• Title/Summary/Keyword: Knowledge Structures

Search Result 728, Processing Time 0.027 seconds

Morphometric Study of the Korean Adult Pituitary Glands and the Diaphragma Sellae

  • Ju, Kyo-Sung;Bae, Hack-Gun;Park, Hyung-Ki;Chang, Jae-Chil;Choi, Soon-Kwan;Sim, Ki-Bum
    • Journal of Korean Neurosurgical Society
    • /
    • v.47 no.1
    • /
    • pp.42-47
    • /
    • 2010
  • Objective: To investigate the morphometric characteristics of the pituitary gland and diaphragma sellae in Korean adults. Methods: Using the 33 formaline fixed adult cadavers (23 male, 10 female), the measurements were taken at the diaphragma sellae and pituitary gland. The authors investigated the relationship between dura and structures surrounding pituitary gland, morphometric aspects of pituitary gland and stalk, and morphometric aspect of central opening of diaphragma sellae. Results: The boundary between the lateral surface of pituitary gland and the medial wall of cavernous sinus was formed by the thin dural layer and pituitary capsule. The pituitary capsule adherent tightly to the pituitary gland was observed to continue from the diaphragma sellae. Mean width, length, and height of the pituitary gland were 14.3${\pm}$2.1, 7.9${\pm}$1.3, and 6.0${\pm}$0.9 mm in anterior lobes, and 8.7${\pm}$1.7, 2.9${\pm}$1.1, and 5.8${\pm}$1.0 mm in posterior lobes, respectively. Although all dimensions of anterior lobe in female were slightly larger than those in male, statistical significance was noted in only longitudinal dimension. The ratio of posterior lobe to the whole length of pituitary gland was about 27%. The mean thickness of pituitary stalk was 2 mm. The diaphragmal opening was 5 mm or more in 26 (78.8%) of 33 specimen. The opening was round in 60.6% of the specimen, and elliptical oriented in an anterior-posterior or transverse direction in 39.4%. Conclusion: These results provide the safe anatomical knowledge during the transsphenoidal surgery and may be helpful to access the possibility of the development of empty sella syndrome.

Are Cryptic Species Real?

  • Crous, Pedro W.
    • 한국균학회소식:학술대회논문집
    • /
    • 2014.10a
    • /
    • pp.29-29
    • /
    • 2014
  • Since Darwin and Wallace introduced the concept on the evolution of species, scientists have been furiously debating what species are, and how to define them. This basic yet intriguing question has bothered us ever since, as communicating to fellow biologists about fungal species is the very cornerstone of mycology. For the species presently known, this has largely been accomplished via Latin binomials linked to morphology in the absence of DNA barcodes. In recent years mycologists have embraced the ribosomal ITS as official barcode region for Fungi, and this locus is also mainly used in environmental pyrosequencing studies. Furthermore, DNA data can now also be used to describe sterile species in the absence or lack of distinct morphological structures. Recent developments such as the registration of names in MycoBank, and linking the phenotype to the genotype, have significantly changed the face of fungal systematics. By employing the Consolidated Species Concept, incorporating genealogical concordance, ecology and morphology, robust species recognition is now possible. Several international initiatives have since built on these developments, such as the DNA barcoding of holdings of Biological Resource Centres, followed by the Genera of Fungi Project, aiming to recollect, and epitypify all type species of all genera. What these data have revealed, is that most genera are poly- and paraphyletic, and that morphological species normally encompass several genetic entities, which may be cryptic species. Once we provide a stable genetic backbone capturing our existing knowledge of the past 250 years, we will be able to accommodate novelties obtained via environmental sequencing platforms. Being able to communicate these species to other biologists in a clear manner that is DNA-based, will enable scientists to elucidate the importance, role and ecological interactions that these fungi have on our planet.

  • PDF

Chemical Constituents from the Aerial Parts of Vernonia cinerea L. and Their Anti-Inflammatory Activity (베르노니아 시네레아 지상부의 화학 성분 및 항염증 활성)

  • Youn, Ui Joung;Chang, Leng Chee
    • Korean Journal of Medicinal Crop Science
    • /
    • v.24 no.6
    • /
    • pp.437-443
    • /
    • 2016
  • Background: Previous phytochemical studies of whole Vernonia cinerea L. plants have identified sesquiterpene lactones, sterols, and triterpenes, which possess anticancer, antifeedant, and antimalarial activities. However, there are no reports of other types of bioactive metabolites. Therefore, the present study aimed to identify phenolic compounds with anti-inflammatory activity in the aerial parts of the plant. Methods and Results: Compounds were isolated from the aerial parts of V. cinerea using a silica and C-18 gel columns and semi-preparative HPLC instrument, and the structures of the compounds were determined using one- and two- dimension nuclear magnetic resonance spectroscopy and mass spectroscopy. The chloroform soluble extracts and isolated compounds were evaluated for their anti-inflammatory potential based on their ability to inhibit nitric oxide production and $TNF-{\alpha}$ induced $NF-{\kappa}B$ activity. Conclusions: Phytochemical study of the aerial parts of V. cinerea led to the isolation of six phenolic compounds. Compound 1 was a major metabolite, and to the best of our knowledge, compounds 2 - 6 were isolated from V.cinerea for the first time. Among the isolates, compounds 1 and 3 exhibited $TNF-{\alpha}$-induced $NF-{\kappa}B$ activity with $IC_{50}$ values of 7.5 and 11.5 M, respectively, and the inhibitory activity of phenyl propanoid compound 3 on $TNF-{\alpha}$-induced $NF-{\kappa}B$ was evaluated for the first time.

Ultrasound Related Anatomy and Biomechanics of Shoulder Joint (초음파 영상과 관련된 견관절 해부학 및 생역학)

  • Kim, Yang-Soo;Lee, Jae-Young
    • The Journal of Korean Orthopaedic Ultrasound Society
    • /
    • v.1 no.2
    • /
    • pp.112-116
    • /
    • 2008
  • Ultrasonography of shoulder joint recently enlarges its utility since the knowledge of the shoulder disease is increased by numerous researches. Ultrasonography is not only noninvasive, safe, and relatively cheap, but also an unique modality that can monitor tendon movement during shoulder motion. Sonographic examination generally starts from the front side of the shoulder joint and finishes at back side in sitting position. Many structures in shoulder joint such as muscles, ligaments, glenoid labrum, bone, and especially rotator cuff tendon can be examined by ultrasonography. The rotator cuff is a motion unit consisted with subscapularis, supraspinatus, infraspinatus, and teres minor muscles. It functions as fulcrum and compresses the humeral head onto the glenoid, and steers for shoulder joint.

  • PDF

A LONGITUDINAL ROENTGENO-CEPHALOMETRIC STUDY ON THE INTERMAXILLARY SPACE OF NORMAL KOREAN CHILDREN AGED FROM 6 TO 11 YEARS (두부방사선 계측사진에 의한 6세에서 11세 사이의 악간 공간에 관한 누년적 연구)

  • Ryu, Young-Kyu
    • The korean journal of orthodontics
    • /
    • v.15 no.1
    • /
    • pp.141-148
    • /
    • 1985
  • It has been a long time since the cephalometrics was introduced to orthodontic field for diagnosis and treatment planning, but it's main concern was limited to hard, skeletodental tissue. It is well known that perioral and facial soft tissue determine the position of individual teeth and that the abnormality in size and shape of the soft tissue are able to cause malformed occlusion. Because of our lack of knowledge about resultant morphologic changes in the relationship between skeletal pattern and specific pattern of lingual and facial muscles, we can't help setting greater value on only abnormalities of teeth in the skeletal interrelationship. In a point of view that the orthodontist is dealing primarily with muscular structures around the dentition, the tongue, lips, and cheeks, therefore it may be desirable to estimate these structure and their potential influence on the dentition on developmental and time base. The author hit upon on idea of the aspect above, so studied on the intermaxillary space and tongue space and this study used the data from cephalometric films of 33 male and 40 female subject aged from 6 to 11 years of normal Korean children following results were obtained: 1. Means and standard deviation of Korean children were obtained. 2. Yearly increment of each variables were obtained. 3. There is the correlationship more than average among the variables except posterior intermaxillary height item. 4. There are differences between male children and female children in all variables except posterior intermaxillary space item. 5. All variables increased as the age increased except posterior intermaxillary height item of male children.

  • PDF

Functional Neuroanatomy of Memory (기억의 기능적 신경 해부학)

  • Lee, Sung-Hoon
    • Sleep Medicine and Psychophysiology
    • /
    • v.4 no.1
    • /
    • pp.15-28
    • /
    • 1997
  • Longterm memory is encoded in the neuronal connectivities of the brain. The most successful models of human memory in their operations are models of distributed and self-organized associative memory, which are founded in the principle of simulaneous convergence in network formation. Memory is not perceived as the qualities inherent in physical objects or events, but as a set of relations previously established in a neural net by simultaneousy occuring experiences. When it is easy to find correlations with existing neural networks through analysis of network structures, memory is automatically encoded in cerebral cortex. However, in the emergence of informations which are complicated to classify and correlated with existing networks, and conflictual with other networks, those informations are sent to the subcortex including hippocampus. Memory is stored in the form of templates distributed across several different cortical regions. The hippocampus provides detailed maps for the conjoint binding and calling up of widely distributed informations. Knowledge about the distribution of correlated networks can transform the existing networks into new one. Then, hippocampus consolidats new formed network. Amygdala may enable the emotions to influence the information processing and memory as well as providing the visceral informations to them. Cortico-striatal-pallido-thalamo-cortical loop also play an important role in memory function with analysis of language and concept. In case of difficulty in processing in spite of parallel process of informations, frontal lobe organizes theses complicated informations of network analysis through temporal processing. With understanding of brain mechanism of memory and information processing, the brain mechanism of mental phenomena including psychopathology can be better explained in terms of neurobiology and meuropsychology.

  • PDF

An ontology analysis and error detection tool based on concept hierarchy structures (개념계층구조에 기반한 온톨로지 분석 및 오류검출도구)

  • Hwang, Suk-Hyung
    • The KIPS Transactions:PartD
    • /
    • v.15D no.4
    • /
    • pp.557-568
    • /
    • 2008
  • An ontology as the core element of Semantic Web is a formal specification of a conceptualization of shared domain knowledge. The use of well-defined ontologies can increase the quality of interoperable information systems in the area of Semantic Web. However, in practice, it is not easy to develop high-quality ontologies which have no errors. Therefore, with methodologies for ontology design, various methods or tools for ontology analysis supporting for error-detection might be very helpful for ontology developers. In this paper, we propose a novel approach for analyzing the core constructs of ontology based on the Formal Concept Analysis and develop a tool that supports error-checking ontologies. Our approach can serve not only as a guidance to modify the existing ontologies, but also as a valuable tool in developing high-quality ontologies.

A component method model for blind-bolts with headed anchors in tension

  • Pitrakkos, Theodoros;Tizani, Walid
    • Steel and Composite Structures
    • /
    • v.18 no.5
    • /
    • pp.1305-1330
    • /
    • 2015
  • The successful application of the component-based approach - widely used to model structural joints - requires knowledge of the mechanical properties of the constitutive joint components, including an appropriate assembly procedure to derive the joint properties. This paper presents a component-method model for a structural joint component that is located in the tension zone of blind-bolted connections to concrete-filled tubular steel profiles. The model relates to the response of blind-bolts with headed anchors under monotonic loading, and the blind-bolt is termed the "Extended Hollo-bolt". Experimental data is used to develop the model, with the data being collected in a manner such that constitutive models were characterised for the principal elements which contribute to the global deformability of the connector. The model, based on a system of spring elements, incorporates pre-load and deformation from various parts of the blind-bolt: (i) the internal bolt elongation; (ii) the connector's expanding sleeves element; and (iii) the connector's mechanical anchorage element. The characteristics of these elements are determined on the basis of piecewise functions, accounting for basic geometrical and mechanical properties such as the strength of the concrete applied to the tube, the connection clamping length, and the size and class of the blind-bolt's internal bolt. An assembly process is then detailed to establish the model for the elastic and inelastic behaviour of the component. Comparisons of model predictions with experimental data show that the proposed model can predict with sufficient accuracy the response of the component. The model furthers the development of a full and detailed design method for an original connection technology.

Theoretical analysis of Y-shape bridge and application

  • Lu, Peng-Zhen;Zhang, Jun-Ping;Zhao, Ren-Da;Huang, Hai-Yun
    • Structural Engineering and Mechanics
    • /
    • v.31 no.2
    • /
    • pp.137-152
    • /
    • 2009
  • Mechanic behavior of Y-shape thin-walled box girder bridge structure is complex, so one can not exactly hold the mechanical behavior of the Y-shape thin-walled box girder bridge structure through general calculation theory and analytical method. To hold the mechanical behavior better, based on elementary beam theory, by increasing the degree of freedom analytical method, taking account of restrained torsiondistortion angledistortion warp and shearing lag effect at the same time, authors obtain a thin-walled box beam analytical element of 10 degrees of freedom of every node, derive stiffness matrix of the element, and code a finite element procedure. In addition, authors combine the obtained procedure with spatial grillage analytical method, meanwhile, they build a new analytical method that is the spatial thin-walled box girder element grillage analysis method. In order to validate the precision of the obtained analysis method, authors analyze a type Y-shape thin-walled box girder bridge structure according to the elementary beam theory analytical method, the shell theory analytical method and the spatial thin-walled box girder element grillage analysis method respectively. At last, authors test a type Y-shape thin-walled box girder bridge structure. Comparisons of the results of theory analysis with the experimental text show that the spatial thin-walled box girder element grillage analysis method is simple and exact. The research results are helpful for the knowledge of the mechanics property of these Y-shape thin-walled box girder bridge structures.

Opportunities for Joint Cooperation in R&D for FEALAC Countries: On Nanotechnology and Biotechnology

  • Trujillo, Ivan Montenegro;Jimenez, Edgar E Gonzalez;Ospina, Monica Botero
    • STI Policy Review
    • /
    • v.7 no.2
    • /
    • pp.106-131
    • /
    • 2016
  • The general purpose of this paper is to identify opportunities for and to measure existing collaboration on research and development between institutions from the countries of Asia and Latin America in FEALAC's framework, in the fields of biotechnology and nanotechnology and their convergence. The methodological approach includes scientific and technological surveillance and research seeking to identify both the R&D and innovation capacities of the countries as well as the degree of international cooperation between countries of the two regions; case studies and a study of the governance framework of international collaboration in R&D about issues considered global challenges. The study has three main findings. First, nanotechnology, biotechnology and their convergence contribute to solving the problem of contamination by heavy metals affecting most of the countries that are part of FEALAC and to address problems arising from the accelerated rate of energy consumption, which also contributes to environmental damage. In this scenario, important business opportunities arise from the adaptation and development of bio-refinery technologies. Second, the scientific relationship between FEALAC countries, mainly between Asian and Latin American countries, is weak as can be seen in research for articles and patents. But there is plenty of room and potential for improvement. Third, current and upcoming joint R&D programs and projects should be linked both to existing governance structures and to new ones that serve as experiments of STI public policy regarding innovative management of intellectual property and capacity building. Practical implications are included in lessons learned and a set of recommendations involving a couple of proposals. One proposal calls for research and innovation in promising fields for international cooperation. Another proposal creates mechanisms in the governance framework for sharing knowledge, capacity building, and funding.