1,197 research outputs found
Airborne Lidar Sampling Strategies to Enhance Forest Aboveground Biomass Estimation from Landsat Imagery
Accurately estimating aboveground biomass (AGB) is important in many applications, including monitoring carbon stocks, investigating deforestation and forest degradation, and designing sustainable forest management strategies. Although lidar provides critical three-dimensional forest structure information for estimating AGB, acquiring comprehensive lidar coverage is often cost prohibitive. This research focused on developing a lidar sampling framework to support AGB estimation from Landsat images. Two sampling strategies, systematic and classification-based, were tested and compared. The proposed strategies were implemented over a temperate forest study site in northern New York State and the processes were then validated at a similar site located in central New York State. Our results demonstrated that while the inclusion of lidar data using systematic or classification-based sampling supports AGB estimation, the systematic sampling selection method was highly dependent on site conditions and had higher accuracy variability. Of the 12 systematic sampling plans, R-2 values ranged from 0.14 to 0.41 and plot root mean square error (RMSE) ranged from 84.2 to 93.9 Mg ha(-1). The classification-based sampling outperformed 75% of the systematic sampling strategies at the primary site with R-2 of 0.26 and RMSE of 70.1 Mg ha(-1). The classification-based lidar sampling strategy was relatively easy to apply and was readily transferable to a new study site. Adopting this method at the validation site, the classification-based sampling also worked effectively, with an R-2 of 0.40 and an RMSE of 108.2 Mg ha(-1) compared to the full lidar coverage model with an R-2 of 0.58 and an RMSE of 96.0 Mg ha(-1). This study evaluated different lidar sample selection methods to identify an efficient and effective approach to reduce the volume and cost of lidar acquisitions. The forest type classification-based sampling method described in this study could facilitate cost-effective lidar data collection in future studies
Spin torque resonant vortex core expulsion for an efficient radio-frequency detection scheme
Spin-polarised radio-frequency currents, whose frequency is equal to that of
the gyrotropic mode, will cause an excitation of the core of a magnetic vortex
confined in a magnetic tunnel junction. When the excitation radius of the
vortex core is greater than that of the junction radius, vortex core expulsion
is observed, leading to a large change in resistance, as the layer enters a
predominantly uniform magnetisation state. Unlike the conventional spin-torque
diode effect, this highly tunable resonant effect will generate a voltage which
does not decrease as a function of rf power, and has the potential to form the
basis of a new generation of tunable nanoscale radio-frequency detectors
Viral population estimation using pyrosequencing
The diversity of virus populations within single infected hosts presents a
major difficulty for the natural immune response as well as for vaccine design
and antiviral drug therapy. Recently developed pyrophosphate based sequencing
technologies (pyrosequencing) can be used for quantifying this diversity by
ultra-deep sequencing of virus samples. We present computational methods for
the analysis of such sequence data and apply these techniques to pyrosequencing
data obtained from HIV populations within patients harboring drug resistant
virus strains. Our main result is the estimation of the population structure of
the sample from the pyrosequencing reads. This inference is based on a
statistical approach to error correction, followed by a combinatorial algorithm
for constructing a minimal set of haplotypes that explain the data. Using this
set of explaining haplotypes, we apply a statistical model to infer the
frequencies of the haplotypes in the population via an EM algorithm. We
demonstrate that pyrosequencing reads allow for effective population
reconstruction by extensive simulations and by comparison to 165 sequences
obtained directly from clonal sequencing of four independent, diverse HIV
populations. Thus, pyrosequencing can be used for cost-effective estimation of
the structure of virus populations, promising new insights into viral
evolutionary dynamics and disease control strategies.Comment: 23 pages, 13 figure
Caring for quality of care: symbolic violence and the bureaucracies of audit.
BACKGROUND: This article considers the moral notion of care in the context of Quality of Care discourses. Whilst care has clear normative implications for the delivery of health care it is less clear how Quality of Care, something that is centrally involved in the governance of UK health care, relates to practice. DISCUSSION: This paper presents a social and ethical analysis of Quality of Care in the light of the moral notion of care and Bourdieu's conception of symbolic violence. We argue that Quality of Care bureaucracies show significant potential for symbolic violence or the domination of practice and health care professionals. This generates problematic, and unintended, consequences that can displace the goals of practice. SUMMARY: Quality of Care bureaucracies may have unintended consequences for the practice of health care. Consistent with feminist conceptions of care, Quality of Care 'audits' should be reconfigured so as to offer a more nuanced and responsive form of evaluation
mTORC1 signalling and eIF4E/4E-BP1 translation initiation factor stoichiometry influence recombinant protein productivity from GS-CHOK1 cells
Many protein-based biotherapeutics are produced in cultured Chinese hamster ovary (CHO) cell lines. Recent reports have demonstrated that translation of recombinant mRNAs and global control of the translation machinery via mammalian target of rapamycin (mTOR) signalling are important determinants of the amount and quality of recombinant protein such cells can produce. mTOR complex 1 (mTORC1) is a master regulator of cell growth/division, ribosome biogenesis and protein synthesis, but the relationship between mTORC1 signalling, cell growth and proliferation and recombinant protein yields from mammalian cells, and whether this master regulating signalling pathway can be manipulated to enhance cell biomass and recombinant protein production (rPP) are not well explored. We have investigated mTORC1 signalling and activity throughout batch culture of a panel of sister recombinant glutamine synthetase-CHO cell lines expressing different amounts of a model monoclonal IgG4, to evaluate the links between mTORC1 signalling and cell proliferation, autophagy, recombinant protein expression, global protein synthesis and mRNA translation initiation. We find that the expression of the mTORC1 substrate 4E-binding protein 1 (4E-BP1) fluctuates throughout the course of cell culture and, as expected, that the 4E-BP1 phosphorylation profiles change across the culture. Importantly, we find that the eIF4E/4E-BP1 stoichiometry positively correlates with cell productivity. Furthermore, eIF4E amounts appear to be co-regulated with 4E-BP1 amounts. This may reflect a sensing of either change at the mRNA level as opposed to the protein level or the fact that the phosphorylation status, as well as the amount of 4E-BP1 present, is important in the co-regulation of eIF4E and 4E-BP1
Webinar: Internationalization and Refugee Education
According to UNHCR, less than one percent of the more than 26.4 million refugees worldwide are resettled each year. Only 3% of refugees have access to higher education compared to the 37% global higher education access rate. This webinar aims to shed light on this global crisis and discuss innovative and collaborative solutions to respond to it.
Speakers: HaEun Kim, Program Administrator, Borderless Higher Education for Refugees - Faculty of Education, York University Michael Casasola, Senior Resettlement Officer, UNHCR Katharine Im-Jenkins, Chief Programs Officer, World University Service of Canada (WUSC) Phyllis Mureu, Executive Director, Windle International Kenya (WIK)
Moderated by: Sunand Sharma, Associate Dean, Community Citizenship and Student Leadership & Engagement – Sheridanhttps://source.sheridancollege.ca/cgei_events/1004/thumbnail.jp
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Productive resistance within the public sector: exploring organisational culture
The article examines how South Korean civil servants responded to the introduction of pay for performance. Drawing upon 31 in-depth interviews with career civil servants, it identifies what became known as 1/n, a form of ‘discreet resistance’ that emerged and evolved. The analytical framework allows productive resistance to be seen as ebbing and flowing during organisational change that sees institutionalisation, deinstitutionalisation and re-institutionalisation. In understanding the cultural context of organisational resistance the contribution is three-fold. First, a nuanced definition and understanding of productive resistance. Second, it argues that productive resistance must be seen as part of a process that does not simply reflect ‘offer and counter-offer’ within the change management process. Thirdly, it identifies differences within groups and sub-cultures concerning commitment towards resistance and how these fissures contribute towards change as new interpretive schemes and justifications are presented in light of policy reformulations
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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