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31.
The enhanced solubility of petroleum-derived compounds in humic acid solutions is the basis for a new groundwater remediation technology. In this unique pilot-scale test, a stationary contaminant source consisting of diesel fuel was placed below the water table in a model sand aquifer (1.2 x 5.5 x 1.8-m deep) and flushed with water at a flow rate of 2 cm/h over 5 years. At 51 days, laboratory grade humic acid was added to the water and maintained at a level of approximately 0.8 g/l. The addition of humic acid had only a small impact on the aqueous transport of the BTEX components, which were rapidly dissolved from the diesel, but had a large effect on the flushing of PAHs, including methylated naphthalenes (MNs). Binding to aqueous humic acid enhanced the solubilization of MNs two- to tenfold. During aqueous transport, biodegradation of the BTEX and PAHs occurred, limiting the lateral and longitudinal extent of the diesel contaminant plume in the model aquifer. It appears that through enhanced solubilization, the overall biodegradation rate of the MNs was increased. As the various MNs were depleted from the diesel source, the MN plume shrank and then disappeared.  相似文献   
32.
Social groups in mammals are often based on overlapping generations of philopatric females, yet few researchers have examined fitness consequences of associations between females and their daughters. We examined survival and reproductive consequences of sharing a natal site with one's mother or daughter in wild bushy-tailed woodrats (Neotoma cinerea). Bushy-tailed woodrats reside on discrete rocky outcrops, and females tend to spend their entire reproductive life on their natal outcrop. Mothers and daughters that co-existed on the natal outcrop were closely associated in space. Juvenile females were more likely to survive their first winter to become breeding yearlings at their natal site if their mother was also present at the natal site during the winter. Juveniles survived equally well with or without their mother where densities of adult females were experimentally reduced, suggesting that females enhance their daughter's survival by facilitating their access to limited resources. Yearling females exhibited no reproductive costs from association with their mothers at the natal site during the breeding season; in fact, yearlings that bred at the natal site simultaneously with their adult mothers tended (P = 0.07) to experience fewer reproductive failures than did those that bred in the absence of their mothers. Mothers did not experience any detectable costs when sharing a natal site with a daughter. We conclude that bushy-tailed woodrats exhibit stable, fitness-enhancing associations among mothers and their philopatric daughters.  相似文献   
33.
Cross-cultural differences exist in prenatal diagnosis and abortion for fetal anomaly, stemming from variations in laws, reimbursement policies, litigation, physicians' decision-making authority, and attitudes toward the prevention of handicaps. The first part of this paper discusses such differences in France and the U.S. The second part describes a survey of practising obstetricians in Paris, designed to assess (1) their attitudes toward pregnancy termination for various conditions, (2) their concern about fetal viability, (3) their desire for diagnostic certainty before justifying a late abortion, and (4) their perceived role in such decision-making. Among the 64.8 per cent (N = 217) who responded, the majority supported third-trimester termination (TTT) for diseases such as spina bifida, trisomy 21 , microcephaly, and Duchenne muscular dystrophy; 30–59 per cent supported TTT for cystic fibrosis and sickle cell disease; and 22–29 per cent supported TTT for haemophilia, tetralogy of Fallot, limb amputation, and Turner and Klinefelter syndromes. Obstetricians who approved of abortion across trimesters were less concerned with the certainty of diagnosis than its severity, more likely to think that abortion ought to be the parents' choice, but more likely to report making a recommendation to the parents about whether to abort a fetus. Such permissive abortion attitudes might imply more permissive prenatal diagnosis and abortion practice among Parisian obstetricians, which might lead to increased migration of patients from other E.C. countries. Cross-cultural variation in obstetric practice suggests that an international registry of pregnancies terminated for medical reasons, enabling further study of this issue, would be valuable.  相似文献   
34.
Participatory modeling is increasingly recognized as an effective way to assist collective decision-making processes in the domain of natural resource management. This article introduces a framework for evaluating projects that have adopted a participatory modeling approach. This evaluation framework—known as the “Protocol of Canberra”—was developed through a collaboration between French and Australian researchers engaged in participatory modeling and evaluation research. The framework seeks to assess the extent to which different participatory modeling initiatives not only modify perceptions among and interactions between participants, but also contribute to collective decision-making. The article discusses the development of the framework and it’s application to three case-studies, two from Australia and one from the Pacific Island of the Republic of Kiribati. The article concludes with some comments for future use of the framework in a range of participatory modeling contexts.  相似文献   
35.
In the 1990s, a cold water event was associated with drastic changes in the biology of Newfoundland capelin (Mallotus villosus), the key forage fish in the north Atlantic. In contrast to studies conducted prior to the 1990s, we report a lower maximum potential fecundity (7,616–42,880) and a weak relationship between fecundity and body size based on fecundity of 218 female capelin (12.3–16.9 cm) collected within two coastal regions of Newfoundland in 2008 and 2009. Further, using forward stepwise multiple regression and hierarchical partitioning, we conclude that life history traits (mass, somatic mass and egg size) and condition indices (Fulton’s K, Hepatosomatic Index and Gonadosomatic Index) are not appropriate proxies for fecundity of capelin in our study area. Hierarchical partitioning revealed that egg size and condition indices suppress the variance in fecundity explained by other factors. Based on the insight it provides into the influence of traits on fecundity, we suggest that hierarchical partitioning is a powerful analysis technique that could be used in further investigations.  相似文献   
36.
Probability-based designs reduce bias and allow inference of results to the pool of sites from which they were chosen. We developed and tested probability-based designs for monitoring marine rocky intertidal assemblages at Glacier Bay National Park and Preserve (GLBA), Alaska. A multilevel design was used that varied in scale and inference. The levels included aerial surveys, extensive sampling of 25 sites, and more intensive sampling of 6 sites. Aerial surveys of a subset of intertidal habitat indicated that the original target habitat of bedrock-dominated sites with slope ≤30° was rare. This unexpected finding illustrated one value of probability-based surveys and led to a shift in the target habitat type to include steeper, more mixed rocky habitat. Subsequently, we evaluated the statistical power of different sampling methods and sampling strategies to detect changes in the abundances of the predominant sessile intertidal taxa: barnacles Balanomorpha, the mussel Mytilus trossulus, and the rockweed Fucus distichus subsp. evanescens. There was greatest power to detect trends in Mytilus and lesser power for barnacles and Fucus. Because of its greater power, the extensive, coarse-grained sampling scheme was adopted in subsequent years over the intensive, fine-grained scheme. The sampling attributes that had the largest effects on power included sampling of “vertical” line transects (vs. horizontal line transects or quadrats) and increasing the number of sites. We also evaluated the power of several management-set parameters. Given equal sampling effort, sampling more sites fewer times had greater power. The information gained through intertidal monitoring is likely to be useful in assessing changes due to climate, including ocean acidification; invasive species; trampling effects; and oil spills.  相似文献   
37.
Gail K. Davoren 《Marine Biology》2013,160(12):3043-3058
Investigations of distributional and density patterns of marine predators often reveal areas where high abundances of one or many species overlap in space and time (‘biological hotspots’); however, mechanisms underlying hotspot formation are often unclear, leading to difficulties determining spatial and temporal boundaries of protected areas. On the northeast Newfoundland coast, I previously described annually persistent aggregations of a key forage fish species, capelin (Mallotus villosus): (1) two pre- and post-spawning staging areas in deep (>150 m) bathymetric channels, (2) a cluster of four persistently used demersal spawning sites (17–40 m), and (3) a coastal migratory route (<50 m). Through at-sea surveys repeated over 8 years (2000–2003, 2007, and 2009–2011), I show that the majority of predator hotspots identified were spatially associated with (i.e., within 10 km) these persistent capelin areas for breeding seabirds (common murre: 85.2 ± 4.6 %; northern gannet: 66.9 ± 6.6 %), overwintering seabirds (great and sooty shearwaters: 88.0 ± 6.9 %), and baleen whales (humpback, minke, and fin whales: 86.8 ± 8.6 %). Most predator hotspots were closer to the spawning (3.8–14.0 km) relative to the staging areas (13.1–27.6 km), especially for murres and shearwaters. Interspecific differences were attributed to variation in maximum dive depths and dietary preferences. Predators only aggregated within the spawning area, while capelin were spawning, suggesting that interannual variation in association with predator and capelin hotspots was attributed to variation in survey timing relative to capelin spawning. As these areas of persistent capelin are bound by static bathymetric and large-scale oceanographic features and can be delimited in time based on the capelin spawning period, they may be important candidate areas for protection.  相似文献   
38.
Project RENEWAL is an innovative new environmental business project taking place in New Jersey. Project RENEWAL stands for Resource Efficiency Network to Eliminate Waste and Liability. The purpose of this project is to investigate and promote the linkages between ecology, technology, and business economics for the benefit of the economy and the environment. This is a collaborative effort, initially focused on equipment and inventory assets, between the business and environmental communities in order to explore new ways to increase business efficiency and profitability and also benefit the environment. Participants in the project include representatives from industry, consulting, local and state government, environmental agencies, trade groups and academia. This article will outline the background and initial framework of Project RENEWAL's initiatives. (The authors are open to comments, suggestions, criticism, and most importantly input from others who share their vision and are willing to cooperatively accelerate the change process).  相似文献   
39.
ABSTRACT: Results from five different test systems, which include a wide range of optical conditions, indicate credible estimates of the values of the absorption and scattering coefficients can be calculated from paired measurements of Secchi disc transparency and the diffuse attenuation coefficient. The diagnostic utility of the estimates in identifying components and processes that regulate light penetration is demonstrated for three different cases. The simple estimation technique is valuable in the analysis of existing data bases that lack comprehensive optical information to develop and evaluate alternate models for light penetration and to establish the experimental needs of future field programs to support lake management efforts.  相似文献   
40.
In Ireland, conversion of biodegradable farm wastes such as pig manure spent mushroom compost and poultry litter wastes to pelletised fertilisers is a desirable option for farmers. In this paper, results obtained from the composting of pig waste solids (20% w/w) blended with other locally available biodegradable wastes comprising poultry litter (26% w/w), spent mushroom compost (26% w/w), cocoa husks (18% w/w) and moistened shredded paper (10% w/w) are presented. The resulting 6-mo old 'mature' composts had a nutrient content of 2.3% total N, 1.6% P and 3.1% K, too 'low' for direct use as an agricultural fertiliser. Formulations incorporating dried blood or feather meal amendments enriched the organic N-content, reduced the moisture in mature compost mixtures and aided the granulation process. Inclusion of mineral supplements viz., sulphate of ammonia, rock phosphate and sulphate of potash, yielded slow release fertilisers with nutrient N:P:K ratios of 10:3:6 and 3:5:10 that were suited for amenity grasslands such as golf courses for spring or summer application and autumn dressing, respectively. Rigorous microbiological tests carried out throughout the composting, processing and pelletising phases indicated that the formulated organo-mineral fertilisers were free of vegetative bacterial pathogens.  相似文献   
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