Biomedical subjects

J J Sloan

Publications and source records attributed to J J Sloan.

7 recordsLinked to original sources

PubMed2006

Temperature-dependent complex indices of refraction for crystalline (NH(4))(2)SO(4).

We present a significantly improved set of complex indices of refraction (optical constants) for crystalline (NH(4))(2)SO(4) at 298 K, determined from extinction spectra measured in an aerosol flow tube (AFT). The improved values provide more accurate reproductions of experimental extinction spectra when used in light scattering calculations (Mie, T-matrix, etc.). Optical constants were also derived from measurements using a cryogenic AFT at 243, 223, and 213 K, temperatures characteristic of the upper troposphere and stratosphere. Only minor changes in the optical constants were observed down to 223 K, the transition temperature to the ferroelectric phase, after which significant changes were observed. Here we report the first complex indices of refraction at reduced temperatures for both phases of crystalline (NH(4))(2)SO(4).

Journal Article↗

PubMed2005

Frequency dependent complex refractive indices of supercooled liquid water and ice determined from aerosol extinction spectra.

Complex refractive indices of supercooled liquid water at 240, 253, 263, and 273 K, and ice at 200, 210, and 235 K in the mid infrared from 460 to 4000 cm(-1) are reported. The results were obtained from the extinction spectra of small (micron-size) aerosol particles, recorded using the cryogenic flow tube technique. An improved iterative procedure for retrieving complex refractive indices from extinction measurements is described. The refractive indices of ice determined in the present study are in good agreement with data reported earlier. The temperature region and range of states covered in the present work are relevant to the study of upper tropospheric and stratospheric aerosols and clouds.

Journal Article↗

PubMed1996

Has awareness of the alcohol warning label reached its upper limit?

Has awareness of the alcoholic beverage warning label reached its maximum? This study tracks changes in the level of awareness among a sample of 7334 inner-city African-American gravidas seeking prenatal care between May 1989 and June 1993. Previously, we found that a significant increase in awareness of the warning label occurred in March 1990. In the current analysis over a 50-month period, the level of awareness continued to increase through December 1992 and then leveled off, suggesting a negatively accelerated growth function. The logistic function fitted to the awareness curve predicts that the upper limit of awareness in this population has been reached (the predicted upper limit being 81.5%). In addition a logit regression analysis showed that women who did not know about the warning label were more likely to be over 29 years of age. Heavier drinkers were 1.25 times more likely to be aware of the label. Among those drinkers who were not aware of the label, 30% drank at both conception and antenally, thus putting their fetus at high risk for alcohol-related birth defects.

Adult↗

PubMed1996

Heeding the alcoholic beverage warning label during pregnancy: multiparae versus nulliparae.

OBJECTIVE: We compared the impact of the Federal Alcoholic Beverage Warning Label on multiparae (women with at least one previous live birth) and nulliparae (women with no previous live births). The label, implemented on November 18, 1989, urges women not to drink during pregnancy because of the risk of birth defects. If multiparae drank during prior pregnancies, delivering apparently normal babies, we hypothesized that the warning might be less salient for them. METHOD: We studied 17,456 inner city black gravidas seen between September 1986 and September 1993 at one antenatal clinic. Time series analysis (ARIMA) examined trends in monthly means of antenatal drinking scores (alcohol consumption adjusted for weeks' gestation, age, parity and periconceptional drinking). RESULTS: For nulliparae (n = 7,349), reported drinking began to show a significant decline in June 1990, 7 months after the implementation of the warning label (t = 2.00, p < .04). In contrast, multiparae (n = 10,107) showed no change in reported drinking (t = 1.23) postlabel. CONCLUSIONS: Given previous results that multiparae drink more and that heavier drinkers are ignoring the warning label, these data are very distressing and suggests the importance of targeting multiparae for intensive prevention efforts.

Adolescent↗

PubMed1993

A time series analysis of the impact of the alcohol warning label on antenatal drinking.

In a sample of over 12,000 African-American gravidas, we tested the hypothesis that the Federal Beverage Labeling Act of 1988 has decreased antenatal drinking. Results of time series analysis indicated a 7-month lag in the impact of the alcohol warning label. Controlling for population changes, antenatal drinking began to fall as of June 1990. However, this decrease was small in size and did not impact on the heaviest drinkers. Seasonal trends in drinking were also detected, with peaks around the end of the year and the summer.

Adult↗

PubMed1993

The alcohol beverage warning label: when did knowledge increase?

This article presents data on the awareness of the alcohol beverage warning label among a sample of 5,169 inner city African-American gravidas seeking prenatal care. While the label law was implemented in November 1989, a significant increase in knowledge of the label did not occur until March 1990. Women who predominantly consumed wine coolers and beer, and those under age 30 were more likely to know about the label than their counterparts.

Adult↗

PubMedDate not supplied

Distribution of mercury in soil and its concentration in runoff from a biosolids-amended agricultural watershed.

Biosolids applications can significantly increase Hg concentrations in cultivated soils. The objective of this study was to quantify levels of mercury in soils and runoff from a biosolids-amended watershed. The study site was a terraced, cultivated watershed that received cumulative biosolids loadings of 0, 87, or 224 Mg ha(-1) between 1974 and 1993. Snowmelt runoff samples were collected from the three treatment areas in the spring of 1995. Soils were collected along transects from the 0 and 224 Mg ha(-1) biosolids treatment areas at depths of 0 to 15 and 15 to 30 cm. Mercury analysis of stored, freeze-dried biosolids samples showed that Hg concentrations during the 20-year study ranged from 12.4 mg kg(-1) initially to 2.4 mg kg(-1) near the end. Soil Hg concentrations were elevated in the surface (0-15 cm) and subsurface (15-30 cm) of the 224 Mg ha(-1) biosolids-treated terrace relative to the control. Mercury concentrations in the 0- to 15-cm soil depth ranged from 30 to 50 microg kg(-1) for the control terrace and 180 to 390 microg kg(-1) for the 224 Mg ha(-1) biosolids-treated terrace. Concentrations were lower in the 15- to 30-cm depth. Total Hg concentrations in snowmelt from the control terrace ranged from 9.2 to 27.9 ng L(-1) and 19.8 to 44.8 ng L(-1) for the biosolids-treated terraces. Most Hg was associated with particulates > 0.45 microm. Mercury concentrations were elevated in grass tissue growing near the watershed's runoff lagoon.

Agriculture↗