2,027 research outputs found
Private ‘Rescue’-by-Purchase of Stolen Cultural Goods: The Material and Social Consequences and the Complicity of Europe and North America
‘Rescue’ has long provided a justification for the handling of illicit cultural goods, yet the specific consequences of this practice have not been systematically documented. This paper draws on historic, recent and still-emerging cases around the world to assess the resurgent argument that looted antiquities and stolen artefacts should be rescued through purchases made by private collectors. It shows that the practice is promoted by politically exposed persons, who use it for money laundering and reputation laundering; that proceeds from the practice may be received by transnational organised crime groups; and that its social and political acceptability is exploited to facilitate fraud and embezzlement.
While many of these cases demonstrate complicity on the part of elites and authorities within the societies that are victimised, they are emblematic of the global structure of this enterprise. They also reaffirm the complicity of markets and authorities in the Global North/West in illicit flows of cultural assets that are exceptionally harmful to societies in the Global South/East
An Analysis of the Spatial Genetic Structure of a Hybrid Zone Between Two Species of Killifish, Fundulus Heteroclitus and F. Grandis
Hybridization offers unique insight into the evolutionary process of speciation and the forces that maintain barriers to reproduction. In northeast Florida, a hybrid zone between two species of killifish, Fundulus heteroclitus and F. grandis, has been identified near Flagler Beach, FL, although the exact boundaries of the hybrid zone remain unknown (Gonzalez et al. 2009). This study aims to determine the fine-scale spatial genetic patterns of the hybrid zone and test the hypothesis that species ranges are influenced by changes in dominant vegetation. Results from an ADMIXTURE analysis and FST data indicated the boundary of the area of overlap between the two parental species to exist at Marineland, FL in the north and Tomoka Basin, FL in the south, while the boundaries of hybridization (i.e. the hybrid zone) existed in a smaller region between Bings Landing, FL and Tomoka Basin, FL. The area of overlap showed a highly mosaic pattern of allele frequencies, suggesting the spatial genetic structure of the hybrid zone is influenced by exogenous selection. Reproductive barriers were found to be the strongest in sites where F. heteroclitus was the more abundant species, but weaker in areas with predominantly F. grandis. No single environmental factor correlated significantly with the genetic distribution throughout the zone of overlap, and it is likely a combination of multiple factors that influence genetic variation, suggesting that habitat differences were likely important in the diversification of these two species
THE DETERMINATION OF TRACE METALS BY CAPILLARY ELECTROPHORESIS
The development of a capillary electrophoresis (CE) method for the determination of
inorganic and organo mercury species as their dithizone sulphonate (DzS) complexes
using coated capillary columns is described. The complexes were pre-formed before
injection and detection was by direct measurement of the visible absorbance of the
complexes. Dithizone sulphonate was used in place of cysteine to separate methyl
mercury in the final stage of a simplified Westoo extraction procedure. The method
was than applied to the analysis of methyl mercury in a crab and several fish meat
samples. Good quantitative performance is demonstrated by spiking experiments and
analysis of DORM-1 certified reference material. The method was found to be very
sensitive and a detection limit of 2 µg Kgˉ¹ could be achieved for a l0g sample of fish
flesh.
A CE method for the determination of uranium (VI) as the arsenazo III complex was
developed and the effect of interfering metal ions was studied. The calibration was
found to be linear from 10 µg 1ˉ¹ -10 mg 1ˉ¹ using gravity injections and a detection
limit of less than 1 µg 1ˉ¹ was achieved with electrokinetic injection.
A study was made of injection techniques and their applicability to the enhancement
of sensitivity in synthetic standards and environmental samples.
The effect of capillary surface chemistry on the peak shape of the migrating uranyl-arsenazo
III was also studied using fused silica capillaries with two different internal
coatings and three polymeric capillaries.
A study was also carried out on the construction and investigation of a post-capillary
reactor for the determination of trace metals by UV-Vis absorption after formation of
intensely absorbing coloured complexes. The main principle of operation was based
on the infusion of the colorimetric reagent into a small 50µm gap between the
separation capillary and the reaction capillary. The gap was enclosed by a permeable
membrane and the flow of reagent was achieved by the application of a slight pressure
to the post-capillary reactor cell. Two reagents were studied, namely, xylenol orange
(XO) and 4 (2-pyridylazo) resorcinol (PAR), for the separation and detection of
copper (U), cadmium (II), cobalt (II), nickel (II), zinc (II), and manganese (II). Lead
(II) was also included in the XO system.Dionex, U
Quantitative analysis of open-source data on metal detecting for cultural property: Estimation of the scale and intensity of metal detecting and the quantity of metal-detected cultural goods
Through netnographic analysis of online forums and social networks, this study presents quantitative analysis of the scale and intensity of metal detecting and the quantity of metal-detected cultural goods. It adapts open-source data to develop empirical measures; to ensure reliability and consistency of sourcing and interpretation, these data were drawn from English-language forums and networks. Based on a poll of 668 online community members, it infers the size of active detecting communities from the size (93.42%) of online detecting communities. Based on open-source data on the detecting practices of 101 detectorists, the worst tolerable weather for 151 detectorists and seasonal variations in the reporting of 1,089,337 finds to the Portable Antiquities Scheme over 13 years, it determines a pragmatic minimum average of 286.02 h of detecting per person per year. Comparing activity in a wide range of permissive, restrictive and prohibitive regulatory environments - based on local-language forums and networks in Australia, Austria, Flanders and elsewhere in Belgium, Canada, Denmark, England and Wales, Ireland, the Netherlands, New Zealand, Northern Ireland, Scotland, and the United States - it finds that permissive regulation is ineffective in minimising harm to heritage assets, whether in the form of licit misbehaviour or criminal damage. Restrictive and prohibitive regulation appear to be more effective, insofar as there is less overall loss of archaeological evidence
Contemporary remotely sensed data products refine invasive plants risk mapping in data poor regions
Invasive weeds are a serious problem worldwide, threatening biodiversity and damaging economies. Modeling potential distributions of invasive weeds can prioritize locations for monitoring and control efforts, increasing management efficiency. Forecasts of invasion risk at regional to continental scales are enabled by readily available downscaled climate surfaces together with an increasing number of digitized and georeferenced species occurrence records and species distribution modeling techniques. However, predictions at a finer scale and in landscapes with less topographic variation may require predictors that capture biotic processes and local abiotic conditions. Contemporary remote sensing (RS) data can enhance predictions by providing a range of spatial environmental data products at fine scale beyond climatic variables only. In this study, we used the Global Biodiversity Information Facility (GBIF) and empirical maximum entropy (MaxEnt) models to model the potential distributions of 14 invasive plant species across Southeast Asia (SEA), selected from regional and Vietnam’s lists of priority weeds. Spatial environmental variables used to map invasion risk included bioclimatic layers and recent representations of global land cover, vegetation productivity (GPP), and soil properties developed from Earth observation data. Results showed that combining climate and RS data reduced predicted areas of suitable habitat compared with models using climate or RS data only, with no loss in model accuracy. However, contributions of RS variables were relatively limited, in part due to uncertainties in the land cover data. We strongly encourage greater adoption of quantitative remotely sensed estimates of ecosystem structure and function for habitat suitability modeling. Through comprehensive maps of overall predicted area and diversity of invasive species, we found that among lifeforms (herb, shrub, and vine), shrub species have higher potential invasion risk in SEA. Native invasive species, which are often overlooked in weed risk assessment, may be as serious a problem as non-native invasive species. Awareness of invasive weeds and their environmental impacts is still nascent in SEA and information is scarce. Freely available global spatial datasets, not least those provided by Earth observation programs, and the results of studies such as this one provide critical information that enables strategic management of environmental threats such as invasive species
Nematic phases and elastoresistivity from a multiorbital strange metal
We propose and study a two-orbital lattice extension of the Sachdev-Ye-Kitaev
model in the large- limit. The phase diagram of this model features a high
temperature isotropic strange metal which undergoes a first-order thermal
transition into a nematic insulator or a continuous thermal transition into
nematic metal phase, separated by a tunable tricritical point. These phases
arise from spontaneous partial orbital polarization of the multiorbital
non-Fermi liquid. We explore the spectral and transport properties of this
model, including the d.c. elastoresistivity, which exhibits a peak near the
nematic transition, as well as the nonzero frequency elastoconductivity. Our
work offers a useful perspective on nematic phases and transport in correlated
multiorbital systems.Comment: 7 pages, 4 figure
Magnetohydrodynamical torsional oscillations from thermo-resistive instability in hot jupiters
Hot jupiter atmospheres may be subject to a thermo-resistive instability
where an increase in the electrical conductivity due to ohmic heating results
in runaway of the atmospheric temperature. We introduce a simplified
one-dimensional model of the equatorial sub-stellar region of a hot jupiter
which includes the temperature-dependence and time-dependence of the electrical
conductivity, as well as the dynamical back-reaction of the magnetic field on
the flow. This model extends our previous one-zone model to include the radial
structure of the atmosphere. Spatial gradients of electrical conductivity
strongly modify the radial profile of Alfv\'en oscillations, leading to
steepening and downwards transport of magnetic field, enhancing dissipation at
depth. We find unstable solutions that lead to self-sustained oscillations for
equilibrium temperatures in the range --~K,
and magnetic field in the range --~G. For a given set of
parameters, self-sustained oscillations occur in a narrow range of equilibrium
temperatures which allow the magnetic Reynolds number to alternate between
large and small values during an oscillation cycle. Outside of this temperature
window, the system reaches a steady state in which the effect of the magnetic
field can be approximated as a magnetic drag term. Our results show that
thermo-resistive instability is a possible source of variability in magnetized
hot jupiters at colder temperatures, and emphasize the importance of including
the temperature-dependence of electrical conductivity in models of atmospheric
dynamics.Comment: Submitted to The Astrophysical Journa
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