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At least 541 records · Page 30Linked to original sources
PubMed2000

Physical activity in children and adolescents with congenital heart disease. Aspects of measurements with an activity monitor.

The aim of the present study was to evaluate different aspects of a device designed to monitor physical activity. Measurements of different axes and placement of the monitor were tested using a treadmill with ranging increments in incline or speed. The monitor was also used to assess the level of physical activity among children and adolescents with congenital heart disease and in healthy controls at the same age. The results indicate that the monitor is a valid and reproducible instrument for measurements of physical activity. The study revealed that the level of activity was higher for healthy boys than healthy girls (p<0.0001). Boys with congenital heart disease also displayed higher values compared to girls with congenital heart disease, although the difference was not significant (p=0.067). Healthy boys revealed a significantly higher level of activity than did boys with congenital heart disease (p=0.003), but no such difference was found in girls (p=0.757). Nor were any differences found between younger and older individuals among patients with congenital heart disease. Young healthy controls, however, showed significantly higher levels of activity than their older counterparts. There were differences in activity monitored during the week, with lower activity in the weekends, but the activity on the same day in different weeks seemed stable. Neither were there any differences between measurements over whole weeks. The results indicate that the Computer Science & Application monitor is a valid instrument for assessing physical activity. The monitor may also be used, therefore, to validate the levels of physical activity level in children with congenital heart disease after medical and surgical treatment.

Adolescent↗
PubMedDate not supplied

[Internet and psychopathology: an analysis of the use of the Web by 1075 students at secondary school].

AIMS: The purpose of this research is to make a contribution to analysing the complex issue of the relationship between Internet use and psychological disorders, and proposes a survey of the typical features and effects of such use among a sample of secondary school students. PATTERN: The research was carried out on a sample of 1075 students aged 14-21 from two secondary schools, where students are prevalently male in one and female in the other; computer science is part of the teaching programme in both institutes. INSTRUMENTS USED: General Health Questionnaire (GHQ), Goldberg's 28-item version, together with a form to collect individual and social data and information about the actual use of Internet, such as number of years, number of hours a day/a week, subjective experience, quantitative-qualitative perception of the connection. RESULTS: There is a clear and significant correlation between weekly hours of use and GHQ scores. CONCLUSIONS: Analysis of our sample confirms certain statements found in the relevant literature concerning a possible relationship between the use of Internet and psychological disorders. DECLARATION OF INTEREST: none.

Adult↗
PubMedDate not supplied

Functional genomic technologies: creating new paradigms for fundamental and applied biology.

New technologies that analyze the behavior of thousands of genes in parallel are creating, for the first time, a foundation of data for building integrated models of cellular processes. This review discusses the general issues of utilizing genomic methods in fundamental and applied research settings, using the study of stress responses and improvement of secondary metabolite production as examples. A fusion of concepts from biological and nonbiological disciplines, including mathematics, computer science, physics, chemistry, and engineering, is required to address the theoretical and experimental challenges facing the field of genomics, and together promise great breakthroughs in our understanding and engineering of cellular systems.

Biotechnology↗
PubMed2003

Why nature chose A, C, G and U/T: an error-coding perspective of nucleotide alphabet composition.

The question of whether the size and make-up of the natural nucleotide alphabet is a consequence of selection pressure, or simply a frozen accident, is one of the fundamental questions of biology. Nucleotide replication is essentially an information transmission phenomenon, and so it seems reasonable to explore the issue from the perspective of theoretical computer science, and of error-coding theory in particular. In this analysis it is shown that the essential recognition features of nucleotides may be naturally expressed as 4-digit binary numbers, capturing the hydrogen acceptor/donor patterns (3-bits) and the purine/pyrimidine feature (1-bit). Optimal alphabets consist of nucleotides in which the purine/pyrimidine feature is related to the acceptor/donor pattern as a parity bit. Numerically interpreted, such alphabets correspond to parity check codes, simple but effective error-resistant structures. The natural alphabet appears to be an adaptation of one of two optimal solutions, constrained to its present size and composition by a combination of chemical and coding-theory factors.

Base Composition↗
PubMed2004

Epigenesis and dynamic similarity in two regulatory networks in Pseudomonas aeruginosa.

Mucoidy and cytotoxicity arise from two independent modifications of the phenotype of the bacterium Pseudomonas aeruginosa that contribute to the mortality and morbidity of cystic fibrosis. We show that, even though the transcriptional regulatory networks controlling both processes are quite different from a molecular or mechanistic point of view, they may be identical from a dynamic point of view: epigenesis may in both cases be the cause of the acquisition of these new phenotypes. This was highlighted by the identity of formal graphs modelling these networks. A mathematical framework based on formal methods from computer science was defined and implemented with a software environment. It allows an easy and rigorous validation and certification of these models and of the experimental methods that can be proposed to falsify or validate the underlying hypothesis.

Epigenesis, Genetic↗
PubMed2004

Swedish medical students' views of the changing professional role of medical doctors and the organisation of health care.

Medical students will influence future health care considerably. Their professional orientation while at medical school will be related to their future professional development. Therefore, it is important to study this group's view of the role of medical doctors, especially because Swedish health care is currently undergoing major changes and financial cut backs. Here, the theoretical framework was contemporary theories of competence development, which has shown that people's understanding of their work influences their actions. The aim of this study was to describe medical students' views of their future professional role in health care. In total, 57 fourth-year medical students at a Swedish university were asked to write a short essay about how they conceptualised their professional role in future health care. Fifty-three students (93%) replied. The essays were analysed qualitatively in three steps and four themes were subsequently identified: the professional role in change, organisation of health care, working conditions and the possibilities of having a balanced life. Some factors mentioned that would strongly influence the professional role were being team leader, increased specialisation, supporting the patient and computer science and technology. The students expressed ambiguous feelings about power and leadership. The results indicate that the students share a rather dark view of both the medical profession and health care, which seems to be related to stress and financial cut backs. Mentoring, time for reflection and changes in the curricula might be needed.

Delivery of Health Care↗
PubMed2003

Gender and age differences in relation to the recommendations of physical activity among Norwegian children and youth.

The Norwegian physical activity recommendations for children and youth state that there should be a minimum of 60 min of physical activity of at least moderate intensity every day. The purpose of this study was to evaluate objectively the level of physical activity in a representative cohort of urban children and youth in Norway with regard to these recommendations. Four hundred and ten 9-year-old and 350 15-year-old boys and girls from the Oslo region participated. Physical activity was registered for 4 consecutive days using the Computer Science and Application activity monitor. The results showed that 86.2% of the 9-year-olds and 55.4% of the 15-year-olds met the recommendations. Furthermore, the activity level was significantly (P< 0.0001) higher among boys than girls of both age groups and significantly (P<0.001) lower in the oldest cohort than in the youngest one. All participants were less active during the weekend than during the weekdays (P< 0.05). In conclusion, a number of urban children and youth do not fulfill the Norwegian physical activity recommendations, especially among the 15-year-olds. It is therefore important to provide action towards those children and youth who are least physically active and simultaneously prevent the general decline in physical activity.

Adolescent↗
PubMed2000

Quantitative assessment of properties of make-up products by video imaging: application to lipsticks.

BACKGROUND/AIMS: The different properties and visual effects of lipstick have been studied by image analysis directly on volunteers. METHODS: After controlling the volunteer's position mechanically using an ophthalmic table and visually using an acquirement mask, which is an indicator of luminance and guide marks, we carried out video colour images of the make-up area. From these images, we quantified the colour, gloss, covering power, long-lasting effect and streakiness, using computer science programs. RESULTS/CONCLUSION: Quantitative colorimetric assessment requires the transformation of the RGB components obtained by a video colour camera into CIELAB colorimetric space. The expression of each coordinate of the L*a*b* space according to R,G,B was carried out by a statistical method of polynomial approximations. A study, using 24 colour images extracted from a Pantone(R) palette, showed a very good correlation with a Minolta Colorimeter(R) CR 300. The colour assessment on volunteers required a segmentation method by maximizing the entropy. The aim was to separate the colour information sent back by the skin to the make-up area. It was very useful to precisely delimit the contour between the skin and the product in the case of almost identical colours and to evaluate the streakiness. From this colour segmentation, an algorithm was studied to search for the shades most represented in the overall colour of the make-up area. The capacity to replicate what the consumer perceives of the make-up product, to carry out studies without having any contact with the skin surface, and the constant improvement of software and video acquirement systems all make video imaging a very useful tool in the quantitative assessment of the properties and visual effects of a make-up product.

Journal Article↗
PubMed2006

Back to the future: education for systems-level biologists.

We describe a graduate course in quantitative biology that is based on original path-breaking papers in diverse areas of biology; each of these papers depends on quantitative reasoning and theory as well as experiment. Close reading and discussion of these papers allows students with backgrounds in physics, computational sciences or biology to learn essential ideas and to communicate in the languages of disciplines other than their own.

Biology↗
PubMed2003

Objectively measured intensity of physical activity and adiposity in middle-aged women.

OBJECTIVE: The aim of this study was to evaluate the relationship between objectively measured physical activity (ACT), particularly intensity of physical activity (iACT), and body fat percentage (BF%) in 278 middle-aged women. Secondary purposes were to ascertain the association between physical activity duration (dACT) and BF% and the extent to which potentially confounding factors, including total ACT, energy intake, body weight, and season of assessment, influenced the relationship between iACT and BF%. RESEARCH METHODS AND PROCEDURES: A cross-sectional design was used. Subjects were apparently healthy, 35 to 45 years old, premenopausal, nonsmokers, with BMIs < 30 kg/m2. Approximately 90 percent were white, 81% were married, and 37% were college graduates. ACT was assessed using Computer Science and Application accelerometers worn for 7 consecutive days. The accelerometers recorded movement continuously, and activity counts were collapsed into 10-minute epochs. Intensity was indexed using seven activity count cut-off points, and duration was based on the number of 10-minute epochs at each intensity level. BF% was assessed using multiple measurements in the Bod Pod. Energy intake was measured using 7-day weighed diet records during the same week subjects wore the accelerometers. RESULTS: BF% was strongly and inversely associated with iACT and dACT. Controlling for energy intake and body weight strengthened the relationships among iACT, dACT, and BF%. Control of total ACT weakened the association. DISCUSSION: Engaging in higher intensity and/or longer duration ACT is associated with lower BF% compared with lower intensity and/or shorter durations of activity.

Adipose Tissue↗
PubMed2003

Objectively measured physical activity in a representative sample of 3- to 4-year-old children.

OBJECTIVE: This study aimed to describe levels of physical activity in a representative sample of preschool children and to quantify tracking of activity over 1 year. RESEARCH METHODS AND PROCEDURES: Physical activity (mean accelerometry counts/minute) was assessed over 3 days using the Computer Science and Applications accelerometer in 3- to 4-year-old children (n = 104; 52 boys; mean age, 3.7 +/- 0.4 years). In 60 children (30 boys), measurements were repeated 1 year later. RESULTS: Mean total activity at baseline was 777 +/- 207 counts/minute in boys and 657 +/- 172 counts/minute for girls; this gender difference was significant (p < 0.001). In the cross-sectional analysis, total activity was significantly positively related to age (r = 0.37, p = 0.007). In the sample followed up for 1 year, mean total activity was 849 +/- 252. The longitudinal analysis confirmed that total physical activity increased over the 1-year period (paired Student's t test, p < 0.001). The tracking rank order correlation coefficient of total activity count over 1 year was r = 0.40 (p < 0.001). DISCUSSION: This study suggests that total activity increases during the preschool period in Scottish children and that gender differences in total activity are present early in life. Tracking of total activity was only modest, but adequate assessment of tracking requires methodological research aimed at elucidating the biological meaning of accelerometer output.

Body Height↗
PubMed2004

Relationship between physical activity and diet among African-American girls.

OBJECTIVE: To examine the cross-sectional relationships between physical activity and dietary behaviors among 8- to 10-year-old African-American girls. RESEARCH METHODS AND PROCEDURES: Two hundred ten 8- to 10-year-old African-American girls from four field centers participated. Computer Science and Applications (CSA) activity monitors were worn for 3 days. CSA data were expressed as mean CSA counts per minute, mean minutes of moderate to vigorous activity per day, and mean metabolic equivalents (METS) per minute. Two nonconsecutive 24-hour dietary recalls were analyzed for kilocalories; percent kilocalories from fat; daily servings of fruit, 100% fruit juice, and vegetables; sweetened beverages; and water consumption. Height and weight were measured, and information on household income, material possessions, and participant age were obtained. RESULTS: All three expressions of physical activity were significantly negatively associated with percentage calories from fat (r = -0.147 to -0.177, p < 0.01), and mean METS per minute were significantly positively associated with percentage calories from carbohydrate (r = 0.149, p < 0.05) after controlling for household income, material possessions, field center, and total caloric intake. Income was inversely associated with percentage calories from fat. DISCUSSION: Physical activity and dietary fat consumption were inversely related among African-American girls. Efforts to prevent obesity in preadolescent African-American girls should focus on increasing physical activity and lowering dietary fat consumption.

Black or African American↗
PubMed1999

Physical activity assessment with accelerometers.

OBJECTIVE: Evaluation of motion sensors, specifically accelerometers, as an objective tool for the assessment of physical activity in large populations, over periods long enough to be representative of normal daily life and with minimal discomfort to the subjects. METHOD: Review of validation studies of accelerometers with indirect calorimetry as a reference method. Accelerometers were commercially available one-axial accelerometers: Caltrac, Computer Science Application (CSA) accelerometer, Mini Motionlogger Actigraph; the tri-axial accelerometer Tritrac-R3 D; and an tri-axial accelerometer for movement registration (Tracmor) from our laboratory. RESULTS: There is no clear difference for correspondence between indirect calorimetry and accelerometer counts during level walking, whether one-axial or tri-axial and placed at the wrist, hip or low back. Sedentary activities are better reflected with a tri-axial accelerometer than with a one-axial accelerometer. Two accelerometers were validated in free living conditions with doubly labeled water. The highest correlation between accelerometer output and activity induced energy expenditure was found for Tracmor. CONCLUSIONS: From all accelerometers tested, the tri-axial accelerometer for movement registration is an objective method that can be used to distinguish differences in activity levels between individuals and assess the effect of interventions on physical activity within individuals.

Adolescent↗
PubMed2004

Objectively measured physical activity correlates with indices of insulin resistance in Danish children. The European Youth Heart Study (EYHS).

OBJECTIVE: To explore the association between measures of insulin resistance with objectively assessed physical activity. DESIGN: School-based, cross-sectional study. SUBJECTS: A randomly selected sample of 589 children (310 girls, 279 boys, mean (standard deviations, s.d.) age=9.7 (0.44) y, weight=33.6 (6.4) kg, height=1.39 (0.06) m) from Denmark. METHODS: Fasting blood samples were analysed for serum insulin and glucose. Physical activity was measured with the uniaxial Computer Science and Applications (CSA) model 7164 accelerometer, worn for at least 3 days (>/=10 h day(-1)). Adiposity was assessed by the sum of four skinfolds. Multiple linear regression were performed to model insulin and glucose from average CSA output, adjusted for age, gender, puberty, ethnicity, birth weight, parental smoking, socioeconomic group, and CSA unit. In addition, we adjusted for skinfold thickness. RESULTS: Mean fasting serum glucose ranged from 4.1 to 6.5 mmol l(-1) with a mean (s.d.) of 5.1 (0.37) mmol l(-1). Fasting insulin was negatively correlated with CSA output on levels of adjustment. Fasting glucose was not significantly associated with physical activity. However, in girls both indices of insulin resistance were significantly related to activity, whereas in boys none of the associations were significant. CONCLUSION: Physical activity is inversely associated with fasting insulin in the nondiabetic range of fasting glucose. The relationship was stronger for insulin than for glucose, indicating compensatory action by the beta cells. Our data emphasise the importance of physical activity in children for the maintenance of metabolic control.

Biomarkers↗
PubMed2006

Methodological challenges in constructing effective treatment sequences for chronic psychiatric disorders.

Psychiatric disorders are often chronic conditions that require sequential decision making to achieve the best clinical outcomes. Sequential decisions are necessary to accommodate treatment response heterogeneity, a variable course of illness, and the often heavy burden associated with intensive or longer-term treatment. Yet, only a few studies in this field have been designed to address sequential decisions. Most of the experimental designs and data analytic methods that are best suited for improving sequential clinical decision making are often found in nonmedical fields such as engineering, computer science, and statistics. Promising designs and methods are surveyed with a focus on those areas most immediately useful for informing clinical decision making.

Chronic Disease↗
PubMed2002

An introduction to information retrieval: applications in genomics.

Information retrieval (IR) is the field of computer science that deals with the processing of documents containing free text, so that they can be rapidly retrieved based on keywords specified in a user's query. IR technology is the basis of Web-based search engines, and plays a vital role in biomedical research, because it is the foundation of software that supports literature search. Documents can be indexed by both the words they contain, as well as the concepts that can be matched to domain-specific thesauri; concept matching, however, poses several practical difficulties that make it unsuitable for use by itself. This article provides an introduction to IR and summarizes various applications of IR and related technologies to genomics.

Animals↗
PubMed2006

Microtechnology: meet neurobiology.

The field of neuroscience has always been attractive to engineers. Neurons and their connections, like tiny circuit elements, process and transmit information in a dramatic way that is intimately curious to researchers in the computer science and engineering fields. Of particular interest has been the recent push in applying microtechnology to the field of neuroscience. This review is meant to provide an overview of some of the subtle nuances of the nervous system and outline recent advances in lab on a chip applications in neurobiology. It also aims to highlight some of the challenges the field faces in the hopes of encouraging new engineering researchers to collaborate with neurobiologists to help advance our basic understanding of the nervous system and create novel applications based on neuroengineering principles.

Animals↗
PubMed2005

[Claude Fortier: the great history of neuroendocrinology].

The work of Claude Fortier is linked to the history of neuroendocrinology. Through him and his pioneer work in Montreal with Hans Selye, the << Man of stress >>, and at Laval University in Quebec City in his own laboratory, where all researchers involved in the study of the hypothalamo-hypophysial adrenal axis have been through, it is the whole saga of the search for the neuropeptide CRH (corticotropin releasing factor), and the harsh fight for the Nobel distinction that can be related. Among Claude Fortier's scientific discoveries, the feedback mechanisms of glucocorticoid hormones on brain and pituitary function, the presence of both mineralo and glucocorticoid receptors in some brain structures, and the introduction of computer science in biomedical research, can be cited. The consequences of these discoveries are illustrated in the pathologies linked to stress (anxiety, depression, addiction). Claude Fortier was not only a great figure in biomedical science, honored by several distinctions, but also an important personality in the policy of research in which he played a prominent role in Quebec medical research and allowed it to rank among the best in the world.

History, 20th Century↗