2,144 research outputs found
Mechanisms and Observations of Coronal Dimming for the 2010 August 7 Event
Coronal dimming of extreme ultraviolet (EUV) emission has the potential to be
a useful forecaster of coronal mass ejections (CMEs). As emitting material
leaves the corona, a temporary void is left behind which can be observed in
spectral images and irradiance measurements. The velocity and mass of the CMEs
should impact the character of those observations. However, other physical
processes can confuse the observations. We describe these processes and the
expected observational signature, with special emphasis placed on the
differences. We then apply this understanding to a coronal dimming event with
an associated CME that occurred on 2010 August 7. Data from the Solar Dynamics
Observatory's (SDO) Atmospheric Imaging Assembly (AIA) and EUV Variability
Experiment (EVE) are used for observations of the dimming, while the Solar and
Heliospheric Observatory's (SOHO) Large Angle and Spectrometric Coronagraph
(LASCO) and the Solar Terrestrial Relations Observatory's (STEREO) COR1 and
COR2 are used to obtain velocity and mass estimates for the associated CME. We
develop a technique for mitigating temperature effects in coronal dimming from
full-disk irradiance measurements taken by EVE. We find that for this event,
nearly 100% of the dimming is due to mass loss in the corona
WEFES - Web explorer of forest ecosystems services under climate change
PosterClimate change will change the dynamics of forest environmental services. All the change complexity involved is difficult to visualize under an easy and accessible information tool capable to integrate several services that forests can provide.
A preliminary Web-Explorer of Forest Ecosystems Services was developed for New Zealand where forest managers and the general public can observe what are the predictions of the different forest environmental services under current and future climate for each location in the territory. Carbon storage, soil erosion, biodiversity, nitrate leaching, water balance are the preliminary forest environmental services envisaged.
The tool uses a mix of programming languages and techniques (HTML, Javascript, PHP, and Ajax) as well as the GoogleMaps© application programming interface to interact with New Zealand online-stored geographical information to supply different models´ needs. A score system is calculated for the user reference where tradeoffs can be observed by changing the climate variables in the models.
The tool (see link below) is under development and expecting “expressions of interest” for further improvement but already enabled a good interaction between different scientific background as well as interest from private forest organizations.
Tool link: http://home.isa.utl.pt/~joaopalma/projects/tranzfor/wefesTRANZFOR - SCION - ISA/UTL - MORST - FFR - FCT/MCTE
Casitas B-lineage lymphoma linker helix mutations found in myeloproliferative neoplasms affect conformation
Background: Casitas B-lineage lymphoma (Cbl or c-Cbl) is a RING ubiquitin ligase that negatively regulates protein
tyrosine kinase (PTK) signalling. Phosphorylation of a conserved residue (Tyr371) on the linker helix region (LHR)
between the substrate-binding and RING domains is required to ubiquitinate PTKs, thereby flagging them for
degradation. This conserved Tyr is a mutational hotspot in myeloproliferative neoplasms. Previous studies have
revealed that select point mutations in Tyr371 can potentiate transformation in cells and mice but not all possible
mutations do so. To trigger oncogenic potential, Cbl Tyr371 mutants must perturb the LHR-substrate-binding
domain interaction and eliminate PTK ubiquitination. Although structures of native and pTyr371-Cbl are available,
they do not reveal how Tyr371 mutations affect Cbl’s conformation. Here, we investigate how Tyr371 mutations
affect Cbl’s conformation in solution and how this relates to Cbl’s ability to potentiate transformation in cells.
Results: To explore how Tyr371 mutations affect Cbl’s properties, we used surface plasmon resonance to measure
Cbl mutant binding affinities for E2 conjugated with ubiquitin (E2–Ub), small angle X-ray scattering studies to
investigate Cbl mutant conformation in solution and focus formation assays to assay Cbl mutant transformation
potential in cells. Cbl Tyr371 mutants enhance E2–Ub binding and cause Cbl to adopt extended conformations
in solution. LHR flexibility, RING domain accessibility and transformation potential are associated with the extent
of LHR-substrate-binding domain perturbation affected by the chemical nature of the mutation. More disruptive
mutants like Cbl Y371D or Y371S are more extended and the RING domain is more accessible, whereas Cbl Y371F
mimics native Cbl in solution. Correspondingly, the only Tyr371 mutants that potentiate transformation in cells are
those that perturb the LHR-substrate-binding domain interaction.
Conclusions: c-Cbl’s LHR mutations are only oncogenic when they disrupt the native state and fail to ubiquitinate
PTKs. These findings provide new insights into how LHR mutations deregulate c-Cbl
Impact of Online Renting on Software Piracy
Online rental of software is emerging as a new way of dissemination for several major software firms. Compared to outright selling, the renting scheme delivers the software as a service instead of a physical good. Hence, users cannot privately make copies for resale in the market. We investigate the impact of the renting mechanism on software piracy and pricing in a two-period model whereby a piracy market is present in the second period. We develop and compare models with or without renting. Our analysis shows that renting reduces social welfare but helps to increase a vendor’s profit under certain conditions. We also assess the difference in outcomes in the presence of network effect
Expression of tumor necrosis factor by different tumor cell lines results either in tumor suppression or augmented metastasis
Tumor necrosis factor (TNF) produced by tumor cells after gene transfer can effectively suppress the growth of locally growing tumors. We wanted to test the effects of "local" TNF on the growth of a highly metastatic cell line. Therefore, a recombinant retrovirus allowing expression of the TNF gene by the beta-actin promotor has been constructed and used to infect the two tumor cell lines EB and ESB, which grow as solid tumor or metastasize, respectively. Expression of TNF by EB cells resulted in their rapid and dose-dependent rejection. In sharp contrast, mice injected with ESB cells producing similar amounts of TNF showed no signs of tumor suppression, but rather had reduced survival rates that correlated with enhanced hepatic metastases. The accelerated formation of liver metastases by ESB TNF cells could be reversed by an anti-TNF mAb. These results demonstrate the opposite effects TNF may have on tumor growth: suppression of a locally growing tumor and promotion of metastasis formation
Die Wirkung von FBL-Übungen während der Arbeitszeit
Treten bei vorwiegend sitzenden Tätigkeiten während der Arbeitszeit, z.B. an Bildschirmarbeitsplätzen, über kurz oder lang körperliche Beschwerden auf und kann man diese im Rahmen der betrieblichen Gesundheitsförderung beeinflussen?
Diese Frage wurde im Rahmen einer Studienarbeit , die während der Physiotherapieausbildung an der staatlichen Schule für Physiotherapie des Universitätsklinikums Münster durchgeführt wurde, untersucht. Den Probanden wurden Übungen aus der Funktionellen Bewegungslehre gezeigt, die Auswertung ergab keine unmittelbare Schmerzlinderung, aber eine Steigerung des körperlichen Wohlbefindens
A Droplet State in an Interacting Two-Dimensional Electron System
It is well known that the dielectric constant of two-dimensional (2D)
electron system goes negative at low electron densities. A consequence of the
negative dielectric constant could be the formation of the droplet state. The
droplet state is a two-phase coexistence region of high density liquid and low
density "gas". In this paper, we carry out energetic calculations to study the
stability of the droplet ground state. The possible relevance of the droplet
state to recently observed 2D metal-insulator transition is also discussed.Comment: 4 pages, 4 figures. To appear in Phys. Rev. B (Rapid Communications
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