407 research outputs found
ISEE-1 data reduction and analysis plasma composition experiment
The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given
Biological Flora of Central EuropeâLupinus polyphyllus Lindl
The invasive herb Lupinus polyphyllus has been focus of a number of fact sheets worldwide but a comprehensive summary of the speciesâ taxonomy and morphology, distribution, habitat requirements, and biology has been lacking. This paper gives a thorough account of the speciesâ systematic position and taxonomy, highlighting the difficulties to delimit taxa, which is related to interbreeding among members of this genus. However, L. polyphyllus var. polyphyllus is apparently the taxon that has naturalized and is regionally invasive in temperate-humid climates worldwide. We also present an updated distribution map of L. polyphyllus in the native and invaded ranges, which highlights seven regions in the world where the species has been established. We show that the climatic niche of L. polyphyllus in the invaded range shifts towards higher summer precipitation and lower isothermality, probably because the invaded range includes subcontinental regions of eastern Europe and western Siberia. The habitats of L. polyphyllus range from rather dry to wet, have moderately acidic to strongly acidic soils, and the speciesâ indicator values across Europe suggest that it occurs along a gradient from very nutrient poor sites to intermediate to rich sites from northern to southern Europe. The species shows high resistance to both drought and frost. In Central Europe, the species has a stronghold in alpic mountain hay meadows, abandoned meadows and pastures, low and medium altitude hay meadows, anthropogenic herb stands and temperate thickets and scrubs. In northern Europe, the species occurs in anthropogenic herb stands along roads and railroads as well as in abandoned pastures and fields. We also found some doubtful information about L. polyphyllus in the literature. This refers to its description as ârhizomatous perennialâ although it lacks rhizomes; an apparently very high longevity of its seeds, which may only be true under artificial conditions in an ex situ seed repository; and a very deep rooting depth, which may not represent the average rooting depth but rather an extreme value. Knowledge about the interrelationships between the speciesâ future population dynamics and spread and ongoing climate warming is lacking. Finally, our review points out that there is currently no evidence-based strategy for a cost-efficient management of L. polyphyllus although it is among the most problematic non-native plant species in Europe due to its environmental and socio-economic impacts
Older adults experiences of rehabilitation in acute health care
Rehabilitation is a key component of nursing and allied healthcare professionalsâ roles in most health and social care settings. This paper reports on stage 2 of an action research project to ascertain older adult's experience of rehabilitation. Twenty postdischarge interviews were conducted and the interview transcripts were analysed using thematic content analysis. All older adults discharged from an acute older acute rehabilitation ward to their own homes in the community were eligible to participate. The only exclusion criterion was older adults who were thought to be unable to give consent to participate by the nurse in charge and the researcher. Whilst 92 older adults were eligible to participate in this research study, only 20 were interviewed. The findings from this study suggest that older adults valued communication with health professionals but were aware of their time constraints that hindered communication. This study suggests that both nurses and allied health professionals are not actively providing rehabilitative services to promote health and well-being, which contradicts the focus of active ageing. Furthermore, there was evidence of unmet needs on discharge, and older adults unable to recall the professions that were involved in their interventions and the rationale for therapy input. It is suggested that further research is needed to explore the effectiveness of allied health rehabilitation in the acute setting. This study highlights the need for further research into older adultsâ perceptions of the rehabilitation process in the acute setting
Induced pluripotent stem cell-derived endothelial cells promote angiogenesis and accelerate wound closure in a murine excisional wound healing model
Chronic wounds are a major complication in patients with cardiovascular diseases. Cell therapies have shown potential to stimulate wound healing, but clinical trials using adult stem cells have been tempered by limited numbers of cells and invasive procurement procedures. Induced pluripotent stem cells (iPSCs) have several advantages of other cell types, for example they can be generated in abundance from patientsâ somatic cells (autologous) or those from a matched donor. iPSCs can be efficiently differentiated to functional endothelial cells (iPSC-ECs). Here, we used a murine excisional wound model to test the pro-angiogenic properties of iPSC-ECs in wound healing. Two full-thickness wounds were made on the dorsum of NOD-SCID mice and splinted. iPSC-ECs (5 Ă 105) were topically applied to one wound, with the other serving as a control. Treatment with iPSC-ECs significantly increased wound perfusion and accelerated wound closure. Expression of endothelial cell (EC) surface marker, platelet endothelial cell adhesion molecule (PECAM-1) (CD31), and pro-angiogenic EC receptor, Tie1, mRNA was up-regulated in iPSC-EC treated wounds at 7 days post-wounding. Histological analysis of wound sections showed increased capillary density in iPSC-EC wounds at days 7 and 14 post-wounding, and increased collagen content at day 14. Anti-GFP fluorescence confirmed presence of iPSC-ECs in the wounds. Bioluminescent imaging (BLI) showed progressive decline of iPSC-ECs over time, suggesting that iPSC-ECs are acting primarily through short-term paracrine effects. These results highlight the pro-regenerative effects of iPSC-ECs and demonstrate that they are a promising potential therapy for intractable wounds.ZoĂ« E. Clayton, Richard P. Tan, Maria M. Miravet, Katarina Lennartsson, John P. Cooke, Christina A. Bursill, Steven G. Wise, Sanjay Pate
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A new source of suprathermal O+ions near the dayside polar cap boundary
A new dayside source of O+ ions for the polar magnetosphere is described, and a statistical survey presented of upward flows of O+ ions using 2 years of data from the retarding ion mass spectrometer (RIMS) experiment on board DE 1, at geocentric distances below 3 RE and invariant latitudes above 40°. The flows are classified according to their spin angle distributions. It is believed that the spacecraft potential near perigee is generally less than +2 V, in which case the entire O+ population at energies below about 60 eV is sampled. Examples are given of field-aligned flow and of transversely accelerated âcoreâ O+ ions; in the latter events a large fraction of the total O+ ion population has been transversely accelerated, and in some extreme cases all the observed ions (of all ion species) have been accelerated, and no residual cold population is observed (âtoroidalâ distributions). However, by far the most common type of O+ upflow seen by DE RIMS lies near the dayside polar cap boundary (particularly in the prenoon sector) and displays an asymmetric spin angle distribution. In such events the ions carry an upward heat flux, and strong upflow of all species is present (H+, He+, O+, O++, and N+ have all been observed with energies up to about 30 eV, but with the majority of ions below about 2 eV); hence, these have been termed upwelling ion events. The upwelling ions are embedded in larger regions of classical light ion polar wind and are persistently found under the following conditions: at geocentric distances greater than 1.4 RE; at all Kp in summer, but only at high Kp in winter. Low-energy conical ions (<30 eV) are only found near the equatorial edge of the events, the latitude of which moves equatorward with increasing Kp and is highly correlated with the location of field-aligned currents. The RIMS data are fully consistent with a âmass spectrometer effect,â whereby light ions and the more energetic O+ ions flow into the lobes and mantle and hence the far-tail plasma sheet, but lower-energy O+ is swept across the polar cap by the convection electric field, potentially acting as a source for the nightside auroral acceleration regions. The occurrence probability of upwelling ion events, as compared to those of low-altitude transversely accelerated core ions and of field-aligned flow, suggests this could be the dominant mechanism for supplying the nightside auroral acceleration region, and subsequently the ring current and near-earth plasma sheet, with ionospheric O+ ions. It is shown that the total rate of O+ outflow in upwelling ion events (greater than 10^25 s^{â1}) is sufficient for the region near the dayside polar cap boundary to be an important ionospheric heavy ion source
Epigenetic Transcriptional Regulation of the Growth Arrest-Specific gene 1 (Gas1) in Hepatic Cell Proliferation at Mononucleosomal Resolution
BACKGROUND: Gas1 (growth arrest-specific 1) gene is known to inhibit cell proliferation in a variety of models, but its possible implication in regulating quiescence in adult tissues has not been examined to date. The knowledge of how Gas1 is regulated in quiescence may contribute to understand the deregulation occurring in neoplastic diseases. METHODOLOGY/PRINCIPAL FINDINGS: Gas1 expression has been studied in quiescent murine liver and during the naturally synchronized cell proliferation after partial hepatectomy. Chromatin immunoprecipitation at nucleosomal resolution (Nuc-ChIP) has been used to carry out the study preserving the in vivo conditions. Transcription has been assessed at real time by quantifying the presence of RNA polymerase II in coding regions (RNApol-ChIP). It has been found that Gas1 is expressed not only in quiescent liver but also at the cell cycle G(1)/S transition. The latter expression peak had not been previously reported. Two nucleosomes, flanking a nucleosome-free region, are positioned close to the transcription start site. Both nucleosomes slide in going from the active to the inactive state and vice versa. Nuc-ChIP analysis of the acquisition of histone epigenetic marks show distinctive features in both active states: H3K9ac and H3K4me2 are characteristic of transcription in G(0) and H4R3me2 in G(1)/S transition. Sequential-ChIP analysis revealed that the "repressing" mark H3K9me2 colocalize with several "activating" marks at nucleosome N-1 when Gas1 is actively transcribed suggesting a greater plasticity of epigenetic marks than proposed until now. The recruitment of chromatin-remodeling or modifying complexes also displayed distinct characteristics in quiescence and the G(1)/S transition. CONCLUSIONS/SIGNIFICANCE: The finding that Gas1 is transcribed at the G(1)/S transition suggests that the gene may exert a novel function during cell proliferation. Transcription of this gene is modulated by specific "activating" and "repressing" epigenetic marks, and by chromatin remodeling and histone modifying complexes recruitment, at specific nucleosomes in Gas1 promoter
Long-term changes in lowland calcareous grassland plots using Tephroseris integrifolia subsp. integrifolia as an indicator species
Technical advance: Transcription factor, promoter, and enhancer utilization in human myeloid cells
The generation of myeloid cells from their progenitors is regulated at the level of transcription by combinatorial control of key transcription factors influencing cell-fate choice. To unravel the global dynamics of this process at the transcript level, we generated transcription profiles for 91 human cell types of myeloid origin by use of CAGE profiling. The CAGE sequencing of these samples has allowed us to investigate diverse aspects of transcription control during myelopoiesis, such as identification of novel transcription factors, miRNAs, and noncoding RNAs specific to the myeloid lineage. We further reconstructed a transcription regulatory network by clustering coexpressed transcripts and associating them with enriched cis-regulatory motifs. With the use of the bidirectional expression as a proxy for enhancers, we predicted over 2000 novel enhancers, including an enhancer 38 kb downstream of IRF8 and an intronic enhancer in the KIT gene locus. Finally, we highlighted relevance of these data to dissect transcription dynamics during progressive maturation of granulocyte precursors. A multifaceted analysis of the myeloid transcriptome is made available (www.myeloidome.roslin.ed.ac.uk). This high-quality dataset provides a powerful resource to study transcriptional regulation during myelopoiesis and to infer the likely functions of unannotated genes in human innate immunit
Genome-wide DNA methylation levels and altered cortisol stress reactivity following childhood trauma in humans
DNA methylation likely plays a role in the regulation of human stress reactivity. Here we show that in a genome-wide analysis of blood DNA methylation in 85 healthy individuals, a locus in the Kit ligand gene (KITLG; cg27512205) showed the strongest association with cortisol stress reactivity (P=5.8 ïżœ 10?6). Replication was obtained in two independent samples using either blood (N=45, P=0.001) or buccal cells (N=255, P=0.004). KITLG methylation strongly mediates the relationship between childhood trauma and cortisol stress reactivity in the discovery sample (32% mediation). Its genomic location, a CpG island shore within an H3K27ac enhancer mark, and the correlation between methylation in the blood and prefrontal cortex provide further evidence that KITLG methylation is functionally relevant for the programming of stress reactivity in the human brain. Our results extend preclinical evidence for epigenetic regulation of stress reactivity to humans and provide leads to enhance our understanding of the neurobiological pathways underlying stress vulnerability
Modeling ring current ion and electron dynamics and plasma instabilities during a highâspeed stream driven storm
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94593/1/jgra21840.pd
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