Clockwork seesaw mechanisms

We propose new mechanisms for small neutrino masses based on clockwork mechanism. The Standard Model neutrinos and lepton number violating operators communicate through the zero mode of clockwork gears, one of the two couplings of the zero mode is exponentially suppressed by clockwork mechanism. Including all known examples for the clockwork realization of the neutrino masses, different types of models are realized depending on the profile and chirality of the zero mode fermion. Each type of realization would have phenomenologically distinctive features with the accompanying heavy neutrinos.Comment: 6 pages, 4 figures, minor revision (discussion and notation improved), matches version accepted in PL

Gravity Dual of Spatially Modulated Phase

We show that the five-dimensional Maxwell theory with the Chern-Simons term is tachyonic in the presence of a constant electric field. When coupled to gravity, a sufficiently large Chern-Simons coupling causes instability of the Reissner-Nordstrom black holes in anti-de Sitter space. The instability happens only at non-vanishing momenta, suggesting a spatially modulated phase in the holographically dual quantum field theory in 3+1 dimensions, with spontaneous current generation in a helical configuration. The three-charge extremal black hole in the type IIB superstring theory on AdS_5 x S^5 barely satisfies the stability condition.Comment: 29 pages, 6 figures v2: references adde

Potential Targeting of Siglecs, Mast Cell Inhibitory Receptors, in Interstitial Cystitis

Mast cell increases and activation are detected in the chronic inflammatory bladder disease interstitial cystitis (IC), and their proinflammatory mediators are felt to contribute to regional pelvic pain and inflammatory pathophysiology. The immunoreceptor tyrosine-based inhibition motif-containing sialic acid-binding immunoglobulin-like lectins (Siglecs) expressed in mast cells could be evaluated as in vivo signaling regulators capable of inhibiting IC-related mast cell activation

Validation of Yoon's Critical Thinking Disposition Instrument

SummaryPurposeThe lack of reliable and valid evaluation tools targeting Korean nursing students' critical thinking (CT) abilities has been reported as one of the barriers to instructing and evaluating students in undergraduate programs. Yoon's Critical Thinking Disposition (YCTD) instrument was developed for Korean nursing students, but few studies have assessed its validity. This study aimed to validate the YCTD. Specifically, the YCTD was assessed to identify its cross-sectional and longitudinal measurement invariance.MethodsThis was a validation study in which a cross-sectional and longitudinal (prenursing and postnursing practicum) survey was used to validate the YCTD using 345 nursing students at three universities in Seoul, Korea. The participants' CT abilities were assessed using the YCTD before and after completing an established pediatric nursing practicum. The validity of the YCTD was estimated and then group invariance test using multigroup confirmatory factor analysis was performed to confirm the measurement compatibility of multigroups.ResultsA test of the seven-factor model showed that the YCTD demonstrated good construct validity. Multigroup confirmatory factor analysis findings for the measurement invariance suggested that this model structure demonstrated strong invariance between groups (i.e., configural, factor loading, and intercept combined) but weak invariance within a group (i.e., configural and factor loading combined).ConclusionsIn general, traditional methods for assessing instrument validity have been less than thorough. In this study, multigroup confirmatory factor analysis using cross-sectional and longitudinal measurement data allowed validation of the YCTD. This study concluded that the YCTD can be used for evaluating Korean nursing students' CT abilities

Observation of near-inertial wave reflections within the thermostad layer of an anticyclonic mesoscale eddy

Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 37 (2010): L01606, doi:10.1029/2009GL041601.Moored current observations in the southwestern East/Japan Sea of 16.5 months duration clearly captured two episodes of downward phase propagation (upward energy propagation) of near-inertial waves (NIWs). Time series of temperature and velocity from the mooring and ancillary information indicate that the mooring was located near the center of an anticyclonic eddy during these events. Considering the typical vertical structure of quasi-permanent eddy features in the region, the observed downward phase propagation appeared to occur within the seasonal thermocline and upper thermostad of the anticyclonic mesoscale eddy. Ray tracing simulation of NIW using the observed subinertial currents suggests that the upward energy propagation is caused by the reflection of the NIWs within the thermostad of the anticyclonic eddy, where the effect of the vertical shear of subinertial horizontal currents is larger than the buoyancy effect in controlling the propagation of NIWs.This work was supported by grants from the Ministry of Land, Transport, and Maritime Affairs (Ocean Climate Variability Program), and the US NSF, grant OCE-0647949 to RWS