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.     

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     

An Experiment in Making Water Affordable: Philadelphia’s Tiered Assistance Program (TAP)

The ability to pay for water and wastewater services is a growing issue in the developed world. To this point in time, utilities have helped customers grappling with affordability issues using different types of customer assistance programs (CAPs). Income‐based billing approaches differ from CAPs in that bills are structured so as to be affordable for customers at the outset. Recently, the City of Philadelphia implemented an innovative program to work towards resolving the affordability problem in their city using income‐based billing. This tiered assistance program or TAP structures bills for water, wastewater, and stormwater services to program enrollees’ income. Given the innovative nature of the program, this paper describes the rollout of TAP and assesses the impact of the program on customers and utility revenues. The paper closes with a critical assessment of TAP and considerations for utilities evaluating the implementation of similar programs.     

A spatiotemporal Richards–Schnute growth model and its estimation when data are collected through length-stratified sampling

Environmental and Ecological Statistics - We propose a spatiotemporal generalized von Bertalanffy (vonB) growth model that also includes between-individual (BI) variation and male/female...     

The Need for Flexibility in Conservation Practices: Exotic Species as an Example

To garner support for biodiversity from the World’s human population, conservation biologists need an open-minded, integrated conservation strategy. We suggest that this strategy should include efforts to (1) preserve existing high quality, diverse ecosystems, (2) remediate impaired systems, (3) balance the needs of people and ecological resources, and (4) engender appreciation of nature and its services. We refer to these four key tenets as reservation, restoration, reconciliation, and reconnection. We illustrate these concepts by presenting the debate surrounding the management of exotic species from an unusual perspective, the benefits of exotic species. By this example we hope to encourage an integrated approach to conservation in which management strategies can be flexible, adjusting to society’s needs and the overall goals of conservation.     

Evaluation of lot-to-lot repeatability and effect of assay media choice in the recombinant Factor C assay

Measurement of environmental endotoxin exposures is complicated by variability encountered using current biological assay methods arising in part from lot-to-lot variability of the Limulus-amebocyte lysate (LAL) reagents. Therefore, we investigated the lot-to-lot repeatability of commercially available recombinant Factor C (rFC) kits as an alternative to LAL. Specifically, we compared endotoxin estimates obtained from rFC assay of twenty indoor dust samples, using four different extraction and assay media, to endotoxin estimates previously obtained by Limulus amebocyte lysate (LAL) assay and amounts of 3-hydroxy fatty acids (3-OHFA) in lipopolysaccharide (LPS) using gas-chromatography mass spectroscopy (GC-MS). We found that lot-to-lot variability of the rFC assay kits does not significantly alter endotoxin estimates in house dust samples when performed using three of the four assay media tested and that choice of assay media significantly altered endotoxin estimates obtained by rFC assay of house dust samples. Our findings demonstrate lot-to-lot reproducibility of rFC assay of environmental samples and suggest that use of rFC assay performed with Tris buffer or water as the extraction and assay medium for measurement of endotoxin in dust samples may be a suitable choice for developing a standardized methodology.