Post-revanchist cities?     

Geoff DeVerteuil 《Urban geography》2013,34(7):1055-1061

This intervention focuses on how national-level rhetoric aimed at impugning “others” has thrived of late, but how concomitantly 1990s-style urban revanchism has faded in cities that were once punitive crucibles against the homeless. Using Los Angeles as case study, I argue that the recent trend has been to grudgingly support the homeless, increasingly via taxpayer initiatives, leading to a potential but stymied post-revanchist city. If the spirit of revanchism remains, it is through the persistent NIMBY opposition to housing the homeless.  相似文献   

Diet and dietary variation of New Zealand hoki Macruronus novaezelandiae     

AM Connell  J Forman 《新西兰海洋与淡水研究杂志》2013,47(4):289-308

The diet of hoki was determined from examination of stomach contents of 1992 fish of 26–112 cm total length (TL) sampled at depths of 209–904m on Chatham Rise, New Zealand, from summer research trawl surveys and seasonal commercial fishing trawls, during 2004–2008. Prey was predominantly euphausiids, mesopelagic fishes and natant decapods. Multivariate analyses using distance-based linear models, non-parametric multi-dimensional scaling and similarity percentages indicated that the best predictors of diet variability were the position of the fish in relation to the subtropical front (STF), fish size and longitude. Pasiphaeids were more important to the north of the STF, and sternoptychid fishes and euphausiids more important in the STF convergence area. Euphausiids and sternoptychid fishes were important for smaller hoki (26–55 cm TL), myctophid fishes and natant decapods for larger hoki, and macrourids for the largest hoki (>84 cm TL). The longitudinal effect was characterised by pasiphaeids, euphausiids and sternoptychids to the west, and myctophids in the centre of Chatham Rise. Feeding activity was analysed using generalised additive models, and was found to vary with time of day, sample source (research or commercial), longitude, hoki size and depth. The variability in diet suggested hoki forage opportunistically within their preferred habitat and biological limits.  相似文献   

Airborne Laser Sensing of Scottish Coastal Waters     

Grigorii Kokhanenko  Geoff Ludbrook  Ivan Penner  Vitalii Shamanaev 《Marine Geodesy》2013,36(4):195-207

An Nd:YAG-based airborne lidar system has been used to measure the optical properties of littoral waters off the northwest Scottish coast. The small-scale structure of subsurface scattering layers was also investigated. Methods of solving the Lidar Sensing Equation in the single scattering approximation are described and the values of the derived extinction indices presented. The extinction index averaged over a series of five flights to the northeast of the Gulf Stream was k = 0.224 m -1 with a standard deviation of 0.212 m -1 . Further, it was demonstrated that, in coastal waters, optical inhomogeneities with dimensions between 50 m and 200 km obey the power law Sp k ~ k -P with the parameter P close to two. In turbid or transparent areas, the water extinction index can change by several tenths of a percent with respect to the surrounding water mass. This suggests that the observed nonmonotonic behavior of the power spectra of the water extinction index fluctuations is caused by the outer scale of turbulence, in particular, by the bottom depth at the measurement site.  相似文献   

The new blackbirds? Vanuatu guestworkers in New Zealand     

Jeremy Hammond  John Connell 《New Zealand geographer》2009,65(3):201-210

An agricultural guestworker scheme for Pacific island states began in New Zealand in 2007 to remedy domestic agricultural labour shortages. Vanuatu was one of the first countries to take advantage of the scheme. After a pilot venture in 2007 greater numbers of workers were recruited in 2008. In Tanna, the recruits, though mainly male, represented a cross‐section of the population. Their objectives were income generation for education fees, house building and eventually small business development. Early returnees acquired significant capital and met some of these objectives. The scheme has benefited both countries and the first generation of guestworkers.  相似文献   

Burial and turbulent transport by bioturbation: a 27‐year experiment in southeast Australia     

Paul J. Richards  Geoff S. Humphreys 《地球表面变化过程与地形》2010,35(7):856-862

In order to assess the net effect and relative importance of geomorphic processes at two natural woodland sites in southeast Australia, 100 small tiles were placed on the soil surface in 1979 and their movement was monitored over the course of nearly three decades. Rates of tile burial and other tile displacement were considerable but also markedly random, being largely inconsistent with expected patterns of displacement by orthodox creep and rainwash processes. This included substantial upslope displacement and burial depths that ranged from zero to 5 cm. We suggest that such turbulent transport in the topsoil has mostly been caused by the direct and indirect transfer of soil and clasts by animals and plants (i.e. bioturbation). In addition to direct evidence of biota interacting with tiles, the effectiveness of bioturbation at our sites has been well established and the overall tile burial rate of 0·25 to 0·4 mm yr^?1 is comparable to rates of surface mounding. Patterns of tile movement are generally consistent with soils‐geomorphic theory regarding the biomantle and bioturbation‐driven stonelayer formation, and provide further evidence that soil transfer and slope movement, in many situations, are markedly random and complex processes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Small island sustainability in the Pacific: Introduction to the special issue     

Katherine V. Gough  Tim Bayliss-Smith  John Connell  Ole Mertz 《Singapore journal of tropical geography》2010,31(1):1-9

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Lake Tahoe vs. Lake Kinneret phytoplankton: comparison of long-term taxonomic size structure consistency     

Yury Kamenir  Monika Winder  Zvy Dubinsky  Tamar Zohary  Geoff Schladow 《Aquatic Sciences - Research Across Boundaries》2008,70(2):195-203

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Use of exposure time and life expectancy in models for toxicity to aquatic organisms     

Connell D  Yu J 《Marine pollution bulletin》2008,57(6-12):245-249

The exposure time is a variable which is usually not incorporated into models for toxicity. However, with persistent organic pollutants (POPs) exhibiting a nonspecific mode of action and lipophilic properties this variable can be modeled by the usage of the internal concentrations as a measure of the toxicity with fish. The bioconcentration process with fish is a relatively well understood and predictable process which allows the calculation of the internal lethal concentration. When the exposure time is relatively short the critical internal lethal concentrations are relatively constant for the group of POPs whereaas the LC50 measured in the ambient water is quite variable. When the exposure time is relatively long, results on the measurement of the critical internal concentration with fish over different exposure times has demonstrated that the internal lethal concentration falls with increasing exposure times in a consistent and predictable manner. This reduction in life expectancy can be described in a model which can be used to estimate the critical internal concentration for any exposure time. It also provides information useful in assessing the risk to fish and potentially other species due to the occurrence of residues of POPs in natural aquatic systems. It is suggested that these relationships can be extended to other groups of organisms and chemicals.  相似文献   

Synergistic effects of diuron and sedimentation on photosynthesis and survival of crustose coralline algae     

Harrington L  Fabricius K  Eaglesham G  Negri A 《Marine pollution bulletin》2005,51(1-4):415-427

Effects of short-term exposure to sedimentation and diuron, separately and in combination, on the photophysiology and survival of crustose coralline algae (CCA) were examined in controlled time-course experiments, using pulse-amplitude modulation (PAM) chlorophyll fluorometry. These experiments indicated that the effects of sediments and diuron, when applied in isolation, were often reversible, with recovery time dependent upon sediment type and diuron concentration. Exposure to fine (<63 microm grain size), nutrient-rich estuarine sediments reduced effective quantum yields (Delta F/F(m')) of photosystem II in CCA species more than exposure to the same amount of fine (<63 microm grain size) calcareous sediments. Significant inhibition of photosynthesis (Delta F/F(m')) was also observed at diuron concentrations > or =2.9 microg L(-1). Fine estuarine sediments in combination with 0.79 microg L(-1) dissolved diuron, caused yields (Delta F/F(m')) to drop by 60% compared with controls after 24 h. The combined exposure to sediments and diuron also retarded recovery, thus Delta F/F(m') values were still only 60% of the controls after 9 days recovery in clean seawater. Mortality of CCA was observed in some fragments treated with combinations of sediment and diuron. Our results suggest that sediment deposition and exposure to diuron can negatively affect the photosynthetic activity of CCA, with sedimentation stress being significantly enhanced by the presence of trace concentrations of diuron.  相似文献   

Fitting growth models to length frequency data     

Laslett  Geoff M.; Eveson  J. Paige; Polacheck  Tom 《ICES Journal of Marine Science》2004,61(2):218-230

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