2021 ◽  
Vol 26 (1) ◽  
pp. 2269-2274
Author(s):  
IOAN PĂCEŞILĂ ◽  
EMILIA RADU

Phosphorus is one of the most important inorganic nutrients in aquatic ecosystems, the development and functioning of the phytoplankton communities being often correlated with the degree of availability in assimilable forms of this element. Alkaline phosphatase (AP) is an extracellular enzyme with nonspecific activity that catalyses the hydrolysis of a large variety of organic phosphate esters and release orthophosphates. During 2011-2013, AP Activity (APA) was assessed in the water column and sediments of several aquatic ecosystems from Danube Delta: Roșu Lake, Mândra Lake and their adjacent channels – Roșu-Împuțita and Roșu-Puiu. The intensity of APA widely fluctuated, ranging between 230-2578 nmol p-nitrophenol L-1h-1 in the water column and 2104-15631 nmol p-nitrophenol g-1h-1 in sediment. Along the entire period of the study, APA was the most intense in Roșu-Împuțita channel, for both water and sediment samples. Temporal dynamics revealed its highest values in summer for the water column and in autumn for sediment. Statistical analysis showed significant seasonal diferences of the APA dynamics in spring vs. summer and autumn for the water column, and any relevant diferences for sediment.


The Holocene ◽  
2021 ◽  
pp. 095968362110191
Author(s):  
Luminița Preoteasa ◽  
Alfred Vespremeanu-Stroe ◽  
Anca Dan ◽  
Laurențiu Țuțuianu ◽  
Cristian Panaiotu ◽  
...  

This paper documents the Late-Holocene environmental changes and human presence in the northern Danube delta using a multidisciplinary approach that combines geoscientific data with archaeological findings, historical texts, and maps. It follows the formation and progression of the Chilia distributary and the reconfiguration of socioeconomic activities. Sedimentary facies identified on five new cores by changes in texture properties, magnetic susceptibility, geochemistry, and macro- and microfauna composition together with the newly obtained chronology constrain the complex evolution of the Chilia branch as filling in a long-lasting bay and then of a giant lagoon (Thiagola) which covered most of the northern delta since the Old Danube lobe inception (ca. 7500 yrs BP) till modern Chilia development. It initiated during the Greek Antiquity (ca. 2500 yrs ar BP) at the delta apex, while in Roman times (ca. 1800 yrs BP) it pursued its slow flowing into the vast Thiagola Lagoon. The most dramatic transformations occurred in the last 800 years when the river passed east of the Chilia promontory, rapidly went through the present-day Matița-Merhei basin (several decades), and created its first open-sea outlet. Solid discharge increased in two distinct periods, once in the Middle Ages (ca. 750 yrs BP) and then in the Modern Period (ca. 150 yrs BP) due to human-induced land-use changes in the Danube watershed. The chronology of the cultural remains on the pre-deltaic Chilia promontory and the multiproxy analysis of a sediment core retrieved nearby downstream suggest the terrestrial connection of the island with the mainland in ancient times. The hitherto contended issue of the old Thiagola Lagoon and its location are redefined here, as are the original identifications of ancient and medieval toponyms and hydronyms, especially for Chilia-Licostomo, Byzantine, Genoese, Moldavian, Ottoman, and Russian trading point of great importance in the political and economic history of the Black Sea and neighboring regions.


Hydrobiologia ◽  
2021 ◽  
Author(s):  
Maria Iasmina Moza ◽  
Carmen Postolache ◽  
Ana Maria Benedek ◽  
Mirela Moldoveanu ◽  
Piet Spaak

2017 ◽  
Vol 19 (2) ◽  
pp. 231-251 ◽  
Author(s):  
Andrew Biro

The market for bottled water is growing and increasingly segmented. How do we explain not just the willingness to pay for a substance (water) that is almost free but also the increasing discernment in a drink generally considered tasteless? We argue that bottled water market segmentation is a leading edge of processes of water commodification, associated with the crisis of Fordism and rise of consumerist capitalism, where the assertion of status through commodity consumption is increasingly necessary. The extensive Ray’s & Stark water menu is analyzed to show how the taste for bottled waters is cultivated. In the menu, references to gustatory sensation are limited. Instead, the tastefulness of water inheres in the distance from anthropogenic influence, made visible through scientific (geological) discourses. The tension between the desire to consume unmediated nature and the scientific abstraction necessary to recognize it reveals the social character of the taste for bottled waters. The highly refined sense of taste that the water menu’s readers are presumed to have is a reflection of consumerist capitalism’s distinctive ways of reproducing socio-economic inequality and metabolizing non-human nature.


2014 ◽  
Vol 41 (23) ◽  
pp. 8429-8437 ◽  
Author(s):  
F. Alexander Haumann ◽  
Dirk Notz ◽  
Hauke Schmidt

2014 ◽  
Vol 50 (4) ◽  
pp. 972-975 ◽  
Author(s):  
Miruna Oltean ◽  
Zsuzsa Kalmár ◽  
Botond J. Kiss ◽  
Mihai Marinov ◽  
Alexe Vasile ◽  
...  
Keyword(s):  

2007 ◽  
Vol 9 (2) ◽  
pp. 210
Author(s):  
Ileana Prejbeanu ◽  
Cornelia Rada
Keyword(s):  

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