Involvement of septal Cdk5 in the emergence of excessive anxiety induced by stress Bignante, Elena Anahi; Rodriguez Manzanares, Pablo Andrés; Mlewski, Estela Cecilia; Bertotto, Maria Eugenia; Bussolino, Daniela Fernanda; Paglini, Maria Gabriela; Molina, Víctor Alejandro The aim of the present study was to evaluate whether the activation of Cdk5, a protein that has been suggested to participate in higher cognitive functions, is required for the onset of a sensitized anxiety-related behavior induced by stress. The exposure to restraint enhanced both Cdk5 expression in certain subareas of the septohippocampal system, principally in the lateral septum (LS) and septal Cdk5 kinase activity in rats. Behaviorally, restrained wild type mice showed a behavior indicative of enhanced anxiety in the elevated plus maze (EPM). In contrast, unstressed mice and stressed knockout mice, which lacked the p35 protein, the natural activator of Cdk5, displayed similar anxiety-like behavior in the EPM. Finally, the intra-LS infusion of olomoucine - a Cdk5 inhibitor - blocked the enhanced anxiety in the EPM induced by prior stress in rats. All these data provide evidence that septal Cdk5 is required in the emergence of a sensitized emotional process induced by stress. © 2008 Elsevier B.V. and ECNP.

Multiple spawning and length of embryonic development of Munida gregaria in northern Patagonia (Argentina) Dellatorre, Fernando Gaspar; Baron, Pedro Jose Munida gregaria is a small galatheid widely distributed around the southern hemisphere, considered a key species in food webs of coastal and shelf marine ecosystems. Previous studies conducted at 55°S and 46°S on the Atlantic coast of South America, have shown that the species can adapt its reproductive patterns to different environmental conditions. The objectives of this work are to complete this analysis by determining: (1) the reproductive season span; (2) the potential of the species to produce multiple clutches of eggs; (3) the length of its embryonic development; and (4) based on previous objectives, the potential number of clutches produced by M. gregaria by reproductive season in the northern range of its coastal distribution (42-43°S, northern Patagonia). In this region, brooding females were present from June to December, representing more than 80% of total females between July and October. Females presented previtellogenic oocytes beginning maturation just after egg extrusion, and fully developed vitellogenic oocytes just before hatching. From November to February increasing proportions of females showed signs of athresia and resorption of mature oocytes. The complete embryonic development of M. gregaria lasted 26-29 days at 11°C constant temperature. Considering the pattern of synchronous ovary re-maturation and embryonic development, the length of embryogenesis at water temperatures typical from costal waters off northern Patagonia during the breeding season, it is concluded that female M. gregaria have the potential to consecutively lay more than three egg clutches per reproductive season. Copyright © Marine Biological Association of the United Kingdom 2008.

Discriminación hacia diferentes grupos en la Argentina: Gitanos Schencman, Pablo Informe sobre las vejaciones, y hechos discriminatorios, padecidas por la comunidad gitana de Argentina durante el año 2007. El capítulo se confeccionó a partir de fuentes secundarias y trabajo con los datos de la primera encuesta de opinión realizada solo entre alumnos de diversas escuelas de nivel medio.

Reversal of antiprogestin resistance and progesterone receptor isoform ratio in acquired resistant mammary carcinomas Wargon, Victoria; Helguero, Luisa; Bolado, Julieta; Rojas, Paola Andrea; Novaro, Virginia; Molinolo, Alfredo; Lanari, Claudia Lee Malvina To explore mechanisms related to hormone resistance, three resistant variants of the MPA mouse breast cancer tumor model with low levels of progesterone receptor (PR) isoform A (PR-A)/high PR-B expression were developed by prolonged selective pressure with antiprogestins. The resistant phenotype of one tumor line was reversed spontaneously after several consecutive passages in syngeneic BALB/c mice or by 17-beta-estradiol or tamoxifen treatment, and this reversion was significantly associated with an increase in PR-A expression. The responsive parental tumors disclosed low activation of ERK and high activation of AKT; resistant tumors on the other hand, showed the opposite, and this was associated with a higher metastatic potential, that did not revert. This study shows for the first time in vivo a relationship between PR isoform expression and antiprogestin responsiveness, demonstrating that, whereas acquired resistance may be reversed, changes in kinase activation and metastatic potential are unidirectional associated with tumor progression.

An approach for identification of uncertain Wiener systems Figueroa, Jose Luis; Biagiola, Silvina Ines; Agamennoni, Osvaldo Enrique As reported in the literature, Wiener models have arisen as an appealing proposal for nonlinear process representation due to their simplicity and their property of being valid over a larger operating region than a LTI model. These models consist of a cascade connection of a linear time invariant system and a static nonlinearity. In the description of these models, there are several ways to represent the linear and the nonlinear blocks, and several approaches can be found in the literature to perform the identification process. In this article, we provide a parametric description for the Wiener system. This approach allows us to describe the uncertainty as a set of parameters. The proposed algorithm is illustrated through a pH neutralization process.

Testing of photomultiplier tubes for use in the surface detector of the Pierre Auger observatory Barnhill, D.; Suarez, Federico; Arisaka, K.; Garcia, Beatriz Elena; Gongora, J. P.; Lucero, Luis Agustin; Navarro, I.; Ohnuki, T.; Risi, A.; Tripathi, A. In the array of water Cherenkov detectors of the Pierre Auger Observatory, 4800 large photomultiplier tubes (PMTs) will be used. Before being deployed, each PMT is evaluated to check that various parameters, such as the linearity, dark noise, and gain, fall within a specified range. The large scale test system, designed and constructed for this purpose, is capable of testing multiple large PMTs simultaneously. The test system and the results of the tests for the first 3964 PMTs are presented in this paper.

Upper Oligocene-Miocene clinoforms of the foreland Austral Basin of Tierra del Fuego, Argentina: Stratigraphy, depositional sequences and architecture of the foredeep deposits Ponce, Juan Jose; Olivero, Eduardo Bernardo; Martinioni, Daniel Roberto The Upper Oligocene-Miocene deposits of the foreland Austral Basin of Tierra del Fuego represent the youngest foredeep fill, developed in front of the adjacent fold and thrust belt. They consist of superbly exposed, sub-horizontal clastic successions of more than 600 m of sedimentary thickness. The study of 11 sections by means of facies analysis and sequence stratigraphic criteria enabled the identification of five depositional sequences (SI-SV), bounded by unconformities (dI-dV) involving hiatuses of different magnitudes. The basal sequence (SI) includes two members: A, mudstone dominated, deposited by cohesive flows; and B, glauconite-rich, sandstone dominated, deposited by episodic turbidity currents. The remaining sequences (SII-SV) are composed of complex arrangements of fine conglomerates, coarse- to fine-grained sandstones, and mudstones that were deposited mainly by hyperpycnal flows. The basal unconformities of the SI to SIV involve minor hiatuses, while that of the SV is a major order unconformity. Two types of clinofom geometries are recognized in the foredeep sequences. Type a clinoforms present a wedge shaped geometry and characterize the foredeep infill during the compressional tectonic regime. Regarding this clinoform type, SI is situated closer to the orogen and shows variations in the bedding dip with development of internal unconformities. SII to SIV are situated towards the foreland and are characterized by subhorizontal conformable beds of large lateral extension. Type b clinoforms, with sigmoidal geometry, show a clear northeast progradation related to a progressive foredeep fill under tectonic quiescence. This clinoform type characterizes the deposits in SV. The recognition of hyperpycnites and different types of clinoform geometries in these sequences incorporates new concepts in reservoir prospects, which are critical for the evaluation of the petroleum system in the Austral Basin.

¿Reforzador o atenuador? "Evidentemente" como adverbio evidencial en el discurso académico escrito Estrada, Andrea Maria En este artículo, a partir de un corpus de aplicación constituido por ponencias y artículos científicos pertenecientes a ciencias exactas, ciencias sociales y ciencias humanas, me propongo identificar y describir en el marco de la semántica argumentativa las propiedades del adverbio evidencial evidentemente en discurso académico escrito. En primer lugar, a partir del análisis cuantitativo y cualitativo del corpus, compruebo que este marcador ocurre mayormente en las ciencias fácticas lo que me permite esbozar una hipótesis explicativa: efectivamente, la ocurrencia de evidentemente está relacionada con la configuración discursiva propia de cada disciplina, es decir, con los efectos de cientificidad emanados de la construcción del objeto de estudio y de la presencia del locutor como intermediario de los fenómenos descriptos. En segundo lugar, y con la intención de superar ciertas contradicciones que surgen del análisis de la bibliografía de hecho algunos estudiosos analizan evidentemente como un reforzador, mientras que otros lo consideran un evidencial de inferencia, que atenúa el grado de certeza del locutor propongo un nuevo análisis a partir de ejemplos extraídos del corpus de ciencias fácticas.

Improving the schedulability of soft real-time open dynamic systems: The inheritor is actually a debtor Santos, Rodrigo Martin; Lipari, Giuseppe; Santos, Jorge This paper presents the Clearing Fund Protocol, a three layered protocol designed to schedule soft real-time sets of precedence related tasks with shared resources. These sets are processed in an open dynamic environment. Open because new applications may enter the system at any time and dynamic because the schedulability is tested on-line as tasks request admission. Top-down, the three layers are the Clearing Fund, the Bandwidth Inheritance and two versions of the Constant Bandwidth Server algorithms. Bandwidth Inheritance applies a priority inheritance mechanism to the Constant Bandwidth Server. However, a serious drawback is its unfairness. In fact, a task executing in a server can potentially steal the bandwidth of another server without paying any penalty. The main idea of the Clearing Fund Algorithm is to keep track of processor-time debts contracted by lower priority tasks that block higher priority ones and are executed in the higher priority servers by having inherited the higher priority. The proposed algorithm reduces the undesirable effects of those priority inversions because the blocked task can finish its execution in its own server or in the server of the blocking task, whichever has the nearest deadline. If demanded, debts are paid back in that way. Inheritors are therefore debtors. Moreover, at certain instants in time, all existing debts may be waived and the servers are reset making a clear restart of the system. The Clearing Fund Protocol showed definite better performances when evaluated by simulations against Bandwidth Inheritance, the protocol it tries to improve.

Effect of translocator protein (18 kDa)-ligand binding on neurotransmitter-induced salivary secretion in rat submandibular glands Ostuni, Mariano; Tumilasci, Omar Rene; Péranzi, Gabriel; Cardoso, Estela M. del Luján; Contreras, Liliana Noemí; Arregger, Alejandro Luis; Papadopoulos, Vassilios; Lacapere, Jean Jacques Background information. TSPO (translocator protein), previously known as PBR (peripheral-type benzodiazepine receptor), is a ubiquitous 18 kDa transmembrane protein that participates in diverse cell functions. High-affinity TSPO ligands are best known for their ability to stimulate cholesterol transport in organs synthesizing steroids and bile salts, although they modulate other physiological functions, including cell proliferation, apoptosis and calcium-dependent transepithelial ion secretion. In present study, we investigated the localization and function of TSPO in salivary glands. Results. Immunohistochemical analysis of TSPO in rat salivary glands revealed that TSPO and its endogenous ligand, DBI (diazepam-binding inhibitor), were present in duct and mucous acinar cells. TSPO was localized to the mitochondria of these cells, whereas DBI was cytosolic. As expected, mitochondrial membrane preparations, which were enriched in TSPO, exhibited a high affinity for the TSPO drug ligand, 3H-labelled PK 11195, as shown by Bmax and Kd values of 10.0+− 0.5 pmol/mg and 4.0+− 1.0 nM respectively. Intravenous perfusion of PK 11195 increased the salivary flow rate that was induced by muscarinic and α-adrenergic agonists, whereas it had no effect when administered alone. Addition of PK 11195 also increased the K+, Na+, Cl− and protein content of saliva, indicating that this ligand modulated secretion by acini and duct cells. Conclusions. High-affinity ligand binding to mitochondrial TSPO modulates neurotransmitter-induced salivary secretion by duct and mucous acinar cells of rat submandibular glands.

Effect of aging on 24-hour pattern of stress hormones and leptin in rats Cano, Pilar; Cardinali, Daniel Pedro; Spinedi, Eduardo Julio; Esquifino, Ana I. This work analyzes the 24-hour changes of hypothalamic–pituitary–adrenal (HPA) axis activity and leptin release in aged rats. Three- and 22-month-old male Wistar rats were killed at 6 time intervals during a 24- hour cycle (n= 8–10 rats/group). Aging augmented plasma ACTH while it decreased plasma and adrenal gland corticosterone levels. Plasma and adrenal corticosterone levels attained high levels during all the scotophase, concomitantly with the maxima in ACTH levels, whereas in aged rats only a brief plasma corticosterone peak at the early scotophase and no time of day variations of adrenal corticosterone were observed. Aging augmented circulating leptin, with a significant interaction “age × time” in the factorial ANOVA, i.e. only in young rats time of day changes were significant, with the lowest values of leptin at the middle of the light period and higher values at night. When plasma leptin was expressed on body weight basis, the age-related differences became not significant but the daily pattern of plasma leptin found in young rats persisted. Plasma and adrenal corticosterone levels correlated significantly with plasma ACTH only in young rats. Likewise, plasma leptin correlated with plasma corticosterone only in young rats. These changes can be attributed to a disrupting effect of aging on the homeostatic mechanisms modulating HPA activity and leptin release.

Tillage effects on soil carbon balance in a semiarid agroecosystem Bono, Alfredo; Alvarez, Roberto; Buschiazzo, Daniel Eduardo; Cantet, Rodolfo Juan Carlos Tillage systems may affect soil C sequestration, with a potential impact on crop productivity or organic matter mineralization. We evaluated crop yield, C inputs to the soil, and in situ CO2-C fluxes under no-till and conventional tillage (disk tillage) during the 3- to 6-yr period from the installation of an experiment in an Entic Haplustoll of the Semiarid Pampean Region of Argentina to elucidate the mechanisms responsible for possible management-induced soil organic matter changes. Yield and biomass production were greater under no-till than disk tillage for all the crops included in the rotation (oat [Avena sativa L.] + hairy vetch [Vicia villosa Roth ssp. villosa], corn [Zea mays L.], wheat [Triticum aestivum L.], and oat). This result was attributed to the higher soil water content under no-till. Carbon inputs to the soil averaged 4 Mg C ha-1 yr-1 under no-till and 3 Mg C ha-1 yr-1 under disk tillage. Soil temperature was similar between tillage systems and CO2-C emission was about 4 Mg C ha yr-1 yr-1, with significant but small differences between treatments (-0.2 Mg C ha-1 yr-1). Carbon balance of the soil was nearly equilibrated under no-till; meanwhile, greater C losses as CO2 than inputs in crop residues were measured under conventional tillage. Organic C in the soil was 5.4 Mg ha-1 higher under no-till than the disk tillage treatment 6 yr after initiation of the experiment. Results showed that in our semi-arid environment, C sequestration occurred under no-till but not conventional tillage. The sequestration process was attributed to the effect of the tillage system on crop productivity rather than on the mineralization intensity of soil organic pools.

Methanol/air fuel cells: catalytic aspects and experimental diagnostics García, M. F.; Sieben, Juan Manuel; Pilla, A. S.; Duarte, Marta María Elena; Mayer, Carlos Enrique Methanol/air fuel cell with direct feed of methanol has received growing attention due to the possibility of using a liquid fuel of simple storing. This work comments studies on the preparation of PtRu catalysts for methanol oxidation and on the influence of different operative parameter on the performance of a lab scale fuel cell. The best conditions for PtRu catalysts preparation using metal electrodeposition techniques were found. Different carbon materials were used, such as glassy carbon, carbon paper and graphite fiber cloths and felts . The more active materials were found to be graphite felts after being preoxidized electrochemically to obtain a higher surface oxide concentration. Acceptable performance of the fuel cell was obtained working at 90 {ring operator} C and low methanol concentration, because in these conditions the potential, the transport process rates and the electrode reaction kinetics increase.

Upper Cambrian carbonate sequences of the Argentine Precordillera and the Steptoean C-Isotope positive excursion (SPICE) Sial, A. N.; Peralta, Silvio Heriberto; Ferreira, V. P.; Toselli, Alejandro Jose; Aceñolaza, Florencio Gilberto; Parada Reyes, Miguel Angel; Gaucher, C.; Alonso, Ricardo Narciso; Pimentel, Marcio Carbon and Sr-isotope profiles in Upper Cambrian platformal carbonate Formations in the Precordillera, western Argentina (Zonda, La Flecha and La Silla Formations), were constructed for three representative sections: (a) Quebrada de la Flecha, Eastern Precordillera, (b) Cerro La Silla, Central Precordillera and (c) Quebrada de La Angostura, northern part of the Central Precordillera. At Quebrada de La Angostura, upper part of the La Flecha Formation, δ13Ccarb varies continuously up-section from - 2.0 to + 5.6‰ (PDB) and records the SPICE anomaly (+ 5‰) reported for the first time in South America. The peak of this excursion is characterized by intercalated 2 m thick beds of black shale with marl and limestone that record the onset of a sea-level change. The Steptoean Zonda Formation dolomites at the Quebrada de la Flecha exhibit a total δ13C range from - 2.7 to + 0.6‰ with discrete positive anomaly about 200 m from the transition to the overlying Sunwaptan La Flecha Formation. Pronounced C-isotope anomaly (- 5.6‰) is observed in the La Flecha Formation at about 300 m below the transition to the La Silla Formation. At the Cerro La Silla section, the Zonda Formation exhibit δ13C values of ∼ - 1‰, increasing slightly at the transition to the La Flecha Formation (- 1 to 0‰). The transition of the La Flecha to the La Silla Formations is characterized by alternation of black shales and dolomitic limestone with a discrete positive C-isotope excursion, probably corresponding to the SPICE. At the Quebrada de La Flecha, 87Sr/86Sr for the Zonda Formation varies from 0.70924 to 0.70955 and for the La Flecha Formation from 0.70908 to 0.70942. At Cerro La Silla this ratio varies from 0.70914 to 0.70923 for the La Flecha Formation, and from 0.70898 to 0.70980 for the La Silla Formation. At the Quebrada de La Angostura, ratios for the La Flecha carbonates range from 0.70918 to 0.70993. The overall variation of 87Sr/86Sr is consistent with globally reported Upper Cambrian seawater values at ca. 500 Ma. The unambiguous record of SPICE in the La Flecha Formation at the Quebrada de La Angostura supports a Steptoean age for its deposition and allows precise local, regional, and global stratigraphic correlation. The pronounced negative C-isotope excursion recorded in the La Flecha Formation carbonates at the Quebrada de La Flecha is likely equivalent to that registered in Sunwaptan carbonates of North America and Australia, and might be tied to a global event, as a valuable tool in stratigraphic correlation (SNICE, acronym for Sunwaptan negative isotope carbon excursion).

An efficient biotransformation of dialkyl esters of 2-oxoglutaric acid by Rhodotorula minuta whole cells Rustoy, Eduardo Miguel; Cerrutti, Patricia; Galvagno, Miguel Angel; Baldessari, Alicia Whole cells of the yeast Rhodotorula minuta were used in the biotransformation of dialkyl esters of 2-oxoglutaric acid. Almost 100% of conversion with 97-98% of enantiomeric excess of the (S) form of 2-hydroxydiesters was obtained through an enantioselective reduction of dimethyl and diethyl 2-oxoglutarate. When longer alkoxy chain 2-oxoglutarates were used as substrates, the corresponding 4-hydroxybutyric esters were obtained, suggesting a combination process including hydrolysis, decarboxylation and reduction. The cells showed a remarkable high productivity: high conversion and enantiomeric excess were obtained at 2 g wet weight mmol-1 substrate.

A Bayesian deconvolution strategy for immunoprecipitation-based DNA methylome analysis Down, Thomas A.; Rakyan, Vardhman K.; Turner, Daniel J.; Flicek, Paul; Li, Heng; Kulesha, Eugene; Gräf, Stefan; Johnson, Nathan; Herrero, Javier; Tomazou, Eleni M.; Thorne, Natalie P.; Bäckdahl, Liselotte; Herberth, Marlis; Howe, Kevin L.; Jackson, David K.; Miretti, Marcos Mateo; Marioni, John C.; Birney, Ewan; Hubbard, Tim J. P.; Durbin, Richard; Tavaré, Simon; Beck, Stephan G. DNA methylation is an indispensible epigenetic modification required for regulating the expression of mammalian genomes. Immunoprecipitation-based methods for DNA methylome analysis are rapidly shifting the bottleneck in this field from data generation to data analysis, necessitating the development of better analytical tools. In particular, an inability to estimate absolute methylation levels remains a major analytical difficulty associated with immunoprecipitation-based DNA methylation profiling. To address this issue, we developed a cross-platform algorithm - Bayesian tool for methylation analysis (Batman) - for analyzing methylated DNA immunoprecipitation (MeDIP) profiles generated using oligonucleotide arrays (MeDIP-chip) or next-generation sequencing (MeDIP-seq). We developed the latter approach to provide a high-resolution whole-genome DNA methylation profile (DNA methylome) of a mammalian genome. Strong correlation of our data, obtained using mature human spermatozoa, with those obtained using bisulfite sequencing suggest that combining MeDIP-seq or MeDIP-chip with Batman provides a robust, quantitative and cost-effective functional genomic strategy for elucidating the function of DNA methylation. © 2008 Nature Publishing Group.

Intrinsic Kinetic Modeling with Explicit Radiation Absorption Effects of the Photocatalytic Oxidation of Cyanide with TiO2 and Silica-Supported TiO2 Suspensions Marugan, Javier; Van Grieken, Rafael; Cassano, Alberto Enrique; Alfano, Orlando Mario This study is focused on the kineticmodeling of the photocatalytic oxidation of cyanide in slurry reactors. The developed model is based on an accepted reaction mechanism and explicitly takes into account the differences in the local volumetric rate of photon absorption (LVRPA) produced by the unavoidable radiation profiles existing in the photoreactor. The model and its correspondent procedures for the evaluation of the LVRPA distribution, and the estimation of the kinetic parameters have been successfully validated with both powder TiO2 and TiO2/SiO2 photocatalysts with improved recovery properties. In both cases, the model reproduces the influence of the catalyst loading, the initial cyanide concentration, and the inlet radiation flux on the reaction rate, with errors below 5%. The kinetic parameters estimated for the model are independent of the irradiation form, as well as the reactor size and its geometrical configuration, providing the necessary information for scaling-up and designing commercial scale photoreactors.

PI3K/Akt inhibition modulates multidrug resistance and activates NF-κB in murine lymphoma cell lines García, Mariana Gabriela; Alaniz, Laura Daniela; Cordo Russo, Rosalia Ines; Alvarez, Elida Ester; Hajos, Silvia Elvira Upregulation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway has been described in some tumors related to multidrug resistance (MDR). The aim of this work was to analyze the relationship between PI3K/Akt, MDR and NF-kappaB in murine lymphoma cell lines resistant to vincristine (LBR-V160) and doxorubicin (LBR-D160) as well as in the sensitive line (LBR-). PI3K/Akt activity, analyzed by phosphatidylinositol trisphosphate production and phosphorylated Akt (p-Akt) expression, was higher in the resistant cell lines than in the sensitive one and inhibition with wortmannin or LY294002 improved apoptosis in the resistant cell lines. Vincristine but not doxorubicin increased p-Akt expression whereas co-treatment with PI3K inhibitors and vincristine increased apoptosis in the three cell lines. Wortmannin and LY294002 inhibited P-glycoprotein (Pgp) function and also increased NF-kappaB activity. We concluded that the PI3K/Akt pathway is involved in MDR in lymphoma cell lines and PI3K/Akt inhibition correlates down-regulation of NF-kappaB activity and inhibition Pgp function.

Carbon steel passivity examined in alkaline solutions: the effect of chloride and nitrite ions Valcarce, María Beatriz; Vazquez, Marcela Vivian The effect of chloride and nitrite ions on the passivity of steel in alkaline solutions was investigated. Four nitrite dosages were tested, resulting in various nitrite/chloride ratios. The behavior of steel was evaluated on electrodes aged during 1 and 90 days, measuring electrochemical parameters such as the corrosion, pitting and repassivation potentials, the corrosion current density, the weight loss and performing electrochemical impedance spectra. The presence of 0.8 mol l-1 of chloride induced pitting only under polarization and when the chloride/hydroxyl ratio was not less than one. Nitrite ions behave as effective inhibitors of pit propagation for all the concentrations tested (0.2-0.8 mol l-1). A nitrite/chloride ratio of 0.25 induces complete surface repassivation. Nevertheless, at open circuit potential, the high alkalinity guarantees passivation even in the presence of chlorides. In the event that the passive layer is damaged and pitting can be initiated, nitrite ions are effective in inhibiting pit propagation. © 2008 Elsevier Ltd. All rights reserved.

An anilioid snake from the Upper Cretaceous of northern Patagonia Gomez, Raul Orencio; Baez, Ana Maria; Rougier, Guillermo W. We report the first record of anilioids from southern South America, a region where they do not live today. The fossils come from the Allen Formation (Late Campanian Early Maastrichtian) at Bajo Trapalcó and Bajo de Santa Rosa localities, Río Negro province, Argentina. The remains consist of several vertebrae, most of which belong to the mid posterior precloacal region of the column. Comparisons to other extant and extinct anilioid taxa indicate that these remains represent a new taxon, Australophis anilioides gen. et sp. nov. Australophis is morphologically closer to Palaeocene Hoffstetterella from Brazil and extant South American Anilius than to any other snake. These taxa might be closely related, in which case they would represent a lineage distinct from that including Cylindrophis and uropeltids. The two lineages must have diverged by the Late Cretaceous.