Effect of depth separation on metacontrast masking

In most investigations of visual masking, spatially adjacent contours are located in the same depth plane, a practice derived from the assumption that depth is not a critical variable in contour formation. In nine experiments, the dependence of masking on the relative depth positions of the target and mask was examined. To permit facile manipulation of depth without introducing confounding changes in proximal stimulation, the stimuli were stereoscopic contours formed from dynamic random-element stereograms generated as anaglyphs on a projection color-television display. The target was a briefly presented Landolt C with gap position randomly varied; the mask was an annulus that surrounded the target. Masking with stereoscopic contours was robust and subject to the same spatial and temporal variables influential in masking with physical contours. Depth separation of the target and mask produced significant reductions in masking and interacted with temporal order and egocentric stimulus position. These results have implications for models of visual masking and indicate that perceived depth is important in contour formation.

Teachers as agents of behavioral change for severely retarded students

This paper describes two case studies, which employed behavioral modification procedures to decrease problematic behaviors of severely retarded students. The studies were carried out in public school settings. Special education teachers under the direction of a school psychologist acted as the agents of behavioral change.

Assessment of stereopsis in human infants

A new method for testing stereopsis in infants is described for use in the early assessment of binocular function. Four 6- and 12-month-old infants were presented with a dynamic random-element stereogram generated on a color television monitor. A stereoscopic form was moved laterally, either left or right, to elicit the visual attention of the infant. An observer, unaware of the direction of form movement, made a forced-choice judgment of the direction of form displacement based on information gleaned from observations of the infant's behavior. The observer's performance for all three age groups exceeded chance levels of responding (p < 0.001). Individual infants within each age group also provided strong evidence of stereopsis. The applicability of the method for the screening of binocular anomalies is discussed.

Effect of depth separation on metacontrast masking

In most investigations of visual masking, spatially adjacent contours are located in the same depth plane, a practice derived from the assumption that depth is not a critical variable in contour formation. In nine experiments, the dependence of masking on the relative depth positions of the target and mask was examined. To permit facile manipulation of depth without introducing confounding changes in proximal stimulation, the stimuli were stereoscopic contours formed from dynamic random-element stereograms generated as anaglyphs on a projection color-television display. The target was a briefly presented Landolt C with gap position randomly varied; the mask was an annulus that surrounded the target. Masking with stereoscopic contours was robust and subject to the same spatial and temporal variables influential in masking with physical contours. Depth separation of the target and mask produced significant reductions in masking and interacted with temporal order and egocentric stimulus position. These results have implications for models of visual masking and indicate that perceived depth is important in contour formation.

Weight loss with psychiatric residents in a behavioral self control program

A behavioral self-control program for 14 psychiatric residents living in a semi-independent residential facility is described. The group of 7 in behavior therapy lost significantly more weight than a control group of 7 over a 14-wk. treatment. A 16-wk. followup is reported.

A weight reduction model for mildly retarded adults living in semi-independent care facilities

A behavioural weight reduction treatment model for use with retarded adults is discussed. The model describes five stages of the treatment programme. Instructional components and techniques are reviewed. The model was designed for implementation by nurses, dieticians, and other nutritional health educators.

Stereopsis in human infants

Stereoscopic depth perception was tested in human infants by a new method based on attracting the infant's attention through movement of a stereoscopic contour formed from a dynamic random-element stereogram. The results reveal that stereopsis emerges at 3 1/2 to 6 months of age, an outcome consistent with evidence for rapid postnatal development of the visual system.

Incidental learning in mildly retarded children

Fifteen mildly retarded children (mean CA = 11 years, MA = 8 years, IQ = 71), Including nine males and six females, were compared with the same number of both CA- and MA-matched intellectually normal children, including 14 males and 16 females, on a Type I incidental learning task involving simple recognition and recall skills. The results of this comparison found that the retarded group learned incidentally, as well as the MA-matched normal group, but exhibited significantly poorer incidental learning than the CA-matched normal group. These results supported the hypothesis that an incidental learning deficiency exists for the retarded group compared with the CA-matched intellectually normal children but not with the MA-matched normal children.

Lymphomatoid granulomatosis in a renal transplant recipient

Lymphomatoid granulomatosis is a multi-system disorder of high mortality and characterised by angiocentric and angiodestructive lymphoreticular proliferative and granulomatous change. A case is described of this disease occurring in a renal transplant patient. The patient underwent a rapid remission of the disease after a course of combined cytotoxic therapy and remains free of disease three years after treatment. This case is the second described renal transplant patient to develop the disease and the first to be successfully treated. It is likely that the disease originated as a consequence of immunosuppression similar to the development of lymphomas in allograft recipients.

The chronicity of symptoms and disability in Reiter's syndrome. An analysis of 131 consecutive patients

To assess the natural history of Reiter's disease, we evaluated 131 consecutive patients at a university clinic or at a community center. One hundred twenty-two patients (93%) were available for follow-up at a mean of 5.6 years. The results showed that there were no major differences between patients at the two centers; at follow-up, 101 (83%) had some disease activity, 27 (22%) had annoying symptoms, 42 (34%) had sustained disease activity, 19 (16%) had had to change jobs, and 13 (11%) were unemployable; there were no major differences between the 19 (15%) females and 112 (85%) males or between the HLA-B27-positive (83%) and -negative (17%) patients, except for increased prevalence of sacroilitis and chronic uveitis in HLA-B27-positive patients; and, at entry, only increased heel disease differentiated those destined to have a poor prognosis. Most patients with Reiter's syndrome have persisting symptoms that can lead to chronic disability.

A serologic comparison of Moloney lymphoma cell surface and Moloney oncornavirus antigens

Moloney lymphomas and Moloney sarcomas share strong tumor antigens. In this report we analyze the cell-surface antigens on a Balb/c Moloney lymphoma, LSTRA, using hyperimmune sarcoma regressor sera (alphaMo) as a primary reagent. We also use heterologous anti-viral p30 and gp70 sera for a direct analysis of virion protein antigens on the LSTRA surface. Using radiolabeled alphaMo-binding assays, we demonstrate that LSTRA tumor antigens detected by these sera are all Moloney viral antigens; approximately 1/3 of these antigenic determinants are expressed on the intact virus, and the other determinants are revealed by detergent lysis of the virus. The major viral antigens expressed on the LSTRA cell surface are viral env gene products, whereas gag gene products are only sparsely represented. We conclude that alphaMo sera detect almost exclusively viral antigens on LSTRA cells, and these antigens are almost exclusively virion env gene products.

Nondepressant beta-adrenergic blocking agents. 1. Substituted 3-amino-1-(5,6,7,8-tetrahydro-1-naphthoxy)-2-propanols

A series of 3-amino-1-(5,6,7,8-tetrahydronaphthoxy)-2-propanols was synthesized and investigated for beta-adrenergic blocking activity and direct myocardial depressant action. The cis- and trans-diols 12--15 were found to retain the beta-blocking potency of propranolol but to lack its myocardial depressant action. Compound 15 (nadolol) is currently undergoing extensive clinical evaluation as a potential antianginal, antiarrhythmic, and antihypertensive agent.

Correlation of aqueous humor ascorbate with intraocular pressure and outflow facility in hereditary buphthalmic rabbits

The hypotensive effect of ascorbate on intraocular pressure has been reported following topical application, oral administration, or anterior chamber infusion in animals. The present report describes the correlation of aqueous humor ascorbate concentration with intraocular pressure as well as outflow facility in vivo. Low aqueous ascorbate level was seen in buphthalmic eyes with high intraocular pressure and low outflow facility. The opposite correlation was observed in normal eyes. Ascorbate concentration in the anterior chamber of the rabbit eye is apparently related to the alteration of outflow facility and the movement of fluid in the anterior chamber.

Amniotic fluid copper and zinc concentrations in human pregnancy

Amniotic fluid concentrations of zinc and copper were measured in human pregnancy of 12 to 44 weeks' gestation. Although mean values for both metals are relatively flat throughout pregnancy, there appears to be a relative increase in copper levels between 26 and 33 weeks' gestation, and increasing levels of zinc after 34 weeks. Correlations with fetal age or fetal-maternal disease are not apparent in specimens from this heterogenous population.

Stereopsis in the falcon

Stereoscopic depth perception is demonstrated in the falcon, a non-mammalian with binocular vision. This result complements recent physiological evidence for binocular interaction in the bird visual system, and suggests that stereopsis may be a general attribute of vertebrate vision and not an exclusive product of mammalian evolution.

Plasma arginine vasopressin in the syndrome of antidiuretic hormone excess associated with bronchogenic carcinoma

A study of plasma arginine vasopressin in 17 patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) associated with bronchogenic carcinoma, revealed that the arginine vasopressin levels were distinctly elevated in most. In 14 patients with bronchogenic carcinoma, but without overt SIADH, plasma levels of arginine vasopressin were significantly higher than in normal subjects (p less than 0.001). This, together with the finding of a lower than normal plasma osmolality in this group, suggests that inappropriate ADH excess might be much more common in patients with bronchogenic carcinoma than previously thought. The normal positive correlation between plasma osmolality and plasma arginine vasopressin was found to be reversed in SIADH. Seven of nine patients with overt SIADH, studied after fluid deprivation, showed an increase in plasma arginine vasopressin coincident with an increase in plasma osmolality (r = +0.8, p less than 0.01); in one patient, plasma arginine vasopressin returned to the original level following rehydration. The possibility that this might imply a degree of physiologic control to what is generally considered an autonomous secretion is discussed. It is, however, considered more likely that other factors, including changes in plasma volume and glomerular filtration, might explain the increase in plasma levels of arginine vasopressin.

Aqueous ascorbate concentration in hereditary buphthalmic rabbits

Some aqueous humor constituents, including ascorbate, protein, and sodium, potassium, and calcium ions, were analyzed in three groups of adult buphthalmic (bu/bu) rabbits from strain AXBU/J and in control rabbits of the closely related strain AX/J. Aqueous humor ascorbate concentration of the normal strain was 22.5/"2.3mg/100ml. The buphthalmic rabbits that had no meaningful clinical signs of glaucoma at the time of sample collection had lower values (11.7/"1.7mg/100ml). Much lower values were observed in the bu/bu mutant rabbits that showed mild to severe glaucoma: 8.9/"3.8mg/100 ml and 1.9"/0.4mg/100ml, respectively. It was concluded that reduction of aqueous ascorbate is a biochemical change associated with the pathological development of buphthalmia in rabbits of the AXBU/J strain. However, the exact mechanism is still unclear.

Survey of dentists' opinions on issues facing the profession

Dentists in the Seventh District Dental Society of the State of New York were surveyed for their attitudes toward selected health policy issues to determine the extent of attitudinal consensus in the professional community, the bases of significant differences of opinion, and the agreement of the local dentists with official policies of the American Dental Association. Greatest agreement among dentists was found with respect to the issues of licensure and peer review; some significant differences of opinion were found about the existence of manpower problems, expansion of dental schools, recruitment of minorities, expanded-duty auxiliaries, and fee scheduling. Most dentists favored participation in continuing education courses without examination as a requisite for licensure and even more favored peer review by the local dental society. Agreement between opinions of local dentists and official ADA policies was high on all issues except fee posting, for which local opinion was evenly divided. The formation of national policies with regard to fee posting should proceed carefully.

Falcon visual acuity

Grating acuity, the ability to resolve high-contrast square-wave gratings, was measured in a falcon and in humans under comparable conditions. This behavioral test of falcon acuity supports the common belief that Falconiformès have superb vision-the faclon's threshold was 160 cycles per degree, while the human thresholds were 60 cycles per degree. Falcon acuity, however, was much more dependent on lumanance, declining sharply with decreases in luminance.

Continuing education: attitudes, interests, and experiences of practicing dentists

This study was designed to examine the determinants of interest in formal continuing education courses of two different types, clinical and practice oriented. Major findings were (1) practice-oriented and clinically oriented courses differed in attractiveness among different segments of the dental profession, (2) interest in courses of a clinical nature was higher and more widespread throughout the proffession than was interest in management courses, and (3) half of the dentists supported mandatory continuing education for renewal of licenses, but 56% opposed a requirement that examinations in those courses be successfully completed. Interest in practice-related courses was related to age, income, use of allied health personnel, journal reading, and participation in study clubs. Clinically related courses were slightly more attractive to the sample than were practice-oriented courses, but current offerings of this type are less attractive to specialists than to general practitioners. Clinical courses generally appeal to the more active segments of the profession, and interest is associated with journal reading, participation in study clubs, and attendance at dental meetings. The appeal of clinical titles was more universal than that of management titles. Few background and practice characteristics were correlated with desire to keep up with the field, and those correlations that existed were smaller than those relating these variables to interest in practice; the only exception was specialization, as was noted above. Support for mandatory continuing education without examination as a requirement for relicensure was substantial. Further, no significant cleavages on this issue could be associated with any of the background or practice characteristics which were studied, a finding that indicate the existence of broad-based consensus in the sample.

Two-flash threshold in normal and subclassified schizophrenic groups

A normal and various subclassified schizophrenic groups ( ns = 10) were compared on two-flash threshold by a brief double staircase method and by an extensive yes-no procedure with signal-detection analytic techniques. For all groups the two techniques correlated moderately. Contrary to predictions made by Venables' arousal theory, the data obtained from the yes-no procedure showed that these schizophrenic groups performed similarly and at a lower sensitivity than the normal group.