Papers by DR. BENJAMIN CHAVARRIA LOPEZ
Construcción de ciudadanos Este ensayo arbitra una disputa sobre los sentidos en el que los ciuda... more Construcción de ciudadanos Este ensayo arbitra una disputa sobre los sentidos en el que los ciudadanos son '' construidos.'' El punto de vista liberal-democrático Teoría de ciudadanía como un estatuto jurídico que garantiza la igualdad política. Tal modo ignora el
Connected Resources are a family of combinable devices that add digital capabilities to mundane o... more Connected Resources are a family of combinable devices that add digital capabilities to mundane objects, in order to support everyday strategies of resourcefulness in older people. Using Connected Resources as an example, this paper describes de- signing for older people's resourcefulness using an RtD process. Here, the artifact dimensions of openness, which is needed when designing for resourcefulness, are generated through an experimental study with prototypes. The dimensions of a variety of use were identified during a participatory session in which uses for prototypes in the everyday practices of older people were explored. Finally, design considerations to ensure older people's different levels of independence from technology were determined. The paper first describes three working prototypes built during the first design iteration. It then moves on to showcase two studies conducted with these prototypes and the insights in relation to the variables of openness and vari...
Clinical Chemistry and Laboratory Medicine (CCLM), 2018
Background: Immunoglobulin G (IgG) and IgG subclass assays are indicated in patients with suspect... more Background: Immunoglobulin G (IgG) and IgG subclass assays are indicated in patients with suspected primary immunodeficiency (PID). Commercially available assays for IgG subclass determination are calibrated against various preparations, and so specific reference values are required for each of them. Using Optilite® reagents from The Binding Site Group Ltd., we sought to determine the pediatric IgG and IgG subclass reference intervals with respect to the ERM-DA470k certified reference material. Methods: Levels of IgG and IgG subclasses were analyzed in serum samples collected from a large cohort of PID-free children and adolescents. Reference intervals were calculated for previously published age groups (6–12 months, 12–18 months, 18 months–2 years, 2–3 years, 3–4 years, 4–6 years, 6–9 years, 9–12 years and 12–18 years), according to the Clinical and Laboratory Standards Institute’s C28-A3c protocol. Results: A total of 456 serum samples were analyzed. The correlation between the to...
Clinica Chimica Acta, 2019
The within series CV% was bigger for low concentrations PSA (pb0.05) for samples extracted by dis... more The within series CV% was bigger for low concentrations PSA (pb0.05) for samples extracted by distillated water compared with deionized (7.8% and 4.0% respectively). Between-series variation was bigger for both levels of concentrations in samples extracted by distillated water (pb0.05): 28.3% and 13.2% for low and 15.2% and 6.7% for high concentrations respectively. Activity of total PSA were significantly decreased (pb0.05) in samples extracted by distillated water compared with deionized for low concentrations of PSA: 64.9% and 81.2% after 3 hours and 51.6% and 71.6% after 6 hours respectively. Conclusions Samples of semen on dry spots for testing of total PSA extracted with deionized water at room temperature (+18-20°C) are more stable compared with distillated water and could be stored up to 4 hour 30 minutes during working day while PSA extracts with distillated water could be stored no more than 1 hour 30 minutes. Thus implementation of deionized water for PSA extracts from semen on dry spots improves the quality of preanalytical phase.
Research in Dance Education, 2019
The purpose of this dissertation was to investigate the lived experiences of community college da... more The purpose of this dissertation was to investigate the lived experiences of community college dance students. Previous research was examined to provide a more holistic picture of dancers during their college years and while in the workforce. The literature reviewed indicated that the emergence of dance as a field of study was controversial. Its beginnings were marked by debates concerning (a) the very definition of dance as a body of motion and a body of knowledge that includes a history and a philosophy as asserted by Dimondstein (1985), (b) its legitimate place within the academy (the perception that university dance programs were vocational in nature with little academic value) as noted by Stinson (1990); and, more recently (c) the possibility of some resolution to make dance not only a performing art but an academic discipline in its own right (Savrami, 2012). The theoretical framework of social cognitive career theory was used but was modified to include only the tenets most frequently cited in the literature that directly influenced the career identity of dancers particularly in relation to their motivation to academically persist and graduate. The phenomenological analysis, in the tradition of Moustakas (1994) and Wertz (2005), produced an early thematic matrix of 18 codes that were reduced to six major themes: aspirations, academic commitment, emotional identification, anticipated outcome or career expectation, vicarious learning, and challenges. One of the major recommendations included conducting a longitudinal study focusing on how students navigate an unpredictable job market, including the discussion of issues of workforce preparation in the academic curriculum and major. iv ACKNOWLEDGMENTS First and foremost, I would like to thank God for guiding me through my long educational journey. This dissertation was the result of hard work and valuable assistance from others. I am very grateful to my committee chair, Dr. Rosa Cintrón, for being so committed to my success. I would also like to acknowledge my parents, family and friends for their support during the difficult times of this process. In addition, I would like to thank the chair of the dance department for assisting me in finding participants for my study. I would also like to recognize my participants for giving their time to participate in my study. To my fellow doctoral cohort, thank you for your assistance and guidance. Finally, I would like to thank my dissertation committee members for their efforts in helping me produce the final product of this study. v TABLE OF CONTENTS LIST OF FIGURES .
Environmental Research Letters, 2018
There is growing concern globally about the occurrence of anthropogenic organic contaminants in t... more There is growing concern globally about the occurrence of anthropogenic organic contaminants in the environment, including pharmaceuticals and personal care products. This concern extends to groundwater, which is a critical water resource in Europe, and its protection is a priority to the European Commission, the European Union (EU) Member States and national agencies across Europe. Maintaining good groundwater status supports improved public health, economic growth and sustains groundwater dependant ecosystems. A range of measures have been introduced for regulating several substances that have impacted groundwater (e.g. nitrate and pesticides). However, these measures only cover a small fraction of anthropogenic substances that could pollute groundwater. Monitoring for these unregulated substances is currently very limited or not carried out at all. Therefore, a coordinated European-wide approach is needed to identify, monitor and characterise priority substances or groups of substances that have the potential to pollute groundwater. This evidence base is critical for policy development and controls on these currently unregulated substances. The European Commission highlighted this as a need during the review of the EU Groundwater Directive Annexes in 2014, when the requirement to develop a Groundwater Watch List (GWWL) was established. This paper describes the approach that has been developed through a voluntary initiative as part of the EU CIS Working Group Groundwater to establish the voluntary EU GWWL. The process for developing the GWWL is one that has brought together researchers, regulators and industry, and is described here for the first time. A summary of the key principles behind the methodology is presented as well as results from pilot studies using per-and polyfluoroalkyl substances and pharmaceuticals. These explore and support the viability of the GWWL process, an important step towards its adoption and its future use for groundwater protection across Europe.
Frontiers in immunology, 2017
An overall response assay [OVA, based on a 23-valent pneumococcal polysaccharide vaccine (PPV23)]... more An overall response assay [OVA, based on a 23-valent pneumococcal polysaccharide vaccine (PPV23)] is widely used to screen for anti-pneumococcal antibodies. Given the heterogeneity of response from one polysaccharide (PS) to another, a World Health Organization-standardized serotype-specific enzyme-linked immunosorbent assay (SSA) is considered to be the only reliable method for testing anti-PS antibody responses in individuals with suspected primary immunodeficiencies (PIDs). To evaluate the OVA relative to the reference SSA. Serum samples of adult patients referred for a suspected PID were collected before and then 4-8 weeks after immunization with PPV23. The anti-pneumococcal response was systematically assessed with an SSA (7-16 serotypes) and interpreted according to the American Academy of Asthma, Allergy and Immunology's current guidelines. We used receiver operating characteristic curves and agreement indices to assess the OVA's diagnostic value in a first cohort. In...
American journal of physiology. Lung cellular and molecular physiology, Jan 24, 2017
We previously proposed a role for the 2-pore domain potassium (K2P) channel TREK-1 in hyperoxia (... more We previously proposed a role for the 2-pore domain potassium (K2P) channel TREK-1 in hyperoxia (HO)-induced lung injury. To determine whether redundancy between the 3 TREK isoforms (TREK-1, TREK-2, TRAAK) could protect from HO-induced injury, we now examined the effect of deletion of all 3 TREK isoforms in a clinically relevant scenario of prolonged HO exposure and mechanical ventilation (MV). We exposed WT and TREK-1/TREK-2/TRAAK-deficient (triple ko) mice to either room air, 72 hours HO, MV (high and low tidal volume), or a combination of HO+MV, and measured quasi-static lung compliance, BAL protein concentration, histologic lung injury scores (LIS), cellular apoptosis, and cytokine levels. We determined surfactant gene and protein expression, and attempted to prevent HO-induced lung injury by prophylactically administering exogenous surfactant (Curosurf). HO treatment increased lung injury in triple ko but not WT mice, including an elevated LIS, BAL protein concentration, marker...
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2017
We report on 11 cases of specific polysaccharide antibody deficiency (SPAD) revealed in adulthood... more We report on 11 cases of specific polysaccharide antibody deficiency (SPAD) revealed in adulthood by severe infections with encapsulated bacteria. Given that immunoglobulin replacement therapy can effectively prevent the recurrence of bacterial infections in this context, SPAD should be considered once other antibody deficiencies have been ruled out.
Journal of Vascular Surgery, 2016
Background: Endovascular repair of aortic aneurysms involving the visceral segment of the aorta o... more Background: Endovascular repair of aortic aneurysms involving the visceral segment of the aorta often requires placement of a covered bridging stent in the celiac axis (CA). The median arcuate ligament (MAL) is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament may compress and distort the celiac artery and result in difficult cannulation, or stenosis and occlusion of the vessel. This study evaluated the influence of the MAL compression on the technical success and the patency of the celiac artery after branched and fenestrated endovascular aortic repair. Methods: We retrospectively analyzed a cohort of consecutive patients treated electively for complex aneurysms with branched and fenestrated endovascular aortic repair between January 2007 and April 2014. All data were collected prospectively. Analysis of preoperative computed tomography angiography on a three-dimensional workstation determined the presence of MAL compression. Patency of the CA bridging stent was assessed during follow-up by computed tomography angiography and duplex ultrasound evaluation. Statistical analysis was performed to compare the outcomes of patients with MAL (MALþ) and without MAL (MAL-) compression. Results: Of 315 patients treated for aortic disease involving the visceral segment during the study period, 113 had endografts designed with a branch (n ¼ 57) or fenestration (n ¼ 56) for the CA. In 45 patients (39.8%), asymptomatic compression of the CA by the MAL was depicted (MALþ). Complex endovascular techniques were required in this group to access the CA in 16 (14.2%) patients (vs none in the MAL-group; P ¼ .003), which lead to a failed bridging stent implantation in seven patients (6.2%). Increased operative time and dose area product were observed in the MALþ group, but this did not reach statistical significance. In the MALþ group, no thrombosis of the CA bridging stents were observed during follow-up; an external compression of the CA bridging stent was depicted in six patients but without hemodynamic effect on duplex ultrasound imaging. In the MAL-group, one CA bridging stent occlusion occurred owing to an embolus from a cardiac source. Conclusions: MAL compression is associated with good celiac trunk bridging stent patency during follow-up, but with a higher rate of technical difficulties and failed bridging stent implantation during the procedure.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
EB1 is an important microtubule associating protein (MAP) that acts as a master coordinator of pr... more EB1 is an important microtubule associating protein (MAP) that acts as a master coordinator of protein activity at the growing plus-end of the microtubule. We can recapitulate the plus-end binding behavior of EB1 along the entire length of a static microtubule using microtubules polymerized in the presence of the nonhydrolyzable GTP analogs GMPCPP and GTPγS instead of GTP. Through the use of single-molecule TIRF imaging we find that EB1 is highly dynamic (with a sub-second characteristic binding lifetime) and continuously diffusive while bound to the microtubule. We measure the diffusion coefficient, D, through linear fitting to mean-squared displacement of individually labeled proteins, and the binding lifetime, τ , by fitting a single exponential decay to the probability distribution of trajectory lifetimes. In agreement with measurements of other diffusive MAPs, we find that D increases and τ decreases with increasing ionic strength. We also find that D is sensitive to the choice of GTP analog: EB1 proteins bound to GTPγS polymerized microtubules have a D half of that found with GMPCPP polymerized microtubules. To compare these single-molecule measurements to the bulk binding behavior of EB1, we use TIRF imaging to measure the intensity of microtubules coated with EB1-GFP as a function of EB1 concentration. We find that EB1 binding is cooperative and both the quantity of EB1 bound and the dissociation constant are sensitive to GTP analog and ionic concentration. The correlation between binding affinity and D and the cooperative nature of EB1-microtubule binding leads to a decrease in D with increasing EB1 concentration. Interestingly, we also find an increase in τ at high EB1 concentrations, consistent with attractive EB1-microtubule interactions driving the cooperativity. To further understand the nature of the cooperativity we estimate the interaction energy by measuring the association and dissociation rates (k on and k off respectively) at different concentrations of EB1.
Cytoskeleton, 2014
Using the nonhydrolyzable GTP analog GMPCPP and the slowly hydrolyzable GTPgS, we polymerize micr... more Using the nonhydrolyzable GTP analog GMPCPP and the slowly hydrolyzable GTPgS, we polymerize microtubules that recapitulate the end binding behavior of the plus end interacting protein (1TIP) EB1 along their entire length, and use these to investigate the impact of EB1 binding on microtubule mechanics. To measure the stiffness of single filaments, we use a spectral analysis method to determine the ensemble of shapes adopted by a freely diffusing, fluorescently labeled microtubule. We find that the presence of EB1 can stiffen microtubules in a manner that depends on the hydrolysis state of the tubulin-bound nucleotide, as well as the presence of the small-molecule stabilizer paclitaxel. We find that the magnitude of the EB1-induced stiffening is not proportional to the EB1-microtubule binding affinity, suggesting that the stiffening effect does not arise purely from an increase in the total amount of bound EB1. Additionally, we find that EB1 binds cooperatively to microtubules in manner that depends on tubulin-bound nucleotide state. V
International Journal of Interactive Multimedia and Artificial Intelligence, 2013
Nowadays, business models are in permanent evolution since the requirements belongs to a rapidly ... more Nowadays, business models are in permanent evolution since the requirements belongs to a rapidly evolving world. In a context where communications all around the world travel so fast the business models need to be adapted permanently to the information the managers receive. In such world, traditional software development, needed for adapting software to changes, do not work properly since business changes need to be in exploitation in shorter times. In that situation, it is needed to go quicker from the business idea to the exploitation environment. This issue can be solved accelerating the development speed: from the expert to the customer, with no-or few, technical intervention. This paper proposes an approach to empower domain experts in developing adaptability solutions by using automated sets of production rules in a friendly way. Furthermore, a use case that implements this kind of development was used in a real problem prototype.
Iberian Journal of Information Systems and Technologies, 2012
Resumen: Debido a la complejidad que reviste el dominio de la Administración Electrónica (AE), la... more Resumen: Debido a la complejidad que reviste el dominio de la Administración Electrónica (AE), las desarrolladas deberán ser capaces de integrarse con la multitud de plataformas y sistemas que componen dicho dominio. El impacto de esta integración además mejorar la tramitación de procedimientos. En el presente trabajo se propone un lenguaje de modelado gráfico (DSL) para la tramitación de procedimientos en el dominio específico de la AE. Este lenguaje parte de la definición de un metamodelo de AE que identifica sus principales entidades y define sus relaciones. Además se construyó una herramienta gráfica de modelado la cual fue probada con dos casos de estudio reales. aplicaciones
Lecture Notes in Computer Science, 2003
This paper presents the evaluation of a group of methods and tools for the measurement of usabili... more This paper presents the evaluation of a group of methods and tools for the measurement of usability in software products and software artefacts in the web. The evaluation carried out consists on studying the measurement principles and dimensions considered for each one of the methods and tools, with the purpose of comparing the degree of vicinity among them and with the principles enumerated by the ISO 9241-11 standard: efficiency, effectiveness and satisfaction.
Uploads
Papers by DR. BENJAMIN CHAVARRIA LOPEZ