Rhizosphere priming effect increases the temperature sensitivity of soil organic matter decomposition

The temperature sensitivity of soil organic matter (SOM) decomposition has been a crucial topic in global change research, yet remains highly uncertain. One of the contributing factors to this uncertainty is the lack of understanding about the role of rhizosphere priming effect (RPE) in shaping the temperature sensitivity. Using a novel continuous ¹³C‐labeling method, we investigated the temperature sensitivity of RPE and its impact on the temperature sensitivity of SOM decomposition. We observed an overall positive RPE. The SOM decomposition rates in the planted treatments increased 17–163% above the unplanted treatments in three growth chamber experiments including two plant species, two growth stages, and two warming methods. More importantly, warming by 5 °C increased RPE up to threefold, hence, the overall temperature sensitivity of SOM decomposition was consistently enhanced (Q₁₀ values increased 0.3–0.9) by the presence of active rhizosphere. In addition, the proportional contribution of SOM decomposition to total soil respiration was increased by soil warming, implying a higher temperature sensitivity of SOM decomposition than that of autotrophic respiration. Our results, for the first time, clearly demonstrated that root–soil interactions play a crucial role in shaping the temperature sensitivity of SOM decomposition. Caution is required for interpretation of any previously determined temperature sensitivity of SOM decomposition that omitted rhizosphere effects using either soil incubation or field root‐exclusion. More attention should be paid to RPE in future experimental and modeling studies of SOM decomposition.     

A plea for using qualitative aspects in the interpretation of ecological field data as revealed by the proof of carabid beetle assemblages of a pristine salt marsh

The evaluation of ecological field data can be done by an increasing number of quantitative methods. The application of these methods often is often blind against two kinds of problems: (i) the data often do not meet the requirements of a method, e.g., as an ultra-metric structure of the data in the case of hierarchical cluster analysis. In such cases, the result will be misleading because the presentation of results is ultra-metric independent on the structure of the data. (ii) Most of the animals are able to move actively or may drift passively by wind, etc. Therefore, species occurring by accident like vagrants have to be eliminated from the assemblage of animals at a particular site before a quantitative method is applied. In addition, the result of a quantitative analysis has to be checked for its ecological plausibility. This is a qualitative step, which can only be done by taking into account the known data on biology and ecology of the species.Some pitfalls of an exclusive application of quantitative methods will be demonstrated in this paper using a data set of salt marsh Carabidae.     

Parallel declines in species and genetic diversity in tropical forest fragments

The potential for parallel impacts of habitat change on multiple biodiversity levels has important conservation implications. We report on the first empirical test of the 'species-genetic diversity correlation' across co-distributed taxa with contrasting ecological traits in the context of habitat fragmentation. In a rainforest landscape undergoing conversion to oil palm, we show that depauperate species richness in fragments is mirrored by concomitant declines in population genetic diversity in the taxon predicted to be most susceptible to fragmentation. This association, not seen in the other species, relates to fragment area rather than isolation. While highlighting the over-simplification of extrapolating across taxa, we show that fragmentation presents a double jeopardy for some species. For these, conserving genetic diversity at levels of pristine forest could require sites 15-fold larger than those needed to safeguard species numbers. Importantly, however, each fragment contributes to regional species richness, with larger ones tending to contain more species.     

非小细胞肺癌EGFR 表达与18F-FDG-PET SUVmax 值 的相关性研究

目的:探讨非小细胞肺癌组织中EGFR蛋白在的表达与PET-CT检测的SUVmax的相关性。方法:临床收集30例非小细胞肺癌患者,每一病例首先行PET-CT检查,然后行CT导引下活检穿刺,同一病灶取2个穿刺部位,分别为肿瘤组织内SUVmax值2.5-5区域及SUVmax>5区域,采用免疫组化方法检测检测30例非小细胞肺癌肿瘤内部不同部位EGFR表达。结果:EGFR蛋白表达、SUVmax值在不同年龄、性别、病理类型中表达的差异无统计学意义(P均>0.05)。EGFR蛋白表达、SUVmax值在不同的肿瘤直径、临床分期组表达差异有统计学意义(P均<0.05)。NSCLC肿块SUVmax值与组织EGFR表达呈显著正相关(P<0.05)。结论:NSCLC组织SUV值与组织EGFR表达有显著相关性,可以为非小细胞肺癌的放疗提供指导。     

Eco-efficiency Trends in the UK Steel and Aluminum Industries

Measures of eco-efficiency—broadly understood as "getting more from less"—often include an economic and an environmental variable. The latter is often seen as the more problematic variable, particularly when used in relation to impacts of public concern. But an analysis of resource and value trends in the U.K. steel and aluminum industries over the last 30 yr showed that there are significant problems associated with using economic variables in measures of eco-efficiency at the sectoral level.
The research found that the U.K. steel and aluminum industries have improved the effectiveness with which they use natural resources, but that this has been accompanied by a decline in the economic output (value added) per unit of material or energy consumed. These seemingly contradictory results can be explained by the fall in the price of metals in real terms, and by the competitive pressures that necessitate the cutting of production costs and indirectly lead to a fall in the measure of economic output of the relevant industry.
The research also suggests a logical terminology to bring consistency and coherence to the broad field of eco-efficiency indicators, with an important distinction made between measures that examine the value output per unit of physical input, and measures that examine the physical output per unit of physical input. Both these types of indicators are important, as they highlight different aspects of eco-efficiency.     

Survival and sublethal responses of early life stages of pike exposed to low pH in artificial post-mining lake water

The threshold pH for survival of early life stages of pike Esox lucius in post-mining lakes was determined in a laboratory experiment using artificial water characterized by high concentrations of dissolved Ca, Al, Fe, Mn and SO2/4⁻. At pH 3·50–4·00, high mortality was observed before hatching. At pH 4·00 and 4·25, hatching rates were reduced compared with the controls (pH 7·40), and many embryos died in a partly hatched state. Hatching success of embryos exposed to pH levels of 4·50 or higher was not affected. However, at pH 5·00 many newly hatched embryos were deformed. Furthermore, pike exposed to pH 4·00–5·00 did not start feeding. At pH 4·75 and below, mortality increased to 100%, and at pH 5·00, only few eleutheroembryos which were in extremely poor condition survived to the end of the experiment. At pH 5·50, survival was in the same range as in the control group, but growth was reduced. Therefore, early life stages of pike are expected to survive in Lustian post-mining lakes when a pH of 5·50 and above is reached and maintained.     

Relationships Among Stop Codon Usage Bias, Its Context, Isochores, and Gene Expression Level in Various Eukaryotes

It is well known that stop codons play a critical role in the process of protein synthesis. However, little effort has been made to investigate whether stop codon usage exhibits biases, such as widely seen for synonymous codon usage. Here we systematically investigate stop codon usage bias in various eukaryotes as well as its relationships with its context, GC3 content, gene expression level, and secondary structure. The results show that there is a strong bias for stop codon usage in different eukaryotes, i.e., UAA is overrepresented in the lower eukaryotes, UGA is overrepresented in the higher eukaryotes, and UAG is least used in all eukaryotes. Different conserved patterns for each stop codon in different eukaryotic classes are found based on information content and logo analysis. GC3 contents increase with increasing complexity of organisms. Secondary structure prediction revealed that UAA is generally associated with loop structures, whereas UGA is more uniformly present in loop and stem structures, i.e., UGA is less biased toward having a particular structure. The stop codon usage bias, however, shows no significant relationship with GC3 content and gene expression level in individual eukaryotes. The results indicate that genomic complexity and GC3 content might contribute to stop codon usage bias in different eukaryotes. Our results indicate that stop codons, like synonymous codons, exhibit biases in usage. Additional work will be needed to understand the causes of these biases and their relationship to the mechanism of protein termination. [Reviewing Editor: Dr. Manyuan Long]     

一种新型一体化防护服的抗荷性能

目的:探讨一种新型一体化防护服(IPS)的抗荷性能.方法:在离心机上首先测定10名受试者的基础 Gz耐力,然后受试者穿IPS充气,测此时的松弛耐力,两者之差即为IPS的抗荷性能.结果:受试者穿IPS时的松弛耐力明显高于基础耐力(P＜0.01),其抗荷性能达到(2.38±0.38)G.结论:IPS的抗荷性能较好,可满足我国高性能战斗机的需要.     

Limit values for decomposition and convergence process of lignocellulose fraction in decomposing leaf litter of 14 tree species in a cool temperate forest

We examined limit values for decomposition and lignocellulose index (LCI, the ratio of acid-soluble holocellulose to acid-soluble holocellulose plus acid-insoluble lignin and lignin-like substances) in leaf litter decomposition of 14 tree species over 3 years. The study was carried out on upper (moder) and lower parts (mull) of a forest slope that showed different humus accumulation forms in a cool temperate forest in Japan. Limit values for accumulated mass loss of litter ranged from 46.8% to 94.1% and were not different between the sites. Limit values were positively correlated to initial LCI and lignin content. Final values of LCI of 14 litter types at the end of the study period showed a convergent trend among litter types at 0.25–0.26 as compared to their initial values (0.41 mean). The final LCI was not different between the sites. A review of limit values and initial and final values of LCI in leaf litter of temperate and boreal forests indicated that the limit values and final LCI in litter types in Japan were lower than those in Europe and North America, which can be primarily ascribed to lower initial LCI in Japan.     

Trypanosoma cruzi: distinct patterns of infection in the sibling caviomorph rodent species Thrichomys apereoides laurentius and Thrichomys pachyurus (Rodentia, Echimyidae)

Thrichomys apereoides, a caviomorph rodent species common in a highly endemic area for Chagas disease in Brazil, may act as reservoir of the parasite. However, no information is available concerning its sibling species Thrichomys pachyurus, found in the Pantanal region, where Trypanosoma cruzi is found only in the enzootic cycle. We followed up the cross infection of these cryptic species with two isolates derived from naturally infected T. pachyurus and Thrichomys apereoides laurentius. No regional co-adaptation between Thrichomys species and the regional isolates were noticed. However, significant differences in the outcome of the infection were observed. T. a. laurentius was more resistant than T. pachyurus, as expressed by lower parasitemia and less histopathological damage. The routine biochemical markers used for laboratory rodents were unsuitable for follow up of infection in Thrichomys spp, since they did not correlate with the histopathological findings or allowed the kinetic follow-up of tissue colonization by the parasite.