Effects of Wind Field Inhomogeneities on Doppler Beam Swinging Revealed by an Imaging Radar

In this work, the accuracy of the Doppler beam-swinging (DBS) technique for wind measurements is studied using an imaging radar—the turbulent eddy profiler (TEP) developed by the University of Mas- sachusetts, with data collected in summer 2003. With up to 64 independent receivers, and using coherent radar imaging (CRI), several hundred partially independent beams can be formed simultaneously within the volume defined by the transmit beam. By selecting a subset of these beams, an unprecedented number of DBS configurations with varying zenith angle, azimuth angle, and number of beams can be investigated. The angular distributions of echo power and radial velocity obtained by CRI provide a unique opportunity to validate the inherent assumption in the DBS method of homogeneity across the region defined by the beam directions. Through comparison with a reference wind field, calculated as the optimal uniform wind field derived from all CRI beams with sufficient signal-to-noise ratio (SNR), the accuracy of the wind estimates for various DBS configurations is statistically analyzed. It is shown that for a three-beam DBS configura- tion, although the validity of the homogeneity assumption is enhanced at smaller zenith angles, the root- mean-square (RMS) error increases because of the ill-conditioned matrix in the DBS algorithm. As ex- pected, inhomogeneities in the wind field produce large bias for the three-beam DBS configuration for large zenith angles. An optimal zenith angle, in terms of RMS error, of approximately 9°–10° was estimated. It is further shown that RMS error can be significantly reduced by increasing the number of off-vertical beams used for the DBS processing

Exact quantum states of a general time-dependent quadratic system from classical action

A generalization of driven harmonic oscillator with time-dependent mass and frequency, by adding total time-derivative terms to the Lagrangian, is considered. The generalization which gives a general quadratic Hamiltonian system does not change the classical equation of motion. Based on the observation by Feynman and Hibbs, the propagators (kernels) of the systems are calculated from the classical action, in terms of solutions of the classical equation of motion: two homogeneous and one particular solutions. The kernels are then used to find wave functions which satisfy the Schr\"{o}dinger equation. One of the wave functions is shown to be that of a Gaussian pure state. In every case considered, we prove that the kernel does not depend on the way of choosing the classical solutions, while the wave functions depend on the choice. The generalization which gives a rather complicated quadratic Hamiltonian is simply interpreted as acting an unitary transformation to the driven harmonic oscillator system in the Hamiltonian formulation.Comment: Submitted to Phys. Rev.

Psychosocial Factors of Physical Activity among People with Disabilities: Prospective Cohort Study

Purpose/objective: This study aimed to 1) explore the associations between psychosocial factors and physical activity behavior in people with physical disabilities and/or chronic diseases, both between and within persons over time; and 2) examine whether these associations differ for people initiating and people maintaining physical activity behavior.Research methods/design: Data of 1256 adults with physical disabilities and/or chronic diseases enrolled in the prospective cohort study Rehabilitation, Sports and Active lifestyle (ReSpAct) were analyzed. Self-reported physical activity and four main psychosocial factors (i.e. self-efficacy, attitude, motivation, social support) were measured with questionnaires 3-6 weeks before discharge (T0) and 14 (T1), 33 (T2) and 52 (T3) weeks after discharge from rehabilitation. Hybrid multilevel regression models (corrected for age, sex, education level, diagnosis, counseling support) were used.Results: Multivariable significant between-subject associations were found for self-efficacy (β=.094 17 95%CI .035 – .153) and intrinsic motivation (β=.114 95%CI .036 – .192). Multivariable significant within-subject associations were found for identified regulation (β=-.038 95%CI -.072 – -.005) and intrinsic motivation (β=.049 95%CI .016 – .082). Effect modification of initiating or maintaining physical activity was found for the between-subject association of attitude (p=.035). No significant associations were found for social support, amotivation, external regulation and introjected regulation.Conclusion/implications: This study is the first that explored the between- and within-subject associations between psychosocial factors and physical activity over time in a large cohort of adults with physical disabilities and/or chronic diseases. The findings indicate the importance of intrinsic motivation, identified regulation and self-efficacy in initiating and maintaining physical activity behavior

Cohesin mutations alter DNA damage repair and chromatin structure and create therapeutic vulnerabilities in MDS/AML

The cohesin complex plays an essential role in chromosome maintenance and transcriptional regulation. Recurrent somatic mutations in the cohesin complex are frequent genetic drivers in cancer including myelodysplatic syndromes (MDS) and acute myeloid leukemia (AML). Here, using genetic dependency screens of STAG2-mutant AML, we identified DNA damage repair and replication as genetic dependencies in cohesin-mutant cells. We demonstrated increased levels of DNA damage and sensitivity of cohesin-mutant cells to PARP inhibition. We developed a mouse model of MDS in which Stag2 mutations arise as clonal secondary lesions in the background of clonal hematopoiesis driven by Tet2 mutations, and demonstrated selective depletion of cohesin-mutant cells with PARP inhibition in vivo. Finally, we demonstrated a shift from STAG2- to STAG1-containing cohesin complexes in cohesin-mutant cells, which is associated with longer DNA loop extrusion, more intermixing of chromatin compartments, and increased interaction with PARP and RPA proteins. Our findings inform the biology and therapeutic opportunities for cohesin-mutant malignancies

Psychosocial development in survivors of childhood differentiated thyroid carcinoma: A cross-sectional study

Objective: The impact of childhood differentiated thyroid carcinoma (DTC) on psychosocial development has not yet been studied. The aim of this study was to evaluate the achievement of psychosocial developmental milestones in long-term survivors of childhood DTC. Design and methods: Survivors of childhood DTC diagnosed between 1970 and 2013 were included. Reasons for exclusion were age 35 years at follow-up, a follow-up period <5 years or diagnosis with DTC as a second malignant neoplasm. Survivors gathered peer controls of similar age and sex (n=30

Use of Salivary Iodine Concentrations to Estimate the Iodine Status of Adults in Clinical Practice

Background: Measurement of the 24-h urinary iodine concentration or urinary iodine excretion (UIE) is the gold standard to determine iodine status; however, this method is inconvenient. The use of salivary iodine could be a possible alternative since salivary glands express the sodium-iodine symporter.Objectives: We aimed to establish the correlation between the salivary iodine secretion and UIE, to evaluate the clinical applicability of the iodine saliva measurement.Methods: We collected 24-h urine and saliva samples from 40 participants >= 18 y: 20 healthy volunteers with no specific diet (group 1), 10 patients with differentiated thyroid cancer with a low dietary intake (<50 mu g/d, group 2), and 10 patients with a high iodine status as the result of the use of amiodarone (group 3). Urinary and salivary iodine were measured using a validated inductively coupled plasma MS method. To correct for differences in water content, the salivary iodine concentration (SIC) was corrected for salivary protein and urea concentrations (SI/SP and SI/SU, respectively). The intra-and inter-individual CVs were calculated, and the Kruskal-Wallis test and Spearman's correlation were used.Results: The intra-individual CVs for SIC, SI/SP and SI/SU were 63.8%, 37.7%, and 26.9%, respectively. The inter-individual CVs for SIC, SI/SP and SI/SU were 775%, 41.6% and 470%, respectively. We found significant differences (P < 0.01) in urinary and salivary iodine concentrations between all groups [the 24-h UIE values were 176 mu g/d (IQR, 96.1-213 mu g/d), 26.0 mu g/d (IQR, 22.0-37.0 mu g/d), and 10.0*10(3) mu g/d (IQR, 757*10(3)-11.4*10(3) mu g/d) in groups 1-3, respectively; the SIC values were 136 mu g/L (IQR, 86.3-308 mu g/L), 71.5 tg/L (IQR, 29.5-94.5 mu g/L), and 14.3*10(3) mu g/L (IQR, 10.6*10(3) 25.6*10(3) mu g/L) in groups 1-3, respectively]. Correlations between the 24-h UIE and SIC, sysp and SI/SU values were strong (rho = 0.80, rho = 0.90, and rho = 0.86, respectively; P < 0.01).Conclusions: Strong correlations were found between salivary and urinary iodine in adults with different daily iodine intakes. A salivary iodine measurement can be performed to assess the total iodine body pool, with the recommendation to correct for salivary protein or urea