1,720,955 research outputs found
Feeding preference of the Formosan Mountain Field Vole (Microtus kikuchii) on Yushan Cane (Yushania niitakayamensis) in Hehuan Alpine Meadows
No full textEffects of Taiwan Vole (Microtus kikuchii) Herbivory on Yushan cane (Yushania niitakayamensis) Growth in Hehuan Alpine Meadows
No full text草食動物雖常被認為對植物的更新、生長、存活有負向的影響，但可能也有正向的影響。草食動物在攝取植物不同部位時，會對植物的適存度有不同影響。在合歡山草原地區，主要的優勢植種為玉山箭竹(Yushania niitakayamensis)，主要的優勢小型哺乳動物為台灣高山田鼠(Microtus kikuchii)， 過去的研究顯示玉山箭竹為高山田鼠主要偏好的植種。本研究希望了解高山田鼠與玉山箭竹之間的關係，因此進行檢驗了以下的假說：(1)台灣高山田鼠對於玉山箭竹的不同部位有取食偏好差異；(2)取食偏好與不同部位的營養成份相關，高偏好的部位含有較高的蛋白質及較低的纖維；(3)台灣高山田鼠對玉山箭竹的取食會增加箭竹冠層光的穿透量及地面掉落物，進而對玉山箭竹的生長有正向的影響。本研究分為實驗室內的取食偏好實驗和箭竹營養成分分析實驗，以及使用野外圍欄移除田鼠實驗和操弄覆蓋度、掉落物實驗兩大部分。實驗結果顯示，高山田鼠對於玉山箭竹各部位有顯著的取食偏好差異，且具有季節上的差異，五月時的取食偏好等級為筍>葉>地下莖=地上莖，在一月及十月時的取食偏好等級為葉>筍=地下莖=地上莖。高山田鼠對各部位的取食偏好與箭竹的酸洗纖維、粗蛋白質及灰份等營養成分含量顯著相關。高山田鼠的啃食活動會降低箭竹覆蓋度及增加掉落物，進行野外降低箭竹覆蓋度及移除掉落物的實驗顯示兩者對箭竹發筍均有顯著的影響。而圍欄實驗的結果亦顯示，移除田鼠會降低圍欄內箭竹筍與莖的比例。因此可得知台灣高山田鼠雖然取食玉山箭竹，但對箭竹的生長具有正向的影響。Although herbivores are often considered having negatively influence on the recruitment, growth, and survival rate of plants, they could benefit plants as well. The herbivorous consumption of different plant parts could have differential effect on fitness of the consumed plants. Yushan canes (Yushania niitakayamensis) is the dominant plant species, and Taiwan vole (Microtus kikuchii) is the dominant small mammal in alpine meadows at the Hehuan Mt.. The former species is the primary and preferred food of the latter species. In this thesis, investigation was set up to elucidate the relationship between the two species. Hypothesis of the study are (1) Taiwan voles have feeding preference on different parts of Yushan canes; (2) feeding preference can be explained by nutrient contents of different parts: highly preferred parts have higher protein and lower fiber contents than less preferred parts; (3) consumption by Taiwan voles has positive effects on the growth of Yushan canes by increasing light penetration into the canopy and aboveground litter. Feeding preference experiments and nutrient content analyses were performed in the laboratory, and field exclosures and field manipulation of canopy and litter were used to test the hypotheses. The results indicated that the ranks of feeding preference by Taiwan voles were shoot > leaf > culm = rhizome in May, and leaf > shoot = culm = rhizome in January and October. The preference was explained by nutrient contents, particularly the amounts of acid detergent fiber (ADF), crude protein (CP), and ash of Yushan cane parts. The exclusion of voles led to decreased shoot-culm ratios. Both the reduction of canopy cover and litter removal had significant effects on the emergence of new shoots after 1 year of field manipulation, indicating that Taiwan voles could facilitate shoot emergence of Yushan canes through increasing light availability and ground litter. I conclude that although Taiwan voles consume Yushan canes, they could benefit Yushan canes as well
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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