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The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
On Thursday, 20 February 1755, William Stukeley presented “An Historical Dissertation upon the antient Danish Horn, kept in the Cathedral Church of York” to the Society of Antiquaries of London. The essay was probably familiar to some of the older Fellows, having been read to the Society in 1718 by its author, Samuel Gale. Its subject was the Horn of Ulf, then on display in the sacristy of York Minster. According to Gale, “of all the curiosities which a traveller sees, in visiting the great church of York, nothing can more merit the sedulous notice of the Antiquary, than that large vessel of ivory.”
Stukeley's 1755 rereading of Gale's essay sparked renewed interest in charter horns among English medievalist antiquaries. The “Dissertation” was deemed interesting enough to be included in the first issue of Archaeologia in 1770. The third issue, printed in 1775, opens with a further seven articles on horns ranging from a drinking horn from Corpus Christi College, Cambridge, to a pair of mammoth tusks at Carlisle Cathedral, which Charles Lyttelton partly confused with a hunting horn known to have been given to the cathedral by Henry I. For the rest of the century, references to charter horns continued to appear in the Society's minute books, in periodicals such as Archaeologia, and in a series of popular prints sold to historically minded collectors. According to two modern historians, both before and after Gale “a constant trickle of curious tourists” were “gratified by the sight of Ulphus's horn,” from Celia Fiennes and Daniel Defoe in the seventeenth century to the Duke of York in 1766. This particular antiquarian curiosity was also a notable tourist attraction.
Mostly uninscribed, and almost entirely without accompanying documentary evidence that is contemporary or near contemporary with their creation, charter horns have been largely forgotten by academic medievalists. The wealth of family tradition and local lore that surround charter horns – which made them so appealing to early modern antiquaries – seems to have had almost the opposite effect on twentieth- and twenty-first- century scholars.
Identifying youth who may engage in future substance use could facilitate early identification of substance use disorder vulnerability. We aimed to identify biomarkers that predicted future substance use in psychiatrically un-well youth.
LASSO regression for variable selection was used to predict substance use 24.3 months after neuroimaging assessment in 73 behaviorally and emotionally dysregulated youth aged 13.9 (s.d. = 2.0) years, 30 female, from three clinical sites in the Longitudinal Assessment of Manic Symptoms (LAMS) study. Predictor variables included neural activity during a reward task, cortical thickness, and clinical and demographic variables.
Future substance use was associated with higher left middle prefrontal cortex activity, lower left ventral anterior insula activity, thicker caudal anterior cingulate cortex, higher depression and lower mania scores, not using antipsychotic medication, more parental stress, older age. This combination of variables explained 60.4% of the variance in future substance use, and accurately classified 83.6%.
These variables explained a large proportion of the variance, were useful classifiers of future substance use, and showed the value of combining multiple domains to provide a comprehensive understanding of substance use development. This may be a step toward identifying neural measures that can identify future substance use disorder risk, and act as targets for therapeutic interventions.
This study investigated the relationship between insulin-resistance and constituent components of executive function in a sample of neurologically intact older adult subjects using the homeostasis model assessment (HOMA-IR) and latent factors of working memory, cognitive control and processing speed derived from confirmatory factor analysis. Low-density lipoprotein (LDL), mean arterial pressure (MAP), along with body mass index (BMI) and white matter hypointensity (WMH) were used to control for vascular risk factors, adiposity and cerebrovascular injury. The study included 119 elderly subjects recruited from the University of California, San Francisco Memory and Aging Center. Subjects underwent neuropsychological assessment, fasting blood draw and brain magnetic resonance imaging (MRI). Partial correlations and linear regression models were used to examine the HOMA-IR-executive function relationship. Pearson correlation adjusting for age showed a significant relationship between HOMA-IR and working memory (rp=−.18; p=.047), a trend with cognitive control (rp=−.17; p=.068), and no relationship with processing speed (rp=.013; p=.892). Linear regression models adjusting for demographic factors (age, education, and gender), LDL, MAP, BMI, and WMH indicated that HOMA-IR was negatively associated with cognitive control (r=−.256; p=.026) and working memory (r=−.234; p=.054). These results suggest a greater level of peripheral insulin-resistance is associated with decreased cognitive control and working memory. After controlling for demographic factors, vascular risk, adiposity and cerebrovascular injury, HOMA-IR remained significantly associated with cognitive control, with working memory showing a trend. These findings substantiate the insulin-resistance-executive function hypothesis and suggest a complex interaction, demonstrated by the differential impact of insulin-resistance on processing speed and specific aspects of executive function. (JINS, 2015, 21, 622–628)
Imprinted genes often affect body size-related traits such as weight. However, the association of imprinting with obesity, especially childhood obesity, has not been well studied. Mexican-American children have a high prevalence, approaching 50%, of obesity and/or overweight. In a pilot study of 75 Mexican-American children, we analyzed the relationships among obese/overweight status, methylation status and single-nucleotide polymorphism (SNP) status at a CpG site in a differentially methylated region (DMR) of the imprinted H19/IGF2 locus. We observed a significant difference in SNP rs10732516 frequency between boys and girls among the overweight and obese children but not among the lean children. We also found that children with lower methylation of the polymorphic CpG site (CpG4) in the H19 DMR had higher birth weights than did children with higher methylation (P = 0.04). Our results suggest that CpG4 methylation status may be associated with childhood obesity in Mexican-American children in a sex-specific manner.
Loring et al. (Journal of Clinical and Experimental Neuropsychology, 2005:27;610–617) observed relationships between VSVT hard item performance and IQ and memory indices in epilepsy surgical candidates, with a potential confound of low FSIQ on VSVT performance. The present study replicated the Loring et al. study in a larger sample and extended their findings by examining the relationships among VSVT performance, FSIQ, and working memory. A total of 404 patients with medically intractable epilepsy completed a comprehensive neuropsychological assessment. Differences in WAIS-III and WMS-III performance were examined as a function of VSVT hard score categories as determined by Grote et al. (2000)—that is, valid, >20/24; questionable, 18–20; or invalid, <18. Quantile regression models were constructed to compare the strength of the relationship between FSIQ and VSVT at various points of the FSIQ distribution. Linear regression analyses examined working memory as a potential mediator between FSIQ and VSVT performance. The invalid group performed more poorly than the valid and questionable groups on multiple measures of intelligence and memory. The strength of the relationship between FSIQ and VSVT hard item performance decreased as FSIQ increased, and working memory mediated this relationship. Results suggest VSVT hard item scores may be impacted by working memory difficulties and/or low intellectual functioning. (JINS, 2013, 19, 1–10)
Increased reaction time variability (RTV) on cognitive tasks requiring a speeded response is characteristic of several psychiatric disorders. In attention deficit hyperactivity disorder (ADHD), the association with RTV is strong phenotypically and genetically, yet high RTV is not a stable impairment but shows ADHD-sensitive improvement under certain conditions, such as those with rewards. The state regulation theory proposed that the RTV difference score, which captures change from baseline to a rewarded or fast condition, specifically measures ‘state regulation’. By contrast, the interpretation of RTV baseline (slow, unrewarded) scores is debated. We aimed to investigate directly the degree of phenotypic and etiological overlap between RTV baseline and RTV difference scores.
We conducted genetic model fitting analyses on go/no-go and fast task RTV data, across task conditions manipulating rewards and event rate, from a population-based twin sample (n=1314) and an ADHD and control sibling-pair sample (n=1265).
Phenotypic and genetic/familial correlations were consistently high (0.72–0.98) between RTV baseline and difference scores, across tasks, manipulations and samples. By contrast, correlations were low between RTV in the manipulated condition and difference scores. A comparison across two different go/no-go task RTV difference scores (slow-fast/slow-incentive) showed high phenotypic and genetic/familial overlap (r = 0.75–0.83).
Our finding that RTV difference scores measure largely the same etiological process as RTV under baseline condition supports theories emphasizing the malleability of the observed high RTV. Given the statistical shortcomings of difference scores, we recommend the use of RTV baseline scores for most analyses, including genetic analyses.
In this work, pulsed electron deposition was used to prepare thin films of ITO on plastic substrates. These films were used as electrodes for organic photovoltaic devices to determine the feasibility of using PED deposited ITO as electrodes. ITO films deposited on plastic showed optical transmission values as high as 85% for films deposited at high pressures. Films deposited on plastic substrates were further used to prepare a test organic solar cell, with ITO as the bottom electrode. The device performance was seen to depend on the quality of the ITO electrode, and the ITO film deposited at the lowest oxygen pressure was found to be the best electrode for the organic photovoltaic device.
Epitaxial growth of the ferromagnetic semiconductors GaMnP:C and GaMnN has been investigated by Gas Source Molecular Beam Epitaxy (GSMBE). GaMnP:C films grown with 9.4% Mn are found to be p-type with hysteretic behavior to room temperature. GaMnN films grown at 700 °C with 2.8% Mn show hysteresis at 300 K, while temperature-dependent magnetization measurements indicate that the magnetism may persist to much higher temperatures (> 325 K). Samples of AlGaMnN have also been prepared for the first time that show improved surface morphology compared to GaMnN but which show only paramagnetic behavior.
We have reported previously that metal poly-ynes have large thirdorder optical susceptibilities. Based on the four-wave mixing studies reported here, we conclude that strong two-photon absorptions in metal poly-ynes contribute significantly to the observed third-order nonlinearities of these materials. Hyperpolarizability/r.u. increases only slightly with chain length for tetrahydrofuran solutions of the metal poly-ynes. The possible influence of conformers on this behavior is discussed.
Efficient, phase-matched second-harmonic generation of 1.064 µm radiation has been observed with single crystals of 4-aminobenzophenone (ABP). These crystals are tr nsparent from 420–2000 nm and have damage thresholds exceeding 30 GW/cm2 (for a 30-picosecond laser pulse).
The piezoresistive effect of materials is used as the basis for many types of microsensors. Polyimide, a material widely used in microelectronic fabrication, may be made to exhibit this effect by addition of small graphite particles to form a composite material. Polyimide / graphite based piezoresistive films have the advantage of being spin-castable, plasma-processable, highly chemically resistant, and thermally stable up to 400 °C in nitrogen atmospheres. In this work, piezoresistive polyimide films are formed by addition of various amounts (loadings) of graphite particles one micron in diameter or less to DuPont PI-2555 polyimide. Thin films of these materials are spin-cast on silicon wafers, and an in-situ load-deflection measurement technique is used to evaluate the following film properties: piezoresistive coefficient as a function of both strain and graphite loading; Young's modulus as a function of graphite loading; and residual film stress as a function of graphite loading. The observed piezoresistive coefficient is a strong function of graphite loading, with good piezoresistive properties exhibited in the loading range of 15–25 wt% graphite.
Existing semiconductor electronic and photonic devices utilize the charge on electrons and holes in order to perform their specific functionality such as signal processing or light emission. The relatively new field of semiconductor spintronics seeks, in addition, to exploit the spin of charge carriers in new generations of transistors, lasers and integrated magnetic sensors. The ability to control of spin injection, transport and detection leads to the potential for new classes of ultra-low power, high speed memory, logic and photonic devices. The utility of such devices depends on the availability of materials with practical (>300K) magnetic ordering temperatures. In this paper, we summarize recent progress in dilute magnetic semiconductors such as (Ga,Mn)N, (Ga,Mn)P and (Zn,Mn)O exhibiting room temperature ferromagnetism, the origins of the magnetism and its potential applications in novel devices such as spin-polarized light emitters and spin field effect transistors.
GaN and AlN thin films were implanted with gadolinium (Gd)atoms and characterized using deep ultra-violet (UV) photoluminescence(PL). The Gd-implanted samples were annealed at temperatures up to 1178K in a flowing N2 gas to facilitate recovery of implantation-related damage. Using the output at 195 nm from a quadrupled Ti:sapphire laser, narrow PL emission was observed at 318 nm from the Gd- implanted AlN thin films. This emission is characteristic of the lowest energy 4f transition of the trivalent Gd ion. A boarder emission band, also centered at 318 nm, was observed under excitation at 266 nm. No PL emission was observed from the Gd-implanted GaN thin films at either the bandedge or due to a 4f transition. The dependence of the UV emission on AlN sample temperature was systematically studied. The peak PL emission intensity decreased by less that a factor of 3 over the temperature range of 10 K to 300 K. Decay transients of the UV emission were measured indicating that the lifetime of this emission is very fast.
Single phase GaGdN and GaGdN:Si films were grown on sapphire substrates. The undoped films were highly resistive films but became conductive with the addition of Si. SQUID magnetometry indicated room temperature ferromagnetism in both types of materials. Structural defects had a strong influence on the magnetic ordering of the material, as seen in a drastic reduction of magnetic moment with degrading crystalline quality. Magnetization of the co-doped film increased with Si content, reaching levels higher than that of the undoped material. Gd-doped AlN films grown in a similar fashion also displayed Curie temperatures above room temperature.