409 research outputs found
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Extending shelf-life of fresh-cut pears
Different concentrations of various browning inhibitors and a firming agent were evaluated to prevent browning and softening of Bartlett, Bosc and Anjou pear slices during cold storage at 2-4°C. Browning inhibition effect of Semperfresh, Snow Fresh and cysteine were compared with that of 4-hexylresorcinol (4-HR). The effect of ripeness on color and texture changes as well as the influence of storage temperature on texture and color retention was investigated. 4-HR residual content under different treatment conditions and its sensory properties were analyzed. 4-HR was an effective browning inhibitor at concentration as low as 0.005% when combined with 0.5% ascorbic acid (AA). Cysteine (0.5%) with 0.5% ascorbic acid (AA) effectively inhibited Anjou and Bosc pear slice browning for 25 days and its sensory properties merit further study. A combination of 1.0% AA and 1.0% calcium lactate prevented Anjou pear slices from discoloration, but also caused tissue leaking and softening. Semperfresh and Snow Fresh did not maintain flesh color effectively. 1.0% calcium lactate maintained slice firmness at an acceptable level for 30 days when the average firmness of whole pears at slicing was 49, 38 and 43 Newton (N) for Bartlett, Bosc and Anjou respectively. A storage temperature of 0°C significantly retained better texture than the control of 2-4°C. Slices with acceptable texture and color were achieved by treatment with a solution of 0.01% 4-HR, 0.5% AA, and 1.0% calcium lactate for 2 min, vacuum packaging, and storage at 2-4°C for 30 days for Bartlett and Bosc, and 15 days for Anjou. 4-HR residual content increased with increasing dipping times and concentrations, with the latter being the major factor. The 4-HR residual decreased with storage time for all the treatments. Sensory tests indicated that panelists detected the overall differences between 0.01% 4-HR treated samples and the controls for both Bartlett and Anjou pears (P<0.01). There were no significant differences in preference between treated sample and control for Anjou pears
Isolation of a novel abscisic acid stress ripening (OsASR) gene from rice and analysis of the response of this gene to abiotic stresses
Abiotic stresses constitute a serious threat to agricultural production, which often develops into major crop production reducing factors around the world. Molecular biology technology has, however, emerged as a promising vehicle improving crop tolerance. A cold-, drought- and heat-inducible gene designated Oryza sativa L. abscisic acid stress-ripening (OsASR) gene, GenBank accession: AK318549.1 was identified in rice Pei’ai64s (O. sativa L. ssp. Indica cv.) using the GeneChip rice genome array (Affymetrix) representing 51, 279 transcripts from two rice subspecies japonica and indica. The expression profile of OsASR obtained by the microarray analysis was confirmed by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) analysis of the gene. The two sets of data matched very well, suggesting that OsASR is a multiple stresses responsive gene in rice. Based on the sequence, PCR primers were designed. The cDNA with the whole open reading frame (ORF) was amplified by PCR and cloned. Sequence analysis showed that the cDNA encodes a protein of 284 amino acid residues with M.W. ≈ 11.7 kD and pI ≈ 10.4. The gene encodes a protein with several conserved domains. Comparison of protein sequences indicates that OsASR encodes a putative abscisic acid stress-ripening protein. Analysis of the putative promoter region for candidate cis-regulatory elements using PlantCARE software identified seven kinds of cis-elements related to stress responses. Based on the aforementioned analyses and results obtained, we propose that OsASR is a novel candidate gene involved in stress tolerance in rice.Keywords: Rice, microarray, abiotic stress, reverse transcription polymerase chain reaction (RT-PCR), abscisic acid stress ripenin
Community-based Message Opportunistic Transmission
Mobile Social Networks (MSNs) is a kind of opportunistic networks, which is composed of a large number of mobile nodes with social characteristic. Up to now, the prevalent communitybased routing algorithms mostly select the most optimal social characteristic node to forward messages. But they almost don\u27t consider the effect of community distribution on mobile nodes and the time-varying characteristic of network. These algorithms usually result in high consumption of network resources and low successful delivery ratio if they are used directly in mobile social networks. We build a time-varying community-based network model, and propose a community-aware message opportunistic transmission algorithm (CMOT) in this paper. For inter-community messages transmission, the CMOT chooses an optimal community path by comparing the community transmission probability. For intra-community in local community, messages are forwarded according to the encounter probability between nodes. The simulation results show that the CMOT improves the message successful delivery ratio and reduces network overhead obviously, compared with classical routing algorithms, such as PRoPHET, MaxProp, Spray and Wait, and CMTS
Cross-Cultural Contrastive Study of English and Chinese Euphemisms
The use of euphemisms is a common linguistic phenomenon in all languages. By using euphemisms, people can indirectly and politely express their ideas, without making the listeners feel awkward and unpleasant. As a mirror of culture, the generation and development of euphemisms are closely related to culture. Euphemisms in English and Chinese are also abundant, but they have both differences and similarities in expressions and cultural connotations. The cross-cultural contrastive study of English and Chinese euphemisms can help people correctly understand the deep meaning in English and Chinese languages and overcome the obstacles in cross-cultural communications.Key words: Euphemisms; Culture; Cross-culture; Contrastive stud
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