Anomalous effect of carriers on dielectric constant of (In,Ga)(As,P) lasers operating at 1.3 ?m wavelength

Injected carriers were found to reduce the dielectric constant of the active layer by the unexpectedly high value of 0.4. This is a factor of approximately four greater than measured for GaAs/(Ga, Al)As lasers and also higher than other reported values for (In,Ga)(As,P) lasers operating at a wavelength of 1.6 ?m. The technique employed was the observation of the spectral shift of individual Fabry-Perot modes of oxide insulated stripe lasers down to very low currents below threshold.     

Consumption and Metabolism of 1,2-Dimethoxy-4-(3-Fluoro-2-Propenyl)Benzene, a Fluorine Analog of Methyl Eugenol, in the Oriental Fruit Fly Bactrocera dorsalis (Hendel)

Methyl eugenol (ME) is a natural phenylpropanoid highly attractive to oriental fruit fly Bactrocera dorsalis (Hendel) males. The flies eagerly feed on ME and produce hydroxylated metabolites with both pheromonal and allomonal functions. Side-chain metabolic activation of ME has long been recognized as a primary reason for hepatocarcinogenicity of this compound on rodents. In an attempt to develop a safer alternative to ME for fruit fly management, we developed a fluorine analog 1,2-dimethoxy-4-(3-fluoro-2-propenyl)benzene (I), which, in earlier field tests, was as active to the oriental fruit fly as ME. Now we report that B. dorsalis males are not only attracted to, but also eagerly consume (up to ∼1 mg/insect) compound I, thus recognizing this fluorinated benzene as a close kin of the natural ME. The flies metabolized the fluorine analog I in a similar fashion producing mostly two hydroxylated products, 2-(3-fluoro-2-propenyl)-4,5-dimethoxyphenol (II) and (E)-coniferyl alcohol (III), which they stored in rectal glands. However, the introduction of the fluorine atom at the terminal carbon atom of the double bond favors the ring hydroxylation over a side-chain metabolic oxidation pathway, by which coniferyl alcohol is produced. It also appears that fluorination overall impedes the metabolism: at high feed rate (10 μl per 10 males), the flies consumed in total more fluorine analog I than ME but were unable to metabolize it as efficiently as ME.     

Ring-Fluorinated Analog of Methyl Eugenol: Attractiveness to and Metabolism in the Oriental Fruit Fly, <Emphasis Type="Italic">Bactrocera Dorsalis</Emphasis> (Hendel)

Oriental fruit fly, Bactrocera dorsalis (Hendel), males are highly attracted to the natural phenylpropanoid methyl eugenol (ME). They compulsively feed on ME and metabolize it to ring and side-chain hydroxylated compounds that have both pheromonal and allomonal functions. Side-chain metabolic activation of ME leading to (E)-coniferyl alcohol has long been recognized as a primary reason for hepatocarcinogenicity of this compound in rodents. Earlier, we demonstrated that introduction of a fluorine atom at the terminal carbon of the ME side chain significantly depressed metabolism and specifically reduced formation of coniferyl alcohol but had little effect on field attractiveness to B. dorsalis. In the current paper, we demonstrate that fluorination of ME at the 4 position of the aromatic ring blocks metabolic ring-hydroxylation but overall enhances side-chain metabolism by increasing production of fluorinated (E)-coniferyl alcohol. In laboratory experiments, oriental fruit fly males were attracted to and readily consumed 1,2-dimethoxy-4-fluoro-5-(2-propenyl)benzene (I) at rates similar to ME but metabolized it faster. Flies that consumed the fluorine analog were as healthy post feeding as ones fed on methyl eugenol. In field trials, the fluorine analog I was ∼50% less attractive to male B. dorsalis than ME.

Efficient Synthesis of Highly Active Phospha‐Isosteres of the Influenza Neuraminidase Inhibitor Oseltamivir

With a Hunsdiecker–Barton iododecarboxylation strategy, we converted the carboxylate group of the oseltamivir precursor into exemplary phosphonate monoesters. In all cases, K_i values towards influenza virus sialidase remained in the sub‐nanomolar range. We have thus made valuable structural space available for the design of novel oseltamivir‐based tools for influenza virus research.

     

Development and validation of a quantitative choline food frequency questionnaire for use with drinking and non-drinking pregnant women in Cape Town,South Africa

Background

Although animal and human studies have demonstrated interactions between dietary choline and fetal alcohol spectrum disorders, dietary choline deficiency in pregnancy is common in the US and worldwide. We sought to develop and validate a quantitative food frequency questionnaire (QFFQ) to estimate usual daily choline intake in pregnant mothers.

Methods

A panel of nutrition experts developed a Choline-QFFQ food item list, including sources with high choline content and the most commonly consumed choline-containing foods in the target population. A data base for choline content of each item was compiled. For reliability and validity testing in a prospective longitudinal cohort, 123 heavy drinking Cape Coloured pregnant women and 83 abstaining/light-drinking controls were recruited at their first antenatal clinic visit. At 3 prenatal study visits, each gravida was interviewed about alcohol, smoking, and drug use, and administered a 24-hour recall interview and the Choline-QFFQ.

Results

Across all visits and assessments, > 78% of heavy drinkers and controls reported choline intake below the Dietary Reference Intakes adequate intake level (450 mg/day). Women reported a decrease in choline intake over time on the QFFQ. Reliability of the QFFQ across visits was good-to-acceptable for 2 of 4 group-level tests and 4 of 5 individual-level tests for both drinkers and controls. When compared with 24-hr recall data, validity of the QFFQ was good-to-acceptable for 3 of 4 individual-level tests and 3 of 5 group-level tests. For controls, validity was good-to-acceptable for all 4 individual-level tests and all 5 group-level tests.

Conclusions

To our knowledge, this is the first quantitative choline food frequency screening questionnaire to be developed and validated for use with both heavy and non-drinking pregnant women and the first to be used in the Cape Coloured community in South Africa. Given the high prevalence of inadequate choline intake and the growing evidence that maternal choline supplementation can mitigate some of the adverse effects of prenatal alcohol exposure, this tool may be useful for both research and future clinical outreach programs.

     

Identification of Correlative Shifts in Indices of Brain Cholesterol Metabolism in the C57BL6/Mecp2tm1.1Bird Mouse,a Model for Rett Syndrome

Rett syndrome (RS) is a pervasive neurodevelopmental disorder resulting from loss‐of‐function mutations in the X‐linked gene methyl‐Cpg‐binding protein 2 (MECP2). Using a well‐defined model for RS, the C57BL6/Mecp2^tm1.1Bird mouse, we have previously found a moderate but persistently lower rate of cholesterol synthesis, measured in vivo, in the brains of Mecp2^?/y mice, starting from about the third week after birth. There was no genotypic difference in the total cholesterol concentration throughout the brain at any age. This raised the question of whether the lower rate of cholesterol synthesis in the mutants was balanced by a fall in the rate at which cholesterol was converted via cholesterol 24‐hydroxylase (Cyp46A1) to 24S‐hydroxycholesterol (24S‐OHC), the principal route through which cholesterol is ordinarily removed from the brain. Here, we show that while there were no genotypic differences in the concentrations in plasma and liver of three cholesterol precursors (lanosterol, lathosterol, and desmosterol), two plant sterols (sitosterol and campesterol), and two oxysterols (27‐hydroxycholesterol [27‐OHC] and 24S‐OHC), the brains of the Mecp2 ^?/y mice had significantly lower concentrations of all three cholesterol precursors, campesterol, and both oxysterols, with the level of 24S‐OHC being ~20% less than in their Mecp2 ^+/y controls. Together, these data suggest that coordinated regulation of cholesterol synthesis and catabolism in the central nervous system is maintained in this model for RS. Furthermore, we speculate that the adaptive changes in these two pathways conceivably resulted from a shift in the permeability of the blood–brain barrier as implied by the significantly lower campesterol and 27‐OHC concentrations in the brains of the Mecp2^?/y mice.     

Marital psychological and physical aggression and children's mental and physical health: Direct, mediated, and moderated effects.

Relations between marital aggression (psychological and physical) and children's health were examined. Children's emotional insecurity was assessed as a mediator of these relations, with distinctions made between marital aggression against mothers and fathers and ethnicity (African American or European American), socioeconomic status, and child gender examined as moderators of effects. Participants were 251 community-recruited families, with multiple reporters of each construct. Aggression against either parent yielded similar effects for children. Children's emotional insecurity mediated the relation between marital aggression and children's internalizing, externalizing, and posttraumatic stress disorder symptoms. No differences were found in these pathways for African American and European American families or as a function of socioeconomic status or child gender. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nonsuicidal self-injury in young adolescent girls: Moderators of the distress-function relationship.

This study examined nonsuicidal self-injury (NSSI) in a community sample of young adolescent girls. Potential moderators of the relationships between different types of distress (internal and interpersonal) and particular functions of NSSI (emotion-regulation and interpersonal) were explored. Participants included 94 girls (49% Hispanic; 25% African American) ages 10-14 years who completed questionnaires regarding self-injurious behavior and other constructs of interest. Fifty-six percent of girls (n = 53) reported engaging in NSSI during their lifetime, including 36% (n = 34) in the past year. Internal distress (depressive symptoms) was associated with engaging in NSSI for emotion-regulation functions, and rumination moderated the relationship between depressive symptoms and engaging in NSSI for automatic positive reinforcement. Interpersonal distress (peer victimization) was associated with engaging in NSSI for social reinforcement, and quality of peer communication moderated this relationship. The clinical implications of these findings include designing preventions that address the particular contexts of self-injurious behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paradigms for the design of interactive drama

The essential purpose of drama, whether it is theatre, film or television, is to evoke subjective experience in its audience. The advent of interactive digital television opens up many new possibilities for the structure and presentation of drama and the way in which people may engage with it. However, the design of interactive, computer-based environments requires theoretical and practical bases that are largely new to the dramatic arts. This paper describes research which is exploring the convergence of ideas and design models from a range of traditional sources including HCl, psychology, the performing arts and media production for this new media form. It starts by reevaluating two traditional dramatic paradigms, Stanislavski's Realism and Brecht's objectivity, and contrasts them with Boal's spect-actor paradigm in which audiences become direct participants in the drama. Although existing technology cannot enable a faithful computer based implementation of the spect-actor paradigm, the model may be approachable in various ways and thus provides a useful goal for designers of interactive drama. The realities of designing and producing interactive drama are illustrated with a practical example. The paper concludes with a discussion of the implications of the work for the design of interactive drama.