532 research outputs found
Patterns of Methamphetamine Use During Pregnancy: Results from the Infant Development, Environment, and Lifestyle (IDEAL) Study
The objectives of this study are to characterize methamphetamine (MA) usage patterns during pregnancy, examine whether patterns of MA use are associated with sociodemographic characteristics and prenatal care, and test the hypothesis that persistent or increasing MA use during pregnancy is associated with greater use of other illicit drugs. The sample consisted of 191 MA-using mothers who participated in a large-scale multi-site study of prenatal MA exposure. Patterns of substance use were assessed by maternal self-report via the Substance Use Inventory (SUI), which included detailed information about MA use, including frequency, quantity, and maximum use during each trimester of pregnancy. The study demostrated that on average, the prevalence of MA use decreased over the three trimesters of pregnancy (84.3% vs. 56.0% vs. 42.4%), and decreased frequency was observed among users from the first trimester to the third (3.1 vs. 2.4 vs. 1.5Â days/week). Closer examination of the individual patterns revealed that 29.3% of women maintained consistently high frequency, 9.4% increased frequency, 25.7% had a stable low/moderate pattern, and 35.6% decreased their frequency of MA over the course of pregnancy. These four groups did not differ in sociodemographic characteristics; women who decreased their use of MA had significantly more prenatal visits compared to the consistently high-use group, but were the most likely to use alcohol during their pregnancy. In conclusion, this article elucidated the different patterns of MA use in this community sample. Approximately, one third of MA-using mothers could be classified as consistently high users with a profile of use with the greatest risk to themselves and potentially to their infants including high levels of MA use throughout pregnancy and fewer prenatal care visits. Overall, we found that MA use declined across pregnancy; however, a substantial proportion of users had consistently high or increasing MA use, while those who decreased their MA frequency had a higher prevalence of polydrug use. Future research will investigate the association of these patterns with neonatal outcomes
Nanosecond image processing using stimulated photon echoes
Processing of two-dimensional images on a nanosecond time scale is demonstrated using the stimulated photon echoes in a rare-earth-doped crystal (0.1 at. \% Pr3:LaF3). Two spatially encoded laser pulses (pictures) resonant with the 3P0-3H4 transition of Pr3 were stored by focusing the image pulses sequentially into the Pr3:LaF3 crystal. The stored information is retrieved and processed by a third read pulse, generating the echo that is the spatial convolution or correlation of the input images. Application of this scheme to high-speed pattern recognition is discussed
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Tank Farm WM-182 and WM-183 Heel Slurry Samples PSD Results
Particle size distribution (PSD) analysis of INTEC Tank Farm WM-182 and WM-183 heel slurry samples were performed using a modified Horiba LA-300 PSD analyzer at the RAL facility. There were two types of testing performed: typical PSD analysis, and setting rate testing. Although the heel slurry samples were obtained from two separate vessels, the particle size distribution results were quite similar. The slurry solids were from approximately a minimum particle size of 0.5 mm to a maximum of 230 mm with about 90% of the material between 2-to-133 mm, and the cumulative 50% value at approximately 20 mm. This testing also revealed that high frequency sonication with an ultrasonic element may break-up larger particles in the WM-182 and WM-183 tank from heel slurries. This finding represents useful information regarding ultimate tank heel waste processing. Settling rate testing results were also fairly consistent with material from both vessels in that it appears that most of the mass of solids settle to an agglomerated, yet easily redispersed layer at the bottom. A dispersed and suspended material remained in the ''clear'' layer above the settled layer after about one-half an hour of settling time. This material had a statistical mode of approximately 5 mm and a maximum particle size of 30 mm
Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015).
BACKGROUND: Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB.
METHODS: Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately.
RESULTS: Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p \u3c .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation.
CONCLUSIONS: In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes
Solar cycle variability of Mars dayside exospheric temperatures: Model evaluation of underlying thermal balances
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95086/1/grl25450.pd
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