641 research outputs found
The Farm Business Environment and New Generation Cooperatives as an Innovation Strategy
Agribusiness,
Understanding Super-Earths with MINERVA-Australis at USQ's Mount Kent Observatory
Super Earths, planets between 5-10 Earth masses, are the most common type of
exoplanet known, yet are completely absent from our Solar system. As a result,
their detailed properties, compositions, and formation mechanisms are poorly
understood. NASA's Transiting Exoplanet Survey Satellite (TESS) will identify
hundreds of Super-Earths orbiting bright stars, for the first time allowing
in-depth characterisation of these planets. At the University of Southern
Queensland, we are host to the MINERVA-Australis project, dedicated wholly to
the follow-up characterisation and mass measurement of TESS planets. We give an
update on the status of MINERVA-Australis and our expected performance.Comment: Accepted to appear in the peer-reviewed proceedings of the 17th
Australian Space Research Conference, held at the University of Sydney,
13th-15th November, 201
Teacher Retention Policy Coherence: An Analysis of Policies and Practices Across Federal, State, and Division Levels
As part of a larger MERC study, this report provides an overview of federal, state, and regional policies and practices relevant to teacher retention. Using key informant interviews and document analysis, the report addresses the following research questions: What teacher retention policies exist at the federal, state, and local levels? How are these policies structured at the state level and local levels? How do teacher retention policies vary across MERC divisions? Following the findings, the report presents recommendations for policy and practice
Electro-optically tunable microring resonators in lithium niobate
Optical microresonators have recently attracted a growing attention in the
photonics community. Their applications range from quantum electro-dynamics to
sensors and filtering devices for optical telecommunication systems, where they
are likely to become an essential building block. The integration of nonlinear
and electro-optical properties in the resonators represents a very stimulating
challenge, as it would incorporate new and more advanced functionality. Lithium
niobate is an excellent candidate material, being an established choice for
electro-optic and nonlinear optical applications. Here we report on the first
realization of optical microring resonators in submicrometric thin films of
lithium niobate. The high index contrast films are produced by an improved
crystal ion slicing and bonding technique using benzocyclobutene. The rings
have radius R=100 um and their transmission spectrum has been tuned using the
electro-optic effect. These results open new perspectives for the use of
lithium niobate in chip-scale integrated optical devices and nonlinear optical
microcavities.Comment: 15 pages, 8 figure
Profiling of transcriptional and epigenetic changes during directed endothelial differentiation of human embryonic stem cells identifies FOXA2 as a marker of early mesoderm commitment
Introduction: Differentiation of vascular endothelial cells (ECs) in clinically relevant numbers for injection into ischaemic areas could offer therapeutic potential in the treatment of cardiovascular conditions, including myocardial infarction, peripheral vascular disease and stroke. While we and others have demonstrated successful generation of functional endothelial-like cells from human embryonic stem cells (hESCs), little is understood regarding the complex transcriptional and epigenetic changes that occur during differentiation, in particular during early commitment to a mesodermal lineage.
Methods: We performed the first gene expression microarray study of hESCs undergoing directed differentiation to ECs using a monolayer-based, feeder-free and serum-free protocol. Microarray results were confirmed by quantitative RT-PCR and immunocytochemistry, and chromatin immunoprecipitation (ChIP)-PCR analysis was utilised to determine the bivalent status of differentially expressed genes.
Results: We identified 22 transcription factors specific to early mesoderm commitment. Among these factors, FOXA2 was observed to be the most significantly differentially expressed at the hESC–EC day 2 timepoint. ChIP-PCR analysis revealed that the FOXA2 transcription start site is bivalently marked with histone modifications for both gene activation (H3K4me3) and repression (H3K27me3) in hESCs, suggesting the transcription factor may be a key regulator of hESC differentiation.
Conclusion: This enhanced knowledge of the lineage commitment process will help improve the design of directed differentiation protocols, increasing the yield of endothelial-like cells for regenerative medicine therapies in cardiovascular disease
Implementing universal multi-qubit quantum logic gates in three and four-spin systems at room temperature
In this paper, we present the experimental realization of multi-qubit gates
in macroscopic ensemble of three-qubit and four-qubit
molecules. Instead of depending heavily on the two-bit universal gate, which
served as the basic quantum operation in quantum computing, we use pulses of
well-defined frequency and length that simultaneously apply to all qubits in a
quantum register. It appears that this method is experimentally convenient when
this procedure is extended to more qubits on some quantum computation, and it
can also be used in other physical systems.Comment: 5 Pages, 2 Figure
Drag in paired electron-hole layers
We investigate transresistance effects in electron-hole double layer systems
with an excitonic condensate. Our theory is based on the use of a minimum
dissipation premise to fix the current carried by the condensate. We find that
the drag resistance jumps discontinuously at the condensation temperature and
diverges as the temperature approaches zero.Comment: 12 pages, 1 Figure, .eps file attache
The Antarctic ozone hole during 2015 and 2016
We reviewed the 2015 and 2016 Antarctic ozone holes, making use of a variety of ground-based and spacebased measurements of ozone and ultraviolet radiation, supplemented by meteorological reanalyses. The ozone hole of 2015 was one of the most severe on record with respect to maximum area and integrated deficit and was notably longlasting, with many values above previous extremes in October, November and December. In contrast, all assessed metrics for the 2016 ozone hole were at or below their median values for the 37 ozone holes since 1979 for which adequate satellite observations exist. The 2015 ozone hole was influenced both by very cold conditions and enhanced ozone depletion caused by stratospheric aerosol resulting from the April 2015 volcanic eruption of Calbuco (Chile)
The Antarctic ozone hole during 2014
We review the 2014 Antarctic ozone hole, making use of a variety of ground-based and space-based measurements of ozone and ultra-violet radiation, supplemented by meteorological reanalyses. Although the polar vortex was relatively stable in 2014 and persisted some weeks longer into November than was the case in 2012 or 2013, the vortex temperature was close to the long-term mean in September and October with modest warming events occurring in both months, preventing severe depletion from taking place. Of the seven metrics reported here, all were close to their respective median values of the 1979–2014 record, being ranked between 16th and 21st of the 35 years for which adequate satellite observations exist
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