Dextromethorphan and dextrorphan in rats: common antitussives--different behavioural profiles

Patients with complete unilateral cleft lip and palate present difficult growth problems. Their anteroposterior discrepancies in jaw and dentition are frequently so severe that some epidemiologic studies report the necessity of orthognathic surgery in 25% of their sample. The aims of this study were three-fold: (1) to delineate diagnostic measures in borderline surgical cases of unilateral cleft lip and palate, (2) to verify the significance of negative overjet as a measure of anteroposterior discrepancy, and (3) to compare these diagnostic measures with those of borderline surgical cases of noncleft Class III malocclusions. The sample consisted of 29 patients with unilateral cleft lip and palate and 25 noncleft Class III Korean patients (mean age, 18.69 years); all had crossbites of all four incisors. Each of their pretreatment study casts and cephalograms were analyzed. The group with unilateral cleft lip and palate was divided into two subgroups on the basis of the method of their anterior crossbite resolution; 18 subjects were treated with orthodontics alone (Cleft-NS) and 11 subjects with orthognathic surgery (Cleft-Surg). The noncleft Class III group was divided into two subgroups; 6 of the subjects were orthodontically treated (Cl III-NS), and 19 were surgically treated (Cl III-Surg). The group with unilateral cleft lip and palate showed smaller SNA and SNB angles than the noncleft Class III group, but the ANB angles and the amount of anterior crossbites showed no statistical differences. When the Cleft-NS and the Cleft-Surg groups were compared, the ANB angle and the Wits measurements were significantly different. When the Cl III-NS and Cl III-Surg groups were compared, the SNB, ANB, L1GoGn, Wits, and the crossbite showed significant differences. For borderline surgical Class III unilateral cleft lip and palate cases, ANB angle, Wits appraisal, and ABGoGn angle were critical diagnostic parameters. On the other hand, the magnitude of anterior crossbite, the negative overjet, was shown not to be a significant measure of anteroposterior discrepancy.     

Lead in the blood and protoporphyrin levels in erythrocytes in glass workers exposed to lead]

The craniofacial cephalometric dimensions, angles and dimensional ratios of five Finnish individuals with complete testicular feminization (CTF) were compared with their first-degree relatives and population female and male controls. The linear and angular measurements were made from standardized lateral cephalograms of patients and normal population controls from the 'Kvantti Study' series. The women with CTF tended to have cranial base and maxillary complex dimensions between those of the normal control females and males. Their mandibular corpus was found to be longer than in normal control females, while their ramus was shorter compared with that of normal males. They also showed a smaller sagittal length ratio of the maxilla to the mandible, a smaller ANB angle and a more acute gonial angle than in both normal control females and males. Comparison of the women CTF with their first-degree female relatives showed basically the same trends as when comparing them with normal female controls. As the phenotype in these females with CTF is due to insensitivity to, or lack of androgens, it is suggested that the presence of the Y chromosome in these females leads to craniofacial dimensions between those of normal females and males which influences the growth of the mandibular corpus. This follows the same general metric pattern that is observed in many of their adult head and body dimensions as well as in their dental arches.     

The correlation between surface measurement of head and neck posture and the anatomic position of the upper cervical vertebrae

STUDY DESIGN: Repeated measurements were made of surface postural angles registering the relative positions of the head and neck in photographs and of angles of the upper cervical vertebrae recorded in lateral cephalometric radiographs in the same subjects. For all registrations, subjects assumed the natural head rest position. OBJECTIVES: To examine the correlation between external measurement of head and neck posture and the anatomic positions of the upper four cervical vertebrae. SUMMARY OF BACKGROUND DATA: Interpretation of surface cervical posture measurement is confounded by lack of knowledge about the extent of the underlying compensatory adjustments among the upper cervical vertebrae that may accompany variation in head and neck posture. The correlation between surface measurement and postural characteristics of the upper cervical spine has not been reported to date. METHODS: The association between a set of angles describing the anatomic position of the four upper cervical vertebrae on lateral cephalometric radiographs and a surface measurement of head and neck posture, the craniovertebral angle, was studied in 34 young adult women aged between 17.2 and 30.5 years, mean age, 24.5 years. Anatomic positions of the upper four cervical vertebrae were expressed by angles relative to the true vertical or horizontal. Surface angles registering head and neck position for each subject were obtained from photographs recorded on two occasions. RESULTS: No strong correlation could be established between the angles taken from the lateral cephalometric radiographs measuring the extent of upper cervical lordosis, orientation of the atlas, vertebral inclination, or odontoid process tilt and surface angles recording head and neck position. This finding was attributed principally to the much greater positional variability demonstrated within the upper cervical spine when compared with the surface measurements of head and neck position. CONCLUSION: Anatomic alignment of the upper cervical vertebrae cannot be inferred from variation in surface measurement of head and neck posture. This is the case even in those people identified with more extreme head and neck postural tendencies.     

Kinematic data on primate head and neck posture: implications for the evolution of basicranial flexion and an evaluation of registration planes used in paleoanthropology

Kinematic data on primate head and neck posture were collected by filming 29 primate species during locomotion. These were used to test whether head and neck posture are significant influences on basicranial flexion and whether the Frankfurt plane can legitimately be employed in paleoanthropological studies. Three kinematic measurements were recorded as angles relative to the gravity vector, the inclination of the orbital plane, the inclination of the neck, and the inclination of the Frankfurt plane. A fourth kinematic measurement was calculated as the angle between the neck and the orbital plane (the head-neck angle [HNA]). The functional relationships of basicranial flexion were examined by calculating the correlations and partial correlations between HNA and craniometric measurements representing basicranial flexion, orbital kyphosis, and relative brain size (Ross and Ravosa [1993] Am. J. Phys. Anthropol. 91:305-324). Significant partial correlations were observed between relative brain size and basicranial flexion and between HNA and orbital kyphosis. This indicates that brain size, rather than head and neck posture, is the primary influence on flexion, while the degree of orbital kyphosis may act to reorient the visual field in response to variation in head and neck posture. Regarding registration planes, the Frankfurt plane was found to be horizontal in humans but inclined in all nonhuman primates. In contrast, nearly all primates (including humans) oriented their orbits such that they faced anteriorly and slightly inferiorly. These results suggest that for certain functional craniometric studies, the orbital plane may be a more suitable registration plane than Frankfurt "Horizontal."     

Bulk effect of rotator cuff on inferior glenohumeral stability as function of scapular inclination angle: a cadaver study

Eleven fresh cadaver shoulders were studied to determine the static contribution (bulk effect) of the rotator cuff on inferior glenohumeral stability provided by scapular inclination. All musculature, including the rotator cuff, was removed. The position of the humerus relative to the scapula was recorded using an electromagnetic tracking device under conditions of no force and 1.5 kg of inferior translation force applied to the humerus, with the arm in the hanging position (sulcus test) and then in 90 degrees abduction (Abduction-Inferior Stability test = ABIS test), with the scapula inclined referable to the vertical line at -15 degrees, 0 degrees, 15 degrees and 30 degrees in the sulcus test and at 15 degrees, 30 degrees, 45 degrees and 60 degrees in the ABIS test. In the sulcus test without load, all shoulders dislocated at scapular inclination angles of -15 degrees and 0 degrees, whereas no shoulders dislocated at 30 degrees. The angle of scapular inclination had a significant effect on humeral head positions (p < 0.0001), with the head position at -15 degrees and 0 degree being lower than at 15 degrees, which was lower than at 30 degrees. In the ABIS test, none of the shoulders dislocated, although the effect of the angle of scapular inclination was significant (p < 0.0001), with the position of the humeral head being higher at 15 degrees than at other angles of inclination. Comparison of these data and previously reported data with the cuff intact showed no significant effect of rotator cuff removal on humeral head position and displacement in both tests. Therefore, we conclude that the static condition of the rotator cuff has no significant effect on the stabilizing function of scapular inclination. The stabilizing mechanism of scapular inclination seems to be associated with the bony configuration and/or anatomy and biomechanical properties of the superior capsuloligamentous structures.     

A single metric for quantifying biomechanical stress in repetitive motions and exertions

The relative effects of repetition, force and posture were studied in order to investigate how continuous biomechanical measurements can be combined into a single metric corresponding to subjective discomfort. A full factorial experiment was conducted involving repetitive wrist flexion from a neutral posture to a given angle against a controlled force. Seven subjects performed the task using two paces (20 and 4 motions/min), two force levels (15 and 45 N) and two angles (15 and 45 degrees) for 1 h each. Discomfort was reported on a 10 cm visual analogue scale anchored between 'no discomfort' and 'very high discomfort'. Repeated measures analysis of variance showed that all main effects were statistically significant (p < 0.05) and no significant interactions were observed. A linear regression model was fitted to the data and used for generating frequency weighted digital filters that shape continuous recordings of repetitive motions and exertions into an output proportional to relative discomfort. The resulting high-pass digital filter had a 22 dB/decade attenuation slope. A simulated industrial task used for validating the model involved repetitively transferring pegs across a horizontal bar and inserting them into holes against a controlled resistance. Angular wrist data were recorded using an electrogoniometer and filtered. Six subjects performed the task of the three conditions consisting of (1) 15 wrist flexion, 15 N resistance and 6 motions min, (2) 15 wrist flexion. 45 N resistance and 12 motions/min, and (3) 45 degrees wrist flexion, 45 N resistance and 15 motions/min. Subjective discomfort was reported after performing the task for 1 h. Pearson correlations between subjective discomfort ratings and the integrated filtered biomechanical data for individual subjects ranged from 0.90 to 1.00. The pooled correlation across subjects was 0.67. This approach may be useful for physical stress exposure assessment and for design of tasks involving repetitive motions and exertions.     

三线切分时影响棒材张开角的几个因素

为稳定小规格带肋钢筋的三线切分轧制 ,对涉及棒材张开角的切分孔孔型诸角度进行了分析 ,通过对轧件受力状态的讨论 ,提出了诸因素与棒材张开角之间的解析式 ,指出满足三线切分稳定轧制时的棒材张开角应为 2°～ 3°,相应的孔型切分角为 30°左右 ,孔型外侧壁倾角应在 4 5°～ 5 0°之间 ,咬入角可控制在 7°～ 8°之间等。     

The use of Taguchi's methods for the evaluation of industrial knife design

Knives are used in industry, and particularly on meat packaging assembly lines, where a premium is placed on the speed of cutting. One consequence of this is that knife design and selection has been based on the speed of cutting as the most significant measure of a knife. In industry the cuts that knives make vary in difficulty with many factors such as thickness, contour, and temperature of the material being cut. These factors may change the speed with which these cuts are made. According to Taguchi's methods, a robust design is one that maintains high performance while remaining insensitive to changes in its environment. This means that a robust knife design would enable an employee to cut not only with as much speed as possible in one particular cutting scenario, but also with a consistently high speed in as many cutting scenarios as possible. An experiment with various knife designs was evaluated with Taguchi's method. Ten subjects cut outlined clay patterns in 15 min with each one of nine different knives. The nine different designs were generated from the following combinations; three grip sizes (44.4, 50.8 and 63.5 mm), three coupling angles between the grip and the blade (0, 45 and 90 degrees), three blade heights measured from the middle of the blade (10, 13 and 15 mm), and three blade lengths (85, 125 and 155 mm). Eight conditions of cutting material were used to generate 'noise'. They are combinations of temperature of the clay to be cut (from temperature (R) approximately 25 degrees C, frozen for 1 h (F) approximately 5 degrees C), thickness of the clay to be cut (15 and 25 mm), and orientation of the work surface (0 and 30 degrees). The result shows that the knife design of 63.5 mm grip size, 0 degree coupling angle, 13 mm blade height, and 85 mm blade length provides the highest number of cuts, the knife design of 50.8 mm grip size, 45 degrees coupling angle, 15 mm blade height, and 85 mm blade length gives the highest signal to noise ratio. The shorter blade (85 mm) is suggested by both designs, but the two designs are different in the other three variables. Further analysis of the noise variables shows that lowering clay temperature significantly reduces cutting speed. Although there is more than one design that can resolve changes in clay thickness and clay orientation, a 15 mm blade height is the only design insensitive to the clay temperature change.     

Fluoroscopic MR of the pharynx in patients with obstructive sleep apnea

PURPOSE: The purpose of our study was to introduce an ultrafast MR imaging technique of the pharynx as a diagnostic tool for viewing the mechanism of obstruction in patients with obstructive sleep apnea. METHODS: Six healthy volunteers and 16 patients with obstructive sleep apnea were examined on a 1.5-T whole-body imager using a circular polarized head coil. Ultrafast two-dimensional fast low-angle shot sequences were obtained in midsagittal and axial projections during transnasal shallow respiration at rest, during simulation of snoring, and during performance of the Müller maneuver. All patients underwent physical examination, transnasal fiberoptic endoscopy, and polysomnography. RESULTS: Five to six images were obtained per second with an in-plane resolution of 2.67 x 1.8 mm and 2.68 x 2.34 mm, allowing visualization of motion of the tongue, soft palate, uvula, and posterior pharyngeal surface. MR findings correlated well with results of clinical examination. The length of obstruction in the oropharynx, which cannot be ascertained by transnasal endoscopy of the pharynx, was clearly visible MR images. Differences between patients with obstructive sleep apnea and healthy subjects in terms of the degree of obstruction in the velopharynx and oropharynx depicted on MR images during the Müller maneuver were highly significant. CONCLUSION: We believe that ultrafast MR imaging is a reliable noninvasive method for use in the evaluation of obstructive sleep apnea.     

Medical exercises by the National Guard for underserved Americans

The aims of this study were to analyze the characteristics of craniofacial structure in normal occlusion and to assess the relationship between the skeletal and occlusal pattern. Fifty-seven subjects with normal occlusion were divided into three skeletal groups according to Hauston measurement. One hundred and sixty-six subjects with Angle's malocclusion were also classified according to ANB values. The result showed that there were significant differences in the values of NA-APg, AB-NPg, SNA, SNB, U1-NA, L1-NB among the three groups. These data indicate that skeletal pattern does not coincide with occlusion. Different skeletal pattern exists even in normal occlusion. In diagnosis and treatment planning, the data of skeletal pattern should be referred.     

Bicarbon valve -- European multicenter clinical evaluation

The present study aimed to examine whether any pattern of associations could be found between the posture of the head and neck, and the occurrence of malocclusions. The sample comprised 96 children (45 M, 51 F) aged 7-13 years, sequentially admitted for orthodontic treatment of severe malocclusions. Malocclusions were diagnosed clinically and classified into occlusal, spacing, and dentitional anomalies and their subdivisions. Craniovertical, craniocervical, and cervicohorizontal postural variables were recorded from lateral cephalometric radiographs taken with the subject standing with the head in the natural head position (mirror position). A clear pattern of associations between crowding and craniocervical posture was found. Subjects with anterior crowding, i.e. more than 2 mm lack of space in the upper or lower anterior segments of the dental arch, had craniocervical angles that were on average 3-5 degrees larger than subjects without crowding (P < 0.05, P < 0.01). The findings were in agreement with the soft tissue stretching hypothesis, according to which the sagittal development of the dentoalveolar arches is impeded by the increased dorsally-directed soft tissue pressure in subjects with extended craniocervical posture.     

Juvenile chronic arthritis: a cephalometric analysis of the facial skeleton

A retrospective cross-sectional cephalometric investigation was undertaken to examine the facial form of a group of Finnish children with juvenile chronic arthritis (JCA). Following digitization, the radiographs were divided into three age groups, and according to whether or not 'bird-face' deformity was present. From a total of 67 cases (39 females and 28 males) 19 per cent were judged to be 'affected'. Analyses were carried out and the groups compared using t-tests. The mandible was found to be smaller both in ramal height and body length in the affected sample, with reduction in posterior face height being only partly compensated by increase in bony apposition at the angle producing antegonial notching. There was posterior rotation of the mandible with a reduction in angles S-N-B and S-N-Pog, and an increase in the gonial angle, the angle between the mandibular plane and S-N, maxillary, and occlusal planes. The changes in the maxilla were less marked. Although S-N-A was reduced in all three age groups, it was not significantly so. Maxillary length (ANS-PNS) was significantly smaller in the two younger age groups. In the vertical plane maxillary dimensions were reduced in the two younger age groups. A highly significant increase in the occlusal to maxillary planes angle was observed in all groups. There was, however, no difference in S-N to maxillary planes angle, indicating a more steeply inclined occlusal plane due to subnormally erupted maxillary molars. Although the inter-incisal angle was reduced there was no significant difference in the incisor inclinations in relation to the jaws and despite the posterior rotation of the mandible there was no significant increase in size of overjet or in the frequency of anterior open bite.     

Effect of gut transposition on the expression of the endocrine gene neurotensin

PURPOSE: The purpose of this study was to evaluate joint position sense (JPS) in patients with posttraumatic glenohumeral instability. MATERIALS AND METHODS: In 28 patients with posttraumatic instability and in a matched control group of 30 subjects proprioception capability was evaluated. For documentation of proprioception an angle reproduction test (ART) was performed with which joint positions sense (JPS) was measured for abduction, flexion, and rotation in three angles each. RESULTS: In both groups there was a significant better JPS with visual control than without. In contrast to the control group the patients were not able to increase angle reproduction capability without visual control when comparing positions below shoulder level with positions at or above shoulder level. When comparing the patients to the controls there were differences in most of the ARTs with worse results in the patient group. These differences were significant in 150 degrees flexion with and without visual control, in 150 degrees abduction without and in 100 degrees abduction with visual control. For rotation there were trends for almost all joint positions, however, the differences were significant only in the -45 position. When comparing the noninjured contralateral shoulder of the patients with the control group, there still were differences. Again these were not in all joint positions significant, but significant worse JPS could be demonstrated in 150 degrees abduction without visual control, 50 degrees flexion without visual control, -45 degrees rotation without and 0 degrees rotation with visual control. CONCLUSIONS: A proprioceptive deficit can be documented in patients with posttraumatic glenohumeral instability. This may be one reason for permanent instability. The contralateral joint also shows reduction in joint position sense. For consecutive treatment as well as for rehabilitation both shoulder joint should be addressed.     

RH真空精炼用顶枪枪头扩张角的浅析

RH真空室是RH真空精炼冶金反应的熔池,RH真空精炼脱碳反应的反应速度与RH真空精炼用顸枪枪头参数的设定有密切关系。借助商业软件GRAFTOOL3．0对R．H真空精炼用顶枪扩张角大小进行流场数值模拟,分析了不同扩张角角度下的射流状态,对R．H吹氧脱碳提供了重要科学依据,验证了最佳扩张角角度。     

Determination of the angle between the acceptor and anticodon stems of a truncated mitochondrial tRNA

Significant departures from the canonical (cloverleaf) secondary structure of transfer (t)RNAs can be found among the mitochondrial (m)tRNAs of higher metazoans; these mtRNAs thus pose a challenge to the concept of an invariant, L-shaped tertiary conformation for all tRNAs. For bovine mtRNASer(AGY), which lacks the entire "dihydrouridine" (dhU) arm, two distinct tertiary models have been proposed: the first model preserves the L-shaped conformation at the expense of overall size; the second model preserves the absolute distance between the 3' terminus and the anticodon loop, while allowing the acceptor-anticodon interstem angle to vary. We have tested the central predictions of these two models by performing a series of transient electric birefringence measurements on bovine mtRNASer(AGY) constructs in which the aminoacyl-acceptor and anticodon stems were each extended by approximately 70 bp. This mtRNA species is particularly amenable to analysis, since the native bovine (heart) mtRNA is completely unmodified outside of the anticodon loop. For magnesium ion concentrations above 1 mM, the interstem angle for the extended mtRNA, 120(+/-5) degrees, is approximately 50% larger than the corresponding angle for yeast tRNAPhe (70-80 degrees) under the same ionic conditions. Furthermore, the interstem angles of the two tRNAs exhibit strikingly different responses to the addition of magnesium ions: the interstem angle for yeast tRNAPhe is reduced by nearly 50 % upon addition of 2 mM magnesium ions, whereas the angle for mtRNASer(AGY) increases by about 10%. Our data thus support a central prediction of the second model; namely, that truncated mtRNAs will possess more open interstem angles. In addition, we demonstrate that birefringence amplitude data can be used to provide model-independent estimates for the interstem angles.     

Metatarsophalangeal and intermetatarsal angle: different values and interpretation of postoperative results dependent on the technique of measurement

For measurement of the first metatarsophalangeal angle and intermetatarsal angle I-II, five different methods for drawing the axis of the first metatarsal have been published. This study aimed to evaluate differences in the resulting angles that depend on the method of drawing this axis. Using pre- and postoperative radiographs of 20 patients who had surgery on the hallux (chevron procedure), highly significant differences were found: mean values for the preoperative metatarsophalangeal angle ranged from 27.3 degrees to 31.9 degrees; the mean postoperative values were calculated at 8.6 degrees to 20.3 degrees. The preoperative mean of intermetatarsal angle I-II showed values from 13.0 degrees to 17.6 degrees; the postoperative mean ranged from 5.2 degrees to 16.7 degrees. These differences--especially in the postoperative evaluation--resulted in a postoperative improvement between 11.6 degrees and 20.8 degrees for the metatarsophalangeal angle and between 0.9 degrees and 10.0 degrees for the intermetatarsal angle. These wide differences seem to be unacceptable for angles as a criterion of success in surgery on the hallux. The reason for these discrepancies can be found in the different relations of the points of reference to the anatomical outline of the metatarsal and the site of osteotomy. As a consequence of this study, defining the axis of the first metatarsal as a line connecting the center of the articular surface of the metatarsal head and the center of the proximal articulation can be recommended as the most appropriate method. The resulting angles are independent of the type of surgery performed on the hallux.     

An evaluation of the length-tension relationship in elderly human plantarflexor muscles

The purpose of this study was to determine the effect of aging on the muscle length-tension relationship in the plantarflexor muscles of 10 subjects aged 20-30 yr (Mean = 23; 5 males, 5 females), 10 subjects aged 60-80 yr (Mean = 72.3; 5 males, 5 females), and 10 subjects over 80 yr (Mean = 84.1, 5 males, 5 females). Isometric twitch properties, maximum voluntary strength, passive tension, and range of motion were measured at five different joint angles [20 degrees dorsiflexion (DF), 10 degrees DF, 0 degree, 10 degrees plantarflexion (PF), and 20 degrees PF]. Active (evoked and voluntary) and passive torque production were maximal when the ankle was rotated into the DF positions for all three age groups, whereas the lowest values were recorded when the ankle was rotated into 20 degrees PF. Males were stronger than females at all joint angles (p < .01). Also, young adults were stronger than both elderly adult groups (p < .01). These results illustrate that despite the considerable age-associated loss in both voluntary and evoked strength in the plantarflexors, the optimal angle for torque production remains the same for younger and older adults.     

Further studies into proximal interphalangeal joint dimensions for the design of a surface replacement prosthesis: medullary cavities and transverse plane shapes

The proximal and middle phalanges from 83 proximal interphalangeal joints (PIPJs) were set in clear plastic and sectioned in the transverse plane leaving the heads whole. The sections were cleaned, shadowgraphed and measured. The medullary canals were marked on sagittal and frontal plane shadowgraphs of the intact bones and analysed. The information was then used in the design of a surface replacement prosthesis for the PIPJs. The main dorsal surface of the proximal phalanx (PP) was found to be angled to the longitudinal baseline of the bone by a mean of 5.19 degrees. This angle increased just proximal to the phalangeal head to a mean of 11.84 degrees. The mean ratio between these angles was 2.71. The phalangeal shaft bone was thicker laterally than dorsally and palmarly, and thicker dorsally than palmarly for the proximal and middle phalanges throughout the length of the bone. The shape and size of the transverse cross-section of the medullary canal changed throughout the length of the shaft. The centreline of the PP medullary canal coincided with the midline of the bone in the frontal plane and was approximately a straight line along the length of the canal. In the sagittal plane the centreline was slightly palmar to the midline and the angle between it and the longitudinal baseline of the bone changed along the length of the canal. In the region of the shaft just proximal to the PP head (where the stem of a surface replacement prosthesis would fit) the mean angle was 10.63 degrees. The centreline was offset dorsally from the centre of rotation of the PIPJ by a mean of 0.83 mm, 0.83 mm, 0.80 mm and 0.57 mm for the index, middle, ring and little fingers respectively, with an overall mean of 0.76 mm. The mean PP head heights (transverse plane) were 9.17 mm, 9.33 mm, 8.73 mm and 7.40 mm and the mean PP widths (transverse plane) were 12.86 mm, 13.25 mm, 12.75 mm and 10.54 mm for the index, middle, ring and little fingers respectively. The mean angle between the lateral sides of the condyles to the transverse baseline was 78.35 degrees and the mean distance from the centreline of the PP head (transverse plane) to the bases of the two condyles was 4.69 mm. The mean maximum depth of the PP head intercondylar sulcus in the frontal plane was 0.72 mm and in the transverse plane, the mean maximum depth of the intercondylar sulcus on the anterior face was 0.82 mm.     

X型正断层交汇处应力分布及其油气地质意义

为了查明X型正断层夹角变化对应力分布特征及油气运聚的影响,应用FLAC3D软件建立了X型正断层夹角自15(°)至90(°)变化的6种模型,并对其交汇处应力场分布特征进行了三维数值模拟分析。结果表明:断裂交汇部位垂直应力表现为挤压性质的力,不明显受相交角度变化的影响,而水平应力主要为拉张性质的力,当θ大于45(°)后出现挤压应力;断裂交汇部位水平、垂直应力集中程度具有先增大后减小的变化规律,垂直应力大小较水平应力明显大一个数量级,当相交角度为45(°)时,水平、垂直应力集中程度达到最大。应力高集中区能够释放大量应变能,有利于油气的运移和聚集,因此,交角为45(°)的X型正断层是油气富集的有利区。     

Quantitative analysis of human walking trajectory on a circular path in darkness

Thirteen normal (eight young and five older) subjects and a patient who was removed left sided acoustic neurinoma were tested to walk blindfolded along circular paths. They were asked to walk completing two revolutions and to stop when they judged they had returned to the initial position with their head faced to the initial directions. Movements of two markers on the subjects head were recorded by three dimensional motion analyzing system (ELITE system) at 50 Hz which allowed us to measure (a) total walked distance, (b) average radius of the trajectory, and (c) cumulative angle of rotation. Eight young subjects were tested on three circles with radii 0.5, 0.9, and 1.15 m, in two conditions (control, and with mental arythmetic), only to clockwise direction. Five older subjects and a patient were tested on a circle of 0.9 m radius in two conditions, but to both directions, counterclockwise and clockwise. Walked trajectories of young subjects were smooth, whereas those of older subjects tended to be polygonal. Young subjects overshot the ideal distance (6.6%) and ideal radius (9.5%), whereas they undershot the ideal angle (5.1%). There was no effect of circle size or condition on these variables. On the other hand, there was a significant effect of condition on average radius in the older group. The performance of older subjects seemed to be affected by the concurrent mental task. Comparing the counterclockwise walk, the older subjects undershot the turning angle much more than the young subjects which suggest deficits in the vestibular function with aging. The patient showed larger radius and smaller angle while she turned to the healthy side (clockwise) than to the affected side (counterclockwise). Lack of unilateral vestibular information seemed to have affected the circular walking trajectory.