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Information transfer analysis [G. A. Miller and P. E. Nicely, J. Acoust. Soc. Am. 27, 338-352 (1955)] is a tool used to measure the extent to which speech features are transmitted to a listener, e.g., duration or formant frequencies for vowels; voicing, place and manner of articulation for consonants. An information transfer of 100% occurs when no confusions arise between phonemes belonging to different feature categories, e.g., between voiced and voiceless consonants. Conversely, an information transfer of 0% occurs when performance is purely random. As asserted by Miller and Nicely, the maximum-likelihood estimate for information transfer is biased to overestimate its true value when the number of stimulus presentations is small. This small-sample bias is examined here for three cases: a model of random performance with pseudorandom data, a data set drawn from Miller and Nicely, and reported data from three studies of speech perception by hearing impaired listeners. The amount of overestimation can be substantial, depending on the number of samples, the size of the confusion matrix analyzed, as well as the manner in which data are partitioned therein.

It is well known that discrimination response variability increases with stimulus intensity, closely related to Weber's Law. It is also an axiom that sensation magnitude increases with stimulus intensity. Following earlier researchers such as Thurstone, Garner, and Durlach and Braida, we explored a new method of exploiting these relationships to estimate the power function exponent relating sound pressure level to loudness, using the accuracy with which listeners could identify the intensity of pure tones. The log standard deviation of the normally distributed identification errors increases linearly with stimulus range in decibels, and the slope, a, of the regression is proportional to the loudness exponent, n. Interestingly, in a demonstration experiment, the loudness exponent estimated in this way is greater for females than for males.

We investigated the nature of the freezing in the geometrically frustrated Heisenberg spin glass Y2(Mo2)O(7) by measuring the temperature dependence of the static internal magnetic field distribution above the spin-glass temperature, Tg, using the muon spin relaxation technique. The evolution of the field distribution cannot be explained by changes in the spin susceptibility alone and suggests a lattice deformation. This possibility is addressed by numerical simulations of the Heisenberg Hamiltonian with magnetoelastic coupling at T > 0.

During the last years, a growing number of inherited skin disorders have been recognized to be caused by abnormal function of desmosomal proteins. In the present study, we describe the first female individuals affected with the ectodermal dysplasia/skin fragility syndrome (MIM604536), a rare autosomal recessive disease due to mutations in the PKP1 gene encoding plakophilin 1, a critical component of desmosomal plaque. One patient was shown to carry a homozygous splice site mutation in intron 4. The second patient displayed a homozygous recurrent mutation affecting the acceptor splice site of intron 1. Both mutations were associated with intraepidermal separation, widening of intercellular spaces, and abnormal desmosome ultrastructure, and were found to result in the absence of immunoreactive plakophilin 1 in the epidermis of the affected individuals. These two cases emphasize the role of molecular genetics in the assessment of congenital blistering in newborns and illustrate the importance of proper desmosomal activity for normal epidermis development and function.

The power function exponent for loudness is traditionally determined by means of a process of magnitude estimation. It is demonstrated in this paper that the exponent can also be obtained by using the procedure of absolute identification of sound intensity. It has been shown that subjects' responses to tones of a given intensity are distributed in a normal distribution whose variance depends on the range, R, over which the tones are distributed. By means of a standard statistical transformation, the normal density in log space is converted to the corresponding probability density in linear space. The power function exponent can then be obtained directly from the linear probability density. We also suggest that there is a direct relationship between the information calculated from experiments on absolute identification of sound intensity and the neurophysiological, poststimulus histogram measured in a nerve fiber in the auditory nerve.

This paper considers the information transmitted in absolute judgments as encoded in a stimulus-response matrix (e.g., see Garner and Hake, 1951). When transmitted information is plotted against the number of stimulus categories in the matrix, one obtains a curve that increases monotonically toward a plateau, which is the maximum information transmittable per stimulus for the particular range of stimuli employed. We demonstrate that although the maximum information transmitted is an attribute of the stimulus continuum itself, the shape of the curve is an empirical property of the stimulus-response matrix, which is determined, in part, by maintaining a constant stimulus category width. Therefore, in principle, each curve of information transmitted vs number of stimulus categories can be determined by a single point: the rightmost point on the graph. Copyright 2001 Academic Press.

Candida albicans adherence to epithelial cells is the first step in the infectious process, but in spite of its importance, current methods for the quantitative measurement of adherence of C. albicans to epithelial cells in vitro have some serious limitations. They are based on filtration assays and either microscopic or radiometric analysis. The adherence reaction is usually carried out with a large excess of yeasts (100-fold) over epithelial cells in order to perform the microscopic analysis, which is slow, subjective and limited to 100-200 cells and thus lacks statistical power. The radiometric analysis fails to measure individual cells. A method for measuring yeast adherence that overcomes these problems has been developed. It is based on labelling the yeasts with the fluorogenic marker 2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (BCECF) prior to the adherence reaction, and analysing 10(4) epithelial cells by flow cytometry, while nonbound yeasts are excluded by gating. Two subpopulations of buccal epithelial cells (BECs) which differ in their mean fluorescence intensities per cell (MFIs) were observed: one with MFI which did not exceed nonspecific fluorescence, and the other with MFI as high or higher than the MFI of labelled yeasts. The two subpopulations represent yeast-free and yeast-binding epithelial cells, respectively, and the MFI increment of the BECs is a quantitative measure of the extent of yeast adherence. Control experiments confirming previously described basic features of adherence, such as enhanced adherence at increasing yeast excess, diminished adherence of trypsin-treated or heat-inactivated yeasts, and the differential adherence of various Candida species, supported the validity of the assay. The possibility of studying adherence reliably at low yeast:epithelial cell ratios, which better mimic adhesion as it occurs in vivo, is an important advantage of the assay. New findings, using this method, included the observation that exfoliated BECs from diabetic patients exhibited the same capacity for C. albicans adherence as cells from healthy controls, and that epithelial cells from early human ontogenic stages had a significantly lower adherence level than those from later stages.

We compared the effects of doxycycline and tetracycline hydrochloride on the subjective symptoms in ocular rosacea. Twenty-four patients with symptomatic ocular rosacea were randomly assigned to two groups and treated with doxycycline 100 mg/day (group 1, 16 patients) or tetracycline hydrochloride 1 g/day (group 2, eight patients). The dosages of each drug were gradually tapered and discontinued according to symptomatic response. At each examination all the manifesting symptoms were scored by the patients. Patients were followed up from six weeks to three years. After six weeks of drug treatment, all patients except one had symptomatic improvement. Although most of the scores of the symptoms were significantly decreased in both groups, greater symptomatic relief occurred in the tetracycline hydrochloride-treated patients (P = .041). However, after three months of treatment there was no significant difference in symptoms between the two groups. Gastrointestinal tract complications occurred in two of the 16 patients (12.5%) in group 1 and in three of the eight patients (37.5%) in group 2. Both tetracycline hydrochloride and doxycycline can control the symptoms of ocular rosacea.

A 44-year-old man with Sturge-Weber syndrome developed a basal cell carcinoma at the site of a nevus flammeus on his right cheek, which had been treated with a course of grenz rays at six years of age without obvious improvement. He also exhibited erythematous papulovesicular lesions on the upper trunk, which histologically proved to be transient acantholytic dermatosis. The association of nevus flammeus and basal cell carcinoma is extremely rare; to the best of our knowledge, only four similar cases have been previously reported.

A double-blind controlled study, in two parts, was undertaken to compare the effectiveness of aminophylline and doxapram therapy in idiopathic apnea of prematurity. In the first part of this study, eight of 15 infants responded to doxapram therapy with complete cessation of apneic spells and six of 11 infants responded similarly to administration of aminophylline. These differences were statistically insignificant. In the second part of the study, assessment was made of whether the addition of doxapram to aminophylline therapy was effective in treatment of apnea of prematurity that had been unresponsive to aminophylline alone. Of ten infants who continued to have apneic spells during treatment with aminophylline, eight responded to the addition of doxapram with complete cessation of apnea. Nine infants received placebo in addition to aminophylline, and none had a reduction in frequency of apnea.

Fourteen patients with RDC diagnosis of primary, endogenous, major depressive disorder were studied in an inpatient setting. All were non-suppressors on the Dexamethasone Suppression Test on admission to hospital and were retested at discharge. Over 70% of patients continued to be non-suppressors at discharge, when in clinical remission. Four out of 14 patients converted to normal suppression. All 10 of the non-normalizers did poorly on follow-up: 3 patients committed suicide. All normalizers did well. Non-normalization of the DST at discharge from hospitalization may be more common than previously suspected and predicts poor clinical outcome.

Pemphigus is an intraepidermal autoimmune blistering disease of humans caused by circulating IgGs. We have investigated the binding mode and the fate of bound antibodies from Pemphigus sera (P-IgG) on guinea pig keratinocytes in suspension in order to find clues to the loss of cell adhesion in vivo (acantholysis). Flow cytometry, following indirect immunofluorescent labeling of the keratinocytes, and dead cells' staining with ethidium bromide, demonstrated the specific surface binding of P-IgG onto living keratinocytes only. This was shown with several Pemphigus sera or purified P-IgG. This technique, used with various Pemphigus sera, showed that the specific binding is increased when the serum titer is higher, and "Km" values for P-IgG were roughly and inversely correlated to the titers. Upon saturation the same average number of Pemphigus IgG sites per cell were found for the sera of different patients. Analysis of the specific binding of [125I]-P-IgG onto Percoll-separated (living) keratinocytes showed the existence of two classes of sites: 2 x 10(6) sites/cell high-affinity sites (Kd = 1.5 x 10(-6) M total IgG) and 25 x 10(6) sites/cell low-affinity sites (Kd = 6 x 10(-5) M total IgG). Cell sorting and flow cytometry of individual cells allowed us to correlate the light-scattering signal, the RNA content, the size and morphology, and the P-IgG binding to the cells. The results indicated that P-IgG binding is homogeneous within the living keratinocytes and increases with cell size (cell maturity). Cell-sorter analysis of cells with membrane-bound P-IgG, coupled to direct determination of P-IgG released in the medium, revealed the fate of bound P-IgG: 40-60% of the P-IgGs were released in the medium within 30 minutes at 37 degrees C. This was accompanied and followed by a much slower, metabolic energy-dependent, internalization process of the membrane-bound P-IgG. The internalization has been confirmed by electron microscopy of bound P-IgG labeled with protein A-gold. Internalized IgGs were seen in the cells in coated membranous vesicles and other endocytic compartments. Similar behavior was also observed with two other membrane ligands: i.e., concanavalin A and multispecific rabbit "antisurface" antibodies.

During gestation the fetus is abundantly provided with vitamin C, but inadequate postnatal provision of the vitamin may lead to early hypoascorbemia. Since premature newborns are often prevented from full alimentation for a considerable length of time, ascorbate deficiency may result. Plasma ascorbate levels of 20 premature newborns were determined during the first two weeks of life. Daily ascorbate intake of less than 5 mg/kg b. w. resulted in a decline of plasma ascorbate level from 1.56 +/- 0.15 mg/100 ml (mean +/- SEM) on the first day of life to a low level of 0.48 +/- 0.05 mg/100 ml by two weeks of age. An increase of daily ascorbate intake to 5--10 mg/kg b.w. resulted in a higher plasma concentration of 0.79 +/- 0.09 mg/100 ml (p less than 0.02) while parenteral supplementation of 50 mg vitamin C daily provided for a high plasma concentration of 2.7 +/- 0.46 mg/100 ml (p less than 0.005) when compared with the other two groups. Maturational and environmental factors may impose a higher demand for vitamin C during early premature life and therefore adequate amounts of the vitamin should be early provided.

A small, double-blind crossover study compared the efficacy of aminophylline and doxapram in ventilator weaning of eight premature infants recovering from respiratory distress syndrome (RDS). Although neither drug was significantly better than the other, four infants were weaned from mechanical ventilation after drug administration. It is suggested that drugs stimulating the respiratory center may aid in shortening the duration of mechanical ventilation in premature infants recovering from RDS.

A 2-year-old girl developed an erythematous papular eruption on her face and extremities a week after an epidemic of hepatitis A had occurred in her school. Clinical and laboratory signs of acute hepatitis, together with serologic verification, confirmed hepatitis A infection. That diagnosis should be considered in the etiology of papular acrodermatitis of childhood.