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Insights into evolution and speciation in the red alga Bostrychia: 15 years of research

  • Zuccarello, Giuseppe C.;West, John A.
    • ALGAE
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    • 제26권1호
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    • pp.21-32
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    • 2011
  • Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

Aerodynamic performance evaluation of different cable-stayed bridges with composite decks

  • Zhou, Rui;Ge, Yaojun;Yang, Yongxin;Du, Yanliang;Zhang, Lihai
    • Steel and Composite Structures
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    • 제34권5호
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    • pp.699-713
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    • 2020
  • The aerodynamic performance of long-span cable-stayed bridges is much dependent on its geometrical configuration and countermeasure strategies. In present study, the aerodynamic performance of three composite cable-stayed bridges with different tower configurations and passive aerodynamic countermeasure strategies is systematically investigated by conducting a series of wind tunnel tests in conjunction with theoretical analysis. The structural characteristics of three composite bridges were firstly introduced, and then their stationary aerodynamic performance and wind-vibration performance (i.e., flutter performance, VIV performance and buffeting responses) were analyzed, respectively. The results show that the bridge with three symmetric towers (i.e., Bridge I) has the lowest natural frequencies among the three bridges, while the bridge with two symmetric towers (i.e., Bridge II) has the highest natural frequencies. Furthermore, the Bridge II has better stationary aerodynamic performance compared to two other bridges due to its relatively large drag force and lift moment coefficients, and the improvement in stationary aerodynamic performance resulting from the application of different countermeasures is limited. In contrast, it demonstrates that the application of both downward vertical central stabilizers (UDVCS) and horizontal guide plates (HGP) could potentially significantly improve the flutter and vortex-induced vibration (VIV) performance of the bridge with two asymmetric towers (i.e., Bridge III), while the combination of vertical interquartile stabilizers (VIS) and airflow-depressing boards (ADB) has the capacity of improving the VIV performance of Bridge II.

Dietary Frequencies of Korean American Adolescents in California: Correlation of Acculturation and Parental Dietary Consumption

  • Song YoonJu;Paik Hee Young;Park Haeryun;Hofstetter C. Richard;Hovell Melbourne F.;Irvin Veronica;Lee Jooeun
    • Nutritional Sciences
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    • 제8권2호
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    • pp.104-110
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    • 2005
  • The purpose of this study was to examine dietary frequencies among Korean American adolescents in California, including the correlation of acculturation and parental dietary Consumption. This study was drawn from cross-sectional telephone surveys based on data from a larger study of Korean Americans in California using random sampling of residential phone listings. A total of 494 Korean American adolescents, ages 12 through 17, in California were collected with dietary frequencies and acculturation and one parents' demographic and dietary consumption information. Three-quarters of adolescents were classified as 'more acculturated group' into the U.S. society with a lower preference to Korean foods, frequent snacking, and lower consumptions of rice and kimchi. Other quarter of adolescents was classified as 'less acculturated group'. However, the most frequent food items by both groups were rice and kimchi. Fruit and vegetable consumption was associated between adolescents and parents in both groups, but rice and kimchi were associated only among the more-acculturated group. In conclusion, dietary frequencies of Korean American adolescents were influenced by acculturation and parental dietary consumption. These findings should inform future epidemiological researches as well as efforts to enhance the diet of Koreans and other immigrants.

Practical countermeasures for the aerodynamic performance of long-span cable-stayed bridges with open decks

  • Zhou, Rui;Yang, Yongxin;Ge, Yaojun;Mendis, Priyan;Mohotti, Damith
    • Wind and Structures
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    • 제21권2호
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    • pp.223-239
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    • 2015
  • Open decks are a widely used deck configuration in long-span cable-stayed bridges; however, incorporating aerodynamic countermeasures are advisable to achieve better aerodynamic performance than a bluff body deck alone. A sectional model of an open deck cable-stayed bridge with a main span of 400 m was selected to conduct a series of wind tunnel tests. The influences of five practical aerodynamic countermeasures on flutter and vortex-induced vibration (VIV) performance were investigated and are presented in this paper. The results show that an aerodynamic shape selection procedure can be used to evaluate the flutter stability of decks with respect to different terrain types and structural parameters. In addition, the VIV performance of $\prod$-shaped girders for driving comfortableness and safety requirements were evaluated. Among these aerodynamic countermeasures, apron boards and wind fairings can improve the aerodynamic performance to some extent, while horizontal guide plates with 5% of the total deck width show a significant influence on the flutter stability and VIV. A wind fairing with an angle of $55^{\circ}C$ showed the best overall control effect but led to more lock-in regions of VIV. The combination of vertical stabilisers and airflow-depressing boards was found to be superior to other countermeasures and effectively boosted aerodynamic performance; specifically, vertical stabilisers significantly contribute to improving flutter stability and suppressing vertical VIV, while airflow-depressing boards are helpful in reducing torsional VIV.

Thorea indica sp. nov. (Thoreales, Rhodophyta) from Uttar Pradesh, India

  • Necchi, Orlando Jr;Paiano, Monica O.;West, John A.;Ganesan, E. K.;Goer, Susan Loiseaux-de
    • ALGAE
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    • 제30권4호
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    • pp.265-274
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    • 2015
  • Thorea indica sp. nov. is described from the Sai River, Uttar Pradesh, India (26°39′00.7″ N, 80°47′38.3″ E). Its classification is based on molecular sequences of the plastid-encoded RuBisCO large-subunit gene, rbcL and the barcode region of the mitochondrial encoded cytochrome c oxidase subunit 1, cox1, and morphological data. The sequence analyses confirm a new species of Thorea. The cox1 barcode sequence had 90.4-90.8% identity with Thorea sp. from Australia and Thorea hispida from Hawaii and China. Based on rbcL sequences the Indian specimen was positioned in a major clade with high support (>95 bootstrap and 0.95 posterior probability) containing two other species: T. okadae from Japan and T. hispida from the continental USA, Hawaii, the UK, and China. The divergences among these sequences were T. indica vs. T. okadae (2.8%) and T. indica vs. T. hispida (2.9-3.4%). The comparison of morphological characters of Thorea from India was not conclusive due to the inadequate descriptions in previous reports: most specimens reported as T. hispida fit within the circumscription of T. indica as described here. The previous report of T. siamensis from the Sai River is incorrect and the specimens fit within our description of T. indica. Thorea indica and T. okadae can be distinguished by minor morphometric characters and sexuality (dioecious vs. monoecious).

Lemanea manipurensis sp. nov. (Batrachospermales), a freshwater red algal species from North-East India

  • Ganesan, E.K.;West, J.A.;Zuccarello, G.C.;de Goer, S. Loiseaux;Rout, J.
    • ALGAE
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    • 제30권1호
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    • pp.1-13
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    • 2015
  • A new macroscopic riverine red algal species, Lemanea manipurensis sp. nov. (Batrachospermales) is described from Manipur in northeast India. It has a sparsely branched, pseudoparenchymatous thallus with a single, central axial filament that lacks cortical filaments. Spermatangia occur generally in isolated, low and indistinct patches or form an almost continuous ring around the axis. Carposporophytes project into the hollow thallus cavity without an ostiole. The most striking morphological feature is the carposporophyte with very short gonimoblast filaments having cylindrical, narrow and sparsely branched sterile filaments, the terminal cell of each branch with a single, large, elongate carpospore. The widely distributed L. fluviatilis has spherical carpospores in long branched chains. Phylogenetic analysis of rbcL sequence data and comparison with other Batrachospermales clearly show that our specimens do not align with other species of Lemanea and Paralemanea investigated thus far. Five specific names attributed in previous literature (1973-2014) to Lemanea from Manipur, L. australis, L. catenata, L. fluviatilis, L. mamillosa, and L. torulosa are rejected until critical anatomical and molecular evidence is available for specimens from the Manipur river systems. Taxa referable to Paralemanea were not confirmed for India in this study. In view of the high demand for food and medical uses of L. manipurensis in northeast India, conservation measures are needed for its long term survival. The present paper constitutes the first combined morphological / molecular study on a freshwater red alga from India.

국외 의과대학의 문제바탕학습 (Problem-Based Learning) (Problem-Based Learning in medical schools worldwide)

  • 신홍임
    • 의학교육논단
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    • 제10권1호
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    • pp.35-42
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    • 2008
  • Purpose : Since PBL was first developed by Howard Barrows at McMaster, it has been adopted as one of the best teaching and learning methods in medical schools throughout the world. However, the educational superiority of PBL relative to traditional approaches is less clear. Given the somewhat extensive resources required for the operation of PBL curriculum, this gives reason for concern. The aim of this study is to review experiences of PBL in other medical schools and learn how to implement PBL in our school. Methods : This study was undertaken in two stages. In the first stage, PBL curricular examples in 7 medical schools (University of Pennsylvania, University of Melbourne, University of Maastricht, McMaster University, Flinders University, Harvard medical school. University of California at L.A.) were collected and summarized. In the second stage, a careful search for articles of journals published since 2000 regarding PBL group assessment, effectiveness of PBL and group facilitation skills was conducted. Results : PBL is generally introduced in a core curriculum in undergraduate medical education. Relating to small group assessment, the perception of students has been well developed. but the current PBL assessment tool needs to be revised, to develop thinking skills of students. The PBL graduates considered themselves as having much better interpersonal skills, better competencies in problem solving and self-directed learning than the non-PBL graduates. Tutors used various techniques to raise awareness, facilitate the group process and direct learning. Conclusions : The following three aspects can be regarded as important in this study. First, to implement PBL in our school more effectively, it might be considered, which curriculum content can be best learned with PBL. Second, to enhance students' thinking skills during PBL, a new assessment tool needs to be developed. Third, tutors' competencies are important to facilitate, group process, so it would be worthwhile including in staff development.

Analysis of Hereditary Nonpolyposis Colorectal Cancer in Malay Cohorts using Immunohistochemical Screening

  • Juhari, Wan Khairunnisa Wan;Rahman, Wan Faiziah Wan Abdul;Sidek, Ahmad Shanwani Mohd;Hassan, Muhammad Radzi Abu;Noordin, Khairul Bariah Ahmad Amin;Zakaria, Andee Dzulkarnaen;Macrae, Finlay;Zilfalil, Bin Alwi
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권9호
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    • pp.3767-3771
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    • 2015
  • Background: Lynch syndrome (LS) is an inherited predisposition to colorectal, endometrial (uterine) and other cancers. Although most cancers are not inherited, about 5 percent (%) of people who have colorectal or endometrial cancer have the Lynch syndrome. It involves the alteration of mismatch repair (MMR) genes; MLH1, MSH2, MSH6 or PMS2. In this study, we analyzed the expression of MMR proteins in colorectal cancer in a Malay cohort by immunohistochemistry. Materials and Methods: A total of 17 patients were selected fulfilling one of the Bethesda criteria: colorectal cancer diagnosed in a patient aged less than 50 years old, having synchronous and metachronous colorectal cancer or with a strong family history. Immunohistochemical staining was performed on paraffin embedded tumour tissue samples using four antibodies: MLH1, MSH2, MSH6 and PMS2. Results: Twelve out of 17 patients (70.6%) were noted to have a family history. A total of 41% (n=7) of the patients had abnormal immunohistochemical staining with one or more of the four antibodies. Loss of expression were noted in 13 tumour tissues with a negative staining score <4. Of 13 tumour tissues, four showed loss expression of MLH1. For PMS2, loss of expression were noted in five cases. Both MSH2 and MSH6 showed loss of expression in two tumour tissues respectively. Conclusions: Revised Bethesda criteria and immunohistochemical analysis constituted a convenient approach and is recommended to be a first-line screening for Lynch syndrome in Malay cohorts.

Insomnia in Cancer - Associations and Implications

  • George, Mathew;Elias, Alby;Shafiei, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권15호
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    • pp.6711-6714
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    • 2015
  • Background: Insomnia is a common condition in cancer patients. In spite of the high prevalence its associations have not been well studied. Existing data suggests that insomnia is related to depression and pain. However, the impact of ongoing chemotherapy on sleep is not investigated. Aim: To study the relationship between insomnia and chemotherapy after analysing confounding variables. Materials and Methods: Consecutive patients who visited New England Oncology Clinic in Tamworth were recruited. Insomnia was assessed with the Bergen insomnia scale. The Montgomery Asberg Depression rating scale was used to measure depression. Pain was assessed with the Brief Pain inventory. Chronic medical conditions, type of cancer, side effects to chemotherapy, role of steroids and other drugs were studied as confounders. Results: A total of 56 patients participated in the study. Age ranged from 33 to 83 years (mean: 63.6, SD=10.97). There were 29 men and 27 women. 42 patients received at least one form of chemotherapy and 15 were receiving radiotherapy at the time of assessment. Mean insomnia score was significantly higher in those receiving chemotherapy than in those without chemotherapy (8.92 vs 17.2, two tailed p=0.005, 95% CI=2.63-13.71). There was no significant variation in insomnia scores in terms of chronic medical condition, type of cancer, psychiatric history, use of steroids or adverse effects of chemotherapy. However, total insomnia score was correlated with depression rating score (Pearson correlation, r=0.39, p=0.003) and magnitude of pain (r=0.37, p=0.006). On regression analysis only pain was found to be predictive of insomnia. Conclusions: Insomnia in patients with cancer is found to be associated with concurrent chemotherapy and correlated with degree of depression and pain. Identifying factors related to insomnia in cancer population has implications in its management and patient education.

Soft-tissue Sarcomas in the Asia-Pacific Region: A Systematic Review

  • Ngan, Roger;Wang, Edward;Porter, David;Desai, Jayesh;Prayogo, Nugroho;Devi, Beena;Quek, Richard
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6821-6832
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    • 2013
  • Background: Soft-tissue sarcomas require tailored and multidisciplinary treatment and management. However, little is known about how sarcomas are treated and managed throughout the Asia-Pacific region. Materials and Methods: MEDLINE was systematically searched using prespecified criteria. Publications (previous 10 years) that reported tumour characteristics, treatment patterns, survival outcomes, and/or safety outcomes of patients with soft-tissue sarcoma were selected. Exclusion criteria were studies of patients <18 years of age; ${\leq}10$ patients; countries other than Australia, Hong Kong, Indonesia, Korea, Malaysia, New Zealand, Philippines, Singapore, Taiwan, or Thailand; >20% benign tumours; sarcomas located in bones or joints; gastrointestinal stromal tumour; Kaposi's sarcoma; or not reporting relevant outcomes. Results: Of the 1,822 publications retrieved, 35 (32 studies) were included. Nearly all patients (98%, 1,992/2,024; 31 studies) were treated with surgery, and more studies used adjuvant radiotherapy than chemotherapy (24 vs 17 studies). Survival outcomes and recurrence rates varied among the studies because of the different histotypes, sites, and disease stages assessed. Only 5 studies reported safety findings. Conclusions: These findings highlight the lack of specific data available about soft-tissue sarcomas in the Asia-Pacific region. Better efforts to understand how the sarcoma is managed and treated will help improve patient outcomes in the region.