Change of Behavior of \u3cem\u3eBos grunniens\u3c/em\u3e in the Alpine Rangeland in the Eastern Tibetan Plateau

Over 6 million yaks (Bos grunniens) are grazed in the alpine rangelands of the eastern Tibetan Plateau in Qinghai Province, China. Degradation of rangelands has been caused by increased numbers of domestic animals following the rise of the human population. In our previous study in northern and southern sites of Tibetan Plateau in Qinghai Province from 2003 to 2006, behavior of yaks and chemical composition of the faeces (Hasegawa et al. 2006; Hasegawa et al. 2008) and vegetation (Li et al. 2006; Song et al. 2006) were investigated and compared between the two sites, and it was suggested that the material circulation was lower and deterioration of rangeland was greater in the former than in the latter. In this study, behavioral observations of yaks in alpine rangeland of Yushu National Ranch from 2004 to 2012 were carried out to estimate the change of rangeland condition in the southern site of Tibetan Plateau

Evolutionarily missing and conserved tRNA genes in human and avian

Viral infection heavily relies on host transfer RNA (tRNA) for viral RNA decoding. Counterintuitively, not all tRNA species based on anticodon are matched to all 64-triplet codons during evolution. Life solves this problem by cognate tRNA species via wobbling decoding. We found that 14 out of 64 tRNA genes in humans and the main avian species (chicken and duck) were parallelly missing, including 8 tRNA-A34NN and 6 tRNA-G34NN species. By analyzing the conservation of key motifs in tRNA genes, we found that box A and B served as intragenic tRNA promoters were evolutionally conserved among human, chicken, and duck. Thus, decoding viral RNA by similar wobbling strategies and tRNA transcripts may be

Errors in translational decoding: tRNA wobbling or misincorporation?

As the central dogma of molecular biology, genetic information flows from DNA through transcription into RNA followed by translation of the message into protein by transfer RNAs (tRNAs). However, mRNA translation is not always perfect, and errors in the amino acid composition may occur. Mistranslation is generally well tolerated, but once it reaches superphysiological levels, it can give rise to a plethora of diseases. The key causes of mistranslation are errors in translational decoding of the codons in mRNA. Such errors mainly derive from tRNA misdecoding and misacylation, especially when certain codon-paired tRNA species are missing. Substantial progress has recently been made with respect to the mechanistic basis of erroneous mRNA decoding as well as the resulting consequences for physiology and pathology. Here, we aim to review this progress with emphasis on viral evolution and cancer development

Spin polarization asymmetry at the surface of chromia

We demonstrate boundary spin polarization at the surface of a Cr2O3 single crystal using spin-polarized low-energy electron microscopy (SPLEEM), complementing prior spin polarized photoemission, spin polarized inverse photoemission, and x-ray magnetic circular dichroism photoemission electron microscopy measurements. This work shows that placing a Cr2O3 single crystal into a single domain state will result in net Cr2O3 spin polarization at the boundary, even in the presence of a gold overlayer. There are indications that the SPLEEM contrast for the two polarization states may be different, consistent with scanning tunneling microscopy spectroscopy results obtained from ultrathin films of Cr2O3

Determination of 55 Veterinary Antibiotics in Chicken Manure Using Ultra-High-Performance Liquid Chromatography – Tandem Mass Spectrometry (UPLC-MS/MS)

A highly efficient method for the detection and quantification of 55 veterinary antibiotics (VAs) in chicken manure belonging to six drug classes using solid-phase extraction (SPE) and ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed. The mixture of EDTA–McIlvaine buffer (pH 3.0) and the organic extractant (methanol–acetonitrile, 1:3, v/v) was used to isolate the target VAs from freeze-dried chicken manure. The extract was purified by a hydrophile–lipophile balance cartridge. All antibiotics showed excellent linear relationships in the range between 1 and 100 µg/kg with the coefficients of determination of the standard curves above 0.990. The recoveries of antibiotics were between 35.66% and 103.54% using matrix-matched calibration for quantification. The limits of detection and quantification were from 0.01 to 1.59 µg/kg and 0.04 to 4.76 µg/kg, respectively. The method was demployed to determine VAs in chicken manure from 12 farms, revealing contamination in all samples. A total of 13 VAs belonging to six classes were detected with concentrations up to 41.47 mg/kg. The presence of high concentrations of antibiotic residues in poultry manure poses a potential risk for environmental contamination. This work has identified significant differences in the types of VAs compared to literature reports. Additionally, it detected pleuromutilin antibiotics in chicken manure for the first time.</p

A Metal-Bridged Tricyclic Aromatic System: Synthesis of Osmium Polycyclic Aromatic Complexes

973 Program [2012CB821600]; NSFC [21332002, 21102120]; program for Changjiang Scholars and Innovative Research Team in UniversityAromaticity is one of the most important concepts in organic chemistry. A variety of metalla-aromatic compounds have been recently prepared and in most of those examples, the metal participates only in a monocyclic ring. In contrast, metal-bridged bicyclic aromatic molecules, in which a metal is shared between two aromatic rings, have been less developed. Herein, we report the first metal-bridged tricyclic aromatic system, in which the metal center is shared by three aromatic five-membered rings. These metalla-aromatics are formed by reaction between osmapentalyne and arene nucleophiles. Experimental results and theoretical calculations reveal that the three five-membered rings around the osmium center are aromatic. In addition, the broad absorption bands in the UV/Vis absorption spectra of these novel aromatic systems cover almost the entire visible region. This straightforward synthetic strategy may be extended to the synthesis of other metal-bridged polycyclic aromatics

Activation of PGC-1α-dependent mitochondrial biogenesis supports therapeutic effects of silibinin against type I diabetic periodontitis

Aim: To investigate whether silibinin impacts diabetic periodontitis (DP) via mitochondrial regulation. Materials and Methods: In vivo, rats were divided into control, diabetes, DP and DP combined with silibinin groups. Diabetes and periodontitis were induced by streptozocin and silk ligation, respectively. Bone turnover was evaluated by microcomputed tomography, histology and immunohistochemistry. In vitro, human periodontal ligament cells (hPDLCs) were exposed to hydrogen peroxide (H2O2) with or without silibinin. Osteogenic function was analysed by Alizarin Red and alkaline phosphatase staining. Mitochondrial function and biogenesis were investigated by mitochondrial imaging assays and quantitative polymerase chain reaction. Activator and lentivirus-mediated knockdown of peroxisome proliferator-activated receptor gamma-coactivator 1-alpha (PGC-1α), a critical regulator of mitochondria biogenesis, was used to explore the mitochondrial mechanisms. Results: Silibinin attenuated periodontal destruction and mitochondrial dysfunction and enhanced mitochondrial biogenesis and PGC-1α expression in rats with DP. Meanwhile, silibinin promoted cell proliferation, osteogenesis and mitochondrial biogenesis and increased the PGC-1α level in hPDLCs exposed to H2O2. Silibinin also protected PGC-1α from proteolysis in hPDLCs. Furthermore, both silibinin and activator of PGC-1α ameliorated cellular injury and mitochondrial abnormalities in hPDLCs, while knockdown of PGC-1α abolished the beneficial effect of silibinin. Conclusions: Silibinin attenuated DP through the promotion of PGC-1α-dependent mitochondrial biogenesis