Prevalence and Correlates of Cannabis Use in Massachusetts after Cannabis Legalization and before Retail Sales.

We determined the prevalence and correlates of cannabis use in Massachusetts after recreational use was passed, but before recreational cannabis stores opened. A cross-sectional, population-based survey of Massachusetts adults, age 18 years or older, (n = 3,022) was conducted in November-December, 2017. We estimated population-level prevalence and correlates of past 30-day cannabis use. 21.1% [95% CI: 18.6, 23.6] of Massachusetts adults reported past 30-day cannabis use. Among cannabis users, 56.0% [CI 49.1, 62.9] reported non-medical cannabis use, 15.5% [12.1, 18.9] reported medical cannabis use, and 28.5% [CI 22.3, 34.8] reported both types of use. Men were more likely than women to use cannabis (Risk Ratio: 1.3 [CI 1.1, 1.6]), as were young adults (18-25 years old), those with lower socioeconomic status, non-parenting individuals, those who used alcohol (1.9 [CI 1.4, 2.6]) or other substances (1.7 [CI 1.3, 2.4]), and residents of Western Massachusetts (2.0 [1.3, 3.0]; ref: Boston area), the Northeast (1.8 [CI 1.2, 2.7]), and the Southeast (1.8 [CI 1.1, 2.7]). Cannabis is widely used in Massachusetts, with varying prevalence rates by gender, age, socioeconomic status, poly-substance use, and region. Findings may inform public health efforts and serve as a baseline for measuring health and social impacts of opening retail cannabis stores.

Estimating the range of the maximum hormetic stimulatory response.

An ever-expanding hormetic database (HDB) was used to demonstrate that the median maximal hormetic stimulatory response (MHSR) of biphasic dose-response relationships increases in value with an increase in the number of stimulatory doses/concentrations that are administered below the estimated threshold/ZEP (zero equivalent point - i.e., the dose where the response crosses the control group value). With only one dose or concentration administered below the ZEP, the median MHSR for microbes (in vitro), animals (in vitro and in vivo), and plants (in vitro and in vivo) ranged between 120% and 125% of the control response. However, when individual agents having at least six doses below the ZEP were mined from the HDB (and a median MHSR then determined), the median MHSR increased to 160-190%. This progressive increase in the MHSR appears to be due to several factors, including (i) the enhanced capacity of additional doses in the stimulatory hormetic zone to better estimate the response optima, and (ii) enhanced variability due to the presence of more doses in the stimulatory zone. This study offers a novel perspective for improving research protocols, unraveling the limits of biological plasticity, understanding low-level stress biology, advancing human and ecological health, and enhancing human performance.

The importance of friends and family to recreational gambling, at-risk gambling, and problem gambling.

BACKGROUND: The variables correlated with problem gambling are routinely assessed and fairly well established. However, problem gamblers were all 'at-risk' and 'recreational' gamblers at some point. Thus, it is instructive from a prevention perspective to also understand the variables which discriminate between recreational gambling and at-risk gambling and whether they are similar or different to the ones correlated with problem gambling. This is the purpose of the present study. METHOD: Between September 2013 to May 2014, a representative sample of 9,523 Massachusetts adults was administered a comprehensive survey of their past year gambling behavior and problem gambling symptomatology. Based on responses to the Problem and Pathological Gambling Measure, respondents were categorized as Non-Gamblers (2,523), Recreational Gamblers (6,271), At-Risk Gamblers (600), or Problem/Pathological Gamblers (129). With the reference category of Recreational Gambler, a series of binary logistic regressions were conducted to identify the demographic, health, and gambling related variables that differentiated Recreational Gamblers from Non-Gamblers, At-Risk-Gamblers, and Problem/Pathological Gamblers. RESULTS: The strongest discriminator of being a Non-Gambler rather than a Recreational Gambler was having a lower portion of friends and family that were regular gamblers. Compared to Recreational Gamblers, At-Risk Gamblers were more likely to: gamble at casinos; play the instant and daily lottery; be male; gamble online; and be born outside the United States. Compared to Recreational Gamblers, Problem and Pathological Gamblers were more likely to: play the daily lottery; be Black; gamble at casinos; be male; gamble online; and play the instant lottery. Importantly, having a greater portion of friends and family who were regular gamblers was the second strongest correlate of being both an At-Risk Gambler and Problem/Pathological Gambler. CONCLUSIONS: These analyses offer an examination of the similarities and differences between gambling subtypes. An important finding throughout the analyses is that the gambling involvement of family and friends is strongly related to Recreational Gambling, At-Risk Gambling, and Problem/Pathological Gambling. This suggests that targeting the social networks of heavily involved Recreational Gamblers and At-Risk Gamblers (in addition to Problem/Pathological Gamblers) could be an important focus of efforts in problem gambling prevention.

The Health Behaviors of Ethnically Diverse Women at Increased Risk of Gestational Diabetes: The Behaviors Affecting Baby and You (B.A.B.Y.) Study.

Objectives Cigarette smoking, low physical activity, and sedentary behavior are modifiable risk factors for adverse pregnancy outcomes. However, only one study has evaluated predictors of these health risk behaviors among women at high risk for gestational diabetes mellitus (GDM). Therefore, our goal was to examine predictors of smoking, low physical activity, and sedentary behavior during pregnancy in an ethnically diverse high risk cohort. Methods This cross-sectional analysis utilized baseline data from the Behaviors Affecting Baby and You (B.A.B.Y.) study conducted among prenatal care patients at high risk for GDM (personal history of GDM or family history of diabetes and body mass index [BMI] ≥ 25 kg/m2). Smoking was assessed using questions from the Pregnancy Risk Assessment Monitoring System questionnaire and sedentary behavior (top vs. lower quartiles) and moderate/vigorous physical activity (bottom vs. upper quartile) via the Pregnancy Physical Activity Questionnaire. Results Participants (n = 400) enrolled at a mean of 12.4 (SD 3.6) weeks gestation. A total of 150 (44.1%) engaged in one, 37 (10.9%) in two, and 4 (1.2%) in three risk behaviors. Lower household income and not having children at home were each associated with a 2-6 fold increased odds of smoking, high sedentary behavior, and engaging in at least one risk behavior. Being married, Hispanic or of younger age was associated with a 2-6 fold reduced odds of smoking. BMI and personal history of GDM were not associated with risk behaviors. Conclusions for Practice Findings help characterize high risk groups and inform prenatal interventions targeting these health risk behaviors.

The Effect of an Exercise Intervention on Gestational Weight Gain: The Behaviors Affecting Baby and You (B.A.B.Y.) Study: A Randomized Controlled Trial.

PURPOSE: To examine the effect of a prenatal exercise intervention on gestational weight gain (GWG) and to update meta-analyses. DESIGN: Randomized controlled trial and meta-analysis. SETTING: Obstetrical practices in a Western Massachusetts hospital. PATIENTS: We analyzed 241 ethnically diverse pregnant participants at high risk for gestational diabetes in the Behaviors Affecting Baby and You (B.A.B.Y.) study. A total of 118 participants were randomized to an exercise intervention group and 123 to a comparison health and wellness intervention group. INTERVENTION: A 12-week individually tailored, motivationally matched program designed to increase the compliance with guidelines for exercise during pregnancy (30 min/day). MEASURES: The GWG and compliance with 2009 Institute of Medicine (IOM) guidelines for GWG abstracted from medical records. ANALYSIS: Unadjusted logistic regression, intent-to-treat. Results were added to the existing meta-analyses using a random effects model. RESULTS: Women randomized to the exercise group had a lower mean GWG than the comparison group (-0.97 kg, P value = .39) and were less likely to exceed IOM guidelines (odds ratio = 0.69, 95% confidence interval [CI] 0.34-1.40), but results were not statistically significant. Meta-analyses yielded a -0.63 kg (95% CI -1.17 to -0.08, P = .02) reduction in GWG and a 20% reduction in odds of exceeding IOM guidelines (95% CI 0.73 to 0.89) for the exercise intervention. CONCLUSION: Findings from this randomized trial among ethnically diverse women contribute to the results of meta-analyses supporting exercise as a means of attenuating GWG.

Intensive Language Action Therapy in Chronic Aphasia: A Randomized Clinical Trial Examining Guidance by Constraint.

Purpose: Intensive language action therapy (ILAT) can be effective in overcoming learned nonuse in chronic aphasia. It is suggested that all three guiding principles (constraint, communication embedding, massed practice) are essential to ILAT's success. We examined whether one of these, guidance by constraint, is critical. Method: Twenty-four participants with aphasia (PWAs) were assigned to ILAT or a modified version of promoting aphasic communicative effectiveness (PACE) in a randomized block, single-blind, parallel-group treatment study. Blocking was by severity (mild/moderate, moderate to severe, severe). Both groups received intensive treatment in the context of therapeutic language action games. Whereas the ILAT group was guided toward spoken responses, the PACE group could choose any response modality. Results: All participants, whether assigned to ILAT or PACE groups, improved on the primary outcome measure, picture naming. There was a Severity × Treatment interaction, with the largest effects estimated for PWAs with mild/moderate and moderate to severe aphasia. Regardless of severity, the ILAT group outperformed the PACE group on untrained pictures, suggesting some benefit of ILAT to generalization. However, this difference was not statistically significant. Conclusion: Although the groups differed in subtle ways, including better generalization to untrained pictures for ILAT, the study was inconclusive on the influence of guidance by constraint.

Urinary bisphenol-A, phthalate metabolites and body composition in US adults, NHANES 1999-2006.

BACKGROUND: Exposure to bisphenol-A (BPA) and phthalates is highly prevalent. Prior studies have not assessed associations between urinary levels of BPA and phthalate metabolites and body composition. METHODS: National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2006 on adults aged ≥20 were analyzed by linear regression for associations between urinary BPA, monoethyl phthalate, monobutyl phthalate (MBP), monoethylhexyl phthalate (MEHP), and monobenzyl phthalate (MBzP) and lean mass, fat mass, and percent body fat. RESULTS: BPA and phthalate metabolites were not independently associated with fat mass or percent body fat. Significant inverse associations were observed with lean mass, with the strongest association observed for BPA in men (mean lean mass 1.39 kg lower for quartile 4 vs. quartile 1, p trend = 0.02). CONCLUSIONS: BPA and some phthalates could have important, negative effects on muscle and may affect conditions related to deficits in lean mass, though additional research is needed.

Supratrigeminal Bilaterally Projecting Neurons Maintain Basal Tone and Enable Bilateral Phasic Activation of Jaw-Closing Muscles.

UNLABELLED: Anatomical studies have identified brainstem neurons that project bilaterally to left and right oromotor pools, which could potentially mediate bilateral muscle coordination. We use retrograde lentiviruses combined with a split-intein-mediated split-Cre-recombinase system in mice to isolate, characterize, and manipulate a population of neurons projecting to both the left and right jaw-closing trigeminal motoneurons. We find that these bilaterally projecting premotor neurons (BPNs) reside primarily in the supratrigeminal nucleus (SupV) and the parvicellular and intermediate reticular regions dorsal to the facial motor nucleus. These BPNs also project to multiple midbrain and brainstem targets implicated in orofacial sensorimotor control, and consist of a mix of glutamatergic, GABAergic, and glycinergic neurons, which can drive both excitatory and inhibitory inputs to trigeminal motoneurons when optogenetically activated in slice. Silencing BPNs with tetanus toxin light chain (TeNT) increases bilateral masseter activation during chewing, an effect driven by the expression of TeNT in SupV BPNs. Acute unilateral optogenetic inhibition of SupV BPNs identifies a group of tonically active neurons that function to lower masseter muscle tone, whereas unilateral optogenetic activation of SupV BPNs is sufficient to induce bilateral masseter activation both during resting state and during chewing. These results provide evidence for SupV BPNs in tonically modulating jaw-closing muscle tone and in mediating bilateral jaw closing. SIGNIFICANCE STATEMENT: We developed a method that combines retrograde lentiviruses with the split-intein-split-Cre system in mice to isolate, characterize, and manipulate neurons that project to both left and right jaw-closing motoneurons. We show that these bilaterally projecting premotor neurons (BPNs) reside primarily in the supratrigeminal nucleus and the rostral parvicellular and intermediate reticular nuclei. BPNs consist of both excitatory and inhibitory populations, and also project to multiple brainstem nuclei implicated in orofacial sensorimotor control. Manipulation of the supratrigeminal BPNs during natural jaw-closing behavior reveals a dual role for these neurons in eliciting phasic muscle activation and in maintaining basal muscle tone. The retrograde lentivirus carrying the split-intein-split-Cre system can be applied to study any neurons with bifurcating axons innervating two brain regions.

Proyecto Mamá: a lifestyle intervention in overweight and obese Hispanic women: a randomised controlled trial--study protocol.

BACKGROUND: The proportion of women entering pregnancy overweight or obese has been rising and, in turn, is associated with adverse maternal and fetal outcomes. Gestational weight gain (GWG) exceeding Institute of Medicine (IOM) guidelines further increases health risks and has been independently associated with postpartum weight retention. Hispanic women are disproportionately affected by overweight and obesity, but have had limited access to interventions that promote healthy lifestyles due to cultural, socioeconomic, and language barriers. Therefore, the overall goal of this randomized controlled trial is to test the efficacy of a culturally and linguistically modified, individually-tailored lifestyle intervention to reduce excess GWG, increase postpartum weight loss, and improve maternal metabolic status among overweight/obese Hispanic women. METHODS/DESIGN: Overweight/obese Hispanic women are recruited in early pregnancy and randomly assigned to a Lifestyle Intervention (n = 150) or a Comparison Health and Wellness (control) intervention (n = 150). Multimodal contacts (i.e., in-person, telephone counseling, and mailed print-based materials) are used to deliver the intervention from early pregnancy (12 weeks gestation) to 6 months postpartum, with follow-up to 1 year postpartum. Targets of the intervention are to achieve IOM Guidelines for GWG and postpartum weight loss; American Congress of Obstetrician and Gynecologist guidelines for physical activity; and American Diabetes Association guidelines for diet. The intervention draws from Social Cognitive Theory and the Transtheoretical Model and includes strategies to address the specific social, cultural, and economic challenges faced by low-income Hispanic women. Assessments are conducted at baseline (~10 weeks gestation), mid pregnancy (24-28 weeks gestation), late pregnancy (32-34 weeks gestation) and postpartum at 6-weeks, 6-months, and 12-months by bicultural and bilingual personnel blinded to the intervention arm. Efficacy is assessed via GWG, postpartum weight loss, and biomarkers of glycemic control, insulin resistance, and cardiovascular disease risk factors. Changes in physical activity and diet are measured via 7-day accelerometer data and 24-h dietary recalls at each assessment time period. DISCUSSION: Hispanic women are the fastest growing minority group in the U.S. and are disproportionately affected by overweight and obesity. This randomised trial uses a high-reach, low-cost strategy that can readily be translated into clinical practice in underserved and minority populations. TRIAL REGISTRATION: NCT01868230 May 29, 2013.

The impact of an exercise intervention on C - reactive protein during pregnancy: a randomized controlled trial.

BACKGROUND: C-reactive protein (CRP) during pregnancy has been associated with adverse maternal outcomes such as preeclampsia and gestational diabetes mellitus. Randomized trials suggest that exercise programs may be associated with reductions in CRP in non-pregnant populations; however, such studies have not been conducted among pregnant women. The purpose of this study was to evaluate the impact of an individually-tailored motivationally-matched exercise intervention on CRP in pregnant women. METHODS: The Behaviors Affecting Baby and You study was a randomized controlled trial of prenatal physical activity to prevent the development of gestational diabetes mellitus in women at increased risk. Women were randomized to either a 12-week exercise intervention (n = 84) or a comparison health and wellness intervention (n = 87). High sensitivity CRP (mg/dL) was measured using a commercial immunoassay kit. Physical activity was measured using the Pregnancy Physical Activity Questionnaire. Mixed model analyses were used to evaluate the impact of the intervention on change in CRP using an intent-to-treat approach. RESULTS: CRP decreased (-0.09 mg/dL, 95 % CI: -0.25, 0.07) from pre- to post-intervention in the exercise arm (p = 0.14) and increased (0.08 mg/dL, 95 % CI: -0.07, 0.24) (p = 0.64) in the health and wellness arm; however the between group difference was not statistically significant (p = 0.14). Findings did not differ according to ethnic group or pre-pregnancy body mass index. In a secondary analysis based on self-reported physical activity, women who decreased their time spent in sports/exercise experienced a mean increase in CRP (0.09 mg/dL, 95 % CI: -0.14, 0.33), whereas women who maintained or increased their sports/ exercise experienced a mean decrease in CRP (-0.08 mg/dL, 95 % CI: -0.23, 0.08) (p = 0.046). CONCLUSIONS: Findings from this randomized trial in an ethnically and socio-economically diverse population of pregnant women were consistent with a positive impact of the exercise intervention on CRP levels, but not of statistical significance. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT00728377 . Registered 2 August 2008.

Effect of an exercise intervention on gestational diabetes mellitus: a randomized controlled trial.

OBJECTIVE: To examine the effect of an individually tailored, motivationally matched prenatal exercise intervention on gestational diabetes mellitus (GDM) and other measures of glucose intolerance among ethnically diverse prenatal care patients at increased risk for GDM. METHODS: The Behaviors Affecting Baby and You study randomized eligible women at a mean (standard deviation) of 18.2 (4.1) weeks of gestation to a 12-week individually tailored, motivationally matched exercise intervention or a comparison health and wellness intervention. The goal of the exercise intervention was to achieve the American College of Obstetricians and Gynecologists' guidelines for physical activity during pregnancy. Diagnosis of GDM, impaired glucose tolerance, abnormal glucose screen, and screening glucose values (mg/dL) were abstracted from medical records. A sample size of 352 women (176 per group) was planned to have 80% power to detect reductions in risk of 35% or larger. RESULTS: From July 2007 to December 2012, a total of 251 (86.5%) women completed the intervention; n=124 and 127 in the exercise and comparison interventions, respectively. Based on an intention-to-treat analysis, no statistically significant differences between the intervention groups were observed; the relative odds of GDM in the exercise group was 0.61 (95% confidence interval [CI] 0.28-1.32) as compared with the health and wellness comparison group. Odds ratios for impaired glucose tolerance and abnormal glucose screen were 0.68 (95% CI 0.35-1.34) and 0.86 (95% CI 0.51-1.47), respectively. The intervention had no effect on birth outcomes. CONCLUSION: In this randomized trial among ethnically diverse pregnant women at increased risk for GDM, we found that a prenatal exercise intervention implemented in the second trimester did not result in a statistically significant reduction in relative odds for GDM, impaired glucose tolerance, or abnormal glucose screen. LEVEL OF EVIDENCE: I.

Impact of an exercise intervention on physical activity during pregnancy: the behaviors affecting baby and you study.

OBJECTIVES: We examined the impact of a prenatal exercise intervention on physical activity in 260 women at risk for gestational diabetes mellitus. METHODS: We randomized participants in the Behaviors Affecting Baby and You (BABY) Study, which took place from 2007 to 2012, to either a 12-week individually tailored, motivationally matched exercise intervention (n=132) or to a comparison health and wellness intervention (n=128). We assessed physical activity with the Pregnancy Physical Activity Questionnaire. We used linear mixed models to evaluate the impact of the interventions on change in physical activity according to intensity and type, total walking, and sedentary behavior. RESULTS: Compared with the health and wellness arm, the exercise arm had significantly greater increases in sports or exercise activity (0.3 vs 5.3 metabolic equivalent of task [MET] hours/week; P<.001), and smaller declines in total activity (-42.7 vs -2.1 MET hours/week; P=.02) and activities of moderate to vigorous intensity (-30.6 vs -10.6 MET hours/week; P=.05), and was more likely to achieve recommended guidelines for physical activity (odds ratio=2.12; 95% confidence interval=1.45, 3.10). CONCLUSIONS: These findings extend the previous literature by demonstrating the benefits of a clinically feasible exercise intervention in an ethnically and socio-economically diverse population. Given the increased risk of adverse maternal health outcomes in ethnic minority groups, these findings may have important implications for reducing health disparities.

Monosynaptic premotor circuit tracing reveals neural substrates for oro-motor coordination.

Feeding behaviors require intricately coordinated activation among the muscles of the jaw, tongue, and face, but the neural anatomical substrates underlying such coordination remain unclear. In this study, we investigate whether the premotor circuitry of jaw and tongue motoneurons contain elements for coordination. Using a modified monosynaptic rabies virus-based transsynaptic tracing strategy, we systematically mapped premotor neurons for the jaw-closing masseter muscle and the tongue-protruding genioglossus muscle. The maps revealed that the two groups of premotor neurons are distributed in regions implicated in rhythmogenesis, descending motor control, and sensory feedback. Importantly, we discovered several premotor connection configurations that are ideally suited for coordinating bilaterally symmetric jaw movements, and for enabling co-activation of specific jaw, tongue, and facial muscles. Our findings suggest that shared premotor neurons that form specific multi-target connections with selected motoneurons are a simple and general solution to the problem of orofacial coordination.DOI: http://dx.doi.org/10.7554/eLife.02511.001.

Prediction with measurement errors in finite populations.

We address the problem of selecting the best linear unbiased predictor (BLUP) of the latent value (e.g., serum glucose fasting level) of sample subjects with heteroskedastic measurement errors. Using a simple example, we compare the usual mixed model BLUP to a similar predictor based on a mixed model framed in a finite population (FPMM) setup with two sources of variability, the first of which corresponds to simple random sampling and the second, to heteroskedastic measurement errors. Under this last approach, we show that when measurement errors are subject-specific, the BLUP shrinkage constants are based on a pooled measurement error variance as opposed to the individual ones generally considered for the usual mixed model BLUP. In contrast, when the heteroskedastic measurement errors are measurement condition-specific, the FPMM BLUP involves different shrinkage constants. We also show that in this setup, when measurement errors are subject-specific, the usual mixed model predictor is biased but has a smaller mean squared error than the FPMM BLUP which point to some difficulties in the interpretation of such predictors.

Design-based random permutation models with auxiliary information¶

We extend the random permutation model to obtain the best linear unbiased estimator of a finite population mean accounting for auxiliary variables under simple random sampling without replacement (SRS) or stratified SRS. The proposed method provides a systematic design-based justification for well-known results involving common estimators derived under minimal assumptions that do not require specification of a functional relationship between the response and the auxiliary variables.

Feasibility and efficacy of a physical activity intervention among pregnant women: the behaviors affecting baby and you (B.A.B.Y.) study.

BACKGROUND: Physical activity during pregnancy is associated with reduced risk of adverse maternal and fetal outcomes. However, the majority of pregnant women are inactive and interventions designed to increase exercise during pregnancy are sparse. We evaluated the feasibility and preliminary efficacy of an exercise intervention among a diverse sample of pregnant women. METHODS: The B.A.B.Y. (Behaviors Affecting Baby and You) Study is conducted at a large tertiary care facility in Western Massachusetts. We randomized 110 prenatal care patients (60% Hispanic) to an individually tailored 12-week exercise intervention arm (n = 58) or to a health and wellness control arm (n = 52) at mean = 11.9 weeks gestation. Physical activity was assessed via the Pregnancy Physical Activity Questionnaire (PPAQ). RESULTS: After the 12-week intervention, the exercise arm experienced a smaller decrease (-1.0 MET-hrs/wk) in total activity vs. the control arm (-10.0 MET-hrs/wk; P = .03), and a higher increase in sports/exercise (0.9 MET-hrs/wk) vs. the control arm (-0.01 MET-hrs/wk; P = .02). Intervention participants (95%) reported being satisfied with the amount of information received and 86% reported finding the study materials interesting and useful. CONCLUSIONS: Findings support the feasibility and preliminary efficacy of a tailored exercise intervention in increasing exercise in a diverse sample of pregnant women.

Evidence for hormesis in mutagenicity dose-response relationships.

This study assessed the occurrence of hormetic dose responses from three previously published data sets [1-3] with 825 chemicals in three Ames assay tester strains (i.e., TA97, TA98, TA100) with and without the S9 fraction, using a five dose protocol and semi-log dose spacing. Ninety-five (95) (11.5%) chemicals satisfied the multiple a priori entry criteria, with a total of 107 assays. Of the assays satisfying the entry criteria, 61 involved TA100, a strain that detects base-pair substitution mutations. 29.5% (18/61) satisfied the statistical evaluative criteria for hormesis, exceeding that predicted by chance by 4.0-fold (p<0.001). The remaining 46 assays involved TA97 and TA98, strains that detect frameshift mutations. Of these 46 assays, the overall responses for the lowest two doses closely approximated the control response (e.g., 101.77% of the control for TA98; 99.20% for TA97). Only 2.2% (1/46) of the assays satisfied the evaluative criteria for hormesis. In conclusion, these data support a hormetic model for TA100, whereas the responses for TA97 and TA98 are consistent with a threshold dose-response model.

Feasibility and Efficacy of a Physical Activity Intervention Among Pregnant Women: The Behaviors Affecting Baby and You (B.A.B.Y.) Study.

BACKGROUND: Physical activity during pregnancy is associated with reduced risk of adverse maternal and fetal outcomes. However, the majority of pregnant women are inactive and interventions designed to increase exercise during pregnancy are sparse. We evaluated the feasibility and preliminary efficacy of an exercise intervention among a diverse sample of pregnant women. METHODS: The B.A.B.Y. (Behaviors Affecting Baby and You) Study is conducted at a large tertiary care facility in Western Massachusetts. We randomized 110 prenatal care patients (60% Hispanic) to an individually tailored 12-week exercise intervention arm (n = 58) or to a health and wellness control arm (n = 52) at mean = 11.9 weeks gestation. Physical activity was assessed via the Pregnancy Physical Activity Questionnaire (PPAQ). RESULTS: After the 12-week intervention, the exercise arm experienced a smaller decrease (-1.0 MET-hrs/wk) in total activity vs. the control arm (-10.0 MET-hrs/wk; P = .03), and a higher increase in sports/exercise (0.9 MET-hrs/wk) vs. the control arm (-0.01 MET-hrs/wk; P = .02). Intervention participants (95%) reported being satisfied with the amount of information received and 86% reported finding the study materials interesting and useful. CONCLUSIONS: Findings support the feasibility and preliminary efficacy of a tailored exercise intervention in increasing exercise in a diverse sample of pregnant women.

Predicting low dose effects for chemicals in high through-put studies.

High through-put studies commonly use automated systems with 96-well plates in which multiple chemicals are tested at multiple doses using log-2 dose increments after a suitable incubation period. There are typically multiple (ranging from five to eleven) doses on each chemical, and occasionally plate replications of the dose-response studies. The target endpoint for such studies is typically the LC50, but for some chemicals, there may be multiple doses below a benchmark dose where there is no apparent adverse response relative to control response. We show how an estimation approach can lead to clearly interpretable results about response in the low dose region using data from a high throughput study of 2189 chemicals on yeast. Accurate estimates can be obtained of response for study chemicals by using best linear unbiased predictors (BLUPs) in a mixed model, and summarized via plots with expected response (assuming no low-dose effect) with confidence intervals for response below the benchmark dose for each chemical, providing an informative summary of response at low doses. We conclude that this approach can provide valuable insights that would be missed if the observational data were only considered through the lens of statistical methods appropriate for experimental studies.