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A proposed model of knowledge representation and the coding of knowledge embedded in texts of Web published scientific articles
No full textThis article reports results of a research project with the aim of investigating the possibilities of electronic publishing journal articles both as text for human reading and in machine readable format recording the new knowledge contained in the article. This knowledge is identified with the scientific methodology elements such as problem, methodology, hypothesis, results, and conclusions. A model integrating all those elements is proposed which makes explicit and records in XML the article contribution, new knowledge and scientific novelty. The use of XML language to represent this knowledge enables its processing by intelligent software agents Despite the fact that electronic publishing is a common activity to scholars electronic journals are still based in the print model and do not take full advantage of the facilities offered by the Web environment. The proposed model aims to take advantage of these facilities enabling semantic retrieval and validation of the knowledge contained in articles. To validate and enhance the model a set of electronic journal articles were analyzed
Specific Nutritional Requirements of Coconut Calli (Cocos nucifera L.) during Somatic Embryogenesis Induction
No full textSummary Coconut calli were cultivated on two somatic embryogenesis induction media (SEIMs), differing in their 2,4-D content. Gain in dry matter weight, composition of soluble sugars within calli, but also pH and contents of glucose and macroelements in media were analysed at O, 15, 28, and 60 days of culture. Relationships between contents of endogenous sugars, on the one hand, and between contents of media macroelements, on the other hand, were analysed. Comparison was made with calli maintained on a control multiplication medium. Traits could be classified into 3 types of response with regard to condition of somatic embryogenesis induction (SEI condition). The first correspond to traits that were modified by the SEI condition and varying over time. Two phases were determined. During the first phase (TO-T15), soluble sugar contents within calli decreased over time. The higher the 2,4-D content in SEIMs, the higher the sugar contents. Consumption of glucose and macroelements in media was negligible. However, strong relationships in the contents of chloride, nitrate, phosphate, and sulfate were modified in the SEI condition. During the second phase (T15-T60, growth became lower in the SEI condition. Requirements for glucose, nitrate and phosphate and acidification .of media were higher. The relationship, determined by changes in nitrate and phosphate (R>0.98), was modified by the SEI conditions, showing a preferential consumption for nitrate in this case. Endogenous sucrose content decreased to become lower in the SEI condition. The higher the 2,4-D content in SEIMs, the higher the requirements for media compounds, the higher the contents of sugars within calli, but the lower the growth. The second type of response corresponded to traits modified by the SEI condition, but constant over time. It concerned relationships between contents of some cations in the media. The third type of response corresponded to traits unchanges by the SEI condition and over time. It concerned the high relationship contents of endogenous glucose and fructose (R = 0.88), and between contents of chloride, ammonium, calcium, magnesium, and potassium. Abbreviations: ANOVA = analysis of variance; ANCOVA = analysis of covariance; BAP = 6-benzylaminopurine; D M W = dry matter weight; FMW = fresh matter weight; % WC = percentage of water content; SEIM = somatic embryogenesis induction medium; TFMW = total fresh matter weight
A Service of zbw Spatial versus Social Mismatch: The Strength of Weak Ties Spatial versus Social Mismatch: The Strength of Weak Ties
No full textStandard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. www.econstor.eu The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent nonprofit organization supported by Deutsche Post Foundation. The center is associated with the University of Bonn and offers a stimulating research environment through its international network, workshops and conferences, data service, project support, research visits and doctoral program. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. Terms of use: Documents in D I S C U S S I O N P A P E R S E R I E S IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author
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No full textAbstract The processes of ossification sequences are poorly investigated for birds in general, even for domestic and experimental species and when it comes to the waterfowl it is almost negligible. Such sequences constitute a rich source of data on character evolution, and may even provide phylogenetic information. A pre-hatch developmental study on ossification sequences of axial and appendicular skeletal system in Kuttanad duck embryos was undertaken using 78 viable embryos. From day 3 to day 7 of incubation no ossification densities were seen both by alizarin red staining and computerized radiography. The first indication of ossification as small ossification centers in skull bones, clavicle, scapula, humerus, radius and ulna in forelimb and ilium, pubis femur and fibula in hind limb were observed on the 9 th day of incubation. The ossification of the body of the ribs started at the 11 th day of incubation towards the proximal extremity. On day 13 th the ossification process of vertebrae was started from cervical end. The variation in appearance of the ossification centers in different bones at different stages of incubation period suggests relative importance of phylogeny to the sequences
Mutation analysis of the ferritin L-chain gene in age-related cataract
No full textPurpose: To investigate whether acquired somatic mutations in the iron response element of the ferritin L-chain gene account for the age-related cataract. Methods: The 15 most prevalent point mutations causing hereditary hyperferritinemia cataract syndrome (HHCS) were screened in patients with age-related cataract using MALDI-TOF Mass Spectrometry. DNA samples were obtained from the lens capsules of patients following cataract surgery, and subjected to PCR amplification. Products were analyzed by a Sequenom® mass spectrometer, and classified as a mutation or wild type according to molecular weight. For a positive control, L-ferritin G32T mutation detected by direct sequencing in 3 members of an Israeli family known to be affected by HHCS was used. Results: DNA samples were isolated from the lens capsules of 90 patients, mean age 73.86, and screened for L-ferritin mutations. While the G32T mutation was detected in all 3 positive control cases, all other patients were negative for the 15 mutations. Conclusions: Somatic mutations in the iron response elements (IRE) of the L-ferritin gene are infrequent in the age-related cataract. The role of L-ferritin genetic variations in the pathogenesis of age-related cataract is yet to be explored
Qualitative and Quantitative Performance of 18 F-FDG-PET/MRI versus 18 F-FDG-PET/CT in Patients with Head and Neck Cancer
Full text linkABSTRACT BACKGROUND AND PURPOSE: MR imaging and PET/CT are integrated in the work-up of head and neck cancer patients. The hybrid imaging technology 18 F-FDG-PET/MR imaging combining morphological and functional information might be attractive in this patien
eneRgy expendituRe duRing gait in patients witH mucopolysaccHaRidosis
Full text linkABSTRACT Objective: The aim of this study is to evaluate energy expenditure in gait by mucopolysaccharidosis affected patients by means of a simple and adequate to the clinical environment methodology. Methods: A cross-sectional study was carried out comparing energy expenditure during gait in 19 patients suffering from mucopolysaccharidosis (MPS Group) with 19 asymptomatic control individuals (Control Group). Energy expenditure was measured in calories (cal) using a Polar telemetric watch (model FT7) during a 50 meter walk. Variables such as age, weight, height, body mass index (BMI), initial hart rate, final hart rate, and walking time, were recorded. Results: MPS Group showed a mean energy expenditure during gait of 2.84 cal (±1,01), versus 1.42 cal (±0,51), 100% higher than the Control Group; MPS also presented increased initial hart rate (22% higher), final hart rate (13% higher) and walking time (13% higher). Conclusions: Energy expenditure during gait in MPS patients was two times higher than control individuals; the methodology used showed to be a promising alternative, also adequate to the standard clinical environment. Level of Evidence III, Cross-sectional Comparative Study
Comparing Reuse Mechanisms for Model Transformation Languages: Design for an Empirical Study
Full text linkABSTRACT Reuse mechanisms for model transformation languages help avoid duplication, thereby increasing maintainability and enabling a more systematic overall development process. As the introduction of such reuse mechanisms to model transformation languages is still in its preliminary stages, however, language designers are currently faced with the challenge of choosing from amongst diverse proposed approaches. Although there are a few surveys comparing syntactic and semantic differences, there is still a need for empirical studies on the actual effectiveness of different reuse mechanisms for transformation developers. In this paper, therefore, we present a study design for a controlled experiment to investigate the benefits and drawbacks of two specific reuse mechanisms for model transformation languages: rule refinement and variability-based rules. Both mechanisms are tailored to graph-based model transformation languages, yet represent two contrasting reuse paradigms: modularizing rules by composing them from smaller, shared fragments, versus maintaining a single, integrated representation via variability annotations. We propose to compare these two approaches using comprehension and bug-finding tasks to investigate understandability, and bug-fixing and modification tasks to study changeability
