105 research outputs found
How steady are steady-state mountain belts? A reexamination of the Olympic Mountains (Washington state, USA)
The Olympic Mountains of Washington state (USA) represent
the aerially exposed accretionary wedge of the Cascadia Subduction Zone and
are thought to be in flux steady state, whereby the mass outflux (denudation)
and influx (tectonic accretion) into the mountain range are balanced. We use
a multi-method approach to investigate how temporal variations in the influx
and outflux could affect previous interpretations of flux steady state. This
includes the analysis of published and new thermochronometric ages for (U–Th) ∕ He
dating of apatite and zircon (AHe and ZHe, respectively), fission-track
dating of apatite and zircon (AFT and ZFT, respectively), 1-D thermo-kinematic
modeling of thermochronometric data, and independent estimates of outflux
and influx.
In total, we present 61 new AHe, ZHe, AFT, and ZFT thermochronometric ages
from 21 new samples. AHe ages are generally young (< 4 Ma), and, in
some samples, AFT ages (5–8 Ma) overlap ZHe ages (7–9 Ma) within
uncertainties. Thermo-kinematic modeling shows that exhumation rates are
temporally variable, with rates decreasing from > 2 to
< 0.3 km Myr−1 around 5–7 Ma. With the onset of Plio–Pleistocene
glaciation, exhumation rates increased to values > 1 km Myr−1. This
demonstrates that the material outflux varies through time, requiring a
commensurate variation in influx to maintain flux steady state. Evaluation of
the offshore and onshore sediment record shows that the material influx is
also variable through time and that the amount of accreted sediment in the
wedge is spatially variable. This qualitatively suggests that significant
perturbations of steady state occur on shorter timescales (105–106 years), like those created by Plio–Pleistocene glaciation. Our quantitative
assessment of influx and outflux indicates that the Olympic Mountains could
be in flux steady state on long timescales (107Â years).</p
Was sind negative Emissionen, und warum brauchen wir sie? Akademienprojekt ‘Energiesysteme der Zukunft’ (ESYS)
Selbst mit ambitionierteren Maßnahmen zur Vermeidung von Emissionen lässt sich Klimaneutralität und damit die Stabilisierung der Temperatur nicht mehr erreichen. Darauf weist der Weltklimarat in seinem sechsten Sachstandsbericht hin. Zusätzlich zu einer schnelleren Reduktion der Emissionen muss CO2 der Atmosphäre entzogen und anschließend eingelagert werden, um nicht vermeidbare Restemissionen auszugleichen, etwa aus der Landwirtschaft. Sogenannte „negative Emissionen“ können zum Beispiel durch Aufforstung erzeugt werden. Es gibt aber eine Reihe weiterer natürlicher und technischer Verfahren, den entnommenen Kohlenstoff dauerhaft einzulagern und aus der Atmosphäre fernzuhalten. In diesem „Kurz erklärt“ skizzieren Fachleute des Akademienprojekts ESYS den aktuellen Forschungsstand, erläutern Verfahren zur CO2-Entnahme und benennen deren jeweiligen Vor- und Nachteile
Indicators for relational values of nature’s contributions to good quality of life: the IPBES approach for Europe and Central Asia
Relational values are values of desirable relationships between people and nature and among people (through nature). We report on the approach to capture relational values of nature’s contributions to people in the regional assessment for Europe and Central Asia of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). We present a framework considering indicators along four relational value dimensions about people’s relationships with nature: security and sovereignty; health; equity and justice; and heritage, social identity and stewardship. The framework has been operationalized for three nature’s contributions to people (NCP): regulation of freshwater quality and quantity, food and feed, and physical and psychological experiences derived from nature. We identify ways to empirically assess relational values of nature’s contributions to people at regional and continental scales with social-ecological indicators and proxies, ranging from biophysical indicators to indicators that intersect socio-economic with biophysical data. We conclude that many of the identified indicators can be considered as useful proxies of relational values in a quantitative way. The analysis shows that relational values are essential to consider at the science-policy interface as they are an important set of values that people hold about nature and that go beyond instrumental relations.Environmental Biolog
Bányászati és Kohászati Lapok 1876
Relational values are values of desirable relationships between people and nature and among people (through nature). We report on the approach to capture relational values of nature s contributions to people in the regional assessment for Europe and Central Asia of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). We present a framework considering indicators along four relational value dimensions about people s relationships with nature: security and sovereignty; health; equity and justice; and heritage, social identity and stewardship. The framework has been operationalized for three nature s contributions to people (NCP): regulation of freshwater quality and quantity, food and feed, and physical and psychological experiences derived from nature. We identify ways to empirically assess relational values of nature s contributions to people at regional and continental scales with social-ecological indicators and proxies, ranging from biophysical indicators to indicators that intersect socio-economic with biophysical data. We conclude that many of the identified indicators can be considered as useful proxies of relational values in a quantitative way. The analysis shows that relational values are essential to consider at the science-policy interface as they are an important set of values that people hold about nature and that go beyond instrumental relations. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor and Francis Group
GLRB allelic variation associated with agoraphobic cognitions, increased startle response and fear network activation : a potential neurogenetic pathway to panic disorder
The molecular genetics of panic disorder (PD) with and without agoraphobia (AG) are still largely unknown and progress is hampered by small sample sizes. We therefore performed a genome-wide association study with a dimensional, PD/AG - related anxiety phenotype based on the Agoraphobia Cognition Questionnaire (ACQ) in a sample of 1,370 healthy German volunteers of the CRC TRR58 MEGA study wave 1. A genome-wide significant association was found between ACQ and single non-coding nucleotide variants of the GLRB gene (rs78726293, p=3.3x10-8; rs191260602, p=3.9x10-8). We followed up on this finding in a larger dimensional ACQ sample (N=2,547) and in independent samples with a dichotomous AG phenotype based on the Symptoms Checklist (SCL-90; N=3,845) and a case control sample with the categorical phenotype PD/AG (Ncombined =1,012) obtaining highly significant p-values also for GLRB single nucleotide variants rs17035816 (p=3.8x10-4) and rs7688285 (p=7.6x10-5). GLRB gene expression was found to be modulated by rs7688285 in brain tissue as well as cell culture. Analyses of intermediate PD/AG phenotypes demonstrated increased startle reflex and increased fear network as well as general sensory activation by GLRB risk gene variants rs78726293, rs191260602, rs17035816 and rs7688285. Partial Glrb knockout-mice demonstrated an agoraphobic phenotype. In conjunction withthe clinical observation that rare coding GLRB gene mutations are associated with the neurological disorder hyperekplexia characterized by a generalized startle reaction and agoraphobic behavior, our data provide evidence that non-coding, though functional GLRB gene polymorphisms may predispose to PD by increasing startle response and agoraphobic cognitions.PostprintPeer reviewe
Characterization of transcriptional networks in blood stem and progenitor cells using high-throughput single-cell gene expression analysis
Cellular decision-making is mediated by a complex interplay of external stimuli with the intracellular environment, in particular transcription factor regulatory networks. Here we have determined the expression of a network of 18 key haematopoietic transcription factors in 597 single primary blood stem and progenitor cells isolated from mouse bone marrow. We demonstrate that different stem/progenitor populations are characterized by distinctive transcription factor expression states, and through comprehensive bioinformatic analysis reveal positively and negatively correlated transcription factor pairings, including previously unrecognized relationships between Gata2, Gfi1 and Gfi1b. Validation using transcriptional and transgenic assays confirmed direct regulatory interactions consistent with a regulatory triad in immature blood stem cells, where Gata2 may function to modulate cross-inhibition between Gfi1 and Gfi1b. Single-cell expression profiling therefore identifies network states and allows reconstruction of network hierarchies involved in controlling stem cell fate choices, and provides a blueprint for studying both normal development and human disease
An Information Theoretic, Microfluidic-Based Single Cell Analysis Permits Identification of Subpopulations among Putatively Homogeneous Stem Cells
An incomplete understanding of the nature of heterogeneity within stem cell populations remains a major impediment to the development of clinically effective cell-based therapies. Transcriptional events within a single cell are inherently stochastic and can produce tremendous variability, even among genetically identical cells. It remains unclear how mammalian cellular systems overcome this intrinsic noisiness of gene expression to produce consequential variations in function, and what impact this has on the biologic and clinical relevance of highly ‘purified’ cell subgroups. To address these questions, we have developed a novel method combining microfluidic-based single cell analysis and information theory to characterize and predict transcriptional programs across hundreds of individual cells. Using this technique, we demonstrate that multiple subpopulations exist within a well-studied and putatively homogeneous stem cell population, murine long-term hematopoietic stem cells (LT-HSCs). These subgroups are defined by nonrandom patterns that are distinguishable from noise and are consistent with known functional properties of these cells. We anticipate that this analytic framework can also be applied to other cell types to elucidate the relationship between transcriptional and phenotypic variation
Nature's contributions to people and quality of life
In this chapter, we provide an assessment of each of nature's contributions to people (NCP) and to the quality of life of societies in Europe and Central Asia. We recognize that these contributions are diverse, reflecting the multiple societies that inhabit the region and the multiple interlinked dimensions of nature and society. For that reason, the present chapter seeks to respect and to represent the multiple values of nature's contributions to people and to include the different knowledge systems that provide understanding of our relationship with nature
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