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At least 613 records · Page 34Linked to original sources
PubMed2005

Effect of combined movement and heart rate monitor placement on physical activity estimates during treadmill locomotion and free-living.

A placement effect on activity measures from movement sensors has been reported during treadmill and free-living activity. Positioning of electrodes may impact on movement artifact susceptibility as well as surface ECG waveform amplitudes and thus potentially on the precision by which heart rate (HR) is ascertained from such ECG traces. The purpose of this study was to examine the extent to which placement of the combined HR and movement sensor, Actiheart, influences measurement of HR and movement, and estimates of energy expenditure. A total of 24 participants (20-39 years, 45-109 kg, 1.54-2.05 m, 19-29 kg m(-2)) were recruited. Whilst wearing two monitors, one placed at the level of the third intercostal space (upper position) and one just below the apex of the sternum (lower position), study participants performed level walking, incline walking, and level running on treadmill, and completed at least one day of free-living monitoring. Placement differences in HR data quality, movement counts, and energy expenditure (estimated from combined HR and movement) were analyzed with regression techniques. Quality of HR data was generally higher when monitors were placed in the lower position. This effect was more pronounced in men during both treadmill activity (relative risk, RR [95% CI] of noisy HR data in upper vs. lower position, RR=1.3[0.3; 5.6] in women, RR=174[14; 2,156] in men) and during free-living (RR=1.2[0.4; 3.3] in women, RR=25[9.6; 67] in men). There were minor placement differences (< or =8%) in movement counts only in women during incline walking and running. During free-living, no placement effect on counts was observed. In all test scenarios, estimates of energy expenditure from the two positions were not significantly different. Positioning the Actiheart at the level below the sternum may yield cleaner HR data. Regardless of which position is used, this has little or no effect on movement counts and energy expenditure estimates, which is encouraging for studies where research participants may have to position the monitors themselves.

Adult↗
PubMed1991

Ozone and the clean troposphere: ecological implications.

In recent years numerous investigations have examined the relationships between chronic ozone (O(3)) exposure and plant responses using statistical or empirical cause-effect models. One of the critically important decisions underlying these studies has been the choice of the control or reference O(3) exposure to which all other treatments are compared. The issue of the control or reference O(3) exposure is a complex one. Does a single ambient control or reference O(3) exposure exist? The approach taken in this paper is to examine the O(3) concentrations in the 'clean troposphere.' One must ask what a clean troposphere is and whether there are any geographic locations in the world today that are totally free of human influences. Data on photochemical oxidants from Fortress Mountain, Alberta, Canada, are examined. A comparison of these data with air quality data from other locations in North America is used to examine the design of vegetation response studies. The need for integrated research design, execution, and evaluation is stressed.

Journal Article↗
PubMed2005

Measures of health-related quality of life and functional status in survivors of oral cavity cancer who have had defects reconstructed with radial forearm free flaps.

The aim of this study was to evaluate (by postal questionnaire) quality of life and function in patients who have had resections of oral cancer and reconstruction by radial forearm flaps. Between October 1987 and December 2002, 258 patients had reconstructions by radial forearm flaps after resection of tumours in the oral cavity. Of these, 139 surviving patients were identified from the database and were sent questionnaires comprising five sections: Functional Assessment of Cancer Therapy-General (FACT-G) and -Head and Neck (FACT-HN); University of Washington Quality of Life Scale (UWQoL); Performance Status Scale for Head and Neck Cancer (PSS-HN); and the final section addressed dental rehabilitation and morbidity at the donor site. Sixty-three questionnaires (45%) were returned. In 17 (27%), parts of the questionnaire were incomplete. The median UWQoL score was 623/900, FACT-G was 92/108, FACT-HN was 31/48, and PSS-HN showed that eating in public, understandability of speech and normality of diet were 75/100, 75/100 and 50/100, respectively. The effect of stage and site on quality of life and function did not reach statistical significance. The effect of radiotherapy on speech (p=0.036) and diet (p=0.007) was significant. Patients who worried about their cancer returning had a lower UWQoL score (p=0.016). Ninety percent regarded their arm as disfigured, but 81% felt comfortable wearing short-sleeved shirts. Sensation and function of the hand were reported as normal in 87 and 92%, respectively. We conclude that patients who have had oral cancer have a persistent reduction in quality of life and function long after completion of treatment. The effects can be assessed by postal questionnaire, but the low rate of return (45%) and difficulties with completion reduce the quality of the data. Quality of life and function are essential components of improvements in outcome.

Adult↗
PubMed2005

Procedure for minimizing stress for fMRI studies in conscious rats.

Functional magnetic resonance imaging (fMRI) in conscious animals is evolving as a critical tool for neuroscientists. The present study explored the effectiveness of an acclimation procedure in minimizing the stress experienced by the animal as assessed by alterations in physiological parameters including heart rate, respiratory rate, and serum corticosterone levels. Results confirm that as the stress of the protocol is minimized, there is a significant decrease in head movements and enhancement in data quality. The feasibility of improving the quality of fMRI data acquired in alert rats by utilizing a relatively simple technique is presented.

Acclimatization↗
PubMed1989

Robotics in biomedical chromatography and electrophoresis.

The ideal laboratory robot can be viewed as "an indefatigable assistant capable of working continuously for 24 h a day with constant efficiency". The development of a system approaching that promise requires considerable skill and time commitment, a thorough understanding of the capabilities and limitations of the robot and its specialized modules and an intimate knowledge of the functions to be automated. The robot need not emulate every manual step. Effective substitutes for difficult steps must be devised. The future of laboratory robots depends not only on technological advances in other fields, but also on the skill and creativity of chromatographers and other scientists. The robot has been applied to automate numerous biomedical chromatography and electrophoresis methods. The quality of its data can approach, and in some cases exceed, that of manual methods. Maintaining high data quality during continuous operation requires frequent maintenance and validation. Well designed robotic systems can yield substantial increase in the laboratory productivity without a corresponding increase in manpower. They can free skilled personnel from mundane tasks and can enhance the safety of the laboratory environment. The integration of robotics, chromatography systems and laboratory information management systems permits full automation and affords opportunities for unattended method development and for future incorporation of artificial intelligence techniques and the evolution of expert systems. Finally, humanoid attributes aside, robotic utilization in the laboratory should not be an end in itself. The robot is a useful tool that should be utilized only when it is prudent and cost-effective to do so.

Chemistry, Clinical↗
PubMedDate not supplied

The management of a multisite study.

Large-scale multisite nursing research projects require careful coordination of a variety of research tasks. Many nursing studies include caregivers and support staff as well as patients and their significant others as subjects, resulting in the need to develop and implement many different protocols. This article presents an implementation framework for multisite clinical studies incorporating the knowledge gained during an investigation of patient-centered care that was conducted at 17 hospitals involving contact with patients, unit managers, registered nurses, and other hospital personnel. Five areas of key research tasks are addressed: general systems design, public relations, human resource issues, data quality assurances, and data management. Management of a multisite nursing research study, including issues related to recruitment and roles of project staff, training, and key research tasks, are discussed.

Clinical Nursing Research↗
PubMed2004

Variation in breast cancer counts using SEER and IARC multiple primary coding rules.

OBJECTIVE: To determine breast cancer case counts, on a given data set, using both Surveillance, Epidemiology, and End Results (SEER) program and International Agency for Research on Cancer (IARC) multiple primary coding rules and to describe differences, if any, by age at diagnosis, histology, stage at diagnosis, laterality, and grade. METHODS: SEER and IARC multiple primary coding rules were applied to a dataset provided by the North American Association of Central Cancer Registries. Only registries whose data met high quality data standards for the time period studied (1994-1998) and whose permission was obtained were included. Percentage differences were calculated using IARC counts as the base. RESULTS: Using IARC multiple primary rules resulted in 2.4% fewer cases. Among females, the highest percent changes by category were: age group - 80-84 year-olds (3.4%); histology - inflammatory breast cancer (4.6%); stage - distant (3.1%); grade - well differentiated (3.0%). Among males, the highest percent changes by category were: age group - 80-84 year-olds (1.7%); histology - for intraductal and lobular breast carcinoma in combination (4.8%); stage - distant (3.0%); grade - well differentiated (1.8%). Overall differences were generally unaffected when examined by laterality. CONCLUSION: Breast cancer case counts are dependent on the multiple primary coding rules used.

Age Factors↗
PubMedDate not supplied

Immunization information systems national research and evaluation agenda.

Immunization Information Systems (IIS) are operational in most states and are useful in programmatic and clinical assessments. To ensure that IIS reach their technical and usability potential, and to promote their use, we conducted a Delphi survey to develop a national IIS research and evaluation agenda. Experts with a wide range of IIS knowledge were asked to generate research and evaluation topics that document their utility in achieving and sustaining clinical and public health goals. Topics were then collated by the authors into 13 main categories and were ranked by the survey experts in order of importance. Provider perspectives and needs was ranked as the top research priority. Both data quality and technical data exchange also ranked high, as well as increasing provider participation and IIS cost and cost savings. Lower-ranked research priorities included data sharing between states and factors affecting IIS population-based measurements. Development of an IIS research and evaluation agenda allows policy makers to ensure that their decisions coincide with expert views on national priorities and enables researchers to conduct studies addressing topics recognized as nationally important. It also allows for targeted funding decisions.

Delphi Technique↗
PubMed2006

Medical management of left-sided ulcerative colitis and ulcerative proctitis: critical evaluation of therapeutic trials.

BACKGROUND: The goal of this work was to critically evaluate the published studies on the treatment of ulcerative proctitis (UP) and left-sided ulcerative colitis (L-UC). The results of this review provided the content for the accompanying treatment guidelines, Clinical Guidelines for the Medical Management of Left-sided Ulcerative Colitis and Ulcerative Proctitis: Summary Statement. METHODS: All English language articles published between 1995 and September 2005 were identified through a comprehensive literature search using OVID and PubMed. The quality of the data supporting or rejecting the use of specific therapies was categorized by a data quality grading scale. An "A+" grade was assigned to treatment supported by multiple high-quality randomized controlled trials with consistent results, whereas a "D" grade was given to therapy supported only by expert opinion. The therapeutic efficacy of a treatment was defined by its success in treating UP and L-UC compared with placebo. A medication was ranked as "excellent" if it was specifically studied for UP and L-UC and had consistently positive results compared with placebo or another agent. Quality and efficacy scores were agreed on by author consensus. RESULTS: For the acute treatment of UP or L-UC, the rectally administered corticosteroids and mesalazine (5-ASA), either alone or in combination with oral 5-ASAs, are the most effective therapy: evidence quality, A+; efficacy, excellent. Only rectally administered 5-ASA received an A+/excellent rating for maintenance of remission. Infliximab received an A+ grade for induction and maintenance of remission but only a "good" rating because the studies were performed in all UC, not specifically UP or L-UC. CONCLUSIONS: This critical evaluation of treatment provides a "report card" on medications available for the management of patients with UP and L-UC. The guidelines should provide a useful reference and supplement for physicians treating UC patients.

Adrenal Cortex Hormones↗
PubMed2002

Locating the anomalous scatterer substructures in halide and sulfur phasing.

Improved data quality now makes it feasible to exploit the weak anomalous signal derived only from the sulfurs inherent to the protein or in particular from halide ions incorporated by soaking. The latter technique requires the location of a high number of partially occupied halide sites. This number appears to be roughly proportional to the exposed protein surface. This paper explores the application of dual-space ab initio methods as implemented in the program SHELXD to the location of substructures of sulfur in SAD experiments, bromide in SAD and MAD experiments and iodide using SAD and SIRAS to determine the anomalous-atom substructure. Sets of atoms consistent with the Patterson function were generated as a starting point for the dual-space recycling procedure in SHELXD. The substructure is then expanded to the full structure by maximum-likelihood phasing with SHARP and density modification with the program DM. Success in the location of the substructures and subsequent phasing depends critically on the quality of the data and on the extent of the anomalous signal. This varies with each crystal and soak, but for the same crystal the significance of the anomalous signal was found to be highly sensitive to the redundancy of the intensity measurements, which in some cases made all the difference. This is illustrated by the determination of the previously unknown structure of repeat 11 of the human mannose-6-phosphate/insulin-like growth factor II receptor (Man6P/IGFII-receptor), with 310 amino acids in the asymmetric unit, which was phased by soaking the crystals in a cryoprotectant solution containing halide anions.

Amino Acid Sequence↗
PubMed2001

The process of knowledge discovery from large pharmacokinetic data sets.

The advent of statistical software with powerful graphical and modeling capabilities has revolutionized the manner in which pharmacokinetic and pharmacodynamic analyses are performed. Knowledge discovery from a large (population) pharmacokinetic data set incorporates all steps taken from data assembly to the development of a population pharmacokinetic model and the communication of the results thereof. The process can be formalized into a number of steps: (1) creation of a data set for pharmacokinetic knowledge discovery, (2) data quality analysis, (3) data structure analysis (exploratory examination of raw data), (4) determination of the basic pharmacokinetic model that best describes the data and generating post hoc empiric individual Bayesian parameter estimates, (5) the search for patterns and relationships between parameters and parameters and covariates by visualization, (6) the use of modern statistical modeling techniques for data structure revelation and covariate selection, (7) consolidation of the discovered knowledge into irreducible form (i.e., developing a population pharmacokinetic model), (8) the determination of model robustness (determination of the reliability of model parameter estimates), and (9) the communication and integration of the discovered pharmacokinetic knowledge. This process is discussed, and a motivating example is presented. The use of modern graphical, modeling, and statistical techniques for knowledge discovery from large pharmacokinetic data sets has given the data analyst the freedom to choose statistical methodology appropriate to the problem at hand with the maximization of information extraction, rather than on the basis of mathematical/statistical tractability.

Adolescent↗
PubMed2005

Overview of BioCreAtIvE: critical assessment of information extraction for biology.

BACKGROUND: The goal of the first BioCreAtIvE challenge (Critical Assessment of Information Extraction in Biology) was to provide a set of common evaluation tasks to assess the state of the art for text mining applied to biological problems. The results were presented in a workshop held in Granada, Spain March 28-31, 2004. The articles collected in this BMC Bioinformatics supplement entitled "A critical assessment of text mining methods in molecular biology" describe the BioCreAtIvE tasks, systems, results and their independent evaluation. RESULTS: BioCreAtIvE focused on two tasks. The first dealt with extraction of gene or protein names from text, and their mapping into standardized gene identifiers for three model organism databases (fly, mouse, yeast). The second task addressed issues of functional annotation, requiring systems to identify specific text passages that supported Gene Ontology annotations for specific proteins, given full text articles. CONCLUSION: The first BioCreAtIvE assessment achieved a high level of international participation (27 groups from 10 countries). The assessment provided state-of-the-art performance results for a basic task (gene name finding and normalization), where the best systems achieved a balanced 80% precision / recall or better, which potentially makes them suitable for real applications in biology. The results for the advanced task (functional annotation from free text) were significantly lower, demonstrating the current limitations of text-mining approaches where knowledge extrapolation and interpretation are required. In addition, an important contribution of BioCreAtIvE has been the creation and release of training and test data sets for both tasks. There are 22 articles in this special issue, including six that provide analyses of results or data quality for the data sets, including a novel inter-annotator consistency assessment for the test set used in task 2.

Computational Biology↗
PubMed2005

ParPEST: a pipeline for EST data analysis based on parallel computing.

BACKGROUND: Expressed Sequence Tags (ESTs) are short and error-prone DNA sequences generated from the 5' and 3' ends of randomly selected cDNA clones. They provide an important resource for comparative and functional genomic studies and, moreover, represent a reliable information for the annotation of genomic sequences. Because of the advances in biotechnologies, ESTs are daily determined in the form of large datasets. Therefore, suitable and efficient bioinformatic approaches are necessary to organize data related information content for further investigations. RESULTS: We implemented ParPEST (Parallel Processing of ESTs), a pipeline based on parallel computing for EST analysis. The results are organized in a suitable data warehouse to provide a starting point to mine expressed sequence datasets. The collected information is useful for investigations on data quality and on data information content, enriched also by a preliminary functional annotation. CONCLUSION: The pipeline presented here has been developed to perform an exhaustive and reliable analysis on EST data and to provide a curated set of information based on a relational database. Moreover, it is designed to reduce execution time of the specific steps required for a complete analysis using distributed processes and parallelized software. It is conceived to run on low requiring hardware components, to fulfill increasing demand, typical of the data used, and scalability at affordable costs.

Algorithms↗
PubMed2003

Health research and the Data Protection Act 1998.

The 1998 Data Protection Act in the UK largely restates existing good practice: individuals have a right to know what data are held about them and why; and those processing data have a duty to proceed with fairness and transparency, maintain high data quality and keep data secure. Some health researchers have criticised the Act, seeing it as a legal minefield, unnecessary bureaucracy and interference from the European Union. This is largely based on misconceptions. Recent guidance from the Information Commissioner aims to assist researchers by advising how legal requirements can be met through anonymisation of data, attention to data-processing methods and fair collection of data. The Act provides a clear framework of rights and responsibilities that should be embraced with enthusiasm rather than with the reluctance of a person forced to carry out a meaningless chore.

Access to Information↗
PubMed2002

Health care reform: opportunities for professional chaplains to build intentional communities of learners by integrating faith, science, quality, and systems thinking.

Albert Einstein once said, "The significant problems we face cannot be solved at the same level of thinking we were at when we created them" (www.brainyquote.com). Health care reform has brought professional chaplains to a place of chaos-a place that raises many questions about the past, present and future. This chaos presents tremendous opportunities for professional chaplains to increase their capacities in building intentional communities of learners by integrating faith, science, quality and systems thinking. Pastoral care givers must truly understand the pressures from all sides and the new emerging paradigm of integrated health care delivery. Without this understanding, we will not see the opportunities and challenges of integrating pastoral and spiritual care in the emerging structures and systems. The future of chaplaincy largely will depend on the quality of the data, quality of our conversations and our ability to thinking together through dialogue.

Health Care Reform↗
PubMed2001

[Hereditary nonpolyposis colorectal carcinoma (HNPCC): surgical aspects].

1-5% of all patients presenting with colorectal cancer, have an underlying genetic predisposition with an autosomal dominant of pattern of inheritance. Recently the underlying molecular genetic pathway of this syndrome known as HNPCC (hereditary nonpolyposis colorectal cancer) has been characterized: the predisposition is due to a pathogenic mutation in one of the DNA mismatch-repair genes. Colorectal cancers are the leading characterisitic of the syndrom and are frequently encountered at a young age of onset. However, endometrial cancer, stomach cancer, small bowel cancer, urinary tract cancer and skin cancer among others are also inherent to the syndrome. Based on the identification of the underlying molecular genetic pathway, predictive testing has become an option. Once the family-specific underlying pathogenic mutation in one of the DNA mismatch-repair genes has been identified in a proband, at-risk family members may be offered DNA testing with an unequivocal answer to if or if not they have inherited the increased cancer susceptibility. Multiple facets of family DNA testing require a multidisciplinary approach integrating clinicians, geneticists, psychologists, molecular biologist and pathologists. Mutations are identified in a rate of 50-60% of families complying with the Amsterdam criteria for HNPCC. The incidence of recta cancer in HNPCC has as yet not clearly been defined, due to a lack of unequivocal data. In a retrospective analysis (submitted) rectal cancers were encountered in 30% of the HNPCC patients. Half of the patients affected developed metachronous colon cancers. It is essential to address the issue of prophylactic surgery in HNPCC patients presenting with colorectal cancer: Prospective data is required in order to decide which of the options is more beneficial for the HNPCC patient presenting with his first colorectal primary: subtotal colectomy and ileorectal anastomosis versus restorative proctocolectomy. It is evident that apart from the more clinical data quality of life data must be evaluated in this study.

Colectomy↗
PubMed2003

Epidemiological studies based on small sample sizes--a statistician's point of view.

We consider 3 basic steps in a study, which have relevance for the statistical analysis. They are: study design, data quality, and statistical analysis. While statistical analysis is often considered an important issue in the literature and the choice of statistical method receives much attention, less emphasis seems to be put on study design and necessary sample sizes. Finally, a very important step, namely assessment and validation of the quality of the data collected seems to be completely overlooked. Examples from veterinary epidemiological research and recommendations for each step are given together with relevant references to the literature.

Animals↗