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Eighteen lightning flash rate parameterization schemes (FRPSs) were investigated in a Weather Research and Forecasting model coupled with chemistry cloud‐resolved simulation of the 29–30 May 2012 supercell storm system observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. Most of the observed storm's meteorological conditions were well represented when the model simulation included both convective damping and lightning data assimilation techniques. Newly‐developed FRPSs based on DC3 radar observations and Lightning Mapping Array data are implemented in the model, along with previously developed schemes from the literature. The schemes are based on relationships between lightning and various kinematic, structural, and microphysical thunderstorm characteristics (e.g., cloud top height, hydrometeors, reflectivity, and vertical velocity) available in the model. The results suggest the model‐simulated graupel and snow/ice hydrometeors require scaling factors to more closely represent proxy observations. The model‐simulated lightning flash trends and total flashes generated by each scheme over the simulation period are compared with observations from the central Oklahoma Lightning Mapping Array. For this supercell system, 13 of the 18 schemes overpredicted flashes by >100% with the group of FRPSs based on storm kinematics and structure (particularly updraft volume) performing slightly better than the hydrometeor‐based schemes. During the storm's first 4 hr, the upward cloud ice flux FRPS, which is based on the combination of vertical velocity and hydrometeors, well represents the observed total flashes and flash rate trend; while, the updraft volume scheme well represents the observed flash rate peak and subsequent sharp decline in flash rate. Plain Language Summary: Accurate lightning forecasts are important for daily activities. They are also important because lightning produces nitrogen oxide, which affects the distribution of atmospheric trace gases that have significant roles in influencing our climate (e.g., ozone). Lightning is recreated in weather models using already determined relationships between observed lightning and thunderstorm characteristics (e.g., hydrometeors and vertical velocity). Lightning prediction is also highly dependent on how well the model represents current conditions, like thunderstorm location and strength. Eighteen lightning‐thunderstorm relationships, or schemes, were investigated in a cloud‐resolved Weather Research and Forecasting model coupled with chemistry to simulate the 29–30 May 2012 supercell storm system observed during the Deep Convective Clouds and Chemistry (DC3) field campaign and to identify the best scheme associated with the event. Modifications to the model‐simulation were first required to better represent the observed convection before comparing the observed and model‐simulated lightning. Generally, the schemes based on storm kinematics and structure perform slightly better for this case study than the microphysical schemes. Two schemes (i.e., upward cloud ice flux and updraft volume) well represent the supercell system's lightning activity. The upward cloud ice flux scheme was used in follow‐on lightning chemistry and trace gas analyses. Key Points: Thirteen of eighteen flash rate parameterization schemes overestimated the observed number of flashes by more than 100%Upward cloud ice flux and updraft volume schemes well represent lightning activity in the early and later stages of the storm, respectivelyFlash rate prediction is highly dependent on how schemes are applied in cloud‐resolved models and on accurate simulation of storm variables [ABSTRACT FROM AUTHOR]

Thin‐film photovoltaic device efficiencies are limited by carrier recombination, thus understanding recombination mechanisms is critical for performance improvements. Bulk minority carrier lifetime (τbulk) is a critical parameter for solar cells but is difficult to determine in P–N junction devices, especially for high doping. As doping ≥1016 cm−3 is required for efficient drift‐charge‐carrier‐collection devices, a method for τbulk determination in doped P–N junction devices is necessary. This work utilizes time‐resolved photoluminescence (TRPL) simulations to quantify bulk and interface recombination properties in highly doped, graded absorber CdSeTe structures. The two methods developed here for τbulk determination include utilization of an instantaneous lifetime representation to guide TRPL fitting and direct comparison between measured and simulated decays. Simulations verified that both methods are valid for state‐of‐the‐art device architectures which include graded bandgap absorbers, graded doping, and graded lifetimes. Shifts in the dominant recombination mechanism are identified for sufficiently long τbulk, where front and back interface quality plays a more prominent role. Evaluation of surface recombination velocities and conduction band offset illustrate electro‐optical advantages of a positive conduction band offset and highlight the necessity of improved interfaces as bulk quality in photovoltaic devices improves. [ABSTRACT FROM AUTHOR]

Louisiana contains nearly 40% of estuarine herbaceous wetlands in the contiguous United States, supporting valuable ecosystem services and providing significant economic benefits to the state and the entire United States. However, coastal Louisiana is a hotspot for rapid land loss from factors including hurricanes, land use change, and high subsidence rates contributing to high relative sea‐level rise. The Coastal Protection and Restoration Authority (CPRA) was established after major hurricanes in 2005 to coordinate coastal restoration in Louisiana and develop the Louisiana Coastal Master Plan. The LA Coastal Master Plan uses numerical modeling of multiple scenarios to select a suite of restoration projects based on maximum land area created and flood reduction (as proxies for ecosystem value). Using potential value to aquatic, terrestrial, and social resources, our work compared habitat value of shallow open water areas to emergent wetland. While potential resource benefits varied by emergent wetland salinity type and emergent wetland versus water, they were similar, suggesting that restoration planning based primarily on wetland land area may not achieve the maximum possible ecosystem benefits. After nearly 20 years of integrated restoration planning in coastal Louisiana, a reassessment of restoration planning decision drivers may be beneficial to ensure maximum benefits from coastal restoration. As a result of the Deepwater Horizon oil spill, settlement funds will be a major support to coastal restoration in Louisiana for many years. Assessing potential habitat value to multiple natural and social resources in Louisiana has potential to maximize synergy with large northern Gulf of Mexico restoration programs. [ABSTRACT FROM AUTHOR]

Coastal marshes are essential habitats for soil carbon accumulation and burial, which can influence the global carbon budget. Coastal Louisiana has extensive marsh habitats (fresh, intermediate, brackish, and saline) where soil cores were collected to a depth of 100 cm at 24 sites to assess long‐term carbon accumulation and burial rates. Select soil depth intervals were analyzed for bulk density, total carbon, and radionuclide (137Cs and 210Pb) dating. Marsh habitat maps (years 1949–2013) were also used to determine the most frequently occurring habitat at each field site. Over 5 decades, half of the sites transitioned between marsh habitats at least once. Saline marshes tended to have lower mean total carbon density (0.04 ± 0.002 g cm−3) and lower mean long‐term total carbon accumulation rates (211 ± 46 g TC m−2 yr−1, n = 5, based on 210Pb) compared to the other marsh habitats. Using marsh habitat specific accumulation rates and area, the total carbon burial rate for coastal Louisiana in year 2013 was estimated at 4.3 Tg TC yr−1 which accounts for about 5%–21% of the estimated tidal wetland burial rate globally. Historically, about 1.0 Tg TC yr−1 was lost due to reduced marsh area from 1949 to 2013. With no coastal restoration activity, the predicted wetland loss over the next 50 years could reduce carbon burial in coastal Louisiana to 2.1 Tg TC yr−1, a reduction of about 50% from the year 2013 rate, with potential to significantly alter the global carbon budget. Key Points: Marsh habitat soils in coastal Louisiana accumulate on average 211–381 g TC m−2 year−1 over the long term (decades)Louisiana marsh soils bury 4.3 Tg TC year−1, accounting for 5%–21% of global, 47% of North America, and 65% of Gulf of Mexico ratesHalf of the current soil carbon sink in coastal Louisiana marshes could be lost in the next 50 years with no coastal restoration activity [ABSTRACT FROM AUTHOR]

Human activities have released large quantities of neutral persistent organic pollutants (POPs) that may be biomagnified in food webs and pose health risks to wildlife, particularly top predators. Here we develop a global 3‐D ocean simulation for four polychlorinated biphenyls (PCBs) spanning a range of molecular weights and volatilities to better understand effects of climate‐driven changes in ocean biogeochemistry on the lifetime and distribution of POPs. Observations are most abundant in the Arctic Ocean. There, model results reproduce spatial patterns and magnitudes of measured PCB concentrations. Sorption of PCBs to suspended particles and subsequent burial in benthic marine sediment is the dominant oceanic loss process globally. Results suggest benthic sediment burial has removed 75% of cumulative PCB releases since the onset of production in 1930. Wind speed, light penetration, and ocean circulation exert a stronger and more variable influence on volatile PCB congeners with lower particle affinity such as chlorinated biphenyl‐28 and chlorinated biphenyl‐101. In the Arctic Ocean between 1992 and 2015, modeled evasion (losses) of the more volatile PCB congeners from the surface ocean increased due to declines in sea ice and changes in ocean circulation. By contrast, net deposition increased slightly for higher molecular weight congeners with stronger partitioning to particles. Our results suggest future climate changes will have the greatest impacts on the chemical lifetimes and distributions of volatile POPs with lower molecular weights. Key Points: Climate change will have the greatest impacts on the chemical lifetimes and distributions of volatile persistent organic pollutantsMarine sediment has sequestered 75% of cumulative releases of polychlorinated biphenyls since the onset of production in 1930Arctic sea ice retreat is likely to enhance losses of volatile congeners but increase net deposition of higher molecular weight congeners [ABSTRACT FROM AUTHOR]

Abstract: Coastal wetlands store more carbon than most ecosystems globally. As sea level rises, changes in flooding and salinity will potentially impact ecological functions, such as organic matter decomposition, that influence carbon storage. However, little is known about the mechanisms that control organic matter loss in coastal wetlands at the landscape scale. As sea level rises, how will the shift from fresh to salt‐tolerant plant communities impact organic matter decomposition? Do long‐term, plant‐mediated, effects of sea‐level rise differ from direct effects of elevated salinity and flooding? We identified internal and external factors that regulated indirect and direct pathways of sea‐level rise impacts, respectively, along a landscape‐scale salinity gradient that incorporated changes in wetland type (fresh, oligohaline, mesohaline and polyhaline marshes). We found that indirect and direct impacts of sea‐level rise had opposing effects on organic matter decomposition. Salinity had an indirect effect on litter decomposition that was mediated through litter quality. Despite significant variation in environmental conditions along the landscape gradient, the best predictors of above‐ and below‐ground litter decomposition were internal drivers, initial litter nitrogen content and initial litter lignin content respectively. Litter decay constants were greatest in the oligohaline marsh and declined with increasing salinity, and the fraction of litter remaining (asymptote) was greatest in the mesohaline marsh. In contrast, direct effects of salinity and flooding were positive. External drivers, salinity and flooding, stimulated cellulytic activity, which was highest in the polyhaline marsh. Synthesis. Our results indicate that as sea level rises, initial direct effects of salinity will stimulate decay of labile carbon, but over time as plant communities shift from fresh to polyhaline marsh, litter decay will decline, yielding greater potential for long‐term carbon storage. These findings highlight the importance of quantifying carbon loss at multiple temporal scales, not only in coastal wetlands but also in other ecosystems where plant‐mediated responses to climate change will have significant impacts on carbon cycling. [ABSTRACT FROM AUTHOR]

Background Somatosensory modalities, such as touch, proprioception and haptic ability, greatly influence the achievement of developmental milestones for children. Describing somatosensory impairment, natural variability and typical or expected developmental changes across age groups will help establish frameworks for intervention in clinical populations. This systematic review aimed to determine how different somatosensory modalities develop across childhood into adolescence to use as a point of reference for children at risk of somatosensory impairment. Methods Searches of five electronic databases were undertaken through EBSCO-host (MEDLINE, CINAHL, PsycINFO, SPORTDiscus and ERIC) for studies measuring at least one somatosensory modality in typically developing individuals between birth and 18 years and analysed by age. Characteristics of studies were collected including country of origin, sample size, demographics and outcome measure used. Quality assessment and data extraction were performed by two independent reviewers. Results Twenty three cross-sectional studies were included from a total of 188 articles retrieved: 8 examined aspects of touch, 5 proprioception and 10 haptic ability. Variability of study designs and variation in assessment tools precluded any formal meta-analysis. Conclusions Somatosensation matures through childhood into adolescence; however, the present review found the pattern of somatosensory development varied depending on the assessment tool used and the aspect of somatosensation being measured, making it difficult to describe typical performance. There is a need for comprehensive assessment batteries to measure the somatosensation, including touch, proprioception and haptic ability, of children at risk of somatosensory impairment to aid in the development of effective interventions. [ABSTRACT FROM AUTHOR]

Multimedia models based on chemical fugacity, solved numerically, play an important role in investigating and quantifying the environmental fate of chemicals such as persistent organic pollutants. These models have been used extensively in studying the local and global distribution of chemicals in the environment. The present study describes potential sources of error that may arise from the formulation and numerical solution of environmental fugacity models. The authors derive a general fugacity equation for the rate of change of mass in an arbitrary volume (e.g., an environmental phase). Deriving this general equation makes clear several assumptions that are often not articulated but can be important for successfully applying multimedia fugacity models. It shows that the homogeneity of fugacity and fugacity capacity in a volume (the homogeneity assumption) is fundamental to formulating discretized fugacity models. It also shows that when using the fugacity rather than mass as the state-variable, correction terms may be necessary to accommodate environmental factors such as varying phase temperatures and volume. Neglecting these can lead to conservation errors. The authors illustrate the manifestation of these errors using heuristic multimedia fugacity models. The authors also show that there are easily avoided errors that can arise in mass state-variable models if variables are not updated appropriately in the numerical integration scheme. Environ Toxicol Chem 2016;35:2182-2191. © 2016 SETAC [ABSTRACT FROM AUTHOR]

Objectives First, to assess the performance of a prenatal diagnostic service using quantitative fluorescent polymerase chain reaction (QF-PCR) and array comparative genomic hybridization (aCGH) as first-line investigations. Second, to determine the incidence of copy number variants (CNVs) by indication for testing, with particular reference to ultrasound and biochemical parameters measured in combined first-trimester screening. Methods All patients undergoing invasive prenatal testing at a specialist prenatal screening service in Sydney, Australia, were included in the study. All samples underwent QF-PCR and targeted aCGH. Results Of 1049 cases, CNVs were reported in 156 (14.9%). Preliminary QF-PCR identified abnormalities in 104 of these cases. Of the remaining 52 cases, 20 could have been detected on karyotype testing, leaving 32 cases (3.1%) with CNVs only detectable by aCGH, of which 13 (1.2%) were pathogenic. Variants of unknown significance (VOUS) were seen in only three cases. Fetal structural abnormalities identified in the first trimester were the group most likely to be associated with pathogenic CNVs (11.8%). Conclusions Combining QF-PCR and aCGH is an effective first-tier prenatal testing regime that does not require conventional karyotyping. The incidence of VOUS in this study was very low owing to appropriate aCGH targeting and specific reporting criteria that reduced the number of potentially difficult counseling encounters. Pathogenic CNVs are positively correlated with the presence of fetal structural abnormalities, but not with enlarged nuchal translucency or abnormal first-trimester serology results. [ABSTRACT FROM AUTHOR]

Freely dissolved and gas phase polychlorinated dibenzo- p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in the water column and atmosphere at five locations within Newark Bay (New Jersey, USA) from May 2008 to August 2009 with polyethylene (PE) passive samplers. Mono- to octa-CDDs and mono- to hepta-CDFs were detected in bottom and surface waters at ≤20 pg/L with no clear gradient between sampling locations, suggesting freely dissolved PCDD/Fs are well mixed in Newark Bay. The most concentrated, freely dissolved gas phase congener was 2,7/2,8-dichlorodibenzo- p-dioxin (2,7/2,8-DiCDD), likely originating from photochemical conversion of triclosan in Newark Bay. Air-surface water gradients strongly favored net volatilization of PCDD/PCDFs from Newark Bay. Water-to-air fluxes of 2,7/2,8-DiCDD and 2,3,7,8-tetrachlorodibenzo- p-dioxin (2,3,7,8-TCDD), the most concentrated and the most toxic PCDD/PCDFs, respectively, were approximately 60 ng/m2 per month and 14 to 51 pg/m2 per month. Significant decreases in freely dissolved 2,3,7,8-TCDD concentrations with increasing freshwater near the Passaic River and conservative behavior during the summer of 2009 suggested Passaic sediments as a likely source of 2,3,7,8-TCDD to Newark Bay. Mass balance calculations implied that almost 50% of freely dissolved 2,3,7,8-TCDD delivered to Newark Bay from the Hackensack and Passaic Rivers was lost to volatilization in the summer of 2009. Environ. Toxicol. Chem. 2012;31:253-261. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Molecular biologists commonly use bioinformatics to map and analyze DNA and protein sequences and to align different DNA and protein sequences for comparison. Additionally, biologists can create and view 3D models of protein structures to further understand intramolecular interactions. The primary goal of this 10-week laboratory was to introduce the importance of bioinformatics in molecular biology. Students employed multiprimer, site-directed mutagenesis to create variant colors from a plasmid expressing green fluorescent protein (GFP). Isolated mutant plasmid from Escherichia coli showing changes in fluorescence were sequenced. Students used sequence alignment tools, protein translator tools, protein modeling, and visualization to analyze the potential effect of their mutations within the protein structure. This laboratory linked molecular techniques and bioinformatics to promote and expand the understanding of experimental results in an upper-level undergraduate laboratory course. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 39, No. 6, pp. 448-456, 2011 [ABSTRACT FROM AUTHOR]

Sediments from the New Bedford Harbor (NBH) U.S. Environmental Protection Agency (U.S. EPA) Superfund site (Massachusetts, USA), contaminated with polychlorinated biphenyls (PCBs), were resuspended under different water column redox conditions: untreated, oxidative, and reductive. The partitioning of PCBs to the overlying water column was measured with polyethylene samplers and compared to partitioning without resuspension. Greater concentrations of total aqueous (freely dissolved + dissolved organic carbon (DOC)-associated) PCBs were found in all resuspended treatments for PCBs with mid-range Ks, but no difference was observed in total aqueous concentrations among different redox conditions. The magnitude of increased concentrations depended on resuspension time and congener K, but ranged from approximately one to eight times those found without resuspension. In a parallel study, DOC was flocculated and removed from smaller-scale NBH sediment resuspensions. In situ Ks were determined and used to calculate freely dissolved and DOC-associated fractions of the increase in total aqueous PCB concentrations due to resuspension. The importance of DOC-associated PCBs increased with increasing K. In situ Ks were approximately one to two orders of magnitude greater than those calculated with a commonly used linear free energy relationship (LFER). The present study demonstrates that resuspension of contaminated sediments releases PCBs to the water column, of which a significant fraction are DOC-associated (e.g., 28, 65, and 90% for PCBs 28, 66, and 110, respectively). Results also imply that site-specific PCB Ks are superior to those calculated with generic LFERs. Environ. Toxicol. Chem. 2011;30:377-384. © 2010 SETAC [ABSTRACT FROM AUTHOR]

Marine and estuarine sediments accumulate contaminants and act as a sink for a wide range of toxic chemicals. As a result, the sediments themselves can become a source of contamination. At sufficient levels, contaminated sediments can cause benthic impairments and toxicity to marine organisms. Among the wide range of contaminants, nonionic organic contaminants (NOCs) are a primary cause of toxicity in marine sediments. Toxicity identification evaluations (TIEs) are used to characterize and identify chemicals causing toxicity in effluents, interstitial waters, and whole sediments using whole-organism endpoints. Phase I whole-sediment TIE methods for NOCs exist, but the development of phase II TIE methods for NOCs is a current research challenge. In the present study, the use of reverse polyethylene samplers (RePES) for phase II methods is examined. Various RePES designs were evaluated in an experimental design study with NOC chemical solutions. Based on equilibration time and proximity of measured NOC water concentrations in the reconstituted system to theoretical concentrations, a nontriolein design with loading of chemical solutions on the inside of the polyethylene tubing was chosen as most effective. A partitioning study demonstrated NOCs partitioned between the RePES and water as well as between the water and air, as expected using this nontriolein RePES design. Finally, a sediment toxicity study comparing the nontriolein RePES to contaminant-spiked sediments was conducted. The nontriolein RePES design was capable of successfully recreating the toxicity and water concentrations observed with the intact sediments. [ABSTRACT FROM AUTHOR]

Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments. [ABSTRACT FROM AUTHOR]

Anther development in flowering plants involves the formation of several cell types, including the tapetal and pollen mother cells. The use of genetic and molecular tools has led to the identification and characterization of genes that are critical for normal cell division and differentiation in Arabidopsis early anther development. We review here several recent studies on these genes, including the demonstration that the putative receptor protein kinases BAM1 and BAM2 together play essential roles in the control of early cell division and differentiation. In addition, we discuss the hypothesis that BAM1/2 may form a positive-negative feedback regulatory loop with a previously identified key regulator, SPOROCYTELESS (also called NOZZLE), to control the balance between sporogenous and somatic cell types in the anther. Furthermore, we summarize the isolation and functional analysis of the DYSFUNCTIONAL TAPETUM1 (DYT1) gene in promoting proper tapetal cell differentiation. Our finding that DYT1 encodes a putative transcription factor of the bHLH family, as well as relevant expression analyses, strongly supports a model that DYT1 serves as a critical link between upstream factors and downstream target genes that are critical for normal tapetum development and function. These studies, together with other recently published works, indicate that cell-cell communication and transcriptional control are key processes essential for cell fate specification in anther development. [ABSTRACT FROM AUTHOR]

OBJECTIVES: There is a growing literature that suggests cognitive behavioural interventions aimed at reducing inappropriately expressed anger by people with intellectual disabilities are effective. However, interventions provide little information about which aspects of the individual or their treatment may be contributing to the overall efficacy of the approach. DESIGN: A group intervention is compared with a waiting list control. A cross-sectional regressional method was used to explore the relationship between change in a provocation inventory score over the course of an intervention and a number of other variables. METHODS: Data was collected from 50 participants who attended a series of groups with the aim of reducing aggressive behaviour. This was compared with a waiting list control of 36. Outcome was measured by a provocation inventory, which was administered pre-, post-group, and at follow-up. Other variables were also measured including, receptive vocabulary, age, gender, experience of primary therapist and whether staff accompanied participants to the group or not. RESULTS: A 2 x 2 split plot ANOVA identified a statistically significant treatment effect. However, analysis examining clinical significance was more equivocal with only 11 of the individuals in the intervention group showing reliable change as defined by Jacobson and Truax (1991). Regression analysis indicated that 17.5% of the variance in change of provocation inventory scores could be accounted for by the independent variables. Immediately on completion of the group, being accompanied by a member of staff and increased receptive language scores contributed significantly to the variance. CONCLUSIONS: A reduction in provocation inventory scores immediately after the group was more likely to occur if the participant was accompanied by a member of staff who knew them and if they had a higher score on the test of receptive vocabulary. This pattern changed with time. The implications of the results will be discussed and the relatively large amount of variance that is not accounted for will also be considered. [ABSTRACT FROM AUTHOR]

League tables are weighted combinations of scores on performance indicators. The Times newspaper publishes an annual league table of British universities and the focus of this article is the 1994 table. The scores of ninety-six universities on fourteen performance indicators are ranked using weights which 'reflect the interests of students'. The league table is intended as a resource which allows students to compare universities and therefore it is important for both students and universities that valid inferences can be drawn from its use. The table fails to meet any of the technical requirements which would assure its internal construct validity. The educational measurement literature requires that validity inquiry must include consideration of social consequences and it is demonstrated that the technical shortcomings of the Times table could have significant adverse impact, even in the top ten universities. It is argued that universities should forsake their current stance of non-co-operation and develop a shortlist of demanding technical standards, linked to the educational measurement literature, which could be referenced in effective attacks upon poorly constructed league tables. [ABSTRACT FROM AUTHOR]

An abstract of the research paper "Prenatal diagnosis using combined qf- PCR and array CGH analysis as a first line test: results from over 1000 consecutive cases," by F. P. Scott and colleagues is presented.

Background: Ethanol causes significant teratogenicity in normal (MT+/+) but not metallothionein-null (MT-/-) fetuses. Impaired maternal fetal zinc (Zn) transfer is indicated, because ethanol significantly reduces plasma Zn concentrations in MT+/+ dams while increasing concentrations in MT-/- dams. In this study we examined maternal-fetal Zn homeostasis in response to ethanol in MT+/+ and MT-/- mice and the origins of the increase in plasma Zn in MT-/- mice., Methods and Results: Mice were treated with saline or ethanol (0.015 ml/g intraperitoneally at 0 and 4 hr) on day 12 of gestation. An additional subcutaneous injection of 65Zn tracer was administered after the second ethanol injection before mice were killed 3 hr later. Maternal liver MT levels were not different between ethanol and saline MT+/+ mice. Both liver Zn and 65Zn levels were higher in MT+/+ mice. Plasma Zn concentrations were higher in MT-/- mice, with MT-/- ethanol-treated mice having levels greater than those of MT-/- saline-treated controls. MT+/+ ethanol-treated fetuses exhibited lower 65Zn transfer and whole Zn concentrations compared with MT+/+ and MT-/- saline and MT-/- ethanol fetuses. So we could examine changes in plasma Zn after ethanol treatment, MT+/+ and MT-/- mice were injected with 65Zn 3 days before they received ethanol treatment. Muscle and skin showed a decrease in 65Zn retention in both genotypes over 3 hr. There was a trend toward greater 65Zn release from skin and muscle at an earlier time in MT-/- mice: 24% vs. 2% decrease (MT-/- vs. MT+/+) for muscle and 28% vs. 15% decrease (MT-/- vs. MT+/+) for skin at 2 hr., Conclusions: The results show (a) that ethanol interferes with the transfer of Zn to the fetus, and that this is MT dependent, and (b) that the increase in plasma Zn seen in MT-/- mice after ethanol administration is a result of Zn release from the skin and muscle, in the absence of hepatic Zn sequestration.

Background: Ethanol profoundly affects fetal development, and this is proposed to be due primarily to a transient fetal zinc (Zn) deficiency that arises from the binding of Zn by metallothionein (MT) in the maternal liver. Zn homeostasis and fetal outcome were investigated in normal (MT+/+) and metallothionein-null (MT-/-) mice in response to ethanol exposure., Methods/results: Mice were treated with saline or ethanol (0.015 m/g intraperitoneally at 0 and 4 hr) on day 8 of gestation (Gd8), and the degree of fetal dysmorphology was assessed on Gd18. The incidence of external abnormalities was significantly increased in offspring from MT+/+ dams exposed to ethanol, where 27.4% of fetuses were affected. MT-/- ethanol-, MT+/+ saline-, and MT-/- saline-treated dams had fetuses in which the frequencies of abnormalities were 2.2, 6.4, and 6.9%, respectively. To investigate Zn homeostasis, nonpregnant mice were killed at intervals over 16 hr after ethanol injection. Liver MT concentrations in MT+/+ mice were increased 20-fold by 16 hr, with a significant elevation evident by 4 hr, whereas liver Zn levels were also significantly increased by 2 hr and maintained for 16 hr. In parallel with these changes, plasma Zn concentrations in MT+/+ mice decreased by 65%, with minimum levels of 4.5+/-0.3 micromol/liter at 8 hr. Conversely, MT-/- mice exhibited increased plasma Zn concentrations, with peak values of 20.8+/-0.3 observed at 4 hr., Conclusion: These findings link the teratogenic effect of ethanol to the induction of maternal MT and the limitation of fetal Zn supply from the plasma.