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141.
Foodborne viruses, particularly human norovirus (NV) and hepatitis virus type A, are a cause of concern for public health making it necessary to explore novel and effective techniques for prevention of foodborne viral contamination, especially in minimally processed and ready-to-eat foods. This study aimed to determine the antiviral activity of a probiotic lactic acid bacterium (LAB) against feline calicivirus (FCV), a surrogate of human NV. Bacterial growth medium filtrate (BGMF) of Lactococcus lactis subsp. lactis LM0230 and its bacterial cell suspension (BCS) were evaluated separately for their antiviral activity against FCV grown in Crandell–Reese feline kidney (CRFK) cells. No significant antiviral effect was seen when CRFK cells were pre-treated with either BGMF (raw or pH 7-adjusted BGMF) or BCS. However, pre-treatment of FCV with BGMF and BCS resulted in a reduction in virus titers of 1.3 log10 tissue culture infectious dose (TCID)50 and 1.8 log10 TCID50, respectively. The highest reductions in FCV infectivity were obtained when CRFK cells were co-treated with FCV and pH 7-adjusted BGMF or with FCV and BCS (7.5 log10 TCID50 and 6.0 log10 TCID50, respectively). These preliminary results are encouraging and indicate the need for continued studies on the role of probiotics and LAB on inactivation of viruses in various types of foods.  相似文献   
142.
This study aimed to characterize raw municipal and dairy wastewaters. The quality of the collected wastewaters was determined by measuring 30 quality parameters, such as phenols, oxidation-reduction potential, oil and grease, total organic carbon (TOC), manganese, total viable count of bacteria (TVC), salinity, and biodegradability. Results were compared with wastewater disposal standards. This study also aimed to describe the potential application and performance of biological trickling filters (BTFs) in municipal and dairy wastewater treatment. Detailed reviews of trickling filter models were explained. Results revealed that two wastewater samples exceeded standard limits. The raw municipal and dairy wastewaters need treatment prior to disposal to the natural environment. Additionally, BTFs are efficient municipal and dairy wastewater treatments.  相似文献   
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144.
Earthworm response to a single cultivation sequence was assessed. Cropping and management of cultivated land was similar to that of non-cultivated areas. Effects were measured in a trial on recently replaced opencast mining land. A subsequent survey investigated responses to cultivation on both replaced and undisturbed land at periods since cultivation ranging from 1.5 to 7.5 years.On undisturbed land, adverse effects of cultivation, if any, were short-lived, with numbers of all species, but particularly deep-burrowing species, having recovered or increased after 3 years. However, on replaced land the initial adverse effect appeared to be larger, and recovery from this effect was delayed until at least 5 years after tillage. Different species present (Lumbricus terrestris/ Aporrectodea longa, Lumbricus rubellus/festivus, Aporrectodea caliginosa/Octalasion tyrtaeum and Allolobophora chlorotica) also varied in the extent of the initial reduction and in their rate of recovery. Reasons for different responses to cultivation and implications for the management of replaced land are considered.  相似文献   
145.
Quality assessment of various bottled waters marketed in Saudi Arabia   总被引:1,自引:0,他引:1  
This study focuses on the chemical analysis of the available brands of domestic bottled water in Riyadh City, Saudi Arabia. The distribution of the chemical constituents (major, minor, and trace elements) is determined and compared with the chemical content labeled on the bottles and with drinking water standards of Saudi Arabian, World Health Organization, and U.S. Environmental Protection Agency. The obtained results indicated that except for fluoride and bromate, the concentrations of dissolved salts, soluble cations and anions, nitrate, and trace elements of most bottled waters on sale were within the permissible limits set by standards used. On the other hand, the comparison between determined and reported label values recorded a substantial variation in some parameter values. Results indicated that more than 18 % of the sampled bottled waters exceeded the allowable limits for drinking water. Generated Piper diagrams revealed that the majority of investigated waters were sodium chloride–sulfate type; however, the hydrochemical modeling indicated that all water samples were undersaturated for anhydrite, gypsum, and halite.  相似文献   
146.
Valuing biodiversity: reality or mirage?   总被引:1,自引:0,他引:1  
The objective of this paper was to consider the social value ofbiological diversity and explore if this value could be expressedin terms of a unidimensional metric in money. Economics distinguishes between use-values and non-use-values, which are critically evaluated for valuing biodiversity. It is shown that these utility-based valuations have severe limitations as they treat species in isolation from their ecological contexts. In contrast, ecosystem ecology regards ecosystems as an integratednon-linear and nonconvex system in which ecosystem functions canbe understood as a four-component cycle; exploitation, accumulation of biomass, creative destruction and renewal. Withinsuch a cycle, ecosystems can be seen to have two properties: stability and resilience. A good proxy for resilience is the probability of extinction of species, and social value of biodiversity can be expressed as a partial ordering with thisprobability as an index. This approach is consistent with decision theory, of which social choice is an important component, pioneered by Arrow.  相似文献   
147.
The purpose of this study was to determine concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Nile tilapia (Oreochromis niloticus) and Bouri fish (Mugil cephalus) from Lake Qarun, a protected area of Egypt, and evaluate the relative ecological risk of these compounds. Different tissues of the fish species were analyzed for 26 chlorinated pesticides and 29 PCB congeners. Total concentrations (µg/kg wet weight, ww) of OCPs ranged between 1487 and 6217 (mean: 3260) and of PCBs between 9.0 and 61 (mean: 34). The trend of detected organochlorine pollutants was: endrin aldehyde > dieldrin > hexachlorobenzene > PCBs > endrin > 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethanes (DDTs). Heptachlor epoxide; oxy-, cis-, and trans-chlordane; trans-nonachlor; β-hexachlorocyclohexane; δ-hexachlorocyclohexane; and endosulfan I and endosulfan sulfate levels were below the detection limit. The ratios of (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylenes [DDEs] + 1,1-dichloro-2,2-bis(p-chlorophenyl)ethanes [DDDs])/ΣDDTs in fish tissues indicated no recent DDT exposure. Concentrations of DDTs and PCBs were generally comparable or higher than those found in studies of similar species worldwide. The concentrations of hexachlorobenzene, dieldrin, and endrin aldehyde in fish muscles exceeded the maximum residue level recommended by various organizations.  相似文献   
148.
Fungal pathogens, browsing mammals, birds, insects, nutrient deficiencies, drought, frost and waterlogging are all damaging agents to plantation species. The subsequent loss in leaf tissue or reduced photosynthetic potential can reduce growth and potentially lead to tree death. The Crown Damage Index (CDI) was developed in Australia to quantify damage in young eucalypt plantations. The accuracy and precision of assessing damage at a tree level were determined to ensure the reliability, objectivity and repeatability of the CDI method. Nine assessors, with varying levels of experience, estimated damage on three plots of fifty trees each, to obtain an understanding of the subjectivity of assessing damage caused by insects (e.g. Chrysophtharta spp.) and fungal pathogens (e.g. Mycosphaerella spp.) on Eucalyptus globulus. Damage levels were measured by destructive sampling to enable direct comparisons between estimates and damage levels to be made. The most experienced assessors provided the most repeatable estimates and were generally the most accurate. The incidence of foliar necrosis was the least subjective measure while defoliation was the most subjective and the least accurate of the indices measured. All assessors, regardless of experience, were able to predict the Crown Damage Index (a combined index of all damage classes) to within 12% of measured damage levels.  相似文献   
149.
We demonstrate that the non-living, dried roots of the water hyacinth plant [Eichhornia crassipes(Mart.) Solms] can rapidly remove arsenic from water. Atomic absorption spectrometry was used to demonstrate that more than 93% of arsenite (As(iii)) and 95% of arsenate (As(v)) were removed from a solution containing 200 microg As l(-1) within 60 minutes of exposure to a powder produced from dried roots. No difference in removal efficiency was observed between the two oxidation states of As studied. The amount of arsenic remaining in solution was found to be less than 10 microg l(-1) which is the WHO guideline limit value for As in drinking water. The presence of arsenic in drinking water in a number of countries in the developing world has been found to be much higher than the WHO level, affecting the health of millions of people. In this paper, we show that a biomaterial produced from dried water hyacinth roots, a plant that is found in abundant supply in many parts of the world, can provide a simple, effective and yet cheap method for removing arsenic from contaminated water.  相似文献   
150.
The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P?P?GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.  相似文献   
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