Multiple lines of evidence show that <i>Phymaturus agilis</i> Scolaro, Ibargüengoytía & Pincheira-Donoso, 2008 is a junior synonym of <i>Phymaturus spectabilis</i> Lobo & Quinteros, 2005

Lobo and Quinteros (2005) described Phymaturus spectabilis from Río Negro Province, Argentina.The species was characterized most notably by having a brown background with amore-or-less bilaterally symmetrical pattern of bold, light tan markings, some enclosing smallbrown spots, on the head, limbs, body, and tail. In 2008, Scolaro et al. described P. agilis froma locality 22 km south of the type locality of P. spectabilis. It was reported to differ from P. spectabilis in its nearly uniform brown color and certain morphometric and meristiccharacteristics. In 2009 we collected, at the type locality of P. agilis, five adults (both sexes) with the bold pattern of P. spectabilis, and five adults (both sexes) with the uniform color ofP. agilis. Subsequently, one of the females with the P. spectabilis pattern gave birth to twoindividuals, one of which had the pattern of P. agilis, the other with the pattern of P. spectabilis.Our analyses of specimens assignable to P. agilis and P. spectabilis detected no significant differences between individuals with the two patterns for nine morphological variables(including those used to diagnose P. agilis), with overlap in the ranges of the variables forboth patterns. We therefore conclude that P. agilis is a junior synonym of P. spectabilis.En 2005 Lobo y Quinteros describieron Phymaturus spectabilis de la Provincia de Río Negro, Argentina. La especie fue caracterizada, como lo mas notable, por contar con en un fondo general castaño de un patrón más oscuro que delimita manchas castañas claras dispuestas simétricamente en la cabeza, cuerpo extremidades y cola. En el 2008, Scolaro et al. describieron Phymaturus agilis de una localidad 22 km al sur de la localidad tipo de P. spectabilis. Se indicó diferir de P. spectabilis por su casi uniforme color castaño y por ciertas características merísticas y morfométricas. En 2009 colectamos, en la localidad tipo de P. agilis, cinco adultos (ambos sexos) con el patrón manchado oscuro de P. spectabilis, y cinco adultos (ambos sexos) con el color uniforme de P. agilis. Subsecuentemente una de las hembras con el patrón de P. spectabilis dio a luz dos individuos, uno con el patrón de P. agilis, el otro con el patrón de P. spectabilis. Nosotros no encontramos diferencias significativas entre los individuos con los dos patrones para nueve variables morfológicas, exhibiendo superposición los rangos de las variables morfológicas de los patrones. Nosotros concluimos que P. agilis es un sinónimo de P. spectabilis.Asociación Herpetológica Argentina (AHA

Chemical blindness in Liolaemus lizards is counterbalanced by visual signals, the case of two species with different communication modalities

Abstract Animals employ a wide variety of communication tactics that rely on distinct sensory modalities. Lizards are characterized by their heightened dependence on chemical and visual communication. Some authors have proposed that a reduced number of chemical secretory pores may be associated with an increased visual dependence in some species. Here, we study two species of Liolaemus lizards with different chemical features to compare their visual and chemical communication. The first species, L. coeruleus, does not have precloacal pores in either sex, while L. albiceps has precloacal pores in both sexes. We expect that L. coeruleus will principally adhere to the visual modality, while L. albiceps will show greater chemical responses. We filmed the lizard's response to different chemical and visual stimuli. In the trials, both species demonstrated chemical self-recognition, L. albiceps exhibited less total time in motion but more behavioural displays in the presence of conspecific scents, suggesting conspecific chemical recognition too. On the other hand, visuals results showed that L. coeruleus reacted more to the presence of conspecifics than L. albiceps. These observations suggest that L. coeruleus relies more on visual signalization, while L. albiceps has a greater dependence on chemical communication. Our results may indicate a correspondence between precloacal secretions and the response to these by conspecifics in both species studied

Climate, geographic distribution and viviparity in Liolaemus (Reptilia; Squamata) species: when hypotheses need to be tested

La distribución de los reptiles, dada su dependencia de la temperatura, puede verse restringida en función del clima. En particular, se han planteado tres hipótesis que vinculan el clima con la distribución y el viviparismo en las especies de reptiles: i) hipótesis de clima variable, ii) hipótesis del clima frío e iii) hipótesis de manipulación materna. Entre las lagartijas de Sudamérica las especies del género Liolaemus se distribuyen tanto en ambientes cálidos como fríos y más del 50 % de ellas son vivíparas. En este trabajo estudiamos 47 especies de Liolaemus, tomando datos climáticos de sus sitios de colecta, su temperatura de preferencia (Tpref), el coeficiente de variación de la misma (CV) y los límites de tolerancia térmica (TT). Nuestros resultados no apoyan la hipótesis de clima variable, aunque ésta ha sido sustentada en estudios anteriores. Se encontró relación entre viviparismo y altitud, pero no entre viviparismo y las variables térmicas ambientales. Finalmente, las especies vivíparas de Liolaemus mostraron un comportamiento termorregulador más preciso que las especies ovíparas, reforzando la hipótesis de manipulación materna.Reptile’ distributions, under the light of their strong dependence on particular temperature requirements, may be constrained as a consequence of climate. The relationship between reptile viviparity and climate yielded two previously proposed hypotheses (the cold climate and the maternal manipulation hypotheses) that together with the climatic variability hypothesis; theoretically link climate, distribution and reproductive mode. The extensive variation in mean environmental temperature associated with changes in parity strategies has received much attention in this ectothermic group. Among Southamerican lizards, Liolaemus are distributed in cold and warm regions and more than 50 % of described species are viviparous. We studied 47 Liolaemus species considering climatic data where collected, preferred body temperature, its coefficient of variation and their thermal tolerance. Our results do not support the climate variability hypothesis, previously supported in other studies. We found a relationship between viviparity and elevation, but not between viviparity and thermal climatic variables. Finally, viviparous Liolaemus species showed more precise thermoregulatory behavior than oviparous ones, supporting the maternal manipulation hypothesis.Agencia Nacional de Promoción Científica y Tecnológica de Argentina (PICT 06-01205) y Consejo Nacional de Investigaciones científicas y Tecnológicas (PIP 2846 y PIP 6287)

Variación diaria de la temperatura corporal en dos especies de lagartos nocturnos (Squamata: Gekkonidae: Homonota) con comentarios sobre el uso de refugios

Poco es lo que se conoce sobre la variación de la temperatura corporal de lagartos nocturnos. Se sabe que algunos lagartos nocturnos termorregulan durante el día. El tamaño corporal y el comportamiento, a su vez, pueden estar relacionados con la inercia térmica. Individuos de Homonota borelli y H. darwini fueron expuestos a tres situaciones, a) refugios cálidos (la temperatura nunca fue menor a los 34 ºC), b) refugios con una temperatura inferior a los 28-30 ºC, y c) se les permitió escoger entre cada una de las opciones anteriores. La temperatura corporal en general y el patrón diario fueron similares en ambas especies siendo más altas durante el día. Cuando los lagartos eligieron los refugios, se observaron diferencias entre las especies, H. borelli usó más los refugios con fuente de calor en tanto que H. darwini usó refugios sin fuente de calor. El tamaño corporal y la distribución geográfica podrían estar relacionados con las diferencias observadas.Very little is known about diel variation in body temperature among nocturnal lizards. Some nocturnal lizards thermoregulate during the day, and body size plus behavior may be related to the amount of thermal inertia. Lizards of the species Homonota borelli and H. darwini were either exposed to three different situations a) a heated retreat site (never below than 34ºC), b) a retreat with a temperature lower than 28-30ºC, and c) where lizards were allowed to choose between a warm or a cool retreat. Body temperatures and diel pattern were similar for both species. Body temperatures were higher during the day. When lizards choose for retreats, differences were observed, H. darwini preferred cool retreats, whereas H. borelli used the warmer ones. Body size, coloration and geographic distribution may be related to the different patterns observed.Asociación Herpetológica Argentina (AHA

Variación diaria de la temperatura corporal en dos especies de lagartos nocturnos (Squamata: Gekkonidae: Homonota) con comentarios sobre el uso de refugios

Poco es lo que se conoce sobre la variación de la temperatura corporal de lagartos nocturnos. Se sabe que algunos lagartos nocturnos termorregulan durante el día. El tamaño corporal y el comportamiento, a su vez, pueden estar relacionados con la inercia térmica. Individuos de Homonota borelli y H. darwini fueron expuestos a tres situaciones, a) refugios cálidos (la temperatura nunca fue menor a los 34 ºC), b) refugios con una temperatura inferior a los 28-30 ºC, y c) se les permitió escoger entre cada una de las opciones anteriores. La temperatura corporal en general y el patrón diario fueron similares en ambas especies siendo más altas durante el día. Cuando los lagartos eligieron los refugios, se observaron diferencias entre las especies, H. borelli usó más los refugios con fuente de calor en tanto que H. darwini usó refugios sin fuente de calor. El tamaño corporal y la distribución geográfica podrían estar relacionados con las diferencias observadas.Very little is known about diel variation in body temperature among nocturnal lizards. Some nocturnal lizards thermoregulate during the day, and body size plus behavior may be related to the amount of thermal inertia. Lizards of the species Homonota borelli and H. darwini were either exposed to three different situations a) a heated retreat site (never below than 34ºC), b) a retreat with a temperature lower than 28-30ºC, and c) where lizards were allowed to choose between a warm or a cool retreat. Body temperatures and diel pattern were similar for both species. Body temperatures were higher during the day. When lizards choose for retreats, differences were observed, H. darwini preferred cool retreats, whereas H. borelli used the warmer ones. Body size, coloration and geographic distribution may be related to the different patterns observed.Asociación Herpetológica Argentina (AHA

Strong magnetoelastic effect in CeCo1-xFexSi as Néel order is suppressed

A very strong magnetoelastic effect in the CeCo1-xFexSi alloys is reported. The strength of the magnetostrictive effect can be tuned upon changing x. The moderate low-temperature linear magnetostriction observed at low Fe concentrations becomes very large (ΔLL16T,2K=3×10-3) around the critical concentration xc≈0.23 at which the long-range antiferromagnetic order vanishes. Upon increasing doping through the nonmagnetic region (x>xc), the magnetostriction strength gradually weakens again. The interplay between magnetic order and the Kondo screening appears to cause an enhanced valence susceptibility slightly changing the Ce ions valence, ultimately triggering the large magnetostriction observed around the critical concentration. Previous studies of the evolution of the lattice parameters with x as well as magnetization and x-ray absorption spectroscopy measurements support this hypothesis.Fil: Correa, Víctor Félix. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Villagrán Asiares, Alberto Gaston. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Betancourth Giraldo, Diana Maria. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Encina, Sergio. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Pedrazzini, Pablo. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Cornaglia de la Cruz, Pablo Sebastian. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Garcia, Daniel Julio. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sereni, Julian Gustavo Renzo. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Maiorov, B.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Caroca Canales, N.. Max planck institut Fur Chemische Physik Fester Stoffe; AlemaniaFil: Geibel, C.. Max planck institut Fur Chemische Physik Fester Stoffe; Alemani

A global analysis of field body temperatures of active squamates in relation to climate and behaviour

Squamate body temperatures, their frequency distributions and their relation to environmental temperature, are globally influenced by behavioural and climatic factors. For all temperatures and climates, heliothermic species' body temperatures are consistently higher and more stable than in other species, but in re- gions with warmer climate these differences become less pronounced. A comparable variation was found in non-heliotherms, but in not nocturnal species whose body tem- peratures were similar to air and substrate irrespective of the macroclimatic context

Evaluation of the effects of erythritol on gene expression in Brucella abortus

Bacteria of the genus Brucella have the unusual capability to catabolize erythritol and this property has been associated with their virulence mainly because of the presence of erythritol in bovine foetal tissues and because the attenuated S19 vaccine strain is the only Brucella strain unable to oxydize erythritol. In this work we have analyzed the transcriptional changes produced in Brucella by erythritol by means of two high throughput approaches: RNA hybridization against a microarray containing most of Brucella ORF's constructed from the Brucella ORFeome and next generation sequencing of Brucella mRNA in an Illumina GAIIx platform. The results obtained showed the overexpression of a group of genes, many of them in a single cluster around the ery operon, able to co-ordinately mediate the transport and degradation of erythritol into three carbon atoms intermediates that will be then converted into fructose-6P (F6P) by gluconeogenesis. Other induced genes participating in the nonoxidative branch of the pentose phosphate shunt and the TCA may collaborate with the ery genes to conform an efficient degradation of sugars by this route. On the other hand, several routes of amino acid and nucleotide biosynthesis are up-regulated whilst amino acid transport and catabolism genes are down-regulated. These results corroborate previous descriptions indicating that in the presence of erythritol, this sugar was used preferentially over other compounds and provides a neat explanation of the the reported stimulation of growth induced by erythritol

Molecular Architectures of Trimeric SIV and HIV-1 Envelope Glycoproteins on Intact Viruses: Strain-Dependent Variation in Quaternary Structure

The initial step in target cell infection by human, and the closely related simian immunodeficiency viruses (HIV and SIV, respectively) occurs with the binding of trimeric envelope glycoproteins (Env), composed of heterodimers of the viral transmembrane glycoprotein (gp41) and surface glycoprotein (gp120) to target T-cells. Knowledge of the molecular structure of trimeric Env on intact viruses is important both for understanding the molecular mechanisms underlying virus-cell interactions and for the design of effective immunogen-based vaccines to combat HIV/AIDS. Previous analyses of intact HIV-1 BaL virions have already resulted in structures of trimeric Env in unliganded and CD4-liganded states at ∼20 Å resolution. Here, we show that the molecular architectures of trimeric Env from SIVmneE11S, SIVmac239 and HIV-1 R3A strains are closely comparable to that previously determined for HIV-1 BaL, with the V1 and V2 variable loops located at the apex of the spike, close to the contact zone between virus and cell. The location of the V1/V2 loops in trimeric Env was definitively confirmed by structural analysis of HIV-1 R3A virions engineered to express Env with deletion of these loops. Strikingly, in SIV CP-MAC, a CD4-independent strain, trimeric Env is in a constitutively “open” conformation with gp120 trimers splayed out in a conformation similar to that seen for HIV-1 BaL Env when it is complexed with sCD4 and the CD4i antibody 17b. Our findings suggest a structural explanation for the molecular mechanism of CD4-independent viral entry and further establish that cryo-electron tomography can be used to discover distinct, functionally relevant quaternary structures of Env displayed on intact viruses