Control primitives for robot systems

A methodology is developed for describing of hierarchical control of robot systems in a manner which is faithful to the underlying mechanics, structured enough to be used as an interpreted language, and sufficiently flexible to encompass a wide variety of systems. A consistent set of primitive operations which form the core of a robot system description and control language is presented. This language, motivated by the hierarchical organization of neuromuscular systems, is capable of describing a large class of robot systems under a variety of single-level and distributed control schemes

Psychometric validation of the Persian nine-item Internet Gaming Disorder Scale – Short Form: Does gender and hours spent online gaming affect the interpretations of item descriptions?

The nine-item Internet Gaming Disorder Scale – Short Form (IGDS-SF9) is brief and effective to evaluate Internet Gaming Disorder (IGD) severity. Although its scores show promising psychometric properties, less is known about whether different groups of gamers interpret the items similarly. This study aimed to verify the construct validity of the Persian IGDS-SF9 and examine the scores in relation to gender and hours spent online gaming among 2,363 Iranian adolescents. Methods Confirmatory factor analysis (CFA) and Rasch analysis were used to examine the construct validity of the IGDS-SF9. The effects of gender and time spent online gaming per week were investigated by multigroup CFA and Rasch differential item functioning (DIF). Results The unidimensionality of the IGDS-SF9 was supported in both CFA and Rasch. However, Item 4 (fail to control or cease gaming activities) displayed DIF (DIF contrast = 0.55) slightly over the recommended cutoff in Rasch but was invariant in multigroup CFA across gender. Items 4 (DIF contrast = −0.67) and 9 (jeopardize or lose an important thing because of gaming activity; DIF contrast = 0.61) displayed DIF in Rasch and were non-invariant in multigroup CFA across time spent online gaming. Conclusions Given the Persian IGDS-SF9 was unidimensional, it is concluded that the instrument can be used to assess IGD severity. However, users of the instrument are cautioned concerning the comparisons of the sum scores of the IGDS-SF9 across gender and across adolescents spending different amounts of time online gaming

Genomic analysis reveals hidden biodiversity within colugos, the sister group to primates

Colugos are among the most poorly studied mammals despite their centrality to resolving supraordinal primate relationships. Two described species of these gliding mammals are the sole living members of the order Dermoptera, distributed throughout Southeast Asia. We generated a draft genome sequence for a Sunda colugo and a Philippine colugo reference alignment, and used these to identify colugo-specific genetic changes that were enriched in sensory and musculoskeletal-related genes that likely underlie their nocturnal and gliding adaptations. Phylogenomic analysis and catalogs of rare genomic changes overwhelmingly support the contested hypothesis that colugos are the sister group to primates (Primatomorpha), to the exclusion of treeshrews. We captured ~140 kb of orthologous sequence data from colugo museum specimens sampled across their range and identified large genetic differences between many geographically isolated populations that may result in a >300% increase in the number of recognized colugo species. Our results identify conservation units to mitigate future losses of this enigmatic mammalian order.Victor C. Mason, Gang Li Patrick Minx, Jürgen Schmitz, Gennady Churakov, Liliya Doronina, Amanda D. Melin ... et al

Factors affecting the prevalence of strongly and weakly carcinogenic and lower-risk human papillomaviruses in anal specimens in a cohort of men who have sex with men (MSM)

Background: MSM are at higher risk for invasive anal cancer. Twelve human papillomaviruses (HPVs) cause cervical cancer in women (Group 1 high-risk HPVs (hrHPVs)) and 13 HPVs are probable/possible causes (Group 2 hrHPVs) of cervical malignancy. HPVs rarely associated with malignancy are classified as lower-risk HPVs (lrHPVs). Materials and Methods: Dacron-swab anal-cytology specimens were collected from and data complete for 97% (1262/1296) of Multicenter AIDS Cohort Study (MACS) men tested for HPVs using the Linear Array assay. Multivariate Poisson regression analyses estimated adjusted prevalence ratios for Group 1/2 hrHPVs and lrHPVs, controlling for the effects of age, race, ethnicity, sexual partnerships, smoking; HIV-infection characteristics, treatment, and immune status among HIV-infected men. Results: HIV-infected men showed 35-90% higher prevalence of Group 1/2 hrHPVs and lrHPVs than HIV-uninfected men, and higher prevalence of multi-Type, and multiple risk-group infections. CD4+ T-cell count was inversely associated with HPV Group 2 prevalence (p<0.0001). The number of receptive anal intercourse (RAI) partners reported in the 24 months preceding HPV testing predicted higher prevalence of Group 1/2 hrHPVs. Men reporting ≥30 lifetime male sex partners before their first MACS visit and men reporting ≥1 RAI partners during the 24 months before HPV testing showed 17-24% and 13-17% higher prevalence of lrHPVs (p-values ≤0.05). Men reporting smoking between MACS visit 1 and 24 months before HPV testing showed 1.2-fold higher prevalence of Group 2 hrHPVs (p = 0.03). Both complete adherence to CART (p = 0.02) and HIV load <50 copies/mL (p = 0.04) were protective for Group 1 hrHPVs among HIV-infected men. Conclusions: HIV-infected men more often show multi-type and multi-group HPV infections HIV-uninfected men. Long-term mutual monogamy and smoking cessation, generally, and CART-adherence that promotes (HIV) viremia control and prevents immunosuppression, specifically among HIV-infected MSM, are important prevention strategies for HPV infections that are relevant to anal cancer. © 2013 Wiley et al

Identifying Bayesian Optimal Experiments for Uncertain Biochemical Pathway Models

Pharmacodynamic (PD) models are mathematical models of cellular reaction networks that include drug mechanisms of action. These models are useful for studying predictive therapeutic outcomes of novel drug therapies in silico. However, PD models are known to possess significant uncertainty with respect to constituent parameter data, leading to uncertainty in the model predictions. Furthermore, experimental data to calibrate these models is often limited or unavailable for novel pathways. In this study, we present a Bayesian optimal experimental design approach for improving PD model prediction accuracy. We then apply our method using simulated experimental data to account for uncertainty in hypothetical laboratory measurements. This leads to a probabilistic prediction of drug performance and a quantitative measure of which prospective laboratory experiment will optimally reduce prediction uncertainty in the PD model. The methods proposed here provide a way forward for uncertainty quantification and guided experimental design for models of novel biological pathways

Pendulum Testing as a Means of Assessing the Crash Performance of Longitudinal Barrier with Minor Damage

Longitudinal barriers such as w-beam guardrails are subjected to a series of full-scale crash tests to determine their impact performance before being considered acceptable for use on the nation’s highways. Once longitudinal barriers are installed along a roadway, however, they often sustain minor damage in various ways. Since barriers are exclusively tested in an undamaged condition, there is very little known regarding the crash performance of barriers that have sustained minor damage. Transportation agencies responsible for deploying and maintaining these barrier systems need a better understanding of damaged barrier performance to make timely and cost-effective barrier maintenance decisions under the constraints of limited resources. This study is believed to be the first evaluation of the crash performance of strong post w-beam barrier that has sustained minor damage. A pendulum impact testing methodology was developed for the evaluation of two-post sections of strong post w-beam barrier. Pendulum tests were then conducted on barrier sections with five types of damage: (1) vertical tear, (2) horizontal tear, (3) splice damage, (4) twisted blockout, and (5) missing blockout. Based on these tests, vertical tears were found to be a significant threat to the structural adequacy of the barrier section with a high likelihood for rail rupture. A missing blockout at the splice location was found to result in marginal performance with one test resulting in a large rail tear at the splice. Mid-span horizontal tears and splice damage, with one of eight bolts lacking bearing capacity, were found to have a less significant threat on the structural adequacy of the barrier. Twisted blockout damage was found to have no effect on the structural crash performance of the strong post w-beam barrier

Droplet Crystallization in Water-in-Crude Oil Emulsions: Influence of Salinity and Droplet Size

Ice crystallization in confined spherical geometries is investigated experimentally at ambient pressure conditions. Water-in-crude (w/o) oil emulsions are formed by homogenization of an acidic North Sea crude oil with water or brine, at aqueous phase fractions ranging from 1 to 30 wt % and varying electrolyte contents. Ice-in-oil dispersions are formed from the emulsions by cooling, and they provide a justified analogue to gas hydrate formation in water-in-crude oil emulsions, due to analogous wettability conditions that govern agglomeration. Nuclear magnetic resonance (NMR) spectroscopy and digital video microscopy (DVM) imaging establish droplet size distributions (DSDs) and mean droplet diameters, and demonstrate emulsion stability with an absence of coalescence over extended time durations. Differential scanning calorimetry (DSC) establishes the crystallization temperature of the dispersed water droplets. It is demonstrated that the crystallization temperature decreases with a decreasing length scale of the dispersed water droplet phase, in accordance with theoretical knowledge.acceptedVersion© 2017. This is the authors’ accepted and refereed manuscript to the article. Locked until 21.5.2018 due to copyright restrictions