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21.
How do youth learn through participation in efforts to study and change the school food system? Through our participatory youth action research (YPAR) project, we move beyond the “youth as consumer” frame to a food justice youth development (FJYD) approach. We track how a group of youth learned about food and the public policy process through their efforts to transform their own school food systems by conducting a participatory evaluation of farm-to-school efforts in collaboration with university and community partners. We used the Photovoice research method, placing cameras in the hands of young people so that they themselves could document and discuss their concerns and perspectives. The research was designed to gain insight about youths’ knowledge of food, health, and community food systems. Drawing upon the youth group’s insights, we build a framework for building critical consciousness through FJYD.  相似文献   
22.
Ambio - Social media images are a novel source of data to assess how people view and value the environment. Access to these images is often free, the volume and spread of images is expanding...  相似文献   
23.
Agricultural crops have a long history of being irrigated with recycled wastewater (RW). However, its use on vegetable crops has been of concern due to the potential prevalence of microcontaminants, such as pharmaceuticals and personal care products (PPCPs) in the latter, which represents a possible health hazard to consumers. We investigated the uptake of three PPCPs (atenolol, diclofenac, and ofloxacin), at three different concentrations in irrigation water (0.5, 5, and 25 μg L?1) in relation to three varying volumetric soil moisture depletion levels of 14 % (?4.26 kPa), 10 % (?8.66 kPa), and 7 % (?18.37 kPa) by various vegetable crop species. Experiments were conducted in a split-split block completely randomized design. PPCPs were extracted using a developed method of accelerated solvent extraction and solid phase extraction and analyzed via liquid chromatography mass spectrometry (LCMS). Results indicate that all treated crops were capable of PPCP uptake at nanogram per gram concentrations independent of the applied soil moisture depletion levels and PPCP concentrations. Ofloxacin was the chemical with the highest uptake amounts, followed by atenolol and then diclofenac. Although the results were not statistically significant, higher concentrations of PPCPs were detected in plants maintained under higher soil moisture levels of 14 % (?4.26 kPa).  相似文献   
24.
This paper builds on past behavioural research which explicitly recognises that ‘actions’ are preceded by ‘intentions’ which are in turn determined by individual mindsets, locus of control, principles of governances and context factors. More concretely, it presents a model that investigates the extent to which environmental behavioural intentions are explained by i) managers' core values, basic assumptions, and beliefs, ii) individual and socio-cognitive frames, iii) principles of governance, and iv) context factors. Context factors include obstacles and drivers of greener behaviours, market pressures, and firm demographics. The resulting theoretical framework is tested empirically through regression analyses that use data gathered from a survey of 536 Argentinean firms in polluting industries. The model performs well, explaining approximately 50% of the variations in the (pro) environmental behaviour of firms. Policy implications are briefly discussed.  相似文献   
25.
How do distinct visual stimuli help bumblebees discover flowers before they have experienced any reward outside of their nest? Two visual floral properties, type of a pattern (concentric vs radial) and its position on unrewarding artificial flowers (central vs peripheral on corolla), were manipulated in two experiments. Both visual properties showed significant effects on floral choice. When pitted against each other, pattern was more important than position. Experiment 1 shows a significant effect of concentric pattern position, and experiment 2 shows a significant preference towards radial patterns regardless of their position. These results show that the presence of markings at the center of a flower are not so important as the presence of markings that will direct bees there.  相似文献   
26.
PROBLEM: It has been established that graduated licensing systems lead to crash reductions among beginning drivers. What is the contribution of the various components of graduated licensing to these reductions, and how can their effectiveness be increased? METHOD: Literature review and synthesis. RESULTS: Extended learner periods, nighttime restrictions, and passenger restrictions have contributed to crash reductions. Presently there is insufficient evidence concerning the contribution of seat belt or cell phone provisions, or contingent advancement penalties. DISCUSSION: There is more to learn about graduated licensing and its component features. However, there are ways to increase the contribution of all the components through stronger laws and greater compliance. With the right kind of community commitment and focus, substantial further reductions in young driver crashes are achievable. IMPACT ON INDUSTRY: The results can guide states in establishing graduated licensing systems that maximize crash reductions.  相似文献   
27.
The potential for airborne emissions to undergo long-range transport or to be removed from the atmosphere is influenced by their physical-chemical properties. When perfluorooctanate (PFO) enters the environment, its physical-chemical properties can vary significantly, depending on whether it exists as an acid, a salt, or a dissociated ion. A summary of the physical-chemical properties of the three most likely environmental states: ammonium perfluorooctanoate (APFO), perfluorooctanoic acid (PFOA) and the dissociated perfluorooctanoate anion (PFO(-)) is presented to illustrate the distinct environmental properties of each. The most volatile species, PFOA, is shown to have a pH-dependent air-water partitioning coefficient (K(aw)). The variability of K(aw) with pH influences the potential for vapor formation from aqueous environments, including rain events. Using the pH-dependent K(aw) and measured rain and air concentrations, it is shown that vapor-phase PFOA is not likely to be present above measurable levels of 0.2 ng m(-3) (12 parts per quadrillion v/v) during a rain event. Because rain concentrations determined in this work are comparable to measurements in other parts of North America, it is unlikely that rain events are a significant source of vapor-phase PFOA for the general North American region. It is shown that PFOA exists primarily in the particle phase in ambient air near direct sources of emissions and is efficiently scavenged by rain droplets, making wet deposition an important removal mechanism for emissions originating as either PFOA or APFO. Washout ratios of particle-associated PFO were determined to range between 1 x 10(5) and 5 x 10(5), in the same range as other semi-volatile compounds for which wet deposition is an important mechanism for atmospheric removal and deposition onto soils and water bodies.  相似文献   
28.
Pirard C  De Pauw E 《Chemosphere》2007,66(2):320-325
Except for fish, no toxicokinetic data on polybrominated diphenyl ethers (PBDEs) is available on relevant animals for the human food chain. In the present work, absorption, elimination through eggs and disposition of PBDEs in laying chickens were studied and compared to dioxin behaviour. Hens were fed with diet containing 3.4 mg/kg feed of PBDEs and 0.95 ng TEQ/kg feed of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs). PBDEs have been demonstrated to show drastically different behaviours from PCDD/Fs and dioxin-like compounds. Excretion of PBDEs increased for two weeks and then decreased to nearly 0%. Sixty-two percent of ingested 2,2',4,4'-tetraBDE (BDE-47) were found in excreta after two weeks, suggesting a reductive debromination of PBDEs in the digestive tract. PBDE level in eggs increased during five weeks and reached 24 microg/g fat. After then, levels decreased to 3 microg/g fat at the end of the trial. PBDE bioconcentration factors estimated for abdominal fat varied from 0.7 for BDE-47 to 2 for BDE-183.  相似文献   
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30.
Environmental Science and Pollution Research - Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study...  相似文献   
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