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Search Results: 1 - 10 of 489214 matches for " Eduardo Santamaría-Del-ángel "
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Changes in the Composition and Abundance of Phytoplankton in a Coastal Lagoon of Baja California, México, during 2011  [PDF]
María Fernanda Gracia-Escobar, Roberto Millán-Nú?ez, Enrique Valenzuela-Espinoza, Adriana González-Silvera, Eduardo Santamaría-delngel
Open Journal of Marine Science (OJMS) , 2015, DOI: 10.4236/ojms.2015.52014
Abstract: A time series with weekly sampling was conducted from February 20, to December 16, 2011 at a station in the interior of the San Quintín Bay to estimate seasonal changes in the composition and abundance of phytoplankton. Water temperature was recorded and the upwelling index was calculated for the period. Phytoplankton abundance was estimated and phytoplankton were identified by using an inverted microscope and the CHEMTAX program. There were 16 positive phytoplankton anomalies during the year, but only three were considered to be blooms. The blooms were dominated by diatoms and were recorded in the winter, spring and summer. Different genera composed 80% of the total phytoplankton abundance of each of the blooms. The first bloom consisted of diatoms of the genera Pseudo-nitzschia sp. (15.7%), Skeletonema sp. (14.6%), Eucampia sp. (7%), and Navicula sp. (7%); a haptophyte of the genus Imantonia sp. (13.1%); and dinoflagellates of the genus
Changes in the Abundance and Composition of Phytoplankton in a Coastal Lagoon during Neap-Spring Tide Conditions  [PDF]
María Fernanda Gracia-Escobar, Roberto Millán-Nú?ez, Adriana González-Silvera, Eduardo Santamaría-delngel, Víctor F. Camacho-Ibar, Charles C. Trees
Open Journal of Marine Science (OJMS) , 2014, DOI: 10.4236/ojms.2014.42010
Abstract:

The objective of this work was to estimate the changes in abundance and composition of phytoplankton in a coastal lagoon in Baja California, México during neap-spring tide conditions. Sampling was conducted from the 7th to the 16th of October 2004. Surface water was collected at 18 stations distributed across the bay during day time at high tide. Also, a time series was collected at a fixed station; surface water was collected every two hours from 8:00 to 18:00. High temperatures, low salinities and low nutrient concentrations at the oceanic end indicated weak or non upwelling conditions during this period. The phytoplankton community was characterized using an inverted microscope and the chemical taxonomy program CHEMTAX, based on pigment concentration estimated by high performance liquid chromatography (HPLC). The phytoplankton concentration was two times lower during this period than during periods of upwelling in the same year. Cryptophytes and diatoms were the most abundant groups estimated by CHEMTAX. Statistical analyses of the effect of tidal conditions on phytoplankton composition indicate that Zone A is strongly affected by tides, and that tidal effects are lessened at the inner zones. Differences in phytoplankton abundance between zones and between tidal conditions indicate that phytoplankton distribution is patchy in the lagoon.

Macronutrient uptake and carotenoid/chlorophyll a ratio in the dinoflagellate Amphidinium carteri Hulburt, cultured under different nutrient and light conditions
Valenzuela-Espinoza, Enrique;Millán-Nú?ez, Roberto;Santamaría-delngel, Eduardo;Trees, Charles C.;
Hidrobiológica , 2011,
Abstract: population growth, macronutrient (,) uptake and carotenoids/chlorophyll a ratio we determined in amphidinium carteri hulburt, cultured under conditions of continuous light (50, 150, 300 and 750 μmol quanta m-2 s-1) and three nutrient concentrations nano3/nah2po4 at 441.5/18.1 μm (low) 883/36.3 μm (medium) and 1766/72.6 μm (high). both nutrient and irradiance had a significant effect (p < 0.05) on cellular abundance during the period of culture, except for the fourth and seventh day for nutrients (p > 0.05). in cultures under low nutrient condition, no- and po4- were almost depleted by the fifth day and in cultures with medium nutrient this condition occurred in the sixth day; whereas, at high nutrient condition the nutrients were not depleted. we concluded that a. carteri had higher growth rates and nutrient consumption at 300 μmol quanta m-2 s-1 during the first five days and in general the effect of nutrients on the pigment ratios was not significant (p > 0.05). however, the average peridinin/chla ratio decreased up to 72% from the lowest and the highest irradiance. the opposite was observed for the average of diadinoxanthin/chla ratio that increased almost two-fold, and the averages dinoxanthin and diatoxanthin to chla ratios that increased from low to high irradiances. the average diatoxanthin/chla ratio at 750 μmol quanta m-2 s-1 increased up to 2.7-fold from the exponential to the stationary phase only in the low and medium nutrient concentration. likewise, the average peridinin, dinoxanthin and diatoxanthin to chla ratios were not significantly different at 50 and 150 μmol quanta m-2 s-1. these results indicate important changes in average carotenoids/chla ratios in a. carteri cultured under different irradiances.
Macronutrient uptake and carotenoid/chlorophyll a ratio in the dinoflagellate Amphidinium carteri Hulburt, cultured under different nutrient and light conditions Consumo de macronutrientes y proporción de carotenoides/clorofila a en el dinoflagelado Amphidinium carteri Hulburt, cultivado bajo diferentes condiciones de luz y nutrientes
Enrique Valenzuela-Espinoza,Roberto Millán-Nú?ez,Eduardo Santamaría-delngel,Charles C. Trees
Hidrobiológica , 2011,
Abstract: Population growth, macronutrient (,) uptake and carotenoids/chlorophyll a ratio we determined in Amphidinium carteri Hulburt, cultured under conditions of continuous light (50, 150, 300 and 750 μmol quanta m-2 s-1) and three nutrient concentrations NaNO3/NaH2PO4 at 441.5/18.1 μM (low) 883/36.3 μM (medium) and 1766/72.6 μM (high). Both nutrient and irradiance had a significant effect (p < 0.05) on cellular abundance during the period of culture, except for the fourth and seventh day for nutrients (p > 0.05). In cultures under low nutrient condition, NO- and PO4- were almost depleted by the fifth day and in cultures with medium nutrient this condition occurred in the sixth day; whereas, at high nutrient condition the nutrients were not depleted. We concluded that A. carteri had higher growth rates and nutrient consumption at 300 μmol quanta m-2 s-1 during the first five days and in general the effect of nutrients on the pigment ratios was not significant (p > 0.05). However, the average peridinin/Chla ratio decreased up to 72% from the lowest and the highest irradiance. The opposite was observed for the average of diadinoxanthin/Chla ratio that increased almost two-fold, and the averages dinoxanthin and diatoxanthin to Chla ratios that increased from low to high irradiances. The average diatoxanthin/Chla ratio at 750 μmol quanta m-2 s-1 increased up to 2.7-fold from the exponential to the stationary phase only in the low and medium nutrient concentration. Likewise, the average peridinin, dinoxanthin and diatoxanthin to Chla ratios were not significantly different at 50 and 150 μmol quanta m-2 s-1. These results indicate important changes in average carotenoids/Chla ratios in A. carteri cultured under different irradiances. Se evaluaron el crecimiento poblacional, consumo de macronutrientes (,) y proporción de carotenoides/clorofila a en Amphidinium carteri Hulburt, cultivado durante 7 días, bajo condiciones de luz continua: 50, 150, 300 y 750 μmol quanta m-2 s-1 y tres concentraciones de nutrientes NaNO3/NaH2PO4 (441.5/18.1 μM (bajo); 883/36.3 μM (medio) y 1766/72.6 μM (alto). La abundancia celular fue significativamente afectada (p < 0.05) tanto por el nivel de nutrientes como por la irradianza durante el periodo de cultivo, excepto para el nivel de nutriente en el cuarto y séptimo día. En los cultivos con bajo nutriente, el se agotaron casi totalmente al quinto día, y en cultivos con medio nutriente ocurrió al sexto día; mientras que en alta concentración de nutrientes, éstos no se agotaron. Se concluye que A. carteri tuvo la mayor tasa de crecimiento y
Variability in the Light Absorption Coefficient by Phytoplankton, Non-Algal Particles and Colored Dissolved Organic Matter in the Northern Gulf of California  [PDF]
Stella P. Betancur-Turizo, Adriana G. González-Silvera, Eduardo Santamaría-Delngel, Roberto Millán-Nú?ez, Eduardo Millán-Nú?ez, Héctor García-Nava, Víctor M. Godínez, Laura Sánchez-Velasco
Open Journal of Marine Science (OJMS) , 2017, DOI: 10.4236/ojms.2018.81002
Abstract:
Variability of the optical properties of the northern Gulf of California (México) were analyzed for the first time based on six cruises performed from spring to summer (March to September) between 2008 and 2013. The changes observed in the absorption by three seawater components (phytoplankton, detritus and chromophoric dissolved organic matter or CDOM) were analyzed in relation to changes in bio-optical regions and composition of the phytoplankton community (determined based on phytoplankton pigments). Two regions with unique bio-optical characteristics were identified separated by a narrow transition zone: the Upper Gulf of California (UGC) and Northern Gulf of California (NGC). Despite the temporal changes in their spatial distribution they maintained particular characteristic. UGC is characterized by an average Chla of 1.78 mg/m3, the dominance of microphytoplankton (diatoms and dinoflagellates) and a stronger contribution of detritus to total light absorption. NGC is characterized by an average Chla of 0.7 mg/m3 and the predominance of picophytoplankton, characterized by the dominance of zeaxanthin (marker pigment for cyanobacteria) and/or chlorophyll b (marker pigment for green algae), along with a co-dominium by CDOM and phytoplankton to light absorption. Results indicate that Case II waters can be very different when evaluating the individual contribution by phytoplankton, detritus and CDOM to total light absorption what has to be considered for the selection of bio-optical models for each specific region what can also help to a better definition of the related uncertainties.
Does It Pay to Be “Greener” than Legislation? An Empirical Study of Spanish Tile Industry
Conrado Carrascosa-López,María-del-Val Segarra-O?a,ángel Peiró-Signes,Baldomero Segura-García-del-Río
Journal of Sustainable Development , 2012, DOI: 10.5539/jsd.v5n5p17
Abstract: Environmental awareness is a key aspect considered in companies’ corporate social responsibility. Companies try always to comply with current environmental legislation. Does it make sense for them to go beyond legislation? This work’s aim is to answer this question and to study how companies can generate value through environmental proactivity. This study is focused on the Spanish tile industry sector. This research’s objective is to describe which aspects form companies’ environmental strategy; barriers and facilitators that make possible proactive environmental orientation; benefits companies can obtain from it and obstacles companies face when trying to be environmentally proactive, through a case study as qualitative methodology. The major benefit observed is to prevent sanctions, followed by improvement of corporate image, long-term cost savings and new business opportunities obtaining. Main obstacles companies face are lack of institutional and financial support. Evidence is found that environmental proactivity is considered in companies’ strategic planning.
Late Thrombolysis in Massive Pulmonary Thromboembolism  [PDF]
Rodrigo Molina Mendoza, Daniel Arnal, Santiago García-del-Valle
Open Journal of Anesthesiology (OJAnes) , 2012, DOI: 10.4236/ojanes.2012.25055
Abstract: Pulmonary thromboembolism (PTE) remains a diagnostic and therapeutic challenge for physicians. Anticoagulation with heparin remains as the cornerstone in its management, reserving thrombolysis for cases with hemodynamic impairment. The later has been associated with haemorrhagic complications and has proved beneficial when initiated within the first 48 hours of PTE; but there is little evidence supporting its use passed this time. We present a case of an 84 year old female admitted in our unit and treated successfully with thrombolysis for massive PTE at the fifth day of diagnosis. The patient improved towards complete recovery and was discharged from the hospital 22 days after admission without complications.
DE ESPERAS Y ESPERANZAS: ASPECTOS PSICOSOCIALES EN PROCESOS DE JUSTICIA TRANSICIONAL
García-del Soto,Araceli Arancha; Barbera,Rosemary;
International Law , 2010,
Abstract: this paper is a product of the inter- and transcultural applied work in the field of gender-based violence (it reats particularly cases of women who have been sexually violated in a systematic manner) and the reflection of both authors when working with victims of sociopolitical violence and human rights abuses. it makes particular emphasis en examining how people from different professional backgrounds center their work differently, sometimes with a focus that falls far from the needs of the survivors themselves. our main goal is to illustrate the different disciplinary approaches of law and psychosocial accompaniment in the processes in which the victims/survivors engage, as part of their search for justice, and the impacts these different lenses and timings might have on women themselves. the methodology is an interdisciplinary reflection (psychology, social work, humanitarian action and sociology) based on field work done with a group of women who survived sexual abuses in the northern coast of colombia (but it also considers some cross-cultural comparisons with other cases of gender-based violence). this experience aims at examining and elaborating on the individual and collective damage of the various cases of women who were abused. this was accomplished through individual interviews, focus groups, ethnographic data recollection, and team-work with the lawyers in charge of the case. our final conclusion highlights the need to improve the coordination between the various professionals and professional disciplines dealing with the cases, by listening better and becoming more aware of the genuine needs of the survivors/victims as they expressed them.
Hijacking of eukaryotic functions by intracellular bacterial pathogens
Alonso,Ana; García-del Portillo,Francisco;
International Microbiology , 2004,
Abstract: intracellular bacterial pathogens have evolved as a group of microorganisms endowed with weapons to hijack many biological processes of eukaryotic cells. this review discusses how these pathogens perturb diverse host cell functions, such as cytoskeleton dynamics and organelle vesicular trafficking. alteration of the cytoskeleton is discussed in the context of the bacterial entry process (invasion), which occurs either by activation of membrane-located host receptors ("zipper" mechanism) or by injection of bacterial proteins into the host cell cytosol ("trigger" mechanism). in addition, the two major types of intracellular lifestyles, cytosolic versus intravacuolar (phagosomal), which are the consequence of alterations in the phagosome-lysosome maturation route, are compared. specific examples illustrating known mechanisms of mimicry or hijacking of the host target are provided. finally, recent advances in phagosome proteomics and genome expression in intracellular bacteria are described. these new technologies are yielding valuable clues as to how these specialized bacterial pathogens manipulate the mammalian host cell.
The Listeria Small RNA Rli27 Regulates a Cell Wall Protein inside Eukaryotic Cells by Targeting a Long 5′-UTR Variant
Juan J. Quereda,álvaro D. Ortega,M. Graciela Pucciarelli ,Francisco García-del Portillo
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004765
Abstract: Listeria monocytogenes is a bacterial pathogen whose genome encodes many cell wall proteins that bind covalently to peptidoglycan. Some members of this protein family have a key role in virulence, and recent studies show that some of these, such as Lmo0514, are upregulated in bacteria that colonize eukaryotic cells. The regulatory mechanisms that lead to these changes in cell wall proteins remain poorly characterized. Here we studied the regulation responsible for increased Lmo0514 protein levels in intracellular bacteria. The amount of this protein increased markedly in intracellular bacteria (>200-fold), which greatly exceeded the increase in lmo0514 transcript levels (~6-fold). Rapid amplification of 5′-cDNA ends (RACE) assays identified two lmo0514 transcripts with 5′-untranslated regions (5′-UTR) of 28 and 234 nucleotides. The transcript containing the long 5′-UTR is upregulated by intracellular bacteria. The 234-nucleotide 5′-UTR is also the target of a small RNA (sRNA) denoted Rli27, which we identified by bioinformatics analysis as having extensive base pairing potential with the long 5′-UTR. The interaction is predicted to increase accessibility of the Shine-Dalgarno sequence occluded in the long 5′-UTR and thus to promote Lmo0514 protein production inside the eukaryotic cell. Real-time quantitative PCR showed that Rli27 is upregulated in intracellular bacteria. In vivo experiments indicated a decrease in Lmo0514 protein levels in intracellular bacteria that lacked Rli27. Wild-type Lmo0514 levels were restored by expressing the wild-type Rli27 molecule but not a mutated version unable to interact with the lmo0514 long 5′-UTR. These findings emphasize how 5′-UTR length affects regulation by defined sRNA. In addition, they demonstrate how alterations in the relative abundance of two transcripts with distinct 5′-UTR confine the action of an sRNA for a specific target to bacteria that occupy the intracellular eukaryotic niche.
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