629 research outputs found
Inferring waypoints in the absence of knowledge of driving style
We present an algorithm for predicting intervals which contain waypoints from a GPS trace of a multi-part trip without having access to historical data about the driver or any other aggregated data sets. We assume the driverβs driving style is not known, but that it can be approximated by one of a set of cost preferences. The method uses a set of repeated forward and backward searches along the trace, where each of the searches represents one of the driving costs. We evaluate the algorithm empirically on multi-part trips on real route maps. The algorithm selects the results of the search with the fewest number of intervals and we achieve over 95% recall on estimating waypoints while the intervals cover less than 9% of the tra
Inferring waypoints using shortest paths
We present a method for reconstructing intermediate destinations from a GPS trace of a multi-part trip, without access to aggregated statistics or datasets of previous traces. The method uses repeated forwards and backwards shortest-path searches. We evaluate the algorithm empirically on multi-part trips on real route maps. We show that the algorithm can achieve up to 97% recall, and that the algorithm degrades gracefully as the GPS traces become sparse and irregular
100 years of chemistry at Rhodes University
The history of Grahamstown is well documented and two books deal with the history of Rhodes University.1,2 Although the Chemistry Department was one of the founding departments, coverage in the official histories is minimal and sometimes inaccurate or misleading. The Rhodes University Centenary is an appropriate time to look back on some of the achievements of the department and some of its graduates over the past 100 years
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Electrophysiological Guidance of Epidural Electrode Array Implantation over the Human Lumbosacral Spinal Cord to Enable Motor Function after Chronic Paralysis.
Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI
The N-terminal intrinsically disordered domain of mgm101p is localized to the mitochondrial nucleoid.
The mitochondrial genome maintenance gene, MGM101, is essential for yeasts that depend on mitochondrial DNA replication. Previously, in Saccharomyces cerevisiae, it has been found that the carboxy-terminal two-thirds of Mgm101p has a functional core. Furthermore, there is a high level of amino acid sequence conservation in this region from widely diverse species. By contrast, the amino-terminal region, that is also essential for function, does not have recognizable conservation. Using a bioinformatic approach we find that the functional core from yeast and a corresponding region of Mgm101p from the coral Acropora millepora have an ordered structure, while the N-terminal domains of sequences from yeast and coral are predicted to be disordered. To examine whether ordered and disordered domains of Mgm101p have specific or general functions we made chimeric proteins from yeast and coral by swapping the two regions. We find, by an in vivo assay in S.cerevisiae, that the ordered domain of A.millepora can functionally replace the yeast core region but the disordered domain of the coral protein cannot substitute for its yeast counterpart. Mgm101p is found in the mitochondrial nucleoid along with enzymes and proteins involved in mtDNA replication. By attaching green fluorescent protein to the N-terminal disordered domain of yeast Mgm101p we find that GFP is still directed to the mitochondrial nucleoid where full-length Mgm101p-GFP is targeted
Behavioural changes in drivers experiencing highly-automated vehicle control in varying traffic conditions
Previous research has indicated that high levels of vehicle automation can result in reduced driver situation awareness, but has also highlighted potential benefits of such future vehicle designs through enhanced safety and reduced driver workload. Well-designed automation allows driversβ visual attention to be focused away from the roadway and toward secondary, in-vehicle tasks. Such tasks may be pleasant distractions from the monotony of system monitoring. This study was undertaken to investigate the impact of voluntary secondary task uptake on the system supervisory responsibilities of drivers experiencing highly-automated vehicle control. Independent factors of Automation Level (manual control, highly-automated) and Traffic Density (light, heavy) were manipulated in a repeated-measures experimental design. 49 drivers participated using a high-fidelity driving simulator that allowed drivers to see, hear and, crucially, feel the impact of their automated vehicle handling. Drivers experiencing automation tended to refrain from behaviours that required them to temporarily retake manual control, such as overtaking, resulting in an increased journey time. Automation improved safety margins in car following, however this was restricted to conditions of light surrounding traffic. Participants did indeed become more heavily involved with the in-vehicle entertainment tasks than they were in manual driving, affording less visual attention to the road ahead. This might suggest that drivers are happy to forgo their supervisory responsibilities in preference of a more entertaining highly-automated drive. However, they did demonstrate additional attention to the roadway in heavy traffic, implying that these responsibilities are taken more seriously as the supervisory demand of vehicle automation increases. These results may dampen some concerns over driver underload with vehicle automation, assuming vehicle manufacturers embrace the need for positive system feedback and drivers also fully appreciate their supervisory obligations in such future vehicle designs
Current Murine Models and New Developments in H3K27M Diffuse Midline Gliomas
Diffuse Midline Gliomas with Histone 3-Lysine-27-Methionine (H3K27M) mutation constitute the majority of Diffuse Intrinsic Pontine Glioma (DIPG), which is the most aggressive form of pediatric glioma with a dire prognosis. DIPG are lethal tumors found in younger children with a median survival <1 year from diagnosis. Discovery of the characteristic H3K27M mutations offers opportunity and hope for development of targeted therapies for this deadly disease. The H3K27M mutation, likely through epigenetic alterations in specific H3 lysine trimethylation levels and subsequent gene expression, plays a significant role in pathogenesis of DIPG. Animal models accurately depicting molecular characteristics of H3K27M DIPG are important to elucidate underlying pathologic events and for preclinical drug evaluation. Here we review the past and present DIPG models and describe our efforts developing patient derived cell lines and xenografts from pretreated surgical specimens. Pre-treated surgical samples retain the characteristic genomic and phenotypic hallmarks of DIPG and establish orthotopic tumors in the mouse brainstem that recapitulate radiographic and morphological features of the original human DIPG tumor. These models that contain the H3K27M mutation constitute a valuable tool to further study this devastating disease and ultimately may uncover novel therapeutic vulnerabilities
The benefits of participatory methodologies to develop effective community dialogue in the context of a microbicide trial feasibility study in Mwanza, Tanzania
BACKGROUND: As part of a microbicide trial feasibility study among women at high-risk of HIV and sexually transmitted infections in Mwanza City, northern Tanzania we used participatory research tools to facilitate open dialogue and partnership between researchers and study participants. METHODS: A mobile community-based sexual & reproductive health service was established in ten city wards. Wards were divided into seventy-eight geographical clusters and representatives at cluster and ward level elected in a process facilitated by the projects Community Liaison Officer. A city-level Community Advisory Committee (CAC) with representatives from each ward was established. Workshops and community meetings at ward and city-level were conducted to explore project-related concerns using tools adapted from participatory learning and action techniques such as listing, scoring, ranking, chapatti diagrams and pair-wise matrices. RESULTS: Key issues identified included beliefs that blood specimens were being sold for witchcraft purposes; worries about specula not being clean; inadequacy of transport allowances; and delays in reporting laboratory test results to participants. To date, the project has responded by inviting members of the CAC to visit the laboratory to observe how blood and genital specimens are prepared; demonstrated the use of the autoclave to community representatives; raised reimbursement levels; introduced HIV rapid testing in the clinic; and streamlined laboratory reporting procedures. CONCLUSIONS: Participatory techniques were instrumental in promoting meaningful dialogue between the research team, study participants and community representatives in Mwanza, allowing researchers and community representatives to gain a shared understanding of project-related priority areas for intervention
A developmental approach to diversifying neuroscience through effective mentorship practices: perspectives on cross-identity mentorship and a critical call to action.
Many early-career neuroscientists with diverse identities may not have mentors who are more advanced in the neuroscience pipeline and have a congruent identity due to historic biases, laws, and policies impacting access to education. Cross-identity mentoring relationships pose challenges and power imbalances that impact the retention of diverse early career neuroscientists, but also hold the potential for a mutually enriching and collaborative relationship that fosters the mentee\u27s success. Additionally, the barriers faced by diverse mentees and their mentorship needs may evolve with career progression and require developmental considerations. This article provides perspectives on factors that impact cross-identity mentorship from individuals participating in Diversifying the Community of Neuroscience (CNS)-a longitudinal, National Institute of Neurological Disorders and Stroke (NINDS) R25 neuroscience mentorship program developed to increase diversity in the neurosciences. Participants in Diversifying CNS were comprised of 14 graduate students, postdoctoral fellows, and early career faculty who completed an online qualitative survey on cross-identity mentorship practices that impact their experience in neuroscience fields. Qualitative survey data were analyzed using inductive thematic analysis and resulted in four themes across career levels: (1) approach to mentorship and interpersonal dynamics, (2) allyship and management of power imbalance, (3) academic sponsorship, and (4) institutional barriers impacting navigation of academia. These themes, along with identified mentorship needs by developmental stage, provide insights mentors can use to better support the success of their mentees with diverse intersectional identities. As highlighted in our discussion, a mentor\u27s awareness of systemic barriers along with active allyship are foundational for their role
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