8 research outputs found
Rhythmogenic neuronal networks, pacemakers, and k-cores
Neuronal networks are controlled by a combination of the dynamics of
individual neurons and the connectivity of the network that links them
together. We study a minimal model of the preBotzinger complex, a small
neuronal network that controls the breathing rhythm of mammals through periodic
firing bursts. We show that the properties of a such a randomly connected
network of identical excitatory neurons are fundamentally different from those
of uniformly connected neuronal networks as described by mean-field theory. We
show that (i) the connectivity properties of the networks determines the
location of emergent pacemakers that trigger the firing bursts and (ii) that
the collective desensitization that terminates the firing bursts is determined
again by the network connectivity, through k-core clusters of neurons.Comment: 4+ pages, 4 figures, submitted to Phys. Rev. Let
The Mutyh Base Excision Repair Gene Influences the Inflammatory Response in a Mouse Model of Ulcerative Colitis
BACKGROUND: The Mutyh DNA glycosylase is involved in the repair of oxidized DNA bases. Mutations in the human MUTYH gene are responsible for colorectal cancer in familial adenomatous polyposis. Since defective DNA repair genes might contribute to the increased cancer risk associated with inflammatory bowel diseases, we compared the inflammatory response of wild-type and Mutyh(-/-) mice to oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: The severity of colitis, changes in expression of genes involved in DNA repair and inflammation, DNA 8-oxoguanine levels and microsatellite instability were analysed in colon of mice treated with dextran sulfate sodium (DSS). The Mutyh(-/-) phenotype was associated with a significant accumulation of 8-oxoguanine in colon DNA of treated mice. A single DSS cycle induced severe acute ulcerative colitis in wild-type mice, whereas lesions were modest in Mutyh(-/-) mice, and this was associated with moderate variations in the expression of several cytokines. Eight DSS cycles caused chronic colitis in both wild-type and Mutyh(-/-) mice. Lymphoid hyperplasia and a significant reduction in Foxp3(+) regulatory T cells were observed only in Mutyh(-/-) mice. CONCLUSIONS: The findings indicate that, in this model of ulcerative colitis, Mutyh plays a major role in maintaining intestinal integrity by affecting the inflammatory response
Health Professional Training and Capacity Strengthening Through International Academic Partnerships: The First Five Years of the Human Resources for Health Program in Rwanda
Abstract
Background: The Rwanda Human Resources for Health Program (HRH Program) is a 7-year (2012-2019) health
professional training initiative led by the Government of Rwanda with the goals of training a large, diverse, and competent
health workforce and strengthening the capacity of academic institutions in Rwanda.
Methods: The data for this organizational case study was collected through official reports from the Rwanda Ministry of
Health (MoH) and 22 participating US academic institutions, databases from the MoH and the College of Medicine and
Health Sciences (CMHS) in Rwanda, and surveys completed by the co-authors.
Results: In the first 5 years of the HRH Program, a consortium of US academic institutions has deployed an average of 99
visiting faculty per year to support 22 training programs, which are on track to graduate almost 4600 students by 2019.
The HRH Program has also built capacity within the CMHS by promoting the recruitment of Rwandan faculty and the
establishment of additional partnerships and collaborations with the US academic institutions.
Conclusion: The milestones achieved by the HRH Program have been substantial although some challenges persist.
These challenges include adequately supporting the visiting faculty; pairing them with Rwandan faculty (twinning);
ensuring strong communication and coordination among stakeholders; addressing mismatches in priorities between
donors and implementers; the execution of a sustainability strategy; and the decision by one of the donors not to renew
funding beyond March 2017. Over the next 2 academic years, it is critical for the sustainability of the 22 training programs
supported by the HRH Program that the health-related Schools at the CMHS significantly scale up recruitment of new
Rwandan faculty. The HRH Program can serve as a model for other training initiatives implemented in countries affected
by a severe shortage of health professionals
Modelling human choices: MADeM and decision‑making
Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)
The ExoMars rover and Pasteur payload Phase A study: an approach to experimental astrobiology
The Aurora programme is the European Space Agency programme of planetary exploration focused primarily on Mars. Although the long-term goals of Aurora are uncertain, the early phases of the Aurora programme are based on a number of robotic explorer missions - the first of these is the ExoMars rover mission currently scheduled for launch in 2013 (originally 2011). The ExoMars rover - developed during a Phase A study - is a 240 kg Mars rover supporting a 40 kg payload (called Pasteur) of scientific instruments specifically designed for astrobiological prospecting to search for evidence of extant or extinct life. In other words, ExoMars represents a new approach to experimental astrobiology in which scientific instruments are robotically deployed at extraterrestrial environments of astrobiological interest. Presented is an outline of the design of the rover, its robotic technology, its instrument complement and aspects of the design decisions made. ExoMars represents a highly challenging mission, both programmatically and technologically. Some comparisons are made with the highly succ