Measuring the Lifetime Experience of Domestic Violence: Application of the Life History Calendar Method

In the absence of a gold standard, research on domestic violence relies primarily on self-report, the quality of which is known to decline as the length of the recall period increases. Eliciting valid and reliable self-report data is crucial to the development of prevention and intervention policies and services. Nevertheless, existing measures typically do not incorporate devices to facilitate respondents\u27 recall of the lifetime experience of domestic violence. This article describes the application of the Life History Calendar (LHC) method (Freedman, Thornton, Camburn, Alwin, & Young-DeMarco, 1988) to increase a respondent\u27s recall of domestic violence victimization over the lifecourse. The LHC method elicits memorable information of a personal nature (e.g., children\u27s birth dates) and uses this information to facilitate the recall of less memorable events. A recent field test of this LHC measure indicates its utility in assessing domestic violence victimization, which takes place in a complex sequence of episodes and often involves multiple perpetrators over the lifecourse

Estimating Half-Lives for Pesticide Dissipation from Plants

Pesticide risk and impact assessment models critically rely on and are sensitive to information describing dissipation from plants. Despite recent progress, experimental data are not available for all relevant pesticide–plant combinations, and currently no model predicting plant dissipation accounts for the influence of substance properties, plant characteristics, temperature, and study conditions. In this study, we propose models to estimate half-lives for pesticide dissipation from plants and provide recommendations for how to use our results. On the basis of fitting experimental dissipation data with reported average air temperatures, we estimated a reaction activation energy of 14.25 kJ/mol and a temperature coefficient <i>Q</i>₁₀ of 1.22 to correct dissipation from plants for the influence of temperature. We calculated a set of dissipation half-lives for 333 substances applied at 20 °C under field conditions. Half-lives range from 0.2 days for pyrethrins to 31 days for dalapon. Parameter estimates are provided to correct for specific plant species, temperatures, and study conditions. Finally, we propose a predictive regression model for pesticides without available measured dissipation data to estimate half-lives based on substance properties at the level of chemical substance class. Estimated half-lives from our study are designed to be applied in risk and impact assessment models to either directly describe dissipation or as first proxy for describing degradation

Recall of age of weaning and other breastfeeding variables

BACKGROUND: Many studies of the impact of breastfeeding on child or maternal health have relied on data reported retrospectively. The goal of this study was to assess recall accuracy among breastfeeding mothers of retrospectively collected data on age of weaning, reasons for cessation, breast pain, lactation mastitis, and pumping. METHODS: Women in Michigan and Nebraska, U.S.A. were interviewed by telephone every 3 weeks during the first 3 months after the birth of their child, and mailed a questionnaire at 6 months. A subset was interviewed again by telephone approximately 1–3.5 years after the birth. The results for the three recall periods, collected 1994–1998, were compared using correlation, linear and Cox regression analysis, and sensitivity and specificity estimates. RESULTS: The 184 participants were aged 18–42, mostly white (95%) and 63% had an older child. The age of weaning tended to be overestimated in interviews 1–3.5 years after birth compared to those within 3 weeks of the event, by approximately one month for 1–3.5 year recall and two weeks for 6-month recall (p < 0.001 in both cases). Recall accuracy of reasons for weaning varied greatly by reason, with mastitis and return to work having the most recall validity. The sensitivity of 1–3.5 year recall of mastitis was 80%, but was only 54% for nipple cracks or sores. CONCLUSION: Breastfeeding duration among short-term breastfeeders tended to be somewhat overestimated when measured at 1–3.5 years post-partum. Reporting of other breastfeeding characteristics had variable reliability. Studies employing retrospective breastfeeding data should consider the possibility of such errors

How to measure reproductive success?

To date there have been few empirical comparisons between alternative methods for measuring reproductive success (RS). We consider the pros and cons of alternative measures of RS to provide guidance for the design of field studies in human behavioral ecology. We compare cross-sectional measures that count offspring alive at the time of the interview and retrospective measures that require data on offspring age at death or censoring. We consider analyses that include adult women (yielding age-specific estimates of RS) as well as analyses restricted to postreproductive women (yielding data on lifetime RS). These methods are applied to reproductive data for the Dogon of Mali, West Africa. Am. J. Hum. Biol. 15:361–369, 2003. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35101/1/10154_ftp.pd

Relationship of estimated dietary intake of n-3 polyunsaturated fatty acids from fish with peripheral nerve function after adjusting for mercury exposure

BACKGROUND: Some clinical studies have suggested that ingestion of n-3 polyunsaturated fatty acids (PUFA) has neuroprotective effects on peripheral nerve function. However, few epidemiological studies have examined the effect of dietary n-3 PUFA intake from fish consumption on peripheral nerve function, and none have controlled for co-occurrence of methylmercury exposure from fish consumption. OBJECTIVES: We evaluated the effect of estimated dietary n-3 PUFA intake on peripheral nerve function after adjusting for biomarkers of methylmercury and elemental mercury in a convenience sample of 515 dental professionals. METHODS: We measured sensory nerve conduction (peak latency and amplitude) of the median, ulnar and sural nerves and total mercury concentrations in hair and urine samples. We estimated daily intake (mg/day) of the total n-3 PUFA, n-3 docosahexaenoic acid (DHA), and n-3 eicosapentaenoic acid (EPA) based on a self-administrated fish consumption frequency questionnaire. We also collected information on mercury exposure, demographics and other covariates. RESULTS: The estimated median intakes of total n-3 PUFA, n-3 EPA, and n-3 DHA were 447, 105, and 179 mg/day, respectively. The mean mercury concentrations in urine (1.05 μg/L) and hair (0.49 μg/g) were not significantly different from the US general population. We found no consistent association between n-3 PUFA intake and sensory nerve conduction after adjusting for mercury concentrations in hair and urine although some positive associations were observed with the sural nerve. CONCLUSIONS: In a convenience sample of dental professionals, we found little evidence suggesting that dietary intake of n-3 PUFAs from fish has any impact on peripheral nerve function after adjustment for methylmercury exposure from fish and elemental mercury exposure from dental amalgam

Glutathione Enzyme and Selenoprotein Polymorphisms Associate with Mercury Biomarker Levels in Michigan Dental Professionals

Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione S-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n=515), and total mercury content was measured. Average urine (1.06±1.24 microg/L) and hair mercury levels (0.49±0.63 microg/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5'), or both (SEPP1 3'UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption)

Methylmercury and elemental mercury differentially associate with blood pressure among dental professionals

Methylmercury-associated effects on the cardiovascular system have been documented though discrepancies exist, and most studied populations experience elevated methylmercury exposures. No paper has investigated the impact of low-level elemental (inorganic) mercury exposure on cardiovascular risk in humans. The purpose of this study was to increase understanding of the association between mercury exposure (methylmercury and elemental mercury) and blood pressure measures in a cohort of dental professionals that experience background exposures to both mercury forms. Dental professionals were recruited during the 2010 Michigan Dental Association Annual Convention. Mercury levels in hair and urine samples were analyzed as biomarkers of methylmercury and elemental mercury exposure, respectively. Blood pressure (systolic, diastolic) was measured using an automated device. Distribution of mercury in hair (mean, range: 0.45, 0.02–5.18 μg/g) and urine (0.94, 0.03–5.54 μg/L) correspond well with the US National Health and Nutrition Examination Survey. Linear regression models revealed significant associations between diastolic blood pressure (adjusted for blood pressure medication use) and hair mercury (n = 262, p = 0.02). Urine mercury results opposed hair mercury in many ways. Notably, elemental mercury exposure was associated with a significant systolic blood pressure decrease (n = 262, p = 0.04) that was driven by the male population. Associations between blood pressure and two forms of mercury were found at exposure levels relevant to the general population, and associations varied according to type of mercury exposure and gender

An Investigation of Modifying Effects of Single Nucleotide Polymorphisms in Metabolism-related Genes on the Relationship between Peripheral Nerve Function and Mercury Levels in Urine and Hair

Mercury (Hg) is a potent neurotoxicant. We hypothesized that single nucleotide polymorphisms (SNPs) in genes coding glutathione-related proteins, selenoproteins and metallothioneins may modify the relationship of mercury biomarkers with changes in peripheral nerve function. Dental professionals (n=515) were recruited in 2009 and 2010. Sensory nerve function (onset latency, peak latency and amplitude) of the median, ulnar and sural nerves was recorded. Samples of urine, hair and DNA were collected. Covariates related to demographics, nerve function and elemental and methyl-mercury exposure were also collected. Subjects included 244 dentists (47.4%) and 269 non-dentists (52.2%; mostly dental hygienists and dental assistants). The mean mercury levels in urine (1.06 μg/L) and hair (0.51 μg/g) were not significantly different from the US general population (0.95 μg/L and 0.47 μg/g, respectively). In multivariate linear models predicting nerve function adjusting for covariates, only 3 out of a total of 504 models showed stable and statistically significant interaction of SNPs with mercury biomarkers. Overall, given the possibility of false positives, the results suggested little evidence of effect modification of the SNPs on the relationship between mercury biomarkers with peripheral nerve function at exposure levels that are relevant to the general US population

An Investigation of Modifying Effects of Metallothionein Single-Nucleotide Polymorphisms on the Association between Mercury Exposure and Biomarker Levels

Background: Recent studies have suggested that several genes that mediate mercury metabolism are polymorphic in humans

Major depressive disorder in a family study of obsessive–compulsive disorder with pediatric probands

Objective: This study examined the comorbidity of obsessive–compulsive disorder (OCD) with major depressive disorder (MDD) in a family study of OCD with pediatric probands. Method: This study assessed the lifetime prevalence of MDD in 141 first‐degree relatives (FDR) and 452 second‐degree relatives (SDR) of pediatric probands with OCD and healthy controls, and identified variables associated with MDD in case FDR. All available FDR were directly interviewed blind to proband status; parents were also interviewed to assess the family psychiatric history of FDR and SDR. Best‐estimate diagnoses were made using all sources of information. Data were analyzed with logistic regression and robust Cox regression models. Results: Lifetime MDD prevalence was significantly higher in case than in control FDR (30.4 versus 15.4%). Lifetime MDD prevalence was significantly higher in FDR of case probands with MDD than in FDR of case probands without MDD or control FDR (46.3 versus 19.7 versus 15.4%, respectively). MDD in case FDR was significantly associated with MDD in case probands and with age and OCD in those relatives. Lifetime MDD prevalence was similar in case and control SDR. However, lifetime MDD prevalence was significantly higher in SDR of case probands with MDD than in SDR of case probands without MDD or control SDR (31.9 versus 16.8 versus 15.4%, respectively). Conclusions: MDD prevalence was significantly higher in both FDR and SDR of case probands with MDD than in relatives of case probands without MDD or control relatives, suggesting that pediatric OCD comorbid with MDD is a complex familial syndrome. Depression and Anxiety, 2011. © 2011 Wiley‐Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87090/1/20824_ftp.pd