نتایج جستجو برای: nutrient

تعداد نتایج: 68621  

2016
Jean-Philippe Côté Shawn French Sebastian S. Gehrke Craig R. MacNair Chand S. Mangat Amrita Bharat Eric D. Brown

Conventional efforts to describe essential genes in bacteria have typically emphasized nutrient-rich growth conditions. Of note, however, are the set of genes that become essential when bacteria are grown under nutrient stress. For example, more than 100 genes become indispensable when the model bacterium Escherichia coli is grown on nutrient-limited media, and many of these nutrient stress gen...

Journal: :Trends in ecology & evolution 1994
D J Lodge W H McDowell C P McSwiney

Recent research shows that nutrient fluxes are often pulsed In tropical forests, and that pulsed versus gradual inputs have different effects on the fates of nutrients in the ecosystem. Synchrony of nutrient mineralization with plant uptake can lower competition between microbes and plants for limiting nutrients while maintaining tight nutrient cycling, whereas asynchrony can lead to losses of ...

1999
C. LISA DENT NANCY B. GRIMM

Nutrient availability in ecosystems is patchy both in space and in time. Whereas temporal trends have often been studied, less information exists on spatial patterns of nutrient availability, particularly in aquatic ecosystems. The goals of this study were (1) to describe and quantify patterns of nutrient concentration in surface waters of an arid land stream and (2) to compare spatial patterns...

1998

Recent investigations of nutrient-limited productivity in coral reef macroalgae have led to the conclusion that phosphorus, rather than nitrogen, is the primary limiting nutrient. In this study, comparison of the dissolved inorganic nitrogen:phosphorus ratio in the water column of Kaneohe Bay, Hawaii, with tissue nitrogen:phosphorus ratios in macroalgae from Kaneohe Bay suggested that nitrogen,...

2009
Barbara Hayford Donald Huggins Debra Baker Michael Johnson

SUMMARY 1. Large scale classifications such as nutrient ecoregions have been established in the United States to help regulate surface water resources. These classifications and their constituent classes are hypotheses which may be tested by establishing the strength of the classes to differentiate within class and between class variation. The purpose of our study was to test the strength of th...

ژورنال: پژوهش در پزشکی 2006
فریدون عزیزی, , فیروزه حسینی, , لیلا آزادبخت, , پروین میرمیران, ,

Background: The present study was conducted to examine the relationship between variety scores of food groups and specific nutrient adequacy in Tehranian adult men. Materials and methods: In this cross-sectional study, 295 men aged 18 years and over were included. We assessed food intake by two 24-hour recalls questionnaires. Two different dietary diversity indices dietary diversity score (DDS...

Journal: :Frontiers in plant science 2016
José M. Leite Ignacio A. Ciampitti Eduardo Mariano Michele X. Vieira-Megda Paulo C. O. Trivelin

Unraveling nutrient imbalances in contemporary agriculture is a research priority to improve whenever possible yield and nutrient use efficiency in sugarcane (Saccharum spp.) systems while minimizing the costs of cultivation (e.g., use of fertilizers) and environmental concerns. The main goal of this study was therefore to investigate biomass and nutrient [nitrogen (N), phosphorus (P), and pota...

Amin Javan Ouchbolagh Rahim Nagshiband Hassani Saadollah Alizadeh Ajirlo, Seyed Jalal Tabatabaei

An experiment was conducted to investigate the effects of K/Ca ratios of nutrient solution on physiological traits, cut flower vase life and postharvest changes of rose. The main experiment was factorial based on completely randomized design with two cvs. of rose (Magic Red and Capitol), five K/Ca ratios in the nutrient solution (4:4, 6:4, 6:3, 8:3, 10:2) and three replications. Increasing the ...

Ismail, M.R, Kamarudin , M.S, Rafiee, Gh.R, Ros Saad, Ch, Sijam, K,

Effects of supplementary nutrient in the production of red tilapia (Oreochromis sp) and Lettuce (Lactuca sativa var longifolia) evaluated in a representative water recirculating aquaculture system. The nutrient solution supplemented was 25% level of (L25) nutrient solution as medium used for aquaponic production of lettuce in the NFT system (based on cooper’s formula). Thus, a completely random...

2012
J. M. S. Franz H. Hauss U. Sommer T. Dittmar U. Riebesell

Oxygen-deficient waters in the ocean, generally referred to as oxygen minimum zones (OMZ), are expected to expand as a consequence of global climate change. Poor oxygenation is promoting microbial loss of inorganic nitrogen (N) and increasing release of sediment-bound phosphate (P) into the water column. These intermediate water masses, nutrient-loaded but with an N deficit relative to the cano...

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