نتایج جستجو برای: trophic indices
تعداد نتایج: 97826 فیلتر نتایج به سال:
The regulation of an asexual population of the oleander scale [Aspidiotus nerii Bouchè (Hemiptera: Diaspididae)] on California bay tree [Umbellularia californica (Hopk. & Arn.) Nut.] by two natural enemies; an idiobiont, ectoparasitoid Aphytis chilensis Howard (Hymenoptera: Aphelinidae) and a coccinellid predator (Rhysobius lophanthae (Blaisd.) (Coleoptera: Coccinellidae), was examined using a ...
Mercury (Hg) depuration into growing feathers is a well-studied phenomenon in waterbirds. Although the kinetics of Hg excretion in relation to molt and diet has been studied extensively, the relationship between the individual nutritional condition of nestlings and dietary Hg accumulation has not been investigated. In the present study, a body-condition index (BCI) and nutritional condition ind...
BACKGROUND Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to ...
Most young fishes lack the ability to function as herbivores, which has been attributed to two aspects of the digestive system: elevated nitrogen demand and a critical gut capacity. We compared the digestive morphology and biochemistry of two size classes of the marine herbivore Hyporhamphus regularis ardelio, pre-ontogenetic trophic shift (pre-OTS, <100mm) and post-ontogenetic trophic shift (p...
The effect of short-term infusion of a large dose of pentagastrin and a small dose of synthetic human gastrin I (SHG) on the rate of cell proliferation in gastric mucosa was studied in normal human subjects. Moreover, the kinetic parameters were compared with the serum gastrin concentrations in fasting patients. Endoscopic biopsies were labelled in vitro with 3H-thymidine and autoradiographs we...
This paper compares the Portuguese and Bulgarian consumer price indices (CPI) and attempts to identify some areas in which the CPI compilation methodology could be improved in the two countries. This work is organised into six sections. The first section briefly describes the organisational structure on which the production of the CPI is based in the two countries. The second section focuses on...
1. Quantitative food web analysis is made difficult by the need for simultaneous measurement of multiple carbon (C) flows. C flow rates can potentially be quantified indirectly using conventional methods such as gut contents analysis, but the involvement ofmany conversion factors and assumptions results in significant errors in the final estimation. Such difficulties have limited quantitative d...
Small pelagic fish (SPF) are key organisms for the functioning of marine ecosystems. In recent decades, these species have undergone significant changes in biomass, growth and body condition Mediterranean Sea. Seasonal spatial information about biological ecological traits SPF their relationship with environmental variables is still missing. Here, we investigated along a latitudinal gradient No...
The aim of this investigation was to assess the differences in terms α-diversity, species composition and trophic structure between peracarid assemblages inhabiting artificial hard substrates those present on natural ones at two sites Western Mediterranean Sea. In each one, samples were collected from substrates, extracted peracarids identified level. Each sample characterised by its Total Abun...
eutrophication is known as the most common problem in water bodies, caused by high concentrations of different nutrients leading to unbalanced growth of aquatic plants, among other symptoms. hence, the possibility of eutrophication prediction can be beneficial to the sustainable management of these natural resources and create an opportunity to control their trophic conditions over time. a soft...
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