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

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

Analysis of the third national health and nutrition examination survey (NHANES III) using expert ratings of job categories

Background Few epidemiologic studies have addressed the exposure–response relationships between work activities and symptomatic knee osteoarthritis (OA). This analysis used data from a national survey and ergonomists' ratings to address this issue. Methods Interview and knee X-ray data were obtained from the Third National Health and Nutrition Examination Survey. Occupational ratings were obtained using ergonomists. A weighted logistic regression was used. Results Among men, a significant exposure–response relationship was found between symptomatic knee OA and kneeling. In both genders, there was a significant trend in heavy lifting and severe symptomatic knee OA. Approximately 20.7% of knee OA can be attributed to kneeling >14% of the workday among men. Conclusions The significant exposure–response relationships suggest that modest reductions in certain occupational activities can reduce the burden of knee OA. The study was limited by unvalidated expert ratings. Research is needed to identify hazardous characteristics of work activities and to clarify exposure–response relationships. Am. J. Ind. Med. 51:37–46, 2008. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57516/1/20512_ftp.pd

Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers

Stress reduction through contact with nature is well established, but far less is known about the contribution of contact parameters – duration, frequency, and nature quality. This study describes the relationship between duration of a nature experience (NE), and changes in two physiological biomarkers of stress – salivary cortisol and alpha-amylase. It is the first study to employ long-term, repeated-measure assessment and the first evaluation wherein study participants are free to choose the time of day, duration, and the place of a NE in response to personal preference and changing daily schedules. During an 8-week study period, 36 urban dwellers were asked to have a NE, defined as spending time in an outdoor place that brings a sense of contact with nature, at least three times a week for a duration of 10 min or more. Their goal was compliance within the context of unpredictable opportunity for taking a nature pill. Participants provided saliva samples before and after a NE at four points over the study period. Before-NE samples established the diurnal trajectory of each stress indicator and these were in line with published outcomes of more closely controlled experiments. For salivary cortisol, an NE produced a 21.3%/hour drop beyond that of the hormone’s 11.7% diurnal drop. The efficiency of a nature pill per time expended was greatest between 20 and 30 min, after which benefits continued to accrue, but at a reduced rate. For salivary alpha-amylase, there was a 28.1%/h drop after adjusting for its diurnal rise of 3.5%/h, but only for participants that were least active sitting or sitting with some walking. Activity type did not influence cortisol response. The methods for this adaptive management study of nature-based restoration break new ground in addressing some complexities of measuring an effective nature dose in the context of normal daily life, while bypassing the limitations of a clinical pharmacology dose–response study. The results provide a validated starting point for healthcare practitioners prescribing a nature pill to those in their care. This line of inquiry is timely in light of expanding urbanization and rising healthcare costs

Interleukin-8 levels and activity in delayed-healing human thermal wounds

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72020/1/j.1524-475x.2000.00216.x.pd

Kidney transplant graft outcomes in 379 257 recipients on 3 continents

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/1/ajt14694_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/2/ajt14694.pd

A new outcome measure for LUTS: Symptoms of Lower Urinary Tract Dysfunction Research Network Symptom Index‐29 (LURN SI‐29) questionnaire

AimsTo develop a representative, self‐report assessment of lower urinary tract symptoms (LUTS) for men and women, the symptoms of Lower Urinary Tract Dysfunction Research Network Symptom Index‐29 (LURN SI‐29).MethodsWomen and men seeking treatment for LUTS at one of six academic medical centers in the US were assessed at baseline, 3‐month and 12‐month intervals. Twelve‐month data on 78 LURN SI‐29 items were analyzed among 353 women and 420 men using exploratory factor analysis (EFA), with factor structure confirmed using confirmatory factor analysis (CFA). Internal consistency, reliability, and validity of the five developed scales were evaluated by assessing correlations with the American Urological Association Symptom Index (AUA‐SI), the genitourinary pain index (GUPI), and the Pelvic Floor Distress Inventory‐20 (PFDI‐20), and by examining expected sex differences in scores.ResultsEFA results (n = 150 women; 150 men) produced an interpretable eight‐factor solution, with three of the factors comprised of dichotomous items addressing LUTS‐associated sensations. The remaining five factors, confirmed with CFA in an independent sample of 473 participants, produced five scales: incontinence, urgency, voiding difficulty, bladder pain, and nocturia. Subscales and total LURN SI‐29 scores were correlated as expected with AUA‐SI, GUPI, and PFDI‐20. LURN SI‐29 scores also performed as expected in differentiating men from women based upon clinically expected differences, with men reporting more voiding difficulties and nocturia, and women reporting more urgency and incontinence.ConclusionsThe LURN SI‐29 questionnaire has the potential to improve research and clinical outcome measurement for both men and women with LUTS.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150585/1/nau24067.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150585/2/nau24067_am.pd

Liver regeneration after living donor transplantation: Adult‐to‐adult living donor liver transplantation cohort study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109827/1/lt23966.pd