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1.
Nonparametric estimation of Shannon’s index of diversity when there are unseen species in sample 总被引:1,自引:0,他引:1
A biological community usually has a large number of species with relatively small abundances. When a random sample of individuals is selected and each individual is classified according to species identity, some rare species may not be discovered. This paper is concerned with the estimation of Shannons index of diversity when the number of species and the species abundances are unknown. The traditional estimator that ignores the missing species underestimates when there is a non-negligible number of unseen species. We provide a different approach based on unequal probability sampling theory because species have different probabilities of being discovered in the sample. No parametric forms are assumed for the species abundances. The proposed estimation procedure combines the Horvitz–Thompson (1952) adjustment for missing species and the concept of sample coverage, which is used to properly estimate the relative abundances of species discovered in the sample. Simulation results show that the proposed estimator works well under various abundance models even when a relatively large fraction of the species is missing. Three real data sets, two from biology and the other one from numismatics, are given for illustration. 相似文献
2.
This study aims to recognize and select the appropriate strategy for implementing green manufacturing (GM) in Indian manufacturing industry by developing an instrument which could measure the progress of an organization towards the GM philosophy. This study identifies and analyses the key enablers behind the successful achievement of environmental sustainability in Indian manufacturing industry. Based on extensive literature review and discussions with experts, the critical success factors (CSFs) of GM have been identified. After examining the internal consistency of enablers, weightage is identified for finalizing the priority by analytical hierarchical process (AHP). The pairwise comparison method of AHP identified that top management commitment, green procurement practices and societal concern for protection of natural environment art the most important enablers, and competitiveness and availability of clean technology have comparatively less importance for the studied manufacturing industries. The purpose of this paper is to rank the enablers on identified weightage and develop the framework for offering the useful insights and guides about how industries should link CSFs of GM to improve the environmental and operational performance. 相似文献
3.
Summary. In the rabbit, lactating females emit a volatile
compound in milk, the mammary pheromone (MP), that
triggers rooting for the nipple and its grasping in pups.
Previous studies have shown that the MP seems to act selectively,
in terms both of intensity and quality. Here, we aimed
to add new evidence to these properties of the MP. Newborn
rabbits (n=825) were submitted to an oral activation test
allowing to measure their searching/grasping responses
towards different stimuli. In Experiment 1 we assessed
whether pups respond to the MP in an intensity-dependent
manner. In Experiment 2 we assessed the activity of 20
volatiles previously identified in rabbit milk, other than the
MP, which were never systematically tested for intensitydependence.
The assays showed that a) neonatal responses
are released by the MP only for a limited range of concentrations;
b) the 20 other odorants from milk are inactive at
any concentration. Thus, the MP appears to be the single
volatile from rabbit milk that releases searching/grasping
behaviour in pups. 相似文献
4.
In seasonal environments, vertebrates are generally thought to time their reproduction so offspring are raised during the peak of food abundance. The mismatch hypothesis predicts that reproductive success is maximized when animals synchronize their reproduction with the food supply. Understanding the mechanisms influencing the timing of reproduction has taken on new urgency as climate change is altering environmental conditions during reproduction, and there is concern that species will not be able to synchronize their reproduction with changing food supplies. Using data from five sites over 24 years (37 site-years), we tested the assumptions of the mismatch hypothesis in the Tree Swallow (Tachycineta bicolor), a widespread aerial insectivore, whose timing of egg-laying has shifted earlier by nine days since the 1950s. Contrary to the mismatch hypothesis, the start of egg-laying was strongly related to food abundance (flying insect biomass) during the laying period and not to timing of the seasonal peak in food supply. In fact, food abundance generally continued to increase throughout the breeding season, and there was no evidence of selection based on the mistiming of laying with the seasonal peak of food abundance. In contrast, there was selection for laying earlier, because birds that lay earlier generally have larger clutches and fledge more young. Overall, initial reproductive decisions in this insectivore appear to be based on the food supply during egg formation and not the nestling period. Thus, the mismatch hypothesis may not apply in environments with relatively constant or abundant food throughout the breeding season. Although climate change is often associated with earlier reproduction, our results caution that it is not necessarily driven by selection for synchronized reproduction. 相似文献
5.
Environmental Fluid Mechanics - In this work, a summary of Leonardo da Vinci’s contribution in the field of fluid mechanics is reported. Some theoretical laws or fluid flows analyzed or drawn... 相似文献
6.
This paper examines the local impacts of shale gas development (SGD). We use a hedonic framework and exploit a discrete change in expectations about SGD caused by the New York State moratorium on hydraulic fracturing. Our research design combines difference-in-differences and border discontinuity, as well as underlying shale geology, on properties in Pennsylvania and New York. Results suggest that New York properties that were most likely to experience both the financial benefits and environmental consequences of SGD dropped in value 23% as a result of the moratorium, which under certain assumptions indicates a large and positive net valuation of SGD. 相似文献
7.
Livingston Glen Allingham David Rayner J. C. W. 《Environmental and Ecological Statistics》2022,29(2):223-239
Environmental and Ecological Statistics - Van Valen’s test is usually applied as a two sample test for equality of dispersion for multivariate data. Motivated by a comment of Manly (Van... 相似文献
8.
The comparison of increasing doses of a treatment to a negative control is frequently part of toxicological studies. For normally distributed data Williams (1971, 1972) introduced a maximum likelihood test under total order restriction. But until now there seems to have been no solution for the arbitrary unbalanced case. According to the idea proposed by Robertson et al. (1988) we will apply in this article the basic concept of Williams on the class of multiple contrast tests for the general unbalanced parametric set-up. Simulation results for size and power and two examples for estimating the minimal toxic dose (MTD) are given. 相似文献
9.
Kwasi Appeaning Addo 《Journal of Coastal Conservation》2011,15(4):433-443
Coastal features in Ghana's Accra coast reflect both past and present processes that have been undergoing changes. These changes
are influenced by a range of morphogenic factors such as geology and climatic conditions. These regimes have shaped the coastal
geomorphic features through weathering processes that decompose and disintegrate the coastal rock. Sea level rise due to climate
change is expected to increase coastal erosion and thus result in rapid changes in shoreline positions. Historic rate of sea
level rise in Accra coast is about 2 mm/yr (Ibe & Quelennec, 1989) which is predicted to reach approximately 6 mm/yr in the
next century since it conforms to the global change (Armah et al., 2005). This will result in flooding of vulnerable areas and enable waves to break closer inland. The effectiveness of the erosion
process is aided considerably by the type of geology. Accra coastal zone has three types of rock in three identified geomorphic
regions. They include unconsolidated and poorly consolidated rock along the western region, the Accraian series occupying
the central region and the Dahomeyan series in the eastern region. The geology has thus influenced the extent to which the
coastal features have changed and the type of cliff that is formed as a result of erosion within the regions. Generally, soft
rock coastal features decay more rapidly than those of hard rock and tend to act as sediment sources. Human activities such
as dam construction over the Densu River, engineering interventions to check the spread of erosion and sand mining has created
sediment deficit which has exacerbated coastal erosion in Accra. Anthropogenic factors are estimated to account for 70-90%
of coastal erosion problems in Accra. 相似文献
10.
Zhuo CHEN Huu Hao NGO Wenshan GUO Xiaochang WANG 《Frontiers of Environmental Science & Engineering》2013,7(4):608-615
Recycled water provides a viable opportunity to partially supplement fresh water supplies as well as substantially alleviate environmental loads. Currently, thousands of recycled water schemes have been successfully conducted in a number of countries and Sydney is one of the leading cities, which has made massive effort to apply water reclamation, recycling and reuse. This study aims to make a comprehensive analysis of recycled water schemes in Sydney for a wide range of end uses such as landscape irrigation, industrial process uses and residential uses (e.g., golf course irrigation, industrial cooling water reuse, toilet flushing and clothes washing etc.). For each representative recycled water scheme, this study investigates the involved wastewater treatment technologies, the effluent quality compared with specified guideline values and public attitudes toward different end uses. Based on these obtained data, multi criteria analysis (MCA) in terms of risk, cost-benefit, environmental and social aspects can be performed. Consequently, from the analytical results, the good prospects of further expansion and exploration of current and new end uses were identified toward the integrated water planning and management. The analyses could also help decision makers in making a sound judgment for future recycled water projects. 相似文献
11.
12.
The most important question raised from issues of environmental degradation is how economic activities bring about changes that will result in pollution. In the pursuit of tourism economy, contrary to popular interest, the travel and tourism (T&T) industry may cause environmental damages through the emissions of carbon dioxide (CO2) from energy consumption in areas such as transportation and delivery of amenities. Given this major concern, this paper attempts to investigate the linkage between tourism and CO2 emissions in Malaysia between 1981 and 2011. In particular, this study fills the knowledge gap by taking a closer look at the impact of international tourist arrivals on CO2 emissions by sector – electricity and heat generation and transport. Results from the bound test method suggest that there exists a long-run relationship among the variables under consideration when CO2 emissions become the dependent variable. The original result is similarly robust to alternatives, which are CO2 emissions from sectors of electricity and heat generation and transport. Furthermore, the vector error correction model causality analysis indicates a causal relationship between tourism and CO2 emissions by transport and electricity and heat generation. Subsequently, several tourism-related policies are drawn from these findings. 相似文献
13.
Using a subsocial spitting spider (Scytodes pallida) as the prey and a spider-eating jumping spider (Portia labiata) as the predator, the cost of parental care is investigated. Our findings suggest that being singled out as preferred prey by P. labiata is, for egg-carrying females of S. pallida, an important cost of parental care. In survival tests, during which P. labiata was given access to egg-carrying and eggless S. pallida females, egg-carrying females were preyed on more often than eggless females. In preference tests, motionless lures instead of living S. pallida were used. The lures were made by mounting dead egg-carrying and dead eggless S. pallida females in lifelike posture in webs. In these tests, P. labiata detected and identified, by vision alone, both kinds of prey (egg-carrying and eggless), and singled out egg-carrying females as preferred prey.Communicated by M.A. Elgar 相似文献
14.
Dirk Semmann Hans-Jürgen Krambeck Manfred Milinski 《Behavioral ecology and sociobiology》2005,57(6):611-616
To find conditions under which humans cooperate within groups of unrelated individuals has been of major interest in the behavioral sciences. The experimental paradigm for studying potential cooperation in social dilemmas is the public goods game. Here humans regularly fail to sustain a public resource cooperatively. However, the need to maintain good reputation for other social interactions, such as indirect reciprocity, has been identified as an effective mechanism to sustain cooperation in public goods situations. As a side effect of building a good reputation through cooperative actions, an individual provides direct benefits to members of his/her own social group. These benefits could be an incentive to reward a good reputation of group members. Here we show experimentally that building a good reputation through cooperative behavior in a public goods situation is rewarded in future social interactions, not only within ones own social group but also, at a similar level, in other social groups: humans regard cooperative behavior of others as an honest signal irrespective of past direct personal benefits. Reputation gained within as well as outside ones own social group can be a driving force for selfish individuals to cooperate in public goods situations, and thereby sustain any public resource.Communicated by T. Czeschlik 相似文献
15.
Unravelling a ‘miner’s myth’ that environmental contamination in mining towns is naturally occurring
Australia has a long history of metal mining and smelting. Extraction and processing have resulted in elevated levels of toxic metals surrounding mining operations, which have adverse health effects, particularly to children. Resource companies, government agencies and employees often construct ‘myths’ to down play potential exposure risks and responsibility arising from operating emissions. Typical statements include: contaminants are naturally occurring, the wind blows emissions away from residential areas, contaminants are not bioavailable, or the problem is a legacy issue and not related to current operations. Evidence from mining and smelting towns shows that such ‘myths’ are exactly that. In mining towns, the default and primary defence against contamination is that elevated metals in adjacent urban environments are from the erosion and weathering of the ore bodies over millennia—hence ‘naturally occurring’. Not only is this a difficult argument to unravel from an evidence-based perspective, but also it causes confusion and delays remediation work, hindering efforts to reduce harmful exposures to children. An example of this situation is from Broken Hill, New South Wales, home to one of the world’s largest lead–zinc–silver ore body, which has been mined continuously for over 130 years. Environmental metal concentration and lead isotopic data from soil samples collected from across Broken Hill are used to establish the nature and timing of lead contamination. We use multiple lines of evidence to unravel a ‘miner’s myth’ by evaluating current soil metal concentrations and lead isotopic compositions, geological data, historical environmental assessments and old photographic evidence to assess the impacts from early smelting along with mining to the surface soils in the city. 相似文献
16.
David J. Suggett Ruy K. P. Kikuchi Marília D. M. Oliveira Saulo Spanó Rafael Carvalho David J. Smith 《Marine Biology》2012,159(7):1461-1473
Coral communities were examined from highly turbid near-shore marginal reefs of Abrolhos (Brazil) to test a paradigm previously developed from observations in clear water reefs; specifically, that coral photobiological properties follow a highly conserved linear relationship with optical depth (ζ) via preferential ‘non-photochemical’ over ‘photochemical’ dissipation of absorbed light energy. PAM flourometry in situ was used to examine the photobiology of the most dominant coral species throughout the platform surfaces and bases of Abrolhos’ characteristic ‘chapeir?es’ reef framework; however, none of the species consistently adhered to the ‘clear water paradigm’. PAM measurements further demonstrated that species conformed to two different strategies of non-photochemical energy dissipation: transient but relatively rapid for the two closely related endemic species (Mussismilia braziliensis and Mussismilia harttii) as opposed to more persistent for Montastrea cavernosa, Porites astreoides and Siderastrea stellata. Further experiments demonstrated that tolerance to anomalous stress amongst species did not correspond with the non-photochemical energy dissipation strategy present but was consistent with the relative dominance of species within the chapeir?es coral communities. 相似文献
17.
Kate Arnold Yvonne Pohlner Klaus Zuberbühler 《Behavioral ecology and sociobiology》2008,62(4):549-559
Some non-human primates produce acoustically distinct alarm calls to different predators, such as eagles or leopards. Recipients
respond to these calls as if they have seen the actual predator, which has led to the notion of functionally referential alarm
calls. However, in a previous study with free-ranging putty-nosed monkeys (Cercopithecus nictitans martini), we demonstrated that callers produced two acoustically distinct alarm calls to eagle shrieks and leopard growls, but both
alarm calls were given to both predators. We can think of two basic explanations for this surprising result, a methodological
and theoretical one. Firstly, acoustic predator models may not always be suitable to test alarm call behaviour in primates,
sometimes causing uncharacteristic behaviour. Secondly, referential alarm calling may not be a universal feature of primate
alarm call systems. Considering the methodological and theoretical importance of these possibilities, we conducted a follow-up
study using life-sized leopard, eagle, and human models on the same population and compared the resulting vocal responses
to those given to acoustic predator models. We compared the alarm call series given to each of these predator model types
and found a considerable degree of consistency suggesting that the mode of presentation did not affect anti-predator calling
strategies. However, evidence for audience effects on calling behaviour was inconclusive. While it appears that predator class
is reliably encoded by different call series types irrespective of the mode of presentation, observations of these same call
series given in non-predatory contexts indicate that predator class is unlikely to be the relevant organising principle underlying
the alarm-calling behaviour in this species. We conclude by offering an alternative, non-referential, account of the alarm-calling
system exhibited by this species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
Nathalie Hilmi Denis Allemand Sam Dupont Alain Safa Gunnar Haraldsson Paulo A. L. D. Nunes Chris Moore Caroline Hattam Stéphanie Reynaud Jason M. Hall-Spencer Maoz Fine Carol Turley Ross Jeffree James Orr Philip L. Munday Sarah R. Cooley 《Marine Biology》2013,160(8):1773-1787
Ocean acidification is increasingly recognized as a component of global change that could have a wide range of impacts on marine organisms, the ecosystems they live in, and the goods and services they provide humankind. Assessment of these potential socio-economic impacts requires integrated efforts between biologists, chemists, oceanographers, economists and social scientists. But because ocean acidification is a new research area, significant knowledge gaps are preventing economists from estimating its welfare impacts. For instance, economic data on the impact of ocean acidification on significant markets such as fisheries, aquaculture and tourism are very limited (if not non-existent), and non-market valuation studies on this topic are not yet available. Our paper summarizes the current understanding of future OA impacts and sets out what further information is required for economists to assess socio-economic impacts of ocean acidification. Our aim is to provide clear directions for multidisciplinary collaborative research. 相似文献
19.
Guoxia MA Jinnan WANG Fang YU Xiaomin GUO Yanshen ZHANG Chao LI 《Frontiers of Environmental Science & Engineering》2016,10(5):7
The Environmental Burden of Disease (EBD) approach for outdoor air pollution has been used to calculate premature deaths and average potential years of life lost attributable to air pollution in China over the past 10 years with differences between the North and the South of the country being analyzed. The results indicate that: (1) Between 2004 and 2013, annual premature deaths attributable to outdoor air pollution in China ranged from 350000 to 520000. In 2013, deaths resulting from air pollution in China represented 9.9% of the country’s total deaths. (2) In 2004, the average life expectancy of the Chinese population and the number of potential years of life lost (PYLL) attributable to air pollution was 69.6 and 1.85 years respectively as compared to 74.4 and 0.67 years respectively in 2013. (3) The number of the PYLL attributable to air pollution in the northern regions of China is found to be larger than that of the southern regions. The PYLL figures of the northern and southern regions in 2004 were 2.3 and 1.8 years, respectively, with a difference of 0.5 years, as compared to 1.4 and 0.7 years respectively with a difference of 0.7 years in 2013.
相似文献
20.
Miao Chang Lijuan Peng Shiwen Wang 《Frontiers of Environmental Science & Engineering》2008,2(2):172-177
The establishment of the environmental management system in the financial sector can be effectively promoted through the introduction of the environmental protection concept and its implementation by the financial sector. The impact of a sustainable development system on the sector is analyzed in this article from three aspects: environmental risk assessment, financing support for environmental protection projects, and financial services to environmentally friendly corporations and individuals. Influential factors on the development of the environmental management system in China’s financial sector are discussed from the perspective of various entities such as financial institutions, financial regulation authorities, environmental protection departments, corporations, and the public. It is pointed out that China’s financial sector is now in the transitional phase from a defensive attitude to a preventive attitude. Strengthening governmental guidance, the supervision of regulators as well as public awareness of environmental protection should be used to enhance the initiative in the development of the environmental management system in the Chinese financial sector. 相似文献