339 research outputs found

    The Holocene Geoarchaeology of the Desert Nile in Northern Sudan

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    Invited Paper Forty years ago Colin Renfrew declared that "every archaeological problem starts as a problem in geoarchaeology" (Renfrew, 1976 p. 2). With this assertion in mind, this paper draws upon the findings from field research in two sectors of the Nile Valley of Northern Sudan dedicated to the exploration of human-environment interactions during the middle and late Holocene. This part of the Nile corridor contains a rich cultural record and an exceptionally well preserved Holocene fluvial archive. A distinctive feature of these records is the variety of evidence for interaction between desert and river over a range of spatial and temporal scales. This interaction presented both challenges and opportunities for its ancient inhabitants. This paper will present evidence for large-scale landscape changes driven by shifts in global climate. It will also show how we have integrated the archaeological and geological records in the Northern Dongola Reach and at Amara West - where long-term field projects led by archaeologists from the British Museum have recognised the importance of a sustained commitment to interdisciplinary research to achieve a fully integrated geoarchaeological approach across a range of scales. The former project is a large-scale landscape survey with multiple sites across an 80 km reach of the Nile whilst the latter has a strong focus on a single New Kingdom town site and changes in its environmental setting. By combining multiple archaeological and geological datasets - and pioneering the use of OSL dating and strontium isotope analysis in the Desert Nile - we have developed a new understanding of human responses to Holocene climate and landscape change in this region. Renfrew, C. (1976) Archaeology and the earth sciences. In: D.A. Davidson and M.I. Shackley (eds) Geoarchaeology: Earth Science and the Past, Duckworth, London, 1-5

    Cardiovascular autonomic dysfunction predicts increasing albumin excretion in type 1 diabetes.

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    OBJECTIVE: To determine the potential role of cardiovascular autonomic dysfunction in the development of renal complications in young people with type 1 diabetes (T1D). METHODS: In this prospective study, 199 children and adolescents recruited to the Oxford Regional Prospective Study underwent assessment of autonomic function ~5 years after diagnosis, and were subsequently followed with longitudinal assessments of HbA1c and urine albumin-creatinine ratio (ACR) over 8.6 ± 3.4 years. Autonomic function was assessed with 4 standardized tests of cardiovascular reflexes: heart rate (HR) response to (1) Valsalva Maneuver, (2) deep breathing, (3) standing, and (4) blood pressure (BP) response to standing. Linear mixed models were used to assess the association between autonomic parameters and future changes in ACR. RESULTS: Independent of HbA1c , each SD increase in HR response to Valsalva Maneuver predicted an ACR increase of 2.16% [95% CI: 0.08; 4.28] per year (P = .04), while each SD increase in diastolic BP response to standing predicted an ACR increase of 2.55% [95% CI: 0.37; 4.77] per year (P = .02). The effect of HR response to standing on ACR reached borderline significance (-2.07% [95% CI: -4.11; 0.01] per year per SD increase, P = .051). CONCLUSIONS: In this cohort of young people with T1D, enhanced cardiovascular reflexes at baseline predicted future increases in ACR. These results support a potential role for autonomic dysfunction in the pathogenesis of diabetic nephropathy

    Polymer of intrinsic microporosity (PIM-7) coating affects triphasic palladium electrocatalysis

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    A film of the polymer of intrinsic microporosity PIM-7 is coated onto a glassy carbon electrode and the resulting effects on electron transfer reactions are studied for three different types of processes: (i) aqueous solution based, (ii) solid state surface immobilised, and (iii) electrocatalytic processes on electrodeposited palladium. The effects on reactivity for hydroquinone oxidation in aqueous phosphate buffer are shown to be linked to microporosity causing a slightly lower rate of mass transport without detrimental effects on electron transfer and reaction kinetics. Next, water-insoluble microcrystalline anthraquinone is immobilised directly into the PIM-7 film and shown to give a chemically reversible reduction process, which is enhanced in the presence of PIM-7, when compared to the case of anthraquinone immobilised directly onto bare glassy carbon. Electrodeposition of a film of nano-palladium is demonstrated to give catalytically active electrodes for the reduction/oxidation of protons/hydrogen, the reduction of oxygen, and for the oxidation of formic acid and methanol. With the PIM-7 film applied onto palladium, a mechanical stabilisation effect occurs. In addition, both the hydrogen insertion and the hydrogen evolution reactions as well as formic acid oxidation are enhanced. Effects are discussed in terms of PIM-7 beneficially affecting the interfacial reaction under triphasic conditions. The microporous polymer acts as an interfacial “gas management” layer

    Polymer of Intrinsic Microporosity (PIM-7) Coating Affects Triphasic Palladium Electrocatalysis

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    A film of the polymer of intrinsic microporosity PIM-7 is coated onto a glassy carbon electrode and the resulting effects on electron transfer reactions are studied for three different types of processes: (i) aqueous solution based, (ii) solid state surface immobilised, and (iii) electrocatalytic processes on electrodeposited palladium. The effects on reactivity for hydroquinone oxidation in aqueous phosphate buffer are shown to be linked to microporosity causing a slightly lower rate of mass transport without detrimental effects on electron transfer and reaction kinetics. Next, water-insoluble microcrystalline anthraquinone is immobilised directly into the PIM-7 film and shown to give a chemically reversible reduction process, which is enhanced in the presence of PIM-7, when compared to the case of anthraquinone immobilised directly onto bare glassy carbon. Electrodeposition of a film of nano-palladium is demonstrated to give catalytically active electrodes for the reduction/oxidation of protons/hydrogen, the reduction of oxygen, and for the oxidation of formic acid and methanol. With the PIM-7 film applied onto palladium, a mechanical stabilisation effect occurs. In addition, both the hydrogen insertion and the hydrogen evolution reactions as well as formic acid oxidation are enhanced. Effects are discussed in terms of PIM-7 beneficially affecting the interfacial reaction under triphasic conditions. The microporous polymer acts as an interfacial “gas management” layer.</p

    Medication adherence during adjunct therapy with statins and ACE inhibitors in adolescents with type 1 diabetes

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    OBJECTIVE: Suboptimal adherence to insulin treatment is a main issue in adolescents with type 1 diabetes. However, to date, there are no available data on adherence to adjunct noninsulin medications in this population. Our aim was to assess adherence to ACE inhibitors and statins and explore potential determinants in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS:There were 443 adolescents with type 1 diabetes recruited into the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT) and exposed to treatment with two oral drugs—an ACE inhibitor and a statin—as well as combinations of both or placebo for 2–4 years. Adherence was assessed every 3 months with the Medication Event Monitoring System (MEMS) and pill count. RESULTS: Median adherence during the trial was 80.2% (interquartile range 63.6–91.8) based on MEMS and 85.7% (72.4–92.9) for pill count. Adherence based on MEMS and pill count dropped from 92.9% and 96.3%, respectively, at the first visit to 76.3% and 79.0% at the end of the trial. The percentage of study participants with adherence ≥75% declined from 84% to 53%. A good correlation was found between adherence based on MEMS and pill count (r = 0.82, P < 0.001). Factors associated with adherence were age, glycemic control, and country. CONCLUSIONS: We report an overall good adherence to ACE inhibitors and statins during a clinical trial, although there was a clear decline in adherence over time. Older age and suboptimal glycemic control at baseline predicted lower adherence during the trial, and, predictably, reduced adherence was more prevalent in subjects who subsequently dropped out

    Does compulsory voting increase support for leftist policy?

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    Citizens unequally participate in referendums, and this may systematically bias policy in favor of those who vote. Some view compulsory voting as an important tool to alleviate this problem, whereas others worry about its detrimental effects on the legitimacy and quality of democratic decision making. So far, however, we lack systematic knowledge about the causal effect of compulsory voting on public policy. We argue that sanctioned compulsory voting mobilizes citizens at the bottom of the income distribution and that this translates into an increase in support for leftist policies. We empirically explore the effects of a sanctioned compulsory voting law on direct-democratic decision making in Switzerland. We find that compulsory voting significantly increases electoral support for leftist policy positions in referendums by up to 20 percentage points. We discuss the implications of these results for our understanding of the policy consequences of electoral institutions

    Effect of serum sample storage temperature on metabolomic and proteomic biomarkers

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    Prospective biomarker studies can be used to identify biomarkers predictive of disease onset. However, if serum biomarkers are measured years after their collection, the storage conditions might affect analyte concentrations. Few data exists concerning which metabolites and proteins are affected by storage at - 20 degrees C vs - 80 degrees C. Our objectives were to document analytes affected by storage of serum samples at - 20 degrees C vs - 80 degrees C, and to identify those indicative of the storage temperature. We utilized liquid chromatography tandem mass spectrometry and Luminex to quantify 300 analytes from serum samples of 16 Finnish individuals with type 1 diabetes, with split-aliquot samples stored at - 80 degrees C and - 20 degrees C for a median of 4.2 years. Results were validated in 315 Finnish and 916 Scottish individuals with type 1 diabetes, stored at -20 degrees C and at - 80 degrees C, respectively. After quality control, we analysed 193 metabolites and proteins of which 120 were apparently unaffected and 15 clearly susceptible to storage at - 20 degrees C vs - 80 degrees C. Further, we identified serum glutamate/glutamine ratio greater than 0.20 as a biomarker of storage at - 20 degrees C vs - 80 degrees C. The results provide a catalogue of analytes unaffected and affected by storage at - 20 degrees C vs - 80 degrees C and biomarkers indicative of suboptimal storage.Peer reviewe

    Comparison of hypertension healthcare outcomes among older people in the USA and England

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    Funding: Economic and Social Research Council. G1001375/1. Medical Research Council. G1001375/1. US Department of Health and Human Services. National Institutes of Health. National Institute on Aging. 2R01 AG030153.Background The US and England have very different health systems. Comparing hypertension care outcomes in each country enables an evaluation of the effectiveness of each system. Method The English Longitudinal Study of Ageing and the Health and Retirement Survey are used to compare the prevalence of controlled, uncontrolled and undiagnosed hypertension in the population aged over 50 in the US and in England. Results Controlled hypertension is more prevalent in the US (age 50 to 64: 0.53 (0.50-0.57) and age 65+: 0.51 (0.49-0.53)) than in England (age 50 to 64: 0.45 (0.42-0.48) and age 65+: 0.42 (0.40-0.45)). This difference is driven by lower undiagnosed hypertension in the US (age 50 to 64: 0.18 (0.15-0.21) and age 65+: 0.13 (0.12-0.14)) relative to England (age 50 to 64: 0.26 (0.24-0.29) and age 65+: 0.22 (0.20-0.24)). The prevalence of uncontrolled hypertension is very similar in the US (age 50 to 64: 0.29 (0.26-0.32) and age 65+: 0.36 (0.34-0.38)) and England (age 50 to 64: 0.29 (0.26-0.32) and age 65+: 0.36 (0.34-0.39)). Hypertension care outcomes are comparable across US insurance categories. In both countries undiagnosed hypertension is positively correlated with wealth (ages 50-64). Uncontrolled hypertension declines with rising wealth in the US. Conclusions Different diagnostic practices are likely to drive the cross-country differences in undiagnosed hypertension. US government health systems perform at least as well as private health care and are more equitable in the distribution of care outcomes. Higher undiagnosed hypertension among the affluent may reflect less frequent medical contact.Publisher PDFPeer reviewe

    The urinary cytokine/chemokine signature of renal hyperfiltration in adolescents with type 1 diabetes.

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    OBJECTIVE: Urinary cytokine/chemokine levels are elevated in adults with type 1 diabetes (T1D) exhibiting renal hyperfiltration. Whether this observation extends to adolescents with T1D remains unknown. Our first objective was to determine the relationship between hyperfiltration and urinary cytokines/chemokines in normotensive, normoalbuminuric adolescents with T1D using GFR(cystatin). Our second aim was to determine the relationship between urine and plasma levels of inflammatory biomarkers, to clarify the origin of these factors. METHODS: Urine and serum cytokines/chemokines (Luminex platform) and GFR(cystatin) were measured in normofiltering (n = 111, T1D-N, GFR<135 ml/min/1.73 m(2)) and hyperfiltering (n = 31, T1D-H, GFR ≥ 135 ml/min/1.73 m(2)) adolescents with T1D (ages 10-16), and in age and sex matched healthy control subjects (HC, n = 59). RESULTS: We noted significant step-wise increases in urinary cytokine/chemokine excretion according to filtration status with highest levels in T1D-H, with parallel trends in serum analyte concentrations. After adjusting for serum glucose at the time of sampling, differences in urinary cytokine excretion were not statistically significant. Only serum IL-2 significantly differed between HC and T1D (p = 0.0076). CONCLUSIONS: Hyperfiltration is associated with increased urinary cytokine/chemokine excretion in T1D adolescents, and parallel trends in serum cytokine concentration. The GFR-associated trends in cytokine excretion may be driven by the effects of ambient hyperglycemia. The relationship between hyperfiltration, glycemia, and variations in serum and urine cytokine expression and their impact on future renal and systemic vascular complications requires further study
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