McGill University Thèses et mémoires publiés en 2005

Many western societies place great emphasis on doctor-patient communication as an integral part of health care for patients. However, no substantial research has hitherto been done on doctor-patient communication in Jamaica. Such research is invaluable as cultural expectations may influence medical care and communication, and paradigms of doctor-patient communication in western, industrialized countries may not be generalizable to less industrialized countries like Jamaica. My research therefore sought to ascertain what factors affect the quality of doctor-patient communication in government hospitals in Jamaica, why, and how. A quantitative survey was done to gather the required data to ascertain what patients and …  Lire la suite

This thesis studies the relations between media image, online news design, and the framing of identity. It scrutinizes current images of Arab identity and their representation in Aljazeera Net in order to examine how Aljazeera Net constructs the 'reality' of Arabs. The dissertation begins by defining Arabness in terms of ethnic, cultural and postcolonial identities. It proposes and assesses the sources of Arab identity and examines Arab identity as a source of meanings for Arabs. Likewise, it evaluates the sources of Arab identity in the Arab diaspora. Through the lens of a remediation approach, the study explores newly emerging practices …  Lire la suite

Three studies were conducted to determine the effects of nonstructural carbohydrate (NSC) sources on performance of dairy cows fed sunflower seeds. In the first study, the effects of NSC source on dry matter (DM) intake, milk yield and milk fatty acid composition were evaluated using fifteen lactating Holstein cows in a 3 x 3 Latin square design. In the second study, fifteen lactating Holstein cows were used in a completely randomized design to determine the effects of NSC on the total tract nutrient utilization. The third study was designed to determine in situ ruminal degradability of DM, CP, NDF and …  Lire la suite

This thesis presents the design and experimental results of a 7.3GHz notch image reject filter, combined with a 5.8GHz low-noise amplifier (LNA), for integrated heterodyne receiver front-ends. A new image reject filter implementation is proposed. Q-enhancement circuitry for on-chip inductors are used to optimize the depth of image rejection. Experimental results show that more than 62dB of image rejection at 7.3GHz can be obtained in a standard CMOS 0.18mum technology, while operating from a 1.8V supply. The LNA exhibits a gain of 15.8dB and an IIP3 of -5.3dBm while consuming 9mW of power. With maximum image rejection, the LNA-notch combination …  Lire la suite

We study the problem of externally guarding or inspecting a polygonal environment with a mobile guard (watchman) in both unlimited and limited visibility models. A survey of the literature on guarding problems is presented for both stationary and mobile guards, as well as for both interior and exterior workspaces. Our research concentrates on the external inspection of a single, convex or simple, polygon. In particular, we study the relationship between the interior angles of convex polygons and the length of an external inspection route under unlimited visibility. We then propose a method for computing the shortest external inspection route for …  Lire la suite

The generalized least squares (GLS) method for phylogenetic inference assumes that errors in observed distances have an approximately Gaussian distribution. GLS has not been widely used nor properly evaluated because of computational difficulties. We examine issues relating to the implementation of GLS. Different estimates for the covariance matrix are examined. We found that the matrix is often ill-conditioned. Methods for solving the ill-conditioned unconstrained least squares problem are compared in terms of stability and efficiency. We conclude that the normal equations method, with a modified covariance matrix, performs best. Versions of the nonnegative constrained GLS method are discussed, implemented, and …  Lire la suite

Aviation and the internet are two conveniences without which the modern world would almost grind to a halt given our current dependence levels (on them). If both were to suddenly vanish, mankind would be thrown back to the late 19th century reminiscent of a world which was once a smaller place. Aviation plays a critical role in our daily life transporting man and material over vast distances in a relatively short period of time. A vital cog in this wheel is the airport that 'facilitates' the safe loading, unloading, take-off and landing of aircraft. For some time now, aircraft have …  Lire la suite

A cross-sectional survey was carried out to evaluate the nutritional correlates of growth in 93 HIV-infected children in the early and middle stages of infection. Also, as zinc is important for growth and immune function, foods commonly eaten by these children were evaluated for zinc content. Foods with relatively high zinc were identified in Uganda, and these food items were legumes and cereals. A high prevalence of stunting and wasting was found in HIV-infected children. The study also found that the frequency of past week oil/fat and staples consumption was non-significantly correlated to weight-for-height at the early stage, while household …  Lire la suite

The core of this research project revolves around the development of knowledge and expertise in the field of sequence homology identification techniques, as applied towards the discovery of Bcl2 family members. The use of such methods resulted in the uncovering of a Bcl2 Homology 3 (BH3) domain in a ubiquitin ligase enzyme known as upstream regulatory binding protein 1 (UreB1). A complete biochemical analysis unequivocally demonstrated binding of the UreB1 BH3 domain to MCL-1, an antiapoptotic member of the Bcl2 protein family. Furthermore, the discovery of a BH3 domain in UreB1 may provide a link in the established involvement of …  Lire la suite

Balbuzard is a musical composition of approximately twelve minutes in length, scored for solo clarinet, wind symphony and electronics. It focuses on cluster-like sound masses and explores ways of using these to give the music a clear sense of direction. To this end, tools were developed using a variety of computer applications or programming languages, such as Lisp, OpenMusic and Cubase. These tools made possible a kind of graphic composition where diagrams of different shapes were entered into a computer interface and converted into source material. The generated source material consisted of several rhythmic strata whose pitches, mainly part of …  Lire la suite

In a prevalent cohort study with follow-up, the incidence process is not directly observed since only the onset times of prevalent cases can be ascertained. Several important consequences follow if one can establish stationarity of the incidence process: (1) The useful epidemiological relationship between prevalence, incidence, and mean duration holds, (2) There is improved efficiency when estimating the underlying survivor function from a prevalent cohort study with follow-up, (3) The constancy of the incidence rate is established, and (4) The constant incidence rate can be estimated using data from a prevalent cohort study. We propose a formal test for stationarity …  Lire la suite

The Biomarkers of Cervical Cancer Risk (BCCR) case-control study was designed to address the role of human leukocyte antigen (HLA) alleles as cofactors in the development of high-grade cervical intraepithelial neoplasia (HG-CIN). Cases were women with histologically-confirmed HG-CIN attending colposcopy clinics and controls were women from outpatient clinics with normal cytological screening smears. Cervical specimens were submitted for both human papilloma virus (HPV) testing and HLA genotyping. Risk ratios were generated using logistic regression modelling. This analysis includes 381 case and 884 control subjects, mainly of French-Canadian descent. The B7-DRB1*1501-DQB1*0602 haplotype was associated with a 41 % reduction in risk …  Lire la suite

In this thesis, a study was undertaken on the premise that the world population living in urban centers is expected to increase from 3.8 billion to 5.2 billion, from 2005 to 2025, representing 54% and 65% of total world population, respectively. The urban population (UP) growth will produce remarkable amounts of urban food waste (UFW) that will add more pressure on already overloaded municipal solid waste (MSW) management systems of cities. This problem is more serious in countries experiencing major economic growth such as China where UP is expected to increase from 44% to 66% of the total country population, …  Lire la suite

Despite being abundant in the earth's crust, the concentration of Fe in many oceanic regions is so low that it is limiting to the growth of photosynthetic plankton. Heterotrophic bacteria play key roles in the oceanic cycling of carbon and nutrients, but it is unclear whether they can be Fe-deficient in nature, or what possible effects Fe-deficiency might have on their ecology and physiology. In chapter 1, I investigated the response of a natural bacterial community to a mesoscale Fe-enrichment experiment in the northeast subarctic Pacific. The addition of Fe to surface waters caused a rapid stimulation of bacterial growth …  Lire la suite

As Canada, and particularly metropolitan cities like Montreal, becomes increasingly diverse, it is important to explore and understand the culture and needs of immigrant communities. This Masters thesis focuses on the mental health of South Asian immigrant women in Montreal, Quebec. This original research is a qualitative descriptive study based on in-depth interviews with nine women from India and Pakistan. The interviews focus on the intersection of gender and culture with post-migration experiences, help-seeking patterns and coping strategies for distress in South Asian women. The women's narratives provide pertinent information for researchers and practitioners that could be applicable to the …  Lire la suite

We review the lore of effective field theories as a background to hierarchy problems in general and the cosmological constant problem in particular. We outline some of the attempted four-dimensional solutions to the cosmological con stant problem and conclude that ones based upon the usual assumptions of four-dimensiona lfield theory typically do not work. We argue that one way to relax the assumptions is to seek solutions to the cosmological constant problem which rely on the presence of extra dimensions. We explicitly exhibit that standard compactification techniques fail to solve the cosmological constant problem because they reduce the problem to …  Lire la suite

The main goal of this dissertation is to explore the hypothesis that persistent sodium currents may mediate epileptogenicity within the entorhinal cortex. The thesis attempts to answer three major questions: First, it asks whether persistent sodium currents regulate intrinsic excitability of entorhinal cortical layer V, which has been demonstrated to exhibit epileptogenic characteristics. Second, it asks whether persistent sodium currents may be up-regulated in an acquired temporal lobe epilepsy rodent model (lithium-pilocarpine), whose features strongly correlate with human temporal lobe epilepsy. Third, it asks whether persistent sodium currents may be up-regulated in a genetic epilepsy model, which overexpresses a mutation …  Lire la suite

The numerical analysis of electromagnetic devices can generate large volumes of data describing the performance of the device. To date, this information has been provided to the user either as sets of numeric data or in graphical form. However, modern personal computers are actually capable of producing other forms of output such as sound. Although an essential component in computer gaming, sound has not been explored in any depth in scientific results evaluation. This thesis describes the implementation of software designed to investigate outputting data obtained from the simulation of an electromagnetic system in the form of sound using readily …  Lire la suite

This thesis aims to build the groundwork for a distributed network of collaborating, intelligent video surveillance cameras. This work is implemented on a system of low-cost embedded-microprocessor-based camera modules. Each camera develops a person detection classifier using the Winnow algorithm for unsupervised, online learning. Training examples are automatically extracted and labelled from the current frame, and the classifier is then applied to the image to detect and locate person instances. To improve detection accuracy, multiple cameras with overlapping fields of view collaborate to confirm their results. We present a novel, unsupervised calibration technique that allows each camera module to understand …  Lire la suite

An 1 out of 2 Oblivious Transfer (( 21 )-OT) is a two-party computation in which a sender A owning two secret bits b0, b 1 can transfer one to them, bc, to receiver Bob who chooses c. This is done in such a way that Alice does not learn anything about c and Bob does not learn anything other than bit bc. Security specifications for ( 21 )-OT are defined in terms of privacy and correctness. Privacy constraint enforces that B gets the bit of his choice and gains no knowledge about the other input bit of A , …  Lire la suite

A major limitation to the success of islet cell transplantation as a therapy for type I diabetes is the cell loss induced by the islet isolation procedure. The aim of this thesis was to elucidate signal transduction events and related intracellular activities that are implicated in islet cell survival/death following islet isolation in order to develop therapeutic interventions to promote islet survival. The isolation of pancreatic islets imposes considerable stress on these cells, resulting in significant levels of cell death following isolation which was associated with activation of the stress-activated c-jun NH2-terminal kinase (JNK). However, within 24 hours in culture, …  Lire la suite

Allyl propargyl ethers undergo cobalt-mediated cycloisomerization reactions to form dihydrofurans in good yield and with excellent diastereoselectivity. The reaction is proposed to proceed by way of an allylic C-H activation and a formal 5-endo-dig cyclization. The reaction works with a range of allylpropargyl ether substrates. 1,6-Enynes and allyl propargyl ethers undergo a cobalt-catalyzed formal 5-endo-dig cyclization to form vinyl cyclopentenes and dihydrofurans, respectively. The use of equimolar amounts of dicobalt octacarbonyl and trimethyl phosphite affords optimum yields and improved selectivity for cycloisomerization vs. alkene isomerization. The utility of the cycloisomerization reaction is exemplified through the synthesis of the bis-tetrahydrofuran core …  Lire la suite

Animal models are valuable tools in auditory research. Rats are potentially very useful for this purpose. They are low in cost, they are genetically similar to humans, and the middle-ear structures are easily approachable. The goal of the present study is to better characterize the mechanics of the rat middle ear by measuring frequency responses at multiple points on the tympanic membrane for the first time, and with better frequency resolution than in previous studies. A laser Doppler vibrometer was used to measure the vibrations. Measurements were done on seven rats. Tympanic membrane vibrations at seven different points, in the …  Lire la suite

This dissertation seeks to contribute to our understanding of the role played by civilian leaders in the consolidation of democracy examining changes in levels of military influence over politics. This study departs from typical military-centric civil-military relations literature by employing a civilian-centric analysis. In particular, it shows how the former's focus on changing levels of internal threat cannot account for variations in the levels of civilian control over the military. The study instead adopts a framework that focuses on the incentive structure of civilian leaders as determined by competitive elections; the political capacity of leaders as reflected in their parliamentary …  Lire la suite

Three new quantitative Fourier transform infrared (FTIR) spectroscopic methods were developed for the analysis of edible oils: two procedures to measure free fatty acids (FFA) and one to measure moisture (H2O), the latter two methods ultimately being automated and implemented on an auto-sampler equipped FTIR spectrometer. The methods developed for FFA determination both convert FFAs to their carboxylate salts by means of acid/base reaction without causing oil saponification, one approach using 1-propanol, an oil-miscible solvent, and the other using methanol, an oil-immiscible solvent into which the FFA salts are extracted. The first method involves splitting oil samples into two halves, …  Lire la suite

Objectives. (1) To Determine the presence of HPV 6, 11, 16, 18, 31, 33, 35, 52b, 58 subtypes in resected oral/oropharyngeal SCCA cancer and associated lymph nodes. (2) To Determine if a relationship exists between koilocytosis, tumor grade, stage, or prognosis. Methods. Retrospective analysis and pathology review of patients with SCCA of the oral cavity at McGill in the last 5 years was performed. Age at diagnosis, risk factors, tumor stage, grade, koilocytosis, treatment, outcome, and presence of HPV by PCR were analysed. Results. 199 patients included were included in the analyses; 5 years mortality was 18.5%. 146 cases reviewed …  Lire la suite

The PMT (Protein O-mannosyl transferase) family members are involved in the initial step of protein-O-mannosylation. A large scale procedure (Systematic Genetic Array) was performed using pmt1, pmt2, pmt3, pmt5, and pmt6 as query deletions and a set of 4700 non-essential array gene deletions, to screen for query/array double deletion mutant combinations affecting growth of Saccharomyces cerevisiae. This procedure revealed a genetic interaction network consisting of 53 interacting genes. Functional grouping of these 53 genes revealed 9 functional categories that were analyzed according to gene function to elucidate how they might buffer defects in protein-O-mannosylation. Synthetic genetic interactions were also identified …  Lire la suite

The goal of pandemic influenza planning is to minimize health and economic losses in the event of a future pandemic. One of the numerous challenges associated with this goal is the need to ration limited medical supplies such as vaccines and antivirals. This thesis seeks to formulate an ethical framework for priority access to these resources. Prioritization strategies must be consistent with the goal of pandemic planning and should reflect societal norms for equitable distribution. According to an ethics framework based on the principles of utility and equity, three groups were granted highest priority for influenza vaccine, namely health care …  Lire la suite

We review basic concepts of the algebraic theory of combinatorial group theory, and try to emphasize the important role of groups represented with a set of generators and one defining relation.  Lire la suite

On 31 November 2003 the 1999 Montreal Convention for the Unification of Certain Rules for International Carriage by Air entered into force. Its purpose was to consolidate and modernize the Warsaw system and to reunify the provisions of several international instruments of private international air law under one legal instrument. The Montreal Convention consolidates the positive elements of the Warsaw Convention, the Hague Protocol, the Guadalajara Convention, the Guatemala City Protocol and Additional Protocol Numbers 3 and 4. It also simplifies and modernizes the requirements of documentation relating to the carriage by air of passengers, baggage and cargo. Most importantly, …  Lire la suite

An important number of Canadian dairy farms manage their manure as solids and in doing so, must handle large volumes of manure seepages and milk house wastewater (dairy farm effluent-DFE). The present project adapted surface irrigation as a more economical and sustainable method of disposing of this large volume of DFE on cropped land near their storage facility. The experimental surface irrigation system consisted of a gated pipe installed perpendicular to the slope of the field allowing the discharged DFE to run down the slope. The adaptation of the system and the measurement of its environmental impact were conducted on …  Lire la suite

Tandem coding and decoding has been demonstrated to yield arbitrarily low error rates provided a sufficiently large block length is used. When applied to practical systems that are inherently limited to a finite complexity and therefore to finite block lengths, such a strategy may be largely suboptimal. Indeed, a tandem decoding strategy ignores two types of information: the source memory and the residual redundancy of the source coder. Moreover, conventional source decoders, within a tandem decoding strategy, are designed to perform the inverse operation of the source coder and may severely decrease performance if errors are still present at their …  Lire la suite

The kidney filters blood through nephrons, to recycle water and solutes in order to maintain homeostasis in the body. A reduction in nephron formation during fetal development renders the affected individual susceptible to hypertension and end stage renal disease. Nephrogenesis relies on the iterative branching of the ureteric bud epithelium, which triggers the metanephric mesenchyme to condense and form nephrons at its tips. A critical question during kidney development is to identify the genes that are responsible for nephron formation. The culture of mouse embryonic kidneys has been an important in vitro model to examine the effects of candidate genes …  Lire la suite

Introduction. Total hip arthroplasty (THA) has been well documented to enhance patient function, but patient outcome is dependent on preoperative status. The exact timing of surgery to optimize patient outcome after THA remains unknown. This study determines the ideal timing for surgery to obtain the best possible functional outcome. Methods. Prospective, multicenter, cohort studies of 175 hybrid THAs. General health (SF-36) and disease specific (WOMAC and Harris Hip Score (HHS)) questionnaires were used to determine preoperative and 2 year final outcomes. Student's t-test, 95% confidence intervals, receiver operator characteristic curves, simple regression analysis and probability were measured. Results. All functional …  Lire la suite

Although mRNAs encoding the histone proteins are among the most abundant mRNAs in mammalian oocytes, the mechanism regulating their translation in these cells has not been identified. Most histone mRNAs are not polyadenylated but instead carry in their 3'-utr a highly conserved stem-loop structure. In somatic cells, the stem-loop binding protein (SLBP) is expressed during S-phase of the cell cycle and associates with the stem-loop of histone mRNAs promoting their processing and translation and thereby coordinating their expression to DNA replication. As histone mRNAs are abundant in immature oocytes which are in G2 of the cell cycle and in ovulated …  Lire la suite

Thermal conductivity is a powerful tool to probe the phonon and electron exitations in a solid, especially in superconductors were one can basically tune the respective electronic and phononic contributions by applying a magnetic field below Tc. After a short review on the concepts of superconductivity, thermal conductivity and amorphous matter, we present a study of the thermal conductivity of an exotic material, the amorphous metallic superconductor Fe0.5Ni 0.5Zr2. The results indicate an unexpected dominant electonic contribution to the thermal conductivity across the superconducting transition, in accordance with an inhomogeneous sample composed of a bulk normal phase with inhomogeneous superconducting …  Lire la suite

This thesis contains new results on the subject of polygonal structure reconfiguration. Specifically, the types of structures considered here are polygons, polygonal chains, triangulations, and polyhedral surfaces. A sequence of vertices (points), successively joined by straight edges, is a polygonal chain. If the sequence is cyclic, then the object is a polygon. A planar triangulation is a set of vertices with a, maximal number of non-crossing straight edges joining them. A polyhedral surface is a three-dimensional structure consisting of flat polygonal faces that are joined by common edges. For each of these structures there exist several methods of reconfiguration. Any …  Lire la suite

There is tremendous enthusiasm for the utilization of angiogenesis as a therapeutic modality for atherosclerotic arterial disease. Augmentation of physiological neo-vascularization in cardiovascular disease can be achieved through different pathways. Marrow stromal cells may serve as an ideal cellular vehicle for the in vivo delivery of therapeutic proteins or production of these proteins by the cells themselves. The use of autologous marrow stromal cells is highly desirable since marrow stromal cells are abundant and available in all human of all ages and they are easy to harvest and reimplant without the fear of rejection. Our primary data showed that marrow …  Lire la suite

Locker, David (Supervisor)  Lire la suite

Oocyte loss and meiotic prophase progression was studied in XY sex-reversed and XO female mice, two mouse models that lack pairing between their sex chromosomes. An arrest at the pachytene stage of meiosis was not observed, nor was a significant loss of oocytes at this stage compared to normal XX control mice. Thus, it was concluded that a pairing checkpoint either does not exist in oocytes or is not as stringent as the one observed in males. The effect of mutating the pro-apoptotic Bax molecule was studied at three distinct ages corresponding to the time when female germ cells are …  Lire la suite

Pulsed Electric Field (PEF) processing, a novel, non-thermal food preservation method, has been shown to inactivate both spoilage and pathogenic microorganisms, while minimizing changes in the physical and organoleptic qualities of the food, such as those observed under conventional thermal processing. An understanding of the inactivation mechanisms and kinetics of microorganisms exposed to lethal or sub-lethal PEF treatments would allow industry and consumers to better understand and evaluate the potential of PEF technology as an alternative or complement to traditional methods of food preservation. This study consisted of three sets of experiments which sought to determine: (i) the electrical conductivity …  Lire la suite

Due to their high specific strength and stiffness, honeycomb sandwich structures are used in impact-resistance applications. Their structural efficiency depends to a great extent on the lightweight core separating the face sheets and providing overall high stiffness. Detailed finite element modeling of the penetration of honeycombs by a projectile can be fairly complex, and computationally expensive as shown in the first part of this study. A computationally efficient axisymmetric equivalent numerical homogeneous model for Aluminum 5052-1119 1/8in - 0.001in hexagonal honeycomb subjected to high speed impacts in the range of 60 m/s to 140 m/s is then developed. An equation-of-state …  Lire la suite

The importance of hypertension as a risk factor for the development of AF is well recognized. Despite this leading importance, the role of essential hypertension in providing a substrate for AF is incompletely understood. The present study was undertaken to investigate the possibility of having rats as an adequate animal model for the relationship between hypertension and AF in man and to elucidate the role of hypertension as a risk factor for AF. The results of this study show that structural remodeling especially in the form of increased amount of interstitial fibrosis seems to be the major contributing factor to …  Lire la suite

It is generally accepted that spirituality can play an important role in the end stage of the life of a person. Spirituality can provide a source of comfort and guidance and in so doing be a coping strategy. Social workers should take into account this spiritual component of their work particularly with clients who use spirituality as a form of social support. This thesis provides a theoretical understanding of spiritual based practice. It identifies the principles and competencies central to this practice, including the need for worker self awareness. It then illustrates how certain social work students have applied these …  Lire la suite

A central tenet of democratic theory is that the exercise of governance be both legitimate and accountable. Elections constitute the fundamental means through which these ends are met. Critical to this process is the ability of the citizen to correctly assign responsibility for government action. Institutional arrangements are central to defining the pathways of accountability. In institutional contexts with only one level of government, assigning responsibility is relatively straightforward. However, in situations of multiple and overlapping levels of government, the process of correctly assigning responsibility and ultimately holding governments accountable for their actions is much more difficult. In comparative contexts, …  Lire la suite

Innovative means and methods were tested to develop an economical, pragmatic and environmentally sustainable soil remediation process for heavy metal contaminated soils. An unsaturated-flow soil washing procedure was devised to dissolve the soil-bound toxic heavy metals; the latter were extracted by a chemical washing solution that percolated through the soil matrix. Subsequently, the leached toxic heavy metals were selectively concentrated, by a chemical precipitation process, into a solid waste. Thereby, a fraction of the spent ethylenediaminetetraacetic acid (EDTA), within the washing and rinsing leachate, was theoretically regenerated and recycle-ready. The unsaturated-flow washing procedure was perfected by applying different treatments to …  Lire la suite

Although an extensive body of literature exists describing the properties of cells found in the primate vestibular nuclei (VN), the rat vestibular nuclei have not been explored in a comparable manner in order to allow for meaningful comparisons. Previous single-unit experiments in rat VN did not track eye movements and were performed in anesthetized or paralyzed preparations. This study characterizes the properties of vestibular-related cells in awake, behaving rats, using standard single-unit methodology, and video oculography to monitor eye movements, thus providing the first description that is comparable to the primate literature. Male, Long-Evans rats were head restrained and sinusoidally …  Lire la suite

Malignant glioma is the major brain tumor in adults, and has a poor prognosis. The failure to control invasive cell subpopulations may be the key reason for local glioma recurrence after radical tumor resection, and may contribute substantially to the failure of the other treatment modalities, such as radiation therapy and chemotherapy. As a model for this invasion, we have implanted spheroids from a human glioma cell line (U251) in three-dimensional collagen type I matrices which these cells readily invade. First, we observed that the Src family kinase specific pharmacological inhibitors PP2 and SU6656 significantly inhibited the invasion of the …  Lire la suite

The temporal pattern of the anterior-posterior force acting at the human knee joint during walking is determined in the present study. A three-dimensional anatomically based dynamics model, which includes the bones and the muscles working across the knee joint, is developed and the redundant inverse dynamics problem is formulated. The muscle redundancy is resolved by reducing the number of unknowns based on certain logical assumptions. In addition, a parametric study is conducted to study the effect of antagonistic muscle activity on the joint force. The developed dynamics model is then exercised to calculate the anterior-posterior knee joint force for normal …  Lire la suite

Type 1 Diabetes (T1D) is characterized by the autoimmune destruction of the insulin producing beta cells of the pancreas. Linkage with Type 1 Diabetes has been reported on chromosome 2q31-33. Within this 23 cM interval, T1D association with CTLA4 polymorphisms has been localized to a linkage disequilibrium (LD) block covering the D2S72- CTLA4-D2S116 interval. Within this interval, T1D is associated with a haplotype in the CTLA4 gene, containing several potentially functional polymorphisms. Due to the extent of LD in the region, genetics studies alone are not sufficient to identify the causative polymorphism(s). To this end, we undertook a systematic analysis …  Lire la suite