2,235 research outputs found

    QCD Flux Tubes as Sigma Model Relics

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    We describe flux tubes and their interactions in a low energy sigma model induced by SU(\NF) \goto SO(\NF) flavor symmetry breaking in SO(Nc)SO(N_c) QCD. Gauge confinement manifests itself in the low energy theory through flux tube interactions with unscreened sources. The flux tubes which mediate confinement also illustrate an interesting ambiguity in defining global Alice strings.Comment: 12 pages (REVTEX) plus one figur

    Natural Transport of Volatile Organic Compounds Due to Annual Variation of Soil Temperature

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    A theoretical investigation of factors affecting gas phase transport of volatile organic compounds in unsaturated zone is presented. Studying annual soil temperature variation with time and depth declares that there is a considerable temperature variation in the upper few meters that may affect the overall natural mass transport of volatile organic compounds. A one-dimensional mathematical model is used to study the effect of soil temperature variation on diffusive mass transport. From the analytical solution, it is clear that there is a significant net mass transport upward direction and a stimulated spatial oscillation of contaminant concentration in soil. The magnitude of these two modes of mass transport is higher as the contaminant is more volatile

    Predicting NOM Removal by Fixed-Bed GAC Adsorbers

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    Natural Organic Matter (NOM) normally exists in raw surface water as a complex mixture of organic compounds, mainly humic acids and fulvic acids. In water treatment plants, free chlorine reacts with NOM and forms a wide range of substances known as Disinfection Byproducts (DBPs). Granular Activated Carbon (GAC) adsorption is one of the best available technologies employed for the removal of NOM. A mathematical model for the adsorption of NOM onto GAC in a fixed bed column and in a batch reactor was built. The mathematical model was solved numerically using finite element and orthogonal collocation methods. Experiments were conducted using Rapid Small Scale Column Test (RSSCT) to evaluate the performance of GAC column to remove or reduce the concentration of NOM in raw water. The predicted values from the mathematical model showed very good agreement with the experimental measurements for a range of empty bed contact time, GAC particle size and raw water pH. Most of the mathematical model parameters were determined experimentally in adsorption equilibrium isotherm and batch reactor experiments

    Carga, acceso y disparidades en enfermedad renal

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    Kidney disease is a global public health problem that affects more than 750 million persons worldwide.1 The burden of kidney disease varies substantially across the world, as does its detection and treatment. Although the magnitude and impact of kidney disease is better defined in developed countries, emerging evidence suggests that developing countries have a similar or even greater kidney disease burden. In many settings, rates of kidney disease and the provision of its care are defined by socioeconomic, cultural, and political factors, leading to significant disparities in disease burden, even in developed countries.3 These disparities exist across the spectrum of kidney disease—from preventive efforts to curb development of acute kidney injury (AKI) or chronic kidney disease (CKD), to screening for kidney disease among persons at high risk, to access to subspecialty care and treatment of kidney failure with renal replacement therapy (RRT). World Kidney Day 2019 offers an opportunity to raise awareness of kidney disease and highlight disparities in its burden and current state of global capacity for prevention and management. In this editorial, we highlight these disparities and emphasize the role of public policies and organizational structures in addressing them. We outline opportunities to improve our understanding of disparities in kidney disease, the best ways for them to be addressed, and how to streamline efforts toward achieving kidney health equity across the globe.La enfermedad renal es un problema global de salud pública que afecta a más de 750 millones de personas alrededor de todo el mundo1. La carga de la enfermedad renal varía sustancialmente a lo largo del planeta, al igual que su detección y tratamiento. A pesar de que la magnitud y el impacto de la enfermedad renal está mejor definida en los países desarrollados, evidencia reciente sugiere que los países en desarrollo tienen una carga de la enfermedad similar o incluso mayor que los primeros2.En muchos escenarios, las tasas de enfermedad renal y la provisión de su cuidado están definidas por factores socioeconómicos, culturales y políticos, ocasionando disparidades significativas en la carga de la enfermedad, aún en países desarrollados3. Estas disparidades existen a lo largo de todo el espectro de la enfermedad renal – desde los esfuerzos preventivos para limitar el desarrollo de la lesión renal aguda (LRA) o de la enfermedad renal crónica (ERC), al tamizaje para enfermedad renal entre las personas con alto riesgo de desarrollarla, al acceso a cuidado y tratamiento subespecializado de la falla renal con terapia de reemplazo renal (TRR). El Día Mundial del Riñón 2019 ofrece una oportunidad para hacer conciencia de la enfermedad renal y resaltar las disparidades en su carga y el estado actual de la capacidad global para su prevención y manejo. En esta editorial, resaltamos estas disparidades y hacemos énfasis en el rol de las políticas públicas y las estructuras organizacionales en su atención. También destacamos las oportunidades de mejorar nuestro entendimiento de las disparidades en la enfermedad renal, la major formas de que éstas puedan ser reducidas, y como canalizar esfuerzos enfocados a alcanzar una salud renal con equidad a lo largo del planeta

    Cohen strongly p-summing holomorphic mappings on Banach spaces

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    Let EE and FF be complex Banach spaces, UU be an open subset of EE and 1≤p≤∞1\leq p\leq\infty. We introduce and study the notion of a Cohen strongly pp-summing holomorphic mapping from UU to FF, a holomorphic version of a strongly pp-summing linear operator. For such mappings, we establish both Pietsch domination/factorization theorems and analyse their linearizations from G∞(U)\mathcal{G}^\infty(U) (the canonical predual of H∞(U)\mathcal{H}^\infty(U)) and their transpositions on H∞(U)\mathcal{H}^\infty(U). Concerning the space DpH∞(U,F)\mathcal{D}_p^{\mathcal{H}^\infty}(U,F) formed by such mappings and endowed with a natural norm dpH∞d_p^{\mathcal{H}^\infty}, we show that it is a regular Banach ideal of bounded holomorphic mappings generated by composition with the ideal of strongly pp-summing linear operators. Moreover, we identify the space (DpH∞(U,F∗),dpH∞)(\mathcal{D}_p^{\mathcal{H}^\infty}(U,F^*),d_p^{\mathcal{H}^\infty}) with the dual of the completion of tensor product space G∞(U)⊗F\mathcal{G}^\infty(U)\otimes F endowed with the Chevet--Saphar norm gpg_p

    Traumatismes du rachis dorsolombaire : étude rétrospective sur les traumatismes du rachis dorsolombaire A propos de 26 cas

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    Notre travail est une étude rétrospective des caractéristiques épidémiologiques, diagnostiques et thérapeutiques des traumatismes du rachis dorsolombaire dans le service de traumatologie du CHU Frantz Fanon, sur une période de 2 ans, allant du Janvier 2015 au Décembre 2016. ON a souligné les données suivantes : L’âge moyen de nos malades est de 29 ans. Le sexe masculin est le plus atteint (80,76%). Les étiologies sont dominées par les AVP avec un pourcentage de 53.84%, suivies des CHUTES (46,15%). La douleur rachidienne de la région traumatisée est le signe révélateur principal. Les déficits neurologiques sont fréquents (96,26%). Les fractures de la charnière dorsolombaire prédominent sur les atteintes lombaires et dorsales. La fracture- tassement est la lésion prédominante (65,35%) avec siège électif au niveau de la 1ère vertèbre lombaire. Le traitement chirurgical assurant une fixation efficace des lésions instables, a été réalisé chez tous les patients. L’évolution des paraplégiques reste encore menacée par certaines complications de la période initiale notamment les infections urinaires. L’évolution des troubles neurologiques étant dans l’ensemble variable. La lésion médullaire complète a un pronostic péjoratif.Notre travail est une étude rétrospective des caractéristiques épidémiologiques, diagnostiques et thérapeutiques des traumatismes du rachis dorsolombaire dans le service de traumatologie du CHU Frantz Fanon, sur une période de 2 ans, allant du Janvier 2015 au Décembre 2016. ON a souligné les données suivantes : L’âge moyen de nos malades est de 29 ans. Le sexe masculin est le plus atteint (80,76%). Les étiologies sont dominées par les AVP avec un pourcentage de 53.84%, suivies des CHUTES (46,15%). La douleur rachidienne de la région traumatisée est le signe révélateur principal. Les déficits neurologiques sont fréquents (96,26%). Les fractures de la charnière dorsolombaire prédominent sur les atteintes lombaires et dorsales. La fracture- tassement est la lésion prédominante (65,35%) avec siège électif au niveau de la 1ère vertèbre lombaire. Le traitement chirurgical assurant une fixation efficace des lésions instables, a été réalisé chez tous les patients. L’évolution des paraplégiques reste encore menacée par certaines complications de la période initiale notamment les infections urinaires. L’évolution des troubles neurologiques étant dans l’ensemble variable. La lésion médullaire complète a un pronostic péjoratif

    Impact of irrigation management on crop water footprint reduction using RZWQM2 in Baghdad, Iraq

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    Water scarcity becomes a serious global challenge in several world regions and particularly in the Middle East. Appropriate irrigation practice is critical for improving crop yield and alleviating crop water footprint (WF). To alleviate water scarcity, the possibility of reducing wheat and barley water footprint has been examined through alternative surface irrigation practices. The WF was compared under farmers’ irrigation practice and experimental irrigation practice to discover the impact of irrigation practices on the reduction of WF in the west of Baghdad. Weather data and crop management information were collected from 2016 to 2020 for the farmer’s fields in the study area as well as for the experimental field. The Root Zone Water Quality Model (RZWQM2) was used for estimating wheat and barley evapotranspiration. The study results showed that the crop WF was well estimated using the RZWQM2 due to the model capability and accuracy for estimating the impact of field management on crop evapotranspiration and crop water use. Experimental irrigation practice could improve crop yield, water use efficiency, and water profitability by up to 28%, 35%, and 35%, respectively; while the WF was reduced by 35%, compared to the farmers’ irrigation practice. The WF of the wheat crop was lower than the barley WF due to the low barley production

    Reuse of Iraqi Agricultural Drainage Water Using Nanofiltration

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    Abstract: Irrigated areas between Euphrates and Tigris rivers in Iraq suffer from salinity buildup in the root zone of corps. Agricultural drain water (ADW) from these areas is collected in a single main drain canal, in an annual flow rate of about 6 billion cubic meter. In the present work, a pilot-scale nanofiltration membranes unit was used to evaluate the feasibility of desalinating ADW from the main drain canal for further reuse. Bench scale experiments were conducted to determine the optimum anti-scale dosage values in the unit. These values were verified in a plate type laboratory scale NF membrane to visually monitor the onset of crystal appearance behavior. A method for calcium sulfate precipitation control is presented and an empirical correlation of anti-scale dosage as a function of concentration factor (CF) was obtained. A pilot-scale unit was used to investigate the performance of NF membrane. High rejection values for both cations and anions indicate that the use of NF membrane in desalinating ADW from the Iraqi main drain canal is promising. The treated drainage water is considered good for irrigation when classified according to Wilcox classification

    Setting international standards for patient and parent involvement and engagement in childhood, adolescent and young adult cancer research: A report from a European Collaborative Workshop

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    BACKGROUND: Patient and Public Involvement and Engagement (PPIE) in research, advocates for research conducted ‘with’ not ‘for’ the affected population. In paediatric oncology research, the parents of children, adolescents and young adults affected by cancer are represented by the term ‘public’ in the acronym PPIE. Patients (those with cancer and cancer survivors) are also passionate advocates who drive forward the research priorities of children, adolescents and young adults throughout the entire research process. AIMS: A workshop was held at an international professional meeting in 2019 with the aim to define Patient and Parent Involvement and Engagement (PPIE); capture PPIE activities on a European level; and to explore the role of PPIE in non-interventional research. A proposed framework for a European PPIE strategy for childhood, adolescent and young adult cancers was also discussed. METHODS: The 60-minute workshop was attended by health care professionals, researchers, scientists, parents, survivors and charity/support organisations. A presentation to define PPIE, including the difference in terminology for PPIE in the context of childhood, adolescent, and young adult cancers was discussed. Best practice examples from the United Kingdom (UK) helped to demonstrate the positive impact of PPIE in paediatric oncology research. Three breakout groups then explored themes relating to PPIE, namely PPIE priorities, PPIE mapping for Europe, and PPIE in non-interventional research and data-linkage. RESULTS: Disparity in PPIE activities across Europe was evident, with ambiguity surrounding terminology and expected roles for PPIE representatives in paediatric oncology research. A lack of PPIE activity in Eastern Europe correlated with a lack of availability for clinical trials and poorer survival rates for paediatric oncology patients. There was unanimous support for PPIE embedded research in all areas, including in non-interventional studies. CONCLUSION: A European-level definition of PPIE for paediatric oncology research is needed. Further exploration into the role and responsibilities of patients, parents, and professionals when undertaking PPIE related activities is also recommended. Best practice examples from the UK, France, Germany, The Netherlands and Belgium demonstrated a preliminary evidence base from which a European PPIE strategy framework can be designed, inclusive of the patient and parent voice
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