McGill University Thèses et mémoires publiés en 2003

B6.YTIR sex-reversed mice with bilateral ovaries develop an apparently normal female phenotype, but their eggs fail to develop after fertilization. Our previous studies have shown that the primary cause of infertility in the XY female can be attributed to the incompetence of its oocytes for postfertilization development rather than their surrounding somatic cells. The objective of this study was to examine the segregation of chromosomes during two successive meiotic divisions in the oocytes from XY females and the oocytes from XX females as a control. Oocyte-cumulus complexes were collected from gonadotropin (PMSG)-primed ovaries and matured in culture. MII-oocytes after culture …  Lire la suite

As cities have evolved over history as a function of human behaviour, they represent the rich social laboratories of a particular civilization. Because of its ancient roots and its particular historical evolution, the urban tradition in China is appreciatively unique, but yet as China is rapidly thrust into modernity and post-modernity of global interdependence most evident in its urban centres, one can discern clearly the serious cultural disparities that threaten the social fabric of the Chinese people. It is through the massive development of its major metropolises that China is embarking on a disturbing trend of false development, a top-down …  Lire la suite

Cdk7 (Cyclin-dependent kinase 7) is conserved from yeast to human and involved in multiple functions. Cdk7 acts as a CAK (Cdk activating kinase) in a trimeric complex with Cyclin H and Mat1. The CAK activity is required for the full activation of the Cdks that directly regulate the cell cycle transitions. In addition, Cdk7 is the kinase subunit of TFIIH, the general transcription/DNA repair factor IIH. TFIIH is required for the general transcription of messenger RNAs by RNA polymerase II and for the transcription-coupled nucleotide excision repair functions. As in other systems, Drosophila Cdk7 has multiple functions. In order to …  Lire la suite

Protein tyrosine phosphatase 1B (PTP1B) is the prototype for the superfamily of protein tyrosine phosphatases, and has been implicated in multiple signaling pathways. Of particular interest, gene targeting studies in mice have established PTP1B as a critical physiological regulator of insulin signaling and PTP1B knockout mice are resistant to both diabetes and obesity. At the start of this thesis, the mechanism underlying the role of PTP1B in obesity was not completely understood. Furthermore, the importance of PTP1B in cellular and oncogenic signaling was not well established. My doctoral research has primarily been aimed at addressing these two broad questions. Using …  Lire la suite

Confidentiality is unanimously recognized to be one of the most characteristic and attractive features of international commercial arbitration. The confidential character of arbitral proceedings has often been presumed on the basis of the privacy of the hearings, but this presumption has proven ill-founded in arbitrations between private and public actors ("mixed arbitration"). National courts and international tribunals have come to recognize and to enforce a public interest exception to confidentiality based on the principle that the public has a right to be informed of the contents and outcome of the arbitral proceedings whenever the subject-matter of the dispute is of …  Lire la suite

Since 1998, school governing boards have been Quebec's answer to the trend towards school-based management. This study investigates the experiences of two parent representatives on a school governing board and a school board administrator in the early years of Quebec's effort to decentralize educational governance. The literature suggests that school-based management can be found in various degrees, but that it is not always successfully implemented. Obstacles related to school-based management include how school governing boards are composed, how their powers are defined, and the nature of their relationship with their school boards. Evidence from the three participants suggests that these …  Lire la suite

The giant Pascua Au-Ag-Cu high-sulphidation system is located in the El Indio belt in north-central Chile, and is hosted mainly by Triassic granitic rocks and locally by Miocene breccia bodies. Hydrothermal activity involved two distinct high-sulphidation alteration stages, the later of which was accompanied by main stage mineralization. The early hydrothermal activity consisted of extensive and pervasive advanced argillic alteration, local development of vuggy silica and distal argillic to propylitic alteration. This alteration was locally overprinted by an intermediate stage comprising argillic alteration, silicification and primary jarosite, more or less contemporaneously with the formation of Brecha Central, the main breccia …  Lire la suite

The subject of this thesis is synchronous master-slave database replication, failover and distributed recovery for a cluster of database servers. Our replication solution allows updates on the master, and queries on ail sites. Updates of transactions are sent to ail sites before they are committed on the master. To do this, we take advantage of the semantics of group communication Systems. With failover, there is always a master in the group. Distributed recovery ensures that a site that has been introduced in the System brings its own copy of the database to be consistent with the rest of the other …  Lire la suite

Numerical notation systems are structured, visual, and primarily non-phonetic systems for representing number. This study employs a diachronic and comparative framework to examine over 100 systems used during the past 5000 years. The historical context of each system's origin, transmission, transformation, and decline is traced, linking systems together into phylogenies, but according priority to neither analogical or homological explanations. Structural aspects of numerical notation systems are compared and the limits of variability among them are established. A two-dimensional typology is presented that analyzes the intraexponential and interexponential structuring of each system, in addition to one or more numerical bases. In …  Lire la suite

Tourniquet Mirage, a piece for orchestra and processed sound, is based on the recitation of a poem of the same name. Recitations are recorded and altered electronically through granulation and phase vocoding. Granular synthesis cuts audio up into "short sound grains" and combines them into a sequence of grains to form a longer final output. Phase vocoding uses Fourier analysis to analyze audio and represent it as a series of amplitudes, phases, and frequencies. The phase vocoder then uses this information to manipulate the audio without altering the overall structure of the waveform. The processed sound part is closely linked …  Lire la suite

Turner, C. E. (Supervisor)  Lire la suite

Resin Transfer Molding (RTM) is a procedure in composite material manufacturing in which resin and fibers are held apart until the last possible moment. In this way it can be contrasted with other manufacturing methods where the resin and fiber are combined prior to use. In RTM, unresinated fibers are held within a tool cavity and a differential pressure is applied to a supply of resin so that the resin flows into the reinforcement completely wetting it out. Reinforcements may be made of any fiber and the use of all forms has been reported, from unidirectional through woven or knitted …  Lire la suite

Partnership, the pre-eminent buzzword of the last two decades, is still very much the mantra in development cooperation discourse, at least in the North, as we begin the new millennium. This posthoc retrospective study is an insider's account of personal experience in participating and observing the development of Tanzania's Education Sector Development Program over a one-year period in 1998--1999. The study interrogates the workings of Donor-Government partnerships within this setting in an attempt to unravel the realities on the ground in their relationships and how the power asymmetry between these principal actors and their concomitant behaviour served to subvert the …  Lire la suite

This study uses life cycle analysis to examine the net greenhouse gas (GHG) emissions from the activities of the peat industry in Canada for the period 1990 to 2000. GHG accounting is undertaken for (1) land use change, (2) peat extraction and processing, (3) the transport of peat to market by truck, train and ship, and (4) the in situ decomposition of extracted peat. The emission estimates were based on results from GHG accounting models using data derived from scientific literature, government and industry statistics, and the responses to a questionnaire sent to Canada's peat establishments. The questionnaire, designed to …  Lire la suite

The utility of single-bounce attenuated total reflectance (SB-ATR) and heterospectral two-dimensional correlation spectroscopy (H2D-CS) in quantitative analysis by Fourier transform infrared (FTIR) spectroscopy was investigated by exploring several potential applications of these techniques. Enzymatic hydrolysis of lactose in milk was monitored by SB-ATR/FTIR spectroscopy, and changes in the concentrations of glucose, galactose and lactose during the process were successfully measured quantitatively. SB-ATR/FTIR spectroscopy was shown also to perform comparably to Fourier transform near-infrared (FT-NIR) spectroscopy for the determination of the alcohol content of distilled liquors and better than FT-NIR spectroscopy and comparably to transmission FTIR spectroscopy for the analysis of …  Lire la suite

The promoter system of agriculture extension has been widely studied and accepted as a tool for agriculture development where local resources are scarce. Much development work has been done in Panama using the promoter model. In order to ascertain the local success of this model, promoters trained by World Vision were visited. The adoption of sustainable agriculture practices were measured in five communities where 7 promoters were trained and placed in Veraguas, Panama. Despite the long-term presence of World Vision and trained promoters, only six farmers have adopted at least one sustainable agriculture technique as a result of these extension …  Lire la suite

Calls for innovations and research echo in the latest reviews and meta-analyses of methods to enhance compliance (Haynes, McDonald, Garg, & Montague, 2003; Pekkala & Merinder, 2002; Peterson, Takiya, & Finley, 2003). In spite of effective therapy emerging daily from medical research, non-compliance appears at disappointing rates. Over the past 25 years, the gap is widening between what we could achieve with available and emerging health care and what we are currently achieving. This lack of compliance with proven therapy thwarts health outcomes and adds to the growing health care costs. In Canada, direct and indirect costs resulting from non-compliance …  Lire la suite

Southern Africa is experiencing an HIV/AIDS pandemic with devastating effects. In this thesis I suggest why prevention efforts have failed to stem the pandemic. Then I argue that developed countries have a duty to help the developing world fight the HIV/AIDS pandemic. Arguments grounded in justice and in vulnerability are used to reach this conclusion. Next, I suggest that developed countries have not done enough to help. I develop and advocate the Socioecological Medicine Approach as a conceptual framework to help address the HIV/AIDS pandemic. This approach is a useful perspective because it is holistic, embraces web causation, emphasizes interconnectedness, …  Lire la suite

The communicative competence of bilingual children involves a large array of skills---they must not only acquire the full range of communication skills of monolinguals but also learn when, how and with whom to use each language. This dissertation features three studies on the communication skills of bilingual children (French-English bilinguals aged 2.5 and 3 years from the Montreal area). Studies 1 and 2 explored these children's ability to make appropriate language choices by studying their responsiveness to two types of cues: The first study investigated whether children's language choice is influenced by their interlocutor's code-mixing; the second study examined whether …  Lire la suite

In chapter one, I describe the different conceptions of self that Murdoch and Nussbaum have, and I show how these affect their depictions of human good. And I relate how each one defends the internal logic of her claims against the critique of moral relativism. I examine Iris Murdoch's conception of reality and consciousness in the distinctive way that she fuses them to a transcendent morality. In chapter two, I turn to Murdoch's description of the journey from illusion to reality and the role of love or eros in this journey. I examine the many points of intersection between her …  Lire la suite

This inquiry is a phenomenological exploration of the development of two student teachers undergoing their practicum experience in my secondary classroom. It examines the changes in identity that the student teachers underwent and how those changes came about. The goals motivating this inquiry were (1) to understand the process through which the transition from student teacher to teacher occurred, and (2) to understand what influence the people surrounding the student teachers, such as the cooperating teacher and the supervisor, had on the process. The analysis closely follows Wenger's (1998) work in Communities of Practice and Schon's (1983, 1987) work in …  Lire la suite

This dissertation explores the significance of law and religion to the Scottish Revolution through the career of Archibald Johnston of Wariston. As a lawyer committed to the defense of Scottish Presbyterianism against the Anglicanism of Charles I, Wariston epitomized the legal and religious objectives of the Revolution. While his importance to the Revolution is marked in the historiography, Wariston has received little specialized study. This work draws on manuscript collections from Edinburgh University Library, the National Archives of Scotland and the National Library of Scotland to reconstruct his vision of the Scottish constitution. As the most intimate source of his …  Lire la suite

A new method of drug discovery, the pseudo-dynamic combinatorial library, is described. The technique involves expanding on the dynamic combinatorial library method, where a reversible synthetic reaction is carried out in the presence of a target. In the pseudo-dynamic combinatorial library, this reversible reaction is separated into two irreversible steps. The independent control of the two steps leads to superior selectivity in the screening process. A model system based on peptidic inhibitors of carbonic anhydrase was developed and studied. The synthesis of a series of new carbonic anhydrase inhibitors is described. Amino acids with sulfonamide and sulfamide functional groups, which …  Lire la suite

Anne de France, or Anne de Beaujeu by marriage, was present in history books long before she was the subject of literary studies. Regent of France's kingdom during her brother's, Charles the VIII's, minority (1484--1491), we know her mostly for successfully having measured herself up to her political opponents by calling the Etats Generaux and ruling the kingdom with calculating tactfulness. However, she also leaves a literary legacy, her Enseignements, which she writes for her only daughter Susanne in 1504 or 1505, and which are published in 1521 in Lyon by the editor and bookseller Le Prince. Having not enjoyed …  Lire la suite

The 1994 CSA Standard requires that slab-column connections be designed for one-way shear and two-way shear action. Three full-scale slab and corner column specimens were constructed and tested to failure to investigate the influence of the size of corner column on the slab shear capacity. The current design provisions of the 1994 CSA Standard and EC2-02 were compared with the experimental results of the three specimens. The experimental results indicate that the predictions for one-way shear action are more accurate than the predictions for two-way shear action. The beneficial effects of increasing the column size in improving the shear capacity …  Lire la suite

Using a model system of glycosylated and aglycon standards consisting of rutin and quercetin respectively, and a series of pre-packed solid phase extraction cartridges, including C18 Extra-Clean, DSC-18, DPA-6S, Oasis HLB and Amberlite XAD-2. The experimental findings also showed that use of a commercial hesperinidase preparation, resulted in adequate hydrolysis of the glycosylated standard rutin. Based on these findings, the phenolic compounds and flavonoids from maple sap and syrup were separated using the Amberlite XAD-2 column, where the glycosylated fractions eluted with 60% aqueous methanol solution and the aglycon fractions eluted with a methanol:acetonitrile mixture (1:1, v/v). The recovered glycosylated …  Lire la suite

Despite its relative importance, "use" of the affected upper extremity (UE) following stroke has obtained very little attention. This can be explained in part by the fact that effective means of measuring "use" are not readily available to clinicians. The objective of this cross-sectional study was to examine whether measures of manual dexterity and UE function, commonly used by clinicians and researchers, can effectively gauge at-home "use" of the affected UE by patients who have suffered a stroke. Methods. Gross and fine manual dexterity, UE specific function, UE related independence, grip strength and endurance were evaluated on 47 chronic stroke …  Lire la suite

Lipochitooligosaccharides (LCOs) are molecules secreted by rhizobia during the establishment of rhizobia-legume N2-fixing symbiosis. Some recent reports have shown that there are physiological effects on host and non-host rhizobia after LCO treatment. However, the cellular mechanisms underlying these observations are not known. Therefore, the study was aimed at assessing phenotypic changes by measuring photosynthesis, leaf area and dry weight on a non-host plant (tobacco). Our results did not show any significant physiological changes following LCO treatment. We also wanted to explore the molecular basis of changes in the plant cell by looking at gene and protein profiling following LCO treatment …  Lire la suite

The carrot weevil, Listronotus oregonensis LeConte (Coleoptera: Curculionidae), is an important pest of carrot in northeastern North America. The objective of this study was to determine the host selection stimuli used by two L. oregonensis parasitoids: the adult parasitoid Microctonus hyperodae Loan and the egg parasitoid Anaphes victus Huber. In the first chapter, the response of M. hyperodae females to various odor components from potential hosts and host plants was tested with a Y-olfactometer. In the second chapter, the effect of L. oregonensis adult sex, feces and movement on host selection behavior of M. hyperodae females was evaluated by quantifying …  Lire la suite

A system is implemented that optimizes two-dimensional magnetostatic devices. The system uses Sensitivity Analysis to obtain a gradient with respect to a set of design parameters, using the Adjoint Variable Method to reduce computation time. An analysis of the time complexity of the system shows its efficiency compared to other optimization methods. The system is tested on several problems including the TEAM 25 benchmark problem.  Lire la suite

A decision support framework (DSF) to guide watershed management planning in St. Lucia was developed. The DSF, supported by three components, integrated physiographic criteria in spatially defining sustainable land management regimes, crop suitability based on agro-ecologic zoning criteria, and water quality modelling tools. In the first component, a methodology for agricultural and forestry land management zoning based on decision-rule frameworks was developed, employing GIS-based spatial multiple-criteria integration techniques. Land capability, recommended land management regimes, crop suitability and broad agricultural/forestry land utilization type zones were derived for the country. Sixteen broad agricultural and forestry land utilization types (LUTs) based on FAO …  Lire la suite

The brain isoform of the vesicular monoamine transporter (VMAT2) packages monoamines into synaptic vesicles (SVs), an essential step in synaptic transmission by central dopamine (DA) neurons. While the modulation of VMAT2 levels influences the amount of DA that can be released, the underlying mechanisms remain unclear. The objective of the present study is to elucidate these mechanisms by examining the SVs of VMAT2 knock out (KO) mice. We used transmission electron microscopy to determine that DA terminals from VMAT2 KO and wild type samples are morphologically indistinguishable from one another. We then monitored the uptake and release of the activity …  Lire la suite

In this ethnographic inquiry, I examine how a selected group of Chinese immigrant children in Montreal, Quebec negotiate literacy practices in three languages, Chinese, English and French. I collected data between 1998--2002 through participant observations in different socio-cultural-linguistic contexts that include a Chinese Heritage Language school and the students' home domains. Data sources also include interviews, classroom discourses, field-notes and the students' written texts in the three languages. I draw on Vygotskian socio-cultural theory as an overarching framework to conceptualize my understanding of Chinese immigrant children's triliterate actions. I use Wertsch's concept of "mediational means", Bakhtin's notions of "utterance, voice, …  Lire la suite

Kuki Shuzo was a philosopher at the margins of the Kyoto School; his most significant contribution was the short work 'Iki' no kozo, in which he located Japanese uniqueness in the Edo demimonde aesthetic of iki, style or chic. This thesis surveys the major Western critiques of Kuki's aesthetics, focussing particularly on the work done by Peter Dale, Leslie Pincus, and Harry Harootunian revealing Kuki's borrowing from European modernism, especially fascist modernism, and attempts to uncover an alternative genealogy for Kuki in Japanese Pure Land thought. It finally asserts that Kuki's valorization of resignation, and his own retreat into the …  Lire la suite

Reduced access to atmospheric oxygen greatly increased early instar Aedes aegypti mortality. Data suggest that death was by drowning mainly because slow swimming speed and low visual acuity delayed larvae from finding access to air. Late instar larvae experienced developmental delays when food depletion in the immediate vicinity of the breathing site forced them to forage farther away. As the distance between feeding and breathing sites increased, feeding efficiency of fourth instars may have declined enough to reduce their pupation success and to cause increased pupal mortality, reduced adult emergence and sex ratio skewed in favour of males among emerging …  Lire la suite

Containment structures for aircraft engines must withstand impacts of failed engine components, which may be traveling at extremely high velocities. Therefore, the design of such structures requires a thorough knowledge of material behaviour at high rates of deformation. It is well known that at strain rates above 102 s-1, the yield stress of metals may be significantly different than at quasi-static rates. In addition, material fracture under dynamic loading can also differ from that at slower rates due to manifestation of different failure mechanisms. The purpose of this study was to gain an understanding and determine the constitutive behaviour and …  Lire la suite

In recent years, heated debates about the definition and evolutionary role of simple, egalitarian hunter-gatherer societies have assumed a central place in hunter-gatherer studies. Since household dynamics are bound to be fundamental in arguments about these issues, the present study examines social change in terms of household integration in Air Bah, a resettlement village of newly sedentary Lanoh hunter-gatherers and forest collectors of Peninsular Malaysia. The Lanoh have accepted inequality more readily than cooperation and binding relationships. Household integration has remained partial because, even in households of self-aggrandizers, younger men retain their individual autonomy. This incomplete household integration, in turn, …  Lire la suite

A two year study was initiated in 2001 on a 2.4 ha site of mostly St. Amable loamy sand and shallow loamy sand at the Macdonald Campus Research Farm. This study sought to assess the effects of long term tillage and residue practices on soil physical properties and to relate these properties to their influence on total carbon, total nitrogen and soil microbial biomass-carbon. The site was set up as a factorial experiment with three tillage practices (no till---NT; reduced till---RT; and conventional till---CT) and two residue practices (with residue (grain corn), +R; without residue (silage corn), -R). Soil physical …  Lire la suite

A quantification of local energy dispersion is employed to distinguish cases of downstream baroclinic development, as described by Orlanski and Sheldon, from among 41 cold-season cyclones that intensified strongly over the eastern North Pacific Ocean. Complete summaries of the eddy energy budget are calculated for each event, and about half are found to be in general accord with the proposed evolution. Almost all of this subset appear to have been influenced by a dispersion of energy from separate cyclones developing over the western North Pacific a day or two earlier. The primary source for eddy energy dispersion downstream and subsequent …  Lire la suite

Precup, Doina (Supervisor)  Lire la suite

The influence of energy restriction on the transmission dynamics of a direct life cycle nematode, Heligmosomoides polygyrus, within free-running arena Systems has to date remained unexplored. Indoor populations of CD-1 outbred mice were established for 12 weeks in arenas and fed either energy-suffi ci ent (ES) or energy-restricted (ER-20% réduction in metabolizable energy) diets. Infection was introduced to ail arenas following 3 weeks of diet treatment. Contrary to previous findings, the mice fed the ER diets compensated for the deficiency by increasing food consumption and thus, while early in the experiment energy restriction was evident, dietary effects were no longer …  Lire la suite

The main purpose of this study is to present a detailed description of the interaction between students and teacher, focusing on which literary elements kindergarteners learning English as a Foreign Language (EFL) respond to during the story-reading sessions. Two teachers and a total of 101 kindergarteners from a private kindergarten located in Taipei, the capital city of Taiwan, were chosen for this study. Both qualitative and quantitative data were gathered in the form of classroom observations and student and teacher interviews. This analysis revealed that format was the literary element that students responded to the most. However, factors such as …  Lire la suite

The purpose of the current study was to investigate factors affecting the job satisfaction of Canadian male university basketball coaches, as it pertained to their goals and measures of success for themselves, their athletes, and their team. Semi-structured individual interviews were conducted with six university coaches. Three higher-order categories emerged: (a) personal variables, which encompassed the philosophies the participants developed based on their athletic and coaching experiences, (b) internal elements, which involved what the coaches did for their athletes' academic, athletic, and personal development and the coaches' personal development, and (c) external influences, which included tangible and measurable positive and …  Lire la suite

Pavlasek, T. (Supervisor)  Lire la suite

According to Domowitz (1992), the Agni women of Cote d'Ivoire assign proverbs and aphorisms as names to wax-dyed cloth. Women then use the imagery and associated proverbs behind cloth names to send non-verbal messages they would otherwise be unable to express publicly. The purpose of this study is twofold: first, to investigate wax-dyed cloth names including their underlying meanings and uses given by women in Cote d'Ivoire and Togo; and second, to investigate how these names are acquired in French by women who have no formal education. Qualitative results revealed that women in these two countries are very motivated to …  Lire la suite

A new thermoluminescence dosimetry system for environmental applications was tested, which used high sensitivity lithium fluoride (TLD-100H). The energy response of the bare thermoluminescence dosimeters (TLDs) was measured for photon beams with mean energies from 24 keV to 1.1 MeV, and the results were compared with standard lithium fluoride (TLD-100). The energy response was also measured for TLD-100H card-mounted dosimeters encapsulated in Teflon RTM, used as part of the Harshaw Type 8855 environmental dosimeter. The EGSnrc Monte Carlo system was used to calculate the dose to the TLDs in both the bare chip holder and the 8855 dosimeter, in order …  Lire la suite

A continuous flow of information has to be maintained between cells in order for them to elicit a concerted response to changes in their environment. For that purpose, the cells partly rely on polypeptide growth factors that interact with specific receptors at the cell surface. Among these growth factors, TGF-beta has been implicated in a great variety of cellular processes including growth inhibition, apoptosis, extracellular matrix production and epithelial to mesenchymal transition. TGF-beta signaling is mediated through ligand binding to the ectodomains (ED) of three types of receptors, T-beta-RI, T-beta-RII and T-beta-RIII. LAP, the remnant part of the TGF-beta precursor, …  Lire la suite

Mesial temporal lobe epilepsy is a neurological disorder that is associated with neuronal death in the hippocampus and in parahippocampal structures such as the entorhinal and perirhinal cortices. However, clinical and experimental investigations regarding the function and the contribution of the perirhinal cortex in epileptogenesis are as yet limited. To determine the network interactions of the perirhinal cortex and the entorhinal cortex in ictogenesis, my investigations were conducted in the combined hippocampus-entorhinal-perirhinal slice preparation. Sliced were superfused with either 4-aminopyridine or Mg2+-free artificial cerebrospinal fluid to generate in vitro epileptiform activity. In these experiments I demonstrated alternating sites of initiation …  Lire la suite

We hypothesized that if normal cells carry a regulator which is inactivated in cancer cells, the transfer of this regulator from a normal cell to a cancerous one should inactivate the telomerase. Available in the laboratory was a panel of mouse/human microcell hybrids, each containing a tagged normal human chromosome fragment integrated into a mouse melanoma (telomerase-positive) background. We screened these hybrids for telomerase activity using both the polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay and mTERT mRNA amplification. We were able to find a telomerase negative microcell hybrid, B78MC27. Following multiple passages in culture most of …  Lire la suite

In the middle of the 1990's, Dr Jaw Ming Cherng, a previous student in the laboratory discovered the presence of an RNA molecule whose 5' end lies in the core origin of polyomavirus. This RNA molecule was transcribed in the same orientation as the late transcripts of polyomavirus and was named ori RNA. The ori RNA was detected by run-on transcription. In this technique, the viral transcription complexes---the DNA molecule and the RNA polymerases bound to it---are isolated from nuclei of virus infected cells and the nascent transcripts are extended in vitro with radioactive nucleotides. The RNA transcripts of a …  Lire la suite