114 research outputs found

    PATRONES DE LA MACROFAUNA EDAFICA EN UN CULTIVO DE ZEA MAIZ DURANTE LA FASE POSTCOSECHA EN LA MANCHA, VERACRUZ, MEXICO

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    The soil macrofauna of a cornfield was studied during the fallow period in El Centro de Investigaciones Costeras "La Mancha", Veracruz. Patterns of soil macrofauna density, spatial distribution and diversity were described and their relationships with soil temperature, moisture, organic matter and pH were explored. Four strategies were combined to undertake this aim: a) sampling of soil macrofauna was carried out in seven ten cm soil layers from 0 to 70 cm depth; b) soil macrofauna was identified to morphospecies level; c) the size of morphospecies aggregations was determined following a the two-term local quadrat variance method (TTLQV); d) analysis of canonical correspondence was used to arrange morphospecies distribution in an spatial and environmental framework of reference. Density of soil macrofauna in the studied site seems to be the lowest value ever recorded in similar studies (246 individuals m-2). Forty-six morphospecies were collected that are mainly distributed in the top 20 cm soil layer and present an aggregated horizontal pattern of distribution. The diameter of aggregations of Oligochaeta juveniles, larvae of Tenebrionidae and Diplopoda juveniles was >1.5m, 0.9 m and 1.2 m respectively. It was possible to arrange different groups of soil Macrofauna according with their ranges of tolerance to environmental variables. Therefore, it is suggested that these patterns do reflect preferences of soil biota to microenvironments and do respond to soil degradation.Estudiamos la macrofauna del suelo de un cultivo de Zea maiz durante la fase postcosecha en el Centro de Investigaciones Costeras La Mancha, Veracruz. Describimos patrones de densidad, distribución espacial y diversidad en relación con la temperatura, humedad y pH del suelo. Para esto conjuntamos cuatro estrategias: a) muestreamos la macrofauna en estratos de 10 cm hasta los 70 cm de profundidad; b) separamos la fauna a nivel de morfoespecie; c) estimamos el tamaño de las agregaciones de las morfoespecies mediante una técnica de cuadrante-varianza; y d) ordenamos, mediante un análisis de correspondencia canónica, morfoespecies y estratos en un marco de referencia ambiental. La densidad de la macrofauna del suelo estudiado es la más baja reportada hasta la fecha para agroecosistemas en el mundo (246 individuos/m2). Colectamos 46 morfoespecies, que se distribuyeron generalmente en el primer o segundo estrato del suelo y presentaron una distribución agregada. El diametro de las agregaciones de los Oligochaeta juveniles fue superior a 1.5 m y para las larvas de Tenebrionidae y los Diplopoda juveniles fue de 0.9 y 1.2 m, respectivamente. Debido a que es posible separar distintos grupos de acuerdo con sus rangos de tolerancia a la temperatura, pH, humedad y materia orgánica en el suelo, es factible que los patrones de distribución registrados sean un reflejo de las preferencias de la biota a diferentes microambientes y al estado de degradación del suelo

    Monitoring coral reefs within the Reef 2050 Integrated Monitoring and Reporting Program: final report of the coral reef expert group

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    [Extract] The Coral Reef Expert Group (CREG) was one of eight expert groups, which all followed a prescribed process to recommend a design for their thematic component. The tasks of the expert groups included: • Synopsis of the theme, to include discussion on current state, primary drivers, pressures and responses using DPSIR framework. • Review of all current monitoring and modelling activities relevant to the expert group theme. • Identify candidate indicators that can be monitored and would provide information about trend, status or forecasting of value or the system. • Evaluation of the adequacy and confidence of current monitoring and modelling of candidate indicators, determined by their ability to meet the objectives of the RIMReP and management needs provided by the Authority. • Identification and discussion of gaps and opportunities in current monitoring and modelling of such indicators. • Evaluation of new monitoring technologies for their potential to increase efficiency or statistical power and their compatibility with long-term datasets. • Recommendations for monitoring design including consideration of primary indicators, continuity of data sets, how the design addresses management needs, modification to existing programs, costing and transition strategies.An accessible copy of this report is not yet available from this repository, please contact [email protected] for more information

    Global Analysis of the post-SNO Solar Neutrino Data for Standard and Non-Standard Oscillation Mechanisms

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    What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time, using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: (a) neutrino mass and mixing, (b) non-vanishing neutrino magnetic moment, (c) the existence of non-standard flavor-changing and non-universal neutrino interactions and (d) the tiny violation of the equivalence principle. We investigate the quality of the fit provided by each one of these solutions not only to the total rate measured by all the solar neutrino experiments but also to the recoil electron energy spectrum measured at different zenith angles by the Super-Kamiokande collaboration. We conclude that several non-standard neutrino flavor conversion mechanisms provide a very good fit to the experimental data which is comparable with (or even slightly better than) the most famous solution to the solar neutrino anomaly based on the neutrino oscillation induced by mass.Comment: Minor changes in the solar magnetic field profile used, and some refferences added. Final version to appear in PR

    Ultracool dwarf benchmarks with \emph{Gaia} primaries

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool dwarf companions to \emph{Gaia} primary stars is generated and assessed. Of order \sim24,000 companions should be identifiable outside of the Galactic plane (b>10|b| > 10\,deg) with large-scale ground- and space-based surveys including late M, L, T, and Y types. Our simulated companion parameter space covers 0.02M/M0.10.02 \le M/M_{\odot} \le 0.1, 0.1age/Gyr140.1 \le {\rm age/Gyr} \le 14, and 2.5[Fe/H]0.5-2.5 \le {\rm [Fe/H]} \le 0.5, with systems required to have a false alarm probability 0.6\, kau}\,Peer reviewedFinal Accepted Versio

    Los Artrópodos de La reserva natural Río Ñambí

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    ilustraciones, fotografías, mapasLa presente guía de campo, presenta una diagramación vistosa, con fo- tografías de alta calidad, una información biológica básica y entendible para los iniciados al conocimiento de los distintos grupos taxonómicos presentados. El glosario incluido al final de la obra, resulta un comple- mento indispensable para el aprendizaje de la terminología en cada uno de los grupos. Con esta publicación, enmarcada en el seriado Guías de Campo del Instituto de Ciencias Naturales, se ratifica uno de los objetivos institucionales como es el de proyectar el conocimiento generado en el Instituto a todos los protagonistas de la sociedad colombiana: ciudadanos del campo, estudiantes, profesores, investigadores, ambientalistas, líderes comunitarios y autoridades, entre otros. Que esta guía permita a todos sus afortunados lectores descubrir la magia y los secretos de la enigmática biodiversidad colombiana. (texto tomado de la fuente)Presentación -- Agradecimientos --11 Introducción -- La Reserva Natural Rio Ñambí y sus artrópodos -- Clase Arachnida -- Orden Aranae -- Orden Scorpiones -- Orden Pseudoscorpiones (Chelonethi) -- Orden Opiliones -- Clase Insecta -- Orden Odonata -- Orden Orthoptera -- Orden Phasmatodea -- Orden Dermaptera -- Orden Hemiptera -- Orden Hymenoptera -- Orden Coleoptera -- Orden Diptera -- Orden Lepidoptera -- Myriapoda -- Clase Diplopoda -- Orden Polyxenida -- Orden Glomeridesmida -- Orden Siphonophorida -- Orden Stemmiulida -- Orden Spirobolida -- Orden Polydesmida -- Clase Chilopoda -- Orden Scolopendromorpha -- Orden Scutigeromorpha -- Orden Geophilomorpha -- Glosari

    Alpine bogs of southern Spain show human-induced environmental change superimposed on long-term natural variations

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    Recent studies have proved that high elevation environments, especially remote wetlands, are exceptional ecological sensors of global change. For example, European glaciers have retreated during the 20th century while the Sierra Nevada National Park in southern Spain witnessed the first complete disappearance of modern glaciers in Europe. Given that the effects of climatic fluctuations on local ecosystems are complex in these sensitive alpine areas, it is crucial to identify their long-term natural trends, ecological thresholds, and responses to human impact. In this study, the geochemical records from two adjacent alpine bogs in the protected Sierra Nevada National Park reveal different sensitivities and long-term environmental responses, despite similar natural forcings, such as solar radiation and the North Atlantic Oscillation, during the late Holocene. After the Industrial Revolution both bogs registered an independent, abrupt and enhanced response to the anthropogenic forcing, at the same time that the last glaciers disappeared. The different response recorded at each site suggests that the National Park and land managers of similar regions need to consider landscape and environmental evolution in addition to changing climate to fully understand implications of climate and human influence.This study was supported by the project P11-RNM 7332 of the “Junta de Andalucía”, the projects CGL2013-47038-R and CGL2015-67130-C2-1-R of the “Ministerio de Economía y Competitividad of Spain and Fondo Europeo de Desarrollo Regional FEDER” and the research group RNM0190 and RNM309 (Junta de Andalucía). A.G.-A. was also supported by a Marie Curie Intra-European Fellowship of the 7th Framework Programme for Research, Technological Development and Demonstration of the European Commission (NAOSIPUK. Grant Number: PIEF-GA-2012-623027) and by a Ramón y Cajal Fellowship RYC-2015-18966 of the Spanish Government (Ministerio de Economía y Competividad). J.L.T. was also supported by a Small Research Grant by the Carnegie Trust for the Universities of Scotland and hosted the NAOSIPUK project (PIEF-GA-2012-623027). M. J. R-R acknowledges the PhD funding provided by Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía (P11-RNM 7332)

    Chapter 5 Priority Species to Support the Functional Integrity of Coral Reefs

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    Ecosystem-based management on coral reefs has historically focused on biodiversity conservation through the establishment of marine reserves, but it is increasingly recognised that a subset of species can be key to the maintenance of ecosystem processes and functioning. Specific provisions for these key taxa are essential to biodiversity conservation and resilience-based adaptive management. While a wealth of literature addresses ecosystem functioning on coral reefs, available information covers only a subset of specific taxa, ecological processes and environmental stressors. What is lacking is a comparative assessment across the diverse range of coral reef species to synthesise available knowledge to inform science and management. Here we employed expert elicitation coupled with a literature review to generate the first comprehensive assessment of 70 taxonomically diverse and functionally distinct coral reef species from microbes to top predators to summarise reef functioning. Although our synthesis is largely through the lens of the Great Barrier Reef, Australia, a particularly data-rich system, it is relevant to coral reefs in general. We use this assessment to evaluate which taxa drive processes that maintain a healthy reef, and whether or not management of these taxa is considered a priority (i.e. are they vulnerable?) or is feasible (i.e. can they be managed?). Scientific certainty was scored to weight our recommendations, particularly when certainty was low. We use five case studies to highlight critical gaps in knowledge that limit our understanding of ecosystem functioning. To inform the development of novel management strategies and research objectives, we identify taxa that support positive interactions and enhance ecosystem performance, including those where these roles are currently underappreciated. We conclude that current initiatives effectively capture many priority taxa, but that there is significant room to increase opportunities for underappreciated taxa in both science and management to maximally safeguard coral reef functioning

    Misregulation of Scm3p/HJURP Causes Chromosome Instability in Saccharomyces cerevisiae and Human Cells

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    The kinetochore (centromeric DNA and associated proteins) is a key determinant for high fidelity chromosome transmission. Evolutionarily conserved Scm3p is an essential component of centromeric chromatin and is required for assembly and function of kinetochores in humans, fission yeast, and budding yeast. Overexpression of HJURP, the mammalian homolog of budding yeast Scm3p, has been observed in lung and breast cancers and is associated with poor prognosis; however, the physiological relevance of these observations is not well understood. We overexpressed SCM3 and HJURP in Saccharomyces cerevisiae and HJURP in human cells and defined domains within Scm3p that mediate its chromosome loss phenotype. Our results showed that the overexpression of SCM3 (GALSCM3) or HJURP (GALHJURP) caused chromosome loss in a wild-type yeast strain, and overexpression of HJURP led to mitotic defects in human cells. GALSCM3 resulted in reduced viability in kinetochore mutants, premature separation of sister chromatids, and reduction in Cse4p and histone H4 at centromeres. Overexpression of CSE4 or histone H4 suppressed chromosome loss and restored levels of Cse4p at centromeres in GALSCM3 strains. Using mutant alleles of scm3, we identified a domain in the N-terminus of Scm3p that mediates its interaction with CEN DNA and determined that the chromosome loss phenotype of GALSCM3 is due to centromeric association of Scm3p devoid of Cse4p/H4. Furthermore, we determined that similar to other systems the centromeric association of Scm3p is cell cycle regulated. Our results show that altered stoichiometry of Scm3p/HJURP, Cse4p, and histone H4 lead to defects in chromosome segregation. We conclude that stringent regulation of HJURP and SCM3 expression are critical for genome stability

    Complement component 3 (C3) expression in the hippocampus after excitotoxic injury: role of C/EBPβ

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    [Background] The CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor implicated in the control of proliferation, differentiation, and inflammatory processes mainly in adipose tissue and liver; although more recent results have revealed an important role for this transcription factor in the brain. Previous studies from our laboratory indicated that CCAAT/enhancer-binding protein β is implicated in inflammatory process and brain injury, since mice lacking this gene were less susceptible to kainic acid-induced injury. More recently, we have shown that the complement component 3 gene (C3) is a downstream target of CCAAT/enhancer-binding protein β and it could be a mediator of the proinflammatory effects of this transcription factor in neural cells.[Methods] Adult male Wistar rats (8–12 weeks old) were used throughout the study. C/EBPβ+/+ and C/EBPβ–/– mice were generated from heterozygous breeding pairs. Animals were injected or not with kainic acid, brains removed, and brain slices containing the hippocampus analyzed for the expression of both CCAAT/enhancer-binding protein β and C3.[Results] In the present work, we have further extended these studies and show that CCAAT/enhancer-binding protein β and C3 co-express in the CA1 and CA3 regions of the hippocampus after an excitotoxic injury. Studies using CCAAT/enhancer-binding protein β knockout mice demonstrate a marked reduction in C3 expression after kainic acid injection in these animals, suggesting that indeed this protein is regulated by C/EBPβ in the hippocampus in vivo.[Conclusions] Altogether these results suggest that CCAAT/enhancer-binding protein β could regulate brain disorders, in which excitotoxic and inflammatory processes are involved, at least in part through the direct regulation of C3.This work was supported by MINECO, Grant SAF2014-52940-R and partially financed with FEDER funds. CIBERNED is funded by the Instituto de Salud Carlos III. JAM-G was supported by CIBERNED. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe

    Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns

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    This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa
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