Recognition of facial affect by children and adolescents diagnosed with social phobia

This study compared the ability of children with social phobia and children with no psychiatric disorder to accurately judge facial affect. Fifteen children and adolescents with social phobia and 14 control children were asked to identify emotions depicted in slides from the Pictures of Facial Affect. In addition, they rated their level of anxiety on a pictorial Likert scale prior to and upon completion of the facial recognition task. The results indicated that children with social phobia had significantly poorer facial affect recognition skills than normal controls and reported greater anxiety upon completion of the recognition task. Multivariate analysis revealed significant differences between groups in the number of errors based on the type of facial affect. Posthoc analysis indicated that deficits were most pronounced for facial representations of happiness, sadness, and disgust. The results are discussed in relation to an integrated model of social skills training that includes facial affect recognition training as a integral component in treatment programs for children and adolescents with social phobia. Directions for future research with larger samples of more ethnically diverse children and adolescents are presented.

Effects of Maturity and Determinacy in Soybean on Host-Parasite Relationships of Heterodera glycines

The effects of soybean maturity and determinacy on the host-parasite relationships of Heterodera glycines were investigated in a field microplot study over 2 years. Determinate and indeterminate isolines of the maturity group (MG) III cultivar Williams 82 and the MG V cultivar Essex were grown in microplots artificially infested with a race 3 isolate of H. glycines at three initial population (Pi) densities (0, 300, and 3,000 eggs/100 cm(3) soil). Soybean seed yields, nematode final population (Pf) densities and reproductive index (Pf/Pi), and root colonization by Macrophomina phaseolina, the causal agent of charcoal rot, were monitored in each year. Seed yields were reduced (P </= 0.05) in the presence of H. glycines in both years, but losses were greater in 1996 in the absence of drought stress. Yield loss was lower (P </= 0.06) for the determinate isoline of Essex than for the other cultivar-isoline treatments across years. Nematode reproduction was density-dependent in the more conducive environment of 1996 but was unaffected by soybean maturity or determinacy traits. Root colonization by M. phaseolina increased (P </= 0.05) in the presence of high H. glycines densities on determinate, but not indeterminate, isolines. Differences in H. glycines-induced yield loss among cultivar-isoline treatments were not related to nematode reproduction, M. phaseolina colonization, or environmental stresses. These results indicate that the effects of soybean maturity and determinacy on H. glycines-soybean interactions are not independent and that their combined effects must be considered in geographic regions where both traits vary.

Field assessment of plant derivative compounds for managing fungal soybean diseases

Natural plant-derived compounds are currently being explored as alternatives for pest control in sustainable agriculture. This study explored the use of two compounds, sesamol and carbenoxolone, in the management of the fungal soybean disease charcoal rot (Macrophomina phaseolina). Previous studies have determined that sesamol and carbenoxolone compounds significantly inhibited fungal pathogen growth and plant disease in vitro. In order to assess the field efficacy of these compounds for fungal disease control, 2 years of field testing of these compounds have been conducted in southeast Kansas. Field treatments of the compounds sesamol and carbenoxolone at three concentrations, 0, 500 and 1000 microg/ml, were applied foliarly at four distinct plant developmental stages. Treatments were applied to plots in random triplicate array and the experiment was repeated during the 1998 and 1999 growing seasons. Disease assessments were based on visual disease ratings, plant mortality and soybean yield analysis. Data were recorded weekly for each treatment plot and statistically analysed using analysis of variance. Results indicate that sesamol and carbenoxolone treatments significantly decreased disease symptoms (11-12%) and plant mortality (24-28%) while significantly increasing soybean yields (18-38%). These results support that plant-derived compounds can have a significant impact on soybean disease management and yield under field conditions.

Mechanics of the fast-start: muscle function and the role of intramuscular pressure in the escape behavior of amia calva and polypterus palmas

The fast-start escape response is a rapid, powerful body motion used to generate high accelerations of the body in virtually all fishes. Although the neurobiology and behavior of the fast-start are often studied, the patterns of muscle activity and muscle force production during escape are less well understood. We studied the fast-starts of two basal actinopterygian fishes (Amia calva and Polypterus palmas) to investigate the functional morphology of the fast-start and the role of intramuscular pressure (IMP) in escape behavior. Our goals were to determine whether IMP increases during fast starts, to look for associations between muscle activity and elevated IMP, and to determine the functional role of IMP in the mechanics of the escape response. We simultaneously recorded the kinematics, muscle activity patterns and IMP of four A. calva and three P. palmas during the escape response. Both species generated high IMPs of up to 90 kPa (nearly 1 atmosphere) above ambient during the fast-start. The two species showed similar pressure magnitudes but had significantly different motor patterns and escape performance. Stage 1 of the fast-start was generated by simultaneous contraction of locomotor muscle on both sides of the body, although electromyogram amplitudes on the contralateral (convex) side of the fish were significantly lower than on the ipsilateral (concave) side. Simultaneous recordings of IMP, escape motion and muscle activity suggest that pressure change is caused by the contraction and radial swelling of cone-shaped myomeres. We develop a model of IMP production that incorporates myomere geometry, the concept of constant-volume muscular hydrostats, the relationship between fiber angle and muscle force, and the forces that muscle fibers produce. The timing profile of pressure change, behavior and muscle action indicates that elevated muscle pressure is a mechanism of stiffening the body and functions in force transmission during the escape response.

A device to prevent jaw clenching

This article describes a device that is intended to prevent the clenching of the teeth. The principle involved is that to clench the teeth for an extended period, an intraoral vacuum must be formed and maintained. A tube or drinking straw held between the lips extending out of the mouth will prevent a vacuum. The article explains and illustrates how such a device can be made that will exploit this principle. Disadvantages and advantages are discussed.

Characterization of ADG1, an Arabidopsis locus encoding for ADPG pyrophosphorylase small subunit, demonstrates that the presence of the small subunit is required for large subunit stability

Two mutants of Arabidopsis have been isolated that affect ADPG pyrophosphorylase (ADGase) activity. Previously, it has been shown that ADG2 encodes the large subunit of ADGase. This study characterizes the adg1 mutant phenotype and ADG1 gene structure. RNA blot analyses indicate that the adg1-1 mutant accumulates transcripts encoding both the large and small subunits of ADGase, while the adg1-2 mutant accumulates only large subunit transcripts. RFLP analysis and complementation of adg1 mutants with the ADGase small subunit gene demonstrate that ADG1 encodes the small subunit. Sequence analysis indicates that adg1-1 represents a missense mutation within the gene. Western blot analysis confirms that adg1 mutants contain neither the large nor the small subunit proteins, suggesting that the presence of functional small subunits is required for large subunit stability.

Locomotor design of dolphin vertebral columns: bending mechanics and morphology of Delphinus delphis

The primary skeletal structure used by dolphins to generate the dorsoventral bending characteristic of cetacean swimming is the vertebral column. In the vertebral column of the saddleback dolphin Delphinus delphis, we characterize the static and dynamic mechanical properties of the intervertebral joints, describe regional variation and dorsoventral asymmetries in mechanical performance, and investigate how the mechanical properties are correlated with vertebral morphologies. Using a bending machine that applies an external load (N m) to a single intervertebral segment, we measured the resulting angular deformation (rad) of the segment in both dorsal extension and ventral flexion. Intervertebral segments from the thoracic, lumbar and caudal regions of the vertebral column were tested from five individuals. Using quasi-static bending tests, we measured the initial (low-strain) bending stiffness (N m rad-1) as a function of segment position, direction of bending (extension and flexion) and sequential cutting of intervertebral ligaments. We found that initial bending stiffness was significantly greater in the lumbar region than in adjacent thoracic and caudal regions, and all joints were stiffer in extension than is predicted (r2 = 0.554) by the length and width of the intervertebral disc and the length of the cranial vertebral body in the segment. Stiffness in flexion is predicted (r2 = 0.400) by the width of the nucleus pulposus, the length of the caudal vertebral body in the segment and the height of the transverse processes from the ventral surface of the vertebral body. We also performed dynamic bending tests on intervertebral segments from the lumbo-caudal joint and the joint between caudal vertebrae 7 and 8. Dynamic bending stiffness (N m rad-1) increases with increasing bending amplitude and is independent of bending frequency. Damping coefficient (kg m2 rad-2 s-1) decreases with increasing bending amplitude and frequency. Resilience (% energy return) increases from approximately 20% at low bending amplitudes (+/-0.6 degree) to approximately 50% at high bending amplitudes (+/-2.9 degrees). Based on these findings, the dolphin's vertebral column has the mechanical capacity to help control the body's locomotor reconfigurations, to store elastic energy and to dampen oscillations.

Field Response of Soybean in Maturity Groups III-V to Heterodera glycines in Kansas

Soybean cultivars from maturity groups III-V were grown in Heterodera glycines-infested locations in northeastern and southeastern Kansas from 1991 through 1994. Yield performance and nematode reproduction were significantly (P <0.01) affected by host response to H. glycines and year, whereas effects of cultivars within host response categories and cultivar x year interactions were generally negligible. In northeastern Kansas, H. glycines-susceptible cultivars from maturity groups III-IV yielded 8% less than resistant cultivars across years, whereas in southeastern Kansas, susceptible cultivars from maturity groups IV-V yielded 38% less than resistant cultivars across years. Analyses of yield components suggested that number of pods per plant accounted for most of the differences in seed yields. Heterodera glycines reproduction rates (final population density/initial population density) averaged 0.7 and 1.3 for resistant cultivars and 8.7 and 15.9 for susceptible cultivars in northeastern and southeastern locations, respectively. Results indicated that the relative performance of resistant and susceptible cultivars can be reliably predicted based on preplant egg densities across most environments in eastern Kansas.

Mechanical control of swimming speed: stiffness and axial wave form in undulating fish models

The purpose of this study was to investigate the mechanical control of speed in steady undulatory swimming. The roles of body flexural stiffness, driving frequency and driving amplitude were examined; these variables were chosen because of their importance in vibration theory and their hypothesized functions in undulatory swimming. Using a mold of a pumpkinseed sunfish Lepomis gibbosus, we cast three-dimensional vinyl models of four different flexural stiffnesses. We swam the models in a flow tank and powered them via the input of an oscillating sinusoidal bending couple in the horizontal plane at the posterior margin of the neurocranium. To simulate the hydrodynamic conditions of steady swimming, drag and thrust acting on the model were balanced by adjusting flow speed. Under these conditions, the actuated models generated traveling waves of bending. At steady speeds, the motions of the ventral and lateral surfaces of the model were video-taped and analyzed to yield the following response variables: tail-beat amplitude, propulsive wavelength, wave speed and depth of the trailing edge of the caudal fin. Experimental results showed that changes in body flexural stiffness can control propulsive wavelength, wave speed, Froude efficiency and, in consequence, swimming speed. Driving frequency can control tail-beat amplitude, propulsive wavelength, Froude efficiency, relative rate of working and, in consequence, swimming speed. Although there is no significant correlation between rostral amplitude and swimming speed, rostral amplitude can control swimming speed indirectly by controlling tail-beat amplitude and relative power. Compared with live sunfish using undulatory waves at the same speed, models have a lower Froude efficiency. On the basis of the mechanical control of swimming speed in model sunfish, we predict that, in order to swim at fast speeds, live sunfish increase the flexural stiffness of their bodies by a factor of two relative to their passive body stiffness.

Interocclusal splint designed to reduce tenderness in lateral pterygoid and other muscles of mastication

When a patient has discomfort in the muscles of mastication, a palpation test of the lateral pterygoid muscles is positive, and a stress test is positive, the dental occlusion may be a partial cause. The resin splint described here is designed to permit interocclusal contact exclusively at the center of the arches. This device has been shown to reduce tenderness in the lateral pterygoid and other muscles of mastication quickly, usually in 5 to 10 minutes. The splint and its advantages and disadvantages are described.

Kinematics of birdsong: functional correlation of cranial movements and acoustic features in sparrows

The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza georgiana). These birds are closely related emberizine sparrows, but their songs differ radically in frequency and amplitude structure. We found that the acoustic frequencies of notes in a song have a consistent, positive correlation with beak gape in both species. Beak gape increased significantly with increasing frequency during the first two notes in Z. albicollis song, with a mean frequency for note 1 of 3 kHz corresponding to a gape of 0.4 cm (a 15 degrees gape angle) and a mean frequency for note 2 of 4 kHz corresponding to a gape of 0.7 cm (a 30 degrees gape angle). The relationship between gape and frequency for the upswept third note in Z. albicollis also was significant. In M. georgiana, low frequencies of 3 kHz corresponding to beak gapes of 0.2-0.3 cm (a 10–15 degrees break angle), whereas frequencies of 7–8 kHz were associated with flaring of the beak to over 1 cm (a beak angle greater than 50 degrees). Beak gape and song amplitude are poorly correlated in both species. We conclude that cranial kinematics, particularly beak movements, influence the resonance properties of the vocal tract by varying its physical dimensions and thus play an active role in the production of birdsong.