2,787 research outputs found
Surface Edge Explorer (SEE): Planning Next Best Views Directly from 3D Observations
Surveying 3D scenes is a common task in robotics. Systems can do so
autonomously by iteratively obtaining measurements. This process of planning
observations to improve the model of a scene is called Next Best View (NBV)
planning.
NBV planning approaches often use either volumetric (e.g., voxel grids) or
surface (e.g., triangulated meshes) representations. Volumetric approaches
generalise well between scenes as they do not depend on surface geometry but do
not scale to high-resolution models of large scenes. Surface representations
can obtain high-resolution models at any scale but often require tuning of
unintuitive parameters or multiple survey stages.
This paper presents a scene-model-free NBV planning approach with a density
representation. The Surface Edge Explorer (SEE) uses the density of current
measurements to detect and explore observed surface boundaries. This approach
is shown experimentally to provide better surface coverage in lower computation
time than the evaluated state-of-the-art volumetric approaches while moving
equivalent distances
Multimotion Visual Odometry (MVO): Simultaneous Estimation of Camera and Third-Party Motions
Estimating motion from images is a well-studied problem in computer vision
and robotics. Previous work has developed techniques to estimate the motion of
a moving camera in a largely static environment (e.g., visual odometry) and to
segment or track motions in a dynamic scene using known camera motions (e.g.,
multiple object tracking).
It is more challenging to estimate the unknown motion of the camera and the
dynamic scene simultaneously. Most previous work requires a priori object
models (e.g., tracking-by-detection), motion constraints (e.g., planar motion),
or fails to estimate the full SE(3) motions of the scene (e.g., scene flow).
While these approaches work well in specific application domains, they are not
generalizable to unconstrained motions.
This paper extends the traditional visual odometry (VO) pipeline to estimate
the full SE(3) motion of both a stereo/RGB-D camera and the dynamic scene. This
multimotion visual odometry (MVO) pipeline requires no a priori knowledge of
the environment or the dynamic objects. Its performance is evaluated on a
real-world dynamic dataset with ground truth for all motions from a motion
capture system.Comment: This updated manuscript corrects the experimental results published
in the proceedings of the 2018 IEEE/RSJ International Conference on
Intelligent Robots and Systems (IROS).. 8 Pages. 7 Figures. Video available
at https://www.youtube.com/watch?v=84tXCJOlj0
Masked Hypertension and Prehypertension: Diagnostic Overlap and Interrelationships With Left Ventricular Mass: The Masked Hypertension Study
Background Masked hypertension (MHT) and prehypertension (PHT) are both associated with an increase in cardiovascular disease (CVD) risk, relative to sustained normotension. This study examined the diagnostic overlap between MHT and PHT, and their interrelationships with left ventricular (LV) mass index (LVMI), a marker of cardiovascular end-organ damage.
Methods A research nurse performed three manual clinic blood pressure (CBP) measurements on three occasions over a 3-week period (total of nine readings, which were averaged) in 813 participants without treated hypertension from the Masked Hypertension Study, an ongoing worksite-based, population study. Twenty-four-hour ambulatory blood pressure (ABP) was assessed by using a SpaceLabs 90207 monitor. LVMI was determined by echocardiography in 784 (96.4%) participants.
Results Of the 813 participants, 769 (94.6%) had normal CBP levels (<140/90 mm Hg). One hundred and seventeen (15.2%) participants with normal CBP had MHT (normal CBP and mean awake ABP β₯135/85 mm Hg) and 287 (37.3%) had PHT (mean CBP 120β139/80β89 mm Hg). 83.8% of MHT participants had PHT and 34.1% of PHT participants had MHT. MHT was infrequent (3.9%) when CBP was optimal (<120/80 mm Hg). After adjusting for age, gender, body mass index (BMI), race/ethnicity, history of high cholesterol, history of diabetes, current smoking, family history of hypertension, and physical activity, compared with optimal CBP with MHT participants, LVMI was significantly greater in PHT without MHT participants and in PHT with MHT participants.
Conclusions In this community sample, there was substantial diagnostic overlap between MHT and PHT. The diagnosis of MHT using an ABP monitor may not be warranted for individuals with optimal CBP
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Gender Differences in Calls to 9-1-1 During an Acute Coronary Syndrome
Calling 911 during acute coronary syndromes (ACS) decreases time to treatment and may improve prognosis. Women may have more atypical ACS symptoms compared to men, but few data are available on differences in gender and ACS symptoms in calling 911. In this study, patient interviews and structured chart reviews were conducted to determine gender differences in calling 911. Calls to 911 were assessed by self-report and validated by medical chart review. Of the 476 patients studied, 292 (61%) were diagnosed with unstable angina and 184 (39%) with myocardial infarctions (MIs). Overall, only 23% of patients called 911. Similar percentages of women and men with unstable angina called 911 (15% and 13%, respectively, p = 0.59). In contrast, women with MIs were significantly more likely to call 911 than men (57% vs 28%, p <0.001). After adjustment for sociodemographic factors, health insurance status, history of MI, the left ventricular ejection fraction, Global Registry of Acute Coronary Events (GRACE) score, and ACS symptoms, women were 1.79 times more likely to call 911 during an MI than men (prevalence ratio 1.79, 95% confidence interval 1.22 to 2.64, p <0.01). In conclusion, the findings of the present study suggest that initiatives to increase calls to 911 are needed for women and men
Relation of Patients Living Without a Partner or Spouse to Being Physically Active After Acute Coronary Syndromes (from the PULSE Accelerometry Substudy)
Living alone is associated with adverse outcomes after acute coronary syndromes (ACS). One potential mediator of the relation between partner status and outcomes after ACS is physical activity. To evaluate the association of partner status with physical activity after ACS, data from 107 participants enrolled in the Prescription Use, Lifestyle, and Stress Evaluation (PULSE) study, a prospective observational study of post-ACS patients, were analyzed. Accelerometers were used to measure physical activity after hospital discharge. The primary outcome measure was a maximum 10 hours of daytime activity 1 month after discharge. One month after discharge from ACS hospitalizations, participants without a partner or spouse exhibited 24.4% lower daytime activity than those with a partner or spouse (p = 0.003). After controlling for age, gender, body mass index, Charlson co-morbidity index, and traditional psychosocial and clinical cardiovascular correlates of post-ACS physical activity, partner status remained an independent predictor of post-ACS physical activity (20.5% lower daytime activity among those without a partner or spouse, p = 0.008). In conclusion, in this study of accelerometer-measured physical activity after an ACS hospitalization, those without a partner or spouse exhibit significantly less physical activity than those with a partner or spouse 1 month after discharge from the hospital. Low physical activity may be an important mediator of the prognosis associated with partner status after ACS
A Study on Developer Perception of Transformation Languages for Refactoring
Although there is much research advancing state-of-art of program transformation tools, their application in industry source code change problems has not yet been gauged. In this context, the purpose of this paper is to better understand developer familiarity and comfort with these languages by conducting a survey. It poses, and answers, four research questions to understand how frequently source code transformation languages are applied to refactoring tasks, how well-known these languages are in industry, what developers think are obstacles to adoption, and what developer refactoring habits tell us about their current use, or underuse, of transformation languages. The results show that while source code transformation languages can fill a needed niche in refactoring, research must motivate their application. We provide explanations and insights based on data, aimed at the program transformation and refactoring communities, with a goal to motivate future research and ultimately improve industry adoption of transformation languages for refactoring tasks
Post-Traumatic Stress Disorder (PTSD) Symptoms Predict Delay to Hospital in Patients with Acute Coronary Syndrome
Background: Increased delay to hospital presentation with acute coronary syndrome (ACS) is associated with poor outcomes. While demographic factors associated with this delay have been well described, scarce data are available on the role of modifiable factors, such as psychosocial disorders, on pre-hospital delay. Patients with symptoms of post-traumatic stress disorder (PTSD) often avoid stressful situations and may delay presenting for care when they experience cardiac symptoms. It is unknown, however, whether PTSD symptoms negatively impact the time to presentation during an ACS. Methods: We assessed the relationship between PTSD symptoms and pre-hospital delay in 241 adults with an ACS in the ongoing Prescription Use, Lifestyle, Stress Evaluation (PULSE) study. Results: Overall, 66 % of patients were male; 40 % were Hispanic or Latino. The mean age was 61.9611.6 years old. PTSD symptoms were present in 17.8 % of patients. Pre-hospital delay was longer for patients with PTSD symptoms compared to those without [geometric mean: 25.8 hours (95 % CI 13.8 β 44.8) vs. 10.7 hours (95 % CI 8.3 β 13.8)]; P = 0.005. After multivariable adjustment for age, sex, ethnicity, depression, left ventricular ejection fraction and history of myocardial infarction, the mean pre-hospital delay was 173 % (95 % CI: 36 % β450%) longer for patients with versus without PTSD symptoms. Conclusion: Among patients presenting with an ACS, PTSD symptoms were independently associated with longer prehospita
Thermal Tolerances of the Spotted-Wing Drosophila Drosophila suzukii (Diptera: Drosophilidae)
The spotted-wing drosophila (Drosophila suzukii Matsumura) is an invasive species of Asian origin that is now widely distributed in North America and Europe. Because of the female’s serrated ovipositor, eggs are laid in preharvest fruit, causing large economic losses in cultivated berries and stone fruit. Modeling D. suzukii population dynamics and potential distribution will require information on its thermal tolerance. Large summer populations have been found in regions with severe winter conditions, though little is known about responses to prolonged low-temperature exposure. We used controlled chambers to examine D. suzukii fecundity, development rate, and mortality across a range of temperatures encompassing the upper and lower thresholds (5–35°C). Optimal temperatures ( Topt ) were found to be 28.2°C for the development of the egg-to-adult stage, and 22.9°C for reproductive output. No adult eclosion occurred below 8.1°C ( Tlower ) or above 30.9°C ( Tupper ). We also investigated survival outcomes following prolonged (42-d) low-temperature exposure to a simulated cold winter (−5, −3, −1, 1, 3, and 5°C). Adult survival was dependent on temperature, with a mean LT50 of 4.9°C. There were no effects of sex, mating status, geographic strain, and photoperiod preexposure on overwintering survival. Thirty-eight percent of females that were mated prior, but not after, prolonged low-temperature exposure produced viable offspring, suggesting that this species may undergo sperm storage. This study provides data on the thermal tolerances of D. suzukii , which can be used for models of D. suzukii population dynamics, degree-day, and distribution models
Observed Hostility and the Risk of Incident Ischemic Heart Disease: A Prospective Population Study From the 1995 Canadian Nova Scotia Health Survey
Objectives
The aim of this study was to examine the relation between hostility and incident ischemic heart disease (IHD) and to determine whether observed hostility is superior to patient-reported hostility for the prediction of IHD in a large, prospective observational study.
Background
Some studies have found that hostile patients have an increased risk of incident IHD. However, no studies have compared methods of hostility assessment or considered important psychosocial and cardiovascular risk factors as confounders. Furthermore, it is unknown whether all expressions of hostility carry equal risk or whether certain manifestations are more cardiotoxic.
Methods
We assessed the independent relationship between baseline observed hostility and 10-year incident IHD in 1,749 adults of the population-based Canadian Nova Scotia Health Survey.
Results
There were 149 (8.5%) incident IHD events (140 nonfatal, 9 fatal) during the 15,295 person-years of observation (9.74 events/1,000 person-years). Participants with any observed hostility had a greater risk of incident IHD than those without (p = 0.02); no such relation was found for patient-reported hostility. Those with any observed hostility had a significantly greater risk of incident IHD (hazard ratio: 2.06, 95% confidence interval: 1.04 to 4.08, p = 0.04), after adjusting for cardiovascular (age, sex, Framingham Risk Score) and psychosocial (depression, positive affect, patient-reported hostility, and anger) risk factors.
Conclusions
The presence of any observed hostility at baseline was associated with a 2-fold increased risk of incident IHD over 10 years of follow-up. Compared with patient-reported measures, observed hostility is a superior predictor of IHD
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