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61.
Environmental Science and Pollution Research - The evaluation of the toxicological effects of titanium dioxide nanoparticles (TiO2NPs) is increasingly important due to their growing occupational...  相似文献   
62.
The switch from hunting wild meat for home consumption to supplying more lucrative city markets in Amazonia can adversely affect some game species. Despite this, information on the amounts of wild meat eaten in Amazonian cities is still limited. We estimated wild meat consumption rates in 5 cities in the State of Amazonas in Brazil through 1046 door-to-door household interviews conducted from 2004 to 2012. With these data, we modeled the relationship between wild meat use and a selection of socioeconomic indices. We then scaled up our model to determine the amounts of wild meat likely to be consumed annually in the 62 urban centers in central Amazonia. A total of 80.3% of all interviewees reported consuming wild meat during an average of 29.3 (CI 11.6) days per year. Most wild meat was reported as bought in local markets (80.1%) or hunted by a family member (14.9%). Twenty-one taxa were cited as consumed, mostly mammals (71.6%), followed by reptiles (23.2%) and then birds (5.2%). The declared frequency of wild meat consumption was positively correlated with the proportion of rural population as well as with the per capita gross domestic product of the municipality (administrative divisions) where the cities were seated. We estimated that as much as 10,691 t of wild meat might be consumed annually in the 62 urban centers within central Amazonia, the equivalent of 6.49 kg per person per year. In monetary terms, this amounts to US$21.72 per person per year or US$35.1 million overall, the latter figure is comparable to fish and timber production in the region. Given this magnitude of wild meat trade in central Amazonia, it is fundamental to integrate this activity into the formal economy and actively develop policies that allow the trade of more resilient taxa and restrict trade in species sensitive to hunting.  相似文献   
63.
The aim of this paper was to study the effects of reinforcing low density polyethylene (LDPE) by using bio-fillers (Doum cellulose or Shrimp chitin) on the mechanical properties. Both, Doum cellulose extracted frsom Doum leaves and Shrimp chitin extracted from shrimp co-products were compounded with LPDE without and with compatibilizer. The biocomposites were prepared by melt blending in a twin-screw extruder. Torsion and flexural tests were performed to investigate the impact of each reinforcement on the biocomposite mechanical properties. The SEM was carried out to study the filler/polymer interface adhesion. The present study has demonstrated that Doum fibers and shrimp chitin succeed in improving the mechanical properties of LPDE bio-composites. The results also showed that the use of maleic anhydride-grafted polyethylene as a compatibilizer improves filler adhesion/matrix and mechanical properties. This study exhibits that polyethylene composites based on Doum fibers or shrimp chitin can be used to replace the polyethylene materials in several fields like packaging and automotive industries.  相似文献   
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Two species of the green alga genusCaulerpa are considered as invasive in Tunisia:Caulerpa racemosa andC. taxifolia. C. racemosa is found in a many new localities at the central and southern Tunisian coast, and even in the North of the country in colder water. These new observations lead to the hypothesis of the multiplicity of the origins of the introduction of the species and suggest possible invasive potentialities. The general thallus, and more particularly the number, the shape as well as the arrangement of ramelli on fronds allowed us to identify four morphologically different groups. These groups could be either different systematic entities or polymorphic variations of the same taxon due to different ecological conditions.Caulerpa taxifolia was observed for the first time in Tunisia at the roadstead of Sousse in the beginning of the year 2000. It is recognized as identical to that found in the other Mediterranean localities (GenBank number AJ228960). Up to the end of March 2000, a submarine prospecting campaign revealed an affected area of about 350 ha in front of 2 km of coast. Colonies ofCaulerpa taxifolia disseminating in this area appear in isolated spots. form, In the growing stage, they form surfaces varying between 0.5 to 6 m2 and located 20 to 100 m from each other. The total covered surface was estimated to be between 0.5 and 1 ha.  相似文献   
67.
The residues of 17 organochlorine pollutants were analyzed in bivalve Brachiodontes sp. collected from 11 different locations in April 2000 along the Egyptian Red Sea coast. The pollutants studied were 10 individual polychlorinated biphenyl (PCB) congeners, alpha,alpha,alpha-hexachlorocyclohexane (HCHs), cyclodienes (heptachlor, heptachlorepoxide, aldrin, dieldrin) and dichlorodiphenyltrichloroethanes (DDTs) (p,p'-DDE, p,p'-DDD and p,p'-DDT). The concentration of total DDTs ranged between 125 and 772 ng/g of wet weight whereas the concentration of the PCBs, HCHs and cyclodienes ranged from 6.7 to 66.4 ng/g; 16.2 to 183.4 ng/g and 8.8 to 221.6 ng/g of wet weight, respectively. The levels are low to moderate in relation to the published data from other coastal areas. The present results indicate low to moderate PCBs and pesticides contamination in the investigated mussels except DDTs.  相似文献   
68.

Marine algae have made a strong contribution to global food security in the future. This study is the first report describing the concentration, pathways, and interactions of halogens in 15 species of marine algae collected from the Eastern Harbor in Alexandria, Egypt, relative to 22 key variables. The relationship between halogen content and chemical and biochemical parameters was studied through multivariate analysis. Among all the tested algae, the iodine content was the lowest (2.53–3.00 μg/g). The range of fluoride and chloride in macroalgae (1.12–1.70 and 0.10–0.46 mg/g) was smaller than that of microalgae (0.10–0.46 and 1.48–3.17 mg/g). The bromide content in macroalgae (0.36–5.45 mg/g) was higher than that in microalgae (0.40–0.76 mg/g). The halogen content in macroalgae was arranged in the order of Br > F > Cl > I. In addition, the biochemical parameters such as carbohydrates, proteins, lipids, and certain heavy metals (Fe, Zn, Cu, Mn, Pb, Ni, Co, Cd, and Cr) were determined. Calories, energy, total antioxidant activity (TAC), K/Na, and ion quotient amounts were estimated. The results showed that the green seaweed species had the highest TAC content. In most of the studied algal species, the calculated ion quotient referred to their likelihood of overcoming high blood pressure. The estimated daily intake (EDI) of algae showed no adverse effects on human health. Most of the research variables are below the acceptable WHO/FAO level. Generally, the calorie content of the selected algae is less than 2 kcal, which makes the algae considered an alternative source of healthy food to reduce obesity.

Graphical abstract

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69.
The levels of several different persistent organochlorines (OCs) in Black Guillemots Cepphus grylle, collected during the summers of 1976-1996 at Breioafj?rour in W-Iceland, were investigated. The levels of about 40 different organochlorines (PCBs, DDTs, chlordanes, toxaphenes, HCH, HCB) were compared with respect to age, sex, fat content, and year of collection. The levels of PCBs correlated very closely with those of DDE, indicating long-range transport as the major source of these contaminants in Iceland, with the ratio PCBs/DDE mostly in the range of 2-5. Unlike the Gyrfalcon Falco rusticolus, the organochlorine levels did not seem to accumulate substantially with age, neither in males nor females. The variation in the levels of OCs at the age of 2 years was even greater than the variation in OC levels over an age range of 12 years. In immature birds the levels of PCBs, DDE, HCB and beta-HCH declined very slowly (T(1/2) from 12 to 20 years) over the years 1976-1996, whereas the levels of alpha-HCH and p,p'-DDT declined much faster. The levels of trans-nonachlor, alpha-chlordane, gamma-chlordane, oxychlordane, and toxaphene did not correlate with the year of collection. As the Black Guillemot is mostly a resident seabird, feeding mainly on small fish and invertebrates, this investigation should give a good indication of the temporal trends of organochlorine pollution at Breioafj?rour, Iceland, during this 20 year period and is likely to reflect baseline trends in the marine environment of the North-Atlantic Ocean.  相似文献   
70.
Zinc adsorption equilibria were measured in soils differing in pH but with similar textures and total zinc concentrations, using adsorption isotherm and isotopic exchange techniques. The results suggested that the equilibrium between solution and exchangeable zinc was strongly pH dependent and the active zinc species in adsorption was single charged (e.g. Zn(OH)(+)). The size of the exchangeable zinc pool was not strongly pH dependent. Similar results were obtained when zinc was added to the soils, either as Zn(NO(3))(2) or in sewage sludge.  相似文献   
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