352 research outputs found
Fenología anual y actividad nictemeral de los Hymenoptera (Insecta) en un bosque mixto mediterráneo
El Parque de Collserola es un espacio natural adyacente a la ciudad de Barcelona que recientemente ha sido declarado Parque Natural. El presente estudio se centra en las familias de Hymenoptera muestreadas en un bosque mixto mediterráneo de Pinus-Quercus. Desde mayo de 2009 hasta abril de 2010 se muestreó en el dosel y sotobosque del sitio de estudio: los himenópteros fueron el segundo grupo en abundancia por detrás de los dípteros. Se discute la fenología anual y la actividad nictemeral de las familias más abundantes de Hymenoptera. Un total de 7796 especímenes (6933 en trampa Malaise del sotobosque; 863 en trampa Malaise entre sotobosque y dosel) fueron capturados durante el estudio, repartidos en 37 familias. El sotobosque resultó ser el estrato donde tiene lugar la mayor parte de la actividad de los himenópteros (88,9%). La mayor parte de familias capturadas resultaron ser endo- o ectoparasitoides de un amplio espectro de hospedadores. Aunque la tendencia de los himenópteros sea presentar una mayor actividad durante los meses más cálidos del año, las distintas familias mostraron curvas de actividad particulares, con picos que oscilan entre junio y agosto a excepción de los Xyelidae, que fueron recolectados en febrero. Diapriidae resultó ser la familia más abundante en ambos muestreos, con un total de 2507 especímenes, seguida de los Braconidae (1025). Diapriidae mostró una preferencia por la actividad crepuscular y nocturna de mayo a agosto, mientras que en los Braconidae existe una evolución de su actividad pasando de ser vespertina y crepuscular en mayo a diurna en agosto.Collserola is a natural area adjacent to the city of Barcelona, and has recently declared Natural Park. This study focuses on Hymenoptera families sampled in a Mediterranean mixed forest of Pinus-Quercus. From May 2009 to April 2010 were sampled in the canopy and understory, being Hymenoptera the second group in abundance behind the Diptera. We discuss the annual phenology and nictemeral activity of the most abundant families. A total of 7,796 specimens (6,933 with Malaise trap in the understory; 863 with Malaise trap in the canopy) were captured during the study, divided into 37 families. Understory was the layer where we observed increased activity of the Hymenoptera (88.9%). Most families were found to be endo or ectoparasitoids with a wide range of guests. Although the trend of the Hymenoptera is present greater activity during the warmer months of the year, the different families showed specific activity curves, with peaks ranging between June and August except for Xyelidae that were collected in February. Diapriidae proved to be the most abundant family in both samples, with a total of 2,507 specimens, followed by Braconidae (1,025). Diapriidae showed a preference for crepuscular and nocturnal activity from May to August, while Braconidae shows an evolution in the activity, changing from evening and crepuscular in May, to diurnal in August
Annual phenology and nictemeral activity of the Hymenoptera (Insecta) in a Mediterranean mixed forest
El Parque de Collserola es un espacio natural adyacente a la ciudad de Barcelona que recientemente ha sido declarado Parque Natural. El presente estudio se centra en las familias de Hymenoptera muestreadas en un bosque mixto mediterráneo de Pinus-Quercus. Desde mayo de 2009 hasta abril de 2010 se muestreó en el dosel y sotobosque del sitio de estudio: los himenópteros fueron el segundo grupo en abundancia por detrás de los dípteros. Se discute la fenología anual y la actividad nictemeral de las familias más abundantes de Hymenoptera. Un total de 7796 especímenes (6933 en trampa Malaise del sotobosque; 863 en trampa Malaise entre sotobosque y dosel) fueron capturados durante el estudio, repartidos en 37 familias. El sotobosque resultó ser el estrato donde tiene lugar la mayor parte de la actividad de los himenópteros (88,9%). La mayor parte de familias capturadas resultaron ser endo- o ectoparasitoides de un amplio espectro de hospedadores. Aunque la tendencia de los himenópteros sea presentar una mayor actividad durante los meses más cálidos del año, las distintas familias mostraron curvas de actividad particulares, con picos que oscilan entre junio y agosto a excepción de los Xyelidae, que fueron recolectados en febrero. Diapriidae resultó ser la familia más abundante en ambos muestreos, con un total de 2507 especímenes, seguida de los Braconidae (1025). Diapriidae mostró una preferencia por la actividad crepuscular y nocturna de mayo a agosto, mientras que en los Braconidae existe una evolución de su actividad pasando de ser vespertina y crepuscular en mayo a diurna en agosto.Collserola is a natural area adjacent to the city of Barcelona, and has recently declared Natural Park. This study focuses on Hymenoptera families sampled in a Mediterranean mixed forest of Pinus-Quercus. From May 2009 to April 2010 were sampled in the canopy and understory, being Hymenoptera the second group in abundance behind the Diptera. We discuss the annual phenology and nictemeral activity of the most abundant families. A total of 7,796 specimens (6,933 with Malaise trap in the understory; 863 with Malaise trap in the canopy) were captured during the study, divided into 37 families. Understory was the layer where we observed increased activity of the Hymenoptera (88. 9%). Most families were found to be endo or ectoparasitoids with a wide range of guests. Although the trend of the Hymenoptera is present greater activity during the warmer months of the year, the different families showed specific activity curves, with peaks ranging between June and August except for Xyelidae that were collected in February. Diapriidae proved to be the most abundant family in both samples, with a total of 2,507 specimens, followed by Braconidae (1,025). Diapriidae showed a preference for crepuscular and nocturnal activity from May to August, while Braconidae shows an evolution in the activity, changing from evening and crepuscular in May, to diurnal in August
urg1: a uracil-regulatable promoter system for fission yeast with short induction and repression times.
BACKGROUND: The fission yeast Schizosaccharomyces pombe is a popular genetic model organism with powerful experimental tools. The thiamine-regulatable nmt1 promoter and derivatives, which take >15 hours for full induction, are most commonly used for controlled expression of ectopic genes. Given the short cell cycle of fission yeast, however, a promoter system that can be rapidly regulated, similar to the GAL system for budding yeast, would provide a key advantage for many experiments. METHODOLOGY/PRINCIPAL FINDINGS: We used S. pombe microarrays to identify three neighbouring genes (urg1, urg2, and urg3) whose transcript levels rapidly and strongly increased in response to uracil, a condition which otherwise had little effect on global gene expression. We cloned the promoter of urg1 (uracil-regulatable gene) to create several PCR-based gene targeting modules for replacing native promoters with the urg1 promoter (Purg1) in the normal chromosomal locations of genes of interest. The kanMX6 and natMX6 markers allow selection under urg1 induced and repressed conditions, respectively. Some modules also allow N-terminal tagging of gene products placed under urg1 control. Using pom1 as a proof-of-principle, we observed a maximal increase of Purg1-pom1 transcripts after uracil addition within less than 30 minutes, and a similarly rapid decrease after uracil removal. The induced and repressed transcriptional states remained stable over 24-hour periods. RT-PCR comparisons showed that both induced and repressed Purg1-pom1 transcript levels were lower than corresponding P3nmt1-pom1 levels (wild-type nmt1 promoter) but higher than P81nmt1-pom1 levels (weak nmt1 derivative). CONCLUSIONS/SIGNIFICANCE: We exploited the urg1 promoter system to rapidly induce pom1 expression at defined cell-cycle stages, showing that ectopic pom1 expression leads to cell branching in G2-phase but much less so in G1-phase. The high temporal resolution provided by the urg1 promoter should facilitate experimental design and improve the genetic toolbox for the fission yeast community
Matching in vitro bioaccessibility of polyphenols and antioxidant capacity of soluble coffee by Boosted Regression Trees
The aim of this study was to evaluate changes in polyphenol profile and antioxidant capacity of five soluble coffees throughout a simulated gastro-intestinal digestion, including absorption through a dialysis membrane. Our results demonstrate that both polyphenol content and antioxidant capacity were characteristic for each type of studied coffee, showing a drop after dialysis. Twenty-seven compounds were identified in coffee by HPLC-MS, while only 14 of them were found after dialysis. Green+roasted coffee blend and chicory+coffee blend showed the highest and lowest content of polyphenols and antioxidant capacity before in vitro digestion and after dialysis, respectively. Canonical correlation analysis showed significant correlation between the antioxidant capacity and the polyphenol profile before digestion and after dialysis. Furthermore, boosted regression trees analysis (BRT) showed that only four polyphenol compounds (5-p-coumaroylquinic acid, quinic acid, coumaroyl tryptophan conjugated, and 5-O-caffeoylquinic acid) appear to be the most relevant to explain the antioxidant capacity after dialysis, these compounds being the most bioaccessible after dialysis. To our knowledge, this is the first report matching the antioxidant capacity of foods with the polyphenol profile by BRT, which opens an interesting method of analysis for future reports on the antioxidant capacity of foods.Fil: Podio, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; ArgentinaFil: López Froilán, Rebeca. Universidad Complutense de Madrid; EspañaFil: Ramirez Moreno, Esther. Universidad Autónoma de Estado de Hidalgo; México. Universidad Complutense de Madrid; EspañaFil: Bertrand, Lidwina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Baroni, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; ArgentinaFil: Pérez Rodríguez, María L.. Universidad Complutense de Madrid; EspañaFil: Sánchez Mata, María Cortes. Universidad Complutense de Madrid; EspañaFil: Wunderlin, Daniel A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentin
Antiangiogenic Therapy in Epithelial Ovarian Cancer
Approximately 75% of women with ovarian cancer are diagnosed at advanced stages (FIGO stage III/IV), with 15-23 months median global survival and 20% 5-year survival. Angiogenesis plays an important role in tumour development and proliferation. Increased angiogenesis is associated with worse clinical outcome in ovarian cancer. Here we review the play of bevacizumab in the treatment of ovarian cancer and also other antiangiogenic drugs. In total, to date there are no promising results for most of the reviewed antiangiogenic agents, except those already known for bevacizumab, trebananib, pazopanib, cediranib and nintedanib. Ongoing research will shed more light on this fascinating tumour process and its control
Multisynchronization of Chaotic Oscillators via Nonlinear Observer Approach
The goal of this work is to synchronize a class of chaotic oscillators in a master-slave scheme, under different initial conditions, considering several slaves systems. The Chen oscillator is employed as a benchmark model and a nonlinear observer is proposed to reach synchronicity between the master and the slaves’ oscillators. The proposed observer contains a proportional and integral form of a bounded function of the synchronization error in order to provide asymptotic synchronization with a satisfactory performance. Numerical experiments were carried out to show the operation of the considered methodology
Improving Spanish Polarity Classification Combining Different Linguistic Resources
Sentiment analysis is a challenging task which is attracting
the attention of researchers. However, most of work is only focused on
English documents, perhaps due to the lack of linguistic resources for
other languages. In this paper, we present several Spanish opinion mining
resources in order to develop a polarity classification system. In addition,
we propose the combination of different features extracted from each
resource in order to train a classifier over two different opinion corpora.
We prove that the integration of knowledge from several resources can
improve the final Spanish polarity classification system. The good results
encourage us to continue developing sentiment resources for Spanish, and
studying the combination of features extracted from different resourcesMinisterio de Economía y Competitividad TIN2012-38536-C03-0Junta de Andalucía P11-TIC-7684Universidad de Jaén CEATIC-2013-0
Effects of semen processing on sperm function: Differences between swim-up and density gradient centrifugation
Purpose: Andrology research has evolved notoriously in the latest years, particularly since male factor contribution to couple infertility has been undoubtedly demonstrated. However, sperm function investigations results are sometimes contradictory, probably as a result of the use of different sperm processing techniques. In this work, we underwent a systematic functional comparison of human sperm samples simultaneously processed by swim-up and density gradient centrifugation, which are the preferred sperm processing methods used in basic and clinical laboratories. Materials and Methods: To compare functional characteristics of sperm isolated by swim-up and density gradient centrifugation followed by incubation at different times under capacitating conditions. Results: Semen samples processed in parallel by these two procedures resulted in sperm preparations with significant differences in redox state, spontaneous intracellular calcium oscillations, hyperactivation, protein tyrosine phosphorylation, and acrosome reaction responsivity to calcium ionophore. Such differences showed time-dependent specific patterns for spontaneous intracellular calcium oscillations, hyperactivation and protein tyrosine phosphorylation. Sperm retrieved by density gradient centrifugation showed more hyperactivation and tyrosine phosphorylation than swim-up sperm, suggesting a higher degree of capacitation. Conclusions: Our results account for functional differences observed in spermatozoa processed with these two methods and therefore may contribute to a better interpretation of outcomes obtained in different laboratories as well as to improve experimental designs aimed to study sperm physiology and fertility potential.Fil: Hernández Silva, Gabriela. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: López Torres, Aideé S.. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: Maldonado Rosas, Israel. Centro de Innovación Tecnológica y Medicina Reproductiva; MéxicoFil: Mata Martínez, Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Larrea, Fernando. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: Torres Flores, Víctor. Universidad Nacional Autónoma de México; MéxicoFil: Treviño, Claudia L.. Universidad Nacional Autónoma de México; MéxicoFil: Chirinos, Mayel. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; Méxic
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