Formation of Equivalence Classes Including Emotional Functions

Eleven participants in two experimental groups, DMTS-3s and DMTS-6s, trained conditional discriminations (AB, AC, CD, DE, and EF) with the potential emergence of three 6-member equivalence classes. The A stimuli (A1, A2, and A3) consisted of faces showing angry, neutral, and happy facial expressions, respectively. All participants responded in accordance with the experimentally defined criterion of 95% correct on two consecutive transitivity BF and equivalence FB test blocks. Next, participants rated the abstract D1 and D3 stimuli equivalent to the angry and happy faces (A1 and A3) on a Semantic Differential Rating Scale. A control group rated the facial stimuli and the abstract D stimuli on a similar rating scale. Results show that stimuli are more related when trained with DMTS3s than DMTS-6s. Abstract D3 stimuli rated by the DMTS-3s group deviated less from control group ratings of respective faces than ratings of all other abstract D stimuli by the two experimental groups (AU)

Geochemical and Microbial Community Attributes in Relation to Hyporheic Zone Geological Facies.

The hyporheic zone (HZ) is the active ecotone between the surface stream and groundwater, where exchanges of nutrients and organic carbon have been shown to stimulate microbial activity and transformations of carbon and nitrogen. To examine the relationship between sediment texture, biogeochemistry, and biological activity in the Columbia River HZ, the grain size distributions for sediment samples were characterized to define geological facies, and the relationships among physical properties of the facies, physicochemical attributes of the local environment, and the structure and activity of associated microbial communities were examined. Mud and sand content and the presence of microbial heterotrophic and nitrifying communities partially explained the variability in many biogeochemical attributes such as C:N ratio and %TOC. Microbial community analysis revealed a high relative abundance of putative ammonia-oxidizing Thaumarchaeota and nitrite-oxidizing Nitrospirae. Network analysis showed negative relationships between sets of co-varying organisms and sand and mud contents, and positive relationships with total organic carbon. Our results indicate grain size distribution is a good predictor of biogeochemical properties, and that subsets of the overall microbial community respond to different sediment texture. Relationships between facies and hydrobiogeochemical properties enable facies-based conditional simulation/mapping of these properties to inform multiscale modeling of hyporheic exchange and biogeochemical processes.

Salaried and fee-for-service general practitioners: is there a difference in patient turnover?

OBJECTIVE: To compare use of working hours, patient turnover, and patient characteristics in two general practitioner groups which differed in contractual arrangements and income levels (partly fee-for-service vs. salary). DESIGN: Cross-sectional study of all patient contacts during one week. PARTICIPANTS: All general practitioners (GPs) in Oslo (N = 263) with contracts with the municipality. 83% participated. MAIN OUTCOME MEASURE: Time spent in various types of work and patient turnover; the number of patients seen per hour of consultation time. RESULTS: Fee-for-service GPs worked almost exclusively with patients in their own practice, while salaried GPs spent more time out of office (consultation-based patient work constituting 55% of the working hours). The fee-for-service group registered on average 2.68 consultations per hour of patient contact (95% confidence interval: 2.51-2.84). The corresponding numbers for the salaried group were 2.37 (2.24-2.50). Salaried GPs had somewhat more telephone consultations per hour (2.01 vs 1.66 for fee-for-service GPs), leaving a picture of two GP groups with small differences in patient turnover. The two patient populations were remarkably similar and so was the general practitioners' own evaluation of the consultations. CONCLUSIONS: Over a number of years the GPs in Oslo have practised under different contractual arrangements. As a consequence of different expectations and incentives it was expected that consultation activity and patient populations had evolved differently. This proved not to be the case.

Incapacity for work in elective orthopaedic surgery: a study of occurrence and the probability of returning to work after treatment.

STUDY OBJECTIVE: The extent to which patients undergoing elective surgery for orthopaedic disorders were incapacitated for work while they were on the waiting list and whether they were able to return to work after surgery were studied. DESIGN: This was a prospective cohort study of patients admitted to hospital for elective orthopaedic surgery. Main outcome measures were occurrence of sickness certification during the waiting time, and whether those incapacitated for work at the time of surgery returned to work during the first year after treatment. Multivariate logistic regression was used to estimate adjusted odds ratios for factors influencing return to work. SETTING: Orthopaedic department in charge of all elective orthopaedic surgery in a population of 197,354 persons in central Norway. SUBJECTS: All 2803 patients admitted to hospital for chronic orthopaedic disorders in the defined population between 1 September 1988 and 31 August 1990 were included in the study. MAIN RESULTS: Of the 1333 patients who were employed, 42% had been certified sick due to the orthopaedic disorder for some period of the waiting time. Sickness benefits from the national insurance scheme (paid from the 15th day of sickness certification) had been received by 33% and were received by 29% at the time of surgery. Of 380 patients incapacitated for work at the time of surgery, 53% returned to work within the first year after surgery. Using those treated within one month of being placed on the waiting list as the reference group, the adjusted odds ratios for not returning to work during the first year after surgery were 9.2 (p < 0.0001) for those who waited more than a year for surgery, 6.2 (p = 0.002) for those waiting nine to 12 months, and 4.9 (p = 0.02) for those waiting for six to nine months. CONCLUSIONS: A high proportion of these patients were incapacitated for work, 53% of those incapacitated returned to work within the first year after surgery. The probability of returning to work after surgery is strongly influenced by the length of time on the waiting list. Waiting for more than one year, compared with immediate treatment, was associated with an adjusted odds ratio of 9.2 for not returning to work.

[Variations in the waiting time for sterilization and sterilization rate in Norway]. / Forskjeller i ventetid for sterilisering og steriliseringshyppighet i Norge.

A comparison of data from independent sources on numbers of sterilized women indicates that figures for sterilization in Norwegian hospitals are incomplete. More than 50% of the sterilized women are outpatients and nearly 50% of the inpatients are sterilized in connection with other treatment. Permanent geographical differences in sterilization rates are observed, as well as a large variation in the waiting time. We have been unable to verify a simple relation between sterilization rate and waiting time or length of waiting list.

[Being on a waiting list for sterilization--what happens?]. / På venteliste til sterilisering--hva skjer?

While waiting for sterilization at the Department of Gynaecology, University Hospital of Trondheim (Regionsykehuset), 687 women were sent a questionnaire by mail concerning the experience of waiting for surgery. At the time of asking, about 30% of the women did not need the surgery they were scheduled for. The expected waiting time has increased in recent years and is now more than two years. During the waiting period 22 women became pregnant. 15 of these pregnancies were terminated by induced abortion. The conception rate was highest during the first year on the waiting list. In order to prevent unplanned pregnancies, the capacity for sterilization must be increased until the waiting time is less than three months.

Low doses of methylphenidate (Ritalin) may alter the delay-of-reinforcement gradient.

The present study investigated effects of methylphenidate on spatio-temporal distributions of responses generated by a fixed interval 60-s schedule of reinforcement. A response panel with 20 different response locations (holes) made it possible to distinguish effects of the drug on the procedurally-correct response (correct according to the contingencies) and effects on other topographically similar responses acting as functionally-adequate responses. Detailed flow charts show how the dynamics of responding changed with dose and segment of the fixed interval. The number of holes visited was increased after low and medium doses, but decreased after high doses. The spatial differences between responses in the initial and the final parts of the fixed interval gradually disappeared after 6 mg/kg or higher doses as the functionally-adequate responses moved to earlier segments of the fixed interval. Few results could, however, be described as response rate dependent. Distributions of responses around the correct hole illustrated differences between procedurally-correct and functionally-adequate classes. The number of holes included in the latter class changed by dose in an inverted U-shaped fashion. Perseverations and stereotyped responding increased with increasing dose. Most of the effects may be described as motor stimulatory. One way of explaining the stimulatory effect is in terms of a lengthened delay-of-reinforcement gradient. The rate-dependent effect of methylphenidate on the procedurally-correct class after some doses may have been due to the combined effects of a lengthened delay gradient increasing the response rates early in the interval and interference from perseverations having their most detrimental effects on the high rates late in the interval.

Dose-response relationships for traffic noise and annoyance.

The annoyance due to road traffic noise was studied in 18 areas in five countries. A total of 1379 interviews was performed and noise measurements were made in each area. The relation between Leq and the extent of the population expressing that they were "very annoyed" was poor (rxy = 0.03). An augmentation of the number of heavy vehicles from 1000/24 hr up to greater than 3000/24 hr did not increase the extent of annoyance. The highest correlation was obtained for the maximum noise level. The dose-response relationship implies that the number of events above a certain limit will not increase the extent of annoyance: it is determined by the highest noise level from single vehicles. It is suggested that this model for the human reaction to environmental noise, which has now been demonstrated for aircraft, train, and traffic noise, should be considered for the establishment of standards.

Serum concentrations of vitamin D metabolites in exclusively breast-fed infants at 70 degrees north.

The effect of prolonged breast-feeding on the serum concentrations of vitamin D metabolites, calcium, phosphate, and alkaline phosphatase was studied longitudinally in 7 infants from Northern Norway. They were exclusively breast-fed for a median of 7 1/2 months. Three of the mothers were supplemented with vitamin D throughout lactation. All but one of the infants had 25-hydroxyvitamin D (25-OHD) levels in the rachitic range (less than 20 nmol/l) on at least one occasion. Vitamin D supplementation of the mother had no apparent effect on the infants' 25-OHD levels, but the values increased during summer. The infant who had the lowest 25-OHD levels also had decreased 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations, while the others maintained 1,25-(OH)2D levels within normal limits. 24,25-(OH)2D concentrations were undetectable when the 25-OHD levels were below 35 nmol/l, but the two metabolites were closely correlated for higher values of 25-OHD. Low 25-OHD levels were associated with decreased phosphate concentrations at 6 months. The calcium levels were normal throughout the study period of one year, as were all but two of the alkaline phosphatase values. Although none of the infants had clinical or biochemical evidence of rickets, the results suggest that the vitamin D supply from human milk is inadequate, and that routine vitamin D supplementation is advisable for breast-fed infants who are deprived of sunlight exposure.