CONTROL OF STREAMBANK EROSION DUE TO BED DEGRADATION WITH VEGETATION AND STRUCTURE1

ABSTRACT: Combinations of vegetation and structure were applied to control streambank erosion along incised stream channels in northwest Mississippi. Eleven sites along seven channels with contributing drainage areas ranging from 12–300 km² were used for testing. Tested configurations included eroding banks protected by vegetation alone, vegetation with structural toe protection, vegetation planted on re-graded banks, and vegetation planted on regraded banks with toe protection. Monitoring continued for up to 10 years, and casual observation for up to 18 years. Sixteen woody and 13 nonwoody species were tested. Native woody species, particularly willow, appear to be best adapted to stream-bank environments. Sericea lespedeza and Alamo switchgrass were the best nonwoody species tested. Vegetation succeeded in reaches where the bed was not degrading, competition from kudzu was absent, and bank slopes were stabilized by grading or toe protection. Natural vegetation invaded planted and unplanted stable banks composed of fertile soils. Designs involving riprap toe protection in the form of a longitudinal dike and woody vegetation appeared to be most cost-effective. The exotic vine kudzu presents perhaps the greatest long-term obstacle to restoring stable, functional riparian zones along incised channels in our region. (KEY TERMS: vegetation; streambank protection; bioengineering; stream restoration; channel incision; riparian zone.)     

Prenatal sonographic diagnosis of meconium peritonitis

The ultrasonographer may be the first physician to suggest the presence of a fetal abnormality. A case of prenatally-detected meconium peritonitis is presented, with sonographic and radio-graphic correlation.     

Local vs. national: Epidemiology of pedestrian injury in a mid-Atlantic city

Objective: Understanding pedestrian injury trends at the local level is essential for program planning and allocation of funds for urban planning and improvement. Because we hypothesize that local injury trends differ from national trends in significant and meaningful ways, we investigated citywide pedestrian injury trends to assess injury risk among nationally identified risk groups, as well as identify risk groups and locations specific to Baltimore City.

Methods: Pedestrian injury data, obtained from the Baltimore City Fire Department, were gathered through emergency medical services (EMS) records collected from January 1 to December 31, 2014. Locations of pedestrian injuries were geocoded and mapped. Pearson's chi-square test of independence was used to investigate differences in injury severity level across risk groups. Pedestrian injury rates by age group, gender, and race were compared to national rates.

Results: A total of 699 pedestrians were involved in motor vehicle crashes in 2014—an average of 2 EMS transports each day. The distribution of injuries throughout the city did not coincide with population or income distributions, indicating that there was not a consistent correlation between areas of concentrated population or concentrated poverty and areas of concentrated pedestrian injury. Twenty percent (n = 138) of all injuries occurred among children age ≤14, and 22% (n = 73) of severe injuries occurred among young children. The rate of injury in this age group was 5 times the national rate (Incident Rate Ratio [IRR] = 4.81, 95% confidence interval [CI], [4.05, 5.71]). Injury rates for adults ≥65 were less than the national average.

Conclusions: As the urban landscape and associated pedestrian behavior transform, continued investigation of local pedestrian injury trends and evolving public health prevention strategies is necessary to ensure pedestrian safety.     

CHEMICAL PRECIPITATION-COAGULATION FOR ORGANIC COLOR REMOVAL FROM GOUNDWATERS1

ABSTRACT: Many wells produce water that is highly colored by organic substances. Colored water may cause aesthetic, economic, and health problems for the cities using it as a municipal supply. Characterization of water from a number of wells showed that the color causing compounds were hydroxylated aromatic carboxylic acids which were precipitated below pH 4.5 and were almost completely ionized above pH 4.5. Through jar tests, a chemical precipitation-coagulation treatment system was developed. The optimal sequence of chemical addition was alum first, followed by pH adjustment and addition of a polyelectrolyte. Rapid mix tests demonstrated the need for a reaction period after alum and after acid addition, and that the rapid mix time controlled floc size for a given flocculation period. Flocculation tests, varying both the floc time and mean velocity gradient, G, showed that an optimum G exists for each floc time and that the residual color decreased with decreasing values of velocity gradient.     

Fetal renal vein thrombosis,hydrops fetalis,and maternal lupus anticoagulant. A case report

Hydrops fetalis with fetal renal vein thrombosis in a mother with antiphospholipid antibody syndrome detected post-partum suggests an underlying pathogenetic association that may provide new strategies for treatment of a lethal disorder.     

Motivating children's cooperation to conserve forests

Forests are essential common-pool resources. Understanding children's and adolescents’ motivations for conservation is critical to improving conservation education. In 2 experiments, we investigated 1086 school-aged children and adolescents (6–16 years old) from the United States, China, and the Democratic Republic of Congo. Testing participants in groups, we assessed their motivation for conservation based on collective-risk common-pool goods games in which they were threatened with losing their endowment unless the group donation exceeded a threshold needed to maintain the forest. Extrinsic motivations, rather than intrinsic, tended to lead to successful cooperation to maintain a forest. Certainty of losing individual payoffs significantly boosted successful cooperative conservation efforts across cultures (success rates were 90.63% and 74.19% in the 2 risk-extrinsic conditions, and 43.75% in the control condition). In U.S. participants, 2 extrinsic incentives, priming discussions of the value of forests and delay of payoffs as punishment, also increased success of cooperative conservation (success rates were 97.22% and 76.92% in the 2 extrinsic-incentive conditions, and 29.19% and 30.77% in the 2 control conditions). Conservation simulations, like those we used, may allow educators to encourage forest protection by leading groups to experience successful cooperation and the extrinsic incentives needed to motivate forest conservation.