Familial orofaciodigital syndrome type I revealed by ultrasound prenatal diagnosis of porencephaly

Porencephaly is a rare central nervous system (CNS) abnormality that can be caused by an intraparenchymal destructive process or a developmental defect. Here we report on a prenatal ultrasound diagnosis of complex CNS abnormalities including agenesis of the corpus callosum, agenesis of the cerebellar vermis, bilateral hydrocephaly, and bilateral porencephaly in fetus at 33 weeks' gestation. The diagnosis of familial orofaciodigital syndrome type I (OFD I) was raised after fetal autopsy, clinical examination of the family, and the X-linked dominant inheritance pattern. This is the fourth report of porencephaly in association with OFD I. We discuss the difficulties in genetic counselling since OFD I shows variable expressivity of the phenotypic features. Furthermore, we emphasize the importance of a detailed ultrasound examination after a prenatal diagnosis of porencephaly. Copyright © 2001 John Wiley & Sons, Ltd.     

Life in extreme environments: survival strategy of the endolithic desert lichen Verrucaria rubrocincta

Verrucaria rubrocincta Breuss is an endolithic lichen that inhabits caliche plates exposed on the surface of the Sonoran Desert. Caliche surface temperatures are regularly in excess of 60 degrees C during the summer and approach 0 degrees C in the winter. Incident light intensities are high, with photosynthetically active radiation levels typically to 2,600 micromol/m(2) s(-1) during the summer. A cross-section of rock inhabited by V. rubrocincta shows an anatomical zonation comprising an upper micrite layer, a photobiont layer containing clusters of algal cells, and a pseudomedulla embedded in the caliche. Hyphae of the pseudomedulla become less numerous with depth below the rock surface. Stable carbon and oxygen isotopic data for the caliche and micrite fall into two sloping, well-separated arrays on a delta(13)C-delta(18)O plot. The delta(13)C(PDB) of the micrite ranges from 2.1 to 8.1 and delta(18)O(SMOW) from 25.4 to 28.9, whereas delta(13)C(PDB) of the caliche ranges from -4.7 to 0.7 and delta(18)O(SMOW) from 23.7 to 29.2. The isotopic data of the micrite can be explained by preferential fixing of (12)C into the alga, leaving local (13)C enrichment and evaporative enrichment of (18)O in the water. The (14)C dates of the micrite range from recent to 884 years b.p., indicating that "dead" carbon from the caliche is not a significant source for the lichen-precipitated micrite. The endolithic growth is an adaptation to the environmental extremes of exposed rock surfaces in the hot desert. The micrite layer is highly reflective and reduces light intensity to the algae below and acts as an efficient sunscreen that blocks harmful UV radiation. The micrite also acts as a cap to the lichen and helps trap moisture. The lichen survives by the combined effects of biodeterioration and biomineralization. Biodeterioration of the caliche concomitant with biomineralization of a protective surface coating of micrite results in the distinctive anatomy of V. rubrocincta.     

Feeding behavior of the ctenophore <Emphasis Type="Italic">Thalassocalyce inconstans</Emphasis>: revision of anatomy of the order Thalassocalycida

Behavioral observations using a remotely operated vehicle (ROV) in the Gulf of California in March, 2003, provided insights into the vertical distribution, feeding and anatomy of the rare and delicate ctenophore Thalassocalyce inconstans. Additional archived ROV video records from the Monterey Bay Aquarium Research Institute of 288 sightings of T. inconstans and 2,437 individual observations of euphausiids in the Gulf of California and Monterey Canyon between 1989 and 2005 were examined to determine ctenophore and euphausiid prey depth distributions with respect to temperature and dissolved oxygen concentration [dO]. In the Gulf of California most ctenophores (96.9%) were above 350 m, the top of the oxygen minimum layer. In Monterey Canyon the ctenophores were more widely distributed throughout the water column, including the hypoxic zone, to depths as great as 3,500 m. Computer-aided behavioral analysis of two video records of the capture of euphausiids by T. inconstans showed that the ctenophore contracted its bell almost instantly (0.5 s), transforming its flattened, hemispherical resting shape into a closed bi-lobed globe in which seawater and prey were engulfed. Euphausiids entrapped within the globe displayed a previously undescribed escape response for krill (‘probing behavior’), in which they hovered and gently probed the inner surfaces of the globe with antennae without stimulating further contraction by the ctenophore. Such rapid bell contraction could be effected only by a peripheral sphincter muscle even though the presence of circumferential ring musculature was unknown for the Phylum Ctenophora. Thereafter, several live T. inconstans were collected by hand off Barbados and microscopic observations confirmed that assumption.     

Defecation by Salpa thompsoni and its contribution to vertical flux in the Southern Ocean

Measurements of the defecation rate of Salpa thompsoni were made at several stations during two cruises west of the Antarctic Peninsula in 2004 and 2006. Rates were quantified in terms of number of pellets, pigment, carbon and nitrogen for a wide size range of both aggregate and solitary salps. Measured defecation rates were constant over several hours when salps were held at near-surface conditions from which they had been collected. The defecation rate per salp increased with both salp size and the ambient level of particulate organic matter (POM) in the upper water column. The weight-specific defecation rate ranged between 0.5 and 6% day⁻¹ of salp body carbon, depending on the concentration of available particulate matter in the water. Carbon defecation rates were applied to biomass estimates of S. thompsoni to calculate daily carbon defecation rates for the populations sampled during the two cruises. Dense salp populations of over 400 mg C m⁻² were calculated to produce about 20 mg C m⁻² day⁻¹, comparable to other major sources of vertical flux of organic material in the Southern Ocean. Measured sinking rates for salp fecal pellets indicated that the majority of this organic material could reach deep sediments within a few days, providing a fast and direct pathway for carbon to the deep ocean.     

Turbulence characteristics within sparse and dense canopies

Boundary layer interactions with canopies control various environmental processes. In the case of dense and homogeneous canopies, the so-called mixing layer analogy is most generally used. When the canopy becomes sparser, a transition occurs between the mixing layer and the boundary layer perturbed by interactions between element wakes. This transition has still to be fully understood and characterized. The experimental work presented here deals with the effect of the canopy density on the flow turbulence and involves an artificial canopy placed in a fully developed turbulent boundary layer. One and two-component velocity measurements are performed, both within and above the canopy. The influence of the spacing between canopy elements is studied. Longitudinal velocity statistical moments and Reynolds stresses are calculated and compared to literature data. For spacings greater than the canopy height, evidences of this transition are found in the evolution of the skewness factor, shear length scale and mixing length.     

A Method for Improving the Management of Controversial Wetland

Valley bottom wetlands in agricultural landscapes often are neglected in national and regional wetland inventories. Although these areas are small, located in the bottomlands of the headwater catchments, and scattered in the rural landscape, they strongly influence hydrology, water quality, and biodiversity over the whole catchment area. Valley bottom wetlands often are considered as controversial wetlands. Awareness of the functional role of wetlands is increasing, in parallel with their progressive disappearance in intensive farming landscapes. The need to improve tools for controlling wetland management is a primary consideration for decision makers and land users. This article proposes a method for the inventory of valley bottom wetlands. The method is based on the functional analysis of potential, existing, and efficient valley bottom wetlands (the PEEW approach). Several indicators are proposed for checking the validity of such an approach. Potential wetlands are delineated by means of a topographic index using topographic and pedoclimatic criteria computed from a Digital Elevation Model and easily accessible databases. Existing wetlands are identified from observed surface moisture, the presence of specific wetland vegetation, or soil feature criteria. Efficient wetlands are defined through a given function, such as flow or pollutant regulation or biodiversity control. An analysis of areas at the limits between potential, existing, and efficient wetlands highlights land cultivated or drained in the past, which currently represents negotiating areas in which rehabilitation and other intended management actions can be implemented.     

Predictive statistical modelling of cadmium content in durum wheat grain based on soil parameters

Regulatory limits on cadmium (Cd) content in food products are tending to become stricter, especially in cereals, which are a major contributor to dietary intake of Cd by humans. This is of particular importance for durum wheat, which accumulates more Cd than bread wheat. The contamination of durum wheat grain by Cd depends not only on the genotype but also to a large extent on soil Cd availability. Assessing the phytoavailability of Cd for durum wheat is thus crucial, and appropriate methods are required. For this purpose, we propose a statistical model to predict Cd accumulation in durum wheat grain based on soil geochemical properties related to Cd availability in French agricultural soils with low Cd contents and neutral to alkaline pH (soils commonly used to grow durum wheat). The best model is based on the concentration of total Cd in the soil solution, the pH of a soil CaCl₂ extract, the cation exchange capacity (CEC), and the content of manganese oxides (Tamm’s extraction) in the soil. The model variables suggest a major influence of cadmium buffering power of the soil and of Cd speciation in solution. The model successfully explains 88% of Cd variability in grains with, generally, below 0.02 mg Cd kg^?1 prediction error in wheat grain. Monte Carlo cross-validation indicated that model accuracy will suffice for the European Community project to reduce the regulatory limit from 0.2 to 0.15 mg Cd kg^?1 grain, but not for the intermediate step at 0.175 mg Cd kg^?1. The model will help farmers assess the risk that the Cd content of their durum wheat grain will exceed regulatory limits, and help food safety authorities test different regulatory thresholds to find a trade-off between food safety and the negative impact a too strict regulation could have on farmers.

     

Managing tricky decentralised competencies: case study of a participatory modelling experiment on land use in the Lake Guiers area in Northern Senegal

We describe an action-research project whose objective was to help stakeholders at different organisational levels achieve sustainable land management by developing mediation models and tools. We chose to test a specific approach called companion modelling in the framework of a multidisciplinary research partnership and a formal local partnership (a ‘users committee’) involving an array of stakeholders at different organisational levels. The study area covers 10,000 km² of agro-pastoral land around Lake Guiers in northern Senegal. We conducted studies to update the knowledge base of the area and organised six field workshops that clearly revealed three important tool functions to support decision-making on land use at different scales, i.e. understanding maps, monitoring and evaluating land tenure, and foreseeing changes in land use. We found that a toolbox approach was the best way to implement the three functions and overcome the constraints faced by the research team and those linked to the timing of the project. Therefore, we produced five simple complementary tools aimed at various users: a farm-level optimisation model (for researchers and technical services), a database for land allocations and a discussion tool to assess the impact of land allocation decisions (for the rural council), a paper atlas (for local players) and a regional land use change simulation model (for regional and national planners). Participants were able to work with paper maps, to interpret computer-generated simulations of land use change and understand the strengths and limitations of each. Self-assessment of the research process emphasised the importance of the context and the critical role played by social capital at both the research and the field level, which, in turn, emphasised the need for major improvements in the design and implementation of a quality process for participatory modelling. It turns out that action-research may be an effective way to undertake sustainability science.     

Agricultural practices in grasslands detected by spatial remote sensing

The major decrease in grassland surfaces associated with changes in their management that has been observed in many regions of the earth during the last half century has major impacts on environmental and socio-economic systems. This study focuses on the identification of grassland management practices in an intensive agricultural watershed located in Brittany, France, by analyzing the intra-annual dynamics of the surface condition of vegetation using remotely sensed and field data. We studied the relationship between one vegetation index (NDVI) and two biophysical variables (LAI and fCOVER) derived from a series of three SPOT images on one hand and measurements collected during field campaigns achieved on 120 grasslands on the other. The results show that the LAI appears as the best predictor for monitoring grassland mowing and grazing. Indeed, because of its ability to characterize vegetation status, LAI estimated from remote sensing data is a relevant variable to identify these practices. LAI values derived from the SPOT images were then classified based on the K-Nearest Neighbor (KNN) supervised algorithm. The results points out that the distribution of grassland management practices such as grazing and mowing can be mapped very accurately (Kappa index?=?0.82) at a field scale over large agricultural areas using a series of satellite images.     

Spatial mapping of city-wide PBDE levels using an exponential decay model

Passive air samplers (PAS) consisting of polyurethane foam (PUF) disks were deployed at 6 outdoor air monitoring stations in different land use categories (commercial, industrial, residential and semi-rural) to assess the spatial distribution of polybrominated diphenyl ethers (PBDEs) in the Brisbane airshed. Air monitoring sites covered an area of ~1143 km(2) and PAS were allowed to accumulate PBDEs in the city's airshed over three consecutive seasons commencing in the winter of 2008. The average sum of five (∑(5)) PBDEs (BDEs 28, 47, 99, 100 and 209) levels were highest at the commercial and industrial sites (12.7 ± 5.2 ng PUF(-1)), which were relatively close to the city center and were a factor of 8 times higher than residential and semi-rural sites located in outer Brisbane. To estimate the magnitude of the urban 'plume' an empirical exponential decay model was used to fit PAS data vs. distance from the CBD, with the best correlation observed when the particulate bound BDE-209 was not included (∑(5)-209) (r(2) = 0.99), rather than ∑(5) (r(2) = 0.84). At 95% confidence intervals the model predicts that regardless of site characterization, ∑(5)-209 concentrations in a PAS sample taken between 4-10 km from the city centre would be half that from a sample taken from the city centre and reach a baseline or plateau (0.6 to 1.3 ng PUF(-1)), approximately 30 km from the CBD. The observed exponential decay in ∑(5)-209 levels over distance corresponded with Brisbane's decreasing population density (persons/km(2)) from the city center. The residual error associated with the model increased significantly when including BDE-209 levels, primarily due to the highest level (11.4 ± 1.8 ng PUF(-1)) being consistently detected at the industrial site, indicating a potential primary source at this site. Active air samples collected alongside the PAS at the industrial air monitoring site (B) indicated BDE-209 dominated congener composition and was entirely associated with the particulate phase. This study demonstrates that PAS are effective tools for monitoring citywide regional differences however, interpretation of spatial trends for POPs which are predominantly associated with the particulate phase such as BDE-209, may be restricted to identifying 'hotspots' rather than broad spatial trends.