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571.
572.
A stakeholder driven process to reduce vulnerability to climate change in Hermosillo,Sonora, Mexico 总被引:1,自引:0,他引:1
Hallie Eakin Victor Magaña Joel Smith José Luis Moreno José Maria Martínez Osvaldo Landavazo 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):935-955
While there is a growing body of knowledge on potential impacts of climate change on water availability, there has been much
less empirical research on exploring the viability of particular adaptation options. The participation of stakeholders in
defining appropriate adaptation strategies is increasingly recognized as a critical element in the translation of climate
change impact research into effective actions to reduce future vulnerability, yet the process by which stakeholders are included
in such initiatives is not well-defined. This article presents the results of a pilot project in which a participatory approach
was employed to identify and evaluate adaptation options to climate change scenarios for Sonora’s capital city, Hermosillo.
In an iterative process, stakeholders representing different water users and managers in the city met to discuss climate change
scenarios, identify specific adaptation options, and evaluate a subset of options for possible future implementation. This
process enabled the focus of the investigation on those adaptations that addressed not only concerns with the potential future
impacts of climate change but also the immediate and pressing concerns about development patterns and water use in the city.
Two of the adaptations to climate change identified by stakeholders would also reduce energy demand. The simplicity of the
approach makes it a feasible model for adaptation initiatives in other regions of Mexico and in other countries in Latin America.
相似文献
Osvaldo LandavazoEmail: |
573.
Polychlorinated biphenyls (PCBs) elicit toxic effects in different species. PCBs undergo biotransformation by enzymes associated with the mixed functional oxidase system, such as cytochrome P450 (cyt P450), this biotransformation being sex-dependent. No other metabolic pathways are known, however, in connection with this process. Thus, the present study aims to evaluate the effects of waterborne PCBs at sublethal nominal concentrations (0.92 mg PCBs/L) on the black-fin goodeid Girardinichthys viviparus, an endangered fish native to the Valley of Mexico, as well as any sex differences related to PCB biotransformation. Eight-month-old adult fish born in the laboratory were exposed for 1, 2, 4, 8 and 16 days to half the LC(0) (calculated concentration at which no deaths occurred after 96 h) determined by an acute toxicity test. Specimens were sacrificed following exposure and the liver was used to evaluate different biomarkers: cyt P450 concentration and alcohol dehydrogenase (ADH) and ethoxyresorufin O-deethylase (EROD) activities. Results show sexual differentiation with regard to all biomarkers in both the control group and PCB-treated fish, with higher values found in males. The induction rate of cyt P450 remained constant throughout the study in males. In females, induction peaked on day 4, coinciding with maximum EROD activity, and fell significantly thereafter. EROD was lower in PCB-treated males than in the control group, but was greater in magnitude. ADH was significantly induced in both sexes from day 2 to day 16 of exposure. The highest response as compared to the control group occurred on day 8 in females. A correlation was found between ADH activity and exposure to PCBs. Three possible action mechanisms, operating either individually or concurrently, are proposed. 相似文献
574.
Temperature and salinity are important environmental factors affecting the normal functioning of marine animals, particularly animals such as sea urchins living in shallow waters and tide pools. Here, we evaluated the effect of different combinations of temperature and salinity on early embryos of the endemic New Zealand sea urchin Evechinus chloroticus. Animals were collected at Matheson’s Bay (36º18′17′′S; 174º47′51′′E) in north-eastern New Zealand in February 2013. Embryos were exposed to five salinities (29, 31, 34, 35 and 37 ppt) and two temperatures (18 and 21 °C) during the first 24 h of development. Low salinity (29 ppt) affected all parameters (fertilization, development rate, gastrulation and normal development), with ca. 50 % of embryos surviving at 29 ppt, whereas seawater temperature only affected development rate and gastrulation. An increase in temperature from 18 to 21 °C minimized the negative effect of low salinity (≤31 ppt) on development rate and gastrulation of E. chloroticus. Overall, the results of this study suggest that early embryos of E. chloroticus have developmental plasticity to withstand reductions in salinity up to 29 ppt; however, it is still unknown whether the surviving embryos will be able to complete larval development at low salinities, particularly whether the embryos and larvae are carried into extreme environments such as estuaries where salinity is even lower. Multistressor studies are very important for climate change research as multiple environmental factors will act together in the wild, having major consequences for development and recruitment of marine invertebrates. 相似文献
575.
Susana Martínez-Lera José Torrico Javier Pallarés Antonia Gil 《Journal of Material Cycles and Waste Management》2013,15(3):370-380
Plastic wastes have an especially high potential for use as alternative fuels, considering their high heating value and their large and stable availability. They could be used in electricity production based on gasification technologies, wherein electricity is produced in engines by means of the conversion of plastic wastes into a valuable gas. However, there are still some technical barriers to overcome before this technology can access the commercial stage, and further scientific research is needed to gain deeper understanding of the process and to be able to control and optimize it. This research presents the design and first experimental results of a bubbling fluidized bed gasifier conceived for the gasification of actual plastic residues. The experimental tests revealed that the selection and design of the reactor were adequate and proved some of the advantages of using plastic as a fuel, related in part to the absence of ashes and char. A valuable syngas over 5 MJ/m3 was generated, which contained a considerable fraction of methane as well as hydrogen and carbon monoxide as main combustible gases. The highest efficiency was achieved when the equivalence ratio was increased to 0.35, reaching 61 % in terms of cold gas efficiency and 66 % carbon conversion. 相似文献
576.
Marek Špinka Gudrun Illmann Jiří Haman Petr Šimeček Jitka Šilerová 《Behavioral ecology and sociobiology》2011,65(7):1447-1457
In domestic pigs, about 20% of nursing episodes end without milk transfer (non-nutritive nursings, NNNs). The function of
NNNs has not been satisfactorily explained yet. Here, we suggest that NNNs may be a part of an honest signaling system that
enables the sow to provide more frequent nutritive nursings (NNs) to those litters that can prove their need through exceptionally
frequent milk ejection solicitations. We further propose that the system is kept stable through the accelerating costs attached
to the solicitation in the form of NNNs. Based on this hypothesis, we predicted that (P1) with an increasing number of all
nursings (ALL = NNNs + NNs) the number of NNs should increase and that (P2) with an increasing number of ALL the proportion
of NNNs should increase. We tested P1 and P2 using a meta-analysis applied to data from eight studies that recorded the number
of NNs and NNNs in domestic pigs. We confirmed both P1 (NNs increasing with ALL) and P2 (proportion of NNNs increasing with
ALL). In combination, these results show a steeply accelerating cost of each additional nutritive nursing that piglets instigate.
This cost sets limits to the piglets' ability to solicit higher maternal investment through more frequent nursing solicitations. 相似文献
577.
Large amounts of phosphate ores with high concentrations of uranium were dumped by a phosphate plant into the Flix water reservoir
in the Ebre River, Catalonia, NE Spain. These phosphate wastes have been mixed over the years with effluents from other industries
as well as with the sediments of the river, resulting in a complex mixture of solid wastes and sediments. No investigations
on uranium speciation in such sediments were made because of the complexity of the sediments composition as well as the relatively
low uranium content. However, these studies are necessary in order to predict the release of the uranium to the river waters.
Here, we studied uranium speciation in sediments from two sampling points of the Flix water reservoir and at depths from 5
to 113 cm. We used room temperature time-resolved laser fluorescence spectroscopy and a three-step sequential extraction procedure
described by the Standards, Measurements, and Testing Programme of the European Union. We found that uranium was mainly present
in the sediment samples as meta-autunite [Ca(UO2)2(PO4)2·10–12H2O], whose low solubility will result in a low release of uranium to the river waters. In addition, we found that some uranium
was linked to sediments by forming surface complexes. We therefore made the first study of uranium speciation in the sediments
of the Flix water reservoir. 相似文献
578.
Jirí Gabriel Marina Capelari Petr Rychlovský Milan Krenželok František Zadražil 《毒物与环境化学》2013,95(1-4):141-146
The presence of Cd in substrate (wheat straw) strongly depressed the growth and mineralization of substrate by Agrocybe perfecta. Pleurolus ostreatoroseus was only slightly depressed and Pleurotus sp. CCB 068 increased degradation by the two highest Cd concentration. Mineralization rate of fungal substrate were increased by indigenous soil flora. However increase in Cd concentrations added to the soil depressed mineralisation of organic matter. Cadmium also affected the fruitbody yield and only Pleurotus sp. was able to fructify in high Cd concentrations. Translocation and accumulation of Cd in fruitbodies increased with the increase of Cd concentrations in substrate. 相似文献
579.
Reproductive trade-offs from mating with a successful male: the case of the tephritid fly Anastrepha obliqua 总被引:2,自引:1,他引:1
Diana Perez-Staples Martín Aluja Rogelio Macías-Ordóñez John Sivinski 《Behavioral ecology and sociobiology》2008,62(8):1333-1340
In lekking species, females may become sperm-limited when mating with sexually successful males, and this may be exacerbated
by a poor male diet. Polygynous males may also be limited by the amount of accessory gland products (AGPs) they can transmit
to females, which in turn may influence the females’ refractory period and longevity. Here, we tested the effect of male mating
history, larval and adult diet on copula duration, mating intervals, female fecundity, fertilisation success, life span and
likelihood to remate using sexually successful males of the lekking tephritid fly Anastrepha obliqua. Flies originated from either a native or exotic host fruit and were protein-fed or deprived. Male diet and larval host influenced
copula duration, while the time elapsed between matings was affected by the interaction of mating order and male adult diet.
Female fecundity was not influenced by female position in mating order or protein inclusion into the male diet. However, mating
order and male larval diet influenced female fertilisation success. Importantly, as males mated successively they were less
able to induce a refractory period on females, as the last females to mate with a male were more likely to remate and had
slightly longer life spans than the first females to mate with males. These results might be attributed to a decrease in male
AGPs with increasing male mating frequency. We discuss the role of conditional expression of male mating frequency with respect
to A. obliqua’s life history, the trade-off that females face when mating with a successful male, the effect of larval diet on adult sexual
performance and the possibility for sexual conflict to occur due to high male mating rates and fitness costs to females. 相似文献
580.
Assessment of Coastal Vulnerability Through the Use of GIS Tools in South Sicily (Italy) 总被引:1,自引:0,他引:1
This study assessed coastal erosion vulnerability along a 90-km sector, which included both erosional and accretionary beaches,
and different levels of human occupation. Two aerial photogrammetric flights were used to reconstruct coastal evolution between
1977 and 1999. During this period, extensive accretion was recorded updrift of human structures at harbors and ports, e.g.,
Scoglitti (105.6 m), Donnalucata (52.8 m), and Pozzallo (94.6 m). Conversely, erosion was recorded in downdrift areas, with
maximum values at Modica Stream mouth (63.8 m) and Point Castellazzo (35.2 m). Assessments were subsequently divided into
four categories ranging from “high erosion” to “accretion.” Several sources were examined to assess human activities and land
use. The latter was mapped and divided into four categories, ranging from “very high” to “no capital” land use. Subsequently,
coastal erosion vulnerability was assessed by combining land use categories with recorded coastline behavior. Results showed
“very high” to “high” vulnerability along 5.8% and 16.6%, respectively, of the littoral, while 20.9% and 56.7%, respectively,
was found to exhibit “medium” and “low/very low” vulnerability. A very good agreement between predicted coastal vulnerability
and coastal trend had been observed over recent years. Furthermore, several human structures and activities are located within
the “imminent collapse zone (ICZ)” which reached maximum values of 17.5 m at Modica Stream and 13.5 m at Point Braccetto. 相似文献