Efficient, Responsive, and Robust Hopping on Deformable Terrain

Legged robot locomotion is hindered by a mismatch between applications where legs can outperform wheels or treads, most of which feature deformable substrates, and existing tools for planning and control, most of which assume flat, rigid substrates. In this study we focus on the ramifications of plastic terrain deformation on the hop-to-hop energy dynamics of a spring-legged monopedal hopping robot animated by a switched-compliance energy injection controller. From this deliberately simple robot-terrain model, we derive a hop-to-hop energy return map, and we use physical experiments and simulations to validate the hop-to-hop energy map for a real robot hopping on a real deformable substrate. The dynamical properties (fixed points, eigenvalues, basins of attraction) of this map provide insights into efficient, responsive, and robust locomotion on deformable terrain. Specifically, we identify constant-fixed-point surfaces in a controller parameter space that suggest it is possible to tune control parameters for efficiency or responsiveness while targeting a desired gait energy level. We also identify conditions under which fixed points of the energy map are globally stable, and we further characterize the basins of attraction of fixed points when these conditions are not satisfied. We conclude by discussing the implications of this hop-to-hop energy map for planning, control, and estimation for efficient, agile, and robust legged locomotion on deformable terrain.Comment: 17 pages, 13 figures, submitted to IEEE Transactions on Robotic

The USNO-B Catalog

USNO-B is an all-sky catalog that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,042,618,261 objects derived from 3,643,201,733 separate observations. The data were obtained from scans of 7,435 Schmidt plates taken for the various sky surveys during the last 50 years. USNO-B1.0 is believed to provide all-sky coverage, completeness down to V = 21, 0.2 arcsecond astrometric accuracy at J2000, 0.3 magnitude photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from non-stellar objects. A brief discussion of various issues is given here, but the actual data are available from http://www.nofs.navy.mil and other sites.Comment: Accepted by Astronomical Journa

Applications of Laboratory Technology in the Evaluation of the Risk of Rabies Transmissions by Biting Dogs and Cats

While rabies is not a common disease in domestic animal species of the United States, potential exposures to rabies in the form of bites are very common and increasing. A nationwide study conducted among general hospitals shows that 1 percent of emergency room visits are for animal bites, of which 80-90 percent are inflicted by the dog (Callaham 1980). This figure is conservative, as the study did not include pediatric hospitals, the bite of victims that progress only to a physician\u27s office, or those that receive no medical care at all. In Missouri alone, this study would infer about 1500 dog bites per year reaching only the general hospital. The number of dog and other animal bites across the country is unknown but may safely be assumed to be staggering in magnitude

Low validity of self-report in identifying recent mental health diagnosis among U.S. service members completing Pre-Deployment Health Assessment (PreDHA) and deployed to Afghanistan, 2007: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Since 1998, the U.S. Armed Forces has used the mandatory Pre-Deployment Health Assessment (PreDHA) screening questionnaire as a means of assessing the health and suitability of U.S. service members for deployment. Limited data exists to quantify the validity of the self-reported PreDHA. This study was conducted to assess the validity of self-reporting in PreDHA to identify deployed service members who have had a recent mental health disorder diagnosis.</p> <p>Methods</p> <p>A retrospective cohort study was conducted on 15,195 U.S. service members deployed in support of combat and reconstruction operations in Afghanistan. The Defense Medical Surveillance System (DMSS), the DoD's longitudinal medical surveillance database, was queried to identify cases among the cohort with a recent diagnosis of a pertinent mental health disorder and to obtain those subjects' responses to the PreDHA.</p> <p>Results</p> <p>Of the study cohort, 11,179 (73.6%) subjects had a PreDHA available within the DMSS at the time of analysis. A total of 615 subjects (4.0%) had one or more mental health disorder diagnoses during the pre-deployment period. Out the 615 subjects with diagnosed mental health disorders, 465 had a PreDHA. Among these, only 224, not quite half, answered in the affirmative to the PreDHA question: <it>"During the past year, have you sought counseling or care for your mental health?"</it></p> <p>Conclusion</p> <p>This study demonstrates that the self-reported PreDHA has low validity for identifying service members with diagnosed mental health disorders. The development of electronic decision-support systems which automatically screen electronic health records to identify high-risk service members may prove a valuable component of improved pre-deployment screening processes.</p

A simulation study for comparing testing statistics in response-adaptive randomization

<p>Abstract</p> <p>Background</p> <p>Response-adaptive randomizations are able to assign more patients in a comparative clinical trial to the tentatively better treatment. However, due to the adaptation in patient allocation, the samples to be compared are no longer independent. At large sample sizes, many asymptotic properties of test statistics derived for independent sample comparison are still applicable in adaptive randomization provided that the patient allocation ratio converges to an appropriate target asymptotically. However, the small sample properties of commonly used test statistics in response-adaptive randomization are not fully studied.</p> <p>Methods</p> <p>Simulations are systematically conducted to characterize the statistical properties of eight test statistics in six response-adaptive randomization methods at six allocation targets with sample sizes ranging from 20 to 200. Since adaptive randomization is usually not recommended for sample size less than 30, the present paper focuses on the case with a sample of 30 to give general recommendations with regard to test statistics for contingency tables in response-adaptive randomization at small sample sizes.</p> <p>Results</p> <p>Among all asymptotic test statistics, the Cook's correction to chi-square test (<it>T</it>_<it>MC</it>) is the best in attaining the nominal size of hypothesis test. The William's correction to log-likelihood ratio test (<it>T</it>_<it>ML</it>) gives slightly inflated type I error and higher power as compared with <it>T</it>_<it>MC</it>, but it is more robust against the unbalance in patient allocation. <it>T</it>_{<it>MC </it>}and <it>T</it>_{<it>ML </it>}are usually the two test statistics with the highest power in different simulation scenarios. When focusing on <it>T</it>_{<it>MC </it>}and <it>T</it>_<it>ML</it>, the generalized drop-the-loser urn (GDL) and sequential estimation-adjusted urn (SEU) have the best ability to attain the correct size of hypothesis test respectively. Among all sequential methods that can target different allocation ratios, GDL has the lowest variation and the highest overall power at all allocation ratios. The performance of different adaptive randomization methods and test statistics also depends on allocation targets. At the limiting allocation ratio of drop-the-loser (DL) and randomized play-the-winner (RPW) urn, DL outperforms all other methods including GDL. When comparing the power of test statistics in the same randomization method but at different allocation targets, the powers of log-likelihood-ratio, log-relative-risk, log-odds-ratio, Wald-type Z, and chi-square test statistics are maximized at their corresponding optimal allocation ratios for power. Except for the optimal allocation target for log-relative-risk, the other four optimal targets could assign more patients to the worse arm in some simulation scenarios. Another optimal allocation target, <it>R</it>_{<it>RSIHR</it>}, proposed by Rosenberger and Sriram (<it>Journal of Statistical Planning and Inference</it>, 1997) is aimed at minimizing the number of failures at fixed power using Wald-type Z test statistics. Among allocation ratios that always assign more patients to the better treatment, <it>R</it>_{<it>RSIHR </it>}usually has less variation in patient allocation, and the values of variation are consistent across all simulation scenarios. Additionally, the patient allocation at <it>R</it>_{<it>RSIHR </it>}is not too extreme. Therefore, <it>R</it>_{<it>RSIHR </it>}provides a good balance between assigning more patients to the better treatment and maintaining the overall power.</p> <p>Conclusion</p> <p>The Cook's correction to chi-square test and Williams' correction to log-likelihood-ratio test are generally recommended for hypothesis test in response-adaptive randomization, especially when sample sizes are small. The generalized drop-the-loser urn design is the recommended method for its good overall properties. Also recommended is the use of the <it>R</it>_{<it>RSIHR </it>}allocation target.</p

La “ideología de género” frente a los derechos sexuales y reproductivos. El escenario español

Se analiza el caso español como laboratorio europeo en el que se han ensayado las estrategias de movilización basadas en el discurso de la “ideología de género” contra los derechos sexuales y de las mujeres por parte de actores ultraconservadores, con especial atención a los actores católicos. Se presentan cuatro momentos: el discurso de la Iglesia Católica, como fuente originaria del lenguaje de este nuevo pánico moral; las reformas legales progresistas que detonan el ciclo de protesta; la contestación social de los grupos conservadores y la posterior reacción conservadora moderada desde la acción de gobierno

A randomized controlled pilot study of a brief web-based mindfulness training

Background: Mindfulness has been shown to be effective in treating various medical and mental problems. Especially its incorporation in cognitive-behavioural interventions has improved long-term outcomes of those treatments. It has also been shown, that brief mindfulness-based trainings are effective in reducing distress. There have been few web-based interventions incorporating mindfulness techniques in their manual and it remains unclear whether a brief web-based mindfulness intervention is feasible. Methods: Out of 50 adults (different distress levels; exclusion criteria: < 18 years, indication of psychotic or suicidal ideation in screening) who were recruited via e-mail and screened online, 49 were randomized into an immediate 2-weeks-treatment group (N = 28) or a waitlist-control group (N = 21), starting with a 2-week delay. Distress (BSI), perceived stress (PSQ), mindfulness (FMI), as well as mood and emotion regulation (PANAS/SEK-27) were measured at pre-, post- and 3-month follow-up (3MFU). Intention-to-treat analyses using MI for missing data and per-protocol analyses (≥ 50% attendance) were performed. Results: 26 participants of the treatment group completed post-measures. Most measures under ITT-analysis revealed no significant improvement for the treatment group, but trends with medium effect sizes for PSQ (d = 0.46) and PANASneg (d = 0.50) and a small, non-significant effect for FMI (d = 0.29). Per-protocol analyses for persons who participated over 50% of the time revealed significant treatment effects for PSQ (d = 0.72) and PANASneg (d = 0.77). Comparing higher distressed participants with lower distressed participants, highly distressed participants seemed to profit more of the training in terms of distress reduction (GSI, d = 0.85). Real change (RCI) occurred for PSQ in the treatment condition (OR = 9). Results also suggest that participants continued to benefit from the training at 3MFU. Conclusion: This study of a brief web-based mindfulness training indicates that mindfulness can be taught online and may improve distress, perceived stress and negative affect for regular users. Although there were no significant improvements, but trends, for most measures under ITT, feasibility of such a program was demonstrated and also that persons continued to use techniques of the training in daily life

Comparison of Monthly Ibandronate Versus Weekly Risedronate in Preference, Convenience, and Bone Turnover Markers in Korean Postmenopausal Osteoporotic Women

Patient preferences, convenience, and bone turnover markers were evaluated for the monthly ibandronate over the weekly risedronate regimen in Korean postmenopausal osteoporotic women. This was a 6-month, prospective, randomized, open-label, multicenter study with a two-period and two-sequence crossover treatment design. After a 30-day screening period, eligible participants with postmenopausal osteoporosis were randomized to receive either monthly oral ibandronate 150 mg for 3 months followed by weekly oral risedronate 35 mg for 12 weeks (sequence A) or the same regimen in reverse order (sequence B). Patient preference and convenience were evaluated by questionnaire. The changes in serum C-telopeptide after 3 months of treatment were analyzed. A total of 365 patients were enrolled in this study (sequence A 182, sequence B 183). Of patients expressing a preference (83.4%), 74.8% preferred the monthly ibandronate regimen over the weekly regimen (25.2%). More women stated that the monthly ibandronate regimen was more convenient (84.2%) than the weekly regimen (15.8%). There was no significant difference in the change in bone turnover marker between the two treatments. The two regimens were similarly tolerable. There were fewer adverse events in the monthly ibandronate group compared to the weekly risedronate group in terms of gastrointestinal side effects (nausea and abdominal distension). This study revealed a strong preference and convenience for monthly ibandronate over weekly risedronate in Korean postmenopausal osteoporotic women. There was no significant difference in change of bone turnover marker and safety profile between the two regimens

Microbial and Chemical Characterization of Underwater Fresh Water Springs in the Dead Sea

Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water’s chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea−Dead Sea water conduit