An observation of LHR noise with banded structure by the sounding rocket S29 Barium-GEOS

The measurement of electrostatic and obviously locally produced noise near the lower hybrid frequency made by the sounding rocket S29 Barium-GEOS is reported. The noise is strongly related to the spin of the rocket and reaches well below the local lower hybrid resonance frequency. Above the altitude of 300 km the noise shows banded structure roughly organized by the hydrogen cyclotron frequency. Simultaneously with the banded structure, a signal near the hydrogen cyclotron frequency is detected. This signal is also spin related. The characteristics of the noise suggest that it is locally generated by the rocket payload disturbing the plasma. If this interpretation is correct we expect plasma wave experiments on other spacecrafts, e.g., the space shuttle to observe similar phenomena

Conclusions from the symposium: Two decades of ART: success through research

Two decades of ART research has served as the catalyst for a new way of thinking about oral health care. It is now necessary to build on the success of ART research by educating existing and future oral health professionals and health decision makers about the benefits of the ART approach. It is also important to build upon the sound research base that already exists on ART even though enough is known about ART to consider it is a reliable and quality approach to control caries. While oral health promotion through prevention remains the essential foundation of oral health, the ART approach is an important corner stone in the building of global oral health

Access of Quaternary Ammonium Blockers to the Internal Pore of Cyclic Nucleotide-gated Channels: Implications for the Location of the Gate

Cyclic nucleotide-gated (CNG) channels play important roles in the transduction of visual and olfactory information by sensing changes in the intracellular concentration of cyclic nucleotides. We have investigated the interactions between intracellularly applied quaternary ammonium (QA) ions and the α subunit of rod cyclic nucleotide-gated channels. We have used a family of alkyl-triethylammonium derivatives in which the length of one chain is altered. These QA derivatives blocked the permeation pathway of CNG channels in a concentration- and voltage-dependent manner. For QA compounds with tails longer than six methylene groups, increasing the length of the chain resulted in higher apparent affinities of ∼1.2 RT per methylene group added, which is consistent with the presence of a hydrophobic pocket within the intracellular mouth of the channel that serves as part of the receptor binding site. At the single channel level, decyltriethyl ammonium (C10-TEA) ions did not change the unitary conductance but they did reduce the apparent mean open time, suggesting that the blocker binds to open channels. We provide four lines of evidence suggesting that QA ions can also bind to closed channels: (1) the extent of C10-TEA blockade at subsaturating [cGMP] was larger than at saturating agonist concentration, (2) under saturating concentrations of cGMP, cIMP, or cAMP, blockade levels were inversely correlated with the maximal probability of opening achieved by each agonist, (3) in the closed state, MTS reagents of comparable sizes to QA ions were able to modify V391C in the inner vestibule of the channel, and (4) in the closed state, C10-TEA was able to slow the Cd2+ inhibition observed in V391C channels. These results are in stark contrast to the well-established QA blockade mechanism in Kv channels, where these compounds can only access the inner vestibule in the open state because the gate that opens and closes the channel is located cytoplasmically with respect to the binding site of QA ions. Therefore, in the context of Kv channels, our observations suggest that the regions involved in opening and closing the permeation pathways in these two types of channels are different

Replicating the Family: The Biopolitics of Involvement Discourses Concerning Relatives in Nursing Home Institutions

The aim of this study was to describe the biopolitics of involvement discourses articulated by nursing staff concerning relatives in nursing home institutions, using a Foucault-inspired discourse analytical approach. Previous research has described how relatives have not been involved in nursing homes on their own terms. This is partly due to a lack of communication and knowledge, but it is also a consequence of an unclear organizational structure. Results from a discourse analysis of six focus group interviews with nursing staff show that the “involvement discourse” in nursing homes can be described as a “new” vs “old” family rhetoric. This rhetoric can be said to uphold, legitimize and provide different subject positions for both nursing staff and relatives concerning the conditions for involvement in nursing homes. As part of a “project of possibility” in elderly care, it may be possible to adopt a critical pedagogical approach among nursing staff in order to educate, strengthen and support them in reflecting on their professional norming and how it conditions the involvement of relatives

Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo

We have discovered a star, SDSS J090745.0+024507, leaving the Galaxy with a heliocentric radial velocity of +853+-12 km/s, the largest velocity ever observed in the Milky Way halo. The star is either a hot blue horizontal branch star or a B9 main sequence star with a heliocentric distance ~55 kpc. Corrected for the solar reflex motion and to the local standard of rest, the Galactic rest-frame velocity is +709 km/s. Because its radial velocity vector points 173.8 deg from the Galactic center, we suggest that this star is the first example of a hyper-velocity star ejected from the Galactic center as predicted by Hills and later discussed by Yu & Tremaine. The star has [Fe/H]~0, consistent with a Galactic center origin, and a travel time of <80 Myr from the Galactic center, consistent with its stellar lifetime. If the star is indeed traveling from the Galactic center, it should have a proper motion of 0.3 mas/yr observable with GAIA. Identifying additional hyper-velocity stars throughout the halo will constrain the production rate history of hyper-velocity stars at the Galactic center.Comment: 4 pages, submitted to ApJ Letter