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141.
The chemical signals of solitary and territorial felid species are essential for their intraspecific communication. We studied the selection of plant substrates during the fecal marking behavior of the European wildcat Felis silvestris from September 2008 to June 2009 in a protected area in Northwest Spain. The aim of the study was to examine the selection of plants as signal posts with respect to their physical characteristics. We hypothesized that wildcats deposit their fecal marks on plants with physical characteristics (e.g., size, species, and visual conspicuousness) that enhance the olfactory and visual effectiveness of the signal. Our results indicate that diameter, plant group, visual conspicuousness, and interaction between the diameter and plant group influence the decision of wildcats to deposit their fecal marks on plants. The wildcats chose plants with greater diameters and greater visual conspicuousness as scent-marking posts. Moreover, the wildcats chose woody and herbaceous plants, and certain plant species were marked more frequently than expected at random. Indeed, our results indicate that the fecal marks were not randomly distributed on the plants: the wildcats chose to place their marks on plants with certain physical characteristics that maximized the detectability of the signal by intruders and potential mates, thus facilitating the spatial distribution of the species. 相似文献
142.
Jeanger P Juanga Chettiyappen Visvanathan Josef Tr?nkler 《Waste management & research》2007,25(1):30-38
The optimization of anaerobic digestion aims to maximize organic waste stabilization after a short digestion period. This paper presents the optimization performance of the combined anaerobic digestion and sequential staging concept in a thermophilic, solid-state batch system as a treatment technology prior to landfill. The former involves enhanced pre-stage flushing with the addition of microaeration and inoculum in the methane phase. The latter involves leachate cross-recirculation between the mature and fresh waste reactors without conducting a pre-stage operation. The optimized process for combined anaerobic digestion showed that reducing the pre-stage operation with the maximum removal of organics from the waste bed is beneficial. Moreover, the sequential staging concept offers an improved process over the combined anaerobic digestion wherein the specific methane yield of 11.9 and 7.2 L CH4 kg(-1) volatile solids (VS) per day was achieved, respectively. After 28 days of operation, the sequential staging process showed an improved waste stabilization with 86 and 79% mass and volume reduction, respectively. A higher methane yield of 334 L CH4 kg(-1) VS with 86% VS reduction, which is equivalent to 84% process efficiency was obtained. 相似文献
143.
Raija Ilmarinen Helena M?kinen Harri Lindholm Anne Punakallio Heikki Kervinen 《International journal of occupational safety and ergonomics》2008,14(1):7-18
Fire fighters are normally overprotected during their working hours because of the tendency to keep the personal protection level sufficiently high in case of the worst possible scenarios. This study investigated the effects of task-fitted protective clothing on thermal strain in fire fighters as compared to EN 469:2005 protective clothing during a prolonged (2 1/2 hrs) job-related rescue drill under neutral and hot climates. The subjects were 23 healthy, physically fit professional male fire fighters aged 26-44 years. Measurements included cardiovascular and thermal responses and subjective assessments. Wearing task-fitted clothing during rescue tasks in a neutral climate considerably reduced total thermal and cardiovascular strain in prolonged rescue work. The fire fighters also perceived physical work as significantly harder on average, and reported more intense subjective discomfort while wearing EN 469:2005 as compared to task-fitted clothing. 相似文献
144.
Jaber?Aazami Abbas?Esmaili Sari Asghar?Abdoli Hormoz?Sohrabi Paul?J.?Van den?BrinkEmail author 《Environmental management》2015,56(1):260-269
The objectives of this study were to assess the biological water of the Iranian Tajan River using different metrics, i.e., a Multimetric Macroinvertebrate Index (MMI) and a traits-based method. Twenty-eight physico-chemical parameters, 10 habitat factors, and abundance of macroinvertebrates were obtained for 17 sites. The Shahid-Rajaie dam divides the Tajan River into an up- and downstream part, with different land uses. Eighteen metrics were used to represent four components of ecosystem quality, including tolerance (Hilsenhoff, SIGNAL), diversity (Margalef, Shannon–Wiener, Simpson, and Evenness), abundance (total number of taxa, individuals, Ephemeroptera, Plecoptera, Trichoptera, EPT, and Insects), and composition of assemblages (% Ephemeroptera, % Plecoptera, % Trichoptera, and % EPT Taxa). The integrated MMI was calculated by averaging the obtained scores of all indices. In the next step, we gathered information on 22 biological traits of macroinvertebrates to evaluate whether (group of) traits could be identified that are indicative for specific or general stress. Result showed a decrease in MMI from upstream (very good water quality) to downstream (bad) due to human activities. Industrial activities like pulping and papermaking operations or sand mining in the downstream part had more effects than agriculture and fish ponds in the upstream part. A redundancy analysis biplot showed the variation between the modalities of trait of macroinvertebrates and their correlation with physico-chemical parameters in Tajan River. The findings show that traits can be indicative for different kind of stress but that more effort has to be put in gathering data sets to disentangle the effect of habitat quality, pollution, and the physico-chemical properties of high- versus lowland rivers. 相似文献
145.
This paper examines the relationship between the development of the dominant industrial food system and its associated global economic drivers and the environmental sustainability of agricultural landscapes. It makes the case that the growth of the global industrial food system has encouraged increasingly complex forms of “distance” that separate food both geographically and mentally from the landscapes on which it was produced. This separation between food and its originating landscape poses challenges for the ability of more localized agricultural sustainability initiatives to address some of the broader problems in the global food system. In particular, distance enables certain powerful actors to externalize ecological and social costs, which in turn makes it difficult to link specific global actors to particular biophysical and social impacts felt on local agricultural landscapes. Feedback mechanisms that normally would provide pressure for improved agricultural sustainability are weak because there is a lack of clarity regarding responsibility for outcomes. The paper provides a brief illustration of these dynamics with a closer look at increased financialization in the food system. It shows that new forms of distancing are encouraged by the growing significance of financial markets in global agrifood value chains. This dynamic has a substantial impact on food system outcomes and ultimately complicates efforts to scale up small-scale local agricultural models that are more sustainable. 相似文献
146.
采用GC-MS测定了典型综合印染废水处理厂废水和污泥中芳香烃化合物的含量.结果表明,原水中苯系物总量为203.96±15.18μg·L-1,其中二甲苯占62.7%,尾水中苯系物总量为0.2±0.029μg·L-1,整个处理工艺对苯系物的去除效率为99%.原水中多环芳烃(PAHs)总浓度达1349.51±35.77 ng·L-1,以3—6环为主,主要富集在颗粒物上.整个工艺对PAHs的去除效率为95%,尾水中PAHs总浓度为65.81±20.99ng·L-1,以2—3环为主.干污泥中PAHs含量高达2996.10±151.0 ng·g-1,污泥吸附为水相中PAHs去除的主要机理之一.印染污泥直接填埋或农用会引起潜在的生态危害. 相似文献
147.
This Φ Ψ study of environmental equity uses secondary quantitative data to analyze socioeconomic disparities in environmental
conditions in the Rijnmond region of the Netherlands. The disparities of selected environmental indicators—exposure to traffic
noise (road, rail, and air), NO2, external safety risks, and the availability of public green space—are analyzed both separately and in combination. Not only
exposures to environmental burdens (“bads”) were investigated, but also access to environmental benefits (“goods”). Additionally,
we held interviews and reviewed documents to grasp the mechanisms underlying the environmental equity situation, with an emphasis
on the role of public policy. Environmental equity is not a priority in public policy for the greater Rotterdam region known
as the Rijnmond region, yet environmental standards have been established to provide a minimum environmental quality to all
local residents. In general, environmental quality has improved in this region, and the accumulation of negative environmental
outcomes (“bads”) has been limited. However, environmental standards for road traffic noise and NO2 are being exceeded, probably because of the pressure on space and the traffic intensity. We found an association of environmental
“bads” with income for rail traffic noise and availability of public green space. In the absence of regulation, positive environmental
outcomes (“goods”) are mainly left up to market forces. Consequently, higher-income groups generally have more access to environmental
“goods” than lower-income groups. 相似文献
148.
Ethics,Narrative, and Agriculture: Transforming Agricultural Practice through Ecological Imagination
The environmental degradation caused by industrial agriculture, as well as the resulting social and health consequences, creates
an urgency to rethink food production by expanding the moral imagination to include agricultural practices. Agricultural practices
presume human use of the earth and acknowledge human dependence on the biotic community, and these relations mean that agriculture
presents a separate set of considerations in the broader field of environmental ethics. Many scholars and activists have argued
persuasively that we need new stories to rethink agricultural practice, however, the link—the story that does and can shape
agricultural practice—has not yet been fully articulated in environmental discourse. My analysis explores how language has
shaped existing agricultural models and, more important, the potential of story to influence agricultural practice. To do
this, I draw upon cognitive theory to illustrate how metaphoric and narrative language structures thought and influences practice,
beginning with my contention that industrial agriculture relies on a discourse of mechanistic relations between humans and
a passive earth, language that has naturalized the chemically intensive monocultures prevalent in much of the American Midwest.
However, alternative agricultures, including organic agriculture, agro-ecology, and ecological agriculture, emphasize qualities
such as interdependence and reciprocity and do so as a deliberate response to the perceived inadequacies of industrial agriculture
and its governing narrative. Exploring the different discourses of agricultural systems can help us think through different
modalities for human relations with the biotic community and demonstrate story’s potential role in altering practice. 相似文献
149.
The biology of the endangered leatherback turtle (Dermochelys coriacea) at sea is poorly understood. As research has been almost exclusively limited to studies of nesting females, the movements of male turtles and the timing and location of mating activity have remained unknown. We report on the first deployments of satellite tags on male leatherbacks. Male migration to and residency in waters adjacent low-latitude nesting beaches in the western Atlantic suggest that this is where mating occurs, and return migration to these areas reveals male fidelity for breeding sites. Rate of travel decreased markedly after arriving in coastal breeding areas, where males remained for up to 96 days before assuming northward migrations. The initiation of these northward migrations coincided with peak nesting activity in adjacent nesting colonies. Data from satellite-linked time-depth recorders attached to two males revealed diel dive patterns in breeding areas and marked differences in diving behaviour between migratory and breeding periods in one turtle. When male turtles were in waters adjacent nesting colonies, their movements differed from those reported for nesting females, with females ranging farther from shore. Our results suggest that male leatherbacks may be vulnerable to entanglement in coastal fishing gear in waters adjacent nesting beaches.Communicated by R.J. Thompson, St. Johns 相似文献
150.
Victoria?SorokerEmail author Dennis?R.?Nelson Ornit?Bahar Saadia?Reneh Sarah?Yablonski Eric?Palevsky 《Chemoecology》2003,13(4):163-168
Summary. Broad mite, Polyphagotarsonemus latus (Acari:
Tarsonemidae) exhibits a specific phoretic relationship with
whiteflies. Under field conditions most broad mites, caught
in sticky traps, are attached to whiteflies. Under laboratory
conditions, attachment occurs equally well in the dark and
light. Mites do not differentiate between the sexes of their
phoretic host Bemisia tabaci. However, mite attachment to
B. tabaci is greatly diminished by washing the host with
various organic solvents, chloroform in particular. The
effect of whitefly waxy particles on broad mite behavior was
studied using wax from the whitefly Aleyrodes singularis
and from the mealybug Planococcus citri. Broad mites were
not only attracted specifically to the A. singularis waxy
particles-treated leaf areas but were also attached to leaf
trichomes in this area. The results of this study suggests the
importance of olfactory cues from the whitefly waxy particles
in the recognition process of the phoretic host and/or
the induction of the attachment behavior to whitefly legs or
leaf trichomes. 相似文献