771 research outputs found
Plasmodium yoelii infection of BALB/c mice results in expansion rather than induction of CD4+ Foxp3+ regulatory T cells
Recently, we demonstrated elevated numbers of CD4(+) Foxp3(+) regulatory T (Treg) cells in Plasmodium yoelii‐infected mice contributing to the regulation of anti‐malarial immune response. However, it remains unclear whether this increase in Treg cells is due to thymus‐derived Treg cell expansion or induction of Treg cells in the periphery. Here, we show that the frequency of Foxp3(+) Treg cells expressing neuropilin‐1 (Nrp‐1) decreased at early time‐points during P. yoelii infection, whereas percentages of Helios(+) Foxp3(+) Treg cells remained unchanged. Both Foxp3(+) Nrp‐1(+) and Foxp3(+) Nrp‐1(−) Treg cells from P. yoelii‐infected mice exhibited a similar T‐cell receptor Vβ chain usage and methylation pattern in the Treg‐specific demethylation region within the foxp3 locus. Strikingly, we did not observe induction of Foxp3 expression in Foxp3(−) T cells adoptively transferred to P. yoelii‐infected mice. Hence, our results suggest that P. yoelii infection triggered expansion of naturally occurring Treg cells rather than de novo induction of Foxp3(+) Treg cells
Developing a model of upland swamp structure, function and evolution for biodiversity conservation and rehabilitation: The case of threatened Temperate Highland Peat Swamps on Sandstone (THPSS)
Temperate highland peat swamps on sandstone (THPSS) (called upland swamps) are a form of topogenous mire which occur on the plateau areas of eastern Australia. These systems are well recognised for their ecological value, under several State and Federal policies. However, our understanding of their structure, function and evolution remains limited. This study examines the sedimentology, age structure, hydrological function and stygofauna diversity of 19 valley-bottom swamps in the Blue Mountains and Southern Highlands of NSW to produce a regional model of THPSS geo-ecological function. This regional model provides a template for environmental health assessment and rehabilitation of these systems, and to inform State and Federal policy making on the conservation status of these systems. © 2014 University of Melbourn
Improving Models for Student Retention and Graduation using Markov Chains
Graduation rates are a key measure of the long-term efficacy of academic
interventions. However, challenges to using traditional estimates of graduation
rates for underrepresented students include inherently small sample sizes and
high data requirements. Here, we show that a Markov model increases confidence
and reduces biases in estimated graduation rates for underrepresented minority
and first-generation students. We use a Learning Assistant program to
demonstrate the Markov model's strength for assessing program efficacy. We find
that Learning Assistants in gateway science courses are associated with a 9%
increase in the six-year graduation rate. These gains are larger for
underrepresented minority (21%) and first-generation students (18%). Our
results indicate that Learning Assistants can improve overall graduation rates
and address inequalities in graduation rates for underrepresented students
Development of HPD Clusters for MAGIC-II
MAGIC-II is the second imaging atmospheric Cherenkov telescope of the MAGIC
observatory, which has recently been inaugurated on Canary island of La Palma.
We are currently developing a new camera based on clusters of hybrid photon
detectors (HPD) for the upgrade of MAGIC-II. The photon detectors feature a
GaAsP photocathode and an avalanche diode as electron bombarded anodes with
internal gain, and were supplied by Hamamatsu Photonics K.K. (R9792U-40). The
HPD camera with high quantum efficiency will increase the MAGIC-II sensitivity
and lower the energy threshold. The basic performance of the HPDs has been
measured and a prototype of an HPD cluster has been developed to be mounted on
MAGIC-II. Here we report on the status of the HPD cluster and the project of
eventually using HPD clusters in the central area of the MAGIC-II camera.Comment: Contribution to the 31st ICRC, Lodz, Poland, July 200
Autonomous multi-dimensional slicing for large-scale distributed systems
Slicing is a distributed systems primitive that allows to autonomously partition a large set of nodes based on node-local attributes. Slicing is decisive for automatically provisioning system resources for different services, based on their requirements or importance. One of the main limitations of existing slicing protocols is that only single dimension attributes are considered for partitioning. In practical settings, it is often necessary to consider best compromises for an ensemble of metrics.
In this paper we propose an extension of the slicing primitive that allows multi-attribute distributed systems slicing. Our protocol employs a gossip-based approach that does not require centralized knowledge and allows self-organization. It leverages the notion of domination between nodes, forming a partial order between multi-dimensional points, in a similar way to SkyLine queries for databases. We evaluate and demonstrate the interest of our approach using large-scale simulations.This work received support from the Portuguese Foundation for Science and Technology under grant SFRH/BD/71476/2010
Longitudinal fluorescence in situ hybridization reveals cytogenetic evolution in myeloma relapsing after autologous transplantation
To investigate cytogenetic evolution after upfront autologous stem cell
transplantation for newly diagnosed myeloma we retrospectively analyzed
fluorescence in situ hybridization results of 128 patients with paired bone
marrow samples from the time of primary diagnosis and at relapse. High-risk
cytogenetic abnormalities (deletion 17p and/or gain 1q21) occurred more
frequently after relapse (odds ratio: 6.33; 95% confidence interval:
1.86–33.42; P<0.001). No significant changes were observed for defined IGH
translocations [t(4;14); t(11;14); t(14;16)] or hyperdiploid karyotypes
between primary diagnosis and relapse. IGH translocations with unknown
partners occurred more frequently at relapse. New deletion 17p and/or gain
1q21 were associated with cytogenetic heterogeneity, since some de novo
lesions with different copy numbers were present only in subclones. No
distinct baseline characteristics were associated with the occurrence of new
high-risk cytogenetic abnormalities after progression. Patients who relapsed
after novel agent-based induction therapy had an increased risk of developing
high-risk aberrations (odds ratio 10.82; 95% confidence interval: 1.65–127.66;
P=0.03) compared to those who were treated with conventional chemotherapy.
Survival analysis revealed dismal outcomes regardless of whether high-risk
aberrations were present at baseline (hazard ratio, 3.53; 95% confidence
interval: 1.53–8.14; P=0.003) or developed at relapse only (hazard ratio,
3.06; 95% confidence interval: 1.09–8.59; P=0.03). Our results demonstrate
cytogenetic evolution towards high-risk disease after autologous
transplantation and underline the importance of repeated genetic testing in
relapsed myeloma (EudraCT number of the HD4 trial: 2004-000944-26)
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