14,250 research outputs found

    A Fair Start? Child Mortality and Morbidity in the South West.

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    Children in the South West region are, overall, healthierthan their counterparts in other regions. However, many ofthe child deaths and much of the morbidity are potentiallyavoidable, suggesting that there is still considerable roomfor improvement.In order to understand how best these improvementscan be made, and which areas, causes and populationgroups should be prioritised, it is essential to understandvariations by age group, sex, deprivation and geography.This report has used readily available sources ofinformation to highlight some of these variations. Findingsof particular importance are:• Infant mortality rates are generally low in the regioncompared to England. Latest estimates suggest thatthe inequalities target for the South West is toughbut achievable by 2010. In addition, the region doesnot compare favourably to some of its Europeancounterparts on child health indicators, highlighting thefact that there is more to be done. If infant mortalityin the South West as a whole was at the level of thequintile with the lowest mortality, about 50 infant livescould be saved each year.• Mortality rates in children aged 1–19 are generallylower than in the first year of life, but these still exhibita steep socioeconomic gradient and a large proportionare potentially avoidable. The main causes of deathvary by age and sex, but injuries, suicides and cancersare the biggest contributors, making up over 50% of allcauses. Almost two-thirds of male deaths and half offemale deaths are classified as potentially avoidable.• There is also strong evidence of a steepsocioeconomic gradient for child morbidity in theregion.• Hospital admission rates in the South West are higherthan for England, and the causes of these admissionsvary by age, sex and deprivation. In younger children(aged 0–4) acute respiratory infections predominate,while the most common causes in children aged 5–14are injuries, especially in boys. The most commonreason for admissions in the 15–19 age group isneoplasms and accidents for boys, and abdominalpain, nausea and vomiting, and abortive pregnancy forgirls. Deliberate self-harm features among the reasonsfor emergency admission of girls of 15–19.• Generally, injuries, self-harm, abortive pregnancy andear, nose and throat (ENT) conditions contribute mostto childhood morbidity in the South West.These results show that, despite the fact that childrenin the South West are, on average, healthier than theircounterparts elsewhere in England, there are still largenumbers suffering from potentially avoidable conditions,which in some cases result in death. The majority of thesecases appear to be concentrated in the most deprivedcommunities. It is therefore paramount that decisionsand interventions focused on the health of children in theSouth West are targeted at the populations most at riskand at potentially avoidable causes

    Synthetic Observations of Simulated Radio Galaxies I: Radio and X-ray Analysis

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    We present an extensive synthetic observational analysis of numerically- simulated radio galaxies designed to explore the effectiveness of conventional observational analyses at recovering physical source properties. These are the first numerical simulations with sufficient physical detail to allow such a study. The present paper focuses on extraction of magnetic field properties from nonthermal intensity information. Synchrotron and inverse-Compton intensities provided meaningful information about distributions and strengths of magnetic fields, although considerable care was called for. Correlations between radio and X-ray surface brightness correctly revealed useful dynamical relationships between particles and fields. Magnetic field strength estimates derived from the ratio of X-ray to radio intensity were mostly within about a factor of two of the RMS field strength along a given line of sight. When emissions along a given line of sight were dominated by regions close to the minimum energy/equipartition condition, the field strengths derived from the standard power-law-spectrum minimum energy calculation were also reasonably close to actual field strengths, except when spectral aging was evident. Otherwise, biases in the minimum- energy magnetic field estimation mirrored actual differences from equipartition. The ratio of the inverse-Compton magnetic field to the minimum-energy magnetic field provided a rough measure of the actual total energy in particles and fields in most instances, within an order of magnitude. This may provide a practical limit to the accuracy with which one may be able to establish the internal energy density or pressure of optically thin synchrotron sources.Comment: 43 pages, 14 figures; accepted for publication in ApJ, v601 n2 February 1, 200

    APPLICATION OF COMPUTER INTENSIVE METHODS TO EVALUATE THE PERFORMANCE OF A SAMPLING DESIGN FOR USE IN COTTON INSECT PEST MANAGEMENT

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    A scouting protocol for cotton insect pests was developed which combines high resolution, multispectral remotely sensed imagery with a belt transect that crosses rows of cotton. Imagery was used to determine sample site selection while estimating plant bug abundance in a more than 200 ac. cotton field in 1997. Tarnished plant bug (Lygus lineolaris) counts were acquired using a standard drop cloth for each of eight rows along a transect. The sample data indicated that plant bug population densities spatially vary as a function of different spectral (color) classes present on the imagery. We postulate that such classified images correlate to differences in crop phenology, and plant bug populations (especially from early to mid-season) aggregate themselves by these habitat differences. Therefore, the population dynamics of Lygus, and possibly other species, can be better understood by combining the transect-based sampling plan with remotely sensed imagery. To verify and validate this claim, a computer intensive approach was utilized to simulate the performance of different sampling plans. The comparison is accomplished with a combinatorial algorithm that exhaustively enumerates the original data into unique subsets. These subsets correspond to results that could be expected from the use of traditional or alternative sampling plans and compared to results from the candidate plan actually used. The results of the enumerative analysis show the benefit of multi-band, remotely sensed imagery combined with the use of large sized sample units to improve sampling efficiency (and without the need to have large sample sizes). It is of great benefit that the enumerative algorithm provided answers to questions of interest without having to complete additional fieldwork

    Changing perceptions of weight in Great Britain: comparison of two population surveys

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    Objectives To examine changes in public perceptions of overweight in Great Britain over an eight year period

    The Line-of-Sight Proximity Effect and the Mass of Quasar Host Halos

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    We show that the Lyman-alpha optical depth statistics in the proximity regions of quasar spectra depend on the mass of the dark matter halos hosting the quasars. This is owing to both the overdensity around the quasars and the associated infall of gas toward them. For a fiducial quasar host halo mass of (3.0+/-1.6) h^-1 x 10^12 Msun, as inferred by Croom et al. from clustering in the 2dF QSO Redshift Survey, we show that estimates of the ionizing background (Gamma^bkg) from proximity effect measurements could be biased high by a factor of ~2.5 at z=3 owing to neglecting these effects alone. The clustering of galaxies and other active galactic nuclei around the proximity effect quasars enhances the local background, but is not expected to skew measurements by more than a few percent. Assuming the measurements of Gamma^bkg based on the mean flux decrement in the Ly-alpha forest to be free of bias, we demonstrate how the proximity effect analysis can be inverted to measure the mass of the dark matter halos hosting quasars. In ideal conditions, such a measurement could be made with a precision comparable to the best clustering constraints to date from a modest sample of only about 100 spectra. We discuss observational difficulties, including continuum flux estimation, quasar systematic redshift determination, and quasar variability, which make accurate proximity effect measurements challenging in practice. These are also likely to contribute to the discrepancies between existing proximity effect and flux decrement measurements of Gamma^bkg.Comment: 25 pages, including 14 figures, accepted by Ap

    An immunohistochemical assessment of cellular proliferation markers in head and neck squamous cell cancers.

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    Prognostic information is essential for the evaluation, judgement and optimal treatment of patients with squamous cell cancers (SCCs) of the upper aerodigestive tract. Using immunohistochemical and flow cytometric techniques, we have studied the significance of cellular expression of the Ki-67 antigen, epidermal growth factor receptor (EGFR), the transferrin receptor (TFR) and DNA ploidy status in a prospective analysis of patients with SCCs of the head and neck region. All 42 fresh tumour samples (five well differentiated; 28 moderately differentiated; nine poorly differentiated) expressed both EGFR and TFR to varying degrees. Receptor expression was most marked on the peripheral invading margin of cancer cell islands although staining was also demonstrated in a random fashion within cellular islands and consistently along the basal cell layer of overlying stratified squamous epithelium. The percentage of cancer cells that reacted with the Ki-67 monoclonal antibody was assessed as low (less than 10%) in 15 samples (35.8%), intermediate (10-30%) in 19 samples (45.2%) and high (greater than 30%) in eight samples (19.0%). Eleven of 15 samples (73%) with a low percentage reactivity were DNA diploid, whereas seven of eight samples (87.5%) with a high percentage reactivity were DNA aneuploid. Poorly differentiated SCCs were significantly more often aneuploid than were either moderately or well differentiated tumours. Our results suggest that EGFR and TFR are widely distributed on SCCs, especially on proliferating cells at the invading tumour margin. In addition, there is a close spatial correlation between cells expressing EGFR, TFR and those expressing the Ki-67 antigen. Tumours in which the staining intensity for both EGFR and TFR was intense invariably expressed the Ki-67 antigen in a high proportion of cells. Further patient follow-up will be important in determining whether intense EGFR and TFR staining, combined with a high percentage reactivity with Ki-67 antibody and DNA aneuploidy, will ultimately define a subset of head and neck cancer patients with a poor clinical outcome

    On the interpretation of spin-polarized electron energy loss spectra

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    We study the origin of the structure in the spin-polarized electron energy loss spectroscopy (SPEELS) spectra of ferromagnetic crystals. Our study is based on a 3d tight-binding Fe model, with constant onsite Coulomb repulsion U between electrons of opposite spin. We find it is not the total density of Stoner states as a function of energy loss which determines the response of the system in the Stoner region, as usually thought, but the densities of Stoner states for only a few interband transitions. Which transitions are important depends ultimately on how strongly umklapp processes couple the corresponding bands. This allows us to show, in particular, that the Stoner peak in SPEELS spectra does not necessarily indicate the value of the exchange splitting energy. Thus, the common assumption that this peak allows us to estimate the magnetic moment through its correlation with exchange splitting should be reconsidered, both in bulk and surface studies. Furthermore, we are able to show that the above mechanism is one of the main causes for the typical broadness of experimental spectra. Finally, our model predicts that optical spin waves should be excited in SPEELS experiments.Comment: 11 pages, 7 eps figures, REVTeX fil

    Observation of magnetization reversal and negative magnetization in a double perovskite compound Sr2YbRuO6

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    Detailed magnetic properties of the compound Sr2YbRuO6 are presented here. The compound belongs to the family of double perovskites forming a monoclinic structure. Magnetization meas-urements reveal clear evidence for two components of magnetic ordering aligned opposite to each other, leading to a magnetization reversal, compensation temperature (T* = 34 K) and neg-ative magnetization at low temperatures and low magnetic fields. Heat capacity measurements corroborate the presence of two components in the magnetic ordering and a noticeable third anomaly at low temperatures (~15 K) which cannot be attributed the Schottky effect. The calcu-lated magnetic entropy is substantially lower than that expected for the ground states of the or-dered moments of Ru5+ and Yb3+, indicating the presence of large crystal field effects and/ or in-complete magnetic ordering and/or magnetic frustrations well above the magnetic ordering. An attempt is made to explain the magnetization reversal within the frameworks of available models.Comment: 15 pages text, 6 figures Journal-ref: J.Phys.:Condens.Matter 20(2008)23520

    Cardiorespiratory Responses during 2-Person CPR using Two Assisted CPR Devices Versus Manual CPR

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    Active Compression-decompression-CPR (ACD-CPR) requires rescuers to perform work during both phases of CPR. ACD-CPR provides active pre-loading of a patient’s heart with venous return as well as enhanced stroke volume during resuscitation. Prolonged, one-person CPR is exhausting and associated with decayed CPR quality over time. Active compression-decompression-CPR (ACD-CPR) requires the rescuer to actively work during both phases of CPR. We evaluated the metabolic cost of manual CPR (M-CPR), ACD-CPR1, and ACD-CPR2 (with adhesive pad) during a 10-min resuscitation period. We hypothesized that the metabolic cost for the devices would be similar to M-CPR. Twenty (10 female) participants (23.5±3.5y, 165.8±25.6cm, 72.5±12.2kg) completed 3 randomized trials with performance feedback by investigators. Expired air was analyzed for estimations of metabolic cost via indirect calorimetry. Participants rested for 10 minutes before the baseline data collection followed by 10 min of CPR to simulate one-person CPR. Treatment effects were observed for VO2, METS, VCO2, RR, RQ, blood lactate, SBP, and RPE. No such effects were observed with HR and DBP as the observed condition differences for HR and DBP were not significantly different from each other. Blood lactate and SBP were significantly higher using ACD-CPR1 compared to MCPR and ACD-CPR2. Although a trend for elevated DBP was observed with ACD-CPR1, this was not significantly different. RQ values for the ACD-CPR1 device (1.0 ± 0.0) were significantly higher than the RQ values for M-CPR (0.9 ± 0.0) and ACD-CPR2 (0.9 ± 0.0). Assisted CPR using the ACD-CPR1 device is more stressful to the cardiorespiratory system as reflected by the higher SBP compared to the ACD-CPR1 or standard MCPR. Metabolically, the ACD-CPR1 required more VO2 and elicited higher RQ, RPE, and lactate values during 10-min simulated one-person resuscitation compared to M-CPR and ACD-CPR1. However, the ACD-CPR2 cardiorespiratory results were similar to that of M-CPR, despite the latter method’s higher rate of compressions (110/min) and passive decompressions

    Effects of Acute Vaporized Nicotine in Non-tobacco Users at Rest and During Exercise

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    Smokers, and even non-smokers, may utilize vaporized nicotine delivered by electronic cigarette (EC) due to the perception that EC are “healthier” than traditional tobacco cigarettes. The effects of vaporized nicotine delivered by EC on resting blood pressure (BP) and metabolic rate (RMR), or BP and aerobic power during exercise have not been studied. This investigation tested the effects of acute vaporized nicotine inhalation by EC on resting BP and RMR and cycle exercise BP, metabolic responses, and aerobic power in young, normotensive non-smokers. Using a double-blind design, 20 subjects (10 female; 23.1±2.5 years, 1.69±0.1 m, 70.6±14.9 kg; 22.1±11.0% body fat) self-reporting as healthy and non-smoking participated. All subjects participated in two randomized trials: placebo (0 mg nicotine) or nicotine (18 mg nicotine). Participants inhaled from EC once every 30 s for 10 min (20 inhalations total) during each trial. RMR was assessed 40 min later by indirect calorimetry followed by an incremental cycle test. Participants’ pre-inhalation SBP, DBP, and HR were also not significantly different between conditions or from those averaged over the last 5 min of the indirect calorimetry protocol. Cotinine, a stable nicotine metabolite, was assessed on post-inhalation (i.e., 10 min) urine samples. The cotinine concentration ranges, as scored using the semi-quantitative urine analysis kit strips, were significantly higher (p-1) compared to placebo (0-10 ng•ml-1). RMR was assessed ~40 min after the last EC inhalation. RMR (p=0.39), VO2 (p=0.5), RQ (p=0.15), and HR (p=0.47) were not significantly different between the placebo and nicotine trials. Compared to the placebo trial, nicotine use resulted in a 3.7 mmHg lower resting SBP (p=0.04) but a 3.0 mmHg higher DBP (p=0.04). VO2peak was not different between the nicotine trial (2.3±0.8 L•min-1) and placebo trial (2.3±0.7 L•min-1) trials (p=0.77). No statistically distinguishable difference was observed for Wpeak between nicotine (201.0±53.8 W) and placebo (204.8±57.8 W) (p=0.29). There was a main effect of time over the cycle test for VO2 , energy expenditure, RQ, and HR but no between treatment effects. A main treatment effect was identified for DBP, which was higher following nicotine compared to placebo at all time points during the test (p=0.05). No time by treatment interaction was identified for any variable during exercise. Exercise DBPpeak after nicotine (79.4±7.6) was significantly higher (p=0.02) than placebo (74.9±8.3 mmHg). Peak SBP was not different between trials (p=0.14). Our results show that acute vaporized nicotine inhalation via EC increases resting and exercise DBP but does not affect RMR or cycle aerobic power in young, normotensive non-smokers
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