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121.
Raquel G. Loreto Adam G. Hart Thairine M. Pereira Mayara L. R. Freitas David P. Hughes Simon L. Elliot 《Die Naturwissenschaften》2013,100(10):957-963
Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants (Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration. 相似文献
122.
Nogueira L Rodrigues AC Trídico CP Fossa CE de Almeida EA 《Environmental monitoring and assessment》2011,180(1-4):243-255
Considering that diesel oil is one of the most common aquatic contaminants, we compare the oxidative stress between two species of fish with different habitats (Pterygoplichthys anisitsi, benthic and Oreochromis niloticus, nektonic) exposed to diesel oil. Malondialdehyde concentrations (MDA) and the activities of ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase were all analyzed in the fishes' livers and gills after 2 and 7 days of exposure to different concentrations of diesel (0.1 and 0.5 mL/L). In the tilapia, MDA levels and the activities of EROD and GST activity in the liver, as well as MDA levels and the activities of GST and SOD in the gill had statistically significant differences between the treatments and between the times of exposure. For the catfish, the same occurred in the case of MDA, EROD, and SOD in the liver and in CAT and SOD in the gills. There were significant differences in the enzyme activity and lipid peroxidation between the species. Although the activity of most enzymes seemed to be more expressive and responsive to diesel in O. niloticus, diesel oil also caused significant effects on oxidative stress parameters in P. anisitsi, even though this species is benthic and thus has less access to insoluble fractions of diesel oil. Therefore, both species can be used as sentinel organisms in environmental biomonitoring of diesel contamination. 相似文献
123.
Cesar A Choueri RB Riba I Morales-Caselles C Pereira CD Santos AR Abessa DM DelValls TA 《Environment international》2007,33(4):429-435
The goal of this work was to establish comparisons among environmental degradation in different areas from Southern Spain (Gulf of Cádiz) and Brazil (Santos and S?o Vicente estuary), by using principal component analyses (PCA) to integrate sediment toxicity (amphipods mortality) and chemical-physical data (Zn, Cd, Pb, Cu, Ni, Co, V, PCBs, PAHs concentrations, OC and fines contents). The results of PCA extraction of Spanish data showed that Bay of Cádiz, CA-1 did not present contamination or degradation; CA-2 exhibited contamination by PCBs, however it was not related to the amphipods mortality. Ría of Huelva was the most impacted site, showing contamination caused principally by hydrocarbons, in HV-1 and HV-2, but heavy metals were also important contaminants at HV-1, HV-2 and HV-3. Algeciras Bay was considered as not degraded in GR-3 and -4, but in GR-3' high contamination by PAHs was found. In the Brazilian area, the most degraded sediments were found in the stations situated at the inner parts of the estuary (SSV-2, SSV-3, and SSV-4), followed by SSV-6, which is close to the Submarine Sewage Outfall of Santos - SSOS. Sediments from SSV-1 and SSV-5 did not present chemical contamination, organic contamination or significant amphipod mortality. The results of this investigation showed that both countries present environmental degradation related to PAHs: in Spain, at Ría of Huelva and Gudarranque river's estuary areas; and in Brasil, in the internal portion of the Santos and S?o Vicente estuary. The same situation is found for heavy metals, since all of the identified metals are related to toxicity in the studied areas, with few exceptions (V for both Brazil and Spain, and Cd and Co for Brazilian areas). The contamination by PCBs is more serious for Santos and S?o Vicente estuary than for the investigated areas in Gulf of Cádiz, where such compound did not relate to the toxicity. 相似文献
124.
Eugenio Erika de Queiros Campisano Ivone Sampaio Pereira de Castro Aline Machado Coelho Maria Alice Zarur Langone Marta Antunes Pereira 《Journal of Polymers and the Environment》2022,30(4):1627-1637
Journal of Polymers and the Environment - The search for a straightforward technology for post-consumer poly(ethylene terephthalate) (PC-PET) degradation is essential to develop a circular economy.... 相似文献
125.
Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the
production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result
of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid
wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production
of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric
acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization
of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry.
The 238U, 234U, 226Ra, and 232Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations
in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric
acid D) > Catal?o (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces
a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced
in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola
soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml
of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under
these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft
drinks is not hazardous to human health in Brazil. Considering these annual additions of 238U, 226Ra, 232Th and 40K, and since these radionuclide should be homogeneously distributed in the upper 10 cm of soils with an assumed apparent density
of 1.5 g/cm3, a maximum increase of 0.19 ± 0.03 Bq kg−1 of soil is expected for 238U and 234U. Thus, the addition of solid waste as phosphate fertilizers to Brazilian agricultural soils does not represent a hazard
to the ecosystem or to human health. 相似文献
126.
Sonia Rodrigues Graham Urquhart Iain Hossack Ma Eduarda Pereira Armando C. Duarte Christine Davidson Andrew Hursthouse Peter Tucker Douglas Roberston 《Environmental Chemistry Letters》2009,7(2):141-148
As part of a harmonised assessment of urban soils (), we investigated the variability of metal content in soils from Aveiro (Portugal) and Glasgow (UK). Samples were collected
from parks and other public open spaces in each city. Metal content (Al, Ca, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and basic soil
parameters (texture, CEC, pH, organic matter) were determined and data investigated using principal component analysis (PCA).
The two cities differ in absolute levels of metal content reflecting industrial and historical development. Factors identified
by PCA included anthropogenic (Cu, Pb, Zn), soil properties and geology, which explain variability when data were assessed
based on metal content, soil properties and land use. This study highlights the contribution from geological background even
in strongly urbanised environments. 相似文献
127.
128.
Ana P. L. Batista Hudson Wallace Pereira Carvalho Gustavo H. P. Luz Paulo F. Q. Martins Maraísa Gonçalves Luiz C. A. Oliveira 《Environmental Chemistry Letters》2010,8(1):63-67
A photocatalyst based on CuO/SiO2 was prepared, and evaluated for the degradation of methylene blue in aqueous medium. The photocatalyst was obtained by calcination
method of copper salt, in the presence of silica. The characterization by XRD, FTIR, and TPR techniques confirmed the formation
of CuO as active phase. SEM studies showed CuO deposited on the surface of SiO2. By ESI-MS, it was demonstrated that the degradation of methylene blue occurs through successive hydroxylations. Photodegradation
assays showed that CuO/SiO2 was efficient for degradation, and that the material worked better in the presence of UV light. 相似文献
129.
Atwill ER Pereira MD Alonso LH Elmi C Epperson WB Smith R Riggs W Carpenter LV Dargatz DA Hoar B 《Journal of environmental quality》2006,35(1):200-206
The first step in assessing the risk of water contamination by Cryptosporidium parvum oocysts from feedlot cattle (Bos taurus) production systems is to quantify the number of C. parvum oocysts present in the fecal material deposited by feedlot cattle. Our primary objective for this project was to estimate the daily environmental load of C. parvum oocysts in fecal material deposited by feedlot cattle from across the central and western USA. Our secondary goal was to genotype isolates of C. parvum from feedlot cattle to help facilitate proper identification of mammalian sources of waterborne C. parvum. Based on 5274 fecal samples from 22 feedlots in seven states (California, Washington, Colorado, Oklahoma, Texas, Nebraska, and South Dakota), we estimated a point prevalence of C. parvum of 0.99 to 1.08% in fecal material from feedlot pens from a wide range of climates and a diverse range of feedlot management systems. On average, fresh fecal material from throughout feedlot systems (recent arrivals to nearing slaughter) contained about 1.3 to 3.6 oocysts/g feces, which roughly translates to about 2.8 x 10(4) to 1.4 x 10(5) oocysts/animal per day. 相似文献
130.
Ainara Corts-Avizanda Henrique M. Pereira Ellen McKee Olga Ceballos Berta Martín-Lpez 《Ambio》2022,51(4):990
AbstractIn the current Anthropocene Era, with numerous escalating challenges for biodiversity conservation, the inclusion of the social dimension into management decisions regarding wildlife and protected areas is critical to their success. By conducting 354 questionnaires in a Mediterranean protected area (the Biosphere Reserve of Bardenas Reales, Northern Spain), we aim to determine sociodemographic factors influencing knowledge levels and perceptions of species and functional groups as, emblematic and threatened. We found that hunters and animal husbandry workers knew more species than other social actors. Additionally, the perception of functional groups as threatened or emblematic differed between social actor groups, with statistically significant associations between perceptions and the characteristics of respondents. Interestingly, we found that although elusive steppe species are globally considered as endangered, these species were the least known by all social actor groups and rarely perceived as emblematic. This research is a novel approach and provides a better understanding of how perceptions can facilitate conservation decisions, particularly regarding endangered speciesGraphic abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01546-6. 相似文献