Concentrations and gas-particle partitioning of PCDD/Fs in the urban air of Dalian, China

PCDD/Fs in the urban air of Dalian, China were monitored with high-volume active sampler from November 2009 to October 2010. The concentration of Cl4-8DD/Fs ranged from 3065 to 49538 fg m(-3), with an average of 10249 fg m(-3). The international toxic equivalents (I-TEQ) value of that was 61.8-1182 fg m(-3), with an average of 235 fg m(-3), which was comparable to those in the other urban locations around the world. It was found that the Cl4-8DD/Fs appeared to be present mainly in the particle phase during winter, spring and autumn, while during summer which were dominantly in gas phase. The ratio of Cl4-8DD/Fs present in particle phase increased with the increasing level of chlorination. The concentrations of PCDFs and PCDDs decreased with the increase of chlorinated level, while the concentrations of 2,3,7,8-PCDDs congeners increased with the increase of chlorination level. The homolog profiles of the concentrations of PCDFs presented were higher than those of the PCDDs, which indicated the PCDD/Fs pollution source of the air in Dalian was characteristic for thermal source pollution. The correlation analysis of meteorological parameters with the concentrations of Cl4-8CDD/Fs was conducted using SPSS packages, and it was found that the ambient temperature and atmospheric pressure were important factors influence the concentration of PCDD/Fs in the air. The respiratory risk and intake dioxins of the residents around the sampling sites were studied in the paper. It was found that Junge-Pankow model was much more accurate in predicting the gas-particle partitioning behavior of PCDD/Fs homologues during winter, while the Harner-Bidleman model shows better agreement with the measured data during winter and summer

Evaluation of Tropical Herbaceous Legumes for Drought Resistance in Myanmar

Animal nutrition systems in the tropical and subtropical countries utilize a wide range of feedstuffs, mainly the crops and agricultural by-products, grasses, legumes, trees and shrubs. During the dry season, the crude protein concentration in the native grasses can drop below 3% crude protein (Atta-Krah and Reynolds, 1989). Fodder tree is not sufficient and is of low quality in Myanmar (Myo and Aye, 2007). Shrubs represent an enormous potential source of protein for ruminants in the tropics (Devendra, 1992). Browses are rich in nitrogen and minerals which are low in other conventional feeds of tropical regions. Herbaceous legume species play an important role in feeding ruminants worldwide. Herbaceous forage legume have been identified as potential protein supplements for ruminants since they contain high crude protein, minerals and vitamins needed for the growth of ruminal microbes (Norton and Poppi,1995). Herbaceous legumes can be grown as a relay within cereal crops or as a rotation with cereals. Herbaceous legumes can access ‎atmospheric ‎N‎ (‘fixation’)‎ through‎ bacterial‎ activity‎ in‎ root ‎nodules.‎ The‎ ‘fixed’ ‎N‎ becomes‎ available ‎to‎ the‎ legume and subsequent cereal crops. Herbaceous legumes are best planted from seed (Nulik et al., 2013). The aim of using herbaceous legumes in cropping systems is to increase animal productivity, particularly live weight gain in animals being prepared for market. Herbaceous legumes may be fed directly to animals as fresh material in the late wet and early dry seasons, with browse or tree legumes retained for later dry season feeding, or stored as hay and fed in the late dry or early wet seasons when the availability and quality of local feed is lower (Nulik et al., 2013). Legume based pastures give high individual animal performance for growth, fattening, reproduction and wool growth. Cattle live weight gain has been related positively to the proportion of legume in the sward (Mureithi et al., 1995). As pastures become mature, they are characterized by high content of fibre with a higher grade of lignifications and low protein content (Enoh et al., 2005). In Myanmar there is only 0.35% cultivated pasture area to that of cultivated acreages. The improvement and development of pasture is a necessity for Myanmar (Myo and Aye, 2007). For that reason it is needed to evaluate the yield herbaceous legumes for the potential use for ruminants in Myanmar

Selection of Suitable Varieties of Grasses for Myanmar

The basal feed resources for ruminants available in most developing countries in the tropics are crop residues, pasture from infertile land, for example communal land, or agro-industrial by-products. These are low in protein and of low digestibility. A major problem facing livestock producers in tropical areas is proper nutrition for their animals during the dry season when pastures, cereal residues and maize stover are limiting in nutritional quality. The researchers in Myanmar have tried to improve the nutritive value of fibrous agricultural residues. Aung Aung et al. (2006) supplemented the sesame and chickpea husk to bulls fed on urea-treated rice straw. One way of improving the utilisation of such crop residues is by proper supplementation with leguminous forages (Poppi and McLennan 1995). In most regions of Myanmar, the green forage is available during the rainfall and become shortage during dry season. Therefore, feedstuff for ruminant animals mainly has to depend upon the availability of agricultural by-products. Almost more than half of the livestock population of Myanmar is inhabited in dry zone and thus, to overcome the scarcity of the feedstuff during summer, the irrigation system was introduced in these areas for the development of agriculture. A simple and effective way to increase livestock production is to grow improved pastures. Throughout Myanmar, extensive areas of idle land could grow excellent pasture. At present, most of the “pastures” consist of low rank, poor quality grasses and a limited range of edible shrubs. During prolonged dry periods, grazing animals subsist on dry mature roughage of poor quality (Myo Kywe and Tin Mg Aye, 2007). Grass species, which can rapidly grow after the rain also having drought tolerance, would be very useful in the production system. There is still little information on the use of forage in Myanmar. It is needed to select the grass species which have drought resistance in Myanmar and thus this experiment was conducted to evaluate a range of introduced tropical grasses in the central dry zone of Myanmar

Epitaxial growth and anisotropy of La(O,F)FeAs thin films deposited by Pulsed Laser Deposition

LaFeAsO1-xFx thin films were deposited successfully on (001)-oriented LaAlO3 and MgO substrates from stoichiometric LaFeAsO1-xFx polycrystalline targets with fluorine concentrations up to x = 0.25 by PLD. Room temperature deposition and post annealing of the films yield nearly phase pure films with a pronounced c-axis texture and a strong biaxial in-plane orientation. Transport measurements show metallic resistance and onset of superconductivity at 11 K. Hc2(T) was determined by resistive measurements and yield Hc2 values of 3 T at 3.6 K for B||c and 6 T at 6.4 K for B||ab.Comment: 11 pages, 5 figure

Exploring hypotheses of the actions of TGF-beta 1 in epidermal wound healing using a 3D computational multiscale model of the human epidermis

In vivo and in vitro studies give a paradoxical picture of the actions of the key regulatory factor TGF-beta 1 in epidermal wound healing with it stimulating migration of keratinocytes but also inhibiting their proliferation. To try to reconcile these into an easily visualized 3D model of wound healing amenable for experimentation by cell biologists, a multiscale model of the formation of a 3D skin epithelium was established with TGF-beta 1 literature-derived rule sets and equations embedded within it. At the cellular level, an agent-based bottom-up model that focuses on individual interacting units ( keratinocytes) was used. This was based on literature-derived rules governing keratinocyte behavior and keratinocyte/ECM interactions. The selection of these rule sets is described in detail in this paper. The agent-based model was then linked with a subcellular model of TGF-beta 1 production and its action on keratinocytes simulated with a complex pathway simulator. This multiscale model can be run at a cellular level only or at a combined cellular/subcellular level. It was then initially challenged ( by wounding) to investigate the behavior of keratinocytes in wound healing at the cellular level. To investigate the possible actions of TGF-beta 1, several hypotheses were then explored by deliberately manipulating some of these rule sets at subcellular levels. This exercise readily eliminated some hypotheses and identified a sequence of spatial-temporal actions of TGF-beta 1 for normal successful wound healing in an easy-to-follow 3D model. We suggest this multiscale model offers a valuable, easy-to-visualize aid to our understanding of the actions of this key regulator in wound healing, and provides a model that can now be used to explore pathologies of wound healing

Monte Carlo Methods for Estimating Interfacial Free Energies and Line Tensions

Excess contributions to the free energy due to interfaces occur for many problems encountered in the statistical physics of condensed matter when coexistence between different phases is possible (e.g. wetting phenomena, nucleation, crystal growth, etc.). This article reviews two methods to estimate both interfacial free energies and line tensions by Monte Carlo simulations of simple models, (e.g. the Ising model, a symmetrical binary Lennard-Jones fluid exhibiting a miscibility gap, and a simple Lennard-Jones fluid). One method is based on thermodynamic integration. This method is useful to study flat and inclined interfaces for Ising lattices, allowing also the estimation of line tensions of three-phase contact lines, when the interfaces meet walls (where "surface fields" may act). A generalization to off-lattice systems is described as well. The second method is based on the sampling of the order parameter distribution of the system throughout the two-phase coexistence region of the model. Both the interface free energies of flat interfaces and of (spherical or cylindrical) droplets (or bubbles) can be estimated, including also systems with walls, where sphere-cap shaped wall-attached droplets occur. The curvature-dependence of the interfacial free energy is discussed, and estimates for the line tensions are compared to results from the thermodynamic integration method. Basic limitations of all these methods are critically discussed, and an outlook on other approaches is given

Comparisons on the nutritive values of local and introduced forages and feed mixture for ruminant feed in central dry zone of Myanmar

This study aimed to compare nutritive values of local (Sorghum) and introduced (Mombasa) forages and their feed mixtures for ruminant feed in central dry zone of Myanmar. Sorghum based feed mixtures (FeedMix-1, 2 and 3) were the commonly used feed mixtures for cattle in dry zone of Myanmar and other feed mixtures (FeedMix-4, 5 and 6) were based on Mombasa. The lower CP and higher fibre contents (P<0.05) were observed in sorghum and its feed mixtures. The highest gas volumes (P<0.05) were observed in the FeedMix-4 and 6, and then the lowest gas volume (P<0.05) was observed in FeedMix-3. The gas production from quickly soluble fraction (a) of sorghum was significantly higher (P<0.05) than that of Mombasa, inversely the gas production from insoluble fraction (b) of sorghum was significantly lower (P<0.05) than that of Mombasa. Moreover, potential gas production (a+b), ME, OMD and SCFA of sorghum were also significantly lower (P<0.05) than those of Mombasa. The value of “a” was lowest (P<0.05) in FeedMix-1, whereas the highest value was found in FeedMix-6. The lowest values (P<0.05) of “b”, “a+b”, ME, OMD and SCFA were observed in FeedMix-3 and the highest values (P<0.05) of those parameters were found in FeedMix-4. Thus, the higher nutritive values observed in the introduced forage, Mombasa and its feed mixtures were indicating that Mombasa should be used instead of sorghum for the feed of cattle in dry zone of Myanmar.&nbsp