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1.
During the last years, evidence has been accumulated indicating that the annual cycles of physiological and behavioral functions in animals are often preprogrammed as endogenous circannual rhythms. Under seasonally constant environmental conditions these rhythms persist for several cycles with periods deviating from year, whereas under natural conditions they are usually synchronized by seasonal changes in the environment, particularly that of photoperiod. Hence, the annual rhythm of photoperiod constitutes a Zeitgeber for the endogenous rhythmicity rather than providing causal stimuli that release particular activities at particular times of the year. On the basis of this new concept several peculiarities of annual biological rhythms under the influence of photoperiodic cycles with different properties can be better understood, at least at a formal level.  相似文献   

2.
Imprinting Disorders (ImpDis) are a group of congenital conditions caused by aberrant imprinting resulting in disturbed expression of parentally imprinted genes. ImpDis are rarely associated with major malformations, but pre- and/or postnatal growth and nutrition are often affected. In some ImpDis, behavioral, developmental, metabolic and neurological symptoms might present in the perinatal context or later in life, and in single ImpDis, there is a higher risk of tumors in childhood. Prognosis depends in part on the molecular cause of each ImpDis, but due to high clinical variability and (epi)genetic mosaicism, predicting the clinical outcome of a pregnancy solely based on the underlying molecular disturbance is difficult. Therefore, interdisciplinary care and treatment approaches play an important role in the management and decision making of affected pregnancies, especially taking into account fetal imaging in addition to genetic findings. Prenatal findings influence perinatal management, and thereby improve the prognosis of ImpDis associated with severe but sometimes transient clinical complications in the neonatal period. Therefore, prenatal diagnosis can be crucial for appropriate management not only to the pregnancy itself but might also have a life-long effect.  相似文献   

3.
The impacts of climate change, drought and desertification are closely interlinked, and most acutely experienced by populations whose livelihoods depend principally on natural resources. Given the increases in extreme weather events projected to affect the Southern Africa region, it is essential to assess how household and community-level adaptations have been helped or hindered by institutional structures and national policy instruments. In particular, there is a need to reflect on efforts related to the United Nations’ environmental conventions to ensure that policies support the maintenance of local adaptations and help retain the resilience of socio-economic and environmental systems. This paper examines three interlinked drivers of adaptation: climate change, desertification and drought, assessing the extent to which international and national policy supports local adaptive strategies in three countries in southern Africa. We show that while common ground exists between desertification and climate change adaptations at the policy level, they are insufficiently mainstreamed within broader development approaches. Similarly, there are some overlaps between policy-driven and autonomous local adaptations, but the mutually supportive links between them are poorly developed. Further efforts to integrate local adaptation strategies within policy could increase local resilience to environmental change, while also contributing to wider development goals.  相似文献   

4.
The lessons of history indicate that mismanagement of natural resources and the environment often leads to potentially adverse consequences.The increasing interest in economic development,particularly in the developing countries of the world coupled with increasing population pressures and the globalization of economic activity is placing noticeable stresses on the ultimate sustainability of both human and environmental systems.Sustainable development is not a new concept.It has been an area of concern for different elements of society for some time.Yet efforts to understand the implications of sustainable development have not,until recently,been formalized.We have focused singularly on economic development and environmental quality as if they were mutually exclusive.This paper focuses on the concept of concurrency as both a conceptual framework and practicable method of understanding and implementing the ecology and economy of sustainability.  相似文献   

5.
Increasing competition has been forcing the modern manufacturing organisations to adopt advanced manufacturing paradigms. Agile Manufacturing (AM) is an advanced manufacturing paradigm that enables an organisation to survive in the competitive business environment. Agility is the performance measure of AM practices. Simultaneously, modern business organisations are forced to evolve environmental friendly products. Sustainability is regarded as an important concept for survival by the modern organisations. In this context, agility and sustainability are regarded as performance measures for contemporary organisations. This paper reports a case study which has been carried out in an Indian rotary switches manufacturing organisation. The candidate product is the knob of rotary switch. Initially Computer Aided Design (CAD) has been used to digitalise the baseline model. Keeping the baseline model as reference, five new knob models have been evolved. Then the sustainability analysis has been carried out to determine the environmental impact of the knob models. The analysis results indicated that the proposed knob models possess minimal environmental impact. The conduct of case study has lead to an inference that there is a significant improvement of agility and sustainability in the design and development of knob of rotary switch.  相似文献   

6.
The methodologies, approaches and indicators for assessing the impacts of freshwater usage are still evolving. The development of the water footprint concept has been an important step in this direction but the existing methodologies mainly assess the quantity of water used rather than the related impacts. Although there is a recognised need to consider the latter, particularly on a life cycle basis, the difficulty is that there are little or no reliable data on water usage in life cycle databases; furthermore, there is no agreed life cycle impact assessment method for estimating impacts related to freshwater use. However, there have been some methodological developments which propose methods for inventory modelling and impact assessment for water use in life cycle assessment. This paper reviews some of these approaches and discusses their strengths and limitations through a case study, which considers the impacts of freshwater consumption from corn-derived ethanol produced in 12 different countries. The results show a huge variation in the results between different methods and demonstrate the need for a standardised methodology for assessing the impacts of water use on a life cycle basis. Specific recommendations for further research in this field have been made accordingly.  相似文献   

7.
Companies committed to integrating sustainability concerns into product decisions are confronted with the daunting task of assessing hundreds, or thousands, of materials and goods. Further complicating efforts have been the rapid growth of environmental and social assessment principles, strategies, actions, and tools. The lack of clarity on how existing approaches are complementary or distinct has resulted in ambiguities about pathways forward for companies. This current state of the field highlights the need to draw out interconnections between the wide range of current work on integrating environmental and social issues into material, product, and other business decisions.This article—developed through collaboration among several environmental, social, and sustainability-oriented researchers and practitioners—addresses this need through building upon pre-existing work [J. Cleaner Prod. 10(3) (2002) 197; J. Cleaner Prod. 8(3) (2000) 243]. It proposes adaptations on a framework for organizing the assessment field, including development of exemplary sustainable product characteristics and their inclusion in a “strategic sustainable development” decision-making model and process [J. Cleaner Prod. 10(3) (2002) 197]. The article also argues for an expansion of analytical approaches within this previously developed framework in order to highlight social aspects of sustainability and landscape-level issues. Finally, the article puts these elements together to describe a pathway forward for companies. In the conclusion, areas for future research are highlighted.  相似文献   

8.
Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.  相似文献   

9.
This paper presents social sciences modeling approaches (SSMA) that have been coupled to material flow analyses in order to support management of material flows. The presented literature review revealed that the large share of these approaches stem from economics, as these models have similar data and modeling structure than the material flow models. The discussed modeling approaches support a better system understanding and allow for estimating the potential effects of economic policies on material flows. However, it has been shown that these approaches lack important aspects of human decision-making and, thus, the designed economic measures might not always lead to the expected improvements of the material system.  相似文献   

10.
国外生态-经济系统整合模型研究进展   总被引:14,自引:0,他引:14  
高群 《自然资源学报》2003,18(3):375-384
生态-经济系统整合模型的研究将生态的、经济的、社会的以及生物物理模型整合在可持续发展框架中,考察生态系统与经济系统之间的相互作用和反馈关系,采用遥感与计算机建模技术,结合多种生态模型和计量经济模型,预测、模拟、优化生态-经济系统。它的研究范围从整个系统的管理和全球生命支撑系统的可持续性到自然资源和环境服务的可持续使用等等,为分析可持续发展而按照不同的论题建立不同的模型框架。生态经济整合模型的建立是今后生态经济学研究的一个最重要的侧面,生态经济学要想取得主流经济学的地位,必须应用整合的方法深入探索生态经济系统的复杂性和不确定性,真正解决实际问题,为生态与经济的正确决策提供依据。  相似文献   

11.
Fluence rate (FR) distribution (optical field) is of great significance in the optimal design of ultraviolet (UV) reactors for disinfection or oxidation processes in water treatment. Since the 1970s, various simulation models have been developed, which can be combined with computational fluidic dynamic software to calculate the fluence delivered in a UV reactor. These models strive for experimental validation and further improvement, which is a major challenge for UV technology in water treatment. Herein, a review of the simulation models of the FR distribution in a UV reactor and the applications of the current main experimental measurement approaches including conventional flat-type UV detector, spherical actinometer, and micro-fluorescent silica detector (MFSD), is presented. Moreover, FR distributions in a UV reactor are compared between various simulation models and MFSD measurements. In addition, the main influential factors on the FR distribution, including inner-wall reflection, refraction and shadowing effects of adjacent lamps, and turbidity effect are discussed, which is helpful for improving the accuracy of the simulation models and avoiding dark regions in the reactor design. This paper provides an overview on the simulation models and measurement approaches for the FR distribution, which is helpful for the model selection in fluence calculations and gives high confidence on the optimal design of UV reactors in regard to present methods.  相似文献   

12.
Chemical signals emitted by insects and their hosts are important for sexual communication and host selection. Plant volatiles facilitate the location of suitable hosts for feeding and oviposition, and may moderate responses to sex and aggregation pheromones. While mating has been shown to moderate behavioral responses to pheromones in a number of insects, little is known about the effects of mating on behavioral responses of insects to plant attractants, and even less is known about the mechanisms involved. In this study, mating was shown to decrease behavioral responses of the Colorado potato beetle to a host kairomone within 24 h, and attraction to the kairomone recovers only after 72 h. This decrease in responsiveness also occurs when only contact with the opposite sex is allowed; the effect is not observed with contact among individuals of the same sex. Peripheral olfactory responses to a component of the kairomone correlate with the observed behavioral responses and suggest involvement of antennal receptors in the behavioral change.  相似文献   

13.
The environmental impact of industrial wastewater and higher cost of fresh water are the serious challenges faced by the process industries. It has led to the development of many new techniques to minimize fresh water consumption. Of the many approaches, which have been developed, the Water Source Diagram (WSD) is a flexible and dynamic alternative for the generation of different scenarios for the management of water networks with reduction in total consumption. In the present study WSD concept was coupled with water mains concept to mains simplify the piping network and reduce the cost. A new procedure was developed for integrating the effluent treatment processes to evolve Effluent Treatment Network. Example from literature having multi contaminants was considered. This simple procedure involving hand calculations will be a useful tool for process engineers to design water and effluent treatment networks. Also the WSD and ETN were combined to form an evolutionary WAMEN (Water Allocation and Mass Exchange Network) and the proposed WAMEN aims for minimum fresh water consumption.  相似文献   

14.
While the adaptive function of black eumelanin-based coloration is relatively well known, the function of reddish-brown pheomelanin-based coloration is still unclear. Only a few studies have shown or suggested that the degree of reddish-brownness is associated with predator–prey relationships, reproductive parameters, growth rate and immunity. To gain insight into the physiological correlates of melanin-based coloration, I collected barn owl (Tyto alba) cadavers and examined the covariation between this colour trait and ovary size, an organ that increases in size before reproduction. A relationship is expected because melanin-based coloration often covaries with sexual activity. The results showed that reddish-brown juveniles had larger ovaries than whiter juveniles particularly in individuals in poor condition and outside the breeding season, while in birds older than 2 years lightly coloured females had larger ovaries than reddish-brown conspecifics. As barn owls become less reddish-brown between the first and second year of age, the present study suggests that reddish-brown pheomelanic and whitish colorations are associated with juvenile- and adult-specific adaptations, respectively.  相似文献   

15.
过去20年中,基因组学的研究成果未能对疾病发生原因提供本质的认识,人们较早意识到环境因素对于人体健康的重要性.早期对于人体暴露的研究主要集中在内外暴露的研究,未综合考虑人体总的环境暴露.自暴露组(exposome)概念提出以来,得到了广泛关注,也使暴露科学的内涵和外延得到了延伸.暴露组是指一个人从出生至生命结束全过程各种暴露的总和,真正意义上探讨污染暴露、人体健康和疾病发生的实在本质,包括了外暴露、内暴露和社会暴露.研究方法上结合了基于生物监测的"自上向下"法和基于监测空气、水和食物等"自下向上"法,而在研究手段上涉及了环境科学的外暴露和基因组学的分子生物学等中广泛应用的研究技术.然而当前准确测量暴露组仍然是一个巨大的挑战,只有多学科技术手段和研究方法发展和融合才能更好地促进暴露组研究的进步.我国暴露科学研究起步较晚,目前学者对于暴露组的研究仍然薄弱,本文主要从暴露组的概念、研究方法以及测量技术手段入手,介绍这一新兴的研究科学.  相似文献   

16.
Soil and groundwater contamination resulting from leaking underground fuel tanks has placed an enormous burden on regulatory agencies entrusted with cleanup of these sites. Considerable effort and resources have already been invested in developing effective methodologies to assess risks and identify suitable remedial options that facilitate site closure in an expedient manner. Risk-based corrective action approaches have been developed to streamline regulatory decision making process that could lead to cost-effective cleanup solutions. However, the implementation of corrective action programs has often been problematic, primarily due to lack of suitable tools that enable understanding of long-term contaminant behavior at the site. Effective management of these sites requires a comprehension of how risks vary in time at the receptor point and how different remedial technologies aid in reducing these risks. This understanding will result in the development of effective management options that are efficient and transparent at all levels. A systems-based management paradigm has been developed by integrating risk assessment and remedial evaluation into a unified framework. The application of the model to risk management at a gasoline-contaminated site is illustrated in this paper. The model results provide valuable insights and add transparency to the decision making process.  相似文献   

17.
The regional characteristics of the eyes of butterflies from different families have been surveyed using epi-illumination microscopy, utilizing the eyeshine visible due to the tapetum situated proximally to the rhabdom. All butterflies studied have a high spatial acuity in the frontal region. The facet diameter varies slightly across the eye, and the interommatidial angle and the eye parameter p are especially large dorsally. Whereas the ommatidial lattice is generally highly regular, the eyeshine colours distinctly depend on the species. Sometimes the eyeshine is locally uniform, but often it is heterogeneous. It is hypothesized that the regional characteristics as well as the local heterogeneity are adaptations that optimize spectral discrimination.  相似文献   

18.
Massively parallel sequencing has revolutionized our understanding of Mendelian disorders, and many novel genes have been discovered to cause disease phenotypes when mutant. At the same time, next-generation sequencing approaches have enabled non-invasive prenatal testing of free fetal DNA in maternal blood. However, little attention has been paid to using whole exome and genome sequencing strategies for gene identification in fetal disorders that are lethal in utero, because they can appear to be sporadic and Mendelian inheritance may be missed. We present challenges and advantages of applying next-generation sequencing approaches to gene discovery in fetal malformation phenotypes and review recent successful discovery approaches. We discuss the implication and significance of recessive inheritance and cross-species phenotyping in fetal lethal conditions. Whole exome sequencing can be used in individual families with undiagnosed lethal congenital anomaly syndromes to discover causal mutations, provided that prior to data analysis, the fetal phenotype can be correlated to a particular developmental pathway in embryogenesis. Cross-species phenotyping allows providing further evidence for causality of discovered variants in genes involved in those extremely rare phenotypes and will increase our knowledge about normal and abnormal human developmental processes. Ultimately, families will benefit from the option of early prenatal diagnosis. © 2014 John Wiley & Sons, Ltd.  相似文献   

19.
This study contributes to current knowledge of sustainability in textile and clothing production and consumption. When the textile and clothing industry aims to promote sustainability, the main change factors have been linked to eco-materials and ethical issues in production. At present, however, business models are mainly linked with a large volume of sales and production. Although industrial development has moved toward smaller environmental impact, production as well as consumption has increased to levels where the benefits of technological development are reduced. A change is thus needed to reach a systemic transformation, not only in production but also in consumption. The aim of this paper is to open up the discussion on opportunities for radical change in this industry. The paper presents ways to rethink and redesign business in the textile and clothing field by offering an overview on several design strategies that exist today in niche markets. Furthermore we evaluate how interested consumers are in these design strategies and discuss the opportunities these design approaches offer to sustainable development through new value creation.  相似文献   

20.
基于流程需求的施工企业安全管理信息化分析   总被引:1,自引:0,他引:1  
大型施工企业下属二级企业和工程项目部多且地域分布广,施工投入大量的人员、设备物资并涉及多种施工工艺,企业本部掌握工程项目施工安全现状并实施有效监管,以及工程项目各级管理部门和人员规范落实安全工作流程,在信息采集和传递手段效率低下的条件下无法有效实现。"互联网+"在我国多行业已得到了广泛应用,在过程标准化管理、企业内部信息汇总分析、企业各业务部门信息共享方面能极大地提高效率。按照管理信息化的思维,分析施工安全管理业务流程对信息化的功能需求,构建了施工企业安全管理信息化模型,据此模型基层管理人员可标准化实施流程业务、自动真实生成工作记录资料,管理部门可及时动态掌握和监督基层安全管理工作开展现状,从而提高企业安全管理工作的高效性。  相似文献   

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