4 pp. / Leaf analysis is an excellent tool for determining the nutritional status of pecan trees.

Revised; Originally Published: 2006 / 3 pp.

Given a graph G, we construct T(G), called the tree graph of G. The vertices of T(G) are the spanning trees of G, with edges between vertices when their respective spanning trees differ only by a single edge. In this paper we detail many new results concerning tree graphs, involving topics such as clique decomposition, planarity, and automorphism groups. We also investigate and present a number of new results on orthogonal tree decompositions of complete graphs.

Allergic diseases affect a substantial proportion of people living in urban areas in the United States in general and in New York City (NYC) specifically. Many types of pollen are considered to be allergens, and have been linked to several manifestations of allergic disease, including allergic sensitization, exacerbation of allergic rhinitis, and exacerbation of allergic asthma. However, the role of pollen in determining temporal patterns of allergic disease is incompletely understood, and virtually nothing is known about the spatial distribution of pollen within cities and the relevance of this distribution to health. A better understanding of these relationships is especially critical as massive urban tree planting projects progress, and as the length and severity of the annual pollen season changes in response to changing temperature and carbon dioxide concentrations. The overall objective of this dissertation was to measure the spatial and temporal patterns of tree pollen in NYC and examine their associations with several allergic disease outcomes. Chapter 1 evaluates the health effects of the temporal distribution of pollen by examining the relationship between daily concentrations of several types of tree pollen measured in Armonk, NY with emergency department (ED) visits for asthma in NYC. We found that daily concentrations of four allergenic tree pollen genera were associated with a significantly increased rate of ED visits for asthma citywide. We further found that these associations were stronger in zip codes with higher tree canopy cover, suggesting that there may be spatial heterogeneity in tree pollen exposure within NYC not captured by the daily monitoring station. Chapter 2 tests the hypothesis that there is spatial variability in tree pollen within NYC by developing a novel dataset of spatial pollen measurements for the 2013 pollen season from 45 sites across NYC. These sites were co-located with an established network of air pollutant monitoring sites. Results from the 2013 monitoring campaign demonstrated substantial variability in tree pollen levels across the city. Total tree pollen deposition ranged from 2,942 grains per cm² to 17,460 grains per cm², a factor of almost six. Some individual tree pollen taxa exhibited an even greater degree of variation. We also developed a land use regression model for total tree pollen and tested the hypothesis that tree pollen influx at these sites is associated with tree canopy cover. When included alone in the model, percent tree canopy cover within a 0.5 km radial buffer of the monitoring sites explained 39% of the variance in tree pollen, while the inclusion of additional land use variables did not improve model fit. In Chapter 3, we use the land use regression model to develop tree pollen exposure estimates for children enrolled in the NYC Neighborhood Allergy and Asthma Study and evaluated whether modeled tree pollen influx for the first year of life is associated with allergic sensitization to tree pollen by age 7-8. We found that a standard deviation increase in tree pollen exposure in the first year of life was associated with a 50% increase in the prevalence of allergic sensitization to tree pollen. Furthermore, this association was stronger among children in the top 50% of black carbon exposure, suggesting that exposure to traffic-related pollutants may facilitate allergic sensitization.

呂鍵培. / "2004年4月". / 論文(哲學碩士)--香港中文大學, 2004. / 參考文獻 (p. 122-130). / 附中英文摘要. / "2004 nian 4 yue". / LüJianpei. / Lun wen (zhe xue shuo shi)--Xianggang Zhong wen da xue, 2004. / Can kao wen xian (p. 122-130). / Fu Zhong Ying wen zhai yao. / 撮要 --- p.i / 鳴謝 --- p.iii / 目錄 --- p.iv / 表目錄 --- p.ix / 圖目錄 --- p.xi / 程式目錄 --- p.xiii / 相片目錄 --- p.xiv / Chapter 章節一 --- 引言 / Chapter 1.1 --- 背景 --- p.1 / Chapter 1.2 --- 理論架構 --- p.3 / Chapter 1-3 --- 目標 --- p.3 / Chapter 1.4 --- 重要性 --- p.4 / Chapter 1.5 --- 論文槪述 --- p.4 / Chapter 章節二 / Chapter 2.1 --- 引言 --- p.5 / Chapter 2.2 --- 樹木與年輪成長發展 --- p.5 / Chapter 2.3 --- 年輪定年學基礎原則 --- p.9 / Chapter 2.4 --- 年輪氣象學應用 --- p.12 / Chapter 2.4.1 --- 年輪氣象學的季風硏究 --- p.13 / Chapter 2.5 --- 中國年輪硏究 --- p.15 / Chapter 2.6 --- 年輪研究在自然地理的應用 --- p.16 / Chapter 2.7 --- 總結 --- p.17 / Chapter 章節三 --- 硏究方法 / Chapter 3.1 --- 硏究槪況 --- p.19 / Chapter 3.1.1 --- 香港槪述 --- p.19 / Chapter 3.1.2 --- 品種和採樣地點測試 --- p.21 / Chapter 3.1.3 --- 大菴之木荷 --- p.23 / Chapter 3.1.4 --- 荔枝窩之樟樹 --- p.26 / Chapter 3.1.5 --- 植物品種的異同 --- p.28 / Chapter 3.2 --- 野外技術 --- p.29 / Chapter 3.2.1 --- 樣本之選擇 --- p.29 / Chapter 3.2.2 --- 樣本採集和記錄 --- p.30 / Chapter 3.3 --- 實驗室技術 --- p.31 / Chapter 3.3.1 --- 樣本處理 --- p.31 / Chapter 3.3.2 --- Lintab系統和年輪測量 --- p.31 / Chapter 3.3.3 --- 交叉定年 --- p.32 / Chapter 3.3.4 --- 生長率校準 --- p.33 / Chapter 3.3.5 --- 異常數據（Outlier) --- p.34 / Chapter 3.3.6 --- 標準化 --- p.34 / Chapter 3.3.7 --- 主年表之建立 --- p.36 / Chapter 3.3.7.1 --- 平均敏感度(Mean sensitivity) --- p.36 / Chapter 3.3.7.2 --- 平均相關系數（Mean of correlation coefficient) --- p.36 / Chapter 3.3.7.3 --- 信噪比（Signal to noise ratio) --- p.37 / Chapter 3.3.7.4 --- 其他統計數値 --- p.37 / Chapter 3.4 --- 環境資料 --- p.38 / Chapter 3.5 --- 統計分析方法 --- p.39 / Chapter 章節四 --- 年輪的特徵和主年表的建立 / Chapter 4.1 --- 引言 --- p.40 / Chapter 4.2 --- 鑽芯 --- p.40 / Chapter 4.3 --- 年輪特徵 --- p.41 / Chapter 4.3.1 --- 樹木鑽芯 --- p.41 / Chapter 4.3.2 --- 年輪種類 --- p.42 / Chapter 4.4 --- 交叉定年及年輪異常 --- p.43 / Chapter 4.5 --- 主年表 --- p.48 / Chapter 4.5.1 --- 木荷主年表 --- p.48 / Chapter 4.5.2 --- 樟樹主年表 --- p.53 / Chapter 4.6 --- 討論 --- p.58 / Chapter 4.7 --- 總結 --- p.59 / Chapter 章節五 --- 年輪與環境因子的關係 / Chapter 5.1 --- 引言 --- p.60 / Chapter 5.2 --- 水份供應 --- p.60 / Chapter 5.3 --- 溫度 --- p.61 / Chapter 5.4 --- 濕潤指數 --- p.61 / Chapter 5.5 --- 年表 --- p.62 / Chapter 5.6 --- 雨量因子 --- p.62 / Chapter 5.6.1 --- 全年降雨量 --- p.62 / Chapter 5.6.2 --- 季雨(或月份雨量） --- p.66 / Chapter 5.7 --- 溫度因子 --- p.67 / Chapter 5.7.1 --- 全年平均溫度和其他溫度因子 --- p.67 / Chapter 5.7.2 --- 月份和季節平均溫度 --- p.69 / Chapter 5.8 --- 偏相關分析 --- p.70 / Chapter 5.8.1 --- 全年降雨量 --- p.70 / Chapter 5.8.2 --- 季雨(或月份雨量） --- p.70 / Chapter 5.8.3 --- 全年和月份平均溫度 --- p.71 / Chapter 5.9 --- 多元回歸分析 --- p.72 / Chapter 5.9.1 --- 全年降雨量 --- p.72 / Chapter 5.9.2 --- 季雨(或月份雨量） --- p.75 / Chapter 5.9.3 --- 月份和季節平均溫度 --- p.76 / Chapter 5.10 --- 討論 --- p.77 / Chapter 5.10.1 --- 雨量 --- p.77 / Chapter 5.10.2 --- 溫度 --- p.78 / Chapter 5.11 --- 滑動平均分析 --- p.80 / Chapter 5.11.1 --- 相關分析 --- p.80 / Chapter 5.11.2 --- 偏相關分析 --- p.80 / Chapter 5.11.3 --- 回歸分析 --- p.82 / Chapter 5.11.4 --- 討論 --- p.84 / Chapter 5.12 --- 濕潤指數 --- p.85 / Chapter 5.13 --- 濕年與乾年的反應 --- p.85 / Chapter 5.13.1 --- 木荷年表 --- p.85 / Chapter 5.13.2 --- 樟樹年表 --- p.87 / Chapter 5.14 --- 年輪波動與雨水供應討論 --- p.88 / Chapter 5.15 --- 坡向影響 --- p.88 / Chapter 5.16 --- 年齢影響 --- p.92 / Chapter 5.17 --- 土壤影響 --- p.92 / Chapter 5.18 --- 植物對環境反應的相同處 --- p.94 / Chapter 5.19 --- 植物對環境反應的不同之處 ̐ơ / Chapter 5.20 --- 總結 --- p.95 / Chapter 章節六 --- 環境重建模式 / Chapter 6.1 --- 引言 --- p.96 / Chapter 6.2 --- 硏究目標 --- p.96 / Chapter 6.3 --- 環境重建因子 --- p.97 / Chapter 6.4 --- 估計氣候數據驗証 --- p.98 / Chapter 6.5 --- 推考環境數據 --- p.109 / Chapter 6.6 --- 討論 --- p.116 / Chapter 6.7 --- 總結 --- p.117 / Chapter 章節七 --- 總結 / Chapter 7.1 --- 引言 --- p.118 / Chapter 7.2 --- 硏究結果摘要 --- p.118 / Chapter 7.2.1 --- 細胞與年輪結構 --- p.118 / Chapter 7.2.2 --- 環境控制因子 --- p.118 / Chapter 7.2.3 --- 環境重建 --- p.119 / Chapter 7.3 --- 硏究限制 --- p.120 / Chapter 7.4 --- 香港年輪硏究的發展方向 --- p.120 / 參考書目 --- p.122 / 附件 --- p.131

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2000. / Thesis based on four papers, which are included. Includes bibliographical references.

No description available.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

After European settlement, Australian rangelands especially in South Australia underwent significant changes because of the main land use of pastoralism. Many studies have revealed that the plant communities are negatively effected by herbivory mainly by sheep. The main aim of this study is to separate the different effects of sheep, rabbits and kangaroos. This was examined by survey supported by experimental and modelling research. / A 32,000 km² area previously surveyed by Tiver and Andrew (1997) in eastern South Australia was re-surveyed to monitor populations of perennial plant species at sites of various intensity of grazing by sheep, rabbits and kangaroos (goats populations are low in the study area), the most important vertebrate herbivores. Plant population data were collected in both sheep paddocks and historically ungrazed by sheep (road reserves) by using the Random Walk method and analysed using Generalized Linear Modelling (GLM) to separate the effects of sheep and rabbits on plant regeneration and their regeneration in response to grazing. These data were also compared to similar data collected by Tiver and Andrew in 1992 (1997) to ascertain if the reduction in rabbit numbers through introduction of RCV had allowed increased regeneration. Regeneration of many species inside paddocks were negatively affected and species in roadside reserves did not significantly increase from 1992 to 2004. However, some species showed increase of populations in spite of sheep grazing, with some species being less susceptible than others. This research also indicates kangaroo grazing impact on some plant species. Reduction in rabbit numbers following the 1995 release of calicivirus has not been effective in restoring regeneration. Another experiment was conducted at Middleback Field Station near Whyalla to identify herbivore grazing pressure on the arid zone plant species Acacia aneura using unfenced, sheep fenced and rabbit fenced grazing exclosures. This experiment was set up with seedlings in exclosures, ten replicates of each treatment, at plots four different distances from the watering point to identify the survivorship of seedlings. Data were collected by recording canopy volumes of seedling over an 18 month period and analysed by Residual Maximal Likelihood (REML). Seedlings both near and far from the watering point were severely affected by large herbivores, either sheep, kangaroos or both, and in a separate experiment kangaroo grazing effects on the seedling were also identified. Seedlings browsed by the rabbits recovered better than the seedlings grazed by the large herbivores. Decreasing kangaroo activities has been noticed when the rabbit movements increased. Computer modelling was conducted to predict the future plant population structure over 500 years using a matrix population model developed by Tiver et al. (2006) and using data collected in the survey as a starting point. Extinction probabilities of populations of Acacia aneura near watering points, far from watering points and under pulse grazing scenarios were compared. Sheep grazing was found to cause eventual extinction of populations in all parts of sheep paddocks. Together, the results indicate that sheep are the major herbivore suppressing regeneration of perennial plant species. Kangaroo and rabbits have an identifiable but lesser effect. The results have implications for conservation and pastoral management. To achieve ecological sustainability of arid lands a land-use system including a network of reserves ungrazed by sheep and with control of both rabbit and kangaroo numbers will be required. / Thesis (PhD)--University of South Australia, 2006.

Thesis (MS)--University of Montana, 2007. / Contents viewed on April 1, 2010 Title from author supplied metadata. Includes bibliographical references.