On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region

This study is based on measurements of trapped and precipitated electrons of energy &gt;30 keV and &gt;100 keV observed by polar orbiting environmental satellites during overpasses of the imaging riometer at Kilpisjärvi, Finland. The satellites are in sun-synchronous orbits of about 850 km altitude, recording the electron fluxes at 2-s time resolution. The riometer measures the radiowave absorption at 38.2 MHz, showing the spatial pattern within a 240 km field of view. <br><br> The analysis has focussed on two areas. Having found a close correlation between the radiowave absorption and the medium-energy electron fluxes during satellite overpasses, empirical relationships are derived, enabling one quantity to be predicted from the other for three sectors of local time. It is shown that small-scale variations observed during a pass are essentially spatial rather than temporal. <br><br> Other properties, such as the spectra and the relation between precipitated and trapped components, are also considered in the light of the theory of pitch angle scattering by VLF waves. It is found that the properties and behaviour depend strongly on the time of day. In the noon sector, the precipitated and trapped fluxes are highly correlated through a square law relationship

Effects of chlorpyrifos and chlorpyrifos-methyl on the outgrowth of axon-like processes, tubulin, and GAP-43 in N2a cells

The aim of this work was to study the neurodegenerative effects of the organophosphate (OP) pesticides chlorpyrifos (CPF) and chlorpyrifos-methyl (CHM) on cultured mouse N2a neuroblastoma cells. CPF or CHM, at a subcytotoxic concentration of 3 μM, were added to the cells either at the time of the induction of cell differentiation (codifferentiation) or 16 h after the induction of differentiation (postdifferentiation). CPF and CHM were similar in inhibiting significantly the outgrowth of axon-like processes from N2a cells after only 4 h exposure under both co- and postdifferentiation exposure conditions. Densitometric scanning of Western blots of extracts of cells treated with CPF or CHM for 4 h revealed significantly decreased cross-reactivity with a monoclonal antibody recognizing the protein GAP-43 under post- but not under codifferentiation exposure conditions. Exposure to CPF or CHM for 4 h under postdifferentiation conditions also resulted in reduced fluorescence of N2a cell body staining with anti-GAP-43. Cross-reactivity of Western blots with a monoclonal antibody recognizing -tubulin was not significantly affected by OP treatment. These data indicate that a disturbance in GAP-43 may be important in the retraction of axons in predifferentiated N2a cells and support the notion that the mechanisms involved in CPF-and CHM-induced inhibition of axonal outgrowth may be different under co- and postdifferentiation exposure conditions

The denitridation of nitrides of iron, cobalt and rhenium under hydrogen

The denitridation behaviour of binary iron, cobalt and rehnium nitrides under H2 /Ar has been investigated. The iron nitride was found to lose over 70 % of its as prepared nitrogen content at 400 °C. The cobalt nitride was completely denitrided at 250 °C. Rhenium nitride lost close to 90 % of its nitrogen at 350 °C. In addition, Co-Re4 prepared by ammonolyis was investigated, whilst only traces of NH&lt;sub&gt;3&lt;/sub&gt; were lost from this material under H&lt;sub&gt;2&lt;/sub&gt;/Ar at 400 °C, with H&lt;sub&gt;2&lt;/sub&gt;/N2 it proved to be an active ambient pressure ammonia synthesis catalyst in accordance with previous literature

Hot methane line lists for exoplanet and brown dwarf atmospheres

We present comprehensive experimental line lists of methane (CH4) at high temperatures obtained by recording Fourier transform infrared emission spectra. Calibrated line lists are presented for the temperatures 300 - 1400 degC at twelve 100 degC intervals spanning the 960 - 5000 cm-1 (2.0 - 10.4 microns) region of the infrared. This range encompasses the dyad, pentad and octad regions, i.e., all fundamental vibrational modes along with a number of combination, overtone and hot bands. Using our CH4 spectra, we have estimated empirical lower state energies (Elow in cm-1) and our values have been incorporated into the line lists along with line positions (cm-1) and calibrated line intensities (S' in cm molecule-1). We expect our hot CH4 line lists to find direct application in the modeling of planetary atmospheres and brown dwarfs.Comment: Supplementary material is provided via the Astrophysical Journal referenc

Characterisation of Truncated Mutant Rhodopsin and its Involvement in the Pathogenesis of Retinitis Pigmentosa

Autosomal dominant retinitis pigmentosa (ADRP) is the most common genetic disorders which cause visual degradation, and blindness. 20-25% of cases are caused by mutations in the rhodopsin gene. The mutations located in the N-terminus of rhodopsin produce severely misfolded protein, which has been shown to cleave at the N-terminus removing the glycosylation sites(Tam & Moritz, 2007),(Krebs, et al., 2010). We aimed to further understand the pathology of retinitis pigmentosa by separating full rhodopsin from the truncated rhodopsin of the mutant, and we constructed rhodopsin N-terminus ADRP mutations: T4K, P23A/H and Q28H. Wild Type and mutant rhodopsin were purified using 1D4-sepharose separation. Our results supported papers indicating P23A and T4K show lowest degrees of misfolding. Assuming the glycosylation sites are removed we attempted to isolate the truncated species of the ADRP mutant by Con A-Sepharose which binds to the glycan moieties extended from the glycosylation sites N2 and N15(De Grip, W. J.,1982).We isolated purified ROS rhodopsin and full P23A rhodopsin. We failed to isolate the P23A truncated species, and poor binding was apparent from full rhodopsin in the wash and flow through after binding. Meaning the truncated species if present would not have been isolated. Further alterations are needed to make the Con A-sepharose separation successful

myTrustedCloud: Trusted cloud infrastructure for security-critical computation and data managment

Copyright @ 2012 IEEECloud Computing provides an optimal infrastructure to utilise and share both computational and data resources whilst allowing a pay-per-use model, useful to cost-effectively manage hardware investment or to maximise its utilisation. Cloud Computing also offers transitory access to scalable amounts of computational resources, something that is particularly important due to the time and financial constraints of many user communities. The growing number of communities that are adopting large public cloud resources such as Amazon Web Services [1] or Microsoft Azure [2] proves the success and hence usefulness of the Cloud Computing paradigm. Nonetheless, the typical use cases for public clouds involve non-business critical applications, particularly where issues around security of utilization of applications or deposited data within shared public services are binding requisites. In this paper, a use case is presented illustrating how the integration of Trusted Computing technologies into an available cloud infrastructure - Eucalyptus - allows the security-critical energy industry to exploit the flexibility and potential economical benefits of the Cloud Computing paradigm for their business-critical applications

The estimation of D-region electron densities from riometer data

International audienceAt high latitude the hard electron precipitation associated with auroral activity is a major source of ionization for the D-region, one consequence being the absorption of radio waves. Direct measurements of the D-region electron density are not readily available, however. This paper investigates the relationship between the electron density at altitudes between 100 and 70 km and the total radio absorption observed with a riometer, with a view to using the latter to predict the former. Tables are given of the median electron density corresponding to 1 dB absorption at 27.6 MHz for each hour of the day, and it is shown that at certain heights the estimates will be accurate to within a factor of 1.6 on 50% of the occasions. A systematic variation with time of day is probably associated with a progressive hardening of the typical electron spectrum during the morning hours. There is also evidence for a seasonal effect possibly due to seasonal variations of the mesosphere