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The Colentina River is a tributary of the Dâmbovița River in Romania, flowing through the city of Bucharest before joining the main river. It has been significantly altered by human activities, including river course fragmentation, shoreline modification, and exposure to various pollutants from local sources. Macrophytes, which are crucial biotic components, are significantly influenced by human activities. They play several important roles in lakes, such as enhancing water transparency, absorbing nutrients and carbon dioxide, and providing habitats for diverse species. This study aims to assess the structural aspects of two primary producer components (macrophytes and phytoplankton) in different sections of the Colentina River. A specific methodology was employed to evaluate macrophytes and phytoplankton, considering three habitat variables: rural, peri-urban, and urban. The principal findings indicated that anthropogenic pressures have shaped the taxonomic structure. The spatial distribution of macrophytes was found to be correlated with both the geomorphology and water quality of the ecosystems. Peri-urban and rural areas, closer to natural conditions, support greater macrophyte diversity compared to urban areas. Extended periods of eutrophication have resulted in significant growth of Chlorophyceae and Cyanobacteria, negatively impacting the ecological conditions that support macrophytes. Despite these adverse interactions, certain plants, such as Phragmites australis and Typha angustifolia, have demonstrated adaptability and resilience, occupying niches even in hypereutrophic waterbodies. The varying levels of urbanization along the Colentina River have led to ecological degradation, characterized by a decline in macrophyte and phytoplankton diversity and an increase in pollution-resistant species. This highlights the urgent need for sustainable management strategies to mitigate human impacts and preserve ecosystem health. [ABSTRACT FROM AUTHOR]

Carried out with six elementary school teachers, this action research aimed to co-construct and implement differentiated pedagogical practices in writing to students from disadvantaged backgrounds. This text presents the results of the training component (Guay & Prud'homme, 2018) of this action research and documents the effects of the participation of teachers in this study on their professional development. The results show achievements in all dimensions of the Clarke and Hollingsworth (2002) model. The analysis of the cost/benefit ratio and the sustainability of the achievements puts into perspective the conclusion on the effectiveness of this type of professional development device. Keywords: differentiated instruction, action research, writing teaching, professional development, relationship to writing Realisee aupres de six enseignantes du primaire, cette recherche-action visait a coconstruire et a mettre en oeuvre des pratiques differenciees d'enseignement de l'ecriture aupres d'eleves de milieux defavorises. Cet article presente les resultats du volet formation (Guay et Prud'homme, 2018) de cette recherche-action et decrit les effets de la participation d'enseignantes a cette etude sur leur developpement professionnel. Les resultats montrent des acquis dans toutes les dimensions du modele de Clarke et Hollingsworth (2002). L'analyse du rapport couts/retombees et de la perennite des acquis met en perspective la conclusion sur l'efficacite de ce type de dispositif de developpement professionnel. Mots-cles: pedagogie differenciee, recherche-action, enseignement de l'ecriture, developpement professionnel, rapport a l'ecriture, Problematique Les chercheurs, les praticiens et les decideurs s'accordent pour souligner l'importance du developpement professionnel des enseignants (Mukamurera et al., 2014) et de ses retombees sur la reussite des eleves [...]

Urban areas face numerous provocations, such as air, water, and soil contamination. Additionally, urban lakes have numerous beneficial services that contribute to urban sustainability. In urban aquatic ecosystems, X-ray fluorescence can provide complex answers regarding the presence of elements associated with environmental risk. The study aimed to screen the elements with different potentials (critical raw materials—CRMs; toxic; potentially toxic) from Phragmites australis leaves along the Colentina urban river. The samples from the peri-urban and urban river courses highlighted the presence of elements with different potentials for ecosystems and human health. The investigated stations were influenced by regional anthropogenic pressures, where P. australis highlighted the absorption of the dominant elements found in the environment. From the total of 56 elements present in the samples, some have structural roles (K, Si, Ca, and Cl), some are from the CRM category, and some are airborne heavy metals and rare metals. Furthermore, among CRMs, cesium, lanthanum, magnesium, phosphorus, vanadium, sulfur, holmium, and titanium were recorded with higher values. Although the values of the elements in the anthropogenic source were in low concentrations, spatial differences were highlighted. The stations in agricultural areas were different from the peri-urban and urban ones. [ABSTRACT FROM AUTHOR]

This study analyzed the metabolic potential of some functional groups of bacteria in aquatic urban systems and evaluated the abundance of communities of total heterotrophic bacteria in the water in relation to the monitored physico-chemical factors. The results obtained showed seasonal differences, especially in spring. The high values of the abundance of heterotrophs in winter are related to human activity at the sampling stations. Screening for four types of extracellular hydrolytic enzyme with potential for degradation of organic matter (amylases, lipases, proteases and cellulases) led to the conclusion that lipolytic bacteria were dominant in the studied ecosystems, while proteolytic bacteria were observed in low numbers, but were present in urbanized areas. The presence of cellulolytic bacteria is correlated with the development of macrophytic vegetation. The aim of the present study was oriented towards the evaluation of the anthropogenic input in several lakes surrounding Bucharest in the Nord-Eastern region. These urban ecosystems are generated as a requirement of city development. The microbiological and general enzymatic approaches generated some novel results concerning the pollution degree of aquatic urban ecosystems and could be considered as a platform for further investigation. [ABSTRACT FROM AUTHOR]

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The present paper deals with the seasonal dynamics of microbial communities in Letea saline lake which is located nearby of the village with the same name by classical microbiological methods. The chloride content is variable, with values from 8.9 g/L (spring of 2018) up to 38.3 g/L (autumn of 2017). There are different similarities between the values obtained over seasons. Thus, in the spring of 2017, an average of 11.8 g/L was obtained, a value close to that obtained in the spring of 2018 (8.9 g/L). The average of chlorides in autumn 2016 (25.5 g/L) is relatively different to the autumn of 2017 (38.3 g/L). During the autumn of 2016 and spring of 2018, the dynamics of several microbial communities was assessed as follow: heterotrophic, sulphate reducing, ammonifying and denitrifying bacteria respectively. The recorded results revealed that the best represented communities appear to be ammonifying bacteria, being high in the spring months. Denitrifying bacteria have registered high values in autumn 2017 and sulphate reducing bacteria in April 2017. The dynamics of halophilic bacteria were also recorded and more than 100 strains were randomly selected for purification, characterization and extracellular enzymatic activity analyses for the future biotechnological applications. [ABSTRACT FROM AUTHOR]

The study was conducted in several natural saline lakes from the Buzău and Brăila counties (Romania). The Lakes Câineni, Balta Albă and Amara are hyposaline, only the Lake Movila Miresei can be considered as hypersaline according to mineral content. The aim of the study was to have an quantitative approach to the biological structure of the lakes in relationship with abiotic factors, mainly salinity. Using the Principal Component Analysis (PCA), the Lake Movila Miresei was associated with salinity and conductivity, the Lake Câineni with temperature, while Balta Albă and Amara were influenced mainly by DO, pH, TDS, ORP, turbidity. The level of primary producers was represented by four groups of phytoplankton and the highest species richness was registered in Lake Amara (38 species), with low salinity. The zooplankton community showed a species richness significantly smaller than phytoplankton, even if it presented species belonging to several taxonomic groups (9). The high zooplankton diversity of the Lake Amara was correlated with low salinity. The Shannon index decreasead with the reduction of salinity in the other three lakes. It is noteworthy the presence of Artemia salina Linnaeus 1758, both in the Lakes Amara and Movila Miresei, known as indicator species of therapeutic mud. The additional technique applied for investigating the diversity of the phytoplankton confirmed the values of Shannon's diversity index and infirmed the values of the species richness trend. Thus, the Lake Câineni (with high salinity, second after Movila Miresei) held the first place in terms of diversity, the second was Balta Albă, and the less diverse were Amara and Movila Miresei. The Amara Lake experienced an cyanobacterial bloom event, with Oscillatoria tenuis Agardh 1813. We conclude that salinity not always is the main factor shaping the diversity of saline lakes. Other factors, such as temperature, DO, pH, TDS, ORP, turbidity can influence the biological communities of these lakes. [ABSTRACT FROM AUTHOR]

Copyright of Oltenia, Studii si Comunicari Seria Stiintele Naturii is the property of Museum of Oltenia Craiova and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rotifers are known as cosmopolitan organisms, found in high density in most waters, often representing the dominant group in terms of species diversity and abundance in the zooplankton community. Since the functionality of an ecosystem is closely related to the diversity of communities, analysis of rotifers assemblage may be a useful tool in understanding the mechanisms of the spatial and temporal changes on this level. Data were collected from 2008 until 2010, in distinct areas of Danube, Sfântu Gheorghe branch with different degrees of human impact. Sfântu Gheorghe river branch has distinct features conferred by the construction of new canals and cutting off the meanders. Due to these regularization changes, a complex of ecosystems with different features resulted. The impact of engineering may determine a reduction in species diversity and abundance in the new ecosystems. The canals of Sfântu Gheorghe branch presented the lowest value of the species richness and diversity indices in comparison with the other two areas. The constant species belong to Brachionus, Keratella, Asplanchna, Synchaeta genus. The branch environmental conditions allow the development loricate species and soft-bodied type, the dominant species belonging to Brachionidae family. This study reveals a close resemblance between natural sectors and meanders in terms of diversity and abundance of the rotifer assemblage. Opposites, in the newly created canals, the species richness and abundance registered a decreasing reflecting the impact of human interventions on the ecological system. [ABSTRACT FROM AUTHOR]

Copyright of McGill Journal of Education is the property of McGill Journal of Education and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)