Essential pediatric hypertension: defining the educational needs of primary care pediatricians

BACKGROUND: In order to better understand the educational needs regarding appropriate recognition, diagnosis and management of pediatric hypertension (HTN), we asked practicing pediatricians questions regarding their educational needs and comfort level on this topic. METHODS: We conducted 4 focus group sessions that included 27 participants representing pediatric residents, adolescent medicine physicians, clinic based pediatricians and office based pediatricians. Each focus group session lasted for approximately an hour and 90 pages of total transcriptions were produced verbatim from audio recordings. RESULTS: Four reviewers read each transcript and themes were elucidated from these transcripts. Overall, 5 major themes related to educational needs and clinical concerns were found: utilization of resources to define blood pressure (BP), correct BP measurement method(s), co-morbidities, barriers to care, and experience level with HTN. Six minor themes were also identified: differences in BP measurement, accuracy of BP, recognition of HTN, practice pattern of care, education of families and patients, and differences in level of training. The focus group participants were also questioned on their preferences regarding educational methods (i.e. e-learning, small group sessions, self-study, large group presentations) and revealed varied teaching and learning preferences. CONCLUSIONS: There are multiple methods to approach education regarding pediatric HTN for primary care pediatricians based on provider preferences and multiple educational activities should be pursued to achieve best outcomes. Based on this data, the next direction will be to develop and deliver multiple educational methods and to evaluate the impact on practice patterns of care for children and adolescents with HTN

Stability of fermionic Feshbach molecules in a Bose-Fermi mixture

In the wake of successful experiments in Fermi condensates, experimental attention is broadening to study resonant interactions in degenerate Bose-Fermi mixtures. Here we consider the properties and stability of the fermionic molecules that can be created in such a mixture near a Feshbach resonance (FR). To do this, we consider the two-body scattering matrix in the many-body environment, and assess its complex poles. The stability properties of these molecules strongly depend on their centre-of-mass motion, because they must satisfy Fermi statistics. At low centre-of-mass momenta the molecules are more stable than in the absence of the environment (due to Pauli-blocking effects), while at high centre-of-mass momenta nontrivial many body effects render them somewhat less stable

Spin susceptibilities, spin densities and their connection to spin-currents

We calculate the frequency dependent spin susceptibilities for a two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit interaction. The resonances of the susceptibilities depends on the relative values of the Rashba and Dresselhaus spin-orbit constants, which could be manipulated by gate voltages. We derive exact continuity equations, with source terms, for the spin density and use those to connect the spin current to the spin density. In the free electron model the susceptibilities play a central role in the spin dynamics since both the spin density and the spin current are proportional to them.Comment: 6 pages, revtex4 styl

The Kondo Dynamics of YbIn(1-x)AgxCu4

We present an infrared/optical study of the dynamics of the strongly correlated electron system YbIn(1-x)AgxCu4 as a function of doping and temperature for x ranging from 0 to 1, and T between 20 and 300 K. This study reveals information about the unusual phase transition as well as the phases themselves. Scaling relations emerge from the data and are investigated in detail using a periodic Anderson model based calculation. We also provide a picture in which to view both the low and high-energy x-dependent features of the infrared data, including identification of high energy, temperature dependent features.Comment: 12 pages, 11 figures, submitted Phys. Rev.

Free energy of the Fr\"ohlich polaron in two and three dimensions

We present a novel Path Integral Monte Carlo scheme to solve the Fr\"ohlich polaron model. At intermediate and strong electron-phonon coupling, the polaron self-trapping is properly taken into account at the level of an effective action obtained by a preaveraging procedure with a retarded trial action. We compute the free energy at several couplings and temperatures in three and two dimensions. Our results show that the accuracy of the Feynman variational upper bound for the free energy is always better than 5% although the thermodynamics derived from it is not correct. Our estimates of the ground state energies demonstrate that the second cumulant correction to the variational upper bound predicts the self energy to better than 1% at intermediate and strong coupling.Comment: RevTeX 7 pages 3 figures, revised versio

Coherent Matter Wave Transport in Speckle Potentials

This article studies multiple scattering of matter waves by a disordered optical potential in two and in three dimensions. We calculate fundamental transport quantities such as the scattering mean free path $\ell_s$, the Boltzmann transport mean free path \elltrb, and the Boltzmann diffusion constant $D_B$, using a diagrammatic Green functions approach. Coherent multiple scattering induces interference corrections known as weak localization which entail a reduced diffusion constant. We derive the corresponding expressions for matter wave transport in an correlated speckle potential and provide the relevant parameter values for a possible experimental study of this coherent transport regime, including the critical crossover to the regime of strong or Anderson localization.Comment: 33 pages, minor corrections, published versio

In vivo measurement of apolipoprotein E from the brain interstitial fluid using microdialysis

BACKGROUND: The APOE4 allele variant is the strongest known genetic risk factor for developing late-onset Alzheimer’s disease. The link between apolipoprotein E (apoE) and Alzheimer’s disease is likely due in large part to the impact of apoE on the metabolism of amyloid β (Aβ) within the brain. Manipulation of apoE levels and lipidation within the brain has been proposed as a therapeutic target for the treatment of Alzheimer’s disease. However, we know little about the dynamic regulation of apoE levels and lipidation within the central nervous system. We have developed an assay to measure apoE levels in the brain interstitial fluid of awake and freely moving mice using large molecular weight cut-off microdialysis probes. RESULTS: We were able to recover apoE using microdialysis from human cerebrospinal fluid (CSF) in vitro and mouse brain parenchyma in vivo. Microdialysis probes were inserted into the hippocampus of wild-type mice and interstitial fluid was collected for 36 hours. Levels of apoE within the microdialysis samples were determined by ELISA. The levels of apoE were found to be relatively stable over 36 hours. No apoE was detected in microdialysis samples from apoE KO mice. Administration of the RXR agonist bexarotene increased ISF apoE levels while ISF Aβ levels were decreased. Extrapolation to zero-flow analysis allowed us to determine the absolute recoverable concentration of apoE3 in the brain ISF of apoE3 KI mice. Furthermore, analysis of microdialysis samples by non-denaturing gel electrophoresis determined lipidated apoE particles in microdialysis samples were consistent in size with apoE particles from CSF. Finally, we found that the concentration of apoE in the brain ISF was dependent upon apoE isoform in human apoE KI mice, following the pattern apoE2>apoE3>apoE4. CONCLUSIONS: We are able to collect lipidated apoE from the brain of awake and freely moving mice and monitor apoE levels over the course of several hours from a single mouse. Our technique enables assessment of brain apoE dynamics under physiological and pathophysiological conditions and in response to therapeutic interventions designed to affect apoE levels and lipidation within the brain

How chemistry controls electron localization in 3d1 perovskites: A Wannier-function study

In the series of 3d1 t2g perovskites, SrVO3--CaVO3--LaTiO3--YTiO3 the transition-metal d electron becomes increasingly localized and undergoes a Mott transition between CaVO3 and LaTiO3. By defining a low-energy Hubbard Hamiltonian in the basis of Wannier functions for the t2g LDA band and solving it in the single-site DMFT approximation, it was recently shown[1] that simultaneously with the Mott transition there occurs a strong suppression of orbital fluctuations due to splitting of the t2g levels. The present paper reviews and expands this work, in particular in the direction of exposing the underlying chemical mechanisms by means of ab initio LDA Wannier functions generated with the NMTO method. The Wannier functions for the t2g band exhibit covalency between the transition-metal t2g, the large cation-d, and the oxygen-p states; this covalency, which increases along the series, turns out to be responsible not only for the splittings of the t2g levels, but also for non-cubic perturbations of the hopping integrals, both of which are decisive for the Mott transition. We find good agreement with the optical and photoemission spectra, with the crystal-field splittings and orbital polarizations recently measured for the titanates, and with the metallization volume for LaTiO3. The metallization volume for YTiO3 is predicted. Using super-exchange theory, we reproduce the observed magnetic orders in LaTiO3 and YTiO3, but the results are sensitive to detail, in particular for YTiO3 which, without the Jahn-Teller distortion, would be AFM C- or A-type, rather than FM. Finally, we show that it possible to unfold the orthorhombic t2g LDA bandstructure to a pseudocubic zone. In this zone, the lowest band is separated from the two others by a direct gap and has a width, W_I, which is significantly smaller than that, W, of the entire t2g band. The progressive GdFeO3-type distortion favours electron localization by decreasing W, by increasing the splitting of the t2g levels and by decreasing W_I. Our conclusions concerning the roles of GdFeO3-type and JT distortions agree with those of Mochizuki and Imada [2].Comment: Published version, final. For high resolution figures see http://www.fkf.mpg.de/andersen/docs/pub/abstract2004+/pavarini_02.pd

The Effects of Hypertension on Cognitive Function in Children and Adolescents

Hypertension (HTN) is found in about 3-4% of the pediatric population with long-term risks of end organ damage if untreated or poorly controlled. Although children with HTN are being more frequently screened for end organ damage (i.e., LVH), the cognitive effects of HTN and methods to screen for cognitive dysfunction have not been extensively explored. In recent years, there have been a small number of studies that have provided important insights that can guide future research in this area. These studies show that HTN can be associated with headaches, restlessness, sleep disturbance, anxiety, depression, decreased attention, and also poor executive functioning. By increasing the utilization of cognitive tests in hypertensive children and adolescents, important cognitive defects secondary to HTN may be detected. More research is needed in the area, and the results of future studies could have far reaching implications for long-term outcomes in hypertensive children and adolescents