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71.
72.
Tourism can sustain high levels of employment and income, but the sector is a source of environmental and health impacts. One of the most important is the generation of municipal solid waste (MSW). However, there is a lack of studies which quantify how much the tourist population engages in total MSW and separately collected recyclables. The aim of this paper is to estimate the impact of the tourist population on MSW, both total and separately collected, for the period 1998–2010, for the Mediterranean island of Menorca (Spain). We use dynamic regressions models, including data for monthly stocks of tourists. The results show that, on average, a 1% increase in the tourist population in Menorca causes an overall MSW increase of 0.282% and one more tourist in Menorca generates 1.31 kg day?1 (while one more resident generates 1.48 kg day?1). This result could be useful to better estimate the seasonal population of different regions, since intrannual fluctuation of MSW is used as a proxy measure of actual population (the sum of residents and tourists). Moreover, an increase of 1% in the tourist population causes an increase of 0.232% in separately collected recyclables and an additional tourist generates 0.160 kg day?1. One resident selectively collects on average 47.3% more than one tourist. These results can help in the planning of waste infrastructure and waste collection services in tourist areas.  相似文献   
73.
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation’s economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling.  相似文献   
74.
Samples of Jerusalem limestones were exposed to high levels of common air pollutants (SO2, NO) in the presence and absence of hydrocarbon, water vapor and ultra-violet light. After exposure, the outer layers were shaved off and analyzed for sulfate and nitrate. The results revealed that even after one day of exposure significant concentrations of CaSO4 and Ca(NO3)2 could be detected in the external 40 m layers. Sulfate formation was found to relate very strongly to relative humidity with nearly undetectable production at humidities below 10%. Nitrate formation was found to relate to UV light and to a limited extent to the presence of hydrocarbon but was unchanged at different humidities. Surface samples were taken from different sites of the old city wall and were also analyzed for the same substances. The data showed that the concentrations of especially CaSO4, and to a limited extend Ca(NO3)2, measured at various points along the city walls were higher than the expected values extrapolated from laboratory simulations. The elevated pollution content may be explained in part due to the deposition of transported ions, especially sulfate, onto the stone surface. It was concluded that although air pollution may not cause any structural damage in the foreseeable future it definitely deteriorates the fine details of the ancient monument.  相似文献   
75.
This study was undertaken to evaluate the degradation and mobility of the herbicide tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N'-dimethylurea) in soil under field conditions, and its potential for leaching and groundwater contamination. A watershed, Espraiado, located over a recharge area in Brazil, was chosen for soil and water studies. At Espraiado, water samples were collected from seven wells at intervals of three months from March 2004 to June 2006 and analyzed for tebuthiuron. Other samples were taken from city wells located outside of the recharge area. To assess the potential movement to the aquifer, tebuthiuron was also applied to trial plots at the recommended label rate of 1.0 kg/ha a.i. in May of 2004, with and without sugarcane coverage, on sandy soil. Soil samples were collected during the years of 2004 and 2005, at depths intervals of 20 cm from soil surface down to 120 cm and analyzed for tebuthiuron at zero, 3, 30, 60, 90, 120, 150, 180, 240, and 300 days after application. There was no clear effect of sugarcane coverage on the tebuthiuron degradation in soils, but it moved faster into the soil where there was no cover. After 180 days there were no measurable residues in the soil, and tebuthiuron was not found below 40 cm depth in any time. Tebuthiuron had a half-life of 20 days under those conditions. No tebuthiuron residue was found in ground water samples at any sampling time.  相似文献   
76.

The Placerias/Downs’ Quarry complex in eastern Arizona, USA, is the most diverse Upper Triassic vertebrate locality known. We report a new short-faced archosauriform, Syntomiprosopus sucherorum gen. et sp. nov., represented by four incomplete mandibles, that expands that diversity with a morphology unique among Late Triassic archosauriforms. The most distinctive feature of Syntomiprosopus gen. nov. is its anteroposteriorly short, robust mandible with 3–4 anterior, a larger caniniform, and 1–3 “postcanine” alveoli. The size and shape of the alveoli and the preserved tips of replacement teeth preclude assignment to any taxon known only from teeth. Additional autapomorphies of S. sucherorum gen. et sp. nov. include a large fossa associated with the mandibular fenestra, an interdigitating suture of the surangular with the dentary, fine texture ornamenting the medial surface of the splenial, and a surangular ridge that completes a 90° arc. The external surfaces of the mandibles bear shallow, densely packed, irregular, fine pits and narrow, arcuate grooves. This combination of character states allows an archosauriform assignment; however, an associated and similarly sized braincase indicates that Syntomiprosopus n. gen. may represent previously unsampled disparity in early-diverging crocodylomorphs. The Placerias Quarry is Adamanian (Norian, maximum depositional age ~219 Ma), and this specimen appears to be an early example of shortening of the skull, which occurs later in diverse archosaur lineages, including the Late Cretaceous crocodyliform Simosuchus. This is another case where Triassic archosauriforms occupied morphospace converged upon by other archosaurs later in the Mesozoic and further demonstrates that even well-sampled localities can yield new taxa.

  相似文献   
77.
Transgenic glyphosate-resistant soybeans (GRS) have been commercialized and grown extensively in the Western Hemisphere, including Brazil. Worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when GRS are adopted. In the USA and Argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practices, thereby significantly reducing environmental degradation by agriculture. Similar shifts in tillage practiced with GRS might be expected in Brazil. Transgenes encoding glyphosate resistance in soybeans are highly unlikely to be a risk to wild plant species in Brazil. Soybean is almost completely self-pollinated and is a non-native species in Brazil, without wild relatives, making introgression of transgenes from GRS virtually impossible. Probably the highest agricultural risk in adopting GRS in Brazil is related to weed resistance. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. These include Chamaesyce hirta (erva-de-Santa-Luzia), Commelina benghalensis (trapoeraba), Spermacoce latifolia (erva-quente), Richardia brasiliensis (poaia-branca), and Ipomoea spp. (corda-de-viola). Four weed species, Conyza bonariensis, Conyza Canadensis (buva), Lolium multiflorum (azevem), and Euphorbia heterophylla (amendoim bravo), have evolved resistance to glyphosate in GRS in Brazil and have great potential to become problems.  相似文献   
78.
The reactivity of paclobutrazol (PBZ, a plant growth retardant) with a Yellow Ultisol and a Vertisol from the semiarid northeast region of Brazil was evaluated through batch sorption experiments and modeling. Although not instantaneous, the sorption kinetic of PBZ (pure and formulated) was fast (a few hours) in both soils. The sorption kinetics were well described by a second-order (dS(t)/dt=k(2)(S(e2)-S(t))(2)) but not by a first-order model. The sorption isotherms were found to be linear and the calculated K(D) values were 8.8 +/- 0.11 and 7.4 +/- 0.2 L kg(-1) for pure PBZ in the Ultisol and the Vertisol, respectively. The corresponding K(OC) values were 1275 +/- 34 (logK(OC) = 3.11) and 1156 +/- 49 (logK(OC) = 3.06) L kg(-1), respectively. Considering the very different texture of the two soils and the similar K(OC) values determined, these results showed that in both soils, the sorption of PBZ is dominantly controlled by organic matter, although some interactions of PBZ with iron oxides (goethite) were observed in the Ultisol. Based on these sorption parameters a low leachability potential of PBZ in soils is anticipated, as they correspond to a groundwater ubiquity score (GUS) ranging from 2.0 to 2.7, i.e., moderately to not mobile, in contradiction with the actual groundwater situation in Brazil. This work stresses the need to evaluate and predict the risk associated with aquifer contamination by this widely used plant growth regulator.  相似文献   
79.
Nest and territory defence are risky and potentially dangerous behaviours. If the resolution of life history trade-offs differs between individuals, the level of defence may also vary among individuals. Because melanin-based colour traits can be associated with life history strategies, differently coloured individuals may display different nest and territory defence strategies. We investigated this issue in the colour polymorphic tawny owl (Strix aluco) for which plumage varies from dark to light reddish melanic. Accordingly, we found that (1) our presence induced a greater response (flying around) from dark-coloured than light-coloured females and (2) dark reddish males suffered lower nest predation rates than light-coloured males. In experimentally enlarged broods, the probability that females reacted after we played back the hoot calls of a stranger male was higher if these females were lighter reddish; the opposite pattern was found in experimentally reduced broods with dark parents being more reactive than light parents. Finally, darker females alarmed more frequently when paired with a light than with a dark male, suggesting that partners adjust their behaviour to each other. We also tested whether colouration is used as a signal by conspecifics to adjust the level of their defensive behaviour. Accordingly, breeding females responded more vigorously to a dark than a light reddish stuffed tawny owl placed beside their nest. We conclude that melanin-based colouration is a signal of alternative nest and territory defence behaviour that depends on ecological factors.  相似文献   
80.
Environmental Science and Pollution Research - Improper disposal of animal waste is responsible for several environmental problems, causing eutrophication of lakes and rivers, nutrient overload in...  相似文献   
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