Biomedical subjects

J H Long

Publications and source records attributed to J H Long.

17 recordsLinked to original sources

PubMed2001

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.

Adolescent↗

PubMed2000

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.

Antioxidants↗

PubMed1998

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.

Bruxism↗

PubMed1998

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.

Amino Acid Sequence↗

PubMed1997

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.

Animals↗

PubMed1995

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.

Contraindications↗

PubMed1995

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.

Journal Article↗

PubMed1993

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.

Animals↗

PubMed1992

Occlusal adjustment as treatment for tenderness in the muscles of mastication in category 1 patients.

When a lateral pterygoid muscle is more tender to palpation than the other muscles of mastication, and a stress test is positive, an occlusal cause should be suspected. Patients with lateral pterygoid tenderness are divided into three categories according to two criteria: the position of the condyles in their glenoid fossae and the degree of dysfunction in the articulation. Only patients in category 1, those with a centered condylar position and without dysfunction, are discussed in this article. Occlusal adjustment is executed on the basis of information gathered from radiographs of the temporomandibular joint, diagnostic casts, and leaf gauge measurements of unequal bilateral occlusal contact. The amount of tooth structure requiring removal can be determined by using leaf gauges of differing thicknesses. Occlusal adjustments are performed without mandibular manipulation until the tenderness of the lateral pterygoid muscle is relieved.

Dental Occlusion↗

PubMed1992

New diagnostic and therapeutic mechanical device.

A new device is described that may be used (1) diagnostically to determine the relationship of the occlusion to tenderness in the lateral pterygoid and other muscles of mastication; (2) to relieve ischemic muscle tenderness; (3) to assist in the reduction of articular clicks; and (4) as a positioning device for the registration of physiologic interocclusal relations. The rationale for the causal relationship between the occlusion and lateral pterygoid muscle tenderness is explained.

Bite Force↗

PubMed1991

Diagnostic tests used in determining the role of the occlusion in temporomandibular joint disorders.

Two diagnostic tests, positive tenderness to palpation of the inferior bellies of the lateral pterygoid muscles and a positive stress test, are helpful in determining whether the dental occlusion is a principal etiologic factor in ischemic pain in the muscles of mastication. To avoid a noxious occlusal contact, the muscles of mastication, and particularly the lateral pterygoid muscles, must increase their activity. The ability of the patient to supply the oxygen for this activity is variable. When it is inadequate, to relieve ischemic pain the muscular activity must be decreased or the oxygen supply increased. The dentist has the option of using four modalities for the treatment of these painful muscles: physiotherapy, drug therapy, psychotherapy, and occlusal therapy. When the lateral pterygoid muscles are not tender to palpation and the stress test is negative, occlusal therapy is not indicated.

Dental Occlusion, Traumatic↗

PubMed1974