A new species of Comahuesuchus Bonaparte, 1991 (Crocodyliformes: Notosuchia) from the Upper Cretaceous of Neuquén, Lake Barreales, Patagonia, Argentina.

Notosuchian crocodyliforms were major components of the South American Cretaceous biota and, for over 125 years, paleontological fieldwork in this continent recovered several well-preserved fossils of these animals. They are largely recognized for terrestrial life and specialized feeding habits, frequently presenting bizarre taxa such as Comahuesuchus. A new species, Comahuesuchus bonapartei n. sp. (MUCPv 597; cast MN), is described from geological strata of Sierra Barrosa Formation (Upper Turonian) and Portezuelo Formation (Lower Coniacian) of Lake Barreales, Patagonia, Argentina. The new fossil comprises a right dentary bone that shares important and unique anatomical features with specimens of Comahuesuchus brachybuccalis, such as the presence of a well-marked shelf on the lateral surface of the bone; a flat, low, and wide mandibular symphysis; an enlarged, labiolingually compressed caniniform tooth at caudal position in the dentary; the presence of serrated mesial and distal carinae in the caniniform with a faceted labial surface, and the absence or extremely reduction in number of the postcaniniform dentition. C. bonapartei differs from C. brachybuccalis in having individual dentary alveoli, rather a dentition set in groove. Phylogenetic analyses support a sister-relationship between both species, which are well nested within notosuchians.

Reconstruction of the pectoral girdle and forelimb musculature of Megaraptora (Dinosauria: Theropoda).

Megaraptora is a group of enigmatic, carnivorous non-avian theropod dinosaurs from the Cretaceous of Asia, Australia, and especially South America. Perhaps the most striking aspect of megaraptoran morphology is the large, robustly constructed forelimb that, in derived members of the clade, terminates in a greatly enlarged manus with hypertrophied, raptorial unguals on the medialmost two digits and a substantially smaller ungual on digit III. The unique forelimb anatomy of megaraptorans was presumably associated with distinctive functional specializations; nevertheless, its paleobiological significance has not been extensively explored. Here we draw from observations of the pectoral girdle and forelimb skeletons of Megaraptora and myological assessments of other archosaurian taxa to provide a comprehensive reconstruction of the musculature of this anatomical region in these singular theropods. Many muscle attachment sites on megaraptoran forelimb bones are remarkably well developed, which in turn suggests that the muscles themselves were functionally significant and important to the paleobiology of these theropods. Furthermore, many of these attachments became increasingly pronounced through megaraptoran evolutionary history, being substantially better developed in derived taxa such as Australovenator wintonensis and especially Megaraptor namunhuaiquii than in early branching forms such as Fukuiraptor kitadaniensis. When considered alongside previous range of motion hypotheses for Australovenator, our results indicate that megaraptorans possessed a morphologically and functionally specialized forelimb that was capable of complex movements. Notable among these were extensive extension and flexion, particularly in the highly derived manus, as well as enhanced humeral protraction, attributes that very probably aided in prey capture.

MYC dosage compensation is mediated by miRNA-transcription factor interactions in aneuploid cancer.

We hypothesize that dosage compensation of critical genes arises from systems-level properties for cancer cells to withstand the negative effects of aneuploidy. We identified several candidate genes in cancer multiomics data and developed a biocomputational platform to construct a mathematical model of their interaction network with micro-RNAs and transcription factors, where the property of dosage compensation emerged for MYC and was dependent on the kinetic parameters of its feedback interactions with three micro-RNAs. These circuits were experimentally validated using a genetic tug-of-war technique to overexpress an exogenous MYC, leading to overexpression of the three microRNAs involved and downregulation of endogenous MYC. In addition, MYC overexpression or inhibition of its compensating miRNAs led to dosage-dependent cytotoxicity in MYC-amplified colon cancer cells. Finally, we identified negative correlation of MYC dosage compensation with patient survival in TCGA breast cancer patients, highlighting the potential of this mechanism to prevent aneuploid cancer progression.

Re-description of the braincase of the rebbachisaurid sauropod Limaysaurus tessonei and novel endocranial information based on CT scans.

CT scans of the type braincase of Limaysaurus tessonei (MUCPv-205) allowed the first study of the endocranial cavities (brain and inner ear) for this South American taxon. Comparisons of the cranial endocast of L. tessonei with other sauropods indicate that 1) South American rebbachisaurids are more similar to each other than to Nigersaurus, and 2) certain association of traits are present in all known rebbachisaurid cranial endocasts, such as lack of an enlarged dorsal expansion, poorly laterally projected cerebral hemispheres, presence of a small flocculus of the cerebellum, markedly long passage for the facial nerve (CN VII), markedly inclined pituitary, and presence of a passage for the basilar artery communicating the floor of the endocranial cavity and the pituitary fossa. The relatively enlarged olfactory region indicates that smell was an important sense for this group of dinosaurs, suggesting different olfactory capabilities when compared to coeval titanosaurs.

The activation of D2 and D3 receptor subtypes inhibits pathways mediating primary afferent depolarization (PAD) in the mouse spinal cord.

Somatosensory information can be modulated at the spinal cord level by primary afferent depolarization (PAD), known to produce presynaptic inhibition (PSI) by decreasing neurotransmitter release through the activation of presynaptic ionotropic receptors. Descending monoaminergic systems also modulate somatosensory processing. We investigated the role of D1-like and D2-like receptors on pathways mediating PAD in the hemisected spinal cord of neonatal mice. We recorded low-threshold evoked dorsal root potentials (DRPs) and population monosynaptic responses as extracellular field potentials (EFPs). We used a paired-pulse conditioning-test protocol to assess homosynaptic and heterosynaptic depression of evoked EFPs to discriminate between dopaminergic effects on afferent synaptic efficacy and/or on pathways mediating PAD, respectively. DA (10 µM) depressed low-threshold evoked DRPs by 43 %, with no effect on EFPs. These depressant effects on DRPs were mimicked by the D2-like receptor agonist quinpirole (35 %). Moreover, by using selective antagonists at D2-like receptors (encompassing the D2, D3, and D4 subtypes), we found that the D2 and D3 receptor subtypes participate in the quinpirole depressant inhibitory effects of pathways mediating PAD.

Activation of α-adrenoceptors depresses synaptic transmission of myelinated afferents and inhibits pathways mediating primary afferent depolarization (PAD) in the in vitro mouse spinal cord.

Somatosensory afferent transmission strength is controlled by several presynaptic mechanisms that reduce transmitter release at the spinal cord level. We focused this investigation on the role of α-adrenoceptors in modulating sensory transmission in low-threshold myelinated afferents and in pathways mediating primary afferent depolarization (PAD) of neonatal mouse spinal cord. We hypothesized that the activation of α-adrenoceptors depresses low threshold-evoked synaptic transmission and inhibits pathways mediating PAD. Extracellular field potentials (EFPs) recorded in the deep dorsal horn assessed adrenergic modulation of population monosynaptic transmission, while dorsal root potentials (DRPs) recorded at root entry zone assessed adrenergic modulation of PAD. We found that noradrenaline (NA) and the α1-adrenoceptor agonists phenylephrine and cirazoline depressed synaptic transmission (by 15, 14 and 22%, respectively). DRPs were also depressed by NA, phenylephrine and cirazoline (by 62, 30, and 64%, respectively), and by the α2-adrenoceptor agonist clonidine, although to a lower extent (20%). We conclude that NA depresses monosynaptic transmission of myelinated afferents onto deep dorsal horn neurons via α1-adrenoceptors and inhibits interneuronal pathways mediating PAD through the activation of α1- and α2-adrenoceptors. The functional significance of these modulatory actions in shaping cutaneous and muscle sensory information during motor behaviors requires further study.

Baalsaurus mansillai gen. et sp. nov. a new titanosaurian sauropod (Late Cretaceous) from Neuquén, Patagonia, Argentina.

We describe a dentary of a new titanosaur sauropod, Baalsaurus mansillai, gen. et sp. nov. from the Late Cretaceous of Patagonia, Argentina. The material comes from the Portezuelo Formation, Neuquén Group. Titanosaur sauropods lower jaws are scarce and only nine taxa with dentaries have been described. There are two types of morphology in titanosaur dentaries; "L" shaped or "U" shaped based on the shape, without a phylogenetic issue. In this paper; we recognize a new taxa, Baalsaurus mansillai, represented by an "L" shaped dentary with three apomorphic characters that are not present in other taxa: dentary alveoli with 10 teeth in the anterior ramus, a ventrally and anteriorly inclined symphysis and a wide ventral Meckelian groove surrounded by a thin lamina that forms a keel on the ventral border of the dentary.

Caracterización de flavonoides en el extracto alcohólico de hojas de Apium graveolens var. Rapaceum, DC / Characterization of flavonoids in alcohol extract of leaves of Apium graveolens var. Rapaceum DC

Objetivo. Caracterizar flavonoides presentes en el extracto y subextracto metanólico de las hojas de Apium graveolens var. Rapaceum, DC. "Apio-nabo". Materiales y métodos. Se elaboró un extracto y subextracto metanólico de las hojas Apium graveolens var. Rapaceum, DC. "Apio-nabo". Se determinó la solubilidad del extracto metanólico en solventes de polaridad creciente. Se detectaron los componentes químicos del extracto y subextracto metanólico mediante un tamizaje fitoquímico empleando gelatina, tricloruro férrico, reactivo de Shinoda, reactivo de Dragendorff y reactivo de Ninhidrina, entre otros. Se ejecutó cromatografía en capa fina y mediante espectroscopia UV/Vis se propuso estructuras químicas para los metabolitos tipo flavonoides presentes en el extracto y subextracto metanólico de hojas de Apium graveolens var. Rapaceum, DC. "Apio-nabo". Resultados. El extracto metanólico de hojas de Apium graveolens var. Rapaceum, DC fue soluble en solventes polares. Los metabolitos secundarios encontrados son compuestos fenólicos tipo flavonoides, taninos y alcaloides en el extracto y subextracto metanólico. Se propuso tres estructuras químicas de flavonoides a través del análisis de los espectros UV/Vis, y mediante comparación con lo publicado por TJ Mabry y Olga Lock. Conclusión. Se caracterizó la posible estructura química de tres metabolitos secundarios tipo flavona encontrados en el subextracto metanólico de hojas de Apium graveolens var. Rapaceum, DC.

Objective. To characterize flavonoids present in the methanol extract and subextract of the leaves of Apium graveolens var. Rapaceum, DC. "Celery-turnip". Materials and methods. An methanolic extract and subextract of Apium graveolens var. Rapaceum, DC. "Celery-turnip" was prepared. The solubility of the methanolic extract in solvents of increasing polarity was determined. The chemical components of the methanolic extract and subextract were detected by means of a phytochemical screening using gelatin, ferric trichloride, Shinoda reagent, Dragendorff reagent and Ninhydrin reagent, among others. Thin layer chromatography was carried out and by means of UV / Vis spectroscopy chemical structures were proposed for the flavonoid metabolites present in the methanolic extract and subextract of Apium graveolens var. Rapaceum, DC. "Celery-turnip". Results. It was determined that the methanolic extract of the leaves of Apium graveolens var. Rapaceum, DC. is soluble in polar solvents. The metabolites, the phenolic compounds, the flavonoids, the tannins and the alkaloids in the extract and methanol subextract. Flavonoid chemical structures are proposed through the analysis of the UV / Vis spectra, and it has been published with TJ Mabry and Olga Lock. Conclusion. The possible chemical structure of three secondary flavone metabolites found in methanolic subextract of leaves of Apium graveolens var. Rapaceum, DC.

Efecto de acciones de equipos de Atención Primaria de Salud para proteger la salud mental después de desastres naturales / Effect of Primary Health Care team actions to protect mental health after natural disasters

Resumen Introducción Existe alta prevalencia de alteraciones emocionales en la población expuesta a desastres y los centros de atención primaria de salud (APS) podrían contribuir a su prevención. Objetivo Analizar asociaciones post-catástrofe entre variables de APS y variables de salud mental de la población. Método Estudio efectuado en Chile un año después de un terremoto de 8,8° Richter. Se aplicó un cuestionario de intensidad de acciones de salud mental en 16 centros APS y las escalas GHQ-12 y SF-36 para malestar psicológico y calidad de vida en una muestra basada en hogares y otra de consultantes a APS. Se efectuó un análisis de regresión lineal múltiple para las dos poblaciones y los dos instrumentos. Resultados Ninguna de las variables sobre intensidad de acciones de APS mostró relación con GHQ-12 o SF-36 en ambas muestras. Las variables asociadas significativamente a mayor puntaje en GHQ-12 y menor puntaje en SF-36 fueron sexo femenino, baja escolaridad, baja situación económica, menor apoyo social y daños producidos por el terremoto. Conclusión El equipo APS podría lograr un mayor efecto preventivo post-catástrofe trabajando con otros sectores que incluyan la dimensión salud mental en el abordaje de los problemas sociales críticos en situaciones de desastres, y reservando el trabajo preventivo directo para las personas con alta vulnerabilidad psicológica.

Abstract Background There is a high prevalence of emotional disturbances in the population exposed to disasters, and primary health care centers (PHC) could contribute to their prevention. Objective To analyze post-catastrophe associations between PHC variables and population mental health variables. Method Study conducted in Chile one year after an 8.8° Richter earthquake. We applied a questionnaire on the intensity of mental health actions in 16 PHC centers, and scales GHQ-12 and SF-36 for psychological distress and quality of life, in a sample based on households and consultants of the PHCs. We used multiple linear regression analysis for the two samples and the two instruments. Results The variables on PHC intensity of actions showed no association with the GHQ-12 or SF-36 scores in both samples. The main variables significantly associated with higher scores on GHQ-12 and lower scores on SF-36 were female gender, fewer years of schooling, negative economic situation, less social support and physical damages caused by the earthquake. Conclusion The PHC teams could achieve greater preventive post-disaster outcome working with other sectors, including mental health dimensions, while addressing the critical disaster social issues, and focusing direct preventive work on those psychologically vulnerable.

New azhdarchoid pterosaur (Pterosauria, Pterodactyloidea) with an unusual lower jaw from the Portezuelo Formation (Upper Cretaceous), Neuquén Group, Patagonia, Argentina.

A new azhdarchoid pterosaur from the Upper Cretaceous of Patagonia is described. The material consists of an incomplete edentulous lower jaw that was collected from the upper portion of the Portezuelo Formation (Turonian-Early Coniacian) at the Futalognko site, northwest of Neuquén city, Argentina. The overall morphology of Argentinadraco barrealensis gen. et sp. nov. indicates that it belongs to the Azhdarchoidea and probable represents an azhdarchid species. The occlusal surface of the anterior portion is laterally compressed and shows blunt lateral margins with a medial sulcus that are followed by two well-developed mandibular ridges, which in turn are bordered laterally by a sulcus. The posterior end of the symphysis is deeper than in any other azhdarchoid. This unique construction of the lower jaw suggests the existence of an elaborate interlocking mechanism with the upper jaw. Furthermore, although speculative, it is advocated here that Argentinadraco barrealensis might have used the lower jaw to obtain its prey by cutting or ploughing through unconsolidated sediment in shallow waters, a feeding behavior not previously proposed for pterosaurs.

New azhdarchoid pterosaur (Pterosauria, Pterodactyloidea) with an unusual lower jaw from the Portezuelo Formation (Upper Cretaceous), Neuquén Group, Patagonia, Argentina

ABSTRACT A new azhdarchoid pterosaur from the Upper Cretaceous of Patagonia is described. The material consists of an incomplete edentulous lower jaw that was collected from the upper portion of the Portezuelo Formation (Turonian-Early Coniacian) at the Futalognko site, northwest of Neuquén city, Argentina. The overall morphology of Argentinadraco barrealensis gen. et sp. nov. indicates that it belongs to the Azhdarchoidea and probable represents an azhdarchid species. The occlusal surface of the anterior portion is laterally compressed and shows blunt lateral margins with a medial sulcus that are followed by two well-developed mandibular ridges, which in turn are bordered laterally by a sulcus. The posterior end of the symphysis is deeper than in any other azhdarchoid. This unique construction of the lower jaw suggests the existence of an elaborate interlocking mechanism with the upper jaw. Furthermore, although speculative, it is advocated here that Argentinadraco barrealensis might have used the lower jaw to obtain its prey by cutting or ploughing through unconsolidated sediment in shallow waters, a feeding behavior not previously proposed for pterosaurs.

A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot.

Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus--seemingly adapted for bearing extraordinary weight--and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.

A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous of Patagônia, Argentina.

Here we report on a new small deinonychosaurian theropod, Pamparaptor micros gen. et sp. nov., from the Late Cretaceous of Patagônia, Argentina. Pamparaptor micros exhibits a pedal structure previously unknown among South Américan deinonychosaurians. The new material provides new evidence about the morphology and taxonomic diversity of Patagônian deinonychosaurs. Pamparaptor is the smaller non-avialae Patagônian deinonychosaur, probably with about 0.50-0.70 meters, long. The pedal construction resembles, that of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we considered Pamparaptor a peculiar Patagônian Dromaeosaurid with troodontid-like pes.

A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous of Patagônia, Argentina

Here we report on a new small deinonychosaurian theropod, Pamparaptor micros gen. et sp. nov., from the Late Cretaceous of Patagônia, Argentina. Pamparaptor micros exhibits a pedal structure previously unknown among South Américan deinonychosaurians. The new material provides new evidence about the morphology and taxonomic diversity of Patagônian deinonychosaurs. Pamparaptor is the smaller non-avialae Patagônian deinonychosaur, probably with about 0.50-0.70 meters, long. The pedal construction resembles, that of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we considered Pamparaptor a peculiar Patagônian Dromaeosaurid with troodontid-like pes.

Aqui reportamos um novo pequeno teropodo deinonicosauriano, Pamparaptor micros gen. et sp. nov. do Cretacéo Superior da Patagônia, Argentina. Pamparaptor exibe uma estrutura pedal previamente desconhecida entre os deinonicosaurídeos da América do Sul. O novo material fornece uma nova evidencia sobre a diversidade morfológica e taxonômica dos deinonicosaurídeos patagonicos. O Paparaptor e o menor deinonicosaurídeo não-aviano patagonico, medindo provavelmente entre 0,50-0,70 metros de comprimento. A construção pedal lembra aquela de Troodontídeos ou Dromaeosaurídios basais. Entretanto, ate agora, consideramos Paparaptor um Dromaeosaurídeo patagonico peculiar com o pe similar ao de Troodontídeos.

Temperature influence on post-prandial metabolic rate of sub-Antarctic teleost fish.

The influence of temperature on the aerobic metabolism and the energetic cost of food intake (Specific Dynamic Action; SDA) have been investigated in four species of Sub-Antarctic teleosts. The species were the notothenioids Paranotothenia magellanica, Patagonotothen sima and Harpagifer bispinis and the zoarcid Austrolycus depressiceps. Individuals were captured in the vicinity of Ushuaia Bay. Experimental temperatures were 10, 4 and 2 degrees C, which correspond to summer, winter and extreme winter respectively. Individual respirometry chambers and calorimetric techniques were used. Different food items were provided: crustaceans (isopods and amphipods) and Argentinean hake muscle. Interspecific analysis was done on species fed with isopods. A rapid increase in oxygen consumption was registered after meals, indicating a typical SDA response. The Duration of the SDA was longer at low temperatures. The extra energy spent during the process itself, and when expressed as a percentage of consumed food energy, decreased with decreasing temperature. The SDA Coefficient was higher for H. bispinis that were fed with isopods. We suggest that decreases in temperature diminish the metabolic cost and extend SDA. Energy-saving mechanisms could be an evolutionary advantage to minimize the energetic cost of living at low sub-Antarctic temperatures. A general model of exponential decay is suggested for the duration of SDA and Temperature, based on the present study and compiled from literature data.

A bizarre Cretaceous theropod dinosaur from Patagonia and the evolution of Gondwanan dromaeosaurids.

Fossils of a predatory dinosaur provide novel information about the evolution of unenlagiines, a poorly known group of dromaeosaurid theropods from Gondwana. The new dinosaur is the largest dromaeosaurid yet discovered in the Southern Hemisphere and depicts bizarre cranial and postcranial features. Its long and low snout bears numerous, small-sized conical teeth, a condition resembling spinosaurid theropods. Its short forearms depart from the characteristically long-armed condition of all dromaeosaurids and their close avian relatives. The new discovery amplifies the range of morphological disparity among unenlagiines, demonstrating that by the end of the Cretaceous this clade included large, short-armed forms alongside crow-sized, long-armed, possibly flying representatives. The new dinosaur is the youngest record of dromaeosaurids from Gondwana and represents a previously unrecognized lineage of large predators in Late Cretaceous dinosaur faunas mainly dominated by abelisaurid theropods.

Fish muscle: the exceptional case of Notothenioids.

Fish skeletal muscle is an excellent model for studying muscle structure and function, since it has a very well-structured arrangement with different fiber types segregated in the axial and pectoral fin muscles. The morphological and physiological characteristics of the different muscle fiber types have been studied in several teleost species. In fish muscle, fiber number and size varies with the species considered, limiting fish maximum final length due to constraints in metabolites and oxygen diffusion. In this work, we analyze some special characteristics of the skeletal muscle of the suborder Notothenioidei. They experienced an impressive radiation inside Antarctic waters, a stable and cold environment that could account for some of their special characteristics. The number of muscle fibers is very low, 12,700-164,000, in comparison to 550,000-1,200,000 in Salmo salar of similar sizes. The size of the fibers is very large, reaching 600 microm in diameter, while for example Salmo salar of similar sizes have fibers of 220 microm maximum diameter. Evolutionary adjustment in cell cycle length for working at low temperature has been shown in Harpagifer antarcticus (111 h at 0 degrees C), when compared to the closely related sub-Antarctic species Harpagifer bispinis (150 h at 5 degrees C). Maximum muscle fiber number decreases towards the more derived notothenioids, a trend that is more related to phylogeny than to geographical distribution (and hence water temperature), with values as low as 3,600 in Harpagifer bispinis. Mitochondria volume density in slow muscles of notothenioids is very high (reaching 0.56) and since maximal rates of substrate oxidation by mitochondria is not enhanced, at least in demersal notothenioids, volume density is the only means of overcoming thermal constraints on oxidative capacity. In brief, some characteristics of the muscles of notothenioids have an apparent phylogenetic component while others seem to be adaptations to low temperature.

Mielolipoma, una lesión quirúrgica poco frecuente de la glándula adrenal / Myelolipoma, an infrequent surgical lesion of the adrenal gland

El mielolipoma es un tumor benigno poco frecuente, compuesto de tejido adiposo maduro y elementos hematopoyéticos diversos, histológicamente similares a la médula ósea normal. Estos tumores se pueden localizar comúnmente en las glándulas adrenales, pero también en sitios extra adrenales. Puede encontrarse como tumor único o múltiple, y es hormonalmente inactivo. El origen del mielolipoma es desconocido y se han propuesto varias teorías. Los mielolipomas muestran una gran variedad de manifestaciones clínicas, tales como: sangrado digestivo, hematuria, dolor abdominal en los flancos, masa abdominal y pérdida de peso, entre otras. La incidencia de estos tumores en autopsias es del 0.08 al 0.2 por ciento, gracias al US, la TAC y la RM, su hallazgo es más frecuente hoy. El diagnóstico es generalmente por exclusión, habiéndose descartado otras entidades suprarrenales. Entre los métodos diagnósticos figuran: la TAC, el US y la RM. La resección quirúrgica es el tratamiento de elección, cuando haya sintomatología; de lo contrario, un manejo conservador con controles periódicos del paciente será más que suficiente. Se presenta el caso de una paciente de 55 años, hipertensa, obesa y con un trastorno depresivo-ansioso, quién consultó por dolor abdominal, náuseas y vómitos.

Método alternativo para obtener y transportar bloques de tejido para microscopía / An alternative method to freeze and transport biological tissue blocks for microscopy

Se describe un método simple y económico para congelar material biológico destinado a la obtención de cortes histológicos en crióstato. Se propone la utilización de CO2 para producir una mezcla refrigerante en reemplazo del nitrógeno líquido como criogénico. Esta mezcla (compuesta por hielo seco y acetona) enfría el isopentano utilizado como medio de congelación hasta -76ºC y lo mantiene por ~1,5h permitiendo la congelación de más de 20 bloques de tejido. La calidad de las secciones obtenidas en crióstato es similar a aquellas obtenidas mediante la utilización de nitrógeno líquido. Este método resulta especialmente práctico durante los muestreos a bordo de embarcaciones y/o en sitios alejados de los centros urbanos.

A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur.

A unique site at the northern area of Patagonia (Neuquén, Argentina) reveals a terrestrial ecosystem preserved in a detail never reported before in a Late Cretaceous deposit. An extraordinary diversity and abundance of fossils was found concentrated in a 0.5 m horizon in the same quarry, including a new titanosaur sauropod, Futalognkosaurus dukei n.gen., n.sp, which is the most complete giant dinosaur known so far. Several plant leaves, showing a predominance of angiosperms over gymnosperms that likely constituted the diet of F. dukei were found too. Other dinosaurs (sauropods, theropods, ornithopods), crocodylomorphs, pterosaurs, and fishes were also discovered, allowing a partial reconstruction of this Gondwanan continental ecosystem.