This paper presents a case study of learning to select behavioral primitives and generate subgoals from observation and practice. Our approach uses local features to generalize across tasks and ...global features to learn from practice. We demonstrate this approach applied to the marble maze task. Our robot uses local features to initially learn primitive selection and subgoal generation policies from observing a teacher maneuver a marble through a maze. The robot then uses this information as it tries to traverse another maze, and refines the information during learning from practice
Background. Helicobacter pylori eradication has become the standard treatment for peptic ulcer disease. H. pylori–eradicating triple therapy with omeprazole plus two antibiotics has been used until ...recently; however, the efficacy of pantoprazole and antibiotics for H. pylori eradication has not been researched thoroughly until now. The aim of this randomized clinical trial was to verify the efficacy of triple oral therapy comparing the effects of pantoprazole using two different doses versus omeprazole twice daily in H. pylori eradication, in ulcer healing and relapses, and in gastritis improvement.
Materials and Methods. We enrolled 243 patients with H. pylori–positive duodenal ulcer and randomized them into three treatment groups: 84 patients (group Ome40) were assigned to receive omeprazole, 20 mg twice daily, plus amoxicillin, 1 gm twice daily, and clarithromycin, 500 mg twice daily for 10 days; 79 patients (group Pan40) were treated with pantoprazole, 40 mg daily, plus amoxicillin and clarithromycin at the same doses as those of group Ome40; and 80 patients (group Pan80) were treated with pantoprazole, 40 mg twice daily, plus amoxicillin and clarithromycin at the same doses as those of group Ome40.
Results. Ulcer healing was observed in 81 of 84 patients (96.4%) in group Ome40; in 66 of 79 patients (83.5%) in group Pan40; and in 77 of 80 patients (96.2%) in group Pan80. H. pylori was eradicated in 79 of 84 patients (94%) in group Ome40; in 63 of 79 patients (79.7%) in group Pan40; and in 75 of 80 patients (93.7%) in group Pan80.
Conclusions. We found that 10‐day triple therapy with amoxicillin, clarithromycin, and either pantoprazole, 80 mg daily, or omeprazole, 40 mg daily, is highly effective in ulcer healing and is very well tolerated, achieving the 90% cure recommended for an ideal first‐line anti–H. pylori positive duodenal ulcer treatment regimen.
Cutaneous hypersensitivity reaction can be induced in chickens by skin painting with oxazolone, 33 mg/Kg of body weight (KBW). The B cell contribution to the generation of the cutaneous reaction has ...been a matter of controversy. In an attempt to characterize this reaction we placed special interest on the possibility that the nature of this reaction could be Arthus type hypersensitivity. From the kinetics study on the cutaneous hypersensitivity after challenge with oxazolonated egg-albumin (EA-OX) it was excluded that the nature of this reaction could be delayed type hypersensitivity. Immune sera transfer experiments demonstrated that the cutaneous reaction was antibody dependent. Serum anti-oxazolone antibody titers in sensitized chickens were assayed by antiglobulin haemagglutination, using oxazolone coupled sheep erythrocytes (OX-SRBC). High titres of IgG were found in contact sensitized chickens. Furthermore this cutaneous reaction was characterized by neutrophils, inflammatory edema, rare thrombotic occlusion of small venules and on absence of monocytes. The utilization of complete Freunds' adjuvant (CFA) given at sensitization demonstrated that CFA enhanced oxazolone antibodies in the sera of immunized chickens without a correlated increase in the intensity of the cutaneous reaction to EA-OX. Animals sensitized to oxazolone (33 mg/KBW) without CFA and challenged intravenously seven days later with oxazolone coupled to autologous chicken red blood cells (OX-CRBC) died from anaphylactic shock; instead animals with the same treatment but with CFA given at sensitization did not die from anaphylactic shock. Taken collectively it was concluded that the cutaneous reaction to oxazolone in the chicken can be categorized as Arthus hypersensitivity. The relationship between cutaneous Arthus reaction and anaphylactic shock in chickens sensitized to oxazolone is discussed.
Learning without any prior knowledge in environments that contain large or continuous state spaces is a daunting task. For robots that operate in the real world, learning must occur in a reasonable ...amount of time. Providing a robot with domain knowledge and also with the ability to learn from watching other can greatly increase its learning rate. This research seeks to explore learning algorithms that can learn quickly and make the most use of information obtained from observing others. Domain knowledge is encoded in the form of primitives, small parts of a task that are executed many times while a task is being performed. This thesis explores and presents difficulties involved in getting robots to learn and adapt to environments that humans operate in. Virtual and real-world environments of air hockey and the marble maze game have been created as test-beds for this research. A humanoid robot has been programmed to operate in the air hockey environment and a Labyrinth game has been equipped with motors and sensors to allow it to be controlled by a computer. A “Learning from Observation Using Primitives” framework has been created. This framework provides the means to observe primitives as they are performed by others. This information is then used by the robot in a three-level process as it performs in the environment. Our initial research has shown that using only observed information leads to varying degrees of success. Therefore, the robot must have the ability to learn from practice while operating in the environment. Our framework provides a means for the robot to observe and evaluate its own actions as it performs in the environment. This information can then be used to increase the performance of selecting and performing the primitives.
Compliant control of a hydraulic humanoid joint Bentivegna, D.C.; Atkeson, C.G.; Jung-Yup Kim
2007 7th IEEE-RAS International Conference on Humanoid Robots,
2007-Nov.
Conference Proceeding
Open access
This paper presents an analysis of a hydraulic joint on a humanoid robot. Various controllers have been designed that allow the limb to have a range of characteristics such as being stiff or ...compliant.
This paper describes humanoid robot learning from observation and game playing using information provided by a real-time PC-based vision system. To cope with extremely fast motions that arise in the ...environment, a visual system capable of perceiving the motion of several objects at 60 fields per second was developed. We have designed a suitable error recovery scheme for our vision system to ensure successful game playing over longer periods of time. To increase the learning rate of the robot it is given domain knowledge in the form of primitives. The robot learns how to perform primitives from data collected while observing a human. The robot control system and primitive use strategy are also explained.
Lymphocytic infiltration at diagnosis is prognostic in EOC, however, the impact of NACT on tumour infiltrating lymphocytes (TILs) or PD-L1 expression remains poorly described.
Patients with EOC and ...sequential samples (pre-NACT, post-NACT or relapse) were retrospectively identified. TILs were evaluated on whole sections; stromal TILs (sTILs) scored as percentage of stromal area with high sTILs defined as ≥50%; intra-epithelial TILs (ieTILs) scored semi-quantitatively (0–3) with high ieTILs ≥2. A smaller number were available for PD-L1 evaluation, cut-off for positivity was ≥5% staining.
sTILs were detected in all tumours at diagnosis (range 2–90%, median 20%), with 22% (25/113) showing high sTILs. Among evaluable paired pre/post-NACT samples (N=83), an overall increase in median sTILs from 20% to 30% was seen following NACT (P=0.0005); individually the impact of NACT varied with sTILs increasing in 51% (42/83), decreasing in 25%, and stable in 24%. Post-NACT sTILs were predictive of platinum-free interval (PFI), patients with PFI ≥6 months had significantly higher post-NACT sTILs (sTILs 28% versus 18% for PFI <6 months,P=0.026); pre-NACT sTILS were not predictive. At diagnosis, 23% showed high ieTILs, and following NACT 33% showed increasing ieTILs. Proportion of tumours with PD-L1-positive immune cells was 30% (15/50) pre-NACT and 53% (27/51) post-NACT (P=0.026). Among paired tumours, 63% of PD-L1-negative tumours became positive after NACT, furthermore cisplatin induced PD-L1 expression in PD-L1-negative EOC cell lines. On multivariate analysis, high sTILs both pre- and post-NACT were independent prognostic factors for progression-free survival (PFS) (HR 0.49,P=0.02 and HR 0.60,P=0.05, respectively). No prognostic impact of ieTILs or PD-L1 expression was detected.
In EOC, sTILs levels are prognostic at diagnosis and remain prognostic after NACT. TILs and PD-L1 expression increase following NACT. Evaluation of immune parameters in the post-NACT tumour may help select patients for immunotherapy trials.
This paper proposes a gain switching algorithm for joint position control of a hydraulic humanoid robot. Accurate position control of the lower body is one of the basic requirements for robust ...balance and walking control. Joint position control is more difficult for hydraulic robots than it is for electric robots because of a slower actuator time constant and the back-drivability of hydraulic joints. Backdrivability causes external forces and torques to have a large effect on the position of the joints. External ground reaction forces therefore prevent a simple proportional-derivative (PD) controller from realizing accurate joint position control. We propose a state feedback controller for joint position control of the lower body, define three modes of state feedback gains, and switch the gains according to the zero moment point (ZMP) using linear interpolation. The performance of the algorithm is evaluated with a dynamic simulation of a hydraulic humanoid.
PDF
