Effect of physical activity as a moderator on the association between perceived racial discrimination and depression in African Americans

Purpose: To evaluate the relationship between perceived racial discrimination and major depressive disorder (MDD) in a sample of African Americans, and then to test if physical activity (PA) can moderate the association if such exists. Methods: This cross-sectional analysis consists of 775 African Americans (mean age= 45.3) from the Family and Community Health Study (FACHS). Perceived racial discrimination was assessed via the Schedule of Racists events, MDD was diagnosed with the University of Michigan Composite International, self-reported depression scores were assessed with the Mini-Mood and Anxiety Symptom Questionnaire, and PA was measured with two questions created by the FACHS research team. Participants were categorized into tertiles based on their discrimination scores. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of having MDD diagnosis within the past 12-months. Linear regression was also used to test the association between racial discrimination, depression, and PA. Participants were further dichotomized into low or high discrimination groups, and physically inactive or active groups to test the combined associations of discrimination and PA with MDD. Results: Discrimination was found to be positively associated with both self-reported depression in the linear regression [Standardized β= 0.15 (p=\u3c0.01)] and with MDD diagnosis in the logistic regression [OR (95% CI) 3.34 (1.26-8.81)] in the upper tertile compared to the lower tertile] after adjusting for age, education (year), sex, PA, and heavy alcohol use. A stratified analysis was conducted to test the possible effect modification by PA on the association between discrimination and MDD. Among participants who were active (meeting the PA guidelines), participants in the middle and upper categories of discrimination had no increased odds of MDD compared to the lower discrimination group. However, among participants who were inactive, odds of MDD were significantly higher for those in the upper tertile of discrimination compared to the lower tertile [(OR (95% CI) 7.24 (1.54-34.15)] after adjusting for possible confounders. Although the interaction term was not significant (p=0.18) created from racial discrimination (Lower, Middle, and Upper) and physical activity (Inactive or Active), possibly due to the very small numbers of cases in all six groups (n=2-11) with wide 95% CIs, the above result from the stratified analysis by physical activity levels clearly suggests a possible effect modification by physical activity on the association between racial discrimination and depression in this cohort of African American. However, further studies with larger sample size and more cases of depression are warranted. In the joint analysis, we observed a similar trend suggesting no increased odds of MDD in the high discrimination group if they were active. Conclusion: Perceptions of racial discrimination show a positive, linear association with MDD in African Americans, and meeting the PA guidelines may reduce the increased odds of depression due to experiencing greater levels of discrimination. However, further prospective studies are needed to confirm the findings from this cross-sectional analyses

Two--Loop Anomalous Dimension Matrix for ΔS=1\Delta S=1 Weak Non-Leptonic Decays II: O(αeαs){\cal O}(\alpha_e \alpha_s)

We calculate the $10\times 10$ two--loop anomalous dimension matrix to order \ord(\alpha_e \alpha_s) in the dimensional regularization scheme with anticommuting $\gamma_5$ (NDR) which is necessary for the extension of the $\Delta S=1$ weak Hamiltonian involving electroweak penguins beyond the leading logarithmic approximation. We demonstrate, how a direct calculation of penguin diagrams involving $\gamma_5$ in closed fermion loops can be avoided thus allowing a consistent calculation of two--loop anomalous dimensions in the simplest renormalization scheme with anticommuting $\gamma_5$ in $D$ dimensions. We give the necessary one--loop finite terms which allow to obtain the corresponding two--loop anomalous dimension matrix in the HV scheme with non--anticommuting $\gamma_5$.Comment: 25 page

An Analytic Formula and an Upper Bound for epsilon'/epsilon in the Standard Model

Using the idea of the penguin box expansion we find an analytic expression for epsilon'/epsilon in the Standard Model as a function of m_t, m_s(m_c) and two non-perturbative parameters B_6 and B_8. This formula includes next-to-leading QCD/QED short distance effects calculated recently by means of the operator product expansion and renormalization group techniques. We also derive an analytic expression for the upper bound on epsilon'/epsilon as a function of |V_cb|, |V_ub/V_cb|, B_K and other relevant parameters. Numerical examples of the bound are given.Comment: 10 pages with 1 figure appended in PostScript format; MPI preprint MPI-Ph/93-60 and TU preprint TUM-T31-47/9

Direct CP Violation in K_L --> \pi^0 e^+e^- Beyond Leading Logarithms

We analyze the direct CP violation in the rare decay K_L --> Pi^0 e+e- with QCD effects taken into account consistently in the next-to-leading order. We calculate the two-loop mixing between the four-quark \Delta S=1 operators and the operator Q_7V = (sd)_(V-A)(ee)_V in the NDR and HV renormalization schemes. Using the known two-loop anomalous dimension matrix of the four-quark operators, we find that the coefficient C_7V(\mu) depends only very weakly on \mu, renormalization scheme and \Lambda_MSbar. The next-to-leading QCD corrections enhance the direct CP violating contribution over its leading order estimate so that it remains dominant in spite of the recent decrease of |V_ub/V_cb| and |V_cb|. We expect typically BR(K_L --> \pi^0 e^+ e^-)_dir ~ 6*10^(-12), although values as high as 10^(-11) are not yet excluded.Comment: 35 pages (with 9 PostScript figures available separately), Munich Technical University preprint TUM-T31-60/94, Max-Planck Institute preprint MPI-Ph/94-1

Nanostructured Cu2_2O Synthesized via Bipolar Electrochemistry

Cuprous oxide (Cu$_2$O) was synthesized for the first time via an open bipolar electrochemistry (BPE) approach and characterized in parallel with the commercially available material. As compared to the reference, Cu$_2$O formed through a BPE reaction demonstrated a decrease in particle size; an increase in photocurrent; more efficient light scavenging; and structure-correlated changes in the flat band potential and charge carrier concentration. More importantly, as-synthesized oxides were all phase-pure, defect-free, and had an average crystallite size of 20 nm. Ultimately, this study demonstrates the impact of reaction conditions (e.g., applied potential, reaction time) on structure, morphology, surface chemistry, and photo-electrochemical activity of semiconducting oxides, and at the same time, the ability to maintain a green synthetic protocol and potentially create a scalable product. In the proposed BPE synthesis, we introduced a common food supplement (potassium gluconate) as a reducing and complexing agent, and as an electrolyte, allowing us to replace the more harmful reactants that are conventionally used in Cu$_2$O production. In addition, in the BPE process very corrosive reactants, such as hydroxides and metal precursors (required for synthesis of oxides), are generated in situ in stoichiometric quantity, providing an alternative methodology to generate various nanostructured materials in high yields under mild conditions

Solvent effects on the harvesting of stratum corneum from hairless mouse skin through adhesive tape stripping in vitro

125 [mu]l of a propylene glycol/ethanol/water vehicle were applied for various lengths of time to 1.77 cm2 area of excised hairless mouse skin sections held in in vitro diffusion cells. After removal from the cell, each skin section was stripped repeatedly with a non-hygroscopic polypropylene tape. The amount of tissue removed in each strip was determined after allowing the volatile solvents to evaporate. Weights were corrected for residual propylene glycol and water, the amounts of which were determined radioisotopically. More tissue was harvested in the first and second strips from skin conditioned with the vehicle for more than 12 h. The effect of vehicle treatment on stripping properties precludes one from determining drug and vehicle concentration gradients in the stratum corneum at different treatment times by direct comparison of corresponding strips. While it does not appear that a penetrant's deposition as a function of time can be followed easily and directly by stripping and then quantifying the drug (or solvent) in the respective layers, the stripping technique may still be useful in separating stratum corneum (or epidermis) from dermis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29469/1/0000555.pd

The Two-Loop Anomalous Dimension Matrix for ΔS=1\Delta S=1 Weak Non-Leptonic Decays I: O(αs2){\cal O}(\alpha_s^2)

We calculate the two-loop $10 \times 10$ anomalous dimension matrix ${\cal O}(\alpha_s^{2})$ involving current-current operators, QCD penguin operators, and electroweak penguin operators especially relevant for $\Delta S=1$ weak non-leptonic decays, but also important for $\Delta B=1$ decays. The calculation is performed in two schemes for $\gamma_{5}$: the dimensional regularization scheme with anticommuting $\gamma_{5}$ (NDR), and in the 't Hooft-Veltman scheme. We demonstrate how a direct calculation of diagrams involving $\gamma_{5}$ in closed fermion loops can be avoided thus allowing a consistent calculation in the NDR scheme. The compatibility of the results obtained in the two schemes considered is verified and the properties of the resulting matrices are discussed. The two-loop corrections are found to be substantial. The two-loop anomalous dimension matrix ${\cal O}(\alpha_e\alpha_s)$, required for a consistent inclusion of electroweak penguin operators, is presented in a subsequent publication.Comment: 33 page

An improved adaptive gain equalizer for noise reduction with low speech distortion

In high-quality conferencing systems, it is desired to perform noise reduction with as limited speech distortion as possible. Previous work, based on time varying amplification controlled by signal-to-noise ratio estimation in different frequency subbands, has shown promising results in this regard but can suffer from problems in situations with intense continuous speech. Further, the amount of noise reduction cannot exceed a certain level in order to avoid artifacts. This paper establishes the problems and proposes several improvements. The improved algorithm is evaluated with several different noise characteristics, and the results show that the algorithm provides even less speech distortion, better performance in a multi-speaker environment and improved noise suppression when speech is absent compared with previous work.Open Access article Article 7</p

High sensitivity of ultra-oligotrophic marine ecosystems to atmospheric nitrogen deposition

Using a model of plankton and organic-matter cycling we demonstrate that variable stoichiometric ratios can lead to a more than 5-fold higher sensitivity of simulated carbon export to atmospheric N deposition in the ultra-oligotrophic eastern part of the North Atlantic subtropical gyre compared to the westerly oligotrophic region near Bermuda, often used as a reference site for subtropical regions. Stronger nutrient limitation in the ultra-oligotrophic east causes higher phytoplankton C:N ratios and lower carbon assimilation efficiency of zooplankton in the model, which results in a higher export efficiency of carbon to the deep ocean compared to the less nutrient-limited western site. Our results indicate that previous estimates of oceanic carbon uptake associated with atmospheric nitrogen deposition may not be fully robust and that spatial variability in nutrient stress and ecological stoichiometry could significantly affect the biogeochemical impact of increasing atmospheric deposition of anthropogenic nitrogen