986 research outputs found
A preliminary feasibility study for the underground disposal of carbon dioxide in UK
The Association of the Coal Producers of the European Community are agreed that immediate
action is required to reduce the build up of greenhouse gases in the atmosphere (Harrison,
1990). This is considered necessary even though the effect of these gases on global climate
and the human race, are very uncertain mainly because the factors and processes affecting
climatic change are poorly understood
The striatal dopamine transporter in first-episode, drug-naive schizophrenic patients: evaluation by the new SPECT-ligand[99mTc]TRODAT-1
Following the current hypothesis that acute schizophrenic psychotic illness is associated with a triatal ‘hyperdopaminergic state’, presynaptic integrity and dopamine transporter (DAT) density in first-episode, neuroleptic-naive schizophrenic patients was measured by single-photonemission- tomography (SPECT) and compared with that in healthy control subjects. A new SPECT-ligand for assessment of the striatal DAT, the Technetium-99m-labelled tropane TRODAT-1 ([99mTc]TRODAT-1), was used. Ten inpatients suffering from a first acute schizophrenic episode and 10 age- and sex-matched healthy control subjects underwent SPECT with [99mTc]TRODAT-1. On the day of SPECT, psychopathological ratings were performed with the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS) and Schedule for Assessment of Negative Symptoms (SANS). Patients had not previously received any neuroleptic or antidepressant medication. Mean specific TRODAT-1 binding in the striatum did not differ significantly between the patient and the age- and sex-matched control group (1.25 vs. 1.28). Variance was significantly higher in the patient group. The data obtained with the new ligand in first-episode, drug-naive schizophrenic patients are in line with the PET results from the group of Laakso et al. in a comparable patient sample. [99mTc]TRODAT-1 seems to be a valuable new SPECTligand in the evaluation of the presynaptic site of the striatal dopaminergic synapse in schizophrenia
A comparative study of arbitration algorithms for the Alpha 21364 pipelined router
Interconnection networks usually consist of a fabric of interconnected routers, which receive packets arriving at their input ports and forward them to appropriate output ports. Unfortunately, network packets moving through these routers are often delayed due to conflicting demand for resources, such as output ports or buffer space. Hence, routers typically employ arbiters that resolve conflicting resource demands to maximize the number of matches between packets waiting at input ports and free output ports. Efficient design and implementation of the algorithm running on these arbiters is critical to maximize network performance.This paper proposes a new arbitration algorithm called SPAA (Simple Pipelined Arbitration Algorithm), which is implemented in the Alpha 21364 processor's on-chip router pipeline. Simulation results show that SPAA significantly outperforms two earlier well-known arbitration algorithms: PIM (Parallel Iterative Matching) and WFA (Wave-Front Arbiter) implemented in the SGI Spider switch. SPAA outperforms PIM and WFA because SPAA exhibits matching capabilities similar to PIM and WFA under realistic conditions when many output ports are busy, incurs fewer clock cycles to perform the arbitration, and can be pipelined effectively. Additionally, we propose a new prioritization policy called the Rotary Rule, which prevents the network's adverse performance degradation from saturation at high network loads by prioritizing packets already in the network over new packets generated by caches or memory.Mukherjee, S.; Silla Jiménez, F.; Bannon, P.; Emer, J.; Lang, S.; Webb, D. (2002). A comparative study of arbitration algorithms for the Alpha 21364 pipelined router. ACM SIGPLAN Notices. 37(10):223-234. doi:10.1145/605432.605421S223234371
Safeguarding children in dentistry: 1. Child protection training, experience and practice of dental professionals with an interest in paediatric dentistry
* Few dental professionals with child protection training have experience of making referrals.
* There is a wide gap in practice between recognising signs of child abuse and neglect and responding effectively.
* This may indicate missed opportunities to save children from continuing abuse.
* There is a need for improved child protection information, support and training for dental professionals.
Abstract
Following several highly publicised inquiries into the deaths of children from abuse and neglect, there has been much recent interest in the role and responsibility of all health professionals to protect children at risk of maltreatment. The findings of a postal questionnaire, sent in March 2005 to 789 dentists and dental care professionals with an interest in paediatric dentistry working in varied settings in the UK, are presented in a two-part report and discussed in the context of current multi-agency good practice in safeguarding and promoting the welfare of children. This first part explores reported child protection training, experience and practice. There was a significant gap between recognising signs of abuse and responding effectively: 67% of respondents had suspected abuse or neglect of a child patient at some time in their career but only 29% had ever made a child protection referral. The dental profession is alerted to the need to ensure necessary appropriate action to safeguard children is always taken when child abuse or neglect are suspected
Moving beyond fitting fish into equations: Progressing the fish passage debate in the Anthropocene
Treasure codes: augmenting learning from physical museum exhibits through treasure hunting
Previous studies have highlighted the difficulty that designers face in creating mobile museum guides to enhance small group experiences. In this paper, we report a study exploring the potential of mobile visual recognition technology (Artcodes) to improve users’ experiences in a visitor centre. A prototype mobile guide in the form of a treasure hunt was developed and evaluated by means of a field study comparing this technology with the existing personal guided tour. The results reveal a preference for the mobile guide amongst participants and show significant learning gains from pre-test to post-test compared with the pre-existing personal tour. Our observational analyses indicate how the mobile guide can be used to improve visitors’ learning experiences by supporting active discovery and by balancing physical and digital interactions. We further expand the concept of design trajectories to consider micro-scaffolding as a way of understanding and designing future public technologies
Protein digestibility and relevance to allergenicity.
In January 2001 a Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Consultation Committee on Allergenicity of Foods Derived from Biotechnology published a report outlining in detail an approach for assessing the allergenic potential of novel proteins. One component of this decision tree is a determination of whether the protein of interest is resistant to proteolytic digestion. Although these (Italic)in vitro(/Italic) methodologies have been useful, the correlation between resistance to proteolysis and allergenic activity is not absolute. Two views and highlights of supporting research regarding the relationship of resistance to digestion and allergenicity are presented in this article
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Booster main magnet power supply, present operation and potential future upgrades
The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, +/-2000 Volts, or 3000 Amps, +/-6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the different modes of operation of the power supply. Since the power supply has been in operation for the last 18 years, upgrading this power supply is essential. A new power supply topology has been studied where energy is stored in capacitor banks. DC to DC converters are used to convert the dc voltage stored in the capacitor banks to pulsed DC voltage into the magnet load. This enables the average incoming power from the ac line to be constant while the peak magnet power is pulsed to +/- 18 MWatts. Simulations and waveforms of this power supply will be presented
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