64,564 research outputs found
Recent results from the cosmic ray program of the NA61/SHINE experiment
NA61/SHINE is a fixed target experiment designed to study hadron-proton,
hadron-nucleus and nucleus-nucleus interactions at the CERN
Super-Proton-Synchrotron. In this paper we summarize the results from
pion-carbon collisions recorded at beam momenta of 158 and 350 GeV/c. Hadron
production measurements in this type of interactions is of fundamental
importance for the understanding of the muon production in extensive air
showers. In particular, production of (anti)baryons and are mechanisms
responsible for increasing the number of muons which reaches the ground. The
underestimation of the (anti)baryons or production rates in current
hadronic interaction models could be one of the sources of the excess of muons
observed by cosmic ray experiments. The results on the production spectra of
, K, p, , , ,
K, , and K are presented, as well as
their comparison to predictions of hadronic interaction models currently used
in air shower simulations.Comment: 8 pages, 9 figures. To appear in the proceedings of the 20th
International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI
2018), Nagoya, Japa
Process and Progress: Reviewing the Criminal Justice Act
Prado describes the results of a comprehensive study of the federal defender program and concludes that as the federal criminal justice system evolves, the Criminal Justice Act program must adapt to ever-changing conditions
Tests of hadronic interactions with measurements by Pierre Auger Observatory
The hybrid design of the Pierre Auger Observatory allows for the measurement
of a number of properties of extensive air showers initiated by ultra-high
energy cosmic rays. By comparing these measurements to predictions from air
shower simulations, it is possible to both infer the cosmic ray's mass
composition and test hadronic interactions beyond the energies reached by
accelerators. In this paper, we will present a compilation of results of air
shower measurements by Pierre Auger Observatory which are sensitive to the
properties of hadronic interactions and can be used to constrain the hadronic
interaction models. The inconsistencies found between the interpretation of
different observables with regard to primary composition and between their
measurements and simulations show that none of the currently used hadronic
interaction models can provide a proper description of air showers and, in
particular, of the muon production.Comment: 6 pages, 5 figures. To appear in the proceedings of the 20th
International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI
2018), Nagoya, Japa
Measurements of Hadron Production in Pion-Carbon Interactions with NA61/SHINE at the CERN SPS
NA61/SHINE is a fixed target experiment designed to study hadron-proton,
hadron-nucleus and nucleus-nucleus interactions at the CERN
Super-Proton-Synchrotron. In this proceeding we present results on spectra of
identified hadrons produced in pion-carbon production interactions, which are
of fundamental importance to improve the extensive air shower modeling, and
hence the interpretation of ultra-high-energy-cosmic-rays measurements. In
particular, our measurements of (anti)baryons and production in
pion-carbon interactions can contribute to improve the predictions of muon
production by air shower simulations using hadronic interaction models. In this
contribution we discuss the data analysis and the results from pion-carbon
collisions recorded at beam momenta of 158 and 350 GeV/c. The preliminary
spectra of and () are shown, as well as a comparison to
predictions of hadronic interaction models used in air shower simulations.
Additionally, we present final results on the production of ,
and resonances.Comment: Proceedings of 35th International Cosmic Rays Conference, Busan,
South Kore
Potential climatic influence on the maximum stand carrying capacity of 15 Mediterranean conifers and broadleaves
Las proyecciones de cambio climático para la cuenca del Mediterráneo predicen un incremento continuo en episodios de sequía y calor extremos, afectando a la dinámica,
estructura y composición de las masas forestales. En este contexto, resulta fundamental
comprender cómo el clima influye en la relación tamaño-densidad máxima (recta de
autoclareo) de estas masas con el fin de diseñar actuaciones de gestión forestal
sostenible adaptadas a este nuevo escenario. Este estudio pretende avanzar en esta
línea, analizando los potenciales impactos del clima en el Índice de Máxima Densidad
(SDImax) de 15 especies forestales pertenecientes a los géneros Pinus, Fagus y Quercus.
Para ello se utilizaron las bases de datos del Tercer Inventario Forestal Nacional Español
(IFN3) y WorldClim. En primer lugar, se ajustaron rectas de autoclareo básicas mediante
regresión cuantílica y se estimaron nuevos valores SDImax de referencia por especie. En
un segundo paso, se seleccionaron 35 variables climáticas anuales y periódicas para
ajustar rectas de autoclareo dependientes del clima. El mejor modelo climáticodependiente
fue seleccionado para cada especie basándonos en el Indice de Información
de Akaike con el fin de analizar las tendencias generales y específicas en la variación de
SDImax. Para todas las especies de estudio, la influencia del clima sobre el SDImax fue
significativa. Los resultados obtenidos mostraron una tendencia común en la variación de
SDImax, con valores más pequeños vinculados a condiciones más secas y cálidas, lo que
sugiere reducciones potenciales del stock de estas especies bajo futuros escenarios
climáticos. En oposición a esta tendencia, el modelo de Pinus nigra sugiere que inviernos
más suaves como efecto de incrementos en temperaturas mínimas podrían beneficiar a
las especies en zonas de montaña. En general, el estrés hídrico (expresado a través del
Indice De Martonne) fue un factor determinante afectando al SDImax de Fagus, mientras
que cambios en las temperaturas de primavera y verano explicaron las variaciones SDImax
de las especies del género Quercus. Las especies de Pinus se vieron indistintamente
afectadas por potenciales variaciones de temperatura y humedad. Todos los modelos
climático-dependientes seleccionados mejoraron los modelos básicos y los modelos
ajustados en estudios similares, como aquellos que utilizan el Índice de Martonne como
variable climática independiente. Nuestros hallazgos destacan la necesidad de utilizar
variables climáticas periódicas para caracterizar mejor los impactos climáticos en el
SDImax. Los modelos presentados en este estudio permitirán obtener estimaciones más
precisas de la máxima densidad admisible por diferentes especies de coníferas y
frondosas, proporcionando una herramienta avanzada para la gestión forestal sostenible
de masas puras y mixtas mediterráneas bajo diferentes escenarios de cambio climático.Climate change projections for the Mediterranean basin predict a continuous increment in
extreme drought and heat episodes, affecting forest dynamics, structure and composition.
Understanding how climate influences the maximum size-density relationship (MSDR) is
therefore critical to design adaptative silvicultural guidelines based on the potential stand
carrying capacity of tree species. With this aim, data from the Third Spanish National
Forest Inventory (3NFI) and WorldClim databases were used to analyze climate related
variations of the maximum stand carrying capacity for 15 species from the Pinus, Fagus
and Quercus genus. First, basic MSDR were fitted using linear quantile regression and
observed size-density data from monospecific 3NFI plots. Reference values of maximum
stocking, expressed as SDImax, were estimated by species. In a second step, climatedependent
MSDR models including 35 different annual and seasonal climatic variables
were fitted. The best climate-dependent MSDR model was selected by species according
to the Akaike Information Criteria in order to analyze general and species-specific trends
in the SDImax variation. Results showed a common trend across species in SDIgenus
variation with smaller SDImax values linked to drier and warmer conditions, suggesting
potential reductions of the maximum stocking for this species based on projected climatic
scenarios. Opposed to this trend, results for Pinus nigra suggest that milder winters as
effect of increments in minimum temperatures could beneficiate mountainous species.
Humidity (expressed as the De Martonne Index) was found as key driver affecting SDImax
of Fagus species, since changes in spring and summer temperatures explained SDImax
variations of Quercus species. Pinus species were indistinctively affected by temperature
and water stress. All the selected climate-dependent models improved the goodness of fit
over the basic and the business-as-usual models including the De Martonne Index as
independent climatic variable. Our findings highlight the importance of using specific
climatic variables to better characterize climatic impacts on the MSDR. Models presented
in this study will allow to obtain more precise estimations of the maximum stocking for
different coniferous and broadleaved species, providing an advanced tool for managing
Mediterranean pure and mixed forests under different scenarios of climate change.Máster en Gestión Forestal basada en Ciencia de Dato
Homologous Recombination: To Fork and Beyond
Accurate completion of genome duplication is threatened by multiple factors that hamper the advance and stability of the replication forks. Cells need to tolerate many of these blocking lesions to timely complete DNA replication, postponing their repair for later. This process of lesion bypass during DNA damage tolerance can lead to the accumulation of single-strand DNA (ssDNA) fragments behind the fork, which have to be filled in before chromosome segregation. Homologous recombination plays essential roles both at and behind the fork, through fork protection/lesion bypass and post-replicative ssDNA filling processes, respectively. I review here our current knowledge about the recombination mechanisms that operate at and behind the fork in eukaryotes, and how these mechanisms are controlled to prevent unscheduled and toxic recombination intermediates. A unifying model to integrate these mechanisms in a dynamic, replication fork-associated process is proposed from yeast results.España Gobierno (BFU2015-63698-P
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