From visuomotor control to latent space planning for robot manipulation

Deep visuomotor control is emerging as an active research area for robot manipulation. Recent advances in learning sensory and motor systems in an end-to-end manner have achieved remarkable performance across a range of complex tasks. Nevertheless, a few limitations restrict visuomotor control from being more widely adopted as the de facto choice when facing a manipulation task on a real robotic platform. First, imitation learning-based visuomotor control approaches tend to suffer from the inability to recover from an out-of-distribution state caused by compounding errors. Second, the lack of versatility in task definition limits skill generalisability. Finally, the training data acquisition process and domain transfer are often impractical. In this thesis, individual solutions are proposed to address each of these issues. In the first part, we find policy uncertainty to be an effective indicator of potential failure cases, in which the robot is stuck in out-of-distribution states. On this basis, we introduce a novel uncertainty-based approach to detect potential failure cases and a recovery strategy based on action-conditioned uncertainty predictions. Then, we propose to employ visual dynamics approximation to our model architecture to capture the motion of the robot arm instead of the static scene background, making it possible to learn versatile skill primitives. In the second part, taking inspiration from the recent progress in latent space planning, we propose a gradient-based optimisation method operating within the latent space of a deep generative model for motion planning. Our approach bypasses the traditional computational challenges encountered by established planning algorithms, and has the capability to specify novel constraints easily and handle multiple constraints simultaneously. Moreover, the training data comes from simple random motor-babbling of kinematically feasible robot states. Our real-world experiments further illustrate that our latent space planning approach can handle both open and closed-loop planning in challenging environments such as heavily cluttered or dynamic scenes. This leads to the first, to our knowledge, closed-loop motion planning algorithm that can incorporate novel custom constraints, and lays the foundation for more complex manipulation tasks

Goal-Conditioned End-to-End Visuomotor Control for Versatile Skill Primitives

Visuomotor control (VMC) is an effective means of achieving basic manipulation tasks such as pushing or pick-and-place from raw images. Conditioning VMC on desired goal states is a promising way of achieving versatile skill primitives. However, common conditioning schemes either rely on task-specific fine tuning - e.g. using one-shot imitation learning (IL) - or on sampling approaches using a forward model of scene dynamics i.e. model-predictive control (MPC), leaving deployability and planning horizon severely limited. In this paper we propose a conditioning scheme which avoids these pitfalls by learning the controller and its conditioning in an end-to-end manner. Our model predicts complex action sequences based directly on a dynamic image representation of the robot motion and the distance to a given target observation. In contrast to related works, this enables our approach to efficiently perform complex manipulation tasks from raw image observations without predefined control primitives or test time demonstrations. We report significant improvements in task success over representative MPC and IL baselines. We also demonstrate our model's generalisation capabilities in challenging, unseen tasks featuring visual noise, cluttered scenes and unseen object geometries.Comment: revised manuscript with additional baselines and generalisation experiments; 11 pages, 8 figures, 7 table

Trogodišnji trend promjena tjelesne pripremljenosti i indeksa tjelesne mase u učenika u dobi od 12 do 16 godina s ekstremnim indeksima tjelesne mase

The aim of this study was to investigate a three-year development in BMI and physical fitness of schoolchildren aged 12-16 years with extreme weight status. Taiwan Physical Fitness Test Battery, assessing aerobic fitness (1600-meter walk/run test), power (standing long jump), muscular endurance (sit-up), and flexibility (sit-and-reach) in 16,945 boys, was implemented in September from the year 2006 till 2008. Overweight and underweight were defined by the baseline BMI data values that fall within the highest and lowest 5% of their age population, whereas the BMI data values that fall within one standard deviation of the mean was considered “normal” in this study. The results showed that BMI of schoolchildren in 2006 was ~2–3 kg/m2 above the national average reported in 1993. All physical fitness components in the overweight group were substantially poorer than those in the normal group. Yet, these fitness parameters were improved over the three years in all groups. BMI in the underweight group increased at a faster rate than that in the normal and overweight groups. No difference was found in the jumping distance between the underweight and normal groups. Aerobic fitness in the underweight group was superior but flexibility and muscular endurance were slightly lower than those in the normal group. BMI of Taiwan schoolchildren increased substantially from 1993 to 2006 but leveled off from 2006 to 2008. Underweight schoolchildren during the growing period should not a priori be considered as physically weaker or unfit individuals.Cilj je ovog istraživanja bio ustanoviti trogodišnji trend razvoja indeksa tjelesne mase (ITM) i tjelesne pripremljenosti u učenika, u dobi između 12 i 16 godina, s ekstremnim vrijednostima tjelesne težine. Tajvanski sklop testova za tjelesnu pripremljenosti (Taiwan Physical Fitness Test Battery), koja uključuje procjenu aerobne pripremljenosti (test hodanja/ trčanja na 1600 metara), eksplozivne snage (skok u dalj s mjesta), mišićne izdržljivosti (podizanje trupa iz ležanja na leđima) i fleksibilnosti (sjed-i-dohvat), primijenjen je od 2006 do 2008 godine u mjesecu rujnu na uzorku od 16.945 dječaka. Preteški (overweight) i prelagani (underweight) ispitanici bili su definirani prema inicijalnoj vrijednosti ITM-a za dobnu skupinu populacije ispitanika kao oni koji se ubrajaju među 5% s najvišim odnosno najnižim vrijednostima ITM. Ispitanici koji su se nalazili unutar jedne standardne devijacije smatrali su se „normalnima“. Rezultati su pokazali da je ITM tajvanskih učenika u 2006. godini bio za ~2–3kg/m2 veći od nacionalnog prosjeka objavljenog 1993. godine. Sve varijable tjelesne pripremljenosti u grupi prekomjerno teških bile su značajno lošije u odnosu na rezultate koje su postigli ispitanici u normalnoj grupi. Ipak, rezultati su se u svim mjerenim varijablama u svim grupama poboljšali tijekom 3 godine mjerenja. ITM je u grupi nedovoljno teških porastao većom brzinom nego u grupama normalnih i prekomjerno teških učenika. Nije utvrđena značajna razlika u rezultatima skoka u dalj s mjesta između grupa nedovoljno teških i normalnih ispitanika. Nedovoljno teški ispitanici imali su najbolje rezultate u aerobnoj izdržljivosti u odnosu na ostale grupe, dok su u fleksibilnosti i mišićnoj izdržljivosti bili nešto slabiji nego ispitanici u normalnoj grupi. ITM je u tajvanske djece značajno porastao u razdoblju od 1993. do 2006. godine, ali je i stagnirao u razdoblju od 2006. do 2008. godine. Nedovoljno teška djeca ne bi se smjela a priori smatrati fizički slabijom ili nespremnom tijekom perioda odrastanja

Adipose-derived mesenchymal stem cells markedly attenuate brain infarct size and improve neurological function in rats

<p>Abstract</p> <p>Background</p> <p>The therapeutic effect of adipose-derived mesenchymal stem cells (ADMSCs) on brain infarction area (BIA) and neurological status in a rat model of acute ischemic stroke (IS) was investigated.</p> <p>Methods</p> <p>Adult male Sprague-Dawley (SD) rats (n = 30) were divided into IS plus intra-venous 1 mL saline (at 0, 12 and 24 h after IS induction) (control group) and IS plus intra-venous ADMSCs (2.0 × 10⁶) (treated interval as controls) (treatment group) after occlusion of distal left internal carotid artery. The rats were sacrificed and brain tissues were harvested on day 21 after the procedure.</p> <p>Results</p> <p>The results showed that BIA was larger in control group than in treatment group (p < 0.001). The sensorimotor functional test (Corner test) identified a higher frequency of turning movement to left in control group than in treatment group (p < 0.05). mRNA expressions of Bax, caspase 3, interleukin (IL)-18, toll-like receptor-4 and plasminogen activator inhibitor-1 were higher, whereas Bcl-2 and IL-8/Gro were lower in control group than in treatment group (all p < 0.05). Western blot demonstrated a lower CXCR4 and stromal-cell derived factor-1 (SDF-1) in control group than in treatment group (all p < 0.01). Immunohistofluorescent staining showed lower expressions of CXCR4, SDF-1, von Willebran factor and doublecortin, whereas the number of apoptotic nuclei on TUNEL assay was higher in control group than in treatment group (all p < 0.001). Immunohistochemical staining showed that cellular proliferation and number of small vessels were lower but glial fibrillary acid protein was higher in control group than in treatment group (all p < 0.01).</p> <p>Conclusions</p> <p>ADMSC therapy significantly limited BIA and improved sensorimotor dysfunction after acute IS.</p

The StarCraft Multi-Agent Challenge

In the last few years, deep multi-agent reinforcement learning (RL) has become a highly active area of research. A particularly challenging class of problems in this area is partially observable, cooperative, multi-agent learning, in which teams of agents must learn to coordinate their behaviour while conditioning only on their private observations. This is an attractive research area since such problems are relevant to a large number of real-world systems and are also more amenable to evaluation than general-sum problems. Standardised environments such as the ALE and MuJoCo have allowed single-agent RL to move beyond toy domains, such as grid worlds. However, there is no comparable benchmark for cooperative multi-agent RL. As a result, most papers in this field use one-off toy problems, making it difficult to measure real progress. In this paper, we propose the StarCraft Multi-Agent Challenge (SMAC) as a benchmark problem to fill this gap. SMAC is based on the popular real-time strategy game StarCraft II and focuses on micromanagement challenges where each unit is controlled by an independent agent that must act based on local observations. We offer a diverse set of challenge maps and recommendations for best practices in benchmarking and evaluations. We also open-source a deep multi-agent RL learning framework including state-of-the-art algorithms. We believe that SMAC can provide a standard benchmark environment for years to come. Videos of our best agents for several SMAC scenarios are available at: https://youtu.be/VZ7zmQ_obZ0

Targeting cancer addiction for SALL4 by shifting its transcriptome with a pharmacologic peptide

Sal-like 4 (SALL4) is a nuclear factor central to the maintenance of stem cell pluripotency and is a key component in hepatocellular carcinoma, a malignancy with no effective treatment. In cancer cells, SALL4 associates with nucleosome remodeling deacetylase (NuRD) to silence tumor-suppressor genes, such as PTEN. Here, we determined the crystal structure of an amino-terminal peptide of SALL4(1-12) complexed to RBBp4, the chaperone subunit of NuRD, at 2.7 Å, and subsequent design of a potent therapeutic SALL4 peptide (FFW) capable of antagonizing the SALL4-NURD interaction using systematic truncation and amino acid substitution studies. FFW peptide disruption of the SALL4-NuRD complex resulted in unidirectional up-regulation of transcripts, turning SALL4 from a dual transcription repressor-activator mode to singular transcription activator mode. We demonstrate that FFW has a target affinity of 23 nM, and displays significant antitumor effects, inhibiting tumor growth by 85% in xenograft mouse models. Using transcriptome and survival analysis, we discovered that the peptide inhibits the transcription-repressor function of SALL4 and causes massive up-regulation of transcripts that are beneficial to patient survival. This study supports the SALL4-NuRD complex as a drug target and FFW as a viable drug candidate, showcasing an effective strategy to accurately target oncogenes previously considered undruggable

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities

A Twenty-First Century Assessment of Values Across the Global

This article provides current Schwartz Values Survey (SVS) data from samples of business managers and professionals across 50 societies that are culturally and socioeconomically diverse. We report the society scores for SVS values dimensions for both individual- and societallevel analyses. At the individual-level, we report on the ten circumplex values sub-dimensions and two sets of values dimensions (collectivism and individualism; openness to change, conservation, self-enhancement, and self- transcendence). At the societal-level, we report on the values dimensions of embeddedness, hierarchy, mastery, affective autonomy, intellectual autonomy, egalitarianism, and harmony. For each society, we report the Cronbach’s a statistics for each values dimension scale to assess their internal consistency (reliability) as well as report interrater agreement (IRA) analyses to assess the acceptability of using aggregated individual level values scores to represent country values. We also examined whether societal development level is related to systematic variation in the measurement and importance of values. Thus, the contributions of our evaluation of the SVS values dimensions are two-fold. First, we identify the SVS dimensions that have cross-culturally internally reliable structures and withinsociety agreement for business professionals. Second, we report the society cultural values scores developed from the twenty-first century data that can be used as macro-level predictors in multilevel and single-level international business research