Use of digital photographs for artificial tooth selection

Digital photography has become available to everybody. The aim of this study was to examine possibility of calculating the width of a missing central incisor using digital photographs. Digital photographs were obtained from 51 dentate subjects using a 3.1 Megapixel digital camera from various distances: 35 cm, 70 cm, 1 m and 1.5 m. For the calculation of the width of maxillary left central incisor (MLI), the following equation was used: MLI(calculated) = Photographic width of MLI x IPD / photographic IPD. Statistical analysis was made (Kolmogorov-Smirnov test, dependent sample t-test, correlation and frequencies) using SPSS 10.0 for Windows. Results revealed no significant difference between the calculated MLI (70 cm, 1 m and 1.5 m distance) and actual MLI, however calculated MLI from 35 cm distance was significantly different from the actual MLI value (p < 0.01). The highest correlation was between calculated MLI (70 cm distance) and actual MLI. However, the highest percentage of results from a distance of 70 cm also fitted within +/- 0.3 mm; +/- 0.5 mm and +/- 1 mm difference from the actual MLI values. However, the results obtained from 1 m distance were also satisfactory. The technique of use of digital photography is of proven value in calculating the width of a maxillary central incisor. The photographs using a simple digital camera should be taken from a distance from 70 cm to 1 m. Saving such photographs in a dental office may eventually be helpful for calculating dimensions of artificial teeth.     

A Small-Scale Comparison of Iceland Scallop Size Distributions Obtained from a Camera Based Autonomous Underwater Vehicle and Dredge Survey

An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was and deg that resulted in error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately cm was seen, which could be attributed to pixel error, where each pixel represented cm. After correcting for this difference the estimated heights ranged from cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.     

Recognition of spatial parameters by echolocation in the vampire bat,Desmodus rotundus

Summary Three vampire bats (Desmodus rotundus) were trained in a two-choice apparatus (Fig. 1) to select the one of two passages that contained a vertical stick or narrow metal strip at a distance of 45 cm. To single sticks in isolation they responded at a width of 1.1 mm or more. Large surfaces in the vicinity of the target impaired the locating ability; the animals correctly choose a 20-mm-wide strip 2.5 cm in front of a strongly reflecting plate (Fig. 2) or 6 cm away on one side of it (Fig. 3).In a flight tunnel the response to single vertical obstacles of various size was studied. The sudden increase in echolocation-sound repetition rate as the obstacle was approached marked the response distance. This distance was 50–80 cm for thread obstacles 0.5 mm thick; the threshold diameter was 0.23 mm (Fig. 6). When the obstacles were mounted in a 30-cm-wide constriction of the tunnel the response occurred later; even a 10-mm-wide strip did not elicit a change in the sound pattern until the bats had approached to a distance of 60 cm (Fig. 6). The response distance increased significantly when the obstacles were moved in front of or beyond the constriction (Fig. 8).     

Lip-nasal aesthetics following Le Fort I osteotomy

Forty-one patients undergoing Le Fort I osteotomy for superior and/or anterior repositioning of the maxilla were prospectively studied for changes in soft-tissue morphology of the nasomaxillary region. Nasal parameters studied were changes in interalar rim width and nasal tip projection. It was observed that alar rim width increases with anterior and/or superior repositioning of the maxilla, but increases in nasal tip projection occur only when there is an anterior vector of maxillary movement. These nasal changes could not be quantitatively correlated to magnitude of maxillary movement. Lip changes studied were the horizontal displacement at the vermilion border and subnasale versus that of the incisal edge and point A, respectively, when the maxilla is sagittally advanced and the vertical shortening of the lip versus that of the incisal edge when the maxilla is shortened. Using linear regression analysis, horizontal displacement of the upper lip at the vermilion border was 0.82 +/- 0.13 mm for every 1 mm of maxillary advancement at the incisal edge (p less than 0.001) and 0.51 +/- 0.13 at the subnasale for every 1 mm of maxillary advancement at point A (p less than 0.001). Eighty percent of patients undergoing maxillary intrusive procedures had lip shortening ranging from 20 to 50 percent of the vertical maxillary reduction. Surprisingly, no statistically significant correlation could be demonstrated for lip shortening versus extent of vertical maxillary reduction. Previous literature in disagreement with these findings is discussed. Guidelines for treatment planning utilizing these data are suggested.     

Evaluation of the distortion of photographs using various focal lengths

It is of interest to evaluate the distortion of intraoral frontal photographs using various focal lengths. Intra-oral frontal view pictures of 20 subjects were taken using a standard 18-55mm lens of a DSLR camera at three different focal lengths (18mm, 35mm, 55mm). 52 experienced orthodontists were chosen and they were asked to assess the photographs and choose the one with the least amount of distortion. Majority of the orthodontists selected the frontal photograph taken at a focal length of 35mm as the best photo with the least distortion among the three photographs. The photos taken at a focal length of 35 mm showed the least amount of distortion.     

The relationship between kinematic determinants of jump and sprint performance in division I women soccer players

The purpose of this study was to determine the relationship between measures of unilateral and bilateral jumping performance and 10- and 25-m sprint performance. Fifteen division I women soccer players (height 165 ± 2.44 cm, mass 61.65 ± 7.7 kg, age 20.19 ± 0.91 years) volunteered to participate in this study. The subjects completed a 10- and 25-m sprint test. The following jump kinematic variables were measured using accelerometry: sprint time, step length, step frequency, jump height and distance, contact time, concentric contact time, and flight time (Inform Sport Training Systems, Victoria, BC, Canada). The following jumps were completed in random order: bilateral countermovement vertical jump, bilateral countermovement horizontal jump, bilateral 40-cm drop vertical jump, bilateral 40-cm drop horizontal jump, unilateral countermovement vertical jump (UCV), unilateral countermovement horizontal jump, unilateral 20-cm drop vertical jump (UDV), and unilateral 20-cm drop horizontal jump (UDH). The trial with the best jump height or distance, reactive strength (jump height or distance/total contact time), and flight time to concentric contact time ratio (FT/CCT) was recorded to analyze the relationship between jump kinematics and sprint performance. None of the bilateral jump kinematics significantly correlated with 10- and 25-m sprint time, step length, or step frequency. Right-leg jump height (r = -0.71, p = 0.006, SEE = 0.152 seconds), FT/CCT (r = -0.58, p = 0.04, SEE = 0.176 seconds), and combined right and left-leg jump height (r = -0.61) were significantly correlated with the 25-m sprint time during the UCV. Right-leg FT/CCT was also significantly related to 25-m step length (r = 0.68, p = 0.03, SEE = 0.06 m) during the UDV. The combined right and left leg jump distance to standing height ratio during the UDH significantly correlated (r = -0.58) with 10-m sprint time. In comparison to bilateral jumps, unilateral jumps produced a stronger relationship with sprint performance.     

A morphometric study of the external ear: age- and sex-related differences

The human ear is a defining feature of the face. Its subtle structures convey signs of age and sex that are unmistakable yet not easily defined. With analysis of normative cross-sectional data, this study explored anatomic and aesthetic differences in the ear between men and women, as well as changes in ear morphology with age. A total of 123 volunteers were randomly selected for this study. The cohort consisted of 89 women ages 19 to 65 years (median age, 42 years) and 34 men ages 18 to 61 years (median age, 35 years). The average total ear height across the entire cohort for both left and right ears was 6.30 cm, average lobular height was 1.88 cm, and average lobular width was 1.96 cm. As expected based on head size, significant sex-related differences were noted in the distance from the lateral palpebral commissure to both the helical root and insertion of the lobule. Measured distances in both vectors were approximately 4.6 percent longer in men than in women. Similarly, the height of the pinna was significantly larger in men than in women by approximately 6.5 percent. The average height and width of the lobule, however, were nearly identical in men and women. Analysis of age-related data showed a significant difference in the total ear height between the subpopulations; however, this difference was not significant after the lobular height was subtracted from total ear height, suggesting that the lobule was the only ear structure that changed significantly with age. In addition, lobular width decreased significantly with age. This study establishes normative data for ear morphology and clearly demonstrates the changes in earlobe morphology that occur with advancing age.     

Hybrid performance and genetic distance as revealed by the (GATA)4 microsatellite and RAPD markers in pearl millet

 Genetic diversity in five cytoplasmic male-sterile and seven restorer lines of pearl millet was determined by DNA fingerprinting using a (GATA)₄ microsatellite and randomly amplified polymorphic DNAs (RAPDs). A total of 160 polymorphic loci were generated and, based on the polymorphism data, similarity index values ranged from 0.81 to 0.50. Cluster analysis was performed and relationships among these lines revealed that they were not in agreement with the available pedigree data. The per se performance of parents and hybrids was analyzed for days-to-50% flowering, plant height, productive tillers, ear length, ear width, 1000-grain weight and grain yield per plot. Path co-efficient analysis revealed that productive tillers, ear width and days-to-50% flowering had a relatively large positive effect. The correlation values were mostly not significant with respect to genetic distance, except for days-to-50% flowering, ear length and ear width. Our results have indicated that genetic-distance measures based on the (GATA)₄ microsatellite and RAPDs may be useful for the grouping of parents, but not for predicting heterotic combinations, in pearl millet. Received: 3 January 1998 / Accepted: 25 February 1998     

Vertical and Horizontal Vegetation Structure across Natural and Modified Habitat Types at Mount Kilimanjaro

In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866–4550m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.     

Relationship between reactive strength variables in horizontal and vertical drop jumps

The aim of this study was to investigate the relationship between reactive strength in a vertical and a horizontal drop jump (DJ). Subjects (n = 28) with previous jump training experience, performed 6 vertical DJs and 6 horizontal DJs from a 0.4-m box. Contact time, height jumped, distance jumped, and reactive strength index (RSI) were calculated and analyzed. Typical error measurements (TEMCV%) and intraclass correlations (ICCs) were used to assess the intrasubject reliability. Relationships between jumps and within jumps of the aforementioned variables were assessed using ICCs. The ICC (r > 0.789) and the TEMCV% (<10%) indicated good reliability for both vertical and horizontal DJs across each variable. Contact time showed no relationship between jumps (r = 0.222) and had no effect on the vertical DJ height (r = 0.152) or horizontal DJ distance (r = 0.261). The RSI correlation (r = 0.533) indicated a large relationship between reactive ability in the horizontal DJ and the vertical DJ. Contact times were significantly lower in vertical DJs compared with horizontal DJs (p < 0.0001). This study indicated that horizontal DJs are reliable and may be better used to train reactive movements that do not require brief contact times.     

A television/computer three-dimensional surface shape measurement system

An optical scanner is described which has been designed primarily for the measurement of human back shape. A projector and television camera were mounted together in a box which could rotate about a horizontal axis. The projector shone a horizontal plane of light, which was viewed at an angle from below by the television camera, linked directly to a minicomputer. The shape of the line of light formed by the plane as it fell on an object, together with a knowledge of the geometry of the system, enabled three-dimensional coordinates of points on the line to be calculated. A record of a surface shape was built up by scanning the object in about 2 s. Calibration of the system was achieved by scanning an object of known dimensions. Sets of algorithms are described which derive geometric parameters from the calibration scan and which sort surface shape coordinates, outline them and detect special markers from the surface shape scan. The accuracy of measurement exceeded the design aim of +/- 3 mm in each axis within a volume of 400 mm x 500 mm x 300 mm.     

游离龈移植术后龈瓣收缩效果的临床研究

目的:评估游离龈移植术后3月内龈瓣在垂直向、水平向宽度改变并计算其表面积的收缩情况。方法:选取23例Miller Ⅲ类牙龈退缩患者,因下颌前牙区颊侧角化龈宽度不足(2 mm)行游离龈移植术。分别比较基线、术后1和3月游离龈瓣水平向及垂直向宽度的改变并计算龈瓣表面积的收缩情况。结果:经游离龈移植术的23例患者术区游离龈全部成活,牙龈无红肿,附着龈宽度可达3-5 mm。基线处、术后1月、3月水平向龈瓣宽度分别为9.83±1.7、8.97±1.5、8.48±1.65 mm;基线水平、术后1月、3月垂直向龈瓣宽度分别为4.02±0.61、3.61±0.67、3.24±0.67 mm。与基线时比较,术后1月、3月水平向、垂直向龈瓣宽度、龈瓣表面积均明显降低,差异均具有显著差异(P0.05)。结论:游离龈移植术可增加牙龈退缩患者的附着龈宽度,术后龈瓣存在水平向和垂直向收缩,且垂直向更明显。此外,龈瓣收缩存在个体差异。     

No evidence for mesothelial cell contact across the costal pleural space of sheep

Pleural space width was measured by four morphological approaches using either frozen hydrated or freeze-substituted blocks of chest wall and lung. Anesthetized sheep were held in the lateral (n = 2), sternal recumbent (n = 2), or vertical (head-up; n = 2) position for 30 min. The ribs and intercostal muscles were excised along a 20-cm vertical distance of the chest wall region, which was sprayed with liquid Freon 22, cooled with liquid nitrogen, to facilitate the fastest possible freezing of the visceral and parietal pleura. We measured pleural space width in frozen hydrated blocks by reflected-light and low-temperature scanning electron microscopy and in freeze-substituted, fixed, and embedded tissue blocks by light and transmission electron microscopy. We combined the data from the two groups of sheep held sternally recumbent and vertical because the results were comparable. The average arithmetic mean data for pleural space width determined by reflected-light analysis for samples near the top (18.5 microns) and bottom (20.3 microns) of the chest, separated by 15 cm of lung height, varied inversely with lung height (n = 4; P less than 0.009). The average harmonic mean data demonstrated a similar gravity-dependent gradient (17.3 and 18.8 microns, respectively; P less than 0.02). Therefore a slight vertical gradient of approximately -0.10 micron/cm of lung height was found for costal pleural space width. Pleural space width in the most dependent recesses, such as the costodiaphragmatic recess, reached 1-2 mm. We never found any contacts between the visceral and parietal pleura with either of the frozen hydrated preparations. No points of mesothelial cell contact were revealed in the light- and transmission electron microscopic views of the freeze-substituted tissue, despite an apparent narrower pleural space associated with the tissue-processing steps. We conclude that the pleural space has a slightly nonuniform width, contacts if they occur must be very infrequent, and pleural liquid clearance is probably facilitated by liquid accumulation in dependent regions where lymphatic pathways exist.     

Up,up, and away: relative importance of horizontal and vertical escape from predators for survival and senescence

Animals fleeing a potential predator can escape horizontally or vertically, although vertical flight is more expensive than horizontal flight. The ability to escape in three dimensions by flying animals has been hypothesized to result in greater survival and eventually slower senescence than in animals only fleeing in two dimensions. In a comparative study of flight initiation distance in 69 species of birds when approached by a human, I found that the amount of variance explained by flight initiation distance was more than four times as large for the horizontal than the vertical component of perch height when taking flight. The slope of the relationship between horizontal distance and flight initiation distance (horizontal slope) increased with increasing body mass across species, whereas the slope of the relationship between vertical distance and flight initiation distance (vertical slope) decreased with increasing body mass. Therefore, there was a negative relationship between horizontal and vertical slope, although this negative relationship was significantly less steep than expected for a perfect trade‐off. The horizontal slope decreased with increasing density of the habitat from grassland over shrub to forest, whereas that was not the case for the vertical slope. Adult survival rate increased and rate of senescence (longevity adjusted for survival rate, body mass and sampling effort) decreased with increasing vertical, but not with horizontal slope, consistent with the prediction that vertical escape indeed provides a means of reducing the impact of predation.     

New modification in otoplasty: anterior approach

After harvesting the conchal cartilage in a large series of secondary rhinoplasties using the anterior approach, there was a marked improvement in the shape of the auricle, with unnoticeable scarring hidden under the convolution of the antihelix. In this series of 250 cases, there were no hypertrophic scars or keloid formations. Based on these favorable results, a new modification of otoplasty was developed using only the anterior approach. Between 1992 and 2000, 108 otoplasties were performed on 55 patients to correct the prominent ear using only the anterior approach. All maneuvers used in modern otoplasty, such as conchal reduction, scaphal cartilage scoring and folding, placement of horizontal mattress buried sutures, conchal setback, and the positioning of the tail and upper pole, can be easily and effectively performed using only the anterior approach as described in this article. The use of an anterior approach does not disturb the neurovascular system of the ear because it is located on the ear's posterior side. Overall, patient and physician satisfaction has continued to be very high during the 8 years that this technique has been used. Some patients experienced a few minor complications, such as postoperative pain (16.3 percent), late suture reaction (1.8 percent), hidden helix (3.6 percent), and partial relapse (3.6 percent), that were easily corrected by the application of a Kaye-type buried suture and that were not directly related to the technique.     

The tumbling concha-cartilage flap for correction of lop ear

This article presents a new surgical method that uses tumbling concha-cartilage flaps to correct lop ears. Through a posterior or anterior auricular skin incision, a rectangular or T-shaped cartilage flap is elevated from the concha and tumbled backward. After passing under the postauricular skin, the flap's tip is fixed to the lidded helix or scapha. The recoiling force of the flap's conchal side enables the lidded portion to be in a normal, erect, anatomic position. The method also increases the vertical height of the ear and creates a normally shaped scapha. Sixteen lop ears were corrected using this procedure, with most of them maintaining natural auricular features. Therefore, this method was considered effective for the correction of moderate lop ear deformity.     

Predictive performance of random forest on the identification of mangrove species in arid environments

Machine learning methods are the most popular approaches for carrying out classification in remote sensing studies. Of the methods available, random forest (RF) is the one most often used due to its high predictive performance. The objective of this study was to assess the predictive performance of RF in identifying (classifying) mangrove species in an arid environment using two cameras: one conventional (visible part of the light, RGB), the other specialized (Green, Red, Near-infrared, GRN). The RGB and GRN bands were used with derived vegetation indexes (for each camera), the canopy height model (derived from photogrammetry), and distance to water (derived from raster analysis) to classify the study area in eight classes (including three mangrove species) using RF. Results suggest only slight differences in predictive performance (validation) between the products derived from the GRN and RGB cameras, the accuracy values ranged from 0.58 to 0.77 and from 0.53 to 0.72 for RGB and GRN, respectively. The most important variables were the distance to water and canopy height model for both cameras, followed by specific bands and vegetation indices. The study concludes that conventional cameras mounted in commercial drones can be used efficiently to identify mangrove species in arid environments when the classification model uses physical variables of the species (tree height) and the system (distance to water). Results of this study can be applied to describe spatial distributions by species in small or large patches of mangroves in arid environments, thus improving our ecological knowledge of this ecosystem.     

Change in take‐off elevation angle after limb autotomy mitigates the reduction in jumping distance in rice grasshoppers Oxya yezoensis

Autotomy is the ability to spontaneously self‐amputate a limb or other appendage, often as a reflexive action. This limb amputation typically occurs as a specialized defensive response to an attack from a predator and thereby enables the prey to escape from predation. Despite the benefits of escape, autotomized organisms lose the body part and its associated function. Here, we investigated the jumping behavior and performance of one‐leg‐autotomized and intact rice grasshoppers, Oxya yezoensis, to examine changes in jumping behavior after autotomy. The take‐off elevation of autotomized grasshoppers was 7.8° lower than in intact grasshoppers, resulting in nearly a 45° angle of take‐off, which maximized the jumping distance. Kinematic analyses of the jumping manner revealed that the angle of the femur during jumping differed between intact and autotomized grasshoppers, suggesting that the grasshoppers behaviorally change the take‐off elevation after autotomy. According to analyses of jumping performance, the degree of decline in performance differed between horizontal distance and vertical height. Even though they jumped on only one hind leg, one‐leg‐autotomized grasshoppers realized 69% performance along a horizontal distance relative to intact grasshoppers. In contrast, autotomized grasshoppers realized only a 44% performance in vertical height compared to intact grasshoppers. The difference in take‐off elevation between autotomized and intact grasshoppers is likely related to the observed difference in the magnitude of the decline in performance between horizontal distance and vertical height. These results suggest that rice grasshoppers may alter their take‐off elevation after limb autotomy to minimize the reduction in jumping distance.     

Cephalometric indicators of the vertical dimension of occlusion

The aim of this investigation was to establish precise indicators of the vertical dimension of occlusion (VDO) which could be used as objective parameters in prosthodontic treatment providing exact control of the reconstructed vertical dimension of occlusion, early detection of errors and correction of the vertical dimension of occlusion during complete denture manufacturing. A total of 60 lateral cephalometric radiographs of subjects with natural dentition and class I skeletal jaw relationship, of Serbian nationality from the region of Vojvodina, were included in the investigation. Thirty subjects were males, and thirty females, their age range was 20 to 29 years. Cephalometric analysis was performed by using "Dr. Ceph" computer software (FYI Technologies, GA, USA). By evaluation of the craniofacial complex in subjects with natural dentition, horizontal dentofacial developmental growth was established in the examined sample and it was based on the relationship between the posterior and anterior total facial height (S-Go:N-Me, female X=68.96%, male X=72.8%) and statistically significant differences were found between the sexes in almost all linear dimensions and in the relation between the posterior and the anterior total facial height. Highly significant differences (p<0.001) between the sexes were found in regard to anterior total facial height (N-Me, male X=120.75 mm, female X=112.72 mm) and the anterior lower facial height (ANS-Me, male X=67.87 mm, female X=61.50 mm) (p<0.05). The proportions of the upper and lower anterior facial heights (N-ANS:ANS-Me, male X=79.36%, female X=80.63%) were within normal values in both sexes. Facial harmony existed both in men and women. Cephalometric study of the subjects with complete natural dentition included in this study provided important and specific parameters for optimal reconstruction of vertical dimension of occlusion in the treatment of edentulous patients.