259 research outputs found
Vapour - Liquid Equilibrium measurements of CO2 based mixtures: Experimental apparatus and testing procedures
At present, the accurate evaluation of the thermo-physical behaviour of multicomponent fluids represents a crucial element for studying and simulating low CO2 emission energy conversion technologies. In order to extend the range of application of the available thermodynamic models, an intense experimental research activity has been performed in recent years. The main purpose of this paper is to describe the experimental and modelling procedures applied by the authors to measure and to analyse data extracted from the Vapour-Liquid Equilibrium apparatus recently installed at LEAP laboratory. This test rig allows the characterization of mixture phase equilibrium properties on the basis of the static-analytical method, within the pressure and temperature ranges of 0-20 MPa and -60-200°C. Finally, the paper reports the most relevant features and the main guidelines for the instruments calibration procedures. © 2013 The Authors
Evaluating The Potential Energy Savings Of An Urban Green Infrastructure Through Environmental Simulation
Green infrastructure is a very important aspect to be considered in designing and preparing cities to adapt and mitigate climate change impacts on the built environment. Green based solutions have a strong impact on many aspects, such as controlling storm-water, reducing urban heat island effect, stabilizing soils, facing earthquakes, etcetera. In this paper an environmental analysis is performed by simulation with TRNSYS Studio tool. The cooling potential that can be obtained by trees in residential compounds is assessed, considering shadowing effect, changes in air movement, sky view factor reduction and other simulation-parameter changes. Results show that a reduction of 30 to 50% in cooling demand can be obtained by using a raw of trees on South, East and especially West façades. Two types of trees are tested, showing different cooling performances depending on the height and form of the trees
Distribution of Pseudomonas species in a dairy plant affected by occasional blue discoloration
During 2010 many cases of discoloration in mozzarella, popularly termed as blue mozzarella, have been reported to the attention of public opinion. Causes of the alteration were bacteria belonging to the genus Pseudomonas. The strong media impact of such cases has created confusion, not only among consumers, but also among experts. In order to help improving the knowledge on microbial ecology of this microorganism a study has been set up with the collaboration of a medium-sized dairy plant producing fresh mozzarella cheese, with occasional blue discoloration, conducting surveys and sampling in the pre-operational, operational and post-operational process phase, milk before and after pasteurization, water (n=12), environmental surfaces (n=22) and the air (n=27). A shelf life test was conducted on finished products stored at different temperatures (4-8°C). Among the isolates obtained from the microbiological analysis of the samples, 60 were subjected to biomolecular tests in order to confirm the belonging to Pseudomonas genus and to get an identification at species level by the amplification and sequencing of the gyrB gene. The results of microbiological tests demonstrated the presence of microorganisms belonging to the genus Pseudomonas along the entire production lane; molecular tests showed 7 different species among the 40 isolates identified. One particular species (Pseudomonas koreensis) was isolated from blue discolored mozzarella cheese and was indicated as the most relevant for the production plant, both for the distribution along the processing chain and for the consequences on the finished product
Human cytomegalovirus-specific CD4+ and CD8+ T-cell reconstitution in adult allogeneic hematopoietic stem cell transplant recipients and immune control of viral infection
Background Human cytomegalovirus infection is the most frequent viral complication in patients undergoing hematopoietic stem cell transplantation. We investigated the development of human cytomegalovirus-specific T cells in adult recipients of hematopoietic stem cell transplants. Design and Methods From May 2003 through October 2006 a total of 45 patients were monitored for human cytomegalovirus-specific T-cell reconstitution. Human cytomegalovirus-infected autologous dendritic cells were used as a stimulus to detect interferon-Îł-producing human cytomegalovirus-specific CD8+ and CD4+ T cells during the first year after transplantation. Interleukin-2 production by specific T cells was also determined. ![Figure 1.][1] Figure 1. Probability of HCMV infection development and HCMV-specific CD4+ and CD8+ T-cell immunity reconstitution. A: cumulative incidence curves of HCMV infection according to donor (D) and recipient (R) HCMV-serostatus. B: cumulative incidence curves of HCMV infection and HCMV-specific CD8+ and CD4+ T-cell reconstitution (i.e. corresponding to a specific T-cell number greater than 0.4 cells/ÎĽL blood). C: cumulative incidence curves of HCMV-specific CD8+ T-cell reconstitution according to D/R HCMV-serostatus. D: cumulative incidence curves of HCMV-specific CD4+ T-cell reconstitution according to D/R HCMV-serostatus. Results Human cytomegalovirus infection was detected in the blood of 39/45 patients at a median of 29 days after transplantation. Human cytomegalovirus-specific T-cell reconstitution followed reactivation of latent human cytomegalovirus infection at a median time of about 2 months after transplantation. Only donor human cytomegalovirus-seronegativity and bone marrow as a stem cell source were found to delay specific T-cell reconstitution significantly. Levels of three CD8+ and one CD4+ human cytomegalovirus-specific T-cells/ÎĽL blood had a positive predictive value of around 80% for identifying patients able to control human cytomegalovirus infection spontaneously. Five patients who received high doses of steroids for treatment of graft-versus-host disease developed human cytomegalovirus infection requiring pre-emptive treatment despite high levels of interferon-Îł-producing T cells in response to human cytomegalovirus. Specific interleukin-2 production was not detected in patients with human cytomegalovirus infection requiring treatment, while 90% of patients who spontaneously controlled human cytomegalovirus infection had T cells that produced interleukin-2 and interferon-Îł. Conclusions Pre-transplant human cytomegalovirus infection of the recipient is a major factor driving human cytomegalovirus-specific immune reconstitution. Control of human cytomegalovirus infection likely requires the presence of both interferon-Îł and interleukin-2 producing T cells. Corticosteroid treatment may favor active viral replication even in patients with specific T cells. [1]: pending:ye
Satellite SAR interferometric techniques in support to emergency mapping
This paper investigates the potential of Synthetic Aperture Radar (SAR) interferometry in the field of emergency mapping, assessing its suitability for both rapid mapping, aimed at supporting the immediate response phase after a disastrous event, and risk mapping, addressing risk prevention and mitigation activities. The conventional Differential Interferometric SAR technique (DInSAR) and the two currently available multi-temporal interferometric approaches, i.e. Permanent Scatterers (PS) and Small BAseline Subset (SBAS), have been evaluated focusing on the main emergency mapping requirements, namely crisis information product types, availability of optimal input data, requirements in terms of auxiliary data, processing time and expected accuracy. The aforementioned investigations have been carried out exploiting the European Space Agency (ESA) C-band Sentinel-1 mission, characterized by a free, full and open data policy. Therefore, this paper will not assess different SAR sensors and their different technical specifications, e.g. wavelength and space resolution. Representative results are presented and discussed with the aim to describe the possible interferometric product types in specific emergency mapping scenarios
A Survey on One Health Approach in Colombia and Some Latin American Countries: From a Fragmented Health Organization to an Integrated Health Response to Global Challenges
The “One Health” (OH) approach has been recognized by world health authorities such as FAO/OIE/WHO, advocating for effective, multi-sectoral, and transdisciplinary collaboration. However, there is a lack of published evidence of the awareness of the OH concept in Colombia and other countries in the Latin American Region. In order to explore existing collaboration amongst the animal health, human-public health, environmental health sectors, and to describe the perception, knowledge, and barriers on OH in Colombia and other countries of Latin America, an online questionnaire-based survey was distributed among key professionals representing the three OH pillars (August 2018–August 2020). Overall, 76 key respondents from 13 countries (Colombia, México, Chile, Brazil, Argentina, Bolivia, Costa Rica, Ecuador, Perú, Guatemala, Nicaragua Uruguay, and Venezuela) completed the questionnaire. Respondents worked in institutions of animal (59%), public (20%), human (7%), and environmental health (7%); they mainly belonged to higher academic institutions (59%), followed by ministries (11%), and research organizations (9%). Most participants (92%) were familiar with the OH term and 68% were aware of the formal cooperation among sectors in their countries, mostly on zoonoses; in 46% of the cases, such connections were established in the last 5 years. The main reported limiting factors to intersectorality were the lack of commitment of policy-makers, resources, and budget for OH (38%) and the “siloed approach” of sectors and disciplines (34%). Respondents ranked a median score of 3.0 (1–5 scoring) in how good OH activities are implemented in their countries, and a median score of 2.0 in the citizen awareness on OH as regards their countries. The most important OH issues were identified in vector-borne diseases, rabies, wrong and/or improper use of antimicrobials, emerging viral diseases, food-borne diseases, neglected parasitic diseases, deforestation, and ecosystem fragmentation. Although there is a high-perceived importance on conjoint cooperation, OH implementation, and operationalization remain weak, and the environmental component is not well-integrated. We consider that integration and implementation of the OH Approach can support countries to improve their health policies and health governance as well as to advocate the social, economic, and environmental sustainability of the Region
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