326 research outputs found

    Light Converts Endosymbiotic Fungus to Pathogen, Influencing Seedling Survival and Niche-Space Filling of a Common Tropical Tree, Iriartea deltoidea

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    Pathogens are hypothesized to play an important role in the maintenance of tropical forest plant species richness. Notably, species richness may be promoted by incomplete filling of niche space due interactions of host populations with their pathogens. A potentially important group of pathogens are endophytic fungi, which asymptomatically colonize plants and are diverse and abundant in tropical ecosystems. Endophytes may alter competitive abilities of host individuals and improve host fitness under stress, but may also become pathogenic. Little is known of the impacts of endophytes on niche-space filling of their hosts

    External asymmetries in the Euro area and the role of foreign direct investment

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    Soon after the introduction of the common currency, a divide emerged between two groups in the Euro area: one comprised of the North-European countries achieving external surpluses and the other of the South-European countries with large external deficits. This paper shows that different patterns of Foreign Direct Investment (FDI) inflows across the Euro area countries contributed to this divergence. Our theoretical framework shows that if the economy is relatively capital-intensive in the production of traded (non-traded) output, FDI will be channeled in greater proportions to the traded (non-traded) sector, thus improving (deteriorating) the trade balance. Focusing on ten Euro area countries over the period 1980- 2009, we establish a positive (negative) long-run effect of FDI inflows on the trade balance in the North (South). In the North the positive effect stems from the traded-sector FDI inflows that were significantly higher in comparison to the South, both before and after the EMU. In contrast, in the South the increased FDI inflows in the post-EMU era were dominated by investments in the non-traded sector. When industry-level data are employed, a positive (negative) long-run effect of manufacturing (non-manufacturing) FDI inflows on the trade balance in the North (South) is further established

    Manual para la evaluación de tecnologías sanitarias, versión corta

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    The objective of this article is to present the methodological guidelines established in the manual of Short Health Technology Assessment, which were developed by the Peruvian National Network of Health Technology Assessments. The purpose of the manual is to standardize the methodologies of development of Short Health Technology Assessments between institutions of health technology assessment. This manual seeks to contribute to evidence-informed decision-making to improve the population's access to safe and effective health technologies in PeruEl objetivo de este artículo es presentar las pautas metodológicas establecidas en el manual de Evaluaciones Tecnológicas Sanitarias Cortas, que fueron desarrolladas por la Red Nacional de Evaluación de Tecnologías Sanitarias del Perú. El propósito del manual es estandarizar las metodologías de desarrollo de las Evaluaciones Tecnológicas Sanitarias Cortas entre las instituciones de evaluación de tecnologías de salud. Con la elaboración de este manual se busca contribuir a la toma de decisiones informada en evidencia para mejorar el acceso de la población a tecnologías sanitarias seguras y eficaces en el país

    3′UTR-Mediated Gene Silencing of the Mixed Lineage Leukemia (MLL) Gene

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    Translocations involving the Mixed Lineage Leukemia (MLL) gene generate in-frame fusions of MLL with more than 50 different partner genes (PGs). Common to all MLL translocations is the exchange not only of coding regions, but also of MLL and PG 3′-untranslated regions (3′UTRs). As a result, the MLL-PG fusion is normally highly expressed and considered the main driver of leukemia development, whereas the function of the PG-MLL fusions in leukemic disease is unclear. As 3′UTRs have been recognized as determinant regions for regulation of gene expression, we hypothesized that loss of the MLL 3′UTR could have a role in generating high MLL-PG levels and leukemia development. Here, we first tested the MLL-PG and PG-MLL mRNA levels in different leukemic cells and tumours and uncovered differential expression that indicates strong repression by the MLL-3′UTR. Reporter assays confirmed that the 3′UTR of MLL, but not of its main PGs, harbours a region that imposes a strong gene silencing effect. Gene suppression by the MLL 3′UTR was largely microRNA independent and did not affect mRNA stability, but inhibited transcription. This effect can at least partially be attributed to a tighter interaction of the MLL 3′UTR with RNA polymerase II than PG 3′UTRs, affecting its phosphorylation state. Altogether, our findings indicate that MLL translocations relieve oncogenic MLL-PG fusions from the repressive MLL 3′UTR, contributing to higher activity of these genes and leukaemia development

    Herbaceous plants in the understory of a pitch canker-affected Pinus radiata plantation are endophytically infected with Fusarium circinatum

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    [EN] Fusarium circinatum was recently detected as an endophyte in grasses causing no apparent damage. Our goal was to describe the endophytic colonization of herbaceous host plants growing in a plantation of Pinus radiata with symptoms of pitch canker disease, which may act as a reservoir of inoculum. We detected the fungus in five species of dicot families (Asteraceae, Lamiaceae, Rosaceae), in addition to two species in the Poaceae. The fungus was found in the aerial part of non-symptomatic hosts, so we describe E circinatum as an endophyte that is mainly transmitted by spores through the air. It was also detected in Hypochaeris radicata seeds, suggesting the potential occurrence of vertical transmission. An analysis of microsatellite markers showed a unique haplotype regardless of whether the isolates' origin was pine cankers or non-symptomatic herbaceous plants. Thus, the same genotype can adopt a pathogenic or endophytic lifestyle. We conclude that non -symptomatic plants can act as reservoirs of inoculum: pine seedlings can be infeded from senescent tissue of non-symptomatic hosts colonized by the fungus. (C) 2017 Elsevier Ltd and British Mycological Society. All rights reserved.We acknowledge Maite Morales Clemente for her excellent technical assistance and Inigo Zabalgogeazcoa for his helpful suggestions. Laura Hernandez was supported by a fellowship from INIA (FPI-INIA). Financial support for this research was provided by projects RTA2012-00015-C02-01 and RTA2013-00048-C03-01 (Programa Estatal I + D + i, INIA, Spain).Hernandez-Escribano, L.; Iturritxa, E.; Elvira-Recuenco, M.; Berbegal Martinez, M.; Campos, J.; Renobales, G.; García, I.... (2018). Herbaceous plants in the understory of a pitch canker-affected Pinus radiata plantation are endophytically infected with Fusarium circinatum. Fungal Ecology. 32:65-71. https://doi.org/10.1016/j.funeco.2017.12.001S65713

    A Tale of Two Markets: How Lower-end Borrowers Are Punished for Bank Regulatory Failures in Nigeria

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    In 2009, the Nigerian banking system witnessed a financial crisis caused by elite borrowers in the financial market. Regulatory response to the Nigerian crisis closely mirrored the international response with increased capital and liquidity thresholds for commercial banks. While the rise of consumer protection on the agenda of prudential supervisors internationally was logical in that consumer debt was the main cause of the global recession, the Nigerian banking reforms of 2009 disproportionately affected access by poorer consumers, who ironically had little to do with the underlying causes of the crisis. As lending criteria become more stringent, poorer consumers of credit products are pushed into informal markets because of liquidity-induced credit rationing. Overall, consumer protection is compromised because stronger consumer protection rules for the formal sector benefits borrowers from formal institutions who constitute the minority of borrowers in all markets. While the passage of regulation establishing credit bureaux and the National Collateral Registry will, in theory, ease access to credit especially by lower-end borrowers, the vast size of the informal market continues to compound the information asymmetry problem, fiscal policies to tackle structural economic issues such as unemployment and illiteracy remain to be initiated, and bank regulators continue to pander to elite customers with policy responses that endorse too big to fail but deems lower-end consumers too irrelevant to save. The essay concluded that addressing the wide disparity in access to credit between the rich and poor through property rights reforms to capture the capital of the informal class, promoting regulation to check loan concentration, and stimulating competition by allowing Telecommunication Companies (TELCOs) and fintech companies to carry on lending activities because of their superior knowledge of lower-end markets will facilitate greater access. The risk of systemic failure deriving from consumer credit in Nigeria is insignificant compared to the consumer vulnerabilities resulting from the exposure of consumers to unregulated products in the informal market

    No silver bullet for digital soil mapping: country-specific soil organic carbon estimates across Latin America.

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    Country-specific soil organic carbon (SOC) estimates are the baseline for the Global SOC Map of the Global Soil Partnership (GSOCmap-GSP). This endeavor is key to explaining the uncertainty of global SOC estimates but requires harmonizing heterogeneous datasets and building country-specific capacities for digital soil mapping (DSM).We identified country-specific predictors for SOC and tested the performance of five predictive algorithms for mapping SOC across Latin America. The algorithms included support vector machines (SVMs), random forest (RF), kernel-weighted nearest neighbors (KK), partial least squares regression (PL), and regression kriging based on stepwise multiple linear models (RK). Country-specific training data and SOC predictors (5 x 5 km pixel resolution) were obtained from ISRIC - World Soil Information. Temperature, soil type, vegetation indices, and topographic constraints were the best predictors for SOC, but country-specific predictors and their respective weights varied across Latin America. We compared a large diversity of country-specific datasets and models, and were able to explain SOC variability in a range between ~ 1 and ~ 60 %, with no universal predictive algorithm among countries. A regional (n = 11 268 SOC estimates) ensemble of these five algorithms was able to explain ~ 39% of SOC variability from repeated 5-fold cross-validation.We report a combined SOC stock of 77.8 +- 43.6 Pg (uncertainty represented by the full conditional response of independent model residuals) across Latin America. SOC stocks were higher in tropical forests (30 +- 16.5 Pg) and croplands (13 +- 8.1 Pg). Country-specific and regional ensembles revealed spatial discrepancies across geopolitical borders, higher elevations, and coastal plains, but provided similar regional stocks (77.8 +- 42.2 and 76.8 +- 45.1 Pg, respectively). These results are conservative compared to global estimates (e.g., SoilGrids250m 185.8 Pg, the Harmonized World Soil Database 138.4 Pg, or the GSOCmap-GSP 99.7 Pg). Countries with large area (i.e., Brazil, Bolivia, Mexico, Peru) and large spatial SOC heterogeneity had lower SOC stocks per unit area and larger uncertainty in their predictions. We highlight that expert opinion is needed to set boundary prediction limits to avoid unrealistically high modeling estimates. For maximizing explained variance while minimizing prediction bias, the selection of predictive algorithms for SOC mapping should consider density of available data and variability of country-specific environmental gradients. This study highlights the large degree of spatial uncertainty in SOC estimates across Latin America. We provide a framework for improving country-specific mapping efforts and reducing current discrepancy of global, regional, and country-specific SOC estimates
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