Two kinds of verbal behavior plus a possible third

Speaking, writing, and signing (American Sign Language) are types of verbal behavior where each different verbal relation involves a different topography. It is also possible to behave verbally by pointing at or in some way indicating the relevant verbal stimuli, where response topographies do not differ from one verbal relation to another. There are a number of potentially important differences between topography-based and stimulus-selection-based verbal behavior, although the two are often treated as equivalent from a behavioral as well as from a traditional perspective. Selection-based verbal behavior involves a conditional discrimination whereas topography-based verbal behavior does not. In topography-based, but not in selection-based verbal behavior, there is point-to-point correspondence between response form and relevant response product. Also, effective selection-based verbal behavior requires a good scanning repertoire whereas in topography-based verbal behavior the correct response simply becomes stronger under appropriate conditions. What is traditionally referred to as receptive language training is described as quite similar from a behavioral perspective to training in selection-based verbal behavior. Given the differences between topography- and selection-based verbal behavior, the wisdom of the current rather extensive reliance on selection-based verbal behavior in language instruction for developmentally disabled clients is seriously questioned.

A behavioral perspective on college teaching

Much of the subject matter learned in college, particularly during the first two years, is taught in relatively large classes with text and lecture as the primary source of the information being learned. If students make effective and prolonged contact with these sources, they can acquire extensive verbal repertoires in many areas of knowledge. Unfortunately there are many other activities that compete for the typical student's study time. Several factors are often cited as variables that will support study behavior in competition with other activities, but the only powerful one available to the teacher is the exam grade, as it is related to the course grade. However, unless exams are clearly related to appropriate study behavior, require through and extensive coverage of the subject matter, occur frequently (preferably no less often than once a week), and are also clearly related to the course grade, even this factor will not generate prolonged and effective study behavior. Effective college teaching is essentially a form of aversive control, but if done properly the aversiveness is quite mild, and such aversive control can be responsible for the development of large and valuable intellectual repertoires.

Automatic reinforcement and automatic punishment in infant vocal behavior

Two female infants, aged 11 and 14 months, were exposed to a procedure in which an experimenter-emitted vocal response was paired with an established form of reinforcement (positive condition). One of the subjects was also exposed to a procedure in which an experimenter-emitted vocal response was paired with a neutral stimulus (neutral condition), and a procedure in which an experimenter-emitted vocal response was paired with a mild aversive stimulus (negative condition). An AB design was used with pre- and post-pairing measures. The results showed that after the positive pairing the targeted responses increased in frequency in 75% of the sessions. Responding remained constant during the neutral condition, but dropped sharply in the negative condition. These data suggest that a critical variable related to an infant's native language acquisition is the stimulus-stimulus pairing process that occurs when parents or caretakers speak to their infants.

The role of automatic reinforcement in early language acquisition

The vocal behavior of five children was recorded and analyzed during pre- and post-pairing conditions. Between these conditions there was a pairing condition where a target sound, word, or phrase was paired with an established form of reinforcement (e.g., tickling). In the first experiment all of the children emitted the targeted responses during the post-pairing condition. The results showed that the children acquired new vocal and verbal responses by pairing neutral stimuli with established forms of conditioned or unconditioned reinforcement. Perhaps the most significant aspect of these results was that new vocal responses were acquired by the children without the use of direct reinforcement, echoic training, or prompts. In the second experiment several parameters of the pairing procedure were examined. The results of the two experiments have implications for the analysis of native language acquisition, and for the development of language intervention procedures for individuals who fail to acquire language.

State notation for teaching about behavioral procedures

Complex operant procedures are not easy to describe unambiguously and several abstract notation systems have been developed for such description. Although they have not been generally adopted, such systems could be especially valuable to the teacher and student of behavior analysis, functioning like other figures and graphs as visual aids to ordinary verbal description. One of these systems, state notation, is described in some detail, and examples are provided of its use in teaching about behavior analysis.

Statistical inference for individual organism research: mixed blessing or curse?

Descriptive and inferential statistics are described as judgemental aids, stimuli to which the scientist can more easily react than to his raw experimental results. The increasing emphasis on the significance test as the main judgemental aid utilized in experimental psychology is credited with several harmful effects on experimental practice. The area known as "the experimental analysis of behavior" has so far escaped most of these harmful effects, but now we see an increased interest in the development of appropriate significance tests for individual organism research. This interest is based on the view that it is not possible to effect adequate levels of experimental control with much human applied research, and that in such cases a significance test would be quite valuable as a judgemental aid, both of which points are considered to be essentially incorrect, and if accepted, potentially harmful.

Verbal behavior

THE RECENT HISTORY AND CURRENT STATUS OF THE AREA OF VERBAL BEHAVIOR ARE CONSIDERED IN TERMS OF THREE MAJOR THEMATIC LINES: the operant conditioning of adult verbal behavior, learning to be an effective speaker and listener, and developments directly related to Skinner's Verbal Behavior. Other topics not directly related to the main themes are also considered: the work of Kurt Salzinger, ape-language research, and human operant research related to rule-governed behavior.

Economic disparity and child survival in Cambodia

Despite improvements in child survival in recent decades, levels of infant and child mortality remain unacceptably high, particularly among the poor in developing countries recovering from recent wars and civil unrests. Using information on 8498 childbirths in five years preceding the 2000 Cambodia Demographic and Health Survey, this study measured the association between economic disparity and infant mortality using multivariate Weibull regression. Results indicate that children born in the poorest 40% households were more than twice as likely to die during infancy as those born in the richest 20% households, even after controlling for pregnancy care, birth weight, household living conditions, and other factors. Children born in the middle-income households also had significantly higher mortality risks. Not receiving antenatal care and low birth weight were associated with an increased risk. Also, boys had a higher risk than girls. The study concludes that poverty is strongly negatively associated with infant survival in Cambodia.

Feet rolled over by cars: radiological and histological considerations from experiments

This study investigates the question of whether bone structures are injured when a vehicle rolls over a foot. A total of 15 detached feet from deceased persons who had donated their bodies to research were rolled over using a VW Passat station wagon. The feet were enclosed in various types of shoes. The front left tire of the vehicle, inflated to 1.8 bar and driven at walking speed, ran over the feet at a right angle to the long axis. The feet were dissected, and histological and radiological examinations were carried out. The only macroscopically well-defined abrasions of the epidermis were on the back of the foot in the area of contact with the tire and only where the foot had not been covered by a shoe. These abrasions were also well presented histologically. No injuries to the bone structures of the feet, in the form of incomplete fractures, corticalis interruptions or spongiosa compressions were ascertained, either radiologically or microradiologically.

Surface modification of titanium-based alloys with bioactive molecules using electrochemically fixed nucleic acids

A new method of surface modification for titanium (alloys) with bioactive molecules was developed with the intention of providing a new basis of implant adaptation for particular requirements of certain medical indications. Nucleic acid single strands are fixed electrochemically via their termini (regiospecifically) by growing an oxide layer on Ti6Al7Nb anodically. It could be shown that they are accessible to subsequent hybridization with complementary strands at physiological pH. Amount of nucleic acids immobilized and hybridized were determined radioanalytically using 32P-labelled nucleic acids. Stable fixation was attained at and above potentials of 4 V(SCE). Up to 4 pmol/cm2 of nucleic acid single strands could be immobilized and hybridization efficiencies up to 1.0 were reached. Hybridization efficiency was found to depend on surface density of immobilized oligonucleotides, while hybridization rates increased when MgCl2 was added. A conjugate consisting of an oligonucleotide complementary to the immobilized strand and the hexapeptide GRGDSP with RGD as an integrin recognition site was synthesized. This conjugate was able to bind to integrins on osteoblasts. It was shown that this conjugate binds to the anchor strand fixed on Ti6Al7Nb to an extent comparable with the unconjugated complementary strand.

Oral hygiene practices, periodontal conditions, dentition status and self-reported bad mouth breath among young mothers, Tanzania

OBJECTIVES

To determine the oral hygiene practices, periodontal conditions, dentition status and self-reported bad mouth breath (S-BMB) among young mothers.

STUDY PARTICIPANTS AND METHODS

This was a cross-sectional descriptive study conducted at Muhimbili National Hospital, Dar es Salaam, Tanzania. A total of 302 postpartum mothers, aged 14-44 years, were interviewed on oral hygiene practices and S-BMB using structured questionnaire. Oral hygiene, dentition and periodontal status were assessed using the Community Periodontal Index probe and gingival recessions (GR) using Williams Periodontal probe.

RESULTS

Tooth brushing practice was 99%; tongue brushing (95%), plastic toothbrush users (96%), chewing stick (1%), wooden toothpicks (76%), dental floss (<1%); and toothpaste (93%). The prevalence of plaque and gingival bleeding on probing was 100%, gum bleeding during tooth brushing (33%), calculus (99%), probing periodontal pocket depth (PPD) 4-5 mm (27%), PPD 6+ mm (3%), GR 1+ mm (27%) and tooth decay (55%). The prevalence of S-BMB was 14%; the S-BMB had higher mean number of sites with plaque compared to the no S-BMB group (P=0.04). Factors associated with S-BMB were gum bleeding on tooth brushing (OR=2.4) and PPD 6+ mm (OR=5.4).

CONCLUSION

Self-reported bad mouth breath is a cause of concern among young mothers, and associated significant factors were gum bleeding on tooth brushing and deep periodontal pockets of 6+ mm. Further research involving clinical diagnosis of bad mouth breath and intervention through oral health promotion and periodontal therapy are recommended.

CLINICAL RELEVANCE

This study provides baseline information on oral health status and the complaint on bad mouth breath which necessitates in the future need for objective assessment, diagnosis and management of bad mouth breath for enhanced social and professional interaction without embarrassment.

Magnetresonanztomographie nach Kryoablation langer Röhrenknochen im Tiermodell

PURPOSE

To describe the MR findings following cryoablation of long bones.

MATERIALS AND METHOD

Cryoablation was performed in femoral and tibial bones of 24 sheep under general anesthesia. MRI of the treated and untreated contralateral bones was performed immediately thereafter and at 2, 4 and 6 months after the cryosurgical procedure.

RESULTS

On the MRI performed immediately after cryotherapy, the lesions showed low signal intensities relative to the normal bone marrow on unenhanced T1- and T2-weighted images. At 2, 4 and 6 months after cryoablation, the lesions showed high signal intensities on STIR images, low signal intensities on T1-weighted and heterogeneous enhancement on contrast-enhanced T1-weighted MR images. The femoral lesions decreased in size from 31 +/- 3 mm immediately after the cryotherapy to 13 +/- 4 mm 6 month later and the tibial lesions from 29 +/- 7 mm to 19 +/- 4 mm.

CONCLUSION

MRI shows bone marrow lesions immediately after cryotherapy and can easily monitor healing lesions. MR imaging is suitable for following cryotherapy.

Rate of perioperative complications in thermal ablation of bone: an animal trial

INTRODUCTION

While only few data are available yet for radioablation of bone tissue, the occurrence of bone marrow embolisms during cryoablation has been documented. It was the aim of this study to assess perioperative complication rates of thermoablation in animals using state-of-the-art ablation probes.

MATERIALS AND METHODS

Eight adult sheep were placed under general anaesthesia, and using a radioprobe, thermoablation was performed on the medial side of the head of the right tibia. In addition, freezing was performed with miniature cryoprobes on both femurs and the head of the left tibia. Haemodynamic monitoring and determination of blood gases and electrolytes were done intraoperatively. The animals were killed 1 week after surgery, and the ablation sites and lung tissue examined macroscopically and microscopically.

RESULTS

None of the animals showed pathological changes in any of these parameters. Blood gases remained unremarkable throughout the operation. All eight animals showed an average drop in haemoglobin of 0.97 g/100 ml. Two animals showed fresh embolisms in the pulmonary vessels.

CONCLUSION

Experimental thermoablation of bone tissue in large animals failed to show any significant perioperative complications following surgery. The lung embolisms which did occur were not clinically relevant. The use of mini-cryoprobes or radioprobes as alternative or complementary measures for treating pathologically altered bone tissue seems viable and does not involve any undue risks.

[Changes in stability after cryosurgical treatment of long tubular bones. An animal experiment study]

The incidence of spontaneous fractures after cryosurgical treatment is described in the literature. The purpose of this study in the sheep model was to analyze the possibility of minimizing the potential risk of bone failure using a new miniature cryoprobe with minimal tissue traumatism and exact control of the ablation. In each of 24 sheep ablations at the right femur and left tibia were performed by drilling. The ablation at the femur was restricted to an area of 2 cm(2) of only one cortical bone, whereas at the proximal tibia the whole tibial plateau was included. The opposite side, which was treated with analog drillings without cryoablation, served as control. The ultimate bending strength of the femur and the ultimate compression strength of the tibia were examined 2, 4, and 6 months after the operation. After 2 months there was a significant difference ( p<0.05) in the ultimate compression strength between the treated and untreated tibiae, whereas the ultimate bending strength of the treated femora tended to be lower. After 4 and 6 months the side treated with cryosurgery was only marginally weaker than the untreated side. Spontaneous fractures were not observed during the whole experimental period. The good controllability of the freezing procedure and the low iatrogenic weakening of the bone using a modern miniature cryoprobe minimizes the risk of pathological postoperative fractures. After ablation of larger bone sections, the treated extremity should be partially unloaded or managed by osteosynthesis for at least 3 months.

Primary intestinal posttransplant T-cell lymphoma

There have been only five reported cases of primary posttransplant T-cell lymphoma. We report the first case associated with the use of sirolimus (Rapamycin, Wyeth-Ayerst, Philadelphia, PA). The patient, receiving prednisone, cyclosporine, and sirolimus treatment, developed ascites, diarrhea, and weight loss 7 months after his second renal transplant. Tissue obtained at laparotomy established the diagnosis of primary T-cell lymphoma. Latent membrane protein-1 for Epstein-Barr virus was negative, but in-site hybridization test for Epstein-Barr-encoded RNA was positive. Despite aggressive chemotherapy, the patient died 8 months posttransplant. This is the sixth reported case of primary intestinal posttransplant T-cell lymphoma, but it is the first case associated with the use of sirolimus. The incidence of posttransplant lymphoproliferative disease in patients receiving sirolimus should be studied.