Radioactive 26Al and massive stars in the Galaxy

Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane of the Galaxy. This led to the conclusion1 that massive stars throughout the Galaxy dominate the production of 26Al. On the other hand, meteoritic data show locally-produced 26Al, perhaps from spallation reactions in the protosolar disk. Furthermore, prominent gamma-ray emission from the Cygnus region suggests that a substantial fraction of Galactic 26Al could originate in localized star-forming regions. Here we report high spectral resolution measurements of 26Al emission at 1808.65 keV, which demonstrate that the 26Al source regions corotate with the Galaxy, supporting its Galaxy-wide origin. We determine a present-day equilibrium mass of 2.8 (+/-0.8) M_sol of 26Al. We use this to estimate that the frequency of core collapse (i.e. type Ib/c and type II) supernovae to be 1.9(+/- 1.1) events per century.Comment: accepted for publication in Nature, 24 pages including Online Supplements, 11 figures, 1 tabl

Labour migration, communities and perceptions of social cohesion in England

Abstract The unexpected scale of labour migration from eastern Europe to the UK following EU enlargement in 2004 was thought to pose a threat to the cohesiveness of those local communities hosting larger influxes of migrants. Nevertheless, areas rich in community capacity may have been able to incorporate migrant workers in ways that sustained social cohesion. This paper explores the effects of labour migration on residents’ perceptions of social cohesion in urban areas in England using multivariate statistical techniques. The statistical results suggest that post-enlargement migration weakened social cohesion, but that the prospects of social incorporation were better in areas with stronger community capacity. Theoretical and practical implications of the findings are discussed

The effect of leisure-time physical activity on the risk of acute myocardial infarction depending on Body Mass Index: a population-based case-control study

BACKGROUND: High body mass index (BMI) and lack of physical activity have been recognized as important risk factors for coronary heart disease. The aim of the present study was to evaluate whether leisure-time physical activity compensates for the increased risk of acute myocardial infarction associated with overweight and obesity. METHODS: Data from the SHEEP (Stockholm Heart Epidemiology Program) study were used. The SHEEP study is a large Swedish population-based case-control study, comprising 1204 male and 550 female cases, and 1538 male and 777 female controls, conducted in Stockholm County, Sweden, during the period 1992–1994. Odds ratios (OR), together with 95 % confidence intervals (95% CI), were calculated using unconditional logistic regression, as estimates of the relative risks. RESULTS: Regular leisure-time physical activity was associated with a decreased risk of myocardial infarction among lean, normal-weight and overweight subjects, but not among obese subjects. Obese (BMI ≥ 30) and physically active persons had an almost twofold risk of myocardial infarction, compared with normal-weight and sedentary persons (OR 1.85, 95% CI 1.07–3.18). The results were similar for men and women. CONCLUSION: While regular leisure-time physical activity seems to provide protection against myocardial infarction among lean, normal-weight and overweight subjects, this does not appear to be the case in obese subjects

Immune evolution from preneoplasia to invasive lung adenocarcinomas and underlying molecular features

The mechanism by which anti-cancer immunity shapes early carcinogenesis of lung adenocarcinoma (ADC) is unknown. In this study, we characterize the immune contexture of invasive lung ADC and its precursors by transcriptomic immune profiling, T cell receptor (TCR) sequencing and multiplex immunofluorescence (mIF). Our results demonstrate that anti-tumor immunity evolved as a continuum from lung preneoplasia, to preinvasive ADC, minimally-invasive ADC and frankly invasive lung ADC with a gradually less effective and more intensively regulated immune response including down-regulation of immune-activation pathways, up-regulation of immunosuppressive pathways, lower infiltration of cytotoxic T cells (CTLs) and anti-tumor helper T cells (Th), higher infiltration of regulatory T cells (Tregs), decreased T cell clonality, and lower frequencies of top T cell clones in later-stages. Driver mutations, chromosomal copy number aberrations (CNAs) and aberrant DNA methylation may collectively impinge host immune responses and facilitate immune evasion, promoting the outgrowth of fit subclones in preneoplasia into dominant clones in invasive ADC

Coxiella burnetii in Humans and Ticks in Rural Senegal

Q fever is a zoonotic disease known since 1937. The disease may be severe, causing pneumonia, hepatitis and endocarditis. Q fever agent has been described as a possible biological weapon. Animals—especially domestic cows, goats and sheep—are considered reservoirs for this infection. They are capable of sustaining the infection for long periods and excreting viable bacteria, infecting other animals and, occasionally, humans. Here we studied the distribution of Q fever in a poorly studied region, Senegal. We studied the agent of Q fever both in ticks parasitizing domestic animals and in humans (antibodies in serum, bacteria in feces, saliva and milk). We found from the studied regions the bacterium is highly prevalent in rural Senegal. Up to 37.6% of five different and most prevalent tick species may carry the bacterium. Humans living in such areas, as other mammals, may occasionally excrete Q fever agent through feces and milk

Actigraph Accelerometer-Defined Boundaries for Sedentary Behaviour and Physical Activity Intensities in 7 Year Old Children

Background: Accurate objective assessment of sedentary and physical activity behaviours during childhood is integral to the understanding of their relation to later health outcomes, as well as to documenting the frequency and distribution of physical activity within a population.Purpose: To calibrate the Actigraph GT1M accelerometer, using energy expenditure (EE) as the criterion measure, to define thresholds for sedentary behaviour and physical activity categories suitable for use in a large scale epidemiological study in young children.Methods: Accelerometer-based assessments of physical activity (counts per minute) were calibrated against EE measures (kcal.kg(-1).hr(-1)) obtained over a range of exercise intensities using a COSMED K4b(2) portable metabolic unit in 53 seven-year-old children. Children performed seven activities: lying down viewing television, sitting upright playing a computer game, slow walking, brisk walking, jogging, hopscotch and basketball. Threshold count values were established to identify sedentary behaviour and light, moderate and vigorous physical activity using linear discriminant analysis (LDA) and evaluated using receiver operating characteristic (ROC) curve analysis.Results: EE was significantly associated with counts for all non-sedentary activities with the exception of jogging. Threshold values for accelerometer counts (counts. minute(-1)) were = 3841 for light, moderate and vigorous physical activity respectively. The area under the ROC curves for discrimination of sedentary behaviour and vigorous activity were 0.98. Boundaries for light and moderate physical activity were less well defined (0.61 and 0.60 respectively). Sensitivity and specificity were higher for sedentary (99% and 97%) and vigorous (95% and 91%) than for light (60% and 83%) and moderate (61% and 76%) thresholds.Conclusion: The accelerometer cut points established in this study can be used to classify sedentary behaviour and to distinguish between light, moderate and vigorous physical activity in children of this age

Identification of novel vascular targets in lung cancer

Background: Lung cancer remains the leading cause of cancer-related death, largely owing to the lack of effective treatments. A tumour vascular targeting strategy presents an attractive alternative; however, the molecular signature of the vasculature in lung cancer is poorly explored. This work aimed to identify novel tumour vascular targets in lung cancer. Methods: Enzymatic digestion of fresh tissue followed by endothelial capture with Ulex lectin-coated magnetic beads was used to isolate the endothelium from fresh tumour specimens of lung cancer patients. Endothelial isolates from the healthy and tumour lung tissue were subjected to whole human genome expression profiling using microarray technology. Results: Bioinformatics analysis identified tumour endothelial expression of angiogenic factors, matrix metalloproteases and cellsurface transmembrane proteins. Predicted novel tumour vascular targets were verified by RNA-seq, quantitative real-time PCR analysis and immunohistochemistry. Further detailed expression profiling of STEAP1 on 82 lung cancer patients confirmed STEAP1 as a novel target in the tumour vasculature. Functional analysis of STEAP1 using siRNA silencing implicates a role in endothelial cell migration and tube formation. Conclusions: The identification of cell-surface tumour endothelial markers in lung is of interest in therapeutic antibody and vaccine development

Differential Effects of Aging on Fore– and Hindpaw Maps of Rat Somatosensory Cortex

Getting older is associated with a decline of cognitive and sensorimotor abilities, but it remains elusive whether age-related changes are due to accumulating degenerational processes, rendering them largely irreversible, or whether they reflect plastic, adaptational and presumably compensatory changes. Using aged rats as a model we studied how aging affects neural processing in somatosensory cortex. By multi-unit recordings in the fore- and hindpaw cortical maps we compared the effects of aging on receptive field size and response latencies. While in aged animals response latencies of neurons of both cortical representations were lengthened by approximately the same amount, only RFs of hindpaw neurons showed severe expansion with only little changes of forepaw RFs. To obtain insight into parallel changes of walking behavior, we recorded footprints in young and old animals which revealed a general age-related impairment of walking. In addition we found evidence for a limb-specific deterioration of the hindlimbs that was not observed in the forelimbs. Our results show that age-related changes of somatosensory cortical neurons display a complex pattern of regional specificity and parameter-dependence indicating that aging acts rather selectively on cortical processing of sensory information. The fact that RFs of the fore- and hindpaws do not co-vary in aged animals argues against degenerational processes on a global scale. We therefore conclude that age-related alterations are composed of plastic-adaptive alterations in response to modified use and degenerational changes developing with age. As a consequence, age-related changes need not be irreversible but can be subject to amelioration through training and stimulation