Centro Científico Tecnológico - Nordeste

Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, Møller-Plesset, configuration-interaction, and coupled-cluster levels of theory. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients and Hessians are available for geometry optimizations, molecular dynamics, and vibrational studies, whereas magnetic resonance and optical activity can be studied in a gauge-origin-invariant manner. Frequency-dependent molecular properties can be calculated using linear, quadratic, and cubic response theory. A large number of singlet and triplet perturbation operators are available for the study of one-, two-, and three-photon processes. Environmental effects may be included using various dielectric-medium and quantum-mechanics/molecular-mechanics models. Large molecules may be studied using linear-scaling and massively parallel algorithms. Dalton is distributed at no cost from http://www.daltonprogram.org for a number of UNIX platforms.

Like many other crops, the cultivated peanut (Arachis hypogaea L.) is of hybrid origin and has a polyploid genome that contains essentially complete sets of chromosomes from two ancestral species. Here we report the genome sequence of peanut and show that after its polyploid origin, the genome has evolved through mobile-element activity, deletions and by the flow of genetic information between corresponding ancestral chromosomes (that is, homeologous recombination). Uniformity of patterns of homeologous recombination at the ends of chromosomes favors a single origin for cultivated peanut and its wild counterpart A. monticola. However, through much of the genome, homeologous recombination has created diversity. Using new polyploid hybrids made from the ancestral species, we show how this can generate phenotypic changes such as spontaneous changes in the color of the flowers. We suggest that diversity generated by these genetic mechanisms helped to favor the domestication of the polyploid A. hypogaea over other diploid Arachis species cultivated by humans.

UNLABELLED: This study was undertaken to present data from a phase 2 study in which patients with unresectable hepatocellular carcinoma (HCC) with and without portal vein thrombosis underwent radioembolization with Yttrium ((90)Y) microspheres. Patients treated were stratified by Okuda, Child-Pugh, baseline bilirubin, tumor burden, Eastern Cooperative Oncology Group (ECOG), presence of cirrhosis and portal vein thrombosis (PVT) (none, branch, and main). Clinical and biochemical data were obtained at baseline and at 4-week intervals following treatment for up to 6 months. Tumor response was obtained using computed tomography (CT). Patients were followed for survival. One hundred eight patients were treated during the study period. Thirty-seven (34%) patients had PVT, 12 (32%) of which involved the main PV. The cumulative dose for those with and without PVT was 139.7 Gy and 131.9 Gy, respectively. The partial response rate using world Health Organization (WHO) criteria was 42.2%. Using European Association for the Study of the Liver (EASL), the response rate was 70%. Kaplan-Meier survival varied depending on location of PVT and presence of cirrhosis. The adverse event (AE) rates were highest in patients with main PVT and cirrhosis. There were no cases of radiation pneumonitis. CONCLUSION: The use of minimally embolic (90)Y glass microspheres to treat patients with HCC complicated by branch/lobar PVT may be clinically indicated and appears to have a favorable toxicity profile. Further investigation is warranted in patients with main PVT.

Recent studies increasingly note the effect of captivity or the built environment on the microbiome of humans and other animals. As symbiotic microbes are essential to many aspects of biology (e.g., digestive and immune functions), it is important to understand how lifestyle differences can impact the microbiome, and, consequently, the health of hosts. Animals living in captivity experience a range of changes that may influence the gut bacteria, such as diet changes, treatments, and reduced contact with other individuals, species and variable environmental substrates that act as sources of bacterial diversity. Thus far, initial results from previous studies point to a pattern of decreased bacterial diversity in captive animals. However, these studies are relatively limited in the scope of species that have been examined. Here we present a dataset that includes paired wild and captive samples from mammalian taxa across six Orders to investigate generalizable patterns of the effects captivity on mammalian gut bacteria. In comparing the wild to the captive condition, our results indicate that alpha diversity of the gut bacteria remains consistent in some mammalian hosts (bovids, giraffes, anteaters, and aardvarks), declines in the captive condition in some hosts (canids, primates, and equids), and increases in the captive condition in one host taxon (rhinoceros). Differences in gut bacterial beta diversity between the captive and wild state were observed for most of the taxa surveyed, except the even-toed ungulates (bovids and giraffes). Additionally, beta diversity variation was also strongly influenced by host taxonomic group, diet type, and gut fermentation physiology. Bacterial taxa that demonstrated larger shifts in relative abundance between the captive and wild states included members of the Firmicutes and Bacteroidetes. Overall, the patterns that we observe will inform a range of disciplines from veterinary practice to captive breeding efforts for biological conservation. Furthermore, bacterial taxa that persist in the captive state provide unique insight into symbiotic relationships with the host.

Over the past decade several studies have reported that the gut microbiomes of mammals with similar dietary niches exhibit similar compositional and functional traits. However, these studies rely heavily on samples from captive individuals and often confound host phylogeny, gut morphology, and diet. To more explicitly test the influence of host dietary niche on the mammalian gut microbiome we use 16S rRNA gene amplicon sequencing and shotgun metagenomics to compare the gut microbiota of 18 species of wild non-human primates classified as either folivores or closely related non-folivores, evenly distributed throughout the primate order and representing a range of gut morphological specializations. While folivory results in some convergent microbial traits, collectively we show that the influence of host phylogeny on both gut microbial composition and function is much stronger than that of host dietary niche. This pattern does not result from differences in host geographic location or actual dietary intake at the time of sampling, but instead appears to result from differences in host physiology. These findings indicate that mammalian gut microbiome plasticity in response to dietary shifts over both the lifespan of an individual host and the evolutionary history of a given host species is constrained by host physiological evolution. Therefore, the gut microbiome cannot be considered separately from host physiology when describing host nutritional strategies and the emergence of host dietary niches.

Pasaron casi 100 años entre la designación por Linneo de la entonces única especie de Arachis (A. hypogaea L.) conocida por los europeos, y el primer tratamiento taxonómico del género por Bentham en 1841. Durante los siguientes 100 años, aparecieron cinco a diez descripciones de especies adicionales, que asignaban diferentes especies a los mismos nombres, y diferentes nombres a las mismas especies. A mediados del Siglo XX, era imposible examinar un ejemplar de herbario de Arachis y asignar con alguna certeza algún epíteto a algún espécimen (que no fuera un ejemplar tipo) excepto a A. hypogaea, A. guaranitica, A. tuberosa y A. villosulicarpa. En nuestro tratamiento, la literatura de este caos botánico en Arachis esta revisada en detalle y se hace un análisis de los fundamentos de su ocurrencia. Se demuestra que las bases de la confusión moran en la combinación de la naturaleza esotérica de los caracteres morfológicos diferenciados de Arachis, de los especímenes fragmentarios de antaño, y de la representación de especies por plántulas. Además, se relata cómo, en 1959, decidimos reexplorar la localidad tipo de cada especie hasta entonces conocida, y recolectar allí especímenes de las plantas enteras y así resolver el problema. Después de treinta y cinco años, dos generaciones de coleccionistas de plantas, y alrededor de 2000 colecciones, presentamos aquí las descripciones de 69 especies de Arachis, especies distribuidas en Sudamérica al este de los Andes, al sud del Amazonas, al norte de La Plata y desde el noroeste argentino hasta el nordeste de Brasil. Descubrimos muy pronto que los caracteres más significativos de Arachis residen en sus estructuras subterráneas, incluyendo sus frutos, tallos rizomatosos, sistemas radicales e hipocótilos. Demostramos que estos caracteres determinantes tienden a aglomerar las colecciones en grupos que se asocian con áreas geográficas y formaciones ecológicas generalmente diferentes. Hicimos un muestreo de 100 materiales representativos de aquellos grupos, áreas, y formaciones y los arreglamos en un experimento dialélico de cruzamientos y mostramos, en cruzamientos entre materiales de los diferentes grupos, un número notable de fracasos completos en la fertilización cruzada y, en aquellos híbridos que se lograron, se observó una alta tasa de infertilidad en la F1. Cuando se combinaron estas incompatibilidades e infertilidades de polen híbrido con los datos de agrupamiento de caracteres morfológicos, se cristalizaron entonces las nueve distintas secciones del género aquí presentadas. Las figuras impuestas sobre mapas de Sudamérica ilustran las distribuciones geográficas de estas secciones. Las colecciones, entonces, fueron asignadas a las diferentes secciones sobre la base de las incompatibilidades de cruzamiento y de los agrupamientos de caracteres exo-morfológicos. Al hacer estos grupos, las caracteristicas esotéricas a las cuales se hace referencia arriba, tan confusas cuando se aplican a través de los límites seccionales, se volvieron altamente pertinentes al ser aplicadas al problema de la diferenciación específica entre materiales dentro de las secciones. Estas características, aplicadas en conjunto con la citología cromosómica, las reacciones cromatográficas y antigénicas, las variaciones en la fertilidad híbrida intra-seccional y las adaptaciones de forma de planta, y de hábito anual o perenne, nos permitió definir los siguientes taxa del género Arachis: Sección I. TRIERECTOIDES nov.: 1. A. guaranitica, 2. A. tuberosa.Sección II. ERECTOIDES nov.: 3. A. Martii, 4. A. brevipetiolata nov., 5. A. Oteroi nov., 6. A. Hatschbachii nov., 7. A. cryptopotamica nov., 8. A. major nov., 9. A. Benthamii, 10. A. douradiana nov., 11. A. gracilis nov., 12. A. Hermannii nov., 13. A. Archeri nov., 14. A. stenophylla nov., 15a. A. paraguariensis subsp. paraguariensis, 15b. A. paraguariensis subsp. capibarensis nov. Sección III. EXTRANERVOSAE nov.: 16.A. setinervosa nov., 17. A. Macedoi nov., 18. A. marginata, 19. A. prostrata, 20. A. lutescens, 21. A retusa nov., 22. A. Burchellii nov., 23. A. Pietrarellii nov., 24. A. villosulicarpa. Sección IV. TRISEMINATAE nov.: 25. A. triseminata nov. Sección V.HETERANTHAE nov.: 26. A. Giacomettii nov., 27. A. sylvestris, 28. A. pusilla, 29. A. Dardani nov. Sección VI. CAULORRHIZAE nov.: 30. A. repens, 31. A. Pintoi nov. Sección VII. PROCUMBENTES nov.: 32. A. lignosa nov. comb., 33. A. Kretschmeri nov., 34. A. Rigonii, 35. A. chiquitana nov., 36. A. matiensis nov., 37. A. appressipila nov., 38. A. Vallsii nov., 39. A. subcoriacea nov. Sección VIII. RHIZOMATOSAE nov., Serie PRORHIZOMATOSAE nov.: 40. A. Burkartii. Serie RHIZOMATOSAE nov.: 41.A. pseudovillosa nov. comb., 42a. A. glabrata var. glabrata, 42b. A. glabrata var.Hagenbeckii. Sección IX. ARACHIS: 43. A. glandulifera, 44. A. cruziana nov., 45. A. monticola, 46. A. magna nov., 47. A. ipaënsis nov., 48. A. valida nov., 49. A. Williamsii nov., 50. A. Batizocoi, 51. A. duranensis nov., 52. A. Hoehnei nov., 53. A. stenosperma nov., 54. A. praecox nov., 55. A. palustris nov., 56. A. benensis nov., 57. A. trinitensis nov., 58. A. decora nov., 59. A. Herzogii nov., 60. A. microsperma nov., 61. A. villosa, 62. A. helodes, 63. A. correntina nov. comb., 64. A. Simpsonii nov., 65. A. Cardenasii nov., 66. A. Kempff-Mercadoi nov., 67. A. Diogoi, 68. A. Kuhlmanii nov., 69a. A. hypogaea subsp. hypogaea var. 1. hypogaea, var. 2.hirsuta, 69b. A. hypogaea subsp. fastigiata var. 1. fastigiata, var. 2. peruviana nov., var. 3. aequatoriana nov., var. 4. vulgaris. Se demuestra cómo los sistemas reproductivos autógamos, la reproducción agamética, el hábito de fructificación subterránea y el mecanismo limitado de dispersión de semillas están lógicamente ligados con la deriva de organización cromosómica que da origen a incrementos notables de infertilidad en cruzamientos entre diferentes accesiones de la misma especie, a una infertilidad variablemente más alta en cruzamientos entre especies dentro de las secciones, hasta una casi total infertilidad entre especies de diferentes secciones. Las relaciones evolutivas y filogenéticas entre las diferentes secciones están discutidas y también demostradas en una secuencia de diagramas ilustrando las ideas presentadas. Es evidente que las distancias genéticas que separan las secciones están lejos de ser todas de la misma magnitud. Las secciones presumiblemente más antiguas (Triseminatae, Trierectoides, Erectoides, Extranervosae y Heteranthae), excepto por la secciónErectoides, están mucho más aisladas de las secciones restantes y entre sí que aquellas secciones que se consideran de origen más reciente (Procumbentes, Caulorrhizae, Rhizomatosae y Arachis). La sección Arachis es por mucho la más grande, pues contiene cerca de 40% de las especies descritas. Parece que las especies de esta sección se están expandiendo hacia nuevos territorios e invadiendo áreas ocupadas por especies de otras secciones. Crecen entremezcladas con poblaciones de Extranervosae en la cuenca alta del río Paraguay y ocupan terrenos comunes con la sección Procumbentes en el Gran Pantanal. Han llegado hasta las orillas de La Plata y a la costa sureste de Brasil, y crecen desde Yala en el noroeste de la Argentina hasta el río Tocantins en el nordeste de Brasil. Incluyen el cultígeno de importancia mundial, A. hypogaea. Esencialmente cada trabajo publicado sobre la historia botánica y la taxonomía deArachis está presentado aquí en las referencias a especímenes individuales y en la bibliografía general. La historia de A. hypogaea desde principios del Siglo XVI hasta tiempos más recientes, junto con los nombres comunes en varios idiomas autóctonos americanos, nos dan una perspectiva sobre la antigüedad de este cultivo y el nivel de civilización requerido para su creación. Seis apéndices proporcionan datos de apoyo e información de archivo. Claves diagnósticas a las secciones y a las especies dentro de cada sección seleccionan los rasgos más distintivos de las secciones y especies. Diecinueve dibujos de línea capturan las estructuras claves para distinguir las secciones y especies, incluyendo plantas enteras, sistemas radicales, orientaciones de frutos, reproducción agamética a partir de estructuras fructíferas, formas de carpelos, y la fisionomía superficial de hojas y tallos.

Most past studies of river dune dynamics have concentrated on two‐dimensional (2‐D) bed forms, with constant heights and straight crest lines transverse to the flow, and their associated turbulent flow structure. This morphological simplification imposes inherent limitations on the interpretation and understanding of dune form and flow dynamics in natural channels, where dune form is predominantly three‐dimensional. For example, studies over 2‐D forms neglect the significant influence that lateral flows and secondary circulation may have on the flow structure and thus dune morphology. This paper details a field study of a swath of 3‐D dunes in the Rio Paraná, Argentina. A large (0.35 km wide, 1.2 km long) area of dunes was surveyed using a multibeam echo sounder (MBES) that provided high‐resolution 3‐D detail of the river bed. Simultaneous with the MBES survey, 3‐D flow information was obtained with an acoustic Doppler current profiler (ADCP), revealing a complicated pattern of dune morphology and associated flow structure within the swath. Dune three‐dimensionality appears intimately connected to the morphology of the upstream dune, with changes in crest line curvature and crest line bifurcations/junctions significantly influencing the downstream dune form. Dunes with lobe or saddle‐shaped crest lines were found to have larger, more structured regions of vertical velocity with smaller separation zones than more 2‐D straight‐crested dunes. These results represent the first integrated study of 3‐D dune form and mean flow structure from the field and show several similarities to recent laboratory models of flow over 3‐D dunes.

Arachis hypogaea is a natural, well-established allotetraploid (AABB) with 2n = 40. However, researchers disagree on the diploid genome donor species and on whether peanut originated by a single or multiple events of polyploidization. Here we provide evidence on the genetic origin of peanut and on the involved wild relatives using double GISH (genomic in situ hybridization). Seven wild diploid species (2n = 20), harboring either the A or B genome, were tested. Of all genomic DNA probe combinations assayed, A. duranensis (A genome) and A. ipaensis (B genome) appeared to be the best candidates for the genome donors because they yielded the most intense and uniform hybridization pattern when tested against the corresponding chromosome subsets of A. hypogaea. A similar GISH pattern was observed for all varieties of the cultigen and also for A. monticola. These results suggest that all presently known subspecies and varieties of A. hypogaea have arisen from a unique allotetraploid plant population, or alternatively, from different allotetraploid populations that originated from the same two diploid species. Furthermore, the bulk of the data demonstrated a close genomic relationship between both tetraploids and strongly supports the hypothesis that A. monticola is the immediate wild antecessor of A. hypogaea.

The 5S and the 18S-25S rRNA genes were physically mapped by fluorescent in situ hybridization (FISH) in all botanical varieties of cultivated peanut Arachis hypogaea (2n = 4x = 40), in the wild tetraploid A. monticola, and in seven wild diploid species considered as putative ancestors of the tetraploids. A detailed karyotype analysis including the FISH signals and the heterochromatic bands was carried out. Molecular cytogenetic landmarks are provided for the construction of a FISH-based karyotype in Arachis species. The size, number, and chromosome position of FISH signals and heterochromatic bands are similar in all A. hypogaea varieties and A. monticola, but vary among the diploid species. Genome constitution of the species is discussed and several chromosome homeologies are established. The bulk of the chromosome markers mapped, together with data on geographical distribution of the taxa, suggest that peanut originated upon domestication of A. monticola and evidence that the diploids A. duranensis and A. ipaensis are the most probable ancestors of both tetraploid species. Allopolyploidy could have arisen by a single event or, if by multiple events, always from the same diploid species.

Computer simulation models are mathematical equations combined in a structured framework to represent some real or hypothetical system. One of their uses is to allow the projection of short-term data from clinical trials to evaluate clinical outcomes and costs over a long-term period. This technology is becoming increasingly important to assist decision making in modern medicine in situations where there is a paucity of long-term clinical trial data, as recently acknowledged in the American Diabetes Association Consensus Panel Guidelines for Computer Modeling of Diabetes and its Complications. The Mount Hood Challenge Meetings provide a forum for computer modelers of diabetes to discuss and compare models and identify key areas of future development to advance the field. The Fourth Mount Hood Challenge in 2004 was the first meeting of its kind to ask modelers to perform simulations of outcomes for patients in published clinical trials, allowing comparison against "real life" data. Eight modeling groups participated in the challenge. Each group was given three of the following challenges: to simulate a trial of type 2 diabetes (CARDS [Collaborative Atorvastatin Diabetes Study]); to simulate a trial of type 1 diabetes (DCCT [Diabetes Control and Complications Trial]); and to calculate outcomes for a hypothetical, precisely specified patient (cross-model validation). The results of the models varied from each other and for methodological reasons, in some cases, from the published trial data in important ways. This approach of performing systematic comparisons and validation exercises has enabled the identification of key differences among the models, as well as their possible causes and directions for improvement in the future.

The legume Arachis hypogaea , commonly known as peanut or groundnut, is a very important food crop throughout the tropics and sub-tropics. The genus is endemic to South America being mostly associated with the savannah-like Cerrado. All species in the genus are unusual among legumes in that they produce their fruit below the ground. This profoundly influences their biology and natural distributions. The species occur in diverse habitats including grasslands, open patches of forest and even in temporarily flooded areas. Based on a number of criteria, including morphology and sexual compatibilities, the 80 described species are arranged in nine infrageneric taxonomic sections. While most wild species are diploid, cultivated peanut is a tetraploid. It is of recent origin and has an AABB-type genome. The most probable ancestral species are Arachis duranensis and Arachis ipaënsis , which contributed the A and B genome components, respectively. Although cultivated peanut is tetraploid, genetically it behaves as a diploid, the A and B chromosomes only rarely pairing during meiosis. Although morphologically variable, cultivated peanut has a very narrow genetic base. For some traits, such as disease and pest resistance, this has been a fundamental limitation to crop improvement using only cultivated germplasm. Transfer of some wild resistance genes to cultivated peanut has been achieved, for instance, the gene for resistance to root-knot nematode. However, a wider use of wild species in breeding has been hampered by ploidy and sexual incompatibility barriers, by linkage drag, and historically, by a lack of the tools needed to conveniently confirm hybrid identities and track introgressed chromosomal segments. In recent years, improved knowledge of species relationships has been gained by more detailed cytogenetic studies and molecular phylogenies. This knowledge, together with new tools for genetic and genomic analysis, will help in the more efficient use of peanut's genetic resources in crop improvement.

In light of growing interest in data-driven methods for oceanic, atmospheric, and climate sciences, this work focuses on the field of data assimilation and presents the analog data assimilation (AnDA). The proposed framework produces a reconstruction of the system dynamics in a fully data-driven manner where no explicit knowledge of the dynamical model is required. Instead, a representative catalog of trajectories of the system is assumed to be available. Based on this catalog, the analog data assimilation combines the nonparametric sampling of the dynamics using analog forecasting methods with ensemble-based assimilation techniques. This study explores different analog forecasting strategies and derives both ensemble Kalman and particle filtering versions of the proposed analog data assimilation approach. Numerical experiments are examined for two chaotic dynamical systems: the Lorenz-63 and Lorenz-96 systems. The performance of the analog data assimilation is discussed with respect to classical model-driven assimilation. A Matlab toolbox and Python library of the AnDA are provided to help further research building upon the present findings.

Abstract Confluence–diffluence units are key elements within many river networks, having a major impact upon the routing of flow and sediment, and hence upon channel change. Although much progress has been made in understanding river confluences, and increasing attention is being paid to bifurcations and the important role of bifurcation asymmetry, most studies have been conducted in laboratory flumes or within small rivers with width:depth (aspect) ratios less than 50. This paper presents results of a field‐based study that details the bed morphology and 3D flow structure within a very large confluence–diffluence in the Río Paraná, Argentina, with a width:depth ratio of approximately 200. Flow within the confluence–diffluence is dominated largely by the bed roughness, in the form of sand dunes; coherent, channel‐scale, secondary flow cells, that have been identified as important aspects of the flow field within smaller channels, and assumed to be present within large rivers, are generally absent in this reach. This finding has profound implications for flow mixing rates, sediment transport rates and pathways, and thus the interpretation of confluence–diffluence morphology and sedimentology. Copyright © 2006 John Wiley & Sons, Ltd.

Airborne and satellite observations show that when large rivers join they can take hundreds of kilometers to mix completely but, on occasion, may mix very rapidly. Application of established semitheoretical analyses shows that long mixing lengths should be expected. The first measurements of mixing processes at a large river junction (Río Paraná and Río Paraguay, Argentina, combined width ∼2.8 km) are presented at two occasions: first when they mix in >400 km, and second when mixing is complete in only 8 km downstream of the junction. For the case of slower mixing, at‐a‐point surveys showed that mixing driven by turbulent shear associated with a near‐vertical shear layer was restricted to close to the junction (to 0.272 multiples of the postconfluence width downstream). Transect surveys showed penetration of more turbid water from the Río Paraguay underneath the Río Paraná, but this was insufficient to promote more rapid mixing. There was no clear channel‐scale circulation present and slow mixing was compounded by reverse topographic forcing on the mainstream Río Paraná side of the river. This kept more turbid water on the Río Paraguay side of the river, close to the bed. In the case of rapid mixing, we found clear channel‐scale circulation. The momentum ratio between the combining flows reinforced the effects of the discordance in bed height between the tributaries at the confluence and allowed penetration of more turbid Río Paraguay water further across the channel width deeper within the flow. The importance of the interaction between momentum ratio and bed morphology at channel junctions makes mixing rates at the confluence dependent upon basin‐scale hydrological response, which is more likely to differ between large confluent rivers than small rivers, as a result of the different climatic/topographic zones that they may capture.

Primates show activity patterns ranging from nocturnality to diurnality, with a few species showing activity both during day and night. Among anthropoids (monkeys, apes and humans), nocturnality is only present in the Central and South American owl monkey genus Aotus. Unlike other tropical Aotus species, the Azara's owl monkeys (A. azarai) of the subtropics have switched their activity pattern from strict nocturnality to one that also includes regular diurnal activity. Harsher climate, food availability, and the lack of predators or diurnal competitors, have all been proposed as factors favoring evolutionary switches in primate activity patterns. However, the observational nature of most field studies has limited an understanding of the mechanisms responsible for this switch in activity patterns. The goal of our study was to evaluate the hypothesis that masking, namely the stimulatory and/or inhibitory/disinhibitory effects of environmental factors on synchronized circadian locomotor activity, is a key determinant of the unusual activity pattern of Azara's owl monkeys. We use continuous long-term (6-18 months) 5-min-binned activity records obtained with actimeter collars fitted to wild owl monkeys (n = 10 individuals) to show that this different pattern results from strong masking of activity by the inhibiting and enhancing effects of ambient luminance and temperature. Conclusive evidence for the direct masking effect of light is provided by data showing that locomotor activity was almost completely inhibited when moonlight was shadowed during three lunar eclipses. Temperature also negatively masked locomotor activity, and this masking was manifested even under optimal light conditions. Our results highlight the importance of the masking of circadian rhythmicity as a determinant of nocturnality in wild owl monkeys and suggest that the stimulatory effects of dim light in nocturnal primates may have been selected as an adaptive response to moonlight. Furthermore, our data indicate that changes in sensitivity to specific environmental stimuli may have been an essential key for evolutionary switches between diurnal and nocturnal habits in primates.

BACKGROUND: After trans-catheter aortic valve implantation (TAVI), the need for postinterventional pacemaker (PM) implantation can occur in as many as 10-50% of cases, but it is not yet clear, how this need can be predicted. The aim of this study was to assess the possible predictive factors of post TAVI PM implantation based on Computed Tomography (CT) measured aortic valve calcification and its distribution. METHODS: We prospectively analyzed 81 consecutive symptomatic patients with severe AS scheduled for TAVI using the CoreValve prosthesis (Medtronic, Minneapolis, USA). In all patients, a native and contrast-enhanced multislice cardiac CT was performed preinterventionally, estimating calcification load of the native valve cusps and of the adjacent outflow tract (so called "device landing zone", DLZ) by the Agatston Score (AgS). Objective, computer-evaluated, preprocedural ECG-analysis was performed with regards to pre-existing conduction abnormalities. Transthoracic echocardiography was performed pre and post TAVI. RESULTS: TAVI was successful in all cases. PM implantation was deemed necessary in altogether 32 patients, out of 67 without a PM pre-TAVI (32/67, 47%). Various parameters were tested as predictors of post TAVI PM in a multivariate logistic regression analysis model. Female sex (P = 0,005) and depressed EF (P = 0,023) showed a significant correlation. PM implantation correlated also to the DLZ calcification, as assessed by CT (P = 0,004). This model leads to an AUC (area under the ROC-receiver operator characteristics-curve) of 0.83. CONCLUSION: Calcium amount in the CoreValve DLZ in combination with clinical data could predict the need for post TAVI PM implantation.

Abstract. Effects of grazing and environment on vegetation structure have been widely acknowledged, but few studies have related both factors. We made 57 floristic samples in a highly variable landscape of mountain grasslands in central Argentina; 26 sample were in fence‐lines with contrasting vegetation. For each sample, we recorded topographic and edaphic parameters, as well as grazing intensity indicators. Floristic gradients were analysed with DCA and relations with abiotic and grazing‐related variables were detected with DCCA. Floristic axis 1 was explained by edaphic parameters associated to topography, ranging from communities in well drained soils on upper topographic positions to hydromorphic vegetation in poorly drained soils on lower topographic positions. Species richness decreased as soil moisture increased. Floristic axis 2 was associated with present and long‐term grazing indicators, and reflected shifts in vegetation physiognomy and species evenness. Tall tussock grasslands, with low species evenness and evidences of low or null grazing intensity were located at one extreme. Tussocks were gradually replaced by short graminoids and forbs towards the centre of the gradient, as grazing increased, and evenness reached a maximum. In degraded sites with heavy long‐term grazing intensities, short perennial species were replaced by an annual species, and evenness decreased. The magnitude of changes in floristic composition produced by grazing decreased with increasing soil moisture, and vegetation‐environment relationships were stronger in moderate to highly grazed situations than in lightly or non grazed situations.

We describe a new method for estimating population density of vocally responsive animals, which is based on playback calls coupled with auditory point transect sampling. The method yielded, for red titi monkeys (Callicebus discolor), better estimates than traditional line transect surveys. We propose it as an effective alternative for sampling certain cryptic, but vocally responsive animal species. Describimos un nuevo método para estimar la densidad poblacional de animales que combina muestreos puntuales auditivos con la utilización de grabaciones de llamadas. En el caso del mono titi rojo (Callicebus discolor), el método resultó en mejores estimaciones que las obtenidas con el tradicional muestreo de transectas lineares. Proponemos el método como una alternativa válida para muestrear ciertas especies de animales que son crípticas pero que responden vocalmente.

AIMS: Hyponatraemia has been associated with reduced survival in patients with heart failure and reduced ejection fraction (HF-REF). The relationship between serum sodium and outcome is unclear in heart failure with preserved (≥ 50%) ejection fraction (HF-PEF). Therefore, we used a large individual patient data meta-analysis to study the risk of death associated with hyponatraemia in HF-REF and in HF-PEF. METHODS AND RESULTS: This analysis included 14 766 patients from 22 studies that recruited patients without ejection fraction inclusion criterion at baseline and reported death from any cause. Cox proportional analysis was undertaken for hyponatraemia (sodium <135 mmol/L), adjusted for variables of clinical relevance, and stratified by study. The endpoint was death from any cause at 3 years. Patients with hyponatraemia (n = 1618) and patients with normal serum sodium had similar characteristics as regards to age, gender, and ischaemic aetiology. However, patients with hyponatraemia had higher New York Heart Association class and lower blood pressure. At follow-up, there were 335 deaths among 1618 patients with hyponatraemia (21%) and 2128 deaths among 13 148 patients with normal serum sodium (16%). The risk of death appeared to increase linearly with serum sodium levels <140 mmol/L. Hyponatraemia was identified in 1199 HF-REF patients (11%) and 419 HF-PEF patients (11%). Hyponatraemia was independently predictive of death in both HF-REF [adjusted hazard ratio (HR) 1.69, 95% confidence interval (CI) 1.50-1.91] and HF-PEF (adjusted HR 1.40, 95% CI 1.10-1.79, P for interaction 0.20). CONCLUSION: Hyponatraemia is a powerful determinant of mortality in patients with HF regardless of ejection fraction. Further work is needed to determine if correction of hyponatraemia translates into clinical benefit.

Abstract Data assimilation combines forecasts from a numerical model with observations. Most of the current data assimilation algorithms consider the model and observation error terms as additive Gaussian noise, specified by their covariance matrices and , respectively. These error covariances, and specifically their respective amplitudes, determine the weights given to the background (i.e., the model forecasts) and to the observations in the solution of data assimilation algorithms (i.e., the analysis). Consequently, and matrices significantly impact the accuracy of the analysis. This review aims to present and to discuss, with a unified framework, different methods to jointly estimate the and matrices using ensemble-based data assimilation techniques. Most of the methods developed to date use the innovations, defined as differences between the observations and the projection of the forecasts onto the observation space. These methods are based on two main statistical criteria: 1) the method of moments, in which the theoretical and empirical moments of the innovations are assumed to be equal, and 2) methods that use the likelihood of the observations, themselves contained in the innovations. The reviewed methods assume that innovations are Gaussian random variables, although extension to other distributions is possible for likelihood-based methods. The methods also show some differences in terms of levels of complexity and applicability to high-dimensional systems. The conclusion of the review discusses the key challenges to further develop estimation methods for and . These challenges include taking into account time-varying error covariances, using limited observational coverage, estimating additional deterministic error terms, or accounting for correlated noise.