5,469 research outputs found
Recommended from our members
Ambient combustion by-product exposures and exhaled biomarkers of airway inflammation and oxidative stress
Introduction: Numerous studies have found associations between exposure to airborne particulate matter and respiratory morbidity and mortality. However, the varying composition, dependant on the different sources of particulate matter, and its effect on processes of inflammation and oxidative stress in the airways has not been completely elucidated. The use of airway biomarkers, fractional exhaled nitric oxide (FENO) and exhaled breath condensate (EBC), can provide valuable insight into processes of inflammation and oxidative stress in the airways. In these studies we sought to characterize the associations between airborne pollutant exposures and their sources and airway biomarkers.
Methods:The study population of interest for Chapters III-V is a subset of children currently enrolled in a birth cohort under the Columbia Children's Center for Environmental Health. Chapter III refers to the validation in this population of a method for partitioning FENO contributions from the proximal and distal airways. Chapters IV and V refer to the implementation of this method in the study of ambient metals and residential proximity to relevant sources of particulate matter (PM) and black carbon (BC). Briefly, the children of African-American and Dominican mothers living in low-income NYC neighborhoods had FENO samples collected offline at constant flow rates of 50, 83 and 100 mL/sec at ages 9 and/or 11. Surrogate measures for bronchial flux NO (JNO) and alveolar (Calv) NO concentrations were estimated using a previously validated mathematical model. Wheeze in the last 12 months was assessed by the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Seroatopy was determined by specific IgE at age 9. For Chapter IV, in order to examine the associations between metal fractions of particulate matter and airway inflammation, ambient measures of Ni, V, Zn and Fe were obtained from a local central monitoring site and averaged over nine days based on three 24 hour measures every third day. Seroatopy was determined by specific IgE at age 7. For Chapter V, residential distance to a major road, truck route and bus stop density, area covered by major roads, stationary point sources (SPS), toxic release inventory sites (TRIS) and commercial buildings, and number of buildings burning residual oil within 250-meters of each child's home were determined. These variables were selected a priori as potential important sources or airborne PM and BC. For Chapter VI, the study population was comprised of seven- and eight-year-old children enrolled in an asthma case-control study in New York City. Seven day averages of domestic levels of particulate matter <2.5 microns (PM2.5), BC and environmental tobacco smoke (ETS) were measured. Urea and 8-isoprostane were measured by liquid chromatography tandem mass spectrometry (LC/MS/MS) in EBC collected during home visits. All data were analyzed with SPSS.
Results: In our first study, children with seroatopy had significantly higher median JNO p<0.001) when compared to non-seroatopic children; however, median Calv was not significantly different between these two groups (p=0.644). Children with wheeze in the past year had significantly higher median Calv (p<0.001), but not JNO (295 vs. 165 pL/s, p=0.241) when compared with children without wheeze. In our second study, ambient V and Fe concentrations were associated positively with FENO50 (p=0.018, p=0.027). Ambient Fe was associated positively with JNO (p=0.017). Ambient Ni and V concentrations were associated positively with Calv (p=0.004, p=0.018 respectively). A stronger association of Ni concentrations with Calv was observed among the children with seroatopy. In our third study, there were no significant associations between any of the air pollution indicator variables and FENO parameters in adjusted models.
In our final study, PM2.5and BC, but not ETS, were significantly associated with increases in 8-isoprostane (p<0.05 for both) after adjustment for covariates. In a co-pollutant model including PM2.5, BC and ETS, only BC remained a statistically significant predictor of 8-isoprostane.
Discussion: Recent exposure to airborne pollutants was associated with increased levels of biomarkers of airway inflammation and oxidative stress measured in exhaled breath. The metal and BC fractions of PM might be more relevant to the understanding adverse respiratory outcomes related to air pollution exposure
Four temptations against urban renewel: an approach to fur current urban processes
Comunicación presentada en 25 European Network housing Research International Conference. Tarragona 19 al 22 junio 2013The new paradigm of urban social and economic rehabilitation is replacing the
current sprawl growth model. But four temptations must be considered:
1) The high-density. This process is possible in sprawl model, but its quantification does not
seem to be clear, because after a certain threshold of occupancy per unit area, the city seems to
collapse and social and environmental benefits disappear, appearing reversal processes city to
country in search of a minimum quality of life standards. There is not a model for appropriate
density. It depends on the way of life of population, the traditional city model.
2) The replacement. Architectonic and urban rehabilitation must be preferred to replacement,
except for certain cases to be legally taxed. But as the city cannot be densified and orderly,
without the prior replacement of the building, may fit this temptation. Even replacing the
building can be made without considering high building standards
3) The gentrification. There is a wide doctrine and experience about this phenomenon with
serious social consequences. It is very tempting to replace the building, due to improve
requirement of broad levels of quality, entering a game of speculation, so common in our real
estate market.
4) The eco-city. Comprehensive projects are building spaces with low levels of energy
consumption. Fall into this temptation means to continue the extensive city model we have been
developing, creating new cities far from the existing but incorporating saving measures, and
continuing resource consumptio
Lagrangian particle tracking for the assessment of the flushing efficiency of harbor structures: the case of the Port of the Bay of Algeciras, Strait of Gibraltar
The Bay of Algeciras, an inlet of about 9 x 11 km located at the eastern margin of the Strait of Gibraltar, opens to the south, where the Atlantic jet leaves the Strait and starts spreading into the Alboran Sea. In its western side, the Bay hosts one of the main ports in Europe, neuralgic base of the major traffic load from Europe to Africa and from Europa to the rest of the oversea countries. The massive transport of liquid and solid bulk or bunkering activity, daily carried out in the Bay, combined with the harsh weather conditions that often lash the zone, give the ideal scenario for an incipient ecological disaster. This high environmental risk motivates the interest for a deeper understanding of the small scale dynamics of the Bay and the role played by the port structures in case of oil spill or other surface contaminations. A series of Lagrangian particles tracking (LPT) experiments were carried out to investigate the flushing patterns of the Bay and 8 different docks inside the local port, under a representative variety of external conditions, such as tide phase and strength, and winds. A 2D LPT algorithm has been adapted to fully exploit the outputs of a very high resolution (∼30m) three-domain-nested hydrodynamic model, with the aim of resolving the complex circulation within the structures of the harbor. Winds are a clearly dominant factor, with westerlies featuring e-folding times one order of magnitude lower than easterlies. Fortnightly tidal modulation presents a counter-intuitive effect, with spring tides that, despite promoting higher ventilation in a first instance, end up providing higher accumulation of particles inside the docks and higher e-folding times than neap tides. Tide phase affects the current direction at the entrance of the docks during the first few hours of simulation and its effect is progressively masked throughout the experiment. In the 45% of the experiments, a significant quantity of particles flow out to the Alboran Sea (55% in the whole Bay experiment), confirming the importance of the Bay on the exportation of pollutant/properties to the nearby basin.Universidad de Málaga. Campus de Excelencia Internacional del Mar, CEIMAR. Campus de Excelencia Internacional Andalucía Tec
Mediterranean outflow and its link with upstream conditions in Alboran Sea
The Western Alboran Gyre (WAG) at the eastern entrance of the Strait of Gibraltar can influence the Mediterranean outflow
(MOW) by favoring or hampering the flow of Levantine and Western Mediterranean (LIW and WMDW) waters, the main
constituents of the MOW. Observations collected at Camarinal sill in the Strait and AVISO data are used to investigate this issue.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
The influence of tides on the exchange through the Strait of Gibraltar and on properties of the Mediterranean Sea
A. Ishlinsky Institute for Problems in Mechanics, Rusi
Biomimetic flow fields for proton exchange membrane fuel cells: A review of design trends
Bipolar Plate design is one of the most active research fields in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) development. Bipolar Plates are key components for ensuring an appropriate water management within the cell, preventing flooding and enhancing the cell operation at high current densities. This work presents a literature review covering bipolar plate designs based on nature or biological structures such as fractals, leaves or lungs. Biological inspiration comes from the fact that fluid distribution systems found in plants and animals such as leaves, blood vessels, or lungs perform their functions (mostly the same functions that are required for bipolar plates) with a remarkable efficiency, after millions of years of natural evolution. Such biomimetic designs have been explored to date with success, but it is generally acknowledged that biomimetic designs have not yet achieved their full potential. Many biomimetic designs have been derived using computer simulation tools, in particular Computational Fluid Dynamics (CFD) so that the use of CFD is included in the review. A detailed review including performance benchmarking, time line evolution, challenges and proposals, as well as manufacturing issues is discussed.Ministerio de Ciencia, Innovación y Universidades ENE2017-91159-EXPMinisterio de Economía y Competitividad UNSE15-CE296
Conducting a virtual ensemble with a kinect device
This paper presents a gesture-based interaction technique for the implementation of an orchestra conductor and a virtual ensemble, using a 3D camera-based sensor to capture user’s gestures. In particular, a human-computer interface has been developed to recognize conducting gestures using a Microsoft Kinect device. The system allows the conductor to control both the tempo in the piece played as well as the dynamics of each instrument set independently. In order to modify the tempo in the playback, a time-frequency
processing-based algorithmis used. Finally, an experiment was conducted to assess user’s opinion of the system as well as experimentally confirm if the features in the system were effectively improving user experience or not.This work has been funded by the Ministerio de Economia y Competitividad of the Spanish Government under Project No. TIN2010-21089-C03-02 and Project No. IPT-2011-0885-430000 and by the Junta de Andalucia under Project No. P11-TIC-7154. The work has been done at Universidad de Malaga. Campus de Excelencia Internacional Andalucia Tech
- …