Chemical composition and antimicrobial activities of the essential oil from the seeds of Enterolobium contortisiliquum (leguminosae)

Seeds of Enterolobium contortisiliquum were subjected to steam distillation to obtain a light yellow essential oil in a yield of 3 ml/kg of seeds. The major components of the oil were identified using gas chromatography/mass spectrometry (GC-MS) and were furfural, limonene, linalool, estragole, carvone, and apiole with carvone representing more than 50% of the total composition. Antimicrobial activities of the essential oil were determined against four species of gram positive bacteria (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus) and two gram negative bacteria (Klebsiella pneumoniae, Serratia Marcescencs). The essential oil inhibited the growth of all tested bacteria but was most effective against the gram positive bacteria. Chemicals that are responsible for the antibacterial effect of the essential oil were determined using the bio-autography thin layer chromatography (TLC) technique. The active compounds responsible for the activity were found to be carvone and estragole.     

Nematicidal activity of terpenoids

Thirty four phytoterpenoids were evaluated for their nematicidal effect using the model nematode Caenorhabditis elegans. Nematicidal activities of the tested compounds at concentrations of 50 μg/mL showed wide variation in their effects ranging from no effect, weak, moderate and strong effects. Terpenoids exerting 50% or higher mortality at 50 μg/mL were further tested at five different concentrations to calculate the concentration that will kill 50% of the nematode population (LC₅₀). Among the most effective terpenoids were carvacrol, thymol, nerolidol, α-terpinene, geraniol, citronellol, farnesol, limonene, pseudoionone and eugenol in a descending order. These compounds exhibited a dose-dependent effect. The results suggest that the selected monoterpenoids and essential oils with a high concentration of these compounds mayprovide potential natural nematicides and merit further study as botanical nematicides for the control of both plant and animal parasitic nematodes. In general, oxygenated terpenoids and phenolic terpenoids exhibited higher nematicidal activity than hydrocarbons terpenoids.     

Flow photocatalysis system-based functionalized graphene oxide-ZnO nanoflowers for degradation of a natural humic acid

Environmental Science and Pollution Research - The functionalized graphene oxide-ZnO (fGO/ZnO) nanoflower composites have been studied as a photocatalyst material for flow photodegradation of humic...     

Safety in the mining industry and the unfinished legacy of mining accidents: Safety levers and defense-in-depth for addressing mining hazards

Mining remains one of the most hazardous occupations worldwide and underground coal mines are especially notorious for their high accident rates. In this work, we provide an overview of the broad and multi-faceted topic of safety in the mining industry. After reviewing some statistics of mining accidents in the United States, we focus on one pervasive and deadly failure mode in mines, namely explosions. The repeated occurrence of mine explosions, often in similar manner, is the loud unfinished legacy of mining accidents and their occurrence in the 21st century is inexcusable and should constitute a strong call for action for all stakeholders in this industry to settle this problem. We analyze one such recent mine disaster in which deficiencies in various safety barriers failed to prevent the accident initiating event from occurring, then subsequent lines of defense failed to block this accident scenario from unfolding and to mitigate its consequences. We identify the technical, organizational, and regulatory deficiencies that failed to prevent the escalation of the mine hazards into an accident, and the accident into a “disaster”. This case study provides an opportunity to illustrate several concepts that help describe the phenomenology of accidents, such as initiating events, precursor or lead indicator, and accident pathogen. Next, we introduce the safety principle of defense-in-depth, which is the basis for regulations and risk-informed decisions by the US Nuclear Regulatory Commission, and we examine its relevance and applicability to the mining system in support of accident prevention and coordinating actions on all the safety levers, technical, organizational, and regulatory to improve mining safety. The mining system includes the physical confines and characteristics of the mine, the equipment in the mine, the individuals and the organization that operate the mine, as well as the processes and regulatory constraints under which the mine operates. We conclude this article with the proposition for the establishment of defense-in-depth as the guiding safety principle for the mining industry and we indicate possible benefits for adopting this structured hazard-centric system approach to mining safety.     

Pharmacological implications of ipriflavone against environmental metal–induced neurodegeneration and dementia in rats

Environmental Science and Pollution Research - Long-term exposure to environmental neurotoxic metals is implicated in the induction of dementia and cognitive decline. The present study aims to...     

Advantages and prospective challenges of nanotechnology applications in fish cultures: a comparative review

Environmental Science and Pollution Research - Applications of nanotechnology in fish cultures have participated in getting over various difficulties that hinder fish productivity. They can achieve...     

Organochlorine insecticide residues in Egyptian mothers’ milk

Two hundred ninety‐two mother's milk samples were collected during 1994 from ten Egyptian governorates representing rural, metropolitan, and newly reclaimed desert areas. The samples were analyzed for 14 organochlorine insecticides and metabolites using electron capture gas chromatography and confirmed by gas chromatography/mass spectrometry (GC/MS). The overall samples average showed that the most abundant organochlorine insecticide residues were p,p'‐DDE, α‐endosulfan, β‐HCH and, p,p’‐DDT. Residues in the range of not detectable to less than 14μg/l whole milk were recorded for α‐HCH, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin endrin aldehyde and p,p'‐DDD. The percentage of samples exceeding the acceptable daily intake for children (ADIs) set by the FAO/WHO ranged from 19% to 44% in all governorates included in the study except the governorate of Minia in which only 2.6% of the samples exceeded the ADI values. The insecticides exceeding ADI values are mostly heptachlor and heptaclor epoxide (ADI = 3.12 μg/1 whole milk).     

How green our future would be? An investigation of the determinants of green purchasing behavior of young citizens in a developing Country

Environment, Development and Sustainability - Research on green purchasing behavior (GPB) has demonstrated significant progress in the past few years. However, there are still several influential...     

Environmental planning and management for the Assarawat highland region of south-western Saudi Arabia: the traditional versus the professional approach

The environmental planning and management of the Assarawat highlands of south-western Saudi Arabia are currently confronted by difficult problems. Deforestation is caused either by natural or intentional forces. Natural factors are limited to lightning fire and drought, while intentional forces include vandalism caused by the burning or cutting of preserved forests. Such vandalism continues despite the tremendous efforts of afforestation and preservation by several government agencies, especially the Ministry of Agriculture and Water, the National Commission for Wildlife Conservation and Development and by the municipalities of the cities and towns in the region. For centuries, local inhabitants of the Assarawat highlands have successfully established environmental planning and management strategies which balanced the settlements' growth and natural resource uses according to Islamic laws, and the tribal self-government of each settlement and tribal region. Following the establishment of the Kingdom of Saudi Arabia in 1932, the land management system started to change from tribal-based, where every tribe used to manage its local territory, to State authority. The creation of the State witnessed the unification of various fragmented tribes of Saudi Arabia into one government. This meant that environmental planning and management moved from local/regional towards a national control. This investigation proposes that the local/regional planning and management practised by the tribes could be viably utilized today. As in the past, the implementation of these practices could protect the natural environment of the locality and region and regularize their exploitation rationally, as long as vernacular people implement them. Today environmental planning and management need to be based on strategies of local requirements that enable the indigenous people to plan and manage the use of the resources.     

Seasonal and spatial trends in the sources of fine particle organic carbon in Israel,Jordan, and Palestine

A study of carbonaceous particulate matter (PM) was conducted in the Middle East at sites in Israel, Jordan, and Palestine. The sources and seasonal variation of organic carbon, as well as the contribution to fine aerosol (PM_2.5) mass, were determined. Of the 11 sites studied, Nablus had the highest contribution of organic carbon (OC), 29%, and elemental carbon (EC), 19%, to total PM_2.5 mass. The lowest concentrations of PM_2.5 mass, OC, and EC were measured at southern desert sites, located in Aqaba, Eilat, and Rachma. The OC contribution to PM_2.5 mass at these sites ranged between 9.4% and 16%, with mean annual PM_2.5 mass concentrations ranging from 21 to 25 ug m^?3. These sites were also observed to have the highest OC to EC ratios (4.1–5.0), indicative of smaller contributions from primary combustion sources and/or a higher contribution of secondary organic aerosol. Biomass burning and vehicular emissions were found to be important sources of carbonaceous PM in this region at the non-southern desert sites, which together accounted for 30%–55% of the fine particle organic carbon at these sites. The fraction of measured OC unapportioned to primary sources (1.4 μgC m^?3 to 4.9 μgC m^?3; 30%–74%), which has been shown to be largely from secondary organic aerosol, is relatively constant at the sites examined in this study. This suggests that secondary organic aerosol is important in the Middle East during all seasons of the year.