The aim of this study was to assess the eutrophication and trophic status of the Caspian Sea based on different indices and also compare its status with the reference threshold values in the Iranian coastal waters of Caspian Sea (hereafter ICWCS). The water samples (three replicates) were collected along four transects (off the coast from Anzali, Tonekabon, Nowshahr and Amirabad) between spring...

Trophic dynamics (community composition and feeding relationships) have been identified as important drivers of methylmercury (MeHg) bioaccumulation in lakes, reservoirs, and marine ecosystems. The relative importance of trophic dynamics and geochemical controls on MeHg bioaccumulation in streams, however, remains poorly characterized. MeHg bioaccumulation was evaluated in eight stream ecosyste...

the parameters used to determine the trophic state of a water body are: total phosphorus (tp),transparency (secchi disk depth) and chlorophyll a. however, these parameters show strong seasonalfluctuations which may hinder the estimation of trophic state. some authors have proposed that sediments be used as an additional tool to evaluate the trophic state of a water body. the aim of this study w...

Samples of agricultural soils were collected across North Carolina in 1992 and Nebraska in 1993 to determine which indices of nematode communities could be applied to distinguish ecological pattern at regional geographic scales. Sampling density was proportional to the area of agriculture in each region of each state. Maturity indices (based on life-history characteristics) were calculated to d...

The application of stable isotope analysis (SIA) has become a standard scientific approach in Agricultural and Ecological researches and, more in general, in several disciplines such as biology, botany, zoology, organic chemistry, climatology, and nutrition. The main objectives of this paper are (1) to provide a simple definition of stable isotopes and (2) to illustrate analytical measurement m...

The bioaccumulations of metals Cu, Cd, Ni, Cr, Co, Mn, Zn and Fe were measured in bivalves, Cerastoderma glucaum, and four species of fishes including Alburnus chalcoides, Liza aurata, Rutilus frisii and Sander lucioperca from various trophic levels of the Caspian food web. The concentrations of Cd, Cr, Co and Ni in most samples of fish were below the detection limits; while the concentrations ...

OBJECTIVE To evaluate the effect of initial low energy permissive underfeeding ("trophic feeding") versus full energy enteral feeding ("full feeding") on physical function and secondary outcomes in patients with acute lung injury. DESIGN Prospective longitudinal follow-up evaluation of the NHLBI ARDS Clinical Trials Network's EDEN trial SETTING 41hospitals in the United States. PARTICIPAN...

Feedbacks within ecosystems can lead to internal reinforcement of the current state providing ecosystem resilience. Often, multiple biotic interactions across trophic levels play a role in such feedbacks, yet these are generally studied independently, obscuring relative importance among different factors. We look at various potential feedbacks intact and degraded mesic forests on Hawai?i Island...

The bioaccumulations of metals Cu, Cd, Ni, Cr, Co, Mn, Zn and Fe were measured in bivalves, Cerastoderma glucaum, and four species of fishes including Alburnus chalcoides, Liza aurata, Rutilus frisii and Sander lucioperca from various trophic levels of the Caspian food web. The concentrations of Cd, Cr, Co and Ni in most samples of fish were below the detection limits; while the concentrations ...