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Capsaicin-treated rats permanently overingest low- but not high-concentration sucrose solutions.

The effect of capsaicin-induced chemical ablation of visceral afferents on 1-h liquid sucrose consumption was investigated in food-deprived rats. We first show that although 10% sucrose is permanently overconsumed by capsaicin-treated (CAPs) compared with vehicle-treated (VEHs) control rats, 40% sucrose is only overconsumed during the first but not subsequent 1-h exposures. Furthermore, one group of CAPs lost the overconsumption response at 20% when exposed to progressively increasing sucrose concentrations of 10-40%, and another group recovered the overconsumption response at 10% when exposed to a series of decreasing concentrations. Control rats ingested relatively constant volumes of sucrose over the range of 10, 15, and 20%, resulting in significantly different energy intakes. In contrast, CAPs generally showed a concentration-dependent decrease in volume intake, resulting in relatively constant energy intake. These results suggest that capsaicin-sensitive visceral afferents, likely from gastric distension and other preabsorptive sensors, provide major control over volume ingested. In the absence of these signals, rats initially overconsume, but rapidly learn to use other signals from capsaicin-resistant preabsorptive or postabsorptive sites, to control future intake. This redundant satiety system appears to be sensitive to the osmotic value or caloric content of the unfamiliar food, but only if this is above a threshold of about 15% sucrose.

Animals↗

Bumblebee search time without ultraviolet light.

Bees often facilitate pollination of important greenhouse crops. Individual bumblebees Bombus terrestris were therefore tested in an indoor flight arena to evaluate whether or not search time to find flowers was influenced by the inclusion or exclusion of ultraviolet radiation. Plastic model flowers of similar spectral properties to flowers of tomato Lycopersicon esculentum Mill. were used to evaluate bee search efficiency. The results show that bumblebees perceive when ultraviolet radiation is either removed or added to an illumination source; however, the bumblebees rapidly learn to find model flowers with equal efficiency in either illumination environment. The behavioural results are interpreted in relation to a colorimetric analysis showing how bumblebees are capable of using their visual system to forage efficiently in environments that exclude ultraviolet radiation.

Animals↗

Colour vision of the foraging swallowtail butterfly papilio xuthus

This paper demonstrates that foraging summer-form females of the Japanese yellow swallowtail butterfly Papilio xuthus have colour vision. The butterflies were trained to feed on sucrose solution placed on a disk of a particular colour in a cage set in the laboratory. After a few such training runs, a butterfly was presented with the training colour randomly positioned within an array of disks of other colours, but with no sucrose solution. The results indicate that the butterflies learn rapidly to select the training colour reliably among different colours. The training colour was also correctly selected when it was covered with neutral density filters to reduce its brightness, or even when the colour was presented together with disks of a variety of shades of grey. These results demonstrate convincingly, for the first time, that a butterfly has true colour vision.

Journal Article↗

Subareolar injection may be more accurate than other techniques for sentinel lymph node biopsy in breast cancer.

BACKGROUND: The aims of this study were to compare peritumoral injection of (99m)Tc-labeled albumin and subdermal injection of blue dye with subareolar (SA) injection of blue dye alone in terms of success of the sentinel lymph node identification rate, false negative (FN) rate, overall accuracy, and sensitivity of the two procedures. METHODS: From January 1999 to October 2002, 155 patients with localized breast cancer were treated. Patients were subdivided into two groups. In patients in group 1 (n = 115; January 1999 to December 2001), lymphoscintigraphy together with injection of vital dye was performed. In patients in group 2 (n = 40; January 2002 to October 2002), SA injection of blue dye alone was performed. RESULTS: In patients in group 1, the overall successful identification rate was 94.8%. The success rate of identifying a sentinel lymph node by a combination of the two techniques was 95%. With blue dye alone, the successful identification rate was 94.6% in patients in group 1 (subdermal) and 97.5% in group 2 (SA). The FN rate was 9% in group 1 and 0% in group 2. The overall accuracy of lymphatic mapping was 97% in group 1 and 100% in group 2. Sensitivity was 91% in group 1 and 100% in group 2. CONCLUSIONS: This study of dye-only injection into the SA plexus demonstrates a high sentinel node identification rate, absent FN rate, and rapid learning curve. On the basis of these findings, we propose that injections into the SA lymphatic plexus are the optimal way to perform dye-only lymphatic mapping of the breast.

Adult↗

Factors that may influence the implementation of nurse-centred telemedicine services.

A qualitative study of four UK telemedicine sites was carried out to explore reactions to nurse-centred telemedicine services and their possible implications. Using semistructured schedules, 36 people directly involved in these services were interviewed--25 nurses, four general practitioners, two advising medical consultants, three service managers and two researchers. Factors identified which may influence successful implementation included: early involvement of all groups affected, prior consideration of the practical implications, thorough initial equipment testing, good technical support, imaginative training and clarity of the purpose of the service. The study showed that all those involved must be prepared for the rapid learning that is implicit in the implementation of change. The challenge is to maximize the potential for the primary operator to use new techniques. In respect of nurse-centred services, the nurse must not be viewed as a technician, nor should telemedicine be seen as a substitute for an available doctor.

Clinical Competence↗

Intensive behavioral treatment for children with autism: four-year outcome and predictors.

Twenty-four children with autism were randomly assigned to a clinic-directed group, replicating the parameters of the early intensive behavioral treatment developed at UCLA, or to a parent-directed group that received intensive hours but less supervision by equally well-trained supervisors. Outcome after 4 years of treatment, including cognitive, language, adaptive, social, and academic measures, was similar for both groups. After combining groups, we found that 48% of all children showed rapid learning, achieved average posttreatment scores, and at age 7, were succeeding in regular education classrooms. Treatment outcome was best predicted by pretreatment imitation, language, and social responsiveness. These results are consistent with those reported by Lovaas and colleagues (Lovaas, 1987; McEachin, Smith, & Lovaas, 1993).

Achievement↗

Spatial orientation in 3-D desktop displays: using rooms for organizing information.

Understanding how spatial knowledge is acquired is important for spatial navigation and for improving the design of 3-D perspective interfaces. Configural spatial knowledge of object locations inside rooms is learned rapidly and easily (Colle & Reid, 1998), possibly because rooms afford local viewing in which objects are directly viewed or, alternatively, because of their structural features. The local viewing hypothesis predicts that the layout of objects outside of rooms also should be rapidly acquired when walls are removed and rooms are sufficiently close that participants can directly view and identify objects. It was evaluated using pointing and sketch map measures of configural knowledge with and without walls by varying distance, lighting levels, and observation instructions. Although within-room spatial knowledge was uniformly good, local viewing was not sufficient for improving spatial knowledge of objects in different rooms. Implications for navigation and 3-D interface design are discussed. Actual or potential applications of this research include the design of user interfaces, especially interfaces with 3-D displays.

Computer Simulation↗

Taste and olfactory processing in the brain and its relation to the control of eating.

Taste processing in primates through the nucleus of the solitary tract and the primary taste cortex is shown to represent the identity and intensity of taste inputs. In contrast, in the secondary taste cortex in the orbitofrontal area, single neurons respond to the taste of a food only if hunger is present. The neurons here reflect the reward value of taste. They show sensory-specific satiety. In addition to neurons with best responses to sweet, salt, bitter, and sour, there are separate representations of the taste of protein ("umami") and of astringency (e.g., tannic acid). In the orbitofrontal cortex, olfactory inputs converge onto neurons with taste inputs, forming representations of flavor. Neurons in this region may also respond to the sight of food and to its texture. The olfactory representation for some neurons reflects the taste association of odors; and olfactory sensory-specific satiety is represented in this part of the brain. Rapid learning of visual-to-taste associations is also a feature of the neural processing that occurs in the orbitofrontal cortex.

Animals↗

Training staff to conduct a paired-stimulus preference assessment.

Three staff members were trained to conduct stimulus preference assessments using a paired-stimulus format with 8 children with autism. Staff were trained to mastery level using brief instruction, a video model, and rehearsal with verbal feedback. Training took about 80 min per staff member. Results demonstrated that staff rapidly learned to correctly perform paired-stimulus preference assessments with children.

Adult↗

An evaluation of computer-based programmed instruction for promoting teachers' greetings of parents by name.

Although greeting parents by name facilitates subsequent parent-teacher communication, baseline measures revealed that 4 preschool teachers never or rarely greeted parents by name during morning check-in. To promote frequent and accurate use of parents' names by teachers, the effects of a fully automated computerized assessment and programmed instruction (CAPI) intervention were evaluated in a multiple baseline design. The CAPI intervention involved assessment and training of relations among parents' and children's pictures and names, and produced rapid learning of parent names. The CAPI intervention also resulted in substantial improvements in the classroom use of parents' names for 3 of the 4 teachers; however, a supervisor-mediated feedback package (consisting of instructions, differential reinforcement, and error correction) was necessary to maintain name use for 2 of those teachers. The practical strengths and limitations of computer-based teacher training are discussed.

Adult↗

A demonstration of auto-shaping with monkeys.

The Brown-Jenkins auto-shaping procedure for pigeons was found applicable to monkeys. Repeated pairings of lighted keys with reinforcement generated key-pressing behavior. The animals rapidly learned a simultaneous light-dark discrimination. The topographies of key-pressing and magazine behavior differed; the food tray was not illuminated.

Animals↗

Airflow as a discriminative stimulus.

In one experiment, pigeons were taught to discriminate airflow by having availability of reinforcement signalled by its presence and extinction signalled by its absence. After they reached criterion, some were trained on a discrimination reversal. Others were trained on an intradimensional discrimination with a low airflow velocity associated with reinforcement and a higher airflow velocity associated with extinction. All discriminations were learned rapidly, indicating that airflow velocity can function as a discriminative stimulus. In the second and third experiments, naive pigeons were trained to discriminate the presence of a compound stimulus (one of three tonal intensities paired with one of three airflow velocities) from its absence. These pigeons were subsequently given a component stimulus test during extinction on four stimulus values; the two training values, the tone alone, and the airflow alone. High or moderate velocity airflow controlled more responding than any of the three tone intensities. However, low velocity airflow controlled more responding only when a low intensity tone was employed.

Journal Article↗

Pigeons' wait-time responses to transitions in interfood-interval duration: Another look at cyclic schedule performance.

Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast-acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed-time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step-down) or increasing from 15 to 45 s (step-up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood-interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step-up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood-interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions-discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood interval alone.

Journal Article↗

The development of the obligatory education and certification programme of the Royal Australian College of Obstetricians and Gynaecologists: a practical response to the increasing challenges of a modern society.

A career in medicine should involve a commitment to a lifetime of learning. Rapid advances in medical knowledge, as well as the increasing knowledge and sophistication of consumers, make this commitment more important than ever before. The establishment of a new Specialist College in Australia in 1979 provided the opportunity to frame Articles which made this commitment obligatory for those who wished to continue as Fellows in the new College. The implementation of this philosophy called for a wide ranging involvement of all obstetricians joining the College, to ensure that the final form of the programme would reflect their collective views on the major issues raised by obligatory Continuing Medical Education. The development of this programme could serve as a model for other Specialist Colleges facing this increasingly important issue.

Australia↗

[A comparison of win-shift and win-stay performance of rats in a radial arm maze].

The purpose of the present experiment was to compare the performance of rats in a win-shift task and a win-stay task in a radial arm maze. To this end, three experiments were conducted using a variety of procedures. In general, the win-shift task required the rats to choose the unvisited arms and the win-stay task required the rats to return the visited arms. In Experiment 1, a free-choice memory recognition procedure was used, and in Experiments 2 and 3, a forced-choice memory recognition procedure was used. All three experiments showed that in the win-shift task, rats rapidly learned the task and performed well whereas in the win-stay task, the rats consistently showed a chance-level performance despite of the prolonged training. In addition to these findings, when the tasks were reversed (i.e. from the win-shift to the win-stay, and vice versa), the rats still showed a response strategy previously adopted (Experiment 3). These findings seem to be important in considering the characteristics of spatial memory in rats.

Animals↗

Smart technology improves patient-controlled analgesia: a preliminary report.

UNLABELLED: A new adaptive system has been designed to improve patient-controlled analgesia through the use of a variable bolus dose and a variable background infusion of analgesic. A novel hand set allows patients to rate their own pain on a linear scale of 1 to 10. Data derived from the hand set signals are used by an expert algorithm to repeatedly adapt the drug dosage of the bolus and of the background infusion according to both current pain intensity and the patient's response to previous dosage. To test the system, we performed a small pilot clinical study, using a randomized, double-blinded, cross-over design. The new system was alternated with a conventional system every 12 h. Use of the new system was associated with significantly lower pain scores and fewer bolus requests but more analgesic administration, though without increased adverse effects. It was very well accepted by both patients and clinical staff. IMPLICATIONS: Pain relief after surgery is often best provided by patient-controlled analgesia, which uses an IV infusion pump and a patient-activated switch. We have developed a new computer-controlled or "smart" patient-controlled analgesia that rapidly learns a patient's individual needs and provides continuously tailored pain relief.

Adolescent↗

Scrub jays (Aphelocoma coerulescens) form integrated memories of the multiple features of caching episodes.

Four experiments examined whether food-storing scrub jays remember when and where they cached different foods. The scrub jays cached and recovered perishable and nonperishable foods in visuospatially distinct and trial-unique cache sites. They rapidly learned to avoid searching for foods that had perished by the time of recovery, while continuing to search for the same foods after shorter retention intervals when the foods were still fresh. The temporal control of searching at recovery was also observed when the familiarity of cache sites did not provide any information about the time of caching and when the same food was cached in distinct sites at different times. The authors argue that the jays formed an integrated memory for the location and time of caching of particular foods.

Animals↗

Discriminated conditioned taste aversion for studying multi-element stimulus control.

The effects of morphine pre-treatment interval on the stimulus control exerted by a multi-element stimulus consisting of morphine (5.6mg/kg), saccharin (0.2%, w/v), and a ball-bearing drinking nozzle in a discriminated taste aversion procedure were examined. In this discriminated aversion procedure, rats received injections of LiCI following presentation of this multielement stimulus, and injections of saline following the saline, water, and non-ball-bearing nozzle composite stimulus. These paired rats were compared to unpaired rats that received saline injections rather than LiCI injections following presentation of the multi-element stimulus. Morphine pre-treatment times of 5, 10, and 20min were examined in groups of 12 paired and 6 unpaired rats. The discrimination was rapidly learned under all three pre-treatment intervals. In subsequent testing with each individual stimulus element and combinations of two stimulus elements, stimulus control was clearly exerted by both morphine and saccharin. Paired rats drank less saccharin than unpaired rats, and less saccharin than water. Similarly, paired rats drank less fluid following morphine administration than following saline administration, and less fluid than unpaired rats following morphine administration. Control by the nozzle type was also apparent in significant interactions between the nozzle and morphine or saccharin and pairing with LiCI. In general, pre-treatment time did not influence the stimulus control that developed. However, at the two shorter pre-treatment times there was some indication that a conditioned taste aversion to morphine was developing in the unpaired rats. These experiments indicate that such discriminated taste aversion procedures may be viable methods for studying the contextual control of how drugs function as discriminative stimuli, and that longer drug pre-treatment times may be desirable in such procedures.

Journal Article↗