804 research outputs found

    Heavy-ion physics studies for the Future Circular Collider

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    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode including proton and nucleus beams, more than seven-times larger than the nominal LHC energies. An electron-positron collider in the same tunnel is also considered as an intermediate step, which would provide the electron-hadron option in the long term. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of Quark-Gluon Plasma, gluon saturation, photon-induced collisions, as well as connections with ultra-high-energy cosmic rays.Comment: 4 pages, 3 figures, proceedings of Quark Matter 2014, Darmstadt, Germany, submitted to Nucl. Phys.

    Nuclear collisions at the Future Circular Collider

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    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.Comment: 4 pages, 5 figures, proceedings of Quark Matter 201

    Particle filters for high‐dimensional geoscience applications: a review

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    Particle filters contain the promise of fully nonlinear data assimilation. They have been applied in numerous science areas, including the geosciences, but their application to high-dimensional geoscience systems has been limited due to their inefficiency in high-dimensional systems in standard settings. However, huge progress has been made, and this limitation is disappearing fast due to recent developments in proposal densities, the use of ideas from (optimal) transportation, the use of localization and intelligent adaptive resampling strategies. Furthermore, powerful hybrids between particle filters and ensemble Kalman filters and variational methods have been developed. We present a state-of-the-art discussion of present efforts of developing particle filters for high-dimensional nonlinear geoscience state-estimation problems, with an emphasis on atmospheric and oceanic applications, including many new ideas, derivations and unifications, highlighting hidden connections, including pseudo-code, and generating a valuable tool and guide for the community. Initial experiments show that particle filters can be competitive with present-day methods for numerical weather prediction, suggesting that they will become mainstream soon

    Mid- and late-Holocene vegetation and fire history at Biviere di Gela, a coastal lake in southern Sicily, Italy

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    The vegetation and fire history of few coastal sites has been investigated in the Mediterranean region so far. We present the first paleoecological reconstruction from coastal Sicily, the largest island in the Mediterranean Sea. We analysed pollen and charcoal in the sediments of Biviere di Gela, a lake (lagoon) on the south coast of Sicily. Our data suggest that the area became afforested after a marine transgression at ca. 7200 cal b.p. (5250 b.c.). Build-up of forest and shrublands took ca. 200-300years, mainly with the deciduous trees Quercus, Ostrya and Fraxinus. Juniperus expanded ca. 6900 cal b.p. (4950 b.c.), but declined again 6600 cal b.p. (4650 b.c.). Afterwards, evergreen trees (Q. ilex-type and Olea) became dominant in the forest and Pistacia shrublands were established. Forest and shrubland reached a maximum ca. 7000-5000 cal b.p. (5050-3050 b.c.); subsequently forest declined in response to human impact, which was probably exacerbated by a general trend towards a more arid climate. During the Neolithic, fire was used to open the landscape, significantly reducing several arboreal taxa (Q. ilex, Fraxinus, Juniperus) and promoting herbs and shrubs (Achillea, Cichorioideae, Brassicaceae, Ephedra). Final forest disruption occurred around 2600 cal b.p. (650 b.c.) with the onset of the historically documented Greek colonization. We conclude that the open maquis and garrigue vegetation of today is primarily the consequence of intensive land-use over millennia. Under natural or near-natural conditions arboreal taxa such as Q. ilex, Olea and Pistacia would be far more important than they are today, even under the hot and rather dry coastal conditions of southern Sicil

    Multispecies fish tracking across newly created shallow and deep habitats in a forward-restored lake

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    Background: Freshwater fish communities typically thrive in heterogenous ecosystems that offer various abiotic conditions. However, human impact increasingly leads to loss of this natural heterogeneity and its associated rich fish communities. To reverse this trend, we need guidelines on how to effectively restore or recreate habitats for multiple fish species. Lake Markermeer in the Netherlands is a human-created 70,000-ha lake with a uniform 4 m-water depth, steep shorelines, high wind-induced turbidity, and a declining fish community. In 2016, a forward-looking restoration project newly created a 1000-ha five-island archipelago in this degrading lake, which offered new sheltered shallow waters and deep sand excavations to the fish community. Methods: In 2020, we assessed how omnivorous and piscivorous fish species used these new habitats by tracking 78 adult fish of five key species across local and lake-scales. We monitored spring arrival of adult fish and assessed local macro-invertebrate and young-of-the-year fish densities. Results: Adult omnivorous Cyprinidae and piscivorous Percidae arrived at the archipelago in early spring, corresponding with expected spawning movements. During the productive summer season, 12 species of young-of-the-year fish appeared along the sheltered shorelines, with particularly high densities of common roach (Rutilus rutilus) and European perch (Perca fluviatilis). This suggests the sheltered, shallow, vegetated waters formed new suitable spawning and recruitment habitat for the fish community. Despite highest food densities for adult fish in the shallowest habitats (&lt; 2-m), adult fish preferred minimally 2-m deep water. After spawning most Cyprinidae left the archipelago and moved long distances through the lake system, while most Percidae remained resident. This may be related to (1) high densities of young-of-the-year fish as food for piscivores, (2) medium food densities for omnivores compared to elsewhere in the lake-system, or (3) the attractiveness of 30-m deep sand excavations that were newly created and frequently used by one-third of all tracked fish. Conclusions: New littoral zones and a deep sand excavation constructed in a uniform shallow lake that lacked these habitat types attracted omnivorous and piscivorous fish species within four years. Both feeding guilds used the littoral zones for reproduction and nursery, and notably piscivorous fish became residents year-round.</p

    Mercadeo

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    Se describen conceptos asociados al mercadeo y se presenta el material de referencia que corresponde al área de mercadeo de la empresa asociativa en todas sus facetas y durante todas sus fases de desarrollo.Concepts associated with marketing are described and the reference material corresponding to the marketing area of the associative company in all its facets and during all its development phases is presented.El concepto de mercadeo -- Definición del mercado para la empresa asociativa -- Estrategia del mercado para la empresa asociativa -- El producto -- El precio -- La distribución -- La promociónnaDocumento producto del convenio de cooperación técnica SENA - Holanda.Series de la colección PMUR: 1. Guía Metodológica; 2. Material Didáctico; 3. Lecturas de Referencia; 4. Estudios.Publicaciones de la serie “Lecturas de referencia” : 1. Características de las Empresas Asociativas; 2. Mercadeo; 3. Producción; 4. Tecnología; 5. Financiación; 6. Contabilidad; 7. Marco Legal; 8. Formación Socioempresarial.92 página

    Producción

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    Fascículo que describe el concepto de producción, se exponen las características y objetivos específicos de la producción en la pequeña empresa asociativa, sistemas para preparación, programación y organización de la producción y métodos para el cálculo de costos de producción.Fascicle describing the concept of production, the specific characteristics and objectives of production in the small associative enterprise, systems for preparation, programming and organization of production and methods for calculating production costs are set out.Características y objetivos de la pequeña empresa -- Preparación, programación y organización de la producción en empresas urbanas -- Preparacion programacion y organizacion de la producción en empresas agropecuarias -- Calculo de costos de producción en empresas urbanas -- Cálculo de costos de producción en empresas ruralesna75 página

    Financiación

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    Fascículo de la serie “Lecturas de referencia” que describe cómo tratar los problemas financieros en las empresas asociativas, sistema financiero adecuado en la empresa asociativa y principios para el manejo del área financiera.Fascicle of the series “Reference readings” that describes how to deal with financial problems in associative companies, adequate financial system in the associative company and principles for managing the financial area.La problemática de la financiación de empresas asociativas en los niveles informales -- una visión estructural del problema -- sistema financiero adecuado - el fondo de apoyo de empresas asociativas -- el manejo del área financiera al interior de las empresasnaDocumento producto del convenio de cooperación técnica SENA - Holanda.Series de la colección PMUR: 1. Guía Metodológica; 2. Material Didáctico; 3. Lecturas de Referencia; 4. Estudios.Publicaciones de la serie “Lecturas de referencia” : 1. Características de las Empresas Asociativas; 2. Mercadeo; 3. Producción; 4. Tecnología; 5. Financiación; 6. Contabilidad; 7. Marco Legal; 8. Formación Socioempresarial.40 página

    Formas cuspidales de playas y procesos de la zona de rompientes interna: ¿crecimiento o destrucción? Aplicación a la playa de Trafalgar (Cádiz, España)

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    Large beach cusps (LBC, wavelength of ~ 30 m) are intertidal features that can alternately exist in the swash and in the inner surf zone due to tidal sea level changes. They have a larger cross-shore extent (up to 50 m) than traditional cusps. This extent has been explained by a shift of the swash zone during falling tide. The cusps immerse at rising tide and previous studies indicate that surf zone processes are exclusively destructive. Here, the behaviour of large beach cusps in the inner surf zone is investigated by using a 2DH morphological numerical model applied to Trafalgar Beach (Cádiz, Spain). The model results indicate that the inner surf zone processes do not always destroy the cusps but can in fact reinforce them by considering neither the swash processes nor the tidal changes. More generally, in conditions favouring the presence of the LBC the surf zone of a beach can be unstable, leading to the formation of transverse/oblique sand bars that can have characteristics similar to the LBC. Thus, in principle, the LBC could emerge not only due to swash zone morphodynamics but also due to surf zone morphodynamics or a combination of both.Las formas cuspidales de grandes dimensiones (LBC, longitudes de onda ~30 m) constituyen un sistema morfológico rítmico a lo largo de la playa que tiene una parte que se encuentra alternativamente en la zona de swash (flujo/reflujo) y en la zona de rompientes interna debido a los cambios del nivel del mar. Tienen una distancia de penetración de hasta 50 m, superior por tanto a la de las cúspides ordinarias. Esta elongación parece debido a la traslación de la zona de swash durante la marea descendente. En marea ascendente estas estructuras están sumergidas y los estudios previos consideran que los procesos de la zona de rompientes las destruyen. En este trabajo se analiza el comportamiento de estas formas en la zona de rompientes de la playa de Trafalgar (Cádiz) usando un modelo numérico morfológico 2DH. Los resultados muestran que, sin considerar ni los procesos de swash ni el cambio de marea, los procesos de la zona de rompientes no necesariamente destruyen LBC, sino que pueden reforzarlas. De forma más general, en condiciones favorables a la presencia de LBC, se pueden formar barras de arena con características similares a LBC debido a procesos de auto-organización en la zona de rompientes.The work of R. Garnier was supported by the University of Nottingham and is part of the Spanish Government project under contract CTM2006-08875. The Spanish Ministry of Science and Education (Project BORRASCAS CTM2005-06583) and the Junta de Andalucía (Projects P05-RNM-968 and P06-RNM-1573) funded part of this research

    Beliefs, barriers and preferences of European overweight women to adopt a healthier lifestyle in pregnancy to minimize risk of developing gestational diabetes mellitus: an explorative study

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    Introduction: Overweight and obese women are at high risk of developing gestational diabetes mellitus (GDM). Lifestyle programs might help curb the GDM risk. We explored beliefs, perceived barriers and preferences regarding lifestyle changes among overweight European pregnant women to help inform the development of future high quality lifestyle interventions. Methods: An explorative mixed methods, two-staged study was conducted to gather information from pregnant European women (BMI≥25kg/m2). In three European countries (Belgium, Netherlands, United Kingdom) interviews were conducted, followed by questionnaires in six other European countries (Austria, Denmark, Ireland, Italy, Poland, Spain). Content analysis, descriptive and chi square statistics were applied (p&#60;0.05). Results: Women preferred to obtain detailed information about their personal risk. The health of their baby was major motivating factor. Perceived barriers for physical activity included pregnancy-specific issues such as tiredness and experiencing physical complaints. Insufficient time was a barrier more frequently reported by women with children. Abstaining from snacking was identified as a challenge for the majority of women, especially for those without children. Women preferred to obtain support from their partner, as well as health professionals and valued flexible lifestyle programs. Conclusions: Healthcare professionals need to inform overweight pregnant women about their personal risk, discuss lifestyle modification and assist in weight management. Lifestyle programs should be tailored to the individual, taking into account barriers experienced by overweight first-time mothers and multipara women
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