Quasi-geostrophic dynamics in the presence of moisture gradients

The derivation of a quasi-geostrophic (QG) system from the rotating shallow water equations on a midlatitude beta-plane coupled with moisture is presented. Condensation is prescribed to occur whenever the moisture at a point exceeds a prescribed saturation value. It is seen that a slow condensation time scale is required to obtain a consistent set of equations at leading order. Further, since the advecting wind fields are geostrophic, changes in moisture (and hence, precipitation) occur only via non-divergent mechanisms. Following observations, a saturation profile with gradients in the zonal and meridional directions is prescribed. A purely meridional gradient has the effect of slowing down the dry Rossby waves, through a reduction in the "equivalent gradient" of the background potential vorticity. A large scale unstable moist mode results on the inclusion of a zonal gradient by itself, or in conjunction with a meridional moisture gradient. For gradients that are are representative of the atmosphere, the most unstable moist mode propagates zonally in the direction of increasing moisture, matures over an intraseasonal timescale and has small phase speed.Comment: 9 pages, 8 figures, Quarterly Journal of the Royal Meteorological Society, DOI:10.1002/qj.2644, 201

Blending of Cepheids in M33

A precise and accurate determination of the Hubble constant based on Cepheid variables requires proper characterization of many sources of systematic error. One of these is stellar blending, which biases the measured fluxes of Cepheids and the resulting distance estimates. We study the blending of 149 Cepheid variables in M33 by matching archival Hubble Space Telescope data with images obtained at the WIYN 3.5-m telescope, which differ by a factor of 10 in angular resolution. We find that 55+-4% of the Cepheids have no detectable nearby companions that could bias the WIYN V-band photometry, while the fraction of Cepheids affected below the 10% level is 73+-4%. The corresponding values for the I band are 60+-4% and 72+-4%, respectively. We find no statistically significant difference in blending statistics as a function of period or surface brightness. Additionally, we report all the detected companions within 2 arcseconds of the Cepheids (equivalent to 9 pc at the distance of M33) which may be used to derive empirical blending corrections for Cepheids at larger distances.Comment: v2: Fixed incorrect description of Figure 2 in text. Accepted for publication in AJ. Full data tables can be found in ASCII format as part of the source distribution. A version of the paper with higher-resolution figures can be found at http://faculty.physics.tamu.edu/lmacri/papers/chavez12.pd

Are We Practicing What We Are Taught in Health Professions’ Education? Coproducing Health Care

Health-care providers and educators are inherently empathetic, compassionate, experienced professionals who entered their profession to assure the complementary missions of public health and health care. These missions work to ensure conditions in which people can be healthy via disease and injury prevention, health promotion, and timely, effective, coordinated care (1). The skills necessary to achieve these crucial outcomes (ie, listening to the patient and their family, exhibiting empathy, and understanding the significance of the social determinants of health, etc) are routinely taught in health professions’ education. To highlight the necessity for these representative competencies covered throughout the course of health professions’ education, the personal experience of one of the author’s children is reported as a narration. The purpose of communicating this patient experience is to remind health-care providers: (a) about the importance of not only listening but hearing the parents of our patients and the patients themselves, (b) to actively practice the art and skill of empathy as the health-care setting can be overwhelming for patients and their families, and (c) to consider the impact of the social determinants of health on one’s health status to date. This 5-part patient experience serves to strengthen our commitment to assure that we practice what we are taught with the goal to coproduce health with our patients and their families

Inflationary Hubble Parameter from the Gravitational Wave Spectrum in the General Slow-roll Approximation

Improved general slow-roll formulae giving the primordial gravitational wave spectrum are derived in the present work. Also the first and second order general slow-roll inverse formulae giving the Hubble parameter $H$ in terms of the gravitational wave spectrum are derived. Moreover, the general slow-roll consistency condition relating the scalar and tensor spectra is obtained

Reading on Grade Level in Third Grade: How Is It Related to High School Performance and College Enrollment?

Illustrates how third-grade reading level correlates with eighth-grade reading level, which, along with ninth-grade school traits, correlates with ninth-grade performance, which in turn correlates with high school graduation and college attendance rates