A comparison of back-calculated lengths of silver carp derived from bony structures

Linear relationships were found between body length–scale radius, body length-cleithrum length and body length-urohyal length ( r =0·949, 0·984 and 0·974 respectively) in silver carp Hypophthalmichthys molitrix. Out of 180 comparisons, which were made between different methods of back-calculating length and ageing structures at ages 2-7 years, the differences were not significant ( P ≥ 0·05) in 132 (73·3%) cases. There were no significant differences among different methods in older age classes and between the Fraser-Lee method and body proportional method (BPH) at all ages. The results demonstrated that in all structures, back-calculated lengths estimated by the scale proportional hypotheses (SPH) were less than the other methods. For scales, SPH was similar to the direct proportional method of Dahl-Lea (DPM) but for cleithra and urohyal bones it was similar to BPH and Fraser-Lee. As the fish increased in age, the differences between back-calculated lengths decreased. When lengths were back-calculated using cleithra and urohyal bones, differences between the structures at age 2 years were 17 mm from DPM, 33 mm from SPH, 37 mm from BPH and 37 mm from Fraser-Lee, while at age 8 years mean differences were 7 mm from DPM and 8 mm from the SPH, BPH and Fraser-Lee methods. It is suggested that the differences would be less if: (1) back-calculated lengths are based on a large number of random samples; (2) measurements of scale radius, cleithrum length and urohyal length were precise; (3) determination of focus or origin were precise; (4) the sampling of scales were from the same row.     

Secretions of stingless bees: cephalic secretions of two Frieseomelitta species

Gas chromatographic and mass spectrometric analysis of the volatile compounds in the mandibular glands of Frieseomelitta varia and the heads of Frieseomelitta silvestrii have revealed relatively simple or more complex mixtures of volatile oxygenated compounds. 2-Alkanols were found to be important components for both species. In F. varia the composition was essentially the same in samples from two widely separated areas and there were small differences between callows and mature, foraging bees. The first electroantennographic studies on stingless bees, using hexane extracts of heads of both species, have demonstrated a response in the workers’ antennae to these, as well as to the pure compounds 2-heptanol and 2-nonanol .     

Which measures of diaphyseal robusticity are robust? A comparison of external methods of quantifying the strength of long bone diaphyses to cross‐sectional geometric properties

Measures of diaphyseal robusticity have commonly been used to investigate differences in bone strength related to body size, behavior, climate, and other factors. The most common methods of quantifying robusticity involve external diameters, or cross-sectional geometry. The data derived from these different methods are often used to address similar research questions, yet the compatibility of the resulting data has not been thoroughly tested. This study provides the first systematic comparison of externally derived measures of postcranial robusticity, with those based upon cross-sectional geometry. It includes sections taken throughout the skeleton, comparisons of prediction errors associated with different measurements, and analysis of the implications of different methods of body size standardization on the prediction of relative bone strength. While the results show reasonable correlations between diaphyseal diameters and strengths derived from cross-sectional geometry, considerable prediction errors are found in many cases. A new approach to externally based quantification of diaphyseal robusticity based upon moulding of sub-periosteal contours is proposed. This method maximizes correlation with cross-sectional geometry (r(2) = .998) and minimizes prediction errors in all cases. The results underscore the importance of accurate periosteal measurement in the quantification of bone strength, and suggest that, regardless of theoretical scaling predictions, external area based robusticity estimates involving the product of diaphyseal diameters are most directly comparable to cross-sectional geometric properties when they are standardized using the product of body mass and bone length.     

Comparison of maternal lineage and biogeographic analyses of ancient and modern Hungarian populations

The Hungarian language belongs to the Finno-Ugric branch of the Uralic family, but Hungarian speakers have been living in Central Europe for more than 1000 years, surrounded by speakers of unrelated Indo-European languages. In order to study the continuity in maternal lineage between ancient and modern Hungarian populations, polymorphisms in the HVSI and protein coding regions of mitochondrial DNA sequences of 27 ancient samples (10th-11th centuries), 101 modern Hungarian, and 76 modern Hungarian-speaking Sekler samples from Transylvania were analyzed. The data were compared with sequences derived from 57 European and Asian populations, including Finno-Ugric populations, and statistical analyses were performed to investigate their genetic relationships. Only 2 of 27 ancient Hungarian samples are unambiguously Asian: the rest belong to one of the western Eurasian haplogroups, but some Asian affinities, and the genetic effect of populations who came into contact with ancient Hungarians during their migrations are seen. Strong differences appear when the ancient Hungarian samples are analyzed according to apparent social status, as judged by grave goods. Commoners show a predominance of mtDNA haplotypes and haplogroups (H, R, T), common in west Eurasia, while high-status individuals, presumably conquering Hungarians, show a more heterogeneous haplogroup distribution, with haplogroups (N1a, X) which are present at very low frequencies in modern worldwide populations and are absent in recent Hungarian and Sekler populations. Modern Hungarian-speaking populations seem to be specifically European. Our findings demonstrate that significant genetic differences exist between the ancient and recent Hungarian-speaking populations, and no genetic continuity is seen.     

Sesamoids in tetrapods: the origin of new skeletal morphologies

Along with supernumerary bones, sesamoids, defined as any organized intratendinous/intraligamentous structure, including those composed of fibrocartilage, adjacent to an articulation or joint, have been frequently considered as enigmatic structures associated with the joints of the skeletal system of vertebrates. This review allows us to propose a dynamic model to account for part of skeletal phenotypic diversity: during evolution, sesamoids can become displaced, attaching to and detaching from the long bone epiphyses and diaphysis. Epiphyses, apophyses and detached sesamoids are able to transform into each other, contributing to the phenotypic variability of the tetrapod skeleton. This dynamic model is a new paradigm to delineate the contribution of sesamoids to skeletal diversity. Herein, we first present a historical approach to the study of sesamoids, discussing the genetic versus epigenetic theories of their genesis and growth. Second, we construct a dynamic model. Third, we present a summary of literature on sesamoids of the main groups of tetrapods, including veterinary and human clinical contributions, which are the best‐studied aspects of sesamoids in recent decades. Finally, we discuss the identity of certain structures that have been labelled as sesamoids despite insufficient formal testing of homology. We also propose a new definition to help the identification of sesamoids in general. This review is particularly timely, given the recent increasing interest and research activity into the developmental biology and mechanics of sesamoids. With this updated and integrative discussion, we hope to pave the way to improve the understanding of sesamoid biology and evolution.     

青海地区藏汉族人群下颌第二磨牙根管形态的锥形束CT研究

目的:采用锥形束CT(Cone Beam CT,CBCT)技术探讨青海地区藏汉族人群下颌第二磨牙根管形态、数量以及C型根管发生率和髓腔差值的异同。方法:从2016年5月到2018年12月青大附院口腔门诊牙齿CBCT扫描结果中选择藏、汉民下颌第二磨牙各300颗,其中汉族150例,藏族150例。按照Vertucci分类对根管进行分型,探究青海地区藏、汉族人群下颌第二磨牙根管形态特点,同时对牙根类型、C型根管数量和发生率进行统计研究。结果:青海地区藏汉族人群下颌第二磨牙牙根类型以双根牙为主,且其在藏族人群中的发生率高于汉族人群。青海地区藏汉族人群下颌第二磨牙的根管分型以Ⅰ型和C型根管所占比例最高。在青海地区汉族人群和藏族人群下颌第二磨牙中,C形根管所占比率分别为40.7%和27.0%,汉族人群C型根管发生率显著高于藏族人群(P0.05)。在青海地区藏汉人群下颌第二磨牙中,女性的发生率显著高于男性(P0.05)。青海地区藏族人群的MB-DB、DB-P平均值显著高于汉族人群(P0.05)。结论:青海地区藏汉族人群下颌第二磨牙根管形态基本类似,C型根管发生率汉族人群是远远大于藏族人群的,具有一定的种族差异性。但是C型根管发生率在青海地区藏汉人群中都是女性大于男性。同时藏族人群髓腔差值也具有一定的种族差异性。     

Distinctive neural bones in Dipsochelys giant tortoises: Structural and taxonomic characters

The carapace of turtles consists of characteristic dermal bones (neurals, costal, and pleurals) and epidermal scutes. The variation in neural bone configuration in the Indian Ocean giant tortoise genus Dipsochelys is assessed. Study of 42 specimens supports earlier reports that variation is largely restricted to the anterior and posterior bones. Each species of Dipsochelys possesses a distinctive arrangement of neural bones. The configurations are related to the carapace shape with the relative width of the bones and interdigitating processes influencing structural stability. An exceptional configuration is described for the saddle‐backed species D. arnoldi, wherein this configuration arises from musculoskeletal adaptations for browsing in this species. J. Morphol. 240:33–37, 1999. © 1999 Wiley‐Liss, Inc.     

Parathyroid hormone promotes cartilage healing after free reduction of mandibular condylar fractures by upregulating Sox9

After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1–34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7–21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.     

膝部长骨干骺融合的X线观察与分析——西安市学生膝部长骨干骺融合的研究

本文根据西安市1361名学生的X线拍片观察,得出了西安市学生膝部长骨的干骺融合时间和各年龄组的融合率,并与其他学者的报告做了比较,探讨了近年来身高增长的原因。