Head-to-head comparison of cardiac troponin T and troponin I in patients without acute coronary syndrome: a systematic review

Background: Cardiac-specific troponin T (cTnT) and troponin I (cTnI) are considered diagnostically equal in patients with acute coronary syndrome (ACS). The aim of this systematic review was to compare the prevalence and prognostic strength of elevations of cTnT and cTnI in patients with other conditions than ACS.

Methods: A systemic review was conducted in concordance with the PRISMA guidelines. The studies were identified by searching PubMed, EMBASE and Cochrane Central Register, from May to August 2016. Studies measuring both cTnT and cTnI in populations without ACS were eligible.

Results: Twenty-nine studies were included (n?=?25,859). Seventeen studies reported on prognostic information with follow-up time ranging for 30?d–5?years. Elevation above the 99th percentile (reference value for a healthy population) in non-ACS population was reported to be 0–39% for cTnI and 40–100% for cTnT. Elevation of cTnT tends to be a superior predictor for all-cause mortality and elevation of cTnI tends to be a superior predictor for cardiovascular related mortality.

Discussion: In the absence of ACS, elevation of cTnT is more frequent than elevation of cTnI.

Conclusion: Both cTnT and cTnI elevations have important prognostic information regarding morbidity, cardiac mortality and all-cause mortality.     

A metabolic syndrome in terrestrial ectotherms with different elevational and distribution patterns

The metabolic performance of ectotherms is expected to be driven by the environment in which they live. Ecologically similar species with contrasting elevation distributions occurring in sympatry at mid‐elevations, provide good models for studying how physiological responses to temperature vary as a function of adaptation to different elevations. Under sympatry, at middle elevations, where divergent species ranges overlap, sympatric populations are expected to have similar thermal responses, suggesting similar local acclimation or adaptation, while observed differences would suggest adaptation to each species’ core range. We analysed the metabolic traits of sympatric species pairs from three ectotherm groups: reptiles (Reptilia: Lacertidae), amphibians (Amphibia: Salamandridae) and beetles (Coleoptera: Carabidae), living at different elevations, in order to test how adaptation to different elevations affects metabolic responses to temperature. We experimentally tested the thermal response of respiration rate (RR) and estimated potential metabolic activity (PMA) at three temperature regimes surrounding the groups’ optimal activity body temperatures. RR was relatively similar among groups and showed a positive response to increasing temperature, which was more pronounced in the high‐elevation species of reptiles and beetles. Relative to RR, PMA displayed a stronger and more consistent positive response to increased temperature in all three groups. For all three groups, the average biochemical capacity for metabolism (PMA) was higher in the range‐restricted, high‐elevation species, and this difference increased at higher temperatures in a consistent manner. These results, indicating consistent pattern in three independently evolved animal groups, suggest a ubiquitous adaptive syndrome and represent a novel understanding of the mechanisms shaping spatial biodiversity patterns. Our results also highlight the importance of geographic patterns for the mechanistic understanding of adaptations in physiological traits, including species’ potential to respond/adapt to global climate changes.     

云丘山不同海拔梯度橿子栎叶性特征研究

在吕梁山南段云丘山,以橿子栎为主要研究对象,采用野外调查和室内实验相结合的方法,对比叶面积(SLA)、叶面积(LA)、叶干物质含量(LDMC)、叶长宽比(L/W)、叶绿素含量(Chl)以及叶氮含量等有代表性的指标进行分析.结果表明：(1)随着海拔梯度的增加,橿子栎 L/W、Chl、SLA、LA、单位面积的叶氮含量(N area )、单位重量的叶氮含量(N mass )、叶饱和鲜重和叶干重均呈先上升后下降的趋势,在海拔1180 m 处有最大值;LDMC 与海拔呈显著负相关(P ＜0．05);(2)橿子栎 LA 与 SLA 和 N mass 呈极显著正相关关系(P ＜0．01),与 LDMC 呈显著负相关关系(P ＜0．05),与 N area呈极显著负相关关系(P ＜0．01);(3)橿子栎叶片 SLA与 L/W 呈显著正相关(P ＜0．05),与 N mass 呈极显著正相关关系(P ＜0．01),橿子栎叶片 SLA 与 LDMC 和N area呈显著负相关关系(P ＜0．05);(4)橿子栎 LDMC 与 N area 呈显著正相关(P ＜0．05).通过对云丘山景区橿子栎叶片性状随海拔变化规律的研究,可以探索橿子栎叶片性状与海拔梯度变化的关系以及最适生长环境,从而为景区橿子栎林的保护和抚育提供理论依据,为合理开发橿子栎林资源提供基础资料.     

刺梨低海拔引种栽培研究初报

1993年2月从保靖县梅花乡海拔300m高的山地引进了一批大果形的刺梨枝条,在低海拔（45.5m）扦插繁殖,经过4个的栽培试验初步弄清了其物候期、结果习性及果实生长动态,为选育适应低海拔栽培的刺梨优良品种提供了科学依据。     

青藏高原东缘不同海拔波缘风毛菊资源分配及花部特征对种子数目和质量的影响

通过采样调查法和烘干称量法检测了青藏高原东缘不同海拔种群波缘风毛菊(Saussurea undulata)花期与果期的形态特征, 研究了其花期与果期的资源分配, 并对花期花部特征对果期种子特征的影响作出分析。结果表明: 1)波缘风毛菊在花期将更多的资源投入繁殖器官, 而在果期增加了对种子的资源投资; 2)波缘风毛菊花期部分花部特征的变异导致其果期产生的种子随海拔升高数量减少、百粒重增加, 因为波缘风毛菊需要在高寒草甸的极端环境下保证每粒种子的存活能力, 因此采取了产生更少但更大种子的生存策略。     

秦岭太白山木本植物物种多样性的梯度格局及环境解释

物种多样性沿环境梯度的分布格局是生物多样性研究的重要议题,而海拔梯度包含了各种环境因子的综合影响,因此对于探讨物种多样性沿环境梯度的分布格局具有重要意义。秦岭山脉地处我国暖温带向亚热带的过渡带,其植被垂直带和物种多样性分布格局对于研究我国南北部植被分异特征具有重要意义。基于对秦岭山脉太白山南北坡海拔1200—3750m之间的垂直样带调查的83个样方,本文利用植被数量分析方法(DCA和TWINSPAN)和Shannon-Wiener多样性指数、Pielou指数以及Jaccard相异性系数对太白山木本植物物种多样性在南北坡沿海拔梯度分布格局进行了初步研究。结果表明：太白山的木本植物群落具有明显的环境梯度格局,海拔是决定太白山植物群落分布的主要因素,而坡向起到次要作用一植物群落类型与坡向的关系不大,当考虑群落的环境梯度格局时,DCA第一轴主要与年均温密切相关,而第二轴则取决于年平均相对湿度：乔木层和灌木层的物种具有相似的海拔梯度格局,植物群落中木本植物物种丰富度和多样性随着海拔的升高单调下降;群落均匀度随着海拔变化的规律不明显;灌木层的物种多样性比乔木层更为丰富,而南坡具有比北坡更多的物种数和更高的多样性。相邻海拔之问群落的相异性在南北坡具有不同的分布格局,在北坡2800m以下,群落相异性沿海拔梯度变化不大,而在2800m以上的高海拔地区,群落相异性随海拔的升高而降低;在南坡,随着海拔的升高,群落相异性不断减少。太白山南坡群落比北坡分布更连续。     

祁连山中部地区树轮宽度年表特征随海拔高度的变化

利用采自祁连山中部地区不同海拔高度的四个采样点的青海云杉树轮样芯 ,分别建立了树木年轮宽度年表。发现随海拔高度的上升 ,树轮宽度指数的振幅减小 ,年表的平均敏感性降低 ,样本间的一致性也逐步减小 ,上限年表与气候因子的相关性最低 ,这与目前大家普遍认同的上限树木的生长受温度控制的概念并不一致。进一步的分析表明 ,年表的敏感性随海拔高度降低主要是由于该区域树木生长的限制因子是春季降水 ,而降水随海拔高度的升高而增加 ,从而使得春季降水对树木生长的限制作用随海拔升高而逐步减弱 ;生物学指标的测定结果表明 ,生长在高海拔的树木对环境的生态适应策略发生变化 ,其生理代谢维持在较低水平 ,以避免环境变化带来的影响 ,因此生长在高海拔的青海云杉对环境变化的敏感性较差。     

植被、海拔、人为干扰对大中型野生动物分布的影响——以九寨沟自然保护区为例

利用九寨沟自然保护区内8条动物监测样线在2003—2010年的生态监测数据,分析了植被、海拔、人为干扰对大中型野生动物分布的影响,结果显示:1)本监测共记录到保护区内大中型野生动物26种,其中兽类18种,鸟类8种,属于我国Ⅰ级、Ⅱ级保护动物的分别有5种和11种。2)针阔混交林和针叶林是大中型野生动物种类最丰富的两种植被类型(分别有26种和17种),阔叶林和灌丛次之(分别为10种和12种),草地最少(2种)。3)海拔2400 m以下的地方,大中型野生动物种类稀少,为10种,2400—2599 m海拔段物种数增加至20种,之后随海拔上升物种丰富度下降。4)人为干扰显著影响大中型野生动物的空间分布:历史上的人类活动将原生森林植被转化为次生的落叶阔叶林、灌丛和草地,使树正、亚纳和尖盘等地下坡位(相对海拔0—199 m)的大中型野生动物的物种丰富度降低(分别为4、2、2种)。包括旅游活动和交通在内的人为干扰,可能导致附近50m海拔范围内保护动物的缺失,并使下坡位的某些物种向高海拔处移动。生境破碎化则使野生动物的种类组成发生改变,使原有森林内部优势种,如羚牛(Budorcas taxicolor),逐渐被适应能力强的物种,如豹猫(Prionailurus bengalensis)、雉鸡(Phasianuscolchicus)和野猪(Sus scrofa)等所取代,并将长期影响野生动物种群的存活。当前九寨沟自然保护区大中型野生动物的分布是植被、海拔与人为干扰综合作用的结果。     

Avian life history variation along altitudinal gradients: an example with cardueline finches

Elevation has long been considered a major influence on the evolution of life-history traits. Most elevation-induced variation in life history traits has been attributed to changes in climate, duration of breeding season, predation, and food limitation. I use a phylogenetic approach to show that life histories are closely associated with breeding elevation in extant cardueline finches. Finches at high elevations had smaller clutches, fewer broods, and longer incubation periods. Neither food limitation nor nest predation appear to readily account for this strong elevational variation in cardueline life histories. However, juvenile survival may be greater at higher elevations as a result of prolonged parental care and shorter natal dispersal and can potentially compensate for reduced fecundity in high-elevation finches. Received: 28 September 1996 / Accepted: 24 March 1997     

淡黄香青叶面气孔对不同海拔高度的适应表现

对比分析了分布于马衔山不同海拔高度的淡黄香青气孔复体的适应表现。结果表明：随海拔升高,植株叶片上气孔分布区域增大,叶两面气孔数量增加,气孔向外突起程度增加,孔下室及气孔张度增大。同时气孔每天的开放时间缩短。研究认为气孔复体的变化是淡黄香青适应高山低氧低二氧化碳分压的表现,同时也是植株因海拔升高造成的光合物质分配改变的结果。