Facultad De Ciencias Exactas Research Articles

Experimental project for monitoring students in the different academic degree programs of the Facultad de Ciencias Exactas y Naturales (FACEN), at the National University of Asuncion (UNA), San Lorenzo

Este trabajo se realizó con la finalidad de disponer de datos confiables y oportunos que colabore en mejorar las estrategias de gestión académica a nivel de Departamentos de carrera, mediante el acceso a los elementos de orientación académica que permitan posteriormente la identificación de indicadores estadísticos de monitoreo y seguimiento académico e implementación de acciones que permitan el egreso oportuno de los estudiantes de las diferentes carreras de grado de la FACEN. El estudio se realizó con 3 (tres) Departamentos de Carrera con su estructura organizacional: Matemática, Estadística y Química. La investigación es de tipo cuantitativo, con un diseño explicativo, longitudinal y no experimental. La información se recolectó a partir de datos secundarios (informes de eficacia y eficiencia) y la encuesta a 6 (seis) gestores académicos sobre la percepción de utilidad del programa, los cuales fueron analizados según el cumplimiento de los objetivos del programa de seguimiento a estudiantes y la percepción de utilidad. Los resultados demostraron que los gestores académicos tengan la percepción de que constituyen en aspectos significativos para el cumplimiento de sus funciones y el compromiso de realizar la orientación académica al estudiante por permanecer en el programa académico que cursa. En la medida que las capacidades y la gestión de apoyo sean positivas, los estudiantes contarán con interacciones favorables que apoyarán su participación a nivel institucional, lo cual favorecerá su desarrollo intelectual y académico. Finalmente, se concluye que a nivel de política institucional resulta relevante gestionar el apoyo de las capacidades y la adaptación de los estudiantes, ya que se contribuirá en la generación de un equilibrio positivo entre la integración académica y social, a partir de la configuración de elementos que apoyarán el desarrollo de un contexto de motivación que permitirá mantener el compromiso de los estudiantes por el logro del egreso oportuno.

Chordal graphs through clique trees

Here we present a part of the work in collaboration with Jayme Luiz Szwarcfiter and Marisa Gutierrez, during the development of the thesis of Silvia Tondato at Facultad de Ciencias Exactas (UNLP), "Grafos Cordales: árboles cliques y representaciones canónicas'', finished in 2009.

Los inicios y primeros logros de la Red UNA STEM

The Red UNA STEM is a network founded by four professors from two faculties of the Universidad Nacional (UNA): Facultad de Ciencias Exactas y Naturales and Facultad de Ciencias de la Tierra y el Mar. This project aims to permeate and promote scientific knowledge and skills in children and adolescents, making an important effort in the inclusion of gender issues in many of the activities organized, in addition to generate and publicize learning opportunities in the scientific area, as well as promoting STEM careers and research projects among students and faculty members from the UNA. In this paper, we summarize the experiences of this network during the first year of its creation, in order to promote the creation of similar initiatives to reach the general public and provide spaces for children, adolescents and adults to learn about technology and science through the use of different tools as Scratch Jr., Scratch and Open Roberta as well as interact with scientific content and with the people doing scientific research.

Tightening Bonds in Latin America Through Phage Discovery.

Between 2015 and 2019, we hosted an International Phage Course at Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina. The 2-week full-time course was hands-on and included lectures from renowned phage biologists. Participating students were able to meet and discuss with recognized experts from around the world in a familiar setting, facilitating the establishment of scientific collaborations and the expansion of their networks. Eighty-four students from 14 Latin American countries have participated in the course, which included isolation, characterization, genome sequencing, and annotation of novel phages. We have successfully created a coursework that enabled the acquisition of new knowledge and expertise in bacteriophage biology and strengthened ties among Latin American colleagues.

Fortalecimiento de las capacidades de diagnóstico e investigación del Laboratorio de Salud Pública de la Facultad de Ciencias Exactas (UNLP), integrado a la red de diagnóstico de SARS-CoV-2 de la Provincia de Buenos Aires

Desde que se informó el primer caso de enfermedad por COVID-19 en China, en diciembre de 2019, y se declaró la crisis sanitaria y luego la pandemia, los sistemas de Salud debieron adaptar sus estructuras para realizar diagnóstico, vigilancia, monitoreo de la respuesta inmune y evaluación de la protección inmune post-infección o post-vacunación. En este escenario el Grupo COVID Exactas, a través del Laboratorio de Salud Pública, de la Secretaría de Extensión de la Facultad de Ciencias Exactas, montó un laboratorio de diagnóstico para realizar la detección del RNA viral en muestras de pacientes mediante su amplificación RT-qPCR. Para paliar la falta de disponibilidad de reactivos y simplificar la extracción del RNA se encaró el desarrollo de un sistema basado en nanopartículas magnéticas recubiertas de sílice, que no requieren el uso de centrifuga. Al mismo tiempo, el grupo Serología comenzó a monitorear anticuerpos séricos IgG específicos, mientras que el grupo Investigación comenzó a desarrollar inmunoensayos para detección de IgG/IgM/IgA específicos y caracterización de espectros infrarrojo y fluorescente en muestras de orina. En este contexto de gravedad sanitaria la UNLP y el Ministerio de Salud de la Provincia de Buenos Aires (PBA) firmaron un convenio de cooperación y trabajaron en la adecuación de laboratorios, coordinación de distribución de muestras, provisión de reactivos e insumos y diseño de estrategias conjuntas de vigilancia para aportar soluciones al sistema de salud en el contexto de pandemia. Asimismo, el interés del Gobierno de la PBA por los desarrollos de los institutos de la UNLP y de doble dependencia UNLP-CONICET, dio lugar a otro convenio tripartito con finalidades específicas.

Age correlations for the Acoite Formation (Lower Ordovician) at Aguas Blancas Creek in the Cordillera Oriental of Jujuy Province, Argentina

Here, we use conodont and graptolite assemblages to age correlate the ‘Sepulturas limestones’ facies of the Acoite Formation exposed at Aguas Blancas Creek, near Altos de Lipán in the Cordillera Oriental of Jujuy Province, Argentina. An association of autochthonous conodont species is identified consisting of Drepanodus arcuatus, Drepanoistodus pitjanti, Erraticodon patu, Gothodus andinus, Paroistodus parallelus and Zentagnathus argentinensis. Tubaria referable to the graptolite genera Acrograptus, Baltograptus and Tetragraptus are also present. This assemblage corresponds to the middle interval of the Gothodus andinus Zone, together with the upper Tetragraptus azkharensis Zone, or possibly the lower Baltograptus cf. B. deflexus Zone, which collectively indicate an early to middle Floian (Early Ordovician) age. Lithological and faunal characteristics of the studied succession imply deposition in a shallow marine environment. We also suggest that the Aguas Blancas section is stratigraphically younger than the other upper outcrops exposed around the town of La Ciénaga, where the ‘Sepulturas limestones’ were originally defined. G.L. Guillermo [guillermo.albanesi@unc.edu.ar], CICTERRA (CONICET-UNC), CIGEA, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611, X5016GCA, Córdoba, Argentina; E.K. Rueda [ruedaroballo@gmail.com ]; G. Ortega [gladyscortega@gmail.com ] Museo de Paleontología, CIGEA, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 300, X5000JJC, Córdoba, Argentina; C.R Monaldi [crmonaldi@gmail.com ], Los Teros 197, 4401 Vaqueros, Salta, Argentina.

Localización e Internet de las Cosas

A unified architecture for indoor and outdoor location determination in the IoT domain is presented in this work. Two empirical scenarios (indoor and outdoor) with their associated techniques have been proposed and successfully deployed. The selected physical location for interior experience has been a classroom of the Facultad de Ciencias Exactas, Químicas y Naturales (FCEQyN) from Universidad Nacional de Misiones (UNaM). The network has been set by deploying a set of Decawave DWM1001 nodes, a new radio frequency communications product from the Decawave ScenSor family that accomplish with communication methods as Ultrawideband (UWB) and Bluetooth Low Energy (BLE). For the outdoor scenario, a livestock production farm of 234 ha (2,34.106 m2) near the city of Posadas has been selected. In this physical facility, devices based on 2.4 GHz XBee Pro S2, compatible with ZigBee and IEEE 802.15.4, have been deployed. For the location process of the nodes, the trilateration method has been used. While in indoors essays an approximate bias of 7.10-2 m has been achieved, outdoors trilateration outcomes expose indeterminacy between 35 m and 98 m.

Catálogo comentado de los materiales tipo de los vertebrados de la Colección Paleontológica de la Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de La Pampa, Argentina

La Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de La Pampa, Santa Rosa, Argentina, custodia una importante colección paleontológica iniciada en el año 1987, cuyo acrónimo es GHUNLPam. En la actualidad, contiene alrededor de 35.000 especímenes de invertebrados, vertebrados, plantas, icnofósiles y palinomorfos, que provienen principalmente de diferentes niveles fosilíferos de la provincia de La Pampa. Se presenta un catálogo del material tipo de la colección de vertebrados, correspondiente en su mayoría a mamíferos del Mioceno tardío de esta provincia. Incluye los holotipos de 15 especies publicados hasta fin del año 2019, siendo cuatro de ellas las especies tipo de los géneros correspondientes. Para cada taxón, se proporciona la información taxonómica actualizada, las sinonimias, la diagnosis original, enmendada o ampliada, según el caso (traducida al español si se publicó originalmente en otro idioma), la localidad tipo, la procedencia geográfica y estratigráfica, y la derivación del nombre del taxón. Finalmente, en algunos casos, se incluyen comentarios taxonómicos adicionales y materiales asignados en la publicación original.

Potential agricultural use of a sub-product (olive cake) from olive oil industries composting with soil

J Pharm Pharmacogn Res 8(1): 43-52, 2020. Original Article Potential agricultural use of a sub-product (olive cake) from olive oil industries composting with soil [Uso agrícola potencial de un subproducto (alperujo) de las industrias del aceite de oliva compostado con suelo] Ariadna Hammann1, Lorena M. Ybañez1, María I. Isla2, Mirna Hilal1,2* 1Centro de Estudios de Especies Vegetales de Interés Regional (CEVIR). Facultad de Ciencias Exactas y Naturales – Universidad Nacional de Catamarca. Belgrano 300, Catamarca capital, Catamarca, Argentina. 2Instituto de Bioprospección y Fisiología Vegetal (INBIOFIV, UNT-CONICET). Facultad de Ciencias Naturales e IML. San Lorenzo 1469, S. M. de Tucumán, Tucumán, Argentina. *E-mail: mhilal@csnat.unt.edu.ar Abstract Context: Olive cake and olive mill wastewater are by-products of olive oil industries. Olive cake is not currently being exploited. Aims: To evaluate the cytotoxicity and genotoxicity induced in Allium cepa root meristems by olive cake in various preparations (aqueous dilutions of olive cake and mixtures of olive cake with soil before and after a composting process). Methods: Olive cake aqueous dilutions as well as fresh and composted olive cake – soil mixtures were obtained. Samples were assayed on Allium cepa L roots and the phenolic content was also determined. Results: Aqueous dilutions showed acute genotoxicity with a mitotic index dramatic reduction and a high number of cell abnormalities. Olive cake induced chromosome aberrations such as bridges, stickiness, and laggard chromosomes and cell aberrations such as strap, folded, giant and binucleated cells. Anomalies increase with polyphenol concentration, both in aqueous dilutions and in mixtures of olive cake – soil without composting. Composted mixtures did not exhibit cell toxicity up to 10% of olive cake although they can decrease the mitotic index, which would produce a reduction in plant growth. Conclusions: Results indicate the varied behavior of olive cake according to sample preparation and suggest the possible use of this by-product incorporated to soils and subjected to composting.

Fungal wood-decay strategies in Nothofagaceae woods from Miocene deposits in southern Patagonia, Argentina

Carlos Daniel Greppi, Juan L. García Massini, Roberto R. Pujana and Sergio A. Marenssi, May 2018. Fungal wood-decay strategies in Nothofagaceae woods from Miocene deposits in southern Patagonia, Argentina. Alcheringa xxx, xxx -xxx.Decayed woods from the Miocene, Rio Leona Formation, Santa Cruz, Argentina having simultaneous decay patterns consistent with soft- and white rot characteristics are described. Samples were previously identified as Nothofagoxylon scalariforme. At low magnification, the permineralized woods appear mottled, with discoloured, degraded areas, scattered in apparently robust tissue, consistent with white-rot decay. At greater magnification, the woods reveal several micromorphological features, including differential decay of cellulose-rich cellular components that match soft-rot decay by extant ascomycetes and some basidiomycetes. In addition, decayed woods either appear differentially delignified or show simultaneous decay of all cellular components (lignin- and cellulose-rich), which are by-products of white-rot fungal decay. Additional anatomical characteristics of the decayed woods are consistent with a host response to the fungal attack. Co-occurrence of these two decay patterns suggests soft-rot decay and white-rot fungal decay. In addition, co-occurrence of all the decay features observed also suggests facultative soft rot by white-rot fungi, such as in some extant species that switch between these two types of decay strategies as a means to circumvent plant defences. These data indicate that fungi with soft-rot capacity for wood decay can be traced back to the early Miocene (ca 19 Ma). In addition, this report adds to the distribution and diversity of fungi in the geological record and underscores the ecological importance of wood as a preferred substrate for the association and interactions between fungi with different saprotrophic abilities, which have been fundamental for nutrient recycling in terrestrial ecosystems during the Cenozoic.Carlos Daniel Greppi [greppi.carlos.d@gmail.com] Museo Argentino de Ciencias Naturales-CONICET, Av. Ángel Gallardo 470, (1405) Ciudad Autónoma de Buenos Aires, Argentina; Juan L. García Massini [massini112@yahoo.com.ar] Centro de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), Provincia de La Rioja, UNLaR, SEGEMAR, UNCa, CONICET, Entre Ríos y Mendoza s/n (5301) Anillaco, La Rioja, Argentina; Roberto R. Pujana [rpujana@gmail.com] Museo Argentino de Ciencias Naturales-CONICET, Av. Ángel Gallardo 470, (1405) Ciudad Autónoma de Buenos Aires, Argentina; Sergio A. Marenssi [smarenssi@hotmail.com] IGEBA-CONICET, Departamento de Geología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Guiraldes 2620, (1428) Buenos Aires, Argentina.

Antiviral activity of A771726, the active metabolite of leflunomide, against Junín virus.

The aim of this study was to investigate the effect of A771726, the active metabolite of leflunomide, (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad against the infection with Junín virus (JUNV), agent of Argentine hemorrhagic fever (AHF). The treatment with non-cytotoxic concentrations of A771726 of Vero and A549 cells infected with JUNV inhibited virus replication in a dose-dependent manner, as determined by virus yield reduction assay. The antiviral effectiveness of A771726 was not importantly affected by the multiplicity of infection and the virus strain. Moreover, the combination of A771726 and ribavirin had a significantly more potent antiviral activity than each single drug treatment. Mechanistic studies showed that the main action of A771726 is exerted before 6 h of JUNV infection. Accordingly, inhibition of viral RNA synthesis was detected in treated infected cells by real time RT-PCR. The exogenous addition of uridine or orotic acid produced a partial reversal of the inhibitory effect of A771726 on infective virus production whereas a total reversion was detected on JUNV RNA synthesis, probably by restoration of the enzymatic activity of dihydroorotate dehydrogenase (DHODH) and the intracellular pyrimidine pools. In conclusion, these results suggest that the antiviral target would be viral RNA synthesis through pyrimidine depletion, but any other effect of the compound on JUNV infection cannot be excluded. This study opens the possibility of the therapeutic application of a wide spectrum host-targeted compound alone or in combination with ribavirin to combat AHF as well as other human pathogenic arenaviruses.

Correction to: Quality Attributes and Shelf Life of High-Pressure Preserved Beef as Affected by Pre-treatment Conditions

The authors would like to add “Facultad de Ciencias Exactas, UNLP, 47 y 115, La Plata, Argentina” as one of the affiliation of Dr. Alicia Califano as this was missed during the publication of the original article.

Understanding reading strategies: eye movements in acquired dyslexia

Understanding reading strategies: eye movements in acquired dyslexia

Preferences and Uses of a Remote Lab from the Students’ Viewpoint

This paper aims to present new evidence and findings that enhance and enrich the knowledge of the preferences and uses of the remote laboratories from the students´ viewpoint. Specifically, the study aims to recognize the students’ preferences in selecting the remote lab as a learning resource, beyond the uses promoted by the professorship. Likewise, we seek to know the reasons given by students that support those preferences. The research was conducted at Facultad de Ciencias Exactas, Ingeniería y Agrimensura (FCEIA), Universidad Nacional de Rosario (UNR), Argentina, by using the “FCEIA-UNR Electronics Physics Remote Lab” and involving almost 300 students in the second year of Electronic Engineering. The lab is integrated into the Learning Management System (LMS) e-ducativa, Facebook and Twitter, allowing the students to log in without additional authentication, both from the virtual classroom or from those social networks. We collected empirical evidence from both, users' opinions and productions, and also, from registers of the remote lab itself, involving more than 4000 successful tests completed on the lab´s database. We achieved both qualitative and quantitative data that allow us to get a comprehensive study from the students’ perspective.

Rainfall intensity modulates the interaction between the marsh cordgrass Spartina densiflora and the mouse Akodon azarae

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 523:71-80 (2015) - DOI: https://doi.org/10.3354/meps11119 Rainfall intensity modulates the interaction between the marsh cordgrass Spartina densiflora and the mouse Akodon azarae Jesús Pascual*, Alejandro D. Canepuccia, Juan Alberti, Pedro Daleo, Oscar Iribarne Instituto de Investigaciones Marinas y Costeras (IIMyC), CONICET - UNMDP, Lab. Ecología, Dpto. Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 573 Correo Central, B7600WAG, Mar del Plata, Argentina *Corresponding author: pascualjesu@gmail.com ABSTRACT: Changes in rainfall patterns caused by anthropogenic global climate change or planetary-scale events, such as the El Niño Southern Oscillation, can significantly affect the abundance and distribution of organisms. Despite the evidence of such effects on marine and terrestrial systems, ecological consequences of rainfall fluctuations in coastal marine ecosystems remain poorly understood. Here we evaluate the effects of rainfall intensity on the interaction between the cordgrass Spartina densiflora and Azara’s grass mouse Akodon azarae in a southwestern Atlantic salt marsh (Mar Chiquita coastal lagoon, Argentina). Field surveys showed that the abundance of A. azarae increased during rainy summers (i.e. El Niño 2005 and 2007) and had lowest values during dry summers (i.e. La Niña 2008). Salt content in sediment and plant tissue were negatively related with rainfall. In addition, field experiments showed that increased sediment salinity resulted in increased salt content in plant tissues. Elevated soil salinity also increased the proportion of senescent S. densiflora tissues and reduced plant growth. The consumption of S. densiflora leaves by A. azarae also decreased with increased soil salinity. The proportion of S. densiflora in feces collected during the driest summer was very small. Therefore, changes in the abundance of A. azarae could be mediated by plant-rodent trophic interaction or by plant cover changes. In conclusion, rainfall fluctuations changed the abiotic environment (i.e. salinity), decreasing primary production and indirectly modifying habitat use by the omnivore A. azarae and its trophic interaction with S. densiflora. The present study provides evidence that rainfall can modify ecological processes that affect the structure and dynamics of coastal marine ecosystems. KEY WORDS: Climate change · Rainfall changes · Spartina densiflora · Akodon azarae · Habitat use Full text in pdf format PreviousNextCite this article as: Pascual J, Canepuccia AD, Alberti J, Daleo P, Iribarne O (2015) Rainfall intensity modulates the interaction between the marsh cordgrass Spartina densiflora and the mouse Akodon azarae. Mar Ecol Prog Ser 523:71-80. https://doi.org/10.3354/meps11119 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 523. Online publication date: March 16, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Human amniotic epithelial cells: Proliferation and apoptosis during their hepatic differentiation

Human amniotic epithelial cells: Proliferation and apoptosis during their hepatic differentiation

Research ability in Chemistry and the Tuning Latin America specific competences: a comparative study at University of Cuyo (Argentina)

Research ability can be thought of as a competence, which requires other abilities — both generic and specific — to be successfully developed. In this study, we determine the degree of importance that the 21 specific competences (SCs) established in the Tuning Latin America (Tuning-LA) Project, have in the acquisition of research ability in Chemistry, as a result of taking the degree program offered at the Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (FCENUNCUYO, Mendoza, Argentina). To this end, we adopted the SCs proposed as learning objectives in undergraduate studies in Chemistry, and consulted academics and students at FCEN-UNCUYO about (1) the importance of these competences in his/ her opinion for work in the profession; (2) the level of achievement of these competences, that they estimated was reached as a result of taking the FCEN-UNCUYO degree program in Chemistry; and, (3) the relevance of the Tuning-AL specific competences for the development of research ability in Chemistry. The results of the survey at FCEN-UNCUYO are compared with those obtained by consulting academics and students in the framework of the Tuning-LA Project. Detailed comparisons between the opinion of academics and students at FCEN– UNCUYO are also reported.

Argentinopanorpa miguezi gen. et sp. nov.: first record of Triassic Mecoptera (Permochoristidae) from the Cuyo Basin (Mendoza, Argentina)

Lara, M.B., Bashkuev, A. & Wang, B., 1.10.2014. Argentinopanorpa miguezi gen. et sp. nov.: first record of Triassic Mecoptera (Permochoristidae) from the Cuyo Basin (Mendoza, Argentina). Alcheringa 39, 000‒000. ISSN 0311 5518A new genus and species of Permochoristidae, Argentinopanorpa miguezi, is described based on a complete forewing from the Upper Triassic Potrerillos Formation (Mendoza Province, Argentina). The new taxon is placed in the subfamily Agetopanorpinae and distinguished from other genera by the following combination of characters: Rs+MA with six branches, MP with eight branches (MP1 and MP3 with additional forks), CuA and MP fused basally for a short distance. This is the first record of Permochoristidae in the Triassic of South America and the first formal description of Mecoptera from the Cuyo Basin. Previously reported taxa attributed to Mecoptera from the Triassic of South America are briefly discussed with notes on their systematic position.María Belén Lara (corresponding author)[lara.maria.belen@live.com.ar], Area Entomología (Facultad de Ciencias Exactas y Naturales y Agrimensura-Universidad Nacional del Nordeste) and Area Paleontología (Centro de Ecología Aplicada del Litoral-Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del Nordeste), Casilla de Correo 128, 3400 Corrientes, Argentina; Alexei Bashkuev [fossilmec@gmail.com], Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997 Russia; Bo Wang [savantwang@gmail.com], Steinmann Institute, University of Bonn, 53115 Bonn, Germany and State Key Laboratory of Palaeobiology and Stratigraphy; Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China. Received 4.7.2014; revised 19.8.2014; accepted 7.9.2014.

Lista comentada de los reptiles de la Colección Zoológica de la Facultad de Ciencias Exactas y Naturales de Asunción, Paraguay

The Paraguayan reptile fauna is one of the less known in South America. The Coleccion Zoo logica of the Facultad de Ciencias Exactas y Naturales (CZCEN) contains unpublished records of Paraguay, that is why we made an annotated checklist of the material from the collection, discussing the distribution of the species and new records in Paraguay. The CZCEN preserves 137 specimens belonging to two species of turtles, four species of amphisbaenids, sixteen species of lizards and forty species of snakes.

Muricid boreholes in Pleistocene acorn barnacles from the Beagle Channel: trophic interactions during the Last Interglacial in southern South America

Gordillo, S., 2013. Muricid boreholes in Pleistocene acorn barnacles from the Beagle Channel: trophic interactions during the Last Interglacial in southern South America. Alcheringa 37, 1–8. ISSN 0311-5518.Acorn barnacles with boreholes were recovered from a Pleistocene marine deposit on Navarino Island, on the southern coast of the Beagle Channel. Balanomorph shells were identified as Balanus laevis (Bruguière, 1789), and a few bear small round holes located generally on the middle or apical part of the parietal plates, thus suggesting that they represent the work of small muricid predators. If so, this study is the first record of drilling predation on fossil barnacles reported in southern South America.[Sandra Gordillo [sgordillo@cicterra-conicet.gov.ar], Centro de Investigaciones en Ciencias de la Tierra, Consejo Nacional de Investigaciones Científicas y Técnicas (CICTERRA, CONICET-UNC); Centro de Investigaciones Paleobiológicas (CIPAL), Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Vélez Sársfield 1611 X5016GCA Córdoba, Argentina. Received 8.1.2013; revised 26.3.2013; accepted 2.4.2013