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1.
The International Journal of Life Cycle Assessment - After analyzing in previous papers the potential of Environmental Product Declarations (EPDs) as a sustainability tool in Mexico’s...  相似文献   

2.
The International Journal of Life Cycle Assessment - A solid legislative framework and a strong sense of environmental sensitivity by the government are some of the elements that have contributed...  相似文献   

3.
The International Journal of Life Cycle Assessment - Environmental product declarations (EPDs) are standardized tools based on life cycle assessment (LCA) to communicate and compare environmental...  相似文献   

4.
As one of important building materials, the sustainability of cement production is widely concerned in the world. This research evaluated the sustainability of China’s cement industry in 2010 using emergy analysis. Several emergy based indicators were adopted to describe the comprehensive performance of this system from different angles, including Percentage of renewability (%R), Unit emergy value (UEV), Emergy yield ratio (EYR), Emergy exchange ratio (EER), Environmental load ratio (ELR) and Emergy sustainable index (ESI). The research results show that (1) Mineral resources have absolute contribution to China’s cement production; (2) Coal is the main energy source for China’s cement industry; (3) China’s cement industry has relatively weak competition ability due to relatively high ratio of purchased inputs; (4) China’s other industries have benefited greatly from this industry by exchanges; (5) China’s cement industry cannot keep sustainable in the long run due to its high environmental load; (6) the UEV of Chinese cement in 2010 is 3.64E15 sej/t (based on the emergy baseline 15.83E24 sej/yr). Finally, the related policy implications are proposed from four aspects, including (1) Accelerating the adjustment of process structure and technical innovation; (2) Promoting the substitution of raw materials or fuels; (3) Raising the price of cement products; (4) Decreasing the export of cement products.  相似文献   

5.
AimDescribe the results of the first national census of radiotherapy in Mexico in order to make a situational diagnosis of radiotherapy availability, offer more accurate information to radiation oncologists, and promote an adequate scientific based investment for the country.BackgroundAccording to the Organisation for Economic Co-operation and Development (OECD), the density of radiotherapy (RT) machines per million habitants in Mexico is approximately 1.7−1.8. Other international organizations such as DIRAC-IAEA report 1.15 per million habitants. National organizations collect data indirectly and previous surveys had a low accrual rate (32.5%). Therefore, a precise census is required.Material and methodsThe Mexican Radiation Oncology Certification Board (CMRO for its acronym in Spanish) conducted a nationwide census from January through November 2019. Gathered information was combined with CMRO database for sociodemographic information and human resources.ResultsThe study included 103 RT centers [95.1% answered the survey], with a median of 2 centers by state (ranging from 0 in Tlaxcala to 20 in Mexico City) and with a report of only 1 center in 11 states (34.4%). Fifty-six (54.3%) of the centers are public. Fourteen centers (13.6%) have residency-training programs. The total number of RT machines is 162 [141 clinical and linear accelerators (87%) and 21 radionuclide units (13%)] with a median of 3 machines by state (0 in Tlaxcala to 46 in Mexico City) and with ≤3 machines in 18 states (56.25%). The overall calculated density of RT machines per million habitants is 1.32, varying from 0 in Tlaxcala to 5.16 in Mexico City. The density of linear and clinical accelerators per million population is 1.19. The total number of brachytherapy units is 66, with a median of 1 center with brachytherapy unit per state and 29 states with ≤3 centers with a brachytherapy unit (90.6%). Thirty-seven brachytherapy units (56.1%) have automated afterload high-dose rate. The overall rate of brachytherapy units per million inhabitants is 0.55, varying from 0 in 5 states (15.6%), 0.1-0.49 in 8 states (25%), 0.5–0.99 in 13 states (40.6%), 1–1.49 in 5 states (15.6%) and 1.5–1.99 in Mexico City (3.1%). The Mexican CMRO has 368 radiation oncologists certified (99 women and 269 men), of whom only 346 remain as an active part of Mexico's workforce.ConclusionsThis is the first time the CMRO conducts a national census for a radiotherapy diagnostic situation in Mexico. The country currently holds a density of clinical and linear accelerators of 1.19 per million habitants. Brachytherapy density is 0.55 devices per million habitants, and 57% of radiotherapy centers have brachytherapy units.  相似文献   

6.
7.
Alzheimer??s disease (AD) is a progressive neurodegenerative disorder. The human brain is extremely sensitive to hypoxia, ischemia, and glucose depletion. Impaired delivery of oxygen in obstructive sleep apnea (OSA) alters neuronal homeostasis, induces pathology, and triggers neuronal degeneration/death. This article systematically delineates the steps in the complex cascade leading to AD, focusing on pathology caused by chronic intermittent hypoxia, hypertension, brain hypoperfusion, glucose dysmetabolism, and endothelial dysfunction. Hypoxia/hypoxemia underpins several pathological processes including sympathetic activation, chemoreflex activity, neuroinflammation, oxidative stress, and a host of perturbations leading to neurodegeneration. The arterial blood flow reduction in OSA is profound, being about 76?% in obstructive hypopneas and 80?% in obstructive apneas; this leads to cerebral ischemia promoting neuronal apoptosis in neocortex and brainstem. OSA pathology also includes gray matter loss in the frontal, parietal, temporal, and occipital cortices, the thalamus, hippocampus, and key brainstem nuclei including the nucleus tractus solitarius. (18)F-FDG PET studies on OSA and AD patients, and animal models of AD, have shown reduced cerebral glucose metabolism in the above mentioned brain regions. Owing to the pathological impact of hypoxia, hypertension, hypoperfusion and impaired glucose metabolism, the adverse cardiovascular, neurocirculatory and metabolic consequences upregulate amyloid beta generation and tau phosphorylation, and lead to memory/cognitive impairment??culminating in AD. The framework encompassing these factors provides a pragmatic neuropathological approach to explain onset of Alzheimer??s dementia. The basic tenets of the current paradigm should influence the design of therapeutic strategies to ameliorate AD.  相似文献   

8.
The complicated task of measuring environmental sustainability has often led to comparative evaluations of national performance using ranking lists and generic policy targets. In this paper, a set of national environmental indicators is determined through the deployment of a five-stage methodology, which includes the use of focus group research and formation of an expert team to guide the process, selection of an initial pool of pre-existing indicators, establishment of criteria to guide the selection process, and setting of appropriate policy or trend-based targets given the nation-specific context. The nations of Iceland and Norway are used as case studies to demonstrate an effective means of communicating indicator outcomes over time. National performance is first evaluated on an indicator-by-indicator basis and then summarised overall through a system of traffic lights and radar charts for trend and target-based indicators respectively. Via this analytical process, it also becomes clear that data shortages partially constrain the extent to which a nation’s environmental sustainability performance can be deciphered. Improved data collection is necessary connected to the measurement of several environmental issues on a national scale, particularly the sustainability of fisheries, soil erosion and biodiversity.  相似文献   

9.
The purpose of this study was to build an aggregate index of social–environmental sustainability derived from incorporation of indicators of the quality of soil, water, and vegetation, and social organization and socioeconomic variables, in order to assess the overall social–environmental quality in a micro watershed in the Southern Amazon. From a population of 105 family production units 56 were randomly selected for evaluation of indicators of the quality of soil and water as well as for conducting interviews to evaluate the farmers’ perception of soil, water, and vegetation quality and also of socioeconomic aspects of agroecosystems. The aggregate index built from social–environmental sustainability indicators shows that the selected indicators were adequate for describing social–environmental quality and confirms the hypothesis that the studied micro-watershed in the southern edge of the Amazon is in a state of collapse, and is socially and environmentally degraded.  相似文献   

10.
A promising strategy for treating Alzheimer’s disease (AD) is hippocampal neurogenesis enhancement. Tenuigenin (TEN) is a bioactive compound extracted from Polygala tenuifolia that is widely used for treating amnesia in Chinese medicine. However, whether TEN is effective in treating AD through hippocampal neurogenesis is not fully clear. This study aimed to explore the pharmacologic effect and underlying mechanism of TEN on hippocampal neurogenesis and cognitive deficit amelioration in AD. In an in vivo study, TEN administration significantly ameliorated the cognitive decline in APP/PS1 transgenic AD mice via enhancement of hippocampal neurogenesis, which might be attributed to activation of the GSK-3β/β-catenin pathway. Furthermore, an in silico study suggested that TEN might be directly targeted to GSK-3β. Overall, TEN enhanced hippocampal neurogenesis and consequently ameliorated cognitive deficits via GSK-3β/β-catenin pathway activation, indicating that TEN might be a promising novel agent for AD treatment.  相似文献   

11.
Transgenic Research - An intended generalized ban on the “introduction and use of transgenic seeds” has been announced by the Mexican government, which, unlike the other agricultural...  相似文献   

12.
Locust is one of the most predominant agricultural pests in Mexico, followed by non-migratory grasshoppers. Their devastating effects cover numerous Mexican states, generating important economic losses. Metarhizium acridum (Hypocreales: Clavicipitaceae) has been employed in Mexico as a microbial agent for biological control for some time. However, questions related to the long-term persistence and viability of the fungus after it has been sprayed over crop fields remain to be elucidated. To resolve these questions, we performed a study in a crop field where an abundant population of the grasshopper Sphenarium purpurascens (Orthoptera: Pyrgomorphidae) is present. The fungus M. acridum was sprayed during August and October 2007. Its presence in the air, soil and vegetative cover was subsequently monitored using molecular methods and culture techniques. The results showed that the fungus was viable on the ground during the follow-up period (66 weeks). Its population fluctuated markedly, however, reaching four times its initial concentration and later decreasing to nearly half its initial concentration by the end of the study. The initial concentrations of the fungus in the air and in the vegetative cover decayed steadily (with some small, isolated recoveries) until its complete disappearance after 8 months.  相似文献   

13.
Overall nutritional status has been proved associated with people’s health. The overall nutritional status of children in Kashin-Beck disease (KBD) areas has been overlooked for decades. Therefore, it is worth investigating in the current generation to gather evidence and make suggestions for improvement. A cross-sectional study with three 24-h dietary recalls was conducted to collect raw data on the daily food intake of children. Recorded food was converted into daily nutrient intakes using CDGSS 3.0 software. WHO AnthroPlus software was used to analyse the BMI-for-age z-score (BAZ) for estimating the overall nutrition status of children. All the comparisons and regression analyses were conducted with SPSS 18.0 software. Multiple nutrient intakes among children from the Se-supplemented KBD-endemic were under the estimated average requirement. The protein-to-carbohydrate ratio (P/C ratio) was significantly higher in children from the non-Se-supplemented KBD-endemic area than the other areas (P < 0.001). The children’s BAZ was negatively associated with age (B = ?0.095, P < 0.001) and the number of KBD relatives (B = ?0.277, P = 0.04), and it was positively associated with better housing conditions, receiving colostrum, and daily intakes of niacin and zinc by multivariate regression analysis (F = 10.337, R = 0.609, P < 0.001).Compared to non-Se-supplemented KBD-endemic area and non-endemic areas, children in Se-supplemented KBD-endemic areas have an insufficient intake of multiple nutrients. School breakfast and lunch programmes are recommended, and strict implementation is the key to ensuring a positive effect.  相似文献   

14.
Chitosan samples with different molecular weights (Mw) and degree of deacetylation (DD) were prepared by controlling operating conditions throughout the multistage alkali treatment. The temperature of the reaction, time duration and number of reaction steps were considered effective parameters. A database was developed for chitosan preparation in order to achieve high degrees of deacetylation and control the molecular weight of chitosan without changing other molecular structures. The number of treatments and the duration of each step of deacetylation significantly affected molecular weight so that two samples were obtained with a DD of 99% and two different molecular weights ranging from 4.66×105 to 2.93×105 Based on these results, the highest molecular weight obtained using the multistage treatment without decreasing DD was 5.32×105, with a DD of 96.67%. Also, the morphological studies indicate that the molecular weight of chitosan has a significant effect on the pore size of the prepared scaffolds. However, this effect is critical. In other words, the pore size will increase by increasing molecular weight of chitosan from low upto medium molecular weight and when it reached to high molecular weight the pore size is decreased.  相似文献   

15.
In 1790, the German poet Johann W. v. Goethe (1749–1832) proposed the concept of a hypothetical sessile organism known as the ‘Plant Archetype,’ which was subsequently reconstructed and depicted by 19th-century botanists, such as Franz Unger (1800–1870) and Julius Sachs (1832–1897), and can be considered one of the first expressions of Evo-Devo thinking. Here, we present the history of this concept in the context of Ernst Haeckel’s (1834–1919) biogenetic law espoused in his Generelle Morphologie der Organismen of 1866. We show that Haeckel’s idea of biological recapitulation may help to explain why various phenomena, such as the ontogenetic transformations in the stellar anatomy of lycopods and ferns, the transition from primary to secondary anatomy of seed plants, the presence of unfused juvenile cone scale segments in the Japanese cedar (Cryptomeria japonica), and the transition of C3- to C4-photosynthesis in the ontogeny of maize (Zea mays), appear to support his theories. In addition, we outline the current status of plant evolutionary developmental biology (Evo-Devo), which can be traced back to Haeckel's (1866) biogenetic law, with a focus on the model plant thale cress (Arabidopsis thaliana).  相似文献   

16.

Purpose

The static functional unit definition in the current LCA framework has limitations in addressing the changing product functionality and associated environmental impact of constantly evolving product technologies. As a result, it overlooks the changes in consumer behaviour of increased consumption of products in provided services as well as in growing volumes. This article aims to present a new framework in defining a dynamic functional unit of product technologies that caters for changes in consumer behaviour and growing market.

Methods

A new approach to defining the functional unit is proposed that caters for changes in consumer behaviour and the use of technology from a technical performance perspective. A dynamic approach to definition of the functional unit is proposed that is based on Kano’s model of product function and satisfaction.

Results and discussion

The new approach is demonstrated on a case study in which the analysis of historical data for two TV product technologies—CRT and LCD—is used to show how the total environmental impact is increasing due to the increased functionality which triggers an increase in the volume of the market. Despite the efforts of improving product life cycle design, the society is still faced with increasing environmental impact from the product type overall.

Conclusions

This article presents the challenges of using a static, single functional unit definition in an industrial culture with constant evolution of products that influences usage behaviour and demonstrates the vicious circle of improving product efficiency that leads to further consumption and environmental impact. To address this problem, a new framework of dynamic functional unit definition is put forward for performing comparative LCA to manage the development of product life cycle design that helps keep the total environmental impact of the company’s product portfolio within absolute boundaries.
  相似文献   

17.
Chasing genes in Alzheimer’s and Parkinson’s disease   总被引:4,自引:0,他引:4  
Alzheimers disease (AD), the most common type of dementia, and Parkinsons disease (PD), the most common movement disorder, are both neurodegenerative adult-onset diseases characterized by the progressive loss of specific neuronal populations and the accumulation of intraneuronal inclusions. The search for genetic and environmental factors that determine the fate of neurons during the ageing process has been a widespread approach in the battle against neurodegenerative disorders. Genetic studies of AD and PD initially focused on the search for genes involved in the aetiological mechanisms of monogenic forms of these diseases. They later expanded to study hundreds of patients, affected relative-pairs and population-based studies, sometimes performed on special isolated populations. A growing number of genes (and pathogenic mutations) is being identified that cause or increase susceptibility to AD and PD. This review discusses the way in which strategies of gene hunting have evolved during the last few years and the significance of finding genes such as the presenilins, -synuclein, parkin and DJ-1. In addition, we discuss possible links between these two neurodegenerative disorders. The clinical, pathological and genetic presentation of AD and PD suggests the involvement of a few overlapping interrelated pathways. Their imbricate features point to a spectrum of neurodegeneration (tauopathies, synucleinopathies, amyloidopathies) that need further intense investigation to find the missing links.  相似文献   

18.
Plants are an integral part of nature. Many plant species in almost any part of the world are under serious threats due to various reasons such as deforestation, pollution–of air, water and soil–caused by industrialisation, overgrazing and rapid population growth. It is likely that people have strong positive attitudes towards conservation of plants. This study investigated the effectiveness of an instructional approach based on integration of botany with chemistry and art on students’ attitude towards plants. This study was carried out in a science summer school for 10–12-years-old students (N = 49) in Turkey. The Plant Attitude Questionnaire was used as pre-test and post-test to assess the effects of the instruction on the students’ attitudes towards plants. Moreover, the participating children were asked to keep journals throughout the instruction. The children’s journals served as a data collection tool. The findings of the study indicated that integration of botany with chemistry and art is a good way to support children’s positive attitudes towards plants, particularly for an instructional approach based on the integration of plants with various disciplines to support children’s interest and enjoyment of plants. Also, this approach could offer children opportunities to understand the importance of plants in the living environments of humans and other organisms, and material benefits from plants in industry.  相似文献   

19.
Using data collected from people with at least one brother and one sister, and consistent with an evolutionary perspective, we find that older men and women (a) are more upset by a brother’s partner’s sexual infidelity than by her emotional infidelity and (b) are more upset by a sister’s partner’s emotional infidelity than by his sexual infidelity. There were no effects of participant sex or sex of in-law on upset over a sibling’s partner’s infidelities, but there was an effect of participant sex on reports of upset over one’s own partner’s infidelities. The results suggest that the key variable among older participants is the sex of the sibling or, correspondingly, the sex of the sibling’s partner, as predicted from an evolutionary analysis of reproductive costs, and not the sex of the participant, as predicted from a socialization perspective. Discussion offers directions for future work on jealousy.  相似文献   

20.
Offsets, first formalised in the United States of America in the 1970s for wetland mitigation, are now widely used globally with the aim to mitigate loss of biodiversity due to development. Embracing biodiversity offsets is one method of governments to meet their commitments under the Millennium Development Goals and the Convention on Biological Diversity. Resource extraction companies see them as a method of gaining access to land, while the community may perceive them as a way of enhancing environmental outcomes. In New South Wales, Australia, BioBanking legislation was introduced in late 2006 with the aim of ‘no net loss’ of biodiversity associated with development, particularly expanding urban and coastal development. The strengths of the legislation are that it aims to enhance threatened species conservation, and raise the profile of conservation of threatened species and habitats. Weaknesses include (1) the narrowness of the definition of biodiversity; (2) the concepts are based on a flawed logic and immature, imprecise and complex science which results in difficulties in determining biodiversity values; (3) likely problems with management and compliance; and (4) an overall lack of resources for implementation and long-term monitoring. It is concluded that the legislation is a concerted effort to deal with biodiversity loss, however, stakeholders have concerns with the process, and it is unworkable with the complexity of such ecosystems (compared for example to carbon credit trading), and underdeveloped disciplines such as restoration biology and ecology. Despite these criticisms, there is a need for all stakeholders to work to improve the outcomes.  相似文献   

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