Growth and physiological response of tall oat grass to salinity stress

In order to evaluate the responses of tall oat grass plants to increasing salinity, we measured plant growth, ion contents, photosynthetic gas exchange, lipid peroxidation, and proline accumulation in four salt concentrations. Two tall oatgrass genotypes, ZXY03P-367 and ZXY03P-443, were grown for 14 days in greenhouse conditions and after 14 days treated with four NaCl treatments (0, 65, 100, and 135 mM ) for 21 days. Most parameters for the two genotypes were significantly different when they were subjected to 100 and 135 mM NaCl. Salt treatment led to decreases in root and shoot biomass, photosynthetic rate (A) and stomatal conductance (gs), and K+ content, and a concurrent increase in Na+ content. Larger reductions in the parameters occurred in ZXY03P-443. A significant accumulation of lipid peroxidation and proline in leaves was found during the period of intensive leaf growth. These organic compounds likely played a role in leaf osmotic adjustment and in the protection of membrane stability at severe salinity levels. Our results indicated that the two tall oatgrass genotypes differ in their sensitivity to salinity, with ZXY03P-336 classified as relatively salt tolerant and ZXY03P-443 as  sensitive.Key words: Growth, physiological responses, salinity stress, tall oatgras

Effect of sex on meat quality characteristics of Qinchuan cattle

A total of 18 Qinchuan cattle, six intact males (IM), six castrated males (CM) and six females (FM), were used to investigate the effect of sex on the physicochemical characteristics (PCC) and fatty acid (FA) composition of the Longissimus dorsi muscle (LDM). Obvious sex differences were found in the PCC of LDM: the IM group had higher shear value, pH, drip and cooking losses, and contents of ash and hydroxyproline (Hyp) than the CM and FM groups, as well as lower ether extract content and lightness. Both the IM and CM groups had lower water content and higher protein content than the FM group. Sex differences were also observed in contents of C14:0, C14:1, C18:1, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and unsaturated fatty acids (UFA) between the IM and both the CM and FM groups but not between the CM and FM groups. The results indicated that sex is an importantsource of differences in meat quality of Qinchuan cattle because the castration and the meat characteristics of the CM group were more similar to the FM than the IM group

Using agronomic biofortification to boost zinc, selenium, and iodine concentrations of food crops grown on the loess plateau in China

Micronutrient malnutrition among humans is typically caused by micronutrient deficiency in soils and then staple food crops grown on these soils. In this study, field trials were conducted to investigate the biofortification of micronutrients in the edible parts of winter wheat, maize, soybean, potato, canola, and cabbage. Fertilizers of Se, Zn and I were applied to soil independently or together, while Se and Zn were sprayed as solution on winter wheat in another part of the trials. Selenium, when applied to the soil in the form of sodium selenate, whether alone or combined with Zn and⁄or I, was effective in increasing Se to around target levels in all of the tested crops. Selenium as sodium selenite was effective as a foliar application to winter wheat, increasing it from 25 to 312 µg kg⁻¹ in wheat grain with 60 g Se ha⁻¹ . For Zn, soil-applied zinc sulphate was only found to be effective for increasing the Zn concentration in cabbage leaf and canola seed, with 35 and 61 mg kg ⁻¹, respectively, while foliar zinc sulphate application was effective in biofortifying winter wheat, increasing grain Zn from 20 to 30 mg kg⁻¹ . While for I, soil-applied potassium iodate was only effective in increasing I concentration in cabbage leaf, and biofortification of the other crops was not possible. The enhancements of Se, Zn, and I concentration resulting from either the single or combined application of microelement fertilizers were similar. Therefore, agronomic biofortification of edible parts of various food crops with Zn, Se, and I can be an effective way to increase micronutrient concentrations, and the effectiveness depends on crop species, fertilizer forms and application methods.H. Mao, J. Wang, Z. Wang, Y. Zan, G. Lyons, C. Zo

Novel polymorphism of the bovine fat mass and obesity-associated (FTO) gene are related to backfat thickness and longissimus muscle area in five Chinese native cattle breeds

In this study, genetic variation of the fat mass and obesity-associated gene (FTO) was detected by PCRSSCP and DNA sequencing in 618 individuals from five Chinese indigenous cattle breeds, and their genetic effects on meat quality traits were evaluated. The results showed that a novel single nucleotide polymorphism C1071T was detected in exon 5 and the allelic frequencies for the C and T alleles of the five breeds were 0.666/0.334, 0.583/0.417, 0.631/0.369, 0.653/0.347 and 0.689/0.311, respectively. Animals with CT genotype had higher mean values for backfat thickness than those with CC or TT genotypes (P < 0.01). Individuals with CC or CT genotypes had higher longissimus muscle area than those with TT genotype (P < 0.05). The FTO gene may be a candidate gene for identifying differences in meat quality traits and therefore, could be applied to marker-assisted selection of native Chinese cattle breeds.Key words: Cattle, fat mass and obesity-associated (FTO) gene, single nucleotide polymorphism (SNP), meat quality traits

Evaluation of temperature distribution for bone drilling considering aging factor

Bone drilling is a routine operation in surgeries, such as neurosurgery and orthopedics. However, the excessive drilling temperature may cause severe thermal damage to the bone tissue. Therefore, the drilling temperature determination of bone tissue can reduce the harm caused by thermal damage. A time-varying temperature field simulation model of bone drilling was set up by ABAQUS software in this paper, based on the Johnson-Cook model. Then it was validated with experiments by drilling cortical bone of fresh bovine shaft of the femur. The relative error between the experimental values and the theoretical values within 7.67% showed a good consistency. Furthermore, the aging factor is also considered to evaluate the temperature field of bone drilling. The results showed that the drilling temperature near the bone-drill area increased significantly. The drilling temperature of cortical bone decreases sharply with the radial distance and exhibits a hysteresis lag in the axial distribution. The aging factor mainly affects the peak of drilling temperature. The peak of drilling temperature tends to increase with age. The peak drilling temperature in the elderly (70y) was up to 6.8% higher than that in the young (20y), indicating that the elderly is more prone to excessive drilling temperature. Therefore, special attention should be paid to the temperature control of elderly bone tissue

Optimization Matrix Factorization Recommendation Algorithm Based on Rating Centrality

Matrix factorization (MF) is extensively used to mine the user preference from explicit ratings in recommender systems. However, the reliability of explicit ratings is not always consistent, because many factors may affect the user's final evaluation on an item, including commercial advertising and a friend's recommendation. Therefore, mining the reliable ratings of user is critical to further improve the performance of the recommender system. In this work, we analyze the deviation degree of each rating in overall rating distribution of user and item, and propose the notion of user-based rating centrality and item-based rating centrality, respectively. Moreover, based on the rating centrality, we measure the reliability of each user rating and provide an optimized matrix factorization recommendation algorithm. Experimental results on two popular recommendation datasets reveal that our method gets better performance compared with other matrix factorization recommendation algorithms, especially on sparse datasets

Graphene re-knits its holes

Nano-holes, etched under an electron beam at room temperature in singlelayer graphene sheets as a result of their interaction with metalimpurities, are shown to heal spontaneously by filling up with either non-hexagon, graphene-like, or perfect hexagon 2D structures. Scanning transmission electron microscopy was employed to capture the healing process and study atom-by-atom the re-grown structure. A combination of these nano-scale etching and re-knitting processes could lead to new graphene tailoring approaches.Comment: 11 pages, 4 figure

The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots

During plant immunity, surface-localized pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs). The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs) EFR and XA21 from Arabidopsis thaliana (Arabidopsis) and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto) DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots

Gene conversion in human rearranged immunoglobulin genes

Over the past 20 years, many DNA sequences have been published suggesting that all or part of the V<sub>H</sub> segment of a rearranged immunoglobulin gene may be replaced in vivo. Two different mechanisms appear to be operating. One of these is very similar to primary V(D)J recombination, involving the RAG proteins acting upon recombination signal sequences, and this has recently been proven to occur. Other sequences, many of which show partial V<sub>H</sub> replacements with no addition of untemplated nucleotides at the V<sub>H</sub>–V<sub>H</sub> joint, have been proposed to occur by an unusual RAG-mediated recombination with the formation of hybrid (coding-to-signal) joints. These appear to occur in cells already undergoing somatic hypermutation in which, some authors are convinced, RAG genes are silenced. We recently proposed that the latter type of V<sub>H</sub> replacement might occur by homologous recombination initiated by the activity of AID (activation-induced cytidine deaminase), which is essential for somatic hypermutation and gene conversion. The latter has been observed in other species, but not in human Ig genes, so far. In this paper, we present a new analysis of sequences published as examples of the second type of rearrangement. This not only shows that AID recognition motifs occur in recombination regions but also that some sequences show replacement of central sections by a sequence from another gene, similar to gene conversion in the immunoglobulin genes of other species. These observations support the proposal that this type of rearrangement is likely to be AID-mediated rather than RAG-mediated and is consistent with gene conversion