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No description available.

No description available.

Pecan [Carya illinoinensis (Wangenh.) C. Koch] is a species distributed over an area of varied geographic and climatic variation in the Unites States and Mexico providing a potential for anatomical and physiological adaptation within the cultivars and provenances (i.e., the area of origin of seed). An assessment of leaf anatomical traits of pecan cultivars (Pawnee, Mohawk and Starking Hardy Giant) collected from three locations (Tifton, GA., Chetopa, KS., and Stillwater, OK.) was conducted to provide an understanding of patterns of ecogeographic variation within the natural range. The stomatal density 'Pawnee’ (404 stomata/mm2) was intermediate between that of ‘Mohawk’ (363 stomata/mm2) and ‘Starking Hardy Giant’ (463 stomata/mm2). There were differences among the three pecan cultivars at the same location but there were no differences in stomatal density within the same cultivar grown at three distinct locations. The study suggested that differences in stomatal density in pecans are cultivar-specific rather than being determined by environmental factors. The stability of certain leaf anatomical characteristics, such as stomatal density, for pecan cultivars grown at different locations confirms that these traits can be used for screening provenances with desirable leaf anatomical characteristics for breeding and cultivar development. To achieve the objective of studying anatomical, morphological and physiological traits, Mexican and U.S. provenances grown at the Pecan Genetics and Breeding Program facility in Somerville, Texas were used. The prominent results from the provenance study indicate the presence of intra-specific variation in pecan provenances for the morphological and anatomical traits along the east-west gradient. It is also interesting to note that western provenances displayed the least stomatal density (350 stomata/mm2) while an eastern provenance showed the greatest stomatal density (728 stomata/mm2). This trend may be explained with the gradient in moisture availability from the wetter conditions in the east to the arid conditions in the west in North America. Most of the physiological traits measured did not show any distinct differences between the provenances. There is a great possibility that anatomical traits like stomatal density are genetically controlled to a great extent in pecan in comparison to the physiological traits.

This study investigated the development of knowledge of vocabulary including multiple meanings of words during the school years. Twenty children from each of Grades 2, 5, 8, and 11 were tested for their knowledge of all the meanings of a large random sample of words from an unabridged dictionary (Webster's Third, 1981). Approximately 47% of the words had more than one meaning. Total average estimated vocabulary increased from 17,970 words in Grade 2 to 83,871 words in Grade 11. The estimated number of known derived words increased at the greatest rate throughout the school years. There was evidence that participants may have used morphological problem solving to figure out at least one meaning for 45% of their total vocabulary. Not only did the number of words known increase dramatically through the school years but the total average estimated number of different word meanings known increased also from 28,797 word meanings in Grade 2 to 185,990 word meanings in Grade 11. Three types of meanings were identified according to their relation to their principal meaning (known by the most children): homonyms (share no semantic relationship); conversions (different grammatical part of speech); and metaphorical extensions (share some other semantic relationship). When children demonstrated knowledge of more than one meaning, they were asked to attempt to explain the relation between those two meanings. Even the youngest children in Grade 2 knew a large number of multiple meanings but the ability to express knowledge of a relation between those meanings was uncommon until the later school years. This developing ability can be explained in part by the children’s increasing metalinguistic awareness and general linguistic expressiveness but also by an increasing ability to understand and express metaphorical similarities between lexical concepts, which are common to the metaphorically extended meanings.

Social status is commonly established among individuals within groups of animals. Despite this common characteristic of social animals it is still unclear how individuals establish their status. I investigated the relationships between morphology, posture and behaviours with social status in red junglefowl hens. The hens tested were measured (weight, comb length, comb height and tarsus length) and exposed to three different behavioural tests (novel arena, novel object and interaction test). None of the morphological features were associated with social status. However, dominant hens initiated the first encounter in a dyad interaction and performed a higher proportion of aggressive encounters against the opponent. The dominant hens were also the ones displaying more spread tail feathers than the opponent after status being established. Aggressiveness and social status is strongly linked, showing that there is a scope of behaviours to affect the establishment of status.

Pecan [Carya illinoinensis (Wangenh.) C. Koch] is a species distributed over an area of varied geographic and climatic variation in the Unites States and Mexico providing a potential for anatomical and physiological adaptation within the cultivars and provenances (i.e., the area of origin of seed). An assessment of leaf anatomical traits of pecan cultivars (Pawnee, Mohawk and Starking Hardy Giant) collected from three locations (Tifton, GA., Chetopa, KS., and Stillwater, OK.) was conducted to provide an understanding of patterns of ecogeographic variation within the natural range. The stomatal density 'Pawnee’ (404 stomata/mm2) was intermediate between that of ‘Mohawk’ (363 stomata/mm2) and ‘Starking Hardy Giant’ (463 stomata/mm2). There were differences among the three pecan cultivars at the same location but there were no differences in stomatal density within the same cultivar grown at three distinct locations. The study suggested that differences in stomatal density in pecans are cultivar-specific rather than being determined by environmental factors. The stability of certain leaf anatomical characteristics, such as stomatal density, for pecan cultivars grown at different locations confirms that these traits can be used for screening provenances with desirable leaf anatomical characteristics for breeding and cultivar development. To achieve the objective of studying anatomical, morphological and physiological traits, Mexican and U.S. provenances grown at the Pecan Genetics and Breeding Program facility in Somerville, Texas were used. The prominent results from the provenance study indicate the presence of intra-specific variation in pecan provenances for the morphological and anatomical traits along the east-west gradient. It is also interesting to note that western provenances displayed the least stomatal density (350 stomata/mm2) while an eastern provenance showed the greatest stomatal density (728 stomata/mm2). This trend may be explained with the gradient in moisture availability from the wetter conditions in the east to the arid conditions in the west in North America. Most of the physiological traits measured did not show any distinct differences between the provenances. There is a great possibility that anatomical traits like stomatal density are genetically controlled to a great extent in pecan in comparison to the physiological traits.

Informal settlements are a form of housing found in many parts of the world. Self-help housing in informal settlements has different influences that are denoted in the customs and preferences of the residents, which in turn, are reflected on the elements of house exteriors as well as its interior. Colonias in the U.S-Mexico border region are a model of informal settlements. The purpose of this study is to analyze the social and cultural influences on housing fronts in Webb County Colonias. The study focuses on investigating traditional features, vernacular forms, building rituals, and social features as they relate to the morphology of house fronts and their production. The housing model of Geddes and Bertalanffy explained by Turner (1972) was the premise of establishing the argument of this study. A mixed-method approach was used in data gathering from the following three Colonias: Los Altos, Larga Vista, and Rio Bravo. Utilized methods included image-based research through systematic random sampling of housing fronts in the Colonias, as well as a group-administered structured survey distributed during community monthly gathering for food distribution. The development of the research process and methodology incorporated the input of the local community and local leaders and volunteers assisted in its implementation. The study concluded that past and present experiences of Colonias residents have intense impacts on different aspects contributing to the themes comprising the morphology of Colonias housing fronts. A classical pattern of migration as well as maintained contact and continuous dialogue between residents and their kin were found to result in preserving the inherent native culture of the Colonias’ residents and can thus be considered as core elements. This preservation of native culture was indicated by utilization of semi-private space, traditional roof forms, privacy and security elements, and building rituals. The study also identified additional secondary modified elements, represented by the lack of gates utilization as a measure of security. These core and modified elements coincide with the Geddes and Bertalanffy model and therefore it can be deduced that this model can be applied in the case of the Colonias.

Thesis (Ph. D.)--University of Chicago, Department of Geophysical Sciences, December 2003. / CD-ROM contains figures 2.1-4.8 and A.1 in PDF format. Includes bibliographical references. Also available on the Internet.

Inaug.-Diss.--Bern.