Thesis (M.S.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 90-110). Also available on the World Wide Web.

In this thesis I investigate social processes that motivate the contemporary reproduction and public dissemination of older Central Coast Salish spindle whorls. In a case study, I develop a cultural biography of spindle whorls to examine how material culture produced by past generations informs contemporary activity. Visual materials, first- and third-person accounts and writings in three areas—material culture, the social nature of art and colonialism—are drawn together to demonstrate that spindle whorl production and circulation is grounded in social and historical contingencies specific to Central Coast Salish First Nations. I propose that in using spindle whorls, Central Coast Salish people are drawing on the past to strengthen their position within current circumstances. / Arts, Faculty of / Anthropology, Department of / Graduate

The aim of this work was to propose an analytical spindle lathe and perform simulations to verify that the spindle is designed correctly. After calculations and modeling of the whole assembly, I began to make the first simulation in ADAMS. I proceeded from simple models over difficult to the final version of the entire assembly. I examined whether they match the values of power, speed, strength and other values with the values obtained analytically. The results of my works are virtual models of spindle, which can simulate various stressful conditions under which we can decide whether the spindle is satisfactory or not.

This master’s thesis deals with design of spindle for small three axis milling machine. The first part of this thesis includes research in milling spindles and overview of several spindles from different manufacturers. The second part deals with calculation of necessary parameters, design of spindle and subsequent simulation verification. This thesis also includes a 3D model of spindle, assembly drawing and four manufacturing drawings.

Indiana University-Purdue University Indianapolis (IUPUI) / The Fanconi anemia (FA) pathway consists of 21 genes that maintain genomic stability and prevent cancer. Biallelic mutations within this network cause Fanconi anemia, an inherited bone marrow failure and cancer predisposition syndrome. Heterozygous inborn mutations in FA genes increase risk of breast/ovarian cancers, and somatic mutations occur in malignancies in non-Fanconi patients. Understanding the tumor suppressive functions of FA signaling is important for the study of Fanconi anemia, inherited cancers, and sporadic cancers. The FA network functions as a genome guardian throughout the cell cycle. In addition to the well-established roles of FA proteins in interphase DNA replication/repair, the FA pathway controls mitosis by regulating the spindle assembly checkpoint (SAC) to ensure proper chromosome segregation. The SAC consists of several tumor suppressors, including Mad2, and SAC impairment predisposes to aneuploidy and cancer. However, the in vivo contribution of SAC dysfunction to malignant transformation of FA-deficient cells remains unknown. Furthermore, the mechanisms by which FA proteins regulate the SAC are unclear. To test whether SAC dysfunction drives genomic instability and tumorigenesis in FA, we generated a novel FA-SAC model by intercrossing Fancc-/- and Mad2+/- mice. The intercrossed mice displayed heightened aneuploidy secondary to exacerbated SAC dysfunction. Importantly, these mice were prone to developing hematologic malignancies, particularly leukemia, faithfully recapitulating the clinical phenotype of Fanconi anemia. Upon establishing SAC dysfunction as a driver of tumorigenesis in FA, we next explored the mechanism by which FANCC regulates the SAC. We demonstrated that the mitotic kinase CDK1 phosphorylates FANCC to regulate subcellular localization and SAC function of FANCC during mitosis. Our study highlights the essential role of compromised chromosome segregation in the development of leukemia due to impaired FA signaling. This work furthers our knowledge of FANCC signaling at the SAC, and has implications for future use of mitotic-centered therapies for FA-associated tumors. / 2 years

The development and maintenance of multicellular organisms depends fundamentally on cell division, a series of events largely mediated by the mitotic spindle. Errors in spindle formation and/or function are often associated with severe consequences, most notably cancer. In order to elucidate the cause of such errors and the potential for therapeutic intervention, it is imperative to attain a clear understanding of how cell division normally operates. In this regard, this dissertation focuses on the activity of two microtubule-based motor proteins, Eg5 and dynein, prior to and immediately following nuclear envelope breakdown during mitosis. I show that prophase microtubules are remarkably more dynamic than their metaphase counterparts, moving both toward and away from centrosomes across a wide distribution of rates. Inhibition of Eg5, dynein and Kif2a revealed that a subset of this motion is consistent with microtubule flux, a well-established phenomenon temporally limited to metaphase and anaphase spindles by the preceding literature. My data indicates that flux is operational throughout all of mitosis, possibly functioning at early stages to collect centrosomal components. Immediately following prophase, cells begin assembling bipolar spindles. While the establishment of spindle bipolarity fails in the physical or functional absence of Eg5, I show that co-inhibition of dynein restores a cell’s ability to organize microtubules into a bipolar structure. Despite inhibition of both Eg5 and dynein, these spindles are morphologically and functionally equivalent to controls. Together, these data suggest that Eg5 and dynein share an antagonistic relationship and that a balance of forces, rather than a definitive set of players, is important for spindle assembly and function. To determine how Eg5- and dynein-mediated forces functionally coordinate to bring about antagonism during spindle assembly, I utilize a nocodazole washout assay. I show, via in vivo imaging and in silico modeling, that spindle collapse in the absence of functional Eg5 requires dynein activity and an initial intercentrosomal distance of less than 5.5μm. These data are consistent with a model in which dynein antagonizes Eg5 by crosslinking and sliding antiparallel microtubules, a novel role for dynein within the framework of spindle assembly.

The water crisis has been an increasing challenge in some places in the world. One proposed solution that has drawn lots of attention is fog harvesting. A commonly used fog collector is a vertical mesh, usually made of poly materials. Small water droplets can easily get pinned and quick evaporation is the major common challenge for vertical meshes. Coating the fog mesh with superhydrophobic chemicals is one of the solutions. However, superhydrophobicity is not durable and it may contaminate the collected water. In addition, it requires a high professional maintenance and laboratory operation standard. As a result, it is impractical to set such fog collectors in regions and countries with water crisis. Low cost, harmless, easily fabricated, higher coalesce rate and low maintenance are the five pillars for this research. This thesis topic is inspired by spider silk's ability to direct water droplets to certain locations to further enhance water collecting rate. This directional droplet movement is caused by spindle-knot and joint structure on the biomimetic silk. The spindle-knot is randomly porous, and the joint is stretched porous. In addition, the spindle-knot has a tilted angle β above the joint region. Due to these unique structures, there are three droplet movement controlling forces – surface tension force, hysteresis force, and Laplace pressure force. This thesis presents detailed equation derivations for each driving force in the introduction section. Spindle-knot is the pivot point to direct water, forming the spindle-knot structure is another focus of this thesis. Fluid coating and dip-coating with dimethylformamide (DMF), a solvent with a low evaporation rate, is the highly used methods to form the spindle-knot structures due to its simple setup and low cost. However, DMF is an extremely hazardous organic compound, and it requires high laboratory operation standards. In the second section of this thesis, DMF has been replaced with water/ethanol and photocurable materials to construct the spindle-knots. Furthermore, Additive manufacturing (3D printing method) was adopted to synthesize bionic spider web with spindle-knot structures. / Master of Science / Water shortage is one of the highest concerns all around the world and collecting fog water has drawn lots of attention recently. The focus of this thesis is to increase the fog collection rate by using less hazardous, low maintenance and low-cost methods. Commonly used fog collector is a large vertical plastic mesh. However, those large meshes suffer from water pinning and easily evaporation issues. Water repellent chemicals have been studied and used to dissolve those issues, however, the chemical coating will not last long and it will contaminate the collected water easily. Moreover, coating the water repellent chemicals requires professional operation and maintenance. To solve this issue without using chemical coating, we have learned unique water collection and directional behavior from spider silk. In a humid day, you will easily find the spider web with fully covered water droplets in an organized order. If we zoom in on single spider silk, the spider silk is composed of many puff and joint regions. Those puff regions have higher water collection ability than the joint regions, and this puff region shrinks down to form the spindle-knot shape with angle β above the joint region. This unique spindle-knot structure induces the water directional movement, and three forces- surface tension force, pinning force, and Laplace pressure force – are controlling the moving direction. Chapter 1 shows equation derivations with surface material effects, surface roughness effects and water droplet landing location effects. To form such special spindle-knot structure, commonly used formation methods are fluid coating and dip coating by using an organic polymer solvent. However, commonly used organic polymer-solvent suffer from a high level of hazardous, resulting in high laboratory requirement and operation cost. In Chapter 2 of this thesis, that commonly used organic polymer-solvent will be replaced by water/ethanol mixture and light-sensitive materials to form the spindle-knots. Furthermore, the 3D printing method is adopted to build a spider web with spindle-knot structures.

Kinesin superfamily motors have a well-characterized ability to move along microtubules and transport cargo. However, some members of the kinesin superfamily can also remodel microtubule networks by controlling tubulin polymerization dynamics and by organizing microtubule structures. The kinesin-8 family of motors play a central role in cellular microtubule length control and in the regulation of spindle size. These motors move in a highly processive manner along the microtubule lattice towards plus ends. Once at the microtubule plus end, these motors have complex effects on polymerization dynamics: kinesin-8s can either destabilize or stabilize microtubules, depending upon the context. My thesis work identified a tethering mechanism that facilitates the processivity and plus end-binding activity of Kip3 (kinesin-8 in budding yeast), which is essential for the destabilizing activity of kinesin-8 in cells. A concentration-dependent model was proposed to explain the divergent effects of Kip3 on microtubule dynamics. Moreover, a novel activity of Kip3 in organizing microtubules was discovered: Kip3 can slide anti-parallel microtubules apart. The sliding activity of Kip3 counteracts the depolymerizing activity of Kip3 in controlling spindle length and stability. A lack of sliding activity causes fragile spindles during the process of chromosome segregation in anaphase. The tail domain of Kip3, which binds both microtubules and tubulin dimers, plays a critical role in all these activities. Together, my work defined multiple mechanisms by which Kip3 remodels the microtubule cytoskeleton. The physiological importance of these regulatory mechanisms will be discussed.

Cells must faithfully segregate their chromosomes at division; errors in this process causes cells to inherit an incorrect number of chromosomes, a hallmark of birth defects and cancer. The machinery required to segregate chromosomes is called the spindle, a bipolar array of microtubules that attach to chromosomes through the kinetochore. Replicated chromosomes contain two sister chromatids whose kinetochores must attach to microtubules from opposite poles to ensure correct inheritance of chromosomes. The spindle checkpoint monitors the attachment to the spindle and prevents cell division until all chromatids are attached to opposite poles. Both the spindle and the checkpoint are critical for correct segregation, and we sought to understand the regulation of these two components. The spindle is assembled to a characteristic metaphase length, but it is unknown what determines this length. It has been proposed that spindle length could be regulated a balance of two forces: one generated by interaction between microtubules that elongates the spindle and a second due to interactions between kinetochores and microtubules that shortens the spindle. We tested this force-balance model which predicts that altering the number of kinetochores will alter spindle length. We manipulated the number of kinetochores and found that spindle length scales with the number of kinetochores; introducing extra kinetochores produces shorter spindles and inhibiting kinetochores produces longer spindles. Our results suggest that attachment of chromosomes to the spindle via kinetochores produces an inward force that opposes outward force. We also found that the number of microtubules in the spindle varied with the number of kinetochores. In addition to establishing a spindle, cells must also guarantee that chromosomes are correctly attached to it. Correct attachment generates tension as the chromatids are pulled toward opposite poles but held together by cohesin until anaphase. The spindle checkpoint monitors this tension which causes stretching of chromatin and kinetochores. Lack of tension on activates the checkpoint, but is unknown if the checkpoint measures stretch between kinetochores (inter-kinetochore stretch) or within kinetochores (intra-kinetochore). We tethered sister chromatids together to inhibit inter-kinetochore stretch and found that the checkpoint was not activated. Our results negate inter-kinetochore models and support intra-kinetochore models.