5,094 research outputs found
Philadelphia region input-output study working papers. Volume 3 - Final demand
Input-output coefficients for 86 final demand sectors in Philadelphia regio
Examination of actin and microtubule dependent APC localisations in living mammalian cells
Abstract (provisional)
Background
The trafficking of the adenomatous polyposis coli (APC) tumour suppressor protein in mammalian cells is a perennially controversial topic. Immunostaining evidence for an actin-associated APC localisation at intercellular junctions has been previously presented, though live imaging of mammalian junctional APC has not been documented.
Results
Using live imaging of transfected COS-7 cells we observed intercellular junction-associated pools of GFP-APC in addition to previously documented microtubule-associated GFP-APC and a variety of minor localisations. Although both microtubule and junction-associated populations could co-exist within individual cells, they differed in their subcellular location, dynamic behaviour and sensitivity to cytoskeletal poisons. GFP-APC deletion mutant analysis indicated that a protein truncated immediately after the APC armadillo repeat domain retained the ability to localise to adhesive membranes in transfected cells. Supporting this, we also observed junctional APC immunostaining in cultures of human colorectal cancer cell line that express truncated forms of APC.
Conclusions
Our data indicate that APC can be found in two spatially separate populations at the cell periphery and these populations can co-exist in the same cell. The first localisation is highly dynamic and associated with microtubules near free edges and in cell vertices, while the second is comparatively static and is closely associated with actin at sites of cell-cell contact. Our imaging confirms that human GFP-APC possesses many of the localisations and behaviours previously seen by live imaging of Xenopus GFP-APC. However, we report the novel finding that GFP-APC puncta can remain associated with the ends of shrinking microtubules. Deletion analysis indicated that the N-terminal region of the APC protein mediated its junctional localisation, consistent with our observation that truncated APC proteins in colon cancer cell lines are still capable of localising to the cell cortex. This may have implications for the development of colorectal cancer
Generation of Hyperentangled Photons Pairs
We experimentally demonstrate the first quantum system entangled in every
degree of freedom (hyperentangled). Using pairs of photons produced in
spontaneous parametric downconversion, we verify entanglement by observing a
Bell-type inequality violation in each degree of freedom: polarization, spatial
mode and time-energy. We also produce and characterize maximally hyperentangled
states and novel states simultaneously exhibiting both quantum and classical
correlations. Finally, we report the tomography of a 2x2x3x3 system
(36-dimensional Hilbert space), which we believe is the first reported photonic
entangled system of this size to be so characterized.Comment: 5 pages, 3 figures, 1 table, published versio
Modelling trade offs between public and private conservation policies
To reduce global biodiversity loss, there is an urgent need to determine the
most efficient allocation of conservation resources. Recently, there has been a
growing trend for many governments to supplement public ownership and
management of reserves with incentive programs for conservation on private
land. At the same time, policies to promote conservation on private land are
rarely evaluated in terms of their ecological consequences. This raises
important questions, such as the extent to which private land conservation can
improve conservation outcomes, and how it should be mixed with more traditional
public land conservation. We address these questions, using a general framework
for modelling environmental policies and a case study examining the
conservation of endangered native grasslands to the west of Melbourne,
Australia. Specifically, we examine three policies that involve: i) spending
all resources on creating public conservation areas; ii) spending all resources
on an ongoing incentive program where private landholders are paid to manage
vegetation on their property with 5-year contracts; and iii) splitting
resources between these two approaches. The performance of each strategy is
quantified with a vegetation condition change model that predicts future
changes in grassland quality. Of the policies tested, no one policy was always
best and policy performance depended on the objectives of those enacting the
policy. This work demonstrates a general method for evaluating environmental
policies and highlights the utility of a model which combines ecological and
socioeconomic processes.Comment: 20 pages, 5 figure
The impact of superphosphate and surface-applied lime on the profitability and sustainability of wool production on the tablelands of NSW
Soil acidification is one of the major forms of soil degradation in higher rainfall areas of the tablelands of NSW. A grazing experiment was conducted near Sutton, NSW, to assess the effect of various rates of superphosphate, lime, sewage ash and stocking rates on wool production and sustainability between 1999 and 2008. The results from the discounted cash flow analysis show that the net present value of the treatment without lime, the lower rate of superphosphate and the lowest stocking rate returned the highest net present value of 278.70/ha and 234.60/ha. The net present value fell by $205.24/ha when the level of superphosphate rate increased to 250kg/ha every year. The net present value decreased as the level of stocking rate increased. We conclude that wool producers will be unlikely to use lime to ameliorate acid soil, even though production will not be sustainable, unless there are more favourable input and commodity prices in the market and government intervention.economic, acid soil, lime, superphosphate, sewage ash, stocking rate, policy,
4D Printing of origami structures for minimally invasive surgeries using functional scaffold
Origami structures have attracted attention in biomedical applications due to their ability to develop surgical tools that can be expanded from a minimal volume to a larger and functional device. On the other hand, four-dimensional (4D) printing is an emerging technology, which involves 3D printing of smart materials that can respond to external stimuli such as heat. This short communication introduces the proof of concept of merging origami and 4D printing technologies to develop minimally invasive delivery of functional biomedical scaffolds with high shape recovery. The shape-memory effect (SME) of the PLA filament and the origami designs were also assessed in terms of deformability and recovery rate. The results showed that herringbone tessellation origami structure combined with internal natural cancellous bone core satisfies the design requirement of foldable scaffolds. The substantial and consistent SME of the 4D printed herringbone tessellation origami, which exhibited 96% recovery compared to 61% for PLA filament, was the most significant discovery of this paper. The experiments demonstrated how the use of 4D printing in situ with origami structures could achieve reliable and repeatable results, therefore conclusively proving how 4D printing of origami structures can be applied to biomedical scaffolds
Manipulating biphotonic qutrits
Quantum information carriers with higher dimension than the canonical qubit
offer significant advantages. However, manipulating such systems is extremely
difficult. We show how measurement induced non-linearities can be employed to
dramatically extend the range of possible transforms on biphotonic qutrits; the
three level quantum systems formed by the polarisation of two photons in the
same spatio-temporal mode. We fully characterise the biphoton-photon
entanglement that underpins our technique, thereby realising the first instance
of qubit-qutrit entanglement. We discuss an extension of our technique to
generate qutrit-qutrit entanglement and to manipulate any bosonic encoding of
quantum information.Comment: 4 pages, 4 figure
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