Near-real-time VTEC maps: New contribution for Latin America Space Weather Mendoza, Luciano Pedro Oscar; Meza, Amalia Margarita; Aragón Paz, Juan Manuel The development of regional services able to provide ionospheric vertical total electron content (VTEC) maps and ionospheric indexes with a high spatial resolution, and in near-real-time, are of great importance for both civilian applications and the research community. We provide here the methodologies, and an assessment, of such a system. It relies on the public Global Navigational Satellite Systems (GNSS) infrastructure in South America, incorporates data from multiple constellations (currently GPS, GLONASS, Galileo and BeiDou), employs multiple frequencies, and produces continental wide VTEC maps with a latency of just a few minutes. To assess the ability of our system to model the ionospheric behavior we performed a year-round intercomparison between our near-real-time regional VTEC maps, and VTEC maps of verified quality produced by several referent analysis centers, resulting in mean biases lower than 1 TEC units (TECU). Also, the evaluation of our products against direct and independent GNSS-based slant TEC measurements shows RMS values better than 1 TECU. In turn, ionospheric weather W-index maps were generated, for calm and disturbed geomagnetic scenarios, solely employing our quality verified VTEC maps. The spatial representation of these W-index maps reflects the state of the ionosphere, with a resolution of 0.5×0.5 degrees. Finally, we conclude that our products, computed every 15 min, do provide an excellent spatial representation of the regional TEC, and are able to provide the bases for the possible computation of ionospheric W-index maps, also in near-real-time.

A cell-free approach with a supporting biomaterial in the form of dispersed microspheres induces hyaline cartilage formation in a rabbit knee model Zurriaga Carda, Javier; Lastra, María Laura; Antolinos Turpin, Carmen M.; Morales Román, Rosa M.; Sancho Tello, María; Perea Ruiz, Sofía; Milián, Lara; Fernández, Juan Manuel; Cortizo, Ana María; Carda, Carmen; Gallego Ferrer, Gloria; Gómez Ribelles, José L. The objective of this study was to test a regenerative medicine strategy for the regeneration of articular cartilage. This approach combines microfracture of the subchondral bone with the implant at the site of the cartilage defect of a supporting biomaterial in the form of microspheres aimed at creating an adequate biomechanical environment for the differentiation of the mesenchymal stem cells that migrate from the bone marrow. The possible inflammatory response to these biomaterials was previously studied by means of the culture of RAW264.7 macrophages. The microspheres were implanted in a 3 mm-diameter defect in the trochlea of the femoral condyle of New Zealand rabbits, covering them with a poly(l-lactic acid) (PLLA) membrane manufactured by electrospinning. Experimental groups included a group where exclusively PLLA microspheres were implanted, another group where a mixture of 50/50 microspheres of PLLA (hydrophobic and rigid) and others of chitosan (a hydrogel) were used, and a third group used as a control where no material was used and only the membrane was covering the defect. The histological characteristics of the regenerated tissue have been evaluated 3 months after the operation. We found that during the regeneration process the microspheres, and the membrane covering them, are displaced by the neoformed tissue in the regeneration space toward the subchondral bone region, leaving room for the formation of a tissue with the characteristics of hyaline cartilage.

Inferring the occurrence of regime shifts in a shallow lake during the last 250 years based on multiple indicators Gonzalez Sagrario, Maria de Los Angeles; Musazzi, Simona; Cordoba, Francisco Elizalde; Mendiolar, Manuela; Lami, Andrea Regime shifts are ecosystem-scale phenomena. In lake studies, most supporting evidence is frequently based on a single state variable. We examined the sediment record of the shallow lake Blanca Chica (Argentina) to explore the response of multiple proxies belonging to different trophic levels (nutrients, chlorophyll and carotenoid pigments, diatoms, Cladocera remains, and Rotifera resting eggs) over the last 250 yr. We explored different ecological indicators to assess changes consistent with regime shifts. To do so, first we identified the timing of transitional periods on multiple-proxies. Then, we explored (1) the nature of the change (linear versus non-linear dynamics), (2) different indicators of a shift across the food web: multimodality and resilience indicators (standard deviation and autocorrelation), and (3) examined the synchronicity of the detected indicators at multiple-trophic levels. Generalized additive models fitted to the ordination scores of the assemblages analyzed revealed two transitions: ca. 1860–1900, and 1915–1990. Ecological indicators of regime shifts revealed that the first transition is consistent with a threshold state response (change in the ecosystem state manifest as a jump when the driver exceeds a state threshold), and the second one with a critical transition (hysteretic transition in which the system change to an alternate stable state). After the first transition lake structure shifted from littoral to pelagic species dominance (evidenced by Cladocera and diatom assemblages), and turbidity increased, indicating a rise in lake water level. This transition was non-linear, showed multimodality, and is most likely driven by an increase in precipitation registered in the region since 1870. During the second transition, nutrient levels rose, all indicators showed multimodality, non-linear dynamics and an increase in standard deviation prior to the regime shift. These dynamics are consistent with a critical transition in response to eutrophication, and coincides with a post-1920 change in land use. Our results show that several ecological indicators of regime shifts need to be examined to perform an accurate diagnosis. We highlight the relevance of a multi-proxy approach including multiple-trophic level responses as the appropriate scale of analysis to determine the occurrence, type and dynamics of regime shifts. We also show that resilience indicators and critical transitions can be detectable in the whole food web and that shallow lakes can undergo different types of regime shifts.

Flash and grab: Deep-diving southern elephant seals trigger anti-predator flashes in bioluminescent prey Goulet, Pauline; Guinet, Christophe; Campagna, Claudio; Campagna, Julieta; Tyack, Peter Lloyd; Johnson, Mark Bioluminescence, which occurs in approximately 80% of the world's mesopelagic fauna, can take the form of a low-intensity continuous glow (e.g. for counter-illumination or signalling) or fast repetitions of brighter anti-predatory flashes. The southern elephant seal (SES) is a major consumer of mesopelagic organisms, in particular the abundant myctophid fish, yet the fine-scale relationship between this predator's foraging behaviour and bioluminescent prey remains poorly understood. We hypothesised that brief, intense light emissions should be closely connected with prey strikes when the seal is targeting bioluminescent prey that reacts by emitting anti-predator flashes. To test this, we developed a biologging device containing a fast-sampling light sensor together with location and movement sensors to measure simultaneously anti-predator bioluminescent emissions and the predator's attack motions with a 20 ms resolution. Tags were deployed on female SES breeding at Kerguelen Islands and Peninsula Valdés, Argentina. In situ light levels in combination with duration of prey capture attempts indicated that seals were targeting a variety of prey types. For some individuals, bioluminescent flashes occurred in a large proportion of prey strikes, with the timing of flashes closely connected with the predator's attack motion, suggestive of antipredator emissions. Marked differences across individuals and location indicate that SES do exploit bioluminescent organisms but the proportion of these in the diet varies widely with location. The combination of wideband light and acceleration data provides new insight into where and when different prey types are encountered and how effectively they might be captured.

Back to the bases: Building a terrestrial water δ18O baseline for archaeological studies in North Patagonia (Argentina) Serna, Alejandro; Prates, Luciano Raúl; Valenzuela, Luciano Oscar; Salazar García, Domingo C. Archaeology has been using stable oxygen as an isotopic tracer linked with water consumption for decades, and it has been demonstrated to be a powerful tool to assess paleomobility in bioarchaeology. Central-eastern North Patagonia (Argentina) is an especially appropriate region to apply it since it presents a high density of huntergatherer burials, it was a nodal zone criss-crossed by an extensive network of important routes, and it is characterized by a high environmental fragmentation due to the scarcity of fresh water sources. The aim of this paper is to build an empirical stable oxygen isotope baseline of terrestrial surface waters to assess the potentiality of tracing past human movement. We analyzed 46 water samples from 13 locations with permanent sources (rivers, springs, streams), compared it with predictions of precipitation and evaluated it considering seasonal variation, altitude and distance from the coast. Our results show that different post-precipitation processes change the isotopic signal from the sources with respect to the local precipitation, and highlight the relevance of analyzing terrestrial water sources. According to their oxygen isotope values we defined five hydrologic zones: Colorado River, Negro River, Closed Basins and Plains, Eastern and Western Somuncurá Foothills. Their identification shows the potential to address past human movement using stable oxygen water baselines in central-eastern North Patagonia.

Arsenic in Latin America: A critical overview on the geochemistry of arsenic originating from geothermal features and volcanic emissions for solving its environmental consequences Morales-Simfors, Nury; Bundschuh, Jochen; Herath, Indika; Inguaggiato, Claudio; Caselli, Alberto Tomás; Tapia, Joseline; Choquehuayta, Fredy Erlingtton Apaza; Armienta, María Aurora; Ormachea, Mauricio; Joseph, Erouscilla; López, Dina L. Geothermal fluids and volcanic emissions are important sources of arsenic (As), resulting in elevated concentrations of As in ground-, surface-water and soil, which may adversely affect the environment. Arsenic originating from geothermal features and volcanic activities is common in Latin America forming a serious threat to the livelihoods of millions of people. This review attempts to provide a critical overview of the geochemistry of As originating from these sources in Latin America to understand what information exists about and what future research needs to be undertaken. This study evaluated 15 countries in Latin America. In total, 423 sites were characterized with As originating from geothermal sources, mostly related to present volcanic activity (0.001 < As<73 mg/L, mean: 36.5 mg/L) and the transboundary Guarani Aquifer System (0.001 < As<0.114 mg/L, mean: 0.06 mg/L). Many of the geothermal systems and volcanoes discussed in this study are close to densely populated cities, including Bogota, Managua, San José, Guatemala City and Mexico City, where total As concentrations in natural ground- and surface- water exceed the safe drinking water guideline of 0.01 mg/L, recommended by the World Health Organization (WHO). However, the wide geographical occurrence of As in geothermal fluids and volcanic emissions of this region is by far not fully understood, so that development of geographical maps based on geographic information system (GIS) is an urgent necessity to understand the real nature of the problem. The assessment of environmental risks and the potential impacts on human health both inadequate and scarce and hence, these gaps need to be addressed by future research. The present holistic assessment of As originating from geothermal features and volcanic emissions would be a driving force to formulate a plan for establishing a sustainable As mitigation in vulnerable areas of Latin America in the near future. An assessment of the geochemistry, mobility and distribution of As would augment the effectiveness of the plan.

Hepatitis C Virus (HCV) Clearance After Treatment With Direct-Acting Antivirals in Human Immunodeficiency Virus (HIV)-HCV Coinfection Modulates Systemic Immune Activation and HIV Transcription on Antiretroviral Therapy Ghiglione, Yanina Alexandra; Polo, Maria Laura; Urioste, Alejandra; Rhodes, Ajantha; Czernikier, Alejandro; Trifone, César Ariel; Quiroga, María Florencia; Sisto, Alicia; Patterson, Patricia; Salomon, Horacio Eduardo; Rolon, Maria Jose; Bakkour, Sonia; Lewin, Sharon R.; Turk, Gabriela Julia Ana; Laufer, Natalia Lorna Background Hepatitis C virus (HCV) coinfection among people with human immunodeficiency virus (HIV) might perturb immune function and HIV persistence. We aimed to evaluate the impact of HCV clearance with direct-acting antivirals (DAAs) on immune activation and HIV persistence in HIV/HCV-coinfected individuals on antiretroviral therapy (ART). Methods In a prospective observational study, ART-treated participants with HIV/HCV coinfection received sofosbuvir/daclatasvir ± ribavirin (n = 19). Blood samples were collected before DAA therapy, at the end of treatment, and 12 months after DAA termination (12MPT). T- and natural killer (NK)-cell phenotype, soluble plasma factors, cell-associated (CA)-HIV deoxyribonucleic acid (DNA) forms (total, integrated, 2LTR), CA-unspliced (US) and multiple-spliced ribonucleic acid (RNA), and plasma HIV RNA were evaluated. Results Hepatitis C virus clearance was associated with (1) a downmodulation of activation and exhaustion markers in CD4+, CD8+ T, and NK cells together with (2) decreased plasma levels of Interferon gamma-induced protein 10 (IP10), interleukin-8 (IL-8), soluble (s)CD163 and soluble intercellular adhesion molecule (sICAM). Cell-associated US HIV RNA was significantly higher at 12MPT compared to baseline, with no change in HIV DNA or plasma RNA. Conclusions Elimination of HCV in HIV/HCV-coinfected individuals alters immune function and the transcriptional activity of latently infected cells. This report provides insights into the effects of HCV coinfection in HIV persistence and regards coinfected subjects as a population in which HIV remission might prove to be more challenging.

Fogones, combustible óseo y procesamiento faunístico en el sitio de Huencú Nazar (Sistema Lagunar Hinojo-Las Tunas, región pampeana, Argentina): Implicancias para el uso del espacio por cazadores-recolectores Scheifler, Nahuel Alberto Huncú Nazar, an open-air archaeological site occupied during the Late Holocene (ca. 3000 years BP), is located on the shore of a shallow lake from the Hinojo-Las Tunas Shallow Lake System in the Pampean region of Argentina. Within an area of 5,000 m2 are distributed 22 hearths, caches of rocks, and concentrations of granitoid rocks. In one of the excavated sectors, researchers identified hearths with concave bases and the use of bones of Lama guanicoe (Artiodactyla, Camelidae) as fuel. In this way, the inhabitants solved the problem of accumulating animal waste that would have otherwise affected their standards of living. They also deposited materials related to subsistence and technology around the hearths.; Huencú Nazar es un sitio arqueológico a cielo abierto localizado en el Sistema Lagunar Hinojo-Las Tunas (región pampeana, Argentina) que fue ocupado durante el Holoceno tardío (ca. 3000 aP). En un área de 5.000 m2 se distribuyen 22 fogones, escondrijos de roca y concentraciones de rocas granitoides. En uno de los sectores excavados se registraron fogones en cubeta y el uso de huesos de Lama guanicoe (Artiodactyla, Camelidae) como combustible. El uso de combustible óseo permitió solucionar el problema de los residuos molestos para la comodidad de las personas ubicadas alrededor de los fogones. En torno a las estructuras de combustión se depositaron materiales relacionados con la subsistencia y la tecnología.

La guerra de las curvas: pandemia, sensibilidades y estructuración social; The war of the curves: pandemic, sensibilities, and social structuration; A guerra das curvas: pandemia, sensibilidades e estruturação social Scribano, Adrián Oscar El presente artículo tiene por objetivo presentar algunos de los componentes básicos del escenario donde la guerra de las curvas se desarrolla y que permiten aproximarse a la Pandemia como un fenómeno epistémico que implica re-estructuración de una política de la sensibilidad planetaria. Para lograr dicho objetivo hemos seguido la siguiente estrategia: a) se expone brevemente la conexión entre Verdad, Curvas y Hechos; b) se explicita la comprensión del origen de la Pandemia; c) se expone la “metáfora bélica” utilizada en el “combate” contra la Pandemia; d) se propone una mirada para la situación de planetarización; e) se indaga sobre el estado de la “razón europea”; f) se analiza los efectos de la distancia social; g) se presenta la preponderancia de las redes sociales en la vida cotidiana; h) se reflexiona sobre el “sentido de emergencia” de la Pandemia; e i) se abren algunas postales para seguir pensando. Se termina el articulo abogando por seguir indagando las cientos de miles de prácticas intersticiales que se performan en Pandemia como unas huellas que permiten ver los caminos de salida para una humanidad acorralada.

Parasite-host glycan interactions during Trypanosoma cruzi infection: trans-Sialidase rides the show Campetella, Oscar Eduardo; Buscaglia, Carlos Andres; Mucci, Juan Sebastián; Leguizamon, Maria Susana Many important pathogen-host interactions rely on highly specific carbohydrate binding events. In the case of the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, glycointeractions involving sialic acid (SA) residues are pivotal for parasite infectivity, escape from immune surveillance and pathogenesis. Though unable to synthesize SA de novo, T. cruzi displays a unique trans-Sialidase (TS) enzyme, which is able to cleave terminal SA residues from host donor glycoconjugates and transfer them onto parasite surface mucins, thus generating protective/adhesive structures. In addition, this parasite sheds TS into the bloodstream, as a way of modifying the surface SA signature, and thereby the signaling/functional properties of mammalian host target cells on its own advantage. Here, we discuss the pathogenic aspects of T. cruzi TS: its molecular adaptations, the multiplicity of interactions in which it is involved during infections, and the array of novel and appealing targets for intervention in Chagas disease provided by TS-remodeled sialoglycophenotypes.

Morphology of the mandibular gnathobases of the copepods Calanus australis and Calanoides carinatus: Evidence of omnivory D'Agostino, Valeria C.; Hoffmeyer, Mónica S.; Degrati, Mariana In spite of the worldwide ecological relevance of Calanus australis and Calanoides carinatus, little is known on the morphology of their mandibular gnathobase edges (MGEs). Thus, in order to further learn about the relationship between MGEs and diet, adults and copepodites of C. australis and C. carinatus collected from northern Patagonian coasts, Argentina, were morphologically analyzed using confocal laser scanning microscopy in transmission mode and scanning electron microscopy. In C. australis males as well as in C. australis and C. carinatus females, MGEs were found to end in one dorsal seta and to have one ventral tooth, four central teeth and three dorsal teeth. In contrast, in C. carinatus males, MGEs were observed to be rudimentary and with no dorsal seta, and −contrary to published data− they were found to have three cone-shaped, short and small tooth-like structures and three-four tooth-like structures that were long and pointed. The main differences between MGEs from copepodites and adults of C. australis and C. carinatus females lied in the number of cuspids observed on the different teeth and the presence of a short inner lateral peak found only in C. australis ventral tooth. Overall, the evidence gathered from our study leads us to classify C. australis and C. carinatus as omnivores.

Effect of plant nutritional traits on the diet of grasshoppers in a wetland of Northern Patagonia Amadio, María Emilia; Pietrantuono, Ana Laura; Lozada, Mariana; Fernandez Arhex, Valeria Cristina Dichroplus maculipennis is one of the most damaging grasshoppers of wetlands. We investigated their feeding behavior in relation to the most abundant plants of Patagonian wetlands. Results showed that D. maculipennis was able to select its food resources and displayed a mixed diet. The most consumed plant was Taraxacum officinale, which contains a large amount of protein and water. However, consumption decreased when offered simultaneously with Juncus balticus and Holcus lanatus. Therefore, diet varied according to the supply of plants that were offered. In future studies, it would be interesting to analyze the influence of diet on performance.

Sixty years of hail suppression activities in Mendoza, Argentina: Uncertainties, gaps in knowledge and future perspectives Rivera, Juan Antonio; Otero, Federico; Naranjo Tamayo, Elizabeth Beatríz; Silva, Martín This paper provides a perspective based on the evaluation of scientific evidence of hail suppression activities in Mendoza, Argentina. The province of Mendoza was home to several cloud-seeding projects over the years intended to prevent hail damage to agriculture. Those projects were motivated by the paramount importance of wine production for the regional and national economy. We discuss the uncertainties and gaps in knowledge identified in the results from the hail suppression activities, framing the available research over the study area on a global context. The results of this study indicate that there is no unequivocal scientific evidence that proves a statistically significant reduction of hail frequency and size as a consequence of hail suppressing activities in Mendoza. Such lack of evidence questions the reliability of the projects after almost 60 years of cloud seeding. By analyzing the existing gaps in knowledge in terms of observations, modeling evaluations and understanding of severe convective systems, the study provides a description of future directions and alternatives for hail damage mitigation that need a better science-policy integration. This study can be replicated in other regions where hail suppressing activities are taking place.

Earthworms to improve glyphosate degradation in biobeds Lescano, Maia Raquel; Masin, Carolina Elisabet; Rodriguez, Alba Rut; Godoy, José Luis; Zalazar, Cristina Susana In this work, earthworm effect on the efficiency of biobeds for glyphosate degradation was studied. Three biomixtures with and without the addition of earthworms (Eisenia fetida species) were evaluated. The initial concentration of glyphosate was 1000 mg/kg biomixture. Glyphosate and biological parameters were measured as a function of time. Earthworm survival, biomass, and reproduction were evaluated as well. All biomixtures that contain earthworms reached 90% of glyphosate degradation at 90 days in comparison with the biomixtures without earthworms that reached 80% approximately at the same time.Also, within the biomixtures that contained earthworms, glyphosate degradation rate was significantly higher in the one made up with soil and wheat stubble (Ws-E) showing excellent capacity for aminomethylphosphonic acid (AMPA) degradation, the mainmetabolite of glyphosate degradation. In addition, a study performed after the vermiremediation process showed that E. fetida can tolerate high glyphosate concentration without modifications in its life traits. It can be concluded that the use of E. fetida withinthe biobeds is an excellent combination to improve glyphosate and AMPA removal.

Short-term effects of whale watching boats on the movement patterns of southern right whales in Península Valdés, Patagonia, Argentina Chalcobsky, Bárbara Ailen; Crespo, Enrique Alberto; Coscarella, Mariano Alberto Whale watching in Patagonia began in 1973, with the southern right whale (Eubalaena australis) as a target. Thus far, only short-term effects of whale watching on behaviour have been evaluated. The southern right whale population is increasing locally and expanding to adjacent areas. We evaluated boat effects on the biological system through the analysis of breathing rate, linearity, reorientation rate and total distance travelled. Short-term movement patterns of SRW in the area are not severely affected by whale watching operations in Puerto Pirámide at this level of activity. However, significant changes in breathing rates in the presence of boats deserve further attention considering that whales return the same location. In light of the present work, the whales that breed at Península Valdés may be tolerant to whale watching boats.

Propuesta metodológica para definir unidades locales de gestión para el ordenamiento territorial rural; Methodological proposal to define management units for rural land‐use planning Sales, Romina Giselle Actualmente en Latinoamérica existe una creciente preocupación por la planificación de los territorios rurales, particularmente en el marco del ordenamiento territorial. Sin embargo, las particularidades de los territorios rurales construidas por los actores locales aún no han sido atendidas en profundidad. En este artículo definimos los conceptos de territorio y capital social para analizar las redes sociales y la manera en que son percibidas por los actores con el fin de elaborar una propuesta metodológica para definir unidades locales de gestión para el ordenamiento territorial rural. La metodología consta de 4 etapas que, a través de técnicas de recolección cualitativas y cuantitativas y análisis de datos basado en la codificación, permite definir los límites analíticos de la unidad a través de un sistema de información geográfico. Para aplicar la metodología seleccionamos un estudio de caso en el departamento de Santa Rosa, Mendoza-Argentina. Sostenemos que al incorporar la unidad local de gestión en el diseño de políticas territoriales es posible atender las singularidades que inscriben los actores locales en territorios rurales. De esta manera, la planificación territorial podría enriquecer sus acciones al abordar la escala local, es decir, al considerar como unidad de análisis a los sujetos y sus redes.; Currently, in Latin America, there is a growing concern for the planning of rural territories, particularly in the context of land use planning. However, the distinctive features of the rural territories which are built by the local actors have not yet been addressed in depth. In this article, we define the concepts of territory and social capital to analyze the social networks and how the actors perceive them in order to elaborate a methodological proposal to define local management units for rural land use planning. The methodology consists of four stages that, through qualitative and quantitative techniques and data analysis based on coding, enables the definition of the analytical limits of the unit with the support of a geographical information system. To apply the methodology, we selected a case study in the department of Santa Rosa, Mendoza-Argentina. The consideration of the local management unit in the design of land use policies allows addressing the singularities that local actors express in rural territories. In this way, land use planning could be enriched by approaching the local scale, that is, by considering subjects and their networks as analysis units.

On Schatten restricted norms Miglioli, Martín Carlos We consider norms on a complex separable Hilbert space such that ⟨aξ,ξ⟩≤‖ξ‖2≤⟨bξ,ξ⟩ for positive invertible operators a and b that differ by an operator in the Schatten class. We prove that these norms have unitarizable isometry groups, our proof uses a generalization of a fixed point theorem for isometric actions on positive invertible operators. As a result, if their isometry groups do not leave any finite dimensional subspace invariant, then the norms must be Hilbertian. That is, if a Hilbertian norm is changed to a close non-Hilbertian norm, then the isometry group does leave a finite dimensional subspace invariant. The approach involves metric geometric arguments related to the canonical action on the non-positively curved space of positive invertible Schatten perturbations of the identity.

Achievements and challenges in the use of metronomics for the treatment of breast cancer Scharovsky, Olga Graciela; Rico, Maria Jose; Mainetti, Leandro Ernesto; Perroud, Herman Andrés; Rozados, Viviana Rosa Two interesting therapeutic proposals for cancer treatment emerged at the beginning of the 21st century. The first one was metronomic chemotherapy, which refers to the chronic administration of chemotherapeutic agents, in low doses, without extended drug-free periods. Then, the idea of drug repositioning in oncology, the use of well-known drugs that were created for other uses to be utilized in oncology, gained strength. Shortly after, the two strategies were merged in one, named metronomics. Both approaches share several features which make metronomics an appealing choice for cancer treatment: use of known and approved drugs, thus diminishing the time necessary to enter to the clinic, therapeutic effect, low toxicity, oral administration, better life quality, low costs because of the use of, generally, out of patent drugs, possibility of use, even in countries with very low economic resources.Many chemotherapy and repurposed drugs were tested with metronomics approaches for the treatment of mammary cancer, the most common malignancy in women worldwide, leading to high rates of mortality. The wide range of therapeutic models studied, paralleled the wide range of responses obtained, like tumor growth and metastasis inhibition, overall survival increase, lack of toxicity, better life quality, among others. The accomplishments reached, and the challenges faced by researchers, are discussed.

Two new species of Gyrodactylus von Nordmann, 1832 parasitizing Cnesterodon decemmaculatus (Poeciliidae) from the southern limit of the family in the Neotropical region Taglioretti, Verónica; García Vásquez, Adriana; Rossin, Maria Alejandra; Pinacho Pinacho, Carlos Daniel; Rubio Godoy, Miguel; Timi, Juan Tomas In this study, we followed an integrative taxonomy approach to describe two new species of Gyrodactylus von Nordmann, 1832, and to identify specimens of G. breviradix Vega, Razzolini, Arbetman, and Viozzi, 2019, all three collected from ten spotted live-bearer Cnesterodon decemmaculatus (Jenyns, 1842), an endemic and widespread poeciliid from the Pampean region, which is the southernmost occurring species of the Poeciliidae in the Americas. Gyrodactylids were first characterized morphologically and mophometrically, and when possible, sequences of the Internal Transcribed Spacers (ITS1-5.8S-ITS2) and the cytochrome oxidase II (COII) were used to delimit species. Gyrodactylus breviradix, Gyrodactylus marplatensis n. sp., and Gyrodactylus pampeanus n. sp. were found on the fins and body surface of C. decemmaculatus in La Tapera Creek, Mar del Plata, Buenos Aires province, Argentina. A phylogenetic analysis combining newly generated sequences of one of the new species, G. marplatensis n. sp., and of G. breviradix, along with those available in GenBank for a further 36 species of Gyrodactylus, revealed that G. marplatensis n. sp. is a sister taxon of Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, and Viozzi, 2019. Genetic distances for the ITS and COII gene were estimated among Gyrodactylus spp. and further supported the validity of the new species. Overall, morphometric and molecular data coincided in delimiting the new taxa, thus demonstrating the value of integrative taxonomy for the erection of new species of Gyrodactylus and species identification.

A new species of Ameloblastella Kritsky, Mendoza-Franco & Scholz, 2000 (Monogenoidea: Dactylogyridae) from South American freshwater catfishes (Siluriformes: Pimelodidae) Mendoza Palmero, Carlos A.; Rossin, Maria Alejandra; Irigoitia, Manuel Marcial; Scholz, Tomáš Ameloblastella martinae n. sp. is described from the gills of the pimelodid catfishes (Siluriformes: Pimelodidae) Sorubim lima (Bloch & Schneider) (type-host) and Hemisorubim platyrhynchos(Valenciennes) in the Peruvian Amazonia, and on Pseudoplatystoma corruscans (Spix & Agassiz) and P. recticulatum Eigenmann & Eigenmann in Argentina. The new species is distinguished from other congeners mainly by the morphology of the male copulatory organ (MCO), which has a form of acorkscrew with tight rings, whereas in other species of Ameloblastella Kritsky, Mendoza-Franco & Scholz, 2000, the MCO is formed by a delicate and coiled tube forming loose rings. Sclerotised structures (haptoral elements and MCO) of specimens of A. martinae n. sp. were used to compare two parasite populations (from Peru and Argentina) using Euclidean distances. Despite the geographical isolation and different hostassociations, both populations belong to the same species. The phylogenetic position of A. martinae n. sp. was analysed using partial sequences of the 28S mrDNA gene along with 46 species of dactylogyrid parasites of siluriforms (Siluriformes) under Maximum Likelihood (ML) and Bayesian Inference (BI) criteria. Phylogenetic reconstructions showed that Ameloblastella represented by five species, including its type-species A. chavarriai (Price, 1936) from the heptapterid Rhamdia guatemalensis and A. martinaen. sp., was recovered as a well-supported monophyletic group (in both analyses, ML and BI). An additional species, Ameloblastella sp., was found on P. corruscans and P. reticulatum in Argentina. The morphology of the MCO and haptoral elements suggests that Ameloblastella sp. may represent a new species. However, the few specimens found and the lack of genetic sequences of this species precluded its formal description.