Spatial Imprint of Food Consumption: A Historical Analysis for Sweden, 1870–2000

Depending on quantity and composition of food as well as on production conditions and techniques, the space needed to sustain an individual’s nourishment varies. The amount of space needed also depends on the use of resources such as energy, water, and fertilizers, as well as potential land degradation and water pollution. Our study focuses on the changing spatial imprint of an average inhabitant of an expanding Swedish city, Linköping, from 1870 to 2000 taking into account both shifts in consumption as well as agricultural productivity and practices. Despite the distinctly larger amount of animal food products, such as meat and fish, consumed in 2000, we calculate the area needed to sustain an individual’s annual food consumption could be less than one fourth of that needed in 1870. However, if the import of various globally produced foods is included in our calculations, the land needed to sustain the consumption of an inhabitant of Linköping in 2000 doubles. We also argue that an examination of this regional imprint can be used to explore and evaluate possibilities for regional development.     

Bioprocess control from a multivariate process trajectory

A multivariate bioprocess control approach, capable of tracking a pre-set process trajectory correlated to the biomass or product concentration in the bioprocess is described. The trajectory was either a latent variable derived from multivariate statistical process monitoring (MSPC) based on partial least squares (PLS) modeling, or the absolute value of the process variable. In the control algorithm the substrate feed pump rate was calculated from on-line analyzer data. The only parameters needed were the substrate feed concentration and the substrate yield of the growth-limiting substrate. On-line near-infrared spectroscopy data were used to demonstrate the performance of the control algorithm on an Escherichia coli fed-batch cultivation for tryptophan production. The controller showed good ability to track a defined biomass trajectory during varying process dynamics. The robustness of the control was high, despite significant external disturbances on the cultivation and control parameters.     

川西亚高山不同暗针叶林群落类型的冠层降水截留特征

在林分和小流域尺度上,应用模型研究了四川卧龙亚高山暗针叶林冠层的降水截留特征.结果表明:生长季节(5—10月),箭竹-岷江冷杉原始林冠层截留系数在33%～72%之间,平均48%;冠层截留量与降水量之间呈显著的线性关系,截留系数与降水量之间呈负指数函数关系;试验小流域内,植被冠层最大截留量的平均值为1.74mm,不同林分间的差异显著,其顺序为藓类-箭竹-岷江冷杉林>草类-箭竹-岷江冷杉林>藓类-杜鹃-岷江冷杉林>草类-杜鹃-岷江冷杉林>杜鹃灌丛;冠层最大截留量与叶面积指数(LAI)之间呈极显著的线性关系;冠层截留量、冠层最大截留量、附加截留量分别占同期降水量的39%、25%和14%.所选模型对整个生长季平均截留量的模拟效果较好,相对误差为9%～14%.     

广东沿海与粤北山区中小型水库浮游生物群落比较分析

于丰水期和枯水期对广东山区水库(赤石迳水库)、沿海水库(大水桥、赤沙水库)三个水库的湖泊区和河流区进行研究,分析水质和浮游生物群落结构。三个水库之间的浮游生物群落均有所区别,地理位置和地形不同而引起的温度差异以及外源性营养盐输入是造成浮游生物种类和数量差异的主要原因。沿海水库不分层,而山区水库丰水期温跃层明显。各水库的氮磷比均较高,chl.a水平主要受磷限制,沿海水库则多喜暖性的种类,如裸藻、隐藻、沙居剑水蚤等,山区水库发现较多喜冷性浮游生物,如金藻、透明溞等,丰水期的甲藻丰度也相对高于枯水期。     

【特约论文】寒武纪大爆发的过去、现在与未来

人类探索认识寒武纪大爆发的过程先后经历了神创论、渐变论和爆发式演化思想的影响, 形成了越来越接近真理的重要科学认识。寒武纪大爆发本质上是动物门类的大爆发, 同时伴随着属种多样性的增长、体型增大、生物矿化以及海洋生态系统的重大变革。寒武纪大爆发是多因素制衡的自然历史过程, 任何单因素的内、外因驱动假说都不足以解释寒武纪大爆发的复杂过程。分子遗传基础和宜居环境分别是寒武纪大爆发的内在和外在必要条件, 但不是必要充分条件。因此, 寒武纪大爆发, 与其他所有生命演化事件一样, 必须通过生态作用实现。寒武纪大爆发是在氧气和其他资源不太受限、环境多变、生态荒芜的外在条件下, 基因发育调控系统预先高配的内在条件下, 发生的动物门类大爆发。在埃迪卡拉纪晚期, 多细胞的文德生物与动物采取了不同的体型发育策略和演化途径, 共享海底两千万年后, 文德生物灭绝。此后, 动物在寒武纪最初的两千万年间快速分异演化, 产生了大量演化结局各不相同的动物门类, 生态适应策略同步分化, 形成了以动物为主导的海洋生态系统, 踏上显生宙的演化征程。目前对寒武纪大爆发的探索和研究存在着偏向性或局限性, 主要关注动物门类演化和生存环境氧化还原条件, 没有将海洋生态系统作为统一整体开展全面系统的研究工作。未来探索有必要在全球范围内开展广泛全面的研究工作, 揭示寒武纪大爆发时期海洋生态系统的时空演变。     

寒武专辑封面介绍:寒武纪大爆发时期海洋生态系统重建工作模型(见本期特邀论文张兴亮, 2021)。

：寒武纪大爆发不仅引发了动物门类多样性的形成,而且构建形成了现代生态系统的雏形。背景以澄江动物群化石复原为底纹,预示动物门类构型形成,是现代生物多样性和生态体系统起源点,借用中国阴阳,寓意生物与环境相互作用,地球演化形成当今生态系统和宜居环境。     

寒武纪早期澄江生物群中受创伤的中间型始莱德利基三叶虫(Eoredlichia intermedia)

三叶虫是寒武纪海洋中的常见动物,其受伤愈合现象的化石记录可以反映生态系统内物种之间竞争关系。中国华南寒武纪早期澄江化石生物群因保存软躯体构造化石而成为研究寒武纪大爆发时期古海洋生态群落的绝佳窗口,然而,澄江生物群中三叶虫受伤愈合现象的化石至今未见报道。中间型始莱德利基虫(Eoredlichia intermedia Lu,1940)是澄江生物群的常见物种,也是我国寒武系第二个三叶虫化石带的标准带化石。在2 000余枚中间型始莱德利基虫标本中,发现两枚成体标本的头甲侧边缘、颊刺和胸甲肋节保存了不同程度的残缺。据此推测,Eoredlichia intermedia在生命活动过程中曾受到碎壳型捕食动物的攻击或其他伤害而形成伤口。伤口部位边缘加厚且光滑,显示了明显的愈合痕迹。这些特征表明始莱德利基虫在受到非致死的伤害后,具备自身修复损伤的能力。这是迄今所知最为古老的,也是在澄江生物群中首次发现的三叶虫受伤并且愈合的标本,反映了寒武纪第二世第三期底栖生态系统中碎壳型捕食者和三叶虫猎物之间的军备竞赛生态关系。     

Serum S100β is a Better Biomarker than Neuron-Specific Enolase for Sepsis-Associated Encephalopathy and Determining Its Prognosis: A Prospective and Observational Study

S100β and neuron-specific enolase (NSE) are brain injury biomarkers, mainly used in brain trauma, cerebral stroke and hypoxic ischemia encephalopathy. The aim of this study was to study the clinical significance of serum S100β and NSE in diagnosing sepsis-associated encephalopathy (SAE) and predicting its prognosis. This was a prospective and observational study. Clinical data of septic patients were collected within 24 h after ICU admission from May 2012 to April 2013. We evaluated the level of consciousness twice per day. SAE was defined as cerebral dysfunction in the presence of sepsis that fulfilled the exclusion criteria. The infection biochemical indicators, Glasgow coma scale (GCS) score, acute physiology and chronic health evaluation score II, serum NSE and S100β were newly measured or evaluated for SAE patients. Finally, hospital mortality, bacteriological categories, length of ICU stay and length of hospital stay were also recorded for all enrolled patients. The data was analyzed with the Chi square test, two-sample t test or Mann–Whitney U test between two groups. The correlation between two factors was analyzed using the Pearson or Spearman analysis. Receiver operating characteristic (ROC) curves were used to determine the ability of S100β and NSE in diagnosing SAE and predicting the hospital mortality. In addition, cut-off points were obtained from the curves to determine the highest sum of sensitivity and specificity. Of 112 enrolled patients, 48 patients were diagnosed with SAE. The serum S100β and NSE concentrations in SAE patients were both significantly higher than in non-SAE patients 0.306 (IQR 0.157–0.880) μg/L vs. 0.095 (IQR 0.066–0.177) μg/L, 24.87 (IQR 31.73–12.73) ng/mL vs. 15.49 (IQR 9.88–21.46) ng/mL, P < 0.01]. GCS scores were related more closely to S100β than NSE (?0.595 vs. ?0.337). S100β levels of 0.131 μg/L diagnosed SAE with 67.2 % specificity and 85.4 % sensitivity in the ROC curve, the area under the curve was 0.824 (95 % confidence interval 0.750–0.898). NSE levels of 24.15 ng/mL diagnosed SAE with 82.8 % specificity and 54.2 % sensitivity, and the area under the curve was 0.664 (95 % confidence interval 0.561–0.767). In addition, the area under the curve for S100β for predicting hospital mortality was larger than for NSE (0.730 vs. 0.590). Serum S100β concentrations in SAE patients were significantly higher than in non-SAE patients. These may be related to the severity of SAE and may predict the outcome of sepsis. The efficacy and sensitivity of serum S100β in diagnosing SAE were high, but it had a low specificity. Moreover, compared to NSE, serum S100β was better for both diagnosing SAE and predicting the outcome of sepsis.     

Influence of Alpha-2-Macroglobulin 5 bp I/D and Ile1000Val Polymorphisms on the Susceptibility of Alzheimer’s disease: A Systematic Review and Meta-analysis of 52 Studies

Accumulating studies have evaluated the association of Alpha-2-Macroglobulin gene (A2M) 5 bp insertion/deletion (5 bp I/D, rs3832852) and Ile1000Val (rs669) polymorphisms with Alzheimer’s disease (AD) risk, but the results remain inconclusive. To investigate whether these two polymorphisms facilitate the susceptibility to AD, we conducted a comprehensive systematic review and meta-analysis. Databases of PubMed, Embase, Web of Science, Medline, CNKI, and Google Scholar were searched to get the genetic association studies. All statistical analyses were conducted with Review Manager 5.2 and STATA11.0. Fifty-two articles were included in the final meta-analysis. We performed meta-analysis of 39 studies involving 8,267 cases and 7,932 controls for the 5 bp I/D polymorphism and 27 studies involving 6,585 cases and 6,637 controls for the Ile/Val polymorphism. Overall results did not show significant association between these two polymorphisms and AD risk in dominant, recessive, and multiplicative genetic models. On the stratification analyses by ethnicity and APOE ε4 status with genotypes of polymorphism sites, similar negative associations were found. The meta-analysis suggests that there is no enough evidence for associations of A2M gene polymorphisms (5 bp I/D, Ile1000Val) with AD risk at present, even after stratification by ethnicity and APOE ε4 with genotypes of polymorphism sites. However, due to the heterogeneity in the meta-analysis, the results should be interpreted with caution.