VictorJuiz/thesis huggingface dataset:
Low temperature-induced changes in fatty acid desaturation in the major glycerolipids from the leaves of a Brassica napus mutant

The major chloroplast lipid, monogalactosyldiacylglycerol, of a mutant Brassica napus showed reduced levels of trienoic fatty acids (16:3 and 18:3) when plants were grown at 5$\sp\circ$C, but not at 20$\sp\circ$C and 30$\sp\circ$C. Similar reductions in the rate of fatty acid desaturation in monogalactosyldiacylglycerol at low temperature was observed in the mutant plants grown at 20$\sp\circ$C and 30$\sp\circ$C and then acclimated to 5$\sp\circ$C. This reduced rate of fatty acid desaturation at low temperature in the mutant leaves was also reflected in digalactosyldiacylglycerol, another chloroplast lipid which is synthesized from monogalactosyldiacylglycerol. In contrast, phosphatidylcholine, a major cytosolic lipid, from the same mutant plant grown at 5$\sp\circ$C showed higher level of 18:3 than plants grown at 20$\sp\circ$C and 30$\sp\circ$C. The increased rate of fatty acid desaturation in phosphatidylcholine at low temperature was also observed in the mutant plants grown at 20$\sp\circ$C and 30$\sp\circ$C and then acclimated to 5$\sp\circ$C. Therefore, this low temperature-sensitive mutation in the leaf affects the rates of fatty acid desaturation only in the membranes of the chloroplast. Reciprocal backcross analysis indicated that the gene affected by this mutation was at a single nuclear locus and inheritance was additive. Estimates of the rates of activity of the different chloroplast desaturases, using a computer model based on in vivo $\sp{14}$CO$\sb2$ labelling, showed that the mutation significantly affects the activities of $\omega$9- and $\omega$6-desaturases which are primarily responsible for low temperature-induced desaturation. The levels of activity of these two desaturases increased markedly in non-mutant leaves during acclimation from 20$\sp\circ$C to 50$\sp\circ$C, while there was little or no change in their rates of activity in the mutant leaves during the same acclimation period. The activity of $\omega$3-desaturase was affected to a much less extent.
An ATM switch using Starburst packet switch fabric

In this thesis, we present the design and analysis of an ATM switch using the Starburst packet switching architecture. The first part of the thesis provides an introduction to ATM network concepts and specifications, Starburst packet switching Integrated Circuit, and the board design of the Starburst cell switch fabric. This introduction provides an overview on the internal structure, functional and design requirements of internal modules, and the overall picture of an ATM switch in the network. The second part of the thesis presents the design of the I/O module and system controller interface. This portion of the thesis defines the interface between various blocks of the switch, design criteria, and design implementation. The implementations are in the form of state diagrams, and schematics. Furthermore, guidelines and pointers are provided to enable future hardware and software implementation of the Starburst ATM switch.
Structural studies of the Flp recombinase of Saccharomyces cerevisiae complexed with DNA, implications for the mechanism of site-specific recombination

The Flp site-specific recombinase of 'Saccharomyces cerevisiae ' induces DNA bending upon specific binding to DNA and catalyzes recombination which involves a complex manipulation of DNA strands. The minimal Flp target site consists of two sequence specific binding sites which flank a core region. I have defined the position and direction of Flp-induced DNA bends. The bend induced-the noncovalent binding of two Flp molecules to the target site- was positioned in the middle of the core region and directed toward the major groove. The position and direction of bends in complexes where one strand was cleaved by Flp differed depending on whether the top or bottom strand of the target site was cleaved. A model is proposed which associates the variable position of the type II bends with a defined order of strand exchanges in the recombination reaction (Chapter 2). Mutation of the central AT base-pair in the core region altered the position of the bend induced by binding of two molecules of Flp to the FRT site as compared to an unmodified target site complexed with Flp. This mutation also affected Flp-mediated cleavage and recombination activities. The position of the DNA bend appears to be important to the functionality of the site (Chapter 3). Examination of complexes in which one of the two Flp molecules was covalently bound to the top or, bottom strands revealed cleavage- dependent conformational changes in the DNA of these complexes. An adenine residue opposite the site of cleavage was specifically protected from methylation within the cleaved, covalently bound complexes. Cleavage was also associated with changes in the interaction between the binding site and the noncovalently-bound Flp monomer in the cleavage complex. Flp- mediated cleavages of the top and bottom strands of the target site were differentially interfered with by methylation of bases opposite each cleavage site. This may provide a means to order the cleavage and subsequent strand exchange events (Chapter 4).
Nonlinear optical studies of multiphoton photoemission in silicon covered by ultrathin oxide films

Electric-field-induced second-harmonic generation (EFISH) and multiphoton photoemission (MPPE) methods are used to measure internal photoemission (IPE) of electrons from bulk Si to SiO2 films at 295 K. Charging of adsorbed O2 gas determines the evolution of the IPE process, enhances EFISH, and diminishes MPPE. These seemingly invasive nonlinear optical processes are shown to be useful probes of the Si/SiO 2 system. EFISH is used to measure surface charge accumulation due to three-photon IPE. For 0.01-to- 25-GW/cm2, 130-to-200-fs optical pulses with 1.55 eV < '&hstrok;w '< 1.75 eV the surface-charge potential barrier restricts the IPE process to SiO2 films <=10-nm thick. Linear absorption of 0.3-mW/cm2 CW light with '&hstrok;w ' >= 4.38 eV also enhances EFISH, consistent with the IPE threshold in Si/SiO2. For n-Si(100)/SiO2 samples in air or O 2, electric fields <=3 MV/cm and surface charge densities <=2 * 1013 cm-2 are attained on time scales of 0.1 s to 100 s. The time-varying component of EFISH is similar for SiO 2 films on n- and p-Si having impurity concentrations of 109 cm-3 to 1018 cm-3 . No significant EFISH increase is observed in H2, He, N2, or Ar at pressures from 1 Torr to 760 Torr. The above findings suggest that adsorbed O2 interacts with photoelectrons and may form <math> <f> <rm>O<sup>-</sup><inf><it><rm>2</rm></it></inf></rm></f> </math>. Upon 350-600-eV electron bombardment of n-Si(100)/SiO2 in vacuum, EFISH also reveals <=6 * 1012 cm -2 surface charge corresponding to (i) transient charge and (ii) electron traps with ~500-s lifetimes. MPPE produced by 1-to-30-GW/cm2, 1.55-eV, 200-fs optical pulses is also used to study the IPE and charge-transfer processes. The relative decrease (increase) in MPPE current (EFISH intensity) reveals charging of adsorbed O2. MPPE data at pressures from 10-5 Torr to 1 Torr together with EFISH data from 1 Torr to 103 Torr are consistent with Fowler-Guggenheim adsorption of ~1013 cm-2 of charged O2. The residual changes in EFISH and MPPE upon evacuation of the analysis chamber suggest charge transfer to traps in SiO2. An effective diffusion constant ~10 -7 cm2/s for the residual charge is derived using MPPE. 'In vacuo' MPPE also detects a distinct, localized class of ~1011 cm-2 electron traps.
From lover to villain, from sinner to saint, the varied career of Folco, troubadour, monk, and bishop of Toulouse, c. 1150-1231

This is the study of the life and career of one man, whose life touched on many of the important developments of his age. The subject, known variously as Folquet, Foulques, Fulk, and Folco (which I use) was born circa 1150 and died on Christmas, 1231. Coming from a Genoese merchant family, Folco rose to prominence as a troubadour in the last quarter of the twelfth century. He lived in Marseille, with his wife and children, until the 1190's when he decided to become a Cistercian monk. joining the monastery of Thoronet, he then became its abbot, and eventually attracted the attention of the Cistercian papal legates who had been sent to the Midi to reform the region. With their support, Folco was elected bishop of Toulouse in 1205. In this capacity he became deeply involved with the various efforts to combat heresy in the region. Folco worked with the legates and with Bishop Diego and Dominic, to convert heretics while he also supported orthodox outlets for catholic women religious. He was a fervent supporter of the Albigensian crusade from its inception, and one of the few participants who survived it. The problems he faced, however, were not confined to questions of dogma. Folco also had to cope with the financial difficulties his see faced, and the social tensions between the various political factions within Toulouse. The combination of these factors made him leave Toulouse several times, and he spent a large segment of his episcopacy outside of his see. During this time he was an active preacher, spending much time in the North of France and working alongside men such as Jacques de Vitry and Robert of Courson. This study aims to use Folco as a lens to examine some of the great changes that occurred in the Midi on a human, instead of an institutional, scale. Looking at society from Folco's perspective reveals it to us in a more sophisticated light. He allows us to consider why his society developed as it did, and the degree to which those developments were foreseen by those who initiated them.
Partially observed Markovian decision processes with applications

This dissertation is concerned with new solution techniques for the finite-horizon partially observed Markov decision process (POMDP), and the finite-horizon partially observed semi-Markov decision process (POSMDP). These two problems tend toward computational intractability. In fact, computational results seem to be confined to very small problems. An article by Papadimitriou and Tsitsiklis [31] (1987) explores the computational implications of POMDP, and report that it is PSPACE-complete. A PSPACE-complete problem is "...even less likely to be solved in polynomial time than the NP-complete problems" [31] (1987). Solution procedures generally fall into two categories: exact solution procedures and approximation procedures. The proposed research is in the second category. We propose heuristic methods to determine good approximate solutions for the POMDP and POSMDP. An exploratory investigation of the performance of the following solution procedures for the POMDP is provided: One-Pass algorithm, Relaxed Region algorithm, Linear Support algorithm, S. Mukherjee and K. Seth's algorithm, and our Proposed algorithm. This investigation shows the interrelations between these algorithms and the different development paths that have been taken in formulating them. In addition, a numerical comparison is performed. This comparison is based on two types of numerical evaluations. The first performance criterion is CPU runtime used during the operation of each solution procedure. We perform this evaluation because the main concern of our research is improving the speed of solution procedures for the POMDP. The second type of evaluation involves the determination of the differences in terms of the Total Expected Reward between these algorithms. Test problems were separated into four basic groups: (1) The first group contains several sets of data without any special assumption about problem structure. (2) The second group consists of "close-to-perfect information" POMDPs. (3) The third group considers the special case of the completely unobserved Markov decision process (CUMDP). (4) The fourth group considers the completely observed Markov decision process. Although the development of the heuristics is the essential theme of this dissertation, a secondary but integral part of the work is the development of a mathematical optimization control for roll surface degradation in steel processing. This problem has been deliberately chosen to show the application of the model and heuristic methods described by this work to large scale problems. Comparisons with the actual control for roll surface degradation indicates that the proposed heuristic applied to this problem can produce better results than the ones obtained with the current method.
Généalogie du manifeste littéraire

Les études du manifeste littéraire parues jusqu'ici ont ceci en commun qu'elles situent l'identité du "genre" manifestaire au niveau discursif. Notre point de départ consiste en l'idée que l'identité du texte-discours se situe toujours déjà dans le prolongement d'une activité interprétative appelée ' genre'. Pour nous, le "genre" du texte relève des ' seuils' (paratextes) ou des 'parerga' ("cadres"): les titres, les signatures, les instances préfacielles, etc. Cette théorie des genres a la particularité de ne pas réduire le manifeste à des "traits" de base. Ainsi, au lieu de poser la linéarité ou la continuité historiques du phénomène, nous pouvons modéliser un phénomène multiple et complexe; bref, nous pouvons aborder une généalogie du manifeste littéraire. Pour ce faire, nous soulignons d'abord que le manifeste politique n'est pas un phénomène séparé ou extérieur au manifeste littéraire. Nous étudions le discours de plusieurs manifestes (politiques) parus entre 1614-1848 en Europe non pas d'un point de vue typologique, mais généalogique, c'est-à-dire comme des dominations consécutives du phénomène manifestaire. En ce qui concerne le "cadre" générique nous soutenons l'importance irréductible des titres et des signatures manifestaires. Il s'agit de comprendre que même la signature demande à être interprétée; ou plus encore: tout manifeste "existe" à partir d'un acte de signature. Ensuite, en abordant le manifeste littéraire, nous reconnaissons qu'il est dominé d'une façon tout à fait particulière: il est toujours ballotté entre les points de vue des "auteurs" et des critiques. Afin de faire face à la multiplicité et à la complexité étonnantes du phénomène qui en résulte, nous proposons une démarche à la fois généalogique et typologique. Par là, il y a non seulement des signatures auctoriales, mais aussi des signatures allographes (celles des critiques littéraires); ces signatures peuvent être placées à côté du texte ('péritextes') ou en dehors du texte (' épitextes'); et finalement, l'"acte" se déroulera en trois "moments" possibles: l'"original", l'ultérieur et le tardif. D'où notre question fondamentale: "Qu'est-ce qui vaudra en tant que manifeste, pour qui et quand?".
Personal values and electronic media adoption & postadoption in urban China

This thesis examines the adoption and postadoption of television, audio cassette recorder/player (ACR), telephone, and pager. Its objective is to reveal the relationship between these four media and the social and social psychological characteristics of their adopters. This study is a direct response to the problem of the pro-innovation bias and neglect of implementation in the field of innovation diffusion and/or characteristics research. Shijiazhuang City, China was chosen precisely because it was an ideal place to study the kind of adoption and postadoption suggested above. A total number of 548 respondents (fathers and grandfathers) were randomly selected for a survey research from two generation families in Chang An District, Shijiazhuang City. This study shows that the earlier adopters do not have the highest degree of commitment to the media. The finding suggests that there are no grounds to ignore the postadoption for media characteristics research. This research also demonstrates that there is not even a generalized innovator within a product category (media). This finding not only enables us to reject the assumption that all innovations are equivalent units in a more specific level but also justifies the need for research, especially on subjective innovation characteristics. This research shows that the four media have to be classified by both sociological variables and personal values directly or indirectly. It is a surprise to find that television is characterized by achievement oriented values for the father generation in Shijiazhuang City. This suggests that television is perceived differently across societies. However, the findings on the telephone are consistent with the Western experience. That is, the telephone is either job- or business-related and is characterized by achievement-oriented values in its early stage of diffusion. Similarly, while the ACR is characterized by enjoyment oriented values, the pager is more identified by materialism oriented success. The subjective characteristics of media, however, can only be identified under certain conditions. It is found that not only the two generations perceive the four media differently but also the ability to pay, intergenerational mobility, education, and occupational prestige directly affect the adoption and post adoption to some degree.
Impact of intercellular adhesion on cell cycle and resistance to anticancer agents

Several studies have documented a correlation between cell-cell adhesion and resistance of tumor cells to anticancer agents. To assess directly the impact of intercellular adhesion on resistance of solid tumors, clonal variants of the mouse EMT/6 mammary carcinoma cell line were derived that formed tightly- or loosely-adherent aggregates in three-dimensional culture. As well, the enzyme hyaluronidase was found to disrupt aggregation of EMT/6 tightly-adherent variants. It was shown that tight intercellular adhesion, which correlated with reduced proliferation, was sufficient to confer resistance to anticancer agents which target rapidly dividing cells. Furthermore, the "anti-adhesive" hyaluronidase stimulated proliferation and sensitized tumor cells to anticancer agents both 'in vitro' and 'in vivo' in an ascites tumor model. An analysis of the effect of intercellular adhesion on cell cycle regulators was conducted to examine the hypothesis that adhesion-dependent drug resistance may have a kinetic basis. These studies revealed that the cyclin-dependent kinase inhibitor p27'Kip1' was upregulated by intercellular adhesion. Furthermore, depletion of p27 in EMT/6 cells increased cell proliferation and sensitized tumor cells to anticancer agents. These effects were observed in three-dimensional culture, but not in conventional monolayer culture. E-cadherin is a homophilic cell-cell adhesion molecule found ubiquitously on normal epithelial cells. To determine if E-cadherin could mediate contact-dependent growth inhibition of non-adherent EMT/6 cells which lack endogenous E-cadherin, these cells were transfected with an exogenous E-cadherin expression vector. Aggregation of EMT/6-E-cadherin transfectants resulted in reduced growth and elevated p27 levels. Exposure to anti-E-cadherin neutralizing antibodies abrogated adhesion, stimulated growth, and reduced p27 levels. Further studies support the idea that E-cadherin-dependent growth suppression is mediated, at least in part, by elevated levels of p27. The impact of cell adhesion on cancer has been studied almost exclusively in the context of tumor angiogenesis, invasion and metastasis. The studies reported here demonstrate that intercellular adhesion, through effects on p27, can also affect proliferation and resistance of solid tumors to anticancer agents. These studies suggest that tumor-targeted p27 antagonists or "anti-adhesives" may be useful chemosensitizers in conjunction with conventional anti-cancer therapy.
Identification of ATP-reactive sites in the bacteriophage lambda packaging enzyme, terminase

ATP-reactive sites in terminase and its subunits were successfully identified using three different affinity analogs of ATP, (2- and 8-azidoATP and FITC). GpA, the larger subunit of terminase was shown to have a higher affinity for these analogs than gpNu1, the smaller subunit. The suitability of these reagents as affinity analogs of ATP was demonstrated by ATP protection experiments and in vitro assays done with the modified proteins. These analogs were thus shown to modify the ATP reactive sites. The results obtained from these experiments also indicate the importance of subunit-subunit interactions in the holoenzyme. Terminase, gpA and gpNu1 were modified with these analogs and the ATP-reactive sites were identified by isolating the modified peptide by reverse phase chromatography. The sequence analysis of the modified peptides indicates a region including amino acid 18-35 in the N-terminus of gpNu1 and a region including amino acid 59-85 in the N-terminus of gpA as being the ATP reactive sites. A single 2-azido modified peptide, VGY*SK (amino acid 81-85) was isolated from terminase; the same region of gpA labeled by FITC and 8-azidoATP.
Making sense for our lives, women's collaborative reading of fiction

This inquiry examines some of the ways in which a woman reader's life choices and her sense of personal identity are changed by her reading of a novel. Each of three women, including the dissertation writer herself, wrote detailed narrative accounts of how one novel affected her life. These narratives are examined in the light of theories of reading, women's life writing, feminist theory, literature as philosophy, and feminist literary criticism. While each narrative tells a different story of reading, all demonstrate profound changes in the reader and her life which the authors attribute to the influence of the novel. In one of the cases, the formation of a kind of "friendship" with the chief character in the novel, and with the implied author of the work, plays a part. The second turns in revulsion from the chief character and reads the work as a dire warning for her life. The third makes two very different readings of her novel as a young woman, and as a woman of mature years. All these relationships are analysed, as is the nature of the knowledge a reader can gain from fiction. The inquiry recognizes that the influence of a novel may not be liberatory, and demonstrates that the social conditions in which a reading takes place affect the reader's understanding. In order for her reading to aid in the formation of a stronger sense of herself, and to life choices she likes better, a reader often needs a social climate and ancillary studies which support these changes, such as those provided by Women's Studies Programs. These findings suggest that, in addition to a study of fiction as art, readers should be encouraged to consider aspects of their lives in light of fictional characters, situations, and themes, and to incorporate these considerations into their discussions and writing about fiction. These practices are applicable in schools at all levels, as well as to informal groups, and private reading.
Luminescence quenching studies of oxygen diffusion in highly permeable media

Investigations on the nature of gas diffusivity in polymers are important not only to various industrial applications, but also to further our conceptual understanding of this ubiquitous process. In this thesis, I describe the application of a relatively new technique based on luminescence quenching to probe the nature of oxygen diffusion in a series of poly (alkyl(amino)thionylphosphazenes) (PTP) and high molecular weight PDMS, with varying Tg's ranging from $-$127 to 22$\sp\circ$ C. Experiments performed on thin films of these highly permeable media show that gas diffusivity exhibits strong dependence on the microstructure of these polymers. The two main types of experiments under consideration are steady-state time-scan experiments and pulsed excitation experiments. While steady-state measurements provide bulk-averaged values for diffusivity and permeability, pulsed laser experiments offer some insight into diffusivity on a microscopic scale. Attempts at the fitting of data to kinetic models reveal that the models applicable to quenching reactions in fluid media are incapable of rationalizing quenching in polymeric media.