Are we still keeping it “real”? Proposing a revised paradigm for recycling credits in attributional life cycle assessment

Purpose

End-of-life (EoL) recycling poses a challenge to many practitioners today due to the availability of different calculation approaches and the lack of scientific consensus, which is fueled by academic research and vested industry interests alike. One of the main challenges in EoL modeling is the credible calculation of the appropriate recycling credit in open-loop and closed-loop situations.

Methods

We believe that part of the challenge is caused by a lack of understanding of the underlying recycling paradigm, which refers to the meaning that is assigned to the recycling credit. Referred to as “system expansion through substitution” and “future displacement of primary production,” the two predominant paradigms are delineated from each other followed by a discussion of their remaining challenges.

Results and discussion

Based on these considerations, we propose a revised paradigm based on embodied burdens that is able to alleviate many of the most pressing issues associated with material recycling in attributional life cycle assessment.

Conclusions

With this discussion paper, we look forward to a productive and lively debate on the matter.

     

西双版纳尚勇自然保护区野生印支虎及其三种主要有蹄类猎物种群现状调查

中国野生印支虎及其猎物种群状况的野外实地研究一直处于空白。本研究使用足迹鉴别法、粪堆计数法,首次对西双版纳尚勇自然保护区野生印支虎种群数量现状及该区域内的虎猎物种群状况进行了调查研究。结果显示:2004 ～ 2009 年间,确认西双版纳保护区存在3 只成年印支虎个体(2 雌1 雄),西双版纳尚勇保护区拥有比较丰富的有蹄类种群,其中虎的主要猎物:水鹿平均密度为7.63 (7.40 ～ 9.23)只/ km² ;赤麂平均密度为17. 39 (11.33 ～24.94)只/ km² ,野猪平均密度为10.26 (7.69 ～ 14.51) 只/ km² ,该区域虎猎物生物量为1 715. 74 kg/ km² 。本研究还探讨了该区域印支虎种群的保护前景以及中国境内开展虎种群调查的适用办法等。     

Genetic characterization of the complete genome of a highly divergent simian T-lymphotropic virus (STLV) type 3 from a wild Cercopithecus mona monkey

Background

RNA interference is a gene regulatory mechanism that employs small RNA molecules such as microRNA. Previous work has shown that HIV-1 produces TAR viral microRNA. Here we describe the effects of the HIV-1 TAR derived microRNA on cellular gene expression.

Results

Using a variation of standard techniques we have cloned and sequenced both the 5' and 3' arms of the TAR miRNA. We show that expression of the TAR microRNA protects infected cells from apoptosis and acts by down-regulating cellular genes involved in apoptosis. Specifically, the microRNA down-regulates ERCC1 and IER3, protecting the cell from apoptosis. Comparison to our cloned sequence reveals possible target sites for the TAR miRNA as well.

Conclusion

The TAR microRNA is expressed in all stages of the viral life cycle, can be detected in latently infected cells, and represents a mechanism wherein the virus extends the life of the infected cell for the purpose of increasing viral replication.     

Glutathione synthesis is essential for pollen germination in vitro

Background  

The antioxidant glutathione fulfills many important roles during plant development, growth and defense in the sporophyte, however the role of this important molecule in the gametophyte generation is largely unclear. Bioinformatic data indicate that critical control enzymes are negligibly transcribed in pollen and sperm cells. Therefore, we decided to investigate the role of glutathione synthesis for pollen germination in vitro in Arabidopsis thaliana accession Col-0 and in the glutathione deficient mutant pad2-1 and link it with glutathione status on the subcellular level.     

LCA capability roadmap—product system model description and revision

Purpose

Life cycle assessment (LCA) practitioners face many challenges in their efforts to describe, share, review, and revise their product system models, and to reproduce the models and results of others. Current life cycle inventory modeling techniques have weaknesses in the areas of describing model structure, documenting the use of proxy or non-ideal data, specifying allocation, and including modeler’s observations and assumptions—all affecting how the study is interpreted and limiting the reuse of models. Moreover, LCA software systems manage modeling information in different and sometimes non-compatible ways. Practitioners must also deal with licensing, privacy/confidentiality of data, and other issues around data access which impact how a model can be shared.

Methods

This letter was prepared by a working group of the North American Life Cycle Assessment Advisory Group to support the UNEP-SETAC Life Cycle Initiative’s Flagship Activity on Data, Methods, and Product Sustainability Information. The aim of the working group is to define a roadmap of the technical advances needed to achieve easier LCA model sharing and improve replicability of LCA results among different users in a way that is independent of the LCA software used to compute the results and does not infringe on any licensing restrictions or confidentiality requirements. This is intended to be a consensus document providing the state of the art in this area, with milestones for research and implementation needed to resolve current issues.

Results and Conclusions

The roadmap identifies fifteen milestones in three areas: “describing model contents,” “describing model structure,” and “collaborative use of models.” The milestones should support researchers and software developers in advancing practitioners’ abilities to share and review product system models.

     

A DNA vaccine against tuberculosis based on the 65 kDa heat-shock protein differentially activates human macrophages and dendritic cells

Background

Application of plasmid DNA for immunization of food-producing animals established new standards of food safety. The addition of foreign products e.g. pDNA into the food chain should be carefully examined to ensure that neither livestock animals nor consumers develop unpredicted or undesirable side-effects.

Methods

A quantitative real-time PCR (QRTPCR) methodology was developed to study the biodistribution and persistence of plasmid DNA vaccine pDNAX (pVAX-Hsp60 TM814) in mice and beef cattle. The linear quantification range and the sensitivity of the method was found to be 10 – 10⁹ copies per reaction (500 ng/gDNA) and 3 copies per reaction, respectively.

Results

Persistence of pDNAX in mice muscle tissue was restricted to injection site and the amount of pDNAX showed delivery formulation dependent (naked pDNA, electroporation, cationic liposome complexes) and mouse age-dependent clearance form injection site but pDNAX was still detectable even after 365 days. The QRTPCR analysis of various muscle tissue samples of vaccinated beef bulls performed 242–292 days after the last revaccination proved that residual pDNAX was found only in the injection site. The highest plasmid levels (up to 290 copies per reaction) were detected in the pDNAX:CDAN/DOPE group similarly to mice model. No pDNA was detected in the samples from distant muscles and draining lymph nodes.

Conclusion

Quantitative real-time PCR (QRTPCR) assay was developed to assess the residual pDNA vaccine pVAX-Hsp60 TM814 in mice and beef cattle. In beef cattle, ultra low residual level of pDNA vaccine was only found at the injection site. According to rough estimation, consumption of muscles from the injection site represents almost an undetectable intake of pDNA (400 fg/g muscle tissue) for consumers. Residual plasmid in native state will hardly be found at measurable level following further meat processing. This study brings supportive data for animal and food safety and hence for further approval of pDNA vaccine field trials.     

Serological detection of Plasmodium vivax malaria using recombinant proteins corresponding to the 19-kDa C-terminal region of the merozoite surface protein-1

BACKGROUND: Serological tests to detect antibodies specific to Plasmodium vivax could be a valuable tool for epidemiological studies, for screening blood donors in areas where the malaria is not endemic and for diagnosis of infected individuals. Because P. vivax cannot be easily obtained in vitro, ELISA assays using total or semi-purified antigens are rarely used. Based on this limitation, we tested whether recombinant proteins representing the 19 kDa C-terminal region of the merozoite surface protein-1 of P. vivax (MSP119) could be useful for serological detection of malaria infection. METHODS: Three purified recombinant proteins produced in Escherichia coli (GST-MSP119, His6-MSP119 and His6-MSP119-PADRE) and one in Pichia pastoris (yMSP119-PADRE) were compared for their ability to bind to IgG antibodies of individuals with patent P. vivax infection. The method was tested with 200 serum samples collected from individuals living in the north of Brazil in areas endemic for malaria, 53 serum samples from individuals exposed to Plasmodium falciparum infection and 177 serum samples from individuals never exposed to malaria. RESULTS: Overall, the sensitivity of the ELISA assessed with sera from naturally infected individuals was 95%. The proportion of serum samples that reacted with recombinant proteins GST-MSP119, His6-MSP119, His6-MSP119-PADRE and yMSP119-PADRE was 90%, 93.5%, 93.5% and 93.5%, respectively. The specificity values of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases were 98.3% (GST-MSP119), 97.7% (His6-MSP119 and His6-MSP119-PADRE) or 100% (yMSP119-PADRE). CONCLUSIONS: Our study demonstrated that for the Brazilian population, an ELISA using a recombinant protein of the MSP119 can be used as the basis for the development of a valuable serological assay for the detection of P. vivax malaria.     

The Synthesis In Vitro of Flagellin by a Cell-Free Extract from Bacillus Pumilus

Abstract

Bacterial flagella are constructed mainly, or perhaps exclusively, of protein subunits, the flagellins. Demonstration is given in this report for the in vitro incorporation of radioactive amino acids into flagellin, it also appears that part of such incorporation reflects de novo synthesis of flagellin moleculus. Cell-free extracts were prepared from flagellated cells of Bacillus pumilus, by digestion of the cell wall with lysozyme, lysis in the Standard buffer of NIRENBERG and MATTHAEI (1961), treatment with deoxyribonuclease and centrifugation at 15.000×g. The reaction mixtures contained the cell-free extract, one or more [¹⁴C]-amino acids and the usual components required for cell-free protein synthesis. After incubation at 37° carrier flagellin was added and the pH of the reaction mixture adjusted to 2. Flagellin, which is soluble at this pH, was purified by disc electrophoresis or by reconstitution of flagellar filament at pH 5.4 followed by electrophoresis on a column of ethanolized cellulose. When an amino acid absent from B. pumilus flagellin (such as tyrosine) was used, the amount of radioactivity incorporated into the flagellin fraction was negligible as compared to that incorporated when radioactive leucine, arginine and lysine were used. The identity of the purified radioactive protein was established more conclusively by tryptic digestion and chromatographic separation of the resulting peptides. The ninhydrin positive peaks were shown to be coincident with the radioactive peaks. The radioactive peaks disappeared when a cell-free extract from non-flagellated mutant cells was used. The incorporation of radioactive methionine in the N-terminal position of the molecule indicated that at least some of the molecules had been synthesized de novo.