram; Choi, Jong-Eun; Yang, Ji-Won; Oh, Hee-Mock; Kim, Hee-Sik

2015-01-01

Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

Nutrient fluctuations in the Quatipuru river: A macrotidal estuarine mangrove system in the Brazilian Amazonian basin

NASA Astrophysics Data System (ADS)

Pamplona, Fábio Campos; Paes, Eduardo Tavares; Nepomuceno, Aguinaldo

2013-11-01

The temporal and spatial variability of dissolved inorganic nutrients (NO3-, NO2-, NH4+, PO43- and DSi), total nitrogen (TN), total phosphorus (TP), nutrient ratios, suspended particulate matter (SPM) and Chlorophyll-a (Chl-a) were evaluated for the macrotidal estuarine mangrove system of the Quatipuru river (QUATIES), east Amazon coast, North Brazil. Temporal variability was assessed by fortnightly sampling at a fixed station within the middle portion of the estuary, from November 2009 to November 2010. Spatial variability was investigated from two field surveys conducted in November 2009 (dry season) and May 2010 (rainy season), along the salinity gradient of the system. The average DIN (NO3- + NO2- + NH4+) concentration of 9 μM in the dry season was approximately threefold greater in comparison to the rainy season. NH4+ was the main form of DIN in the dry season, while NO3- predominated in the rainy season. The NH4+ concentrations in the water column during the dry season are largely attributed to release by tidal wash-out of the anoxic interstitial waters of the surficial mangrove sediments. On the other hand, the higher NO3- levels during the wet season, suggested that both freshwater inputs and nitrification processes in the water column acted in concert. The river PO43- concentrations (DIP < 1 μM) were low and similar throughout the year. DIN was thus responsible for the major temporal and spatial variability of the dissolved DIN:DIP (N:P) molar ratios and nitrogen corresponded, in general, to the prime limiting nutrient for the sustenance of phytoplankton biomass in the estuary. During the dry season, P-limitation was detected in the upper estuary. PO43- adsorption to SPM was detected during the rainy season and desorption during the dry season along the salinity gradient. In general, the average Chl-a level (14.8 μg L-1) was 2.5 times higher in the rainy season than in the dry season (5.9 μg L-1). On average levels reached maxima at about 14 km from the estuaries' mouth, but shifts of the maximum Chl-a zone were subject to a dynamic displacement influenced by the tidal regime and seasonality of freshwater input. Our results showed that the potential phytoplankton productivity in QUATIES was subject to temporal and spatial variability between N and P limitation. The mangrove forests also played a relevant role as a nutrient source as established by the high variability of the nutrient behaviour along the estuarine gradient, consequently affecting the productivity in QUATIES.

Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

USGS Publications Warehouse

Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

2014-01-01

Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side. Differences in microbial sulfate reduction, organic matter supply, and/or groundwater residence time likely contributed to this pattern. The contrasting features of the east and west sub-marsh zones highlight the need for multiple techniques for characterization of submarine groundwater discharge sources and the impact of biogeochemical processes on the delivery of nutrients and carbon to coastal areas via submarine groundwater discharge.

Nutrient Addition Leads to a Weaker CO2 Sink and Higher CH4 Emissions through Vegetation-Microclimate Feedbacks at Mer Bleue Bog, Canada

NASA Astrophysics Data System (ADS)

Bubier, J. L.; Arnkil, S.; Humphreys, E.; Juutinen, S.; Larmola, T.; Moore, T. R.

2015-12-01

Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands globally, affecting plant community composition, carbon (C) cycling, and microbial dynamics. Nutrient-limited boreal bogs are long-term sinks of carbon dioxide (CO2), but sources of methane (CH4), an important greenhouse gas. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, for 10-15 years with N as NO3 and NH4 at 5, 10 and 20 times ambient N deposition (0.6-0.8 g N m-2 y-1), with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured net ecosystem CO2 exchange (NEE), ecosystem photosynthesis and respiration, and CH4 flux with climate-controlled chambers; leaf-level CO2 exchange and biochemistry; substrate-induced respiration, CH4 production and consumption potentials with laboratory incubations; plant species composition and abundance; and microclimate (peat temperature, moisture, light interception). After 15 years, we have found that NEE has decreased, and CH4 emissions have increased, in the highest nutrient treatments owing to changes in vegetation, microtopography, and peat characteristics. Vegetation changes include a loss of Sphagnum moss and introduction of new deciduous species. Simulated atmospheric N deposition has not benefitted the photosynthetic apparatus of the dominant evergreen shrubs, but resulted in higher foliar respiration, contributing to a weaker ecosystem CO2 sink. Loss of moss has led to wetter near-surface substrate, higher rates of decomposition and CH4 emission, and a shift in microbial communities. Thus, elevated atmospheric deposition of nutrients may endanger C storage in peatlands through a complex suite of feedbacks and interactions among vegetation, microclimate, and microbial communities.

Nutrient intake in community-dwelling adolescent girls with anorexia nervosa and in healthy adolescents123

PubMed Central

Misra, Madhusmita; Tsai, Patrika; Anderson, Ellen J; Hubbard, Jane L; Gallagher, Katie; Soyka, Leslie A; Miller, Karen K; Herzog, David B; Klibanski, Anne

2011-01-01

Background Adolescence is a common time for the onset of anorexia nervosa (AN), a condition associated with long-term medical and hormonal consequences. Objective The objective was to compare the nutrient intakes of community-dwelling girls with AN with those of healthy adolescents and to describe the associations between specific nutrient intakes and nutritionally dependent hormones. Design Nutrient intakes in 39 community-dwelling girls with AN and 39 healthy adolescents aged 12.1–18.7 y were determined by using 4-d food records. Fasting adiponectin, leptin, ghrelin, insulin, and insulin-like growth factor I (IGF-I) concentrations were measured. Indirect calorimetry was used to assess respiratory quotient and resting energy expenditure. Results In contrast with the control group, the AN group consumed fewer calories from fats (P < 0.0001) and more from carbohydrates (P = 0.0009) and proteins (P < 0.0001). Intake of individual fat components was lower and of dietary fiber higher in the AN group. No significant between-group differences were observed in dietary intakes of calcium, zinc, and iron; however, total intake was greater in the AN group because of greater supplement use (P = 0.006, 0.02, and 0.01, respectively). The AN group had greater intakes of vitamins A, D, and K and of most of the B vitamins, and significantly more girls with AN met the Dietary Reference Intake for calcium (P = 0.01) and vitamin D (P = 0.02) from supplement use. Fat intake predicted ghrelin, insulin, and IGF-I concentrations; carbohydrate intake predicted adiponectin. Resting energy expenditure was lower (P < 0.0001) and leisure activity levels higher in the AN group. Conclusions Despite outpatient follow-up, community-dwelling girls with AN continue to have lower fat and higher fiber intakes than do healthy adolescents, which results in lower calorie intakes. Nutritionally related hormones are associated with specific nutrient intakes. PMID:17023694

Impacts of urban wastewater discharge on seagrass meadows ( Zostera noltii)

NASA Astrophysics Data System (ADS)

Cabaço, Susana; Machás, Raquel; Vieira, Vasco; Santos, Rui

2008-06-01

The abiotic disturbance of urban wastewater discharge and its effects in the population structure, plant morphology, leaf nutrient content, epiphyte load and macroalgae abundance of Zostera noltii meadows were investigated in Ria Formosa coastal lagoon, southern Portugal using both univariate and multivariate analysis. Four sites were assessed, on a seasonal basis, along a gradient from a major Waste Water Treatment Works (WWTW) discharge to a main navigation channel. The wastewater discharge caused an evident environmental disturbance through the nutrient enrichment of the water and sediment, particularly of ammonium. Zostera noltii of the sites closest to the nutrient source showed higher leaf N content, clearly reflecting the nitrogen load. The anthropogenic nutrient enrichment resulted in higher biomass, and higher leaf and internode length, except for the meadow closest to the wastewater discharge (270 m). The high ammonium concentration (158-663 μM) in the water at this site resulted in the decrease of biomass, and both the leaf and internode length, suggesting a toxic effect on Z. noltii. The higher abundance of macroalgae and epiphytes found in the meadow closest to the nutrient source may also affect the species negatively. Shoot density was higher at the nutrient-undisturbed site. Two of the three abiotic processes revealed by Principal Component Analysis were clearly related to the WWTW discharge, a contrast between water column salinity and nutrient concentration and a sediment contrast between both porewater nutrients and temperature and redox potential. A multiple regression analysis showed that these abiotic processes had a significant effect on the biomass-density dynamics of meadows and on the overall size of Z. noltii plants, respectively. Results show that the wastewater discharge is an important source of environmental disturbance and nutrients availability in Ria Formosa lagoon affecting the population structure, morphology and N content of Z. noltii. This impact is spatially restricted to areas up to 600 m distant from the WWTW discharge, probably due to the high water renewal of the lagoon.

An introduced predator alters Aleutian Island plant communities by thwarting nutrient subsidies

USGS Publications Warehouse

Maron, J.L.; Estes, J.A.; Croll, D.A.; Danner, E.M.; Elmendorf, S.C.; Buckelew, S.L.

2006-01-01

The ramifying effects of top predators on food webs traditionally have been studied within the framework of trophic cascades. Trophic cascades are compelling because they embody powerful indirect effects of predators on primary production. Although less studied, indirect effects of predators may occur via routes that are not exclusively trophic. We quantified how the introduction of foxes onto the Aleutian Islands transformed plant communities by reducing abundant seabird populations, thereby disrupting nutrient subsidies vectored by seabirds from sea to land. We compared soil and plant fertility, plant biomass and community composition, and stable isotopes of nitrogen in soil, plants, and other organisms on nine fox-infested and nine historically fox-free islands across the Aleutians. Additionally, we experimentally augmented nutrients on a fox-infested island to test whether differences in plant productivity and composition between fox-infested and fox-free islands could have arisen from differences in nutrient inputs between island types. Islands with historical fox infestations had soils low in phosphorus and nitrogen and plants low in tissue nitrogen. Soils, plants, slugs, flies, spiders, and bird droppings on these islands had low d15N values indicating that these organisms obtained nitrogen from internally derived sources. In contrast, soils, plants, and higher trophic level organisms on fox-free islands had elevated d15N signatures indicating that they utilized nutrients derived from the marine environment. Furthermore, soil phosphorus (but not nitrogen) and plant tissue nitrogen were higher on fox-free than fox-infested islands. Nutrient subsidized fox-free islands supported lush, high biomass plant communities dominated by graminoids. Fox-infested islands were less graminoid dominated and had higher cover and biomass of low-lying forbs and dwarf shrubs. While d15N profiles of soils and plants and graminoid biomass varied with island size and distance from shore, after accounting for these effects differences between fox-infested and fox-free islands still existed. Fertilization over four years caused a 24-fold increase in graminoid biomass and a shift toward a more graminoid dominated plant community typical of fox-free islands. These results indicate that apex predators can influence plant productivity and composition through complex interaction web pathways involving both top-down forcing and bottom-up nutrient exchanges across systems. ?? 2006 by the Ecological Society of America.

Nutrient budgets, marsh inundation under sea-level rise scenarios, and sediment chronologies for the Bass Harbor Marsh estuary at Acadia National Park

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Fuller, Christopher C.; Glibert, Patricia; Sturtevant, Luke

2014-01-01

Eutrophication in the Bass Harbor Marsh estuary on Mount Desert Island, Maine, is an ongoing problem manifested by recurring annual blooms of green macroalgae species, principally Enteromorpha prolifera and Enteromorpha flexuosa, blooms that appear in the spring and summer. These blooms are unsightly and impair the otherwise natural beauty of this estuarine ecosystem. The macroalgae also threaten the integrity of the estuary and its inherent functions. The U.S. Geological Survey and Acadia National Park have collaborated for several years to better understand the factors related to this eutrophication problem with support from the U.S. Geological Survey and National Park Service Water Quality Assessment and Monitoring Program. The current study involved the collection of hydrologic and water-quality data necessary to investigate the relative contribution of nutrients from oceanic and terrestrial sources during summer 2011 and summer 2012. This report provides data on nutrient budgets for this estuary, sedimentation chronologies for the estuary and fringing marsh, and estuary bathymetry. The report also includes data, based on aerial photographs, on historical changes from 1944 to 2010 in estuary surface area and data, based on surface-elevation details, on changes in marsh area that may accompany sea-level rise. The LOADEST regression model was used to calculate nutrient loads into and out of the estuary during summer 2011 and summer 2012. During these summers, tidal inputs of ammonium to the estuary were more than seven times greater than the combined inputs in watershed runoff and precipitation. In 2011 tidal inputs of nitrate were about four times greater than watershed plus precipitation inputs, and in 2012 tidal inputs were only slightly larger than watershed plus precipitation inputs. In 2011, tidal inputs of total organic nitrogen were larger than watershed input by a factor of 1.6. By contrast, in 2012 inputs of total organic nitrogen in watershed runoff were much larger than tidal inputs, by a factor of 3.6. During the 2011 and 2012 summers, tidal inputs of total dissolved phosphorus to the estuary were more than seven times greater than inputs in watershed runoff. It is evident that during the summer tidal inputs of inorganic nitrogen and total dissolved phosphorus to the estuary exceed inputs from watershed runoff and precipitation. Projected sea-level rise associated with ongoing climate warming will affect the area of land within the Bass Harbor Marsh estuary watershed that is inundated during conditions of mean higher high water and during mean lower low water and hence will affect the vegetation and marsh area. Given 100-centimeter sea-level rise, the inundated area would increase from 25.7 hectares at the current condition to 77.5 hectares at mean higher high water and from 21.6 hectares to 26.7 hectares at mean lower low water. Given 50-centimeter sea-level rise, flooding of the entire marsh surface, which currently occurs only under the highest spring tides, would occur on average every other day. Radioisotope analysis of sediment cores from the estuary indicates that the sediment accumulation rate increased markedly from 1930 to 1980 and was relatively constant (0.4 to 0.5 centimeter per year) from 1980 to 2009. Similarly, from 1980 to 2009 there was a consistently high mass accumulation rate of 0.09 to 0.11 grams per square centimeter per year. The sediment accretion rates determined for the five cores collected from the marsh surface (east and west sides of the estuary) in 2011 show generally higher rates of 0.20 to 0.29 centimeter per year for the period between 1980 to 2011 than for the period before 1980, when sediment accretion rates were 0.06 to 0.25 centimeter per year. The data in this report provide resource managers at Acadia National Park with a baseline that can be used to evaluate future conditions within the estuary. Climate change, sea-level rise, and land-use change within the estuary’s watershed may influence nutrient dynamics, sedimentation, and eutrophication, and these potential effects can be studied in relation to the baseline data provided in this report. The Route 102 Bridge in Tremont, Maine is constructed over a sill that controls the amount of tidal flushing by restricting the duration of the flood tide, and structural changes to the bridge could alter tidal nutrient inputs and residence times for watershed and ocean-derived nutrients in the estuary. Ongoing sea-level rise is likely increasing ocean-derived nutrients and their residence time in the estuary on the one hand and decreasing the residence time of watershed-derived nutrients on the other.

Decreasing reliance on mineral nitrogen--yet more food.

PubMed

Roy, Rabindra N; Misra, Ram V; Montanez, Adriana

2002-03-01

Higher crop production normally demands higher nutrient application rates and consequently increased mineral nitrogen use. With food demand for 2030 estimated around 2800 mill. tonnes (t) yr-1, the corresponding mineral N consumption figure is 96 mill. t (78 mill. t yr-1 in 1995/1997). Global-level mineral N losses to the environment from mineral fertilizer use are currently 36 mill. t yr-1, worth USD 11,700 mill. and with adverse environmental impacts. However, innovative fertilizer-use efficiency (FUE) technologies enable increased production with a less than a proportionate increase in mineral-N use. Moreover, nitrogen-nutrient supplies can be augmented through improvements in agricultural production systems and in the exploitation of alternative sources such as biological nitrogen fixation (BNF). By 2030, with adequate policy, technology transfer, research and investment support, the on-farm adoption of BNF and FUE technologies could generate savings of 10 mill. t yr-1 of mineral N, worth USD 3300 mill.

Effects of inclusion levels of pelleted silvergrass (Miscanthus sinensis Andress.) in the diet on digestibility, chewing activity, ruminal fermentation and blood metabolites in breeding Japanese Black cows.

PubMed

Asano, Keigo; Ishida, Miho; Ishida, Motohiko

2017-03-01

To examine the effects of inclusion levels of pelleted silvergrass (PS) in the diet on digestibility, ruminal fermentation and nutrient status of breeding Japanese Black cows, four cows were allotted to a 4 × 4 Latin square design experiment. Treatments were control fed a diet consisting of 89.4% Sudangrass hay and 10.6% soybean meal on a dry matter (DM) basis, and PS18, PS27 and PS45 fed the diet replaced with 18%, 27% and 45% of control with PS, respectively. The total digestible nutrients (TDN) content of PS was 45.6% on a DM basis. The TDN intakes were significantly decreased by increasing PS level in the diet (P < 0.05), but were higher than the TDN requirement of maintenance cows in all treatments. The total chewing time was decreased significantly by increasing PS level in the diets (P < 0.05). However, the pH and concentration of volatile fatty acid in the ruminal fluid and serum metabolite concentrations were not significantly different among the treatments. The results suggested that including PS up to 45% in the diet did not have adverse effects on the ruminal fermentation and nutrient status in breeding Japanese Black cows at the maintenance stage. © 2016 Japanese Society of Animal Science.

Responses of Spartina alterniflora to Multiple Stressors ...

EPA Pesticide Factsheets

Coastal wetlands, well recognized for their ecosystem services, have faced many threats throughout the United States and elsewhere. Managers require good information on responses of wetlands to the combined stressors that these habitats experience, or may in the future as a result of climate change, and few studies have explored the effect of multiple stressors on wetlands. We conducted a 4-month mesocosm study to analyze the multiple stressor effects of precipitation changes, sea level rise, and eutrophication on the salt marsh plant Spartina alterniflora. Pots containing plants in a soil matrix were positioned in tanks and received Narragansett Bay (RI) water. The mesocosms simulated three precipitation levels (ambient daily rain, biweekly storm, and drought); three elevation levels, low (15 cm below mean high water (MHW)), middle (MHW), and high (15 cm above MHW); and two nutrient enrichment levels (unenriched and nutrient-enriched bay water). Our results demonstrate storm and drought stressors led to significantly less above- and belowground biomass than those in ambient rain conditions. Plants that were flooded at the low elevation had less belowground biomass, fine roots, and S. alterniflora shoots. Nutrients had no detectable effect on total above- and belowground biomass, but the enriched pots had higher stem counts and more fine roots than unenriched pots, in addition to greater CO2 emission rates. However, the unenriched pots had significantly more co

[Mechanism of nutrient preservation and supply by soil and its regulation. IV. Fertility regulation and improvement of brown earth type vegetable garden soil and their essence].

PubMed

Chen, L; Zhou, L

2000-08-01

Pot experiment studies on the fertility regulation and improvement of fertile and infertile brown earth type vegetable garden soils and their functionary essence show that under conditions of taking different soil fertility improvement measures, the nutrient contents in fertile and infertile soils were not always higher than the controls, but the aggregation densities of soil microaggregates were increased, and the proportion of different microaggregates was more rational. There was no significant relationship between soil productivity and soil microaggregates proportion. It is proved that the essence of soil fertility improvement consists in the ultimate change of the preservation and supply capacities of soil nutrients, and the proportion of soil microaggregates could be an integrative index to evaluate the level of soil fertility and the efficiency of soil improvement.

Nutrient variations from swine manure to agricultural land

PubMed Central

You, Byung-Gu; Shim, Soomin; Choi, Yoon-Seok

2018-01-01

Objective Swine manure in Korea is separated into solid and liquid phases which are composted separately and then applied on land. The nutrient accumulation in soil has been a big issue in Korea but the basic investigation about nutrient input on arable land has not been achieved in detail. Within the nutrient production from livestock at the national level, most values are calculated by multiplication of the number of animals with the excreta unit per animal. However, the actual amount of nutrients from swine manure may be totally different with the nutrients applied to soil since livestock breeding systems are not the same with each country. Methods This study investigated 15 farms producing solid compost and 14 farms producing liquid compost. Composting for solid phase used the Turning+Aeration (TA) or Turning (T) only methods, while liquid phase aeration composting was achieved by continuous (CA), intermittent (IA), or no aeration (NA). Three scenarios were constructed for investigating solid compost: i) farm investigation, ii) reference study, and iii) theoretical P changes (ΔP = 0), whereas an experiment for water evaporation was conducted for analyzing liquid compost. Results In farm investigation, weight loss rates of 62% and 63% were obtained for TA and T, respectively, while evaporation rates for liquid compost were 8.75, 7.27, and 5.14 L/m2·d for CA, IA, and NA, respectively. Farm investigation provided with the combined nutrient load (solid+liquid) of VS, N, and P of 117.6, 7.2, and 2.7 kg/head·yr. Nutrient load calculated from farm investigation is about two times higher than the calculated with reference documents. Conclusion The nutrient loading coefficients from one swine (solid+liquid) were (volatile solids, 0.79; nitrogen, 0.53; phosphorus, 0.71) with nutrient loss of 21%, 47%, and 29%, respectively. The nutrient count from livestock manure using the excretion unit has probably been overestimated without consideration of the nutrient loss. PMID:29268574

NF-κB Immunity in the Brain Determines Fly Lifespan in Healthy Aging and Age-Related Neurodegeneration.

PubMed

Kounatidis, Ilias; Chtarbanova, Stanislava; Cao, Yang; Hayne, Margaret; Jayanth, Dhruv; Ganetzky, Barry; Ligoxygakis, Petros

2017-04-25

During aging, innate immunity progresses to a chronically active state. However, what distinguishes those that "age well" from those developing age-related neurological conditions is unclear. We used Drosophila to explore the cost of immunity in the aging brain. We show that mutations in intracellular negative regulators of the IMD/NF-κB pathway predisposed flies to toxic levels of antimicrobial peptides, resulting in early locomotor defects, extensive neurodegeneration, and reduced lifespan. These phenotypes were rescued when immunity was suppressed in glia. In healthy flies, suppressing immunity in glial cells resulted in increased adipokinetic hormonal signaling with high nutrient levels in later life and an extension of active lifespan. Thus, when levels of IMD/NF-κB deviate from normal, two mechanisms are at play: lower levels derepress an immune-endocrine axis, which mobilizes nutrients, leading to lifespan extension, whereas higher levels increase antimicrobial peptides, causing neurodegeneration. Immunity in the fly brain is therefore a key lifespan determinant. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Landscape influence on soil carbon and nutrient levels

USDA-ARS?s Scientific Manuscript database

Past runoff, erosion, and management practices influence nutrient levels on the landscape. These starting levels affect future nutrient transport due to runoff, erosion, and leaching events. The purpose of this study was to examine closed-depression landscape effects on surface soil organic matter, ...

Higher trophic level affects nutrient, silicon, metal(loid), and radionuclide mobilization from freshwater sediments

NASA Astrophysics Data System (ADS)

Schaller, Jörg; Planer-Friedrich, Britta

2017-04-01

Organic sediments in aquatic ecosystems are well known sinks for nutrients, silicon, and metal(loid)s. Organic matter-decomposing organisms like invertebrate shredders, grazers, bioturbators, and filter feeder are key-species for the carbon and energy turnover within the decomposer community. We could show that invertebrate shredders and grazer affect element fixation or remobilization by changing binding properties of organic sediments and the attached biofilm. Bioturbators affect element fixation or remobilization by changing redox conditions within the uppermost sediment layer. Last but not least filter feeders, like the zebra mussel Dreissena polymorpha, an invasive organism in North American and European freshwater ecosystems significantly contributed to element mobilization of silicon, iron, phosphorus, arsenic, and copper and to immobilization of uranium (p<0.001), probably driven by redox conditions, microbial activity within the gut system, or active control of element homeostasis. Except of the filter feeder D. polymorpha, the invertebrates are able to minimize the accumulation of non-nutrient elements due to specific strategies, which is an important strategy for species living in systems tending to element accumulation. However, D. polymorpha revealed a significant uptake and accumulation of arsenic, copper, iron, and especially uranium both into the soft body tissues and the seashell. This accumulation by D. polymorpha is in line with previous observations of metal(loid) accumulation from biomonitoring studies. In summary, higher trophic level strongly contributes to element fixation or remobilization in aquatic systems.

Interactive effects of redox intensity and phosphate availability on growth and nutrient relations of Cladium jamaicense (Cyperaceae)

USGS Publications Warehouse

Lissner, J.; Mendelssohn, I.A.; Lorenzen, B.; Brix, H.; McKee, K.L.; Miao, S.L.

2003-01-01

Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as redox potential (Eh). The objective of this study was to assess the growth response of C. jamaicense to Eh (-150, +150, and +600 mV) and P availability (10, 80, and 500 ??g P/L). Plants were grown hydroponically in a factorial experiment using titanium (Ti3+) citrate as an Eh buffer. Treatment effects on growth, biomass partitioning, and tissue nutrients were recorded. Growth approximately doubled in response to a 50-fold increase in P availability. Low redox significantly reduced growth and tissue P concentration. While plant P concentrations increased 20-fold between the 10 and 500 ??g P/L treatments, P concentrations were 50-100% higher at +600 mV than at -150 mV within each phosphate level. At high Eh, C. jamaicense appears well adapted to low nutrient environments because of its low P requirement and high retention of acquired E However, at low Eh the ability to acquire or conserve acquired P decreases and as a consequence, higher phosphate levels are required to sustain growth. Findings of this study indicate that young C. jamaicense exhibits low tolerance to strongly reducing conditions when phosphate is scarce.

Nutritional Evaluation of NASA's Rodent Food Bar Diet

NASA Technical Reports Server (NTRS)

Barrett, Joyce E.; Yu, Diane S.; Dalton, Bonnie P.

2000-01-01

Tests are being conducted on NASA's rodent Food Bar in preparation for long-term use as the rat and mouse diet aboard the International Space Station. Nutritional analyses are performed after the bars are manufactured and then repeated periodically to determine nutritional stability. The primary factors analyzed are protein, ash, fat, fiber, moisture, amino acids, fatty acids, and minerals. Nutrient levels are compared to values published in the National Research Council's dietary requirements for rodents, and also to those contained in several commonly used commercial rodent lab diets. The Food Bar is manufactured from a powdered diet to which moisture is added as it is processed through an extruder. The bars are dipped into potassium sorbate, vacuum-sealed, and irradiated. In order to determine nutrient changes during extrusion and irradiation, the powdered diet, the non-irradiated bars, and the irradiated bars are all analyzed. We have observed lower values for some nutrients (iodine, vitamin K, and iron) in the Food Bars compared with NRC requirements. Many nutrients in the Food Bars are contained at a higher level than levels in the NRC requirements. An additional factor we are investigating is the 26% moisture level in the Food Bars, which drops to about 15% within a week, compared to a stable 10% moisture in many standard lab chow diets. In addition to the nutritional analyses, the food bar is being fed to several strains of rats and mice, and feeding study and necropsy results are being observed (Barrett et al, unpublished data). Information from the nutritional analyses and from the rodent studies will enable us to recommend the formulation that will most adequately meet the rodent Food Bar requirements for long-term use aboard the Space Station.

A comparison of algal, macroinvertebrate, and fish assemblage indices for assessing low-level nutrient enrichment in wadeable Ozark streams

USGS Publications Warehouse

Justus, B.G.; Petersen, J.C.; Femmer, S.R.; Davis, J.V.; Wallace, J.E.

2010-01-01

Biotic indices for algae, macroinvertebrates, and fish assemblages can be effective for monitoring stream enrichment, but little is known regarding the value of the three assemblages for detecting perturbance as a consequence of low-level nutrient enrichment. In the summer of 2006, we collected nutrient and biotic samples from 30 wadeable Ozark streams that spanned a nutrient-concentration gradient from reference to moderately enriched conditions. Seventy-three algal metrics, 62 macroinvertebrate metrics, and 60 fish metrics were evaluated for each of the three biotic indices. After a group of candidate metrics had been identified with multivariate analysis, correlation procedures and scatter plots were used to identify the four metrics having strongest relations to a nutrient index calculated from log transformed and normalized total nitrogen and total phosphorus concentrations. The four metrics selected for each of the three biotic indices were: algae-the relative abundance of most tolerant diatoms, the combined relative abundance of three species of Cymbella, mesosaprobic algae percent taxa richness, and the relative abundance of diatoms that are obligate nitrogen heterotrophs; macroinvertebrate-the relative abundance of intolerant organisms, Baetidae relative abundance, moderately tolerant taxa richness, and insect biomass; fish-herbivore and detritivore taxa richness, pool species relative abundance, fish catch per unit effort, and black bass (Micropterus spp.) relative abundance. All three biotic indices were negatively correlated to nutrient concentrations but the algal index had a higher correlation (rho = -0.89) than did the macroinvertebrate and fish indices (rho = -0.63 and -0.58, respectively). Biotic index scores were lowest and nutrient concentrations were highest for streams with basins having the highest poultry and cattle production. Because of the availability of litter for fertilizer and associated increases in grass and hay production, cattle feeding capacity increases with poultry production. Studies are needed that address the synergistic effect of poultry and cattle production on Ozark streams in high production areas before ecological risks can be adequately addressed.

Nutrient intake values (NIVs): a recommended terminology and framework for the derivation of values.

PubMed

King, Janet C; Vorster, Hester H; Tome, Daniel G

2007-03-01

Although most countries and regions around the world set recommended nutrient intake values for their populations, there is no standardized terminology or framework for establishing these standards. Different terms used for various components of a set of dietary standards are described in this paper and a common set of terminology is proposed. The recommended terminology suggests that the set of values be called nutrient intake values (NIVs) and that the set be composed of three different values. The average nutrient requirement (ANR) reflects the median requirement for a nutrient in a specific population. The individual nutrient level (INLx) is the recommended level of nutrient intake for all healthy people in the population, which is set at a certain level x above the mean requirement. For example, a value set at 2 standard deviations above the mean requirement would cover the needs of 98% of the population and would be INL98. The third component of the NIVs is an upper nutrient level (UNL), which is the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in a specified life-stage group. The proposed framework for deriving a set of NIVs is based on a statistical approach for determining the midpoint of a distribution of requirements for a set of nutrients in a population (the ANR), the standard deviation of the requirements, and an individual nutrient level that assures health at some point above the mean, e.g., 2 standard deviations. Ideally, a second set of distributions of risk of excessive intakes is used as the basis for a UNL.

Effect of eco-remediation using planted floating bed system on nutrients and heavy metals in urban river water and sediment: a field study in China.

PubMed

Ning, Daliang; Huang, Yong; Pan, Ruisong; Wang, Fayuan; Wang, Hui

2014-07-01

To investigate the effect of the eco-remediation on nutrients and heavy metals in river water and sediment, a field study was carried out in a site of a 2-year eco-remediation mainly using planted floating bed system in an urban river in China. Before remediation, the tested properties of water and sediment in the will-be remediated area were not different from the control area, except higher concentrations of chemical oxygen demand (COD) and total nitrogen (TN) in the river water. After remediation, the remediation area showed effective removal of in-stream nutrients and elevation of dissolved oxygen and transparency. Compared to the control area, the remediation area had higher concentration of nitrate and lower concentrations of COD, ammonium, Mn and hexavalent Cr in the river water after a 2-year remediation. The remediation area also showed higher concentrations of organic carbon, TN, nitrate, sulfate, Fe, Cu, Pb and Zn in the sediment than in the control area. Accordingly, special attention should be paid to the ecological risk of heavy metals in sediments and plants in river eco-remediation projects especially in rivers polluted by heavy metals, although the metals were lower than the level of considerable ecological risk in this study. Copyright © 2014 Elsevier B.V. All rights reserved.

Contributions of processed foods to dietary intake in the US from 2003-2008: a report of the Food and Nutrition Science Solutions Joint Task Force of the Academy of Nutrition and Dietetics, American Society for Nutrition, Institute of Food Technologists, and International Food Information Council.

PubMed

Eicher-Miller, Heather A; Fulgoni, Victor L; Keast, Debra R

2012-11-01

Processed foods are an integral part of American diets, but a comparison of the nutrient contribution of foods by level of processing with the recommendations of the Dietary Guidelines for Americans regarding nutrients to encourage or to reduce has not been documented. The mean reported daily dietary intakes of these nutrients and other components were examined among 25,351 participants ≥2 y of age in the 2003-2008 NHANES to determine the contribution of processed food to total intakes. Also examined was the percent contribution of each nutrient to the total reported daily nutrient intake for each of the 5 categories of food that were defined by the level of processing. All processing levels contributed to nutrient intakes, and none of the levels contributed solely to nutrients to be encouraged or solely to food components to be reduced. The processing level was a minor determinant of individual foods' nutrient contribution to the diet and, therefore, should not be a primary factor when selecting a balanced diet.

Including spatial data in nutrient balance modelling on dairy farms

NASA Astrophysics Data System (ADS)

van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

2017-04-01

The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies at Dutch dairy farms. We selected two dairy farms located on cover sands in the Netherlands. One farm was located on relatively homogeneous soil type, and one on many different soil types within the sandy soils. A full year of data of N and P inputs and outputs on farm and field level were provided by the farmers, including field level yields, yield composition, manure composition, degree of grazing and degree of mowing. Soil heterogeneity was defined as the number of soil units within the farm corrected for surface area, and quantified from the Dutch 1:50.000 soil map. N and P balances at farm and field level were determined, as well as differences in nutrient use efficiency, leaching, and N emission. We will present the effect of the spatial scale on nutrient balance analysis and discuss to which degree any differences are caused by within-farm land management and soil variation. This study highlights to which extent within-farm land management and soil variation should be taken into account when modelling nutrient flows and nutrient use efficiencies at farm level, to contribute to field-based decision making for improved land management.

Submesoscale Flows and Mixing in the Ocean Surface Layer Using the Regional Oceanic Modeling System (ROMS)

DTIC Science & Technology

2013-09-30

chemical cycles, water quality, blooms , micro-nutrients, larval dispersal, biome transitions, and coupling to higher tropic levels. We collaborate with...Kurian, 2012: Heat balance and eddies in the Peru- Chile Current System. Climate Dynamics 39, 509-529, doi:10.1007/s00382-011-1170-6. Colas, F., X

Foxtail Millet [Setaria italica (L.) Beauv.] Grown under Low Nitrogen Shows a Smaller Root System, Enhanced Biomass Accumulation, and Nitrate Transporter Expression.

PubMed

Nadeem, Faisal; Ahmad, Zeeshan; Wang, Ruifeng; Han, Jienan; Shen, Qi; Chang, Feiran; Diao, Xianmin; Zhang, Fusuo; Li, Xuexian

2018-01-01

Foxtail millet (FM) [ Setaria italica (L.) Beauv.] is a grain and forage crop well adapted to nutrient-poor soils. To date little is known how FM adapts to low nitrogen (LN) at the morphological, physiological, and molecular levels. Using the FM variety Yugu1, we found that LN led to lower chlorophyll contents and N concentrations, and higher root/shoot and C/N ratios and N utilization efficiencies under hydroponic culture. Importantly, enhanced biomass accumulation in the root under LN was in contrast to a smaller root system, as indicated by significant decreases in total root length; crown root number and length; and lateral root number, length, and density. Enhanced carbon allocation toward the root was rather for significant increases in average diameter of the LN root, potentially favorable for wider xylem vessels or other anatomical alterations facilitating nutrient transport. Lower levels of IAA and CKs were consistent with a smaller root system and higher levels of GA may promote root thickening under LN. Further, up-regulation of SiNRT1.1, SiNRT2.1, and SiNAR2.1 expression and nitrate influx in the root and that of SiNRT1.11 and SiNRT1.12 expression in the shoot probably favored nitrate uptake and remobilization as a whole. Lastly, more soluble proteins accumulated in the N-deficient root likely as a result of increases of N utilization efficiencies. Such "excessive" protein-N was possibly available for shoot delivery. Thus, FM may preferentially transport carbon toward the root facilitating root thickening/nutrient transport and allocate N toward the shoot maximizing photosynthesis/carbon fixation as a primary adaptive strategy to N limitation.

Rising nutrient-pulse frequency and high UVR strengthen microbial interactions

PubMed Central

Cabrerizo, Marco J.; Medina-Sánchez, Juan Manuel; Dorado-García, Irene; Villar-Argaiz, Manuel; Carrillo, Presentación

2017-01-01

Solar radiation and nutrient pulses regulate the ecosystem’s functioning. However, little is known about how a greater frequency of pulsed nutrients under high ultraviolet radiation (UVR) levels, as expected in the near future, could alter the responses and interaction between primary producers and decomposers. In this report, we demonstrate through a mesocosm study in lake La Caldera (Spain) that a repeated (press) compared to a one-time (pulse) schedule under UVR prompted higher increases in primary (PP) than in bacterial production (BP) coupled with a replacement of photoautotrophs by mixotrophic nanoflagellates (MNFs). The mechanism underlying these amplified phytoplanktonic responses was a dual control by MNFs on bacteria through the excretion of organic carbon and an increased top-down control by bacterivory. We also show across a 6-year whole-lake study that the changes from photoautotrophs to MNFs were related mainly to the frequency of pulsed nutrients (e.g. desert dust inputs). Our results underscore how an improved understanding of the interaction between chronic and stochastic environmental factors is critical for predicting ongoing changes in ecosystem functioning and its responses to climatically driven changes. PMID:28252666

Rising nutrient-pulse frequency and high UVR strengthen microbial interactions

NASA Astrophysics Data System (ADS)

Cabrerizo, Marco J.; Medina-Sánchez, Juan Manuel; Dorado-García, Irene; Villar-Argaiz, Manuel; Carrillo, Presentación

2017-03-01

Solar radiation and nutrient pulses regulate the ecosystem’s functioning. However, little is known about how a greater frequency of pulsed nutrients under high ultraviolet radiation (UVR) levels, as expected in the near future, could alter the responses and interaction between primary producers and decomposers. In this report, we demonstrate through a mesocosm study in lake La Caldera (Spain) that a repeated (press) compared to a one-time (pulse) schedule under UVR prompted higher increases in primary (PP) than in bacterial production (BP) coupled with a replacement of photoautotrophs by mixotrophic nanoflagellates (MNFs). The mechanism underlying these amplified phytoplanktonic responses was a dual control by MNFs on bacteria through the excretion of organic carbon and an increased top-down control by bacterivory. We also show across a 6-year whole-lake study that the changes from photoautotrophs to MNFs were related mainly to the frequency of pulsed nutrients (e.g. desert dust inputs). Our results underscore how an improved understanding of the interaction between chronic and stochastic environmental factors is critical for predicting ongoing changes in ecosystem functioning and its responses to climatically driven changes.

Succession of microbial communities and changes of incremental oil in a post-polymer flooded reservoir with nutrient stimulation.

PubMed

Gao, Peike; Li, Guoqiang; Le, Jianjun; Liu, Xiaobo; Liu, Fang; Ma, Ting

2018-02-01

Further exploitation of the residual oil underground in post-polymer flooded reservoirs is attractive and challengeable. In this study, indigenous microbial enhanced oil recovery (IMEOR) in a post-polymer flooded reservoir was performed. The succession of microbial communities was revealed by high-throughput sequencing of 16S rRNA genes and changes of incremental oil were analyzed. The results indicated that the abundances of reservoir microorganisms significantly increased, with alpha diversities decreased in the IMEOR process. With the intermittent nutrient injection, microbial communities showed a regular change and were alternately dominated by minority populations: Pseudomonas and Acinetobacter significantly increased when nutrients were injected; Thauera, Azovibrio, Arcobacter, Helicobacter, Desulfitobacterium, and Clostridium increased in the following water-flooding process. Accompanied by the stimulated populations, higher oil production was obtained. However, these populations did not contribute a persistent level of incremental oil in the reservoir. In summary, this study revealed the alternative succession of microbial communities and the changes of incremental oil in a post-polymer flooded reservoir with intermittent nutrient stimulation process.

Food selection by the silver leaf monkey,Trachypithecus auratus sondaicus, in relation to plant chemistry.

PubMed

Kool, K M

1992-07-01

Samples of leaves and fruits exploited as food items byTrachypithecus auratus sondaicus were analysed for nitrogen content, acid detergent fibre (ADF), pepsin cellulase digestibility (CDIG), condensed tannins (CT), total phenolics (TP) and protein precipitation capacity (PP) and compared with fruits and leaves not eaten. Differences in chemical measures for items eaten and not eaten were not statistically significant but trends indicate that leaves may have been selected for their lower fibre content and greater digestibility. Fruits eaten also had a higher mean level of CDIG and lower mean level of ADF than fruits not eaten but these measures are not considered to be of major importance in fruit selection as CDIG was lower and ADF higher in fruits eaten than in leaves eaten. Levels of CT, TP and PP capacity were higher in fruits eaten than in fruits not eaten but lower in leaves eaten than in leaves not eaten. The role of tannins and phenolics in food selection is discussed. Leaves (and fruits) were not strongly selected on the basis of protein content. Approximately half the dietary intake ofT. auratus sondaicus was leaves, a protein-rich food source. Possibly, protein levels in foliage at Pangandaran were sufficient that selection for this nutrient was not required. A nutrient other than protein (for example, soluble carbohydrates) may have been maximised through food selection. The protein/ADF ratio may provide an indicator of the acceptability of foliage in a habitat as potential food for a colobine. However, this ratio did not govern food selection byT. auratus sondaicus at Pangandaran.

Adequacy of nutritional intake among older men living in Sydney, Australia: findings from the Concord Health and Ageing in Men Project (CHAMP).

PubMed

Waern, Rosilene V R; Cumming, Robert G; Blyth, Fiona; Naganathan, Vasi; Allman-Farinelli, Margaret; Le Couteur, David; Simpson, Stephen J; Kendig, Hal; Hirani, Vasant

2015-09-14

Previous research shows that older men tend to have lower nutritional intakes and higher risk of under-nutrition compared with younger men. The objectives of this study were to describe energy and nutrient intakes, assess nutritional risk and investigate factors associated with poor intake of energy and key nutrients in community-dwelling men aged ≥75 years participating in the Concord Health and Ageing in Men Project - a longitudinal cohort study on older men in Sydney, Australia. A total of 794 men (mean age 81·4 years) had a detailed diet history interview, which was carried out by a dietitian. Dietary adequacy was assessed by comparing median intakes with nutrient reference values (NRV): estimated average requirement, adequate intake or upper level of intake. Attainment of NRV of total energy and key nutrients in older age (protein, Fe, Zn, riboflavin, Ca and vitamin D) was incorporated into a 'key nutrients' variable dichotomised as 'good' (≥5) or 'poor' (≤4). Using logistic regression modelling, we examined associations between key nutrients with factors known to affect food intake. Median energy intake was 8728 kJ (P5=5762 kJ, P95=12 303 kJ), and mean BMI was 27·7 (sd 4·0) kg/m2. Men met their NRV for most nutrients. However, only 1 % of men met their NRV for vitamin D, only 19 % for Ca, only 30 % for K and only 33 % for dietary fibre. Multivariate logistic regression analysis showed that only country of birth was significantly associated with poor nutritional intake. Dietary intakes were adequate for most nutrients; however, only half of the participants met the NRV of ≥5 key nutrients.

ENSO-driven nutrient variability recorded by central equatorial Pacific corals

NASA Astrophysics Data System (ADS)

LaVigne, M.; Nurhati, I. S.; Cobb, K. M.; McGregor, H. V.; Sinclair, D. J.; Sherrell, R. M.

2012-12-01

Recent evidence for shifts in global ocean primary productivity suggests that surface ocean nutrient availability is a key link between global climate and ocean carbon cycling. Time-series records from satellite, in situ buoy sensors, and bottle sampling have documented the impact of the El Niño Southern Oscillation (ENSO) on equatorial Pacific hydrography and broad changes in biogeochemistry since the late 1990's, however, data are sparse prior to this. Here we use a new paleoceanographic nutrient proxy, coral P/Ca, to explore the impact of ENSO on nutrient availability in the central equatorial Pacific at higher-resolution than available from in situ nutrient data. Corals from Christmas (157°W 2°N) and Fanning (159°W 4°N) Islands recorded a well-documented decrease in equatorial upwelling as a ~40% decrease in P/Ca during the 1997-98 ENSO cycle, validating the application of this proxy to Pacific Porites corals. We compare the biogeochemical shifts observed through the 1997-98 event with two pre-TOGA-TAO ENSO cycles (1982-83 and 1986-87) reconstructed from a longer Christmas Island core. All three corals revealed ~30-40% P/Ca depletions during ENSO warming as a result of decreased regional wind stress, thermocline depth, and equatorial upwelling velocity. However, at the termination of each El Niño event, surface nutrients did not return to pre-ENSO levels for ~4-12 months after, SST as a result of increased biological draw down of surface nutrients. These records demonstrate the utility of high-resolution coral nutrient archives for understanding the impact of tropical Pacific climate on the nutrient and carbon cycling of this key region.

Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet

PubMed Central

Price, Charles T; Langford, Joshua R; Liporace, Frank A

2012-01-01

Osteoporosis and low bone mineral density affect millions of Americans. The majority of adults in North America have insufficient intake of vitamin D and calcium along with inadequate exercise. Physicians are aware that vitamin D, calcium and exercise are essential for maintenance of bone health. Physicians are less likely to be aware that dietary insufficiencies of magnesium, silicon, Vitamin K, and boron are also widely prevalent, and each of these essential nutrients is an important contributor to bone health. In addition, specific nutritional factors may improve calcium metabolism and bone formation. It is the authors’ opinion that nutritional supplements should attempt to provide ample, but not excessive, amounts of factors that are frequently insufficient in the typical American diet. In contrast to dietary insufficiencies, several nutrients that support bone health are readily available in the average American diet. These include zinc, manganese, and copper which may have adverse effects at higher levels of intake. Some multivitamins and bone support products provide additional quantities of nutrients that may be unnecessary or potentially harmful. The purpose of this paper is to identify specific nutritional components of bone health, the effects on bone, the level of availability in the average American diet, and the implications of supplementation for each nutritional component. A summary of recommended dietary supplementation is included. PMID:22523525

Effects of chito-oligosaccharide supplementation on performance, nutrient digestibility, and serum composition in broiler chickens.

PubMed

Li, X J; Piao, X S; Kim, S W; Liu, P; Wang, L; Shen, Y B; Jung, S C; Lee, H S

2007-06-01

A total of 196 day-old male broiler chicks were randomly allocated to 1 of 4 treatments in a study conducted to determine the effects of dietary supplementation of chito-oligosaccharide (COS) on growth, nutrient digestibility, and serum composition. The experimental diets consisted of an unsupplemented control diet based on corn, soybean meal, and fish meal or similar diets supplemented with either chlortetracycline, 50 mg/kg of COS, or 100 mg/kg of COS. Each treatment was fed to 7 replicate pens of birds, with 7 birds per pen. Broiler performance, nutrient digestibility, cecal microbial concentrations, and serum indices were measured at the end of the starter (d 21) and grower phases (d 42). During the starter period and overall, broilers fed 50 or 100 mg/kg of COS had better (P<0.05) average daily gain, average daily feed intake, and feed conversion than the control birds. The performance of birds fed chlortetracycline was generally intermediate between that of the control and the 2 COS treatments. Compared with the birds in the control or chlortetracycline treatments, the birds receiving 100 mg/kg of COS had better nutrient digestibility of DM, energy, calcium, and phosphorus; higher (P<0.05) concentrations of cecal Lactobacillus; and lower (P<0.05) serum triglyceride and total cholesterol during the starter phase. During the grower phase, the birds fed 100 mg/kg of COS had higher (P<0.05) calcium digestibility and CP retention than those fed the chlortetracycline treatment, and lower concentrations of cecal Escherichia coli than birds in the control treatment. The serum growth hormone level in birds fed 50 mg/kg of COS was higher (P<0.05) than in the other treatments. The birds fed 100 mg/kg of COS had lower (P<0.05) serum triglyceride, higher (P<0.05) serum high-density lipoprotein cholesterol, and higher serum total protein content than birds in the other treatments. In conclusion, dietary supplementation with COS appeared to improve the average daily gain of broilers by increasing the average daily feed intake and nutrient digestibility and modulating the concentrations of cecal microbial flora. Additionally, COS increased serum protein and high-density lipoprotein cholesterol and decreased serum triglyceride.

Analysis of bacterial diversity in two oil blocks from two low-permeability reservoirs with high salinities.

PubMed

Xiao, Meng; Sun, Shan-Shan; Zhang, Zhong-Zhi; Wang, Jun-Ming; Qiu, Long-Wei; Sun, Hua-Yang; Song, Zhao-Zheng; Zhang, Bei-Yu; Gao, De-Li; Zhang, Guang-Qing; Wu, Wei-Min

2016-01-20

The community diversities of two oil reservoirs with low permeability of 1.81 × 10(-3) and 2.29 × 10(-3) μm(2) in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly.

Exoenzyme activity in contaminated soils before and after soil washing: ß-glucosidase activity as a biological indicator of soil health.

PubMed

Chae, Yooeun; Cui, Rongxue; Woong Kim, Shin; An, Gyeonghyeon; Jeong, Seung-Woo; An, Youn-Joo

2017-01-01

It is essential to remediate or amend soils contaminated with various heavy metals or pollutants so that the soils may be used again safely. Verifying that the remediated or amended soils meet soil quality standards is an important part of the process. We estimated the activity levels of eight soil exoenzymes (acid phosphatase, arylsulfatase, catalase, dehydrogenase, fluorescein diacetate hydrolase, protease, urease, and ß-glucosidase) in contaminated and remediated soils from two sites near a non-ferrous metal smelter, using colorimetric and titrimetric determination methods. Our results provided the levels of activity of soil exoenzymes that indicate soil health. Most enzymes showed lower activity levels in remediated soils than in contaminated soils, with the exception of protease and urease, which showed higher activity after remediation in some soils, perhaps due to the limited nutrients available in remediated soils. Soil exoenzymes showed significantly higher activity in soils from one of the sites than from the other, due to improper conditions at the second site, including high pH, poor nutrient levels, and a high proportion of sand in the latter soil. Principal component analysis revealed that ß-glucosidase was the best indicator of soil ecosystem health, among the enzymes evaluated. We recommend using ß-glucosidase enzyme activity as a prior indicator in estimating soil ecosystem health. Copyright © 2016 Elsevier Inc. All rights reserved.

Response to carbohydrate and fat refeeding in the expression of genes involved in nutrient partitioning and metabolism: striking effects on fibroblast growth factor-21 induction.

PubMed

Sánchez, J; Palou, A; Picó, C

2009-12-01

This study aimed to assess the effects of carbohydrate (CHO) and fat intake on the expression of key genes related with nutrient partitioning and metabolism in main tissues involved in energy metabolism (white adipose tissue, liver, and skeletal muscle). Rats were studied under different conditions: feeding state, 24 h fasting, and 12 h refeeding after 24 h fasting with isocaloric amounts of CHO or fat. Fat, but not CHO, refeeding was associated with an increase in serum and liver triglyceride content. Main changes in gene expression elicited by CHO compared with fat refeeding were: 1) higher expression levels of genes related with lipogenesis (PPARgamma2, ChREBP, FAS), glucose uptake and metabolism (GLUT4, HKII), fatty acid uptake (LPL, CD36), and lipolysis (ATGL, HSL) in white adipose tissue; 2) higher expression levels of genes related with lipogenesis (FAS, SCD1) but lower ones related with fatty acid uptake (CD36) and oxidation (PPARalpha, CPT1, PDK4) in liver; and 3) higher expression levels of GLUT4 but lower ones related with fatty acid oxidation (PDK4 and UCP3) in muscle. It is worth mentioning that both CHO and fat refeeding resulted in a robust increase in both hepatic mRNA and circulating levels of fibroblast growth factor-21, compared with fasted levels. In summary, these results, showing marked differences in gene expression after CHO and fat refeeding, can explain diet-associated differences in fuel handling and partitioning between tissues; in addition, a role of fibroblast growth factor-21 in metabolic adaptations, not only in the ketotic state but also to face an unbalanced nutritional situation, is suggested.

Impact of nitrogen source and supply level on growth, yield and nutritional value of two contrasting ecotypes of Cichorium spinosum L. grown hydroponically.

PubMed

Chatzigianni, Martina; Alkhaled, Bara'a; Livieratos, Ioannis; Stamatakis, Aristidis; Ntatsi, Georgia; Savvas, Dimitrios

2018-03-01

In the present study, two contrasting stamnagathi (Cichorium spinosum L.) ecotypes originating either from a mountainous or from a seaside habitat were grown hydroponically and supplied with a nutrient solution differing in the total-N level (4 or 16 mmol L -1 ) and the N source (NH 4 + -N/total-N: 0.05, 0.25 or 0.50). The aim was to search for genotypic differences in nitrogen nutrition. At commercial maturity, the dry weight of mountainous plants was higher than that of seaside plants. The shoot mineral concentrations were higher in seaside plants than in mountainous plants in both harvests. The leaf nitrate concentration was influenced by the levels of both total-N and NH 4 + -N/total-N at both harvests, whereas plants with a seaside origin exhibited higher nitrate concentrations than those originating from a mountainous site in all total-N and NH 4 + -N/total-N treatments. The two stamnagathi ecotypes differed considerably in their responses to nitrogen nutrition and tissue nitrate content. The mountainous ecotype was superior in terms of growth, tissue nitrate concentration and antioxidant capacity, whereas the seaside ecotype accumulated more nutrient microcations in leaves. A low total-N concentration (up to 4 mmol L -1 ) combined with a high NH 4 + -N/total-N ratio (up to 0.05) could minimize tissue NO 3 - concentrations without compromising yield. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Possible mechanism linking ocean conditions to low body weight and poor recruitment of age-0 walleye pollock (Gadus chalcogrammus) in the southeast Bering Sea during 2007

NASA Astrophysics Data System (ADS)

Gann, Jeanette C.; Eisner, Lisa B.; Porter, Steve; Watson, Jordan T.; Cieciel, Kristin D.; Mordy, Calvin W.; Yasumiishi, Ellen M.; Stabeno, Phyllis J.; Ladd, Carol; Heintz, Ron A.; Farley, Edward V.

2016-12-01

Changes to physical and chemical oceanographic structure can lead to changes in phytoplankton biomass and growth, which, in-turn, lead to variability in the amount of energy available for transfer to higher trophic levels (e.g., forage fish). In general, age-0 (juvenile) walleye pollock (Gadus chalcogrammus) have been shown to have low fitness (determined by energy density and size), in warm years compared to average or cold years in the southeastern Bering Sea. Contrary to these findings, the year 2007 was a cold year with low fitness of age-0 pollock compared to the transition year of 2006 (transitioning from warm to cold conditions) and cold years, 2008-2011. In late summer/early fall (mid-August through September), significantly lower surface silicic acid concentrations coupled with low phytoplankton production and chlorophyll a (Chl a) biomass were observed in 2007 among 2006-2012 (P<0.05). We postulate that the low silicic acid concentrations may be an indication of reduced surface nutrient flux during summer, leading to low primary productivity (PP). The nutrient replenishing shelf/slope water exchange that occurred during late October-February (2006-2007) indicates that deep-water nutrient/salinity reserves for the start of the 2007 growing season were plentiful and had similar concentrations to other years (2006-2012). The spring bloom magnitude appeared to be slightly below average, and surface silicic acid concentrations at the end of the spring bloom period in 2007 appeared similar to other years in the middle domain of the southeastern Bering Sea. However, during summer (June-August) 2007, high stratification and the low number of storm events resulted in low flux of nutrients to surface waters, indicated by the low surface silicic acid concentrations at the end of summer (mid-August through September). Surface silicic acid may be useful as an indicator of surface nutrient enrichment (and subsequent PP) during summer since other macronutrients (e.g. nitrate) are usually near or below detection limits at this time, and diatoms are generally scarce during summer. Surface silicic acid concentration was also positively associated with the size of juvenile fish (age-0 pollock weight and length). This reinforces the theory that nutrient availability and primary productivity are important to energy allocation for higher trophic levels during summer, and possibly provides links between stratification and wind mixing, surface nutrient input, PP and juvenile fish size and condition.

Environmental Impact Assessment of Shrimp Culture Practice in Southwest Coastal Region of Bangladesh

NASA Astrophysics Data System (ADS)

Islam, M. M.; Rouf, M. A.; Hambrey, J.

2008-12-01

The rapid unplanned expansion of coastal aquaculture in Bangladesh poses risks in degrading environment. The unsustainable aquaculture practices are suspected to impart significant nutrient load to the ecosystem. Nevertheless, shrimp production is very less and susceptible to sever mortality. For this, the study aimed to understand the management practices and nutrient flux from some represented shrimp ponds in southwest coastal region of Bangladesh. A comprehensive study from 2002 to 2004 was done in an aquatic system comprising a river (Semi diurnal tidal system), a canal and 10 shrimp ponds along with wider area survey to verify the issues under a DFID-funded research project involving Nautilus Consultants Ltd. (UK). In the study area (Dumuria under the district Khulna) shrimp culture practices were mostly improved extensive. Shrimp were being produced without proper pond preparation, fry nursing, stocking or feed management due to lack of technical somehow and the risks involved with higher levels of investment. Consequently production rates were very low, averaging only 191 Kg/ha. Very high mortality of shrimp was reported in some of the farms using shallow ponds immediately after heavy rainfall. This may due to the sudden fluctuation of water pH and/or water temperature and salinity. The water quality in shrimp ponds during grow out period was in acceptable range except lower trend of DO and ammonia nitrogen. Year round water quality observations indicated that there were no major differences among the river, canal and pond water that might be due to the high water flushing rate (468%). The nutrient dynamics estimation indicates that 48.7 kg/ha/cycle of nitrogen and 28.96 kg/ha/cycle of phosphorus were added to the pond as an input mostly from fertilizer and feed. Among the inputs, only 33.4% of nitrogen and 6% of phosphorus were removed as harvested form. A large portion, 39.1% N and 92% P were remained in the sediments and unaccounted for. Average intake of nutrients through supply water was slightly higher than nutrient discharged through water outlet, which indicates a net retention of nutrients in the pond ecosystems. A large portion of this sediment nutrient eventually finds its routes into the wider aquatic system every year during pond preparation. Though the aquatic environment is able to accommodate the load from the present level of aquaculture practice, the assimilative power of aquatic environment is in danger of being degraded with the unplanned intensification of shrimp culture areas. In planning aquaculture and future development all the issues and impacts must be considered.

Nutrient fluxes at the landscape level and the R* rule

USGS Publications Warehouse

Ju, Shu; DeAngelis, Donald L.

2010-01-01

Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.

Flower litters of alpine plants affect soil nitrogen and phosphorus rapidly in the eastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, Jinniu; Xu, Bo; Wu, Yan; Gao, Jing; Shi, Fusun

2016-10-01

Litters of reproductive organs have rarely been studied despite their role in allocating nutrients for offspring reproduction. This study determines the mechanism through which flower litters efficiently increase the available soil nutrient pool. Field experiments were conducted to collect plant litters and calculate biomass production in an alpine meadow of the eastern Tibetan Plateau. C, N, P, lignin, cellulose content, and their relevant ratios of litters were analyzed to identify their decomposition features. A pot experiment was performed to determine the effects of litter addition on the soil nutrition pool by comparing the treated and control samples. The litter-bag method was used to verify decomposition rates. The flower litters of phanerophyte plants were comparable with non-flower litters. Biomass partitioning of other herbaceous species accounted for 10-40 % of the aboveground biomass. Flower litter possessed significantly higher N and P levels but less C / N, N / P, lignin / N, and lignin and cellulose concentrations than leaf litter. The litter-bag experiment confirmed that the flower litters of Rhododendron przewalskii and Meconopsis integrifolia decompose approximately 3 times faster than mixed litters within 50 days. Pot experiment findings indicated that flower litter addition significantly increased the available nutrient pool and soil microbial productivity. The time of litter fall significantly influenced soil available N and P, and soil microbial biomass. Flower litters fed the soil nutrition pool and influenced nutrition cycling in alpine ecosystems more efficiently because of their non-ignorable production, faster decomposition rate, and higher nutrient contents compared with non-flower litters. The underlying mechanism can enrich nutrients, which return to the soil, and non-structural carbohydrates, which feed and enhance the transitions of soil microorganisms.

Performance of broiler chickens fed diets supplemented with a direct-fed microbial.

PubMed

Angel, R; Dalloul, R A; Doerr, J

2005-08-01

From hatch to 18 d of age broilers were fed starter diets with (0.9 kg/ton) or without direct fed microbial (DFM). At 18 d, birds were weighed and, within DFM treatment (trt), randomly assigned to battery pens. In Exp 1, a 2 x 2 factorial arrangement of nutrient density [control (C, 19.3% protein (CP), 0.84%, Ca 0.37% nonphytin P (nPP); and 17.1% CP, 0.8% Ca, and 0.3% nPP in the grower (Gr) and finisher (Fn) diets, respectively) and moderate (M) (17% CP, 0.69% Ca, 0.30% nPP; 15% CP, 0.66% Ca, 0.25% nPP in the Gr and Fn diets, respectively)] and DFM concentration [0 or 0.9 kg/ton (++)] was used. Exp 2 was a 2 (DSM at 0 and 0.45 kg/ton) x 3 (nutrient densities) factorial. Exp 2 included a low (L) nutrient density that differed from diet M only in Ca and nPP concentrations and an added trt, diet M with 0.45 kg/ ton DFM as in Exp 1. At the end of the Gr and Fn weight, feed efficiency, apparent nutrient retention were determined, and 4 birds per pen were sampled for tibia ash. In Exp 2, gains in the Gr phase were 1,122.0, 983.7, 1,121.5, 930.7, and 1,151.5 g in birds fed the C, M, M+, L, and L+ diets, respectively. Addition of DFM to the M diet overcame the negative effect of nutrient concentration on performance but not when the L diet was fed. Nutrient level and DFM affected apparent protein, Ca, and P retention at 32 or 42 d of age with retention increasing as nutrient level decreased and with DFM added to the diet. Ca and P retention at 28 d (Exp 1) was higher in birds fed M++ (45.8 and 46%, respectively) than in those fed the C diet (38.7 and 40.0%, respectively). Feeding the M and L diets resulted in lower tibia ash than that of birds fed the C diet, but the addition of DFM to low nutrient diets overcame this negative effect.

Effects of sea-level rise and freshwater management on long-term water levels and water quality in the Florida Coastal Everglades.

PubMed

Dessu, Shimelis B; Price, René M; Troxler, Tiffany G; Kominoski, John S

2018-04-01

Since the 1880s, hydrological modification of the Greater Florida Everglades has reduced water levels and flows in Everglades National Park (ENP). The Comprehensive Everglades Restoration Program (CERP) began in 2000 to restore pre-drainage flows and preserve the natural landscape of the Everglades. However, sea-level rise (SLR) was not considered in the development of CERP. We used long-term data (2001-2016) from the Florida Coastal Everglades-Long Term Ecological Research Program to quantify and model the spatial dynamics of water levels, salinity, and nutrients in response to changes in climate, freshwater management and SLR in the Shark River Slough (SRS), ENP. Results indicate that fresh-to-marine head difference (FMHD) was the single most important factor affecting marine-to-freshwater hydrologic connectivity and transport of salinity and phosphorous upstream from the Gulf of Mexico. Sea-level has increasingly exceeded ground surface elevation at the most downstream freshwater site in SRS, thereby reducing the FMHD. We showed a higher impact of SLR in the dry season when there was practically no freshwater inflow to raise FMHD. We also demonstrated effectiveness of inflow depends more on the monthly distribution than the total annual volume. Hence, the impact per unit volume of inflow is significantly higher in the dry season in preventing high salinity and marine-derived nutrient levels. We advocate that FMHD needs to be factored into water management decisions to reduce adverse and likely irreversible effects of SLR throughout the Everglades landscape. Published by Elsevier Ltd.

Substitution of common concentrates with by-products modulated ruminal fermentation, nutrient degradation, and microbial community composition in vitro.

PubMed

Ertl, P; Knaus, W; Metzler-Zebeli, B U; Klevenhusen, F; Khiaosa-Ard, R; Zebeli, Q

2015-07-01

A rumen simulation technique was used to evaluate the effects of the complete substitution of a common concentrate mixture (CON) with a mixture consisting solely of by-products from the food industry (BP) at 2 different forage-to-concentrate ratios on ruminal fermentation profile, nutrient degradation, and abundance of rumen microbiota. The experiment was a 2×2 factorial arrangement with 2 concentrate types (CON and BP) and 2 concentrate levels (25 and 50% of diet dry matter). The experiment consisted of 2 experimental runs with 12 fermentation vessels each (n=6 per treatment). Each run lasted for 10d, with data collection on the last 5d. The BP diets had lower starch, but higher neutral detergent fiber (NDF) and fat contents compared with CON. Degradation of crude protein was decreased, but NDF and nonfiber carbohydrate degradation were higher for the BP diets. At the 50% concentrate level, organic matter degradation tended to be lower for BP and CH4 formation per unit of NDF degraded was also lower for BP. The BP mixture led to a higher concentration of propionate and a lower acetate-to-propionate ratio, whereas concentrations of butyrate and caproate decreased. Concentrate type did not affect microbial community composition, except that the abundance of bacteria of the genus Prevotella was higher for BP. Increasing the concentrate level resulted in higher degradation of organic matter and crude protein. At the higher concentrate level, total short-chain fatty acid formation increased and concentrations of isobutyrate and valerate decreased. In addition, at the 50% concentrate level, numbers of protozoa increased, whereas numbers of methanogens, anaerobic fungi, and fibrolytic bacteria decreased. No interaction was noted between the 2 dietary factors on most variables, except that at the higher concentrate level the effects of BP on CH4 and CO2 formation per unit of NDF degraded, crude protein degradation, and the abundance of Prevotella were more prominent. In conclusion, the results of this study suggest that BP in the diet can adequately substitute CON with regard to ruminal fermentation profile and microbiota, showing even favorable fermentation patterns when fed at 50% inclusion rate. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Menu variations for diabetes mellitus patients using Goal Programming model

NASA Astrophysics Data System (ADS)

Dhoruri, Atmini; Lestari, Dwi; Ratnasari, Eminugroho

2017-08-01

Diabetes mellitus (DM) was a chronic metabolic disease characterized by higher than normal blood glucose level (normal blood glucose level = = 80 -120 mg/dl). In this study, type 2 DM which mostly caused by unhealthy eating habits would be investigated. Related to eating habit, DM patients needed dietary menu planning with an extracare regarding their nutrients intake (energy, protein, fat and carbohydrate). Therefore, the measures taken were by organizing nutritious dietary menu for diabetes mellitus patients. Dietary menu with appropriate amount of nutrients was organized by considering the amount of calories, proteins, fats and carbohydrates. In this study, Goal Programming model was employed to determine optimal dietary menu variations for diabetes mellitus patients by paying attention to optimal expenses. According to the data obtained from hospitals in Yogyakarta, optimal menu variations would be analyzed by using Goal Programming model and would be completed by using LINGO computer program.

Food habits and nutrient density of diets of Pakistani children living in different urban and rural settings.

PubMed

Hakeem, Rubina; Thomas, Jane; Badruddin, Salma H

2002-09-01

Food habits and nutrient density of diets of six groups of rural and urban school children aged 10-12 years were compared. Data were collected from three-day food records. In the UK, data were collected during October-November 1994 and in Pakistan during April-May 1995. Based on the apparent level of urbanism, the six groups were arbitrarily assigned urbanization rank 1-6. Patterns of their food and intake of nutrients were different from each other in various aspects and were not always associated with the apparent level of urbanism of the group. With urbanization, the intake of fat and sugar increased steadily. The intake of carbohydrate, fibre, riboflavin, and vitamin E decreased with urbanization. The intake of vitamin C, vitamin B12, and folates was higher among group 4, 5, and 6 than other groups. Due to various factors, in terms of micronutrient density, diets of various urban groups could have more differences than similarities. While these differences point toward the need for comprehensive nutrition education and community nutrition surveys, they also indicate the possibility of having healthy diets in urban settings.

The rise of algae in Cryogenian oceans and the emergence of animals

NASA Astrophysics Data System (ADS)

Brocks, Jochen J.; Jarrett, Amber J. M.; Sirantoine, Eva; Hallmann, Christian; Hoshino, Yosuke; Liyanage, Tharika

2017-08-01

The transition from dominant bacterial to eukaryotic marine primary productivity was one of the most profound ecological revolutions in the Earth’s history, reorganizing the distribution of carbon and nutrients in the water column and increasing energy flow to higher trophic levels. But the causes and geological timing of this transition, as well as possible links with rising atmospheric oxygen levels and the evolution of animals, remain obscure. Here we present a molecular fossil record of eukaryotic steroids demonstrating that bacteria were the only notable primary producers in the oceans before the Cryogenian period (720-635 million years ago). Increasing steroid diversity and abundance marks the rapid rise of marine planktonic algae (Archaeplastida) in the narrow time interval between the Sturtian and Marinoan ‘snowball Earth’ glaciations, 659-645 million years ago. We propose that the incumbency of cyanobacteria was broken by a surge of nutrients supplied by the Sturtian deglaciation. The ‘Rise of Algae’ created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.

The rise of algae in Cryogenian oceans and the emergence of animals.

PubMed

Brocks, Jochen J; Jarrett, Amber J M; Sirantoine, Eva; Hallmann, Christian; Hoshino, Yosuke; Liyanage, Tharika

2017-08-31

The transition from dominant bacterial to eukaryotic marine primary productivity was one of the most profound ecological revolutions in the Earth's history, reorganizing the distribution of carbon and nutrients in the water column and increasing energy flow to higher trophic levels. But the causes and geological timing of this transition, as well as possible links with rising atmospheric oxygen levels and the evolution of animals, remain obscure. Here we present a molecular fossil record of eukaryotic steroids demonstrating that bacteria were the only notable primary producers in the oceans before the Cryogenian period (720-635 million years ago). Increasing steroid diversity and abundance marks the rapid rise of marine planktonic algae (Archaeplastida) in the narrow time interval between the Sturtian and Marinoan 'snowball Earth' glaciations, 659-645 million years ago. We propose that the incumbency of cyanobacteria was broken by a surge of nutrients supplied by the Sturtian deglaciation. The 'Rise of Algae' created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.

Nutrients, Antioxidant Capacity and Safety of Hot Water Extract from Sugar Maple (Acer saccharum M.) and Red Maple (Acer rubrum L.) Bark.

PubMed

Bhatta, Sagar; Ratti, Cristina; Poubelle, Patrice E; Stevanovic, Tatjana

2018-03-01

Sugar maple (Acer saccharum M.) and red maple (Acer rubrum L.) barks were treated with hot water to extract nutrients in order to explore, for the first time, its potential as safe dietary antioxidants. The organic and inorganic nutrients of these extracts, as well as their safety on human PLB-985 cells differentiated into neutrophils-like cells, were determined. Proximate analysis showed that both bark extracts were low in moisture and fat. Sugar maple bark extract (SM-BX) showed crude protein and ash content higher than those found in red maple bark extract (RM-BX). In addition, SM-BX had total sugars higher than those evaluated in RM-BX, while complex sugars (oligo- and/or poly-saccharides) were similarly abundant in both bark extracts. Furthermore, SM-BX demonstrated a wide array of vital minerals (K, Ca, Mg, P, Na, Fe and Cu) in quantity larger than that evaluated in RM-BX, whereas RM-BX have Zn and Mn levels higher than those found in SM-BX. Phytochemical analyses showed that RM-BX exhibited total phenolic and flavonoid contents higher than those measured in SM-BX. Consequently, RM-BX presented an antioxidant activity higher than that of SM-BX: 2.85-fold ABTS radical cation scavenging capacity and 1.9-fold oxygen radical absorbance capacity. Finally, RM-BX and SM-BX were greatly safe since, at concentration up to 100 μg/ml, they did not modify the viability of neutrophils as determined by flow-cytometry assay using Annexin V-FITC/Propidum Iodide as markers. In conclusion, our in vitro studies indicate that both red and sugar maple bark extracts have a real potential as food additives.

Selection for high muscle fat in rainbow trout induces potentially higher chylomicron synthesis and PUFA biosynthesis in the intestine.

PubMed

Kamalam, Biju Sam; Panserat, Stephane; Aguirre, Peyo; Geurden, Inge; Fontagné-Dicharry, Stéphanie; Médale, Françoise

2013-02-01

Two lines of rainbow trout divergently selected for muscle fat content, fat line (F) and lean line (L) were used to investigate the effect of genetic selection on digestion, intestinal nutrient transport and fatty acid bioconversion, in relation to dietary starch intake. This study involved a digestibility trial for 2 weeks using Cr(2)O(3) as inert marker, followed by a feeding trial for 4 weeks. For the entire duration, juvenile trout from the two lines were fed diets with or without gelatinized starch. Blood, pyloric ceca, midgut and hindgut were sampled at 24 h after the last meal. Transcripts of the proteins involved in nutrient transport and fatty acid bioconversion were abundant in the proximal intestine. GLUT2 transcripts were slightly higher in the F line ceca than in the L line. Dietary starch intake did not enhance the transcription of intestinal glucose transporters, SGLT1 and GLUT2; but it was associated with the higher expression of ApoA1 and PepT1 in the midgut. Significantly, the F line exhibited higher intestinal mRNA levels of MTP, ApoA4, Elovl2, Elovl5 and D6D than the L line, linked to chylomicron assembly and fatty acid bioconversion. Apparent digestibility coefficients of protein, lipid and starch were high in both lines, but not significantly different between them. In conclusion, we found a higher potential of chylomicron synthesis and fatty acid bioconversion in the intestine of F line, but no adaptive transcriptional response of glucose transporters to dietary starch and no genotypic differences in nutrient digestibility. Copyright © 2012 Elsevier Inc. All rights reserved.

Higher photosynthesis, nutrient- and energy-use efficiencies contribute to invasiveness of exotic plants in a nutrient poor habitat in northeast China.

PubMed

Liu, Ming-Chao; Kong, De-Liang; Lu, Xiu-Rong; Huang, Kai; Wang, Shuo; Wang, Wei-Bin; Qu, Bo; Feng, Yu-Long

2017-08-01

The roles of photosynthesis-related traits in invasiveness of introduced plant species are still not well elucidated, especially in nutrient-poor habitats. In addition, little effort has been made to determine the physiological causes and consequences of the difference in these traits between invasive and native plants. To address these problems, we compared the differences in 16 leaf functional traits related to light-saturated photosynthetic rate (P max ) between 22 invasive and native plants in a nutrient-poor habitat in northeast China. The invasive plants had significantly higher P max , photosynthetic nitrogen- (PNUE), phosphorus- (PPUE), potassium- (PKUE) and energy-use efficiencies (PEUE) than the co-occurring natives, while leaf nutrient concentrations, construction cost (CC) and specific leaf area were not significantly different between the invasive and native plants. The higher PNUE contributed to higher P max for the invasive plants, which in turn contributed to higher PPUE, PKUE and PEUE. CC changed independently with other traits such as P max , PNUE, PPUE, PKUE and PEUE, showing two trait dimensions, which may facilitate acclimation to multifarious niche dimensions. Our results indicate that the invasive plants have a superior resource-use strategy, i.e. higher photosynthesis under similar resource investments, contributing to invasion success in the barren habitat. © 2017 Scandinavian Plant Physiology Society.

Cost-Effectiveness Analysis of Surface Flow Constructed Wetlands (SFCW) for Nutrient Reduction in Drainage Discharge from Agricultural Fields in Denmark.

PubMed

Gachango, F G; Pedersen, S M; Kjaergaard, C

2015-12-01

Constructed wetlands have been proposed as cost-effective and more targeted technologies in the reduction of nitrogen and phosphorous water pollution in drainage losses from agricultural fields in Denmark. Using two pig farms and one dairy farm situated in a pumped lowland catchment as case studies, this paper explores the feasibility of implementing surface flow constructed wetlands (SFCW) based on their cost effectiveness. Sensitivity analysis is conducted by varying the cost elements of the wetlands in order to establish the most cost-effective scenario and a comparison with the existing nutrients reduction measures carried out. The analyses show that the cost effectiveness of the SFCW is higher in the drainage catchments with higher nutrient loads. The range of the cost effectiveness ratio on nitrogen reduction differs distinctively with that of catch crop measure. The study concludes that SFCW could be a better optimal nutrients reduction measure in drainage catchments characterized with higher nutrient loads.

Nutrient losses from timber harvesting in a larch/ Douglas-fir forest

Treesearch

Nellie M. Stark

1979-01-01

Nutrient levels as a result of experimental clearcutting, shelterwood cutting, and group selection cutting - each with three levels of harvesting intensity - were studied in a larchfir forest in northwest Montana, experimentally logged with a skyline system. None of the treatments altered nutrient levels in an intermittent stream, nor were excessive amounts of...

Biogeochemistry of the Amazon River Basin: the role of aquatic ecosystems in the Amazon functioning

NASA Astrophysics Data System (ADS)

Victoria, R. L.; Ballester, V. R.; Krushe, A. V.; Richey, J. E.; Aufdenkampe, A. K.; Kavaguishi, N. L.; Gomes, B. M.; Victoria, D. D.; Montebello, A. A.; Niell, C.; Deegan, L.

2004-12-01

In this study we present the results of an integrated analysis of physical and anthropogenic controls of river biogeochemistry in Amazônia. At the meso-scale level, our results show that both soil properties and land use are the main drivers of river biogeochemistry and metabolism, with pasture cover and soil exchange cation capacity explaining 99% (p < 0.01) of the variability observed in surface water ions and nutrients concentrations. In small rivers, forest clearing can increase cations, P and C inputs. P and light are the main PPL limiting factors in forested streams, while in pasture streams N becomes limiting. P export to streams may increase or remain nearly undetectable after forest-to-pasture conversion, depending on soil type. Pasture streams on Oxisols have very low P export, while on Ultisols P export is increased. Conversions of forest to pasture leads to extensive growth of in channel Paspalum resulting in higher DOC concentrations and respiration rates. Pasture streams have higher DOC fluxes when compared to the forest ones. In pasture areas the soil are compacted, there is less infiltration and higher surface run off, leaching soil superficial layers and caring more DOC to the streams. In forest areas infiltration is deeper into the soils and canopy interaction is higher. Mineralogy and soil properties are key factors determining exports of nutrients to streams. Therefore, land use change effects on nutrient export from terrestrial to aquatic ecosystems and the atmosphere must be understood within the context of varying soil properties across the Amazon Basin.

Quantifying Temporal Autocorrelations for the Expression of Geobacter species mRNA Gene Transcripts at Variable Ammonium Levels during in situ U(VI) Bioremediation

NASA Astrophysics Data System (ADS)

Mouser, P. J.

2010-12-01

In order to develop decision-making tools for the prediction and optimization of subsurface bioremediation strategies, we must be able to link the molecular-scale activity of microorganisms involved in remediation processes with biogeochemical processes observed at the field-scale. This requires the ability to quantify changes in the in situ metabolic condition of dominant microbes and associate these changes to fluctuations in nutrient levels throughout the bioremediation process. It also necessitates a need to understand the spatiotemporal variability of the molecular-scale information to develop meaningful parameters and constraint ranges in complex bio-physio-chemical models. The expression of three Geobacter species genes (ammonium transporter (amtB), nitrogen fixation (nifD), and a housekeeping gene (recA)) were tracked at two monitoring locations that differed significantly in ammonium (NH4+) concentrations during a field-scale experiment where acetate was injected into the subsurface to simulate Geobacteraceae in a uranium-contaminated aquifer. Analysis of amtB and nifD mRNA transcript levels indicated that NH4+ was the primary form of fixed nitrogen during bioremediation. Overall expression levels of amtB were on average 8-fold higher at NH4+ concentrations of 300 μM or more than at lower NH4+ levels (average 60 μM). The degree of temporal correlation in Geobacter species mRNA expression levels was calculated at both locations using autocorrelation methods that describe the relationship between sample semi-variance and time lag. At the monitoring location with lower NH4+, a temporal correlation lag of 8 days was observed for both amtB and nifD transcript patterns. At the location where higher NH4+ levels were observed, no discernable temporal correlation lag above the sampling frequency (approximately every 2 days) was observed for amtB or nifD transcript fluctuations. Autocorrelation trends in recA expression levels at both locations indicated that while a temporal correlation in the general metabolic activity of Geobacter species may exist, considerable variability in transcript levels masked these correlations at the sampled scale. These findings suggest that when Geobacter species are dependent upon a particular nutrient such as NH4+, the time length for which their activity level relating to this nutrient condition can be predicted is significantly enhanced.

Ethnic disparities among food sources of energy and nutrients of public health concern and nutrients to limit in adults in the United States: NHANES 2003-2006.

PubMed

O'Neil, Carol E; Nicklas, Theresa A; Keast, Debra R; Fulgoni, Victor L

2014-01-01

Identification of current food sources of energy and nutrients among US non-Hispanic whites (NHW), non-Hispanic blacks (NHB), and Mexican American (MA) adults is needed to help with public health efforts in implementing culturally sensitive and feasible dietary recommendations. The objective of this study was to determine the food sources of energy and nutrients to limit [saturated fatty acids (SFA), added sugars, and sodium] and nutrients of public health concern (dietary fiber, vitamin D, calcium, and potassium) by NHW, NHB, and MA adults. This was a cross-sectional analysis of a nationally representative sample of NWH (n=4,811), NHB (2,062), and MA (n=1,950) adults 19+ years. The 2003-2006 NHANES 24-h recall (Day 1) dietary intake data were analyzed. An updated USDA Dietary Source Nutrient Database was developed using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. Multiple differences in intake among ethnic groups were seen for energy and all nutrients examined. For example, energy intake was higher in MA as compared to NHB; SFA, added sugars, and sodium intakes were higher in NHW than NHB; dietary fiber was highest in MA and lowest in NHB; vitamin D was highest in NHW; calcium was lowest in NHB; and potassium was higher in NHW as compared to NHB. Food sources of these nutrients also varied. Identification of intake of nutrients to limit and of public health concern can help health professionals implement appropriate dietary recommendations and plan interventions that are ethnically appropriate.

Nutrient cycling in Nothofagus pumilio forests along an altitudinal gradient in Tierra del Fuego, Argentina

Treesearch

Jorge L. Frangi; Marcelo D. Barrera; Laura L. Richter; Ariel E. Lugo

2005-01-01

Nothofagus pumilio (lenga) forests form monocultures from sea level to timberline in Tierra de Fuego, Argentina. Past studies suggested that the life form change from erect forest to krummholz had advantages to forest function. Aboveground net primary productivity (NPP) and organic matter production per unit leaf area and growing season day were higher in krummholz...

Stimulatory effects of aluminum on growth of sugar maple seedlings

Treesearch

George A. Schier; Carolyn J. McQuattie

2002-01-01

To determine the effect of aluminum (Al) on sugar maple (Acer saccharum Marsh.), seedlings were grown in sand irrigated with nutrient solution (pH 3.8) containing 0, 2.5, 5, 10, 20, or 40 mg L-1 Al. Seedling growth was enhanced at 2.5 and 5mgL-1 Al. Although higher levels of Al reduced calcium (Ca) and...

Water Quality in Big Cypress National Preserve and Everglades National Park - Trends and Spatial Characteristics of Selected Constituents

USGS Publications Warehouse

Miller, Ronald L.; McPherson, Benjamin F.; Sobczak, Robert; Clark, Christine

2004-01-01

Seasonal changes in water levels and flows in Big Cypress National Preserve (BICY) and Everglades National Park (EVER) affect water quality. As water levels and flows decline during the dry season, physical, geochemical and biological processes increase the breakdown of organic materials and the build-up of organic waste, nutrients, and other constituents in the remaining surface water. For example, concentrations of total phosphorus in the marsh are less than 0.01 milligram per liter (mg/L) during much of the year. Concentrations can rise briefly above this value during the dry season and occasionally exceed 0.1 mg/L under drought conditions. Long-term changes in water levels, flows, water management, and upstream land use also affect water quality in BICY and EVER, based on analysis of available data (1959-2000). During the 1980's and early 1990's, specific conductance and concentrations of chloride increased in the Taylor Slough and Shark River Slough. Chloride concentrations more than doubled from 1960 to 1990, primarily due to greater canal transport of high dissolved solids into the sloughs. Some apparent long-term trends in sulfate and total phosphorus were likely attributable, at least in part, to high percentages of less-than and zero values and to changes in reporting levels over the period of record. High values in nutrient concentrations were evident during dry periods of the 1980's and were attributable either to increased canal inflows of nutrient-rich water, increased nutrient releases from breakdown of organic bottom sediment, or increased build-up of nutrient waste from concentrations of aquatic biota and wildlife in remaining ponds. Long-term changes in water quality over the period of record are less pronounced in the western Everglades and the Big Cypress Swamp; however, short-term seasonal and drought-related changes are evident. Water quality varies spatially across the region because of natural variations in geology, hydrology, and vegetation and because of differences in water management and land use. Nutrient concentrations are relatively low in BICY and EVER compared with concentrations in parts of the northern Everglades that are near agricultural and urban lands. Concentrations of total phosphorus generally are higher in BICY (median values, 1991-2000, were mostly greater than 0.015 mg/L) than in EVER (median values, 1991-2000, less than 0.01 mg/L), probably because of higher phosphorus in natural sources such as shallow soils, rocks, and ground water in the Big Cypress region than in the Everglades region. Conversely, concentrations of chloride and sulfate are higher in EVER (median values in Shark River Slough, 1991-2000, mostly greater than 2 mg/L sulfate and 50 mg/L chloride) than in BICY (median values, 1991-2000, less than 1 mg/L sulfate and at most sites less than 20 mg/L chloride), probably because of the canal transport system, which conveys more water from an agricultural source into EVER than into BICY. Trace elements and contaminants such as pesticides and other toxic organic compounds are in relatively low concentrations in BICY and EVER compared with concentrations in parts of the northern Everglades near agricultural and urban sources. Concentrations rarely exceeded aquatic life criteria in BICY and EVER. Atrazine was the only pesticide found in water that exceeded the criteria (in 2 out of 304 samples). The pesticides heptachlor expoxide, lindane, and p,p?-DDE exceeded criteria in canal bed sediments in 1, 2, and 16 percent of the samples, respectively.

Effects of epiphytic algae on biomass and physiology of Myriophyllum spicatum L. with the increase of nitrogen and phosphorus availability in the water body.

PubMed

Song, Yu-Zhi; Wang, Jin-Qi; Gao, Yong-Xia

2017-04-01

The disappearance of submerged vascular macrophytes in shallow eutrophic lakes is a common phenomenon in the world. To explore the mechanism of the decline in submerged macrophyte abundance due to the growth of epiphytic algae along a nutrient gradient in eutrophic water, a 2 × 3 factorial experiment was performed over 4 weeks with the submerged macrophyte (Myriophyllum spicatum L.) by determining the plant's biomass and some physiological indexes, such as chlorophyll (Chl) content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in the leaves of M. spicatum L. on days 7, 14, 21, and 28, which are based on three groups of nitrogen and phosphorus levels in the water body (N-P [mg L -1 ]: NP1 0.5-0.05, NP2 2.5-0.25, NP3 4.5-0.45) and two levels of epiphytic algae (the epiphytic algae group and the control group). Epiphytic algal biomass was also assayed. The results indicated that epiphytic algal biomass remarkably enhanced in the course of the experiment with elevated levels of nitrogen and phosphorus in the water. Under the same level of nutrient condition, plants' biomass accumulation and Chl content were higher in the control group than that in the epiphytic algae group, respectively, while MDA content and SOD activity in the former were lower than that in the latter. The influences of epiphytic algae on the biomass accumulation and Chl content and MDA content became greater and greater with elevated levels of nutrients. In general, in this experiment, water nutrients promoted the growth of both epiphytic algae and submerged plants, while the growth of epiphytic algae hindered submerged macrophytes' growth by reducing Chl content and promoting peroxidation of membrane lipids in plants.

Variation in defence strategies in two species of the genus Beilschmiedia under differing soil nutrient and rainfall conditions.

PubMed

Simon, J; Miller, R E; Woodrow, I E

2007-01-01

The relationships between various leaf functional traits that are important in plant growth (e.g., specific leaf area) have been investigated in recent studies; however, research in this context on plants that are highly protected by chemical defences, particularly resource-demanding nitrogen-based defence, is lacking. We collected leaves from cyanogenic (N-defended) Beilschmiedia collina B. Hyland and acyanogenic (C-defended) Beilschmiedia tooram (F. M. Bailey) B. Hyland at high- and low-soil nutrient sites in two consecutive years that varied significantly in rainfall. We then measured the relationships between chemical defence and morphological and functional leaf traits under the different environmental conditions. We found that the two species differed significantly in their resource allocation to defence as well as leaf morphology and function. The N defended species had a higher leaf nitrogen concentration, whereas the C-defended species had higher amounts of C-based chemical defences (i.e., total phenolics and condensed tannins). The C-defended species also tended to have higher force to fracture and increased leaf toughness. In B. collina, cyanogenic glycoside concentration was higher with higher rainfall, but not with higher soil nutrients. Total phenolic concentration was higher at the high soil nutrient site in B. tooram, but lower in B. collina; however, with higher rainfall an increase was found in B. tooram, while phenolics decreased in B. collina. Condensed tannin concentration decreased in both species with rainfall and nutrient availability. We conclude that chemical defence is correlated with leaf functional traits and that variation in environmental resources affects this correlation.

Two Salix Genotypes Differ in Productivity and Nitrogen Economy When Grown in Monoculture and Mixture

PubMed Central

Hoeber, Stefanie; Fransson, Petra; Prieto-Ruiz, Inés; Manzoni, Stefano; Weih, Martin

2017-01-01

Individual plant species or genotypes often differ in their demand for nutrients; to compete in a community they must be able to acquire more nutrients (i.e., uptake efficiency) and/or use them more efficiently for biomass production than their competitors. These two mechanisms are often complementary, as there are inherent trade-offs between them. In a mixed-stand, species with contrasting nutrient use patterns interact and may use their resources to increase productivity in different ways. Under contrasting nutrient availabilities, the competitive advantages conferred by either strategy may also shift, so that the interaction between resource use strategy and resource availability ultimately determines the performance of individual genotypes in mixtures. The aim was to investigate growth and nitrogen (N) use efficiency of two willow (Salix) genotypes grown in monoculture and mixture in a fertilizer contrast. We explored the hypotheses that (1) the biomass production of at least one of the involved genotypes should be greater when grown in mixture as compared to the corresponding monoculture when nutrients are the most growth-limiting factor; and (2) the N economy of individual genotypes differs when grown in mixture compared to the corresponding monoculture. The genotypes ‘Tora’ (Salix schwerinii ×S. viminalis) and ‘Loden’ (S. dasyclados), with contrasting phenology and functional traits, were grown from cuttings in a growth container experiment under two nutrient fertilization treatments (high and low) in mono- and mixed-culture for 17 weeks. Under low nutrient level, ‘Tora’ showed a higher biomass production (aboveground biomass, leaf area productivity) and N uptake efficiency in mixture than in monoculture, whereas ‘Loden’ showed the opposite pattern. In addition, ‘Loden’ showed higher leaf N productivity but lower N uptake efficiency than ‘Tora.’ The results demonstrated that the specific functional trait combinations of individual genotypes affect their response to mixture as compared to monoculture. Plants grown in mixture as opposed to monoculture may thus increase biomass and vary in their response of N use efficiency traits. However, young plants were investigated here, and as we cannot predict mixture response in mature stands, our results need to be validated at field scale. PMID:28270828

Two Salix Genotypes Differ in Productivity and Nitrogen Economy When Grown in Monoculture and Mixture.

PubMed

Hoeber, Stefanie; Fransson, Petra; Prieto-Ruiz, Inés; Manzoni, Stefano; Weih, Martin

2017-01-01

Individual plant species or genotypes often differ in their demand for nutrients; to compete in a community they must be able to acquire more nutrients (i.e., uptake efficiency) and/or use them more efficiently for biomass production than their competitors. These two mechanisms are often complementary, as there are inherent trade-offs between them. In a mixed-stand, species with contrasting nutrient use patterns interact and may use their resources to increase productivity in different ways. Under contrasting nutrient availabilities, the competitive advantages conferred by either strategy may also shift, so that the interaction between resource use strategy and resource availability ultimately determines the performance of individual genotypes in mixtures. The aim was to investigate growth and nitrogen (N) use efficiency of two willow ( Salix ) genotypes grown in monoculture and mixture in a fertilizer contrast. We explored the hypotheses that (1) the biomass production of at least one of the involved genotypes should be greater when grown in mixture as compared to the corresponding monoculture when nutrients are the most growth-limiting factor; and (2) the N economy of individual genotypes differs when grown in mixture compared to the corresponding monoculture. The genotypes 'Tora' ( Salix schwerinii × S. viminalis ) and 'Loden' ( S. dasyclados ), with contrasting phenology and functional traits, were grown from cuttings in a growth container experiment under two nutrient fertilization treatments (high and low) in mono- and mixed-culture for 17 weeks. Under low nutrient level, 'Tora' showed a higher biomass production (aboveground biomass, leaf area productivity) and N uptake efficiency in mixture than in monoculture, whereas 'Loden' showed the opposite pattern. In addition, 'Loden' showed higher leaf N productivity but lower N uptake efficiency than 'Tora.' The results demonstrated that the specific functional trait combinations of individual genotypes affect their response to mixture as compared to monoculture. Plants grown in mixture as opposed to monoculture may thus increase biomass and vary in their response of N use efficiency traits. However, young plants were investigated here, and as we cannot predict mixture response in mature stands, our results need to be validated at field scale.

Influence of Organic Amendment and Compaction on Nutrient Dynamics in a Saturated Saline-Sodic Soil from the Riparian Zone.

PubMed

Miller, J J; Bremer, E; Curtis, T

2016-07-01

Cattle grazing in wet riparian pastures may influence nutrient dynamics due to nutrient deposition in feces and urine, soil compaction, and vegetation loss. We conducted a lab incubation study with a saline-sodic riparian soil to study nutrient (N, P, S, Fe, Mn, Cu, and Zn) dynamics in soil pore water using Plant Root Simulator (PRS) probes and release of nutrients into the overlying ponded water during flooding. The treatment factors were organic amendment (manure, roots, and unamended control), compaction (compacted, uncompacted), and burial time (3, 7, and 14 d). Amendment treatment had the greatest impact on nutrient dynamics, followed by burial time, whereas compaction had little impact. The findings generally supported our hypothesis that organic amendments should first increase nitrate loss, then increase Mn mobility, then Fe mobility and associated release of P, and finally increase sulfate loss. Declines in nitrate due to amendment addition were small because nitrate was at low levels in all treatments due to high denitrification potential instead of being released to soil pore water or overlying water. Addition of organic amendment strongly increased Mn and Fe concentrations in overlying water and of adsorbed Fe on PRS probes but only increased Mn on PRS probes on Day 3 due to subsequent displacement from ion exchange membranes. Transport of P to overlying water was increased by organic amendment addition but less so for manure than roots despite higher P on PRS probes. The findings showed that saline-sodic soils in riparian zones are generally a nutrient source for P and are a nutrient sink for N as measured using PRS probes after 3 to 7 d of flooding. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Freshwater bacteria are stoichiometrically flexible with a nutrient composition similar to seston

USGS Publications Warehouse

Cotner, James B.; Hall, Edward K.; Scott, J. Thad; Heldal, Mikal

2010-01-01

Although aquatic bacteria are assumed to be nutrient-rich, they out-compete other foodweb osmotrophs for nitrogen (N) and phosphorus (P) an apparent contradiction to resource ratio theory. This paradox could be resolved if aquatic bacteria were demonstrated to be nutrient-poor relative other portions of the planktonic food web. In a survey of >120 lakes in the upper Midwest of the USA, the nutrient content of bacteria was lower than previously reported and very similar to the Redfield ratio, with a mean biomass composition of 102:12:1 (C:N:P). Individual freshwater bacterial isolates grown under P-limiting and P-replete conditions had even higher C:P and N:P ratios with a mean community biomass composition ratio of 875C:179N:1P suggesting that individual strains can be extremely nutrient-poor, especially with respect to P. Cell-specific measurements of individual cells from one lake confirmed that low P content could be observed at the community level in natural systems with a mean biomass composition of 259C:69N:1P. Variability in bacterial stoichiometry is typically not recognized in the literature as most studies assume constant and nutrient-rich bacterial biomass composition. We present evidence that bacteria can be extremely P-poor in individual systems and in culture, suggesting that bacteria in freshwater ecosystems can either play a role as regenerators or consumers of inorganic nutrients and that this role could switch depending on the relationship between bacterial biomass stoichiometry and resource stoichiometry. This ability to switch roles between nutrient retention and regeneration likely facilitates processing of terrestrial organic matter in lakes and rivers and has important implications for a wide range of bacterially mediated biogeochemical processes.

NPKS uptake, sensing, and signaling and miRNAs in plant nutrient stress.

PubMed

Nath, Manoj; Tuteja, Narendra

2016-05-01

Sessile nature of higher plants consequently makes it highly adaptable for nutrient absorption and acquisition from soil. Plants require 17 essential elements for their growth and development which include 14 minerals (macronutrients: N, P, K, Mg, Ca, S; micronutrients: Cl, Fe, B, Mn, Zn, Cu, Ni, Mo) and 3 non-mineral (C, H, O) elements. The roots of higher plants must acquire these macronutrients and micronutrients from rhizosphere and further allocate to other plant parts for completing their life cycle. Plants evolved an intricate series of signaling and sensing cascades to maintain nutrient homeostasis and to cope with nutrient stress/availability. The specific receptors for nutrients in root, root system architecture, and internal signaling pathways help to develop plasticity in response to the nutrient starvation. Nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) are essential for various metabolic processes, and their deficiency negatively effects the plant growth and yield. Genes coding for transporters and receptors for nutrients as well as some small non-coding RNAs have been implicated in nutrient uptake and signaling. This review summarizes the N, P, K, and S uptake, sensing and signaling events in nutrient stress condition especially in model plant Arabidopsis thaliana and involvement of microRNAs in nutrient deficiency. This article also provides a framework of uptake, sensing, signaling and to highlight the microRNA as an emerging major players in nutrient stress condition. Nutrient-plant-miRNA cross talk may help plant to cope up nutrient stress, and understanding their precise mechanism(s) will be necessary to develop high yielding smart crop with low nutrient input.

Volatile compounds and sensory properties of Montasio cheese made from the milk of Simmental cows grazing on alpine pastures.

PubMed

Bovolenta, S; Romanzin, A; Corazzin, M; Spanghero, M; Aprea, E; Gasperi, F; Piasentier, E

2014-12-01

The aim of this study was to analyze the volatile compounds, physicochemical characteristics, and sensory properties of Montasio, a semicooked pressed cheese, produced from the milk of the dual-purpose Italian Simmental cows grazing on alpine pastures. A total of 72 cows grazing on 2 pastures, which differed in botanical composition (nutrient-rich pasture vs. nutrient-poor pasture), received 2 different levels of supplementation (3.0 vs 1.5 kg/head per day). The experimental cheeses were produced from whole, raw milk and ripened for 60 d. Sixty-one volatile compounds, including alcohols (11), aldehydes (6), ketones (10), lactones (2), esters (6), hydrocarbons (3), carboxylic acids (6), phenolic compounds (4), monoterpenes (7), sesquiterpenes (1), sulfur compounds (4), and amines (1), were detected. The main families in terms of relative weight appeared to be carboxylic acids, esters, and alcohols. A panel of trained assessors described the experimental cheeses as having an intense color; small and evenly distributed eyes; an intense odor and flavor of milk-sour, milk, and cow; and a tender and creamy texture. The pasture type affected the volatile fraction, particularly ketones, phenolic compounds, and terpenes, which are overall higher in nutrient-poor pastures. A slight effect on the sensory analyses, in particular the effect of the cow attribute on odor and flavor, was perceived by the panelists. The cheeses produced on nutrient-rich pasture had higher b* (yellowness) index. These results were consistent with the color evaluation of the sensory panel. In addition, the pasture affected some textural attributes (adhesivity, creaminess, and granules) as perceived by the panelists. Concentrate supplementation, which is required to meet the feeding requirements of grazing cows, had no clear effect on either the volatile compounds or the sensory properties of the cheeses. Thus, at least within levels of integration adopted, it is expected not to alter the organoleptic characteristics of this product. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Gastrointestinal tolerance and plasma status of carotenoids, EPA and DHA with a fiber-enriched tube feed in hospitalized patients initiated on tube nutrition: Randomized controlled trial.

PubMed

Jakobsen, L H; Wirth, R; Smoliner, C; Klebach, M; Hofman, Z; Kondrup, J

2017-04-01

During the first days of tube feeding (TF) gastrointestinal (GI) complications are common and administration of sufficient nutrition is a challenge. Not all standard nutritionally complete formulas contain dietary fiber, fish oil or carotenoids, key dietary nutrients for health and wellbeing. The aim of this study was to investigate the effects of a fiber, fish oil and carotenoid enriched TF formula on diarrhea, constipation and nutrient bioavailability. A multi-center randomized, double-blind, controlled, parallel trial compared the effects of a dietary fiber, fish oil and carotenoid-enriched TF formula (test) with an isocaloric non-enriched formula (control) in 51 patients requiring initiation of TF. Incidence of diarrhea and constipation (based on stool frequency and consistency) was recorded daily. Plasma status of EPA, DHA and carotenoids was measured after 7 days. The incidence of diarrhea was lower in patients receiving the test formula compared with the control group (19% vs. 48%, p = 0.034). EPA and DHA status (% of total plasma phospholipids) was higher after 7 days in test compared with control group (EPA: p = 0.002, DHA: p = 0.082). Plasma carotenoid levels were higher after 7 days in the test group compared with control group (lutein: p = 0.024, α-carotene: p = 0.005, lycopene: p = 0.020, β-carotene: p = 0.054). This study suggests that the nutrient-enriched TF formula tested might have a positive effect on GI tolerance with less diarrhea incidence and significantly improved EPA, DHA and carotenoid plasma levels during the initiation of TF in hospitalized patients who are at risk of diarrhea and low nutrient status. This trial was registered at trialregister.nl; registration number 2924. Copyright © 2016. Published by Elsevier Ltd.

Consumption of grapefruit is associated with higher nutrient intakes and diet quality among adults, and more favorable anthropometrics in women, NHANES 2003-2008.

PubMed

Murphy, Mary M; Barraj, Leila M; Rampersaud, Gail C

2014-01-01

Dietary guidance recommends consumption of a nutrient-dense diet containing a variety of fruits. The purpose of this study was to estimate usual nutrient intakes and adequacy of nutrient intakes among adult grapefruit consumers and non-consumers, and to examine associations between grapefruit consumption and select health parameters. The analysis was conducted with data collected in the National Health and Nutrition Examination Survey (NHANES) 2003-2008. Respondents reporting consumption of any amount of grapefruit or 100% grapefruit juice at least once during the 2 days of dietary recall were classified as grapefruit consumers. Among adults aged 19+ years with 2 days of dietary recall (n=12,789), 2.5% of males and 2.7% of females reported consumption of 100% grapefruit juice or fresh, canned, or frozen grapefruit during the recalls. Grapefruit consumers were less likely to have usual intakes of vitamin C (males: 0% vs. 47%; females: 0% vs. 43%; P<0.001) and magnesium (P<0.05) below the estimated average requirement (EAR) compared to non-consumers, and they were more likely to meet adequate intake levels for dietary fiber (P<0.05). Potassium and β-carotene intakes were significantly higher among grapefruit consumers (P<0.001). Diet quality as assessed by the Healthy Eating Index-2005 (HEI-2005) was higher in grapefruit consumers (males: 66.2 [95% CI: 61.0-71.5] vs. 55.4 [95% CI: 54.4-56.4]; females: 71.4 [95% CI: 65.1-77.6] vs. 61.2 [95% CI: 59.8-62.6]). Among women, grapefruit consumption was associated with lower body weight, waist circumference, body mass index (BMI), triglycerides, C-reactive protein (CRP), and higher high-density lipoprotein (HDL) cholesterol (P<0.05), However, risk of being overweight/obese was not associated with grapefruit consumption. Consumption of grapefruit was associated with higher intakes of vitamin C, magnesium, potassium, dietary fiber, and improved diet quality. Grapefruit may provide a healthful option for adults striving to meet fruit recommendations.

Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

EPA Science Inventory

With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

Primary production and carbon allocation in relation to nutrient supply in a tropical experimental forest

Treesearch

Christian P. Giardina; Michael G. Ryan; Dan Binkley; Dan Binkley; James H. Fownes

2003-01-01

Nutrient supply commonly limits aboveground plant productivity in forests, but the effects of an altered nutrient supply on gross primary production (GPP) and patterns of carbon (C) allocation remain poorly characterized. Increased nutrient supply may lead to a higher aboveground net primary production (ANPP), but a lower total belowground carbon allocation (TBCA),...

Seasonal Progression and Interannual Variability of Nutrient and Chlorophyll-a Distributions in the Northern Gulf of Alaska, 1998-2010

NASA Astrophysics Data System (ADS)

Trahanovsky, K.; Whitledge, T. E.

2016-02-01

We examined nutrient and chlorophyll-a (chl) concentrations from bottle samples collected from 0-50 m depth in the Northern Gulf of Alaska along the Seward Line transect on 56 cruises from 1998-2010. We computed monthly average concentrations of macronutrients (N, P, and Si) and chlorophyll-a by depth at four major stations along the transect to describe the regular seasonal progression of the nutricline and typical water column distributions of chlorophyll-a in this seasonally productive, downwelling coastal zone. The across-shelf transect displayed two different patterns of seasonal progression clearly associated with the Alaska Coastal Current (ACC) and Alaskan Stream (AS) current systems. The annual cycle of nutrient drawdown and replenishment is remarkably consistent from year to year within each system and is well correlated with chl measurements. The spring bloom begins earlier and nutrient depletion is sustained longer in the near-shore ACC then in the AS system centered over the shelf break. Chlorophyll-a concentrations frequently peak at 10-20m depth in both systems during July through October, as nutrients remain depleted in the top 10m. Subsurface nutrients (20 - 50 m depth) begin to recover between July and August and then experience a secondary drawdown between August and October, consistent with higher chl levels observed during the fall bloom. Interannual variability in the progression of the nutricline and the relative contribution of subsurface chl to total chl is presented. Physical data demonstrate increasing stratification in this region due to climate change; the implications for nutrient dynamics and primary production are discussed.

The Effects of Inorganic Nitrogen form and CO2 Concentration on Wheat Yield and Nutrient Accumulation and Distribution

PubMed Central

Carlisle, Eli; Myers, Samuel; Raboy, Victor; Bloom, Arnold

2012-01-01

Inorganic N is available to plants from the soil as ammonium (NH4+) and nitrate (NO3-). We studied how wheat grown hydroponically to senescence in controlled environmental chambers is affected by N form (NH4+ vs. NO3−) and CO2 concentration (“subambient,” “ambient,” and “elevated”) in terms of biomass, yield, and nutrient accumulation and partitioning. Wheat supplied with NH4+ as a sole N source had the strongest response to CO2 concentration. Plants exposed to subambient and ambient CO2 concentrations typically had the greatest biomass and nutrient accumulation under both N forms. In general NH4+-supplied plants had higher concentrations of total N, P, K, S, Ca, Zn, Fe, and Cu, while NO3--supplied plants had higher concentrations of Mg, B, Mn, and NO3- - N. NH4+-supplied plants contained amounts of phytate similar to NO3−-supplied plants but had higher bioavailable Zn, which could have consequences for human health. NH4+-supplied plants allocated more nutrients and biomass to aboveground tissues whereas NO3+-supplied plants allocated more nutrients to the roots. The two inorganic nitrogen forms influenced plant growth and nutrient status so distinctly that they should be treated as separate nutrients. Moreover, plant growth and nutrient status varied in a non-linear manner with atmospheric CO2 concentration. PMID:22969784

The elemental stoichiometry (C, Si, N, P) of the Hebrides Shelf and its role in carbon export

NASA Astrophysics Data System (ADS)

Painter, Stuart C.; Hartman, Susan E.; Kivimäe, Caroline; Salt, Lesley A.; Clargo, Nicola M.; Daniels, Chris J.; Bozec, Yann; Daniels, Lucie; Allen, Stephanie; Hemsley, Victoria S.; Moschonas, Grigorios; Davidson, Keith

2017-12-01

A detailed analysis of the internal stoichiometry of a temperate latitude shelf sea system is presented which reveals strong vertical and horizontal gradients in dissolved nutrient and particulate concentrations and in the elemental stoichiometry of those pools. Such gradients have implications for carbon and nutrient export from coastal waters to the open ocean. The mixed layer inorganic nutrient stoichiometry shifted from balanced N:P in winter, to elevated N:P in spring and to depleted N:P in summer, relative to the Redfield ratio. This pattern suggests increased likelihood of P limitation of fast growing phytoplankton species in spring and of N limitation of slower growing species in summer. However, as only silicate concentrations were below potentially limiting concentrations during summer and autumn the stoichiometric shifts in inorganic nutrient N:P are considered due to phytoplankton nutrient preference patterns rather than nutrient exhaustion. Elevated particulate stoichiometries corroborate non-Redfield optima underlying organic matter synthesis and nutrient uptake. Seasonal variation in the stoichiometry of the inorganic and organic nutrient pools has the potential to influence the efficiency of nutrient export. In summer, when organic nutrient concentrations were at their highest and inorganic nutrient concentrations were at their lowest, the organic nutrient pool was comparatively C poor whilst the inorganic nutrient pool was comparatively C rich. The cross-shelf export of these pools at this time would be associated with different efficiencies regardless of the total magnitude of exchange. In autumn the elemental stoichiometries increased with depth in all pools revealing widespread carbon enrichment of shelf bottom waters with P more intensely recycled than N, N more intensely recycled than C, and Si weakly remineralized relative to C. Offshelf carbon fluxes were most efficient via the inorganic nutrient pool, intermediate for the organic nutrient pool and least efficient for the particulate pool. N loss from the shelf however was most efficient via the dissolved organic nutrient pool. Mass balance calculations suggest that 28% of PO43-, 34% of NO3- and 73% of Si drawdown from the mixed layer fails to reappear in the benthic water column thereby indicating the proportion of the nutrient pools that must be resupplied from the ocean each year to maintain shelf wide productivity. Loss to the neighbouring ocean, the sediments, transference to the dissolved organic nutrient pool and higher trophic levels are considered the most likely fate for these missing nutrients.

SMART lunch box intervention to improve the food and nutrient content of children's packed lunches: UK wide cluster randomised controlled trial.

PubMed

Evans, C E L; Greenwood, D C; Thomas, J D; Cleghorn, C L; Kitchen, M S; Cade, J E

2010-11-01

Government standards are now in place for children's school meals but not for lunches prepared at home. The aim of this trial is to improve the content of children's packed lunches. A cluster randomised controlled trial in 89 primary schools across the UK involving 1291 children, age 8-9 years at baseline. Follow-up was 12 months after baseline. A "SMART" lunch box intervention programme consisted of food boxes, bag and supporting materials. The main outcome measures were weights of foods and proportion of children provided with sandwiches, fruit, vegetables, dairy food, savoury snacks and confectionery in each packed lunch. Levels of nutrients provided including energy, total fat, saturated fat, protein, non-milk extrinsic sugar, sodium, calcium, iron, folate, zinc, vitamin A and vitamin C. Moderately higher weights of fruit, vegetables, dairy and starchy food and lower weights of savoury snacks were provided to children in the intervention group. Children in the intervention group were provided with slightly higher levels of vitamin A and folate. 11% more children were provided with vegetables/salad in their packed lunch, and 13% fewer children were provided with savoury snacks (crisps). Children in the intervention group were more likely to be provided with packed lunches meeting the government school meal standards. The SMART lunch box intervention, targeting parents and children, led to small improvements in the food and nutrient content of children's packed lunches. Further interventions are required to bring packed lunches in line with the new government standards for school meals. Current controlled trials ISRCTN77710993.

Astaxanthin production in marine pelagic copepods grazing on two different phytoplankton diets

NASA Astrophysics Data System (ADS)

Van Nieuwerburgh, Lies; Wänstrand, Ingrid; Liu, Jianguo; Snoeijs, Pauli

2005-02-01

The red carotenoid astaxanthin is a powerful natural antioxidant of great importance in aquatic food webs where it is abundant in eggs and body tissues of fish and crustaceans. Little is known about the impact of the phytoplankton diet on astaxanthin production in copepods, its major pelagic producers. We followed the transfer of carotenoids from phytoplankton to copepods in a mesocosm experiment on the northern Atlantic coast (Norway) and recorded the astaxanthin production in copepods. Wild copepods grazed on nutrient-manipulated phytoplankton blooms, which differed in community composition and nutrient status (nitrogen or silicate limitation). The copepod pigments consisted mainly of free astaxanthin and mono- and diesters of astaxanthin. We found no significant difference in astaxanthin production per copepod individual or per unit C depending on the phytoplankton community. However, in the mesocosms astaxanthin per unit C decreased compared with natural levels, probably through a lower demand for photoprotection by the copepods in the dense phytoplankton blooms. The total astaxanthin production per litre was higher in the silicate-limited mesocosms through increased copepod density. Pigment ratio comparisons suggested that the copepod diet here consisted more of diatoms than in the nitrogen-limited mesocosms. Silicate-saturated diatoms were less grazed, possibly because they could invest more in defence mechanisms against their predators. Our study suggests that the production of astaxanthin in aquatic systems can be affected by changes in nutrient dynamics mediated by phytoplankton community composition and copepod population growth. This bottom-up force may have implications for antioxidant protection at higher trophic levels in the food web.

[Effect of feeding methods in infants on serum lipid profile].

PubMed

Maślanka, R; Siemianowicz, K; Stajszczyk, M; Wojakowski, W

1995-07-01

Mothers very often do not start to breast feed their children, or stop very quickly and introduce various formulas based either on modified or unmodified cow's milk. These infant formulas differ from human milk in their chemical composition. Breast milk is the most suitable source of all nutrients required for the development of a newborn or infant. The serum levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipids were determined. The influence of the type of feeding on the levels of the above-mentioned lipids was analyzed. Higher serum levels of triglycerides in babies fed formulas based on modified cow's milk than in those fed formulas based on unmodified milk were found. Higher serum levels of phospholipids were found in breast-fed babies than in those fed formulas based on unmodified cow's milk.

Systematic evaluation of environmental factors: persistent pollutants and nutrients correlated with serum lipid levels

PubMed Central

Patel, Chirag J; Cullen, Mark R; Ioannidis, John PA; Butte, Atul J

2012-01-01

Background Both genetic and environmental factors contribute to triglyceride, low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) levels. Although genome-wide association studies are currently testing the genetic factors systematically, testing and reporting one or a few factors at a time can lead to fragmented literature for environmental chemical factors. We screened for correlation between environmental factors and lipid levels, utilizing four independent surveys with information on 188 environmental factors from the Centers of Disease Control, National Health and Nutrition Examination Survey, collected between 1999 and 2006. Methods We used linear regression to correlate each environmental chemical factor to triglycerides, LDL-C and HDL-C adjusting for age, age2, sex, ethnicity, socio-economic status and body mass index. Final estimates were adjusted for waist circumference, diabetes status, blood pressure and survey. Multiple comparisons were controlled for by estimating the false discovery rate and significant findings were tentatively validated in an independent survey. Results We identified and validated 29, 9 and 17 environmental factors correlated with triglycerides, LDL-C and HDL-C levels, respectively. Findings include hydrocarbons and nicotine associated with lower HDL-C and vitamin E (γ-tocopherol) associated with unfavourable lipid levels. Higher triglycerides and lower HDL-C were correlated with higher levels of fat-soluble contaminants (e.g. polychlorinated biphenyls and dibenzofurans). Nutrients and vitamin markers (e.g. vitamins B, D and carotenes), were associated with favourable triglyceride and HDL-C levels. Conclusions Our systematic association study has enabled us to postulate about broad environmental correlation to lipid levels. Although subject to confounding and reverse causality bias, these findings merit evaluation in additional cohorts. PMID:22421054

Acclimation of Saccharomyces cerevisiae to low temperature: a chemostat-based transcriptome analysis.

PubMed

Tai, Siew Leng; Daran-Lapujade, Pascale; Walsh, Michael C; Pronk, Jack T; Daran, Jean-Marc

2007-12-01

Effects of suboptimal temperatures on transcriptional regulation in yeast have been extensively studied in batch cultures. To eliminate indirect effects of specific growth rates that are inherent to batch-cultivation studies, genome-wide transcriptional responses to low temperatures were analyzed in steady-state chemostats, grown at a fixed specific growth rate (0.03 h(-1)). Although in vivo metabolic fluxes were essentially the same in cultures grown at 12 and at 30 degrees C, concentrations of the growth-limiting nutrients (glucose or ammonia) were higher at 12 degrees C. This difference was reflected by transcript levels of genes that encode transporters for the growth-limiting nutrients. Several transcriptional responses to low temperature occurred under both nutrient-limitation regimes. Increased transcription of ribosome-biogenesis genes emphasized the importance of adapting protein-synthesis capacity to low temperature. In contrast to observations in cold-shock and batch-culture studies, transcript levels of environmental stress response genes were reduced at 12 degrees C. Transcription of trehalose-biosynthesis genes and intracellular trehalose levels indicated that, in contrast to its role in cold-shock adaptation, trehalose is not involved in steady-state low-temperature adaptation. Comparison of the chemostat-based transcriptome data with literature data revealed large differences between transcriptional reprogramming during long-term low-temperature acclimation and the transcriptional responses to a rapid transition to low temperature.

Breakfast skipping and breakfast type are associated with daily nutrient intakes and metabolic syndrome in Korean adults

PubMed Central

Chung, Sang-Jin; Lee, Yoonna; Lee, Seokhwa

2015-01-01

BACKGROUND/OBJECTIVES Emerging evidence shows that eating breakfast and breakfast types may be associated with health outcomes and dietary intakes in various populations. The aim of this study was to investigate the association between breakfast types in Korean adults with their daily nutrient intakes and health outcomes. SUBJECTS/METHODS A total of 11,801 20- to 64-year-old adults (age 42.9 ± 11.8 yrs [mean ± standard error of the mean]; male 41.1%, female 58.9%) in 2007-2009 Korean National Health and Nutrition Survey data were divided into 5 groups based on breakfast types in a 24-hr dietary recall: rice with 3 or more side dishes (Rice3+, 35.3%), rice with 0-2 side dishes (Rice0-2, 34.73%), noodles (1.56%), bread and cereal (6.56%), and breakfast skipping (21.63%). Daily nutrient intakes and the risk of metabolic syndrome were compared among five groups. RESULTS Compared with Korean Recommended Nutrient Intake levels, the breakfast-skipping group showed the lowest intake level in most nutrients, whereas the Rice3+ group showed the highest. Fat intake was higher in the bread and noodle groups than in the other groups. When compared with the Rice3+ group, the odds ratios for the risk of obesity and metabolic syndrome were increased in the breakfast skipping, Rice0-2, and noodle groups after controlling for confounding variables. CONCLUSIONS The rice-based breakfast group showed better nutritional status and health outcomes when eating with 3 or more side dishes. Nutrition education is needed to emphasize both the potential advantage of the rice-based, traditional Korean diet in terms of nutritional content and the importance of food diversity. PMID:26060541

Altered physiology, cell structure, and gene expression of Theobroma cacao seedlings subjected to Cu toxicity.

PubMed

Souza, Vânia L; de Almeida, Alex-Alan F; Souza, Jadiel de S; Mangabeira, Pedro A O; de Jesus, Raildo M; Pirovani, Carlos P; Ahnert, Dário; Baligar, Virupax C; Loguercio, Leandro L

2014-01-01

Seedlings of Theobroma cacao CCN 51 genotype were grown under greenhouse conditions and exposed to increasing concentrations of Cu (0.005, 1, 2, 4, 8, 16, and 32 mg Cu L(-1)) in nutrient solution. When doses were equal or higher than 8 mg Cu L(-1), after 24 h of treatment application, leaf gas exchange was highly affected and changes in chloroplasts thylakoids of leaf mesophyll cells and plasmolysis of cells from the root cortical region were observed. In addition, cell membranes of roots and leaves were damaged. In leaves, 96 h after treatments started, increases in the percentage of electrolyte leakage through membranes were observed with increases of Cu in the nutrient solution. Moreover, there was an increase in the concentration of thiobarbituric acid-reactive substances in roots due to lipid peroxidation of membranes. Chemical analysis showed that increases in Cu concentrations in vegetative organs of T. cacao increased with the increase of the metal in the nutrient solution, but there was a greater accumulation of Cu in roots than in shoots. The excess of Cu interfered in the levels of Mn, Zn, Fe, Mg, K, and Ca in different organs of T. cacao. Analysis of gene expression via RTq-PCR showed increased levels of MT2b, SODCyt, and PER-1 expression in roots and of MT2b, PSBA, PSBO, SODCyt, and SODChI in leaves. Hence, it was concluded that Cu in nutrient solution at doses equal or above 8 mg L(-1) significantly affected leaf gas exchange, cell ultrastructure, and transport of mineral nutrients in seedlings of this T. cacao genotype.

Nutritional Modulation of Age-Related Macular Degeneration

PubMed Central

Weikel, Karen A; Taylor, Allen

2012-01-01

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30–50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/wk of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available. PMID:22503690

Evaluation of a Validated Food Frequency Questionnaire for Self-Defined Vegans in the United States

PubMed Central

Dyett, Patricia; Rajaram, Sujatha; Haddad, Ella H.; Sabate, Joan

2014-01-01

This study aimed to develop and validate a de novo food frequency questionnaire for self-defined vegans in the United States. Diet histories from pilot samples of vegans and a modified ‘Block Method’ using seven selected nutrients of concern in vegan diet patterns, were employed to generate the questionnaire food list. Food frequency responses of 100 vegans from 19 different U.S. states were obtained via completed mailed questionnaires and compared to multiple telephone-conducted diet recall interviews. Computerized diet analyses were performed. Correlation coefficients, t-tests, rank, cross-tabulations, and probability tests were used to validate and compare intake estimates and dietary reference intake (DRI) assessment trends between the two methods. A 369-item vegan-specific questionnaire was developed with 252 listed food frequency items. Calorie-adjusted correlation coefficients ranged from r = 0.374 to 0.600 (p < 0.001) for all analyzed nutrients except calcium. Estimates, ranks, trends and higher-level participant percentile placements for Vitamin B12 were similar with both methods. Questionnaire intakes were higher than recalls for most other nutrients. Both methods demonstrated similar trends in DRI adequacy assessment (e.g., significantly inadequate vitamin D intake among vegans). This vegan-specific questionnaire can be a useful assessment tool for health screening initiatives in U.S. vegan communities. PMID:25006856

Evaluation of a validated food frequency questionnaire for self-defined vegans in the United States.

PubMed

Dyett, Patricia; Rajaram, Sujatha; Haddad, Ella H; Sabate, Joan

2014-07-08

This study aimed to develop and validate a de novo food frequency questionnaire for self-defined vegans in the United States. Diet histories from pilot samples of vegans and a modified 'Block Method' using seven selected nutrients of concern in vegan diet patterns, were employed to generate the questionnaire food list. Food frequency responses of 100 vegans from 19 different U.S. states were obtained via completed mailed questionnaires and compared to multiple telephone-conducted diet recall interviews. Computerized diet analyses were performed. Correlation coefficients, t-tests, rank, cross-tabulations, and probability tests were used to validate and compare intake estimates and dietary reference intake (DRI) assessment trends between the two methods. A 369-item vegan-specific questionnaire was developed with 252 listed food frequency items. Calorie-adjusted correlation coefficients ranged from r = 0.374 to 0.600 (p < 0.001) for all analyzed nutrients except calcium. Estimates, ranks, trends and higher-level participant percentile placements for Vitamin B12 were similar with both methods. Questionnaire intakes were higher than recalls for most other nutrients. Both methods demonstrated similar trends in DRI adequacy assessment (e.g., significantly inadequate vitamin D intake among vegans). This vegan-specific questionnaire can be a useful assessment tool for health screening initiatives in U.S. vegan communities.

Effects of flood inundation and invasion by Phalaris arundinacea on nitrogen cycling in an Upper Mississippi River floodplain forest

USGS Publications Warehouse

Swanson, Whitney; DeJager, Nathan R.; Strauss, Eric A.; Thomsen, Meredith

2017-01-01

Although floodplains are thought to serve as important buffers against nitrogen (N) transport to aquatic systems, frequent flooding and high levels of nutrient availability also make these systems prone to invasion by exotic plant species. Invasive plants could modify the cycling and availability of nutrients within floodplains, with effects that could feedback to promote the persistence of the invasive species and impact N export to riverine and coastal areas. We examined the effect of flooding on soil properties and N cycling at a floodplain site in Pool 8 of the Upper Mississippi River with 2 plant communities: mature native forest (Acer saccharinum) and patches of an invasive grass (Phalaris arundinacea). Plots were established within each vegetation type along an elevation gradient and sampled throughout the summers of 2013 and 2014. Spatial trends in flooding resulted in higher soil organic matter, porosity, and total nitrogen and carbon in low elevations. Nutrient processes and NH4+ and NO3− availability, however, were best explained by vegetation type and time after flooding. Phalaris plots maintained higher rates of nitrification and higher concentrations of available NH4+ and NO3−. These results suggest that invasion by Phalarismay make nitrogen more readily available and could help to reinforce this species' persistence in floodplain wetlands. They also raise the possibility that Phalaris may decrease floodplain N storage capacity and influence downstream transport of N to coastal zones.

Natural selection for costly nutrient recycling in simulated microbial metacommunities.

PubMed

Boyle, Richard A; Williams, Hywel T P; Lenton, Timothy M

2012-11-07

Recycling of essential nutrients occurs at scales from microbial communities to global biogeochemical cycles, often in association with ecological interactions in which two or more species utilise each others' metabolic by-products. However, recycling loops may be unstable; sequences of reactions leading to net recycling may be parasitised by side-reactions causing nutrient loss, while some reactions in any closed recycling loop are likely to be costly to participants. Here we examine the stability of nutrient recycling loops in an individual-based ecosystem model based on microbial functional types that differ in their metabolism. A supplied nutrient is utilised by a "source" functional type, generating a secondary nutrient that is subsequently used by two other types-a "mutualist" that regenerates the initial nutrient at a growth rate cost, and a "parasite" that produces a refractory waste product but does not incur any additional cost. The three functional types are distributed across a metacommunity in which separate patches are linked by a stochastic diffusive migration process. Regions of high mutualist abundance feature high levels of nutrient recycling and increased local population density leading to greater export of individuals, allowing the source-mutualist recycling loop to spread across the system. Individual-level selection favouring parasites is balanced by patch-level selection for high productivity, indirectly favouring mutualists due to the synergistic productivity benefits of the recycling loop they support. This suggests that multi-level selection may promote nutrient cycling and thereby help to explain the apparent ubiquity and stability of nutrient recycling in nature.

The Irish Sea: Is it eutrophic?

NASA Astrophysics Data System (ADS)

Gowen, R. J.; Tett, P.; Kennington, K.; Mills, D. K.; Shammon, T. M.; Stewart, B. M.; Greenwood, N.; Flanagan, C.; Devlin, M.; Wither, A.

2008-01-01

The question of whether the Irish Sea is eutrophic is addressed by reviewing the evidence for anthropogenic nutrient enrichment, elevated phytoplankton production and biomass and undesirable disturbance in the context of the EU and OSPAR definitions of eutrophication. Winter concentrations of dissolved available inorganic phosphate (DAIP), nitrogen (DAIN as nitrate and nitrite) and silicate (Si) in coastal waters and concentrations of DAIP and Si in offshore waters of the Irish Sea are elevated relative to winter Celtic Sea shelf break concentrations (0.5 μM DAIP, 7.7 μM DAIN and 2.7 μM Si). Significant, negative nutrient salinity relationships and analysis of the Isle of Man nutrient time-series indicate that the elevated Irish Sea levels of DAIP and DAIN are the result of anthropogenic enrichment with highest concentrations (≈2.0 μM DAIP, 30 μM DAIN and 17 μM Si) measured in near shore eastern Irish Sea waters. Summer levels of phytoplankton chlorophyll (Chl) range from <0.1 to 11.4 mg m -3 (mean: 3.4 mg m -3) and from <0.1 to 16.4 mg m -3 (mean: 2.2 mg m -3) in coastal and offshore waters of the western Irish Sea, respectively. Offshore eastern Irish Sea summer chlorophyll levels range from 0.3 to 3.8 mg m -3 (mean: 1.8 mg m -3). Higher levels of spring (up to 43.9 mg m -3) and summer (up to 22.7 mg m -3) biomass in Liverpool Bay are attributed to nutrient enrichment. Estimates of spring and summer production in different regions of the Irish Sea are ≤194 g C m -2. The absence of: (a) oxygen depletion in near shore and open waters of the Irish Sea (except the seasonally isolated western Irish Sea bottom water); (b) trends in the frequency of Phaeocystis spp. blooms and occurrence of toxin producing algae; and (c) changes in the dominant life form of pelagic primary producers, point to a lack of undesirable disturbance and hence argue against anthropogenic eutrophication in the Irish Sea. This conclusion is discussed in the context of future trends in anthropogenic nutrient inputs.

Wastewater Treatment Energy Recovery Potential For Adaptation To Global Change: An Integrated Assessment

NASA Astrophysics Data System (ADS)

Breach, Patrick A.; Simonovic, Slobodan P.

2018-04-01

Approximately 20% of wastewaters globally do not receive treatment, whereas wastewater discharges are projected to increase, thereby leading to excessive water quality degradation of surface waters on a global scale. Increased treatment could help alleviate water quality issues by constructing more treatment plants; however, in many areas there exist economic constraints. Energy recovery methods including the utilization of biogas and incineration of biosolids generated during the treatment process may help to alleviate treatment costs. This study explores the potential for investments in energy recovery from wastewater to increase treatment levels and thus improve surface water quality. This was done by examining the relationships between nutrient over-enrichment, wastewater treatment, and energy recovery at a global scale using system dynamics simulation as part of the ANEMI integrated assessment model. The results show that a significant amount of energy can be recovered from wastewater, which helps to alleviate some of the costs of treatment. It was found that wastewater treatment levels could be increased by 34%, helping to offset the higher nutrient loading from a growing population with access to improved sanitation. The production of renewable natural gas from biogas was found to have the potential to prolong the depletion of natural gas resources used to produce electricity and heat. It is recommended that agricultural nutrient discharges be better managed to help reduce nutrient over-enrichment on global scale. To increase the utility of the simulation, a finer spatial scale should be used to consider regional treatment, economic, and water quality characteristics.

Wastewater Treatment Energy Recovery Potential For Adaptation To Global Change: An Integrated Assessment.

PubMed

Breach, Patrick A; Simonovic, Slobodan P

2018-04-01

Approximately 20% of wastewaters globally do not receive treatment, whereas wastewater discharges are projected to increase, thereby leading to excessive water quality degradation of surface waters on a global scale. Increased treatment could help alleviate water quality issues by constructing more treatment plants; however, in many areas there exist economic constraints. Energy recovery methods including the utilization of biogas and incineration of biosolids generated during the treatment process may help to alleviate treatment costs. This study explores the potential for investments in energy recovery from wastewater to increase treatment levels and thus improve surface water quality. This was done by examining the relationships between nutrient over-enrichment, wastewater treatment, and energy recovery at a global scale using system dynamics simulation as part of the ANEMI integrated assessment model. The results show that a significant amount of energy can be recovered from wastewater, which helps to alleviate some of the costs of treatment. It was found that wastewater treatment levels could be increased by 34%, helping to offset the higher nutrient loading from a growing population with access to improved sanitation. The production of renewable natural gas from biogas was found to have the potential to prolong the depletion of natural gas resources used to produce electricity and heat. It is recommended that agricultural nutrient discharges be better managed to help reduce nutrient over-enrichment on global scale. To increase the utility of the simulation, a finer spatial scale should be used to consider regional treatment, economic, and water quality characteristics.

The relationship of ready-to-eat cereal consumption to nutrient intake, blood lipids, and body mass index of children as they age through adolescence.

PubMed

Albertson, Ann M; Affenito, Sandra G; Bauserman, Robert; Holschuh, Norton M; Eldridge, Alison L; Barton, Bruce A

2009-09-01

To examine sex differences and longitudinal changes in ready-to-eat (RTE) cereal and breakfast consumption in the Dietary Intervention Study in Children, and the relationship between RTE cereal intake with nutrient intake, blood lipids, and body mass index (BMI). Secondary analyses based on data from Dietary Intervention Study in Children, a randomized, controlled, multicenter, clinical trial with five sets of three 24-hour recalls. Children (n=660) from six clinics aged 8 to 10 years at study entry. Participants had serum low-density lipoprotein cholesterol levels between the 80th and 98th percentiles for age, and were followed for a mean of 7.5 years. Children were randomized to a total fat- and saturated fat-modified dietary intervention or usual care. Frequency of RTE cereal and breakfast consumption was examined by sex and age. Mixed models by sex were used to examine the relationship of RTE cereal consumption to average daily intake of nutrients, blood lipids, and BMI. For all children, RTE cereal and breakfast consumption declined with age. Boys consumed RTE cereal more often compared with girls. Except for energy, RTE cereal consumption was positively associated with all measures of nutrients for both sexes. In boys, higher RTE cereal consumption was associated with lower total and low-density lipoprotein cholesterol levels and lower BMI. Food and nutrition professionals should continue to educate youth and their parents on the nutritional benefits of routinely eating RTE cereal.

Bench-scale evaluation of in situ bioremediation strategies for soil at a former manufactured gas plant site.

PubMed

Li, Jun; Pignatello, Joseph J; Smets, Barth F; Grasso, Domenico; Monserrate, Esteban

2005-03-01

We examined the biodegradation and desorption of a set of 15 polycyclic aromatic hydrocarbon (PAH) compounds in coal tar-contaminated soil at a former manufactured gas plant site to evaluate the feasibility of in situ bioremediation. Experiments were conducted in well-mixed aerobic soil suspensions containing various additives over a 93- to 106-d period. In general, both biotransformation and desorption decreased with PAH ring size, becoming negligible for the six-ring PAH compounds. Biodegradation by indigenous microorganisms was strongly accelerated by addition of inorganic nutrients (N, P, K, and trace metals). The rates of biotransformation of PAH compounds by indigenous microorganisms in nutrient-amended flasks outpaced their maximum (i.e., chelate-enhanced) rates of desorption to an infinite sink (Tenax) in sterilized systems run in parallel, suggesting that indigenous organisms facilitated desorption. Biodegradation by indigenous organisms in nutrient-amended flasks appeared to be unaffected by the addition of a site-derived bacterial enrichment culture, resulting in approximately 100-fold higher aromatic dioxygenase levels, and by the addition of 0.01 M chelating agent (citrate or pyrophosphate), although such chelating agents greatly enhanced desorption in microbially inactivated flasks. The strong ability of nutrients to enhance degradation of the bioavailable PAHs indicates that their persistence for many decades at this site likely results from nutrient-limited natural biodegradation, and it also suggests that an effective strategy for their bioremediation could consist simply of adding inorganic nutrients.

Nutrient retention values and cooking yield factors for three South African lamb and mutton cuts.

PubMed

van Heerden, Salomina M; Strydom, Phillip E

2017-11-01

Nutrient content of raw and cooked foods is important for formulation of healthy diets. The retention of nutrients during cooking can be influenced by various factors, including animal age, carcass characteristics and cooking method, and these factors are often unique to specific countries. Here the effects of animal age (lamb and mutton) and carcass cut (shoulder, loin and leg) combined with cooking method (moist heat and dry heat) on yield and nutrient retention of selected nutrients of South African sheep carcasses were studied. Cooking yields and moisture retention were lower for lamb loin but higher for lamb leg. Energy and fat retention were higher for all cuts of mutton compared with lamb, while higher retention values for cholesterol were recorded for lamb. Mutton retained more iron (P = 0.10) and zinc and also more vitamin B 2 , B 6 and B 12 than lamb. Shoulder cooked according to moist heat cooking method retained more magnesium, potassium and sodium. Incorporating these retention and yield values into the South African Medical Research Council's Food Composition Tables provides a reliable reference to all concerned with nutrient content of food. It will also guide practitioners and primary industry to adjust animal production aimed at optimum nutrient content to specific diets. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Salmon-derived nitrogen in terrestrial invertebrates from coniferous forests of the Pacific Northwest

PubMed Central

2002-01-01

Background Bi-directional flow of nutrients between marine and terrestrial ecosystems can provide essential resources that structure communities in transitional habitats. On the Pacific coast of North America, anadromous salmon (Oncorhynchus spp.) constitute a dominant nutrient subsidy to aquatic habitats and riparian vegetation, although the contribution to terrestrial habitats is not well established. We use a dual isotope approach of δ15N and δ13C to test for the contribution of salmon nutrients to multiple trophic levels of litter-based terrestrial invertebrates below and above waterfalls that act as a barrier to salmon migration on two watersheds in coastal British Columbia. Results Invertebrates varied predictably in δ15N with enrichment of 3–8‰ below the falls compared with above the falls in all trophic groups on both watersheds. We observed increasing δ15N levels in our invertebrate groups with increasing consumption of dietary protein. Invertebrates varied in δ13C but did not always vary predictably with trophic level or habitat. From 19.4 to 71.5% of invertebrate total nitrogen was originally derived from salmon depending on taxa, watershed, and degree of fractionation from the source. Conclusions Enrichment of δ15N in the invertebrate community below the falls in conjunction with the absence of δ13C enrichment suggests that enrichment in δ15N occurs primarily through salmon-derived nitrogen subsidies to litter, soil and vegetation N pools rather than from direct consumption of salmon tissue or salmon tissue consumers. Salmon nutrient subsidies to terrestrial habitats may result in shifts in invertebrate community structure, with subsequent implications for higher vertebrate consumers, particularly the passerines. PMID:11914157

Food Web Architecture and Basal Resources Interact to Determine Biomass and Stoichiometric Cascades along a Benthic Food Web

PubMed Central

Guariento, Rafael D.; Carneiro, Luciana S.; Caliman, Adriano; Leal, João J. F.; Bozelli, Reinaldo L.; Esteves, Francisco A.

2011-01-01

Understanding the effects of predators and resources on primary producers has been a major focus of interest in ecology. Within this context, the trophic cascade concept especially concerning the pelagic zone of lakes has been the focus of the majority of these studies. However, littoral food webs could be especially interesting because base trophic levels may be strongly regulated by consumers and prone to be light limited. In this study, the availability of nutrients and light and the presence of an omnivorous fish (Hyphessobrycon bifasciatus) were manipulated in enclosures placed in a humic coastal lagoon (Cabiúnas Lagoon, Macaé – RJ) to evaluate the individual and interactive effects of resource availability (nutrients and light) and food web configuration on the biomass and stoichiometry of periphyton and benthic grazers. Our findings suggest that light and nutrients interact to determine periphyton biomass and stoichiometry, which propagates to the consumer level. We observed a positive effect of the availability of nutrients on periphytic biomass and grazers' biomass, as well as a reduction of periphytic C∶N∶P ratios and an increase of grazers' N and P content. Low light availability constrained the propagation of nutrient effects on periphyton biomass and induced higher periphytic C∶N∶P ratios. The effects of fish presence strongly interacted with resource availability. In general, a positive effect of fish presence was observed for the total biomass of periphyton and grazer's biomass, especially with high resource availability, but the opposite was found for periphytic autotrophic biomass. Fish also had a significant effect on periphyton stoichiometry, but no effect was observed on grazers' stoichiometric ratios. In summary, we observed that the indirect effect of fish predation on periphyton biomass might be dependent on multiple resources and periphyton nutrient stoichiometric variation can affect consumers' stoichiometry. PMID:21789234

Development of a Dietary Index to Assess Overall Diet Quality for Chinese School-Aged Children: The Chinese Children Dietary Index.

PubMed

Cheng, Guo; Duan, Ruonan; Kranz, Sibylle; Libuda, Lars; Zhang, Lishi

2016-04-01

A composite measure of diet quality is preferable to an index of nutrients, food groups, or health-promoting behaviors in dietary assessment. However, to date, such a tool for Chinese children is lacking. Based on the current Chinese Dietary Guidelines and Dietary Reference Intakes, a dietary index for Chinese school-aged children, the Chinese Children Dietary Index was developed to assess overall diet quality among children in South China. Dietary data were recorded using 24-hour recalls among 1,719 children aged 7 to 15 years between March and June 2013. Inactivity data and sociodemographic information were also collected. The Chinese Children Dietary Index included 16 components, which incorporated nutrients, foods/food groups, and health-promoting behaviors. The range of possible Chinese Children Dietary Index scores was 0 to 160, with a higher score indicating better diet quality. Pearson/Spearman correlation was used to assess relative validity using correlations between total Chinese Children Dietary Index score and age, body mass index (BMI; calculated as kg/m(2)), inactivity, whole-grain intake, frequency of fried-foods intake, nutrient adequacy ratios for energy intake and 12 nutrients not included in the Chinese Children Dietary Index, and the mean adequacy ratio. Finally, a stepwise multiple regression analysis was performed to indicate the factors correlated with Chinese Children Dietary Index. Mean Chinese Children Dietary Index score of this sample was 88.1 points (range=34.2 to 137.8), the Chinese Children Dietary Index score of girls was higher than that of boys and decreased with higher age. Children with higher Chinese Children Dietary Index had lower body mass index and spent less time being inactive. Positive associations were observed between Chinese Children Dietary Index and the majority of nutrient adequacy ratios and the mean adequacy ratio. Age, paternal educational level, and family size were correlated with Chinese Children Dietary Index. The Chinese Children Dietary Index successfully differentiated diets and, therefore, it can be used to rank-order overall diet quality among Chinese children. As the results showed, diet quality among Chinese children needs to be improved, especially in adolescents. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Adequate nutrient intake can reduce cardiovascular disease risk in African Americans.

PubMed

Reusser, Molly E; DiRienzo, Douglas B; Miller, Gregory D; McCarron, David A

2003-03-01

Cardiovascular disease kills nearly as many Americans each year as the next seven leading causes of death combined. The prevalence of cardiovascular disease and most of its associated risk factors is markedly higher and increasing more rapidly among African Americans than in any other racial or ethnic group. Improving these statistics may be simply a matter of improving diet quality. In recent years, a substantial and growing body of evidence has revealed that dietary patterns complete in all food groups, including nutrient-rich dairy products, are essential for preventing and reducing cardiovascular disease and the conditions that contribute to it. Several cardiovascular risk factors, including hypertension, insulin resistance syndrome, and obesity, have been shown to be positively influenced by dietary patterns that include adequate intake of dairy products. The benefits of nutrient-rich dietary patterns have been specifically tested in randomized, controlled trials emphasizing African American populations. These studies demonstrated proportionally greater benefits for African Americans without evidence of adverse effects such as symptoms of lactose intolerance. As currently promoted for the prevention of certain cancers and osteoporosis, regular consumption of diets that meet recommended nutrient intake levels might also be the most effective approach for reducing cardiovascular disease risk in African Americans.

Uptake of perfluorinated compounds by plants grown in nutrient solution.

PubMed

García-Valcárcel, A I; Molero, E; Escorial, M C; Chueca, M C; Tadeo, J L

2014-02-15

The uptake rates of three perfluorinated carboxylates and three perfluorinated sufonates by a grass (B diandrus) grown in nutrient solution at two different perfluorinated compounds (PFCs) concentrations were assessed. Grass can be ingested by grazing animals causing the PFCs to enter the food chain, which is a pathway of human exposure to these compounds. A rapid and miniaturized method was developed to determine PFCs in plants, based on a matrix solid-phase dispersion (MSPD) extraction procedure followed by quantitation by HPLC-MS/MS with an MQL in the range from 1 to 9 ng/g. An increase of PFCs levels in plant was observed along the exposure time. Differences in uptake for studied perfluorinated carboxylates were found, showing a decrease with carbon chain length (from 3027 to 1,167 ng/g at the end of assay), whereas no significant differences in absorption were obtained between perfluorinated sulfonates (about 1,700 ng/g). Initially, higher PFC transfer factors (ratio between concentration in plant and concentration in initial nutrient solution) were obtained for plants growing in the nutrient solution at the highest PFC concentration, but these factors became similar with time to plants exposed to the lowest concentration. © 2013 Elsevier B.V. All rights reserved.

Examining Dehydration and Hypoxic Stress in Wheat Plants Using a Porous Tube Plant Nutrient Delivery System Developed for Microgravity

NASA Technical Reports Server (NTRS)

Dreschel, T. W.; Hall, C. R.; Foster, T. E.; Salganic, M.; Warren, L.; Corbett, M.

2005-01-01

The Porous Tube Plant Nutrient Delivery System (PTPNDS) was designed for NASA to grow plants in microgravity of space. The system utilizes a controlled fluid loop to supply nutrients and water to plant roots growing on a ceramic surface moistened by capiflary action. A PTPNDS test bed was developed and utilizing remote sensing systems, spectral analyses procedures, gas-exchange, and fluorescence measurements, we examined differences in plant water status for wheat plants (Triticum aestivum, cv. Perigee) grown in a modified growth chamber during the summers of 2003 and 2004. Some differences in plant performance were detectable in the gas-exchange and fluorescence measurements. For instance, in both years the plants grown with the most available water had the lowest rates of photosynthesis and exhibited higher proportions of non-photochemical quenching particularly under low light levels. In addition, small differences in mean leaf water content between treatments were detected using spectral reflectance analyses.

A hydrolase of trehalose dimycolate induces nutrient influx and stress sensitivity to balance intracellular growth of Mycobacterium tuberculosis

PubMed Central

Yang, Yong; Kulka, Kathleen; Montelaro, Ronald C.; Reinhart, Todd A.; Sissons, James; Aderem, Alan; Ojha, Anil K.

2014-01-01

Summary Chronic tuberculosis in an immunocompetent host is a consequence of the delicately balanced growth of Mycobacterium tuberculosis (Mtb) in the face of host defense mechanisms. We identify an Mtb enzyme (TdmhMtb) that hydrolyzes the mycobacterial glycolipid trehalose dimycolate and plays a critical role in balancing the intracellular growth of the pathogen. TdmhMtb is induced under nutrient limiting conditions and remodels the Mtb envelope to increase nutrient influx, but concomitantly sensitizes Mtb to stresses encountered in the host. Consistent with this, a ΔtdmhMtb mutant is more resilient to stress and grows to higher levels than wild-type in immunocompetent mice. By contrast, mutant growth is retarded in MyD88−/− mice indicating that TdmhMtb provides a growth advantage to intracellular Mtb in an immunocompromised host. Thus, the effects and counter-effects of TdmhMtb play an important role in balancing intracellular growth of Mtb in a manner that is directly responsive to host innate immunity. PMID:24528862

Variation in nitrogen use efficiencies on Dutch dairy farms.

PubMed

Daatselaar, Co Hg; Reijs, Joan R; Oenema, Jouke; Doornewaard, Gerben J; Aarts, H Frans M

2015-12-01

On dairy farms, the input of nutrients including nitrogen is higher than the output in products such as milk and meat. This causes losses of nitrogen to the environment. One of the indicators for the losses of nitrogen is the nitrogen use efficiency. In the Dutch Minerals Policy Monitoring Program (LMM), many data on nutrients of a few hundred farms are collected which can be processed by the instrument Annual Nutrient Cycle Assessment (ANCA, in Dutch: Kringloopwijzer) in order to provide nitrogen use efficiencies. After dividing the dairy farms (available in the LMM program) according to soil type and in different classes for milk production ha(-1) , it is shown that considerable differences in nitrogen use efficiency exist between farms on the same soil type and with the same level of milk production ha(-1) . This offers opportunities for improvement of the nitrogen use efficiency on many dairy farms. Benchmarking will be a useful first step in this process. © 2015 Society of Chemical Industry.

[Rhizosphere effect of nutrients in different maize soils with different fertility levels].

PubMed

Wu, L; Zhang, S

2000-08-01

Maize plants and soil samples were collected from Jilin Province to study the nutrient dynamics in soil-maize plant rhizosphere and their relationship with plant uptake. The results showed that NH4(+)-N and NO3(-)-N were accumulated in rhizospheric soil, and mainly controlled by the application of chemical fertilizers. Soil available P was depleted in high fertility fields, especially in high seedling density, while accumulated in low fertility fields. Soil available K was accumulated in rhizospheric soil, and its accumulation rate was higher in high fertility than in low fertility fields. The nutrient absorption amount was N approximately K > P for maize plant shoots and roots, but was N > K > P for seeds. The contribution rate of chemical fertilizers to maize yield was only 1/5-1/3 in Jilin Province, and the rest was contributed by the application of organic manure, such as chicken feces or cow feces, and by the mineralization of soil organic matter.

Determination of Proximate, Minerals, Vitamin and Anti-Nutrients Composition of Solanum verbascifolium Linn.

NASA Astrophysics Data System (ADS)

Sam, S. M.; Udosen, I. R.; Mensah, S. I.

2012-07-01

The proximate, minerals, vitamins and anti-nutrients composition of Solanum verbascifolium Linn were determined. The proximate composition showed that moisture content was (85.5%), protein was (32.55%), lipid was (2.90%), ash was (7.20%), fibre was (4.80%), carbohydrate was (52.55%) and caloric value was (366.50%) respectively. This was found to be rich in protein and considerably high amount of carbohydrate. The anti-nutrient composition analysis revealed the presence of hydrocyanide (1.39mg/100g), Oxalate (114.40mg/100g), all of which are below toxic level except for oxalic acid. For mineral and vitamin compositions, potassium was significantly (P>0.05) higher than iron, sodium, calcium and phosphorus while vitamin A retinol was (371.72mg/100g) and vitamin C ascorbic acid (39.99mg/100g). Based on these findings the plant is recommended for consumption and for further investigation as a potential raw material for pharmaceutical industry.

Nitrogen regulation of transpiration controls mass-flow acquisition of nutrients.

PubMed

Matimati, Ignatious; Verboom, G Anthony; Cramer, Michael D

2014-01-01

Transpiration may enhance mass-flow of nutrients to roots, especially in low-nutrient soils or where the root system is not extensively developed. Previous work suggested that nitrogen (N) may regulate mass-flow of nutrients. Experiments were conducted to determine whether N regulates water fluxes, and whether this regulation has a functional role in controlling the mass-flow of nutrients to roots. Phaseolus vulgaris were grown in troughs designed to create an N availability gradient by restricting roots from intercepting a slow-release N source, which was placed at one of six distances behind a 25 μm mesh from which nutrients could move by diffusion or mass-flow (termed 'mass-flow' treatment). Control plants had the N source supplied directly to their root zone so that N was available through interception, mass-flow, and diffusion (termed 'interception' treatment). 'Mass-flow' plants closest to the N source exhibited 2.9-fold higher transpiration (E), 2.6-fold higher stomatal conductance (gs), 1.2-fold higher intercellular [CO2] (Ci), and 3.4-fold lower water use efficiency than 'interception' plants, despite comparable values of photosynthetic rate (A). E, gs, and Ci first increased and then decreased with increasing distance from the N source to values even lower than those of 'interception' plants. 'Mass-flow' plants accumulated phosphorus and potassium, and had maximum concentrations at 10mm from the N source. Overall, N availability regulated transpiration-driven mass-flow of nutrients from substrate zones that were inaccessible to roots. Thus when water is available, mass-flow may partially substitute for root density in providing access to nutrients without incurring the costs of root extension, although the efficacy of mass-flow also depends on soil nutrient retention and hydraulic properties.

Nitrogen regulation of transpiration controls mass-flow acquisition of nutrients

PubMed Central

Matimati, Ignatious

2014-01-01

Transpiration may enhance mass-flow of nutrients to roots, especially in low-nutrient soils or where the root system is not extensively developed. Previous work suggested that nitrogen (N) may regulate mass-flow of nutrients. Experiments were conducted to determine whether N regulates water fluxes, and whether this regulation has a functional role in controlling the mass-flow of nutrients to roots. Phaseolus vulgaris were grown in troughs designed to create an N availability gradient by restricting roots from intercepting a slow-release N source, which was placed at one of six distances behind a 25 μm mesh from which nutrients could move by diffusion or mass-flow (termed ‘mass-flow’ treatment). Control plants had the N source supplied directly to their root zone so that N was available through interception, mass-flow, and diffusion (termed ‘interception’ treatment). ‘Mass-flow’ plants closest to the N source exhibited 2.9-fold higher transpiration (E), 2.6-fold higher stomatal conductance (g s), 1.2-fold higher intercellular [CO2] (C i), and 3.4-fold lower water use efficiency than ‘interception’ plants, despite comparable values of photosynthetic rate (A). E, g s, and C i first increased and then decreased with increasing distance from the N source to values even lower than those of ‘interception’ plants. ‘Mass-flow’ plants accumulated phosphorus and potassium, and had maximum concentrations at 10mm from the N source. Overall, N availability regulated transpiration-driven mass-flow of nutrients from substrate zones that were inaccessible to roots. Thus when water is available, mass-flow may partially substitute for root density in providing access to nutrients without incurring the costs of root extension, although the efficacy of mass-flow also depends on soil nutrient retention and hydraulic properties. PMID:24231035

Micronization increases vitamin E carrying and releasing abilities of insoluble fiber.

PubMed

Hsu, Pang-Kuei; Chien, Po-Jung; Chau, Chi-Fai

2008-03-26

This study was to investigate the effects of micronization on vitamin-carrying capacity and slow-release ability of carambola (starfruit) insoluble fiber (IF) and cellulose using in vitro and in vivomodels. Upon micronization, carambola IF (8.1 microm) underwent structural changes to expose more functional groups in the fiber matrix and to exhibit higher oil-holding capacity ( approximately 20.4-fold). Micronized fibers in forms of fiber-vitamin composites, particularly the micronized carambola IF-vitamin composite, were capable of carrying vitamin E (alpha-tocopherol) up to 9.6-fold over their unmicronized forms and releasing nutrient gradually. Animal studies demonstrated that the adminstration of micronized carambola IF-vitamin composite could maintain the plasma vitamin E of rats at relatively higher levels (2.1-3.6-fold of the initial values) for at least 5 h. The results suggested that micronized fibers, particularly the micronized carambola IF, could be exploited as potential nutrient carriers in food applications and also be used to produce slow-release formulations.

Factors Influencing Nutritional Adequacy among Rural Households in Nigeria: How Does Dietary Diversity Stand among Influencers?

PubMed

Akerele, D; Sanusi, R A; Fadare, O A; Ashaolu, O F

2017-01-01

This study examined the influence of food consumption diversity on adequate intakes of food calories, proteins and micronutrients among households in rural Nigeria within the framework of panel data econometrics using a nationally representative data. We found that substantial proportion of households suffered deficiency of calories, proteins and certain micronutrients; with higher percentage of sufferer households occurring in the post-planting season. The different measures of dietary diversity (constructed and used for analysis) consistently indicate significant and positive influence of dietary diversity on the likelihood of adequate consumption of food nutrients. While higher level of income, education and non-farm enterprise engagement may strongly stimulate adequate nutrient intakes, increases in the number of adolescents would substantially diminish it. Although our findings call for renewed attention on diet diverseness, we stress the complementary/synergistic roles of education and rural income improvement, especially through non-farm enterprise diversification in tackling multiple nutritional deficiencies in rural Nigeria.

Dietary pattern classifications with nutrient intake and health-risk factors in Korean men.

PubMed

Lee, Ji Eun; Kim, Jung-Hyun; Son, Say Jin; Ahn, Younjhin; Lee, Juyoung; Park, Chan; Lee, Lilha; Erickson, Kent L; Jung, In-Kyung

2011-01-01

This study was performed to identify dietary patterns in Korean men and to determine the associations among dietary patterns, nutrient intake, and health-risk factors. Using baseline data from the Korean Health and Genome Study, dietary patterns were identified using factor analysis of data from a validated food-frequency questionnaire, and associations between these dietary patterns and health-risk factors were analyzed. Three dietary patterns were identified: 1) the "animal-food" pattern (greater intake of meats, fish, and dairy products), 2) the "rice-vegetable" pattern (greater intake of rice, tofu, kimchi, soybean paste, vegetables, and seaweed), and 3) the "noodle-bread" pattern (greater intake of instant noodles, Chinese noodles, and bread). The animal-food pattern (preferred by younger people with higher income and education levels) had a positive correlation with obesity and hypercholesterolemia, whereas the rice-vegetable pattern (preferred by older people with lower income and educational levels) was positively associated with hypertension. The noodle-bread pattern (also preferred by younger people with higher income and education levels) had a positive association with abdominal obesity and hypercholesterolemia. This study identifies three unique dietary patterns in Korean men, which are independently associated with certain health-risk factors. The rice-vegetable dietary pattern, modified for a low sodium intake, might be a healthy dietary pattern for Korean men. Copyright © 2011 Elsevier Inc. All rights reserved.

High copper content in vineyard soils promotes modifications in photosynthetic parameters and morphological changes in the root system of 'Red Niagara' plantlets.

PubMed

Ambrosini, Vítor Gabriel; Rosa, Daniel José; Bastos de Melo, George Wellington; Zalamena, Jovani; Cella, Cesar; Simão, Daniela Guimarães; Souza da Silva, Leandro; Pessoa Dos Santos, Henrique; Toselli, Moreno; Tiecher, Tadeu Luis; Brunetto, Gustavo

2018-05-08

High copper (Cu) soil contents, due to the continuous vineyard application of Cu fungicides throughout the years, may impair the growth of the shoot and modify the structure of the root system. The current study aimed to investigate the threshold levels of available Cu in the soil causing toxicity effects in young grapevine plants of 'Red Niagara' cultivated in clay soils. Grapevine plantlets were cultivated in pots containing vineyard devoted soils with increasing contents of available Cu (25, 80, 100 and 165 mg kg -1 ), for 53 days. Photosynthesis and transpiration rates, and the quantum yield of photosystem II (Fv/Fm) were evaluated during the cultivation period. At the end of the experiment, the plant nutrient and leaf chlorophyll were determined, along with the anatomical analysis of the root system structure and plant dry matter determination. Higher levels of available Cu in the soil increased the apoplastic, symplastic and total fraction of the metal in the roots, reducing the other nutrients, especially in the shoots. Photosynthesis, transpiration rates and Fv/Fm were also reduced. Higher levels of Cu led to anatomical changes in the roots, that increased diameter, number of layers in the cortex, vascular cylinder and total root areas. It also resulted in reduced dry matter production by grapevines. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Analysis of bacterial diversity in two oil blocks from two low-permeability reservoirs with high salinities

PubMed Central

Xiao, Meng; Sun, Shan-Shan; Zhang, Zhong-Zhi; Wang, Jun-Ming; Qiu, Long-Wei; Sun, Hua-Yang; Song, Zhao-Zheng; Zhang, Bei-Yu; Gao, De-Li; Zhang, Guang-Qing; Wu, Wei-Min

2016-01-01

The community diversities of two oil reservoirs with low permeability of 1.81 × 10−3 and 2.29 × 10−3 μm2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly. PMID:26786765

Research to Inform Nutrient Thresholds and Prioritization of Watersheds for Nutrient Management

EPA Science Inventory

The information in this presentation focuses on SSWR's 4.02 project, which will advance the science needed to inform decisions to prioritize watersheds and nutrient sources for nutrient management and define appropriate nutrient levels for the nation’s waters, two importan...

Effect of processing on proximate composition, anti-nutrient status and amino acid content in three accessions of African locust bean (Parkia biglobosa (jacq.) benth.

PubMed

Urua, Ikootobong Sunday; Uyoh, Edak Aniedi; Ntui, Valentine Otang; Okpako, Elza Cletus

2013-02-01

Proximate composition, amino acid levels and anti-nutrient factors (polyphenols, phytic acid and oxalate) in the seeds of Parkia biglobosa were determined at three stages: raw, boiled and fermented. The highest anti-nutrient factor present in the raw state was oxalate, while phytic acid was the least. The amino acid of the raw seeds matched favourably to the World Health Organization reference standard. After processing, boiling increased fat, crude fibre and protein, while it reduced moisture, ash and the anti-nutrient content in 64% of the cases examined. Fermentation reduced ash, crude fibre and carbohydrate in all the accessions. It increased the moisture, fat and protein, while reducing the anti-nutrient factors in 78% of the cases. The high levels of protein, fat and amino acids coupled with the low levels of the anti-nutrients in the boiled and fermented seeds make Parkia a good source of nutrients for humans and livestock.

Escherichia coli growth under modeled reduced gravity

NASA Technical Reports Server (NTRS)

Baker, Paul W.; Meyer, Michelle L.; Leff, Laura G.

2004-01-01

Bacteria exhibit varying responses to modeled reduced gravity that can be simulated by clino-rotation. When Escherichia coli was subjected to different rotation speeds during clino-rotation, significant differences between modeled reduced gravity and normal gravity controls were observed only at higher speeds (30-50 rpm). There was no apparent affect of removing samples on the results obtained. When E. coli was grown in minimal medium (at 40 rpm), cell size was not affected by modeled reduced gravity and there were few differences in cell numbers. However, in higher nutrient conditions (i.e., dilute nutrient broth), total cell numbers were higher and cells were smaller under reduced gravity compared to normal gravity controls. Overall, the responses to modeled reduced gravity varied with nutrient conditions; larger surface to volume ratios may help compensate for the zone of nutrient depletion around the cells under modeled reduced gravity.

Nonlinear responses of coastal salt marshes to nutrient additions and sea level rise

EPA Science Inventory

Increasing nutrients and accelerated sea level rise (SLR) can cause marsh loss in some coastal systems. Responses to nutrients and SLR are complex and vary with soil matrix, marsh elevation, sediment inputs, and hydroperiod. We describe field and greenhouse studies examining sing...

Diet composition and blood values of captive cheetahs (Acinonyx jubatus) fed either supplemented meat or commercial food preparations.

PubMed

Bechert, Ursula; Mortenson, Jack; Dierenfeld, Ellen S; Cheeke, Peter; Keller, Mark; Holick, Michael; Chen, Tai C; Rogers, Quinton

2002-03-01

Nutrition most certainly affects health and may play a role in the etiology of growth and reproductive problems in captive cheetah (Acinonyxjubatus) populations. The objective of our research was to examine nutritional differences between two dietary regimens and quantify their physiologic effects on cheetahs held in captivity. Twelve cheetahs were randomly assigned to either a commercial diet (COM) or a supplemented meat diet (SMD) group. These cats were physically examined and had blood samples taken three times over the course of a year. Representative samples of COM and four separate components of the SMD treatment were analyzed over the same time frame for proximate nutrient composition, digestibility, and concentrations of taurine, fat-soluble vitamins, and selected minerals. Concentrations of fat, vitamins A and E, Se, Fe, Cu, Na, and Mn were significantly higher in COM compared with those in SMD samples, with the exception of fat content in turkey. Mg content was lower in COM than in SMD; other nutrients did not differ. Mean concentrations of vitamins A and E in COM were markedly higher than in SMD samples (408,140 vs. 29,696 IU/kg dry matter [DM] and 431 vs. 48 IU/kg DM, respectively) and varied dramatically between sampling periods. Percent crude protein and protein-to-fat ratios were high for SMD compared with either whole prey-based or commercial food preparations. Blood urea nitrogen and serum creatinine levels were above normal reference means for domestic cats. Plasma concentrations of vitamins A, D, and E were significantly higher in COM-fed than in SMD-fed cheetahs. Both plasma retinol and tocopherol levels were almost three times higher in COM-fed cats (1.26 +/- 0.06 vs. 0.53 +/- 0.03 microg/ml and 17.5 +/- 0.7 vs. 6.4 +/- 0.02 microg/ml, respectively) and exceeded the normal ranges expected for domestic felids. Significant differences between male and female cheetahs were found for plasma concentrations of vitamin E, Se, and Fe after allowing for effects of diet and time of collection. Excess fat-soluble dietary vitamins can result in direct toxicities as well as nutrient antagonisms and may be linked to reproductive and health issues in captive cheetahs. The high protein levels found in SMD may be linked to chronic renal disease, which was detected in some of these cheetahs.

Effect of increased temperature, CO2, and iron on nitrate uptake and primary productivity in the coastal Ross Sea

NASA Astrophysics Data System (ADS)

Bronk, D. A.; Spackeen, J.; Sipler, R. E.; Bertrand, E. M.; Roberts, Q. N.; Xu, K.; Baer, S. E.; McQuaid, J.; Zhu, Z.; Walworth, N. G.; Hutchins, D. A.; Allen, A. E.

2016-02-01

Western Antarctic Seas are rapidly changing as a result of elevated concentrations of CO2 and rising sea surface temperatures. It is critical to determine how the structure and function of microbial communities will be impacted by these changes in the future because the Southern Ocean has seasonally high rates of primary production, is an important sink for anthropogenic CO2, and supports a diverse assemblage of higher trophic level organisms. During the Austral summer of 2013 and 2015, a collaborative research group conducted a series of experiments to understand how the individual and combined effects of temperature, CO2, and iron impact Ross Sea microorganisms. Our project used a variety of approaches, including batch experiments, semi-continuous experiments, and continuous-culturing over extended time intervals, to determine how future changes may shift Ross Sea microbial communities and how nutrient cycling and carbon biogeochemistry may subsequently be altered. Chemical and biological parameters were measured throughout the experiments to assess changes in community composition and nutrient cycling, including uptake rate measurements of nitrate and bicarbonate by different size fractions of microorganisms. Relative to the control, nitrate uptake rates significantly increased when temperature and iron were elevated indicating that temperature and iron are important physical drivers that influence nutrient cycling. Elevations in temperature and iron independently and synergistically produced higher rates than elevated CO2. Our nutrient uptake results also suggest that the physiology of large microorganisms will be more impacted by climate change variables than small microorganisms.

Calcium, nutrient and food intake of Greek Orthodox Christian monks during a fasting and non-fasting week.

PubMed

Papadaki, Angeliki; Vardavas, Constantine; Hatzis, Christos; Kafatos, Anthony

2008-10-01

To assess the Ca, nutrient and food intake of Greek Orthodox Christian monks during a vegetarian-type fasting week, compared with their normal diet. Dietary data collection (using 7 d weighed food records), anthropometric and blood pressure measurements, as well as serum glucose and lipid analyses, were performed during Palm Sunday week (fasting) and the week following Pentecost Sunday (non-fasting). Mean daily nutrient and food (g/d) intakes were calculated from the food records. The study took place in two monasteries in the Municipality of Heraklion, Crete. The study involved ten healthy monks aged 25-65 years, with BMI > 30 kg/m2, who had been performing fasts for the last 24.4 (SD 10.4) years and lived in monasteries in Crete during April-June 2005. Nutrient and food intake profiles were more favourable during the fasting week, when participants had lower intakes of total and saturated fat and trans-fatty acids, and higher intakes of dietary fibre, Fe, folate, legumes and fish/seafood. Ca intake was lower when participants fasted, whereas consumption of dairy products, meat and eggs increased significantly in the non-fasting week. Systolic blood pressure was significantly higher, whereas blood lipid levels were more favourable during the fasting week. The periodic vegetarianism recommended by the Greek Orthodox Church contributes to the favourable profiles of several biomarkers of health among this sample of monks. The fasting rituals described are an important component of the traditional diet of Crete and should be emphasised in nutrition education programmes promoting this Mediterranean eating pattern.

Estimations of daily energy and nutrient availability based on nationally representative household budget survey data. The Data Food Networking (DAFNE) project.

PubMed

Naska, A; Oikonomou, E; Trichopoulou, A; Wagner, K; Gedrich, K

2007-12-01

To describe a cost-efficient method for estimating energy and nutrient availability using household budget survey (HBS) data. Four different approaches were tested and the results were compared with published nutrient intake data. The selected method was exemplarily applied in German and Greek data. Germany, 1998; Greece, 1998/99. Nationally representative HBSs. Comparisons showed that HBS-based estimates were generally close to intake data when results were presented as contributions to daily energy intake. Daily energy and protein availabilities were similar in Germany and Greece. Differences were observed in the availability of carbohydrates (German households reported a 5 percentage points higher contribution to daily energy availability) and lipids (Greek households recorded higher values for total fat, but lower values for saturated fat). Meat, added lipids and potatoes were important energy suppliers in Germany, whereas in Greece the first three energy suppliers were added lipids, cereals and meat. In both countries, meat, cereals, milk and cheese were important protein sources and cereals, potatoes, fruits and nuts contributed more than 60% of the daily carbohydrate availability. Added lipids were the major source of fat in the daily diet of both countries, but their contribution amounted to less than one-third in Germany and two-thirds in Greece. National HBS data can be used for monitoring and comparing nutrient availability among representative population samples of different countries. The ground is set for the development of a harmonised food composition table to be applied to HBS food data at international level.

The influence of microtopography on soil nutrients in created mitigation wetlands

USGS Publications Warehouse

Moser, K.F.; Ahn, C.; Noe, G.B.

2009-01-01

This study explores the relationship between microtopography and soil nutrients (and trace elements), comparing results for created and reference wetlands in Virginia, and examining the effects of disking during wetland creation. Replicate multiscale tangentially conjoined circular transects were used to quantify microtopography both in terms of elevation and by two microtopographic indices. Corresponding soil samples were analyzed for moisture content, total C and N, KCl-extractable NH4-N and NO3-N, and Mehlich-3 extractable P, Ca, Mg, K, Al, Fe, and Mn. Means and variances of soil nutrient/element concentrations were compared between created and natural wetlands and between disked and nondisked created wetlands. Natural sites had higher and more variable soil moisture, higher extractable P and Fe, lower Mn than created wetlands, and comparatively high variability in nutrient concentrations. Disked sites had higher soil moisture, NH4-N, Fe, and Mn than did nondisked sites. Consistently low variances (Levene test for inequality) suggested that nondisked sites had minimal nutrient heterogeneity. Across sites, low P availability was inferred by the molar ratio (Mehlich-3 [P/(Al + Fe)] < 0.06); strong intercorrelations among total C, total N, and extractable Fe, Al, and P suggested that humic-metal-P complexes may be important for P retention and availability. Correlations between nutrient/element concentrations and microtopographic indices suggested increased Mn and decreased K and Al availability with increased surface roughness. Disking appears to enhance water and nutrient retention, as well as nutrient heterogeneity otherwise absent from created wetlands, thus potentially promoting ecosystem development. ?? 2008 Society for Ecological Restoration International.

Introducing mixotrophy into a biogeochemical model describing an eutrophied coastal ecosystem: The Southern North Sea

NASA Astrophysics Data System (ADS)

Ghyoot, Caroline; Lancelot, Christiane; Flynn, Kevin J.; Mitra, Aditee; Gypens, Nathalie

2017-04-01

Most biogeochemical/ecological models divide planktonic protists between phototrophs (phytoplankton) and heterotrophs (zooplankton). However, a large number of planktonic protists are able to combine several mechanisms of carbon and nutrient acquisition. Not representing these multiple mechanisms in biogeochemical/ecological models describing eutrophied coastal ecosystems can potentially lead to different conclusions regarding ecosystem functioning, especially regarding the success of harmful algae, which are often reported as mixotrophic. This modelling study investigates, for the first time, the implications for trophic dynamics of including 3 contrasting forms of mixotrophy, namely osmotrophy (using alkaline phosphatase activity, APA), non-constitutive mixotrophy (acquired phototrophy by microzooplankton) and also constitutive mixotrophy. The application is in the Southern North Sea, an ecosystem that faced, between 1985 and 2005, a significant increase in the nutrient supply N:P ratio (from 31 to 81 mole N:P). The comparison with a traditional model shows that, when the winter N:P ratio in the Southern North Sea is above 22 molN molP-1 (as occurred from mid-1990s), APA allows a 3 to 32% increase of annual gross primary production (GPP). In result of the higher GPP, the annual sedimentation increases as well as the bacterial production. By contrast, APA does not affect the export of matter to higher trophic levels because the increased GPP is mainly due to Phaeocystis colonies, which are not grazed by copepods. The effect of non-constitutive mixotrophy depends on light and affects the ecosystem functioning in terms of annual GPP, transfer to higher trophic levels, sedimentation, and nutrient remineralisation. Constitutive mixotrophy in nanoflagellates appears to have little influence on this ecosystem functioning. An important conclusion from this work is that different forms of mixotrophy have different impacts on system dynamics and it is thus important to describe such differences in an appropriate fashion.

Introducing mixotrophy into a biogeochemical model describing an eutrophied coastal ecosystem: The Southern North Sea

NASA Astrophysics Data System (ADS)

Ghyoot, Caroline; Lancelot, Christiane; Flynn, Kevin J.; Mitra, Aditee; Gypens, Nathalie

2017-09-01

Most biogeochemical/ecological models divide planktonic protists between phototrophs (phytoplankton) and heterotrophs (zooplankton). However, a large number of planktonic protists are able to combine several mechanisms of carbon and nutrient acquisition. Not representing these multiple mechanisms in biogeochemical/ecological models describing eutrophied coastal ecosystems can potentially lead to different conclusions regarding ecosystem functioning, especially regarding the success of harmful algae, which are often reported as mixotrophic. This modelling study investigates the implications for trophic dynamics of including 3 contrasting forms of mixotrophy, namely osmotrophy (using alkaline phosphatase activity, APA), non-constitutive mixotrophy (acquired phototrophy by microzooplankton) and also constitutive mixotrophy. The application is in the Southern North Sea, an ecosystem that faced, between 1985 and 2005, a significant increase in the nutrient supply N:P ratio (from 31 to 81 mol N:P). The comparison with a traditional model shows that, when the winter N:P ratio in the Southern North Sea is above 22 molN molP-1 (as occurred from mid-1990s), APA allows a 3-32% increase of annual gross primary production (GPP). In result of the higher GPP, the annual sedimentation increases as well as the bacterial production. By contrast, APA does not affect the export of matter to higher trophic levels because the increased GPP is mainly due to Phaeocystis colonies, which are not grazed by copepods. Under high irradiance, non-constitutive mixotrophy appreciably increases annual GPP, transfer to higher trophic levels, sedimentation, and nutrient remineralisation. In this ecosystem, non-constitutive mixotrophy is also observed to have an indirect stimulating effect on diatoms. Constitutive mixotrophy in nanoflagellates appears to have little influence on this ecosystem functioning. An important conclusion from this work is that contrasting forms of mixotrophy have different impacts on system dynamics and, due to the complex interactions in the ecosystem, their combined effect is not exactly the addition of the effects individually observed. It is thus important to describe such contrasting forms in an appropriate fashion.

Effect of polyethylene glycol 4000 supplementation on the performance of yearling male Pedi goats fed dietary mixture levels of Acacia karroo leaf meal and Setaria verticillata grass hay.

PubMed

Brown, David; Ng'ambi, Jones W

2017-06-01

Eighteen yearling male Pedi goats weighing 21.7 ± 3.1 kg were used in a 42-day trial in a 2 (Acacia karroo leaf meal levels) × 3 (levels of PEG 4000) factorial arrangement in a completely randomized design to determine PEG 4000 supplementation levels for optimal productivity of indigenous Pedi goats fed different mixture levels of A. karroo leaf meal and Setaria verticillata (L.) P.Beauv. grass hay. Each goat was supplemented with 0, 23 or 30 g of PEG 4000 per day in addition to dietary mixture of A. karroo and S. verticillata hay. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on nutrient intake of goats. However, a diet × PEG (P < 0.05) was observed for intake of all nutrients studied. Dry matter, OM, NDF and ADF intakes per goat were optimized at PEG 4000 supplementation levels of 19.62, 19.62, 19.61 and 19.53 g/goat/day, respectively, for diets containing 20% A. karroo leaf meal. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on the apparent digestibility of all nutrients. The dietary inclusion level of A. karroo leaf meal at 20% improved (P < 0.05) DM, OM, CP, NDF and ADF digestibility of goats. Crude protein digestibility was optimized at a PEG 4000 supplementation level of 15.78 g/goat/day. Dietary mixture level and PEG 4000 supplementation had no effect (P > 0.05) on final weights of Pedi goats. Similar results were observed for blood urea and glucose concentrations of yearling male Pedi goats. However, daily body weight gain was higher (P < 0.05) in goats fed 50% A. karroo leaf meal than those on 20% inclusion level. Polyethylene glycol 4000 has potential to improve the feeding value of tanninifeorus A. karroo leaf meal.

Relation of watershed setting and stream nutrient yields at selected sites in central and eastern North Carolina, 1997-2008

USGS Publications Warehouse

Harden, Stephen L.; Cuffney, Thomas F.; Terziotti, Silvia; Kolb, Katharine R.

2013-01-01

Data collected between 1997 and 2008 at 48 stream sites were used to characterize relations between watershed settings and stream nutrient yields throughout central and eastern North Carolina. The focus of the investigation was to identify environmental variables in watersheds that influence nutrient export for supporting the development and prioritization of management strategies for restoring nutrient-impaired streams. Nutrient concentration data and streamflow data compiled for the 1997 to 2008 study period were used to compute stream yields of nitrate, total nitrogen (N), and total phosphorus (P) for each study site. Compiled environmental data (including variables for land cover, hydrologic soil groups, base-flow index, streams, wastewater treatment facilities, and concentrated animal feeding operations) were used to characterize the watershed settings for the study sites. Data for the environmental variables were analyzed in combination with the stream nutrient yields to explore relations based on watershed characteristics and to evaluate whether particular variables were useful indicators of watersheds having relatively higher or lower potential for exporting nutrients. Data evaluations included an examination of median annual nutrient yields based on a watershed land-use classification scheme developed as part of the study. An initial examination of the data indicated that the highest median annual nutrient yields occurred at both agricultural and urban sites, especially for urban sites having large percentages of point-source flow contributions to the streams. The results of statistical testing identified significant differences in annual nutrient yields when sites were analyzed on the basis of watershed land-use category. When statistical differences in median annual yields were noted, the results for nitrate, total N, and total P were similar in that highly urbanized watersheds (greater than 30 percent developed land use) and (or) watersheds with greater than 10 percent point-source flow contributions to streamflow had higher yields relative to undeveloped watersheds (having less than 10 and 15 percent developed and agricultural land uses, respectively) and watersheds with relatively low agricultural land use (between 15 and 30 percent). The statistical tests further indicated that the median annual yields for total P were statistically higher for watersheds with high agricultural land use (greater than 30 percent) compared to the undeveloped watersheds and watersheds with low agricultural land use. The total P yields also were higher for watersheds with low urban land use (between 10 and 30 percent developed land) compared to the undeveloped watersheds. The study data indicate that grouping and examining stream nutrient yields based on the land-use classifications used in this report can be useful for characterizing relations between watershed settings and nutrient yields in streams located throughout central and eastern North Carolina. Compiled study data also were analyzed with four regression tree models as a means of determining which watershed environmental variables or combination of variables result in basins that are likely to have high or low nutrient yields. The regression tree analyses indicated that some of the environmental variables examined in this study were useful for predicting yields of nitrate, total N, and total P. When the median annual nutrient yields for all 48 sites were evaluated as a group (Model 1), annual point-source flow yields had the greatest influence on nitrate and total N yields observed in streams, and annual streamflow yields had the greatest influence on yields of total P. The Model 1 results indicated that watersheds with higher annual point-source flow yields had higher annual yields of nitrate and total N, and watersheds with higher annual streamflow yields had higher annual yields of total P. When sites with high point-source flows (greater than 10 percent of total streamflow) were excluded from the regression tree analyses (Models 2–4), the percentage of forested land in the watersheds was identified as the primary environmental variable influencing stream yields for both total N and total P. Models 2, 3 and 4 did not identify any watershed environmental variables that could adequately explain the observed variability in the nitrate yields among the set of sites examined by each of these models. The results for Models 2, 3, and 4 indicated that watersheds with higher percentages of forested land had lower annual total N and total P yields compared to watersheds with lower percentages of forested land, which had higher median annual total N and total P yields. Additional environmental variables determined to further influence the stream nutrient yields included median annual percentage of point-source flow contributions to the streams, variables of land cover (percentage of forested land, agricultural land, and (or) forested land plus wetlands) in the watershed and (or) in the stream buffer, and drainage area. The regression tree models can serve as a tool for relating differences in select watershed attributes to differences in stream yields of nitrate, total N, and total P, which can provide beneficial information for improving nutrient management in streams throughout North Carolina and for reducing nutrient loads to coastal waters.

Cool tadpoles from Arctic environments waste fewer nutrients - high gross growth efficiencies lead to low consumer-mediated nutrient recycling in the North.

PubMed

Liess, Antonia; Guo, Junwen; Lind, Martin I; Rowe, Owen

2015-11-01

Endothermic organisms can adapt to short growing seasons, low temperatures and nutrient limitation by developing high growth rates and high gross growth efficiencies (GGEs). Animals with high GGEs are better at assimilating limiting nutrients and thus should recycle (or lose) fewer nutrients. Longer guts in relation to body mass may facilitate higher GGE under resource limitation. Within the context of ecological stoichiometry theory, this study combines ecology with evolution by relating latitudinal life-history adaptations in GGE, mediated by gut length, to its ecosystem consequences, such as consumer-mediated nutrient recycling. In common garden experiments, we raised Rana temporaria tadpoles from two regions (Arctic/Boreal) under two temperature regimes (18/23 °C) crossed with two food quality treatments (high/low-nitrogen content). We measured tadpole GGEs, total nutrient loss (excretion + egestion) rates and gut length during ontogeny. In order to maintain their elemental balance, tadpoles fed low-nitrogen (N) food had lower N excretion rates and higher total phosphorous (P) loss rates than tadpoles fed high-quality food. In accordance with expectations, Arctic tadpoles had higher GGEs and lower N loss rates than their low-latitude conspecifics, especially when fed low-N food, but only in ambient temperature treatments. Arctic tadpoles also had relatively longer guts than Boreal tadpoles during early development. That temperature and food quality interacted with tadpole region of origin in affecting tadpole GGEs, nutrient loss rates and relative gut length, suggests evolved adaptation to temperature and resource differences. With future climate change, mean annual temperatures will increase. Additionally, species and genotypes will migrate north. This will change the functioning of Boreal and Arctic ecosystems by affecting consumer-mediated nutrient recycling and thus affect nutrient dynamics in general. Our study shows that evolved latitudinal adaption can change key ecosystem functions. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Longitudinal changes in microbial planktonic communities of a French river in relation to pesticide and nutrient inputs.

PubMed

Pesce, Stéphane; Fajon, Céline; Bardot, Corinne; Bonnemoy, Frédérique; Portelli, Christophe; Bohatier, Jacques

2008-02-18

To determine the effects of anthropic activities on river planktonic microbial populations, monthly water samples were collected for 11 months from two sampling sites characterized by differing nutrient and pesticide levels. The difference in trophic level between the two stations was particularly pronounced from May to November. Total pesticide concentrations were notably higher at the downstream station from April to October with a clear predominance of herbicide residues, especially the glyphosate metabolite aminomethylphosphonic acid (AMPA). From spring, algal biomass and density were favored by the high orthophosphate concentrations recorded at the downstream location. However, isolated drops in algal biomass were recorded at this sampling station, suggesting an adverse effect of herbicides on algal communities. No major difference was observed in bacterial heterotrophic production, density, or activity (CTC reduction) between the two sampling stations. No major variation was detected using the fluorescent in situ hybridization (FISH) method, but shifts in bacterial community composition were recorded by PCR-TTGE analysis at the downstream station following high nutrient and pesticide inputs. However, outside the main anthropic pollution period, the water's chemical properties and planktonic microbial communities were very similar at the two sampling sites, suggesting a high recovery potential for this lotic system.

Wastewater infrastructure for small cities in an urbanizing world: integrating protection of human health and the environment with resource recovery and food security.

PubMed

Verbyla, Matthew E; Oakley, Stewart M; Mihelcic, James R

2013-04-16

The majority of population growth in developing countries will occur in small cities closely linked to agricultural zones, with poor access to water and sanitation. Wastewater management priorities in these regions will be different from those in larger cities and developed countries. Two wastewater treatment systems in Bolivia, one with an upflow anaerobic sludge blanket (UASB) reactor and polishing ponds, the other with three stabilization ponds, are assessed to determine their resource recovery potential. The UASB reactor produces biogas with 500-650 MJ per day. In six months, both systems discharge wastewater with the same mass of nutrients as fertilizers used to produce crops containing 10-75 days' worth of the recommended food energy intake for each person using the system. Both systems also discharge detectable levels of helminth eggs, Giardia cysts, and Cryptosporidium oocysts, but the UASB reactor system discharges higher concentrations, implying limited reuse potential. From a regional management standpoint, small cities should not expend resources to treat wastewater to levels suitable for discharge into surface waters. Rather, they should focus on removing pathogens to reclaim water and nutrients. Biogas recovery may be a priority that should be subservient to water and nutrient recovery in these settings.

The spatial variability of nitrogen and phosphorus concentration in a sand aquifer influenced by onsite sewage treatment and disposal systems: a case study on St. George Island, Florida.

PubMed

Corbet, D Reide; Dillon, Kevin; Burnett, William; Schaefer, Geoff

2002-01-01

Groundwater from a shallow freshwater lens on St. George Island, a barrier island located in the Panhandle of Florida, eventually discharges into Apalachicola Bay or the Gulf of Mexico. Nutrient concentrations in groundwaters were monitored downfield from three onsite sewage treatment and disposal systems (OSTDS) on the island. Estimates of natural groundwater nutrient concentrations were obtained from an adjacent uninhabited island. Silicate, which was significantly higher in the imported drinking water relative to the surficial aquifer on St. George Island (12.2+/-1.9 mg Si l(-1) and 2.9+/-0.2 mg Si l(-1), respectively), was used as a natural conservative tracer. Our observations showed that nitrogen concentrations were attenuated to a greater extent than that of phosphorus relative to the conservative tracer. At the current setback distance (23 m), both nitrogen and phosphate concentrations are still elevated above natural levels by as much as 2 and 7 times, respectively. Increasing the setback distance to 50 m and raising the drainfields 1 m above the ground surface could reduce nutrient levels to natural concentrations (1.1+/-0.1 mg N l(-1), 0.20+/-0.02 mg P l(-1)).

Multivitamin-multimineral supplements: who uses them?

PubMed

Rock, Cheryl L

2007-01-01

Dietary supplement use is increasingly common in the United States. Multivitamin formulations with or without minerals are typically the most common type of dietary supplement reported in surveys and studies that collect data relating to dietary supplement use. In the National Health and Nutrition Examination Survey (NHANES) 1999-2000, 52% of adults reported taking a dietary supplement in the past month, and 35% reported regular use of a multivitamin-multimineral (MVMM) product. NHANES III data indicate an overall prevalence of dietary supplement usage of 40%, with prevalence rates of 35% in NHANES II and 23% in NHANES I. Women (versus men), older age groups, non-Hispanic whites (versus non-Hispanic blacks or Mexican Americans), and those with a higher education level, lower body mass index, higher physical activity level, and more frequent consumption of wine had a greater likelihood of reporting use of MVMM supplements in NHANES 1999-2000. Data from children suggest a similar prevalence rate, but lower prevalence rates of usage were reported in studies of adolescents. Individuals who use dietary supplements (including MVMM formulations) generally report higher dietary nutrient intakes and healthier diets in studies in which dietary data were also collected. Among adults with a history of breast or prostate cancer, usage rates for dietary supplements in general and MVMMs are considerably higher (eg, 56-57% for MVMMs), and these subgroups are more likely to also report use of single vitamin and mineral supplements. Thus, MVMM use contributes a considerable proportion of nutrient intakes in the United States and may contribute to risk of excessive intakes.

Eutrophication processes in the Gulf of Eilat (Aqaba), Red-Sea, and their effects on the coral reef ecosystem

NASA Astrophysics Data System (ADS)

Erez, J.; Iluz, D.; Zakai, D.; Silverman, J.; Lazar, B.

2003-04-01

In the past few years (since 1998) an on going eutrophication process has been observed in the Northern Gulf of Eilat. Nutrient levels have increased both in the deep and in the coastal waters. In parallel, the phytoplankton productivity in the open sea has increased by a factor of 3 from 100 to 300 gCm-2y-1. The main source of these nutrients is caged fish farms moored near the North Beach, which over the past 5 years have released more then 300 tons N annually. Surface circulation transports part of the nutrient-algae rich surface water along the Israeli coast, where they have been detected during the stratified period near the coral reef in the Nature Reserve. The bulk of the nutrients released from the fish cages are taken up by phytoplankton and increase the productivity of the pelagic ecosystem. Phytoplankton sinking and zooplankton grazing transport these nutrients to the deep water, below the thermocline where we observed a 50% increase in nitrate and phosphate concentrations relative to the previous decade. During the winter, vertical mixing brings these nutrients to the photic zone where massive blooms of benthic algae are observed in the coastal zone. These blooms are often associated with high coral mortality and have reduced live coral cover by 50% in the winter of 2000. Calcification rates of the reef ecosystem have decreased by a factor of 3--4 compared to earlier measurements in 1989--1991 while the photosynthesis to respiration ratio have increased from 1.0 to values higher then 1.5. These observations demonstrate the detrimental effects of anthropogenic nutrient enrichment on coral reefs.

High nutrient concentration and temperature alleviated formation of large colonies of Microcystis: Evidence from field investigations and laboratory experiments.

PubMed

Zhu, Wei; Zhou, Xiaohua; Chen, Huaimin; Gao, Li; Xiao, Man; Li, Ming

2016-09-15

Correlations between Microcystis colony size and environmental factors were investigated in Meiliang Bay and Gonghu Bay of Lake Taihu (China) from 2011 to 2013. Compared with Gonghu Bay, both nutrient concentrations and Microcystis colony sizes were greater in Meiliang Bay. The median colony size (D50: 50% of the total mass of particles smaller than this size) increased from April to August and then decreased until November. In both bays, the average D50 of Microcystis colonies were <100 μm in spring, but colonies within moderate-size (100-500 μm) dominated in summer. The differences in colony size in Meiliang Bay and Gonghu Bay were probably due to horizontal drift driven by the prevailing south wind in summer. Redundancy analysis (RDA) of field data indicated that colony size was negatively related to nutrient concentrations but positively related to air temperature, suggesting that low nutrient concentrations and high air temperature promoted formation of large colonies. To validate the field survey, Microcystis colonies collected from Lake Taihu were cultured at different temperatures (15, 20, 25 and 30 °C) under high and low nutrient concentrations for 9 days. The size of Microcystis colonies significantly decreased when temperature was above 20 °C but had no significant change at 15 °C. The differences in temperature effects on colony formation shown from field and laboratory suggested that the larger colonies in summer were probably due to the longer growth period rather than the higher air temperature and light intensity. In addition, colony size decreased more significantly at high nutrient levels. Therefore, it could be concluded that high nutrient concentration and temperature may alleviate formation of large colonies of Microcystis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bark analysis as a guide to cassava nutrition in Sierra Leone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godfrey-Sam-Aggrey, W.; Garber, M.J.

1979-01-01

Cassava main stem barks from two experiments in which similar fertilizers were applied directly in a 2/sup 5/ confounded factorial design were analyzed and the bark nutrients used as a guide to cassava nutrition. The application of multiple regression analysis to the respective root yields and bark nutrient concentrations enable nutrient levels and optimum adjusted root yields to be derived. Differences in bark nutrient concentrations reflected soil fertility levels. Bark analysis and the application of multiple regression analysis to root yields and bark nutrients appear to be useful tools for predicting fertilizer recommendations for cassava production.

Combined effects between temporal heterogeneity of water supply, nutrient level, and population density on biomass of four broadly distributed herbaceous species.

PubMed

Hagiwara, Yousuke; Kachi, Naoki; Suzuki, Jun-Ichirou

2012-01-01

Temporal heterogeneity of water supply affects grassland community productivity and it can interact with nutrient level and intraspecific competition. To understand community responses, the responses of individual species to water heterogeneity must be evaluated while considering the interactions of this heterogeneity with nutrient levels and population density. We compared responses of four herbaceous species grown in monocultures to various combinations of water heterogeneity, nutrient level, and population density: two grasses (Cynodon dactylon and Lolium perenne), a forb (Artemisia princeps), and a legume (Trifolium repens). Treatment effects on shoot and root biomass were analyzed. In all four species, shoot biomass was larger under homogeneous than under heterogeneous water supply. Shoot responses of L. perenne tended to be greater at high nutrient levels. Although root biomass was also larger under homogeneous water supply, effects of water heterogeneity on root biomass were not significant in the grasses. Trifolium repens showed marked root responses, particularly at high population density. Although greater shoot and root growth under homogeneous water supply appears to be a general trend among herbaceous species, our results suggested differences among species could be found in the degree of response to water heterogeneity and its interactions with nutrient level and intraspecific competition.

What's Upstream? GIS's critical role in developing nutrient ...

EPA Pesticide Factsheets

Eutrophication due to excess levels of nitrogen and phosphorus can seriously impair ecological function in estuaries. Protective criteria for nutrients are difficult to establish because the source can vary spatially and seasonally, originate either from the watershed or the ocean, and be natural or anthropogenic. GIS tools and processes can help in developing nutrient criteria by establishing reference conditions representative of natural background nutrient levels. Along the Oregon Coast in the Pacific Northwest, the primary source of nutrients in the wet season (November-April) is generally riverine. We delineated and extracted explicit spatial data from watersheds upstream of riverine water quality monitoring stations for parametric comparison to recorded nutrient levels. The SPARROW model (Wise and Johnson, 2011) was used to estimate relative contributions of nutrient sources at each station. Both raster and vector spatial data were used and include land use / land cover, demography, geology, terrain, precipitation and forest type. The relationships of nutrients to spatial data were then explored as an approach to establishing the reference expectation. The abstract introduces Geographic Information Systems (GIS) tools and processes employed for research conducted under the Safe and Sustainable Water Resources (SSWR) Task 2.3A, entitled “Nutrient Management for Sustainability of Aquatic Ecosystems.” One of the goals of the EPA Office of Water is to

Parasite and nutrient enrichment effects on Daphnia interspecific competition.

PubMed

Decaestecker, Ellen; Verreydt, Dino; De Meester, Luc; Declerck, Steven A J

2015-05-01

Increased productivity due to nutrient enrichment is hypothesized to affect density-dependent processes, such as transmission success of horizontally transmitting parasites. Changes in nutrient availability can also modify the stoichiometry and condition of individual hosts, which may affect their susceptibility for parasites as well as the growth conditions for parasites within the host. Consequently, if not balanced by increased host immuno-competence or life history responses, changes in the magnitude of parasite effects with increasing nutrient availability are expected. If these parasite effects are host-species specific, this may lead to shifts in the host community structure. We here used the Daphnia- parasite model system to study the effect of nutrient enrichment on parasite-mediated competition in experimental mesocosms. In the absence of parasites, D. magna was competitively dominant to D. pulex at both low and high nutrient levels. Introduction of parasites resulted in infections of D. magna, but not of D. pulex and, as such, reversed the competitive hierarchy between these two species. Nutrient addition resulted in an increased prevalence and infection intensity of some of the parasites on D. magna. However, there was no evidence that high nutrient levels enhanced negative effects of parasites on the hosts. Costs associated with parasite infections may have been compensated by better growth conditions for D. magna in the presence of high nutrient levels.

Nutritional assessment using stable isotope ratios of carbon and nitrogen in the scalp hair of geriatric patients who received enteral and parenteral nutrition formulas.

PubMed

Hayasaka, M; Ogasawara, H; Hotta, Y; Tsukagoshi, K; Kimura, O; Kura, T; Tarumi, T; Muramatsu, H; Endo, T

2017-12-01

The δ 13 C and δ 15 N values in the scalp hair of geriatric patients in Japan who received the enteral or parenteral nutrition formula were measured to assess nutritional status. The relations among δ 13 C, δ 15 N, calorie intake, BMI, albumin concentration, total cholesterol (T-CHO) and geriatric nutritional risk index (GNRI) in the patients were investigated. Furthermore, the enrichment of δ 13 C and δ 15 N from the nutrients to the hair was investigated. The δ 13 C values in the hair of patients who received enteral nutrition decreased with decreases in the calories received, while the δ 15 N values increased, suggesting malnutrition in some patients with a low calorie intake due to a negative nitrogen balance. The distribution of patients with a low calorie intake (below 20 kcal/kg/day) when δ 13 C was plotted against δ 15 N differed from that of control subjects, but the distribution of patients with a high calorie intake (above 20 kcal/kg/day) was similar to that of control subjects. No significant differences were observed in BMI, albumin concentration, T-CHO or GNRI between the low and high calorie groups. The enrichment of δ 13 C and δ 15 N from the enteral nutrients to the hair were inversely correlated with the δ 13 C and δ 15 N in the enteral nutrients. The enrichment levels of δ 13 C and δ 15 N tended to be higher and lower, respectively, in the high calorie group. On the other hand, the δ 13 C and δ 15 N values in the hair of patients who received parenteral nutrition were higher and lower than those in the control subjects and in the patients who received enteral nutrition, respectively, reflecting the higher δ 13 C and lower δ 15 N contents of the parenteral nutrients. The δ 13 C and δ 15 N values in the hair of patients who received enteral nutrition may be effective indicators for evaluating the long-term nutritional status of geriatric patients. A calorie intake of 20 kcal/kg/day may be a cut-off value for malnutrition in Japanese geriatric patients receiving enteral nutrition. However, caution is necessary when dealing with patients switching from parental nutrition as parenteral nutrition resulted in different changes in δ 13 C and δ 15 N. The enrichment levels of δ 13 C and δ 15 N from the enteral nutrients to the hair may be inversely correlated with the δ 13 C and δ 15 N values of enteral nutrients and vary according to the calorie intake. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Exponential fertilization of Pinus monticola seedlings: nutrient uptake efficiency, leaching fractions, and early outplanting performance

Treesearch

R. Kasten Dumroese; Deborah S. Page-Dumroese; K. Francis Salifu; Douglass F. Jacobs

2005-01-01

We evaluated nutrient uptake efficiency and subsequent leaching fractions for western white pine (Pinus monticola Dougl. ex D. Don) seedlings grown with exponentially increasing or conventional (constant) fertilization in a greenhouse. Conventional fertilization was associated with higher leachate electrical conductivity and greater nutrient losses,...

The relative importance of oceanic nutrient inputs for Bass Harbor Marsh Estuary at Acadia National Park, Maine

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Fuller, Christopher; Glibert, Patricia; Sturtevant, Luke

2014-01-01

The U.S. Geological Survey and Acadia National Park (ANP) collaborated on a study of nutrient inputs into Bass Harbor Marsh Estuary on Mount Desert Island, Maine, to better understand ongoing eutrophication, oceanic nutrient inputs, and potential management solutions. This report includes the estimation of loads of nitrate, ammonia, total dissolved nitrogen, and total dissolved phosphorus to the estuary derived from runoff within the watershed and oceanic inputs during summers 2011 and 2012. Nutrient outputs from the estuary were also monitored, and nutrient inputs in direct precipitation to the estuary were calculated. Specific conductance, water temperature, and turbidity were monitored at the estuary outlet. This report presents a first-order analysis of the potential effects of projected sea-level rise on the inundated area and estuary volume. Historical aerial photographs were used to investigate the possibility of widening of the estuary channel over time. The scope of this report also includes analysis of sediment cores collected from the estuary and fringing marsh surfaces to assess the sediment mass accumulation rate. Median concentrations of nitrate, ammonium, and total dissolved phosphorus on the flood tide were approximately 25 percent higher than on the ebb tide during the 2011 and 2012 summer seasons. Higher concentrations on the flood tide suggest net assimilation of these nutrients in biota within the estuary. The dissolved organic nitrogen fraction dominated the dissolved nitrogen fraction in all tributaries. The median concentration of dissolved organic nitrogen was about twice as high on the on the ebb tide than the flood tide, indicating net export of dissolved organic nitrogen from the estuary. The weekly total oceanic inputs of nitrate, ammonium, and total dissolved phosphorus to the estuary were usually much larger than inputs from runoff or direct precipitation. The estuary was a net sink for nitrate and ammonium in most weeks during both years. Oceanic inputs of nitrate and ammonium were an important source of inorganic nitrogen to the estuary in both years. In both years, the total seasonal inputs of ammonium to the estuary in flood tides were much larger than the inputs from watershed runoff or direct precipitation. In 2011, the total seasonal input of nitrate from flood tides to the estuary was more than twice as large the inputs from watershed runoff and precipitation, but in 2012, the inputs from flood tides were only marginally larger than the inputs from watershed runoff and precipitation. Turbidity was measured intermittently in 2012, and the pattern that emerged from the measurements indicated that the estuary was a source of particulate matter to the ocean rather than the ocean being a source to the estuary. From the nutrient budgets determined for the estuary it is evident that oceanic sources of nitrate and ammonium are an important part of the supply of nutrients that are contributing to the growth of macroalgae in the estuary. The relative importance of these oceanic nutrients compared with sources within the watershed typically increases as the summer progresses and runoff decreases. It is likely that rising sea levels, estimated by the National Oceanic and Atmospheric Administration to be 11 centimeters from 1950 through 2006 in nearby Bar Harbor, have resulted in an increase in oceanic inputs (tidal volume and nutrients derived from oceanic sources).

Discretionary fortification--a public health perspective.

PubMed

Valerie, Tarasuk

2014-10-17

'Discretionary fortification' refers to the addition of vitamins and minerals to foods at the discretion of manufacturers for marketing purposes, but not as part of a planned public health intervention. While the nutrients added may correspond to needs in the population, an examination of novel beverages sold in Toronto supermarkets revealed added nutrients for which there is little or no evidence of inadequacy in the population. This is consistent with the variable effects of manufacturer-driven fortification on nutrient adequacy observed in the US. Nutrient intakes in excess of Tolerable Upper Intake Levels are now observed in the context of supplement use and high levels of consumption of fortified foods. Expanding discretionary fortification can only increase nutrient exposures, but any health risks associated with chronically high nutrient loads from fortification and supplementation remain to be discovered. Regulatory bodies are focused on the establishment of safe levels of nutrient addition, but their estimation procedures are fraught with untested assumptions and data limitations. The task of determining the benefits of discretionary fortification is being left to consumers, but the nutrition information available to them is insufficient to allow for differentiation of potentially beneficial fortification from gratuitous nutrient additions.

Wastewater and Sludge Nutrient Utilization in Forest Ecosystems

Treesearch

D.G. Brockway; D.H. Urie; P.V. Nguyen; J.B. Hart

1986-01-01

Although forest ecosystems have evolved efficient mechanisms to assimilate and retain modest levels of annual geochemical input, their productivity is frequently limited by low levels of available nutrients. A review of research studies conducted in the major U.S. forest regions indicates that the nutrients and organic matter in wastewater and sludge representa...

Oxygen, carbon, and nutrient exchanges at the sediment-water interface in the Mar Piccolo of Taranto (Ionian Sea, southern Italy).

PubMed

De Vittor, Cinzia; Relitti, Federica; Kralj, Martina; Covelli, Stefano; Emili, Andrea

2016-07-01

In the shallow environment, the nutrient and carbon exchanges at the sediment-water interface contribute significantly to determine the trophic status of the whole water column. The intensity of the allochthonous input in a coastal environment subjected to strong anthropogenic pressures determines an increase in the benthic oxygen demand leading to depressed oxygen levels in the bottom waters. Anoxic conditions resulting from organic enrichment can enhance the exchange of nutrients between sediments and the overlying water. In the present study, carbon and nutrient fluxes at the sediment-water interface were measured at two experimental sites, one highly and one moderately contaminated, as reference point. In situ benthic flux measurements of dissolved species (O2, DIC, DOC, N-NO3 (-), N-NO2 (-), N-NH4 (+), P-PO4 (3-), Si-Si(OH)4, H2S) were conducted using benthic chambers. Furthermore, undisturbed sediment cores were collected for analyses of total and organic C, total N, and biopolymeric carbon (carbohydrates, proteins, and lipids) as well as of dissolved species in porewaters and supernatant in order to calculate the diffusive fluxes. The sediments were characterized by suboxic to anoxic conditions with redox values more negative in the highly contaminated site, which was also characterized by higher biopolymeric carbon content (most of all lipids), lower C/N ratios and generally higher diffusive fluxes, which could result in a higher release of contaminants. A great difference was observed between diffusive and in situ benthic fluxes suggesting the enhancing of fluxes by bioturbation and the occurrence of biogeochemically important processes at the sediment-water interface. The multi-contamination of both inorganic and organic pollutants, in the sediments of the Mar Piccolo of Taranto (declared SIN in 1998), potentially transferable to the water column and to the aquatic trophic chain, is of serious concern for its ecological relevance, also considering the widespread fishing and mussel farming activities in the area.

Micronutrient mineral and folate content of Australian and imported dried fruit products.

PubMed

Bennett, Louise E; Singh, Davinder P; Clingeleffer, Peter R

2011-01-01

A selection of Australian and imported fresh and dried fruit products, including sultanas, Sunmuscats, Carina currants, Zante currants, apricots, and prunes, were analyzed for selected minerals (Ca, Mg, Na, S, B, Al, Fe, Mn, Cu, Zn, Mo, and Se), folate and vitamin C, and the capacity of dried fruits for dietary provision of these micronutrients evaluated. Micro-nutrients were concentrated by a factor of 3-5 in dried fruits compared with their fresh fruit counterparts and were consequently present in nutritionally significant levels, in contrast to fresh fruit. Australian dried sultanas, Carina currant, Zante currant, apricots, and prunes contained Cu, Fe, K, and Mn at levels of >20% of daily Required Dietary Intake (RDI, taken as the average for adult men and women as nominated by the Australian National Health and Medical Research Council) and Sunmuscats contained Cu, Fe, and K at >20% of RDI. All dried fruits studied contained boron in the range of 1.5 to 5.4 mg per 100 g; however, the RDI for boron has not been defined by the NHMRC at the present time. All sultanas and currants studied contained folate at levels of 10-20% of RDI per 100 g. Experimental drying methods significantly affected folate levels with higher folate content in non-ground versus ground-based drying methods. Of the micro-nutrients supplying >20% of RDI, folate represents a particular nutrient for which the mean daily intake of adult Australians is typically inadequate. This study shows that dried fruit consumption, in contrast with fresh fruit, can provide significant proportions of daily requirements of several micronutrients, particularly folate.

CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems

PubMed Central

Liu, Juxiu; Fang, Xiong; Deng, Qi; Han, Tianfeng; Huang, Wenjuan; Li, Yiyong

2015-01-01

As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change. PMID:25608664

Nutrient load can lead to enhanced CH4 fluxes through changes in vegetation, peat surface elevation and water table depth in ombrotrophic bog

NASA Astrophysics Data System (ADS)

Juutinen, Sari; Bubier, Jill; Larmola, Tuula; Humphreys, Elyn; Arnkil, Sini; Roy, Cameron; Moore, Tim

2016-04-01

Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands, particularly in temperate areas, affecting plant community composition, carbon (C) cycling, and microbial dynamics. It is vital to understand the temporal scales and mechanisms of the changes, because peatlands are long-term sinks of C, but sources of methane (CH4), an important greenhouse gas. Rainwater fed (ombrotrophic) bogs are considered to be vulnerable to nutrient loading due to their natural nutrient poor status. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, now for 11-16 years with N (NO3 NH4) at 0.6, 3.2, and 6.4 g N m-2 y-1 (~5, 10 and 20 times ambient N deposition during summer months) with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured CH4 fluxes with static chambers weekly from May to September 2015 and peat samples were incubated in laboratory to measure CH4 production and consumption potentials. Methane fluxes at the site were generally low, but after 16 years, mean CH4 emissions have increased and more than doubled in high nitrogen addition treatments if P and K input was also increased (3.2 and 6.4 g N m-2yr-1 with PK), owing to drastic changes in vegetation and soil moisture. Vegetation changes include a loss of Sphagnum moss and introduction of new species, typical to minerogenic mires, which together with increased decomposition have led to decreased surface elevation and to higher water table level relative to the surface. The trajectories indicate that the N only treatments may result in similar responses, but only over longer time scales. Elevated atmospheric deposition of nutrients to peatlands may increase loss of C not only due to changes in CO2 exchange but also due to enhanced CH4 emissions in peatlands through a complex suite of feedbacks and interactions among vegetation, microclimate, and microbial processes. It is uncertain, however, how the vegetation change continues due to collapsing surface and higher water table levels, and how that will affect future CH4 emissions and C balance.

Enhancement and inhibition of microbial activity in hydrocarbon- contaminated arctic soils: Implications for nutrient-amended bioremediation

USGS Publications Warehouse

Braddock, J.F.; Ruth, M.L.; Catterall, P.H.; Walworth, J.L.; McCarthy, K.A.

1997-01-01

Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (<1%) end low moisture (1-3%) contents. We examined the effects of nutrient additions on microorganisms in contaminated soil from this site in laboratory microcosms and in mesocosms incubated for 6 weeks in the field. Nitrogen was the major limiting nutrient in this system, but microbial populations and activity were maximally enhanced by additions of both nitrogen and phosphorus. When nutrients were added to soil in the field at three levels of N:P (100:45, 200:90, and 300:135 mg/kg soil), the greatest stimulation in microbial activity occurred at the lowest, rather than the highest, level of nutrient addition. The total soil-water potentials ranged from -2 to -15 bar with increasing levels of fertilizer. Semivolatile hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (<1%) and low moisture (1-3%) contents. We examined the effects of nutrient additions on microorganisms in contaminated soil from this site in laboratory microcosms and in mesocosms incubated for 6 weeks in the field. Nitrogen was the major limiting nutrient in this system, but microbial populations and activity were maximally enhanced by additions of both nitrogen and phosphorus. When nutrients were added to soil in the field at three levels of N:P (100:45, 200:90, and 300:135 mg/kg soil), the greatest stimulation in microbial activity occurred at the lowest, rather than the highest, level of nutrient addition. The total soil-water potentials ranged from -2 to -15 bar with increasing levels of fertilizer. Semi-volatile hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.

Nutrient Intake and Body Habitus After Spinal Cord Injury: An Analysis by Sex and Level of Injury

PubMed Central

Groah, Suzanne L; Nash, Mark S; Ljungberg, Inger H; Libin, Alexander; Hamm, Larry F; Ward, Emily; Burns, Patricia A; Enfield, Gwen

2009-01-01

Background/Objectives: To examine nutrient intake and body mass index (BMI) in the spinal cord injury (SCI) population according to level of injury and sex. Design: Cross-sectional study conducted at 2 SCI treatment centers. Participants/Methods: Seventy-three community-dwelling individuals with C5-T12 ASIA Impairment Scale (AIS) A or B SCI. Subjects were divided into 4 groups: male tetraplegia (N = 24), male paraplegia (N = 37), female tetraplegia (N = 1), and female paraplegia (N = 11). Mean age was 38 years; 84% were male; 34% were white, 41% were African American, and 25% were Hispanic. Participants completed a 4-day food log examining habitual diet. Dietary composition was analyzed using Food Processor II v 7.6 software. Results: Excluding the 1 woman with tetraplegia, total calorie intake for the other 3 groups was below observed values for the general population. The female paraplegia group tended to have a lower total calorie intake than the other groups, although macronutrient intake was within the recommended range. The male tetraplegia group, male paraplegia group, and the 1 woman with tetraplegia all had higher than recommended fat intake. Intake of several vitamins, minerals, and macronutrients did not meet recommended levels or were excessively low, whereas sodium and alcohol intake were elevated. Using adjusted BMI tables, 74.0% of individuals with SCI were overweight or obese. Conclusions: Women with paraplegia tended to maintain healthier diets, reflected by lower caloric and fat intakes, fewer key nutrients falling outside recommended guidelines, and less overweight or obesity. Individuals with tetraplegia tended to take in more calories and had higher BMIs, and using adjusted BMI, the majority of the population was overweight or obese. The majority of people with SCI would benefit from nutritional counseling to prevent emerging secondary conditions as the population with SCI ages. PMID:19264046

Seasonal variations of alkenones and UK37 in the Chesapeake Bay water column

USGS Publications Warehouse

Mercer, J.L.; Zhao, M.; Colman, Steven M.

2005-01-01

Alkenone unsaturation indices (UK37 and U K???37) have long been used as proxies for surface water temperature in the open ocean. Recent studies have suggested that in other marine environments, variables other than temperature may affect both the production of alkenones and the values of the indices. Here, we present the results of a reconnaissance field study in which alkenones were extracted from particulate matter filtered from the water column in Chesapeake Bay during 2000 and 2001. A multivariate analysis shows a strong positive correlation between UK37 (and UK???37) values and temperature, and a significant negative correlation between UK37 (and UK???37) values and nitrate concentrations. However, temperature and nitrate concentrations also co-vary significantly. The temperature vs. UK37 relationships (UK37=0.018 (T)-0.162, R2=0.84, UK???37=0.013 (T)-0.04, R2=0.80) have lower slopes than the open-ocean equations of Prahl et al. [1988. Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions. Geochimica et Cosmochimica Acta 52, 2303-2310] and Mu??ller et al. [1998. Calibration of the alkenone paleotemperature index UK???37 based on core-tops from the eastern South Atlantic and the global ocean (60??N-60??S). Geochimica et Cosmochimica Acta 62, 1757-1772], but are similar to the relationships found in controlled studies with elevated nutrient levels and higher nitrate:phosphate (N:P) ratios. This implies that high nutrient levels in Chesapeake Bay have either lowered the UK37 vs. temperature slope, or nutrient levels are the main controller of the U K37 index. In addition, particularly high abundances (>5% of total C37 alkenones) of the tetra-unsaturated ketone, C37:4, were found when water temperatures reached 25??C or higher, thus posing further questions about the controls on alkenone production as well as the biochemical roles of alkenones. ?? 2005 Elsevier Ltd. All rights reserved.

Distribution of periphytic algae in wetlands (Palm swamps, Cerrado), Brazil.

PubMed

Dunck, B; Nogueira, I S; Felisberto, S A

2013-05-01

The distribution of periphytic algae communities depends on various factors such as type of substrate, level of disturbance, nutrient availability and light. According to the prediction that impacts of anthropogenic activity provide changes in environmental characteristics, making impacted Palm swamps related to environmental changes such as deforestation and higher loads of nutrients via allochthonous, the hypothesis tested was: impacted Palm swamps have higher richness, density, biomass and biovolume of epiphytic algae. We evaluated the distribution and structure of epiphytic algae communities in 23 Palm swamps of Goiás State under different environmental impacts. The community structure attributes here analyzed were composition, richness, density, biomass and biovolume. This study revealed the importance of the environment on the distribution and structuration of algal communities, relating the higher values of richness, biomass and biovolume with impacted environments. Acidic waters and high concentration of silica were important factors in this study. Altogether 200 taxa were identified, and the zygnemaphycea was the group most representative in richness and biovolume, whereas the diatoms, in density of studied epiphyton. Impacted Palm swamps in agricultural area presented two indicator species, Gomphonema lagenula Kützing and Oedogonium sp, both related to mesotrophic to eutrophic conditions for total nitrogen concentrations of these environments.

Dietary supplement use and nutrient intake in HIV-infected persons.

PubMed

Hendricks, Kristy M; Sansavero, Mara; Houser, Robert F; Tang, Alice M; Wanke, Christine A

2007-04-01

Dietary supplement use was assessed in 368 HIV-infected patients enrolled in the Nutrition for Healthy Living cohort. The objective was to describe the dietary, demographic, and health characteristics of the HIV-infected persons who use different types of dietary supplements. Each patient was categorized in 1 of 4 dietary supplement groups. Extremes in intake of micronutrients were common. Men and women who consumed no supplements reported inadequate intakes of a number of micronutrients. Men using nonvitamin/nonmineral (NVNM) supplements had diets higher in fiber, protein, and 13 of 14 vitamins and minerals. Almost 90% of male NVNM supplement users ingested 1 or more vitamins or minerals in amounts above the tolerable upper limit. Male NVNM supplement users were more likely to be white, well educated, and receiving highly active antiretroviral therapy and more likely to have higher annual incomes, higher CD4 counts, and lower HIV RNA levels. HIV-infected women who were using NVNM supplements exhibited similar trends. Micronutrient inadequacy and excess are relatively common in persons living with HIV infection. Practitioners need to judiciously address optimal nutrient intake from both diet and dietary supplements in this population.

Alkaline phosphatase activity at the southwest coast of India: A comparison of locations differently affected by upwelling

NASA Astrophysics Data System (ADS)

Mamatha, S. S.; Malik, Ashish; Varik, Sandesh; Parvathi, V.; Jineesh, V. K.; Gauns, Mangesh U.; LokaBharathi, P. A.

2015-01-01

The realization of the potential importance of phosphorus (P) as a limiting nutrient in marine ecosystem is increasing globally. Hence, the contribution of biotic variables in mobilizing this nutrient would be relevant especially in productive coastal waters. As alkaline phosphatase activity (APA) indicates the status of P for primary production in aquatic environments, we asked the following question: is the level of APA indicative of P sufficiency or deficiency in coastal waters, especially, where upwelling is a regular phenomenon? Therefore, we have examined the total APA, chlorophyll a along with phosphatase producing bacteria (PPB) and related environmental parameters from nearshore to offshore in coastal waters off Trivandrum and Kochi regions differently affected by upwelling during the onset of monsoon. Off Trivandrum, APA in the offshore waters of 5-m layer at 2.23 μM P h- 1 was > 4 times higher than nearshore. Thus, low APA could be indicative of P sufficiency in coastal waters and higher activity suggestive of deficiency in offshore waters off Trivandrum. In contrast, there was less difference in APA between near and offshore surface waters off Kochi. Our results show that the regions differently affected by upwelling respond differently according to ambient P concentration, distance from shore or depth of water. These observations could apparently be applicable to other coastal systems as well, where gradients in upwelling and phosphate runoff have been noticed. Further studies on other transects would throw more light on the extent and direction of the relationship between APA and ambient P concentration. Such studies would help in understanding the level of control of this nutrient on the productivity of coastal waters.

C-13 dynamics in benthic algae: Effects of light, phosphorus, and biomass development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Walter; Fanta, S.E.; Roberts, Brian J

2008-07-01

We performed three experiments in indoor streams and one experiment in a natural stream to investigate the effects of growth factors on {delta}{sup 13}C levels in benthic microalgae. In the indoor streams, algae grown under conditions of high light and high phosphorus had {delta}{sup 13}C values that were 16% higher than those in algae grown under conditions of low light and low phosphorus. Light effects were much stronger than phosphorus effects. The effects of both factors increased in strength as algal biomass accrued, and by the end of the experiments, algal {delta}{sup 13}C and biomass were highly correlated. In themore » natural stream, algae exposed to direct sunlight were enriched 15% over shaded algae, corroborating the strong effect of light in the indoor streams. Growth factors such as light and nutrients probably reduce discrimination against {delta}{sup 13}C (raising {delta}{sup 13}C values) in benthic microalgae by causing CO{sub 2} depletion both within individual cells and within the assemblage matrix. However, because the most marked fractionation occurred in older and thicker assemblages, CO{sub 2} depletion within the assemblage matrix appeared to be more important than depletion within individual cells. In the absence of carbon-concentrating mechanisms, elevated {delta}{sup 13}C suggests that inorganic carbon may limit the growth of benthic algae. The extensive range of d13C values (-14{per_thousand} to -36{per_thousand}) created by light and nutrient manipulations in this study easily encompassed the mean {delta}{sup 13}C values of both C{sub 3} and C{sub 4} terrestrial plants, indicating the challenge aquatic ecologists face in identifying carbon sources for higher trophic levels when light and nutrient conditions vary.« less

Interactive Effect of UVR and Phosphorus on the Coastal Phytoplankton Community of the Western Mediterranean Sea: Unravelling Eco-Physiological Mechanisms.

PubMed

Carrillo, Presentación; Medina-Sánchez, Juan M; Herrera, Guillermo; Durán, Cristina; Segovia, María; Cortés, Dolores; Salles, Soluna; Korbee, Nathalie; Figueroa, Félix L; Mercado, Jesús M

2015-01-01

Some of the most important effects of global change on coastal marine systems include increasing nutrient inputs and higher levels of ultraviolet radiation (UVR, 280-400 nm), which could affect primary producers, a key trophic link to the functioning of marine food webs. However, interactive effects of both factors on the phytoplankton community have not been assessed for the Mediterranean Sea. An in situ factorial experiment, with two levels of ultraviolet solar radiation (UVR+PAR vs. PAR) and nutrients (control vs. P-enriched), was performed to evaluate single and UVR×P effects on metabolic, enzymatic, stoichiometric and structural phytoplanktonic variables. While most phytoplankton variables were not affected by UVR, dissolved phosphatase (APAEX) and algal P content increased in the presence of UVR, which was interpreted as an acclimation mechanism of algae to oligotrophic marine waters. Synergistic UVR×P interactive effects were positive on photosynthetic variables (i.e., maximal electron transport rate, ETRmax), but negative on primary production and phytoplankton biomass because the pulse of P unmasked the inhibitory effect of UVR. This unmasking effect might be related to greater photodamage caused by an excess of electron flux after a P pulse (higher ETRmax) without an efficient release of carbon as the mechanism to dissipate the reducing power of photosynthetic electron transport.

Nutrition versus defense: Why Myzus persicae (green peach aphid) prefers and performs better on young leaves of cabbage

PubMed Central

Cao, He-He; Zhang, Zhan-Feng; Wang, Xiao-Feng

2018-01-01

Plant leaves of different ages differ in nutrients and toxic metabolites and thus exhibit various resistance levels against insect herbivores. However, little is known about the influence of leaf ontogeny on plant resistance to phloem-feeding insects. In this study, we found that the green peach aphid, Myzus persicae, preferred to settle on young cabbage leaves compared with mature or old leaves, although young leaves contained the highest concentration of glucosinolates. Furthermore, aphids feeding on young leaves had higher levels of glucosinolates in their body, but aphids performed better on young leaves in terms of body weight and population growth. Phloem sap of young leaves had higher amino acid:sugar molar ratio than mature leaves, and aphids feeding on young leaves showed two times longer phloem feeding time and five times more honeydew excretion than on other leaves. These results indicate that aphids acquired the highest amount of nutrients and defensive metabolites when feeding on young cabbage leaves that are strong natural plant sinks. Accordingly, we propose that aphids generally prefer to obtain more nutrition rather than avoiding host plant defense, and total amount of nutrition that aphids could obtain is significantly influenced by leaf ontogeny or source-sink status of feeding sites. PMID:29684073

A gradient of nutrient enrichment reveals nonlinear impacts of fertilization on Arctic plant diversity and ecosystem function.

PubMed

Prager, Case M; Naeem, Shahid; Boelman, Natalie T; Eitel, Jan U H; Greaves, Heather E; Heskel, Mary A; Magney, Troy S; Menge, Duncan N L; Vierling, Lee A; Griffin, Kevin L

2017-04-01

Rapid environmental change at high latitudes is predicted to greatly alter the diversity, structure, and function of plant communities, resulting in changes in the pools and fluxes of nutrients. In Arctic tundra, increased nitrogen (N) and phosphorus (P) availability accompanying warming is known to impact plant diversity and ecosystem function; however, to date, most studies examining Arctic nutrient enrichment focus on the impact of relatively large (>25x estimated naturally occurring N enrichment) doses of nutrients on plant community composition and net primary productivity. To understand the impacts of Arctic nutrient enrichment, we examined plant community composition and the capacity for ecosystem function (net ecosystem exchange, ecosystem respiration, and gross primary production) across a gradient of experimental N and P addition expected to more closely approximate warming-induced fertilization. In addition, we compared our measured ecosystem CO 2 flux data to a widely used Arctic ecosystem exchange model to investigate the ability to predict the capacity for CO 2 exchange with nutrient addition. We observed declines in abundance-weighted plant diversity at low levels of nutrient enrichment, but species richness and the capacity for ecosystem carbon uptake did not change until the highest level of fertilization. When we compared our measured data to the model, we found that the model explained roughly 30%-50% of the variance in the observed data, depending on the flux variable, and the relationship weakened at high levels of enrichment. Our results suggest that while a relatively small amount of nutrient enrichment impacts plant diversity, only relatively large levels of fertilization-over an order of magnitude or more than warming-induced rates-significantly alter the capacity for tundra CO 2 exchange. Overall, our findings highlight the value of measuring and modeling the impacts of a nutrient enrichment gradient, as warming-related nutrient availability may impact ecosystems differently than single-level fertilization experiments.

Nutrient Sensing Systems in Fish: Impact on Food Intake Regulation and Energy Homeostasis

PubMed Central

Conde-Sieira, Marta; Soengas, José L.

2017-01-01

Evidence obtained in recent years in a few species, especially rainbow trout, supports the presence in fish of nutrient sensing mechanisms. Glucosensing capacity is present in central (hypothalamus and hindbrain) and peripheral [liver, Brockmann bodies (BB, main accumulation of pancreatic endocrine cells in several fish species), and intestine] locations whereas fatty acid sensors seem to be present in hypothalamus, liver and BB. Glucose and fatty acid sensing capacities relate to food intake regulation and metabolism in fish. Hypothalamus is as a signaling integratory center in a way that detection of increased levels of nutrients result in food intake inhibition through changes in the expression of anorexigenic and orexigenic neuropeptides. Moreover, central nutrient sensing modulates functions in the periphery since they elicit changes in hepatic metabolism as well as in hormone secretion to counter-regulate changes in nutrient levels detected in the CNS. At peripheral level, the direct nutrient detection in liver has a crucial role in homeostatic control of glucose and fatty acid whereas in BB and intestine nutrient sensing is probably involved in regulation of hormone secretion from endocrine cells. PMID:28111540

Nutrient balances as indicators for sustainability of broiler production systems.

PubMed

Kratz, S; Halle, I; Rogasik, J; Schnug, E

2004-04-01

1. Flock balances of nitrogen, phosphorus, zinc and copper (N, P, Zn, Cu) were calculated in order to evaluate environmental effects of three different broiler production systems (intensive indoor, free range and organic). 2. Nutrient gain in birds per unit nutrient intake (retention) in intensive indoor production was higher than in free range and organic production. 3. Nutrient surplus relative to nutrient retention was higher in organic production than in free range and intensive indoor production. 4. The main reasons for differences in nutrient efficiency between intensive indoor, free range and organic production were duration of growth period, strain of broilers and feeding strategy. 5. The calculation of whole farm indicators (livestock density, N and P excretions per hectare of farmland) demonstrates how defining system boundaries affects the outcome of an evaluation: organic farms had the smallest livestock densities and the lowest N and P excretions per hectare of farmland. 6. In the efforts to reach a more holistic evaluation of agricultural production systems, the definition of adequate system boundaries must be discussed. In addition to nutrient balances, further indicators of sustainability, such as human and ecological toxicity, should be considered.

[Nutrient distribution and its relationship with occurrence of red tide in coastal area of East China Sea].

PubMed

Han, Xiurong; Wang, Xiulin; Sun, Xia; Shi, Xiaoyong; Zhu, Chenjian; Zhang, Chuansong; Lu, Rong

2003-07-01

Nutrient (NO3(-)-N, PO4(3-)-P, Sio3(2-)-Si, NH4(+)-N, etc.) concentrations in coastal area of East China Sea were measured during April 25 to May 2, 2002, and the relationship between the spatial distribution of the nutrients and the red tide occurrence in the studied area was analyzed. The results showed that compared to the 1st class seawater quality of the national standard, the concentrations of dissolved inorganic nitrogen (DIN) and PO4(-)-P were 46% and 60% higher, respectively, showing that the studied area, especially the Changjiang River estuary and the Hangzhou Bay, was at a disadvantage of eutrophication. Furthermore, the nutrient concentrations inshore were much higher than those offshore, and the isolines nearly paralleled with the coastline, meaning that the nutrient distributions were mainly influenced by terrestrial discharges. It also showed that the relatively high concentrations of nutrients, especially DIN and PO4(3-)-P, might result in the red-tide occurrence. However, the red tide did not occur in the area with the highest concentrations of the nutrients, further demonstrating that the eutrophication was not the unique environmental factor inducing red-tide occurrence.

Assessment of factors limiting algal growth in acidic pit lakes--a case study from Western Australia, Australia.

PubMed

Kumar, R Naresh; McCullough, Clint D; Lund, Mark A; Larranaga, Santiago A

2016-03-01

Open-cut mining operations can form pit lakes on mine closure. These new water bodies typically have low nutrient concentrations and may have acidic and metal-contaminated waters from acid mine drainage (AMD) causing low algal biomass and algal biodiversity. A preliminary study was carried out on an acidic coal pit lake, Lake Kepwari, in Western Australia to determine which factors limited algal biomass. Water quality was monitored to obtain baseline data. pH ranged between 3.7 and 4.1, and solute concentrations were slightly elevated to levels of brackish water. Concentrations of N were highly relative to natural lakes, although concentrations of FRP (<0.01 mg/L) and C (total C 0.7-3.7 and DOC 0.7-3.5 mg/L) were very low, and as a result, algal growth was also extremely low. Microcosm experiment was conducted to test the hypothesis that nutrient enrichment will be able to stimulate algal growth regardless of water quality. Microcosms of Lake Kepwari water were amended with N, P and C nutrients with and without sediment. Nutrient amendments under microcosm conditions could not show any significant phytoplankton growth but was able to promote benthic algal growth. P amendments without sediment showed a statistically higher mean algal biomass concentration than controls or microcosms amended with phosphorus but with sediment did. Results indicated that algal biomass in acidic pit lake (Lake Kepwari) may be limited primarily by low nutrient concentrations (especially phosphorus) and not by low pH or elevated metal concentrations. Furthermore, sediment processes may also reduce the nutrient availability.

Tide- and rainfall-induced variations of physical and chemical parameters in a mangrove-depleted estuary of East Hainan (South China Sea).

PubMed

Krumme, Uwe; Herbeck, Lucia S; Wang, Tianci

2012-12-01

The estuarine dynamics favoring the coexistence of mangroves, seagrass and corals at small river mouths are often poorly understood. We characterize the tidal, day/night and rainfall-induced short-term dynamics in salinity, pH, dissolved oxygen (DO), chlorophyll a (chl a), total suspended matter (TSM), water transparency, surface currents and dissolved nutrients (NO(x)(-), NH(4)(+), PO(4)(3)(-), Si(OH)(4)) of the Wenchang/Wenjiao Estuary (East Hainan, tropical China). Samples were taken at three fixed sites along the estuary during 24 h spring tide cycles in different seasons. Salinity, DO, water transparency and pH generally increased seawards while nutrients decreased. All parameters varied with the tidal cycle, partially in interaction with the diel cycle. Nutrients, chl a and TSM usually fluctuated inversely with water level. Stratification was strong. Inflowing bottom water was of higher salinity, DO and pH and lower temperature and nutrient concentrations than the surface water. Tidal mixing provided regular ventilation of the estuary and limited eutrophication effects of nutrients from aquaculture, agriculture and urban effluents. Under dry weather conditions, the brackish-water lagoon functioned as a sink of nutrients due to efficient uptake by phytoplankton. Presently, the runoff from common intense rains in the watershed affects the estuary with little time delay due to terrestrial deforestation, channelization and loss of mangrove area. The frequency, strength and duration of intermittent estuarization of the back-reef areas have likely increased in the past and deteriorate present seagrass and coral health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes

NASA Technical Reports Server (NTRS)

Cao, W.; Tibbitts, T. W.

1991-01-01

This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations.

Organic Wheat Farming Improves Grain Zinc Concentration

PubMed Central

Helfenstein, Julian; Müller, Isabel; Grüter, Roman; Bhullar, Gurbir; Mandloi, Lokendra; Papritz, Andreas; Siegrist, Michael; Schulin, Rainer; Frossard, Emmanuel

2016-01-01

Zinc (Zn) nutrition is of key relevance in India, as a large fraction of the population suffers from Zn malnutrition and many soils contain little plant available Zn. In this study we compared organic and conventional wheat cropping systems with respect to DTPA (diethylene triamine pentaacetic acid)-extractable Zn as a proxy for plant available Zn, yield, and grain Zn concentration. We analyzed soil and wheat grain samples from 30 organic and 30 conventional farms in Madhya Pradesh (central India), and conducted farmer interviews to elucidate sociological and management variables. Total and DTPA-extractable soil Zn concentrations and grain yield (3400 kg ha-1) did not differ between the two farming systems, but with 32 and 28 mg kg-1 respectively, grain Zn concentrations were higher on organic than conventional farms (t = -2.2, p = 0.03). Furthermore, multiple linear regression analyses revealed that (a) total soil zinc and sulfur concentrations were the best predictors of DTPA-extractable soil Zn, (b) Olsen phosphate taken as a proxy for available soil phosphorus, exchangeable soil potassium, harvest date, training of farmers in nutrient management, and soil silt content were the best predictors of yield, and (c) yield, Olsen phosphate, grain nitrogen, farmyard manure availability, and the type of cropping system were the best predictors of grain Zn concentration. Results suggested that organic wheat contained more Zn despite same yield level due to higher nutrient efficiency. Higher nutrient efficiency was also seen in organic wheat for P, N and S. The study thus suggests that appropriate farm management can lead to competitive yield and improved Zn concentration in wheat grains on organic farms. PMID:27537548

Organic Wheat Farming Improves Grain Zinc Concentration.

PubMed

Helfenstein, Julian; Müller, Isabel; Grüter, Roman; Bhullar, Gurbir; Mandloi, Lokendra; Papritz, Andreas; Siegrist, Michael; Schulin, Rainer; Frossard, Emmanuel

2016-01-01

Zinc (Zn) nutrition is of key relevance in India, as a large fraction of the population suffers from Zn malnutrition and many soils contain little plant available Zn. In this study we compared organic and conventional wheat cropping systems with respect to DTPA (diethylene triamine pentaacetic acid)-extractable Zn as a proxy for plant available Zn, yield, and grain Zn concentration. We analyzed soil and wheat grain samples from 30 organic and 30 conventional farms in Madhya Pradesh (central India), and conducted farmer interviews to elucidate sociological and management variables. Total and DTPA-extractable soil Zn concentrations and grain yield (3400 kg ha-1) did not differ between the two farming systems, but with 32 and 28 mg kg-1 respectively, grain Zn concentrations were higher on organic than conventional farms (t = -2.2, p = 0.03). Furthermore, multiple linear regression analyses revealed that (a) total soil zinc and sulfur concentrations were the best predictors of DTPA-extractable soil Zn, (b) Olsen phosphate taken as a proxy for available soil phosphorus, exchangeable soil potassium, harvest date, training of farmers in nutrient management, and soil silt content were the best predictors of yield, and (c) yield, Olsen phosphate, grain nitrogen, farmyard manure availability, and the type of cropping system were the best predictors of grain Zn concentration. Results suggested that organic wheat contained more Zn despite same yield level due to higher nutrient efficiency. Higher nutrient efficiency was also seen in organic wheat for P, N and S. The study thus suggests that appropriate farm management can lead to competitive yield and improved Zn concentration in wheat grains on organic farms.

Inverse relationship between fat intake and blood lead levels in the Korean adult population in the KNHANES 2007-2009.

PubMed

Park, Sunmin; Lee, Byung-Kook

2012-07-15

Blood lead levels (BLLs) in the Korean adult population are about twofold higher than those in the US adult population, which may be related to nutrient intake. We examined which nutritional factors might be associated with decreased BLL. This study was based on Korean National Health and Nutrition Examination Survey data obtained over 3 years (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, probability-cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. A multiple regression analysis after controlling for covariates indicated that dietary fat and protein were significant opposite predictors of BLL in five different models; fat and protein intake had negative and positive associations with BLL, respectively. Covariates used in the analysis were sex, age, regional area, education level, smoking and drinking status, hypertension, use of antihypertensive drugs, diabetes, use of antidiabetic drugs, use of cholesterol-lowering drugs, hemoglobin level, and exposure to chemical substances during daily life. Intake levels of other nutrients, such as dietary fiber, carbohydrates, and calcium, did not show any significant effect on BLL. Gender was also an important predictor: BLL was significantly higher in men than women. However, total femur T-score, which represents bone mass, was unaffected by BLL. When calculating adjusted predicted marginal values of blood lead according to dietary fat percentage, BLL was lower by 5.3% and 8.0% in men when fat intake was increased from 10% to 20% and 25%, respectively. This effect of fat intake on BLL was minimal in women. The accumulation of body stores of lead from lead exposure may be reduced by increasing dietary fat consumption to 25% of energy intake, especially in men. However, this must be weighed against possible cardiovascular risks of higher fat diets. Copyright © 2012 Elsevier B.V. All rights reserved.

Temporal-spatial dynamics in orthoptera in relation to nutrient availability and plant species richness.

PubMed

Hendriks, Rob J J; Carvalheiro, Luisa G; Kleukers, Roy M J C; Biesmeijer, Jacobus C

2013-01-01

Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets), a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability) could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs) or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen deposition on higher trophic levels it is essential to take into account species life-history traits.

Microbial limitation in a changing world: A stoichiometric approach for predicting microbial resource limitation and fluxes

NASA Astrophysics Data System (ADS)

Midgley, M.; Phillips, R.

2014-12-01

Microbes mediate fluxes of carbon (C), nitrogen (N), and phosphorus (P) in soils depending on ratios of available C, N, and P relative to microbial demand. Hence, characterizing microbial C and nutrient limitation in soils is critical for predicting how ecosystems will respond to human alterations of climate and nutrient availability. Here, we take a stoichiometric approach to assessing microbial C, N, and P limitation by using threshold element ratios (TERs). TERs enable shifting resource limitation to be assessed by matching C, N and P ratios from microbial biomass, extracellular enzyme activities, and soil nutrient concentrations. We assessed microbial nutrient limitation in temperate forests dominated by trees that associate with one of two mycorrhizal symbionts: arbsucular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. We found that both ECM and AM microbial communities were co-limited by C and N, supporting conventional wisdom that microbes are C-limited and temperate forests are N-limited. However, AM microbial communities were relatively more C-limited than ECM communities (P=0.001). In response to chronic field N fertilization, both AM and ECM communities became relatively more P-limited (P=0.011), but they remained N- and C-limited overall. Thus, realistic levels of N deposition may not dampen microbial N limitation. Reflecting differences in relative limitation, N mineralization rates were higher in AM soils than in ECM soils (P=0.004) while C mineralization rates were higher in ECM soils than in AM soils (P=0.023). There were no significant differences in P flux between AM and ECM soils or detectable mineralization responses to N addition, indicating that mineralization rates are closely tied to C and nutrient limitation. Overall, we found that 1) microbial resource limitation can be detected without resource addition; and 2) TERs and ratios of labile resources are viable tools for predicting mineralization responses to resource additions.

Effect of climate change and mollusc invasion on eutrophication and algae blooms in the lagoon ecosystems of the Baltic Sea

NASA Astrophysics Data System (ADS)

Aleksandrov, Sergei; Gorbunova, Julia; Rudinskaya, Lilia

2015-04-01

Coastal lagoons are most vulnerable to impacts of natural environmental and anthropogenic factors. The Curonian Lagoon and Vistula Lagoon are the largest coastal lagoons of the Baltic Sea, relating to the most highly productive water bodies of Europe. The Curonian Lagoon is choke mostly freshwater lagoon, while the Vistula Lagoon is restricted brackish water lagoon. In the last decades the nutrients loading changes, warming trend and biological invasions are observed. The researches (chlorophyll, primary production, nutrients, phytoplankton, benthos, etc) were carried out monthly since 1991 to 2014. The database includes 1600 stations in the Curonian Lagoon, 1650 stations in the Vistula Lagoon. Eutrophication and algae blooms are most important problems. Multiple reductions of nutrients loading from the watershed area in 1990s did not result in considerable improvement of the ecological situation in the lagoons. The Curonian Lagoon may be characterized as hypertrophic water body with "poor" water quality. Climate change in 1990s-2000s combined with other factors (freshwater, slow-flow exchange, high nutrients concentrations) creates conditions for Cyanobacteria "hyperblooms". Hyperbloom of Cyanophyta (average for the growing season Chl > 100 μg/l) were observed during 4 years in 1990s and 7 years in 2000s. The summer water temperature is the key environmental factor determining the seasonal and long-term variability of the primary production and algae blooms. Mean annual primary production in 2010-2014 (600 gC·m-2·year-1) is considerable higher, than in the middle of 1970s (300 gC·m-2·year-1). The local climate warming in the Baltic region caused ongoing eutrophication and harmful algae blooms in the Curonian Lagoon despite of significant reduction of nutrients loading in 1990s-2000s. Harmful algal blooms in July-October (chlorophyll to 700-3400 μg/l) result in deterioration of the water chemical parameters, death of fish in the coastal zone and pollution with toxins, symptoms of exposure are observed at different trophic levels (zooplankton, fish). "Hyperblooms" of Cyanobacteria is the most dangerous for coastal towns (Polessk, Zelenogradsk) and tourist resorts (UNESCO National Park "Curonian Spit"). Also, unfavorable effects of eutrophication have been observed in restricted Vistula Lagoon. Mean annual temperature increased by 1.4°С for 40 years, and water warming combined with other factors created conditions for phytoplankton "hyperblooms" (70-80 μg Chl/l) in 1995-2010. Mean annual primary production in 2000s (430 gC·m-2·year-1) is considerable higher, than in the middle of 1970s (300 gC·m-2·year-1). The climate warming was cause ongoing eutrophication and harmful algal blooms in summer in 1990-2010 despite of significant reduction of nutrients loading in the lagoon. After the invasion of the North American filter-feeding bivalve Rangia cuneata the benthic biomass increased by 8 times (360 g/m2), and chlorophyll decreased by 3.5 times (10 μg/l) in 2011. Water quality is significantly improved from "poor" to "satisfactory" level in 2011-2014, e.g., transparency increased by 2 times. The phytoplankton assimilation numbers increased to maximum (300-400 mgC·mgChl-1·day-1), which are discover in aquatic ecosystems, and primary production remained at previous level. Therefore mollusc invasion improved water quality, but Vistula lagoon ecosystem remained at eutrophic-hypertrophic level. This allowed the function to other trophic groups (zooplankton, fish) at a stable long-term level.

Relation of Urinary Calcium and Magnesium Excretion to Blood Pressure

PubMed Central

Kesteloot†, Hugo; Tzoulaki, Ioanna; Brown, Ian J.; Chan, Queenie; Wijeyesekera, Anisha; Ueshima, Hirotsugu; Zhao, Liancheng; Dyer, Alan R.; Unwin, Robert J.; Stamler, Jeremiah; Elliott, Paul

2011-01-01

Data indicate an inverse association between dietary calcium and magnesium intakes and blood pressure (BP); however, much less is known about associations between urinary calcium and magnesium excretion and BP in general populations. The authors assessed the relation of BP to 24-hour excretion of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40–59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) comprised 10,067 persons aged 20–59 years from 52 samples around the world. Timed 24-hour urine collections, BP measurements, and nutrient data from four 24-hour dietary recalls (INTERMAP) were collected. In multiple linear regression analyses, urinary calcium excretion was directly associated with BP. After adjustment for multiple confounders (including weight, height, alcohol intake, calcium intake, urinary sodium level, and urinary potassium intake), systolic BP was 1.9 mm Hg higher per each 4.1 mmol per 24 hours (2 standard deviations) of higher urinary calcium excretion (associations were smaller for diastolic BP) in INTERMAP. Qualitatively similar associations were observed in INTERSALT analyses. Associations between magnesium excretion and BP were small and nonsignificant for most of the models examined. The present data suggest that altered calcium homoeostasis, as exhibited by increased calcium excretion, is associated with higher BP levels. PMID:21624957

A new insight into root responses to external cues: Paradigm shift in nutrient sensing

PubMed Central

Bhardwaj, Deepak; Medici, Anna; Gojon, Alain; Lacombe, Benoît; Tuteja, Narendra

2015-01-01

Higher plants are sessile and their growth relies on nutrients present in the soil. The acquisition of nutrients is challenging for plants. Phosphate and nitrate sensing and signaling cascades play significant role during adverse conditions of nutrient unavailability. Therefore, it is important to dissect the mechanism by which plant roots acquire nutrients from the soil. Root system architecture (RSA) exhibits extensive developmental flexibility and changes during nutrient stress conditions. Growth of root system in response to external concentration of nutrients is a joint operation of sensor or receptor proteins along with several other cytoplasmic accessory proteins. After nutrient sensing, sensor proteins start the cellular relay involving transcription factors, kinases, ubiquitin ligases and miRNA. The complexity of nutrient sensing is still nebulous and many new players need to be better studied. This review presents a survey of recent paradigm shift in the advancements in nutrient sensing in relation to plant roots. PMID:26146897

Assessment of nutrient supplement to reduce gentamicin-induced ototoxicity.

PubMed

Le Prell, C G; Ojano-Dirain, C; Rudnick, E W; Nelson, M A; DeRemer, S J; Prieskorn, D M; Miller, J M

2014-06-01

Gentamicin is an aminoglycoside antibiotic used to treat gram-negative bacterial infections. Treatment with this antibiotic carries the potential for adverse side effects, including ototoxicity and nephrotoxicity. Ototoxic effects are at least in part a consequence of oxidative stress, and various antioxidants have been used to attenuate gentamicin-induced hair cell death and hearing loss. Here, a combination of nutrients previously shown to reduce oxidative stress in the hair cells and attenuate hearing loss after other insults was evaluated for potential protection against gentamicin-induced ototoxicity. Guinea pigs were maintained on a nutritionally complete standard laboratory animal diet or a diet supplemented with β-carotene, vitamins C and E, and magnesium. Three diets with iterative increases in nutrient levels were screened; the final diet selected for study use was one that produced statistically reliable increases in plasma levels of vitamins C and E and magnesium. In two separate studies, significant decreases in gentamicin-induced hearing loss at frequencies including 12 kHz and below were observed, with less benefit at the higher frequencies. Consistent with the functional protection, robust protection of both the inner and outer hair cell populations was observed, with protection largely in the upper half of the cochlea. Protection was independently assessed in two different laboratories, using two different strains of guinea pigs. Additional in vitro tests did not reveal any decrease in antimicrobial activity with nutrient additives. Currently, there are no FDA-approved treatments for the prevention of gentamicin-induced ototoxicity. The current data provide a rationale for continued investigations regarding translation to human patients.

Arsenate exposure affects amino acids, mineral nutrient status and antioxidants in rice (Oryza sativa L.) genotypes.

PubMed

Dwivedi, S; Tripathi, R D; Tripathi, P; Kumar, A; Dave, R; Mishra, S; Singh, R; Sharma, D; Rai, U N; Chakrabarty, D; Trivedi, P K; Adhikari, B; Bag, M K; Dhankher, O P; Tuli, R

2010-12-15

Simulated pot experiments were conducted on four rice (Oryza sativa L.) genotypes (Triguna, IR-36, PNR-519, and IET-4786) to examine the effects of As(V) on amino acids and mineral nutrient status in grain along with antioxidant response to arsenic exposure. Rice genotypes responded differentially to As(V) exposure in terms of amino acids and antioxidant profiles. Total amino acid content in grains of all rice genotypes was positively correlated with arsenic accumulation. While, most of the essential amino acids increased in all cultivars except IR-36, glutamic acid and glycine increased in IET-4786 and PNR-519. The level of nonprotein thiols (NPTs) and the activities of superoxide dismutase (SOD; EC 1.15.1.1), glutathione reductase (GR; EC 1.6.4.2) and ascorbate peroxidase (APX; EC 1.11.1.11) increased in all rice cultivars except IET-4786. A significant genotypic variation was also observed in specific arsenic uptake (SAU; mg kg(-1)dw), which was in the order of Triguna (134) > IR-36 (71) > PNR-519 (53) > IET-4786 (29). Further, application of As(V) at lower doses (4 and 8 mg L(-1) As) enhanced the accumulation of selenium (Se) and other nutrients (Fe, P, Zn, and S), however, higher dose (12 mg L(-1) As) limits the nutrient uptake in rice. In conclusion, low As accumulating genotype, IET-4786, which also had significantly induced level of essential amino acids, seems suitable for cultivation in moderately As contaminated soil and would be safe for human consumption.

Holocene environmental change and development of the nutrient budget of histosols in North Iceland

NASA Astrophysics Data System (ADS)

Möckel, Susanne Claudia; Erlendsson, Egill; Gísladóttir, Guðrún

2017-04-01

Backround and aims: Little is known about vegetation changes in Icelandic peatlands in the context of soil chemical properties. By connecting soil chemical and physical characteristics with palaeobotanical data we examined interactions between climate, histosols, vegetation and land use during the Holocene. Methods: Exchangeable base cations, cation exchange capacity (CEC), base saturation (BS), and decomposition rates using carbon:nitrogen ratio (C:N) and von Post humification and soil physical properties were determined. Vegetation development was reconstructed based on pollen analysis. The impact of geographic location was examined by comparing results from three sloping fens (coastal, inland and highland fringe). Results: Minerogenic content was highest in the proximity of the active volcanic belt, reflected in higher C:N and nutrient content. The site closest to the sea revealed exceptionally high BS. C:N was either stable throughout the profile or increased with depth. Plant species richness, species evenness, and pollen concentrations were greatest at the site with lowest nutrient levels. Conclusions: Minerogenic content facilitates the ability to bind nutrients. Lower fertility levels optimize plant growth. C:N alone is not a reliable indicator of decomposition rates, but depends on the quality of the organic parent material. Environmental conditions driven by climate changes caused alterations in vegetation and soil properties before the settlement. Nevertheless, overall the histosols showed resilience towards severe degradation. After the settlement (c. AD 870), the soils struggled to buffer the impact caused by destruction of vegetation and increased erosion. This study increases our understanding of environmental and anthropogenic determinants of soil- and vegetation development.

Elymus repens biomass allocation and acquisition as affected by light and nutrient supply and companion crop competition

PubMed Central

Ringselle, Björn; Prieto-Ruiz, Inés; Andersson, Lars; Aronsson, Helena; Bergkvist, Göran

2017-01-01

Background and Aims Competitive crops are a central component of resource-efficient weed control, especially for problematic perennial weeds such as Elymus repens. Competition not only reduces total weed biomass, but denial of resources can also change the allocation pattern – potentially away from the underground storage organs that make perennial weeds difficult to control. Thus, the competition mode of crops may be an important component in the design of resource-efficient cropping systems. Our aim was to determine how competition from companion crops with different modes of competition affect E. repens biomass acquisition and allocation and discuss that in relation to how E. repens responds to different levels of light and nutrient supply. Methods Greenhouse experiments were conducted with E. repens growing in interspecific competition with increasing density of perennial ryegrass or red clover, or growing at three levels of both light and nutrient supply. Key Results Elymus repens total biomass decreased with increasing biomass of the companion crop and the rate of decrease was higher with red clover than with perennial ryegrass, particularly for E. repens rhizome biomass. A reduced nutrient supply shifted E. repens allocation towards below-ground biomass while a reduced light supply shifted it towards shoot biomass. Red clover caused no change in E. repens allocation pattern, while ryegrass mostly shifted the allocation towards below-ground biomass, but the change was not correlated with ryegrass biomass. Conclusions The companion crop mode of competition influences both the suppression rate of E. repens biomass acquisition and the likelihood of shifts in E. repens biomass allocation. PMID:28025285

Notable increases in nutrient concentrations in a shallow lake during seasonal ice growth.

PubMed

Fang, Yang; Changyou, Li; Leppäranta, Matti; Xiaonghong, Shi; Shengnan, Zhao; Chengfu, Zhang

2016-12-01

Nutrients may be eliminated from ice when liquid water is freezing, resulting in enhanced concentrations in the unfrozen water. The nutrients diluted from the ice may contribute to accumulated concentrations in sediment during winter and an increased risk of algae blooms during the following spring and summer. The objective of this study was to evaluate the influence of ice cover on nitrogen (N) and phosphorus (P) concentrations in the water and sediment of a shallow lake, through an examination of Ulansuhai Lake, northern China, from the period of open water to ice season in 2011-2013. The N and P concentrations were between two and five times higher, and between two and eight times higher, than in unfrozen lakes, respectively. As the ice thickness grew, contents of total N and total P showed C-shaped profiles in the ice, and were lower in the middle layer and higher in the bottom and surface layers. Most of the nutrients were released from the ice to liquid water. The results confirm that ice can cause the nutrient concentrations in water and sediment during winter to increase dramatically, thereby significantly impacting on processes in the water environment of shallow lakes.

Expected frontiers: Incorporating weather uncertainty into a policy analysis using an integrated bi-level multi-objective optimization framework

EPA Science Inventory

Weather is the main driver in both plant use of nutrients and fate and transport of nutrients in the environment. In previous work, we evaluated a green tax for control of agricultural nutrients in a bi-level optimization framework that linked deterministic models. In this study,...

Productivity aspects of three tropical seagrass species in areas of different nutrient levels in Kenya

NASA Astrophysics Data System (ADS)

Uku, J.; Björk, M.

2005-05-01

Previous work conducted in two seagrass areas of different nutrient status, along the Kenyan coast, has shown that the seagrasses were characterised by differences in the species composition and biomass of epiphytic algae. This study was undertaken to evaluate the productivity patterns of the seagrass species growing in these same sites. Studies were made on Thalassodendron ciliatum (Forskål) den Hartog, Thalassia hemprichii (Ehrenberg) Aschers and Cymodocea rotundata Ehrenberg and Hempr. ex Ascherson growing in the lagoons of Nyali and Vipingo, along the Kenyan coast, during the South East (SE) and North East (NE) monsoon periods. The results of this study revealed differences in the levels of nitrate within the water column, with Vipingo having lower levels of around 4 μM during the low tide period of the SE monsoon while nitrate levels in Nyali reached levels of 16 μM during the same period. Of the three seagrass species studied, C. rotundata had the highest shoot densities in both sites. The shoot densities of C. rotundata reached levels of 1300 shoots m -2 compared to an average of 600 shoots m -2 for both T. ciliatum and T. hemprichii. The stems of T. ciliatum were found to be 200 mm long in Nyali whereas those in Vipingo were 80 mm in length. Of the three seagrasses T. ciliatum and T. hemprichii showed significant differences in total leaf growth between the two sites. However, of these two species, only T. hemprichii showed distinct differences in leaf production and biomass when the two sites were compared. Leaves of T. hemprichii showed growth rates of 0.008 g dw shoot -1 day -1 in Nyali while the growth rate in Vipingo was 0.004 g dw shoot -1 day -1. Leaf production rates were approximately 0.005 g dw shoot -1 day -1 for T. ciliatum in both Nyali and Vipingo and that of C. rotundata was approximately 0.0015 g dw shoot -1 day -1 in the two sites. This suggests that of the three species studied, T. hemprichii may have been influenced by the nutrient input in Nyali. The abundance of epiphytes on the stems of T. ciliatum was higher in Nyali during both seasons; therefore we suggest that although the composition of epiphytic species is the main indicator of nutrient enrichment in these areas the enhanced productivity of T. hemprichii may be another indicator of the nutrient status of these study sites.

Evaluation of physiological, growth and yield responses of a tropical oil crop (Brassica campestris L. var. Kranti) under ambient ozone pollution at varying NPK levels.

PubMed

Singh, Poonam; Agrawal, Madhoolika; Agrawal, Shashi Bhushan

2009-03-01

A field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O(3) concentration varied from 41.65 to 54.2ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O(3).

Differences in Nutrient Intake and Biochemical Nutrient Status Between Sarcopenic and Nonsarcopenic Older Adults-Results From the Maastricht Sarcopenia Study.

PubMed

Ter Borg, Sovianne; de Groot, Lisette C P G M; Mijnarends, Donja M; de Vries, Jeanne H M; Verlaan, Sjors; Meijboom, Saskia; Luiking, Yvette C; Schols, Jos M G A

2016-05-01

There is growing evidence of a relationship between nutrients and muscle mass, strength, and physical performance. Although nutrition is seen as an important pillar of treating sarcopenia, data on the nutritional intake of sarcopenic older adults are limited. To investigate potential nutritional gaps in the sarcopenic population, the present study compared nutrient intake and biochemical nutrient status between sarcopenic and nonsarcopenic older adults. The Maastricht Sarcopenia Study included 227 community-dwelling older adults (≥65 years) from Maastricht, 53 of whom were sarcopenic based on the European Working Group on Sarcopenia in Older People algorithm. Habitual dietary intake was assessed with a food frequency questionnaire and data on dietary supplement use were collected. In addition, serum 25-hydroxyvitamin D, magnesium and α-tocopherol/cholesterol, plasma homocysteine and red blood cell n-3, and n-6 fatty acids profiles were assessed. Nutrient intake and biochemical nutrient status of the sarcopenic groups were compared with those of the nonsarcopenic groups. The robustness of these results was tested with a multiple regression analysis, taking into account between-group differences in characteristics. Sarcopenic older adults had a 10%-18% lower intake of 5 nutrients (n-3 fatty acids, vitamin B6, folic acid, vitamin E, magnesium) compared with nonsarcopenic older adults (P < .05). When taking into account dietary supplement intake, a 19% difference remained for n-3 fatty acids intake (P = .005). For the 2 biochemical status markers, linoleic acid and homocysteine, a 7% and 27% difference was observed, respectively (P < .05). The higher homocysteine level confirmed the observed lower vitamin B intake in the sarcopenic group. Observed differences in eicosapentaenoic acid and 25-hydroxyvitamin D between the groups were related to differences in age and living situation. Sarcopenic older adults differed in certain nutritional intakes and biochemical nutrient status compared with nonsarcopenic older adults. Dietary supplement intake reduced the gap for some of these nutrients. Targeted nutritional intervention may therefore improve the nutritional intake and biochemical status of sarcopenic older adults. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Effects of anthropogenic activities on chemical contamination within the Grand Canal, China.

PubMed

Wang, Xiaolong; Han, Jingyi; Xu, Ligang; Gao, Junfeng; Zhang, Qi

2011-06-01

Contamination of nutrients and heavy metals within aquatic system is of great concern due to its potential impact on human and animal health. The Grand Canal of China, the largest artificial river in the world, is of great importance in supplying water resource, transporting cargo, and recreating resident, as well as great historical heritage. This study assessed and examined the impact of human activities on characters of contamination distribution within the section of the Canal in Taihu watershed. Physicochemical parameters of surface water quality were determined monthly from the year 2004 to 2006 at 11 sites that were influenced by different anthropogenic activities along the Canal. Moreover, contaminations at surface sediments (20 cm) at the same locations were also analyzed in September 2006. Results showed that the Canal had been seriously polluted, which was characterized with high spatial variations in contaminations distribution. The sites influenced mainly by industry and urbanization showed higher contents of nutrients and lower levels of dissolve oxygen than other sites. Concentrations of nitrogen at all studied sites exceeded the worst level of surface water quality according to the National Criterion of Surface Water Quality, China, with the average values varying from 2.27 to 10.34 mg/L. Furthermore, the site influenced mainly by industry (i.e., Site 4) presented the highest contents of cadmium (3.453 mg/kg), chromium (196.87 mg/kg), nickel (87.12 mg/kg), zinc (381.8 mg/kg), and copper (357.32 mg/kg). While sites in vicinity to cities had presented relatively higher contents of metals, especially for the site located downstream of Changzhou City (Site 3) had presented the highest contents of mercury (1.64 mg/kg) and lead (197.62 mg/kg). Copper at Sites 2 to 6, Nickel at Sites 2 to 9 except for Site 7, chromium, lead, and zinc at Sites 3 to 6 had exceeded New York State Department of Environmental Conservation (NYSDEC) Severe Effect Level (SEL). By multivariate statistical, nutrient variables, companied with V-phen, had contributed the most variation of water quality, while nutrient and metals had explained the most part of total variance of contaminations in sediment. This study indicated that the canal had been polluted severely and urgently need to control.

Detecting temporal change in watershed nutrient yields

Treesearch

James D. Wickham; Timothy G. Wade; Kurt H. Riitters

2008-01-01

Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increases in watershed nutrient yields. Yet, the same meta-analyses also reveal that, absent land-...

Detecting Temporal Change in Watershed Nutrient Yields

Treesearch

James D. Wickham; Timothy G. Wade; Kurt H. Riitters

2008-01-01

Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increases in watershed nutrient yields. Yet, the same meta-analyses also reveal that, absent land-...

Effect of soil in nutrient cycle assessment at dairy farms

NASA Astrophysics Data System (ADS)

van Leeuwen, Maricke; de Boer, Imke; van Dam, Jos; van Middelaar, Corina; Stoof, Cathelijne

2016-04-01

Annual farm nutrient cycle assessments give valuable insight in the nutrient cycles and nutrient losses at dairy farms. It describes nutrient use efficiencies for the entire farm and for the underlying components cattle, manure, crops and soil. In many modelling studies, soil is kept as a constant factor, while soil quality is vital for soil functioning of the ecosystem. Improving soil quality will improve the nutrient cycle, and will also have positive effect on the soil functions crop production, water cycling and greenhouse gas mitigation. Spatial variation of soil properties within a farm, however, are not included in annual nutrient cycle assessments. Therefore it is impossible to identify fields where most profit can be gained by improving farm management at field level, and it is not possible to identify and to quantify nutrient flow path ways. The aim of this study is to develop a framework to improve the annual nutrient cycle assessment at Dutch dairy farms, by including soil properties and their spatial variation within farms. Soil type and soil quality will be described by visual soil assessment of soil quality characteristics. The visual observations will be linked to the nutrient cycle assessment, using soil-hydrological model SWAP. We will demonstrate how soil quality at field level can impact on crop production, eutrophication potential and greenhouse gas potential at farm level. Also, we will show how this framework can be used by farmers to improve their farm management. This new approach is focusing on annual nutrient cycle assessment, but could also be used in life cycle assessment. It will improve understanding of soil functioning and dairy farm management.

Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

NASA Astrophysics Data System (ADS)

Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

2013-06-01

Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006-2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43- ranged from 37 to 1063, suggesting preferential PO43- relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi) varied from 76 to 448 × 103 mol km-2 yr-1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM) and DON (up to 130 μM). Particulate phosphorus concentrations (0.5 ∼1.4 μM) were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture), as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption) in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom in the sea would be caused.

Effect of Fenton pre-oxidation on mobilization of nutrients and efficient subsequent bioremediation of crude oil-contaminated soil.

PubMed

Xu, Jinlan; Kong, Fanxing; Song, Shaohua; Cao, Qianqian; Huang, Tinglin; Cui, Yiwei

2017-08-01

Fenton pre-oxidation and a subsequent bioremediation phase of 80 days were used to investigate the importance of matching concentration of residual indigenous bacteria and nutrient levels on subsequent bioremediation of crude oil. Experiments were performed using either high (>10 7.7 ± 0.2  CFU/g soil) or low (<10 5.9 ± 0.1  CFU/g soil) concentrations of bacteria and three different nutrient levels: enough (C/N > 9.8), moderate (C/N:5-9.8), and lacking nutrient level (C/N < 5) conditions. Weak Fenton pre-oxidation (225 mM H 2 O 2 and 2.9 mM Fe 2+ ) resulted in highly matching between nutrient level and the population of residual indigenous bacteria. Up to 53% of total petroleum hydrocarbon (TPH) and 58% of main hydrocarbon (C 15 C 25 , during the first 10 days) were removed from the soil. Under matching conditions, the activity of indigenous bacteria and nutrient mobilization were enhanced, promoting the bioremediation of crude oil. In addition, the biodegradation of long chain molecules (C 26 C 30 ) required a high level of NH 4 + -N. Copyright © 2017 Elsevier Ltd. All rights reserved.

Complementary feeding recommendations based on locally available foods in Indonesia.

PubMed

Fahmida, Umi; Santika, Otte; Kolopaking, Risatianti; Ferguson, Elaine

2014-12-01

Affordable, locally contextual complementary feeding recommendations (CFRs) that take into account cultural diversity and differences in food availability will be more likely to result in long-term improvements in complementary feeding practices than general recommendations. More objective approaches, such as linear programming (LP), have been recommended to identify optimal but CFRs to meet nutrient requirements given local food availability, food patterns, food portions, and cost. To present results of our previous studies in which we developed CFRs using LP and to provide an example of how these CFRs can be put into practice in a community intervention trial in Indonesia. Dietary data were obtained using single 24-hour dietary recall or 1-day weighed diet record combined with 1-day 24-hour recall and 5-day food intake tally. With the use of the LP approach, nutrient intakes were optimized while ensuring that a realistic diet was selected by using constraints such as the diet's energy content, food patterns, food portions, and cost. The price per 100 g of edible portion was obtained from market surveys in two or three local markets in each study area. LP analysis was performed using Super Solver in MS Excel or Optifood software. Iron, zinc, calcium, and niacin were problem nutrients in all age groups of children (6 to 8, 9 to 11, and 12 to 23 months) in both rural and periurban areas, except among children of higher socioeconomic status in urban areas. Thiamin and folate were also problem nutrients found in some settings. Animal-source foods (meat, fish, poultry, and eggs [MFPE] and fortified foods were the nutrient-dense foods identified by LP to fill the nutrient gaps of these problem nutrients. Iron, calcium, zinc, niacin, and potentially folate and thiamine are typical "problem nutrients" in complementary foods of Indonesian children. However, the extent of dietary inadequacy varies across age groups, area, and socioeconomic level. MFPE and fortified foods can improve micronutrient adequacy in complementary feeding diets and should be promoted in CFRs.

Scale and legacy controls on catchment nutrient export regimes

NASA Astrophysics Data System (ADS)

Howden, N. J. K.; Burt, T.; Worrall, F.

2017-12-01

Nutrient dynamics in river catchments are complex: water and chemical fluxes are highly variable in low-order streams, but this variability declines as fluxes move through higher-order reaches. This poses a major challenge for process understanding as much effort is focussed on long-term monitoring of the main river channel (a high-order reach), and therefore the data available to support process understanding are predominantly derived from sites where much of the transient response of nutrient export is masked by the effect of averaging over both space and time. This may be further exacerbated at all scales by the accumulation of legacy nutrient sources in soils, aquifers and pore waters, where historical activities have led to nutrient accumulation where the catchment system is transport limited. Therefore it is of particular interest to investigate how the variability of nutrient export changes both with catchment scale (from low to high-order catchment streams) and with the presence of legacy sources, such that the context of infrequent monitoring on high-order streams can be better understood. This is not only a question of characterising nutrient export regimes per se, but also developing a more thorough understanding of how the concepts of scale and legacy may modify the statistical characteristics of observed responses across scales in both space and time. In this paper, we use synthetic data series and develop a model approach to consider how space and timescales combine with impacts of legacy sources to influence observed variability in catchment export. We find that: increasing space and timescales tend to reduce the observed variance in nutrient exports, due to an increase in travel times and greater mixing, and therefore averaging, of sources; increasing the influence of legacy sources inflates the variance, with the level of inflation dictated by the residence time of the respective sources.

Distribution of green algal mats throughout shallow soft bottoms of the Swedish Skagerrak archipelago in relation to nutrient sources and wave exposure

NASA Astrophysics Data System (ADS)

Pihl, Leif; Svenson, Anders; Moksnes, Per-Olav; Wennhage, Håkan

1999-06-01

Distribution and biomass of green algal mats were studied in marine shallow (0-1 m) soft-bottom areas on the Swedish west coast from 1994 to 1996, by combining aerial photography surveys with ground truth sampling. Filamentous green algae, dominated by species of the genera Cladophora and Enteromorpha, were generally present throughout the study area during July and August, and largely absent in late April and early May. These algae occurred at 60 to 90% of the locations investigated during the summer, and were estimated to cover between 30 and 50% of the total area of shallow soft bottoms of the Swedish Skagerrak archipelago. The distributional patterns were similar during the three years of the investigation and appeared unrelated to annual local nutrient inputs from point sources and river discharge. We postulate that the apparent lack of such a relationship is due to an altered state of nutrient dynamics throughout the archipelago. Mechanisms are likely to involve long-term, diffuse elevations in nutrient levels in coastal waters of the Skagerrak and the Kattegat over several decades leading to current eutrophic conditions, exceeding nutrient requirements for abundant filamentous algal growth. Patterns of algal abundance in our study were largely related to physical factors such as exposure to wind, waves and water exchange under conditions where nutrient loads among embayments seemed to be unlimited. Further, our results show that sediments covered by algal mats had higher carbon and nitrogen contents than unvegetated sediments. We hypothesise that sustained high nutrient loads, manifested in extensive biomass of filamentous algae during summer months, are re-mineralised via decay and sedimentation in the benthic realm. Hence, accumulated carbon and nutrients in the sediment could, in turn, constitute the basic pool for future algal mat production overlying soft bottoms in areas where tidal exchange is limited.

Coupling of soil respiration and nutrient mineralization: What is the role of land use?

NASA Astrophysics Data System (ADS)

Gan, Huei Ying; Schoening, Ingo; Schrumpf, Marion

2017-04-01

Microbial decomposition of soil organic matter (SOM) is coupling carbon (C) and nutrient mineralization. In order to meet their stoichiometric requirements for growth, it can be assumed that microbes have to mineralize (or remove) relative more organic carbon (OC) to acquire limiting nutrients at sites with large carbon-to-nutrient (C:N, C:P, C:S) ratios of SOM. Land use and management intensities are important controls for belowground C and nutrient availabilities, but their effect on the combined carbon and nutrient mineralization and carbon use efficiency (CUE) have rarely been addressed. The main objective of this study was to test the effect of land use (forest versus grassland), forest management (unmanaged beech forest and age-class managed coniferous and deciduous forests) and grassland management (fertilized and unfertilized meadow, mown pasture and pasture) on the stoichiometry of mineralized C, N, P and S. We incubated a total of 120 topsoil samples (0-10 cm) from three German study regions with different soil types for two weeks in microlysimeters and measured CO2 evolution and leachable organic carbon (DOC) and nutrients (NH4+, NO3-, SO42- and PO43-). The relationships between metabolic quotient (microbial respiration per unit microbial biomass; qCO2) and soil nutrient concentrations were compared between different land use and management. Preliminary results showed that qCO2 was significantly higher (p<0.001) in forests than grasslands. This supports our hypothesis that under higher nutrient limitations in forest, more energy may be allocated for maintenance than growth. In forest, qCO2 was strongly correlated to C:N ratio (r =0.84, p<0.001), while C:N was less strongly correlated with qCO2 in the grasslands (r =0.35, p>0.05). As C:N ratio was significantly higher (p<0.05) in forests (14.9±0.3) than grasslands (10.0±0.3), this finding agreed with previous studies that more C per unit microbial C is respired under lower N availability. Similary in forests, qCO2 was found to be strongly correlated to inorganic P (Olsen) content (r =0.82, p<0.001), whereas weaker correlation was observed in the grasslands (r =0.47, p>0.05). The stronger correlation in forests might indicate higher P limitation as compared to grasslands. Soil pH showed strong negative effect on qCO2 in the forests (r =-0.68, p<0.005) while positively correlated to qCO2 in the grasslands (r =0.42, p<0.05). This indicates that lower soil pH in forests results in higher qCO2 and lower CUE, but higher soil pH in the grasslands could also constrain microbial activities and result in lower CUE. Our first results suggest that qCO2 is affected by land use, and that this effect could be due to differences in nutrient availability. More analysis will follow to elucidate the interactions between qCO2 and other nutrients, and how is this affected by forest and grassland management.

Canopy Nutrient Cycling In Afromontane Tropical Forests At Different Successional Stages

NASA Astrophysics Data System (ADS)

Nyirambangutse, B.; Zibera, E.; Dusenge, M. E.; Nsabimana, D.; Pleijel, H.; Uddling, J.; Wallin, G.

2017-12-01

Canopy nutrient composition and cycling control biogeochemical processes and tree growth in forests. However, the understanding of nutrient limitations and cycling in tropical montane forests (TMF) is currently limited, in particular for Afromontane forests. In this study we investigated leaf nutrient composition and resorption, canopy nutrient cycling and soil carbon and nutrient content in 15 permanent plots at different successional stages in a TMF (elevation 1950 to 2550 m a.s.l.) in Rwanda, Central Africa. Leaf concentrations of 12 elements were analyzed in attached green leaves as well as in shed leaves of 10 early (ES) and 10 late (LS) successional tree species. Leaf nutrient concentrations mostly did not differ between ES and LS species (exception: K was 20% higher in ES), but the ratios of P, K and Mg to N were significantly higher in ES species. Mean resorption efficiencies of N (37%), P (48%) and K (46%) were much higher than for other nutrients. Nutrient resorption efficiency exhibited very large interspecific variation, did not differ between ES and LS species, and was not related to the leaf concentration of the respective element. Total leaf litterfall was on average 4.9 t ha-1 yr-1 (66% of total litterfall) and was independent of the successional stage of the forest. The total content of C, N, P and K in leaf litterfall did not differ between ES and LS stands. Ground litter turnover rates of C and N were 0.98 and 0.78 y-1, respectively. High leaf N concentrations, intermediate N:P ratios and low resorption efficiencies compared to values reported for other TMFs indicate high fertility and likely co-limitation by N and P, however progressively increasing towards P limitation during the course of succession. Our results further demonstrate that resorption efficiency and canopy litterfall inputs to soil mostly do not differ between ES and LS species in Afromontane tropical forests.

Effects of mountain agriculture on nutrient cycling at upstream watersheds

NASA Astrophysics Data System (ADS)

Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

2015-05-01

The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities, especially excessive fertilization, on ecosystem nutrient cycling at mountain watersheds.

Neuronal Calcium Signaling in Metabolic Regulation and Adaptation to Nutrient Stress.

PubMed

Jayakumar, Siddharth; Hasan, Gaiti

2018-01-01

All organisms can respond physiologically and behaviorally to environmental fluxes in nutrient levels. Different nutrient sensing pathways exist for specific metabolites, and their inputs ultimately define appropriate nutrient uptake and metabolic homeostasis. Nutrient sensing mechanisms at the cellular level require pathways such as insulin and target of rapamycin (TOR) signaling that integrates information from different organ systems like the fat body and the gut. Such integration is essential for coordinating growth with development. Here we review the role of a newly identified set of integrative interneurons and the role of intracellular calcium signaling within these neurons, in regulating nutrient sensing under conditions of nutrient stress. A comparison of the identified Drosophila circuit and cellular mechanisms employed in this circuit, with vertebrate systems, suggests that the identified cell signaling mechanisms may be conserved for neural circuit function related to nutrient sensing by central neurons. The ideas proposed are potentially relevant for understanding the molecular basis of metabolic disorders, because these are frequently linked to nutritional stress.

Methods for simulating nutritional requirement and response studies with all organisms to increase research efficiency.

PubMed

Vedenov, Dmitry; Alhotan, Rashed A; Wang, Runlian; Pesti, Gene M

2017-02-01

Nutritional requirements and responses of all organisms are estimated using various models representing the response to different dietary levels of the nutrient in question. To help nutritionists design experiments for estimating responses and requirements, we developed a simulation workbook using Microsoft Excel. The objective of the present study was to demonstrate the influence of different numbers of nutrient levels, ranges of nutrient levels and replications per nutrient level on the estimates of requirements based on common nutritional response models. The user provides estimates of the shape of the response curve, requirements and other parameters and observation to observation variation. The Excel workbook then produces 1-1000 randomly simulated responses based on the given response curve and estimates the standard errors of the requirement (and other parameters) from different models as an indication of the expected power of the experiment. Interpretations are based on the assumption that the smaller the standard error of the requirement, the more powerful the experiment. The user can see the potential effects of using one or more subjects, different nutrient levels, etc., on the expected outcome of future experiments. From a theoretical perspective, each organism should have some enzyme-catalysed reaction whose rate is limited by the availability of some limiting nutrient. The response to the limiting nutrient should therefore be similar to enzyme kinetics. In conclusion, the workbook eliminates some of the guesswork involved in designing experiments and determining the minimum number of subjects needed to achieve desired outcomes.

Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage.

PubMed

Gratieri, Luiz Augusto; Cecílio Filho, Arthur Bernardes; Barbosa, José Carlos; Pavani, Luiz Carlos

2013-01-01

With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The "Bonus no. 2" was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L(-1)) and four K concentrations (4, 6, 8, and 10 mmol L(-1)). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO₃ and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L(-1)) and K (10 mmol L(-1)) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm(-2)).

The effect of resource quantity and resource stoichiometry on microbial carbon-use-efficiency

USGS Publications Warehouse

Kleiblinger, K.M.; Hall, E.K.; Wanek, W.; Szukics, U.; Hämmerle, I.; Ellersdorfer, G.; Böck, S.; Strauss, J.; Sterflinger, K.; Richter, A.; Zechmeister-Boltenstern, S.

2010-01-01

The carbon-use-efficiency (CUE) of microorganisms is an important parameter in determining ecosystem-level carbon (C) cycling; however, little is known about how variance in resources affects microbial CUE. To elucidate how resource quantity and resource stoichiometry affect microbial CUE, we cultured four microorganisms - two fungi (Aspergillus nidulans and Trichoderma harzianum) and two bacteria (Pectobacterium carotovorum and Verrucomicrobium spinosum) - under 12 unique C, nitrogen (N) and phosphorus (P) ratios. Whereas the CUE of A. nidulans was strongly affected by C, bacterial CUE was more strongly affected by mineral nutrients (N and P). Specifically, CUE in P. carotovorum was positively correlated with P, while CUE of V. spinosum primarily depended on N. This resulted in a positive relationship between fungal CUE and resource C : nutrient stoichiometry and a negative relationship between bacterial CUE and resource C : nutrient stoichiometry. The difference in the direction of the relationship between CUE and C : nutrient for fungi vs. bacteria was consistent with differences in biomass stoichiometry and suggested that fungi have a higher C demand than bacteria. These results suggest that the links between biomass stoichiometry, resource demand and CUE may provide a mechanism for commonly observed temporal and spatial patterns in microbial community structure and function in natural habitats.

Nutrient Composition of Retail Samples of Australian Beef Sausages

PubMed Central

Cunningham, Judy; Nguyen, Van; Adorno, Paul; Droulez, Veronique

2015-01-01

Some nutrient data for beef sausages in Australia’s food composition table, NUTTAB 2010, is over 25 years old and may no longer reflect the composition of this popular food. To update this, 41 retail samples of fresh beef sausages were purchased in Melbourne, Australia, in May 2015. Each purchase was analysed, uncooked, for moisture, protein and fat. Sausages were then grouped by fat content into one of three composites and analysed for a wide range of nutrients, before and after dry heat cooking, the most popular sausage cooking method. Fat content in raw sausages averaged 14.9 g/100 g, 30% lower than NUTTAB values, varying from 7.3 to 22.6 g/100 g. This indicates it is possible to formulate leaner sausages that meet consumer expectations and may qualify for certain nutrition labelling statements. Under current Australian labelling requirements, two low fat sausages contain sufficient protein, B12, niacin, phosphorus and zinc to qualify as a good source of these nutrients and sufficient iron, selenium and vitamin A to qualify as a source of these. Sodium levels are higher than fresh beef, ranging from 680 to 840 mg/100 g. These data will be used to update NUTTAB and support product labelling and consumer education. PMID:26610557

Added sugar intake that exceeds current recommendations is associated with nutrient dilution in older Australians.

PubMed

Moshtaghian, Hanieh; Louie, Jimmy Chun Yu; Charlton, Karen E; Probst, Yasmine C; Gopinath, Bamini; Mitchell, Paul; Flood, Victoria M

2016-09-01

A nutrient dilution effect of diets high in added sugar has been reported in some older populations, but the evidence is inconsistent. The aim of this study was to investigate the association between added sugar intakes (according to recommended guidelines) and nutrient intake, food consumption, and body mass index (BMI). A cross-sectional analysis of data collected between 2007 and 2009 from participants of the Blue Mountains Eye study 4 was performed (n = 879). Dietary intake was assessed using a semiquantitative food frequency questionnaire. Added sugar content of foods was determined by applying a systematic step-wise method. BMI was calculated from measured weight and height. Food and nutrient intakes and BMI were assessed according to categories of percentage energy from added sugar (EAS% < 5%, EAS% = 5%-10%, and EAS% >10%) using analysis of covariance for multivariate analysis. Micronutrient intake including retinol equivalents, vitamins B6, B12, C, E, and D, and minerals including calcium, iron, and magnesium showed a significant inverse association with EAS% intakes (Ptrend < 0.05). In people with the lowest intake of added sugars (<5% energy) intake of alcohol, fruits, and vegetables were higher and intake of sugar sweetened beverages was lower compared to other participants (all Ptrend < 0.001). BMI was similar between the three EAS% categories. Energy intake from added sugar greater than the recommended level of 10% is associated with lower micronutrient intakes, indicating micronutrient dilution. Conversely, added sugar intakes <5% of energy intake are associated with higher micronutrient intakes. This information may inform dietary messages targeted at optimizing diet quality in older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of a nutrient-based diet quality index in UK young children and investigation into the diet quality of consumers of formula and infant foods.

PubMed

Verger, Eric O; Eussen, Simone; Holmes, Bridget A

2016-07-01

To adapt and evaluate a nutrient-based diet quality index (PANDiet) for UK young children and to determine the nutritional adequacy of their diets according to consumption of young child formula (YCF) and commercial infant foods (CIF). Content and construct validity of the PANDiet were assessed by studying associations between the PANDiet and its components, energy intake, food intakes, and child and maternal characteristics. Four groups of children were defined according to their intake of YCF and CIF: (i) no consumption; (ii) consumption of YCF; (iii) consumption of CIF; and (iv) consumption of YCF and CIF. Child and maternal characteristics, PANDiet scores and food intakes of these four groups were compared. Secondary analysis of data from the UK Diet and Nutrition Survey of Infants and Young Children (DNSIYC, 2011). Young children (n 1152) aged 12-18 months. The PANDiet was adapted to the UK based on twenty-five nutrients. A lower PANDiet score was linked to lower intakes of YCF, CIF, vegetables and fruits. Determinants of having a lower score were being older, having siblings and having a younger mother with a lower educational level. Compared with children consuming neither YCF nor CIF, PANDiet scores were higher in children consuming CIF (+1·4), children consuming YCF (+7·2) and children consuming YCF and CIF (+7·8; all P<0·001). The PANDiet is a valid indicator of the nutrient adequacy of the diet of UK young children. Consuming CIF was not found to be associated with lower nutritional adequacy whereas consuming YCF was associated with higher nutritional adequacy.

Milk consumption and the prepubertal somatotropic axis.

PubMed

Rich-Edwards, Janet W; Ganmaa, Davaasambuu; Pollak, Michael N; Nakamoto, Erika K; Kleinman, Ken; Tserendolgor, Uush; Willett, Walter C; Frazier, A Lindsay

2007-09-27

Nutrients, hormones and growth factors in dairy foods may stimulate growth hormone (GH), insulin-like growth factor I (IGF-I), and raise the ratio of IGF-I to its binding protein, IGFBP-3. We conducted pilot studies in Mongolia and Massachusetts to test the extent to which milk intake raised somatotropic hormone concentrations in prepubertal children. In Ulaanbaatar, we compared plasma levels before and after introducing 710 ml daily whole milk for a month among 46 10-11 year old schoolchildren. In a randomized cross-over study in Boston, we compared plasma hormone levels of 28 6-8 year old girls after one week of drinking 710 ml low fat (2%) milk with their hormone levels after one week of consuming a macronutrient substitute for milk. After a month of drinking whole milk, Mongolian children had higher mean plasma levels of IGF-I (p < 0.0001), IGF-I/IGFBP-3 (p < 0.0001), and 75th percentile of GH levels (p = 0.005). After a week of drinking low fat milk, Boston girls had small and non-significant increases in IGF-1, IGF-1/IGFBP-3 and GH. Milk drinking may cause increases in somatotropic hormone levels of prepubertal girls and boys. The finding that milk intake may raise GH levels is novel, and suggests that nutrients or bioactive factors in milk may stimulate endogenous GH production.

Higher water temperature enhances dietary carbohydrate utilization and growth performance in Labeo rohita (Hamilton) fingerlings.

PubMed

Alexander, C; Sahu, N P; Pal, A K; Akhtar, M S; Saravanan, S; Xavier, B; Munilkumar, S

2011-10-01

A 60-day experiment was conducted to delineate the effect of three dietary levels of gelatinized carbohydrate (GC) on growth, nutrient-utilization and body composition of Labeo rohita fingerlings (avg. wt 6.5 ± 0.3 g) reared at two water temperatures (ambient-AT (26 ± 0.8 °C) and 32 °C). Two hundred and sixteen fingerlings were randomly distributed into six treatments in triplicates. Three semi-purified isonitrogenous diets were prepared with graded levels of GC viz. D(1) : 40%, D(2) : 50% and D(3) : 58%. Growth rate, feed efficiency and protein efficiency ratio were significantly (p < 0.05) higher in 50% GC and 32 °C reared groups than their AT counterparts. Hepato Somatic Index was higher in AT reared groups compared to 32 °C reared counterparts. Apparent digestibility co-efficient of carbohydrate was significantly (p < 0.05) higher at 32 °C reared groups but decreased with increasing carbohydrate (GC) levels. Fish reared at 32 °C showed significantly (p < 0.05) higher amylase, protease and hexokinase activities while glucose-6-phosphate dehydrogenase and glucose-6-phosphatse were significantly (p < 0.05) higher at ambient temperatures. The results obtained in present study indicated that L. rohita could utilize higher level (50%) of dietary carbohydrate at 32 °C. © 2010 Blackwell Verlag GmbH.

Organic Biochar Based Fertilization

NASA Astrophysics Data System (ADS)

Schmidt, Hans-Peter; Pandit, Bishnu Hari; Cornelissen, Gerard; Kammann, Claudia

2017-04-01

Biochar produced in cost-efficient flame curtain kilns (Kon-Tiki) was nutrient enriched either with cow urine or with dissolved mineral (NPK) fertilizer to produce biochar-based fertilizers containing between 60-100 kg N, 5-60 kg P2O5 and 60-100 kg K2O, respectively, per ton of biochar. In 21 field trials nutrient-enriched biochars were applied at rates of 0.5 to 2 t ha-1 into the root zone of 13 different annual and perennial crops. Treatments combining biochar, compost and organic or chemical fertilizer were evaluated; control treatments contained the same amounts of nutrients but without biochar. All nutrient-enriched biochar substrates improved yields compared to their respective no-biochar controls. Biochar enriched with dissolved NPK produced on average 20% ± 5.1% (N=4) higher yields than standard NPK fertilization without biochar. Cow urine-enriched biochar blended with compost resulted on average in 123% ± 76.7% (N=13) higher yields compared to the organic farmer practice with cow urine-blended compost and outcompeted NPK-enriched biochar (same nutrient dose) by 103% ± 12.4% (N=4) on average. 21 field trials robustly revealed that low-dosage root zone application of organic biochar-based fertilizers caused substantial yield increases in rather fertile silt loam soils compared to traditional organic fertilization and to mineral NPK- or NPK-biochar fertilization. This can likely be explained by the nutrient carrier effect of biochar causing a slow nutrient release behavior, more balanced nutrient fluxes and reduced nutrient losses especially when liquid organic nutrients are used for the biochar enrichment. The results promise new pathways for optimizing organic farming and improving on-farm nutrient cycling.

21 CFR 101.54 - Nutrient content claims for “good source,” “high,” “more,” and “high potency.”

Code of Federal Regulations, 2011 CFR

2011-04-01

... antioxidant activity; that is, when there exists scientific evidence that, following absorption from the... of the nutrients with recognized antioxidant activity. The list of nutrients shall appear in letters... the term “antioxidant.” A nutrient content claim that characterizes the level of antioxidant nutrients...

21 CFR 101.54 - Nutrient content claims for “good source,” “high,” “more,” and “high potency.”

Code of Federal Regulations, 2010 CFR

2010-04-01

... antioxidant activity; that is, when there exists scientific evidence that, following absorption from the... of the nutrients with recognized antioxidant activity. The list of nutrients shall appear in letters... the term “antioxidant.” A nutrient content claim that characterizes the level of antioxidant nutrients...

Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study.

PubMed

Mente, Andrew; Dehghan, Mahshid; Rangarajan, Sumathy; McQueen, Matthew; Dagenais, Gilles; Wielgosz, Andreas; Lear, Scott; Li, Wei; Chen, Hui; Yi, Sun; Wang, Yang; Diaz, Rafael; Avezum, Alvaro; Lopez-Jaramillo, Patricio; Seron, Pamela; Kumar, Rajesh; Gupta, Rajeev; Mohan, Viswanathan; Swaminathan, Sumathi; Kutty, Raman; Zatonska, Katarzyna; Iqbal, Romaina; Yusuf, Rita; Mohammadifard, Noushin; Khatib, Rasha; Nasir, Nafiza Mat; Ismail, Noorhassim; Oguz, Aytekin; Rosengren, Annika; Yusufali, Afzalhussein; Wentzel-Viljoen, Edelweiss; Puoane, Thandi; Chifamba, Jephat; Teo, Koon; Anand, Sonia S; Yusuf, Salim

2017-10-01

The relation between dietary nutrients and cardiovascular disease risk markers in many regions worldwide is unknown. In this study, we investigated the effect of dietary nutrients on blood lipids and blood pressure, two of the most important risk factors for cardiovascular disease, in low-income, middle-income, and high-income countries. We studied 125 287 participants from 18 countries in North America, South America, Europe, Africa, and Asia in the Prospective Urban Rural Epidemiology (PURE) study. Habitual food intake was measured with validated food frequency questionnaires. We assessed the associations between nutrients (total fats, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, carbohydrates, protein, and dietary cholesterol) and cardiovascular disease risk markers using multilevel modelling. The effect of isocaloric replacement of saturated fatty acids with other fats and carbohydrates was determined overall and by levels of intakes by use of nutrient density models. We did simulation modelling in which we assumed that the effects of saturated fatty acids on cardiovascular disease events was solely related to their association through an individual risk marker, and then compared these simulated risk marker-based estimates with directly observed associations of saturated fatty acids with cardiovascular disease events. Participants were enrolled into the study from Jan 1, 2003, to March 31, 2013. Intake of total fat and each type of fat was associated with higher concentrations of total cholesterol and LDL cholesterol, but also with higher HDL cholesterol and apolipoprotein A1 (ApoA1), and lower triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ratio of apolipoprotein B (ApoB) to ApoA1 (all p trend <0·0001). Higher carbohydrate intake was associated with lower total cholesterol, LDL cholesterol, and ApoB, but also with lower HDL cholesterol and ApoA1, and higher triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ApoB-to-ApoA1 ratio (all p trend <0·0001, apart from ApoB [p trend =0·0014]). Higher intakes of total fat, saturated fatty acids, and carbohydrates were associated with higher blood pressure, whereas higher protein intake was associated with lower blood pressure. Replacement of saturated fatty acids with carbohydrates was associated with the most adverse effects on lipids, whereas replacement of saturated fatty acids with unsaturated fats improved some risk markers (LDL cholesterol and blood pressure), but seemed to worsen others (HDL cholesterol and triglycerides). The observed associations between saturated fatty acids and cardiovascular disease events were approximated by the simulated associations mediated through the effects on the ApoB-to-ApoA1 ratio, but not with other lipid markers including LDL cholesterol. Our data are at odds with current recommendations to reduce total fat and saturated fats. Reducing saturated fatty acid intake and replacing it with carbohydrate has an adverse effect on blood lipids. Substituting saturated fatty acids with unsaturated fats might improve some risk markers, but might worsen others. Simulations suggest that ApoB-to-ApoA1 ratio probably provides the best overall indication of the effect of saturated fatty acids on cardiovascular disease risk among the markers tested. Focusing on a single lipid marker such as LDL cholesterol alone does not capture the net clinical effects of nutrients on cardiovascular risk. Full funding sources listed at the end of the paper (see Acknowledgments). Copyright © 2017 Elsevier Ltd. All rights reserved.

[Effects of nitrogen application rates and straw returning on nutrient balance and grain yield of late sowing wheat in rice-wheat rotation].

PubMed

Zhang, Shan; Shi, Zu-liang; Yang, Si-jun; Gu, Ke-jun; Dai, Ting-bo; Wang, Fei; Li, Xiang; Sun, Ren-hua

2015-09-01

Field experiments were conducted to study the effects of nitrogen application rates and straw returning on grain yield, nutrient accumulation, nutrient release from straw and nutrient balance in late sowing wheat. The results showed that straw returning together with appropriate application of nitrogen fertilizer improved the grain yield. Dry matter, nitrogen, phosphorus and potassium accumulation increased significantly as the nitrogen application rate increased. At the same nitrogen application rate (270 kg N · hm(-2)), the dry matter, phosphorus and potassium accumulation of the treatment with straw returning were higher than that without straw returning, but the nitrogen accumulation was lower. Higher-rate nitrogen application promoted straw decomposition and nutrient release, and decreased the proportion of the nutrient released from straw after jointing. The dry matter, phosphorus and potassium release from straw showed a reverse 'N' type change with the wheat growing, while nitrogen release showed a 'V' type change. The nutrient surplus increased significantly with the nitrogen application rate. At the nitrogen application rate for the highest grain yield, nitrogen and potassium were surplus significantly, and phosphorus input could keep balance. It could be concluded that as to late sowing wheat with straw returning, applying nitrogen at 257 kg · hm(-2) and reducing potassium fertilizer application could improve grain yield and reduce nutrients loss.

Glacial runoff strongly influences food webs in Gulf of Alaska fjords

NASA Astrophysics Data System (ADS)

Arimitsu, M.; Piatt, J. F.; Mueter, F. J.

2015-12-01

Melting glaciers contribute large volumes of freshwater to the Gulf of Alaska coast. Rates of glacier volume loss have increased markedly in recent decades, raising concern about the eventual loss of glaciers as a source of freshwater in coastal waters. To better understand the influence of glacier melt water on fjord ecosystems, we sampled oceanography, nutrients, zooplankton, forage fish, and seabirds within four fjords in the coastal Gulf of Alaska. We used generalized additive models and geostatistics to identify the range of influence of glacier runoff in fjords of varying estuarine and topographic complexity. We also modeled the responses of chlorophyll a concentration, copepod biomass, fish and seabird abundance to physical, nutrient and biotic predictor variables. Physical and nutrient signatures of glacial runoff extended 10-20 km into coastal fjords. Glacially modified physical gradients and among-fjord differences explained 66% of the variation in phytoplankton abundance, which drives ecosystem structure at higher trophic levels. Copepod, euphausiid, fish and seabird distribution and abundance were also related to environmental gradients that could be traced to glacial freshwater input. Seabird density was predicted by prey availability and silica concentrations, which may indicate upwelling areas where this nutrient is in excess. Similarities in ecosystem structure among fjords were due to influx of cold, fresh, sediment and nutrient laden water, while differences were due to fjord topography and the relative importance of estuarine vs. ocean influences. We anticipate continued changes in the volume and magnitude of glacial runoff will affect coastal marine food webs in the future.

Influence of glacier runoff on ecosystem structure in Gulf of Alaska fjords

USGS Publications Warehouse

Arimitsu, Mayumi L.; Piatt, John F.; Mueter, Franz J.

2016-01-01

To better understand the influence of glacier runoff on fjord ecosystems, we sampled oceanographic conditions, nutrients, zooplankton, forage fish and seabirds within 4 fjords in coastal areas of the Gulf Alaska. We used generalized additive models and geostatistics to identify the range of glacier runoff influence into coastal waters within fjords of varying estuarine influence and topographic complexity. We also modeled the response of depth-integrated chlorophyll a concentration, copepod biomass, fish and seabird abundance to physical, nutrient and biotic predictor variables. The effects of glacial runoff were traced at least 10 km into coastal fjords by cold, turbid, stratified and generally nutrient-rich near-surface conditions. Glacially modified physical gradients, nutrient availability and among-fjord differences explained 67% of the variation in phytoplankton abundance, which is a driver of ecosystem structure at higher trophic levels. Copepod, euphausiid, fish and seabird distribution and abundance were related to environmental gradients that could be traced to glacial freshwater input, particularly turbidity and temperature. Seabird density was predicted by prey availability and silicate concentrations, which may be a proxy for upwelling areas where this nutrient is in excess. Similarities in ecosystem structure among fjords were attributable to an influx of cold, fresh and sediment-laden water, whereas differences were likely related to fjord topography and local differences in estuarine vs. ocean influence. We anticipate that continued changes in the timing and volume of glacial runoff will ultimately alter coastal ecosystems in the future.

Trend analysis of plasma insulin level around parturition in relation to parity in Saanen goats.

PubMed

Magistrelli, D; Rosi, F

2014-06-01

The present study investigated the effect of parity on plasma insulin level around parturition in Saanen goats. On d -14, -7, 0, 3, 7, 10, and 14 from parturition, plasma glucose, NEFA, free AA, cortisol, and insulin concentrations were analyzed in 10 primiparous and 10 multiparous goats. At parturition, BW of primiparous goats was about 75% of that of multiparous ones (P < 0.001) and then their milk production was lower than that of multiparous ones (P < 0.001). At parturition, glucose increased (P < 0.01) in both primiparous and multiparous goats and then decreased (P < 0.01) on d 3 of lactation, remaining higher (P < 0.01) in primiparous than multiparous goats until the end of the study period. In both groups, free AA decreased (P < 0.01) at parturition, returning to prepartum levels (P < 0.01) on d 3 of lactation without difference between groups. Only in multiparous goats, plasma NEFA increased at parturition (P < 0.01), returning to prepartum levels on d 14 (P < 0.01). Changes in glucose and AA could have been caused by cortisol, which increased (P < 0.01) at parturition in both primiparous and multiparous goats, returning to prepartum levels (P < 0.01) on d 7 of lactation, without difference between the parity groups. In multiparous goats, insulin decreased soon after parturition (P < 0.05), remaining at low levels until the end of the study period, whereas in primiparous goats, insulin did not vary until d 14 of lactation, when it decreased (P < 0.05) also in this group. Therefore, between d 3 and 14 of lactation, insulin was higher in primiparous than multiparous goats (P < 0.05). Only in primiparous goats, at kidding, insulin was negatively correlated to BW (P < 0.01), and after parturition it was negatively correlated with milk yield (P < 0.05) and plasma NEFA (P < 0.05). We hypothesize that higher insulin levels in primiparous Saanen goats, which are still immature at their first breeding season, acted to limit both the mobilization of bodily reserves and the capture of nutrients by the lactating mammary gland, thus providing nutrients for their own physical and physiological development.

Effect of dietary mannanoligosaccharide supplementation on nutrient digestibility, hindgut fermentation, immune response and antioxidant indices in dogs.

PubMed

Pawar, Mahesh M; Pattanaik, Ashok K; Sinha, Dharmendra K; Goswami, Tapas K; Sharma, Kusumakar

2017-01-01

Use of prebiotics in companion animal nutrition is often considered advantageous over probiotics because of the ease of handling, ability to withstand processing and storage etc. While most of the studies on prebiotic use in dogs have been done with processed food as basal diet, the response in relation to homemade diet feeding is not very well explored. The study was conducted to evaluate the effects of dietary mannanoligosaccharide (MOS) supplementation on nutrient digestibility, hindgut fermentation, immune response and antioxidant indices in dogs. Ten Spitz pups were divided into two groups: control (CON) with no supplementation, and experimental (MOS) wherein the basal diet was supplemented with MOS at 15 g/kg diet. All dogs were fed on a home-prepared diet for a period of 150 days. The study protocol included a digestion trial, periodic blood collection and analysis for lipid profile and erythrocytic antioxidants. Immune response of the animals was assessed towards the end of the feeding period. Results revealed no significant ( P > 0.05 ) variations in palatability score, intake and apparent digestibility of nutrients between the groups. Faecal score, faeces voided, faecal pH, concentrations of ammonia, lactate and short-chain fatty acids were comparable ( P > 0.05 ) between the two groups. Cell-mediated immune response, assessed as delayed-type of hypersensitivity response, was significantly higher ( P < 0.05 ) in the MOS group. The percent of lymphocyte sub-populations CD4+ and ratio of CD4+:CD8+ were also significantly ( P < 0.05 ) higher in MOS group. The serum IgG levels were similar ( P > 0.05 ) in both the groups. Supplementation of MOS lowered ( P < 0.05 ) serum total- and LDL- cholesterol levels, when compared with the control group. The erythrocytic antioxidant indices were similar ( P > 0.05 ) between the two groups. The results indicated that supplementation of MOS at the rate of 15 g/kg in the diet of dog augmented the cell-mediated immune response and serum lipid profile without any influences on digestibility of nutrients, hindgut fermentation and antioxidants indices.

Aquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlands

NASA Astrophysics Data System (ADS)

Tang, Yingying; Harpenslager, Sarah F.; van Kempen, Monique M. L.; Verbaarschot, Evi J. H.; Loeffen, Laury M. J. M.; Roelofs, Jan G. M.; Smolders, Alfons J. P.; Lamers, Leon P. M.

2017-02-01

The sequestration of nutrients from surface waters by aquatic macrophytes and sediments provides an important service to both natural and constructed wetlands. While emergent species take up nutrients from the sediment, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification and how plant species and nutrient loading affects nutrient distribution over plants, water and sediment. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum and Myriophyllum spicatum) and sediment types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m-2 d-1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while sediments showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates ( ≥ 21.4 mg P m-2 d-1), 50-90 % of added P ended up in sediments, with peat sediments becoming more easily saturated. For nitrogen (N), 45-90 % was either taken up by the sediment or lost to the atmosphere at loadings ≥ 62 mg N m-2 d-1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter but only for low loading rates (polishing) and not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands but also shows the differential effects of wetland sediment types and plant species. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove and recycle nutrients from both constructed wetlands and nutrient-loaded natural wetlands.

A Computational Study of Phenotype Switching in Bacillus Subtilis Biofilm

NASA Astrophysics Data System (ADS)

Smith, Howard; Wang, Xiaoling; Jiang, Yi

Bacillus Subtilis (B. Subtilis), is known to differentiate into three main phenotypes during biofilm growth. Novel techniques to track the spatial and temporal evolution of the three main phenotypes exhibited by B. Subtilis have been developed. However, the techniques do not explain the environmental causes of the phenotype switching and how this leads to the spatiotemporal organization of the biofilm. We hypothesize that cells switch their phenotype according to nutrients and autoinducer levels. We test the hypothesis using a hybrid agent-based and continuous model. The bacteria in our model are individual cells that can (i) grow and divide by the intake of nutrients, (ii) produce and secrete EPS, (iii) form spores and (iv) produce an auto inducer. Using a threshold for nutrient and thresholds for autoinducers, we were able to reproduce the experimental spatiotemporal dynamics. From our simulations we observed that in order to reproduce experimental results, two different autoinducers were necessary. The results also suggest that low-EPS producing biofilms generally obtained higher cell populations. Furthermore, most of the cells that become spore forming cells arise from matrix producing cells.

Effects of Storm Events on Bacteria and Nutrients in the Bayou Chico Watershed

NASA Astrophysics Data System (ADS)

Hobbs, S. E.; Truong, S.

2017-12-01

Levels of Escherichia coli and abiotic nutrients often increase in response to storm events due to urban runoff. The urban setting, aging septic systems, and ample pet waste (predominant sources of bacterial and nutrient contamination) that surround Bayou Chico, provide abundant possibilities for contamination. E. coli is a gram-negative, rod shaped bacteria commonly found in the intestines of animals; while some strains are harmless, others produce dangerous toxins that can cause side effects and sometimes death. Along with E. coli, inorganic nutrient concentrations (orthophosphate, nitrate/nitrite, and ammonium) are key indicators of water quality. Dissolved nutrients promote the growth of primary producers and excessive amounts lead to algal blooms, often reducing biodiversity. Four sites were sampled weekly in June and July 2017; during which, June had the highest rainfall in comparison to the past three years; these four sites represented three different sub-watersheds of the Bayou Chico Watershed, with differing land-use at each site. Historical nutrient and bacterial data from the Bream Fishermen Association was also compared and examined to determine long term trends and obtain a more in-depth understanding of the dynamics of water quality in th urban setting. E. coli levels were universally high (ranging from 98 to 12,997 MPN/100mL) for all sites and did not show observable correlations to rainfall; possibly influenced by the systemic and anomalous heavy precipitation during most of the summer study period. Nitrate was detected at levels between 2.5 and 154.0 µM, while ammonium levels ranged from 0 to 16.1 µM. Three of four stations showed extremely elevated dissolved inorganic nitrogen and ammonium while one station showed low levels of these nutrients. Correlations between these nutrient loads and rainfall, support the hypothesis that runoff into tributary creeks contributes significant inorganic nutrient loads to the Bayou Chico urban estuary.

Energy and nutrient consumption in Mexican women 12-49 years of age: analysis of the National Nutrition Survey 1999.

PubMed

Barquera, Simón; Rivera, Juan A; Espinosa-Montero, Juan; Safdie, Margarita; Campirano, Fabricio; Monterrubio, Eric A

2003-01-01

To describe the reported energy and nutrient intake and adequacies in Mexican women. A 24-hour dietary recall was used to obtain nutrient intake in a representative sub-sample of 2,630 women from 12 to 49 years of age from the National Nutrition Survey 1999. Nutrient adequacies were estimated using the Dietary Reference Intakes and stratified according to region, area (urban or rural), socioeconomic status and obesity status (non-obese: BMI < 30 kg/m2, obese: > or = 30 kg/m2). Differences were analyzed using linear regression for complex surveys of log-transformed intake and adequacy, adjusting for multiple comparisons with the Bonferroni test. The median national energy intake was 1,471 kcal. The Risk of Inadequacy (RI) (prevalence of adequacy < 50%) was: vitamin A: 38.3%, vitamin C: 45.5%, and folate: 34.3%. Carbohydrates, folate, iron and calcium intake was significantly higher in rural than in urban areas. The RI was higher in women of the lowest socioeconomic status tertile for all nutrients with the exception of carbohydrates and calcium. Macro-nutrient adequacies were significantly higher in non-obese women. Differences within the country among regions, rural and urban areas, and socioeconomic status tertile reflect an increasing availability of inexpensive calorie-dense foods in marginal groups. However, total energy, cholesterol, saturated and total fat were consumed in greater quantities by women from the higher socioeconomic status tertile and from urban areas. These patterns could be a contributing factor to the rise of obesity and other non-communicable nutrition-related chronic diseases in Mexico. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Assessment of temporal and spatial water quality in international Gomishan Lagoon, Iran, using multivariate analysis.

PubMed

Basatnia, Nabee; Hossein, Seyed Abbas; Rodrigo-Comino, Jesús; Khaledian, Yones; Brevik, Eric C; Aitkenhead-Peterson, Jacqueline; Natesan, Usha

2018-04-29

Coastal lagoon ecosystems are vulnerable to eutrophication, which leads to the accumulation of nutrients from the surrounding watershed over the long term. However, there is a lack of information about methods that could accurate quantify this problem in rapidly developed countries. Therefore, various statistical methods such as cluster analysis (CA), principal component analysis (PCA), partial least square (PLS), principal component regression (PCR), and ordinary least squares regression (OLS) were used in this study to estimate total organic matter content in sediments (TOM) using other parameters such as temperature, dissolved oxygen (DO), pH, electrical conductivity (EC), nitrite (NO 2 ), nitrate (NO 3 ), biological oxygen demand (BOD), phosphate (PO 4 ), total phosphorus (TP), salinity, and water depth along a 3-km transect in the Gomishan Lagoon (Iran). Results indicated that nutrient concentration and the dissolved oxygen gradient were the most significant parameters in the lagoon water quality heterogeneity. Additionally, anoxia at the bottom of the lagoon in sediments and re-suspension of the sediments were the main factors affecting internal nutrient loading. To validate the models, R 2 , RMSECV, and RPDCV were used. The PLS model was stronger than the other models. Also, classification analysis of the Gomishan Lagoon identified two hydrological zones: (i) a North Zone characterized by higher water exchange, higher dissolved oxygen and lower salinity and nutrients, and (ii) a Central and South Zone with high residence time, higher nutrient concentrations, lower dissolved oxygen, and higher salinity. A recommendation for the management of coastal lagoons, specifically the Gomishan Lagoon, to decrease or eliminate nutrient loadings is discussed and should be transferred to policy makers, the scientific community, and local inhabitants.

Nutrient limitation restricts growth and reproductive output in a tropical montane cloud forest bromeliad: findings from a long-term forest fertilization experiment.

PubMed

Lasso, Eloisa; Ackerman, James D

2013-01-01

From studies in seasonal lowland tropical forests, bromeliad epiphytes appear to be limited mainly by water, and to a lesser extent by nutrient supply, especially phosphorous. Less is understood about the mineral nutrition of tropical montane cloud forest (TMCF) epiphytes, even though their highest diversity is in this habitat. Nutrient limitation is known to be a key factor restricting forest productivity in TMCF, and if epiphytes are nutritionally linked to their host trees, as has been suggested, we would expect that they are also nutrient limited. We studied the effect of a higher nutrient input on reproduction and growth of the tank bromeliad Werauhia sintenisii in experimental plots located in a TMCF in Puerto Rico, where all macro- and micronutrients had been added quarterly starting in 1989 and continuing throughout the duration of this study. We found that bromeliads growing in fertilized plots were receiving litterfall with higher concentrations of N, P, and Zn and had higher concentrations of P, Zn, Fe, Al, and Na in their vegetative body. The N:P ratios found (fertilized = 27.5 and non-fertilized = 33.8) suggest that W. sintenisii may also be phosphorous limited as are lowland epiphytes. Fertilized plants had slightly longer inflorescences, and more flowers per inflorescence, than non-fertilized plants, but their flowers produced nectar in similar concentrations and quantities. Fertilized plants produced more seeds per fruit and per plant. Frequency of flowering in two consecutive years was higher for fertilized plants than for controls, suggesting that fertilized plants overcome the cost of reproduction more readily than non-fertilized plants. These results provide evidence that TMCF epiphytic bromeliads are nutrient limited like their lowland counterparts.

TAS2R38 bitter taste genetics, dietary vitamin C, and both natural and synthetic dietary folic acid predict folate status, a key micronutrient in the pathoaetiology of adenomatous polyps.

PubMed

Lucock, Mark; Ng, Xiaowei; Boyd, Lyndell; Skinner, Virginia; Wai, Ron; Tang, Sa; Naylor, Charlotte; Yates, Zoë; Choi, Jeong-Hwa; Roach, Paul; Veysey, Martin

2011-08-01

Taste perception may influence dietary preferences and nutrient intakes contributing to diet-related disease susceptibility. This study examined bitter taste genetics and whether variation in the TAS2R38 gene at three polymorphic loci (A49P, V262A and I296V) could alter dietary and systemic folate levels and dietary vitamin C intake, and whether a nutrigenetic circuit existed that might link bitter taste, folate/antioxidant status and risk for a colonic adenomatous polyp. TAS2R38 diplotype predicted bitter taste (PROP) phenotype (p value <0.00001) and red cell folate status (p=0.0179) consistent with the diplotype that has the broadest range of bitter perception (AVI/PAV) also possessing the highest average red cell folate value. However, TAS2R38 diplotype did not predict dietary intake of methylfolic acid, pteroylmonoglutamic acid or total folic acid. Neither did it predict dietary intake of vitamin C. Despite this, intake of dietary folate predicts red cell folate with analysis pointing to a key nutrient-nutrient interaction between vitamin C intake and systemic folate status. Analysis of 38 patients with an adenomatous polyp and 164 controls showed that individually, dietary nutrient intake, nutrient status and taste diplotype did not influence polyp risk. However, red cell folate status (in individuals below the population median value) did interact with bitter taste diplotype (AVI/PAV) to predict polyp risk (p=0.0145). Furthermore, synthetic folic acid (below median intake) was statistically associated with adenoma occurrence (p=0.0215); individuals with adenomatous polyps had a 1.77× higher intake than controls. Additionally, stepwise regression taking account of all dietary nutrients showed a tight relationship between methylfolic acid (but not pteroylmonoglutamic acid) intake and red cell folate level in those with a low folate status and occurrence of an adenomatous polyp (p=0.0039). These findings point to a role for folate in the pathoaetiology of adenomatous polyps, with the natural and synthetic vitamers not necessarily having the same biological effect. This journal is © The Royal Society of Chemistry 2011

Short-term effect of nutrient availability and rainfall distribution on biomass production and leaf nutrient content of savanna tree species.

PubMed

Barbosa, Eduardo R M; Tomlinson, Kyle W; Carvalheiro, Luísa G; Kirkman, Kevin; de Bie, Steven; Prins, Herbert H T; van Langevelde, Frank

2014-01-01

Changes in land use may lead to increased soil nutrient levels in many ecosystems (e.g. due to intensification of agricultural fertilizer use). Plant species differ widely in their response to differences in soil nutrients, and for savannas it is uncertain how this nutrient enrichment will affect plant community dynamics. We set up a large controlled short-term experiment in a semi-arid savanna to test how water supply (even water supply vs. natural rainfall) and nutrient availability (no fertilisation vs. fertilisation) affects seedlings' above-ground biomass production and leaf-nutrient concentrations (N, P and K) of broad-leafed and fine-leafed tree species. Contrary to expectations, neither changes in water supply nor changes in soil nutrient level affected biomass production of the studied species. By contrast, leaf-nutrient concentration did change significantly. Under regular water supply, soil nutrient addition increased the leaf phosphorus concentration of both fine-leafed and broad-leafed species. However, under uneven water supply, leaf nitrogen and phosphorus concentration declined with soil nutrient supply, this effect being more accentuated in broad-leafed species. Leaf potassium concentration of broad-leafed species was lower when growing under constant water supply, especially when no NPK fertilizer was applied. We found that changes in environmental factors can affect leaf quality, indicating a potential interactive effect between land-use changes and environmental changes on savanna vegetation: under more uneven rainfall patterns within the growing season, leaf quality of tree seedlings for a number of species can change as a response to changes in nutrient levels, even if overall plant biomass does not change. Such changes might affect herbivore pressure on trees and thus savanna plant community dynamics. Although longer term experiments would be essential to test such potential effects of eutrophication via changes in leaf nutrient concentration, our findings provide important insights that can help guide management plans that aim to preserve savanna biodiversity.

Relative validity of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and the block kids' food questionnaire for estimating beverage, calcium, and vitamin D intakes by children.

PubMed

Marshall, Teresa A; Eichenberger Gilmore, Julie M; Broffitt, Barbara; Stumbo, Phyllis J; Levy, Steven M

2008-03-01

Food frequency questionnaires are commonly developed and subsequently used to investigate relationships between dietary intake and disease outcomes; such tools should be validated in the population of interest. We investigated the relative validities of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and Block Kids' Food Questionnaire in assessing beverage, calcium, and vitamin D intakes using 3-day diaries for reference. Cross-sectional. Children who completed Iowa Fluoride Study nutrient questionnaire at age 9.0+/-0.7 years (n=223) and/or the Block Kids' Food Questionnaire at age 8.3+/-0.3 years (n=129) and 3-day diaries during similar time periods. Intakes of beverages, calcium, and vitamin D. Spearman correlation coefficients, weighted kappa statistics, and percentages of exact agreement were used to estimate relative validities. Correlations between milk intakes (r=0.572) reported on diaries and the Iowa Fluoride Study nutrient questionnaires were higher than correlations for 100% juice, juice drinks, soda pop, and water (r=0.252 to 0.379). Correlations between milk intakes (r=0.571) and 100% juice intakes (r=0.550) reported on diaries and Block Kids' Food Questionnaires were higher than correlations for other beverages (r=0.223 to 0.326). Correlations with diaries for calcium (r=0.462) and vitamin D (r=0.487) intakes reported on Iowa Fluoride Study nutrient questionnaires were similar to correlations with diaries for calcium (r=0.515) and vitamin D (r=0.512) reported on Block Kids' Food Questionnaires. Weighted kappa statistics were similar between the Iowa Fluoride Study nutrient questionnaires and the Block Kids' Food Questionnaires for milk, 100% juice, and vitamin D, but were higher on the Iowa Fluoride Study nutrient questionnaires than on the Block Kids' Food Questionnaires for calcium. Percentages of exact agreement were higher for calcium, but lower for vitamin D for intakes reported on the Iowa Fluoride Study nutrient questionnaires compared to the Block Kids' Food Questionnaires relative to diaries. Both the Iowa Fluoride Study nutrient questionnaire and the Block Kids' Food Questionnaire provide reasonable estimates of milk, calcium, and vitamin D intakes when compared to 3-day diaries.

Relation of water quality to land use in the drainage basins of six tributaries to the lower Delaware River, New Jersey, 2002-07

USGS Publications Warehouse

Baker, Ronald J.; Esralew, Rachel A.

2010-01-01

Concentrations and loads of water-quality constituents in six streams in the lower Delaware River Basin of New Jersey were determined in a multi-year study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection. Two streams receive water from relatively undeveloped basins, two from largely agricultural basins, and two from heavily urbanized basins. Each stream was monitored during eight storms and at least eight times during base flow during 2002-07. Sampling was conducted during base flow before each storm, when stage was first observed to rise, and several times during the rising limb of the hydrographs. Agricultural and urban land use has resulted in statistically significant increases in loads of nitrogen and phosphorus species relative to loads in undeveloped basins. For example, during the growing season, median storm flow concentrations of total nitrogen in the two streams in agricultural areas were 6,290 and 1,760 mg/L, compared to 988 and 823 mg/L for streams in urban areas, and 719 and 333 mg/L in undeveloped areas. Although nutrient concentrations and loads were clearly related to land useurban, agricultural, and undeveloped within the drainage basins, other basin characteristics were found to be important. Residual nutrients entrapped in lake sediments from streams that received effluent from recently removed sewage-treatment plants are hypothesized to be the cause of extremely high levels of nutrient loads to one urban stream, whereas another urban stream with similar land-use percentages (but without the legacy of sewage-treatment plants) had much lower levels of nutrients. One of the two agricultural streams studied had higher nutrient loads than the other, especially for total phosphorous and organic nitrogen. This difference appears to be related to the presence (or absence) of livestock (cattle).

Effects of water addition to total mixed ration on water intake, nutrient digestibility, wool cortisol and blood indices in Corriedale ewes.

PubMed

Nejad, Jalil Ghassemi; Kim, Byong-Wan; Lee, Bae-Hun; Kim, Ji-Yung; Sung, Kyung-Il

2017-10-01

The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Nine non-pregnant Corriedale ewes (ave. body weight = 41±3.5 kg) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate 3×3 Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.

Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods

PubMed Central

Safwat, A. M.; Sarmiento-Franco, L.; Santos-Ricalde, R. H.; Nieves, D.; Sandoval-Castro, C. A.

2015-01-01

This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets. PMID:26104524

Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods.

PubMed

Safwat, A M; Sarmiento-Franco, L; Santos-Ricalde, R H; Nieves, D; Sandoval-Castro, C A

2015-08-01

This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets.

Environmental versus genetic influences on growth rates of the corals Pocillopora eydouxi and Porites lobata (Anthozoa: Scleractinia)

USGS Publications Warehouse

Smith, L.W.; Wirshing, H.H.; Baker, A.C.; Birkeland, C.

2008-01-01

Reciprocal transplant experiments of the corals Pocillopora eydouxi Milne Edwards & Haime and Porites lobata Dana were carried out for an 18-month period from September 2004 to March 2006 between two back reef pools on Ofu Island, American Samoa, to test environmental versus genetic effects on skeletal growth rates. Skeletal growth of P. eydouxi showed environmental but not genetic effects, resulting in doubling of growth in Pool 300 compared with Pool 400. There were no environmental or genetic effects on skeletal growth of P. lobata. Pool 300 had more frequent and longer durations of elevated seawater temperatures than Pool 400, characteristics likely to decrease rather than increase skeletal growth. Pool 300 also had higher nutrient levels and flow velocities than Pool 400, characteristics that may increase skeletal growth. However, higher nutrient levels would be expected to increase skeletal growth in both species, but there was no difference between the pools in P. lobata growth. P. eydouxi is much more common in high-energy environments than P. lobata; thus the higher flow velocities in Pool 300 than in Pool 400 may have positively affected skeletal growth of P. eydouxi while not having a detectable effect on P. lobata. The greater skeletal growth of P. eydouxi in Pool 300 occurred despite the presence of clade D zooxanthellae in several source colonies in Pool 300, a genotype known to result in greater heat resistance but slower skeletal growth. Increased skeletal growth rates in higher water motion may provide P. eydouxi a competitive advantage in shallow, high-energy enviromnents where competition for space is intense. ?? 2008 by University of Hawai'i Press. All rights reserved.

Effects of plant diversity on microbial nitrogen and phosphorus dynamics in soil

NASA Astrophysics Data System (ADS)

Prommer, Judith; Braun, Judith; Daly, Amanda; Gorka, Stefan; Hu, Yuntao; Kaiser, Christina; Martin, Victoria; Meyerhofer, Werner; Walker, Tom W. N.; Wanek, Wolfgang; Wasner, Daniel; Wiesenbauer, Julia; Zezula, David; Zheng, Qing; Richter, Andreas

2017-04-01

There is a general consensus that plant diversity affects many ecosystem functions. One example of such an effect is the enhanced aboveground and belowground plant biomass production with increasing species richness, with implications for carbon and nutrient distribution in soil. The Jena Experiment (http://www.the-jena-experiment.de/), a grassland biodiversity experiment established in 2002 in Germany, comprises different levels of plant species richness and different numbers of plant functional groups. It provides the opportunity to examine how changes in biodiversity impact on microbially-mediated nutrient cycling processes. We here report on plant diversity and plant functional composition effects on growth and nitrogen and phosphorus transformation rates, including nitrogen use efficiency, of microbial communities. Microbial growth rates and microbial biomass were positively affected by increasing plant species richness. Amino acid and ammonium concentrations in soil were also positively affected by plant species richness, while phosphate concentrations in contrast were negatively affected. The cycling of organic N in soils (estimated as gross protein depolymerization rates) increased about threefold with plant diversity, while gross N and P mineralization were not significantly affected by either species or functional richness. Microbial nitrogen use efficiency did not respond to different levels of plant diversity but was very high (0.96 and 0.98) across all levels of plant species richness, demonstrating a low N availability for microbes. Taken together this indicates that soil microbial communities were able to meet the well-documented increase in plant N content with species richness, and also the higher N demand of the microbial community by increasing the recycling of organic N such as proteins. In fact, the microbial community even overcompensated the increased plant and microbial N demand, as evidenced by increased levels of free amino acids and ammonium in the soil solution at higher species richness. A possible explanation for increased organic nitrogen transformation rates is the increased microbial biomass, which has previously been related to higher quantity and variety of plant derived compounds that are available to the microbial communities at higher plant diversity. Given that this explanation is right, it is interesting to note that the additional (plant-derived) microbial biomass at higher species richness, did not translate in higher soil P mineralization rates or phosphate availability.

Dietary nutrient levels regulate protein and carbohydrate intake, gluconeogenic/glycolytic flux and blood trehalose level in the insect Manduca sexta L.

PubMed

Thompson, S N; Borchardt, D B; Wang, L-W

2003-03-01

This study examined the effects of dietary casein and sucrose levels on nutrient intake, and distinguished the effects of carbohydrate and protein consumption on growth, fat content, pyruvate metabolism and blood trehalose level of 5th instar Manduca sexta larvae. Growth increased with increasing casein consumption but was unaffected by carbohydrate intake. Fat content also increased with carbohydrate consumption, but on carbohydrate-free diets fat content increased with increased protein consumption. Blood trehalose level and pyruvate metabolism were examined by nuclear magnetic resonance spectroscopy analysis of blood following administration of (3-(13)C)pyruvate. On diets containing sucrose, blood trehalose increased with increasing carbohydrate intake, and on most diets trehalose was synthesized entirely from dietary sucrose. Pyruvate cycling, indicated by the alanine C2/C3 (13)C enrichment ratio, increased with carbohydrate consumption reflecting increased glycolysis, and pyruvate decarboxylation exceeded carboxylation on all sucrose diets. Larvae that consumed <75 mg/day sucrose were gluconeogenic, based on the [2 (trehalose C6)(Glx C3/C2)]/alanine C2] (13)C enrichment ratio. On carbohydrate-free diets, blood trehalose levels were low and maintained entirely by gluconeogenesis. Blood trehalose level increased with increasing protein intake. Pyruvate cycling was very low, although many insects displayed higher levels of pyruvate decarboxylation than carboxylation. All gluconeogenic larvae displayed alanine (13)C enrichment ratios <0.35 and had blood trehalose levels <50 mM.

Plant response to nutrient availability across variable bedrock geologies

USGS Publications Warehouse

Castle, S.C.; Neff, J.C.

2009-01-01

We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

Relations of principal components analysis site scores to algal-biomass, habitat, basin-characteristics, nutrient, and biological-community data in the Upper Wabash River Basin, Indiana, 2003

USGS Publications Warehouse

Leer, Donald R.; Caskey, Brian J.; Frey, Jeffrey W.; Lowe, B. Scott

2007-01-01

The values for nutrients (nitrate, total Kjeldahl nitrogen, total nitrogen, and total phosphorus) and chlorophyll a (periphyton and seston) were compared to published U.S. Environmental Protection Agency (USEPA) values for Aggregate Nutrient Ecoregions VI and VII and USEPA Level III Ecoregions 55 and 56. Several nutrient values were greater than the 25th percentile of the published USEPA values. Chlorophyll a (periphyton and seston) values either were greater than the 25th percentile of published USEPA values or extended data ranges in the Aggregate Nutrient and Level III Ecoregions. If the proposed values for the 25th percentile were adopted as nutrient water-quality criteria, many samples in the Upper Wabash River Basin would have exceeded the criteria.

Nutritional quality, functional properties and anti-nutrient compositions of the larva of Cirina forda (Westwood) (Lepidoptera: Saturniidae)

PubMed Central

Omotoso, O.T.

2006-01-01

Determination of the proximate, nutritionally valuable minerals and anti-nutrient compositions in larvae of Cirina forda (W) showed that they contained high levels of protein, (55.50%±1.20%) with ash, moisture, fat, and carbohydrate levels being (10.26%±0.01%), (10.85%±0.38%), (4.68%±0.01%) and (18.70%±0.84%) respectively. Fibre was not detected. Protein solubility was higher in alkaline media than in acidic media while the isoelectric points were pH 4, 6 and 9 indicating that C. forda may be useful in food formulations involving foods like meat products. Phosphorus had the highest value of (215.54±0.21) mg/100 g while manganese had the lowest value of (1.14±0.10) mg/100 g. Copper, Co, Pb, Cr and Ni were not available. Water absorption capacity was (300%±0.15%), oil absorption capacity was (358.44%±0.21%) and foaming stability was (3%±0.00%). The results of anti-nutritional analysis revealed that oxalate and phytic acid contents were (4.11±0.05) mg/100 g and (1.02±0.00) mg/100 g respectively and that these values fell within nutritionally accepted values. Tannin was not detected in C. forda. C. forda, a rich source of animal nutrients, usable in human diets and animal feeds formulations. PMID:16365926

Water mass interaction in the confluence zone of the Daning River and the Yangtze River--a driving force for algal growth in the Three Gorges Reservoir.

PubMed

Holbach, Andreas; Wang, Lijing; Chen, Hao; Hu, Wei; Schleicher, Nina; Zheng, Binghui; Norra, Stefan

2013-10-01

Increasing eutrophication and algal bloom events in the Yangtze River Three Gorges Reservoir, China, are widely discussed with regard to changed hydrodynamics and nutrient transport and distribution processes. Insights into water exchange and interaction processes between water masses related to large-scale water level fluctuations in the reservoir are crucial to understand water quality and eutrophication dynamics. Therefore, confluence zones of tributaries with the Yangtze River main stream are dedicated key interfaces. In this study, water quality data were recorded in situ and on-line in varying depths with the MINIBAT towed underwater multi-sensor system in the confluence zone of the Daning River and the Yangtze River close to Wushan City during 1 week in August 2011. Geostatistical evaluation of the water quality data was performed, and results were compared to phosphorus contents of selective water samples. The strongly rising water level throughout the measurement period caused Yangtze River water masses to flow upstream into the tributary and supply their higher nutrient and particulate loads into the tributary water body. Rapid algal growth and sedimentation occurred immediately when hydrodynamic conditions in the confluence zone became more serene again. Consequently, water from the Yangtze River main stream can play a key role in providing nutrients to the algal bloom stricken water bodies of its tributaries.

Self-perceived level of competitiveness, tension, and dependency and lifestyles in the 'Seguimiento Universidad de Navarra' cohort study.

PubMed

Unzueta, C R; Lahortiga-Ramos, F; Santiago, S; Zazpe, I; Molero, P; Sánchez-Villegas, A; Martínez-González, M A

2018-04-01

The objective of this study is to assess the differences in lifestyles according to levels of self-perceived competitiveness, psychological tension, and dependency in a Mediterranean cohort of university graduates. Levels of personality traits, food consumption, nutrient intake, eating attitudes, physical activity, sedentary lifestyle, and alcohol and tobacco consumption were assessed through a questionnaire administered at baseline. This was a cross-sectional study in the context of the Seguimiento Universidad de Navarra cohort. Participants are 15,346 Spanish adults. Participants with a high level of self-perceived competitiveness consumed more vegetables and fish but less refined grains; they had higher protein intake and healthier eating attitudes. They were more physically active and less likely to be smokers. Participants with a high level of tension or dependency were less physically active, and participants more dependent also had poorer adherence to the Mediterranean diet. Self-perceived personality traits, especially the trait of competitiveness, are likely to be associated with healthier dietary patterns, better nutrient profile, better eating attitudes, physical activity, and less exposure to smoking. The use of short questions about self-perceived levels of competitiveness, psychological tension, and dependency can contribute to add additional information when assessing lifestyles and diet in adults. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Assessment of Dietary Intake of Children with Chronic Kidney Disease

PubMed Central

Hui, W. F.; Betoko, Aisha; Savant, Jonathan D.; Abraham, Alison G.; Greenbaum, Larry A.; Warady, Bradley; Moxey-Mims, Marva M.; Furth, Susan L.

2017-01-01

Objective Our aim was to characterize the nutrient intake of children with chronic kidney disease (CKD) relative to recommended intake levels. Methods We conducted a cross-sectional study of dietary intake assessed by food frequency questionnaire (FFQ) in The North American Chronic Kidney Disease in Children (CKiD) prospective cohort study. Nutrient intake was analyzed to estimate the daily consumption levels of various nutrients and compared to national guidelines for intake. Results There were 658 FFQs available for analysis; 69.9% of respondents were boys, with a median age (Interquartile range [IQR]) of 11 years (8–15). Median daily sodium, potassium and phosphorus intake of the cohort was 3089 mg (2294–4243), 2384 mg (1804–3076) and 1206 mg (894–1612) respectively. Sodium and phosphorus consumptions were higher than recommended in all age groups. Caloric intake decreased with dropping glomerular filtration rate (p=0.003). Median daily caloric intakes were 1307 kcal in male children 2–3 years old, 1875 kcal in 4–8 year old, 1923 kcal in those 9–13 years old, and 2427 kcal in those 14–18 years old. Respective levels for girls were 1467 kcal, 1736 kcal, 1803 kcal, and 2281 kcal. Median protein intake exceeded recommended levels in all age groups, particularly among younger participants. Younger children were more likely than older children to exceed the recommended intakes for phosphorus (p<0.001) and the age-specific recommended caloric intake (p<0.001). Macronutrient distribution (carbohydrate: fat: protein) was consistent with recommendation. Conclusions Children in the CKiD cohort consumed more sodium, phosphorus, protein and calories than recommended. The gap between actual consumption and recommendations indicates a need for improved nutritional counseling and monitoring. PMID:27687620

MAPK14/p38α-dependent modulation of glucose metabolism affects ROS levels and autophagy during starvation.

PubMed

Desideri, Enrico; Vegliante, Rolando; Cardaci, Simone; Nepravishta, Ridvan; Paci, Maurizio; Ciriolo, Maria Rosa

2014-09-01

Increased glycolytic flux is a common feature of many cancer cells, which have adapted their metabolism to maximize glucose incorporation and catabolism to generate ATP and substrates for biosynthetic reactions. Indeed, glycolysis allows a rapid production of ATP and provides metabolic intermediates required for cancer cells growth. Moreover, it makes cancer cells less sensitive to fluctuations of oxygen tension, a condition usually occurring in a newly established tumor environment. Here, we provide evidence for a dual role of MAPK14 in driving a rearrangement of glucose metabolism that contributes to limiting reactive oxygen species (ROS) production and autophagy activation in condition of nutrient deprivation. We demonstrate that MAPK14 is phosphoactivated during nutrient deprivation and affects glucose metabolism at 2 different levels: on the one hand, it increases SLC2A3 mRNA and protein levels, resulting in a higher incorporation of glucose within the cell. This event involves the MAPK14-mediated enhancement of HIF1A protein stability. On the other hand, MAPK14 mediates a metabolic shift from glycolysis to the pentose phosphate pathway (PPP) through the modulation of PFKFB3 (6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase 3) degradation by the proteasome. This event requires the presence of 2 distinct degradation sequences, KEN box and DSG motif Ser273, which are recognized by 2 different E3 ligase complexes. The mutation of either motif increases PFKFB3 resistance to starvation-induced degradation. The MAPK14-driven metabolic reprogramming sustains the production of NADPH, an important cofactor for many reduction reactions and for the maintenance of the proper intracellular redox environment, resulting in reduced levels of ROS. The final effect is a reduced activation of autophagy and an increased resistance to nutrient deprivation.

Effect of gamma irradiation on nutrient digestibility in SPF mini-pig

NASA Astrophysics Data System (ADS)

Lee, Jun-Yeob; Cho, Sung-Back; Kim, Yoo-Yong; Ohh, Sang-Jip

2011-01-01

This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 °C for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher ( p<0.05) than those of autoclaved diets regardless of diet type. Digestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

Effect of ambient temperature on nutrient digestibility and nitrogen balance in sheep fed brown-midrib maize silage.

PubMed

Gorniak, Tobias; Meyer, Ulrich; Südekum, Karl-Heinz; Dänicke, Sven

2014-01-01

The aim of the experiment was to determine the impact of heat stress on nutrient digestibility and nitrogen balance in sheep fed silages differing in fibre quality. The digestibility trial was conducted at three different ambient temperatures (15°C, 25°C and 35°C for 24 h/d). The tested brown-midrib maize (Bm) silage had a higher nutrient digestibility, except for ether extract (EE) and a higher metabolisable energy (ME) content than the control maize (Con) silage. Nitrogen (N) excretion with faeces was higher but N excretion with urine was lower for sheep fed Bm silage, subsequently N balance did not differ between the two silages. Temperature had no effect on nutrient digestibility, except for crude protein (CP), but N excretion with urine was lower at elevated temperatures. A diet by temperature interaction was found for dry matter (DM) and organic matter (OM) digestibility. When the ambient temperature increased from 15°C to 25°C, the DM and OM digestibility increased in animals fed Con silage, but decreased in animals fed Bm silage. Concomitantly, ME estimated from digestible nutrients was higher for Bm than for Con at 15°C, but no differences were found at 25°C and 35°C. Effects of diet by temperature interaction, furthermore, were observed for EE and CP digestibility. Therefore, forage quality has to be considered when feeding heat-stressed animals.

Incorporation of 3H-thymidine by different prokaryotic groups in relation to temperature and nutrients in a lacustrine ecosystem.

PubMed

Boucher, Delphine; Richardot, Mathilde; Thénot, Aurélie; Debroas, Didier

2006-10-01

The incorporation of [3H-methyl] thymidine (3H-TdR) by Eubacteria, bacterial groups (alpha- and beta-Proteobacteria, Cytophaga-Flavobacter), and Archaea was measured according to temperature (7 and 17 degrees C) and nutrient levels (nitrogen, phosphorus, and carbon) in a lacustrine system (Sep, France). Short-term incubation was performed using a combination of microautoradiography and fluorescent in situ hybridization. Irrespective of the temperatures and nutrients studied, all the major phylogenetic bacterial groups assimilated 3H-TdR, and in most of the treatments studied, the proportion of beta-Proteobacteria taking up 3H-TdR was higher than those in the other bacterial groups. The proportion of Bacteria and different bacterial groups studied incorporating 3H-TdR were significantly increased, approximately 1.5-fold, by temperature except for alpha-Proteobacteria (7.6-fold). The nutrient effect was not the same for the different bacterial groups according to the temperatures studied. The proportions of alpha-Proteobacteria (at both temperatures) and Cytophaga-Flavobacter (at 7 degrees C) taking up 3H-TdR were significantly decreased and increased by adding N and P, respectively. Also, adding N, P, and C increased and decreased the percentage of beta-Proteobacteria incorporating 3H-TdR at 7 and 17 degrees C, respectively. The archaeal community showed a similar proportion of active cells (i.e., 3H-TdR) to the bacterial community, and uptake of 3H-TdR by Archaea was significantly increased (P < 0.05) by both temperature and nutrients. Thus, the assimilation of 3H-TdR by bacterial groups and Archaea in lacustrine system is significantly controlled by both temperature and nutrients.

An evaluation of the sustainability of onsite wastewater treatment systems for nutrient management.

PubMed

Diaz-Elsayed, Nancy; Xu, Xiaofan; Balaguer-Barbosa, Maraida; Zhang, Qiong

2017-09-15

The impairment of water bodies from nutrient pollution is a challenging environmental problem that could lead to high eutrophic conditions, fish kills, and human illness, while negatively impacting industries that rely on thriving water bodies. Onsite wastewater treatment systems (OWTSs) are a major source of nutrients, however no prior studies have conducted a holistic sustainability assessment of OWTSs that considers their ability to manage nutrients at the household-level in the United States. The aim of this study is therefore to evaluate the environmental and economic impacts of conventional and advanced OWTSs with respect to their ability to remove total nitrogen (TN). Septic tank and drainfield materials were varied for conventional systems, and the advanced systems evaluated consisted of aerobic treatment units (ATUs) and passive nitrogen reduction systems (PNRSs) with nitrification and denitrification stages. Life cycle assessment and life cycle cost analysis were performed to evaluate OWTSs operating in different soil and temperature conditions. Nutrient management of the advanced OWTSs outperformed the conventional systems (96.7-100% vs. 61-65% TN removal), and resulted in less than 40% of the freshwater (0.06-0.14 vs. 0.37-0.40 kg P-eq/kg TN) and marine eutrophication (0.04-0.06 vs. 0.54-0.65 kg N-eq/kg TN). However, the tradeoff for nutrient management was higher life cycle costs ($101-$121 vs. $45-$58 USD 2015/kg TN) and environmental impacts for the remaining impact categories. Lastly, when the TN removed by the drainfield was <20%, the advanced system had lower impacts than conventional OWTSs across all impact categories except ecotoxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hot tadpoles from cold environments need more nutrients--life history and stoichiometry reflects latitudinal adaptation.

PubMed

Liess, Antonia; Rowe, Owen; Guo, Junwen; Thomsson, Gustaf; Lind, Martin I

2013-11-01

1. High-latitude species (and populations within species) are adapted to short and cold summers. They often have high growth and development rates to fully use the short growing season and mature before the onset of winter. 2. Within the context of ecological stoichiometry theory, this study combines ecology with evolution by relating latitudinal life-history adaptations to their molecular consequences in body nutrient composition in Rana temporaria tadpoles. 3. Temperature and food quality were manipulated during the development of tadpoles from Arctic and Boreal origins. We determined tadpole growth rate, development rate, body size and nutrient content, to test whether (i) Arctic tadpoles could realize higher growth rates and development rates with the help of higher-quality food even when food quantity was unchanged, (ii) Arctic and Boreal tadpoles differed in their stoichiometric (and life history) response to temperature changes, (iii) higher growth rates lead to higher tadpole P content (growth rate hypothesis) and (iv) allometric scaling affects tadpole nutrient allocation. 4. We found that especially Arctic tadpoles grew and developed faster with the help of higher-quality food and that tadpoles differed in their stoichiometric (and life history) response to temperature changes depending on region of origin (probably due to different temperature optima). There was no evidence that higher growth rates mediated the positive effect of temperature on tadpole P content. On the contrary, the covariate growth rate was negatively connected with tadpole P content (refuting the growth rate hypothesis). Lastly, tadpole P content was not related to body size, but tadpole C content was higher in larger tadpoles, probably due to increased fat storage. 5. We conclude that temperature had a strong effect on tadpole life history, nutrient demand and stoichiometry and that this effect depended on the evolved life history. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

The nutritional quality of foods carrying health-related claims in Germany, The Netherlands, Spain, Slovenia and the United Kingdom

PubMed Central

Kaur, A; Scarborough, P; Hieke, S; Kusar, A; Pravst, I; Raats, M; Rayner, M

2016-01-01

Backgroung/Objectives: Compares the nutritional quality of pre-packaged foods carrying health-related claims with foods that do not carry health-related claims. Subject/Methods: Cross-sectional survey of pre-packaged foods available in Germany, The Netherlands, Spain, Slovenia and the United Kingdom in 2013. A total of 2034 foods were randomly sampled from three food store types (a supermarket, a neighbourhood store and a discounter). Nutritional information was taken from nutrient declarations present on food labels and assessed through a comparison of mean levels, regression analyses and the application of a nutrient profile model currently used to regulate health claims in Australia and New Zealand (Food Standards Australia New Zealand's Nutrient Profiling Scoring Criterion, FSANZ NPSC). Results: Foods carrying health claims had, on average, lower levels, per 100 g, of the following nutrients, energy—29.3 kcal (P<0.05), protein—1.2 g (P<0.01), total sugars—3.1 g (P<0.05), saturated fat—2.4 g (P<0.001), and sodium—842 mg (P<0.001), and higher levels of fibre—0.8 g (P<0.001). A similar pattern was observed for foods carrying nutrition claims. Forty-three percent (confidence interval (CI) 41%, 45%) of foods passed the FSANZ NPSC, with foods carrying health claims more likely to pass (70%, CI 64%, 76%) than foods carrying nutrition claims (61%, CI 57%, 66%) or foods that did not carry either type of claim (36%, CI 34%, 38%). Conclusions: Foods carrying health-related claims have marginally better nutrition profiles than those that do not carry claims; these differences would be increased if the FSANZ NPSC was used to regulate health-related claims. It is unclear whether these relatively small differences have significant impacts on health. PMID:27406158

Direct and indirect effects of vertical mixing, nutrients and ultraviolet radiation on the bacterioplankton metabolism in high-mountain lakes from southern Europe

NASA Astrophysics Data System (ADS)

Durán, C.; Medina-Sánchez, J. M.; Herrera, G.; Villar-Argaiz, M.; Villafañe, V. E.; Helbling, E. W.; Carrillo, P.

2014-05-01

As a consequence of global change, modifications in the interaction among abiotic stressors on aquatic ecosystems have been predicted. Among other factors, UVR transparency, nutrient inputs and shallower epilimnetic layers could alter the trophic links in the microbial food web. Currently, there are some evidences of higher sensitiveness of aquatic microbial organisms to UVR in opaque lakes. Our aim was to assess the interactive direct and indirect effects of UVR (through the excretion of organic carbon - EOC - by algae), mixing regime and nutrient input on bacterial metabolism. We performed in situ short-term experiments under the following treatments: full sunlight (UVR + PAR, >280 nm) vs. UVR exclusion (PAR only, >400 nm); ambient vs. nutrient addition (phosphorus (P; 30 μg PL-1) and nitrogen (N; up to final N : P molar ratio of 31)); and static vs. mixed regime. The experiments were conducted in three high-mountain lakes of Spain: Enol [LE], Las Yeguas [LY] and La Caldera [LC] which had contrasting UVR transparency characteristics (opaque (LE) vs. clear lakes (LY and LC)). Under ambient nutrient conditions and static regimes, UVR exerted a stimulatory effect on heterotrophic bacterial production (HBP) in the opaque lake but not in the clear ones. Under UVR, vertical mixing and nutrient addition HBP values were lower than under the static and ambient nutrient conditions, and the stimulatory effect that UVR exerted on HBP in the opaque lake disappeared. By contrast, vertical mixing and nutrient addition increased HBP values in the clear lakes, highlighting for a photoinhibitory effect of UVR on HBP. Mixed regime and nutrient addition resulted in negative effects of UVR on HBP more in the opaque than in the clear lakes. Moreover, in the opaque lake, bacterial respiration (BR) increased and EOC did not support the bacterial carbon demand (BCD). In contrast, bacterial metabolic costs did not increase in the clear lakes and the increased nutrient availability even led to higher HBP. Consequently, EOC satisfied BCD in the clear lakes, particularly in the clearest one [LC]. Our results suggest that the higher vulnerability of bacteria to the damaging effects of UVR may be particularly accentuated in the opaque lakes and further recognizes the relevance of light exposure history and biotic interactions on bacterioplankton metabolism when coping with fluctuating radiation and nutrient inputs.

Marine biodiversity–ecosystem functions under uncertain environmental futures

PubMed Central

Bulling, Mark T.; Hicks, Natalie; Murray, Leigh; Paterson, David M.; Raffaelli, Dave; White, Piran C. L.; Solan, Martin

2010-01-01

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity–ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH4-N into the water column, but no effect of species richness on the release of PO4-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty. PMID:20513718

Enhancement of lipid production in two marine microalgae under different levels of nitrogen and phosphorus deficiency.

PubMed

Adenan, Nurul Salma; Yusoff, Fatimah Md; Medipally, Srikanth Reddy; Shariff, M

2016-07-01

Microalgae are important food sources for aquaculture animals. Among the different factors which influence the biochemical composition of microalgae, nitrogen and phosphorus are two of the most important nutrient sources for growth and development. The present study aimed to assess the effects of nitrogen and phosphorus deficiency on lipid production of Chlorella sp. and Chaetoceros calcitrans. Early stationary phase culture of these species were exposed to different stress levels of nitrogen and phosphorus (25%, 50% and 75% of the full NO(3)-N and PO(4)-P concentration in the Conway media), and solvent extraction and gas-liquid chromatography methods were performed for analysis of lipid and fatty acid composition. The results revealed that lipid production in these two species significantly increased (P<0.05) as nitrogen and phosphorus decreased. The fatty acid proportion remained unaffected under nitrogen deficiency, while phosphorus limitation resulted in a decrease of saturated fatty acids and promoted a higher content of omega-3 fatty acids in these species. The protein and carbohydrate levels were also altered under limited nutrients. Therefore, these conditions could be used for enhanced lipid production in microalgae for aquaculture and other industrial applications.

Marine biodiversity-ecosystem functions under uncertain environmental futures.

PubMed

Bulling, Mark T; Hicks, Natalie; Murray, Leigh; Paterson, David M; Raffaelli, Dave; White, Piran C L; Solan, Martin

2010-07-12

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity-ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH(4)-N into the water column, but no effect of species richness on the release of PO(4)-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty.

Foliar nutrient concentrations in balsam fir as affected by soil drainage and methods of slash disposal

Treesearch

Miroslaw M. Czapowskyj

1979-01-01

Foliar nutrient concentrations in young balsam fir growing on strip clearcuts were assessed in relation to soil drainage and three methods of slash disposal. Concentrations of N, K, and Mn were higher for trees growing on well-drained soils than for trees growing on poorly drained soils. Mo concentrations were higher on poorly drained soils and all other measured...

Growth responses of Ulva prolifera to inorganic and organic nutrients: Implications for macroalgal blooms in the southern Yellow Sea, China

PubMed Central

Li, Hongmei; Zhang, Yongyu; Han, Xiurong; Shi, Xiaoyong; Rivkin, Richard B.; Legendre, Louis

2016-01-01

The marine macrophyte Ulva prolifera is the dominant green-tide-forming seaweed in the southern Yellow Sea, China. Here we assessed, in the laboratory, the growth rate and nutrient uptake responses of U. prolifera to different nutrient treatments. The growth rates were enhanced in incubations with added organic and inorganic nitrogen [i.e. nitrate (NO3−), ammonium (NH4+), urea and glycine] and phosphorus [i.e. phosphate (PO43−), adenosine triphosphate (ATP) and glucose 6-phosphate (G-6-P)], relative to the control. The relative growth rates of U. prolifera were higher when enriched with dissolved organic nitrogen (urea and glycine) and phosphorus (ATP and G-6-P) than inorganic nitrogen (NO3− and NH4+) and phosphorus (PO43−). In contrast, the affinity was higher for inorganic than organic nutrients. Field data in the southern Yellow Sea showed significant inverse correlations between macroalgal biomass and dissolved organic nutrients. Our laboratory and field results indicated that organic nutrients such as urea, glycine and ATP, may contribute to the development of macroalgal blooms in the southern Yellow Sea. PMID:27199215

Qualitative and nutritional differences in processing tomatoes grown under commercial organic and conventional production systems.

PubMed

Barrett, D M; Weakley, C; Diaz, J V; Watnik, M

2007-11-01

Organically grown products experienced a doubling in percent penetration of organic sales into retail markets during the period from 1997 to 2003; however, there is still a debate over the perceived quality advantage of organically grown fruits and vegetables. In a study focusing on commercial production of processing tomatoes, samples were analyzed from 4 growers with matched organic and conventional fields. For the 4 growers studied, individual analysis of variance results indicated that tomato juice prepared from organically produced tomatoes on some farms was significantly higher in soluble solids ( degrees Brix), higher in consistency, and titratable acidity, but lower in red color, ascorbic acid, and total phenolics content in the microwaved juice. Results were significantly different among specific growers, and this may be attributed to differences in soil type and soil nutrients, tomato cultivar, environmental conditions, or other production-related factors. Higher levels of soluble solids, titratable acidity, and consistency are desirable for the production of tomato paste, in that tomatoes with these attributes may be more flavorful and require less thermal treatment. This has the potential to result both in cost savings from less energy required in paste manufacture and potentially a higher quality product due to less thermal degradation of color, flavor, and nutrients. Future work may involve a larger number of commercial growers and correlation to controlled university research plots.

Aspen Increase Soil Moisture, Nutrients, Organic Matter and Respiration in Rocky Mountain Forest Communities

PubMed Central

Buck, Joshua R.; St. Clair, Samuel B.

2012-01-01

Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO3 and NH4 were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development. PMID:23285012

The "isohydric trap": a proposed feedback between water shortage, stomatal regulation and nutrient acquisition drives differential growth and survival of European pines under climatic dryness.

PubMed

Salazar-Tortosa, D; Castro, J; Villar-Salvador, P; Viñegla, B; Matías, L; Michelsen, A; Rubio de Casas, R; Querejeta, J I

2018-05-16

Climatic dryness imposes limitations on vascular plant growth by reducing stomatal conductance, thereby decreasing CO 2 uptake and transpiration. Given that transpiration-driven water flow is required for nutrient uptake, climatic stress-induced nutrient deficit could be a key mechanism for decreased plant performance under prolonged drought. We propose the existence of an "isohydric trap", a dryness-induced detrimental feedback leading to nutrient deficit and stoichiometry imbalance in strict isohydric species. We tested this framework in a common garden experiment with 840 individuals of four ecologically-contrasting European pines (Pinus halepensis, P. nigra, P. sylvestris, and P. uncinata) at a site with high temperature and low soil water availability. We measured growth, survival, photochemical efficiency, stem water potentials, leaf isotopic composition (δ 13 C, δ 18 O), and nutrient concentrations (C, N, P, K, Zn, Cu). After two years, the Mediterranean species Pinus halepensis showed lower δ 18 O and higher δ 13 C values than the other species, indicating higher time-integrated transpiration and water-use efficiency (WUE), along with lower predawn and midday water potentials, higher photochemical efficiency, higher leaf P and K concentrations, more balanced N:P and N:K ratios, and much greater dry-biomass (up to 63-fold) and survival (100%). Conversely, the more mesic mountain pine species showed higher leaf δ 18 O and lower δ 13 C, indicating lower transpiration and WUE, higher water potentials, severe P and K deficiencies and N:P and N:K imbalances, and poorer photochemical efficiency, growth, and survival. These results support our hypothesis that vascular plant species with tight stomatal regulation of transpiration can become trapped in a feedback cycle of nutrient deficit and imbalance that exacerbates the detrimental impacts of climatic dryness on performance. This overlooked feedback mechanism may hamper the ability of isohydric species to respond to ongoing global change, by aggravating the interactive impacts of stoichiometric imbalance and water stress caused by anthropogenic N deposition and hotter droughts, respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Energy and Nutrient Intake From Pizza in the United States

PubMed Central

Nguyen, Binh T.; Dietz, William H.

2015-01-01

BACKGROUND AND OBJECTIVE: Pizza consumption is a top contributor to children’s and adolescents’ caloric intake. The objective of this study was to examine children’s and adolescents’ pizza consumption patterns and its impact on their energy and nutrient intake. METHODS: Twenty-four–hour dietary recall data for children aged 2 to 11 and adolescents aged 12 to 19 were drawn from the 2003–2004, 2005–2006, 2007–2008, and 2009–2010 National Health and Nutrition Examination Survey. We tested changes in consumption patterns, including by race/ethnicity, income, meal occasion, and source. Individual-level fixed effects regression models estimated the impact of pizza consumption on total energy intake (TEI) and intakes of sugar, saturated fat, and sodium. RESULTS: From 2003–2004 to 2009–2010, overall energy intake from pizza declined 25% among children (110 to 83 kcal, P ≤ .05). Among adolescents, although caloric intake from pizza among those who consumed pizza fell (801 to 624 kcal, P ≤ .05), overall pizza intake remained unchanged due to slightly higher pizza consumption prevalence. For children and adolescents, pizza intake fell (P ≤ .05) at dinner time and from fast food. For children and adolescents, respectively, pizza consumption was significantly associated with higher net daily TEI (84 kcal and 230 kcal) and higher intakes of saturated fat (3 g and 5 g) and sodium (134 mg and 484 mg) but not sugar intake, and such affects generally did not differ by sociodemographic characteristics. Pizza consumption as a snack or from fast-food restaurants had the greatest adverse impact on TEI. CONCLUSIONS: The adverse dietary effects of pizza consumption found in this study suggest that its consumption should be curbed and its nutrient content improved. PMID:25601973

Energy and nutrient intake from pizza in the United States.

PubMed

Powell, Lisa M; Nguyen, Binh T; Dietz, William H

2015-02-01

Pizza consumption is a top contributor to children's and adolescents' caloric intake. The objective of this study was to examine children's and adolescents' pizza consumption patterns and its impact on their energy and nutrient intake. Twenty-four-hour dietary recall data for children aged 2 to 11 and adolescents aged 12 to 19 were drawn from the 2003-2004, 2005-2006, 2007-2008, and 2009-2010 National Health and Nutrition Examination Survey. We tested changes in consumption patterns, including by race/ethnicity, income, meal occasion, and source. Individual-level fixed effects regression models estimated the impact of pizza consumption on total energy intake (TEI) and intakes of sugar, saturated fat, and sodium. From 2003-2004 to 2009-2010, overall energy intake from pizza declined 25% among children (110 to 83 kcal, P ≤ .05). Among adolescents, although caloric intake from pizza among those who consumed pizza fell (801 to 624 kcal, P ≤ .05), overall pizza intake remained unchanged due to slightly higher pizza consumption prevalence. For children and adolescents, pizza intake fell (P ≤ .05) at dinner time and from fast food. For children and adolescents, respectively, pizza consumption was significantly associated with higher net daily TEI (84 kcal and 230 kcal) and higher intakes of saturated fat (3 g and 5 g) and sodium (134 mg and 484 mg) but not sugar intake, and such affects generally did not differ by sociodemographic characteristics. Pizza consumption as a snack or from fast-food restaurants had the greatest adverse impact on TEI. The adverse dietary effects of pizza consumption found in this study suggest that its consumption should be curbed and its nutrient content improved. Copyright © 2015 by the American Academy of Pediatrics.

Linking benthic community structure to terrestrial runoff and upwelling in the coral reefs of northeastern Hainan Island

NASA Astrophysics Data System (ADS)

Li, Xiubao; Wang, Daoru; Huang, Hui; Zhang, Jing; Lian, Jiansheng; Yuan, Xiangcheng; Yang, Jianhui; Zhang, Guoseng

2015-04-01

Near-shore coral reefs in northeastern Hainan Island are close to river mouths and aquaculture ponds, and also located at the center of the Qiongdong Upwelling (QDU). However, it is still unclear how terrestrial runoff and upwelling influence the community composition and spatial distribution of the benthos. During three cruises in 2010 and 2011 in Wenchang, northeastern Hainan Island, we determined a subset of environmental parameters in seawater (e.g. temperature, salinity, DO, dissolved inorganic nutrient (DIN), turbidity and transparency) and macroalgal δ15N and investigated the benthic communities (e.g. live coral cover, coral species richness, juvenile coral density, macroalgal cover and coverage of calcified algae) by video transect and visual census techniques at 10 stations (i.e. 1S-6D). The results showed that the QDU has influenced the reef waters in Wenchang. In 2011, the upwelling started in early May, peaked in July and disappeared in September and most upwelling events lasted for 1-2 weeks between May and July. The results also demonstrated that the reef water was nutrient enriched. Stations close to the river mouth and aquaculture ponds had higher levels of DIN and a higher percentage of ammonia in DIN, and there was consistently lower live coral cover, juvenile coral density and higher macroalgal cover. At some stations in this study, live coral cover was negatively correlated with macroalgal cover (i.e. 2S-6D). Live coral cover, species richness, and juvenile coral density all increased with the distance away from the river outlet and decreased with the rise of DIN. These results suggest that terrestrial runoff and upwelling stimulate nutrient enrichment, and that overgrowing macroalgae has an important influence on the coral communities in northeastern Hainan Island.

Macro-grazer herbivory regulates seagrass response to pulse and press nutrient loading.

PubMed

Ravaglioli, Chiara; Capocchi, Antonella; Fontanini, Debora; Mori, Giovanna; Nuccio, Caterina; Bulleri, Fabio

2018-05-01

Coastal ecosystems are exposed to multiple stressors. Predicting their outcomes is complicated by variations in their temporal regimes. Here, by means of a 16-month experiment, we investigated tolerance and resistance traits of Posidonia oceanica to herbivore damage under different regimes of nutrient loading. Chronic and pulse nutrient supply were combined with simulated fish herbivory, treated as a pulse stressor. At ambient nutrient levels, P. oceanica could cope with severe herbivory, likely through an increase in photosynthetic activity. Elevated nutrient levels, regardless of the temporal regime, negatively affected plant growth and increased leaf nutritional quality. This ultimately resulted in a reduction of plant biomass that was particularly severe under chronic fertilization. Our results suggest that both chronic and pulse nutrient loadings increase plant palatability to macro-grazers. Strategies for seagrass management should not be exclusively applied in areas exposed to chronic fertilization since even short-term nutrient pulses could alter seagrass meadows. Copyright © 2018 Elsevier Ltd. All rights reserved.

Scaling of physical constraints at the root-soil interface to macroscopic patterns of nutrient retention in ecosystems.

PubMed

Gerber, Stefan; Brookshire, E N Jack

2014-03-01

Nutrient limitation in terrestrial ecosystems is often accompanied with maintaining a nearly closed vegetation-soil nutrient cycle. The ability to retain nutrients in an ecosystem requires the capacity of the plant-soil system to draw down nutrient levels in soils effectually such that export concentrations in soil solutions remain low. Here we address the physical constraints of plant nutrient uptake that may be limited by the diffusive movement of nutrients in soils, by the uptake at the root/mycorrhizal surface, and from interactions with soil water flow. We derive an analytical framework of soil nutrient transport and uptake and predict levels of plant available nutrient concentration and residence time. Our results, which we evaluate for nitrogen, show that the physical environment permits plants to lower soil solute concentration substantially. Our analysis confirms that plant uptake capacities in soils are considerable, such that water movement in soils is generally too small to significantly erode dissolved plant-available nitrogen. Inorganic nitrogen concentrations in headwater streams are congruent with the prediction of our theoretical framework. Our framework offers a physical-based parameterization of nutrient uptake in ecosystem models and has the potential to serve as an important tool toward scaling biogeochemical cycles from individual roots to landscapes.

Sources and transport of sediment, nutrients, and oxygen-demanding substances in the Minnesota River basin, 1989-92

USGS Publications Warehouse

Payne, G.A.

1994-01-01

The Minnesota River, 10 major tributaries, and 21 springs were sampled to determine the sources and transport of sediment, nutrients, and oxygen- demanding substances. The study was part of a four-year assessment of non-point source pollution in the Minnesota River Basin. Runoff from tributary watersheds was identified as the primary source of suspended sediment and nutrients in the Minnesota River mainstem. Suspended-sediment, phosphorus, and nitrate concentrations were elevated in all major tributaries during runoff, but tributaries in the south-central and eastern part of the basin produce the highest annual loading to the mainstem because of higher annual precipitation and runoff in that part of the basin. Particle-size analyses showed that most of the suspended sediment in transport consisted of silt- and clay-size material. Phosphorus enrichment was indicated throughout the mainstem by total phosphorus concentrations that ranged from 0.04 to 0.48 mg/L with a median value of 0.22 mg/L, and an interquartile range of 0.15 to 0.29 mg/L. Nitrate concentrations periodically exceeded drinking water standards in tributaries draining the south-central and eastern part of the basin. Oxygen demand was most elevated during periods of summer low flow. Correlations between levels of biochemical oxygen demand and levels of algal productivity suggest that algal biomass comprises much of the oxygen-demanding material in the mainstem. Transport of sediment, nutrients, and organic carbon within the mainstem was found to be conservative, with nearly all tributary inputs being transported downstream. Uptake and utilization of nitrate and orthophosphorus was indicated during low flow, but at normal and high flow, inputs of these constituents greatly exceeded biological utilization.

Nutrient uptake and growth responses of Virginia pine to elevated atmospheric carbon dioxide. [Pisolithus tinctorius, Pinus virginiana Mill

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luxmoore, R.J.; O'Neill, E.G.; Ells, J.M.

One-year-old Virgina pine (Pinus virginiana Mill.) seedlings with native or Pisolithus tinctorius mycorrhizal associations were grown in pots with soil low in organic matter and in cation exchange capacity and were exposed to one of five atmospheric CO/sub 2/ levels in the range of 340 to 940 ..mu..L/L in open-top field chambers. The mean dry weight of the seedlings increased from 4.4 to 11.0 g/plant during the 122-d exposure period. Significant increases in dry weight and uptake of N, Ca, Al, Fe, Zn, and Sr occurred with CO/sub 2/ enrichment. Greater chemical uptake was associated with greater root weight. Specificmore » absorption rates for chemicals (uptake per gram of root per day) were generally not affected by CO/sub 2/ enrichment. The uptake of P and K was not increased with elevated CO/sub 2/, and these elements showed the greater nutrient-use efficiency (C gain per element uptake). The nutrient-use efficiency for N and Ca was not influenced by atmospheric CO/sub 2/ enrichment. Large increases in Zn uptake at high CO'' suggested an increase in rhizosphere acidification, which may have resulted from the release of protons from the roots, since it was estimated that cation uptake increasingly exceeded anion uptake with CO/sub 2/ enrichment. Potassium, P, and NO/sub 3//sup -/ concentrations in the pot leachate decreased with higher CO/sub 2/ levels, and a similar trend was found for Al and Mg. These results suggest that soil-plant systems may exhibit increased nutrient and chemical retention at elevated atmospheric CO/sub 2/.« less

Elymus repens biomass allocation and acquisition as affected by light and nutrient supply and companion crop competition.

PubMed

Ringselle, Björn; Prieto-Ruiz, Inés; Andersson, Lars; Aronsson, Helena; Bergkvist, Göran

2017-02-01

Competitive crops are a central component of resource-efficient weed control, especially for problematic perennial weeds such as Elymus repens Competition not only reduces total weed biomass, but denial of resources can also change the allocation pattern - potentially away from the underground storage organs that make perennial weeds difficult to control. Thus, the competition mode of crops may be an important component in the design of resource-efficient cropping systems. Our aim was to determine how competition from companion crops with different modes of competition affect E. repens biomass acquisition and allocation and discuss that in relation to how E. repens responds to different levels of light and nutrient supply. Greenhouse experiments were conducted with E. repens growing in interspecific competition with increasing density of perennial ryegrass or red clover, or growing at three levels of both light and nutrient supply. Elymus repens total biomass decreased with increasing biomass of the companion crop and the rate of decrease was higher with red clover than with perennial ryegrass, particularly for E. repens rhizome biomass. A reduced nutrient supply shifted E. repens allocation towards below-ground biomass while a reduced light supply shifted it towards shoot biomass. Red clover caused no change in E. repens allocation pattern, while ryegrass mostly shifted the allocation towards below-ground biomass, but the change was not correlated with ryegrass biomass. The companion crop mode of competition influences both the suppression rate of E. repens biomass acquisition and the likelihood of shifts in E. repens biomass allocation. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Plant Productivity and Characterization of Zeoponic Substrates after Three Successive Crops of Radish (Raphanus sativus L.)

NASA Technical Reports Server (NTRS)

Gruener, J. E.; Ming, Douglas W.; Galindo, C., Jr.; Henderson, K. E.; Golden, D. C.

2007-01-01

The National Aeronautics and Space Administration (NASA) has developed a zeolite-based synthetic substrate, termed zeoponics. The zeoponic substrate (consisting of NH4(-) and K-exchanged clinoptilolite, synthetic apatite, and dolomite) provides all of the plant-essential nutrients through mineral dissolution and ion exchange, with only the addition of water. Previous studies have shown high productivity of wheat in zeoponic substrates; however, no experiments have been conducted on other crops. The objective of this study was to determine the productivity and nutrient uptake of radish (Raphanus sativus L.) grown in zeoponic substrates with three successive crops in the same substrate. Radish was chosen because of its sensitivities to NH4(+). Average fresh weights of edible roots were similar for radish grown in zeoponic substrates watered with deionized H2O (10.97 g/plant) and in potting mix control substrate irrigated with nutrient solution (10.92 g/plant). Average fresh weight production of edible roots for radish grown in same zeoponic substrate increased in yield over time with the lowest yield in the first crop (7.10 g/plant) and highest in the third crop (13.90 g/plant). The Ca plant tissue levels in radishes (1.8-2.9 wt. %) grown in zeoponic substrates are lower than the suggested sufficient range of 3.0-4.5 wt. % Ca; however, the Ca level is highest (2.9 wt. %) in radishes grown in the third crop in the same zeoponic substrates. The higher radish yield in the third crop was attributed to a reduction in an NH4(-) induced Ca deficiency that has been previously described for wheat grown in zeoponic substrates. The P levels in plant tissues of radish grown in the zeoponic substrates ranged from 0.94-1.15 wt. %; which is slightly higher than the sufficient levels of 0.3-0.7 wt. %. With the exception of Ca and P, other macronutrient and micronutrient levels in radish grown in zeoponic substrates were well within the recommended sufficient ranges. After three successive crops of radish growth, the zeoponic substrates had 52% of the original NH4(-)N and 78% of the original K remaining on zeolite exchange sites. Zeoponic substrates are capable of long-term productivity of radishes for space.

Effect of herbicide concentration and organic and inorganic nutrient amendment on the mineralization of mecoprop, 2,4-D and 2,4,5-T in soil and aquifer samples.

PubMed

de Lipthay, Julia R; Sørensen, Sebastian R; Aamand, Jens

2007-07-01

The impact of the herbicide concentration (0.10-10,000 microg kg(-1)) and addition of organic and inorganic nutrients on mecoprop, 2,4-D and 2,4,5-T mineralization in aquifer and soil samples was studied in laboratory experiments. Generally, 2,4-D was most rapidly mineralized followed by mecoprop and 2,4,5-T. A shift from non-growth to growth-linked mineralization kinetics was observed in aquifer sediment with 2,4-D concentrations >0.10 microg kg(-1) and mecoprop concentrations >10.0 microg kg(-1). The shift was apparent at higher herbicide concentrations in soil coinciding with a lower bioavailable fraction and a higher herbicide sorption to soil. Herbicide addition did not affect the bacterial density, although 2,4-D and mecoprop applied at 10,000 microg kg(-1) stimulated growth of specific degraders. Generally, nutrient amendments did not stimulate mineralization at the lowest herbicide concentrations. In contrast, the mineralization rate of higher herbicide concentrations was significantly stimulated by the amendment of inorganic nutrients.

Predicting nutrient and sediment loadings to streams from landscape metrics: A multiple watershed study from the United States Mid-Atlantic Region

Treesearch

K. Bruce Jones; Anne C. Neale; Malisha S. Nash; Rick D. van Remortel; James D. Wickham; Kurt H. Riitters; Robert V. O' Neill

2001-01-01

There has been an increasing interest in evaluating the relative condition or health of water resources at regional and national scales. Of particular interest is an ability to identify those areas where surface and ground waters have the greatest potential for high levels of nutrient and sediment loadings. High levels of nutrient and sediment loadings can have adverse...

Species traits and environmental conditions govern the relationship between biodiversity effects across trophic levels

USGS Publications Warehouse

Spooner, D.E.; Vaughn, C.C.; Galbraith, H.S.

2012-01-01

Changing environments can have divergent effects on biodiversity-ecosystem function relationships at alternating trophic levels. Freshwater mussels fertilize stream foodwebs through nutrient excretion, and mussel species-specific excretion rates depend on environmental conditions. We asked how differences in mussel diversity in varying environments influence the dynamics between primary producers and consumers. We conducted field experiments manipulating mussel richness under summer (low flow, high temperature) and fall (moderate flow and temperature) conditions, measured nutrient limitation, algal biomass and grazing chironomid abundance, and analyzed the data with non-transgressive overyielding and tripartite biodiversity partitioning analyses. Algal biomass and chironomid abundance were best explained by trait-independent complementarity among mussel species, but the relationship between biodiversity effects across trophic levels (algae and grazers) depended on seasonal differences in mussel species' trait expression (nutrient excretion and activity level). Both species identity and overall diversity effects were related to the magnitude of nutrient limitation. Our results demonstrate that biodiversity of a resource-provisioning (nutrients and habitat) group of species influences foodweb dynamics and that understanding species traits and environmental context are important for interpreting biodiversity experiments. ?? 2011 Springer-Verlag.

Nutrients removal and substrate enzyme activities in vertical subsurface flow constructed wetlands for mariculture wastewater treatment: Effects of ammonia nitrogen loading rates and salinity levels.

PubMed

Li, Meng; Liang, Zhenlin; Callier, Myriam D; Roque d'orbcastel, Emmanuelle; Sun, Guoxiang; Ma, Xiaona; Li, Xian; Wang, Shunkui; Liu, Ying; Song, Xiefa

2018-06-01

This study aims to investigate the effects of ammonia nitrogen loading rates and salinity levels on nutrients removal rates and substrate enzyme activities of constructed wetland (CW) microcosms planted with Salicornia bigelovii treating mariculture wastewater. Activities of urease (UA), dehydrogenase (DA), protease (PrA) and phosphatase (PA) were considered. Using principal component analysis (PCA), nutrient removal index (NRI) and enzyme activity index (EAI) were developed to evaluate the effects. The results revealed that increasing ammonia nitrogen loading rates had positive effects on nitrogen removal rates (i.e. NH 4 -N and DIN) and enhanced substrate enzyme activities. Compared with low salinity (i.e. 15 and 22), high salinity levels (i.e. 29 and 36) enhanced nutrients removal rates, DA and UA, but weaken PA and PrA. In conclusion, CW microcosms with Salicornia bigelovii can be used for the removal of nutrients under a range of ammonia nitrogen loadings and high salinity levels. Copyright © 2018 Elsevier Ltd. All rights reserved.

Consumption of various forms of apples is associated with a better nutrient intake and improved nutrient adequacy in diets of children: National Health and Nutrition Examination Survey 2003–2010

PubMed Central

Nicklas, Theresa A.; O'Neil, Carol E.; Fulgoni, Victor L.

2015-01-01

Background Consumption of fruit has been associated with a variety of health benefits, yet, 75% of children have usual intakes of total fruit below minimum recommended amounts. Apples are the second most commonly consumed fruit in the United States; however, no studies have examined the impact of apple consumption on nutrient intake and adequacy in children's diets. Objective The purpose of this study is to examine the association between apple (various forms) consumption with nutrient intake and nutrient adequacy in a nationally representative sample of children. Design Participants were children aged 2–18 years (n=13,339), from the National Health and Nutrition Examination Survey 2003–2010. Least square means of total energy and nutrient intake, and the percentage of the population below the estimated average requirement (EAR) or above the adequate intake (AI) among apple consumers and non-consumers were examined. Results Consumers of total apple products had higher (p<0.01) total intakes of fiber, magnesium, and potassium and lower intakes of total fat, saturated fatty acids, monounsaturated fatty acid, and sodium than non-consumers. Apple consumers had higher (p<0.01) total sugar intake, but lower intake of added sugars compared to non-consumers. A lower (p<0.01) percentage of apple consumers were below the EAR for 13 of the 16 nutrients studied. Apple consumers had approximately a 10 percentage unit difference below the EAR for calcium and magnesium, and vitamins A, C, D, and E, than non-consumers. The percentage above the AI for fiber was significantly (p<0.0001) higher among total apple consumers (6.24±0.45 g) compared to non-consumers (0.57±0.07 g). The results were similar for individual apple products (i.e. apple juice, applesauce, and whole apples). Conclusion Consumption of any forms of apples provided valuable nutrients in the diets of children. PMID:26445211

Consumption of various forms of apples is associated with a better nutrient intake and improved nutrient adequacy in diets of children: National Health and Nutrition Examination Survey 2003-2010.

PubMed

Nicklas, Theresa A; O'Neil, Carol E; Fulgoni, Victor L

2015-01-01

Consumption of fruit has been associated with a variety of health benefits, yet, 75% of children have usual intakes of total fruit below minimum recommended amounts. Apples are the second most commonly consumed fruit in the United States; however, no studies have examined the impact of apple consumption on nutrient intake and adequacy in children's diets. The purpose of this study is to examine the association between apple (various forms) consumption with nutrient intake and nutrient adequacy in a nationally representative sample of children. Participants were children aged 2-18 years (n=13,339), from the National Health and Nutrition Examination Survey 2003-2010. Least square means of total energy and nutrient intake, and the percentage of the population below the estimated average requirement (EAR) or above the adequate intake (AI) among apple consumers and non-consumers were examined. Consumers of total apple products had higher (p<0.01) total intakes of fiber, magnesium, and potassium and lower intakes of total fat, saturated fatty acids, monounsaturated fatty acid, and sodium than non-consumers. Apple consumers had higher (p<0.01) total sugar intake, but lower intake of added sugars compared to non-consumers. A lower (p<0.01) percentage of apple consumers were below the EAR for 13 of the 16 nutrients studied. Apple consumers had approximately a 10 percentage unit difference below the EAR for calcium and magnesium, and vitamins A, C, D, and E, than non-consumers. The percentage above the AI for fiber was significantly (p<0.0001) higher among total apple consumers (6.24±0.45 g) compared to non-consumers (0.57±0.07 g). The results were similar for individual apple products (i.e. apple juice, applesauce, and whole apples). Consumption of any forms of apples provided valuable nutrients in the diets of children.

Seasonal Assessment of the Relationship between the Discharge of the Trinity River and the Trinity Bay Ecosystem.

DTIC Science & Technology

1973-08-25

that the shad and anchovy 118 populations are primarily dependent on plankton for food, which means that the higher salinities necessary for increased...therefore, regulating salinity levels for shrimp would increase both the shrimp fishery and other fish populations dependent on shrimp, as well...Bay ecosystem is that the bay is dependent upon the river for nutrients Gnd for maintenance of the salinity gradient. Odum, ’ ;.. (1963), Copeland

Interactive Effect of UVR and Phosphorus on the Coastal Phytoplankton Community of the Western Mediterranean Sea: Unravelling Eco-Physiological Mechanisms

PubMed Central

Carrillo, Presentación; Medina-Sánchez, Juan M.; Herrera, Guillermo; Durán, Cristina; Segovia, María; Cortés, Dolores; Salles, Soluna; Korbee, Nathalie; L. Figueroa, Félix; Mercado, Jesús M.

2015-01-01

Some of the most important effects of global change on coastal marine systems include increasing nutrient inputs and higher levels of ultraviolet radiation (UVR, 280–400 nm), which could affect primary producers, a key trophic link to the functioning of marine food webs. However, interactive effects of both factors on the phytoplankton community have not been assessed for the Mediterranean Sea. An in situ factorial experiment, with two levels of ultraviolet solar radiation (UVR+PAR vs. PAR) and nutrients (control vs. P-enriched), was performed to evaluate single and UVR×P effects on metabolic, enzymatic, stoichiometric and structural phytoplanktonic variables. While most phytoplankton variables were not affected by UVR, dissolved phosphatase (APAEX) and algal P content increased in the presence of UVR, which was interpreted as an acclimation mechanism of algae to oligotrophic marine waters. Synergistic UVR×P interactive effects were positive on photosynthetic variables (i.e., maximal electron transport rate, ETRmax), but negative on primary production and phytoplankton biomass because the pulse of P unmasked the inhibitory effect of UVR. This unmasking effect might be related to greater photodamage caused by an excess of electron flux after a P pulse (higher ETRmax) without an efficient release of carbon as the mechanism to dissipate the reducing power of photosynthetic electron transport. PMID:26599583

Influence of seasonal variation on the hydro-biogeochemical characteristics of two upland lakes in the Southeastern Amazon, Brazil.

PubMed

Sahoo, Prafulla K; Guimarães, José T F; Souza-Filho, Pedro W M; Silva, Marcio S DA; Silva, Renato O; Pessim, Gustavo; Moraes, Bergson C DE; Pessoa, Paulo F P; Rodrigues, Tarcísio M; Costa, Marlene F DA; Dall'agnol, Roberto

2016-01-01

Limnological characteristics of the Violão and Amendoim lakes, in the Serra dos Carajás, Amazon, were studied interannually (2013-2014). Climate data indicate anomalous conditions during the 2013 rainy period with higher rainfall and lower temperature in the beginning (November). Lake levels were influenced after the first and second hour of each rainfall, which showed a strong synchronization between seasonal fluctuation of lake levels and local weather patterns. Based on the water quality, both lakes are classified as classes "1" and "2" in the CONAMA (Conselho Nacional do Meio Ambiente) scheme and as "excellent" to "good" in the WQI (Water Quality Index) categories. However, the limnology is distinctly different between the lakes and seasons. Higher trophic state and phytoplankton productivity were observed mainly during the rainy period in Violão Lake compared to Amendoim Lake. This may be due to deposition of leached nutrients in the former, mainly total phosphorus (TP), which was probably derived from mafic soils and guano. This is consistent with the significant positive correlation between Chlorophyll-a and TP at the end of the rainy period (March-April), whereas this was not observed in the beginning (November). This could possibly be a consequence of the more intense cloud cover, and unusual high rainfall that limits nutrient availability.

Does the stoichiometric carbon:phosphorus knife edge apply for predaceous copepods?

PubMed

Laspoumaderes, Cecilia; Modenutti, Beatriz; Elser, James J; Balseiro, Esteban

2015-06-01

Recent work has indicated that stoichiometric food quality in terms of the carbon:phosphorus (C:P) ratio affects consumers whether the imbalance involves a deficit or an excess of nutrients; hence, organisms exist on a "stoichiometric knife edge". While previous studies have focused primarily on autotroph-herbivore trophic transfer, nutritional imbalances may also affect the interactions between species at higher trophic levels. Since the foods of carnivores are normally stoichiometrically similar to the body compositions of those carnivores, they may be more severely affected than herbivores if imbalances become pronounced. We analysed the response of the predatory copepod Parabroteas sarsi to monospecific diet treatments consisting of high and low C:P prey items. These dietary treatments strongly affected the predator's elemental composition and growth, although prey selection, excretion, egestion, and respiration rates were not affected. We suggest that, due to their low threshold elemental ratio and a narrow C:P stoichiometric knife edge, these predators are highly vulnerable to stoichiometric imbalances, whether an excess or a deficit of nutrients is involved. Our results demonstrating this high sensitivity to prey C:P ratio show that the stoichiometric knife edge may apply to not only herbivores but also higher trophic levels. Thus, predators such as P. sarsi, with a much narrower range of food quality, may also be strongly affected by fluctuations in the quality of their prey, with negative consequences for their secondary production.

Effects of abiotic factors on ecosystem health of Taihu Lake, China based on eco-exergy theory

NASA Astrophysics Data System (ADS)

Wang, Ce; Bi, Jun; Fath, Brian D.

2017-02-01

A lake ecosystem is continuously exposed to environmental stressors with non-linear interrelationships between abiotic factors and aquatic organisms. Ecosystem health depicts the capacity of system to respond to external perturbations and still maintain structure and function. In this study, we explored the effects of abiotic factors on ecosystem health of Taihu Lake in 2013, China from a system-level perspective. Spatiotemporal heterogeneities of eco-exergy and specific eco-exergy served as thermodynamic indicators to represent ecosystem health in the lake. The results showed the plankton community appeared more energetic in May, and relatively healthy in Gonghu Bay with both higher eco-exergy and specific eco-exergy; a eutrophic state was likely discovered in Zhushan Bay with higher eco-exergy but lower specific eco-exergy. Gradient Boosting Machine (GBM) approach was used to explain the non-linear relationships between two indicators and abiotic factors. This analysis revealed water temperature, inorganic nutrients, and total suspended solids greatly contributed to the two indicators that increased. However, pH rise driven by inorganic carbon played an important role in undermining ecosystem health, particularly when pH was higher than 8.2. This implies that climate change with rising CO2 concentrations has the potential to aggravate eutrophication in Taihu Lake where high nutrient loads are maintained.

Effects of abiotic factors on ecosystem health of Taihu Lake, China based on eco-exergy theory

PubMed Central

Wang, Ce; Bi, Jun; Fath, Brian D.

2017-01-01

A lake ecosystem is continuously exposed to environmental stressors with non-linear interrelationships between abiotic factors and aquatic organisms. Ecosystem health depicts the capacity of system to respond to external perturbations and still maintain structure and function. In this study, we explored the effects of abiotic factors on ecosystem health of Taihu Lake in 2013, China from a system-level perspective. Spatiotemporal heterogeneities of eco-exergy and specific eco-exergy served as thermodynamic indicators to represent ecosystem health in the lake. The results showed the plankton community appeared more energetic in May, and relatively healthy in Gonghu Bay with both higher eco-exergy and specific eco-exergy; a eutrophic state was likely discovered in Zhushan Bay with higher eco-exergy but lower specific eco-exergy. Gradient Boosting Machine (GBM) approach was used to explain the non-linear relationships between two indicators and abiotic factors. This analysis revealed water temperature, inorganic nutrients, and total suspended solids greatly contributed to the two indicators that increased. However, pH rise driven by inorganic carbon played an important role in undermining ecosystem health, particularly when pH was higher than 8.2. This implies that climate change with rising CO2 concentrations has the potential to aggravate eutrophication in Taihu Lake where high nutrient loads are maintained. PMID:28220835

Eutrophication and Warming Boost Cyanobacterial Biomass and Microcystins.

PubMed

Lürling, Miquel; van Oosterhout, Frank; Faassen, Elisabeth

2017-02-11

Eutrophication and warming are key drivers of cyanobacterial blooms, but their combined effects on microcystin (MC) concentrations are less studied. We tested the hypothesis that warming promotes cyanobacterial abundance in a natural plankton community and that eutrophication enhances cyanobacterial biomass and MC concentrations. We incubated natural seston from a eutrophic pond under normal, high, and extreme temperatures (i.e., 20, 25, and 30 °C) with and without additional nutrients added (eutrophication) mimicking a pulse as could be expected from projected summer storms under climate change. Eutrophication increased algal- and cyanobacterial biomass by 26 and 8 times, respectively, and led to 24 times higher MC concentrations. This effect was augmented with higher temperatures leading to 45 times higher MC concentrations at 25 °C, with 11 times more cyanobacterial chlorophyll- a and 25 times more eukaryote algal chlorophyll- a . At 30 °C, MC concentrations were 42 times higher, with cyanobacterial chlorophyll- a being 17 times and eukaryote algal chlorophyll- a being 24 times higher. In contrast, warming alone did not yield more cyanobacteria or MCs, because the in situ community had already depleted the available nutrient pool. MC per potential MC producing cell declined at higher temperatures under nutrient enrichments, which was confirmed by a controlled experiment with two laboratory strains of Microcystis aeruginosa. Nevertheless, MC concentrations were much higher at the increased temperature and nutrient treatment than under warming alone due to strongly promoted biomass, lifting N-imitation and promotion of potential MC producers like Microcystis . This study exemplifies the vulnerability of eutrophic urban waters to predicted future summer climate change effects that might aggravate cyanobacterial nuisance.

Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

NASA Astrophysics Data System (ADS)

Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

2014-01-01

Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006-2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43-. High riverine concentrations of nitrate mainly originated from agricultural fertilizer inputs. The DIN : PO43- ratios ranged from 37 to 1063, suggesting preferential depletion of PO43- relative to nitrogen in rivers. Chemical weathering in the drainage area might explain the high levels of dissolved silicate. Aquaculture ponds contained high concentrations of NH4+ and dissolved organic nitrogen. The particulate phosphorus concentrations in the study area were lower than those reported for estuaries worldwide. The particulate silicate levels in rivers and lagoons were lower than the global average level. Nutrient biogeochemistry in coastal areas was affected by human activities (e.g., aquaculture, agriculture), and by natural phenomena including typhoons. The nutrient concentrations in coastal waters were low because of dispersion of land-derived nutrients in the sea. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes are magnified by estuarine processes (e.g., regeneration, desorption) in estuaries and Laoyehai Lagoon, but not in Xiaohai Lagoon. Riverine and groundwater inputs were the major sources of nutrients to Xiaohai and Laoyehai lagoons, respectively, and riverine inputs and aquaculture effluents were the major sources for the eastern coast of Hainan Island. Nutrient inputs to the coastal ecosystem increased with typhoon-induced runoff of rainwater, elucidating the important influence of typhoons on small tropical rivers.

Effects of heat stress on the gene expression of nutrient transporters in the jejunum of broiler chickens ( Gallus gallus domesticus)

NASA Astrophysics Data System (ADS)

Sun, Xiaolei; Zhang, Haichao; Sheikhahmadi, Ardashir; Wang, Yufeng; Jiao, Hongchao; Lin, Hai; Song, Zhigang

2015-02-01

In broiler chickens, heat stress disrupts nutrient digestion and absorption. However, the underlying molecular mechanism is not clearly understood. Hence, to investigate the effects of high ambient temperatures on the expression levels of nutrient transporters in the jejunum of broiler chickens, seventy-two 35-day-old male broiler chickens with similar body weights were randomly allocated into two groups: control (24 ± 1 °C) and heat-stressed (32 ± 1 °C). The chickens in the heat-stressed group were exposed to 10 h of heat daily from 08:00 to 18:00 and then raised at 24 ± 1 °C. The rectal temperature and feed intake of the chickens were recorded daily. After 7 days, nine chickens per group were sacrificed by exsanguination, and the jejunum was collected. The results show that heat exposure significantly decreased the feed intake and increased the rectal temperature of the broiler chickens. The plasma concentrations of uric acid and triglyceride significantly increased and decreased, respectively, in the heat-stressed group. No significant differences in the levels of plasma glucose, total amino acids, and very low-density lipoprotein were observed between the heat-stressed and control groups. However, the plasma concentration of glucose tended to be higher ( P = 0.09) in the heat-stressed group than in the control group. Heat exposure did not significantly affect the mRNA levels of Na+-dependent glucose transporter 1 and amino acid transporters y + LAT1, CAT1, r-BAT, and PePT-1. However, the expression levels of GLUT-2, FABP1, and CD36 were significantly decreased by heat exposure. The results of this study provide new insights into the mechanisms by which heat stress affects nutrient absorption in broiler chickens. Our findings suggest that periodic heat exposure might alter the jejunal glucose and lipid transport rather than amino acid transport. However, intestinal epithelial damage and cell loss should be considered when interpreting the effects of heat stress on the expression of intestinal transporters.

Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians

PubMed Central

Elorinne, Anna-Liisa; Alfthan, Georg; Erlund, Iris; Kivimäki, Hanna; Paju, Annukka; Salminen, Irma; Turpeinen, Ursula; Voutilainen, Sari; Laakso, Juha

2016-01-01

Background Vegetarian and vegan diets have become more popular among adolescents and young adults. However, few studies have investigated the nutritional status of vegans, who may be at risk of nutritional deficiencies. Objective To compare dietary intake and nutritional status of Finnish long-term vegans and non-vegetarians. Methods Dietary intake and supplement use were estimated using three-day dietary records. Nutritional status was assessed by measuring biomarkers in plasma, serum, and urine samples. Vegans’ (n = 22) data was compared with those of sex- and age-matched non-vegetarians (n = 19). Results All vegans adhered strictly to their diet; however, individual variability was marked in food consumption and supplementation habits. Dietary intakes of key nutrients, vitamins B12 and D, were lower (P < 0.001) in vegans than in non-vegetarians. Nutritional biomarker measurements showed lower concentrations of serum 25-hydroxyvitamin D3 (25(OH)D3), iodine and selenium (corrected for multiple comparisons, P < 0.001), Vegans showed more favorable fatty acid profiles (P < 0.001) as well as much higher concentrations of polyphenols such as genistein and daidzein (P < 0.001). Eicosapentaenoic acid proportions in vegans were higher than expected. The median concentration of iodine in urine was below the recommended levels in both groups. Conclusions Long-term consumption of a vegan diet was associated with some favorable laboratory measures but also with lowered concentrations of key nutrients compared to reference values. This study highlights the need for nutritional guidance to vegans. PMID:26840251

Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians.

PubMed

Elorinne, Anna-Liisa; Alfthan, Georg; Erlund, Iris; Kivimäki, Hanna; Paju, Annukka; Salminen, Irma; Turpeinen, Ursula; Voutilainen, Sari; Laakso, Juha

2016-01-01

Vegetarian and vegan diets have become more popular among adolescents and young adults. However, few studies have investigated the nutritional status of vegans, who may be at risk of nutritional deficiencies. To compare dietary intake and nutritional status of Finnish long-term vegans and non-vegetarians. Dietary intake and supplement use were estimated using three-day dietary records. Nutritional status was assessed by measuring biomarkers in plasma, serum, and urine samples. Vegans' (n = 22) data was compared with those of sex- and age-matched non-vegetarians (n = 19). All vegans adhered strictly to their diet; however, individual variability was marked in food consumption and supplementation habits. Dietary intakes of key nutrients, vitamins B12 and D, were lower (P < 0.001) in vegans than in non-vegetarians. Nutritional biomarker measurements showed lower concentrations of serum 25-hydroxyvitamin D3 (25(OH)D3), iodine and selenium (corrected for multiple comparisons, P < 0.001), Vegans showed more favorable fatty acid profiles (P < 0.001) as well as much higher concentrations of polyphenols such as genistein and daidzein (P < 0.001). Eicosapentaenoic acid proportions in vegans were higher than expected. The median concentration of iodine in urine was below the recommended levels in both groups. Long-term consumption of a vegan diet was associated with some favorable laboratory measures but also with lowered concentrations of key nutrients compared to reference values. This study highlights the need for nutritional guidance to vegans.

Urban trees reduce nutrient leaching to groundwater.

PubMed

Nidzgorski, Daniel A; Hobbie, Sarah E

2016-07-01

Many urban waterways suffer from excess nitrogen (N) and phosphorus (P), feeding algal blooms, which cause lower water clarity and oxygen levels, bad odor and taste, and the loss of desirable species. Nutrient movement from land to water is likely to be influenced by urban vegetation, but there are few empirical studies addressing this. In this study, we examined whether or not urban trees can reduce nutrient leaching to groundwater, an important nutrient export pathway that has received less attention than stormwater. We characterized leaching beneath 33 trees of 14 species, and seven open turfgrass areas, across three city parks in Saint Paul, Minnesota, USA. We installed lysimeters at 60 cm depth to collect soil water approximately biweekly from July 2011 through October 2013, except during winter and drought periods, measured dissolved organic carbon (C), N, and P in soil water, and modeled water fluxes using the BROOK90 hydrologic model. We also measured soil nutrient pools (bulk C and N, KCl-extractable inorganic N, Brays-P), tree tissue nutrient concentrations (C, N, and P of green leaves, leaf litter, and roots), and canopy size parameters (leaf biomass, leaf area index) to explore correlations with nutrient leaching. Trees had similar or lower N leaching than turfgrass in 2012 but higher N leaching in 2013; trees reduced P leaching compared with turfgrass in both 2012 and 2013, with lower leaching under deciduous than evergreen trees. Scaling up our measurements to an urban subwatershed of the Mississippi River (~17 400 ha, containing ~1.5 million trees), we estimated that trees reduced P leaching to groundwater by 533 kg in 2012 (0.031 kg/ha or 3.1 kg/km 2 ) and 1201 kg in 2013 (0.069 kg/ha or 6.9 kg/km 2 ). Removing these same amounts of P using stormwater infrastructure would cost $2.2 million and $5.0 million per year (2012 and 2013 removal amounts, respectively). © 2016 by the Ecological Society of America.

Energy and Nutrient Intakes: Findings from the Malaysian Adult Nutrition Survey (MANS).

PubMed

Mirnalini, K; Zalilah, M S; Safiah, M Y; Tahir, A; Siti Haslinda, M D; Siti Rohana, D; Khairul Zarina, M Y; Mohd Hasyami, S; Normah, H

2008-03-01

Nutrition surveys based on a representative sample of the Malaysian adult population have hitherto not been reported. In 2003, the Ministry of Health, Malaysia, conducted the Malaysian Adult Nutrition Survey (MANS), the first and largest nutrition survey in the country which aimed to provide detailed quantitative information on nutritional status, food and nutrient intakes, and physical activity pattern on a nationwide representative sample of adult subjects between the ages of 18 and 59 years. The survey covered four zones in Peninsular Malaysia (Central, Southern, Northern and East Coast), Sabah and Sarawak. This paper presents the mean and selected percentiles of energy and nutrient intake of 6886 subjects by selected demographic and socioeconomic characteristics. Energy contributions by macronutrients and dietary adequacy in relation to the Recommended Nutrient Intake for Malaysians are also described. Information on dietary intake was collected by trained nutritionists using a one day 24-hour diet recall. Dietary data were analysed using Nutritionist Pro, a diet analysis software and statistical analysis was carried out using the SPSS ver. 13.0. In most of the demographic and socioeconomic groups, males had higher mean energy (1776 kcal) and nutrient intake and percent achievement of RNI than females (1447 kcal). The proportions of calories derived from macronutrients were within the recommendations for a healthy diet. Intake of micronutrients such as iron, calcium and vitamin A was about 50% of RNI particularly in women. Sodium intake of Malaysians, not reported in earlier studies, is also made available. Under-reporting using the EI/BMR ratio was found in half of the population studied. The present study provides the first national estimates of energy and nutrient intake of the Malaysian adult population. Regular nutrition surveys are needed at the national level to provide valuable information on trends in food and nutrient intake, particularly among age and ethnically diverse subgroups of the population.

Assessment of Nutrient Stability in Space Foods

NASA Technical Reports Server (NTRS)

Zwart, S. R.; Perchonok, M.; Braby, L. A.; Kloeris, V. A.; Smith, S. M.

2009-01-01

Maintaining an intact nutrient supply in the food system flown on spacecraft is a critical issue for mission success and crew health and safety. Early polar expeditions and exploration expeditions by sailing vessels have taught us that a deficiency, or excess, of even a single vitamin in the food supply can be catastrophic. Evidence from ground-based research indicates that some vitamins are destroyed and fatty acids are oxidized (and therefore rendered dangerous or useless) by different types of radiation and by conditions of long-term storage. We hypothesize that radiation and long-term storage in the space-flight environment will affect the stability of vitamins, amino acids, and fatty acids in the space food system. The research objectives of our ongoing stability studies are to determine the stability of water- and fat-soluble vitamins, fatty acids, and amino acids in the space food supply before and after space flight on the International Space Station (ISS). Foods were analyzed after 2 weeks (a flight control), 11, 19, and 28 months of flight. Along with the space-flown foods, ground-based controls matched for time, light, and temperature are analyzed. The flight studies complement planned ground-based studies of the effects of radiation on vitamins, amino acids, and fatty acids. Flight studies are needed because a model based on ground-based data cannot predict all of the effects of the space-flight environment. Flight studies provide a more accurate test system to determine the effects on these nutrients of the temperature, and radiation conditions in the space-flight environment. Ground studies are required to evaluate longer missions and higher radiation levels expected outside low-Earth orbit. In addition to providing information about nutrient stability in space, the results of these studies will help NASA determine if a need exists to develop special packaging that can ensure stability of foods and nutrients in space, or if further studies of nutrient metabolism or nutrient requirements are needed.

Timber-harvest clearcutting and nutrients in the Northeastern United States

Treesearch

K. G. Reinhart

1973-01-01

The effect of ecosystem disturbance on nutrients in the system has been receiving widespread attention. An appraisal of research results in the Northeast indicates that timber-harvest clearcutting has not increased nutrient levels sufficiently to reduce water quality below drinking water standards. Losses of nutrients from clearcuttings in New Hampshire over a 2-year...

Analysis of nutrients in the surface waters of the Georgia-Florida Coastal Plain study unit, 1970-91

USGS Publications Warehouse

Ham, L.K.; Hatzell, H.H.

1996-01-01

During the early phase of the Georgia-Florida National Water Quality Assessment study, existing information on nutrients was compiled and analyzed in order to evaluate the nutrient concentrations within the 61,545 square mile study unit. Evaluation of the nutrient concentrations collected at surface- water sites between October 1, 1970, and September 30,1991, utilized the environmental characteristics of land resource provinces, land use, and nonpoint and point-source discharges within the study unit. Long-term trends were investigated to determine the temporal distribution of nutrient concentrations. In order to determine a level of concern for nutrient concentrations, the U.S. Environmental Protection Agency (USEPA) guidelines were used-(1) for nitrate concentrations, the maximum contaminant level in public-drinking water supplies (10 mg/L); (2) for ammonia concentrations, the chronic exposure of aquatic organisms to un-ionized ammonia (2.1 mg/L); (3) for total-phosphorus concentrations, the recommended concentration in flowing water to discourage excessive growth of aquatic plants (0.1 mg/L); and (4) for kjeldahl concentrations, however, no guidelines were available. For sites within the 10 major river basins, median nutrient concentrations were generally below USEPA guidelines, except for total-phosphorus concentrations where 45 percent of the medians exceeded the guideline. The only median ammonia concentration that exceeded the guideline occurred at the Swift Creek site (3.4 mg/L), in the Suwannee River basin, perhaps due to wastewater discharges. For all sites within the Withlacoochee, Aucilla, and St. Marys River basins, median concentrations of nitrate, ammonia, and total phosphorus were below the USEPA guidelines. Nutrient data at each monitoring site within each major basin were aggregated for comparisons of median nutrient concentrations among major basins. The Ochlockonee and Hillsborough River basins had the highest median nutrient concentrations, the Aucilla River basin had the lowest. Median concentrations of nitrate and ammonia among all major basins were below USEPA guidelines. The median total-phosphorus concentrations for the following river basins exceeded the USEPA guideline-Hillsborough, St. Johns, Suwannee, Ochlockonee, Satilla, Altamaha, and Ogeechee. Although nutrient concentrations within the study unit were low, long-term increasing trends were found in all four nutrients. All 18 study-unit wide nitrate trends had increasing slopes ranging from less than 0.01 to 0.07 (mg/L)/yr. The range in slope for the 13 ammonia trends was -0.03 to 0.01 (mg/L)/yr with 6 increasing trends in the northern part of the study unit. Of the 17 total-phosphorus trends found in the study unit, 10 were found at sites where the median concentration exceeded the USEPA guideline. At these 10 sites, 4 sites had increasing trends with slopes ranging from less than 0.01 to 0.07 (mg/L)/yr, 5 sites had decreasing trends with slopes ranging from -0.01 to -0.24 (mg/L)/yr, and one site showed a seasonal concentration trend. Median nutrient concentrations were significantly different among the four land resource provinces-Southern Piedmont, Southern Coastal Plain, Coastal Flatwoods, and Central Florida Ridge. As a result, nutrient concentrations among basins with similar nutrient inputs but located within different land resource provinces are not expected to be the same due to differences in the combination of factors such as soil permeability, runoff rates, and stream channel slopes. This concept is an important consideration in designing a surface-water quality network within the study area. For the most part, the Coastal Flatwoods showed the lowest median nutrient concentrations and the Southern Coastal Plain had the highest median nutrient concentrations. Lower median nitrate concentrations in surface-water basins were associated with the forest/wetland land-use category and higher median concentrations of nitrate and ammonia with