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1.
Public Health ; 225: 299-304, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37956642

RESUMO

OBJECTIVES: Given the predicted rise in dementia prevalence around the world, targeting modifiable risk factors (often lifestyle related) is a priority. This work sought to understand the role of physical inactivity (PI) as a modifiable risk factor for dementia. STUDY DESIGN: Ecological study using globally available ecological data (both 2010 and 2016) from 192 countries. METHODS: Age-standardised PI prevalence and dementia prevalence data were accessed from the World Health Organisation (WHO) and the Global Burden of Disease Study. Linear regression was used to assess the relationship between PI and dementia, with stratified analyses used to further explore the impact of sex, WHO region, and World Bank income group on the relationship. RESULTS: Linear regression showed a positive association between inactivity and dementia prevalence in 2010 (b = 1.38 [95% confidence interval {CI}: 0.04, 2.71] P = 0.044) and 2016 (coefficient = 2.52 [95% CI: 1.07, 3.96] P = 0.0007). Sub-group analyses of sex-specific data showed the strength of the relationship was stronger in men than in women. Rates of both dementia and inactivity rose with increasing world income group. CONCLUSIONS: This analysis of global data indicates the presence of a positive relationship between prevalence of PI and dementia prevalence, which has increased in strength with time, and is stronger in men than in women. This highlights the importance of public health interventions on a global scale to reduce the percentage of the population failing to reach or exceed the recommended physical activity guidelines.


Assuntos
Demência , Comportamento Sedentário , Masculino , Humanos , Feminino , Fatores de Risco , Exercício Físico , Renda , Demência/epidemiologia , Prevalência , Saúde Global
2.
Neuroimage ; 215: 116816, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32276064

RESUMO

Neural responses to auditory surprise are typically studied with highly unexpected, disruptive sounds. Consequently, little is known about auditory prediction in everyday contexts that are characterized by fine-grained, non-disruptive fluctuations of auditory surprise. To address this issue, we used IDyOM, a computational model of auditory expectation, to obtain continuous surprise estimates for a set of newly composed melodies. Our main goal was to assess whether the neural correlates of non-disruptive surprising sounds in a musical context are affected by musical expertise. Using magnetoencephalography (MEG), auditory responses were recorded from musicians and non-musicians while they listened to the melodies. Consistent with a previous study, the amplitude of the N1m component increased with higher levels of computationally estimated surprise. This effect, however, was not different between the two groups. Further analyses offered an explanation for this finding: Pitch interval size itself, rather than probabilistic prediction, was responsible for the modulation of the N1m, thus pointing to low-level sensory adaptation as the underlying mechanism. In turn, the formation of auditory regularities and proper probabilistic prediction were reflected in later components: The mismatch negativity (MMNm) and the P3am, respectively. Overall, our findings reveal a hierarchy of expectations in the auditory system and highlight the need to properly account for sensory adaptation in research addressing statistical learning.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Percepção Auditiva/fisiologia , Magnetoencefalografia/métodos , Motivação/fisiologia , Música/psicologia , Estimulação Acústica/métodos , Estimulação Acústica/psicologia , Adulto , Antecipação Psicológica/fisiologia , Eletroencefalografia/métodos , Feminino , Previsões , Humanos , Masculino , Adulto Jovem
3.
J Public Health (Oxf) ; 42(2): 325-332, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-31220295

RESUMO

BACKGROUND: The influence of sedentary time and habitual physical activity on the bone health of middle aged adults is not well known. METHODS: Bone mineral density (BMD) and hip bone geometry were evaluated in 214 men (n = 92) and women (n = 112) aged 62.1 ± 0.5 years from the Newcastle Thousand Families Study birth cohort. Accelerometry was used to measure physical activity (PA) and sedentary time over 4 days. Regression models were adjusted for clinical risk factor covariates. RESULTS: Men were more sedentary than women (P < 0.05), and sedentary time was negatively associated with spine BMD in men, with 84 minutes more sedentary time corresponding to 0.268 g.cm-2 lower BMD (ß = -0.268; P = 0.017). In men, light PA and steps/day were positively associated with bone geometry and BMD. Steps/day was positively associated with bone geometry and femur BMD in women, with a positive difference of 1415 steps/day corresponding to 0.232 g.cm-2 greater BMD (ß = 0.232, P = 0.015). CONCLUSIONS: Sedentary time was unfavourably associated with bone strength in men born in North East England at age 62 years. Higher volumes of light PA, and meeting the public health daily step recommendations (10 000 steps/day) was positively associated with bone health in both sexes.


Assuntos
Exercício Físico , Comportamento Sedentário , Absorciometria de Fóton , Adulto , Densidade Óssea , Inglaterra/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Osteoporos Int ; 30(4): 829-836, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30623213

RESUMO

Obesity increases the likelihood of prevalent vertebral fracture (VF) in men and women at age 62 years. The higher absolute bone mineral density (BMD) observed in obese individuals is disproportionate to body weight, and this may partly explain the greater prevalence of VF in this group. INTRODUCTION: Obesity is a global epidemic, and there remains uncertainty over the effect of obesity on skeletal health, particularly in the context of osteoporosis. The aim of this study was to investigate associations of body mass index (BMI) and obesity with BMD and prevalent VF in men and women aged 62 years. METHODS: Three hundred and forty-two men and women aged 62.5 ± 0.5 years from the Newcastle Thousand Families Study birth cohort underwent DXA evaluations of femoral neck and lumbar spine BMD and of the lateral spine for vertebral fracture assessment. RESULTS: The likelihood of prevalent VF was significantly increased in men when compared to women (OR = 2.7, p < 0.001, 95% Cl 1.7-4.4). As BMI increased in women, so did the likelihood of prevalent any-grade VF (OR = 1.09, p = 0.006, 95% CI 1.02-1.17). Compared to normal weight women, obese women were more likely to have at least one VF (OR = 2.65, p = 0.025, CI 1.13-6.20) and at least one grade 1 vertebral deformity (OR = 4.39, p = 0.005, CI 1.57-12.28). Obese men were more likely to have a grade 2 and/or grade 3 VF compared to men of normal weight (OR = 3.36, p = 0.032, CI 1.11-10.16). In men and women, BMI was negatively associated with femoral neck BMD/weight (R = - 0.65, R = - 0.66, p < 0.001) and lumbar spine BMD/weight (R = - 0.66, R - 0.60, p < 0.001). CONCLUSIONS: Obesity appears to be a risk factor for prevalent VF, and although absolute BMD is higher in obese individuals, this does not appear commensurate to their increased body weight.


Assuntos
Densidade Óssea/fisiologia , Obesidade/complicações , Fraturas por Osteoporose/etiologia , Fraturas da Coluna Vertebral/etiologia , Absorciometria de Fóton/métodos , Idoso , Índice de Massa Corporal , Estudos de Coortes , Estudos Transversais , Inglaterra/epidemiologia , Feminino , Colo do Fêmur/fisiopatologia , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/fisiopatologia , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/fisiopatologia , Prevalência , Fatores de Risco , Fatores Sexuais , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/fisiopatologia
5.
Phys Rev Lett ; 123(14): 143604, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31702208

RESUMO

We implement a general imaging method by measuring the complex degree of coherence using linear optics and photon number resolving detectors. In the absence of collective or entanglement-assisted measurements, our method is optimal over a large range of practically relevant values of the complex degree of coherence. We measure the size and position of a small distant source of pseudothermal light, and show that our method outperforms the traditional imaging method by an order of magnitude in precision. Finally, we show that a lack of photon-number resolution in the detectors has only a modest detrimental effect on measurement precision and simulate imaging using the new and traditional methods with an array of detectors, showing that the new method improves both image clarity and contrast.

6.
Clin Radiol ; 74(10): 816.e9-816.e17, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31375261

RESUMO

AIM: To determine cumulative scan frequencies and estimate lens dose for paediatric computed tomography (CT) head examinations in the context of potential cataract risk. MATERIALS AND METHODS: The cumulative number of head-region CT examinations among a cohort of 410,997 children and young adults who underwent CT in the UK between 1985 and 2014 was calculated. Images from a sample of these head examinations (n=668) were reviewed to determine the level of eye inclusion. Lens dose per scan was estimated using the computer program, NCICT V1.0, for different levels of eye inclusion and exposure settings typical of past and present clinical practice. RESULTS: In total 284,878 patients underwent 448,108 head-region CT examinations. The majority of patients (72%) had a single recorded head-region examination. A small subset (∼1%, n=2,494) underwent ≥10 examinations, while 0.1% (n=387) underwent ≥20. The lens was included within the imaged region for 57% of reviewed routine head examinations. In many cases, this appeared to be intentional, i.e. protocol driven. In others, there appeared to have been an attempt to exclude the eyes through gantry angulation. Estimated lens doses were 20-75 mGy (mean: 47 mGy) where the eye was fully included within the examination range and 2-7 mGy (mean: 3.1 mGy) where the lens was fully excluded. Potential cumulative lens doses ranged from ∼3 mGy to ∼4,700 mGy, with 2,335 patients potentially receiving >500 mGy. CONCLUSION: The majority of young people will receive cumulative lens doses well below 500 mGy, meaning the risk of cataract induction is likely to be very small.


Assuntos
Cabeça/diagnóstico por imagem , Cristalino/efeitos da radiação , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Adolescente , Catarata/etiologia , Catarata/prevenção & controle , Criança , Pré-Escolar , Estudos de Coortes , Relação Dose-Resposta à Radiação , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Posicionamento do Paciente , Exposição à Radiação/efeitos adversos , Adulto Jovem
7.
BMC Med ; 16(1): 111, 2018 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-30032726

RESUMO

BACKGROUND: Most evidence about what works in transitional care comes from small studies in single clinical specialties. We tested the hypothesis that exposures to nine recommended features of transitional healthcare were associated with better outcomes for young people with long-term conditions during transition from child-centred to adult-oriented health services. METHODS: This is a longitudinal, observational cohort study in UK secondary care including 374 young people, aged 14-18.9 years at recruitment, with type 1 diabetes (n = 150), cerebral palsy (n = 106) or autism spectrum disorder with an associated mental health problem (n = 118). All were pre-transfer and without significant learning disability. We approached all young people attending five paediatric diabetes centres, all young people with autism spectrum disorder attending four mental health centres, and randomly selected young people from two population-based cerebral palsy registers. Participants received four home research visits, 1 year apart and 274 participants (73%) completed follow-up. Outcome measures were Warwick Edinburgh Mental Wellbeing Scale, Mind the Gap Scale (satisfaction with services), Rotterdam Transition Profile (Participation) and Autonomy in Appointments. RESULTS: Exposure to recommended features was 61% for 'coordinated team', 53% for 'age-banded clinic', 48% for 'holistic life-skills training', 42% for 'promotion of health self-efficacy', 40% for 'meeting the adult team before transfer', 34% for 'appropriate parent involvement' and less than 30% for 'written transition plan', 'key worker' and 'transition manager for clinical team'. Three features were strongly associated with improved outcomes. (1) 'Appropriate parent involvement', example association with Wellbeing (b = 4.5, 95% CI 2.0-7.0, p = 0.001); (2) 'Promotion of health self-efficacy', example association with Satisfaction with Services (b = - 0.5, 95% CI - 0.9 to - 0.2, p = 0.006); (3) 'Meeting the adult team before transfer', example associations with Participation (arranging services and aids) (odds ratio 5.2, 95% CI 2.1-12.8, p < 0.001) and with Autonomy in Appointments (average 1.7 points higher, 95% CI 0.8-2.6, p < 0.001). There was slightly less recruitment of participants from areas with greater socioeconomic deprivation, though not with respect to family composition. CONCLUSIONS: Three features of transitional care were associated with improved outcomes. Results are likely to be generalisable because participants had three very different conditions, attending services at many UK sites. Results are relevant for clinicians as well as for commissioners and managers of health services. The challenge of introducing these three features across child and adult healthcare services, and the effects of doing so, should be assessed.


Assuntos
Serviços de Saúde/tendências , Adolescente , Protocolos Clínicos , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino
8.
Diabet Med ; 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-29852520

RESUMO

AIM: We hypothesized that participant well-being and satisfaction with services would be positively associated with a satisfactory clinical course during transition from child to adult health care. METHODS: Some 150 young people with Type 1 diabetes mellitus from five diabetes units in England were recruited to a longitudinal study of transition. Each young person was visited at home four times by a research assistant; each visit was 1 year apart. Satisfaction with services (Mind the Gap; MTG) and mental well-being (Warwick-Edinburgh Mental Well-being Scale; WEMWBS) were captured. Change in HbA1c , episodes of ketoacidosis, clinic and retinal screening attendance were used to assess clinical course. In total, 108 of 150 (72%) young people had sufficient data for analysis at visit 4. RESULTS: Mean age at entry was 16 years. By visit 4, 81.5% had left paediatric healthcare services. Median HbA1c increased significantly (P = 0.01) from 69 mmol/mol (8.5%) at baseline to 75 mmol/mol (9.0%) at visit 4. WEMWBS scores were comparable with those in the general population at baseline and were stable over the study period. MTG scores were also stable. By visit 4, some 32 individuals had a 'satisfactory' and 76 a 'suboptimal' clinical course. There were no significant differences in average WEMWBS and MTG scores between the clinical course groups (P = 0.96, 0.52 respectively); nor was there a significant difference in transfer status between the clinical course groups. CONCLUSIONS: The well-being of young people with diabetes and their satisfaction with transition services are not closely related to their clinical course. Investigating whether innovative psycho-educational interventions can improve the clinical course is a research priority.

9.
J Public Health (Oxf) ; 40(3): 582-590, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29190364

RESUMO

Background: Parents tend to visually assess children to determine their weight status and typically underestimate child body size. A visual tool may aid parents to more accurately assess child weight status and so support strategies to reduce childhood overweight. Body image scales (BIS) are visual images of people ranging from underweight to overweight but none exist for children based on UK criteria. Our aim was to develop sex- and age-specific BIS for children, based on British growth reference (UK90) criteria. Methods: BIS were developed using 3D surface body scans of children, their associated weight status using UK90 criteria from height and weight measurements, and qualitative work with parents and health professionals. Results: Height, weight and 3D body scans were collected (211: 4-5 years; 177: 10-11 years). Overall, 12 qualitative sessions were held with 37 participants. Four BIS (4-5-year-old girls and boys, 10-11-year-old girls and boys) were developed. Conclusions: This study has created the first sex- and age-specific BIS, based on UK90 criteria. The BIS have potential for use in child overweight prevention and management strategies, and in future research. This study also provides a protocol for the development of further BIS appropriate to other age groups and ethnicities.


Assuntos
Imagem Corporal , Obesidade Infantil/prevenção & controle , Fatores Etários , Estatura , Imagem Corporal/psicologia , Peso Corporal , Pré-Escolar , Feminino , Humanos , Masculino , Obesidade Infantil/diagnóstico , Padrões de Referência , Fatores Sexuais , Reino Unido
10.
Public Health ; 164: 72-81, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30212722

RESUMO

OBJECTIVES: Refugees are most vulnerable to mental health problems of all migrant groups, and an understanding of the role of postdisplacement social factors in refugee emotional well-being can help to shape the future interventions for this group. We aimed to investigate the effect of social determinants, such as employment, language ability and accommodation, on mental health in refugees in the UK. STUDY DESIGN: This prospective longitudinal cohort study was set in the UK. The study population of new UK refugees was drawn from an existing data set of the Longitudinal Survey of New Refugees (n = 5678), in which all new UK refugees (2005-2007) were sent a postal questionnaire at four time points across 2 years. METHODS: Ordered logistic regression models were used to evaluate associations between social determinants and the dependent variables, emotional well-being or change in emotional well-being, using a question from the Short Form-36 Health Survey Questionnaire. RESULTS: Refugees who were unemployed in the UK, could not speak English well or were unsatisfied with their accommodation had significantly higher odds of poorer emotional well-being in the cross-sectional analysis (P < 0.05 at all time points measured). CONCLUSIONS: Postdisplacement social factors, including language ability, employment status and accommodation satisfaction, were important determinants of refugee emotional well-being. Changes in these social determinants have the potential to improve refugee mental health, making them legitimate, modifiable targets for important public health interventions. Accounting for this, further research into how to improve refugee well-being is crucial given the increase in refugee numbers around the developed world.


Assuntos
Saúde Mental/estatística & dados numéricos , Refugiados/psicologia , Determinantes Sociais da Saúde , Adolescente , Adulto , Idoso , Feminino , Inquéritos Epidemiológicos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Refugiados/estatística & dados numéricos , Reino Unido , Adulto Jovem
11.
Int J Obes (Lond) ; 41(7): 1042-1047, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28293017

RESUMO

BACKGROUND: Sedentary time (ST) has been reported to have a range of negative health effects in adults, however, the evidence for such effects among children and adolescents is sparse. The primary aim of the study was to examine associations between changes in sedentary behavior (time and fragmentation) and changes in adiposity across childhood and adolescence. METHODS: Participants were recruited as part of the Gateshead Millennium Study. Measures were taken at age 7 (n=502), 9 (n=506), 12 (n=420) and 15 years (n=306). Participants wore an ActiGraph GT1M and accelerometer epochs were 'sedentary' when recorded counts were ⩽25 counts per 15 s. ST was calculated and fragmentation (SF) was assessed by calculating the number of sedentary bouts per sedentary hour. Associations of changes in ST and SF with changes in adiposity (body mass index (BMI), and fat mass index (FMI)) were examined using bivariate linear spline models. RESULTS: Increasing ST by 1% per year was associated with an increase in BMI of 0.08 kg m-2 per year (95% CI: 0.06-0.10; P<0.001) and FMI of 0.15 kg m-2 per year (0.11-0.19; P<0.001). Change in SF was associated with BMI and FMI (P<0.001). An increase of 1 bout per sedentary hour per year (that is, sedentary time becoming more fragmented) was associated with an increase in BMI of 0.07 kg m-2 per year (0.06-0.09; P<0.001) and an increase in FMI of 0.14 kg m-2 per year (0.10-0.18; P<0.001) over the 8 years period. However, an increase in SF between 9-12 years was associated with a 0.09 kg m-2 per year decrease in BMI (-0.18-0.00; P=0.046) and 0.11 kg m-2 per year decrease in FMI (-0.22-0.00; P=0.049). CONCLUSIONS: Increased ST and increased SF from 7-15 years were associated with increased adiposity. This is the first study to show age-specific associations between change in objectively measured sedentary behavior and adiposity after adjustment of moderate-to-vigorous-intensity physical activity in children and adolescents. The study suggests that, targeting sedentary behavior for obesity prevention may be most effective during periods in which we see large increases in ST.


Assuntos
Adiposidade , Comportamento do Adolescente , Comportamento Infantil , Exercício Físico/fisiologia , Comportamento Sedentário , Acelerometria/estatística & dados numéricos , Adolescente , Fatores Etários , Índice de Massa Corporal , Criança , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Obesidade Infantil/prevenção & controle , Comportamento de Redução do Risco , Reino Unido , População Urbana
12.
Phys Rev Lett ; 116(24): 241105, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367381

RESUMO

Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration, and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) until the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.

13.
Eur J Cancer Care (Engl) ; 25(3): 428-39, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26391419

RESUMO

It is rare for studies to approach psychosocial outcomes of childhood cancer in a holistic and explanatory way. Doing so would enable a greater understanding of why and in what way a young person's life may be affected by cancer. This qualitative study aimed to explore the views of childhood cancer survivors (CCS) regarding how they perceive their illness to have influenced them and their subsequent lives. Twelve CCS with a median age of 23 years old took part in either a focus group or a telephone interview. Data were analysed using thematic analysis. The main themes were altered life perspectives, perceptions of self and lasting effects on relationships. Through these themes, the survivors gave insight into how their experience had influenced their views and how this had impacted on different areas of their lives. Although positive aspects were discussed, enduring issues were reported by some. Findings suggest that despite high levels of achievement, some survivors may still benefit from further information and support especially in relation to relationships and fertility. This study will inform the development of a questionnaire aiming to collect important information on the many factors which may influence long-term psychosocial outcomes in CCS.


Assuntos
Adultos Sobreviventes de Eventos Adversos na Infância/psicologia , Neoplasias/psicologia , Adaptação Psicológica , Adolescente , Adulto , Idade de Início , Atitude Frente a Saúde , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Infertilidade/psicologia , Intenção , Relações Interpessoais , Acontecimentos que Mudam a Vida , Masculino , Pesquisa Qualitativa , Autoimagem , Adulto Jovem
14.
J Radiol Prot ; 36(4): R131-R144, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27893455

RESUMO

A large number of investigations into the radiation doses from x-ray guided interventional cardiology procedures in children have been carried out in recent years. A review was conducted of these studies, gathering data on kerma area product (P KA), fluoroscopic screening time (FT), air kerma, and estimates of effective dose and organ doses. The majority of studies focus on P KA and FT with no estimation of dose to the patient. A greater than ten-fold variation in average P KA was found between different studies, even where data were stratified by patient age or weight. Typical values of P KA were 0.6-10 Gy · cm2 (<1 year/10 kg), 1.5-30 Gy · cm2 (1-5 years), 2-40 Gy · cm2 (5-10 years), 5-100 Gy · cm2 (10-16 years) and 10-200 Gy · cm2 (>16 years). P KA was lowest for heart biopsy (0.3-10 Gy · cm2 for all ages combined) and atrial septostomy (0.4-4.0 Gy · cm2), and highest for pulmonary artery angioplasty (1.5-35 Gy · cm2) and right ventricular outflow tract dilatation (139 Gy · cm2). Most estimates of patient dose were in the form of effective dose (typically 3-15 mSv) which is of limited usefulness in individualised risk assessment. Few studies estimated organ doses. Despite advances in radiation protection, recent publications have reported surprisingly large doses, as represented by P KA and air kerma. There is little indication of a fall in these dose indicators over the last 15 years. Nor is there much suggestion of a fall in doses associated with the use of flat panel detectors, as opposed to image intensifiers. An assessment of the impact of radiation dose in the context of overall patient outcome is required.


Assuntos
Cardiologia , Doses de Radiação , Proteção Radiológica/métodos , Radiografia Intervencionista , Criança , Humanos , Medição de Risco
15.
Phys Rev Lett ; 115(11): 111101, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26406816

RESUMO

In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3} GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.

16.
Nature ; 458(7238): 607-9, 2009 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-19340076

RESUMO

Antiparticles account for a small fraction of cosmic rays and are known to be produced in interactions between cosmic-ray nuclei and atoms in the interstellar medium, which is referred to as a 'secondary source'. Positrons might also originate in objects such as pulsars and microquasars or through dark matter annihilation, which would be 'primary sources'. Previous statistically limited measurements of the ratio of positron and electron fluxes have been interpreted as evidence for a primary source for the positrons, as has an increase in the total electron+positron flux at energies between 300 and 600 GeV (ref. 8). Here we report a measurement of the positron fraction in the energy range 1.5-100 GeV. We find that the positron fraction increases sharply over much of that range, in a way that appears to be completely inconsistent with secondary sources. We therefore conclude that a primary source, be it an astrophysical object or dark matter annihilation, is necessary.

17.
Br J Cancer ; 111(9): 1814-23, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25051410

RESUMO

BACKGROUND: Earlier studies have shown raised risks of leukaemia and non-Hodgkin lymphoma in children, teenagers and young adults resident either at birth or diagnosis in Seascale. Some increases in cancer risk in these age groups have also been noted among those living around Dounreay. We aimed to update previous analyses relating to areas close to these nuclear installations by considering data from an additional 16 years of follow-up. METHODS: Cross-sectional analyses compared cancer incidence rates for 1963-2006 among those aged 0-24 years at diagnosis living in geographically specified areas around either Sellafield or Dounreay with general population rates. Cancer incidence for the period 1971-2006 among the cohort of Cumbrian births between 1950 and 2006 was compared to national incidence for 1971-2006 using person-years analysis. Cancer among those born in the postcode sector closest to Dounreay was compared with that among those born in the three adjoining postcode sectors. Analyses considered both cancer overall and ICD-O-3 defined diagnostic subgroups including leukaemia, central nervous system tumours and other malignancies. RESULTS: Apart from previously reported raised risks, no new significantly increased risks for cancer overall or any diagnostic subgroup were found among children or teenagers and young adults living around either nuclear installation. Individuals born close to the installations from 1950 to 2006 were not shown to be at any increased risk of cancer during the period 1971 to date. CONCLUSIONS: Analysis of recent data suggests that children, teenagers and young adults currently living close to Sellafield and Dounreay are not at an increased risk of developing cancer. Equally, there is no evidence of any increased cancer risk later in life among those resident in these areas at birth.


Assuntos
Neoplasias Induzidas por Radiação/epidemiologia , Reatores Nucleares , Cinza Radioativa/efeitos adversos , Características de Residência , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Seguimentos , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Neoplasias Induzidas por Radiação/etiologia , Prognóstico , Fatores de Risco , Reino Unido/epidemiologia , Adulto Jovem
18.
Epidemiol Infect ; 142(2): 388-98, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23657202

RESUMO

The aim of this study was to investigate spatial variation in risk of hospitalization in childhood pneumonia and empyema in the North of England and associated risk factors. Data on childhood (0-14 years) hospital admissions with a diagnosis pneumonia or empyema were linked to postcode districts. Bayesian conditional autoregressive models were used to evaluate spatial variation and the relevance of specific spatial covariates in an area-based study using postcode as the areal unit. There was a sixfold variation in the risk of hospitalization due to pneumonia across the study region. Variation in risk was associated with material deprivation, Child Well-being Index (CWI) health domain score, number of children requiring local authority support, and distance to hospital. No significant spatial variation in risk for empyema was found.


Assuntos
Empiema Pleural/epidemiologia , Hospitalização/estatística & dados numéricos , Pneumonia/epidemiologia , Adolescente , Criança , Pré-Escolar , Inglaterra/epidemiologia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Pneumonia/terapia , Pobreza/estatística & dados numéricos , Fatores de Risco , Análise Espacial
19.
East Mediterr Health J ; 20(10): 589-95, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25356689

RESUMO

The prevalence of obesity among adults in Saudi Arabia increased from 22% in 1990-1993 to 36% in 2005, and future projections of the prevalence of adult obesity are needed by health policy-makers. In a secondary analysis of published data, a number of assumptions were applied to estimate the trends and projections in the age-and sex-specific prevalence of adult obesity in Saudi Arabia over the period 1992-2022. Five studies conducted between 1989 and 2005 were eligible for inclusion, using body mass index (BMI) ≥ 30 kg/m(2) to define obesity. The overall prevalence of obesity was projected to increase from around 12% in 1992 to 41% by 2022 in men, and from 21% to 78% in women. Women had much higher projected prevalence than men, particularly in the age groups 35-44, 45-54 and 55-64 years. Effective national strategies are needed to reduce or halt the projected rise in obesity prevalence.


Assuntos
Ingestão de Energia/fisiologia , Política de Saúde , Obesidade/prevenção & controle , Comportamento Sedentário , Adulto , Distribuição por Idade , Dieta/efeitos adversos , Dieta/tendências , Feminino , Previsões , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/etiologia , Prevalência , Arábia Saudita/epidemiologia , Distribuição por Sexo
20.
Br J Cancer ; 108(11): 2339-45, 2013 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-23652301

RESUMO

BACKGROUND: Despite marked improvements in childhood leukaemia survival, 20% still die within 5 years of diagnosis. The aim of this study was to evaluate the relationship between socioeconomic status, as assessed by paternal occupation at birth, and survival from childhood leukaemia in children, using data from the Northern Region Young Persons Malignant Disease Registry. METHODS: All 1007 cases of leukaemia in children aged 0-14 years, diagnosed between 1968 and 2010 and registered with the Registry were studied. Paternal occupational social class at the time of the child's birth was obtained and analysed in relation to survival using Cox-proportional regression. RESULTS: Compared with the most advantaged group (I/II), those in the middle group (IIIN/M) had a 68% increased risk of death, while those in the least advantaged group (IV/V) had 86% higher risk for acute lymphoblastic leukaemia. While the survival advantage of children in class I/II was apparent from the time of diagnosis, survival for children in groups IIIN/M and IV/V were comparable until 3-4 years after diagnosis, when they began to minimally diverge. CONCLUSION: The existence of such socioeconomic disparities cannot be attributed to accessibility to health care in the United Kingdom. Further research into the likely factors underlying these disparities is required.


Assuntos
Leucemia/mortalidade , Adolescente , Adulto , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Humanos , Lactente , Recém-Nascido , Leucemia/economia , Leucemia/epidemiologia , Masculino , Prognóstico , Estudos Retrospectivos , Classe Social , Adulto Jovem
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