378 research outputs found
Working as one: a road map to disaster resilience for Australia
This report offers a roadmap for enhancing Australia’s disaster resilience, building on the 2011 National Strategy for Disaster Resilience. It includes a snapshot of relevant issues and current resilience efforts in Australia, outlining key challenges and opportunities.
Overview
Natural disasters cause widespread disruption, costing the Australian economy 23 billion by 2050.
With more frequent natural disasters with greater consequences, Australian communities need the ability to prepare and plan for them, absorb and recover from them, and adapt more successfully to their effects.
Enhancing Australian resilience will allow us to better anticipate disasters and assist in planning to reduce losses, rather than just waiting for the next king hit and paying for it afterwards.
This report offers a roadmap for enhancing Australia’s disaster resilience, building on the 2011 National Strategy for Disaster Resilience. It includes a snapshot of relevant issues and current resilience efforts in Australia, outlining key challenges and opportunities.
The report sets out 11 recommendations to help guide Australia towards increasing national resilience, from individuals and local communities through to state and federal agencies
Integrating cavity based gas cells: a multibeam compensation scheme for pathlength variation
We present a four beam ratiometric setup for an integrating sphere based gas cell, which can correct for changes in pathlength due to sphere wall contamination. This allows for the gas absorption coefficient to be determined continuously without needing to recalibrate the setup. We demonstrate the technique experimentally, measuring methane gas at 1651nm. For example, contamination covering 1.2% of the sphere wall resulted in an uncompensated error in gas absorption coefficient of ≈41%. With the ratiometric scheme, this error was reduced to ≈2%. Potential limitations of the technique, due to subsequent deviations from mathematical assumptions are discussed, including severe sphere window contamination
Wildlife Trade in Morocco: Use, Conservation, Laws and Welfare
Official records on the numbers of animals being removed from the wild for commercial purposes are
often patchy, incomplete or absent entirely. Available data from the legal trade combined with surveys of
legal and illegal trade can give an insight into the species that are being targeted, the numbers in which
they are being removed from the wild, the reasons for which they are traded and can highlight
conservation, legal and welfare issues relating to this trade. Morocco, situated on the north-west coast of
the African continent as little as eight miles from the Spanish mainland, is a hub for tourism in the region
and a focal point for trade between Africa and Europe. Although some work had been conducted on
specific areas and species in Morocco, a comprehensive account of the wildlife trade was lacking, and
little was known about the effects of wildlife trade in the country. Morocco updated its wildlife trade laws
in 2015 and for the first time has the ability to effectively combat illegal and unsustainable trade, provided
sufficient resources are allocated to the law’s implementation. This law is comprehensive and clear and
Morocco therefore provides an interesting case study to explore the effectiveness of wildlife trade laws.
My publications included in this PhD by Published Work document the results of market and online
surveys carried out between April 2013 and April 2018 over the course of six study-periods. I investigated
the use, conservation, laws and welfare relating to the sale and keeping of birds, mammals and reptiles
in markets in 27 Moroccan cities and two Spanish cities within Morocco’s borders. My research has
provided detailed, robust data on the trade of over 11,000 animals of 47 species, sold as pets, decoration,
photo props, clothing, and medicine. This trade represents a significant conservation concern for many
of these species and the majority of animals are being kept in consistently poor welfare conditions. The
majority of wild animal trade in Morocco is illegal according to new law. Through my research and
publications, I have documented a baseline for Moroccan wildlife trade and provided NGOs and the
Moroccan government with much-needed data to inform policy and conservation initiatives. These data
have been given to conservation organisations operating in Morocco and to the Moroccan government,
in both paper and summary form and disseminated to the wider conservation community. They provide
these stakeholders with a detailed account of hotspots, species vulnerable to overexploitation and causes
of the wildlife trade, with the aim of helping conservation efforts to become more targeted and therefore
more effective in situations with limited resources
Chemical differentiation in regions of high-mass star formation I. CS, dust and N2H^+ in southern sources
Aims. Our goals are to compare the CS, N2H+ and dust distributions in a
representative sample of high-mass star forming dense cores and to determine
the physical and chemical properties of these cores. Methods. We compare the
results of CS(5-4) and 1.2 mm continuum mapping of twelve dense cores from the
southern hemisphere presented in this work, in combination with our previous
N2H+(1-0) and CS(2-1) data. We use numerical modeling of molecular excitation
to estimate physical parameters of the cores. Results. Most of the maps have
several emission peaks (clumps). We derive basic physical parameters of the
clumps and estimate CS and N2H+ abundances. Masses calculated from LVG
densities are higher than CS virial masses and masses derived from continuum
data, implying small-scale clumpiness of the cores. For most of the objects,
the CS and continuum peaks are close to the IRAS point source positions. The
CS(5-4) intensities correlate with continuum fluxes per beam in all cases, but
only in five cases with the N2H+(1-0) intensities. The study of spatial
variations of molecular integrated intensity ratios to continuum fluxes reveals
that I(N2H+)/F{1.2} ratios drop towards the CS peaks for most of the sources,
which can be due to a N2H+ abundance decrease. For CS(5-4), the I(CS)/F{1.2}
ratios show no clear trends with distance from the CS peaks, while for CS(2-1)
such ratios drop towards these peaks. Possible explanations of these results
are considered. The analysis of normalized velocity differences between CS and
N2H+ lines has not revealed indications of systematic motions towards CS peaks.Comment: 13 pages, 5 figures, accepted by Astronomy and Astrophysic
A recent accretion burst in the low-mass protostar IRAS 15398-3359: ALMA imaging of its related chemistry
Low-mass protostars have been suggested to show highly variable accretion
rates through-out their evolution. Such changes in accretion, and related
heating of their ambient envelopes, may trigger significant chemical variations
on different spatial scales and from source-to-source. We present images of
emission from C17O, H13CO+, CH3OH, C34S and C2H toward the low-mass protostar
IRAS 15398-3359 on 0.5" (75 AU diameter) scales with the Atacama Large
Millimeter/submillimeter Array (ALMA) at 340 GHz. The resolved images show that
the emission from H13CO+ is only present in a ring-like structure with a radius
of about 1-1.5" (150-200 AU) whereas the CO and other high dipole moment
molecules are centrally condensed toward the location of the central protostar.
We propose that HCO+ is destroyed by water vapor present on small scales. The
origin of this water vapor is likely an accretion burst during the last
100-1000 years increasing the luminosity of IRAS 15398-3359 by a factor of 100
above its current luminosity. Such a burst in luminosity can also explain the
centrally condensed CH3OH and extended warm carbon-chain chemistry observed in
this source and furthermore be reflected in the relative faintness of its
compact continuum emission compared to other protostars.Comment: Accepted for publication in ApJ Letters; 14 pages, 5 figure
Surface Layer Accretion in Conventional and Transitional Disks Driven by Far-Ultraviolet Ionization
Whether protoplanetary disks accrete at observationally significant rates by
the magnetorotational instability (MRI) depends on how well ionized they are.
Disk surface layers ionized by stellar X-rays are susceptible to charge
neutralization by small condensates, ranging from ~0.01-micron-sized grains to
angstrom-sized polycyclic aromatic hydrocarbons (PAHs). Ion densities in
X-ray-irradiated surfaces are so low that ambipolar diffusion weakens the MRI.
Here we show that ionization by stellar far-ultraviolet (FUV) radiation enables
full-blown MRI turbulence in disk surface layers. Far-UV ionization of atomic
carbon and sulfur produces a plasma so dense that it is immune to ion
recombination on grains and PAHs. The FUV-ionized layer, of thickness 0.01--0.1
g/cm^2, behaves in the ideal magnetohydrodynamic limit and can accrete at
observationally significant rates at radii > 1--10 AU. Surface layer accretion
driven by FUV ionization can reproduce the trend of increasing accretion rate
with increasing hole size seen in transitional disks. At radii < 1--10 AU,
FUV-ionized surface layers cannot sustain the accretion rates generated at
larger distance, and unless turbulent mixing of plasma can thicken the
MRI-active layer, an additional means of transport is needed. In the case of
transitional disks, it could be provided by planets.Comment: Final proofed version. Corrects X-ray-driven accretion rates in the
high PAH case for Figures 8 and
Prevalence and geographical distribution of Papio hamadryas papillomavirus 1 (PhPV1) in Kenyan baboons
Papio hamadryas papillomavirus (PhPV) 1, 2, and 3, are Alphapapillomaviruses that have been detected in Kenyan Olive baboons but the distribution is unknown. Therefore, cervical screening for PhPV1 was performed in baboons from various areas in Kenya using a nested polymerase chain reaction. The prevalence rate was 33%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135993/1/jmp12247.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135993/2/jmp12247_am.pd
Ratiometric pathlength calibration of integrating sphere-based absorption cells
Chemical sensors based on optical absorption require accurate knowledge of the optical pathlength of the sample cell. Integrating spheres offer increased pathlengths compared to single pass cells combined with tolerance to misalignment, making them attractive for use in challenging environments subject to vibration. However, the equivalent optical pathlength can be degraded by dirt and / or condensation on the inner surface of the sphere. We present a new scheme for in-situ calibration that uses a ratiometric two-beam approach. Results are presented for an integrating sphere used in the measurement of methane by tunable diode laser spectroscopy (TDLS) at 1651nm. Reduced sphere reflectivity was simulated by applying small areas of black tape on the inner surface. At methane concentrations of 1500ppm and 3125 ppm, for areas of contamination up to 2.3% of the sphere wall, the technique reduced the error from over 50% to within ±4%. At a concentration of 6250 ppm and the most severe fouling corresponding to 2.9% wall coverage, the technique reduced the error from 55-65% to within ±11
The young embedded disk L1527 IRS: constraints on the water snowline and cosmic ray ionization rate from HCO+ observations
The water snowline in circumstellar disks is a crucial component in planet
formation, but direct observational constraints on its location remain sparse
due to the difficulty of observing water in both young embedded and mature
protoplanetary disks. Chemical imaging provides an alternative route to locate
the snowline, and HCO isotopologues have been shown to be good tracers in
protostellar envelopes and Herbig disks. Here we present
0.5 resolution (35 au radius) Atacama Large
Millimeter/submillimeter Array (ALMA) observations of HCO and
HCO toward the young (Class 0/I) disk L1527 IRS. Using a
source-specific physical model with the midplane snowline at 3.4 au and a small
chemical network, we are able to reproduce the HCO and HCO
emission, but for HCO only when the cosmic ray ionization rate is lowered
to s. Even though the observations are not sensitive to the
expected HCO abundance drop across the snowline, the reduction in HCO
above the snow surface and the global temperature structure allow us to
constrain a snowline location between 1.8 and 4.1 au. Deep observations are
required to eliminate the envelope contribution to the emission and to derive
more stringent constraints on the snowline location. Locating the snowline in
young disks directly with observations of HO isotopologues may therefore
still be an alternative option. With a direct snowline measurement, HCO
will be able to provide constraints on the ionization rate.Comment: Accepted for publication in ApJ, 15 pages, 6 figures and appendi
Dynamics and Depletion in Thermally Supercritical Starless Cores
In previous studies we identified two classes of starless cores, thermally
subcritical and supercritical, distinguished by different dynamical behavior
and internal structure. Here we study the evolution of the
dynamically-unstable, thermally-supercritical cores by means of a numerical
hydrodynamic simulation that includes radiative equilibrium and simple
molecular chemistry. We use our non-LTE radiative transfer code MOLLIE to
predict observable CO and N2H+ line spectra, including the non-LTE hyperfine
ratios of N2H+, during the contraction. These are compared against observations
of the starless core L1544.Comment: accepted for publication in MNRA
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