Constrained trajectory optimization for kinematically redundant arms

Two velocity optimization schemes for resolving redundant joint configurations are compared. The Extended Moore-Penrose Technique minimizes the joint velocities and avoids obstacles indirectly by adjoining a cost gradient to the solution. A new method can incorporate inequality constraints directly to avoid obstacles and singularities in the workspace. A four-link arm example is used to illustrate singularity avoidance while tracking desired end-effector paths

Why are we still promoting breast self-examination?

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Ecology and physiology of dormancy in a changing world: introduction to a virtual symposium

Author Posting. © University of Chicago, 2019. This article is posted here by permission of University of Chicago for personal use, not for redistribution. The definitive version was published in Biological Bulletin 237(2), (2019): 73-75, doi: 10.1086/706563.Dormancy is a widespread strategy used by diverse animal groups to persist through adverse environmental conditions, spread reproductive risk, and optimize seasonal phenology. Dormancy is an overarching term that refers to a reduction in metabolism, growth, and development; and different types of dormancy have been defined. Quiescence is directly initiated and terminated in response to environmental conditions, while diapause requires a preparatory phase that usually anticipates the onset of unfavorable conditions and also requires some minimum dormancy period (refractory phase) prior to termination. Dormancy is a fundamental feature of seasonal food web dynamics. Zooplankton populations can rapidly boom as individuals emerge from dormancy to feed on ephemeral algal blooms. Such productivity is critical to sustaining higher predators and supporting fisheries, particularly the growth of larval fish. Dormancy traits undergo selective pressure as zooplankton optimize developmental timing to maximize food availability and minimize predation pressure. As oceans warm and environments change, the relationship between dormancy cues, such as temperature and photoperiod, can shift, with as yet unknown effects on the timing of dormancy and resulting ecosystem dynamics. Future ecosystem dynamics are difficult to predict in part because we do not fully understand the cues that regulate the initiation or termination of dormancy, or how dormancy traits may change over time through acclimation and adaptation.2020-10-1

Glens Falls, New York: An Industrial Perspective

This paper examines the decline and changing nature of work in the manufacturing sector in a variety of industries located in the city of Glens Falls, New York. A small industrial city, Glens Falls has experienced an overall decline in population, the number of industries, plant locations, and total manufacturing employment. An examination of eleven companies, including the history and nature of operations, confirms a cycle of manufacturing job creation and job destruction which ebbs and flows based on the restructuring activities of companies including shifting, consolidating and closing plants as they strive to maintain and increase profitability. In the community of Glens Falls, this has resulted in an overall decline in manufacturing jobs. Interviews with individual workers with long work histories in manufacturing jobs provide perspective on the changing nature of their work as new machinery and automation of processes have been implemented. Several workers also recount their experiences in declining industries, the loss of their jobs, and their inability to obtain similar employment. The existence of fewer manufacturing job opportunities has permanently altered the availability of employment for displaced factory workers as well as the next generation of workers in this and other industrial cities

Integrating health promotion into nursing curricula in Hong Kong

The health care system in Hong Kong has historically been steeped in the biomedical paradigm. Health care reform, however, is finally putting health promotion on the agenda of governments and health care providers. As the largest group of providers in Hong Kong, nurses must assume a leadership role in the transition of the current illness-focused system to one that emphasizes health and promotes wellness. For nurses to take up the challenge of health promotion, they need to acquire the requisite knowledge and skills. Nursing curricula must emphasize this new paradigm and provide opportunities for students to develop expertise in health promotion and disease prevention. This article describes a health-promotion initiative carried out by 1st-year students in an undergraduate nursing program in Hong Kong. The health-promotion project aims to prepare graduates who will be able to meet health care needs and function effectively in the future health care system. Not only will these nurses be capable of becoming future leaders of the health-promotion movement in Hong Kong, they are also contributing to the health and wellness of Hong Kong citizens.published_or_final_versio

Exploring childhood immunization uptake with first nations mothers in north-western Ontario, Canada

Background. Childhood immunization is an important component of preventive health care for young children. Successful control of vaccine-preventable diseases depends on high levels of immunization coverage. Immunization statistics show that on-reserve First Nations (Native Indian) children have lower vaccination coverage than children in the general Canadian population. There has been little research, however, conducted with First Nations populations on this topic. Aim of the study. This study explored First Nations parents' beliefs about childhood immunizations and examined factors influencing immunization uptake. Methods. This study used a qualitative descriptive design to explore the issue of childhood immunization uptake. Twenty-eight mothers from two First Nations communities in north-western Ontario, Canada, were interviewed about their perceptions of childhood immunizations and vaccine-preventable diseases. The interviews were transcribed and content analysis was used to examine the data. Findings. Data analysis revealed the following six themes: (1) the fear of disease; (2) the efficacy of immunizations; (3) the immunization experience; (4) the consequences of immunization; (5) interactions with health professionals; and (6) barriers to immunizations. Participants were motivated to seek immunizations for their children by a fear of vaccine preventable diseases. A small proportion of mothers, however, questioned the effectiveness of vaccines in preventing disease. Traumatic immunization experiences, vaccine side-effects and sequelae, negative interactions with health professionals, and barriers such as time constraints and childhood illnesses all served as deterrents to immunization. Conclusions. The research outcomes highlight the varied beliefs of First Nations parents about childhood immunizations and the numerous factors that both positively and negatively influence immunization uptake. Further research is needed to explore the issue of childhood immunizations in First Nations communities and to determine strategies to improve uptake.postprin

A comparison of the psychometric properties of three- and four-option multiple-choice questions in nursing assessments

In multiple-choice tests, four-option items are the standard in nursing education. There are few evidence-based reasons, however, for MCQs to have four or more options as studies have shown that three-option items perform equally as well and the additional options most often do not improve test reliability and validity. The aim of this study was to examine and compare the psychometric properties of four-option items with the same items rewritten as three-option items. Using item-analysis data to eliminate the distractor with the lowest response rate, we compared three- and four-option versions of 41 multiple-choice items administered to two student cohorts over two subsequent academic years. Removing the non-functioning distractor resulted in minimal changes in item difficulty and discrimination. Three-option items contained more functioning distractors despite having fewer distractors overall. Existing distractors became more discriminating when infrequently selected distractors were removed from items. Overall, three-option items perform equally as well as four-option items. Since three-option items require less time to develop and administer and additional options provide no psychometric advantage, teachers are encouraged to adopt three-option items as the standard on multiple-choice tests. © 2009 Elsevier Ltd.postprin

An adaptive controller for enhancing operator performance during teleoperation

An adaptive controller is developed for adjusting robot arm parameters while manipulating payloads of unknown mass and inertia. The controller is tested experimentally in a master/slave configuration where the adaptive slave arm is commanded via human operator inputs from a master. Kinematically similar six-joint master and slave arms are used with the last three joints locked for simplification. After a brief initial adaptation period for the unloaded arm, the slave arm retrieves different size payloads and maneuvers them about the workspace. Comparisons are then drawn with similar tasks where the adaptation is turned off. Several simplifications of the controller dynamics are also addressed and experimentally verified

A Framework for improving the quality of multiple-choice assessments

Multiple-choice questions are frequently used in high-stakes nursing assessments. Many nurse educators, however, lack the necessary knowledge and training to develop these tests. The authors discuss test development guidelines to help nurse educators produce valid and reliable multiple-choice assessments. © 2012 Wolters Kluwer Health Lippincott Williams & Wilkins.postprin