1,720,957 research outputs found
PARTICLE SIZE AND TEMPERATURE EFFECTS ON ANTIOXIDANT BY-PRODUCT ISOLATED FROM LEAF GUM EXTRACT OF MESONA PROCUMBENS HEMSL
No full textA water extraction procedure for isolating antioxidants from dried aerial tissue of Mesona procumbens Hemsl. prior to leaf gum/starch composite gel preparation was developed, along with investigation of its antioxidative activities. The results showed that the highest contents of total phenolics and flavonoids were isolated from the dried aerial tissues when they were extracted under 100C for 2 h using the dried materials ground to 75-µm particle size. This water extract also had the highest antioxidative responses, as determined by 2,2-diphenyl-1-picrylhydrazy scavenging, ferric reducing antioxidant power, 2,2-azino-bis[3-ethyl-benzthiazoline-6-sulfonic acid] radical-scavenging, superoxide-scavenging and lipid peroxidation inhibition activities. The water extract produced under 100C condition also showed the greatest gel hardness and gel strength (prepared by using 2% cassava starch). Thus, the extracted antioxidants from aerial tissues of M. procumbens Hemsl. could be considered for some commercial applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
(54(3):195-206)Study on Morphological and Molecular Markers of Yam (Dioscorea spp.)1 Germplasm
No full text三十二個山藥參試品種（系）屬於8個物種及1個變種，包括Dioscorea alata L.（17個）、D. alata L. var. purpurea（3個）、D. batatas（5個）、D. pseudojaponica（2個）、D. doryphora（1個），D. escunlenta（1個）、D. bulbifera（1個）、D. rotundata（1個）及D. persimilis（1個）進行外表形態調查及RAPD分子性狀分析，以探討物種間及物種內之變異。取其葉片DNA進行RAPD分析，在40個逢機引子對中，有12個引子對可穩定擴增出43個多型性片段，進一步進行群組分析時可明確分成七群，與物種歸屬符合，其中以D. alata為最大群，種內可分為五小群，分別為塊狀薯群、罐形薯群、紅皮白肉山藥群、紅肉山藥群、長薯山藥群，而優良品系大汕二號與台農2號明顯不同。儘管同一群內品種（系）分子鑑定仍有困難，但外表形態分群結果與RAPD分析分群相呼應，表示可依種群進行特色開發，進行群內品系選育，以達到多樣化育種目的，可讓消費者有更明確的選擇。Thirty-two yam lines of nine species, including Dioscorea alata L. (17 lines), D. alata L. var. purpurea (3 lines), D. batatas (5 lines), D. pseudojaponica (2 lines), D. doryphora (1 line), D. escunlenta (1 line), D. bulbifera (1 line), D. rotundata (1 line) and D. persimilis (1 line) were used in this study. Variation among and within yam species was investigated via morphological and RAPD analysis. Forty random primers were carried out in RAPD analysis. Forty-three polymorphic bands generated by twelve primers were used in cluster analysis. The result reveals seven clusters consistent with classification yam species. D. alata species is the largest cluster, and can be further divided into five sub-clusters. The first sub-cluster is clumpy yam. The second sub-cluster is bottle-shape yam. The third sub-cluster is white flesh with red skin yam. The forth sub-cluster is red flesh yam. Another one is long tuber length yam. Although it is still difficult to identify specific line within the same cluster, such a RAPD analysis corresponds with morphological analysis reveals that it is possible to proceed breeding cluster by cluster
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
(60(2):101-114)Extraction of Imperatorin from Root Slices and Explants of Angelica dahurica
No full text白芷為國人延用已久的傳統藥材，其被廣泛地應用於治療一些症狀，像是鼻炎、鼻息肉以及皮膚病。白芷所含的有效成分主要是呋喃香豆素衍生物，包含有歐前胡素、白當歸素以及白芷素等，由於少有運用組織培養誘導產生白芷微塊莖和綠色癒傷組織等培植體的資料，因此，本研究目的乃探討萃取培植體中歐前胡素的方法。結果顯示，白芷癒傷組織繼代培養於含WPM基本竅類並添加30 g.L-1蔗糖和8.5 g.L-1洋菜粉的固體培養基中30天後之鮮重最高（25.0 g/瓶），其次依序為接種在B-5 (18.6g瓶）、1/2MS (9.7g瓶）和MS (5.1g/瓶）基本鹽類培養基。將白色癒傷組織繼代培養於WB1N0.5培養基90天後，誘導綠色癒傷組織生成的比率達到60.0％在三種不同的溶劑（甲醇、去離子水和乙醇）中，甲醇是最適當的溶劑，其可由每1g的市售白芷根飲片乾燥樣品萃取到772.3μg的歐前胡素。白芷白色癒傷組織以WPM培養基繼代培養3個月後，其歐前胡素之含量為32.0計，但培育3個月的白芷微塊莖歐前胡素含量則可達到83.3μg.g-1。本研究顯示能利用白芷微塊莖大量生產歐前胡素及大量繁殖苗株的可行性。
Angelica dahurica has long been a popular plant for traditional medicine by Chinese people. It is widely used to treat disorders, such as catarrh, nasal polypus and skin affections. The main active ingredients of A. dahurica are furo-coumarin derivatives, including imperatorin, angelical, and byak-angelicin. Information is scarce on extraction of imperatorin from microtubers and green callus of A. dahurica plants grown in tissue culture. The objective of this study was to investigate methods of extraction for imperatorin produced in explants of A. dahurica. Results showed that the fresh weight of callus of A. dahurica was the highest (25.0 g/flask) in 30-day-old cultures on the medium containing WPM basal salts supplemented with 30 g.L-1 sucrose and 8.5 g.L-1 agar, followed by cultures on B-5 basal salt medium (18.6 g/flask), 1/2 MS medium (9.7 g/flask) and MS medium (5.1 g/flask). The rate of formation of green callus was 60% after white callus of A. dahurica subcultured on WB1N0.5 medium for 90 days. Among the three solvents (methanol, water and ethanol) investigated, methanol was the best solvent for extraction of imperatorin from commercial root slices of A. dahurica which yielded 772.3 μg of imperatorin in each gram of dry sampling. Imperatorin in white callus from 3-month-old cultures on WPM medium was 32.0 μg.g-1, whereas imperatorin in microtubers from 3-month-old cultures was 83.3μg.g-1. This study suggests that it is possible for mass-production of imperatorin and mass-propagation of plantlets using microubers of A. dahurica
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