Marismas patagónicas: las últimas de Sudamérica

Las marismas son ecosistemas regularmente inundados por el mar. Esta característica condiciona su flora y su fauna, que deben vivir en un medio sucesivamente cubierto y descubierto por el agua y caracterizado por su alta salinidad. La costa atlántica de la Patagonia (Argentina) alberga abundantes y variadas marismas, hasta el momento poco conocidas y aún menos estudiadas. El autor contesta la pregunta si pueden vivir plantas y animales terrestres en lugares regularmente cubiertos y descubiertos por las mareas, y pasar así la mitad de sus vidas sumergidos en agua de mar. Contesta sobre qué son las marismas y quiénes las habitan, en particular las de la Patagonia Argentina, la importancia del ambiente: su uso y valoración. Este artículo de divulgación incluye el mapa con marismas desde el sur de Brasil hasta la Patagonia austral sí como otras lecturas sugeridas

Invasiones biológicas y dimensiones humanas: Aún necesitamos trabajar duro en nuestras perspectivas sociales

In this article, we analyze and challenge a long-held paradigm that reduces the field of biological invasions to its ecological components. We explore thirteen case studies grouped within three major human dimensions (values, traditions, and quality of life) to show how biological invasions interwove and interact with them. The group of human dimensions we explore in this work, although small, exposes a rich spectrum of interdisciplinary synergies between natural and social sciences that should receive more attention to make the field of biological invasions more sound and socially integrated.Invasiones biológicas y dimensiones humanas: Aún necesitamos trabajar duro en nuestras perspectivas sociales. En este artículo analizamos y desafiamos el paradigma que reduce el campo de las invasiones biológicas a sus componentes ecológicos. Para esto, revisamos trece casos de estudio agrupados dentro de tres dimensiones humanas principales (valores, tradiciones y calidad de vida) para mostrar cómo las invasiones biológicas se entretejen e interactúan con ellas. El grupo de dimensiones humanas que exploramos en este trabajo, aunque pequeño, expone un rico espectro de sinergias interdisciplinarias entre las ciencias naturales y sociales que deberían recibir más atención para hacer que el campo de las invasiones biológicas sea más sólido y socialmente integrado.Fil: Bortolus, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Schwindt, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentin

The role of the physical structure of Spartina densiflora Brong. in structuring macroinvertebrate assemblages

In Patagonian rocky salt marshes, the presence of the austral cordgrass Spartina densiflora provide habitat for diverse faunal assemblages. Two different mechanisms may influence the distribution and abundance patterns of the associated organisms. Those generated by the biological properties of cordgrasses and those caused or mediated by the physical structure supplied by the plants. The aims of this study were: (1) to determine the effect of cordgrasses on macroinvertebrate assemblages dominating a rocky marsh; and (2) to determine how much of this effect is caused by the physical structure supply by the plants. In order to achieve these objectives we conducted two field manipulative experiments. In the first one we manipulated the presence of defaunated transplants of cordgrass, and in the second one, we did the same with plastic mimics cordgrasses simulating de architecture of Spartina densiflora. In both experiments, sessile and mobile assemblages were separately examined to evaluate whether they respond in the same way or not. Abundance and richness of mobile and sessile organisms were higher in transplant and mimic cordgrass plots compared to controls, indicating that the presence of cordgrasses, either transplanted or artificial, has a positive effect on sessile and mobile assemblages. Furthermore, we found that the composition of mobile and sessile macroinvertebrates assemblages did not differ between transplants and mimics. Therefore, the physical structure of cordgrass was found to be the major factor influencing macroinvertebrates assemblages in the studied Patagonia rocky salt marshes. Within the period of one year, mobile and sessile fauna colonized several times more abundantly transplant and artificial cordgrass than the control plots, highlighting the key role of cordgrasses in optimizing the colonization rate of macroinvertebrate communities in this rocky bottom environment. Since Spartina densiflora is invading different regions worldwide, our study may help to predict its potential effect on the invaded communities.Fil: Sueiro, Maria Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Bortolus, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Schwindt, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

The rational search for selective anticancer derivatives of the peptide Trichogin GA IV: a multi-technique biophysical approach

Peptaibols are peculiar peptides produced by fungi as weapons against other microorganisms. Previous studies showed that peptaibols are promising peptide-based drugs because they act against cell membranes rather than a specific target, thus lowering the possibility of the onset of multi-drug resistance, and they possess non-coded alpha-amino acid residues that confer proteolytic resistance. Trichogin GA IV (TG) is a short peptaibol displaying antimicrobial and cytotoxic activity. In the present work, we studied thirteen TG analogues, adopting a multidisciplinary approach. We showed that the cytotoxicity is tuneable by single amino-acids substitutions. Many analogues maintain the same level of non-selective cytotoxicity of TG and three analogues are completely non-toxic. Two promising lead compounds, characterized by the introduction of a positively charged unnatural amino-acid in the hydrophobic face of the helix, selectively kill T67 cancer cells without affecting healthy cells. To explain the determinants of the cytotoxicity, we investigated the structural parameters of the peptides, their cell-binding properties, cell localization, and dynamics in the membrane, as well as the cell membrane composition. We show that, while cytotoxicity is governed by the fine balance between the amphipathicity and hydrophobicity, the selectivity depends also on the expression of negatively charged phospholipids on the cell surface

Identifying conformational changes with site-directed spin labeling reveals that the GTPase domain of HydF is a molecular switch

[FeFe]-hydrogenases catalyse the reduction of protons to hydrogen at a complex 2Fe[4Fe4S] center called H-cluster. The assembly of this active site is a multistep process involving three proteins, HydE, HydF and HydG. According to the current models, HydF has the key double role of scaffold, upon which the final H-cluster precursor is assembled, and carrier to transfer it to the target hydrogenase. The X-ray structure of HydF indicates that the protein is a homodimer with both monomers carrying two functional domains: a C-terminal FeS cluster-binding domain, where the precursor is assembled, and a N-terminal GTPase domain, whose exact contribution to cluster biogenesis and hydrogenase activation is still elusive. We previously obtained several hints suggesting that the binding of GTP to HydF could be involved in the interactions of this scaffold protein with the other maturases and with the hydrogenase itself. In this work, by means of site directed spin labeling coupled to EPR/PELDOR spectroscopy, we explored the conformational changes induced in a recombinant HydF protein by GTP binding, and provide the first clue that the HydF GTPase domain could be involved in the H-cluster assembly working as a molecular switch similarly to other known small GTPases

Marismas patagónicas: Las últimas de Sudamérica

Varios siglos han pasado desde que los primeros exploradores y naturalistas europeos realizaron las descripciones iniciales de las especies y hábitats de la costa este de Sudamérica. Sin embargo, la existencia misma de marismas en la Patagonia austral permaneció virtualmente ignorada hasta hace muy poco. Durante los últimos años, mediante la realización de relevamientos por aire y tierra, así como por el análisis de fotografías históricas y de imágenes satelitales, se logró hallar, describir y clasificar esos ambientes, y comenzar a integrarlos al conocimiento ecológico. Estos estudios colocan a Sudamérica entre las regiones más ricas del mundo en cuanto a la variedad de sus marismas.Fil: Bortolus, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Invasive barnacle fouling on an endemic burrowing crab mobile basibionts as vectors to invade a suboptimal habitat

Neohelice (Chasmagnathus) granulata is an ecosystem engineer endemic of salt marshes and mudflats of the southwestern Atlantic coast, where several Patagonian salt marshes were invaded by the acorn barnacle Balanus glandula, a typical rocky shore species. In this work, we supply the first report of the occurrence of epibiosis of B. glandula on N. granulata in these salt marshes and we describe the major ecological features of this invader/native association in order to generate sound baseline for further investigations and management decisions. Our results show that barnacles are found in the entire dorsal and lateral surface of the crabs, and specially in vital zones such us the basal insertion of the chelipeds, walking appendages, ocular peduncles, jaws, mouth with the carapace. Furthermore, the size reached by barnacles suggest that they are sexually mature and can reproduce while fouling on the crabs, being the maximum size of barnacles tightly associated and determined by the duration of the crab's inter-molt span. Our results highlight the mechanisms by which an invasive rocky shore invader can exploit an unfavorable environment (i.e. mobile substratum) to persist on soft bottom systems.Neohelice (Chasmagnathus) granulata es un ingeniero de ecosistemas endémico de las marismas y planicies barrosas de la costa atlántica sud-occidental, donde varias marismas patagónicas han sido invadidas por el cirripedio Balanus glandula, una especie típica de intermareales rocosos. En este trabajo, se proporciona el primer reporte de la ocurrencia de epibiosis de B. glandula sobre N. granulata en estas marismas y se describen las principales características ecológicas de esta asociación invasor/nativo con el objetivo de generar información de línea de base adecuada para investigaciones futuras y la toma de desiciones de manejo. Nuestros resultados muestran que los cirripedios se encuentran en la superficie dorsal y lateral de los cangrejos y, en especial, en zonas vitales como la inserción basal de los quelípedos, los apéndices caminadores, los pedúnculos oculares, las mandíbulas y la boca, con el caparazón. Además, el tamaño medio de los cirripedios sugiere que alcanzan la madurez sexual y son capaces de reproducirse mientras se encuentran adheridos a los cangrejos. Por otra parte, el tamaño máximo de los cirripedios se encuentra fuertemente asociado y determinado por la duración del intervalo entre-mudas de los cangrejos. Así, nuestros resultados ponen de manifiesto los mecanismos por los cuales un invasor de intermareales rocosos es capaz de explotar un entorno desfavorable (es decir, sustratos móviles) para persistir en intermareales de fondos blandos.Fil: Mendez, María Martha. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Sueiro, Maria Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Schwindt, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Bortolus, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

I temi della riproduzione: quale counseling con le donne? In altri termini, possiamo rendere la scienza piu\u2019 amica, piu\u2019 vicina alle donne (e agli uomini)?

Si tratta di un progetto di ricerca qualitativa gender sensitive, condotto da ricercatrici donne, con altre donne come partecipanti, su temi legati al mondo femminile, come la salute riproduttiva. Nello stesso tempo rappresenta un luogo d\u2019incontro tra la Evidence Based Medicine e la Narrative Based Medicine, nonch\ue8 un\u2019occasione di riflessione sul sostegno alle buone pratiche per l\u2019area materno-infantile, e pi\uf9 in generale sulla gender equity nel campo della salute. La ricerca approfondisce i temi del counseling preconcezionale, promossi dallo \u201cStudio Acido Folico\u201d, allo scopo di migliorare la comprensione dei comportamenti, delle conoscenze e delle percezioni delle donne in questo ambito.This gender sensitive qualitative research represents a meeting place for the Evidence Based Medicine and the Narrative Based Medicine, and an opportunity to promote the good practices and the gender equity in health. According to \u201cThe Italian Folic Acid Study\u201d, a project that evaluates the efficacy of high dose of folic acid to prevent the occurrence of congenital malformations, and promotes a full standardized preconceptional counselling in the general population in childbearing age, this research increases information about behaviours, knowledge, perceptions of the women in this field

Cleaning by beaching: Introducing a new alternative for hull biofouling management in Argentina

Recreational vessels favor the secondary spread of exotic marine species hosted on hull biofouling communities through coastal trips. Hull biofouling is also a problem for vessel owners because it reduces the efficiency and maneuverability of the vessel. This study documents a pioneer case of alternative hull biofouling management in a context where local regulations prohibit in-water cleaning operations and where there are no shore-based facilities. We designed and put into practice a method to manually clean a 35 meter long catamaran, by beaching it in a macrotidal beach of Patagonia, Argentina. During the cleaning, all hull biofouling was removed and collected to prevent organisms from falling on the beach. A total of 12.5 m3 of biofouling was deposited in landfill following regulations for fishing discard material. In addition, qualitative and quantitative fouling samples were obtained from different hull locations of the vessel, including niche areas. A total of 53 distinct taxa were identified, including 18 exotic species for Argentina, 7 of which had not been previously reported for the study area. Cleaning by beaching can be used as a convenient biosecurity method to remove hull biofouling from small and medium size vessels when other methods or facilities on the coast are not available. Our results also provide further evidence for the potential risk of recreational vessels as vectors for the secondary spread of marine exotic species.Fil: Castro, Karen Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Grupo de Ecología en Ambientes Costeros (GEAC); Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Giachetti, Clara Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Grupo de Ecología en Ambientes Costeros (GEAC); Argentina. Universidad de Buenos Aires; ArgentinaFil: Battini, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Grupo de Ecología en Ambientes Costeros (GEAC); Argentina. Universidad de Buenos Aires; ArgentinaFil: Bortolus, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Grupo de Ecología en Ambientes Costeros (GEAC); ArgentinaFil: Schwindt, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Grupo de Ecología en Ambientes Costeros (GEAC); Argentin

Delivery in pregnant women infected with SARS-CoV-2: A fast review

Background: Few case reports and clinical series exist on pregnant women infected with SARS-CoV-2 who delivered. Objective: To review the available information on mode of delivery, vertical/peripartum transmission, and neonatal outcome in pregnant women infected with SARS-CoV-2. Search strategy: Combination of the following key words: COVID-19, SARS-CoV-2, and pregnancy in Embase and PubMed databases. Selection criteria: Papers reporting cases of women infected with SARS-CoV-2 who delivered. Data collection and analysis: The following was extracted: author; country; number of women; study design; gestational age at delivery; selected clinical maternal data; mode of delivery; selected neonatal outcomes. Main results: In the 13 studies included, vaginal delivery was reported in 6 cases (9.4%; 95% CI, 3.5\u201319.3). Indication for cesarean delivery was worsening of maternal conditions in 31 cases (48.4%; 95% CI, 35.8\u201361.3). Two newborns testing positive for SARS-CoV-2 by real-time RT-PCR assay were reported. In three neonates, SARS-CoV-2 IgG and IgM levels were elevated but the RT-PCR test was negative. Conclusions: The rate of vertical or peripartum transmission of SARS-CoV-2 is low, if any, for cesarean delivery; no data are available for vaginal delivery. Low frequency of spontaneous preterm birth and general favorable immediate neonatal outcome are reassuring