scholarly journals Environmental conditions of alpine springs of the upper Po River (NW Italy) on the basis of their epilithic diatom communities

2012 ◽  
Vol 153 (1) ◽  
pp. 49
Author(s):  
Maurizio Battegazzore

Diatom (Bacillariophyceae) assemblages were sampled in 7 springs in the upper part of the River Po basin in the summer of 2010. Four springs are situated in the mountainous part of the study area while three are in the lowland plain. Chemical-physical variables were measured and analyzed in water samples of 6 springs. 101 diatom species were identified in the surveyed springs, with species richness ranging from 12 to 52. <em>Gomphonema nathorstii</em>, described for arctic regions, was found in Italy for the first time. Multivariate statistical analysis was undertaken to link taxonomical and environmental data, and indicated the existence of three distinct environmental features, each one characterized by prevalent diatom species: 1) low pH and high dissolved oxygen, 2) both high pH and dissolved oxygen and 3) high levels of silica and conductivity.

2011 ◽  
Vol 70 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Ali Soltanpour-Gargari ◽  
Martin Lodenius ◽  
Friedel Hinz

Epilithic diatoms (Bacillariophycae) from streams in Ramsar, Iran Epilithic diatoms were identified from five small streams and one canal in Ramsar, northwest Iran. Atotal of 155 diatom taxa belonging to 37 genera were found and only two species remained unidentified (Fragilaria sp. and Nitzschia sp.). Achnanthes, Nitzschia, Navicula, Cocconeis, Melosira, Amphora, Craticula, Diatoma, Surirella, Cymbella, Diploneis and Entomoneis were among the most abundant genera. Eighty seven taxa were recorded for the first time in Iran. Thirty two of the genera belong to the Pennales and 5 to the Centrales. Species richness was rather high ranging from 66 to 95 taxa at the six sites studied. The epilithic diatom species found in Ramsar were dominated by cosmopolitan taxa found in meso- to fairly eutrophicwaters with high conductivity and high nutrient concentrations. The abundances found at all six sites were compiled in order to estimate the overall abundance of each taxon in Ramsar. This study includes EM pictures of diatoms observed in Ramsar, Iran.


2019 ◽  
Vol 53 (2) ◽  
pp. 255-278
Author(s):  
D. A. Chudaev

As a result of study of 18 samples, collected in Lake Teletskoye and inflowing rivers in 1992–1995, 34 diatom species of the genus Navicula Bory were found. Among them 21 taxa are new for the studied region, 7 species (Navicula arkona, N. hangaica, N. cf. pseudoreinhardtii, N. ricardae, N. scaniae, N. schweigeri, N. suecicarum) are recorded for the first time in Russia. One new species (N. pseudoharmoniae sp. nov.) is described. It is compared with N. harmoniae and N. digitoconvergens.


2016 ◽  
Vol 3 (1) ◽  
pp. 53
Author(s):  
Giovanni Pasini ◽  
Alessandro Garassino

<em>Ethusa</em> sp. (Decapoda, Brachyura, Ethusidae) from Valduggia (Vercelli, Piedmont, NW Italy) is here reported for the first time from the Pliocene of Italy. This new finding enlarges our knowledge on the distribution and stratigraphic range of this genus in the paleo- Mediterranean basin.


Author(s):  
P. Tongiorgi ◽  
E. Fregni ◽  
M. Balsamo

During 1996–1997 a systematic sampling programme was carried out in brackish coastal lakes and lagoons and in the delta of the River Po. In six of the nine collecting locations, 12 species of Gastrotricha were identified. One species, Chaetonotus ichthydioides, is new to science; another three species, the chaetonotidans Heterolepidoderma foliatum and the macrodasyidans Dendrodasys ponticus and Turbanella cf. pontica, and one macrodasyidan genus, Paradasys (P. subterraneus), were found in Italy for the first time. The unusual morphology of some of the species identified shows that Gastrotricha colonized brackish waters from both marine and freshwater habitats.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2301 ◽  
Author(s):  
Federica De Castro ◽  
Michele Benedetti ◽  
Giovanna Antonaci ◽  
Laura Del Coco ◽  
Sandra De Pascali ◽  
...  

The novel [Pt(O,O′-acac)(γ-acac)(DMS)], Ptac2S, Pt(II) complex has recently gained increasing attention as a potential anticancer agent for its pharmacological activity shown in different tumor cell lines, studied both in vitro and in vivo. The mechanism of action of Ptac2S, operating on non-genomic targets, is known to be very different from that of cis-[PtCl2(NH3)2], cisplatin, targeting nucleic acids. In this work, we evaluated the cytotoxicity of Ptac2S on the cisplatin resistant Epithelial Ovarian Carcinoma (EOC), SKOV-3 cells, by the MTT assay. A 1H-NMR metabolomic approach coupled with multivariate statistical analysis was used for the first time for Ptac2S to figure out the biological mechanisms of action of the complex. The metabolic variations of intracellular metabolites and the composition of the corresponding extracellular culture media were compared to those of cisplatin (cells were treated at the IC50 doses of both drugs). The reported comparative metabolomic analysis revealed a very different metabolic profile between Ptac2S and cisplatin treated samples, thus confirming the different mechanism of action of Ptac2S also in the Epithelial Ovarian Carcinoma (EOC), SKOV-3 cells line. In particular, higher levels of pyruvate were observed in Ptac2S treated, with respect to cisplatin treated, cells (in both aqueous and culture media). In addition, a very different lipid expression resulted after the exposure to the two drugs (Ptac2S and cisplatin). These results suggest a possible explanation for the Ptac2S ability to circumvent cisplatin resistance in SKOV-3 cells.


Engineering ◽  
2018 ◽  
Vol 4 (5) ◽  
pp. 635-642 ◽  
Author(s):  
Massimiliano Lega ◽  
Marco Casazza ◽  
Laura Turconi ◽  
Fabio Luino ◽  
Domenico Tropeano ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 698
Author(s):  
Vanessa Novoa ◽  
Octavio Rojas ◽  
Ramón Ahumada-Rudolph ◽  
Katia Sáez ◽  
Pablo Fierro ◽  
...  

Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with different degrees of urbanization, Rocuant-Andalién (highly urbanized) and Tubul-Raqui (with little urbanization), were analyzed using temperature, salinity, dissolved oxygen, pH, turbidity, granulometry, fecal coliform, and macroinvertebrate assemblage variables in summer and winter. In both wetlands marked seasonality in salinity, temperature and sediment texture classification, regulated by oceanic influence and changes in the freshwater budget, was observed. In the Rocuant-Andalién wetland, the increases in pH, dissolved oxygen, gravel percentage, and coliform concentration were statistically significant. Urbanization generated negative impacts on macroinvertebrate assemblage structure that inhabit the wetlands; greater richness and abundance (8.5 times greater) were recorded in the Tubul-Raqui wetland than in the more urbanized wetland. The multivariate statistical analysis reflects the alteration of these complex systems.


Phytotaxa ◽  
2019 ◽  
Vol 402 (4) ◽  
pp. 165 ◽  
Author(s):  
ANGELA MARIA DA SILVA-LEHMKUHL ◽  
THELMA ALVIM VEIGA LUDWIG ◽  
PRISCILA IZABEL TREMARIN ◽  
DENISE DE CAMPOS BICUDO

In the present study, we analyzed the taxonomy and ecology of fourteen species of Luticola registered in oligo- to hypereutrophic reservoirs of southeastern Brazil. Two new species were described using light and scanning electron microscopy. Luticola bartolomeii sp. nov. and Luticola iporangensis sp. nov. are distinguished from morphologically similar species by a combination of valve outline and dimensions. In addition, L. bartolomeii showed occluded isolated areolae that have a different shape and location, hitherto not observed in other Luticola species. We also compared the morphology of the new species with similar taxa and provided information on their ecological preferences. Luticola panamaensis is first recorded in Brazil, and another eight species are recorded for the first time for the state of São Paulo. This study expanded the distribution of species and added new information to the ecology of Luticola, as well as provided the first SEM images for some already known species. Information on the co-occurrence of other diatom species in the samples is also included.


2006 ◽  
Vol 84 (1) ◽  
pp. 151-163 ◽  
Author(s):  
M. Anne Harris ◽  
Brian F. Cumming ◽  
John P. Smol

New Brunswick lakes are subjected to multiple environmental stressors, such as atmospheric acid deposition and climate change. In the absence of long-term environmental data, the impacts of these stressors are not well understood. Long-term effects of environmental change on diatom species assemblages were assessed in the sediments of 16 New Brunswick lakes using paleolimnological approaches. A regional trend of increasing Cyclotella stelligera Cleve & Gunrow and decreasing Aulacoseira species complex was recorded in most lakes. Detailed paleolimnological analyses of Wolfe, Cundy, and West Long lakes revealed varying degrees of species change, with assemblage shifts beginning ca. 1900 CE (common era). These species trends are not consistent with acidification. However, linear regression of mean July temperature with time for two New Brunswick historical instrumental temperature records revealed statistically significant warming over the past century. The shift from heavily silicified tychoplanktonic Aulacoseira species to small planktonic diatom species, such as C. stelligera, is consistent with paleolimnological inferences of warming trends recorded in several other lake regions of the Northern Hemisphere. These assemblage shifts are likely due to recent climate change and may be mediated by reduced ice cover and (or) increased thermal stability (decreased lake mixing) during the open water period.


Author(s):  
Danijela Vidakovic ◽  
Jelena Krizmanić ◽  
Sanja Šovran

AbstractThe main objective of this paper is to report two benthic, epilithic diatom species from the Raška River. Samples were collected in April, June, August and November 2011 and March and May 2012 from 5 localities along the Raška River by scraping off the stone surface using a brush. Diatom frustules were first cleaned using the cold acid method, and then mounted on permanent slides. Descriptions (main valve measurements of the populations in the Raška River), ecology, distribution in Serbia and Europe, and appropriate photomicrographs of two species are presented. Navicula jakovljevicii Hustedt and Navicula catalanogermanica Lange-Bertalot & Hofmann are rarely found in Europe and these are new distributional records. These new taxa significantly contribute to diatom floristic diversity of the Raška River.


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