Indoor vertical farming (VF) may play an important role in tackling future food insecurity as it can reduce the land use requirements for crop land and is not affected by environmental conditions. ...However, its energy-intensive operation and the associated environmental impacts can be a cause for concern. To alleviate these issues, it is desirable to operate VF with renewable energy. Our aim was to investigate the land use requirements for generating renewable energy for VF and whether the land area saved by growing crops in multiple layers is sufficient for energy production. The land area requirements for wind and solar (photovoltaic, PV) energy were assessed for lettuce, tomato, potato and wheat production in VF systems in Spain and Sweden. In addition to current-technology scenarios, future scenarios for technological advancement in VF systems and renewable energy generation were included. The results showed that with current technologies, the saved land area was sufficient to produce enough energy only in the case of using PV for lettuce production. However, with improved technologies, the saved land area was sufficient to produce electricity with PV for all crops except tomatoes in Sweden. In contrast, wind energy only satisfies lettuce production, even with future technologies. This study serves as a guideline for determining the feasibility of VF operated with renewable energy in relation to land area, electricity requirements and renewable electricity generation potential in various regions of Europe.
•Vertical farming (VF) may play an important role in future food insecurity.•Energy production with PV and wind on farmland for VF operation was examined.•A high potential for PV was found with future technological advancement.•Large additional land areas may be necessary for wind energy–operated VF.
Aggression in the workplace is increasingly recognized as a serious problem, but there are few studies about worker aggression toward outsiders in the workplace. We investigated the association ...between aggression and occupational stress among teachers.
This was a cross-sectional study of 1583 teachers, principals, and vice-principals. Aggression was measured using the Japanese version of the Buss-Perry Aggression Questionnaire (BAQ). The survey respondents were classified into tertiles according to the BAQ score. The high BAQ group was defined as the upper tertile for the BAQ total score (BAQ total score 625). Occupational stress was measured using the Japanese version of the Generic Job Stress Questionnaire. Comparisons among the groups were performed using multiple logistic regression analysis.
Of the 1583 respondents, 488 were included in the high BAQ group. After adjusting for demographic and occupational variables, high role conflict and role ambiguity were significantly associated with belonging to the high BAQ group. In subscales of the BAQ, high role conflict and role ambiguity related to high levels of hostility, and physical aggression.
Occupational stress such as role conflict and role ambiguity was associated with aggression among teachers. It is necessary to reduce problems which relates to role conflict and role ambiguity for preventing teachers' aggression.
Novel food production technologies are being developed to address the challenges of securing sustainable and healthy nutrition for the growing global population. This study assessed the environmental ...impacts of microbial protein (MP) produced by autotrophic hydrogen-oxidizing bacteria (HOB). Data was collected from a company currently producing MP using HOB (hereafter simply referred to as MP) on a small-scale. Earlier studies have performed an environmental assessment of MP on a theoretical basis but no study yet has used empirical data. An attributional life cycle assessment (LCA) with a cradle-to-gate approach was used to quantify global warming potential (GWP), land use, freshwater and marine eutrophication potential, water scarcity, human (non-)carcinogenic toxicity, and the cumulative energy demand (CED) of MP production in Finland. A Monte Carlo analysis was performed to assess uncertainties while a sensitivity analysis was used to explore the impacts of alternative production options and locations. The results were compared with animal- and plant-based protein sources for human consumption as well as protein sources for feed. Electricity consumption had the highest contribution to environmental impacts. Therefore, the source of energy had a substantial impact on the results. MP production using hydropower as an energy source yielded 87.5% lower GWP compared to using the average Finnish electricity mix. In comparison with animal-based protein sources for food production, MP had 53–100% lower environmental impacts depending on the reference product and the source of energy assumed for MP production. When compared with plant-based protein sources for food production, MP had lower land and water use requirements, and eutrophication potential but GWP was reduced only if low-emission energy sources were used. Compared to protein sources for feed production, MP production often resulted in lower environmental impact for GWP (FHE), land use, and eutrophication and acidification potential, but generally caused high water scarcity and required more energy.
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•MP had 53–100% lower environmental impacts than animal-based food protein sources.•Compared to peas and nuts, impacts were 47–99% lower when using hydropower.•Compared to feed protein sources, MP had a low to average impact.•However, energy demand for MP is 0.03–25 times that of other feed protein.•Using renewable energy increased the decoupling of MP from planetary resources.
INTRODUCTION: Marine mammals are natural resources for humans. They are also considered as pests in some fisheries. Damage to fisheries by Steller sea lions in northern Japan has increased since the ...1990s. The major factor that drives the relationship between humans and marine mammals has changed from the middle of the 20th century to the early 21st century; this is the result of changes in the extent to which their populations are threatened, the demand for these natural resources, and policies for marine mammal conservation. METHODS: In this paper, we have chosen four major taxa of marine mammals to investigate changes in policies for marine mammals in Japan: Steller sea lions, harbor seals, dugong and cetaceans. Some cetacean species have been overexploited in the past and remain threatened. Their full recovery is still awaited. Other large cetacean species have never been threatened; nevertheless all commercial whaling was placed under a moratorium by the International Whaling Commission in 1982. RESULTS: Japan still catches small cetaceans in coastal whaling operations and large cetaceans for scientific research. Except for cetaceans, the policy for marine mammals has changed from resource use in the middle of the 20th century, to protection in the late 20th century, and to nuisance control since 2014. Environmental groups played an important role in building consensus for these policy changes. DISCUSSION AND CONCLUTIONS: We seek a comprehensive policy that achieves a balanced approach to accommodate three different roles of marine mammals: a natural resource, participants in marine ecosystems and agents of damage to fisheries. We also discuss the importance of stakeholder involvement in changing policies for wildlife management, ranging from complete protection to population control.
In recent decades, conflict between Kuril harbor seals (Phoca vitulina stejnegeri) and local fisheries have become a serious problem in Hokkaido, northern Japan. Catch damage in large-scale salmon ...set nets may be mitigated by attaching a rope grid to set net funnels. We investigated the effectiveness of different rope grids on catch damage caused by seals, and evaluated hidden impacts on catch caused by the seals using an underwater camera for observation of seal and salmon behavior coupled with on-board observations of catch and catch damage. The rate of seal prevention was highest for rope grid with 20 cm × 20 cm spacing (97.5 %). The percentage of catch damage in the set net with this rope grid was significantly lower than that for the set net with other rope grid which was easy to enter for seals. We concluded that it is effective to attach an appropriate rope grid to set nets to prevent seals from entering fish bags and to ensure salmon catch amounts. The existence of “hidden damage” was quantitatively revealed via the underwater observation of seals removing salmon from the fish bag, and by comparing the number of salmon between underwater observation and on-board observation.
We examined the home range and habitat use of three female brown bears (Ursus arctos) in the Urahoro region, eastern Hokkaido, Japan, where crop depredation by bears has increased since 1996. The ...average annual home range size calculated by the minimum convex polygon method was 43.04 ± 9.52 km2 (mean ± SD, N = 5). Summer (June–September) home ranges were larger than spring (April–May) and fall (October–December) ranges. The home range of brown bears in the region was larger than those in other areas of Hokkaido, such as the Oshima and Shiretoko Peninsulas. This suggests that habitat quality and population density are lower in the Urahoro region than in other areas. One of two bears for which we examined habitat preferences depended on crop fields during the late summer, whereas the other bear remained in the forest throughout the year. Brown bears in this area preferred mixed forest and avoided deciduous broadleaf forest and conifer plantations.
Polymer electrolytes consisting of a homogeneous poly(ethylene glycol) (PEG) network and LiNTf2 (NTf2: bis(trifluoromethanesulfonyl)amide) were prepared by an addition reaction between two tetra-arm ...PEGs (tetra-PEG; Mn = 10,000) with a maleimide group and an amino group at the polymer ends. Their properties were compared with those containing C2mimNTf2 (C2mim: 1-ethyl-3-methylimidazolium). Michael addition reaction between the maleimide and amino groups yielded polymer electrolyte membranes with homogeneous network structures. The glass transition temperature (Tg) of the polymer electrolytes containing LiNTf2 was observed to be lower than those of conventional polymer electrolytes using PEG. The low Tg values contributed to relatively high ionic conductivity (6.3 × 10−5 S cm−1 at 30 °C with Li/O = 0.10) compared to that of conventional polymer electrolytes. Moreover, superior mechanical properties including an elastic modulus of 171 kPa and fracture energy of 1890 kJ m−3 were achieved due to the homogeneous network structure. Furthermore, the electroactive actuation behaviors of polymer actuators using polymer electrolytes containing either LiNTf2 or C2mimNTf2 were explored. The LiNTf2-based polymer actuator was observed to exhibit larger displacement with slower response compared to the C2mimNTf2-based actuator. The bending directions were opposite in these two actuators. These behaviors were well described by a model that considers the ionic volume and ionic transference number of the polymer electrolytes.
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•Polymer electrolytes comprising a homogeneous PEG network and LiNTf2 were prepared.•The obtained polymer electrolytes exhibited superior mechanical properties.•Tgs were low compared with conventional PEG-based electrolytes.•A high ionic conductivity was achieved in ever obtained polymer electrolytes.•Bending behavior of polymer actuator could be well described by a model equation.
Rotaxane cross-linked polymers (RCPs) derived from ionic liquid monomer (ILm) and butyl acrylate were prepared through radical copolymerization in the presence of a vinyl-based rotaxane crosslinker. ...The developed RCPs exhibited superior mechanical properties compared to analogous network polymers prepared with conventional covalent crosslinkers. In addition, a small amount of ILm toughened the formed RCPs and increased their toughness. Moreover, the developed RCPs showed ionic conductivity in the order of 10−7 S cm−1 at 25 °C.
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•RCPs derived from ionic liquid monomer (ILm) were prepared.•A small amount of ILm toughened the formed RCPs and increased their toughness.•RCPs with ionic conductivity in the order of 10−7 S. cm−1 at 25 °C were prepared
Life cycle assessment of plant cell cultures Kobayashi, Yumi; Kärkkäinen, Elviira; Häkkinen, Suvi T. ...
The Science of the total environment,
02/2022, Letnik:
808
Journal Article
Recenzirano
Odprti dostop
A novel food such as plant cell culture (PCC) is an important complementary asset for traditional agriculture to tackle global food insecurity. To evaluate environmental impacts of PCC, a life cycle ...assessment was applied to tobacco bright yellow-2 and cloudberry PCCs. Global warming potential (GWP), freshwater eutrophication potential (FEUP), marine eutrophication potential, terrestrial acidification potential (TAP), stratospheric ozone depletion, water consumption and land use were assessed. The results showed particularly high contributions (82–93%) of electricity consumption to GWP, FEUP and TAP. Sensitivity analysis indicated that using wind energy instead of the average Finnish electricity mix reduced the environmental impacts by 34–81%. Enhancement in the energy efficiency of bioreactor mixing processes and reduction in cultivation time also effectively improved the environmental performance (4–47% reduction of impacts). In comparison with other novel foods, the environmental impacts of the PCC products studied were mostly comparable to those of microalgae products but higher than those of microbial protein products produced by autotrophic hydrogen-oxidizing bacteria. Assayed fresh PCC products were similar or close to GWP of conventionally grown food products and, with technological advancements, can be highly competitive.
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•Environmental impacts of plant cell culture (PCC) production were assessed.•High contributions of electricity (82–93%) for some impact categories were revealed.•Optimization of bioreactor operation could reduce environmental impacts up to by 47%.•Environmental impacts of PCC and microalgae products were comparable.•Global warming potential of fresh PCC was close to that of heated greenhouse crops.
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