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Francisco?J.?Ayala-carcedo Manuel?Regueiro?Y?González-BarrosEmail author 《Environment, Development and Sustainability》2005,7(1):95-115
This paper deals with the various factors that condition underdevelopment in the world. It suggests some alternatives and points out the potential opportunities that both the developed and the underdeveloped world will have in the coming years to change the gloomy prospects that we see today. The present paper outlines the trends in historical priorities in development, changing as they pass from economic development to social development to ecological conservation – the three pillars of Sustainable Development.The paper analyses the importance of geography, a very relevant and often neglected conditioning factor. Also, it analyses the role of socio-economic conditioning factors like political immaturity, demographics, land ownership and external debt.Furthermore, the current opportunities for economic take-off are presented, from cash surpluses to low interest rates, from natural resource management to tourism or migration, from the Information Revolution to liberalisation of agricultural markets. Current obstacles are also analysed. The paper, on the basis of current facts and figures, reaches the conclusion that there is a structural need for sustained development aid for most poor countries, but it must be distributed in a more rational way.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
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Among sedentary species, mate and site fidelity may be imposed by year-round territoriality and high annual survivorship, both of which theoretically lead to few opportunities to move between mates and breeding territories. We examined mate and territory fidelity in sedentary neotropical buff-breasted wrens (Thryothorus leucotis) in relation to the opportunities to divorce (vacancies on neighbouring territories), breeding experience and site of origin (within vs outside local breeding population). Overall, buff-breasted wrens showed high rates of mate and territory fidelity between years, with individuals significantly more faithful to their territories than to their partners. Mate and territory fidelity was not forced upon buff-breasted wrens, as most individuals had opportunities to switch mates and territories. However, this was not uniform among all individuals. Individuals that had bred together displayed 100% mate and territory fidelity despite the fact that males and females in almost all experienced pairs had opportunities to switch mates and territories. Local recruits (philopatric offspring that acquired territories in the local breeding population) also displayed mate and territory fidelity, but fidelity occurred because recruits rarely had the opportunity to divorce prior to initiating their first breeding attempt. By contrast, almost half of all territorial individuals that originated outside the local breeding population (immigrants) had opportunity to divorce, with approximately two thirds of them switching mates and territories. Divorces occurred within the first 5 months of pairing, suggesting that immigrants may have sampled mates and territories before forming permanent partnerships. 相似文献
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J.?MartínEmail author P.?López W.?E.?CooperJr. 《Behavioral ecology and sociobiology》2003,54(5):505-510
Because time spent in refuge may be costly if prey lose opportunities to forage, fight, or mate, prey allow predators to approach closer before beginning to flee when opportunity costs are high. Because the same opportunity costs may apply to refuge use as to escape, prey should make similar trade-offs between risk of emerging and cost of remaining in refuge. In the Iberian rock lizard, Lacerta monticola, we studied the effects of sex, reproductive season, speed of predator approach, and potential loss of mating opportunities on time spent in refuge following simulated predatory attacks. Lizards of both sexes adjusted refuge use to the level of risk by spending more time in refuge when approached rapidly than slowly. Females remained in refuge for equal times in the mating and postreproductive seasons, but males emerged sooner during the mating season, suggesting adjustment to a cost of lost opportunity to search for mates during the mating season. When a tethered female was nearby, males emerged from refuge earlier than if no female was present, indicating a trade-off between risk and mating opportunity. Approach speed affected emergence time when females were absent, but not when a female was present. Approach speed did not affect the probability that, after emerging, a male would return to court the female. For males that courted females intensely (bit them) before entering refuge, approach speed did not affect latency to emerge, but males that courted less intensely emerged sooner if approached slowly than rapidly. These findings show that males adjust the length of time spent in refuge to both risk of predation and reproductive cost of refuge use.Communicated by A. Mathis 相似文献
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近年来西藏旅游业得到较快发展,但仍存在基础设施建设不足、环境破坏日益严重、旅游成本过高等一系列问题。我国对西藏旅游业的发展给予了高度重视,青藏铁路的全线运营给西藏旅游业发展带来了前所未有的机遇和动力,同时也对西藏的社会环境、生态环境构成了潜在的威胁,作者对此作了简要剖析并提出了对策建议。 相似文献
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Petrochemical enterprises have become a major source of global greenhouse gas (GHG) emissions. Yet, due to the unavailability of basic data, there is still a lack of case studies to quantify GHG emissions and provide petrochemical enterprises with guidelines for implementing energy conservation and emission reduction strategies. Therefore, this study conducted a life cycle assessment (LCA) analysis to estimate the GHG emissions of four typical petrochemical enterprises in China, using first-hand data, to determine possible emission reduction measures. The analytical data revealed that Dushanzi Petrochemical (DSP) has the highest GHG emission intensity (1.17 tons CO2e/ton), followed by Urumqi Petrochemical (UP) (1.08 tons CO2e/ton), Dalian Petrochemical (DLP) (average 0.58 tons CO2e/ton) and Karamay Petrochemical (KP) (average 0.50 tons CO2e/ton) over the whole life cycle. At the same time, GHG emissions during fossil fuel combustion were the largest contributor to the whole life cycle, accounting for about 77.31%–94.27% of the total emissions. In the fossil-fuel combustion phase, DSP had the highest unit GHG emissions (1.20 tons CO2e), followed by UP (0.89 tons CO2e). In the industrial production phase, DLP had the highest unit GHG emissions (average 0.13 tons CO2e/ton), followed by UP (0.10 tons CO2e/ton). During the torch burning phase, torch burning under accident conditions was the main source of GHG emissions. It is worth noting that the CO2 recovery stage has "negative value," indicating that it will bring some environmental benefits. Further scenario analysis shows that effective policies and advanced technologies can further reduce GHG emissions. 相似文献
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李文婷 《湖南环境生物职业技术学院学报》2011,17(2):45-47
近年来我国服务贸易保持着稳健发展,逐步跻身全球服务贸易大国行列.国际金融危机对我国服务贸易的发展既是严峻挑战,又带来了新的发展机遇.本文就在国际金融危机背景下,中国服务贸易面对机遇和挑战将如何开放提出了几点对策. 相似文献
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“碳达峰和碳中和”的科学内涵及我国的政策措施 总被引:1,自引:0,他引:1
巢清尘 《环境与可持续发展》2021,(2):14-19
中国提出的"碳达峰和碳中和"目标是基于统筹国际国内两个大局的战略考量,基于科学论证的国家战略需求提出的,实现这一目标挑战和机遇并存。我国的承诺为全球高质量绿色复苏注入了强心剂和新活力,但实现该目标比发达国家面临更大挑战。它将倒逼我国社会经济结构进行重大调整,对科技创新提出了新要求,会给经济高质量发展、建设美丽中国带来机遇。建议切实贯彻我国"十四五"规划纲要提出的"碳强度控制为主,碳排放总量控制为辅的双控目标",充分考虑将碳排放总量控制目标考核和现有污染减排考核体系相结合,增强"十四五"的行动力。尽快制定碳中和目标下的科技创新规划和实施方案。统筹考虑短期经济复苏、中期结构调整、长期低碳转型,布局低碳/脱碳技术,提升未来绿色产业竞争力。 相似文献
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在全球气候变暖的背景下,以低能耗、低污染、低排放为基础的低碳经济成为全球热点。论述了我国发展低碳经济所面临的压力和挑战,提出发展低碳经济是我国的必然选择,由高碳经济向低碳经济转变对我国经济的发展起到促进作用,同时对有色金属工业在发展低碳经济中所面临的形势和机遇进行分析,为政府、企业在发展低碳经济过程中应担当的责任和做法提出建议。 相似文献
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