Testing based on the RELAY model of error detection

RELAY, a model for error detection, defines revealing conditions that guarantee that a fault originates an error during execution and that the error transfers through computations and data flow until it is revealed. This model of error detection provides a fault-based criterion for test data selection. The model is applied by choosing a fault classification, instantiating the conditions for the classes of faults, and applying them to the program being tested. Such an application guarantees the detection of errors caused by any fault of the chosen classes. As a formal mode of error detection, RELAY provides the basis for an automated testing tool. This paper presents the concepts behind RELAY, describes why it is better than other fault-based testing criteria, and discusses how RELAY could be used as the foundation for a testing system

An analysis of test data selection criteria using the RELAY model of fault detection

RELAY is a model of faults and failures that defines failure conditions, which describe test data for which execution will guarantee that a fault originates erroneous behavior that also transfers through computations and information flow until a failure is revealed. This model of fault detection provides a framework within which other testing criteria's capabilities can be evaluated. In this paper, we analyze three test data selection criteria that attempt to detect faults in six fault classes. This analysis shows that none of these criteria is capable of guaranteeing detection for these fault classes and points out two major weaknesses of these criteria. The first weakness is that the criteria do not consider the potential unsatisfiability of their rules; each criterion includes rules that are sufficient to cause potential failures for some fault classes, yet when such rules are unsatisfiable, many faults may remain undetected. Their second weakness is failure to integrate their proposed rules; although a criterion may cause a subexpression to take on an erroneous value, there is no effort made to guarantee that the intermediate values cause observable, erroneous behavior. This paper shows how the RELAY model overcomes these weaknesses

Manipulator arm design for the Extravehicular Teleoperator Assist Robot (ETAR): Applications on the space station

The preliminary conceptual design of a new teleoperator robot manipulator system for space station maintenance missions has been completed. The system consists of a unique pair of arms that is part of a master-slave, force-reflecting servomanipulator. This design allows greater dexterity and greater volume coverage than that available in current designs and concepts. The teleoperator manipulator is specifically designed for space applications and is a valuable extension of the current state-of-the-art earthbound manipulators marketed today. The manipulator and its potential application on the space station are described

The development of community service for young children in the New Forest: Joint work by a child guidance clinic with health visitors

This work was developed from a child guidance clinic in the New Forest over a period of 15 years from 1984-99. This service was developed with the aim of devolving and disseminating knowledge to allow interventions to take place at the lowest possible level in the system. A strategy to realise these aims was developed and data was collected to monitor progress. This thesis will describe the strategic approach adopted, in order to develop the service: 1. A review of the background literature relevant to the work proposed. 2. A needs' assessment of behaviour problems young preschool children in our district in order to establish what kind of service should be offered. This was a community survey of a total birth cohort of children at age 3 years at the time of their developmental screen. Questionnaires were sent 10 out to families with their invitation to their child's developmental check. This established that the prevalence of behaviour problems found in three year old children in this urban/rural area (14.2%) was similar to the findings of the urban community study of three year old children carried out by Richman, Stevenson & Graham, (1982). 3. The development of ongoing training and support for health visitors in order that they would be able to assess families with young children, screen for problems and institute treatment methods. 4. The development of behaviour programmes that would work within a community setting. An evaluation of the efficacy of treatment of sleep problems by a specialised health visitor in the community was undertaken with a Grant from the South and South West Regional Health Authority. This Trial was a randomised- controlled trial of the delivery of a manualised sleep programme for non-sleeping 2-4 year olds (Douglas & Richman, 1982) delivered by a specialised health visitor over a eight week period at the family's home. The results were clinically significant although just without statistical significance (p=.05 CI -.005 to 5.8). 5. The development of a clinic for young children within the Child Guidance Service in order to encourage appropriate referrals and encourage joint working with the health visitors. 6. Outcome measures were developed to evaluate the clinic work including a tool to assess families' satisfaction. Outcome was measured by the family and clinic independently using a 6-point, unanchored, Likert Scale filled in at assessment and on discharge. Results found that both families and the clinic staff indicated improvement and there was agreement by families and clinicians as to whom had improved. 7. An evaluation of work at Tier I, 11 and 111. Can liaison nurses work within the community, from a base within the child guidance service. A comparison of results from a clinic based service and a community based service indicated that the results for staff working in the community by themselves, were as good as two or more staff working in the clinic but at half the cost. Better liaison with primary care was achieved while working in localities. (Abstract shortened by ProQuest.)

The influence of maternal psychosocial characteristics on infant feeding styles

Maternal feeding styles in infancy and early childhood are associated with children’s later risk for overweight and obesity. Maternal psychosocial factors that influence feeding styles during the complementary feeding period, the time during which infants transition from a milk-based diet to one that includes solid foods and other non-milk products, have received less attention. The present study explores how maternal psychosocial factors—specifically self-esteem, parenting self-efficacy, parenting satisfaction, and depression symptoms—influence mothers’ infant feeding styles at nine months of age, a time during which solid foods eating habits are being established. Participants included 160 low-income, African-American mother-infant pairs in central North Carolina who were enrolled in the Infant Care and Risk of Obesity Study. Regression models tested for associations between maternal psychosocial characteristics and pressuring and restrictive feeding styles. Models were first adjusted for maternal age, education, marital status and obesity status. To account for infant characteristics, models were then adjusted for infant weight-for-length, distress to limitations and activity level scores. Maternal self-esteem was negatively associated with pressuring to soothe. Maternal parenting self-efficacy was positively associated with restriction-diet quality. Maternal parenting satisfaction and depression symptoms were not associated with feeding styles in the final models. Focusing on strengthening maternal self-esteem and parenting self-efficacy may help to prevent the development of less desirable infant feeding styles

Psychometric Properties of the Family Caregiver Delirium Knowledge Questionnaire

A valid, reliable measure of family caregivers’ knowledge about delirium was not located in the literature; such an instrument is essential to assess learning needs and outcomes of education provided. The purpose of the current study was to (a) develop a family Caregiver Delirium Knowledge Questionnaire (CDKQ) based on the Symptom Interpretation Model; and (b) establish validity and reliability of the measure. The 19-item CDKQ was developed and administered to 164 family caregivers for community-dwelling older adults. Descriptive statistics were examined for all variables. Psychometric testing included confirmatory factor analysis, item-to-total correlations, and internal consistency reliability. A three-factor model provided the best fit for the data. The findings support initial validity and reliability of the CDKQ with family caregivers. Although the CDKQ was developed for use with family caregivers, it has potential for use with other caregivers, such as home health aides

The probable, possible, and novel functions of ERp29

The luminal endoplasmic reticulum (ER) protein of 29 kDa (ERp29) is a ubiquitously expressed cellular agent with multiple critical roles. ERp29 regulates the biosynthesis and trafficking of several transmembrane and secretory proteins, including the cystic fibrosis transmembrane conductance regulator (CFTR), the epithelial sodium channel (ENaC), thyroglobulin, connexin 43 hemichannels, and proinsulin. ERp29 is hypothesized to promote ER t

Eradication of hepatitis C infection: the importance of targeting people who inject drugs

Hepatitis C virus (HCV) affects ~170 million people worldwide and causes significant morbidity and mortality.1 In high-income countries, people who inject drugs (PWID) are at greatest risk of HCV infection.2 Until recently HCV eradication seemed unlikely, but recent advances in HCV treatment and improved understanding of the effectiveness of harm-reduction intervention effectiveness give reason for optimism. Current HCV treatments can cure ~75% of patients and new drugs will further improve effectiveness (over 90% cure) and improve tolerability.3 If HCV treatment can be delivered effectively to those at highest risk of onward transmission, significant reductions in future HCV cases are possible. The feasibility of disease eradication must be assessed on both scientific criteria (e.g., epidemiological susceptibility, effective and practical intervention available, and demonstrated feasibility of elimination) and political criteria (e.g., burden of disease, cost of intervention).4 With effective, curative treatment now available, HCV meets these criteria

Well-managed grazing systems: A forgotten hero of conservation

Ecologically sound grazing management is an underused and underappreciated conservation tool in the eastern United States. We contend that significant policy and educational barriers stand in the way of expanding the use of this conservation tool. Well-managed pasture systems combine vigorous perennial vegetation cover, reduced pesticide and fertilizer inputs, and lower costs of production using ecological approaches to generate ecosystem services for society, as well as economic sustainability for the producer. The majority of currently available conservation policy tools were designed to address either rangeland grazing situations in the western United States or conservation cropping in the eastern United States. To promote well-managed pastures in the eastern United States, resource managers and government agencies struggle to adapt programs that are really designed for annual row crop systems. Additional educational and technical assistance resources are needed for promoting well-managed pasture-based farming in the region. This paper summarizes the potential of well-managed pasture systems to provide ecosystem services, provides thoughts for discussion on the barriers to adoption of such systems in the eastern United States, and offers some solutions to move such systems forward through policy and educational efforts. These ideas were first presented at a symposium as part of the 2011 Annual Conference of the Soil and Water Conservation Society in Washington, DC

New Insights into Bacterial Chemoreceptor Array Structure and Assembly from Electron Cryotomography

Bacterial chemoreceptors cluster in highly ordered, cooperative, extended arrays with a conserved architecture, but the principles that govern array assembly remain unclear. Here we show images of cellular arrays as well as selected chemoreceptor complexes reconstituted in vitro that reveal new principles of array structure and assembly. First, in every case, receptors clustered in a trimers-of-dimers configuration, suggesting this is a highly favored fundamental building block. Second, these trimers-of-receptor dimers exhibited great versatility in the kinds of contacts they formed with each other and with other components of the signaling pathway, although only one architectural type occurred in native arrays. Third, the membrane, while it likely accelerates the formation of arrays, was neither necessary nor sufficient for lattice formation. Molecular crowding substituted for the stabilizing effect of the membrane and allowed cytoplasmic receptor fragments to form sandwiched lattices that strongly resemble the cytoplasmic chemoreceptor arrays found in some bacterial species. Finally, the effective determinant of array structure seemed to be CheA and CheW, which formed a “superlattice” of alternating CheA-filled and CheA-empty rings that linked receptor trimers-of-dimer units into their native hexagonal lattice. While concomitant overexpression of receptors, CheA, and CheW yielded arrays with native spacing, the CheA occupancy was lower and less ordered, suggesting that temporal and spatial coordination of gene expression driven by a single transcription factor may be vital for full order, or that array overgrowth may trigger a disassembly process. The results described here provide new insights into the assembly intermediates and assembly mechanism of this massive macromolecular complex