1,946 research outputs found
When viruses play team sports : mixed infections in plants
Altres ajuts: Generalitat de Catalunya/CERCA ProgrammeThe pathological importance of mixed viral infections in plants might be underestimated except for a few well-characterized synergistic combinations in certain crops. Considering that the host ranges of many viruses often overlap and that most plant species can be infected by several unrelated viruses, it is not surprising to find more than one virus simultaneously in the same plant. Furthermore, dispersal of the majority of plant viruses relies on efficient transmission mechanisms mediated by vector organisms, mainly but not exclusively insects, which can contribute to the occurrence of multiple infections in the same plant. Recent work using different experimental approaches has shown that mixed viral infections can be remarkably frequent, up to the point that they could be considered the rule more than the exception. The purpose of this review is to describe the impact of multiple infections not only on the participating viruses themselves but also on their vectors and on the common host. From this standpoint, mixed infections arise as complex events that involve several cross-interacting players, and they consequently require a more general perspective than the analysis of single-virus/single-host approaches for a full understanding of their relevance
A characterization of distributions based on linear regression of order statistics and record values
We obtain the family of distributions for which the regression of one order statistic on another, not necessarily adjacent, is linear. As a consequence, we present a characterization of uniform distributions on an interval. We also characterize the distributions that appear when we impose the condition of linearity of regression for record values
Investment in roads and traffic safety: linked to economic development? A European comparison
This study analyzes how economic resources invested in roads may affect mortality, depending on the level of economic development of a country. To this end, 23 European countries were classified into two groups—high-income countries and low-income countries—according to their average Gross Domestic Product (GDP) per capita over the period 1998–2016. The economic resources are considered through the investment in construction and the maintenance expenditure. Further variables are included to control for several factors related to the infrastructure, socioeconomics, legislation, and meteorol- ogy. Fixed-effects panel data models were built separately for the interurban road network of each group of countries. These models also capture the international inequalities within each group and the country-specific national trend for the study period. The main results indicate a reduction effect on the fatality rate of road maintenance expenditure (in both groups), and of the investment in construction (in the low-income countries). Other variables—such as proportion of motorways, motorization rate, unemployment rate, GDP per capita, alcohol consumption, Demerit Point System, and mean annual pre- cipitation—showed statistically significant results as well. Finally, the country-specific fixed effects and the country-specific trend were mapped geographically, to better reflect national conditions for achieving lower fatality rates in the high-income countries, and greater progress in reducing fatalities in the low-income countries. In the end, this study provides evidence to policy-makers that can help to achieve a safer and more sustainable transport system, namely, how to tackle an ongoing major problem—traffic-related deaths—when attending and allocating the economic resources that road infrastructure needs.This study was carried out in the framework of the project “Inversión en carreteras y seguridad vial: un análisis internacional (INCASE),” financed by: FEDER/Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de Investigación/Proyecto RTI2018- 101770-B-I00, within Spain´s National Program of R+D+i Oriented to Societal Challenges.
Funding for open access charge: Universidad de Granada / CBUA
Ionic liquid based solvent micro-extraction of Ag and Cd from saline and hypersaline waters
Cadmium (Cd) and silver (Ag) are naturally occurring metals in saline natural waters,
which may present toxic effects even at trace level. Membrane technology has been
widely applied for their extraction, including hollow fiber supported liquid membranes.
However, their application to saline waters is limited. In this work, a hollow fiber liquid
micro-extraction system, with a configuration of 2 phase solvent bar micro-extraction
(2SBME), using the ionic liquid N-methyl-N,N,N-trioctylammonium chloride
(Aliquat® 336), dissolved in kerosene as extractant is proposed to overcome the
limitations of existing HFLPME of Ag and Cd in saline waters.
The use of an ionic liquid solution in the 2SBME leaded to higher stability of the
organic solution in the fiber. The effect of chemical variables on the extraction was
evaluated. Extraction of Cd and Ag with Aliquat® 336 was enhanced by Cl- in the
sample, but it was independent of the concentration of organic matter. Extraction yield
varied in the range 65-80% for Ag, and 45%-95% for Cd, depending on the salinity of
samples. The highest extraction was obtained in seawater samples for 75% Aliquat®
336 dissolved in kerosene with 10% dodecan-1-ol, after 45 minutes, and 800 rpm
stirring rate in the sample. Efficacy of the proposed system when applied to real samples was 88.10±4.14% for Cd, and 61.47±3.00% for Ag in seawater, and
92.73±5.37% for Cd and 64.23±2.85% for Ag in a hyper-saline lagoon (70 g L-1 NaCl).
In conclusion, the proposed methodology allowed a miniaturization of Ag and Cd
extraction in short times, requiring lower amount of reagents and solvents, less energy
as well as reducing operational cost and wastes if compared with existing liquid
membrane based methods
First ground penetrating radar survey on Monte Perdido glacier (Pyrenees)
Producción CientíficaThe project “The Monte Perdido Glacier: Monitoring the glacial dynamic and the associated cryospheric processes as
indicators of global change” (National Park´s 2013 Fund) aims to study the recent dynamic and degradation of this ice
mass, using geomatic and geophysical techniques in order to estimate thickness and potential volumetric variations.
We present the first ground penetrating radar survey, carried out on the northwest section of the lower Monte Perdido
Glacier. The survey was conducted along a 270 m transect, using three antennas of different frequencies -500, 200 and
50 MHz- that enabled us to study the glacier´s structure at various maximum depths and spatial resolutions. The results
show a first section composed by several seasonal snow layers (2015-2016 winter and spring), a clear snow/ice transition layer, an ice layer and a final basal zone characterised by typical sub-glacial till sediments.Ministerio de Agricultura y Pesca, Alimentación y Medio Ambiente (project 844/2013)Junta de Extremadura - Fondo Europeo de Desarrollo Regional (grant GR15107
Anàlisi de les competències professionals dels funcionaris de carrera amb responsabilitat directiva i dels titulars d’òrgans directius de designació política de l’Ajuntament de Palma
Aquest article presenta els resultats d’un estudi realitzat entre els funcionaris de l’Ajuntament de Palma. Té el propòsit de conèixer el perfil competencial dels llocs de responsabilitat, per a la qual cosa s’ha realitzat un estudi transversal descriptiu, basat en una enquesta autoadministrada. La mostra és de siscents tretze funcionaris, cent vint-i-sis dels quals ocupen llocs de responsabilitat i quatre-cents vuitantaset, llocs base. Els resultats obtinguts aporten una valuosa informació per a la creació d’un Sistema de Gestió Integral dels Recursos Humans per competències.Este artículo presenta los resultados de un estudio realizado entre los funcionarios del Ayuntamiento de Palma. Tiene el propósito de conocer el perfil competencial de los puestos de responsabilidad, para ello se ha realizado un estudio transversal descriptivo, basado en una encuesta autoadministrada. La muestra es de seiscientos trece funcionarios, de los cuales ciento veintiséis ocupan puestos de responsabilidad y cuatrocientos ochenta y siete puestos base. Los resultados obtenidos aportan una valiosa información para la creación de un Sistema de Gestión Integral de los Recursos Humanos por competencias
Dietary Intervention through Flipped Learning as a Techno Pedagogy for the Promotion of Healthy Eating in Secondary Education
We acknowledge the researchers of the research group AREA (HUM-672), which belongs to
the Ministry of Education and Science of the Junta de Andalucía and is registered in the Department of Didactics
and School Organization of the Faculty of Education Sciences of the University of Granada.Technological progress in the educational field has led to the application of active and
innovative teaching methods, such as flipped learning, including in the field of dietary education.
This is considered a mixed formative approach that combines face-to-face and outside the classroom
education. The objective of this research was to analyze the effectiveness of flipped learning
methodology on a traditional training practice in dietary training, both in the sixth grade of primary
education and in the fourth level of secondary education. A quasi-experimental design was adopted
with two experimental groups, two control groups and only posttest. The final sample was composed
of 115 students divided into four groups, two of each educational stage mentioned. A didactic unit
consisting of six sessions in all groups was applied. Two different training methodologies were
followed according to the nature of the group (control-traditional; experimental-flipped learning).
The results reveal that flipped learning is effective both in primary education and in secondary
education, being more influential in student development in this last stage. It is concluded that the
flipped learning approach has meant an improvement of the academic indicators evaluated after a
diet education program.This research was funded by I+D+I OTRI-Universidad de Granada CNT-4315. Metodologías activas
para el aprendizaje mediante recursos tecnológicos para el desarrollo de la sociedad
Influence of road investment and maintenance expenses on injured traffic crashes in European roads
Embargo de 12 meses desde su publicacionThis study analyses the influence of economic resources invested in road infrastructures, both in construction and maintenance, upon injured traffic crashes. Furthermore, a set of control variables related to diverse factors was added: infrastructure, socioeconomics, meteorology and legislation. Consistent with this, a panel data model for the interurban network of twenty European countries was built, thus contributing to the literature with a study covering different countries and taking into account the possible effect of traffic regulation changes and alcohol consumption. As significant results, an inverse relationship with the injured traffic crashes has been obtained for the variables of maintenance expenditure, unemployment rate, per capita income and demerit point system, and a direct relationship for investment in construction and alcohol consumption. All things considered, allocating economic resources to road maintenance may be an effective tool to develop of a more sustainable and safer road transport system
How do road infrastructure investments affect Powered Two-Wheelers crash risk?
The drivers of Powered Two-Wheelers (PTWs) pertain to the collective of so-called vulnerable road users. Crashes have scarcely decreased for these roadway users in recent years, whereas among other users, e.g. cars users, they have declined considerably. Meanwhile, the use of PTWs has risen sharply worldwide. This situation adds a further concern to transportation policies and makes evident the need to explore factors involved in PTW crashes. Yet there is a lack of studies specifically about road safety for PTWs. The present study therefore aspires to advance in the knowledge of the factors affecting PTW crashes on interurban roadways, by means of analyzing the effects of some variables not considered previously in this type of studies —mainly economic resources invested in roads—while also accounting specifically for the exposure to risk of PTWs (veh-km), along with relevant variables related to road traffic, the roadway infrastructure, and socioeconomic, meteorological and legislative factors. To this end, and bearing in mind the latest advancements of incorporating unobserved heterogeneity in count data models, different configurations of random parameters negative binomial models for data panels are presented. The realm of study is the network of national roads in Spain, distributed over 43 provinces, and the time period between 2007 and 2015. The results show significant associations for 11 of the variables considered: annual and accumulated investment in construction, expense on maintenance, proportion of motorways, light and heavy vehicle traffic, per capita GDP, age, unemployment rate, price of gasoline, and modification of the demerit point system (DPS). With respect to transport policy implications, the findings provided in this study may serve to monitor the effects of economic resources allocated to road construction and maintenance —along with other measures, such as gasoline prices and DPS—on PTWs safety.This study was carried out in the framework of the project RTI 2018-101770-B-I00 “Investment in roads and road safety: An international analysis (INCASE)”, financed by: MCIN/AEI/10.13039/501100011033/ERDF, within Spain's National Program of R + D + i Oriented to Societal Challenges. Funding for open access charge: Universidad de Granada
Road Investment and Traffic Safety: An International Study
The aim of this study is to analyse whether the economic resources invested in
roads—both investment in construction and expenditure on maintenance and conservation—have any
influence on road fatality rates. Since this is a complex problem, and because there are many factors
that can influence the fatality rate, other variables related to specific transport, socioeconomic and
meteorological factors are also considered. The study was carried out using a panel data model,
modelling road mortality as a function of 12 variables. The scope of the study is international,
focusing on the interurban road network. Data were collected from 23 European countries for the
period 1998–2016. The main results obtained are that both expenditure on road maintenance and
conservation and the proportion of motorways in the total road network contribute to reducing road
mortality. Contrariwise, greater investment in construction leads to an increase in the fatality rate.The authors wish to express their gratitude to the Ministry of Science, Innovation and Universities
for funding received for the project “INVERSIÓN EN CARRETERAS Y SEGURIDAD VIAL: UN ANÁLISIS
INTERNACIONAL (INCASE)”, reference RTI2018-101770-B-I00, within the State Programme for R+D+i Oriented
to the Challenges of Society
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