69 research outputs found

    Crop diversification and digestate application effect on the productivity and efficiency of irrigated winter crop systems

    Get PDF
    Irrigated winter crops can reduce input demands when compared with irrigated summer cropping systems in the Mediterranean area. The sustainability of these systems can be further improved resorting to diverse rotations, but also to fertilisation with digestate, a by-product from anaerobic digestion of organic waste. Post-treatments such as drying and acidifying can improve the fertiliser value of this product. In this study, we compare wheat performance in a three-year full cereal rotation or in a diverse rotation, with pea and canola. Besides, untreated and dried acidified digestates are tested as fertilisers for all crops, comparing to mineral fertilisation at a rate of 140 kg N ha−1 and a control with no fertilisation. To assess productivity and efficiency of the different systems, grain yield and N concentration, N uptake efficiency (NUpE) and water use efficiency (WUE) were determined, along with soil nitrate dynamics and total N at the end of the experiment. Results showed an average wheat yield increase of 1.79 t ha−1 by the last year of the diverse crop rotation rather than the cereal rotation (p < 0.001). Although there was no yield increase in the previous year, wheat after pea showed higher grain N concentration (p < 0.001). However, the NUpE of wheat remained steady due to a higher soil N availability after pea, which suggests that fertilisation can be adjusted. Although wheat WUE increased due to canola and pea precedents (p < 0.001), the cereal rotations should be more adapted to systems with low water availability. Nonetheless, both rotations required about 30% of irrigated water than the typical irrigated summer crops of the Ebro valley region. Fertiliser effect on yields was variable according to the tested crop mainly due to differences in N demand along each growing cycle. Overall, dried acidified digestate application resulted in similar soil nitrate levels than the mineral fertiliser. The diverse rotation raised soil nitrates content compared to the cereal rotation at sowing and harvesting times (p = 0.002 and p < 0.001, respectively). Higher soil nitrate levels were found when associating these two practices, while nitrate levels after mineral fertilisation showed to be less dependent on the implemented rotation. The diverse rotation also raised soil total N at the end of the experiment (p = 0.023). Similarly, the dried acidified digestate application resulted in higher soil total N than mineral fertilisation (p = 0.011). These findings show how these management practices should allow for a chemical fertilisation reduction in irrigated winter crop systems.This work was supported by the European Union’s Horizon 2020 Research and Innovation programme [Grant Agreement No. 773649] and by the State Agency of Research (Spain) [Projects AGL 2017/84529-C3–3R and PID 2021–126343OB-C33]. G. Nascimento is recipient of an UdL-IRTA PhD fellowship. The IRTA authors acknowledge the CERCA programme (Generalitat de Catalunya) contribution.info:eu-repo/semantics/publishedVersio

    Endmember extraction algorithms from hyperspectral images

    Get PDF
    During the last years, several high-resolution sensors have been developed for hyperspectral remote sensing applications. Some of these sensors are already available on space-borne devices. Space-borne sensors are currently acquiring a continual stream of hyperspectral data, and new efficient unsupervised algorithms are required to analyze the great amount of data produced by these instruments. The identification of image endmembers is a crucial task in hyperspectral data exploitation. Once the individual endmembers have been identified, several methods can be used to map their spatial distribution, associations and abundances. This paper reviews the Pixel Purity Index (PPI), N-FINDR and Automatic Morphological Endmember Extraction (AMEE) algorithms developed to accomplish the task of finding appropriate image endmembers by applying them to real hyperspectral data. In order to compare the performance of these methods a metric based on the Root Mean Square Error (RMSE) between the estimated and reference abundance maps is used

    Endmember extraction algorithms from hyperspectral images

    Get PDF
    During the last years, several high-resolution sensors have been developed for hyperspectral remote sensing applications. Some of these sensors are already available on space-borne devices. Space-borne sensors are currently acquiring a continual stream of hyperspectral data, and new efficient unsupervised algorithms are required to analyze the great amount of data produced by these instruments. The identification of image endmembers is a crucial task in hyperspectral data exploitation. Once the individual endmembers have been identified, several methods can be used to map their spatial distribution, associations and abundances. This paper reviews the Pixel Purity Index (PPI), N-FINDR and Automatic Morphological Endmember Extraction (AMEE) algorithms developed to accomplish the task of finding appropriate image endmembers by applying them to real hyperspectral data. In order to compare the performance of these methods a metric based on the Root Mean Square Error (RMSE) between the estimated and reference abundance maps is used

    Soil Aggregation and Soil Organic Carbon Stabilization: Effects of Management in Semiarid Mediterranean Agroecosystems

    Get PDF
    In semiarid agroecosystems of the Ebro valley (NE Spain) soils are characterized by low soil organic matter (SOM) and a weak structure. In this study we investigated the individual and combined effect of tillage system (no-tillage, NT; reduced tillage, RT; conventional tillage, CT) and cropping system (barley–fallow rotation at the Peñaflor site, PN-BF and continuous barley at the Peñaflor site, PN-BB) on soil organic carbon (SOC) storage as well as the physical protection of SOM fractions by soil aggregates in three long-term experimental sites. In both cropping systems, total SOC content was more than 30% higher in NT compared with CT in the 0- to 5-cm depth. The suppression of fallowing in the PN-BB cropping system led to a greater SOC stabilization only in NT. In all the three sites, greater proportion of water-stable macroaggregates (>250 µm) was found under NT than under CT in the 0- to 5-cm depth. Macroaggregate organic C concentration (250–2000 µm) was greater in NT compared with CT in the BB cropping system, but did not differ with tillage treatment in the PN-BF rotation. Greater proportion of microaggregates within macroaggregates in NT compared with CT was only found in the Agramunt site (AG). However, greater C stabilized inside these microaggregates was observed in AG, Selvanera site (SV), and PN-BB in the 0- to 5-cm depth. The results of this study demonstrate that in the semiarid Mediterranean agroecosystems of the Ebro valley, the adoption of NT together with the suppression of long-fallowing period can significantly increase the amount of SOC stabilized in the soil surface and improve soil structure and aggregation.This research was supported by the Comisión Interministerial de Ciencia y Tecnología of Spain (Grants AGL2001-2238-CO2-01, AGL 2004-07763-C02-02 and AGL2007-66320-CO2-02/AGR) and the European Union (FEDER funds).Peer reviewe

    UNA EXPLICACIÓN ANTROPOLÓGICA DEL EMBARAZO EN ADOLESCENTES EN LA COMARCA DEL MAR MENOR Y CAMPO DE CARTAGENA.

    Get PDF
    Introducción: El cambio en la regulación social de la sexualidad y el cambio producido en la conducta sexual y reproductiva de los jóvenes y sus posibles consecuencias están siendo los factores que más están influyendo en la conceptualización de los adolescentes como un grupo de riesgo por la sociedad y sus conductas como problema. Objetivos Objetivo general: Analizar la influencia de la cultura en la aceptación social y familiar de determinadas conductas relacionadas con el embarazo y parto en jóvenes. Objetivos específicos: 1º.- Conocer el nivel de instrucción de las puérperas menores de veinte años del Área de Salud II de la C.A.R.M. 2º.- Conocer su nivel socioeconómico. 3º.- Conocer la información sobre sexualidad y anticoncepción que poseen. 4º.- Conocer las fuentes de información de que disponen. Material y método: Para dar respuesta a estos interrogantes realizamos un estudio de prevalencia en la población de puérperas de 20 años o menos, que han dado a luz en los hospitales del Área de Salud II de la C.A.R.M., durante los meses de julio a octubre de 1995. Para comparar se elige un grupo control determinado por mujeres que dan a luz durante los mismos dias y en el mismo centro, mayores de 20 años y que no estén en la misma habitación, escogiendo de forma aleatoria a 2 puérperas mayores de 20 años por cada una de las menores (n=132). Se ha efectuado una encuesta para conocer el nivel de instrucción y el nivel socioeconómico de las puérperas en el momento de conocer su embarazo, así como la información que poseen sobre sexualidad y anticoncepción, y las fuentes de esa información. En esta encuesta se establecieron las variables que conforman la medida del nivel socioeconómico. Se ha llevado a cabo un estudio descriptivo de las distintas variables y sus asociaciones, evaluando las diferencias entre el grupo de las jóvenes y el de las adultas, en relación al lugar de residencia, estado civil, nivel de instrucción, nivel socioeconómico, grado de conocimientos, fuentes de información e influencia de las campañas públicas sobre sexualidad y anticoncepción. Hemos realizado un analisis univariante o distribución simple de frecuencias, observando las distribuciones de frecuencias absolutas y relativas en porcentajes para las variables cualitativas y para las variables cuantitativas la media y la desviación típica. Se estudio la diferencia de medias y desviación típica de algunas variables, calculando la "t de Student". Resultados y conclusiones: 1. La mayoría de las puérperas adolescentes, así como sus padres, tienen un nivel de instrucción bajo o son analfabetas, están adscritas a grupos económicos bajo o medio-bajo y presentan un nivel de cualificación profesional mínimo, por lo que podemos concluir que pertenecen a un grupo socioeconómico desfavorecido. 2. La mayoría de las jóvenes no planifica su embarazo ( 65'9%) y de éstas la mayoría no usa métodos anticonceptivos o no los conoce (65'5%). El preservativo y la marcha atrás son los métodos más utilizados. Destacamos que el 34'1% de las adolescentes planificó su embarazo. 3. Cuando aumenta la edad de la mujer, el nivel de estudios y el grupo económico, aumenta el conocimiento sobre sexualidad y anticoncepción. La principal fuente de información es el medio social. 4. Aunque el desconocimiento sobre las campañas publicitarias y charlas sobre sexualidad y anticoncepción es mayoritario para los dos grupos, se acentúa cuando la mujer es menor de veinte años, pertenece a un grupo económico bajo y tiene un nivel de instrucción bajo. En amplias zonas rurales del Campo de Cartagena en tiempos no muy lejanos, el llevarse a la novia ha sido aceptado e incluso provocado por motivos económicos. En la actualidad, ésta es una opción que ya ha caído en desuso (a medida que los niveles de instrucción y económicos han ido elevándose, prevalece más el deseo paterno de que las hijas consigan por sus medios un porvenir independiente), sin embargo, sí ha dejado en el acervo popular la aceptación de éste hecho como algo, si no recomendable, cuando menos no demasiado reprobable

    High-carotenoid maize: development of plant biotechnology prototypes for human and animal health and nutrition

    Get PDF
    Carolight (R) is a transgenic maize variety that accumulates extraordinary levels of carotenoids, including those with vitamin A activity. The development of Carolight (R) maize involved the technical implementation of a novel combinatorial transformation method, followed by rigorous testing for transgene expression and the accumulation of different carotenoid molecules. Carolight (R) was envisaged as a way to improve the nutritional health of human populations that cannot access a diverse diet, but this ultimate humanitarian application can only be achieved after extensive testing for safety, agronomic performance and nutritional sufficiency. In this article, we chart the history of Carolight (R) maize focusing on its development, extensive field testing for agronomic performance and resistance to pests and pathogens, and feeding trials to analyze its impact on farm animals (and their meat/dairy products) as well as animal models of human diseases. We also describe more advanced versions of Carolight (R) endowed with pest-resistance traits, and other carotenoid-enhanced maize varieties originating from the same series of initial transformation experiments. Finally we discuss the further steps required before Carolight (R) can fulfil its humanitarian objectives, including the intellectual property and regulatory constraints that lie in its path

    Association of insularity and body condition to cloacal bacteria prevalence in a small shorebird

    Get PDF
    Do islands harbour less diverse disease communities than mainland? The island biogeography theory predicts more diverse communities on mainland than on islands due to more niches, more diverse habitats and availability of greater range of hosts. We compared bacteria prevalences ofCampylobacter,ChlamydiaandSalmonellain cloacal samples of a small shorebird, the Kentish plover (Charadrius alexandrinus) between two island populations of Macaronesia and two mainland locations in the Iberian Peninsula. Bacteria were found in all populations but, contrary to the expectations, prevalences did not differ between islands and mainland. Females had higher prevalences than males forSalmonellaand when three bacteria genera were pooled together. Bacteria infection was unrelated to bird's body condition but females from mainland were heavier than males and birds from mainland were heavier than those from islands. Abiotic variables consistent throughout breeding sites, like high salinity that is known to inhibit bacteria growth, could explain the lack of differences in the bacteria prevalence between areas. We argue about the possible drivers and implications of sex differences in bacteria prevalence in Kentish plovers

    Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry

    Get PDF
    Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%
    corecore