A large terrestrial source of methyl iodide

We have identified terrestrial sources of methyl iodide (CH3I) and assessed their importance in its atmospheric budget using a synthesis of field observations. Measurements include those from NASA DC‐8 research flights over the United States and the North Atlantic, the AIRMAP long‐term ground‐observing network in New England, and a field campaign at Duke Forest, North Carolina. We found an average CH3I flux of ∼2,700 ng m−2 d−1 to the atmosphere from midlatitude vegetation and soils, a value similar in magnitude to previous estimates of the oceanic source strength. The large‐scale aircraft measurements of vertical profiles over the continental U.S. showed CH3I‐mixing ratios comparable to and greater than those observed over the North Atlantic. Overall, midlatitude terrestrial biomes appear to contribute 33 Gg yr−1 to the CH3I global budget

A large terrestrial source of methyl iodide

We have identified terrestrial sources of methyl iodide (CH3I) and assessed their importance in its atmospheric budget using a synthesis of field observations. Measurements include those from NASA DC-8 research flights over the United States and the North Atlantic, the AIRMAP long-term ground-observing network in New England, and a field campaign at Duke Forest, North Carolina. We found an average CH3I flux of ∼2,700 ng m-2 d-1 to the atmosphere from midlatitude vegetation and soils, a value similar in magnitude to previous estimates of the oceanic source strength. The large-scale aircraft measurements of vertical profiles over the continental U.S. showed CH3I-mixing ratios comparable to and greater than those observed over the North Atlantic. Overall, midlatitude terrestrial biomes appear to contribute 33 Gg yr-1 to the CH3I global budget. Copyright 2007 by the American Geophysical Union

Zebrafish Brain Ventricle Injection

Proper brain ventricle formation during embryonic brain development is required for normal brain function. Brain ventricles are the highly conserved cavities within the brain that are filled with cerebrospinal fluid. In zebrafish, after neural tube formation, the neuroepithelium undergoes a series of constrictions and folds while it fills with fluid resulting in brain ventricle formation. In order to understand the process of ventricle formation, and the neuroepithelial shape changes that occur at the same time, we needed a way to visualize the ventricle space in comparison to the brain tissue. However, the nature of transparent zebrafish embryos makes it difficult to differentiate the tissue from the ventricle space. Therefore, we developed a brain ventricle injection technique where the ventricle space is filled with a fluorescent dye and imaged by brightfield and fluorescent microscopy. The brightfield and the fluorescent images are then processed and superimposed in Photoshop. This technique allows for visualization of the ventricle space with the fluorescent dye, in comparison to the shape of the neuroepithelium in the brightfield image. Brain ventricle injection in zebrafish can be employed from 18 hours post fertilization through early larval stages. We have used this technique extensively in our studies of brain ventricle formation and morphogenesis as well as in characterizing brain morphogenesis mutants (1-3)

The social, family and medical backgrounds of children with kwashiorkor presenting at a teaching hospital

The social, fanilly and medical backgrounds of 53 children hospitalised with kwashiorkor were Compared with those of 106 children hospitalised for non-nutritional diseases to determine risk factors for severe nutritional disease in children presenting to a teaching hospital. The control children were matched for age, sex, race and the nonnutritional illness complicating the course of the children with kwashiorkor; in 80% of cases the reason for admission was either gastro-enteritis or pneumonia. A major difference between the groups was the educational status of the mothers. Only 57% of the mothers of the children with kwashiorkor were literate compared with 93% of the controls; 25% as opposed to 47% were married, and 36% as opposed to 72% received support from the father. There were no differences in the mothers' ages or use of contraception, or in the number of children they had. In all except 1 instance the child with kwashiorkor was the youngest or only child in the family, and the average sibling interval was 53 months. The types of dwellings occupied by the families were similar, but overcrowding was worse in the kwashiorkor group. Family income was below the household subsistence level in the vast majority of both groups, but significantly more of the kwashiorkor group had minimal cash income. Significantly fewer of the children with kwashiorkor had been breast-fed or adequately immunised, and 60% had previously been hospitalised for dehydrating diarrhoea. This study demonstrates that in an urban environInent the traditional factors of large families and displacement by a younger sibling are not associated with kwashiorkor. However, children likely to develop kwashiorkor can readily be identified for inclusion in nutritional prograInInes

Bromoform and dibromomethane measurements in the seacoast region of New Hampshire, 2002-2004

Atmospheric measurements of bromoform (CHBr3) and dibromomethane (CH2Br2) were conducted at two sites, Thompson Farm (TF) in Durham, New Hampshire (summer 2002-2004), and Appledore Island (AI), Maine (summer 2004). Elevated mixing ratios of CHBr3 were frequently observed at both sites, with maxima of 37.9 parts per trillion by volume (pptv) and 47.4 pptv for TF and AI, respectively. Average mixing ratios of CHBr3 and CH2Br2 at TF for all three summers ranged from 5.3-6.3 and 1.3-2.3 pptv, respectively. The average mixing ratios of both gases were higher at AI during 2004, consistent with AI's proximity to sources of these bromocarbons. Strong negative vertical gradients in the atmosphere corroborated local sources of these gases at the surface. At AI, CHBr3 and CH2Br2 mixing ratios increased with wind speed via sea-to-air transfer from supersaturated coastal waters. Large enhancements of CHBr3 and CH2Br2 were observed at both sites from 10 to 14 August 2004, coinciding with the passage of Tropical Storm Bonnie. During this period, fluxes of CHBr3 and CH2Br3 were 52.4 ± 21.0 and 9.1 ± 3.1 nmol m-2 h-1, respectively. The average fluxes of CHBr3 and CH2Br2 during nonevent periods were 18.9 ± 12.3 and 2.6 ± 1.9 nmol m-2 h-1, respectively. Additionally, CHBr3 and CH2Br2 were used as marine tracers in case studies to (1) evaluate the impact of tropical storms on emissions and distributions of marine-derived gases in the coastal region and (2) characterize the transport of air masses during pollution episodes in the northeastern United States. Copyright 2008 by the American Geophysical Union

Oceanic influence on atmospheric mercury at coastal and inland sites: a springtime noreaster in New England

Continuous measurements of elemental (Hg<sup>0</sup>) and reactive mercury were conducted at two sites in New Hampshire during a powerful April 2007 noreaster. During the most intense period of the storm, enhancements of ~30–50 ppqv in Hg<sup>0</sup> were observed at a coastal and a high elevation inland site. This enhancement occurred simultaneously with elevated mixing ratios of three marine tracers, CH<sub>3</sub>I, CH<sub>2</sub>Br<sub>2</sub> and CHBr<sub>3</sub>. These observations suggest a marine source of Hg<sup>0</sup>, possibly outgassing from the ocean surface during strong turbulence. The Hg<sup>0</sup> enhancement observed 100 km inland suggests that the impact of coastal storms on terrestrial Hg cycling may not be limited to near-shore environments. Combining Hg<sup>0</sup> and marine tracer measurements during the storm with estimates of oceanic tracer fluxes during previous strong storms yields an order-of-magnitude estimate of the oceanic source of Hg<sup>0</sup> during the storm (~7 ppqv h<sup>−1</sup>) which can account for the observed enhancement at the field sites

The Role of Voltage-Gated Calcium Channels in Neurotransmitter Phenotype Specification: Coexpression and Functional Analysis in Xenopus laevis

Calcium activity has been implicated in many neurodevelopmental events, including the specification of neurotransmitter phenotypes. Higher levels of calcium activity lead to an increased number of inhibitory neural phenotypes, whereas lower levels of calcium activity lead to excitatory neural phenotypes. Voltage-gated calcium channels (VGCCs) allow for rapid calcium entry and are expressed during early neural stages, making them likely regulators of activity-dependent neurotransmitter phenotype specification. To test this hypothesis, multiplex fluorescent in situ hybridization was used to characterize the coexpression of eight VGCC alpha 1 subunits with the excitatory and inhibitory neural markers xVGlut1 and xVIAAT in Xenopus laevis embryos. VGCC coexpression was higher with xVGlut1 than xVIAAT, especially in the hindbrain, spinal cord, and cranial nerves. Calcium activity was also analyzed on a single-cell level, and spike frequency was correlated with the expression of VGCC alpha 1 subunits in cell culture. Cells expressing Ca(V)2.1 and Ca(V)2.2 displayed increased calcium spiking compared with cells not expressing this marker. The VGCC antagonist diltiazem and agonist (-)BayK 8644 were used to manipulate calcium activity. Diltiazem exposure increased the number of glutamatergic cells and decreased the number of gamma-aminobutyric acid (GABA)ergic cells, whereas (2) BayK 8644 exposure decreased the number of glutamatergic cells without having an effect on the number of GABAergic cells. Given that the expression and functional manipulation of VGCCs are correlated with neurotransmitter phenotype in some, but not all, experiments, VGCCs likely act in combination with a variety of other signaling factors to determine neuronal phenotype specification. (C) 2014 Wiley Periodicals, Inc

Bone marrow and chelatable iron in patients with protein energy malnutrition

Objectives: To examine the iron status of malnourished children by comparing bone marrow iron deposits in children with protein energy malnutrition with those in well-nourished controls, and measuring chelatable urinary iron excretion in children with kwashiorkor. Design: Bone marrow iron was assessed histologicaHy in postmortem specimens from children with kwashiorkor or marasmus, and from controls. Twenty-four-hour urinary iron was measured in children with severe kwashiorkor, half of whom received 10 mg/kg of intramuscular desferrioxamine (DFO) on admission.  Setting: Red Cross War Memorial Children's Hospital, Cape Town. Subjects: Thirteen children with kwashiorkor, 6 with marasmus and 16 well-nourished children underwent bone marrow examination. Urinary iron excretion was assayed in 17 children with kwashiorkor. Results: Stainable iron was present in the bone marrow of half the children with kwashiorkor but in only 1 child in each of the other groups. The median iron excretion was 945.5 µg/24 hours in the DFO group compared with 28.5 µg/24 hours in the non-DFO group. Conclusions: There is an apparent excess of iron which may predispose to bacterial infections and free radicalmediated injury in children with kwashiorkor. S AFr Med J 1996; 86: 1410-141

Multi-year (2004–2008) record of nonmethane hydrocarbons and halocarbons in New England: seasonal variations and regional sources

Multi-year time series records of C<sub>2</sub>-C<sub>6</sub> alkanes, C<sub>2</sub>-C<sub>4</sub> alkenes, ethyne, isoprene, C<sub>6</sub>-C<sub>8</sub> aromatics, trichloroethene (C<sub>2</sub>HCl<sub>3</sub>), and tetrachloroethene (C<sub>2</sub>Cl<sub>4</sub>) from canister samples collected during January 2004–February 2008 at the University of New Hampshire (UNH) AIRMAP Observatory at Thompson Farm (TF) in Durham, NH are presented. The objectives of this work are to identify the sources of nonmethane hydrocarbons (NMHCs) and halocarbons observed at TF, characterize the seasonal and interannual variability in ambient mixing ratios and sources, and estimate regional emission rates of NMHCs. Analysis of correlations and comparisons with emission ratios indicated that a ubiquitous and persistent mix of emissions from several anthropogenic sources is observed throughout the entire year. The highest C<sub>2</sub>-C<sub>8</sub> anthropogenic NMHC mixing ratios were observed in mid to late winter. Following the springtime minimums, the C<sub>3</sub>-C<sub>6</sub> alkanes, C<sub>7</sub>-C<sub>8</sub> aromatics, and C<sub>2</sub>HCl<sub>3</sub> increased in early to mid summer, presumably reflecting enhanced evaporative emissions. Mixing ratios of C<sub>2</sub>Cl<sub>4</sub> and C<sub>2</sub>HCl<sub>3</sub> decreased by 0.7±0.2 and 0.3±0.05 pptv/year, respectively, which is indicative of reduced usage and emissions of these halogenated solvents. Emission rates of C<sub>3</sub>-C<sub>8</sub> NMHCs were estimated to be 10<sup>9</sup> to 10<sup>10</sup> molecules cm<sup>−2</sup> s<sup>−1</sup> in winter 2006. The emission rates extrapolated to the state of New Hampshire and New England were ~2–60 Mg/day and ~12–430 Mg/day, respectively. Emission rates of benzene, toluene, ethylbenzene, xylenes, and ethyne in the 2002 and 2005 EPA National Emissions Inventories were within ±50% of the TF emission rates