VPRTempo: A Fast Temporally Encoded Spiking Neural Network for Visual Place Recognition

Spiking Neural Networks (SNNs) are at the forefront of neuromorphic computing thanks to their potential energy-efficiency, low latencies, and capacity for continual learning. While these capabilities are well suited for robotics tasks, SNNs have seen limited adaptation in this field thus far. This work introduces a SNN for Visual Place Recognition (VPR) that is both trainable within minutes and queryable in milliseconds, making it well suited for deployment on compute-constrained robotic systems. Our proposed system, VPRTempo, overcomes slow training and inference times using an abstracted SNN that trades biological realism for efficiency. VPRTempo employs a temporal code that determines the timing of a single spike based on a pixel's intensity, as opposed to prior SNNs relying on rate coding that determined the number of spikes; improving spike efficiency by over 100%. VPRTempo is trained using Spike-Timing Dependent Plasticity and a supervised delta learning rule enforcing that each output spiking neuron responds to just a single place. We evaluate our system on the Nordland and Oxford RobotCar benchmark localization datasets, which include up to 27k places. We found that VPRTempo's accuracy is comparable to prior SNNs and the popular NetVLAD place recognition algorithm, while being several orders of magnitude faster and suitable for real-time deployment -- with inference speeds over 50 Hz on CPU. VPRTempo could be integrated as a loop closure component for online SLAM on resource-constrained systems such as space and underwater robots.Comment: 8 pages, 3 figures, accepted to the IEEE International Conference on Robotics and Automation (ICRA) 202

New constraints on equatorial temperatures during a Late Neoproterozoic snowball Earth glaciation

Intense glaciation during the end of Cryogenian time (∼635 million years ago) marks the coldest climate state in Earth history – a time when glacial deposits accumulated at low, tropical paleolatitudes. The leading idea to explain these deposits, the snowball Earth hypothesis, predicts globally frozen surface conditions and subfreezing temperatures, with global climate models placing surface temperatures in the tropics between −20 °C and −60 °C. However, precise paleosurface temperatures based upon geologic constraints have remained elusive and the global severity of the glaciation undetermined. Here we make new geologic observations of tropical periglacial, aeolian and fluvial sedimentary structures formed during the end-Cryogenian, Marinoan glaciation in South Australia; these observations allow us to constrain ancient surface temperatures. We find periglacial sand wedges and associated deformation suggest that ground temperatures were sufficiently warm to allow for ductile deformation of a sandy regolith. The wide range of deformation structures likely indicate the presence of a paleoactive layer that penetrated 2–4 m below the ground surface. These observations, paired with a model of ground temperature forced by solar insolation, constrain the local mean annual surface temperature to within a few degrees of freezing. This temperature constraint matches well with our observations of fluvial deposits, which require temperatures sufficiently warm for surface runoff. Although this estimate coincides with one of the coldest near sea-level tropical temperatures in Earth history, if these structures represent peak Marinaon glacial conditions, they do not support the persistent deep freeze of the snowball Earth hypothesis. Rather, surface temperatures near 0 °C allow for regions of seasonal surface melting, atmosphere–ocean coupling and possible tropical refugia for early metazoans. If instead these structures formed during glacial onset or deglaciation, then they have implications for the timescale and character for the transition into or out of a snowball state

Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury

Study Design: Systematic review. Objective: To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI). Methods: An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI. Results: The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema. Conclusions: Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies. © 2017, © The Author(s) 2017

Electromagnetic Field Study

The Oregon Wave Energy Trust (OWET) commissioned this study to develop protocols and methods to achieve affordable, reliable, and repeatable electromagnetic (EM) measurements in the near-shore environment. The study was conducted in several stages, with a number of technical reports provided at each stage to document and describe findings. The major objective of this project was to demonstrate an ability to achieve affordable, reliable, repeatable EMF measurement protocols in support of wave and tidal energy technology development and deployment. The document contains an executive summer with conclusions and recommendations as well as 13 technical reports

VIPR: A probabilistic algorithm for analysis of microbial detection microarrays

<p>Abstract</p> <p>Background</p> <p>All infectious disease oriented clinical diagnostic assays in use today focus on detecting the presence of a single, well defined target agent or a set of agents. In recent years, microarray-based diagnostics have been developed that greatly facilitate the highly parallel detection of multiple microbes that may be present in a given clinical specimen. While several algorithms have been described for interpretation of diagnostic microarrays, none of the existing approaches is capable of incorporating training data generated from positive control samples to improve performance.</p> <p>Results</p> <p>To specifically address this issue we have developed a novel interpretive algorithm, VIPR (<b>V</b>iral <b>I</b>dentification using a <b>PR</b>obabilistic algorithm), which uses Bayesian inference to capitalize on empirical training data to optimize detection sensitivity. To illustrate this approach, we have focused on the detection of viruses that cause hemorrhagic fever (HF) using a custom HF-virus microarray. VIPR was used to analyze 110 empirical microarray hybridizations generated from 33 distinct virus species. An accuracy of 94% was achieved as measured by leave-one-out cross validation. <it>Conclusions</it></p> <p>VIPR outperformed previously described algorithms for this dataset. The VIPR algorithm has potential to be broadly applicable to clinical diagnostic settings, wherein positive controls are typically readily available for generation of training data.</p

Screening for colorectal cancer. Collaboration among politicians and scientists is necessary

Hægt er að lesa greinina í heild sinni með því að smella á hlekkinn View/OpenColorectal cancer is one of the most common cancers in the western world. It is especially common in the Nordic countries. In many of the European countries and in the United States colonoscopy is recommended as a screening procedure for CRC. However, there are no randomized studies of the effects of the method on incidence, mortality, possible complications or negative effects on the population. Public pressure to have screening for CRC with colonoscopy will probably increase heavily in the next years to come. We fear that colonoscopy will be introduced as a screening method without proper scientific support. Therefore we want to argue for a common Nordic randomized study on population screening with colonoscopy.Krabbamein í ristli og endaþarmi er eitt af algengustu krabbameinum í hinum vestræna heimi, og sérstaklega er það algengt á Norðurlöndum. Í mörgum Evrópulöndum og Bandaríkjunum er ristilspeglun ráðlögð sem skimunaraðferð fyrir þessu krabbameini. Það hafa samt ekki verið gerðar slembirannsóknir á áhrifum aðferðarinnar á nýgengi, dánartíðni, mögulega fylgikvilla eða neikvæð áhrif á almenning. Þrýstingur almennings á að fá skimun fyrir meininu með ristilspeglun mun líklega aukast mikið á næstu árum. Það er hætta á því að ristilspeglun sem skimunaraðferð verði innleidd án nægilegrar vísindalegrar undirstöðu. Þess vegna viljum við færa rök fyrir mikilvægi þess að gerð verði samnorræn slembirannsókn á skimun með ristilspeglun meðal almennings

Patient, Physician, and Payment Predictors of Statin Adherence

BACKGROUND: Although many patient, physician, and payment predictors of adherence have been described, knowledge of their relative strength and overall ability to explain adherence is limited. OBJECTIVES: To measure the contributions of patient, physician, and payment predictors in explaining adherence to statins RESEARCH DESIGN: Retrospective cohort study using administrative data SUBJECTS: 14,257 patients insured by Horizon Blue Cross Blue Shield of New Jersey (BCBSNJ) who were newly prescribed a statin cholesterol-lowering medication MEASURES: Adherence to statin medication was measured during the year after the initial prescription, based on proportion of days covered (PDC). The impact of patient, physician, and payment predictors of adherence were evaluated using multivariate logistic regression. The explanatory power of these models was evaluated with C statistics, a measure of the goodness of fit. RESULTS: Overall, 36.4% of patients were fully adherent. Older patient age, male gender, lower neighborhood percent black composition, higher median income, and fewer number of emergency department (ED) visits were significant patient predictors of adherence. Having a statin prescribed by a cardiologist, a patient's primary care physician, or a US medical graduate were significant physician predictors of adherence. Lower copayments also predicted adherence. All of our models had low explanatory power. Multivariate models including patient covariates only had greater explanatory power (C = 0.613) than models with physician variables only (C = 0.566) or copayments only (C = 0.543). A fully specified model had only slightly more explanatory power (C = 0.633) than the model with patient characteristics alone. CONCLUSIONS: Despite relatively comprehensive claims data on patients, physicians, and out-of-pocket costs, our overall ability to explain adherence remains poor. Administrative data likely do not capture many complex mechanisms underlying adherence.Economic

Implementation of clinical guidelines in Brazil : should academic detailing be used?

Objective: The Brazilian National Health System provides high cost medicines through the Specialized Component of Pharmaceutical Assistance in accordance with adherence to agreed Clinical Guidelines. However, physician compliance to these Guidelines, as well as the barriers and facilitators related to them and the influence on the subsequent quality of care provided is unknown. Consequently, the objectives of this paper are to undertake a review of international experiences and scientific publications of a strategy to disseminate and communicate guidelines to physicians through Academic Detailing. Subsequently use the findings to develop and conduct a pilot Academic Detailing Program in Brazil targeting specialists who prescribe medicines for patients with Alzheimer’s disease, which are part of the Specialized Component of Pharmaceutical Assistance. Methods: Review international experiences and scientific publications relating to academic detailing based on a thorough review of available literature including publications known to the co-authors. Develop and monitor physician acceptance of academic detailing for patients with Alzheimer’s Disease and the impact on future prescribing. Key findings: Based on the lessons learnt from the international experience and review, coupled with the initial experiences in Brazil, we conclude that conducting academic detailing to enhance the implementation and dissemination of clinical protocols and therapeutic guidelines in Brazil is worthwhile. We will be closely monitoring the outcome of the pilot academic detailing programme as a basis for developing future programmes to further improve the quality of prescribing in Brazil. Conclusion: Findings from the experiences are encouraging. This will be further explored to provide a basis for this approach in the future