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181.
This paper focuses on growth feasibility in an era of increasing scarcity of fossil fuels. A stylised dynamic model illustrates the implications of investing in smooth technological progress in the field of renewable energy. Positive rates of GDP growth sustained by fossil fuels entail, on the one hand, more income available for R&D in renewable energy sources, and on the other, an acceleration of the exhaustible resource depletion time. Our model explores such a trade-off and highlights the danger of high growth rates. Policies should target low growth rates, stimulate investment in alternative energy sources and discourage consumption growth. 相似文献
182.
Ronaldo Sousa Ângela Amorim Carina Sobral Elsa Froufe Simone Varandas Amílcar Teixeira Manuel Lopes-Lima 《Environmental management》2013,52(5):1230-1238
An important population of the critically endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) was surveyed at the edge of its southern distribution (River Paiva, Portugal). Although an earlier study suggested that this population had a very low number of individuals (<500), a narrow distribution, and was mainly comprised by old specimens our data contradict these findings. Our assessment estimated a population with probably more than 5,000 individuals distributed across 80 km of the river length. From the 32 sites surveyed, 19 contained M. margaritifera with higher abundances verified in the middle and upper parts of the river (a maximum of 78 ind. per 100 m of river stretch was recorded). The pearl mussels showed a clear preference for areas near the banks, in shallow water, sandier and gravel sediments, and a high degree of riparian vegetation cover. The population structure was skewed with a very high percentage of large (and old) animals but 3.7 % of the individuals collected were juveniles (<60 mm in length); therefore, this population can be considered functional. Environmental characterization indicated that this river is still in excellent or good condition although some areas showed deterioration due to discharge of domestic effluents. The main conservation requirements of M. margaritifera in the River Paiva include maintaining the water quality (and if possible stopping the discharge of domestic effluents), increasing riparian vegetation cover, removing several weirs to increase connectivity, and increasing trout density. 相似文献
183.
Charles R. Warren Carolyn Lumsden Simone O'Dowd Richard V. Birnie 《Journal of Environmental Planning and Management》2005,48(6):853-875
The wind energy debate represents a new kind of environmental controversy which divides environmentalists of different persuasions who attach contrasting priority to global and local concerns. Case studies of public attitudes towards existing and proposed windfarm developments in Scotland and Ireland are used to test three counter-intuitive hypotheses derived from previous attitudinal research. These are: (a) that local people become more favourable towards windfarms after construction; (b) that the degree of acceptance increases with proximity to them; and (c) that the NIMBY syndrome(not-in-my-back-yard) does not adequately explain variations in public attitudes. All three hypotheses are supported by this study. Large majorities favour wind power development in principle and in (local) practice. Although some aspects of NIMBY attitudes exist, the surveys reveal an ‘inverse NIMBY’ syndrome, whereby those with windfarms in their ‘backyard’ strongly support the technology. The research endorses the view that aesthetic perceptions, both positive and negative, are the strongest single influence on individuals' attitudes towards wind power projects. Comparison of the current institutional factors driving wind energy development with those during earlier eras of hydro-power development and large-scale afforestation emphasizes the need for strategic planning guidance. The potential for using a planning-led approach to windfarm developments by adopting ‘Indicative Windfarm Strategies’ is discussed. 相似文献
184.
Pregnancy outcome after transcervical cvs with a flexible biopsy forceps: Evaluation of risk factors
The pregnancy outcome of 1936 women who had transcervical chorionic villus sampling (CVS) with a flexible biopsy forceps was evaluated. Follow-up until 4 weeks after delivery was 99.4 per cent. Various patient- and procedure-related risk factors for spontaneous loss (fetal or neonatal death) were analysed using stepwise logistic regression analysis. The overall spontaneous loss rate was 4.5 per cent. Factors found to be significantly associated with spontaneous loss were quantity of villi ≤ 15 mg (relative risk (RR) 2.13), a history of first-trimester miscarriage (RR 1.87) or delivery between 16 and 27 weeks (RR 3.87), cervical culture positive for anaerobes (RR 4.52) or group B streptococcus (RR 3.62), post-procedural bleeding >3 days (RR 1.99), and multiple insertions (RR 2.64). Significant differences in loss rates between individual operators were found. A learning effect was not present. There were no infants born with terminal transversal limb anomalies in our series. 相似文献
185.
Simone?Ciuti Sara?Davini Siriano?Luccarini Marco?ApollonioEmail author 《Behavioral ecology and sociobiology》2004,56(6):552-564
Large-scale spatial segregation was assessed by means of radio-telemetry in 48 fallow deer studied for 4 years. Three hypotheses have traditionally been used to explain sexual segregation: (1) the predation risk hypothesis, (2) the forage selection hypothesis, (3) the activity budget hypothesis. The first of these seems to be a valid explanation of large-scale segregation in fallow deer at San Rossore, where the use by the two sexes of areas characterized by intense anthropic disturbance, during the day, was compared with other areas not affected by human pressure. Males showed a high use of disturbed areas, both during the day and the night, with the exception of the rutting period, when they reached more remote areas to mate. Females frequented disturbed areas only during the night, with the exception of the birth period, when sexual segregation peaked because females never used these areas, not even during the night. The forage selection hypothesis was invalid on a large scale, considering that no differences between the degree of day and night sexual segregation were to be expected. However, the predation risk hypothesis seems not to be a valid explanation of small-scale sexual segregation, when further subdivisions of disturbed areas are considered, because sexes proved to be segregated also during the night in the area they both used. This emphasizes both the importance of scale in understanding ecological processes, since a combination of many different factors may be responsible for the evolution of sexual segregation in ungulates, and the importance of human pressure in influencing deer behaviour.Communicated by T. Czeschlik 相似文献
186.
187.
Simone Poddighe Teun Dekker Antonio Scala Anna Maria Angioy 《Die Naturwissenschaften》2010,97(9):827-835
The nasal botfly Oestrus ovis (Diptera, Cyclorrhapha: Oestridae) is a myiasis-causing insect species, which affects the health of sheep, goats and humans.
Gravid females are viviparous and larviposit into the animal’s nostrils. Host-searching and larvipositing flies are visually
guided and influenced by climatic conditions, whereas olfaction seemed to play no role in this process. However, here, we
show that the antennae of adult O. ovis female flies are relatively small but well developed and inhabited by several types of olfactory sensilla. Further, we show
that the antennal lobes of this species receive input from antennal afferents and consist of a clearly defined glomerular
organisation. We also give the first evidence of the fly’s ability to detect several synthetic odour compounds. Our findings
provide a morpho-functional basis for future investigations on olfactory-mediated behaviour of this insect pest. 相似文献
188.
Mirna H. R. Seleghim Simone P. de Lira Patrícia T. Campana Roberto G. S. Berlinck Marcio R. Custódio 《Marine Biology》2007,150(5):967-975
Ascidians are a notable source of nitrogen-bearing secondary metabolites with a wide range of biological activities. Although
many biologically active compounds have been isolated from ascidians, it is often unclear whether the animal or associated
microbial symbionts such as bacteria or fungi are the true biosynthetic source of the metabolites. We have addressed the question
of the biosynthetic source of the alkaloids granulatimide and isogranulatimides by localizing these compounds within the ascidian.
In this work, we demonstrate that granulatimide is stored in Didemnum
granulatum tunic bladder cells. Analysis by confocal fluorescence microscopy at the granulatimide emission range indicated the presence
of fluorescent cells as highly vacuolated cells found dispersed in the ascidian tunic. Since this is the most exposed ascidian
tissue, it is possible that these alkaloids may have a protective role, either as sunscreens and/or as feeding deterrents. 相似文献
189.
We questioned the different interpretations of ecological sexual segregation from a novel perspective, i.e., by carrying out
diverse temporal and spatial scale analyses within a long-term study (1984–2003). Thus we combined spatial (small/large) and
temporal (small/large) scale analyses to identify the factors generating sexual segregation in fallow deer in San Rossore,
Italy. The study site was divided into an eastern sector characterized by human disturbance (DS) and a western undisturbed
sector (US). According to census data, human presence increased in DS from 1984, and while females gradually abandoned it,
males remained—thus supporting the predation risk hypothesis (large spatial and temporal scale)—and actually increased their
presence in DS, where they seemingly benefited from a lower female density. This supported the indirect competition hypothesis.
The analysis of data on a large temporal and small spatial scale confirmed that intersexual competition, in particular for
grass, was higher in a crowded pasture in US. Observations by means of radio-telemetry of 23 adult females and 25 adult males
(1997–2001, reduced temporal and large spatial scale) showed that large scale segregation was relevant during the day and
disappeared at night, when disturbance was absent and also the females reached DS. This also supported the predation risk
hypothesis. Moreover, sexes showed different habitat choices inside DS at night, thus supporting the forage selection hypothesis
(small spatial and temporal scale). In conclusion, failure to address the whole set of combinations of spatial and temporal
scale analyses would have led to monocausal explanations of ecological sexual segregation. 相似文献
190.
Francesco Paladini de Mendoza Simone Bonamano Giuseppe Stella Monica Giovacchini Dario Capizzi Fulvio Fraticelli Sergio Muratore Calogero Burgio Sergio Scanu Maximo A. Peviani Marco Marcelli 《Journal of Coastal Conservation》2016,20(1):13-29
The present work proposes a siting process for the detection of a suitable site for wave energy exploitation. The choice of a suitable site is based on the good agreement between energy availability, environmental sustainability, and equipped facilities to exploit wave energy. The case study in the northern Latium coast is explicative because in this area there are several activities that affect marine ecosystems, and the introduction of renewable energies promote the reduction of anthropic pressures. The nearshore wave power is studied through the numerical wave model (CMS-Wave), and available wave buoys along the coast were used to compare numerical results. In correspondence with Civitavecchia harbour, the largest nearshore wave energy was found; the large depth in front of the breakwater allows to conserve a great part of offshore wave power, with an average dissipation rate of 10 % less than offshore, with mean annual available wave energy of 25.4 MWh/m and seasonal fluctuation of 5.4 MWh/m. This area appears to be an optimal site for nearshore and shoreline wave energy device tests and installations, for energy availability (intermediate level respect Mediterreanean Sea), low potential environmental impact, easier accessibility, and policy oriented towards a larger sustainability of harbour activities. 相似文献