940 resultados para medical image segmentation
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An important segmentation basis used by firms is related to consumers` personal values which are investigated in this study. It was used a descriptive research with the survey method of data collection in a sample of executives from Sao Paulo who are considered to be potential buyers of high value and innovative goods. An exploratory factor analysis was employed in order to reduce the values scale used and a cluster analysis was performed to identify the groups of executives according to the importance attached to different person values. Concluding, it was observed that there was a similarity among the three personal values dimensions, named as Civility (concerns about having a good conduct before society according to social rules of interaction), Self-Direction (intellectual aspects and practical orientation in their conducts) and Conformity (restriction of actions, inclinations and impulses, that are likely to harm others and would violate expectations) and the ones reported in the theory Rokeach`s theory about instrumental personal values. Furthermore, three groups of executives were identified (good conduct group, low restriction group and high restriction group). The differences observed in the importance of personal values here presented by the dimensions called Civility, Self-Direction and Conformity can lead to different buying behaviors and product preferences. From the results found in this study the companies could adapt their current and new products offers, as well as their communication in order to better serve these segments of executives from Sao Paulo.
Targeted! Population segmentation, electronic surveillance and governing the unemployed in Australia
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Targeting is increasingly used to manage people. It operates by segmenting populations and providing different levels of opportunities and services to these groups. Each group is subject to different levels of surveillance and scrutiny. This article examines the deployment of targeting in Australian social security. Three case studies of targeting are presented in Australia's management of benefit overpayment and fraud, the distribution of employment services and the application of workfare. In conceptualizing surveillance as governance, the analysis examines the rationalities, technologies and practices that make targeting thinkable, practicable and achievable. In the case studies, targeting is variously conceptualized and justified by calculative risk discourses, moral discourses of obligation and notions of welfare dependency Advanced information technologies are also seen as particularly important in giving rise to the capacity to think about and act on population segments.
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Background: Over-ventilation causing low arterial carbon dioxide levels (PaCO2) has been associated with the development of neonatal chronic lung disease and adverse outcomes. This may occur very soon after birth. Aim: To investigate the effect on PaCO2 and oxygenation of very premature lambs resuscitated with different tidal volumes and PEEP. Methods: Anaesthetised lambs delivered at 126 days gestation were randomised to 15 min resuscitation with 3 regimes: (1) Laerdal resuscitation bag (B) with 100% oxygen and no PEEP, (2) fixed tidal volume (VT) of 5 mL/kg, or (3) VT of 10 mL/kg, both delivered with a Babylog 8000 ventilator in volume guarantee mode with 8 cm H2O PEEP and variable FiO2. Frequent blood gases were measured and VT, mean airway pressure (Paw), minute volume (MV), ventilation rate (VR), respiratory system compliance (Crs) and alveolar/arterial oxygen difference (AaDO2) were recorded. Results: Twenty lambs were studied. B (1) was associated with more variable VT and peak inspiratory pressures (PIP) compared to fixed tidal volumes (2 and 3). The lambs ventilated with 10 mL/kg were over-ventilated, those ventilated with 5 mL/kg were slightly under-ventilated. Those ventilated with the Laerdal bag had a mean VT of 7.5 mL/kg and were normocarbic. The different tidal volumes had little effect on oxygenation. PEEP improved oxygenation. The table shows the values at 15 minutes expressed as mean and SEM. TABLE. No caption av... TABLE. No caption av... Image Tools Conclusion: Very premature lambs can be effectively resuscitated from birth using volume guarantee ventilation. Within minutes of birth different tidal volumes had a large effect on PaCO2 and no effect on oxygenation. Studies are needed to determine the appropriate tidal volume for resuscitating very premature infants to maintain acceptable levels of PaCO2. © International Pediatrics Research Foundation, Inc. 2004. All Rights Reserved.
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This paper describes algorithms that can identify patterns of brain structure and function associated with Alzheimer's disease, schizophrenia, normal aging, and abnormal brain development based on imaging data collected in large human populations. Extraordinary information can be discovered with these techniques: dynamic brain maps reveal how the brain grows in childhood, how it changes in disease, and how it responds to medication. Genetic brain maps can reveal genetic influences on brain structure, shedding light on the nature-nurture debate, and the mechanisms underlying inherited neurobehavioral disorders. Recently, we created time-lapse movies of brain structure for a variety of diseases. These identify complex, shifting patterns of brain structural deficits, revealing where, and at what rate, the path of brain deterioration in illness deviates from normal. Statistical criteria can then identify situations in which these changes are abnormally accelerated, or when medication or other interventions slow them. In this paper, we focus on describing our approaches to map structural changes in the cortex. These methods have already been used to reveal the profile of brain anomalies in studies of dementia, epilepsy, depression, childhood and adult-onset schizophrenia, bipolar disorder, attention-deficit/ hyperactivity disorder, fetal alcohol syndrome, Tourette syndrome, Williams syndrome, and in methamphetamine abusers. Specifically, we describe an image analysis pipeline known as cortical pattern matching that helps compare and pool cortical data over time and across subjects. Statistics are then defined to identify brain structural differences between groups, including localized alterations in cortical thickness, gray matter density (GMD), and asymmetries in cortical organization. Subtle features, not seen in individual brain scans, often emerge when population-based brain data are averaged in this way. Illustrative examples are presented to show the profound effects of development and various diseases on the human cortex. Dynamically spreading waves of gray matter loss are tracked in dementia and schizophrenia, and these sequences are related to normally occurring changes in healthy subjects of various ages. (C) 2004 Published by Elsevier Inc.
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Techniques applying digital images increasingly have been used in biology, medicine, physics, and other research areas. The image coordinates can represent light intensities values to be detected by a CCD. Based on this concept, a photometric system composed of a LED source and a digital camera as a detector was used for optical density measurements. Standards for permanganate, glucose, and protein solutions were detemined by colorimetric methods using our device. Samples of protein of Pasteurella mutocida bacteria membrane and, also, fractions of rabbit kidney membrane, rich in Na, K-ATPase, with unknown concentrations were dosed through the Hartree method using our photometric system.
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Objective: To determine whether routine electronic records are an accurate source of population health data in general practice through reviewing cervical smears rates in four South Australian practices. Methods: The cervical screening rate in a purposive sample of four general practices (three rural and one urban) was obtained using an audit of medical records and a telephone follow-up. Results: The cervical screening rate using only immediately available electronic medical records indicated an overall low rate for the participating practices (44.9%). However, telephone follow-up and adjustments to the denominator indicated the real rate to be 85.7%. The offer of appointments during the telephone follow-up further improved this rate for eligible women (93.8%). Conclusions and implications: Electronic medical records may be inadequate in preventive screening in general practice, without ensuring their accuracy. Updating records by telephone or personal follow-up produces a much more accurate denominator.
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What different forms of engagement do image and text allow the spectator/reader? We know that text and image communicate, and that all communication depends on a relationship between those who communicate. The objective of this text is therefore to understand the new possibilities available to an anthropology of the expression of knowledge that makes use of images, such as photographs and films.
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Purpose: To evaluate wavefront performance and modulation transfer function (MTF) in the human eye aft er the implantation of diffractive or refractive multifocal intraocular lenses (IOLs). Materials and Methods: This was a prospective, interventional, comparative, nonrandomized clinical study. Uncorrected distance and near visual acuity, and wavefront analysis including MTF curves (iTrace aberrometer, Tracey Technologies, Houston, TX, USA) were measured in 60 patients aft er bilateral IOL implantation with 6 months of follow-up. Forty eyes received the diffractive ReSTOR (Alcon), 40 eyes received the refractive ReZoom (Advanced Medical Optics) and 40 eyes, the Tecnis ZM900 (Advanced Medical Optics). The comparison of MTF and aberration between the intraocular lenses was performed using analysis of variance (ANOVA), followed by the Dunn test when necessary. Results: The mean uncorrected distance visual acuity was similar in all three groups of multifocal IOLs. The ReSTOR group provided better uncorrected near visual acuity than the ReZoom group (P < 0.001), but similar to the Tecnis group. Spherical aberration was significantly higher in the ReZoom group (P = 0.007). Similar MTF curves were found for the aspheric multifocal IOL Tecnis and the spheric multifocal IOL ReSTOR, and both performed better than the multifocal IOL ReZoom in a 5 mm pupil (P < 0.001 at all spatial frequencies). Conclusions: Diffractive IOLs studied presented similar MTF curves for a 5 mm pupil diameter. Both diffractive IOLs showed similar spherical aberration, which was significantly better with the full-diffractive IOL Tecnis than with the refractive IOL ReZoom.
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Background: Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years` duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown. Objective: To describe the experience of obesity pharmacotherapy in the elderly in a specialized obesity care setting in Brazil, with a focus on efficacy and safety. Methods: A retrospective evaluation was conducted on medical charts from an outpatient clinic of a specialized tertiary centre for the treatment of obesity. We included patients who had had at least one consultation between January and December 2007, were aged >= 60 years at the beginning of the treatment, had had at least 6 months of follow-up and had received a prescription of at least one potential weight-loss drug. Diagnoses reported on medical records were documented. Age, weight, height and body mass index (BMI) were recorded at admission, after 6, 12, 18 and 24 months, and at the last available visit. The medicines prescribed, together with the dose, duration of use, adverse effects and reasons for discontinuation, were documented. Results: The group consisted of 44 women (86%) and 7 men (14%), with a mean +/- SD age of 65.2 +/- 4.5 years, weight of 95.3 +/- 12.5 kg and BMI of 38.5 +/- 4.3 kg/m(2). The mean +/- SD time of follow-up was 39.3 +/- 26.4 months, and the mean weight loss was 6.65 kg (p < 0.01). After the first 6 months, the mean +/- SD weight loss was 5.7 +/- 3.8 kg (p < 0.0001). A smaller weight loss was seen between the 6th and 12th months, with no statistically significant change in weight thereafter. A weight loss of >= 5% was achieved by 64.71%, 63.64%, 62.16% and 69.70% in the 6th, 12th, 18th and 24th months, respectively, and a weight loss of >= 10% was achieved by 17.65%, 34.09%, 32.43% and 39.39% in the 6th, 12th, 18th and 24th months, respectively. The medicines prescribed were sibutramine, orlistat, fluoxetine, sertraline, topiramate, fenproporex, mazindol and amfepramone, alone or in combinations, concomitantly or sequentially. The reasons for discontinuation were lack of response (n = 13), loss of response (development of tolerance) [n= 11], lack of adherence (n = 14) and adverse effects (n= 14). One episode of atrial flutter occurred in a patient taking fenproporex. The weight-loss medications were generally well tolerated, and only transient adverse events were reported. Conclusions: Long-term pharmacotherapy for obesity was effective and well tolerated by this group of elderly patients.
Resumo:
The Australian National Medical Education Colloquium provided a productive forum for medical educators to meet and to discuss and debate important contemporary issues affecting Australian medical schools. None of us know what the future will hold, and some of the possibilities discussed at the Colloquium were futuristic indeed. We would be wise to keep an open mind, to focus very much on competence and fitness to practice, and to develop a strong evidence base, as we travel this important path.