233 research outputs found

    Stacked Capsule Autoencoders

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    Objects are composed of a set of geometrically organized parts. We introduce an unsupervised capsule autoencoder (SCAE), which explicitly uses geometric relationships between parts to reason about objects. Since these relationships do not depend on the viewpoint, our model is robust to viewpoint changes. SCAE consists of two stages. In the first stage, the model predicts presences and poses of part templates directly from the image and tries to reconstruct the image by appropriately arranging the templates. In the second stage, SCAE predicts parameters of a few object capsules, which are then used to reconstruct part poses. Inference in this model is amortized and performed by off-the-shelf neural encoders, unlike in previous capsule networks. We find that object capsule presences are highly informative of the object class, which leads to state-of-the-art results for unsupervised classification on SVHN (55%) and MNIST (98.7%). The code is available at https://github.com/google-research/google-research/tree/master/stacked_capsule_autoencodersComment: NeurIPS 2019; 14 pages, 7 figures, 4 tables, code is available at https://github.com/google-research/google-research/tree/master/stacked_capsule_autoencoder

    The first super-Earth Detection from the High Cadence and High Radial Velocity Precision Dharma Planet Survey

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    The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016-2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (R\approx100,000, 380-900nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013-2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star (V=4.4V=4.4 mag) on the sky with a super-Earth candidate. The planet candidate has a mass of 8.47±0.47MEarth\pm0.47M_{\rm Earth}, period of 42.38±0.0142.38\pm0.01 d, and eccentricity of 0.040.03+0.050.04^{+0.05}_{-0.03}. This RV signal was independently detected by Diaz et al. (2018), but they could not confirm if the signal is from a planet or from stellar activity. The orbital period of the planet is close to the rotation period of the star (39-44.5 d) measured from stellar activity indicators. Our high precision photometric campaign and line bisector analysis of this star do not find any significant variations at the orbital period. Stellar RV jitters modeled from star spots and convection inhibition are also not strong enough to explain the RV signal detected. After further comparing RV data from the star's active magnetic phase and quiet magnetic phase, we conclude that the RV signal is due to planetary-reflex motion and not stellar activity.Comment: 13 pages, 17 figures, Accepted for publication in MNRA

    The first super-Earth detection from the high cadence and high radial velocity precision Dharma Planet Survey

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    The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016–2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (⁠R≈100000⁠, 380–900 nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013–2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here, we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star (V = 4.4 mag) on the sky with a super-Earth candidate. The planet candidate has a mass of 8.47 ± 0.47MEarth, period of 42.38 ± 0.01 d, and eccentricity of 0.04+0.05−0.03⁠. This radial velocity (RV) signal was independently detected by Díaz et al., but they could not confirm if the signal is from a planet or stellar activity. The orbital period of the planet is close to the rotation period of the star (39–44.5 d) measured from stellar activity indicators. Our high precision photometric campaign and line bisector analysis of this star do not find any significant variations at the orbital period. Stellar RV jitters modelled from star-spots and convection inhibition are also not strong enough to explain the RV signal detected. After further comparing RV data from the star’s active magnetic phase and quiet magnetic phase, we conclude that the RV signal is due to planetary-reflex motion and not stellar activity

    Paternally expressed, imprinted insulin-like growth factor-2 in chorionic villi correlates significantly with birth weight

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    Context: Fetal growth involves highly complex molecular pathways. IGF2 is a key paternally expressed growth hormone that is critical for in utero growth in mice. Its role in human fetal growth has remained ambiguous, as it has only been studied in term tissues. Conversely the maternally expressed growth suppressor, PHLDA2, has a significant negative correlation between its term placental expression and birth weight. Objective: The aim of this study is to address the role in early gestation of expression of IGF1, IGF2, their receptors IGF1R and IGF2R, and PHLDA2 on term birth weight. Design: Real-time quantitative PCR was used to investigate mRNA expression of IGF1, IGF2, IGF1R, IGF2R and PHLDA2 in chorionic villus samples (CVS) (n = 260) collected at 11–13 weeks’ gestation. Expression was correlated with term birth weight using statistical package R including correction for several confounding factors. Results: Transcript levels of IGF2 and IGF2R revealed a significant positive correlation with birth weight (0.009 and 0.04, respectively). No effect was observed for IGF1, IGF1R or PHLDA2 and birth weight. Critically, small for gestational age (SGA) neonates had significantly lower IGF2 levels than appropriate for gestational age neonates (p = 3?661027 ). Interpretation: Our findings show that IGF2 mRNA levels at 12 weeks gestation could provide a useful predictor of future fetal growth to term, potentially predicting SGA babies. SGA babies are known to be at a higher risk for type 2 diabetes. This research reveals an imprinted, parentally driven rheostat for in utero growth

    Adverse childhood experiences and prescription drug use in a cohort study of adult HMO patients

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    <p>Abstract</p> <p>Background</p> <p>Prescription drugs account for approximately 11% of national health expenditures. Prior research on adverse childhood experiences (ACEs), which include common forms of child maltreatment and related traumatic stressors, has linked them to numerous health problems. However, data about the relationship of these experiences to prescription drug use are scarce.</p> <p>Method</p> <p>We used the ACE Score (an integer count of 8 different categories of ACEs) as a measure of cumulative exposure to traumatic stress during childhood. We prospectively assessed the relationship of the Score to prescription drug use in a cohort of 15,033 adult HMO patients (mean follow-up: 6.1 years) and assessed mediation of this relationship by documented ACE-related health and social problems.</p> <p>Results</p> <p>Nearly 1.2 million prescriptions were recorded; prescriptions rates increased in a graded fashion as the ACE Score increased (p for trend < 0.0001). Compared to persons with an ACE Score of 0, persons with a Score ≥ 5 had rates increased by 40%; graded relationships were seen for all age groups (18–44, 45–64, and 65–89 years) (p for trend < 0.01). Graded relationships were observed for the risk of being in the upper decile of number of classes of drugs used; persons with scores of ≥ 5 had this risk increased 2-fold. Adjustment for ACE-related health problems reduced the strength of the associations by more than 60%.</p> <p>Conclusion</p> <p>ACEs substantially increase the number of prescriptions and classes of drugs used for as long as 7 or 8 decades after their occurrence. The increases in prescription drug use were largely mediated by documented ACE-related health and social problems.</p

    Segregation of object and background motion in the retina

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    An important task in vision is to detect objects moving within a stationary scene. During normal viewing this is complicated by the presence of eye movements that continually scan the image across the retina, even during fixation. To detect moving objects, the brain must distinguish local motion within the scene from the global retinal image drift due to fixational eye movements. We have found that this process begins in the retina: a subset of retinal ganglion cells responds to motion in the receptive field centre, but only if the wider surround moves with a different trajectory. This selectivity for differential motion is independent of direction, and can be explained by a model of retinal circuitry that invokes pooling over nonlinear interneurons. The suppression by global image motion is probably mediated by polyaxonal, wide-field amacrine cells with transient responses. We show how a population of ganglion cells selective for differential motion can rapidly flag moving objects, and even segregate multiple moving objects

    Complications and pitfalls of lumbar interlaminar and transforaminal epidural injections

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    Lumbar interlaminar and transforaminal epidural injections are used in the treatment of lumbar radicular pain and other lumbar spinal pain syndromes. Complications from these procedures arise from needle placement and the administration of medication. Potential risks include infection, hematoma, intravascular injection of medication, direct nerve trauma, subdural injection of medication, air embolism, disc entry, urinary retention, radiation exposure, and hypersensitivity reactions. The objective of this article is to review the complications of lumbar interlaminar and transforaminal epidural injections and discuss the potential pitfalls related to these procedures. We performed a comprehensive literature review through a Medline search for relevant case reports, clinical trials, and review articles. Complications from lumbar epidural injections are extremely rare. Most if not all complications can be avoided by careful technique with accurate needle placement, sterile precautions, and a thorough understanding of the relevant anatomy and contrast patterns on fluoroscopic imaging

    Effectiveness and cost-effectiveness of a group-based pain self-management intervention for patients undergoing total hip replacement: Feasibility study for a randomized controlled trial

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    Background: Total hip replacement (THR) is a common elective surgical procedure and can be effective for reducing chronic pain. However, waiting times can be considerable. A pain self-management intervention may provide patients with skills to more effectively manage their pain and its impact during their wait for surgery. This study aimed to evaluate the feasibility of conducting a randomized controlled trial to assess the effectiveness and cost-effectiveness of a group-based pain self-management course for patients undergoing THR.Methods: Patients listed for a THR at one orthopedic center were posted a study invitation pack. Participants were randomized to attend a pain self-management course plus standard care or standard care only. The lay-led course was delivered by Arthritis Care and consisted of two half-day sessions prior to surgery and one full-day session after surgery. Participants provided outcome and resource-use data using a diary and postal questionnaires prior to surgery and one month, three months and six months after surgery. Brief telephone interviews were conducted with non-participants to explore barriers to participation.Results: Invitations were sent to 385 eligible patients and 88 patients (23%) consented to participate. Interviews with 57 non-participants revealed the most common reasons for non-participation were views about the course and transport difficulties. Of the 43 patients randomized to the intervention group, 28 attended the pre-operative pain self-management sessions and 11 attended the post-operative sessions. Participant satisfaction with the course was high, and feedback highlighted that patients enjoyed the group format. Retention of participants was acceptable (83% of recruited patients completed follow-up) and questionnaire return rates were high (72% to 93%), with the exception of the pre-operative resource-use diary (35% return rate). Resource-use completion rates allowed for an economic evaluation from the health and social care payer perspective.Conclusions: This study highlights the importance of feasibility work prior to a randomized controlled trial to assess recruitment methods and rates, barriers to participation, logistics of scheduling group-based interventions, acceptability of the intervention and piloting resource use questionnaires to improve data available for economic evaluations. This information is of value to researchers and funders in the design and commissioning of future research.Trial registration: Current Controlled Trials ISRCTN52305381. © 2014 Wylde et al.; licensee BioMed Central Ltd

    Motor control or graded activity exercises for chronic low back pain? A randomised controlled trial

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    Background: Chronic low back pain remains a major health problem in Australia and around the world. Unfortunately the majority of treatments for this condition produce small effects because not all patients respond to each treatment. It appears that only 25-50% of patients respond to exercise. The two most popular types of exercise for low back pain are graded activity and motor control exercises. At present however, there are no guidelines to help clinicians select the best treatment for a patient. As a result, time and money are wasted on treatments which ultimately fail to help the patient
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