نتایج جستجو برای: calcareous algae
تعداد نتایج: 22380 فیلتر نتایج به سال:
Predictions concerning the consequences of the oceanic uptake of increasing atmospheric carbon dioxide (CO2) have been primarily occupied with the effects of ocean acidification on calcifying organisms, particularly those critical to the formation of habitats (e.g. coral reefs) or their maintenance (e.g. grazing echinoderms). This focus overlooks direct and indirect effects of CO2 on non-calcar...
The avalanche statistics in porous materials and ferroelastic domain wall systems has been studied for slowly increasing compressive uniaxial stress with stress rates between 0.2 and 17 kPa s-1. Velocity peaks [Formula: see text] are calculated from the measured strain drops and used to determine the corresponding Energy distributions [Formula: see text]. Power law distributions [Formula: see t...
Productivity in P limited peatlands is regulated in part by the turnover of organic phosphates, which is influenced by the chemical nature of the compounds involved. We used solution 31P nuclear magnetic resonance (NMR) spectroscopy to quantify organic and inorganic phosphates in benthic floc (a mixture of plant detritus and algae) and underlying soil from sites along P gradients in hard water ...
The genus Haplosyllides was considered as monotypic, with H. floridana as the only valid species. The present revision Includes two more species in this genus: H. aberrans comb. nov. and H. ophiocomae sp. nov. Syllis (Haplosyllis) aberrans (from Vietnam) was considered a Junior synonym of H. floridana (from the Caribbean). The finding of additional specimens from Vietnam and Indonesia, and the ...
The abundance of reef builders, non-builders and the calcium carbonate produced by communities established in Calcification Accretion Units (CAUs) were determined in three Abrolhos Bank shallow reefs during the period from 2012 to 2014. In addition, the seawater temperature, the irradiance, and the amount and composition of the sediments were determined. The inner and outer reef arcs were compa...
Calcareous skeletons evolved as part of the greater Ediacaran/Cambrian diversification of marine animals; however, skeletons did not become permanent, globally important sources of carbonate sediment until the Ordovician radiation. Representative carbonate facies in a Series 3 Cambrian to Tremadocian succession from western Newfoundland and Ordovician successions from the Ibex area, Utah, show ...
Biomineralization is a complex combination of biochemical and physiological processes, depending on endogenous activity of an organism and the exogenous environmental influence. In marine organisms (bacteria, calcareous algae, molluscs, crustaceans, fish and mammals) biomineralization starts at early stages of development and continues during the entire life. These processes take place in diffe...
Background & Aim: In this study, is done during one-year research on blue–green and green algae for antimicrobial activity in Mashhad suburb. Aqueous, ether, and methanol extracts from 44 species blue – green algae and green algae were examined for antimicrobial properties against four bacteria (tow positive gram bacteria and tow negative gram bacteria) and tow fungous. Material & Methods: Amo...
Surface ocean pH is likely to decrease by up to 0.4 units by 2100 due to the uptake of anthropogenic CO2 from the atmosphere. Short-term experiments have revealed that this degree of seawater acidification can alter calcification rates in certain planktonic and benthic organisms, although the effects recorded may be shock responses and the long-term ecological effects are unknown. Here, we show...
The stratigraphic framework of the uppermost Jurassic Lower Cretaceous interval of the Gulf area is revised using both historical and recently acquired paleontological (ammonites, calpionellids, foraminifers, 'calcareous' algae), sedimentological and sequential information. The Kahmah regional Series ranging in age from Late Tithonian to Gargasian (= middle Aptian) times is subdivided into regi...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید