Dating lightning: Dendrochronological and magnetic analyses of lightning scars

Lightning impacts on forests and trees are still understudied from a tree-ring perspective. Lighting causes direct and indirect damages on forests and trees. Trees struck by lightning can show a growth reduction and lightning storms also trigger wildfires in seasonally dry areas such as Mediterranean mountains. Here we combined dendroecological and magnetic analyses to reconstruct and assess the impact of lightning on radial growth and the magnetic properties of wood in Scots pine (Pinus sylvestris) and Black pine (Pinus nigra) in two sites with a high density of lightning impacts located in eastern Spain. We dated several lightning scars, particularly in Scots pine, formed during 1982, when a wildfire was initiated by lightning during a dry summer storm. Growth was reduced during the year when the scar was formed in both pine species, albeit this effect could be masked or amplified by other disturbances (drought, outbreaks). However, despite that short-term growth reduction scarred trees showed higher growth rates than non-scarred trees in the case of Scots pine. The intensity of magnetization did not significantly differ in wood produced before and after the lightning scar was formed. This could be due to multiple lightning hits in the same or nearby stands affecting the magnetization of wood. Wood magnetic properties should be further explored as proxies of lightning impacts in sites where scars are not formed and tree-ring information is limited such as tropical forests. Further cross-disciplinary research is required to assess the impacts of lightning on tree growth and magnetism.     

不同气候条件下慢性阻塞性肺疾病的病原学和免疫学研究

目的：探讨COPD患者不同气候条件下（雷暴、阴雨、台风）的病原学和免疫功能。方法：细菌鉴定采用VITEK全自动微生物鉴定系统。K．B纸片扩散法测定药敏。T淋巴细胞亚群测定采用单克隆抗体免疫组化荧光染色法。血清免疫球蛋白（IgG,IgA,IgM）用琼脂单向扩散法。结果：台风、雷暴、阴雨、天气气候条件60例患者痰培养阳性率分别为45％、40％、30％,占革兰阴性菌前2位分别为肺炎克雷伯杆菌、流感嗜血杆菌和肺炎克雷伯杆菌、大肠埃希杆菌及流感嗜血杆菌、铜绿假单胞菌。革兰阳性菌中分别以肺炎链球菌、金黄色葡萄球菌为主及肺炎链球菌、金黄色葡萄球菌为主和金黄色葡萄球菌、表皮葡萄球菌为主。铜绿假单胞菌、肺炎克雷伯杆菌、流感嗜血杆菌对常用抗生素具有较高的耐药性。台风、雷暴、阴雨气候条件下3组AECOPD患者CD3＋ CD4＋、CD4＋／CD8＋、IgG、IgA、IgM均明显低于健康对照组（P〈0．05）,CD8＋高于健康对照组（P〈0．05）,而发作期和缓解期无显著差异（P〉0．05）。三种气候条件下相互之间比较的细胞和体液免疫指标比较无显著差剐（P〉0．05）。结论：雷暴、阴雨、台风条件下AECOPD的患者存在病原学分布差异,对常用抗生素具有较高的耐药性,细胞和体液免疫功能进一步下降。但三者相互之间的免疫功能比较无明显差异。     

不同气候条件下慢性阻塞性肺疾病的病原学和免疫学研究

目的:探讨COPD患者不同气候条件下(雷暴、阴雨、台风)的病原学和免疫功能。方法:细菌鉴定采用VITEK全自动微生物鉴定系统,K-B纸片扩散法测定药敏。T淋巴细胞亚群测定采用单克隆抗体免疫组化荧光染色法。血清免疫球蛋白(IgG,IgA,IgM)用琼脂单向扩散法。结果:台风、雷暴、阴雨、天气气候条件60例患者痰培养阳性率分别为45%、40%、30%,占革兰阴性菌前2位分别为肺炎克雷伯杆菌、流感嗜血杆菌和肺炎克雷伯杆菌、大肠埃希杆菌及流感嗜血杆菌、铜绿假单胞菌。革兰阳性菌中分别以肺炎链球菌、金黄色葡萄球菌为主及肺炎链球菌、金黄色葡萄球菌为主和金黄色葡萄球菌、表皮葡萄球菌为主。铜绿假单胞菌、肺炎克雷伯杆菌、流感嗜血杆菌对常用抗生素具有较高的耐药性。台风、雷暴、阴雨气候条件下3组AECOPD患者CD3+、CD4+、CD4+/CD8+、IgG、IgA、IgM均明显低于健康对照组(P<0.05),CD8+高于健康对照组(P<0.05),而发作期和缓解期无显著差异(P>0.05)。三种气候条件下相互之间比较的细胞和体液免疫指标比较无显著差别(P>0.05)。结论:雷暴、阴雨、台风条件下AECOPD的患者存在病原学分布差异,对常用抗生素具有较高的耐药性,细胞和体液免疫功能进一步下降。但三者相互之间的免疫功能比较无明显差异。