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101.
Biplane 2D-3D registration approaches have been used for measuring 3D, in vivo glenohumeral (GH) joint kinematics. Computed tomography (CT) has become the gold standard for reconstructing 3D bone models, as it provides high geometric accuracy and similar tissue contrast to video-radiography. Alternatively, magnetic resonance imaging (MRI) would not expose subjects to radiation and provides the ability to add cartilage and other soft tissues to the models. However, the accuracy of MRI-based 2D-3D registration for quantifying glenohumeral kinematics is unknown. We developed an automatic 2D-3D registration program that works with both CT- and MRI-based image volumes for quantifying joint motions. The purpose of this study was to use the proposed 2D-3D auto-registration algorithm to describe the humerus and scapula tracking accuracy of CT- and MRI-based registration relative to radiostereometric analysis (RSA) during dynamic biplanar video-radiography. The GH kinematic accuracy (RMS error) was 0.6–1.0 mm and 0.6–2.2° for the CT-based registration and 1.4–2.2 mm and 1.2–2.6° for MRI-based registration. Higher kinematic accuracy of CT-based registration was expected as MRI provides lower spatial resolution and bone contrast as compared to CT and suffers from spatial distortions. However, the MRI-based registration is within an acceptable accuracy for many clinical research questions. 相似文献
102.
Andrew Fairbairn Danièle Martinoli Ann Butler Gordon Hillman 《Vegetation History and Archaeobotany》2007,16(6):467-479
Full analysis of eight seed samples collected in the 1960's excavations at Neolithic Çatalhöyük East, Turkey, is presented. Detailed investigation of the composition and context of the samples suggests that the Neolithic population collected, processed and stored seeds from Capsella sp. and Descurainia sp. (wild crucifers) for food use. In addition seeds of Vicia/Lathyrus sp. (wild vetch), Helianthemum spp. and Taeniatherum caput-medusae mixed with Eremopyrum type (grasses) were also found, some of which may have been used for food or other purposes. The analysis demonstrates that wild seed exploitation was a regular part of subsistence practice alongside the economic staple of crop production, and again demonstrates how diverse plant use practices were at the site. 相似文献
103.
M. ech †‡ J. Kubeka † J. Frouzová V. Dratík † M. Kratochvíl † J. Jaroík 《Journal of fish biology》2007,70(4):1109-1119
Previous studies have shown that under normal spring conditions, the layer of bathypelagic perch Perca fluviatilis fry (BPF) is equally distributed along most of the longitudinal profile of reservoirs. In the first half of June 2004, local flooding entering the large canyon‐shaped Orlík Reservoir (Czech Republic) completely flushed out the existing fry community from the 31 km long riverine part of the reservoir. The pelagic zone in this reach was then recolonized by cyprinid (mainly roach Rutilus rutilus and bream Abramis brama) fry being of either littoral or riverine origin. Subsequently, the BPF layer was recorded only in the 22 km long lacustrine part of the reservoir. In the upper reach of this part where, due to the sudden increase in volume, the water current slowed down rapidly and fry originating from both riverine and central parts of the reservoir gathered in high numbers, two distinct BPF layers were observed. During mid‐day, the upper BPF layer, created predominantly by shoaling fishes (abundance >126 000 individuals ha?1), occurred between 6 and 10 m. A second, lower BPF layer, created by non‐shoaling fishes exclusively (30 000 individuals ha?1), was recorded between 12 and 17 m depth. Both upper and lower BPF layer were composed of perch (69·6 and 66·8% in abundance respectively) and zander Sander lucioperca (29·8 and 28·6% in abundance respectively). In the lower BPF layer, ruffe Gymnocephalus cernuus also contributed considerably to the fry assemblage (4·0% in abundance). Perch from the upper BPF layer (mean 25·1 mm total length, LT) did not differ in size from perch from the lower BPF layer (mean 25·0 mm LT). Similarly, zander from the upper BPF layer (mean 27·2 mm LT) were almost the same size as those from the lower BPF layer (mean 26·9 mm LT). Perch from both BPF layers, however, were noticeably smaller than zander. The results from acoustic survey and complementary net catches suggest that no epipelagic perch fry were found in the reservoir where thermal stratification had been destroyed by flooding and windy weather. 相似文献
104.
基于28S rDNA部分序列的石磺科系统发育研究 总被引:1,自引:0,他引:1
采用PCR技术对采集自中国大陆沿海5地8个群体石磺的28S rDNA部分序列进行扩增。将测序结果与Gen-Bank中的另外3条石磺科贝类的对应序列一起,以小鼠28S rDNA基因序列进行参照,截取D1、D2、D3区域,拼接后进行比对分析。在获得的689bp的序列中,有76个变异位点,28个简约信息位点,A+T平均含量为30.9%,C+G平均含量为69.0%。以分类关系较近的菊花螺科(Siphonaria alternate)为外群,用NJ、MP、ML和贝叶斯法构建分子系统树。4种方法得到的进化树拓扑结构很相似,得到的结果也与沈和定提出的中国大陆沿海石磺科贝类可划分为Peronia、Platevindex、Onchidium、Paraoncidium4个属的观点基本一致。同时,28S rDNA部分序列的系统分析还显示,4个属中Peronia属与Paraoncidium属亲缘关系较近,Platevindex属与Onchidium属关系比较近。 相似文献
105.
Christelle David Laurent Bischoff Hervé Meudal Catherine Llorens-Cortes Bernard Pierre Roques Marie-Claude Fournié-Zaluski 《Letters in Peptide Science》1997,4(4-6):411-414
In order to study the physiological role of aminopeptidase A (APA),several -mercapto--amino acyl dipeptides were synthesized toobtain compounds having a high affinity for APA and a high selectivityversus aminopeptidase N (APN). Sulfonamide and carboxylate moieties whichhave been shown to be recognized by the S1 subsite of theenzyme were introduced on the side chain of the -mercapto--aminoacyl sub-unit, the latter being coupled to dipeptides optimized to interactwith the S1 andS2 subsites by means of combinatorialchemistry. Good affinities (16 nM) were obtained, the selectivity factorsbeing up to 160-fold versus APN. 相似文献
106.
Iraldo Bello Anaiza Perez Ana Maria Torres Maria Victoria Hernández Pedro López Saura 《Biotherapy》1998,11(1):53-57
Soluble receptors for hormones and cytokines have beendescribed. They can serve as natural blockers of theirrespective ligands. The natural soluble interferongamma receptor (sIFNR) has been isolated andcharacterized only in urine. Chromatography of human(hu) plasma from rheumatoid arthritis (RA) patientsand controls on immobilized hu IFN orantibodies against IFN R chainpermitted us to isolate the sIFNR. Thereceptor isolated from one control is a protein witha molecular weight between 60-67 kDa depending on thepresence of reducing agents. We detected asignificantly higher level of plasma sIFNR inpatients with rheumatoid arthritis than in apparentlyhealthy subjects. 相似文献
107.
Roles of Escherichia coli heat shock proteins DnaK, DnaJ and GrpE in mini-F plasmid replication 总被引:5,自引:0,他引:5
Summary A subset of Escherichia coli heat shock proteins, DnaK, DnaJ and GrpE were shown to be required for replication of mini-F plasmid. Strains of E. coli K12 carrying a missense mutation or deletion in the dnaK, dnaJ, or grpE gene were virtually unable to be transformed by mini-F DNA at the temperature (30° C) that permits cell growth. When excess amounts of the replication initiator protein (repE gene product) of mini-F were provided by means of a multicopy plasmid carrying repE, these mutant bacteria became capable of supporting mini-F replication under the same conditions. However, the copy number of a high copy number mini-F plasmid was reduced in these mutant bacteria as compared with the wild type in the presence of excess RepE protein. Furthermore, mini-F plasmid mutants that produce altered initiator protein and exhibit a very high copy number were able to replicate in strains deficient in any of the above heat shock proteins. These results indicate that the subset of heat shock proteins (DnaK, DnaJ and GrpE) play essential roles that help the functioning of the RepE initiator protein in mini-F DNA replication. 相似文献
108.
109.
Milka Elshishka Stela Lazarova Georgi Radoslavov Petar Hristov Vlada K. Peneva 《ZooKeys》2015,(511):25-68
The taxonomic position of two antarctic dorylaimid species Amblydorylaimus
isokaryon (Loof, 1975) Andrássy, 1998 and Pararhyssocolpus
paradoxus (Loof, 1975), gen. n., comb. n. are discussed on the basis of morphological, including SEM study, morphometric, postembryonic and sequence data of 18S rDNA and the D2-D3 expansion fragments of large subunit rDNA. The evolutionary trees inferred from 18S sequences show insufficient resolution to determine the assignment of the two species to particular families, moreover Pararhyssocolpus
paradoxus
gen. n., comb. n. (=Rhyssocolpus
paradoxus) previously regarded as a member of Nordiidae or Qudsianematidae, showed distant relationship both to Rhyssocolpus
vinciguerrae and Eudorylaimus spp. The phylogram inferred from 28S sequences revealed that Amblydorylaimus
isokaryon is a member of a well-supported group comprised of several Aporcelaimellus spp., while, no close relationships could be revealed for the Pararhyssocolpus
paradoxus
gen. n., comb. n. to any nematode genus. On the basis of molecular data and morphological characteristics, some taxonomic changes are proposed. Amblydorylaimus
isokaryon is transferred from family Qudsianematidae to family Aporcelaimidae, and a new monotypic genus Pararhyssocolpus
gen. n. is proposed, attributed to Pararhyssocolpidae
fam. n. The diagnosis of the new family is provided together with emended diagnosis of the genera Amblydorylaimus and Pararhyssocolpus
gen. n. Data concerning distribution of these endemic genera in the Antarctic region are also given. 相似文献