Ultrastructural localization of calcium and Ca2+-ATPase activity in gonadotrops and stellate cells of the catfish pituitary

In the pituitary of the African catfish, Clarias gariepinus, calcium precipitates were ultrastructurally visualized with the oxalate-pyroantimonate procedure (OPP). The presence of calcium in these precipiates was validated with several methods, including "Electron Energy Loss Spectrometry" (EELS). In the OPP-treated tissue calcium precipitates were seen in a) non-secretory stellate cells and b) gonadotropic (GTH-) cells. In the latter the amount of precipitate is generally low, but stimulation of the gonadotropin release, either in vivo or in vitro, resulted in a considerable increase. This increase is discussed in relation to the role of calcium as second messenger in the GTH-cells. Ca2+-ATPase was exclusively represented in stellate cells and GTH-cells, its strongest activity associated with the plasma membrane and with the membranes of the endoplasmic reticulum. The localization of this enzyme is discussed in relation to its role in the regulation of the intracellular calcium concentration in the GTH-cells. The stellate cells are considered to be involved in the regulation of extracellular calcium concentrations in the pituitary

Rethinking thinking aloud: A comparison of three think-aloud protocols

This paper presents the results of a study that compared three think-aloud methods: concurrent think-aloud, retrospective think-aloud, and a hybrid method. The three methods were compared through an evaluation of a library website, which involved four points of comparison: task performance, participants' experiences, usability problems discovered, and the cost of employing the methods. The results revealed that the concurrent method outperformed both the retrospective and the hybrid methods in facilitating successful usability testing. It detected higher numbers of usability problems than the retrospective method, and produced output comparable to that of the hybrid method. The method received average to positive ratings from its users, and no reactivity was observed. Lastly, this method required much less time on the evaluator's part than did the other two methods, which involved double the testing and analysis time

Usability and usefulness of a mobile health app for pregnancy-related work advice : mixed-methods approach

Acknowledgments The authors would like to thank all the pregnant participants who participated in the TA sessions and the employees of the obstetric care facilities. This pilot study received funding from ZonMw, the Netherlands Organization for Health Research and Development. This project is part of the Pregnancy and Birth Program.Peer reviewedPublisher PD

Limitations of the new ISO standard for health and wellness apps

International audienc

How to Reach Evidence-Based Usability Evaluation Methods

This paper discusses how and why to build evidence-based knowledge on usability evaluation methods. At each step of building evidence, requisites and difficulties to achieve it are highlighted. Specifically, the paper presents how usability evaluation studies should be designed to allow capitalizing evidence. Reciprocally, it presents how evidence-based usability knowledge will help improve usability practice. Finally, it underlines that evaluation and evidence participate in a virtuous circle that will help improve scientific knowledge and evaluation practic

Classification and regression tree and computer adaptive testing in cardiac rehabilitation: Instrument validation study

Background: There is a need for shorter-length assessments that capture patient questionnaire data while attaining high data quality without an undue response burden on patients. Computerized adaptive testing (CAT) and classification and regression tree (CART) methods have the potential to meet these needs and can offer attractive options to shorten questionnaire lengths. Objective: The objective of this study was to test whether CAT or CART was best suited to reduce the number of questionnaire items in multiple domains (eg, anxiety, depression, quality of life, and social support) used for a needs assessment procedure (NAP) within the field of cardiac rehabilitation (CR) without the loss of data quality. Methods: NAP data of 2837 CR patients from a multicenter Cardiac Rehabilitation Decision Support System (CARDSS) Web-based program was used. Patients used a Web-based portal, MyCARDSS, to provide their data. CAT and CART were assessed based on their performances in shortening the NAP procedure and in terms of sensitivity and specificity. Results: With CAT and CART, an overall reduction of 36% and 72% of NAP questionnaire length, respectively, was achieved, with a mean sensitivity and specificity of 0.765 and 0.817 for CAT, 0.777 and 0.877 for classification trees, and 0.743 and 0.40 for regression trees, respectively. Conclusions: Both CAT and CART can be used to shorten the questionnaires of the NAP used within the field of CR. CART, however, showed the best performance, with a twice as large overall decrease in the number of questionnaire items of the NAP compared to CAT and the highest sensitivity and specificity. To our knowledge, our study is the first to assess the differences in performance between CAT and CART for shortening questionnaire lengths. Future research should consider administering varied assessments of patients over time to monitor their progress in multiple domains. For CR professionals, CART integrated with MyCARDSS would provide a feedback loop that informs the rehabilitation progress of their patients by providing real-time patient measurements

Enhancing Inclusive mHealth Design for People Living with Dementia: Examples from Literature

The availability of mHealth technologies for older adults living with dementia is increasing. However, due to highly complex and varying clinical presentations of dementia, these technologies do not always meet their needs, wishes and capabilities. An exploratory literature review was performed to identify studies that applied evidence-based design principles or provide design choices that aim to improve mHealth design. These were categorized as a unique design choice to tackle barriers to mHealth use related to cognition, perception, physical ability, frame of mind, or speech- and language. Through thematic analysis, themes of design choices were summarized per category in the MOLDEM-US framework. Thirty-six studies were included for data extraction, leading to seventeen categories of design choices. This study pushes the need to further investigate and refine inclusive mHealth design solutions for populations with highly complex symptoms, such as those living with dementia

Towards a Lean Process for Patient Journey Mapping - A Case Study in a Large Academic Setting

Hospital quality improvement initiatives that focus on the patient experience are increasingly gaining attention. One of the known improvement methodologies is patient journey mapping. Central to this methodology is the mapping process, resulting in a patient journey map: a visual presentation of the complete route a patient follows during all stages of a care trajectory and the patients emotional experience during this journey: the patient journey map. Currently, there is no standard approach on how to perform the steps in the mapping process and evidence is lacking on the most effective and efficient way. As a result, the adoption of the methodology by healthcare professionals is hindered, more time than necessary is spent on the mapping and a lot of significant variation exists in the quality of the resulting patient journey maps. The Lean methodology has a proven track of record to optimize and standardize processes. Hence, by performing a Lean analysis onto the patient journey mapping process, opportunities to optimize and standardize the process may be identified. This study aimed to assess the value of Lean methodology to optimize patient journey mapping in a hospital setting. Observations and interviews were performed to identify the process for patient journey mapping in a Dutch academic hospital. Lean was used to visualize the process and identify inefficiencies. An expert panel reviewed the improvement suggestions. We conclude that Lean can provide value for aligning different views on the process, for structuring the process steps and phases and for identifying optimization actions in the mapping process

Classification and Regression Tree and Computer Adaptive Testing in Cardiac Rehabilitation: Instrument Validation Study

BACKGROUND: There is a need for shorter-length assessments that capture patient questionnaire data while attaining high data quality without an undue response burden on patients. Computerized adaptive testing (CAT) and classification and regression tree (CART) methods have the potential to meet these needs and can offer attractive options to shorten questionnaire lengths. OBJECTIVE: The objective of this study was to test whether CAT or CART was best suited to reduce the number of questionnaire items in multiple domains (eg, anxiety, depression, quality of life, and social support) used for a needs assessment procedure (NAP) within the field of cardiac rehabilitation (CR) without the loss of data quality. METHODS: NAP data of 2837 CR patients from a multicenter Cardiac Rehabilitation Decision Support System (CARDSS) Web-based program was used. Patients used a Web-based portal, MyCARDSS, to provide their data. CAT and CART were assessed based on their performances in shortening the NAP procedure and in terms of sensitivity and specificity. RESULTS: With CAT and CART, an overall reduction of 36% and 72% of NAP questionnaire length, respectively, was achieved, with a mean sensitivity and specificity of 0.765 and 0.817 for CAT, 0.777 and 0.877 for classification trees, and 0.743 and 0.40 for regression trees, respectively. CONCLUSIONS: Both CAT and CART can be used to shorten the questionnaires of the NAP used within the field of CR. CART, however, showed the best performance, with a twice as large overall decrease in the number of questionnaire items of the NAP compared to CAT and the highest sensitivity and specificity. To our knowledge, our study is the first to assess the differences in performance between CAT and CART for shortening questionnaire lengths. Future research should consider administering varied assessments of patients over time to monitor their progress in multiple domains. For CR professionals, CART integrated with MyCARDSS would provide a feedback loop that informs the rehabilitation progress of their patients by providing real-time patient measurements