Effects of polyphenols on plankton assemblages and bacterial abundance representative of a pampean shallow lake: an experimental study

2020 ◽  
Vol 85 ◽  
pp. 85-100
Author(s):  
MF Alvarez ◽  
HH Benítez ◽  
LC Solari ◽  
JC Villegas Cortés ◽  
NA Gabellone ◽  
...  
Keyword(s):  
Shallow Lakes ◽  
Species Interactions ◽  
Response Times ◽  
Complex Environments ◽  
Pampean Region ◽  
Pampean Plain ◽  
Tannin Concentration ◽  
Surrounding Areas ◽  
Salado River

Shallow lakes are complex environments that play an important role in ecology. Their relationships with the surrounding areas make these lentic water bodies susceptible to alterations in response to human activity. For example, the input of polyphenols could be critical in altering species interactions. The shallow lakes located in the pampean plain of Argentina are major reservoirs of diversity, with the environmental habitats of the Salado River basin in particular having become impacted by human activities. The aim of this work was to evaluate the effects of different polyphenol concentrations (i.e. tannins) on changes in the plankton assemblages and on the abundance of bacteria in San Miguel del Monte Lake. Factorial experiments under laboratory conditions (4 tannin concentration levels and 4 response times) revealed that high tannin concentrations affected neither the phyto- and zooplankton assemblages nor bacterial abundances. Major changes both in assemblages and in the bacterioplankton abundances were dependent on exposure time. We found that the initial food web of grazers shifted to detritivorous feeding, thus producing a simplification of the community toward early succession. Although no effects of polyphenols were registered here, what proved striking was the resilience of the system and the capability to support high tannin concentrations throughout the experiment. Therefore, future investigations are necessary to elucidate the key role of such humic substances in the structuring of plankton assemblages of shallow lakes from strongly impacted areas, such as those found in the pampean region.

Rotifer dynamics in three shallow lakes from the Salado river watershed (Argentina): the potential modulating role of incident solar radiation

2015 ◽  
Vol 14 (11) ◽  
pp. 2007-2013 ◽  
Author(s):  
Nadia Diovisalvi ◽  
Armando M. Rennella ◽  
Horacio E. Zagarese
Keyword(s):  
Solar Radiation ◽  
Shallow Lakes ◽  
Seasonal Cycle ◽  
Schematic Representation ◽  
Incident Solar Radiation ◽  
River Watershed ◽  
Clear Sky ◽  
Rotifer Species ◽  
Salado River

A schematic representation of the seasonal cycle of rotifer in L. Chascomús. In this figure the relative abundances of the three dominant rotifer species are expressed as fractions of the estimated clear-sky mean daily incident solar radiation.

scholarly journals Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors

Biosensors ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Agnes Purwidyantri ◽  
Telma Domingues ◽  
Jérôme Borme ◽  
Joana Rafaela Guerreiro ◽  
Andrey Ipatov ◽  
...  
Keyword(s):  
Phosphate Buffer ◽  
Species Interactions ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Limit Of Detection ◽  
Debye Length ◽  
Intermolecular Forces ◽  
Single Layer Graphene ◽  
Dna Adsorption

Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity.

Connectivity of temperate shallow lakes to groundwater in the Pampean Plain, Argentina: A remote sensing and multi-tracer approach

2021 ◽  
Vol 13 ◽  
pp. 100556
Author(s):  
María Ximena Solana ◽  
Orlando Mauricio Quiroz Londoño ◽  
Asunción Romanelli ◽  
Flavia Donna ◽  
Daniel Emilio Martínez ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Shallow Lakes ◽  
Pampean Plain

A Direct Assessment of the Role of Expectation in Inhibition of Return

2007 ◽  
Vol 18 (9) ◽  
pp. 783-787 ◽  
Author(s):  
Thomas M. Spalek
Keyword(s):  
Inhibition Of Return ◽  
Response Times ◽  
Direct Measure ◽  
Imaginary Circle ◽  
Direct Assessment ◽  
Relevant Evidence ◽  
Indirect Measures

An object hidden among distractors can be found more efficiently if previously searched locations are not reinspected. The inhibition-of-return (IOR) phenomenon indexes the tendency to avoid reinspections. Two accounts of IOR, that it is due to inhibition and that it is due to expectation, are generally regarded as incompatible. The relevant evidence to date, however, has been indirect: Inhibition or expectation has been inferred from response times or similar indirect measures. This article reports the first direct measure of IOR, obtained by asking observers to predict the location of the next target in a display containing eight possible locations on an imaginary circle. On any given trial, the previously cued location was chosen less frequently (impairment)—and the opposite location was chosen more frequently (facilitation)—than chance (choice of all other locations was at chance). The impairment is consistent with both inhibition and expectation accounts; the facilitation is consistent only with expectation accounts. This work also shows that inhibition and expectation are not necessarily incompatible: Implementing expectations may entail inhibiting previously cued locations.

Lateralization of lexical processing in monolinguals and bilinguals

2021 ◽  
pp. 136700692110188
Author(s):  
Filiz Mergen ◽  
Gulmira Kuruoglu
Keyword(s):  
Lexical Processing ◽  
Response Times ◽  
Visual Fields ◽  
Decision Task ◽  
Bilingual Speakers ◽  
Visual Hemifield ◽  
Significant Difference ◽  
Brain Correlates ◽  
Orthographic Neighbors

Aims and objectives: This study aims to investigate how lexical processing (LP) is organized in early Turkish–English bilinguals and Turkish monolinguals. Methodology: We used a visual hemifield paradigm where bilingual ( n = 48) and monolingual ( n = 53) participants performed a lexical decision task. Bilingual participants performed the task in both their languages. Data and analysis: We recorded response times (RTs) and the accuracy rates (ARs) of the participants. An analysis of variance and t-test were run to analyze the bilingual and monolingual data, respectively. Findings: The results obtained from the analysis of the RTs and ARs for the Turkish and English words showed a balanced hemispheric organization in LP in bilingual speakers. The RTs for Turkish words in the monolingual group provided supportive evidence for the predominant role of the left hemisphere in LP. However, no significant difference was found in the accuracy of their answers, suggesting that the monolingual participants’ performance was not influenced by visual field of presentation of the words. Finally, the comparison of the two groups revealed that bilingual participants’ performance was inferior to monolinguals’ in speed and accuracy of processing of words presented in both visual fields. This result gives further support for the differential representation of LP in monolinguals and bilinguals. Originality: The psycholinguistic literature abounds with studies of LP in bilinguals and monolinguals from a variety of language backgrounds; however, there is much less data regarding the brain correlates of LP in Turkish–English bilinguals and Turkish monolinguals. Implications: Since Turkish–English bilinguals and Turkish monolinguals are underrepresented in the literature as compared to the population who speak other languages with alphabetic writing, this study provides preliminary data for future studies. Limitations: We did not control for gender or lexical factors such as orthographic neighbors when designing the word sets used as stimuli.

scholarly journals Comparison of different extraction kits to isolate microRNA fromGalleria mellonella(wax moth) larvae infected withMetarhizium brunneum(ARSEF4556)

2019 ◽  
Author(s):  
Muneefah A. Alenezi ◽  
Tariq M. Butt ◽  
Daniel C. Eastwood
Keyword(s):  
Fungal Pathogens ◽  
High Throughput Sequencing ◽  
Galleria Mellonella ◽  
Host Tissue ◽  
Tissue Cultures ◽  
Complex Environments ◽  
Infected Insect ◽  
Sequencing And Expression ◽  
Wax Moth

ABSTRACTMicroRNAs (miRNAs) play an important role in regulating gene expression and are involved in developmental processes in animals, plants and fungi. To understand the role of miRNAs in a biological system, it is important to optimise the extraction procedures to obtain high quality and quantity nucleic acid that enable high throughput sequencing and expression analysis. Numerous kit-based miRNA extraction protocols have been optimised generally to single cell or tissue cultures. Fungi, however, often occupy physically and chemically complex environments which miRNA make extraction challenging, such as fungal pathogens interacting within plant or animal host tissue. We used aGalleria mellonella(wax moth) larvae and entomopathogenic fungusMetarhizium brunneum ARSEF 4556host/pathogen model to compare commercially available miRNA extraction kits (Invitrogen PureLink™ miRNA Isolation Kit, Ambion mirVana™miRNA Isolation Kit and Norgen microRNA purification Kit). Our results showed reproducible and significant differences in miRNAs extraction between the kits, with the Invitrogen PureLink™ miRNA Isolation protocol demonstrating the best performance in terms of miRNA quantity, quality and integrity isolated from fungus-infected insect tissue.

THE ROLE OF CONDENSED TANNINS IN THE DIGESTION OF FRESH Lotus pedunculatus BY SHEEP

1984 ◽  
Vol 64 (5) ◽  
pp. 181-182 ◽  
Author(s):  
T. N. BARRY
Keyword(s):  
Growth Hormone ◽  
Condensed Tannins ◽  
Condensed Tannin ◽  
Soluble Carbohydrate ◽  
Hormone Concentration ◽  
Plasma Growth Hormone ◽  
Tannin Concentration ◽  
Lotus Pedunculatus ◽  
Ruminal Digestion

Relative to non-tannin-containing fresh forages, condensed tannins in Lotus pedunculatus increased duodenal N flow and calculated absorption of amino acids from the small intestine, but depressed ruminal digestion of soluble carbohydrate and hemicellulose. Plasma growth hormone concentration was positively and linearly related to forage condensed tannin concentration. Key words: Condensed tannin, nitrogen digestion, growth hormone

The Quequén Salado river basin: Geology and biochronostratigraphy of the Mio-Pliocene boundary in the southern Pampean plain, Argentina

2017 ◽  
Vol 76 ◽  
pp. 362-374 ◽  
Author(s):  
E. Beilinson ◽  
G.M. Gasparini ◽  
R.L. Tomassini ◽  
M.A. Zárate ◽  
C.M. Deschamps ◽  
...  
Keyword(s):  
River Basin ◽  
Pampean Plain ◽  
Salado River
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