Abrupt climatic events during the last glacial-interglacial transition in Alaska

Evidence is mounting that abrupt climatic shifts occurred during the last glacial-interglacial transition (LGIT) in the North Atlantic and other regions. However, few high-resolution climatic records of the LGIT exist from the high latitudes of the North Pacific rim. We analyzed lake sediments from southwestern Alaska for biogenic silica, organic carbon, organic nitrogen, diatom assemblages, and compound-specific hydrogen isotopes. Results reveal climatic changes coincident with the Younger Dryas, Intra-Allerod Cold Period, and Pre-Boreal Oscillation. However, major discrepancies exist in the paleoclimate patterns of the Bolling-Allerod interstadial between our data and the GISP2 18O record from Greenland, and causes are uncertain. These data suggest that the North Pacific and North Atlantic experienced similar reversals during climatic warming of the LGIT but that the Bolling-Allerod cooling trend in the GISP2 18O record is probably not a hemispheric or global pattern

Multi-Innovation Stochastic Gradient Identification Algorithm for Hammerstein Controlled Autoregressive Autoregressive Systems Based on the Key Term Separation Principle and on the Model Decomposition

An input nonlinear system is decomposed into two subsystems, one including the parameters of the system model and the other including the parameters of the noise model, and a multi-innovation stochastic gradient algorithm is presented for Hammerstein controlled autoregressive autoregressive (H-CARAR) systems based on the key term separation principle and on the model decomposition, in order to improve the convergence speed of the stochastic gradient algorithm. The key term separation principle can simplify the identification model of the input nonlinear system, and the decomposition technique can enhance computational efficiencies of identification algorithms. The simulation results show that the proposed algorithm is effective for estimating the parameters of IN-CARAR systems

A novel polymorphism in the 3′ untranslated region of rabbit TAS1R1 is associated with growth performance and carcass traits but not meat quality

The aim of this study was to investigate the relationship between polymorphisms of the 3′ untranslated region of TAS1R1 and growth traits, carcass traits, and meat quality traits in rabbit. We detected one single nucleotide polymorphism located at 9120 bp (g.9120A>C) in the 3′ untranslated region of TAS1R1 gene by using polymerase chain reaction sequencing. The novel mutation g.9120A>C was subsequently genotyped by MassArray system (Sequenom iPLEX assay) in 249 samples of three breeds (Hyla, 91 animals; Champagne, 84 animals; Tianfu Black, 74 animals). Association analysis suggested that the individuals with AC genotype showed greater body weight at 70 d of age (P < 0.01), body weight at 84 d of age (P < 0.05), and average daily weight gain from 28 to 84 d of age (P < 0.05) than AA. In addition, the individuals with AC genotype had a lower eviscerated slaughter percentage (P < 0.05) and semieviscerated slaughter percentage (P < 0.05). However, association of the genotypes with other production traits was not observed. The results indicate TAS1R1 is one of the candidate genes affecting growth performance and dressing percentage in rabbits, and this may be of potential use in marker-assisted selection for meat quality traits in rabbits.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Radiocarbon dating of individual lignin phenols: A new approach for establishing chronology of late quaternary lake sediments

The reliability of chronology is a prerequisite for meaningful paleoclimate reconstructions from sedimentary archives. The conventional approach of radiocarbon dating bulk organic carbon in lake sediments is often hampered by the old carbon effect, i.e., the assimilation of ancient dissolved inorganic carbon (DIC) derived from carbonate bedrocks or other sources. Therefore, radiocarbon dating is ideally performed on organic compounds derived from land plants that use atmospheric CO2 and rapidly delivered to sediments. We demonstrate that lignin phenols isolated from lake sediments using reversed phase high performance liquid chromatography (HPLC) can serve as effective 14C dating materials for establishing chronology during the late Quaternary. We developed a procedure to purify lignin phenols, building upon a published method. By isolating lignin from standard wood reference substances, we show that our method yields pure lignin phenols and consistent ages as the consensus ages and that our procedure does not introduce radiocarbon contamination. We further demonstrate that lignin phenol ages are compatible with varve counted and macrofossil dated sediment horizons in Steel Lake and Fayetteville Green Lake. Applying the new method to lake sediment cores from Lake Qinghai demonstrates that lignin phenol ages in Lake Qinghai are consistently younger than bulk total organic carbon (TOC) ages which are contaminated by old carbon effect. We also show that the age offset between lignin and bulk organic carbon differs at different Lake Qinghai sedimentary horizons, suggesting a variable hard water effect at different times and that a uniform age correction throughout the core is inappropriate. © 2010 American Chemical Society

Contrasting early Holocene temperature variations betweenmonsoonal East Asia and westerly dominated Central Asia

Numerous studies have demonstrated that there are major differences in the timing of maximum Holocene precipitation between the monsoonal East Asia and westerly dominated Central Asia, but it is unclear if the moisture differences are also associated with corresponding temperature contrasts. Here we present the first alkenone-based paleotemperature reconstructions for the past 21 kyr from Lake Balikun, central Asia. We show, unlike the initiation of Holocene warm conditions at &sim;11 kyr BP in the monsoon regions, the arid central Asia remained in a glacial-like cold condition prior to 8 kyr BP and experienced abrupt warming of &sim;9 &deg;C after the collapse of the Laurentide ice sheet. Comparison with pollen and other geochemical data indicates the abrupt warming is closely associated with major increase in the moisture supply to the region. Together, our multiproxy data indicate &sim;2 thousand years delay of temperature and moisture optimum relative to local summer insolation maximum, suggesting major influence of the Laurentide ice sheet and other high latitude ice sheet forcings on the regional atmospheric circulation. In addition, our data reveal a temperature drop by &sim;4 &deg;C around 4 kyr BP lasting multiple centuries, coinciding with severe increases in aridity previously reported based on multiproxy data. In contrast, model simulations display a much less pronounced delay in the initiation of Holocene warm conditions, raising unresolved questions about the relative importance of local radiative forcing and high-latitude ice on temperature in this region

High-efficiency electrocatalytic nitrite reduction toward ammonia synthesis on CoP@TiO2 nanoribbon array

Summary: Electrochemical reduction of nitrite (NO2−) can satisfy the necessity for NO2− contaminant removal and deliver a sustainable pathway for ammonia (NH3) generation. Its practical application yet requires highly efficient electrocatalysts to boost NH3 yield and Faradaic efficiency (FE). In this study, CoP nanoparticle-decorated TiO2 nanoribbon array on Ti plate (CoP@TiO2/TP) is verified as a high-efficiency electrocatalyst for the selective reduction of NO2− to NH3. When measured in 0.1 M NaOH with NO2−, the freestanding CoP@TiO2/TP electrode delivers a large NH3 yield of 849.57 μmol h−1 cm−2 and a high FE of 97.01% with good stability. Remarkably, the subsequently fabricated Zn–NO2− battery achieves a high power density of 1.24 mW cm−2 while delivering a NH3 yield of 714.40 μg h−1 cm−2

Fabrication of Hollow Mesoporous Copper Sulfide Nanocapsules Loaded with Natural Photoactivated Pesticides for Sustainable Plant Disease Management

Photoactivated pesticides (PPs) have photodynamic antimicrobial activities and show good environmental compatibility and slow resistance development. However, the disadvantages of easy aggregation, short duration, and low efficiency seriously restrict the efficient application of PPs. Hollow mesoporous copper sulfide nanoparticles (HMCuS NPs) with unique optical properties show photodynamic antimicrobial activity under light irradiation, which are considered smart drug delivery carriers due to their good water dispersivity and high drug encapsulation surface area. Herein, novel acid-responsive photoactivated pesticide nanocapsules (PPs@HMCuS-CTS NPs) were established by electrostatically coating HMCuS NPs loaded with PPs (curcumin and physcion) with chitosan (CTS). The results showed that the obtained nanocapsules had desirable water dispersivity (PDI0.25) and acid-responsive release properties. The antimicrobial activity of PPs@HMCuS-CTS NPs under light irradiation was more than 1.47 times those of PPs alone and the mixture of PPs and HMCuS NPs due to the synergistic photodynamic antimicrobial activity. Rainfastness, safety assessment, and genotoxicity evaluation demonstrated that the PPs@HMCuS-CTS NPs deposited more than 1.28 times PPs on plant foliage without any damage to the crop. Therefore, acid-responsive photoactivated pesticide nanocapsules based on HMCuS NPs have the potential to be an efficient and safe pesticide delivery system