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(1) Sphagnum is an important genus of bryophytes holding 10-15 % of the terrestrial carbon stock. With climate change a drier surface may increase the abundance of vascular plants on peatlands, so shading of Sphagnum may increase. Here we describe growth cabinet experiments to reveal the effects of shading on interactions among mixtures of three species: S. capillifolium, S. palustre (hummock species), and S. fallax (a hollow species). We measured the six traits: growth in length, growth as increase in dry mass, side-shoot production, nitrogen and carbon proportion of the capitulum dry mass, and C:N ratio in the capitulum. (2) Shading had no effect on biomass production or side-shoot production but increased height increment in all three species. It also increased the C and N proportions of total dry mass but decreased C:N ratio in the capitula. (3) Neighbours of a different species reduced biomass and side-shoot production in the two hummock species but had no effect on the hollow species. (4) All three species showed interaction between shading and neighbour in two or more plant traits. S. fallax showed competitive advantage over S. palustre in no-shading treatments and over S. capillifolium in moderate shading treatments. In addition, under deep shading, S. fallax showed a competitive advantage over both hummock species. A clear competitive hierarchy S. fallax>S. capillifolium>S. palustre emerged which was consistent with the hierarchy of side-shoot production. (5) The results suggest that all the species appear to tolerate deep shade (for a few months at least). In a shaded environment, especially under deeply shaded conditions, S. fallax retains its dominance in hollow habitats (if water availability is guaranteed) by virtue of its advantage in side-shoot production. (6) If shading increases then the abundance of different Sphagnum species is likely to change. [ABSTRACT FROM AUTHOR]

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A study was conducted to compare growth and survival of Hucho taimen larvae from 21 to 76 days after hatch ( DAH) fed one of three diets: formulated feed alone (group F); a co-feeding diet of water fleas, tubifex and formulated feed (group C); or live food of water fleas and tubifex (group L), and to investigate the potential use of dietary L-alanyl-L-glutamine (L- AG) in larval taimen for a more nutritious starter diet. Triplicate groups of 5000 fish were randomly assigned to each aquarium provided with water from a flow-through system, and fed to apparent satiation. The results show that larvae can feed efficiently on floating crumbled particles of formulated feed. Weight gain of larvae fed only formulated feed was significantly lower than other groups at 34 DAH (P < 0.05). At the end of the experiment, weight gain reached the highest value in group F and was lowest in group L (P < 0.05). Condition factor reached the highest values in group F and lowest in group C (P < 0.05). Specific growth rate was in accordance with weight gain at 76 DAH. Survival showed no differences among the groups (P > 0.05). In conclusion, H. taimen larvae can be fed formulated feed alone and L- AG may be used as a feeding attractant during the weaning process, which should lead to a better understanding in the rearing improvement in the feeding of larvae. [ABSTRACT FROM AUTHOR]

The electronic structure of the iron-based superconductor Ba2Ti2Fe2As4O (Tonsetc = 23.5 K) has been investigated by using angle-resolved photoemission spectroscopy and combined local density approximation and dynamical mean field theory calculations. The electronic states near the Fermi level are dominated by both the Fe 3d and Ti 3d orbitals, indicating that the spacer layers separating different FeAs layers are also metallic. By counting the enclosed volumes of the Fermi surface sheets, we observe a large self-doping effect; i.e., 0.25 electrons per unit cell are transferred from the FeAs layer to the Ti2As2O layer, leaving the FeAs layer in a hole-doped state. This exotic behavior is successfully reproduced by our dynamical mean field calculations, in which the self-doping effect is attributed to the electronic correlations in the 3d shells. Our work provides an alternative route of effective doping without element substitution for iron-based superconductors. [ABSTRACT FROM AUTHOR]

Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of nitrous acid (HONO) and its precursor NO2 (nitrogen dioxide) as well as aerosols have been performed daily in Beijing city centre (39.98° N, 116.38° E) from July 2008 to April 2009 and at the suburban site of Xianghe (39.75° N, 116.96° E) located ~60 km east of Beijing from March 2010 to December 2012. This extensive dataset allowed for the first time the investigation of the seasonal cycle of HONO as well as its diurnal variation in and in the vicinity of a megacity. Our study was focused on the HONO and NO2 near-surface concentrations (0-200m layer) and total vertical column densities (VCDs) and also aerosol optical depths (AODs) and extinction coefficients retrieved by applying the Optimal Estimation Method to the MAX-DOAS observations. Monthly averaged HONO near-surface concentrations at local noon display a strong seasonal cycle with a maximum in late fall/winter (~0.8 and 0.7 ppb at Beijing and Xianghe, respectively) and a minimum in summer (~0.1 ppb at Beijing and 0.03 ppb at Xianghe). The seasonal cycles of HONO and NO2 appear to be highly correlated, with correlation coefficients in the 0.7-0.9 and 0.5-0.8 ranges at Beijing and Xianghe, respectively. The stronger correlation of HONO with NO2 and also with aerosols observed in Beijing suggests possibly larger role of NO2 conversion into HONO in the Beijing city center than at Xianghe. The observed diurnal cycle of HONO near-surface concentration shows a maximum in the early morning (about 1 ppb at both sites) likely resulting from night-time accumulation, followed by a decrease to values of about 0.1-0.4 ppb around local noon. The HONO/NO2 ratio shows a similar pattern with a maximum in the early morning (values up to 0.08) and a decrease to ~0.01-0.02 around local noon. The seasonal and diurnal cycles of the HONO near-surface concentration are found to be similar in shape and in relative amplitude to the corresponding cycles of the HONO total VCD and are therefore likely driven mainly by the balance between HONO sources and the photolytic sink, whereas dilution effects appear to play only a minor role. The estimation of OH radical production from HONO and O3 photolysis based on retrieved HONO near-surface concentrations and calculated photolysis rates indicate that in the 0-200m altitude range, HONO is by far the largest source of OH radicals in winter as well as in the early morning at all seasons, while the contribution of O3 dominates in summer from mid-morning until mid-afternoon. [ABSTRACT FROM AUTHOR]

Ground-based measurements of scattered sunlight by the Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) have been carried out at an urban site (39.95° N, 116.32° E) in Beijing megacity since 6 August 2008. In this study, we retrieved the tropospheric NO2 vertical column densities (VCDs) over Beijing from these MAX-DOAS observations from August 2008 to September 2011. Over this period, the daytime (08:00-17:00 Beijing Time (BJT, which equals UTC+8)) mean tropospheric NO2 VCDs varied from 0.5 to 13.3 with an average of 3.6 during summertime, and from 0.2 to 16.8 with an average of 5.8 during wintertime, all in units of 1016 molecules cm-2. The average diurnal variation patterns of tropospheric NO2 over Beijing appeared to be rather different from one season to another, indicating differences in the emission strength and atmospheric lifetime. In contrast to previous studies, we find a small weekly cycle of the tropospheric NO2 VCD over Beijing. The NO2 VCD in the late afternoon was the largest on Saturday and the lowest on Sunday, and in the morning it reached a clear maximum onWednesday.We also find a post-Olympic Games effect, with 39-54% decrease in the tropospheric NO2 VCD over Beijing estimated for August of 2008, compared to the following years. The tropospheric NO2 VCDs derived by our ground MAX-DOAS measurements show a good correlation with SCIAMACHY and OMI satellite data. However, compared with the MAXDOAS measurements, the satellite observations underestimate the tropospheric NO2 VCDs over Beijing systematically, by 43% for SCIAMACHY and 26-38% for OMI (DOMINO v2.0 and DOMINO v1.02). Based on radiative transfer simulations, we show that the aerosol shielding effect can explain this underestimation, while the gradient smoothing effect caused by the coarse spatial resolution of the satellite observations could play an additional role. [ABSTRACT FROM AUTHOR]

Ground-based measurements of scattered sunlight by the Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) have been carried out at an urban site (39.95° N, 116.32° E) in Beijing megacity since 6 August 2008. In this study, we retrieved the tropospheric NO2 vertical column densities (VCDs) over Beijing from these MAX-DOAS observations from August 2008 to September 2011. Over such period, the daytime (08:00-17:00 h Beijing Time) mean tropospheric NO2 VCDs varied from 0.5 to 13.3 with an average of 3.6 during summertime, and from 0.2 to 16.8 with an average of 5.8 during wintertime, all in units of 1016 moleculescm-2 . The average diurnal variation patterns of tropospheric NO2 over Beijing appeared to be rather different from one season to another, indicating differences in the mixing layer height, the atmospheric lifetime and the emission patterns. In contrast to previous studies, we find a small weekly cycle of the tropospheric NO2 VCD over Beijing. The NO2 VCD in the late afternoon was the largest on Saturday and the lowest on Sunday, and in the morning it reached a clear maximum on Wednesday. We also find a post Olympic Games effect, with 39-54% decrease in the tropospheric NO2 VCD over Beijing estimated for August of 2008, compared to the following years. The tropospheric NO2 VCDs derived by our ground MAX-DOAS measurements show a good correlation with SCIAMACHY and OMI satellite data. However, compared with the MAX-DOAS measurements, the satellite observations underestimate the tropospheric NO2 VCDs over Beijing systematically, by 43% for SCIAMACHY and 26-38% for OMI (DOMINO v2.0 and DOMINO v1.02). Based on radiative transfer simulations, we show that the aerosol shielding effect can explain this underestimation, while the gradient smoothing effect caused by the coarse spatial resolution of the satellite observations could play an additional role. [ABSTRACT FROM AUTHOR]

In the past decades, regional air pollution characterized by photochemical smog and grey haze-fog has become a severe environmental problem in China. To investigate this, a field measurement campaign was performed in the Huabei region, located between 32° -42° N latitude in Eastern China, during the period 2 April-16 May 2006 as part of the project "Influence of Pollution on Aerosols and Cloud Microphysics in North China" (IPAC-NC). It was found that strong pollution emissions from urban and industrial centers accumulate in the lower atmosphere over the core area of Huabei. We observed widespread, very high SO2 mixing ratios, about 20-40 ppbv at 0.5-1.5 km altitude and 10-30 ppbv at 1.5-3.0 km altitude. Average CO mixing ratios were 0.65-0.7 ppmv at 0.5-1.5 km altitude, and very high CO around 1 ppmv was observed during some flights, and even higher levels at the surface. The high pollution concentrations were associated with enhanced levels of OH and HO2 radicals, calculated with a chemical box model constrained by the measurements. The maximum OH concentration was 6.9 x 106 molecules cm-3 (~0.29 pptv) at an altitude of ~1 km, remarkably higher than 5.4 x 106 molecules cm-3 (~0.22 pptv) at the surface. In the upper part of the boundary layer and in the lower free troposphere, high CO and SO2 competed with relatively less NO2 in reacting with OH, being efficiently recycled through HO2, preventing a net loss of HOx radicals. In addition to reactive hydrocarbons and CO, the oxidation of SO2 caused significant ozone production over Huabei (up to ~13% or 2.0 ppbv h-1 at ~0.8 km). The enhanced OH increased the formation of condensable species by the oxidation of volatile precursor gases, adding to the high loadings of mineral dust particles. Our results indicate that the lower atmosphere over Huabei is not only strongly polluted but also acts as an oxidation pool over Eastern China. [ABSTRACT FROM AUTHOR]

Huabei is a part of eastern China located between 32° N and 42° N latitude. Administratively it is a region including Beijing and Tianjin Municipalities, Hebei and Shanxi Provinces, and Inner-Mongolia Autonomous Region. Over the past decades, the region has experienced dramatic changes in air quality and climate, and has become a major focus of environmental research in China. Here we present a new inventory of air pollutant emissions in Huabei for the year 2003 developed as part of the project Influence of Pollution on Aerosols and Cloud Microphysics in North China (IPAC-NC). Our estimates are based on the data from the statistical yearbooks of state and provinces as well as local districts including major sectors and activities of power generation, industrial energy consumption, industrial processing, civil energy consumption, crop straw burning, oil and solvent evaporation, manure, and motor vehicles. The emission factors are selected from a variety of literature and those from local measurements in China are used whenever available. The estimated total emissions in the Huabei administrative region in 2003 are 4.73 Tg SO2, 2.72 Tg NOx (in equivalent NO2), 1.77 Tg VOC, 24.14 Tg CO, 2.03 Tg NH3, 4.57 Tg PM10, 2.42 Tg PM2.5, 0.21 Tg EC, and 0.46 Tg OC. For model convenience, we consider a larger Huabei region with Shandong, Henan and Liaoning Provinces included in our inventory. The estimated total emissions in the larger Huabei region in 2003 are: 9.55 Tg SO2, 5.27 Tg NOx (in equivalent NO2), 3.82 Tg VOC, 46.59 Tg CO, 5.36 Tg NH3, 10.74 Tg PM10, 5.62 Tg PM2.5, 0.41 Tg EC, and 0.99 Tg OC. The estimated emission rates are projected into grid cells at a horizontal resolution of 0.1° latitude by 0.1° longitude. Our gridded emission inventory consists of area sources, which are classified into industrial, civil, traffic, and straw burning sectors, and large industrial point sources, which include 345 sets of power plants, iron 25 and steel plants, cement plants, and chemical plants. The estimated regional NO2 emissions are about 2-3% (administrative Huabei region) or 5% (larger Huabei region) of the global anthropogenic NO2 emissions. We compare our inventory (IPAC-NC) with a global emission inventory EDGAR-CIRCE and an Asian emission inventory INTEX-B. While the total emissions in Huabei are comparable with each other, large differences up to a factor of 2-3 for local emissions in the areas such as the Beijing and Tianjin megacities are found. We expect that our inventory will provide more practical spatial distributions of air pollutant emissions in 5 the Huabei region of China and can be applied for air pollution and chemistry research on this region in the future. [ABSTRACT FROM AUTHOR]

The article presents a study that determines the diversity of diazoptroph communities in soil which had undergone continuous and rotational cropping of soybeans. It states that the study considered the presence of the biological marker nitrogenase nifH for the detection of diazotrophs in soils located in China. Results obtained through the application of polymerase chain reaction (PCR) revealed 86 kinds of the nifH gene. It affirms that tillage affects bacterial diversity.

We investigated aerosol hygroscopic growth property and its influence on scattering coefficient using M9003 nephelometers in coupling with a relative humidity controlled inlet system at a rural site near Beijing mega-city (Jingjintang) from 24th April to15th May 2006. Inlet relative humidity was controlled in an increasing range of 40%-90% while the aerosol hygroscopic growth factor, f (RH=80%), varied in a range of 1.07-2.35 during the measurement. Estimated periodic mean values of aerosol hygroscopic growth factors are 1.27-1.34, 1.17-1.23, 1.55-1.59 and 2.33-2.48 for clean, dust, urban pollution and mixed pollution periods respectively. An examination of chemical composition of daily filter samples highlighted that aerosol hygroscopicity was generally enhanced with the increasing ratio of ammonium sulfate (AS) to organic matter (OMC). Furthermore, strong hygroscopic organic aerosols were observed on 11th (f (RH=80%)=2.23) and 15th (f (RH=80%)=2.21) of May with organic carbon proportions of PM2.1 reaching 42.3% and 43.0% respectively. Back-trajectory analysis indicated that solar radiation and vertical convective movement along the air mass pathway might strongly influence the hygroscopic properties of organic matter. [ABSTRACT FROM AUTHOR]

Objective: To assess the relative effect of different antihypertensive agents on proteinuria and renal function in patients with diabetes.Data Sources: We used MEDLINE and bibliographies in recent articles to identify studies of the effects of antihypertensive agents on renal function in patients with diabetes.Study Selection: We selected 100 controlled and uncontrolled studies that provided data on renal function, proteinuria, or both, before and after treatment with an antihypertensive agent.Data Extraction: Data on blood pressure, renal function, proteinuria, patient characteristics (for example, age, sex, and type of diabetes), and study design (for example, random allocation and the use of a placebo) were extracted from selected studies.Data Synthesis: Multiple linear regression analysis indicated that angiotensin-converting enzyme (ACE) inhibitors decreased proteinuria independent of changes in blood pressure, treatment duration, and the type of diabetes or stage of nephropathy, as well as study design (P < 0.0001). Reductions in proteinuria from other antihypertensive agents could be entirely explained by changes in blood pressure. Blood pressure reduction in itself was associated with a relative increase in glomerular filtration rate (regression coefficient [+/- SE], 3.70 +/- .92 mL/min for each reduction of 10 mm Hg in mean arterial pressure; P = 0.0002); however, compared with other agents, ACE inhibitors had an additional favorable effect on glomerular filtration rate that was independent of blood pressure changes (3.41 +/- 1.71 mL/min; P = 0.05).Conclusion: Angiotensin-converting enzyme inhibitors can decrease proteinuria and preserve glomerular filtration rate in patients with diabetes. These effects occur independent of changes in systemic blood pressure. [ABSTRACT FROM AUTHOR]

Objective: To determine whether it is safe to electively discontinue cyclosporine therapy after renal transplantation.Data Sources: MEDLINE and bibliographies from recent publications.Study Selection: Controlled trials assessing the rate of acute rejection, graft loss, and mortality after elective cyclosporine withdrawal.Data Extraction: We compared outcomes in patients who underwent withdrawal from cyclosporine treatment with patients who were not withdrawn (part 1), and in a separate analysis (part 2), with patients who never received cyclosporine.Data Synthesis: In part 1 of the meta-analysis, consisting of 10 randomized and seven nonrandomized trials, there was a greater combined rate of acute rejection among patients in whom cyclosporine was withdrawn compared with control patients who continued to receive cyclosporine (weighted difference in episodes per patient, 126; 95% confidence interval [CI], 0.085 to 0.167; P < .001). However, there were no differences in graft loss (weighted difference in grafts lost per patient per year, -0.009; 95% CI, -0.022 to 0.004; P = 0.19) or mortality (weighted difference in deaths per patient per year, -0.005; 95% CI, -0.016 to 0.006; P = .40) attributable to cyclosporine withdrawal. In part 2 of the meta-analysis, consisting of three randomized and three nonrandomized trials, the combined rate of graft loss for patients who were withdrawn from cyclosporine was not significantly different vs control patients who never received cyclosporine (weighted difference in grafts lost per patient per year, -0.020; 95% CI, -0.043 to 0.003; P = .08). However, when the three randomized trials were analyzed separately, graft survival was better in patients who were withdrawn from cyclosporine (weighted difference in grafts lost per patient per year, 0.0382; 95% CI, 0.0002 to 0.0762; P = .049). None of the outcomes was affected by the timing or manner of the cyclosporine withdrawal.Conclusions: The increased incidence of acute rejection following elective cyclosporine withdrawal does not affect short-term graft or patient survival after renal transplantation. Whether long-term consequences will outweigh the benefits of elective withdrawal remains to be determined. [ABSTRACT FROM AUTHOR]

We report on two results from our computational studies in quantum level statistics as a contribution to mesoscopic physics: (i) parametric motion of complex quantum levels and its dynamic treatment of second-derivative distribution for neighboring pairs (the so-called curvature distribution); (ii) intermediate statistics for long-range level correlation which exhibits a fractional power law, i.e., another manifestation of the fractional-power dependence like Sβ (0<β<1) familiar to Brody's distribution, in the number variance and the Δ-statistics of Dyson-Mehta. [ABSTRACT FROM AUTHOR]

A series of Si6-xAlxOxN8-x with different x values (x=0-4·2) was obtained by pressureless sintering using Al2O3 and AlN as additives. The influences of different x values on the dielectric properties of Si6-xAlxOxN8-x were investigated in detail. It was found that the difference in the dielectric properties of Si6-xAlxOxN8-x was mainly due to the simultaneous dissolution of Al2O3 and AlN in β-Si3N4. The dielectric constant increases with equivalent substitution of Al-O for Si-N. The high dielectric constant could be attributed to the ionic relaxation polarisation. [ABSTRACT FROM AUTHOR]

One-dimensional chains consisting of crystalline Fe3O4 nanoparticles have been synthesized by using a polyacrylic acid template method. The characterizations of composition, structure, and magnetic property of the chains are performed. The formation mechanism of Fe3O4 nanocrystal chains is proposed to be a polymer template and magnetostatic interaction. In a weak magnetic field, the synthesized nanochains can be reorganized. The as-synthesized nanochains are ferromagnetic at room temperature with lower saturation magnetization and higher coercivity value than those of bulk Fe3O4, which could have potential applications in nanosensors for rapid and sensitive detection of biologic or chemical molecules. [ABSTRACT FROM AUTHOR]

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111). [ABSTRACT FROM AUTHOR]