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Search Results: 1 - 10 of 14556 matches for " Rafael Fernandez "
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ICU cornerstone: 'triggering effort'
Rafael Fernandez
Critical Care , 2002, DOI: 10.1186/cc1875
Abstract: The most frequent reason for admission to an intensive care unit is need for ventilatory assistance. At least, this is my experience over the past 20 years from working in university and county hospitals. Regardless of the illness that provokes respiratory insufficiency, the majority of patients with respiratory failure eventually require mechanical ventilation. If there is an improvement in oxygenation after a few days, then we are forced to consider reducing the intensity of ventilatory support. In the early years of my critical care training, when we checked ventilated patients under the effects of low-level sedation and were attempting to wean them off ventilation, such patients normally had to make an effort to trigger the ventilator. At that time, our teachers told us that this was normal; 'it is a kind of exercise training' said one, and 'it is our way of finding out which patients can work harder' said another. It was not clear why the 'trigger knob' had always to be in the standard position (not too difficult or too easy). One of my mentors told me to take advantage of the triggering effort because he thought that this effort could be related to a sophisticated parameter used in respiratory physiology, namely the occlusion pressure, or P0.1. After that, I started conducting research by obtaining many recordings of airflow and airway pressure in intubated, ventilated patients while they attempted to breathe. My mentor was right, and we published some stimulating papers about the 'triggering effort' [1].Nevertheless, patients continued having to work to breathe while they were on the ventilator. When I reviewed our experimental tracings, I realized that patient response was not so predictable. Each patient had his or her own pattern of response, and most of them started inspiration before finishing expiration. At that time, not much was known about this type of patient response. We looked at these results again and made new tracings in different patients. Amo
Public Project Portfolio Optimization under a Participatory Paradigm
Eduardo Fernandez,Rafael Olmedo
Applied Computational Intelligence and Soft Computing , 2013, DOI: 10.1155/2013/891781
Abstract:
Public Project Portfolio Optimization under a Participatory Paradigm
Eduardo Fernandez,Rafael Olmedo
Applied Computational Intelligence and Soft Computing , 2013, DOI: 10.1155/2013/891781
Abstract: A new democracy paradigm is emerging through participatory budgeting exercises, which can be defined as a public space in which the government and the society agree on how to adapt the priorities of the citizenship to the public policy agenda. Although these priorities have been identified and they are likely to be reflected in a ranking of public policy actions, there is still a challenge of solving a portfolio problem of public projects that should implement the agreed agenda. This work proposes two procedures for optimizing the portfolio of public actions with the information stemming from the citizen participatory exercise. The selection of the method depends on the information about preferences collected from the participatory group. When the information is sufficient, the method behaves as an instrument of legitimate democracy. The proposal performs very well in solving two real-size examples. 1. Introduction Even in the best scenarios, designing public policies is far from being an exact science, with quantitative determinations beyond all subjectivity. Without denying the objective content of the social interest, it is certain that the difficulty in apprehending it opens space to methods that seek to model the preferences of concrete individuals, able to express their preferences in a more or less consistent way. Up to now, democracy in the distribution of public resources has been fundamentally expressed in(i)the action of groups empowered by the society to make budget decisions on its behalf (GESBD) (parliaments, communes, governing boards of public organizations), formed by members of the political class legitimized by the popular vote, but that respond to their personal and their party’s interests instead of to the will of the electorate,(ii)the action of GESBDs formed by officials and experts appointed by the executive power that rather than interests of the electorate, reflected only in a very indirect way, reflect policies already designed by the executive. (iii)the attempts of participatory budgeting carried out at local level where the population’s priorities are directly heard by constituted authorities and are later reflected in the distribution of resources once the compatibility with the opinions of the political class has been achieved. Since its emergence in Porto Alegre, Brazil, participatory budgeting has spread to hundreds of Latin American cities and dozens of cities in other continents. “Participatory budgeting” can be defined as a public space in which the government and the society agree how to adapt the priorities of the
Green Areas and Microscale Thermal Comfort in Arid Environments: A Case Study in Mendoza, Argentina  [PDF]
Salvador Enrique Puliafito, Fabián Rolando Bochaca, David Gabriel Allende, Rafael Fernandez
Atmospheric and Climate Sciences (ACS) , 2013, DOI: 10.4236/acs.2013.33039
Abstract:

A series of mobile and stationary meteorological measurements were performed in the city of Mendoza, Argentina to study the local influence of green areas on the urban canopy layer heat island effect at the micro scale, during the Austral summer of 2003-2005. These results were associated in representative local climate zones (LCZ), which helped to identify different thermal conditions within the city. The physiologically equivalent temperature index was used to determine the thermal comfort in each LCZ, showing that during daylight, trees and parks improve thermal comfort through shading and evapotranspiration; but at the same time, urban tree corridors delay night cooling by retaining warm air beneath their canopies. Also irrigation showed to positively influence on the extension and intensity of the cooling effect of rural areas and parks. The cooling influence of an urban park spreads out through the neighborhoods for 800 - 1000 m, with an average temperature decrease of 1.3°C during daytime and >4.0°C at nighttime.

Aproximación de los problemas de optimización por redes neuronales artificiales
Ruiz Sepúlveda, Amparo,Caballero Fernandez, Rafael
Rect@ , 2001,
Abstract: En el presente artículo, pretendemos aportar un conocimiento de cómo puede aproximarse un problema de optimización mediante la dinámica de las redes neuronales artificiales, específicamente mediante las redes de tipo Hopfield. La elección de este tipo de redes radica en el objetivo que nos hemos propuesto en el presente trabajo, la resolución on-line de los problemas de optimización lineal, cuadrática, no lineal y combinatoria. Construimos, desarrollamos y justificamos formalmente una metodología integral que permite recoger los distintos tipos de problemas de optimización y construir una red neuronal de tipo Hopfield que los resuelva de una manera computacionalmente adecuada y formalmente correcta, comparando los resultados obtenidos con los publicados más recientemente.
Voyage of RepA protein from plasmid DNA replication through amyloid aggregation towards synthetic biology
Rafael Giraldo,Maria Elena Fernandez-Tresguerres
Journal of Applied Biomedicine , 2010,
Abstract: DNA replication of plasmids in Gram-negative bacteria has been an object of study at CIB-CSIC for nearly30 years. We have been focused on the enterobacterial antibiotic resistance factor R1 (1981–1992) and thepPS10 replicon from the phytopathogen Pseudomonas savastanoi (since 1984). Our group has usedmultidisciplinary (genetic, biochemical and biophysical-structural) approaches to unravel the molecularmechanism for the activation of RepA. Rep-type plasmidic proteins are either transcriptional repressors orreplication initiators/inhibitors, depending on their association state (dimers vs. monomers) and targeting ofalternative (operator or iteron) DNA sites. We discovered that allosteric DNA-binding remodels the structureof RepA N-terminal domain (WH1), transforming α-helical portions into β-strands. This precisely tunes thedistances between the DNA reading heads in WH1 and the C-terminal domain (WH2), to match the targetoperator or iteron sequences. We have recently moved into engineering such structural transformation inRepA-WH1 to build-up synthetic protein devices that allow for customized ligand (DNA)-promotedamyloidogenesis. Our basic studies on plasmid DNA replication are relevant for settling the bases of aminimalist bacterial model to tackle transmissible amyloid proteinopathies and are a valuable tool forbottom-up synthetic biology.
Cued aversive classical conditioning in humans: The role of trait-anxiety  [PDF]
óscar Andión, Xavier Caseras, Miquel àngel Fullana, Alberto Fernandez-Teruel, Marc Ferrer, Miquel Casas, Rafael Torrubia
Open Journal of Psychiatry (OJPsych) , 2013, DOI: 10.4236/ojpsych.2013.32021
Abstract:

No study so far has specifically addressed the influence of individual differences in trait-anxiety on aversive classical conditioning as indexed by the startle reflex response. We compared the startle reflex responses between participants classified as high (n = 25) and low (n = 26) in trait-anxiety while undergoing a single-cue aversive classical conditioning procedure. High trait-anxiety group showed a greater startle response to the CS relative to the ITI at the post-acquisition compared with the pre-acquisition phase. Low trait-anxiety group did not show such a clear pattern of conditioning, and results from this group seem to be concealed by differences in the startle responses to the CS and the ITI during the pre-acquisition phase. However, a post-hoc analysis in which such differences at pre-conditioning were removed showed no conditioning effects in low trait-anxiety participants. Taking together, these results suggest differences between high and low trait-anxiety groups in the acquisition of the CS-US association. However, further research should clarify the unexpected pattern of responses shown by low trait-anxiety group.

A modified McCabe score for stratification of patients after intensive care unit discharge: the Sabadell score
Rafael Fernandez, Francisco Baigorri, Gema Navarro, Antonio Artigas
Critical Care , 2006, DOI: 10.1186/cc5136
Abstract: A prospective cohort study was performed in the general ICU of a university-affiliated hospital. In 2003 and 2004 we prospectively recorded the attending intensivist's subjective prognosis at ICU discharge about the hospital outcome for each patient admitted to the ICU (the Sabadell score), which was later compared with the real hospital outcome.We studied 1,521 patients with a mean age of 60.2 ± 17.8 years. The median (25–75% percentile) ICU stay was five (three to nine) days. The ICU mortality was 23.8%, with 1,156 patients being discharged to the ward. Post-ICU ward mortality was 9.6%, mainly observed in patients with a Sabadell score of 3 (81.3%) or a score of 2 (41.1%), whereas lower mortality was observed in patients scoring 1 (17.2%) and scoring 0 (1.7%). Multivariate analysis selected age and the Sabadell score as the only variables associated with ward mortality, with an area under the receiver operating curve of 0.88 (95% CI 0.84–0.93) for the Sabadell score.The Sabadell score at ICU discharge works effectively to stratify patients according to hospital outcome.Mortality in the ward after intensive care unit (ICU) discharge is considered a quality parameter, and is commonly defined as a source of unexpected or avoidable mortality. Mortality has been reported to range from 6% to 27% [1] and can be related to factors occurring before or after the ICU stay. A worse outcome is associated with the physiological reserve before ICU admission [2], the type of illness, the intensity of care required, and the clinical stability and/or the grade of nursing dependence at discharge [3,4]. These data suggest that keeping at-risk patients in the ICU for a further 48 hours might reduce mortality after ICU discharge by 39% [5]. Accordingly, step-down units may reduce post-ICU mortality by avoiding inappropriate early discharges from the ICU [6]. It is also yet to be determined whether outreach teams have a favourable impact on the ward mortality rate in this specific popul
Viability in protoplasts and cell suspensions of Coffea arabica cv. Catimor
Fernandez-Da Silva,Rafael; Menéndez-Yuffá,Andrea;
Electronic Journal of Biotechnology , 2006,
Abstract: two methods were evaluated in order to assess the viability of protoplasts and cell suspensions of coffea arabica cv. catimor used in a protocol of transformation by electroporation. one method consisted of staining with 1 % evans blue and the other staining with 1% 3-[4,5-dimethyltiazol-2-yl]-2,5-diphenyltetrazolium bromide (mtt). when evans blue was applied to viable cells and protoplasts they either did not stain or acquired a faint blue colour. however, it was difficult to distinguish the non-viable cells in the wide spectrum of clear blue tonalities. in contrast, with the mtt assay only the viable cells and protoplasts reduced this salt to the red coloured formazan; viable and non-viable cells were distinguished more clearly with mtt than with evans blue. the optimal temperature for the reaction with mtt was 37oc. the time of incubation was shown to be important, since longer times improved the reaction; the highest viability value was obtained after incubation for 120 min.
Transient gene expression in secondary somatic embryos from coffee tissues electroporated with the genes gus and bar
Da Silva,Rafael Fernandez; Menéndez-Yuffá,Andrea;
Electronic Journal of Biotechnology , 2003,
Abstract: different electroporation conditions were evaluated, toward the goal of transformation of coffea arabica cv. catimor. the tissues assayed were: embryogenic calli, leaf sections from in vitro plants, and somatic embryos in globular and torpedo stage obtained from cell suspensions. the effect of 1 or 24-hour pretreatment with an enzymatic solution (2% cellulase, 1% macerozyme) and electric field strength (375, 625, 875 v/cm) was evaluated. in all the experiments the tissues were incubated in asp buffer (potassium aspartate) during three hours, and then one hour with plasmid dna (pcambia3201, containing gus and bar genes) at room temperature. the electroporation was performed at a capacitance of 900 μf. the effect of the parameters evaluated was determined by the transient expression of the gus gene. the optimal conditions for electroporation were one hour of enzymatic pretreatment of torpedo shape embryos, electroporation at 375 v and 900 μf. the culture of electroporated tissues in liquid media with 8 mg/l benzyladenine conducted to maximal regeneration through secondary somatic embryogenesis. the secondary somatic embryos were formed directly in the hypocotyl surface of the electroporated torpedo shape primary somatic embryos, the production of secondary somatic embryos was significantly greater than the production of primary embryos, therefore, this is an excellent method to propagate the products of genetic transformation. the secondary somatic embryos regenerated from electroporated torpedo shape somatic embryos were positive for gus expression, and also in the pcr analysis for the genes gus and bar.
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