"Ladyes, damesels, and jantilwomen": female autonomy and authority in Sir Thomas Malory's Morte Darthur

Popular medieval English romances were composed and received within the social consciousness of a distinctly patriarchal culture. This study examines the way in which the dynamic of these texts is significantly influenced by the consequences of female endeavour, in the context of an autonomous feminine presence in both the real and imagined worlds of medieval England, and the authority with which this is presented in various narratives, with a particular focus on Sir Thomas Malory’s Morte Darthur. Chapter One of this study establishes the social and economic positioning of the female in fifteenth-century England, and her capacity for literary engagement; I will then apply this model of female autonomy and authority to a wider discussion of texts contemporary with Malory in Chapters Two and Three, in anticipation of a more detailed study of Le Morte Darthur in Chapters Four and Five. My research explores the female presence and influence in these texts according to certain types: namely the lover, the victim, the ruler, and the temptress. In the case of Malory, the crux of my observations centres on the paradox of the capacity for power in perceived vulnerability, incorporating the presentation of women in this patriarchal culture as being vulnerable and in need of protection, while simultaneously acting as a significant threat to chivalric society by manipulating this apparent fragility, to the detriment of the chivalric knight. In this sense, women can be perceived as being an architect of the romance world, while simultaneously acting as its saboteur. In essence, this study offers an innovative interpretation of female autonomy and authority in medieval romance, presenting an exploration of the physical, intellectual, and emotional placement of women in both the historical and literary worlds of fifteenth-century England, while examining the implications of female conduct on Malory’s Arthurian society.

Achieving continuous professional development in higher education

Traditional higher education technology emphasizes knowledge transmission. In contrast, the Community platform presented in this paper follows a social approach that interleaves knowledge delivery with social and professional skills development, engaging with others, and personal growth. In this paper, we apply learning and complex adaptive systems theory to motivate and justify a continuous professional development model that improves higher education outcomes such as placement. The paper follows action design research (ADR) as the research method to propose and evaluate design principles.

Micro and nanostructured impedance sensors for biological and biomedical applications

This thesis work covered the fabrication and characterisation of impedance sensors for biological applications aiming in particular to the cytotoxicity monitoring of cultured cells exposed to different kind of chemical compounds and drugs and to the identification of different types of biological tissue (fat, muscles, nerves) using a sensor fabricated on the tip of a commercially available needle during peripheral nerve block procedures. Gold impedance electrodes have been successfully fabricated for impedance measurement on cells cultured on the electrode surface which was modified with the fabrication of gold nanopillars. These nanostructures have a height of 60nm or 100nm and they have highly ordered layout as they are fabricated through the e-beam technique. The fabrication of the threedimensional structures on the interdigitated electrodes was supposed to improve the sensitivity of the ECIS (electric cell-substrate impedance sensing) measurement while monitoring the cytotoxicity effects of two different drugs (Antrodia Camphorata extract and Nicotine) on three different cell lines (HeLa, A549 and BALBc 3T3) cultured on the impedance devices and change the morphology of the cells growing on the nanostructured electrodes. The fabrication of the nanostructures was achieved combining techniques like UV lithography, metal lift-off, evaporation and e-beam lithography techniques. The electrodes were packaged using a pressure sensitive, medical grade adhesive double-sided tape. The electrodes were then characterised with the aid of AFM and SEM imaging which confirmed the success of the fabrication processes showing the nanopillars fabricated with the right layout and dimensions figures. The introduction of nanopillars on the impedance electrodes, however, did not improve much the sensitivity of the assay with the exception of tests carried out with Nicotine. HeLa and A549 cells appeared to grow in a different way on the two surfaces, while no differences where noticed on the BALBc 3T3 cells. Impedance measurements obtained with the dead cells on the negative control electrodes or the test electrodes with the drugs can be compared to those done on the electrodes containing just media in the tested volume (as no cells are attached and cover the electrode surface). The impedance figures recorded using these electrodes were between 1.5kΩ and 2.5 kΩ, while the figures recorded on confluent cell layers range between 4kΩ and 5.5kΩ with peaks of almost 7 kΩ if there was more than one layer of cells growing on each other. There was then a very clear separation between the values of living cell compared to the dead ones which was almost 2.5 - 3kΩ. In this way it was very easy to determine whether the drugs affected the cells normal life cycle on not. However, little or no differences were noticed in the impedance analysis carried out on the two different kinds of electrodes using cultured cells. An increase of sensitivity was noticed only in a couple of experiments carried out on A549 cells growing on the nanostructured electrodes and exposed to different concentration of a solution containing Nicotine. More experiments to achieve a higher number of statistical evidences will be needed to prove these findings with an absolute confidence. The smart needle project aimed to reduce the limitations of the Electrical Nerve Stimulation (ENS) and the Ultra Sound Guided peripheral nerve block techniques giving the clinicians an additional tool for performing correctly the peripheral nerve block. Bioimpedance, as measured at the needle tip, provides additional information on needle tip location, thereby facilitating detection of intraneural needle placement. Using the needle as a precision instrument and guidance tool may provide additional information as to needle tip location and enhance safety in regional anaesthesia. In the time analysis, with the frequency fixed at 10kHz and the samples kept at 12°C, the approximate range for muscle bioimpedance was 203 – 616 Ω, the approximate bioimpedance range for fat was 5.02 - 17.8 kΩ and the approximate range for connective tissue was 790 Ω – 1.55 kΩ. While when the samples were heated at 37°C and measured again at 10kHz, the approximate bioimpedance range for muscle was 100-175Ω. The approximate bioimpedance range of fat was 627 Ω - 3.2 kΩ and the range for connective tissue was 221-540Ω. In the experiments done on the fresh slaughtered lamb carcass, replicating a scenario close to the real application, the impedance values recorded for fat were around 17 kΩ, for muscle and lean tissue around 1.3 kΩ while the nervous structures had an impedance value of 2.9 kΩ. With the data collected during this research, it was possible to conclude that measurements of bioimpedance at the needle tip location can give valuable information to the clinicians performing a peripheral nerve block procedure as the separation (in terms of impedance figures) was very marked between the different type of tissues. It is then feasible to use an impedance electrode fabricated on the needle tip to differentiate several tissues from the nerve tissue. Currently, several different methods are being studied to fabricate an impedance electrode on the surface of a commercially available needle used for the peripheral nerve block procedure.

Error recovery in cyberphysical digital microfluidic biochips

Droplet-based digital microfluidics technology has now come of age, and software-controlled biochips for healthcare applications are starting to emerge. However, today's digital microfluidic biochips suffer from the drawback that there is no feedback to the control software from the underlying hardware platform. Due to the lack of precision inherent in biochemical experiments, errors are likely during droplet manipulation; error recovery based on the repetition of experiments leads to wastage of expensive reagents and hard-to-prepare samples. By exploiting recent advances in the integration of optical detectors (sensors) into a digital microfluidics biochip, we present a physical-aware system reconfiguration technique that uses sensor data at intermediate checkpoints to dynamically reconfigure the biochip. A cyberphysical resynthesis technique is used to recompute electrode-actuation sequences, thereby deriving new schedules, module placement, and droplet routing pathways, with minimum impact on the time-to-response. © 2012 IEEE.

Outcomes of metallic stents for malignant ureteral obstruction.

PURPOSE: Malignant ureteral obstruction often necessitates chronic urinary diversion and is associated with high rates of failure with traditional ureteral stents. We evaluated the outcomes of a metallic stent placed for malignant ureteral obstruction and determined the impact of risk factors previously associated with increased failure rates of traditional stents. MATERIALS AND METHODS: Patients undergoing placement of the metallic Resonance® stent for malignant ureteral obstruction at an academic referral center were identified retrospectively. Stent failure was defined as unplanned stent exchange or nephrostomy tube placement for signs or symptoms of recurrent ureteral obstruction (recurrent hydroureteronephrosis or increasing creatinine). Predictors of time to stent failure were assessed using Cox regression. RESULTS: A total of 37 stents were placed in 25 patients with malignant ureteral obstruction. Of these stents 12 (35%) were identified to fail. Progressive hydroureteronephrosis and increasing creatinine were the most common signs of stent failure. Three failed stents had migrated distally and no stents required removal for recurrent infection. Patients with evidence of prostate cancer invading the bladder at stent placement were found to have a significantly increased risk of failure (HR 6.50, 95% CI 1.45-29.20, p = 0.015). Notably symptomatic subcapsular hematomas were identified in 3 patients after metallic stent placement. CONCLUSIONS: Failure rates with a metallic stent are similar to those historically observed with traditional polyurethane based stents in malignant ureteral obstruction. The invasion of prostate cancer in the bladder significantly increases the risk of failure. Patients should be counseled and observed for subcapsular hematoma formation with this device.

Comparison of extramedullary versus intramedullary referencing for tibial component alignment in total ankle arthroplasty.

BACKGROUND: The majority of total ankle arthroplasty (TAA) systems use extramedullary alignment guides for tibial component placement. However, at least 1 system offers intramedullary referencing. In total knee arthroplasty, studies suggest that tibial component placement is more accurate with intramedullary referencing. The purpose of this study was to compare the accuracy of extramedullary referencing with intramedullary referencing for tibial component placement in total ankle arthroplasty. METHODS: The coronal and sagittal tibial component alignment was evaluated on the postoperative weight-bearing anteroposterior (AP) and lateral radiographs of 236 consecutive fixed-bearing TAAs. Radiographs were measured blindly by 2 investigators. The postoperative alignment of the prosthesis was compared with the surgeon's intended alignment in both planes. The accuracy of tibial component alignment was compared between the extramedullary and intramedullary referencing techniques using unpaired t tests. Interrater and intrarater reliabilities were assessed with intraclass correlation coefficients (ICCs). RESULTS: Eighty-three tibial components placed with an extramedullary referencing technique were compared with 153 implants placed with an intramedullary referencing technique. The accuracy of the extramedullary referencing was within a mean of 1.5 ± 1.4 degrees and 4.1 ± 2.9 degrees in the coronal and sagittal planes, respectively. The accuracy of intramedullary referencing was within a mean of 1.4 ± 1.1 degrees and 2.5 ± 1.8 degrees in the coronal and sagittal planes, respectively. There was a significant difference (P < .001) between the 2 techniques with respect to the sagittal plane alignment. Interrater ICCs for coronal and sagittal alignment were high (0.81 and 0.94, respectively). Intrarater ICCs for coronal and sagittal alignment were high for both investigators. CONCLUSIONS: Initial sagittal plane tibial component alignment was notably more accurate when intramedullary referencing was used. Further studies are needed to determine the effect of this difference on clinical outcomes and long-term survivability of the implants. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Sound the alarm: fraud in neuroscience.

We expect scientists to follow a code of honor and conduct and to report their research honestly and accurately, but so-called scientific misconduct, which includes plagiarism, faked data, and altered images, has led to a tenfold increase in the number of retractions over the past decade. Among the reasons for this troubling upsurge is increased competition for journal placement, grant money, and prestigious appointments. The solutions are not easy, but reform and greater vigilance is needed.

Interstitial engraftment of adipose-derived stem cells into an acellular dermal matrix results in improved inward angiogenesis and tissue incorporation.

Acellular dermal matrices (ADM) are commonly used in reconstructive procedures and rely on host cell invasion to become incorporated into host tissues. We investigated different approaches to adipose-derived stem cells (ASCs) engraftment into ADM to enhance this process. Lewis rat adipose-derived stem cells were isolated and grafted (3.0 × 10(5) cells) to porcine ADM disks (1.5 mm thick × 6 mm diameter) using either passive onlay or interstitial injection seeding techniques. Following incubation, seeding efficiency and seeded cell viability were measured in vitro. In addition, Eighteen Lewis rats underwent subcutaneous placement of ADM disk either as control or seeded with PKH67 labeled ASCs. ADM disks were seeded with ASCs using either onlay or injection techniques. On day 7 and or 14, ADM disks were harvested and analyzed for host cell infiltration. Onlay and injection techniques resulted in unique seeding patterns; however cell seeding efficiency and cell viability were similar. In-vivo studies showed significantly increased host cell infiltration towards the ASCs foci following injection seeding in comparison to control group (p < 0.05). Moreover, regional endothelial cell invasion was significantly greater in ASCs injected grafts in comparison to onlay seeding (p < 0.05). ADM can successfully be engrafted with ASCs. Interstitial engraftment of ASCs into ADM via injection enhances regional infiltration of host cells and angiogenesis, whereas onlay seeding showed relatively broad and superficial cell infiltration. These findings may be applied to improve the incorporation of avascular engineered constructs.

Are component positioning and prosthesis size associated with hip resurfacing failure?

BACKGROUND: Recent studies suggest that there is a learning curve for metal-on-metal hip resurfacing. The purpose of this study was to assess whether implant positioning changed with surgeon experience and whether positioning and component sizing were associated with implant longevity. METHODS: We evaluated the first 361 consecutive hip resurfacings performed by a single surgeon, which had a mean follow-up of 59 months (range, 28 to 87 months). Pre and post-operative radiographs were assessed to determine the inclination of the acetabular component, as well as the sagittal and coronal femoral stem-neck angles. Changes in the precision of component placement were determined by assessing changes in the standard deviation of each measurement using variance ratio and linear regression analysis. Additionally, the cup and stem-shaft angles as well as component sizes were compared between the 31 hips that failed over the follow-up period and the surviving components to assess for any differences that might have been associated with an increased risk for failure. RESULTS: Surgeon experience was correlated with improved precision of the antero-posterior and lateral positioning of the femoral component. However, femoral and acetabular radiographic implant positioning angles were not different between the surviving hips and failures. The failures had smaller mean femoral component diameters as compared to the non-failure group (44 versus 47 millimeters). CONCLUSIONS: These results suggest that there may be differences in implant positioning in early versus late learning curve procedures, but that in the absence of recognized risk factors such as intra-operative notching of the femoral neck and cup inclination in excess of 50 degrees, component positioning does not appear to be associated with failure. Nevertheless, surgeons should exercise caution in operating patients with small femoral necks, especially when they are early in the learning curve.

Biogeography in deep time - What do phylogenetics, geology, and paleoclimate tell us about early platyrrhine evolution?

Molecular data have converged on a consensus about the genus-level phylogeny of extant platyrrhine monkeys, but for most extinct taxa and certainly for those older than the Pleistocene we must rely upon morphological evidence from fossils. This raises the question as to how well anatomical data mirror molecular phylogenies and how best to deal with discrepancies between the molecular and morphological data as we seek to extend our phylogenies to the placement of fossil taxa. Here I present parsimony-based phylogenetic analyses of extant and fossil platyrrhines based on an anatomical dataset of 399 dental characters and osteological features of the cranium and postcranium. I sample 16 extant taxa (one from each platyrrhine genus) and 20 extinct taxa of platyrrhines. The tree structure is constrained with a "molecular scaffold" of extant species as implemented in maximum parsimony using PAUP with the molecular-based 'backbone' approach. The data set encompasses most of the known extinct species of platyrrhines, ranging in age from latest Oligocene (∼26 Ma) to the Recent. The tree is rooted with extant catarrhines, and Late Eocene and Early Oligocene African anthropoids. Among the more interesting patterns to emerge are: (1) known early platyrrhines from the Late Oligocene through Early Miocene (26-16.5Ma) represent only stem platyrrhine taxa; (2) representatives of the three living platyrrhine families first occur between 15.7 Ma and 13.5 Ma; and (3) recently extinct primates from the Greater Antilles (Cuba, Jamaica, Hispaniola) are sister to the clade of extant platyrrhines and may have diverged in the Early Miocene. It is probable that the crown platyrrhine clade did not originate before about 20-24 Ma, a conclusion consistent with the phylogenetic analysis of fossil taxa presented here and with recent molecular clock estimates. The following biogeographic scenario is consistent with the phylogenetic findings and climatic and geologic evidence: Tropical South America has been a center for platyrrhine diversification since platyrrhines arrived on the continent in the middle Cenozoic. Platyrrhines dispersed from tropical South America to Patagonia at ∼25-24 Ma via a "Paraná Portal" through eastern South America across a retreating Paranense Sea. Phylogenetic bracketing suggests Antillean primates arrived via a sweepstakes route or island chain from northern South America in the Early Miocene, not via a proposed land bridge or island chain (GAARlandia) in the Early Oligocene (∼34 Ma). Patagonian and Antillean platyrrhines went extinct without leaving living descendants, the former at the end of the Early Miocene and the latter within the past six thousand years. Molecular evidence suggests crown platyrrhines arrived in Central America by crossing an intermittent connection through the Isthmus of Panama at or after 3.5Ma. Any more ancient Central American primates, should they be discovered, are unlikely to have given rise to the extant Central American taxa in situ.

Investigation of Blast Wave Propagation: Correlating External Pressures to Brain Injury Predictors

Blast-induced Traumatic Brain Injury (bTBI) is the signature injury of the Iraq and Afghanistan wars; however, current understanding of bTBI is insufficient. In this study, novel analysis methods were developed to investigate correlations between external pressures and brain injury predictors. Experiments and simulations were performed to analyze placement of helmet-mounted pressure sensors. A 2D Finite Element model of a helmeted head cross-section was loaded with a blast wave. Pressure time-histories for nodes on the inner and outer surfaces of the helmet were cross-correlated to those inside the brain. Parallel physical experiments were carried out with a helmeted headform, pressure sensors, and pressure chamber. These analysis methods can potentially lead to better helmet designs and earlier detection and treatment of bTBI.

A multilevel algorithm for force-directed graph drawing

We describe a heuristic method for drawing graphs which uses a multilevel technique combined with a force-directed placement algorithm. The multilevel process groups vertices to form clusters, uses the clusters to define a new graph and is repeated until the graph size falls below some threshold. The coarsest graph is then given an initial layout and the layout is successively refined on all the graphs starting with the coarsest and ending with the original. In this way the multilevel algorithm both accelerates and gives a more global quality to the force- directed placement. The algorithm can compute both 2 & 3 dimensional layouts and we demonstrate it on a number of examples ranging from 500 to 225,000 vertices. It is also very fast and can compute a 2D layout of a sparse graph in around 30 seconds for a 10,000 vertex graph to around 10 minutes for the largest graph. This is an order of magnitude faster than recent implementations of force-directed placement algorithms.

A multilevel algorithm for force-directed graph-drawing

We describe a heuristic method for drawing graphs which uses a multilevel framework combined with a force-directed placement algorithm. The multilevel technique matches and coalesces pairs of adjacent vertices to define a new graph and is repeated recursively to create a hierarchy of increasingly coarse graphs, G0, G1, …, GL. The coarsest graph, GL, is then given an initial layout and the layout is refined and extended to all the graphs starting with the coarsest and ending with the original. At each successive change of level, l, the initial layout for Gl is taken from its coarser and smaller child graph, Gl+1, and refined using force-directed placement. In this way the multilevel framework both accelerates and appears to give a more global quality to the drawing. The algorithm can compute both 2 & 3 dimensional layouts and we demonstrate it on examples ranging in size from 10 to 225,000 vertices. It is also very fast and can compute a 2D layout of a sparse graph in around 12 seconds for a 10,000 vertex graph to around 5-7 minutes for the largest graphs. This is an order of magnitude faster than recent implementations of force-directed placement algorithms.

Microwave modelling and validation in food thawing applications

Developing temperature fields in frozen cheese sauce undergoing microwave heating were simulated and measured. Two scenarios were investigated: a centric and offset placement on the rotating turntable. Numerical modeling was performed using a dedicated electromagnetic Finite Difference Time Domain (FDTD) module that was two-way coupled to the PHYSICA multiphysics package. Two meshes were used: the food material and container were meshed for the heat transfer and the microwave oven cavity and waveguide were meshed for the microwave field. Power densities obtained on the structured FDTD mesh were mapped onto the unstructured finite volume method mesh for each time-step/turntable position. On heating for each specified time-step the temperature field was mapped back onto the FDTD mesh and the electromagnetic properties were updated accordingly. Changes in thermal/electric properties associated with the phase transition were fully accounted for as well as heat losses from product to cavity. Detailed comparisons were carried out for the centric and offset placements, comparing experimental temperature profiles during microwave thawing with those obtained by numerical simulation.

Multiphysics simulation of microwave curing in micro-electronics packaging applications

Purpose – This paper aims to present an open-ended microwave curing system for microelectronics components and a numerical analysis framework for virtual testing and prototyping of the system, enabling design of physical prototypes to be optimized, expediting the development process. Design/methodology/approach – An open-ended microwave oven system able to enhance the cure process for thermosetting polymer materials utilised in microelectronics applications is presented. The system is designed to be mounted on a precision placement machine enabling curing of individual components on a circuit board. The design of the system allows the heating pattern and heating rate to be carefully controlled optimising cure rate and cure quality. A multi-physics analysis approach has been adopted to form a numerical model capable of capturing the complex coupling that exists between physical processes. Electromagnetic analysis has been performed using a Yee finite-difference time-domain scheme, while an unstructured finite volume method has been utilized to perform thermophysical analysis. The two solvers are coupled using a sampling-based cross-mapping algorithm. Findings – The numerical results obtained demonstrate that the numerical model is able to obtain solutions for distribution of temperature, rate of cure, degree of cure and thermally induced stresses within an idealised polymer load heated by the proposed microwave system. Research limitations/implications – The work is limited by the absence of experimentally derived material property data and comparative experimental results. However, the model demonstrates that the proposed microwave system would seem to be a feasible method of expediting the cure rate of polymer materials. Originality/value – The findings of this paper will help to provide an understanding of the behaviour of thermosetting polymer materials during microwave cure processing.