Measurement of carbon storage in landfills from the biogenic carbon content of excavated waste samples

Landfills are an anaerobic ecosystem and represent the major disposal alternative for municipal solid waste (MSW) in the U.S. While some fraction of the biogenic carbon, primarily cellulose (Cel) and hemicellulose (H), is converted to carbon dioxide and methane, lignin (L) is essentially recalcitrant. The biogenic carbon that is not mineralized is stored within the landfill. This carbon storage represents a significant component of a landfill carbon balance. The fraction of biogenic carbon that is not reactive in the landfill environment and therefore stored was derived for samples of excavated waste by measurement of the total organic carbon, its biogenic fraction, and the remaining methane potential. The average biogenic carbon content of the excavated samples was 64.6 ± 18.0% (average ± standard deviation), while the average carbon storage factor was 0.09 ± 0.06 g biogenic-C stored per g dry sample or 0.66 ± 0.16 g biogenic-C stored per g biogenic C_.     

The solitary median maxillary central incisor (SMMCI) syndrome: Associations,prenatal diagnosis,and outcomes

Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder consisting of multiple, developmental defects involving midline structures of the head, which includes the cranial bones, the maxilla, and its container dentition (specifically the central incisor tooth germ), together with other midline structures of the body. SMMCI may appear as an isolated trait or in association with other midline developmental anomalies. We describe the case of a patient with SMMCI. He presented with a solitary median maxillary incisor, short stature, corpus callosum anomalies and a microform of holoprosencephaly (HPE), diabetes insipidus, and neurodevelopmental delay. The diagnosis was performed postnatally based on clinical features, radiological imaging, and a comprehensive genetic study. SMMCI can be diagnosed during the prenatal or neonatal periods or during infancy. Evaluation of the superior maxillary bone is important for prenatal diagnosis. Direct evaluation through bidimensional ultrasound or the use of multiplanar ultrasound or tridimensional reconstruction should be performed in cases of brain or face malformations. Early diagnosis can contribute to improved prenatal assessment and postnatal management.     

转Bt基因玉米种植对土壤细菌数量及多样性的影响

利用三室根箱装置获得玉米生长室土壤(S I)、根际土(SⅡ)、非根际土(SⅢ)3个不同根区土壤,采用传统平板计数培养与变性梯度凝胶电泳(DGGE)技术相结合的方法,研究了转基因玉米Btll及其非转基因亲本在播种后40、50、60 d各根区土壤细菌数量及多样性的变化.结果表明,转Bt基因玉米播种后50、60 d S I根区土壤可培养细菌数量显著低于非转基因亲本,播种后40、50 d SⅡ根区土壤可培养细菌数量较亲本玉米显著增加,而在其他时期和根区与亲本玉米之间均无显著差异.DGGE图谱显示,3个采样时期各根区DGGE图谱条带数、土壤细菌多样性指数和均匀度指数均无显著差异(P＞0.05).     

黑龙江、松花江和嫩江冰坝凌汛发生原因及预报方法

利用1951-2000年水文、气象资料,在对黑龙江、松花江、嫩江发生的特大冰坝的年份监测中分析发现,冰坝发生大多在二江同时发生,个别年份有三江同时发生,并有群发特点。冰坝发生前,秋季降水多,河槽蓄水量多,河流水位高;冬季降雪多、气温低;春季开江期,有明显的降水和升温过程,是冰坝的形成和凌汛发生的重要原因。并且分析冰坝发生前期高空环流形势特点,依此研制了冰坝凌汛预报方法。     

Packaging waste recycling in Europe: Is the industry paying for it?

This paper describes and examines the schemes established in five EU countries for the recycling of packaging waste. The changes in packaging waste management were mainly implemented since the Directive 94/62/EC on packaging and packaging waste entered into force. The analysis of the five systems allowed the authors to identify very different approaches to cope with the same problem: meet the recovery and recycling targets imposed by EU law. Packaging waste is a responsibility of the industry. However, local governments are generally in charge of waste management, particularly in countries with Green Dot schemes or similar extended producer responsibility systems. This leads to the need of establishing a system of financial transfers between the industry and the local governments (particularly regarding the extra costs involved with selective collection and sorting). Using the same methodological approach, the authors also compare the costs and benefits of recycling from the perspective of local public authorities for France, Portugal and Romania. Since the purpose of the current paper is to take note of who is paying for the incremental costs of recycling and whether the industry (i.e. the consumer) is paying for the net financial costs of packaging waste management, environmental impacts are not included in the analysis. The work carried out in this paper highlights some aspects that are prone to be improved and raises several questions that will require further research. In the three countries analyzed more closely in this paper the industry is not paying the net financial cost of packaging waste management. In fact, if the savings attained by diverting packaging waste from other treatment (e.g. landfilling) and the public subsidies to the investment on the “recycling system” are not considered, it seems that the industry should increase the financial support to local authorities (by 125% in France, 50% in Portugal and 170% in Romania). However, in France and Portugal the industry is paying local authorities more than just the incremental costs of recycling (full costs of selective collection and sorting minus the avoided costs). To provide a more definitive judgment on the fairness of the systems it will be necessary to assess the cost efficiency of waste management operators (and judge whether operators are claiming costs or eliciting “prices”).     

己烯雌酚与四溴双酚A对小球藻生长效应的影响（Effects of Diethylstilbestrol and Tetrabromobisphenol A on Growth of Chlorella pyrenoidosa）

采用化学品对藻类毒性测试的标准试验方法,分别研究了己烯雌酚和四溴双酚A单组分对小球藻生长及光合色素含量的影响,并用相加指数法评价了己烯雌酚和四溴双酚A双组分对小球藻的联合毒性效应.结果表明,藻细胞密度和光合色素含量随己烯雌酚和四溴双酚A浓度增加而明显下降,且均表现出较好的浓度-效应关系,其对小球藻的96h-EC50值分别为0.0248mg·L-1和0.0455mg·L-1;两者对小球藻96h的联合毒性效应为拮抗作用.     

Acid mine drainage attenuation by inhibition of pyrite bioleaching using limestone and olive pomace

The control and inhibition of pyrite bioleaching involved in the generation of acid mine drainage was studied. Inhibition of pyrite bioleaching was performed by varying the pyrite concentration in the medium (substrate inhibition) and/or by addition of limestone (inhibition by pH increase) and olive pomace (inhibition by organic compounds). Inhibition tests of pyrite bioleaching were performed according to a full factorial design with three factors (pyrite, limestone and olive pomace) taken at two levels. Preliminary pyrite bioleaching tests showed the ability of the available inoculum to oxidise the mineral. Subsequently, experimental data for total soluble iron denoted strong inhibition under all the different operating conditions of the factorial design, except when larger pyrite concentrations were used. In particular, inhibition by limestone was due to the increase in pH which negatively affects microorganisms, while inhibition by olive pomace may be related to the antioxidant properties of polyphenols. Interactions among operating conditions were specifically assessed by analysis of variance. Only limestone and/or pomace addition resulted in a significant (95%) diminution of iron extraction.     

Turning the game around: toxicity in a nudibranch-sponge predator–prey association

Escalation theory proposes enemy-related selection as the most relevant factor of natural selection among individual organisms. When hazardous to predators, prey might be considered enemies that influence predator evolution. Opisthobranch molluscs that prey on chemically defended prey are an interesting study case on this subject. Predation on chemically defended species paved the way for opisthobranchs to enter in an arms race, developing means to detoxify and/or excrete harmful compounds, which led to the sequestration of those compounds and their self-defensive use, an escalation of defenses. Here we aim to understand whether the opisthobranch predator is better protected than its chemically defended prey, using as predator–prey model, a nudibranch (Hypselodoris cantabrica) and the sponge it preys upon (Dysidea fragilis), and from which it obtains deterrent chemical compounds. Specimens of both species were collected on the Portuguese coast, and their crude extracts were analyzed and used in palatability tests. Nudibranchs revealed a higher natural concentration of crude extract, probably due to a progressive accumulation of the compounds. Both predator and prey extracts revealed similar mixtures of deterrent metabolites (furanosesquiterpenes). Palatability tests revealed a more effective deterrence in the nudibranch extracts because significant rejection rates were observed at lower concentrations than those necessary for the sponge extracts to have the same effect. We concluded that the predator is chemically better protected than its prey, which suggests that its acquisition of chemical defenses reveals a defensive escalation.