286 research outputs found
Terrace reconstruction and long profile projection: a case study from the Solent river system near Southampton, England
River terrace sequences are important frameworks for archaeological evidence and as
such it is important to produce robust correlations between what are often fragmentary
remnants of ancient terraces. This paper examines both conceptual and practical issues
related to such correlations, using a case study from the eastern part of the former Solent
River system near Southampton, England. In this region two recent terrace schemes
have been constructed using different data to describe the terrace deposits: one based
mainly on terrace surfaces; the other on gravel thicknesses, often not recording the
terrace surface itself. The utility of each of these types of data in terrace correlation is
discussed in relation to the complexity of the record, the probability of post-depositional
alteration of surface sediments and comparison of straight-line projections with modern
river long profiles. Correlation using age estimates is also discussed, in relation to
optically-stimulated luminescence dating of sand lenses within terrace gravels in this
region during the PASHCC project. It is concluded that the need for replication at single
sites means that this approach has limited use for correlative purposes, although dating
of sediments is important for understanding wider landscape evolution and patterns of
human occupation
Prevalence, incidence, and associated risk factors of tuberculosis in children with HIV living in the UK and Ireland (CHIPS): a cohort study
BACKGROUND: Tuberculosis is the most common serious co-infection in people living with HIV worldwide, but little is known about its incidence in HIV-infected children living in high-resource settings with low tuberculosis prevalence. We aimed to assess the incidence and prevalence of tuberculosis in children with HIV living in the UK and Ireland to understand rates, risk factors, and outcomes of the disease in this group. METHODS: We did an analysis of children enrolled in CHIPS, an observational multicentre cohort of children receiving HIV care in the UK and Ireland. We assessed characteristics and prevalence of tuberculosis at baseline, measured incidence of disease through the follow-up period using the CHIPS database, and calculated associated risk factors in these children with multivariable logistic and Cox regression models. FINDINGS: Between Jan 1, 1996, to Sept 18, 2014, data for 1848 children with 14 761 years of follow-up were reported to CHIPS. 57 (3%) children were diagnosed with tuberculosis: 29 children had tuberculosis at presentation (prevalent tuberculosis) and 29 had the disease diagnosed during follow-up (incident tuberculosis), including one child with recurrent tuberculosis events. Median age at diagnosis was 9 years (IQR 5-12). 25 (43%) children had pulmonary tuberculosis, 24 (41%) had extrapulmonary tuberculosis with or without pulmonary involvement, and the remainder (n=9; 16%) had unspecified-site tuberculosis. The overall incidence rate for the follow-up period was 196 cases per 100 000 person-years (95% CI 137-283). In our multivariable model, tuberculosis at presentation was associated with more severe WHO immunological stage at baseline (odds ratio 0·25, 95% CI 0·08-0·74; p=0·0331; for none vs severe) and being born abroad (odds ratio 0·28, 0·10-0·73; p=0·0036; for UK and Ireland vs abroad). Incident tuberculosis was associated with time-updated more severe WHO immunological stage (hazard ratio 0·15, 95% CI 0·06-0·41; p=0·0056; for none vs severe) and older age at baseline (1·11, 0·47-2·63; p=0·0027; for age >10 years vs 5-9 years). INTERPRETATION: Tuberculosis rates in HIV-infected children in the UK and Ireland were higher than those reported in the general paediatric population. Further study is warranted of tuberculosis screening and preventive treatment for children at high-risk of this disease to avoid morbidity and mortality in this population. FUNDING: NHS England, PENTA Foundation
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Does designation as a UNESCO World Heritage Site influence tourist evaluation of a local destination?
The purpose of this study is to explore whether the UNESCO World Heritage Site (WHS) designation affects tourists’ evaluation of the local destination hosting the site, building on a large sample of about 0.8 million tourists who visited Italy over the period 1997-2015. We find that the inscription onto the UNESCO World Heritage List exerts surprisingly a negative effect on the overall evaluation of the destination and also on the evaluation of its artistic assets though the magnitude of the latter is lower. The effect is heterogeneous across visitors, depending on evaluation levels, as well as origin/destinations and demographics. Nonetheless, the presence of multiple WHSs in the same destination tends to increase evaluation suggesting that destination stakeholders with previous experience in dealing with WHS designations are better equipped to manage the complicated relationship between tourism and preservation. Managerial and policy-making implications are discussed
History of climate modeling
The history of climate modeling begins with conceptual models, followed in the 19th century by mathematical models of energy balance and radiative transfer, as well as simple analog models. Since the 1950s, the principal tools of climate science have been computer simulation models of the global general circulation. From the 1990s to the present, a trend toward increasingly comprehensive coupled models of the entire climate system has dominated the field. Climate model evaluation and intercomparison is changing modeling into a more standardized, modular process, presenting the potential for unifying research and operational aspects of climate science. WIREs Clim Change 2011 2 128–139 DOI: 10.1002/wcc.95 For further resources related to this article, please visit the WIREs websitePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79438/1/95_ftp.pd
Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence - Postmortem evaluation
In this work, a non-commercial triaxial geometry energy dispersive X-ray Fluorescence (EDXRF) setup and a benchtop mu-XRF system were used to identify postmortem contamination in buried bones. For two of the individuals, unusually high concentrations of Cu and Pb, but also Zn (in one individual) were observed. The pigments of the burial shroud coverings have been identified as the source of contamination.Accurate and precise quantitative results were obtained by nondestructive process using fundamental parameters method taking into account the matrix absorption effects.A total of 30 bones from 13 individuals, buried between the mid-XVlllth to early XIXth centuries, were analyzed to study the elemental composition and elemental distribution. The bones were collected from a church in Almada (Portugal), called Ermida do Espirito Santo, located near the Tagus River and at the sea neighbourhood.The triaxial geometry setup was used to quantify Ca, Fe, Cu, Zn, Br, Sr and Pb of powder pressed bone pellets (n=9 for each bone). Cluster analysis was performed considering the elemental concentrations for the different bones. There was a clear association between some bones regarding Fe, Cu, Zn, Br and Pb content but not a categorization between cortical and trabecular bones. The elemental distribution of Cu, Zn and Pb were assessed by the benchtop p.-analysis, the M4 Tornado, based on a polycapillary system which provides multi-elemental 2D maps. The results showed that contamination was mostly on the surface of the bone confirming that it was related to the burial shroud covering the individuals
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
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