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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Effects Of Extreme Climate Events On Tea (Camellia Sinensis) Functional Quality Validate Indigenous Farmer Knowledge And Sensory Preferences In Tropical China, Selena Ahmed, John Richard Stepp, Colin M. Orians, Timothy S. Griffin, Corene Matyas, Albert Robbat, Sean Cash, Dayuan Xue, Chunlin Long, Uchenna Unachukwu, Sarabeth Buckley, Edward J. Kennelly Oct 2014

Effects Of Extreme Climate Events On Tea (Camellia Sinensis) Functional Quality Validate Indigenous Farmer Knowledge And Sensory Preferences In Tropical China, Selena Ahmed, John Richard Stepp, Colin M. Orians, Timothy S. Griffin, Corene Matyas, Albert Robbat, Sean Cash, Dayuan Xue, Chunlin Long, Uchenna Unachukwu, Sarabeth Buckley, Edward J. Kennelly

Publications and Research

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world’s most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in …


Component Trees For The Exploration Of Macromolecular Structures In Biology, Lucas Oliveira Oct 2014

Component Trees For The Exploration Of Macromolecular Structures In Biology, Lucas Oliveira

Dissertations, Theses, and Capstone Projects

Understanding the three-dimensional structure of a macromolecular complex is essential for understanding its function. A component tree is a topological and geometric image descriptor that captures information regarding the structure of an image based on the connected components determined by different grayness thresholds. This dissertation presents a novel interactive framework for visual exploration of component trees of the density maps of macromolecular complexes, with the purpose of improved understanding of their structure. The interactive exploration of component trees together with a robust simplification methodology provide new insights in the study of macromolecular structures. An underlying mathematical theory is introduced and …


Variation In Habitat Thresholds: An Analysis Of Minimum Habitat Requirements Of North American Breeding Birds, Yntze Van Der Hoek Jun 2014

Variation In Habitat Thresholds: An Analysis Of Minimum Habitat Requirements Of North American Breeding Birds, Yntze Van Der Hoek

Dissertations, Theses, and Capstone Projects

Many species show dramatic changes in population extinction or persistence probability at particular habitat amounts. These `extinction thresholds' could be translated to conservation targets, under the condition that we can derive generalities. I investigated the level of variation in landscape-level habitat thresholds for a suite of North American, forest-associated, breeding birds. Records from Breeding Bird Atlases and the availability of remotely-sensed land cover data allowed me to compare habitat thresholds for 25 species across the states of Massachusetts, Michigan, New York, Ohio, Pennsylvania, and Vermont. I show that variation in thresholds is considerable (Chapter II, III), as thresholds range from …


An Experimental Investigation Into The Mechanisms Of Bacterial Evolution, Zhenmao Wan Feb 2014

An Experimental Investigation Into The Mechanisms Of Bacterial Evolution, Zhenmao Wan

Dissertations, Theses, and Capstone Projects

This thesis studies the two fundamental mechanisms of bacterial evolution — horizontal gene transfer and spontaneous mutation, in the bacterium Escherichia coli through novel experimental assays and mathematical simulations. First, I will develop a growth assay utilizing the quantitative polymerase chain reaction (qPCR) to provide real-time enumeration of genetic marker abundance within bacterial populations. Second, I will focus on horizontal gene transfer in E. coli occurring through a process called conjugation. By fitting the qPCR data to a resource limited, logistic growth model, I will obtain estimated values of several key parameters governing the dynamics of DNA transfer through conjugation …