Short Learning Research Articles

1269: Ease of Deflation and Shorter Learning Curve in Patients Undergoing Implantation of Inflatable Penile Prosthesis: Early Experience Using the New American Medical Systems 700 CX with Tactile PUMP

1269: Ease of Deflation and Shorter Learning Curve in Patients Undergoing Implantation of Inflatable Penile Prosthesis: Early Experience Using the New American Medical Systems 700 CX with Tactile PUMP

On Improvement of Classification Accuracy for Stochastic Discrimination

Stochastic discrimination (SD) depends on a discriminant function for classification. An improved SD is introduced to reduce the error rate of the standard SD in the context of a two-class classification problem. The learning procedure of the improved SD consists of two stages. Initially a standard SD, but with shorter learning period is carried out to identify an important space where all the misclassified samples are located. Then the standard SD is modified by 1) restricting sampling in the important space, and 2) introducing a new discriminant function for samples in the important space. It is shown by mathematical derivation that the new discriminant function has the same mean, but with a smaller variance than that of the standard SD for samples in the important space. It is also analyzed that the smaller the variance of the discriminant function, the lower the error rate of the classifier. Consequently, the proposed improved SD improves standard SD by its capability of achieving higher classification accuracy. Illustrative examples are provided to demonstrate the effectiveness of the proposed improved SD.

Beyond the walls of the lunatic asylum: Christopher Hope’s early fiction

This article examines an under-explored aspect of Christopher Hope’s early fiction: its capacity to suggest the potential for imaginative and psychological freedom through its comic, carnivalesque qualities. Hope produced various novels and stories set in South Africa during the 1950s and 1960s, including A Separate Development (1981), Black Swan (1987) and the short story collection Learning to Fly (1990). It is argued that Hope’s vision in these works tends to be perceived as essentially satirical, ultimately limited by bleakness and pessimism; while the carnivalesque, potentially liberatory aspects of his writing tend to be overlooked. By utilising comic and carnivalesque features Hope’s work indeed offers creative, liberated ways of apprehending reality. Mikhail Bakhtin’s discussion of the ability of the carnivalesque to open up new ways of seeing, through the “nonofficial” versions of reality that it proffers, is particularly relevant in this regard. It is argued that this latter aspect of Hope’s work is especially significant, bearing in mind the sense of constraint and confinement that seemed to dominate much of South African fiction during the apartheid era and that still remains a key concern in many postapartheid novels.

Laparoscopy for Malignancy: The Role of Handoscopy

In the last decade, laparoscopic surgery has revolutionized the practice of surgery to a great extent. Experienced laparoscopic surgeons have acquired proficiency for advanced procedures; however, complex laparoscopic procedures are still unpopular due to the high technical demand. Hand-assisted laparoscopic surgery or handoscopy has been developed as an adjunct to conventional laparoscopy, but its role for the management of malignancy is controversial. This technique allows the surgeon to insert a hand into the body cavities via a glovesize skin incision, while maintaining the pneumoperitoneum. The hand insertion allows tactile sensation, assists in atraumatic retraction and blunt dissection, and helps safeguard vascular control. The hand-assisted device also provides wound protection and allows intact specimen retrieval. Its applications in various oncologic procedures have demonstrated feasibility and even better recovery in some selected procedures compared with laparotomy. It may also help to reduce conversions. Handoscopic procedures allow a shorter learning curve and operative time, thereby attracting more surgeons to attempt advanced laparoscopic operations. Thus, in a selected group of complicated procedures, handoscopy provides an alternative to laparoscopy and the traditional open approach in the management of malignancy.

Cerebral cholinergic neurotransmission in protein and tryptophan-restricted adult rats.

To evaluate the effects of protein and tryptophan restriction on cholinergic neurotransmission in terms of choline acetyltransferase (CAT) activity and its expression as well as muscarinic receptors number at cerebral cortex and hippocampus, Wistar rats were raised on a chronically protein and tryptophan restricted diets with 8% protein based on either Purina chow or corn. There was a significant decrease in both body and cerebral weight in the restricted animals compared with the control group fed with 23% protein diet. In cerebral cortex CAT activity and its expression were significantly increased in corn fed (C) versus protein restricted (HP) and control (T) animals, without no significant changes in muscarinic receptors number. On the other hand, hippocampus CAT activity and its expression were significantly lesser and muscarinic receptors significantly increased in C group and CAT activity in HP group was significantly increased without significant changes in muscarinic receptors related to T group. These results indicate that a reduction in 5-HT disponibility on brain induced by tryptophan restricted diet during development affects clearly the cholinergic system modifying probably the short term memory and learning.

Multimedia textbook for virtual education environment

This paper discusses a proposed multimedia textbook to be implemented in a virtual education environment (VEE) at the Multimedia University in Cyberjaya, Malaysia. The aim of the multimedia textbook, which is targeted at engineering courses, is to bring out a student's creative abilities and to minimise basic study and learning time so that more subjects can be provided to prepare students for future interdisciplinary R&D and industrial work. The multimedia textbook is designed both for students on-campus and for those scattered locally and internationally. Shorter learning times have already been confirmed using an experimental multimedia textbook having a limited set of interfaces (see, hear, click). The remaining interfaces will be implemented next and AI software included to enable a students learning behaviour to be monitored and to customise learning materials according to the student's level of understanding.

The Problem of Sample Contamination in a Fluvial Geochemistry Research Experience for Undergraduates

Geochemical analyses are difficult because all samples have an unknown composition. As most geoscience programs do not teach “techniques” courses, teaching analytical technique and critical data analysis becomes a priority during the undergraduate research experience. The analysis of rivers is an excellent way to teach geochemical techniques because of the relative ease of sample collection and speed of sample analysis. The sample collection and processing steps, however, are subject to a variety of mistakes that affect sample integrity.This paper focuses on the potential sources of sample contamination during the sampling, filtering, and bottle cleaning processes, and reviews methods to reduce and detect contamination. Training at the beginning of a research program is helpful, but during a ten-week or shorter summer research experience, training time is of necessity short and much learning occurs in the actual research environment. An emphasis on contamination sources and the one million times dilution approach to cleaning will help avoid sample contamination. The cleaning process, though a critical analytical technique, is a tedious, dull, and seemingly menial task. As a result, faculty members engaged in undergraduate research experiences face a difficult task when teaching the need for cleanliness in the laboratory and field. The participating students, however, learn an important lesson of the need for “mindfulness” in the research process.

Application of the CN Intermediate-term Earthquake Prediction Algorithm to the Area of the Southern External Dinarides

—The paper presents the results of application of the CN algorithm to the area of the Southern External Dinarides. Two cases are considered—one for the knowledge gained throughout the considered period of time (1936–1996), and the other when learning ceased in 1986. In the first case 8 out of 9 strong earthquakes could have been predicted, three false alarms are declared (covering 7% of the total time considered) and TIPs occupy 32% of the total time. There is no clear relation between the TIPs duration and the size of the related earthquake. The second case (when the CN functions are defined on the basis of a shorter learning period) produces even slightly better results: only two false alarms are declared. In both cases current alarm exists in the region. All attempts to reduce the area of the regional polygon resulted in poorer prediction results.

Five-year follow-up of laparoscopic bladder neck suspension using synthetic mesh and surgical staples.

We report long-term follow-up of 40 patients who underwent a laparoscopic adaptation of the Burch procedure between May 1990 and December 1992. This procedure, in which synthetic mesh and surgical staples are used in place of sutures to effect the suspension, was previously described by the principal author and colleagues for use in the treatment of genuine stress urinary incontinence (J Laparoendosc Surg 1993;3:563-566). Minimum 5-year follow-up has been obtained for 34 of these patients either by office visit with the principal author (27 patients) or by telephone interview with the patient or the patient's primary-care physician (7 patients). Six patients were lost to follow-up, four after 1 year and two more after 3 years. None of these patients was leaking at last follow-up. This operation initially succeeded in resolving incontinence in 37 of 40 patients (93%). Of the three patients in whom the surgery failed initially, none chose further surgery, and all three were still leaking after 5 years of follow-up. One additional patient developed urgency incontinence 3 years postoperatively. The five-year success rate, defined as no recurrent leaking, was 88% (30 of 34 confirmed outcomes). This modification of the Burch procedure offers the advantages of the laparoscopic approach and affords an inherently shorter learning curve than that associated with laparoscopic suturing in the confined pelvic space.

Linking public health education and practice: the Australian experience.

The public health workforce in Australia is highly skilled, multifunctional, and drawn from a variety of backgrounds, including clinical practice and non-health areas. A wide range of activities is needed to meet the educational and training requirements of this workforce, including on the job inservice training, context specific continuing education programs and short courses, distance and self-directed learning packages, and postgraduate University level courses. The core components of public health today include: a social and political commitment to health, a shared responsibility between government and the public, and a multidisciplinary field of action. The challenge for those providing education and training for the public health workforce is to ensure graduates have the broad range of knowledge and skills needed in this climate. A system-wide approach to learning, where knowledge and skill development is related to the practices and settings of service and program delivery, will ensure strong links between education and practice.

Experimental On-Line Frequency Domain Identification and Adaptive Control of a Flexible Slewing Beam

This paper presents experimental results for the real-time adaptive identification and control of a flexible, slewing beam. A frequency domain identification algorithm incorporating non-parametric transfer function estimation and least squares parametric estimation is used to reconstruct an accurate parametric model of the system, capable of accurately tracking changing plant dynamics in real time. This model is subsequently used to produce an LQG compensator which actively damps beam vibration caused by rapid slewing manoeuvres with large payload changes. Non-persistent excitation is addressed in the context of identification during nominal motion. It is shown that after a short duration learning period, the proposed identification scheme will yield a model which is sufficiently accurate for controller synthesis.

Computed Tomographically Guided Biopsy of the Spine

Efficacy of the percutaneous biopsy of the spine under computed tomographic guidance was investigated. Seventy-five patients, ranging in age from 7 to 72 years, underwent this procedure. To determine the usefulness of computed tomographically guided biopsies in the treatment of patients with spinal disorders. The results of 68 biopsies (90.6%) were judged to be accurate insofar as the samples of tissue obtained could be diagnosed as specific types of neoplasm, infective lesions, reactive lesions of nonspecific type, or normal bone. Biopsies that yielded a specific abnormality were categorized as true positives. The "normal" biopsies were followed for 6-18 months and were then deemed true negatives. Nondiagnostic ones were considered false negatives. The results are acceptable with an accuracy rate of 90.6%. It is a safe and simple procedure with a short learning curve. Computed tomographically guided biopsy of the spine is recommended as a procedure of choice, especially in cervical and thoracic lesions. Computed tomography is superior to fluoroscopy when dealing with small, deep-seated lesions especially in the cervical and thoracic regions and with lesions picked up on bone scan only, radiographs being negative. Needle biopsy under computed tomographic guidance is safe and precise.

RECOGNITION OF RULES AND EXCEPTIONS BY NEURAL NETWORKS

A new method of training neural networks is suggested enabling them to retain their generalization capability without ignoring the learnt exceptions. Different implementations for this concept are explained. Simulation results indicate that a shorter learning time could also be obtained by using these networks. This concept could be generalized for automatic extraction of rules and exceptions by using neural nets that could be a step forward in the direction of integrating neural nets and knowledge based systems.

Debt illusion and imperfect information

The output and employment effects of bond finance depend critically on the assumption that government bonds are regarded by the public as net wealth. This paper analyzes the possibility that debt illusion can exist because of uncertainty about the economic opportunities: there is a learning problem. In some cases, traditional wealth effects can be rationalized in terms of rational short run learning behavior. In other cases, the same general considerations may lead to responses that are opposite to those usually assumed. And policies that have short run effects in the direction conventionally assumd may, in the long rung, reverse their direction of impact, thus giving rise to critical timing problems.