Initial Work (initial + work)

Distribution by Scientific Domains

Selected Abstracts

Mechanisms and consequences of bladder cell invasion by uropathogenic Escherichia coli

B. K. Dhakal
ABSTRACT Strains of uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections worldwide. Multiple studies over the past decade have called into question the dogmatic view that UPEC strains act as strictly extracellular pathogens. Rather, bacterial expression of filamentous adhesive organelles known as type 1 pili and Afa/Dr fibrils enable UPEC to invade host epithelial cells within the urinary tract. Entry into bladder epithelial cells provides UPEC with a protected niche where the bacteria can persist quiescently for long periods, unperturbed by host defences and protected from many antibiotic treatments. Alternately, internalized UPEC can rapidly multiply, forming large intracellular inclusions that can contain several thousand bacteria. Initial work aimed at defining the host and bacterial factors that modulate the entry, intracellular trafficking, and eventual resurgence of UPEC suggests a high degree of host-pathogen crosstalk. Targeted disruption of these processes may provide a novel means to prevent and treat recurrent, relapsing and chronic infections within the urinary tract. [source]

OLIG-1 and 2 gene expression and oligodendroglial tumours

K. Hoang-Xuan
OLIG 1/2 genes encode basic helix-loop-helix transcription factors that play a critical role in motor neurone and oligodendrocyte fate specification during development. Two recent studies in which OLIG transcripts were detected by in situ hybridization have reported a high expression of the OLIG genes in oligodendrogliomas. This suggests that the detection of these lineage markers could become an adjunct to the classic morphological diagnosis of these tumours. There are problems in the diagnosis of oligodendroglioma. To date, all other known oligodendrocyte lineage markers have failed to label specifically neoplastic oligodendrocytes. Deletions on chromosome 1p and 19q are much more frequent in oligodendrogliomas than in astrocytomas but these molecular alterations are not constant. For the future, when routinely available, immunohistochemical techniques using anti-OLIG antibodies on paraffin embedded tissues will allow a systematic study of a large series of tumours so that we will know the specificity and sensitivity of this investigation in diagnosis. At another level, it is possible that expression of OLIG in neoplastic oligodendrocyte might participate in the oncogenesis of oligodendrogliomas. Initial work suggests that this is probably not the case. However further in vitro and in vivo studies analysing the functional consequence of OLIG overexpression in terms of proliferation and tumour progression are needed. [source]

First experience of compressible gas dynamics simulation on the Los Alamos roadrunner machine

Paul R. Woodward
Abstract We report initial experience with gas dynamics simulation on the Los Alamos Roadrunner machine. In this initial work, we have restricted our attention to flows in which the flow Mach number is less than 2. This permits us to use a simplified version of the PPM gas dynamics algorithm that has been described in detail by Woodward (2006). We follow a multifluid volume fraction using the PPB moment-conserving advection scheme, enforcing both pressure and temperature equilibrium between two monatomic ideal gases within each grid cell. The resulting gas dynamics code has been extensively restructured for efficient multicore processing and implemented for scalable parallel execution on the Roadrunner system. The code restructuring and parallel implementation are described and performance results are discussed. For a modest grid size, sustained performance of 3.89 Gflops,1 CPU-core,1 is delivered by this code on 36 Cell processors in 9 triblade nodes of a single rack of Roadrunner hardware. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Eye gaze in virtual environments: evaluating the need and initial work on implementation

Norman Murray
Abstract For efficient collaboration between participants, eye gaze is seen as being critical for interaction. Video conferencing either does not attempt to support eye gaze (e.g. AcessGrid) or only approximates it in round table conditions (e.g. life size telepresence). Immersive collaborative virtual environments represent remote participants through avatars that follow their tracked movements. By additionally tracking people's eyes and representing their movement on their avatars, the line of gaze can be faithfully reproduced, as opposed to approximated. This paper presents the results of initial work that tested if the focus of gaze could be more accurately gauged if tracked eye movement was added to that of the head of an avatar observed in an immersive VE. An experiment was conducted to assess the difference between user's abilities to judge what objects an avatar is looking at with only head movements being displayed, while the eyes remained static, and with eye gaze and head movement information being displayed. The results from the experiment show that eye gaze is of vital importance to the subjects correctly identifying what a person is looking at in an immersive virtual environment. This is followed by a description of the work that is now being undertaken following the positive results from the experiment. We discuss the integration of an eye tracker more suitable for immersive mobile use and the software and techniques that were developed to integrate the user's real-world eye movements into calibrated eye gaze in an immersive virtual world. This is to be used in the creation of an immersive collaborative virtual environment supporting eye gaze and its ongoing experiments. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Compiler and runtime techniques for software transactional memory optimization

Peng Wu
Abstract Software transactional memory (STM) systems are an attractive environment to evaluate optimistic concurrency. We describe our experience of supporting and optimizing an STM system at both the managed runtime and compiler levels. We describe the design policies of our STM system and the statistics collected by the runtime to identify performance bottlenecks and guide tuning decisions. We present an initial work on supporting automatic instrumentation of the STM primitives for C/C++ and Java programs in the IBM XL compiler and J9 Java virtual machine. We evaluate and discuss the performance of several transactional programs running on our system. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Contactless Conductivity Detection in Capillary Electrophoresis: A Review

Pavel Kubá
Abstract The popularity of contactless conductivity detection in capillary electrophoresis has been growing steadily over the last few years. Improvements have been made in the design of the detector in order to facilitate its handling, to allow easy incorporation into available instruments or to achieve higher sensitivity. The understanding of its fundamental working principles has been advanced and the detection approach has also been transferred to lab-on-chip devices. The range of applications has been extended greatly from the initial work on small inorganic ions to include organic species and biomolecules. Concurrent determination of cations and anions by dual injection from opposite ends has been demonstrated as well as sample introduction by using flow-injection systems for easy automation of the process. [source]

GIS visualisation and analysis of mobile hydroacoustic fisheries data: a practical example

Abstract, Hydroacoustic remote sensing of fish populations residing in large freshwater bodies has become a widely used and effective monitoring tool. However, easy visualisation of the data and effective analysis is more problematic. The use of GIS-based interpolations enables easy visualisation of survey data and an analysis tool for investigating fish populations. Three years of hydroacoustic surveys of Cardiff Bay in South Wales presented an opportunity to develop analysis and visualisation techniques. Inverse distance weighted (IDW) interpolation was used to show the potential of such techniques in analysing survey data both spatially (1-year survey) and temporally (by looking at the spatial changes between years). IDW was fairly successful in visualising the hydroacoustic data for Cardiff Bay. However, other techniques may improve on this initial work and provide improved analysis, total density estimates and statistically derived estimations of prediction error. [source]

Detecting microdamage in bone

T. C. Lee
Abstract Fatigue-induced microdamage in bone contributes to stress and fragility fractures and acts as a stimulus for bone remodelling. Detecting such microdamage is difficult as pre-existing microdamage sustained in vivo must be differentiated from artefactual damage incurred during specimen preparation. This was addressed by bulk staining specimens in alcohol-soluble basic fuchsin dye, but cutting and grinding them in an aqueous medium. Nonetheless, some artefactual cracks are partially stained and careful observation under transmitted light, or epifluorescence microscopy, is required. Fuchsin lodges in cracks, but is not site-specific. Cracks are discontinuities in the calcium-rich bone matrix and chelating agents, which bind calcium, can selectively label them. Oxytetracycline, alizarin complexone, calcein, calcein blue and xylenol orange all selectively bind microcracks and, as they fluoresce at different wavelengths and colours, can be used in sequence to label microcrack growth. New agents that only fluoresce when involved in a chelate are currently being developed , fluorescent photoinduced electron transfer (PET) sensors. Such agents enable microdamage to be quantified and crack growth to be measured and are useful histological tools in providing data for modelling the material behaviour of bone. However, a non-invasive method is needed to measure microdamage in patients. Micro-CT is being studied and initial work with iodine dyes linked to a chelating group has shown some promise. In the long term, it is hoped that repeated measurements can be made at critical sites and microdamage accumulation monitored. Quantification of microdamage, together with bone mass measurements, will help in predicting and preventing bone fracture failure in patients with osteoporosis. [source]

Idealized design of perinatal care

Faith McLellan PhD
Idealized Design of Perinatal Care is an innovation project based on the principles of reliability science and the Institute for Healthcare Improvement's (IHI's) model for applying these principles to improve care.1 The project builds upon similar processes developed for other clinical arenas in three previous IHI Idealized Design projects. The Idealized Design model focuses on comprehensive redesign to enable a care system to perform substantially better in the future than the best it can do at present. The goal of Idealized Design of Perinatal Care is to achieve a new level of safer, more effective care and to minimize some of the risks identified in medical malpractice cases. The model described in this white paper, Idealized Design of Perinatal Care, represents the Institute for Healthcare Improvement's best current assessment of the components of the safest and most reliable system of perinatal care. The four key components of the model are: 1) the development of reliable clinical processes to manage labor and delivery; 2) the use of principles that improve safety (i.e., preventing, detecting, and mitigating errors); 3) the establishment of prepared and activated care teams that communicate effectively with each other and with mothers and families; and 4) a focus on mother and family as the locus of control during labor and delivery. Reviews of perinatal care have consistently pointed to failures of communication among the care team and documentation of care as common factors in adverse events that occur in labor and delivery. They are also prime factors leading to malpractice claims.2 Two perinatal care "bundles", a group of evidence-based interventions related to a disease or care process that, when executed together, result in better outcomes than when implemented individually , are being tested in this Idealized Design project: the Elective Induction Bundle and the Augmentation Bundle. Experience from the use of bundles in other clinical areas, such as care of the ventilated patient, has shown that reliably applying these evidence-based interventions can dramatically improve outcomes.3 The assumption of this innovation work is that the use of bundles in the delivery of perinatal care will have a similar effect. The authors acknowledge that other organizations have also been working on improving perinatal care through the use of simulation training and teamwork and communication training. IHI's model includes elements of these methods. The Idealized Design of Perinatal Care project has two phases. Sixteen perinatal units from hospitals around the US participated in Phase I, from February to August 2005. The goals of Phase I were identifying changes that would make the most impact on improving perinatal care, selecting elements for each of the bundles, learning how to apply IHI's reliability model to improve processes, and improving the culture within a perinatal unit. This white paper provides detail about the Idealized Design process and examines some of the initial work completed by teams. Phase II, which began in September 2005, expands on this work. This phase focuses particularly on managing second stage labor, including common interpretation of fetal heart monitoring, developing a reliable tool to identify harm, and ensuring that patient preferences are known and honored. [source]

Green tea: Health benefits as cancer preventive for humans

Hirota Fujiki
Abstract Green tea is an acknowledged cancer preventive in Japan. The aim of this review article is to develop the concept of cancer prevention with green tea beverage for humans, which has largely been our exclusive research territory. This paper briefly reviews several topics, beginning with the introduction of our initial work on penta- O -galloyl-,-D-glucose and (,)-epigallocatechin gallate (EGCG), the main constituent of green tea extract. The mechanisms of EGCG action, particularly the reduction of TNF-, are discussed, and we show how use of 3H-EGCG revealed a wide range of target organs for cancer prevention. The results of an epidemiological study in Saitama Prefecture allowed us to determine the cancer preventive amount of green tea,10 Japanese-size cups per day, about 2.5,g green tea extract,which made it possible for us to introduce the two-stage strategy of cancer prevention with green tea. The first stage is the delay of cancer onset for the general population. The second stage is the prevention of recurrence of cancer for patients following cancer treatment. Combination cancer prevention with green tea and cancer preventive drugs is proving especially beneficial for Japanese, who drink green tea every day. And finally, the stimulating comments of Prof. Jim Watson have encouraged green tea scientists. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 119,132; 2005: Published online in Wiley InterScience ( DOI 10.1002/tcr.20039 [source]

Novel nickel-based catalyst for low temperature hydrogen production from methane steam reforming in membrane reformer

Yazhong Chen
Abstract Hydrogen production from various hydrocarbon fuels, particularly biomass-derived fuels, has attracted worldwide attention due to its potential for application to fuel cells, a device which converts chemical energy into electricity efficiently and cleanly. However, current technology, such as natural gas steam reforming, could not meet the specific requirements of hydrogen for fuel cells. Therefore, novel processes are intensively investigated, aiming to develop economic and efficient ones for the specific purpose. An important direction is the integrated membrane reformer for one-step high-purity hydrogen production. However, for the commercial realization of this technology, there are still some difficulties to overcome. By comparison with previous investigations with a similar membrane, this work showed that catalyst also played an important role in determining membrane reformer performance. We proposed that when thickness of membrane was several micrometers, the permeance of membrane became less important than the kinetics of catalyst, due to the fact that under such conditions, hydrogen permeation rate was faster than the kinetics of steam reforming reaction when commercial catalyst was applied, but further evidence is indispensable. In this initial work, we focused on developing efficient nickel catalyst for low temperature steam reforming. Nickel-based catalyst was developed by deposition,coprecipitation and used as pre-reduced, showing high performance for methane steam reforming at low temperatures and good durability, which may find practical application for the integrated membrane reforming process. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Acidosis and Catecholamine Evaluation Following Simulated Law Enforcement "Use of Force" Encounters

Jeffrey D. Ho MD
ACADEMIC EMERGENCY MEDICINE 2010; 17:E60,E68 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, Law enforcement authorities are often charged with controlling resisting suspects. These encounters sometimes result in the sudden and unexpected death of the suspect. Drug intoxication, excited delirium syndrome, or excessive uses of force are factors that are often blamed, but sometimes the mechanism of these deaths is not fully understood. It is possible that worsening acidosis or excessive catecholamine release play a part. The objective of this study was to determine the effect on markers of acidosis and catecholamines of various tasks intended to simulate common arrest-related situations. Methods:, Subjects were assigned to one of five task groups: 1) a 150-meter sprint and wall hurdle (simulated flight from arrest); 2) 45 seconds of striking a heavy bag (simulated physical resistance); 3) a 10-second TASER X26 electronic control device exposure; 4) a fleeing and resistance exercise involving a law enforcement dog (K-9); or 5) an oleoresin capsicum (OC) exposure to the face and neck. Baseline serum pH, lactate, potassium, troponin I, catecholamines, and creatine kinase (CK) were evaluated. Serum catecholamines, pH, lactate, and potassium were sampled immediately after the task and every 2 minutes for 10 minutes posttask. Vital signs were repeated immediately after the task. Serum CK and troponin I were evaluated again at 24 hours posttask. Results:, Sixty-six subjects were enrolled; four did not complete their assigned task. One subject lost the intravenous (IV) access after completing the task and did not have data collected, and one subject only received a 5-second TASER device exposure and was excluded from the study, leaving 12 subjects in each task group. The greatest changes in acidosis markers occurred in the sprint and heavy bag groups. Catecholamines increased the most in the heavy bag group and the sprint group and increased to a lesser degree in the TASER, OC, and K-9 groups. Only the sprint group showed an increase in CK at 24 hours. There were no elevations in troponin I in any group, nor any clinically important changes in potassium. Conclusions:, The simulations of physical resistance and fleeing on foot led to the greatest changes in markers of acidosis and catecholamines. These changes may be contributing or causal mechanisms in sudden custodial arrest-related deaths (ARDs). This initial work may have implications in guiding applications of force for law enforcement authorities (LEAs) when apprehending resisting subjects. [source]