Comment on “Resuspension of urban soils as a persistent source of lead poisoning in children: A review and new directions” by Laidlaw M.A.S. and Filipelli G.M.     

John D. Bogden  Francis W. Kemp 《Applied Geochemistry》2009

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Two acoustic surveys of pelagic fish in Hawke Bay,New Zealand, 1980     

R. I. C. C. Francis 《新西兰海洋与淡水研究杂志》2013,47(3):375-389

The design and execution of two acoustic surveys of Hawke Bay in February and September/October 1980 are described. Though the resulting acoustic data were, for technical reasons, of limited value, they illustrate the information which may be drawn from acoustic surveys. Fish distributions may be rapidly mapped, not only by area, but throughout most of the water column and over time. Qualitative observations on fish distribution may be quantified. The estimation of variance in acoustic surveys is discussed in detail with particular emphasis on the problems of systematic surveys. The role of replicate observations is stressed. Coefficients of variation for relative fish density estimates from the two surveys probably lie between 5 and 30%.  相似文献   

Dissolved oxygen as an indicator of bioavailable dissolved organic carbon in groundwater   总被引：1，自引：0，他引：1  

Chapelle FH  Bradley PM  McMahon PB  Kaiser K  Benner R 《Ground water》2012,50(2):230-241

Concentrations of dissolved oxygen (DO) plotted vs. dissolved organic carbon (DOC) in groundwater samples taken from a coastal plain aquifer of South Carolina (SC) showed a statistically significant hyperbolic relationship. In contrast, DO-DOC plots of groundwater samples taken from the eastern San Joaquin Valley of California (CA) showed a random scatter. It was hypothesized that differences in the bioavailability of naturally occurring DOC might contribute to these observations. This hypothesis was examined by comparing nine different biochemical indicators of DOC bioavailability in groundwater sampled from these two systems. Concentrations of DOC, total hydrolysable neutral sugars (THNS), total hydrolysable amino acids (THAA), mole% glycine of THAA, initial bacterial cell counts, bacterial growth rates, and carbon dioxide production/consumption were greater in SC samples relative to CA samples. In contrast, the mole% glucose of THNS and the aromaticity (SUVA(254)) of DOC was greater in CA samples. Each of these indicator parameters were observed to change with depth in the SC system in a manner consistent with active biodegradation. These results are uniformly consistent with the hypothesis that the bioavailability of DOC is greater in SC relative to CA groundwater samples. This, in turn, suggests that the presence/absence of a hyperbolic DO-DOC relationship may be a qualitative indicator of relative DOC bioavailability in groundwater systems.  相似文献   

Whitefish wars: Pangasius, politics and consumer confusion in Europe   总被引：1，自引：0，他引：1  

David C. Little  Simon R. BushBen Belton  Nguyen Thanh PhuongJames A. Young  Francis J. Murray 《Marine Policy》2012,36(3):738-745

Rapid growth in production of the farmed Vietnamese whitefish pangasius and its trade with the European Union has provoked criticism of the fish's environmental, social and safety credentials by actors including WWF and Members of the European Parliament and associated negative media coverage. This paper reviews the range of claims communicated about pangasius (identified as a form of mass mediated risk governance), in light of scientific evidence and analysis of data from the EU's Rapid Alert System for Food and Feeds food safety notification system for imported seafood. This analysis shows pangasius to be generally safe, environmentally benign and beneficial for actors along the international value chains that characterise the trade. The case is made that increasingly politicised debates in Europe around risk and uncertainty are potentially counterproductive for EU seafood security and European aquaculture industry, and that the trade in pangasius can contribute to sustainable seafood consumption in a number of ways. Transparent evidence-based assessment and systems for communicating complex issues of risk for products such as pangasius are required in order to support continuance of fair and mutually beneficial trade.  相似文献   

The Riverscape and the River - By Sylvia M Haslam     

Robert A  Francis 《The Geographical journal》2008,174(3):290-290

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The evolution of the electronics industry on Batam Island (Riau Islands Province,Indonesia): an evolutionary trajectory contributing to regional resilience?     

Leo van Grunsven  Francis E. Hutchinson 《GeoJournal》2017,82(3):475-492

While extensively studied in the 1990s, research on the electrical and electronics (E&E) industry in Singapore and the proximate areas of Indonesia has dwindled. Focusing on the E&E sector in the island of Batam (Riau Islands Province, Indonesia), we examine the industry’s recent evolution, in particular its ‘robustness’—its durability and capacity to adapt to adverse events. As to the explanatory factors accounting for its robustness, we evaluate the role of agency as opposed to conventional approaches that focus on structure. Our findings show that, in Batam, the E&E industry’s robustness has started to suffer. While there is evidence that structural factors are at work, we argue that agency in the form of institutionally-embedded perspectives and behaviour of actors at the sub-national level also plays a role. Because the promotion of economic diversification through investment in new sectors is easier and more lucrative than upgrading and deepening of firm capabilities in existing sectors, agents privilege the former at the cost of the latter. At the end of the day, regional resilience is undermined, rather than reinforced as evinced by the recent atrophy of Batam’s E&E industry.  相似文献   

Species composition and gear characteristics of the <Emphasis Type="Italic">Macrobrachium</Emphasis> fishery of the Cross River Estuary,Nigeria     

Francis M. Nwosu 《中国海洋大学学报(英文版)》2010,9(1):71-75

The Cross River Estuary, Nigeria, is an important shrimping area for artisanal fishermen of the coastal communities. The multi-species Macrobrachium fishery is exploited with three main gears, namely beach seine, push net and trap. Studies on species composition of this fishery recorded thirteen shrimp species, one swimming crab (Callinectes amnicola) and two fish species (Eleotris sp. and Pellonula leonensis). The shrimp species identified included Macrobrachium macrobrachion (83.39% and 55.69% by number and weight, respectively), M. vollenhovenii (9.66% and 37.18%), M. equidens (3.8% and 2.87%), juveniles-sub-adults of Penaeus notialis (1.11% and 1.3%), M. dux, M. felicinum, Palaemonetes africanus, Palaemon maculatus, Palaemon elegans, Desmocaris sp., Leander sp., Nematopalaemon hastatus and Alpheus pontederiae. While the selectivity index for trap was 0.25, beach seine and push net had a lower index of 0.063. The results present the first comprehensive and representative report for the Estuary shrimp fishery and will assist in the management of the biodiversity of this ecosystem.  相似文献   

Effects of Hydrogel Amendment to Different Soils on Plant Available Water and Survival of Trees under Drought Conditions     

Hillary Agaba  Lawrence Justus Baguma Orikiriza  John Francis Osoto Esegu  Joseph Obua  John David Kabasa  Aloys Hüttermann 《洁净——土壤、空气、水》2010,38(4):328-335

The effect of super absorbent polyacrylate (SAP) hydrogel amendment to different soil types on plant available water (PAW), evapotranspiration and survival of Eucalyptus grandis, Eucalyptus citriodora, Pinus caribaea, Araucaria cunninghamii, Melia volkensii, Grevillea robusta, Azadirachta indica, Maesopsis eminii and Terminalia superba was investigated. The seedlings were potted in 3 kg size polythene bags filled with sand, loam, silt loam, sandy loam and clay soils, amended at 0 (control), 0.2 and 0.4% w/w hydrogel. The tree seedlings were allowed to grow normally with routine uniform watering in a glass house set up for a period of eight weeks, after which they were subjected to drought conditions by not watering any further. The 0.4% hydrogel amendment significantly (p < 0.05) increased the PAW by a factor of about three in sand, two fold in silt loam and one fold in sandy loam, loam and clay soils compared to the control. Similarly, the addition of either 0.2 or 0.4% hydrogel to the five soil types resulted in prolonged tree survival compared to the controls. Araucaria cunninghammi survived longest at 153 days, while Maesopsis eminii survived least (95 days) in sand amended at 0.4% after subjection to desiccation. Evapotranspiration was reduced in eight of the nine tree species grown in sandy loam, loam, silt loam and clay soils amended at 0.4% hydrogel. It is probable that soil amendment with SAP decreased the hydraulic soil conductivity that might reduce plant transpiration and soil evaporation.  相似文献   

Configuring high frequency radar observations in the Southern Chukchi Sea   总被引：1，自引：1，他引：0  

Gleb Panteleev  Max Yaremchuk  Oceana Francis  Takashi Kikuchi 《Polar Science》2013,7(2):72-81

In recent years, monitoring offshore surface circulation in the Arctic Ocean with high frequency radars has become an issue of increasing practical importance. In this study, radar positions are optimized by minimizing the reconstruction errors of the surface currents in the Southeastern Chukchi Sea. By means of an adjoint sensitivity technique it is shown that in the case of a pair of radars, their optimal (i.e. most favorable) location is at Kivalina, a settlement near the strongest outflow of the Alaskan Coastal Current from the monitored domain. The least favorable location is at Shishmaref, a settlement near relatively weak inflow into the region as observed from the coast. However, if two pairs of radars are available, the best locations are Kivalina and Shishmaref. The results are verified using observational system simulation experiments (OSSEs) performed in the framework of a 4-dimensional variational assimilation of simulated radar observations into a numerical model. It is shown that correct specification of the first guess solution is of primary importance for obtaining realistic results from both adjoint sensitivity analysis and OSSEs. This emphasizes the necessity of obtaining accurate high resolution climatologies for future ice-free offshore regions in the Arctic.  相似文献   

Terra Vibrata: Some Observations on the Dynamics of Soil Landscapes     

Francis D. Hole 《自然地理学》2013,34(2):175-185

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