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821.
Charles U. Ugwu Yutaka Tokiwa Hideki Aoyagi 《Journal of Polymers and the Environment》2012,20(1):254-257
The feasibility of utilizing non edible rice (broken rice) for production of fine materials such as poly(3-hydroxybutyrate)
(PHB) was considered as one of the alternative ways of keeping the environment clean for sustainable development. Thus, production
of PHB from broken rice by simultaneous saccharification and fermentation (SSF) was investigated. During the SSF process,
the rice (15% w/v) material was hydrolyzed to glucose, which was utilized by Cupriavidus necator for growth and production of PHB. The PHB content reached 38% at 58 h fermentation. The PHB had weight average molar mass
(Mw) and polydipersity index of 3.82 × 105 (g/mol) and 4.15, respectively. Differential calorimetric scan of the PHB showed a melting temperature (Tm) of 176 °C. Given
that the PHB was a homopolymer (which consisted of (R)-3-hydroxybutyric acid monomers), it was thought that broken rice could be a raw material for production of both PHB and
(R)-3-hydroxybutyric acid. This SSF process would not only help in the utilization of broken rice or non edible rice, but would
also serve as a model for utilization of other raw materials that contain starch for production of PHB. 相似文献
822.
Mihriban Yılmaz Civan U. Merve Kara 《Environmental science and pollution research international》2016,23(23):23369-23384
Indoor dust samples were collected from 40 homes in Kocaeli, Turkey and were analyzed simultaneously for 14 polybrominated diphenyl ethers (PBDEs) and 16 poly aromatic hydrocarbons (PAHs) isomers. The total concentrations of PBDEs (Σ14PBDEs) ranged from 29.32 to 4790 ng g?1, with a median of 316.1 ng g?1, while the total indoor dust concentrations of 16 PAHs (Σ16PAHs) extending over three to four orders of magnitude ranged from 85.91 to 40,359 ng g?1 with a median value of 2489 ng g?1. Although deca-PBDE products (BDE-209) were the principal source of PBDEs contamination in the homes (median, 138.3 ng g?1), the correlation in the homes was indicative of similar sources for both the commercial penta and deca-PBDE formulas. The PAHs diagnostic ratios indicated that the main sources of PAHs measured in the indoor samples could be coal/biomass combustion, smoking, and cooking emissions. For children and adults, the contributions to ∑14PBDEs exposure were approximately 93 and 25 % for the ingestion of indoor dust, and 7 and 75 % for dermal contact. Exposure to ∑16PAHs through dermal contact was the dominant route for both children (90.6 %) and adults (99.7 %). For both groups, exposure by way of inhalation of indoor dust contaminated with PBDEs and PAHs was negligible. The hazard index (HI) values for BDE-47, BDE-99, BDE-153, and BDE-209 were lower than the safe limit of 1, and this result suggested that none of the population groups would be likely to experience potential health risk due to exposure to PBDEs from indoor dust in the study area. Considering only ingestion + dermal contact, the carcinogenic risk levels of both B2 PAHs and BDE-209 for adults were 6.2 × 10?5 in the US EPA safe limit range while those for children were 5.6 × 10?4 and slightly higher than the US EPA safe limit range (1 × 10?6 and 1 × 10?4). Certain precautions should be considered for children. 相似文献
823.
The levels of heavy metals (Cd, Cr, Ni, Pb, Sb and V) in Sporobulus pyramidalis plant species from an abandoned battery industry environment were determined during the wet and dry seasons as follows: The ranges in metal concentrations during the wet and dry seasons were 0.002, 0.420, 0.036 and 36.10?µg?g?1, respectively. The coefficients of variation for the metals during wet and dry seasons ranged between none to 151.724% and 13.838–214.935%, respectively. The results showed higher levels of the metals in S. pyramidalis during the dry than wet season. Results obtained from both wet and dry season when compared with background values, Federal Environmental Protection Agency and other international standards revealed that the plant species accumulated high levels of these heavy metals which was evident in concentrations exceeding maximum tolerable limits. The health implications of consuming this plant and any other plant or crop within this environment are discussed. 相似文献
824.
G. Allinson S.A. Salzman N. Turoczy M. Nishikawa U.S. Amarasinghe K.G.S. Nirbadha 《毒物与环境化学》2013,95(4):749-763
Samples of the muscle of two species of tilapia (Oreochromis mossambicus and O. niloticus; 17–20 cm length) were obtained from at least one reservoir in each of the six river basins (Aruvi Aru, Kala Oya, Kirindi Oya, Ma Oya, Mahaweli, and Walawe Ganga catchments) in Sri Lanka. The metals Ca, Cu, Fe, K, Mg, Mn, Na, and Zn were consistently detected in the muscle tissue. Overall, there were few differences in the concentration of metals between the two species of fish, although there were also some statistically significant differences (p < 0.05) in the concentrations of some metals in fish obtained from some of the reservoirs. Aruvi Aru stands out as a river basin in which the two fish species have significantly lower concentration of metals when compared to other river basins. The concentration of the metals studied were below WHO and FSANZ guideline values for fish, suggesting that the consumption of the metals found in tilapia from these reservoirs poses little risk to human health. 相似文献
825.
Zacharia J. U. Malley Johnson M. R Semoka Josephat A. Kamasho Catherine V. Kabungo 《国际发展与全球生态学杂志》2013,20(3):183-197
Rural household food insecurity and poverty are closely linked to soil degradation in Sub-Saharan Africa. However, causes, degradation processes, coping strategies and need for interventions may vary from one place to another. This study was conducted in Mbinga District, SW Tanzania, to investigate causes and biophysical processes of soil degradation; effects on livelihoods, coping strategies and entry points for interventions. Implications for sustainable production and rural livelihoods are discussed. Participatory Rural Appraisal (PRA), household surveys using a short open-ended questionnaire and biophysical exploration were the research tools used. Soil fertility depletion resulting from continuous cropping and erosion losses is the main form of soil degradation. Maize yield was 57% lower in fertility-depleted farms than in productive farms. Soil pH, Ca2+, Mg2+ and CEC accounted for 79% of variations in maize yield. Organic soil fertility amelioration was a common strategy used by smallholders. Use of beneficial tree and shrub fallows is the most environmentally, economically and socially promising improvement that can be used to build on the existing strengths of farmers' knowledge and strategies. Subsidy for the right type of fertilizers, infrastructure improvement and education of farmers on proper use of fertilizers should significantly contribute to improved and sustainable production and livelihoods. 相似文献
826.
SUMMARY Biodiversity of a protected area of West Himalaya (Askot Wildlife Sanctuary) was studied and analysed for landscape, faunal and floral diversity. The forest and pasture land, ideal habitats for the flora and fauna, covered nearly 52% and 12%, respectively, of total reported area. Among the fauna Himalayan musk deer (Moschus chrysogaster), thar (Himitragus jemlahicus), snow leopard (Panthera uncia), koklas (Pucrassia macrolophas), monal (Lophophorus impejanus) and snow cock (Tetragalus tibetanus) are threatened species. Plant diversity is represented by 1262 species of vascular plants (Angiosperm 1112, Gymnosperm 7, Pteridophytes 143 taxa). Diversity of the species within families, genera, habitats, communities and along vertical gradient zone was analysed. Maximum diversity existed in the family Orchidaceae (120 taxa), genera Polystichum (13 taxa), altitude zone (1001–2000 m; 860 taxa), habitat (forest; 623 taxa) and community (Banj oak: 92 taxa). Seventy-one families were found to be monotypic. Species were further analysed for ethnobotanical use (medicine: 70, edible: 55, fodder: 115, fuel: 31, house building: 13 etc.), domesticated diversity (crops: 19, vegetables: 26, fruits: 16), agroforestry or marginal, threatened and endemic diversity. Similarity in species composition within the habitats indicated maximum similarity in areas of shrubberies and alpine meadows/ slopes (71.65%) and exposed open/grassy slopes and shady moist places (47.32%). 432 (34.2%) taxa are native to Indian Himalaya of which 24 are endemic and 235 are near endemics. 65.8% of taxa are represented in the neighbouring areas and other regions of the globe. Ten taxa occurring in the Sanctuary have been already recorded in the Red Data Book of Indian Plants. Conservation and management of species is focused. 相似文献
827.
Silvan U. Goldenberg Jost Borcherding Martina Heynen 《Behavioral ecology and sociobiology》2014,68(6):989-998
Group size, predation risk and habituation are key drivers of behaviour and evolution in gregarious prey animals. However, the extent to which they interact in shaping behaviour is only partially understood. We analyzed their combined effects on boldness and vigilance behaviour in juvenile perch (Perca fluviatilis) by observing individuals in groups of one, two, three and five faced with four different levels of predation risk in a repeated measures design. The perch showed an asymptotic increase in boldness with increasing group size and the highest per capita vigilance in groups of two. With increasing predation risk, individuals reduced boldness and intensified vigilance. The interaction between group size and predation risk influenced vigilance but not boldness. In this context, individuals in groups of two elevated their vigilance compared to individuals in larger groups only when at higher risk of predation. Further, as only group size, they significantly reduced vigilance at the highest level of risk. With increasing habituation, solitary individuals became considerably bolder. Also, predation risk affected boldness only in the more habituated situation. Hence, repeated measures may be essential to correctly interpret certain relationships in behaviour. Our results suggest that perch may adjust boldness behaviour to group size and predation risk independently. This is rather unexpected since in theory, natural selection would strongly favour an interactive adjustment. Finally, vigilance might be particularly effective in groups of two due to the intense monitoring and detailed response to changing levels of risk. 相似文献
828.
Environmental Geochemistry and Health - Acacia albida, Acacia luederitzii, and Acacia tortilis are dominant acacia species in Botswana and have the potential to rehabilitate the heavy metal... 相似文献
829.
Eltayeb Mohanad Li SanXi Okoye Patrick U. Wang Song 《Journal of Polymers and the Environment》2021,29(6):1880-1893
Journal of Polymers and the Environment - The cyclic carbonates as non-isocyanate polyurethane (NIPU) precursors are usually prepared via CO2 fixation under harsh conditions for a satisfactory... 相似文献
830.
Sources of organic matter (OM) in lower Narmada and Tapi river-estuaries were examined using organic carbon to nitrogen ratio (Corg/N), stable carbon isotope ratio (δ13Corg) and lignin phenol biomarkers. The signature of lower Corg (av. 0.50%) and higher δ13Corg (av. –20.3‰) in Narmada and, higher Corg (av. 0.85%) and lower δ13Corg (av. –22.8‰) in Tapi highlight the difference in OM characteristics of both systems, nevertheless they flow adjacent to each other. The OM in Tapi was predominated by fresh plant tissues, as indicated by higher Λ8?=?1.2–3.2?mg/100?mg Corg, lower Ad/Alv?=?0.22–0.46 and lower LPVI?=?17–23. The plant OM present in the sediments of Narmada was previously degraded and mixed with soil. The OM contribution from algae was restricted to estuarine stations in both the rivers, which was ~50% in Narmada and ~35% in Tapi. The contribution of OM from fresh vascular plant was higher (20% to 63%) in Tapi than Narmada (2% to 35%). This study illustrated the benefits of using lignin phenols along with Corg/N and δ13Corg to identify the potential OM sources in two large river–estuary systems of India, which highlighted the complex interaction of natural and anthropogenic processes acted on the terrestrial OM compositions. 相似文献