Magnetic tunnel junction magnetic field sensor design tool

A spreadsheet-based magnetic tunnel junction (MTJ) sensor design tool is presented in this paper. The system is developed using Excel and Visual Basic Application. It allows users to optimize the various parameters of the sensor design with the goal of SQUID-like sensitivity. Users can input parameters of the design including magnetic properties, junction areas, and free layers thicknesses. The design tool will then calculate and display automatically various noise sources including Johnson noise, shot noise, 1/f noise, and thermal magnetic noise that must be considered when building MTJ magnetic field sensors. Graphs predicting the sensitivities, operating current and power of the finished sensors are shown and fine tuning of each design parameter is allowed using the scrollbars provided. Using this design tool, effects of changes made to any design parameter can be clearly observed and detailed noise analysis can be studied without manually repeating complex calculations. ©2010 IEEE.published_or_final_versionThe 3rd International Nanoelectronics Conference (INEC 2010), Hong Kong, China, 3-8 January 2010. In Proceedings of the 3rd INEC, 2010, p. 1149-115

Spatial imaging of the spin Hall effect and current-induced polarization in two-dimensional electron gases

Spin-orbit coupling in semiconductors relates the spin of an electron to its momentum and provides a pathway for electrically initializing and manipulating electron spins for applications in spintronics and spin-based quantum information processing. This coupling can be regulated with quantum confinement in semiconductor heterostructures through band structure engineering. Here we investigate the spin Hall effect and current-induced spin polarization in a two-dimensional electron gas confined in (110) AlGaAs quantum wells using Kerr rotation microscopy. In contrast to previous measurements, the spin Hall profile exhibits complex structure, and the current-induced spin polarization is out-of-plane. The experiments map the strong dependence of the current-induced spin polarization to the crystal axis along which the electric field is applied, reflecting the anisotropy of the spin-orbit interaction. These results reveal opportunities for tuning a spin source using quantum confinement and device engineering in non-magnetic materials.Comment: Accepted for publication (2005

Two decades of ART: improving on success through further research

Since the introduction of the Atraumatic Restorative Treatment (ART) approach over twenty years ago, more than 190 research publications have appeared. The last research agenda defining research priorities for ART was published in 1999. The objective of the present work was to review existing research in the context of future research priorities for ART. MATERIAL AND METHODS: An internet survey was conducted amongst those who had published on ART or were known to be working on the ART approach, to solicit their views as to areas of future ART research. Three broad categories were defined, namely: 1. Basic and laboratory research; 2. Clinical research, and, 3. Community, Public Health, Health Services Research. RESULTS: A 31% response rate was achieved. The study identified a number of new areas of research as well as areas where additional research is required. These are expressed as recommendations for future ART research. CONCLUSIONS: The ART approach is based on a robust, reliable and ever-growing evidence base concerning its clinical applications which indicates that it is a reliable and quality treatment approach. In common with all other oral health care procedures, targeted applied research is required to improve the oral health care offered

Impact of a silver layer on the membrane of tap water filters on the microbiological quality of filtered water

<p>Abstract</p> <p>Background</p> <p>Bacteria in the hospital's drinking water system represent a risk for the acquisition of a nosocomial infection in the severely immunocompromised host. Terminal tap water filters may be used to prevent nosocomial Legionnaires' disease. We present data from water samples using an improved kind of tap water filters.</p> <p>Methods</p> <p>In a blinded study on an intermediate care unit of the thoracic surgery department, a modified type of the Germlyser water filter (Aqua-Free Membrane Technology) with a newly-introduced silver layer on the filtration membrane was compared to its preceding type without such a layer on 15 water outlets. We determined growth of <it>Legionella</it>, other pathogenic bacteria, and the total heterotrophic plate count in unfiltered water and filtered water samples after filter usage intervals of 1 through 4 weeks.</p> <p>Results</p> <p>A total of 299 water samples were tested. Twenty-nine of the 60 unfiltered water samples contained <it>Legionella </it>of various serogroups (baseline value). In contrast, all samples filtered by the original water filter and all but one of the water samples filtered by the modified filter type remained <it>Legionella</it>-free. No other pathogenic bacteria were detected in any filtered sample. The total plate count in water samples increased during use of both kinds of filters over time. However, for the first 7 days of use, there were significantly fewer water samples containing >100 CFU per mL when using the new filter device compared with the older filters or taps with no filter. No advantage was seen thereafter.</p> <p>Conclusion</p> <p>The use of this type of terminal water filter is an appropriate method to protect immunocompromised patients from water-borne pathogens such as <it>Legionella</it>.</p

Temporal bone verrucous carcinoma: outcomes and treatment controversy

Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial

Exercise and the Prevention of Oesophageal Cancer (EPOC) study protocol: a randomized controlled trial of exercise versus stretching in males with Barrett's oesophagus

<p>Abstract</p> <p>Background</p> <p>Chronic gastro-oesophageal reflux disease and excessive body fat are considered principal causes of Barrett's oesophagus (a metaplastic change in the cells lining the oesophagus) and its neoplastic progression, oesophageal adenocarcinoma. Metabolic disturbances including altered levels of obesity-related cytokines, chronic inflammation and insulin resistance have also been associated with oesophageal cancer development, especially in males. Physical activity may have the potential to abrogate metabolic disturbances in males with Barrett's oesophagus and elicit beneficial reductions in body fat and gastro-oesophageal reflux symptoms. Thus, exercise may be an effective intervention in reducing oesophageal adenocarcinoma risk. However, to date this hypothesis remains untested.</p> <p>The 'Exercise and the Prevention of Oesophageal Cancer Study' will determine whether 24 weeks of exercise training will lead to alterations in risk factors or biomarkers for oesophageal adenocarcinoma in males with Barrett's oesophagus. Our primary outcomes are serum concentrations of leptin, adiponectin, tumour necrosis factor-alpha, C-reactive protein and interleukin-6 as well as insulin resistance. Body composition, gastro-oesophageal reflux disease symptoms, cardiovascular fitness and muscular strength will also be assessed as secondary outcomes.</p> <p>Methods/Design</p> <p>A randomized controlled trial of 80 overweight or obese, inactive males with Barrett's oesophagus will be conducted in Brisbane, Australia. Participants will be randomized to an intervention arm (60 minutes of moderate-intensity aerobic and resistance training, five days per week) or a control arm (45 minutes of stretching, five days per week) for 24 weeks. Primary and secondary endpoints will be measured at baseline (week 0), midpoint (week 12) and at the end of the intervention (week 24).</p> <p>Discussion</p> <p>Due to the increasing incidence and very high mortality associated with oesophageal adenocarcinoma, interventions effective in preventing the progression of Barrett's oesophagus are urgently needed. We propose that exercise may be successful in reducing oesophageal adenocarcinoma risk. This primary prevention trial will also provide information on whether the protective association between physical activity and cancer is causal.</p> <p>Trial Registration</p> <p>ACTRN12609000401257</p

The role of physical activity in the management of impaired glucose tolerance: a systematic review

Although physical activity is widely reported to reduce the risk of type 2 diabetes in individuals with prediabetes, few studies have examined this issue independently of other lifestyle modifications. The aim of this review is to conduct a systematic review of controlled trials to determine the independent effect of exercise on glucose levels and risk of type 2 diabetes in people with prediabetes (IGT and/or IFG). A detailed search of MEDLINE (1966–2006) and EMBASE (1980–2006) found 279 potentially relevant studies, eight of which met the inclusion criteria for this review. All eight studies were controlled trials in individuals with impaired glucose tolerance. Seven studies used a multi-component lifestyle intervention that included exercise, diet and weight loss goals and one used a structured exercise training intervention. Four studies used the incidence of diabetes over the course of the study as an outcome variable and four relied on 2-h plasma glucose as an outcome measure. In the four studies that measured the incidence of diabetes as an outcome, the risk of diabetes was reduced by approximately 50% (range 42–63%); as these studies reported only small changes in physical activity levels, the reduced risk of diabetes is likely to be attributable to factors other than physical activity. In the remaining four studies, only one reported significant improvements in 2-h plasma glucose even though all but one reported small to moderate increases in maximal oxygen uptake. These results indicate that the contribution of physical activity independent of dietary or weight loss changes to the prevention of type 2 diabetes in people with prediabetes is equivocal

A Genome-Wide RNAi Screen for Factors Involved in Neuronal Specification in Caenorhabditis elegans

One of the central goals of developmental neurobiology is to describe and understand the multi-tiered molecular events that control the progression of a fertilized egg to a terminally differentiated neuron. In the nematode Caenorhabditis elegans, the progression from egg to terminally differentiated neuron has been visually traced by lineage analysis. For example, the two gustatory neurons ASEL and ASER, a bilaterally symmetric neuron pair that is functionally lateralized, are generated from a fertilized egg through an invariant sequence of 11 cellular cleavages that occur stereotypically along specific cleavage planes. Molecular events that occur along this developmental pathway are only superficially understood. We take here an unbiased, genome-wide approach to identify genes that may act at any stage to ensure the correct differentiation of ASEL. Screening a genome-wide RNAi library that knocks-down 18,179 genes (94% of the genome), we identified 245 genes that affect the development of the ASEL neuron, such that the neuron is either not generated, its fate is converted to that of another cell, or cells from other lineage branches now adopt ASEL fate. We analyze in detail two factors that we identify from this screen: (1) the proneural gene hlh-14, which we find to be bilaterally expressed in the ASEL/R lineages despite their asymmetric lineage origins and which we find is required to generate neurons from several lineage branches including the ASE neurons, and (2) the COMPASS histone methyltransferase complex, which we find to be a critical embryonic inducer of ASEL/R asymmetry, acting upstream of the previously identified miRNA lsy-6. Our study represents the first comprehensive, genome-wide analysis of a single neuronal cell fate decision. The results of this analysis provide a starting point for future studies that will eventually lead to a more complete understanding of how individual neuronal cell types are generated from a single-cell embryo

Monotone and near-monotone biochemical networks

Monotone subsystems have appealing properties as components of larger networks, since they exhibit robust dynamical stability and predictability of responses to perturbations. This suggests that natural biological systems may have evolved to be, if not monotone, at least close to monotone in the sense of being decomposable into a “small” number of monotone components, In addition, recent research has shown that much insight can be attained from decomposing networks into monotone subsystems and the analysis of the resulting interconnections using tools from control theory. This paper provides an expository introduction to monotone systems and their interconnections, describing the basic concepts and some of the main mathematical results in a largely informal fashion

The impact of diabetes prevention on labour force participation and income of older Australians: an economic study

Background: Globally, diabetes is estimated to affect 246 million people and is increasing. In Australia diabetes has been made a national health priority. While the direct costs of treating diabetes are substantial, and rising, the indirect costs are considered greater. There is evidence that interventions to prevent diabetes are effective, and cost-effective, but the impact on labour force participation and income has not been assessed. In this study we quantify the potential impact of implementing a diabetes prevention program, using screening and either metformin or a lifestyle intervention on individual economic outcomes of pre-diabetic Australians aged 45-64. Methods. The output of an epidemiological microsimulation model of the reduction in prevalence of diabetes from a lifestyle or metformin intervention, and another microsimulation model, Health&WealthMOD, of health and the associated impacts on labour force participation, personal income, savings, government revenue and expenditure were used to quantify the estimated outcomes of the two interventions. Results: An additional 753 person years in the labour force would have been achieved from 1993 to 2003 for the male cohort aged 60-64 years in 2003, if a lifestyle intervention had been introduced in 1983; with 890 person years for the equivalent female group. The impact on labour force participation was lower for the metformin intervention, and increased with age for both interventions. The male cohort aged 60-64 years in 2003 would have earned an additional $30 million in income with the metformin intervention, and the equivalent female cohort would have earned an additional$25 million. If the lifestyle intervention was introduced, the same male and female cohorts would have earned an additional $34 million and$28 million respectively from 1993 to 2003. For the individuals involved, on average, males would have earned an additional $44,600 per year and females an additional$31,800 per year, if they had continued to work as a result of preventing diabetes. Conclusions: In addition to improved health and wellbeing, considerable benefits to individuals, in terms of both additional working years and increased personal income, could be made by introducing either a lifestyle or metformin intervention to prevent diabetes