CO2-emission reduction in China’s residential building sector and contribution to the national climate change mitigation targets in 2020

Between 1980 and 2007, in the Chinese building sector in urban and rural areas, coal was mainly substituted with electricity and natural gas. Growing income will further increase energy consumption and CO₂-emissions in the building sector. Using an econometric model, disaggregated energy demand and related CO₂-emissions in the residential sector as well for the whole economy are estimated and forecasted until 2050. In 2009, the Chinese government pledged itself to reduce CO₂-intensity by 40%?C45% in 2020 compared to 2005. Aim of this article is to assess to which extent the measures in the building sector in China can contribute to this target. Main results of the analysis are: (a) The primary energy source coal was mainly substituted by electricity generated with coal. Apart from convenience gains, the environmental advantages are questionable. (b) Between 2010 and 2050, energy demand in the building sector will grow by 2.0%?C4.1% per annum leading to CO₂-emissions at least almost tripling from about 560 mill. tons in 2010 to about 1,500 mill. tons in 2050. (c) The energy efficiency gains in the building sector and other sectors of the Chinese economy, however, are not enough to fulfill the national CO₂-intensity targets. The reduction of the CO₂-intensity of GDP would be 37.2% in the BAU-scenario, and 31.9% in the LOW-scenario. Only in the HIGH-scenario (46.3%), the economy is growing efficient enough relative to the induced CO₂-emissions. The remaining CO2-emission reductions could be gained by additional promotion of renewable energies (mainly solar and geo-thermal) in the building sector.     

Sperm carriers in Silurian sea scorpions

Invasion of the land by arachnids required adaptations of numerous organs, such as gills evolving into lungs, as well as mechanisms facilitating sperm transfer in a terrestrial environment. Many modern arachnids use spermatophores for this purpose, i.e. sperm transmitters detached from the body. Exceptionally preserved Silurian (423?Ma) fossils of Eurypterus tetragonophthalmus Fischer, 1839 (Chelicerata: Eurypterida) preserve so-called 'horn organs' which we here demonstrate as being equivalent to the spermatophore-producing parts of the genital tract in certain modern arachnids. This clarifies a long-running debate about sexing eurypterids based on the shape of the median abdominal (or genital) appendage. To our knowledge this is also the oldest direct evidence for spermatophore-mediated sperm transfer in the fossil record and suggests that eurypterids had evolved mating techniques using spermatophores as early as the Silurian, a valuable prerequisite for life on land. Spermatophores are absent in sea spiders (Pycnogonida) and horseshoe crabs (Xiphosura); thus the shared presence of sclerotized sperm-transfer devices in eurypterids and arachnids is a novel character, newly elucidated here, which offers explicit support for (Eurypterida + Arachnida). For this clade the name Sclerophorata n. nov. is proposed. Arachnida can be further defined by fusion of the originally paired genital opening.     

Environmental assessment of green hardboard production coupled with a laccase activated system

European consumption of wood-based panels reached record levels in recent years driven mostly by demand from end-use sectors: residential construction, furniture, cabinets, flooring and mouldings. The main panel types are composite boards such as particleboard, high density fiberboard (HDF), medium-density fiberboard (MDF) and other adhesively bonded composites such as plywood and wet-process fiberboard (hardboard). The synthetic resins used in their manufacture come from non-renewable resources, such as oil and gas. Several consequences are associated to this type of adhesives: variation in the availability and cost of these wood adhesives depends on raw materials, the formaldehyde emissions as well as the limited recyclability of the final product. Hence, in the search for alternatives to petroleum-based wood adhesives, efforts are being devoted to develop adhesives by using phenolic substitutes based on lignin, tannin or starch. In this context, the forest industry is increasingly approaching to enzyme technology in the search of solutions. The main goal of this study was to assess the environmental impacts during the life cycle of a new process for the manufacture of hardboards manufacture, considering the use of a two-component bio-adhesive formulated with a wood-based phenolic material and a phenol-oxidizing enzyme. This new product was compared to the one manufactured with the conventional phenol-formaldehyde resin. The study covers the life cycle of green hardboards production from a cradle-to-gate perspective, analysing in detail the hardboard plant and dividing the process chain in three subsystems: Fibers Preparation, Board Forming and Board Finishing.Auxiliary activities such as chemicals, bio-adhesive, wood chips, thermal energy and electricity production and transport were included within the system boundaries.Global warming (GW), photochemical oxidant formation (PO), acidification (AC) and eutrophication (EP) were the impact categories analysed in this study. Additionally, the cumulative energy demand was evaluated as another impact category. According to the results, four stages significantly influenced the environmental burdens of the production system: laccase production, on-site thermal energy and electricity production as well as wood chipping stage. Due to the environmental impact associated to the production of green bonding agents, a sensitivity analysis with special focus on the eutrophying emissions was carried out by evaluating the amount of laccase and lignin based phenolic material used. The combined reduction in both bonding agents may slightly reduce the contributions to this impact category. In addition, a hypothetical scenario with no laccase and with a higher concentration of the lignin based material (25% more) could improve the environmental profile in all impact categories with a reduction of 1.5% in EP.Further research should focus mainly on laccase production, in order to reduce its energy demand as well as on the amount of green adhesive required to obtain mechanical and swelling properties similar to those of conventional hardboard.     

Multicenter clinical experience with non-invasive cell-free DNA screening for monosomy X and related X-chromosome variants

Objective

We aimed to investigate how the presence of fetal anomalies and different X chromosome variants influences Cell-free DNA (cfDNA) screening results for monosomy X.

Methods

From a multicenter retrospective survey on 673 pregnancies with prenatally suspected or confirmed Turner syndrome, we analyzed the subgroup for which prenatal cfDNA screening and karyotype results were available. A cfDNA screening result was defined as true positive (TP) when confirmatory testing showed 45,X or an X-chromosome variant.

Results

We had cfDNA results, karyotype, and phenotype data for 55 pregnancies. cfDNA results were high risk for monosomy X in 48/55, of which 23 were TP and 25 were false positive (FP). 32/48 high-risk cfDNA cases did not show fetal anomalies. Of these, 7 were TP. All were X-chromosome variants. All 16 fetuses with high-risk cfDNA result and ultrasound anomalies were TP. Of fetuses with abnormalities, those with 45,X more often had fetal hydrops/cystic hygroma, whereas those with “variant” karyotypes had different anomalies.

Conclusion

Both, 45,X or X-chromosome variants can be detected after a high-risk cfDNA result for monosomy X. When there are fetal anomalies, the result is more likely a TP. In the absence of fetal anomalies, it is most often an FP or X-chromosome variant.     

Using the negative binomial distribution to model overdispersion in ecological count data

A Poisson process is a commonly used starting point for modeling stochastic variation of ecological count data around a theoretical expectation. However, data typically show more variation than implied by the Poisson distribution. Such overdispersion is often accounted for by using models with different assumptions about how the variance changes with the expectation. The choice of these assumptions can naturally have apparent consequences for statistical inference. We propose a parameterization of the negative binomial distribution, where two overdispersion parameters are introduced to allow for various quadratic mean-variance relationships, including the ones assumed in the most commonly used approaches. Using bird migration as an example, we present hypothetical scenarios on how overdispersion can arise due to sampling, flocking behavior or aggregation, environmental variability, or combinations of these factors. For all considered scenarios, mean-variance relationships can be appropriately described by the negative binomial distribution with two overdispersion parameters. To illustrate, we apply the model to empirical migration data with a high level of overdispersion, gaining clearly different model fits with different assumptions about mean-variance relationships. The proposed framework can be a useful approximation for modeling marginal distributions of independent count data in likelihood-based analyses.     

The missing pieces for better future predictions in subarctic ecosystems: A Torneträsk case study

Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01381-1) contains supplementary material, which is available to authorized users.     

Mechanistic insights into acetaminophen removal on cashew nut shell biomass-derived activated carbons

Environmental Science and Pollution Research - Activated carbons prepared from cashew nut shells by chemical activation with phosphoric acid were tested for the removal of acetaminophen. It was...     

放牧阉牦牛提前出栏甲烷排放强度减排潜力探讨

以阉牦牛提前出栏项目活动为例,按照2006年IPCC国家温室气体清单优良做法指南的计量方法,在同等牧草利用量的前提下,分别对4岁和7岁阉牦牛一生CH4排放总量和单位体重CH4排放量(即排放强度)进行了初步比较分析.发现在同等牧草利用量的基础上,由于饲养一头7岁阉牦牛一生所消耗的牧草量相当于可饲养2.1头4岁的阉牦牛所消耗的牧草量,所以从CH4排放总量而言,前者一生排放CH4总量比后者少86.3 kg.然而,由于后者总体重比前者重192 kg,所以,后者的单位体重CH4排放强度(以CH4/体重计)只有0.973 kg·kg-1,而前者为1.374 kg·kg-1.根据排放强度的概念,在同等牧草消耗量的基础上,如果将一头7岁阉牦牛替代成饲养2.1头4岁的阉牦牛,可以多生产192 kg的活体重,在同样生产192 kg活重的基础上,利用替代法估算后者饲养方式比前者饲养方式可以实现77 kg CH4减排量,即相当于总减排1.6 t CO2当量.因此,基于排放强度减排而不是总量减排的概念,提前出栏有较大的CH4减排潜力.     

An empirical approach to determine specific weights of driving factors for the price of commodities—A contribution to the measurement of the economic scarcity of minerals and metals

In recent years, commodity markets show a large amount of volatility and substantial price jumps, indicating an increasing economic scarcity in many cases. As this scarcity makes commodity procurement a critical issue for national economies, industry sectors and manufacturing companies, a number of criticality indices have been presented and utilized in science as well as in practice. These indices are mostly based on an aggregation of different key figures, both qualitative and quantitative. However, the weighting of the different factors is in most cases arbitrary or based on rough estimates.     

Is the convenience yield a good indicator of a commodity's supply risk?

A strong increase in the demand for some commodities over the last decade will have a major impact on their future supply situation. Of increasing importance, therefore, is an assessment of a commodity's criticality, and especially its supply risk, by appropriate indicators. The literature has proposed numerous indicators of the supply risk. Here, we use the convenience yield of commodity futures as a supply risk indicator to address some of the major shortcomings of existing indicators, especially regarding their predictive power. This paper aims to test the applicability of the convenience yield as an indicator of a commodity's future supply risk. Therefore, we calculate historical convenience yields for 3-, 15-, and 27-month futures contracts for five major industrial metals (aluminum, copper, lead, nickel, and zinc) during the period 1999 to 2011. We compare the convenience yields at the beginning of the contract period to known indicators at maturity to find that the convenience yield has generally predictive power for the static stock lifetime (i.e., inventory volume/turnover) and future spot prices. Furthermore, we find that, with some restrictions, the convenience yield is an applicable indicator of a commodity's supply risk.