基于地理探测器模型的川西北家畜空间分布差异影响因素分析

川西北放牧家畜分布具有空间尺度分异的特征,以乡镇为单位的基础数据,在研究自然和人为因素对家畜空间分布的影响方面,有助于得出更细致、更客观的结果,将为川西北地区畜群结构的优化提供科学依据.试验以气象、地形、植被类型、植被覆盖度、土地利用类型、人口、出栏管理等方面的数据为基础,利用GIS空间分析和地理探测器模型相结合的方法...     

The effect of astragaloside IV on JAK2‐STAT6 signalling pathway in mouse model of ovalbumin‐induced asthma

Asthma is a chronic inflammatory lung disease of the airway; the incidence and prevalence of asthma remain high worldwide. Astragaloside IV (AS‐IV) is the main active constituent of Astragalus membranaceus. Accumulating evidence suggests that AS‐IV possesses anti‐inflammatory and anti‐asthmatic ability, but the potential molecular mechanism is required to further clarify. In this study, the anti‐asthmatic effects of AS‐IV on mice with ovalbumin (OVA)‐induced allergic inflammation were analysed. We analysed airway hyperresponsiveness (AHR), numbers of inflammatory cells, inflammation situation in lung tissue and cytokines level in bronchoalveolar lavage fluid (BALF) between OVA‐induced mice with and without AS‐IV treatment. Moreover, we explored the possible signalling pathway behind the anti‐asthmatic effects. Our results revealed that AS‐IV treatment ameliorates airway inflammation and AHR in an OVA‐induced asthma model. Besides, AS‐IV treatment inhibits the interleukin (IL)‐4, ‐5 and ‐13 production, and further study indicated that AS‐IV treatment downregulates the expression level of p‐JAK2/p‐STAT6 proteins. Taken together, the present study suggested that the inhibitory effects of AS‐IV on asthma therapy are at least partially involved in inhibiting the JAK2/STAT6 signalling pathway.     

果蔬冷冻新技术的研究进展

概述了几种果蔬冷冻新技术,即高压冷冻、超声波联合冷冻、电磁场辅助冷冻(磁场辅助冷冻和脉冲电场冷冻处理),这些技术主要通过缩短冷冻时间(6%~24%)、形成较小的冰晶(直径≤80μm)以提升冷冻产品品质。高压冷冻形成冰晶具有瞬时性,能应用于体积较大的水果,但不适合质地过软的果蔬;超声波冷冻通过超声波空穴效应,形成更小的冰晶并能一定程度灭酶,缺点是冷冻过程需要包装以隔绝冷冻液;磁场辅助冷冻是最先应用于生产中(日本CAS冷冻设备),能缩短果蔬冷冻相变时间;脉冲电场冷冻虽能显著缩短冷冻时间,但易造成细胞膜穿孔,需要配合冷冻保护剂和组织改进剂。因此,应该根据果蔬体积、质地等因素选择合适的冷冻新技术,以提高果蔬冷冻品质。     

高寒区山生柳无性繁殖技术的灰色系统理论分析

针对山生柳3种不同无性繁殖技术,利用灰色系统关联度分析方法对其进行了计算分析,结果表明:无性繁殖技术观测指标间的关联度大小依次为:保存率主根长度茎粗株高一级分枝数量地上生物量鲜质量侧根数量;3种不同处理的关联度大小依次为:硬枝扦插嫩枝扦插根插。主根长度、茎粗和株高3个观测指标是影响山生柳无性繁殖成活率的主要指标因子,硬枝扦插处理是山生柳在高寒区最适合的快繁技术。     

若尔盖高寒退化湿地土壤碳氮磷比及相关性分析

以若尔盖花湖湿地保护区高寒草甸—高寒草原空间演替为研究对象,结合草地利用现状及微地形分布,遴选出5个高寒退化湿地类型进行鼠类洞穴密度和土壤碳、氮、磷含量的调查取样并进行相关性分析。结果表明,5个样地土壤表层(0～10 cm)碳、氮平均含量分布范围分别为3.7%～4.9%和0.38%～0.56%,样地间差异不显著(P＞0.05),磷元素含量由坡地区(样地Ⅰ、Ⅱ、Ⅲ)向平地区(样地Ⅳ、Ⅴ)呈递增趋势,差异性显著(P＜0.05);0~40 cm土壤碳氮比(C/N)为11.01,样地间差异不显著(P＞0.05),碳磷比(C/P)为 62.3、氮磷比(N/P) 为5.69,样地间均差异显著(P＜0.05);土壤碳、氮、磷含量及碳氮比、氮磷比均随土层加深呈降低趋势,其中有机碳含量减少4.36%,0～10 cm表层土壤碳氮比显著高于深层土壤(P＜0.05);鼠类洞穴密度与碳磷比、全磷具有极显著的正相关,而土层深度与所有碳、氮、磷化学计量特征都具有极显著的负相关性。研究结果将为鼠害防控及草地营养循环、碳源/汇转化机制、退化草地植被恢复、土壤养分管理提供理论依据。     

毛霉型豆豉的研究进展

毛霉型豆豉是我国传统的豆类发酵品,因其营养丰富、风味独特而深受消费者喜爱。通过综述毛霉型豆豉发酵工艺、微生物菌群研究,对其活性成分及保健功效进行阐述,并对安全性问题进行分析,对毛霉型豆豉今后的发展前景进行展望。     

黄河首曲-玛曲县次生裸地的类型、成因、特征及其生态修复模式

在前人研究和笔者实地踏查基础上,根据次生裸地形成主要驱动因子和景观特征不同,将玛曲县次生裸地分为沙化型次生裸地、"黑土滩"型次生裸地、盐碱化次生裸地、迁弃牧居点、废弃牧道、矿区和公路沿线等,对其成因和特征进行探讨,进而制定相应科学合理的生态修复模式,为该区域退化生态系统修复与重建提供理论依据和技术支撑。     

Altitudinal pattern of grazing exclusion effects on vegetation characteristics and soil properties in alpine grasslands on the central Tibetan Plateau

Journal of Soils and Sediments - Grazing exclusion by fencing has been widely used for restoring degraded alpine grasslands, but rarely studies have considered the altitudinal difference of grazing...