744 research outputs found
The Bulk RS KK-gluon at the LHC
We study the possibility of discovering and measuring the properties of the
lightest Kaluza-Klein excitation of the gluon in a Randall-Sundrum scenario
where the Standard Model matter and gauge fields propagate in the bulk. The
KK-gluon decays primarily into top quarks. We discuss how to use the final states to discover and probe the properties of the KK-gluon.
Identification of highly energetic tops is crucial for this analysis. We show
that conventional identification methods relying on well separated decay
products will not work for heavy resonances but suggest alternative methods for
top identification for energetic tops. We find, conservatively, that resonances
with masses less than 5 TeV can be discovered if the algorithm to identify high
tops can reject the QCD background by a factor of 10. We also find that
for similar or lighter masses the spin can be determined and for lighter masses
the chirality of the coupling to can be measured. Since the energetic
top pair final state is a generic signature for a large class of new physics as
the top quark presumably couples most strongly to the electroweak symmetry
breaking sector, the methods we have outlined to study the properties of the
KK-gluon should also be important in other scenarios.Comment: 21 pages, 13 figure
Assessing spatial and temporal distributions of marine litter: 11-year dataset of coastal floating marine debris in the Balearic Islands
The present work constitutes a preliminary assessment of the spatial and temporal distribution of floating marine debris along the Balearic Islands’ coastline during the months of May - October from 2005 to 2015. This long-term dataset indicates marine debris was found in 42.46% of all monitoring surveys, with plastic marine debris being found in 93.41% of the marine debris surveyed. Elevated accumulation zones were present in the southern regions and plastic was consistently the most abundant for both nearshore and offshore coastal areas. This study provides insight into the magnitude of marine debris surrounding the Balearic Islands highlighting the need for action and awareness to address its increasing pressures on marine and coastal ecosystems
A software system to teach economics to secondary school and first year engineering students
[EN] In this paper, we present a graphical user interface which has been devised to teach the basic concepts of economics in secondary schools and first year engineering courses. The application allows students to vary certain parameters and visually observe the effect on the supply and demand curves. The system has been developed in Matlab and employed in a secondary school in Spain. The first results are presented.[ES] Presentamos una interfaz gráfica desarrollada mediante Matlab diseñada para complementar el aprendizaje de los conceptos básicos de economía en Bachillerato, grado superior de ciclos formativos y cursos universitarios de introducción a la economía. La aplicación informática permite que los estudiantes varíen los parámetros de los que dependen las curvas de oferta y demanda, y visualicen el efecto sobre el equilibrio de mercado de estas variaciones. Se presentan los resultados de una primera experiencia de aplicación del programa en enseñanza secundaria en España.García-March, M.; Zacarés, M.; Isidro, J.; Monreal, L.; López-Javier, C.; Arevalillo-Herráez, M. (2009). A software system to teach economics to secondary school and first year engineering students. Modelling in Science Education and Learning. 2:105-113. doi:10.4995/msel.2009.3126SWORD105113
Teaching classical mechanics using an applied example: Modelling and Software
[EN] We present our experience in using a common mechanism in engineering, such as a slider-crank, to explain classical mechanics in physics and engineering degrees. We also present a graphical user interface that permits the student to visualize the results of different simulations varying the conditions of the numerical experiment.[ES] Presentamos la experiencia docente obtenida al utilizar un mecanismo muy común en ingeniería, como el mecanismo biela-manivela-deslizadera, como un ejemplo práctico en la asignatura ”mecánica clásica” que se imparte en los grados de física e ingeniería. También presentamos una interfaz gráfica que permite al estudiante visualizar los resultados obtenidos al simular en el ordenador el movimiento de dicho mecanismo variando las condiciones en las que se realiza el experimento numérico.García-March, M.; Isidro, J.; Zacarés, M.; Arevalillo, M.; González-Santander, J.; Monreal, L.; López-Javier, C. (2009). Teaching classical mechanics using an applied example: Modelling and Software. Modelling in Science Education and Learning. 2:35-43. doi:10.4995/msel.2009.3116SWORD35432H.Goldstein, Mecánica Clásica. Ed. Reverté, Barcelona, (1987). C.Lanczos, The variational principles of mechanics. Dover, New York, (1986).M.A. García-March, I. Orquín, P. Fernández de Córdoba, A. Montero, J. Urchueguía, M.H. Giménez y J.A. Monsoriu, Formulación Lagrangiana del Sistema Biela-Manivela- Deslizadera. Anales de Ingeniería Mecánica. Revista de la Asociación Espa-ola de Ingeniería Mecánica. 2 1077-1086 (2004)
Understanding the pain experience in hip and knee osteoarthritis – an OARSI/OMERACT initiative
SummaryObjectiveTo examine the pain experience of people with hip or knee osteoarthritis (OA), particularly changes over time and most distressing features.MethodFocus groups in individuals aged 40+ years with painful hip or knee OA obtained detailed descriptions of OA pain from early to late disease. A modified Patient Generated Index (PGI) was used to assess the features of OA pain that participants found most distressing. Content analysis was performed to examine response patterns; descriptive statistics were used to summarize PGI responses.ResultsMean age of the 143 participants (52 hip OA; 91 knee OA) was 69.5 years (47–92 years); 60.8% were female and 93.7% Caucasian. Participants described two distinct types of pain – a dull, aching pain, which became more constant over time, punctuated increasingly with short episodes of a more intense, often unpredictable, emotionally draining pain. The latter, but not the former, resulted in significant avoidance of social and recreational activities. From PGI responses, distressing pain features were: the pain itself (particularly intense and unpredictable pain) and the pain's impact on mobility, mood and sleep.ConclusionsTwo distinct pain types were identified. Intermittent intense pain, particularly when unpredictable, had the greatest impact on quality of life
Ecological information and water mass properties in the Mediterranean recorded by stable isotope ratios in Pinna nobilis shells
Sclerochronologic and stable isotope records in Pinna nobilis shells potentially record ecological and oceanographic information. P. nobilis is a subtidal bivalve adapted to live in a variety of environments in the Mediterranean. We hypothesized that stable isotope ratios (δ18O and δ13C) and growth increment patterns from individuals living in different environments serve as ecological indicators. Using a new methodology for calcite sampling, we (1) identified annual growth features (nacre tongues) and (2) compared monthly resolved variations in δ18O and δ13C values and calcification temperatures recorded in animals located above and below the thermocline (16 and 30 m depth). The specimens from 16 m showed more negative δ18O values than the specimen from 30 m, likely reflecting differences in salinity. The specimens from 30 m recorded δ13C values less positive than the specimens from 16 m, which we interpreted as an ontogenetic effect observed in previous studies. Estimated calcification temperatures were offset relative to measured water temperature by ∼6.1°C (∼1.4‰). This finding is evident in earlier proxy studies of P. nobilis, although it was not discussed in those studies. Using the seasonal pattern of δ18O and δ13C values, we demonstrated that nacre tongues are deposited annually and that their formation is independent of temperature. Food availability rather than temperature may control nacre tongue formation. An alternative explanation for nacre tongue formation is gonad maturation during spring. Our findings support the idea that sclerochronology in P. nobilis can be used to reconstruct environmental, ecological, and climate archives of the Mediterranean
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