Juhani Rinne

Long-term results after surgical treatment of laryngeal stenosis in small children

Thirteen severe cases of laryngeal stenosis were operated on at the ages of 1-3 years. The operations were performed by making a laryngofissure in the front part of the larynx and excising the stenosing scar. The back wall of the larynx was incised in the midline and the two halves of the cricoid lamina were separated from each other. An indwelling prosthesis was placed in the larynx for 4 months. All patients but one were decannulated. The positive clinical result of the operation proved to be permanent through the rapid growth phase of puberty in 7 patients out of the 10 who had reached puberty. Three patients developed a gradually worsening laryngeal stenosis during the rapid growth phase of puberty. One of them was successfully re-operated. The mean follow-up time was 12 years. Ventilatory function tests were performed on 9 patients, 4 of which proved to have normal ventilatory function or only slight airflow limitation in central airways.

Inflammatory cell subpopulations in the middle ear mucosa of ears with effusion

Middle ear mucosal biopsies were taken from 11 patients with middle ear effusion. In 8 cases the specimens were sufficiently large to allow detailed studies of the submucosal cellular components. It appears that in noncomplicated serous middle ear effusion, due to mechanical obstruction of the Eustachian tube, the submucosa is not infiltrated by inflammatory cells. In all types of mucoid effusion of variable duration, various lymphocyte classes, i.e. T- and B-lymphocytes and plasma cells, were present, suggesting a normal cellular immune response. The lack of granulocytes seems to indicate that there is no submucosal infection.

Estimation of the Cressman Term for a Barotropic Model through Optimization with Use of the Adjoint Model

Abstract This paper presents an estimate of the Cressman term that appears in the divergent barotropic model as a corrector of planetary-wave retrogression. In contrast with earlier studies, the term varies as a function of geographical location. The estimation is performed using the adjoint model. The results deviate from those earlier derived theoretically and applied in routine forecasting. The Cressman term can now be viewed as a corrector of the systematic error or as a baroclinity parameter. The proposed form of the Cressman term can also be interpreted as a forcing parameter, maintaining the troughs and ridges of the main circulation by affecting the free long waves. Parameter estimation using the adjoint model has shown its potential in these experiments. Not only are the parameter values determined but new interpretations and approaches have been found.

Late results of laterofixation in the treatment of bilateral abductor paralysis of the vocal cords: a clinical study with long-term follow-up

Thirty-four patients with bilateral vocal cord abductor paralysis were treated surgically during the period from 1960 to 1979. The main cause of paralysis was thyroid surgery (85%). Woodmans external laterofixation was performed in 31 patients, 1 had laterofixation by laryngofissure and 2 had endoscopic arytenoidectomy. In Woodmans procedure the body of the arytenoid cartilage was removed in 10 cases and mobilized from the cricoarytenoid joint in 21 cases. Thirteen of the 34 patients needed further surgery. Including previously performed procedures in 6 patients, altogether 68 operations were performed and 17 patients (50%) were operated on more than once. The immediate failure rate of laterofixation was 22% but the need for reoperation increased with time and the total failure rate of the method was 44%. Endoscopic arytenoidectomy was successful in 1 of 2 cases as a primary operation and in 3 of 3 cases as secondary operation. Follow-up time ranged from 2 months to 29 years 8 months (mean 15 years 10 months).

Laryngeal stenosis following papillomatosis--a report of three severe cases.

Three cases of severe laryngeal papillomatosis beginning in early childhood are presented. Several methods of treatment were tried, but lasting results were achieved by suction diathermy. The laryngeal lumen was totally obliterated in all cases during the course of the disease. The patients were successfully operated on by making a laryngofissure in the front part of the larynx, excising the scar and enlarging the lumen by a median incision in th back wall of the larynx. An indwelling prosthesis was placed in the larynx for several months. After removing the prosthesis, the laryngeal lumen was dilated several times by oesophageal sounds. All patients were successfully decannulated. The results of treatment are evaluated both clinically and by ventilatory function studies. Central airway obstruction persisted in two cases.

Autocorrelation Functions Computed from Daily 500 mb Geopotential Height Analyses

Abstract A method of computing autocorrelation fields with the aid of empirical orthogonal functions (EOF) is applied. The isotropic parts of the fields are separated, and a one-parameter model of the isotropic autocorrelation field is constructed. The approximation is compared with the Bessel representations discussed by others. The present model requires fewer parameters (one as against four) and gives a more realistic representation at greater distances. In other respects, the results are quite similar. At midlatitudes, the present model is a good approximation of the autocorrelation fields. Over the Himalayas, the fields are exceptionally anisotropic. The results substantiate the importance of the Himalayas in teleconnectivity.

A Rapid Method of Computing Empirical Orthogonal Functions from a Large Dataset

Abstract A rapid method of computing the EOFs for a problem with a large covariance matrix is presented. The resulting EOFs are not the “true” ones because they do not guarantee that the maximum variance is explained in the dependent sample. However, in an independent sample they turn out to be very efficient when compared with the “true” EOFs computed from a very large dataset. The differences between different EOF sets do not necessarily indicate essential differences in the corresponding sets of the source data. A rotation for secondary reasons may produce very noticeable differences between the EOFs.

Random analysis error of 500 mb height analyses for the FGGE year

Abstract Different methods of studying the random error variance of 500 mb geopotential height analyses are discussed and applied. It has not been possible to show that the random errors of the operational analyses during the FGGE year have been smaller than those of previous years. In contrast to this, however, it is concluded that there have never been analyses of a quality comparable with the delayed-mode FOGE analyses (leaves IIIb/ECMWF). This conclusion is based on the whiteness of the error spectrum and the small variance of the random error. The variances of the random errors of the operational analyses over a dense observational network are small. The maxima are found over the Pacific, the Atlantic, the Himalayas and around the North Pole. Their intensity varies from one analysis set to another. In the delayed-mode analyses, the distribution of the error variance is flat. One operational analysis set shows a similar flat distribution. The reason for this flatness is believed to lie in the smoothin...

Estimation of the Analysis Error Variance of the 500 mb Height Analyses in the Northern Hemisphere, 1946–79

Abstract The yearly variances of the analysis error of the 500 mb height north of 20°N are estimated from analyses covering the period 1946–79. A new method is presented. The error variances are computed directly from the analyses without any assumptions concerning the observational network, the observation error or the analysis system. The results show a general decrease of the analysis error variance up to 1970, since when it has been fairly constant. A weak increase is visible in analyses from 1976 onward. The present day error variance is about half of that for the years preceding the International Geophysical Year. Sudden peaks occur when the analysis center was changed. Local developments are discussed. When subsamples are compared with each other, the problematic area in 1955–62 turn out to be around the North Pole, around the Great Lakes, and the area westward from Kamchatka. Over these area some phenomena have been analyzed less accurately than expected. In 1962–70 a problematic area is found ove...

Numerical Approximations Can Create Chaos-related Errors in Blocking Forecasts

Abstract The chaotic structure of two-dimensional atmospheric flow is illustrated. It is shown that certain errors in numerical approximations can Prevent the correct prediction of chaotic processes. This is the case when the numerical approximations do not sufficiently allow air parcels to deviate from each other. The error mechanism is described with a case study and is proposed as one explanation for the errors observed when forecasting the development of blocking highs. It can explain why the errors in blocking highs are similarly found in different models from different centers, why they appear in medium-range forecasts but not in short-range forecasts, and why the error decreases only slowly with increasing resolution.