Aclimatación al frío en diferentes clones de Eucalyptus globulus Labill durante el régimen natural de endurecimiento

En la región mediterránea la principal limitación de la expansión del las plantaciones de Eucalyptus es la ocurrencia periódica de temperaturas bajas durante los meses de invierno (-5 a -10 oC). Por esta razón es crucial implementar un programa para mejorar la resistencia al frío en las especies utilizadas de este género. E. globulus, la especie más extendida en la península ibérica es considerada una especie moderadamente susceptible al frío. Se testaron 16 clones a los cuales se les realizó un seguimiento durante el régimen natural de endurecimiento y la salida del mismo para el periodo 2005-2006. La tolerancia al frío fue evaluada en tejido foliar desarrollado, tanto en hojas pecioladas maduras como en hojas sentadas juveniles, simulando condiciones de helada en ambiente controlado. De esta forma se demostró que existe un proceso de aclimatación de las plantas a las bajas temperaturas a medida que se acumulan las horas de frío y una desaclimatación de las mismas a medida que acaba el invierno. En todos los clones se determinó un máximo de tolerancia para la segunda quincena de enero, lo que corresponde con un total acumulado de 415 horas de frío por debajo de los 7 oC (HF7). Por otra parte se observó un cambio significativo en el umbral de temperaturas que causan un daño al 50% de la superficie del tejido foliar (TL50), siendo el valor medio de éstas -4,5 ºC antes de comenzar la temporada de frío y de – 6,5 ºC una vez alcanzado el máximo de endurecimiento.______________________________The greatest constraint on the expansion of Eucalyptus plantations in the Mediterranean region is the periodic occurrence of low temperatures (–5 to –10 oC) during winter. This has raised the need to launch a programme aimed at increasing the tolerance to cold weather of Eucalyptus species in the region. Eucalyptus globulus, which is the most widespread Eucalyptus species in the Iberian peninsula, is moderately vulnerable to cold. In this work, a total of 16 clones of this species were monitored during their natural hardening regime and at its end over the period 2005–06. Tolerance to cold was evaluated in well-developed tissue of both mature petiolate leaves and seated young leaves by mimicking freezing conditions in a controlled environment. The plants were found to gradually acclimate to low temperatures as the number of cold hours increased and to de-acclimate as the winter neared its end. Tolerance in all clones peaked in the second half of January, after an overall 415 could hours at temperatures below 7 oC (HF7). Also, the temperature threshold below which at least 50% of leaf surface tissue was damaged (TL50) varied markedly, from an average –4.5 oC at the beginning of the cold season to an average –6.5 oC at the point of maximum hardening

DEVELOPMENT AND EVALUATION OF THE ATOS SPONTANEOUS SPEECH CONVERSATIONAL SYSTEM

ABSTRACT In this paper we report our recent development work in Spanish spontaneous speech conversational systems. We describe the Automatic Telephone Operator Service (ATOS) and present the improvements introduced into it to deal with spontaneous speech, which are: (a) a task independent dialogue manager, that can be adapted to a new semantic domain by changing a configuration file. It also generates a prediction about the user's expected utterance to constrain the language model used by the speech recognizer. (b) a language modeling strategy, which allows to adapt the statistical language model to a new task with just few hundreds of sentences. This strategy reduces a 27% the word error rate. We also report the results, conclusions and the speech database collected in the evaluation of the ATOS system, which has been tested by 30 real users

Are the health messages in schoolbooks based on scientific evidence? A descriptive study

<p>Abstract</p> <p>Background</p> <p>Most textbooks contains messages relating to health. This profuse information requires analysis with regards to the quality of such information. The objective was to identify the scientific evidence on which the health messages in textbooks are based.</p> <p>Methods</p> <p>The degree of evidence on which such messages are based was identified and the messages were subsequently classified into three categories: Messages with high, medium or low levels of evidence; Messages with an unknown level of evidence; and Messages with no known evidence.</p> <p>Results</p> <p>844 messages were studied. Of this total, 61% were classified as messages with an unknown level of evidence. Less than 15% fell into the category where the level of evidence was known and less than 6% were classified as possessing high levels of evidence. More than 70% of the messages relating to "Balanced Diets and Malnutrition", "Food Hygiene", "Tobacco", "Sexual behaviour and AIDS" and "Rest and ergonomics" are based on an unknown level of evidence. "Oral health" registered the highest percentage of messages based on a high level of evidence (37.5%), followed by "Pregnancy and newly born infants" (35%). Of the total, 24.6% are not based on any known evidence. Two of the messages appeared to contravene known evidence.</p> <p>Conclusion</p> <p>Many of the messages included in school textbooks are not based on scientific evidence. Standards must be established to facilitate the production of texts that include messages that are based on the best available evidence and which can improve children's health more effectively.</p

Negative responses of highland pines to anthropogenic activities in inland Spain: a palaeoecological perspective

Palaeoecological evidence indicates that highland pines were dominant in extensive areas of the mountains of Central and Northern Iberia during the first half of the Holocene. However, following several millennia of anthropogenic pressure, their natural ranges are now severely reduced. Although pines have been frequently viewed as first-stage successional species responding positively to human disturbance, some recent palaeobotanical work has proposed fire disturbance and human deforestation as the main drivers of this vegetation turnover. To assess the strength of the evidence for this hypothesis and to identify other possible explanations for this scenario, we review the available information on past vegetation change in the mountains of northern inland Iberia. We have chosen data from several sites that offer good chronological control, including palynological records with microscopic charcoal data and sites with plant macro- and megafossil occurrence. We conclude that although the available long-term data are still fragmentary and that new methods are needed for a better understanding of the ecological history of Iberia, fire events and human activities (probably modulated by climate) have triggered the pine demise at different locations and different temporal scales. In addition, all palaeoxylological, palynological and charcoal results obtained so far are fully compatible with a rapid human-induced ecological change that could have caused a range contraction of highland pines in western Iberia

Capitulo 2. Ciencias Naturales y Ciencias Básicas, Ingeniería y Tecnología

La diseminación de la Levitación Magnética, a pesar de lo antiguo de su tecnología, ha sido limitada. Debido a sus inconvenientes prácticos de implementación, su uso es bastante restringido, comparado con otras tecnologías (SCMaglev japonés, Transrapid alemán, o productos comerciales para ocio y entretenimiento). Con el boom de las tecnologías limpias y amigables con el medio ambiente y en concordancia con los objetivos del milenio, es pertinente plantearse el objetivo de optimizar el proceso de Levitación Magnética para generar un aprovechamiento de las ventajas de esta tecnología a nivel mecánico, eléctrico, y ambiental.&nbsp; Actualmente la UNAD adelanta un proyecto de investigación cuyo objetivo es generar un modelo físico matemático de levitación magnética para aplicaciones en ingeniería. De este proyecto se ha derivado una primera revisión sistemática de los principios físicos y los modelos vigentes en Levitación Magnética

Short rotation coppice of leguminous tree Leucaena spp. improves soil fertility while producing high biomass yields in Mediterranean environment

The use of woody nitrogen-fixing plant species as multipurpose and energy crops aims to enhance biomass yield while improving soil properties. Yet, the effectiveness of this option is still under debate especially the use of short rotation cropping in water and nutrient limited environments. This study investigated whether short rotation coppicing of four taxa of multipurpose biomass woody legume Leucaena spp. can improve soil conditions when grown for biomass under a Mediterranean environment. Biomass yield, mineral composition and heat value of the biomass and the mineral and organic matter content of soil were evaluated. Under favorable growing conditions, woody dry biomass production was up to 29 Mg ha(-1) year(-1) with slight but significant differences between the four taxa that were tested. After 11 years of cropping, the soil showed higher fertility and microbial activity compared to the uncropped plot. Leucaena cultivation increased soil nitrogen by 35 %, dehydrogenase activity by 98 %, and organic matter and carbon content (by 41 %). Annual cuttings resulted in the highest biomass production, followed by two and three year cuttings. The mineral composition and the calorific capacity of woody biomass make it suitable for commercial use as an energy source (generating on average 151 MW h ha(-1) year(-1)). In conclusion, short rotation coppicing of nitrogen-fixing woody species results in high biomass production rates with the restoration of degraded soils, constituting a sustainable agroforestry system for rural areas.This work was partially supported by the Autonomous Community of Andalusia (C01-121 and RNM-6398), and by the projects CTQ 201346804-C2-1-R, CTQ 2017-85251-C2-2-R of the Spanish Ministry of Economy and Competitiveness, all of which were co-financed with ERDF funds (European Regional Development Funds).Peer reviewe

Efecto del riego y la fertilización en el crecimiento de Eucalyptus x urograndis como cultivo energético en Huelva

En un terreno de suelo franco-arenoso, bajo clima mediterráneo con influencia atlántica, se estudió, durante dos años, la producción de biomasa de un clon de Eucalyptus x urograndis, cultivado a una densidad de 2500 pies ha-1. Partiendo de plantas de un año de edad, de diámetro 63.4 ± 8 mm y altura 4.6 ± 0.5 m, en un diseño factorial completo, se aplicaron 12 tratamientos de cultivo con cuatro niveles de riego (R0: control sin regar; R1: 325 mm; R2: 646 mm; R4: 1298 mm) y tres de fertilización (F0: control sin fertilizar; F1: 150 kg ha-1 de N; F2: 300 kg ha-1 de N). El riego se aplicó cada año de abril a septiembre y la fertilización en equilibrio 16-8-12. La precipitación anual de cada año fue 510 mm y 326 mm, respectivamente. Se llevó un seguimiento del crecimiento en altura (H) y diámetro (D) y se establecieron ecuaciones alométricas para relacionarlos con la biomasa seca aérea. La producción de biomasa seca aérea mostró diferencias significativas entre riegos (p < 0.001) y fertilizaciones (p < 0.001), pero no para la interacción riego x fertilización (p = 0.134). Los incrementos de biomasa se movieron en un rango de 20.6 t ha-1 año-1 para R0F0 a 55.4 t ha-1 año-1 para R4F2. La combinación de riego y fertilización tuvo efecto sinérgico aumentando la eficiencia en el uso de los recursos de las plantas. Estos datos pueden ayudar a ajustar las dosis óptimas de riego y fertilización en las plantaciones

Initiation of translation Efficiency in different Hepatitis C virus genotypes isolated from interferon responders and non-responder patients

Initiation of translation of hepatitis C viral RNA occurs internally and it is mediated by a segment of about 330 nucleotides termed Internal Ribosome Entry Site (IRES) located in the 5' end region. While being the most conserved part of the genome, this region also accumulates nucleotide substitutions which are often covariant. In this study we have examined the activity and sequence variation of IRES elements belonging to genotypes 1b, 2a/2c and 3a in patients that responded or not to interferon therapy. The substitutions found in the IRES region analyzed were predicted to maintain the secondary structure of the RNA. Comparison of their efficiency to promote internal initiation of translation in bicistronic constructs supported the conclusion that for both 1b and 3a genotypes, response to interferon therapy and IRES activity are unrelated, although sequence homology was not always found among isolates from patients with different type of response. IRES activity of the studied genotypes varied about 4-fold under the conditions used in our in vivo assays depending on the cell line used for transfection. Such differences were not evidenced in vitro suggesting that the differences observed depend on trans-acting factors present in the transfected cell

Evaluating the apparent diffusion coefficient in MRI studies as a means of determining paediatric brain tumour stages

Background: The apparent diffusion coefficient (ADC) in MRI seems to be related to cellularity in brain tumours. Its utility as a tool for distinguishing between histological types and tumour stages remains controversial. Procedures: We retrospectively evaluated children diagnosed with CNS tumours between January 2008 and December 2013. Data collected were age, sex, histological diagnosis, and location of the tumour. We evaluated the ADC and ADC ratio and correlated those values with histological diagnoses. Results: The study included 55 patients with a median age of 6 years. Histological diagnoses were pilocytic astrocytoma (40%), anaplastic ependymoma (16.4%), ganglioglioma (10.9%), glioblastoma (7.3%), medulloblastoma (5.5%), and other (20%). Tumours could also be classified as low-grade (64%) or high-grade (36%). Mean ADC was 1.3 for low-grade tumours and 0.9 for high-grade tumours (P = .004). Mean ADC ratios were 1.5 and 1.2 for low and high-grade tumours respectively (P = .025). There were no significant differences in ADC/ADC ratio between different histological types. Conclusion: ADC and ADC ratio may be useful in imaging-study based differential diagnosis of low and high-grade tumours, but they are not a substitute for an anatomical pathology study. Resumen: Introducción: El coeficiente de difusión aparente (ADC) de la resonancia magnética parece relacionarse con el grado de celularidad de los tumores de sistema nervioso central. Su utilidad para diferenciar el grado tumoral y tipo histológico de los tumores es controvertido. Material y métodos: Estudio retrospectivo de los pacientes pediátricos con diagnóstico de tumor de sistema nervioso central desde enero-2008 a diciembre-2013. Se revisan edad, sexo, localización del tumor y anatomía patológica. Las medidas de ADC y ratio ADC (cociente ADC tumoral/ADC tejido sano) se llevaron a cabo por 2 neurorradiólogos expertos, ciegos al diagnóstico histológico. Se calcula el valor ADC y el ratio ADC y se comparan sus valores con los diagnósticos anatomopatológicos. Resultados: Se incluyen 55 pacientes. La mediana de edad fue 6 años. Los diagnósticos anatomopatológicos fueron: astrocitoma pilocítico (40%), ependimoma anaplásico (16,4%), ganglioglioma (10,9%), glioblastoma (7,3%), meduloblastoma (5,5%), y otros (20%). El 64% fueron de bajo grado (BG) y el 36% de alto grado (AG). La media de ADC fue 1,3 en los de BG y 0,9 en los de AG (p = 0,004). La media de ratio ADC fue de 1,5 y 1,2 (p = 0,025) respectivamente. No hubo diferencias significativas en el ADC/ratio ADC entre los distintos tipos histológicos. Conclusiones: El ADC y ratio ADC son una herramienta útil en la diferenciación por imagen del grado tumoral en los tumores cerebrales pediátricos, sin sustituir a la anatomía patológica. Keywords: Apparent diffusion coefficient, Brain tumours, Children, Magnetic resonance imaging, Palabras clave: Coeficiente de difusión aparente, Tumores cerebrales, Niños, Resonancia magnétic