Search results for "Nutrient"
showing 10 items of 668 documents
The importance of dead seagrass (Posidonia oceanica)matte as a biogeochemical sink
2022
We assessed the potential of dead seagrass Posidonia oceanica matte to act as a biogeochemical sink and provide a coherent archive of environmental change in a degraded area of the Mediterranean Sea (Augusta Bay, Italy). Change in sediment properties (dry bulk density, grain size), concentration of elements (Corg, Cinorg, N, Hg) and stable isotope ratios (δ13C, δ 15N) with sediment depth were measured in dead P. oceanica matte and unvegetated (bare) sediments in the polluted area, and an adjacent P. oceanica meadow. Principal Component Analysis (PCA) revealed a clear clustering by habitat, which explained 72% of variability in our samples and was driven mainly by the accumulation of N and H…
Effects of stump removal on soil decomposer communities in undisturbed patches of the forest floor
2011
Soil preparation after clear-cutting leads to fragmentation of forest floor and, consequently, changes the habitat of decomposers. Stump removal for bioenergy is further increasing the disturbance in the soil. We studied responses of decomposers to stump removal in boreal spruce forests during the first 4 years after clear felling in relation to mounding. Samples for each decomposer organism group were taken from undisturbed forest floor patches that are the main habitat for decomposers after forest regeneration and whose amount and size obviously differ between the treatments. Microbial biomasses and community structure, and the abundance of enchytraeids, were not found to be affected by t…
Overview of methods used to evaluate the adequacy of nutrient intakes for individuals and populations
2009
The objective of the present paper is to review the methods of measuring micronutrient intake adequacy for individuals and for populations in order to ascertain best practice. A systematic review was conducted to locate studies on the methodological aspects of measuring nutrient adequacy. The results showed that for individuals, qualitative methods (to find probability of adequacy) and quantitative methods (to find confidence of adequacy) have been proposed for micronutrients where there is enough data to set an average nutrient requirement (ANR). If micronutrients do not have ANR, an adequate intake (AI) is often defined and can be used to assess adequacy, provided the distribution of dail…
Effects of feeding frequency on growth and food utilisation of rainbow trout (Oncorhynchus mykiss) fed low-fat herring or dry pellets
1998
Abstract One-year-old rainbow trout (weight range 400–700 g) were fed for 18 weeks on low-fat herring or commercial dry pellets 1, 2 or 4 times in a day. Quadratic regression analysis indicated that at least three feedings were required for maximum growth and that fish fed a dry diet could benefit from even more frequent feeding. The proportion of lipid in growth increased with increased number of feedings, but the protein content was not affected (mean 18.6% protein wet basis). Food consumption (dry weight) was affected in a similar manner for both diets and its maximum occurred at slightly higher frequency than for maximum growth. No effects of feeding frequency or type of diet on energy …
Review on Physiological Effects of Vermicomposts on Plants
2020
Vermicompost is a type of organic fertilizer produced by earthworms and their symbiotic microorganisms. In addition to nutrient-rich organic fraction, vermicomposts also contain plant-available soluble minerals as well as substances with plant growth-regulating activity. In order to promote understanding on beneficial effects of vermicompost in different farming systems, the aim of the present review is to analyze possible mechanisms of vermicompost action on plants. After overview of plant growth-affecting activity of vermicomposts at the level of seed germination and vegetative growth, detailed analysis is dedicated to physiological effects associated with mineral nutrition: changes in bo…
Dietary Patterns and Healthy Ageing
2021
Ageing is a complex process in which multiple factors are involved that can contribute to determine whether a person will or not be affected by diseases that are more frequently observed in advanced age. The factors involved comprise genetic, environmental, behavioural, and dietary factors, which influence pathways that regulate the ageing process and the life expectancy, rendering longevity a multifaceted phenomenon. Even if a miraculous elixir or pill is not yet available, there is general agreement that nutrition has a major impact on the overall mortality and on the development of age-related chronic non-communicable diseases. Nutrition research has focused for decades on single nutrien…
DETERMINATION OF MACRO ELEMENTS IN GLUTEN-FREE FOOD FOR CELIAC PEOPLE BY ICP-OES
2015
This paper is the first analytical approach to the study of seven nutrients in the gluten-free foods for celiac people. The ICP-OES technique was used. One of the advantages about the use of ICP-OES for this characterization is the high selectivity and low interferences for studied elements. The concentration values of K, Li, Sr, Na, Ca, Mg and Al in seventeen gluten-free food samples are reported. Considering the average concentrations of the elements analyzed, excluding lithium, in the present study it can be concluded that they are inadequate if compared with the recommended daily intake by international organisms, providing only from 1.5 to 20% of the RDI for the essential metals. In pa…
RAVITA Technology : new innovation for combined phosphorus and nitrogen recovery
2018
Abstract Present phosphorus (P) recovery technologies mainly contain P recovery from sludge liquor or ash. These types of technologies are suitable for large wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR), digestion and/or incineration. In Finland and other Nordic countries, strict P discharge limits require chemical precipitation, thus EBPR alone is not sufficient. Ammonium recovery from wastewater, on the other hand, is not so often discussed. However, recovery from WWTP reject waters would decrease the energy demand of ammonium synthesis by Haber-Bosh technology and the energy demand of the WWTP's biological process. Helsinki Region Environmental S…
Influence of nitrogen status in wine alcoholic fermentation
2019
Nitrogen is an essential nutrient for yeast during alcoholic fermentation. Nitrogen is involved in the biosynthesis of protein, amino acids, nucleotides, and other metabolites, including volatile compounds. However, recent studies have called several mechanisms that regulate its role in biosynthesis into question. An initial focus on S. cerevisiae has highlighted that the concept of "preferred" versus "non-preferred" nitrogen sources is extremely variable and strain-dependent. Then, the direct involvement of amino acids consumed in the formation of proteins and volatile compounds has recently been reevaluated. Indeed, studies have highlighted the key role of lipids in nitrogen regulation in…
The ambiguous role of 2,4-dichlorophenoxyacetic acid in wheat tissue culture
1986
The very basal, highly immature regions of dissected young leaves of Triticum aestivum L. cv. Kite formed adventitious roots on a nutrient medium supplemented with comparatively low concentrations (0.16 to 0.63 μM) of 2,4-dichlorophenoxyacetic acid (2,4-D). Higher concentrations (up to 640 μM) had to be applied to stimulate growth from more mature regions higher up the leaf. Yet, already at 2.5 μM roots were less distinct and more callus-like, and eventually (at 10 to 640 μM) only a subculturable callus of apparently suppressed, slowly proliferating root primordia developed. Furthermore, at the most basal, highly immature regions growth was significantly retarded when the auxin concentratio…