<p>Germ cells represent the immortal line: they are guardians of a totipotent genome and are essential for the genetic survival of an individual organism and ultimately a species. An error at any stage in development (specification, migration, colonization, differentiation, adult maintenance) can lead to one of two disastrous outcomes: (1) germ cell death or (2) unchecked growth and proliferation leading to tumorigenesis. The work in this dissertation utilizes a classic mouse model (<italic>Ter</italic>) resulting in both of these phenotypes to further explore the molecular mechanisms important for development of germ cells. </p> <p>A homozygous nonsense mutation (<italic>Ter</italic>) in murine <italic>Dnd1</italic> (<italic>Dnd1<super>Ter/Ter</super></italic>) results in a significant (but not complete) early loss of primordial germ cells (PGCs) prior to colonization of the gonad in both sexes and all genetic backgrounds tested. The same mutation also leads to testicular teratomas only on the 129/SvJ background. Male mutants on other genetic backgrounds ultimately lose all PGCs with no incidence of teratoma formation. It is not clear how these PGCs are lost, develop into teratomas, or what factors directly control the strain-specific phenotype variation. </p> <p>Work here demonstrates that <italic>Dnd1</italic> expression is restricted to germ cells and that the <italic>Ter</italic> mutant defect is cell autonomous. The early loss of germ cells is due in part to BAX&ndash;mediated apoptosis which also affects the incidence of tumorigenesis on a mixed genetic background. Moreover, tumor formation is-specific to the male developmental pathway and not dependent on sex chromosome composition of the germ cell (XX vs. XY). Despite normal initiation of the male somatic pathway, mutant germ cells fail to differentiate as pro&ndash;spermatogonia and instead prematurely enter meiosis.</p> <p>Results here also reveal that, on a 129/SvJ background, many mutant germ cells fail to commit to the male differentiation pathway, instead maintain expression of the pluripotency markers, NANOG, SOX2, and OCT4, and initiate teratoma formation at the stage when male germ cells normally enter mitotic arrest. RNA immunoprecipitation experiments reveal that mouse DND1 directly binds a group of transcripts that encode negative regulators of the cell cycle, including <italic>p27Kip1</italic>, which is not translated in <italic>Dnd1<super>Ter/Ter</super></italic> germ cells. Additionally, overexpression of DND1 in a teratocarcinoma cell line leads to significant alteration of pathways controlling the G1/S checkpoint and the RB tumor suppressor protein. This strongly suggests that DND1 regulates mitotic arrest in male germ cells through regulation of cell cycle genes, serving as a gatekeeper to prevent the activation of a pluripotent program leading to teratoma formation. Furthermore, strain&ndash;specific morphological and expression level differences possibly account for sensitivity to tumor development.</p> / Dissertation

<p>The main concern of this work is the development of methodsfor automatic condition monitoring of control loops withapplication to the process industry. By condition monitoringboth detection and diagnosis of malfunctioning control loops isunderstood, using normal operating data and a minimum amount ofprocess knowledge.</p><p>The use of indices for quantifying loop performance is dealtwith in the first part of the thesis. The starting point is anindex proposed by Harris (1989). This index has been modifiedin order to cover a larger range of processes. The same conceptis then used to assess the sampling rate in control loops.Other index-based monitoring methods where some amount ofprocess knowledge is available are discussed.</p><p>The evaluation of the performance indices discussed requiresknowledge of the process dead-time. Therefore a concept calledevent-triggered estimation is introduced in the second part ofthe thesis. Both automatic data selection and dead-timeestimation methods are proposed and conditions for successfulestimation are discussed.</p><p>The last part of the thesis deals with the diagnosis ofoscillations. A method to automatically diagnose staticfriction (stiction) in the actuator is presented. Furthermore,two methods are proposed which allow automatic distinction ofexternally and internally generated oscillations. All describedmethods have been implemented in a MATLAB-based graphical userinterface which is briefly described.</p>

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2002. / Thesis statement in Swedish and English abstract inserted. Appendix reprints four papers and manuscripts, three co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

This thesis consists of two research problems in the air conditioning (A/C) area. For the first problem, the aim is to model and simulate a variable refrigerant flow (VRF) air conditioning system. The coefficient of performance (COP) for refrigeration or heat pump system is one of the critical parameters for designing an air conditioning system. The modeling of the system components for a VRF cycle under different cooling conditions using R-134a and R-22 as refrigerants was carried out. Calculations were performed by varying different parameters such as condenser and evaporator temperatures, and refrigerant type. The R-134a refrigerant shows a better performance when multiple evaporators are present. Part load performance evaluation was also done for both refrigerants. The simulation results compared reasonably well with available experimental data. In the second problem, the objective is to develop a mathematical model that covers the mass, energy, entropy, and exergy balances of a typical air conditioning system. The model examines how the exergy efficiency of an air conditioning system can be used to measure its performance, bypass configuration, and additional significant environmental factors that affect an A/C system's design. The effects of outside air parameters, room parameters, room sensible and latent heat loads, and dead state properties on exergy efficiency were investigated. The range of parameters covered included outside air temperature (To= 25-60oC) and relative humidity (RHo = 50-85%), sensible heat load (Qsen = 11.50-13.25 kW), latent heat load (Qlat = 3.00-4.75 kW), room air temperature (Tr= 18-25oC), and relative humidity (RHr= 30-44%), and outside-mixture air flow rate ratio (qo/qm = 0.21-0.71). Two novel dead state conditions were selected to further analyze their effects on the system. Present exergy results indicate that an A/C system is quite sensitive to air properties, sensible and latent cooling loads, and dead state conditions.

This project explores how musical improvisational processes come into being through interacting discursive power relationships that are embodied and enacted through performance. By utilizing the concepts of framing and performativity I am able to show how discursive power constitutes the performance of improvisational music. To exemplify this theory, the project presents a case study examining a Grateful Dead cover band named Uncle John's Band that performs at Skipper's Smokehouse in Tampa, FL. Using an ethnographic methodology, the project articulates the dominant discursive power relationships that constitute Uncle John's Band's improvisational performances. The dominant discursive power relationships revolve around the lived philosophies and performance style of the Grateful Dead as embodied and communicated through performance by the members of Uncle John's Band. Dominant discursive power relationships also form among audience members as well as the staff at Skipper's Smokehouse. All of these power relationships constitute the performance of improvisational music. In a reflexive turn, the project also offers a re-articulation of ethnography through the tenets of improvisation. Finally, the project presents conclusions concerning the nature of researching improvisational music performance and some future directions for this study.

The United States Navy incorporates many different occupations to ensure it achieves its overall mission. These occupations are extremely diversified and present a wide spectrum of occupational exposures. Many of these exposures have been well studied and documented. However, shipboard pneumatic tool hand-arm vibration, (HAV) and how it relates to different body postures is an area of occupational exposure that has received little attention. The chief objective of this study was to assess whether there is a difference in hand-arm vibration levels, while working on one of two surface orientations (e.g., horizontal and vertical) among distinctly different pneumatic tools while cleaning or not cleaning. The design of the study evaluated three pneumatic tools cleaning both horizontal and vertical surfaces and the fourth tool only cleaning a horizontal surface. HAV levels were measured to identify the effect horizontal and vertical surface orientations had on the tool. Five subjects were used in the evaluation of the four tools by a random sequencing order. Each subject was required to hold the tool in an idle condition, an activated without cleaning condition, and an activated cleaning condition, (surface contact) for 20 seconds each. These conditions were evaluated in two different surface orientations; horizontal and vertical (except for the 4th tool). Each subject repeated each of the cleaning/not cleaning conditions three times for a total of 7 measurements per surface. The idle condition was only conducted one time for each tool and surface. The measurements were collected from a Quest, HAVPro instrument using an accelerometer on the pneumatic tool following ISO 5349-1:2001 and ISO 5349-2:2001 methods.A three-way ANOVA (subjects by tool, by condition, (cleaning vs. not cleaning) and tool vs. condition) with replicates (not including idle conditions) was conducted on the data. The analysis included the main effects and the interaction of tool and surface orientation. The subjects were treated as a blocking variable. All the main effects and the interaction were significant at p<0.0001, except for surface, p<0.6396. Surface orientation does not affect HAV levels in pneumatic tools.

No description available.

This study aims to find out how gender roles are portrayed in the series The Walking Dead. Using a quantitative content analysis where every episode of The Walking Dead was analyzed the study shows gender role portrayal in the everyday activities done by the characters. A qualitative study based on a semiotic analysis was also executed where focus lies on analyzing the characters attributes and their trait of character. The result shows that the series maintains a stereotypical representation of men and women. The men take on the typical “manly” work and the women do the majority of the domestic work. The killing of zombier and humans are mostly done by the men in the series. Their trait of character also shows a stereotypical gender role representation where the men are portrayed as tough, fighters, protectors and providers. The women on the other hand are more weak, sensitive and dependent.

A generalized approximate hand method of analysis is presented for determining the lateral deflections and internal forces in complex multi-storey structures subject to lateral loading. The buildings may include symmetric or asymmetric combinations of coupled walls, rigid frames, shear walls, wall-frames, rigid frames with central walls, frames with single and multi-storey bracing systems as well as cores that are either open or partially closed by floor beams. The deformations taken into account include bending, axial, shear and torsion. / The analysis is based on the continuous medium technique in which the bents in the structure are replaced by idealized assemblies representing their characteristic modes of behaviour. The proposed method is restricted to structures with uniform geometry up the height and linear elastic behaviour of the structural members. / Design equations are presented for the conventional lateral loading cases: a concentrated load at the top of the structure, a uniformly distributed load, and a triangularly distributed load with maximum intensity at the top. The simplicity of this method allows the sway of a structure, the maximum storey sway and its location in the height of the structure to be determined graphically. This procedure enables not only a rapid estimate of the deflections in the structure but together with an assessment of the internal forces it provides a design office method of comparing the efficiencies of different structural alternatives in the preliminary design of tall building structures.

Human immunodeficiency virus (HIV) is the causing agent of the acquired immune deficiency syndrome (AIDS). Like all retroviruses, HIV carries two copies of viral genomic RNA in each virion. HIV genome encodes three structural genes, including gag, pol and env, as well as two regulatory genes (rev and tat) and four accessory genes (vif, vpr, vpu and nef). It is noted that none of these nine viral proteins bears the helicase activity. Helicases are able to unwind RNA duplex and remodel the structure of RNA-protein (RNP) complexes using energy derived from hydrolysis of nucleotide triphosphates (NTPs). They are involved in every step of cellular RNA metabolisms. It is conceivable that HIV needs to exploit cellular RNA helicases to promote the replication of its RNA at various steps such as transcription, folding and transport. / In this study, we found that a DEAD-box protein named DDX24 associates with HIV-1 Gag in an RNA-dependent manner but is not found within virus particles. Knockdown of DDX24 inhibits the packaging of HIV-1 RNA and thus diminishes viral infectivity. The decreased viral RNA packaging as a result of DDX24-knockdown is observed only in the context of the Rev/RRE (Rev response element)-dependent but not the CTE (constitutive transport element)-mediated nuclear export of viral RNA, which is explained by the specific interaction of DDX24 with the Rev protein. We propose that DDX24 acts at the early phase of HIV-1 RNA metabolism prior to nuclear export and the consequence of this action extends to the viral RNA packaging stage during virus assembly.