Thesis (M.S.P.H.)--University of Michigan, 1931.

Thesis (M.H.S.A.)--University of Michigan, 1976.

Thesis (M.H.S.A.)--University of Michigan, 1982.

Thesis (Ph. D.)--University of Michigan, 1966. / Includes bibliographical references (p. 325-328).

Intellectual disability (ID) is a common phenotype of brain-development disorders and is heterogeneous in etiology with numerous genetic causes. PAK3 is one gene with multiple mutations causing ID. Affected individuals have microcephaly, and other brain-structure defects have been reported. Additionally, PAK3 is in a genetic network with eighteen other genes whose mutations cause ID, suggesting the molecular mechanisms by which PAK3 regulates of cognitive function may be shared by other genetic ID disorders. Studies in rodent models have shown that the orthologs of PAK3 are important for regulating dendrite spine morphology and postnatal brain size. In Drosophila melanogaster, the morphological processes of oogenesis, dorsal closure during embryogenesis, and salivary gland-lumen formation require Pak, the Drosophila ortholog of PAK3. Additionally, Pak is important for development of the subsynaptic reticulum of the neuromuscular junction, sensory axon pathfinding and terminal arborization in the Drosophila central nervous system (CNS). However, the role of Pak in mushroom body (MB) structure and intrinsic neurite arbor morphogenesis, as well as details of the underlying cellular and molecular mechanisms are unknown. To address this gap, I used Drosophila models of PAK3 gene mutations, Pak, and a combination of immunostaining, primary cell culture, and genetic interaction studies to elucidate these mechanisms. I performed a detailed characterization of the previously reported adult Pak phenotypes of decreased survival as well as leg and wing morphology. I found that decreased survival is a low-penetrance phenotype that is enhanced by chromosomes from the same mutagenesis. Defects of the adult wing include folding and misalignment between the layers, blisters, and missing or partial cross veins. The Pak-mutant legs are short and often misdirected in the pupal case with morphological defects in the shape of the leg segments themselves. The mushroom bodies are important insect learning and memory brain structures whose lobes are composed of axon bundles with individual axons bifurcating to form the α and β lobes. Mutations in Pak cause defects in the length, thickness, and direction of the MB α and β lobes. These defects increase in severity during metamorphosis, when neurogenesis and differentiation of these structures occur, suggesting that Pak stabilizes the branches of the α/β mushroom body neurons. Pak-mutant cultured neurons have reduced neurite arbor size with defects in neurite caliber. Initial outgrowth was normal, followed by a decrease in neurite branch number, again supporting the role of Pak in neurite-branch stability. There are defects in the cytoskeleton in growth cones at six hours post-plating as well as in neurons after three days in vitro. The Pak-mutant phenotype severity depends on the phosphorylation status of myosin regulatory light chain, supporting the mechanistic hypothesis that Pak regulates neurite-branch stability by inhibiting myosin light chain kinase. The neuronal phenotype of decreased branch stability suggests a mechanism of excessive retraction as the cellular pathogenesis underlying PAK3 mutation-associated brain disorders. I used western blotting to characterize the protein products of four nonsense mutations in Drosophila Pak to interpret genotype-phenotype relationships. Each allele has molecularly unique consequences: Pak¹¹, stop-codon read through and truncated protein; Pak¹⁶, no read through, but truncated protein; Pak⁶, read through with no truncated protein; Pak ¹⁴, neither readthrough nor truncated protein. Truncated proteins produced by Pak¹¹ and Pak¹⁶ alleles retained partial function for survival, wing blistering, leg morphology, and neurite length. Conversely, truncated protein increased the severity of the mushroom body defects. Truncated proteins have no effect on neuron branch number, wing folding, or vein defects. Together, these results demonstrate a role of Pak in regulating epithelial morphology, brain structure, and neurite arbor size and complexity. These closely resemble features of the human disorder, providing evidence that this is a good genetic model for this cause of ID.

Regression models were developed to predict scenic quality for residential streets in Ann Arbor, Michigan for both Summer and Winter vegetative conditions. Scenic quality was quantified using the Scenic Beauty Estimation method. Only variables that existed in the city's computer data base were used. Variables such as diameter at breast height, basal area, number of trees, and tree species diversity were investigated as to their predictive ability. In addition, the predictive ability of quadratic, power, inverse, and logarithmic transformations of these variables was investigated. The best predictive Summer model used the natural log of the average diameter of street trees and the natural log of the average assessed property value as variables. The best predictive Winter model used the natural log of the average diameter of street trees as its independent variable. / Master of Science / incomplete_metadata

No description available.

This thesis is about the use of trees for commemoration and the memory that they have anchored in the landscape. There has been little written on the use of trees for commemorative purposes despite its symbolic resonance over the last 150 years. To determine the extent to which commemorative trees have been employed, the social practice and context in which the trees were planted, field and archival work was undertaken in New Zealand and Australia. This has been supported with some comparative work using examples from Britain and the United States of America. The research also utilizes the new availabilities of records on-line and the community interests that placed historical and contemporary material on-line. The commemorative tree has been a popular commemorative marker for royal events, the marking of place and as memorial for war dead. It has been as effective an anchor of memory in the landscape as any other form. The memory ascribed to these trees must be understood in terms of the era in which the tree was planted and not just from a distance. Over time the memory represented by the trees and its prescribed meanings, has changed. For all its power and fragility, memory is not permanent but nor is it so ephemeral as to exhibit no robustness at all. Instead memory exists in a state of instability that leaves it open to challenge and to constant reassessment based on the needs of the viewing generation. This instability also allows the memory, and thus the tree, to fade and become part of the domestic landscape of treescape memories (Cloke and Pawson, 2008). However, in some circumstances trees are retrieved and reinscribed with specific memory and made relevant for a new generation. The landscape created by commemorative trees is, therefore, multifunctional, in which social relations support memory, remembrance, forgetting, silences, erasures, and memory slippage.

Thesis (MA. Agricultural Management (Animal Production)) -- University of Limpopo, 2014 / This study determined the effect of carrot meal supplementation on productivity and carcass characteristics of Arbor acres broiler chickens aged one to six weeks. Experiment I determined the effect of carrot meal supplementation on productivity of Arbor acre broiler chicks aged one to 21 days. Two hundred unsexed Arbor acre broiler chickens were randomly assigned to five treatments with five replicates, each replicate having ten birds. A completely randomized design was used in the first experiment. The treatments were 0 (UA0), 20 (AU20), 50 (AU50), 75 (AU75) or 100 (AU100) g of carrot meal supplementation per kg DM feed. Quadratic equations were used to determine levels of carrot meal supplementation for optimal feed intake, metabolisable energy intake and nitrogen retention of Arbor acre broiler chickens aged one to 21 days. Linear equations were used to determine relationships between carrot meal supplementation and productivity variables. Dietary carrot meal supplementation had no (P>0.05) effect on growth rate, live weight and feed conversion ratio of unsexed Arbor acre broiler chickens aged one to 21 days. Carrot meal supplementation, however, improved (P<0.05) metabolisable energy intake and nitrogen retention of the chickens. Dietary metabolisable energy intake and nitrogen retention of the chickens were optimized at different carrot meal supplementation levels of 40.5 and 53.57 g/kg DM feed, respectively. No chicken deaths were recorded. Experiment II determined the effect of carrot meal supplementation on productivity and carcass characteristics of female Arbor acre broiler chickens aged 22 to 42 days. The chickens were randomly allocated to five treatments with five replicates, each having 10 birds, in a completely randomized design. The supplementation levels were 0 (FA0), 20 (FA20), 50 (FA50), 75 (FA75), or 100 (FA100) g of carrot meal per kg DM feed. Quadratic equations were used to determine levels of carrot meal supplementation for optimal feed intake, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention of broiler chickens aged 22 to 42 days. Linear equations were used to determine relationships between carrot meal supplementation and production variables. Dietary carrot meal supplementation had no (P>0.05) effect on growth rate, live weight and carcass parts of female Arbor acre broiler chickens aged 22 to 42 days. Carrot meal supplementation improved (P<0.05) feed intake, feed conversion ratio, metabolisable energy intake and nitrogen retention of Arbor acre broiler chickens aged vi 22 to 42 days. Dietary feed intake, feed conversion ratio, live weight, metabolisable energy intake and nitrogen retention were optimized at different dietary carrot meal supplementation levels of 52.8, 63.8, 38.0, 42.0 and 44.3 g/kg DM feed, respectively. Dietary carrot meal supplementation had no effect (P>0.05) on tenderness and flavour of female Arbor acre broiler meat. Broiler chickens on diets supplemented with 20, 50 or 100 g of carrot meal per kg DM feed produced meat with better (P<0.05) juiciness values than those of meat from chickens not supplemented with dietary carrot meal and those supplemented with 75 g/kg DM feed. There was a positive relationship between carrot meal supplementation and chicken meat juiciness. It is concluded that carrot meal supplementation improved (P<0.05) metabolisable energy intake and nitrogen retention of unsexed Arbor acre broiler chickens aged one to 21 days. However, carrot meal supplementation had no effect (P>0.05) on growth rate, live weight and feed conversion ratio of unsexed Arbor acre broiler chickens aged one to 21 days. Carrot meal supplementation improved (P<0.05) intake, feed conversion ratio, metabolisable energy and nitrogen retention of female Arbor acre broiler chickens aged 22 to 42 days. However, carrot meal supplementation did not (P>0.05) improve growth rate and live weights of the chickens.

Magistro darbe tiriama paprastojo buko (Fagus sylvatica L.) paplitimas, medynų sudėtis ir struktūra Norkaičių girininkijoje Darbo objektas – paprastojo buko medynai Norkaičių girininkijoje. Darbo metodai: Medynai su buku Norkaičių girininkijoje buvo parinkti dviejuose kvartaluose – 66 (sklypai 3; 4) ir 67 (sklypai 1;2), nes labiausiai juose buvo paplitęs paprastasis bukas. Parinkti tokie medynai: grynas bukynas (1 barelis Bu1-1); pušynas su paprastuoju buku (4 bareliai Bu3-1, Bu3-2; Bu4-1, Bu4-2); ąžuolynas su paprastuoju buku (2 bareliai - Bu2-1; Bu2-2). Buvo įrengti skrituliniai tyrimo bareliai, kuriuose nustatyta medyno struktūra, atskirų ardų dendrometrinė charakteristika, trako ir pomiškio rūšinė sudėtis ir gausumas, žolinės ir samanų dangos sudėtis ir gausumas. Darbo rezultatai. Didžiausias paprastojo buko medynų plotas buvo 1991 metais – 38.4 ha, dėl polajinių ir savaiminių želdinių įveisimo. Gryname bukyne vidutinis medyno amžius – 75 metai, skersmuo 1,3m. aukštyje – 25,1 cm, aukštis 25,8 cm, skerspločių suma – 25,1m2 / ha, tūris – 295 m3/ha. Gryname bukyne rasta paprastojo buko (10800 vnt/ha) ir paprastojo klevo (400 vnt/ha) savaiminukų. Pušynų su buko antruoju ardu vidutinis amžius buvo 70 metų, skersmuo 1,3 m aukštyje – 28,2 cm, bukų ardo vidutinis aukštis – 28,1 m, lajos skerspločių suma – 23,2 m2/ha, tūris -291 m3/ha. Šiame barelyje daugiausiai rasta paprastojo klevo savaiminukų ( 46000 vnt/ha mažiausiai – paprastojo buko... [toliau žr. visą tekstą] / Final work searching simplex beech (Fagus sylvatica L.) spreading, trees composition and structure in Norkaiciai district. The object of the study – simplex beech trees in Norkaičiai district. Method of the study: trees with beech Norkaičiai district was choose in two blocks - 66 (3;4 plots) and 67 (1;2 plots) because there was a lot of simplex beech. Choose these: pure beech (1 plot Bu1-1); pine trees with beech (4 plots Bu3-1, Bu3-2, Bu4-1 Bu4-2); oak with beech (two plots Bu2-1-; Bu2-2). Was arrange circle analysis plots, there was establish trees structure, diferences layer characteristic, glade and forest kind speading and adbundance of plants. Results of the study. Maxima simplex beech stat in area esset in 1991 - 38,4 ha hospitiis et spontanea lignum plantationis herba. Beech stet aperta mediocris aetatis - 75, diametrum - 25,1 cm 25,8 cm altum, basalibus area - 25,1 m2/ ha, Volume - 295 m3/ha. Pure beech (10800 vnt/ha) and maple (200 vnt/ha) trees. Pinus with second beech layer 70 years, diametrum – 28,2 cm, fagus quatit mediocris altitudo - 28,1 m, coronam basalibus area - 23,2 m2/ha, Volume -291 m3/ha. In these area was most maple trees (46000 vnt/ha), beech (200 vnt.ha). Oak with second beech layer 70 years old, altitudo diametrum - 16,7 cm, in mediocris altitudo fagus - 23,9 m corona basalibus area - 17,1 m2/ha, Volume 194 m3/ha.