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The weight-conscious adolescent: body image, food intake, and weight-related behavior.

PURPOSE: To explore how adolescents who try to lose weight differ from those who do not in relation to body image, food intake, knowledge about food, and sources of information about food, nutrition, and weight loss. METHODS: Data were collected from 12-15-year-old school students in North Queensland, Australia by questionnaire. RESULTS: Boys who attempted weight loss reduced sweet foods and snacks, while concurrently increasing healthy foods such as fruit, yogurt, and low-fat milk. Girls who attempted weight loss ate breakfast, lunch, snacks, milk, bread, meat, and many sweet and fatty foods less often than other girls. Some reduction in meals, snacks, core foods, and sweet fatty foods, but not savory fatty foods, remained after the weight loss attempt. Boys attempting weight loss had better knowledge about high-fat and high-sugar foods than other boys, but there was no difference for girls. Girls attempting weight loss were more likely than other girls to think that core foods such as bread, potatoes, and dairy products should be reduced, whereas boys were more likely to think that sweet foods should be reduced. The majority of students who had attempted weight loss during the previous year considered themselves overweight, while few weight-conscious students were satisfied with their bodies. CONCLUSIONS: The weight-conscious adolescents in this study, especially the girls, exhibited restrictive eating practices and a preoccupation with a slim image. Adolescents need a food culture based on foods to eat rather than foods to avoid, and an understanding of suitable weight-control measures.

Adolescent↗

Presidential address 1998. In search of daylight.

Practising medicine in Canada has become increasingly bureaucratic, confrontational and stressful. The Canadian Orthopaedic Association must take a far more proactive role in the development of orthopedic surgeons as professionals and in the political environment in which they practise. Living in a "knowledge-rich workplace" orthopedic surgeons must support continuous professional development and provide leadership and incentive to maintain competence in their profession. The "baby boomers" are coming. Their numbers will have a profound effect on the practice of orthopedic surgery, not 20 or 30 years from now but within the next 10 years. Therefore it is imperative that orthopedic surgeons assess and accept the impact that the "boomers" will have on surgeons, hospital beds and operating-room time. Orthopedic surgeons and the Canadian Orthopaedic Association are challenged by a new role as vendors of information in a new "information age" economy, whose fundamental sources of wealth are knowledge and communication.

Canada↗

Publication bias in foodborne outbreaks of infectious intestinal disease and its implications for evidence-based food policy. England and Wales 1992-2003.

Systematic national surveillance of outbreaks of infectious intestinal disease (IID) was introduced in England and Wales in 1992 to provide comprehensive information on causative organisms, sources or vehicles of infection and modes of transmission. We compared information from this system with that published in the peer-reviewed literature between 1 January 1992 and 31 January 2003 to assess the potential effect of publication bias on food-safety policy. During the study period 1763 foodborne outbreaks of IID were reported to national surveillance. Fifty-five were published in the peer-reviewed literature. The peer-reviewed literature overestimated the impacts of milk/milk products, miscellaneous foods (e.g. sandwiches) and desserts and underestimated those of poultry, fish and shellfish, red meat/meat products and eggs/egg products. Without systematic surveillance, knowledge of causative organisms, sources or vehicles of infection and modes of transmission, as gleaned from the peer-reviewed literature, would potentially distort food-safety policy.

Animals↗

Survey of pediatric hospitals' preparation programs: evidence of the impact of health psychology research.

A survey of all 123 nonchronic-care pediatric hospitals in the United States revealed that 75% of hospitals responding had greatly increased the use of effective medical procedure preparation technologies, such as filmed modeling and coping skills instruction, in comparison to the last survey. Respondent characteristics such as position (e.g., nurse, child life worker, physician), degree (e.g., RN, MA, PhD), and length of time in the position failed to predict the type of techniques selected, but higher respondent knowledge and more psychological sources of preparation information did predict the use of preparation techniques used for drawing blood that experts rated as more effective. Challenges for more effective dissemination of research in the future are considered, as is the need for increased study of research-implementation links.

Analysis of Variance↗

Racial differences in breast cancer screening, knowledge and compliance.

BACKGROUND: Breast cancer is the second leading cause of cancer death among women in the United States. Although the incidence of breast cancer is 13% higher in white women, mortality in black women is 28% higher, due to histological and socioeconomic factors. Existing research regarding racial differences in compliance with breast cancer screening recommendations has found conflicting results. METHODS: Data on more than 4,500 women were taken from the 1992 National Health Interview Survey, a nationally representative, population-based sample survey. Logistic regression was used to estimate the relative odds of knowledge of breast self-exam (BSE) and mammograms, and compliance with BSE, clinical breast exams (CBE), and mammograms. RESULTS: Black women were less likely than white women to be aware of and use breast cancer screening tests. However, among women who were aware of screening tests, compliance was higher among black women. Women with low educational attainment, low cancer knowledge, and no usual source of care were less likely to be CBE or mammogram compliant. Socioeconomic differences were larger for the two clinical tests than for BSE. CONCLUSIONS: Programs should inform women about cancer screening tests and remove barriers that hinder women from receiving clinical screening exams.

Adult↗

Aromatic metabolism versus carbon availability: the regulatory network that controls catabolism of less-preferred carbon sources in Escherichia coli.

The current knowledge on the genetics and biochemistry of the catabolism of aromatic compounds in Escherichia coli settles the basis to consider these pathways as a model system to study the complex molecular mechanisms that control the expression of the genes involved in the metabolism of less-preferred carbon sources in this paradigmatic organism. Two different levels of regulation are reviewed: (i) the specific regulatory mechanisms that drive the expression of the catabolic genes when the cognate inducer, i.e., the substrate of the pathway or an intermediate metabolite, is available, and (ii) the global or superimposed regulation that adjust the expression of the catabolic clusters to the general physiological status of the cell.

Adaptation, Physiological↗

Young children's (Homo sapiens) understanding of knowledge formation in themselves and others.

Three- and 4-year-old children (Homo sapiens) were tested for comprehension of knowledge formation. In Experiment 1, 34 subjects watched as a surprise was hidden under 1 of 4 obscured cups. The experimenter then pointed to the cup. All children searched under the correct cup, but no 3-year-olds (in contrast to most 4-year-olds) could explain how they knew where to look. Subjects then discriminated between simultaneous pointing by 2 adults, one who had hidden a surprise and one who had left the room before the surprise was hidden. Most 4-year-olds (but no 3-year-olds) showed clear discrimination between the adults. In Experiment 2, 16 subjects were tested with procedures designed to make the source of their own knowledge more obvious, but this had no effect on performance. We conclude that studies using very similar procedures with chimpanzees and rhesus macaques were measuring an ability (or inability) to understand how knowledge states form.

Child Development↗

Re-examining hypotheses concerning the use and knowledge of medicinal plants: a study in the Caatinga vegetation of NE Brazil.

BACKGROUND: The Caatinga (dry land vegetation) is one of the most characteristic vegetation types in northeastern Brazil. It occupies a large percentage of the semi-arid region there, and generally supports two major types of economic activity: seasonal agriculture and the harvesting of plant products. However, very little information is available concerning the interaction of people with the plants of the Caatinga. METHODS: A study was undertaken with the participation of 31 adults from a rural community in the state of Pernambuco, Brazil, in order to analyze the patterns of use of medicinal plant resources, and to test a number of hypotheses concerning their use and local knowledge about them. The sources of medicinal plants used by the local community, the differences in oral information concerning the use of plants with their effective uses, and the role of exotic plants in local folk medicine practices were examined. RESULTS: Forty-eight plant species were cited as having medicinal uses, of which 56.25% are native to the Caatinga region. The patterns of harvesting and the importance of these trees and shrubs as medicinal plants seem to be compatible with a hypothesis based on the seasonal availability of plant resources. There is no direct correlation between known medicinal plants and those used by the local population, which agrees with observations made in different tropical regions. However, this observation was not interpreted in terms of the idea of "erosion" of knowledge (commonly used to explain this lack of correlation), but rather to propose two new concepts: "mass knowledge" and "stock knowledge". CONCLUSION: Native plants are a very significant component of locally used medicinal plants, although exotic plants are important for treating specific health problems--which leads the proposal of a hypothesis of diversification.

Adult↗

Bayesian solutions and performance analysis in bioelectric inverse problems.

In bioelectric inverse problems, one seeks to recover bioelectric sources from remote measurements using a mathematical model that relates the sources to the measurements. Due to attenuation and spatial smoothing in the medium between the sources and the measurements, bioelectric inverse problems are generally ill-posed. Bayesian methodology has received increasing attention recently to combat this ill-posedness, since it offers a general formulation of regularization constraints and additionally provides statistical performance analysis tools. These tools include the estimation error covariance and the marginal probability density of the measurements (known as the "evidence") that allow one to predictively quantify and compare experimental designs. These performance analysis tools have been previously applied in inverse electroencephalography and magnetoencephalography, but only in relatively simple scenarios. The main motivation here was to extend the utility of Bayesian estimation techniques and performance analysis tools in bioelectric inverse problems, with a particular focus on electrocardiography. In a simulation study we first investigated whether Bayesian error covariance, computed without knowledge of the true sources and based on instead statistical assumptions, accurately predicted the actual reconstruction error. Our study showed that error variance was a reasonably reliable qualitative and quantitative predictor of estimation performance even when there was error in the prior model. We also examined whether the evidence statistic accurately predicted relative estimation performance when distinct priors were used. In a simple scenario our results support the hypothesis that the prior model that maximizes the evidence is a good choice for inverse reconstructions.

Algorithms↗

Broadband attenuation and nonlinear propagation in biological fluids: an experimental facility and measurements.

The design and construction of a versatile experimental facility for making measurements of the frequency-dependence of attenuation coefficient (over the range 1 MHz to 25 MHz) and nonlinear propagation in samples of biological fluids is described. The main feature of the facility is the ability to perform all of the measurements on the same sample of fluid within a short period of time and under temperature control. In particular, the facility allows the axial development of nonlinear waveform distortion to be measured with a wideband bilaminar polyvinylidene difluoride membrane hydrophone to study nonlinear propagation in biological fluids. The system uses a variable length bellows to contain the fluid, with transparent Mylar end-windows to couple the acoustic field into the fluid. Example results for the frequency-dependence of attenuation of Dow Corning 200/350 silicone fluid, used as a standard fluid, are presented and shown to be in good agreement with alternative measurements. Measurements of finite amplitude propagation in amniotic fluid, urine and 4.5% human albumin solutions at physiological temperature (37 degrees C) are presented and compared with theoretical predictions using existing models. The measurements were made using a 2.25-MHz single-element transducer coupled to a polymethyl methacrylate lens with a focal amplitude gain of 12 in water. The transducer was driven with an eight-cycle tone burst at source pressures up to 0.137 MPa. In general, given an accurate knowledge of the medium parameters and source conditions, the agreement with theoretical prediction is good for the first five harmonics.

Animals↗

EEG source localization: implementing the spatio-temporal decomposition approach.

OBJECTIVES: The spatio-temporal decomposition (STD) approach was used to localize the sources of simulated electroencephalograms (EEGs) to gain experience with the approach for analyzing real data. METHODS: The STD approach used is similar to the multiple signal classification method (MUSIC) in that it requires the signal subspace containing the sources of interest to be isolated in the EEG measurement space. It is different from MUSIC in that it allows more general methods of spatio-temporal decomposition to be used that may be better suited to the background EEG. RESULTS: If the EEG data matrix is not corrupted by noise, the STD approach can be used to locate multiple dipole sources of the EEG one at a time without a priori knowledge of the number of active sources in the signal space. In addition, the common-spatial-patterns method of spatio-temporal decomposition is superior to the eigenvector decomposition for localizing activity that is ictal in nature. CONCLUSIONS: The STD approach appears to be able to provide a means of localizing the equivalent dipole sources of realistic brain sources and that, even under difficult noise conditions and only 2 or 3 s of available EEG, the precision of the localization can be as low as a few mm.

Artifacts↗

Teenagers' knowledge of human sexuality and their views on teenage pregnancies.

There is concern about poor knowledge of human sexuality and a high rate of teenage pregnancies among Blacks. The primary aim of the study was to measure the knowledge that teenagers have on human sexuality and to identify the sources from which they obtain such knowledge. The secondary aim was to detect how teenagers perceive the teenage pregnancy problem and its consequences. A descriptive study was undertaken. Questionnaires were handed out and collected from 210 teenagers in two Senior Secondary Schools at a Black township near Empangeni. The study revealed that teenagers have reasonable knowledge about the anatomy and development of the reproductive organs at puberty but lacked sex counselling which resulted in their failure to understand the implications of sexual behaviour. The levels of knowledge an utilisation of the Youth Health Services was found to be low. The study also revealed a high level of awareness of the negative consequences of teenage pregnancies. The teenagers had numerous suggestions to make for the prevention of teenage pregnancies.

Adolescent↗

A knowledge management framework to morph clinical cases with clinical practice guidelines.

In this paper we present a knowledge management framework that allows the automatic linking/mapping of contextually and functionally similar medical knowledge that may originate from different sources and be represented in diverse modalities. Our tacit-explicit knowledge morphing framework supports the extraction of tacit knowledge from past cases stored in a case-base and maps it to corresponding explicit knowledge stored in clinical practice guidelines. The novelty of our approach is inherent in the fact that it allows practitioners to simultaneously refer to explicit knowledge-i.e. clinical practice guidelines-and experiential knowledge-i.e. past clinical cases. Here we present the system design and intended functionality of our knowledge morphing framework.

Health Knowledge, Attitudes, Practice↗

Contraceptive knowledge, attitude and practices of men in rural Maharashtra.

Since men are the dominant decision makers in India, it is prudent to discover the knowledge, perception, attitudes and contraceptive practices of men to improve their involvement in the reproductive health needs of families. Three thousand and seventy-two married men from a tribal Primary Health Centre (PHC) area in Thane district of Maharashtra State, India were surveyed with special emphasis on investigating the reasons for not accepting male methods. The majority of them not only had no concept of family spacing, but had not even taken any initiative to improve their knowledge or acceptance of condom/ vasectomy. Men who were aware of contraceptive methods had little knowledge of their correct use. Of the men, 53.7% had positive views about their role in family planning while 66.2% of men stressed the need to improve the acceptance of male methods by providing knowledge and information through sources such as radio, television, door-to-door campaigning and interpersonal communications. Thirty per cent emphasized the need to improve the availability and quality of services. This study indicates a pressing need for effective intervention strategies, both at the community and the clinic level, backed with efficient counselling, motivation and provision of services in rural and remote areas.

Adolescent↗

Evaluation of mechanical precision and alignment uncertainties for an integrated CT/LINAC system.

A new integrated CT/LINAC combination, in which the CT scanner is inside the radiation therapy treatment room and the same patient couch is used for CT scanning and treatment (after a 180-degree couch rotation), should allow for accurate correction of interfractional setup errors. The purpose of this study was to evaluate the sources of uncertainties, and to measure the overall precision of this system. The following sources of uncertainty were identified: (1) the patient couch position on the LINAC side after a rotation, (2) the patient couch position on the CT side after a rotation, (3) the patient couch position as indicated by its digital readout, (4) the difference in couch sag between the CT and LINAC positions, (5) the precision of the CT coordinates, (6) the identification of fiducial markers from CT images, (7) the alignment of contours with structures in the CT images, and (8) the alignment with setup lasers. The largest single uncertainties (one standard deviation or 1 SD) were found in couch position on the CT side after a rotation (0.5 mm in the RL direction) and the alignment of contours with the CT images (0.4 mm in the SI direction). All other sources of uncertainty are less than 0.3 mm (1 SD). The overall precision of two setup protocols was investigated in a controlled phantom study. A protocol that relies heavily on the mechanical integrity of the system, and assumes a fixed relationship between the LINAC isocenter and the CT images, gave a predicted precision (1 SD) of 0.6, 0.7, and 0.6 mm in the SI, RL and AP directions, respectively. The second protocol reduces reliance on the mechanical precision of the total system, particularly the patient couch, by using radio-opaque fiducial markers to transfer the isocenter information from the LINAC side to the CT images. This protocol gave a slightly improved predicted precision of 0.5, 0.4, and 0.4 mm in the SI, RL and AP directions, respectively. The distribution of phantom position after CT-based correction confirmed these results. Knowledge of the individual sources of uncertainty will allow alternative setup protocols to be evaluated in the future without the need for significant additional measurements.

Artifacts↗

A study of the knowledge, attitude and practice (KAP) of a Saudi Arabian community towards the problem of brucellosis.

The present study included 337 patients, presenting to Asir Central Hospital with fever of more than two weeks duration, or symptoms associated with brucellosis but without fever. Of the 337 subjects examined for knowledge about methods and means of transmission of brucellosis, 309 (92%) were ignorant while only 28 (8%) appeared to possess some knowledge as to the source, type of animal contact and presentation of illness. None of the 337 subjects was able to link the disease with a microbial infection. The most important common practices associated with brucellosis included raw milk consumption, close animal contact and the slaughtering and disposal of wastes. Illiteracy, ignorance and faulty behaviours emphasize the importance of health education of the community, to raise the KAP standard of the full spectrum of brucellosis in the community would be valuable in its prevention and control.

Brucellosis↗

An overview of brominated flame retardants in the environment.

The presence of brominated flame retardant (BFR) chemicals, and particularly polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD), has become of increasing concern to scientists over the past decade. Environmental studies conducted primarily in Europe, Japan and North America indicate that these chemicals are ubiquitous in sediment and biota. The levels of PBDEs seem to be increasing, and several trends, including in humans, indicate that this increase may be rapid. The occurrence of high concentrations of certain PBDE isomers may be sufficient to elicit adverse effects in some wildlife. There is also concern that levels could cause adverse effects in sensitive human populations such as young children, indigenous peoples, and fish consumers. However, our knowledge about these chemicals, their sources, environmental behavior, and toxicity is limited, making risk assessment difficult. In this paper, the current state of knowledge is reviewed and areas for further research recommended to improve future monitoring and risk assessment efforts.

Animals↗

Teenagers' knowledge of the acquired immunodeficiency syndrome and associated risk behaviors.

Adolescents are now recognized as being at high risk for contracting the human immunodeficiency virus (HIV), the presumed cause of acquired immunodeficiency syndrome (AIDS). This article reports the findings of a survey that examined AIDS knowledge, risk behaviors, and informational sources for AIDS in a group of suburban New Jersey high school students (N = 152). This group had knowledge of HIV and its transmission, but results indicated that students also participated in behaviors considered "risky" for the transmission of HIV. These behaviors included unprotected sexual intercourse (40% of sexually active males) and sexual intercourse with multiple partners over a period of time (23% of sexually active males).

Acquired Immunodeficiency Syndrome↗