Affiner votre recherche
Résultats 1-4 de 4
Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development
2015
Gillespie, Colin | Stabler, Daniel | Tallentire, Eva | Goumenaki, Eleni | Barnes, Jeremy
A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions – pollen originating from plants raised in charcoal-Purafil® filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol−1 O3 (10 h d−1) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit – a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during ‘risk assessment’ exercises.
Afficher plus [+] Moins [-]Inventory review and environmental evaluation of first- and second-generation sugars through life cycle assessment
2021
Bello, Sara | Salim, Iana | Feijoo, Gumersindo | Moreira, Maria Teresa
In recent years, there has been a great movement towards the generation of knowledge related to the biorefinery concept. First-generation biorefineries bear the stigma of using arable land and edible crops for fuel instead of as sources of food and feed. However, second-generation biorefineries have not reached the level of full technical feasibility. Bearing in mind the objective of sugar production from sugar, starch, or lignocellulosic raw materials, the purpose of this study is to assess the environmental impact of first- and second-generation biorefineries, considering as an example for the comparative evaluation, the production of sugar fractions from crops (starch and sugar crops), and lignocellulosic biomass (hardwood and softwood). The characterization results were obtained using the ReCiPe 1.1 model, implemented through the SimaPro 9.0 software. Both production systems are inherently different and have strengths and weaknesses that must be carefully analyzed. The resulting environmental profile shows that the silviculture of wood contributes less to the environmental impact than cropping activities in most impact categories. In general, this study suggests that first-generation systems are burdened environmentally by the use of fertilizers, which have a significant impact on categories such as marine and freshwater eutrophication and terrestrial acidification, while second-generation systems are limited by the intensive processing steps needed for delignification, typically involving the use of chemicals and/or energy. LCA in early stages of the production of bio-based building blocks, rather than on the manufacture of biofuels or bioplastics, allows the precise identification of the environmental burdens that may be influencing the overall environmental profile of a biorefinery.
Afficher plus [+] Moins [-]Occupational stress, job satisfaction, and intent to leave: nurses working on front lines during COVID-19 pandemic in Zagazig City, Egypt
2021
Said, Randa M. | El-Shafei, Dalia A.
During epidemics, the medical working environment is highly stressful especially for the nurses. The purpose of this study was to assess occupational stress, job satisfaction, and intent to leave among nurses dealing with suspected COVID-19 patients. A comparative cross-sectional study was conducted among 210 nurses from Zagazig Fever Hospital (ZFH) which is one of COVID-19 Triage Hospitals (Group I) versus 210 nurses from Zagazig General Hospital (ZGH) (Group II) which is neither triage nor isolation hospital; dealing only with suspected COVID-19 patients in emergency at Sharkia Governorate, Egypt, from 10th to 24th of April 2020. Assessment was done through online questionnaire formed of the Expanded Nursing Stress Scale, the McCloskey/Mueller Satisfaction Scale, and questionnaire assessing specific COVID-19-associated stressors and nurses’ intent to leave. Three quarters of nurses (75.2%) in ZFH had high stress level versus 60.5% in ZGH. Workload (98.6%), dealing with death and dying (96.7%), personal demands and fears (95.7%), employing strict biosecurity measures (95.2%), and stigma (90.5%) represented the highest priority stressors in ZFH, while exposure to infection risk (97.6%) was the stressor of highest priority among ZGH according to Pareto analysis. More than half of nurses (51.0%) in ZFH reported low satisfaction level versus 41.9% in ZGH. Only 4.8% of nurses in ZFH definitely had no intent to leave their present job. Type of hospital and its related workload were the most significant predictor of all the studied outcomes.
Afficher plus [+] Moins [-]Energy analyses and greenhouse gas emissions assessment for saffron production cycle
2015
Bakhtiari, Amir Abbas | Hematian, Amir | Sharifi, Azin
Population growth and world climate changes are putting high pressure on agri-food production systems. Exacerbating use of energy sources and expanding the environmental damaging symptoms are the results of these difficult situations. This study was conducted to determine the energy balance for saffron production cycle and investigate the corresponding greenhouse gas (GHG) emissions in Iran. Saffron (Crocus sativus L.) is one of the main spice that historically cultivated in Iran. Data were obtained from 127 randomly selected saffron growers using a face to face questionnaire technique. The results revealed that in 5 years of saffron production cycle, the overall input and output energy use were to be 163,912.09 and 184,868.28 MJ ha⁻¹, respectively. The highest-level of energy consumption belongs to seeds (23.7 %) followed by chemical fertilizers (23.4 %). Energy use efficiency, specific energy, net energy, and energy productivity of saffron production were 1.1, 13.4 MJ kg⁻¹, 20,956.2 MJ ha⁻¹, and 0.1 kg MJ⁻¹, respectively. The result shows that the cultivation of saffron emits 2325.5 kg CO₂ eq. ha⁻¹ greenhouse gas, in which around 46.5 % belonged to electricity followed by chemical fertilizers. In addition the Cobb-Douglas production function was applied into EViews 7 software to define the functional relationship. The results of econometric model estimation showed that the impact of human labor, electricity, and water for irrigation on stigma, human labor, electricity, and seed on corm and also human labor and farmyard manure (FYM) on flower and leaf yield were found to be statistically significant. Sensitivity analysis results of the energy inputs demonstrated that the marginal physical productivity (MPP) worth of electricity energy was the highest for saffron stigma and corm, although saffron flower and leaf had more sensitivity on chemicals energy inputs. Moreover, MPP values of renewable and indirect energies were higher than non-renewable and direct energies, respectively.
Afficher plus [+] Moins [-]