Toward a quantitative theory of punishment.

In two experiments, pigeons' key pecking for food on concurrent variable-interval schedules was punished with electric shock according to concurrent variable-interval punishment schedules. With unequal frequencies of food but equal rates of punishment associated with the two keys and at several intensities of shock, the response and time allocation of all six pigeons overmatched the obtained relative frequency of food. The overmatching was predicted by a subtractive model of the interaction between punishment and positive reinforcement but not by two alternative models. Increases in the k and r(e) parameters of the generalized matching law could not account for the observed shifts in preference.

The law of effect and avoidance: a quantitative relationship between response rate and shock-frequency reduction.

Two experiments were conducted to investigate the quantitative relationship between response rate and reinforcement frequency in single and multiple variable-interval avoidance schedules. Responses cancelled delivery of shocks that were scheduled by variable-interval schedules. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and reinforcement frequency on single variable-interval avoidance schedules was accurately described by Herrnstein's (1970) equation for responding on single variable-interval schedules of positive reinforcement. On multiple variable-interval avoidance schedules with brief components, asymptotic relative response rate matched relative shock-frequency reduction. The results suggest that many interactions between response rates and shock-frequency reduction in avoidance can be understood within the framework of the generalized matching relation, as applied by Herrnstein (1970) to positive reinforcement.

Reinforcement and response rate interaction in multiple random-interval avoidance schedules.

Two experiments were conducted to investigate the interaction between response rate and reinforcement frequency in multiple random-interval avoidance schedules. Responses cancelled delivery of shocks that could be scheduled at different random intervals in each component. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and frequency of reinforcement was described by the same equations used by Herrnstein (1970) to describe responding with positive reinforcement.

Matching in concurrent variable-interval avoidance schedules.

After pretraining with multiple variable-interval avoidance schedules, two rats were exposed to a series of concurrent variable-interval avoidance schedules. Responses on two levers cancelled delivery of electric shocks arranged according to two independent variable-interval schedules. The ratio of responses and time spent on the two levers approximately matched the ratio of shocks avoided on each. Matching to the number of shocks received was not obtained. Concurrent variable-interval avoidance can therefore be added to the group of positive and negative reinforcement schedules that can be expressed in the quantitative framework of the matching law.

Concurrent performances: a baseline for the study of conditioned anxiety.

Three rats were trained to lever press on concurrent random interval 2-min random interval 2-min schedules of milk reinforcement. With a 5-sec changeover delay, relative response rate matched the relative reinforcement duration associated with each lever. A stimulus, during which unavoidable shocks occurred at random intervals, was superimposed on this concurrent baseline, and shifts in preference were found. However, data from this procedure were ambiguous, apparently confounded by shock-elicited response bursts. Termination of the shocks during the stimulus resulted in a rapid recovery of matching, which was preceded by a brief facilitation of responding on the less-preferred lever. The procedure was then changed to a conventional conditioned anxiety paradigm with a variable duration pre-shock stimulus. A marked shift in relative response rate towards the preferred lever was found in all three rats; that is, responding on the preferred lever was far less suppressed during the pre-shock stimulus than responding on the less-preferred lever.

[Technic of heterotopic transplantation of the small intestine in swine: reno-mesenteric transplantation]. / Une technique de transplantation hétérotopique de l'intestin grêle chez le porc: la transplantation réno-mésentérique.

The authors report a new technique of heterotopic transplantation of the small intestine : reno-mesenteric transplantation. The advantages of this technique are recalled, especially when intestinal transplantation is carried out some time after removal of the intestine. In fact, in this case, orthotopic transplantation is difficult owing to the relationship between the mesenteric stump and the fibrous scar.

[Effects of lethal overexposure on gastric secretion in the pig]. / Effets de l'irradiation aiguë à dose létale sur la sécrétion gastrique chez le porc

The characteristics of gastric secretion following acute gamma exposure (1500 rd) were studied in pigs with a small Pavlov stomach. Spontaneous secretion was practically inhibited when the animals were taken out of the irradiation cell. It slowly recovered in the following hours and its pH, first neutral, turned acid again. However, till the third day, it did not recover normal characteristics. The excretion of sodium ions was much increased. Under histaminic stimulation, the responses of irradiated pigs and controls were much similar. The secretory capacities of the gastric mucosa were retained but without spontaneous manifestations. As a conclusion, the early troubles following overexposure must be the consequences of regulation disorders rather than of the direct action of radiation on the stomach.

[Fistulation of the stomach and residual gastric contents after ingestion of a semi-purified diet of maize starch base in the pig]. / Fistulation de l'estomac et contenus gastriques résiduels après ingestion d'un régime semi-purifié à base d'amidon de maïs chez le Porc.

Gastric emptying was studied by measuring the residual gastric contents in 6 pigs weighing an average 56.5 kg and fitted with an indwelling gastric cannula in the middle of the greater curvature of the stomach. The feed offered was a semi-purified test meal, including 1 980 g of fresh matter, 880 g of dry matter, 61.9 g of total crude protein (N x 6.25), 7.1 g of soluble crude protein, 720 g of total starch (glucose and all its alpha-derivatives) and 7 g of hydrosoluble starch. These components were determined in the gastric contents collected at the following intervals after the meal: 30 min, 1 h, 2 h, 4 h, and 7 h. The inoffensiveness of stomach fistulation was checked by recording the electromyographic activities of the gastric antrum. The results on gastric emptying are given in figure 2. The total residual amounts of crude protein and starch were closely related to the amounts of dry matter. The soluble crude protein fraction increased stepwise, reaching 55 p. 100 of the total crude protein fraction 7 h after the meal. The soluble starch fraction was always less than 1 p. 100 of the total starch fraction. As calculated by difference, the amounts emptied were compared with those measured directly by collecting the duodenal contents in similar experimental conditions. This comparison of emptying kinetics showed large differences according to the technique used. Gastric emptying of dry matter was steadier and more marked within the 7-hour range when using gastric fistulation. The considerable difference also observed in the case of starch (fig. 3) may be interpreted as an underestimation of duodenal content starch because of the interference of bile pigments with H2O2 measurement in the enzyme analyses. A comparison of starch emptying kinetics with those of the absorption of reducing sugars suggested that sugar absorption might be restricted due to the velocity of starch hydrolysis by pancreatic alpha-amylase.

[Collection of digesta flowing into the large intestine after post-ileocolic valve fistulation: preliminary results]. / Obtention des digesta parvenant au gros intestin par fistulation iléo-colique post-valvulaire: note préliminaire.

The various techniques of ileocaecal reentrant fistulation now used to collect digesta flowing from the small into the large intestine, do not provide an accurate estimate of digestion in the small intestine. Their main disadvantages are: an erroneous description of the kinetics of food passage (collection proximal to the valve or bypass of the ileocaecal valve) and changes in the ileal microflora. A new surgical technique is described (fig. 1) for collecting the digesta as they have been propelled through the ileocaecal valve, thus maintaining the functional role of the valve. When using such a technique, the digesta collected into a rubber bag must be returned to the proximal colon by the investigator. Using this post-ileocolic valve fistulation technique, the disorders commonly reported with the other techniques are avoided, and a true picture of food passage at the ileocaecal valve is obtained.

A cross-sectional study of the acquisition of grammatical morphemes in child speech.

Speech samples were taken from 21 children aged 16-40 months covering a wide range of mean utterance length. Presence or absence of 14 grammatical morphemes in linguistic and nonlinguistic obligatory contexts was scored. Order of acquisition of the morphemes was determined using two different criteria. The rank-orderings obtained correlated very highly with a previously determined order of acquisition for three children studied longitudinally. Age did not add to the predictiveness of mean length of utterance alone for grammatical development in terms of which morphemes were correctly used. The approximately invariant order of acquisition for the fourteen morphemes is discussed in terms of three possible determinants of this order. Frequency of use in parental speech showed no correlation with order of acquisition, but grammatical and semantic complexity both correlated highly with acquisition order.

Development of the use of word order in comprehension.

Thirty-three children aged between 19 and 38 months were presented with six reversible active and six reversible passive sentences and were required to act them out. For each child, mean length of utterance was calculated from a sample of spontaneous speech. Mean length of utterance was a more consistent predictor of performance than chronological age. Seven children with a mean length of utterance between 1.0 and 1.5 morphemes per utterance were unable to use the word order information in either type of sentence for comprehension. More developed children could comprehend reversible active sentences but not reversible passives. Children with a mean length of utterance between 3.0 and 3.5 morphemes per utterance systematically reversed the meaning of the reversible passives. The results are discussed in relation to previous studies of word order comprehension and studies of word order in production.

Early judgments of semantic and syntactic acceptability by children.

Judgments of the acceptability of correct, word order reversed, and semantically anomalous sentences were elicited from 2- and 3-year-old children in a game played with hand puppets. All of the sentences used were simple imperatives and each child was asked to correct those he called "wrong". Performance on the judgment task was correlated with each child's mean length of utterance and with his comprehension of reversible active and passive sentences. Only the linguistically most advanced children were able to make a significant number of appropriate judgments and corrections of reversed word order imperatives. Less developed children could appropriately judge and correct semantically anomalous but not incorrect word order imperatives. The importance of semantic as opposed to syntactic factors in children's judgments of the acceptability of sentences is stressed.

[Alloantigens directed by the SL-A region control the mixed lymphocyte reaction in swine]. / Alloantigènes sous la dépendance de la région SL-A contrôlant la réaction lymphocytaire mixte chez le Porc

Immunizations between a pig bearing a recombined SL-A haplotype and related animals revealed serological defined antigens under the MLR region control. These antigens seemed to be carried by all types of lymphocytes so far studied, but with large quantitative differences. The blood nonadherent on nylon fiber lymphocytes carried very few antigens and platelets none at all. The data are compatible with the assumption that these newly discovered antigens are equivalent to the mouse Ia antigens.

[Effect of autotransplantation on various functions of the small intestine in swine].

The effects of anoxia on orthotopic small bowel autotransplantation were studied in 22 pigs respectively on the operative day (before and after transplantation) and post-operatively (on the 1st, 3d, 5th, 7th and 15th day). Absorption of D-xylose (as evaluated by xylosemia curve) and several brush border enzyme activities were compared with histological and histoenzymological data. After transplantation D-xylose test, enzymatic assays and to a lesser degree histoenzymology showed some impairment until the 15th day. By contract mucosal morphology as evaluated by optical microscopy was normalized as soon as the 3d post-operative day. From these data it may be assumed that in allotransplantations, optical microscopic abnormalities seen after the fourth post-operative day are no longer due to anoxia but may be related to early rejection. Other functional tests could be of some value only after the 15th day.

[In vivo cephalic x-ray computed tomography of the chimpanzee (Pan troglodytes, Catarhinii, Anthropomorpha) in the neuro-ocular plane]. / Tomodensitométrie céphalique in vivo du Chimpanzé (Pan troglodytes, Catarhinii, Anthropomorpha), dans le plan neuro-oculaire (P.N.O.).

A N.O.P. oriented C.T. in vivo of the head of the Pan troglodytes L. The N.O.P. was recognised from many works (E.A.C.). It permitted a biometric approach and very precise morphologic study of the brain and face in comparative anatomy.