Input and dispersion of nutrients from the Jeddah Metropolitan Area, Red Sea

Large amounts of waste water are discharged from the Jeddah Metropolitan Area into the Red Sea. Daily loads of total nitrogen (TN) and phosphorus (TP) amount to 6564 kg and 2241 kg, respectively, comprising 83% of dissolved inorganic nitrogen and 33% of dissolved phosphate. Steep gradients prevail nearshore, ranging from 2000 μM TN and 250 μM TP in the hypertrophic city lagoons to 6 μM TN and 0.4 μM TP in the adjacent oligotrophic water. Sewage inputs from Al Khumra, Jeddah's main outfall, cause a widespread but moderate increase in surface nutrient concentrations due to the submerged diffuser. The nutrient pool in the oligotrophic water is dominated by dissolved organic and particulate forms, with nitrate frequently below the detection limit, indicating rapid transformation of inorganic nutrients. N:P ratios, as well as half-saturation constants for phytoplankton growth, suggest that nitrogen is the limiting factor restricting primary production in the area.

Variability of the dissolved nutrient (N, P, Si) concentrations in the Bay of Annaba in relation to the inputs of the Seybouse and Mafragh estuaries

Dissolved inorganic nitrogen (DIN), phosphate (PO₄) and silicic acid (Si(OH)₄) loads from the Seybouse and the Mafragh estuaries into the Bay of Annaba, Algeria, were assessed at three stations of the Bay over three years. The Seybouse inputs had high levels of DIN and PO₄, in contrast to the Mafragh estuary's near-pristine inputs; Si(OH)₄ levels were low in both estuaries. The DIN:PO₄ molar ratios were over 30 in most samples and the Si(OH)4:DIN ratio was less than 0.5 in the Seybouse waters, but nearly balanced in the Mafragh. The specific fluxes of Si-Si(OH)₄ (400-540 kg Si km⁻² yr⁻¹) were comparable in the two catchments, but those of DIN were several-fold higher in the Seybouse (373 kg N km⁻² yr⁻¹). The inner Bay affected by the Seybouse inputs had high levels of all nutrients, while the Mafragh plume and the outer marine station were less enriched.

Comparative analysis of the macronutrient content of Central European ants (Formicidae): implications for ant-eating predators

Prey nutrient quality determines predator performance. Polyphagous predators can address nutritional challenges by targeting prey with specific nutrient composition, but prey-specialised predators (e.g., ant-eaters), must obtain all nutrients from limited array of prey. Analysis of published data on prey specificity of European ant-eating spiders showed that some feed only on one ant genus, while others feed on several genera. Spiders feeding on several ant genera can possibly balance nutrient intake by selecting different ant prey. But monophagous species must extract all prey from a single prey species and can only vary nutrient intake by feeding on specific body parts. Most ant-eating spider species are catching Formica, Lasius and Messor ants, suggesting that these are most profitable ant species. We evaluated the nutritional content of a variety of 16 Central European ant species belonging to 11 genera and four subfamilies. We found that the nutritional composition, namely the amount of carbon, nitrogen and lipids, of European ants is heterogeneous. The largest variation in the amount of carbon and lipids was among ant subfamilies and species, while the largest variation in nitrogen was among ant genera. The largest amount of carbon and nitrogen was typical for Myrmicinae and the largest amount of lipids were typical for Formicinae. Within ants, the relative amounts of lipids were significantly higher in the gaster while the contents of carbon and nitrogen were highest in foreparts. Ant species did not cluster in the ordination space according to their taxonomic relationship or trophic strategy.

Nutrient content in macrophyta collected from southern Baltic Sea beaches in relation to eutrophication and biogas production

One of the signs of eutrophication is the excessive growth of opportunistic macroalgae, a worldwide phenomenon also observed in the Baltic Sea. Mats of macroalgae may drift long distances and accumulate at the seashore, considerably decreasing the recreational value of beaches. The matter accumulating at the shore is treated usually as waste. However, it could be used, for example, as a resource for biogas production. The aim of this work was to verify the hypothesis that collecting of macrophyta accumulating on the beach and potential usage of this material for biogas production will decrease nutrient reserves in the sea to counteract eutrophication and the increase in greenhouse effects. Samples of macrophyta were collected in 2011 and 2012 and analysed for their C, N, and P contents, and degree of degradation (% Chl-a in the sum of chloropigments-a); the results were analysed statistically. The nutrient content was studied in macrophyta accumulating on the beach (Sopot, Gulf of Gdańsk, Poland) and for comparison, macrophyta collected from their habitats in less nutrient polluted area (off the Skåre coast, Trelleborg, Sweden). The nutrient content (N, P) in macrophyta depends primarily on their morphology and only secondarily on environmental nutrient pollution. Collecting the macrophyta biomass accumulating on beaches will not significantly change the eutrophication of the Baltic as a whole; any improvements in this respect are likely to be on a local scale only. Collecting macrophyta removes more nitrogen than phosphorous, so this would decrease the N/P ratio in seawater. This macrophyta biomass is a substantial reserve of renewable energy, which could be utilized with the appropriate technology for biomass collection/preservation and biofuel production as an additive to other carbon-rich biomasses. And the biofuel production should be evaluated not only from the standpoint of economic efficiency but also from the environmental point of view.

Growth, yield and quality attributes of a tropical potato variety (Solanum tuberosum L. cv Kufri chandramukhi) under ambient and elevated carbon dioxide and ozone and their interactions

The present study was designed to study the growth and yield responses of a tropical potato variety (Solanum tuberosum L. cv. Kufri chandramukhi) to different levels of carbon dioxide (382 and 570ppm) and ozone (50 and 70ppb) in combinations using open top chambers (OTCs). Plants were exposed to three ozone levels in combination with ambient CO2 and two ozone levels at elevated CO2. Significant increments in leaf area and total biomass were observed under elevated CO2 in combination with ambient O3 (ECO2+AO3) and elevated O3 (ECO2+EO3), compared to the plants grown under ambient concentrations (ACO2+AO3). Yield measured as fresh weight of potato also increased significantly under ECO2+AO3 and ECO2+EO3. Yield, however, reduced under ambient (ACO2+AO3) and elevated ozone (ACO2+EO3) compared to ACO2 (filtered chamber). Number, fresh and dry weights of tubers of size 35-50mm and>50mm used for direct consumption and industrial purposes, respectively increased maximally under ECO2+AO3. Ambient as well as elevated levels of O3 negatively affected the growth parameters and yield mainly due to reductions in number and weight of tubers of sizes >35mm. The quality of potato tubers was also modified under different treatments. Starch content increased and K, Zn and Fe concentrations decreased under ECO2+AO3 and ECO2+EO3 compared to ACO2+AO3. Starch content reduced under ACO2+AO3 and ACO2+EO3 treatments compared to ACO2. These results clearly suggest that elevated CO2 has provided complete protection to ambient O3 as the potato yield was higher under ECO2+AO3 compared to ACO2. However, ambient CO2 is not enough to protect the plants under ambient O3 levels. Elevated CO2 also provided protection against elevated O3 by improving the yield. Quality of tubers is modified by both CO2 and O3, which have serious implications on human health at present and in future.

Mitigation options to reduce phosphorus losses from the agricultural sector and improve surface water quality: a review

The EU Water Framework Directive (WFD) obliges Member States to improve the quality of surface water and groundwater. The measures implemented to date have reduced the contribution of point sources of pollution, and hence diffuse pollution from agriculture has become more important. In many catchments the water quality remains poor. COST Action 869 was an EU initiative to improve surface water quality that ran from 2006 to 2011, in which 30 countries participated. Its main aim was a scientific evaluation of the suitability and cost-effectiveness of options for reducing nutrient loss from rural areas to surface waters at catchment scale, including the feasibility of the options under different climatic and geographical conditions. This paper gives an overview of various categories of mitigation options in relation to phosphorus (P). The individual measures are described in terms of their mode of action, applicability, effectiveness, time frame, environmental side-effects (N cycling) and cost. In total, 83 measures were evaluated in COST Action 869.

Sand filters for removal of microbes and nutrients from wastewater during a one-year pilot study in a cold temperate climate

Onsite wastewater treatment systems (OWTS) are recognised as potential threats to groundwater or other water environments subject to discharged effluents. In this study, the microbiological and nutrient removal properties of three different pilot-scale sand filters (SFs) were followed over a one-year period. Moreover, a separate phosphorus removal unit was tested for six months. For the best treatment system, the average log removals were 2.2-3.5 for pathogenic human noro- and adenoviruses and 4.3-5.2 and 4.6-5.4 for indicator viruses and bacteria, respectively. The system that effectively removed microbes was also efficient at removing nutrients. However, the poorest treatment system yielded substantially lower removals. The remarkable differences noted between the studied SFs highlights the importance of construction materials and the careful planning of the filters. Moreover, seasonal conditions appear to have a clear effect on purification efficiencies, emphasising the vulnerability of these systems especially in cold climates.

Carbon-nitrogen ratio and in vitro assimilate partitioning patterns in Cyrtanthus guthrieae L

In response to variations in nutritional composition of the growth medium, plants often adjust their metabolism and progressively alter their growth patterns. Carbon (C) and nitrogen (N) constitute the major plant nutritional components influencing plant growth and development patterns. This study examined the growth dynamics and patterns of assimilate partitioning to primary and secondary metabolites in response to varying levels and combinations of C and N in the culture media of Cyrtanthus guthrieae. In vitro callus-derived C. guthrieae plantlets were cultured on solid Murashige and Skoog (MS) media with different concentrations and combinations of C and N. Relative growth rate (RGR) increased proportionally with an increase in C concentrations up to 88 mM sucrose (0.58 d(-1)) beyond which it was hardly influenced by further increases in C. Growth was also significantly favoured in media with high concentrations of N at all C concentrations tested. In C-limited media regimes with growth saturating N conditions, alkaloid accumulation became favoured while polyphenol content increased with an increase in C levels in the medium, a characteristic pattern that appeared to be less influenced by the amount of N. Of the primary metabolites, only proteins showed small significant variations across different media treatments, with starch and soluble sugars increasing proportionately with C levels. In the medium with a high sucrose concentration (175 mM), soluble sugars, amino acids and polyphenols increased markedly, possibly as an adaptive response to the reduced osmotic potential in the media and/or a storage mechanism for excess C and N reserves in the media. From a medicinal perspective, with regard to polyphenolic compounds in C. guthrieae, growth medium conditions that allow for high levels of C pools in the tissue would thus be favourable for the enhanced synthesis of this group of compounds. The medium conditions with 175 mM sucrose and 10.3 mM NH4NO3 gave the highest total polyphenols, flavonoids and proanthocyanidins with a moderate growth rate.

Maximizing the accuracy of field-derived numeric nutrient criteria in water quality regulations

High levels of the nutrients nitrogen and phosphorus can cause unhealthy biological or ecological conditions in surface waters and prevent the attainment of their designated uses. Regulatory agencies are developing numeric criteria for these nutrients in an effort to ensure that the surface waters in their jurisdictions remain healthy and productive, and that water quality standards are met. These criteria are often derived using field measurements that relate nutrient concentrations and other water quality conditions to expected biological responses such as undesirable growth or changes in aquatic plant and animal communities. Ideally, these numeric criteria can be used to accurately "diagnose" ecosystem health and guide management decisions. However, the degree to which numeric nutrient criteria are useful for decision making depends on how accurately they reflect the status or risk of nutrient-related biological impairments. Numeric criteria that have little predictive value are not likely to be useful for managing nutrient concerns. This paper presents information on the role of numeric nutrient criteria as biological health indicators, and the potential benefits of sufficiently accurate criteria for nutrient management. In addition, it describes approaches being proposed or adopted in states such as Florida and Maine to improve the accuracy of numeric criteria and criteria-based decisions. This includes a preference for developing site-specific criteria in cases where sufficient data are available, and the use of nutrient concentration and biological response criteria together in a framework to support designated use attainment decisions. Together with systematic planning during criteria development, the accuracy of field-derived numeric nutrient criteria can be assessed and maximized as a part of an overall effort to manage nutrient water quality concerns.

Investigation on the trophic status of Ekbatan reservoir: a drinking water supply reservoir in Iran

BACKGROUND

Eutrophication is one of the detrimental environmental problems in water reservoirs dye to the irregular introducing nutrients (phosphorus and nitrogen). This study aimed to explore the eutrophication state of Ekbatan Reservoir, Hamadan, western Iran.

METHODS

Monthly sampling was conducted during April 2010 to March 2011. Seven sampling stations were selected in the various locations of the reservoir and the samples were collected in the depth of 50 cm. The grab sampling of water for nitrogen, phosphorous and chlorophyll-a was carried out at all localities by Hatch sampler. The trophic state of the dam was determined by Carlson's Trophic State Index (TSI) and Chapra's classification.

RESULTS

The highest concentrations of phosphorus and chlorophyll-a were measured in August and the lowest concentration for both of the parameters was determined in February. The TSI index according phosphorus concentration showed that the reservoir was in eutrophic status during May to November and was in mesotrophic status over November to May.

CONCLUSIONS

It seems that the eutrophication process in the lake was resulted from the rural wastewaters and agricultural fertilizers. Therefore, using long term management methods including prevent of uncontrolled discharge of agricultural wastewaters is recommended in order to reduce the eutrophication in the reservoir. Decrease of phosphorus concentration in the dam by 50% can convert the eutrophic state to mesotrophic state.

Anaerobic digestate as substrate for microalgae culture: the role of ammonium concentration on the microalgae productivity

In spite of the increasing interest received by microalgae as potential alternatives for biofuel production, the technology is still not industrially viable. The utilization of digestate as carbon and nutrients source can enhance microalgal growth reducing costs and environmental impacts. This work assesses microalgal growth utilizing the liquid phase of anaerobic digestate effluent as substrate. The effect of inoculum/substrate ratio on microalgal growth was studied in a laboratory batch experiment conduced in 0.5L flasks. Results suggested that digestate may be an effective substrate for microalgal growth promoting biomass production up to 2.6 gTSS/L. Microalgal growth rate was negatively affected by a self-shading phenomenon, while biomass production was positively correlated with the inoculum and substrate concentrations. Thus, the increasing of both digestate and microalgal initial concentration may reduce the initial growth rate (μ from 0.9 to 0.04 d(-1)) but significantly enhances biomass production (from 0.1 to 2.6 gTSS/L).

Spatiotemporal statistical modelling of long-term change in river nutrient concentrations in England & Wales

Concentrations of nutrient nitrogen (N) and phosphorus (P) are elevated in rivers across large areas of Europe (European Nitrogen Assessment (ENA), Sutton et al., 2011). Environmental policies have been implemented over the past 20 years with the aim of reducing nitrogen inputs to surface waters. However, environmental and ecological status is still below set targets (ENA, Sutton et al., 2011). Identification of patterns in long-term change for nutrient trends in hydrological catchments in England & Wales is required to assess impacts of nutrient management policy and provide better evidence for future policy. Such information could provide essential evidence for supporting policy by combining information from the wider catchment, rather than relying on the analysis of data from individual sites. Surface water quality is subject to considerable spatial and short-period temporal variability, reflecting variability in loading and dilution. This makes it difficult to determine temporal trends at individual monitoring sites with relatively sparse sampling. Here we apply spatiotemporal statistical additive models for both nitrogen and phosphorus in river networks across England & Wales to investigate the overall pattern of nutrient concentrations in these river surface waters over the past 20-40 years. Concentrations of Orthophosphate (OP) have generally decreased over time for many of the Large Hydrological Areas with a seasonal pattern highlighting one peak in the summer months. Over the past ten years, Total Oxidised Nitrogen (Nitrate+Nitrite, TON) concentrations have generally been slowly decreasing or fairly constant. However, prior to 2000, concentrations were generally on an upward trend. The seasonal pattern highlights one trough in the summer months. The highest levels for OP and TON broadly occur in the same general areas across England & Wales. On average, over time, the lowest values are evident in the north-west and south-west (particularly for OP) and highest values are evident in the Midlands, Anglian and Southern regions.

Reducing future nutrient inputs to the Black Sea

Rivers export increasing amounts of dissolved inorganic (DIN, DIP) and organic (DON, DOP) nitrogen and phosphorus to the Black Sea causing coastal eutrophication. The aim of this study is to explore future trends in river export of these nutrients to the sea through a sensitivity analysis. We used the Global NEWS (Nutrient Export from WaterSheds) model to this end. We calculated that between 2000 and 2050 nutrient inputs to the Black Sea may increase or decrease, depending on the assumed environmental management. We analyzed the effects of agricultural and sewage management on nutrient inputs to the sea in 2050 relative to two Millennium Ecosystem Assessment (MEA) scenarios, Global Orchestration (GO) and Adaptive Mosaic (AM). In these baselines, total N and P inputs to the Black Sea decrease between 2000 and 2050, but not for all rivers and nutrient forms. Our results indicate that it is possible to reduce nutrient inputs to the sea further between 2000 and 2050 in particular for dissolved inorganic N and P and for many river basins, but not for all. For scenarios assuming combined agricultural and sewage management dissolved inorganic N and P inputs to the Black Sea are reduced by up to two-thirds between 2000 and 2050 and dissolved organic N and P inputs by one-third. River export of DIN is mainly affected by agricultural management and that of DIP by sewage management. On the other hand, in scenarios assuming increased fertilizer use for, for instance bioenergy crops, nutrient inputs to the sea increase. An increase in DIP inputs by southern rivers seems difficult to avoid because of the increasing number of people connected to sewage systems.

Ecology of the ciguatera causing dinoflagellates from the Northern Great Barrier Reef: changes in community distribution and coastal eutrophication

Ciguatera fish poisoning (CFP) is known to be caused by the ciguatoxins from the dinoflagellate genus Gambierdiscus, however, there is the potential for other toxins such as okadaic acid and dinophysistoxins from the genus Prorocentrum, and palytoxin from the genus Ostreopsis, to contaminate seafood. These genera may also be indicators of ecosystem health and potentially impact on coral reef ecosystems and the role they may play in the succession of coral to macroalgae dominated reefs has not been researched. Sixteen GBR field sites spanning inshore, mid-lagoon and outer lagoon (offshore) regions were studied. Samples were collected from September 2006 to December 2007 and abundance of benthic dinoflagellates on different host macroalgae and concentration of nutrients present in the water column were determined. The maximum abundance of Prorocentrum, Ostreopsis and Gambierdiscus found was 112, 793 and 50 cells per gram wet weight of host macroalgae, respectively. The average level of Dissolved Inorganic Nitrogen (DIN) in the water column across all sites (0.03 mg/L) was found to be more than double the threshold critical value (0.013 mg/L) for healthy coral reefs. Compared to a previous study 1984, there is evidence of a major shift in the distribution and abundance of these dinoflagellates. Inshore reefs have either of Prorocentrum (as at Green Island) or Ostreopsis (as at Magnetic Island) dominating the macroalgal surface niche which was once dominated by Gambierdiscus, whilst at offshore regions Gambierdiscus is still dominant. This succession may be linked to the ongoing eutrophication of the GBR lagoon and have consequences for the sources of toxins for ongoing cases of ciguatera.

Quantifying benefits of resource recovery from sanitation provision in a developing world setting

Despite concerns of sanitation provision, water scarcity, climate change, and resource depletion, limited research has been conducted to assess the environmental impact of wastewater treatment and resource recovery strategies to improve access to sanitation and resource utilization in developing world settings. Accordingly, the goal of this study is to evaluate the potential benefits of mitigating the environmental impact of two small community-managed wastewater treatment systems in rural Bolivia using resource recovery (i.e., water reuse and energy recovery). Life Cycle Assessment (LCA) is used to estimate the embodied energy, carbon footprint, and eutrophication potential of these systems under existing and resource recovery conditions. Two distinct technologies are analyzed: (1) an upflow anaerobic sludge blanket reactor (UASB) followed by two maturation ponds in series (UASB-Pond system) and (2) a facultative pond followed by two maturation ponds in series (3-Pond system). For the existing systems, bathroom and collection infrastructure had a higher energy intensity than the treatment processes, whereas direct methane emissions from treatment were the primary contributors to the carbon footprint. Taking advantage of reclaimed water was found to greatly reduce the eutrophication potential for both systems, in which the reduction increases proportionally to the percentage of water that is reclaimed. Energy recovery from the UASB-Pond system provided a 19% reduction in embodied energy and a 57% reduction in carbon footprint. Combining water reuse and energy recovery for the UASB-Pond system reduced the eutrophication potential, embodied energy and carbon footprint simultaneously. This highlights the benefits of integrated resource recovery.

Effect of substrate depth and rain-event history on the pollutant abatement of green roofs

This study compares the effectiveness of two different thickness of green roof substrate with respect to nutrient and heavy metal retention and release. To understand and evaluate the long term behaviour of green roofs, substrate columns with the same structure and composition as the green roofs, were exposed in laboratory to artificial rain. The roofs act as a sink for C, N, P, zinc and copper for small rain events if the previous period was principally dry. Otherwise the roofs may behave as a source of pollutants, principally for carbon and phosphorus. Both field and column studies showed an important retention for Zn and Cu. The column showed, however, lower SS, DOC and metal concentrations in the percolate than could be observed in the field even if corrected for run-off. This is most probably due to the difference in exposition history and weathering processes.

Retrofitting impervious urban infrastructure with green technology for rainfall-runoff restoration, indirect reuse and pollution load reduction

The built environs alter hydrology and water resource chemistry. Florida is subject to nutrient criteria and is promulgating "no-net-load-increase" criteria for runoff and constituents (nutrients and particulate matter, PM). With such criteria, green infrastructure, hydrologic restoration, indirect reuse and source control are potential design solutions. The study simulates runoff and constituent load control through urban source area re-design to provide long-term "no-net-load-increases". A long-term continuous simulation of pre- and post-development response for an existing surface parking facility is quantified. Retrofits include a biofiltration area reactor (BAR) for hydrologic and denitrification control. A linear infiltration reactor (LIR) of cementitious permeable pavement (CPP) provides infiltration, adsorption and filtration. Pavement cleaning provided source control. Simulation of climate and source area data indicates re-design achieves "no-net-load-increases" at lower costs compared to standard construction. The retrofit system yields lower cost per nutrient load treated compared to Best Management Practices (BMPs).

Estimating farm to catchment nutrient fluxes using dynamic simulation modelling--can agri-environmental BMPs really do the job?

A dynamic model of Phosphorus (P) movement through the Peel-Harvey catchment in South Western Australia was developed using system dynamics modelling software. The model was developed to illustrate watershed P flux and to predict future P loss rates under a range of management scenarios. Model input parameters were sourced from extensive surveys of local agricultural practices and regional soil testing data. Model P-routing routines were developed from the known interactions between the various watershed P compartments and fluxes between the various P stores. Phosphorus-retention characteristics of a variety of management practices were determined from local field trials where available and published values where not. The model simulated a 200 year time frame to reflect 100 years to the present day since initial land development, and forecast 100 years into the future. Although the catchment has an annual P-loss target of 70 tonnes per annum (tpa), the measured (and modelled) present-day loss is double this amount (140 tpa) and this is projected to rise to 1300 tpa if current land management practices continue. Broad implementation of neither "biological" BMPs such as perennial pastures and managed riparian zones, or of "chemical" BMPs such as reduced water solubility fertilisers and P-retentive soil amendments, produces reductions in P-loss from present-day levels. Even if broad-scale implementation of the large suite of BMPs tested in this research occurs, catchment P-losses are likely to increase from the present level of 140 tpa to approximately 200 tpa over the next 100 years. This has significant implications for both future land use and subsequent water quality in the catchment as well as questioning the wisdom and perceptions of efficacy of past and future BMP implementation strategies.

Effect of decapitation and nutrient applications on shoot branching, yield, and accumulation of secondary metabolites in leaves of Stevia rebaudiana Bertoni

The axillary buds of stevia (Stevia rebaudiana Bertoni) often remain dormant for a long time and sometimes remain dormant permanently until the plants enter into the reproductive stage. The present study was conducted to ascertain whether decapitation and foliar fertilization enhance the productivity and quality of stevia through breaking the apical dominance and increasing physiological activities. Ten treatment combinations comprising two cultural operations (non-decapitation and decapitation) and five foliar spray treatments (water spray control, KNO3 @ 5.0gL(-1), Ca(NO3)2 @ 4.06gL(-1), CuSO4·5H2O 2.0gL(-1) and (NH4)6Mo7O24 @ 1.0gL(-1)) were applied. The decapitation of apical buds of stevia increased the branches and increased dry leaf yield by 13 and 17% compared with non-decapitation during 2010 and 2011, respectively, without affecting quality. Foliar application of nutrient solutions also exerted a considerable effect on growth parameters, yield attributes and chlorophyll content, and significantly (P=0.05) higher dry leaf yield ranging from 8 to 26% over the control. Among the foliar spray treatments, KNO3 @ 5.0gL(-1) and Ca (NO3)2 4.06gL(-1) were found most effective in dry leaf yield. Thus, the decapitation of apical buds and foliar application of KNO3 and Ca (NO3)2 could enhance the productivity of stevia through improving the growth of axillary buds and physiological activities.

Review of nutrient actions on age-related macular degeneration

The actions of nutrients and related compounds on age-related macular degeneration (AMD) are explained in this review. The findings from 80 studies published since 2003 on the association between diet and supplements in AMD were reviewed. Antioxidants and other nutrients with an effect on AMD susceptibility include carotenoids (lutein and zeaxanthin, β-carotene), vitamins (vitamin A, E, C, D, B), mineral supplements (zinc, copper, selenium), dietary fatty acids [monounsaturated fatty acids, polyunsaturated fatty acids (PUFA both omega-3 PUFA and omega-6 PUFA), saturated fatty acids and cholesterol], and dietary carbohydrates. The literature revealed that many of these antioxidants and nutrients exert a protective role by functioning synergistically. Specifically, the use of dietary supplements with targeted actions can provide minimal benefits on the onset or progression of AMD; however, this does not appear to be particularly beneficial in healthy people. Furthermore, some supplements or nutrients have demonstrated discordant effects on AMD in some studies. Since intake of dietary supplements, as well as exposure to damaging environmental factors, is largely dependent on population habits (including dietary practices) and geographical localization, an overall healthy diet appears to be the best strategy in reducing the risk of developing AMD. As of now, the precise mechanism of action of certain nutrients in AMD prevention remains unclear. Thus, future studies are required to examine the effects that nutrients have on AMD and to determine which factors are most strongly correlated with reducing the risk of AMD or preventing its progression.

Increasing polyhydroxyalkanoate (PHA) yields from Cupriavidus necator by using filtered digestate liquors

The production of polyhydroxyalkanoates (PHAs) using digestate liquor as culture media is a novel application to extend the existing uses of digestates. In this study, two micro-filtered digestates (0.22 μm) were evaluated as a source of complex culture media for the production of PHA by Cupriavidus necator as compared to a conventional media. Culture media using a mixture of micro-filtered liquors from food waste and from wheat feed digesters showed a maximum PHA accumulation of 12.29 g/l PHA, with 90% cell dry weight and a yield of 0.48 g PHA/g VFA consumed, the highest reported to date for C. necator studies. From the analysis of the starting and residual media, it was concluded that ammonia, potassium, magnesium, sulfate and phosphate provided in the digestate liquors were vital for the initial growth of C. necator whereas copper, iron and nickel may have played a significant role in PHA accumulation.

[Evaluation of diet and nutrient intake in children under three years old. ALSALMA pilot study]

OBJECTIVE

The present study evaluates energy and nutrient intake in Spanish children under three years of age, and compares the results with the current recommendations in order to identify possible inadequate nutrient intake.

PATIENTS AND METHODS

A cross-sectional pilot study. The mothers completed a diet diary for four non-consecutive days, recording the products and amounts consumed by their children. Nutrient intake was calculated, and the results were compared with the dietary reference intakes (DRI) for each age group.

RESULTS

A total of 188 children (93 boys and 95 girls) aged 0-6 (n=41), 7-12 (n=24), 13-24 (n=57), and 25-36 months (n=66) were included. Statistically significant differences in DRI were observed for most of the nutrients analyzed. Protein intake, in particular was 376% of DRI in children between 1-3 years of age. By age groups, 96% of the children aged 7-12 months, 88% of the children aged 13-24 months, and 97% of the children aged 25-36 months showed protein intakes more than two-fold DRI.

CONCLUSIONS

Nutrient intake differed from the DRI, particularly as regards proteins. A new study is required to determine whether the observed study deviations could be representative of the national population of this age group, as well as the possible effects on child health.

A comparative perspective on lipid storage in animals

Lipid storage is an evolutionary conserved process that exists in all organisms from simple prokaryotes to humans. In Metazoa, long-term lipid accumulation is restricted to specialized cell types, while a dedicated tissue for lipid storage (adipose tissue) exists only in vertebrates. Excessive lipid accumulation is associated with serious health complications including insulin resistance, type 2 diabetes, cardiovascular diseases and cancer. Thus, significant advances have been made over the last decades to dissect out the molecular and cellular mechanisms involved in adipose tissue formation and maintenance. Our current understanding of adipose tissue development comes from in vitro cell culture and mouse models, as well as recent approaches to study lipid storage in genetically tractable lower organisms. This Commentary gives a comparative insight into lipid storage in uni- and multi-cellular organisms with a particular emphasis on vertebrate adipose tissue. We also highlight the molecular mechanisms and nutritional signals that regulate the formation of mammalian adipose tissue.

The combined impact of land use change and aquaculture on sediment and water quality in oligotrophic Lake Rupanco (North Patagonia, Chile, 40.8°S)

Water and sediment quality in North Patagonia's large, oligotrophic lakes are expected to suffer as native forest continues to be fragmented and degraded by its conversion to cropping and pasture land uses. These changes in land use are expected to increase diffuse nutrient loads to the region's lakes. In addition, these lakes are home to the world's second largest salmon aquaculture industry which provides additional point sources of nutrients within the lakes. We studied the combined influences of land use change and salmon farming on the nutrient concentrations in a North Patagonian lake (Lake Rupanco, 233 km(2) water surface, 163 m average depth) in four sub-watersheds ranging in disturbance from near-pristine forest to 53% converted to cropping and pasture. Nitrogen exports from the tributary sub-watersheds increased from 33 kg TN/km(2)/y to 621 kg TN/km(2)/y as the proportion of crop and pasture land increased. The combined nutrient load from land use change and salmon farming has led to significant differences in the nitrogen concentrations of the lake's water column and sediments in the near-shore zones across the lake. Total nitrogen concentrations in the sediments varied from 37 ± 18 mg/kg in near-pristine sub-watersheds without salmon farming to 6400 ± 698 mg/kg where the sub-watershed was dominated by crop and pasture lands combined with the presence of salmon farming. These results demonstrate the importance of considering the impacts of both salmon farming and land use on water and sediment quality for future environmental planning, management and decision making.

Impact of environmental conditions on the suitability of microconstituents as markers for determining nutrient loading from reclaimed water

Nitrogen and phosphorous loading into waterways from designated beneficial uses of reclaimed water is a growing concern in many parts of the United States. Numerous studies have documented that organic microconstituents present in the reclaimed water can be utilized as indicators of its influence on surface water bodies. However, little to no information is available on the environmental attenuation of these microconstituents relative to the nutrients, which is a critical component in determining the effectiveness or limitations of those markers as a tool for elucidating their origins. In this study, the stability of selected markers (sucralose, carbamazepine, gadolinium anomaly, iohexol, and atenolol) was evaluated through bench-scale studies designed to simulate environmental conditions associated with biodegradation, adsorption, and photolysis. The primary pathway for nitrogen reduction was biodegradation (greater than 99%) while the highest phosphorous removal was due to adsorption (30-80%). Soils with low organic content were selected for this study. Sucralose was the most recalcitrant microconstituent in the environment with less than 15% removal by adsorption, biodegradation, or photolysis. Iohexol was too susceptible to photolysis (90% removal), and atenolol was susceptible to biodegradation (60-80% removal). Gd anomaly was fairly stable (less than 30% removal) in the environment. Carbamazepine was another efficacious marker for wastewater, but was susceptible (50% removal) to photolysis. Of the selected microconstituents, only atenolol showed any similarity with the attenuation observed for nitrate and none of the microconstituents showed any similarity with the attenuation observed for phosphorus.

Monitoring of impact of anthropogenic inputs on water quality of mangrove ecosystem of Uran, Navi Mumbai, west coast of India

Surface water samples were collected from substations along Sheva creek and Dharamtar creek mangrove ecosystems of Uran (Raigad), Navi Mumbai, west coast of India. Water samples were collected fortnightly from April 2009 to March 2011 during spring low and high tides and were analyzed for pH, Temperature, Turbidity, Total solids (TS), Total dissolved solids (TDS), Total suspended solids (TSS), Dissolved oxygen (DO), Biochemical oxygen demand (BOD), Carbon dioxide (CO2), Chemical oxygen demand (COD), Salinity, Orthophosphate (O-PO4), Nitrite-nitrogen (NO2-N), Nitrate-nitrogen (NO3-N), and Silicates. Variables like pH, turbidity, TDS, salinity, DO, and BOD show seasonal variations. Higher content of O-PO4, NO3-N, and silicates is recorded due to discharge of domestic wastes and sewage, effluents from industries, oil tanking depots and also from maritime activities of Jawaharlal Nehru Port Trust (JNPT), hectic activities of Container Freight Stations (CFS), and other port wastes. This study reveals that water quality from mangrove ecosystems of Uran is deteriorating due to industrial pollution and that mangrove from Uran is facing the threat due to anthropogenic stress.

Impact of co-digestion on existing salt and nutrient mass balances for a full-scale dairy energy project

Anaerobic digestion of manure and other agricultural waste streams with subsequent energy production can result in more sustainable dairy operations; however, importation of digester feedstocks onto dairy farms alters previously established carbon, nutrient, and salinity mass balances. Salt and nutrient mass balance must be maintained to avoid groundwater contamination and salination. To better understand salt and nutrient contributions of imported methane-producing substrates, a mass balance for a full-scale dairy biomass energy project was developed for solids, carbon, nitrogen, sulfur, phosphorus, chloride, and potassium. Digester feedstocks, consisting of thickened manure flush-water slurry, screened manure solids, sudan grass silage, and feed-waste, were tracked separately in the mass balance. The error in mass balance closure for most elements was less than 5%. Manure contributed 69.2% of influent dry matter while contributing 77.7% of nitrogen, 90.9% of sulfur, and 73.4% of phosphorus. Sudan grass silage contributed high quantities of chloride and potassium, 33.3% and 43.4%, respectively, relative to the dry matter contribution of 22.3%. Five potential off-site co-digestates (egg waste, grape pomace, milk waste, pasta waste, whey wastewater) were evaluated for anaerobic digestion based on salt and nutrient content in addition to bio-methane potential. Egg waste and wine grape pomace appeared the most promising co-digestates due to their high methane potentials relative to bulk volume. Increasing power production from the current rate of 369 kW to the design value of 710 kW would require co-digestion with either 26800 L d(-1) egg waste or 60900 kg d(-1) grape pomace. However, importation of egg waste would more than double nitrogen loading, resulting in an increase of 172% above the baseline while co-digestion with grape pomace would increase potassium by 279%. Careful selection of imported co-digestates and management of digester effluent is required to manage salt and nutrient mass loadings and reduce groundwater impacts.

Bioremediation of reject water from anaerobically digested waste water sludge with macroalgae (Ulva lactuca, Chlorophyta)

Phosphorus and biologically active nitrogen are valuable nutrient resources. Bioremediation with macroalgae is a potential means for recovering nutrients from waste streams. In this study, reject water from anaerobically digested sewage sludge was successfully tested as nutrient source for cultivation of the green macroalgae Ulva lactuca. Maximal growth rates of 54.57±2.16% FW d(-1) were achieved at reject water concentrations equivalent to 50 μM NH4(+). Based on the results, the growth and nutrient removal was parameterised as function of NH4(+) concentration a tool for optimisation of any similar phycoremediation system. Maximal nutrient removal rates of 22.7 mg N g DW(-1) d(-1) and 2.7 mg P g DW(-1) d(-1) were achieved at reject water concentrations equivalent to 80 and 89 μM NH4(+), respectively. A combined and integrated use of the produced biomass in a biorefinery is thought to improve the feasibility of using Ulva for bioremediation of reject water.

Using 222Rn to estimate submarine groundwater discharge (SGD) and the associated nutrient fluxes into Xiangshan Bay, East China Sea

Continuous radon ((222)Rn) monitoring was conducted at two stations (site A and site B) with different perpendicular distance from the shoreline in Xiangshan Bay, East China Sea. Based on a (222)Rn balance model (various sources and sinks of (222)Rn in coastal water), the average rate of SGD was estimated to be 0.69 cm/day and 0.23 cm/day for site A and site B, respectively. The results from a nutrient analysis of the groundwater indicate that the associated nutrients fluxes loading through the SGD pathway were 4.27×10(6) mol/day for DIN, 2.24×10(4) mol/day for DIP and 1.82×10(6) mol/day for DSi, respectively, which were comparable to or even higher than the levels observed in the local streams. Therefore, adequate attention should be paid to the importance of SGD as one source of nutrients during the eutrophication control process in this area.

Co-digestion of solid poultry manure with municipal sewage sludge

The anaerobic digestion was investigated using mixed sewage sludge and poultry manure. The experiments showed that a 30% addition of poultry manure to the sewage sludge did not increase specific gas yield (376 dm(3)/kg VS versus 384 dm(3)/kg VS), however gas production rate as calculated per unit volume was 1.5 higher for sludge and manure mixture. The anaerobic digestion turned out to be inefficient in terms of pathogen treatment, since the reduction of Enterobacteriaceae reached only two logarithmic units. In the course of the digestion processes, nutrients were released to the supernatant, and longer SRT favored that phenomenon. The liquor after the digestion of sludge alone was rich in phosphates (348-358 gP/m(3)) and contained a lot of organic carbon (COD of 2705-6034 gO2/m(3)). Conversely, more ammonium nitrogen was found in the supernatant after co-digestion of sludge with manure (2094-2221 gN/m(3)). However, there was no evidence of ammonia inhibition.

Nutrient intake and peripheral artery disease in adults: key considerations in cross-sectional studies

BACKGROUND & AIMS

There are limited studies of nutrient intake and peripheral artery disease (PAD). Some studies have not accounted for the functional consequences of PAD, potentially leading to biased results. To determine the associations between intakes of dietary fiber, folate, vitamins A, C, E, and B6 and PAD.

METHODS

Cross-sectional analysis of 6534 adults aged 40 years and older in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004, including measurement of ankle-brachial index (ABI) and nutrient intake by 24-h dietary recall. Weighted multivariable logistic regression models to determine odds ratios and 95% confidence intervals.

RESULTS

The prevalence of PAD (ABI < 0.9) was 5.3% (4.7-5.9). Inverse associations between PAD and intakes of fiber, folate, and vitamins A, B6, C, and E were statistically significant when adjusting for age, sex, hypertension, diabetes and smoking. In models further adjusted for energy intake and physical activity, these odds ratios all became null (p ≥ 0.1).

CONCLUSIONS

In this sample, dietary fiber, folate, and vitamins B6, C, and E were not associated with PAD after accounting for energy intake and activity. Adjustment for energy and physical activity are essential to avoid bias due to reverse causation in cross-sectional studies of diet and PAD.

Oxidative stress decreases uptake of neutral amino acids in a human placental cell line (BeWo cells)

Increased oxidative stress (OS) is implicated in the pathophysiology of several pregnancy disorders. We aimed to investigate the effect of tert-butylhydroperoxide (TBHP)-induced OS upon the placental transport of the neutral amino acids L-methionine (L-Met) and L-alanine (L-Ala), by using a human trophoblast cell model (BeWo cells). TBHP reduced both total and Na(+)-independent (14)C-L-Met intracellular steady-state accumulation over time (Amax), by reducing non-system L-mediated uptake - most probably system y(+) - while having no effect on system L. Moreover, TBHP reduced total (14)C-L-Ala Amax through an inhibition of system A. The effect of TBHP upon total, but not system A-mediated, (14)C-L-Ala uptake was dependent upon phosphoinositide 3-kinase (PI3K) and protein kinase C (PKC) activation, and was completely prevented by the polyphenol quercetin. In conclusion, a reduction in placental uptake of neutral amino acids may contribute to the deleterious effects of pregnancy disorders associated with OS.

Application of Reclaimed Wastewater in the Irrigation of Rosebushes

The use of reclaimed wastewater in agriculture can be a solution for regions with water shortages or low rainfall periods; besides fulfilling the crop's water needs, it would also promote the recycle of nutrients. However, care should be taken regarding soil salinization, especially in closed environments such as greenhouses for the cultivation of ornamental plants. The domestic effluents are rich in sodium which can accumulate on soil and cause soil sealing. This study evaluated the use of effluents from anaerobic filters and intermittent sand filters in the production of rosebushes (Rosa hybrida "Ambiance"). The crop yield of the rosebushes irrigated with reclaimed wastewater exceeded the one obtained with traditional cultivation, reaching a value 31.8 % higher when employing nitrified effluent originated from intermittent sand filters, with no difference in the product quality. The salinity levels are below the critical limits found in the literature; however, there was a significant increase compared to the irrigation with drinking water.

Body Composition and Dietary Intake of Elite Cross-country Skiers Members of the Greek National Team

PURPOSE

To assess the anthropometric characteristics and dietary intake of the Greek national cross-country skiing team.

METHODS

Thirty-three athletes (10 females aged 20 ± 5 years; 23 males aged 20 ± 6 years old) participated in the study. All athletes were members of the Greek national ski team, and they had been selected to take part in the Winter Olympics, World Ski Championships, European Ski Championships or other international events, according to their performance. Body composition was estimated by bioelectrical impedance (BIA) and skinfold thickness. The athletes recorded their physical activity and dietary intake for 3 training days, and on a competition day.

RESULTS

The female skiers had 14.2±1.9% body fat, the men 11.0±1.5% body fat. Female athletes consumed a diet of 1988±319 Kcal during training days and 2011±330 Kcal during competition days. Male athletes consumed 2255±790 Kcal and 2125±639 Kcal respectively. These values are below those recommended for highly active people. During the training period, carbohydrate, fat and protein contributed to 44.5±7.1%, 39.2±5.3% and 16.1±3.7% of the total energy intake (EI) respectively for the males, and to 52.8±5.6%, 33.0±3.7% and 14.3±2.5% of the EI of the women. Between training and competition days, men demonstrated an increased carbohydrate and reduced fat consumption when competing (P<0.001 for both). Women, on the other hand, consumed more carbohydrate and less protein during competition days (P<0.05 for both). Protein intake was within the recommended range for both males and females, but fat exceeded the recommended values and was consumed at the expense of carbohydrate. Vitamins B(12), D, E and K, biotin, folate, Ca, Mg, K, I were inadequately consumed (below the RDA) by both women and men, while the women also exhibited inadequate intakes of iron and the men of manganese.

CONCLUSIONS

The inadequate energy and nutrient intake in the Greek national cross-country ski team could put the athletes at risk of nutritional deficiencies, and possibly compromise their athletic performance.

Association between nutrient intake and obesity in type 2 diabetic patients from the Korean National Diabetes Program: a cross-sectional study

The aim of the study was to assess the association between usual dietary nutrient intake and obesity in Korean type 2 diabetic patients. We examined 2,832 type 2 diabetic patients from the Korean National Diabetes Program cohort who completed dietary assessment and clinical evaluation in this cross-sectional study. In men, higher dietary fiber intake was associated with a lower odds of being obese (P(trend) = 0.003) and in women, higher protein intake was associated with a lower odds of being obese (P(trend) = 0.03) after adjustment for age, diabetes duration, HbA1c, alcohol drinking, income, education level, and calorie intake. In men, higher fiber intake was associated with lower odds of obesity after further adjustment for diastolic blood pressure, physical activity, and possible confounding nutritional intake and medication. The multivariable adjusted odds ratio for the highest quintile of fiber intake was 0.37 (P(trend) < 0.001). In women, protein intake was not associated with obesity after further adjustment. In conclusion, higher intake of dietary fiber is associated with lower odds of being obese in type 2 diabetic men, suggesting a role for dietary fiber in the management and prevention of obesity in type 2 diabetes (ClinicalTrials.gov: NCT 01212198).

SU-E-T-08: Simple Governing Equations for Tumor Growth

PURPOSE

To derive a set of simple differential equations, which can represent temporal growth of typical tumors, by taking into account the effects of the tumor microenvironment on cell proliferation.

METHODS

Cause-effect relationships between cell proliferation and nutrients contained in blood stream, which included oxygen and glucose, were modeled. By formulating a set of rate equations and simplifying those, we finally obtained two differential equations. One equation represents the change of the tumor mass and included time-varying growth rate, which was a solution of another equation relating the growth rate with the blood volume in the tumor. The set of differential equations were numerically solved by varying a parameter, kappa, which represented the growth rate of the blood volume relative to the tumor mass.

RESULTS

Through numerical experiments we showed that the tumor volume increased exponentially if the blood volume increased at the same rate as the tumor. However, the blood volume did not increase rapidly enough as the tumor grew, the tumor showed the saturation in the growth when the tumor grew by 1000-fold. Such a retardation of tumor growth was experimentally observed and the function representing the growth curve is called as Gompertz equation. One of solutions also showed that the tumor stopped growing when the blood supply was shut off (or kappa = 0).

CONCLUSIONS

A solution of simple differential equations derived in this study could reproduce the tumor growth which can be represented by the well known Gompertz equation. Using these equations we were able to theoretically show that the saturation of tumor growth observed often for larger tumors could be explained by a relative lack of blood supply which leads to a decrease in the cell proliferation rate. In a future study the effects of radiation on the tumor growth will be included in the model.

Nutrient composition of spent wash and its impact on sugarcane growth and biochemical attributes

Nutrient composition of crude and digested spent wash and effect of their application on sugarcane growth and biochemical attributes were studied. Higher concentrations of essential nutrients (P, S, Fe, Mn, Zn, Cu) and heavy metals (Cd, Cr, Ni and Pb) were present in crude spent wash (CSW) as compared to the digested spent wash (DSW); sulphur content was the highest (765 μg ml(-1) in DSW and 1,609 μg ml(-1) in CSW) among all nutrients analyzed. Sugarcane (Saccharum spp. hybrid cultivar CoLk 8102) setts grown in soil pot culture conditions with different rates of crude spent wash (5, 10, 20 and 100 ml kg(-1) soil) along with digested spent wash (100 ml kg(-1) soil) showed improvement in bud sprouting (10.5 %), settling height (40 %), root number (9.4 %), root length (13.2 %), chlorophyll a (52.9 %) and b (55.3 %) contents and activity of catalase (98 %) enzyme over control at low rate of crude spent wash (5 ml kg(-1) soil). Whereas, higher doses of spent wash (20 and 100 ml kg(-1) soil) decreased these parameters markedly except peroxidase which was found higher at all the levels of both CSW and DSW. Findings indicated stimulatory effect of low rate of crude spent wash (5 ml kg(-1) soil) on root and shoot growth and inhibitory effect of higher dose (100 ml kg(-1) soil) of both crude and digested spent wash, therefore, judicious application of spent wash will improve crop productivity and alleviate environmental pollution problems.

Effects of cooking methods and temperatures on nutritional and quality characteristics of anchovy (Engraulis encrasicholus)

The aim of this study was to determine the nutritional and quality characteristics of anchovy after cooking. The fish were cooked by different methods (frying, baking and grilling) at two different temperatures (160 °C, 180 °C). Crude ash, crude protein and crude fat contents of cooked fish increased due to rise in dry matter contents. While cooking methods affected mineral content of anchovy, cooking temperature did not affect. The highest values of monounsaturated fatty acids were found in baked samples. Polyunsaturated fatty acids in baked samples were also high and similar in fried samples. Fried samples, which were the most preferred, lost its nutritional characteristics more than baked and grilled samples. Grilled and baked fish samples can be recommended for healthy consumption. However, grilled fish samples had hard texture due to more moisture loss than other methods. Therefore, it is concluded that baking is the best cooking method for anchovy.

Nutrition and physical activity in NAFLD: an overview of the epidemiological evidence

Nonalcoholic fatty liver disease (NAFLD) has been recognized as a major health burden. The high prevalence of NAFLD is probably due to the contemporary epidemics of obesity, unhealthy dietary pattern, and sedentary lifestyle. The efficacy and safety profile of pharmacotherapy in the treatment of NAFLD remains uncertain and obesity is strongly associated with hepatic steatosis; therefore, the first line of treatment is lifestyle modification. The usual management of NAFLD includes gradual weight reduction and increased physical activity (PA) leading to an improvement in serum liver enzymes, reduced hepatic fatty infiltration, and, in some cases, a reduced degree of hepatic inflammation and fibrosis. Nutrition has been demonstrated to be associated with NAFLD and Non-alcoholic steatohepatitis (NASH) in both animals and humans, and thus serves as a major route of prevention and treatment. However, most human studies are observational and retrospective, allowing limited inference about causal associations. Large prospective studies and clinical trials are now needed to establish a causal relationship. Based on available data, patients should optimally achieve a 5%-10% weight reduction. Setting realistic goals is essential for long-term successful lifestyle modification and more effort must be devoted to informing NAFLD patients of the health benefits of even a modest weight reduction. Furthermore, all NAFLD patients, whether obese or of normal weight, should be informed that a healthy diet has benefits beyond weight reduction. They should be advised to reduce saturated/trans fat and increase polyunsaturated fat, with special emphasize on omega-3 fatty acids. They should reduce added sugar to its minimum, try to avoid soft drinks containing sugar, including fruit juices that contain a lot of fructose, and increase their fiber intake. For the heavy meat eaters, especially those of red and processed meats, less meat and increased fish intake should be recommended. Minimizing fast food intake will also help maintain a healthy diet. PA should be integrated into behavioral therapy in NAFLD, as even small gains in PA and fitness may have significant health benefits. Potentially therapeutic dietary supplements are vitamin E and vitamin D, but both warrant further research. Unbalanced nutrition is not only strongly associated with NAFLD, but is also a risk factor that a large portion of the population is exposed to. Therefore, it is important to identify dietary patterns that will serve as modifiable risk factors for the prevention of NAFLD and its complications.

Nutrition and physical activity in NAFLD: An overview of the epidemiological evidence

Nonalcoholic fatty liver disease (NAFLD) has been recognized as a major health burden. The high prevalence of NAFLD is probably due to the contemporary epidemics of obesity, unhealthy dietary pattern, and sedentary lifestyle. The efficacy and safety profile of pharmacotherapy in the treatment of NAFLD remains uncertain and obesity is strongly associated with hepatic steatosis; therefore, the first line of treatment is lifestyle modification. The usual management of NAFLD includes gradual weight reduction and increased physical activity (PA) leading to an improvement in serum liver enzymes, reduced hepatic fatty infiltration, and, in some cases, a reduced degree of hepatic inflammation and fibrosis. Nutrition has been demonstrated to be associated with NAFLD and Non-alcoholic steatohepatitis (NASH) in both animals and humans, and thus serves as a major route of prevention and treatment. However, most human studies are observational and retrospective, allowing limited inference about causal associations. Large prospective studies and clinical trials are now needed to establish a causal relationship. Based on available data, patients should optimally achieve a 5%-10% weight reduction. Setting realistic goals is essential for long-term successful lifestyle modification and more effort must be devoted to informing NAFLD patients of the health benefits of even a modest weight reduction. Furthermore, all NAFLD patients, whether obese or of normal weight, should be informed that a healthy diet has benefits beyond weight reduction. They should be advised to reduce saturated/trans fat and increase polyunsaturated fat, with special emphasize on omega-3 fatty acids. They should reduce added sugar to its minimum, try to avoid soft drinks containing sugar, including fruit juices that contain a lot of fructose, and increase their fiber intake. For the heavy meat eaters, especially those of red and processed meats, less meat and increased fish intake should be recommended. Minimizing fast food intake will also help maintain a healthy diet. PA should be integrated into behavioral therapy in NAFLD, as even small gains in PA and fitness may have significant health benefits. Potentially therapeutic dietary supplements are vitamin E and vitamin D, but both warrant further research. Unbalanced nutrition is not only strongly associated with NAFLD, but is also a risk factor that a large portion of the population is exposed to. Therefore, it is important to identify dietary patterns that will serve as modifiable risk factors for the prevention of NAFLD and its complications.

Histone modifications and alcohol-induced liver disease: Are altered nutrients the missing link?

Alcoholism is a major health problem in the United States and worldwide, and alcohol remains the single most significant cause of liver-related diseases and deaths. Alcohol is known to influence nutritional status at many levels including nutrient intake, absorption, utilization, and excretion, and can lead to many nutritional disturbances and deficiencies. Nutrients can dramatically affect gene expression and alcohol-induced nutrient imbalance may be a major contributor to pathogenic gene expression in alcohol-induced liver disease (ALD). There is growing interest regarding epigenetic changes, including histone modifications that regulate gene expression during disease pathogenesis. Notably, modifications of core histones in the nucleosome regulate chromatin structure and DNA methylation, and control gene transcription. This review highlights the role of nutrient disturbances brought about during alcohol metabolism and their impact on epigenetic histone modifications that may contribute to ALD. The review is focused on four critical metabolites, namely, acetate, S-adenosylmethionine, nicotinamide adenine dinucleotide and zinc that are particularly relevant to alcohol metabolism and ALD.

Dietary supplement ingredient database (DSID): Preliminary USDA studies on the composition of adult multivitamin/mineral supplements

The Nutrient Data Laboratory of the United States Department of Agriculture (USDA) is collaborating with the Office of Dietary Supplements (ODS), the National Center for Health Statistics (NCHS), and other government agencies to design and populate a dietary supplement ingredient database (DSID). This analytically based, publicly available database will provide reliable estimates of vitamin and mineral content of dietary supplement (DS) products. The DSID will initially be populated with multivitamin/mineral (MVM) products because they are the most commonly consumed supplements. Challenges associated with the analysis of MVMs were identified and investigated. A pilot study addressing the identification of appropriate analytical methods, sample preparation protocols, and experienced laboratories for the analysis of 12 vitamins and 11 minerals in adult MVM supplement products was completed. Preliminary studies support the development of additional analytical studies with results that can be applied to the DSID. Total intakes from foods and supplements are needed to evaluate the associations between dietary components and health. The DSID will provide better estimates of actual nutrient intake from supplements than databases that rely on label values alone.

Development of a semi-quantitative food frequency questionnaire for middle-aged inhabitants in the Chaoshan area, China

AIM: This paper aims to develop a data-based semi-quantitative food frequency questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guang-dong Province, China, for the investigation of relationships between food intake and lifestyle-related diseases among middle-aged Chinese.

METHODS: We recruited 417 subjects from the general population and performed an assessment of the diet, using a 3-d weighed dietary record survey. We employed contribution analysis (CA) and multiple regression analysis (MRA) to select food items covering up to a 90% contribution and a 0.90 R², respectively. The total number of food items consumed was 523 (443 in the urban and 417 in the rural population) and the intake of 29 nutrients was calculated according to the actual consumption by foods/ recipes.

RESULTS: The CA selected 233, 194, and 183 foods/recipes for the combined, the urban and the rural areas, respectively, and then 196, 157, and 160 were chosen by the MRA. Finally, 125 foods/recipes were selected for the final questionnaire. The frequencies were classified into eight categories and standard portion sizes were also calculated.

CONCLUSION: For adoption of the area-specific SQFFQ, validity and reproducibility tests are now planned to determine how the combined SQFFQ performs in actual assessment of disease risk and benefit.

Increased Salinity Tolerance of Cowpea Plants by Dual Inoculation of an Arbuscular Mycorrhizal Fungus Glomus clarum and a Nitrogen-fixer Azospirillum brasilense

Pot greenhouse experiments were carried out to attempt to increase the salinity tolerance of one of the most popular legume of the world; cowpea; by using dual inoculation of an Am fungus Glomus clarum and a nitrogen-fixer Azospirillum brasilense. The effect of these beneficial microbes, as single- or dual inoculation-treatments, was assessed in sterilized loamy sand soil at five NaCl levels (0.0~7.2 ds/m) in irrigating water. The results of this study revealed that percentage of mycorrhizal infection, plant height, dry weight, nodule number, protein content, nitrogenase and phosphatase activities, as well as nutrient elements N, P, K, Ca, Mg were significantly decreased by increasing salinity level in non-mycorrhized plants in absence of NFB. Plants inoculated with NFB showed higher nodule numbers, protein content, nitrogen concentration and nitrogenase activities than those of non-inoculated at all salinity levels. Mycorrhized plants exhibited better improvement in all measurements than that of non-mycorrhized ones at all salinity levels, especially, in the presence of NFB. The concentration of Na(+) was significantly accumulated in cowpea plants by rising salinity except in shoots of mycorrhizal plants which had K(+)/Na(+) ratios higher than other treatments. This study indicated that dual inoculation with Am fungi and N-fixer Azospirillum can support both needs for N and P, excess of NaCl and will be useful in terms of soil recovery in saline area.

The growth response of plants to elevated CO2 under non-optimal environmental conditions

Under benign environmental conditions, plant growth is generally stimulated by elevated atmospheric CO₂ concentrations. When environmental conditions become sub- or supra-optimal for growth, changes in the biomass enhancement ratio (BER; total plant biomass at elevated CO₂ divided by plant biomass at the current CO₂ level) may occur. We analysed literature sources that studied CO₂×environment interactions on the growth of herbaceous species and tree seedlings during the vegetative phase. For each experiment we calculated the difference in BER for plants that were grown under 'optimal' and 'non-optimal' conditions. Assuming that interactions would be most apparent if the environmental stress strongly diminished growth, we scaled the difference in the BER values by the growth reduction due to the stress factor. In our compilation we found a large variability in CO₂×environment interactions between experiments. To test the impact of experimental design, we simulated a range of analyses with a plant-to-plant variation in size common in experimental plant populations, in combination with a number of replicates generally used in CO₂×environment studies. A similar variation in results was found as in the compilation of real experiments, showing the strong impact of stochasticity. We therefore caution against strong inferences derived from single experiments and suggest rather a reliance on average interactions across a range of experiments. Averaged over the literature data available, low soil nutrient supply or sub-optimal temperatures were found to reduce the proportional growth stimulation of elevated CO₂. In contrast, BER increased when plants were grown at low water supply, albeit relatively modestly. Reduced irradiance or high salinity caused BER to increase in some cases and decrease in others, resulting in an average interaction with elevated CO₂ that was not significant. Under high ozone concentrations, the relative growth enhancement by elevated CO₂ was strongly increased, to the extent that high CO₂ even compensated in an absolute way for the harmful effect of ozone on growth. No systematic difference in response was found between herbaceous and woody species for any of the environmental variables considered.

Initial effects of experimental warming on above- and belowground components of net ecosystem CO2 exchange in arctic tundra

The Arctic contains extensive soil carbon reserves that could provide a substantial positive feedback to atmospheric CO₂ concentrations and global warming. Evaluation of this hypothesis requires a mechanistic understanding of the in situ responses of individual components of tundra net ecosystem CO₂ exchange (NEE) to warming. In this study, we measured NEE, total ecosystem respiration and respiration from below ground in experimentally warmed plots within Alaskan acidic tussock tundra. Soil warming of 2-4°C during a single growing season caused strong increases in total ecosystem respiration and belowground respiration from moss-dominated inter-tussock areas, and similar trends from sedge-dominated tussocks. Consequently, the overall effect of the manipulation was to substantially enhance net ecosystem carbon loss during mid-summer. Components of vascular plant biomass were closely correlated with total ecosystem respiration and belowground respiration in control plots of both microsites, but not in warmed plots. By contrast, in the warmed inter-tussock areas, belowground respiration was most closely correlated with organic-layer depth. Warming in tussock areas was associated with increased leaf nutrient pools, indicating enhanced rates of soil nutrient mineralisation. Together, these results suggest that warming enhanced net ecosystem CO₂ efflux primarily by stimulating decomposition of soil organic matter, rather than by increasing plant-associated respiration. Our short-term experiment provides field evidence to support previous growth chamber and modelling studies indicating that arctic soil C reserves are relatively sensitive to warming and could supply an initial positive feedback to rising atmospheric CO₂ concentrations/changing climate.

Diet breadth of mammalian herbivores: nutrient versus detoxification constraints

Two hypotheses, nutrient constraints and detoxification limitation, have been proposed to explain the lack of specialists among mammalian herbivores. The nutrient constraint hypothesis proposes that dietary specialization in mammalian herbivores is rare because no one plant can provide all requisite nutrients. The detoxification limitation hypothesis suggests that the mammalian detoxification system is incapable of detoxifying high doses of similar secondary compounds present in a diet of a single plant species. We experimentally tested these hypotheses by comparing the performance of specialist and generalist woodrats (Neotoma) on a variety of dietary challenges. Neotoma stephensi is a narrow dietary specialist with a single species, one-seeded juniper, Juniperus monosperma, comprising 85-95% of its diet. Compared with other plants available in the habitat, juniper is low in nitrogen and high in fiber, phenolics, and monoterpenes. The generalist woodrat, N. albigula, also consumes one-seeded juniper, but to a lesser degree. The nutrient constraint hypothesis was examined by feeding both species of woodrats a low-nitrogen, high-fiber diet similar to that found in juniper. We found no differences in body mass change, or apparent digestibility of dry matter or nitrogen between the two species of woodrats after 35 days on this diet. Moreover, both species were in positive nitrogen balance. We tested the detoxification limitation hypothesis by comparing the performance of the generalist and specialist on diets with and without juniper leaves, the preferred foliage of the specialist, as well as on diets with and without α-pinene, the predominant monoterpene in juniper. We found that on the juniper diet, compared with the specialist, the generalist consumed less juniper and lost more mass. Urine pH, a general indicator of overall detoxification processes, declined in both groups on the juniper diet. The generalist consumed half the toxin load of the specialist yet its urine pH was slightly lower. Moreover, the generalist consumed significantly less of the treatment with high concentrations of α-pinene compared to the control treatment, while the specialist consumed the same amount of food regardless of α-pinene concentration. For both groups, urine pH declined as levels of α-pinene in the diet increased. The generalist produced a significantly more acidic urine than the specialist on the treatment with the highest α-pinene concentration. Our results suggest that in this system, specialists detoxify plant secondary compounds differently than generalists and plant secondary compounds may be more important than low nutrient levels in maintaining dietary diversity in generalist herbivores.

Nestling provisioning in water pipits (Anthus spinoletta): do parents go for specific nutrients or profitable prey?

In this study, we investigated whether free-living insectivorous water pipits (Anthus spinoletta) choose prey according to biochemical quality as measured by protein, lipid, carbohydrate, energy and water contents and/or according to profitability as measured by density, size and catchability. Food preference - expressed in relation to availability - is estimated for 22 arthropod taxa (families and orders). Uni- and multivariate statistics detected no relationships between food preference and nutrient contents, but revealed that more larger prey items are fed to nestlings than smaller ones, both for all prey taken together and within individual taxa. Furthermore, slow-flying arthropods, which are easier to catch, were usually preferred over walking and fast-flying ones. Combined with results from previous studies on the effects of vegetation, prey density and catchability on search times and energy intake, these findings suggest that water pipits select their prey primarily to maximize profitability, i.e. energy intake per unit time. Qualitative traits seem to be important only for specific taxa. For example, toxins or poor digestibility may be responsible for the avoidance of heteropterans, beetles and ants and for feeding the nestlings fewer tipulids than expected at high tipulid densities.

Agar as a gelling agent: chemical and physical analysis

Agars with different performance in bioassays were analysed for physical and chemical properties. Agars with the highest gel strength had the best performance. Good performance was also related to a low pH of a suspension of agars and to a low sulphur content. The diffusion rate of ions in gels differed between agars, but could not explain differences in agar performance. The time of autoclaving had a marked effect on the gel strength, however, without affecting the performance. Chemical analysis revealed large differences between agars. The best agars had a relatively low salt content. One of the best agars had an extremely high content of trace elements. Agar impurities, especially of the trace elements were tightly bound to the agars. Up to 30% of the Murashige and Skoog (MS) salts were also immobilized in the gel. At pH 4.2, less nitrogen and phosphate were available from the MS medium than at pH 5.7. Chlorine could be washed out completely and appeared to be a good marker for agar quality and purity. With AgNO₃, chlorine contamination could easily be visualized.

Disparate determinants of summer and winter diet selection of a generalist herbivore, Ochotona princeps

The North American pika, Ochotona princeps, is a generalist herbivore that simultaneously selects two distinct diets: one consumed immediately (summer diet), the other harvested, transported, and stored for later consumption (winter diet). I investigated factors influencing diet selection at two sites on the West Knoll of Niwot Ridge, Boulder County, Colorado during 1991 and 1992. The composition of summer and winter diets differed significantly from each other as well as from the relative abundance of food items in the environment. Thus, pikas were not foraging randomly for either diet. To explore winter and summer diet selection, I tested two existing hypotheses: (1) that plant morphology restricts the winter diet breadth to plants that are easily harvested and large, and thereby maximizes the amount collected per foraging effort, or (2) to compensate for nutrients lost during storage, pikas bias their winter diet with high-nutrient species. I also tested the hypothesis that plant secondary compounds may be higher in the winter diet either because they function as preservatives or because pikas delay consumption of these species until the toxins degrade. For individual dietary items, I measured energy, nitrogen, water, fiber, total phenolic, condensed tannin, and astringency contents. There was little evidence to suggest that morphology excluded plants from the winter diet. Plant size was not a good predictor of abundance in the winter diet. Even after harvesting costs had been experimentally removed, cushion plants were still not included in the winter diet. There was weak support for an effect of nutrients on winter diet selection; in three of four cases, the winter diet was significantly lower in water and higher in total energy content as predicted by the nutrient compensation hypothesis. However, other nutrients exhibited no consistent pattern. Nutrients were not reliable predictors of the winter diet in multiple regression analyses. There was strong support for the hypothesis of manipulation of secondary compounds. The winter diet was significantly higher in total phenolics and astringency. Total phenolics were consistent predictors of the winter diet in multiple regression analyses. The winter diets of six additional pika populations contained plant species high in secondary compounds. The results suggest that pikas preferentially select plants with high levels of secondary compounds for their winter diet, possibly because the presence of such compounds promotes preservation of the cache. This behavior may also enable the exploitation of an otherwise unusable food resource, i.e., toxic plants.