1,197 research outputs found
The X-ray spectrum of the Seyfert I galaxy Markarian 766: Dusty warm absorber or relativistic emission lines?
Competing models for broad spectral features in the soft X-ray spectrum of the Seyfert I galaxy Mrk 766 are tested against data from a 130 ks XMM-Newton observation. A model including relativistically broadened Lyalpha emission lines of O VIII N VII and C VI is a better fit to 0.3-2 keV XMM RGS data than a dusty warm absorber. Moreover, the measured depth of neutral iron absorption lines in the spectrum is inconsistent with the magnitude of the iron edge required to produce the continuum break at 17-18 Angstrom in the dusty warm absorber model. The relativistic emission line model can reproduce the broadband (0.1-12 keV) XMM EPIC data with the addition of a fourth line to represent emission from ionized iron at 6.7 keV and an excess due to reflection at energies above the iron line. The pro le of the 6.7 keV iron line is consistent with that measured for the low-energy lines. There is evidence in the RGS data, at the 3sigma level, of spectral features that vary with source flux. The covering fraction of warm absorber gas is estimated to be 12%. Iron in the warm absorber is found to be overabundant with respect to CNO, compared to solar values
The latitudinal temperature gradient and its climate dependence as inferred from foraminiferal ÎŽ18O over the past 95 million years
The latitudinal temperature gradient is a fundamental state parameter of the climate system tied to the dynamics of heat transport and radiative transfer. Thus, it is a primary target for temperature proxy reconstructions and global climate models. However, reconstructing the latitudinal temperature gradient in past climates remains challenging due to the scarcity of appropriate proxy records and large proxyâmodel disagreements. Here, we develop methods leveraging an extensive compilation of planktonic foraminifera ÎŽ18O to reconstruct a continuous record of the latitudinal sea-surface temperature (SST) gradient over the last 95 million years (My). We find that latitudinal SST gradients ranged from 26.5 to 15.3â°C over a mean global SST range of 15.3 to 32.5â°C, with the highest gradients during the coldest intervals of time. From this relationship, we calculate a polar amplification factor (PAF; the ratio of change in >60° S SST to change in global mean SST) of 1.44 ± 0.15. Our results are closer to model predictions than previous proxy-based estimates, primarily because ÎŽ18O-based high-latitude SST estimates more closely track benthic temperatures, yielding higher gradients. The consistent covariance of ÎŽ18O values in low- and high-latitude planktonic foraminifera and in benthic foraminifera, across numerous climate states, suggests a fundamental constraint on multiple aspects of the climate system, linking deep-sea temperatures, the latitudinal SST gradient, and global mean SSTs across large changes in atmospheric CO2, continental configuration, oceanic gateways, and the extent of continental ice sheets. This implies an important underlying, internally driven predictability of the climate system in vastly different background states
The enigma of Oligocene climate and global surface temperature evolution.
Falling atmospheric CO2 levels led to cooling through the Eocene and the expansion of Antarctic ice sheets close to their modern size near the beginning of the Oligocene, a period of poorly documented climate. Here, we present a record of climate evolution across the entire Oligocene (33.9 to 23.0 Ma) based on TEX86 sea surface temperature (SST) estimates from southwestern Atlantic Deep Sea Drilling Project Site 516 (paleolatitude âŒ36°S) and western equatorial Atlantic Ocean Drilling Project Site 929 (paleolatitude âŒ0°), combined with a compilation of existing SST records and climate modeling. In this relatively low CO2 Oligocene world (âŒ300 to 700 ppm), warm climates similar to those of the late Eocene continued with only brief interruptions, while the Antarctic ice sheet waxed and waned. SSTs are spatially heterogenous, but generally support late Oligocene warming coincident with declining atmospheric CO2 This Oligocene warmth, especially at high latitudes, belies a simple relationship between climate and atmospheric CO2 and/or ocean gateways, and is only partially explained by current climate models. Although the dominant climate drivers of this enigmatic Oligocene world remain unclear, our results help fill a gap in understanding past Cenozoic climates and the way long-term climate sensitivity responded to varying background climate states
A comparison of visual and semiquantitative analysis methods for planar cardiac 123I-MIBG scintigraphy in dementia with Lewy bodies.
OBJECTIVES: Cardiac I-MIBG imaging is an established technique for the diagnosis of dementia with Lewy bodies but various analysis methods are reported in the literature. We assessed different methods in the same cohort of patients to inform best practice. PATIENTS AND METHODS: Seventeen patients with dementia with Lewy bodies, 15 with Alzheimer's disease and 16 controls were included. Planar images were acquired 20âmin and 4âh after injection. Nine operators produced heart-to-mediastinum ratios (HMRs) using freehand and 6, 7 and 8âcm diameter circular cardiac regions. Interoperator variation was measured using the coefficient of variation. HMR differences between methods were assessed using analysis of variance. Seven raters assessed the images visually. Accuracy was compared using receiver operating characteristic analysis. RESULTS: There were significant differences in HMR between region methods (P=0.006). However, with optimised cut-offs there was no significant difference in accuracy (P=0.2-1.0). The sensitivity was 65-71% and specificity 100% for all HMR methods. Variation was lower with fixed regions than freehand (P<0.001). Visual rating sensitivity and specificity were 65 and 77% on early images and 76 and 71% on delayed images. There was no significant difference in HMR between early and delayed images (P=0.4-0.7) although a greater separation between means was seen on delayed images (0.73 vs. 0.95). CONCLUSION: HMR analysis using a suitable cut-off is more accurate than visual rating. Accuracy is similar for all methods, but freehand regions are more variable and 6âcm circles easiest to place. We recommend calculating HMR using a 6âcm circular cardiac region of interest on delayed images
Blood pressure variability and cardiovascular risk in the PROspective study of pravastatin in the elderly at risk (PROSPER)
Variability in blood pressure predicts cardiovascular disease in young- and middle-aged subjects, but relevant data for older individuals are sparse. We analysed data from the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study of 5804 participants aged 70â82 years with a history of, or risk factors for cardiovascular disease. Visit-to-visit variability in blood pressure (standard deviation) was determined using a minimum of five measurements over 1 year; an inception cohort of 4819 subjects had subsequent in-trial 3 years follow-up; longer-term follow-up (mean 7.1 years) was available for 1808 subjects. Higher systolic blood pressure variability independently predicted long-term follow-up vascular and total mortality (hazard ratio per 5 mmHg increase in standard deviation of systolic blood pressure = 1.2, 95% confidence interval 1.1â1.4; hazard ratio 1.1, 95% confidence interval 1.1â1.2, respectively). Variability in diastolic blood pressure associated with increased risk for coronary events (hazard ratio 1.5, 95% confidence interval 1.2â1.8 for each 5 mmHg increase), heart failure hospitalisation (hazard ratio 1.4, 95% confidence interval 1.1â1.8) and vascular (hazard ratio 1.4, 95% confidence interval 1.1â1.7) and total mortality (hazard ratio 1.3, 95% confidence interval 1.1â1.5), all in long-term follow-up. Pulse pressure variability was associated with increased stroke risk (hazard ratio 1.2, 95% confidence interval 1.0â1.4 for each 5 mmHg increase), vascular mortality (hazard ratio 1.2, 95% confidence interval 1.0â1.3) and total mortality (hazard ratio 1.1, 95% confidence interval 1.0â1.2), all in long-term follow-up. All associations were independent of respective mean blood pressure levels, age, gender, in-trial treatment group (pravastatin or placebo) and prior vascular disease and cardiovascular disease risk factors. Our observations suggest variability in diastolic blood pressure is more strongly associated with vascular or total mortality than is systolic pressure variability in older high-risk subjects
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Prevalence, severity, and risk factors of disability among adults living with HIV accessing routine outpatient HIV care in London, United Kingdom (UK): A cross-sectional self-report study.
BACKGROUND: The study objectives were to measure disability prevalence and severity, and examine disability risk factors, among adults living with HIV in London, United Kingdom (UK). METHODS: Self-reported questionnaires were administered: World Health Organization Disability Assessment Schedule 2.0 (WHODAS), HIV Disability Questionnaire (HDQ), Equality Act disability definition (EADD), and demographic questionnaire. We calculated proportion (95% Confidence Interval; CI) of "severe" and "moderate" disability measured using EADD and WHODAS scores â„2 respectively. We measured disability severity with HDQ domain severity scores. We used demographic questionnaire responses to assess risk factors of "severe" and "moderate" disability using logistic regression analysis, and HDQ severity domain scores using linear regression analysis. RESULTS: Of 201 participants, 176 (87.6%) identified as men, median age 47 years, and 194 (96.5%) virologically suppressed. Severe disability prevalence was 39.5% (n = 79/201), 95% CI [32.5%, 46.4%]. Moderate disability prevalence was 70.5% (n = 141/200), 95% CI [64.2%, 76.8%]. Uncertainty was the most severe HDQ disability domain. Late HIV diagnosis was a risk factor for severe disability [Odds Ratio (OR) 2.71; CI 1.25, 5.87]. Social determinants of health, economic inactivity [OR 2.79; CI 1.08, 7.21] and receiving benefits [OR 2.87; CI 1.05, 7.83], were risk factors for "severe" disability. Economic inactivity [OR 3.14; CI 1.00, 9.98] was a risk factor for "moderate" disability. Economic inactivity, receiving benefits, and having no fixed abode were risk factors (Pâ€0.05) for higher HDQ severity scores in physical, mental and emotional, difficulty with day-to-day activities, and challenges to social participation domains. Personal factors, identifying as a woman and being aged <50 years, were risk factors (Pâ€0.05) for higher HDQ severity scores in mental and emotional, uncertainty, and challenges with social participation domains. CONCLUSIONS: People living with well-controlled HIV in London UK experienced multi-dimensional and episodic disability. Results help to better understand the prevalence, severity, and risk factors of disability experienced by adults living with HIV, identify areas to target interventions, and optimise health and functioning
Services just for men? Insights from a national study of the well men services pilots.
Men continue to have a lower life expectancy in most countries compared to women. Explanations of this gendered health inequality tend to focus on male risk taking, unhealthy lifestyle choices and resistance to seeking help from health services. In the period 2005-2008 the Scottish Government funded a nationwide community health promotion programme aimed at improving men's health, called Well Men Service Pilots (henceforth WMS)
Clinical prevalence of Lewy body dementia.
BACKGROUND: The prevalence of dementia with Lewy bodies (DLB) and dementia in Parkinson's disease (PDD) in routine clinical practice is unclear. Prevalence rates observed in clinical and population-based cohorts and neuropathological studies vary greatly. Small sample sizes and methodological factors in these studies limit generalisability to clinical practice. METHODS: We investigated prevalence in a case series across nine secondary care services over an 18-month period, to determine how commonly DLB and PDD cases are diagnosed and reviewed within two regions of the UK. RESULTS: Patients with DLB comprised 4.6% (95% CI 4.0-5.2%) of all dementia cases. DLB was represented in a significantly higher proportion of dementia cases in services in the North East (5.6%) than those in East Anglia (3.3%; Ï2 = 13.6, p < 0.01). DLB prevalence in individual services ranged from 2.4 to 5.9%. PDD comprised 9.7% (95% CI 8.3-11.1%) of Parkinson's disease cases. No significant variation in PDD prevalence was observed between regions or between services. CONCLUSIONS: We found that the frequency of clinical diagnosis of DLB varied between geographical regions in the UK, and that the prevalence of both DLB and PDD was much lower than would be expected in this case series, suggesting considerable under-diagnosis of both disorders. The significant variation in DLB diagnostic rates between these two regions may reflect true differences in disease prevalence, but more likely differences in diagnostic practice. The systematic introduction of more standardised diagnostic practice could improve the rates of diagnosis of both conditions
The use of CAM by women suffering from nausea and vomiting during pregnancy
BACKGROUND: Nausea and vomiting during pregnancy (NVP) affects two-thirds of pregnant women to varying degrees and over the years many modalities have been used to try to alleviate this often debilitating condition. There is a paucity of information in the literature about the use or efficacy of complementary and alternative medicine (CAM) for the treatment of this condition that affects so many women. Our primary objective was to examine the prevalence of CAM usage by women suffering from NVP. Our secondary objective was to ascertain if women had any supervision in the use of these treatments. METHODS: Women who called The Motherisk NVP helpline, were asked after the counseling session to complete a questionnaire, which included demographic data as well as information about their CAM use. RESULTS: Seventy women completed the questionnaire. 61% reported using CAM therapies, of which the three most popular were: ginger, vitamin B6 and acupressure. 21% of those who reported using CAM, had consulted CAM practitioners, 8% their physicians or pharmacists and 71% discussed the usage with family, friends and other allied health professionals. Women who did not use CAM stated they would probably use these modalities if there was more information about the safety in pregnancy. CONCLUSION: Pregnant women with NVP are mirroring the trend in the general population of the use of CAM. They are also using CAM therapies with little supervision from practitioners experienced in the use of these modalities
Outcomes with ibrutinib by line of therapy and postâibrutinib discontinuation in patients with chronic lymphocytic leukemia: Phase 3 analysis
The efficacy of ibrutinib has been demonstrated in patients with chronic lymphocytic leukemia (CLL), including as firstâline therapy. However, outcomes after ibrutinib discontinuation have previously been limited to higherârisk populations with relapsed/refractory (R/R) disease. The objective of this study was to evaluate outcomes of ibrutinibâtreated patients based on prior lines of therapy, including after ibrutinib discontinuation. Data were analyzed from two multicenter phase 3 studies of singleâagent ibrutinib: RESONATE (PCYCâ1112) in patients with R/R CLL and RESONATEâ2 (PCYCâ1115) in patients with treatmentânaive (TN) CLL without del(17p). This integrated analysis included 271 ibrutinibâtreated nonâdel(17p) patients with CLL (136 TN and 135 R/R). Median progressionâfree survival (PFS) was not reached for subgroups with 0 and 1/2 prior therapies but was 40.6 months for patients with â„3 therapies (median followâup: TN, 36âmonths; R/R, 44âmonths). Median overall survival (OS) was not reached in any subgroup. Overall response rate (ORR) was 92% in TN and 92% in R/R, with depth of response increasing over time. Adverse events (AEs) and ibrutinib discontinuation due to AEs were similar between patient groups. Most patients (64%) remain on treatment. OS following discontinuation was 9.3 months in R/R patients (median followâup 18âmonths, nâ= 51) and was not reached in TN patients (median followâup 10 months, nâ= 30). In this integrated analysis, ibrutinib was associated with favorable PFS and OS, and high ORR regardless of prior therapies in patients with CLL. The best outcomes following ibrutinib discontinuation were for patients receiving ibrutinib in earlier lines of therapy
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