2,719 research outputs found
Can Domestication of Wildlife Lead to Conservation? The Economics of Tiger Farming in China
Tigers are a threatened species that might soon disappear in the wild. Not only are tigers threatened by deteriorating and declining habitat, but poachers continue to kill tigers for traditional medicine, decoration pieces and so on. Although international trade in tiger products has been banned since 1987 and domestic trade within China since 1993, tigers continue to be poached and Chinese entrepreneurs have established tiger farms in anticipation of their demise. While China desires to permit sale of tiger products from captive-bred tigers, this is opposed on the grounds that it likely encourages illegal killing. Instead, wildlife conservationists lobby for more spending on anti-poaching and trade-ban enforcement. In this study, a mathematical bioeconomic model is used to investigate the issue. Simulation results indicate that, unless range states are characterized by institutions (rule of law, low corruption) similar to those found in the richest countries, reliance on enforcement alone is insufficient to guarantee survival of wild tigers. Likewise, even though conservation payments could protect wild tigers, the inability to enforce contracts militates against this. Our model indicates that wild tigers can be protected by permitting sale of products from tiger farms, although this likely requires the granting of an exclusive license to sellers. Finally, it is possible to tradeoff enforcement effort and sale of products from captive-bred animals, but such tradeoffs are worsened by deteriorating tiger habitat.endangered species, extinction, wildlife farming and bioeconomics
CAN DOMESTICATION OF WILDLIFE LEAD TO CONSERVATION? THE ECONOMICS OF TIGER FARMING IN CHINA
Tigers are a threatened species that might soon disappear in the wild. Not only are tigers threatened by deteriorating and declining habitat, but poachers continue to kill tigers for traditional medicine, decoration pieces and so on. Although international trade in tiger products has been banned since 1987 and domestic trade within China since 1993, tigers continue to be poached and Chinese entrepreneurs have established tiger farms in anticipation of their demise. While China desires to permit sale of tiger products from captive-bred tigers, this is opposed on the grounds that it likely encourages illegal killing. Instead, wildlife conservationists lobby for more spending on anti-poaching and trade-ban enforcement. In this study, a mathematical bioeconomic model is used to investigate the issue. Simulation results indicate that, unless range states are characterized by institutions (rule of law, low corruption) similar to those found in the richest countries, reliance on enforcement alone is insufficient to guarantee survival of wild tigers. Likewise, even though conservation payments could protect wild tigers, the inability to enforce contracts militates against this. Our model indicates that wild tigers can be protected by permitting sale of products from tiger farms, although this likely requires the granting of an exclusive license to sellers. Finally, it is possible to tradeoff enforcement effort and sale of products from captive-bred animals, but such tradeoffs are worsened by deteriorating tiger habitat.endangered species and extinction, wildlife farming, economics of natural, mathematical bioeconomics, Environmental Economics and Policy, Q27, C61, Q57,
Target enrichment of ultraconserved elements from arthropods provides a genomic perspective on relationships among Hymenoptera
Gaining a genomic perspective on phylogeny requires the collection of data
from many putatively independent loci collected across the genome. Among
insects, an increasingly common approach to collecting this class of data
involves transcriptome sequencing, because few insects have high-quality genome
sequences available; assembling new genomes remains a limiting factor; the
transcribed portion of the genome is a reasonable, reduced subset of the genome
to target; and the data collected from transcribed portions of the genome are
similar in composition to the types of data with which biologists have
traditionally worked (e.g., exons). However, molecular techniques requiring RNA
as a template are limited to using very high quality source materials, which
are often unavailable from a large proportion of biologically important insect
samples. Recent research suggests that DNA-based target enrichment of conserved
genomic elements offers another path to collecting phylogenomic data across
insect taxa, provided that conserved elements are present in and can be
collected from insect genomes. Here, we identify a large set (n1510) of
ultraconserved elements (UCE) shared among the insect order Hymenoptera. We use
in silico analyses to show that these loci accurately reconstruct relationships
among genome-enabled Hymenoptera, and we design a set of baits for enriching
these loci that researchers can use with DNA templates extracted from a variety
of sources. We use our UCE bait set to enrich an average of 721 UCE loci from
30 hymenopteran taxa, and we use these UCE loci to reconstruct phylogenetic
relationships spanning very old (220 MYA) to very young (1 MYA)
divergences among hymenopteran lineages. In contrast to a recent study
addressing hymenopteran phylogeny using transcriptome data, we found ants to be
sister to all remaining aculeate lineages with complete support
An Economic Analysis of Mountain Pine Beetle Impacts in a Global Context
The economic effects of the mountain pine beetle outbreak in British Columbia are simulated using a multi-region spatial price equilibrium model coupled with a stochastic dynamic updating procedure. The simulation captures expected changes in the B.C. timber supply, growth of plantation forests in the southern hemisphere and an escalating Russian log export tax. The results indicate lumber and log prices will rise in B.C., offsetting some of the economic loss to timber producers. However, on net producers in the B.C. forest industry will experience a decrease in economic surplus.Mountain pine beetle; spatial price equilibirum; trade modeling
Levels in 99Zr observed in the decay of 99Y
New investigation of the decay scheme of 99Y to 99Zr removes minor discrepancies between decay and prompt-fission data.The existence of a strongly coupled band on the 725-keV level postulated in an earlier beta-decay work is not confirmed. Calculations in the IBFM framework allow an alternative interpretation of the even-parity levels above 500 keV
Fluorine Chemistry at Extreme Conditions: Possible Synthesis of Hgf4
By irradiating a pressurized mixture of a fluorine-bearing compound (XeF2XeF2) and HgF2HgF2 with synchrotron hard x-rays ... (See full text for complete abstract
Structure of the doublet bands in doubly odd nuclei: The case of
The structure of the doublet bands in is
investigated within the framework of the Interacting Vector Boson Fermion Model
(IVBFM). A new, purely collective interpretation of these bands is given on the
basis of the used boson-fermion dynamical symmetry of the model. The energy
levels of the doublet bands as well as the absolute and
transition probabilities between the states of both yrast and yrare bands are
described quite well. The observed odd-even staggering of both and
values is reproduced by the introduction of an appropriate interaction
term of quadrupole type, which produces such a staggering effect in the
transition strengths. The calculations show that the appearance of doublet
bands in certain odd-odd nuclei could be a consequence of the realization of a
larger dynamical symmetry based on the non-compact supersymmetry group
.Comment: 12 pages, 8 figure
Occupational Status and Health Transitions
We use longitudinal data from the 1984 through 2007 waves of the Panel Study of Income Dynamics to examine how occupational status is related to the health transitions of 30 to 59 year-old U.S. males. A recent history of blue-collar employment predicts a substantial increase in the probability of transitioning from very good into bad self-assessed health, relative to white-collar employment, but with no evidence of occupational differences in movements from bad to very good health. These findings are robust to a series of sensitivity analyses. The results suggest that blue-collar workers "wear out" faster with age because they are more likely, than their white-collar counterparts, to experience negative health shocks. This partly reflects differences in the physical demands of blue-collar and white-collar jobs.occupations, physical demands, health
The Luminosity Dependence of Quasar Clustering
We investigate the luminosity dependence of quasar clustering, inspired by
numerical simulations of galaxy mergers that incorporate black hole growth.
These simulations have motivated a new interpretation of the quasar luminosity
function. In this picture, the bright end of the quasar luminosity function
consists of quasars radiating nearly at their peak luminosities, while the
faint end consists mainly of very similar sources, but at dimmer phases in
their evolution. We combine this model with the statistics of dark matter halos
that host quasar activity. We find that, since bright and faint quasars are
mostly similar sources seen in different evolutionary stages, a broad range in
quasar luminosities corresponds to only a narrow range in the masses of quasar
host halos. On average, bright and faint quasars reside in similar host halos.
Consequently, we argue that quasar clustering should depend only weakly on
luminosity. This prediction is in qualitative agreement with recent
measurements of the luminosity dependence of the quasar correlation function
(Croom et al. 2005) and the galaxy-quasar cross-correlation function
(Adelberger & Steidel 2005). Future precision clustering measurements from SDSS
and 2dF, spanning a large range in luminosity, should provide a strong test of
our model.Comment: 9 pages, 4 figures, submitted to Ap
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