57 research outputs found
Interfacial Adsorption and Structure on Graphene:Ion Adsorption, Air Bubbles, and Lipid Membranes
Perfil, hábitos e atitudes do consumidor do presunto de Chaves
Esta comunicação tem por objectivos traçar o perfil do consumidor do Presunto de Chaves; conhecer os seus hábitos, as suas preferĂŞncias e as suas atitudes; determinar o grau de influĂŞncia de caracterĂsticas, designadamente, pessoais, sociais, geográficas, econĂłmicas e contextuais, na decisĂŁo de compra deste produto e verificar a existĂŞncia de diferenças de atitudes e comportamentos entre grupos no que diz respeito ao consumo deste tipo de produto. Esta investigação apoia-se em dados primários obtidos atravĂ©s da aplicação de um questionário a 200 turistas e ou visitantes do concelho de Chaves no perĂodo de Julho a Outubro do ano de 2006
Detection of copy number variations and their effects in Chinese bulls
BACKGROUND: Copy number variations (CNVs) are a main source of genomic structural variations underlying animal evolution and production traits. Here, with one pure-blooded Angus bull as reference, we describe a genome-wide analysis of CNVs based on comparative genomic hybridization arrays in 29 Chinese domesticated bulls and examined their effects on gene expression and cattle growth traits. RESULTS: We identified 486 copy number variable regions (CNVRs), covering 2.45% of the bovine genome, in 24 taurine (Bos taurus), together with 161 ones in 2 yaks (Bos grunniens) and 163 ones in 3 buffaloes (Bubalus bubalis). Totally, we discovered 605 integrated CNVRs, with more “loss” events than both “gain” and “both” ones, and clearly clustered them into three cattle groups. Interestingly, we confirmed their uneven distributions across chromosomes, and the differences of mitochondrion DNA copy number (gain: taurine, loss: yak & buffalo). Furthermore, we confirmed approximately 41.8% (253/605) and 70.6% (427/605) CNVRs span cattle genes and quantitative trait loci (QTLs), respectively. Finally, we confirmed 6 CNVRs in 9 chosen ones by using quantitative PCR, and further demonstrated that CNVR22 had significantly negative effects on expression of PLA2G2D gene, and both CNVR22 and CNVR310 were associated with body measurements in Chinese cattle, suggesting their key effects on gene expression and cattle traits. CONCLUSIONS: The results advanced our understanding of CNV as an important genomic structural variation in taurine, yak and buffalo. This study provides a highly valuable resource for Chinese cattle’s evolution and breeding researches. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-480) contains supplementary material, which is available to authorized users
Advances in Strain Improvement for the Production of ε-Poly-L-lysine
ε-Poly-L-lysine (ε-PL) is a novel biopolymer consisting of 25–35 L-lysine residues, which is formed by the dehydration condensation of ε-NH2 and α-COOH. ε-PL possesses many excellent characteristics, such as antimicrobial activity, edibility, water solubility, biodegradability, thermostability and nontoxicity. As a natural and safe food preservative, ε-PL possesses many excellent advantages such as thermal stability, edibility, water solubility, degradability, and broad-spectrum antibacterial activity and has been successfully utilized in Japan, South Korea, the United States, China and other countries. ε-PL is usually produced by fermentation with Streptomyces albulus, and improving ε-PL-producing stains is crucial for enhancing ε-PL production and reducing costs. At present, researchers have obtained microbial strains capable of producing high levels of ε-PL by using physicochemical mutagenesis, ribosome engineering, genome shuffling, genetic engineering and other methods. This review introduces the mechanism of ε-PL biosynthesis and recent progress in strain improvement for the production of ε-PL, and gives an overview of the fermentation process of ε-PL. Finally, this review concludes with an outlook on future research directions. We hope that this review can help promote strain improvement for green biological manufacturing of ε-poly-L-lysine
Supported lipid bilayers with encapsulated quantum dots (QDs) via liposome fusion: Effect of QD size on bilayer formation and structure
Computational dissection of two-dimensional rectangular titanium mononitride TiN: Auxetics and promises for photocatalysis
Recently, two-dimensional (2D) transition-metal nitrides have triggered an enormous interest for their tunable mechanical, optoelectronic, and magnetic properties, significantly enriching the family of 2D materials. Here, by using a broad range of first-principles calculations, we report a systematic study of 2D rectangular materials of titanium mononitride (TiN), exhibiting high energetic and thermal stability due to in-plane d–p orbital hybridization and synergetic out-of-plane electronic delocalization. The rectangular TiN monolayer also possesses enhanced auxeticity and ferroelasticity with an alternating order of Possion’s Ratios, stemming from the competitive interactions of intra- and inter- Ti—N chains. Such TiN nanosystem is a n-type metallic conductor with specific tunable pseudogaps. Halogenation of TiN monolayer downshifts the Fermi level, achieving the optical energy gap up to 1.85 eV for TiNCl(Br) sheet. Overall, observed electronic features suggest that the two materials are potential photocatalysts for water splitting application. These results extend emerging phenomena in a rich family 2D transition-metal-based materials and hint for a new platform for the next-generation functional nanomaterials
Global crop-specific nitrogen fertilization dataset in 1961–2020
Abstract Nitrogen (N) is an important nutrient for crop growth. However, the overuse of N fertilizers has led to a series of devastating global environmental issues. Recent studies show that multiple datasets have been created for agricultural N fertilizer application with varied temporal or spatial resolutions, nevertheless, how to synchronize and use these datasets becomes problematic due to the inconsistent temporal coverages, spatial resolutions, and crop-specific allocations. Here we reconstructed a comprehensive dataset for crop-specific N fertilization at 5-arc-min resolution (~10 km by 10 km) during 1961–2020, including N application rate, types, and placements. The N fertilization data was segmented by 21 crop groups, 13 fertilizer types, and 2 fertilization placements. Comparison analysis showed that our dataset is aligned with previous estimates. Our spatiotemporal N fertilization dataset could be used for the land surface models to quantify the effects of agricultural N fertilization practices on food security, climate change, and environmental sustainability
An integrated economic-ecological index based on satellite-derived carbon sequestration and carbon price: A case study during 2015–2020 in Shaanxi, China
Carbon sequestration reflecting vegetation productivity is essential for global carbon cycle and terrestrial ecosystems. Exploring the spatial and temporal variation of carbon sequestration and corresponding ecological values yields insights for policy formulation to mitigate carbon emission and achieve carbon neutrality. Hence, taking Shaanxi China as the case study, we developed an integrated index (named C-GDP) based on vegetation carbon sequestration estimated by the CASA model and carbon prices acquired from carbon trading market in China to explore tradeoffs between economic and ecological development. The spatiotemporal distributions of carbon sequestration and C-GDP were characterized using hotspot analysis and variation coefficient during 2015–2020. The estimated carbon sequestrations were assessed with promising accuracy, depicting high values in the south and low values in the north, with provincial averages of 1761.37gC/m2a. Temporally, carbon sequestrations increased with fluctuation between 2015 and 2020, with significant seasonality. Summertime, especially July, has the highest sequestration, while winter is the season with the lowest values. The C-GDP calculated by carbon sequestration and carbon price exhibited a distinct pattern with sequestration, with the highest C-GDP in Central Shaanxi and the lowest in the south. The multi-year provincial-mean C-GDP is 20.44 billion yuan. The C-GDP exhibited an increase trend with miniscule fluctuation, peaking at 23.66 billion yuan in 2020. The results imply the ecological value of carbon sequestration monetizing by carbon prices is much lower than economical value of production, suggesting that strict carbon policies, such as improving carbon prices or taxes, may be warranted for China because of high carbon mitigation costs
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