Heart rate variability parameters as markers of the adaptation to a sealed environment (a hypoxic normobaric chamber) in the horse

Simulated hypoxic normobaric devices have been used in human beings in order to enhance endurance capacity. These devices are sealed chambers where the athletes are supposed to stay for at least 6–8 hr daily. The current research assesses the changes in time‐domain, spectral and non‐geometrical heart rate variability (HRV) parameters in 6 horses subjected to progressive duration periods inside of a hermetically sealed chamber. It was pursued, firstly to evaluate the intensity of the stress experienced by the animals and secondly to elucidate whether the horses might require an acclimation period before implementation of hypoxic conditions. HRV parameters were monitored for 6 days: day 0 (6‐hr duration; in paddocks; basal conditions), and days 1, 2, 3, 4 and 5 (1, 2, 3, 4 and 6 hr inside the chamber every day respectively). During day 1 and during the first hours of days 2 and 3, compared to day 0, horses presented increased HR and SDHR values and decreased RR interval duration. SD1 values decreased on some hours of days 2 and 3, but differences with day 0 were not found on day 1. Increased SDNN, RMSSD, SD1 and SD2 values were observed on days 4 and 5. These results showed an activation of the sympathetic activity together with an attenuation of the parasympathetic activity during the days 1 to 3. Increased parasympathetic activity was found only during the first hours of days 4 and 5. Spectral parameters experienced minor variations, with increased LF_peak and LF% during some hours of days 4 and 5. In conclusion, at least 3 days are needed to adapt the horse to a sealed environment before starting to subject the animals to hypoxic conditions. When the horses were acclimatized, however, a minor stress was detected with they spent more than 4 hr inside of the chamber.     

不同稻秸添加比例对紫花苜蓿和麦麸混合青贮的影响

为探讨不同稻秸添加比例对紫花苜蓿和麦麸混合青贮发酵品质的影响,以紫花苜蓿、麦麸及5个不同比例(0、5%、10%、15%和20%)的稻秸分别进行混合裹包青贮,30 d后测定混合青贮饲料的发酵品质、营养品质和有氧稳定性。结果表明:1)稻秸添加组与不添加的对照组pH、可溶性碳水化合物(WSC)、酸性洗涤纤维(ADF)和NH_3-N/TN有显著差异(P<0.05);随着稻秸添加量的增加,pH值、ADF、中性洗涤纤维(NDF)和有氧稳定性递增,粗蛋白(CP)、WSC、相对饲料值(RFV)和V-Score值降低。2)根据V-Score评分可知,0和5%的稻秸添加组发酵品质为优,10%和15%稻秸添加组的发酵品质为良,20%稻秸添加组发酵品质中等。3)青贮30 d开包后,0和5%的稻秸添加组的有氧稳定性分别为64和72 h,10%、15%和20%稻秸添加组的有氧稳定性均大于168 h;有氧暴露4 d后,0、5%、10%和20%稻秸添加组pH值迅速变化,15%稻秸添加组变化相对较小。综上所述,优质混合青贮的推荐稻秸添加比例应小于5%。     

Lactobacillus parafarraginis ZH1 producing anti‐yeast substances to improve the aerobic stability of silage

Enhancing the aerobic stability of silage is very important in silage production. The objective of this study was to compare the roles of a new bacterial strain Lactobacillus parafarraginis ZH1 with Lactobacillus plantarum Chikuso‐1 (LP) and Lactobacillus buchneri NCIMB 40788 (LB) in improving the aerobic stability of oat silage and identify the anti‐yeast substances produced by them. After ensiled for 45 days, either inoculated silages or control silage were of pH values lower than 4.2. The control and LP inoculated silage had poorer aerobic stability than LB and ZH1 inoculated ones (p < 0.05). ZH1 inoculated silage produced more acetic acid, benzoic acid and hexadecanoic acid than LB inoculated one and had the best aerobic stability (p < 0.05). In MRS medium, strain ZH1 produced more hexadecanoic acid than LP and LB strains, more benzoic acid than strain LP (p < 0.05), and the equal amount of benzoic acid to LB (p > 0.05). In addition, benzoic acid and hexadecanoic acid had low minimal inhibitory concentrations to target yeasts in the pure culture. In conclusion, L. parafarraginis ZH1 had stronger anti‐yeast potential and more effectively improved the aerobic stability of silage than other strains used in this study.     

基于ORYZA2000模型的旱稻生长模拟及氮肥管理研究

以旱稻田间试验资料为基础,对水稻生长模拟模型ORYZA2000模拟旱稻生长进行参数校正和验证,图解和回归分析结果显示ORYZA2000模拟旱稻生物量、产量、作物吸氮量的模拟值与观测值基本呈线性关系,模拟效果良好,但对土壤水分的模拟效果欠佳,需做进一步研究。应用校正和验证的结果,结合肥料效应函数原理,对旱稻不同灌溉方式和密度管理下的氮肥经济最佳施肥量做了探讨,初步得出了该地区旱稻栽培氮肥经济最佳施肥量,丰富了作物模拟和节水农业的理论和实践,对以后旱稻发展及栽培管理有一定的参考价值。     

不同秸秆与城市污泥好氧堆肥过程中重金属质量分数及形态变化

以油菜、小麦、玉米和水稻秸秆为调理剂,与城市污泥混合进行好氧堆肥,研究了不同作物秸秆作调理剂对城市污泥好氧堆肥产品重金属质量分数及形态的影响.结果表明:好氧堆肥使堆体中Cd,Pb和Cr 3种重金属质量分数升高,使Pb,Cr可交换态质量分数及生物有效性降低,但不能降低Cd的生物有效性.其中,添加玉米秸秆有利于Cd的碳酸盐结合态向残渣态转化;添加油菜和水稻秸秆促进Cr分别向有机结合态和残渣态转化;添加玉米秸秆能有效降低Pb碳酸盐结合态质量分数,而水稻秸秆更有利于Pb向残渣态转化.表明4种秸秆作为调理剂对重金属形态的影响有一定的差异,对不同的重金属钝化效果不同,应根据污泥中的重金属选择合适的调理剂.     

蔬菜育苗中低温锻炼的作用与效果研究进展

摘要：为挖掘和创制蔬菜耐低温资源,促进蔬菜产业发展,综述了低温锻炼对蔬菜形态特征、细胞超微结构、膜脂过氧化、渗透调节物质（可溶性糖和脯氨酸）、保护酶的影响的研究进展,发现可以在幼苗移栽前通过低温锻炼的方法提高植株生长势,增加可溶性糖、脯氨酸等渗透调节物质含量,增强SOD（超氧化物歧化酶）、POD（过氧化物酶）、CAT（过氧化氢酶）等保护酶活性,增强植株的耐寒能力。未来,建议加强高适宜“低温锻炼”蔬菜种质资源筛选,并深入研究蔬菜“低温锻炼”分子调控机制。     

城市住宅小区人居环境设计中老年视角的缺乏性

文章以台州海棠新村、迎春小区、欣宜家园3个住宅小区为例,运用实地勘察、问卷调查、数据分析等研究手段,调查老年人的活动内容和活动需求,探究现阶段住宅小区户外空间中老年人活动场所的建设状况,提出营造适宜老年人的户外活动场所的对策。       

添加麦秸对鸡粪堆肥过程中氮素减排及细菌群落的影响

好氧堆肥是实现鸡粪资源化利用最主要的技术手段,然而在堆肥过程中氮素损失较为严重,既降低肥效又引起严重的污染。本文以纯鸡粪堆肥为对照,利用麦秸将鸡粪堆肥的C/N调节至15,分析了堆肥过程材料中理化性质、氮素转化和微生物群落变化,探讨了减少堆肥氮素损失的技术与机理。结果显示,加入麦秸后堆肥高温持续时间达到23 d,比对照延长了9 d,pH较对照组明显降低,氮素损失降低了39.67%。硝态氮含量达到281.99 mg·kg^-1,比对照增加了68.75%。微生物群落趋于稳定,具有硝化功能的细菌o＿＿Staphylococcales、o＿＿Brachybacterium、f＿＿Staphylococcaceae、g＿＿Staphylococcus、g＿＿Salinicoccus相对丰度比对照分别增加了88.45%、96.39%、88.45%、96.08%、79.20%,有利于堆体氮素保留和转化。试验结果表明,加入麦秸秆之后影响了鸡粪堆肥的细菌群落结构,增加了具有硝化功能的细菌丰度,从而减少了堆体氮素的损失。     

智能型规模化膜覆盖好氧堆肥系统设计与试验

设计了一种适用于规模化生产的节能环保智能型膜覆盖好氧堆肥系统,主要包括总控系统、风控系统、传感系统和覆膜系统。结合上述各系统的功能性需求,进行了系统整体性设计、功能模块独立设计选型,该系统可实现堆肥关键参数的高精度实时监测、通风供氧的灵活智能反馈控制、多设备无线通讯等功能。利用该系统进行规模化膜覆盖好氧堆肥性能试验,研究结果表明:整个堆肥过程高温时段满足粪便无害化处理需求,堆体氧浓度维持在适宜水平,覆膜工艺下可确保堆体发酵状况良好。从所监测的流量、频率、温度、压力、氧浓度等多元参数和总体性能来看,与传统技术模式相比,该系统智能化程度显著提升,生产能耗和气体产排显著降低。     

典型畜禽粪便配伍食用菌菌渣堆肥研究

[目的]研究三种典型畜禽粪便工厂化高温好氧堆肥过程中物理化学参数的动态变化规律,为典型禽畜粪便和食用菌菌渣废弃物有机肥料化提供理论依据。[方法]本研究分别以新鲜牛粪、猪粪和鸡粪配以2倍质量(DW)的食用菌菌渣进行堆肥试验,研究了堆肥过程中温度、pH值、铵态氮、硝态氮和发芽指数等理化指标的动态变化规律。[结果]堆肥过程中牛粪、鸡粪和猪粪处理在55 ℃以上的持续时间均超过15 天,堆体温度均超过70 ℃。堆肥结束时,猪粪、鸡粪、牛粪处理的pH值分别为7.59、7.81、7.48,符合腐熟堆肥pH值在 5.5 ~ 8.5的一般标准,种子发芽指数(GI)均大于80%,总养分(N+P2O5+K2O)分别为4.31%、5.01%、4.57%,只有鸡粪处理满足有机肥养分标准(NY525-2012)。堆肥过程中各处理铵态氮含量逐渐下降,硝态氮含量逐渐增加,至堆肥结束时牛粪、鸡粪和猪粪处理铵态氮的减少量分别为45.6%、29.2%、33.9%,而相应地硝态氮含量分别增加到2.59 g kg-1、2.57 g kg-1、2.15 g kg-1。[结论]本研究结果可为适度规模养殖场的畜禽粪便进行堆肥处理提供一定的理论依据。