In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks. 相似文献
This study examined the adverse effects of N,N,N′,N′-tetramethylethylenediamine (TEMED) on electric eel (Electrophorus electricus) acetylcholinesterase (AChE) and human serum butyrylcholinesterase (BChE). Data show that TEMED inhibited AChE in electric eel as well as human serum BChE. Kinetic studies indicated that the inhibition produced by TEMED in both sources was of mixed type, i.e. Km increased and Vmax decreased in a concentration-dependent manner. KI (constant of ChE–substrate–TEMED complex into ChE–substrate complex and TEMED) was estimated to be 0.674 mM for electric eel and 0.024 mM for human serum BChE. The γKm (dissociation constant of ChE–substrate–TEMED complex into ChE–TEMED complex and substrate) was 0.083 and 0.2 mM for electric eel AChE and human serum BChE, respectively. The IC50 for electric eel and for human serum ChE was 1.57 and 0.043 mM, respectively. The present results suggest that TEMED produced adverse effects on electric eel and human serum via inhibition of ChE. 相似文献
Behavioral Ecology and Sociobiology - The killing of young by unrelated males is widespread in the animal kingdom. In short-lived small rodents, females can mate immediately after delivery... 相似文献
Concentration levels, seasonal variation and winter/summer ratios of 11 polycyclic aromatic hydrocarbons (PAHs) in the TSP of Las Palmas de Gran Canaria city were determined. The study area is under the influence of heavy traffic (80000 vehicles/day). Pyr/BaA, Pyr/Flt, B(ghi)P/I(cd)P and B(b+k)F/B(ghi)P ratios were calculated; the values of these two last suggest a strong influence of diesel fuel burning. Levels of TSP and TSP-bound PAHs were also established. The hazard potential of PAHs in terms of carcinogenicity of BaP is acceptable. Potential risk on the basis of TEFs is also studied. 相似文献
Silica gel surface has been modified in two reaction steps: (i) the silylating agent 3-mercaptopropyltrimetoxysilane was firstly immobilized to give a surface Sil-SH and (ii) this precursor incorporated an ethylene sulfide molecule to obtain the surface denoted Sil-SSH. This material was characterized by elemental analysis, IR spectroscopy, thermogravimetry, solid state 13C and 29Si NMR, and surface area measurement. These materials were employed as adsorbents for divalent heavy cations from aqueous solutions at room temperature and the isotherms were adjusted to a modified Langmuir equation. The maxima number of moles adsorbed were 1.0, 1.5, 1.6, 2.2, 2.4 and 3.3 mmol g(-1) for Co, Cu, Ni, Cd, Pb, and Hg, respectively. 相似文献
In addition to encoding referential information and information about the sender’s motivation, mammalian alarm calls may encode
information about other attributes of the sender, providing the potential for recognition among kin, mates, and neighbors.
Here, we examined 96 speckled ground squirrels (Spermophilus suslicus), 100 yellow ground squirrels (Spermophilus fulvus) and 85 yellow-bellied marmots (Marmota flaviventris) to determine whether their alarm calls differed between species in their ability to encode information about the caller’s
sex, age, and identity. Alarm calls were elicited by approaching individually identified animals in live-traps. We assume
this experimental design modeled a naturally occurring predatory event, when receivers should acquire information about attributes
of a caller from a single bout of alarm calls. In each species, variation that allows identification of the caller’s identity
was greater than variation allowing identification of age or sex. We discuss these results in relation to each species’ biology
and sociality. 相似文献
Society needs to adapt in order to provide the wealth that an increasing part of the world population is getting used to.
We are on a track to ecological and resource collapse if actions are not taken soon. Technology will have to play a key role
in the process of changing industrial society. But innovation has to be embedded in social and organizational innovation.
We need sociotechnical change. Environmentally conscious design has been practiced in engineering design for more than a decade.
Its merits are sometimes blamed as futile, as the world has not witnessed a significant contribution to the solution of the
larger (global) problems. This paper first sketches a scheme of the various levels of technological change, ranging from:
(1) incremental optimizations of single artifacts, to (2) major change of artifacts, (3) systems change, and (4) technological
transitions (involving changes in production and consumption). It outlines the stakeholders involved in these types of innovations
and the parties that could orchestrate the innovation process. In this paper, It is argued that the most encompassing level
of technological innovation, the level of transition, is crucial for achieving long-term sustainable development, as it has
the largest potential for improvement. However, transition is not very well manageable. The paper contains a review of the
literature regarding the occurrence of technological transitions. After a transition has occurred, the new system is often
not efficient. Its gains in terms of diminished resource consumption or pollution have to be enlarged by less encompassing
innovation strategies, such as systems innovations and product optimization. Transitions for sustainable development are often
impossible, as the new systems have to compete with fully developed and optimized systems that have far advanced at the learning
curve, i.e., are optimized by various systems and incremental innovations. Less encompassing levels of innovation, even those
that aim at more sustainability, can counteract transitions that have more potential for sustainable development by improving
the competing (unsustainable) technology. The paper will give several examples of this dilemma and some guidelines for developing
government policies as well as corporate strategies. On the policy level, it is argued that it is especially important to
develop (scope for) market niches for new sustainable systems and products as they create scope for experiments that could
lead to transitions.
Converting raw biomass into valuable products protects the environment, improves economics, and helps tackle climate change by cutting resource demand and waste production. Thermochemical treatment is a common method for producing biochars, hydrochars and torreficates from biomass and organic wastes, which can also generate dioxins and furans and consequently limit the use of thermochemically converted chars. Here we review the presence of dioxins and furans in chars produced by hydrothermal carbonization, torrefaction, and pyrolysis processes under the influence of temperature, residence time, heating rate, pressure, and feedstock type. Dioxins and furans were mostly below 20 ng total toxic equivalence per kilogram (TEQ kg−1), with the highest level of 113 ng TEQ kg−1 found in over 100 samples of different char types. The most toxic products were hydrochars produced from sewage sludge. Processing temperature and feedstock type were key factors resulting in high dioxin levels in chars, and care should be taken when producing chars at temperatures up to 300 °C or using feedstocks previously contaminated with dioxins or preservatives.