TALplanner in IPC-2002: Extensions and Control Rules

TALplanner is a forward-chaining planner that relies on domain knowledge in the shape of temporal logic formulas in order to prune irrelevant parts of the search space. TALplanner recently participated in the third International Planning Competition, which had a clear emphasis on increasing the complexity of the problem domains being used as benchmark tests and the expressivity required to represent these domains in a planning system. Like many other planners, TALplanner had support for some but not all aspects of this increase in expressivity, and a number of changes to the planner were required. After a short introduction to TALplanner, this article describes some of the changes that were made before and during the competition. We also describe the process of introducing suitable domain knowledge for several of the competition domains.

Effects of hypothermic anesthesia of the feet on vibration-induced body sway and adaptation

The aim of this study was to investigate the significance of information from the plantar cutaneous mechanoreceptors in postural control and whether postural control could compensate for reduced cutaneous information by adaptation. Sixteen healthy subjects were tested with eyes open or eyes closed with hypothermic and normal feet temperature during posturography where body sway was induced by vibratory proprioceptive stimulation towards both calf muscles. The hypothermic anesthesia was obtained by cooling the subject's feet in ice water for 20 minutes. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface by a force platform during the posturography tests. The reduction of cutaneous sensor information from the mechanoreceptors of the feet significantly increased the vibration-induced torque variance mainly in the anteroposterior direction. However, the effects of disturbed mechanoreceptors information was rapidly compensated for through postural adaptation and torque variance was in level with that without anesthesia within 50 to 100 seconds of stimulation, both when standing with eyes open and eyes closed. Our findings suggest that somatosensory input from mechanoreceptors in the foot soles contribute significantly in maintaining postural control, but the sensory loss could be compensated for.

Influence of neck proprioception on vibration-induced postural sway

OBJECTIVE

Several reports have shown that the direction of the postural responses induced by vestibular stimulation is affected by the positions of the neck and torso. The aim of this study was to investigate whether the postural responses to vibratory proprioceptive stimulation of the calf muscles are affected by the position of the head and thus by proprioceptive and vestibular information from the neck and head.

MATERIAL AND METHODS

Ten normal subjects were exposed to vibratory proprioceptive stimulation of the calf muscles when the head was maintained in five different positions: in a neutral position facing forwards, with the head turned to the right or left sides or with the head tilted backwards or forwards. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface.

RESULTS

The analysis showed that only the anteroposterior body sway was significantly affected by the position of the head. The anteroposterior postural responses were primarily increased during the tests with the head tilted backwards or forwards, whereas the postural responses were unaffected by head torsion towards the sides. The lateral responses were primarily affected by vision and not by the position of the head.

CONCLUSIONS

The findings suggest that the responses evoked by vibratory proprioceptive stimulation of the calf muscles may be affected by different mechanisms, either by purely proprioceptive information or by an interaction between proprioceptive and vestibular information. Moreover, the increasing difference between the test conditions over time suggests that fatigue of the neck muscles may be one of the factors affecting the responses induced by the perturbations.

On-line monitoring of solutes in dialysate using absorption of ultraviolet radiation: technique description

PURPOSE

The aim of this work was to describe a new optical method for monitoring solutes in a spent dialysate using absorption of UV radiation.

METHOD

The method utilises UV-absorbance determined in the spent dialysate using a spectrophotometrical set-up. Measurements were performed both on collected dialysate samples and on-line. During on-line monitoring, a spectrophotometer was connected to the fluid outlet of the dialysis machine, with all spent dialysate passing through a specially-designed cuvette for optical single-wavelength measurements. The concentrations of several substances of various molecular sizes, electrical charge, transport mechanism, etc. were determined in the dialysate and in the blood using standard laboratory techniques. The correlation coefficient between UV-absorbance of the spent dialysate and concentration of the substances in the spent dialysate and in the blood was calculated from data based on the collected samples.

RESULTS

The obtained on-line UV-absorbance curve demonstrates the possibility to follow a single hemodialysis session continuously and to monitor deviations in the dialysator performance using UV-absorbance. The experimental results indicate a very good correlation between UV-absorbance and several small waste solutes removed such as urea, creatinine and uric acid in the spent dialysate and in the blood for every individual treatment at a fixed wavelength of 285 nm. Moreover, a good correlation between the UV-absorbance and substances like potassium, phosphate and beta2-microglobulin was obtained. The lowest correlation was achieved for sodium, calcium, glucose, vitamin B12 and albumin.

CONCLUSIONS

A technique for on-line monitoring of solutes in the spent dialysate utilising the UV-absorbance was developed. On-line monitoring during a single hemodialysis session exploiting UV-absorbance represents a possibility to follow a single hemodialysis session continuously and monitor deviations in dialysis efficiency (e.g. changes in blood flow and clearance). The UV-absorbance correlates well to the concentration of several solutes known to accumulate in dialysis patients indicating that the technique can be used to estimate the removal of retained substances.

Effects of hypothermic anesthesia of the feet on vibration-induced body sway and adaptation

The aim of this study was to investigate the significance of information from the plantar cutaneous mechanoreceptors in postural control and whether postural control could compensate for reduced cutaneous information by adaptation. Sixteen healthy subjects were tested with eyes open or eyes closed with hypothermic and normal feet temperature during posturography where body sway was induced by vibratory proprioceptive stimulation towards both calf muscles. The hypothermic anesthesia was obtained by cooling the subject's feet in ice water for 20 minutes. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface by a force platform during the posturography tests. The reduction of cutaneous sensor information from the mechanoreceptors of the feet significantly increased the vibration-induced torque variance mainly in the anteroposterior direction. However, the effects of disturbed mechanoreceptors information was rapidly compensated for through postural adaptation and torque variance was in level with that without anesthesia within 50 to 100 seconds of stimulation, both when standing with eyes open and eyes closed. Our findings suggest that somatosensory input from mechanoreceptors in the foot soles contribute significantly in maintaining postural control, but the sensory loss could be compensated for.

Impact of child health centre organization on parental satisfaction

The aim of this study is to describe differences in parental satisfaction with child health services under different organizational arrangements. The study had a cross-sectional design and was based on 3 largely identical surveys, involving 60 questions, performed in 1970, 1988 and 1993. The original questionnaire was developed by one of the authors in 1970. The present study analyses responses to 5 demographic questions and 12 questions regarding the content of child health services, evaluating parental satisfaction with these services. The study population in 1970 consisted of 443 parents (93% of those invited to participate) with children 6-18 months old, 1008 (82%) in 1988 and 1071 (80%) in 1993. Parents expressed more satisfaction with child health services in 1970 and 1993 compared to 1988. This pattern is not attributable to macro-level societal changes, but corresponds to changes in the organization of child health care services over the study period. The results highlight the vital question of how child health care should be organized in order to satisfy parents. The quality of child health care and parental satisfaction depend in part on the style of organization, including how much nurses with 'first-line' contacts focus on paediatric services.

Analysis of short- and long-term effects of adaptation in human postural control

The short-term (i.e., days) and long-term (i.e., months) effects of adaptation to posturography examinations were investigated in 12 normal subjects who were repeatedly examined for five consecutive days and again after 90 days. The examinations were conducted both with eyes open and closed, and the perturbations were evoked by a pseudorandomly applied vibration stimulation to the calf muscles. The evoked anteroposterior responses were analyzed with a method considering adaptation in the slow changes in posture and in the stimulus-response relationship. Repetition of examinations on a daily basis revealed a gradual improvement of postural-control performance. The body sway induced by the stimulation was significantly reduced and the dynamical properties changed. Most of the improvements remained after 90 days, but some parameters such as the complexity of the control system used were increased to the initial level. The results confirm previous observations that postural control contains several partially independent adaptive processes, observed in terms of alteration of posture and as a progressive reduction of body sway induced by stimulation. The method used for the adaptation analysis in this study could be applied to analyze biological systems with multiple individual adaptive processes with different time courses or characteristics, or where the adaptation processes are related to multiple internal or external factors.

Neck vibration causes short-latency electromyographic activation of lower leg muscles in postural reactions of the standing human

To study how quickly cervical proprioceptive information induced muscular responses in the lower leg to control posture in the standing human we investigated lower leg muscle electromyography and force-plate data from 10 healthy normal subjects, when perturbed by posterior neck muscle vibration. At the onset of vibration the tibialis anterior muscle was activated at latencies of 70-100 ms whilst the triceps surae muscle was inhibited at the same latencies. At offset the opposite pattern was observed. These findings suggest that a short-latency integrative system, rather than a direct reflex, mediates the cervical influence on posture. The short latencies also imply that activation of postural muscles in response to vibration towards the neck muscles occurs faster than would be expected if it was caused only by a perceptive illusion of movement.

Adaptation of postural control to perturbations--a process that initiates long-term motor memory

The objective was to investigate postural control adaptation during daily repeated posturography with vibratory calf stimulation. The posturography was performed with eyes open and closed daily for 5 days and after 90 days on 12 healthy subjects. The postural control adaptation could be described as two separate processes, a rapid adaptation during the test progress and a long-term habituation between consecutive test days. The adaptive improvements gained during the 5 days consecutive testing, largely remained 90 days later but seemed restricted to the same test situation. The findings suggest that balance rehabilitation should include a variety of repeated exercises, which are sufficiently long to induce habituation.

Importance of CpG dinucleotides in activation of natural IFN-alpha-producing cells by a lupus-related oligodeoxynucleotide

The oligodeoxyribonucleotide (ODN) 5'-TTTTCAATTCGAAGATGAAT-3' (ODN H), identified in systemic lupus erythematosus (SLE) serum, induced the production of interferon (IFN)-alpha in human peripheral blood mononuclear cells (PBMC) when combined with lipofectin. Flow cytometric analysis with staining for surface antigens and intracellular IFN-alpha, showed that the IFN-alpha-producing cells (IPC) were the natural IPC, also termed type 2 dendritic cell precursors (pDC2) or plasmacytoid monocytes. The importance of unmethylated CpG dinucleotides for the interferogenic activity of ODN was studied. Methylation of CpG impaired the activity of single-stranded (ss) ODN H, but increased that of the complementary ssODN I. Furthermore, CpG-methylated double-stranded (ds) ODN Hmet-Imet lost, but hemimethylated dsODN H-Imet retained interferogenic activity. Inversion of the CpG to GpC had no effect on the interferogenic activity of ssODN H, increased that of ssODN I, however abolished the activity of dsODN H-I. Alteration of the CpG in ODN H to ApG and in the ODN I to CpT destroyed their activity. The induction of IFN-alpha is therefore sequence-specific, but unmethylated CpGs are not always required, especially not in ssODNs. Interferogenic DNA sequences could therefore be more frequent in eukaryotic genomes than previously thought and their capacity to activate natural IPC may have implications for immune responses to microbial antigens and nuclear autoantigens.

Longitudinal assessment of oxygen cost and velocity in children with myelomeningocele: comparison of the hip-knee-ankle-foot orthosis and the reciprocating gait orthosis

Oxygen consumption and cost and velocity were evaluated over time in 23 children with myelomeningocele to determine whether differences exist when children walk with hip-knee-ankle-foot orthoses (HKAFOs) versus reciprocating gait orthoses (RGOs). Children using HKAFOs had similar oxygen cost as children using RGOs while achieving a faster velocity. Children walking with HKAFOs into adolescence had a faster velocity and lower oxygen cost than children who discontinued use of their HKAFOs. No significant differences in velocity or oxygen cost were found between children who continued to walk with RGOs and those who discontinued use of their RGOs. Upright ambulation may progress from ambulation with an RGO, when the child's upper extremity strength to mass ratio is low, to an HKAFO when upper extremity strength improves and velocity or keeping up with peers is of concern. Wheelchair mobility should be offered when speed and an energy-efficient method of community mobility are desired.

Multi-stimulus multi-response posturography

In this study a method for the analysis of simultaneous multiple measurements of kinematics and stabilizing forces related to human postural dynamics is proposed. Each subject in a group of normal subjects (n=10) was tested with eyes-open and eyes-closed with simultaneous but uncorrelated vestibular and proprioceptive stimuli in order to investigate the contributions of individual sensory feedback loops. Statistical analysis was made by means of multi-input multi-output identification of a transfer function from stimuli to stabilizing forces of the feet and the resulting body position, the transfer function being compatible with a biomechanical model formulated as a stabilized segmented inverted pendulum subject to feedback of body sway and position. Each individual model estimated is effective in predicting a subject's response to new stimuli and in describing the interacting effects of stimuli on body kinetics. The proposed methodology responds to the current needs of data analysis of multi-stimulus multi-response experiments.

Changes in postural control in healthy elderly subjects are related to vibration sensation, vision and vestibular asymmetry

The aim of this study was to analyze the composition of sway in adults and "healthy" elderly people and to evaluate the influence of vibration sensation and asymmetric vestibular function on the sway pattern. Ten adults with a mean age of 37.5 years and 40 healthy senior citizens with a mean age of 74.6 years living independently in the community were studied. Vibration-induced body sway was measured on a force platform. The sway was analyzed and separated into its high and low frequency components above and below 0.1 Hz, respectively. Additionally the elderly subjects were observed for the occurrence of spontaneous gaze and head shake-induced nystagmus using infrared charge-coupled device cameras and the vibration perception in the lower limbs was tested with a tuning fork. Vibration perception was the major determinant for postural control in the elderly subjects. Postural control among the elderly subjects with intact vibration perception in their lower limbs was very similar to that of the adults. The elderly subjects with impaired vibration sensation had increased high frequency sway compared to adults and the elderly subjects with intact sensation. Regardless of the strong influence of vibration sensation on postural control, asymmetric vestibular function might also be a contributing factor to postural instability in the elderly. Age per se had little effect on the outcome of the tests except that the elderly subjects had diminished ability to use visual cues to reduce postural sway. We concluded that sensory status in the lower limbs is of utmost importance for postural control in the elderly. Rehabilitation programs for senior citizens should therefore include exercises to preserve recognition of body motion by the lower limbs. Exercises to facilitate vestibular compensation could be useful for elderly people with vestibular dysfunction.

The Boeing prospective study and beyond

STUDY DESIGN

The Boeing prospective study was reviewed. The Boeing prospective study, comprising two articles, was a large field study that explored why workers would or would not report occupational back pain problems.

OBJECTIVES

The most immediate objective was to determine the extent to which conclusions drawn from the Boeing prospective study withstand critical examination. The ultimate purpose of this review was to develop guidelines for field studies of back pain in industry.

SUMMARY OF BACKGROUND DATA

For more than a century, researchers have noted great variability among individuals in the reporting of back pain, but the explanations posed for this variability have been inconsistent. Because findings gain credibility roughly to the extent that they bear on the world outside the laboratory, field studies in particular hold great potential for clarifying the underlying explanation for individual variability in back pain reporting. The Boeing prospective study was a large and ambitious field study that examined this issue.

METHODS

The Boeing prospective study was examined through the lens of research conducted since it was published. The review used both the methodological and substantive literature.

RESULTS

The Boeing prospective study, based on a minority of workers originally solicited to participate in it (33-41%), accounted for 7% of the variation in why workers would or would not report a back pain problem. A number of issues that may have biased its results toward the null are examined.

CONCLUSIONS

The highlighting of the Boeing prospective study's limitations may be instructive not so much to criticize this one particular study but, rather, to anticipate problems that in general may be encountered in field studies of back pain in industry. Looking beyond the Boeing prospective study, the following guidelines for the conduct of such studies may be proposed: 1) Study designs should be based on explanations from which testable hypotheses may be derived; 2) Subgroups within the more general category of "back pain" should be delineated; 3) Both occupational exposures and psychosocial factors should be entered into the analysis; 4) Factors not apparent at the workplace should be considered; 5. Abstracts of articles should be carefully crafted.

Effect of chronic renal failure on bone turnover and bone alkaline phosphatase isoforms

BACKGROUND

Biochemical markers of bone turnover are used to monitor metabolic bone disease associated with renal failure. We have applied a comprehensive panel of markers to patients with chronic renal failure (CRF), with particular focus on the isoforms of bone alkaline phosphatase (BALP).

METHODS

Twenty CRF patients undergoing hemodialysis (N = 9) and peritoneal dialysis (N = 11) were measured for serum parathyroid hormone (PTH), osteocalcin, total ALP, and four BALP isoforms (B/I, B1x, B1, and B2) by high-performance liquid chromatography. These BALP isoforms were also compared with BALP measured by three commercial immunoassays (Alkphase-B, Tandem-R Ostase, and Tandem-MP Ostase). Type I collagen turnover was assessed by serum samples using the type I procollagen intact amino- and carboxy-terminal propeptides (PINP and PICP) and two fragments (ICTP and CrossLaps) derived from the carboxy-terminal telopeptide of mature matrix collagen by different degradative pathways.

RESULTS

Mean levels of bone turnover markers were elevated in CRF, with marked increases in those markers, osteocalcin, ICTP, and CrossLaps, cleared by the kidney. Total ALP activities were increased corresponding to elevated B/I and B2 isoform levels. The B1 isoform level was not significantly different from healthy controls. B1x was detected in 60% of the patients but was not resolved in healthy individuals. Kendall's tau rank correlation showed that B1x correlated significantly (P < 0.05) with B1 (0.53) and PINP (0.55), and was the only marker to correlate with PTH (0.49). B1x was not significantly correlated with any of the commercial BALP immunoassays. Interestingly, the immunoassay calibrators contained high activities of the B/I peak (39 to 80%) compared with human serum (4%).

CONCLUSION

There are selective differences between the BALP isoforms in CRF compared with healthy adults. The commercial BALP immunoassays are comparable with each other but are unable to distinguish the BALP isoform-specific differences in CRF patients.

Successful treatment of retroperitoneal fibrosis with tamoxifen in a child

We describe our experience with tamoxifen in a prepubertal girl with retroperitoneal fibrosis who had failed treatment with high dose corticosteroid therapy. Her response was excellent.

A preliminary study of joint surface changes after an intraarticular fracture: a sheep model of a tibia fracture with weight bearing after internal fixation

OBJECTIVE

To evaluate the changes in the articular cartilage and subchondral bone after an osteotomy designed to simulate an articular fracture.

DESIGN

The contribution of the cartilage and subchondral bone was evaluated twelve weeks after creating a 1.0-millimeter step-off in the medial plateau of the tibia of twelve adult domestic sheep. All animals surviving were labeled with fluorescent markers for bone production, oxytetracycline (fifty milligrams per kilogram), and calcein (twelve milligrams per kilogram) nine and 11.5 weeks after surgery. The knees were loaded in compression using an Instron materials tester with pressure-sensitive film to record joint contact pressures above and below the medial meniscus.

SETTING

The studies were performed in the research laboratories of the Orthopaedic Laboratory at Harborview Medical Center in Seattle, Washington and the Madigan Army Medical Center in Tacoma, Washington.

ANIMALS

Twelve adult domestic sheep.

INTERVENTION

An intraarticular osteotomy of the medial tibial plateau with 1.0 millimeter of displacement was performed. The osteotomy was stabilized with 3.5-millimeter lag screws.

MAIN OUTCOME MEASURES

The contact pressures of the knee joint and articular histology were evaluated twelve weeks after surgery. Samples of the articular cartilage were analyzed by light microscopy and electron microscopy to evaluate the response of the articular cartilage and subchondral bone of the differential joint loading because of the irregularity in the articular surface caused by the osteotomy.

RESULTS

The knees with an intraarticular step-off had two major contact areas with an intervening zone of reduced load corresponding to the edge of the depressed fragment. Coronal histologic sections through the articular surface showed the presence of thinning and fibrillation on the high side of the step-off and some compensatory hypertrophy of the cartilage. The subchondral bone was not responsible for restoring articular congruity because the rate of bone production was similar between the low side of the articular fracture (1.85 micrometers per day) and the high side of the fracture (1.67 micrometers per day). Scanning electron microscopy showed partial cartilage remodeling by deformation of the high side cartilage with bending of the vertical collagen fibrils, even in the unloaded state.

CONCLUSIONS

In this model with a small fracture displacement (1.0 millimeter), which was less than the thickness of the articular cartilage (1.5 millimeters), the contour of the joint improved despite residual articular surface incongruency after the fracture healing.

pap genotype and P fimbrial expression in Escherichia coli causing bacteremic and nonbacteremic febrile urinary tract infection

Escherichia coli strains from patients with febrile urinary tract infections (n=73) were examined for pap genotype and P fimbrial expression in relation to bacteremia and patients' background variables. Most isolates were pap(+) by DNA hybridization (n=51), and 36 were papG(IA2)(+) and 18 prsG(J96)(+) by polymerase chain reaction. The pap and papG genotypes of the infecting strain were shown to vary with host compromise, sex, and age. Bacteremia in noncompromised patients was caused by papG(IA2)(+) strains, but compromised hosts carried a mixture of papG(IA2)(+), prsG(J96)(+), and pap(-) strains. Women of all ages were infected with papG(IA2)(+) strains. Infected men carried prsG(J96)(+) or pap(-) strains and were older, and most had compromising conditions. papG(IA2)(+) strains predominated among patients with medical illness, whereas prsG(J96)(+) strains predominated among patients with urinary tract abnormalities. These findings emphasize the strong influence of host factors on the selection of E. coli strains causing febrile urinary tract infections.

Observation of vestibular asymmetry in a majority of patients over 50 years with fall-related wrist fractures

Previously [The abstract has been shortened somewhat, and the headings removed, in order to conform to journal style], we have observed vestibular asymmetry in about one-third of healthy senior citizens and in about two-thirds of subjects with previous hip fractures and no other significant ailments. Wrist fractures are considered a harbinger of hip fractures. If vestibular asymmetry is correlated with falls and fractures among the elderly then it should also be reflected among subjects with wrist fractures. Sixty-six consecutive patients (mean age 67.8 years) who had sustained a fall-related wrist fracture during a 10-month period were included in the study. The frequency of head shake nystagmus among the patients was compared to that found among 49 healthy senior citizens (mean age 74.9 years). Nystagmus after head shaking, indicating asymmetric vestibular function, was found in 50 participants (76%) (p <0.001). Thirty-eight of these were graded with distinct or prominent nystagmus responses. Sixty percent of the subjects with horizontal nystagmus had a wrist fracture coinciding with the slow phase of nystagmus. Twenty-three subjects reported 30 previous fall-related fractures during the previous 10 years. Subjects with nystagmus after head shaking sustained 26 of these fractures. The frequency of signs of vestibular asymmetry was significantly higher (p < 0.001) among the subjects than among healthy senior citizens. These findings suggest that an asymmetric vestibular function could be an epidemiologically important contributory factor to falls and wrist fractures among the elderly population.

The effectiveness of routine health examinations at 2, 6, 9 and 12 months of age: experiences based on data from a Swedish county

AIM

The aim of this study was to elucidate the role of health surveillance for infants during the first year of life in detecting severe health problems. Two central questions were addressed: (1) what health problems were detected by routine health examinations at the Child Health Centre at the 2-, 6- and 12-month check-ups by a physician and at the 9-month check-up by a nurse; and (2) to what extent did the health examinations contribute to early identification of children with following key abnormalities: congenital heart disease, congenital dislocation of the hip, abnormalities as registered at the habilitation centre and severe hearing impairments? MATERIAL AND INCLUSION CRITERIA: The study population included all children in Uppsala county, born January 1995 to October 1996, who had participated in at least one of the four health check-ups. There were 3107-3487 children in the respective check-ups.

METHOD

Data from a county health register as well as child health records and information regarding referrals were analysed to categorize the health problems by type, severity and action taken. Data on children with key abnormalities were obtained from specialist units.

RESULTS

The rate of suspected new health problems varied between 1.9% and 2.8% at the respective check-ups. Of the new problems detected by the physician, 21%-36% were false-positive, 34%-44% were minor and 10%-15% were moderate. Only two severe health problems were detected among all the children during the four check-ups. Of all key abnormalities, 20% were detected by way of child health surveillance during the first year of life.

IMPLICATIONS

Severe health problems and key abnormalities in infants were detected only to a limited extent through routine health examinations at 2, 6, 9 and 12 months of age. The minor and moderate problems detected justify a health surveillance programme, but the organization and content of the programme could be reconsidered.

The plasmid pcDNA3 differentially induces production of interferon-alpha and interleukin-6 in cultures of porcine leukocytes

An adjuvant effect of invertebrate DNA has been attributed to its relative high frequency of unmethylated CpG dinucleotides. Here we describe the interferon-alpha (IFN-alpha) and interleukin-6 (IL-6) inducing properties of a commonly used eukaryotic expression vector, pcDNA3, in porcine leukocytes. The magnitude of the cytokine response was compared to that induced by the synthetic ds RNA analogue poly(I):poly(C), inactivated preparations of Aujeszky's disease virus (ADV) and the Gram-negative bacteria Actinobacillus pleuropneumoniae. The plasmid, as well as poly(I):poly(C), required lipofectin to induce IFN-alpha production whereas both preparations induced IL-6 irrespective of preincubation with lipofectin. However, the nucleic acid-induced levels of IL-6 were low compared to those induced by A. pleuropneumoniae. The IFN-alpha response elicited by pcDNA3 in the presence of lipofectin was as high as, or higher than that induced by ADV. Interestingly, also A. pleuropneumoniae induced a substantial production of IFN-alpha when preincubated with lipofectin. Plasmid expression was not necessary for induction of IFN-alpha. Furthermore, the IFN-alpha inducing capacity of pcDNA3 was not reduced when the two predicted immunostimulatory sequences 5'AACGTT3' were deleted. Nor did the ability of the plasmid to induce IFN-alpha production decrease when the ampicillin resistance (ampR) gene was replaced with the kanamycin resistance (kanR) gene. However, methylation of all cytidines in CpG dinucleotides of pcDNA3 abolished the IFN-alpha inducing capacity. These in vitro results indicate an immunomodulatory role of bacterial DNA also in the pig. Unmethylated CpG dinucleotides are crucial for induction of IFN-alpha by the plasmid, but other CpG motifs than those within the 5'AACGTT3' sequences of the ampR gene contribute to this induction in porcine cells.

The effects of galvanic stimulation on the human vestibulo-ocular reflex

We studied the effects of 5 mA bilateral or unilateral, bipolar or monopolar, galvanic stimulation on the horizontal vestibulo-ocular reflex (hVOR) in six normal subjects during 0.01, 0.05, 0.1, 0.5 and 1 Hz yaw rotations and in two subjects during high-acceleration, low-amplitude yaw head rotations (head impulses). Bipolar galvanic stimulation induced horizontal nystagmus in all subjects and an asymmetry of the hVOR only during rotations below 0.1 Hz. Monopolar stimulation had no significant effect. The findings suggest that in humans galvanic stimulation affects those primary horizontal semicircular canal neurons that mediate the hVOR via indirect pathways through the velocity storage mechanism.

Time structure of behavioral patterns related to feed pecking in chicks

Nonrandom time patterns of pecking acts by 16 chicks were detected using the software Theme during three videotaped pecking sessions (M, C, and A). At 15 days of age pecking session, M (mash) was recorded when chicks ate a mash diet. Pecking session C (change) at 16 or 17 days of age was recorded immediately after the change of the diet to pellets presented either as regular cylinders (P) to eight chicks, or as semiovoid (Po) to eight other chicks. Pecking session A (adapted) was recorded 5 or 6 days after adaptation to P and Po. Successful (consumatory) pecks were 72%, 52%, and 61% of all pecks for sessions M, C, and A, respectively. The head of the chicks remained in a steady position between two consecutive pecks for a longer period during C (65% of the time) than M and A (54%). During C, the pecking rate was less for P (0.54 pecks/s) than for Po (0.79 pecks/s). Two consistent time patterns involving four acts frequently observed were: head rotation (or exploratory peck)-->head in steady position-->consumatory peck-->head in steady position with jaw movements. Time intervals within a pattern were stable throughout sessions. However, the proportion of synchronized (included in a pattern) vs. nonsynchronized (not included in a pattern) acts decreased immediately after the change of feed form (session C). These results suggest that pecking at feed is composed of two distinct sets of acts: consistently organized patterns little affected by the form of the pecked particles and nonsynchronized acts that may be involved in sensory information.