Rufibacter latericius sp. nov., isolated from Baiyang Lake.

A novel Gram-stain-negative, strictly aerobic, rod-shaped, brick red-pigmented bacterium, designated R-22-1 c-1T, was isolated from water from Baiyang Lake, Hebei Province, PR China. The strain was able to grow at 20-30 °C (optimum, 30 °C) and pH 6-7 (optimum, pH 6) in Reasoner's 2A medium. 16S rRNA gene sequence and phylogenetic analyses of R-22-1 c-1T revealed closest relationships to Rufibacter immobilis MCC P1T (97.8 %), Rufibacter sediminis H-1T (97.9 %) and Rufibacter glacialis MDT1-10-3T (97.0 %), with other species of the genus Rufibacter showing less than 97.0 % sequence similarity. The predominant polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids and three unidentified lipids. The major cellular fatty acids were iso-C15 : 0, C15 : 1 ω6c, C17 : 1 ω6c, anteiso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 4 (iso-C17 : 1I and/or anteiso-C17 : 1B). The respiratory quinone was MK-7. The draft genome of R-22-1 c-1T was 5.6 Mbp in size, with a G+C content of 50.2 mol%. The average nucleotide identity and digital DNA-DNA hybridization relatedness values between strain R-22-1 c-1T and related type strains were R. immobilis MCC P1T (77.2 and 21.8 %), R. sediminis H-1T (81.6 and 21.4 %) and R. tibetensis 1351T (78.5 and 22.9 %). Based on these phylogenetic, chemotaxonomic and genotypic results, strain R-22-1 c-1T represents a novel species in the genus Rufibacter, for which the name Rufibacter latericius sp. nov. is proposed. The type strain is R-22-1 c-1T (=CGMCC 1.13570T=KCTC 62781T).

Impact of multiple-scale circulation interactions on the spring diurnal precipitation over Luzon.

This study examines the spatiotemporal characteristics of diurnal precipitation over Luzon and the nearby oceans in boreal spring. The study focuses on exploring the impact of the interaction between large- and local-scale circulation changes on the modulation of diurnal precipitation. We analyze the satellite precipitation data obtained from the Tropical Rainfall Measuring Mission and Global Precipitation Measurement Mission during the spring (March-May) of 2001-2019. The results show that the spring diurnal precipitation over Luzon and the nearby oceans consists of a clear eastward propagation signal. The direction of this propagation is opposite to that of the prevailing low-level easterly wind in spring and differs from the well-known westward propagation direction of diurnal precipitation over Luzon in summer. Diagnoses of the possible maintenance mechanisms suggest that the eastward propagation diurnal precipitation can be attributed to the interaction between the topography and multiple-scale circulation changes, including the mountain-valley breeze, island-scale land-sea breeze (LSB), large-scale LSB-like circulation, and mid-to-upper-level prevailing wind fields. This finding highlights the importance of considering multiple-scale circulation changes in the modulation of spring diurnal precipitation over the East Asia-western North Pacific region.

Relationship between the Interannual Variations of Summer Convective Afternoon Rainfall Activity in Taiwan and SSTA(Niño3.4) during 1961-2012: Characteristics and Mechanisms.

This study examines the interannual variation of the Convective Afternoon Rainfall (CAR) activity (including frequency and intensity) in Taiwan during the summers (JJA) of 1961-2012 with a focus on identifying its relationship with the changes in sea surface temperature anomalies over the Niño3.4 region [SSTA(Niño3.4)] and the underlying physical mechanisms. Our analyses show that during the colder (warmer) phase of SSTA(Niño3.4), the subtropical high system over the region east of Taiwan is enhanced (weakened), the local surface wind convergence is enhanced (weakened), and the local thermal instability is enhanced (weakened), which facilitates (suppresses) the formation of CAR in Taiwan. This consistent negative relationship between the interannual variation of CAR frequency in Taiwan and SSTA(Niño3.4) occurs throughout 1961-2012. In contrast, the relationship between the interannual variation of CAR intensity in Taiwan and SSTA(Niño3.4) changed from positively correlated to negatively correlated in the late 1980s. This change is attributed to the change in the moisture supply for maintaining the CAR intensity in Taiwan from an increase (decrease) in the warmer (colder) phase of SSTA(Niño3.4) before the mid-1980s to the opposite after the late 1980s. These findings highlight how the rainfall characteristics in East Asia may change in response to changes in SSTA(Niño3.4).

Interannual variation of springtime biomass burning in Indochina: Regional differences, associated atmospheric dynamical changes, and downwind impacts.

During March and April, widespread burning occurs across farmlands in Indochina in preparation for planting at the monsoon onset. The resultant aerosols impact the air quality downwind. In this study, we investigate the climatic aspect of the interannual variation of springtime biomass burning in Indochina and its correlation with air quality at Mt. Lulin in Taiwan using long-term (2005-2015) satellite and global reanalysis data. Based on empirical orthogonal function (EOF) analysis, we find that the biomass burning activities vary with two geographical regions: northern Indochina (the primary EOF mode) and southern Indochina (the secondary EOF mode). We determine that the variation of biomass burning over northern Indochina is significantly related with the change in aerosol concentrations at Mt. Lulin. This occurs following the change in the so-called India-Burma Trough in the lower and middle troposphere. When the India-Burma Trough is intensified, a stronger northwesterly wind (to the west of the trough) transports the dryer air from higher latitude into northern Indochina, and this promotes local biomass burning activities. The increase in upward motion to the east of the intensified India-Burma Trough lifts the aerosols, which are transported toward Taiwan by the increased low-level westerly jet. Further diagnoses revealed the connection between the India-Burma Trough and the South Asian jet's wave train pattern as well as the previous winter's El Niño-Southern Oscillation phase. This information highlights the role of the India-Burma Trough in modulating northern Indochina biomass burning and possibly predicting aerosol transport to East Asia on the interannual time scale.

Fabrication of Ni-silicide/Si heterostructured nanowire arrays by glancing angle deposition and solid state reaction.

This work develops a method for growing Ni-silicide/Si heterostructured nanowire arrays by glancing angle Ni deposition and solid state reaction on ordered Si nanowire arrays. Samples of ordered Si nanowire arrays were fabricated by nanosphere lithography and metal-induced catalytic etching. Glancing angle Ni deposition deposited Ni only on the top of Si nanowires. When the annealing temperature was 500°C, a Ni3Si2 phase was formed at the apex of the nanowires. The phase of silicide at the Ni-silicide/Si interface depended on the diameter of the Si nanowires, such that epitaxial NiSi2 with a {111} facet was formed at the Ni-silicide/Si interface in Si nanowires with large diameter, and NiSi was formed in Si nanowires with small diameter. A mechanism that is based on flux divergence and a nucleation-limited reaction is proposed to explain this phenomenon of size-dependent phase formation.

Nickel induces oxidative stress and genotoxicity in human lymphocytes.

In order to elucidate the oxidative effects and genotoxicity of nickel on human lymphocytes in vitro, we report the level of intracellular reactive oxygen species (ROS), lipid peroxidation, hydroxyl radical ((*)OH), and DNA damage in human lymphocytes after acute exposure to inorganic nickel. NiCl(2) appeared to increase the formation of the fluorescent oxidized compound dichlorofluorescein (DCF). Lipid peroxidation in lymphocytes significantly increased compared to control. 2,3- and 2,5-DHB increased markedly in a concentration-dependent manner. Single-strand DNA breakage induced by Ni in lymphocytes was evaluated by Comet assay. Significant increase in DNA damage score (arbitrary units) showed a dose-related elevation after treatment with NiCl(2). NiCl(2) induced lipid peroxidation at 0.5 mM but had no effect on DNA strand breakage. These results support the emerging concept that NiCl(2)-induced oxidative stress and genotoxicity may be caused by oxygen radical intermediates. NiCl(2)-induced DNA strand breakage is related to the generation of the (*)OH radical.