Prenatal ultrasonographic diagnosis of congenital megalourethra

Congenital megalourethra is a rare genital anomaly characterized by dilatation of the penile urethra without evidence of distal obstruction. Reports of the prenatal diagnosis of this condition in the literature are limited. We present a case of congenital megalourethra with obstructive uropathy from the posterior urethra diagnosed prenatally at 18 weeks of gestation. ‘Prune-belly’-like features, colonic malrotation, and imperforate anus were also found on autopsy.     

Analysis of herbicide Krovar I by liquid chromatography with atmospheric pressure chemical ionization mass spectrometry

A simple, very efficient method is presented for routine analysis of herbicide Krovar I (active components bromacil and diuron) in water and soil samples. Water samples were extracted by liquid-liquid extraction with dichloromethane (DCM) as extraction solvent. For soil samples two different extraction techniques were compared: microwave-assisted solvent extraction and a shaking technique using a platform shaker. Extracts were analyzed by high performance liquid chromatography using a water:methanol gradient. Liquid chromatography was coupled with atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) for quantification of bromacil and diuron. Optimization of the APCI-MS was done by using standards in the flow injection analysis mode (FIA). Method detection limit for liquid samples for bromacil is 0.04 microg L(-1) and for diuron 0.03 microg L(-1). Method detection limit for soil samples is 0.01 microg g(-1) dry weight for both compounds. Results of analysis of field samples of water and soil are also presented.     

Volatility of propoxur from different surface materials commonly found in homes

The purpose of this study was to determine the volatilization rates of propoxur from different surface materials commonly found in homes, and to conduct field measurements under ventilated and non-ventilated conditions. Since it is known that temperature, humidity and constant air flow most significantly affect volatility, various surface materials were sprayed using a constant amount of propoxur under the controlled conditions of an exposure chamber. Acetonitrile was used to desorb both XAD-2 resin that collected airborne propoxur and surface materials containing propoxur residue. HPLC was used to analyze propoxur concentrations. Based on multiple regression models, temperature most significantly affected volatility, followed by humidity. Volatilization rates of propoxur were highest from quartz surfaces and lowest from glass. Interaction was most readily found on glass surfaces based on humidity-air flow and humidity-temperature factors. In field applications, propoxur was sprayed in a room under two conditions with ventilation and without in order to measure the concentrations of propoxur in the air and on a quartz surface. Findings showed both airborne and settled concentrations peaked after a half hour then decreased under both conditions, both more sharply in the ventilated room. Under both conditions, no propoxur was detected on the quartz surface after three and a half hours but airborne concentrations remained detectable after thirty-three and one half hours. We conclude that to maintain good air quality, ventilation is important and special care must be taken when spraying insecticides on different surfaces.     

Within-year differences in reproductive investment in laboratory zebra finches (<Emphasis Type="Italic">Taeniopygia guttata</Emphasis>), an opportunistically breeding bird

Reproduction in opportunistically breeding bird species has traditionally been considered non-seasonal with individuals taking advantage of favourable environmental conditions as they arise. However, some studies imply that this opportunistic breeding may be superimposed on an underlying seasonality, which has effects on the readiness to breed when conditions are favourable. The zebra finch (Taeniopygia guttata) is the classic opportunistic breeder and widely used as such in studies. In a series of laboratory-based breeding experiments, we found evidence to suggest that there are seasonal differences in maternal reproductive investment in the zebra finch even when photoperiod, temperature, relative humidity and diet were held constant. Females showed highly significant seasonal differences in clutch size and egg mass with laying order. Clutch size showed a spring/summer peak typical of multi-brooded species in the wild. There was also a significant increase in egg mass with laying order in all seasons except winter. This variation in breeding parameters with season may allow females to adjust investment depending on the potential fitness returns from a given reproductive attempt. These findings also raise a warning about interpreting results of multiple zebra finch breeding experiments that have been carried out in different seasons.     

Repeatability study of replicate crash tests: A signal analysis approach

Objective: To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods.

Methods: Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability.

Results: Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X′ (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures.

Conclusions: Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test protocols.     

Comparison of RBCA and CalTOX for setting risk-based cleanup levels based on inhalation exposure

Risk-based corrective action (RBCA) and CalTOX (California EPA) are often used to develop risk-based soil cleanup levels. The determination of the entry parameters, including slope factors, degradation assumption, methodologies, and dispersion models for these two approaches greatly affect the onsite/offsite cleanup levels, risk distribution, and ranking of the influential factors. The subsurface soil-to-ambient air was considered as the only significant exposure pathway in this study. RBCA and CalTOX apply analytical equations and multimedia fugacity model, respectively, to simulate the transport of contaminants from subsurface soil to ambient air. Nine carcinogenic organic contaminants were selected as the target compounds. Environmental monitoring data collected from a contaminated site in southern Taiwan was used as model inputs. In this study, degradation assumption had greater influence on CalTOX evaluation than slope factors. The cleanup soil levels of all target chemicals developed by both models were close under the same slope factors and degradation assumptions, except for vinyl chloride and hexachlorobenzene. Furthermore, RBCA generally had larger offsite dispersion ratios than CalTOX, especially for long distances. The risk distribution obtained by RBCA was much board than by CalTOX. When 95th percentile was considered as the starting point, the SSTLs derived by RBCA were much stricter than by CalTOX. The ranking of influential factors in the onsite risk assessment for these two models were completely different because of their distinct model methodologies.     

Indirect upstream effects of dams: consequences of migratory consumer extirpation in Puerto Rico.

Large dams degrade the integrity of a wide variety of ecosystems, yet direct downstream effects of dams have received the most attention from ecosystem managers and researchers. We investigated indirect upstream effects of dams resulting from decimation of migratory freshwater shrimp and fish populations in Puerto Rico, USA, in both high- and low-gradient streams. In high-gradient streams above large dams, native shrimps and fishes were extremely rare, whereas similar sites without large dams had high abundances of native consumers. Losses of native fauna above dams dramatically altered their basal food resources and assemblages of invertebrate competitors and prey. Compared to pools in high-gradient streams with no large dams, pool epilithon above dams had nine times more algal biomass, 20 times more fine benthic organic matter (FBOM), 65 times more fine benthic inorganic matter (FBIM), 28 times more carbon, 19 times more nitrogen, and four times more non-decapod invertebrate biomass. High-gradient riffles upstream from large dams had five times more FBIM than did undammed riffles but showed no difference in algal abundance, FBOM, or non-decapod invertebrate biomass. For epilithon of low-gradient streams, differences in basal resources between pools above large dams vs. without large dams were considerably smaller in magnitude than those observed for pools in high-gradient sites. These results match previous stream experiments in which the strength of native shrimp and fish effects increased with stream gradient. Our results demonstrate that dams can indirectly affect upstream free-flowing reaches by eliminating strong top-down effects of consumers. Migratory omnivorous shrimps and fishes occur throughout the tropics, and the consequences of their declines upstream from many tropical dams are likely to be similar to those in Puerto Rico. Thus, ecological effects of migratory fauna loss upstream from dams encompass a wider variety of species interactions and biomes than the bottom-up effects (i.e., elimination of salmonid nutrient subsidies) recognized for northern temperate systems.     

Anthropogenic Correlates of Species Richness in Southeastern Ontario Wetlands

We examined the relationship between the richness of four different wetland taxa (birds, mammals, herptiles, and plants) in 30 southeastern Ontario, Canada wetlands and two anthropogenic factors: road construction and forest removal/conversion on adjacent lands. Data were obtained from two sources: road densities and forest cover from 1:50,000 Government of Canada topographic maps and species lists and wetland areas from Ontario Ministry of Natural Resources wetland evaluation reports. Multiple regression analysis was used to model the relationships between species richness and wetland area, road density, and forest cover. Our results show a strong positive relationship between wetland area and species richness for all taxa. The species richness of all taxa except mammals was negatively correlated with the density of paved roads on lands up to 2 km from the wetland. Furthermore, both herptile and mammal species richness showed a strong positive correlation with the proportion of forest cover on lands within 2 km. These results provide evidence that at the landscape level, road construction and forest removal on adjacent lands pose significant risks to wetland biodiversity. Furthermore, they suggest that most existing wetland policies, which focus almost exclusively on activities within the wetland itself and/or a narrow buffer zone around the wetland perimeter, are unlikely to provide adequate protection for wetland biodiversity.     

Repeatability of a dynamic rollover test system

Objective: The goal of this study was to characterize the rollover crash and to evaluate the repeatability of the Dynamic Rollover Test System (DRoTS) in terms of initial roof-to-ground contact conditions, vehicle kinematics, road reaction forces, and vehicle deformation.

Methods: Four rollover crash tests were performed on 2 pairs of replicate vehicles (2 sedan tests and 2 compact multipurpose van [MPV] tests), instrumented with a custom inertial measurement unit to measure vehicle and global kinematics and string potentiometers to measure pillar deformation time histories. The road was instrumented with load cells to measure reaction loads and an optical encoder to measure road velocity. Laser scans of pre- and posttest vehicles were taken to provide detailed deformation maps.

Results: Initial conditions were found to be repeatable, with the largest difference seen in drop height of 20 mm; roll rate, roll angle, pitch angle, road velocity, drop velocity, mass, and moment of inertia were all 7% different or less. Vehicle kinematics (roll rate, road speed, roll and pitch angle, global Z′ acceleration, and global Z′ velocity) were similar throughout the impact; however, differences were seen in the sedan tests because of a vehicle fixation problem and differences were seen in the MPV tests due to an increase in reaction forces during leading side impact likely caused by disparities in roll angle (3° difference) and mass properties (2.2% in moment of inertia [MOI], 53.5 mm difference in center of gravity [CG] location).

Conclusions: Despite those issues, kinetic and deformation measures showed a high degree of repeatability, which is necessary for assessing injury risk in rollover because roof strength positively correlates with injury risk (Brumbelow 2009). Improvements of the test equipment and matching mass properties will ensure highly repeatable initial conditions, vehicle kinematics, kinetics, and deformations.     

In Situ Solidification (ISS) of River Sediments: Pilot Demonstration and Discussion of ISS as a Remedial Alternative to Dredging and Capping

In situ solidification (ISS) is a proven technology for remediation of upland site soils, but has not been thoroughly demonstrated for use in impacted underwater sediments. This article describes the first successful use of ISS techniques to solidify underwater sediments containing manufactured gas plant non‐aqueous‐phase liquid (NAPL). The techniques consisted of mixing cementitious grout with the sediments in situ to create a monolith that immobilized the contaminants, significantly decreased the hydraulic conductivity, and also vastly decreased contaminant leaching potential of the sediments. The success of this pilot demonstration project suggests that ISS may be a viable alternative for: sites requiring deep dredging; large volume projects on urban waterways where staging and amending areas are limited; sites with NAPL impacts that cannot be controlled during dredging; and sites where eventual NAPL breakthrough is anticipated if reactive caps are employed. The potential economic, environmental, and operational benefits of this technology will be discussed. This article focuses on the primary objectives of the pilot demonstration: to meet quantitative performance criteria for strength and hydraulic conductivity; to assess the leach performance of the solidified sediments; and to satisfy water quality parameters for turbidity, pH, and sheen. Approach/activities: The pilot study utilized a customized marine platform (modular floats, tug boats, etc.) and full‐scale ISS equipment (auger rig, silos, etc.) and varied operational parameters to provide a range of data to assist in evaluating the feasibility and efficacy of the technology for use in similar environments and in planning future ISS projects on the water. Water quality controls and monitoring were implemented during the operation, and the study documented and evaluated the environmental disruption (short‐term impacts) and costs of the application of the ISS process to contaminated aquatic sediments. ©2016 Wiley Periodicals, Inc.