Accelerating Online Reinforcement Learning via Supervisory Safety Systems

Deep reinforcement learning (DRL) is a promising method to learn control policies for robots only from demonstration and experience. To cover the whole dynamic behaviour of the robot, the DRL training is an active exploration process typically derived in simulation environments. Although this simulation training is cheap and fast, applying DRL algorithms to real-world settings is difficult. If agents are trained until they perform safely in simulation, transferring them to physical systems is difficult due to the sim-to-real gap caused by the difference between the simulation dynamics and the physical robot. In this paper, we present a method of online training a DRL agent to drive autonomously on a physical vehicle by using a model-based safety supervisor. Our solution uses a supervisory system to check if the action selected by the agent is safe or unsafe and ensure that a safe action is always implemented on the vehicle. With this, we can bypass the sim-to-real problem while training the DRL algorithm safely, quickly, and efficiently. We provide a variety of real-world experiments where we train online a small-scale, physical vehicle to drive autonomously with no prior simulation training. The evaluation results show that our method trains agents with improved sample efficiency while never crashing, and the trained agents demonstrate better driving performance than those trained in simulation.Comment: 7 Pages, 10 Figures, 1 Table. Submitted to 2023 IEEE International Conference on Robotics and Automation (ICRA 2023

Secondary Science and Mathematics Teachers’ Environmental Issues Engagement through SocioScientific Reasoning

Among the many responsibilities of K-12 educators is to promote the development of environmental literacy among their students. Contentious environmental issues are often considered socioscientific issues (SSI; e.g., climate change) in that they are rooted in science, but a myriad of non-scientific (e.g., cultural, political, economic, etc.) factors must be addressed if those issues are to be successfully resolved. Teachers often report being ill-equipped to address these non-scientific factors, which may be due to struggles with employing socioscientific reasoning (SSR). SSR includes understanding the complexity of SSI, engaging in perspective-taking and ongoing inquiry about SSI, employing skepticism when dealing with potentially biased information concerning SSI, and recognizing the affordances of science and non-science considerations in resolving those issues. In this study, mathematics and science teachers who engaged in an SSI-oriented professional development demonstrated a range of sophistication across the dimensions of SSR, with science teachers tending to exhibit more sophistication in their SSR than mathematics teachers. Herein, we share and discuss the results of the study, including the prompts and scoring rubrics with exemplars, which can be used to prepare teachers to teach about contentious SSI and enable them to more effectively instruct and evaluate their students when doing so

Billy Budd

De cada obra s'ha digitalitzat un programa sencer. De la resta s'han digitalitzat les parts que són diferents.Empresa: Juan A. PamiasÒpera en dos actes de Benjamin Britten amb llibret de E. M. Forster i Eric Crozier basada en la novel·la de Herman Melvill

The relation of C - reactive protein to chronic kidney disease in African Americans: the Jackson Heart Study

<p>Abstract</p> <p>Background</p> <p>African Americans have an increased incidence and worse prognosis with chronic kidney disease (CKD - estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m²) than their counterparts of European-descent. Inflammation has been related to renal disease in non-Hispanic whites, but there are limited data on the role of inflammation in renal dysfunction in African Americans in the community.</p> <p>Methods</p> <p>We examined the cross-sectional relation of log transformed C-reactive protein (CRP) to renal function (eGFR by Modification of Diet and Renal Disease equation) in African American participants of the community-based Jackson Heart Study's first examination (2000 to 2004). We conducted multivariable linear regression relating CRP to eGFR adjusting for age, sex, body mass index, systolic and diastolic blood pressure, diabetes, total/HDL cholesterol, triglycerides, smoking, antihypertensive therapy, lipid lowering therapy, hormone replacement therapy, and prevalent cardiovascular disease events. In a secondary analysis we assessed the association of CRP with albuminuria (defined as albumin-to-creatinine ratio > 30 mg/g).</p> <p>Results</p> <p>Participants (n = 4320, 63.2% women) had a mean age ± SD of 54.0 ± 12.8 years. The prevalence of CKD was 5.2% (n = 228 cases). In multivariable regression, CRP concentrations were higher in those with CKD compared to those without CKD (mean CRP 3.2 ± 1.1 mg/L vs. 2.4 ± 1.0 mg/L, respectively p < 0.0001). CRP was significantly associated with albuminuria in sex and age adjusted model however not in the multivariable adjusted model (p > 0.05).</p> <p>Conclusion</p> <p>CRP was associated with CKD however not albuminuria in multivariable-adjusted analyses. The study of inflammation in the progression of renal disease in African Americans merits further investigation.</p

Functional Enhancers at the Gene-Poor 8q24 Cancer-Linked Locus

Multiple discrete regions at 8q24 were recently shown to contain alleles that predispose to many cancers including prostate, breast, and colon. These regions are far from any annotated gene and their biological activities have been unknown. Here we profiled a 5-megabase chromatin segment encompassing all the risk regions for RNA expression, histone modifications, and locations occupied by RNA polymerase II and androgen receptor (AR). This led to the identification of several transcriptional enhancers, which were verified using reporter assays. Two enhancers in one risk region were occupied by AR and responded to androgen treatment; one contained a single nucleotide polymorphism (rs11986220) that resides within a FoxA1 binding site, with the prostate cancer risk allele facilitating both stronger FoxA1 binding and stronger androgen responsiveness. The study reported here exemplifies an approach that may be applied to any risk-associated allele in non-protein coding regions as it emerges from genome-wide association studies to better understand the genetic predisposition of complex diseases

13kW Advanced Electric Propulsion Flight System Development and Qualification

The next phase of robotic and human deep space exploration missions is enhanced by high performance, high power solar electric propulsion systems for large-scale science missions and cargo transportation. Aerojet Rocketdynes Advanced Electric Propulsion System (AEPS) program is completing development, qualification and delivery of five flight 13.3kW EP systems to NASA. The flight AEPS includes a magnetically-shielded, long-life Hall thruster, power processing unit (PPU), xenon flow controller (XFC), and intrasystem harnesses. The Hall thruster, originally developed and demonstrated by NASAs Glenn Research Center and the Jet Propulsion Laboratory, operates at input powers up to 12.5kW while providing a specific impulse over 2600s at an input voltage of 600V. The power processor is designed to accommodate an input voltage range of 95 to 140V, consistent with operation beyond the orbit of Mars. The integrated system is continuously throttleable between 3 and 13.3kW. The program has completed the system requirement review; the system, thruster, PPU and XFC preliminary design reviews; development of engineering models, and initial system integration testing. This paper will present the high power AEPS capabilities, overall program and design status and the latest test results for the 13.3kW flight system development and qualification program

Beauty in Disability: An Aesthetics for Dance and for Life

To what extent does dance contribute to an ideal of beauty that can enrich human quality of life? To what extent are standards of beauty predicated on an ideal human body that has no disability? In this chapter, we show how conceptions of proportionality, perfection, and ethereality from the Ancient Greeks through the 19th century can still be seen today in some kinds of dance, particularly in ballet. Disability studies and disability-inclusive dance companies, however, have started to change this. The disabled person can be beautiful, we will show, in dance and in life, under a disability aesthetics that follows Edmund Burke (1730-1797) and that suggests an alternative standard of beauty, which we call “beauty-in-experience,” where beauty is perceived in the qualitative experience of abled and disabled dancers moving together in dance.https://ecommons.udayton.edu/books/1023/thumbnail.jp

An Upgraded, Highly Saturated Linkage Map of Japanese Plum (Prunus salicina Lindl.), and Identification of a New Major Locus Controlling the Flavan-3-ol Composition in Fruits

Japanese plum fruits are rich in phenolic compounds, such as anthocyanins and flavan-3-ols, whose contents vary significantly among cultivars. Catechin (C) and epicatechin (EC) are flavan-3-ol monomers described in the fruits of this species and are associated with bitterness, astringency, antioxidant capacity, and susceptibility to enzymatic mesocarp browning. In this study, we aimed to identify quantitative trait loci (QTL) associated with the content of flavan-3-ol in Japanese plum fruits. We evaluated the content of C and EC in the mesocarp and exocarp of samples from 79 and 64 seedlings of an F1 progeny () in the first and second seasons, respectively. We also constructed improved versions of linkage maps from ‘98–99’ and ‘Angeleno,’ presently called single-nucleotide polymorphisms (SNPs) after mapping the already available GBS reads to Prunus salicina Lindl. cv. ‘Sanyueli’ v2.0 reference genome. These data allowed for describing a cluster of QTLs in the cultivar, ‘Angeleno,’ associated with the flavan-3-ol composition of mesocarp and exocarp, which explain up to 100% of the C/EC ratio. Additionally, we developed a C/EC metabolic marker, which was mapped between the markers with the highest log of odds (LOD) scores detected by the QTL analysis. The C/EC locus was located in the LG1, at an interval spanning 0.70 cM at 108.30–108.90 cM. Our results suggest the presence of a novel major gene controlling the preferential synthesis of C or EC in the Japanese plum fruits. This study is a significant advance in understanding the regulation of synthesizing compounds associated with fruit quality, postharvest, and human health promotion.This study has been funded by the National Agency of Research and Development (ANID)/the Scholarship Program/BECAS DE DOCTORADO NACIONAL/2020 – 21200330; Fondecyt Regular No. 1191446; Fondecyt Iniciación No. 11150662; Fondecyt Regular No. 1200718; FONDEF Project IT17I0069 Sweet Pekeetah: “un modelo tecnológico- comercial para una nueva variedad chilena de fruta”. JS was supported by the Ministry of Science and Innovation of Spain through the Juan de la Cierva incorporation contract (IJC2018-036623-I

Adipocyte-specific protein tyrosine phosphatase 1B deletion increases lipogenesis, adipocyte cell size and is a minor regulator of glucose homeostasis

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