83 research outputs found
Observations of Extreme ICME Ram Pressure Compressing Mercury's Dayside Magnetosphere to the Surface
Mercury's magnetosphere is known to be affected by enhanced ram pressures and
magnetic fields inside interplanetary coronal mass ejections (ICMEs). Here we
report detailed observations of an ICME compressing Mercury's dayside
magnetosphere to the surface. A fast CME launched from the Sun on November 29
2013 impacted first MESSENGER, which was orbiting Mercury, on November 30 and
later STEREO-A near 1 AU on December 1. Following the ICME impact, MESSENGER
remained in the solar wind as the spacecraft traveled inwards and northwards
towards Mercury's surface until it reached and passed its closest approach to
the planet (at 371 km altitude) without crossing into the magnetosphere. The
magnetospheric crossing finally occurred 1 minute before reaching the planet's
nightside at 400 km altitude and 84N latitude, indicating the lack of
dayside magnetosphere on this orbit. In addition, the peak magnetic field
measured by MESSENGER at this time was 40% above the values measured in the
orbits just prior to and after the ICME, a consequence of the magnetospheric
compression. Using both a proxy method at Mercury and measurements at STEREO-A,
we show that the extremely high ram pressure associated with this ICME was more
than high enough to collapse Mercury's weak magnetosphere. As a consequence,
the ICME plasma likely interacted with Mercury's surface, evidenced by enhanced
sodium ions in the exosphere. The collapse of Mercury's dayside magnetosphere
has important implications for the habitability of close-in exoplanets around M
dwarf stars, as such events may significantly contribute to planetary
atmospheric loss in these systems
Longitudinal conjunction between MESSENGER and STEREO A: Development of ICME complexity through stream interactions
We use data on an interplanetary coronal mass ejection (ICME) seen by MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) and STEREO A starting on 29 December 2011 in a near‐perfect longitudinal conjunction (within 3°) to illustrate changes in its structure via interaction with the solar wind in less than 0.6 AU. From force‐free field modeling we infer that the orientation of the underlying flux rope has undergone a rotation of ∼80° in latitude and ∼65° in longitude. Based on both spacecraft measurements as well as ENLIL model simulations of the steady state solar wind, we find that interaction involving magnetic reconnection with corotating structures in the solar wind dramatically alters the ICME magnetic field. In particular, we observed a highly turbulent region with distinct properties within the flux rope at STEREO A, not observed at MESSENGER, which we attribute to interaction between the ICME and a heliospheric plasma sheet/current sheet during propagation. Our case study is a concrete example of a sequence of events that can increase the complexity of ICMEs with heliocentric distance even in the inner heliosphere. The results highlight the need for large‐scale statistical studies of ICME events observed in conjunction at different heliocentric distances to determine how frequently significant changes in flux rope orientation occur during propagation. These results also have significant implications for space weather forecasting and should serve as a caution on using very distant observations to predict the geoeffectiveness of large interplanetary transients.Key PointsICME complexity increases due to interaction with corotating structures in the solar windMagnetic reconnection between ICME and HPS/HCS alters the magnetic topology of the ICME flux ropeCaution on using distant observations to predict the geoeffectiveness of interplanetary transientsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134123/1/jgra52739.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134123/2/jgra52739_am.pd
The Complex Rupture Process of the 1996 Deep Flores, Indonesia Earthquake (M w 7.9) from teleseismic P‐waves
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95103/1/grl10185.pd
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A combinatorial extracellular matrix platform identifies cell-extracellular matrix interactions that correlate with metastasis
Extracellular matrix interactions play essential roles in normal physiology and many pathological processes. While the importance of ECM interactions in metastasis is well documented, systematic approaches to identify their roles in distinct stages of tumorigenesis have not been described. Here we report a novel screening platform capable of measuring phenotypic responses to combinations of ECM molecules. Using a genetic mouse model of lung adenocarcinoma, we measure the ECM-dependent adhesion of tumor-derived cells. Hierarchical clustering of the adhesion profiles differentiates metastatic cell lines from primary tumor lines. Furthermore, we uncovered that metastatic cells selectively associate with fibronectin when in combination with galectin-3, galectin-8, or laminin. We show that these molecules correlate with human disease and that their interactions are mediated in part by α3β1 integrin. Thus, our platform allowed us to interrogate interactions between metastatic cells and their microenvironments, and identified ECM and integrin interactions that could serve as therapeutic targets
The impact of failure to achieve symptom control after resection of functional neuroendocrine tumors: An 8â institution study from the US Neuroendocrine Tumor Study Group
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147162/1/jso25306_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147162/2/jso25306.pd
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Mixing Interstellar Clouds Surrounding the Sun
On its journey through the Galaxy, the Sun passes through diverse regions of the interstellar medium. High-resolution spectroscopic measurements of interstellar absorption lines in spectra of nearby stars show absorption components from more than a dozen warm partially ionized clouds within 15 pc of the Sun. The two nearest clouds—the Local Interstellar Cloud (LIC) and Galactic (G) cloud—move toward each other. Their bulk heliocentric velocities can be compared with the interstellar neutral helium flow velocity obtained from space-based experiments. We combine recent results from Ulysses, IBEX, and STEREO observations to find a more accurate estimate of the velocity and temperature of the very local interstellar medium. We find that, contrary to the widespread viewpoint that the Sun resides inside the LIC, the locally observed velocity of the interstellar neutral helium is consistent with a linear combination of the velocities of the LIC and G cloud, but not with either of these two velocities. This finding shows that the Sun travels through a mixed-cloud interstellar medium composed of material from both these clouds. Interactions between these clouds explain the substantially higher density of the interstellar hydrogen near the Sun and toward stars located within the interaction region of these two clouds. The observed asymmetry of the interstellar helium distribution function also supports this interaction. The structure and equilibrium in this region require further studies using in situ and telescopic observations.
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Mycobacterium tuberculosis promotes Th17 expansion via regulation of human dendritic cells toward a high CD14 and low IL-12p70 phenotype that reprograms upon exogenous IFN-γ.
Item does not contain fulltextThe capacity to develop protective immunity against mycobacteria is heterogeneously distributed among human beings, and it is currently unknown why the initial immune response induced against Mycobacterium tuberculosis (Mtb) does not provide proper clearance of this pathogen. Dendritic cells (DCs) are some of the first cells to interact with Mtb and they play an essential role in development of protective immunity against Mtb. Given that Mtb-infected macrophages have difficulties in degrading Mtb, they need help from IFN-gamma-producing CD4+ T cells propagated via IL-12p70-producing DCs. Here we report that Mtb modifies human DC plasticity by expanding a CD14+ DC subset with weak IL-12p70-producing capacity. The CD14+ Mtb-promoted subset was furthermore poor inducers of IFN-gamma by naive CD4+ T cells, but instead prompted IL-17A-producing RORgammaT+ CD4+ T cells. Mtb-derived peptidoglycan and mannosylated lipoarabinomannan partly recapitulated the subset partition induced by Mtb. Addition of IFN-gamma, but neither IL-17A nor IL-22, which are potentially produced by Mtb-exposed gamma/delta-T cells in mucosal linings, inhibited the differentiation toward CD14+ DCs and promoted high-level IL-12p70 in Mtb-challenged DCs. We conclude that Mtb exploits DC plasticity to reduce production of IL-12p70, and that this process is entirely divertible by exogenous IFN-gamma. These data suggest that strategies to increase local IFN-gamma production in the lungs of tuberculosis patients may boost host immunity toward Mtb
Qualitative data sharing and re-use for socio-environmental systems research: A synthesis of opportunities, challenges, resources and approaches
Researchers in many disciplines, both social and natural sciences, have a long history of collecting and analyzing qualitative data to answer questions that have many dimensions, to interpret other research findings, and to characterize processes that are not easily quantified. Qualitative data is increasingly being used in socio-environmental systems research and related interdisciplinary efforts to address complex sustainability challenges. There are many scientific, descriptive and material benefits to be gained from sharing and re-using qualitative data, some of which reflect the broader push toward open science, and some of which are unique to qualitative research traditions. However, although open data availability is increasingly becoming an expectation in many fields and methodological approaches that work on socio-environmental topics, there remain many challenges associated the sharing and re-use of qualitative data in particular.
This white paper discusses opportunities, challenges, resources and approaches for qualitative data sharing and re-use for socio-environmental research. The content and findings of the paper are a synthesis and extension of discussions that began during a workshop funded by the National Socio-Environmental Synthesis Center (SESYNC) and held at the Center Feb. 28-March 2, 2017. The structure of the paper reflects the starting point for the workshop, which focused on opportunities, challenges and resources for qualitative data sharing, and presents as well the workshop outputs focused on developing a novel approach to qualitative data sharing considerations and creating recommendations for how a variety of actors can further support and facilitate qualitative data sharing and re-use.
The white paper is organized into five sections to address the following objectives:
(1) Define qualitative data and discuss the benefits of sharing it along with its role in socio-environmental synthesis;
(2) Review the practical, epistemological, and ethical challenges regarding sharing such data;
(3) Identify the landscape of resources available for sharing qualitative data including repositories and communities of practice
(4) Develop a novel framework for identifying levels of processing and access to qualitative data; and
(5) Suggest roles and responsibilities for key actors in the research ecosystem that can improve the longevity and use of qualitative data in the future.This work was supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1052875
Hair Cortisol in Twins : Heritability and Genetic Overlap with Psychological Variables and Stress-System Genes
A. Palotie on työryhmän jäsen.Hair cortisol concentration (HCC) is a promising measure of long-term hypothalamus-pituitary-adrenal (HPA) axis activity. Previous research has suggested an association between HCC and psychological variables, and initial studies of inter-individual variance in HCC have implicated genetic factors. However, whether HCC and psychological variables share genetic risk factors remains unclear. The aims of the present twin study were to: (i) assess the heritability of HCC; (ii) estimate the phenotypic and genetic correlation between HPA axis activity and the psychological variables perceived stress, depressive symptoms, and neuroticism; using formal genetic twin models and molecular genetic methods, i.e. polygenic risk scores (PRS). HCC was measured in 671 adolescents and young adults. These included 115 monozygotic and 183 dizygotic twin-pairs. For 432 subjects PRS scores for plasma cortisol, major depression, and neuroticism were calculated using data from large genome wide association studies. The twin model revealed a heritability for HCC of 72%. No significant phenotypic or genetic correlation was found between HCC and the three psychological variables of interest. PRS did not explain variance in HCC. The present data suggest that HCC is highly heritable. However, the data do not support a strong biological link between HCC and any of the investigated psychological variables.Peer reviewe
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