470 research outputs found
Determining Immune and miRNA Biomarkers Related to Respiratory Syncytial Virus (RSV) Vaccine Types
The Challenge of Machine Learning in Space Weather Nowcasting and Forecasting
The numerous recent breakthroughs in machine learning (ML) make imperative to
carefully ponder how the scientific community can benefit from a technology
that, although not necessarily new, is today living its golden age. This Grand
Challenge review paper is focused on the present and future role of machine
learning in space weather. The purpose is twofold. On one hand, we will discuss
previous works that use ML for space weather forecasting, focusing in
particular on the few areas that have seen most activity: the forecasting of
geomagnetic indices, of relativistic electrons at geosynchronous orbits, of
solar flares occurrence, of coronal mass ejection propagation time, and of
solar wind speed. On the other hand, this paper serves as a gentle introduction
to the field of machine learning tailored to the space weather community and as
a pointer to a number of open challenges that we believe the community should
undertake in the next decade. The recurring themes throughout the review are
the need to shift our forecasting paradigm to a probabilistic approach focused
on the reliable assessment of uncertainties, and the combination of
physics-based and machine learning approaches, known as gray-box.Comment: under revie
The Solar Spectrum in the Atacama Desert
The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0?5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Iza?a Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons
Percepción de los estudiantes universitarios de la Región de Murcia sobre los valores educativos que pueden transmitir los Juegos Olímpicos. Aplicaciones prácticas.
Se conoce muy poco sobre la valoración de los Ideales Olímpicos por parte de la sociedad española. Incluso, podemos apreciar que existen diversas interrogantes sobre el Olimpismo y la formación recibida por los estudiantes en Ciencias de la Actividad Física y del Deporte durante su etapa universitaria: ¿De qué manera el Movimiento Olímpico puede participar en el proceso enseñanza-aprendizaje? ¿Qué Valores Olímpicos pueden ser desarrollados a través de la enseñanza primaria, secundaria y universitaria? El objetivo de nuestro estudio se centra en conocer la opinión que tienen los alumnos universitarios de CAFyD, Magisterio de E.F. y Magisterio de Primaria de la Región de Murcia, sobre los valores educativos que pueden transmitir los JJOO, así como plantear diversas actividades prácticas que puedan motivar a los futuros docentes en el desarrollo del ideario olímpico en las aulas.------------------------------------------------------------------------------- Very little is known about the valuation of Olympic Ideals by Spanish society. Even, we can see that there are several questions about Olympism and the training received by students in exercise science and sports during his college: How the Olympic Movement can participate in the teaching-learning process? What Olympic Values can be developed through the primary, secondary and university? The aim of our study focuses on getting feedback have CAFyD and Primary Education college students of the Region of Murcia, on the educational values that can transmit the Olympics and raise several practical activities that can motivate future teachers in developing the Olympic ideals in the classroom.Artículo revisado por pare
Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure
Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 104 hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF
Application of lca methodology to the production of strawberry on substrates with peat and sediments from ports
The Life Cycle Assessment (LCA) methodology was applied to identify the potential environmental impact of dredged sediments used as growing media for food crops. The dredged sediments used came from Livorno port and were previously phytoremediated. For the assay, strawberry plants (Fragaria x ananassa Duch vr. ‘San Andreas’) were used. The plants were cultivated on three different substrates (100% peat, 100% dredged sediment and 50% mix peat/sediment) to identify the real impact of the culture media on the growing process. LCA was calculated and analyzed according to ISO 14040:2006 by SimaPro software. ReCipe Midpoint (E) V1.13/Europe Recipe E method was applied. One kilogram of produced strawberry, for each crop media tested, was defined as the functional unit. Eighteen impact categories were selected where Marine Eutrophication (ME), Human Toxicity (HT) and Freshwater Ecotoxicity (FET) were identified as relevant impact categories. The LCA results showed an increase in the environmental impact of strawberry cultivation using 100% sediment against 100% peat, due to the decrease in fruit production caused by the sediment. Nevertheless, the decrease in the environmental impact and the fruit production increase identified when the sediment is used mixed (<50%) with other substrates. The appropriate use of these substrates would be justified within the context of the circular economy
Putative Nitrogen-Fixing Bacteria Associated With the Rhizosphere and Root Endosphere of Wheat Plants Grown in an Andisol From Southern Chile
Acidic ash derived volcanic soils (Andisols) support 50% of cereal production in Chile. Nitrogen (N) is essential for cereal crops and commonly added as urea with consequent environmental concerns due to leaching. Despite the relevance of N to plant growth, few studies have focused on understanding the application, management and ecological role of N2-fixing bacterial populations as tool for improve the N nutrition of cereal crops in Chile. It is known that N2-fixing bacteria commonly inhabits diverse plant compartments (e.g., rhizosphere and root endosphere) where they can supply N for plant growth. Here, we used culture-independent and dependent approaches to characterize and compare the putative N2-fixing bacteria associated with the rhizosphere and root endosphere of wheat plants grown in an Andisol from southern Chile. Our results showed significantly greater bacterial loads in the rhizosphere than the root endosphere. Quantitative PCR results indicated that the copy number of the 16S rRNA gene ranged from 1012~1013 and 107~108 g−1 sample in rhizosphere and root endosphere, respectively. The nifH gene copy number ranged from 105~106 and 105 g−1 sample in rhizosphere and root endosphere, respectively. The total culturable bacteria number ranged from 109~1010 and 107~108 CFU g−1 sample in rhizosphere and 104~105 and 104 CFU g−1 sample in root endosphere using LB and NM-1 media, respectively. Indirect counts of putative N2-fixing bacteria were 103 and 102~103 CFU g−1 sample in rhizosphere and root endosphere using NFb medium, respectively. Sequencing of 16S rRNA genes from randomly selected putative N2-fixing bacteria revealed the presence of members of Proteobacteria (Bosea and Roseomonas), Actinobacteria (Georgenia, Mycobacterium, Microbacterium, Leifsonia, and Arthrobacter), Bacteroidetes (Chitinophaga) and Firmicutes (Bacillus and Psychrobacillus) taxa. Differences in 16S rRNA and putative nifH-containing bacterial communities between rhizosphere and root endosphere were shown by denaturing gradient gel electrophoresis (DGGE). This study shows a compartmentalization between rhizosphere and root endosphere for both the abundance and diversity of total (16S rRNA) and putative N2-fixing bacterial communities on wheat plants grown in Chilean Andisols. This information can be relevant for the design and application of agronomic strategies to enhance sustainable N-utilization in cereal crops in Chile
Trypanosoma cruzi Infection in an Indigenous Kariña Community in Eastern Venezuela
We investigated the seroprevalence of Trypanosoma cruzi infection in an indigenous Kariña population in eastern Venezuela. A total of 175 serum samples were collected in the community of Piñantal during February 2009. Interviews targeting socioeconomic and environmental factors associated with the T. cruzi transmission were also conducted. Samples were evaluated using trypomastigote excreted/secreted antigens (TESAs) in an ELISA format. TESA-ELISA positive samples were confirmed by indirect haemagglutination (HAI) (Wiener). A nonsystematic collection of vectors was also undertaken. T. cruzi seroprevalence was 7.43% according to both assays, and the mean age of infected patients was 48.61±10.40 years (range 34 to 73 years). The vector infection rate was 20.00% (2/10). T. cruzi seropositivity was associated with a history of triatomine bites, the ability to recognize the vector and poor knowledge about Chagas disease, but no associations were found with gender, house type, knowledge of how the disease is transmitted, or the presence of vectors or animals inside dwellings. To our knowledge, this is the first study of the seroprevalence of T. cruzi in an indigenous population in eastern Venezuela. All of the epidemiological variables required for the establishment of active vectorial transmission of T. cruzi were present in this community
Antecedentes de los valores olímpicos en la Grecia Clásica y su proyección en el olimpismo moderno
Actualmente, el Movimiento Olímpico identifica tres valores fundamentales que definen el Olimpismo: excelencia, amistad y respeto. Muchas investigaciones analizan la inclusión de los valores olímpicos en los textos y conferencias de Pierre de Coubertin, sin embargo, poco se ha escrito sobre los valores asociados a la práctica física y competitiva en la Grecia Clásica y la vinculación de estos con los valores del ideario olímpico moderno. Este trabajo estudia la pervivencia de aquellos valores clásicos dentro de los que hoy recoge el Movimiento Olímpico y cómo podemos establecer un paralelismo entre los valores defendidos por el Olimpismo moderno y el código ético subyacente en la literatura grecolatina, en cuanto a la actividad física y la celebración de los certámenes atléticos.---------------------------------------------------------------------------------Currently, the Olympic Movement has identified three core values that define Olympism: excellence, friendship and respect. Many studies analyzed the inclusion of the olympic values in texts and lectures of Pierre de Coubertin, however, little has been written about the values associated with the physical and competitive practice in Classical Greece and linking these with the values of ideology modern olympic. This article studies the survival of those classic values within which today includes the Olympic Movement and how we can establish a parallelism between the values defended by the modern Olympism and the underlying ethical code in the Greco-Roman literature regarding physical activity and celebration athletic contests. Artículo revisado por pare
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