Development,larvicide activity,and toxicity in nontarget species of the Croton linearis Jacq essential oil nanoemulsion

Environmental Science and Pollution Research - In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic...     

Life-cycle greenhouse gas emissions and economic analysis of alternative treatments of solid waste from city markets in Vietnam

We utilize life cycle assessment to trace conversion of degradable organic carbon (DOC) contained in organic waste from city markets in Da Nang, Vietnam. Our methodology makes explicit the process of conversion of DOC under aerobic and anaerobic conditions, as well as the balance of nutrients. Greenhouse gas emissions were calculated for six alternative scenarios: (i) anaerobic landfilling (current situation); (ii) semi-aerobic landfilling; (iii) landfill gas capture; (iv) composting; (v) pre-composting before landfill; and (vi) biogas production. We calculate that 1 t of waste in anaerobic landfilling emits 1.70 t CO₂-eq. with life-cycle perspective. Lowest emission occurs in biogas scenario with 0.26 t CO₂-eq./t. Composting occupies an intermediate position with 0.39 t CO₂-eq./t. Likewise, we estimate that cost of emission reduction in solid waste sector of Vietnam is 15.13 US$/t CO₂-eq., given by alternative of composting and taking anaerobic landfilling as reference. On the other hand, if social cost of carbon (SCC) is incorporated lowest cost to treat 1 t of waste is given by composting and semi-aerobic landfilling at discount rate of 5 %. However, using lower discount rates, and consequently higher values of SCC, composting and biogas production become the alternatives with lowest treatment costs.     

Utilization of yolk reserves during post-embryonic development in three teleostean species: the sea bream Sparus aurata,the sea bass Dicentrarchus labrax,and the pike-perch Stizostedion lucioperca

A comparative study of the use of yolk reserves during post-embryonic development was performed on three teleostean fishes of aquacultural interest: the sea bream Sparus aurata, the sea bass Dicentrarchus labrax, and the pike-perch Stizostedion lucioperca. The first part of the work was devoted to the structural development of the periblast, the vitellus and the oil globule during the endotrophic and endo-exotrophic phases of larval life. Observations using transmission electron microscopy revealed a perivitelline circulation system closely related to the liver, and suggested an important function of the periblast in the utilization of reserves. In the second part of the study, cytochemical reactions revealed the way in which the reserves are resorbed. Glycogen contained in the periblast at hatching was utilized during the endotrophic period. The successive appearance of lipoprotein particles in the periblast endoplasmic reticulum, Golgi apparatus, and perivetelline circulation zone is consistent with the mobilization of yolk and oil globule components. Comparison of fed and fasting individuals revealed that fasting tended to slow down rather than increase the utilization of reserves.