Study of wavelet denoising in apple's charge-coupled device near-infrared spectroscopy

Discrete wavelet transform was used to eliminate the noise in the charge-coupled device near-infrared (CCD-NIR) spectra of apple. The influence of three parameters (wavelet function, decomposition level, and threshold) on the predictive ability of the calibration model was investigated. The result showed that the db, sym, and bior wavelet families performed well, while the coif, dmey, and haar wavelets were not able to denoise effectively. The best decomposition level was 2. The threshold selection rules of the default, Birge-Massart, and Penalty had good denoising results, while SURE, Sqtwolog, Heuristic SURE, and Minimax set all detailed coefficients to zero due to their high threshold values. The best denoising result was obtained with the combination of the bior3.3 wavelet function, two levels of decomposition, default threshold selection rule, and the soft thresholding method. The optimal model of soluble solids content was constructed. The relative standard deviation of prediction decreased from 7.79 to 5.82% after wavelet denoising.     

Binding of 2-nonanone and milk proteins in aqueous model systems

Interactions of the model flavor compound 2-nonanone with individual milk proteins, whey protein isolate (WPI), and sodium caseinate in aqueous solutions were investigated. A method to quantify the free 2-nonanone was developed using headspace solid-phase microextraction followed by gas chromatography with flame ionization detection. Binding constants (K) and numbers of binding sites (n) for 2-nonanone on the individual proteins were calculated. The 2-nonanone binding capacities decreased in the order bovine serum albumin > beta-lactoglobulin > alpha-lactalbumin > alpha s1-casein > beta-casein, and the binding to WPI was stronger than the binding to sodium caseinate. All proteins appeared to have one binding site for 2-nonanone per molecule of protein at the flavor concentrations investigated, except for bovine serum albumin, which possessed two classes of binding sites. The binding mechanism is believed to involve predominantly hydrophobic interactions.     

Effect of dietary daidzein on egg production, shell quality, and gene expression of ER-alpha, GH-R, and IGF-IR in shell glands of laying hens

Our previous studies demonstrated that dietary daidzein improves egg production in ducks during the late period of the laying cycle. The present study was aimed to investigate the effect of daidzein in laying hens, with more focus on eggshell quality. The expression of ER-alpha, GH-R, and IGF-IR mRNA in shell glands was determined to identify the target genes of daidzein action and to reveal the relationship between shell quality and profiles of gene expression in shell glands of laying hens. 1000 ISA hens, at 445 days of age, were allotted at random to two groups and given the basal diet with or without 10 mg of daidzein per kg diet for 9 weeks. Daidzein supplement significantly increased the egg laying rate and the feed conversion ratio. The eggshell thickness increased, while the percentage of cracked eggs decreased in daidzein-treated hens. Serum E2 and phosphate concentrations were not altered, but the level of serum Ca2+ and the tibia bone mineral density were significantly increased in the daidzein-treated group compared with their control counterparts. In parallel with the significant increase of oviduct weight, significant down-regulation of GH-R and IGF-IR mRNA and a trend of decrease in ERalpha mRNA expression in shell glands were observed in daidzein-treated hens. The results indicate that dietary daidzein improves egg laying performance and eggshell quality during the late (postpeak) laying stage of hens, which is associated with modulations in gene expression in the shell gland.     

Inter- and intraspecific variations of cadmium accumulation of 13 leafy vegetable species in a greenhouse experiment

Leafy vegetables are among the crop species that are most vulnerable to heavy metal pollution. This study investigated inter- and intraspecific variations of cadmium accumulation in 13 species with a total of 39 cultivars of leafy vegetables under two levels of soil Cd stress (1.5 and 7.7 mg kg (-1)). Intraspecific variations of shoot biomass and Cd concentration of the tested leafy vegetables were significantly larger than interspecific variations under both Cd treatments and were also more significantly correlated between two Cd stress levels when grouped by cultivar than grouped by species. These results indicate that cultivar is a more reliable taxa level for screening pollutant-safe leafy vegetables than species. Any screening for pollutant hypoaccumulator species, or other similar species-based concepts, without considering intraspecific variation should be avoided.     

黄土半干旱区油松苗木蒸腾特性与影响因子的关系

 为分析土壤水分与气象因子对油松蒸腾作用的影响程度,提高造林成活率,并为林地水分管理提供科学依据。在2004年生长季典型晴天,采用盆栽试验,人为控制土壤水分,利用针叶Li-1600稳态气孔仪和BP-3400精密天平等仪器,对黄土半干旱区油松苗木的蒸腾特性及其影响因子的关系进行研究。结果表明:在不同的土壤水分条件下,油松蒸腾速率和气孔阻力的日变化曲线分别呈“双峰型”和“W”型;在典型晴天下,蒸腾速率与土壤含水量的关系呈三次曲线相关,7、8和10月份,油松叶片蒸腾速率达到最大值时所对应的土壤含水量分别为17.7%、19.8%和17.5%。蒸腾速率除自身生理特性的影响外,还受土壤水分和气象因子综合影响,当土壤水分充足时,蒸腾速率与气象因子相关性高;当土壤水分产生胁迫时,蒸腾速率与气象因子相关性降低。在严重土壤水分胁迫下,7和8月份气温对蒸腾作用的影响最大,10月份光合有效辐射的影响最大。在土壤充分供水的条件下,7月份空气相对湿度对蒸腾作用的影响最大,8月份是气温,10月份是叶温。     

Peptides isolated from in vitro digests of milk enhance iron uptake by caco-2 cells

Milk proteins, during digestion, produce a range of biologically active peptides. Among those are peptides that may enhance iron absorption. The objective of this project was to investigate the effect of isolated milk peptides on iron uptake. Cow's milk, 0% fat, was subjected to a modified in vitro digestion process. The milk digest was further fractionated by gel filtration. All eluted fractions as well as beta-casein synthetic peptides (a tripeptide and a hexapeptide) were subsequently tested for effects on iron uptake with Caco-2 cell monolayers. Fractions of milk digests obtained through Sephadex G-25 gel filtration had a significant enhancing effect on iron uptake in Caco-2 cells compared to nonfractionated milk digests. Two fractions (P = 0) and the hexapeptide (P < 0.0001) enhanced iron uptake by up to 3-fold, whereas others and the tripeptide had no effect. These results suggest that selected peptides produced during the in vitro digestion of milk may enhance iron absorption; however, it remains to be demonstrated whether this effect may be nutritionally significant.     

Flumorph Is a Novel Fungicide That Disrupts Microfilament Organization in Phytophthora melonis

ABSTRACT The mechanism of the effects of flumorph (a novel fungicide) was investigated by analyzing alterations of hyphal morphology, cell wall deposition patterns, F-actin organization, and other organelles in Phytophthora melonis. Calcofluor white staining suggested that flumorph did not inhibit the synthesis of cell wall materials, but disturbed the polar deposition of newly synthesized cell wall materials during cystospore germination and hyphal growth. After exposure to flumorph, zoospores were able to switch into cystospores accompanied with the formation of a cell wall, whereas cystospores failed to induce the isotropic-polar switch and did not produce germ tubes but continued the isotropic growth phase. In flumorph-treated hyphae, the most characteristic change was the development of periodic swelling ("beaded" morphology) and the disruption of tip growth. Newly synthesized cell wall materials were deposited uniformly throughout the diffuse expanded region of hyphae, in contrast to their normal polarized patterns of deposition. These alterations were the result of F-actin disruption, identified with the fluorescein isothiocynate (FITC)-phalloidin staining. The disruption of F-actin also was accompanied by disorganized organelles: each swelling of subapical hyphae was associated with a nucleus. Vesicles did not undergo polarized secretion to the apical hyphae, but diffused around nuclei for the subapical growth; thus, the cell wall was thickened with periodic expansion along the hyphae. Upon removing flumorph, normal tip growth and organized F-actin were observed again. These data, as well as data published earlier, suggest that flumorph may be involved in the impairment of cell polar growth through directly or indirectly disrupting the organization of F-actin. The primary site of action by flumorph in the disruption of the F-actin organization is under investigation.     

生态保护红线政策演进过程及其对生态产品价值实现的作用机理——以东北国有林区为例

划定生态保护红线是践行"两山"理念的时代任务与优先行动,推动生态产品价值实现则是新时代中国特色社会主义生态文明建设与"后脱贫时代"共同富裕协同推进的重要举措。文中首先在解释生态保护红线内涵的基础上,梳理东北国有林区生态保护红线政策的演进脉络,并以黑龙江省为例结合实际情况理清生态保护红线政策对林业产业发展的约束范围及程度;其次分别针对不同类型的生态产业,阐述生态保护红线对于生态产品价值实现的作用机理;最后从3个方面提出在生态保护红线政策下促进生态产品价值实现的建议:以森林资源为纽带,紧密联系森林碳汇建设与碳中和战略目标;建立物质类生态产品科技创新联盟,增强市场化支撑能力;打造东北国有林区森林生态综合体,促进文化服务类生态产品价值实现。研究可为东北国有林区未来促进生态产品价值实现提供参考,以促进林木资源保护和林业经济高质量发展。     

贮藏温度和种子含水率对水曲柳种子活力指标的影响

为探明解除休眠水曲柳(Fraxinus mandshurica)种子适宜的贮藏条件,以解除休眠的水曲柳种子为材料,经室温自然阴干至不同含水率(低含水率7%、中等含水率10%和高含水率14%),分析种子不同含水率和不同温度(25℃、5℃、-20℃)干燥贮藏后的萌发表现。结果表明：种子含水率、贮藏温度以及两者交互作用均对干燥贮藏后水曲柳种子的发芽率、发芽指数、发芽时间影响极显著(P<0.01);室温贮藏条件下,种子含水率越高,水曲柳种子发芽率越低;低温(-20℃、5℃)贮藏条件下,高含水率种子仍然可以保持很高的发芽率。因此,生产实践中,低温贮藏种子的含水率控制在7%～14%,室温条件下贮藏种子含水率控制在7%。若短期贮藏水曲柳种子可以选择5℃条件贮藏,长期贮藏水曲柳种子选择-20℃较适宜。     

Can larch-Aralia elata agroforestry systems improve the soil chemical and microbial properties of larch plantations?

Agroforestry Systems - The conversion of secondary forests to larch plantations has resulted in soil degradation in Northeast China. Previous studies have proven that introducing native broadleaved...