| 1. |
- Karlsson, Bengt, et al.
(författare)
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Thyroid dysfunction in Down's syndrome : relation to age and thyroid autoimmunity
- 1998
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Ingår i: Archives of Disease in Childhood. - 0003-9888 .- 1468-2044. ; 79:3, s. 242-245
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The prevalence of thyroid disease is increased in Down's syndrome. Most available data come from cross sectional studies. AIMS: To study longitudinally thyroid function in patients with Down's syndrome in Uppsala county (85 patients) up to the age of 25 years. METHODS: Observational study based on yearly follow up in a children's clinic. Thyroid function tests were performed at each visit to the clinic. RESULTS: Hypothyroidism was found in 30 and hyperthyroidism was found in two of the 85 patients. No sex difference was seen. Half of the patients with hypothyroidism acquired the condition before the age of 8 years, but only one of them displayed thyroid autoantibodies at diagnosis. Most patients who developed hypothyroidism after this age had thyroid autoantibodies. In the prepubertal patients with hypothyroidism, growth velocity was lower during the year before the start of thyroxine treatment than during the year after treatment began; it was also lower than that of sex and age matched euthyroidic children with Down's syndrome. CONCLUSION: Thyroid dysfunction in patients with Down's syndrome is common in childhood. Consequently, annual screening is important. Autoimmune thyroid disease is uncommon in young children with Down's syndrome but is common after 8 years of age.
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| 2. |
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| 3. |
- Berggren, Ulf, 1948, et al.
(författare)
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Factor analysis and reduction of a Fear Survey Schedule among dental phobic patients.
- 1995
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Ingår i: European journal of oral sciences. - 0909-8836 .- 1600-0722. ; 103:5, s. 331-8
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Tidskriftsartikel (refereegranskat)abstract
- A fear survey instrument, based on the Fear Survey Schedule-II and five additional fear items, was administered to 109 patients (70 women and 39 men) on a waiting list at a specialized dental fear clinic. The fear survey was analyzed to identify its factorial structure. Five fear factors, explaining 54% of the total variance, were identified concerning areas of "illness and death", "failures and embarrassment", "social situations", "physical injuries", and "animals and natural phenomena". An ad hoc reduction of items was carried out to form a shorter, more practical to use questionnaire, which resulted in factors of four or five items with loadings greater than 0.50. The factors intercorrelated significantly (rp varying between 0.33 and 0.59) and "illness and death" correlated highly with "physical injuries" (rp = 0.59) and "animals and natural phenomena" (rp = 0.56), while "failures and embarrassment" correlated highly to "social situations" (rp = 0.54). Statistically significant, but generally lower correlations were found between each factor and the dental fear measures. The highest correlations were found between fear of "physical injuries" and dental fear. There was also a high and significant correlation between sex and fear of "animals and natural phenomena".
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| 6. |
- Gustafsson, Fredrik, et al.
(författare)
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Change Detection Design for Low False Alarm Rates
- 1997
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Ingår i: Proceedings of the SAFEPROCESS'97 Conference on Fault Detection, Supervision and Safety for Technical Processes. - 0080423817
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Konferensbidrag (refereegranskat)abstract
- This contribution addresses the problem of automated tuning of change detectors with given false alarm rate. By estimating a parametric distribution to the test statistics computed from real or simulated data, the threshold of the test can be computed directly. The advantage is that we can predict the threshold although there are no or very few false alarms in the used data. Using real data, the method is robust to assumed noise distributions and modeling errors. We illustrate the method on the CUSUM and GLR tests applied to friction estimation in cars and an airborne navigation system, respectively.
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| 7. |
- Gustafsson, Leif, et al.
(författare)
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International incidence rates of invasive cervical cancer after introduction of cytological screening
- 1997
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Ingår i: Cancer Causes and Control. - 0957-5243 .- 1573-7225. ; 8:5, s. 755-763
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Tidskriftsartikel (refereegranskat)abstract
- Because Pap-smear screening can detect pre-invasive cervical cancer, such screening can markedly reduce the occurrence of invasive cancer. However, its impact in different populations is uncertain. This study compares the changes in cervical cancer incidence at different ages after the introduction of screening in different populations, and addresses the impact of organized and opportunistic smear taking. We identified 17 cancer registries large enough and existing long enough to analyze screening effects. For each registry, we calculated the relative reduction in age-specific incidence rates and in incidence rates age-standardized to the world population after the introduction of cytologic screening. In 11 of the 17 populations, age-standardized incidence rates declined markedly from 27 percent in Norway and to 77 percent in Finland. Age-specific declines were confined to women aged 30 to 70 years old with a nadir around ages 40 to 55. In six other populations, age-standardized incidence rates declined less than 25 percent, an amount too small to provide unambiguous evidence of a screening effect. In several populations, cytologic screening had a more pronounced effect than is generally recognized. Because age-specific declines in cervical cancer incidence rates were strikingly similar in populations with widely different screening practices, organized screening may not be markedly superior to opportunistic screening. The reduction in reported cancer incidence because of screening is smaller in younger and older women.
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| 8. |
- Gustafsson, Leif, et al.
(författare)
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International incidence rates of invasive cervical cancer before cytological screening
- 1997
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Ingår i: International Journal of Cancer. - 0020-7136 .- 1097-0215. ; 71:2, s. 159-165
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Tidskriftsartikel (refereegranskat)abstract
- Huge differences in incidence rates of invasive cervical cancer occur among populations. These differences reflect the influences of both etiological environmental factors and removal of precursor lesions detected upon screening. The purposes of this article are (i) to describe similarities and differences in the shapes and magnitudes of age-specific incidence rates of invasive cervical cancer before screening had an effect, (ii) to provide baseline data for further global study of screening effects, and (iii) to provide baseline incidence data for the design of optimal screening programs. To eliminate the impact of screening effects, we have selected age-specific incidence rates from times when and from populations in which screening was insignificant. The selected rates were suitably scaled and compared regarding age at onset of increase in incidence, age at peak incidence, and rate of subsequent decline. Despite a 16-fold difference in incidence rates, all curves had the same basic structure, with an increase to a peak followed by a decline or a plateau. Although all populations but one had an onset around age 25, 7 European countries showed an earlier peak age (mean = 46 vs. 59) and a more rapid decline after the peak than most other populations. The common basic shape of the age-specific incidence curve, overall, suggests a relatively similar development of invasive cervical cancer in different populations. These results illustrate the underlying similarities in the markedly different age-specific incidence rates of invasive cervical cancer. They also provide a basis for studying screening effects and for optimizing screening programs in specific geographic areas.
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| 9. |
- Haan, Jan Mark de, et al.
(författare)
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Spectral Subtraction Using Model-based Spectra
- 1999
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Konferensbidrag (refereegranskat)abstract
- When using a mobile phone with a handsfree equipment in a vehicle it is difficult to have a relaxed conversation due to the high noise level. The noisy environment gives raise to a poor signal to noise ratio since the handsfree microphone picks up the background noise as well as the speech. By using speech enhancement processing, the quality of the conversation will be enhanced. This paper introduces a speech enhancement algorithm based on the spectral subtraction method. The method uses estimates of the noise spectrum and the noisy speech spectrum to form an SNR-based gain function, which is used for filtering the microphone signal. There are two different classes of spectrum estimation techniques non-parametric and parametric. Parametric estimation methods are based on a model of the underlying signal in order to estimate the spectrum.Furthermore a tool for assessing the accuracy of the estimations in situations when few data is available is applied, known as the bootstrapmethod. The spectral subtraction method, combined with different spectrum estimation techniques, are evaluated using real-world signals recorded in a car.
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| 10. |
- Hagenbjörk-Gustafsson, Annika, 1956-, et al.
(författare)
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Validation of a diffusive sampler for NO2
- 1999
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Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry. - 1464-0325 .- 1464-0333. ; 1, s. 349-352
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Tidskriftsartikel (refereegranskat)abstract
- A diffusive sampler for NO2, Willems badge, was validated in laboratory experiments and field tests. The collecting reagent for NO2 in the sampler is triethanolamine, and the analysis is based on a modified colorimetric method, theSaltzman method. The analysis was performed by a flow injection analysis (FIA) technique. The sampling rate for the sampler was determined to be 40.0 ml min−1. There was no effect of NO2 concentration or relative humidity on sampling rate, and the influence of sampling time was found to be small. The detection limit was 4 mg m−3 for a 24 hsample. The capacity is high enough to allow sampling of 150 mg m−3 for 7 days, which is twice the recommended Swedish short-term (24 h) guideline value as a 98-percentile over 6 months. In field tests, the sampler performedwell, even at wind speeds higher than 2 m s−1, and at low temperatures. The overall uncertainty of the method was 24%. The sensitivity and capacity of the method also make it suitable for personal sampling for 2–8 h in working environments.
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