Interannuale Klimavariabilität im tropischen Indischen Ozean: Eine Untersuchung mit einer Hierarchie von globalen gekoppelten Ozean-Atmosphären-Modellen

The Indian Ocean shows significant climate variability at interannual timescales. This variability is affected by the El Niño--Southern Oscillation (ENSO) phenomenon. A hier-archy of coupled model simulations is used as well as observational datasets and reanaly-sis products to investigate the role ENSO plays in determining the interannual climate variability in the Indian Ocean and to investigate the spatial and temporal characteristics of the ENSO--independent climate variability. The hierarchy of coupled model simula-tions comprises three experiments. Two experiments are conducted with the ECHO-G model, which is a state--of--the--art ocean--atmosphere general circulation model (CGCM). The first experiment with ECHO-G is a standard integration, which serves as a control integration. The second experiment with ECHO-G is similar to the control ex-periment but the interannual ocean--atmosphere interactions have been inhibited in the tropical Pacific Ocean, so that in this experiment the ENSO signal is excluded by defini-tion. The third experiment is conducted with a fixed--depth mixed--layer model coupled to the same atmosphere model that has been used in the two experiments with ECHO-G. This integration allows the investigation of the role of ocean dynamics in the generation of interannual sea surface temperature (SST) variability. It is shown that the variability of several atmospheric and oceanic fields in the Indian Ocean region, including SST, is consistent with a cycle only if ENSO is included in the simulation. The ENSO signature in the Indian Ocean includes both a dynamical and a thermodynamical response. ENSO influences the Indian Ocean at two different interannual timescales and provides conditions favorable for coupled ocean-atmosphere interac-tions in the Indian Ocean. In contrast, the climate variability that is independent of ENSO shows a response of the ocean to the atmospheric forcing that is not significantly more energetic than expected from a stochastic forcing approach, thereby reflecting either a passive oceanic response or weak coupling in the ENSO independent Indian Ocean variability

Wind-driven Rossby waves in the tropical South Indian Ocean with and without an active ENSO

The interannual heat content variability in the tropical south Indian Ocean (SIO) and its relationship with El Niño–Southern Oscillation (ENSO) is studied. The baroclinic ocean response to stochastic wind stress predicted by a simple analytical model is compared with two integrations of the ECHO-G coupled general circulation model. In one integration, ocean–atmosphere interactions are suppressed in the tropical Pacific Ocean, so that this integration does not simulate ENSO. In the other integration, interactions are allowed everywhere and ENSO is simulated. The results show that basinwide variability in the SIO heat content can be produced by two mechanisms: 1) oscillatory forcing by ENSO-related wind stress and 2) temporally stochastic and spatially coherent wind stress forcing. Previous studies have shown that transmission of energy from the tropical Pacific to the southern Indian Ocean occurs through coastal Kelvin waves along the western coast of Australia. The results in this paper confirm the occurrence of such transmission. In the ECHO-G simulations, this transmission occurs both at the annual time scale and at interannual time scales. Generation of offshore Rossby waves by these coastal Kelvin waves at interannual time scales—and, in particular, at the ENSO time scale—was found

Identification and Functional Characterization of Two Intronic NIPBL Mutations in Two Patients with Cornelia de Lange Syndrome

Cornelia de Lange syndrome (CdLS) is a rare genetically heterogeneous disorder with a high phenotypic variability including mental retardation, developmental delay, and limb malformations. The genetic causes in about 30% of patients with CdLS are still unknown. We report on the functional characterization of two intronic NIPBL mutations in two patients with CdLS that do not affect a conserved splice-donor or acceptor site. Interestingly, mRNA analyses showed aberrantly spliced transcripts missing exon 28 or 37, suggesting the loss of the branch site by the c.5329-15A>G transition and a disruption of the polypyrimidine by the c.6344del(-13)-(-8) deletion. While the loss of exon 28 retains the reading frame of the NIBPL transcript resulting in a shortened protein, the loss of exon 37 shifts the reading frame with the consequence of a premature stop of translation. Subsequent quantitative PCR analysis demonstrated a 30% decrease of the total NIPBL mRNA levels associated with the frameshift transcript. Consistent with our results, this patient shows a more severe phenotype compared to the patient with the aberrant transcript that retains its reading frame. Thus, intronic variants identified by sequencing analysis in CdLS diagnostics should carefully be examined before excluding them as nonrelevant to disease

Low-frequency variability of the Indian monsoon-ENSO relationship and the tropical Atlantic : the "Weakening" of the 1980s and 1990s

Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 20 (2007): 4255-4266, doi:10.1175/JCLI4254.1The Indian monsoon–El Niño–Southern Oscillation (ENSO) relationship, according to which a drier than normal monsoon season precedes peak El Niño conditions, weakened significantly during the last two decades of the twentieth century. In this work an ensemble of integrations of an atmospheric general circulation model (AGCM) coupled to an ocean model in the Indian Basin and forced with observed sea surface temperatures (SSTs) elsewhere is used to investigate the causes of such a weakening. The observed interdecadal variability of the ENSO–monsoon relationship during the period 1950–99 is realistically simulated by the model and a dominant portion of the variability is associated with changes in the tropical Atlantic SSTs in boreal summer. In correspondence to ENSO, the tropical Atlantic SSTs display negative anomalies south of the equator in the last quarter of the twentieth century and weakly positive anomalies in the previous period. Those anomalies in turn produce heating anomalies, which excite a Rossby wave response in the Indian Ocean in both the model and the reanalysis data, impacting the time-mean monsoon circulation. The proposed mechanism of remote response of the Indian rainfall to tropical Atlantic sea surface temperatures is further tested forcing the AGCM coupled to the ocean model in the Indian Basin with climatological SSTs in the Atlantic Ocean and observed anomalies elsewhere. In this second ensemble the ENSO–monsoon relationship is characterized by a stable and strong anticorrelation through the whole second half of the twentieth century.The experiments in this paper were performed as a contribution to the ENSEMBLES project funded by the European Commission’s 6th Framework Programme, Contract GOCE-CT-2003-50553

Rise and demise of the global silver standard

In the early modern period, the world economy gravitated around the expansion of long-distance commerce. Together with navigation improvements, silver was the prime commodity which moved the sails of such trade. The disparate availability and the particular demand for silver across the globe determined the participation of producers, consumers, and intermediaries in a growing global economy. American endowments of silver are a known feature of this process; however, the fact that the supply of silver was in the form of specie is a less known aspect of the integration of the global economy. This chapter surveys the production and export of silver specie out of Spanish America, its intermediation by Europeans, and the reexport to Asia. It describes how the sheer volume produced and the quality and consistency of the coin provided familiarity with, and reliability to, the Spanish American peso which made it current in most world markets. By the eighteenth century, it has become a currency standard for the international economy which grew together with the production and coinage of silver. Implications varied according to the institutional settings to deal with specie and foreign exchange in each intervening economy of that trade. Generalized warfare in late eighteenth-century Europe brought down governance in Spanish America and coinage fragmented along with the political fragmentation of the empire. The emergence of new sovereign republics and the end of minting as known meant the cessation of the silver standard that had contributed to the early modern globalization

A recipe for simulating the interannual variability of the Asian summer monsoon and its relation with ENSO

Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Climate Dynamics 28 (2007): 441-460, doi: 10.1007/s00382-006-0190-0.This study investigates how accurately the interannual variability over the Indian Ocean basin and the relationship between the Indian summer monsoon and the El Nino Southern Oscillation (ENSO) can be simulated by different modelling strategies. With a hierarchy of models, from an atmospherical general circulation model (AGCM) forced by observed SST, to a coupled model with the ocean component limited to the tropical Pacific and Indian Oceans, the role of heat fluxes and of interactive coupling is analyzed. Whenever sea surface temperature anomalies in the Indian basin are created by the coupled model, the inverse relationship between the ENSO index and the Indian summer monsoon rainfall is recovered, and it is preserved if the atmospherical model is forced by the SSTs created by the coupled model. If the ocean model domain is limited to the Indian Ocean, changes in the Walker circulation over the Pacific during El Nino years induce a decrease of rainfall over the Indian subcontinent. However the observed correlation between the ENSO and the Indian Ocean Zonal Mode (IOZM) is not properly modelled and the two indices are not significantly correlated, independently on season. Whenever the ocean domain extends to the Pacific, and ENSO can impact both the atmospheric circulation and the ocean subsurface in the equatorial Eastern Indian Ocean, modelled precipitation patterns associated both to ENSO and to the IOZM closely resemble the observations.The experiments described were performed as a contribution to the ENSEMBLES project funded by the European Commission’s 6th Framework Programme, contract number GOCE-CT-2003-505539

Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks: The GR@ACE project

INTRODUCTION: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. METHODS: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. RESULTS: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. DISCUSSION: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series

Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks : The GR@ACE project

Introduction: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. Methods: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. Results: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. Discussion: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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