典型喀斯特山区农业生物质能潜力估算——以贵州省为例

喀斯特山区生态环境脆弱,能源利用模式低值粗放,开展该区域的农业可利用生物质能潜力研究,对喀斯特山区农村能源建设和生态环境保护具有重要意义。以贵州省为例,在考虑土壤生态保留前提下,利用草谷比、土壤生态保留系数、收集系数、折标系数、副产物系数估算农村地区可利用农业生物质能资源总量。结果表明:(1) 2009—2015年间,贵州省年均可利用生物质能资源量达5191.50×10~4t标准煤,地均和人均农业生物质能资源量分别达到295 t标准煤/km~2和1.48 t标准煤/人,其中年均可能源化利用的达到1974.05×10~4t标准煤,占贵州省同期能源消费总量的21.84%。(2)贵州省生物质能储量结构比例分布不均,畜禽粪便资源利用潜力巨大,贡献值高达85%;其中,牛粪资源蕴藏量达年均3009.78×10~4t标准煤,贡献值达到68.39%,是贵州省最重要的农业生物质能资源。(3)从时序变化特征看,2009—2015年间贵州省生物质能资源量呈现U形结构,2011年达到最低值,这与2010年的西南大旱重要事件耦合。最后,针对贵州省农业生物质能现状,论文提出喀斯特山区应该合理布局秸秆电厂和秸秆固化成型燃料生产企业,提高畜禽的规模化养殖水平并加强农业生产防灾减灾工作,农村生活能源推广以沼气、节柴灶与节能秸秆气化炉高效利用相结合的能源利用结构等建议。     

Pulsed Electromagnetic Fields Improve Bone Microstructure and Strength in Ovariectomized Rats through a Wnt/Lrp5/β-Catenin Signaling-Associated Mechanism

Growing evidence has demonstrated that pulsed electromagnetic field (PEMF), as an alternative noninvasive method, could promote remarkable in vivo and in vitro osteogenesis. However, the exact mechanism of PEMF on osteopenia/osteoporosis is still poorly understood, which further limits the extensive clinical application of PEMF. In the present study, the efficiency of PEMF on osteoporotic bone microarchitecture and bone quality together with its associated signaling pathway mechanisms was systematically investigated in ovariectomized (OVX) rats. Thirty rats were equally assigned to the Control, OVX and OVX+PEMF groups. The OVX+PEMF group was subjected to daily 8-hour PEMF exposure with 15 Hz, 2.4 mT (peak value). After 10 weeks, the OVX+PEMF group exhibited significantly improved bone mass and bone architecture, evidenced by increased BMD, Tb.N, Tb.Th and BV/TV, and suppressed Tb.Sp and SMI levels in the MicroCT analysis. Three-point bending test suggests that PEMF attenuated the biomechanical strength deterioration of the OVX rat femora, evidenced by increased maximum load and elastic modulus. RT-PCR analysis demonstrated that PEMF exposure significantly promoted the overall gene expressions of Wnt1, LRP5 and β-catenin in the canonical Wnt signaling, but did not exhibit obvious impact on either RANKL or RANK gene expressions. Together, our present findings highlight that PEMF attenuated OVX-induced deterioration of bone microarchitecture and strength in rats by promoting the activation of Wnt/LRP5/β-catenin signaling rather than by inhibiting RANKL-RANK signaling. This study enriches our basic knowledge to the osteogenetic activity of PEMF, and may lead to more efficient and scientific clinical application of PEMF in inhibiting osteopenia/osteoporosis.     

LprG-Mediated Surface Expression of Lipoarabinomannan Is Essential for Virulence of Mycobacterium tuberculosis

Mycobacterium tuberculosis employs various virulence strategies to subvert host immune responses in order to persist and cause disease. Interaction of M. tuberculosis with mannose receptor on macrophages via surface-exposed lipoarabinomannan (LAM) is believed to be critical for cell entry, inhibition of phagosome-lysosome fusion, and intracellular survival, but in vivo evidence is lacking. LprG, a cell envelope lipoprotein that is essential for virulence of M. tuberculosis, has been shown to bind to the acyl groups of lipoglycans but the role of LprG in LAM biosynthesis and localization remains unknown. Using an M. tuberculosis lprG mutant, we show that LprG is essential for normal surface expression of LAM and virulence of M. tuberculosis attributed to LAM. The lprG mutant had a normal quantity of LAM in the cell envelope, but its surface was altered and showed reduced expression of surface-exposed LAM. Functionally, the lprG mutant was defective for macrophage entry and inhibition of phagosome-lysosome fusion, was attenuated in macrophages, and was killed in the mouse lung with the onset of adaptive immunity. This study identifies the role of LprG in surface-exposed LAM expression and provides in vivo evidence for the essential role surface LAM plays in M. tuberculosis virulence. Findings have translational implications for therapy and vaccine development.     

典型喀斯特区生态与贫困耦合特征分析——以贵州省9000个省级贫困村为例

生态环境与贫困具有较强的空间耦合性,深入研究二者耦合互动机制对喀斯特地区生态修复和精准扶贫具有重要意义。以代表中国南方喀斯特中心的贵州高原为研究对象,构建多维贫困与生态脆弱性指标体系,利用综合耦合协调度模型与热点分析法,剖析贵州9000个省级贫困村生态环境与贫困的耦合关系,并进行贫困村类型划分。研究结果表明：在空间上,贵州南部、北部和西北部多维贫困指数高,而生态环境脆弱指数整体呈西高东低的态势,二者空间分布格局存在明显差异,只存在点状重叠。贵州贫困村生态环境与贫困耦合度介于0.29-0.56之间,以微度、轻度耦合为主。从村域尺度看,生态环境对贫困村致贫原因的贡献不高,只占9.5%左右,贵州省69.3%的贫困村属于生态良好-一般贫困型,贵州在扶贫开发中应根据贫困村生态与贫困的耦合关系,加强东部贫困村的经济开发,强化西部贫困村的生态修复。     

世界自然遗产地陆生藻类物种多样性比较研究

藻类是真核生物进化、植物起源与进化、生物地理学研究的良好材料,研究藻类物种多样性对理解生命起源与早期进化,探明地球地质地貌演化有着非常重要的意义。以两世界自然遗产地施秉云台山白云岩喀斯特、赤水丹霞的陆生藻类为研究对象,通过G-F多样性指数、Jaccard相似性系数、Bray-Curtis矩阵比较分析了不同地质地貌的两世界自然遗产地陆生藻类的物种多样性及种组特征,结果如下：（1）两地陆生藻类丰富,均以蓝藻为优势,共有优势科为色球藻科Chroococcaceae、颤藻科Oscillatoriaceae,施秉云台山还具伪枝藻科Scytonemataceae、念珠藻科Nostocaceae优势,优势属为粘球藻属Gloeocapsa、色球藻属Chroococcus,赤水丹霞仅以粘球藻属Gloeocapsa为优势。（2）施秉云台山G-F多样性指数高于赤水丹霞。（3）两地陆生藻类泛热带成分明显,施秉云台山中国特有成分较赤水丹霞丰富;两地科、属、种相似性系数依次为：56.25%、44.05%、37.62%,科的相似性达到中度水平,与同纬度范围其它地区的Bray-Curtis矩阵聚类结果显示不同地质地貌的两地首先聚为一类。从陆生藻类多样性组成上,初步反映两世界自然遗产地的地质历史、地层岩性及地理位置的异同。     

Moderate-Intensity Rotating Magnetic Fields Do Not Affect Bone Quality and Bone Remodeling in Hindlimb Suspended Rats

Abundant evidence has substantiated the positive effects of pulsed electromagnetic fields (PEMF) and static magnetic fields (SMF) on inhibiting osteopenia and promoting fracture healing. However, the osteogenic potential of rotating magnetic fields (RMF), another common electromagnetic application modality, remains poorly characterized thus far, although numerous commercial RMF treatment devices have been available on the market. Herein the impacts of RMF on osteoporotic bone microarchitecture, bone strength and bone metabolism were systematically investigated in hindlimb-unloaded (HU) rats. Thirty two 3-month-old male Sprague-Dawley rats were randomly assigned to the Control (n = 10), HU (n = 10) and HU with RMF exposure (HU+RMF, n = 12) groups. Rats in the HU+RMF group were subjected to daily 2-hour exposure to moderate-intensity RMF (ranging from 0.60 T to 0.38 T) at 7 Hz for 4 weeks. HU caused significant decreases in body mass and soleus muscle mass of rats, which were not obviously altered by RMF. Three-point bending test showed that the mechanical properties of femurs in HU rats, including maximum load, stiffness, energy absorption and elastic modulus were not markedly affected by RMF. µCT analysis demonstrated that 4-week RMF did not significantly prevent HU-induced deterioration of femoral trabecular and cortical bone microarchitecture. Serum biochemical analysis showed that RMF did not significantly change HU-induced decrease in serum bone formation markers and increase in bone resorption markers. Bone histomorphometric analysis further confirmed that RMF showed no impacts on bone remodeling in HU rats, as evidenced by unchanged mineral apposition rate, bone formation rate, osteoblast numbers and osteoclast numbers in cancellous bone. Together, our findings reveal that RMF do not significantly affect bone microstructure, bone mechanical strength and bone remodeling in HU-induced disuse osteoporotic rats. Our study indicates potentially obvious waveform-dependent effects of electromagnetic fields-stimulated osteogenesis, suggesting that RMF, at least in the present form, might not be an optimal modality for inhibiting disuse osteopenia/osteoporosis.     

四川铁布梅花鹿自然保护区梅花鹿夏季栖息地选择

四川梅花鹿Cervus nippon sichuanicus为国家Ⅰ级重点保护动物,四川铁布梅花鹿自然保护区分布有我国现存最大的梅花鹿野生种群。2011年6-9月,采用样方法对保护区梅花鹿夏季栖息地选择进行了调查,共布设109个样方(利用样方61个,对照样方48个),测量并比较了海拔、坡度等20个生境因子。结果显示,梅花鹿偏好利用的植被类型为灌丛、草甸、针叶林,同时选择隐蔽度较高的生境;此外,距水源距离、灌木高度、灌木盖度、灌木密度、草本高度和草本盖度6个连续变量在利用样方和对照样方之间差异有统计学意义(F<0.05或U<0.05)。回归模型分析结果表明,梅花鹿夏季偏好选择草本盖度大、靠近水源和林缘的生境,回避远离水源和林缘的生境。     

The role of oxygen-increased respirator in humans ascending to high altitude

ABSTRACT: BACKGROUND: Acute mountain sickness is common for people who live in low altitude areas ascending to the high altitude. Many instruments have been developed to treat mild cases of AMS. However, long-lasting and portable anti-hypoxia equipment for individual is not yet available. METHODS: Oxygen-increased respirator (OIR) has been designed to reduce the risk of acute mountain sickness in acute exposure to low air pressure. It can increase the density of oxygen by increasing total atmospheric pressure in a mask. Male subjects were screened, and eighty-eight were qualified to perform the experiments. The subjects were divided into 5 groups and were involved in some of the tests at 4 different altitudes (Group 1, 2: 3700 m Group 3,4,5: 4000 m, 4700 m, 5380 m) with and without OIR. These tests include heart rate, saturation of peripheral oxygen (SpO2), malondialdehyde (MDA), superoxide dismutase (SOD), blood lactate (BLA) and PWC (physical work capacity) -170. RESULTS: The results showed that higher SpO2, lower heart rate (except during exercise) and better recovery of heart rate were observed from all the subjects 'with OIR' compared with 'without OIR' (P < 0.05). Moreover, compared with 'without OIR', subjects 'with OIR' in Group 1 had lower concentrations of MDA and BLA, and a higher concentration of SOD (P < 0.05), while subjects 'with OIR' in Group 2 showed better physical capacity (measured by the PWC-170) (P < 0.05). The additonal experiment conducted in a hypobaric chamber (simulating 4,000 m) showed that the partial pressure of oxygen in blood and arterial oxygen saturation were higher 'with OIR' than 'without OIR' (P < 0.05). CONCLUSIONS: We suggested that OIR may play a useful role in protecting people ascending to high altitude before acclimatization.     

盘县十里坪喀斯特地貌的形态结构与洞穴形成过程

大洞所在的十里坪地区的喀斯特地貌在形态结构上属湿热喀斯特,新第三纪是本区碳酸盐岩体一次强烈的喀斯特化和洞穴化时期,第四纪以来新构造运动强烈的间歇性抬升,喀斯特垂直方向发育,外源水补给区流水喀斯特的解剖成为峰丛洼地（谷地）形成的基本动力,外源水的垂直方向渗透和侧向运移为洞穴初始形成并呈层状分布提供基本条件,干湿冷暖交替的气候变迁迁使这些峰丛洼地,谷地表现出许多残余特征和相应的洞内沉积类型,但无损于仍     

鄱阳湖北段白鹭和苍鹭重金属富集特征比较

水鸟对重金属的富集水平及特征是了解湿地生态系统健康状况、水鸟生境安全的重要渠道。2016年通过非损伤取样方式采集了鄱阳湖北段白鹭Egretta garzetta和苍鹭Ardea cinerea各20个卵壳样品,并收集了2种鹭鸟觅食地的土壤样品9份,利用电感耦合等离子体质谱仪对卵壳和土样中铬(Cr)、铜(Cu)、镍(Ni)、锌(Zn)、砷(As)、铅(Pb)、镉(Cd)、汞(Hg)8种重金属的残留量进行了测量,分析了重金属在2种鹭鸟卵壳中的残留量,在此基础上分析了该区域2种鹭鸟对土壤重金属富集特征。研究结果表明,8种重金属中,白鹭和苍鹭卵壳重金属残留量均以Zn最高、Cd最低。苍鹭的Pb残留量极显著高于白鹭(P<0.01)。白鹭和苍鹭卵壳对Hg的生物富集系数最高,As的最低,而苍鹭对Pb的生物富集系数极显著高于白鹭(P<0.01)。