Proportional-Integral-Plus Control Strategy of an Intelligent Excavator

This article considers the application of Proportional-Integral-Plus (PIP) control to the Lancaster University Computerised Intelligent Excavator (LUCIE), which is being developed to dig foundation trenches on a building site. Previous work using LUCIE was based on the ubiquitous PI/PID control algorithm, tuned on-line, and implemented in a rather ad hoc manner. By contrast, the present research utilizes new hardware and advanced model-based control system design methods to improve the joint control and so provide smoother, more accurate movement of the excavator arm. In this article, a novel nonlinear simulation model of the system is developed for MATLAB/SIMULINK, allowing for straightforward refinement of the control algorithm and initial evaluation. The PIP controller is compared with a conventionally tuned PID algorithm, with the final designs implemented on-line for the control of dipper angle. The simulated responses and preliminary implementation results demonstrate the feasibility of the approach

Faith: How to be Partial while Respecting the Evidence

In her paper, “True Faith: Against Doxastic Partiality about Faith (in God and Religious Communities) and in Defense of Evidentialism,” Katherine Dormandy argues against the view that there is a partiality norm on faith. Dormandy establishes this by showing that partiality views can’t give the right responses to encounters with stubborn counter evidence. Either they (anti-epistemic-partiality views) recommend flouting the evidence altogether in order hold on to positive beliefs about the object of faith or they (epistemic-partiality views) lower the epistemic standards in objectionable ways to alleviate the epistemic pressure imposed by the counterevidence. However, one cannot have praiseworthy faith when one refuses to really grapple with the evidence against the goodness of the faith’s object. So, partiality norms, far from constituting what makes for great faith, importantly stand in its way. Thus, we should reject any partiality norms on faith. We argue that cases of praiseworthy faith involve dispositions to confront the object of faith when presented with stubborn counter evidence against their goodness. Recognizing this enables us to endorse a partiality norm while avoiding Dormandy’s worries. We argue that dispositions to confront the object of faith presuppose positive beliefs about it, thus vindicating partiality. We further argue that the confrontation makes an epistemic demand of the object of faith: produce high confidence in whether it is still worth having faith in, thus carving out a central role for evidentialist norms

A Comparison of Delivery Methods of Cognitive-Behavioral Therapy for Panic Disorder: An International Multicenter Trial

Cognitive-behavioral therapy (CBT) is the psychological treatment of choice for panic disorder (PD). However, given limited access to CBT, it must be delivered with maximal cost-effectiveness. Previous researchers have found that a brief computer-augmented CBT was as effective as extended therapist-delivered CBT. To test this finding, this study randomly allocated 186 patients with PD across 2 sites in Scotland and Australia to 12 sessions of therapist-delivered CBT (CBT12), 6 sessions of therapist-delivered (CBT6) or computer-augmented CBT (CBT6-CA), or a waitlist control. On a composite measure, at post-treatment, the outcome for CBT12 was statistically better than the outcome for CBT6. The outcome for CBT6-CA fell between CBT12 and CBT6, but could not be statistically distinguished from either treatment. The active treatments did not differ statistically at 6-month follow-up. The study provided some support for the use of computers as an innovative adjunctive-therapy tool and merits further investigation

Surgical treatment of prosthetic valve endocarditis

AbstractFrom 1975 through 1992, we reoperated on 146 patients for the treatment of prosthetic valve endocarditis. Prosthetic valve endocarditis was considered to be early (<1 year after operation) in 46 cases and active in 103 cases. The extent of the infection was prosthesis only in 66 patients, anulus in 46, and cardiac invasion in 34. Surgical techniques evolved in the direction of increasingly radical débridement of infected tissue and reconstruction with biologic materials. All patients were treated with prolonged postoperative antibiotic therapy. There were 19 (13%) in-hospital deaths. Univariate analyses demonstrated trends toward increasing risk for patients with active endocarditis and extension of infection beyond the prosthesis; however, the only variables with a significant (p < 0.05) association with increased in-hospital mortality confirmed with multivariate testing were impaired left ventricular function, preoperative heart block, coronary artery disease, and culture of organisms from the surgical specimen. During the study period, mortality decreased from 20% (1975 to 1984) to 10% (1984 to 1992). For hospital survivors the mean length of stay was 25 days. Follow-up (mean interval 62 months) documented a late survival of 82% at 5 postoperative years and 60% at 10 years. Older age was the only factor associated (p = 0.006) with late death. Nineteen patients needed at least one further operation; reoperation-free survival was 75% at 5 and 50% at 10 postoperative years. Fever in the immediate preoperative period was the only factor associated with decreased late reoperation-free survival (p = 0.032). Prosthetic valve endocarditis remains a serious complication of valve replacement, but the in-hospital mortality of reoperations for prosthetic valve endocarditis has declined. With extensive débridement of infected tissue and postoperative antibiotic therapy, the extent and activity of prosthetic valve endocarditis does not appear to have a major impact on late outcome, and the majority of patients with this complication survive for 10 years after the operation. (J THORAC CARDIOVASC SURG 1996;111:198-210

Characterisation of Bacteriophage-Encoded Depolymerases Selective for Key <i>Klebsiella pneumoniae</i> Capsular Exopolysaccharides.

Capsular polysaccharides enable clinically important clones of Klebsiella pneumoniae to cause severe systemic infections in susceptible hosts. Phage-encoded capsule depolymerases have the potential to provide an alternative treatment paradigm in patients when multiple drug resistance has eroded the efficacy of conventional antibiotic chemotherapy. An investigation of 164 K. pneumoniae from intensive care patients in Thailand revealed a large number of distinct K types in low abundance but four (K2, K51, K1, K10) with a frequency of at least 5%. To identify depolymerases with the capacity to degrade capsules associated with these common K-types, 62 lytic phage were isolated from Thai hospital sewage water using K1, K2 and K51 isolates as hosts; phage plaques, without exception, displayed halos indicative of the presence of capsule-degrading enzymes. Phage genomes ranged in size from 41-348 kb with between 50 and 535 predicted coding sequences (CDSs). Using a custom phage protein database we were successful in applying annotation to 30 - 70% (mean = 58%) of these CDSs. The largest genomes, of so-called jumbo phage, carried multiple tRNAs as well as CRISPR repeat and spacer sequences. One of the smaller phage genomes was found to contain a putative Cas type 1E gene, indicating a history of host DNA acquisition in these obligate lytic phage. Whole-genome sequencing (WGS) indicated that some phage displayed an extended host range due to the presence of multiple depolymerase genes; in total, 42 candidate depolymerase genes were identified with up to eight in a single genome. Seven distinct virions were selected for further investigation on the basis of host range, phage morphology and WGS. Candidate genes for K1, K2 and K51 depolymerases were expressed and purified as his6-tagged soluble protein and enzymatic activity demonstrated against K. pneumoniae capsular polysaccharides by gel electrophoresis and Anton-Paar rolling ball viscometry. Depolymerases completely removed the capsule in K-type-specific fashion from K. pneumoniae cells. We conclude that broad-host range phage carry multiple enzymes, each with the capacity to degrade a single K-type, and any future use of these enzymes as therapeutic agents will require enzyme cocktails for utility against a range of K. pneumoniae infections