931 research outputs found

    Governing processes for reactive nitrogen compounds in the atmosphere in relation to ecosystem climatic and human health impacts

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    Reactive nitrogen (Nr) compounds have different fates in the atmosphere due to differences in governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account these differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3) before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3−). In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3− contribute significantly to background PM2.5 and PM10 (mass of aerosols with a diameter of less than 2.5 and 10 μm, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant fraction of wet-deposited N, and is present in both gaseous and particulate forms in the atmosphere. Further studies are needed to characterize the sources, air chemistry and removal rates of organic N emissions

    Pavao Ritter Vitezovic : defining national identity in the baroque age

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    This thesis is intended as a contribution to the understanding of national identity construction by national elites in early modern Europe. It examines the development of national identity among the Croats and concentrates upon the life and work of the Croatian writer and scholar Pavao Ritter Vitezovic (1652-1713). His work in the fields of national history, linguistics and genealogy is treated as typical of the type of early modern scholar concerned with national identity, here termed identity constructor. The phenomenon of identity construction among the early modern Croats is set in the context of current debates over western and eastern models of national development. This is followed by an account of the development of a Croatian identity in the fields of politics and culture during the early modern period. Chapter Two is concerned with the social and intellectual forces which led early modern scholars to address questions of national identity. It examines Vitezovic's intellectual and moral world, in particular the character of his patriotism and its origins in humanist learning and in chivalry. Chapter Three looks at ideas of national renewal in Vitezovic's work. It discusses his analysis of the threats facing the Croats in terms of external enemies, namely the Turks and the lack of coherence among the Christian alliance, and internal enemies, namely the Croats' own decadence and indifference to their national identity. The next three chapters examine aspects of the identity which Vitezovic presented to the Croats in order to halt their decline into obsolescence. Chapter Four uses Vitezovic's ethnographic writings to examine how national identities are fashioned from existing material to suit current circumstances. It discusses his use of Slav and Illyrian literature to inspire the Croats with nostalgia for their former period of greatness. This longing would rouse the Croats from their present state of apathy and direct them towards the task of national self-renewal. Chapters Five and Six look at the importance of statehood for Croatian national identity. Chapter Five examines how Vitezovic set the existing political institutions of the Kingdom of Croatia within the context of the Croats' national history and defined the relations between the Croats and their king, the Habsburg Emperor. The following chapter looks at Vitezovic's grand scheme for an enlarged Kingdom of Croatia to be built under the aegis of the Emperor after the Ottoman withdrawal from the Balkans. It considers how historical and ethnic arguments are used to invest territory with national content. The concluding chapter examines problems of change and continuity within national identities. A brief survey of developments in Croatian national identity in the half century after Vitezovic's death and before the rise of the romantic movement is followed by a general conclusion on the constraints which determine how a nation creates its identity

    Search for Global Dipole Enhancements in the HiRes-I Monocular Data above 10^{18.5} eV

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    Several proposed source models for Ultra-High Energy Cosmic Rays (UHECRs) consist of dipole distributions oriented towards major astrophysical landmarks such as the galactic center, M87, or Centaurus A. We use a comparison between real data and simulated data to show that the HiRes-I monocular data for energies above 10^{18.5} eV is, in fact, consistent with an isotropic source model. We then explore methods to quantify our sensitivity to dipole source models oriented towards the Galactic Center, M87, and Centaurus A.Comment: 17 pages, 31 figure

    Active Brownian Particles. From Individual to Collective Stochastic Dynamics

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    We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

    Evaluation of Off-Farm Income-Generating Activities among Agroforestry Farmers in Sakponba Forest Reserve area, Edo State, Nigeria

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    The study evaluated off-farm generating activities among agro-forestry farmers in the Sakponba forest reserve area of Edo State, Nigeria. A multi-stage random sampling technique was used to collect data from one hundred and twenty (120) agroforestry farmers using a structured interview schedule. Percentages and frequency counts were used to analyse the objectives of the study. The result showed that majority 64.2% of the farmers were male. Further analysis indicated that 88.3% of the farmers engaged in cassava processing and 32.5% in okada business as off-farm income-generating activities. Further analysis revealed that 88.3% were involved in off-farm activities to generate additional income. However, 70.8% highlighted that high cost of transportation was a constraint, while, 59.2% indicated that inadequate diversification skills and training opportunities were the main constraints faced in engaging in off-farm income-generating activities. The study recommended that the government provide infrastructure such as a good road network, electricity, potable water, and affordable healthcare system, since they are important indicators for enhancing socio-economic activities in rural areas. It was also recommended that the government initiate policies for reducing risk and uncertainties inherent with agricultural activities such as access to credit to improve their standard of living and increase productivity

    Observation of the Ankle and Evidence for a High-Energy Break in the Cosmic Ray Spectrum

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    We have measured the cosmic ray spectrum at energies above 101710^{17} eV using the two air fluorescence detectors of the High Resolution Fly's Eye experiment operating in monocular mode. We describe the detector, PMT and atmospheric calibrations, and the analysis techniques for the two detectors. We fit the spectrum to models describing galactic and extragalactic sources. Our measured spectrum gives an observation of a feature known as the ``ankle'' near 3×10183\times 10^{18} eV, and strong evidence for a suppression near 6×10196\times 10^{19} eV.Comment: 14 pages, 9 figures. To appear in Physics Letters B. Accepted versio

    Outcome domains in lichen sclerosus

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    Lichen Sclerosus (LS) is a chronic inflammatory dermatosis predominantly affecting the genitals. It can affect men, women and children. LS affecting female genitalia typically presents with itchy patches that impact on physical and psychosocial‐sexual functioning1,2. Symptoms in men include difficulty urinating due to urethral narrowing, difficulty in foreskin retraction due to scarring, and dyspareunia. Complications include loss of anatomy and malignant transformation

    A somatic-mutational process recurrently duplicates germline susceptibility loci and tissue-specific super-enhancers in breast cancers

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    Somatic rearrangements contribute to the mutagenized landscape of cancer genomes. Here, we systematically interrogated rearrangements in 560 breast cancers by using a piecewise constant fitting approach. We identified 33 hotspots of large (>100 kb) tandem duplications, a mutational signature associated with homologous-recombination-repair deficiency. Notably, these tandem-duplication hotspots were enriched in breast cancer germline susceptibility loci (odds ratio (OR) = 4.28) and breast-specific 'super-enhancer' regulatory elements (OR = 3.54). These hotspots may b

    Report from the fifth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)

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    This is the report from the fifth meeting of the Harmonising Outcome Measures for Eczema initiative (HOME V). The meeting was held on 12–14 June 2017 in Nantes, France, with 81 participants. The main aims of the meeting were (i) to achieve consensus over the definition of the core domain of long-term control and how to measure it and (ii) to prioritize future areas of research for the measurement of the core domain of quality of life (QoL) in children. Moderated whole-group and small-group consensus discussions were informed by presentations of qualitative studies, systematic reviews and validation studies. Small-group allocations were performed a priori to ensure that each group included different stakeholders from a variety of geographical regions. Anonymous whole-group voting was carried out using handheld electronic voting pads according to predefined consensus rules. It was agreed by consensus that the long-term control domain should include signs, symptoms, quality of life and a patient global instrument. The group agreed that itch intensity should be measured when assessing long-term control of eczema in addition to the frequency of itch captured by the symptoms domain. There was no recommendation of an instrument for the core outcome domain of quality of life in children, but existing instruments were assessed for face validity and feasibility, and future work that will facilitate the recommendation of an instrument was agreed upon. The Harmonising Outcome Measures for Eczema (HOME) initiative is an international group working together to develop a core outcome set (COS) for clinical trials in eczema (synonymous with atopic eczema and atopic dermatitis). HOME is coordinated from the Centre of Evidence Based Dermatology, University of Nottingham, U.K. Participation in HOME is open to anyone with an interest in outcomes for eczema. A COS is the agreed upon minimum set of instruments that should be included in all clinical trials for a particular condition. Use of a COS does not preclude using other instruments; other domains and instruments can also be included to meet the specific requirements of individual trials. COS initiatives are active across many fields of medicine and should enable better synthesis of trial data and reduce selective outcome reporting bias. The HOME initiative follows the best current guidance on developing a COS. Four core domains have been identified: clinician-reported signs; patient-reported symptoms; quality of life; and long-term control. The core outcome measurement instruments for clinician-reported signs and patient-reported symptoms have been established: the Eczema Area and Severity Index (EASI) for measuring clinician reported signs was agreed on at the HOME III meeting, and the Patient-Oriented Eczema Measure (POEM) was chosen to measure patient-reported symptoms at the HOME IV meeting. This is a report from the fifth consensus meeting of the HOME initiative (HOME V), which was held on 12–14 June 2017 in Nantes, France. The local organizers were Sebastien Barbarot and Jean-Francois Stalder of Nantes University Hospital, France

    Cyclic voltammetry : a tool to quantify 2,4,6-trichloroanisole in aqueous samples from cork planks boiling industrial process

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    Chloroanisoles, namely 2,4,6-trichloroanisole, are pointed out as the primary responsible of the development of musty off-flavours in bottled wine, due to their migration from cork stoppers, which results in huge economical losses for wine industry. A prevention step is the detection of these compounds in cork planks before stoppers are produced. Mass spectrometry gas chromatography is the reference method used although it is far beyond economical possibilities of the majority of cork stoppers producers. In this work, a portable cyclic voltammetry approach was used to detect 2,4,6-trichloroanisole extracted from natural cork planks to the aqueous phase during the cork boiling industrial treatment process. Analyses were carried out under ambient conditions, in less than 15 min with a low use of solvent and without any sample pre-treatment. The proposed technique had detection (0.31±0.01 ng/L) and quantification (0.95±0.05 ng/L) limits lower than the human threshold detection level. For blank solutions, without 2,4,6-trichloroanisole addition, a concentration in the order of the quantification limit was estimated (1.0±0.2 ng/L), which confirms the satisfactory performance of the proposed methodology. For aqueous samples from the industrial cork planks boiling procedure, intra-day repeatabilities were lower than 3%, respectively. Also, 2,4,6-trichloroanisole contents in the aqueous samples determined by this novel approach were in good agreement with those obtained by GC-MS (correlation coefficient equal to 0.98), confirming the satisfactory accuracy of the proposed methodology. So, since this novel approach is a fast, low-cost, portable and user-friendly method, it can be an alternative and helpful tool for in-situ industrial applications, allowing accurate detection of releasable 2,4,6-trichloroanisole in an earlier phase of cork stoppers production, which may allow implementing more effective cork treatments to reduce or avoid future 2,4,6-trichloroanisole contaminations of wine.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia (Portugal)
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