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1. A Latin American network of microbial observatories for monitoring aquatic ecosystems

Author

Paulina Fermani, Nicolás Martyniuk, Martín Saraceno, Marina Gerea, Carmen Sabio y García, María R. Schiaffino, María L. Sánchez, Sharon Allen Dohle, Cecilia Alonso, Maité A. Barrena, Marcela Bastidas Navarro, María C. Bernal, Giuliana M. Burgueño Sandoval, Nicolás ´Cetra, Michaela L. De Melo, Patricia E. García, Bárbara M. Gómez, Sebastián Gómez Lugo, Eddy Gómez-Ramírez, Luciana Griffero, Leandro A. Hünicken, Leonardo Lagomarsino, Mariana Lozada, Carolina Mansilla Ferro, Beatriz Modenutti, Erick Mateus-Barros, Damián A. Ojeda, María L. Padulles, Emiliano Pereira, Sol Porcel, María V. Quiroga, Juan F. Saad, María C. Salas, Janet Santucho, Hugo Sarmento, María E. Segade, Carolina Soto Cárdenas, Ana Torremorell, Fernando Unrein, María S. Zabala, Juan Zanetti, and Martín Graziano

Subjects
aquatic ecosystems, biomonitoring, microorganisms, research consortium, Environmental sciences, GE1-350, Ecology, QH540-549.5
Abstract

Freshwater environments and coastal marine areas provide key ecosystem services to society and serve as habitats for biodiversity. However, they face major challenges from human activities and climate factors, leading to global degradation. The effect of these agents depends on geographic location and climate, among other factors. To comprehensively understand the effect of these factors, continuous, standardized and long-term information is crucial. In particular, the aquatic microbiome plays a fundamental role in the cycling of matter and has been shown to act as a robust indicator of ecological status. Long-term monitoring of microbial assemblages can provide valuable insights into the characteristics and the changes water bodies undergo, delivering early warnings of critical impacts. Thus, the Latin American Aquatic Microbial Observatory Network (AMOLat) was set up during the inaugural meeting of the Latin American Collaborative Network on Microbial Aquatic Ecology (μSudAqua) in 2017. Observatory sites were carefully chosen, considering their accessibility and local relevance to each research group, ensuring the ongoing consistency of sampling efforts. This work aims to provide a historical overview of the network’s formation, highlighting key debates and definitions that took place during 2017-2023. Furthermore, it includes an initial characterization of the observatory sites and explores the possibilities that they offer to understand the structure and function of aquatic ecosystems in Latin America. The network presently encompasses 13 observatories, spanning a broad latitudinal range, numerous ecoregions and diverse aquatic ecosystems, displaying different environmental and anthropic impacts. Participating groups enhanced interactions, created a Protocol Book and showcased initial results through various communication efforts. Ultimately, establishing a regional network of aquatic observatories becomes mandatory for providing essential reference points to assess the response of microorganisms to global change in both the short and long term within Latin America.

Published
2024
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2. Top-down modulation impairs priming susceptibility in complex decision-making with social implications

Author

Franco Agustín Bernal, Tomás Alves Salgueiro, Axel Brzostowski, Emilio Recart Zapata, Ayelén Carames, Juan Manuel Pérez, Damián Furman, Martín Graziano, and Pablo Nicolás Fernández Larrosa

Subjects
Medicine, Science
Abstract

Abstract Could social context variables prime complex decisions? Could top-down processes impair this priming susceptibility? Complex decisions have been mainly studied from economic and moral perspectives, and Dual Process Theories provide evidence of how these processes could be affected. To address these issues from a political perspective, online experiments were conducted. Participants (n = 252) were asked to choose a face from 4 options, each associated with different frequencies (repetition priming) or with phrases with different emotional valence (emotional priming), for an unspecified task (UST group) or an important task (IMT group). The most repeated face was chosen most in the UST group, and was associated with lower response times. Positive faces were equally chosen by both groups. To compare results in a more ecological situation, a social study was conducted during the 2019 Argentine Presidential Election, including online surveys (n = 3673) and analysis of news media mentioning candidates. The familiarity and trust to each candidate explained the voting-probability for most of them, as well as correlated with their frequency of mentions in the news, their positive associations, and election results. Our results suggest complex decision-making is susceptible to priming, depending on top-down modulation.

Published
2022
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3. Unraveling the ecological processes modulating the population structure of Escherichia coli in a highly polluted urban stream network

Author

Martín Saraceno, Sebastián Gómez Lugo, Nicolás Ortiz, Bárbara M. Gómez, Carmen A. Sabio y García, Nicolás Frankel, and Martín Graziano

Subjects
Medicine, Science
Abstract

Abstract Escherichia coli dynamics in urban watersheds are affected by a complex balance among external inputs, niche modulation and genetic variability. To explore the ecological processes influencing E. coli spatial patterns, we analyzed its abundance and phylogenetic structure in water samples from a stream network with heterogeneous urban infrastructure and environmental conditions. Our results showed that environmental and infrastructure variables, such as macrophyte coverage, DIN and sewerage density, mostly explained E. coli abundance. Moreover, main generalist phylogroups A and B1 were found in high proportion, which, together with an observed negative relationship between E. coli abundance and phylogroup diversity, suggests that their dominance might be due to competitive exclusion. Lower frequency phylogroups were associated with sites of higher ecological disturbance, mainly involving simplified habitats, higher drainage infrastructure and septic tank density. In addition to the strong negative relationship between phylogroup diversity and dominance, the occurrence of these phylogroups would be associated with increased facilitated dispersal. Nutrients also contributed to explaining phylogroup distribution. Our study proposes the differential contribution of distinct ecological processes to the patterns of E. coli in an urban watershed, which is useful for the monitoring and management of fecal pollution.

Published
2021
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4. Unraveling the ecological processes modulating the population structure of Escherichia coli in a highly polluted urban stream network

Author

Sebastián Gómez Lugo, Martin Saraceno, Martín Graziano, Nicolás Frankel, Nicolás Ortiz, Bárbara M. Gómez, and Carmen A. Sabio y García

Subjects
Urban stream, Science, Niche, Wastewater, Biology, Generalist and specialist species, Article, Microbial ecology, 03 medical and health sciences, Rivers, Abundance (ecology), Limnology, Escherichia coli, Dominance (ecology), Cities, Ecosystem, Phylogeny, 030304 developmental biology, 0303 health sciences, Multidisciplinary, 030306 microbiology, Ecology, Microbiota, Macrophyte, Urban ecology, Spatial ecology, Biological dispersal, Medicine, San Francisco, Environmental Pollution, Estuaries, Water Microbiology, Environmental Monitoring
Abstract

Escherichia coli dynamics in urban watersheds are affected by a complex balance among external inputs, niche modulation and genetic variability. To explore the ecological processes influencing E. coli spatial patterns, we analyzed its abundance and phylogenetic structure in water samples from a stream network with heterogeneous urban infrastructure and environmental conditions. Our results showed that environmental and infrastructure variables, such as macrophyte coverage, DIN and sewerage cover, mostly explained E. coli abundance, with a negative relationship between abundance and phylogroup richness. Moreover, main generalist phylogroups A and B1 were found in high proportion, which, together with an observed negative relationship between E. coli abundance and phylogroup richness suggests that their dominance is due to competitive exclusion. Low-frequency taxa were associated with sites of higher ecological disturbance, mainly involving simplified habitats, higher drainage infrastructure and septic tank density. In addition to the strong positive relationship between phylogroup richness and evenness, the occurrence of these phylogroups would be associated with increased facilitated dispersal. Nutrients also contributed to explaining phylogroup distribution. Our study highlights the differential contribution of distinct ecological processes to the patterns of E. coli in an urban watershed, which is useful for the monitoring and management of fecal pollution.

Published
2020
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5. Differential impact of Limnoperna fortunei-herbicide interaction between Roundup Max® and glyphosate on freshwater microscopic communities

Author

Daniel Cataldo, Alicia Vinocur, Florencia Gattás, Martín Graziano, Haydée Pizarro, and M. dos Santos Afonso

Subjects
0106 biological sciences, MULTIPLE STRESSORS, Nitrogen, Health, Toxicology and Mutagenesis, Otras Ciencias Biológicas, Glycine, MICROSCOPIC COMMUNITIES, Fresh Water, GLYPHOSATE, LIMNOPERNA FORTUNEI, 010501 environmental sciences, Environment, 01 natural sciences, Invasive species, Ciencias Biológicas, chemistry.chemical_compound, GRAZING RATE, Water Quality, ROUNDUP MAX&reg, Environmental Chemistry, Animals, Limnoperna fortunei, OUTDOOR MESOCOSMS, 0105 earth and related environmental sciences, Differential impact, biology, Ecology, Herbicides, 010604 marine biology & hydrobiology, Water, Phosphorus, General Medicine, biology.organism_classification, Pollution, INVASIVE SPECIES, Bivalvia, chemistry, Glyphosate, Phytoplankton, Mytilidae, Water Pollutants, Chemical, CIENCIAS NATURALES Y EXACTAS
Abstract

Multiple anthropogenic stressors act simultaneously on the environment, with consequences different from those caused by single-stressor exposure. We investigated how the combination of the invasive mussel Limnoperna fortunei and a widely applied herbicide, Roundup Max®, affected freshwater microscopic communities and water quality. Further, we compared these results with those induced by the combination of the mussel and technical-grade glyphosate. We carried out a 34-day experiment in outdoor mesocosms, applying the following six treatments: 6 mg L−1 of technical-grade glyphosate (G), the equivalent concentration of glyphosate in Roundup Max® (R), 100 mussels (M), the combination of mussels and herbicide either in the technical-grade or formulated form (MG and MR, respectively), and control (C). Herbicides significantly increased total phosphorus in water; R and MR showed greater initial total nitrogen and ammonium. R increased picoplankton abundance and caused an eightfold increase in phytoplankton, with high turbidity values; G had a lower effect on these variables. Herbicide-mussel combination induced an accelerated dissipation of glyphosate in water (MG 6.36 ± 0.83 mg G g DW−1 day−1 and MR 5.16 ± 1.26 mg G g DW−1 day−1). A synergistic effect on ammonium was observed in MR but not in MG. MR and MG had an antagonistic effect on phytoplankton, which showed a drastic reduction due to grazing, as revealed by M. We provide evidence of differential effects of Roundup Max® and technical-grade glyphosate over water quality and microscopic communities, and in combination with mussels. However, in the combination of mussels and herbicides, mussels seem to play a leading role. In the presence of L. fortunei, the effects of higher nutrient availability provided by herbicides addition were counteracted by the filtration activity of mussels, which released nutrients, grazed on picoplankton and phytoplankton, and boosted the development of other primary producers, periphyton and metaphyton. Fil: Gattás, Florencia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Vinocur, Alicia Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Graziano, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Pizarro, Haydee Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Cataldo, Daniel Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina

Published
2016
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6. Distinct patterns of functional brain connectivity correlate with objective performance and subjective beliefs

Author

Bruno Wicker, Phil McAleer, Mariano Sigman, Yann Corentin Cojan, Pablo Barttfeld, Martín Graziano, Pascal Belin, Ramón Leiguarda, Department of Psychiatry, University of California [Los Angeles] (UCLA), University of California-University of California, and ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011)

Subjects
CIENCIAS MÉDICAS Y DE LA SALUD, Partial-Report-Paradigm, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Neurociencias, Metacognition, 050105 experimental psychology, Interoception, 03 medical and health sciences, Functional brain, 0302 clinical medicine, Task Performance and Analysis, Humans, 0501 psychology and cognitive sciences, Set (psychology), Multidisciplinary, Resting state fMRI, 05 social sciences, Brain, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences, purl.org/becyt/ford/3.1 [https], Biological Sciences, Network connectivity, Magnetic Resonance Imaging, Medicina Básica, Perceptual decision, purl.org/becyt/ford/3 [https], Psychology, Social psychology, 030217 neurology & neurosurgery, Resting-State, Cognitive psychology
Abstract

The degree of correspondence between objective performance and subjective beliefs varies widely across individuals. Here we demonstrate that functional brain network connectivity measured before exposure to a perceptual decision task covaries with individual objective (type-I performance) and subjective (type-II performance) accuracy. Increases in connectivity with type-II performance were observed in networks measured while participants directed attention inward (focus on respiration), but not in networks measured during states of neutral (resting state) or exogenous attention. Measures of type-I performance were less sensitive to the subjects’ specific attentional states from which the networks were derived. These results suggest the existence of functional brain networks indexing objective performance and accuracy of subjective beliefs distinctively expressed in a set of stable mental states. Fil: Barttfeld, Pablo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Institut National de la Santé et de la Recherche Médicale. Cognitive Neuroimaging Unit; Francia; Fil: Wicker, Bruno. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Centre National de la Recherche Scientifique. Unité Mixte de Recherche. Institut de Neurosciences de la Timone; Francia; Fil: McAleer, Phil. Glasgow University. Department of Psychology; Reino Unido; Fil: Belin, Pascal. Glasgow University. Department of Psychology; Reino Unido; Fil: Cojan, Yann Corentin. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Fil: Graziano, Martín. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Fil: Leiguarda, Ramón Carlos. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina; Fil: Sigman, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina; Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina; Universidad Torcuato Di Tella; Argentina

Published
2013
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7. The dynamics of sensory buffers: Geometric, spatial, and experience-dependent shaping of iconic memory

Author

Martín Graziano and Mariano Sigman

Subjects
Adult, Male, READING, Echoic memory, Time Factors, Speech recognition, Otras Ciencias Biológicas, Models, Neurological, purl.org/becyt/ford/1 [https], Ciencias Biológicas, Young Adult, Perceptual learning, OBJECT RECOGNITION, SEARCH, Humans, Attention, Visual short-term memory, purl.org/becyt/ford/1.6 [https], Cued speech, Communication, PERCEPTUAL LEARNING, Recall, business.industry, Working memory, MEMORY, Memory rehearsal, ATTENTION, Iconic memory, Awareness, Sensory Systems, Ophthalmology, Memory, Short-Term, Pattern Recognition, Visual, Space Perception, Female, business, Psychology, Photic Stimulation, CIENCIAS NATURALES Y EXACTAS
Abstract

When a stimulus is presented, its sensory trace decays rapidly, lasting for approximately 1000 ms. This brief and labile memory, referred as iconic memory, serves as a buffer before information is transferred to working memory and executive control. Here we explored the effect of different factors - geometric, spatial, and experience - with respect to the access and the maintenance of information in iconic memory and the progressive distortion of this memory. We studied performance in a partial report paradigm, a design wherein recall of only part of a stimulus array is required. Subjects had to report the identity of a letter in a location that was cued in a variable delay after the stimulus onset. Performance decayed exponentially with time, and we studied the different parameters (time constant, zero-delay value, and decay amplitude) as a function of the different factors. We observed that experience (determined by letter frequency) affected the access to iconic memory but not the temporal decay constant. On the contrary, spatial position affected the temporal course of delay. The entropy of the error distribution increased with time reflecting a progressive morphological distortion of the iconic buffer. We discuss our results on the context of a model of information access to executive control and how it is affected by learning and attention. © ARVO. Fil: Graziano, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Sigman, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina

Published
2008

8. Fostering urban transformations in Latin America: lessons around the ecological management of an urban stream in coproduction with a social movement (Buenos Aires, Argentina)

Author

Martin Graziano, Grecia Stefanía. de Groot, Laura Daniela. Pilato, María Laura. Sánchez, Irina Izaguirre, and Haydée N. Pizarro

Subjects
environmental governance, social movements, stream rehabilitation, urban social-ecological traps, water governance, Biology (General), QH301-705.5, Ecology, QH540-549.5
Abstract

Collaborative community-based approaches are proposed as a way to overcome the difficulties exerted by a broad range of social-ecological traps that emerge at the reconfiguration of social-ecological systems onto sustainable paths. Despite this, a deep examination of the social-ecological processes and interactions that constrain these approaches in different urban contexts is still necessary to improve their success. Latin American countries have institutional, political, and social characteristics that could constrain the pathways to sustainability in different ways from countries of the Global North, particularly in their metropolitan areas. Here, we present an experience (2015-2018) held in cooperation with workers of a social cooperative framed in an urban social movement from Argentina, related to the ecological rehabilitation of a highly degraded urban stream through the management of the riparian vegetation and the reintroduction of native macrophytes. The methodology involved a codesign approach based on a set of participatory action-research tools, together with resilience system analysis through causal loop diagrams, and three different interventions of a 200-m reach at the upstream area of the San Francisco stream (Buenos Aires, Argentina). The participatory diagnostic showed a strong negative effect of the current management guidelines on the riparian and aquatic vegetation, reflecting a positive feedback loop that reinforces this negative state, and revealed a hierarchical governance regime associated with the management of the watershed. Furthermore, it detected a strong motivation of local workers to generate transformative actions in terms of the sanitary and social-ecological improvements of the local habitat. The management actions showed a relatively high short-term survival of the macrophyte transplants (30-60% in a period of 2-4 months), displaying a strong spatial structure of the survival units, and downscaling to about 10% in the long term (6-12 months after interventions). A combination of biophysical and social processes related both to institutional and rigidity traps affected the survival of the transplants, reflecting the inertia of the current management programs to ecological improvements of the stream. In summary, the present work highlights the social-ecological constraints arising from transformative collective actions toward the ecological management of a stream at a highly vulnerable and bureaucratic urban context, with implications for social-ecological urban transformations in Latin America and the design of effective participatory governance actions in alliance with local social movements.

Published
2019
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9. The spatial and temporal construction of confidence in the visual scene.

Author

Martin Graziano and Mariano Sigman

Subjects
Medicine, Science
Abstract

Human subjects can report many items of a cluttered field a few hundred milliseconds after stimulus presentation. This memory decays rapidly and after a second only 3 or 4 items can be stored in working memory. Here we compared the dynamics of objective performance with a measure of subjective report and we observed that 1) Objective performance beyond explicit subjective reports (blindsight) was significantly more pronounced within a short temporal interval and within specific locations of the visual field which were robust across sessions 2) High confidence errors (false beliefs) were largely confined to a small spatial window neighboring the cue. The size of this window did not change in time 3) Subjective confidence showed a moderate but consistent decrease with time, independent of all other experimental factors. Our study allowed us to asses quantitatively the temporal and spatial access to an objective response and to subjective reports.

Published
2009
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