On pessimism in Australian ecology

In the face of massive human impacts upon the environment, a prevailing attitude among Australian ecologists seems to have become one of pessimism. The essay explores the consequences of this stance. Pessimism arises understandably from personal values favouring care for the natural world under conditions of rapid global change. Expression of such values is in no way illegitimate; pessimism is as justifiable a perspective as is optimism when interpreting ecology. Examples are mentioned of areas of Australian ecology where pessimism does not predominate, and where the ecological changes being wrought by the Anthropocene are accepted. But, the predominance of gloom can cause ecologists to flirt with exaggeration and with misanthropy, and perversely it can cause them to strive to prevent ecological change even though the discipline is rooted in the reality of flux. Most profoundly, it causes many citizens to switch off: gloom has limited capacity to motivate, whereas hope is the elixir of action. Because of predominant negativity, we risk losing the confidence of society. The solution is for the discipline to develop more diverse strands of interpretation, characterized by more equal doses of acceptance and hope. By balancing dejection, ecology may achieve the efficacy in debate and decision‐making that it warrants in these challenging times.     

声弹性成像结合等硬度区域面积测量技术在离体血栓模型中的应用价值

目的:探讨一种声弹性成像定量分析方法用于评价深静脉血栓(DVT)患者血栓进展的情况。方法:经处理得12条大隐静脉标本,采用声弹性成像技术分别在1d、3d、6d、9d采集静脉标本中血凝块声弹性图像;应用等硬度区域面积测量技术(AMEHR)进行处理,计算血凝块区域在静脉标本中所占的比例,并进行数据分析。结果:经由AMEHR技术分析,在1d、3d、6d、9d静脉标本中,血凝块区所占比例分别为46.72%±12.16%,71.93%±7.24%,82.17%±5.17%,91.92%±3.69%。随着血栓时间的增加,血凝块区域所占比例逐渐增加,且差异有统计学意义(P0.05);随着时间的进展,血凝块增长的速率逐渐降低(1-3d:25.21%,3-6d:10.24%,6-9d:9.75%)。结论:AMEHR技术对血栓形成时间的评估上有一定的应用价值,有望为评估血栓形成时间提供参考。     

Adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus)

We examined adult male-infant interactions in wild muriquis (Brachyteles arachnoides hypoxanthus), a species in which close relatedness among philopatric males and high paternity uncertainty should minimize both aggressive and affiliative behavior by males toward infants. As expected, male-infant interactions were extremely rare during this 10-month field study. None were observed in over 236 hr of observation on a cohort of six infants (0 – 13 months old). The 29 interactions observed ad lib involved 5 of the 6 infants and 9 of the 16 adult males in the group. All of the male-infant interactions were affiliative, but extremely brief. The median duration of interactions was only 0.33 min, and none lasted longer than 1.52 min. Infants always initiated, and nearly always terminated, their interactions with adult males. The indifference that appears to characterize muriqui male-infant interactions differs from the ways in which other male primates interact with infants when protection of genetic interests or investment in mating effort are involved.     

Reference values for trace and ultratrace elements in human serum determined by double-focusing ICP-MS

Reference values for trace and ultratrace elements concentrations in healthy human serum, measured by double-focusing inductively coupled plasma-mass spectrometry (ICP-MS), are presented. Blood donors from Asturias (Spain) were selected as the reference population (n=59). Blood samples were collected, after donation, taking the necessary precautions to avoid contamination. All subjects analyzed had normal renal function and nutritional status, as shown from their creatinine and albumin levels. A total number of 14 elements (Al, Ca, Cr, Mn, Fe, Co, Cu, Zn, Rb, Sr, Mo, Cd, Pb, and U) were monitored almost simultaneously. Serum samples were diluted 1+4 with ultrapure water and matrix interferences were corrected using Sc, Ga, Y, and Tl as internal standards. Fe, Cu, and Zn were also determined by isotope dilution analysis (IDA). Reference trace element concentrations intervals observed containing 95% of the reference distribution after excluding outliers are presented. Fourteen serum samples from hemodialysis patients were also analyzed for comparison. High levels of Al, Cr, Sr, Mo, Mn, Pb, U, Co, and Cu and low levels of Fe, Zn, and Rb were found in the serum samples from hemodialysis patients compared to the corresponding reference values observed in this work.     

Projecting species’ vulnerability to climate change: Which uncertainty sources matter most and extrapolate best?

Species distribution models (SDMs) are commonly used to assess potential climate change impacts on biodiversity, but several critical methodological decisions are often made arbitrarily. We compare variability arising from these decisions to the uncertainty in future climate change itself. We also test whether certain choices offer improved skill for extrapolating to a changed climate and whether internal cross‐validation skill indicates extrapolative skill. We compared projected vulnerability for 29 wetland‐dependent bird species breeding in the climatically dynamic Prairie Pothole Region, USA. For each species we built 1,080 SDMs to represent a unique combination of: future climate, class of climate covariates, collinearity level, and thresholding procedure. We examined the variation in projected vulnerability attributed to each uncertainty source. To assess extrapolation skill under a changed climate, we compared model predictions with observations from historic drought years. Uncertainty in projected vulnerability was substantial, and the largest source was that of future climate change. Large uncertainty was also attributed to climate covariate class with hydrological covariates projecting half the range loss of bioclimatic covariates or other summaries of temperature and precipitation. We found that choices based on performance in cross‐validation improved skill in extrapolation. Qualitative rankings were also highly uncertain. Given uncertainty in projected vulnerability and resulting uncertainty in rankings used for conservation prioritization, a number of considerations appear critical for using bioclimatic SDMs to inform climate change mitigation strategies. Our results emphasize explicitly selecting climate summaries that most closely represent processes likely to underlie ecological response to climate change. For example, hydrological covariates projected substantially reduced vulnerability, highlighting the importance of considering whether water availability may be a more proximal driver than precipitation. However, because cross‐validation results were correlated with extrapolation results, the use of cross‐validation performance metrics to guide modeling choices where knowledge is limited was supported.     

Obtaining Critical Values for Simultaneous Confidence Intervals and Multiple Testing

There are many situations where it is desired to make simultaneous tests or give simultaneous confidence intervals for linear combinations (contrasts) of population or treatment means. Somerville (1997, 1999) developed algorithms for calculating the critical values for a large class of simultaneous tests and simultaneous confidence intervals. Fortran 90 and SAS‐IML batch programs and interactive programs were developed. These programs calculate the critical values for 15 different simultaneous confidence interval procedures (and the corresponding simultaneous tests) and for arbitrary procedures where the user specifies a combination of one and two sided contrasts. The programs can also be used to obtain the constants for “step‐down” testing of multiple hypotheses. This paper gives examples of the use of the algorithms and programs and illustrates their versatility and generality. The designs need not be balanced, multiple covariates may be present and there may be many missing values. The use of multiple regression and dummy variables to obtain the required variance covariance matrix is illustrated. Under weak normality assumptions the methods are “exact” and make the use of approximate methods or “simulation” unnecessary.     

Application of a Probabilistic Risk Assessment Methodology to a Lead Smelter Site

Exposure of children to lead in the environment was assessed at the Murray Smelter Superfund site using both a deterministic risk assessment approach, the Integrated Exposure Uptake Biokinetic (IEUBK) model, and a probabilistic approach, the Integrated Stochastic Exposure (ISE) model. When site-specific data on lead in environmental media were input as point estimates into the IEUBK model, unacceptable risks were predicted for children living within five of eight study zones. The predicted soil cleanup goal was 550?ppm. Concentration and exposure data were then input into the ISE model as probability distribution functions and a one-dimensional Monte Carlo analysis (ID MCA) was run to predict the expected distribution of exposures and blood lead values. Uncertainty surrounding these predictions was examined in a two-dimensional Monte Carlo analysis (2-D MCA). The ISE model predicted risks that were in the same rank order as those predicted by the IEUBK model, although the probability estimates of exceeding a blood lead level of 10?µg/dl (referred to as the P10) from the ISE model were uniformly lower than those predicted by the IEUBK model. The 2-D MCA allowed evaluation of the confidence around each P10 level, and identified the main sources of both uncertainty and variability in exposure estimates. The ISE model suggested cleanup goals ranging from 1300 to 1500 ppm might be protective at this site.     

不同年龄阶段杉木人工林植物热值分析

应用会同国家野外科学观测研究站的连续定位测定资料,研究了杉木林不同林龄阶段乔木、灌木、草本和枯死物热值动态变化。结果表明:同一林龄阶段,杉木叶的热值皮枝干根,杉木各器官热值随林龄增加而增大;相同林龄的灌木叶热值枝根,草本地上部分热值根,灌木和草本的热值随林龄增大而减少;同一林龄的凋落叶的热值凋落枝碎屑死根,枯死物热值随林龄增加而增大;整个杉木林系统,乔木层热值灌木草本枯死物;灰分含量与会同杉木器官热值的大小与变化关联性不密切,与灌木、草本呈显著负相关(P0.05);会同杉木热值随林龄变化与器官随林龄增大木质化程度提高,以及不同年份的降水量、太阳辐射、温度有关;林分不同层次植物热值的变化与某个层次的植物接受的光能资源量关系密切。