Craniofacial growth in patients with craniosynostosis

With the growing appreciation that traditional cephalographic analyses provide data of dubious scientific validity, this study was undertaken to investigate craniofacial growth using the technique of biorthogonal analysis. This specific technique for the analysis of shape change showed relatively minor contrasts between control and craniosynostotic patients between 6 and 10 years of age. By contrast, marked variation was noted within component regions of the craniofacial skeletons in both patient samples: a feature not evident from traditional cephalographic analyses.     

Bipedicle strap flaps in reconstruction of longitudinal dorsal skin defects of the digits

Dorsal skin defects in which the loss of integument is longitudinal in shape are not uncommon after injury by rotating machinery and by glass shearing along the length of the digit. This shape of defect is difficult to reconstruct with commonly used flaps but lends itself to reconstruction by the use of longitudinal bipedicle strap flaps moved across the dorsum of the finger from lateral to medial. A variant of this traditional technique was used in the reconstruction of 28 dorsal digital defects. The incidence of these defects and the need for this reconstructive technique were analyzed by a review of 1077 patients with dorsal digital injuries treated in a 6-year period between 1989 and 1995. Approximately 20 percent of all dorsal digital injuries requiring flap reconstruction were suitable for reconstruction with bipedicle strap flaps.     

Design of a Cryogenic Videocamera-Recorder and Image Processing System and Calculation of Volumes of Red Cells

Since Rowe reported that the storage technique for red cells at very low temperatures had been realized successfully (4, 5), many experts who work in the fields of cryobiology and medicine have turned their attention to this storage technique for tissues and organs (3). Since the first quantitative cryomicroscope was made successfully about 20 years ago (1), it has been possible to observe changes in shape and phase. Particularly the image processing technique has laid the foundation for quantitative analysis of the relationship between changes in shape and damage from freezing of cells and cooling rate and storage temperature. In this work, we constructed a system consisting of a cryomicroscope, a videocamera-recorder, and an image processor. We carried out many experiments with red cells in cold storage and have established a model for calculating the volumes of red cells. In our experiments we also dynamically traced the shape changes of cells with various experimental parameters.     

Shape changes and growth trajectories in the early stages of three species of the genus Diplodus (Perciformes, Sparidae)

The larvae of three species of the genus Diplodus (Diplodus vulgaris, D. sargus, and D. puntazzo) colonize shallow waters along the Mediterranean coasts and, after a short period spent in the water column, they settle. For all three species this habitat transition is characterized by important shape changes mostly related to swimming capacity and feeding behavior. In this study, geometric morphometrics are used to characterize shape changes during the early juvenile life of specimens collected in a single locality in order to compare growth curves and allometric relationships. Size-related shape changes proved to be similar for all three species and are consistent with the ecological transition. A nonparametric smoothing technique (Loess) was used to fit the scatter of shape on size. The graphical representation (of most size-related shape variability) of this fitting technique shows how major shape changes are rapid for small sizes and slow down successively. The approach allows for the visualization of allometry and the fitting technique might help in defining the allometric growth pattern, thus contributing to the study of the autoecology of the species and in establishing terms for comparison with other ecologically or phylogenetically related species.     

Investigation into the usability of geometric morphometric analysis in assessment of sexual dimorphism

Understanding sexual dimorphism is very important in studies of human evolution and skeletal biology. Sexual dimorphic characteristics can be studied morphologically and metrically, although morphologic studies pose several problems such as difficulties with quantification and interobserver error. Geometric morphometrics is a relatively new method that allows better assessment of morphologic characteristics. This paper aims to investigate the usability of this method by assessing three different morphologic characteristics in a sample of South African blacks: shape of the greater sciatic notch, mandibular ramus flexure, and shape of the orbits. Relative warps, thin-plate splines, and canonical variates analysis (CVA) analyses were performed. As expected, the shape of the greater sciatic notch provided the best separation between the sexes. Surprisingly, however, the shape of the orbits performed better that ramus flexure. Several possible explanations for this result are possible, which include the possibility that orbit shape is more sexually dimorphic than previously expected, or that biological reality is not reflected by this technique. More research is, however, needed.     

Body shape in relation to socio-economic status in young adults from the basque Country

Body shape has a great variability determined, partly, by energy intake and physical activity, as well as by gender and age. The aim of this research was to analyse the relation between socio-economic status (SES) and body shape estimated through the somatotype, in a sample of university students. The sample included 316 males and 635 females aged 18-33. Somatotype was estimated by the Heath-Carter anthropometric technique. The information included data of SES. A MANOVA test was used to test differences among groups. The mean somatotypes were 4.0-4.4-2.3 in males and 5.4 -3.4-2.2 in females. Sexual dimorphism for the whole somatotype was found (p < 0.001). There is a greater stability of the body shape in females regarding SES and more variability in males. Males' somatotype was significantly related to SES, low socioeconomic levels were associated with high values of endomorphy and mesomorphy.     

Multiple evidence for the role of an Ovate-like gene in determining fruit shape in pepper

Background  

Grafting is a widely used technique contributing to sustainable and ecological production of many vegetables, but important fruit quality characters such as taste, aroma, texture and shape are known for years to be affected by grafting in important vegetables species including pepper. From all the characters affected, fruit shape is the most easily observed and measured. From research in tomato, fruit shape is known to be controlled by many QTLs but only few of them have larger effect on fruit shape variance. In this study we used pepper cultivars with different fruit shape to study the role of a pepper Ovate-like gene, CaOvate, which encodes a negative regulator protein that brings significant changes in tomato fruit shape.     

A preliminary study of mandibular shape

There is a growing realization that traditional osteometric data are of uncertain scientific validity, primarily due to the lack of dissociation between size and shape parameters. This study was specifically based on the metrical definition of mandibular morphologic shape, using a technique termed medial axis transformation. It was based on the digitized mandibular outlines of three age-sexed samples of microcephalics, macrocephalics, and normocephalics. Evaluation of the derived medial axis lengths and branch point distances indicated complex patterns of mandibular shape contrasts between microcephalics and macrocephalics on the one hand and normocephalics on the other. Although larger more homogeneous samples are required to evaluate the specific factors influencing mandibular shape, the present data suggest an association between mandibular shape and cranial form.     

On comparing biological shapes: detection of influential landmarks.

For problems of classification and comparison in biological research, the primary focus is on the similarity of forms. A biological form consists of size and shape. Several approaches for comparing biological forms using landmark data are available. If the two biological forms are demonstrated to be different, the next important issue is to localize the differences by identifying those areas which differ most between the two objects. In this paper we suggest a technique to detect influential landmarks, those which contribute most to the difference between forms. We study the effectiveness of the technique using three-dimensional simulated data sets and two examples. Results suggest that the technique is useful in the study of biological form and its variation.     

生物4D打印技术在心血管组织工程中的研究及应用进展

3D生物打印技术是应用包含生物材料与活细胞在内的生物墨水来构造生物医学产品的技术，近年来得到快速发展。3D打印的组织是静态的，而人体的组织则处于实时动态之中，并且随时能够发生形态及性能的变化，要提高体外环境与体内真实环境的吻合度，就需要一种能够模拟这种动态过程的体外组织构建技术。4D打印概念的提出，给实现这种复杂技术提供了一条新的思路。4D打印可理解为“3D打印+时间”，在3D打印基础上，4D打印应用一种或多种对刺激具有响应的智能材料，这种材料可以在相应的刺激下改变它们的形态、性能及功能，以满足多种需求。本文重点关注4D打印技术在心血管系统中的最新研究进展及其潜在应用领域，为该项技术的发展提供一些理论及应用参考价值。     

Development of an in situ procedure to evaluate the reticulo-rumen morphology of sheep selected for divergent methane emissions

Published studies have shown that methane yield (g CH₄/kg dry matter) from sheep is positively correlated with the size (volume and surface area) of the reticulo-rumen (RR) and the weight of its contents. However, the relationship between CH₄ yield and RR shape has not been investigated. In this work, shape analysis has been performed on a data set of computerised tomography (CT) scans of the RR from sheep having high and low CH₄ yields (n=20 and n=17, respectively). The three-dimensional geometries of the RRs were reconstructed from segmented scan data and split into three anatomical regions. An iterative fitting technique combining radial basis functions and principal component (PC) fitting was used to create a set of consistent landmarks which were then used as variables in a PC analysis to identify shape variation within the data. Significant size differences were detected for regions corresponding to the dorsal and ventral compartments between sheep with high and low CH₄ yields. When the analysis was repeated after scaling the geometries to remove the effect of size, there was no significant shape variation correlating with CH₄ yield. The results have demonstrated the feasibility of CT-based computational shape determination for studying the morphological characteristics of the RR and indicate that size, but not shape correlates with CH₄ yield in sheep.     

A new method to study shape recovery of red blood cells using multiple optical trapping.

In this new method for studying the shape recovery of deformed red blood cells, three optical traps ("optical tweezers") induce a parachute-shaped red cell deformation, which is comparable to the deformation in small capillaries. The shape recovery is recorded, and a relaxation time is obtained for each individual red blood cell. The sensitivity of this technique for the detection of differences in relaxation times is demonstrated on subpopulations of density-separated red blood cells: "young" cells have shorter (162 ms) and "old" cells have longer (353 ms) relaxation times compared with the total population (271 ms). The relaxation time is remarkably shorter (114 ms) when the plasma surrounding the cells is replaced by a phosphate-buffered saline solution. The main advantages of this technique are the relatively short measuring and preparation time and the physiological type of deformation and shape recovery in which all relevant cell properties play a role. Therefore, especially when automated further, the technique may be a powerful tool for the study of (sub)populations of pathological red blood cells.     

Measuring egg size using digital photography: testing Hoyt's method using Florida Scrub-Jay eggs

ABSTRACT.   Egg volumes are most often estimated using a mathematical model that incorporates length and width measurements and a species-specific shape variable. Although adequate in many respects, this technique does not account for intraspecific variation in egg shape. We developed a computer-automated technique that uses calibrated digital photographs to render precise measurements of several egg-size parameters including length, width, volume, and surface area. The system extracts egg outlines from photographs, and divides each egg into latitudinal slices that are subsequently regarded as simple geometric shapes (cylinders or cone frustra) with volumes and surface areas that can be summed to generate size parameters for the entire egg. We tested this technique using 491 eggs from Florida Scrub-Jay ( Aphelocoma coerulescens ) nests and compared the resulting egg volumes with volumes calculated using the preeminent method of estimating volume from linear measurements. Our method was highly accurate, and differences between the volumes from our method and the alternative method were strongly associated with variation in egg shape. Advantages of our technique include decreased handling of eggs and increased accuracy. Software resources and additional information regarding the technique are available at http://www.archbold-station.org/abs/data/birddata/Bridge-JFO-eggsize.htm .     

Fabrication of Polymeric Coatings with Controlled Microtopographies Using an Electrospraying Technique

Surface topography of medical implants provides an important biophysical cue on guiding cellular functions at the cell-implant interface. However, few techniques are available to produce polymeric coatings with controlled microtopographies onto surgical implants, especially onto implant devices of small dimension and with complex structures such as drug-eluting stents. Therefore, the main objective of this study was to develop a new strategy to fabricate polymeric coatings using an electrospraying technique based on the uniqueness of this technique in that it can be used to produce a mist of charged droplets with a precise control of their shape and dimension. We hypothesized that this technique would allow facile manipulation of coating morphology by controlling the shape and dimension of electrosprayed droplets. More specifically, we employed the electrospraying technique to coat a layer of biodegradable polyurethane with tailored microtopographies onto commercial coronary stents. The topography of such stent coatings was modulated by controlling the ratio of round to stretched droplets or the ratio of round to crumped droplets under high electric field before deposition. The shape of electrosprayed droplets was governed by the stability of these charged droplets right after ejection or during their flight in the air. Using the electrospraying technique, we achieved conformal polymeric coatings with tailored microtopographies onto conductive surgical implants. The approach offers potential for controlling the surface topography of surgical implant devices to modulate their integration with surrounding tissues.     

Morphometric analysis of inflorescence phytoliths produced byAvena sativa L. andAvena strigos schreb

Morphometric analysis, the study of measurements of size and shape, has the potential to be an effective tool for phytolith analysis. This study reports the first attempt to apply the methodology to oats. In particular, this study was designed to determine if morphometric analysis could adequately discriminate between phytoliths produced in the inflorescence bracts of two species of oats, Avena sativa L. and Avena strigosa Schreb. Results indicate that while the taxa produce the same types of phytoliths, those phytoliths have significantly different measurements of size and shape. This suggests the technique has the potential to become a powerful research tool for investigators working in the wide variety of disciplines that utilize phytolith analysis.     

Pair-wise vs group-wise registration in statistical shape model construction: representation of physiological and pathological variability of bony surface morphology

Statistical shape models (SSM) of bony surfaces have been widely proposed in orthopedics, especially for anatomical bone modeling, joint kinematic analysis, staging of morphological abnormality, and pre- and intra-operative shape reconstruction. In the SSM computation, reference shape selection, shape registration and point correspondence computation are fundamental aspects determining the quality (generality, specificity and compactness) of the SSM. Such procedures can be made critical by the presence of large morphological dissimilarities within the surfaces, not only because of anthropometrical variability but also mainly due to pathological abnormalities. In this work, we proposed a SW pipeline for SSM construction based on pair-wise (PW) shape registration, which requires the a-priori selection of the reference shape, and on a custom iterative point correspondence algorithm. We addressed large morphological deformations in five different bony surface sets, namely proximal femur, distal femur, patella, proximal fibula and proximal tibia, extracted from a retrospective patient dataset. The technique was compared to a method from the literature, based on group-wise (GW) shape registration. As a main finding, the proposed technique provided generalization and specificity median errors, for all the five bony regions, lower than 2?mm. The comparative analysis provided basically similar results. Particularly, for the distal femur that was the shape affected by the largest pathological deformations, the differences in generalization, specificity and compactness were lower than 0.5?mm, 0.5?mm, and 1%, respectively. We can argue the proposed pipeline, along with the robust correspondence algorithm, is able to compute high-quality SSM of bony shapes, even affected by large morphological variability.     

林木数量性状基因定位中的若干问题

随着ＤＮＡ分子标记技术的迅速发展,ＱＴＬ定位已成为当前生物学研究领域的前沿。迄今已对许多种动、植物定位了许多重要性状的ＱＴＬ。这些研究促进了遗传学的发展,并将作为育种的新策略应用。与作物相比,林木ＱＴＬ定位有其特性。本文详细讨论了林木的生物学特性对ＱＴＬ定位的影响、ＱＴＬ定位的系谱设计和统计分析方法。     

On the cross-sectional shape of cellulose crystallites in Valonia ventricosa

The cross-sectional shape of the cellulose crystallites from the Valonia ventricosa cell wall has been investigated by electron microscopy, using negative staining and Bragg contrast in the bright field mode, with emphasis on this latter technique. The appearance of the cellulose crystallites in the electron microscope depends on their orientation. The cross-section of each cellulose crystal is almost square, with an average side of 18 nm. Sub-units corresponding to elementary fibrils were not detectable within the crystals. The differences between these results and those of earlier workers are discussed.