An association between fetal abdominal wall defects and elevated levels of human chorionic gonadotropin in mid-trimester

We analysed maternal serum human chorionic gonadotropin (hCG) in 16 pregnancies with fetal abdominal wall defects previously identified prenatally by elevated maternal serum alpha-fetoprotein (AFP) or at birth. The AFP levels had a mean of 6·38 MOM (range 0·34–15·65), as expected with these defects. The hCG levels had a mean of 1·82 MOM (range 0·23–4·11). The hCG levels in five pregnancies (31·25 per cent) were above 2·30 MOM. Elevated levels of hCG may be associated with fetal abdominal wall defects.     

Inorganic fly-ash spheres as pollution tracers

Although fly-ash particles are found in high concentrations in areas of high acid deposition little environmental work has been done on the inorganic ash sphere (IAS) component. Spatial and temporal trends of IAS in the UK show similar patterns to those of spheroidal carbonaceous particles (SCP), except that there appears to be a continuous background of IAS in the sediment record. The ratio IAS:SCP shows similar trends to both fuel-type changes as identified by SCP characterisation and historical fuel consumption records. Spatial comparisons between IAS:SCP in lake surface sediments, SCP characterisation results and known particle sources are also good. IAS concentrations in lake surface sediments and measured and modelled total, wet and dry sulphur are significantly correlated and show similar results to those of SCP studies.     

Pseudomosaicism for trisomy 13: Three case reports

Pseudomosaicism is of particular concern in prenatal diagnosis when it involves mosaicism for a cytogenetic abnormality associated with a clinical syndrome which is compatible with postnatal life, such as trisomies for chromosomes 13, 18, and 21. The lack of data regarding the outcome of pregnancies involving these specific kinds of pseudomosaicism makes genetic counselling difficult. Three cases of prenatal diagnosis of pseudomosaicism for trisomy 13, each of which had a normal outcome, will be presented (Tables 1 and 2). The three main areas for consideration are: (1) the genetic counselling issues, (2) the additional prenatal diagnostic options available to evaluate the status of the fetus in an attempt to identify some of the clinical features of trisomy 13, and (3) the outcome of the pregnancies.     

Detection of Cryptosporidium parvum oocysts in sediment and biosolids by immunomagnetic separation.

A method for the detection of Cryptosporidium parvum oocysts in sediment and wastewater biosolids has been developed using immunomagnetic separation kits that were designed for use with water. This method requires no pretreatment of the sediment or biosolids samples before the commercial kit application. Oocyst recovery efficiencies from sediment and biosolids using the modified Dynal (Lake Success, New York) and Crypto-Scan commercial methods (Immucell Corporation, Portland, Maine) ranged from 20 to 60%. While the sensitivity of the method is dependent on the amount of sediment processed and the equivalent volume examined under the microscope, it was able to detect 0.48 oocysts per gram dry weight sediment. Using this method, Cryptosporidium parvum oocysts were found at levels as high as 97 oocysts/g of primary biosolids and at levels up to 4 oocysts/g in polluted sediment.     

Driving performance comparing older versus younger drivers

Objectives: A cross-sectional study was conducted at the Touro University California campus to compare differences in reaction times and driving performance of younger adult drivers (18–40 years) and older adult drivers (60 years and older). Each test group consisted of 38 participants.

Methods: A Simple Visual Reaction Test (SVRT) tool was used to measure reaction times. The STISIM Drive M100 driving simulator was used to assess driving parameters. Driving performance parameters included mean lane position, standard deviation of mean lane position measured, mean speed, standard deviation of mean speed, car-following delay, car-following modulus, car-following coherence, off-road accidents, collisions, pedestrians hit, and traffic light tickets.

Results: Compared to younger participants, older drivers experienced significantly slower reaction times (510.0 ± 208.8 vs. 372.4 ± 96.1 ms, P =.0004), had more collisions (0.18 ± 0.39 vs. none, P =.0044), drove slower (44.6 ± 6.6 vs. 54.9 ± 11.7 mph, P <.0001), deviated less in speed (12.6 ± 4.3 vs. 16.8 ± 6.3, P =.0011), and were less able to maintain a constant distance behind a pace car (0.42 ± 0.23 vs. 0.59 ± 0.24; P =.0025).

Conclusions: Differences exist in driving patterns of older and younger drivers as measured by reaction times and driving simulator outcomes. These results are the first to compare these 2 specific adult age groups' driving performance as measured by a standardized driving simulator scenario. Identifying these differences is essential in addressing them and preventing future traffic injuries.     

Responses to extreme seasonality in food supply: diet plasticity in Antarctic brachiopods

The ice gouged, shallow, polar seabed is a challenging place to live, but suspension feeders are particularly rich and abundant there. The extreme seasonality of food supply from phytoplankton at high latitudes, combined with very stable temperatures has not, however, reduced the range of life history adaptations. Some species extend feeding and growing periods by concentrating on smaller, lower biomass but longer duration, fractions of phytoplankton. Here we show that shallow-water Antarctic brachiopods can switch from pelagic to benthic food sources when required. Like most suspension feeders they utilise the extremely abundant summer phytoplankton blooms, but unlike many other groups brachiopods do not appear to become dormant in winter. In shallow sites around the world wind and wave action resuspend benthic material, making it available to filter feeders. Widespread ice disturbance at polar latitudes may also cause resuspension enhancing local food supply. Articulate brachiopods have blind-ended guts and probably feed little once a large bolus of food has been collected, so a resuspension event may represent a significant enhancement of yearly food availability. The key to their ability to utilise unpredictable food sources is the same trait responsible for their polar success; very low maintenance costs and a catholic diet. Utilising resuspended material could be an important factor in global brachiopod distributions. Previously difficult to explain high brachiopod densities in New Zealand, Northwest Europe and the Canadian Pacific Coast may occur because these areas are all in the worlds windiest, and hence strongest resuspension, latitudes.Communicated by J.P. Thorpe, Port Erin     

Zum indirekten Photoabbau chlororganischer Verbindungen durch OH-Radikale in der Atmosphäre

The substituent chlorine is generally considered to be an agent which reduces the reactivity of organic molecules with regard to the indirect photodegradation by OH radicals. A systematic study of selected, representative classes of compounds, however, reveals that the deactivating influence of chlorine on the OH radical reactivity is actually rather moderate. In individual cases, for instance, chlorine substitution can even lead to an increase in this reactivity. This study is based on both experimental data and on the molecular orbital calculations of OH radical reactivity.     

Reproductive biology of three species of midwater fishes associated with the continental slope of eastern Tasmania,Australia

The reproductive biology of Lampanyctodes hectoris (Günther, 1876), Maurolicus muelleri (Gmelin, 1789) and Diaphus danae Tåning, 1932, from continental-slope waters of eastern Tasmania, was examined between April 1984 and June 1985. L. hectoris spawned in winter and M. muelleri spawned from late winter to early summer. Apart from one ripe male, no reproductive activity was detected in D. danae; this species may be an expatriate in these waters. Fecundity was positively correlated with standard length in L. hectoris, but not in M. muelleri. The ratio of females to males increased with length in all three species. The spermatozoa of L. hectoris and D. danae are atypical of vertebrates and have no tail.     

A greenhouse gas emissions inventory for Pennsylvania

The Pennsylvania greenhouse gas (GHG) emissions inventory presented in this paper provides detailed estimates of emissions and their sources for the six major categories of GHGs. The inventory was compiled using the current U.S. Environment Protection Agency methodology, which applies emissions factors to socioeconomic data, such as fossil energy use, vehicle miles traveled, and industrial production. The paper also contains an assessment of the methodology and suggestions for improving accounting with respect to process, sectoral, and geographic considerations. The study found that Pennsylvania emitted 77.4 million metric tons carbon equivalent of GHGs in 1990 and that this total increased by 3% to 79.8 million metric tons carbon equivalent by 1999. Despite this increase, however, the state's percentage contribution to the United States total declined during the decade. Pennsylvania's carbon dioxide (CO2) emissions from fossil fuels represented 92.4% of 1990 totals and declined to 90.5% in 1999. Electricity generation was the largest single source of CO2 emissions, being responsible for 38% of fossil fuel CO2 emissions in 1990 and 40% of the total in 1999. Transportation emissions accounted for the largest increases in emissions between 1990 and 1999, whereas industrial emissions accounted for the largest decrease. The overall trend indicates that Pennsylvania has been able to weaken the relationship between GHG emissions and economic growth.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.