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Nordlund, G. 1974. Prediction of success in secondary school studies. Scand. J. educ. Res. 18,133-150. Extensive research in predicting academic success in higher education completed in many countries shows that pupils' average marks (grade-point average) is the most accurate predictor. The project described here, which supports earlier research, studied the value of the pupils' present average marks in predicting their academic performance at secondary schoolj compared the prediction value of their average marks with that of ability and achievement tests, and investigated to what extent the selection of pupils can be improved with the help of marks and test results together.

During the period 1956-1969, a total of 765 patients with thoracic injuries - either isolated or combined with other injuries - were treated as in-patients at the University Hospital, Uppsala. The over-all mortality during this 14-year period was 9% (69/765). In patients with isolated thoracic injuries the mortality was 2% (9/447). In 5% (38/765) thoracotomy was performed. In general, however, active conservative measures were found adequate in most of these patients. In 8% (61/765) the use of a respirator was considered indicated - mainly because of flail chest. Our principles of treatment have remained unchanged by our experience during these years. The importance of the time factor in diagnosis and treatment for the outcome in patients with thoracic injuries is stressed.Thoracic injuries occupy a prominent place in the accident statistics of today (Chandler, 1957; Wulff et al., 1957; Johansson & Silander, 1959). An increase of both the number of injuries due to traffic accidents and the proportion of thoracic injuries among them has been reported (Solhem, 1963). During the years 1956-1969, a total of 765 patients with thoracic injuries were treated as in-patients at the University Hospital of Uppsala, and comprise the material of the present study. They included both patients from the hospital's own district and patients referred to us from other hospitals within a region representing about two million inhabitants. Out-patients are not included. Neither does the material include patients who were dead on arrival at the hospital. Thus the material is selected, with some over-representation of complex thoracic injuries during the period under review. The aim of this study was to consider the therapeutic principles in the light of experience gained, with special regard to indications for respirator treatment and for surgical intervention.

Directional hearing was studied in patients with various types of hearing defects, in order to estimate the value of directional audiometry as an aid to the topical diagnosis of hearing impairments. In a previous paper a method of directional audiometry has been described and analysed. In this paper directional hearing was measured by this method in 51 normal hearing subjects, and in 101 patients with different types of hearing disorders. It was found that patients with conductive losses generally had slightly reduced ability for angular localization. Patients with cochlear lesions were found to have a relatively well preserved directional hearing. In patients with lesions of the auditory nerve or the pons angular localization was poorer. Directional audiometry is considered to be of great value for differentiating between cochlear and so called retrocochlear lesions, i.e. lesions of the auditory nerve or the pons.ZUSAMMENFASSUNGDas Richtungshören von Patienten mit verschiedenen Arten von Gehörschäden wurde einer Untersuchung unterzogen, die den Wert der Richtungsaudiometrie als ein Hilfsmittel zur topischen Diagnose von Gehörverschlechterungen dienen sollte. Die Metode der Richtungsaudiometrie ist in einer vorgehenden Abhandlung im Einzelnen beschrieben worden. In der vorliegenden Veröffentlichung wird das Ergebniss vom Messresultat an einundfünfzig normalhörenden Personen sowie von ein-hundertein Patienten mit verschiedenen Gehörstörungen ausgewertet. Es zeigt sich dabei, dass Vermögen der Winkellokalisation bei Personen mit Leitungsschäden leicht verringert ist. Ebenso haben Patienten mit Innenohrschäden ein verhältnis-mässig gut erhalternes Richtungshörvermögen. Dagegen ist diese Fähigkeit bei Personen mit Schäden des Gehörnerven oder der Pons verringert. Die Richtungsaudiometrie darf daher als eine wertvolle Methode zur Unterscheidung zwischen kochlearen und retrokochlearen Schäden betrachtet werden.

The investigation was carried out for the purpose of clarifying the acoustic differences which arise between the ears at different azimuths. Measurements of time, phase and intensity differences of the sound entering the ears of a dummy head were performed with the sound source placed at different azimuths around the head, and using the frequencies 500, 1000, 2000, 4000 and 8000 cps, with the sound source 165 cm from the head. The results indicate that the time difference constitutes a linear function of azimuth between the angles of 0°-60° and between 120°-180°. The same thing applies to the phase difference, if expressed in time. The difference in intensity appears to be a very irregular function of azimuth and has to a great extent failed to agree with previously published findings. The matter of directional hearing is discussed on the basis of physical measurements and data obtained.

Human serum and plasma have been shown to abolish the pyrogenicity of poly I:poly C. Chicken serum and, to a lesser extent, fetal calf serum also possess this inhibitory effect, while serums of six other animal species do not alter the pyrogenic properties of this compound. The inhibitory effects are time- and temperature-dependent and suggest that they are enzymatic in origin.

Stereophonic hearing aids shall preferably be recommended when binaural hearing tests show improvement in hearing compared with monaural listening and when localization of sound is of importance.

Release of the protein molecule, leukocytic pyrogen, is one of the many reactions exhibited by leukocytes after phagocytosis. After the ingestion of heat-killed S. albus, a 3–4 hr latent period exists, during which human peripheral leukocytes release no pyrogen, yet cellular metabolism is altered in such a way that pyrogen output may subsequently occur in the absence of further phagocytosis. Transcription of messenger RNA and translation of new protein are initial events in the. activation process, since addition of the inhibitors, actinomycin D, and cycloheximide or puromycin, during this period markedly depressed or abolished subsequent pyrogen release. These effects were noted to be dependent upon the time of addition of the inhibitors. None of the inhibitor drugs interfered with cell viability as measured by phagocytosis and hexose monophosphate shunt activity, nor did they alter the pyrogenicity of preformed leukocytic pyrogen. Vincristine did not inhibit pyrogen formation, consistent with its reported failure to alter RNA synthesis in mature human granulocytes. The glycolytic inhibitor, sodium fluoride, blocked pyrogen release both when added prior to particle ingestion or 1 hr after the initiation of phagocytosis. Whereas inhibition of phagocytosis would explain the sodium fluoride effect prior to 1 hr, this was not observed in leukocyte preparations incubated for 1 hr with S. albus before adding sodium fluoride. When sodium fluoride was added to preparations 2 hr after the start of incubation, the LP production was unimpaired. Potassium cyanide had no effect on cell activation or pyrogen release. These findings suggest that the primary energy supply for the activation process is derived from high energy phosphate bonds provided by anaerobic glycolysis. Since the major amount of cell activation appears to occur in the 1st hr after phagocytosis, this energy might be involved in the induction of a genome leading to the transcription of m-RNA and its translation into new protein or is required for polysome integrity during protein synthesis. It is suggested that this new protein may be leukocytic pyrogen itself, or an enzyme responsible for cleaving it from an inactive precursor.

The aim of the preoperative investigations of patients with hearing loss, including clinical, X-ray and audiometric examination, is to answer the following questions:How great a handicap does the patient have from his hearing loss? Is there any active infection, irritation or cholesteatoma present, which can defeat an operation to improve hearing? How well are the Eustachian tubes functioning? Are there any morphological or functional defects in the eardrum or ossicles? How well are the oval and round windows functioning? How good is the sensori-neural function? Not until these questions are answered is it possible to judge whether there are any indications for operation and what type of operation should be performed.

The aim of the investigation was to study how speech signals are influenced by the angle of incidence of the sound towards the head, i.e. azimuth. The study was made by means of an artificial head with condenser microphones at the site of the eardrums. Speech signals were recorded via these microphones and were then subjected to spectrographic analysis. PB lists of Swedish monosyllables were also recorded via the head and their intelligibility was investigated. It was shown that azimuth has a substantial influence on speech signals. The intelligibility for binaural listening is significantly better than for monaural listening at all azimuths tested. The information reaching the ear turned towards the sound source is markedly better than at the ear turned away from the sound source.

An artificial head has been made of a cranium and soft plastic material. The model is used to study the interaural intensity difference as a function of frequency and azimuth, i.e. the angle of incidence of the sound towards the head. The interaural intensity difference is found to be a very irregular function and sensitive to small changes in the experimental conditions. This gives an explanation for the difficulties of reproducing the results of free field investigations.

The investigation was carried out to develop a method for directional audiometry that, will provide a test of the different functions in angular localization. The method has the following properties. (1) What we have called "physiological directional hearing", i.e. the ability to angular localization of a sound source in a free field, can be estimated. (2) Defective ability to discriminate interaural time, phase and intensity differences can be detected individually. The sources of error of the method are carefully investigated with the aid of an artificial head.In future work this method for directional audiometry will be tested clinically in order to estimate the value angular localization may have for the topical diagnosis of hearing defects.

A patient suffering from polymorphous light eruption did not respond to conventional modes of therapy. Phototesting demonstrated that he was sensitive to light from 290 to 500 nm. The patient was treated with a combination of sulisobenzone and β-carotene, with amelioration of the disease.

Melanocytes are derived in the embryo from the neuroectoderm. They are responsible in part for formation of the inner ear. There is a frequent association of congenital pigmentary abnormalities with hearing loss and neurologic diseases. Examination of patients with inherited pigmentary disorders might reveal that the genetic defect affects all tissues of neuroectodermal origin. The findings in our patient are consistent with this hypothesis. Electron microscopic findings of the lentigines are reported.

A large invasive facial ulcer probably represents an unusual trichoepithelioma. The lesion responded readily to topical application of fluorouracil.

Although carbon dioxide (CO2) is commonly used as an anesthetic for insects, its side effects are not completely understood. Behavioral or physiological alterations caused by exposure to CO2 have been reported in the German cockroach, Blattella germanica (L.) (Brooks 1957, 1965), and the house cricket, Acheta domesticus (L.) (Edwards and Patton 1965). In lepidopterous insects, CO2 has been shown to reduce: (1) mating frequency and oviposition in the female Mediterranean flour moth, Anagasta kuchniella (Zeller) (Janisch 1924); (2) mating frequency in the cabbage looper, Trichoplusia ni (Hübner) (Shorey 1964); (3) male responsiveness to the female sex pheromone in the Indian meal moth, Plodia interpunctella (Hübner), (Whisenant and Brady 1967); (4) and egg production and hatchability in P. interpunctella (Lum and Flaherty 1972).

Eggs of Heliothis zea (Boddie) were applied to plants using a pneumatic sprayer with solution of Plantgard® as an adhesive. The pneumatic sprayer was also used for the application of kairomones to plants in the field. The Plantgard did not affect the acceptability of the eggs by the parasite Trichogramma evanescens Westwood and had no antagonistic effect on the kairomone tricosane.

Female Plodia interpunctella (Hübner) reared and observed in a 12:12 h light: dark (L:D) regime exhibited a calling rhythm with a maximum calling beginning ca. 2 h after the initiation of scotophase and continuing until the initiation of photophase. When held in a constant light (L:L) regime, L:D-reared females lost their calling rhythm within 2 days. When reared and held in a L:L regime, females called continuously. With L:L females held in a L:D regime, a rhythm similar to that of L:D females held in L:D was entrained within 2 days.

Sex pheromone released by nonmated female Plodia interpunctella (Hübner) was collected on filter paper and bioassayed to determine the relative amounts of sex pheromone released by females reared and held in a 12:12 h light:dark regime (L:D) and by females reared and held in a constant light regime (L:L). A regression, constructed from tests with synthetic sex pheromone, cis-9, trans-12-tetradecadien-1-ol acetate, was used to quantitate the amount of sex pheromone released by females. This data was then correlated with calling behavior, to measure the rate of sex pheromone release per calling female. During scotophase, calling L:D females release pheromone at a rate ca. 13 times that during photophase. In comparison, the sex pheromone release rate of L:L females during the scotophase was not significantly different from the release rate during photophase. These rates correlate with the calling behavior of L: L females‥ Abdominal tips of L:D females contained slightly more sex pheromone at collection times during photophase than at collection times during scotophase when calling is maximum. No correlation was found in the amount of sex pheromone contained in the abdominal tips of L:L females and time of day. Turnover rate of sex pheromone was estimated in calling L:D and L:L females during scotophase and photophase.

This film relates to the papers on "Physical Factors in Angular Localization" (Vol. 54: 1) and "Angular Localization" (this issue), and may be borrowed on application to Dr. B. Nordlund, Sahlgrenska Hospital, Gothenburg. It is a 16 mm colour film with magnetic sound, and runs for 23 minutes.

IN a recent paper from this laboratory1it was shown that sucrose is formed both from glucose and from fructose when starch-depleted leaves of red clover or wheat plants are placed in 10 per cent solutions of these hexose sugars in the dark. This result was explained by assuming that glucose and fructose are transformed into each other in plant tissue.