Genetic polymorphisms: Impact on the risk of fetal alcohol spectrum disorders

Clinical reports on monozygotic and dizygotic twins provided the initial evidence for the involvement of genetic factors in risk vulnerability for fetal alcohol spectrum disorders (FASD) including fetal alcohol syndrome (FAS). Research with selectively bred and inbred rodents, genetic crosses of these lines and strains, and embryo culture studies have further clarified the role of both maternal and fetal genetics in the development of FASD. Research to identify specific polymorphisms contributing to FASD is still at an early stage. To date, polymorphisms of only one of the genes for the alcohol dehydrogenase enzyme family, the ADH1B, have been demonstrated to contribute to FASD vulnerability. In comparison with ADH1B*1, both maternal and fetal ADH1B*2 have been shown to reduce risk for FAS in a mixed ancestry South African population. ADH1B*3 appears to afford protection for FASD outcomes in African-American populations. Other candidate genes should be examined with respect to FASD risk, including those for the enzymes of serotonin metabolism, in particular the serotonin transporter. By its very nature, alcohol teratogenesis is the expression of the interaction of genes with environment. The study of genetic factors in FASD falls within the new field of ecogenetics. Understanding of the array of genetic factors in FASD will be enhanced by future genetic investigations, including case-control, family association, and linkage studies. Birth Defects Research (Part A), 2005

Macrostructural analysis : unravelling polyphase glacitectonic histories

Many Pleistocene glacial profiles look extremely simple, comprising till, or glacitectonite, overlying older sediments or bedrock (Figure 4.1). In more complex sequences the till may itself be overlain by younger sediments laid down as the ice retreated or during a completely separate, later phase of advance. Macroscopically, subglacial traction tills (Evans et al., 2007) are typically massive, unstructured deposits suggesting that it should be relatively straightforward to unravel the glacitectonic deformation history recorded by the sequence. Many reconstructions do indeed look very simple, slabs of sediment have been tilted and stacked and then overridden by the glacier to cap the structure with till. Added to this is the use of vertical exaggeration which makes the whole structure look like alpine tectonics (for an example see fig. 5 in van Gijssel, 1987). Dropping the exaggeration led to the recognition that actually we were looking at much more horizontal structures, i.e. overriding nappes and not imbricated slabs (van der Wateren, 1987). Traditionally (van der Meer, 1987) glaciotectonics was thought to relate to large structures like big push moraines and not to smaller structures like drag structures underneath tills (Figure 4.2), let alone to the tills themselves. With the notion that deforming bed tills are tectonically and not sedimentologically structured and could be regarded as tectomicts (Menzies et al., 2006), comes the realisation that glacitectonics happens across a wide range of scales, from the microscopic to tens of kilometres. Only by realising the full range of glaciotectonic scales can we hope to understand the processes

Features of turbulence during wildland fires in forested and grassland environments

Fire-induced turbulence and the feedback into the fire, following ambient changes, differ for forested (sub-canopy) and grassland environments. Here, we synthesize observations from multiple experimental surface fires: two sub-canopy backing fires, one sub-canopy heading fire, and a grassland heading fire. We identify and compare the most essential coherent structures and processes of each case from the turbulent momentum fluxes and turbulent kinetic energy (TKE) budget terms. In the sub-canopy burns, turbulent eddies are strongest near the canopy top: high streamwise turbulent flux accompanies low cross-stream turbulent flux and vice versa. In the grassland fire, both streamwise and cross-stream eddies strengthen simultaneously until a certain height, informing a vertical length scale for the fire-influence. Moreover, the forward sweep from streamwise eddies assists in the fire spread by pushing hot gases towards unburnt fuel. In the sub-canopy fires, shear production and buoyancy production are more substantial near the canopy top for more intense fires, while their magnitudes decrease with decreasing fire intensity. At mid-canopy-height scales, buoyancy production dominates shear production, becoming the key mechanism for vertical transport of TKE. In the grassland fire, shear production dominates buoyancy production near the surface and is insignificant beyond a certain height relative to the flame length, while buoyancy production increases with height, becoming substantial further away from the surface. Turbulent transport terms are also active in both environments. For intense sub-canopy fires, there is a loss in TKE due to its expulsion to the boundary layer aloft via the transport term, compensated by a reversal process: TKE influx via the transport term. In the grassland fire, the transport term mimics this behavior until a certain height. The insights into the relative significance of the respective turbulent fluxes and TKE budget terms in each environment can help simplify the complex system of equations governing fire physics

The equation of state of solid nickel aluminide

The pressure-volume-temperature equation of state of the intermetallic compound NiAl was calculated theoretically, and compared with experimental measurements. Electron ground states were calculated for NiAl in the CsCl structure, using density functional theory, and were used to predict the cold compression curve and the density of phonon states. The Rose form of compression curve was found to reproduce the ab initio calculations well in compression but exhibited significant deviations in expansion. A thermodynamically-complete equation of state was constructed for NiAl. Shock waves were induced in crystals of NiAl by the impact of laser-launched Cu flyers and by launching NiAl flyers into transparent windows of known properties. The TRIDENT laser was used to accelerate the flyers to speeds between 100 and 600m/s. Point and line-imaging laser Doppler velocimetry was used to measure the acceleration of the flyer and the surface velocity history of the target. The velocity histories were used to deduce the stress state, and hence states on the principal Hugoniot and the flow stress. Flyers and targets were recovered from most experiments. The effect of elasticity and plastic flow in the sample and window was assessed. The ambient isotherm reproduced static compression data very well, and the predicted Hugoniot was consistent with shock compression data

Effect of Vehicle on the Nasal Absorption of Epinephrine During Cardiopulmonary Resuscitation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90174/1/j.1875-9114.1996.tb03030.x.pd

Deuterium Toward Two Milky Way Disk Stars: Probing Extended Sight Lines with the Far Ultraviolet Spectroscopic Explorer

We have carried out an investigation of the abundance of deuterium along two extended sight lines through the interstellar medium (ISM) of the Galactic disk. The data include Far Ultraviolet Spectroscopic Explorer (FUSE) observations of HD 195965 (B1Ib) and HD 191877 (B0V), as well as Space Telescope Imaging Spectrograph (STIS) observations of HD 195965. The distances to HD 195965 and HD 191877, derived from spectroscopic parallax, are 794+/-200 pc and 2200+/-550 pc, respectively, making these the longest Galactic disk sight lines in which deuterium has been investigated with FUSE. The higher Lyman lines clearly show the presence of deuterium. We use a combination of curve of growth analyses and line profile fitting to determine the DI abundance toward each object. We also present column densities for OI and NI toward both stars, and HI measured from Ly-alpha absorption in the STIS spectrum of HD 195965. The D/H ratios along these sight lines are lower than the average value found with FUSE for the local interstellar medium (37 to 179 pc from the Sun). These observations lend support to earlier detections of variation in D/H over distances greater than a few hundred pc. The D/H and O/H values measured along these sight lines support the expectation that the ISM is not well mixed on distances of ~1000 pc.Comment: 32 pages, 18 figures. Abridged abstract. Accepted for publication in ApJ. Uses emulateapj5.st

Red-Cockaded Woodpecker Status and Management: West Gulf Coastal Plain and Interior Highlands

Red-cockaded woodpecker populations declined precipitously following European settlement and expansion and cutting of the original pine forests across the southeastern United States. By 1990 most residual populations lacked demographic viability, existed in degraded habitat, and were isolated from other populations. The primary causes of this situation were harvest of the original pine forests of the southeastern United States, conversion of forested lands to other uses, short-rotation silvicultural practices, and alteration of the fire regime in the regenerated forests. As social and legal mandates changed, management of red-cockaded woodpeckers became a higher priority. Intensive management for red-cockaded woodpeckers is currently practiced on most public and a few private lands that still support populations. Recent population trends and the current status of red-cockaded woodpeckers in Oklahoma, Arkansas, Texas, and Louisiana reflect historical factors and the efficacy of recent management